全文获取类型
收费全文 | 9720篇 |
免费 | 433篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 243篇 |
妇产科学 | 95篇 |
基础医学 | 1543篇 |
口腔科学 | 345篇 |
临床医学 | 846篇 |
内科学 | 1734篇 |
皮肤病学 | 114篇 |
神经病学 | 786篇 |
特种医学 | 853篇 |
外科学 | 1279篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 458篇 |
眼科学 | 102篇 |
药学 | 788篇 |
中国医学 | 25篇 |
肿瘤学 | 889篇 |
出版年
2023年 | 30篇 |
2022年 | 61篇 |
2021年 | 81篇 |
2020年 | 62篇 |
2019年 | 118篇 |
2018年 | 132篇 |
2017年 | 110篇 |
2016年 | 141篇 |
2015年 | 203篇 |
2014年 | 266篇 |
2013年 | 405篇 |
2012年 | 584篇 |
2011年 | 624篇 |
2010年 | 363篇 |
2009年 | 374篇 |
2008年 | 535篇 |
2007年 | 612篇 |
2006年 | 579篇 |
2005年 | 592篇 |
2004年 | 566篇 |
2003年 | 563篇 |
2002年 | 625篇 |
2001年 | 150篇 |
2000年 | 120篇 |
1999年 | 164篇 |
1998年 | 149篇 |
1997年 | 148篇 |
1996年 | 124篇 |
1995年 | 98篇 |
1994年 | 94篇 |
1993年 | 87篇 |
1992年 | 73篇 |
1991年 | 73篇 |
1990年 | 77篇 |
1989年 | 64篇 |
1988年 | 61篇 |
1987年 | 51篇 |
1986年 | 67篇 |
1985年 | 73篇 |
1984年 | 62篇 |
1983年 | 54篇 |
1982年 | 54篇 |
1981年 | 60篇 |
1980年 | 49篇 |
1979年 | 33篇 |
1978年 | 45篇 |
1977年 | 34篇 |
1976年 | 36篇 |
1975年 | 44篇 |
1974年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
C J Coté N Rolf L M Liu N G Goudsouzian J F Ryan A Zaslavsky R Gore T D Todres S Vassallo D Polaner 《Anesthesiology》1991,74(6):980-987
This single-blind study examined four levels of monitoring in 402 pediatric cases. Patients were randomly assigned to one of four groups: 1) oximeter and capnograph; 2) only oximeter; 3) only capnograph; or 4) neither oximeter nor capnograph data available to the anesthesia team. An anesthesiologist, not involved in patient care, observed all cases and continuously recorded hemoglobin oxygen saturation (Spo2), ECG, expired CO2, and the oximeter plethysmographic output. Mean age, weight, ASA physical status, airway management (mask or endotracheal tube), and anesthetic technique were similar in each group. Two-hundred sixty problems were documented in 153 patients. Fifty-nine events in 43 patients resulted in "major" desaturation (Spo2 less than or equal to 85% for greater than or equal to 30 s). Fifteen "major" capnograph events (esophageal intubation, disconnection, accidental extubation, or obstructed endotracheal tube) were observed in 11 patients; 8 of these also developed varying degrees of desaturation. One-hundred thirty "minor" desaturation events (Spo2 less than or equal to 95% for greater than 60 s) and 79 "minor" desaturation events (hypercarbaria or hypocarbia) were observed. A number of problems fulfilled criteria in multiple categories. Infants less than or equal to 6 months of age had the highest incidence of major desaturation events (18 of 65 [27%]) compared to toddlers 7-24 months of age or children greater than 24 months of age (P less than 0.001). Blinding the oximeter data increased the number of patients (12 vs. 31) experiencing major desaturation events (P = 0.003); blinding the capnograph data altered neither the frequency of desaturation events nor the incidence of major capnograph events.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
72.
73.
Keitaro Hashimoto Otto Hauswirth Heinz D. Wehner Rolf Ziskoven 《Naunyn-Schmiedeberg's archives of pharmacology》1979,307(1):9-19
Summary The pacemaker current — i
K2 — in cardiac Purkinje fibres was analysed using the voltage clamp technique described by Deck et al. (1964). (–)-Adrenaline (5.5 · 10–6 M) causes the wellknown shift of the Hodkin-Huxley kinetics in the depolarizing direction. Procaine (7.3·10–4 M) does not cause any further shift of s
in the presence of adrenaline. Atenolol (3.8·10–5 M) causes a backshift of the kinetics in the negative direction in the presence of adrenaline and procaine. The instantaneous current-voltage relationship (
) is altered neither with adrenaline, nor with procaine or atenolol. The results exclude the possibility that the local anaesthetic side effect of many beta-adrenoceptor blocking agents may be involved in the backshift of the s-kinetics. The voltage dependence of the reciprocals of the time constants is shifted in a similar way as s
by the sympathomimetic or blocking drugs. Following the application of (–)-adrenaline (5.5·10–6 M) the (–)-isomere of penbutolol (1.7 and 3.5·10–6 M) is about equally effective in shifting the kinetics back as the (+)-isomere (3.5·10–5 M). In the presence of (–)-adrenaline, the (+)- and (–)-forms of penubutolol cause virtually no change of the instantaneous current-voltage relationship,
. Thus, (–)-adrenaline and (+)- and (–)-penbutolol are aiming for the s-kinetics whose voltage dependence is controlled by the electric field near the i
K2-channel of the membrane and do not influence the number of the i
K2-channels. These findings suggest that the sympathomimetic or blocking agents influence the s-kinetics of the pacemaker current i
K2 by altering the electric field; the fully activated current-voltage relationship which is proportional to the number of the open i
K2-channels is not subject to any appreciable modification. The results conclusively show that the kinetics of the pacemaker current can be controlled by beta-adrenoceptors. 相似文献
74.
Vaccination of patients with advanced ovarian carcinoma with the anti-idiotype ACA125: immunological response and survival (phase Ib/II). 总被引:7,自引:0,他引:7
Silke Reinartz Siegmund K?hler Harald Schlebusch Karl Krista Patrick Giffels Kirsten Renke Jens Huober Volker M?bus Rolf Kreienberg Andreas DuBois Paul Sabbatini Uwe Wagner 《Clinical cancer research》2004,10(5):1580-1587
PURPOSE: A Phase I/IIb multicenter study was conducted to evaluate the safety and immunogenicity of the anti-idiotypic antibody vaccine ACA125 that functionally imitates the tumor antigen CA125 in 119 patients with advanced ovarian carcinoma. A preliminary report on the initial 42 patients demonstrated safety and immunogenicity. EXPERIMENTAL DESIGN: Using the complete intention-to-treat population (n = 119) who received a mean of 9.7 ACA125 applications, survival was analyzed with respect to immunological responses. RESULTS: In 81 patients (68.1%), a specific anti-anti-idiotypic antibody (Ab3) response could be induced. Additionally, the development of CA125-specific antibodies (Ab1') and antibody-dependent cell-mediated cytotoxicity of CA125-positive tumor cells was observed in 50.4% and 26.9% of patients, respectively. The median survival of all patients was 19.4 months (range, 0.5-56.1 months). Ab3-positive patients showed a significantly longer survival (median, 23.4 months; P < 0.0001) as compared with Ab3-negative patients (median, 4.9 months). A positive Ab3 response remained associated with longer survival when controlling for other prognostic factors including FIGO (International Federation of Gynecologists and Obstetricians) stage, response to and type of first-line chemotherapy, number of previous treatments, or concomitant antitumor therapy. With regard to safety, repeated vaccination was well tolerated. No serious adverse events related to the application of ACA125 occurred. CONCLUSIONS: Although the uncontrolled design of this study prevents definitive conclusions with respect to subgroups, the data support a relationship between Ab3 response and survival time. Thus, the need for further randomized, controlled clinical trials to establish efficacy of the vaccine ACA125 seems to be indicated. 相似文献
75.
76.
Xi-Hui Yang Randal A Hand Chad A Livasy William G Cance Rolf J Craven 《Tumour biology》2003,24(2):61-69
OBJECTIVE: Tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (Tie-1) is a receptor tyrosine kinase that regulates angiogenesis and antiapoptotic survival signaling. Tie-1 expression is generally associated with endothelial cells and neovascularization. We previously identified Tie-1 in human breast tumor samples using a PCR-based screen for protein kinases expressed in breast tumors. The purpose of this study was to determine the cell types expressing Tie-1, whether Tie-1 is expressed in tumor cells, and to examine the regulation of Tie-1 in breast cancer. METHODS: Tie-1 expression was analyzed by Western blot and immunohistochemistry using an antibody to the carboxy terminus of Tie-1. Tie-1 expression was determined in a variety of cancer cell lines, clinical breast and colon tumor samples, and in corresponding benign tissue from the same patient. Tie-1 expression and distribution in breast tumors was scored by immunohistochemistry. RESULTS: Tie-1 was overexpressed in 14/23 breast tumors compared with 0/9 corresponding normal tissues from the same patients. Immunohistochemistry revealed that Tie-1 was overexpressed in epithelial breast cancer cells and ductal carcinoma in situ. In all breast tumor samples, Tie-1 was expressed as a truncated 40- to 43-kD doublet consisting of the intracellular portion of the protein, which contains the tyrosine kinase catalytic domain. The 40- to 43-kD Tie-1 doublet was expressed in a broad variety of cell lines. CONCLUSIONS: We have shown that breast cancer cells overexpress a cleaved form of the Tie-1 protein. Our results implicate the intracellular domain of Tie-1, which includes the catalytic kinase domain, in breast cancer progression. 相似文献
77.
M Martin M Spielmann M Namer A duBois C Unger D Dodwell P Vodvarka M Lind H Calvert A Casado L Zelek A Lluch E Carrasco L Kayitalire C Zielinski 《Annals of oncology》2003,14(8):1246-1252
BACKGROUND: To assess antitumor activity and toxicity of pemetrexed in metastatic breast cancer (MBC) patients previously treated with anthracyclines. PATIENTS AND METHODS: Seventy-seven MBC patients from 12 European institutions were entered into the study. Seventy-two patients were considered evaluable for response and toxicity. Forty-two patients were classified as anthracycline-failure (relapse >30 days after completion of a prior anthracycline regimen) and 30 as anthracycline-refractory (progression within 30 days after anthracycline therapy). Pemetrexed 600 mg/m(2) was administered intravenously every 3 weeks until progressive disease or unacceptable toxicity. RESULTS: There were three complete and 12 partial responders [response rate 21% (95% confidence interval 12%)]. Response rates in the anthracycline-failure and anthracycline-refractory groups were 24% and 17%, respectively. A subset of 31 patients pretreated with anthracyclines and taxanes had a response rate of 26%. Median duration of response and median survival were 5.5 and 10.7 months, respectively (13 months in the failure group and 5.7 months for refractory). Grade 3/4 toxicities included neutropenia and thrombocytopenia in 56% and 19% of patients, respectively. Nine patients (12%) experienced neutropenic fever. Grade 3/4 non-hematological toxicities included skin rash (10%), nausea (12%), fatigue (10%) and stomatitis (5%). CONCLUSION: Our trial demonstrates pemetrexed to be active in breast cancer, with manageable toxicity. Activity of pemetrexed did not appear to be adversely affected by prior taxane, 5-fluorouracil or endocrine treatments. 相似文献
78.
Claus R?del Gerhard G Grabenbauer Thomas Papadopoulos Werner Hohenberger Hans-Joachim Schmoll Rolf Sauer 《Journal of clinical oncology》2003,21(16):3098-3104
PURPOSE: The purpose of this study was to establish the feasibility and efficacy of preoperative radiotherapy (RT) with concurrent capecitabine and oxaliplatin (XELOX-RT) in patients with rectal cancer. PATIENTS AND METHODS: Thirty-two patients with locally advanced (T3/T4) or low-lying rectal cancer received preoperative RT (total dose, 50.4 Gy). Capecitabine was administered concurrently at 825 mg/m2 bid on days 1 to 14 and 22 to 35, with oxaliplatin starting at 50 mg/m2 on days 1, 8, 22, and 29 with planned escalation steps of 10 mg/m2. End points of the phase II study included downstaging, histopathologic tumor regression, resectability of T4 disease, and sphincter preservation in patients with low-lying tumors. RESULTS: Dose-limiting grade 3 gastrointestinal toxicity was observed in two of six patients treated with 60 mg/m2 of oxaliplatin. Thus, 50 mg/m2 was the recommended dose for the phase II study. Toxicities observed at this dose level were generally mild, with only two cases of short-lived grade 3 diarrhea. Myelosuppression, mainly leukopenia, was restricted to grade 2 in 19% of patients. T-category downstaging was achieved in 17 (55%) of 31 operated patients, and 68% of patients had negative lymph nodes. Pathologic complete response was found in 19% of the resected specimens. Radical surgery with free margins could be performed in 79% of patients with T4 disease, and 36% of patients with tumors < or = 2 cm from the dentate line had sphincter-saving surgery. CONCLUSION: Preoperative XELOX-RT is a feasible and well tolerated treatment. This regimen is proposed for phase III evaluation comparing standard fluorouracil-based therapy with XELOX chemoradiotherapy. 相似文献
79.
Patient-controlled intranasal analgesia: effective alternative to intravenous PCA for postoperative pain relief 总被引:2,自引:0,他引:2
Susanne Toussaint MD DEAA Julia Maidl MD Rolf Schwagmeier MD Hans Walter Striebel MD PhD DEAA 《Journal canadien d'anesthésie》2000,47(4):299-302
PURPOSE: To investigate whether the nasal route for fentanyl administration in patient-controlled analgesia (PCA) provides as effective postoperative analgesia as intravenous PCA. METHODS: Patient-controlled intranasal or intravenous analgesia with fentanyl was investigated in 48 patients (ASA I-III) on the day of surgery (orthopedic, abdominal or thyroid) in a prospective, randomized, double-blind, double-dummy study. Fentanyl was given in a bolus of 25 microg for intranasal and 17.5 microg for i.v. PCA, lockout interval six minutes. The first requested dose was doubled in both groups. Pain intensity (101-point numerical rating scale) and vital parameters were observed at 11 measurement points during the 240 min study. Patients were asked for side effects at every measurement point and for their satisfaction at the end of the study by the same investigator (J.M.). RESULTS: Onset of analgesia, the first reduction in pain intensity on the numerical rating scale, was 21 +/- 11 min (range 15-45 min) in intranasal and 22 +/- 16 min (range 15-90 min) in i.v. PCA. Pain intensity was reduced from 55 +/- 11 to 11 +/- 10 in the intranasal group and from 53 +/- 8 to 11 +/- 6 in the i.v. PCA group. Vital parameters remained stable and side effects were comparable in both groups. The judgement "excellent" or "good" was given by 21 of 23 patients treated intranasally and 24 of 25 patients treated intravenously. CONCLUSION: Intranasal PCA with fentanyl was an effective alternative to i.v. PCA in postoperative patients. 相似文献
80.
Els M J J Berns Jan G M Klijn Maxime P Look Nicolai Grebenchtchikov Rolf Vossen Harry Peters Anneke Geurts-Moespot Henk Portengen Iris L van Staveren Marion E Meijer-van Gelder Bert Bakker Fred C G J Sweep John A Foekens 《Clinical cancer research》2003,9(4):1253-1258
PURPOSE: In recent studies, we showed that TP53 gene mutation or high levels of cytosolic vascular endothelial growth factor (VEGF) in estrogen receptor (ER)-alpha-positive primary breast tumors predict a poor disease outcome for patients treated with first-line tamoxifen for advanced disease. Mutant TP53 may up-regulate VEGF, whereas, on the other hand, wild-type TP53 may decrease VEGF production. EXPERIMENTAL DESIGN: In the present study, we aimed to assess the combined predictive value of TP53 gene mutation and VEGF status of 160 advanced breast cancer patients with ER-positive tumors who were treated with tamoxifen (median follow-up from start of tamoxifen treatment, 64 months). To assess TP53 gene mutation status, the entire open reading frame was sequenced; for VEGF status, an ELISA was used. RESULTS: In univariate analysis, both TP53 gene mutation (28% of the tumors) and a VEGF level above the median value were significantly associated with a short progression-free survival, post-relapse overall survival, and a poor rate of response to tamoxifen. In Cox multivariate regression analysis including the traditional predictive factors, the addition of TP53 gene mutation and VEGF status, alone or in combination, significantly predicted a poor efficacy of tamoxifen treatment. When the two factors were combined, a significantly decreased odds ratio was seen for the rate of response (odds ratio, 0.27). Similarly, an increased hazard ratio (HR) was seen for progression-free survival (HR, 2.32) and post-relapse overall survival (HR, 1.68) in the group with mutant TP53 and high VEGF compared with the group with both risk factors absent. CONCLUSIONS: Combined TP53 gene mutation status and high VEGF levels of ER-positive primary breast tumors independently predict a poor course of the disease of patients with advanced breast cancer treated with tamoxifen. These patients, having unfavorable tumor characteristics, might benefit more from other types of (individualized) treatment protocols. 相似文献