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   13202篇
  免费   694篇
  国内免费   95篇
耳鼻咽喉   63篇
儿科学   200篇
妇产科学   87篇
基础医学   1546篇
口腔科学   229篇
临床医学   826篇
内科学   3321篇
皮肤病学   248篇
神经病学   1193篇
特种医学   810篇
外科学   2254篇
综合类   67篇
预防医学   434篇
眼科学   256篇
药学   846篇
中国医学   49篇
肿瘤学   1562篇
  2023年   76篇
  2022年   129篇
  2021年   352篇
  2020年   183篇
  2019年   254篇
  2018年   283篇
  2017年   272篇
  2016年   326篇
  2015年   334篇
  2014年   449篇
  2013年   528篇
  2012年   815篇
  2011年   926篇
  2010年   544篇
  2009年   459篇
  2008年   756篇
  2007年   828篇
  2006年   814篇
  2005年   874篇
  2004年   787篇
  2003年   799篇
  2002年   820篇
  2001年   193篇
  2000年   151篇
  1999年   203篇
  1998年   219篇
  1997年   160篇
  1996年   174篇
  1995年   145篇
  1994年   131篇
  1993年   119篇
  1992年   126篇
  1991年   90篇
  1990年   82篇
  1989年   74篇
  1988年   49篇
  1987年   40篇
  1986年   46篇
  1985年   60篇
  1984年   45篇
  1983年   33篇
  1982年   34篇
  1981年   25篇
  1980年   27篇
  1979年   14篇
  1978年   15篇
  1977年   10篇
  1975年   14篇
  1974年   18篇
  1973年   11篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Sentinel lymph node biopsy (SLNB) is a widely accepted standard procedure for patients with clinically localized melanoma. Melanoma prevalence and Clark's subtype differ between Asians and Caucasians. Here, we evaluated our experience on SLNB for cutaneous melanoma in a Japanese population. SLNB was performed for patients with melanoma between July 2000 and June 2014. We retrospectively analyzed 102 patients regarding association of clinicopathological features with sentinel lymph node (SLN) status, melanoma‐specific survival (MSS) and disease‐free survival (DFS). A positive SLN was significantly associated with primary Breslow thickness. Compared with 43 patients with negative SLN, 59 patients with positive SLN had significantly shorter MSS (5‐year survival rate, 94.3% vs 63.2%; = 0.0002) and DFS (5‐year survival rate, 92.7% vs 63.4%; = 0.0004). According to our subgroup analyses, nine patients with positive non‐SLN had significantly shorter MSS compared with 32 patients with negative non‐SLN (5‐year survival rate, 32.4% vs 68.5%; = 0.0273). The survival of 51 Japanese patients with acral lentiginous melanoma (ALM) was not inferior to the survival of patients with other Clark's subtype. Breslow thickness is an important factor for both MSS and DFS, and the status of SLN is the most predictive prognostic factor in Japanese patients with clinically localized melanomas, as in case of Caucasians. Features of ALM may be different between Asians and Caucasians.  相似文献   
2.
miRNA‐221 (miR‐221) is known to be abnormally expressed in many human cancers. The serum levels of miR‐221 have been reported as a tumor marker for malignant melanoma (MM). We hypothesized that the hair shaft miR‐221 levels may be increased in patients with MM. We therefore assessed the possibility that hair shaft miR‐221 levels could be a marker for MM. The hair shaft miR‐221 levels were significantly higher in patients with MM than controls. The rates of increased hair shaft miR‐221 levels above the cut‐off value were comparable to those of serum 5‐S‐CD, which is a tumor marker commonly used for MM. Measurements of the hair shaft miR‐221 levels could have potential clinical value in the detection of MM. This is the first report investigating the hair shaft levels of an miRNA in patients with MM. Our investigations offer new insight into the relationship between miR‐221 and MM, and may provide a new, non‐invasive way to screen for melanoma.  相似文献   
3.
Even for patients with multiple pancreaticoduodenal aneurysms, successful treatment with noninvasive operative procedures can be employed, if intraoperative devices are considered. A 73‐year‐old man, without any symptoms, was admitted to our hospital and had computed tomography (CT) scanning to examine his liver for hepatitis C virus (HCV). Selective superior mesenteric artery (SMA) angiography confirmed multiple aneurysms in the anterior inferior pancreaticoduodenal artery (AIPDA), one aneurysm in the posterior inferior mesenteric artery (PIPDA), and another in the occluded celiac trunk, all with severe calcification. All of the aneurysms were thought to communicate with each other. With the celiac artery occlusion, the right hepatic artery (RHA) was revealed to be supplied by collateral arteries from the aneurysms in the AIPDA, and the left hepatic artery was shown to be supplied by collaterals from the left gastric artery. Intraoperative Doppler echography, at the time of the clamping of both IPDAs, demonstrated a marked decrease of blood velocity in all aneurysms (before clamping, >50 cm/s; after, <10 cm/s), although loss of pulsation and a marked decrease of flow in the RHA were inevitable. Therefore, each of these two IPDAs were ligated on the proximal side to the aneurysm, thus preserving the blood flow of the pancreas head fed by the PIPDA; bypass grafting from the AIPDA to the RHA, using the great saphenous vein, was done at the same time. After the creation of an anastomosis, the hepatic venous oxygen saturation (ShvO2) increased from 38% (at the time of ligation of the IPDAs) to 57% under ventilation. The patient's postoperative clinical course was uneventful. We describe and discuss our successful noninvasive operative management of multiple pancreaticoduodenal aneurysms, done while monitoring the blood flow and ShvO2, with some consideration of the literature.  相似文献   
4.
5.
To form the human body and maintain the integrity of its complex tissues, individual cells need to hold tightly to each other. The desmosome is the major type of intercellular adhesive junction, and has desmoglein (Dsg), a cadherin type cell-cell adhesion molecule, as a transmembrane component. Dsg is now known to be targeted in autoimmune diseases, infectious diseases, as well as inherited diseases. Patients with pemphigus, an autoimmune blistering disease of the skin and mucous membrane, have IgG autoantibodies directed against Dsg1 and Dsg3. A subset of patients with pemphigus have Dsg1/Dsg4 crossreacting IgG autoantibodies. Exfoliative toxins produced by Staphylococcal aureus, which causes Staphylococcal Scalded Skin Syndrome (SSSS) and bullous impetigo, specifically digest Dsg1. A subset of patients with SSSS develop a low titer of anti-Dsg1 IgG autoantibodies. A mutation in DSG1 gene causes striate palmoplantar keratoderma and a mutation in DSG4 gene causes inherited hypotrichosis. It is not clear why so many diseases are clustered in desmogleins, but there must be a reason for this. Studies on desmogleins will provide an important framework to understand the mysteries between autoimmunity and infection.  相似文献   
6.
R Kaji  A J Sumner 《Neurology》1987,37(3):410-418
Generators of median short-latency somatosensory evoked potentials were studied with three orthodiagonal pairs of bipolar electrodes. N11 was attributed to the dorsal root and dorsal column volleys. N13 had at least two subcomponents, generator dipoles of which are directed horizontally (N13a) and axially (N13b). N13a was generated in the lower cervical cord. N13b (bipolar) and P14 far-field (noncephalic reference) appeared to originate in the cuneate nucleus or spinocerebellar tracts as well as in the medial lemniscus. Bipolar recordings were useful in localizing cervical cord lesions, which was impossible in conventional monopolar recordings.  相似文献   
7.
Post-thoracotomy wound pain in 11 patients who underwent thoracic operation was controlled by intercostal nerve block with alcohol and thoracic epidural anesthesia. The intercostal nerve block was performed just before the closure of the thoracotomy wound. Epidural anesthesia was employed from the 1st to 5th post operative day. This method alleviated post-thoracotomy pain and obviated postoperative pulmonary complication in all patients in early post operative periods. In late post operative periods after discharge, intercostal nerve block could maintain excellent analgesia in 9 of 11 patients, only 2 patients required analgesic drugs or re-block of the intercostal nerve. Thus, intercostal nerve block with alcohol is an effective and simple option to control recalcitrant post-thoracotomy wound pain in thoracic surgery.  相似文献   
8.
Humoral hypercalcemia of malignancy (HHM) in neoplastic syndrome has been most commonly reported in squamous cell carcinoma. Gallbladder carcinoma with HHM is uncommon. In this report, we describe a male case of gallbladder carcinoma with marked hypercalcemia and a high level of serum parathyroid hormone-related peptide (PTHrP). An immunohistochemical examination using PTHrP was also positive.  相似文献   
9.
The purpose of our study is to evaluate whether the hamstring tendons can regrow after harvesting for anterior cruciate ligament (ACL) reconstruction and whether the regenerate tissue can be histologically characterized as tendinous. Eleven of the patients (eight female and three male; mean age, 23 years; range 17–37 years) consented to participate in this study. One year after the ACL reconstruction, surgical biopsy was done. Regeneration of the tendon was detected macroscopically in 9 of the 11 patients. Histologically and immunohistochemically, the regenerated tendons closely resembled normal ones. The results of this study show the hamstring tendons can regenerate after harvesting for the ACL reconstruction.  相似文献   
10.
OBJECTIVE: The aim of this study was to evaluate the relationship between the degree of conversion (DC) of composites and the light intensity using LED-curing units and also to determine the amount of exposure required to achieve optimal curing. METHOD: The light outputs of light-curing units and the depths of cure of composites exposed to these units were determined using the methods outlined in modified ISO standards, ISO/TS10650 and ISO 4049, respectively. The distributions of DC in composites were investigated by IR spectra of microareas obtained at various depths from the irradiated surface of thin specimens cut out from the cured composites. IR spectra were measured using a Fourier transform infrared spectrometer equipped with a microscopic unit. DC was calculated from the changes in the amount of C=C double bonds in the IR spectra. RESULTS: The light intensity at various depths through the cured composite was calculated from the attenuation coefficient of each material, obtained from the linear relationship between the depth of cure and the logarithm of the amount of exposure, which is defined as the product of the irradiance and irradiation time. There was a third or fourth order regression relationship between DC and the logarithm of total light energy at a particular depth. SIGNIFICANCE: The minimum light energy required to produce a saturated DC was about 1000 s mW/cm2.  相似文献   
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