The Analytical Expressions for Computing the Minimum Distance between a Point and a Torus

In this paper, we present the analytical expressions for computing the minimum distance between a point and a torus, which is called the orthogonal projection point problem. If the test point is on the outside of the torus and the test point is at the center axis of the torus, we present that the orthogonal projection point set is a circle perpendicular to the center axis of the torus;if not, the analytical expression for the orthogonal projection point problem is also given. Furthermore, if the test point is in the inside of the torus, we also give the corresponding analytical expression for orthogonal projection point for two cases.

miR-20a-5p调控结核分枝杆菌诱导巨噬细胞凋亡相关基因表达的研究

目的明确小非编码RNA(microRNA,miR-20a-5p)对结核分枝杆菌(MTB)诱导人巨噬细胞凋亡相关基因表达的调控作用。方法构建可表达或抑制miR-20a-5p、转染miR-20a-5p抑制剂(miR-20a-5p-inhibitor,简称“miR-20a-5p-inh”)、作为慢病毒载体的阴性对照(LV1-NC)的慢病毒载体,由oligo-dT引物通过固相亚磷酰胺法合成茎环寡核苷酸,并克隆到含绿色荧光蛋白(GFP)的慢病毒载体pGLV3-GFP内,将构建的miR-20a-5p、miR-20a-5p-inh、LV1-NC转染THP-1人巨噬细胞3h,培养72h后用流式细胞仪分选出GFP+THP-1细胞,并分别采用减毒MTB菌株(H37Ra)感染8h和过氧化氢(H2O2)处理30min 两种方法诱导。通过实时定量PCR技术测定细胞中线粒体相关抗凋亡基因Bcl-2,以及促凋亡基因Bax、Bim和Bad的转录水平。同时,用蛋白免疫印迹法检测细胞裂解物中相关蛋白的表达。结果慢病毒转染细胞后,在无刺激的THP-1细胞中miR-20a-5p的相对荧光强度值为12.21±1.29、miR-20a-5p-inh为9.68±1.38、LV1-NC为10.64±0.96,三者的表达差异均无统计学意义(q=1.815,P=0.385;q=2.072,P=0.602);但在H37Ra和H2O2的刺激后,miR-20a-5p过表达时其相对荧光强度值分别为7.20±0.53、8.55±0.82,明显高于LV1-NC (4.46±0.07、5.49±0.44)(q=50.250,P=0.007;q=1.041,P<0.01),miR-20a-5p受抑制时(1.88±0.08、1.44±0.21)明显低于LV1-NC(q=3.457,P=0.031;q=4.384,P=0.001)。在感染miR-20a-5p慢病毒的THP-1细胞中,H37Ra诱导Bcl-2的表达增加(相对荧光强度值由10.67±0.89增至14.98±0.88)(q=1.064,P=0.008),而感染miR-20a-5p-inh慢病毒时Bcl-2表达减少(由10.67±0.89降至6.49±0.47)(q=3.518,P=0.003);在miR-20a-5p过表达的THP-1细胞中Bim的转录水平减少(由1.22±0.05降至0.98±0.04)(q=1.240,P=0.011),当miR-20a-5p受抑制时Bim的转录水平增加(由1.22±0.05增至1.51±0.08)(q=2.460,P=0.021)。蛋白印迹法检测凋亡相关基因Bcl-2和Bim的蛋白表达水平,结果与基因转录水平相符。结论 miR-20a-5p的表达水平影响MTB诱导的巨噬细胞凋亡相关基因Bcl-2和Bim的表达,并且与促凋亡基因Bim的水平呈负相关,提示miR-20a-5p可能通过调控Bim的表达而影响细胞凋亡。

Insights into triterpene synthesis and unsaturated fatty-acid accumulation provided by chromosomallevel genome analysis of Akebia trifoliata subsp . australis

Akebia trifoliata subsp.australis is a well-known medicinal and potential woody oil plant in China.The limited genetic information available for A.trifoliata subsp.australis has hindered its exploitation.Here,a high-quality chromosomelevel genome sequence of A.trifoliata subsp.australis is reported.The de novo genome assembly of 682.14 Mb was generated with a scaffold N50 of 43.11 Mb.The genome includes 25,598 protein-coding genes,and 71.18%(485.55 Mb)of the assembled sequences were identi fi ed as repetitive sequences.An ongoing massive burst of long terminal repeat(LTR)insertions,which occurred~1.0 million years ago,has contributed a large proportion of LTRs in the genome of A.trifoliata subsp.australis.Phylogenetic analysis shows that A.trifoliata subsp.australis is closely related to Aquilegia coerulea and forms a clade with Papaver somniferum and Nelumbo nucifera,which supports the well-established hypothesis of a close relationship between basal eudicot species.The expansion of UDP-glucoronosyl and UDP-glucosyl transferase gene families and fi-amyrin synthase-like genes and the exclusive contraction of terpene synthase gene families may be responsible for the abundant oleanane-type triterpenoids in A.trifoliata subsp.australis.Furthermore,the acyl-ACP desaturase gene family,including 12 stearoyl-acyl-carrier protein desaturase(SAD)genes,has expanded exclusively.A combined transcriptome and fatty-acid analysis of seeds at fi ve developmental stages revealed that homologs of SADs,acyl-lipid desaturase omega fatty acid desaturases(FADs),and oleosins were highly expressed,consistent with the rapid increase in the content of fatty acids,especially unsaturated fatty acids.The genomic sequences of A.trifoliata subsp.australis will be a valuable resource for comparative genomic analyses and molecular breeding.

Spatial distribution patterns of anorectal atresia/stenosis in China:Use of two-dimensional graph-theoretical clustering

AIM:To investigate the spatial distribution patterns of anorectal atresia/stenosis in China.METHODS:Data were collected from the Chinese Birth Defects Monitoring Network(CBDMN),a hospital-based congenital malformations registry system.All fetuses more than 28 wk of gestation and neonates up to 7 d of age in hospitals within the monitoring sites of the CBDMN were monitored from 2001 to 2005.Two-dimensional graph-theoretical clustering was used to divide monitoring sites of the CBDMN into different clusters according to the average incidences of anorectal atresia/stenosis in the different monitoring sites.RESULTS:The overall average incidence of anorectal atresia/stenosis in China was 3.17 per 10000 from 2001 to 2005.The areas with the highest average incidences of anorectal atresia/stenosis were almost always focused in Eastern China.The monitoring sites were grouped into 6 clusters of areas.Cluster 1 comprised the monitoring sites in Heilongjiang Province,Jilin Province,and Liaoning Province;Cluster 2 was composed of those in Fujian Province,Guangdong Province,Hainan Province,Guangxi Zhuang Autonomous Region,south Hunan Province,and south Jiangxi Province;Cluster 3 consisted of those in Beijing Municipal City,Tianjin Municipal City,Hebei Province,Shandong Province,north Jiangsu Province,and north Anhui Province;Cluster 4 was made up of those in Zhejiang Province,Shanghai Municipal City,south Anhui Province,south Jiangsu Province,north Hunan Province,north Jiangxi Province,Hubei Province,Henan Province,Shanxi Province and Inner Mongolia Autonomous Region;Cluster 5 consisted of those in Ningxia Hui Autonomous Region,Gansu Province and Qinghai Province;and Cluster 6 included those in Shaanxi Province,Sichuan Province,Chongqing Municipal City,Yunnan Province,Guizhou Province,Xinjiang Uygur Autonomous Province and Tibet Autonomous Region.CONCLUSION:The fi ndings in this research allow the display of the spatial distribution patterns of anorectal atresia/stenosis in China.These will have important guiding significance for further analysis of relevant environmental factors regarding anorectal atresia/ stenosis and for achieving regional monitoring for anorectal atresia/stenosis.

Hierarchical Self-assembly of G-Quadruplexes Based Hydrogel Consisting of Guanine and Peptide Epitope

Guanosine-based hydrogels have attracted considerable attention because of their simplicity and easy preparation.However,the sugar moiety limits its further applications because of the necessity of sugar in the hydrogel formation.This work reports a G-quadruplexes-based hydrogel consisting of guanine and peptide epitope to form a supramolecular hydrogel in the presence of metal cations.Using the metal ion-responsive peptide epitope from the ion channel to replace sugar motif at N9 position of guanosine results in a novel nucleopeptide.The results show that the gelation time,the diameter of nanofibers,the anisotropic property,and the mechanical property of the hydrogel can be simply controlled using metal cations.The magnesium and calcium ions direct the alignment of nanofibers to form anisotropic nano-bundles.The mechanistic studies indicate the formation of G-quadruplexes in the hydrogel.Compared to the storage modulus of nucleopeptide without the metal cation,adding zinc ions results in an over three-order increase in mechanical properties.Cytotoxicity experiment indicates the good biocompatibility of our hydrogel.Moreover,we demonstrate that the guanine-capped peptide could release STING agonist in a controlled manner.This work illustrates a simple way to modulate the property of the nucleopeptide hydrogel to develop soft materials.

Efficacy of inactivated SARS-CoV-2 vaccination in pediatric hematology/oncology patients:a real-world study

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has been spreading globally since its initial outbreak in 2019.Substantial evidence has revealed that children who are receiving antitumor therapy or hematopoietic stem cell transplantation(HSCT)present higher rates of severe illness and mortality[1].It is important to identify infected children with hematology and oncology diseases who have the tendency to develop worse outcomes of coronal virus disease 2019(COVID-19)during the early stage of COVID-19.Recent studies have demonstrated that vaccination against SARS-CoV-2 in adults can reduce the likelihood of infection and reduce the severity and mortality of COVID-19 when SARS-CoV-2 breakthrough infection occurs[2,3,4].However,the effectiveness of SARS-CoV-2 vaccination in children with hematology and oncology diseases is poorly defined due to the lack of relevant data,which might lead to vaccine hesitancy[5,6].

Disparities of Heatwave-Related Preterm Birth in Climate Types—China,2012-2019

What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types have not been examined.What is added by this report?This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types.Among pregnant women residing in the arid-desertcold climate type,exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth{adjusted odds ratios(AORs)ranged from 1.55[95%confidence interval(CI):1.21-1.97]to 2.11(95%CI:1.35-3.31)}.In contrast,among pregnant women residing in the tropical monsoonal climate type,exposure to daytime-only heatwaves was associated with an increased risk of preterm birth[AORs ranged from 1.25(95%CI:1.03-1.51)to 1.37(95%CI:1.05-1.77)].

A Dynamic Emergency Decision-Making Method Based on Group Decision Making with Uncertainty Information

In emergency decision making(EDM),it is necessary to generate an effective alternative quickly.Case-based reasoning(CBR)has been applied to EDM;however,choosing the most suitable case from a set of similar cases after case retrieval remains challenging.This study proposes a dynamic method based on case retrieval and group decision making(GDM),called dynamic casebased reasoning group decision making(CBRGDM),for emergency alternative generation.In the proposed method,first,similar historical cases are identified through case similarity measurement.Then,evaluation information provided by group decision makers for similar cases is aggregated based on regret theory,and comprehensive perceived utilities for the similar cases are obtained.Finally,the most suitable historical case is obtained from the case similarities and the comprehensive perceived utilities for similar historical cases.The method is then applied to an example of a gas explosion in a coal company in China.The results show that the proposed method is feasible and effective in EDM.The advantages of the proposed method are verified based on comparisons with existing methods.In particular,dynamic CBRGDM can adjust the emergency alternative according to changing emergencies.The results of application of dynamic CBRGDM to a gas explosion and comparison with existing methods verify its feasibility and practicability.

Traditional Chinese medicine treatment for COVID-19:An overview of systematic reviews and meta-analyses

Background:Coronavirus disease 2019(COVID-19)is a rapidly spreading disease that has caused an extensive burden to the world.Consequently,a large number of clinical trials have examined the efficacy of traditional Chinese medicine(TCM)for treating and preventing COVID-19,with coinciding proliferation of reviews summarizing these studies.Objective:This study aimed to evaluate the methodological quality and evidence quality of systematic reviews and meta-analyses on the efficacy of TCM.Search strategy:Seven electronic databases,including PubMed,Cochrane Library,Web of Science,China National Knowledge Infrastructure,Chongqing VIP,Wanfang Data and SinoMed,were searched for systematic reviews and meta-analyses in October 2021.Search terms such as“Chinese medicine,”“Lianhua Qingwen”and“COVID-19”were used.Inclusion criteria:Systematic reviews and meta-analyses of randomized controlled trials that evaluated the efficacy of TCM treatment of COVID-19 were included.Data extraction and analysis:A Measurement Tool to Assess Systematic Reviews Version 2.0(AMSTAR 2)was used to evaluate the methodological quality.The quality of evidence was graded using the Grading of Recommendations Assessment,Development,and Evaluation(GRADE)system.Data extraction and analysis were performed by two reviewers independently.Results:There were 17 meta-analyses included in our overview.The intervention group was defined as TCM combined with Western medicine,while the control group was Western medicine alone.The methodological quality of all the included studies was moderate to poor.A total of 89 outcome indicators were evaluated,of which,8 were rated as moderate quality,39 as low quality,and 41 as very low quality.Only one outcome measure was graded as being of high quality.The moderate quality of evidence indicated that,for the treatment of COVID-19,the clinical efficacy of TCM in combination with Western medicine was better,in terms of lung recovery,rate of conversion to severe/critical cases,symptom scores,duration of symptoms,mortality,and length of hospital stay.Conclusion:Evidence from the included studies shows that,compared with conventional Western medical therapy alone,the addition of TCM to COVID-19 treatment may improve clinical outcomes.Overall,the quality of evidence of TCM for COVID-19 was moderate to poor.Meta-analyses of the use of TCM in the treatment of COVID-19 can be used for clinical decision making by accounting for the experiences of clinical experts,medical policies,and other factors.

Effect of doped strontium on catalytic properties of La_(1-x)SrxMnO_(3) for rhodamine B degradation

A series of La_(1-x)Sr_(x)MnO_(3) samples were prepared by sol-gel method and used to degrade rhodamine B(RhB) in water.All samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),N_(2) adsorption-desorption,temperature-programmed reduction of H_(2)(H_(2)-TPR) and temperature-programmed desorption of O_(2)(O_(2)-TPD).The results show that the degradation of RhB is highly dependent on the initial pH value of solution.Sr doping enhances the degradation ability of LaMnO_(3) for RhB in the time range of 0-40 min under a strong acidic environment,but all samples exhibit similar degradation rate from 40 to 60 min.In La_(0.7)Sr_(0.3)MnO_(3)-RhB reaction system,there are two different degradation pathways,including N-de-ethylation,chromophore cleavage,ring-opening and mineralization.La_(1-x)Sr_(x)MnO_(3)(x ≤0.3) has the perovskite structure of La-Mn oxides,while La_(0.6)Sr_(0.4)MnO_(3) exhibits a Sr_(0.4)MnLa_(0.6)O_(2).98 perovskite phase.Sr doping leads to distortion of rhombohedral crystal structure and increases the relative content of Mn^(4+).The perovskite structure is stable in strong acidic environment during RhB degradation,but the relative content of Mn^(4+)and Mn^(3+) on the material surface changes.Sr doped LaMnO_(3) achieves specific surface area of 58.8 m^(2)/g and total pore volume of 0.152 cm^(3)/g.Furthermore,Sr^(2+)doping improves redox properties of La-Mn oxides,and the presence of defects makes oxygen diffusion easier compared with the undoped samples.

A Geometric Strategy Algorithm for Orthogonal Pro jection onto a Parametric Surface

In this paper, we investigate how to compute the minimum distance between a point and a parametric surface, and then to return the nearest point (foot point) on the surface as well as its corresponding parameter, which is also called the point projection problem of a parametric surface. The geometric strategy algorithm (hereafter GSA) presented consists of two parts as follows. The normal curvature to a given parametric surface is used to find the corresponding foot point firstly, and then the Taylor's expansion of the parametric surface is employed to compute parameter increments and to get the iteration formula to calculate the orthogonal projection point of test point to the parametric surface. Our geometric strategy algorithm is essentially dependent on the geometric property of the normal curvature, and performs better than existing methods in two ways. Firstly, GSA converges faster than existing methods, such as the method to turn the problem into a root-finding of nonlinear system, subdividing methods, clipping methods, geometric methods (tangent vector and geometric curvature) and hybrid second-order method, etc. Specially, it converges faster than the classical Newton's iterative method. Secondly, GSA is independent of the initial iterative value, which we prove in Theorem 1. Many numerical examples confirm GSA's robustness and efficiency.

Temporal Trends of Maternal Mortality Due to Obstetric Hemorrhage in Chinese Mainland: Evidence from the Population-Based Surveillance Data Between 2000 and 2019

Objective:To analyze the temporal trends of maternal mortality ratio(MMR)due to obstetric hemorrhage and its specific causes in Chinese mainland from 2000 to 2019,to identify whether the rate of change has accelerated or slowed down during this period,and to find the prior cause of obstetric hemorrhage that needs to be intervened in the future.Methods:Individual information on maternal deaths and total number of live births from 336 surveillance sites across 31 provinces in Chinese mainland was collected from the National Maternal and Child Health Surveillance System between 2000 and 2019.Maternal death was defined according to the World Health Organization’s criterion.The final underlying cause of death was confirmed by the national review and was coded according to International Classification of Diseases-10.Linear trends for changes in characteristics of maternal deaths were assessed using linear or logistic models with the year treated as a continuous variable.The MMR and 95%confidence intervals(CI)for regions or causes were estimated by Poisson’s distribution.Joinpoint regression was used to assess the accurate temporal patterns.Results:The national MMR due to obstetric hemorrhage was 18.4 per 100,000 live births(95%CI:15.0–22.2)in 2000.It peaked in 2001(22.1 per 100,000 live births,95%CI:18.3–26.4)and was lowest in 2019(1.6 per 100,000 live births,95%CI:1.0–2.3).For specific regions,the MMR due to obstetric hemorrhage in rural areas and western regions both experienced a slight rise,followed by a rapid decline,and then a slow decline.For specific causes,no change point was found in joinpoint analysis of the national MMR caused by placenta previa,postpartum uterine atony,and retained placenta(the annual percent change was12.0%,10.5%,and21.0%,respectively).The MMR caused by postpartum hemorrhages(PPH)significantly declined by 8.0%(95%CI:1.9–13.6)per year from 2000 to 2007.The annual percent change of MMR caused by PPH accelerated further to25.0%between 2007 and 2011,and then decreased to7.8%between 2011 and 2019.The proportion of maternal deaths due to antepartum hemorrhages increased from 7.6%(8/105)in 2000 to 14.3%(4/28)in 2019.The changes in the proportion of causes were different for maternal deaths due to PPH.The proportion of postpartum uterine atony increased from 39.0%(41/105)in 2000 to 60.7%(17/28)in 2019,and the proportion of uterine rupture also increased from 12.3%(13/105)in 2000 to 14.3%(4/28)in 2019.However,the proportion of retained placenta decreased from 37.1%(39/105)in 2000 to 7.1%(2/28)in 2019.Conclusion:Over the last 20 years,the intervention practice in China has proved that targeted interventions are beneficial in reducing the MMR due to obstetric hemorrhage.However,the MMR has reached a plateau and is likely to increase for some specific causes such as uterine rupture.China needs to develop more effective interventions to reduce maternal deaths due to obstetric hemorrhage,especially for postpartum uterine atony and uterine rupture.

ASYMPTOTIC EIGENVALUE ESTIMATION FOR A CLASS OF STRUCTURED MATRICES

In this paper we consider eigenvalue asymptotic estimations for a class of structured matrices arising from statistical applications. The asymptotic upper bounds of the largest eigenvalue(λmax) and the sum of squares of eigenvalues(■)are derived. Both these bounds are useful in examining the stability of certain Markov process. Numerical examples are provided to illustrate tightness of the bounds.

National Perinatal Prevalence of Selected Major Birth Defects--China,2010−2018

Introduction:An estimated of 900,000 infants are born with birth defects each year in China causing a substantial disease burden.This study aimed to depict the epidemiological patterns of selected major birth defects in Chinese perinatal births and provide important baseline data for future prevention.Methods:Data from the Chinese Birth Defects Monitoring Network(CBDMN)during 2010–2018 were used to analyze the epidemiological pattern in the prevalence of 15 major birth defects and the trends over time.Results:In the period of 2010–2018,the top 10 most frequently-occurring birth defects in China included congenital heart diseases(CHDs),polydactyly,cleft lip with or without palate(CL/P),club foot,syndactyly,hydrocephalus,hypospadias,limb reduction defects(LRD),anotia/microtia,and anorectal atresia/stenosis.There was a decrease in the prevalence of neural tube defects,CL/P,hydrocephalus,LRD,gastroschisis,and omphalocele,but there were increases in the prevalence of CHDs,cleft palate,hypospadias,club foot,polydactyly,and syndactyly.The prevalence of most birth defects varied significantly by maternal age,area types(urban/rural),and geographic regions.Conclusions and Implications for Public Health Practice:The findings indicated that the comprehensive prevention of birth defects should focus on these selected birth defects,elderly pregnant women,rural areas,and western regions.

Determination of the predictive factors for diagnostic positivity of nucleic acid amplification tests for diagnosing pulmonary tuberculosis

Background:Tuberculosis(TB)remains a major threat to human health,and TB diagnostic methods remain unsatisfactory.Nucleic acid amplification tests(NAATs)show higher sensitivity compared with culture for the diagnosis of pulmonary TB(PTB).However,NAATs are expensive and cannot be easily implemented outside major medical centers.To improve the sensitivity of NAATs for PTB diagnosis,we investigated the predictive factors that might optimize NAAT utilization.Methods:A total of 1263 patients with suspected PTB were enrolled for evaluation.The sensitivity,specificity,and accuracy of methods including smear-microbiology,culture of Mtb and NAAT for Mycobacterium tuberculosis(Mtb)detection in sputum and bronchoalveolar lavage fluid samples were compared.Odds ratios and 95%confidence intervals were used to assess variables that might be associated with positive NAAT results for sputum and bronchoalveolar lavage fluid from patients with suspected PTB.Results:NAAT showed higher sensitivity for Mtb detection(61.1%)when compared with smear(9.0%)and Mtb culture(47.8%).We found that an elevated erythrocyte sedimentation rate,the presence of cavities,and positive interferon-𝛾release assay(IGRA)results were indicative of positive Mtb detection by NAAT.Moreover,individuals who had all three of these characteristics showed an 86%diagnostic positivity for PTB from Mtb detection by NAAT.Conclusions:Our study suggests that an elevated erythrocyte sedimentation rate,a positive IGRA result,and the presence of pulmonary cavities are helpful factors for predicting positive Mtb detection by NAAT.Patients with the three positive clinical markers should undergo NAAT for Mtb detection because they are the most likely individuals to be bacteriologically confirmed as having TB.

Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages

Background:With an increasing proportion of multiparas,proper interpregnancy intervals(IPIs)are urgently needed.However,the association between IPIs and adverse perinatal outcomes has always been debated.This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.Methods:We used individual data from China’s National Maternal Near Miss Surveillance System between 2014 and 2019.Multivariable Poisson models with restricted cubic splines were used.Each adverse outcome was analyzed separately in the overall model and stratified models.The stratified models included different categories of fertility policy periods(2014-2015,2016-2017,and 2018-2019)and infant gestational age in previous pregnancy(<28 weeks,28-36 weeks,and≥37 weeks).Results:There were 781,731 pregnancies enrolled in this study.A short IPI(≤6 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.63[1.55,1.71]for vaginal delivery[VD]and 1.10[1.03,1.19]for cesarean section[CS]),low Apgar scores and small for gestational age(SGA),and a decreased risk of diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.A long IPI(≥60 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.18[1.11,1.26]for VD and 1.39[1.32,1.47]for CS),placenta previa,postpartum hemorrhage,diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes.The estimated risk of preterm birth,low Apgar scores,SGA,diabetes mellitus in pregnancy,and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.Conclusion:For pregnant women with shorter or longer IPIs,more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.