首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1453篇
  免费   92篇
  国内免费   9篇
医药卫生   1554篇
  2023年   11篇
  2022年   6篇
  2021年   39篇
  2020年   16篇
  2019年   22篇
  2018年   39篇
  2017年   22篇
  2016年   36篇
  2015年   36篇
  2014年   47篇
  2013年   54篇
  2012年   129篇
  2011年   123篇
  2010年   62篇
  2009年   57篇
  2008年   97篇
  2007年   119篇
  2006年   90篇
  2005年   84篇
  2004年   84篇
  2003年   94篇
  2002年   101篇
  2001年   12篇
  2000年   6篇
  1999年   8篇
  1998年   20篇
  1997年   14篇
  1996年   14篇
  1995年   10篇
  1994年   8篇
  1993年   8篇
  1992年   8篇
  1991年   10篇
  1990年   2篇
  1989年   9篇
  1988年   5篇
  1987年   4篇
  1986年   2篇
  1985年   6篇
  1984年   5篇
  1983年   5篇
  1982年   6篇
  1981年   8篇
  1980年   5篇
  1979年   4篇
  1976年   2篇
  1975年   1篇
  1974年   1篇
  1972年   1篇
  1958年   1篇
排序方式: 共有1554条查询结果,搜索用时 62 毫秒
1.
2.
1. Endothelium-dependent relaxation in response to acetylcholine (ACh) and the calcium ionophore A 23187 was examined in aorta, coronary, basilar and renal arteries isolated from Watanabe heritable hyperlipidaemic (WHHL) rabbits of 2, 6 and 12 months of age, with normolipidaemic heterozygous WHHL rabbits as controls. 2. In the rings of WHHL rabbit aortae and coronary arteries preconstricted with vasoconstrictors, endothelium-dependent relaxation in response to ACh was attenuated with age compared to the heterozygous WHHL rabbits. A significant negative correlation was found between the total cholesterol content and the relaxation response to ACh in the aortae or coronary arteries from 6 and 12 month old WHHL rabbits. 3. In the rings of basilar arteries, endothelium-dependent relaxations to ACh were not modified with age. Similarly, in the rings of renal arteries, the relaxation response to ACh was not changed with age, but in the 6 and 12 month preparations, after the age of 6 months, a contraction following the relaxation appeared at higher concentrations of ACh (10?7 to 10?6 mol/L). The contraction was endothelium-dependent and inhibited by indomethacin. 4. A 23187-induced endothelium-dependent relaxations were also markedly attenuated in the aorta and significantly in the coronary artery with age. 5. Endothelium-independent relaxation to sodium nitroprusside was not changed in all arteries from WHHL rabbits of different ages. 6. These findings indicate that in the aorta and coronary artery of the WHHL rabbit, the endothelium-dependent relaxation to ACh and A 23187 becomes impaired with increasing age (i.e., with the progression of cholesterol deposition in the arterial wall) but is preserved in the basilar and renal artery.  相似文献   
3.
The modifying potential of two nephrotoxic agents, harman and norharman, on N-ethyl-N-hydroxyethylnitrosamine (EHEN)-induced renal and hepatic carcinogenesis was investigated in male F344/DuCrj rats. Animals were given 0.1% EHEN in their drinking water for the first 2 weeks as an initiator. Subsequently, starting 3 weeks from the commencement, they were fed diet containing these compounds at concentrations of 1000, S00 or 0 ppm until week 26, and then killed for light microscopic examination. The mean numbers of renal tubular cell hyperplasias/cm2 and those of tumors/cm2 in rats given harman and norharman at 1000 ppm after initiation, but not at 500 ppm, were significantly increased as compared to the control values. However, neither compound modified liver carcinogenesis. It is concluded that harman and norharman show enhancing effects on rat kidney carcinogenesis, when ingested at dose levels which cause renal tubular damage.  相似文献   
4.
A 80-year old man was referred to our hospital because of an elevation of serum amylase level. Diffuse enlargement of the pancreas was detected by abdominal computed tomography, and also diffuse narrowing of the main pancreatic duct was revealed using endoscopic retrograde cholangiopancreatography. The serum level of IgG was elevated to 3450mg/dl. Besides, on the 10th hospital day, petechia developed and the platelet level decreased to 1.5 x 10(4)/microl. The platelet-associated IgG, antiplatelet antibody and antinuclear antibody in serum were positive. The levels of serum complements were low. From all these findings the patient was diagnosed as autoimmune pancreatitis complicated with immune thrombocytopenia. The treatment with prednisolone was started, which was effective on each disease. The medication was suspended a year ago, and so far there is no data suggesting the recurrence of autoimmune pancreatitis or immune thrombocytopenia.  相似文献   
5.
A 58-year-old woman suffered from stiffness, swelling, rubor and muscle pain in the extremities one month after she climbed a mountain in Kyushu, an island in southern Japan. On admission, mild proximal weakness was present in the extremities. Her range of motion in the extremities was limited due to firm skin and subcutaneous stiffness which was similar to scleroderma. She showed peripheral blood eosinophilia and hypergammaglobulinemia as well as a high erythrocyte sedimentation rate. An IgM antibody against Borrelia afzelii was positive. MRI of the skeletal muscles demonstrated enhancing fascia around the biceps brachii muscle, and a biopsy specimen revealed perivascular infiltration of mononuclear cells within the hypertrophic fascia. Eosinophilic infiltration was absent. We treated the patient with prednisolone, doxycycline and amoxicillin, which alleviated the symptoms. This is the first report to show that Borrelia afzelii was involved in eosinophilic fasciitis.  相似文献   
6.
Gambierol was isolated from Gambierdiscus toxicus, which causes ciguatera fish poisoning. The acute toxicological effects induced in mice by synthesized gambierol were studied. The lethal doses were about 80 μg/kg by i.p. and i.v., and 150 μg/kg by p.o. The main injury by this toxin was observed in the lung, and secondary in the heart, resulting in systemic congestion. Another toxic effect was seen in the stomach, inducing hypersecretion and ulceration. With survival from the severe stage during the initial 3 h, recovery was favorable, especially after 4 days. Additional effects were not evident during 1-week post-administration observation.  相似文献   
7.
Heart lesions of rheumatic heart disease (RHD) patients contain T-cell clones that recognize heart proteins and streptococcal M peptides. To functionally characterize heart-infiltrating T lymphocytes, we evaluated their cytokine profile, both directly in situ and in T-cell lines derived from the heart (HIL). Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-10 expressions were characterized in 20 heart tissue infiltrates from 14 RHD patients by immunohistochemistry. IFN-gamma-, TNF-alpha-, and IL-10-positive cells were consistently predominant, whereas IL-4 was scarce in the valves. In agreement with these data, the in vitro experiments, in which 13 HILs derived from heart samples of eight patients were stimulated with M5 protein and the immunodominant M5 (81-96) peptide, IL-4 was detected in HIL derived from the atrium (three of six) but not from the valve (zero of seven). IFN-gamma and IL-10 production were detected in culture supernatants in 11 of 13 and 6 of 12 HILs, respectively. The predominant IFN-gamma and TNF-alpha expression in the heart suggests that Th1-type cytokines could mediate RHD. Unlike in reversible myocardium inflammation, the significantly lower IL-4 expression in the valvular tissue (P = 0.02) may contribute to the progression of the RHD leading to permanent valvular damage (relative risk, 4.3; odds ratio, 15.8). The lack of IL-4 in vitro production by valve-derived HIL also emphasizes the more severe tissue destruction in valves observed in RHD.  相似文献   
8.
BACKGROUND: Recently, it is recognized that the patients of oral allergy syndrome (OAS) to fruits are increasing. However, there are little knowledges of the background, character, and seriousness about these patients in Kanto regions. OBJECTIVE: We aimed to investigate the clinical features of OAS patients to plant origin foods in Kanto regions. METHODS: The patient, who visited Sagamihara National Hospital from 2000 to 2005 and developed some allergic symptoms to plant origin foods, were studied by a questionary survey. RESULTS: As for the 42 subjects, average age are 36 years old, male:female=8:34, merger of other allergic disease is 35 allergic rhinitis of 42 subjects (83%), 34 of asthma (81%), 14 of atopic dermatitis (33%). The causes of OAS symptoms are 32 rose-family fruits, 34 non-rose family fruits, 14 vegetables, 11 nuts, 2 grains subjects. As for the symptom, only in the oral and pharynx symptoms are found in 12, the systemic symptoms is 29, anaphylaxis is 11 subjects. Allergic rhinitis preceded on the 90% subjects with pollinosis, very high rate. On the other hand, the 20% of all subjects have no symptoms of allergic rhinitis. CONCLUSION: A nasal catarrh symptoms went ahead in most of the OAS subjects in Kanto regions. In addition, considering from some patients have no black alder pollinosis and/or are allergic to many non-rose-family fruits at high frequency, there might be a broad cross-reactivity between many pollens other than alder and plant origin foods.  相似文献   
9.
10.
Helicobacter pylori induces severe neutrophilic infiltration in the lamina propria of the stomach, which leads to gastritis in humans. The possible involvement of a paracellular route for bacterial nutrients and etiologic agents that may play an important role in colonization of the bacteria and cause gastritis has been suggested. To study the functions of the paracellular barrier of gastric surface epithelium, SS1, a strain of H. pylori adapted to the murine stomach, was inoculated into the stomachs of C57BL/6 mice. At 4 months after inoculation, SS1 had achieved a high level of colonization (10(6)-10(7) colony-forming units/g tissue) associated with neutrophilic infiltration in the lamina propria of the junctional zone. Disruption of the paracellular barrier was observed in the SS1-infected stomachs, as revealed by the invasion of a lanthanum tracer into the paracellular space of the surface epithelium. Only 2% of junctions were permeable in control stomachs, whereas 72% of the paracellular barrier was disrupted in the SS1-infected gastric epithelia. Furthermore, distribution of tight junction-related molecules such as 7H6 antigen, occludin, and cortical actin was affected in the surface epithelium by SS1 infection. The linear expression pattern of occludin was disrupted and became irregular or punctuated. The 7H6 antigen accumulated as aggregates in the apical portion of the surface epithelium and cortical actin became irregular and punctuated. Taken together, these results indicate that infection by SS1 directly or indirectly caused an increase in paracellular permeability and altered the localization of tight junction-related molecules of the gastric surface epithelium. This observation suggests that the paracellular pathway may play a significant role in establishing H. pylori-induced gastritis in the clinical setting.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号