全文获取类型
收费全文 | 3658篇 |
免费 | 346篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 96篇 |
妇产科学 | 68篇 |
基础医学 | 576篇 |
口腔科学 | 67篇 |
临床医学 | 481篇 |
内科学 | 802篇 |
皮肤病学 | 44篇 |
神经病学 | 191篇 |
特种医学 | 317篇 |
外科学 | 429篇 |
综合类 | 106篇 |
一般理论 | 35篇 |
预防医学 | 335篇 |
眼科学 | 54篇 |
药学 | 239篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 123篇 |
出版年
2022年 | 28篇 |
2021年 | 48篇 |
2020年 | 28篇 |
2019年 | 51篇 |
2018年 | 62篇 |
2017年 | 57篇 |
2016年 | 50篇 |
2015年 | 72篇 |
2014年 | 78篇 |
2013年 | 123篇 |
2012年 | 137篇 |
2011年 | 131篇 |
2010年 | 75篇 |
2009年 | 91篇 |
2008年 | 117篇 |
2007年 | 143篇 |
2006年 | 125篇 |
2005年 | 115篇 |
2004年 | 102篇 |
2003年 | 96篇 |
2002年 | 114篇 |
2001年 | 105篇 |
2000年 | 113篇 |
1999年 | 102篇 |
1998年 | 70篇 |
1997年 | 68篇 |
1996年 | 55篇 |
1995年 | 53篇 |
1994年 | 52篇 |
1993年 | 62篇 |
1992年 | 101篇 |
1991年 | 106篇 |
1990年 | 98篇 |
1989年 | 107篇 |
1988年 | 99篇 |
1987年 | 105篇 |
1986年 | 84篇 |
1985年 | 82篇 |
1984年 | 62篇 |
1983年 | 62篇 |
1982年 | 37篇 |
1981年 | 40篇 |
1980年 | 34篇 |
1979年 | 43篇 |
1978年 | 50篇 |
1977年 | 29篇 |
1974年 | 31篇 |
1973年 | 32篇 |
1972年 | 27篇 |
1967年 | 25篇 |
排序方式: 共有4017条查询结果,搜索用时 15 毫秒
11.
12.
Diagnostic performance of nocturnal penile tumescence studies in healthy, dysfunctional (impotent), and depressed men 总被引:1,自引:0,他引:1
M E Thase C F Reynolds J R Jennings S R Berman P R Houck J R Howell E Frank D J Kupfer 《Psychiatry research》1988,26(1):79-87
Nocturnal penile tumescence (NPT) studies were evaluated in 17 men with a clinical diagnosis of organic erectile dysfunction in comparison to age-matched healthy controls (n = 17) and depressed men (n = 17). The dysfunctional group had significantly fewer NPT episodes and reduced maximal penile tip changes when compared to healthy controls and depressed patients. Further, the dysfunctional group had significantly diminished erectile fullness and reduced penile rigidity. Diagnostic performance of polygraphic (night 1) and visual inspection (nights 2 or 3) components of the NPT protocol were examined in these criterion groups. A diagnostic classification based on polygraphic measures successfully discriminated 73.5% of dysfunctional and healthy control subjects, but classified 47% of depressives in the dysfunctional range. Use of visual inspection indices correctly identified 88% of the dysfunctional sample and 94% of normal controls, and reduced the "false-positive" rate in depression to only 18%. Results support the diagnostic utility of NPT studies, particularly when enhanced by visual inspection procedures. Nevertheless, the presence of major depression may confound interpretation of such studies. 相似文献
13.
Nitric oxide participates in the intestinal pathology associated with murine syngeneic graft-versus-host disease 总被引:5,自引:0,他引:5
Flanagan DM Jennings CD Goes SW Caywood BE Gross R Kaplan AM Bryson JS 《Journal of leukocyte biology》2002,72(4):762-768
Syngeneic graft-versus-host disease (SGVHD) develops following lethal irradiation, reconstitution with syngeneic bone marrow, and treatment with a short course of cyclosporin A (CsA) therapy. The disease is characterized by the development of a T helper cell type 1-like cytokine response [interleukin (IL)-12, interferon-gamma (IFN-gamma), and tumor necrosis factor alpha], and macrophage activation is central to development of the syndrome. It has been shown that nitric oxide (NO) participates significantly in the development of allogeneic GVHD. Studies were initiated to determine if NO participates in the pathology associated with SGVHD. Significant increases in inducible NO synthase (iNOS) mRNA and circulating NO were found in the tissues of SGVHD versus control animals. Treatment of SGVHD animals with the iNOS inhibitor aminoguanidine (AG) reversed the pathology associated with this disease. Furthermore, AG treatment reduced the production of IL-12 and IFN-gamma mRNA in the colons of CsA-treated mice. These studies demonstrate that NO participates in the pathological processes that are associated with the development of murine SGVHD. 相似文献
14.
Conjugation of meningococcal lipopolysaccharide R-type oligosaccharides to tetanus toxoid as route to a potential vaccine against group B Neisseria meningitidis. 总被引:2,自引:17,他引:2 下载免费PDF全文
Oligosaccharides were obtained by the mild acid hydrolysis of the lipopolysaccharides from a number of different strains of Neisseria meningitidis, serotypes L2, L3, L4, L5, and L10. The dephosphorylated oligosaccharides were conjugated to tetanus toxoid as their 2-(4-isothiocyanatophenyl)-ethylamine derivatives, which resulted in the incorporation of from 18 to 38 oligosaccharides per molecule of tetanus toxoid. When injected in rabbits, the conjugates produced oligosaccharide-specific antibodies which were predominantly serologically specific but which also exhibited some cross-reactivity. These serological results can be attributed to regions of structural dissimilarity and similarity within the oligosaccharides. The oligosaccharide-specific antibodies were also lipopolysaccharide serotype specific, thus indicating that the oligosaccharides are the determinants associated with this serotype specificity. Consistent with the serological results, the conjugate antisera were bactericidal for the homologous serotype meningococcal organisms and in some cases for heterologous serotype organisms. 相似文献
15.
Carlson DJ Stewart RD Li XA Jennings K Wang JZ Guerrero M 《Physics in medicine and biology》2004,49(19):4477-4491
Parallel in vitro and in vivo studies provide insight into the relationship between clinical response and intrinsic cellular radiosensitivity and may aid in the development of predictive assays. Compilations of radiosensitivity parameters from in vitro experiments can also be used to examine the potential effectiveness of alternative or new treatment plan designs until enough clinical data become available to directly estimate the requisite radiosensitivity parameters. In this work, survival data for six prostate cancer cell lines (ten datasets total) have been extracted from the literature and re-analysed using the linear-quadratic (LQ) survival model. The paired bootstrap technique for regression is used to compute 95% confidence intervals for the estimated radiosensitivity parameters. LQ radiosensitivity parameters derived from the in vitro data are then compared to radiosensitivity parameters derived from clinical data for prostate cancer. Estimates of alpha range from 0.09 to 0.35 Gy(-1) (all cell lines), and the alpha/beta ratio ranges from 1.09 to 6.29 Gy (all cell lines). Point estimates of the repair half-time (PPC-1, TSU-Pr1, PC-3 and DU-145 cell lines) range from 5.7 to 8.9 h (95% confidence interval from 0.26 h to 10.7 h). Differences in the radiosensitivity parameters determined from the data reported by different laboratories are as large as or larger than the differences in radiosensitivity parameters observed among the various prostate cell lines. The reported studies demonstrate that even seemingly small corrections for dose rate effects, such as those expected in high dose rate (HDR) experiments, can sometimes have a significant impact on estimates of alpha and alpha/beta. By neglecting dose rate effects in the analysis of HDR experiments, estimates of the alpha/beta, ratio may be too high by factors as large as 1.3 to 6.2. The half-time for repair derived from the in vitro experiments appears significantly larger (slower repair rate) than estimates derived from the clinical data. However, the prostate radiosensitivity parameters alpha and alpha/beta may be approximately the same in vitro and in vivo. Most of the in vitro data are consistent with an alpha/beta ratio for prostate cancer less than 3 or 4 Gy. 相似文献
16.
Filamentous phage displaying peptides representing single epitopes of the glycoprotein G of HSV-2 (gG2) were used as immunogens via the subcutaneous route in Balb/c mice without additional adjuvant. The phage were isolated from a random phage peptide display library and contain 15-mer peptide inserts that mimic epitopes of gG2. In each case, an antibody response to gG2 was generated that was dependent on the dose of phage administered and on the presence of the peptide insert. Phage displaying epitopes of gG2, which map to amino acids 551-570, were the most immunogenic; interestingly, this region of gG2 is frequently recognised by patients infected with HSV-2. The data also provide interesting information as regards choice of peptide mimics for use as immunogens because, surprisingly, the most antigenic of the individual clones was the least immunogenic. In two of the experiments, mice immunised with phage displaying a single epitope of gG2 were protected against challenge with a lethal dose of whole HSV-2. This suggests a possible role for phage-displayed peptides in inducing protective immunity against pathogens and provides a model system for investigating the underlying mechanisms. 相似文献
17.
Immunity to Influenza in Ferrets X. Intranasal Immunization of Ferrets with Inactivated Influenza A Virus Vaccines 下载免费PDF全文
The response of ferrets after intranasal inoculation of inactivated A/Hong Kong/68 (H3N2) influenza virus vaccines is reported. Normal ferrets given either saline vaccine in drops or freeze-dried vaccine in an aerosol intranasally did not produce detectable serum or nasal hemagglutination inhibiting antibody and were found to be completely susceptible to challenge infection with A/Hong Kong/68 virus. Intranasal saline vaccine did not produce an additive effect on the response of ferrets simultaneously given the same vaccine intramuscularly with adjuvant. Ferrets primed by previous infection with A/PR/8/34 (H0N1) influenza virus, however, responded to intranasal immunization with saline A/Hong Kong/68 virus vaccine and produced serum and nasal antibody. These animals were found to be partially resistant to challenge infection, in contrast to similar animals given saline vaccine intramuscularly which were completely resistant to challenge infection. Primed ferrets did not respond after immunization with the freeze-dried aerosol vaccine, but this may have been due to a failure of the aerosol to be inhaled satisfactorily. 相似文献
18.
19.
C A Axiotis J Fuks T A Jennings A S Kadish 《Archives of pathology & laboratory medicine》1988,112(8):850-851
An 87-year-old man was found to have a lymphoma in the deep soft tissue of the right shoulder with concomitant central nervous system involvement. There was no evidence of cutaneous, peripheral lymph node, mediastinal, abdominal, or bone marrow involvement. Light microscopic, ultrastructural, and immunohistochemical evaluation characterized the neoplasm as a peripheral T-cell lymphoma. Lymphomas presenting in soft tissue are rare, and the few well-documented cases in the literature are of B-cell origin. We report a T-cell lymphoma presenting in the soft tissue of the extremity, and delineate its clinicopathologic features. 相似文献
20.
Immunological clearance of 75Se-labelled Trypanosoma brucei in mice. III. Studies in animals with acute infections. 总被引:1,自引:0,他引:1 下载免费PDF全文
Using trypanosomes labelled with [75Se]-methionine a series of experiments was conducted to investigate antibody production in mice with acute fulminating T. brucei infections. As measured by the hepatic uptake of radiolabelled parasites, we were unable to demonstrate any evidence of antibody-mediated uptake by the liver in such mice. It was concluded that this was not due to impaired macrophage function but was caused by the inability of antibody production to cope with the massive parasitaemias produced by rapidly-replicating infections so that effective opsonization of the parasites did not occur. In contrast, a train of trypanosome which causes a more chronic infection, although initially having a similar replication, although initially having a similar replication rate, subsequently switched t a slower one and thereby allowed antibody to reach levels which permitted effective opsonization. There was no evidence that the parasite caused any significant suppression of antibody responses in these acute infections since inoculation with trypanosomes of one stock at the same time as vaccination with irradiated organisms of a second stock did not prevent the development of antibody to the latter, as measured by the hepatic uptake of radiolabelled parasites. 相似文献