全文获取类型
收费全文 | 1853篇 |
免费 | 77篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 49篇 |
妇产科学 | 9篇 |
基础医学 | 199篇 |
口腔科学 | 62篇 |
临床医学 | 133篇 |
内科学 | 771篇 |
皮肤病学 | 9篇 |
神经病学 | 95篇 |
特种医学 | 27篇 |
外科学 | 278篇 |
综合类 | 7篇 |
一般理论 | 1篇 |
预防医学 | 36篇 |
眼科学 | 5篇 |
药学 | 142篇 |
中国医学 | 2篇 |
肿瘤学 | 132篇 |
出版年
2023年 | 7篇 |
2022年 | 9篇 |
2021年 | 22篇 |
2020年 | 13篇 |
2019年 | 23篇 |
2018年 | 19篇 |
2017年 | 22篇 |
2016年 | 33篇 |
2015年 | 25篇 |
2014年 | 37篇 |
2013年 | 54篇 |
2012年 | 91篇 |
2011年 | 120篇 |
2010年 | 55篇 |
2009年 | 45篇 |
2008年 | 94篇 |
2007年 | 112篇 |
2006年 | 129篇 |
2005年 | 131篇 |
2004年 | 120篇 |
2003年 | 125篇 |
2002年 | 118篇 |
2001年 | 60篇 |
2000年 | 62篇 |
1999年 | 55篇 |
1998年 | 36篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 21篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 34篇 |
1991年 | 21篇 |
1990年 | 20篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 16篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1974年 | 5篇 |
1972年 | 3篇 |
1969年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有1959条查询结果,搜索用时 0 毫秒
41.
Sumino H Ichikawa S Miya Y Sakamaki T Kurabayashi M 《American journal of hypertension》2005,18(10):1340-1346
BACKGROUND: We investigated the role of angiotensin (Ang) II in maintaining blood pressure (BP) by administering a small dose of candesartan, an Ang II type 1 receptor antagonist, in postmenopausal women receiving long-term hormone replacement therapy (HRT). METHODS: A single dose of 2 mg of candesartan was administered orally to 13 normotensive postmenopausal women receiving HRT (continuous combined conjugated estrogen and medroxyprogesterone acetate orally; HRT group) and 13 normotensive postmenopausal women not receiving HRT (control group). Both BP and heart rate (HR) were measured at baseline and at 1, 2, 3, 4, 5, and 6 h after administration. Plasma renin activity (PRA) and Ang I, Ang II, and bradykinin concentrations were measured at baseline and 4 h after the administration of candesartan. RESULTS: Candesartan lowered the BP and raised the HR in both groups. However, the decrease in BP was significantly greater in the HRT group than in the control group (P < .05), whereas no significant difference in the change in HR was observed between the two groups. In the HRT group, significant increases were found in PRA, Ang I, and Ang II (all P < .05) and a significant decrease in bradykinin (P < .01) with candesartan treatment. In the control group, candesartan as associated with an increase in PRA (P < .05) but not in Ang I, Ang II, or bradykinin. CONCLUSIONS: Based on our study results, Ang II plays an important role in maintaining BP in normotensive postmenopausal women receiving HRT. Maintenance of BP may be dependent on the balance between the hypertensive effect of Ang II and the hypotensive effect of bradykinin. 相似文献
42.
M Murakami H Suzuki H Nakamoto Y Kageyama M Naitoh Y Sakamaki T Saruta 《Acta endocrinologica》1991,124(3):346-352
The effects of a small dose (2 pmol/kg) of human calcitonin gene-related peptide I on plasma renin activity and hormones, including, aldosterone, ACTH, cortisol, AVP and ANH, were investigated in 14 conscious dogs. In addition, we studied the effects of calcitonin gene-related peptide on aldosterone secretion when it is stimulated by angiotensin II and ACTH. An intravenous bolus injection of 2 pmol/kg of calcitonin gene-related peptide raised plasma renin activity (by 216%, p less than 0.05), ACTH (by 85%, p less than 0.05), AVP (by 89%, p less than 0.05), and ANH (by 36%, p less than 0.05). Despite the elevation of plasma renin activity, aldosterone was decreased (by 52%, p less than 0.05). Cortisol did not change significantly. Infusion of 1 pmol.kg-1.min-1 of angiotensin II produced an elevation of aldosterone (by 186%, p less than 0.01), which was completely inhibited by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. On the other hand, aldosterone secretion stimulated by ACTH was not altered significantly by pretreatment with an injection of 2 pmol/kg of calcitonin gene-related peptide. These results suggest that calcitonin gene-related peptide inhibits aldosterone secretion, especially when aldosterone is stimulated by angiotensin II. In addition, calcitonin gene-related peptide may be involved as an endocrine modulator in the physiological control of other several hormones closely related to the hemodynamics. 相似文献
43.
44.
BACKGROUND: Cardiac and systemic autonomic nervous function may be impaired in patients with COPD. Few reports, however, have described sympathetic nervous function of the left ventricle (LV) in COPD patients. STUDY OBJECTIVE: To assess the LV sympathetic nervous function in patients with COPD using (123)I-metaiodobenzylguanidine (MIBG) imaging of the heart. DESIGN: Prospective comparison of (123)I-MIBG imaging results in COPD patients and normal subjects. PARTICIPANTS: Twenty-eight patients with COPD without manifest right ventricular overload and 7 volunteers without cardiopulmonary disease (control subjects). MEASUREMENTS: (123)I-MIBG imaging results and plasma norepinephrine concentration were compared between the COPD and control groups. In the COPD group, pulmonary function tests were performed and all subjects were interviewed about their symptoms. RESULTS: (123)I-MIBG uptake, assessed as the cardiac to mediastinal activity ratio in the delayed image, was significantly lower in the COPD group than in the control group (p < 0.05). (123)I-MIBG turnover, expressed as the washout rate (WR) of (123)I-MIBG from 15 to 240 min, was significantly higher in the COPD group than in the control group (p < 0.01). In the COPD group, patients with dyspnea showed lower cardiac to mediastinal activity ratios and higher WRs compared with patients who had mild dyspnea. The WR correlated negatively with the vital capacity/predicted value ratio, correlated negatively with the maximal voluntary ventilation volume/predicted value ratio, and correlated positively with the residual volume/total lung capacity ratio in the COPD group. The plasma norepinephrine concentration in COPD patients was higher than that in the control subjects. CONCLUSION: Patients with COPD have significant sympathetic nervous impairment of the LV myocardium as a result of generalized sympathetic overactivity. 相似文献
45.
46.
Yoshifumi Nishi Chika Ogami Yasuhiro Tsuji Hitoshi Kawasuji Harumi Yamada Shin Kawai Ippei Sakamaki Hideto To Yoshihiro Yamamoto 《Journal of infection and chemotherapy》2021,27(2):165-171
IntroductionAims of this study were (a) to assess the development ratio of hyponatremia during treatment with linezolid and (b) to evaluate the relationship between the risk of hyponatremia and linezolid exposure and patient background.MethodClinical data including linezolid serum concentrations and serum sodium values were collected at Toyama University Hospital and Kyorin University Hospital. Data from 89 patients were used for the analysis, and a nadir serum sodium level ≤130 mmol/L during the treatment with linezolid was defined as hyponatremia. Mann-Whitney's U test was used to evaluate the effects of the area under the time-concentration curve (AUC) of linezolid at the nadir sodium level, clinical characteristics (e.g. laboratory data), and baseline serum sodium levels on the development of hyponatremia.ResultsThe hyponatremia was occurred in 21 of 89 patients (23.6%). Data are compared for baseline and nadir serum sodium levels of patients with and without hyponatremia. In both groups, nadir serum sodium levels were significantly different from those of the baseline values (P < 0.05). The values of AUC0-12, accumulated AUC, baseline serum sodium levels and age were significantly different between patients with and without hyponatremia (P < 0.05).ConclusionsLinezolid exposure, age, and baseline sodium levels were detected as the risk factors for linezolid-related hyponatremia. Our findings suggest that regular monitoring of serum sodium levels is desirable during treatment with linezolid, especially for the elderly and patients with low serum sodium levels before the start of linezolid administration. 相似文献
47.
Sleep-related disordered breathing (SDB) and its influence on desaturation were examined in stable COPD patients with waking SpO2 > 90%. With respiratory inductance plethysmography, thoracic-abdominal respiratory movements for all events with more than 4% desaturation were analyzed in 26 patients. Types of SDB were confirmed by full polysomnography. Irregular breathing induced desaturation, while stable respiration continued during some desaturation events. Three types of altered ventilation were observed: hypoventilation, paradoxical movement and periodic breathing. An unusual type of paradoxical movement, with normal airflow despite progressive desaturation, was observed in REM sleep. Patients were divided into desaturation (15 patients) and non-desaturation (11 patients) groups. Daytime arterial blood gas, lung function values, and 6-min walking distance did not differ. Awake, mode, maximum and minimum nocturnal SpO2 were lower in the desaturation group. SDB-induced desaturation events in the desaturation group were more frequent (9.2+/-3.5 vs. 1.8+/-2.2 times), a greater SpO2 decrease (11.4+/-7.1% vs. 5.2+/-2.1%) and longer duration (73.2+/-34.8 vs. 18.8+/-39.0 min). Patterns of SDB in the desaturation group were hypoventilation (74.4+/-23.4%), paradoxical movement (10.2+/-14.5%), periodic breathing (12.1+/-18.3%) and unclassified (5.8+/-11.2%). These results reveal that lower SpO2 and SDB influence nocturnal desaturation in stable COPD patients. 相似文献
48.
Development and internal validation of a nomogram for predicting stone‐free status after flexible ureteroscopy for renal stones 下载免费PDF全文
49.
50.