全文获取类型
收费全文 | 8686篇 |
免费 | 429篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 168篇 |
儿科学 | 375篇 |
妇产科学 | 407篇 |
基础医学 | 1422篇 |
口腔科学 | 135篇 |
临床医学 | 614篇 |
内科学 | 1629篇 |
皮肤病学 | 172篇 |
神经病学 | 766篇 |
特种医学 | 606篇 |
外国民族医学 | 3篇 |
外科学 | 1047篇 |
综合类 | 44篇 |
一般理论 | 4篇 |
预防医学 | 422篇 |
眼科学 | 280篇 |
药学 | 468篇 |
中国医学 | 76篇 |
肿瘤学 | 490篇 |
出版年
2022年 | 55篇 |
2021年 | 82篇 |
2020年 | 61篇 |
2019年 | 122篇 |
2018年 | 121篇 |
2017年 | 91篇 |
2016年 | 115篇 |
2015年 | 151篇 |
2014年 | 185篇 |
2013年 | 278篇 |
2012年 | 384篇 |
2011年 | 407篇 |
2010年 | 264篇 |
2009年 | 255篇 |
2008年 | 363篇 |
2007年 | 381篇 |
2006年 | 392篇 |
2005年 | 404篇 |
2004年 | 369篇 |
2003年 | 383篇 |
2002年 | 353篇 |
2001年 | 184篇 |
2000年 | 185篇 |
1999年 | 185篇 |
1998年 | 126篇 |
1997年 | 113篇 |
1996年 | 63篇 |
1995年 | 64篇 |
1994年 | 63篇 |
1993年 | 54篇 |
1992年 | 133篇 |
1991年 | 88篇 |
1990年 | 109篇 |
1989年 | 116篇 |
1988年 | 103篇 |
1987年 | 84篇 |
1986年 | 77篇 |
1985年 | 87篇 |
1984年 | 58篇 |
1983年 | 59篇 |
1981年 | 44篇 |
1979年 | 63篇 |
1978年 | 52篇 |
1977年 | 55篇 |
1975年 | 66篇 |
1973年 | 43篇 |
1971年 | 49篇 |
1930年 | 43篇 |
1929年 | 45篇 |
1928年 | 45篇 |
排序方式: 共有9128条查询结果,搜索用时 15 毫秒
31.
32.
33.
Tadashi Nakazawa Yoshiyuki Takami Robert Benkowski Satoshi Ohtsubo Ohashi Yukio Eiki Tayama Goro Ohtsuka Yoshinari Niimi Julie Glueck Akinori Sueoka Helmut Schmallegger Heinrich Schima Ernst Wolner Yukihiko Nosé 《Artificial organs》1997,21(7):597-601
Abstract: To be able to salvage heart failure patients, the need for an economical permanent ventricular assist device is increasing. To meet this increasing demand, a miniaturized centrifugal blood pump has been developed as a permanently implantable device. The Gyro permanently implantable model (PI-601) incorporates a sealless design with a blood stagnation free structure. The pump impeller is magnetically coupled to the driver magnet in a sealless manner. This pump is atraumatic and antithrombogenic and incorporates a double pivot bearing system. A miniaturized actuator was utilized in this system in collaboration with the University of Vienna. The priming volume of this pump is 20 ml. The overall size of the pump actuator package is 53 mm in height and 65 mm in diameter, 145 ml of displacement volume, and 305 g in weight. Testing to date has included in vitro hydraulic performance and hemolysis. This pump can provide 5 L/min against a 110 mm Hg total pressure head at 2,000 rpm and 8 Limin against 150 mm Hg at 2,500 rpm. The normalized index of hemo-lysis (NIH) value of this pump was 0.0028 g/100 L at 5 Limin against 100 mm Hg. A preliminary anatomical study revealed the possibility of the implantability of 2 such systems in biventricular bypass at a preperitoneal location. This system is feasible for use as a permanently implantable biventricular assist device. 相似文献
34.
Christoph Eisenbach Peter Sauer Arianeb Mehrabi Wolfgang Stremmel Jens Encke 《Clinical transplantation》2006,20(S17):111-116
Abstract: Liver transplantation for hepatitis B virus (HBV)-related liver disease has changed from a contraindication to outcomes comparable with non-HBV-related liver transplantations during the last two decades. Mainly the implementation of immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and the use of nucleoside analogs such as lamivudine and adefovir account for this dramatic change. The standard of care in most centers today consists of lamivudine treatment in replicating hepatitis B pre-orthotopic liver transplantation (OLT) and a combination regimen of lamivudine and HBIG post-OLT. With adefovir, a potent antiviral drug became available in recent years that allows for the treatment of patients with lamivudine-resistant tyrosine-methionine-aspartate-aspartate (YMDD)-mutant HBV. In the transplantation setting, first studies indicate that a triple prophylactic therapy consisting of lamivudine, adefovir, and HBIG will become the standard of care for YMDD-mutant-related hepatitis B. With new drugs emerging for the treatment of chronic HBV, there is optimism for new options also in the transplant setting. 相似文献
35.
Sigrid C. Schwarz Hansjörg Sauer Wolfgang H. Oertel Christopher D. Earl Andreas R. Kupsch 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1997,115(1):71-82
We employed intracerebral co-transplantation of foetal xenogeneic striatal mouse tissue and allogeneic rat substantia nigra
into the adult rat brain to elucidate the effects of xenogeneic mouse graft on the function and survival of an allogeneic
rat graft in 6-hydroxydopamine lesioned Sprague-Dawley rats. Foetal mouse striatum (STR) and rat substantia nigra (VM) were
transplanted as non-pooled separate deposits or a pooled cell suspension with or without cyclosporin A (Cy A). Immunosuppressed
recipients of pooled rat and mouse co-grafts showed a significantly better compensation of amphetamine-induced rotational
behaviour compared with non-immunosuppressed animals with pooled rat and mouse co-grafts 3 and 6 weeks post-grafting.Tyrosine
hydroxylase (TH) immunohistochemistry revealed a non-significant reduction in survival in pooled (1806.3±367.5 cells) rat
and mouse co-transplants without immunosuppression compared with immunosuppressed pooled (3383.3±732.7 cells) animals with
allo- and xenogeneic tissue and controls (3506.4±839.3 cells). Graft volumes were significantly reduced in pooled transplants
without immunosuppression (0.1±0.026 mm3; ANOVA post-hoc SchefféF-test, P<0.0001) compared with immunosuppressed recipients (0.7±0.1 mm3) and controls (0.6±0.1 mm3). In non-pooled allo- and xenogeneic grafts without immunosuppression the survival rate of the TH-immunoreactive cells and
graft volumes were reduced (2359.3±479.5 cells; 0.2±0.043 mm3) compared with immunosuppressed animals (2927.3±946.6 cells; 0.6±0.2 mm3) and controls (2701.1±693.8 cells; 0.3±0.1 mm3) without reaching a level of significance. Rejection of mouse tissue was observed in all non-immunosuppressed recipients.
In summary: (i) continued immunosuppression yielded significant beneficial effects on function and beneficial effects on survival
of pooled grafts with an immunogenetic disparity; (ii) the rejection of a xenogeneic graft component may compromise survival
and function of other, allogeneic graft components; and (iii) transplantation of non-pooled allo- and xenogeneic tissues may
result in a better survival of the graft compared with pooled cell suspensions.
Received: 25 March 1996 / Accepted: 1 December 1996 相似文献
36.
Internal fixation of dorsolumbar spinal fractures can be accomplished by dorsal plating or internal fixator. So far, the technique of transpedicular grafting has been applied to fill the vertebral body with cancellous bone. In this paper, we present a new technique of extended transpedicular bone grafting to fill the intervertebral space also. By this means, the disadvantage of secondary loss of height after removal of the metal implants can be prevented. 相似文献
37.
The findings at clinical and roentgenological follow-up examination of 44 patients are reported to illustrate the long-term results of a modified Watson-Jones technique up to 90 months after the operation. The clinical results (86.3% of the patients without complaints and 88.6% with subjective stability of the ligaments) correspond with those given by a variety of sources in the literature. The roentgenological examination, on the other hand, showed signs of grade I or II arthrosis (Bargon scale) in 61.3% of cases, and arthrosis was worse than before the operation in nearly all cases. The patients in the group, that had received more conservative treatment with an average 6.3 years between lesion and surgical treatment (group 1), had the highest incidence of arthrosis, with 73.6%. In 10 cases the clinical examination revealed reduced supination and dorsiflexion attributable to the tenodesis effect associated with the Watson-Jones technique. In view of the high rate of arthrosis, younger patients and patients with a short tendon part of the peroneus brevis muscle should be treated by another, more "physiological" method. 相似文献
38.
Clone-based systematic haplotyping (CSH): a procedure for physical haplotyping of whole genomes 总被引:4,自引:0,他引:4 下载免费PDF全文
Burgtorf C Kepper P Hoehe M Schmitt C Reinhardt R Lehrach H Sauer S 《Genome research》2003,13(12):2717-2724
We present a novel methodology to determine the phase of single-nucleotide polymorphisms (SNPs) on a chromosome, which we term clone-based systematic haplotyping (CSH). The CSH procedure is based on separating the allelic chromosomes of a diploid genome by fosmid/cosmid cloning, and subsequent SNP typing of 96 clone pools, each representing approximately 10% of the genome. The pools are screened by PCR for the sequence of interest, followed by SNP typing on the PCR products using the GOOD assay. We demonstrate that by CSH, the haplotype of SNPs separated by more than 50 kilobases can definitely be assigned. We propose this method as being suitable for constructing maps of ancestral haplotypes, analysis of complex diseases, and for diagnosis of rare defects in which the molecular haplotype is crucial. In addition, by amplifying the initial DNA by many orders of magnitude, the original DNA resource is effectively immortalized, enabling the haplotyping of hundreds of thousands of SNPs per individual. 相似文献
39.
40.
Predator odors have been shown to elicit stress responses in rats. The present studies assessed the use of domestic ferret odor as a processive stress model. Plasma corticosterone and adrenocorticotropin hormone levels were higher after 30 min of exposure to ferret odor (fur/skin) but not control odors, ferret feces, urine, or anal gland secretions. Behavioral differences were also found between ferret and the control odors as tested in a defensive withdrawal paradigm. In addition, c-fos messenger RNA expression in several brain areas previously associated with processive stress was significantly higher in ferret odor-exposed rat brains than in control odor-exposed brains. These results suggest that ferret odor produces a reliable unconditioned stress response and may be useful as a processive stress model. 相似文献