2,282 research outputs found
Electron beam chemistry produces high purity metals
Application of radiation chemistry for deposition of metals by irradiation of aqueous solutions with high energy electrons is presented. Design of reaction vessel for irradiation of solution is illustrated. Features of radiochemical technique and procedures followed are described
Use of radiation in preparative chemistry
A summary and updating of previous work on the use of radiation chemistry for the preparation of pure materials are presented. Work was chiefly concerned with the reduction of metal salts in solution to the free metal using 2 MeV electrons. Metals deposited from aqueous solution are copper, silver, zinc, cadmium, thallium, tin, lead, antimony, iron, nickel, cobalt, and palladium. Dry organic solvents were evaluated for the deposition of metals based on a study involving deposition of antimony from soltions of antimony (III) chloride. The use of organic liquids for the preparation of anhydrous metal halides is also presented. Reaction mechanisms for both organic liquids and aqueous system are discussed
Hardware Implementaion of Image Acquisition system using FPGA & ARM
In this paper, image data acquisition system has been introduced. In this task, a system of high-speed image data acquisition based on ARM and FPGA is designed according to the needs of actual system in image data transmission, which can be used in data monitoring and surveillance systems. The choice of ARM is a 32-bit embedded RISC microprocessor architecture, which has a rich instruction set and programming flexibility. FPGA has a great advantage in the speed and parallel computing, suitable for real-time requirements of image processing. The interface between camera module and FPGA as well as interface between FPGA and ARM is done using UART. Image from ARM is transmitted to PC using Ethernet
A specific relationship between musical sophistication and auditory working memory
Previous studies have found conflicting results between individual measures related to music and fundamental aspects of auditory perception and cognition. The results have been difficult to compare because of different musical measures being used and lack of uniformity in the auditory perceptual and cognitive measures. In this study we used a general construct of musicianship, musical sophistication, that can be applied to populations with widely different backgrounds. We investigated the relationship between musical sophistication and measures of perception and working memory for sound by using a task suitable to measure both. We related scores from the Goldsmiths Musical Sophistication Index to performance on tests of perception and working memory for two acoustic features-frequency and amplitude modulation. The data show that musical sophistication scores are best related to working memory for frequency in an analysis that accounts for age and non-verbal intelligence. Musical sophistication was not significantly associated with working memory for amplitude modulation rate or with the perception of either acoustic feature. The work supports a specific association between musical sophistication and working memory for sound frequency
ICSI outcome in surgically retrieved sperm compared with ejaculated sperm control
Background: Globally, the prevalence of infertility is around 10% of the total population. 30% of these have male factor infertility. Azoospermia is found in 1% of men, in 20% of which, the etiology is a bilateral obstruction of the male genital tract while others have non obstructive azoospermia. In azoospermic men sperms are microsurgically retrieved from epididymis and testes by TESA and PESA respectively. The aim of this study was to evaluate the outcomes of intracytoplasmic sperm injection ICSI using surgically retrieved sperm of azoospermic men either obstructive or nonobstructive and to compare it with ejaculated sperms in men having severe oligospermia.Methods: This was retrospective cohort study conducted based on the data collected from our reproductive endocrinology and infertility unit, 126 ICSI cycles performed during the period of 5 years were taken and divided into two groups, one with patients having ejaculated sperms with oligospermia and other group with patients who had surgically retrieved normal sperms due to azoospermia. Outcome of these ICSI cycles included fertilization, cleavage, biochemical and clinical pregnancy was assessed.Results: In present study it was found that ICSI outcome was comparable in both the groups with ejaculated sperm and surgically retrieved sperm as fertilization rate (72% vs 65%), Implantation Rate (58 vs 51%), clinical pregnancy rate (CPR) (51% vs 44.82%) observed with ejaculated or retrieved sperm group respectively showed no statistical difference.Conclusions: Present study shows that minimally invasive techniques of PESA and TESA can be successfully performed to retrieve sperm for ICSI in the treatment of azoospermic men which gives them the chance to father their biological child. The result of this study indicates that treatment outcomes of PESA/TESA-ICSI cycles compare favourably with that of ICSI using ejaculated sperm
Classification of Rest and Active Periods in Actigraphy Data using PCA
In this paper we highlight a clustering algorithm for the purpose of identifying sleep and wake periods directly from actigraphy signals. The paper makes use of statistical Principal Component Analysis to identify periods of rest and activity. The aim of the proposed methodology is to develop a quick and efficient method to determine the sleep duration of an individual. In addition, a robust method that can identify sleep periods in the accelerometer data when duration, time of day varies by individual. A selected group of 10 individual\u27s sensor data consisting of actigraphy from an accelerometer (3-axis), near body temperature, and lux sensors from a single GENEActiv watch worn on the non-dominant hand. The actigraphy of each individual was collected 24 hours a day for a period spanning 80 days. We highlight that a simple data preprocessing stage followed with a 2 phase clustering method provides results that align with previously validated methodologies
Production of glucose from the acid hydrolysis of anhydrosugars
Acid hydrolysis of levoglucosan and cellobiose as anhydrosugar model compounds was carried out in an autoclave Parr reaction system, using sulphuric acid as catalyst. In addition, acid hydrolysis was carried out using an anhydrosugars mixture from the aqueous fraction of a pyrolysis oil or bio-oil. The bio-oil was obtained from the fast pyrolysis of birch-wood, and the segregated aqueous fraction was found to contain mainly levoglucosan with a concentration of 30 g L-1. Three main hydrolysis parameters including temperature, reaction time, and catalyst to substrate ratios were varied in order to identify their influence towards glucose production. It was found that at hydrolysis conditions of 120 °C, 60 minutes, and a catalyst/substrate ratio of 0.9; glucose yields of 98.55% and 96.56%, and conversion of substrates of 100% and ~92%, were achieved when hydrolysing cellobiose and levoglucosan respectively. An increase in the hydrolysis temperature from 120 °C to 135 °C, resulted in a decrease in the glucose yield and selectivity. Whereas high conversions of substrates (~90%) were maintained for both anhydrosugars. This was attributed to the further dehydration reactions of glucose, possibly yielding HMF or levulinic acid. During the acid hydrolysis of the bio-oil aqueous fraction, a range of hydrolysis conditions suitable to achieve glucose yields higher than 90%, was depicted. It was found that catalyst/substrate molar ratios between 0.17-0.90 and temperatures between 118 °C and 126 °C were suitable conditions to achieve glucose yields ~100% (30 g L-1). Furthermore, glucose concentrations ~117% (35 g L-1) and levoglucosan conversions above 90%, were attained at 135 °C, 20 minutes reaction time and at an estimated catalyst/substrate molar ratio of 0.2 (H2SO4, 0.5 M)
Monitoring of hepatitis B virus surface antigen escape mutations and concomitant nucleostide analog resistance mutations in patients with chronic hepatitis B
Background: In hepatitis B virus (HBV), reverse transcriptase (RT) region of the polymerase P gene and surface S gene (HBsAg) are largely overlapped. Mutations in surface S gene may cause escape variants. In the present study, we aimed to study the prevalence and pattern of the typical HBsAg escape mutations and concomitant nucleos(t)ide analogue resistance mutation patterns in patients with chronic hepatitis B (CHB) in Indian population.Methods: The present observational study was carried out from January 2021 to June 2022 with 156 known cases of CHB infection. Hepatitis B viral load quantitation was done followed by HBV genotyping and drug resistance detection by PCR and sequencing.Results: Out of 156 cases of CHB, HBsAg escape mutations were found in 50 (32.05%) patients. Genotype D was predominant (90%). Median viral load was 4.43×105 copies/ml. Total 128 HBsAg escape mutations of 46 different patterns were observed with overall prevalence of 29.49% (46/156) in CHB infected patients. The most common substitutions were sP127T (16.67%), sA128V (14.74%), sR122K (5.13%), sY134N (3.85%), sK141R (2.56%), sS143L (2.56%) and sT126INST (1.92%). Concomitant RT mutations were detected in 20 (40%) patients. Total 68 (43.59%) RT mutations of 18 different mutation characteristics were found conferring possible or confirmed resistance to nucleos(t)ide analogues.Conclusions: The emergence of drugs resistant mutants with alteration in ‘aa’ determinant of the S protein is of some concern. The development of novel nucleos(t)ide analogues with a high barrier to resistance is warranted. National surveillance networks should be set up
P05.45. A whole systems approach to the study of Ayurveda for cancer survivorship: results from a qualitative investigation
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