简介：AbstractBackground:Mastectomy techniques have been extended to nipple-sparing mastectomy (NSM). This study aimed to assess the actual application of NSM in China and identify the factors influencing postoperative complications.Methods:The clinical data of 615 patients (641 surgeries) undergoing NSM from January 1st, 2018 to December 31st, 2018 at 28 centers nationwide were retrospectively analyzed to obtain the rate of NSM and investigate factors related to NSM surgery.Results:The proportion of NSM surgery performed in this study was 2.67% (17/641). Malignant breast tumors accounted for the majority of NSM surgery (559/641, 87.2%). A total of 475 (77.3%) patients underwent NSM combined with reconstructive surgery. The rate of reconstruction decreased with age in our study, and implants were the most common option (344/641, 53.7%) in reconstruction. Radial incision was the most selected method regardless of reconstruction. However, for those who underwent reconstruction surgery, 18.4% (85/462) of cases also chose curvilinear incision, while in the simple NSM surgery group, more patients chose circumareolar incision (26/136, 19.1%). The tumor-to-nipple distance (TND) influenced postoperative complications (P = 0.004). There were no relationships between postoperative complications and tumor size, tumor location, histologic grade, molecular subtype, nipple discharge, and axillary lymph nodes.Conclusions:NSM surgery is feasible and only TND influenced postoperative complications of NSM surgery. But the proportion of NSM surgery performed is still low in nationwide centers of China. The selection criteria for appropriate surgical methods are important for NSM in clinical practice. To optimize clinical applications of NSM, further multicenter prospective randomized controlled studies are needed.Trial Registration:ChiCTR.org.cn, ChiCTR1900027423; http://www.chictr.org.cn/showprojen.aspx?proj=38739

简介：AbstractBackground:Although de novo stage IV breast cancer is so far incurable, it has entered an era of individualized treatment and chronic disease management. Based on systemic treatment, whether the surgical resection of primary or metastatic foci of de novo stage IV breast cancer can bring survival benefits is currently controversial. We aimed to explore the clinicopathological factors and current status of the management of de novo stage IV breast cancer in China to provide a reference for clinical decisions.Methods:Based on the assistance of Chinese Society of Breast Surgery, a retrospective study was conducted to analyze the clinical data of patients with de novo stage IV breast cancer in 33 centers from January 2017 to December 2018. The relationship between basic characteristic (age, menstrual status, family history, reproductive history, pathological type, estrogen receptor [ER] status, progesterone receptor [PR] status, human epidermal growth factor receptor 2 [HER2] status, Ki-67 percentage, and molecular subtype), and metastasis sites (lung metastasis, liver metastasis, and bone metastasis) was examined by Pearson Chi-square tests.Results:A total of 468 patients with de novo stage IV breast cancer were enrolled. The median age of the enrolled patients was 51.5 years. The most common pathological type of primary lesion was invasive carcinoma (97.1%). Luminal A, luminal B, HER2 overexpressing, and triple-negative subtypes accounted for 14.3%, 51.8%, 22.1%, and 11.8% of all cases, respectively. Age, PR status, and HER2 status were correlated with lung metastasis (χ2= 6.576, 4.117, and 8.643 and P = 0.037, 0.043, and 0.003, respectively). Pathological type, ER status, PR status, and molecular subtype were correlated with bone metastasis (χ2 = 5.117, 37.511, 5.224, and 11.603 and P = 0.024, <0.001, 0.022, and 0.009, respectively). Age, PR status, HER2 status, Ki-67 percentage, and molecular subtype were correlated with liver metastasis (χ2= 11.153, 13.378, 10.692, 21.206, and 17.684 and P= 0.004, <0.001, 0.001, <0.001, and 0.001, respectively). Combined treatment with paclitaxel and anthracycline was the most common first-line chemotherapy regimen for patients with de novo stage IV breast cancer (51.7%). Overall, 91.5% of patients used paclitaxel-containing regimens. Moreover, 59.3% of hormone receptor-positive patients underwent endocrine therapy.Conclusions:In 2018, 1.07% of patients from all studied centers were diagnosed with de novo stage IV breast cancer. This study indicated that 95.1% of patients received systemic therapy and 54.2% of patients underwent surgical removal of the primary lesion in China.

简介：Ultrasonicbiophysicistsandphysicianshavecontinuouslyexhibitedgreatinterestinstudyingtheultrasonicpropertiesofblood.Itisshownthatcompressibilityofredcellappearstobeinverselypropor-tionalwithitshemoglobincontent.Amongultrasonicattenuationproducedbyredcellstructurelevelinblood,absorptionofredcellplayspredominantrole,viscousrelativemotionlossaccountsforlessthan15%,andcellscatteringcontributionisnegligible.Thecoagulationprocessofbloodisaccompaniedbysignificantchangeofsoundparameters.Themarkedadvantagehasbeenfoundintestofbloodcoagula-tionprocessbyusingultrasonictechniquethanthetraditionalviscousmethod.Bloodcoagulationcausessoundattenuation,soundbackscatteringandnonlinearityparameterB/Atoincrease,buttheattenuationfrequencydependencehardlychanges.Allofthesefindingsareofanimportantrealisticsignifi-cancefordevelopingultrasonicmedicine.

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简介：Inthispaper,atwo-dimensionalprimitiveequationmodel,couplingdynamical,radiativeandphotochemicalprocesses,isusedtosimulatethequasi-biennialoscillation(QBO)inozone.TheQBOintotalozonehasbeensuccessfullysimulatedwhentheforcingofequatorialstratosphericQBOinzonalwindisimposed.ThesimulatedcharactersofQBOinozoneareincloseagreementwiththoseobserved.WefurtheranalyzedthemechanismofformationandmaintenanceofQBOinozone.InthedifferentphasesofQBOinequatorialstratosphericwindfield,theglobalcirculationhassogreatdifferencethatitmakestheeffectsofadvectiontransferandeddytransferpresentaquasi-biennialperiodicalvariation.Chemicaleffectanddynamicaleffectarebasicallyout-of-phase.TheytogetherformandmaintaintheQBOinozone.Totalvariationrateisatinydifferenceofthetwolargeamounts.Atthelowerlevelofmiddle-highlatitudes,however,ithasaphasedifferenceofabout1-2monthsbetweendynamicalandnegativechemicaleffects,wherethedynamicaleffectiscomparativelygreater.QBOinozonehasnoclearcountereffectsonatmosphericcirculation.TheexperimentresultsshowthattheeffectsofQBOinozoneontemperaturefieldandwindfieldareverysmall.

简介：AbstractObjective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter, population-based retrospective cohort study. Longitudinal ultrasound measurement data were collected from 24 hospitals in 18 provinces of China from 1st September through 31st October of 2019. The estimated fetal weight (EFW) was calculated based on head circumference, abdominal circumference, and femur length using Hadlock formula 3. Fetal growth curves were estimated using a two-level linear regression model with cubic splines. All participants were divided into two groups: the northern group (n = 5829) and the southern group (n = 3246) based on the geographical division of China and male fetus group (n = 4775) and female fetus group (n = 4300) based on fetal gender. The EFW was compared by fetal gender and geographical group. All statistical models were adjusted for maternal sociodemographic characteristics.Results:A total of 9075 participants with 31,700 ultrasound measurement records were included in this study. Male fetuses demonstrated significantly larger EFW compared to female ones starting at 16 weeks of gestation and extending to delivery (global test P < 0.01). The overall geographic difference in EFW was significant (global test P = 0.03), and week-specific comparisons showed that the northern group had a greater EFW starting at 15 weeks of gestation and extending to 29 weeks of gestation, although this difference did not extend to the time of delivery. The Z-score of EFW confirmed that our Chinese fetal growth charts differed from previously published standards.Conclusion:This study provides EFW and ultrasound biometric reference measurements for Chinese fetuses and reveals differences from other fetal growth charts. The chart is worth promoting in more regions of China but should be tested prudently before use.

简介：Dizzinessaffectsaleutone-thirdofindividualsovertheageof65years,andisoneofthemostconmlonreasonsfortheelderlytoconsulttheirgeneralpractitioner.Syncopeaffectsatleast20%ofthepopulationatmlnetimeandaccountsforabout6%ofgeneralmedicaladmissionsintheUK.Recurrentsymptomsareparticulas-lydisablingbecausetheyaffectanindividual'sabilitytoworkandtodrive,increasesusceptibilitytofallsandassociateinju-rim,andreduceindependenceintheelderly.

简介：Thestabilityofthethinliquidfilminacapillaryisimportanttothephase-changeheattransferprocessinminiatureofmicrostructures.Fromthebasicequationsformotionandheattransferattheinterfaceofthefilm,itsstabilityistheoreticallystudied.Withevaluationoftheeffectsandrelativemagnitudesofvariousdrivingforcesandwiththeuseoflong-wavetheoryinadditiontolinearstabilityanalysis,thecontrollingequationsaresimplifiedandanevolutionequationforthefilm'sthicknessisobtained.Detailedanalysisontheevolutionequationshowsthatinstabilityoccursfirstinthemeniscusregionandtheinstabilityconditionvarieswithboundaryconditions,geometricalscalesandthermalproperties.Thenumericalresultsagreewellwithearlieroneswithsomefavorableextensionsandimprovements.

简介：由测试melt索引(MI)，张力的力量；碎延期比率，polyoxymethylene(POM)的热变老率被分析；比较。表面形态学；POM表面的功能组的类型被观察；由SEM分析了；XPS。结果证明MI在120°C与变老的时间逐渐地珍视增加，显示热氧化分解occurrs慢慢地。在张力的力量上的20天的热变老的效果；打破POM的延期比率不是明显的，证明变老POM是相当一个长过程。在以后105天，裂开的热变老；POM表面上的搽粉的occurr。XPS决心以前显示出样品的C1s系列；在变老以后，包括C-C的二座山峰；公司，当在变老以后C-C的内容减少时；公司的内容增加，显示POM的热变老主要是碎；C-C债券分解。原来的样品的O1s/C1s比率是56.98%；在105天的热变老以后，比率是72.92%。

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简介：ThisletterintroducescolorconstancyandRetinextheoryforimageenhancement.Itclas-sifiesRetinexalgorithmsintofourcategoriesandprovidestheirprinciplesandimplementationsingeneral.TheexperimentalresultsofFrankle-McCann,MSR(Multi-ScaleRetinex)andPNSD(Pro-jectedNormalizedSteepestDescent)Retinexalgorithmsarepresentedandcompared.Moreover,varianceandaveragegradientareproposedtoevaluatetheperformanceofthedifferentalgorithms.

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简介：Toinvestigatethefeasibilityforahelicallinetobeusedasapulseformingline(PFL),thetransmissioncharacteristicsofthehelicaltransmissionlineisstudiedboththeoreticallyandexperimentally.Theresultsindicatethatitisfeasibletoemployahelicallineasalong-pulsePFL,andtheinfluenceofitsdispersionisnegligible.ComparedwithaconventionalcoaxialPFL,thehelicalPFLwiththesamesizecanproducealongerpulse.

简介：Hydrodynamiccharactersonahorizontal,thin,rigidplatelocatedbeneaththefreesurfacearenumericallyinvestigated.Assumingalinear,time-harmonicpotentialflowandutilizingGreenidentity,thegoverningLaplaceequationcanbesimplifiedintoFredholmintegralequationofthesecondkind.Supposinglinear-orderdiscontinuouselementsalongintersectingverticalboundaries,andbyuseoftheboundaryelementmethod,numericalsolutionaboutsourcestrengthdistributionontheplatecanbechangedintoaseriesofalgebraicequations.The3DGreenfunctionisintroducedtosetuptheintegralequations,andtheGMRESsolverisperformedforsolvingthelargedenselinearsystemofequations.Theadded-mass,dampingforceandexcitingforceareevaluateddirectlyfromtheequations.Itisfoundthattheadded-masscoefficientbecomesnegativeforarangeoffrequencieswhentheplateissufficientlyclosetothefreesurface.

简介：Thesurfacecoatingofgrindingballswasinvestigatedexperimentally.TheresultsshowthatacoatingmayformonthesurfaceofgrindingballswhenCrorAlpowdersaresubjectedtoballgrinding.Theplasticdeformationoftheballsurfaceplaysanimportantroleduringthecoatingformation,andthestrongbindingforcebetweenthepowdersandtheballsisanecessarypre-condition.Thethicknessofcoatingincreaseswiththeplasticityofthepowdersandtheballs.Annealingtheballswithcoatingwillresultinanobviousdiffusionoftheelementsinthebondingzoneofinter-face.

简介：Densityfunctionaltheory(DFT)calculationswerecarriedoutonthecompoundsCp2Ln-guanforLn=Y,Lu,Yb,DyandGd,[guan=(iPrN)2CN(iPr)2].TheresultswerecomparedwiththeX-raystructuresthatwereavailablefromtheliterature;thecalculationsreproducedquitewelltheexperimentalstructuralfeaturesinthesecomplexesexhibitingdistortedtetrahedrongeometry.ThecalculatedevolutionoftheLn-guanbondasafunctionofthecationshowedthatlanthanide-liganddistancesincreasedwiththeincrea...

简介：Ultrasonicattenuationinliquidhydrogenhasbeenmessuredwiththepulse-echotechniqueasafunctionoftemperaturefrom13.84Kto20.50K,at45MHz.Theresultsindicatethatthetemperaturedependenceofultrasonicattenuationinliquidhydrogenismainlydeterminedbyvolumeviscosityeffect.Ultrasonicattenuatinduetovolumeviscosityisgettingmoreandmorewithcooling.Theratiobetweenvolumeviscouscoefficientandshearviscouscoefficientisfrom1.4to4.2withinthemeasuredtempera-tureregion.

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简介：ByapplyinganewvortexdetectionmethodtotheECMWF40-yrreanalysis(ERA40)datafrom1985to2002,theclimatologyofsummervorticeshasbeeninvestigatedinfivesubtropicalregions,i.e.,thenorthwesternPacific,northeasternPacific,northwesternAtlantic,northeasternAtlantic,andAustralia-SouthPacific,followedbyvalidationwithNCEP/NCARreanalysisdata.Resultsareasfollows:(1)ThespatialdistributionsofERA40vortexactivities(VAC)werewellconsistentwiththoseofNCEP/NCARreanalysis(NRA)resultsinallregions,especiallyinnorthwesternPacific.(2)Becauseofdifferentmodelresolutions,boththenumberandintensityofvorticesobtainedfromNRAweresignificantlyweakerthanERA40's.(3)Vorticesmainlycruisedincoastsandtheadjacentseas,fromwheretothelandortheopenseavortexactivitiesweregraduallydecreased.(4)ThereweretwoactivecentersinthenorthwesternPacific:onewaslocatedinSouthChinaSeaandtheother,asthelargestcenterofthefiveregions,spreadfromtheeastsideofthePhilippinestoJapan.(5)OverthenorthwesternAtlantic,mostvorticesoccurredinPanamaanditswest-sideoffshore.(6)ThespatialdistributionsofvorticeswerealikebetweenthenortheasternPacificandnortheasternAtlantic,bothspreadingfromcoaststothewest-sideseaat5°-20°N.(7)IntheAustralia-SouthPacific,vorticeswerenotasactiveasthoseintheotherfourregions,andmostlytookplaceintheequator-sideofnearoceanareas.(8)ExceptthenorthwesternPacificandnorthwesternAtlantic,theVACinterannualvariationsintheotherthreeregionsweredifferentbetweenERA40andNRAdata.(9)InthenorthwesternPacificandnorthwesternAtlantic,theVACinterannualvariationcouldbeseparatedtoseveraldistinctstages.(10)Sincethemid1980s,meanvortexintensitywasgettingincreasedinthenorthwesternPacific,whichwasmostsignificantinthesubtropicalareasonaglobalbasis.InthewesternNorthAtlantic,therewasadecreasing(increasing)trendofthemeanvortexintensitybefo