全文获取类型
收费全文 | 2449篇 |
免费 | 121篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 22篇 |
妇产科学 | 25篇 |
基础医学 | 277篇 |
口腔科学 | 41篇 |
临床医学 | 203篇 |
内科学 | 637篇 |
皮肤病学 | 30篇 |
神经病学 | 196篇 |
特种医学 | 98篇 |
外科学 | 411篇 |
综合类 | 7篇 |
一般理论 | 1篇 |
预防医学 | 99篇 |
眼科学 | 31篇 |
药学 | 148篇 |
中国医学 | 2篇 |
肿瘤学 | 337篇 |
出版年
2023年 | 27篇 |
2022年 | 72篇 |
2021年 | 117篇 |
2020年 | 47篇 |
2019年 | 54篇 |
2018年 | 68篇 |
2017年 | 54篇 |
2016年 | 71篇 |
2015年 | 70篇 |
2014年 | 87篇 |
2013年 | 127篇 |
2012年 | 173篇 |
2011年 | 153篇 |
2010年 | 85篇 |
2009年 | 82篇 |
2008年 | 104篇 |
2007年 | 110篇 |
2006年 | 140篇 |
2005年 | 105篇 |
2004年 | 100篇 |
2003年 | 107篇 |
2002年 | 100篇 |
2001年 | 38篇 |
2000年 | 30篇 |
1999年 | 35篇 |
1998年 | 17篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 21篇 |
1991年 | 13篇 |
1990年 | 21篇 |
1989年 | 30篇 |
1988年 | 29篇 |
1987年 | 17篇 |
1986年 | 22篇 |
1985年 | 31篇 |
1984年 | 18篇 |
1982年 | 9篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1971年 | 9篇 |
1970年 | 7篇 |
1969年 | 7篇 |
1968年 | 14篇 |
1967年 | 8篇 |
排序方式: 共有2582条查询结果,搜索用时 328 毫秒
1.
2.
3.
I. Tsunoda Yuzo Iwasaki Hiroshi Terunuma Kazuya Sako Yoshiro Ohara 《Acta neuropathologica》1996,91(6):595-602
Theiler’s murine encephalomyelitis viruses (TMEV) are divided into two subgroups on the basis of their different biological
activities. The GDVII strain produces acute polioencephalomyelitis in mice, whereas the DA strain produces demyelination with
virus persistence in the spinal cord. A comparative study of GDVII and DA strains suggested that low host immune responses
are responsible for the development of acute GDVII infection and that the persistence of infected macrophages plays a crucial
role in the development of chronic white matter lesions in DA infection. All 78 mice infected with GDVII died or became moribund
by day 13, while none of 54 mice infected with DA died. In the acute stage, the distribution of viral antigens in the central
nervous system (CNS) tissue was similar in both GDVII and DA infections, although the virus titer was higher in GDVII infection.
In DA infection, a substantial number of T cells were recruited to the CNS on day 6 when they were virtually absent in GDVII
infection. The titer of neutralizing antibody was already high on day 6 in DA infection but was negligible in GDVII infection.
Development of chronic paralytic disease from day 35 of the DA infection was accompanied by focal accumulation of viral antigen-positive
macrophages in the spinal white matter. In addition, white matter lesions comparable to those in chronic DA infection were
induced in the spinal cord within 7 days after intracerebral injection of DA-infected murine macrophages.
Received: 26 June 1995 / Revised, accepted: 27 December 1995 相似文献
4.
Effects of dominant and nondominant eyes in binocular rivalry. 总被引:1,自引:0,他引:1
Tomoya Handa Kazuo Mukuno Hiroshi Uozato Takahiro Niida Nobuyuki Shoji Kimiya Shimizu 《Optometry and vision science》2004,81(5):377-383
PURPOSE: To investigate the relation between sighting and sensory eye dominance and attempt to quantitatively examine eye dominance using a balance technique based on binocular rivalry. METHODS: The durations of exclusive visibility of the dominant and nondominant eye target in binocular rivalry were measured in 14 subjects. The dominant eye was determined by using the hole-in-card test (sighting dominance). In study 1, contrast of the target in one eye was fixed at 100% and contrast of the target in the other eye was varied from 100% to 80% to 60% to 40% to 20%, when using rectangular gratings of 1, 2, and 4 cycles per degree (cpd) at 2 degrees, 4 degrees , and 8 degrees in size. In study 2, contrast of the target in the nondominant eye was fixed at 100% and contrast of the target in the dominant eye was varied from 100% to 80% to 60% to 40% to 20%, when using a rectangular grating of 2 cpd at 4 degrees in size. RESULTS: In study 1, the total duration of exclusive visibilities of the dominant eye target; that is, the target seen by the eye that had sighting dominance was longer compared with that of the nondominant eye target. When using rectangular gratings of 4 cpd, mean total duration of exclusive visibility of the dominant eye target was statistically longer than that of the nondominant eye target (p < 0.05). In study 2, reversals (in which duration of exclusive visibility of the nondominant eye becomes longer than the dominant eye when the contrast of the dominant eye target is decreased) were observed for all contrasts except for 100%. CONCLUSIONS: The dominant sighting eye identified by the hole-in-card test coincided with the dominant eye as determined by binocular rivalry. The contrast at which reversal occurs indicates the balance point of dominance and seems to be a useful quantitative indicator of eye dominance to clinical applications. 相似文献
5.
Protein kinase C (PKC) activity was measured in rat brain with 2 h of middle cerebral artery (MCA) and common carotid artery (CCA) occlusion, using dual autoradiography of [14C]iodoantipyrine (IAP) and [3H]phorbol-12,13-dibutyrate (PDBu). In the ischemic brain, it required more than 120 min of incubation to obtain a plateau in PDBu binding. In contrast, the binding of PDBu in non-ischemic brain reached a plateau with incubation for 60 min. This delay of PDBu binding in the ischemic brain suggests that the affinity of this ligand is reduced due to a change in structure of the cell membrane caused by ischemia. PDBu binding in the ischemic brain increased significantly compared to the non-ischemic brain. This finding provides further evidence that excessive activation of PKC in the ischemic brain may play an important role in ischemic neuronal damage. ©1997 Elsevier Science B.V. All rights reserved. 相似文献
6.
HA1077, a novel calcium antagonistic antivasospasm drug, increases both cerebral blood flow and glucose metabolism in conscious rats. 总被引:1,自引:0,他引:1
The effects of a novel calcium antagonistic antivasospasm drug, HA1077, on local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were studied in 33 anatomically discrete regions of the brain in conscious rats, using the quantitative autoradiographic [14C]iodoantipyrine and [14C]2-deoxyglucose techniques. HA1077 was infused i.v. over a 30-min period (1 or 3 mg/kg). HA1077 significantly increased LCBF in 9 of 33 sites in rats given 1 mg/kg, and in 14 of 33 sites in rats given 3 mg/kg compared to the control group given vehicle. Significant increases in LCGU were also noted in 16 of 33 sites in rats given 3 mg/kg. HA1077 increased both cerebral blood flow and glucose metabolism in conscious rats. 相似文献
7.
Treatment of erectile dysfunction (ED) in hypertensive subjects remains to be formally established. There is currently no standardized treatment for ED in hypertensive subjects. In this study, we tested our hypothesis that hypotensive drugs would improve impaired relaxation in the corpus cavernosum of spontaneously hypertensive rats (SHR). Ten-week-old SHR was treated with amlodipine, imidapril or hydralazine for 4 weeks. Although all three drugs achieved an equivalent decrease in systolic blood pressure (SBP), only amlodipine and imidapril induced an increase in relaxation in response to electrical field stimulation (EFS) of the corpus cavernosum. In the case of amlodipine, this effect was dose- and SBP-dependent. Nitric oxide (NO)-dependent relaxation was increased by amlodipine over a wide range of EFS frequencies, was increased by imidapril at low EFS frequencies, and was decreased by hydralazine. Carbon monoxide (CO)-dependent relaxation was only increased by hydralazine, and this increase occurred over a wide range of frequencies. The NOx and cGMP levels in the EFS-stimulated corpus cavernosum were increased by amlodipine. Amlodipine did not affect the thiobarbituric acid-reacting substance levels in the serum and the corpus cavernosum, but did decrease superoxide dismutase activity in the tissue. Imidapril and hydralazine inhibited the acetylcholine-induced relaxation in the corpus cavernosum. Sodium nitroprusside-induced relaxation in the tissue was increased by amlodipine. All three agents similarly inhibited the phenylephrine-induced contraction. These results suggest that impaired neurogenic relaxation in the corpus cavernosum of SHR is improved by amlodipine and imidapril through an increase in the synthesis and/or release of neuronal NO, but not CO, and presumably the inhibited detumescence of erection, which is induced by norepinephrine being released from sympathetic neuron. These findings indicate that amlodipine and imidapril may ameliorate the decreased relaxation of cavernous smooth muscle in the setting of hypertension. 相似文献
8.
S Tadera N Oka M Sako M Sugino G Hamami O Matsumoto S Kamidono 《Hinyokika kiyo. Acta urologica Japonica》1986,32(3):462-467
A case of a 19-year-old male with leiomyosarcoma of the prostate is reported. He visited our hospital with the chief complaint of urinary retention in December, 1983. Following overall examination, needle biopsy of the prostate gland was performed with the suspicion of sarcoma. Histology of the prostate revealed leiomyosarcoma. Two courses of combined chemotherapy were given, but the tumor continued to enlarge. The patient died in April, 1984, 5 months after the appearance of the first symptom. 相似文献
9.
10.
Takeshi Shinkawa Masaaki Yamagishi Keisuke Shuntoh Takako Miyazaki Takahiro Hisaoka Tomoya Inoue Hitoshi Yaku 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(11):469-471
Objective We have developed a surgical method for atrial septal defect repair through a limited right lateral thoracotomy in which the
incision line begins 2 cm caudal from the lower angle of the scapula and ends at the midaxial line, thereby improving patient
satisfaction with the cosmetic results of treatment.
Methods We performed a retrospective review of 28 patients who underwent isolated atrial septal defect repair through a limited right
lateral thoracotomy between January 2002 and August 2004. The mean age and mean body weight at the time of the operation were
85.8 months (range 9–236 months) and 23.0 kg (range 8.0–56.0 kg), respectively. All repaired defects were the ostium secundum
type.
Results There was no operative or late mortality and no late morbidity after a mean follow-up of 26 months (range 12–41 months). Echocardiography
showed no residual shunt in any of the patients. The mean length of the skin incision was 7.8 cm (range 5.0–11.0 cm), and
almost all the patients had satisfactory cosmetic results.
Conclusion The atrial septal defect repair through a limited right lateral thoracotomy in pediatric patients showed satisfactory surgical
results and excellent cosmetic results. 相似文献