全文获取类型
收费全文 | 72464篇 |
免费 | 7262篇 |
国内免费 | 4458篇 |
专业分类
耳鼻咽喉 | 688篇 |
儿科学 | 991篇 |
妇产科学 | 663篇 |
基础医学 | 8230篇 |
口腔科学 | 1155篇 |
临床医学 | 8614篇 |
内科学 | 10538篇 |
皮肤病学 | 1251篇 |
神经病学 | 3699篇 |
特种医学 | 3162篇 |
外国民族医学 | 14篇 |
外科学 | 6779篇 |
综合类 | 12279篇 |
现状与发展 | 15篇 |
一般理论 | 5篇 |
预防医学 | 5753篇 |
眼科学 | 1574篇 |
药学 | 8295篇 |
54篇 | |
中国医学 | 5052篇 |
肿瘤学 | 5373篇 |
出版年
2024年 | 335篇 |
2023年 | 1148篇 |
2022年 | 2733篇 |
2021年 | 3568篇 |
2020年 | 2562篇 |
2019年 | 2358篇 |
2018年 | 2477篇 |
2017年 | 2424篇 |
2016年 | 2501篇 |
2015年 | 3601篇 |
2014年 | 4280篇 |
2013年 | 4521篇 |
2012年 | 6201篇 |
2011年 | 6514篇 |
2010年 | 4596篇 |
2009年 | 3648篇 |
2008年 | 4247篇 |
2007年 | 4166篇 |
2006年 | 3748篇 |
2005年 | 3395篇 |
2004年 | 2578篇 |
2003年 | 2630篇 |
2002年 | 2254篇 |
2001年 | 1741篇 |
2000年 | 1329篇 |
1999年 | 977篇 |
1998年 | 581篇 |
1997年 | 538篇 |
1996年 | 400篇 |
1995年 | 335篇 |
1994年 | 305篇 |
1993年 | 202篇 |
1992年 | 220篇 |
1991年 | 204篇 |
1990年 | 172篇 |
1989年 | 136篇 |
1988年 | 104篇 |
1987年 | 88篇 |
1986年 | 81篇 |
1985年 | 49篇 |
1984年 | 30篇 |
1983年 | 16篇 |
1982年 | 14篇 |
1981年 | 23篇 |
1980年 | 17篇 |
1979年 | 37篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1972年 | 7篇 |
1969年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Hyun Jong Choi Jong Ho Moon Yun Nah Lee Hyun Su Kim Ji Su Ha Tae Hoon Lee Sang‐Woo Cha Young Deok Cho Sang‐Heum Park 《Digestive endoscopy》2015,27(7):772-775
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS. 相似文献
2.
3.
PNPLA3 gene polymorphism and response to lifestyle modification in patients with nonalcoholic fatty liver disease 下载免费PDF全文
4.
Toidi Adekambi Chris C. Ibegbu Stephanie Cagle Ameeta S. Kalokhe Yun F. Wang Yijuan Hu Cheryl L. Day Susan M. Ray Jyothi Rengarajan 《The Journal of clinical investigation》2015,125(5):1827-1838
BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection.METHODS. Using polychromatic flow cytometry, we evaluated the expression of immune activation markers on Mtb-specific CD4+ T cells from individuals with asymptomatic latent Mtb infection (LTBI) and ATB as well as from ATB patients undergoing anti-TB treatment.RESULTS. Frequencies of Mtb-specific IFN-γ+CD4+ T cells that expressed immune activation markers CD38 and HLA-DR as well as intracellular proliferation marker Ki-67 were substantially higher in subjects with ATB compared with those with LTBI. These markers accurately classified ATB and LTBI status, with cutoff values of 18%, 60%, and 5% for CD38+IFN-γ+, HLA-DR+IFN-γ+, and Ki-67+IFN-γ+, respectively, with 100% specificity and greater than 96% sensitivity. These markers also distinguished individuals with untreated ATB from those who had successfully completed anti-TB treatment and correlated with decreasing mycobacterial loads during treatment.CONCLUSION. We have identified host blood-based biomarkers on Mtb-specific CD4+ T cells that discriminate between ATB and LTBI and provide a set of tools for monitoring treatment response and cure.TRIAL REGISTRATION. Registration is not required for observational studies.FUNDING. This study was funded by Emory University, the NIH, and the Yerkes National Primate Center. 相似文献
5.
6.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
7.
Bryan Mclaughlin JungHwan Yang Woohyun Yoo Bret Shaw Soo Yun Kim Dhavan Shah 《Health communication》2016,31(6):762-771
The growth of online support groups has led to an expression effects paradigm within the health communication literature. Although religious support expression is characterized as a typical subdimension of emotional support, we argue that in the context of a life-threatening illness, the inclusion of a religious component creates a unique communication process. Using data from an online group for women with breast cancer, we test a theoretical expression effects model. Results demonstrate that for breast cancer patients, religious support expression has distinct effects from general emotional support messages, which highlights the need to further theorize expression effects along these lines. 相似文献
8.
9.
Eun-Joo Shin Yunsung Nam Thu-Hien Thi Tu Yong Kwang Lim Myung-Bok Wie Dae-Joong Kim Ji Hoon Jeong Hyoung-Chun Kim 《Archives of toxicology》2016,90(4):937-953
We investigated whether protein kinase C (PKC) is involved in trimethyltin (TMT)-induced neurotoxicity. TMT treatment (2.8 mg/kg, i.p.) significantly increased PKCδ expression out of PKC isozymes (i.e., α, βI, βII, δ, and ?) in the hippocampus of wild-type (WT) mice. Consistently, treatment with TMT resulted in significant increases in cleaved PKCδ expression. Genetic or pharmacological inhibition (PKCδ knockout or rottlerin) was less susceptible to TMT-induced seizures than WT mice. TMT treatment increased glutathione oxidation, lipid peroxidation, protein oxidation, and levels of reactive oxygen species. These effects were more pronounced in the WT mice than in PKCδ knockout mice. In addition, the ability of TMT to induce nuclear translocation of Nrf2, Nrf2 DNA-binding activity, and upregulation of γ-glutamylcysteine ligase was significantly increased in the PKCδ knockout mice and rottlerin (10 or 20 mg/kg, p.o. × 6)-treated WT mice. Furthermore, neuronal degeneration (as shown by nuclear chromatin clumping and TUNEL staining) in WT mice was most pronounced 2 days after TMT. At the same time, TMT-induced inhibition of phosphoinositol 3-kinase (PI3K)/Akt signaling was evident, thereby decreasing phospho-Bad, expression of Bcl-xL and Bcl-2, and the interaction between phospho-Bad and 14-3-3 protein, and increasing Bax expression and caspase-3 cleavage were observed. Rottlerin or PKCδ knockout significantly protected these changes in anti- and pro-apoptotic factors. Importantly, treatment of the PI3K inhibitor LY294002 (0.8 or 1.6 µg, i.c.v.) 4 h before TMT counteracted protective effects (i.e., Nrf-2-dependent glutathione induction and pro-survival phenomenon) of rottlerin. Therefore, our results suggest that down-regulation of PKCδ and up-regulations of Nrf2-dependent glutathione defense mechanism and PI3K/Akt signaling are critical for attenuating TMT neurotoxicity. 相似文献
10.
Three‐Dimensional Echocardiographic Evaluation of Mitral Apparatus during Preload Manipulation in Patients with Hypertrophic Cardiomyopathy 下载免费PDF全文
Hyemoon Chung M.D. Ji Hyun Yoon M.D. Young Won Yoon M.D. Ph.D. Ji Young Chung B.N. Jung‐Joon Cha M.D. Jong‐Youn Kim M.D. Ph.D. Pil‐Ki Min M.D. Ph.D. Byoung‐Kwon Lee M.D. Ph.D. Bum‐Kee Hong M.D. Ph.D. Se‐Joong Rim M.D. Ph.D. Hyuck Moon Kwon M.D. Eui‐Young Choi M.D. Ph.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(8):1261-1269