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Journal articles on the topic 'Porogen selection'
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Mansour, Fotouh R., Sidra Waheed, Brett Paull, and Fernando Maya. "Porogens and porogen selection in the preparation of porous polymer monoliths." Journal of Separation Science 43, no. 1 (October 30, 2019): 56–69. http://dx.doi.org/10.1002/jssc.201900876.
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Yang, Hua, Huien Zhang, Xiao Yan Zhu, Shi Da Chen, Lijun Liu, and Daodong Pan. "Determination of Tributyltin in Seafood Based on Magnetic Molecularly Imprinted Polymers Coupled with High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry." Journal of Food Quality 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/7405475.
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In this study, Fe3O4 was adopted as a carrier for surface molecular imprinting with two-stage polymerization. First, the functional monomer (methacrylic acid, MAA) was modified on the surface of Fe3O4, which was then polymerized with the template molecule (tributyltin, TBT), cross linking agent (ethylene glycol dimethacrylate, EGDMA), and porogen (acetonitrile), hereby successfully preparing Fe3O4@MIPs prone to specifically identify TBT. The physical properties of Fe3O4@MIPs were then characterized, and adsorption and selection capacities were also assessed. Compared with conventional imprinting polymers, this magnetic molecular imprinting polymer (MIP) displayed significantly increased and more specific adsorption. Meanwhile, its pretreatment was simpler and faster due to magnetic separation characteristics. Using magnetic MIPs as adsorbents for enrichment and separation, detection limit, recovery rate, and linear range were 1.0 ng g−1, 79.74–95.72%, and 5 ng g−1~1000 ng g−1, respectively, for a number of seafood samples. High-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used to analyze Tegillarca granosa, mussels, large yellow croaker, and other specimens, with recovery rates of 79.74–95.72% and RSD of 1.3%–4.7%. Overall, this method has a shorter total analysis time, lower detection limit, and wider linear range and can be more effectively applied to determine MAA in seawater and seafood.
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Schwarz, Lachlan, Michael C. Bowyer, Clovia I. Holdsworth, and Adam McCluskey. "Synthesis and Evaluation of a Molecularly Imprinted Polymer Selective to 2,4,6-Trichloroanisole." Australian Journal of Chemistry 59, no. 2 (2006): 129. http://dx.doi.org/10.1071/ch05318.
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In the wine industry 2,4,6-trichloroanisole (TCA) has been identified as the primary contaminant responsible for ‘cork taint’. A molecularly imprinted polymer (MIP) selective for TCA was prepared in three porogens (hexane, acetonitrile, and dichloromethane) of varying polarities using non-covalent molecular imprinting techniques. Target rebinding to the MIP was found to be most effective in its porogenic solvent and highest in dichloromethane (imprinting factor = 3.65). Competitive binding assays performed against a range of close structural analogues demonstrated a preference for the target molecule.
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Lubguban, J. A., S. Gangopadhyay, B. Lahlouh, T. Rajagopalan, N. Biswas, J. Sun, D. H. Huang, et al. "Supercritical CO2extraction of porogen phase: An alternative route to nanoporous dielectrics." Journal of Materials Research 19, no. 11 (November 1, 2004): 3224–33. http://dx.doi.org/10.1557/jmr.2004.0413.
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We present a supercritical CO2(SCCO2) process for the preparation of nanoporous organosilicate thin films for ultralow dielectric constant materials. The porous structure was generated by SCCO2extraction of a sacrificial poly(propylene glycol) (PPG) from a nanohybrid film, where the nanoscopic domains of PPG porogen are entrapped within the crosslinked poly(methylsilsesquioxane) (PMSSQ) matrix. As a comparison, porous structures generated by both the usual thermal decomposition (at approximately 450 °C) and by a SCCO2process for 25 and 55 wt% porogen loadings were evaluated. It is found that the SCCO2process is effective in removing the porogen phase at relatively low temperatures (<200 °C) through diffusion of the supercritical fluid into the phase-separated nanohybrids and selective extraction of the porogen phase. Pore morphologies generated from the two methods are compared from representative three-dimensional (3D) images built from small-angle x-ray scattering (SAXS) data.
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Bennett, Jeffrey A., Zachary S. Campbell, and Milad Abolhasani. "Continuous synthesis of elastomeric macroporous microbeads." Reaction Chemistry & Engineering 4, no. 2 (2019): 254–60. http://dx.doi.org/10.1039/c8re00189h.
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Chuang, Yun-Ju, Mei-Jung Chen, and Pei-Ru Chen. "Fabrication and Permeability Characteristics of Microdialysis Probe Using Chitosan Nanoporous Membrane." Journal of Nanomaterials 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/968098.
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In this article, a nanoporous chitosan polymer membrane was successfully produced and applied as microdialysis membrane forin vitrosampling of biomolecules. With the use of nanoparticle leaching technique, porogenic gelatin nanoparticles formed nanopores in the chitosan-based membrane to create a secure implantable nanoporous membrane for biomolecule sampling. The gelatin nanoparticles size was in the range of 45 to 70 nm, and the pore size of the chitosan membrane was around 40 to 100 nm. The porosity of membrane was found to be dependent on the mixing ratio of chitosan solution and gelatin nanoparticles solution. The results of diffusion study showed that we can alter the mixing ratio of porogen to achieve size-selective molecular diffusion, which means that the porosity and cut-off size of porous membrane can be controlled. The recoveries of the probe fabricated from the chitosan-based membrane were examined for four different model compounds of different molecular weights: 2-NBDG, substance P, TNF-α, and FITC-BSA. The microdialysis probes showed linear responses and substantial recovery to various concentrations of biomolecules. These results indicated that the microdialysis probe constructed by chitosan nanoporous membrane could sample and monitor the biomoleculesin vitroand has the potential for the applicationin vivo.
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Nisticò, Roberto. "Block copolymers for designing nanostructured porous coatings." Beilstein Journal of Nanotechnology 9 (August 29, 2018): 2332–44. http://dx.doi.org/10.3762/bjnano.9.218.
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Highly ordered porous coatings find applications in many fields, such as nanotechnology, microfluidics and nanofluidics, membrane separation, and sensing. In recent years, there has been great interest regarding the synthesis of isoporous and well-ordered (in)organic coatings for the production of highly selective functional membranes. Among the different strategies that have been proposed to date for preparing these porous thin coatings, one simple route involves the use of self-assembled amphiphilic block copolymers either as the porogen (acting as sacrificial templating agents for the production of inorganic architectures) or as a source of the porogen (by self-assembly for the production of polymeric substrates). Therefore, an extended discussion around the exploitation of block copolymers is proposed here in this review, using polystyrene-block-polyethylene oxide (PS-b-PEO) as the model substrate, and critical points are highlighted.
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Lomenova, Anna, and Katarína Hroboňová. "Preparation and application of molecularly imprinted polymers for chiral HPLC separation of biologically active substances." Nova Biotechnologica et chimica 19, no. 1 (June 30, 2020): 1–18. http://dx.doi.org/10.36547/nbc.v19i1.573.
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Chiral separations are one of the important analytical tasks, since there are increasing demands for production of enantiomerically pure compounds. The separation and determination of enantiomers find applications in pharmaceutical and food analysis, and it is necessary to pay attention to the development and improvement of chiral analytical methods. High performance liquid chromatography (HPLC) with chiral stationary phase (CSP) based on molecularly imprinted polymers (MIPs) is perspective way. One of the main advantage of these stationary phases is the possibility of predetermining the elution order of enantiomers. The presented work is focused on the methods of preparation and the applications of selective sorption materials (MIPs) in the field of HPLC separation of biologically active substances, amino acids. This review contains comprehensive informations about MIP-amino acid synthesis: compositions of polymerization mixture (monomer, template, cross-linker, porogen), type of polymerization and polymerization conditions, what can affect final efficiency of enantioseparation. The most used porogen was toluene, crosslinker ethylene glycol dimethacrylate (EDMA) and initiator azoisobutyronitrile (AIBN). MIP CSP prepared for derivatized amino acids show better results (higher resolution) than MIP prepared for underivatized amino acids. MIP are very promising material to be used as stationary phase in HPLC, although further developments and new approaches are necessary to fully exploit their potential.
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Takada, Norio, Sogo Nishio, Masahiko Yamada, Yutaka Sawamura, Akihiko Sato, Toshio Hirabayashi, and Toshihiro Saito. "Inheritance of the Easy-peeling Pellicle Trait of Japanese Chestnut Cultivar Porotan." HortScience 47, no. 7 (July 2012): 845–47. http://dx.doi.org/10.21273/hortsci.47.7.845.
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‘Porotan’ is a Japanese chestnut cultivar (Castanea crenata Sieb. et Zucc.) that was selected from offspring of the cross 550-40 × ‘Tanzawa’ and released in 2006. Its nut is distinguished by a pellicle that is easy to peel after roasting; previously, all Japanese chestnut cultivars were thought to have a pellicle that was difficult to peel. Both 550-40 and ‘Tanzawa’ are Japanese chestnuts, and 550-40 is a selection descended from ‘Tanzawa’. Both 550-40 and ‘Tanzawa’ have a pellicle that is difficult to peel. Among 59 offspring of a cross of 550-40 × ‘Tanzawa’, 12 had an easy-peeling pellicle and 47 had a difficult-peeling pellicle; this ratio is not significantly different from the 1:3 expected ratio for monogenic inheritance based on a chi-square test at P = 0.05. A half-diallel cross without selfings was made among ‘Porotan’, ‘Tanzawa’, and ‘Tsukuba’. All the offspring from ‘Tanzawa’ × ‘Tsukuba’ and from ‘Tsukuba’ × ‘Porotan’ had a difficult-peeling pellicle; in contrast, 39 offspring from ‘Tanzawa’ × ‘Porotan’ segregated in a ratio of 19 difficult-peeling pellicle to 20 easy-peeling pellicle, which is not significantly different from the expected 1:1 ratio for monogenic segregation based on a chi-square test at P = 0.05. These results suggest that the easy-peeling pellicle trait of ‘Porotan’ is controlled by a major recessive gene at a single locus. We designated the pellicle peelability locus as P/p. According to this model, the ‘Tsukuba’ genotype is homozygous-dominant (PP), the ‘Tanzawa’ genotype is heterozygous (Pp), and the ‘Porotan’ genotype is homozygous-recessive (pp).
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Hroboňová, Katarína, Jozef Lehotay, and Jozef Čižmárik. "Examination of the Chemical Composition of Propolis IX. Solid Phase Extraction of Coumarins from Propolis by Using Molecularly Imprinted Polymer." Nova Biotechnologica et Chimica 12, no. 1 (June 1, 2013): 1–11. http://dx.doi.org/10.2478/nbec-2013-0001.
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Abstract The group selective molecularly imprinted polymers (MIPs) for coumarins, including umbelliferone, herniarin, 4-methylumbelliferone, scoparone were developed. Using umbelliferone as the template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as linking agent, chloroform as porogen and bulk polymerization as synthetic method, the MIPs were synthesized and characterized with rebinding experiments. The characteristics of MIPs were evaluated by chromatographic method and frontal analysis, and demonstrating good selectivity and high binding capacity (269 μg of umbelliferone per 100 mg of polymer). The group selective MIP was used as sorbent for the SPE pretreatment of coumarins from propolis extracts prior to HPLC analysis. Analysis of the samples showed good recoveries (>70 %). The limits of quantitation (LOQs) for studied compounds were 0.3-10 ng.mL-1 (determined for fluorescence detection).
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Booker, Katherine, Clovia I. Holdsworth, Cara M. Doherty, Anita J. Hill, Michael C. Bowyer, and Adam McCluskey. "Ionic liquids as porogens for molecularly imprinted polymers: propranolol, a model study." Org. Biomol. Chem. 12, no. 37 (2014): 7201–10. http://dx.doi.org/10.1039/c4ob00547c.
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The selectivity and rebinding capacity of molecularly imprinted polymers selective for propranolol (1) using the room temperature ionic liquids [BMIM][BF4], [BMIM][PF6], [HMIM][PF6] and [OMIM][PF6] and CHCl3 were examined.
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Koenig, Meike, and Joerg Lahann. "Nanotopographical control of surfaces using chemical vapor deposition processes." Beilstein Journal of Nanotechnology 8 (June 12, 2017): 1250–56. http://dx.doi.org/10.3762/bjnano.8.126.
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In recent years much work has been conducted in order to create patterned and structured polymer coatings using vapor deposition techniques – not only via post-deposition treatment, but also directly during the deposition process. Two-dimensional and three-dimensional structures can be achieved via various vapor deposition strategies, for instance, using masks, exploiting surface properties that lead to spatially selective deposition, via the use of additional porogens or by employing oblique angle polymerization deposition. Here, we provide a concise review of these studies.
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Suherman, Meilia, Ike Susanti, Driyanti Rahayu, Rimadani Pratiwi, and Aliya Nur Hasanah. "Performance Evaluation of Molecularly Imprinted Polymer using Propanol as Porogen for Atenolol Recognition in Human Serum." Indonesian Journal of Pharmaceutical Science and Technology 6, no. 1 (October 29, 2018): 27. http://dx.doi.org/10.24198/ijpst.v6i1.18671.
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Atenolol is a cardiovascular drug that has a narrow therapeutic index with long-term use and it’s often used as doping. Atenolol has a small concentration in human boby and it’s in biological matrix (serum) so in the testing need a selective extraction so the analyte can be pra-concentration and removed from matrix. Two molecularly imprinted polymers (MIPs) on propanol as porogen have been made with two different methods i.e. bulk polymerization and precipitation polymerization. The polymer was made using atenolol as a template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinker. Prformance evaluations showed that polymers from bulk polymerization provide better performance than polymers from precipitation polymerization when tested against standard solution. However, this sorbent has low recovery percentage after applied into serum sample and could not be used as alternative for atenolol extraction in human serum.Key words: Molecularly imprinted polymer, Atenolol, Solid Phase Extraction, Preparation method, propanol.
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Lu, Fu Guang, Yu Lei Xi, Zhen Lv, Lu Lu Fan, Hua Min Qiu, and Chuan Nan Luo. "Molecularly Imprinted Polymer for Preparation and Adsorption of Phenylalanine." Advanced Materials Research 306-307 (August 2011): 638–41. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.638.
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Molecular imprinting technology was employed to produce one kind of Phenylalanine ( Phe) molecularly imprinted polymers (MIP)by precipitation polymerization using Phe, anhydrous alcohol, acrylamide, ethylene glycol dimethacrylate, and azobisisobutyronitrile as template, porogen, functional monomer, cross-linker and initiator respectively. In this study, the polymerization conditions were optimized. The template on particle size and morphology of polymers were investigated in detail by scanning electron microscopy (SEM) and adsorption isotherm determination. The binding properties of Phe on imprinted polymers were evaluated in water by equilibrium rebinding experiments, and the maximum number of adsorption was 0.60 mmol/g. It is indicated that the existence of binding sites in imprinted polymers was proved and the binding sites showed good specific and selective capability to the template molecule Phe. So the polymers would be used to separate Phe from medicine and food.
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Yuan, Xin Hua, Wen Hua Guo, Yan Lei, Yong Qiang Liu, Ji Ye Wu, Wei Qun Qiu, Jie Hu, and Shun Sheng Cao. "Adsorption of Benzene and Aniline Using a Novel Hypercrosslinked Polymeric Adsorbent Modified by Phenolic Hydroxyl Group." Key Engineering Materials 575-576 (September 2013): 130–34. http://dx.doi.org/10.4028/www.scientific.net/kem.575-576.130.
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Using gelatin as dispersant, liquid paraffin as porogen, novel hypercrosslinked polymeric adsorbents of LM-5 and LM-6 were prepared by post-crosslinking reaction with phenol and 2-naphthol, respectively. Bromoethane was used as crosslinking reagent to substitute poisonous organic compound of chloromethyl methylether. 2-Naphthol was used in the post-crosslinking reaction to enhance phenolic hydroxyl group content. The experiments of selective adsorbing aniline on resins in mixture solution, which consisting of benzene and aniline, show that the adsorption of aniline and benzene on LM-6 in aqueous solution are mainly pushed by physical interaction. The adsorption of aniline is also partly pushed by chemical interaction, and the adsorptive enthalpy illuminates that there exists hydrogen-bonding. Owning to the hydrogen-bond, the adsorption capacity of aniline on LM-6 is markedly higher than that of benzene.
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Firouzzare, Mahmoud. "Preparation of a Novel Selective Adsorbent for Detection and Measurement of Mercury (II) Ions." Advanced Materials Research 718-720 (July 2013): 645–49. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.645.
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In this work, a polymeric adsorbent was synthesized by the imprinting technique for the measurement of Hg (II) ion from aqueous environmental samples. For this purpose, a novel aminothiol monomer has been initially synthesized then it has been used for complexing the mercury. The synthesized complex monomer copolymerized with methacrylic acid and ethylene glycol dimethacrylate and AIBN as the functional monomer, cross-linker and initiator respectively in the presence of a binary porogen of DMSO and toluene. The imprinted polymer was made after removing the mercury (II) ion by an acidic solution of thiourea. The results of batch procedures showed that the Hg (II)-imprinted polymer has adsorption capacity of 28 mg g-1and is high selective for adsorption of Hg (II) ion in competing with the other ions such as CH3Hg (I), Zn (II) and Cd (II) and also in comparing with non-imprinted polymers.
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Schwarz, Lachlan, Clovia I. Holdsworth, Adam McCluskey, and Michael C. Bowyer. "Synthesis and Evaluation of a Molecularly Imprinted Polymer Selective to 2,4,6-Trichlorophenol." Australian Journal of Chemistry 57, no. 8 (2004): 759. http://dx.doi.org/10.1071/ch04004.
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Molecularly imprinted polymers (MIPs) selective for the phenolic contaminant 2,4,6-trichlorophenol (2,4,6-TCP) were prepared and evaluated in three porogens of differing character (hexane, acetonitrile, dichloromethane). Rebinding of 2,4,6-TCP was found to be most effective in dichloromethane (imprinting factor: 13.2). Competitive binding studies performed against a range of close structural analogues showed a high preference for the target molecule, although partial recognition towards 2,4-dichlorophenol was also observed. Specificity was found to be dependent upon the presence of ring chlorine on the target, which suggested that these atoms participate in secondary binding interactions that are essential for successful recognition in the polymer cavity.
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Lahsini, Rym, Mohamed R. Louhaichi, Nafaa Adhoum, and Lotfi Monser. "Preparation and application of a molecularly imprinted polymer for determination of glibenclamide residues." Acta Pharmaceutica 63, no. 2 (June 1, 2013): 265–75. http://dx.doi.org/10.2478/acph-2013-0017.
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The performance of a molecularly imprinted polymer (MIP) as selective packing material for solid-phase extraction (SPE) of residual glibenclamide in an industrial process was investigated. MIP was prepared using 4-vinylpyridine as monomer, ethylenedimethacrylate as cross linker, 2,2’-azobis-2-methylpropionitrile as initiator and dimethyl formamide as porogen. Use of acetonitrile as a rebinding solvent allows good recognition of the glibenclamide template. It was found that this polymer can be used for determination of trace levels of glibenclamide with a recovery percentage that could reach 87.1 %. Furthermore, the synthesized MIP showed higher selectivity towards glibenclamide than other compounds such as glimepiride and metformine. The synthesized MIP enabled direct determination of the target contaminant after an enrichment step that allowed quantification of glibenclamide at a concentration as low as 0.016 mg L-1. Combination of high performance liquid chromatography with MIP-SPE could be successfully used for quality control of pharmaceuticals during the cleaning process in the production of dry drug forms.
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Joke Chow, Alvin Leong, and Showkat Ahmad Bhawani. "Synthesis and Characterization of Molecular Imprinting Polymer Microspheres of Cinnamic Acid: Extraction of Cinnamic Acid from Spiked Blood Plasma." International Journal of Polymer Science 2016 (2016): 1–5. http://dx.doi.org/10.1155/2016/2418915.
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The molecular imprinting technique is used to create the molecularly imprinted polymers (MIPs) with higher binding capacity towards the template. In this research precipitation polymerization method with noncovalent approach was used to synthesize imprinted polymer microspheres. The polymerization reaction was conducted in a flask containing acetonitrile as a porogen, cinnamic acid as a template (T), acrylic acid (AA) as a monomer, divinylbenzene (DVB) as a cross-linker, and azobisisobutyronitrile as an initiator. The polymer particles were characterized by using SEM and FTIR. The rebinding efficiency was conducted by batch binding assay and the results were monitored by using HPLC. The batch binding results suggested MIP1 (T : AA : DVB, 1 : 6 : 20 molar ratio) is most suitable composition for the rebinding of cinnamic acid. The highly selective polymer (MIP1) was used for the extraction of cinnamic acid from human plasma. The extraction efficiency of imprinted polymer of cinnamic acid from spiked plasma was above 75%.
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Hasanah, Aliya Nur, Firdha Senja Maelaningsih, Fadli Apriliandi, and Akhmad Sabarudin. "Synthesis and Characterisation of a Monolithic Imprinted Column Using a Methacrylic Acid Monomer with Porogen Propanol for Atenolol Analysis." Journal of Analytical Methods in Chemistry 2020 (February 28, 2020): 1–15. http://dx.doi.org/10.1155/2020/3027618.
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A monolithic imprinted atenolol column was constructed by in situ polymerisation using a methacrylic acid monomer and a 1 : 1 (v/v) porogen of propanol: toluene with two template: monomer: crosslinker combinations, namely, MIP 1 (1 : 4 : 20) and MIP 2 (1 : 5 : 20). Physical characterisation of the monolithic columns consisted of permeability testing, Fourier transform infrared (FTIR) testing, surface area analysis (SAA), and scanning electron microscopy (SEM). The permeability value of four monolithic columns was in the good category: MIP 1 (24.01 mD), NIP 1 (56.43 mD), MIP 2 (23.03 mD), and NIP 2 (14.47 mD). The polymerisation process of these four monolithic imprinted columns was carried out perfectly, as shown by the absence of vinyl groups (1000 cm−1 and 900 cm−1) during FTIR testing. Based on SAA testing, the pores of the four polymers were classified as mesopores. The best monolithic column was MIP 1, as seen from the intercolumn and intracolumn reproducibility values and a % RSD <2.0%. The MIP 1 column was selective towards atenolol, as seen from the selectivity factor, imprinting factor (IF), and resolution (Rs) values. The IF values of MIP 1 were atenolol (204.62), metoprolol (3.36), and propranolol (1.27). The Rs value between atenolol and the analogue compounds was 7.23. The MIP 1 column can be used for the analysis of atenolol in blood serum samples with an average percentage recovery rate of 94.88 ± 4.43%.
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Ravichandran, Dharneedar, Weiheng Xu, Rahul Franklin, Namrata Kanth, Sayli Jambhulkar, Sumedh Shukla, and Kenan Song. "Fabricating Fibers of a Porous-Polystyrene Shell and Particle-Loaded Core." Molecules 24, no. 22 (November 15, 2019): 4142. http://dx.doi.org/10.3390/molecules24224142.
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Polystyrene (PS) polymers have broad applications in protective packaging for food shipping, containers, lids, bottles, trays, tumblers, disposable cutlery and the making of models. Currently, most PS products, such as foams, are not accepted for recycling due to a low density in the porous structure. This poses a challenge for logistics as well as creating a lack of incentive to invest in high-value products. This study, however, demonstrated the use of a dry-jet wet-spinning technique to manufacture continuous PS fibers enabled by an in-house designed and developed spinning apparatus. The manufactured fibers showed porosity in the shell and the capability to load particles in their core, a structure with high potential use in environmentally relevant applications such as water treatment or CO2 collections. A two-phase liquid-state microstructure was first achieved via a co-axial spinneret. Following coagulation procedures and heat treatment, phase-separation-based selective dissolution successfully generated the porous-shell/particle-core fibers. The pore size and density were controlled by the porogen (i.e., PEG) concentrations and examined using scanning electron microscopy (SEM). Fiber formation dynamics were studied via rheology tests and gelation measurements. The shell components were characterized by tensile tests, thermogravimetric analysis, and differential scanning calorimetry for mechanical durability and thermal stability analyses.
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Bodoki, Andreea, Bogdan-Cezar Iacob, Laura Gliga, Simona Oprean, David Spivak, Nicholas Gariano, and Ede Bodoki. "Improved Enantioselectivity for Atenolol Employing Pivot Based Molecular Imprinting." Molecules 23, no. 8 (July 27, 2018): 1875. http://dx.doi.org/10.3390/molecules23081875.
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In the last few decades, molecular imprinting technology went through a spectacular evolution becoming a well-established tool for the synthesis of highly selective biomimetic molecular recognition platforms. Nevertheless, there is still room for advancement in the molecular imprinting of highly polar chiral compounds. The aim of the present work was to investigate the favorable kosmotropic effect of a ternary complex involving a polar chiral template (eutomer of atenolol) and a functional monomer, bridged by a central metal ion through well-defined, spatially directional coordinate bonds. The efficiency of the chiral molecular recognition was systematically assessed on polymers obtained both by non-covalent and metal-mediated molecular imprinting. The influence on the chromatographic retention and enantioselectivity of different experimental variables (functional monomers, cross-linkers, chaotropic agents, metal ions, porogenic systems, etc.) were studied on both slurry packed and monolithic HPLC columns. Deliberate changes in the imprinting and rebinding (chromatographic) processes, along with additional thermodynamic studies shed light on the particularities of the molecular recognition mechanism. The best performing polymer in terms of enantioselectivity (α = 1.60) was achieved using 4-vinyl pyridine as functional monomer and secondary ligand for the Co(II)-mediated imprinting of S-atenolol in the presence of EDMA as cross-linker in a porogenic mixture of [BMIM][BF4]:DMF:DMSO = 10:1:5, v/v/v.
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Ferdinand, Michelle, Rimadani Pratiwi, and Aliya Nur Hasanah. "Characterization of Imprinted Polymer of Diazepam With Methacrylic Acid and Hydroxyethyl Methacrylate Monomer in Chloroform for Selective Adsorption of Diazepam." Indonesian Journal of Pharmaceutical Science and Technology 7, no. 2 (May 11, 2020): 46. http://dx.doi.org/10.24198/ijpst.v7i2.26230.
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Diazepam is a benzodiazepine class usage is regulated nationally or globally. These drugs can be used to regulate sleep patterns or sedative-hypnotic drugs because it has a calming effect. Monitoring the abuse of diazepam requires a sensitive analysis methods that required the preparation of selective methods. One of the methods that are currently developing is Moleculary Imprinted Polymer-Solid Phase Extraction (MI-SPE). In this research, step being performed include determination of the association constant, synthesis sorbent of Imprinted Polymer (IP) diazepam by bulkpolymerization method with diazepam as a template, chloroform as porogen, two kind of monomer methacrylic acid (MAA) and hydroxyethyl methacrylate (HEMA) as functional monomer. Templates extracted from polymer followed by evaluation of adsorption ability test, a test of capacity and selectivity of the polymer, and also the characterization of the IP using Fourier Transform Infra-Red (FTIR),and Scanning Electron Microscope (SEM). The results showed that IP diazepam with MAA monomer has 7.95 x 10-5 mg/g of capacity, it is better than capacity of IP diazepam monomer HEMA with 7.47x 10-6 mg/g. Selectivity of IP diazepam MAA monomer has an IF value which is 2.13, which is better than IP HEMA with 1.21. In addition, IP diazepam MAA monomer more heterogenous than its Non Imprinted Polymer (NIP).Keywords: Chloroform, Diazepam, HEMA, Methacrylic acid, MI-SPE.
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Figueiredo, Leandro, Lúcia Santos, and Arminda Alves. "Molecularly Imprinted Dispersive-Based Extraction Method for Melamine in Milk (MIDE HPLC DAD)." JOURNAL OF ADVANCES IN CHEMISTRY 10, no. 6 (July 3, 2014): 2775–85. http://dx.doi.org/10.24297/jac.v10i6.882.
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An easy and selective molecularly imprinted dispersive extraction method (MIDE) coupled with HPLC-DAD was developed for melamine´s analysis in commercial milk samples. The molecularly imprinted polymer (MIP) was synthetized by suspension polymerisation with melamine as template, while methacrylic acid, ethylene glycol dimethacrylate and chloroform were used as monomer, cross-linker and porogenic solvent, respectively. The analytical methodology was validated presenting a limit of detection of 0.6 mg/kg. The recovery percentage in spiked milk samples ranged from 92.9% to 102.0% with an intermediate precision of 5.0%. The analysis of real samples with MIDE revealed melamine´s presence in 20% of the cases with a maximum concentration of 9.3 ± 0.3 mg/kg, which exceeds the maximum recommended level of 2.5 mg/kg.
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Li, Muxin, Rubina Rahaman Khadim, Mitsuru Nagayama, Marie Shinohara, Kousuke Inamura, Mathieu Danoy, Masaki Nishikawa, Katsuko Furukawa, Yasuyuki Sakai, and Toshiki Niino. "Fabrication of a Porous Three-Dimensional Scaffold with Interconnected Flow Channels: Co-Cultured Liver Cells and In Vitro Hemocompatibility Assessment." Applied Sciences 11, no. 6 (March 10, 2021): 2473. http://dx.doi.org/10.3390/app11062473.
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The development of large-scale human liver scaffolds equipped with interconnected flow channels in three-dimensional space offers a promising strategy for the advancement of liver tissue engineering. Tissue-engineered scaffold must be blood-compatible to address the demand for clinical transplantable liver tissue. Here, we demonstrate the construction of 3-D macro scaffold with interconnected flow channels using the selective laser sintering (SLS) fabrication method. The accuracy of the printed flow channels was ensured by the incorporation of polyglycolic acid (PGA) microparticles as porogens over the conventional method of NaCl salt leaching. The fabricated scaffold was populated with Hep G2, followed by endothelization with endothelial cells (ECs) grown under perfusion of culture medium for up to 10 days. The EC covered scaffold was perfused with platelet-rich plasma for the assessment of hemocompatibility to examine its antiplatelet adhesion properties. Both Hep G2-covered scaffolds exhibited a markedly different albumin production, glucose metabolism and lactate production when compared to EC-Hep G2-covered scaffold. Most importantly, EC-Hep G2-covered scaffold retained the antiplatelet adhesion property associated with the perfusion of platelet-rich plasma through the construct. These results show the potential of fabricating a 3-D scaffold with interconnected flow channels, enabling the perfusion of whole blood and circumventing the limitation of blood compatibility for engineering transplantable liver tissue.
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Sirumapea, Lasmaryna, Muhammad Ali Zulfikar, M. Bachri Amran, and Anita Alni. "An Optimization of Functional Monomer, A Preliminary Study of Meropenem Imprinted Polymer as Selective Sorbent." JKPK (Jurnal Kimia dan Pendidikan Kimia) 3, no. 2 (August 31, 2018): 103. http://dx.doi.org/10.20961/jkpk.v3i2.22386.
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<p>Molecularly imprinted polymer is a polymer that synthesized together with targeted molecule (analyte) through polymerization process. When the polymerization has completed, extraction is taken to pull the analyte out of the polymer, and it will give a specific “frame” of targeted molecule which leave cavities and further is used to give specific recognition of the analyte. Functional monomer, template molecule, crosslinker agent, porogenic solvent and initiator are the main components involved in the synthesis of this kind of polymer. The right functional monomer is needed to make polymer building block with high selectivity when used as sorbent. The selection of suitable and precise functional monomer has been elaborated in this study. methacrylate acid, itaconic acid and acrylamide is then studies as functional monomer that will be chosen to give the best polymer performance as sorbent. From IR spectrum results, it can be concluded that polymer has been synthesized successfully. Peak at 1157 cm<sup>-1</sup> which is a peak of C-N bond from β-lactam ring support this statement. Finally, it can be concluded that methacrylate acid is the best functional monomer for making polymer as sorbent for meropenem</p>
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Garcia, Ana-Cruz, Juan-Vicente Durá, José Ramiro, Juan-Victor Hoyos, and Pedro Vera. "Dynamic Study of Insole Materials Simulating Real Loads." Foot & Ankle International 15, no. 6 (June 1994): 311–23. http://dx.doi.org/10.1177/107110079401500606.
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A new methodology of biomechanical analysis of materials for shoe inserts is presented. This methodology is based on the determination of the loads applied to the materials in real situations and its simulation by means of a dynamic testing machine. Both the rigidity and the energy-absorbing characteristics of the materials are investigated as a function of frequency. This methodology is applied to the study of several commercially available viscoelastic materials intended for shoe inserts in the treatment and prevention of degenerative joint diseases. The influence of thickness is investigated as well as the frequency-dependent behavior of the materials studied. Significant differences between materials and different behavior as a function of thickness and frequency were found. Poron materials were found to have the lowest rigidity, good for adequate pressure distribution, while Noene showed the highest energy absorption. A careful selection of the thickness of Sorbothane was found to be necessary for avoiding flattening of the material.
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Tuomisto, Jussi. "Sopimustuotannon mahdollisuudet ja rajoitteet poronlihamarkkinoilla." Suomen Maataloustieteellisen Seuran Tiedote, no. 23 (January 31, 2008): 1–6. http://dx.doi.org/10.33354/smst.77020.
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Horisontaalinen, eli porotilojen välinen yhteistyö on voimakasta, mutta vertikaalinen,eli porotilojen, teurastamojen, ja vähittäiskauppojen välinen yhteistyö on vähäistä ja sirpaloitunutta.Yhteistyön sirpaloituminen sai alkunsa Poro ja Riista Oy:n konkurssista vuonna 1989. Samaanaikaan poronlihan hinta laski lähes 40 %. Vaikka ylisuuret poronlihavarastot on saatu purettua,näillä ei kuitenkaan ole saatu nostettua poronlihan tuottajahintaa. Myös poronlihan suoramyynti onlisääntynyt ja poronlihan jatkojalostus on menettänyt suurtuotannon edut.Sopimustuotanto poronlihan ostajien kanssa on lyhytjänteistä. Osa poromiehistä näkee, ettäpaliskunta on liian jäykkä organisaatio markkinoiman poronlihaa. Silloin pelkästään lihan hintavaikuttaa ostajan päätöksentekoon ja laatu jää toisarvoiseksi tekijäksi. Paliskunnan kauttamyytävässä porossa ei ole myöskään hintatakuuta. Hinta sovitaan usein vain yhdeksi kaudeksikerrallaan.Kun poro kasvatetaan, ruokitaan, teurastetaan ja usein myös markkinoidaan paliskunnissakeskitetysti yhteistyönä, on yksittäisen poromiehen vaikeaa vaikuttaa poronlihan laatuun. Tämähaitallisen valikoitumisen ongelma (adverse selection problem) laskee koko tarjontaketjun, myöskuluttajan, hyötyä. Laatuinformaatio ei silloin tavoita poron kasvattajaa. Kuluttaja ei myöskään tuletietoiseksi siitä, millainen on laadukas poronliha. Silloin kuluttajan päätöksissä ratkaisee ainoastaanhinta. Suoramyynnissä on keskitettyä yhteismyyntiä parempi mahdollisuus keskittyä laaduntuottamiseen.Erityiseksi ongelmaksi poronlihamarkkinoilla osoittautui oligopolihinnoittelu yhdistettynäepäsymmetriseen informaatioon: muutamalla poronlihan jatkojalostusyrityksellä on informaatioetu,joka antaa poronlihamarkkinoille hintasignaalin. Muut yritykset seuraavat tätä signaaliahinnoittelemalla poronlihan hinnan hieman korkeammaksi kuin hintasignaalin antaneet yritykset.Informaatioetua nauttivat yritykset tarjoavat muita etuja (sopimus)tuottajille, esimerkiksi porojenhakeminen elävänä erottelupaikasta, jolla ne asemoivat itsensä markkinoille. Vaihtoehtoiskustannusporojen teurastamiselle on keskimäärin 0,11 euroa lihakilolta.Keskitetyssä myynnissä poronlihan hinta lyödään lukkoon syksyllä. Alituotantotilanteessaporonlihasta on kuitenkin talven ja kevään aikana mahdollista saada korkeampi hinta. Korkeampihinta kannustaa suoramyyntiin ja vähentää kiinnostusta sopimustuotantoon.Porotalouden verotus myös rajoittaa sopimustuotantoa ja kannustaa poromiehiä lisäämäänsuoramyyntiä. Poronlihan myynnissä keskitetysti paliskunnan kautta poromies sai kaudella 2006–2007 keskimäärin 4,50 euroa poronlihakilosta. Poron tai poronlihan myynnistä saatu arvonlisäverojää paliskunnan käyttöön, jolloin siitä saatava korkohyöty menee paliskunnalle eikä poromiehelle.Suoramyynnissä poromies saa 5-8 euron keskihinnan poronlihakilosta. Samalla arvonlisävero jääporomiehen käyttöön, jolloin arvonlisäverosta muodostuva korkohyöty tulee poromiehen käyttöön.Suoramyynnistä poromies ei maksa myöskään myyntiveroa, vaan paliskunnan kautta eloporojenkeskimääräisen tuoton mukaan. Verojärjestelmä ei kannusta poromiestä itse investoimaanporotalouteen, koska investoinnista koituvat verovähennyshyödyt menevät paliskunnan yhteiseksihyödyksi. Tämä lisää kiinnostusta suoramyyntiin ja omaan jatkojalostukseen.Varsinaista poronkasvatustyötä tekevät poromiehet kokevan pienimuotoisen jatkojalostuksenongelmallisena, koska poronhoitotyöt jäävät silloin yhä pienemmälle työvoimalle.
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Pakade, V. E., E. M. Cukrowska, J. Darkwa, G. Darko, N. Torto, and L. Chimuka. "Simple and efficient ion imprinted polymer for recovery of uranium from environmental samples." Water Science and Technology 65, no. 4 (February 1, 2012): 728–36. http://dx.doi.org/10.2166/wst.2012.911.
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Ion imprinted polymer material (IIP) was prepared by forming ternary complexes of uranyl imprint ion with 1-(prop-2-en-1-yl)-4-(pyridin-2-ylmethyl)piperazine and methacrylic acid followed by thermal copolymerization with ethylene glycol dimethacrylate as the cross-linking monomer in the presence of 1,1′-azobis(cyclohexanecarbonitrile) initiator and 2-methoxy ethanol porogenic solvent. HCl solution (5 mol/L) was used to leach out the uranyl template ion from the IIP particles. Similarly, the control polymer (CP) material was also prepared exactly under the same conditions as the IIP but without the uranyl ion template. Various parameters such as solution pH, initial concentration, aqueous phase volume, sorbent dosage, contact time and leaching solution volumes were investigated. SEM, IR and BET-surface area and pore size analysis were used for the characterization of IIP and CP materials. The extraction efficiency of the IIP and CP was compared using a batch and SPE mode of extraction. The optimal pH for quantitative removal is 4.0–8.0, sorbent amount is 20 mg, contact time is 20 min and the retention capacity is 120 mg of uranyl ion per g of IIP. The IIP prepared demonstrated superior selectivity towards coexisting cations and therefore it can be used for selective removal of uranium from complex matrices.
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Carlquist, Sherwin, Edward L. Schneider, and Kevin F. Kenneally. "SEM Studies on Vessels in Ferns. 8. Platyzoma." Australian Journal of Botany 47, no. 2 (1999): 277. http://dx.doi.org/10.1071/bt97120.
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Using scanning electron microscopy (SEM), vessels are demonstrated for roots and rhizomes of Platyzoma microphyllum R.Br. Because vessels are not in simple linear series, but have tips in contact with tips of other vessels, vessel elements may have several end walls, and each of these can bear a perforation plate. Vessels in roots are narrow, but have wide perforations. In rhizomes, perforation plates have a wide range of morphology. The most notable of these involves displacement and, frequently, fusion of adjacent bars of secondary wall material, so that large perforations tend to alternate with narrow perforations or with two or three fused bars. Porose pit membranes are present in narrower perforations. The presence of wide perforations achieved by means of bar displacement characterises not merely Platyzoma, but other ferns as well: Microgramma and Phlebodium. These three genera of ferns experience marked fluctuation in water availability, so that not only are vessels of potential value for rapid conduction during brief periods of water availability, but the presence of perforation plates conducive to such rapid conduction is of theoretical selective advantage as well. Stelar fibres that bear crystals on external surfaces of walls are reported for roots of Platyzoma. Such fibres have not been reported hitherto for ferns.
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Madejski, Paweł, Paulina Krakowska, Edyta Puskarczyk, Magdalena Habrat, and Mariusz Jędrychowski. "Permeability determination in tight rock sample using novel method based on partial slip modelling and X-ray tomography data." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 6 (May 24, 2019): 3053–63. http://dx.doi.org/10.1108/hff-11-2018-0711.
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Purpose The purpose of the paper was the application of computational fluid dynamics (CFD) techniques in fluid flow using Maxwell’s equation for partial slip modelling, estimating the flow parameters, and selecting tangential momentum accommodation coefficient (TMAC) for tight rock samples in permeability calculations. Design/methodology/approach The paper presents a numerical analysis of fluid flow in a low-porosity rock sample by using CFD. Modelling results allowed to determine mass flow rates in a rock sample and to calculate permeability values using a modified Darcy’s equation. Three-dimensional (3D) geometrical model of rock sample generated using computed X-ray tomography was used in the analysis. Steady-state calculations were carried out for defined boundary conditions in the form of pressure drop. The simulations were applied taking into account the slip phenomenon described by Maxwell’s slip model and TMAC. Findings Values of permeability were calculated for different values of TMAC, which vary from 0 to 1. Results in the form of gas mass flow rates were compared with the measured value of permeability for rock sample, which confirmed the high accuracy of the presented model. Practical implications Calculations of fluid flow in porous media using CFD can be used to determine rock samples’ permeability. In slip flow regime, Maxwell’s slip model can be applied and the empirical value of TMAC can be properly estimated. Originality/value This paper presents the usage of CFD, Maxwell’s equation for partial slip modelling, in fluid flow mechanism for tight rock samples. 3D geometric models were generated using created pre-processor (poROSE software) and applied in the raw form for simulation.
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Helle, T., E. Pulliainen, and J. Aspi. "Sized-related changes in winter condition of male calves in reindeer." Rangifer 7, no. 1 (June 1, 1987): 2. http://dx.doi.org/10.7557/2.7.1.697.
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<p>Size-related changes in body condition of free-ranging male calves of semi-domesticated reindeer were studied in northern Finland from October 1983 to February 1984. In October-November, back fat depth or muscle fat percent correlated positively with the body size (=back length). In January, the highest means especially for muscle fat percent were found among medium-sized calves. Carcass weight and weight/back length ratio correlated positively with size, excluding February sample, where correlation for carcass weight was non-significant and for weight/back length ratio negative. Weight in the autumn correlated negatively with weight in February. Therefore, normalizing selection for body size (working against small and large phenotypes) is expected to occur in late winter. Small calves may be at greater mortality risk because of lower initial body reserves. Large calves commonly disperse during the rutting season and they may suffer most from increased food competition later in winter. Using of medium-sized calves for breeding might be the safest policy on ranges characterized by short food supply and difficult snow conditions.</p><p>Koon vaikutus poron urosvasojen talviseen kuntoon.</p><p>Abstract in Finnish / Tiivistelmä: Koon vaikutusta vapaana laiduntavien poron urosvasojen kuntoon tutkittiin Pohjois-Suomessa loka-helmikuussa talvella 1983-84. Loka-marraskuussa selkärasvan paksuus tai lihaksen rasvaprosentti riippui vasan koosta ( = selän pituus). Tammikuussa sen sijaan lihaksen rasvaprosentti oli korkein keskikokoisilla vasoilla. Ruhopaino sekä ruhopaino/selän pituus oli yleensa riippuvainen koosta. Helmikuussa ruhopainon riippuvuus koosta ei ollut enää tilastollisesti merkitsevä, ja koon ja ruhopainon/selänpituuden välinen korrelaatio oli negatiivinen. Eniten painoa menettivät (%) loka-helmikuun välillä suurikokoisimmat vasat. Havainnot viittaavat siihen, että talvella esiintyvä kuolleisuus on normalisoivaa koon suhteen (karsii pieniä ja suuria fenotyyppejä). Pienten vasojen kuolleisuusriski on suuri alunperinkin vähäisen varastoravinnon vuoksi. Suuret vasat puolestaan erkaantuvat usein emistään jo rykimäaikana, ja joutuvat kärsimään eniten talven mittaan kiristyvästä ravintokilpailusta. Niukoilla laitumilla siitokseen on turvallisinta säästää keskikokoisia vasoja.</p><p>Sammenhengen mellom størrelse og vinterkondisjon hos hankalver av reinsdyr.</p><p>Abstract in Norwegian / Sammendrag: Størrelses-relaterte forandringer i kroppskondisjon hos fritt beitende han-kalver av semidomestiserte rein er studert i Nord-Finland fra oktober 1983 til februar 1984. I oktober - november korrelerte tykkelsen av ryggfettet eller muskelfett-prosenten positivt med kroppsstørrelsen (= rygglengden). I januar ble de høyeste middelverdier, særlig for muskelfett-prosenten, funnet hos kalver av middels størrelse. Skrott-vekter og vekt/rygglengde-forholdet korrelerte positivt med kroppsstørrelse bortsett fra februar-prøvene, der korrellasjonen for skrott-vekt var ikke-signifikant og for vekt/rygglengde-forholdet var negativt. Vekt om høsten korrelerte negativt med vekt i februar. Derfor ventes et normaliserende utvalg for kroppsvekt (som arbeider mot små og store fenotyper) å skje på senvinteren. Små kalver er utsatt for større dødsrisiko på grunn av lavere kroppsreserver. Store kalver streifer vanligvis under brunsttiden og kan komme til å lide under økt næringskonkurranse på senvinteren. Bruk av middels store kalver i avlen kan være den sikreste metode på beiter som karakteriseres av dårlige næringstilgang og vanskelige snøforhold.</p>
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Hroboňová, Katarína, Andrea Spevak, Ľubica Spišská, Jozef Lehotay, and Jozef Čižmárik. "Application of umbelliferone molecularly imprinted polymer in analysis of plant samples." Chemical Papers 67, no. 5 (January 1, 2013). http://dx.doi.org/10.2478/s11696-013-0320-1.
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AbstractThe molecularly imprinted polymers (MIPs) were synthesised and the influence of the type of porogen, the nature of sample solvent, and the binding capacity of material were tested by high-performance liquid chromatography (HPLC). Umbelliferone was used as the template for imprint formation. Methacrylic acid was used as the monomer and acetonitrile, ethanol, and chloroform as porogen. Non-imprinted polymers (NIPs) were prepared by the same procedure. The highest value of the specific binding capacity (269 μg of umbelliferone per 100 mg of polymer) was obtained for polymers prepared in chloroform as porogen and methanol/water (φ r = 1: 1) as the sample solvent. The group-selective MIP was used as sorbent for the SPE pre-treatment of umbelliferone from plant extracts prior to HPLC analysis. Analysis of the spiked samples showed good recoveries (> 77 %). The limit of detection, limit of determination, and repeatability of the method were also calculated.
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Dickert, Franz L., Peter A. Lieberzeit, Sylwia Gazda-Miarecka, Konstantin Halikias, and Roland Bindeus. "Imprinting with Chemical Sensors - Challenges in Molecular Recognition and Universal Application." MRS Proceedings 787 (2003). http://dx.doi.org/10.1557/proc-787-g5.4.
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ABSTRACTMolecular imprinting leads to functional polymers that are capable to incorporate the template used and thus lead to selective chemical sensor systems when combined with a suitable transducer. Benzene and xylene can e.g. be distinguished with a selectivity factor of nearly ten using mass-sensitive devices such as QCM and SAW, although they both contain an aromatic system and differ only by the methyl groups. Sensing materials are further tuned by using binary mixtures as templates. When analyzing polycyclic aromatic hydrocarbons (PAH) by fluorescence and QCM measurements, the sensitivity is substantially increased if a second template molecule is applied as a porogen. Capacitive sensor measurements on polymers imprinted with microorganisms, such as yeasts, show substantial sensor responses due to highly selective inclusion compared with a non-functionalised surface yielding only negligible effects.
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Madikizela, Lawrence Mzukisi, Silindile Senamile Zunngu, Nomchenge Yamkelani Mlunguza, Nikita Tawanda Tavengwa, Phumlane Selby Mdluli, and Luke Chimuka. "Application of molecularly imprinted polymer designed for the selective extraction of ketoprofen from wastewater." Water SA 44, no. 3 July (July 31, 2018). http://dx.doi.org/10.4314/wsa.v44i3.08.
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A molecularly imprinted polymer (MIP) that is selective to ketoprofen was synthesized and applied in the adsorption of the target compound from water. The MIP was synthesized using a bulk polymerization method at high temperatures (60–80°C), where ketoprofen, 2-vinylpyridine, ethylene glycol dimethacrylate, toluene and 1,1´-azobis(cyclohexanecarbonitrile) were used as template, functional monomer, cross-linker, porogen and initiator, respectively. Non-imprinted polymer (NIP) was synthesized similarly to the MIP but in the absence of ketoprofen. From molecular dynamics simulation, the nature of interactions that occurred between the template and the functional monomer were found to be based on hydrogen bonding. This was confirmed experimentally, where a high extraction efficiency of ≥ 90% was obtained at acidic conditions (pH 5) due to the protonation of ketoprofen. A contact time of 45 min was sufficient for the maximum adsorption of ketoprofen from 10 mL spiked water using 8 mg of the adsorbent. MIP showed greater selectivity than NIP by achieving a relative selectivity coefficient of 7.7 towards ketoprofen in the presence of structurally related pharmaceuticals. Furthermore, the order of sorption onto the MIPs from water was ketoprofen > fenoprofen > gemfibrozil. From a modelling perspective, the Langmuir adsorption isotherm and pseudo-second-order kinetic model gave the best fit, with maximum adsorption capacity of 8.24 mg·g−1 and sorption rate constant of 0.25 mg·g−1·min−1 for MIP. This was translated to chemisorption of ketoprofen onto the homogeneous MIP binding sites. This work demonstrated the great potential of MIP in selective recognition of ketoprofen from wastewater relative to closely related compounds.
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Kumpula, Jouko, and Alfred Colpaert. "Snow conditions and usability value of pastureland for semi-domesticated reindeer (Rangifer tarandus tarandus) in northern boreal forest area." Rangifer 27, no. 1 (January 28, 2009). http://dx.doi.org/10.7557/2.27.1.171.
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We studied variation in snow conditions and selection of pasture area according to altitude by semi-domesticated reindeer (Rangifer tarandus tarandus) during 1999 - 2002 in a pine forest area utilised by forest industry in the Ivalo reindeer herding district, northern Finland. Snow conditions were measured over the course of three winters along equilateral triangles (side 3.5 km) for three times per winter. The altitudinal selection of pasture area by reindeer was studied using GPS tracking data (10 977 locations) from 29 female reindeer. We observed that interannual weather variation mostly affected the depth, density and hardness of snow in the study area. At the forest landscape level, snow depth and density increased with altitude. Thinnest and deepest snow cover occurred on western and northern slopes, respectively. In contrast, forest harvesting did not seem to affect snow conditions. From spring to autumn, reindeer mainly used higher altitudes in pastures. In early and mid-winter, when snow conditions were easy or moderate reindeer still preferred higher altitudes, but in late winter when snow conditions and food accession were at their most difficult, they preferred lower altitudes. We conclude that especially the use of high elevation forestland pastures may become more difficult for reindeer if the global climatic change causes higher winter precipitation to the northern boreal forest area. In general, the low-elevation forestland areas have primary winter grazing value for reindeer but these areas are also intensively used by forest industry.Abstract in Finnish / Tiivistelmä:Lumiolosuhteet ja laidunten käyttöarvo poronhoidossa pohjoisella havumetsäaluella Lumiolosuhteiden vaihtelua ja porojen (Rangifer tarandus tarandus) laidunalueen valintaa maaston korkeuden perusteella tutkittiin vuosina 1999–2002 metsätalouden hyödyntämällä mäntymetsäalueella Ivalon paliskunnassa, Pohjois-Suomessa. Lumiolosuhteet mitattiin kolme kertaa kunakin kolmena talvena käyttämällä mittaukseen tasasivuisia kolmioita (sivu 3,5 km). Porojen laidunalueen valintaa korkeusvyöhykkeen mukaan tutkittiin käyttämällä porojen GPS seurannan aineistoja 29 vaatimesta (yhteensä 10 977 paikannusta). Vuosien välinen säävaihtelu vaikutti eniten lumen paksuuteen, tiheyteen ja kovuuteen tutkitulla alueella. Maisematasolla lumen paksuus ja tiheys lisääntyivät alueen korkeuden kasvaessa metsämaalla. Ohuin lumikerros mitattiin länsirinteillä ja paksuin kerros pohjoisrinteillä. Sen sijaan metsien käsittelyllä ei näyttänyt olevan vaikutusta lumiolosuhteisiin. Keväästä syksyyn porot käyttivät pääosin ylemmillä korkeusvyöhykkeillä sijaitsevia laitumia. Alku ja keskitalvella, jolloin lumiolosuhteet olivat vielä verrattain helpot, porot suosivat edelleen ylemmille korkeusvyöhykkeille sijoittuvia laitumia, mutta lopputalvella lumiolosuhteiden ja ravinnonsaannin ollessa vaikeimmat, porot suosivat alempien korkeusvyöhykkeiden laitumia. On todennäköistä, että erityisesti ylemmillä korkeusvyöhykkeillä olevat metsämaan laitumet voivat tulla vaikeammaksi käyttää poroille talvella, mikäli ilmastonmuutos aiheuttaa talvisadannan lisääntymisen pohjoisella havumetsäalueella. Yleisesti alemmille korkeusvyöhykkeille sijoittuvilla metsämaan laidunalueilla on ensisijainen talvilaidunarvo poronhoidolle, mutta myös metsätalous hyödyntää näitä alueita intensiivisesti.Abstract in Norwegian / Sammendrag:Snøforhold og bruksverdi som beiteland for tamrein (Rangifer tarandus tarandus) i nordborale skogsområder I perioden 1999-2002 studerte vi tamreinens valg av beiteområder ettersnøforhold og høyde over havet i en furuskog utnyttet av skogsdriften i Ivalo reinbeitedistrikt nord i Finland. Snøforholdene ble målt 3 ganger per vinter i tre vintre etter likebeinte triangler med side 3,5 km. Reinens beiting i ulike høyder ble målt med GPS-sporing av 29 simler på tilsammen 10 977 observasjonspunkter. Vi observerte at værvariasjonen mellom år mest påvirket snødybde og snøens tetthet og hardhet. I skogslandskapet økte snødybden og tettheten med høydebeliggenheten. Tynnest og djupest snødekke fantes henholdsvis i vestlige og nordlige skråninger. Derimot syntes ikke skogsdriften å påvirke snøforholdene. Fra vår til høst utnyttet reinen hovedsakelig de høyestliggende beiteområdene. Tidlig og midt på vinteren når snøforholdene fortsatt var lette eller moderate, foretrakk reinen fortsatt høyereliggende beiter, men på seinvinteren når snøforholdene og plantetilgjengeligheten var på det vanskeligste, foretrakk reinen lavereliggende områder. Ut fra observasjonene kan vi antyde at særlig høyereliggende beiteområder blir mindre tilgjengelig for reinen om det blir økt vinternedbør i de nordlige skogsområdene som følge av globale klimaendringer. Vanligvis har de lavtliggende skogsområdene størst beiteverdi for reinen om vinteren, samtidig som disse områdene også er de mest intesivt utnyttede hogstområder for skogsindustrien.
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Amin, Saeful, Sophi Damayanti, and Slamet Ibrahim. "Synthesis and Characterization Molecularly Imprinted Polymers for Analysis of Dimethylamylamine Using Acrylamide as Monomer Functional." Jurnal Kefarmasian Indonesia, October 16, 2018, 76–84. http://dx.doi.org/10.22435/jki.v8i2.330.
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A selective separation techniques with Molecularly Imprinted Polymer (MIP) for High-Performance Liquid Chromatography (HPLC) has been developed for the assay of Dimethylamylamine (DMAA) doping compounds. Molecular imprinted polymer (MIP) is a technique to produce a polymer having the cavity due to the disposal of the templates, in which the cavity serves to recognize the molecules of the same size, structure, chemical and physical properties. The selectivity and affinity of the templates itself will increase, while the concentration value is increasing. MIP is made by DMAA as template, acrylamide as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross linking, azobisisobutyronitrile (AIBN) as the initiator and chloroform as a porogen solvent; using bulk method. The aim of research are conduct the MIP for the DMAA compound analysis, then the formed MIP is characterized by using Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) to find out the polymer complexes formed and the morphological form of the MIP. The MIP formed then was analyzed by using High-Performance Liquid Chromatography (HPLC) to know the amount of the DMAA, the adsorption capacity, and the adsorption condition found in the MIP. The result of analysis on the content of DMAA in the MIP by using UV-Vis Spectrophotometer is 1.957 mg. Scanning Electron Microscopy (SEM) shows that the MIP has irregular and rough morphological structure; while the NIP has irregular morphology structures and smooth surfaces shape