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   1099篇
  免费   89篇
各国政治   112篇
工人农民   72篇
世界政治   134篇
外交国际关系   63篇
法律   619篇
中国政治   4篇
政治理论   184篇
  2023年   19篇
  2022年   8篇
  2021年   26篇
  2020年   37篇
  2019年   43篇
  2018年   75篇
  2017年   96篇
  2016年   67篇
  2015年   56篇
  2014年   62篇
  2013年   178篇
  2012年   54篇
  2011年   42篇
  2010年   20篇
  2009年   20篇
  2008年   45篇
  2007年   41篇
  2006年   41篇
  2005年   40篇
  2004年   43篇
  2003年   47篇
  2002年   34篇
  2001年   20篇
  2000年   16篇
  1999年   10篇
  1998年   6篇
  1997年   5篇
  1996年   2篇
  1995年   3篇
  1994年   3篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1984年   2篇
  1983年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1972年   2篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
  1964年   1篇
排序方式: 共有1188条查询结果,搜索用时 531 毫秒
841.
The reference database of highly informative Y-chromosomal short tandem repeat (STR) haplotypes (YHRD), available online at http://ystr.charite.de, represents the largest collection of male-specific genetic profiles currently available for European populations. By September 2000, YHRD contained 4688 9-locus (so-called "minimal") haplotypes, 40% of which have been extended further to include two additional loci. Establishment of YHRD has been facilitated by the joint efforts of 31 forensic and anthropological institutions. All contributing laboratories have agreed to standardize their Y-STR haplotyping protocols and to participate in a quality assurance exercise prior to the inclusion of any data. In view of its collaborative character, and in order to put YHRD to its intended use, viz. the support of forensic caseworkers in their routine decision-making process, the database has been made publicly available via the Internet in February 2000. Online searches for complete or partial Y-STR haplotypes from evidentiary or non-probative material can be performed on a non-commercial basis, and yield observed haplotype counts as well as extrapolated population frequency estimates. In addition, the YHRD website provides information about the quality control test, genotyping protocols, haplotype formats and informativity, population genetic analysis, literature references, and a list of contact addresses of the contributing laboratories.  相似文献   
842.
The absence of population-specific standards for sex, age and stature estimation for rural Guatemala is problematic for the forensic analysis of skeletal remains recovered from clandestine graves attributed to the recent armed conflict in that country. In order to increase the reliability of the forensic analyses being undertaken in Guatemala, standards for metric determination of sex were developed. Data was collected on several bones; the results for the humerus are presented here. A sample of 118 complete humeri (68 male and 50 female) was studied; maximum length, maximum diameter of the head, circumference at midshaft, maximum diameter at midshaft, minimum diameter at midshaft and epicondylar breadth were measured and subjected to discriminant function analysis. The classification accuracies for the univariate functions range from 76.8% for the maximum diameter at midshaft to 95.5% for the maximum diameter of the head. The classification accuracy for the stepwise procedure was 98.2%.  相似文献   
843.
Bacterial infections are considered to be a major cause of sudden deaths. The recognition of infections caused by Neisseria meningitidis is an essential duty of medicolegal offices due to the risk of secondary cases. Since other microorganisms, such as Haemophilus influenzae and Streptococcus pneumoniae, are also involved in infectious sudden deaths, the identification of the pathogen responsible for death is essential in order to establish a positive diagnosis while also preventing secondary meningococcal cases. However, because of the unreliability of culture methods used for autopsy specimens and the fragile nature of the microorganisms, other techniques were used. In this study, the detection of specific antigens of N. meningitidis (serogroups A, B, C, Y and W135), H. influenzae type b, S. pneumoniae and Group B Streptococcus was undertaken in 40 samples from sudden death cases in legal procedures with a latex agglutination test. In addition, a meningococcus polymerase chain reaction (PCR) assay (ctrA, crgA and siaD genes) was also used as a corroboration method for positive N. meningitidis agglutinations. Eleven cases of sudden death were confirmed to be due to meningococcus while one case was confirmed to have been caused by H. influenzae type b fulminant epiglottitis. Rapid laboratory diagnosis of meningococcal infection allowed contacts management and notification to the health authorities. From the point of view of the authors, forensic diagnosis of unascertained deaths should include latex agglutination and meningococcus PCR when a fulminant infection by N. meningitidis or H. influenzae is suspected as well as in deaths where the cause is unclear.  相似文献   
844.
For the first time in Europe, the "Meconium Project" aimed to estimate the prevalence of drug use by pregnant women and the effects of exposure to illicit drugs during pregnancy on the fetus and infant. Between October 2002 and February 2004, 1151 (79%) dyads among the 1439 mother-infant dyads from the Hospital del Mar, Barcelona, Spain, met eligibility criteria and agreed to participate in the study. We present preliminary results on the first 830 meconium samples and 549 mother-infant dyads, for which statistical analysis of socio-economic and demographic characteristics and newborn somatometry was completed. The meconium analysis showed an overall 7.9% positivity for drugs of abuse, with 6-monoacetylmorphine and cocaine being the analytes, most frequently found in samples positive for opiates and cocaine. Structured interview disclosed 1.3, 1.8 and 1.3% of mothers exposed to opiates, cocaine and both drugs, while only one mother declared ecstasy consumption. Meconium analysis showed that prevalence of opiates, cocaine and combined drugs exposure was 8.7, 4.4 and 2.2%, respectively, and confirmed the case of ecstasy use. Arecoline, the main areca nut alkaloid, was found in meconium specimens from four Asiatic newborns, whose mothers declared beetle nut consumption during pregnancy. Parental ethnicity was not associated with drug use, nor was the social class, although a higher tendency toward drug consumption was observed in professional and partly skilled mothers. Drug consuming mothers showed a higher number of previous pregnancies and abortions (p<0.05) when compared to non-consumer mothers (meconium negative test), probably due to a lack of family planning. Consumption of opiates and cocaine during pregnancy was associated with active tobacco smoking, a higher number of smoked cigarettes and cannabis use. Exposure status and smoking behavior correlated with significantly lower birth weight in newborns from mothers exposed only to cocaine and to opiates and cocaine simultaneously. Of the four newborns exposed to arecoline, one showed a low birth weight, low intrauterine growth, hyporeflexia and hypotonia.  相似文献   
845.
This study analyzed a sample of 348 college students to examine the role that criminal history and Mexican ethnicity play in predicting intimate partner violence. Respondents who committed crimes in the past (before the age of 15) had a higher probability of severely physically assaulting a partner than those respondents who had committed crime later in life (after the age of 15). A history of property crime was found to be a better predictor of severe partner assault than a history of violent crime. The results support a generalist perspective on crime, which states that most individuals typically do not commit one type of crime solely but commit a variety of different crimes (property and violent). This study also found differences between Mexican American and non-Mexican White students in reference to minor assaults on a partner.  相似文献   
846.
847.
In this paper we show that the success of the EU Regional Policy, in terms of boosting growth in objective 1 regions, will mean a big opportunity for Central and Eastern European Countries (CEECs) and hence the increases in competition arising from an enlarged European market combined with a suitable regional development policy should in the future boost the growth of those countries. In the last part of the paper we made a simulation for the funding envelope from 2007, based on the 2000–2006 budget. We show that the figures of the Agenda 2000 provide enough financial support for 90% of the total CEEC population and for 75% of current objective 1 population.  相似文献   
848.
A new set of multiplexed PCR primers has been applied to the analysis of human skeletal remains to determine their efficacy in analyzing degraded DNA. These primer sets, known as Miniplexes, produce shorter amplicons (50-280 base pairs (bp)) than standard short tandem repeat (STR) kits, but still utilize the 13 CODIS STR loci, providing results that are searchable on national DNA databases. In this study, a set of 31 different human remains were exposed to a variety of environmental conditions, extracted, and amplified with commercial and Miniplex DNA typing kits. The amplification efficiency of the Miniplex sets was then compared with the Promega PowerPlex 16 system. Sixty-four percent of the samples generated full profiles when amplified with the Miniplexes, while only 16% of the samples generated full profiles with the Powerplex 16 kit. Complete profiles were obtained for 11 of the 12 Miniplex loci with amplicon sizes less than 200 bp. These data suggest smaller PCR amplicons may provide a useful alternative to mitochondrial DNA for anthropological and forensic analysis of degraded DNA from human skeletal remains.  相似文献   
849.
850.
We report here a review of the seventh mitochondrial DNA (mtDNA) exercise undertaken by the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) corresponding to the period 2003-2004. Five reference bloodstains from five donors (M1-M5), a mixed stain of saliva and semen (M6), and a hair sample (M7) were submitted to each participating laboratory for nuclear DNA (nDNA; autosomal STR and Y-STR) and mtDNA analysis. Laboratories were asked to investigate the contributors of samples M6 and M7 among the reference donors (M1-M5). A total of 34 laboratories reported total or partial mtDNA sequence data from both, the reference bloodstains (M1-M5) and the hair sample (M7) concluding a match between mtDNA profiles of M5 and M7. Autosomal STR and Y-STR profiling was the preferred strategy to investigate the contributors of the semen/saliva mixture (M6). Nuclear DNA profiles were consistent with a mixture of saliva from the donor (female) of M4 and semen from donor M5, being the semen (XY) profile the dominant component of the mixture. Strikingly, and in contradiction to the nuclear DNA analysis, mtDNA sequencing results yield a more simple result: only the saliva contribution (M4) was detected, either after preferential lysis or after complete DNA digestion. Some labs provided with several explanations for this finding and carried out additional experiments to explain this apparent contradictory result. The results pointed to the existence of different relative amounts of nuclear and mtDNAs in saliva and semen. We conclude that this circumstance could strongly influence the interpretation of the mtDNA evidence in unbalanced mixtures and in consequence lead to false exclusions. During the GEP-ISFG annual conference a validation study was planned to progress in the interpretation of mtDNA from different mixtures.  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