全文获取类型
收费全文 | 8293篇 |
免费 | 390篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 85篇 |
儿科学 | 143篇 |
妇产科学 | 87篇 |
基础医学 | 1090篇 |
口腔科学 | 131篇 |
临床医学 | 526篇 |
内科学 | 2209篇 |
皮肤病学 | 84篇 |
神经病学 | 717篇 |
特种医学 | 270篇 |
外科学 | 1353篇 |
综合类 | 32篇 |
预防医学 | 245篇 |
眼科学 | 116篇 |
药学 | 735篇 |
中国医学 | 33篇 |
肿瘤学 | 889篇 |
出版年
2023年 | 22篇 |
2022年 | 61篇 |
2021年 | 102篇 |
2020年 | 49篇 |
2019年 | 88篇 |
2018年 | 103篇 |
2017年 | 102篇 |
2016年 | 119篇 |
2015年 | 138篇 |
2014年 | 145篇 |
2013年 | 222篇 |
2012年 | 324篇 |
2011年 | 354篇 |
2010年 | 239篇 |
2009年 | 203篇 |
2008年 | 319篇 |
2007年 | 394篇 |
2006年 | 392篇 |
2005年 | 401篇 |
2004年 | 388篇 |
2003年 | 412篇 |
2002年 | 432篇 |
2001年 | 325篇 |
2000年 | 347篇 |
1999年 | 346篇 |
1998年 | 112篇 |
1997年 | 94篇 |
1996年 | 81篇 |
1995年 | 87篇 |
1994年 | 94篇 |
1993年 | 99篇 |
1992年 | 238篇 |
1991年 | 251篇 |
1990年 | 218篇 |
1989年 | 202篇 |
1988年 | 205篇 |
1987年 | 172篇 |
1986年 | 185篇 |
1985年 | 144篇 |
1984年 | 97篇 |
1983年 | 76篇 |
1982年 | 46篇 |
1981年 | 30篇 |
1980年 | 28篇 |
1979年 | 79篇 |
1978年 | 37篇 |
1977年 | 26篇 |
1976年 | 22篇 |
1975年 | 12篇 |
1969年 | 10篇 |
排序方式: 共有8745条查询结果,搜索用时 12 毫秒
1.
Yoshiro Matsui Mizuho Ohta Kohsuke Ohno Masao Nagumo 《Journal of oral and maxillofacial surgery》2006,64(10):1540-1545
PURPOSE: This study evaluated the bone volume, height, and width that can be obtained in alveolar ridge augmentation using titanium mesh and autogenous bone particles in patients with cleft lip/palate. PATIENTS AND METHODS: Subjects were 15 patients with cleft lip/palate requiring tertiary bone graft for implant therapy. Computed tomography (CT) scans were taken before removing the mesh, from 1 to 21 months after bone grafting. Forty-three reconstructed images corresponding to the positions for implant placement were selected for this study. The percent defect filled with bone (%BONE), defined as the percentage of newly formed bone in the space created by the mesh, was measured for image analyses. In linear analyses, 4 parameters were used: increased bone height (IBH), percent increased bone height (%IBH), increased bone width (IBW), and percent increased bone width (%IBW). Factors influencing the quantitative data and the clinical courses of placed implants were also explored. RESULTS: The average %BONE was 91.1%. IBH averaged 4.4 mm, whereas %IBH averaged 88.5%. IBW averaged 4.6 mm, whereas %IBW averaged 86.4%. Little correlation was present between the quantitative data and patient age, or time interval. A significant correlation was identified between the data for span of the grafted area and %BONE (correlation coefficient value = -0.36). However, the diminishing rate was very low. No implants were lost postoperatively. CONCLUSIONS: Alveolar ridge augmentation with titanium mesh and autogenous bone particles from the anterior iliac crest has very high predictability as a preimplant procedure in patients with cleft lip/palate. 相似文献
2.
Previous studies have suggested that inhaled furosemide may have a protective effect against a wide variety of bronchoconstrictor agents, but a therapeutic effect has not been established in acute exacerbation of asthma. The purpose of this study was to investigate whether inhaled furosemide would exhibit any therapeutic benefit in acute asthma. We conducted a double-blind, placebo-controlled, randomized study in 40 patients with acute mild or moderate exacerbation of asthma. All patients received intravenous (IV) aminophylline 250 mg for 90 min and IV hydrocortisone 100 mg at entry. After randomization, 3 patients were excluded from the final analysis. At 30 min after starting IV aminophylline, 20 patients were given inhaled furosemide 20 mg and 17 patients received normal saline as placebo-control. Both inhalations were given by a jet nebulizer. The baseline forced expiratory volume at 1 sec (FEV1), peak expiratory flow rate (PEFR), and serum concentration of theophylline did not differ between the two groups. An increase in FEV1 in the furosemide group by 28.2 ± 5.9% (mean ± SE) was noted at 60 min, and this was significantly higher than in the control group. PEFR at 60 min was also significantly higher in the furosemide group than in control group. We conclude that inhaled furosemide has a bronchodilator effect on mild to moderate exacerbation of asthma when it is used with IV theophylline. Inhaled furosemide may benefit certain acute asthma patients, especially those suffering complications from the adverse effects of β2-agonists. 相似文献
3.
M Ohta H Casanova K Mizuno H Kaseki K Niwa H Ishiko 《Nippon Sanka Fujinka Gakkai zasshi》1991,43(5):479-484
Contagion with certain types of HPV was supposed to have a causal relationship with cervical neoplasia of the uterus. The rate of prevalence of HPV was investigated in pre-cancer and cancer patients with uterine cervical smear using virapap or viratype. According to the cytologic classification, among those whose cytology was diagnosed as class I or II, were found a few positive HPV, however, in cases in classes cytology IIIa, III and IIIb, the positive rate turned out to be 22.5, 41 and 72.4%, respectively. About 65% of patients whose post-operative diagnosis was cervical carcinoma, had been found positive in the pre-operative HPV.DNA check up. The statistical profiles of virally infected subjects were regarded as slightly younger females with early onset of menarche. A higher positive rate was found in such groups such as unmarried single and divorced single women, career employees with special skills, housewives and dwellers in residential and commercial sections. The follow up study of HPV infection was checked with subjects with dysplasia, and no case was recognized in which initially HPV negative dysplasia turned to positive during the observation period. But, in about 50% of those checked, initially HPV positive dysplasia turned to negative, during the follow up period. In the cases with long term (more than 8 years) dysplasia which was followed up, only one out of 10 was found to be HPV positive, while in middle term (more than 2 years but less than 8 years) followed up dysplasia, the positive rate was calculated as 47.8%. 相似文献
4.
T Fujita H Mori Y Osaki M Minowa S Ishihara N Masuda Y Hanzawa C Mori T Nanba H Ohta 《[Nihon kōshū eisei zasshi] Japanese journal of public health》1992,39(9):687-695
A case-control study was conducted to examine factors relating to discontinuation of domiciliary care for the bedridden elderly in Shinagawa-ku, Tokyo. Cases were bedridden residents aged 65 years and over who had abandoned home care and applied for admission to live in a special nursing home for the aged between April and September in 1990 after being recipients of welfare allowances for disabled elderly. Controls were bedridden residents who continued to be given home care and matched to cases by sex, age and beginning month of the receiving of allowances. Among 50 cases and 94 controls interviewed, we obtained responses from 31 cases (62%) and 60 controls (64%). The main results were as follows: 1. During the home-care period, ADL (activities of daily living) of cases, especially walking ability, deteriorated more severely than in controls. Night delirium also appeared more frequently in cases. 2. The primary caregivers of cases were older than those of controls. Remarkable differences between cases and controls were observed in the family structure, the number of family members and the number of sub-caregivers. Cases tended to live alone or live with a spouse only, and with smaller number of family members and caregivers. 3. Case lived more frequently in houses with small numbers of rooms and without rooms of their own. 4. As regards utilization of domiciliary care services, cases used dispatch of home helpers more frequently and used day services less frequently. 相似文献
5.
Epidural spinal cord stimulation was carried out in 4 patients with denervation caused by spinal cord lesion, and we reviewed previously reported cases. Initial result showed at 1 week in 100% of our cases, but about 1/3 of the cases, even those with the same denervation caused by spinal cord lesion, had no pain relief at this stage in previously reported cases. In our cases, excellent pain relief was gained temporarily, even though the painful area and the spinal cord lesion were separated somatotopically in 2 cases (case 3, 4). Temporary success bore no relationship to quality and duration of pain. In all cases except case 1, a rapidly decreasing effectiveness was noted, and finally no pain relief was gained at all after 4, 3 and 5 months, respectively. In case 1 there was persistent pain relief estimated at 70-80% after 19 months, only when the spinal cord was stimulated. Epidural stimulation also produced sensations in the painful area. Spinal cord stimulation would suppress at least the dorsal horn neurons which were destroyed by various kinds of diseases. A decline in effectiveness with time would occur due to essential causes of the deafferentation pain, such as anatomical and regeneration factors. 相似文献
6.
Effect of the rate of speech flow on speech intelligibility in normal and hearing-impaired subjects]
The relationship between the rate of speech flow and speech intelligibility was investigated in normal and hearing-impaired subjects. It is usually observed that a slowly and clearly delivered speech is easier for hearing-impaired patients to understand. The purpose of paper is to analyze this phenomenon clinically and to present useful data for developing new hearing aids. Four or 5 syllabic words lists were prepared for this experiment and speech stimuli were chosen from these lists. The subjects consisted of 15 normal subjects and 79 hearing-impaired patients (57 with inner ear hearing loss and 22 with retrocochlear hearing loss). Hearing tests were performed using a tape recorder with various speech control systems in a soundproof room. Speech samples were presented at three speaking rates, that is, a conversational speech rate, a rate one and a half times as fast as the conversational speech rate and a rate twice as fast as that rate. The results obtained in the normal subjects confirmed that the faster the speaking rate was, the more the word intelligibility was reduced. According to the results in the hearing-impaired subjects, both the correlation coefficient and regression parameter between the word intelligibility in this experiment and speech discrimination scores measured by 57S-monosyllabic lists were low at the conversational speaking rate, but the higher the speaking rate was, the closer the relation between the both factors was. It was estimated by analyzing the data of inner ear hearing loss and retrocochler hearing loss separately that the subjects with retrocochler hearing loss had more difficulty in speech-mediated communication than the subjects with inner ear hearing loss. 相似文献
7.
A focal cerebral ischemic model was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in normotensive (NTR) and spontaneously hypertensive rats (SHR). Main cerebral artery could be successfully occluded in approximately 90%. The most frequent embolized site was the distal part of the internal cerebral artery (ICb) and less frequently the horizontal segment of the anterior cerebral artery (Al). Mortality rate of NTR with ICb occlusion (NTR-ICb) was 43% at 72 hours after embolization and that of SHR with ICb occlusion (SHR-ICb) was 67% at 24 hours after embolization. NTR-ICb showed neurological signs (i.e. circling movement, hemiparesis, poor response to pain stimuli) and histologically, showed infarction in the deep cerebral structures (i.e. thalamus, hypothalamus, hippocampus, and internal capsule) accompanied with mild disruption of blood-brain barrier (BBB). SHR-ICb showed more serious neurological signs and more severe cerebral infarction in the deep cerebral structures with severe disruption of BBB. In SHR-ICb, ischemic cerebral edema was more prominent which may deteriorate symptoms and pathological findings compared to NTR-ICb. This embolization model is proposed to be useful for studying the pathophysiology of focal cerebral ischemia, especially, early ischemic edema. 相似文献
8.
H Ohta F I Shane K Endo K Torizuka K Horiuchi A Yokoyama M Ishii 《Clinical nuclear medicine》1986,11(12):842-844
The effectiveness of Tc-99m bleomycin (BLM) and Tc(V)-99m DMSA are compared with that of Ga-67 citrate, which is currently the most widely used agent. In four patients with lipomatous tumors, the clinical significance of tumor imaging with each of these three agents is discussed and compared. Results indicate that both Tc-99m BLM and Tc(V)-99m DMSA are superior in detecting the extension or localization of liposarcomas. 相似文献
9.
10.
We developed a constant-flow perfusion system to measure vascular responses to vasoactive agents applied intraluminally or extraluminally. The intraluminal and extraluminal sides of a cylindrical section of rabbit basilar artery were isolated completely. By loading with 0.75 g of tension, the resting condition of each preparation was made constant. The intraluminal side was perfused at a constant flow of 8 ml/min and under an intraluminal pressure of 8 mm Hg. When 30 mM KCl was administered intraluminally the preparation showed marked contraction, whereas only slight contraction was observed with extraluminal administration. When 2 x 10(-7) M 5-hydroxytryptamine was administered, no significant differences in contraction could be detected between the intraluminal and extraluminal routes. Application of 10(-6) to 10(-4) M acetylcholine after precontraction with 30 mM KCl resulted in much stronger dilatation upon intraluminal application. Thus, it was demonstrated that under certain conditions significant differences exist in the responses of rabbit basilar arteries to vasoactive agents applied intraluminally or extraluminally. This system can detect the effects of vasoactive agents administered intraluminally and extraluminally at a high level of sensitivity and shows good reproducibility as a means of analyzing vascular functions and characteristics. 相似文献