全文获取类型
收费全文 | 1022篇 |
免费 | 37篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 36篇 |
妇产科学 | 16篇 |
基础医学 | 82篇 |
口腔科学 | 11篇 |
临床医学 | 45篇 |
内科学 | 254篇 |
皮肤病学 | 10篇 |
神经病学 | 36篇 |
特种医学 | 102篇 |
外科学 | 222篇 |
综合类 | 46篇 |
预防医学 | 83篇 |
眼科学 | 6篇 |
药学 | 28篇 |
肿瘤学 | 84篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 18篇 |
2014年 | 30篇 |
2013年 | 43篇 |
2012年 | 36篇 |
2011年 | 45篇 |
2010年 | 44篇 |
2009年 | 42篇 |
2008年 | 30篇 |
2007年 | 47篇 |
2006年 | 60篇 |
2005年 | 43篇 |
2004年 | 66篇 |
2003年 | 34篇 |
2002年 | 33篇 |
2001年 | 32篇 |
2000年 | 34篇 |
1999年 | 25篇 |
1998年 | 33篇 |
1997年 | 26篇 |
1996年 | 27篇 |
1995年 | 36篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 11篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 22篇 |
1988年 | 22篇 |
1987年 | 13篇 |
1986年 | 18篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1974年 | 2篇 |
1970年 | 3篇 |
1958年 | 2篇 |
1956年 | 1篇 |
排序方式: 共有1067条查询结果,搜索用时 0 毫秒
101.
G. M. E. E. Peeters N. M. van Schoor S. M. F. Pluijm D. J. H. Deeg P. Lips 《Osteoporosis international》2010,21(7):1189-1195
Summary
This study tests whether the relationship between physical activity and (recurrent) falling is U-shaped. Among 1,337 community-dwelling older persons, no evidence for a nonlinear association was found. If all older persons increase their physical activity level with 100 units, 4% may be prevented to become recurrent fallers. 相似文献102.
With advancement in laparoscopic surgery a number of surgical procedures can be performed combined with laparoscopic cholecystectomy
in a single surgery. We evaluate the safety & efficacy of such surgeries. A retrospective review of all patients who had undergone
combined procedures with laparoscopic cholecystectomy during January 2005 to June 2009 was performed. 3144 laparoscopic cholecystectomies
were performed in the period from January 2005 to June 2009. Of these, 401 cases were combined with another procedure. The
mean operative time was 80 min (range 50–270 min). The mean hospital stay was 3.2 days (range 1–5 days). The mean no. of days
injectable analgesics was required was 2 days (range 1 day–4 days). Combined procedures provide patients with all the benefits
of minimal invasive surgery and also give the benefit of single time anaesthesia without adding to post operative morbidity
& hospital stay. 相似文献
103.
Fenella KS Welsh Paris P Tekkis Timothy G John Myrddin Rees 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2010,12(3):188-194
Background:
There is no prospective randomized data comparing laparoscopic to open hepatectomy. This study compared short- and long-term outcomes in patients undergoing hepatectomy for colorectal metastases (CRM), who were suitable for either laparoscopic or open surgery.Methods:
Data were prospectively collected from consecutive patients undergoing hepatic resection of CRM at a single centre (1987–2007). Patients who were suitable for laparoscopic resection (Group 1) were compared with patients whose tumour characteristics would best be considered for open resection (Group 2).Results:
Out of 1152 hepatectomies, 266 (23.1%) were deemed suitable for a laparoscopic approach. The median (IQR) number of metastases was greater in Group 2 [2(1–20) vs. 1(1–10), P < 0.001], as was the mean (SD) tumour size [5.3(3.6) cm vs. 3.3(1.2) cm, P < 0.001]. The median (IQR) operation time [210 (70) min vs. 240 (90) min, P < 0.001] and blood loss [270 (265) ml vs. 355 (320) ml, P < 0.001] were less in Group 1. There was no difference in length of stay, morbidity or mortality. Patients in Group 2 had a higher R1 resection rate (14.9%) compared with Group 1 (4.5%, P < 0.001) and lower 5-year survival (37.8% vs. 44.2%, P= 0.005).Discussion:
Current criteria for laparoscopic hepatectomy selects patients who have more straight-forward surgery, with less risk of an involved resection margin and better long-term survival, compared with patients unsuited to a laparoscopic approach. Clearly defined criteria for laparoscopic hepatectomy are essential to allow meaningful analysis of outcomes and the results of unrandomized series of laparoscopic hepatectomies must be interpreted with caution. 相似文献104.
OBJECTIVE
To evaluate the change in quality of life (QoL) 3 years after high‐dose intensity‐modulated radiotherapy (IMRT) using gold fiducial marker‐based position verification in patients with locally advanced prostate cancer.PATIENTS AND METHODS
Between October 2003 and November 2004, 95 patients with locally advanced prostate cancer were treated with 76 Gy IMRT with gold‐fiducial marker‐based position verification. Before treatment (baseline) and 1, 6 and 36 months after RT the QoL was measured using the RAND‐36, the European Organization for Research and Treatment of Cancer (EORTC) core questionnaire (QLQ‐C30(+3)) and the prostate tumour‐specific module (EORTC QLQ‐PR25). Changes in QoL with time of ≥10 points were considered clinically relevant.RESULTS
After 3 years there was a statistically significant improvement in QoL for emotional role restriction and functioning, change in health, mental health and insomnia, compared with baseline. Emotional role restriction increased by >10 points and was therefore clinically relevant, while all other differences were of <10 points. There was a statistically significant deterioration of QoL after 3 years in physical and cognitive functioning, bowel symptoms/function and sexual activity. Only the sexual activity QoL score changed by 12 points and was therefore the only meaningful deterioration in QoL at 3 years after treatment.CONCLUSION
IMRT and accurate position verification provide the possibility to deliver a high irradiation dose to the prostate without clinically relevant deterioration in long‐term QoL, except for a persistent decrease in sexual activity score. 相似文献105.
Petra J Buizert Natasja M van Schoor Paul Lips Dorly JH Deeg Elisabeth M Eekhoff 《Journal of bone and mineral research》2009,24(6):1103-1109
Epidemiological observations support a positive relationship between cardiovascular diseases (CVD) and osteoporosis, where cholesterol has been indicated to be a possible link. Only a few studies have investigated the relation between lipids and BMD, but the association remains unclear. We studied the relationship between serum lipids and BMD of the calcaneus. A cross‐sectional population‐based study was performed, based on data from the Longitudinal Aging Study Amsterdam, including 620 men and 635 women, 65–88 yr of age. BMD was measured by quantitative ultrasound (QUS), velocity of sound (VOS; m/s), and broadband ultrasound attenuation (BUA; dB/MHz). Models were adjusted for age, body mass index, physical activity, smoking, alcohol, diabetes mellitus, hypertension, testosterone, and 25‐hydroxyvitamin D. No association was found between total cholesterol (TC) and QUS. Men and women in the highest quartile of high‐density lipoprotein cholesterol (HDL‐c) had a significantly lower QUS (men—VOS: β = ?20.8, p = 0.00; BUA: β = ?5.2, p = 0.02; women—VOS: β = ?18.6, p = 0.00) compared with men and women in the lowest quartile. An even stronger positive association was seen between TC/HDL‐c ratio and QUS (men—VOS: β = 21.8, p = 0.00; BUA: β = 5.5, p = 0.01; women—VOS: β = 19.2, p = 0.00; BUA: β = 3.6, p = 0.05). Our analysis shows that the lipid profile that is favorable in the prevention of CVD (i.e., high levels of HDL‐c and low TC/HDL‐c ratio) is unfavorable for QUS. These results indicate that HDL‐c levels do not explain the association between osteoporosis and CVD. 相似文献
106.
SM Vieira HP Lemos R Grespan MH Napimoga D Dal-Secco A Freitas TM Cunha WA Verri Jr DA Souza-Junior MC Jamur KS Fernandes C Oliver JS Silva MM Teixeira FQ Cunha 《British journal of pharmacology》2009,158(3):779-789
Background and purpose:
Chemokines orchestrate neutrophil recruitment to inflammatory foci. In the present study, we evaluated the participation of three chemokines, KC/CXCL1, MIP-2/CXCL2 and LIX/CXCL5, which are ligands for chemokine receptor 2 (CXCR2), in mediating neutrophil recruitment in immune inflammation induced by antigen in immunized mice.Experimental approach:
Neutrophil recruitment was assessed in immunized mice challenged with methylated bovine serum albumin, KC/CXCL1, LIX/CXCL5 or tumour necrosis factor (TNF)-α. Cytokine and chemokine levels were determined in peritoneal exudates and in supernatants of macrophages and mast cells by elisa. CXCR2 and intercellular adhesion molecule 1 (ICAM-1) expression was determined using immunohistochemistry and confocal microscopy.Key results:
Antigen challenge induced dose- and time-dependent neutrophil recruitment and production of KC/CXCL1, LIX/CXCL5 and TNF-α, but not MIP-2/CXCL2, in peritoneal exudates. Neutrophil recruitment was inhibited by treatment with reparixin (CXCR1/2 antagonist), anti-KC/CXCL1, anti-LIX/CXCL5 or anti-TNF-α antibodies and in tumour necrosis factor receptor 1-deficient mice. Intraperitoneal injection of KC/CXCL1 and LIX/CXCL5 induced dose- and time-dependent neutrophil recruitment and TNF-α production, which were inhibited by reparixin or anti-TNF-α treatment. Macrophages and mast cells expressed CXCR2 receptors. Increased macrophage numbers enhanced, while cromolyn sodium (mast cell stabilizer) diminished, LIX/CXCL5-induced neutrophil recruitment. Macrophages and mast cells from immunized mice produced TNF-α upon LIX/CXCL5 stimulation. Methylated bovine serum albumin induced expression of ICAM-1 on mesenteric vascular endothelium, which was inhibited by anti-TNF-α or anti-LIX/CXCL5.Conclusion and implications:
Following antigen challenge, CXCR2 ligands are produced and act on macrophages and mast cells triggering the production of TNF-α, which synergistically contribute to neutrophil recruitment through induction of the expression of ICAM-1. 相似文献107.
Wicherts IS van Schoor NM Boeke AJ Visser M Deeg DJ Smit J Knol DL Lips P 《The Journal of clinical endocrinology and metabolism》2007,92(6):2058-2065
CONTEXT: Vitamin D deficiency is common among older people and can cause mineralization defects, bone loss, and muscle weakness. OBJECTIVE: The aim of this study was to investigate the association of serum 25-hydroxyvitamin D (25-OHD) concentration with current physical performance and its decline over 3 yr among elderly. DESIGN: The study consisted of a cross-sectional and longitudinal design (3-yr follow-up) within the Longitudinal Aging Study Amsterdam. SETTING: An age- and sex-stratified random sample of the Dutch older population was used. OTHER PARTICIPANTS: Subjects included 1234 men and women (aged 65 yr and older) for cross-sectional analysis and 979 (79%) persons for longitudinal analysis. MAIN OUTCOME MEASURE(S): Physical performance (sum score of the walking test, chair stands, and tandem stand) and decline in physical performance were measured. RESULTS: Serum 25-OHD was associated with physical performance after adjustment for age, gender, chronic diseases, degree of urbanization, body mass index, and alcohol consumption. Compared with individuals with serum 25-OHD levels above 30 ng/ml, physical performance was poorer in participants with serum 25-OHD less than 10 ng/ml [regression coefficient (B) = -1.69; 95% confidence interval (CI) = -2.28; -1.10], and with serum 25-OHD of 10-20 ng/ml (B = -0.46; 95% CI = -0.90; -0.03). After adjustment for confounding variables, participants with 25-OHD less than 10 ng/ml and 25-OHD between 10 and 20 ng/ml had significantly higher odds ratios (OR) for 3-yr decline in physical performance (OR = 2.21; 95% CI = 1.00-4.87; and OR = 2.01; 95% CI = 1.06-3.81), compared with participants with 25-OHD of at least 30 ng/ml. The results were consistent for each individual performance test. CONCLUSIONS: Serum 25-OHD concentrations below 20 ng/ml are associated with poorer physical performance and a greater decline in physical performance in older men and women. Because almost 50% of the population had serum 25-OHD below 20 ng/ml, public health strategies should be aimed at this group. 相似文献
108.
Koebrugge B Vogelaar FJ Lips DJ Pruijt JF van der Linden JC Ernst MF Bosscha K 《European journal of surgical oncology》2011,37(11):964-970
Background
A subgroup of stage II colonic cancer patients are considered to be at high-risk for recurrent/metastatic disease based on 1) tumour obstruction/perforation 2) <10 lymph nodes 3) T4 lesions and 4) lymphangio-invasion. Their prognosis is regarded as comparable to stage III (T1-4N+M0) colonic cancer and it is therefore strongly advised to treat them with adjuvant chemotherapy. The purpose of this study was i) to determine the magnitude of prognostic significance of the conventional high-risk factors and ii) to determine whether the number of high-risk factors influences outcome.Methods
We retrospectively analyzed 212 stage II colonic cancer patients undergoing surgery between January 2002 and December 2008. No adjuvant chemotherapy was given. Survival analyses were performed.Results
154/212 (73%) patients were considered to be high-risk patients based on conventional high-risk factors. 58 patients did not meet any high-risk factor, 125 patients met 1 high-risk factor and 29 patients met ≥2 high-risk factors. Median follow up was 40 months.Multivariate analysis identified four independent risk factors for recurrent/metastatic disease: age, obstruction, perforation and lymphangio-invasion.The three-year-DFS-rates for the low-risk group, the high-risk group with 1 high-risk factor and the high-risk group with ≥2 high-risk criteria are 90.4%, 87.6% and 75.9% respectively.Patients meeting ≥2 conventional high-risk criteria had a significantly worse three-year disease free survival (p < 0.002).Conclusions
Four independent high-risk factors were identified. The number of high-risk factors does influence outcome. More attention should be given to the definition and treatment of high-risk stage II colonic cancer patients. 相似文献109.
110.
Lips I Dehnad H Kruger AB van Moorselaar J van der Heide U Battermann J van Vulpen M 《International journal of radiation oncology, biology, physics》2007,69(3):656-661
PURPOSE: To compare quality of life (QoL) after 70 Gy conformal radiotherapy with QoL after 76 Gy intensity-modulated radiotherapy (IMRT) in patients with locally advanced prostate carcinoma. METHODS AND MATERIALS: Seventy-eight patients with locally advanced prostate cancer were treated with 70 Gy three-field conformal radiotherapy, and 92 patients received 76 Gy IMRT with fiducial markers for position verification. Quality of life was measured by RAND-36, the European Organization for Research and Treatment of Cancer core questionnaire (EORTC QLQ-C30(+3)), and the prostate-specific EORTC QLQ-PR25, before radiotherapy (baseline) and 1 month and 6 months after treatment. Quality of life changes in time (baseline vs. 1 month and baseline vs. 6 months) of > or =10 points were considered clinically relevant. RESULTS: Differences between the treatment groups for QoL changes over time occurred in several QoL domains. The 76-Gy group revealed no significant deterioration in QoL compared with the 70-Gy group. The IMRT 76-Gy group even demonstrated a significantly better change in QoL from baseline to 1 month in several domains. The conformal 70-Gy group revealed temporary deterioration in pain, role functioning, and urinary symptoms; for the IMRT 76-Gy group a better QoL in terms of change in health existed after 1 month, which persisted after 6 months. For both treatment groups temporary deterioration in physical role restriction occurred after 1 month, and an improvement in emotional role restriction occurred after 6 months. Sexual activity was reduced after treatment for both groups and remained decreased after 6 months. CONCLUSIONS: Intensity-modulated radiotherapy and accurate position verification seem to provide a possibility to increase the radiation dose for prostate cancer without deterioration in QoL. 相似文献