全文获取类型
收费全文 | 7602篇 |
免费 | 711篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 85篇 |
儿科学 | 208篇 |
妇产科学 | 112篇 |
基础医学 | 923篇 |
口腔科学 | 155篇 |
临床医学 | 910篇 |
内科学 | 1798篇 |
皮肤病学 | 98篇 |
神经病学 | 712篇 |
特种医学 | 306篇 |
外科学 | 1002篇 |
综合类 | 112篇 |
一般理论 | 4篇 |
预防医学 | 819篇 |
眼科学 | 294篇 |
药学 | 474篇 |
中国医学 | 1篇 |
肿瘤学 | 317篇 |
出版年
2021年 | 121篇 |
2020年 | 68篇 |
2019年 | 109篇 |
2018年 | 134篇 |
2017年 | 108篇 |
2016年 | 101篇 |
2015年 | 111篇 |
2014年 | 168篇 |
2013年 | 255篇 |
2012年 | 368篇 |
2011年 | 424篇 |
2010年 | 178篇 |
2009年 | 182篇 |
2008年 | 321篇 |
2007年 | 320篇 |
2006年 | 360篇 |
2005年 | 325篇 |
2004年 | 325篇 |
2003年 | 312篇 |
2002年 | 326篇 |
2001年 | 256篇 |
2000年 | 266篇 |
1999年 | 208篇 |
1998年 | 75篇 |
1997年 | 66篇 |
1996年 | 56篇 |
1995年 | 65篇 |
1994年 | 58篇 |
1993年 | 71篇 |
1992年 | 177篇 |
1991年 | 173篇 |
1990年 | 175篇 |
1989年 | 154篇 |
1988年 | 163篇 |
1987年 | 148篇 |
1986年 | 150篇 |
1985年 | 130篇 |
1984年 | 92篇 |
1983年 | 95篇 |
1982年 | 77篇 |
1981年 | 52篇 |
1979年 | 63篇 |
1978年 | 78篇 |
1977年 | 70篇 |
1976年 | 59篇 |
1974年 | 62篇 |
1973年 | 62篇 |
1972年 | 53篇 |
1971年 | 67篇 |
1969年 | 51篇 |
排序方式: 共有8330条查询结果,搜索用时 46 毫秒
41.
42.
C Whitehead BA L D Sanders PhD M Rosen CBE FCAnaes J O Robinson PhD 《International journal of clinical practice》1991,45(4):263-264
SUMMARY In order to assess the reliability of drug information supplied by day-stay cases, 85 consecutive patients were interviewed. A comparison of the interview answers with the details previously volunteered during the admission procedure showed an increase of 80% in the information given by the patient. While the detailed interviewing technique is time-consuming and may not be infallible, this substantial increase in information highlights problems in the current routine. 相似文献
43.
Laparoscopic bile duct injuries. Risk factors, recognition, and repair. 总被引:18,自引:0,他引:18
R L Rossi W J Schirmer J W Braasch L B Sanders J L Munson 《Archives of surgery (Chicago, Ill. : 1960)》1992,127(5):596-601; discussion 601-2
Records of 11 patients undergoing biliary reconstruction after laparoscopic cholecystectomy are reviewed. Ductal injuries resulted from failure to define the anatomy of Calot's triangle. Risk factors include scarring, acute cholecystitis, and obesity. Presenting findings included anorexia, ileus, failure to thrive, pain, ascites, and jaundice. All patients required hepaticojejunostomies, which were multiple and above the hepatic bifurcation in four patients. Given the extensive nature of these injuries and the frequent need for intrahepatic anastomosis and early stenosis of repairs by referring physicians, we recommend reconstruction be undertaken by an experienced hepatobiliary surgeon. To avoid injuries, a greater appreciation of risk factors and anatomic distortion and variance and strict adherence to principles of dissection and identification of anatomic structures are suggested. The use of cholangiography and a low threshold for conversion to the open procedure are advised. 相似文献
44.
Nicotine discrimination and self-administration in humans as a function of smoking status 总被引:2,自引:2,他引:0
Nicotine’s discriminative stimulus effects may be critical to understanding reinforcement of tobacco smoking. It is not known
whether regular nicotine exposure produces tolerance or sensitivity to these effects. In this study, male and female smokers
(n = 11) and never-smokers (n = 10) were trained to discriminate 20 μg/kg nicotine by nasal spray from placebo (0) on day 1. On day 2, both groups were
tested on generalization of this discrimination across intermittent presentations of 0, 3, 6, 12, and 20 μg/kg nicotine in
random order. Quantitative and quantal behavioral discrimination tasks, used in previous research, were employed. On day 3,
subjects were instructed to self-administer sprays from the 20 μg/kg nicotine versus 0 bottles in a concurrent-choice procedure.
All but one subject (female smoker) learned reliably to discriminate 20 μg/kg nicotine from placebo (≥ 80% correct) on day 1. Nicotine-appropriate responding on day 2 was attenuated in smokers versus never-smokers at 20 μg/kg
on the quantitative task and at 12 μg/kg on the quantal task, suggesting tolerance. There was no difference in responding
at other doses. Smokers also showed attenuated responses on the subjective measure of “head rush”, which was associated with
discrimination responding in both groups. Nicotine self-administration was significantly greater in smokers versus never-smokers,
who self-administered nicotine below chance levels, and was inversely related to discrimination behavior in never-smokers
but unrelated in smokers. Women smokers showed less change in nicotine-appropriate responding across generalization doses,
reported less confidence in discriminating training doses during acquisition on day 1, and tended to self-administer less
nicotine on day 3. These results indicate that smokers may become tolerant to the discriminative stimulus effects of nicotine,
perhaps promoting increased use.
Received: 1 October 1996/Final version: 28 January 1997 相似文献
45.
J H Sanders 《North Carolina medical journal》1989,50(10):584-585
46.
J E Sanders 《Paediatrician》1991,18(1):76-81
As increasing numbers of children are surviving beyond the 1st decade after marrow transplantation and increasing numbers of children are receiving marrow transplants each year, the delayed effects related to the transplant procedure itself, the original disease, and/or the transplant preparative regimen are becoming apparent. Late effects related to the transplant procedure include those of engraftment stability, the chronic immunosuppression of chronic graft-versus-host disease and delayed immunologic recovery. Recurrent disease is the major late effect related to the patient's original disease. The late effects which may be related to previous therapy administered and/or the transplant preparative regimen include abnormalities of neuroendocrine function, ocular problems, dental developmental abnormalities in young children, central nervous system dysfunction and the development of secondary malignancies. To improve the quality of life of marrow transplant recipients and to prevent some of the growth and development abnormalities which may occur, an awareness of the problems encountered to date is needed. 相似文献
47.
Malanda Nsuami Migel Elie Bridget N Brooks Ladatra S Sanders Theresa D Nash Feseha Makonnen Stephanie N Taylor Deborah A Cohen 《The Journal of adolescent health》2003,32(5):336-339
In an urban school district, 636 students in grades 9-12 were tested for Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction assays using specimens collected for routine urinalyses during sports physical examinations. Chlamydia and gonorrhea prevalences were 2.8% and 0.7% among males, and 6.5% and 2.0% among females, respectively. Among athletes infected with either sexually transmitted disease (STD), 93.1% reported no symptoms, and treatment was documented for 75.9%. Sports physicals offered a unique opportunity to screen and treat adolescents for STDs and to provide STD-prevention counseling. 相似文献
48.
C. C. Sanders W. E. Sanders Jr. 《European journal of clinical microbiology & infectious diseases》1987,6(4):435-438
The clinical problems caused by inducible beta-lactamases in certain gram-negative bacteria are being recognized with increasing frequency. These problems include the rapid emergence of multiple beta-lactam resistance during therapy with many of the newer beta-lactam antibiotics. Such multiply resistant organisms are now spreading within the hospital and have become important nosocomial pathogens. This has been a particularly difficult problem for intensive care units, cystic fibrosis centers and burn units where there are clusters of patients who are highly susceptible to infections with organisms likeEnterobacter spp.,Serratia spp. andPseudomonas aeruginosa, which possess inducible beta-lactamases. Only through an awareness of these problems, their cause, and restriction of the use of certain newer betalactam antibiotics can these problems be controlled. 相似文献
49.
Polyacrylamide gel electrophoresis of acid phosphatase from prostatic tissue reveals one more band than seminal plasma. It was attempted to ascertain which subcellular fraction was responsible for that intracellularly localized enzyme. Prostatic epithelium from patients with prostatic hyperplasia was homogenized, and a lysosomal and microsomal fraction were prepared by differential centrifugation. These two fractions were further centrifuged on an isopycnic Percoll gradient. The intracellularly localized form of acid phosphatase was associated with the lysosomal as well as with the microsomal fraction. In a fused rocket electrophoresis experiment these acid phosphatases cross-reacted with antiserum from seminal plasma. After neuraminidase treatment of the acid phosphatase of lysosomal and microsomal origin, only one activity band was found in polyacrylamide gels. It is concluded that only one acid phosphatase protein exists in prostatic epithelium; differences in electrophoretic mobility are caused mainly by different amounts of sialic acid residues, coupled to the same protein backbone. 相似文献
50.
Aspehaug V Falk K Krossøy B Thevarajan J Sanders L Moore L Endresen C Biering E 《Virus research》2004,106(1):51-60
Infectious salmon anemia virus (ISAV) is the type species of the genus Isavirus belonging to the Orthomyxoviridae, and causes serious disease in Atlantic salmon (Salmo salar). This study presents the expression and functional analysis of the ISAV genome segment 3, and provides further evidence that it encodes the viral nucleoprotein (NP). The encoded protein was expressed in a baculovirus system, and Western blot analysis showed that it corresponds to the 66-71 kDa structural protein previously found in purified ISAV preparations. RNA-binding activity was established by the interaction of viral and recombinant NP with single-stranded RNA transcribed in vitro. Immunofluorescence studies of infected cells showed the ISAV NP to be an early protein. It locates to the nucleus of infected cells before it is transported to the cytoplasm prior to virus assembly. A similar localization pattern was observed in cells transfected with the NP gene, confirming that the encoded protein has an intrinsic ability to be imported into the nucleus. Two monopartite nuclear localization signals (NLS) at amino acids (230)RPKR(233) and (473)KPKK(476) were identified by computer analysis, and validated by site-directed mutagenesis. In contrast to other orthomyxovirus-NPs, that have several NLSs that function independent of each other, both NLSs had to be present for the ISAV NP protein to be transported into the nucleus, indicating that these motifs cooperate to target the protein to the nucleus. 相似文献