全文获取类型
收费全文 | 14984篇 |
免费 | 968篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 200篇 |
儿科学 | 340篇 |
妇产科学 | 165篇 |
基础医学 | 1843篇 |
口腔科学 | 230篇 |
临床医学 | 1191篇 |
内科学 | 3906篇 |
皮肤病学 | 300篇 |
神经病学 | 1035篇 |
特种医学 | 614篇 |
外科学 | 2126篇 |
综合类 | 211篇 |
一般理论 | 21篇 |
预防医学 | 1077篇 |
眼科学 | 350篇 |
药学 | 905篇 |
中国医学 | 60篇 |
肿瘤学 | 1530篇 |
出版年
2024年 | 14篇 |
2023年 | 96篇 |
2022年 | 198篇 |
2021年 | 341篇 |
2020年 | 236篇 |
2019年 | 330篇 |
2018年 | 375篇 |
2017年 | 354篇 |
2016年 | 395篇 |
2015年 | 437篇 |
2014年 | 551篇 |
2013年 | 684篇 |
2012年 | 1118篇 |
2011年 | 1069篇 |
2010年 | 666篇 |
2009年 | 525篇 |
2008年 | 998篇 |
2007年 | 1103篇 |
2006年 | 978篇 |
2005年 | 1029篇 |
2004年 | 885篇 |
2003年 | 958篇 |
2002年 | 900篇 |
2001年 | 136篇 |
2000年 | 114篇 |
1999年 | 135篇 |
1998年 | 169篇 |
1997年 | 178篇 |
1996年 | 140篇 |
1995年 | 132篇 |
1994年 | 91篇 |
1993年 | 77篇 |
1992年 | 68篇 |
1991年 | 52篇 |
1990年 | 50篇 |
1989年 | 40篇 |
1988年 | 37篇 |
1987年 | 30篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 27篇 |
1983年 | 31篇 |
1982年 | 28篇 |
1981年 | 24篇 |
1980年 | 29篇 |
1978年 | 23篇 |
1977年 | 28篇 |
1976年 | 18篇 |
1973年 | 15篇 |
1966年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Effect of pravastatin on coronary plaque volume 总被引:2,自引:0,他引:2
Ishikawa K Tani S Watanabe I Matsumoto M Furukawa K Nomoto K Nomoto K Kushiro T Nagao K Kanmatsuse K 《The American journal of cardiology》2003,92(8):975-977
A volumetric analysis by 3-dimensional intravascular ultrasound revealed that lipid-lowering therapy with pravastatin significantly reduced coronary plaque volume. The changes in plaque volume were inversely correlated with the changes in plasma levels of high-density lipoprotein cholesterol but not with changes in levels of total cholesterol or low-density lipoprotein cholesterol. 相似文献
992.
993.
Koike N Hatori T Imaizumi T Harada N Fukuda A Takasaki K Iwamoto Y 《Journal of Hepato-Biliary-Pancreatic Surgery》2003,10(1):101-105
Glucagonoma of the pancreas is a rare tumor with distinct clinical manifestations, such as necrolytic migratory erythema,
weight loss, anemia, diabetes mellitus, and hypoamino-acidemia. We report the case of a 68-year-old Japanese man who underwent
curative resection for malignant glucagonoma of the pancreas diagnosed through anemia and diabetes mellitus. The patient had
had diabetes mellitus for 20 years. Anemia was diagnosed in 1998. On admission, the hemoglobin level was 8.3 g/dl, but the
levels of serum iron, vitamin B12, and erythropoietin and, the number of reticulocytes were within normal limits. The levels
of carcinoembryonic antigen (CEA), carbohydrate antigen (CA)19-9, and DUPAN-2 were also within normal limits, and exocrine
function of the pancreas (PFD, 75%) was normal. Ultrasonography (US) revealed a hypoechoic tumor in the distal pancreas. Computed
tomography (CT) demonstrated a high-density area 4 cm in diameter with calcification. The serum glucagon level was very high
(2360 pg/ml), but the levels of other hormones such as somatostatin or gastrin were within normal limits, while insulin was
low. Glucagonoma of the pancreas was diagnosed, and distal pancreatectomy with splenectomy was performed. Histological examination
revealed a malignant endocrine tumor, which was immunohistochemically positive for chromogranin A and glucagon. Two months
after the operation, the serum glucagon level had decreased to within normal limits and the hemoglobin level had increased
to 10.4 g/dl. The case of glucagonoma reported here was found through diagnostic examinations of anemia and treated by surgical
resection, by which the patient's anemia was largely alleviated. Therefore, we recommend checking patients who have diabetes
mellitus and anemia in order to diagnose and treat glucagonoma in its early statge.
Received: November 16, 2001 / Accepted: August 3, 2002
RID="*"
ID="*" Offprint requests to: N. Koike 相似文献
994.
Tokuyama H Hayashi K Matsuda H Kubota E Honda M Okubo K Takamatsu I Ozawa Y Saruta T 《Nephrology (Carlton, Vic.)》2003,8(2):65-71
Although acute renal ischaemia alters the production of various paracrines, there has been little investigation examining the role of intrarenal vasoactive substances. In the present study, we investigated the role of intrarenal nitric oxide and prostaglandins in modulating the acute renal hypoperfusion-induced alterations in renal function. After a 90% clipping of the left renal artery for 60 min, the clip was released, and the renal haemodynamics and sodium excretion were evaluated in both clipped and non-clipped kidneys of anaesthetized dogs. Furthermore, the changes in renal contents of nitrate/nitrite (NOx) and prostaglandin E2 (PGE2) were assessed by using the renal microdialysis technique. The release of the clipping elicited a gradual recovery of renal plasma flow and glomerular filtration rate, and a sustained increase in fractional sodium excretion (FENa) in the clipped kidney. Renal interstitial NOx was reduced in both the cortex (from 8.2 +/- 1.1 to 2.5 +/- 0.3 micromol/L, P < 0.01) and medulla (from 10.1 +/- 0.9 to 3.1 +/- 0.2 micromol/L, P < 0.01), but the levels gradually elevated after declamping. The treatment with nitro-l-arginine methylester only modestly impaired the recovery of renal plasma flow (RPF; at hour 4) and glomerular filtration rate (GFR; at hours 3 and 4 after declamping), without affecting FENa. Conversely, the renal PGE2 levels increased prominently upon the onset of ischaemia (medulla, from 149 +/- 19 to 378 +/- 39 pg/mL, P < 0.01; cortex, from 107 +/- 13 to 302 +/- 34 pg/mL, P < 0.01). Furthermore, the pretreatment with a non-specific cyclo-oxygenase (COX) inhibitor, sulpyrine, and a COX-2-specific inhibitor, NS398, prominently inhibited the increases in FENa induced by the acute renal arterial clipping in a similar manner. In conclusion, in acute renal hypoperfusion, nitric oxide (NO) plays a permissive role in the recovery of the renal haemodynamics. In contrast, sustained increases in renal PGE2 in both clipped and non-clipped kidneys indicate that the COX-2-mediated PGE2 contributes importantly to the failure of the sodium reabsorption in response to acute renal hypoperfusion. 相似文献
995.
Slit and glypican-1 mRNAs are coexpressed in the reactive astrocytes of the injured adult brain 总被引:7,自引:0,他引:7
Hagino S Iseki K Mori T Zhang Y Hikake T Yokoya S Takeuchi M Hasimoto H Kikuchi S Wanaka A 《Glia》2003,42(2):130-138
The slit family serves as a repellent for growing axons toward correct targets during neural development. A recent report describes slit mRNAs expressed in various brain regions in adult rats. However, their functions in the adult nervous system remain unknown. In the present study, we investigated whether slit mRNAs were expressed in the cryo-injured brain, using in situ hybridization. All slit family members were expressed at the lesion. Slit2 mRNA was the most intensely expressed in the cells surrounding the necrotic tissue. A double-labeling study showed that slit2 mRNA was expressed in the glial fibrillary acidic protein (GFAP)-positive reactive astrocytes. In addition, glypican-1, a heparan sulfate proteoglycan that serves as a high-affinity receptor for Slit protein, was coexpressed with slit2 mRNA in the reactive astrocytes. These findings suggested that slit2 might prevent regenerating axons from entering into the lesion in concert with glypican-1. 相似文献
996.
SUMMARY: We have investigated the expression of chloride channels by examining the cochlea of mice harboring the enhanced green fluorescence protein (EGFP) gene driven by an 11 kbp human CLC-KB gene promoter. CLC-KB was seen not only on the stria vascularis but on spiral ligament and limbal fibrocytes, interdental cells and satellite cells of spiral ganglion neurons that are known to possess both Na,K-ATPase and the Na-K-Cl co-transporter (NKCC). These results suggest that some fibrocytes possessing both the CLC-KB and the NKCC may be involved in the regulation of cell volume, transport and recycling of Cl- such as is seen in the stria vascularis. Moreover, these fibrocytes may recycle Cl- through CLC that accompany Na+ and K+ into the cell via NKCC. 相似文献
997.
998.
Takiguchi Y Okamura HO Kitamura K Kishimoto S 《The Journal of laryngology and otology》2003,117(8):658-659
Major late complications, following radiotherapy of head and neck carcinomas, such as laryngeal oedema, perichondritis and chondronecrosis usually occur between three and 12 months after treatment. However, the present case displayed necrosis of the laryngo-tracheal cartilage and ulceration of anterior neck skin with a tracheal fistula 44 years after irradiation. The reasons for the long interval between irradiation and late complications may be explained by long-standing hypovascularity and/or infection of the irradiated area. Histological study revealed chondronecrosis without inflammatory cells in the laryngo-tracheal cartilage and bacterial colonization of subcutaneous tissue. Necrotic tissue was removed and tracheostomy was performed. The fistula was almost completely closed using a delto-pectoral cutaneous flap and the clinical course of patient has been good. This paper demonstrates the possibility of laryngo-tracheal necrosis in cases that had received radiation as long ago as 44 years. 相似文献
999.
Takahashi K Merchant SN Miyazawa T Yamaguchi T McKenna MJ Kouda H Iino Y Someya T Tamagawa Y Takiyama Y Nakano I Saito K Boyer P Kitamura K 《The Laryngoscope》2003,113(8):1362-1368
OBJECTIVES/HYPOTHESIS: Although hearing loss is common in MELAS (syndrome of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes), the histopathology of the temporal bone has not been reported. The majority of cases of MELAS are linked to a mitochondrial DNA (mtDNA) mutation at nucleotide 3243. In MELAS, normal mtDNA and mutant mtDNA coexist in a heteroplasmic manner. The purpose of the study was to report the otopathological findings from two patients with MELAS and quantitative mtDNA analysis in the inner ear of one of these patients. STUDY DESIGN: Basic scientific histopathological examination and quantitative mtDNA analysis of the temporal bone. METHODS: Temporal bones were embedded in celloidin and sectioned for light microscopic study. Graphic reconstruction of the cochlea was performed using the method described by Schuknecht. For quantitative mtDNA analysis, total DNA from the membranous part of the inner ear was collected, amplified by polymerase chain reaction, and digested with the restriction enzyme. The percentage of mutant/total mtDNA was measured by the ratio of fluorescence intensity. RESULTS: Histopathological examination revealed severe degeneration of the stria vascularis and degenerative change of spiral ganglion cells in both patients. The quantitative DNA studies showed that the proportion of mutant to wild-type mtDNA was similar in both histologically affected and histologically unaffected tissues within the inner ear. CONCLUSION: Dysfunction of the stria vascularis and spiral ganglion cells causes sensorineural hearing loss in MELAS. 相似文献
1000.