全文获取类型
收费全文 | 1864篇 |
免费 | 111篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 102篇 |
妇产科学 | 39篇 |
基础医学 | 252篇 |
口腔科学 | 20篇 |
临床医学 | 142篇 |
内科学 | 320篇 |
皮肤病学 | 37篇 |
神经病学 | 136篇 |
特种医学 | 43篇 |
外科学 | 273篇 |
综合类 | 31篇 |
预防医学 | 97篇 |
眼科学 | 71篇 |
药学 | 236篇 |
中国医学 | 19篇 |
肿瘤学 | 146篇 |
出版年
2023年 | 10篇 |
2022年 | 26篇 |
2021年 | 60篇 |
2020年 | 26篇 |
2019年 | 30篇 |
2018年 | 43篇 |
2017年 | 26篇 |
2016年 | 37篇 |
2015年 | 50篇 |
2014年 | 49篇 |
2013年 | 106篇 |
2012年 | 156篇 |
2011年 | 135篇 |
2010年 | 103篇 |
2009年 | 76篇 |
2008年 | 141篇 |
2007年 | 121篇 |
2006年 | 110篇 |
2005年 | 116篇 |
2004年 | 96篇 |
2003年 | 96篇 |
2002年 | 82篇 |
2001年 | 19篇 |
2000年 | 22篇 |
1999年 | 22篇 |
1998年 | 16篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1989年 | 14篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1971年 | 4篇 |
1968年 | 4篇 |
排序方式: 共有1981条查询结果,搜索用时 390 毫秒
11.
RhoC is dispensable for embryogenesis and tumor initiation but essential for metastasis 总被引:14,自引:0,他引:14
Hakem A Sanchez-Sweatman O You-Ten A Duncan G Wakeham A Khokha R Mak TW 《Genes & development》2005,19(17):1974-1979
The Rho proteins are Ras-related guanosine triphosphatases (GTPases) that function in cytoskeletal reorganization, cell migration, and stress fiber and focal adhesion formation. Overexpression of RhoC enhances the ability of melanoma cells to exit the blood and colonize the lungs. However, in vivo confirmation of RhoC's role in metastasis has awaited a RhoC-deficient mouse model. Here we report the generation of RhoC-deficient mice and show that RhoC is dispensable for embryonic and post-natal development. We demonstrate that loss of RhoC does not affect tumor development but decreases tumor cell motility and metastatic cell survival leading to a drastic inhibition of metastasis. 相似文献
12.
Amara RR Ibegbu C Villinger F Montefiori DC Sharma S Nigam P Xu Y McClure HM Robinson HL 《Virology》2005,343(2):246-255
Here, we study immune responses in four DNA/MVA-vaccinated macaques following an SHIV-89.6P challenge and a subsequent CD8 cell depletion. Both post-challenge and post-depletion peaks of viremia contracted with the expansion, or re-emergence, of CD8 T cells. Post-depletion, CD8 cells expanded in the presence of higher levels of neutralizing Ab and CD4 help than post-challenge and had superior maturational characteristics as measured by expression of the anti-apoptotic protein Bcl-2, the IL-7 receptor CD127 and co-production of IFN-gamma and IL-2. Pre-challenge and pre-depletion titers of neutralizing Ab correlated inversely with peaks of viremia and directly with peaks for anti-viral CD4 cells. Thus, our results reveal CD8 cells playing a central role, and neutralizing Ab, a supporting role in SHIV-89.6P control. They also suggest a dynamic relationship between neutralizing Ab, antigen load and anti-viral CD4 cells in the maturation of high-quality anti-viral CD8 T cells. 相似文献
13.
Esophageal ulceration triggers expression of hypoxia-inducible factor-1 alpha and activates vascular endothelial growth factor gene: implications for angiogenesis and ulcer healing 下载免费PDF全文
Baatar D Jones MK Tsugawa K Pai R Moon WS Koh GY Kim I Kitano S Tarnawski AS 《The American journal of pathology》2002,161(4):1449-1457
14.
15.
The isolation, primary culture and attachment of liver cells to the substratum from a tropical catfish (Heteropneustes fossilis) using ethylenediaminetetraacetic acid (EDTA) as isolating agent of liver cells and skin extract (SE) from fish as attachment substrate for the primary culture of liver cells has been standardised. A suitable temperature for such cultures has also been determined. Attachment efficiency of the liver cells in culture and their intracellular lactate dehydrogenase (LDH) activity have been taken as parameters for characterization of the primary culture. Disaggregation of liver cells with EDTA is very potent to isolate substantial rumber of cells from the liver of H. fossilis. An ideal concentration of EDTA for liver cell isolation has been standardized. Matrix prepared from carp and catfish skin at different pH (2.0, 4.0, 6.0 and 8.0) were also evaluated for liver cell culture by considering the attachment efficiency of the cells over the substratum as well as retention of intracellular LDH enzyme after 48 hours of seeding. Matrix of carp skin was compared with that of catfish as suitable substrate for primary culture of fish liver cells. It has been found that the SE prepared at pH 4.0, both from carp and catfish skin, performed better than those at other pHs. At the same time, the matrix of carp skin was found to be better than that of catfish skin. Cultures were incubated separately at 17 and 23 °C in air atmosphere. Incubation temperature at 23 °C was found to be more suitable than that at 17 °C. The percent of detached/unattached cells showed only marginal variation between two temperatures but LDH-activity recorded drastic reduction (between 50 to 75%) depending upon the pH of the matrix during preparation. Our finding establishes despensibility of enzyme (collagenase/trypsin) for cell isolation in catfish. Our studies also exhibit that carp skin extract performs better than catfish skin extract in terms of attachment efficiency as well as intracellular LDH activity. This study indicates that no species/generic barrier exists in matrix between catfish and carp. 相似文献
16.
Nitric oxide is involved in the neutrophil and macrophage killing of the protozoan parasite Entamoeba histolytica. In the present study, we found that cysteine proteinases, significant contributors to amebic virulence and alcohol dehydrogenase 2, an enzyme absolutely required for the survival of the parasite, are both significantly inhibited by S-nitroso-glutathione, a physiological nitric oxide donor, within the concentration range 0.5-2.0 m M. 相似文献
17.
Comparison of real-time PCR protocols for differential laboratory diagnosis of amebiasis 总被引:1,自引:0,他引:1 下载免费PDF全文
Qvarnstrom Y James C Xayavong M Holloway BP Visvesvara GS Sriram R da Silva AJ 《Journal of clinical microbiology》2005,43(11):5491-5497
Specific identification of Entamoeba spp. in clinical specimens is an important confirmatory diagnostic step in the management of patients who may be infected with Entamoeba histolytica, the species that causes clinical amebiasis. Distinct real-time PCR protocols have recently been published for identification of E. histolytica and differentiation from the morphologically identical nonpathogenic Entamoeba dispar. In this study, we compared three E. histolytica real-time PCR techniques published by December 2004. The limits of detection and efficiency of each real-time PCR assay were determined using DNA extracted from stool samples spiked with serially diluted cultured E. histolytica trophozoites. The ability of each assay to correctly distinguish E. histolytica from E. dispar was evaluated with DNA extracted from patients' stools and liver aspirates submitted for confirmatory diagnosis. Real-time PCR allowed quantitative analysis of the spiked stool samples, but major differences in detection limits and assay performance were observed among the evaluated tests. These results illustrate the usefulness of comparative evaluations of diagnostic assays. 相似文献
18.
Severe hypoxia decreases oxygen uptake relative to intensity during submaximal graded exercise 总被引:1,自引:0,他引:1
J. Ibañez R. Rama M. Riera M. T. Prats L. Palacios 《European journal of applied physiology》1993,67(1):7-13
Summary The effect of severe acute hypoxia (fractional concentration of inspired oxygen equalled 0.104) was studied in nine male subjects performing an incremental exercise test. For power outputs over 125 W, all the subjects in a state of hypoxia showed a decrease in oxygen consumption (
O2) relative to exercise intensity compared with normoxia (P < 0.05). This would suggest an increased anaerobic metabolism as an energy source during hypoxic exercise. During submaximal exercise, for a given
O2, higher blood lactate concentrations were found in hypoxia than in normoxia (P < 0.05). In consequence, the onset of blood lactate accumulation (OBLA) was shifted to a lower
O2 (
O2 1.77 l·min–1 in hypoxia vs 3.10 l·min–1 in normoxia). Lactate concentration increases relative to minute ventilation (
E) responses were significantly higher during hypoxia than in normoxia (P < 0.05). At OBLA,
E during hypoxia was 25% lower than in the normoxic test. This study would suggest that in hypoxia subjects are able to use an increased anaerobic metabolism to maintain exercise performance. 相似文献
19.
Yosi Wibowo Ph.D Adji P. Setiadi Dr. Steven V. Halim M.Pharm. Rama D. Saputra B.Pharm. Rizka Oktavia B. Pharm. Rizky Irianti B. Pharm. Putri I. Lestari B. Pharm Cecilia R. Puspitasari B.Pharm. Bruce Sunderland Ph.D. 《Health & social care in the community》2021,29(2):554-563
In 2015, the Indonesian Government initiated ‘Smart Use of Medications Movement’ (‘GeMa CerMat’) which included cadre training to promote responsible self-medication. Evaluation of a pilot training conducted across Indonesia suggested the need to improve those training modules. This study aimed to assess cadre’ knowledge gained following training with newly developed general or specific training modules. Five types of modules were developed and used to train cadres at five Community Health Centres (CHCs) in Surabaya, Indonesia: 1) Sidosermo CHC (general-drugs module), 2) Tenggilis CHC (common cold drugs module), 3) Gunung Anyar CHC (analgesic drugs module), 4) Kalirungkut CHC (anti-diarrhoeal drugs module), and 5) Jagir CHC (indigestion drugs module). Cadres’ knowledge improvements were evaluated using pre-/post-test scores and the difference scores depending on the module being tested. Multifactorial ANOVA explored the effects of the type of module on difference scores. A total of 279 cadres across five CHCs were involved in the training, giving response rates from 65% to 93%. There was an increase in the post-test scores after the training with all modules. However, significant differences were reported only for the specific-drugs module groups (all p < .001). Furthermore, the general module group had the lowest difference score (1.12; 95% CI [−0.45, 2.92]) while the common cold module group had the highest gain (5.02; 95% CI [1.95, 5.17]). Multifactorial ANOVA revealed that there was a significant main effect of the type of modules on difference scores [F (4, 263) = 8.37, p <.001]. In conclusion, this preliminary study indicated that the development of modules for specific minor illnesses could be beneficial in facilitating effective community-based training to promote responsible self-medication in Indonesia. The priority for therapeutic areas chosen for the module should be based on the local needs. Further research is required to confirm the findings in broader community members. 相似文献
20.
Rotwein S Boulmetis M Boben PJ Fingold HI Hadley JP Rama KL Van Hoven D 《Health care financing review》1995,16(3):105-120
Health care reform is a continuously evolving process. The States and the Federal Government have struggled with policy issues to combat escalating Medicaid expenditures while ensuring access and quality of care to an ever-expanding population. In the absence of national health care reform, States are increasingly relying on Federal waivers to develop innovative approaches to address a myriad of issues associated with the present health care delivery system. This article provides a summary of State health care reform efforts that have been initiated under Federal waiver authority. 相似文献