全文获取类型
收费全文 | 14276篇 |
免费 | 683篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 107篇 |
儿科学 | 221篇 |
妇产科学 | 253篇 |
基础医学 | 1634篇 |
口腔科学 | 353篇 |
临床医学 | 899篇 |
内科学 | 4068篇 |
皮肤病学 | 247篇 |
神经病学 | 1118篇 |
特种医学 | 561篇 |
外国民族医学 | 2篇 |
外科学 | 2423篇 |
综合类 | 70篇 |
预防医学 | 442篇 |
眼科学 | 168篇 |
药学 | 855篇 |
中国医学 | 14篇 |
肿瘤学 | 1598篇 |
出版年
2023年 | 86篇 |
2022年 | 194篇 |
2021年 | 324篇 |
2020年 | 167篇 |
2019年 | 209篇 |
2018年 | 276篇 |
2017年 | 204篇 |
2016年 | 270篇 |
2015年 | 301篇 |
2014年 | 331篇 |
2013年 | 449篇 |
2012年 | 691篇 |
2011年 | 753篇 |
2010年 | 426篇 |
2009年 | 343篇 |
2008年 | 669篇 |
2007年 | 655篇 |
2006年 | 670篇 |
2005年 | 741篇 |
2004年 | 703篇 |
2003年 | 665篇 |
2002年 | 626篇 |
2001年 | 425篇 |
2000年 | 407篇 |
1999年 | 432篇 |
1998年 | 196篇 |
1997年 | 177篇 |
1996年 | 142篇 |
1995年 | 151篇 |
1994年 | 99篇 |
1993年 | 105篇 |
1992年 | 338篇 |
1991年 | 289篇 |
1990年 | 275篇 |
1989年 | 328篇 |
1988年 | 255篇 |
1987年 | 233篇 |
1986年 | 230篇 |
1985年 | 183篇 |
1984年 | 134篇 |
1983年 | 95篇 |
1980年 | 43篇 |
1979年 | 79篇 |
1978年 | 52篇 |
1977年 | 45篇 |
1975年 | 47篇 |
1974年 | 63篇 |
1973年 | 63篇 |
1972年 | 50篇 |
1969年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Four cases with hysterical amblyopia in youngsters under 15-year-old showed the poor reproducibility of visual field, that is, when the same target was moved from the periphery toward the fixation ten times along the same meridian during the same examination, the position of the plotted points were rather variable. The range of variation was measured from the innermost point to the outermost one, after the two first points were omitted because points first detected were usually far from the others. The variation of cases measured by this method was compared with that of normal persons. Results were as follows; 1. in normal person, the mean value of its range was 5.5° in first decade and 4.2° in second to seventh decade; 2. patients with psychogenic visual disturbances showed a variability of 14.2°, and this was significantly different from normal (p < 0.01). These results suggest that this convenient method was helpful for diagnosis of hysteria. It should also be remembered that when we evaluate the visual field, changes under 4° are probably not significant. 相似文献
52.
53.
In Vitro Evaluation of Platelet/Biomaterial Interactions in an Epifluorescent Video Microscopy Combined with a Parallel Plate Flow Cell 总被引:1,自引:0,他引:1
Nobuchika Kawagoishi Chisato Nojiri Kazuhisa Senshu Takayuki Kido Hirofumi Nagai Toshiyuki Kanamori Kiyotaka Sakai Hitoshi Koyanagi† Tetsuzo Akutsu 《Artificial organs》1994,18(8):588-595
Abstract: Suitable evaluation systems are critical for ranking various biomaterials in order to develop a method to design and synthesize nonthrombogenic biomaterials. We have recently developed an in vitro test system to evaluate platelet/biomaterial interactions in whole blood. The system consists of a parallel plate flow cell and epifluorescent video microscopy (EVM). A glass coverslip coated with a polymer was incorporated into the flow cell, and blood was perfused using a syringe pump via a polymer–coated PVC tubing connected to the flow cell. Whole human blood was anticoagulated with heparin (2 U/ml), and the platelets were labeled with the fluorescent dye mepacrine (5 μM). This system permitted real–time and dynamic observations of platelet/biomaterial interactions in whole blood under a defined flow condition. In order to evaluate the feasibility of this system, two different segmented polyether–polyurethanes (SPEUs), PU–PTMG(650) and PU–PTMG(2000), were chosen as test polymers. Surface characteristics verified with electron spectroscopy for chemical analysis (ESCA) and contact angle measurements showed similar results in both SPEUs. Blood was perfused at a wall shear rate of 200 s–1 for 20 min. Excitation light was applied for 2 s at 1 min intervals. The real–time image was then analyzed at each time point for the percentage of surface area of platelet coverage. Plasma β–thromboglobulin (β–TG) levels were also measured before and after each run. PU–PTMG(650) showed a significantly higher number of adhered platelets than PU–PTMG(2000) at each time point. β–TG levels of PU–PTMG(650) were also higher than those of PU–PTMG(2000), which is comparable to the results of EVM. Thus, this EVM system has been proven to be an excellent and highly sensitive in vitro analytical method for evaluating platelet/biomaterial interactions. 相似文献
54.
Naoto Miyanaga Hideyuki Akaza Shuji Kameyama Takahiko Hachiya Seiichiro Ozono Masao Kuroda Hirofumi Koga Kenkichi Koiso 《International journal of urology》1997,4(6):557-560
Background :
The BTA test is a latex agglutination assay for the qualitative detection in the urine of analytes that are associated with bladder tumor. We compared the results of the BTA test with those of voided urine cytology (VUC) in patients with bladder cancer.
Methods :
A multicenter trial was performed at 6 institutions. A total of 132 patients with histologically diagnosed bladder cancer were enrolled. Urine samples were split for BTA and VUC testing.
Results :
The sensitivities of the BTA test and VUC were 57.6% and 37.9%, respectively; this difference was significant ( P < 0.001). The BTA test had much higher sensitivity for small, solitary, superficial tumors than did VUC.
Conclusion :
The BTA test is simple to perform, gives rapid results, and is far more sensitive than VUC for detection of bladder cancer. The BTA test has the potential to become an additional tool for detecting bladder cancer. 相似文献
The BTA test is a latex agglutination assay for the qualitative detection in the urine of analytes that are associated with bladder tumor. We compared the results of the BTA test with those of voided urine cytology (VUC) in patients with bladder cancer.
Methods :
A multicenter trial was performed at 6 institutions. A total of 132 patients with histologically diagnosed bladder cancer were enrolled. Urine samples were split for BTA and VUC testing.
Results :
The sensitivities of the BTA test and VUC were 57.6% and 37.9%, respectively; this difference was significant ( P < 0.001). The BTA test had much higher sensitivity for small, solitary, superficial tumors than did VUC.
Conclusion :
The BTA test is simple to perform, gives rapid results, and is far more sensitive than VUC for detection of bladder cancer. The BTA test has the potential to become an additional tool for detecting bladder cancer. 相似文献
55.
Influence of acetylcholine on neuronal activity of monkey amygdala during bar press feeding behavior
L zl L n rd Yutaka Oomura Yasuhiko Nakano Shuji Aou Hitoo Nishino 《Brain research》1989,500(1-2):359-368
Single neuron activity in the monkey amygdala was investigated during cue signalled conditioned bar press feeding behavior and the effects of electrophoretically applied acetylcholine (ACh) and atropine were analyzed. ACh increased the firing rate of one third of the neurons tested; these excitatory responses were inhibited by the muscarinic receptor antagonist atropine. No characteristic location of ACh-sensitive neurons was found, cells were diffusely distributed throughout the amygdala. Activity of ACh-sensitive neurons did not correlate with any particular event during the bar press feeding task. However, continuous application of ACh at low current intensity during the task significantly enhanced the task-related excitatory firing patterns, or markedly attenuated the inhibitory responses. Continuous application of atropine elicited or enhanced inhibitory response patterns. These results suggest that the cholinergic system of the monkey amygdala facilitates neuronal excitation but attenuates inhibition related to various phases of feeding behavior, such as to cue recognition, food aquisition and rewarding process. 相似文献
56.
Tomohiro Kondo Kazuhiro Sentani Naohide Oue Kazuhiro Yoshida Hirofumi Nakayama Wataru Yasui 《Pathobiology》2004,71(1):19-25
OBJECTIVES: RHOC, a member of the RAS-related small GTPase protein family, regulates cytoskeletal structures and has the potential to transform cultured cells. It has recently been reported that RHOC contributes to the metastatic phenotype of melanoma cells. The purpose of this study was to clarify its biological relevance to gastric carcinogenesis and metastasis. METHODS: We examined the expression of RHOC by quantitative RT-PCR in 51 cases of gastric carcinoma tissues from prior surgical cases (intestinal type: 24 cases, diffuse type: 27 cases) and in 8 gastric carcinoma cell lines. RESULTS: RHOC expression levels in primary tumors were significantly higher in cases with metastasis than in those without metastasis (p = 0.0202; Mann-Whitney U test). RHOC expression levels in primary tumor and their metastatic tumors were significantly higher than their corresponding nonneoplastic mucosa (p = 0.0357, and 0.0173, respectively; Wilcoxon signed rank test). RHOC mRNA expression was confirmed in the gastric carcinoma cell lines. CONCLUSION: Our findings suggest that elevated expression of the RHOC gene may be involved in the metastasis of gastric carcinomas and may be a good genetic marker for the prediction of a metastatic potential. 相似文献
57.
Hirofumi Fukushima Emiko Katou Kouji Nagayama Akira Shirachi Michio Sata 《Nihon Shokakibyo Gakkai zasshi》2006,103(6):661-666
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
58.
N Yamada M Nakamura K Ishikura M Ota T Yazu N Hiraoka H Tanaka M Ito H Fujioka N Isaka T Nakano 《International angiology》2003,22(1):50-54
AIM: In Japan, acute pulmonary thromboembolism (APTE) is still rare, but the number of patients with APTE has been steadily increasing. It is important for early diagnosis and early management of APTE to recognize epidemiological characteristics of this condition. METHODS: We investigated the epidemiological characteristics of 252 patients with APTE who were admitted to our institutions between 1975 and 2001. APTE was more prevalent in women that in men. It was observed the most in the age group between 50s to 70s, especially in women. Many patients had prolonged immobilization, recent major operation, obesity, or cancer, as risk factors for venous thromboembolism. One hundred and thirty-eight patients developed APTE in hospital; 60 patients were in Department of Internal Medicine, 28 in General Surgery, 15 in Orthopedics, 15 in Obstetrics and Gynecology, and 20 in other services. RESULTS: Among 58 patients with malignancy, 43% had cancers in digestive organs, 21% in gynecological, and 17% in urological. Among 61 patients who were examined for the presence of thrombophilia, 13 patients had inherited thrombophilia (8 protein C deficiency, 4 protein S deficiency, and 1 antithrombin III deficiency) 11 had antiphospholipid antibodies which indicated thrombophilia. Five out of the above 61 patients (8%) had no obvious risk factors including thrombophilia. CONCLUSION: The findings in our patients were almost the same as those in Western patients, except for some points. These results might be useful to establish a preventive approach for APTE in Japan. 相似文献
59.
60.