全文获取类型
收费全文 | 31177篇 |
免费 | 1525篇 |
国内免费 | 182篇 |
专业分类
耳鼻咽喉 | 332篇 |
儿科学 | 621篇 |
妇产科学 | 447篇 |
基础医学 | 3522篇 |
口腔科学 | 605篇 |
临床医学 | 2098篇 |
内科学 | 8508篇 |
皮肤病学 | 562篇 |
神经病学 | 2292篇 |
特种医学 | 1042篇 |
外科学 | 5844篇 |
综合类 | 77篇 |
预防医学 | 836篇 |
眼科学 | 582篇 |
药学 | 2246篇 |
中国医学 | 58篇 |
肿瘤学 | 3212篇 |
出版年
2023年 | 233篇 |
2022年 | 492篇 |
2021年 | 842篇 |
2020年 | 450篇 |
2019年 | 569篇 |
2018年 | 750篇 |
2017年 | 527篇 |
2016年 | 722篇 |
2015年 | 671篇 |
2014年 | 941篇 |
2013年 | 1129篇 |
2012年 | 1759篇 |
2011年 | 2057篇 |
2010年 | 1107篇 |
2009年 | 1018篇 |
2008年 | 1684篇 |
2007年 | 1708篇 |
2006年 | 1701篇 |
2005年 | 1759篇 |
2004年 | 1829篇 |
2003年 | 1706篇 |
2002年 | 1589篇 |
2001年 | 601篇 |
2000年 | 579篇 |
1999年 | 554篇 |
1998年 | 371篇 |
1997年 | 304篇 |
1996年 | 228篇 |
1995年 | 196篇 |
1994年 | 208篇 |
1993年 | 168篇 |
1992年 | 425篇 |
1991年 | 357篇 |
1990年 | 347篇 |
1989年 | 347篇 |
1988年 | 330篇 |
1987年 | 330篇 |
1986年 | 284篇 |
1985年 | 223篇 |
1984年 | 209篇 |
1983年 | 162篇 |
1982年 | 98篇 |
1980年 | 74篇 |
1979年 | 163篇 |
1978年 | 91篇 |
1977年 | 80篇 |
1975年 | 95篇 |
1972年 | 76篇 |
1971年 | 82篇 |
1969年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Improved high performance liquid chromatography determination of hippuric acid and methylhippuric acid isomers in urine 总被引:1,自引:0,他引:1
Y Takeuchi T Sakai Y Ikeya T Araki K Ushio S Yanagihara 《Sangyō igaku. Japanese journal of industrial health》1986,28(6):455-461
A study was made on the effect of detection wavelength and separation mode of HPLC on determination of urinary hippuric acid (HA) and three isomers of methylhippuric acid (MHA). The interference of other constituents of urine in the determination was effectively decreased by detection at a short wavelength of 227.6 nm. Meta and para MHAs were separated by the addition of beta-cyclodextrine to the mobile phase. Four metabolites were successfully separated from other components of urine by the combination of ODS-silica packed-column and mobile phase (method F). The detection limits were found to be 50 and 5 mg/l for HA and MHAs, respectively. MHAs could not be detected in the non-exposed subjects. Average levels (+/- SD) of HA in non-exposed males and females were 272.2 (+/- 210.8) and 393.0 (+/- 269.8) mg/l, respectively. The urinary levels of HA in females were significantly higher than those in males. 相似文献
102.
Satoshi Yamamoto MD ; Yosinobu Sato MD ; Toru Abo MD ; Katsuyosi Hatakeyama MD 《Wound repair and regeneration》2002,10(4):241-244
Recently, we found CD3-CD4(bright) cells with comparative specificity for normal rat liver. In the current study, we investigated the type and form of both CD3-CD4(bright) cells and CD3-CD4(dull) cells in the rat liver. The surface phenotype of hepatic mononuclear cells in Lewis rats was identified by using monoclonal antibodies including anti-CD4, anti-CD3, and antimacrophage in conjunction with two- or three-color immunofluorescence analysis. CD3-CD4(bright) cells and CD3-CD4(dull) cells were examined morphologically using May-Giemsa staining and scanning electron microscopy. The distribution of CD3-CD4(bright) cells and CD3-CD4(dull) cells 48 hours after intravenous administration of liposome-encapsulated dichloromethylene diphosphate was also investigated. In comparison to CD3-CD4(dull) cells, CD3-CD4(bright) cells were slightly larger macrophages with abundant cytoplasmic granules, being present with comparative specificity for normal rat liver and showing negligible effects by intravenous liposome-encapsulated dichloromethylene diphosphate administration. These data suggest that in normal young rat liver these CD3-CD4(dull) and CD3-CD4(bright) cells may be dendritic cells and Kupffer cells that shift from the liver to the spleen or vice versa. These cells may also be able to locally proliferate in liver or spleen due to changes in the developing liver. 相似文献
103.
M Konishi M Sawaki K Mikasa S Takeuchi K Hamada H Ako M Kunimatsu N Narita 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(11):1420-1424
We conducted a clinical study on respiratory infections complicating bronchial asthma. Transtracheal aspiration (TTA) was performed 37 times in 22 patients. The most frequently isolated organism was H. influenzae. The patients in whom organisms were isolated on TTA had a high incidence of fever and evidence of inflammation. Antimicrobial therapy caused a decrease in indices of inflammation (white blood cell count and ESR), but was less effective against the asthmatic symptoms. Respiratory infection may play a complex role in the clinical picture of bronchial asthma. 相似文献
104.
105.
Crystal-matrix interrelations in brushite and uric acid calculi 总被引:1,自引:0,他引:1
Brushite and uric acid calculi were studied by means of scanning electron microscopy with the partial dissolution method and transmission electron microscopy. Brushite calculi consist of radially oriented columnar crystals which have sheet-like substructure. The organic matrix is identified chiefly at the outside of the crystals but partly included between the substructure. The concentric matrix bands are often dislocated between the neighbouring crystals. Uric acid calculi also consist of radially oriented columnar crystals, and a fine meshwork of the organic matrix is incorporated within the crystals. The concentric matrix layers of different density are angled according to the crystal lattice. These findings indicate that the organic matrix arose from a mucinous surface coat, at least in the radially striated calculi. The crystals continued to grow in this gel-state milieu, either thrusting the matrix aside or incorporating it within the crystals. 相似文献
106.
K Kimura T Kawada K Takeuchi M Ogawa S Aoki S Suzuki 《Nihon eiseigaku zasshi. Japanese journal of hygiene》1989,44(2):567-578
The aims of the present study were to observe the daily habituation to night sleep in a laboratory environment and to make clear the daily and individual sleep variations by using polygraph parameters, including electroencephalography (EEG). Sleep EEG records were obtained from a subject who slept ten successive nights, and from six subjects who each slept one night in the laboratory. The parameters used were as follows: sleep stage %, sleep latency (SL), REM latency (RL), number of stage shifts, subjective sleep, integral EMG, and slope (a) and intersect (b) of a regression equation used to estimate the sleep depth against sleep time. Stage WAKE and SL, slope (a), intersect (b) and the mean depth of sleep were found to become stable from the fifth night. Stage MT, the number of stage shifts, and integral EMG increased significantly from the fifth night and later, showing p less than 0.01, p less than 0.01, and p less than 0.05, respectively. Judging from these findings, the sleep habituation of the subject in the laboratory was completed within the first four nights. Coefficients of variation of sleep stage 2 and stage REM of the ten-nights' EEG were the lowest among all the sleep parameters examined. Almost all the parameters of day-to-day sleep of the subject who slept for ten successive nights in the laboratory showed smaller variations than those of the other six subjects. It may be concluded that the mist effect on sleep could be assessed more precisely by using an individual repeatedly than by using a group of subjects. 相似文献
107.
Hamartoma of the parotid gland: A case report with immunohistochemical and electron microscopic study 总被引:1,自引:0,他引:1
Hitoshi Tsuda Shojiroh Morinaga Kiyoshi Mukai Takashi Nakajima Yukio Shimosato Tsuyoshi Kaneko Satoshi Ebihara 《Virchows Archiv : an international journal of pathology》1987,411(5):473-478
Summary A case of a solid parotid tumour in a 16-year-old boy is presented. Histologically, the tumour demonstrated some peculiar findings. An acinar pattern was predominant although every component seen in the normal salivary gland was present, namely, serous and mucous gland acini, ducts, myoepithelial cells, adipose and lymphoid tissue. Large eosinophilic granules were abundant in the large acinar cell cytoplasm. Immunohistochemically, the tumour demonstrated the proteins which are present in the normal parotid gland, for example, amylase, lactoferrin and lysozyme. Electron microscopic features were quite similar to those of normal parotid tissue except for accumulation of a large number of cytoplasmic granules in the acinar cells. There has been no previous report of a tumour with the same features as seen in this case. Our pathological diagnosis is hamartoma, although the possibility of hyperplasia or neoplasia can not be excluded. 相似文献
108.
K Yamazaki Y Imai H Kurosawa N Fujiwara M Kawada K Matsuo E Ko T Takeuchi 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(11):878-883
A successful case of Norwood operation for a 5-day-old infant with hypoplastic left heart syndrome is reported. Norwood procedure and central shunting with a 4 mm PTFE tube was performed. Cerebral and coronary artery were perfused independently during reconstruction of aorta in order to shorten the time of circulatory arrest. Post operative UCG documented un-obstructive systemic output from the right ventricle, well regulated pulmonary arterial blood flow and widely patent interatrial communication. This baby was discharged the hospital 66 days after surgery. He has been clinically well for six month after the operation. 相似文献
109.
We report on a 66-year-old woman in whom GPi pallidotomy produced progressive and eventually complete relief of hemichorea/ballism (HCB) after a subthalamic hemorrhage. Although choreoballistic movements were unchanged during and immediately after the surgery, the symptoms were gradually improved and consequently abolished by 5 days postoperatively. HCB has never recurred up to the present (9 months follow-up period). This note is the first report describing detailed postsurgical process in HCB relief after pallidotomy. 相似文献
110.
Regeneration of defects in articular cartilage in rat knee joints by CCN2 (connective tissue growth factor). 总被引:7,自引:0,他引:7
Takashi Nishida Satoshi Kubota Shunji Kojima Takuo Kuboki Kyouji Nakao Toshihiro Kushibiki Yasuhiko Tabata Masaharu Takigawa 《Journal of bone and mineral research》2004,19(8):1308-1319
CTGF/CCN2, a hypertrophic chondrocyte-specific gene product, possessed the ability to repair damaged articular cartilage in two animal models, which were experimental osteoarthritis and full-thickness defects of articular cartilage. These findings suggest that CTGF/CCN2 may be useful in regeneration of articular cartilage. INTRODUCTION: Connective tissue growth factor (CTGF)/CCN2 is a unique growth factor that stimulates the proliferation and differentiation, but not hypertrophy, of articular chondrocytes in vitro. The objective of this study was to investigate the therapeutic use of CTGF/CCN2. MATERIALS AND METHODS: The effects of recombinant CTGF/CCN2 (rCTGF/CCN2) on repair of damaged cartilage were evaluated by using both the monoiodoacetic acid (MIA)-induced experimental rat osteoarthritis (OA) model and full-thickness defects of rat articular cartilage in vivo. RESULTS: In the MIA-induced OA model, quantitative real-time RT-PCR assays showed a significant increase in the level of CTGF/CCN2 mRNA, and immunohistochemical analysis and in situ hybridization revealed that the clustered chondrocytes, in which clustering indicates an attempt to repair the damaged cartilage, produced CTGF/CCN2. Therefore, CTGF/CCN2 was suspected to play critical roles in cartilage repair. In fact, a single injection of rCTGF/CCN2 incorporated in gelatin hydrogel (rCTGF/CCN2-hydrogel) into the joint cavity of MIA-induced OA model rats repaired their articular cartilage to the extent that it became histologically similar to normal articular cartilage. Next, to examine the effect of rCTGF/CCN2 on the repair of articular cartilage, we created defects (2 mm in diameter) on the surface of articular cartilage in situ and implanted rCTGF/CCN2-hydrogel or PBS-hydrogel therein with collagen sponge. In the group implanted with rCTGF/CCN2-hydrogel collagen, new cartilage filled the defect 4 weeks postoperatively. In contrast, only soft tissue repair occurred when the PBS-hydrogel collagen was implanted. Consistent with these in vivo effects, rCTGF/CCN2 enhanced type II collagen and aggrecan mRNA expression in mouse bone marrow-derived stromal cells and induced chondrogenesis in vitro. CONCLUSION: These findings suggest the utility of CTGF/CCN2 in the regeneration of articular cartilage. 相似文献