全文获取类型
收费全文 | 2367篇 |
免费 | 89篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 60篇 |
妇产科学 | 7篇 |
基础医学 | 380篇 |
口腔科学 | 65篇 |
临床医学 | 175篇 |
内科学 | 607篇 |
皮肤病学 | 15篇 |
神经病学 | 205篇 |
特种医学 | 50篇 |
外科学 | 333篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 64篇 |
眼科学 | 118篇 |
药学 | 172篇 |
中国医学 | 13篇 |
肿瘤学 | 172篇 |
出版年
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 10篇 |
2019年 | 16篇 |
2018年 | 15篇 |
2017年 | 22篇 |
2016年 | 31篇 |
2015年 | 28篇 |
2014年 | 44篇 |
2013年 | 30篇 |
2012年 | 93篇 |
2011年 | 138篇 |
2010年 | 62篇 |
2009年 | 67篇 |
2008年 | 150篇 |
2007年 | 163篇 |
2006年 | 201篇 |
2005年 | 168篇 |
2004年 | 180篇 |
2003年 | 178篇 |
2002年 | 190篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 32篇 |
1998年 | 40篇 |
1997年 | 33篇 |
1996年 | 26篇 |
1995年 | 32篇 |
1994年 | 46篇 |
1993年 | 30篇 |
1992年 | 23篇 |
1991年 | 22篇 |
1990年 | 24篇 |
1989年 | 30篇 |
1988年 | 25篇 |
1987年 | 22篇 |
1986年 | 20篇 |
1985年 | 8篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 13篇 |
1979年 | 11篇 |
1978年 | 18篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 8篇 |
排序方式: 共有2463条查询结果,搜索用时 859 毫秒
91.
Tetsuro Tanaka M.D. Tetsuya Shimazaki M.D. Isao Kusakawa M.D. Masaaki Ogihara M.D. Teruo Honda M.D. Masao Katayama M.D. Katsuyuki Miyasaka M.D. 《Pediatrics international》1990,32(4):365-372
The breathing pattern in children with asthma was studied, using respiratory inductive plethysmography. The subjects were 31 children with mild to moderate asthma (15 males, 16 females; aged 6∼15 years, average 11 years). The respiratory rate was 25.5±10.7/min. (mean ± S.D.) during asthma attacks and 18.4 ± 5.0/min. between attacks with a significant increase during attacks (P < 0.001). The expiratory time was 1.774 ± 0.833 second during attacks, and 2.125 ± 0.602 seconds between attacks. The expiratory time to total respiratory time ratio (TE /TTOT ) was 0.631 ± 0.056 during attacks and 0.608 ± 0.035 between attacks. Thus there was a slight prolongation at the time of attack, but the difference was not significant. The tidal volume was increased slightly during mild and moderate attacks. VT /TI (mean inspiratory flow) was increased during attacks. The respiratory pattern was thoracic during attacks and changed to the abdominal pattern with improvement. 相似文献
92.
Osamu Doi Takashi Kiyama Akio Sato Teruo Okafuji Atsuo Konohana Fumitake Kurosaka Kazuhito Yamada Yasuko Okamoto 《Pediatric surgery international》1995,10(5-6):332-334
Barium enema (B-enema) has been the standard method for hydrostatic reduction of intussusception, although recently air enema has been used due to the lower risk when perforation occurs. Recently, we have administered a small dose of iopamidol during enema reduction (I-enema) in children with intussusception. From November 1989 to December 1993, we treated 50 children with intussusception at Kiyama Hospital. Barium was used in the first half of the period, and iopamidol in the second half. Reduction was successful in 22 of 24 patients with barium (92%) and 23 of 26 with iopamidol (88%); 25 children had the ileocolic type and 25 the ileoileocolic (-cecal) type of intussusception. Operations were carried out in 3 patients from each group. I-enema avoids some of the drawbacks of barium and air enemas. It is a new method of enema reduction, as a contrast medium is injected first. It is possible to obtain a good image of the advanced portion with a small dose of contrast medium, which is important for treatment. For institutions performing B-enemas, I-enemas can be performed easily with the same equipment and technique. It causes less contamination upon leakage than a B-enema, and also has less influence on the intestinal membrane with very few risks if perforation occurs. Better images are obtained than with air. A large dose of contrast medium is not needed, thereby reducing medical expenses to a minimum. Iopamidol can be used safely for enema reduction of intussusception with an expected high success rate. 相似文献
93.
Teruo Iwasaki Kiyoko Shinkai Mutsuko Mukai Kiyoko Yoshioka Yoshitaka Fujii Kazuya Nakahara Hikaru Matsuda Hitoshi Akedo 《International journal of cancer. Journal international du cancer》1995,63(2):282-287
The relationship between cell cycle and experimental metastasis of tumor cells in vivo has been investigated, but it remains to be elucidated which step of metastasis, or whether tumor-cell invasion in particular, depends on cell cycle. We previously reported an in vitro cell-monolayer invasion (transcellular migration) assay system, in which the invasive capacity of tumor cells is measured by counting tumor cells penetrating beneath a cultured mesothelial cell monolayer after tumor-cell seeding. Using our invasion assay system, the relationship between invasive capacity and cell-cycle distribution of MMI cells, a highly invasive clone of rat ascites hepatoma AH130, was investigated. Invasive capacity of aphidicolin- or hydroxyurea-synchronized tumor cells enriched in G1/S—early S-phase cells was about 2 to 6 times higher than that of asynchronous cells. According to time-course experiments to examine the relationship between invasive capacity and the size of fraction of cells in each phase after release from an aphidicolin or a nocodazole block, it was suggested that MMI cells are most invasive in G1/S-S phase. Phagokinetic assay using colloidal gold particles showed that one possible reason for the enhanced invasiveness might be the increased cell motility in such phases, as suggested by the in vitro invasion assay. 相似文献
94.
Masao Maeyama M.D. Teruo Kagami M.D. Isao Miyakawa M.D. Toshimitsu Tooya M.D. Noriyoshi Kawasaki M.D. Teruo Iwamasa M.D. 《Gynecologic oncology》1983,16(3):405-413
A clinicopathological study of a 42-year-old female with pure gonadal dysgenesis and dysgerminoma was made. At the age of 29, the patient with primary amenorrhea had been evaluated clinically and cytogenetically. (1) The results of cytogenetic studies were X-chromatin positive and revealed a karyotype in peripheral blood leukocytes of 46,XX. (2) Laboratory studies indicated hypergonadotropic hypogonadism and no response of the gonads to the human menopausal gonadotropin stumulation test. (3) At laparotomy, the gonads were streak-like. Pathological examinations of biopsy specimens from both gonads revealed dense, fibrous connective tissue resembling ovarian stroma and no primary follicles. Eleven years after the laparotomy, the patient complained of lower abdominal distention and severe pain, and laparotomy then revealed a 15 × 17-cm right solid adnexal mass occupying the pelvic cavity. The histological diagnosis of tissues from the partially removed tumor was pure dysgerminoma. Second-look operation after Linac X-ray irradiation showed complete remission of the residual tumor. Insofar as we are aware, the present patient represents the first case of dysgerminoma which occurred in the dysgenetic gonads of a phenotypic female with normal 46,XX sex-chromosomal constitutions in peripheral blood leukocytes and the skin fibroblasts although a possibility exists that mosaicism was possibly present but undetected, particularly since the streak gonads were not analyzed chromosomally. 相似文献
95.
Kawamoto T Ogawa M Kishimoto T Uchida Y Kato K Kawamoto A Yamashita T 《Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases》2002,76(12):1030-1034
After an inspection tour to farms and abattoirs in Australia and New Zealand, three Japanese persons simultaneously developed febrile illnesses in Japan. They generally had slight fever and general fatigue, followed by thrombocytopenia and hepatic dysfunction. However, no respiratory symptoms were observed. In one of the cases, severe thrombocytopenia (1.3 x 10(4)/microliter) and high fever up to 40 degrees C were observed. These clinical symptoms were compatible with Q fever. All of the cases showed four hold-elevations of IgM and IgG against Coxiella burnetii phase II between acute and convalescent sera by a serological test. C. burentii-DNA was also detected in the serum of one patient. Minocycline was highly effective in all cases. This report illustrates the typical clinical courses of acute Q fever. 相似文献
96.
PURPOSE: To understand the mechanism of corneal ulceration by characterizing the intracellular signaling pathways that regulate collagen degradation by corneal fibroblasts cultured in three-dimensional type I collagen gels. Specifically, the potential roles of protein kinase C (PKC) and protein kinase A (PKA) in collagen degradation were investigated. METHODS: Rabbit corneal fibroblasts were cultured in three-dimensional type I collagen gels for 24 hours in the presence of plasminogen and in the absence or presence of activators or inhibitors of PKC or PKA. Degradation of collagen fibrils was then evaluated by measurement of released hydroxyproline, and the production of matrix metalloproteinases (MMPs) was assessed by gelatin zymography and immunoblot analysis. RESULTS: The PKC activator phorbol 12-myristate 13-acetate (PMA) increased the extent of collagen degradation by corneal fibroblasts in a dose-dependent manner, with the maximal effect apparent at a concentration of 0.1 microM. The inactive analog 4alpha-PMA had no effect on collagen degradation. The PKC inhibitor H-7 reduced the extent of collagen degradation by corneal fibroblasts in the absence or presence of PMA. Phorbol 12-myristate 13-acetate also increased the production of proMMP-1, -3, and -9 by corneal fibroblasts, whereas H-7 inhibited this effect. Neither the PKA activators 8-bromo-cAMP, isobutylmethylxanthine, and forskolin nor the PKA inhibitor HA1004 affected collagen degradation by corneal fibroblasts. CONCLUSION: These results demonstrate that PKC plays an important role in collagen degradation by corneal fibroblasts in three-dimensional type I collagen gels, whereas PKA does not appear to participate in this process. 相似文献
97.
Togashi M Masuda H Kawada T Tanaka M Saida K Ando K Tamura G Magae J 《The Journal of antibiotics》2002,55(4):417-422
The prenyl-phenol antibiotics ascochlorin-related compounds, are known to reduce serum cholesterol and triglyceride, suppress hypertension, and ameliorate types-I and II diabetes. However, little is known about the molecular mechanism for these physiological effects. Here we report that the ascochlorin derivative, 4-O-carboxymethyl ascochlorin (AS-6) acts as a potent activator of the nuclear hormone receptor, PPARgamma, although it does not activate the related receptors, PPARalpha, PPARdelta or RARalpha. AS-6 interacts directly with the PPARgamma molecule in vitro, and induces differentiation of the mouse preadipocyte cell line 3T3-L1. Our results suggest that AS-6 is a partial agonist for PPARgamma with a novel chemical structure. 相似文献
98.
Esumi Y Suzuki Y Itoh Y Uramoto M Kimura K Goto M Yoshihama M Ichikawa T 《The Journal of antibiotics》2002,55(3):296-300
The structure of propeptin, a new inhibitor of prolyl endopeptidase isolated from Microbispora sp. SNA-115, was determined. FAB/MS, Edman degradation and amino acid analysis revealed propeptin to be a cyclic polypeptide consisting of 19 common L-amino acids. By FAB/MS and protein chemical methods, the primary sequence of propeptin was determined to be Gly1-Tyr-Pro-Trp-Trp-Asp-Tyr-Arg-Asp9-Leu-Phe-Gly-Gly-His-Thr-Phe-Ile-Ser-Pro19, which cyclizes between the beta-carboxyl group of Asp9 and the a-amino group of Gly1. 相似文献
99.
Effect of gentamicin on pharmacokinetics of lysozyme in rats: interaction between megalin substrates in the kidney 总被引:1,自引:0,他引:1
Nagai J Katsube T Murakami T Takano M 《The Journal of pharmacy and pharmacology》2002,54(11):1491-1496
To investigate the pharmacokinetic interaction between substrates of megalin, a 600-kDa endocytic receptor abundantly expressed in the renal proximal tubules, we examined the effect of gentamicin infusion on the pharmacokinetics of fluorescein isothiocyanate (FITC)-lysozyme in rats. Infusion of gentamicin did not affect the plasma concentration-time profile of FITC-lysozyme. On the other hand, gentamicin significantly decreased the accumulation of FITC-lysozyme in the renal cortex and medulla, whereas the accumulation in the renal papilla, liver, brain and lung was not changed. Urinary excretion of FITC-lysozyme was increased by gentamicin, whereas there was no change in the biliary excretion of FITC-lysozyme or its degradation products. Gentamicin infusion had little influence on the ATP content in the renal cortex and urinary excretion of glucose, indicating that nephrotoxicity is not induced by short-term infusion of gentamicin. These findings suggest that lysozyme and gentamicin interact with each other in their reabsorption processes in the renal proximal tubules, probably by competing for their binding to megalin expressed in the apical membrane of the renal proximal tubules. 相似文献
100.
Chen DF Zhang SX Kozuka M Sun QZ Feng J Wang Q Mukainaka T Nobukuni Y Tokuda H Nishino H Wang HK Morris-Natschke SL Lee KH 《Journal of natural products》2002,65(9):1242-1245
Two new lignans, interiotherins C (1) and D (2), together with the known compounds interiorin (3), heteroclitin F (4), neokadsuranin (5), heteroclitin D (6), kadsurin (7), gomisin A (8), schisandrin C (9), interiotherin A (10), angeloylgomisin R (11), gomisin G (12), interiotherin B (13), and gomisin C (14), were isolated from the stems of Kadsura interior. The structures and stereochemistries of the new compounds were determined from mass, CD, and NMR spectral data. Fourteen neolignans were screened as potential antitumor promoters by examining their ability to inhibit Epstein-Barr virus early antigen (EBV-EA) activation (induced by 12-O-tetradecanoylphorbol-13-acetate) in Raji cells. Neokadsuranin (5) and schisandrin C (9) were the most potent compounds. These data suggest that some neolignans might be valuable antitumor promoters or chemopreventors. 相似文献