首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5004篇
  免费   299篇
  国内免费   26篇
耳鼻咽喉   43篇
儿科学   90篇
妇产科学   37篇
基础医学   606篇
口腔科学   190篇
临床医学   258篇
内科学   1277篇
皮肤病学   276篇
神经病学   457篇
特种医学   150篇
外科学   904篇
综合类   21篇
预防医学   117篇
眼科学   239篇
药学   275篇
中国医学   7篇
肿瘤学   382篇
  2023年   19篇
  2022年   15篇
  2021年   80篇
  2020年   64篇
  2019年   87篇
  2018年   122篇
  2017年   111篇
  2016年   92篇
  2015年   104篇
  2014年   100篇
  2013年   161篇
  2012年   240篇
  2011年   306篇
  2010年   173篇
  2009年   130篇
  2008年   276篇
  2007年   250篇
  2006年   240篇
  2005年   281篇
  2004年   211篇
  2003年   239篇
  2002年   270篇
  2001年   158篇
  2000年   159篇
  1999年   155篇
  1998年   75篇
  1997年   47篇
  1996年   43篇
  1995年   54篇
  1994年   41篇
  1993年   42篇
  1992年   80篇
  1991年   80篇
  1990年   75篇
  1989年   80篇
  1988年   77篇
  1987年   73篇
  1986年   68篇
  1985年   69篇
  1984年   49篇
  1983年   33篇
  1982年   25篇
  1981年   23篇
  1980年   25篇
  1979年   38篇
  1978年   36篇
  1977年   30篇
  1976年   14篇
  1975年   16篇
  1974年   17篇
排序方式: 共有5329条查询结果,搜索用时 31 毫秒
1.
2.
A Bochdalek hernia (BH) is a congenital abnormality with incomplete closure of the diaphragm. It is usually manifested in infants but rarely in adults. Here, we report an adult patient with gastric volvulus and giant BH that were safely repaired by endoscopic reduction and elective laparoscopic surgery, respectively. A 79-year-old woman presented with left upper abdominal pain but no history of trauma. CT revealed a giant BH with gastric volvulus. After emergency endoscopic reduction of the volvulus, elective laparoscopic repair of the BH was performed. The 8 × 8-cm defect was repaired with interrupted nonabsorbable sutures and a mesh. The patient's postoperative course was uneventful, and no complications or recurrence were observed in the 6 months that followed.  相似文献   
3.

Background

The Tama-REgistry of Acute endovascular Thrombectomy (TREAT) is a multicenter registry of endovascular thrombectomy in the Tama area of Tokyo. The objective of this study was to confirm the real-world status of 2 paradigms of transportation.

Methods

This was a retrospective analysis of data from TREAT. Patients were divided into 2 groups and 2 periods: directly admitted to an endovascular thrombectomy-capable center (ECC; group D)/secondary transfer from a non-ECC (group S), and the first period/the second period. Transfer distance, workflow metrics, and clinical outcomes were analyzed.

Results

A total of 326 patients, including 264 in group D and 62 in group S, were analyzed. The median distance from the onset-to-ECC was 3.62km for group D and 7.87km for group S (P < .001). The median onset-to-needle (OTN) time was longer for group S (168 minutes) than group D (138 minutes; P?=?.006). The median onset-to-reperfusion (OTR) time was significantly shorter for group D (247 minutes) than for group S (304 minutes; P?=?.029). With respect to the 2 periods, there was no significant difference in onset-to-puncture time between the 2 groups in the first period (207 minutes versus 243.5 minutes, respectively, P?=?.50), while there was one in the second period (164 minutes versus 246.5 minutes, respectively, P?=?.02).

Conclusions

This region-wide registry study showed longer OTN and OTR times, with no improvement of the time course over time in patients transported via non-ECCs. These results should be used to create a regional medical policy for the management of acute ischemic stroke.  相似文献   
4.
Daily exposure to sunlight is known to affect the structure and function of the epidermal basement membrane (BM), as well as epidermal differentiation and epidermal barrier function. The aim of this study is to clarify whether the inhibition of BM‐degrading enzymes such as heparanase and matrix metalloproteinase 9 (MMP‐9) can improve the epidermal barrier function of facial skin, which is exposed to the sun on a daily basis. 1‐(2‐hydroxyethyl)‐2‐imidazolidinone (HEI) was synthesized as an inhibitor of both heparanase and MMP‐9. HEI inhibited not only the BM damage at the DEJ but also epidermal proliferation, differentiation, water contents and transepidermal water loss abnormalities resulting from ultraviolet B (UVB). This was determined in this study by the use of UVB‐induced human cultured skins as compared with the control without HEI. Moreover, topical application of HEI improved epidermal barrier function by increasing water content and decreasing transepidermal water loss in daily sun‐exposed facial skin as compared with non‐treated skins. These results suggest that the inhibition of both heparanase and MMP‐9 is an effective way to care for regularly sun‐exposed facial skin by protecting the BM from damage.  相似文献   
5.
6.
We report a case of a manicurist who developed an allergic skin reaction to acrylates, manifested by itchy erythema, papules, vesicles and fissures on her hands, fingertips, forearm and eyelids. Patch tests showed positive reactions to three nail products used: ethylene glycol dimethacrylate, 2‐hydroxyethyl methacrylate, ethyl acrylate and 2‐hydroxyethyl acrylate in (meth)acrylate series. By using gel nail products, our patient became sensitized to 2‐hydroxyethyl methacrylate. We assume that this had been the trigger, leading to the occurrence of cross‐reactions between numerous acrylates including ethylene glycol dimethacrylate, ethyl acrylate and 2‐hydroxyethyl acrylate. When handling nail products, it is necessary to prevent airway sensitization, contact sensitization and cross‐reaction between various acrylates.  相似文献   
7.
Manabu Fujimoto  Jun Asai  Yoshihide Asano  Takayuki Ishii  Yohei Iwata  Tamihiro Kawakami  Masanari Kodera  Masatoshi Abe  Masahiro Amano  Ryuta Ikegami  Taiki Isei  Zenzo Isogai  Takaaki Ito  Yuji Inoue  Ryokichi Irisawa  Masaki Ohtsuka  Yoichi Omoto  Hiroshi Kato  Takafumi Kadono  Sakae Kaneko  Hiroyuki Kanoh  Masakazu Kawaguchi  Ryuichi Kukino  Takeshi Kono  Monji Koga  Keisuke Sakai  Eiichi Sakurai  Yasuko Sarayama  Yoichi Shintani  Miki Tanioka  Hideaki Tanizaki  Jun Tsujita  Naotaka Doi  Takeshi Nakanishi  Akira Hashimoto  Minoru Hasegawa  Masahiro Hayashi  Kuninori Hirosaki  Hideki Fujita  Hiroshi Fujiwara  Takeo Maekawa  Koma Matsuo  Naoki Madokoro  Sei-Ichiro Motegi  Hiroshi Yatsushiro  Osamu Yamasaki  Yuichiro Yoshino  Andres James LE Pavoux  Takao Tachibana  Hironobu Ihn  Japanese Dermatological Association Guidelines 《The Journal of dermatology》2020,47(10):1071-1109
The Japanese Dermatological Association prepared guidelines focused on the treatment of skin ulcers associated with connective tissue disease/vasculitis practical in clinical settings of dermatological care. Skin ulcers associated with connective tissue diseases or vasculitis occur on the background of a wide variety of diseases including, typically, systemic sclerosis but also systemic lupus erythematosus (SLE), dermatomyositis, rheumatoid arthritis (RA), various vasculitides and antiphospholipid antibody syndrome (APS). Therefore, in preparing the present guidelines, we considered diagnostic/therapeutic approaches appropriate for each of these disorders to be necessary and developed algorithms and clinical questions for systemic sclerosis, SLE, dermatomyositis, RA, vasculitis and APS.  相似文献   
8.
Marinesco bodies (MBs) are spherical nuclear inclusions found in pigmented neurons of the substantia nigra. Although MBs are abundant in senescent brains, how they are related to aging processes remains unclear. Here, we performed a morphometric analysis of midbrain pigmented neurons to identify the possible influence of MBs on nuclear size. The transected area of the nucleus (nuclear area) was larger in the presence of MBs and was correlated with the area of MB (MB area) in all tested brains. The MB-associated nuclear enlargement was significant even after MB areas were subtracted from nuclear areas. Moreover, higher MB immunoreactivity of p62 was detected in the nucleoplasm of the enlarged MB-associated nuclei. This study on human brains is the first quantitative approach demonstrating MB-associated nuclear enlargement and progressive accumulation of small nucleoplasmic materials. Although cellular hypertrophy is usually considered to be an indication of the upregulation of cellular function, this might not always be the case. These findings suggest that an age-related decline of ubiquitin-proteasome and autophagy system activity and stagnation of undegradable materials are one of the candidate mechanisms to explain the age-related decline of neural activity in the substantia nigra.  相似文献   
9.
Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).  相似文献   

10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号