首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   191篇
  免费   6篇
耳鼻咽喉   6篇
儿科学   11篇
妇产科学   4篇
基础医学   20篇
口腔科学   4篇
临床医学   21篇
内科学   48篇
皮肤病学   2篇
神经病学   20篇
特种医学   11篇
外科学   25篇
综合类   2篇
预防医学   9篇
眼科学   1篇
药学   5篇
肿瘤学   8篇
  2023年   1篇
  2022年   4篇
  2021年   1篇
  2020年   3篇
  2019年   6篇
  2017年   2篇
  2016年   3篇
  2015年   6篇
  2014年   4篇
  2013年   11篇
  2012年   9篇
  2011年   12篇
  2010年   11篇
  2009年   4篇
  2008年   8篇
  2007年   8篇
  2006年   6篇
  2005年   18篇
  2004年   9篇
  2003年   4篇
  2002年   2篇
  2001年   6篇
  2000年   5篇
  1999年   7篇
  1998年   2篇
  1997年   6篇
  1996年   5篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   5篇
  1989年   1篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
  1967年   1篇
排序方式: 共有197条查询结果,搜索用时 0 毫秒
91.
92.
This is a case report of a 69-year-old male patient referred to the ENT out patients with right-sided epistaxis and hipoacusis. Fibroptic examination reveals a cystic lesion at the exit of the right eustachian. A CT scan is informed as a well delimited and rounded-shaped tumour compatible with lymphoma. Excisional biopsy by a nasal rigid endoscopy is practiced and the histology result is Warthin's tumour. The nasopharynx is a rather unusual location for this type of tumours, almost exclusive in origin of major salivary glands. It's highlighted the unforeseeable histological diagnosis in this particular anatomical region, where the clinical differential diagnosis is broad and the access difficult.  相似文献   
93.
BACKGROUND: Traditional teaching assumes that the distal arterial tree is maximally dilated in patients with critical limb ischemia (CLI). Endovascular or arterial bypass procedures are the commonly used interventions to increase distal perfusion. However, other forms of treatment such as spinal cord stimulation or intermittent pneumatic compression (IPC) have been shown to improve limb salvage rates. This prospective study was designed to determine if the use of IPC increases popliteal, gastrocnemial, collateral arterial, and skin blood flow in patients with CLI. METHODS: Twenty limbs with CLI in 20 patients (mean age, 74 years) were evaluated with duplex ultrasound scans and laser Doppler fluxmetry in the semi-erect position before, during, and after IPC. One pneumatic cuff was applied on the foot and the other on the calf. The maximum inflation pressure was 120 mm Hg and was applied for 3 seconds at three cycles per minute. All patients had at least two-level disease by arteriography. Fourteen limbs were characterized as inoperable, and six were considered marginal for reconstruction. Flow volumes were measured in the popliteal, medial gastrocnemial, and a genicular collateral artery. Skin blood flux was measured on the dorsum of the foot at the same time. RESULTS: Significant flow increase during the application of IPC was found in all three arteries (18/20 limbs) compared with baseline values (P < .02). The highest change was seen in the popliteal, followed by the gastrocnemial and the collateral artery. After the cessation of IPC, the flow returned to baseline. This was attributed to the elevation of time average velocity, as the diameter of the arteries remained unchanged. The skin blood flux increased significantly as well (P < .03). In the two limbs without an increase in the arterial or skin blood flow, significant popliteal vein reflux was found. Both limbs were amputated shortly after. CONCLUSIONS: IPC increases axial, muscular, collateral, and skin blood flow in patients with CLI and may be beneficial to those who are not candidates for revascularization. Patients with significant venous reflux may not benefit from IPC. This supports the theory that one of the mechanisms by which IPC enhances flow is by increasing the arteriovenous pressure gradient.  相似文献   
94.
Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), some organochlorinated pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCD), were analyzed in yolk sacs of kittiwake (Rissa tridactyla) hatchlings from Kongsfjorden at Svalbard (Norwegian Arctic; 79 degrees N) and from Runde, an island on the coast of Norway (62 degrees N). Retinol (vitamin A), retinyl palmitate, and alpha-tocopherol (vitamin E) were measured in plasma and liver of the hatchlings to examine whether these vitamins were associated with the POPs. Higher levels of PCBs and OCPs were found in hatchlings from Kongsfjorden than in hatchlings from Runde. However, HBCD levels were significantly lower in hatchlings from Kongsfjorden compared to those in hatchlings from Runde. No differences between the two populations of kittiwake hatchlings were found regarding levels of PBDEs. In comparison with seabirds from other European waters and the Canadian Arctic, the kittiwakes seemed to have relatively high levels of PBDEs and HBCD. No effects on morphological variables or vitamin levels by the POPs were revealed, but multivariate regression indicated that liver tocopherol levels may be influenced by POPs.  相似文献   
95.
Citrullus vulgaris (watermelon) is a fruit with prophylactic and therapeutic potentials. In an attempt to maximize these potentials, the seed and rind are now often consumed together with the pulp. This study aimed at evaluating the implications of such consumption. Study involved the use of 35 Wistar rats grouped into seven with a control group administered distilled water, and the other groups administered varying concentrations of the pulp and whole fruit for 28 days. Alanine and aspartate aminotransferase (ALT, AST) were assayed in the serum and liver. Total protein of the serum and selected tissues was determined and malondialdehyde (MDA) level measured. Phytochemical screening revealed the presence of steroids, saponin, alkaloids, flavonoids, and terpenoids in both whole fruit and pulp. Significant increases (p < 0.05) were seen in the liver ALT levels while there was a decreased (p < 0.05) intestinal total protein in the treatment groups. No significant (p ? 0.05) difference was seen in the serum and pancreas MDA levels while an increased (p < 0.05) intestinal MDA level was observed. Increased liver ALT levels in all the treatment groups might be due to high glutamate levels of C. vulgaris. Decreased (p ? 0.05) intestinal total protein might be indicative of protein loss, while elevated (p < 0.05) intestinal MDA levels in the groups administered whole fruit is suggestive of a defect in absorption at the intestinal epithelium. Hence, whole fruit consumption of C. vulgaris should be done with caution as it has potential to cause intestinal oxidative stress.  相似文献   
96.
97.
Baker TA  Aaron JM  Borge M  Pierce K  Shoup M  Aranha GV 《American journal of surgery》2008,195(3):386-90; discussion 390
BACKGROUND: This study evaluated the role of interventional radiology (IR) procedures to manage complications after pancreaticoduodenectomy. METHODS: A retrospective review was made of the records of patients with postsurgical complications managed with IR. RESULTS: Among the 440 patients reviewed, the mortality, morbidity and reoperation rates were 1.6%, 36%, and 2%, respectively. Complications occurred in 159 patients, of which 39 (25%) required > or = 1 IR procedures. Of those 39 patients, 72% underwent percutaneous drainage of an intra-abdominal abscess, 18% underwent percutaneous biliary drainage, and 10% underwent angiography for gastrointestinal bleeding or pseudoaneurysm. The reoperation rate among the 159 patients with complications was 6% (n = 9). Reoperation was avoided in 90% of patients receiving IR. Four patients underwent reoperation despite IR for persistent abscess, pancreatic fistula, anastomotic disruption, or mesenteric venous bleeding. CONCLUSIONS: The majority of complications occurring after pancreaticoduodenectomy can be managed effectively using IR, thus minimizing morbidity and the need for reoperation.  相似文献   
98.
Medical management of a female passenger with acute stroke aboard a cruise ship at the sea allowed a fast evacuation towards a stroke unit by an helicopter staffed with an emergency medical doctor. Fibrinolysis begun in a short delay after magnetic resonance imaging.  相似文献   
99.
100.
Reelin is a secreted protein that regulates brain layer formation during embryonic development. Reelin binds several receptors, including two members of the low-density lipoprotein (LDL) receptor family, the apolipoprotein E receptor 2 (ApoER2) and the very-low-density lipoprotein receptor (VLDLR). Despite the high level of expression of Reelin and ApoER2 in the postnatal brain, their functions in the adult CNS remain elusive. Here, using electrophysiological, immunocytochemical, and biochemical approaches in cultured postnatal hippocampal neurons, we show that Reelin controls the change in subunit composition of somatic NMDA glutamate receptors (NMDARs) during maturation. We found that maturation is characterized by the gradual decrease of the participation of NR1/2B receptors to whole-cell NMDAR-mediated currents. This maturational change was mirrored by a timely correlated increase of both Reelin immunoreactivity in neuronal somata and the amount of secreted Reelin. Chronic blockade of the function of Reelin with antisense oligonucleotides or the function-blocking antibody CR-50 prevented the decrease of NR1/2B-mediated whole-cell currents. Conversely, exogenously added recombinant Reelin accelerated the maturational changes in NMDA-evoked currents. The maturation-induced change in NMDAR subunits also was blocked by chronic treatment with an inhibitor of the Src kinase signaling pathway or an antagonist of the LDL receptors, but not by inhibitors of another class of Reelin receptor belonging to the integrin family. Consistent with these results, immunocytochemistry revealed that NR1-expressing neurons also expressed ApoER2 and VLDLR. These data reveal a new role for Reelin and LDL receptors and reinforce the idea of a prominent role of extracellular matrix proteins in postnatal maturation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号