全文获取类型
收费全文 | 12410篇 |
免费 | 345篇 |
专业分类
各国政治 | 474篇 |
工人农民 | 463篇 |
世界政治 | 928篇 |
外交国际关系 | 434篇 |
法律 | 8060篇 |
中国政治 | 91篇 |
政治理论 | 2253篇 |
综合类 | 52篇 |
出版年
2020年 | 152篇 |
2019年 | 210篇 |
2018年 | 259篇 |
2017年 | 272篇 |
2016年 | 275篇 |
2015年 | 174篇 |
2014年 | 272篇 |
2013年 | 1237篇 |
2012年 | 307篇 |
2011年 | 330篇 |
2010年 | 270篇 |
2009年 | 288篇 |
2008年 | 344篇 |
2007年 | 355篇 |
2006年 | 344篇 |
2005年 | 295篇 |
2004年 | 328篇 |
2003年 | 315篇 |
2002年 | 257篇 |
2001年 | 580篇 |
2000年 | 536篇 |
1999年 | 389篇 |
1998年 | 163篇 |
1997年 | 148篇 |
1996年 | 127篇 |
1995年 | 120篇 |
1994年 | 125篇 |
1993年 | 97篇 |
1992年 | 247篇 |
1991年 | 275篇 |
1990年 | 257篇 |
1989年 | 269篇 |
1988年 | 236篇 |
1987年 | 256篇 |
1986年 | 225篇 |
1985年 | 238篇 |
1984年 | 203篇 |
1983年 | 201篇 |
1982年 | 132篇 |
1981年 | 147篇 |
1980年 | 97篇 |
1979年 | 162篇 |
1978年 | 113篇 |
1977年 | 89篇 |
1976年 | 79篇 |
1975年 | 82篇 |
1974年 | 102篇 |
1973年 | 107篇 |
1972年 | 78篇 |
1971年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
Carbon monoxide (CO) poisoning typically causes so-called cherry-red livor of the skin and viscera. The authors report a case of CO poisoning in which cherry-red livor did not develop. The decedent was a 75-year-old white man who was found dead in his car during a cold winter. Blood CO saturation was 86%. The death was attributed to CO poisoning, and the manner of death was designated suicide. The curious absence of cherry-red livor was studied. The decedent's tissue and blood specimens were tested at different temperatures. There was no tendency for either type of specimen to develop cherry-red color at cold or warm temperatures. The antemortem response of the skin to cold possibly sequestered CO-saturated blood in the cadaver. As regards the viscera, there are other proteins to which CO can bond, and possibly these proteins contribute to the development of visceral cherry-red livor. In this case, the absence of cherry-red livor could have led to misclassification of the cause and manner of death. The medicolegal and social consequences of such misclassification can be significant, and psychiatric history, which may be useful to surviving family members, could be lost. 相似文献
972.
Osuna E García-Víllora A Pérez-Cárceles M Conejero J Maria Abenza J Martínez P Luna A 《The American journal of forensic medicine and pathology》2001,22(3):244-249
Diabetes mellitus is a chronic metabolic illness responsible for a great number of deaths. In postmortem diagnosis, because of the difficulty involved in interpreting blood glucose levels and relatively nonspecific pathologic features, biochemical markers in vitreous humor are useful. The aim of this study was to compare the results obtained for the combined determination of lactate and glucose with fructosamine levels recorded in the vitreous humor of two diagnostic groups (one diabetic and the other nondiabetic). The authors intended to ascertain the capacity of different markers measured in vitreous humor to diagnose diabetes mellitus. Fifty-one cadavers (mean age, 58.7 years; standard deviation, 17.09) were studied. The mean postmortem interval was 16.4 hours (standard deviation, 9.05). Cases were assigned to two diagnostic groups according to whether they were previously diagnosed as either diabetic or nondiabetic. Statistically significant differences for glucose, fructosamine, and the sum values of glucose and lactate were found between the two diagnostic groups. The highest levels were obtained in the group of cases with a previous diagnosis of diabetes mellitus. After the comparison of receiver operating characteristic curves, the sum values of glucose and lactate in vitreous humor is a better predictor of antemortem diabetes mellitus than the fructosamine. 相似文献
973.
Fetal death has been defined by the World Health Organization as death before complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of pregnancy. Certain causes of fetal death, including syphilis, Rh isoimmunization, toxemia, and diabetes, have shown significant declines over the past several decades. However, many fetal losses continue to occur from intrauterine infections, lethal malformations, fetal growth retardation, and abruptio placentae. Fetal death with no identifiable specific cause is another consideration when dealing with these cases. Other risk factors can include maternal, sociodemographic, and medical care factors. The authors reviewed all forensic cases referred for autopsy to the Forensic Section of the Medical University of South Carolina, Medical Examiners' Office over the 10-year period 1990-1999. All cases listed as fetal death or stillbirth were included. The 42 cases were analyzed as to fetus' gestational age, sex, race, weight, location of delivery, history of prenatal care, maternal drug use, chromosomal abnormalities, cause and manner of death, and autopsy findings. The black:white ratio was approximately 2:1, and the male:female ratio was virtually 1:1. Most fetuses were older than 20 weeks' gestational age, with one third between 20 and 29 weeks. The majority were externally normal aside from maceration. Only 7.5% had congenital anomalies. Twenty-one of 38 placentas were grossly and microscopically normal. Of cases with toxicologic analysis, 21% were positive for drugs, and 17% were positive for cocaine/benzoylecgonine. The manner of death was classified as natural (28), accident (2), and undetermined (12). Few studies have reported the specific causes of fetal death, and the lack of uniformity in data collection and classification of causes of fetal death has made comparisons difficult. The authors present this retrospective study to better determine the factors leading to fetal demise in the hope of assisting death investigators in this challenging arena. 相似文献
974.
Posttraumatic thrombosis of the middle cerebral artery 总被引:6,自引:0,他引:6
Bunai Y Nagai A Nakamura I Akaza K Ohya I 《The American journal of forensic medicine and pathology》2001,22(3):299-302
Posttraumatic cerebral infarction resulting from carotid or cerebral artery occlusion is rare. Traumatic dissection of the carotid artery is the most frequent cause of infarction, whereas posttraumatic thrombosis of the cerebral artery is very rare. The authors describe a case of posttraumatic thrombosis of the left middle cerebral artery. Early in the morning, a 16-year-old boy was found unconscious in the parking lot of a supermarket. He had received fist blows and kicks to the head, face, body, back, and hip during the night. Computed tomography 10 hours after the violence revealed a gross cerebral infarction in the area of the left middle cerebral artery. He died 9 days after the violence. The autopsy revealed a thrombosis in the left middle cerebral artery. Microscopically, granulation tissue in the intima and a rupture of the internal elastic lamina were observed near the beginning of the artery. It was concluded that the blows to the head and face caused a partial rupture in the arterial wall, leading to thrombosis and cerebral infarction. 相似文献
975.
976.
Jayaprakash PT Srinivasan GJ Amravaneswaran MG 《Forensic science international》2001,117(1-2):121-143
Skull-photograph superimposition continues to be the most prevalent method employed for identifying a skull recovered in a criminal case as that belonging to a putative victim whose face photograph is available. The reliability of identification achieved has been shown to be 91%, indicating the possibility of a skull mismatching with a face photograph belonging to a person other than the actual deceased. This lack of reliability dampens the confidence of the expert and in turn confounds the mind of the judge. It has been shown that the variations in the shape of the facial organs are influenced by the corresponding variations in the skeletal elements of the facial skull. "Cranio-facial morphanalysis", a new anthroposcopic method proposed here for evaluating the shape correlations between a skull and a face photograph, when applied conjointly with skull-photograph superimposition is shown to increase the reliability in forensic skull identification. 相似文献
977.
Jedrzejowska ZK 《Forensic science international》2001,117(1-2):145-151
The aim of this work is to prove the application of craniometry in determining the identity of unknown bodies. There is a great correlation between the viscero-cranium appearance and the osseous structure, the said correlation following mathematical rules and thus being possible to be calculated. Various segments of the skull and different size of the angles they make with each other are directly responsible for the graphic profile of viscero-cranium. The nasal bones and their angle are the basis to determine the shape and size of the nose. 相似文献
978.
To evaluate pathophysiological significance of post-mortem urinary myoglobin levels in determining the cause of death, we investigated 210 forensic autopsy cases, partially in comparison with serum levels. Post-mortem serum myoglobin levels were extraordinary high in most cases possibly due to post-mortem change. Urinary myoglobin levels did not correlate with the serum levels, showing possible post-mortem elevation in cases of a prolonged post-mortem period over 48h. A high (>1000 ng/ml), moderate (100-1000 ng/ml), slight (50-100 ng/ml) and not significant (<50 ng/ml) elevation of urinary myoglobin were observed in 26, 43, 31 and 110 cases, respectively. Half the highly elevated cases were those with a survival time over 24h. In cases of minor muscle injury such as head trauma, elevation of urinary myoglobin level was closely related to longer survival. In acute/subacute deaths with a post-mortem interval within 48h, a significant difference was observed in relation to the blood carboxyhemoglobin (COHb) levels of fire victims: myoglobinuria over 100 ng/ml was more frequently and markedly observed in cases with COHb below 60% than over 60%, suggesting muscle damage in fatal burns. Similar elevation was observed in heat stroke victims, and also in some cases of acute and subacute death from polytrauma, asphyxiation, drowning, electricity and spontaneous cerebral bleeding, but not in myocardial infarction. Thus, it was suggested that high post-mortem urinary myoglobin levels in acute and subacute death cases may be a possible indicator of antemortem massive skeletal muscle damage as well as exertional muscle hyperactivity or convulsive disorders associated with hypoxia. 相似文献
979.
Schmidt P Schmolke C Musshoff F Prohaska C Menzen M Madea B 《Forensic science international》2001,115(3):219-229
In animal and cell culture experiments, chronic morphine treatment has been followed by 'up'- as well as 'down-regulation' of the mu opioid receptor (mu OR) number. The present postmortem morphometric study of morphine-related fatalities of drug addicts (n=12, and 22-35 years old, with blood unconjugated morphine levels from 27.1 to 458 ng/ml, m.v. 198.5 ng/ml) versus a non-addicted control group (n=13 and 10-44 years old) was intended to examine whether chronic opiate exposure affects the numerical density of mu OR expressing neurons in the human neocortex (area 10 according to Brodmann). For the immunohistochemical procedure, thick (100 microm) vibratome sections were incubated with a monoclonal antibody against the mu OR [Arvidsson et al., J. Neurosci. 15 (1995) 3328] and immunoreactive sites were visualized using an immunoperoxidase protocol. The numerical densities of mu OR-expressing and Nissl-stained neurons were assessed morphometrically (camera lucida-drawings). In both collectives, the anti-mu OR immunoreactivity was mainly found in pyramidal neurons of layers (L) II/III and V and in multiform neurons of L VI. In the drug-related fatalities and the control group, the density of neurons expressing mu OR protein was similar, amounting for 2698 +/- 153 and 2688 +/- 172/mm(3), respectively. These findings extend the binding studies of opioid ligands in postmortem brains of heroin addicts [Gabilondo et al., Psychopharmacology 115 (1994) 135] revealing similar receptor densities and affinities by showing no difference in the density of mu OR-positive neurons. 相似文献
980.
The key component of the PharmChek sweat patch, the membrane, has been tested for the passage of externally applied materials. Drugs in the uncharged state rapidly penetrated the membrane but charged species were greatly slowed. In basic media, detectable concentrations of cocaine, methamphetamine, and heroin were observed at the earliest collection time (ca. 30 s), after drugs were placed on the outside of the membrane. Drug concentrations increased over the 2 h time course, when amounts detected (1710 ng cocaine, 1060 ng methamphetamine, 550 ng heroin per pad at 2 h) represented 5-17% of the drug deposited on the surface of the sweat patch.Drugs externally applied to human skin were shown to bind readily. Drugs deposited on the skin of drug-free volunteers several days prior to application of the sweat patch were not completely removed by normal hygiene or the cleaning procedures recommended before application of the sweat patch. Even 6 days of normal hygiene did not remove all drugs from externally contaminated skin and positive sweat patches resulted. A mechanism for passage of drugs through the sweat patch membrane, a mechanism for retention of drugs on skin, and a redesign of the sweat patch and modification of its use to reduce external contamination are proposed. Appropriate care should be taken in the interpretation of positive results from a sweat patch test until more research is conducted. 相似文献