Single Phase Fifteen Level Inverter using Seven Switches for Industrial Applications

This paper proposes a single-phase fifteen-level inverter using seven switches, with a novel pulse width-modulated (PWM) control scheme. The Proposed multilevel inverter output voltage level increasing by using less number of switches driven by the multicarrier modulation techniques. The inverter is capable of producing fifteen levels of output-voltage (Vdc, 6Vdc/7, 5Vdc/7, 4Vdc/7, 3Vdc/7, 2Vdc/7, Vdc/7,0, -Vdc/7,  -2Vdc/7, -3Vdc/7, - 4Vdc/7, -5Vdc/7, -6Vdc/7, -Vdc) from the dc supply voltage. A digital multi carrier PWM algorithm was implemented in a Spartan 3E FPGA. The proposed system was verified through simulation and implemented in a prototype

rac-Diethyl 5-oxo-2-[(2,4,4-trimethyl­pentan-2-yl)amino]-4,5-dihydro­pyrano[3,2-c]chromene-3,4-dicarboxyl­ate

The title compound, C26H33NO7, comprises a racemic mixture of asymmetric mol­ecules containing one stereogenic centre. The dihedral angle between the mean planes of the fused pyran ring and the coumarin ring system is 8.12 (14)°. The mol­ecular structure features a short N—H⋯O contact, which generates an S(6) ring motif. The crystal packing are stabilized by C—H⋯O inter­actions

rac-Dimethyl 2-(tert-butyl­amino)-5-oxo-4,5-dihydro­pyrano[3,2-c]chromene-3,4-dicarboxyl­ate

The title compound, C20H21NO7, is asymmetric with a chiral centre located in the pyran ring and crystallizes as a racemate. The mol­ecular framework is somewhat bent; the coumarin moiety and the pyran ring are inclined by 7.85 (5)°. The mol­ecular structure is characterized by an intra­molecular N—H⋯O hydrogen bond, which generates an S(6) ring motif, and the crystal packing is stabilized by inter­molecular C—H⋯O hydrogen bonds. The 3-carboxyl­ate O atom is involved in both of them, having a bifurcated character

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Design and synthesis of spirooxindole–pyrrolidines embedded with indole and pyridine heterocycles by multicomponent reaction: anticancer and in silico studies

Owing to the downsides of existing anticancer drugs, it is necessary to find more effective and selective anticancer agents for researchers in medicinal chemistry worldwide. Spirooxindoles are poised as privileged scaffolds because they exist in many natural products and bioactive molecules. Herein, we report an efficient, environment-friendly route for synthesizing a series of spirooxindoles using the 1,3-dipolar cycloaddition reaction of a dipolarophile with in situ generated azomethine ylide using ethanol as a solvent without any catalyst. The reaction offers potent biologically active spirooxindole fused with indole and pyridine heterocycles in good to excellent yield (69-94%) with higher diastereoselectivity. These synthesized compounds (4a-x) were screened for anticancer activity using A549, HepG-2, and SKOV-3 cancer cell lines using the MTT assay. Among all the screened compounds, 4u and 4w displayed substantial cytotoxic activity against HepG-2 cells at less than 10 μg mL−1. Molecular docking studies with the Bcl-2 and ALK receptor revealed that the higher binding energy was observed for 4u and 4w, and 4c and 4o with a value of −6.56 and −8.41, −6.73, and −7.14 kcal mol−1, respectively. Considering all the data, compounds 4u and 4w, 4c and 4o possess potent anticancer activity against respective receptors and can be the promising lead compounds for cancer drug discovery. © 2022 The Royal Society of Chemistr

Synthesis of Aliphatic Polyanhydrides with Controllable and Reproducible Molecular Weight

Polyanhydrides have been synthesized for decades by melt-polycondensation of diacid monomers and 5 to >10 times mole excess acetic anhydride to diacid monomers to form polymers with a polydispersity ranging from 2.5 to 6 and low reproducibility. Hydrophobic segments in polyanhydrides are beneficial to hinder the characteristic hydrolytic cleavage of an anhydride bond that provides stable polyanhydrides at room temperature. The objective of this work is to synthesize aliphatic polyanhydrides with various hydrophobic segments, controllable and reproducible molecular weight, and low polydispersity that are essential for potential use as drug carriers. A series of polyanhydrides of suberic, azelaic, sebacic, and dodecanedioic acids with controlled molecular weight, reduced polydispersity, and standard deviation of molecular weights, have been synthesized. All synthesized polyanhydrides were thoroughly characterized by NMR, Fourier transform infrared spectroscopy, and gel permeation chromatography. Molecular weights of the synthesized polyanhydrides are highly controllable, depending on the degree of activation of the dicarboxylic acid monomers, i.e., the amount of acetic anhydride used during synthesis. Polyanhydrides have been synthesized in triplicate by melt-polycondensation, using various mole ratios of acetic anhydride to diacids. The standard deviation of the molecular weights of the polyanhydrides is minute when using 1 equivalent of acetic anhydride during the activation of dicarboxylic acids, whereas if excess acetic anhydride is used, the standard deviation is very high. The effect of safe and natural inorganic catalysts, Calcium oxide, Zinc oxide, and Calcium carbonate on polymerization is also studied. As-synthesized poly(sebacic acid) can offer convenience to use in controlled drug delivery applications. In vitro drug release study using Temozolamide (TMZ), a medication used to treat brain tumors such as glioblastoma and anaplastic astrocytoma, shows 14% TMZ release after the first hour and 70% release over one day from the poly(sebacic acid) wafers

4′-(1H-Imidazol-2-yl)-3′-[(1H-indol-3-yl)carbonyl]-1′-methyl-2-oxospiro[indoline-3,2′-pyrrolidine]-3′-carbonitrile 0.15-hydrate

In the title compound, C25H20N6O2·0.15H2O, the dihedral angles between the least-squares planes of the indole and pyrrolidine rings and between the oxindole and imidazole rings are 77.66 (7) and 45.31 (7)°, respectively. The pyrrolidine ring and the fused five-membered pyrrolidine ring of the oxindole moiety exhibit twisted conformations. The amide N atom is involved in both intra- and intermolecular hydrogen bonding, having a bifurcated character. The molecular structure is characterized by an intramolecular N—H...O hydrogen bond, which generates an S(7) ring motif while an intermolecular N—H...O hydrogen bond links the organic and solvent water molecules. In the crystal, N—H...N hydrogen bonds generate a zigzag chain running parallel to c-axis direction. The H atoms of the solvent water molecule were not located

1-Ethyl-4′-(1H-indol-3-ylcarbonyl)-1′-methyl-2,2′′-dioxodispiro[indoline-3,2′-pyrrolidine-3′,3′′-indoline]-4′-carbonitrile dimethyl sulfoxide monosolvate

In the title compound, C31H25N5O3·C2H6OS, the three indole/indoline units are all essentially planar with maximum deviations of 0.0172 (3), 0.053 (2) and 0.07 (2) Å. The pyrrolidine ring adopts an envelope conformation with the C atoms bearing the 1-ethyl-2-oxoindole substituent (in which the five-membered ring adopts a twisted conformation) as the flap. The dimethyl sulfoxide solvent molecule is disordered over two positions, with an occupancy factor ratio of 0.871 (4):0.129 (4). The solvent components are linked to the heterocyclic molecule via C—H...O and C—H...S hydrogen bonds. In the crystal, the solvent components are linked to the heterocyclic molecule via C—H...O and C—H...S interactions, forming R22(10) ring motifs. The molecules are further connected into a chain along the a-axis direction via N—H...O hydrogen bonds

rac-Dimethyl 5-oxo-2-[(2,4,4-trimethylpentan-2-yl)amino]-4,5-dihydropyrano[3,2-c]chromene-3,4-dicarboxylate

The title compound, C24H29NO7, is asymmetric with a chiral centre located in the pyran ring and crystallizes as a racemate. The coumarin ring system and the fused pyran ring make a dihedral angle of 10.46 (8)°. A short intramolecular N—H...O hydrogen bond between the amino group and the vicinal carbonyl group generates an S(6) ring. Intermolecular C—H...O interactions contribute to the stability of the crystal structure

Multiphase hydrodynamic flow finishing for surface integrity enhancement of additive manufactured internal channels

The surface finishing of internal channels for components built using additive manufacturing is a challenge. The resulting surface finish uniformity of additive manufactured internal channels (such as fuel transfer lines and cooling passages) is an issue. Therefore, we propose a novel surface finishing technique using controlled hydrodynamic multiphase flow with abrasion phenomenon to overcome the challenges in the surface finishing of additive manufactured internal channels. In this study, we performed the internal surface finishing on AlSi10Mg components manufactured by direct metal laser sintering. We investigated the surface finish potential of the proposed hydrodynamic cavitation abrasive finishing (HCAF) by varying the process parameters, namely, the hydrodynamic upstream and downstream fluid pressures, fluid temperature, abrasive concentration, and processing time. The HCAF process resulted in greater than 90 % (Ra and Rz) surface finish improvements with an acceptable thickness loss from the internal channels. We precisely mapped the surface morphology transformation at the demarcated zones over the processing time and explained the material removal mechanism. In addition, we analyzed and discussed the surface integrity of the channels in terms of the microstructure, surface hardness, and residual stress. Furthermore, we performed large-area surface topography measurements. Then, we analyzed the resulting areal surface texture parameters to determine the uniformity and flatness of the surface after internal surface finishing. Finally, we discussed the significance of using the proposed HCAF process for complex additive manufactured internal channels.Accepted versio