全文获取类型
收费全文 | 36951篇 |
免费 | 2602篇 |
国内免费 | 160篇 |
专业分类
耳鼻咽喉 | 281篇 |
儿科学 | 1078篇 |
妇产科学 | 782篇 |
基础医学 | 4594篇 |
口腔科学 | 642篇 |
临床医学 | 3566篇 |
内科学 | 8314篇 |
皮肤病学 | 563篇 |
神经病学 | 3847篇 |
特种医学 | 1138篇 |
外国民族医学 | 1篇 |
外科学 | 5212篇 |
综合类 | 526篇 |
一般理论 | 31篇 |
预防医学 | 3039篇 |
眼科学 | 741篇 |
药学 | 2617篇 |
1篇 | |
中国医学 | 54篇 |
肿瘤学 | 2686篇 |
出版年
2023年 | 234篇 |
2022年 | 350篇 |
2021年 | 711篇 |
2020年 | 479篇 |
2019年 | 703篇 |
2018年 | 808篇 |
2017年 | 619篇 |
2016年 | 674篇 |
2015年 | 816篇 |
2014年 | 1158篇 |
2013年 | 1625篇 |
2012年 | 2416篇 |
2011年 | 2708篇 |
2010年 | 1502篇 |
2009年 | 1385篇 |
2008年 | 2279篇 |
2007年 | 2580篇 |
2006年 | 2446篇 |
2005年 | 2543篇 |
2004年 | 2290篇 |
2003年 | 2176篇 |
2002年 | 2011篇 |
2001年 | 338篇 |
2000年 | 255篇 |
1999年 | 394篇 |
1998年 | 449篇 |
1997年 | 337篇 |
1996年 | 335篇 |
1995年 | 277篇 |
1994年 | 242篇 |
1993年 | 271篇 |
1992年 | 233篇 |
1991年 | 219篇 |
1990年 | 181篇 |
1989年 | 160篇 |
1988年 | 174篇 |
1987年 | 152篇 |
1986年 | 117篇 |
1985年 | 179篇 |
1984年 | 246篇 |
1983年 | 206篇 |
1982年 | 242篇 |
1981年 | 248篇 |
1980年 | 242篇 |
1979年 | 118篇 |
1978年 | 131篇 |
1977年 | 127篇 |
1976年 | 114篇 |
1974年 | 92篇 |
1973年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
Factors associated with breast cancer clinical trials participation and enrollment at a large academic medical center. 总被引:5,自引:0,他引:5
Michael S Simon Wei Du Lawrence Flaherty Philip A Philip Patricia Lorusso Cheryl Miree Daryn Smith Diane R Brown 《Journal of clinical oncology》2004,22(11):2046-2052
PURPOSE: The practice patterns of medical oncologists at a large National Cancer Institute Comprehensive Cancer Center in Detroit, MI were evaluated to better understand factors associated with accrual to breast cancer clinical trials. PATIENTS AND METHODS: From 1996 to 1997, physicians completed surveys on 319 of 344 newly evaluated female breast cancer patients. The 19-item survey included clinical data, whether patients were offered clinical trial (CT) participation and enrollment, and when applicable, reasons why they were not. Multivariate analyses using logistic regression were performed to evaluate predictors of an offer and enrollment. RESULTS: The patients were 57% white, 32% black, and 11% other/unknown race. One hundred six (33%) were offered participation and 36 (34%) were enrolled. In multivariate analysis, CTs were less likely offered to older women (mean age, 52 years for those offered v 57 years for those not offered; P =.0005) and black women (21% of blacks offered v 42% of whites; P =.0009). Women with stage 1 disease, poor performance status, and those who were previously diagnosed were also less likely to be offered trials. None of these factors were significant predictors of enrollment. Women were not offered trials because of ineligibility (57%), lack of available trials (41%), and noncompliance (2%). Reasons for failed enrollment included patient refusal (88%) and failed eligibility (12%). CONCLUSION: It is important for cooperative groups to design studies that will accommodate a broader spectrum of patients. Further work is needed to assess ways to improve communication about breast cancer CT participation to all eligible women. 相似文献
172.
Rachael Z Stolzenberg-Solomon Paul Limburg Michael Pollak Philip R Taylor Jarmo Virtamo Demetrius Albanes 《Cancer epidemiology, biomarkers & prevention》2004,13(3):438-444
To investigate whether insulin-like growth factor (IGF)-1 and IGF-binding protein-3 (IGFBP-3) are prospectively associated with exocrine pancreatic cancer, we conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of 29,133 male Finnish smokers, aged 50-69 years. To avoid the potential influence of subclinical cancer on IGF-1 and IGFBP-3, all subjects in this study were alive without clinical evidence of cancer during their 5th year of the cohort follow-up. Four hundred randomly selected cohort controls and 93 incident pancreatic adenocarcinoma cases that occurred between their 5th follow-up year through 1997 (i.e., up to 12.7 years of follow-up) were included in this study. Concentrations of IGF-1 and IGFBP-3 were measured in serum samples obtained at baseline using ELISA. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models, adjusted for confounders. Neither IGF-1, IGFBP-3, nor the IGF-1:IGFBP-3 molar ratio was significantly associated with pancreatic cancer: highest compared to lowest tertile, OR = 0.67, 95% CI 0.37-1.21, P trend = 0.17; OR = 0.70, 95% CI 0.38-1.27, P trend = 0.12; and OR = 0.85, 95% CI 0.50-1.46, P trend = 0.54, respectively. Our results do not support the hypothesis that serum IGF-1 and IGFBP-3 concentrations are associated with pancreatic cancer risk among male smokers. Further studies are necessary to evaluate these associations in other populations. 相似文献
173.
Polymorphisms in interleukin -2, -6, and -10 are not associated with gastric cardia or esophageal cancer in a high-risk chinese population. 总被引:7,自引:0,他引:7
174.
175.
David P Ryan Joseph P Eder Thomas Puchlaski Michael V Seiden Thomas J Lynch Charles S Fuchs Philip C Amrein Darrell Sonnichsen Jeffrey G Supko Jeffrey W Clark 《Clinical cancer research》2004,10(7):2222-2230
PURPOSE: BMS-214662 is a nonsedating benzodiazepine derivative that exhibits broad spectrum cytotoxicity against human solid tumor cell lines and potently inhibits farnesylation of the H-ras and K-ras oncogenic proteins. This report describes the initial Phase I clinical trial of the compound. The main objective of the study was to determine the dose-limiting toxicities and the maximum tolerated dose of BMS-214662 when administered as a single dose i.v. over 1 h every 21 days to patients with advanced solid tumors. EXPERIMENTAL DESIGN: Patients with advanced solid tumors and adequate organ function were eligible for the study. The dose was escalated according to a modified Fibonacci schedule after evaluating groups of at least three patients for toxicity during the first cycle of therapy at each dose level. Pharmacokinetic and pharmacodynamic studies were performed after administration of the two initial doses. RESULTS: The dose of BMS-214662 was escalated from 36 to 225 mg/m(2) through 5 intermediate dose levels in a total of 44 patients. Dose-limiting toxicities occurred in 3 of the 13 (23%) patients during the first cycle of treatment with 225 mg/m(2), consisting of grade 3 nausea/vomiting in 2 patients and grade 3 diarrhea in another patient. In addition, four of these patients experienced reversible grade 3 transaminitis, which was not considered to be dose-limiting. At the recommended dose for Phase II studies, 200 mg/m(2), the most common side effects were reversible transaminitis, nausea, and vomiting. Although there were no objective responses, one patient with pancreatic cancer continues to receive treatment more than 3.5 years after entering the study. BMS-214662 exhibited linear pharmacokinetics and had a mean biological half-life of 1.55 +/- 0.27 h and a total body clearance of 21.8 +/- 10.8 liters/h/m(2), with a low apparent volume of distribution at steady state (31.5 +/- 12.9 liters/m(2)). In patients treated with the recommended Phase II dose, the mean maximum plasma concentration of the drug was 6.57 +/- 2.94 microg/ml, and farnesyltransferase activity in peripheral blood mononuclear cells decreased to a nadir of 10.5 +/- 6.4% of baseline at the end of the infusion but fully recovered within 24 h. CONCLUSIONS: BMS-214662 can be delivered safely as a single 1-h i.v. infusion at a dose that results in pronounced inhibition of farnesyltransferase activity in peripheral blood mononuclear cells. However, the duration of enzyme inhibition was transient, recovering in parallel with the decline in plasma concentrations of this rapidly eliminated drug. Because indications of anticancer activity were observed in several patients, further optimization of the administration schedule for this promising new compound is warranted. 相似文献
176.
Anthony T C Chan Brigette B Y Ma Y M Dennis Lo S F Leung W H Kwan Edwin P Hui Tony S K Mok Michael Kam Lisa S Chan Samuel K W Chiu K H Yu K Y Cheung Karen Lai Maria Lai Frankie Mo Winnie Yeo Ann King Philip J Johnson Peter M L Teo Benny Zee 《Journal of clinical oncology》2004,22(15):3053-3060
PURPOSE: To assess the efficacy of neoadjuvant paclitaxel and carboplatin (TC) followed by concurrent cisplatin and radiotherapy (RT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) and to monitor treatment response with plasma Epstein-Barr virus (EBV) DNA. PATIENTS AND METHODS: Thirty-one patients with International Union Against Cancer stages III and IV undifferentiated NPC had two cycles of paclitaxel (70 mg/m2 on days 1, 8, and 15) and carboplatin (area under the curve 6 mg/mL/min on day 1) on a 3-weekly cycle, followed by 6 to 8 weeks of cisplatin (40 mg/m2 weekly) and RT at 66 Gy in 2-Gy fractions. Plasma EBV DNA was measured serially using the real-time quantitative polymerase chain reaction method. Results All patients completed planned treatment. Response to neoadjuvant TC was as follows: 12 patients (39%) achieved partial response (PR) and 18 achieved (58%) complete response (CR) in regional nodes; five patients (16%) achieved PR and no patients achieved CR in nasopharynx. At 6 weeks after RT, one patient (3%) achieved PR and 30 patients (97%) achieved CR in regional nodes, and 31 patients (100%) achieved CR in nasopharynx; 29 patients (93%) had EBV DNA level of less than 500 copies/mL. Neoadjuvant TC was well tolerated, and the most common acute toxicity of cisplatin plus RT was grade 3 mucositis (55%). At median follow-up of 33.7 months (range, 7 to 39.3 months), six distant and three locoregional failures occurred. Plasma EBV DNA level increased significantly in eight of nine patients who experienced treatment failure but did not increase in those who did not. The 2-year overall and progression-free survival rates were 91.8% and 78.5%, respectively. CONCLUSION This strategy was feasible and resulted in excellent local tumor control. Serial plasma EBV DNA provides a noninvasive method of monitoring response in NPC. 相似文献
177.
Philip AT Amin MB Tamboli P Lee TJ Hill CE Ro JY 《The American journal of surgical pathology》2000,24(9):1286-1290
Accurate pathologic staging of carcinomas of the urinary bladder involves assessment of invasion by the tumor into the bladder wall and beyond into perivesical soft tissue. The presence of tumor within perivesical soft tissue implies pathologic stage pT3 (AJCC/UICC system, 1997). In traditional textbooks of histology, anatomy, pathology, and in the literature, other than a single case report and a brief reference in another paper, there is no information on the presence of adipose tissue in the lamina propria or muscularis propria of the urinary bladder. Nine hundred forty-three sections from 139 cystectomy specimens were evaluated for the presence, location, and quantity of adipose tissue within the lamina propria and muscularis propria. The histology of the perivesical soft tissues and the nature of its delineation from muscularis propria were also analyzed. Adipose tissue was seen within the lamina propria in 53% (74 of 139) of cystectomies and in 17.6% (166 of 943) of the examined sections. It was located predominantly in the deep lamina propria (at or below the muscularis mucosae) in 81.1% (60 of 74) of the cystectomies and in 91% (151 of 166) of the sections. Within the lamina propria it was predominantly seen as small localized aggregates in 92% (153 of 166) of sections. All cases showed adipose tissue within the muscularis propria. Adipose tissue was identified within the superficial (inner) muscularis propria in 54% (512 of 943) of sections and was predominantly in small aggregates in 80.5% (412 of 512) of sections. It was in moderate to abundant quantities within the deep (outer) muscularis propria in 60.7% (572 of 943) of sections. The perivesical soft tissue was almost exclusively composed of adipose tissue with variable vascularity. Delineation of the perivesical adipose tissue from the deep (outer) muscularis propria was typically indistinct because muscle bundles of the latter haphazardly merged with the perivesical adipose tissue. Based on these findings, we conclude that adipose tissue is frequently present in the lamina propria and muscularis propria of the urinary bladder wall, and is usually scant in the former location and frequently abundant in the latter. Awareness of the high frequency of adipose tissue within the urinary bladder wall has prognostic and therapeutic implications. In transurethral resection of bladder tumor (TURBT) specimens, misinterpretation of tumor infiltrating adipose tissue within lamina propria (pT1) as perivesical soft tissue involvement (pT3) may potentially result in unwarranted aggressive management. Substaging of muscle invasive tumors should be performed in cystectomy specimens only, because the junction of muscularis propria and the perivesical adipose tissue is typically ill-defined. Muscularis propria adipose tissue in TURBT specimens may be erroneously assumed to be perivesical adipose tissue, potentially leading to overstaging of the primary tumor. 相似文献
178.
MIC-1 serum level and genotype: associations with progress and prognosis of colorectal carcinoma. 总被引:9,自引:0,他引:9
David A Brown Robyn L Ward Philip Buckhaults Tao Liu Katharine E Romans Nicholas J Hawkins Asne R Bauskin Kenneth W Kinzler Bert Vogelstein Samuel N Breit 《Clinical cancer research》2003,9(7):2642-2650
PURPOSE: Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the tumor growth factor beta (TGF-beta) superfamily. Several observations suggest that it plays a role in colorectal carcinoma (CRC). In particular, MIC-1 is markedly up-regulated in colorectal cancers as well as in premalignant adenomas. This study examines the relationship of serum MIC-1 levels and genotypes to clinical and pathologic features of colonic neoplasia. Experimental Design: We confirmed the presence of MIC-1 in CRC tissue and the cell line CaCo-2. The normal range for serum MIC-1 levels was defined in 260 healthy blood donors, and the differences between normal subjects and 193 patients having adenomatous polyps or CRC were then determined. In a separate cohort of 224 patients, we evaluated the relationship of MIC-1 serum level and genotype to standard tumor parameters and outcome measures. RESULTS: MIC-1 was expressed in CRC tissue and the cancer cell line CaCo-2. There was a progressive increase in serum MIC-1 levels between normal individuals [mean (M) = 495 pg/ml, SD = 210), those with adenomatous polyps (M = 681 pg/ml, SD = 410), and those with CRC (M = 783 pg/ml, SD = 491)]. Serum MIC-1 level was correlated with the extent of disease so that the levels were higher in patients with higher Tumor-Node-Metastasis stage. There were significant differences in time to relapse and overall survival between subjects with different MIC-1 levels and genotypes. CONCLUSIONS: This study identifies a strong association between MIC-1 serum levels and neoplastic progression within the large bowel. We suggest that the measurement of serum MIC-1 levels and determination of MIC-1 genotype may have clinical use in the management of patients with CRC. 相似文献
179.
Susan F Slovin Govindaswami Ragupathi Cristina Musselli Krystyna Olkiewicz David Verbel Scott D Kuduk Jacob B Schwarz Dalibor Sames Samuel Danishefsky Philip O Livingston Howard I Scher 《Journal of clinical oncology》2003,21(23):4292-4298
PURPOSE: We report the synthesis of a mucin-related O-linked glycopeptide, alpha-N-acetylgalactosamine-O-serine/threonine (Tn), which is highly simplistic in its structure and can induce a relevant humoral response when given in a trimer or clustered (c) formation. We tested for an antitumor effect, in the form of a change in the posttreatment versus pretreatment prostate-specific antigen (PSA) slopes, that might serve as a surrogate for effectiveness of vaccines in delaying the time to radiographic progression. METHODS: We compared the antibody response to immunization with two conjugates, Tn(c)-keyhole limpet hemocyanin (KLH) and Tn(c)-palmitic acid (PAM) with the saponin immunologic adjuvant QS21, in a phase I clinical trial in patients with biochemically relapsed prostate cancer. Patients received Tn(c)-KLH vaccine containing either 3, 7, or 15 microg of Tn(c) per vaccination. Ten patients received 100 microg of Tn(c)-PAM. QS21 was included in all vaccines. Five vaccinations were administered subcutaneously during 26 weeks with an additional booster vaccine at week 50. RESULTS: Tn(c), when given with the carrier molecule KLH and QS21, stimulated the production of high-titer immunoglobulin M (IgM) and IgG antibodies. Inferior antibody responses were seen with T(c)-PAM. There was no evidence of enhanced immunogenicity with increasing doses of vaccine. An antitumor effect in the form of a decline in posttreatment versus pretreatment PSA slopes was also observed. CONCLUSION: A safe synthetic conjugate vaccine in a trimer formation was developed that can break immunologic tolerance by inducing specific humoral responses. It seemed to affect the biochemical progression of the disease as determined by a change in PSA log slope. 相似文献
180.
Ruth Plummer Charlotte Rees Andrew Hughes Philip Beale Martin Highley Jose Trigo Sathyarathnarn Gokul Ian Judson Hilary Calvert Ann Jackman Fraser Mitchell Robert Smith Edwin Douglass 《Clinical cancer research》2003,9(4):1313-1322
PURPOSE: ZD9331 is a novel, direct-acting antifolate cytotoxic that does not require polyglutamation for activity, and is a specific thymidylate synthase inhibitor. This Phase I trial aimed to determine the maximum tolerated dose of ZD9331, given as a 30-min i.v. infusion on days 1 and 8 of a 21-day cycle. Pharmacokinetic parameters and tumor response were also assessed. EXPERIMENTAL DESIGN: A total of 71 patients, with a range of solid malignancies and refractory to standard therapies (44% had received > or =3 prior chemotherapy regimens), were treated. The most common malignancies were colorectal cancer (35% of patients) and ovarian cancer (31%). ZD9331 was escalated from 4.8 mg/m(2)/day. RESULTS: Dose-limiting toxicity occurred at 162.5 mg/m(2) ZD9331, with grade 4 thrombocytopenia, grade 4 neutropenia lasting > or =7 days, and grade 3 nonhematologic toxicity. Plasma clearance of ZD9331 was slow and dose-dependent; however, ZD9331 pharmacokinetics were nonlinear. Pharmacodynamics of ZD9331 were determined by measurement of plasma deoxyuridine, which increased at all of the dose levels; dose-related increases in plasma deoxyuridine were significant (P = 0.003) on day 5. Stable disease was observed in 37% of patients; 23% of ovarian cancer patients had a > or =50% reduction in CA125 levels. CONCLUSIONS: The maximum tolerated dose of this schedule was 130 mg/m(2). The toxicity profile at this dose was acceptable, with 7 of 28 patients treated developing grade 3/4 neutropenia and thrombocytopenia, 2 grade 4 diarrhea, and 2 grade 3/4 rash. This schedule was convenient and demonstrated activity in extensively pretreated patients; therefore, this is the recommended dose for study in Phase II trials. 相似文献