全文获取类型
收费全文 | 172841篇 |
免费 | 11109篇 |
国内免费 | 1409篇 |
专业分类
耳鼻咽喉 | 2490篇 |
儿科学 | 3233篇 |
妇产科学 | 3967篇 |
基础医学 | 25818篇 |
口腔科学 | 3510篇 |
临床医学 | 16173篇 |
内科学 | 33175篇 |
皮肤病学 | 4728篇 |
神经病学 | 12953篇 |
特种医学 | 8743篇 |
外科学 | 23468篇 |
综合类 | 2236篇 |
现状与发展 | 5篇 |
一般理论 | 84篇 |
预防医学 | 10193篇 |
眼科学 | 4629篇 |
药学 | 14631篇 |
中国医学 | 1720篇 |
肿瘤学 | 13603篇 |
出版年
2023年 | 1063篇 |
2022年 | 2949篇 |
2021年 | 5189篇 |
2020年 | 2689篇 |
2019年 | 3881篇 |
2018年 | 4725篇 |
2017年 | 3504篇 |
2016年 | 4601篇 |
2015年 | 6183篇 |
2014年 | 7585篇 |
2013年 | 9115篇 |
2012年 | 13708篇 |
2011年 | 13332篇 |
2010年 | 7894篇 |
2009年 | 6662篇 |
2008年 | 9970篇 |
2007年 | 9756篇 |
2006年 | 8964篇 |
2005年 | 8502篇 |
2004年 | 7538篇 |
2003年 | 6572篇 |
2002年 | 5749篇 |
2001年 | 4538篇 |
2000年 | 4198篇 |
1999年 | 3386篇 |
1998年 | 1379篇 |
1997年 | 1059篇 |
1996年 | 992篇 |
1995年 | 896篇 |
1994年 | 772篇 |
1993年 | 675篇 |
1992年 | 1617篇 |
1991年 | 1626篇 |
1990年 | 1386篇 |
1989年 | 1281篇 |
1988年 | 1204篇 |
1987年 | 1067篇 |
1986年 | 1033篇 |
1985年 | 901篇 |
1984年 | 663篇 |
1983年 | 587篇 |
1982年 | 410篇 |
1981年 | 386篇 |
1980年 | 357篇 |
1979年 | 545篇 |
1978年 | 427篇 |
1977年 | 414篇 |
1976年 | 353篇 |
1974年 | 369篇 |
1973年 | 339篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jong-Wook Yoo Yoon-Jung Shin Xiaoyang Ma Young-Hoo Son Hyo-Min Jang Chang Kyun Lee Dong-Hyun Kim 《Nutrients》2022,14(10)
Gut microbiota dysbiosis is strongly associated with psychiatric disorders and inflammatory bowel disease (IBD). Herein, we examined whether the fecal microbiota of IBD patients with depression (IBDD) and their gut microbiota culture (iGm) could cause depression and colitis in mice and anti-inflammatory probiotics could mitigate depression in iGm-transplanted or immobilization stress (IS)-exposed mice. Fecal microbiota transplantation (FMT) from IBDD patients, which exhibited Enterobacteriaceae-rich gut microbiota, and its gut microbiota culture (iGm) increased depression-like behaviors in mice. Their treatments heightened the blood lipopolysaccharide (LPS) level and colonic IL-1β and IL-6 expression. However, FMT from healthy volunteers or sulfasalazine treatment alleviated cGm-induced depressive-like behaviors and hippocampal and colonic inflammation in mice. Moreover, oral administration of Lactobacillus plantarum NK151, Bifidobacterium longum NK173, and Bifidobacterium bifidum NK175, which inhibited LPS-induced IL-6 expression in macrophages, alleviated cGm-induced depression-like behaviors, hippocampal NF-κB+Iba1+ cell numbers and IL-1β and IL-6 expression, blood LPS, IL-6, and creatinine levels, and colonic NF-κB+CD11c+ number and IL-1β and IL-6 expression in mice. Treatment with NK151, NK173, or NK175 mitigated immobilization stress (IS)-induced depressive-like behaviors, neuroinflammation, and gut inflammation in mice. NK151, NK173, or NK175 also decreased IS-induced blood LPS, IL-6, and creatinine levels. The transplantation of Enterobacteriaceae-rich gut microbiota can cause depression and colitis, as IS exposure, and anti-inflammatory NK151, NK173, and NK175, may alleviate stress-induced fatigue, depression, and colitis by regulating the expression of proinflammatory and anti-inflammatory cytokines through the suppression of gut bacterial LPS. 相似文献
992.
Despite the positive effects of botulinum neurotoxin (BoNT) injection into the neural arborized area, there is no anatomical evidence in the literature regarding the neural arborization of the supraspinatus muscle. The present study aimed to define the intramuscular neural arborized pattern of the supraspinatus muscle using the modified Sihler’s staining method to facilitate the establishment of safe and effective injection sites in patients with myofascial pain in the supraspinatus muscle. Seventeen supraspinatus muscles from 15 embalmed cadavers were dissected. Precise suprascapular nerve entry locations were also observed. Intramuscular neural arborization was visualized by Sihler’s staining. The supraspinatus muscle was divided into four portions named A, B, C, and D. The nerve entry points were observed in 88.2% (15 of 17 cases) of section B and 76.5% (13 of 17 cases) of section C of the supraspinatus muscle, respectively. The concentration of intramuscular neural arborization was highest in section B of the supraspinatus muscle, which was the center of the supraspinatus muscle. When the clinician performs a trigger point and a BoNT injection into the supraspinatus muscle, injection within the medial 25–75% of the supraspinatus muscle will lead to optimal results when using small amounts of BoNT and prevent undesirable paralysis. 相似文献
993.
Vincent Yi-Fong Su Szu-Wen Ko Yuh-Lih Chang Yueh-Ching Chou Hsin-Chen Lee Kuang-Yao Yang Kun-Ta Chou Chia-Chen Hsu 《Allergy, asthma & immunology research》2022,14(3):314
PurposeCurrent clinical guidelines are unclear regarding the association of cardiovascular medication with the risk of acute exacerbation (AE) in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO).MethodsWe conducted a retrospective cohort study by interrogating the claims database of Taipei Veterans General Hospital. Patients with coexistent fixed airflow limitation and asthma were enrolled as an ACO cohort between 2009 and 2017. Exposure to cardiovascular medications, including angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), non-selective beta-blockers, cardioselective beta-blockers, dihydropyridine (DHP) calcium channel blockers (CCBs), and non-DHP CCBs, in 3-month period each served as time-dependent covariates. Patients receiving a cardiovascular medication ≥ 28 cumulative daily doses were defined as respective cardiovascular medication users. Patients were followed up until December 31, 2018. The primary endpoint was severe AE, defined as hospitalization or emergency department visit for either asthma, COPD, or respiratory failure. The secondary outcome was moderate AE.ResultsThe final study cohort consisted of 582 ACO subjects, with a mean follow-up period of 2.98 years. After adjustment, ARB (hazard ratio [HR], 0.64, 95% confidence interval [CI], 0.44–0.93, P = 0.019), cardioselective beta-blocker (HR, 0.29, 95% CI, 0.11–0.72, P = 0.008) and DHP CCB (HR, 0.66, 95% CI, 0.45–0.97, P = 0.035) therapies were associated with lower risks of severe AE. ARB (HR, 0.42, 95% CI, 0.30–0.62, P < 0.001) and DHP CCB (HR, 0.55, 95% CI, 0.38–0.80, P = 0.002) therapies were associated with lower risks of moderate AE. Cardioselective beta-blockers, ARBs, and DHP CCBs were associated with lower risks of severe AE in frequent exacerbators. ACEI, non-selective beta-blocker, or non-DHP CCB use did not change the risk of severe AE.ConclusionsARB, cardioselective beta-blocker, and DHP CCB therapies may lower the risk of AE in patients with ACO. 相似文献
994.
Seung-Jin Park Yea Eun Kang Jeong-Hwan Kim Jong-Lyul Park Seon-Kyu Kim Seung-Woo Baek In Sun Chu Shinae Yi Seong Eun Lee Young Joo Park Eun-Jae Chung Jin Man Kim Hye Mi Ko Je-Ryong Kim Seung-Nam Jung Ho-Ryun Won Jae Won Chang Bon Seok Koo Seon-Young Kim 《Clinical and experimental otorhinolaryngology》2022,15(2):183
995.
Cheol Park Eun Ok Choi Hyun Hwangbo Hyesook Lee Jin-Woo Jeong Min Ho Han Sung-Kwon Moon Seok Joong Yun Wun-Jae Kim Gi-Young Kim Hye-Jin Hwang Yung Hyun Choi 《Nutrition Research And Practice》2022,16(3):330
BACKGROUND/OBJECTIVESZanthoxylum schinifolium is traditionally used as a spice for cooking in East Asian countries. This study was undertaken to evaluate the anti-proliferative potential of ethanol extracts of Z. schinifolium leaves (EEZS) against human bladder cancer T24 cells.MATERIALS/METHODSSubsequent to measuring the cytotoxicity of EEZS, the anti-cancer activity was measured by assessing apoptosis induction, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP). In addition, we determined the underlying mechanism of EEZS-induced apoptosis through various assays, including Western blot analysis.RESULTSEEZS treatment concentration-dependently inhibited T24 cell survival, which is associated with apoptosis induction. Exposure to EEZS induced the expression of Fas and Fas-ligand, activated caspases, and subsequently resulted to cleavage of poly (ADP-ribose) polymerase. EEZS also enhanced the expression of cytochrome c in the cytoplasm by suppressing MMP, following increase in the ratio of Bax:Bcl-2 expression and truncation of Bid. However, EEZS-mediated growth inhibition and apoptosis were significantly diminished by a pan-caspase inhibitor. Moreover, EEZS inhibited activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway, and the apoptosis-inducing potential of EEZS was promoted in the presence of PI3K/Akt inhibitor. In addition, EEZS enhanced the production of ROS, whereas N-acetyl cysteine (NAC), a ROS scavenger, markedly suppressed growth inhibition and inactivation of the PI3K/Akt signaling pathway induced by EEZS. Furthermore, NAC significantly attenuated the EEZS-induced apoptosis and reduction of cell viability.CONCLUSIONSTaken together, our results indicate that exposure to EEZS exhibits anti-cancer activity in T24 bladder cancer cells through ROS-dependent induction of apoptosis and inactivation of the PI3K/Akt signaling pathway. 相似文献
996.
Hyohun Choi Jang Hoon Lee Hyuk Kyoon Park Eunkyu Lee Myeong Seop Kim Hyeon Jeong Kim Bo Eun Park Hong Nyun Kim Namkyun Kim Se Yong Jang Myung Hwan Bae Dong Heon Yang Hun Sik Park Yongkeun Cho 《Journal of Korean medical science》2022,37(21)
BackgroundIt has been known that the fear of contagion during the coronavirus disease 2019 (COVID-19) creates time delays with subsequent impact on mortality in patients with acute myocardial infarction (AMI). However, difference of time delay and clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI) or non-STEMI between the COVID-19 pandemic and pre-pandemic era has not been fully investigated yet in Korea. The aim of this study was to investigate the impact of COVID-19 pandemic on time delays and clinical outcome in patients with STEMI or non-STEMI compared to the same period years prior.MethodsA total of 598 patients with STEMI (n = 195) or non-STEMI (n = 403) who underwent coronary angiography during the COVID-19 pandemic (February 1 to April 30, 2020) and pre-pandemic era (February 1 to April 30, 2017, 2018, and 2019) were analyzed in this study. Main outcomes were the incidence of time delay, cardiac arrest, and in-hospital death.ResultsThere was 13.5% reduction in the number of patients hospitalized with AMI during the pandemic compared to pre-pandemic era. In patients with STEMI, door to balloon time tended to be longer during the pandemic compared to pre-pandemic era (55.7 ± 12.6 minutes vs. 60.8 ± 13.0 minutes, P = 0.08). There were no significant differences in cardiac arrest (15.6% vs. 10.4%, P = 0.397) and in-hospital mortality (15.6% vs. 10.4%, P = 0.397) between pre-pandemic and the pandemic era. In patients with non-STEMI, symptom to door time was significantly longer (310.0 ± 346.2 minutes vs. 511.5 ± 635.7 minutes, P = 0.038) and the incidence of cardiac arrest (0.9% vs. 3.5%, P = 0.017) and in-hospital mortality (0.3% vs. 2.3%, P = 0.045) was significantly greater during the pandemic compared to pre-pandemic era. Among medications, angiotensin converting enzyme inhibitors/angiotensin type 2 receptor blockers (ACE-I/ARBs) were underused in STEMI (64.6% vs. 45.8%, P = 0.021) and non-STEMI (67.8% vs. 57.0%, P = 0.061) during the pandemic.ConclusionDuring the COVID-19 pandemic, there has been a considerable reduction in hospital admissions for AMI, time delay, and underuse of ACE-I/ARBs for the management of AMI, and this might be closely associated with the excess death in Korea. 相似文献
997.
998.
Tim Du Kelly B. Choi Anada Silva George R. Golding Linda Pelude Romeo Hizon Ghada N. Al-Rawahi James Brooks Blanda Chow Jun C. Collet Jeannette L. Comeau Ian Davis Gerald A. Evans Charles Frenette Guanghong Han Jennie Johnstone Pamela Kibsey Kevin C. Katz Joanne M. Langley Bonita E. Lee Yves Longtin Dominik Mertz Jessica Minion Michelle Science Jocelyn A. Srigley Paula Stagg Kathryn N. Suh Nisha Thampi Alice Wong Susy S. Hota 《Emerging infectious diseases》2022,28(6):1128
We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015–2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015–2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control. 相似文献
999.
Lim YJ Park HS Im KS Lee C Hong J Lee M Kim Dk D Jung JH 《Journal of natural products》2001,64(1):46-53
Ten new polyacetylenic alcohols (1-6, 8-11), along with a known compound, petrocortyne C (7), were isolated from the marine sponge Petrosia sp. The gross structures were established based on NMR and MS data, and the absolute configuration was determined by the modified Mosher's method. These compounds displayed considerable cytotoxicity against a small panel of human solid tumor cell lines. Compounds 1-11 were further evaluated for in vitro inhibitory activity on DNA replication. 相似文献
1000.
T G Kim S Y Kang K K Jung J H Kang E Lee H M Han S H Kim 《Phytotherapy research : PTR》2001,15(8):718-720
The antiviral effects of aqueous extracts of Terminalis chebula Retz., Sanguisorba officinalis L., Rubus coreanus Miq. and Rheum palmatum L. were examined by a cell culture system using a hepatitis B virus (HBV) producing cell line, HepG2 2.2.15. The extracts were assayed for the inhibition of HBV multiplication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells after an 8-day treatment. All extracts decreased the levels of extracellular HBV virion DNA at concentrations ranging from 64 to 128 microg/mL and inhibited the secretion of HBsAg dose dependently. Of the four tested plants, Terminalis chebula exhibited the most prominent anti-HBV activities. 相似文献