全文获取类型
收费全文 | 6118篇 |
免费 | 268篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 57篇 |
妇产科学 | 131篇 |
基础医学 | 810篇 |
口腔科学 | 89篇 |
临床医学 | 489篇 |
内科学 | 1355篇 |
皮肤病学 | 92篇 |
神经病学 | 474篇 |
特种医学 | 414篇 |
外科学 | 846篇 |
综合类 | 19篇 |
预防医学 | 177篇 |
眼科学 | 62篇 |
药学 | 664篇 |
中国医学 | 93篇 |
肿瘤学 | 623篇 |
出版年
2023年 | 44篇 |
2022年 | 142篇 |
2021年 | 215篇 |
2020年 | 99篇 |
2019年 | 149篇 |
2018年 | 156篇 |
2017年 | 141篇 |
2016年 | 191篇 |
2015年 | 249篇 |
2014年 | 291篇 |
2013年 | 342篇 |
2012年 | 525篇 |
2011年 | 520篇 |
2010年 | 350篇 |
2009年 | 233篇 |
2008年 | 397篇 |
2007年 | 363篇 |
2006年 | 304篇 |
2005年 | 289篇 |
2004年 | 251篇 |
2003年 | 206篇 |
2002年 | 155篇 |
2001年 | 137篇 |
2000年 | 141篇 |
1999年 | 104篇 |
1998年 | 49篇 |
1997年 | 36篇 |
1996年 | 30篇 |
1995年 | 25篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 28篇 |
1991年 | 33篇 |
1990年 | 28篇 |
1989年 | 27篇 |
1988年 | 22篇 |
1987年 | 24篇 |
1986年 | 15篇 |
1985年 | 20篇 |
1984年 | 12篇 |
1983年 | 11篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1969年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有6467条查询结果,搜索用时 0 毫秒
991.
992.
Kulik LM Carr BI Mulcahy MF Lewandowski RJ Atassi B Ryu RK Sato KT Benson A Nemcek AA Gates VL Abecassis M Omary RA Salem R 《Hepatology (Baltimore, Md.)》2008,47(1):71-81
This study was undertaken to present data from a phase 2 study in which patients with unresectable hepatocellular carcinoma (HCC) with and without portal vein thrombosis underwent radioembolization with Yttrium ((90)Y) microspheres. Patients treated were stratified by Okuda, Child-Pugh, baseline bilirubin, tumor burden, Eastern Cooperative Oncology Group (ECOG), presence of cirrhosis and portal vein thrombosis (PVT) (none, branch, and main). Clinical and biochemical data were obtained at baseline and at 4-week intervals following treatment for up to 6 months. Tumor response was obtained using computed tomography (CT). Patients were followed for survival. One hundred eight patients were treated during the study period. Thirty-seven (34%) patients had PVT, 12 (32%) of which involved the main PV. The cumulative dose for those with and without PVT was 139.7 Gy and 131.9 Gy, respectively. The partial response rate using world Health Organization (WHO) criteria was 42.2%. Using European Association for the Study of the Liver (EASL), the response rate was 70%. Kaplan-Meier survival varied depending on location of PVT and presence of cirrhosis. The adverse event (AE) rates were highest in patients with main PVT and cirrhosis. There were no cases of radiation pneumonitis. Conclusion: The use of minimally embolic (90)Y glass microspheres to treat patients with HCC complicated by branch/lobar PVT may be clinically indicated and appears to have a favorable toxicity profile. Further investigation is warranted in patients with main PVT. 相似文献
993.
994.
Kim HK Choi YH Choi JS Choi SU Kim YS Lee KR Kim YK Ryu SY 《Archives of pharmacal research》2008,31(10):1225-1229
A new stilbenoid (1) was isolated from the root extract of Polygonum multiflorum together with eight known constituents (2∼9). The chemical structure of 1 was established as the 6″-O-monogalloyl ester of (E)-2,3,4′,5-β-tetrahydroxystilbene-2-β-D-glucopyranoside based on physicochemical and spectroscopic analyses, particularly
by NMR spectroscopic data, i.e., COSY, HMQC and HMBC. Compound 1 weakly inhibited acetylcholinesterase in vitro. 相似文献
995.
The goal of this study was to determine the effects of tobacco compounds on gene expression in a human fetal lung cell line (WI38). In the present study, we investigated the effects of tobacco compounds (nicotine, benzo(a)pyrene (B(a)P), and 2-Naphthylamine) on gene expression profiles in human fetal fibroblasts using cDNA microarray and real-time PCR. WI38 cells were cultured in Eagle's minimum essential medium (MEM) supplemented with 10% fetal bovine serum, 2% 200 mM L-glutamine, and a 2% penicillin and streptomycin solution. Tissue culture flasks (T-25 cm(2)) containing confluent lung fibroblasts were incubated at 37 degrees C for 24 h with 5 mL of medium supplemented with 10 microM of a tobacco compound (nicotine, B(a)P, or 2-Naphthylamine). The gene expression profiles for the W138 cells varied depending on the tobacco compound. The cDNA microarray analysis revealed that apoptosis-related genes such as DNASE2, MADD, MST1, NME3, RARG, TNFRSF1A, BAD, and DFFB genes were down-regulated in tobacco compound-treated WI38 cells. We also observed significant increases in Arnt gene expression by real-time PCR in tobacco compound-treated WI38 cells. Tobacco compounds can affect apoptosis, immunity, and growth in WI38 cells. A microarray-based genomic survey is a high-throughput approach for the evaluation of gene expression in cell lines treated with tobacco compounds. 相似文献
996.
Ahn HK Choi JS Han JY Kim MH Chung JH Ryu HM Kim MY Yang JH Koong MK Nava-Ocampo AA Koren G 《Human & experimental toxicology》2008,27(4):307-313
To evaluate whether periconceptional exposure to oral contraceptives (OCs) increased adverse pregnancy outcomes, 136 pregnant women taking OCs within the periconceptional period were identified at the Korean Motherisk Program. Of them, 120 pregnant women accepted to participate in their study and were followed up until completion of the pregnancy. A control group of 240 age- and gravidity-matched pregnant women exposed to non-teratogen drugs for at least 1 month before pregnancy was also included. The median gestational age at delivery was 39.1 (27.0-41.0) weeks in the exposed group and 39.3 (27.4-42.0) weeks in the control group (P = 0.19). In the exposed group, 7.1% of babies were born with low birth weight versus 2.6% in the control group (P = 0.068). The number of preterm deliveries or babies born large for gestational age did not differ between the two groups. In the exposed group, the rate of birth defects was 3.2% (n = 3/99) versus 3.6% (n = 7/193) in the control group (P = 1.0). There were 15 women who took high doses of progesterone (emergency contraception) and no adverse fetal outcomes were observed. In conclusion, periconceptional exposure to OCs does not appear to increase the risk for adverse pregnancy outcomes. 相似文献
997.
Ryu H Jin MK Kim SY Choi HK Kang SU Kang DW Lee J Pearce LV Pavlyukovets VA Morgan MA Tran R Toth A Lundberg DJ Blumberg PM 《Journal of medicinal chemistry》2008,51(1):57-67
Previously, we reported the thiourea antagonists 2a and 2b as potent and high affinity TRPV1 antagonists. For further optimization of the lead compounds, a series of their amide and alpha-substituted amide surrogates were investigated and novel chiral N-(2-benzyl-3-pivaloyloxypropyl) 2-[4-(methylsulfonylamino)phenyl]propionamide analogues were characterized as potent and stereospecific rTRPV1 antagonists. In particular, compounds 72 and 73 displayed high binding affinities, with K i values of 4.12 and 1.83 nM and potent antagonism with K i values of 0.58 and 5.2 nM, respectively, in rTRPV1/CHO cells. These values are comparable or more potent than those of 5-iodoRTX under the same assay conditions. A distinctive binding model that includes two hydrophobic pockets is proposed for this series of compounds based on docking studies of 57 and 72 with a homology model of the TM3/4 region of TRPV1. 相似文献
998.
Park H Bahn YJ Jung SK Jeong DG Lee SH Seo I Yoon TS Kim SJ Ryu SE 《Journal of medicinal chemistry》2008,51(18):5533-5541
Cdc25 phosphatases have been considered as attractive drug targets for anticancer therapy because of the correlation of their overexpression with a wide variety of cancers. We have been able to identify five novel Cdc25 phosphatase inhibitors with micromolar activity by means of a computer-aided drug design protocol involving the homology modeling of Cdc25A and the virtual screening with the automated AutoDock program implementing the effects of ligand solvation in the scoring function. Because the newly discovered inhibitors are structurally diverse and reveal a significant potency with IC 50 values lower than 10 microM, they can be considered for further development by structure-activity relationship studies or de novo design methods. The differences in binding modes of the identified inhibitors in the active sites of Cdc25A and B are discussed in detail. 相似文献
999.
Lee E Kim HJ Im JY Kim J Park H Ryu JY Lee J Shim KA Jung KK Han SY Lee BM Kim SH Kim HS 《The Journal of toxicological sciences》2008,33(3):299-306
This study examined the deleterious effects of di(n-butyl) phthalate (DBP) on the male reproductive organs in hypothyroid rats. Hypothyroidism was induced in prepubertal male rats (28 days of age) by an intraperitonial (i.p.) injection of 10 mg/kg/day propylthiouracil (PTU) for 30 days. DBP (100 and 500 mg/kg/day) was administered by oral gavages to the intact or hypothyroid rats for 30 days. The body weight of the PTU-treated rats was significantly lower than the control group. The total triiodothyronine (T3) and thyroxine (T4) serum level was lower, and the thyroid-stimulating hormone (TSH) level was higher in the hypothyroid rats than in the control rats. The DBP treatment rats showed significantly lower testes, epididymides, seminal vesicles, and ventral prostate weights than the untreated rats. The hypothyroid rats had significantly higher thyroid weights and lower adrenal glands weights than the control rats. The histomorphological examination showed diffused Leydig cells hyperplasias and germ cells loss in the DBP (500 mg/kg)-treated rats, whereas these effects were mild in the DBP-treated hypothyroid rats. The serum levels of monobutyl phthalate (MBP) were significantly lower in PTU-induced hypothyroid rats than in the DBP-treated rats. This data suggests that the hypothyroid status might offer some protection from male reproductive organ toxicity caused by a disturbance in the metabolic activation of the parent compound, DBP. 相似文献
1000.
Helicobacter pylori is one of the main causes of atrophic gastritis and gastric carcinogenesis. Gastritis can also occur in the absence of H. pylori as a result of bile reflux suggesting the eradication of H. pylori by bile acids. However, the bile salts are unable to eradicate H. pylori due to their low solubility and instability at acidic pH. This study examined the effect of a highly soluble and acid stable ursodeoxycholic acid (UDCA) formula on H. pylori-induced atrophic gastritis. The H. pylori infection decreased the body weight, mitochondrial membrane potential and ATP level in vivo. Surprisingly, H. pylori-induced expression of malate dehydrogenase (MDH), a key enzyme in the tricarboxylic acid cycle, at both the protein and mRNA levels. However, the UDCA formula repressed MDH expression and increased the membrane potential thereby increasing the ATP level and body weight in vivo. Moreover, UDCA scavenged the reactive oxygen species (ROS), increased the membrane potential, and inhibited apoptosis in AGS cells exposed to H2O2 in vitro through the mitochondria-mediated pathway. Taken together, UDCA decreases the MDH and ROS levels, which can prevent apoptosis in H. pylori-induced gastritis. 相似文献