全文获取类型
收费全文 | 34037篇 |
免费 | 1755篇 |
国内免费 | 196篇 |
专业分类
耳鼻咽喉 | 353篇 |
儿科学 | 725篇 |
妇产科学 | 749篇 |
基础医学 | 4339篇 |
口腔科学 | 1209篇 |
临床医学 | 2581篇 |
内科学 | 8986篇 |
皮肤病学 | 840篇 |
神经病学 | 2657篇 |
特种医学 | 715篇 |
外科学 | 5571篇 |
综合类 | 228篇 |
一般理论 | 9篇 |
预防医学 | 2401篇 |
眼科学 | 669篇 |
药学 | 1872篇 |
中国医学 | 164篇 |
肿瘤学 | 1920篇 |
出版年
2023年 | 285篇 |
2022年 | 650篇 |
2021年 | 1309篇 |
2020年 | 615篇 |
2019年 | 1144篇 |
2018年 | 1334篇 |
2017年 | 779篇 |
2016年 | 790篇 |
2015年 | 968篇 |
2014年 | 1459篇 |
2013年 | 1790篇 |
2012年 | 2833篇 |
2011年 | 2867篇 |
2010年 | 1672篇 |
2009年 | 1454篇 |
2008年 | 2271篇 |
2007年 | 2320篇 |
2006年 | 2132篇 |
2005年 | 1923篇 |
2004年 | 1744篇 |
2003年 | 1674篇 |
2002年 | 1512篇 |
2001年 | 194篇 |
2000年 | 152篇 |
1999年 | 205篇 |
1998年 | 233篇 |
1997年 | 179篇 |
1996年 | 168篇 |
1995年 | 143篇 |
1994年 | 110篇 |
1993年 | 99篇 |
1992年 | 85篇 |
1991年 | 67篇 |
1990年 | 58篇 |
1989年 | 42篇 |
1988年 | 56篇 |
1987年 | 40篇 |
1986年 | 26篇 |
1985年 | 46篇 |
1984年 | 42篇 |
1983年 | 48篇 |
1982年 | 51篇 |
1981年 | 57篇 |
1980年 | 50篇 |
1979年 | 27篇 |
1978年 | 28篇 |
1977年 | 30篇 |
1976年 | 23篇 |
1975年 | 28篇 |
1974年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Morphological changes in ocular surface in dry eyes and other disorders by impression cytology 总被引:1,自引:1,他引:0
Luis Rivas Maria A. Oroza Antonio Perez-Esteban Juan Murube-del-Castillo 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1992,230(4):329-334
A study was conducted on 107 eyes of 70 patients with dry eye disorders and mechanical and chemical extrinsic alterations and 64 eyes of 32 control subjects in order to describe a possible specific response of the conjunctival and corneal surface. We found the presence of snakelike chromatin cells and other nuclear changes, squamous metaplasia, and inflammatory cells in the conjunctiva in all groups. A decrease in goblet cell densities was also found in all groups, except for patients with blepharoconjunctivitis. The corneal cells were slightly larger in patients with keratoconjunctivitis sicca.Correspondence to: L. Rivas 相似文献
103.
João Luis Callegari Lopes Izabel Cristina Casanova Myrian C. Garcia de Figueireido Francisco Carlos Nather Wagner E. Paiva Avelar 《Archives of environmental contamination and toxicology》1992,23(3):351-354
The mussel Anodontites trapesialis (Lam, 1819) was used as an indicator of organochlorine pollutants in the Pardo River, located in the municipality of Ribeirão Preto (21° 07S and 47° 45W), State of São Paulo, Brazil.Biological monitoring was performed for one year at the site of a sugar cane grove on the left bank of the river. Forty-three animals were placed in two aluminum enclosures on the river bottom at this site and 4 animals of each enclosure were sacrificed for pesticide analysis at 3-month intervals, each collection corresponding to one season of the year.The animals were found to have been exposed to DDT, lindane, heptachlor, aldrin and dieldrin. Endrin was not detected in any of the analyses.Research supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). 相似文献
104.
Iranzu González Enrique J Andreu Angel Panizo Susana Inogés Ana Fontalba José Luis Fernández-Luna Mirella Gaboli Luis Sierrasesúmaga Salvador Martín-Algarra Javier Pardo Felipe Prósper Enrique de Alava 《Clinical cancer research》2004,10(2):751-761
PURPOSE AND EXPERIMENTAL DESIGN: The stem cell factor/KIT receptor loop may represent a novel target for molecular-based therapies of Ewing tumor. We analyzed the in vitro impact of KIT blockade by imatinib in Ewing tumor cell lines. RESULTS: KIT expression was detected in 4 of 4 Ewing tumor cell lines and in 49 of 110 patient samples (44.5%) by immunohistochemistry and/or Western blot analysis. KIT expression was stronger in Ewing tumors showing EWS-FLI1 nontype 1 fusions. Despite absence of c-kit mutations, constitutive and ligand-inducible phosphorylation of KIT was found in all tumor cell lines, indicating an active receptor. Treatment with KIT tyrosine kinase inhibitor imatinib (0.5-20 micro M) induced down-regulation of KIT phosphorylation and dose response inhibition of cell proliferation (IC(50), 12-15 micro M). However, imatinib administered alone at doses close to IC(50) for growth inhibition (10 micro M) did not induce a significant increase in apoptosis. We then analyzed if blockade of KIT loop through imatinib (10 micro M) was able to increase the antitumor in vitro effect of doxorubicin (DXR) and vincristine (VCR), drugs usually used in Ewing tumor treatment. Addition of imatinib decreased in 15-20 and 15-36% of the proliferative rate of Ewing tumor cells exposed to DXR and VCR, respectively, and increased in 15 and 30% of the apoptotic rate of Ewing tumor cells exposed to the same drugs. CONCLUSIONS: Inhibition of Ewing tumor cell proliferation by imatinib is mediated through blockade of KIT receptor signaling. Inhibition of KIT increases sensitivity of these cells to DXR and VCR. This study supports a potential role for imatinib in the treatment of Ewing tumor. 相似文献
105.
Phase II study of denileukin diftitox for relapsed/refractory B-Cell non-Hodgkin's lymphoma. 总被引:1,自引:0,他引:1
Nam H Dang Fredrick B Hagemeister Barbara Pro Peter McLaughlin Jorge E Romaguera Dan Jones Barry Samuels Felipe Samaniego Anas Younes Michael Wang Andre Goy Maria A Rodriguez Pamela L Walker Yolanda Arredondo Ann T Tong Luis Fayad 《Journal of clinical oncology》2004,22(20):4095-4102
PURPOSE: Denileukin diftitox is a fusion protein combining diphtheria toxin and interleukin-2 (IL-2) that targets tumor cells expressing the IL-2 receptor. Its efficacy has been shown in CD25+ cutaneous T-cell lymphoma, but not in B-cell non-Hodgkin's lymphoma (NHL). A phase II study was performed to evaluate the efficacy and tolerability of denileukin diftitox for relapsed or refractory B-cell NHL. PATIENTS AND METHODS: Patients with relapsed or refractory B-cell NHL were eligible. Tumor CD25 expression was determined by immunohistochemistry or flow cytometry. Denileukin diftitox was administered intravenously at a dose of 18 microg/kg once daily for 5 days every 3 weeks, up to eight cycles. RESULTS: Of the 45 patients assessable for response, 32 (71%) were refractory to the last chemotherapy treatment, and all were previously treated with rituximab. Three complete responses (6.7%) and eight partial responses (17.8%) were observed, for an overall response rate of 24.5%. Nine patients (20%) had stable disease. Objective response rates were similar in CD25+ (22%) and CD25- histologies (29%), as were stable disease rates (22% and 18%, respectively). For responding patients, the median time to treatment failure was 7 months, with a median follow-up in survivors of 18 months (range, 9 to 28 months), and the projected progression-free survival at 20 months was 24% (95% CI, 0% to 60%). Most toxicities were low-grade and transient. CONCLUSION: Denileukin diftitox seems to be effective in relapsed or refractory, CD25+ and CD25- B-cell NHL and is well-tolerated at the dosage evaluated. Evaluation of denileukin diftitox in combination with other agents may be warranted. 相似文献
106.
Allogeneic vaccination with a B7.1 HLA-A gene-modified adenocarcinoma cell line in patients with advanced non-small-cell lung cancer. 总被引:10,自引:0,他引:10
Luis E Raez Peter A Cassileth James J Schlesselman Kasi Sridhar Swaminathan Padmanabhan Eva Z Fisher Paulette A Baldie Eckhard R Podack 《Journal of clinical oncology》2004,22(14):2800-2807
PURPOSE: To determine the safety, immunogenicity, and clinical response to an allogeneic tumor vaccine for non-small-cell lung cancer, we conducted a phase I trial in patients with advanced metastatic disease. PATIENTS AND METHODS: We treated 19 patients with a vaccine based on an adenocarcinoma line (AD100) transfected with B7.1 (CD80) and HLA A1 or A2. Patients were vaccinated intradermally with 5 x 10(7) cells once every 2 weeks. Three vaccinations represented one course of treatment. If patients had complete response, partial response, or stable disease, they continued with the vaccinations for up to three courses (nine vaccinations). Immune response was assessed by a change between pre-study and postvaccination enzyme-linked immunospot frequency of purified CD8 T-cells secreting interferon-gamma in response to in vitro challenge with AD100. RESULTS: Four patients experienced serious adverse events that were unrelated to vaccine. Another four patients experienced only minimal skin erythema. All but one patient had a measurable CD8 response after three immunizations. The immune response of six surviving, clinically responding patients shows that CD8 titers continue to be elevated up to 150 weeks, even after cessation of vaccination. Overall, one patient had a partial response, and five had stable disease. Median survival for all patients is 18 months (90% CI, 7 to 23 months), with corresponding estimates of 1-year, 2-year, and 3-year survival of 52%, 30%, and 30%, respectively. HLA matching of vaccine, age, sex, race, and pathology did not bear a significant relation to response. CONCLUSION: Minimal toxicity and good survival in this small population suggest clinical benefit from vaccination. 相似文献
107.
Survival and neurologic outcomes in a randomized trial of motexafin gadolinium and whole-brain radiation therapy in brain metastases. 总被引:5,自引:0,他引:5
Minesh P Mehta Patrick Rodrigus C H J Terhaard Aroor Rao John Suh Wilson Roa Luis Souhami Andrea Bezjak Mark Leibenhaut Ritsuko Komaki Christopher Schultz Robert Timmerman Walter Curran Jennifer Smith See-Chun Phan Richard A Miller Markus F Renschler 《Journal of clinical oncology》2003,21(13):2529-2536
PURPOSE: This phase III randomized trial evaluated survival as well as neurologic and neurocognitive function in patients with brain metastases from solid tumors receiving whole-brain radiation therapy (WBRT) with or without motexafin gadolinium (MGd). PATIENTS AND METHODS: Patients were randomly assigned to 30 Gy of WBRT +/- 5 mg/kg/d MGd. Survival and time to neurologic progression determined by a blinded events review committee (ERC) were coprimary end points. Standardized investigator neurologic assessment and neurocognitive testing were evaluated. RESULTS: Four hundred one (251 non-small-cell lung cancer) patients were enrolled. There was no significant difference by treatment arm in survival (median, 5.2 months for MGd v 4.9 months for WBRT; P =.48) or time to neurologic progression (median, 9.5 months for MGd v 8.3 months for WBRT; P =.95). Treatment with MGd improved time to neurologic progression in patients with lung cancer (median, not reached for MGd v 7.4 months for WBRT; P =.048, unadjusted). By investigator, MGd improved time to neurologic progression in all patients (median, 4.3 months for MGd v 3.8 months for WBRT; P =.018) and in lung cancer patients (median, 5.5 months for MGd v 3.7 months for WBRT; P =.025). MGd improved neurocognitive function in lung cancer patients. CONCLUSION: The overall results did not demonstrate significant differences by treatment arm for survival and ERC time to neurologic progression. Investigator neurologic assessments demonstrated an MGd treatment benefit in all patients. In lung cancer patients, ERC- and investigator-determined time to neurologic progression demonstrated an MGd treatment benefit. MGd may improve time to neurologic and neurocognitive progression in lung cancer. 相似文献
108.
The metabolic syndrome among postmenopausal women in Ecuador. 总被引:1,自引:0,他引:1
Luis A Hidalgo Peter A Chedraui Nancy Morocho Mariela Alvarado Diana Chavez Angelica Huc 《Gynecological endocrinology》2006,22(8):447-454
BACKGROUND: The prevalence of the metabolic syndrome increases with age and after the onset of menopause, and may explain in part the apparent acceleration of cardiovascular disease in postmenopausal women. OBJECTIVE: To determine the prevalence of metabolic syndrome and related risk determinants among postmenopausal women in Ecuador. METHODS: Postmenopausal women >or=40 years of age, non-users of hormone therapy and with an intact uterus, were asked to participate in a metabolic syndrome screening and educational program at the Institute of Biomedicine of the Universidad Católica of Guayaquil, Ecuador. Sociodemographic data, waist circumference and blood pressure measurements were recorded, and a fasting blood sample obtained for serum glucose and lipid profile determinations. Woman were counseled and managed according to the results. Metabolic syndrome was defined in accordance with the criteria of the Third Adult Treatment Panel (ATP III). RESULTS: Three hundred and twenty-five postmenopausal women entered the program. Mean (+/-standard deviation) age was 55.9 +/- 8.1 years, 53.5% of them were aged >or=54 years (median). The prevalence of metabolic syndrome, according to ATP III criteria, was 41.5%. Using the same criteria, 38.8%, 16.6%, 56.9% and 54.2% of the women presented with hypertension, diabetes, hypertriglyceridemia and abdominal obesity, respectively. More than 40% of women determined to have hypertension or diabetes lacked knowing so. Logistic regression analysis determined that age increased the risk of presenting hypertension and diabetes (odds ratio (95% confidence interval): 2.0 (1.2-3.2) and 1.6 (0.9-3.0), respectively, p < 0.05), entities which in turn duplicated the risk of having high triglyceride levels. Sedentary women with <5 years since menopause onset were at higher risk of having abdominal obesity, which was directly related to diabetes and hypertension. CONCLUSIONS: In this postmenopausal Ecuadorian population the prevalence of the metabolic syndrome was high and its determinant factors related to age, time since menopause onset and sedentary habits. Because of the implications for cardiovascular risk, counseling programs directed toward high-risk populations should be encouraged. 相似文献
109.
P S F Barbosa A M C Martins A Havt Daniela O Toyama J S A M Evangelista D P P Ferreira P P Joazeiro Luis O S Beriam Marcos H Toyama M C Fonteles H S A Monteiro 《Toxicon》2005,46(4):376-386
Bothrops jararacussu myotoxin I (BthTx-I; Lys 49) and II (BthTX-II; Asp 49) were purified by ion-exchange chromatography and reverse phase HPLC. In this work we used the isolated perfused rat kidney method to evaluate the renal effects of B. jararacussu myotoxins I (Lys49 PLA2) and II (Asp49 PLA2) and their possible blockage by indomethacin. BthTX-I (5 microg/ml) and BthTX-II (5 microg/ml) increased perfusion pressure (PP; ct120=110.28+/-3.70 mmHg; BthTX I=171.28+/-6.30*mmHg; BthTX II=175.50+/-7.20*mmHg), renal vascular resistance (RVR; ct120=5.49+/-0.54 mmHg/ml.g(-1)min(-1); BthTX I=8.62+/-0.37*mmHg/ml g(-1)min(-1); BthTX II=8.9+/-0.36*mmHg/ml g(-1)min(-1)), urinary flow (UF; ct(120)=0.14+/-0.01ml g(-1)min(-1); BthTX I=0.32+/-0.05*ml g(-1)min(-1); BthTX II=0.37+/-0.01*ml g(-1)min(-1)) and glomerular filtration rate (GFR; ct120=0.72+/-0.10 ml g(-1)min(-1); BthTX I=0.85+/-0.13*ml g(-1)min(-1); BthTX II=1.22+/-0.28*ml g(-1)min(-1)). In contrast decreased the percent of sodium tubular transport (%TNa(+); ct(120)=79,76+/-0.56; BthTX I=62.23+/-4.12*; BthTX II=70.96+/-2.93*) and percent of potassium tubular transport (%TK(+);ct120=66.80+/-3.69; BthTX I=55.76+/-5.57*; BthTX II=50.86+/-6.16*). Indomethacin antagonized the vascular, glomerular and tubular effects promoted by BthTX I and it's partially blocked the effects of BthTX II. In this work also evaluated the antibacterial effects of BthTx-I and BthTx-II against Xanthomonas axonopodis. pv. passiflorae (Gram-negative bacteria) and we observed that both PLA2 showed antibacterial activity. Also we observed that proteins Also we observed that proteins chemically modified with 4-bromophenacyl bromide (rho-BPB) decrease significantly the antibacterial effect of both PLA2. In conclusion, BthTx I and BthTX II caused renal alteration and presented activity antimicrobial. The indomethacin was able to antagonize totally the renal effects induced by BthTx I and partially the effects promoted by BthTx II, suggesting involvement of inflammatory mediators in the renal effects caused by myotoxins. In the other hand, other effects could be independently of the enzymatic activity of the BthTX II and the C-terminal domain could be involved in both effects promoted for PLA2. 相似文献
110.
Induction of p53 up-regulated modulator of apoptosis messenger RNA by chemotherapeutic treatment of locally advanced breast cancer. 总被引:1,自引:0,他引:1
Rutger Middelburg Richard R de Haas Henk Dekker Ron M Kerkhoven Paula R Pohlmann Adolfo Fuentes-Alburo Alejandro Mohar Herbert M Pinedo Jan Lankelma 《Clinical cancer research》2005,11(5):1863-1869
PURPOSE: In biopsies of patients with locally advanced breast cancer, we investigated the in vivo changes of the gene expression pattern induced by chemotherapy to find genes that are potentially responsible for the efficacy of the drug. EXPERIMENTAL DESIGN: Early cellular responses to chemotherapy-induced damage, both in vivo and in vitro, were investigated by analyzing chemotherapy-induced changes in gene expression profiles. Core biopsies were taken from nine patients with locally advanced breast cancer, before and at 6 hours after initiation of doxorubicin-based chemotherapy. Both samples were cohybridized on the same microarray containing 18,000 cDNA spots. RESULTS: The analysis revealed marked differences in gene expression profile between treated and untreated samples. The gene which was most frequently found to be differentially expressed was p53 up-regulated modulator of apoptosis (PUMA). This gene was up-regulated in eight of nine patients with an average factor of 1.80 (range, 1.36-2.73). In vitro MCF-7 breast cancer cells exposed to clinically achievable doxorubicin concentrations for 6 hours revealed marked induction of PUMA mRNA, as well. CONCLUSIONS: This is the first report describing PUMA mRNA to be up-regulated as a response to chemotherapy in patients. Because PUMA is a known member of the family of BH3-only proapoptotic proteins, this finding suggests PUMA's potential importance for the response to anticancer drugs. 相似文献