全文获取类型
收费全文 | 8223篇 |
免费 | 524篇 |
国内免费 | 173篇 |
专业分类
耳鼻咽喉 | 165篇 |
儿科学 | 99篇 |
妇产科学 | 113篇 |
基础医学 | 1396篇 |
口腔科学 | 109篇 |
临床医学 | 600篇 |
内科学 | 1896篇 |
皮肤病学 | 258篇 |
神经病学 | 621篇 |
特种医学 | 547篇 |
外科学 | 1042篇 |
综合类 | 35篇 |
一般理论 | 2篇 |
预防医学 | 251篇 |
眼科学 | 327篇 |
药学 | 696篇 |
中国医学 | 91篇 |
肿瘤学 | 672篇 |
出版年
2024年 | 3篇 |
2023年 | 61篇 |
2022年 | 222篇 |
2021年 | 333篇 |
2020年 | 149篇 |
2019年 | 231篇 |
2018年 | 314篇 |
2017年 | 209篇 |
2016年 | 417篇 |
2015年 | 491篇 |
2014年 | 513篇 |
2013年 | 613篇 |
2012年 | 862篇 |
2011年 | 817篇 |
2010年 | 478篇 |
2009年 | 399篇 |
2008年 | 488篇 |
2007年 | 475篇 |
2006年 | 357篇 |
2005年 | 360篇 |
2004年 | 283篇 |
2003年 | 219篇 |
2002年 | 181篇 |
2001年 | 91篇 |
2000年 | 74篇 |
1999年 | 53篇 |
1998年 | 39篇 |
1997年 | 19篇 |
1996年 | 16篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 19篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有8920条查询结果,搜索用时 15 毫秒
71.
You Sun Kim Min Jeong Na Byong Duk Ye Jae Hee Cheon Jong Pil Im Joo Sung Kim Group The CONNECT Study 《Gut and liver》2022,16(6):995
The clinical course and prognosis of patients with elderly-onset Crohn’s disease (CD) remain unclear. This study aimed to analyze the clinical characteristics and outcomes of elderly-onset CD patients from the prospective CONNECT study cohort, a nationwide, multicenter cohort study of patients with CD in Korea. Among a total of 1,175 patients in the prospective CONNECT study cohort, 94 patients (Montreal age A3) were included and divided into two groups according to their age at diagnosis: the elderly-onset group (diagnosed with CD after 60 years of age, n=26, 67.54±6.7 years) and late adult-onset group (diagnosed as CD at age 41 to 59 years, n=68, 48.06±5.1 years). The elderly-onset group was characterized by a lower Crohn’s disease activity index at diagnosis (124.89±101.9 vs 189.55±128.6, p=0.023) and higher rates of previous anti-tuberculosis treatment (34.6% vs 4.4%, p<0.001) than the late adult-onset group. Compared with the late adult-onset group, the elderly-onset group showed a significantly less use of thiopurines (p=0.003), as well as anti-tumor necrosis factor-alpha agents (p=0.047). Additionally, the elderly-onset group was less likely to require bowel resection than the late adult-onset group (p=0.067), suggesting that elderly-onset CD patients in Korea appear to have more favorable clinical outcomes than late adult-onset CD patients. (Gut Liver 2022;16:-1000) 相似文献
72.
So Yoon Choi Sujin Choi Ben Kang Byung-Ho Choe Yeoun Joo Lee Jae Hong Park Yu Bin Kim Jae Young Kim Kunsong Lee Kyung Jae Lee Ki Soo Kang Yoo Min Lee Hyun Jin Kim Yunkoo Kang Hyo-Jeong Jang Dae Yong Yi Suk Jin Hong You Jin Choi Jeana Hong Soon Chul Kim 《Journal of Korean medical science》2022,37(37)
BackgroundStudies on how the coronavirus pandemic has affected pediatric inflammatory bowel disease (PIBD) are lacking. We aimed to investigate the trends in epidemiology, characteristics, initial management, and short-term outcomes of PIBD in South Korea over the recent three years including the era of coronavirus disease 2019 (COVID-19).MethodsThis multicenter study retrospectively investigated temporal trends in the epidemiology of PIBD in Korea. Annual occurrences, disease phenotypes, and initial management at diagnosis were analyzed from January 2018 to June 2021.ResultsA total of 486 patients from 17 institutions were included in this epidemiological evaluation. Analysis of the occurrence trend confirmed a significant increase in PIBD, regardless of the COVID-19 pandemic. In Crohn’s disease, patients with post-coronavirus outbreaks had significantly higher fecal calprotectin levels than those with previous onset (1,339.4 ± 717.04 vs. 1,595.5 ± 703.94, P = 0.001). Patients with post-coronavirus-onset ulcerative colitis had significantly higher Pediatric Ulcerative Colitis Activity Index scores than those with previous outbreaks (48 ± 17 vs. 36 ± 15, P = 0.004). In the initial treatment of Crohn’s disease, the use of 5-aminosalicylic acid (5-ASA) and steroids significantly decreased (P = 0.006 and 0.001, respectively), and enteral nutrition and the use of infliximab increased significantly (P = 0.045 and 0.009, respectively). There was a significant increase in azathioprine use during the initial treatment of ulcerative colitis (P = 0.020).ConclusionRegardless of the COVID-19 pandemic, the number of patients with PIBD is increasing significantly annually in Korea. The initial management trends for PIBD have also changed. More research is needed to establish appropriate treatment guidelines considering the epidemiological and clinical characteristics of Korean PIBD. 相似文献
73.
Sung Ran Kim Hyeon Jeong Kang Hye Rin Jeong Su Yeon Jang Jae Eun Lee Da Eun Kim Hae Ry Lee Min Hee Cho Ji Yun Noh Hee Jin Cheong Woo Joo Kim Joon Young Song 《Journal of Korean medical science》2022,37(35)
The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to have high infectivity and is more likely to evade vaccine immunity. However, booster vaccination is expected to strengthen cross-reactive immunity, thereby increasing the vaccine effectiveness (VE). This study aimed to evaluate the relative VE of the 3-dose (booster) vaccination compared with the 2-dose primary series vaccination in healthcare workers during omicron variant-dominant periods. During the omicron-dominant period from February 1, 2022 to February 28, 2022, a 1:1 matched case-control study was conducted. Healthcare workers with positive SARS-CoV-2 test results were classified as positive cases, whereas those with negative results served as controls. Compared with the 2-dose primary series vaccination, booster vaccination with mRNA vaccine showed moderate VE (53.1%). However, in multivariate analysis including the time elapsed after vaccination, the significant VE disappeared, reflecting the impact of recent vaccination rather than the third dose itself. 相似文献
74.
Gyoohwan Jung Seung Min Lee Sang Won So Sehwan Kim Seong Chan Kim Ohbin Kwon Hyunjae Song Min Joo Choi Sung Yong Cho 《Journal of Korean medical science》2022,37(38)
BackgroundIt is essential to understand the mechanism of the various causes of laser fiber damage and an ideal method of reducing endoscope damage induced by laser emission in multiple sites. This study classified the different patterns of laser fiber degradation according to laser settings and analyzed the role of cavitation bubbles to find a desirable way of minimizing endoscope damage.MethodsA total of 118 laser fibers were analyzed after 1-,3-, and 5-min laser emission to artificial stones under the settings of 1 J-10 Hz, 1 J-20 Hz, 1 J-30 Hz, and 2 J-10 Hz. Every 3 cm from the fiber tip was marked and examined with a digital microscope and a high-speed camera. The images of the fibers and the movement of cavitation bubbles were taken with a distance of 1 to 5 mm from the gel.ResultsSeven types of fiber damage (charring, limited and extensive peeled-off, bumpy, whitish plaque, crack, and break-off) coincided during laser emission. Damages rapidly increased with emission time > 3 minutes regardless of the laser settings. The damaged lengths covered 5 mm on average, and the fibers at 5-min emission were significantly shorter than others. The fiber durability of 1J-10Hz setting was better than other settings after 3-min laser emission. Backward movement of the cavitation bubbles was found at the 1-mm distance from the gel, and the damaged lengths were longer than the diameters of the cavitation bubbles because of their proximal movement.ConclusionThe damage patterns of the laser fiber tips were classified into seven types. The heat damage around the surface of the laser fiber can be increased according to the high-energy or high-frequency laser setting, a short distance to the stone, a short distance from the tips of flexible ureteroscopes, no cutting laser fiber procedures, and the inappropriate use of irrigation fluid or laser fiber jacket. 相似文献
75.
Eliel Nham Joon Young Song Ji Yun Noh Hee Jin Cheong Woo Joo Kim 《Journal of Korean medical science》2022,37(47)
Since its first emergence in late 2019, severe acute respiratory syndrome coronavirus-2 has claimed more than 6.5 million lives worldwide and continues to infect hundreds of thousands of people daily. To combat this once-in-a-century disaster, several vaccines have been developed at unprecedented speeds. Novel vaccine platforms (messenger ribonucleic acid vaccines and adenoviral vector vaccines) have played a major role in the current pandemic. In Korea, six vaccines, including a domestically developed recombinant vaccine, have been approved. As in other countries, vaccines have been proven to be safe and highly effective in Korea. However, rare serious adverse events and breakthrough infections have undermined public trust in the vaccines, even while the benefits of vaccination far outweigh the risks. The rise of the omicron variant and the subsequent increase in excess mortality demonstrated that while vaccines are a key component of the pandemic response, it alone can fail without non-pharmaceutical interventions like masking and social distancing. The pandemic of coronavirus disease has revealed both the strengths and weaknesses of our healthcare system and pandemic preparedness. When the next pandemic arrives, improved risk communication and vaccine development should be prioritized. To enable timely vaccine development, it is essential to make strategic and sufficient investments in vaccine research and development. 相似文献
76.
Woo-gyun Choi Na Ri Choi Eun-Jung Park Byung Joo Kim 《International journal of medical sciences》2022,19(13):1824
Herbal medicines have traditionally been used as an effective digestive medicine. However, compared to the effectiveness of Herbal medicines, the treatment mechanism has not been fully identified. To solve this problem, a system-level treatment mechanism of Jakyakgamcho-Tang (JGT), which is used for the treatment of functional dyspepsia (FD), was identified through a network pharmacology study. The two components, paeoniae radix alba and licorice constituting JGT were analyzed based on broad information on chemical and pharmacological properties, confirming 84 active chemical compounds and 84 FD-related targets. The JGT target confirmed the relationship with the regulation of various biological movements as follows: cellular behaviors of muscle and cytokine, calcium ion concentration and homeostasis, calcium- and cytokine-mediated signalings, drug, inflammatory response, neuronal cells, oxidative stress and response to chemical. And the target is enriched in variety FD-related signaling as follows: MAPK, Toll-like receptor, NOD-like receptor, PI3K-Akt, Apoptosis and TNF signaling pathway. These data give a new approach to identifying the molecular mechanisms underlying the digestive effect of JGT. 相似文献
77.
5-Fluorouracil (5-FU) remains to be an important chemotherapeutic drug for treating several cancers when targeted therapy is unavailable. Chemoresistance limits the clinical utility of 5-FU, and new strategies are required to overcome the resistance. Reactive oxygen species (ROS) and antioxidants are balanced differently in both normal and cancer cells. Modulating ROS can be one method of overcoming 5-FU resistance. This review summarizes selected compounds and endogenous cellular targets modulating ROS generation to overcome 5-FU resistance. 相似文献
78.
A high-performance liquid chromatography tandem mass spectrometry method is described for the simultaneous determination of mycotoxins, including Ergot alkaloids (EAs), in 3 types of grains. The extraction of 23 mycotoxins was evaluated and performed by using a modified QuEChERS-based sample preparation procedure. The proposed method was fully validated on spiked grain samples (barley, wheat and oat) to assess the linearity, limit of detection (LOD) and limit of quantitation (LOQ), matrix effects, precision and recovery. After validation, this method was applied to 143 samples of various types of 3 grains from the Republic of Korea to survey the level of mycotoxin contamination in Republic of Korean grains. A total of 42 grain samples (29%) were contaminated with at least one of these mycotoxins at levels higher than the LOQ. The results demonstrated that the procedure was suitable for simultaneously determining these mycotoxins in cereals and could be performed for their routine analysis in mycotoxin laboratories. 相似文献
79.
Seung-Hwan Kwon Shi-Xun Ma Hyun-Joong Joo Seok-Yong Lee Choon-Gon Jang 《Biomolecules & therapeutics.》2013,21(6):462-469
Eucommia ulmoides Oliv. Bark (EUE) is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia as well as to promote longevity. In this study, we tested the effects of EUE aqueous extract in graded doses to protect and enhance cognition in scopolamine-induced learning and memory impairments in mice. EUE significantly improved the impairment of short-term or working memory induced by scopolamine in the Y-maze and significantly reversed learning and memory deficits in mice as measured by the passive avoidance and Morris water maze tests. One day after the last trial session of the Morris water maze test (probe trial session), EUE dramatically increased the latency time in the target quadrant in a dose-dependent manner. Furthermore, EUE significantly inhibited acetylcholinesterase (AChE) and thiobarbituric acid reactive substance (TBARS) activities in the hippocampus and frontal cortex in a dose-dependent manner. EUE also markedly increased brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP element binding protein (CREB) in the hippocampus of scopolamine-induced mice. Based on these findings, we suggest that EUE may be useful for the treatment of cognitive deficits, and that the beneficial effects of EUE are mediated, in part, by cholinergic signaling enhancement and/or protection. 相似文献
80.