全文获取类型
收费全文 | 5201篇 |
免费 | 256篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 77篇 |
妇产科学 | 58篇 |
基础医学 | 583篇 |
口腔科学 | 293篇 |
临床医学 | 365篇 |
内科学 | 1351篇 |
皮肤病学 | 80篇 |
神经病学 | 302篇 |
特种医学 | 216篇 |
外科学 | 822篇 |
综合类 | 23篇 |
预防医学 | 373篇 |
眼科学 | 48篇 |
药学 | 391篇 |
中国医学 | 39篇 |
肿瘤学 | 397篇 |
出版年
2022年 | 75篇 |
2021年 | 88篇 |
2020年 | 41篇 |
2019年 | 77篇 |
2018年 | 79篇 |
2017年 | 63篇 |
2016年 | 67篇 |
2015年 | 62篇 |
2014年 | 87篇 |
2013年 | 131篇 |
2012年 | 173篇 |
2011年 | 222篇 |
2010年 | 106篇 |
2009年 | 95篇 |
2008年 | 186篇 |
2007年 | 211篇 |
2006年 | 206篇 |
2005年 | 221篇 |
2004年 | 193篇 |
2003年 | 195篇 |
2002年 | 206篇 |
2001年 | 182篇 |
2000年 | 188篇 |
1999年 | 179篇 |
1998年 | 58篇 |
1997年 | 70篇 |
1995年 | 36篇 |
1994年 | 43篇 |
1993年 | 36篇 |
1992年 | 130篇 |
1991年 | 124篇 |
1990年 | 123篇 |
1989年 | 134篇 |
1988年 | 139篇 |
1987年 | 151篇 |
1986年 | 138篇 |
1985年 | 130篇 |
1984年 | 94篇 |
1983年 | 60篇 |
1982年 | 34篇 |
1981年 | 38篇 |
1979年 | 52篇 |
1977年 | 41篇 |
1975年 | 38篇 |
1973年 | 32篇 |
1971年 | 49篇 |
1970年 | 45篇 |
1969年 | 47篇 |
1967年 | 34篇 |
1966年 | 35篇 |
排序方式: 共有5482条查询结果,搜索用时 15 毫秒
11.
BACKGROUND: Based on epidemiological studies of prevalence, sensitization as well as pollen survey, it is presumed that airborne Japanese cedar pollen (JCP) and cypress (JCyP) have increased progressively for past 40 years. However, because of their large yearly variations, accurate objective and scientific study is required to confirm if it is true or not. METHODS: We analyzed the time trends of JCP and JCy separately in 11 districts throughout Japan where have records of continuous past survey from 1986 to 2005, by regression analysis using net pollen count and their 3 and 5 running means. RESULTS: When significant slope of regression line (regression coefficient) is assumed as p < 0.05 and R2 (coefficient of determination) >0.4, significant increase in airborne pollen was revealed in the use of 5 point running mean (6 districts of total 11 in JCP and 5 in JCyP) but not net count or 3 point running mean because of correction of statistic error due to large yearly variations. This study suggested that our method used for analysis of a recent increase in airborne JCP and JCyP was useful and scientific. 相似文献
12.
Various tannins and related compounds were compared for their ability to stimulate the iodination (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood monocytes. The stimulating activity of most of the monomeric and dimeric hydrolyzable tannins was generally higher than that of the trimeric and tetrameric compounds. Compounds that had dehydrohexahydroxydiphenoyl or chebuloyl groups had considerably less activity than those that had other functional groups (hexahydroxydiphenoyl, valoneoyl, dehydrodigalloyl, isodehydrodigalloyl, lactonized valoneoyl, hellinoyl, euphorbinoyl, dehydroeuphorbinoyl or woodfordinoyl group). The methylated derivative, nonacosa-O-methylcoriariin A, was essentially inactive, suggesting the requirement of a phenolic hydroxyl group. Three condensed tannins ((-)-epicatechin 3-O-gallate (ECG)-dimer, ECG-trimer and ECG-tetramer) significantly stimulated both monocyte iodination and their interleukin-1-like factor production. The results suggest the dependence of stimulation of monocyte iodination by tannins and related polyphenols on molecular weight. 相似文献
13.
Percutaneous radiofrequency neurotomy of lumbar medial branch (facet rhizotomy)--a report of 6 cases
H Yamagami K Hashizume K Nakahashi T Okuda 《Masui. The Japanese journal of anesthesiology》1990,39(4):491-495
We performed radiofrequency neurotomy of lumbar medial branch as a treatment of facet syndrome. Our six cases had no indication for surgical therapy, such as neuralgia, spinal canal stenosis without neurological deficit except for pain and deformed spines. Facet joint injection with regional anesthetics and steroids could not prevent their recurrent back pain. By facet rhizotomy, they could obtain relief of back pain for several months to a year. We conclude that facet rhizotomy is a more effective method for facet syndrome when a proper indication is present. 相似文献
14.
H Koyama K Honda K Okuda K Tsuchiya S Tanaka H Kawasaki 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(9):1111-1118
Community-acquired pneumonia is one of the major respiratory diseases causing hospital admission in previously healthy patients. Prompt and appropriate antibiotic selection is essential for recovery. The authors tried to determine the distribution of the etiologic agents of community-acquired pneumonias and to analyze predictive factors. Out of 188 cases of community-acquired pneumonia presenting to our hospital, etiologic agents were determined in 106 cases (56%). Twenty-nine cases were due to Streptococcus pneumoniae, 27 cases due to Mycoplasma, 17 cases due to Haemophilus influenzae and 21 cases due to Mycobacterium tuberculosis. M. tuberculosis was the cause in 11% of all cases and the importance of pulmonary tuberculosis must be emphasized as a community-acquired pneumonia. Out of 58 cases under 50 years old, Mycoplasma pneumoniae was the etiologic agent in 23 cases (40%) and S. pneumoniae in 7 cases (12%). Out of 62 cases not less than 70 years old. M. tuberculosis was the most common etiologic agent (15 cases, 24%). S. pneumoniae followed, being causative in 13 cases (21%). M. tuberculosis was the cause in 10 cases out of 31 cases who did not complain of fever at presentation. In 86 cases who did not show leukocytosis on admission, 21 cases were due to Mycoplasma (24%) and 15 cases were due to M. tuberculosis (17%). In particular 17 cases were due to Mycoplasma among 28 cases under 50 years old without leukocytosis (61%), and 11 cases were due to M. tuberculosis in the 27 cases no less than 70 years old without leukocytosis (41%).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
15.
Y Nakada M Simajiri M Shimabukuro K Oshiro F Nagamine K Murakami G Mimura Y Koyama A Osawa 《Nihon Ronen Igakkai zasshi. Japanese journal of geriatrics》1991,28(6):811-816
An elderly case of idiopathic retroperitoneal fibrosis (IRPF) with bilateral ureteral obstruction was reported. A 74-year-old man was admitted with complaints of general fatigue and loss of appetite. An elastic hard mass with a smooth surface was palpated in the left upper quadrant of the abdomen. Abnormal ESR and CRP were noticed. Abdominal ultrasonography showed both a homoechoic mass which surrounded the aorta in the retroperitoneal space and bilateral hydronephrosis. Computed tomography revealed a retroperitoneal mass involving bilateral ureters. Magnetic resonance imaging demonstrated a mass with a sharp image and signal intensity. Furthermore the morphological relationship between the mass and the ureters and major vessels clearly indicated the characteristics of benign retroperitoneal fibrosis. Based upon the above findings, a diagnosis of IRPF was made. After confirming the histological diagnosis by biopsy, treatment consisting of bilateral ureterolysis, intra-abdominal transposition of ureters and oral administration of prednisolone was performed, resulting in a normalization of laboratory findings. Analysis of 86 previously cases of IRPF reported up to 1990 in Japan, revealed the peak age to be in the 7th decade with predominance in males (males: females = 57:29). 相似文献
16.
A Sakai T Hori T Okuda T Matsubara K Saitoh M Yajima S Nishio 《Japanese journal of pharmacology》1989,51(3):450-454
TRK-100 (0.03, 0.1 and 0.3 mg/kg, p.o.), a chemically stable analogue of prostacyclin, dose-dependently prevented blood coagulation and glomerular fibrin deposition which were enhanced by 4 hr infusion of endotoxin (100 mg/kg) in rats. In addition, TRK-100 suppressed the generation of endotoxin-induced tissue thromboplastin like activity in cultured human endothelial cells. 相似文献
17.
18.
The effect of intravenous infusion of 10% glycerol on polymorphic delta waves of EEG was investigated in 13 patients (15 studies) with brain tumors in cerebral hemisphere. The delta waves were analyzed by two-dimensional EEG topography and power spectrum of delta waves (P(delta)) over the tumor, adjacent, and distant regions in the same hemisphere to the tumor, and ipsi- and contralateral hemispheres to the tumor. The data focus of EEG topography was well corresponded to the tumor and surrounding brain edema which visualized by x-ray CT-scan. In the patient with brain tumors with marked brain edema (group A, 11 studies), EEG topography showed marked reduction of delta focus within 20 minutes from the end of intravenous infusion of glycerol, and returned to preinfusion distribution within 60 minutes. In patients with absent to minimum brain edema (group B, 4 studies), delta focus showed the tendency to enlarge and returned to preinfusion state at 60 minutes after the end of glycerol infusion. In patients of group A, P(delta) of ipsilateral hemisphere to tumor decreased at the end of glycerol infusion, and showing maximal reduction ratio (30%, p less than 0.01) at 20 minutes, re-increased there-after. In group B, P(delta) of ipsilateral hemisphere showed no definite changes after the glycerol infusion. P(delta) of contralateral hemispheres in patients of both group A and B, showed similar reduction ratio and time course to those of ipsilateral hemisphere of group A.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
19.
A 65-year-old right-handed woman was admitted due to gait disturbance. She had suffered from progressive motor clumsiness in the left-sided limbs for four years. On admission, she was mildly demented, but not aphasic. Neurological examination disclosed constructional disability, limb-kinetic apraxia on the left side, and parkinsonism. Brain CT and MRI showed no responsible lesion. Three-dimensional surface display with 123I-IMP demonstrated decreased cerebral blood flow mainly in the right angular gyrus, and mildly in the right central region. She was clinically diagnosed as having corticobasal degeneration. Hypoperfusion in the angular gyrus and central region may account for constructional disability and limb-kinetic apraxia, respectively. Three-dimensional surface display with 123I-IMP appears to be useful for detecting the cortical region. 相似文献
20.
Alterations in thyrotropin-releasing hormone (TRH) content in the brain during hemorrhagic shock were examined in conscious rats, and the results were interpreted in relation to the reversibility of the shock. Two sets of experiments were run. The first one was to establish reversible and irreversible shock models. Hemorrhagic shock was induced by the initial withdrawal of 4 ml of blood followed by 1 ml bleeds at 5, 15, 30, and 60 min to maintain the blood pressure at 40-70 mmHg for 60 min. Blood withdrawn during and 60 min after the end of the shock was used to measure plasma lactate levels and blood gases. Shock was considered to be reversible if the animal survived for 24 hr after the hemorrhage. The plasma lactate levels as well as Base Excess and PaCO2 during and 60 min after the end of the hemorrhage of the surviving rats were significantly different from those of the animals which died within 24 hr. In particular, the plasma lactate levels at 60 min after the end of the hemorrhagic period were good indicators of the mortality of animals; it was predicted that rats whose plasma lactate levels are higher than 3.8 mEq/L would die within 24 hr (0.69% probability of misdiscrimination). The second experiment was to measure brain TRH content during and after hemorrhage produced using the same bleeding procedure as the first. During hemorrhage, brain TRH contents in the medulla oblongata and midbrain were found to be significantly increased compared with the control values. At 60 min after the end of hemorrhage, significantly higher TRH content values were obtained in the medulla oblongata, midbrain, cerebral cortex, striatum, and cerebellum in the rats whose plasma lactate levels were lower than 3.8 mEq/L compared with those of animals having plasma lactate values higher than 3.8 mEq/L. From the results of the two sets of experiments, it is concluded that the surviving animals have more TRH in the brain regions mentioned above than the non-surviving animals after hemorrhagic shock, and it is suggested that brain TRH plays a beneficial role in the course of recovery from hemorrhagic shock. 相似文献