全文获取类型
收费全文 | 8833篇 |
免费 | 431篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 193篇 |
儿科学 | 248篇 |
妇产科学 | 71篇 |
基础医学 | 1096篇 |
口腔科学 | 195篇 |
临床医学 | 564篇 |
内科学 | 1982篇 |
皮肤病学 | 305篇 |
神经病学 | 755篇 |
特种医学 | 350篇 |
外科学 | 1122篇 |
综合类 | 59篇 |
预防医学 | 297篇 |
眼科学 | 137篇 |
药学 | 771篇 |
中国医学 | 29篇 |
肿瘤学 | 1130篇 |
出版年
2023年 | 52篇 |
2022年 | 80篇 |
2021年 | 174篇 |
2020年 | 97篇 |
2019年 | 117篇 |
2018年 | 133篇 |
2017年 | 125篇 |
2016年 | 115篇 |
2015年 | 136篇 |
2014年 | 201篇 |
2013年 | 258篇 |
2012年 | 398篇 |
2011年 | 437篇 |
2010年 | 267篇 |
2009年 | 258篇 |
2008年 | 404篇 |
2007年 | 500篇 |
2006年 | 447篇 |
2005年 | 388篇 |
2004年 | 469篇 |
2003年 | 436篇 |
2002年 | 458篇 |
2001年 | 259篇 |
2000年 | 286篇 |
1999年 | 289篇 |
1998年 | 96篇 |
1997年 | 94篇 |
1996年 | 88篇 |
1995年 | 82篇 |
1994年 | 81篇 |
1993年 | 68篇 |
1992年 | 204篇 |
1991年 | 179篇 |
1990年 | 163篇 |
1989年 | 169篇 |
1988年 | 145篇 |
1987年 | 139篇 |
1986年 | 146篇 |
1985年 | 95篇 |
1984年 | 88篇 |
1983年 | 70篇 |
1982年 | 40篇 |
1980年 | 35篇 |
1979年 | 54篇 |
1978年 | 40篇 |
1975年 | 35篇 |
1971年 | 34篇 |
1969年 | 37篇 |
1967年 | 40篇 |
1966年 | 36篇 |
排序方式: 共有9304条查询结果,搜索用时 15 毫秒
11.
A. Robert Spitzer Shalom Stahl David Yarnitsky Ernest W. Johnson John R. Wilson R. A. C. Hughes Stefania Morino Giovanni Antonini Kiyotoshi Kaneko Yoji Ohnishi Tetsushi Atsumi Isao Hozumi Tadashi Miyatake Tetsuo Furukawa James P. Knochel Ikuo Mineo Seiichiro Tarui Francis O. Walker Andrew J. Gitter Walter C. Stolov Nicholas J. Capozzoli 《Muscle & nerve》1996,19(4):531-538
12.
Abstract: We report 3 children with leukemia cutis observed at the initial diagnosis of systemic leukemia. Leukemia subtypes in the three children were congenital monocytic, acute undifferentiated, and acute monocytic, respectively. The patients were girls age 10 days, 14 years, and 11 months, respectively, at diagnosis. We describe the clinical features of the cases and the results of immunohistochemical studies on paraffin-embedded skin biopsy specimens. The skin lesions were tumors and areas of reddish purple erythema in the first child, pigmented erythema in the second, and bright red erythema in the third. In the first two patients skin lesion biopsy specimens had dense leukemic infiltrates in the dermis with reactive T lymphocytes scattered among them. In the third patient, the infiltrating cells were almost all reactive T lymphocytes, with a few leukemic cells. A relationship between the leukemic-reactive cell ratio and the prognosis was suggested; dense leukemic cell infiltrates may be associated with a poor prognosis. 相似文献
13.
Spontaneous photon emission (chemiluminescence, CL) as a monitor of free radical evolution in Drosophila melanogaster which had been maintained at 25 or 30 degrees C for 5 days after emergence was measured. When maintained at 30 degrees C the fly CL intensity was stronger than at 25 degrees C. Under the condition of the higher temperature, the fly life span was shorter (mean life span = 29 days at 30 degrees C and 63 days at 25 degrees C), and oxygen consumption (3.7 microliters/mg.h at 25 degrees C, 4.9 microliters/mg.h at 30 degrees C) and the mobility (movement distance = 25 mm/min at 25 degrees C, 700 mm/min at 30 degrees C) increased, together with augmentation of phospholipid hydroperoxide in the fly total lipids. The CL spontaneously emitted from fly homogenate was decreased by the free radical scavengers both in experiments in vivo and in vitro. The hypothesis is proposed that as the oxygen metabolism grows active, the chemiluminescent reactions that involve oxygen-dependent free radical metabolism, including membrane phospholipid hydroperoxidation, contribute to the acceleration of senescence of fly bodies. 相似文献
14.
15.
Yoshiko Ogata Yoshihiro Mori Hikari Koga Kazuya Awai Yukako Arakawa Norihiko Nakanishi Mikio Kataoka Fumikazu Kohi 《Nihon Kokyūki Gakkai zasshi》2004,42(9):837-841
A 22-year-old man was urgently admitted for pneumothorax. He continued complaining of exertional dyspnea and dry cough after the pneumothorax healed. About three months later, an atypical pulmonary mycobacteriosis by mycobacterium kansasii was identified. Exertional dyspnea increased after chemotherapy was administered, and the patient was readmitted because of difficulty in daily life activities. Chest radiographs and CT scans showed bilateral pulmonary hyperinflation and a narrowed heart shadow. There was also marked combined ventilatory impairment, as identified by a respiratory function test. Furthermore, the histological findings of surgically removed lung tissue revealed accumulation of lymphocytes in the wall of a small bronchus. Idiopathic bronchiolitis obliterans was diagnosed from the clinical course and clinical findings. The patient is now being monitored and is awaiting lung transplantation. 相似文献
16.
Idiopathic membranous nephropathy in two brothers 总被引:1,自引:0,他引:1
Idiopathic membranous nephropathy has been reported rarely to develop in genetic association with certain HLA antigens. This paper describes two male siblings presenting with nephrotic syndrome with histologically proven membranous nephropathy. The younger brother maintained a normal renal function with slight proteinuria during the 3 years of follow-up, but the older one experienced a rapid decline in renal function and had to be put on maintenance hemodialysis. No clinical evidence of contributory underlying disease such as malignancy or systemic lupus erythematosus could be found. HLA typing was carried out in the two patients and in members of their family. Several HLA antigens were found to be shared by the two patients. However, the HLA antigens which have been reported to be associated with idiopathic membranous nephropathy were not found in either of them. 相似文献
17.
A Nishikawa F Furukawa M Mitsui T Enami T Kawanishi T Hasegawa M Takahashi 《Carcinogenesis》1992,13(7):1155-1158
The effects of calcium chloride on glandular stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and sodium chloride were investigated in male outbred Wistar rats. Animals were given MNNG solution (100 p.p.m.) as drinking water and simultaneously fed a diet supplemented with 5% sodium chloride for 8 weeks. Matched negative controls received neither MNNG nor sodium chloride. Rats were then fed basal diet and given calcium chloride solution (1 or 0.2%) or tap water for the following 52 weeks. The incidences and multiplicities of preneoplastic hyperplasias in the glandular stomachs of rats given MNNG/sodium chloride followed by 1 and 0.2% calcium chloride were significantly lower than those in rats given MNNG/sodium chloride alone. The inhibitory effects of calcium were exerted in a dose-dependent manner. Calcium treatment also showed a tendency to inhibit the development of gastric adenocarcinomas although this was not statistically significant. Rats without carcinogen treatment had neither carcinomas nor preneoplastic hyperplasias in the glandular stomach. Calcium intake also significantly reduced the levels of malondialdehyde, a measure of lipid peroxidation, in the gastric mucosa and urine, the former in a dose-dependent manner. Thus, calcium chloride exerted inhibitory effects when given during the post-initiation phase of two-stage glandular stomach carcinogenesis in rats. 相似文献
18.
A Nishikawa F Furukawa T Imazawa H Yoshimura K Mitsumori M Takahashi 《Carcinogenesis》1992,13(8):1379-1382
The modulating effects of caffeine, nicotine, ethanol and sodium selenite on development of N-nitrosobis(2-oxopropyl)-amine (BOP)-initiated pancreatic tumors were investigated. Female Syrian golden hamsters were given s.c. injections of BOP (10 mg/kg body weight) or saline alone once a week for 3 weeks and then administered 2000 p.p.m. caffeine, 25 p.p.m. nicotine, 20% ethanol or 4 p.p.m. sodium selenite in their drinking water for the next 37 weeks. Control animals were given tap water alone after BOP initiation. Only the BOP-treated groups developed pancreatic adenocarcinomas and dysplasias. The multiplicity of pancreatic carcinomas was significantly higher (P less than 0.05) in animals receiving caffeine than in the controls. In addition, caffeine treatment slightly increased the incidence of carcinomas. Nicotine and ethanol also showed tendencies to enhance pancreatic carcinogenesis, although there were statistically no significant differences regarding lesion development. In contrast, sodium selenite administration was associated with a tendency for a decrease in the number of carcinomas and dysplasias. Thus, among these chemicals of obvious significance to human life-style, caffeine enhanced the development of pancreatic tumors when administered during the post-initiation phase in this hamster model. 相似文献
19.
K Imaida C Furihata M Tatematsu C H Yoon F Furukawa C Uneyama M Takahashi N Ito Y Hayashi 《Toxicologic pathology》1991,19(3):230-236
Pepsinogens are acid protease enzymes of pepsin usually found in gastric mucosa. In the present study, we demonstrated the presence of pepsinogen isozymes in male Syrian golden hamster lung tissues by a combined immunohistochemical and biochemical approach. Immunohistochemically, using rat pepsinogen 1 antibody, pepsinogen positive cells were observed mainly in the epithelia of the terminal bronchioles. They demonstrated morphological features of Clara cells. The pepsinogen isozyme pattern of lung tissue determined by polyacrylamide gel electrophoresis was similar to that of stomach mucosa. Treatment of hamsters with polychlorinated biphenyls at a dose of 500 mg/kg body weight ip caused a 2.8-fold increase in pepsinogen content (p less than 0.01) as well as increase in numbers of pepsinogen positive cells in the lung. 相似文献
20.
T Kubota H Yamaguchi M Watanabe T Yamamoto T Takahara T Takeuchi T Furukawa S Kase S Kodaira K Ishibiki 《Japanese journal of cancer research》1992,83(3):300-303
We implanted normal peripheral blood lymphocytes (PBL) from healthy donors and splenic tissues from patients with gastric cancers into the severe combined immunodeficient (SCID) mouse, demonstrating that SCID mouse with splenic tissue can produce a high level of human immunoglobulin G (IgG). The normal PBLs at 10(7) and 10(8)/mouse were implanted intraperitoneally, and three splenic tissues with a size of 3 x 3 x 3 mm from gastric cancer patients were inoculated subcutaneously into the bilateral backs of the mice. At 2, 4, 6 and 8 weeks after inoculation, mice were killed, and the human IgG was assessed by an ELISA method. SCID mice with splenic tissue revealed high human IgG levels from 2 weeks after inoculation and approximately 2 mg of IgG per ml was observed at 8 weeks post-implantation, while the IgG levels in mice treated with PBLs were limited. Since the half life of the extrinsic human IgG was 10.2 days, the high level of human IgG in the SCID mice was supposed to be produced by human plasma cells in the splenic tissue from gastric cancer patients. This model was thought to be adequate for evaluating human immunological functions in vivo. 相似文献