全文获取类型
收费全文 | 6594篇 |
免费 | 426篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 330篇 |
妇产科学 | 113篇 |
基础医学 | 946篇 |
口腔科学 | 125篇 |
临床医学 | 612篇 |
内科学 | 1517篇 |
皮肤病学 | 90篇 |
神经病学 | 769篇 |
特种医学 | 127篇 |
外科学 | 588篇 |
综合类 | 57篇 |
一般理论 | 10篇 |
预防医学 | 631篇 |
眼科学 | 51篇 |
药学 | 394篇 |
中国医学 | 9篇 |
肿瘤学 | 632篇 |
出版年
2024年 | 7篇 |
2023年 | 80篇 |
2022年 | 123篇 |
2021年 | 213篇 |
2020年 | 120篇 |
2019年 | 168篇 |
2018年 | 192篇 |
2017年 | 132篇 |
2016年 | 174篇 |
2015年 | 181篇 |
2014年 | 257篇 |
2013年 | 347篇 |
2012年 | 493篇 |
2011年 | 523篇 |
2010年 | 279篇 |
2009年 | 258篇 |
2008年 | 431篇 |
2007年 | 441篇 |
2006年 | 395篇 |
2005年 | 439篇 |
2004年 | 410篇 |
2003年 | 329篇 |
2002年 | 333篇 |
2001年 | 44篇 |
2000年 | 25篇 |
1999年 | 42篇 |
1998年 | 73篇 |
1997年 | 64篇 |
1996年 | 61篇 |
1995年 | 45篇 |
1994年 | 38篇 |
1993年 | 28篇 |
1992年 | 23篇 |
1991年 | 22篇 |
1990年 | 22篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 20篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 19篇 |
1981年 | 15篇 |
1980年 | 13篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1975年 | 12篇 |
1974年 | 5篇 |
排序方式: 共有7052条查询结果,搜索用时 15 毫秒
51.
John R. Baldwin Barbara A. Phillips Stephen K. Overmyer Naomi Z. Hatfield Prem K. Narang 《Cancer chemotherapy and pharmacology》1992,30(6):433-438
Summary The influence of dexrazoxane on doxorubicin pharmacokinetics was investigated in four dogs using the two treatment sequences of saline/doxorubicin or dexrazoxane/doxorubicin. Intravenous doses of 1.5 mg/kg doxorubicin and 30 mg/kg (the 20-fold multiple) dexrazoxane were given separately, with doxorubicin being injected within 1 min of the dexrazoxane dose. Both doxorubicin and its 13-dihydro metabolite doxorubicinol were quantified in plasma and urine using a validated high-performance liquid chromatographic (HPLC) fluorescence assay. The doxorubicin plasma concentration versus time data were adequately fit by a three-compartment model. The mean half-lives calculated for the fast and slow distributive and terminal elimination phases in the saline/doxorubicin group were 3.0±0.5 and 32.2±12.8 min and 30.0±4.0 h, respectively. The model-predicted plasma concentrations were virtually identical for the saline and dexrazoxane treatment groups. Analysis of variance of the area under the plasma concentration-time curve (AUC0–), terminal elimination rate (Z), systemic clearance (CL
s), and renal clearance (CL
r) for the parent drug showed no statistically significant difference (P<0.05) between the two treatments. Furthermore, the doxorubicinol plasma AUC0– value and the doxorubicinol-to-doxorubicin AUC0– ratio showed no significant difference, demonstrating that dexrazoxane had no effect on the metabolic capacity for formation of the 13-dihydro metabolite. The total urinary excretion measured as parent drug plus doxorubicinol and the metabolite-to-parent ratio in urine were also unaffected by the presence of dexrazoxane. The myelosuppressive effects of doxorubicin as determined by WBC monitoring revealed no apparent difference between the two treatments. In conclusion, these results show that drug exposure was similar for the two treatment arms. No kinetic interaction with dexrazoxane suggests that its coadministration is unlikely to modify the safety and/or efficacy of doxorubicin. 相似文献
52.
Francesca Levi-Schaffer Naomi Riesel Dov Soffer Oded Abramsky Talma Brenner 《Molecular and chemical neuropathology / sponsored by the International Society for Neurochemistry and the World Federation of Neurology and research groups on neurochemistry and cerebrospinal fluid》1991,15(2):173-184
The number and functional reactivity of peritoneal mast cells (MCs) were evaluated in rats with experimental allergic encephalomyelitis (EAE). Cells were counted following staining with toluidine blue and activation was measured by B-hexosaminidase (B-hex) release. The number of detectable MCs and their capacity to release B-hex decreased significantly by 40 and 65%, respectively, as compared with normal controls just prior to the onset of clinical signs. These values returned to normal on clinical recovery. Preliminary data on MC counts performed on histological sections of rat brains with EAE suggested a similar pattern of response, i.e., an early decrease prior to disease onset with subsequent normalization on recovery. In an attempt to modify the course of EAE, rats were treated with the MC stabilizing agent nedocromil or with the MC activating agent, compound 48/80. Nedocromil induced a slight delay in the onset of EAE, but only when administered at the time of EAE induction. Compound 48/80 did not seem to affect the clinical course of the disease. Our results suggest that MCs are involved in the pathogenesis of EAE and may contribute to the induction of the disease rather than to the effector phase and its clinical expression. 相似文献
53.
Eleni Petridou Freda E. Alexander Dimitrios Trichopoulos Katharine Revinthi Nick Dessypris Naomi Wray Stavros Haidas Dimitrios Koliouskas Helen Kosmidis Fani Piperopoulou Fotini Tzortzatou 《Cancer causes & control : CCC》1997,8(2):239-245
A total of 872 children aged up to 14 years, who were diagnosed withleukemia in Greece during the decade 1980-89, were allocated by place ofresidence to the 601 administrative districts of the country. Evaluation ofspatial clustering was done using the Potthoff-Whittinghill method, whichvalidly assesses heterogeneity of leukemia risk among districts with variableexpected numbers of cases. There was highly significant evidence for spatialclustering occurring particularly among children living in urban and, to alesser extent, semi-urban areas. The evidence was stronger for childrenyounger than 10 years old, applied also to children in different five-yearage groups, and persisted when cases of acute lymphoblastic leukemia wereanalyzed separately. These findings provide support to the hypothesis thatlocalized environmental exposures could contribute to the etiology ofchildhood leukemia, but they cannot distinguish between exposures of physicalor chemical nature, nor can they exclude socially conditioned patterns ofexposure to infectious agents. 相似文献
54.
Sung Yeon Kim Y R Santosh Laxmi Naomi Suzuki Kenichiro Ogura Tadashi Watabe Michael W Duffel Shinya Shibutani 《Drug metabolism and disposition》2005,33(11):1673-1678
Tamoxifen (TAM) is used as the standard endocrine therapy for breast cancer patients and as a chemopreventive agent for women at high risk for this disease. Unfortunately, treatment of TAM increases the incidence of endometrial cancer; this may be due to the genotoxic damage induced by TAM metabolites. Formation of TAM-DNA adducts in rat liver correlates with the development of hepatocarcinoma. TAM-DNA adducts are proposed to be formed through O-sulfonation and/or O-acetylation of alpha-hydroxylated TAM and its metabolites. However, the role of O-sulfonation and O-acetylation in the formation of TAM-DNA adducts has not been extensively investigated. Rat or human hydroxysteroid sulfotransferases (HST), acetyltransferases, and liver cytosol were incubated with calf thymus DNA, alpha-OHTAM, and either 3'-phosphoadenosine 5'-phosphosulfate (PAPS) or acetyl coenzyme A (acetyl-CoA) as a cofactor and analyzed for TAM-DNA adduct formation, using 32P postlableling/polyacrylamide gel electrophoresis analysis. TAM-DNA adduct was formed when PAPS, not acetyl-CoA, was used. No TAM-DNA adducts were produced using human N-acetyltransferase I and II. HST antibody inhibited approximately 90% of TAM-DNA adduct formation generated by the cytosol or HST, suggesting that HST is primarily involved in the formation of TAM-DNA adducts. The formation of TAM-DNA adducts with rat liver cytosol and HST was much higher than that of human liver cytosol and HST. Our results indicate that TAM-DNA adducts are formed via O-sulfonation, not O-acetylation, of alpha-hydroxylated TAM and its metabolites. 相似文献
55.
Naomi Morita Hiroyuki Kusuhara Yoshitane Nozaki Hitoshi Endou Yuichi Sugiyama 《Drug metabolism and disposition》2005,33(8):1151-1157
Rat organic anion transporter 2 (rOat2, Slc22a7) is a sinusoidal multispecific organic anion transporter in the liver. The role of rOat2 in the hepatic uptake of drugs has not been thoroughly investigated yet. rOat2 substrates include nonsteroidal anti-inflammatory drugs, such as ketoprofen, indomethacin, and salicylate. In the present study, the uptake of ketoprofen, indomethacin, and salicylate by freshly isolated rat hepatocytes was characterized. The uptake of ketoprofen, indomethacin, and salicylate by hepatocytes was sodium-independent, and the rank order of their uptake activities was indomethacin > ketoprofen > salicylate. Kinetic analysis based on Akaike's Information Criterion suggested that the uptake of ketoprofen and indomethacin by hepatocytes consists of two saturable components and one nonsaturable one. The K(m) and V(max) values for the high- and low-affinity components for ketoprofen uptake were 0.84 and 97 microM and 35 and 1800 pmol/min/mg protein, respectively, whereas those for indomethacin were 1.1 and 140 microM and 130 and 16,000 pmol/min/mg protein, respectively. The K(m) values of the high-affinity component were similar to those for rOat2 (3.3 and 0.37 microM for ketoprofen and indomethacin, respectively). The uptake of ketoprofen by hepatocytes was significantly inhibited by probenecid and rOat2 inhibitors (indocyanine green, indomethacin, glibenclamide, and salicylate). Other inhibitors of rOatps (taurocholate and pravastatin) and rOat3 (pravastatin and p-aminohippurate) had a slight effect, but digoxin had no effect. These results suggest that rOat2 accounts partly for the hepatic uptake of ketoprofen and, presumably, indomethacin as a high-affinity site and that other transporters, such as rOatps, but not rOatp2, and rOat3, are also involved. 相似文献
56.
57.
Proton beam therapy for hepatocellular carcinoma: a retrospective review of 162 patients. 总被引:4,自引:0,他引:4
Toshiya Chiba Koichi Tokuuye Yasushi Matsuzaki Shinji Sugahara Yoshimichi Chuganji Kenji Kagei Junichi Shoda Masaharu Hata Masato Abei Hiroshi Igaki Naomi Tanaka Yasuyuki Akine 《Clinical cancer research》2005,11(10):3799-3805
PURPOSE: We present results of patients with hepatocellular carcinoma (HCC) treated with proton beam therapy. EXPERIMENTAL DESIGN: We reviewed 162 patients having 192 HCCs treated from November 1985 to July 1998 by proton beam therapy with or without transarterial embolization and percutaneous ethanol injection. The patients in the present series were considered unsuitable for surgery for various reasons, including hepatic dysfunction, multiple tumors, recurrence after surgical resection, and concomitant illnesses. The median total dose of proton irradiation was 72 Gy in 16 fractions over 29 days. RESULTS: The overall survival rate for all of the 162 patients was 23.5% at 5 years. The local control rate at 5 years was 86.9% for all 192 tumors among the 162 patients. The degree of impairment of hepatic functions attributable to coexisting liver cirrhosis and the number of tumors in the liver significantly affected patient survival. For 50 patients having least impaired hepatic functions and a solitary tumor, the survival rate at 5 years was 53.5%. The patients had very few acute reactions to treatments and a few late sequelae during and after the treatments. CONCLUSIONS: Proton beam therapy for patients with HCC is effective, safe, well tolerable, and repeatable. It is the useful treatment mode for either cure or palliation for patients with HCC irrespective of tumor size, tumor location in the liver, insufficient feeding of the tumor with arteries, presence of vascular invasion, impaired hepatic functions, and coexisting intercurrent diseases. 相似文献
58.
Continuous exposure to dibromoacetic acid delays pubertal development and compromises sperm quality in the rat. 总被引:1,自引:0,他引:1
Gary R Klinefelter Lillian F Strader Juan D Suarez Naomi L Roberts Jerome M Goldman Ashley S Murr 《Toxicological sciences》2004,81(2):419-429
Previously our work on the haloacid by-products of drinking water disinfection focused on adult exposures. Herein we evaluate the consequence of continuous exposure to dibromoacetic acid (DBA) via drinking water through reproductive development into adulthood. An initial study in which offspring were exposed from gestation day (GD) 15 through adulthood revealed significant delays in preputial separation and vaginal opening, dose-related decreases in the fertility of cauda epididymal sperm, and dose-related diminutions in the sperm membrane protein SP22. Subsequent studies consisted of groups in which exposure ceased on postnatal day 21 (PND 21) versus adulthood. For each exposure, animals were evaluated after puberty (PND 56) as well as at adulthood (PND 120). Exposure to 4, 40, or 400 ppm DBA from GD 15 through PND 21 failed to result in any significant reproductive alterations. By contrast, continuous exposure until adulthood resulted in dose-related alterations consistent with those observed in the dose-finding study. Preputial separation and vaginal opening were delayed 4 and 3 days in males and females exposed to 400 ppm (76.3 mg/kg) DBA. This was associated with increased responsiveness of both the testis and ovary to hCG ex vivo; hCG-stimulated testosterone production by testicular parenchyma on PND 56 was increased at 4 ppm (0.6 mg/kg) DBA and higher. Finally, the quality of proximal cauda epididymal sperm was compromised by continuous exposure to DBA. The sperm membrane proteome was altered in a dose-related manner with SP22, and one of its charged variants, diminished at 40 ppm (3.6 mg/kg) DBA and higher. As more sensitive endpoints are evaluated, lower effect levels can be attributed to haloacid exposure. We are now extending our evaluations to epidemiology studies designed to evaluate sperm quality in men exposed to varying levels of disinfection by-products. 相似文献
59.
Nakagata N 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》2007,129(5):343-348
60.
Meijie Tian Adam T. Cheuk Jun S. Wei Abdalla Abdelmaksoud Hsien-Chao Chou David Milewski Michael C. Kelly Young K. Song Christopher M. Dower Nan Li Haiying Qin Yong Yean Kim Jerry T. Wu Xinyu Wen Mehdi Benzaoui Katherine E. Masih Xiaolin Wu Zhongmei Zhang Sherif Badr Naomi Taylor Brad St. Croix Mitchell Ho Javed Khan 《The Journal of clinical investigation》2022,132(16)