期刊文献+
共找到17,901篇文章
< 1 2 250 >
每页显示 20 50 100
Slowing down of the summer Southern Hemisphere Annular Mode trend against the background of ozone recovery
1
作者 Fei Zheng 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期1-8,共8页
20世纪末期,南半球热带外地区经历了显著的气候变化,包括夏季南半球环状模(SAM)的显著上升趋势,伴随着南极半岛的增暖和别林斯高晋海的海冰融化.这些趋势主要是由20世纪末期南极平流层臭氧消耗所驱动的.本文发现,自2001年左右以来,在南... 20世纪末期,南半球热带外地区经历了显著的气候变化,包括夏季南半球环状模(SAM)的显著上升趋势,伴随着南极半岛的增暖和别林斯高晋海的海冰融化.这些趋势主要是由20世纪末期南极平流层臭氧消耗所驱动的.本文发现,自2001年左右以来,在南极平流层臭氧恢复的背景下,观测到的夏季SAM的上升趋势已经趋于平缓,验证了前人利用数值模拟预测的夏季SAM上升趋势减缓现象,与SAM在臭氧恢复后趋势只减缓但没有逆转不同,南极地表气温和海冰的趋势发生了逆转.南极半岛由变暖趋势转为降温趋势,别林斯高晋海域的海冰由融化趋势转为增多趋势. 展开更多
关键词 南半球环状模 南极臭氧损耗 南极臭氧恢复
下载PDF
Pattern of Referral of Obstetric Patients at a Tertiary Care Hospital in Southern Nigeria
2
作者 Osita Celestine John Justina Omoikhefe Alegbeleye 《Advances in Reproductive Sciences》 CAS 2024年第2期116-124,共9页
Background: Health challenges that are difficult to manage at primary health centres should be referred to secondary health facilities, and if untreated, to the tertiary hospitals. A good referral should include the p... Background: Health challenges that are difficult to manage at primary health centres should be referred to secondary health facilities, and if untreated, to the tertiary hospitals. A good referral should include the patient’s biography, such as age, gender, tribe, religion, occupation, medical history, the reason for the referral, treatments received, and clinical diagnosis. Objectives: To evaluate the referral patterns, indications for referrals, and feto-maternal outcomes for obstetric patients who were referred to the University of Port Harcourt Teaching Hospital. Materials and Methods: A prospective study of patients admitted to the Obstetric unit from January 1, 2021, to December 31, 2022. Data was collected from patients while on admission or clinic visits and recorded in an excel spread sheet. Data was analyzed with the Statistical Package for Social Sciences (SPSS) version 25. Results: Of the 3469 patients were admitted to the obstetric unit, 1476 and 1993 were admitted in 2021 and 2022, respectively. Most (70.35%) of the patients were in the 20-34 years age group, parity 1-4 was the most frequent (66.49%), while 85.39% of patients were booked. 10.46% of the booked patients were referred from other facilities, whereas 89.54% of patients were booked at our facility from the onset. Most common indications of referrals were previous caesarean section (CS) at term (40.09%) and hypertensive disorders of pregnancy (17.59%). The outcome for 2021 indicated 17 maternal deaths, 132 fetal deaths and 1010 live births, giving maternal mortality ratio (MMR) as 1810.44 per 100,000 live births and perinatal mortality ratio (PMR) of 130.7 per 1000 births respectively. In 2022, there were 17 maternal deaths, 130 fetal deaths and 1297 deliveries, giving a MMR of 1399 per 100,000 live births and a PMR of 100.2 per 1000 births. Conclusion: The pattern of referral among obstetric patients in this study shows that a lot of the patients do not get adequate care at the lower cadre of the referral system, hence adequate facilities should be made available in primary and secondary health centres to tackle obstetric emergencies. 展开更多
关键词 REFERRAL PATTERN OBSTETRICS southern NIGERIA
下载PDF
Changing Nasopharyngeal Carcinoma Survival in Southern China during 2000-2015: Results of a Retrospective Cohort Study
3
作者 Xiao Zhou Hao Zheng 《Journal of Biosciences and Medicines》 2024年第10期258-269,共12页
Objective: Around 50% of new nasopharyngeal carcinoma (NPC) cases come from China. The present study aimed to update the surveillance of NPC survival in southern China, and investigate the survival disparities between... Objective: Around 50% of new nasopharyngeal carcinoma (NPC) cases come from China. The present study aimed to update the surveillance of NPC survival in southern China, and investigate the survival disparities between sexes within this patient population. Methods: Patients diagnosed with primary and invasive NPC between 2000 and 2015 were included in this study. Data on demographics, diagnosis, and follow-up to December 2020 were collected. Patients were stratified by diagnosis period, sex, and age at diagnosis. Survival analysis employed cohort and Life Table methods, Kaplan-Meier curves, log-rank tests, and Cox regression. Results: The study included 32,901 patients, of whom 69.6% were males. The overall 5-year survival rate rose from 69.6% in 2000-2003 to 83.3% in 2013-2015, with a consistent average increase of 3.3% every 3 years. For males, the 5-year survival rate increased from 66.3% to 82.0%, faster than females. Kaplan-Meier curves demonstrated a significantly higher survival rate for females than males, and subgroup analysis confirmed this advantage. The Cox proportional hazards model confirmed the lower mortality risk for females (HR 0.75, 95% CI: 0.71 - 0.78), patients with younger ages at diagnosis, and patients diagnosed in more recent years (All P Conclusions: The 5-year survival rate for NPC patients in southern China has significantly and steadily improved from 2000 to 2015, indicating the improved quality of cancer care in China. The survival advantage of female patients is not limited to younger patients but is also observed in postmenopausal patients, despite the gradual narrowing of the gender gap. 展开更多
关键词 Nasopharyngeal Carcinoma SURVIVAL Sex Difference southern China FEMALE PROGNOSIS
下载PDF
Distribution of Atmospheric Pollution in Southern Benin
4
作者 Dossou-Gbete Sèdami Codjo Joël Kpadonou Dominique +5 位作者 Gbaguidi An Magloire Elegbede Vitalique Saizonou Kpèssou Virtus Mickael Youssao Abdou Karim Alassane Dovonon Firmin Léonce Vodounnon Armand 《Open Journal of Air Pollution》 2024年第1期23-55,共33页
This study focuses on air quality in southern Benin in order to show public authorities what the Beninese populations are exposed to for efficient decision-making. Two sampling campaigns were carried out, one in the w... This study focuses on air quality in southern Benin in order to show public authorities what the Beninese populations are exposed to for efficient decision-making. Two sampling campaigns were carried out, one in the wet period and the other in the dry season. The measurements were taken using a monitor called an “Air Quality Monitor”. For data processing, the multiple comparison methods of Dun (1961) and the Wilcoxon test were used. To maintain legitimacy, all spatial data were included in the official cartographic repository of Benin: WGS 1984, Transverse Mercator Universe Projection (UTM), Zone 31 North. The Moran statistic was used to measure the levels of spatial autocorrelation of the variables studied and to test the significance. In order to locate the spatial subsets, the local spatial association indices of Anselin Local Moran and Getis-Ord, Gi* were used. In terms of results, on the 13 monitoring sites and the 8 parameters chosen to determine air quality, we do not note any significant inter-seasonal difference. Of the eight parameters, only three parameters present spatial autocorrelation leading to predictions of ambient air quality over the entire study area based on the distance separating the points, namely, PM<sub>2.5</sub>, PM<sub>10</sub> and ambient air quality index (AQI). The localities affected by atmospheric pollution in South Benin are located in the south-western part of Benin, headed by Cotonou, which is heavily polluted by CO<sub>2</sub>, TCOV, PM<sub>10</sub> and PM<sub>2.5</sub>. 展开更多
关键词 Spatial Distribution Atmospheric Pollutants southern Benin
下载PDF
Evaluation of Human Impacts on Bartlett Pond Ecosystem, Laredo, Southern Texas, USA, through Empirical Modeling
5
作者 Maya P. Bhatt Amede Rubio +6 位作者 Ganesh B. Malla Cristobal Lopez Virginia Morales Erick Vazquez Cano David Marquez Orlando Berumen Alvarez Alfred Addo-Mensah 《Journal of Environmental Protection》 2024年第4期497-526,共30页
The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond... The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond. Two types of fish (bass and tilapia) were also sampled to see the trace element accumulation in different parts of their body. The concentrations of trace elements in water samples were found in the following order: Fe &Gt;Sb > Pb > As &Gt;Co > Tl > Cr > Cd within Bartlett Pond. Overall, the water quality of the pond is unacceptable for drinking and any other purposes as trace element concentrations (e.g. As, Cd, Co, Cr, Pb, Fe, Sb and Tl) are exceedingly higher (several fold) than the WHO and US EPA guidelines. Predictive and correlation analysis shows that most trace elements exhibit a strong positive correlation among them indicating the same anthropogenic sources and biogeochemical processes regulate these trace elements within the pond. Distributions of the trace elements in water exhibit different shapes mostly as positively skewed distribution for As, Cd, Co, Cr, and Tl, symmetrical distribution for Fe and almost symmetrical distribution for Pb and Sb. Concentrations of As, Co and Tl accumulated much higher in different parts of the Bass than Tilapia fish. The concentrations of As, Tl, Co, and Sb appeared significantly higher in different parts of the body of both Bass and Tilapia than the maximum SRM certified values. Accumulation of these contaminants in fish tissues pose increased health risks to humans who consume these contaminated fish although fishing is prohibited. Anthropogenic activities in the region primarily degrade the whole pond ecosystem ecology of the Bartlett Pond and waters of this pond to be not recommended for any use. These findings may be useful for the scientific community and concerned authorities to improve understanding about these precious natural resources and conservation of the ecosystem ecology. 展开更多
关键词 Trace Elements Bartlett Pond Laredo southern Texas WETLANDS Ecosystem Ecology
下载PDF
Application of Machine Learning for Flood Prediction and Evaluation in Southern Nigeria
6
作者 Emeka Bright Ogbuene Chukwumeuche Ambrose Eze +9 位作者 Obianuju Getrude Aloh Andrew Monday Oroke Damian Onuora Udegbunam Josiah Chukwuemeka Ogbuka Fred Emeka Achoru Vivian Amarachi Ozorme Obianuju Anwara Ikechukwu Chukwunonyelum Anthonia Nneka Nebo Obiageli Jacinta Okolo 《Atmospheric and Climate Sciences》 2024年第3期299-316,共18页
This study explored the application of machine learning techniques for flood prediction and analysis in southern Nigeria. Machine learning is an artificial intelligence technique that uses computer-based instructions ... This study explored the application of machine learning techniques for flood prediction and analysis in southern Nigeria. Machine learning is an artificial intelligence technique that uses computer-based instructions to analyze and transform data into useful information to enable systems to make predictions. Traditional methods of flood prediction and analysis often fall short of providing accurate and timely information for effective disaster management. More so, numerical forecasting of flood disasters in the 19th century is not very accurate due to its inability to simplify complex atmospheric dynamics into simple equations. Here, we used Machine learning (ML) techniques including Random Forest (RF), Logistic Regression (LR), Naïve Bayes (NB), Support Vector Machine (SVM), and Neural Networks (NN) to model the complex physical processes that cause floods. The dataset contains 59 cases with the goal feature “Event-Type”, including 39 cases of floods and 20 cases of flood/rainstorms. Based on comparison of assessment metrics from models created using historical records, the result shows that NB performed better than all other techniques, followed by RF. The developed model can be used to predict the frequency of flood incidents. The majority of flood scenarios demonstrate that the event poses a significant risk to people’s lives. Therefore, each of the emergency response elements requires adequate knowledge of the flood incidences, continuous early warning service and accurate prediction model. This study can expand knowledge and research on flood predictive modeling in vulnerable areas to inform effective and sustainable contingency planning, policy, and management actions on flood disaster incidents, especially in other technologically underdeveloped settings. 展开更多
关键词 Machine Learning FLOOD PREDICTION EVALUATION southern Nigeria
下载PDF
El Niño-Southern Oscillation (ENSO) Variations and Climate Changes Worldwide
7
作者 Marilia Hagen Anibal Azevedo 《Atmospheric and Climate Sciences》 2024年第2期233-249,共17页
This investigation aims to study the El-Niño-Southern Oscillation (ENSO) events in these three phases: El Niño, La Niña, and neutral. Warm and cold events relate to the Spring/Summer seasons. This paper... This investigation aims to study the El-Niño-Southern Oscillation (ENSO) events in these three phases: El Niño, La Niña, and neutral. Warm and cold events relate to the Spring/Summer seasons. This paper will search for connections between the ENSO events and climate anomalies worldwide. There is some speculation that those events would be necessary for the climate anomalies observed worldwide. After analyzing the data from the reports to the ENSO, it shows almost periodicity from 1950-2023. We emphasized the occurrence of El Niño two years, when it was most prominent, and the climate anomalies (following NOAA maps), 2015 and 2023. The results indicated that the observed climate anomalies couldn’t be linked to the abnormal events observed. The worldwide temperatures in those years enhanced mostly in 2023. It shows an abnormal behavior compared with all the years scrutinized and analyzed since the records began. Therefore, there must be unknown factors beyond ENSO that rule the worldwide temperatures and the climate anomalies observed. 展开更多
关键词 ENSO southern Oscillation El Niño Climate Anomalies
下载PDF
Correlation of Rainfall Anomalies in Rwanda from September to December (SOND) with Indian Ocean Dipole (IOD) and El Nino Southern Oscillation (ENSO) Events
8
作者 Frank Rusanganwa Ling Zhang +2 位作者 Jonah Kazora Joseph Ndakize Sebaziga Samuel Ekwacu 《Journal of Geoscience and Environment Protection》 2024年第6期115-134,共20页
Understanding the relationship between rainfall anomalies and large-scale systems is critical for driving adaptation and mitigation strategies in socioeconomic sectors. This study therefore aims primarily to investiga... Understanding the relationship between rainfall anomalies and large-scale systems is critical for driving adaptation and mitigation strategies in socioeconomic sectors. This study therefore aims primarily to investigate the correlation between rainfall anomalies in Rwanda during the months of September to December (SOND) with the occurrences of Indian Ocean Dipole (IOD) and El Nino Southern Oscillation (ENSO) events. The study is useful for early warning and forecasting of negative effects associated with extreme rainfall anomalies across the country, using Climate Hazards Group InfraRed Precipitation with Station (CHIRPS), the National Centers for Environmental Prediction (NCEP) National Center for Atmospheric Research (NCAR) reanalysis sea surface temperature and ERA5 reanalysis datasets, during the period of 1983-2021. Both empirical orthogonal function (EOF), correlation analysis and composite analysis were used to delineate variability, relationship and the related atmospheric circulation between Rwanda seasonal rainfall September to December (SOND) with Indian Ocean Dipole (IOD) and El-Nino Southern Oscillation (ENSO). The results for Empirical Orthogonal Function (EOF) for the reconstructed rainfall data set showed three modes. EOF-1, EOF-2 and EOF-3 with their total variance of 63.6%, 16.5% and 4.8%, Indian ocean dipole (IOD) events resulted to a strong positive correlation of rainfall anomalies and Dipole model index (DMI) (r = 0.42, p value = 0.001, DF = 37) significant at 95% confidence level. The composite analysis for the reanalysis dataset was carried out to show the circulation patterns during four different events correlated with September to December seasonal rainfall in Rwanda using T-test at 95% confidence level. Wind anomaly revealed that there was a convergence of south westerly winds and easterly wind over the study area during positive Indian Ocean Diploe (PIOD) and PIOD with El Nino concurrence event years. The finding of this study will contribute to the enhancement of SOND seasonal rainfall forecasting and the reduction of vulnerability during IOD (ENSO) event years. 展开更多
关键词 CORRELATION Rainfall Anomalies Rwanda Indian Ocean Dipole El Nino southern Oscillation
下载PDF
Wavelet Multiview-Based Hybrid Deep Learning Model for Forecasting El Niño-Southern Oscillation Cycles
9
作者 Winston Zhou Xiaodi Wang 《Atmospheric and Climate Sciences》 2024年第4期450-473,共24页
The El Niño-Southern Oscillation (ENSO) is a significant climate phenomenon with far-reaching impacts on global weather patterns, ecosystems, and economies. This study aims to enhance ENSO forecasting with the Ex... The El Niño-Southern Oscillation (ENSO) is a significant climate phenomenon with far-reaching impacts on global weather patterns, ecosystems, and economies. This study aims to enhance ENSO forecasting with the Extended Reconstruction Sea Surface Temperature v5 (ERSSTv5) climate model. The M-band discrete wavelet transforms (DWT) are utilized to capture multi-scale temporal and spatial features effectively. Long-short term memory (LSTM) autoencoders are also used to capture significant spatial and temporal patterns in sea surface temperature (SST) anomaly data. Deep learning techniques such as the convolutional neural networks (CNN) are used with non-image and image time series data. We also employ parallel computing in a various support vector regression (SVR) approximators to enhance accuracy. Preliminary results indicate that this hybrid model effectively identifies key precursors and patterns associated with El Niño events, surpassing traditional forecasting methods. Results of the hybrid model produce a correlation of 0.93 in 4-month lagged forecasting of the Oceanic Niño Index (ONI)—indicative of high success rate of the model. Future work will focus on evaluating the model’s performance using additional reanalysis datasets and other methods of deep learning to further refine its robustness and applicability. We propose wavelet-based deep learning models which have potential to shine a light on achieving United Nations’ 2030 Agenda for Sustainable Development’s goal 13: “Climate Action”, as an innovation with potential in improving time series image forecasting in all fields. 展开更多
关键词 El Niño-southern Oscillation (ENSO) Autoencoders Discrete Wavelet Transform (DWT) Convolutional Neural Network (CNN) Support Vector Regression (SVR)
下载PDF
近江牡蛎Hsc70蛋白基因cDNA片段的克隆及Southern杂交和RT-PCR分析 被引量:12
10
作者 张其中 吴信忠 +1 位作者 高劲松 潘金培 《动物学报》 SCIE CAS CSCD 北大核心 2003年第5期708-712,共5页
In order to elucidate the molecular mechanisms of the oyster (Crassostrea ariakensis) against adverse stimulating factors, we cloned and sequenced a partial cDNA encoding a 70 kDa heat shock cognate protein (Hsc70) fr... In order to elucidate the molecular mechanisms of the oyster (Crassostrea ariakensis) against adverse stimulating factors, we cloned and sequenced a partial cDNA encoding a 70 kDa heat shock cognate protein (Hsc70) from the oyster. The live oysters were obtained from Chengcun, Yangxi County, Guangdong Province, China. Various tissues, including mantle, gills, adductor muscle, heart and blood cells, were respectively collected from 5 untreated live oysters or treated ones at 36℃ for 1 5 hours, and immediately frozen in liquid nitrogen except for the blood cells which were suspended with Trizol Reagent after centrifugation ( 12 000 r/min for 30 s) and stored at -20℃. Total RNA was isolated using Trizol Reagent according to the manufacture’s instructions. The first strand cDNA was synthesized using reverse transcriptase Superscript Ⅱ according to the manufacture’s instructions. The primers were designed from a conserved region of C. gigas Hsc70 cDNA sequence (GeneBank accession No. AF144646). The polymerase chain reaction (PCR) was performed for 30 cycles with denaturation at 94℃ for 30 s, annealing at 49℃ for 40 s, and elongation at 72℃ for 30 s. The product was cloned to pGEM T easy vector and sequenced. It is 509 base pairs (bp) and possesses 94% identity with the cDNA encoding C. gigas Hsc70 using Blastn. This homology was strongly confirmed by amino acid sequence comparison using the Blastx (99%). The 509 bp fragment was labeled with α 32 pdCTP and a random primer DNA labeling kit and employed as a probe to perform Southern blotting, the result demonstrated that the cDNA came from a partial mRNA transcript of C. ariakensis genomic DNA gene. The polymerase chain reaction (PCR) was carried out to investigate the expression of Hsc70, Using the cDNAs of several tissues, such as gills (heat shocked), mantle, adductor muscle (heat shocked), heart, blood cells (one sample with heat shock for 1 5 hours at 36℃ and another without any stimulus). The PCR results revealed that Hsc70 transcripts could be detected in all the tissues analyzed and greatly increased in the tissues with heat shock. The results showed that the Hsc70 is ubiquitously and constitutively expressed but can be stimulated by heat shock. All the facts above firmly established that the cloned cDNA fragment was a part of the cDNA encoding a Hsc70 protein in the oyster C. ariakensis . 展开更多
关键词 近江牡蛎 Hsc70蛋白基因 CDNA片段 克隆 southern杂交 RT-PCR分析
下载PDF
黄瓜抗病基因类似序列(RGA)的同源性分析和Southern鉴定 被引量:13
11
作者 丁国华 池春玉 +1 位作者 周秀艳 秦智伟 《园艺学报》 CAS CSCD 北大核心 2007年第2期355-360,共6页
使用ClustalW和DNAMAN3.0分析了本实验室克隆的15个黄瓜抗病基因类似序列(RGA)之间以及与烟草的N基因、亚麻的L6基因和拟南芥的RPS2基因之间的同源性,并对这些RGA进行了PCR和Southern验证与分析。结果表明:15个黄瓜RGA中,核苷酸序列同... 使用ClustalW和DNAMAN3.0分析了本实验室克隆的15个黄瓜抗病基因类似序列(RGA)之间以及与烟草的N基因、亚麻的L6基因和拟南芥的RPS2基因之间的同源性,并对这些RGA进行了PCR和Southern验证与分析。结果表明:15个黄瓜RGA中,核苷酸序列同源性最高的是CsRGA2、CsR-GA4和CsRGA5,其次是CsRGA6、CsRGA7、CsRGA8和CsRGA9,CsRGA1和CsRGA3也存在较高的同源性;其余的RGA同源性较低。在氨基酸序列上也表现了相同的特征。与N、L6和RPS2等抗病基因的产物之间同源性最高46%,最低22%。根据核苷酸序列设计了15对特异引物,用PCR方法验证了所有黄瓜RGA的存在,其中CsRGA3在黄瓜品种间表现出多态性。利用特异引物PCR方法合成了15个黄瓜RGA的地高辛探针,与EcoRⅤ酶解的黄瓜‘215’、‘129’和‘L18’的基因组DNA进行Southern杂交,证实了各个RGA在基因组上的存在,同时发现,CsRGA9、CsRGA11~CsRGA15都是多拷贝,CsRGA3是单拷贝,其余为双拷贝。 展开更多
关键词 黄瓜 抗病基因类似序列 同源性 Southem杂交
下载PDF
葡萄无核基因的SCAR标记及Southern blot分析 被引量:7
12
作者 杨英军 王跃进 +2 位作者 周鹏 王西平 张剑侠 《西北农林科技大学学报(自然科学版)》 CSCD 北大核心 2002年第6期77-80,共4页
 根据无核基因特异RAPD标记的序列进行分析,合成1对特异引物P1+P3(序列分别是P1:5′CTCATCTTCTTGATGGTGAT3′;P3:5′AAGTGAAGAACATCATTAAGAAC3′),对30个葡萄材料进行PCR扩增,成功地将RAPD标记转换成SCAR标记。并对含有该标记序列的重...  根据无核基因特异RAPD标记的序列进行分析,合成1对特异引物P1+P3(序列分别是P1:5′CTCATCTTCTTGATGGTGAT3′;P3:5′AAGTGAAGAACATCATTAAGAAC3′),对30个葡萄材料进行PCR扩增,成功地将RAPD标记转换成SCAR标记。并对含有该标记序列的重组质粒进行Hind 和Spe 双酶切,获得的310bp片段回收后制成探测葡萄无核基因存在与否的杂交探针,成功地对7个葡萄品种进行Southernblot分析,实现了分子标记检测葡萄无核基因的目的。 展开更多
关键词 葡萄 无核基因 SCAR标记 southern-blot分析
下载PDF
一种简捷的Southern印迹杂交方法 被引量:8
13
作者 朱华晨 许新萍 李宝健 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第4期128-130,共3页
在综合前人方法的基础上,发展了一种简捷、灵敏、廉价、效果可靠的Southern印迹杂交方案。使用0 4mol LNaOH溶液将琼脂糖凝胶上的DNA在变性的同时转移到尼龙膜上,晾干膜后无需固定就可以直接用于杂交。预杂交液和杂交液选用Church缓冲系... 在综合前人方法的基础上,发展了一种简捷、灵敏、廉价、效果可靠的Southern印迹杂交方案。使用0 4mol LNaOH溶液将琼脂糖凝胶上的DNA在变性的同时转移到尼龙膜上,晾干膜后无需固定就可以直接用于杂交。预杂交液和杂交液选用Church缓冲系统,该缓冲系统中仅需10g LBSA作为封闭剂即可。整个洗膜过程可简化为一种溶液、2~3次洗涤。碱变性及转移后的尼龙膜,也可以用于地高辛(DIG)等非放射性检测系统,并可耐多轮杂交和洗脱。本方法可适用于包括高等植物基因组在内的多种生物材料的DNA检测。 展开更多
关键词 southern印迹 DNA 杂交 植物基因组
下载PDF
地高辛标记探针Southern印迹杂交技术要点及改进 被引量:7
14
作者 刘立鸿 许璐 +2 位作者 汪凯 张富春 马正海 《生物技术通报》 CAS CSCD 2008年第3期57-59,共3页
Southern印迹杂交技术是检测特定DNA片段的常规方法之一,其操作程序繁琐,对基因组DNA的提取、纯化、酶切等均有较高要求,要获得理想杂交结果需要反复摸索。总结地高辛标记探针Southern印迹杂交的技术要点,并结合具体操作提出改良方案。
关键词 地高辛 southern杂交 改进 技术要点
下载PDF
华山新麦草特异重复序列的筛选、克隆及Southern杂交分析 被引量:5
15
作者 陈林刚 武军 +5 位作者 赵继新 刘淑会 杨群慧 杜万里 庞玉辉 陈新宏 《麦类作物学报》 CAS CSCD 北大核心 2010年第1期23-28,共6页
为了寻找华山新麦草特异重复序列,以华山新麦草、栽培一粒小麦、栽培二粒小麦、野生一粒小麦、野生二粒小麦、圆锥小麦、阿拉拉特小麦、茹科夫斯基小麦、斯卑尔脱小麦、普通小麦"中国春"(CS)为材料,利用200条RAPD引物筛选出11条华... 为了寻找华山新麦草特异重复序列,以华山新麦草、栽培一粒小麦、栽培二粒小麦、野生一粒小麦、野生二粒小麦、圆锥小麦、阿拉拉特小麦、茹科夫斯基小麦、斯卑尔脱小麦、普通小麦"中国春"(CS)为材料,利用200条RAPD引物筛选出11条华山新麦草特异条带(命名为RHS1-RHS11),并对这些条带进行回收、克隆、测序。将序列在NCBI数据库中进行比对,其中RHS1、RHS2、RHS3、RHS4、RHS6、RHS8、RHS9在NCBI数据库中未发现与其同源的序列。RHS5、RHS7、RHS10、RHS11在NCBI数据库中有相似序列,其最高覆盖度和最高相似性分别为:83%和100%、99%和85%、49%和100%、19%和83%。通过Southern blotting进行序列特异性检测,RHS1、RHS2、RHS4、RHS6和RHS9等5个克隆在10种材料中都没有杂交信号;RHS7、RHS10和RHS11在华山新麦草及其他9种材料中都有弥散分布的杂交信号;RHS3、RHS5和RHS8只在华山新麦草中有杂交信号的序列。这些结果说明RHS3、RHS5、RHS8为华山新麦草基因组特异重复序列。 展开更多
关键词 华山新麦草 特异重复序列 克隆 southern杂交
下载PDF
基于DIG-化学发光法的Southern blot方法优化 被引量:4
16
作者 张晓 张锐 +5 位作者 于源华 史计 孟志刚 孙国清 周焘 郭三堆 《生物技术通报》 CAS CSCD 北大核心 2011年第9期205-210,共6页
目前,基于DIG-化学发光法的Southern blot技术已在生物实验室广泛应用,但在试验过程中经常会遇到背景黑、目的信号弱等问题,以致不能获得理想结果。在棉花线粒体基因组RFLP分析过程中结合前人经验对基于DIG-化学发光法的Southern blot... 目前,基于DIG-化学发光法的Southern blot技术已在生物实验室广泛应用,但在试验过程中经常会遇到背景黑、目的信号弱等问题,以致不能获得理想结果。在棉花线粒体基因组RFLP分析过程中结合前人经验对基于DIG-化学发光法的Southern blot技术在探针标记、探针浓度、探针剥离等方面进行了优化。优化后的方法重复性好,一张转好的尼龙膜最多可以反复使用11次;一份杂交液在两年内至少可以反复使用5次且不会明显降低杂交效果。 展开更多
关键词 southern BLOT DIG标记 化学发光法 尼龙膜 探针
下载PDF
转基因甘蔗植株Southern杂交体系的优化 被引量:7
17
作者 崔学强 张树珍 +1 位作者 沈林波 冯翠莲 《生物技术通报》 CAS CSCD 北大核心 2015年第12期105-109,共5页
对甘蔗Southern杂交体系的优化,旨为转基因甘蔗Southern杂交鉴定分析提供参考。以转基因甘蔗为材料,就探针不同标记方法的比较、甘蔗基因组DNA的提取、基因组DNA酶切量、酶切时间及杂交过程等方面,对地高辛标记的Southern杂交技术进行... 对甘蔗Southern杂交体系的优化,旨为转基因甘蔗Southern杂交鉴定分析提供参考。以转基因甘蔗为材料,就探针不同标记方法的比较、甘蔗基因组DNA的提取、基因组DNA酶切量、酶切时间及杂交过程等方面,对地高辛标记的Southern杂交技术进行了优化研究。结果表明,改良的CTAB法提取的甘蔗DNA能满足后期实验的要求;PCR法标记探针的效率较随机引物法标记探针的效率高,更适合用于Southern杂交;40μg的DNA在400μL酶切体系中,酶切10 h可获得良好的酶切效果;杂交温度40℃,杂交18 h,可获得清晰的杂交条带。 展开更多
关键词 甘蔗 southern杂交 地高辛 PCR法标记探针 酶切
下载PDF
向下转膜法在乙肝病毒Southern杂交中的应用 被引量:3
18
作者 张秉强 吴莹 +4 位作者 唐霓 郭进军 黄英 汤华 黄爱龙 《生物技术通报》 CAS CSCD 2005年第2期26-28,共3页
目的评价向下转膜法在乙肝病毒(HBV)Southern杂交中的应用效果。方法用带有1.3倍HBV基因的真核表达载体转染HepG2细胞,使其产生瞬时HBV表达,72小时收集细胞并提取细胞总DNA,琼脂糖凝胶电泳后,以向上和向下两种方式转移在尼龙膜上;用化... 目的评价向下转膜法在乙肝病毒(HBV)Southern杂交中的应用效果。方法用带有1.3倍HBV基因的真核表达载体转染HepG2细胞,使其产生瞬时HBV表达,72小时收集细胞并提取细胞总DNA,琼脂糖凝胶电泳后,以向上和向下两种方式转移在尼龙膜上;用化学发光标记和检测试剂盒将乙肝病毒基因片段标记成探针,再与向上和向下转膜后的尼龙膜进行杂交,判断产生明显HBV杂交条带所需的细胞总DNA量,从而验证向下转膜法在乙肝病毒Southern杂交中的应用效果。结果发现向下转膜后,检测HBV表达所需的细胞总DNA量极少,灵敏度高,0.5μg细胞总DNA电泳后转膜,即可检测出HBVDNA的表达,凝胶中仅有8%的DNA残留;而向上转膜所需的总DNA量大,灵敏度低,25μg的细胞总DNA电泳后转膜,仅能检测出弱的条带。结论向下转膜法是一种较好的转膜方式,适于对乙肝病毒的Southern杂交,值得推广应用。 展开更多
关键词 southern杂交 乙肝病毒 膜法 HepG2细胞 琼脂糖凝胶电泳 真核表达载体 总DNA 化学发光标记 DNA量 HBV 检测试剂盒 基因片段 推广应用 尼龙膜 灵敏度 条带 转染 探针
下载PDF
东北红豆杉紫杉二烯合成酶cDNA克隆及其与紫杉醇产生菌基因组DNA的Southern杂交(英文) 被引量:4
19
作者 赵凯 王歆 +4 位作者 李秀凉 张新建 肖珊 平文祥 周东坡 《黑龙江大学自然科学学报》 CAS 北大核心 2010年第6期747-753,共7页
为进一步研究紫杉二烯合成酶的作用机理和紫杉醇生物合成代谢调控机制,采用RT-PCR技术从东北红豆杉(Taxus cuspidata)树叶中获得了紫杉二烯合成酶基因片段,将该片段克隆在载体pGEMT-easy vector上,并转化到E.coliJM109中,经EcoRI酶切鉴... 为进一步研究紫杉二烯合成酶的作用机理和紫杉醇生物合成代谢调控机制,采用RT-PCR技术从东北红豆杉(Taxus cuspidata)树叶中获得了紫杉二烯合成酶基因片段,将该片段克隆在载体pGEMT-easy vector上,并转化到E.coliJM109中,经EcoRI酶切鉴定后,对阳性克隆进行序列测定,获得紫杉二烯合成酶基因片段长度为909 bp,编码303个氨基酸,与GenBank中收录的紫杉二烯合成酶的同源性达到98%;对获得的紫杉二烯合成酶基因和紫杉醇产生菌HQD33基因组DNA进行了Southern杂交。结果初步证实了紫杉二烯合成酶存在于通过内生真菌发酵生产紫杉醇的生物合成途径中。为利用分子生物学手段研究通过内生真菌发酵生产紫杉醇生物合成的代谢调控和构建高产紫杉醇基因工程菌株提供了强有力的理论指导。 展开更多
关键词 东北红豆杉 内生真菌 紫杉醇 紫杉二烯合成酶 southern杂交
下载PDF
甜菜基因组DNA的提取及Southern杂交分析 被引量:4
20
作者 侯静 马凤鸣 +2 位作者 陈胜勇 丁广洲 李彩凤 《东北农业大学学报》 CAS CSCD 2008年第12期14-18,共5页
分别采用常规CTAB法和SDS法提取甜菜基因组DNA,并将提取的DNA应用于Southern杂交分析,发现基因组DNA的质量对杂交信号有非常大的影响。常规CTAB法提取的DNA产生的Southern杂交信号,仅出现在高分子质量位置;SDS法提取的DNA产生的Souther... 分别采用常规CTAB法和SDS法提取甜菜基因组DNA,并将提取的DNA应用于Southern杂交分析,发现基因组DNA的质量对杂交信号有非常大的影响。常规CTAB法提取的DNA产生的Southern杂交信号,仅出现在高分子质量位置;SDS法提取的DNA产生的Southern杂交信号,在高分子质量和低分子质量位置均出现。SDS法提取的甜菜基因组DNA适于Southern杂交分析。 展开更多
关键词 甜菜 基因组DNA 常规CTAB法 SDS法 southern杂交
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部