Academic literature on the topic 'Micro dosing'

SUMMARYThe effect of seed priming and micro-dosing in groundnut, cowpea and sesame was studied for three years in on-farm and on station experiments under rainfed agriculture in North Kordofan, Sudan. The on-station trials showed that seed priming increased groundnut pod and hay yields by 18% and 20% respectively. Micro-dosing of 0.3, 0.6 and 0.9 g fertilizer per pocket increased groundnut pod yield across the three years by 36.7, 67.6 and 50.8% respectively compared to the control. The highest yield increases were consistently obtained when micro-dosing was combined with seed priming. A combination of seed priming and micro-dosing of 0.6 g increased groundnut yield by 106%. Priming alone did not significantly affect sesame seed or hay yield, but micro-dosing of 0.6 g per pocket increased the grain yield by 38% over the control. Cowpea grain yield in the on-station experiments was not significantly affected by seed priming or micro-dosing. However, both seed priming and micro-dosing increased cowpea hay yield. In the on-farm trials, seed priming increased groundnut and cowpea yields by 18.2 and 25.5% respectively, and seed priming combined with 0.3 g fertilizer increased their yields by 42.2 and 54.5% respectively compared to the control. For sesame the yield increase after 0.3 g fertilizer per pocket was 46.3%. The economic analyses of the on-station experiments showed that the highest gross margin was obtained when combining seed priming with 0.6 g micro-dosing for all the crops. These results show that the combination of micro-dosing and seed priming has the potential to increase productivity and improve net return in the crops tested.

SUMMARYA study was carried out in the rainy seasons of 2008 and 2009 in Niger to investigate the effects of fertilizer micro-dosing on root development, yield and soil nutrient exploitation of pearl millet. Different rates of diammonium phosphate (DAP) were applied to the soil at different depths and it was found that although micro-dosing with DAP increased grain yield over the unfertilized control to a similar level as broadcast DAP, doubling the micro-dosage did not increase it further. Increasing the depth of fertilizer application from 5 to 10 cm resulted in significant increases in root length density, and deep application of fertilizer resulted in higher yields, although the increases were generally not significant. It was postulated that the positive effect of micro-dosing resulted from better exploitation of soil nutrients because of the higher root volume. Levels of nutrients exported from the soil were at least as high in plants receiving micro-dosing as the unfertilized control, and plants receiving micro-dosing exported 5–10 times more phosphorus from the soil than the amount added through fertilization.

Microdroplet dosing to cell on a chip could meet the demand of narrow diffusion distance, controllable pulse dosing and less impact to cells. In this work, we studied the diffusion process of microdroplet cell pulse dosing in the three-layer sandwich structure of PDMS (polydimethylsiloxane)/PCTE (polycarbonate) microporous membrane/PDMS chip. The mathematical model is established to solve the diffusion process and the process of rhodamine transfer to micro-traps is simulated. The rhodamine mass fraction distribution, pressure field and velocity field around the microdroplet and cell surfaces are analyzed for further study of interdiffusion and convective diffusion effect. The cell pulse dosing time and drug delivery efficiency could be controlled by adjusting microdroplet and culture solution velocity without impairing cells at micro-traps. Furthermore, the accuracy and controllability of the cell dosing pulse time and maximum drug mass fraction on cell surfaces are achieved and the drug effect on cells could be analyzed more precisely especially for neuron cell dosing.

Finger-millet response to micro-dosing with N and P fertilizer in the Semi-Arid areas of eastern Uganda is not fully known. Consequently, we conducted a field study at Kuju in eastern Uganda in 2016 long and short rains. The study determined the effect of fertilizer micro-dosing and weeding time on finger-millet performance. The experiment was laid out in a randomized complete block design with a split plot treatment structure. Weeding time constituted the main plot (weeding at 20, 30, 45 DAS (days after sowing) and 20 + 45 DAS while fertilizer rates (16.6 kg N ha-1 + 10.6 kg P2O5 ha-1; 10.6 kg P2O5 ha-1; 16.6 kg N ha-1; 0 N + 0 N and 83 kg N ha-1 + 52 kg P2O5 ha-1) constituted the sub-plots. Results of this study revealed that finger-millet grain yield was highest (2182 kg ha-1) at fertilizer micro-dosing (16.6 kg N ha-1 + 10.6 kg P2O5 ha-1) and lowest (950 kg ha-1) in plots with no fertilizer. Fertilizer micro-dose application (16.6 kg N ha-1 + 10.6 kg P2O5 ha-1) caused early flowering of finger-millet (52.2 days), whereas delayed flowering was recorded, where 16.6 kg N ha-1 (55.12 days) was applied. The interaction between time of weeding and fertilizer rates significantly (P < 0.05) increased finger millet growth and grain yield. The interaction of N and P fertilizer micro-dose with weeding once at 20 DAS had the highest finger-millet grain yield. Therefore, it is recommended that fertilizer micro-dosing can be used to enhance finger-millet productivity.

Oscillating positive displacement pumps are used in many industrial sectors. Mechanical stroke generators / drives such as crank drive, spring-cam drive etc have reached a high technological level, but to which are set mechanical limits. Especially in the smallest dosing range <1 l/h at a pressure range from 100 … 400 bar considerable optimisation is still required with regard to precision and continuity / control range of the dosing flow. In order to expand the current application possibilities for the diaphragm metering pump technology, it is necessary to use new drive systems such as linear motor technology. A linear motor is an electric drive unit which transmits the oscillating delivery movement of the dosing pumps directly to the displacer (hydraulic piston, diaphragm, etc.) without any mechanics, so that highly dynamic movements can be carried out with maximum precision, an individual kinematic profile and a control range of 1:200. The examples of gas odorization and filling processes show how the linear motor drive can be used to technologically solve and even optimize the customer's process requirements. The linear motor pump can realize an integrated 3-parameter control and is therefore suitable for almost any kinematically solvable dosing task.

Mikrodosering av psykedeliska droger är den senaste trenden som verkar ha fått en stor spridning, främst bland unga människor för att uppnå ökad produktivitet och kreativitet, men även för att uppnå allmän psykisk hälsa. Denna uppsats lägger fokus på lysergsyradietylamid (LSD) och psilocybin (magic mushroom). Mikrodosering innebär att användaren tar en väldigt låg dos av substansen. Dosen ger ingen psykedelisk effekt, d.v.s. inga visuella effekter, inget förändrat medvetandetillstånd,och ingen förändrad tids-eller rumsuppfattning. Deltagare (n=201) besvarade en elektronisk enkät som distribuerades i olika forum med intresse för psykedeliska substanser. I denna deskriptiva sambandsstudie undersöktes motiveringen av att mikrodosera LSD-och psilocybin, samt vilka positiva och negativa effekter mikrodosering av dessa substanser har på den psykiska hälsan.Deltagare uppgav upplevd minskad depression, ångest och stress, men att det inte var den primära anledningen till att de mikrodoserade trots att 62% hade självdiagnostiserat sig med någon form av upplevd ohälsa. De primära motiven med att mikrodosera, som angavs i enkäten, var att förbättra den allmänna hälsan, samt för att nå ökad kreativitet och produktivitet. Trots upplevda negativa bieffekter under mikrodoseringscykeln uppgav majoriteten att de ville fortsätta att mikrodosera. På grund av urvalet är studieresultatet inte generaliserbart och efterföljande undersökningar med hypoteser och frågor är att föreslå.

Cellular growth, development, differentiation, and death are mediated to some degree by the interaction of soluble factors with plasma membrane receptors. Traditionally the cellular response to chemical cues has been studied by exposing entire culture dishes to a desired reagent. While the addition of soluble reagents homogenously to cell culture dishes provides a basis for understanding much of cell biology, greater spatial resolution of reagent delivery is necessary in order to elucidate mechanisms on the subcellular scale. This dissertation explores techniques that may improve the quality and precision of delivering soluble factors to cultured cells in order to better understand the complex processes of cell biology. These advancements were made possible by applying high intensity, focused laser light to soluble materials to achieve microscopic three-dimensional (µ-3D) printing. In combination with a previously developed microfluidic cell dosing platform, microstructures were designed and µ-3D printed to hydrodynamically focus reagent streams for cell dosing. Structures were also µ-3D printed within micrometers of living cells from a solution of gelatin and bovine serum albumin with minimal cytotoxicity. When µ-3D printed, these proteins displayed both temperature and pH-responsive properties. In order to allow for on-the-fly control of reagent stream size and temporal pulse width, microstructures were µ-3D printed from temperature-responsive N- isoproplyacrylamide. To further improve the temporal resolution of the system, a technique for cycling between reagents with millisecond exchange times using laminar flow microfluidics was developed. The utility of these techniques was demonstrated by staining rat Schwann cells and mouse neuroblastoma rat glioma hybrid cells (NG108-15) with focused streams of fluorescent dyes. These advancements may allow future experiments to determine the placement of soluble factors necessary for bacterial quorum sensing or stem cell differentiation.
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Microelectromechanical systems (MEMS) technology has matured to the point where practical biological and chemical applications are possible. One particularly active research area is in the development of lab-on-a-chip type systems. In order to create successful lab-on-a-chip and other microfluidic systems, it is necessary to have the capability of controlling and directing fluid flow. Such functionality can be found on the front end of a microfluidic system and is known as a fluid delivery or dosing subsystem. For a MEMS micro fluid dosing system to be realized, several components are necessary. The essential components include a fluid actuator, a fluidic control device, and micro plumbing. A prototype fluid delivery system is demonstrated here using a micropump as the fluid actuator, a thermal flow sensor as the fluidic control device, and micromachined couplers as plumbing. The technology to build these components has been developed and each of these components have been fabricated and tested. A prototype constructed of discrete components has also been demonstrated. A truly integrated, channel-based fluid dosing system can be achieved through device scaling.

Background: Following years of inactivity, psychedelic research has rapidly expanded within clinical and therapeutic fields. In particular, magic mushrooms (psilocybin), a plant-based psychedelic, have been researched for the treatment of complex mental health and substance dependence conditions, and yielded promising results. Largely due to the historical baggage of the psychedelic movement in the 1950s-1970s, and the stigma of recreational substance use, recreational magic mushroom users have been ignored within the current psychedelic revival. This thesis addressed this gap, examining the magic mushroom recreational substance use patterns of emerging adults in Victoria, British Columbia. Theory and Methods: Using the normalization thesis as the guiding theoretical framework, this thesis used a sequential-exploratory mixed methods design. Statistical analysis of quantitative cross-sectional interviews (n=558) conducted between 2008 -2016 generated rates of use, availability, and self-rated knowledge rates of magic mushrooms users. Qualitative cross-sectional semi-structured interviews (n=20) analyzed through thematic analysis determined substance use behaviors with reference to the current social and cultural context. Participants were recreational magic mushroom users, aged 19- 24. Results: Quantitative results indicated high overall rates of lifetime and past year magic mushroom use, with the lowest reported prevalence rate of lifetime use occurring in 2014 (86%), suggesting high rates of use within the recreational substance using population. There were no statistically significant relationships between year and lifetime or past year rates magic mushroom use. Gender was statistically significantly associated with magic mushroom use, with males being more likely to use magic mushrooms. Qualitative results indicated dynamic and strategically planned magic mushroom experiences. Themes developed include: shifting understandings, optimizing experience, purpose driven use; and post-trip impact. Participants reported using for transformational, micro-dosing, and leisure purposes. Discussion: Results suggested that magic mushroom use is in the process of differentiated normalization and assimilative normalization, influenced by developmental, social and cultural forces. Recreational users report substance use practices that have not been widely reported with the substance use literature, including using small doses of magic mushrooms (i.e. micro-dosing) for self-enhancement and therapeutic purposes. Results can be applied to the current psychedelic revival in three ways: (1) directing future clinical research directions and; (2) provide lived and experience and relevancy to clinical research, which will improve applicability and; (3) re-conceptualizing the identity of a recreational substance user, which has important implications regarding stigmatization.
Graduate

Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.

Implantable drug delivery devices have shown promise for drug administration for management of several diseases spanning chronic diseases to emergency medicine as they overcome the limitations of continuous monitoring by medical physician or paramedical professional. Micro-electro mechanical systems (MEMS) technologies are they key enabling technology platform that allow fabrication of miniature devices with precise control over drug dosing rates. Recently, many of these technologies are also finding applications in microfluidic chips applications. MEMS are composed of microvalves, microchannels, microsensors, and micropumps within a miniaturized control device. Among these, micropumps play a dynamic role in determining the extent of control over drug dispensation. In this chapter, principles and developments of MEMS-based drug delivery systems with micropumps are presented, which may allow future development of affordable technologies based on this principle.

Indonesia is now entering the era of the digital economy. In the agricultural sector, the concept of Agricultural 4.0 was introduced as a form of digitization. The scope of agriculture in this chapter refers to the value chain of agricultural sector in utilizing information and communication technology for interaction between all stakeholders in the agricultural sector, where every activity is recorded so that they can make predictions, dosing, and tracing, with an automatic control system, and done remotely. Applying this technology will optimize results, both in quality and quantity as well as the efficiency of existing resources. The research on the transformation of the agricultural sector in the era of industrial Revolution 4.0 aims to study the digitalization strategy of the agricultural sector in the era of Technology 4.0. This research was carried out using a qualitative approach by conducting literature studies, in-depth interviews, and focus group discussions. This chapter recommends the development of micro farming financing to increase the scale of digital agriculture's economy.

Actualmente las enfermedades cardiovasculares representan la principal causa de morbimortalidad en el mundo; la aplicación de la nanotecnología es una gran promesa para su prevención y tratamiento. Actualmente se están desarrollando nanodispositivos para la liberación dirigida y controlada de medicamentos en sitios específicos en el organismo, por ejemplo, en células, tejidos, vasos sanguíneos y el corazón, así como para su diagnóstico, detección temprana de enfermedades cardiovasculares y tratamiento individualizado de pacientes. Otra aplicación de los nanodispositivos es la liberación de fármacos para corregir el mal acoplamiento de proteínas defectuosas. Con potentes superefectos, las nanopartículas deben ser capaces de provocar efectos terapéuticos a bajas dosis en periodos prolongados. La fabricación de nanodispositivos y nanoacarreadores deberá llevarse a cabo con un enfoque integral que tome en cuenta las propiedades generales, con la finalidad de evaluar la biocompatibilidad y, en consecuencia, evitar efectos adversos y tóxicos. La investigación intensificada en este campo ayudará a disminuir significativamente la morbimortalidad provocada por las enfermedades cardiovasculares. El presente trabajo incluye una sinopsis que describe algunos de los avances más recientes, relevantes y comunes de la nanomedicina en las ECV.

En las últimas décadas, la nanotecnología ha emergido como un área de investigación que está encontrando aplicaciones en múltiples campos. El mercado actual incluye nanomateriales que proporcionan grandes ventajas sobre los materiales en su forma convencional, una de éstas, su mayor área de contacto, lo que los hace ideales como sustancias catalíticas, mejorando este tipo de procesos con la consecuente reducción de insumos. Dentro de los nanomateriales comúnmente utilizados, las nanopartículas de oro se han aplicado principalmente en biomedicina, salud y belleza, sector automotriz y electrónica. Sin embargo, el uso cada vez más generalizado de nanopartículas no va aparejado con estudios sobre el impacto ambiental que conlleva la disposición final de sus residuos, especialmente en medios acuáticos, destino habitual de muchas sustancias utilizadas en procesos industriales, los cuales han sido poco estudiados. La presente investigación aborda el efecto que tienen las nanopartículas de oro con recubrimiento de quitosano sobre Daphnia pulex, microorganismos generadores primarios en la cadena trófica. Como resultado fundamental de este trabajo se estableció una dosis letal media (EC50) de 0.5721 mg/L de Au en este tipo de microorganismos, este estudio confirma así la importancia de llevar a cabo más investigación sobre la toxicidad de nanopartículas funcionalizadas, especialmente de oro, en organismos acuáticos microscópicos que son la base de muchas cadenas tróficas en ríos y lagos.

An electrolytic bubble actuated micropump has been fabricated and characterized for dosing application. The micropump consists of a series of bubbles formed directly inside a microfluidic channel, and the volume displacement characteristics of inflating/deflating electrolytic bubbles are utilized to move the liquid along the channel. Prototype chips with five sequential bubbles were built using standard photolithography techniques. The pump performance was characterized as a function of the voltage required to generate electrolytic bubbles of varying size (3.5–4.5 V), pulse-width (50–300 ms), time interval between pulses (50–300 ms), and backpressure; each parameter being varied independently. It was found that the size of the bubble, and hence the quantity of liquid displaced, increases with voltage. Also, the pump rate increases with a reduction in pulse-width and the time interval between pulses. The optimum pump rate of 24 nl/min, corresponding to a flow velocity of 640 μm/s, was obtained for the current channel size of 25×25μm in cross-section. The pump performed successfully against backpressures up to 107 kPa.

This paper deals with the theory, fabrication and characterization of micro diaphragm pumps with active valves. Three types of micropumps with piezoelectric actuation are presented. Special emphasis is given on the accordance of theory and experiment. The theory is based on a lumped-element approach that is reduced to its basics to enable a reasonable accuracy with a minimized set of conceptional parameters. The experimental results fit well to the theory. The fabrication technology of the micropumps comprises of a silicon bulk micromechanics process in combination with a back-end gluing process of piezoelectric PZT-disks (PZT lead-circonat-titanat) to the silicon diaphragms. The micropumps were developed for different applications. The three- and the four-diaphragm micropumps were designed as high performance drivers for an artificial sphincter prosthesis. They show a maximum flowrate of 4 ml/min and a maximum sustainable backpressure of up to 70 kPa. The two-diaphragm micropump was engineered for an implantable drug delivery device and features a pressure independent dosing for backpressures up to 20 kPa.

Accurate modeling of gas microvection is crucial for a lot of MEMS applications (micro-heat exchangers, pressure gauges, fluidic microactuators for active control of aerodynamic flows, mass flow and temperature micro-sensors, micropumps and microsystems for mixing or separation for local gas analysis, mass spectrometers, vacuum and dosing valves…). Gas flows in microsystems are often in the slip flow regime, characterized by a moderate rarefaction with a Knudsen number of the order of 10−2–10−1. In this regime, velocity slip and temperature jump at the walls play a major role in heat transfer. This paper presents a state of the art review on convective heat transfer in microchannels, focusing on rarefaction effects in the slip flow regime. Analytical and numerical models are compared for various microchannel geometries and heat transfer conditions (constant heat flux or constant wall temperature). The validity of simplifying assumptions is detailed and the role played by the kind of velocity slip and temperature jump boundary conditions is shown. The influence of specific effects, such as viscous dissipation, axial conduction and variable fluid properties is also discussed.

Electrochemical actuation is used to make active control elements for microfluidic applications that require no moving mechanical parts. Electrochemical bubbles were generated directly inside the micro-channels, which serve as valves. Bubble formation and its physical interaction with the fluid were visualized using epi-fluorescent microscopy, which shows that the valve completely stops the flow. Valve closing/opening was quantitatively characterized for flow rates ranging from ≈5 mm/s to 27 mm/s (inlet pressures 102 kPa to105 kPa). It was found that valves could be closed/opened in relatively short times (≈30 ms) and consume low power (≈10μJ). The current versus time curves measured at progressively higher voltages (from 3.8 V to 5.2 V) shows a linear relationship between the total charges transferred during electrolysis and the resulting bubble size. The large volume change associated with liquid to gas transformation can also be used to displace liquid for dosing or pumping.

Pupuk kandang ayam dan larutan mikroorganisme lokal daun gamal dapat meningkatkan hasil panen kacang hijau. Penelitian dosis pupuk kandang ayam dan konsentrasi larutan mikro organisme lokal (MOL) daun gamal yang optimal untuk meningkatkan hasil panen kacang hijau sangat diperlukan. Penelitian dilaksanakan di Kebun Percobaan dan Laboratorium Teknologi Benih Politeknik Negeri Jember pada Agustus 2015 sampai Desember 2015. Tujuan penelitian mengetahui pengaruh dosis pupuk kandang ayam dan konsentrasi MOL daun gamal terhadap hasil panen kacang hijau varietas Vima-1. Penelitian menggunakan RAK Faktorial. Faktor pertama adalah dosis pupuk kandang ayam terdiri atas tiga taraf yaitu dosis 250, 500 dan 750 gram/polybag. Faktor kedua adalah konsentrasi larutan MOL daun gamal terdiri atas tiga taraf yaitu 60, 90 dan 120 ml/liter. Kombinasi perlakuan diulang tiga kali. Analisis menggunakan ANOVA, dilanjutkan dengan uji DMRT. Hasil penelitian menunjukkan terdapat pengaruh interaksi antara dosis pupuk kandang ayam dan (MOL) daun gamal terhadap bobot basah, bobot kering, jumlah polong, bobot biji per tanaman, sedangkan Berat 100 Butir, daya Kecambah, kecepatan tumbuh dan keserempakan tumbuh menunjukkan berbeda tidak nyata. Dosis pupuk kandang ayam 250 g/polybag dengan konsentrasi MOL daun gamal 120 ml/l menunjukkan bobot basah, bobot kering, jumlah polong tertinggi. Aplikasi pupuk kandang ayam dengan MOL daun gamal dapat meningkatkan berat 100 Butir, daya Kecambah, kecepatan tumbuh dan keserempakan tumbuh benih kacang hijau.

Pengujian pupuk Fertila (12-6-24 +2MgO+3CaO+14SO3+unsur mikro) bertujuan untuk mengetahui pengaruh dosis pupuk terhadap kadar N, P, K daun, kadar sari buah, kadar asam dan total padatan terlarut, serta efektivitas pupuk terhadap hasil buah jeruk keprok Terigas. Percobaan ini dilaksanakan di IP2TP Kliran dan Laboratorium Ekofisiologi, Balai Penelitian Tanaman Jeruk dan Buah Subtropika, pada Agustus 2017. Tanaman yang digunakan adalah keprok Terigas yang diokulasi pada batang bawah Japansche Citroen berusia 4 tahun, dengan produksi tahun sebelumnya adalah 20 kg/pohon. Percobaan disusun menggunakan rancangan acak kelompok dengan 6 perlakuan, yaitu kontrol (tanpa pupuk), pupuk rekomendasi (0,60 kg Urea (45% N) + 0,50 kg SP36 (36% P2O5) + 0,10 kg KCl (60% K2O)/pohon), serta pupuk Fertila dengan dosis 1,50, 2,25, 3,00, dan 3,75 kg/pohon. Setiap perlakuan diulang 4 kali. Hasil penelitian menunjukkan bahwa aplikasi pupuk Fertila pada Inceptisol dengan status N tanah rendah, P tersedia dan K dapat ditukar sedang, berpengaruh nyata terhadap kadar N dan K daun jeruk. Fertila pada dosis tertinggi menghasilkan sari buah dengan total padatan terlarut lebih besar dibandingkan dengan pupuk rekomendasi, tetapi tidak berbeda nyata pada kandungan sari buah dan total asam tertitrasi. Kecuali dosis 1,5 kg/pohon (7,5% dari bobot panen sebelumnya), pupuk Fertila menghasilkan efektivitas hasil buah lebih dari 100% dan dosis pupuk optimum yang dianjurkan adalah 3 kg/pohon setahun.