A Comparison between Late Preterm and Term Infants with Respiratory Distress Syndrome, Early-Onset Sepsis, and Neonatal Jaundice in Ecuadorian Newborns

Background: To examine the differences in prevalence of respiratory distress syndrome, early-onset sepsis and jaundice, between late preterm infants versus term infants in Ecuadorian newborns. Methods: Study design: Epidemiological, observational, and cross-sectional, with two cohorts of patients. Settings: IESS Quito Sur Hospital at Quito, Ecuador, from February to April of 2020. Participants: This study included 204 newborns, 102 preterm infants, 102 term infants. Results: There are significant differences between late preterm infants and term infants, with a p-value of 0.000 in the prevalence of early sepsis, 70.59% vs. 35.29%. In respiratory distress syndrome between late and term premature infants, significant differences were observed with a p-value of 0.000, the proportion being 55.58% vs. 24.51% respectively. The prevalence of jaundice is higher in term infants with a p value of 0.002, 72.55%, versus 51.96% in late preterm infants, and the mean value of bilirubins in mg/dL was higher in term infants 14.32 versus 12.33 in late preterm infants;this difference is statistically significant with a p value of 0.004. Admission to the NICU is more frequent in late preterm infants with a p-value of 0.000, being 42.16% for late preterm infants vs. 7.84% in term infants;the mean of the hospital days with p-value 0.005, was higher in late preterm infants 4.97 days vs. 3.55 days for term newborns. Conclusion: Due to the conditions of their immaturity, late preterm infants are 2.86 times more likely to present early sepsis than full-term newborns. It is shown that late preterm infants are 2.69 times more likely to have respiratory distress syndrome compared to term infants, therefore, late preterm infants have a longer hospital stay of 4.97 days versus 3.55 days in term infants. Jaundice and mean bilirubin levels are higher in term infants due to blood group incompatibility and insufficient breastfeeding.

Differences in Precipitation and Related Wind Dynamics and Moisture and Heat Features in Separate Areas of the South China Sea before and after Summer Monsoon Onset

Using surface and balloon-sounding measurements, satellite retrievals, and ERA5 reanalysis during 2011–20, this study compares the precipitation and related wind dynamics, moisture and heat features in different areas of the South China Sea(SCS) before and after SCS summer monsoon onset(SCSSMO). The rainy sea around Dongsha(hereafter simply referred to as Dongsha) near the north coast, and the rainless sea around Xisha(hereafter simply referred to as Xisha) in the western SCS, are selected as two typical research subregions. It is found that Dongsha, rather than Xisha, has an earlier and greater increase in precipitation after SCSSMO under the combined effect of strong low-level southwesterly winds, coastal terrain blocking and lifting, and northern cold air. When the 950-h Pa southwesterly winds enhance and advance northward, accompanied by strengthened moisture flux, there is a strong convergence of wind and moisture in Dongsha due to a sudden deceleration and rear-end collision of wind by coastal terrain blocking. Moist and warm advection over Dongsha enhances early and deepens up to 200 h Pa in association with the strengthened upward motion after SCSSMO, thereby providing ample moisture and heat to form strong precipitation. However, when the 950-h Pa southwesterly winds weaken and retreat southward, Xisha is located in a wind-break area where strong convergence and upward motion centers move in. The vertical moistening and heating by advection in Xisha enhance later and appear far weaker compared to that in Dongsha, consistent with later and weaker precipitation.

Clinical characteristics of patients with early-and late-onset optic neuromyelitis optica spectrum disease

Objective:To analyze the different clinical features of patients with early-onset(EO-NMOSDs)and late-onset neuromyelitis optica spectrum diseases(LO-NMOSDs).Methods:A total of 51patients with neuromyelitis optica spectrum disease who were diagnosed in our hospital for the first time from January 2015 to December 2022 were included in the First Affiliated Hospital of Hainan Medical College and divided into 22 cases in the EO-NMOSDs group and 29 cases in the LO-NMOSDs group according to whether the age of onset was 50 years old.The basic data,Extended Disability Status Scale(EDSS)score,blood and cerebrospinal fluid test indicators of the two groups were statistically analyzed.Results:There were no significant differences in demographic characteristics,clinical features and serum AQP-4 antibody positivity rate between the two groups(all P>0.05),and there were significant differences in triglycerides(TG),low-density lipoprotein(LDL),apolipoprotein A(APOA),apolipoprotein B(APOB)and lipoprotein a(P=0.010,P=0.048,P=0.014,P=0.061,P=0.001,respectively),and cerebrospinal fluid LDH,There were significant differences between microprotein quantification and EDSS score(P=0.018,P=0.034,P=0.025,respectively),and the level of microprotein quantification in cerebrospinal fluid of LO-NMOSDs had a certain correlation with the degree of disability(r=0.52,P<0.03).Conclusion:LO-NMOSDs and EO-NMOSDs group patients have similar demographic characteristics,serum AQP-4 antibody positive rate and clinical features,but compared with EO-NMOSDs,patients in LO-NMOSDs group are prone to abnormal lipid metabolism,higher trace proteins in cerebrospinal fluid and more likely to be disabled,and among LO-NMOSDs,the higher the trace protein in the cerebrospinal fluid,the more severe the disability status of patients.

Early‐onset scoliosis in children aged 4–7 years in Nanjing,China:A cross‐sectional study

Background:This study aimed to investigate the potential variance in the prevalence of early‐onset scoliosis among children aged 4–7 years and analyze the influencing factors.The goal was to establish a crucial reference point for monitoring and evaluating spinal curvature development in preschoolers,ultimately to reduce the occurrence of adverse health outcomes.Methods:Children aged 4–7 years within the main urban area of Nanjing were selected using a stratified random sampling method.A team of four senior therapists conducted screenings for spinal curvature among children using visual inspection,the Adams forward bending test,and an electronic scoliometer to measure the angle of trunk rotation(ATR)and identify children displaying signs of scoliosis.Children with suspected scoliosis in the initial screening underwent X‐ray Cobb angle assessment for confirmation.The prevalence of early‐onset scoliosis was then determined from the screening results.R version 4.2.0 software was used to analyze the factors associated with scoliosis among children using partial least squares structural equation modeling.Results:A total of 2281 children were included in this study,consisting of 1211 boys and 1070 girls,with a mean age of 5.44±0.81 years(ranging from 4 to 7 years).Among them,7.58%exhibited positive signs of scoliosis,5.87%had early‐onset scoliosis,and the positive predictive value was 77.5%.Significant differences in ATR were observed among children in different age groups(Kruskal–Wallis=15,p=0.0104)and by sex(t=3.17,p=0.00153).Significant variations in ATR were noted in children with scoliosis(t=−22.7,p<0.001),with a cutoff at ATR=4.5°,and auxiliary values of 0.947 and 0.990.Children diagnosed with early‐onset scoliosis generally exhibited lower body mass index values,with a statistically significant difference(t=2.99,p=0.003).Conclusions:Using visual inspection,the Adams test,and an electronic scoliometer to measure the ATR,the present triad method is more sensitive for early scoliosis screening in children with abnormal posture aged 4–7 years.A full spine X‐ray is advised in children with an ATR over 4.5°and poor posture.

Climate prediction of the seasonal sea-ice early melt onset in the Bering Sea

基于大尺度环流异常对海冰消融的影响过程,本文采用年际增量预测方法研制了白令海季节性海冰早期消融开始日期(EMO)的统计预测模型.预测模型选取了3个具有明确物理意义的预测因子:1月波弗特高压,前期11月东西伯利亚地区海平面气压,以及11月东欧平原积雪覆盖率。1月波弗特高压可以通过海气相互作用影响白令海地区海温异常,该海温异常能够从1月持续到3月,进而影响白令海EMO.11月东西伯利亚地区海平面气压与11月至次年2月北太平洋中纬度东部海温密切相关。伴随着北太平洋中纬度东部冷海温异常的出现,白令海地区会出现暖海温异常,进而导致白令海海冰范围减少,EMO较晚.1月北极偶极子异常是11月东欧平原积雪覆盖率影响次年白令海EMO的桥梁之一.1981-2022年的交叉检验结果表明:统计模型对白令海EMO具有较好的预测能力,预测与观测的EMO之间时间相关系数达到了0.45,超过了99%的置信水平.统计模型对白令海EMO正常年份和异常年份的预测准确率分别为60%和41%.

高三酰甘油血症-腰围表型与2型糖尿病发病风险:一项前瞻性队列研究

背景高三酰甘油血症-腰围表型是2型糖尿病(T2DM)的风险因素,不同性别、不同地区、不同年龄段及超重/肥胖人群中T2DM发病风险可能不同。目的探讨不同性别、不同地区、不同年龄段及超重/肥胖人群高三酰甘油血症-腰围表型与T2DM发病风险的关系,为糖尿病防控提供科学依据。方法本研究为前瞻性队列研究,2010年采取分层整群随机抽样方法,以贵州省12个县(市、区)18岁及以上9280名常住居民为队列人群进行基线调查。于2016—2020年进行随访,共随访到8163人,剔除基线时糖尿病患者、相关指标信息缺失者、失访和死亡的对象,最终纳入6743名调查对象。根据基线腰围(WC)和血清三酰甘油(TG)水平将调查对象分为4组,正常腰围和正常血清三酰甘油(NWNT)组:男性腰围<90 cm或女性腰围<85 cm、血清三酰甘油<1.7 mmol/L;正常腰围和高血清三酰甘油(NWHT)组:男性腰围<90 cm或女性腰围<85 cm、血清三酰甘油≥1.7 mmol/L;腰围增大和正常血清三酰甘油(EWNT)组:男性腰围≥90 cm或女性腰围≥85 cm、血清三酰甘油<1.7 mmol/L;腰围增大和高血清三酰甘油(EWHT)组:男性腰围≥90 cm或女性腰围≥85 cm、血清三酰甘油≥1.7 mmol/L。采用Cox比例风险回归模型分析高三酰甘油血症-腰围表型分组与新发T2DM之间的关系。结果中位随访时间6.58年,6743名调查对象中新发T2DM 706例,发病率为10.47%。在调整了相关的混杂因素后,Cox比例风险回归分析显示,EWHT组T2DM发病风险是NWNT组的1.486倍(HR=1.486,95%CI=1.185~1.865,P=0.001)。亚组多因素Cox比例风险回归分析显示,在男性、农村、年龄<45岁、超重/肥胖人群中,EWHT组T2DM发病风险分别是NWNT组的1.792倍(HR=1.792,95%CI=1.297~2.476,P<0.001)、1.483倍(HR=1.483,95%CI=1.115~1.971,P=0.007)、1.540倍(HR=1.540,95%CI=1.083~2.190,P=0.016)、1.614倍(HR=1.614,95%CI=1.123~2.321,P=0.010)。结论对大样本人群进行中位随访6.58年后,高三酰甘油血症-腰围表型是贵州省T2DM的发病风险,在男性、农村、年龄<45岁、超重/肥胖人群中更为显著。因此,对这类人群应该加强健康教育,通过合理饮食、适当运动从而控制体质量,降低血清三酰甘油水平是预防T2DM发病的必要手段和有效的方法。

Prognostic value of C-reactive protein levels within 6 hours after the onset of acute anterior myocardial infarction with primary PCI

Background Increased levels of inflammatory markers have been documented in various settings of coronary artery disease. The vulnerability of coronary lesions in acute myocardial infarction(AMI) at the time of onset may be related to serum levels of C reactive protein(CRP) on admission, before CRP levels are affected by myocardial damage.Objective This study assessed the predictive value of CRP levels within six hours after the onset of acute anterior myocardial infarction with primary percutaneous coronary intervention(PCI).Methods The plasma CRP of 76 patients with first acute anterior myocardial infarction was measured within 6 hours after onset. They were divided into 2 groups: group 1( n =20) with elevated CRP( ≥0.3mg/dl ) on admission within 6 hours after onset and group 2( n =56) with normal CRP( <0.3mg/dl ) within 6 hours after onset. All patients were treated by primary PCI. The primary combined end points, including death due to cardiac causes, re MI related to the infarction artery(RIA) and repeat intervention of the RIA, and the restenosis rate were assessed in relation to CRP levels within 6 hours after onset. Left ventricular end diastolic volume index(EDVI),end systolic volume index(ESVI),and ejection fraction(EF) on admission and 6 month after the onset were assessed by left ventriculography. Changes in EDVI(ΔEDVI),ESVI(ΔESVI), and EF(ΔEF) were obtained by subtracting respective on admission values from corresponding 6 month follow up values. Results There were no significant differences in baseline characteristics between the two groups. The primary combined end points were significantly more frequent in group 1(20%) than those in group 2( 1.79% , P <0.01 ).In addition, restenosis rates were significantly higher in group 1 than in group 2(41.18% vs 16.07%, P<0.05). Group 1 showed greater increases in left ventricular volume and less improvement in EF compared with group 2(ΔEDVI 6.31 ±2.17 vs 3.29 ±9.46ml/m 2 , ΔESVI 5.92 ±2.31 vs 3.86 ±1.08ml/m 2 , ΔEF 1.92 ±0.47 vs 4.79 ±1.73% , P <0.05 , respectively).Conclusions CRP levels within 6 hours after the onset of AMI might predict adverse outcome after primary PCI and progressive ventricular remodeling within 6 month of AMI.

从温病卫气营血辨治成人斯蒂尔病验案1则

卫气营血理论是温病学中重要的基础理论,通过将疾病分为卫分证、气分证、营分证、血分证4个阶段,以此论治外感温病。因势利导是中医学重要的治则,在本例验案中体现在“给邪以出路”。成人斯蒂尔病是一种以发热、关节痛、皮疹为主要特征的自身免疫性疾病,西医诊治手段有限。此文通过分享中医治疗成人斯蒂尔病验案1则,探讨温病卫气营血辨证以及因势利导在成人斯蒂尔病中的应用。

Onset功能对腔内心电图诊断成功率的影响分析

目的:探讨与分析Onset功能对腔内心电图诊断成功率的影响。方法:2016年6月至2018年6月本院收治的起搏器植入患者77例作为研究对象,在植入后第12个月(±14d),采集所有患者的腔内心电图并分为两份,一份隐去Onset的信息(A图),另一份保持原样(B图),由腔内心电图判别小组进行诊断效果判定。结果:77例患者中共记录了495个EGM,起搏器诊断室性心动过速281个,房性心动过速反应200个,非持续性VT 14个。A图中有370个(74.75%)判别为正确的心律失常事件;根据B图判定,起搏器腔内心电图诊断正确率达79.39%,假阳性率20.61%。结论:Onset功能能提高起搏器植入术患者腔内心电图对于心律失常的诊断成功率,能反映患者的心功能状况,有很好的临床应用价值。

Survey for late-onset hypogonadism among old anti middle-aged males in Shanghai communities

This study sought to investigate late-onset hypogonadism （LOH） in old and middle-aged males in Shanghai communities, using symptom score evaluation systems and measurements of sex hormone levels. One thousand cases of males aged 40-70 years were investigated. The aging male symptoms （AMS） scale and androgen deficiency in aging males （ADAM） questionnaire were used at the beginning of the investigation, followed by measurement of the sex hormone-related factors （total testosterone （TT）, free testosterone （fT）, sex hormone-binding globulin （SHBG） and bioavailability of testosterone （Bio-T））. There were 977 valid questionnaires. The LOH-positive rates shown by AMS and ADAM were 59.88% and 84.65%, respectively; values increased with the age of the patients. There were 946 results related to sex hormone measurements, which showed the following results： TT was not related to aging （P〉O.05）; levels of SHBG increased with age; and fT and Bio-T decreased with age. There was a significant difference in fT between LOH-positive and LOH-negative patients, as shown by the ADAM. In summary, TT levels were not related to aging, even though SHBG did increase while fT and Bio-T decreased with aging. Clinically, the diagnosis of LOH cannot be based on serum TT level.

Surveys of serum reproductive hormone levels and the prevalence rates of late onset of hypogonadism in Chinese aging males

Objective:To investigate the change patterns of reproductive hormones in serum of aging males and the difference among male age brackets and the prevalence rates of late onset of hypogonadism(LOH) in males in Chinese middle and aging males. Methods:Subjects included 1,498 men aged 40 to 69 from a county,and the serum reproductive hormones of 434 subjects were measured and calculated.In addition,the prevalence rates of LOH were analyzed by cut-off point of total testosterone(TT) and free testosterone(cFT),and screening scales(a questionnaire of androgen deficiency in the aging males(ADAM) and a scale of aging males’ symptoms(AMS)).TT,cFT,bio-available testosterone (Bio-T),luteinizing hormone(LH),sex hormone binding globulin(SHBG),testosterone secretion index(TSI), free testosterone index(FTD,the positive rates of LOH screening,androgen deficiency rates and the clinical prevalence rates of LOH were measured or calculated. Results:The serum TT levels did not change significantly with male aging while serum LH and SHBG levels gradually increased,but cFT,Bio-T,TSI and FTI levels gradually decreased with male aging.There was very significant difference in other six parameters of reproductive hormones(P<0.01),except for serum TT among the four age brackets(P>0.05).There was no correlation between serum TT levels and aging,LH levels(P>0.05). However,there was significantly a positive correlation between serum LH,SHBG and age(P<0.01),while there were negative correlation between cFT,Bio-T,TSI,FTI and age,LH levels(P<0.01).Moreover,SHBG level was positively correlated with LH level(P<0.01). Utilizing the Questionnaire of ADAM and AMS to screen subjects aged 40 to 69 years,mean positive rates of LOH screening were 80.77%and 32.34%respectively.Mean androgen deficiency rates were 14.02%and 43.69% by using TT and cFT cut-off point.In addition,mean LOH clinical prevalence rates of subjects on positive questionnaire results were 37.85%and 15.42%. Conclusion:The serum TT levels did not change significantly with male aging while serum LH,SHBG,cFT, Bio-T,TSI and FTI levels had the gradient change with aging.On the basis of Chinese population,however,the positive rate of LOH screening,androgen deficiency rate and clinical prevalence rate of LOH were obviously higher than that those of the other foreign studies.

Erectile function and late-onset hypogonadism symptoms related to lower urinary tract symptom severity in elderly men

The aim of this study was to evaluate the relationship between lower urinary tract symptoms （LUTSs）, erectile dysfunction （ED） and symptomatic late-onset hypogonadism （SLOH） in ageing men in the Aegean region of Turkey. Five hundred consecutive patients 〉40 years old who had been in a steady sexual relationship for the past 6 months and were admitted to one of six urology clinics were included in the study. Serum prostate-specific antigen and testosterone levels and urinary flow rates were measured. All patients filled out the International Prostate Symptom Score and Quality of Life （IPSS-QoL）, International Index of Erectile Function （IIEF） and Aging Males＇ Symptoms （AMS） scale forms. Of the patients, 23.9% had mild LUTSs, 53.3% had moderate LUTSs and 22.8% had severe LUTSs. The total testosterone level did not differ between groups. Additionally, 69.6% had ED. The presence of impotence increased with increasing LUTS severity. Symptomatic late-onset hypogonadism （AMS 〉27） was observed in 71.2% of the patients. The prevalence of severe hypogonadism symptoms increased with the IPSS scores. A correlation analysis revealed that all three questionnaire scores were significantly correlated. In conclusion, LUTS severity is an age-independent risk factor for ED and SLOH. LUTS severity and SLOH symptoms appear to have a strong link that requires etiological and biological clarification in future studies.

Selective androgen receptor modulators for the treatment of late onset male hypogonadism

Several testosterone preparations are used in the treatment of hypogonadism in the ageing male. These therapies differ in their convenience, flexibility, regional availability and expense but share their pharmacokinetic basis of approval and dearth of long-term safety data. The brevity and relatively reduced cost of pharmacokinetic based registration trials provides little commercial incentive to develop improved novel therapies for the treatment of late onset male hypogonadism. Selective androgen receptor modulators （SARMs） have been shown to provide anabolic benefit in the absence of androgenic effects on prostate, hair and skin. Current clinical development for SARMs is focused on acute muscle wasting conditions with defined clinical endpoints of physical function and lean body mass. Similar regulatory clarity concerning clinical deficits in men with hypogonadism is required before the beneficial pharmacology and desirable pharmacokinetics of SARMs can be employed in the treatment of late onset male hypogonadism.

Relationship between Indian Ocean dipole and ENSO and their connection with the onset of South China Sea summer monsoon

Using Reynolds and Smith 1950 - 1998 re-constructed monthly-mean SST to discuss the relationship between the ENSO and Indian Ocean dipole （IOD） and their possible connection with the onset of South China Sea summer monsoon（ SCSSM）, the results are obtained as follows ： Most of IOD events have a closely positive relation to simultaneous ENSO events in summer and autumn. IOD events in autumn （ mature phase） are also closely related to ENSO events in winter （ mature phase）. When these two kinds of events happen in phase, i.e. , positive （negative） IOD events are coupled with E1 Nifío （La Nifía） events, they are always followed by late （ or early） onsets of SCSSM. On the contrary, when these two kinds of events happen out of phase, i.e. positive （negative） IOD events are coupled with La Nifia （ E1 Nifío） events, they are followed by normal onsets of SCSSM. In addition, single IOD events or single ENSO events cannot correspond well to the abnormal onset of SCSSM.

How to recognize late-onset hypogonadism in men wit sexual dysfunction

Late-onset hypogonadism （LOH） has been considered the most common form of male hypogonadism with a prevalence of approximately 1 in 100 men. Diagnosis of LOH should be made in symptomatic men with unequivocally low serum testosterone （T） levels. However, its clinical presentation is often insidious and difficult to recognize because it is characterized by nonspecific symptoms that make differential diagnosis with physiological ageing problematic. Sexual dysfunction is the most important determinant for medical consultation and the most specific symptom associated with low T. We therefore analysed a consecutive series of 1734 subjects who attended our unit for sexual dysfunction to investigate the associations between low T （different thresholds）, sexual parameters, medical history data （delayed puberty, pituitary disease or cryptorchidism） and their physical exam results. Metabolic parameters, in particular waist circumference, display the greatest accuracy in detecting low T. We found that only the association of several symptoms and signs could significantly raise the clinical suspicion of low T. Structured inventories, which cluster together symptoms and signs of hypogonadism, can help clinicians suspect androgen deficiency. In particular, structured interviews, such as ANDROTEST, have been demonstrated to have a greater accuracy when compared to self reported questionnaires in detecting low T levels.

The Summer Monsoon Onset over the Tropical Eastern Indian Ocean: The Earliest Onset Process of the Asian Summer Monsoon

The onset process of the tropical eastern Indian Ocean （TEIO） summer monsoon （TEIOSM） and its relationship with the cross-equatorial flows are investigated via climatological analysis. Climatologically, results indicate that the earliest onset process of the Asian summer monsoon occurs over the TEIO at pentad 22 （April 15-20）. Unlike the abrupt onset of the South China Sea （SCS） summer monsoon, the TEIOSM onset process displays a stepwise advance. Moreover, a close relationship between the TEIOSM development and the northward push of the cross-equatorial flows over 80^-90~E is revealed. A difference vorticity center, together with the counterpart over the southern Indian Ocean, constitutes a pair of difference cyclonic vortices, which strengthens the southwesterly wind over the TEIO and the northerly wind to the west of the Indian Peninsula from the end of March to late May. Therefore, the occurrence of the southwesterly wind over the TEIO is earlier than its counterpart over the tropical western Indian Ocean, and the cross-equatorial flows emerge firstly over the TEIO rather than over the Somali area. The former increases in intensity during its northward propagation, which provides a precondition for the TEIOSM onset and its northward advance.

Late onset fulminant Wilson's disease:A case report and review of the literature

Wilson’s disease(WD)is an autosomal recessive inherited disorder of hepatic copper metabolism.WD can be present in different clinical conditions,with the most common ones being liver disease and neuropsychiatric disturbances.Most cases present symptoms at<40years of age.However,few reports exist in the literature on patients in whom the disease presented beyond this age.In this report,we present a case of late onset fulminant WD in a 58-year-old patient in whom the diagnosis was established clinically,by genetic analysis of the ATP7B gene disclosing rare mutations(G1099S and c.1707+3ins T)as well as by high hepatic copper content.We also reviewed the relevant literature.The diagnosis of WD with late onset presentation is easily overlooked.The diagnostic features and the geneticbackground in patients with late onset WD are not different from those in patients with early onset WD,except for the age.Effective treatments for this disorder that can be fatal are available and will prevent or reverse many manifestations if the disease is discovered early.

On the Onset of the South China Sea Summer Monsoon in 1998

Through analyzing the NCEP/NCAR reanalysis data, the satellite observational data and the ATLAS-2 mooring buoy observational data, it is shown that May 21 is the onset date of the South China Sea summer monsoon in 1998. There were abrupt variations in the general circulation pattern at the lower troposphere and the upper troposphere, in upper jet stream location and in the convection and rainfall over the South China Sea region corresponding to the outbreak of the South China Sea summer monsoon. It is also indicated that there was rainfall in the southern China coastal region before onset of summer monsoon, but it resulted from the (cold) front activity and cannot be regarded as the sign of summer monsoon outbreak in the South China Sea. Key words Onset - South China Sea summer monsoon - General circulation pattern, Jet stream - Convection This work was supported by the State Key Project for Research—“ The South China Sea Monsoon Experiment”, CAS (KZ951-B1-408) and CNSF (49823002).

Characteristics of the Onset of the Asian Summer Monsoon and the Importance of Asian-Australian "Land Bridge"

Based on summarizing previous achievements and characteristics of Asian summer monsoon and the role using data as long and new as possible, the onset of Asian-Australian ＂land bridge＂ in the onset of summer monsoon are further discussed. In particular, the earliest onset area of Asian summer monsoon is comparatively analyzed, and the sudden and progressive characteristics of the onset of summer monsoon in different regions are discussed, Furthermore, the relationships among such critical events during the onset of Asian summer monsoon as the splitting of subtropical high belt over the Bay of Bengal （BOB）, the initiation of convection over Indo-China Peninsula, the westward advance, reestablishment of South Asian High, and the rapid northward progression of convection originated from Sumatra in early summer are studied. The important impact of the proper collocation of she latent heating over Indo-China Peninsula and the sensible heating over Indian Peninsula on the splitting of the subtropical high belt, the deepening of BOB trough, the activating of Sri Lanka vortex （twin vortexes in the Northern and Southern Hemispheres）, and the subsequent onset of South China Sea summer monsoon are emphasized.

Mechanism of Thermal Features over the Indo-China Peninsula and Possible Effects on the Onset of the South China Sea Monsoon

The thermal characteristics during the South China Sea (SCS) summer monsoon onset period near the Indo-China Peninsula are analyzed by using the South China Sea Monsoon Experiment (SCSMEX) reanalysis data from 1 May to 31 August 1998 and the NCEP/ NCAR pentad-mean reanalysis data from January 1980 to December 1995. The possible relationships between the anomaly of thermal features near the Indo-China Peninsula and the SCS monsoon onset are investigated, and the mechanism causing the SCS summer monsoon onset is also discussed. Results from the 1998 SCSMEX reanalysis data show that there exists a strong persistent surface sensible heating near the Indo-China Peninsula prior to the SCS monsoon onset, which has apparent low frequency oscillation features. This sensible healing leads lo a warmer center in the lower atmosphere near the Indo-China Peninsula and strong local horizontal temperature and geopotential height gradients which are favorable to strengthening the southwest wind over the Indo-China Peninsula. It is also found that stronger convergent winds at lower levels and stronger divergent winds at high levels appear, which provide a favorable configuration for the development of vertical motion, enhancement of precipitation, and onset of the SCS monsoon. These results can be verified by analysis of the multi-year mean data. Additionally, it is found that the temperature at 850 hPa increases more rapidly over the Indo-China Peninsula than the South China Sea prior to the SCS monsoon onset, which leads to a strengthening of the temperature difference between the Indo-China Peninsula and the South China Sea. Moreover, results from the analysis of the longitudinal temperature and geopotential height differences show that the eastern retreat of the subtropical high over the Indo-China Peninsula during the period of SCS monsoon onset is associated with the temperature increase over the Indo-China Peninsula and the eastern extension of low trough over the Bay of Bengal.