Bone marrow-derived mesenchymal stem cell-derived exosomeloaded miR-129-5p targets high-mobility group box 1 attenuates neurological-impairment after diabetic cerebral hemorrhage

BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patients with diabetes are unknown.In this study,we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation.AIM To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage.METHODS BMSC-exo were isolated from mouse BMSC media.This was followed by transfection with microRNA-129-5p(miR-129-5p).BMSC-exo or miR-129-5poverexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucoseaffected BV2 cells for in vitro analyses.The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1(HMGB1).Quantitative polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors,such as HMGB1,interleukin 6,interleukin 1β,toll-like receptor 4,and tumor necrosis factorα.Brain water content,neural function deficit score,and Evans blue were used to measure the neural function of mice.RESULTS Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery.MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation.Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases.Furthermore,we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA.CONCLUSION We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes,thereby improving the neurological function of the brain.

Polymetamorphism of the ultrahigh-temperature granulites in the Rauer Group,East Antarctica:new evidence from zircon SHRIMP U-Pb ages

The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UHT metamorphism and P–T path of the UHT granulites have long been debated,which is critical to understanding the tectonic nature and evolution history of the Prydz Belt.Thus,both a sapphirine-bearing UHT metapelitic granulite and a garnet-bearing UHT mafic granulite are selected for zircon SHRIMP U-Pb age dating.The results show that metamorphic zircon mantles yield weighted mean^(206)Pb/^(238)U ages of 918±29 Ma and 901±29 Ma for the metapelitic and mafic granulites,respectively,while zircon rims and newly grown zircons yield weighted mean^(206)Pb/^(238)U ages of 523±9 Ma and 532±11 Ma,respectively.These new zircon age data suggest that the UHT granulites may have experienced polymetamorphism,in which pre-peak prograde stage occurred in the early Neoproterozoic Grenvillian orogenesis(1000–900 Ma),whereas the UHT metamorphism occurred in the late Neoproterozoic to early Paleozoic Pan-African orogenesis(580–460 Ma).This implies that P–T path of the UHT granulites should consist of two separate high-grade metamorphic events including the Grenvillian and Pan-African events,which are supposed to be related to assembly of Rodinia and Gondwana supercontinents respectively,and hence the overprinting UHT metamorphic event may actually reflect an important intracontinental reworking.

The Influence of Depression on Different Age and Gender Groups in Bahawalpur

In Bahawalpur,a cross-sectional study assessed depression prevalence across age and gender groups,involving 442 participants from diverse socioeconomic backgrounds and settings.Utilizing the PHQ9 questionnaire,84%were found to meet depression levels.The findings revealed a higher incidence in females(88%)than males(79%),with the greatest disparity among young adults,particularly young women,due to factors like academic pressure and financial stress.School children had the lowest depression rates(68%),possibly due to better immunity.Elderly individuals exhibited more severe depression,likely related to aging and domestic challenges.The study’s findings highlight a significant variation in depression severity across different demographic groups,with an overall higher incidence in women.The research underscores the necessity for targeted mental health resources and interventions tailored to the specific needs of each demographic group.It also points to the importance of addressing academic and socioeconomic stressors to mitigate depression,particularly among young women.While the study provides valuable insights,it relies on self-reported data,which may introduce bias.Therefore,future research should include clinical assessments to validate these findings and ensure a more accurate representation of depression within the community.

Risk Factors for Geo-Helminthiasis in Children Aged 6 - 36 Months in a Rural Health District in Cameroon

Introduction and Objectives: Soil-Transmitted-Helminthiasis (STH) is a public health problem in Cameroon. The control strategies currently in place, particularly chemoprevention, has shortcomings linked to the target population, which are school-age children. The objective was to determine the prevalence and the risk factors associated with geo-helminthiasis in children aged 0 to 3 years in a rural health district. Method: From December 2020 to May 2021, a descriptive and analytical cross-sectional study of 376 children between 6 and 36 months was carried out in the Akonolinga health district. This was a cluster sampling in 4 health areas. Stool samples were collected and analysed using the mini-FLOTAC method. The results expressed as the number of eggs per gram of stool. A questionnaire on socio-demographic and lifestyle data was administered to the parents. The Chi-squared test was used to measure the association between geo-helminth infection and the data collected. A multivariate analysis using logistic regression was performed (p 0.05). Results: The prevalence of STH was 19.4% (Ascaris lumbricoides: 16% and Trichuris trichiura: 8%). Risk factors were: consumption of contaminated water (AOR = 1.93 [1.03 - 3.6];p = 0.040), early contact of the child with the ground (before age of 4 months) (AOR = 4.9 [2.1 - 11.37];p .001), habit of walking barefoot (AOR = 2.91 [1.1 - 7.97];p = 0.038), and living in a habitat with unpaved ground (AOR = 7.4 [1.55 - 35.7];p = 0.012). Conclusion: The prevalence of STHs in infants was high. Preventive chemotherapy should be extended to this age-group, and other measures intensified.

Factors Associated with Acute Respiratory Infections in Children Aged 0 - 5 Years in the Yénawa District of Cotonou (Benin) in 2023

Introduction: Acute respiratory infections remain one of the main causes of mortality in children aged 0 to 5. This work aimed to study the associated factors with the occurrence of acute respiratory infections in children 0 to 5 years old in Yénawa, Cotonou in 2023. Subjects and Method: It was an analytical cross-sectional study of children aged 0 - 5 years and their mothers in Yénawa, selected by four-degree random sampling. The sampling size, calculated using the Schwartz formula, was 126 children and 126 mothers. The dependent variable was the occurrence of acute respiratory infections. The independent variables were classified into four groups: socio-demographic and economic characteristics, behavioral factors, child-related factors, and environmental factors. Data collected by observation and questionnaire survey were analyzed using STATA version 15 software. Associated factors were investigated by bivariate analysis and multiple logistic regression, at the 5% significance level. Results: A total of 126 children aged 0 - 5 years and 126 mothers were surveyed, aged 23.5 (11 - 36) months and 30 (18 - 48) years respectively. The prevalence of acute respiratory infections was 74.60% (CI95% = 66.89 to 82.30). The associated factors were the mother’s age between 18 and 28 (OR = 10.77;CI95% = 1.89 to 61.27;p = 0.007), the use of charcoal/wood for cooking (OR = 7.36;IC = 1.99 to 27.10;p = 0.003)), children's poor personal hygiene (OR = 8.87;IC = 2.92 to 26.97;p 0.001)), and cohabitation with domestic animals (OR = 7.27;IC = 1.67 to 31.71;p = 0.015). Conclusion: Communicating with mothers about the factors identified will help reduce the prevalence of acute respiratory infections in children aged 0 to 5.

热加工食品中晚期糖基化终末产物和5-羟甲基糠醛的形成、检测与控制

食品加工过程中的美拉德反应有助于形成一些热诱导毒性产物,包括晚期糖基化终末产物(advanced glycation end products,AGEs)和5-羟甲基糠醛(5-hydroxymethylfurfural,5-HMF)。食源性AGEs在体内的积累和循环与糖尿病并发症的发生有关,同时可能诱发氧化应激、炎症和动脉粥样硬化。5-HMF的代谢物5-磺基氧甲基糠醛(5-sulfooxymethylfurfural,5-SMF)有潜在基因毒性和致癌性。如何控制热加工食品中这些危害物的形成已成为食品行业的关注焦点。本文从美拉德反应和焦糖化反应两条途径探究了AGEs和5-HMF的形成机理,并对近5年二者的检测方法进行了综述,阐述了各类方法的优缺点,以期为建立二者的通用检测方法奠定基础。在此基础上,从削减前体物质的供给、阻断中间体的转化,以及去除已经生成的AGEs和5-HMF这3个方面着手,综述了近年来相应所采用的抑制策略,以期为AGEs和5-HMF在食品中的控制及热加工食品质量与安全管理提供理论依据。

New U-Pb age constraints on the upper Banxi Group and synchrony of the Sturtian glaciation in South China

The Nanhua basin in South China hosts well-preserved middle-late Neoproterozoic sedimentary and volcanic rocks that are critical for studying the basin evolution, the breakup of the supercontinent Rodinia, the nature and dynamics of the "snowball" Earth and diversification of metazoans. Establishing a stratigraphic framework is crucial for better understanding the interactions between tectonic, paleoclimatic and biotic events recorded in the Nanhua basin, but existing stratigraphic correlations remain debated, particularly for pre-Ediacaran strata. Here we report new Laser Ablation Inductively Coupled Plasma Mass Spectrometry(LA-ICPMS) U-Pb zircon ages from the middle and topmost Wuqiangxi Formation(the upper stratigraphic unit of the Banxi Group) in Siduping, Hunan Province, South China. Two samples show similar age distribution, with two major peaks at ca. 820 Ma and 780 Ma and one minor peak at ca. 910 Ma, suggesting that the Wuqiangxi sandstone was mainly sourced from Neoproterozoic rocks. Two major age peaks correspond to two phases of magmatic events associated with the rifting of the Nanhua basin, and the minor peak at ca. 910 Ma may correspond to the Shuangxiwu volcanic arc magmatism, which represents pre-collision/amalgamation subduction on the southeastern margin of the Yangtze Block. The youngest zircon group from the topmost Wuqiangxi Formation has a weighted mean age of 714.6±5.2 Ma, which is likely close to the depositional age of the uppermost Banxi Group. This age, along with the ages reported from other sections, constrains that the Banxi Group was deposited between ca. 820 Ma and ca. 715 Ma. The age of 714.6±5.2 Ma from the top of the Wuqiangxi Formation is indistinguishable with the SIMS U-Pb age of 715.9± 2.8 Ma from the upper Gongdong Formation in the Sibao village section of northern Guangxi, South China. It is also, within uncertainties, overlapped with two TIMS U-Pb ages from pre-Sturtian strata in Oman and Canada. These ages indicate that the Jiangkou(Sturtian) glaciation in South China started at ca. 715 Ma instead of ca. 780 Ma and support a globally synchronous initiation of the Sturtian glaciation at ca. 715 Ma.

A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang, China

The age of the Longzhaogou and Jixi Groups of coal measures in eastern Heilongjiang were previouslyconsidered to be Jurassic or mainly Jurassic. But there occur Middle Barremian-Early Albian Aucellina(bivalvia) fossils in the Upper Yunshan Formation of the Longzhaogou Group and the Lower Chengzihe For-mation of the Jixi Group, and the Qihulin Formation of the Longzhaogou Group yields Early Cretaceousbivalve and ammonite fossils. Consequently, the geological ages of the two groups are mainly, or even all, Ear-ly Cretaceous.

MiR-142-3p Regulates ILC1s by Targeting HMGB1 via the NF-κB Pathway in a Mouse Model of Early Pregnancy Loss

Objective Innate lymphoid cells(ILCs)are a class of newly discovered immunocytes.Group 1 ILCs(ILC1s)are identified in the decidua of humans and mice.High mobility group box 1(HMGB1)is predicted to be one of the target genes of miR-142-3p,which is closely related to pregnancy-related diseases.Furthermore,miR-142-3p and HMGB1 are involved in regulating the NF-κB signaling pathway.This study aimed to examine the regulatory effect of miR-142-3p on ILC1s and the underlying mechanism involving HMGB1 and the NF-κB signaling pathway.Methods Mouse models of normal pregnancy and abortion were constructed,and the alterations of ILC1s,miR-142-3p,ILC1 transcription factor(T-bet),and pro-inflammatory cytokines of ILC1s(TNF-α,IFN-γand IL-2)were detected in mice from different groups.The targeting regulation of HMGB1 by miR-142-3p in ILC1s,and the expression of HMGB1 in normal pregnant mice and abortive mice were investigated.In addition,the regulatory effects of miR-142-3p and HMGB1 on ILC1s were detected in vitro by CCK-8,Annexin-V/PI,ELISA,and RT-PCR,respectively.Furthermore,changes of the NF-κB signaling pathway in ILC1s were examined in the different groups.For the in vivo studies,miR-142-3p-Agomir was injected in the uterus of abortive mice to evaluate the abortion rate and alterations of ILC1s at the maternal-fetal interface,and further detect the expression of HMGB1,pro-inflammatory cytokines,and the NF-κB signaling pathway.Results The number of ILC1s was significantly increased,the level of HMGB1 was significantly upregulated,and that of miR-142-3p was considerably downregulated in the abortive mice as compared with the normal pregnant mice(all P<0.05).In addition,miR-142-3p was found to drastically inhibit the activation of the NF-κB signaling pathway(P<0.05).The number of ILC1s and the levels of pro-inflammatory cytokines were significantly downregulated and the activation of the NF-κB signaling pathway was inhibited in the miR-142-3p Agomir group(all P<0.05).Conclusion miR-142-3p can regulate ILC1s by targeting HMGB1 via the NF-κB signaling pathway,and attenuate the inflammation at the maternal-fetal interface in abortive mice.

A New Characterization of Simple K_3-groups

In this paper, We show that the simple K\-3-groups can be characterized by the orders of their maximal abelian subgroups. That is, we have Theorem Let G be a finite group and M a simple K \-3-group. Then G is isomorphic to M if and only if the set of the orders of the maximal abelian subgoups of G is the same as that of M .

AGE GROUPS OF ANTARCTIC KRILL,EUPHAUSIA SUPERBA DANA,IN THE PRYDZ BAY REGION

Age groups of Antarctic krill ( Euphausia superba Dana) in the Prydz Bay region were studied by distribution mixture analysis based on length/frequency data collected by R/V Jidi during the 1989/1990 and 1990/1991 austral summer. Five age groups were determined, i.e. 1 +, 2 +, 3 +, 4 +, and 5 + , or six age groups in all, if the 0 + larvae were included. The mean body length of 1 + to 5 + age groups was 25.70 mm, 40.47 mm, 45.52 mm, 50.52 mm and 54.52 mm respectively. Supposing the difference in body length between successive age groups is a reflection of the yearly growth, the maximum growth rate occurred during the period from 1 + juveniles to 2 + subadults (14.77 mm/a). From 2 + subadults to 3 + adults the growth rate dropped steeply (5.05 mm/a) because at this stage, increase of body length was substituted, to a great extent, by the growth of sexual products. From 3 + onwards the growth rate was maintained at a relatively low level and decreased slowly with age. The relative abundance of age groups 1 + and 2 +, in our sample must be much lower than that in the real population owing to both the large mesh size we used and the distribution difference between juveniles and adults. If we left aside 1 + and 2 + age groups and just looked at the relative abundance of adults, we found that age group 3 + dominated the adult population and that the relative abundance decreased sharply with increasing age. If this situation is normal, one can expect an extremely high mortality rate in adults, 82.6% from 3 + to 4 + and 94.0% from 4 + to 5 +. This is reasonably expectable for the Prydz Bay region.

Evaluation of the Integrated Management Program for Acute Malnutrition in the Douentza Health District, Mopti Region, Mali

Introduction: Malnutrition is a major public health problem in Mali, despite the efforts of the government, its technical and financial partners. The aim of this study was to evaluate the integrated management program for acute malnutrition (IMPAM). Methodology: This was a descriptive cross-sectional study that took place from January to December 2020 in the Douentza health district. The study included anyone with at least one malnourished child aged 6 to 59 months in their care who agreed to take part in the study, community health center staff who had given their consent, and the URENI manager at the Douentza reference health center. Data collected via questionnaires were entered into Excel and then analyzed using Epi-Info version 7 software. Results: A total of 138 acutely malnourished children aged 6 - 59 months, including 71 girls (51.45%), 138 accompanying mothers and 11 health workers, were included in our case study. Among the malnourished, 54.34% were in the 12 - 23 months age group and 69.57% had the severe form. 93% of the mothers interviewed were satisfied with the care provided, and all the health staff interviewed stated that community conflicts had an impact on IMPAM’s activities. Cure rates were 81% in Moderate Outpatient Nutritional Recovery and Education Unit (URENAM), 84% in Severe Ambulatory Nutritional Recovery and Education Unit (URENAS) and 92% in Recovery and Intensive Nutritional Education Unit (URENI). Drop-out rates were 19% in URENAM, 16% in URENAS and 0% in URENI. The death rate was 8% in URENI and 0% in URENAM and URENAS. Conclusion: This study confirms the high prevalence of malnutrition in the district (10.54%). It also reveals that factors such as inter-community conflict and insecurity have seriously affected the IMPAM program.

Association of Erectile Dysfunction and Hypogonadism with Metabolic Syndrome in Men with Lower Urinary Tract Symptoms of Younger and Older Age Groups

The aim of this study was to evaluate the incidence and severity of erectile dysfunction (ED) and hypogonadism in 193 men presenting with lower urinary tract symptoms (LUTSs) in the younger (20 - 39 years old) and older (40 - 60 years old) age groups depending on the presence of metabolic syndrome (MetS). Triglycerides, glucose and high-density lipoprotein cholesterol, serum total testosterone (TT), sex hormone-binding globulin, prostate-specific antigen, pituitary hormones levels were measured in serum. Standardized criteria (2009) were used to determine the prevalence of MetS. Patients were assessed based on the International Prostate Symptom Score (IPSS) and the IPSS-Quality of Life (IPSS-QoL) for LUTSs and the International Index of Erectile Function (IIEF) for ED. Hypogonadism was determined in accordance with the ISA, ISSAM, EAU, EAA and ASA recommendations. In men with MetS in the younger age group the incidence of ED was 2.4 times higher, and that of low TT level and hypogonadism was 8.4 times higher compared to men without the syndrome. In the older age group, an increased incidence of ED and low TT level in men with MetS compared to men without the syndrome was on the trend level, but the incidence of hypogonadism was for sure higher (by 1.6 times). In conclusion, the study showed that ED and hypogonadism are associated with MetS by a high degree of certainty in young men with LUTSs. In men of the older age group with LUTSs, the presence of MetS is not so clearly associated with ED and hypogonadism due to the fact that the incidence of these urogenital diseases is also high in men without MetS.

The Impact of Salivary pH Value and Dental Caries Index on Periodontal Status among Adult Age Groups of Patients from Aseer Region, Saudi Arabia

Background: The patients’ age is considered a modified risk factor that causes periodontal disease, dental caries, and their development. Objective: The present study was designed to evaluate the impact of salivary pH value and dental caries index on periodontal status among adult age groups of patients from Aseer region, Saudi Arabia. Methods: A cross-sectional analysis carried out in the college of dentistry, King Khalid University on 750 adult patients (400 males and 350 females). The adults patients were divided into three equal groups according to the patients’ age: group I (20 - 30 years), group II (31 - 40 years), and group III (41 - 50 years). Plaque index (PLI), gingival index (GI), clinical attachment loss (CAL), and the dental caries index (DMFT) recorded as well as salivary pH. All findings collected, then analyzed by an ANOVA test and the t-test. A p-value at <0.05 was considered a statistical significance level. Results: The clinical findings of the current study showed that there were statistically significant differences in the patients’ age of both males and females. Moreover, there were statistically significant differences in GI. On the other hand, there were highly statistically significant differences in PLI and DMFS, but there were no significant differences in CAL of both males and females Moreover, there were no statistically significant differences in salivary pH. Conclusion: We concluded that DMFT Index correlated to periodontal and oral health status and, it increased with the progression of the patient’s age and can be used in the epidemiological evaluation of periodontal and oral health status.

对流-扩散方程若干AGE格式及其稳定性

以求解对流－扩散方程的中心差分格式、显式逆风格式、Ｓａｍａｒｓｋｉ格式和修正Ｄｅｎｎｉｓ格式为基础，构造了若干新的交替分组显式格式，并证明它们是无条件稳定的．数值结果表明，除了基于中心差分格式的ＡＧＥ格式与ＡＤＥ格式外，其他的各种ＡＧＥ格式与相应的ＡＤＥ格式的精度相当．

基于视网膜Müller细胞的地黄调节AGEs干预下HIF-1α表达的谱效关系研究

目的建立不同来源地黄的高效液相色谱(HPLC)指纹图谱并研究其与糖基化终末产物(AGEs)干预下视网膜Müller细胞中低氧诱导因子-1α(HIF-1α)表达之间的谱效关系,初步阐明地黄防治糖尿病性视网膜病变(DR)的药效物质。方法采用HPLC法建立10批不同来源地黄指纹图谱;采用ELISA法测定地黄对AGEs干预下视网膜Müller细胞中HIF-1α表达的影响;采用偏最小二乘法分析特征峰峰面积与药效值之间的谱效关系。结果 10批样品HPLC指纹图谱共标定了17个特征共有峰,其中4、14、15号峰分别为梓醇、肉苁蓉苷A、毛蕊花糖苷。ELISA结果显示10批样品对AGEs干预下视网膜Müller细胞中HIF-1α的表达均有不同程度的抑制作用。偏最小二乘法分析结果显示,肉苁蓉苷A、毛蕊花糖苷及4个尚未确定结构的成分(峰13、5、16、17)可能是地黄防治DR的药效物质。结论谱效关系为初步阐明地黄防治DR药效物质提供了一个有效途径。

An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave

The main epidemiological features such as basic reproduction number,effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study.Firstly,by using of the next generation matrix method,basic reproduction number R0 of the total population was estimated as 1.57 using parameter values of four age groups of Fuzhou COVID-19 large wave.Given age group k,the values of R_(0k)(age group k to age group k),the values of R_(o)^(k)(an infected of age group k to the total population)and the values of R_(o)^(k)>R_(0k)>R_(o)^(k)(an infected of the total population to age group k)were also estimated,in which the explorations of the impacts of age groups revealed that the relationship was valid.Then,the fluctuating tendencies of effective reproduction number Rt were demonstrated by using two approaches(the surveillance data and the SEIHR model)for Fuzhou COVID-19 large wave,during which high-risk group(G4 group)mainly contributed the infection scale due to high susceptibility to infection and high risks to basic diseases.Further,the sensitivity analysis using two approaches(the sensitivity index and the PRCC values)revealed that susceptibility to infection of age groups played the vital roles,while the numerical simulation showed that infection scale varied with the changes of social contacts of age groups.The results of this study claimed that the high-risk group out of the total population was concerned by the local government with the highest susceptibility to infection against COVID-19.Conclusions This study verified that the partition structure of age groups of the total population,the susceptibility to infection of age groups,the social contacts among age groups were the important contributors of infection scale.The less social contacts and adequate hospital beds for high-risk group were profitable to control the spread of COVID-19.To avoid the emergence of medical runs against new variant in the future,the policymakers from local government were suggested to decline social contacts when hospital beds were limited.

THE METAMORPHIC FEATURE,AGE AND MECHANISM OF AMUGANG GROUP IN NORTHERN TIBET

Amugang Group is distributed mainly over Amugang, Jiangai Mountain, Mayigangri,Gemuri and Qiagela,etc. lt includes Gemuri Formation and Qiagela Formation. They had even been thought of the crystalline basement of Qiangtang terrain. However, Gemuri Formation and Qiagela Formation are not alike in the protolithes, metamorphism and deformation, rock association,etc.In fact, they are different in mechanism.Gemuri Formation is composed of high\|Pressure, low\|temperature glaucophane greenschist\|faci metamorphic rocks. The petrolithes of the blueschists are glaciomarine conglomerates and basalts from the Southern Qiagtang area. The typical mineralogy include: glaucophane+ epidote + calcite +stilpnomelane and stilpnomelane+chlorite+sericite+ quartz+ glaucophane. P.T conditions for the metamorphism of blueschist are estimated to be 0 6～0 7GPa and 320～400℃.The 40 Ar/ 39 Ar dating of the crossite has yielded good plateau age of (222 5±3 7)Ma,which represents the formation of Gemuri Formation.Qiagela Formation comprises schist series, marbles, Gneisses and plagioamphiboles. The protolithes of them are a suit of argillaceous sandstones, arkoses, carbonates and mafic volcanic rocks. The Sm\|Nd isochron age of the metamorphic mafic volcanic rocks is (268 0±5 6)Ma, which shows that The age of the protolithes is early Dias. The typical mineralogy include: Muscovite+biotite+plagioclase+quartz; garnet+kyanite+ staurolite+ biotite+ muscovite+plagioclase+quartz; amphibole+ plagioclase±garnet+ quartz. They are meos\|pressure,meso\|temperature low amphibole\|faci metamorphic rocks. Qiagela Formation is coexistent with the late Triassic and the early Jurassic volcano\|magmatic arc in space and overlapped by the triassic limestones of Xiaocaka Formation. So,it is suggested that the formation of Qiagela Formation be between the late Dias and the late Triassic period. Its genesis is relative to the thermal current provided by magmatic activity.

Depositional Age, Provenance Characteristics and Tectonic Setting of the Ailaoshan Group in the Southwestern South China Block

The depositional and metamorphic ages and provenances of the Ailaoshan(ALS) Group in the Ailaoshan-Red River(ALS-RR) shear zone, southwestern South China Block(SCB), were investigated to constrain the tectonic history of the southwestern SCB. In this study, we use petrology, geochemical analysis, zircon cathodoluminescence imaging and UPb geochronology to analyse samples of quartzite, garnet-bearing two-mica schist and metapelite. The age spectra of detrital zircon grains from these metasediments show two dominant age peaks at 550–424 Ma and 876–730 Ma and two subordinate peaks at 970–955 Ma and ~2450 Ma. The youngest peak, corresponding to the early Palaeozoic, accounts for more than 20% of the total dates and constrains the deposition of the ALS Group to the Palaeozoic rather than the Palaeoproterozoic as traditionally thought. Moreover, two peaks of metamorphic ages corresponding to the Permo-Triassic and Cenozoic were also identified, and these ages document the tectonothermal events associated with the Indosinian collision between the Indochina Block and the SCB and the Himalayan collision between the Indian and Asian plates. Geochemical data suggest that the provenances of the ALS Group were dominated by continental arc and recycled metasedimentary rocks. The comparison of probability density distribution plots of the detrital zircon U-Pb age data indicates that the Neoproterozoic detritus in the ALS Group was probably derived from the arc-related Neoproterozoic intrusive bodies in the northwestern and southwestern SCB. Furthermore, the early Palaeozoic detritus might have been sourced from eroded early Palaeozoic strata and magmatic plutons in Cathaysia and volcanic rocks in the western Indochina Block.

Redefinition and Formation Age of the Tanjianshan Group in Xitieshan Region, Qinghai

The Tanjianshan Group,which was previously divided into a,b,c and d formations,has been controversial for a long time.It mainly distributes in the northern margin of Qaidam Basin and is an important early Paleozoic greenschist facies metamorphic volcanic sedimentary rock formation.Detailed field investigation and zircon LA-ICPMS U-Pb dating of the key strata suggest that the original lower part of a Formation （a-1） versus the original middle upper of d Formation （d-3 and d-4）,the original upper part of a Formation （a-2） and b Formation versus the original lower part of d Formation （d-1 and d-2） of Tanjianshan Group are contemporaneous heterotopic facies volcanicclasolite deposit,respectively.The former formations formed during the middle-late Ordovician （463-458 Ma）,while the latter ones formed in the late Ordovician （about 445 Ma）.The original c formation of Tanjianshan Group,which formed after 430 Ma,is similar to the Maoniushan Formation of Kunlun Mountains and north Qaidam Basin.According to the rules of stratigraphic division and naming,new stratum formations of Tanjianshan Group are re-built and divided into Duancenggou （O1-2td）,Zhongjiangou （O2-3tz） and Xitieshan （O3tx） formations.The original c Formation is separated from Tanjianshan Group and is renamed as the Wuminggou Formation （S3-D1W）,which shows a discordant contact with underlying Tanjianshan Group and overlying Amunike Formation （D3a）.The zircon U-Pb age frequency spectrogram of Tanjianshan Group indicates three prominent peaks of 430 Ma,460 Ma and 908 Ma,which is consistent with the metamorphic and magmatic crystallization ages obtained from para-and orthogneisses in north Qaidam HP-UHP metamorphic belt,implying that strong Caledonian and Jinningian tectonic and magmatic events have ever happened in North Qaidam.