全文获取类型
收费全文 | 8276篇 |
免费 | 315篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 273篇 |
儿科学 | 349篇 |
妇产科学 | 400篇 |
基础医学 | 542篇 |
口腔科学 | 291篇 |
临床医学 | 698篇 |
内科学 | 2042篇 |
皮肤病学 | 119篇 |
神经病学 | 416篇 |
特种医学 | 328篇 |
外科学 | 2018篇 |
综合类 | 124篇 |
预防医学 | 172篇 |
眼科学 | 302篇 |
药学 | 302篇 |
中国医学 | 21篇 |
肿瘤学 | 244篇 |
出版年
2024年 | 2篇 |
2023年 | 75篇 |
2022年 | 106篇 |
2021年 | 239篇 |
2020年 | 136篇 |
2019年 | 166篇 |
2018年 | 202篇 |
2017年 | 171篇 |
2016年 | 271篇 |
2015年 | 318篇 |
2014年 | 431篇 |
2013年 | 506篇 |
2012年 | 640篇 |
2011年 | 587篇 |
2010年 | 395篇 |
2009年 | 397篇 |
2008年 | 598篇 |
2007年 | 668篇 |
2006年 | 587篇 |
2005年 | 595篇 |
2004年 | 502篇 |
2003年 | 430篇 |
2002年 | 338篇 |
2001年 | 47篇 |
2000年 | 23篇 |
1999年 | 23篇 |
1998年 | 40篇 |
1997年 | 27篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有8641条查询结果,搜索用时 15 毫秒
41.
N-acetylcysteine reduces lung reperfusion injury after deep hypothermia and total circulatory arrest 总被引:3,自引:0,他引:3
OBJECTIVE: We hypothesized that the use of N-acetylcysteine would ameliorate the lung reperfusion injury observed after deep hypothermia and total circulatory arrest (DHTSA). METHODS: Experiments were carried out on 12 adult mongrel dogs of either sex weighing 25 to 30 kg. The animals were randomly divided into two groups of six animals each. All animals were cooled to an esophageal temperature of 15 degrees C during 30 minutes and underwent 60 minutes of DHTSA, followed by the reinstitution of cardiopulmonary bypass (CPB) and rewarming. Before rewarming, while 100 mL physiologic saline solution was added into the pump in group I, 50 mg/kg N-acetylcysteine(NAC) was given in group II. Heart rate, mean arterial pressure, pulmonary arterial pressure, left atrial pressure, central venous pressure, and cardiac output were recorded. To measure lung tissue malondialdehyde (MDA), water content and polymorphonuclear leukocytes (PMNs) count, lung tissue samples were taken before CPB and after weaning CPB. In addition, alveolar-arterial oxygen difference (AaDO(2))()for tissue oxygenation was calculated by obtaining arterial blood gas samples. Dynamic lung compliance (DLC) was measured before CPB and after CPB. RESULTS: MDA levels before CPB of 44.2 +/- 3.9 nmol/g tissue rose to 76.6 +/- 5.6 nmol/g tissue after weaning CPB in group I (p = 0.004). In group II also, the MDA levels increased from 43.5 +/- 4.2 to 57.4 +/- 5.6 nmol MDA/g tissue after weaning CPB (p = 0.006). The MDA increase in group II after CPB was found to be significantly lower than in group I (p = 0.006). The wet-to-dry lung weight ratio in the NAC group was 5.1 +/- 0.2, significantly less than in the control group (5.9 +/- 0.3), (p = 0.004). AaDO(2) significantly increased in the group I and II (p = 0.002 and p = 0.002, respectively); this elevation in group I was significant than in group II (p = 0.044). In histopathological examination, it was observed that neutrophil counts in the lung parenchyma rose significantly after CPB in both groups (p < 0.001). The increase in group I was significantly larger than group II (p < 0.001). CONCLUSIONS: Results represented in our study indicate that addition of NAC into the pump after DHTSA can reduce lung reperfusion injury. 相似文献
42.
Comparison of WHO 1973, WHO/ISUP 1998, WHO 1999 grade and combined scoring systems in evaluation of bladder carcinoma 总被引:2,自引:0,他引:2
OBJECTIVES: To compare WHO 1973, WHO/ISUP 1998 and WHO 1999 histologic grading systems, and also to evaluate the primary (most common) and secondary (second most common) patterns of cancer growth according to these three grading systems. MATERIAL AND METHODS: The study consisted of 87 bladder transurethral resections that were classified as grade 1, 2 and 3, and papillary urothelial neoplasm of low malignant potential (PUNLMP), low grade (LG) and high grade (HG) carcinoma considering WHO 1973 and WHO/ISUP, respectively. The WHO 1999 system was subdivided high grade into grades 2 and 3 (HG-2 and HG-3). For combined scoring, primary (most common) and secondary (second most common) grades according to extension were recorded for three grading systems. The number was repeated when only grade was seen in all extension of the tissue examined. A final combined score was obtained which ranged from 2 to 6 for the WHO 1973 and WHO/ISUP 1998 systems and from 2 to 8 for the WHO 1999 schema. The TNM system was used for the pathologic staging. RESULTS: When considering the pathological stage, there were statistical differences between the WHO 1973 grades (p=0.011 and p=0.000), and LG and HG carcinomas of WHO/ISUP 1998 (p=0.000) and also the WHO 1999 grades (p=0.010 and p=0.003), except PUNLMP. Regarding the combined scoring, significant differences were found between score 4 (2+2) and 5 (2+3) of WHO 1973 (p=0.014) and score 5 (LG+HG) and 6 (HG+HG) of WHO/ISUP 1998 (p=0.011). There was also a significant difference between scores 4 and 6, and 6 and 8 of the WHO 1999 combined scoring system (p=0.019 and p=0.019). WHO 1973, WHO/ISUP 1998 and WHO 1999 systems were positively correlated with the pathological stage (r(s)=0.30, r(s)=0.52 and r(s)=0.50, respectively), whereas there was weak association between the combined scoring systems and stage (r(s)=0.20, r(s)=0.18 and r(s)=0.19). Comparing these grading systems, the grade 2 of WHO 1973 was subdivided into LG and HG in WHO/ISUP 1998 and also LG-1and HG-2 in WHO 1999 systems. The group of HG carcinoma in WHO/ISUP 1998 which was subdivided into HG-2 and HG-3 in the WHO 1999 system was different statistically in relation to the stage. CONCLUSIONS: Our results revealed that the WHO 1999 system may be more useful to evaluate the bladder carcinoma histopathologically in comparison to the WHO 1973 and WHO/ISUP 1998 systems. 相似文献
43.
Ozgün H Boylu S Cevikel MH Yenisey C Erpek H Culhaci N Demirkiran AE 《ANZ journal of surgery》2004,74(3):158-163
Background: Elevated intra‐abdominal pressure and colostomy have adverse effects on colonic anastomoses. The aim of the present study was to investigate the effects of laparoscopic colon surgery with and without diverting colostomy on healing of colonic anastomoses in an experimental model. Methods: Thirty‐six male rats were divided into three equal groups: group 1, control (colonic anastomosis and anaesthesia for 180 min only); group 2, 180 min pneumoperitoneum and colonic anastomosis; and group 3, similar to group 2 with a proximal colostomy. On day 7, bursting pressures, tissue hydroxyproline and nitric oxide concentrations and histopathological inflammation scores were determined and compared. Results: Mean bursting pressures were higher in the control group than the two pneumoperitoneum groups (P = 0.0003). Mean tissue hydroxyproline concentrations showed no difference (P > 0.05). Mean tissue nitric oxide concentrations were significantly increased in the control group (P = 0.0013). Histopathological scores demonstrated increased inflammatory response in group 3 compared to the controls (P = 0.0009). Conclusion: Pneumoperitoneum delays collagen maturation and impairs anastomotic strength in the colon. Following pneumoperitoneum, performance of a diverting loop colostomy to protect the anastomosis will not have additional detrimental effects on anastomotic healing. 相似文献
44.
Identification of fluocinolone acetonide to prevent paclitaxel‐induced peripheral neuropathy 下载免费PDF全文
Aysel Cetinkaya‐Fisgin Min Geol Joo Xiang Ping Nitish V. Thakor Cengizhan Ozturk Ahmet Hoke In Hong Yang 《Journal of the peripheral nervous system : JPNS》2016,21(3):128-133
Paclitaxel (PTX) is among the most commonly used cancer drugs that cause chemotherapy‐induced peripheral neuropathy (CIPN), a debilitating and serious dose‐limiting side effect. Currently, no drugs exist to prevent CIPN, and symptomatic therapy is often ineffective. In order to identify therapeutic candidates to prevent axonal degeneration induced by PTX, we carried out a phenotypic drug screening using primary rodent dorsal root ganglion sensory neurons. We identified fluocinolone acetonide as a neuroprotective compound and verified it through secondary screens. Furthermore, we showed its efficacy in a mouse model of PTX‐induced peripheral neuropathy and confirmed with four different cancer cell lines that fluocinolone acetonide does not interfere with PTX's antitumor activity. Our study identifies fluocinolone acetonide as a potential therapy to prevent CIPN caused by PTX. 相似文献
45.
Karaci AR Aydemir NA Harmandar B Sasmazel A Saritas T Tuncel Z Yekeler I 《Journal of cardiac surgery》2012,27(1):93-98
Abstract Objective: This study assesses surgical procedures, operative outcome, and early and intermediate‐term results of infective valve endocarditis in children with congenital heart disease. Methods: Seven consecutive children (five females, two males; mean age, 10.8 years) who underwent surgery for infective valve endocarditis between 2006 and 2010 were included in the study. The aortic and mitral valves were affected in two and tricuspid in five patients. Indications for operation included cardiac failure due to atrioventricular septal rupture, severe tricuspid valve insufficiency, and septic embolization in one, moderate valvular dysfunction with vegetations in three (two tricuspid, one mitral), and severe valvular dysfunction with vegetations in the other three patients (two tricuspid, one mitral). The pathological microorganism was identified in five patients. Tricuspid valve repair was performed with ventricular septal defect (VSD) closure in five patients. Two patients required mitral valve repair including one with additional aortic valve replacement. Results: There were no operative deaths. Actuarial freedom from recurrent infection at one and three years was 100%. Early echocardiographic follow‐up showed four patients to have mild atrioventricular valve regurgitation (three tricuspid and one mitral) and three had no valvular regurgitation. No leakage from the VSD closure or any valvular stenosis was detected postoperatively. Conclusions: Mitral and tricuspid valve repairs can be performed with low morbidity/mortality rates and satisfactory intermediate‐term results in children with infective valve endocarditis . (J Card Surg 2012;27:93‐98) 相似文献
46.
Akman T Binbay M Ozgor F Ugurlu M Tekinarslan E Kezer C Aslan R Muslumanoglu AY 《BJU international》2012,109(9):1384-1389
Study Type – Therapy (case control) Level of Evidence 3b What's known on the subject? and What does the study add? Recently European Association of Urology 2011 guidelines on urolithiasis recommended retrograde intrarenal surgery as the second‐line therapy for the treatment of kidney stones <10 mm in diameter. This study shows that retrograde intrarenal surgery may be an alternative therapy to percutaneous nephrolithotomy, with acceptable efficacy and low morbidity for 2–4 cm stones.
OBJECTIVE
- ? Currently, the indications for retrograde intrarenal surgery (RIRS) have been extended due to recent improvements in endoscopic technology. In this study, we compare the outcomes of percutaneous nephrolithotomy (PCNL) and RIRS in the treatment of 2–4 cm kidney stones.
MATERIALS AND METHODS
- ? Between September 2008 and January 2011, 34 patients who had renal stones ranging from 2 to 4 cm in diameter were treated with RIRS. The outcomes of these patients were compared with patients who underwent PCNL using matched‐pair analysis (1:1 scenario).
- ? The matching parameters were the size, number and location of the stones as well as age, gender, body mass index, solitary kidney, degree of hydronephrosis, presence of previous shock wave lithotripsy and open surgery.
- ? Data were analysed using Fisher's exact test, Student's t test and the Mann–Whitney U test.
RESULTS
- ? Stone‐free rates after one session were 73.5% and 91.2% for RIRS and PCNL respectively (P= 0.05). Stone‐free rate in the RIRS group improved to 88.2% after the second procedure.
- ? Mean operation duration was 58.2 (±) 13.4 min in the RIRS group but 38.7 (±) 11.6 min in the PCNL group (P < 0.0001). Blood transfusions were required in two patients in the PCNL group.
- ? Overall complication rates in the PCNL group were higher, but the differences were not statistically significant. Hospitalization time was significantly shorter in the RIRS group (30.0 + 37.4 vs 61.4 + 34.0 h, respectively; P < 0.001).
CONCLUSION
- ? Satisfactory outcomes can be achieved with multi‐session RIRS in the treatment of 2–4 cm renal stones. RIRS can be used as an alternative treatment to PCNL in selected cases with larger renal stones.
47.
Mustafa Girgin Burhan Hakan Kanat Refik Ayten Ziya Cetinkaya Zekiye Kanat Ahmet Bozda? Ahmet Turkoglu Yavuz Selim Ilhan 《International surgery》2012,97(4):288-292
Pilonidal disease has been treated surgically and by various other methods for many years. The most important problem associated with such treatment is recurrence, but cosmetic outcome is another important issue that cannot be ignored. Today, crystallized phenol is recognized as a treatment option associated with good medical and cosmetic outcomes. We hypothesized that the addition of laser depilation to crystallized phenol treatment of pilonidal disease might increase the rate of success, and this study aimed to determine if the hypothesis was true. Patients who were treated with crystallized phenol and 755-nm alexandrite laser depilation were retrospectively analyzed. In total, 42 (31 male and 11 female) patients were treated with crystallized phenol and alexandrite laser depilation and were followed up between January 2009 and January 2012. In all, 38 patients (90.5%) had chronic disease and 4 (9.5%) had recurrent disease. Among the patients, 26 (61.9%) recovered following 1 crystallized phenol treatment, and the remaining patients had complete remission following repeated treatment. Some patients needed multiple treatments, even up to 8 times. None of the patients had a recurrence during a mean 24 months (range, 6–30 months) of follow-up. Whatever method of treatment is used for pilonidal disease, hair cleaning positively affects treatment outcome. The present results support the hypothesis that the addition of laser depilation (which provides more permanent and effective depilation than other methods) to crystallized phenol treatment (a non-radical, minimally invasive method associated with very good cosmetic results) can increase the effectiveness of the treatment and also reduce the recurrence rate of the disease. 相似文献
48.
The aim of this study was to evaluate the effects of the novel free radical scavenger caffeic acid phenethyl ester (CAPE) on extracorporeal shock wave lithotripsy (ESWL) induced renal impairment. The study was performed using 30 rabbits which were divided into two groups, each exposed to 3,000 shock waves at 18 kV: (1) control group, (2) ESWL+CAPE treated group. Malodialdehyde (MDA), urine N-acetyl--glucosaminidase (NAG) activity, uric acid and white cell counts were used as markers of oxidative stress. Following shock wave exposure there was a significant rise in MDA, NAG and uric acid and white cell counts. CAPE reduced the rise in MDA, NAG, uric acid and white cell counts. Thus CAPE treatment to a great extent prevented the induction of these renal changes. Our results suggest that the antioxidant capacity of the kidney tissue was reduced after ESWL treatment and that the tissue was exposed to oxidant stress. We conclude that CAPE treatment provided significant protection against ESWL induced free radical damage. 相似文献
49.
Altunkaya H Ozer Y Demirel CB Ozkocak I Keser S Bayar A 《Archives of orthopaedic and trauma surgery》2005,125(9):609-613
Introduction The aim of the study was to demonstrate the possible effects of preoperative intra-articular, intravenous, or intrathecal administration of morphine on postoperative pain management.Materials and methods Sixty patients undergoing arthroscopic menisectomy were included. Spinal anesthesia was performed in the lateral decubitus position with 3 ml of 0.5% hyperbaric bupivacaine, and the patients were randomized into 4 groups. The IVM (intravenous, iv, morphine) group received 3 mg of iv morphine after completion of spinal anesthesia, the ITM (intrathecal morphine) group received 0.3 mg of morphine together with bupivacaine during spinal anesthesia, the IAM (intra-articular morphine) group received 3 mg intra-articular morphine diluted in 10 ml of saline after spinal anesthesia had been induced but 15 min before surgery, while the C (control) group did not receive any drugs in addition to spinal anesthesia. The sensory block level was determined 15 min after spinal anesthesia. Pain at rest (by visual analogue scale, VAS) and pain at 30° of flexion (by verbal rating scale, VRS) were evaluated during each of the first 2 h of the postoperative period and once every 4 h thereafter until 24 h. In each group; the number of patients in need of analgesics, the timing of the first analgesic intake (duration of analgesia), and the cumulative dose of analgesics were recorded.Results The mean duration of analgesia in the IAM group was significantly longer and the mean analgesic intake was significantly lower when compared with the other groups (p<0.05). The mean VAS value of the ITM group at the 4th postoperative hour was significantly lower than that of the other groups. Mean VAS values at 8 and 12 h and mean VRS values at 4 and 8 h were significantly lower in the ITM and IAM groups (p<0.05). The ITM group had the highest rates of nausea, vomiting, pruritus, and headache (p<0.05).Conclusion It was concluded that the preoperative administration of morphine, either intrathecally or intra-articularly, provides postoperative pain relief. Of these two, the intra-articular route seems to be superior in terms of fewer side-effects (nausea, vomiting, and pruritus), longer duration of analgesia, and reduction of total need for analgesics. 相似文献
50.
Mesenchymal hamartoma is an uncommon cystic mass of the liver which occurs primarily in children. There are a few reports
of its occurrence in adulthood. Here, we present two cases in female patients, 54 and 51 years old. Radiological examinations
in both patients showed multiple cystic lesions in the liver. Surgically, total cystectomy was performed in the first patient,
while an unroofing procedure was done in the second patient (due to misdiagnosis of the lesion as a simple cyst of the liver).
On microscopic examinations of the lesion in each patient, a multilocular cyst was observed, lined by flattened epithelium
and surrounded by a mesenchymal component composed of mature connective tissue, arterial and venous vascular structures, peripheral
nerve bundles, and ductal structures. An immunohistochemical panel consisting of desmin, smooth-muscle actin, S-100, vimentin,
CD34, carcinoembryonic antigen, pancytokeratin, cytokeratin 7, cytokeratin 8, cytokeratin 17, cytokeratin 18, cytokeratin
19, and cytokeratin 20 was applied to paraffin sections. Immunoreactivity for cytokeratin 7 and cytokeratin 19 was observed
in cystic epithelium and ductal structures. Focal and patchy desmin immunoreactivity was observed in connective tissue. S-100
was positive only in peripheral nerve bundles. In conclusion, mesenchymal hamartoma of the liver in adulthood is a localized
tumoral abnormality that precedes birth, and which has delayed clinical presentation. These lesions seems to be related to
a maturation process. During this period of maturation, immature edematous stroma rich in mucopolysaccharides may convert
to mature paucicellular hyalinized connective tissue. This maturation process may be also related to loss of premalignant
potential of these tumors. 相似文献