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61.
62.
In this paper we present the detailed clinical and cytogenetic analysis of a prenatally detected complex Congenital Diaphragmatic Hernia (CDH) patient with a mosaic unbalanced translocation (5;12). High-resolution whole genome SNP array confirmed a low-level mosaicism (20%) in uncultured cells, underlining the value of array technology for identification studies. Subsequently, targeted Fluorescence In-Situ Hybridization in postmortem collected tissues demonstrated a similar low-level mosaicism, independently of the affected status of the tissue. Thus, a higher incidence of the genetic aberration in affected organs as lung and diaphragm cannot explain the severe phenotype of this complex CDH patient. Comparison with other described chromosome 5p and 12p anomalies indicated that half of the features presented in our patient (including the diaphragm defect) could be attributed to both chromosomal areas. In contrast, a few features such as the palpebral downslant, the broad nasal bridge, the micrognathia, microcephaly, abnormal dermatoglyphics and IUGR better fitted the 5p associated syndromes only. This study underlines the fact that low-level mosaicism can be associated with severe birth defects including CDH. The contribution of mosaicism to human diseases and specifically to congenital anomalies and spontaneous abortions becomes more and more accepted, although its phenotypic consequences are poorly described phenomena leading to counseling issues. Therefore, thorough follow-up of mosaic aberrations such as presented here is indicated in order to provide genetic counselors a more evidence based prediction of fetal prognosis in the future.  相似文献   
63.
Obesity-related cardiac lipid accumulation is associated with increased myocardial oxidative stress. The role of the antioxidant glutathione in cardiac lipotoxicity is unclear. Cystathionine β-synthase (Cbs) catalyzes the first step in the trans-sulfuration of homocysteine to cysteine, which is estimated to provide ~50% of cysteine for hepatic glutathione biosynthesis. As cardiac glutathione is a reflection of the liver glutathione pool, we hypothesize that mice heterozygous for targeted disruption of Cbs (Cbs(+/-)) are more susceptible to obesity-related cardiolipotoxicity because of impaired liver glutathione synthesis. Cbs(+/+) and Cbs(+/-) mice were fed a high fat diet (60% energy) from weaning for 13 weeks to induce obesity and had similar increases in body weight and body fat. This was accompanied by increased hepatic triglyceride but no differences in hepatic glutathione levels compared with mice fed chow. However, Cbs(+/-) mice with diet-induced obesity had greater glucose intolerance and lower total and reduced glutathione levels in the heart, accompanied by lower plasma cysteine levels compared with Cbs(+/+) mice. Higher triglyceride concentrations, increased oxidative stress, and increased markers of apoptosis were also observed in heart from Cbs(+/-) mice with diet-induced obesity compared with Cbs(+/+) mice. This study suggests a novel role for Cbs in maintaining the cardiac glutathione pool and protecting against cardiac lipid accumulation and oxidative stress during diet-induced obesity in mice.  相似文献   
64.
Seawater reverse osmosis (SWRO) membrane biofouling remains a common challenge in the desalination industry, but the marine bacterial community that causes membrane fouling is poorly understood. Microbial communities at different stages of treatment processes (intake, cartridge filtration, and SWRO) of a desalination pilot plant were examined by both culture-based and culture-independent approaches. Bacterial isolates were identified to match the genera Shewanella, Alteromonas, Vibrio, and Cellulophaga based on 16S rRNA gene sequencing analysis. The 16S rRNA gene clone library of the SWRO membrane biofilm showed that a filamentous bacterium, Leucothrix mucor, which belongs to the gammaproteobacteria, accounted for nearly 30% of the clone library, while the rest of the microorganisms (61.2% of the total clones) were related to the alphaproteobacteria. 16S rRNA gene terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that bacteria colonizing the SWRO membrane represented a subportion of microbes in the source seawater; however, they were quite different from those colonizing the cartridge filter. The examination of five SWRO membranes from desalination plants located in different parts of the world showed that although the bacterial communities from the membranes were not identical to each other, some dominant bacteria were commonly observed. In contrast, bacterial communities in source seawater were significantly different based on location and season. Microbial profiles from 14 cartridge filters collected from different plants also revealed spatial trends.  相似文献   
65.
珊瑚礁生态脆弱性评价——以泰国思仓岛为例   总被引:1,自引:0,他引:1  
珊瑚礁生态系统受到环境变化、人类活动等各种因素的严重威胁,保护珊瑚礁生态系统是目前全球海洋生态保护的热点,对珊瑚礁开展定量的生态脆弱性评估能够为保护管理对策的制定提供重要科学依据。本研究选取泰国思仓岛作为研究区域,结合空间分析技术建立了具有通用性的珊瑚礁生态脆弱性评估方法。基于ESA模型构建了珊瑚礁生态脆弱性综合指数和评价指标体系,系统分析了思仓岛珊瑚礁脆弱性的来源、构成,并直观展现了脆弱性的区域空间分布。结果表明:思仓岛研究区东北侧的珊瑚礁生态脆弱性大于西南侧,当地珊瑚礁的关键影响因子分别为驳船排污、港口码头、水体透明度等。根据脆弱性评价的结果,提出了当地珊瑚礁保护与修复的空间分区管理对策。本研究为印度-太平洋区系珊瑚礁生态脆弱性评价提供了可行的示例,也为中国的珊瑚礁可持续管理研究提供了借鉴和参照。  相似文献   
66.
应用性外激素监测马尾松毛虫发生数量的初步研究   总被引:8,自引:0,他引:8  
本研究采用持效期达 3 0天以上的复合橡胶载体的新型诱芯诱捕器对马尾松毛虫进行林间监测 ,发现诱蛾数量与田间调查的幼虫数量有很大的关联性 ,各乡镇每诱捕点平均诱蛾数与 1代、2代幼虫虫株率、平均虫口的变化趋势基本相同  相似文献   
67.
ABSTRACT: BACKGROUND: Variations in cytokine and immune mediator expression patterns in amniotic fluid due to gestational age, maternal age and fetal gender were investigated. METHODS: Amniotic fluid samples were obtained from 192 women, 82 with a mid-trimester amniocentesis (median gestational age 17 weeks) and 110 with a caesarean section not in labor (median gestational age 39 weeks). Amniotic fluid was screened by commercial ELISAs for the TH1/TH2/TH17 cytokines and immune mediators IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-15, IL-17, TNF alpha, GROalpha, MIP1alpha, MIP1beta, histone, and IP10. Analysis was by Bonferroni correction for multiple comparisons. RESULTS: None of the 15 examined cytokines revealed any differences in expression patterns regarding fetal gender and age of the mothers. Significant differences were found in IL-4, IL-10, IL-12 TNF- alpha and MIP1-beta with respect to gestational age. CONCLUSIONS: Cytokines utilized as biomarkers in the diagnosis of intrauterine infections are not influenced in their expression pattern by fetal gender or maternal age, but may vary with respect to gestational age.  相似文献   
68.
[目的]根结线虫危害严重,难防难控,前期研究发现一株深海来源的独岛枝芽胞杆菌(Virgibacillus dokdonensis)MCCC 1A00493对南方根结线虫具有良好的体外拮抗效果,本研究分离鉴定菌株发酵液中杀线虫活性物质,对其作用线虫的多种模式进行研究,为菌株有效控制植物病原线虫的应用奠定理论基础.[方法]...  相似文献   
69.
Gene manipulation tools for an arachidonic-producing filamentous fungus, Mortierella alpina 1S-4, have not been sufficiently developed. In this study, Agrobacterium tumefaciens-mediated transformation (ATMT) was investigated for M. alpina 1S-4 transformation, using the uracil-auxotrophic mutant (ura5 strain) of M. alpina 1S-4 as a host strain and the homologous ura5 gene as a selectable marker gene. Furthermore, the gene for ω3-desaturase, catalyzing the conversion of n-6 fatty acid to n-3 fatty acid, was overexpressed in M. alpina 1S-4 by employing the ATMT system. As a result, we revealed that the frequency of transformation surpassed 400 transformants/108 spores, most of the integrated T-DNA appeared as a single copy at a random position in chromosomal DNA, and most of the transformants (60 to 80%) showed mitotic stability. Moreover, the accumulation of n-3 fatty acid in transformants was observed under the conditions of optimal ω3-desaturase gene expression. In particular, eicosapentaenoic acid (20:5n-3), an end product of n-3 fatty acids synthesized in M. alpina 1S-4, reached a maximum of 40% of total fatty acids. In conclusion, the ATMT system was found to be effective and suitable for the industrial strain Mortierella alpina 1S-4 and will be a useful tool for basic mutagenesis research and for industrial breeding of this strain.Two decades ago, a filamentous zygomycete fungus, Mortierella alpina 1S-4, was isolated from soil as a potent producer of polyunsaturated fatty acids (PUFAs) in our laboratory and was utilized for commercial production of arachidonic acid (AA) (20:4n-6) (21). Breeding of mutants derived from the wild strain led to the production of dihomo-γ-linolenic acid (20:3n-6) and Mead acid (20:3n-9) (10-12) (Fig. (Fig.1).1). Furthermore, we attempted to produce other PUFAs synthesized in M. alpina 1S-4, since some fatty acids (e.g., 18:2n-9, 18:4n-3, and 20:4n-3) have limited natural sources and could have promising beneficial physiological effects (9). In particular, for microbial production of n-3 PUFAs, currently prepared from fish oil, it is necessary to achieve stable productivity and quality; however, mutation treatment caused low activity of the specific enzymes involved in PUFA biosynthesis, which is unsuitable for industrial application. In addition, gene manipulation tools have not been sufficiently developed for metabolic control of the PUFA synthetic pathway. Genetic manipulation is a new means of molecularly breeding industrial strains, analyzing their physiological properties, and clarifying the biosynthetic pathway to PUFAs. A comprehensive transformation system for this fungus has been fundamentally established. It involves a uracil-auxotrophic mutant (ura5 strain) as a host strain, a homologous ura5 gene as a selectable marker gene, and transformation through the biolistic method, which is the only effective method (24).Open in a separate windowFIG. 1.Putative biosynthetic pathway of PUFAs in Mortierella alpina 1S-4. OA, oleic acid; LA, linoleic acid; ALA, α-linolenic acid; GLA, γ-linolenic acid; SDA, stearidonic acid; EDA, n-9 eicosadienoic acid; DGLA, dihomo-γ-linolenic acid; ETA, n-3 eicosatetraenoic acid; MA, Mead acid. Open and black arrows indicate elongase and desaturase reactions, respectively.Agrobacterium tumefaciens-mediated transformation (ATMT) has been employed for a wide range of plants (7, 27). Recently, it was reported that A. tumefaciens is also able to transfer its DNA to various fungi, including ascomycetes, basidiomycetes, zygomycetes, and oomycetes, as well as to plants (2, 5, 16). Additionally, this bacterium can transform intact cells and spores as well as protoplasts. Under mild conditions, the ATMT system generates a large number of stable transformants, which show vigorous growth, indicating that the ATMT system can be an efficient tool for molecular manipulation of M. alpina 1S-4. Moreover, the frequency of homologous recombination was higher than that with conventional transformation methods (8). In this study, we evaluated the external gene transfer system using the ATMT system and determined the optimal conditions for M. alpina 1S-4. Furthermore, we overexpressed the ω3-desaturase gene to improve n-3 PUFA productivity in an industrial n-6-PUFA-producing strain, M. alpina 1S-4 (18, 20), using ATMT.  相似文献   
70.
能源植物杂交狼尾草对NaCl胁迫的响应及其耐盐阈值   总被引:6,自引:0,他引:6       下载免费PDF全文
以能源植物杂交狼尾草(Pennisetum americanum × P. purpureum)为实验材料, 用沙培盆栽的方法, 分别用0、0.3%、0.5%、0.9%和1.2%的NaCl处理4周后, 测定植株鲜重、干重、含水量、株高、分蘖数和不同部位的离子含量, 以确定其耐盐阈值和耐盐方式。结果表明, 随着NaCl浓度的增加, 杂交狼尾草的鲜重、干重、株高和分蘖数都显著降低, 地上部分鲜重和干重分别在NaCl浓度为0.568%和0.570%时下降了50%, 1.2% NaCl处理的杂交狼尾草几乎全部死掉。表明杂交狼尾草的耐盐阈值为0.57%; 但植株含水量和功能叶的Na+含量变化不明显, 老叶Na+含量在NaCl浓度为0.9%时明显升高, 是对照的2倍; 随NaCl浓度的升高, 根中的Na+含量显著升高, 在NaCl浓度为0.9%时, 根中的Na+含量达到对照的3倍以上。Na+含量在功能叶, 老叶和根中含量依次升高; 随NaCl浓度的升高, 地上部分和根中的K+含量都无明显变化; 随NaCl浓度的升高, 根中的Na+/K+明显增加, 而地上部分Na+/K+只有当NaCl浓度为0.9%时明显增加。以上结果表明杂交狼尾草具有一定的耐盐性, 其耐盐方式为拒盐, 耐盐阈值为0.57% (约100 mmol·L-1)。  相似文献   
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