全文获取类型
收费全文 | 3215篇 |
免费 | 228篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 223篇 |
妇产科学 | 65篇 |
基础医学 | 446篇 |
口腔科学 | 78篇 |
临床医学 | 265篇 |
内科学 | 848篇 |
皮肤病学 | 81篇 |
神经病学 | 111篇 |
特种医学 | 379篇 |
外科学 | 322篇 |
综合类 | 29篇 |
一般理论 | 1篇 |
预防医学 | 144篇 |
眼科学 | 51篇 |
药学 | 202篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 218篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 59篇 |
2020年 | 30篇 |
2019年 | 66篇 |
2018年 | 74篇 |
2017年 | 55篇 |
2016年 | 57篇 |
2015年 | 68篇 |
2014年 | 64篇 |
2013年 | 114篇 |
2012年 | 109篇 |
2011年 | 109篇 |
2010年 | 100篇 |
2009年 | 114篇 |
2008年 | 91篇 |
2007年 | 136篇 |
2006年 | 112篇 |
2005年 | 102篇 |
2004年 | 97篇 |
2003年 | 100篇 |
2002年 | 90篇 |
2001年 | 91篇 |
2000年 | 120篇 |
1999年 | 97篇 |
1998年 | 117篇 |
1997年 | 137篇 |
1996年 | 132篇 |
1995年 | 88篇 |
1994年 | 99篇 |
1993年 | 108篇 |
1992年 | 59篇 |
1991年 | 44篇 |
1990年 | 48篇 |
1989年 | 59篇 |
1988年 | 61篇 |
1987年 | 51篇 |
1986年 | 59篇 |
1985年 | 53篇 |
1984年 | 34篇 |
1983年 | 24篇 |
1982年 | 25篇 |
1981年 | 37篇 |
1980年 | 23篇 |
1979年 | 22篇 |
1978年 | 14篇 |
1977年 | 27篇 |
1976年 | 23篇 |
1975年 | 12篇 |
1973年 | 12篇 |
排序方式: 共有3471条查询结果,搜索用时 9 毫秒
41.
Tomás JM Camprubí S Merino S Parés R Llauradó X Julve J 《International journal of antimicrobial agents》1993,3(1):61-64
The inhibitory activity of different components from Candida albicans membrane protoplasts against clotrimazole and eberconazole was studied. The phospholipid fraction had the most inhibitory activity and the antimycotic activity of eberconazole was more affected than that of clotrimazole. 相似文献
42.
43.
CT evaluation of gastric wall pathology 总被引:4,自引:0,他引:4
Merino S Saiz A Moreno MJ Parlorio E Pedrosa I Yus M 《The British journal of radiology》1999,72(863):1124-1131
The purpose of this study is to show the CT features of common and infrequent pathological lesions of the gastric wall. Although CT features are not often specific, familiarity with the most frequent pathological gastric findings on CT can assist in differential diagnosis. 相似文献
44.
Pathways to care for alcohol use disorders 总被引:1,自引:0,他引:1
45.
Infarction of breast fibroadenomas is very rare and is frequently associated with physiologic changes, such as pregnancy and lactation. We report a case of an infarcted fibroadenoma following fine-needle aspiration. The patient presented with an asymptomatic breast mass, which was clinically difficult to evaluate. Excisional biopsy was performed 7 days after a nondiagnostic fine-needle aspiration of the mass. Microscopically, the nodule showed features of a classic fibroadenoma of the intracanalicular type with myxoid or mucinous stromal changes, as well as extensive areas of acute infarction. This report provides another example of the changes that may be observed in biopsy specimens obtained after fine-needle aspiration of the breast. 相似文献
46.
Dr. Gerard M. Doherty MD H. Richard Alexander MD Maria J. Merino MD David J. Venzon PhD Jeffrey A. Norton MD 《Annals of surgical oncology》1996,3(2):198-203
Background: The anticancer role of tumor necrosis factor-alpha (TNF-) has been limited by toxicity. These experiments evaluate blocking endogenous interferon-gamma (IFN-) activity to abrogate TNF- toxicity.
Methods: C57Bl/6 mice bearing MCA 105 tumor were treated with TNF- and anti-IFN- antibody (Ab) to evaluate the effect on the acute lethality of TNF- and their efficacy as evaluated by tumor growth rate, tumor histology, and survival.
Results: Anti-IFN- Ab decreased TNF- lethality. Anti-IFN- Ab alone increased tumor growth significantly more than did nonimmune IgG (p2<0.0001). Tumor-bearing mice that received nonimmune IgG and TNF- had slower tumor growth (p2<0.02) and a trend toward improved survival (p=0.07) compared with saline-treated controls. Anti-IFN- Ab abrogated the antitumor effect of TNF-, prevented acute tumor necrosis histologically, and resulted in tumor growth rate and host survival similar to that of controls. The findings in mice that received anti-IFN- Ab and high-dose TNF- were comparable with those in mice that received a lower, equitoxic dose of TNF- alone.
Conclusions: Blocking endogenous IFN- accelerates tumor growth in this model and partially abrogates the toxic and antitumor activity of exogenous TNF- equally. This suggests that blocking endogenous IFN- activity is not a useful strategy for limiting TNF- treatment toxicity.Presented in part at the 45th Annual Cancer Symposium of The Society of Surgical Oncology, New York, New York, March 15–18, 1992. 相似文献
47.
Pleomorphic lobular carcinoma: morphology, immunohistochemistry, and molecular analysis 总被引:6,自引:0,他引:6
Middleton LP Palacios DM Bryant BR Krebs P Otis CN Merino MJ 《The American journal of surgical pathology》2000,24(12):1650-1656
Infiltrating pleomorphic lobular carcinoma (PLC) is an aggressive variant of infiltrating lobular carcinoma. Recently, in situ changes identical to PLC (PLCIS) have been described. The role of prognostic markers and their correlation with therapeutics, clinical outcome, and genetic changes is not well established in PLC. The authors examined 38 cases of this entity to understand better this tumor's biology. Immunohistochemical (IHC) analysis was performed in 21 specimens for estrogen and progesterone steroid receptors, p53, Her 2 (p185), and GCDFP-15. Genomic deoxyribonucleic acid was obtained from microdissected tumor as well as normal control cells, and loss of heterozygosity was investigated at the ESR (16q24), p53 (TP53 17p), Her 2 (17q 11-12), and BRCA 1 (17q12-25) loci. In this series, the average patient age was 57.5 years (age range, 24-92 years). Twenty-seven women were postmenopausal. Tumor size ranged from 1.2 to 25 cm. Six patients were a pathologic stage I; 19, stage II; 12, stage III; and one, stage IV. Histologically, multifocal nodular aggregates of discohesive pleomorphic tumor cells were seen interspersed in dense and fibrotic breast parenchyma. Twenty-nine percent of the specimens demonstrated associated signet ring cells. The remainder had dishesive, globoid, plasmacytoid cells with high-grade nuclear features. PLCIS was identified in 17 of 38 patients (45%), and lobular carcinoma in situ (LCIS) was noted in 8 patients (21%). IHC analysis showed estrogen immunoreactivity in 81%, progesterone in 67%, GCDFP-15 in 71%, and Her 2 in 81% (2+ to 3+ membranous staining) of specimens. Antibodies to p53 stained the tumor cell nuclei in 48% of the tumors. Loss of heterozygosity was identified in 52% of the specimens at the p53 locus, 18% at the ESR locus, 19% to 24% at the Her 2 loci, and 27% to 32% at the BRCA 1 locus. Follow-up was available in 19 patients and ranged from 12 months to 15 years (mean, 73 months). Seven patients had no evidence of disease at last examination (range, 1-15 years), three patients were alive with disease (range, 2-14 years), and nine patients were dead of disease (range, 2 months-9 years). Six patients had subsequent diagnoses of tumor in the contralateral breast. Analysis shows that PLC tends to appear in older postmenopausal women who present with locally advanced disease. PLCIS was found to be associated with PLC 45% of the time. The aggressive clinical course of patients with PLC is supported by tumor immunoreactivity with unfavorable markers Her 2 and p53. Overexpression of Her 2 in PLC may be therapeutically relevant, enabling the use of novel chemotherapeutic drugs like Herceptin. Interestingly, tumors that were Her 2 immunoreactive also maintained estrogen hormone immunoreactivity. 相似文献
48.
MJ Stevens PD Stricker J Saalfeld PC Brenner R Kooner GFA O'Neill PJ Duval RS Jagavkar P Cross J Martland 《Journal of Medical Imaging and Radiation Oncology》2003,47(2):152-160
Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability. 相似文献
49.
50.
Abril N; Luque-Romero FL; Prieto-Alamo MJ; Rafferty JA; Margison GP; Pueyo C 《Carcinogenesis》1997,18(10):1883-1888
Here we confirm and extend our previous studies demonstrating that the
mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is
markedly enhanced (not prevented) in bacteria expressing the O6-
alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli
ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt
ATase sensitizes the bacteria to the lethal effects of these carcinogens,
suggesting that one or more of the potentially mutagenic lesions induced by
DBE and DBM in the presence of Ogt has additional lethal capacity. We
further demonstrate that the sensitization to both lethality and
mutagenesis by DBE and DBM is a property shared by other DNA
alkyltransferases. This objective was accomplished by quantifying the
induction of mutations and lethal events in ogt- ada- E. coli expressing an
exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian
recombinant ATases enhanced the lethal and mutagenic actions of DBE and
suppressed the lack of sensitivity of the vector- transformed bacteria to
DBM. In most cases the order of effectiveness of the ATases ranked: murine
> human > Ogt > rat. Further comparisons included the full-length
Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the
O6-methylguanine binding domain of the protein. The full-length Ada ATase
was effective in enhancing the lethality but not the mutagenicity induced
by DBE and DBM. The T-ada ATase provided less sensitization than Ada to
lethality by DBE, but of the three bacterial ATases T-ada yielded the
highest sensitization to mutagenesis by this compound. T-ada and Ada ATases
were in general less effective than the mammalian versions, with the
exception of the rat recombinant ATase. The effectiveness of the different
mammalian and bacterial ATases in promoting the deleterious actions of
dibromoalkanes was compared with the effectiveness of these proteins in
suppressing the lethal and mutagenic effects induced by
N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and
mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase,
since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt-
ada- cells showed no effect, in spite of the reported potential of
bioactive dihaloethane- derived species to alkylate Trx.
相似文献