学科分类
/ 5
89 个结果
  • 简介:AbstractPurpose:The use of tourniquet in orthopedic surgery facilitates operation by establishing a bloodless surgical field. However, many complications following the use of tourniquets have been reported. Tourniquet pain is the most common complication. This study aimed to find the actual incidence of pain associated with tourniquet use in orthopedic surgery and the various factors.Methods:It is a prospective observational study conducted on 132 consecutive cases. Patients aged 18-70 years with musculoskeletal problems of the forearm and leg requiring surgery were included in the study. Patients with open injuries or contraindications such as diabetes mellitus, compromised circulatory states, neurological deficit, compartment syndrome and unable to give informed consent were excluded. The parameters assessed included duration of tourniquet use, tourniquet pressure, type of anesthesia, any interval release of the tourniquet and reapplication after a reperfusion period, whether upper or lower limb surgery, severity of tourniquet pain, timing of tourniquet release and complications. Chi-square and non-parametric Mann-Whitney U test were used for data analysis.Results:In upper limb surgeries, if duration of surgery was less than 60 min, 14 (51.8%) cases experienced tourniquet pain and 13 (48.1%) had no pain, and if duration of surgery was more than 60 min, 24 (60.0%) had pain and 16 (40.0%) experienced no pain. In lower limb surgeries if duration of surgery was less than 60 min, 2 (7.7%) experienced pain and 24 (92.3%) had no pain, and if duration of surgery was more than 60 min, 14 (35.8%) experienced pain and 25 (64.8%) had no pain. Degree of tourniquet pain increases with the duration of surgery. Statistically, there was significant association between tourniquet inflation time and tourniquet pain in both upper and lower limbs (p = 0.034 and 0.024, respectively)Conclusion:Incidence of tourniquet pain was in direct proportion to the duration of tourniquet use and was higher in cases with regional anesthesia. Other risk factors assessed including tourniquet pressure, upper or lower limb surgery, tourniquet release time and interval had no significant contribution to the incidence or severity of tourniquet pain.

  • 标签: Tourniquet pain Pneumatic tourniquet Bloodless field Orthopedic surgery Complications Pain intensity
  • 简介:-Byusinggas-liquidtwo-phaseflowtheory,amodifiedmathematicalmodelbasedonthecomputationalfluiddynamicsmethodSIMPLE(Semi-ImplicitMethodforPressure-LinkedEquations)isintroducedtoinvestigateimplosionphenomenainhighpressurechamberssystematically.Atheoreticalsimulation-predictionmethod,whichisindependentofexperimentaldata,isdevelopedinthepaperandgreatimprovementhasbeenmadeonthetopic.Inthepaper,variousimplosionsituationshavebeensimulatedandpredicted.Effectsofaseriesoffactorsinfluencingimplosionresultsandmethodsofreducingimplosiondangerhavebeenanalysed.Theanalysisresultsareofimportancetounderwaterengineeringpractice.

  • 标签: IMPLOSION TWO-PHASE FLOW IMPLOSION pressure NUMERICAL
  • 简介:Basedontheexploratoryspatialdataanalysis(ESDA)techniqueandgeographicinformationsystem(GIS)platform,withstatisticdataofcountiesin2005,thispaperconfirmsthatthereisalargepopulationdensitygapbetweencountiesin2005becausetheGinicoefficientis0.55.Populationdistributiondoesnotchangealotduringthepastdecades,andthesoutheastChinaisstillmuchmoredenselypopulatedthanthenorthwestChina.TheglobalspatialautocorrelationofpopulationdistributionisobviousbecauseMoran'sIscores0.42andlocalspatialautocorrelationispartlysignificant.Climateandelevationarestillthemainnaturalinfluencingfactors.Meanwhileindustrialstructureandtransportationsignificantlyinfluencepopulationdistribution.Differentcombinationsofnaturalfactorshavedifferenteffectsonpopulationdistribution.Foralongterm,climateandterrainfactorstabilityaffectpopulationdistribution.Butitsinfluencewillbeweakenedbyprogressoftechnology.Economicdevelopmentisthemainfactorthatchangespopulationdistributionforashortterm.

  • 标签: 人口分布 ESDA 影响因素 地理信息系统 空间数据分析 中国西北地区
  • 简介:Thebendingrigidityofsubmergedvegetationiscloselyrelatedwithvegetativedragforce.Thisworkaimsatdeterminingtheeffectsofflowconditionsandcharacteristicsofvegetationonthebendingrigidityofsubmergedvegetation.Basedonthedimensionalanalysismethod,thefactorsinfluencingthebendingrigidityofindividualsubmergedvegetationwereanalyzed.Therelationshipbetweentherelativebendingrigidityanditsinfluencingfactorswasinvestigatedbyexperimentalobservation,andarelativebendingrigidityexpressionforsubmergedvegetationwasobtainedbymeansofmultiplelinearregressionmethod.Theresultsshowthatthesubmergedvegetationhasthreestatesunderdifferentinflowconditions,andtheeachcriticalrelativebendingrigidityofindividualsubmergedvegetationwasdeterminedforthedifferentstatesofsubmergedvegetation.

  • 标签: 抗弯刚度 沉水植物 影响因素 多元线性回归方法 植被特征 三维分析
  • 简介:AbstractObjective:The aim of the study was to investigate the pregnancy outcomes and possible influencing factors concerning complicated monochorionic (MC) multiple pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA).Methods:This retrospective cohort study included 54 women with complicated MC multiple pregnancy who underwent selective fetal reduction using RFA at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2015 to March 2020. According to the indications for RFA, the 54 women were divided into three groups: complex complications (n = 30), structural anomalies (n = 18), and triplet pregnancy (n = 6). According to the gestational age for RFA, all patients were divided into three groups: 16-19+6 weeks (n = 17), 20-23+6 weeks (n = 17), and 24-26+6 weeks (n = 20). We analyzed the pregnancy outcomes (including the overall survival rate (OSR), gestational age at delivery, birth weight of newborns) and postoperative complications such as miscarriage, and intrauterine fetal death (IUFD) according to the indications and gestational age of reduction by using suitable statistical testing.Results:The OSR was 83.3% (45/54). The mean ± standard deviation (SD) of gestation at the time of reduction was 21.6 ± 3.2 weeks. The GA at delivery was 34.0(32.0,37.5) weeks. The mean ± SD of newborns’ birth weight was 2118 ± 685 g. The overall rates of miscarriage, PROM, and IUFD were 9.3% (5/54), 7.4% (4/54), and 7.4% (4/54), respectively. According to the indications for reduction, the OSR for complex complications, structural anomalies, and triplet pregnancy groups were 83.3% (25/30), 83.3% (15/18), and 83.3% (5/6), respectively. Statistically significant differences were only found in the mean birth weight among the three groups (P < 0.05). No significant difference was found in the rate of miscarriage, and mean gestation at delivery among the three groups (P > 0.05). In the group with complex complications, the OSR of twin-to-twin transfusion syndrome, selective intrauterine growth restriction, twin reversed arterial perfusion sequence, and twin anemia polycythemia sequence were 66.7% (6/9), 93.3% (14/15), 80.0% (4/5), and 100.0% (1/1), respectively, with no significant difference among these groups (P > 0.05). According to the gestational age of reduction, the OSRs among the three groups were 82.4% (14/17), 76.5% (13/17), and 90.0% (18/20), respectively, and the rate of miscarriage, IUFD, and mean gestation age at delivery among these groups showed no significant difference (P > 0.05).Conclusion:Selective fetal reduction by RFA is an important treatment method for complicated MC multiple pregnancy, although it may lead to complications like miscarriage, and IUFD. The indication of reduction seems to affect the pregnancy outcome. An optimal treatment plan should be selected according to the patient’s conditions in clinical practice.

  • 标签: Twins Monochorionic pregnancies Fetal reduction Radiofrequency ablation Pregnancy outcomes Influencing factors
  • 简介:Agriculturalgreenhousegasaccountsforalargeproportionofglobalanthropogenicgreenhousegasemission.ThepapercarriedonacalculationongreenhousegasemissionofChinaagriculturalgreenhousegasemission,andanalyzedinfluencingfactorsofagriculturegreenhousegasemissionwhichhasimportantsignificanceforthedevelopmentofChineseandgloballowcarbonagriculture.ThispapercalculatedtheemissionofCH4,N2OandCO2inChinafromtheyearof1993to2011,andanalyzedtheinfluencefactors.TheresultsshowedthatCH4emissionwasbasicallystable,whichmaintainedat2000tons.AnimalhusbandryCH4emissionwasthelargestcontributorofagriculturalsourceCH4emission.Takingtheyearof2011asanexample,whichaccountedfor53.08%;N2Oemissionwasincreasedfrom93.21tonsof1993to120.51milliontonsof2011,andtheaverageannualgrowthratewas1.63%.PlantingwasthemaincontributortoN2Oemission.Takingtheyearof2011asanexample,whichaccountedfor54.36%ofthetotalemission,landN2Oemissionwasthemost,andthericefieldwasfollowed;agriculturalsourceCO2emissionincreasedfrom15626.98to31258.10milliontons,andtheaverageannualgrowthratewas5.56%;fertilizersourcewasthelargestsourceofcarbon,in2011,forexample,fertilizersourceofCO2emissionwas18731.83milliontonsaccountedfor59.93%oftheagriculturalsourceCO2emission.CH4andN2OemissionsofChinaAgricultureweremainlycausedbyanimalhusbandryandchemicalfertilizers.AndpesticidesweremajorcontributorstoCO2emissionofagriculture.Attheendofthispaper,basedontheresultsofcorrelationanalysis,thepaperproposedcountermeasuresandsuggestionsforChina’slowcarbonagriculture,anddemonstratedthesignificanceofgloballowcarbonagriculturedevelopment.

  • 标签:
  • 简介:Inordertosearchforthemeasuretoincreasetheenergydissipationratioofsteppedspillways,somemaininfluencingfactorsfortheenergydissipationratioofsteppedspillways,suchasunitdischarge,damslope,heightofstepandsoon,werestudied.Theresultsshowthattheenergydissipationratiodecreaseswiththeincreaseintheunitdischargeandincreasesastheslopebecomesgentle.Theeffectsofstepheightontheenergydissipationratioarecloselyrelatedtounitdischarge.Iftheunitdischargeissmaller,thechangeofenergydissipationratiowithstepheightbecomesgreater.While,iftheunitdischargeisgreater,theinfluenceofstepheightonenergydissipationratioisverylittle.Accordingtothedistributionsoftheturbulencekineticenergyandturbulencedissipationrateobtainedbynumericalsimulation,thebasicreasonofthedecreaseofenergydissipationratiowiththeincreaseintheunitdischargewasdiscussedandsomespecificmeasurestoincreasetheenergydissipationratioweresuggested.

  • 标签: 溢洪道 数值仿真 放电单元 大坝坡度 能量损失率
  • 简介:Atrapezoidvalleysiteischosenasaresearchsite,andaccordingtonumericalmodelsbasedonorthogonaldesign,thefactorsinfluencinggroundmotioninthevalleysitearestudiedwithtwo-dimensionalfinitedifferencemethod.Theinfluencingfactorsareranked,andthenthecalculationresultsareverifiedbygroundmotionanalysis.Theconclusionsareasfollows:therearefourfactorsthathaveimportanteffectsongroundmotionoftrapezoidvalleysites,buttheeffectsaredifferentasthelocationofsiteschanges,theinfluencingfactorsrankdifferentlywithdifferentsitelocations;Therankingoftheinfluencingfactorsisthesameforallthesiteslocatedwithinadistanceof40mfromthevalley'sside,amongthem,themosteffectiveoneisthevalleyslopeangleranks,followedbydepth-to-widthratio,overburdenthickness,atlasttheinputgroundmotionintensity.Theimpactofthefactorsonsurfacegroundmotionisroughlythesameinthevalleysiteswithinacertaindistancetothevalleyside,andthegeometricparametersofthevalleyterrainplayagreaterpartininfluencinggroundmotion.Withtheincreaseofdistanceawayfromthevalley'sside,therankingoftheinfluencingfactorsalsochanges,theratingofslopeanglemovesbackward,therankingoftheinputgroundmotionandoverburdenthicknessmoveahead.Theeffectofvalleygeometricparametersongroundmotionsisgraduallyweakened,buttheeffectofothertwoinfluencefactorsaregraduallyincreased,similartocasesofahorizontallayeredsite.StrongmotionrecordsinAnningRivervalleysitewereanalyzed,andtheresultsshowthatthevalleytopographyhasasignificantamplificationeffectongroundmotion,andthatthenumericalresultsofthispaperarecredible.

  • 标签: VALLEY SITE Ground motion FINITE DIFFERENCE
  • 简介:AbstractLong-term and stable preservation of bacteriophages is of crucial importance. Although many efforts have been made in the past decades to explore the influence of external factors on bacteriophage preservation, there is still little understanding, and a systematic description is lacking. In this study, we explored the influence of different factors on the preservation of lytic bacteriophage VP3, one of the typing bacteriophages of Vibrio cholerae O1 biotype El Tor, and attempted to optimize its preservation. We examined external factors, including temperature, solution, and cryoprotectant, in stable cooling/freezing conditions or alternate cooling/freezing and thawing. We found that whether in Luria-Bertani (LB) medium or SM buffer, in terms of 20-week stable cooling or freezing, -20 °C was the most damaging while 4 °C, -80 °C, and -196 °C were protective. Thirteen cycles of alternate cooling/freezing and thawing caused a loss in the survival rates of bacteriophages. The addition of cryoprotectant, glycerol (30%, w/v) or dimethyl sulfoxide (DMSO, 10%, w/v) significantly improved the survival rates of bacteriophages preserved at -20 °C. However, at 4 °C, -80 °C, and -196 °C, the cryoprotectant effect was only slightly positive or even harmful. In summary, for bacteriophage VP3, the best preservation method is to directly preserve the bacteriophage stocks in LB medium at -80 °C or -196 °C instead of storing them in SM buffer or adding cryoprotectant. Our results provided insights into the external influencing factors on bacteriophage VP3 during preservation at low temperature and can be applied to the optimization of bacteriophage preservation in the future.

  • 标签: Influencing factors Preservation Lytic bacteriophage Cryoprotectant
  • 简介:OnthebasisofdatacollectedfromLiupanshanpoverty-riddenareas,thepaperselects24variablesunder4groupstofigureouttheinfluencingfactorsofsubjectivewell-being(SWB)ofpeasantsinecologicalmigrationwiththemethodofOrderedProbitRegression.Asisshownintheresults,variablesunderpeasants’personalendowmentgroupandresourceofthedevelopmentgrouphavelittleimpactonpeasants’SWB.Thevariableswithobservableimpactareconcentratedinthelivingconditiongroupandthepublicatmospheregroup.

  • 标签:
  • 简介:Factorsinfluencingbondingstrengthoflaminatedbamboostripslumber(LBSL)wereinvestigatedinthispaper.Inordertofindanoptimizedtechnology,thispaperinvestigatedhowthethicknessofbamboostrips,theassemblyorientationofbamboocurtain,thetypeofadhesives,aswellascouplingagenttreatmentofbamboocurtainaffectedthebondingstrength.Thefollowingconclusionsweredrawn:1)Thethinnerthethicknessofthebamboostrips,thebiggerthebondingstrengthofLBSL;2)Theassemblyor...

  • 标签:
  • 简介:Fineroots(≤2mmindiameter)playimportantrolesincarbonbalanceandnutrientrecyclinginforestecosystem.Withthedevelopmentofthestudyonglobalcarboncycle,finerootshaveattractedconsiderableattentionasthemainsourceofsoilcarboninforestecosystem.Onthebasisofsyntheticanalysisofresearchreportsindomesticandforeignliteratures,wesummarizedandelaboratedthemajorabioticandbioticfactorsthatcontrolfinerootproductionandturnover.Theenvironmentalfactorsincludedsoilnutrient,soiltemperature,soilmoistureandtheCO2concentration.Soilorganisms,finerootmorphologyandforeststandcharacteristicswerediscussedasbioticfactorsinthispaper.Finally,wedefinedtheproblemsarisinginrootsystemresearchandprospectedthefutureresearchdirection.

  • 标签: FINE ROOT production FINE ROOT TURNOVER
  • 简介:Theformationofbrominatedtrihalomethanes(THMs-Br)whichisprovedmorecarcinogenicthantheirchlorinatedanaloguesreportedwasverydifferentatvariouswaterqualities.Thisstudywasperformedtoassesstheeffectsofwaterqualityparameters(bromideconcentration,pHvalueandammoniaconcentration),chlorinationconditions(chlorinedose,reactiontime)andratiosofBr-/DOCandBr-/Cl2consumptionontheformationanddistributionofTHMs-Brinchlorination.Theresultsshowedgoodcorrelationbetweenthebromineincorporationfactor(BIF)n(Br)andBr-/Cl2consumptionratio.TheformationoftotalTHM(TTHM)wasfoundtodecreasewithincreasingammoniaconcentrationbuttoincreasewithbromideconcentrationandpHvalue.Then(Br)trendsweresignificantlyaffectedbythepresenceofbromideconcentration.TheeffectsonthemolaryieldsofTHMsweremorestronglyinfluencedbybromideconcentrationanddissolvedorganiccarbon(DOC)concentrationthanpHvalueandnaturalorganicmatter(NOM)source.HighBr-/DOCandBr-/Cl2favortheformationofTHMs-BroverchlorinatedTHMs(THMs-Cl).Theexperimentaldataincludingthemainparameterssuchasbromide,DOC,ammonia,pHandreactiontimewereusedfordevelopingthepredictivemodelforTHMs-Br.

  • 标签: 甲烷形成 溴化 氯化 影响因素 饮用水 三卤甲烷
  • 简介:Pulsatilebloodflowsincurvedatheroscleroticarteriesarestudiedbycom-putersimulations.Computationsarecarriedoutwithvariousvaluesofphysiologicalparameterstoexaminetheeffectsofflowparametersonthedisturbedflowpatternsdownstreamofacurvedarterywithastenosisattheinnerwall.Thenumericalre-suitsindicateastrongdependenceofflowpatternonthebloodviscosityandinletflowrate,whiletheinfluenceoftheinletflowprofiletotheflowpattemindownstreamisnegligible.

  • 标签: 曲动脉 动脉粥样硬化 血液流动 剪切应力
  • 简介:TakingNingxiaHuiAutonomousRegionasanexample,thisresearchmakesanempiricalanalysisonthefactorsinfluencingthemigrationactivitiesoftheresearchsubject:thesouthernmountainousfarmerswhodon'temigrateandthefarmerswhoimmigratedinHongsibaoDevelopmentZone.WithProbitModel,theresearchshowsthattheage,educationaldegree,farminglandpercapita,numberofschool-agedchildren,vocationaltrainingexperienceandthequantityofgainedinformationareallthefactorswhichinfluencethefarmers'emigrationchoice.However,theinfluentialstrengthofthefactorsisdifferent.Theresearchaimstoprovidethegovernmentwithmorescientificevidencesforitspoliciesofpromotingecologicalmigrationandtoencouragemorepovertyfamiliestoimmigrateintotheareassuitableforliving.

  • 标签: 中国 少数民族地区 生态迁徙 生态环境