Incidence and Management of Occupational Blood Exposure (OBE) among Medical Students at the University of Bangui

Introduction: Like healthcare workers, medical students are also exposed to a risk of accidental contamination during their hospital internships. However, they do not benefit from prevention services in the same way as workers in this sector, although they actively participate in the routine care provided to patients in the various hospital departments. The objective of our study is to determine the incidence of these accidents and their medical and administrative management among these victims (medical students) not classified in the category of workers. Materials and Method: This was a cross-sectional study carried out over three months from January 15 to March 14, 2023. The study population consisted of all medical students at the Faculty of Health Sciences at the University of Bangui. Regularly enrolled students from 2nd to 7th year, on placement in hospitals in the Central African Republic and who gave their informed consent were included. Data were collected through a self-administered questionnaire. Results: A cross-sectional study was carried out among medical students concerning the incidence and management of accidents involving exposure to blood in the Central African Republic. Of the 254 students included, three (9%) had already been correctly vaccinated against the viral hepatitis B virus, 198 (77.9%) reported still having access to personal protective equipment, 133 students (52.4%) reported being victims of OBE in the past 12 months. The main types of OBE were stings (62%), followed by liquid splashes (32%) and cuts (6%). Among the 133 victims, 92.9% carried out immediate hand disinfection or abundant eye washing, 41.9% obtained the serology of the source patient and 37% reported the accident to their supervisor. Conclusion: It is important that students benefit from better prevention and management of these accidents.

基于FireNet的古建筑火灾检测方法研究及改进

针对古建筑火灾检测需要快速、准确及实时的需求,建立了一个专门用于古建筑火灾检测的数据集,用于古建筑火灾检测的深度学习研究。利用CBAM注意力机制模块,结合多尺度特征融合,对FireNet网络进行改进,提出适用于古建筑火灾检测的轻量级FireNet-AMF网络,在FireNet数据集和本文构建的古建筑火灾检测数据集上验证了FireNet-AMF网络的火灾检测能力。与改进前的网络相比,FireNet-AMF网络在FireNet数据集上对火灾识别的准确率达到了95.08%,与原网络相比提高了1.17%,在本文构建的古建筑火灾检测数据集上的准确率达到了95.62%,比原网络提高了1.62%。该网络在保证轻量级的同时也保证了在古建筑火灾检测中较高的检测精度。

Induction System for a Fusion Reactor: Quantum Mechanics Chained up

In the quest for a sustainable and abundant energy source, nuclear fusion technology stands as a beacon of hope. This study introduces a groundbreaking quantum mechanically effective induction system designed for magnetic plasma confinement within fusion reactors. The pursuit of clean energy, essential to combat climate change, hinges on the ability to harness nuclear fusion efficiently. Traditional approaches have faced challenges in plasma stability and energy efficiency. The novel induction system presented here not only addresses these issues but also transforms fusion reactors into integrated construction systems. This innovation promises compact fusion reactors, marking a significant step toward a clean and limitless energy future, free from the constraints of traditional power sources. This revolutionary quantum induction system redefines plasma confinement in fusion reactors, unlocking clean, compact, and efficient energy production.

富碳质地质样品Re-Os同位素体系研究进展

Re-Os同位素定年技术在富有机质沉积岩、低变质沉积岩、湖相沉积物、煤、油气藏样品等富碳质地质样品的尝试和成功应用,使其成为直接厘定地层沉积时代、重大地质事件发生时限和机制、古环境重建、油气藏直接定年、油气演化过程推演等研究的关键技术手段。然而,受到富碳质地质样品中极低的Re和Os丰度、采样方式以及地质作用等因素的影响,很多样品的Re-Os等时线年龄和初始Os同位素比值精度超过10%,不能有效地评价海水Os的真实来源和地质作用程度,影响了对不同沉积体系及油气演化过程中Re和Os的化学行为和Re-Os等时线年龄地质意义的理解。由此,本文从富碳质地质样品的Re-Os化学行为和地质应用进展出发,对富碳质地质样品Re-Os同位素分析过程中的采样和取样方式、溶样方法、分离富集方式和标准物质选择四方面进行了总结和完善。指出以沉积速率为采样间距参考,通过预处理方式提高样品的均匀性,使用流程空白更低、对同位素分馏影响更小的溶样方法和分离富集方式进行Re-Os同位素分析,以基质匹配的地质标样进行数据监控可进一步提高样品Re-Os同位素分析质量,有助于不同类型富碳质地质样品Re和Os赋存机制研究、Re-Os同位素分析技术开发及地质应用拓展。

Review of Maternal Deaths over 3 and a Half Years at the Kara University Hospital Center, Northern Togo: About 65 Cases

Objective: To analyze maternal deaths, identify causes and dysfunctions leading to these deaths in order to contribute to the implementation of strategies to reduce maternal mortality at CHU Kara. Method: Cross-sectional descriptive study involving 65 cases of maternal deaths recorded at CHU-Kara from January 1, 2018 to June 30, 2021. Results: Our study focused on 65 cases of maternal deaths recorded at the maternity ward of CHU-Kara. The average age was 30 years, with a range of 15 to 45 years. They were mostly housewives (52.3%), uneducated (38.5%), multiparous (41.5%), and referred (86.2%). The causes were mainly direct obstetric causes (81.54%), with preeclampsia and its complications (28.30%) and immediate postpartum hemorrhage (20.75%) being the most common. However, uterine rupture (20.5%) and post-abortion sepsis (16.4%) were the most lethal etiologies. Delayed evacuation (46.43%), inadequate transportation (91%), and insufficient prenatal care (72.31%) were the dysfunctions before referral. Within the CHU Kara, delays in management (58.46%), unavailability of blood and labile products (18%), and insufficient monitoring were the dysfunctions identified. Ninety-five point four percent (95.4%) of the deaths were preventable. Conclusion: The magnitude of intrahospital maternal deaths, the various dysfunctions observed in the occurrence of maternal deaths before referral/evacuation and within the hospital highlight the importance of effectively implementing recommendations from audits in the fight against maternal mortality. The majority of the deaths were preventable (95.38%).

National Soil Organic Carbon Stocks Inventories under Different Mangrove Forest Types in Gabon

Gabonese’s estuary is an important coastal mangrove setting and soil plays a key role in mangrove carbon storage in mangrove forests. However, the spatial variation in soil organic carbon (SOC) storage remain unclear. To address this gap, determining the SOC spatial variation in Gabonese’s estuarine is essential for better understanding the global carbon cycle. The present study compared soil organic carbon between northern and southern sites in different mangrove forest, Rhizophora racemosa and Avicennia germinans. The results showed that the mean SOC stocks at 1 m depth were 256.28 ± 127.29 MgC ha−1. Among the different regions, SOC in northern zone was significantly (p p < 0.001). The deeper layers contained higher SOC stocks (254.62 ± 128.09 MgC ha−1) than upper layers (55.42 ± 25.37 MgC ha−1). The study highlights that low deforestation rate have led to less CO2 (705.3 Mg CO2e ha−1 - 922.62 Mg CO2e ha−1) emissions than most sediment carbon-rich mangroves in the world. These results highlight the influence of soil texture and mangrove forest types on the mangrove SOC stocks. The first national comparison of soil organic carbon stocks between mangroves and upland tropical forests indicated SOC stocks were two times more in mangroves soils (51.21 ± 45.00 MgC ha−1) than primary (20.33 ± 12.7 MgC ha−1), savanna and cropland (21.71 ± 15.10 MgC ha−1). We find that mangroves in this study emit lower dioxide-carbon equivalent emissions. This study highlights the importance of national inventories of soil organic carbon and can be used as a baseline on the role of mangroves in carbon sequestration and climate change mitigation but the variation in SOC stocks indicates the need for further national data.

Syphilis and HIV Infection among Pregnant Women Previously Screened Negative during Their First Antenetal Care Visit (ANC) at Some Selected Health Facilities in the Buea Health District, Cameroon

Syphilis and HIV are amongst the world’s most widespread diseases, particularly in low-income countries. Syphilis and HIV infections during pregnancy have been associated with numerous adverse pregnancy outcomes. Of concern now are the rising rates of congenital syphilis and HIV in Cameroon. Cameroon only mandates testing pregnant women for syphilis and HIV during their first ANC visit. This study was aimed at determining the incidence of new syphilis and HIV infections and factors associated with pregnant women who previously tested negative during their first ANC visit. A cohort design was used, where 335 pregnant women were followed up for a period from December 2019 to August 2020. A blood sample was drawn and the serum was analyzed using the WANTAI ELISA and AIDTM HIV 1 + 2 Ag/Ab ELISAPlus test methods for syphilis and HIV respectively at three intervals. A questionnaire was used to identify risk factors. Data was analyzed using SPSS 23.0. Out of the 335 pregnant women who were followed up during this study, 49 (14.6%) were later diagnosed with syphilis (32 in 2nd trimester and 17 in 3rd trimester). 54 (16.1%) were diagnosed with HIV infection (13 at two months post-1st-trimester visit, 23 in the 2nd trimester and 18 in the 3rd trimester). Lastly, 10 (2%) were co-infected with syphilis and HIV of which 8 occurred during 2nd trimester and 2 in the 3rd trimester. The factors associated with contracting new syphilis infections include;younger age group aOR (1.302, 95% CI), leaving in an urban area aOR (3.158, 95% CI), lower level of education (Primary and no formal) with aOR of (9.055, 95% CI) (P = 0.001) and (6.764, 95% CI) (P = 0.006) respectively, inadequate knowledge on the diseases aOR (2.176, 95% CI), women unaware of their partner status aOR (3.190, 95% CI). Most factors associated with contracting new HIV infections were similar to the factors associated with contracting new syphilis infections post 1st ANC visit aOR (1.174, 95% CI) and pregnant women with more than one sexual partner aOR (7.342, 95% CI) were observed for HIV infection.. There is an increased incidence of new infection of syphilis and HIV post first ANC screening in the Buea Health District, Cameroon. The need for constant education on the identifiable factors and these diseases, and screening during every ANC visit irrespective of their previous laboratory results is warranted.

Obstacles to the Integrated Care of Children Aged 6 to 59 Months Suffering from Acute and Severe Malnutrition at the Chu-Me and HATC of N’Djamena/Chad

Introduction: the problem of Severe Acute Malnutrition (SAM) and its consequences concern and challenge all social actors worldwide. The objective of the study was to identify the real obstacles that actors face in the integrated management of children aged 6 - 59 months suffering from SAM at the University Hospital of Mother and Child (CHUME) and the Chad-China Friendship Hospital (HATC) of N’Djamena. Methodology: this is a cross-sectional descriptive and interpretative study conducted from January to October 2023 at the CHUME and HATC of N’Djamena. It is based on questionnaires and direct observation of two hundred and thirty-six (236) parents or guardians of malnourished children admitted to these health facilities. All 236 agreed to participate freely in this study. Results: it appears from this study that the obstacles to the integrated management of malnourished children were: poor care-care relationship (26.7%) permanent product breaks (22.9%), the direct costs of services ranged from 30,000 to 60,000 FCFA (41.53%), drugs used for the treatment of patients came from the street (66.10%), malaria and anemia occupy an important place (27.5%), 57.2% respondents had monthly income below 60,000 CFAF. Conclusion: the present study carried out has identified the real bottlenecks to the integrated management of children suffering from SAM in the therapeutic nutritional units of the city of N’Djamena. .

Analysis of the Quality of Physical and Chemical Parameters of Groundwater in Three Localities in the Sub-Prefecture of Zanzra (Ivory Coast)

The availability of groundwater of acceptable quality has become a difficult challenge to meet in many countries, particularly Côte d’Ivoire. The State of Côte d’Ivoire and rural populations are building hydraulic infrastructure for this purpose. However, the quality of water coming from these infrastructures remains to be determined. This study therefore aims to analyze certain physicochemical parameters of the groundwater of Gloazra, Kouezra and Trahonfla. These are temperature, pH, electrical conductivity, TDS, salinity level, hardness, alkalinity, chloride content and bicarbonate. To determine the pH, electrical conductivity, temperature, TDS, and salinity rate, an electrochemical analysis was carried out. The titrimetric analysis made it possible to determine the chloride and bicarbonate content, alkalinity, and hardness. The results indicate that the studied groundwater is soft and acidic with good mineralization. This water does not present a health hazard to consumers but can affect hydraulic equipment and household containers.

Prevalence of Tick Infestations and Tick-Borne Diseases in Cattle in Cameroon

Ticks induce huge production and economic losses in the livestock industry and create serious environmental, animal and human health problems. The study was carried out to characterize tick species and determine the prevalence of tick infestation and tick-borne diseases in cattle in Cameroon. Tick and blood samples were collected from a total of 742 animals and analyzed to determine the type of tick and haemoparasites using standard procedures. Overall, four tick species namely Amblyomma variegatum (75.09%), Rhipicephalus microplus (19.43%), Rhipicephalus decoloratus (0.88%) and Hyalomma marginatum (0.18%) and six blood disease agents including Anapalasma marginale (11.29%), Ehrlichia ruminantium (3.52%), Babesia bovis (1.32%), Babesia major (0.44%), Anaplasma phagocytophilum (0.29%) and Dermatophilus congolensis (3.37%). Various co-infections were recorded and the predominant associations were Amblyomma variegatum-Rhipicephalus microplus (4.06%) and Amblyomma variegatum-Hyalomma marginatum (0.36%);Anaplasma-Ehrlichia (12%), Anaplasma-Dematophylus (8%), Babesia-Anaplasma-Ehrlichia (14%) and Babesia-Anaplasma-Ehrlichia-Dermato-phylus (5%). Breed, sex, age and locality significantly influenced the rate of tick infestation while locality, breed and age significantly influenced the detection of blood disease agents in the study.

Total Indicative Dose Determination in Water from the North Riviera Well Field of SODECI in Abidjan, Cote d’Ivoire

The Uranium-238 (238U), Thorium-232 (232Th) families and Potassium-40 (40K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of 238U, 232Th and 40K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides238U, 232Th, and 40K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.

贵州正安县奥陶系—志留系界线碳质泥岩Re-Os同位素精确厘定及其古环境反演

我国上扬子地台地区在奥陶系—志留系之交广泛发育蕴含丰富页岩气资源的五峰组—龙马溪组富有机质沉积岩。采用Re-Os同位素体系对该套沉积地层进行研究,不仅能得到精确的地层沉积年龄,同时根据Re、Os元素的富集机制,对该时期沉积环境进行有效反演,可以为这一阶段发生的地球历史上第二大规模的生物绝灭事件的触发机制提供更合理的解释。本文在贵州正安县班竹1井岩心采集11件碳质泥岩样品,岩心样品连续且完整跨越奥陶系五峰组—志留系龙马溪组界线地层,通过对该样品开展高精度Re-Os同位素研究,获得了奥陶系—志留系地层界线Re-Os同位素年龄为443.68±6.24Ma[2σ,n=7,(187 Os/188 Os)i=0.699±0.019,MSWD=0.55],其结果与国际地层委员会发布的年龄(443.7±1.5Ma)高度一致,为奥陶系—志留系界线年龄提供了直接、准确的年龄依据。Os同位素特征反映了大量陆源碎屑参与成岩过程、多期火山活动的发生及冰期向间冰期的转换。连续沉积地层Re-Os同位素特征的变化反映了研究区奥陶系五峰组—志留系龙马溪组沉积环境经历富氧—缺氧—富氧的变化,指示赫南特期冰川事件和火山喷发共同造成了生物大绝灭并促进了有机质的富集,为五峰组—龙马溪组富有机质沉积岩提供了生烃潜力。

沥青Re-Os同位素年龄地质意义解读

Re、Os亲有机质的特性使得Re-Os同位素在富有机质地质样品中得到了广泛应用;沥青由大量重组分有机质组成,对Re、Os具有较强的富集能力,并且沥青样品中Re-Os同位素封闭性较好,因此沥青Re-Os同位素已经成为当今国际上研究的一个热点。然而,沥青Re-Os同位素年龄究竟是代表烃源岩的沉积时代、油气成藏时代、还是油气藏破坏后油气运移时代,至今还没有明确的定论。本文对新疆乌尔禾沥青矿、四川矿山梁沥青矿样品进行了Re-Os同位素分析,结果显示,乌尔禾沥青矿Re-Os同位素年龄为269±9Ma,老于周围白垩系砂岩地层沉积时代,Os同位素初始比值^(187) Os/^(188 )Os(Os i)为0.367±0.028,小于二叠纪海水的Os i同位素比值,表明得到的乌尔禾沥青Re-Os同位素年龄反映的是乌尔禾油气藏的成藏时代。矿山梁沥青矿Re-Os同位素年龄为537.3±5.2Ma,老于围岩(寒武系、奥陶系、志留系地层)沉积时代,Os同位素初始比值为0.716±0.028,与早寒武世海水的Os_(i)同位素比值一致,表明得到的矿山梁沥青Re-Os同位素年龄代表烃源岩的沉积时代。结合前人发表的沥青Re-Os同位素数据,沥青Re-Os同位素等时线年龄可能反映烃源岩的沉积时代,也可能代表油气藏的形成时代,这主要取决于油气成藏过程中,具有不同Re-Os同位素特征的原油是否能够混合均匀。沥青Re-Os同位素年龄能否反映油气藏遭受破坏而发生运移的时代,主要取决于沥青的热演化程度以及油气藏破坏过程中原油的混合程度。沥青Re-Os同位素研究不仅能够为油气成藏时代的厘定提供了一种有力的工具,而且对于油气烃源岩的判别以及油气成因研究都具有十分重要的意义。

峨眉蔷薇Ro-DREB1C的克隆与生物信息学分析

【目的】丰富月季CBF基因研究的基础数据库,对峨眉蔷薇原变种(Rosa omeiensis Rolfe f. omeiensis) CBF/DREB基因进行克隆和生物信息学分析。【方法】设计特异引物克隆Ro-DREB1C基因的完整CDS区及部分5'端和3'端UTR区序列,使用生物信息学软件分析该基因编码蛋白的理化性质、二三级结构和预测亚细胞定位,构建系统进化树确定Ro-DREB1C隶属的基因家族。【结果】获得峨眉蔷薇Ro-DREB1C基因CDS区603 bp,Gen Bank登录号为KX397104,编码200个氨基酸。蛋白质分子式为C968H1539N263O299S11,其中丝氨酸、亮氨酸和丙氨酸的频率较高,分别占11. 5%、11. 0%和9. 5%,属于不稳定类、弱酸性、亲水蛋白;二级结构以无规则卷曲(71. 5%)为主,不能被归入明确的二级结构如折叠片或螺旋的多肽区段;三级结构预测模板为d1gcca,识别预测序列范围为59～119,识别长度61 bp;该蛋白质无跨膜区和信号肽的存在,亚细胞定位Ro-DREB1C分布在细胞核中的分布最多。与RhCBF比较:Ro-DREB1C的编码区没有单碱基的缺失或插入,共存在21个潜在SNP位点,导致10个差异氨基酸。系统进化分析表明Ro-DREB1C隶属于AP2家族DREB亚家族A-1亚组成员。【结论】峨眉蔷薇可作为优秀的月季耐寒育种材料加以保存和利用。

Preparation of ZrB_2-SiC Powders via Carbothermal Reduction of Zircon and Prediction of Product Composition by Back-Propagation Artificial Neural Network

Phase pure ZrB2-SiC composite powders were prepared after 1 450℃/3 h via carbothermal reduction route,by using ZrSiO4,B2O3 and carbon as the raw materials.The influences of firing temperature as well as the type and amount of additive on the phase composition of final products were detailedly investigated.The results indicated that the onset formation temperature of ZrB2-SiC was reduced to 1 400℃by the present conditions,and oxide additive（including CoSO4·7H2O,Y2O3 and TiO2）was effective in enhancing the decomposition of raw ZrSiO4,therefore accelerating the synthesis of ZrB2-SiC.Moreover,microstructural observation showed that the as-prepared ZrB2 and SiC respectively had well-defined hexagonal columnar and fibrous morphology.Furthermore,the methodology of back-propagation artificial neural networks（BP-ANNs）was adopted to establish a model for predicting the reaction extent（e g,the content of ZrB2-SiC in final product）in terms of various processing conditions.The results predicted by the as-established BP-ANNs model matched well with that of testing experiment（with a mean square error in 10^（-3） degree）,verifying good effectiveness of the proposed strategy.

滇中昆阳磷矿成矿时代及沉积环境Re-Os同位素示踪研究

川滇黔地区下寒武地层中广泛分布一系列磷矿床,其中滇中昆阳磷矿是我国下寒武统梅树村期黑色页岩中规模最大的海相沉积型磷矿床,其成矿时代以及沉积环境对于矿床成因研究以及区域找矿具有重要意义。Re-Os同位素不仅能够对富有机质沉积岩地层进行直接定年,而且还能为物质来源及沉积环境示踪提供一种有效的技术手段。本文对昆阳磷矿中谊村段磷块岩和石岩头段黑色页岩开展热表面电离质谱法Re-Os同位素示踪及定年探索性研究,获得了石岩头段黑色页岩Re-Os等时线年龄为521.9±5.4Ma,直接限定了昆阳磷矿黑色页岩沉积时代。磷块岩187Os/188Os初始比值为0.6576~0.7671,黑色页岩187Os/188Os初始比值为0.887,另外磷块岩187Re/188Os值为2.582~240.5,而上覆黑色页岩187Re/188Os值为96.24~341.8,而且磷块岩、黑色页岩微量元素δEu和δCe值在垂向剖面上显示由低变高的变化特征,这些证据表明昆阳磷矿形成正处于大陆快速剥蚀时期,指示大量陆源碎屑汇入海洋参与成岩-成矿过程。综合前人研究,本文认为,在寒武纪,大气氧含量快速升高,加剧陆壳风化,大量高放射性陆源Os的输入造成该时期内187Os/188Os初始比值逐渐升高。另外由于全球海平面上升,导致滇中早寒武世梅树村组沉积期古海洋环境由浅水氧化向深水还原逐渐过渡,而昆阳磷矿形成于该阶段海进旋回沉积早期。

红掌细菌性疫病病原菌遗传多样性的RAPD和Rep-PCR分析

由地毯草黄单胞菌花叶万年青致病变种引起的细菌性疫病是红掌生产中最具破坏性的病害。本研究对来自全国8个省市主产区的93个红掌细菌性疫病菌株,采用RAPD和Rep-PCR(ERIC、BOX、REP)分子标记进行了遗传多样性分析。筛选出的13个RAPD引物共扩增出131个清晰、重复性好的条带,而Rep-PCR共扩增出65个条带,所有位点多态性比率为100%。基于RAPD和Rep-PCR结果计算的群体遗传距离显著相关,综合2种标记类型的分型结果进行UPGMA聚类分析,表明我国红掌细菌性疫病具有高度的遗传多样性,在遗传相似性系数范围0.519 1~0.984 7,在0.63水平时可以将所有菌株划分为3个组群,分别包括58、28、7个个体,病菌群体的遗传多样性与其寄主品种、地理来源没有明显相关性。本研究为红掌细菌性疫病监测和抗病育种提供了科学依据。

中国斑岩铜(钼)矿床中辉钼矿Re含量变化及控制因素

铼作为战略性关键金属之一,越来越受到人们的关注。Re主要以类质同象的形式赋存在辉钼矿中,然而,不同成因、不同类型矿床的辉钼矿中Re含量差异较大。在钨、锡矿床中Re含量较低,在斑岩型铜(钼)矿床中Re含量较高,后者是全球Re资源的主要载体。前人对于辉钼矿中Re元素的研究主要基于Re-Os同位素年代学,而对于不同区域、不同时代、不同类型斑岩型铜矿床中辉钼矿Re含量的变化规律及其控制因素的研究较少。文章通过汇总前人发表的斑岩型铜(钼)矿床的Re-Os同位素数据,从含矿斑岩的Sr、Nd、Hf等数据与辉钼矿中平均Re含量的关系等角度,探讨了其变化规律及控制因素。结果表明:中国斑岩型铜(钼)中Re含量随着成矿物质从地幔到地壳,依次减少;成矿流体的氧逸度、辉钼矿的产状、与其伴生的硫化物种类及不同的成矿阶段等因素共同控制了辉钼矿中Re的含量。

柯萨奇B组3型病毒SYBR GreenⅠRT-PCR检测方法的建立

目的建立一种灵敏、特异的柯萨奇B组3型(CV-B3)病原SYBR GreenⅠRT-PCR实时荧光定量检测方法,用于快速、准确地检测CV-B3。方法设计柯萨奇B组病毒通用引物以及VP1基因的T7启动子特异性引物,以体外转录获得的RNA为标准品,绘制标准曲线,建立CV-B3的荧光定量PCR检测方法;对检测方法的敏感度、特异性、重复性进行评价。结果该检测方法在10~10^(9)拷贝/微升范围内具有良好的扩增效率和线性关系,最低检测限为10拷贝/微升,标准曲线r^(2)=0.999,扩增效率为95.7%;且对柯萨奇病毒A组6型(CV-A6)、柯萨奇病毒A组10型(CV-A10)、肠道病毒71型(EV-71)均无交叉反应,重复性实验变异系数(CV%)<2%。结论本实验建立的检测方法敏感度较高,同时具备良好的特异性及重复性,可用于CV-B3病原的临床及实验室样本的定性定量检测。

白刺链霉菌(Streptomyces albospinus)CT205产环己酰亚胺含量测定方法的建立

建立白刺链霉菌(Streptomyces albospinus)CT205代谢产环己酰亚胺含量的检测方法,为菌株CT205的开发利用提供技术支持。采用高效液相色谱法(HPLC)、生物活性法和分光光度法等三种检测手段分别测定菌株CT205发酵上清液及粗提物中活性物质环己酰亚胺(Cycloheximide)的含量。三种方法测定环己酰亚胺标准品均具有较好的线性关系,其中相关系数R_(HPLC)^(2)法(0.9992)>R_(生物活性法)^(2)(0.9937)≈R_(分光光度法)^(2)(0.9965)。HPLC法及生物活性法分别测定CT205发酵液及粗提物中活性物质含量分别为72.87、1555.70及66.15、1259.00μg/mL,HPLC法与生物活性法测定的发酵上清液中活性物质含量误差在+6.72μg/mL。HPLC检测方法的准确性及灵敏度均高于生物活性法,适用于样品含量的准确测定,生物活性法适用于菌株诱变筛选及条件优化实验产生的大批量样品的测定及比较,分光光度法不适用检测杂质含量较多的样品。