简介：AbstractBackground:Fetal weight is an important parameter to ensure maternal and child safety. The purpose of this study was to use three-dimensional (3D) limb volume ultrasound combined with fetal abdominal circumference (AC) measurement to establish a model to predict fetal weight and evaluate its efficiency.Methods:A total of 211 participants with single pregnancy (28-42 weeks) were selected between September 2017 and December 2018 in the Beijing Obstetrics and Gynecology Hospital of Capital Medical University. The upper arm (AVol)/thigh volume (TVol) of fetuses was measured by the 3D limb volume technique. Fetal AC was measured by two-dimensional ultrasound. Nine cases were excluded due to incomplete information or the interval between examination and delivery >7 days. The enrolled 202 participants were divided into a model group (134 cases, 70%) and a verification group (68 cases, 30%) by mechanical sampling method. The linear relationship between limb volume and fetal weight was evaluated using Pearson Chi-squared test. The prediction model formula was established by multivariate regression with data from the model group. Accuracy of the model formula was evaluated with verification group data and compared with traditional formulas (Hadlock, Lee2009, and INTERGROWTH-21st) by paired t-test and residual analysis. Receiver operating characteristic curves were generated to predict macrosomia.Results:AC, AVol, and TVol were linearly related to fetal weight. Pearson correlation coefficient was 0.866, 0.862, and 0.910, respectively. The prediction model based on AVol/TVol and AC was established as follows: Y=-481.965+ 12.194TVol + 15.358AVol + 67.998AC, R2adj = 0.868. The scatter plot showed that when birth weight fluctuated by 5% (i.e., 95% to 105%), the difference between the predicted fetal weight by the model and the actual weight was small. A paired t-test showed that there was no significant difference between the predicted fetal weight and the actual birth weight (t= -1.015, P = 0.314). Moreover, the residual analysis showed that the model formula’s prediction efficiency was better than the traditional formulas with a mean residual of 35,360.170. The combined model of AVol/TVol and AC was superior to the Lee2009 and INTERGROWTH-21st formulas in the diagnosis of macrosomia. Its predictive sensitivity and specificity were 87.5% and 91.7%, respectively.Conclusion:Fetal weight prediction model established by semi-automatic 3D limb volume combined with AC is of high accuracy, sensitivity, and specificity. The prediction model formula shows higher predictive efficiency, especially for the diagnosis of macrosomia.Trial Registration:ClinicalTrials.gov, NCT03002246; https://clinicaltrials.gov/ct2/show/NCT03002246?recrs=e&cond=fetal& draw=8&rank=67.

简介：在tetrahydrofuran(THF)的生活cationic戒指洞聚合期间的单体集中的方便即时监视与甲基triflate(MeOTf)开始了的A为平衡单体集中的运动调查和决心被开发了([M]e)经由在在联合的situFTIR光谱学与一颗钻石付小费给的稀释全部的反射(ATR)沉浸探查。聚合率从ln的线性斜坡是关于单体集中和开始者集中的第一份订单([M]<潜水艇class=“a-plus-plus”>0-[M]e)/([M]-[M]在在各种各样的溶剂的不同温度的e)对聚合时间。[M]<潜水艇class=“a-plus-plus”>当与增加聚合温度指数地增加了时，e与起始的单体集中线性地减少了。平衡强烈也取决于有单体的溶剂极性和它的相互作用。平衡聚合时间(t<潜水艇class=“a-plus-plus”>e)与增加溶剂极性减少了并且与增加线性地减少了[M]<潜水艇class=“a-plus-plus”>在有到当溶剂不在时的体积聚合的一样的点的不同斜坡的三溶剂的0。M的方程n，e=72.1/(0.14-0.04[M]e)被建立了为数字一般水准为预言提供一条简单、有效的途径以平衡状态的polyTHFs的分子的重量(Mn，在在0o犀?犀?犈?犈的THF的平衡生活cationic戒指洞聚合的e)？？

简介：Inthispaperthegeneralizedweightisintroduced,anditsbehaviourisdiscussed.

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.

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简介：AbstractThe obstetric issues and management styles in China are different from that in Western countries. Chinese medical education, residency training, obstetric care structure, and management of common obstetric complications are briefly reviewed and compared to the United States. Maternal-fetal medicine (MFM) is rapidly developing in China, but the development of MFM may not follow the same trajectory as in the West. Understanding the difference between China and the West may facilitate communication and foster mutual development.

简介：AbstractThis paper provides ethical guidance for the professionally responsible clinical investigation of maternal-fetal investigation for fetal or neonatal benefit and its transition into clinical practice. We present an ethical framework based on the ethical principles of beneficence, respect for autonomy, and justice, the professional virtue of integrity, and the ethical concept of the fetus as a patient. We identify the implications of this ethical framework for the qualifications that centers for maternal-fetal intervention should satisfy. These centers have the ethical obligation to provide prospective review and oversight of both innovation (an experiment undertaken to benefit an individual patient) and research (an experiment undertaken to create generalizable knowledge). We describe ethically justified criteria for innovation and early-phase research, for randomized clinical trials, and for the responsible transition into clinical practice. We also identify the elements of the informed consent process, including measures to prevent therapeutic misconception by pregnant patients during the informed consent process. The scientific, clinical, and ethical requirements of maternal-fetal investigation are demanding. However, the commitment to safety and quality requires that they be met. Fulfilling this commitment will result in well-documented professionally responsible investigation of maternal-fetal intervention for fetal and neonatal benefit.

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简介：AbstractFetal growth restriction (FGR) has a prevalence of about 10% worldwide and is associated with an increased risk of perinatal mortality and morbidity. FGR is commonly caused by placental insufficiency and can begin early (<32 weeks) or in late (≥32 weeks) gestational age. A false positive antenatal diagnosis may lead to unnecessary monitoring and interventions, as well as cause maternal anxiety. Whereas a false negative diagnosis exposes the fetus to an increased risk of stillbirth and renders the pregnancy ineligible from the appropriate care and potential treatments. The clinical management of FGR pregnancies faces a complex challenge of deciding on the optimal timing of delivery as currently the main solution is to deliver the baby early, but iatrogenic preterm delivery of infants is associated with adverse short-and long-term outcomes. Early and accurate diagnosis of FGR could aid in better stratification of clinical management, and the development and implementation of treatment options, ultimately benefiting clinical care and potentially improving both short-and long-term health outcomes. The aim of this review is to present the new insights on biomarkers of placenta insufficiency, including their current and potential value of biomarkers in the prediction and prevention for FGR, and highlight the association between biomarkers and adverse outcomes in utero to explore the specific mechanism of impaired fetal growth that establish the basis for disease later in life.

简介：AbstractFetal growth restriction (FGR) is associated with multiple adverse perinatal outcomes, such as increased risk of intrauterine death, neonatal morbidity and mortality, and long-term adverse outcomes. Genetic etiological factors are critical in fetuses with intrauterine growth restriction, including chromosomal abnormalities, copy number variants, single gene disorders, uniparental disomy, epigenetic changes, and confined placental mosaicism. This paper aims to provide an overview of genetic defects related to FGR and to highlight the importance of prenatal genetic counseling and testing for precise diagnosis and management of FGR.

简介：AbstractFetal growth restriction (FGR) is the condition in which a fetus does not reach its intrinsic growth potential and in which the shortterm and long-term risks of severe complications are increased. FGR is a frequent complication of pregnancy with a complex etiology and limited management options, other than timely delivery. The most common pathophysiological mechanism is placental insufficiency, due to many underlying causes such as maternal vascular malperfusion, fetal vascular malperfusion and villitis.Identifying truly growth restricted fetuses remains challenging. To date, FGR is often defined by a cut-off of the estimated fetal weight below a certain percentile on a population-based standard. However, small fetal size as a single marker does not discriminate adequately between fetuses or newborns that are constitutionally small but healthy and fetuses or newborns that are growth restricted and thus at risk for adverse outcomes. In 2016, the consensus definition of FGR was internationally accepted to better pinpoint the FGR population.In this review we will discuss the contemporary diagnosis and management issues. Different diagnostic markers are considered, like Doppler measurements, estimated fetal growth, interval growth, fetal movements, biomarkers, and placental markers.

简介：obtainaninitialoverviewofgenediversityandexpressionpatterninporcinethymus,11,712ESTs(ExpressedSequenceTags)from100-day-oldporcinethymus(FTY)weresequencedand7,071cleanedESTswereusedforgeneexpressionanalysis.ClusteredbythePHRAPprogram,959contigsand3,074singletswereobtained.Blastsearchshowedthat806contigsand1,669singlets(totally5,442ESTs)hadhomologuesinGenBankand1,629ESTswerenovel.AccordingtotheGeneOntologyclassification,36.99%ESTswerecatalogedintothegeneexpressiongroup,indicatingthatalthoughthefunctionalgene(18.78%indefensegroup)ofthymusisexpressedinacertaindegree,the100-day-oldporcinethymusstillexistsinadevelopmentalstage.Comparativeanalysisshowedthatthegeneexpressionpatternofthe100-day-oldporcinethymusissimilartothatofthehumaninfantthymus.

简介：Canearthquakesbepredicted?Howshouldpeopleovercomethedifficultiesencounteredinthestudyofearthquakeprediction?Thisissuecantakeinspirationfromtheexperiencesofweatherforecast.Althoughweatherforecastingtookaperiodofabouthalfacenturytoadvancefromempiricaltonumericalforecast,ithasachievedsignificantsuccess.AconsensushasbeenreachedamongtheChineseseismologicalcommunitythatearthquakepredictionmustalsodevelopfromempiricalforecastingtophysicalprediction.However,itisseldommentionedthatphysicalpredictionischaracterizedbyquantitativelynumericalpredictionsbasedonphysicallaws.Thisarticlediscussesfivekeycomponentsfornumericalearthquakepredictionandtheircurrentstatus.Weconcludethatnumericalearthquakepredictionshouldnowbeputontheplanningagendaanditsroadmapdesigned,seismicstationsshouldbedeployedandobservationsmadeaccordingtotheneedsofnumericalprediction,andtheoreticalresearchshouldbecarriedout.

简介：Inthispaper,weconsiderthenonsymmetricalhalf-planeprediction.Apredictiontheoreticproofofthefundamentalformulaaboutonesteppredictionerrorisgiven.AWold-typedecompositionanditsspectralrepresentationtheoremareproved.Spectralextractionproblemsofthehalf-planeinnova-tionsanditssingularcomponentsareinvestigated.

简介：Samplesofpolyphenylsilsisquioxane（PPSQ）usingCaF2orMgF2asthemaincatalystshadbeenpreparedunderdifferentpolymerizationconditions.TheresultsweretreatedonanorthogonaldesignL9（34）.Allweight-averagemolecularweights（MW）ofPPSQhadbeenmeasuredbygelpermeationchromatography（GPC）.Effectsofpolymerizationconditionsincludingreactiontemperature,compositionofthedualcatalysts（CaF2orMgF2andDCC）,mixtureofsolventsandreactiontimeonMWofPPSQhavebeendiscussed.ThequantityofthecatalystsisthemostimportantfactorthataffectsMWofPPSQ.Reactiontemperatureisthesecondimportantfactor.AppropriatepolymerizationconditionhasbeenestablishedtogetPPSQwithhighMW.

简介：Thispaperproposesanovelexemplar-basedmethodforreducingnoiseincomputedtomography(CT)images.Intheproposedmethod,denoisingisperformedoneachblockwiththehelpofagivendatabaseofstandardimageblocks.Foreachnoisyblock,itsdenoisedversionisthebestsparsepositivelinearcombinationoftheblocksinthedatabase.Weformulatetheproblemasaconstrainedoptimizationproblemsuchthatthesolutionisthedenoisedblock.Experimentalresultsdemonstratethegoodperformanceoftheproposedmethodovercurrentstate-of-the-artdenoisingmethods,intermsofbothobjectiveandsubjectiveevaluations.

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简介：Anumericalsolutionoftheweightfunctionforatwo-electrodeelectromagneticflowmeterwasproposed.Thesolutionwasobtainedbyusingthefiniteelementmethodbasedonthebasicequationofatraditionaltwo-electrodeelectromagneticflowmeter.Thetwo-dimensionaldistributionoftheweightfunctionoftheelectromagneticflowmeterobtainedwasverifiedbytheanalyticalsolution.Three-dimensionaldistributionoftheweightfunctionwasalsopresentedinthepaper.Itcanbeemployedtoanalyzethesensitivityandlinearityoftheelectromagneticflowmeterwithnon-uniformmagneticfield,andeventoassistthedesignoftheexcitationcoilpair.

简介：AbstractGamete production is essential for mammalian reproduction. In the ovaries, the primordial follicle, which is the basic reproductive unit, is formed either perinatally or during the second pregnancy stage in humans. However, some oocytes die before the establishment of the primordial follicle pool. Consequently, it is essential to uncover how the size of the primordial follicle pool is determined and how the programmed cell death of oocytes is performed under potential surveillance. According to recent studies, the fate of oocytes in the fetal ovary seems to be determined by different protective strategies through the timely control of apoptosis or autophagy. In this review, we discuss at least three oocyte-derived protective biomarkers, glycogen synthase kinase 3 beta, X-linked inhibitor of apoptosis, and Lysine-specific demethylase 1 (also known as KDM1A), responsible for surveilling the developmental quality of fetal oocytes to coordinate primordial follicle formation in the fetal ovary. This review contributes to a better understanding of the secrets of the female reproductive reserve under physiological conditions.

简介：AbstractSince the 1970s, electronic fetal monitoring (EFM) also known as cardiotocography (CTG) has been used extensively in labor around the world, despite its known failure to help prevent many babies from developing neonatal encephalopathy and cerebral palsy. Part of EFM’s poor performance with respect to these outcomes arises from a fundamental misunderstanding of the differences between screening and diagnostic tests, subjective classifications of fetal heart rate (FHR) patterns that lead to large inter-observer variability in its interpretation, failure to appreciate early stages of fetal compromise, and poor statistical modeling for its use as a screening test. We have developed a new approach to the practice and interpretation of EFM called the fetal reserve index (FRI) which does the following: (1) breaking FHR components down into 4 components, (heart rate, variability, accelerations, and decelerations); (2) contextualizing the metrics by adding increased uterine activity; (3) adding specific maternal, fetal, and obstetric risk factors. The result is an eight-point scoring metric that, when directly compared with current American College of Obstetricians and Gynecologists EFM categories, even in version 1.0 with equal weighting of variables, shows that the FRI has performed much better for identifying cases at risk before damage had occurred, reducing the need for emergency deliveries, and lowering overall Cesarean delivery rates. With increased data, we expect further refinements in the specifics of scoring that will allow even earlier detection of compromise in labor.