Preoperative albumin-bilirubin score and liver resection percentage determine postoperative liver regeneration after partial hepatectomy

BACKGROUND The success of liver resection relies on the ability of the remnant liver to regenerate.Most of the knowledge regarding the pathophysiological basis of liver regeneration comes from rodent studies,and data on humans are scarce.Additionally,there is limited knowledge about the preoperative factors that influence postoperative regeneration.AIM To quantify postoperative remnant liver volume by the latest volumetric software and investigate perioperative factors that affect posthepatectomy liver regenera-tion.METHODS A total of 268 patients who received partial hepatectomy were enrolled.Patients were grouped into right hepatectomy/trisegmentectomy(RH/Tri),left hepa-tectomy(LH),segmentectomy(Seg),and subsegmentectomy/nonanatomical hepatectomy(Sub/Non)groups.The regeneration index(RI)and late rege-neration rate were defined as(postoperative liver volume)/[total functional liver volume(TFLV)]×100 and(RI at 6-months-RI at 3-months)/RI at 6-months,respectively.The lower 25th percentile of RI and the higher 25th percentile of late regeneration rate in each group were defined as“low regeneration”and“delayed regeneration”.“Restoration to the original size”was defined as regeneration of the liver volume by more than 90%of the TFLV at 12 months postsurgery.RESULTS The numbers of patients in the RH/Tri,LH,Seg,and Sub/Non groups were 41,53,99 and 75,respectively.The RI plateaued at 3 months in the LH,Seg,and Sub/Non groups,whereas the RI increased until 12 months in the RH/Tri group.According to our multivariate analysis,the preoperative albumin-bilirubin(ALBI)score was an independent factor for low regeneration at 3 months[odds ratio(OR)95%CI=2.80(1.17-6.69),P=0.02;per 1.0 up]and 12 months[OR=2.27(1.01-5.09),P=0.04;per 1.0 up].Multivariate analysis revealed that only liver resection percentage[OR=1.03(1.00-1.05),P=0.04]was associated with delayed regeneration.Furthermore,multivariate analysis demonstrated that the preoperative ALBI score[OR=2.63(1.00-1.05),P=0.02;per 1.0 up]and liver resection percentage[OR=1.02(1.00-1.05),P=0.04;per 1.0 up]were found to be independent risk factors associated with volume restoration failure.CONCLUSION Liver regeneration posthepatectomy was determined by the resection percentage and preoperative ALBI score.This knowledge helps surgeons decide the timing and type of rehepatectomy for recurrent cases.

Experimental Study on the Performance of ORC System Based on Ultra-Low Temperature Heat Sources

This paper discussed the experimental results of the performance of an organic Rankine cycle(ORC)system with an ultra-low temperature heat source.The low boiling point working medium R134a was adopted in the system.The simulated heat source temperature(SHST)in this work was set from 39.51°C to 48.60°C by the simulated heat source module.The influence of load percentage of simulated heat source(LPSHS)between 50%and 70%,the rotary valve opening(RVO)between 20%and 100%,the resistive load between 36Ωand 180Ωor the no-load of the generator,as well as the autumn and winter ambient temperature on the system performance were studied.The results showed that the stability of the system was promoted when the generator had a resistive load.The power generation(PG)and generator speed(GS)of the system in autumn were better than in winter,but the expander pressure ratio(EPR)was lower than in winter.Keep RVO unchanged,the SHST,the mass flow rate(MFR)of the working medium,GS,and the PG of the system increased with the increasing of LPSHS for different generator resistance load values.When the RVO was 60%,LPSHS was 70%,the SHST was 44.15°C and the resistive load was 72Ω,the highest PG reached 15.11 W.Finally,a simulation formula was obtained for LPSHS,resistance load,and PG,and its correlation coefficient was between 0.9818 and 0.9901.The formula can accurately predict the PG.The experimental results showed that the standard deviation between the experimental and simulated values was below 0.0792,and the relative error was within±5%.

High Dimension Multivariate Data Analysis for Small Group Samples of Chemical Volatile Profiles of African Nightshade Species

Quantitative headspace analysis of volatiles emitted by plants or any other living organisms in chemical ecology studies generates large multidimensional data that require extensive mining and refining to extract useful information. More often the number of variables and the quantified volatile compounds exceed the number of observations or samples and hence many traditional statistical analysis methods become inefficient. Here, we employed machine learning algorithm, random forest (RF) in combination with distance-based procedure, similarity percentage (SIMPER) as preprocessing steps to reduce the data dimensionality in the chemical profiles of volatiles from three African nightshade plant species before subjecting the data to non-metric multidimensional scaling (NMDS). In addition, non-parametric methods namely permutational multivariate analysis of variance (PERMANOVA) and analysis of similarities (ANOSIM) were applied to test hypothesis of differences among the African nightshade species based on the volatiles profiles and ascertain the patterns revealed by NMDS plots. Our results revealed that there were significant differences among the African nightshade species when the data’s dimension was reduced using RF variable importance and SIMPER, as also supported by NMDS plots that showed S. scabrum being separated from S. villosum and S. sarrachoides based on the reduced data variables. The novelty of our work is on the merits of using data reduction techniques to successfully reveal differences in groups which could have otherwise not been the case if the analysis were performed on the entire original data matrix characterized by small samples. The R code used in the analysis has been shared herein for interested researchers to customise it for their own data of similar nature.

Assessing the Relationship between October-November-December Rainfall and Indian Ocean Dipole in Recent Decades over Tanzania Following the 2011 Abrupt Change

The present study explored how the Indian Ocean Dipole (IOD) influences October-November-December (OND) rainfall over Tanzania in recent decade following the 2011 abrupt change. The study spans 50 years, from 1973 to 2022. Notable abrupt changes were observed in 1976 and 2011, leading us to divide our study into two periods: 1976-2010 and 2011-2022, allowing for a close investigation into the existing relationship between OND IOD and OND rainfall and their associated large-scale atmospheric circulations. It was found that the relationship between OND IOD and OND rainfall strengthened, with the correlation changed from +0.73 during 1976-2010 to +0.81 during 2011-2022. Further investigation revealed that, during 1976-2010, areas that received above- normal rainfall during positive IOD experienced below-normal during 2011- 2022 and vice versa. The same pattern relationship was observed for negative IOD. Spatial analysis demonstrates that the percentage departure of rainfall across the region mirrors the standardized rainfall anomalies. The study highlights that the changing relationship between OND IOD and OND rainfall corresponds to the east-west shift of Walker circulation, as well as the north-south shift of Hadley circulation. Analysis of sea surface temperature (SST) indicates that both positive and negative IOD events strengthened during 2011-2022 compared to 1976-2010. Close monitoring of this relationship across different timescales could be useful for updating OND rainfall seasonal forecasts in Tanzania, serving as a tool for reducing socio-economic impacts.

Epidemiology and outcome of individuals with intraductal papillary neoplasms of the bile duct

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)is a rare distinct subtype of precursor lesions of biliary carcinoma.IPNB is considered to originate from luminal biliary epithelial cells,typically displays mucin-hypersecretion or a papillary growth pattern,and results in cystic dilatation[1].IPNB develops anywhere in the intrahepatic and extrahepatic biliary tracts,and can occur in various pathological stages from low-grade dysplasia to invasive carcinoma.IPNBs have similar phenotypic changes in the occurrence and development of all subtypes,and the prognosis is significantly better than that of traditional(nonpapillary)cholangiocarcinoma.AIM To evaluate the clinicopathological features of IPNB to provide evidence-based guidance for treatment.METHODS Invasive IPNB,invasive intraductal papillary mucinous neoplasm of the pancreas(IPMN),and traditional cholangiocarcinoma data for affected individuals from 1975 to 2016 were obtained from the Surveillance,Epidemiology,and End Results(SEER)database.Annual percentage changes(APCs)in the incidence and incidence-based(IB)mortality were calculated.We identified the independent predictors of overall survival(OS)and cancer-specific survival(CSS)in indivi duals with invasive IPNB.RESULTS The incidence and IB mortality of invasive IPNB showed sustained decreases,with an APC of-4.5%(95%CI:-5.1%to-3.8%)and-3.3%(95%CI:-4.1%to-2.6%)(P<0.001),respectively.Similar decreases in incidence and IB mortality were seen for invasive IPMN but not for traditional cholangiocarcinoma.Both OS and CSS for invasive IPNB were better than for invasive IPMN and traditional cholangiocarcinoma.A total of 1635 individuals with invasive IPNB were included in our prognosis analysis.The most common tumor sites were the pancreaticobiliary ampulla(47.9%)and perihilar tract(36.7%),but the mucin-related subtype of invasive IPNB was the main type,intrahepatically(approximately 90%).In the univariate and multivariate Cox regression analysis,age,tumor site,grade and stage,subtype,surgery,and chemotherapy were associated with OS and CSS(P<0.05).CONCLUSION Incidence and IB mortality of invasive IPNB trended steadily downward.The heterogeneity of IPNB comprises site and the tumor’s mucin-producing status.

Environmental significance and hydrochemical characteristics of rivers in the western region of the Altay Mountains,China

Analysis of environmental significance and hydrochemical characteristics of river water in mountainous regions is vital for ensuring water security.In this study,we collected a total of 164 water samples in the western region of the Altay Mountains,China,in 2021.We used principal component analysis and enrichment factor analysis to examine the chemical properties and spatiotemporal variations of major ions(including F-,Cl-,NO_(3)-,SO_(4)^(2-),Li+,Na+,NH4+,K+,Mg^(2+),and Ca^(2+))present in river water,as well as to identify the factors influencing these variations.Additionally,we assessed the suitability of river water for drinking and irrigation purposes based on the total dissolved solids,soluble sodium percentage,sodium adsorption ratio,and total hardness.Results revealed that river water had an alkaline aquatic environment with a mean pH value of 8.00.The mean ion concentration was ranked as follows:Ca^(2+)>SO_(4)^(2-)>Na+>NO_(3)->Mg^(2+)>K+>Cl->F->NH_(4)+>Li+.Ca^(2+),SO_(4)^(2-),Na+,and NO_(3)-occupied 83%of the total ion concentration.In addition,compared with other seasons,the spatial variation of the ion concentration in spring was obvious.An analysis of the sources of major ions revealed that these ions originated mainly from carbonate dissolution and silicate weathering.The recharge impact of precipitation and snowmelt merely influenced the concentration of Cl-,NO_(3)-,SO_(4)^(2-),Ca^(2+),and Na+.Overall,river water was in pristine condition in terms of quality and was suitable for both irrigation and drinking.This study provides a scientific basis for sustainable management of water quality in rivers of the Altay Mountains.

Corrosion and wear properties of in situ(TiB+TiC)/TA15 composites with a high volume percentage of reinforcement

The in situ(TiC+TiB)/TA15 composites with different volume percentages of reinforcement(10%,15%,20%and 25%)were prepared by water-cooled copper crucible vacuum suspension melting technology.The structures and compositions of the TA15 alloy and its composites were analyzed by XRD and EDS,and their electrochemical corrosion behaviors in the 3.5%NaCl solution were studied.Corrosion wear testing was conducted using a reciprocating ball-on-disc wear tester under a 10 N load.Results show that the in situ fibrous TiB phase and the granular TiC phase are uniformly distributed on the composite matrix.The microhardness can reach up to 531 HV as 25vol.%TiC+TiB reinforcement is added.Compared with the TA15 alloy,the volume wear rate decreases from(2.21±0.07)×10^(-4)to(1.75±0.07)×10^(-4)mm^(3)·N^(-1)·m^(-1)by adding 15vol.%TiC+TiB reinforcement,and the wear mechanism is adhesive wear.When the volume percentage of the reinforcement phase reaches 25%,the volume wear rate increases from(1.75±0.07)×10^(-4)to(2.41±0.07)×10^(-4)mm^(3)·N^(-1)·m^(-1),and the wear mechanism changes into abrasive wear.The volume loss resulted by the interaction between corrosion and wear accounts for more than 27%of the total wear volume.The volume loss due to wear-induced corrosion changes from 1.94%to 4.06%with different additions of reinforcement.The volume loss caused by corrosion-induced wear initially increases from 24.08%to 26.90%as the reinforcement increases from 0 to 15%due to the increase of corrosion potential,and then decreases from 26.90%to 25.68%as the reinforcement increases from 15%to 25%due to the peeling of TiC phase.

Global burden of inflammatory bowel disease 1990-2019:A systematic examination of the disease burden and twenty-year forecast

BACKGROUND Inflammatory bowel disease(IBD)is an idiopathic intestinal disease with various levels and trends in different countries and regions.Understanding the current burden and trends of IBD in various geographical locations is essential to establish effective strategies for prevention and treatment.We report the average annual percentage change(AAPC)and estimated annual percentage change(EAPC)in age-standardized rates(ASR)of IBD in different regions based on the Global Burden of Disease(GBD)study from 1990-2019,and the relationships between IBD and the human development index(HDI)and socio-demographic index(SDI).The prevalence trends of IBD were predicted by gender from 2019-2039.AIM To comprehensively investigate IBD data,providing further insights into the management of this chronic disease.METHODS We collected the information on the incidence of IBD from the GBD study from 1990-2019 to calculate the AAPC and EAPC in ASR of IBD in different regions.The relationships between IBD,HDI,and SDI were analyzed.The Nordpred and Bayesian age-period-cohort models were used to predict the prevalence trends of IBD by gender from 2019-2039,and the reliability of the results was validated.RESULTS North America consistently had the highest IBD ASR,while Oceania consistently had the lowest.East Asia had the fastest average annual growth in ASR(2.54%),whereas Central Europe had the fastest decline(1.38%).Countries with a low age-standardized incidence rates in 1990 showed faster growth in IBD while there was no significant correlation in 2019.Additionally,IBD increased faster in countries with a low age-standardized death rates in 1990,whereas the opposite was true in 2019.Analysis of SDI and IBD ASR showed that countries with a high SDI generally had a higher IBD ASR.Finally,the projections showed a declining trend in the incidence of IBD from 2019-2039,but a gradual increase in the number of cases.CONCLUSION As the global population increases and ages,early monitoring and prevention of IBD is important to reduce the disease burden,especially in countries with a high incidence of IBD.

Output Linearization of Single-Input Single-Output Fuzzy System to Improve Accuracy and Performance

For fuzzy systems to be implemented effectively,the fuzzy membership function(MF)is essential.A fuzzy system(FS)that implements precise input and output MFs is presented to enhance the performance and accuracy of single-input single-output(SISO)FSs and introduce the most applicable input and output MFs protocol to linearize the fuzzy system’s output.Utilizing a variety of non-linear techniques,a SISO FS is simulated.The results of FS experiments conducted in comparable conditions are then compared.The simulated results and the results of the experimental setup agree fairly well.The findings of the suggested model demonstrate that the relative error is abated to a sufficient range(≤±10%)and that the mean absolute percentage error(MPAE)is reduced by around 66.2%.The proposed strategy to reduceMAPE using an FS improves the system’s performance and control accuracy.By using the best input and output MFs protocol,the energy and financial efficiency of every SISO FS can be improved with very little tuning of MFs.The proposed fuzzy system performed far better than other modern days approaches available in the literature.

Integrated Approach of Brain Disorder Analysis by Using Deep Learning Based on DNA Sequence

In order to research brain problems using MRI,PET,and CT neuroimaging,a correct understanding of brain function is required.This has been considered in earlier times with the support of traditional algorithms.Deep learning process has also been widely considered in these genomics data processing system.In this research,brain disorder illness incliding Alzheimer’s disease,Schizophrenia and Parkinson’s diseaseis is analyzed owing to misdetection of disorders in neuroimaging data examined by means fo traditional methods.Moeover,deep learning approach is incorporated here for classification purpose of brain disorder with the aid of Deep Belief Networks(DBN).Images are stored in a secured manner by using DNA sequence based on JPEG Zig Zag Encryption algorithm(DBNJZZ)approach.The suggested approach is executed and tested by using the performance metric measure such as accuracy,root mean square error,Mean absolute error and mean absolute percentage error.Proposed DBNJZZ gives better performance than previously available methods.

Value-Based Test Case Prioritization for Regression Testing Using Genetic Algorithms

Test Case Prioritization(TCP)techniques perform better than other regression test optimization techniques including Test Suite Reduction(TSR)and Test Case Selection(TCS).Many TCP techniques are available,and their performance is usually measured through a metric Average Percentage of Fault Detection(APFD).This metric is value-neutral because it only works well when all test cases have the same cost,and all faults have the same severity.Using APFD for performance evaluation of test case orders where test cases cost or faults severity varies is prone to produce false results.Therefore,using the right metric for performance evaluation of TCP techniques is very important to get reliable and correct results.In this paper,two value-based TCP techniques have been introduced using Genetic Algorithm(GA)including Value-Cognizant Fault Detection-Based TCP(VCFDB-TCP)and Value-Cognizant Requirements Coverage-Based TCP(VCRCB-TCP).Two novel value-based performance evaluation metrics are also introduced for value-based TCP including Average Percentage of Fault Detection per value(APFDv)and Average Percentage of Requirements Coverage per value(APRCv).Two case studies are performed to validate proposed techniques and performance evaluation metrics.The proposed GA-based techniques outperformed the existing state-of-the-art TCP techniques including Original Order(OO),Reverse Order(REV-O),Random Order(RO),and Greedy algorithm.

Global, regional, and national burden of gallbladder and biliary diseases from 1990 to 2019

BACKGROUND Gallbladder and biliary diseases(GABDs)are a major public health issue.AIM To analysis the cause-specific incidence,prevalence,and years lived with disability(YLDs)and its temporal trends of GABDs at the global,regional,and national level.Data on GABD were available from the Global Burden of Disease study 2019.METHODS The estimated annual percentage change(EAPC)was used to quantify temporal trend in GABD age-standardized incidence rates(ASIRs),age-standardized prevalence rate(ASPR),and age-standardized YLD rate(ASYR)by region,sex.We analyzed the relationship between the GABD burden and country development level using the human development index(HDI).RESULTS In 2019,the incident cases of GABD were 52003772,with an ASIR of 63432/100000 population.Globally,the number of incident cases and ASIR of GABD increased 97%and 58.9%between 1990 and 2019.Although,the ASPR and ASYR decreased from 1990 to 2019,the number of prevalent and YLDs cases increased.The highest ASIR was observed in Italy,and the highest ASPR and ASYR was observed in United Kingdom.The highest burden of GABD was found in low-SDI region,and the burden in female was significantly higher than males.A generally negative correlation(ρ=-0.24,P<0.05)of GABD with the EAPC and human development index(HDI)(in 2021)were observed for ASIR.What’s more,no correlation in ASPR(ρ=-0.06,P=0.39)and ASYR(ρ=-0.07,P=0.36)of GABD with the EAPC and HDI(in 2021)were observed,respectively.CONCLUSION GABD remain a major global public health challenge;however,the burden of GABD varies geographically.Globally,the number of incident cases and ASIR of GABD increased between 1990 and 2019.The results of our study provide insight into the global disease burden of GABD and may assist policymakers in formulating effective policies to mitigate modifiable risk factors.

Variation Characteristics of Droughts and Floods in Deyang Area in the Past 30 years

Based on the data of annual average precipitation in Deyang area and its five stations (Mianzhu, Deyang, Zhongjiang, Shifang and Guanghan) from 1984 to 2013, the annual precipitation anomaly percentage was calculated, and then the flood and drought situation in Deyang area was graded to discuss the variation characteristics of droughts and floods in the past 30 years. The results show that the cycle of droughts and floods in Deyang was about 3-5 a. The precipitation anomaly percentage indicates that the climate in Deyang area of Sichuan tended to be dry slowly in the past 30 years, and Deyang gradually entered a dry and warm period.

白花除虫菊四倍体与二倍体株系花粉粒的比较研究(摘要)(英文)

[目的]研究白花除虫菊四倍体株系与二倍体对照株系花粉的形态特征及其育性和种子发芽率。[方法]采用硫酸-醋酸酐分解法制备花粉,用普通光学显微镜观察并测量花粉的极轴和赤道轴长度,用扫描电镜观察花粉粒形态,并选取有代表性的视野2500×(或2000×)、7000×进行拍摄。[结果]四倍体株系与二倍体对照株系比较,供试的5个四倍体株系花粉粒样品中有4个样品的极轴与赤道轴的长度均显著大于对照二倍体,只有1个样品与对照相近。5个多倍体株系的花粉粒在形态,表面雕纹等方面均与二倍体对照有差异。[结论]为选育出育性良好、种子发芽率高的白花除虫菊优良四倍体品种提供参考依据。

A Complete Analysis of Clarity(C50)Using I-SIMPA to Maintain Ideal Conditions in an Acoustic Chamber

In any closed environment considered,it can be seen that the acoustic parameters are inherently not constant over the entire area considered.In a closed environment,it is ideally preferred to maintain the acoustic parameters as constant so that there exists better quality of sound leading to better auditory perception with respect to the audience.Practically,some of the acoustic parameters like reverberation time and clarity do not strictly pertain to the pattern obtained theoretically.In this paper,simulations are carried out using I-SIMPA under different values of Sound Transmission Class(STC),source position,distribution and the chamber dimensions and provides an insight into the behaviour of these acoustic parameters and the appropriate values that have to be infused into the system to build the chamber.The acoustic environment is modelled keeping an actual closed room in mind and testing is done with respect to different values of surface absorption coefficients(practically indicated using Sound Transmission Class)and dimensions to determine ideal conditions.

Effect of seed priming with different concentrations of potassium nitrate on the pattern of seed imbibition and germination of rice(Oryza sativa L.)

Low germination and vigor of rice seed associated with dry-seed broadcasting are common problems encountered by rice growers.The objectives of this study were to evaluate the role of potassium nitrate（KNO3）on the pattern of seed imbibition and to determine the effect of seed priming with KNO3 on the germination percentage,speed and uniformity of germination in rice seed.Experiment 1 compared the patterns of seed imbibition of six concentrations of KNO3（0,0.25,0.50,1.00,1.50,and 2.00%）in two rice cultivars-KDML105 and RD15.The results showed that soaking rice seed in KNO3 at higher concentrations could delay the imbibition time.The higher concentrations of KNO3 delayed the imbibition time of rice seed and took a longer time to reach the end of phases 1 and 2 compared to the lower concentrations.The patterns of seed imbibition using distilled water of both rice cultivars（KDML105 and RD15）were quite similar,but with different concentrations of KNO3,the imbibition time taken to reach the end of phases 1 and 2 was slightly postponed in KDML105 suggesting that different rice cultivars may need different imbibition times for soaking seed in the priming process.Experiment 2 evaluated the effects of seed priming with 1.0 and 2.0%KNO3 at different imbibition times.It was found that priming with 1.0%KNO3 showed better seed germination than priming with 2.0%KNO3 and seed priming with 1.0%KNO3 at the imbibition time of early phase 2（or 28 h for KDML105）improved seed germination and increased both the speed and uniformity of seed germination.The results of this study show promise for the use of priming with 1.0%KNO3 soaked until early phase 2 of seed imbibition for improving the seed germination and vigor of rice in dry seed broadcasting.

Seismic performance of recycled concrete-filled square steel tube columns

An experimental study on the seismic performance of recycled concrete-filled square steel tube （RCFST） columns is carried out. Six specimens were designed and tested under constant axial compression and cyclic lateral loading. Two parameters, replacement percentage of recycled coarse aggregate （RCA） and axial compression level, were considered in the test. Based on the experimental data, the hysteretic loops, skeleton curves, ductility, energy dissipation capacity and stiffness degradation of RCFST columns were analyzed. The test results indicate that the failure modes of RCFST columns are the local buckling of the steel tube at the bottom of the columns, and the hysteretic loops are full and their shapes are similar to normal CFST columns. Furthermore, the ductility coefficient of all specimens are close to 3.0, and the equivalent viscous damping coefficient corresponding to the ultimate lateral load ranges from 0.323 to 0.360, which demonstrates that RCFST columns exhibit remarkable seismic performance.

Illite Crystallinity Mapping of Very Low Grade Metamorphism of Triassic Metapelites in the Zoigê Area,Western China

X-ray diffraction methods for estimating the metamorphic grade of diagenetic, anchizone and epizone in metapelites are reviewed and applied to samples from a 7000 m＋ borehole in western China and surface samples from the surrounding Zoige area. Kiibler＇s illite crystallinity （IC） measurements provide more consistent results than calculated values of percentage of illite in the I/S mixed layers and percentage of I/S mixed layers. Down-borehole IC values display a typical burial metamorphic relationship between stratigraphic level and IC. A method for preparing very low grade metamorphic maps is described, and isograds plotted on a regional geological map at selected values of IC, delineating a high temperature diagenetic zone, an anchizone, and an epizone. The map shows that IC values are controlled by stratigraphic level in the north of the study area （i.e. burial metamorphism）, and proximity to an igneous intrusive body in the south （i.e. contact metamorphism）.

Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains

Objective:To investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz.,methanol,ethanol and water extracts of the selected plant Ricinus communis.Methods:Ager well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol,ethanol and aqueous extracts.Results:Metbanol leaf extracts were found to be more active against Gram positive bacteria(Bacillus subtilis:ATCC 6059 and Staphylococcus aureus:ATCC 6538)as well as Gram negative bacteria(Pseudomonas aeruginosa:ATCC 7221 and Klebsiella pneumoniae)than ethanol and aqueous leaf extracts.Antifungal activity of methanol and aqueous leaf extracts were also carded out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus.Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth.Conclusions:The efficient antibacterial and antifungai activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts.

Vibration reduction evaluation of a linear system with a nonlinear energy sink under a harmonic and random excitation

The nonlinear behaviors and vibration reduction of a linear system with a nonlinear energy sink(NES)are investigated.The linear system is excited by a harmonic and random base excitation,consisting of a mass block,a linear spring,and a linear viscous damper.The NES is composed of a mass block,a linear viscous damper,and a spring with ideal cubic nonlinear stiffness.Based on the generalized harmonic function method,the steady-state Fokker-Planck-Kolmogorov equation is presented to reveal the response of the system.The path integral method based on the Gauss-Legendre polynomial is used to achieve the numerical solutions.The performance of vibration reduction is evaluated by the displacement and velocity transition probability densities,the transmissibility transition probability density,and the percentage of the energy absorption transition probability density of the linear oscillator.The sensitivity of the parameters is analyzed for varying the nonlinear stiffness coefficient and the damper ratio.The investigation illustrates that a linear system with NES can also realize great vibration reduction under harmonic and random base excitations and random bifurcation may appear under different parameters,which will affect the stability of the system.