Academic literature on the topic '35.07 laboratory technique of chemistry'

Tuberculosis remains a major threat to world health. The main aim of this study was to improve the microscopic detection of AFB from sputum by Bleach sedimentation technique using household bleach. This was a cross sectional type of study conducted for a period of one year from July 2010 to June 2011 in the Department of Laboratory Services, Khwaja Yunus Ali Medical College Hospital (KYAMCH), Sirajgonj. A total of 115 clinically suspected tuberculosis patients aged between 7-85 years were included in the study. Among them 35 (30.4%) patients had TB positive by routine (Direct microscopy) method; whereas, by bleach concentration method 42 (36.5%) were found positive; diagnosing 07 additional patients. The rise of 16.7% in sputum positivity by bleach sedimentation microscopy over the direct smear microscopy was found to be statistically significant (p= <0.005). Paired samples t test analysis of sputum showed a significant correlation between this two methods (r=0.896, p <0.001). This study suggests that Bleach sedimentation method is better than direct conventional method. So it should be applied to all laboratories across the country because it is cheap early available and also safety to the laboratory staffs.KYAMC Journal Vol. 5, No.-2, Jan 2015, Page 497-502

Abstract A binary mixture of hyoscine butylbromide and ketoprofen was determined by 4 different methods. The first involved determination of hyoscine butylbromide and ketoprofen using the ratio-spectra first-derivative spectrophotometric technique at 211 and 234 nm over the concentration ranges of 2-14 and 5-45 μg/mL with mean accuracies 99.84 ± 0.92 and 99.98 ± 0.64%, respectively. The second method utilized second-derivative spectrophotometry over the concentration ranges of 2-14 and 5-35 μg/mL with mean accuracies 99.32 ± 1.06 and 99.55 ± 1.15%, respectively. The third method was based on the resolution of the 2 components by bivariate calibration depending on a simple and rapid mathematical algorithm and quantitative evaluation of the absorbances at 206 and 254 nm over concentration ranges of 2-16 and 5-35 μg/mL; mean accuracies of 100.21 ± 1.30 and 100.19 ± 1.07% were obtained for hyoscine butylbromide and ketoprofen, respectively. The fourth method was reversed-phase liquid chromatography using 0.05 M ammonium dihydrogen phosphateacetonitrilemethanol (20 + 30 + 6, v/v) as the mobile phase with ultraviolet detection at 220 nm over concentration ranges of 1-90 and 5-70 μg/mL; mean accuracies were 99.92 ± 1.02 and 99.61 ± 0.98%, respectively. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

This article presents an experimental study of estimating stresses in concrete by applications of coda wave interferometry to establish an acoustoelastic modulus database. Under well-controlled laboratory conditions, uniaxial load cycles were performed on three groups of 15 × 15 × 35-cm concrete prisms, with ultrasonic signals being collected continuously. Then, the coda wave interferometry technique, together with acoustoelastic and Kaiser theories, are utilized to analyze the stress-velocity relations for the distinct ranges before and after historical maximum loads, forming an acoustoelastic modulus database. When applied to different concrete samples, their stresses are estimated with a high degree of accuracy. This study could be used to promote the development of novel nondestructive techniques that aid in structural stress monitoring.

In this study, a powder mixture consisting of TiC (titanium carbide) and WC (tungsten carbide) reinforced AlCuNiFeCr was produced using the hot pressing technique. The AlCuNiFeCr powder mixture, TiC and WC were added at a rate of 5 %, 10 % and 15 %, respectively. In order to produce and control to produce parameters have been produced having automation systems type of laboratory a hot pressing machine. Graphite moulds were used in production and sintering processes were carried out in a protective argon gas atmosphere. Composites were produced at a sintering temperature of 900?C and under a pressure 35 MPa and for 4 minutes. To understand the microstructure and mechanical properties of produced specimens, their SEM and EDS analysis, XRD analysis, fracture surface SEM images, SEM mapping of elemental distribution and EDX spectrums, hardness, three-point bending, and corrosion tests were investigated. As a result, the best sample has been identified that belong to AlCuNiFeCr-15 % WC with great features.

Dosage regimens of drugs that are cleared mainly by glomerular filtration as well as fluid management in preterm infants should be based on the glomerular filtration rate (GFR) of the individual patient. However, GFR measurements and collection of urine in newborns are difficult to perform. The 24 to 48 h continuous inulin infusion technique does not require the collection of urine and is considered the most reliable indicator of GFR.1,2 This method is invasive, time-consuming, and expensive. In contrast, serum creatinine measurements can be obtained easily and determined quickly in the clinical chemistry laboratory. Most laboratories use an automated kinetic Jaffé method, which is subject to negative interference by plasma hemoglobin above 0.06 mmol/L, and to negative interference by bilirubin (about 35 µmol/L by a serum bilirubin of about 100 µmol/L).

Abstract Abstract 747 Introduction: RUNX1 (runt-related transcription factor 1) deregulations constitute a disease-defining aberration in AML. RUNX1 mutations were proposed as clinically useful biomarkers to follow disease progression from MDS to s-AML, as well as to monitor minimal residual disease (MRD). Study design: First, a next-generation amplicon deep-sequencing (NGS) assay was developed and a validation study was performed on genomic DNA obtained from mononuclear cells on a longitudinal series of 116 retrospective samples obtained from 25 patients. These samples were collected between 11/2005 and 6/2010 and were characterized for RUNX1 mutations by DHPLC and Sanger sequencing (conventional methods). In median, 3,346 reads per amplicon were generated and in all cases NGS analyses concordantly detected the mutations known from conventional methods. Furthermore, in 2/25 (8%) cases, NGS detected additional low-level mutations with 0.9% and 3.2% of reads mutated that were not observed by standard Sanger technique. Concerning MRD monitoring, in 7/25 (28%) cases an increasing clone size, i.e. mutations as low as 0.2% - 7.0%, was detectable up to 9 months earlier than by conventional methods. This established assay then was applied to characterize an unselected prospectively collected cohort during the subsequent 12-months routine diagnostics period starting 07/2010. Results: In total, 2,705 NGS RUNX1 mutation analyses were performed on a variety of hematological malignancies. We report on analyses on 460 AML cases at diagnosis including 369 de novo AML, 57 s-AML, and 34 t-AML cases (median age: 68 years; females: 204; males 256). 51% of cases presented with a normal karyotype, 38% harbored non-complex cytogenetic alterations, 10% carried a complex aberrant karyotype, and 1% of patients were characterized by favorable cytogenetics. Overall, 141 RUNX1 mutations were observed in 24.3% (112/460) of cases. At diagnosis, the clone size ranged from 2% to 95% (median: 40%). 82% (92/112) of mutated patients carried one, whereas 18% (20/112) harbored two (n=17) or more (n=3) mutations. The 141 mutations were characterized as follows: 43% (60/141) frame-shift mutations, 34% (49/141) missense, 15% (21/141) nonsense, 5% (7/141) exon-skipping, and 3% (4/141) in-frame insertion/deletion alterations, respectively. The mutations were predominantly located in the RHD domain (54%) or TAD domain (20%). In subsequent serial NGS analyses 31/112 evaluable RUNX1 mutated cases were studied and in 88 individual samples the alterations detected at diagnosis were specifically investigated with high coverage. With a median sampling interval of 50 days for the NGS analyses between 2 and 9 samples per patient were analyzed during the first year of treatment. In this cohort, three categories of patients were detectable: (i) 55% (17/31) of patients responded to therapy and were characterized by a total clearance of the mutated clone at the first time point of follow-up (804-fold median sequencing coverage; sensitivity ∼1:800). (ii) A second group consisted of 10% (3/31) of patients with refractory disease that stayed mutated, but were excluded from further analyses since they underwent transplantation. (iii) The third group comprised 35% (11/31) of patients: None of these patients demonstrated a clone size reduction below 0.7% of reads at the first follow-up analysis (reduction to a median of 21% mutated reads; range 0.7% - 41%). Also, at the second time point (in median 108 days after initial diagnosis), mutated clones were still detectable (reduction to a median of 8% mutated reads; range 4% - 15%). Most of these cases (10/11) had refractory disease as assessed by cytomorphology or molecular analyses. 10/11 cases did harbor a normal karyotype; n=1 with del(7q). Further, 6 of these 11 patients with refractory disease, as defined using NGS, were found to carry RUNX1 double mutations. Finally, in all (3/3) cases with double mutations in the same domain and refractory disease a changing antiparallel distribution of the clone size from initial diagnosis to first follow-up was observed. Conclusions: NGS accurately detects and quantifies RUNX1 mutations in AML with high sensitivity. The technique of deep-sequencing was observed to be superior to current routine methods, in particular during follow-up and in detecting MRD and thus has the potential to enable an individualized monitoring of disease progression and treatment efficacy. Disclosures: Kohlmann: MLL Munich Leukemia Laboratory: Employment; Roche Diagnostics: Honoraria. Grossmann:MLL Munich Leukemia Laboratory: Employment. Harbich:MLL Munich Leukemia Laboratory: Employment. Dicker:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Nadarajah:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Spacecraft formation flying (SFF) in highly elliptical orbit (HEO) has attracted a great deal of attention in many space exploration applications, while precise guidance, navigation, and control (GNC) technology—especially precise ranging—are the basis of success for such SFF missions. In this paper, we introduce a novel K-band microwave ranging (MWR) equipment for the on-orbit verification of submillimeter-level precise ranging technology in future HEO SFF missions. The ranging technique is a synchronous dual one-way ranging (DOWR) microwave phase accumulation system, which achieved a ranging accuracy of tens of microns in the laboratory environment. The detailed design and development process of the MWR equipment are provided, ranging error sources are analyzed, and relative orbit dynamic models for HEO formation scenes are given with real perturbations considered. Moreover, an adaptive Kalman filter algorithm is introduced for SFF relative navigation design, incorporating process noise uncertainty. The performance of SFF relative navigation while using MWR is tested in a hardware-in-the-loop (HIL) simulation system within a high-precision six degrees of freedom (6-DOF) moving platform. The final range estimation errors from MWR using the adaptive filter were less than 35 μm and 8.5 μm/s for range rate, demonstrating the promising accuracy for future HEO formation mission applications.

Abstract Four accurate, sensitive, and reproducible stability-indicating methods for the determination of erdosteine in the presence of its acid degradation products are presented. The first method involves processing the spectra by using a first-derivative method at 229 nm in a concentration range of 10–70 μg/mL. The mean percentage recovery was 100.43 ± 0.977. The second method is based on ratio-spectra first derivative spectrophotometry at 227.4 and 255 nm over a concentration range of 10–70 μg/mL. The mean percentage recovery was 99.65 ± 1.122% and 100.02 ± 1.306% at 227.4 and 255 nm, respectively. The third method utilizes quantitative densitometric evaluation of the TLC of erdosteine in the presence of its acid degradation products, and uses methanol–chloroform–ammonia (7 + 3 + 0.01, v/v/v) asthe mobile phase. TLC chromatograms were scanned at235 nm. This method analyzes erdosteine in a concentration range of 2.4–5.6 μg/spot, with a mean percentage recovery of 100.03 ± 1.015%. The fourth method is HPLC for the simultaneousdetermination of erdosteine in the presence of its acid degradation products. The mobile phase consists of water–methanol (65 + 35, v/v). The standard curve of erdosteine showed good linearity overa concentration range of 10–80 μg/mL,with a mean percentage recovery of 99.90 ± 1.207%. These methods were successfully applied to the determination of erdosteine in bulk powder, laboratory-prepared mixtures containing different percentages of the degradation products, and pharmaceutical dosage forms. The validity of results was assessed by applying the standard addition technique. The results obtained agreed statistically with those obtained by a reported method, showing no significant differences with respect to accuracy and precision.

In recent years, the use of hop extracts in industrial and home brewing processes as an alternative to hop cones or pellets usually added to wort during boiling has become increasingly popular. These extracts represent concentrated sources of bitter compounds, i.e., α- and β-acids, which are involved in some of the main reactions that take place in the wort and are responsible for the bitterness and the final quality of beer. This work aims at proposing a novel extraction technique, using a hydrofluorocarbon solvent in subcritical conditions; this process provided an extraction yield of 19% and an α-acid recovery of approximately 49% in 120 min of process. The α-acid isomerization kinetics of thermally treated hop extracts were studied and compared with those of both hop pellets and a CO2 extract. Laboratory scale tests showed that shorter boiling times were needed using hydrofluorocarbon and CO2 extracts (approximately 25 min and 34 min, respectively) to reach the same isomerization efficiency of 16.73%, achieved in 50 min of boiling with pellets. Moreover, the process was scaled up and the possibility of considerably reducing the conventional treatment times using hydrofluorocarbon extracts was confirmed: the same isomerization yield (9.1%) obtained after 50 min using the traditional procedure with hop pellets was reached in a shorter time of approximately 35 min in a pilot apparatus.

Background: The criminal investigation starts at crime scene and ends in the laboratory. The most vital of which is mortuary where the postmortem examination of the deceased is carried out to answer the questions of interest in that investigatory menu. Aim: Unaided eye estimation of age from the lambdoid suture of skull on autopsy. Methods: The subjects under study were taken from mortuary of the department of Forensic Medicine and Toxicology in the King Edward Medical University Lahore during the year 2016. The targeted population for study was the draining are of the mortuary of King Edward Medical College having designated police station. A pretested questionnaire was used to collect the calculated sample among the research population as a research method. A non-probability convenient consecutive sampling technique was applied to collect the data. The comparative descriptive study design was utilized to analyze the results. Results: The study revealed that among the targeted population a higher percentage more than third of the sample size were adolescents of age between 21 – 30 years being 35% followed by elderlies of age between 41 – 50 years amount to 20%. The research depicted that age can be determined from degree of closure of lambdoid suture in the dead body on the autopsy table with closure taking place earlier in males as compared to that of females. Conclusion: This study concludes that it is possible to estimate age from the degree of lambdoid suture closure of the deceased skull vault during the postmortem examination. Keywords: Age, Lambdoid, Suture, Autopsy, Cranial, Post-mortem Examination, Skull

Abstract “Venturi-cascading” technique has been developed in the Combustion Laboratory at the University of Oklahoma. The goal was to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A propane jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, mid-flame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO2 concentration by 35%, 37%. and 32%, respectively, than the baseline flame. An opposite trend was noticed for O2 concentration; the cascaded flame has higher O2 concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The simulated results were compared with the experimental data. Good agreement was found in the near-burner region. However, the agreement was poor in the downstream regions. The numerical results substantiate the conclusion, which was drawn in the experimental part of this study, that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to interpret the experimental measurements and understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism plays an important role besides the conventional thermal-NO mechanism.