全文获取类型
收费全文 | 17061篇 |
免费 | 715篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 204篇 |
儿科学 | 288篇 |
妇产科学 | 186篇 |
基础医学 | 2101篇 |
口腔科学 | 544篇 |
临床医学 | 1085篇 |
内科学 | 3957篇 |
皮肤病学 | 218篇 |
神经病学 | 1382篇 |
特种医学 | 732篇 |
外科学 | 3005篇 |
综合类 | 64篇 |
预防医学 | 548篇 |
眼科学 | 222篇 |
药学 | 1153篇 |
中国医学 | 25篇 |
肿瘤学 | 2133篇 |
出版年
2023年 | 76篇 |
2022年 | 123篇 |
2021年 | 265篇 |
2020年 | 153篇 |
2019年 | 177篇 |
2018年 | 273篇 |
2017年 | 182篇 |
2016年 | 236篇 |
2015年 | 241篇 |
2014年 | 353篇 |
2013年 | 415篇 |
2012年 | 689篇 |
2011年 | 687篇 |
2010年 | 456篇 |
2009年 | 404篇 |
2008年 | 690篇 |
2007年 | 678篇 |
2006年 | 726篇 |
2005年 | 752篇 |
2004年 | 719篇 |
2003年 | 716篇 |
2002年 | 739篇 |
2001年 | 772篇 |
2000年 | 775篇 |
1999年 | 700篇 |
1998年 | 245篇 |
1997年 | 186篇 |
1996年 | 182篇 |
1995年 | 132篇 |
1994年 | 107篇 |
1993年 | 105篇 |
1992年 | 464篇 |
1991年 | 408篇 |
1990年 | 372篇 |
1989年 | 456篇 |
1988年 | 375篇 |
1987年 | 332篇 |
1986年 | 357篇 |
1985年 | 337篇 |
1984年 | 248篇 |
1983年 | 158篇 |
1982年 | 74篇 |
1979年 | 144篇 |
1978年 | 100篇 |
1977年 | 86篇 |
1975年 | 80篇 |
1974年 | 75篇 |
1973年 | 75篇 |
1969年 | 92篇 |
1967年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
61.
RATIONALE AND OBJECTIVES. The sialographic ductal patterns of the parotid glands in patients with Sj?gren syndrome were compared with those of normal patients by measuring the fractal dimensions. METHODS. Fractal dimensions were estimated using the modified pixel dilation method. RESULTS. The mean fractal dimension was 1.64 +/- 0.06 for the normal glands and 1.39 +/- 0.10 for the glands with Sj?gren syndrome (P < .005). No correlation between the age or sex and fractal dimension was observed for both groups. In Sj?gren syndrome, a significant difference in the fractal dimension was observed between the subgroup having punctuate fillings with a diameter less than 1 mm and the subgroup from 1 to 2 mm (P < .001). CONCLUSION. The fractal dimension is useful as a numeric grading of the complexity of the ductal pattern and the progression of parotid disease. 相似文献
62.
63.
64.
Thyrotropin-releasing hormone (TRH), but not histidyl-proline diketopiperazine (cyclo[His-Pro]), induced transient hyperglycemia associated with hyperglucagonemia and marked hyperinsulinemia when placed intracerebroventricularly (i.c.v.) in anesthetized rats. This TRH-induced hyperglycemia was prevented by acute adrenalectomy. However, adrenalectomy did not prevent TRH-induced hyperinsulinemia or hyperglucagonemia. In streptozotocin-induced diabetic rats, i.c.v. administration of TRH caused progressive and pronounced hyperglycemia. i.c.v. TRH-induced hyperinsulinemia was abolished by vagotomy and by systemic administration of hexamethonium or atropine. These results suggest that TRH induces hyperglycemia mediated by stimulation of the sympathetico-adrenal system and hyperinsulinemia by stimulation of the vagus nerve, and that the rapid decline of plasma glucose levels following transient hyperglycemia is due to hyperinsulinemia. 相似文献
65.
S Minohara S Sasaki K Asada H Muraki T Kodama S Hasegawa M Morita E Tsujii A Takeuchi 《Kyobu geka. The Japanese journal of thoracic surgery》1992,45(12):1106-1108
The patient was a one-year-old boy, who underwent surgery with a diagnosis of atrial septal defect (ASD). During operation, aorto-pulmonary window (A-P window) which had not been detected by the preoperative examinations, was found. Therefore, the A-P window was divided prior to closing ASD. The patient is in good condition six months after the operation. The causes of the inaccurate preoperative diagnosis were discussed. 相似文献
66.
Mayumi Matsuta Yuko Imamura Morimasa Matsuta Saiichi Kon Kohsuke Sasaki 《The Journal of dermatology》1994,21(1):14-19
We have applied DNA flow cytometric analysis to paraffin-embedded tissue sections of primary malignant melanomas. Conventionally, flow cytometric analysis of paraffin-embedded tissue sections has been done by the method of Hedley et al. We added ultrasound treatment to the method of Hedley et al. and a lower value of coefficient of variation was shown. Furthermore, a new technique, fluorescence in situ hybridization with a chromosome-specific repetitive DNA probe, was used for the analysis of chromosomal numerical aberrations in the same paraffin-embedded tissue sections. The DNA flow cytometric analysis showed that in 8 cases six primary malignant melanomas were of the aneuploid pattern and two cases of lentigo maligna (melamona in situ) were of the diploid pattern. By fluorescence in situ hybridization, the two cases with the diploid pattern had spots/nucleus of 1.28 and 1.12, and those with the aneuploid pattern had spots/nucleus from 2.01 to 2.27. Only one nodular melanoma in an aneuploid case showed spots/nucleus of 1.71. These data indicate that fluorescence in situ hybridization with chromosome-specific repetitive DNA probes can serve as a cytogenetic tool for the analysis of interphase nuclei of solid human tumors and may be useful for the study of tumor cell heterogeneity. 相似文献
67.
S Kisara A Hayashi I Maekawa S Furusawa Y Takayanagi K Sasaki 《Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan》1992,112(11):837-845
The biochemical activity of cepharanthine and the possible mechanism by which it reverses the resistance to doxorubicin in P388 leukemia cells were examined in vitro. The microfluorometric analysis of the cellular level of doxorubicin in drug-resistant cells showed that cepharanthine markedly enhanced the sensitivity of doxorubicin against resistant cells in the cellular level. Cepharanthine also enhanced the inhibitory effect of doxorubicin on the incorporation of thymidine into DNA in resistant cells. The analysis of DNA histogram obtained by flow cytometry showed that doxorubicin exerted its growth-inhibitory effect by blocking the cell cycle at the G2 phase in P388 cells. At higher concentrations, doxorubicin prolonged the S phase and inhibited cell cycle progression to the G2/M phase in cells. The treatment with cepharanthine potentiated these blocking effects induced by doxorubicin in cells. It seems that the modifications of the biological effect of doxorubicin by cepharanthine are due to the change of their ability to induce DNA damage in cells. 相似文献
68.
Y Inoue T Momose K Amo T Ohtake T Watanabe N Kosaka J Nishikawa Y Sasaki 《Kaku igaku. The Japanese journal of nuclear medicine》1992,29(8):955-962
Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood was studied mainly in vitro. When 99mTc-ECD was mixed with blood taken from 12 subjects, the octanol extraction ratio of ECD (y) decreased rapidly and the octanol extraction ratio-time profile well fitted a monoexponential curve (y = Ae-kt/1000, A, k: constant, t: time after mixing). The k value and hematocrit (Ht) were significantly correlated (k = 0.376Ht-3.27, r = 0.897, p less than 0.001), therefore, it was suggested that the majority of the enzyme which dissolves ECD exists in red blood cells. When ECD was mixed with blood, there were more hydrophilic products of ECD in plasma than those generated by the enzyme in plasma. In vivo input function of 99mTc-ECD was calculated by arterial blood sampling and octanol extraction. The duration of effective input was relatively short, which was attributed to rapid decrease of octanol extraction ratio in vivo. 相似文献
69.
I Hisatome N Sasaki M Yamakawa M Kobayashi Y Tanaka H Kosaka A Yoshida H Kotake H Mashiba A Takeda 《Nephron》1992,61(2):196-199
Two patients with diabetes mellitus had persistent hypouricemia due to increased urate clearance; the degree of the apparent renal hypouricemia with uricosuria was quite mild. At the onset of diabetes, their serum urate levels were normal. Even after good diabetes control in both cases, hypouricemia continued. Based on the pharmacological evaluation in both patients, pyrazinamide administration could partially decrease urate clearance, however, suppression by pyrazinamide was less than in normal subjects, and probenecid increased urate clearance. These results suggest that the present cases had a renal abnormality affecting tubular presecretory reabsorption of urate, which might be due to diabetes mellitus. 相似文献
70.
Y Kajigaya K Ikuta H Sasaki Y Koiso T Funabiki S Matsuyama 《Journal of Japan Haematological Society》1988,51(5):832-838