全文获取类型
收费全文 | 1157篇 |
免费 | 188篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 14篇 |
妇产科学 | 10篇 |
基础医学 | 308篇 |
口腔科学 | 3篇 |
临床医学 | 166篇 |
内科学 | 229篇 |
皮肤病学 | 1篇 |
神经病学 | 35篇 |
特种医学 | 10篇 |
外科学 | 92篇 |
综合类 | 9篇 |
预防医学 | 130篇 |
药学 | 173篇 |
中国医学 | 1篇 |
肿瘤学 | 161篇 |
出版年
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 22篇 |
2017年 | 17篇 |
2016年 | 12篇 |
2015年 | 21篇 |
2014年 | 32篇 |
2013年 | 27篇 |
2012年 | 49篇 |
2011年 | 48篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 49篇 |
2007年 | 70篇 |
2006年 | 58篇 |
2005年 | 67篇 |
2004年 | 64篇 |
2003年 | 70篇 |
2002年 | 72篇 |
2001年 | 65篇 |
2000年 | 57篇 |
1999年 | 68篇 |
1998年 | 17篇 |
1997年 | 14篇 |
1996年 | 19篇 |
1995年 | 18篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 24篇 |
1991年 | 39篇 |
1990年 | 39篇 |
1989年 | 32篇 |
1988年 | 12篇 |
1987年 | 16篇 |
1986年 | 19篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有1345条查询结果,搜索用时 15 毫秒
71.
Nielsen M Franken PF Reinards TH Weiss MM Wagner A van der Klift H Kloosterman S Houwing-Duistermaat JJ Aalfs CM Ausems MG Bröcker-Vriends AH Gomez Garcia EB Hoogerbrugge N Menko FH Sijmons RH Verhoef S Kuipers EJ Morreau H Breuning MH Tops CM Wijnen JT Vasen HF Fodde R Hes FJ 《Journal of medical genetics》2005,42(9):e54
Objective: To investigate the contribution of MYH associated polyposis coli (MAP) among polyposis families in the Netherlands, and the prevalence of colonic and extracolonic manifestations in MAP patients. Methods: 170 patients with polyposis coli, who previously tested negative for APC mutations, were screened by denaturing gradient gel electrophoresis and direct sequencing to identify MYH germline mutations. Results: Homozygous and compound heterozygous MYH mutations were identified in 40 patients (24%). No difference was found in the percentage of biallelic mutation carriers between patients with 10–99 polyps or 100–1000 polyps (29% in both groups). Colorectal cancer was found in 26 of the 40 patients with MAP (65%) within the age range 21 to 67 years (median 45). Complete endoscopic reports were available for 16 MAP patients and revealed five cases with gastro-duodenal polyps (31%), one of whom also presented with a duodenal carcinoma. Breast cancer occurred in 18% of female MAP patients, significantly more than expected from national statistics (standardised morbidity ratio = 3.75). Conclusions: Polyp numbers in MAP patients were equally associated with the attenuated and classical polyposis coli phenotypes. Two thirds of the MAP patients had colorectal cancer, 95% of whom were older than 35 years, and one third of a subset of patients had upper gastrointestinal lesions. Endoscopic screening of the whole intestine should be carried out every two years for all MAP patients, starting from age 25–30 years. The frequent occurrence of additional extraintestinal manifestations, such as breast cancer among female MAP patients, should be thoroughly investigated. 相似文献
72.
Ayez N Lalmahomed ZS Eggermont AM Ijzermans JN de Jonge J van Montfort K Verhoef C 《Annals of surgical oncology》2012,19(5):1618-1627
Background
Data from patients with colorectal liver metastases (CRLM) who received neoadjuvant chemotherapy before resection were reviewed and evaluated to see whether neoadjuvant chemotherapy influences the predictive outcome of R1 resections (margin is 0 mm) in patients with CRLM. 相似文献73.
Malignant pancreatic tumour within the spectrum of tuberous sclerosis complex in childhood 总被引:1,自引:0,他引:1
Verhoef S van Diemen-Steenvoorde R Akkersdijk WL Bax NM Ariyurek Y Hermans CJ van Nieuwenhuizen O Nikkels PG Lindhout D Halley DJ Lips K van den Ouweland AM 《European journal of pediatrics》1999,158(4):284-287
A 12-year-old boy with tuberous sclerosis complex (TSC) presented with a large retroperitoneal tumour. Exploratory surgery
revealed an infiltrative tumour originating from the pancreas, with local metastases to the lymph nodes. The histologal diagnosis
was a malignant islet cell tumour. Retrospectively measured pancreatic hormone levels, however, were normal. A connection
between the malignancy and TSC was demonstrated by loss of heterozygosity of the TSC2 gene in the tumour. The primary mutation
Q478X in this patient was identified in exon 13 of the TSC2 gene on chromosome 16.
Conclusion Pancreatic islet cell tumours have been mainly associated with multiple endocrine neoplasia syndrome type 1. In our case we
demonstrate a direct relationship of this tumour to tuberous sclerosis complex, in the absence of further signs of multiple
endocrine neoplasia syndrome type 1.
Received: 17 February 1998 / Accepted in revised form: 8 July 1998 相似文献
74.
Aulo Gelli Anissa Collishaw Josue Awonon Elodie Becquey Ampa Diatta Loty Diop Rasmane Ganaba Derek Headey Alain Hien Francis Ngure Abdoulaye Pedehombga Marco Santacroce Laeticia C. Toe Hans Verhoef Harold Alderman Marie T. Ruel 《Maternal & child nutrition》2023,19(4):e13528
Nutrition-sensitive agriculture programmes have the potential to improve child nutrition outcomes, but livestock intensification may pose risks related to water, sanitation and hygiene (WASH) conditions. We assessed the impact of SELEVER, a nutrition- and gender-sensitive poultry intervention, with and without added WASH focus, on hygiene practices, morbidity and anthropometric indices of nutrition in children aged 2−4 years in Burkina Faso. A 3-year cluster randomised controlled trial was implemented in 120 villages in 60 communes (districts) supported by the SELEVER project. Communes were randomly assigned using restricted randomisation to one of three groups: (1) SELEVER intervention (n = 446 households); (2) SELEVER plus WASH intervention (n = 432 households); and (3) control without intervention (n = 899 households). The study population included women aged 15−49 years with an index child aged 2−4 years. We assessed the effects 1.5-years (WASH substudy) and 3-years (endline) post-intervention on child morbidity and child anthropometry secondary trial outcomes using mixed effects regression models. Participation in intervention activities was low in the SELEVER groups, ranging from 25% at 1.5 years and 10% at endline. At endline, households in the SELEVER groups had higher caregiver knowledge of WASH-livestock risks (∆ = 0.10, 95% confidence interval [CI] [0.04−0.16]) and were more likely to keep children separated from poultry (∆ = 0.09, 95% CI [0.03−0.15]) than in the control group. No differences were found for other hygiene practices, child morbidity symptoms or anthropometry indicators. Integrating livestock WASH interventions alongside poultry and nutrition interventions can increase knowledge of livestock-related risks and improve livestock-hygiene-related practices, yet may not be sufficient to improve the morbidity and nutritional status of young children. 相似文献
75.
Gous A Lipman J Scribante J Tshukutsoane S Hon H Pinder M Mathivha R Verhoef L Stass H 《International journal of antimicrobial agents》2005,26(1):50-55
This study aimed to investigate whether fluid shifts alter ciprofloxacin pharmacokinetics in critically ill patients over time. Patients > or = 18 years, with normal renal function, requiring intensive care treatment and parenteral antibiotics were enrolled. Group A (22 patients) included patients with documented intra-abdominal infections. Group B (18 patients) included patients with severe sepsis from other causes. All patients received intravenous ciprofloxacin 400 mg every 8 h infused over 60 min. Eight timed blood specimens were taken on days 0, 2 and 7. Ciprofloxacin plasma concentrations were determined using high performance liquid chromatography. There were no significant differences between the pharmacokinetics of the two groups or over time. Ciprofloxacin pharmacokinetics in critically ill patients do not change over time, and intra-abdominal sepsis does not alter ciprofloxacin pharmacokinetic parameters to a greater degree than sepsis from other causes in critically ill patients. 相似文献
76.
In vitro evaluation of intestinal absorption of desmopressin using drug-delivery systems based on superporous hydrogels 总被引:6,自引:0,他引:6
Polnok A Verhoef JC Borchard G Sarisuta N Junginger HE 《International journal of pharmaceutics》2004,269(2):303-310
The aim of this study was to investigate and modify the potential of drug-delivery systems based on superporous hydrogel (SPH) for improving the intestinal transport of the peptide drug desmopressin in vitro. The swelling properties and mechanical strength of SPHs were studied. The release profile of desmopressin was investigated by changing the composition of excipients in the formulations. Subsequently, the ability of the SPH-based drug-delivery systems to enhance the transport of desmopressin across porcine intestine was performed in vitro. The swelling properties and mechanical strength of SPHs were affected by the addition of the disintregrant AcDiSol. This disintregrant reduced the swelling ratio to 10% and the time to 80% swelling was retarded by 3-5 min in comparison to the negative control. AcDiSol increased the mechanical strength, according to the increasing of penetration pressure value, the pressure that the punch can penetrate the gel, of the SPHs. The transport of desmopressin across the intestinal mucosa in vitro was enhanced four- and six-fold by applying SPH, with AcDiSol, in the absence and presence of the additional absorption enhancer trimethyl chitosan chloride, respectively, in comparison to the negative control. It is concluded that drug-delivery systems based on SPHs are promising for enhancing the intestinal absorption of desmopressin. 相似文献
77.
Evaluation of genetic determinants involved in beta-lactam- and multiresistance in a surgical ICU 总被引:2,自引:0,他引:2
van Loon HJ Box AT Verhoef J Fluit AC 《International journal of antimicrobial agents》2004,24(2):130-134
Antibiotic resistance is a major and well-known problem in intensive care units (ICUs) world-wide and previously susceptible isolates become resistant through the acquisition of resistance determinants from other bacteria or the development of mutations, as is the case in beta-lactam resistance. We evaluated the presence of resistance determinants involved in beta-lactam resistance and multi-resistance in order to establish the contribution of horizontal gene transfer to the spread of resistance in a surgical ICU during an antibiotic rotation study. Pseudomonas aeruginosa and Enterobacteriaceae isolates were selected and iso-electric focusing (IEF), DNA-typing methods such as specific beta-lactamase and specific integron PCRs were performed to determine the presence of beta-lactamases. The PCRs specific for IMP-1, OXA-1, and VIM-type beta-lactamases performed on the selected P. aeruginosa and Enterobacteriaceae isolates with MICs for cephalosporins >1 mg/l did not demonstrate any of these beta-lactamases. IEF for 14 pseudomonads, representing 7 genotypes from 9 patients, showed a beta-lactamase with a pI larger than 8.5 in 13 of the isolates. The integrase PCR was positive for only five isolates from three patients and conserved segment PCR showed integrons of variable sizes (700, 900, 1,400 and 1,500 bp). Each patient had its own integron types. It can be concluded that integrons and associated resistance determinants played only a minor role in the surgical ICU and beta-lactam resistance among P. aeruginosa isolates was most likely due to the derepression of its AmpC gene. 相似文献
78.
Mascha P van den Berg J Coos Verhoef Stefan G Romeijn Frans W H M Merkus 《European journal of pharmaceutics and biopharmaceutics》2004,58(1):131-135
The uptake of estradiol and progesterone into the cerebrospinal fluid (CSF) after intranasal and intravenous administration in rats was investigated. Each animal received estradiol intranasally (40 microg/rat) and by intravenous infusion (10 microg/rat) into the jugular vein using a vascular access port. Hereafter, the same set of rats was treated with progesterone intranasally (200 microg/rat) and by intravenous infusion (104 microg/rat). Following nasal delivery, both steroid hormones reach Cmax values in plasma and CSF at 15 min after administration. Intravenous infusion of estradiol and progesterone shows comparable plasma and CSF concentration-time profiles compared to the nasal route. For both hormones the AUCCSF/AUCplasma ratios (mean +/- SD) after intranasal delivery (estradiol 2.3 +/- 1.1%; progesterone 1.9 +/- 0.7%) do not differ significantly from the ratios shown after intravenous infusion (estradiol 2.0 +/- 0.6%; progesterone 2.2 +/- 0.8%). These results indicate that after nasal delivery estradiol and progesterone are rapidly absorbed into the systemic circulation, from where the non-protein bound hormones probably enter the CSF by crossing the blood-brain barrier. No extra direct nose-CSF transport could be demonstrated. 相似文献
79.
Marja J Verhoef Andrea Mulkins Ania Kania Barbara Findlay-Reece Silvano Mior 《BMC health services research》2010,10(1):14
Background
Integrative health care (IHC) is an interdisciplinary blending of conventional medicine and complementary and alternative medicine (CAM) with the purpose of enhancing patients' health. In 2006, we designed a study to assess outcomes that are relevant to people using such care. However, we faced major challenges in conducting this study and hypothesized that this might be due to the lack of a research climate in these clinics. To investigate these challenges, we initiated a further study in 2008, to explore the reasons why IHC clinics are not conducting outcomes research and to identify strategies for conducting successful in-house outcomes research programs. The results of the latter study are reported here. 相似文献80.
Assessing potential introduction of universal or targeted hepatitis A vaccination in the Netherlands
Suijkerbuijk AW Lugnér AK van Pelt W Wallinga J Verhoef LP de Melker HE de Wit GA 《Vaccine》2012,30(35):5199-5205
In many industrialized countries, hepatitis A incidence rates have declined steadily in the past decades. Since future cohorts of non-vaccinated elderly will lack protection against disease and the burden of hepatitis A is higher with increasing age, this could be an argument in favour of taking preventive measures such as including hepatitis A vaccine into the National Immunisation Program, or offering hepatitis A vaccine to the elderly only. Using a vaccination evaluation scheme, we assessed the potential benefits and drawbacks of introducing hepatitis A vaccine in the National Immunisation Program in the Netherlands. The average number of annual hepatitis A notifications is declining, from 957 in the period 1991 to 1995 to 211 over the period 2006 to 2010. The direct health care costs and costs due to productivity losses per patient are rising, because the age at infection increases and older patients require a relatively higher number of hospitalizations. Initiating a vaccination program would most likely not be cost-effective yet. The annual costs of mass-vaccination are large: about €10 million for infants and €13 million for older people (and only in the first year €210 million), based on current retail prices. The annual effects of mass-vaccination are small: the cost-of-illness in recent years attributed to hepatitis A infection is estimated to be €650,000 per year, and the disease burden is on average 17 DALYs. Given the current low hepatitis A incidence, and the continuing decline in incidence, targeted preventive measures such as vaccinating travellers and other high-risk groups and timely vaccination of close contacts of hepatitis A patients are adequate. However, because susceptibility to hepatitis A is increasing in the group with the highest risk of developing severe complications upon infections, careful monitoring of the epidemiology of hepatitis A remains important. 相似文献