全文获取类型
收费全文 | 35870篇 |
免费 | 1852篇 |
国内免费 | 190篇 |
专业分类
耳鼻咽喉 | 307篇 |
儿科学 | 469篇 |
妇产科学 | 507篇 |
基础医学 | 4695篇 |
口腔科学 | 1025篇 |
临床医学 | 2309篇 |
内科学 | 8635篇 |
皮肤病学 | 936篇 |
神经病学 | 2516篇 |
特种医学 | 1551篇 |
外科学 | 6230篇 |
综合类 | 175篇 |
一般理论 | 1篇 |
预防医学 | 1082篇 |
眼科学 | 719篇 |
药学 | 2598篇 |
中国医学 | 66篇 |
肿瘤学 | 4091篇 |
出版年
2023年 | 159篇 |
2022年 | 347篇 |
2021年 | 623篇 |
2020年 | 361篇 |
2019年 | 447篇 |
2018年 | 621篇 |
2017年 | 554篇 |
2016年 | 594篇 |
2015年 | 627篇 |
2014年 | 831篇 |
2013年 | 1097篇 |
2012年 | 1594篇 |
2011年 | 1749篇 |
2010年 | 1035篇 |
2009年 | 926篇 |
2008年 | 1555篇 |
2007年 | 1606篇 |
2006年 | 1629篇 |
2005年 | 1724篇 |
2004年 | 1653篇 |
2003年 | 1619篇 |
2002年 | 1529篇 |
2001年 | 1332篇 |
2000年 | 1347篇 |
1999年 | 1237篇 |
1998年 | 471篇 |
1997年 | 382篇 |
1996年 | 364篇 |
1995年 | 313篇 |
1994年 | 276篇 |
1993年 | 267篇 |
1992年 | 833篇 |
1991年 | 744篇 |
1990年 | 744篇 |
1989年 | 709篇 |
1988年 | 717篇 |
1987年 | 637篇 |
1986年 | 620篇 |
1985年 | 603篇 |
1984年 | 396篇 |
1983年 | 332篇 |
1982年 | 150篇 |
1979年 | 320篇 |
1978年 | 210篇 |
1977年 | 151篇 |
1975年 | 152篇 |
1974年 | 214篇 |
1973年 | 151篇 |
1972年 | 166篇 |
1971年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Toshihiko Imakiire Yuichi Kikuchi Muneharu Yamada Taketoshi Kushiyama Keishi Higashi Naomi Hyodo Kojiro Yamamoto Takashi Oda Shigenobu Suzuki Soichiro Miura 《Hypertension research》2007,30(7):635-642
The mechanisms of hypertensive nephrosclerosis are not fully understood. In experimental models of the disease, inflammatory reactions such as macrophage infiltration play an important role. In human hypertensive nephrosclerosis, however, there have been few studies examining the role of inflammation histologically. We investigated whether the number of infiltrating macrophages was increased in human hypertensive nephrosclerosis, and evaluated the effects of a blockade of the renin-angiotensin system on clinical and histological findings. We examined macrophage infiltration using immunohistochemistry in renal biopsy specimens obtained from 16 patients with hypertensive nephrosclerosis, 5 patients with IgA nephropathy, 5 patients with membranous nephropathy, and 5 patients with minimal change nephrotic syndrome. The number of infiltrating macrophages in glomeruli was significantly larger in the patients with hypertensive nephrosclerosis than in those with minimal change nephrotic syndrome. The patients with hypertensive nephrosclerosis were divided into groups based on their use of antihypertensive agents at the time of renal biopsy. We investigated the effects of antihypertensive agents on clinical findings, macrophage infiltration, and monocyte chemoattractant protein-1 expression. There was no difference in clinical findings between the hypertensive groups. The numbers of infiltrating macrophages and monocyte chemoattractant protein-1-positive cells in glomeruli were significantly smaller in patients treated with an angiotensin-converting enzyme inhibitor or angiotensin II type 1 receptor blocker, whereas calcium channel blockers had no influence on histological findings. In conclusion, inflammation is involved in the progression of human hypertensive nephrosclerosis and the inflammatory process is inhibited by blocking the renin-angiotensin system. 相似文献
52.
Hiroshi Yamamoto Shinji Teramoto Yasuhiro Yamaguchi Yasuyoshi Ouchi 《Hypertension research》2007,30(11):1065-1076
Obstructive sleep apnea syndrome (OSAS) is recognized as one of the risk factors of hypertension and cardiovascular disorders. In the current study, we hypothesized that the hypoxic stress and oxidative stress caused by obstructive sleep apnea would increase circulating adrenomedullin (ADM) levels in untreated OSAS patients as compared to an age and body mass index (BMI)-matched control group and an age-matched, but normal-BMI control group. We further hypothesized that nasal continuous positive airway pressure (nCPAP) treatment may decrease OSAS-induced hypoxic stress, oxidative stress and ADM levels. To examine these hypotheses, we measured circulating ADM and reactive oxygen species (ROS) from leukocytes before and after nCPAP therapy in OSAS patients. The circulating levels of ADM and amount of ROS in untreated OSAS patients were significantly greater than those in the controls. No differences in ADM levels were found between the increased-BMI controls and normal-BMI controls. We observed that nCPAP treatment decreased sleep apneas, nocturnal oxyhemoglobin desaturation, the circulating ADM, and ROS production by leukocytes in OSAS patients. The ADM levels were associated with the magnitude of oxyhemoglobin desaturation rather than the number of sleep apneas. These observations suggest that nCPAP therapy could reduce OSAS-induced nocturnal hypoxemia, generation of ROS, and ADM in patients with OSAS. 相似文献
53.
A pH-sensitive microsphere system for the colon delivery of tacrolimus containing nanoparticles. 总被引:2,自引:0,他引:2
Alf Lamprecht Hiromitsu Yamamoto Hirofumi Takeuchi Yoshiaki Kawashima 《Journal of controlled release》2005,104(2):337-346
Nanoparticles (NP) are known to accumulate at the site of inflammation in inflammatory bowel disease. In order to avoid premature uptake or degradation of NP during their passage through the small intestine, it appeared necessary to devise a form of local delivery system for NP. Tacrolimus (FK506) loaded poly(lactic-co-glycolic acid) NP entrapped into pH-sensitive microspheres (NPMS) were designed to achieve greater selectivity to their site of action when administered orally. The therapeutic efficacy of this drug delivery system was tested in an experimental colitis in rats. The in vitro characterization showed a successful incorporation of FK506-NP and strongly pH-sensitive release kinetics of both NP and drug. During the in vivo studies, clinical activity, colon/body weight index, and myeloperoxidase activity were determined to assess the severity of inflammation. Systemic availability of a fluorescent dye entrapped in the microspheres was measured in order to determine possible adverse effects. The NPMS as well as the controls of NP and MS formulations exhibited significant mitigating effects in the clinical activity index after 3 days of treatment with similar levels for the various therapies. When observing colon/body weight index and myeloperoxidase activity, only the NPMS group reached statistically significant differences (P<0.05) compared to the colitis control group while other groups did not (colitis control: 21.94+/-4.97; FK506 solution: 15.81+/-3.42; FK506-NP: 17.03+/-5.52; FK506-MS: 15.17+/-7.81; and FK-NPMS: 10.26+/-7.76 U/mg tissue). Moreover, the NPMS system reduced the systemic absorption of the entrapped dye compared to the dye solution or simple NP formulation (relative biovailability-solution: 100+/-14.9%; NP: 46.8+/-8.6%; and NPMS: 29.4+/-3.3%). The results suggest that the NPMS system can provide selective delivery of NP in the colon and develop a significant mitigating effect, while the control group treatments appeared to be insufficient. 相似文献
54.
Shoko Nakajima Hiroaki Umebayashi Rumiko Kurosawa Tomoyuki Imagawa Shigeki Katakura Masaaki Mori Yuko Aihara Shumpei Yokota Tuyoshi Sogo Ayano Inui Tomoo Fujisawa Norio Hanzawa 《Nihon Rinshō Men'eki Gakkai kaishi》2005,28(3):154-158
A 10-year-old girl with autoimmune hepatitis (AIH) was reported. She was admitted to our hospital because of cholestasis and elevation of liver enzymes for 2 months. Laboratory examination revealed that EBV-DNA copy number in the PBMNC (peripheral mononuclear cells) was 1.2 x 10(3) copies/microg of DNA, hypergammaglobulinemia, and positive antinuclear antibody, positive anti-smooth muscle antibody. The histology of her liver biopsy specimen revealed interface hepatitis, dense mononuclear cell infiltrates, mild fibrosis, and negative for EBV in situ hybridization assay indicating AIH and not EBV-associated hepatitis. She was treated firstly with methylprednisolone pulses, then will prednisolone p.o.+azathioprine p.o.. Intravenous cyclophosphamide pulse therapy was introduced because of her abnormal immune pathology. All abnormal laboratory parameters improved to normal levels within 2 months, and EBV-DNA copy number in the PBMNC became negative after 4 months. The histology of liver biopsy specimen was useful for the diagnosis of AIH in such a difficult case needed to be differentiated from EBV hepatitis. 相似文献
55.
56.
Yusen Chen Jun Nakura Jing-Ji Jin Zhihong Wu Miyuki Yamamoto Michiko Abe Yasuharu Tabara Yoshikuni Yamamoto Michiya Igase Xiao Bo Katsuhiko Kohara Tetsuro Miki 《Hypertension research》2003,26(6):439-444
The beta-adrenoceptor (beta-AR)-stimulatory guanine nucleotide-binding (Gs) protein system has been shown to play important roles in the cardiovascular system. The gene encoding the alpha-subunit of Gs proteins (GNAS1) is a candidate genetic determinant for hypertension. Because alcohol consumption is known to affect blood pressure partly through the beta-AR-Gs protein system, we examined the possible interaction between GNAS1 T393C polymorphism and drinking status in the association with hypertension in the present study. As a result, a non-significant but reasonable trend supporting the presence of an interaction was shown (p = 0.076). In line with this trend, the T393C polymorphism significantly interacted with drinking status in the association with systolic blood pressure (p = 0.028). Moreover, supporting the presence of an interaction, T allele carriers consistently had a higher probability of hypertension, higher systolic blood pressure, and higher diastolic blood pressure than CC homozygotes in non-drinkers and light drinkers. In contrast, CC homozygotes consistently had a higher probability of hypertension, higher systolic blood pressure, and higher diastolic blood pressure than T allele carriers in moderate to heavy drinkers. The present study also showed a significant interaction between the T393C polymorphism and drinking status in the association with pulse pressure (p = 0.026), reflected by a significant association between the T393C polymorphism and pulse pressure in moderate to heavy drinkers (p = 0.026). These findings may be helpful in conducting further molecular and biological studies on the relationship among the effects of alcohol, the beta-AR-Gs protein system, and hypertension. 相似文献
57.
58.
59.
Kazuo Yamakawa Masashi Takanashi Masao Watanabe Noriyuki Nakamura Tomonori Kobayashi Masato Hasegawa Yoshikuni Mizuno Shigeki Tanaka Hideo Mori 《Neuropathology》2006,26(6):586-591
We report on a male patient with Pick disease who had shown severe white matter atrophy and dilatation of the lateral ventricle in the frontal lobe from an early stage. Upon admission to our hospital 2 years after disease onset, the patient showed apathy, and MRI revealed severe atrophy of the cortex and white matter of the frontal lobe. He died at age 74, 11 years after disease onset. Autopsy revealed severe atrophy of the frontal and temporal lobes, severe loss of white matter in the frontal lobe, dilatation of the lateral ventricles, and cortical thinning. Histopathological examination showed severe loss of myelinated fibers in the frontal white matter and severe neuronal loss with gliosis in the frontal and temporal cortices. Many Pick bodies were seen. Our patient had a rare case of Pick disease predominantly affecting the frontal lobe with severe involvement of the white matter from an early stage. This case suggests that myelinated fibers in the white matter as well as cerebral neurons are primarily affected in Pick disease. 相似文献
60.
Hidehito Sakaguchi Tetsuji Kawata Shigeki Taniguchi 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2004,52(2):71-74
The surgical approach to ischemic mitral regurgitation with concomitant inferior left ventricular aneurysm remains uncertain
in terms of the indication for operation and the short-and long-term outcomes. We performed concomitant mitral valve repair,
left ventricular reconstruction, and aortic valve replacement on a 71-year-old male with severe ischemic mitral regurgitation,
inferior left ventricular aneurysm, and degenerative aortic regurgitation. Postoperative status was in New York Heart Association
functional class I without mitral regurgitation 8 months after operation. We discuss, and review the procedures reported in
the literature. 相似文献