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   376篇
  免费   125篇
各国政治   4篇
工人农民   3篇
世界政治   3篇
外交国际关系   147篇
法律   161篇
中国共产党   7篇
中国政治   10篇
政治理论   9篇
综合类   157篇
  2024年   3篇
  2023年   10篇
  2022年   12篇
  2021年   14篇
  2020年   27篇
  2019年   18篇
  2018年   13篇
  2017年   8篇
  2016年   21篇
  2015年   20篇
  2014年   27篇
  2013年   34篇
  2012年   31篇
  2011年   26篇
  2010年   25篇
  2009年   27篇
  2008年   12篇
  2007年   21篇
  2006年   28篇
  2005年   28篇
  2004年   29篇
  2003年   15篇
  2002年   8篇
  2001年   6篇
  2000年   6篇
  1999年   8篇
  1998年   4篇
  1997年   4篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1991年   1篇
  1989年   3篇
  1988年   1篇
  1983年   1篇
排序方式: 共有501条查询结果,搜索用时 187 毫秒
121.
对国内3株马立克氏病病毒血清1型(Marek’s disease virus type 1,MDV-1)流行毒株的基因组重复区进行序列测定及分析,并与GenBank中登录的MDV-1参考毒株序列进行比较。结果显示,3株毒株的基因组重复区序列具有较高同源性,在进化上属于一独立分支。3株毒株的长重复区长度约为12kb,预测的开放阅读框(ORF)分别为43、40、43个;短重复区约为12kb,预测的ORF分别为27、25、26个。3株毒株的多个ORF中存在它们特有的共性氨基酸突变,是国内MDV-1流行毒株的特有的遗传性特征。该研究为我国MDV的流行、遗传变异及防控研究提供了材料。  相似文献   
122.
为构建能为新城疫病毒拯救提供直接使用的全长cDNA克隆,利用分子克隆的方法,将新城疫病毒La Sota株全基因组分成末端部分重叠的11个片段(F1~F11),按其基因组顺序克隆至改造后的真核表达载体pVAXr上,同时在全长cDNA两侧引入T7启动子和丁型肝炎病毒核酶(Rib)序列,以确保病毒基因组转录产物的两端形成精确的核酸序列。鉴定结果表明,新城疫病毒La Sota株基因组全长cDNA已成功克隆至pVAXr上,命名为pVAXr-FL。本研究为新城疫病毒的拯救及外源基因的表达奠定了基础。  相似文献   
123.
Benign prostatic hyperplasia with chronic bladder outlet obstruction has been associated with deep venous thrombosis (DVT) and fatal pulmonary thromboembolism (PTE). To evaluate this further, 60 autopsy cases of men with PTE were compared with 60 age-matched controls. The criteria for outlet obstruction were macroscopic prostatic enlargement with bladder trabeculation and benign prostatic hyperplasia on microscopy. Ten of the 60 men (16.7%) with fatal PTE had evidence of bladder outlet obstruction (age 57-78 years; mean 71.4 years). Of the 60 controls, 12 had evidence of bladder outlet obstruction (20%) (age 67-86 years; mean 75.5 years). No significant relationship could be demonstrated between bladder outlet obstruction and fatal PTE cases (p = 0.8). Given reports of this association, however, it is possible that bladder distension with venous compression may act as a risk modifier in certain individuals in association with other significant comorbidities, but this risk appears low.  相似文献   
124.
Abstract: Histopathologic features of New Mexico 2009 H1N1 fatalities have not been representative of those reported nationwide. We retrospectively reviewed medical records of all New Mexico 2009 pandemic influenza A (pH1N1) fatalities (n = 50). In cases in which autopsy was performed (n = 12), histologic sections and culture results were examined. In contrast to previously published studies, the majority of our fatalities did not have diffuse alveolar damage (DAD) (2/12; 16.7%). Common findings included pulmonary interstitial inflammation and edema, tracheobronchitis, and pneumonia. Two cases had significant extra‐pulmonary manifestations: myocarditis and cerebral edema with herniation. The majority had a rapid disease course: range from 1 to 12 days (median, 2 days), and Native Americans were disproportionately represented among fatalities. These findings suggest that New Mexico H1N1 fatalities generally did not survive long enough to develop the classic picture of DAD. Pathologists should be aware that H1N1 may cause extra‐pulmonary pathology and perform postmortem cultures and histologic sampling accordingly.  相似文献   
125.
We investigated the feasibility of postmortem percutaneous needle biopsy (PNB) for obtaining pulmonary samples adequate for the study of pulmonary fat embolism (PFE). Samples of both lungs were obtained from 26 cadavers via two different methods: (i) PNB and (ii) the double-edged knife technique, the gold standard at our institute. After water storage and Sudan III staining, six forensic pathologists independently examined all samples for the presence and severity of PFE. The results were compared and analyzed in each case regarding the vitality of the PFE and its relationship to the cause of death. The results showed that PFE was almost identically diagnosed and graded on the samples obtained via both methods. The discrepancies between the two techniques did not affect the diagnoses of vitality or cause of death related to PFE. This study demonstrates the feasibility of the PNB sampling method for the diagnosis and interpretation of PFE in the postmortem setting.  相似文献   
126.
To investigate the association of five SNPs(rs823083,rs708723,rs4951261,rs823076 and rs16856110) at the PARK16 locus with Parkinson's disease(PD),and to potentiate its forensic application.The genomic DNAs of 215 PD patients and 212 matched controls from the northern Han Chinese population were amplified in two independent PCR systems and subsequently genotyped by digestion with the three endonucleases(Hinf Ⅰ,Nco Ⅰ and Msp Ⅰ).The genetic parameters and association studies were carried out with SPSS 13.0,Haploview version 4.2 and PLINK 1.07 softwares.We detected accurately all genotypes in the five SNPs with multiplex PCR-RFLP and mismatched multiplex PCR-RFLP techniques.The genotypes of four SNPs,except for rs823083,were in Hardy-Weinberg equilibrium.The four SNPs,rs16856110,rs4951261,rs708723 and rs823076,which were in linkage equilibrium,should not be associated with PD(P-values ranging from 0.077 to 0.544).The SNPs investigated at the PARK16 locus were not found to be involved in PD-associated blocks in the northern Han Chinese population.The allele distributions of rs708723,rs4951261,rs823076 and rs16856110 in the northern Han Chinese population can be highly polymorphic,which can be applied to genetic analysis and forensic practices.  相似文献   
127.
氢氧化铝纳米颗粒对鸡新城疫抗原的免疫佐剂效应   总被引:2,自引:0,他引:2  
以新城疫病毒为抗原,制备纳米氢氧化铝和常规氢氧化铝佐剂灭活疫苗,分别免疫20日龄雏鸡,比较了免疫后2~24 d的抗体效价和外周血淋巴细胞CD4、CD8分子mRNA的表达水平。结果显示,纳米氢氧化铝佐剂组抗体效价在免疫后第10 d达到峰值,为6.67±0.58,免疫保护期超过9 d,常规氢氧化铝佐剂组抗体效价在免疫后第10 d达到峰值,为4.33±0.58,免疫保护期小于7 d;与常规氢氧化铝佐剂组相比,纳米氢氧化铝佐剂组免疫后4~17 d的CD4以及10~17 d的CD8分子mRNA的表达水平显著提高,在峰值时后者的表达量为前者的2.0和1.9倍。结果表明,纳米氢氧化铝佐剂能辅佐鸡体产生比常规氢氧化铝佐剂更强烈的体液免疫和细胞免疫。  相似文献   
128.
The role of emotion in the relationship between traumatic experiences and physical pain was examined via path modeling by using a sample of hospital outpatients (N = 138). Most of the participants reported being traumatized (77%) and experiencing chronic pain (69%). Trauma survivors and nontraumatized individuals did not differ significantly on mean symptom scale scores (i.e., depression, anxiety, anger, dissociation, somatization and pain). However, a moderate effect size was found for dissociation. There were also significant associations found between trauma levels and levels of adult symptomatology. Interestingly, sexual abuse was less highly correlated with symptomatology than other types of traumatization, such as neglect. None of the three proposed path models describing the relationship between trauma, pain, and emotion fit the data successfully. Implications are discussed.  相似文献   
129.
用人工接种方法观察了鸡大肝和大脾(BLS)病鸡免疫器官的大体和组织病理学的动态变化。大体变化除脾肿胀外,盲肠扁桃体、胸腺和腔上囊也发生肿胀、出血。组织病理学的主要特点是脾、盲肠扁桃体、胸腺、腔上囊和哈德尔氏腺除发生变性和坏死外,早期浆细胞和淋巴细胞增生,中、后期则出现巨噬细胞、淋巴细胞和网状细胞等。结果表明,BLS病的早期以体液免疫为主,后期的细胞免疫和体液免疫均增强,这两种免疫在此病的发生和发展过程中均起重要作用。  相似文献   
130.
肺动脉栓塞猝死的法医病理学检验   总被引:7,自引:0,他引:7  
Wei DM  Yan HQ  Wang ZS  He YH 《法医学杂志》1999,15(2):73-74,76
对50例肺动脉栓塞猝死案例分析,结果显示:引起肺动脉栓塞猝死的主要原因为创伤(42%),心脏疾病(32%),外科手术(20%)等。血栓栓子多来源于下肢静脉(80%);其次为心腔内附壁血栓(20%)。发生猝死高峰季节为10~12月;低峰季节为4~6月。猝死场所多见于医院内。最后提出了该病的法医学鉴定注意事项  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