首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   128篇
  免费   4篇
  2023年   2篇
  2022年   4篇
  2021年   9篇
  2020年   4篇
  2019年   3篇
  2018年   7篇
  2017年   3篇
  2016年   1篇
  2015年   5篇
  2014年   3篇
  2013年   7篇
  2012年   9篇
  2011年   5篇
  2010年   3篇
  2009年   5篇
  2008年   9篇
  2007年   9篇
  2006年   8篇
  2005年   5篇
  2004年   3篇
  2003年   4篇
  2001年   1篇
  1999年   1篇
  1992年   1篇
  1990年   2篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1978年   4篇
  1975年   1篇
  1974年   2篇
  1971年   1篇
  1966年   1篇
  1963年   1篇
  1958年   1篇
排序方式: 共有132条查询结果,搜索用时 31 毫秒
1.
2.
Plasmonics - Polarization reconfigurable dielectric resonator antenna (DRA) backed by plasma artificial magnetic conductor (AMC) ground plane is designed and optimized for 10-GHz applications. The...  相似文献   
3.
Experimental and Applied Acarology - This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl...  相似文献   
4.
Molecular Biology Reports - Hepatocellular carcinoma (HCC) is the most common primary liver cancer characterized by dysregulation of several crucial cellular signaling pathways such as...  相似文献   
5.
Plasmonics - This paper introduces on-chip patch antenna with electronic beam switching using graphene strip array for wireless communications at 415 GHz. The on-chip patch antenna is...  相似文献   
6.
Next-generation sequencing of cell-free circulating solid tumor DNA addresses two challenges in contemporary cancer care. First this method of massively parallel and deep sequencing enables assessment of a comprehensive panel of genomic targets from a single sample, and second, it obviates the need for repeat invasive tissue biopsies. Digital SequencingTM is a novel method for high-quality sequencing of circulating tumor DNA simultaneously across a comprehensive panel of over 50 cancer-related genes with a simple blood test. Here we report the analytic and clinical validation of the gene panel. Analytic sensitivity down to 0.1% mutant allele fraction is demonstrated via serial dilution studies of known samples. Near-perfect analytic specificity (> 99.9999%) enables complete coverage of many genes without the false positives typically seen with traditional sequencing assays at mutant allele frequencies or fractions below 5%. We compared digital sequencing of plasma-derived cell-free DNA to tissue-based sequencing on 165 consecutive matched samples from five outside centers in patients with stage III-IV solid tumor cancers. Clinical sensitivity of plasma-derived NGS was 85.0%, comparable to 80.7% sensitivity for tissue. The assay success rate on 1,000 consecutive samples in clinical practice was 99.8%. Digital sequencing of plasma-derived DNA is indicated in advanced cancer patients to prevent repeated invasive biopsies when the initial biopsy is inadequate, unobtainable for genomic testing, or uninformative, or when the patient’s cancer has progressed despite treatment. Its clinical utility is derived from reduction in the costs, complications and delays associated with invasive tissue biopsies for genomic testing.  相似文献   
7.
Spore suspensions of Aspergillus oryzae NRRL 3484 were subjected to mutagenesis using ultraviolet-irradiation followed by chemical treatments to improve the biosynthesis of cellulase. Ten mutant strains namely UEAC7, UEAR5, UNAC4, UNAC16, UNAR19, UNBC7, UNBR3, UNBR10, UNBR23 and UNBR25 were selected and their extracellular cellulase activities were assayed. Mutant UNAC4 gave the highest cellulase production [2,455 ± 28 U/g-dry substrate (ds) for filter paper-ase (FP-ase)] in a yield 4-fold exceeding that of the wild type strain (578 ± 5.0 U/g-ds for FP-ase). Rice straw (RS) was used as a sole carbon source for the enzyme production at a concentration of 10 % (w/v). Maximum cellulase production was achieved at initial medium pH 5.5, initial moisture content 77 % and an incubation temperature 28 °C on the fifth day of growth. NH4Cl proved to be the suitable added nitrogen source for maximum enzyme production followed by peptone. These results clearly indicate the cost-effectiveness of solid state fermentation technology in the economic production of extracellular cellulase. The hyper-production of cellulase by mutant strain UNAC4 has potential for industrial processes that convert lignocellulosic material (e.g. RS) into products of commercial value such as glucose and biofuels.  相似文献   
8.
Haemopathological changes attributed to heavy metal poisoning were observed in blood smears of Liza macrolepis (Smith) taken after exposures of 96 h to graded doses (mg/l) of copper (0.11–1.80), lead (1.15–18.36), and mercury (0.04–0.59), in a flow-through marin bioassay system. In general, changes in leucocytic profile appear to be correlated with pathological changes caused by increasing copper and mercury concentrations. By contrast, blood samples of mullets exposed to lead, showed significant polychromasia and + anisocytosis regardless of concentrations. The RBC count, haemoglobin content, and haemotocrit percentages were less valuable in diagnosis of copper and mercury effects.These manifestations of poisoning by trace elements bear a resemblance to the pathological changes that have been shown clinically and experimentally in mammals. Consequently, blood measurements on marine organisms may be diagnostic of undeirably high levels of copper and mercury, and so may constitute useful indicators of marine pollution.  相似文献   
9.
10.

Introduction  

Advanced glycation end products (AGEs) are produced and can accumulate during chronic inflammation, as might be present in patients with rheumatoid arthritis (RA). AGEs are involved in the development of cardiovascular disease. The aim of this study is to evaluate whether AGEs are increased in patients with long-standing RA and whether AGE accumulation is related to disease activity, disease severity and measures of (premature) atherosclerosis, such as endothelial activation, endothelial dysfunction and intima media thickness (IMT).  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号