全文获取类型
收费全文 | 11315篇 |
免费 | 621篇 |
国内免费 | 103篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 243篇 |
妇产科学 | 83篇 |
基础医学 | 1272篇 |
口腔科学 | 242篇 |
临床医学 | 920篇 |
内科学 | 3302篇 |
皮肤病学 | 84篇 |
神经病学 | 862篇 |
特种医学 | 511篇 |
外科学 | 1854篇 |
综合类 | 55篇 |
预防医学 | 299篇 |
眼科学 | 119篇 |
药学 | 669篇 |
中国医学 | 10篇 |
肿瘤学 | 1428篇 |
出版年
2023年 | 158篇 |
2022年 | 299篇 |
2021年 | 472篇 |
2020年 | 242篇 |
2019年 | 285篇 |
2018年 | 393篇 |
2017年 | 268篇 |
2016年 | 294篇 |
2015年 | 276篇 |
2014年 | 398篇 |
2013年 | 433篇 |
2012年 | 742篇 |
2011年 | 816篇 |
2010年 | 454篇 |
2009年 | 374篇 |
2008年 | 625篇 |
2007年 | 592篇 |
2006年 | 568篇 |
2005年 | 571篇 |
2004年 | 535篇 |
2003年 | 538篇 |
2002年 | 475篇 |
2001年 | 180篇 |
2000年 | 137篇 |
1999年 | 169篇 |
1998年 | 121篇 |
1997年 | 105篇 |
1996年 | 104篇 |
1995年 | 75篇 |
1994年 | 60篇 |
1993年 | 65篇 |
1992年 | 109篇 |
1991年 | 109篇 |
1990年 | 116篇 |
1989年 | 92篇 |
1988年 | 91篇 |
1987年 | 78篇 |
1986年 | 86篇 |
1985年 | 64篇 |
1984年 | 44篇 |
1983年 | 38篇 |
1982年 | 25篇 |
1981年 | 24篇 |
1977年 | 25篇 |
1973年 | 25篇 |
1970年 | 29篇 |
1969年 | 25篇 |
1968年 | 30篇 |
1967年 | 23篇 |
1966年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
T Fujimori D Hirayama A Gotoh T Tabata M Yukawa Y Yamamura K Satonaka T Nakamura T Teramoto S Kitazawa 《Gastroenterologia Japonica》1992,27(2):187-190
Leiomyoblastoma has been regarded as a neoplasm of smooth muscle origin. With recent progress in immunohistostaining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. It has been claimed that gastrointestinal non-epithelial tumors should be regarded as stromal tumors in order to study their origin. In the present study, we performed various forms of immunohistostaining in seven cases of leiomyoblastoma to determine their origin. One case expressed desmine and muscle specific actin and was considered to be derived from smooth muscle. Four neoplasms expressed X-100 protein (two cases were also NSE positive) and were thought to be derived from the nerve. Two cases were of unknown derivation. These results suggest that the cells of leiomyoblastoma may arise from a primitive to totipotential cell of neural lineages that may anomalously express smooth muscle filaments. 相似文献
14.
15.
16.
17.
A. Komiyama I. Kamo S. Furukawa S. Akazawa K. Hirayama E. Satoyoshi 《Journal of neurology》1988,235(4):207-213
Summary Antibodies against phosphate-buffered-saline extracts (SE) of non-acetylcholine receptor (AChR) skeletal muscle antigens were found in patients with myasthenia gravis (MG). The antigenicity of SE was distributed in three fractions with molecular masses of over 200 kDa, 90–150 kDa and 7–14 kDa on gel filtration. These fractions shared common antigenicities. Further analysis of 90–150 kDa fractions on sodium dodecyl sulphate polyacrylamide gel electrophoresis showed five major bands, ranging from 105 kDa to 275 kDa. The antibodies against SE were detected in 52% (58/112) of the MG patients; incidence and titres were higher in the thymoma group (n=21; 90% and 0.872 respectively) than in the non-thymoma group (n=91; 43% and 0.200, P<0.001). In patients without a thymoma, these antibodies were frequently observed in late-onset disease and the severe generalized form (P<0.01). In 4 of 7 ocular MG patients without anti-AChR antibodies, low but appreciable levels of anti-SE antibodies were found. In 73% (11/15) of generalized MG patients treated with prednisolone and thymectomy, anti-SE antibody titres changed in association with those of anti-AChR antibodies and with the clinical course. Both antibody titres increased synchronously in patients who developed crises. 相似文献
18.
19.
Toshikazu Saito M.D. Hideaki Ishizawa M.D. Fumiaki Tsuchiya M.D. Hiroki Ozawa M.D. Naohiko Takahata M.D. 《Psychiatry and clinical neurosciences》1986,40(2):189-194
Abstract: Monoamine and their acid metabolites were determined in the CSF of 18 drug-treated chronic schizophrenic patients with the symptoms of tardive dyskinesia and neuroleptic-induced Parkinsonism (Parkinsonism). Six healthy volunteers were used as the control group.
The norepinephrine (NE) levels were found to be significantly higher in the patients with tardive dyskinesia than in the controls. Furthermore, elevated CSF NE levels were also observed in the patients with Parkinsonism. Epinephrine (E) and Dopamine (DA) were not present in the CSF of the control group, whereas measurable levels of DA could be detected in 4 out of 9 and E was found in 8 out of 9 patients with tardive dyskinesia. The mean concentration of HVA was slightly but not significantly elevated in the patients with tardive dyskinesia and Parkinsonism. The mean values of CSF 5-HIAA were all within the normal range in both patient groups. From the above results, it was suggested that abnormal adrenergic activity rather than abnormal dopaminergic activity may play an important role as a mechanism in the etiopathogenesis of extrapyramidal disorders. Furthermore, in the patients with Parkinsonism, CSF neurochemical observations were similar to those of the patients with tardive dyskinesia in this study. It may help to explain the clinical coexistence of tardive dyskinesia and neuroleptic-induced Parkinsonism. 相似文献
The norepinephrine (NE) levels were found to be significantly higher in the patients with tardive dyskinesia than in the controls. Furthermore, elevated CSF NE levels were also observed in the patients with Parkinsonism. Epinephrine (E) and Dopamine (DA) were not present in the CSF of the control group, whereas measurable levels of DA could be detected in 4 out of 9 and E was found in 8 out of 9 patients with tardive dyskinesia. The mean concentration of HVA was slightly but not significantly elevated in the patients with tardive dyskinesia and Parkinsonism. The mean values of CSF 5-HIAA were all within the normal range in both patient groups. From the above results, it was suggested that abnormal adrenergic activity rather than abnormal dopaminergic activity may play an important role as a mechanism in the etiopathogenesis of extrapyramidal disorders. Furthermore, in the patients with Parkinsonism, CSF neurochemical observations were similar to those of the patients with tardive dyskinesia in this study. It may help to explain the clinical coexistence of tardive dyskinesia and neuroleptic-induced Parkinsonism. 相似文献
20.
Tomoyuki Yamashita M.D. Yoshihide Fujimoto M.D. Takaya Kodama M.D. Akira Hirayama M.D. Takao Obara M.D. Yukio Ito M.D. Motohiko Aiba M.D. Kiyoko Kusakabe M.D. 《World journal of surgery》1988,12(4):559-563
Clinicopathologic studies were performed to establish rational criteria for total thyroidectomy as a treatment of follicular carcinoma. During the 4-year period from 1981 to 1984, total thyroidectomy was carried out on 23 patients in whom unequivocal vascular invasion and/or obvious extracapsular extension were disclosed on pathological study of the primary thyroid lesion. Although occult metastatic lesions were detected postoperatively in 5 patients, no distant metastases have been found in 12. Distant metastasis was clinically manifest on admission in the other 6 patients. The degree of vascular invasion at the primary lesion was not correlated with the occurrence of distant metastasis. However, 10 of the 15 patients with tumors characterized by a thick fibrous capsule had distant metastases, while all but 1 of 8 patients with a thin capsule showed no metastasis. Apparent capsular invasion seemed to increase the relative risk of distant metastasis. On the other hand, solid clusters of tumor cells containing a variable number of small follicles, which characterize Langhans' wuchernde Struma, were found in 6 patients, and 5 of them showed distant metastases. Thus, total thyroidectomy should be considered when (a) distant metastases are clinically apparent, (b) the primary lesion has a thick fibrous capsule with or without obvious capsular invasion, or (c) solid clusters of tumor cells are demonstrated microscopically.
Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987. 相似文献
Resumen Se realizaron estudios clinicopatológicos con el propósito de establecer criterios racionales para la tiroidectomía total en el tratamiento del carcinoma folicular. En el curso de un perfodo de 4 anos entre 1981 y 1984, se realizó tiroidectomía total en 23 pacientes en quienes se halló inequívoca invasión vascular y/o obvia extension extracapsular en el examen histopatológico de la lesión tiroidea primaria. Aunque postoperatoriamente se detectaron lesiones metastáticas ocultas en 5 pacientes, no se encontraron metástasis distantes en 12. Metástasis distantes eran clínicamente manifiestas en el momenta de la admisión en los otros 6 pacientes. El grado de invasión vascular en la lesión primaria no apareció correlacionado con la ocurrencia de metástasis distantes. Sin embargo, 10 de los 15 pacientes con tumores caracterizados por una cápsula gruesa y fibrosa tenían metástasis distantes, mientras solo 1 de 8 pacientes con tumores de cápsula fina mostró metástasis. La invasión capsular aparente parece incrementar el riesgo relativo de metástasis distantes. Por otra parte, agrupaciones sólidas de células tumorales con presencia de números variables de folículos pequeños, que caracterizan al wuchernde Struma de Langhans, fueron encontrados en 6 pacientes, 5 de los cuales mostraron metastasis distantes. Por lo tanto, se debe considerar la tiroidectomía total cuando: (a) haya metástasis distantes clínicamente aparentes, (b) la lesión primaria tenga una gruesa cápsula fibrosa con o sin invasión capsular obvia, y (c) se demuestren microscópicamente agrupaciones sólidas de células tumorales.
Résumé Une étude clinicopathologique a été menée pour déterminer les critères de thyroïdectomie totale comme traitement dans le cancer folliculaire de la thyroïde. Pendant 4 ans, de 1981 à 1984, 23 patients ont subi une thyroïdectomie totale pour envahissement vasculaire non équivoque et/ou extension extracapsulaire évidente découverte sur la pièce d'exérèse initiale. Cinq patients avaient des métastases occultes découvertes dans la période postopératoire, 6 avaient des métastases cliniquement évidentes, alors que 12 ne présentaient aucun signe de métastase à distance. Le degré d'envahissement vasculaire de la lésion primitive n'était pas corrélé avec la survenue de métastases à distance. Cependant, 10 des 15 patients à tumeurs caractérisées par un épaississement de la capsule fibreuse avaient des métastases à distance, alors que 7 des 8 patients avec une capsule mince n'avaient pas de métastases. L'envahissement capsulaire était associé à un plus grand risque de métastases à distance. Des amas solides de cellules tumorales contenant de petits follicules, le wuckernde struma de Langhans, étaient retrouvés dans 6 cas, dont 5 avaient des métastases à distance. Ainsi, la thyroïdectomie totale est préconisée lorsque (a) des métastases à distance sont cliniquement évidentes, (b) la lésion primitive possède une capsule fibreuse épaisse avec ou sans envahissement évident, et (c) on met en évidence des cellules tumorales en amas microscopiquement.
Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987. 相似文献