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   1091篇
  免费   51篇
  国内免费   9篇
耳鼻咽喉   40篇
儿科学   75篇
妇产科学   48篇
基础医学   95篇
口腔科学   32篇
临床医学   75篇
内科学   234篇
皮肤病学   41篇
神经病学   58篇
特种医学   15篇
外科学   309篇
综合类   8篇
预防医学   22篇
眼科学   46篇
药学   33篇
中国医学   2篇
肿瘤学   18篇
  2024年   1篇
  2023年   8篇
  2022年   13篇
  2021年   39篇
  2020年   23篇
  2019年   27篇
  2018年   30篇
  2017年   22篇
  2016年   39篇
  2015年   48篇
  2014年   41篇
  2013年   53篇
  2012年   70篇
  2011年   67篇
  2010年   34篇
  2009年   43篇
  2008年   85篇
  2007年   88篇
  2006年   71篇
  2005年   71篇
  2004年   64篇
  2003年   34篇
  2002年   40篇
  2001年   38篇
  2000年   54篇
  1999年   11篇
  1998年   16篇
  1997年   8篇
  1996年   2篇
  1995年   2篇
  1994年   2篇
  1992年   4篇
  1989年   1篇
  1987年   1篇
  1985年   1篇
排序方式: 共有1151条查询结果,搜索用时 15 毫秒
31.
32.
International Ophthalmology - To evaluate anatomical and neuroretinal functional aspects in patients with diabetic macular edema (DME) after intravitreal anti-vascular endothelial growth factor...  相似文献   
33.
34.
Intestinal ischemia/reperfusion (I/R) is a complex phenomenon that causes destruction of both local and remote tissues. The objective of this study was to investigate the possible participation of oxidized low-density lipoproteins (oxLDLs) and inducible nitric oxide synthase (iNOS) expression in renal tissue damage after intestinal I/R. The superior mesenteric artery was blocked for 30 minutes, followed by 24 hours of reperfusion. At the end of the reperfusion period, renal tissues were removed; the presence of oxLDL, superoxide dismutase enzyme activity, malondialdehyde levels, and iNOS expression were evaluated. I/R resulted in positive oxLDL staining in renal tissue. Compared with control rats, tissue from the I/R group showed significantly higher malondialdehyde levels and lower superoxide dismutase enzyme activity. Strong and diffuse iNOS expression was present in the I/R group. Our findings support the hypothesis that I/R of intestinal tissue results in oxidative and nitrosative stress and enhances lipid peroxidation in the end organ. These data show that oxLDL accumulates in rat renal tissue after intestinal I/R. Antioxidant strategies may provide organ protection in patients with reperfusion injury, at least by affecting interactions with free radicals, nitric oxide, and oxLDL. This study demonstrates for the first time that oxLDL may play a role in renal tissue damage after intestinal I/R. Antioxidant strategies may be beneficial for protection from reperfusion injury.  相似文献   
35.
Background and aims. Patients with end stage renal disease (ESRD) have many musculoskeletal abnormalities, including hand dysfunction. The Sollerman test evaluates hand grip function in daily activities. The relationships between Sollerman test (dominant hand) with Duruoz's Hand Index (DHI), Health Assessment Questionnaire (HAQ), and Beck Depression Inventory (BDI) tests have not been investigated previously. The aims of this study are to evaluate hand grip function using the Sollerman test in hemodialysis (HD) patients, correlate this test with other measures evaluating hand function or psychosocial status, and investigate factors that can affect Sollerman test. Methods. One-hundred twenty HD patients (64 male, 56 female, mean age 51 ± 1.4 years, mean duration of HD therapy 5.3 ± 3.7 years) were included in this study. The HAQ, DHI, and BDI scores were determined by standard techniques. All patients underwent the Jamar grip test and Sollerman test for the dominant (D) and non-dominant hand (ND). Results. We found a positive correlation between Sollerman test (dominant hand) with Sollerman test-ND, Jamar-D, and Jamar-ND tests. There were negative correlations between Sollerman test with age, HAQ, BDI, and DHI tests. Conclusions. The relationships between Sollerman test (dominant hand) with DHI, HAQ, and BDI tests have not been investigated previously. This study showed the correlations between the Sollerman test (dominant hand) and other tests (either positive or negative). Psychosocial problems can affect hand functions.  相似文献   
36.
Objectives: This research aimed to evaluate pre-operatively and post-operatively the olfactory function of patients who had undergone surgery in our clinic for chronic nasal blockage via the Connecticut Chemosensory Clinical Research Center (CCCRC) smell test.

Method: Thirty-seven patients (24 females, 13 males) were enrolled in this study. All had undergone surgery in our clinic due to chronic nasal blockage (not for smell dysfunction), having been diagnosed with septal deviation in conjunction with concha bullosa and/or inferior turbinate hypertrophy. This is a prospective study without a control group. The mean age was 33.74?±?8.98 (range =19–54). All of the operations were performed under general anesthesia. CCCRC smell tests were performed on every patient before the operation and at post-operative 1st week, 6th week, 6th month, and 1st year.

Results: In this study, we found that septoplasty, in conjunction with middle concha surgery and/or inferior concha radiofrequency, did not affect the olfactory function negatively.

Conclusion: Although nasal surgery has the potential to affect the smell function negatively, it was found that olfactory function was not affected after the surgery during a considerably long follow-up period. Moreover, an improvement in smell function was detected at post-operative 6th month and 1st year.  相似文献   
37.

Purpose

To present our experience in abdominal transplantations to manage unresectable abdominal neoplasms in children and to describe the role of extensive surgeries in such cases.

Methods

This is a retrospective study of 22 abdominal transplantations in 21 patients for abdominal tumors over 16 years. Transplantation techniques included liver transplant (LT), multivisceral transplant (MVTx), and intestinal autotransplant (IA). Follow-up intervals ranged from 0.3 to 168 months (median 20 months).

Results

LT alone was performed in 15 patients for primary malignant (11) and benign (4) liver tumors. Pathological classification included HB hepatoblastoma (6), HCC hepatocellular cancer (3), hepatic epithelioid hemangioendothelioma HEH (1), angiosarcoma (1), benign vascular tumors (3), and adenoma (1). IA was performed in four patients for lesions involving the root of the mesentery; tumors of the head of pancreas (3) and mesenteric hemangioma (1). MVTx was performed in 2 patients for malignancies; pancreaticoblastoma (1), recurrent hepatoblastoma (1), and in one patient as a rescue procedure after IA failure. Four of the eleven patients who underwent LT for malignant liver tumor had metastatic disease at presentation. Six of them died of recurrent neoplasm (3), transplant-related complications (2), and underlying disease (1). All LT patients who had benign tumors are alive with functioning grafts. All IA patients survived and are on an oral diet, with one patient requiring TPN supplementation. One of the three patients who underwent MVTx died of metastatic disease.

Conclusions

Allo/auto transplantation for abdominal tumors is a valuable modality when conventional treatments fail or are not feasible.
  相似文献   
38.

Purpose

We sought to identify factors associated with increased resource utilization and in-hospital mortality for pediatric liver transplantation (LT).

Methods

Kids’ Inpatient Database (1997–2009) was used to identify cases of LT in patients <20 years old.

Results

Overall, 2905 cases were identified, with an in-hospital survival of 91 %. LT was performed most frequently in < 5 year olds (61 %), females (51 %), and Caucasians (56 %). LT was performed at urban teaching hospitals (97 %) and facilities with children’s units (51 %). Indications included pathologic conditions of the biliary tract (44 %) and inborn errors of metabolism (34 %), though unspecified end stage liver disease was the most common (75 %). Logistic regression found higher mortality in children undergoing LT for malignant conditions (odds ratio: 4.8) and acute hepatic failure (OR 3.4). Cases complicated by renal failure (OR 7.7) and complications of LT (OR 2.7) had higher mortality rates. Resource utilization increased for children with renal failure and those with hemorrhage as a complication of LT, p < 0.05.

Conclusion

Hospital survival is predicted by indication and complications associated with LT. Resource utilization increased with renal failure and complications related to LT. Admission length was sensitive to payer status, hospital characteristics, and UNOS region, whereas total costs were unaffected by payer status or hospital type.
  相似文献   
39.
Purpose The purpose of this study was to compare the effects of anti-adhesion materials in postoperative adhesions. Materials and Methods Rats were assigned to five groups: Group 1: Control. Group 2: chitin layers were used. Group 3: Na-hyaluronate / carboxymethylcellulose layers were used. Group 4: Na-hyaluronate gel was poured into the abdomen. Group 5: methylprednisolone was injected. The adhesion frequency and grade were scored according to Granat. Blood was taken for Hb, AST, BUN and albumin levels determination. Findings The adhesion frequencies (right and left) and grades were as follow in Groups; I: 82%, 91%, 2.63 ± 1.22; II: 8.3%, 25%, 0.58 ± 0.66; III: 17%, 33%, 1.08 ± 1.08; IV: 50%, 58%, 1.41 ± 1.44; V: 50%, 42%, 1.41 ± 1.50. The adhesion phase in all study groups was found significantly low compared to control group, p < 0.05. No difference was observed among serologic and hematological parameters in all groups. Conclusion All the materials used significantly lowered the adhesion frequency and grade.  相似文献   
40.
For both the B2O3-Bi2O3-CaO and B2O3-Bi2O3-SrO glass systems, γ-ray and neutron attenuation qualities were evaluated. Utilizing the Phy-X/PSD program, within the 0.015–15 MeV energy range, linear attenuation coefficients (µ) and mass attenuation coefficients (μ/ρ) were calculated, and the attained μ/ρ quantities match well with respective simulation results computed by MCNPX, Geant4, and Penelope codes. Instead of B2O3/CaO or B2O3/SrO, the Bi2O3 addition causes improved γ-ray shielding competence, i.e., rise in effective atomic number (Zeff) and a fall in half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP). Exposure buildup factors (EBFs) and energy absorption buildup factors (EABFs) were derived using a geometric progression (G–P) fitting approach at 1–40 mfp penetration depths (PDs), within the 0.015–15 MeV range. Computed radiation protection efficiency (RPE) values confirm their excellent capacity for lower energy photons shielding. Comparably greater density (7.59 g/cm3), larger μ, μ/ρ, Zeff, equivalent atomic number (Zeq), and RPE, with the lowest HVL, TVL, MFP, EBFs, and EABFs derived for 30B2O3-60Bi2O3-10SrO (mol%) glass suggest it as an excellent γ-ray attenuator. Additionally, 30B2O3-60Bi2O3-10SrO (mol%) glass holds a commensurably bigger macroscopic removal cross-section for fast neutrons (ΣR) (=0.1199 cm−1), obtained by applying Phy-X/PSD for fast neutrons shielding, owing to the presence of larger wt% of ‘Bi’ (80.6813 wt%) and moderate ‘B’ (2.0869 wt%) elements in it. 70B2O3-5Bi2O3-25CaO (mol%) sample (B: 17.5887 wt%, Bi: 24.2855 wt%, Ca: 11.6436 wt%, and O: 46.4821 wt%) shows high potentiality for thermal or slow neutrons and intermediate energy neutrons capture or absorption due to comprised high wt% of ‘B’ element in it.  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