Manipulating Crystal Growth and Secondary Phase PbI_(2)to Enable Efficient and Stable Perovskite Solar Cells with Natural Additives

In perovskite solar cells(PSCs),the inherent defects of perovskite film and the random distribution of excess lead iodide(PbI_(2))prevent the improvement of efficiency and stability.Herein,natural cellulose is used as the raw material to design a series of cellulose derivatives for perovskite crystallization engineering.The cationic cellulose derivative C-Im-CN with cyano-imidazolium(Im-CN)cation and chloride anion prominently promotes the crystallization process,grain growth,and directional orientation of perovskite.Meanwhile,excess PbI_(2)is transferred to the surface of perovskite grains or formed plate-like crystallites in local domains.These effects result in suppressing defect formation,decreasing grain boundaries,enhancing carrier extraction,inhibiting non-radiative recombination,and dramatically prolonging carrier lifetimes.Thus,the PSCs exhibit a high power conversion efficiency of 24.71%.Moreover,C-Im-CN has multiple interaction sites and polymer skeleton,so the unencapsulated PSCs maintain above 91.3%of their initial efficiencies after 3000 h of continuous operation in a conventional air atmosphere and have good stability under high humidity conditions.The utilization of biopolymers with excellent structure-designability to manage the perovskite opens a state-of-the-art avenue for manufacturing and improving PSCs.

用于电热转换、电磁屏蔽的导电陶瓷的简易大规模制备

通过传统瓷砖制备工艺的干压法,制备了一种碳化酚醛树脂基导电陶瓷复合材料(CCC)。首先,将导电前驱体溶液(酚醛树脂)与陶瓷前驱体均匀混合,随后在单次热处理中同时实现了碳化和陶瓷化。碳化后的材料赋予复合材料出色的电导率和可靠的循环加热特性。在12 V电压下通电10 min后材料表面温度可达386℃,在20 V电压下达到400℃仅需48 s。红外热像图表明,热量在复合材料表明分布均匀,并且可以通过更改电路布置(串联或并联)来调节电热转换性能。此外,与普通陶瓷相比,导电陶瓷复合材料在8.2 GHz下表现出了26.2 dB的优异电磁屏蔽性能,并提升了光热转换性能。更重要的是,这种单次热处理加热生产导电陶瓷复合材料的方法成本较低,可在原有瓷砖生产线的基础上进行大规模生产。出色的电学性能促进了该陶瓷复合材料在焦耳加热中的应用(如除冰、烧水和烹饪)及电磁屏蔽领域的应用。

^(18)F-FDG PET/CT 相关参数与胃癌患者HER2表达状态的相关性研究

目的:探讨18F-FDG PET/CT相关参数对预测胃癌患者HER2表达状态的价值。方法:回顾性分析2000年1月至2020年3月河北医科大学第四医院115例经手术病理证实的胃癌患者临床资料,且术前均行PET/CT检查,分析胃癌原发病灶的最大标准化摄取值(maximum standard uptake value,SUVmax)、肿瘤代谢体积(metabolic tumor volume,MTV)和总糖酵解量(tumor lesion gly⁃colysis,TLG)以及HER2的表达状态,采用单因素和多元Logistic回归分析的方法,评价PET/CT各参数与HER2表达的相关性。结果:HER2表达阳性17例,阴性98例。SUVmax、MTV及TLG在HER2表达阳性与阴性者之间无显著性差异(P>0.05)。但是在排除印戒细胞癌后(n=105),MTV和TLG在HER2阳性胃癌患者中明显低于HER2阴性者[四分位数12.6(8.4,18.7)vs.23.7(14.4,32.9),P=0.002;35.3(20.8,68.1)vs.69.9(44.2,173.3),P<0.001]。MTV及TLG的最佳界值分别为24.3 cm3、35.9 g时,其预测HER2表达阳性的准确率分别为57.1%和80.9%。单因素分析显示肿瘤分化程度、病理分型、MTV及TLG与HER2表达相关,多元Logis⁃tic回归分析显示肠型(OR=6.804,P=0.009)、TLG≤35.9 g(OR=4.600,P=0.029)是预测HER2表达的指标。结论:TLG可以预测非印戒细胞胃癌患者HER2表达,用以指导治疗方案的选择。

Trends in geographical disparities for cervical cancer mortality in China from 1973 to 2013:a subnational spatio-temporal study

Objective： This study was designed to explore the time trends in geographical variations of cervical cancer mortality in China's Mainland over the period 1973 to 2013, to provide subnational spatio-temporal patterns for targeted promotion of human papillomavirus vaccine in China. Methods： Data were extracted from three national retrospective death surveys and cancer registry. The rate ratio （RR） was estimated for the aggregated data for seven geographical regions using generalized linear models to evaluate time trends in geographical disparities of cervical cancer mortality. Results： There was a significant decrease in cervical cancer mortality in China from 1973-1975 to 2004-2005, but leveled off thereafter to 2011-2013. Compared to the period 1973-1975 the RR for the three last time periods were 0.33 [95% confidence interval （95% CI）： 0.30-0.37] for 1990-1992, 0.21 （95% CI： 0.19-0.24） for 2004-2005 and 0.24 （95% CI： 0.22-0.26） for 2011-2013. Females living in the Northwest China and Central China have a high risk of mortality from cervical cancer compared to the nationwide, with the RR being 2.09 （95% CI： 1.83-2.38） and 1.26 （95% CI： t.11-1.44） respectively, while the RRs for South China, Northeast China and Southwest China were below 1.00, indicating the lower death risk. Despite the mortality rate had increased slightly from 2004 to 2013, there was an encouraging sign that the geographical disparities in cervical cancer mortality had gradually narrowed over time across China. Conclusions： Although cervical cancer mortality in China has reduced to very low levels, the high risk of cervical cancer in Northwest China and Central China is still noteworthy. Public health policies including the promotion of vaccine should be targeted to further reduction of geographical disparities in cervical cancer mortality.

Rapid estimation of soil heavy metal nickel content based on optimized screening of near-infrared spectral bands

In near-infrared spectroscopy,the traditional feature band extraction method has certain limitations.Therefore,a band extraction method named the three-step extraction method was proposed.This method combines characteristic absorption bands and correlation coefficients to select characteristic bands corresponding to various spectral forms and then uses stepwise regression to eliminate meaningless variables.Partial least squares regression(PLSR)and extreme learning machine(ELM)models were used to verify the effect of the band extraction method.Results show that the differential transformation of the spectrum can effectively improve the correlation between the spectrum and nickel(Ni)content.Most correlation coefficients were above 0.7 and approximately 20%higher than those of other transformation methods.The model effect established by the feature variable selection method based on comprehensive spectral transformation is only slightly affected by the spectral transformation form.Infive types of spectral transformation,the RPD values of the proposed method were all within the same level.The RPD values of the PLSR model were concentrated between 1.6 and 1.8,and those of the ELM model were between 2.5 and2.9,indicating that this method is beneficial for extracting more complete spectral features.The combination of the three-step extraction method and ELM algorithm can effectively retain important bands associated with the Ni content of the soil.The model based on the spectral band selected by the three-step extraction method has better prediction ability than the other models.The ELM model of the first-order differential transformation has the best prediction accuracy(RP^2=0.923,RPD=3.634).The research results provide some technical support for monitoring heavy metal content spectrum in local soils.

A novel demodulation method for transmission using nitrogen–vacancy-based solid-state quantum sensor

Diamond based quantum sensing is a fast-emerging field with both scientific and technological significance.The nitrogen–vacancy(NV)center,a crystal defect in diamond,has become a unique object for microwave sensing applications due to its excellent stability,long spin coherence time,and optical properties at ambient condition.In this work,we use diamond NV center as atomic receiver to demodulate on–off keying(OOK)signal transmitted in broad frequency range(2 GHz–14 GHz in a portable benchtop setup).We proposed a unique algorithm of voltage discrimination and demonstrated audio signal transceiving with fidelity above 99%.This diamond receiver is attached to the end of a tapered fiber,having all optic nature,which will find important applications in data transmission tasks under extreme conditions such as strong electromagnetic interference,high temperatures,and high corrosion.

Elucidation of the hepatoprotective effect and mechanism of Melastoma dodecandrum Lour. based on network pharmacology and experimental validation

Objective:To systematically explore the effect and mechanism of melastomatis dodecandri herba(Melastoma dodecandrum Lour.)in the treatment of hepatitis based on network pharmacology.Method:We evaluated the hepatoprotective effects of M.dodecandrum in concanavalin A(Con A)-induced hepatitis in mice by assessing survival rate,histological analysis,serum transaminases,and related cytokines.Then the mechanism of action was predicted by a network pharmacology-based strategy.Based on the results,we measured the hepatic expression of related genes at mRNA level and proteins related to the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)and nuclear factorkappa B(NF-кB)pathways.Results:Our study results clearly demonstrated that M.dodecandrum pretreatment significantly alleviated liver injury.This was demonstrated by an increase in survival rate,decreased severity of liver damage,and reduced serum transaminase levels compared with those in the Con A group.Moreover,M.dodecandrum significantly reduced the serum levels of tumor necrosis factor-a,interleukin-6,and interferon-g and increased the liver levels of superoxide dismutase,which indicated that M.dodecandrum exhibits anti-inflammatory and antioxidant activities.On the basis of network pharmacology,50 nodes were selected as major hubs based on their topological importance.Pathway enrichment analyses indicated that the putative targets of M.dodecandrum mostly participate in various pathways associated with the anti-inflammation response,which implies the underlying mechanism by which M.dodecandrum acts on hepatitis.Real-time fluorescent quantitative PCR analysis showed that M.dodecandrum downregulates the mRNA expression of interleukin-6,Toll-like receptor 7,interleukin-1 receptor-associated kinase-4,NF-кB and tumor necrosis factor-a in liver tissues.Western blotting showed that M.dodecandrum pretreatment protected against inflammation through activating the PI3K-Akt pathway by upregulating phosphorylated Akt(p-Akt)expression and suppressing NF-кB activation by inhibiting the phosphorylation of IKK,IkBa,and p65.Conclusion:The present work demonstrated the hepatoprotective effects of M.dodecandrum by regulating the PI3K/Akt and NF-кB pathways in Con A-induced mice,which provide insights into the treatment of hepatitis using M.dodecandrum.

The relevance study of effective information between near infrared spectroscopy and chondroitin sulfate in ethanol precipitation process

Near infrared spectroscopy(NIRS)is based on molecular overtone and combination vibrations.It is difficult to assign specific features under complicated system.So it is necessary to find the relevance between NIRS and target compound.For this purpose,the chondroitin sulfate(CS)ethanol precipitation process was selected as the research model,and 90 samples of 5 different batches were collected and the content of CS was determined by modifed carbazole method.The relevance between NIRS and CS was studied throughout optical pathlength,pretreat ment methods and variables selection methods.In conclusion,the first derivative with Savitzky--Golay(SG)smoothing was selected as the best pretreatment,and the best spectral region was selected using interval partial least squares(iPLS)method under 1 mm optical cell.A multivariate cali-bration model was established using PLS algorithm for determining the content of CS,and the root mean square error of prediction(RMSEP)is 3.934gL-1.This method will have great potential in process analytical technology in the future.

Hyperspectral estimation model of soil Pb content and its applicability in different soil types

In order to obtain Pb content in soil quickly and efficiently,a multivariate linear regression(MLR) and a principal component regression(PCR) Pb content estimation model were established on the basis of hyperspectral techniques,and their applicability in different soil types was evaluated.Results indicated that Pb exhibited strong spatial heterogeneity in the study area,and more than 82% of the samples exceeded the background value.In addition,the pollution range was large.Pb was sensitive in the nearinfrared band,and the correlation of absorbance(AB) was most significant of all the transformed forms.Both models achieved optimal stability and reliability when AB was used as an independent variable.Compared with the PCR model,the stability,fitting accuracy,and predictive power of the MLR model were superior with a coefficient of determination,root mean square error,and mean relative error of 0.724%,24.92%,and 28.22%,respectively.Both models could be applied to different soil types;however,MLR had better applicability compared with PCR.The PCR model that distinguished different soil types had better reliability than one that did not.Thus,the model established via hyperspectral techniques can achieve largearea,rapid,and efficient soil Pb content monitoring,which can provide technical support for the treatment of heavy metal pollution in soil.

C14-HSL limits the mycelial morphology of pathogen Trichosporon cells but enhances their aggregation:Mechanisms and implications

The biosecurity hazards caused by pathogenic fungus have been widely concerned.Given the long-term coexistence of eukaryotic pathogens and quorum sensing bacteria in different habitats in environments,we hypothesized that they have social interactions via signal molecules.In this work,we firstly discovered the well-known bacterial signal molecules play an adverse role in the cell morphology and metabolism in a model pathogen Trichosporon asahii.N-Tetradecanoyl-L-homoserine lactone(C14-HSL)was discovered to increase pathogen hazards of T.asahii,which limited mycelium by 52%,but enhanced cell aggregation by 93%.Higher fluorescence intensity of tryptophan(59%)and aromatic protein(2-fold)contents after the treatment of C14-HSL,indicating that aromatic proteins helped aggregate Trichosporon and showed hydrophobicity.Transcriptome analysis revealed that C14-HSL upregulated the shikimate pathway(above1-fold)located in downstream of tricarboxylic acid cycle,which contributed to the synthesis of more aromatic proteins and the formation of larger flocs.The limited mycelial growth of T.asahii attributed to the up-regulated expressions of cell cycle process.The fungal transboundary response to bacterial C14-HSL was controlled by signal transduction pathways.This study provides new insights into the co-evolution of bacterial and pathogenic fungi in microecosystems.

The main and added effects of heat on mortality in 33 Chinese cities from 2007 to 2013

Increases in ambient temperatures and the frequency of extreme heat events constitute important burdens on global public health.However,evidence on their effects on public health is limited and inconclusive in China.In this study,data on daily deaths recorded in 33 Chinese cities from 2007 to 2013 was used to evaluate the effect of heat on mortality in China.In addition to the definition of a heatwave established by the China Meteorological Administration,we combined four city-specific relative thresholds(90th,92.5th,95th,and 97.5th percentiles)of the daily mean temperature during the study period and three durations of≽2,≽3,and≽4 days,from which 13 heatwave definitions were developed.Then,we estimated the main and added effects of heat at the city level using a quasi-Poisson generalized additive model combined with a distributed lag nonlinear model.Next,the estimates for the effects were pooled at the national level using a multivariable meta-analysis.Subgroup analysis was performed according to sex,age,educational attainment,and spatially stratified heterogeneity.The results showed that the mortality risk increased from 22.3%to 37.1%due to the effects of the different heatwave definitions.The added effects were much lower,with the highest increase of 3.9%(95%CI:1.7%–6.1%)in mortality risk.Females,the elderly,populations with low educational levels,and populations living inland in China were found to be the most vulnerable to the detrimental effects of heat.These findings have important implications for the improvement of early warning systems for heatwaves.

黄土高原北部风蚀区防风固沙服务时空分异及驱动因素

黄土高原北部是黄河流域土壤风蚀典型区,评估防风固沙服务对黄河流域生态安全屏障建设具有重要意义。基于京津风沙源治理工程效益评价中的风蚀模型估算黄土高原北部风蚀区固沙量,定量评估2000—2020年防风固沙服务,并结合土地利用、植被覆盖度与气候变化分析其驱动机制。结果表明:(1)2000—2020年黄土高原北部风蚀区年均固沙量5.52亿t,年际变化总体呈减少趋势,平均变化率-0.12 t·hm^(-2)·a^(-1);而防风固沙服务保有率以每年0.50%的速率增加,研究区植被防风固沙服务增强。空间分布上榆林北部风沙区、宁夏东部风沙区、甘肃庆阳、毛乌素沙地中南部及沙地北部达拉特旗植被防风固沙服务有所增强。(2)草地是控制土壤风蚀、发挥防风固沙作用的主要土地利用类型。荒漠化逆转与退耕还草明显增强了防风固沙能力,草地退化将造成固沙服务显著减弱。(3)风速是引起黄土高原北部风蚀区防风固沙服务变化的主要驱动因子,植被恢复对库布齐沙漠和毛乌素沙地等关键区域的防风固沙起到了不可忽视的作用。

Maternal and infant microbiome:next-generation indicators and targets for intergenerational health and nutrition care

Microbes are commonly sensitive to shifts in the physiological and pathological state of their hosts,including mothers and babies.From this perspective,the microbiome may be a good indicator for diseases during pregnancy and has the potential to be used for perinatal health monitoring.This is embodied in the application of microbiome from multi body sites for auxiliary diagnosis,early prediction,prolonged monitoring,and retrospective diagnosis of pregnancy and infant complications,as well as nutrition management and health products developments of mothers and babies.Here we summarized the progress in these areas and explained that the microbiome of different body sites is sensitive to different diseases and their microbial biomarkers may overlap between each other,thus we need to make a diagnosis prudently for those diseases.Based on the microbiome variances and additional anthropometric and physical data,individualized responses of mothers and neonates to meals and probiotics/prebiotics were predictable,which is of importance for precise nutrition and probiotics/prebiotics managements and developments.Although a great deal of encouraging performance was manifested in previous studies,the efficacy could be further improved by combining multi-aspect data such as multi-omics and time series analysis in the future.This review reconceptualizes maternal and infant health from a microbiome perspective,and the knowledge in it may inspire the development of new options for the prevention and treatment of adverse pregnancy outcomes and bring a leap forward in perinatal health care.

Biochar reduces uptake and accumulation of polycyclic aromatic hydrocarbons(PAHs) in winter wheat on a PAH-contaminated soil

For years, biochar has been successfully used for the remediation of polycyclic aromatic hydrocarbons(PAHs) in contaminated soils, not only for improving their removal from soil but also for reducing their uptake by crops. However, the underlying mechanism of biochar application reducing PAH uptake and accumulation in winter wheat remains unclear. Pot trials were conducted on a PAH-contaminated soil amended with bamboo biochar, coconut shell biochar,and maize straw biochar(MSB) for an entire growth period of winter wheat. Compared with no biochar control(CK), application of the three types of biochar significantly(P < 0.01) reduced grain PAH concentration, total equivalent concentration(TEC), and incremental lifetime cancer risk(ILCR), indicating that biochar application, especially MSB, reduced the risk of exposure to PAHs in wheat grain. Furthermore, all three types of biochar significantly(P < 0.05)reduced PAH uptake and accumulation in wheat roots and stems, probably because biochar application enhanced the degradation of PAHs in the rhizosphere soil. Compared with CK, application of the three types of biochar significantly(P < 0.05) reduced the concentration of PAHs in the rhizosphere soil by15.9%–33.7%. It was found that the degradation rate of high-molecular-weight(HMW) PAHs(5-and 6-ring PAHs) was significantly(P < 0.05) higher than that of low-molecular-weight(LMW) PAHs(2–4-ring PAHs) regardless of the type of biochar used. Additionally, all three types of biochar significantly increased the relative abundance of the dominant bacterial phyla and genera in soil. Redundancy and correlation analyses also showed that there was a strong correlation between the removal rate of PAHs and dominant bacteria in the rhizosphere soil. This study indicated that biochar effectively reduced the health risk from dietary exposure to PAHs in wheat grains by increasing the abundance of bacteria related to PAH degradation, promoting the biodegradation of PAHs in the rhizosphere soil, and consequently reducing PAH uptake by wheat.

聚集态分子排列对光电性能的影响

有机小分子材料是由许多分子构成的聚集体,其性能既与单个分子的空间构型和电子特性有关,更与聚集体中分子的排列方式和分子间相互作用密切相关.在有机小分子材料中,聚集体的性质并不是组成它的单分子行为的简单线性叠加,而是经常呈现出聚集态的整体差异性响应特点,即:不同的聚集态分子排列引起截然不同的性能.因此,科学研究已逐渐由单分子研究迈向分子聚集态科学.随着人们对分子聚集态科学的关注,特别是对有机分子固态下的排列和堆积方式、分子间相互作用等方面的深入研究发现,通过不同策略对分子聚集态行为的有效调控,可以实现完全不同于单个分子特性的聚集态发光现象,包括发光强度、颜色、形式以及激发过程的差异.也可以通过分子聚集态的形貌和维度的调节,实现不同光电器件性能的调节和优化.本综述将分别介绍聚集态分子的排列方式对力致变色、室温磷光、力致发光和有机场效应晶体管等方面的重要影响,进一步阐述聚集态分子行为的重要性,同时,为有效调控聚集态分子的排列方式,有针对性地设计和开发优异性能的光电材料提供基础.

输尿管导引鞘在Ⅲ度以上前列腺增生患者输尿管中下段结石清除术中的应用

目的探讨为避免同期或分期先处理前列腺增生,将输尿管导引鞘应用于Ⅲ度以上前列腺增生患者输尿管中下段结石清除术中的安全性和有效性。方法回顾性分析2018年4月至2020年12月于浙江衢化医院采用留置输尿管导引鞘+输尿管硬镜钬激光碎石取石术处理的27例Ⅲ度以上前列腺增生合并输尿管中下段结石患者的临床资料。患者均为男性,年龄(69.7±12.8)岁(范围:55~87岁),经直肠超声测量前列腺体积为(94.8±16.2)cm3(范围:85~186 cm3)。术中先留置输尿管导引鞘,再从导引鞘引入输尿管硬镜,进行钬激光碎石取石术,并记录术中术后并发症。术后1、2个月复查泌尿系X线片或CT尿路造影了解结石残余、输尿管狭窄等情况,评价临床疗效。结果27例患者均顺利一期留置输尿管导引鞘并在输尿管硬镜下行钬激光碎石取石术,术中及术后无输尿管撕脱穿孔、肾周血肿、感染性休克、严重血尿、尿潴留、医源性输尿管狭窄等重大并发症。术后1个月排石率92.6%(25/27),术后2个月排石率为100%(27/27)。2例患者由于术前结石最大径>20 mm,术后存在结石残余,接受体外冲击波碎石;1例结石排出,1例二期输尿管镜下取石。1例患者因输尿管结石息肉包裹较重,术后1个月诊断为输尿管狭窄,术后3个月行腹腔镜下输尿管狭窄段切除+吻合术。结论在Ⅲ度以上前列腺增生患者输尿管中下段结石清除术中,通过先留置输尿管导引鞘,能有效避免术中被迫处理前列腺增生,有助于顺利清除结石。

室温磷光凝胶研究进展

室温磷光(RTP)材料因其独特的发光性质和在光电、传感、生物成像及信息加密等领域广阔的应用前景吸引了研究者的兴趣。近年来,科学家探索了各种方法调控有机分子的室温磷光,并通过磷光分子结构设计以及磷光保护基质的构建成功构筑了长寿命和高量子效率的有机室温磷光材料。超分子凝胶作为诱导室温磷光的新基质,具有三维网络结构、热可逆性质及刺激响应性等优势而引起关注。本综述围绕无金属室温磷光凝胶材料和含金属室温磷光凝胶材料,总结了近年来关于室温磷光凝胶材料的研究现状,并在此基础上,简要展望了室温磷光凝胶材料研究的发展趋势。

牙菌斑生物膜的形成与控制

牙菌斑生物膜是附着于牙釉质表面,由复杂的微生物群落构成的一种聚集体。牙菌斑生物膜的形成与生长对口腔健康有着直接或间接的影响,许多研究证实口腔疾病如龋齿和牙周病都与细菌的积累及牙菌斑的形成有关。在牙菌斑生物膜形态建成过程中,牙齿表面最初的定殖菌对生物膜的微生物组成和结构至关重要,这些初级定殖菌决定了后续与之结合形成共生体的微生物种类和数量。不同的微生物组成可能在与生物膜形成相关的口腔病理状况中发挥不同的作用。因此,本文就牙菌斑生物膜的生长及控制进行综述,介绍其微生物的早期定殖和成熟过程、以及通过物理和化学方法对牙菌斑生物膜的控制,以期为了解牙菌斑生物膜的形成机制及相关口腔疾病的预防和治疗提供有价值的参考。

Variation of the Vaginal Microbiome During and After Pregnancy in Chinese Women

A comprehensive profiling of the vaginal microbial communities and their variability enables an accurate description of the microbiome in women.However,there is a lack of studies available on Chinese women.In the present study,the composition of the vaginal microbiota during pregnancy and the 6-week postpartum period of 454 Chinese women was characterized by sequencing the V3-V4 region of the 16S ribosomal RNA(rRNA)gene.The vaginal microbiome showed variations during pregnancy and the postpartum period based on the abortion history,hypertensive disorders,delivery mode,and maternal age.Co-variation of 22 bacterial taxa,including the Lactobacillus genus and two of its species,may account for the common characteristics of the vaginal microbiome under scenarios of different medical histories and pregnancy outcomes.In contrast,discriminant bacterial species were significantly different between women who had preterm birth(PTB)with and without premature rupture of membranes(PROM),and the community state type(CST)IV-A without any predominant Lactobacillus species in the microbiota was more prevalent during pregnancy in the PROM-PTB cases,suggesting that specific bacterial species could be considered to distinguish between different types of PTB.By providing data on Chinese women,this study will enrich the knowledge of the human microbiome and contribute to a better understanding of the association between the vaginal microbiome and reproductive health.

Splitting positive definite mixed element method for viscoelasticity wave equation

切开积极明确的混合有限元素方法的 A 为秒顺序粘弹性波浪方程被建议。建议过程能被分成三个独立对称的积极明确的 integro 微分的分系统并且不需要解决方程的 a coupled 系统。错误估计为 semidiscrete 和充分分离的计划被导出。为 semidiscrete 计划的存在和唯一被证明。最后，一个数字例子被提供说明方法的效率。