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简介：Sometimelakesare"drawndown"ordrainedinwintertopreventshorelinedamagefromthefreezingwater.

简介：Thetransmissionpropertiesofone-dimensionalphotoniccrystalscontainingdouble-negativeandsingle-negativematerialsarestudiedtheoretically.Aspecialkindofphotonicbandgapisfoundinthisstructure.Thisgapisinvariantwithscalingandinsensitivetothicknessfluctuation.Butwhenchangingtheratioofthethicknessoftwomedia,thewidthofthegapcouldbeenlarged.Thedefectmodesareanalyzedbyinducingalineardefectlayerinthestructure.Itisfoundthatthenumberofdefectmodeswillincreasewhenthethicknessofthedefectlayerbecomeslarger.更多还原

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简介：Studiesonbrain-evokedpotentialandcontingentnegativevariation(CNV)inmooddisorderremaincontroversial.Todate,noCNVdifferencebetweenunipolarandbipolardepressionhasbeenreported.Brain-evokedpotentialsweremeasuredinthepresentstudytoanalyzeCNVinthreesubtypesofmooddisorder(mania,unipolardepression,andbipolardepression),andtheseresultswerecomparedwithnormalcontrols.Inthemaniagroup,CNVamplitudeBwasgreaterthanincontrols,andthedepressiongroupexhibitedlowerCNVamplitudeBandsmallerA-S'2area,andprolongedpost-imperativenegativevariationlatency.TheCNVcomparisonbetweenunipolarandbipolardepressionfoundthattheprolongedpost-imperativenegativevariationlatencywasonlyinunipolardepression.Theseresultssuggestthatprolongedpost-imperativenegativevariationlatencyisacharacteristicofunipolardepression,andCNVamplitudechangeisastatecharacteristicofmooddisorderpatients.

简介：Background:Oneofthemostimportantdriversofforestbiodiversityisconspecificnegativedensitydependence(CNDD),areductioninperformancewhenconspecificdensitiesarehigh.WhilethemajorityofCNDDresearchhasfocusedontropicalforests,evidenceismountingthatCNDDmayalsoplayanimportantroleintemperateforests.Tofurtherexplorethepotentialreachofthisphenomenon,weinvestigatedCNDDinAmericanbeech(Fagusgrandifolia)inamaturemid-Atlanticforest.Methods:Weusedbivariatepointpatternanalysestoexaminespatialrelationshipsbetweenlargebeechtreesandconspecificsaplings,andwealsocontrastedthesepatternswithcomparablepatternsforheterospecifics.Inaddition,toaddressthepossibilityofdispersallimitationandtheassociatedeffectsonspatialpatterns,weanalyzedseedlingdensityasafunctionofadultconspecificabundance.Results:Wefoundthatbeechsaplingsweremorerepeledfromlargeconspecificsthanlargeheterospecifics,despitethefactthatbeechseedlingdensitywaspositivelycorrelatedwithbeechbasalarea.However,saplingsofothercanopytreespecieswerealsorepeledfromadultbeechtrees,suggestingageneralsuppressiveeffect.Nonetheless,thediscrepancybetweenbeechseedlingandsaplingdensitiesbeneathadultconspecificssuggeststhatbeechseedlingsurvivalrateswerereducedinvicinityofconspecificadults.Conclusions:Regardlessoftheextenttowhichbeechinhibitsheterospecifictrees,anegativeeffectonconspecificrecruitsmaybecriticalforbiodiversitymaintenance.Withoutthisconspecificsuppression,adenselayerofshade-tolerantbeechsaplingscouldformbeneathadultbeechtrees.Ifthisweretooccur,beechwouldhaveasubstantialhead-startfolowingcanopydisturbance,andthislate-successionalspeciescouldpotentialydominateastandinperpetuity,throughrepeateddisturbancecycles.

简介：这篇文章介绍hypersingular积分的近似?abg(x)(x-t)dx并且?abg(x)|x-t|有任意的单个点t的dx(一，b)并且否定部分数字<-1。这些一般扩大对hypersingular积分的一个大范围适用，包括在文学和还没被探讨的另外的重要的讨论的两流行hypersingular积分。相应中间矩形的公式和推测，能以相当直接的方法计算，被调查。数字例子被提供说明数字方法的特征并且验证理论结论。

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简介：适当地在米饭(OryzasativaL.)为否定向光性探索光敏电阻器根，有不同波长的灯被使用在phototropic弯曲上调查轻质量的效果。弯曲的phototropic能被蓝/紫外的光显著地导致，而不由红或far-red光。分别地，从米饭根帽子的提取答案的吸收光谱在350nm和450nm有二座山峰，在在单方的光下面的根帽子的120kD蛋白质的分子的重量在黑暗下面比那大。它建议蓝轻受体可能是为在米饭根的否定向光性的光敏电阻器。

简介：TheauthorconsiderstheproblemofdeformingthemetriconacompletenegativelycuredsurfaceconformaltoanothermetricwhoseGausscurvatureisnonpositive.

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简介：Thispaperdiscussesdebtrun'screditrisk,analysesitsfinancelever'spositiveandnegativeeffects,giveabenefitconclusionandsuggestion.

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简介：WhilenegativetransferofthenativelinguisticknowledgeinSLAiscloselystudied,otheraspectsofthelearner’snativeknowledgehavebeenignored.Thefollowingisaninvestigationandstudyinthisrespect,revealingthatnegativetransfernoton-lyhappensintheaspectofthelearner’snativelinguisticknowl-edgesuchasthatofthenativegrammaticalrulesandlexicalcon-ception,butalsohappensinaspectsofculturalconventionsandthinkingpatterns.Itisalsofoundthatnegativetransferoflin-guisticknowledgedecreaseswiththelearner’sprogressinstudywhiletheothertwoaspectshavenoobviousdecrease.WithLevel3asacontrolgroup,thispaperconfirmedtheeffectivenessandnecessityinofferingclassesdealingwiththeothertwoaspectsofnegativetransfer.

简介：Inthispaperweconsidersomerelatednegativehypergeometricdistributionsarisingfromtheproblemofsamplingwithoutreplacementfromanurncontainingballsofdifferentcoloursandindifferentproportionsbutstoppingonlyaftersomespecificnumberofballsofdifferentcolourshavebeenobtained.Withtheaidofsomesimplerecurrencerelationsandidentitiesweobtaininthecaseoftwocoloursthemomentsforthemaximumnegativehypergeometricdistribution,theminimumnegativehypergeometricdistribution,thelikelihoodrationegativehypergeometricdistributionandconsequentlythelikelihoodproportionalnegativehypergeometricdistributiuon.TotheextentthatthesamplingschemeisapplicabletomodellingdataasillustratedwithabiologicalexampleandinfactmanysituationsofestimatingBernoulliparametersforbinarytraitswithinafinitepopulation,theseareimportantfirst-stepresults.

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简介：Triple-negativebreastcancer(TNBC)isdiagnosedmorefrequentlyinyoungerandpremenopausalwomenandishighlyprevalentinAfricanAmericanwomen.TNBCisatermderivedfromtumorsthatarecharacterizedbytheabsenceofER,PgR,andHER2.SopatientswithTNBCdonotbenefitfromhormonalortrastuzumab-basedtherapies.TNBCsarebiologicallyaggressive,althoughsomereportssuggestthattheyrespondtochemotherapybetterthanothertypesofbreastcancer,prognosisremainspoor.Thisisdueto:shorteneddisease-freeintervalintheadjuvantandneoadjuvantsettingandamoreaggressivecourseinthemetastaticsetting.

简介：AbstractImportance:Bacteremia tuberculosis (TB) is a severe form of extrapulmonary TB. Studies assessing bacteremia TB in children are limited, especially for HIV-negative children.Objective:To explore the detailed clinical features of the bacteremia TB in children under 18 years of age.Methods:We reviewed the clinical records of the patients retrospectively and collected the strains isolated from their blood cultures. We used mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) to characterize the bacterial genotypes and alamarBlue to determine their drug susceptibility profiles. Polymerase chain reactions and DNA sequencing were used to identify drug-resistant mutations.Results:There were 13 pediatric bacteremia TB patients, 10 of whom were diagnosed with Bacillus Calmette–Guérin (BCG) bacteremia TB. Thirteen patients aged from 0.30 to 11.58 years were enrolled, of whom 76.92% were boys. All had fevers before hospitalization, and 76.92% had respiratory symptoms. All had received BCG vaccinations, and 46.15% had adverse post-vaccination reactions. Compared with Mycobacterium tuberculosis, BCG bacteremia was more likely to appear in younger children. Patients with BCG bacteremia had primary immunodeficiency diseases, and lower CD4, IgA, and IgE levels.Interpretation:Bacteremia TB was rapidly fatal in a large proportion of the immunodeficient children. Because classic findings may not be diagnostically specific, a high level of clinical suspicion is required, especially for patients with certain types of immunosuppression. Studies are needed to develop rapid diagnostic tests and to determine the value of empirical therapy in childhood bacteremia TB.

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