全文获取类型
收费全文 | 2468篇 |
免费 | 107篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 52篇 |
妇产科学 | 7篇 |
基础医学 | 257篇 |
口腔科学 | 107篇 |
临床医学 | 136篇 |
内科学 | 665篇 |
皮肤病学 | 41篇 |
神经病学 | 74篇 |
特种医学 | 89篇 |
外科学 | 531篇 |
综合类 | 8篇 |
预防医学 | 106篇 |
眼科学 | 26篇 |
药学 | 176篇 |
中国医学 | 4篇 |
肿瘤学 | 267篇 |
出版年
2023年 | 10篇 |
2022年 | 22篇 |
2021年 | 36篇 |
2020年 | 13篇 |
2019年 | 23篇 |
2018年 | 29篇 |
2017年 | 39篇 |
2016年 | 34篇 |
2015年 | 54篇 |
2014年 | 80篇 |
2013年 | 81篇 |
2012年 | 146篇 |
2011年 | 176篇 |
2010年 | 88篇 |
2009年 | 93篇 |
2008年 | 151篇 |
2007年 | 187篇 |
2006年 | 184篇 |
2005年 | 203篇 |
2004年 | 166篇 |
2003年 | 179篇 |
2002年 | 177篇 |
2001年 | 48篇 |
2000年 | 34篇 |
1999年 | 41篇 |
1998年 | 32篇 |
1997年 | 25篇 |
1996年 | 16篇 |
1995年 | 13篇 |
1994年 | 21篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 19篇 |
1990年 | 11篇 |
1989年 | 23篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1974年 | 2篇 |
1971年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有2591条查询结果,搜索用时 15 毫秒
41.
Duck O. Kim Brian Bishop Shigeyuki Kuwada 《Journal of the Association for Research in Otolaryngology》2010,11(4):541-557
There are numerous studies measuring the transfer functions representing signal transformation between a source and each ear
canal, i.e., the head-related transfer functions (HRTFs), for various species. However, only a handful of these address the
effects of sound source distance on HRTFs. This is the first study of HRTFs in the rabbit where the emphasis is on the effects
of sound source distance and azimuth on HRTFs. With the rabbit placed in an anechoic chamber, we made acoustic measurements
with miniature microphones placed deep in each ear canal to a sound source at different positions (10–160 cm distance, ±150°
azimuth). The sound was a logarithmically swept broadband chirp. For comparisons, we also obtained the HRTFs from a racquetball
and a computational model for a rigid sphere. We found that (1) the spectral shape of the HRTF in each ear changed with sound
source location; (2) interaural level difference (ILD) increased with decreasing distance and with increasing frequency. Furthermore,
ILDs can be substantial even at low frequencies when distance is close; and (3) interaural time difference (ITD) decreased
with decreasing distance and generally increased with decreasing frequency. The observations in the rabbit were reproduced,
in general, by those in the racquetball, albeit greater in magnitude in the rabbit. In the sphere model, the results were
partly similar and partly different than those in the racquetball and the rabbit. These findings refute the common notions
that ILD is negligible at low frequencies and that ITD is constant across frequency. These misconceptions became evident when
distance-dependent changes were examined. 相似文献
42.
Shigeyuki Ebara Mikio Marumo Jun Mukai Makoto Ohki Kagehiro Uchida Ichiro Wakabayashi 《Journal of thrombosis and thrombolysis》2018,45(2):200-205
Although oxidization of LDL is known to be a crucial step for atherosclerotic progression, the significance of oxidized HDL remains to be clarified. The purpose of this study was to determine the relationships of oxidized HDL with blood coagulation and fibrinolysis in patients with diabetes. The subjects were outpatients with type 2 diabetes (n?=?163; median hemoglobin A1c, 6.9%). Activities of blood coagulation and fibrinolysis were evaluated by levels of thrombin–anti-thrombin complex (TAT) and plasmin–α2 plasmin inhibitor complex (PIC), respectively. Relationships of oxidized HDL with TAT and PIC were investigated by using linear regression analysis and logistic regression analysis. Oxidized HDL showed a significant inverse correlation with TAT and a marginally significant correlation with PIC (Spearman’s rank correlation coefficient: TAT, ??0.205 [p?<?0.01]; PIC, ??0.135 [p?=?0.087]). Prevalence of high TAT was significantly lower in the 3rd tertile group for oxidized HDL than in its 1st tertile (20.4 vs. 5.6%, p?<?0.05), and prevalence of high PIC was marginally significantly lower in the 3rd tertile group for oxidized HDL than in its 1st tertile (40.7 vs. 24.1%, p?=?0.099). In multivariate logistic regression analysis using age, gender, smoking, alcohol drinking, BMI, hemoglobin A1c, therapy for dyslipidemia, therapy for diabetes and anti-coagulation therapy as explanatory variables, odds ratios for high TAT and high PIC in the 3rd tertile group for oxidized HDL versus its 1st tertile group were significantly lower than the reference level of 1.00 (high TAT: 0.19 [0.04–0.99], p?<?0.05; high PIC: 0.33 [0.12–0.95], p?<?0.05). The frequency of high TAT or high PIC was lower in the higher tertile group for oxidized HDL than in its lower tertile group. Thus, oxidized HDL is thought to be inversely associated with both blood coagulation and fibrinolysis in patients with type 2 diabetes. 相似文献
43.
Yamagishi H Koike T Ohara S Kobayashi S Ariizumi K Abe Y Iijima K Imatani A Inomata Y Kato K Shibuya D Aida S Shimosegawa T 《World journal of gastroenterology : WJG》2008,14(9):1358-1364
AIM:To examine the prevalence of gastroesophageal reflux disease (GERD) symptoms in a large unselected general population in Japan.
METHODS: In Japan, mature adults are offered regular check-ups for the prevention of gastric cancer. A notice was sent by mail to all inhabitants aged 〉 40 years. A total of 160 983 Japanese (60 774 male, 100 209 female; mean age 61.9 years) who underwent a stomach check up were enrolled in this study. In addition, from these 160 983 subjects, we randomly selected a total of 82 894 (34 275 male, 48 619 female; mean age 62.4 years) to evaluate the prevalence of abdominal pain. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a 1 mo period.
RESULTS: The respective prevalences of the symptoms in males and females were: heartburn, 15.8% vs 20.7%; dysphagia, 5.4% vs 7.8%; and abdominal pain, 6.6% vs 9.6%. Among these symptoms, heartburn was significantly high compared with the other symptoms, and the prevalence of heartburn was significantly more frequent in females than in males in the 60-89-year agegroup. Dysphagia was also significantly more frequent in female patients.
CONCLUSION: The prevalence of typical GERD symptoms (heartburn) was high, at about 20% of the Japan population, and the frequency was especially high in females in the 60-89 year age group. 相似文献
METHODS: In Japan, mature adults are offered regular check-ups for the prevention of gastric cancer. A notice was sent by mail to all inhabitants aged 〉 40 years. A total of 160 983 Japanese (60 774 male, 100 209 female; mean age 61.9 years) who underwent a stomach check up were enrolled in this study. In addition, from these 160 983 subjects, we randomly selected a total of 82 894 (34 275 male, 48 619 female; mean age 62.4 years) to evaluate the prevalence of abdominal pain. The respective subjects were prospectively asked to complete questionnaires concerning the symptoms of heartburn, dysphagia, and abdominal pain for a 1 mo period.
RESULTS: The respective prevalences of the symptoms in males and females were: heartburn, 15.8% vs 20.7%; dysphagia, 5.4% vs 7.8%; and abdominal pain, 6.6% vs 9.6%. Among these symptoms, heartburn was significantly high compared with the other symptoms, and the prevalence of heartburn was significantly more frequent in females than in males in the 60-89-year agegroup. Dysphagia was also significantly more frequent in female patients.
CONCLUSION: The prevalence of typical GERD symptoms (heartburn) was high, at about 20% of the Japan population, and the frequency was especially high in females in the 60-89 year age group. 相似文献
44.
Koyama M Takeshita Y Sakata A Sawada A Yasui M Okamura T Inoue M Kawa K 《International journal of hematology》2005,82(5):437-440
Recent findings indicate that Epstein-Barr virus (EBV)-infected T-/natural killer (NK) cells play an important role in the pathogenesis of mosquito allergy, and most patients with mosquito allergy die early in life if not properly treated. Over the last 7 years, we have been using combination chemotherapy and allogeneic stem cell transplantation for the treatment of EBV-associated T-/NK cell lymphoproliferative disease (LPD) in which chronic active EBV infection and mosquito allergy were included. As of this writing, we have successfully treated 2 patients with mosquito allergy with chemotherapy in which EBV-infected T-/NK cells were eradicated. The findings suggest the possible role of chemotherapy in the treatment of EBV-associated T-/NK cell LPD. 相似文献
45.
Hideo Nishikawa Shigesaburo Miyakoshi Shigeyuki Nishimura Akira Seki Kazuho Honda 《Heart and vessels》1989,5(1):54-58
Summary Primary tumor of the aorta is extremely rare. An instance of aortic intimal sarcoma, namely fibromyxosarcoma, which extended from the beginning of the descending aorta to 7 cm above the abdominal bifurcation, with clinical evidence of acutely occurring hypertension, arterial embolism of the lower extremities, renal infarction, and aortic occlusion in a 50-year-old male is reported. The tumor was limited to the intima and composed of spindle-shaped tumor cells with abundant myxoid extracellular matrices. The tumor cells were negative for Factor VIII, Desmin, or Myoglobin, but were positive for Vimetin or Factor XIIIa in immunoperoxidase studies. An electron microscopic examination revealed a large amount of rough endoplasmic reticulum in the cytoplasm. Parenchymal metastases were observed in both the lungs and thoracic vertebrae. A review of literature on the clinical and pathological aspects of the tumor was made. 相似文献
46.
Mukaisho K Kurumi Y Sugihara H Naka S Kamitani S Tsubosa Y Moritani S Endo Y Hanasawa K Morikawa S Inubushi T Hattori T Tani T 《Digestive diseases and sciences》2002,47(11):2441-2445
We report on a case of metastatic adenocarcinoma of liver that was removed and examined histochemically after microwave coagulation therapy (MCT). The patient was a 65-year-old woman who had a metastatic tumor in the liver (S3) after high anterior resection due to a rectal adenocarcinoma and received MCT against the tumor. One month after MCT, multiple metastatic tumors were detected by abdominal computed tomography (CT) scan. As it was difficult to control them by MCT alone, we performed lateral segmentectomy. To assess the effects of microwave ablation on cellular viability of metastatic tumor, we used enzyme histochemistry for acid phosphatase (AcP), which is positive in macrophages infiltrating in the tumor. In a part of the ablated area of resected liver, there was remaining neoplastic tissue of which the morphology was maintained in H&E staining. This was found to be microwave-fixed non-viable tissue because no enzyme activity of AcP was detected in the infiltrating macrophages. This case report suggests that enzyme histochemistry was useful to assess the effect of MCT, enabling us to distinguish fixed cells from viable cells. 相似文献
47.
Nakashima D Kojima S Nakaboh A Shinozuka T Hasegawa K Nakagawa A Hamada H 《International journal of cardiology》2008,125(3):e51-e53
Thiazolidinediones (TZDs) represent insulin-sensitizing agents that have several pleiotropic properties, possibly related to their favorable effects on cardiovascular remodeling. We briefly describe 2 diabetic patients who experienced a remarkable improvement in their paroxysmal atrial fibrillation (AF) after treatment with rosiglitazone. Current evidence suggests that atrial remodeling represents a prominent mechanism of AF development and perpetuation while inflammation and oxidative stress are possibly implicated in this process. It could therefore be speculated that the pleiotropic effects of TZDs favorably affect atrial remodeling reducing the arrhythmia burden. Further studies are needed in order to elucidate the merit of this pharmacological approach in AF. 相似文献
48.
Mannoor MK Vanisaveth V Keokhamphavanh B Toma H Watanabe H Kobayashi J Hatabu T Taguchi N Hongvangthong B Phetsouvanh R Phompida S Kano S Sato Y 《The Southeast Asian journal of tropical medicine and public health》2005,36(5):1092-1095
A 28-day in vivo treatment trial to evaluate the efficacy of pyrimethamine/sulfadoxine (Fansidar, PS) was conducted in 21 Lao patients with uncomplicated Plasmodium falciparum malaria. Sixteen patients (76%) were completely cured with PS without any reappearance of asexual stage parasitemia during the follow-up examination. On the other hand, 5 patients (24%) failed to respond to this trial medication, resulting in recrudescence of asexual stage P. falciparum malaria. PS resistance resulted in higher prevalence of post-treatment gametocytemia, 25% gametocyte carriers among PS sensitive cases versus 75% of the resistant cases. These findings suggest that although the level of PS resistance is still valid for treatment of malaria in the study area of Lao PDR, post-treatment induction of gametocytemia among resistant cases may result an increase in transmission rate of PS resistant falciparum malaria. 相似文献
49.
Danjo K Sakamoto J Iwane S Tamura K Nakaji S Fukuda S Murakami H Shimoyama T Takahashi I Umeda T 《Digestive diseases and sciences》2008,53(3):712-718
We investigated the effects of cellulose supplementation on fecal consistency and fecal weight. About 26 women were classified into two groups-normal defecation and constipation groups. All subjects ate the following meals during the experiment: ordinary meals (first week), experimental meals (second week), and experimental meals mixed with 4 g (third week) and 8 g (fourth week) cellulose. The experimental meal contained 16.7 g fiber. Fecal weights, fecal water content, fecal consistency, and defecation frequency were measured during the experimental period. As a result, in the normal defecation group, the mean fecal weight was 222.9 g day(-1) in the first week, and thereafter decreased. Although 20/24 g of fiber intake in the third/fourth week increased the fecal weight to over 150 g, the fecal consistency was still lower than the optimal consistency of around 300 g cm(-2). However, these changes were not observed in the constipated group. 相似文献