全文获取类型
收费全文 | 14113篇 |
免费 | 613篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 336篇 |
妇产科学 | 101篇 |
基础医学 | 1637篇 |
口腔科学 | 406篇 |
临床医学 | 791篇 |
内科学 | 3688篇 |
皮肤病学 | 196篇 |
神经病学 | 967篇 |
特种医学 | 585篇 |
外科学 | 2567篇 |
综合类 | 80篇 |
预防医学 | 499篇 |
眼科学 | 421篇 |
药学 | 837篇 |
中国医学 | 21篇 |
肿瘤学 | 1499篇 |
出版年
2023年 | 79篇 |
2022年 | 178篇 |
2021年 | 335篇 |
2020年 | 155篇 |
2019年 | 194篇 |
2018年 | 246篇 |
2017年 | 202篇 |
2016年 | 253篇 |
2015年 | 269篇 |
2014年 | 358篇 |
2013年 | 491篇 |
2012年 | 682篇 |
2011年 | 757篇 |
2010年 | 439篇 |
2009年 | 367篇 |
2008年 | 670篇 |
2007年 | 742篇 |
2006年 | 705篇 |
2005年 | 664篇 |
2004年 | 684篇 |
2003年 | 682篇 |
2002年 | 661篇 |
2001年 | 423篇 |
2000年 | 403篇 |
1999年 | 414篇 |
1998年 | 192篇 |
1997年 | 145篇 |
1996年 | 129篇 |
1995年 | 116篇 |
1994年 | 90篇 |
1993年 | 90篇 |
1992年 | 287篇 |
1991年 | 245篇 |
1990年 | 245篇 |
1989年 | 280篇 |
1988年 | 208篇 |
1987年 | 209篇 |
1986年 | 196篇 |
1985年 | 187篇 |
1984年 | 138篇 |
1983年 | 100篇 |
1982年 | 73篇 |
1981年 | 57篇 |
1979年 | 80篇 |
1978年 | 48篇 |
1977年 | 52篇 |
1975年 | 50篇 |
1974年 | 47篇 |
1973年 | 49篇 |
1971年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Isolation of amantadine-resistant influenza a viruses (H3N2) from patients following administration of amantadine in Japan 总被引:3,自引:0,他引:3 下载免费PDF全文
Iwahashi J Tsuji K Ishibashi T Kajiwara J Imamura Y Mori R Hara K Kashiwagi T Ohtsu Y Hamada N Maeda H Toyoda M Toyoda T 《Journal of clinical microbiology》2001,39(4):1652-1653
In Japan, the use of amantadine for treatment of influenza A virus infection was not accepted until November 1998, although it was widely used for treatment of Parkinsonism. Since then, we have monitored the emergence of amantadine-resistant viruses and isolated two viruses from patients on long-term treatment with amantadine. 相似文献
52.
K Hara F Mitsuhashi T Sakawaki H Ohkura 《Rinsho byori. The Japanese journal of clinical pathology》1989,37(7):789-794
Serum CA 50 was determined by a time resolved fluorometric immunoassay (TR-FIA) with CANAG CA-50 DELFIA kit. Evaluation of the assay system gave satisfactory results in its sensitivity, accuracy, reproducibility, dynamic range and easy handling. No prozone phenomenon was observed up to 347,000 U/ml. From a histogram of 134 normal sera, the cut off point was determined at 34 U/ml. CA 50 in 202 patients' sera was determined with this assay. Nineteen of 20 patients pancreatic cancer, 6 of 21 gastric cancer, 14 of 25 hepatoma gave positive values. In comparison with CA 19-9, higher values and higher rates of positive CA 50 were observed in benign and malignant liver diseases, suggesting its non-cancerous origin in the liver. A high correlation was observed between the level of CA 50 and CA 19-9 of 157 patients' sera. Serum CA 50 was completely correlated with CA 19-9 in the clinical course of patients with pancreatic cancer, but not in patients with hepatoma. Thus we conclude that the CANAG CA-50 DELFIA System is useful for the diagnosis and monitoring cancer patients but must be used with care because of its elevation in benign liver diseases. 相似文献
53.
Masami Yamamoto Hideaki Enzan ° Hiroshi Hara ° Soichi Iijima °° 《Pathology international》1978,28(4):513-521
Findings of perivascular mesenchymal cells and fibroblasts in mice receiving large doses of vitamin A were described. Liver, lung, intestine and skin were investigated by fluorescence and electron microscopy. Marked increase of fluorescence of vitamin A was observed in the sinusoidal wall of the liver, in the alveolar septa of the lungs, in the propria mucosa, submucosa and muscular layer of the intestine and in the dermis of the abdominal skin. Increased fluorescence of these organs corresponded, ultrastructually, to the appearance of numerous fat droplets in Ito cells of the liver, septal cells of the lung and fibroblasts of the intestine and of the skin. All of these cells showed the same morphological features and the same distribution in the tissue, namely in the interstitial connective tissue space. These findings indicate that vitamin A storing cells are distributed widely in the connective tissue of various organs and that perivascular vitamin A storing mesenchymal cells and interstitial fibroblasts are probably of common fibroblastic cell line. 相似文献
54.
Yoshitaka Iwasaki Judith Bartlett Kelly MacKay Jennifer Mactavish Janice Ristock 《Journal of community psychology》2008,36(6):702-722
This study reports key findings from a research project, which examined the stress and coping mechanisms of several nondominant groups of individuals. The groups were based in Winnipeg, Manitoba, Canada and included (a) Aboriginal individuals with diabetes, (b) individuals with disabilities, and (c) gays and lesbians. Our analyses of personal narratives and life stories have led to develop an interpretive map of findings that depicts mechanisms of how stress and coping operate. Specifically, the interpretive map consists of personal and structural stressors, meanings of stress, and personal and structural resources, as well as of two constructs termed intersectionality and social exclusion. Not only are nondominant voices and lived experiences recognized and incorporated into an emergent interpretive map, but this map also articulates the complex ways in which multiple identities intersect (i.e., intersectionality) and the realities of being excluded socioeconomically, culturally, and politically among nondominant groups (i.e., social exclusion). © 2008 Wiley Periodicals, Inc. 相似文献
55.
Y Akiyama T Suzuki M Tanaka K Kobayashi T Kagiri T Ishibashi H Kitagawa F Imai K Hara Y Doi 《Arerugī》1990,39(6):542-547
We encountered a patient who developed an overlap syndrome of progressive systemic sclerosis (PSS), systemic lupus erythematosus (SLE), polymyositis (PM) and Sj?gren's syndrome (SjS) while we were treating her for mixed connective tissue disease (MCTD). This 42-year-old woman had been photosensitive since 18 years of age. In 1986, Raynaud's phenomenon, swollen hands and arthralgia appeared; therefore, we started to treat this patient based on a diagnosis of MCTD. At that time, her anti-RNP antibody titer was 82,920, but she was negative to anti-Sm antibody. In 1988, she was admitted to our hospital with chief complaints of aggravation of polyarthralgia and myalgia. On physical examination, she showed difficulty in opening her mouth, systemic dermal sclerosis, a decrease in muscular strength and rales. In laboratory tests, her myogenic enzyme level was increased, and she was found to be positive to LE cells, antinuclear antibody, anti-DNA antibody, anti-ENA antibody and anti-SSA antibody. Furthermore, histological features clearly corresponding to those of PSS were found by skin biopsy, myogenic changes by electromyography, evidence of chronic inflammation of the salivary glands by lip biopsy, and proliferative changes in the mesangium were detected by renal biopsy. The concept of MCTD, especially the differences from overlap syndrome, is vague. Therefore we need further study about many cases. Since there have been no reports on cases having sufficient evidence of the development of the overlap syndrome of PSS, SLE, PM and SjS during a course of MCTD, our patient would provide very useful data contributing to the study of MCTD. 相似文献
56.
A case of leiomyosarcoma of the spermatic cord, occurring in a 79-year-old male patient, is reported. The tumor was resected with high inguinal ligation and orchiectomy. It was located at the scrotal part of the spermatic cord on the left side and was shown to have originated from the spermatic duct using the dissecting method. Histologically, it was identical to leiomyosarcoma showing a typical morphological appearance of smooth muscle cell tumor in the conventional histochemical preparations as well as a focal positive reaction to antidesmin antibody, a marked nuclear pleomorphism, and abundant mitotic figures. The patient had been untroubled for six months after the resection of the tumor. Leiomyosarcoma arising in spermatic cord is quite rare. 相似文献
57.
58.
To evaluate the pathogenetic roles of immune complexes and alveolar hyaline membrane in idiopathic interstitial pneumonia (IIP), immunohistological and ultrastructural studies of the kidney and lung were performed in 23 cases of IIP, 19 cases of autoimmune diseases, 17 cases of interstitial pneumonia other than IIP, and 11 cases of bronchopneumonia as a control group. None of the cases of IIP or interstitial pneumonia other than IIP showed immune complexes in the alveolar and glomerular capillary walls. On the other hand, one case of SLE was positive for IgG and components of complement along the alveolar and glomerular capillary walls. The alveolar hyaline membrane in the present cases revealed immunoglobulins as well as components of complement, which were poorly soluble in chaotropic solution or acidic buffer. These results indicate that circulating immune complexes play a minor role in the pathogenesis of IIP and other types of interstitial pneumonia, and that there is no relationship between immune complex deposition in alveoli and the alveolar hyaline membrane. It is necessary to further investigate factors other than immune complexes involved in alveolar tissue damage and to clarify the significance of the hyaline membrane in the processes occurring from acute changes to pulmonary fibrosis in IIP. 相似文献
59.
太空发育鸡胚的前庭感受器细胞形态学研究 总被引:4,自引:0,他引:4
为了探讨太空微重力对鸡胚前庭感觉上皮细胞的形态发育的影响 ,选取在航天飞机 (STS-2 9)发育鸡胚和地面发育鸡胚各两只 ,利用计算机显微测量技术分别测量椭圆囊和球囊的毛细胞、支持细胞核的切面面积、周长、形状系数。太空发育鸡胚的球囊支持细胞核的切面面积、周长显著大于地面组 ,形状系数无差异 ;太空发育鸡胚的椭圆囊支持细胞核的切面面积、周长、形状系数以及椭圆囊和球囊毛细胞的切面面积、周长与地面发育鸡胚相比无明显差异。微重力可能对球囊支持细胞核的体积发育有影响 ,对椭圆囊和球囊的毛细胞以及椭圆囊支持细胞核的形态发育无影响。 相似文献
60.
Tamaru N Hishikawa Y Ejima K Nagasue N Inoue S Muramatsu M Hayashi T Koji T 《Laboratory investigation; a journal of technical methods and pathology》2004,84(11):1460-1471
Although estrogen is known to play a crucial role in the pathogenesis of breast cancer, the molecular mechanisms underlying the action of estrogen remain elusive. In the present study, we focused on keratinocyte growth factor (KGF) and its receptor (KGFR) in the pathogenesis of breast cancer, as a growth factor mediating estrogen action, since significant roles of KGF were demonstrated in various steroid hormone-dependent tissues. First, using paraffin-embedded specimens from 42 breast cancer patients, we examined expression patterns of KGF and KGFR by both immunohistochemistry using newly generated antibodies and nonradioactive in situ hybridization with T-T dimerized synthetic oligonucleotide probes. We next compared the results with the expression of estrogen receptor (ER) alpha and beta, proliferative activity and apoptotic frequency (TUNEL staining). Also, the similar approaches were taken to analyze the expression and role of KGF in ER-positive (MCF7, ZR-75-1) and ER-negative (SK-BR-3, MDA-MB-231) human breast cancer cell lines in vitro. In the surgical specimens, KGF was expressed in cancer cells as well as stromal cells in 19/42 cases (45%), while KGFR was found in cancer cells in 24/42 cases (57%). The distribution of protein and mRNA in the analysis of both KGF and KGFR expression generally coincided. Moreover, KGF expression was closely associated with the expression of ER alpha, and the coexpression of KGF and KGFR significantly correlated with lower TUNEL index, but not with proliferative activity. In accordance with the in vivo findings, KGF expression was detected only in ER alpha-positive MCF7 and ZR-75-1 cells in vitro. And more importantly, we found the inhibitory effect of KGF upon the induction of apoptosis by anticancer drugs in MCF7 cells. Collectively, our results indicate that ER alpha may be involved in KGF expression, and that KGF may play antiapoptotic roles, rather than mitogenic, in human breast cancer. 相似文献