全文获取类型
收费全文 | 1562篇 |
免费 | 94篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 27篇 |
妇产科学 | 78篇 |
基础医学 | 160篇 |
口腔科学 | 64篇 |
临床医学 | 103篇 |
内科学 | 438篇 |
皮肤病学 | 19篇 |
神经病学 | 249篇 |
特种医学 | 30篇 |
外科学 | 221篇 |
综合类 | 5篇 |
一般理论 | 3篇 |
预防医学 | 89篇 |
眼科学 | 42篇 |
药学 | 47篇 |
中国医学 | 1篇 |
肿瘤学 | 63篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 20篇 |
2020年 | 23篇 |
2019年 | 22篇 |
2018年 | 29篇 |
2017年 | 33篇 |
2016年 | 31篇 |
2015年 | 26篇 |
2014年 | 46篇 |
2013年 | 52篇 |
2012年 | 81篇 |
2011年 | 79篇 |
2010年 | 52篇 |
2009年 | 60篇 |
2008年 | 78篇 |
2007年 | 117篇 |
2006年 | 96篇 |
2005年 | 103篇 |
2004年 | 90篇 |
2003年 | 103篇 |
2002年 | 125篇 |
2001年 | 19篇 |
2000年 | 14篇 |
1999年 | 18篇 |
1998年 | 25篇 |
1997年 | 24篇 |
1996年 | 22篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 21篇 |
1991年 | 16篇 |
1990年 | 16篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 17篇 |
1982年 | 8篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 5篇 |
排序方式: 共有1660条查询结果,搜索用时 31 毫秒
31.
32.
33.
The use of the hydrodynamic HBV animal model to study HBV biology and anti-viral therapy. 总被引:1,自引:0,他引:1
Mali Ketzinel-Gilad Arie Zauberman Ofer Nussbaum Yariv Shoshany Ofer Ben-Moshe Orit Pappo Yaakov Felig Ehud Ilan Hanna Wald Shlomo Dagan Eithan Galun 《Hepatology research》2006,34(4):228-237
A simple reproducible and versatile small animal model for hepatitis B virus (HBV) infection is still unavailable. We have generated a simple transient liver-targeted transgenic mouse. Hydrodynamics tail vein injection of a head-to-tail dimer of adw HBV genome (pHBVadwHTD) into immunocompetent mice generated HBsAg and HBeAg expression in both serum and hepatocytes, followed by seroconversion. The injection of pHBVadwHTD into SCID mice generated prolonged HBsAg and HBeAg antigenemia and HBV viremia. Our results demonstrate that hydrodynamic injection of naked DNA could support the generation of HBV particles. We used this model for the assessment of anti-viral agents. Administration of our human monoclonal antibodies, HBV-Ab17(XTL) and HBV-Ab19(XTL), as well as Lamivudine (3TC) treatment suppressed HBV viremia. The model presented herein supports long and stable expression of HBV and will enable determination of various biological questions related to HBV life cycle, mutants and could enhance the development of anti-viral reagents. 相似文献
34.
Murray RD Kim K Ren SG Lewis I Weckbecker G Bruns C Melmed S 《The Journal of clinical endocrinology and metabolism》2004,89(6):3027-3032
Currently available somatostatin analogs predominantly bind to the somatostatin receptor subtype (SSTR)2 subtype, and control GH and IGF-I secretion in approximately 65% of patients with acromegaly, their efficacy relating to receptor density and subtype expression. SOM230 is a somatostatin ligand with high affinity to four SSTR subtypes. In primary cultures of rat pituicytes, SOM230 dose-dependently inhibited GH release (P = 0.002) with an IC50 of 1.2 nM. Ten nanomoles SOM230 inhibited GH and TSH release by 40 +/- 7% (P < 0.001) and 47 +/- 21% (P = 0.09), respectively. No effect of SOM230 was observed on prolactin (PRL) or LH release. In cultures of human fetal pituitary cells, SOM230 inhibited GH secretion by 42 +/- 9% (P = 0.002) but had no effect on TSH release. SOM230 inhibited GH release from GH-secreting adenoma cultures by 34 +/- 8% (P = 0.002), PRL by 35 +/- 4% from PRL-secreting adenomas (P = 0.01), and alpha-subunit secretion from nonfunctioning pituitary adenomas by 46 +/- 18% (P = 0.34). In contrast, octreotide inhibited GH, PRL, and alpha-subunit from the respective adenoma by 18 +/- 12 (P = 0.39), 22 +/- 4 (P = 0.04), and 20 +/- 10% (P = 0.34). In all culture systems, no significant difference in the inhibitory action of SOM230, octreotide, and somatostatin 14 on hormone release was observed. SOM230, similar to somatostatin, has high-affinity binding to SSTR1, 2, 3, and 5 and, in keeping with this, has an equivalent inhibitory effect on pituitary hormone secretion. As a consequence of its broader binding profile, SOM230 is likely to find clinical utility in treating tumors resistant to SSTR-2-preferential analogs. 相似文献
35.
Are triglyceride-rich lipoproteins associated with aortic valve sclerosis? A preliminary report 总被引:2,自引:0,他引:2
Background: Evidence linking cardiovascular risk factors to aortic valve sclerosis (AVS) has led to the assumption that the latter is an atherosclerosis-like process. However, triglyceride (TG)-rich lipoproteins, an important risk factor for atherosclerosis, have been rarely investigated in connection with AVS. Methods: A cross-sectional study of 246 healthy individuals (mean age 59±6 years, 77% men) was conducted. Subjects underwent an echocardiographic assessment and extensive blood lipid measurements, including evaluation of TG-related indices, such as serum apolipoprotein (apo) CII and CIII levels, apo CIII levels in VLDL+LDL particles, and apo CIII ratio (CIII level in HDL/CIII level in VLDL+LDL). Results: Twenty-three patients (9.3%) were diagnosed as having AVS. On average, these patients were 5 years older and had higher levels of serum cholesterol, LDL-C and LP(a), compared with non-AVS subjects. In addition, the AVS patients exhibited higher concentrations of serum apo CII, serum apo CIII and apo CIII in VLDL+LDL, and a lower apo CIII ratio. Adjusting for age and gender, a 1 S.D. increment in apo CIII in VLDL+LDL was associated with odds ratio (OR) of 1.76 (95% CI: 1.17–2.65) for AVS. Further adjustment for atherosclerotic risk factors did not alter the association appreciably (OR=1.65, 95% CI: 1.06–2.58). Conclusion: TG-rich lipoproteins may be involved in the early development of AVS. Confirmation in prospective studies is required. 相似文献
36.
Aspirin withdrawal in patients treated with ticagrelor presenting with non‐ST elevation myocardial infarction
下载免费PDF全文
![点击此处可从《Journal of thrombosis and haemostasis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
R. Beigel I. Mazin E. Koifman M. Shechter H. Pres N. Shlomo N. Rosenberg E. Asher S. Matetzky 《Journal of thrombosis and haemostasis》2018,16(4):663-669
Essentials
- Strong P2Y12 blockade may cause platelet inhibition that is only minimally enhanced by aspirin.
- We evaluated aspirin withdrawal on platelet reactivity in ticagrelor treated patients.
- Aspirin withdrawal resulted in increased platelet reactivity to arachidonic acid.
- Aspirin withdrawal caused little difference in adenosine diphosphate‐induced platelet aggregation.
Summary
Background
Recent studies have shown that the thromboxane A2‐dependent pathway is dependent on the ADP–P2Y12 pathway, and that strong P2Y12 receptor blockade alone causes inhibition of platelet aggregation that is minimally enhanced by aspirin. Data from the PLATO trial suggested that, among ticagrelor‐treated patients, high‐dose versus low‐dose (< 100 mg day?1) aspirin is associated with an increased risk fof ischemic events.Objectives
To evaluate the impact of aspirin withdrawal on platelet reactivity in acute coronary syndrome (ACS) patients treated with a potent P2Y12 blocker.Patients/Methods
This was a current prospective, randomized, placebo‐controlled, double‐blind, cross‐over study. The study population comprised 22 consecutive ACS patients who underwent percutaneous coronary intervention and were treated with aspirin (100 mg day?1) and ticagrelor. Thirty days post‐ACS, open‐label aspirin was stopped, and patients were randomized to either blinded aspirin or placebo for 2 weeks, with each patient crossing over to the other arm for an additional 2 weeks. Platelet reactivity to arachidonic acid and ADP determined with light‐transmission aggregometry (LTA) and VerifyNow was evaluated at baseline, and 2 weeks and 4 weeks later.Results
Aspirin withdrawal resulted in an increase in arachidonic‐acid induced platelet reactivity as determined with both LTA (77.0% ± 11.3% versus 20.8% ± 4.4%) and VerifyNow (607.7 ± 10.6 aspirin reaction units [ARU] versus 408.5 ± 14.4 ARU). Platelet response to ADP, as determined with both LTA and VerifyNow, did not differ with either aspirin or placebo (32.9% ± 2.6% versus 35.8% ± 3.6%, and 33.5 ± 6.4 P2Y12 reaction units (PRU) versus 29.6 ± 5.7 PRU, respectively).Conclusions
Aspirin withdrawal early post‐ACS results in increased platelet reactivity in response to arachidonic acid, despite concomitant treatment with the potent P2Y12 blocker ticagrelor.37.
Expansion Conditions for Early Hepatic Progenitor Cells from Embryonal and Neonatal Rat Livers 总被引:6,自引:0,他引:6
Long-term primary cultures were established fromfetal or neonatal livers by using cell suspensionsdepleted of red blood cells and by culturing the cellsin hormonally defined medium containing dimethyl sulfoxide. Two distinct populations of hepaticprogenitor cells were evident in the cultures, based onmorphology, proliferative ability, and liver-specificgene expression. Most colonies consisted of immature hepatic progenitors: small, blastlike cells,weakly expressing alpha-fetoprotein, albumin, and-glutamyltranspeptidase, and showing evidence ofproliferation as measured by bromodeoxyuridineincorporation. At the perimeter of these colonies of immaturecells and forming some colonies by themselves were moremature hepatic progenitor cells: larger cells, withincreased cytoplasmic to nuclear ratios, little proliferation, and strongly expressing albumin,alpha-fetoprotein, and -glutamyltranspeptidase.The latter two proteins were localized to the bilecanalicular membranes of these cells. Glycogen deposits were present in the mature cells from day 14embryos after eight days of culture. Thus, DMSOtreatment of hepatic parenchymal progenitors provides anovel system for studies of liver development. 相似文献
38.
Maharshak N Arbel Y Gal-Oz A Rogowski O Shapira I Berliner S Vered Y Canaani J Dotan I 《Journal of digestive diseases》2008,9(3):140-143
OBJECTIVE: The recently introduced Bayer wide‐range C‐reactive protein (wr‐CRP) assay might be relevant for the real‐time low‐cost and online determination of inflammatory bowel disease (IBD) activity. Our aim was to examine whether wr‐CRP can substitute for the Dade Behring high sensitivity C‐reactive protein (hs‐CRP) assay in IBD patients. METHODS: A total of 71 patients with IBD, of whom 48 had Crohn's disease CD and 23 had ulcerative colitis (UC) with various intensities of disease activity participated in the study. The CRP of patients who were under treatment at the Department of Gastroenterology and Liver Diseases were measured using both wr‐CRP and the hs‐CRP. RESULTS: A significant (r = 0.995; P < 0.001) correlation was noted between the hs‐CRP and wr‐CRP measurements for the whole sample as well as for the two diseases, CD (r = 0.994; P < 0.001) and UC (r = 0.997; P < 0.001), which were analyzed separately. CONCLUSION: The Bayer wr‐CRP assay might be a useful low‐cost and real‐time inflammation‐sensitive biomarker in patients with IBD. 相似文献
39.
Can F. Koyuncu Cheng Lu Kaustav Bera Zelin Zhang Jun Xu Paula Toro German Corredor Deborah Chute Pingfu Fu Wade L. Thorstad Farhoud Faraji Justin A. Bishop Mitra Mehrad Patricia D. Castro Andrew G. Sikora Lester D.R. Thompson R.D. Chernock Krystle A. Lang Kuhs Jingqin Luo Vlad Sandulache David J. Adelstein Shlomo Koyfman James S. Lewis Jr. Anant Madabhushi 《The Journal of clinical investigation》2021,131(8)
BACKGROUNDPatients with p16+ oropharyngeal squamous cell carcinoma (OPSCC) are potentially cured with definitive treatment. However, there are currently no reliable biomarkers of treatment failure for p16+ OPSCC. Pathologist-based visual assessment of tumor cell multinucleation (MN) has been shown to be independently prognostic of disease-free survival (DFS) in p16+ OPSCC. However, its quantification is time intensive, subjective, and at risk of interobserver variability.METHODSWe present a deep-learning–based metric, the multinucleation index (MuNI), for prognostication in p16+ OPSCC. This approach quantifies tumor MN from digitally scanned H&E-stained slides. Representative H&E-stained whole-slide images from 1094 patients with previously untreated p16+ OPSCC were acquired from 6 institutions for optimization and validation of the MuNI.RESULTSThe MuNI was prognostic for DFS, overall survival (OS), or distant metastasis–free survival (DMFS) in p16+ OPSCC, with HRs of 1.78 (95% CI: 1.37–2.30), 1.94 (1.44–2.60), and 1.88 (1.43–2.47), respectively, independent of age, smoking status, treatment type, or tumor and lymph node (T/N) categories in multivariable analyses. The MuNI was also prognostic for DFS, OS, and DMFS in patients with stage I and stage III OPSCC, separately.CONCLUSIONMuNI holds promise as a low-cost, tissue-nondestructive, H&E stain–based digital biomarker test for counseling, treatment, and surveillance of patients with p16+ OPSCC. These data support further confirmation of the MuNI in prospective trials.FUNDINGNational Cancer Institute (NCI), NIH; National Institute for Biomedical Imaging and Bioengineering, NIH; National Center for Research Resources, NIH; VA Merit Review Award from the US Department of VA Biomedical Laboratory Research and Development Service; US Department of Defense (DOD) Breast Cancer Research Program Breakthrough Level 1 Award; DOD Prostate Cancer Idea Development Award; DOD Lung Cancer Investigator-Initiated Translational Research Award; DOD Peer-Reviewed Cancer Research Program; Ohio Third Frontier Technology Validation Fund; Wallace H. Coulter Foundation Program in the Department of Biomedical Engineering; Clinical and Translational Science Award (CTSA) program, Case Western Reserve University; NCI Cancer Center Support Grant, NIH; Career Development Award from the US Department of VA Clinical Sciences Research and Development Program; Dan L. Duncan Comprehensive Cancer Center Support Grant, NIH; and Computational Genomic Epidemiology of Cancer Program, Case Comprehensive Cancer Center. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH, the US Department of VA, the DOD, or the US Government. 相似文献
40.
Shlomo Kotev-Emeth Sandu Pitaru Sara Pri-Chen Naphtali Savion 《Connective tissue research》2013,54(4):606-612
Rat stromal bone-marrow cells cultured in the presence of dexamethasone, ascorbic acid, g -glycerophosphate, and fibroblast growth factor-2 (FGF-2) express the osteogenic phenotype (Pitaru et al., J. Bone Miner. Res . 8:919-929, 1993). The purpose of this study was to establish a long-term homogeneous culture expressing the osteogenic phenotype. The cultures were routinely passaged every 5 days in the absence or presence of either or both dexamethasone and FGF-2, and the cumulative doubling number and the expression of the osteogenic phenotype were determined. Cultures treated with dexamethasone (10 m 7 M) ceased proliferation and only upon addition of FGF-2 (3 ng/ml) was a spontaneous immortalization achieved, as expressed by sustained proliferation for about 1 year, with a doubling time of 22 h and more than 300 doublings in 72 passages. Both FGF-2 and dexamethasone are required and act synergistically to maintain cell propagation, alkaline phosphatase expression, and osteocalcin secretion; however, protein content was FGF-2 dependent and the mineralization was dexamethasone dependent. Repetitive single-cell cloning tested the homogeneity and stability of the cells expressing the osteogenic phenotype in these long-term cultures. It was shown that 25% to 50% of subclones derived from clones with an osteogenic phenotype do not further express the osteogenic phenotype. In conclusion, we have established a spontaneously immortalized dexamethasone- and FGF-2-dependent rat stromal bone-marrow-derived long-term culture expressing the osteogenic phenotype. The cultures tend to lose the osteogenic phenotype, and dexamethasone supports the long-term preservation of the osteogenic phenotype. 相似文献