全文获取类型
收费全文 | 40808篇 |
免费 | 1969篇 |
国内免费 | 193篇 |
专业分类
耳鼻咽喉 | 317篇 |
儿科学 | 772篇 |
妇产科学 | 688篇 |
基础医学 | 5164篇 |
口腔科学 | 1065篇 |
临床医学 | 2752篇 |
内科学 | 10154篇 |
皮肤病学 | 634篇 |
神经病学 | 2893篇 |
特种医学 | 1459篇 |
外科学 | 7570篇 |
综合类 | 183篇 |
预防医学 | 1317篇 |
眼科学 | 456篇 |
药学 | 2945篇 |
中国医学 | 130篇 |
肿瘤学 | 4471篇 |
出版年
2023年 | 211篇 |
2022年 | 402篇 |
2021年 | 732篇 |
2020年 | 414篇 |
2019年 | 569篇 |
2018年 | 723篇 |
2017年 | 573篇 |
2016年 | 652篇 |
2015年 | 716篇 |
2014年 | 944篇 |
2013年 | 1118篇 |
2012年 | 1782篇 |
2011年 | 1883篇 |
2010年 | 1060篇 |
2009年 | 866篇 |
2008年 | 1671篇 |
2007年 | 1803篇 |
2006年 | 1791篇 |
2005年 | 1865篇 |
2004年 | 1857篇 |
2003年 | 1766篇 |
2002年 | 1760篇 |
2001年 | 1677篇 |
2000年 | 1630篇 |
1999年 | 1563篇 |
1998年 | 559篇 |
1997年 | 450篇 |
1996年 | 398篇 |
1995年 | 357篇 |
1994年 | 349篇 |
1993年 | 309篇 |
1992年 | 999篇 |
1991年 | 944篇 |
1990年 | 817篇 |
1989年 | 905篇 |
1988年 | 776篇 |
1987年 | 700篇 |
1986年 | 747篇 |
1985年 | 682篇 |
1984年 | 431篇 |
1983年 | 377篇 |
1982年 | 194篇 |
1981年 | 188篇 |
1979年 | 312篇 |
1978年 | 241篇 |
1977年 | 209篇 |
1975年 | 211篇 |
1974年 | 186篇 |
1973年 | 173篇 |
1971年 | 176篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
M Tanaka E Takeuchi T Watanabe S Tamaki K Tajima T Maseki A Usui Y Hirate M Sawazaki T Abe 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1992,40(1):61-65
There is no definitive surgical procedure for acquired lesions of the tricuspid valve (TV). From Feb, 1978, through March, 1990, the surgical treatment for the organic lesions of TV was performed in 10 patients, repair in 6 and TV replacement in 4. TV was repaired by commissurotomy, annuloplasty or valvuloplasty, or combination of them. When residual significant tricuspid regurgitation (TR) and/or stenosis (TS) was detected by intraoperative pulsed Doppler echocardiography after reparative procedures, TV was replaced. Follow-up periods ranged from 1 to 12 years (mean, 45.3 months). There was no early death, and late death was noted in one patient 32 months after operation. Preoperatively, 7 patients were in NYHA class IV and 3 in class III. Out of survivors, 7 are in class I and 2 in class II because of progression of mitral stenosis or coronary artery disease. Following surgery, the patients exhibited significant decrease in the cardiothoracic ratio (69.3 +/- 7.2 to 56.9 +/- 6.4%; p less than 0.01) and in the mean right atrial pressure (11.4 +/- 3.6 to 8.6 +/- 3.1 mmHg; p less than 0.05). The postoperative right ventriculography showed mild to moderate TR in 3 of 6 patients who underwent TV repair. In conclusion, TV repair could be a reasonable procedure for the organic TV lesions, although careful follow-up is recommended for residual TR. 相似文献
52.
S Sohen P L Romain D M Rothstein T Yamane S Tanaka P Anderson S F Schlossman C Morimoto 《The Journal of rheumatology》1991,18(11):1649-1654
We analyzed the cell surface phenotype of CD8+ cells in both peripheral blood and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Utilizing the monoclonal antibodies anti-CD45RA, anti-CD29 and anti-S6F1-, one can define both suppressor effector (CD45RA+CD29-S6F1-) and killer effector (CD45RA-CD29+S6F1+) cells within the CD8 population. In patients with OA, normal proportions of CD8+CD45RA+, CD8+CD29+ and CD8+S6F1+ cells were found in both peripheral blood and SF. The peripheral blood of patients with RA, in contrast, showed a decreased percentage of CD8+CD45RA+ cells (13.4 +/- 2.6) (p less than 0.05), but a normal percentage of CD8+CD29+ and CD8+S6F1+ cells. In the SF of patients with RA, we observed a more dramatic decrease in CD8+CD45RA+ suppressor effector cells (6.4 +/- 5.0) (p less than 0.001), a significant increase in killer effector cells as measured by both CD8 + CD29+ (35.5 +/- 9.9) (p less than 0.001) and CD8 + S6F1+ cells (28.2 +/- 11.4) (p less than 0.01). These changes may contribute to the immunologic abnormalities previously noted in this disease and may provide some insight into the pathophysiologic mechanisms of RA. 相似文献
53.
H Akama MD H Tanaka MD T Yoshida MD H Kameda MD S Kawai MD 《International journal of clinical practice》1994,48(3):161-162
SUMMARY Weber-Christian disease, a disease of unknown aetiology, is characterised by relapsing febrile episodes and systemic panniculitis. Glucocorticoid therapy is often useful during acute phases of the disease. This report describes a patient in whom hyperpyrexia did not respond to high-dose glucocorticoid treatment, yet did respond to a non-steroidal anti-inflammatory drug (NSAID). 相似文献
54.
Clinical Evaluation of a New Type of Centrifugal Pump 总被引:2,自引:0,他引:2
J. Ninomiya T. Shoji S. Tanaka M. Ikeshita M. Ochi S. Yamauchi T. Yajima H. Yamauchi T. Sugimotox T. Aizawa 《Artificial organs》1994,18(9):702-705
Abstract: The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump group, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass. 相似文献
55.
K Naora Y Katagiri K Iwamoto K Tanaka T Yamaguchi Y Sekine 《The Journal of antimicrobial chemotherapy》1992,30(5):673-683
The effects of fenbufen on the serum concentrations and penetration into the brain and CSF of sparfloxacin (AT-4140), a new quinolone antibacterial agent, were investigated in rats. At designated times after a bolus iv dose of sparfloxacin 10 mg/kg with or without fenbufen 20 mg/kg, arterial blood, CSF and whole brain were simultaneously collected from each rat. Sparfloxacin concentrations were assayed by HPLC. Serum concentration of sparfloxacin declined bi-exponentially with time and was not changed by coadministered fenbufen. Binding sparfloxacin to serum protein slightly decreased after the coadministration. No elevation of sparfloxacin concentrations was observed in either brain or CSF after coadministration with fenbufen except for only a few time-points. The pharmacokinetic analysis based on the physiological model indicated that fenbufen did not affect the permeability across the blood-brain or blood-CSF barrier. These results suggest that fenbufen may be unlikely to affect the pharmacokinetics, involving the entry into the central nervous system, of sparfloxacin. 相似文献
56.
Minoru Sasano Mihoko Tanaka Katsuhiko Nakata Shiro Mita 《Immunopharmacology and immunotoxicology》1991,13(1):121-133
(4R)-Hexahydro-7, 7-dimethyl-6-oxo-1, 2, 5-dithiazocine-4-carboxylic acid (SA3443) is a newly synthesized cyclic disulfide compound which offers potential hepatoprotective properties.
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
The effect of SA3443 on the induction of natural killer (NK) and cytotoxic T lymphocyte (CTL) activities was investigated. NK activity in BALB/c mice splenic cells was investigated using YAC-1 cells as target cells. SA3443, at a dose range of 30-300 mg/kg/day, augmented NK activity significantly when administered orally once daily for 4 days before the assay. Alloantigen-specific CTL activity in splenic cells from BALB/c mice was detected 9 days after sensitization with C57BL/6 mice splenic cells. SA3443, at a dose of 100 mg/kg/day, augmented CTL activity significantly when administered orally, once daily for 4 days beginning after the sensitization and for 2 days before the assay, while a high dose of SA3443, at 300mg/kg, suppressed CTL activity.
From these results, it is thought that SA3443 may assist in the elimination of hepatitis viruses from the liver in patients with chronic active hepatitis, by the activation of NK and/or CTL activities. 相似文献
57.
Renal leiomyomas large enough to be clinically diagnosed are extremely rare. We review 30 cases of clinically diagnosed renal leiomyoma from the literature in Japan, including our 2 new cases. Case 1: In a 52-year-old man with no symptoms a renal mass was found accidentally on an ultrasonogram. CT scan showed a mass with a cystic area at the upper pole of the right kidney. Angiogram showed a hypovascular mass. Case 2: CT scan revealed a cystic mass and angiogram showed an avascular mass at the upper pole of the left kidney in a 19-year-old man having gross hematuria and left flank pain. Transperitoneal nephrectomy was done in both cases. Histologically each tumor was composed of monotonous proliferation of spindle shaped cells without atypia, which showed intense immunoreactivity for alpha-smooth muscle actin. The diagnosis of benign leiomyoma was made in each case. In a review of 30 cases, we found that renal leiomyomas occur most often in female (77%), between decades 2 and 5 of life (median: 46 years). On the angiogram it appears most often as an avascular or hypovascular mass. CT scan shows cystic or mixed solid/cystic or solid lesion, occasionally with calcification. Preoperative diagnosis is extremely difficult to be made. Histologically, fibroma, angiomyolipoma, congenital mesoblastic nephroma and leiomyosarcoma should be differentiated. 相似文献
58.
59.
K Ishino T Murakami H Nakayama M Yamada T Morimoto K Hisamochi T Tanaka Y Senoo S Teramoto 《Acta medica Okayama》1991,45(4):223-231
A biventricular bypass type total artificial heart (BVB-TAH) utilizing two pusher-plate pumps was developed and implanted in a sheep for 48 days with excellent results. A Hall effect sensor was utilized to operate each pump independently with a full stroke at variable rates (VR). With this system, the animal's hemodynamics was kept physiologically, and all metabolic parameters except hemoglobin and hematocrit returned to normal three weeks after implantation. However, signs of infection appeared on the forty-second day, and consequently the animal fell into a state of shock. Even at that time the BVB-TAH maintained circulation by increasing pumping rate automatically. On the forty-eighth day, the animal could not stand and suffered from anuria; the experiment was then terminated after 1,140 h pumping. At autopsy, there was an enlarged heart with an atrophic change, 1,900 ml of pleural effusion, and 3,100ml of ascites fluid. Blood culture taken on the forty-seventh day yielded Acinetobacter calcoaceticus. The BVB-TAH operated in an independent VR mode maintained entire circulation, and has a capability of substituting the native heart function in any situation. 相似文献
60.
Y Tanaka M Shima K Yamaoka S Okada Y Seino 《Journal of nutritional science and vitaminology》1992,38(5):415-426
We examined the effects of retinoic acid (RA), 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3), and its synthetic analogue, 22-oxa-1,25-(OH)2D3, on differentiation of U937 cells by studying the cellular growth, surface marker expression and cytosolic free Ca2+ concentration ([Ca2+]i). RA inhibited cellular growth but did not induce expression of Mo2 (CD14), a monocyte/macrophage specific surface marker. To the contrary, 1,25-(OH)2D3 did not inhibit cellular growth, but increased CD 14-positive cells. Simultaneous addition of 1,25-(OH)2D3 and RA had no additive effect on cellular growth inhibition or CD14 expression. With regard to [Ca2+]i, however, 5 days' incubation with either of them increased the basal [Ca2+]i level and induced U937 cells to respond to formyl-methionyl-leucyl-phenylalanine (FMLP). When the cells were incubated with both 10(-6) M RA and 10(-8) M 1,25-(OH)2D3, basal [Ca2+]i was higher and FMLP caused a greater increase in [Ca2+]i than when only RA or 1,25-(OH)2D3 was added. These data suggest that RA and 1,25-(OH)2D3 induce monocytoid differentiation in U937 cells through different pathways and act synergistically in the differentiation process. The 22-oxa-1,25-(OH)2D3 induced CD14 expression, basal [Ca2+]i increase and [Ca2+]i response to FMLP, but did not cause cellular growth inhibition in U937 cells, and in these points, 22-oxa-1,25-(OH)2D3 exhibited no significantly different effects from 1,25-(OH)2D3. Thus, 22-oxa-1,25-(OH)2D3 has the same potent activity as 1,25-(OH)2D3 in inducing differentiation of U937 cells. 相似文献