Irritable bowel syndrome(IBS)is a common clinical label for medically unexplained gastrointestinal symptoms,recently described as a disturbance of the microbiota-gut-brain axis.Despite decades of research,the pathophy...Irritable bowel syndrome(IBS)is a common clinical label for medically unexplained gastrointestinal symptoms,recently described as a disturbance of the microbiota-gut-brain axis.Despite decades of research,the pathophysiology of this highly heterogeneous disorder remains elusive.However,a dramatic change in the understanding of the underlying pathophysiological mechanisms surfaced when the importance of gut microbiota protruded the scientific picture.Are we getting any closer to understanding IBS’etiology,or are we drowning in unspecific,conflicting data because we possess limited tools to unravel the cluster of secrets our gut microbiota is concealing?In this comprehensive review we are discussing some of the major important features of IBS and their interaction with gut microbiota,clinical microbiota-altering treatment such as the low FODMAP diet and fecal microbiota transplantation,neuroimaging and methods in microbiota analyses,and current and future challenges with big data analysis in IBS.展开更多
Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence ...Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.展开更多
AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided in...AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided into 2 groups based on their willingness to be listed for deceased donor liver transplant(DDLT)(control, n = 23) or to receive autologous CD34+ cell infusion through the hepatic artery(study group, n= 22). Patients in the study group were admitted to hospital and received granulocyte colony stimulating factor injections 520 μg/d for 3 consecutive days to mobilize CD34+ cells from the bone marrow. On day 4,leukapheresis was done and CD34+ cells were isolated using CliniMAC magnetic cell sorter. The isolated CD34+ cells were infused into the hepatic artery under radiological guidance. The patients were discharged within 48 h. The control group received standard of care treatment for liver cirrhosis and were worked up for DDLT as per protocol of the institute. Both groups were followed up every week for 4 wk and then every month for 3 mo.RESULTS: In the control and the study group, the cause of cirrhosis was cryptogenic in 18(78.2%) and16(72.72%) and alcohol related in 5(21.7%) and6(27.27%), respectively. The mean day 3 cell count(cells/μL) was 27.00 ± 20.43 with a viability of 81.84± 11.99%. and purity of 80%-90%. Primary end point analysis revealed that at 4 wk, the mean serum albumin in the study group increased significantly(2.83± 0.36 vs 2.43 ± 0.42, P = 0.001) when compared with controls. This improvement in albumin was,however, not sustained at 3 mo. However, at the end of3 mo there was a statistically significant improvement in serum creatinine in the study group(0.96 ± 0.33 vs 1.42 ± 0.70, P = 0.01) which translated into a significant improvement in the Model for End-Stage Liver Disease score(15.75 ± 5.13 vs 19.94 ± 6.68,P = 0.04). On statistical analysis of secondary end points, the transplant free survival at the end of 1 mo and 3 mo did not show any significant difference(P =0.60) wh展开更多
AIM: To investigate genetic susceptibility in Indian subjects with non-alcoholic fatty liver disease(NAFLD) by performing a pooled genetic study.METHODS: Study subjects(n = 306) were recruited and categorized into NAF...AIM: To investigate genetic susceptibility in Indian subjects with non-alcoholic fatty liver disease(NAFLD) by performing a pooled genetic study.METHODS: Study subjects(n = 306) were recruited and categorized into NAFLD and control groups based on ultrasound findings of fatty infiltration. Of the 306 individuals, 156 individuals had fatty infiltration and thus comprised the NAFLD group. One hundred and fifty(n = 150) individuals were normal, without fatty infiltration of the liver, comprising the control group. Blood samples, demographic and anthropometric data from the individuals were collected after obtaining informed consent. Anthropometric data, blood glucose, lipids and liver function tests were estimated using standard methods. Genome wide association stud-ies done to date on NAFLD were identified, 19 single nucleotide polymorphisms(SNPs) were selected from these studies that were reported to be significantly associated with NAFLD and genotyping was performed on the Sequenom platform. Student's t test for continuous variables and χ2 test was applied to variant carriers from both groups. Required corrections were applied as multiple testing was done.RESULTS The mean age of the control group was 39.78 ± 10.83 and the NAFLD group was 36.63 ± 8.20 years. The waist circumference of males and females in the control and NAFLD groups were 80.13 ± 10.35; 81.77 ± 13.65 and 94.09 ± 10.53; 92.53 ± 8.27 respectively. The mean triglyceride and alanine transaminase(ALT) levels in the control and NAFLD groups were 135.18 ± 7.77; 25.39 ± 14.73 and 184.40 ± 84.31; 110.20 ± 67.05 respectively. When χ2 test was applied to the number of individuals carrying the variant risk alleles between the control and NAFLD group, a significant association was seen between rs738409 of the patatin-like phospholipase domain containing 3(PNPLA3) gene(P = 0.001), rs2073080 of the PARVB gene(P = 0.02), rs2143571 of SAMM50 gene(P = 0.05) and rs6487679 of the pregnancy zone protein(PZP) gene(P = 0.01) with the disease. Variant single 展开更多
A set of borophosphate glasses doped with alkali and transition metal (TM) ions have been synthesized. The glasses were carried through;annealing, XRD, density, DC conductivity studies. Molar volume and density varied...A set of borophosphate glasses doped with alkali and transition metal (TM) ions have been synthesized. The glasses were carried through;annealing, XRD, density, DC conductivity studies. Molar volume and density varied nonlinearly. High temperature activation energy is analysed taking into consideration of Mott’s SPH model. The low temperature electrical conductivity was analysed by Mott and Greaves VRH. Several polaron hopping related parameters at high temperature region and density of states at low temperature region were computed. The high temperature DC activation energy measured by conductivity, calculated numerous pertained parameters varied nonlinearly with mole fraction of vanadium content. The Study exhibits DC electrical conduction is due to both alkali and transition metal ions and thus confirms the mixed conductivity. A crossover conduction mechanism from the ionic dominant region to polaronic predominant region has been also observed. Studies revealed the single transition effect at 0.4 mol fraction of V<sub>2</sub>O<sub>5</sub> content.展开更多
BACKGROUND We previously reported national 30-d readmission rates of 27% in patients with decompensated cirrhosis(DC).AIM To study prospective interventions to reduce early readmissions in DC at our tertiary center.ME...BACKGROUND We previously reported national 30-d readmission rates of 27% in patients with decompensated cirrhosis(DC).AIM To study prospective interventions to reduce early readmissions in DC at our tertiary center.METHODS Adults with DC admitted July 2019 to December 2020 were enrolled and randomized into the intervention(INT) or standard of care(SOC) arms. Weekly phone calls for a month were completed. In the INT arm, case managers ensured outpatient follow-up, paracentesis, and medication compliance. Thirty-day readmission rates and reasons were compared.RESULTS Calculated sample size was not achieved due to coronavirus disease 2019;240 patients were randomized into INT and SOC arms. 30-d readmission rate was 33.75%, 35.83% in the INT vs 31.67% in the SOC arm(P = 0.59). The top reason for 30-d readmission was hepatic encephalopathy(HE, 32.10%). There was a lower rate of 30-d readmissions for HE in the INT(21%) vs SOC arm(45%, P = 0.03). There were fewer 30-d readmissions in patients who attended early outpatient follow-up(n = 17, 23.61% vs n = 55, 76.39%, P = 0.04).CONCLUSION Our 30-d readmission rate was higher than the national rate but reduced by interventions in patients with DC with HE and early outpatient follow-up. Development of interventions to reduce early readmission in patients with DC is needed.展开更多
Nonalcoholic fatty liver disease (NAFLD) is a global epidemic that is likely to become the most common cause of chronic liver disease in the next decade, worldwide. Though numerous drugs have been evaluated in clinica...Nonalcoholic fatty liver disease (NAFLD) is a global epidemic that is likely to become the most common cause of chronic liver disease in the next decade, worldwide. Though numerous drugs have been evaluated in clinical trials, most of them have returned inconclusive results and shown poorly-tolerated adverse effects. None of the drugs have been approved by the Food and Drug Administration for treating biopsy-proven non-alcoholic steatohepatitis (NASH). Vitamin E and pioglitazone have been extensively used in treatment of biopsy-proven nondiabetic NASH patients. Although some amelioration of inflammation has been seen, these drugs did not improve the fibrosis component of NASH. Therefore, dietary modification and weight reduction have remained the cornerstone of treatment of NASH;moreover, they have shown to improve histological activity as well as fibrosis. The search for an ideal drug or ‘Holy Grail’ within this landscape of possible agents continues, as weight reduction is achieved only in less than 10% of patients. In this current review, we summarize the drugs for NASH which are under investigation, and we provide a critical analysis of their up-to-date results and outcomes.展开更多
Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world.Helicobacter pylori(H.pylori)infection associated duodenal ulcers should undergo eradication therapy.There are m...Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world.Helicobacter pylori(H.pylori)infection associated duodenal ulcers should undergo eradication therapy.There are many regimens offered for H.pylori eradication which include triple,quadruple,or sequential therapy regimens.The central aim of this systematic review is to evaluate the evidence for H.pylori therapy from a meta-analytical outlook.The consequence of the dose,type of proton-pump inhibitor,and the length of the treatment will be debated.The most important risk factor for eradication failure is resistance to clarithromycin and metronidazole.展开更多
This paper analyses the performance of a multiple gain boost converter(MGBC)connected to a solar photovoltaic(SPV)system with a grid-tied inverter.The capacitor inductor capacitor(CLC)-based MGBC is integrated to lift...This paper analyses the performance of a multiple gain boost converter(MGBC)connected to a solar photovoltaic(SPV)system with a grid-tied inverter.The capacitor inductor capacitor(CLC)-based MGBC is integrated to lift the output voltage of the SPV to the required level.The voltage lifts/levels in a boost converter(BC)are based on the number of CLC cells.The suggested MGBC is compared with various conventional BCs in terms of boost factor and component count.A hybrid fuzzy logic-perturb&observe maximum power point tracker(HFL-P&O MPPT)developed is used to monitor P_(max)(maximum power)generated by the SPV.Also,a comparative analysis of the suggested MPPT with a conventional P&O and fuzzy logic-based(FLB)MPPT for a CLC-based MGBC is presented.The comparison is made in terms of rise time,voltage ripples(%),steady-state time and boost factor.The output characteristics of the developed model for different irradiation conditions are analysed using the MATLAB/Simulink tool.The MPPT simulation result exhibits minimum oscillations at MPP and a significantly better rise time of 0.015 s when compared with a conventional MPPT and FLB MPPT.The proposed CLC-MGBC gives an appreciable boost factor of 4.The generated SPV power is supplied to the grid through a conventional inverter and synchronized using a phase-locked loop system.The total harmonic distortion of 1.66%obtained in the output current of the inverter is within the permissible range of the IEEE standards.展开更多
The present research deals with development and characterisation of magnesium–SiC–Gr hybrid composites through powder metallurgy route.Morphology analysis of the magnesium and reinforcement powder particles has been...The present research deals with development and characterisation of magnesium–SiC–Gr hybrid composites through powder metallurgy route.Morphology analysis of the magnesium and reinforcement powder particles has been carried out using particle size analyser(PSA)and X-ray diffraction(XRD),and then the mixed powders were analysed through scanning electron microscope(SEM).The developed composite exhibit increased hardness when compared to base material,which could be attributed to the presence of hard SiC.Furthermore,a slight decrease in hardness is observed for the hybrid composite when compared to Mg–SiC composite due to the presence of soft Gr particles.The tribological properties of the developed composite materials were investigated using pin-on-disc wear test apparatus under dry sliding conditions.The wear resistance of the developed composites improved significantly than that of the magnesium matrix due to the upright effect offered by both of the reinforcements.The SEM analysis was carried out on the worn out surfaces for better understanding of wear mechanisms.5%Gr reinforced Mg-10SiC composites confer better wear resistance among the developed composites.展开更多
Genetics plays an important role in determining the susceptibility of an individual to develop a disease. Complex, multi factorial diseases of modern day(diabetes, cardiovascular disease, hypertension and obesity) are...Genetics plays an important role in determining the susceptibility of an individual to develop a disease. Complex, multi factorial diseases of modern day(diabetes, cardiovascular disease, hypertension and obesity) are a result of disparity between the type of food consumed and genes, suggesting that food which does not match the host genes is probably one of the major reasons for developing life style diseases. Non-alcoholic fatty liver is becoming a global epidemic leading to substantial morbidity. While various genotyping approaches such as whole exome sequencing using next generation sequencers and genome wide association studies have identified susceptibility loci for non-alcoholic fatty liver disease(NAFLD) including variants in patatin-like phospholipase domain containing 3 and transmembrane 6 superfamily member 2 genes apart from others; nutrient based studies emphasized on a combination of vitamin D, E and omega-3 fatty acids to manage fatty liver disease. However majority of the studies were conducted independent of each other and very few studies explored the interactions between the genetic susceptibility and nutrient interactions. Identifying such interactions will aid in optimizing the nutrition tailor made to an individual's genetic makeup, thereby aiding in delaying the onset of the disease and its progression. The present topic focuses on studies that identified the genetic susceptibility for NAFLD, nutritional recommendations, and their interactions for better management of NAFLD.展开更多
Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced unive...Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.展开更多
The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the...The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the release of the high yielding varieties and advanced cane production technology. The physiological factors associated with ratooning performance and the variation in growth and yield were studied in 11 sugarcane varieties in two cycles of one plant and two ratoon crops each. The first ratoon and second ratoon crop showed 17.0% and 28.1% reduction in tiller production and 15.5% and 15.7% reduction in NMC, respectively, over plant crop. The differences in growth parameters between the plant and ratoon crops at the formative phase were lesser than that of grand growth and maturity phases. Varieties Co 86032, Co 97008, Co 95020 Co 99004 and Co 2000-10 showed better physiological efficiency in terms of plant height, shoot population, leaf size, TDMP, partitioning efficiency, chlorophyll content and nitrate reductase activity and significantly higher yield components such as NMC, SCW, cane length, internodal length as well as cane yield compared to other varieties. The higher reduction in ratoon yield in Co 99008, Co 94012, Co 8021 and Co 97009 (>35.00% reduction) was due to higher reduction in tiller production associated with stunted plant growth and root system, reducetion in individual leaf size and LAI, TDMP, total chlorophyll content, NMC, internodal length and SCW. The results obtained indicated that the plant height, TDMP, stem partitioning, leaf size, total chlorophyll content, SCW, cane length and cane girth were highly associated with yield of first and second ratoon crops than that of plant crop. Therefore the difference in the association between physiological parameters with yield of plant and ratoon crops therefore decides the ratooning potential of the crop.展开更多
This paper describes the combustion synthesis ofα-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes.The combustion derivedα-Fe_2O_3 na...This paper describes the combustion synthesis ofα-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes.The combustion derivedα-Fe_2O_3 nanopowder was characterized by powder X-ray diffraction（PXRD）,Braunauer,Emmett and Teller（BET） surface area,scanning electron microscopy（SEM） and Fourier transform infrared spectroscopy（FTIR）.Highly efficient,three-component condensation of aromatic aldehyde,malanonitrile and 4- hydroxycoumarin catalyzed byα-Fe2O3 nanoparticles at room temperature is described.The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes.The reactions are rapid,clean,and the products with good yield and high purity.展开更多
In this paper,the performance of a permanent magnet synchronous generator(PMSG)-based wind energy conversion system(WECS)supplied to an uncontrolled rectifier-fed boost converter(BC)interfaced with a three-phase T-typ...In this paper,the performance of a permanent magnet synchronous generator(PMSG)-based wind energy conversion system(WECS)supplied to an uncontrolled rectifier-fed boost converter(BC)interfaced with a three-phase T-type three-level inverter(TLI)has been analysed.The proposed WECS involves three converters,namely an uncontrolled rectifier that is used for conversion from AC to DC;a BC supplied by a PMSG-fed rectifier used to enhance the voltage gain;and a grid-connected three-phase T-type TLI is proposed to eliminate power-quality issues with synchronization of grid voltage and current.The main goal of this research is to model and control the grid-connected T-type TLI using a d-q synchronous frame for wind energy for regulating the DC-link voltage and transferring the generated wind power from the BC to the grid.Furthermore,the perturb&observe(P&O)-based maximum power point(MPP)approach is recommended to keep track of the MPP for a BC that is supplied from a PMSG-based WECS under constant and variable wind speeds.The proposed PMSG-based WECS interfaced with grid-connected T-type TLI using d-q control has been computationally modelled,simulated and validated with constant and variable speeds using MATLAB®and Simulink®.It is confirmed that the P&O-based MPP approach ensures maximum power for varying wind speeds,and the total harmonic distortion of the T-type TLI grid current value is 3.18%,which is within IEEE-519 limits.Furthermore,with grid synchronization,the power factor of the T-type TLI is maintained at unity to avoid power-quality issues.展开更多
This paper presents a solar-powered interleaved high-gain boost converter(IHGBC)that increases voltage gain with fewer ripples in the output voltage in comparison to existing DC-DC converters.The goal of this research...This paper presents a solar-powered interleaved high-gain boost converter(IHGBC)that increases voltage gain with fewer ripples in the output voltage in comparison to existing DC-DC converters.The goal of this research is to develop a hybrid-based maximum power point tracking(MPPT)approach with the combination of a flower pollination(FP)algorithm assisted with a perturb&observe(P&O)MPPT approach for solar photovoltaic(SPV)systems integrated with IHGBC.To ensure effective usage of both FP and P&O algorithms,this study incorporates and validates the hybrid-based MPPT approach.The proposed solar-powered IHGBC with a hybrid-based MPPT algorithm has been computationally modelled and simulated using MATLAB®and Simulink®for both uniform and non-uniform irradiation and analysed for voltage gain,ripples in the output waveforms and convergence time.The proposed hybrid-based MPPT is based on a number of flowers that forecast the initial global peak,assisted by P&O in the last stage for faster convergence to attain the maximum power point(MPP).As a result,the hybrid-based MPPT approach alleviates the computational issues encountered in P&O and FP-based MPP approaches.The proposed hybrid MPPT is compared with conventional MPPT for SPV and the results show that the solar-powered IHGBC using a hybrid-based MPPT technique has negligible oscillations of 0.14%with a high-voltage gain of 7.992 and a fast convergence rate of 0.05 seconds compared to individual P&O-based MPPT and FP-based MPPT techniques.The simulation results of the proposed MPPT with IHGBC outperform the conventional MPPT with high-gain converters.展开更多
Data security plays a vital role in the current scenario due to the advanced and sophisticated data access techniques. Present development in data access is always a threat to data that are stored in electronic device...Data security plays a vital role in the current scenario due to the advanced and sophisticated data access techniques. Present development in data access is always a threat to data that are stored in electronic devices. Among all the forms of data, image is an important aspect that still needs methodologies to be stored securely. This work focuses on a novel technique to secure images using inter block difference and advanced encryption standard (AES). The AES algorithm is chosen for encryption since there is no prevalent attack that is successful in analyzing it. Instead of encrypting the entire image, only a part of the image is encrypted. The proposed work is found to reduce the encryption overhead in a significant way and at the same time preserves the safety of the image. It is also observed that the decryption is done in an efficient and time preserving manner.展开更多
In this paper,a multistring-multilevel inverter(M-MLI)for renewable-energy-source applications has been proposed with reduced switch count and harmonics along with single-switch fault analysis for various levels.It re...In this paper,a multistring-multilevel inverter(M-MLI)for renewable-energy-source applications has been proposed with reduced switch count and harmonics along with single-switch fault analysis for various levels.It requires only‘m+1’power switches for‘m’voltage levels.The proposed work achieves the fine-tuning of switching angles using a metaheuristic technique,i.e.the teaching-learning-based optimization algorithm(TLBOA),to mitigate the total harmonic distortion(THD)of the M-MLI.Furthermore,the proposed TLBOA has been compared with conventional modulation techniques such as equal phase(EP),half-equal phase(HEP),near-level control(NLC)and Newton-Raphson(NR)to verify the effectiveness of TLBOA for various voltage levels in terms of%voltage-THD(%V-THD),computational time and methodology.By fine-tuning the switching angles,the%V-THD is improved significantly when compared with EP,HEP,NLC and NR modulation techniques.For an 11-level single-phase M-MLI,the%V-THD using TLBOA at 0.91 modulation index(MI)is 5.051%.The lower-order harmonics,i.e.5,7,11 and 13,are eliminated to improve the power quality.Furthermore,MLIs are often prone to failure,resulting in waveform distortion.The extreme reduction in power quality impacts the load and significant damage is likely.The location of the open-circuit fault to be identified becomes more tedious under the faulty conditions with increased switch counts and voltage levels since the mathematical modelling fails to address the scenario in less computational time.Hence,the machine-learning approach,i.e.support vector machine(SVM)with Bayesian optimization,has been discussed to locate the faulty switch.Finally,the proposed M-MLI configuration has been modelled,simulated and validated using MATLAB®and Simulink®.The results of the M-MLI configuration have been verified for 7,9 and 11 levels using TLBOA along with fault analysis using the SVM approach.展开更多
Solar photovoltaic(SPV)modules have a low output voltage and are load-dependent.Therefore,it is critical that the SPV system has an adequate DC-DC converter to regulate and improve the output voltage to get maximum ou...Solar photovoltaic(SPV)modules have a low output voltage and are load-dependent.Therefore,it is critical that the SPV system has an adequate DC-DC converter to regulate and improve the output voltage to get maximum output voltage.To meet load requirements,the voltage must be increased,necessitating the use of energy-efficient power electronic converters.The performance of an SPV system coupled to a high-gain quadratic boost converter(HG-QBC)with a load is investigated in this paper.The suggested HG-QBC for the SPV system at a lower value of duty ratio provides high voltage gain with a boost factor of four times.An analytical comparison is carried out with the various existing boost converters in terms of the components and the boost factor.The issue of locating the maximum power generation point from the SPV system is crucial.As a result,choosing an appropriate maximum power point tracker(MPPT)-based technique to obtain the peak power output of the SPV system under the rapidly varying atmospheric conditions is vital.To determine the highest output power of an SPV system,a hybrid-based MPPT with a neural network assisted by a perturb and observe(P&O)technique is proposed.For the HG-QBC,a comparison of the proposed MPPT with a traditional P&O-based MPPT is illustrated.The comparative analysis takes into account rise time,settling time and voltage ripples.The output voltage and power characteristics of the proposed model are analysed under constant and varying irradiation conditions using MATLAB®/Simulink®.The results of a hybrid-based MPPT show that the oscillations are minimum at the maximum power point with fewer ripples of 0.20%and a settling time of 1.2 s in comparison with the other two techniques.展开更多
Favipiravir,an antiviral,was given restricted emergency use approval to treat coronavirus disease 2019(COVID-19)in many countries.While the clinical efficacy of favipiravir in COVID-19 remains uncertain,the approval w...Favipiravir,an antiviral,was given restricted emergency use approval to treat coronavirus disease 2019(COVID-19)in many countries.While the clinical efficacy of favipiravir in COVID-19 remains uncertain,the approval was based on findings from in vitro studies and a clinical trial.1 Limited data from studies of the Ebola virus and influenza disease showed a favorable safety profile.2 Herein,we provide the first report of drug-induced liver injury(DILI)due to favipiravir in patients treated for COVID-19.展开更多
基金Supported by the Spanish Ministry of Science and Innovation(MICINN,Spain),No.AGL2017-88801-P(to Sanz Y)the Miguel Server grant from the Spanish"Carlos III"Health Institute(ISCIII),No.CP19/00132(to Benitez-Paez A)+2 种基金The Norwegian Research Council(Funding Postdoc Position for Bharath Halandur Nagaraja),No.FRIMEDBIO276010and Helse Vest’s Research Funding,No.HV912243and ERC H2020-MSCA-IF-2019,No.895219(to Haleem N).
文摘Irritable bowel syndrome(IBS)is a common clinical label for medically unexplained gastrointestinal symptoms,recently described as a disturbance of the microbiota-gut-brain axis.Despite decades of research,the pathophysiology of this highly heterogeneous disorder remains elusive.However,a dramatic change in the understanding of the underlying pathophysiological mechanisms surfaced when the importance of gut microbiota protruded the scientific picture.Are we getting any closer to understanding IBS’etiology,or are we drowning in unspecific,conflicting data because we possess limited tools to unravel the cluster of secrets our gut microbiota is concealing?In this comprehensive review we are discussing some of the major important features of IBS and their interaction with gut microbiota,clinical microbiota-altering treatment such as the low FODMAP diet and fecal microbiota transplantation,neuroimaging and methods in microbiota analyses,and current and future challenges with big data analysis in IBS.
基金funded by the National Remote Sensing Centre,Hyderabad,India under NRSC-DOS-DBTGovt.of India project entitled‘‘Biodiversity Characterization in Southern parts of Karnataka’’(Project Number:UAS(B)/DR/GOI/245/2011-12)
文摘Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4–8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.
基金Supported by Grants from Asian Healthcare Foundation
文摘AIM: To study the effect of mobilized peripheral blood autologous CD34 positive(CD34+) cell infusion in patients with non-viral decompensated cirrhosis.METHODS: Cirrhotic patients of non-viral etiology were divided into 2 groups based on their willingness to be listed for deceased donor liver transplant(DDLT)(control, n = 23) or to receive autologous CD34+ cell infusion through the hepatic artery(study group, n= 22). Patients in the study group were admitted to hospital and received granulocyte colony stimulating factor injections 520 μg/d for 3 consecutive days to mobilize CD34+ cells from the bone marrow. On day 4,leukapheresis was done and CD34+ cells were isolated using CliniMAC magnetic cell sorter. The isolated CD34+ cells were infused into the hepatic artery under radiological guidance. The patients were discharged within 48 h. The control group received standard of care treatment for liver cirrhosis and were worked up for DDLT as per protocol of the institute. Both groups were followed up every week for 4 wk and then every month for 3 mo.RESULTS: In the control and the study group, the cause of cirrhosis was cryptogenic in 18(78.2%) and16(72.72%) and alcohol related in 5(21.7%) and6(27.27%), respectively. The mean day 3 cell count(cells/μL) was 27.00 ± 20.43 with a viability of 81.84± 11.99%. and purity of 80%-90%. Primary end point analysis revealed that at 4 wk, the mean serum albumin in the study group increased significantly(2.83± 0.36 vs 2.43 ± 0.42, P = 0.001) when compared with controls. This improvement in albumin was,however, not sustained at 3 mo. However, at the end of3 mo there was a statistically significant improvement in serum creatinine in the study group(0.96 ± 0.33 vs 1.42 ± 0.70, P = 0.01) which translated into a significant improvement in the Model for End-Stage Liver Disease score(15.75 ± 5.13 vs 19.94 ± 6.68,P = 0.04). On statistical analysis of secondary end points, the transplant free survival at the end of 1 mo and 3 mo did not show any significant difference(P =0.60) wh
文摘AIM: To investigate genetic susceptibility in Indian subjects with non-alcoholic fatty liver disease(NAFLD) by performing a pooled genetic study.METHODS: Study subjects(n = 306) were recruited and categorized into NAFLD and control groups based on ultrasound findings of fatty infiltration. Of the 306 individuals, 156 individuals had fatty infiltration and thus comprised the NAFLD group. One hundred and fifty(n = 150) individuals were normal, without fatty infiltration of the liver, comprising the control group. Blood samples, demographic and anthropometric data from the individuals were collected after obtaining informed consent. Anthropometric data, blood glucose, lipids and liver function tests were estimated using standard methods. Genome wide association stud-ies done to date on NAFLD were identified, 19 single nucleotide polymorphisms(SNPs) were selected from these studies that were reported to be significantly associated with NAFLD and genotyping was performed on the Sequenom platform. Student's t test for continuous variables and χ2 test was applied to variant carriers from both groups. Required corrections were applied as multiple testing was done.RESULTS The mean age of the control group was 39.78 ± 10.83 and the NAFLD group was 36.63 ± 8.20 years. The waist circumference of males and females in the control and NAFLD groups were 80.13 ± 10.35; 81.77 ± 13.65 and 94.09 ± 10.53; 92.53 ± 8.27 respectively. The mean triglyceride and alanine transaminase(ALT) levels in the control and NAFLD groups were 135.18 ± 7.77; 25.39 ± 14.73 and 184.40 ± 84.31; 110.20 ± 67.05 respectively. When χ2 test was applied to the number of individuals carrying the variant risk alleles between the control and NAFLD group, a significant association was seen between rs738409 of the patatin-like phospholipase domain containing 3(PNPLA3) gene(P = 0.001), rs2073080 of the PARVB gene(P = 0.02), rs2143571 of SAMM50 gene(P = 0.05) and rs6487679 of the pregnancy zone protein(PZP) gene(P = 0.01) with the disease. Variant single
文摘A set of borophosphate glasses doped with alkali and transition metal (TM) ions have been synthesized. The glasses were carried through;annealing, XRD, density, DC conductivity studies. Molar volume and density varied nonlinearly. High temperature activation energy is analysed taking into consideration of Mott’s SPH model. The low temperature electrical conductivity was analysed by Mott and Greaves VRH. Several polaron hopping related parameters at high temperature region and density of states at low temperature region were computed. The high temperature DC activation energy measured by conductivity, calculated numerous pertained parameters varied nonlinearly with mole fraction of vanadium content. The Study exhibits DC electrical conduction is due to both alkali and transition metal ions and thus confirms the mixed conductivity. A crossover conduction mechanism from the ionic dominant region to polaronic predominant region has been also observed. Studies revealed the single transition effect at 0.4 mol fraction of V<sub>2</sub>O<sub>5</sub> content.
基金GASTR29:Prospective validation of readmission risk score and interventions to prevent readmission in patients with decompensated cirrhosis(CCTS ID#:6018).
文摘BACKGROUND We previously reported national 30-d readmission rates of 27% in patients with decompensated cirrhosis(DC).AIM To study prospective interventions to reduce early readmissions in DC at our tertiary center.METHODS Adults with DC admitted July 2019 to December 2020 were enrolled and randomized into the intervention(INT) or standard of care(SOC) arms. Weekly phone calls for a month were completed. In the INT arm, case managers ensured outpatient follow-up, paracentesis, and medication compliance. Thirty-day readmission rates and reasons were compared.RESULTS Calculated sample size was not achieved due to coronavirus disease 2019;240 patients were randomized into INT and SOC arms. 30-d readmission rate was 33.75%, 35.83% in the INT vs 31.67% in the SOC arm(P = 0.59). The top reason for 30-d readmission was hepatic encephalopathy(HE, 32.10%). There was a lower rate of 30-d readmissions for HE in the INT(21%) vs SOC arm(45%, P = 0.03). There were fewer 30-d readmissions in patients who attended early outpatient follow-up(n = 17, 23.61% vs n = 55, 76.39%, P = 0.04).CONCLUSION Our 30-d readmission rate was higher than the national rate but reduced by interventions in patients with DC with HE and early outpatient follow-up. Development of interventions to reduce early readmission in patients with DC is needed.
文摘Nonalcoholic fatty liver disease (NAFLD) is a global epidemic that is likely to become the most common cause of chronic liver disease in the next decade, worldwide. Though numerous drugs have been evaluated in clinical trials, most of them have returned inconclusive results and shown poorly-tolerated adverse effects. None of the drugs have been approved by the Food and Drug Administration for treating biopsy-proven non-alcoholic steatohepatitis (NASH). Vitamin E and pioglitazone have been extensively used in treatment of biopsy-proven nondiabetic NASH patients. Although some amelioration of inflammation has been seen, these drugs did not improve the fibrosis component of NASH. Therefore, dietary modification and weight reduction have remained the cornerstone of treatment of NASH;moreover, they have shown to improve histological activity as well as fibrosis. The search for an ideal drug or ‘Holy Grail’ within this landscape of possible agents continues, as weight reduction is achieved only in less than 10% of patients. In this current review, we summarize the drugs for NASH which are under investigation, and we provide a critical analysis of their up-to-date results and outcomes.
文摘Peptic ulcer disease continues to be issue especially due to its high prevalence in the developing world.Helicobacter pylori(H.pylori)infection associated duodenal ulcers should undergo eradication therapy.There are many regimens offered for H.pylori eradication which include triple,quadruple,or sequential therapy regimens.The central aim of this systematic review is to evaluate the evidence for H.pylori therapy from a meta-analytical outlook.The consequence of the dose,type of proton-pump inhibitor,and the length of the treatment will be debated.The most important risk factor for eradication failure is resistance to clarithromycin and metronidazole.
文摘This paper analyses the performance of a multiple gain boost converter(MGBC)connected to a solar photovoltaic(SPV)system with a grid-tied inverter.The capacitor inductor capacitor(CLC)-based MGBC is integrated to lift the output voltage of the SPV to the required level.The voltage lifts/levels in a boost converter(BC)are based on the number of CLC cells.The suggested MGBC is compared with various conventional BCs in terms of boost factor and component count.A hybrid fuzzy logic-perturb&observe maximum power point tracker(HFL-P&O MPPT)developed is used to monitor P_(max)(maximum power)generated by the SPV.Also,a comparative analysis of the suggested MPPT with a conventional P&O and fuzzy logic-based(FLB)MPPT for a CLC-based MGBC is presented.The comparison is made in terms of rise time,voltage ripples(%),steady-state time and boost factor.The output characteristics of the developed model for different irradiation conditions are analysed using the MATLAB/Simulink tool.The MPPT simulation result exhibits minimum oscillations at MPP and a significantly better rise time of 0.015 s when compared with a conventional MPPT and FLB MPPT.The proposed CLC-MGBC gives an appreciable boost factor of 4.The generated SPV power is supplied to the grid through a conventional inverter and synchronized using a phase-locked loop system.The total harmonic distortion of 1.66%obtained in the output current of the inverter is within the permissible range of the IEEE standards.
文摘The present research deals with development and characterisation of magnesium–SiC–Gr hybrid composites through powder metallurgy route.Morphology analysis of the magnesium and reinforcement powder particles has been carried out using particle size analyser(PSA)and X-ray diffraction(XRD),and then the mixed powders were analysed through scanning electron microscope(SEM).The developed composite exhibit increased hardness when compared to base material,which could be attributed to the presence of hard SiC.Furthermore,a slight decrease in hardness is observed for the hybrid composite when compared to Mg–SiC composite due to the presence of soft Gr particles.The tribological properties of the developed composite materials were investigated using pin-on-disc wear test apparatus under dry sliding conditions.The wear resistance of the developed composites improved significantly than that of the magnesium matrix due to the upright effect offered by both of the reinforcements.The SEM analysis was carried out on the worn out surfaces for better understanding of wear mechanisms.5%Gr reinforced Mg-10SiC composites confer better wear resistance among the developed composites.
文摘Genetics plays an important role in determining the susceptibility of an individual to develop a disease. Complex, multi factorial diseases of modern day(diabetes, cardiovascular disease, hypertension and obesity) are a result of disparity between the type of food consumed and genes, suggesting that food which does not match the host genes is probably one of the major reasons for developing life style diseases. Non-alcoholic fatty liver is becoming a global epidemic leading to substantial morbidity. While various genotyping approaches such as whole exome sequencing using next generation sequencers and genome wide association studies have identified susceptibility loci for non-alcoholic fatty liver disease(NAFLD) including variants in patatin-like phospholipase domain containing 3 and transmembrane 6 superfamily member 2 genes apart from others; nutrient based studies emphasized on a combination of vitamin D, E and omega-3 fatty acids to manage fatty liver disease. However majority of the studies were conducted independent of each other and very few studies explored the interactions between the genetic susceptibility and nutrient interactions. Identifying such interactions will aid in optimizing the nutrition tailor made to an individual's genetic makeup, thereby aiding in delaying the onset of the disease and its progression. The present topic focuses on studies that identified the genetic susceptibility for NAFLD, nutritional recommendations, and their interactions for better management of NAFLD.
文摘Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.
文摘The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the release of the high yielding varieties and advanced cane production technology. The physiological factors associated with ratooning performance and the variation in growth and yield were studied in 11 sugarcane varieties in two cycles of one plant and two ratoon crops each. The first ratoon and second ratoon crop showed 17.0% and 28.1% reduction in tiller production and 15.5% and 15.7% reduction in NMC, respectively, over plant crop. The differences in growth parameters between the plant and ratoon crops at the formative phase were lesser than that of grand growth and maturity phases. Varieties Co 86032, Co 97008, Co 95020 Co 99004 and Co 2000-10 showed better physiological efficiency in terms of plant height, shoot population, leaf size, TDMP, partitioning efficiency, chlorophyll content and nitrate reductase activity and significantly higher yield components such as NMC, SCW, cane length, internodal length as well as cane yield compared to other varieties. The higher reduction in ratoon yield in Co 99008, Co 94012, Co 8021 and Co 97009 (>35.00% reduction) was due to higher reduction in tiller production associated with stunted plant growth and root system, reducetion in individual leaf size and LAI, TDMP, total chlorophyll content, NMC, internodal length and SCW. The results obtained indicated that the plant height, TDMP, stem partitioning, leaf size, total chlorophyll content, SCW, cane length and cane girth were highly associated with yield of first and second ratoon crops than that of plant crop. Therefore the difference in the association between physiological parameters with yield of plant and ratoon crops therefore decides the ratooning potential of the crop.
基金VTU(VTU/Aca./2009-10/A-9/11714) for the financial support and Chemistry-TEQIP Laboratory of MSRIT and SSMRV College, Chemistry Research Center
文摘This paper describes the combustion synthesis ofα-Fe2O3 nanopowder at much lower temperature and its catalytic activity for the one-pot preparation of 3,4-dihydropyrano[c]chromenes.The combustion derivedα-Fe_2O_3 nanopowder was characterized by powder X-ray diffraction（PXRD）,Braunauer,Emmett and Teller（BET） surface area,scanning electron microscopy（SEM） and Fourier transform infrared spectroscopy（FTIR）.Highly efficient,three-component condensation of aromatic aldehyde,malanonitrile and 4- hydroxycoumarin catalyzed byα-Fe2O3 nanoparticles at room temperature is described.The method offers an excellent alternative to the synthesis of 3,4-dihydropyrano[c]chromenes.The reactions are rapid,clean,and the products with good yield and high purity.
文摘In this paper,the performance of a permanent magnet synchronous generator(PMSG)-based wind energy conversion system(WECS)supplied to an uncontrolled rectifier-fed boost converter(BC)interfaced with a three-phase T-type three-level inverter(TLI)has been analysed.The proposed WECS involves three converters,namely an uncontrolled rectifier that is used for conversion from AC to DC;a BC supplied by a PMSG-fed rectifier used to enhance the voltage gain;and a grid-connected three-phase T-type TLI is proposed to eliminate power-quality issues with synchronization of grid voltage and current.The main goal of this research is to model and control the grid-connected T-type TLI using a d-q synchronous frame for wind energy for regulating the DC-link voltage and transferring the generated wind power from the BC to the grid.Furthermore,the perturb&observe(P&O)-based maximum power point(MPP)approach is recommended to keep track of the MPP for a BC that is supplied from a PMSG-based WECS under constant and variable wind speeds.The proposed PMSG-based WECS interfaced with grid-connected T-type TLI using d-q control has been computationally modelled,simulated and validated with constant and variable speeds using MATLAB®and Simulink®.It is confirmed that the P&O-based MPP approach ensures maximum power for varying wind speeds,and the total harmonic distortion of the T-type TLI grid current value is 3.18%,which is within IEEE-519 limits.Furthermore,with grid synchronization,the power factor of the T-type TLI is maintained at unity to avoid power-quality issues.
文摘This paper presents a solar-powered interleaved high-gain boost converter(IHGBC)that increases voltage gain with fewer ripples in the output voltage in comparison to existing DC-DC converters.The goal of this research is to develop a hybrid-based maximum power point tracking(MPPT)approach with the combination of a flower pollination(FP)algorithm assisted with a perturb&observe(P&O)MPPT approach for solar photovoltaic(SPV)systems integrated with IHGBC.To ensure effective usage of both FP and P&O algorithms,this study incorporates and validates the hybrid-based MPPT approach.The proposed solar-powered IHGBC with a hybrid-based MPPT algorithm has been computationally modelled and simulated using MATLAB®and Simulink®for both uniform and non-uniform irradiation and analysed for voltage gain,ripples in the output waveforms and convergence time.The proposed hybrid-based MPPT is based on a number of flowers that forecast the initial global peak,assisted by P&O in the last stage for faster convergence to attain the maximum power point(MPP).As a result,the hybrid-based MPPT approach alleviates the computational issues encountered in P&O and FP-based MPP approaches.The proposed hybrid MPPT is compared with conventional MPPT for SPV and the results show that the solar-powered IHGBC using a hybrid-based MPPT technique has negligible oscillations of 0.14%with a high-voltage gain of 7.992 and a fast convergence rate of 0.05 seconds compared to individual P&O-based MPPT and FP-based MPPT techniques.The simulation results of the proposed MPPT with IHGBC outperform the conventional MPPT with high-gain converters.
文摘Data security plays a vital role in the current scenario due to the advanced and sophisticated data access techniques. Present development in data access is always a threat to data that are stored in electronic devices. Among all the forms of data, image is an important aspect that still needs methodologies to be stored securely. This work focuses on a novel technique to secure images using inter block difference and advanced encryption standard (AES). The AES algorithm is chosen for encryption since there is no prevalent attack that is successful in analyzing it. Instead of encrypting the entire image, only a part of the image is encrypted. The proposed work is found to reduce the encryption overhead in a significant way and at the same time preserves the safety of the image. It is also observed that the decryption is done in an efficient and time preserving manner.
文摘In this paper,a multistring-multilevel inverter(M-MLI)for renewable-energy-source applications has been proposed with reduced switch count and harmonics along with single-switch fault analysis for various levels.It requires only‘m+1’power switches for‘m’voltage levels.The proposed work achieves the fine-tuning of switching angles using a metaheuristic technique,i.e.the teaching-learning-based optimization algorithm(TLBOA),to mitigate the total harmonic distortion(THD)of the M-MLI.Furthermore,the proposed TLBOA has been compared with conventional modulation techniques such as equal phase(EP),half-equal phase(HEP),near-level control(NLC)and Newton-Raphson(NR)to verify the effectiveness of TLBOA for various voltage levels in terms of%voltage-THD(%V-THD),computational time and methodology.By fine-tuning the switching angles,the%V-THD is improved significantly when compared with EP,HEP,NLC and NR modulation techniques.For an 11-level single-phase M-MLI,the%V-THD using TLBOA at 0.91 modulation index(MI)is 5.051%.The lower-order harmonics,i.e.5,7,11 and 13,are eliminated to improve the power quality.Furthermore,MLIs are often prone to failure,resulting in waveform distortion.The extreme reduction in power quality impacts the load and significant damage is likely.The location of the open-circuit fault to be identified becomes more tedious under the faulty conditions with increased switch counts and voltage levels since the mathematical modelling fails to address the scenario in less computational time.Hence,the machine-learning approach,i.e.support vector machine(SVM)with Bayesian optimization,has been discussed to locate the faulty switch.Finally,the proposed M-MLI configuration has been modelled,simulated and validated using MATLAB®and Simulink®.The results of the M-MLI configuration have been verified for 7,9 and 11 levels using TLBOA along with fault analysis using the SVM approach.
文摘Solar photovoltaic(SPV)modules have a low output voltage and are load-dependent.Therefore,it is critical that the SPV system has an adequate DC-DC converter to regulate and improve the output voltage to get maximum output voltage.To meet load requirements,the voltage must be increased,necessitating the use of energy-efficient power electronic converters.The performance of an SPV system coupled to a high-gain quadratic boost converter(HG-QBC)with a load is investigated in this paper.The suggested HG-QBC for the SPV system at a lower value of duty ratio provides high voltage gain with a boost factor of four times.An analytical comparison is carried out with the various existing boost converters in terms of the components and the boost factor.The issue of locating the maximum power generation point from the SPV system is crucial.As a result,choosing an appropriate maximum power point tracker(MPPT)-based technique to obtain the peak power output of the SPV system under the rapidly varying atmospheric conditions is vital.To determine the highest output power of an SPV system,a hybrid-based MPPT with a neural network assisted by a perturb and observe(P&O)technique is proposed.For the HG-QBC,a comparison of the proposed MPPT with a traditional P&O-based MPPT is illustrated.The comparative analysis takes into account rise time,settling time and voltage ripples.The output voltage and power characteristics of the proposed model are analysed under constant and varying irradiation conditions using MATLAB®/Simulink®.The results of a hybrid-based MPPT show that the oscillations are minimum at the maximum power point with fewer ripples of 0.20%and a settling time of 1.2 s in comparison with the other two techniques.
文摘Favipiravir,an antiviral,was given restricted emergency use approval to treat coronavirus disease 2019(COVID-19)in many countries.While the clinical efficacy of favipiravir in COVID-19 remains uncertain,the approval was based on findings from in vitro studies and a clinical trial.1 Limited data from studies of the Ebola virus and influenza disease showed a favorable safety profile.2 Herein,we provide the first report of drug-induced liver injury(DILI)due to favipiravir in patients treated for COVID-19.
