15 research outputs found
Experimental investigations of the effects of surfactants on droplet production by bubbles rising to a free surface.
Air bubbles traveling upwards from within a liquid, burst at the free surface and eject droplets into the air. The liquid droplets produced from the bursting of air bubbles at the free surface of the ocean have long been considered as constituting a significant fraction of the marine aerosol production. This process plays an important role in the transfer of mass and energy between the ocean and atmosphere. The droplets are generated by two distinct mechanisms which characterize the drops as either `jet droplets' or `film droplets.' The goal of this study is to obtain statistical data about the size of these droplets produced by air bubbles bursting on a non-quiescent free surface and study effects of surfactant on the droplet distribution. Two different surface conditions are created by using "clean" water and a 0.4% v/v aqueous solution of Triton X-100 surfactant. A bubble field is created with air injected through an array of hypodermic needles arranged in a grid pattern and five different bubble production rates are studied for each surface condition. Measurements of the bubble diameters as they approach the free surface are obtained with diffuse light shadowgraph images. A laser-light high-speed cinematic shadowgraph system is employed to record and measure the diameters and motions of the droplets. The movies are processed on a custom-built MATLAB code which measures droplets as small as 100 μm to within 7% error. Droplets with diameters between 50 and 100 μm are also measured, but with lower accuracy. The droplet size distributions as a function of the production rate and surfactant conditions are reported. The results show a clear distinction between the droplet distributions obtained in clean water and the surfactant solution. A bimodal droplet distribution is observed for clean water with at least two dominating diameter peaks. For the surfactant solution, a single distribution peak is seen
Sensitive and Rapid determination of Trientine and N1-Acetyl Trientine in Human Plasma by LC-MS/MS for bioequivalence study
A simple and robust method for simultaneous determination of Trientine and N1-Acetyl Trientine in human plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. The analyte and internal standard were extracted from 200 μL plasma by liquid phase extraction. Chromatographic analysis was carried out on column Xtimate, C18 (4.6 x 50 mm) 5 μm with a flow rate of 1 mL/min, at 40˚C temperature. An isocratic elution method was applied using (A) Acetonitrile - 80% and (B) 10mM Ammonium Acetate in water - 20%. Detection and quantitation was done by multiple reactions monitoring in positive ionization with Q3 LCMS-8050, Shimadzu. Mass parameters 1035.45/1030.55 m/z and 855.15/859.50 m/z on a triple quadrupole mass spectrometer were chosen for analysis of Trientine and N1-Acetyl Trientine. Linearity was established in human plasma covering the concentration range 10.009 ng/mL to 1000.571 ng/mL for Trientine and 10.009 ng/mL to 1000.628 ng/mL for N1-Acetyl Trientine. Correlation coefficient was consistently greater than 0.99 for Trientine and N1-Acetyl Trientine using Trientine-D4 and N1-Acetyl Trientine Trihydrochloride D4 as internal standards. Different parameters such as linearity, range, precision, accuracy, ruggedness and robustness, limit of detection (LOD) and limit of quantification (LOQ) were used for a full validation of this method. The results were found to be acceptable as per the guidelines of International Conference on Harmonization (ICH), CDER, EMA1,2,3,4,5. The developed and validated method was successfully applied to estimate Trientine and N1-Acetyl Trientine in a bioequivalence study in healthy human volunteers. Assay reproducibility was checked by reanalysis of samples near the Cmax and the elimination phase in the pharmacokinetic profile of the drug.
Keywords: Trientine and N1-Acetyl Trientine, LC-MS/MS, Validation, ICH
Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019
Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019.
Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019
An observational study of cutaneous manifestations in internal malignancy at tertiary care centre
Introduction: Skin is the largest organ in the human body and mirrors the changes in the organism it envelops. Internal malignancies can cause various specific and non-specific cutaneous manifestations along with hair, nail and oral mucosal changes. Some of the changes are detected early indicating a strong association with cancer, while some occur in later stage indicating dissemination or immunosuppression. The present study is an effort to know pattern of dermatosis associated with internal malignancies so that early diagnosis and interventions can be done. Aim: To determine the pattern of specific and non-specific dermatosis associated with internal malignancy. Methods and Material: Patients of internal malignancies with skin lesions attending dermatology and oncology department during July 2020 to June 2021 were recruited in the study after taking written informed consent. A detailed history of skin lesions and malignancies were taken. Clinical examination (skin/hair/nail) was carried out and photographs were taken. Relevant investigations were carried out. Frequency and percentage of dermographic data and dermatosis associated with internal malignancies were calculated. Results: The study included 150 patients with maximum number of patients 78 (52%) in 41-60 years of age group with female: male ratio of 1.2:1. Most common internal malignancy was breast carcinoma in 43 (28.67%) cases. Specific dermatosis were seen in 5 (3.33%) cases and non-specific dermatosis in 121 (80.66%) cases. Specific dermatosis were vasculitis, necrolytic migratory erythema, lymphocytoma cutis, growth and cutaneous metastasis with 1 (0.67%) patient each. Most common non-specific dermatosis was herpes zoster in 17 (11.33%) cases. Conclusion: The study was useful in understanding the various specific and non specific dermatosis associated with internal malignancies and thereby helping the physician to manage the conditions
ECRH experiments on Tokamaks SST-1 & Aditya-U and ECRH upgradation plan for SST-1
A 42GHz-500kW ECRH system [1-6] is used to carry out various experiments related to plasma breakdown and ECR heating on tokamaks SST-1 and Aditya-U. The system has been upgraded with new anode modulator power supply to launch two ECRH pulses to carry out breakdown and heating simultaneously. In SST-1, ECRH system is used routinely for plasma breakdown at fundamental harmonic, approximately 150kW power is launched for 70ms to 150ms duration and consistent plasma start-up is achieved in SST-1. In the recent experiments, second EC pulse is also launched at the plasma flat-top to heat the plasma, some heating signatures are seen but more experiments will be carried out to confirm the plasma heating with ECRH. In Aditya-U tokamak, simultaneous plasma breakdown and heating experiments are carried out successfully [2]. In the first pulse around 100kW power in fundamental O-mode is launched for 70ms duration for the breakdown at low-loop voltage and around 150kW ECRH power for 50ms duration is launched in second EC pulse to heat the plasma. In case of Aditya-U, plasma heating is observed clearly as soft X-ray signal increases sharply with ECRH. In AdityaU tokamak, deuterium plasma experiments have been carried out and ECRH launched at the flat-top of deuterium plasma current. In deuterium plasma also ECR heating is observed as soft X-ray signal increases with ECH power. For SST-1, ECRH system is being upgraded with another 82.6GHz system, this system would be used to carry out plasma heating and start-up at second harmonic. The 82.6GHz system is already connected with the SST-1 tokamak, the old 82.6GHz-200kW Gyrotron will be upgraded to 400kW system to carry out effective heating experiments on SST-1 at higher ECRH power. The paper discusses the recent results of ECRH experiments carried out on tokamaks SST-1 & Aditya-U and presents the upgradation plan of EC system for SST-1
Monodentate bulky trinaphthylphosphine as ligand in Rh, Co and Ru catalyzed hydroformylation of 1-hexene
27-32Rhodium,
cobalt, and ruthenium complexes of monodentate bulky trinaphthylphosphine
ligand, PNp3, have been synthesized and used as catalysts for the
hydroformylation of 1-hexene. The catalyst, RhCl(PNp3)3
shows excellent hydroformylation activity as compared to the Co/PNp3
and Ru/PNp3 system. The high conversion (99 %) with high selectivity
to aldehydes (97 %) is achieved by RhCl(PNp3)3 catalyst
whereas RuCl2(PNp3)3 is more active toward
hydrogenation rather than hydroformylation