全文获取类型
收费全文 | 800篇 |
免费 | 79篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 49篇 |
妇产科学 | 7篇 |
基础医学 | 172篇 |
口腔科学 | 28篇 |
临床医学 | 59篇 |
内科学 | 156篇 |
皮肤病学 | 20篇 |
神经病学 | 17篇 |
特种医学 | 81篇 |
外科学 | 119篇 |
综合类 | 17篇 |
预防医学 | 28篇 |
眼科学 | 22篇 |
药学 | 30篇 |
肿瘤学 | 68篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 16篇 |
2014年 | 21篇 |
2013年 | 31篇 |
2012年 | 23篇 |
2011年 | 17篇 |
2010年 | 55篇 |
2009年 | 38篇 |
2008年 | 27篇 |
2007年 | 41篇 |
2006年 | 38篇 |
2005年 | 33篇 |
2004年 | 28篇 |
2003年 | 31篇 |
2002年 | 31篇 |
2001年 | 30篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 38篇 |
1997年 | 42篇 |
1996年 | 39篇 |
1995年 | 36篇 |
1994年 | 22篇 |
1993年 | 21篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 14篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1954年 | 1篇 |
排序方式: 共有885条查询结果,搜索用时 281 毫秒
61.
Hospital volume and hospital mortality for esophagectomy 总被引:18,自引:0,他引:18
van Lanschot JJ Hulscher JB Buskens CJ Tilanus HW ten Kate FJ Obertop H 《Cancer》2001,91(8):1574-1578
BACKGROUND: Hospital mortality after esophagectomy has decreased from 29% to 7.5% over the last decades because of improved surgical techniques and better perioperative care. Suggestions have been made that a further decrease in hospital mortality may be achieved by centralization of esophagectomies in high volume centers. METHODS: The effect of hospital volume on hospital mortality after esophagectomy in the Netherlands was analyzed based on data from the Dutch National Medical Registry and the Dutch Network and National Database for Pathology over the period 1993-1998. RESULTS: Annually, approximately 310 (range, 264-321) esophagectomies are performed in the Netherlands. Fifty-two percent are performed in 43-55 low volume centers (1-10 resections a year). Six percent are performed in 1-3 medium volume centers (11-20 resections a year). The remainder (42%) is performed in two high volume centers (> 50 resections a year). Hospital mortality is 12.1%, 7.5% and 4.9% respectively (P < 0.001). The high volume centers seem to see slightly more advanced tumors than the low and medium volume centers. CONCLUSIONS: There is a significant (inverse) relation between hospital mortality and hospital volume for esophageal resection in the Netherlands. Although hospital mortality is not the only measure for quality of care, these data suggest a potential beneficial effect to centralization of esophagectomy in the Netherlands. 相似文献
62.
van den Boogert J van Hillegersberg R van Staveren HJ de Bruin RW van Dekken H Siersema PD Tilanus HW 《British journal of cancer》1999,79(5-6):825-830
5-Aminolaevulinic acid (ALA)-induced, protoporphyrin IX (PpIX)-mediated photodynamic therapy (PDT) is an experimental treatment modality for (pre)malignant oesophageal lesions. This study aimed to optimize the time of illumination after ALA administration. Six groups of eight rats received 200 mg kg(-1) ALA orally, eight rats served as controls. Illumination was performed at 1, 2, 3, 4, 6 or 12 h after ALA administration with a 1-cm cylindrical diffuser placed in a balloon catheter (laser parameters: 633 nm, 25 J radiant energy, power output 100 mW). During illumination, fluorescence measurements and light dosimetry were performed. Animals were sacrificed at 48 h (n = 4) or 28 days (n = 4) after PDT. At day 28, an oesophagogram was performed. Largest PpIX fluorescence was found at 3 h after ALA administration. In vivo fluence rate was three times higher than the calculated incident fluence rate. At 48 h after PDT, major epithelial damage was found in all animals illuminated at 2 h, whereas less epithelial damage was found at 3-6 h and none at 1 and 12 h. In animals illuminated at 4, 6 and 12 h, but not at 2 h, oesophagograms showed severe dilatations and histology showed loss of Schwann cells. These results demonstrate that the choice of time interval between ALA administration and illumination is critical for achieving epithelial damage without oesophageal functional impairment. A short interval of 2-3 h seems to be most appropriate. 相似文献
63.
MG Magaji JA Anuka I Abdu-Aguye AH Yaro I M Hussaini 《African journal of traditional, complementary, and alternative medicines》2008,5(2):147-153
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant. 相似文献
64.
Chest computed tomography (CT), including high-resolution CT with thin (1.5-mm) sections was used to evaluate proved (pathologically or clinically) lymphangitic spread (LS) of tumor in 12 patients. These appearances were compared with thin-section scans obtained in 11 healthy subjects. Thin-section CT demonstrated findings consistent with thickening of the normal lung interstitium. In all patients, thin sections showed an increase in the number of peripheral lines (1-2 cm in length) that were diffuse in generalized disease and localized in focal disease. Normal peripheral arcades were not increased in number, but the limbs forming the arcades were thickened in all patients. A diffuse increase in linear and curvilinear structures (reticular pattern) was seen toward the center of the lung. Polygonal structures 1-2 cm in diameter were seen in seven patients with LS but not in healthy subjects. Fissures were thickened in nine patients. Selected 1.5-mm-thick CT sections are recommended through abnormal areas (seen at CT or on chest radiographs) or if these are normal at three levels (midapex, hilus, and 3 cm above the diaphragm) when scanning patients with tumors known to cause LS. 相似文献
65.
Obstetric and nonmalignant gynecologic bleeding: treatment with angiographic embolization 总被引:4,自引:0,他引:4
Eight patients (seven post partum, one post abortion) with massive pelvic hemorrhage related to pregnancy and one patient with uncontrollable bleeding following a cervical biopsy underwent angiography to facilitate the identification and treatment of bleeding sites. In all nine patients pelvic hemorrhage was successfully controlled with embolization under angiographic guidance. Angiographic embolization allowed preservation of the uterus in six patients referred prior to hysterectomy, and one patient subsequently became pregnant. When conservative measures and minor surgical repairs have failed, embolization should be the next step in the treatment of postpartum hemorrhage to avoid major surgery in an unstable patient and to maintain reproductive function. 相似文献
66.
MG Bøe R Salvesen & Å Mygland 《Cephalalgia : an international journal of headache》2009,29(8):855-863
Several studies have shown the benefit of withdrawal therapy when medication overuse headache (MOH) is suspected. Our aim was to compare the effect of withdrawal therapy in patients followed by a neurologist (group A, n = 42) and a primary care physician (PCP) (group B, n = 38). Patients were randomized to A or B, and follow-up was at 3, 6 and 12 months. Calculated mean headache (MH at 6 months + MH at 12 months)/2 (primary end-point) was similar; A 1.04 (0.87, 1.21) and B 1.02 (0.82, 1.21) ( P = 0.87). The number of patients with 50% improvement of headache days was also similar; 14/42 in group A vs. 12/34 in B ( P = 0.86) at 3 months, 15/42 vs. 11/33 ( P = 0.83) at 6 months and 15/42 vs. 14/38 ( P = 0.92) at 12 months. Days without headache during the last 9 months of follow-up were 123 (96, 150) in group A and 137 (112, 161) in B ( P = 0.62). After 3 months one-third were classified as MOH. Patients with MOH improved similarly in group A and B, and so did patients without MOH. Within 1 year 7/42 in A and 9/38 in B had recurrent medication overuse ( P = 0.43). In summary, there were no significant differences in follow-up results between the two groups. 相似文献
67.
68.
Meijer C Wiezer MJ Hack CE Boelens PG Wedel NI Meijer S Nijveldt RJ Statius Muller MG Wiggers T Zoetmulder FA Borel Rinkes IH Cuesta MA Gouma DJ van de Velde CJ Tilanus HW Scotté M Thijs LG van Leeuwen PA 《Shock (Augusta, Ga.)》2001,15(4):261-271
This prospective study investigated the role of reduced hepatic synthesis of regulating proteins in coagulopathy after partial hepatectomy (PH) compared with major abdominal surgery (MAS) without involvement of the liver. Furthermore, we studied the effect of rBPI21, an endotoxin-neutralizing agent, on coagulopathy after PH was studied. Compared with MAS, PH resulted in significantly elevated levels of thrombin-antithrombin-III and plasmin-alpha2-antiplasmin complexes. Levels of antithrombin-3, alpha2-antiplasmin, fibrinogen, plasminogen, alpha2-macroglobulin (alpha2-M), and C1-inhibitor remained lower following PH. Treatment with rBPI21 led to significantly lower levels of tissue-type plasminogen activator (t-PA). Post-operative disseminated intravascular coagulation (DIC) was associated with significantly higher bilirubin and t-PA plasma levels and significantly lower levels of alpha2-M. This study indicates that PH induced hepatic failure results in decreased synthesis of hepatic regulating plasma proteins and subsequent activation of coagulation and fibrinolysis. Prevention of t-PA release by rBPI21 may have important clinical implications. Decreased availability of alpha2-M may be a factor in post-operative DIC. 相似文献
69.
Fatigue, level of everyday physical activity and quality of life after liver transplantation. 总被引:1,自引:0,他引:1
Rita van den Berg-Emons Geert Kazemier Berbke van Ginneken Channah Nieuwenhuijsen Hugo Tilanus Henk Stam 《Journal of rehabilitation medicine》2006,38(2):124-129
OBJECTIVE: To assess whether liver transplant recipients have a hypoactive (sedentary) lifestyle and whether the level of everyday physical activity is related to complaints of fatigue. In addition, we explored the relationship between activity level and health-related quality of life. DESIGN: Case comparison. SUBJECTS: Eight persons 6-36 months after liver transplantation with varying severity of fatigue and 8 persons without known impairments (matched for gender, age, social situation and employment). METHODS: Activity levels were assessed during 2 randomly selected consecutive weekdays with an accelerometry-based Activity Monitor. In the transplantation group, severity of fatigue (Fatigue Severity Scale) and health-related quality of life (RAND-36) were also assessed. RESULTS: Five liver transplant recipients had a hypoactive lifestyle, but there was no significant difference in activity level between the transplantation group and comparison group. Severity of fatigue was correlated (p=0.01) with both duration of dynamic activities and intensity of everyday activity (r(s)=-0.81 and -0.84, respectively). Activity level was correlated (p< or =0.05) with several domains of health-related quality of life (r(s)=0.72-0.78). CONCLUSION: As a group, liver transplant recipients were not significantly less active than comparison subjects. Activity level was related with severity of fatigue and health-related quality of life. These findings have implications for the development of interventions needed to rehabilitate persons after liver transplantation. 相似文献
70.
Reduction in transmission of hepatitis C after the introduction of a heat-treatment step in the production of C1-inhibitor concentrate 总被引:1,自引:0,他引:1
BACKGROUND: The transmission of viral infections via protein concentrates made from a large pool of plasma depends on the selection of donors, fractionation process, and virucidal methods. To date, no data are available on the infectivity risk of plasma concentrates of the inhibitor of the first component of complement (C1-INH). STUDY DESIGN AND METHODS: The prevalence of blood-borne viral infections and levels of transaminases were evaluated in patients treated with a large- pool plasma concentrate of the inhibitor of C1-INH before and after the introduction of virucidal methods. The study included 85 patients with hereditary angioedema and 4 with acquired angioedema. The patients were divided into three groups: 1) 48 untreated patients; 2) 22 patients treated with non-virus-inactivated C1-INH concentrates; and 3) 19 patients treated with virus-inactivated concentrates. Serum samples obtained at various times after the infusion of concentrate were assayed for alanine amino-transferase and tested for hepatitis B surface antigen and antibodies to hepatitis C virus (anti-HCV) and human immunodeficiency virus (anti-HIV); anti-HCV-negative subjects exposed to the concentrate were also tested for HCV RNA. RESULTS: Prevalences of HCV infection and elevated alanine aminotransferase are significantly lower in patients treated with virus-inactivated concentrates than in those exposed to non-virus-inactivated concentrates. No patients were anti-HIV positive. CONCLUSION: This study suggests that C1-INH concentrates transmitted HCV, but that the virucidal methods adopted are effective in reducing the infectivity. 相似文献