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   403篇
  免费   2篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   2篇
妇产科学   50篇
基础医学   51篇
口腔科学   15篇
临床医学   18篇
内科学   20篇
神经病学   65篇
特种医学   23篇
外科学   46篇
综合类   1篇
预防医学   11篇
药学   56篇
中国医学   5篇
肿瘤学   51篇
  2023年   1篇
  2022年   3篇
  2021年   17篇
  2020年   5篇
  2019年   3篇
  2018年   9篇
  2017年   5篇
  2016年   12篇
  2015年   18篇
  2014年   20篇
  2013年   35篇
  2012年   53篇
  2011年   51篇
  2010年   25篇
  2009年   13篇
  2008年   21篇
  2007年   23篇
  2006年   22篇
  2005年   17篇
  2004年   17篇
  2003年   9篇
  2002年   3篇
  2001年   9篇
  2000年   5篇
  1999年   3篇
  1998年   2篇
  1997年   4篇
  1995年   1篇
  1994年   2篇
  1992年   1篇
  1991年   4篇
  1989年   1篇
  1976年   1篇
排序方式: 共有415条查询结果,搜索用时 25 毫秒
11.
12.
13.
Adenoid cystic carcinoma of Bartholin glands (BG-ACC) is a rare, slow-growing but a highly aggressive tumor with remarkable capacity for local recurrence and distant metastasis. The purpose of this study was to elucidate our experiences of the diagnosis and treatment of BG-ACC and to analyze the clinical outcomes and prognosis of patients with BG-ACC. A retrospective chart review was performed to assess the demographic information, chief complaints, pathologic features of tumors, primary treatment, and development of local recurrence or distant metastasis, as well as the patient outcome. All patients received surgical excision as the primary treatment, and the diagnosis of BG-ACC was confirmed histopathologically. Three of four patients whose tumors showed pathologic features indicating a high probability of recurrence received adjuvant radiotherapy. These patients did not develop local recurrence, in contrast, one patient who did not receive adjuvant radiotherapy developed local recurrence and distant metastasis on several occasions. All patients who received primary surgical treatment are alive to date. When patients who are more than 40 years of age and who present with symptomatic BG lesions, BG-ACC should be included in the differential diagnosis and biopsy should be performed for histopathologic confirmation. Radical local excision with sufficient negative margins seems to be beneficial for primary treatment. Adjuvant radiotherapy is a reasonable treatment option for patients with high risk factors after surgery or for patients who develop local recurrence.  相似文献   
14.
15.
We report a very rare case of cervical compressive myelopathy by an anomalous bilateral vertebral artery (VA) entering the spinal canal at the C1 level and compressing the spinal cord. A 70-year-old woman had been suffering from progressive gait disturbance. Magnetic resonance imaging revealed that a bilateral VA at the V4 segment had abnormal courses and caused compression to the high cervical cord. VA repositioning was performed by anchoring a suture between the artery and around the arachnoid membrane and dentate ligament, and then, microvascular decompression using a Teflon sponge was done between the VA and the spinal cord. The weakness in the patient improved in the lower extremity after the operation. Anomalous VA could be one of the rare causes of cervical compressive myelopathy. Additionally, an anchoring suture and microvascular decompression around the VA could be a sufficient and safe method to indirectly decompress the spinal canal.  相似文献   
16.

Purpose

The aims of the present study were to compare the biomechanical effects on the adjacent segments after mono-segmental floating fusion with posterior semi-rigid or rigid stabilization, and to evaluate the effect of the amount of fusion mass on the biomechanical differences.

Methods

A detailed, nonlinear L1–S1 finite element model had been developed and validated. Then five models were reconstructed by different fixation techniques on the L3–L4 level: rigid fixation with an interbody spacer (Ti + IS), rigid fixation with a large interbody spacer (Ti + IS_all), semi-rigid fixation with an interbody spacer (PEEK + IS), semi-rigid fixation with a large interbody spacer (PEEK + IS_all), and semi-rigid fixation only (PEEK). Analyses were conducted for the case of erect standing position, flexion, and extension motion.

Results

At L1–L2 and L2–L3, PEEK + IS demonstrated less inter-segmental rotation and nucleus pressure increments from the intact model compared with Ti + IS. The L4–L5 and L5–S1 levels showed slightly higher values with PEEK + IS, but these differences among the instrumented models were not significant. The motion difference based on the fusion mass at the adjacent levels was at most 3 %. All instrumentation cases generated a 55 % higher facet contact force at the lower adjacent level (L4–L5) compared to that of the intact model during 26° extension and the largest increment was detected at the upper adjacent level (L2–L3) in the Ti + IS. Instrumentation with Ti + IS markedly increased the stress in the intervertebral disk at the upper adjacent level, while the stress with PEEK + IS appeared largest at the lower adjacent level.

Conclusions

Posterior instrumentation with semi-rigid rods may lower the incidence of disk and facet degeneration in the upper adjacent segment compared to rigid rods. On the other hand, the possibility of facet degeneration will be similar for all instrumentation devices in the lower adjacent segment in the long-term. The stiffness difference between rigid and semi-rigid rods on the changes in the adjacent motion segments was more crucial than amount of fusion mass.  相似文献   
17.
Kim  Chi Heon  Chung  Chun Kee  Lee  Sun-Ho  Jahng  Tae-Ahn  Hyun  Seung-Jae  Kim  Ki-Jeong  Yoon  Sang Hoon  Kim  Eun-Sang  Eoh  Whan  Kim  Hyun-Jib  Kim  Kyoung-Tae  Sung  Joo-Kyung  Choi  Yunhee 《European spine journal》2016,25(12):4025-4032
Purpose

Simpson grade II removal (coagulation of the dural attachment after gross total removal) of spinal meningioma is considered an acceptable alternative, but increased recurrence after more than 10 years has been reported. More attention must be paid to the long-term surgical outcomes after Simpson grade II removal.

Methods

A retrospective review was performed for 20 patients (M:F = 5:15; age, 59 ± 9 years) with Simpson grade II removal (mean follow-up period, 12.9 years; range 10.0–17.5). Magnetic resonance (MR) imaging was conducted in 17 patients at 88 ± 52 months (range 12–157). During the same period, Simpson grade I removal (removal of the dural origin) was performed in 21 patients (follow-up, 89 ± 87 months; range 9–316). Radiological recurrence was defined as a visible tumor on a follow-up MR image, and clinical tumor recurrence was defined as the recurrence of symptoms.

Results

At the final follow-up, neurological symptoms had improved in 16/20 patients and remained stable in 4/20. A recurrent tumor was detected in one patient due to increased back pain at 92 months postoperative, but the symptom was stable without surgery until the last follow-up (124 months). The radiological and clinical recurrence-free survival periods were 150 ± 7 months (95 % CI 136–163) and 204 ± 6 months (95 % CI 193–215), respectively. There was no recurrence after Simpson grade I removal, whereas neurological deterioration occurred in two patients after surgery.

Conclusions

Simpson grade II removal may be an alternative option if the risk of complications with Simpson grade I removal is expected to be high.

  相似文献   
18.
Hyperpigmentation disorders such as freckles and senile lentigines in the skin are associated with abnormal accumulation of melanin pigments. In this study, two lignan constituents were isolated from Saururus chinensis Baill (Saururaceae) as inhibitors of cellular melanin production by bioassay‐guided fractionations. The active constituents were manassantin A and B that dose‐dependently inhibited melanin production in α‐melanocyte stimulating hormone (α‐MSH)‐activated melanoma B16 cells with IC50 values of 13 nm and 8 nm , respectively. Arbutin as a positive control exhibited an IC50 value of 96 µm on α‐MSH‐induced melanin production. Further, manassantin A inhibited forskolin‐ or 3‐isobutyl‐1‐methylxanthine (IBMX)‐induced melanin production with IC50 values of 14 nm or 12 nm , respectively. Manassantin A decreased cellular amounts of IBMX‐inducible tyrosinase protein but could not affect the catalytic activity of cell‐free tyrosinase, a key enzyme in the biosynthetic pathway of melanin pigments. Finally, this study could provide a pharmacological potential of S. chinensis in hyperpigmentation disorders. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
19.
20.
The aim of this trial was to investigate the efficacy and toxicity of combination chemotherapy with etoposide and ifosfamide (ETI) in the management of heavily pretreated recurrent or persistent epithelial ovarian cancer (EOC). Patients with recurrent or persistent EOC who had measurable disease and at least two prior chemotherapy participating in this phase II trial were to receive etoposide at a dose of 100 mg/m2/day intravenously (IV) on days 1 to 3 in combination with ifosfamide 1 g/m2/day IV on days 1 to 5, every 21 days. Thirty-seven patients were treated; about 78% had previously received more than two separate regimens. The response rate (RR) was 18.9% and median duration of response was 7 months (range, 1-15). Treatment free interval prior to ETI (TFI) has significant correlation with RR rate (P=0.034). Patients (n=6) with TFI ≥6 months had 50% of RR, while patients (n=31) with TFI <6 months had 12.9%. Median survival was 9 months at a median follow-up of 9.2 months. Grade 3 or 4 toxicities included neutropenia in 20.1% of the 139 cycles of ETI, anemia in 7.2% and thrombocytopenia in 8.6%. The ETI produces relatively low toxicity and modest activity in heavily pretreated recurrent or persistent EOC. This is significant in patients with TFI ≥6 months.  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