全文获取类型
收费全文 | 1290篇 |
免费 | 75篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 15篇 |
妇产科学 | 33篇 |
基础医学 | 139篇 |
口腔科学 | 12篇 |
临床医学 | 115篇 |
内科学 | 305篇 |
皮肤病学 | 11篇 |
神经病学 | 61篇 |
特种医学 | 23篇 |
外科学 | 300篇 |
综合类 | 12篇 |
一般理论 | 1篇 |
预防医学 | 63篇 |
眼科学 | 100篇 |
药学 | 80篇 |
中国医学 | 6篇 |
肿瘤学 | 106篇 |
出版年
2023年 | 3篇 |
2022年 | 19篇 |
2021年 | 25篇 |
2020年 | 29篇 |
2019年 | 26篇 |
2018年 | 30篇 |
2017年 | 24篇 |
2016年 | 23篇 |
2015年 | 24篇 |
2014年 | 49篇 |
2013年 | 47篇 |
2012年 | 77篇 |
2011年 | 91篇 |
2010年 | 55篇 |
2009年 | 49篇 |
2008年 | 103篇 |
2007年 | 107篇 |
2006年 | 80篇 |
2005年 | 88篇 |
2004年 | 80篇 |
2003年 | 62篇 |
2002年 | 76篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 17篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 4篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 11篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1383条查询结果,搜索用时 15 毫秒
21.
22.
Amy E. Wagenaar Jun Tashiro Juan E. Sola Obi Ekwenna Akin Tekin Eduardo A. Perez 《Pediatric surgery international》2016,32(5):439-449
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.23.
Shimizu Daisuke Miyazaki Dai Ehara Fumie Shimizu Yumiko Uotani Ryu Inata Koudai Sasaki Shin-ichi Inoue Yoshitsugu 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(1):157-166
Graefe's Archive for Clinical and Experimental Ophthalmology - To evaluate the efficacy of real-time PCR for 16S ribosomal DNA (16S r-DNA) and sequencing for diagnosing microbial keratitis. We... 相似文献
24.
Akihiro Shimomura Isao Matsui Takayuki Hamano Takuya Ishimoto Yumiko Katou Kenji Takehana Kazunori Inoue Yasuo Kusunoki Daisuke Mori Chikako Nakano Yoshitsugu Obi Naohiko Fujii Yoshitsugu Takabatake Takayoshi Nakano Yoshiharu Tsubakihara Yoshitaka Isaka Hiromi Rakugi 《Journal of the American Society of Nephrology : JASN》2014,25(9):1954-1965
Vascular calcification (VC) is a life-threatening complication of CKD. Severe protein restriction causes a shortage of essential amino acids, and exacerbates VC in rats. Therefore, we investigated the effects of dietary l-lysine, the first-limiting amino acid of cereal grains, on VC. Male Sprague-Dawley rats at age 13 weeks were divided randomly into four groups: low-protein (LP) diet (group LP), LP diet+adenine (group Ade), LP diet+adenine+glycine (group Gly) as a control amino acid group, and LP diet+adenine+l-lysine·HCl (group Lys). At age 18 weeks, group LP had no VC, whereas groups Ade and Gly had comparable levels of severe VC. l-Lysine supplementation almost completely ameliorated VC. Physical parameters and serum creatinine, urea nitrogen, and phosphate did not differ among groups Ade, Gly, and Lys. Notably, serum calcium in group Lys was slightly but significantly higher than in groups Ade and Gly. Dietary l-lysine strongly suppressed plasma intact parathyroid hormone in adenine rats and supported a proper bone-vascular axis. The conserved orientation of the femoral apatite in group Lys also evidenced the bone-protective effects of l-lysine. Dietary l-lysine elevated plasma alanine, proline, arginine, and homoarginine but not lysine. Analyses in vitro demonstrated that alanine and proline inhibit apoptosis of cultured vascular smooth muscle cells, and that arginine and homoarginine attenuate mineral precipitations in a supersaturated calcium/phosphate solution. In conclusion, dietary supplementation of l-lysine ameliorated VC by modifying key pathways that exacerbate VC.Medial vascular calcification is common in aging, diabetes, and CKD.1–4 Because the presence of vascular calcification is strongly associated with increased cardiovascular morbidity and mortality, several studies in both animals and humans have sought ways to reduce the extent of vascular calcification.5–10 However, satisfactory therapies have not yet been established.11Adenine-induced renal failure is one of the commonly used animal models for studying the development of vascular calcification, but the prevalence of vascular calcification in this model is not very high. Indeed, Price et al. reported that vascular calcification was detected in only 30% of rats with adenine-induced chronic renal failure (adenine rats) fed a normal-protein diet.5 These authors speculated that consistent vascular calcification might require a longer period of adenine feeding. On the basis of this idea, they designed a low-protein (LP) diet in an attempt to reduce the nitrogen load and thus enable the rats to thrive on the adenine diet for longer periods. As a result of this attempt, Price et al. unexpectedly found that adenine rats fed a LP diet had extensive vascular calcification without a longer feeding period.5 All 13 adenine rats fed the LP diet had uniform alizarin red staining of the aorta, whereas only 3 of the 11 adenine rats fed a normal-protein diet had partial calcification.5 These findings indicated that dietary protein deficiency correlates with the extent of vascular calcification.Proteins are usually made from 20 kinds of amino acids. On the basis of nutritional requirements, these amino acids can be divided into two groups: essential amino acids (EAAs) and non-EAAs. Because restriction of dietary protein results in a shortage of EAAs, the level of dietary EAAs may be relevant to the extent of vascular calcification. Among nine EAAs, this study focused on l-lysine (l-Lys) based on the following three reasons. First, l-Lys is the first-limiting amino acid in most cereal grains.12 Second, the safety of l-Lys supplementation has been verified in the area of animal husbandry. l-Lys has long been added to feed grains in order to improve the utility of feed proteins.13 Third, several studies have demonstrated that dietary supplementation with l-Lys protects bones from osteoporosis, a pathologic condition that often coexists with vascular calcification.14,15 These points prompted us to hypothesize that supplementation with l-Lys would ameliorate vascular calcification. Therefore, in this study, we tested this hypothesis using adenine rats. 相似文献
25.
Takashi Mitsuki Muneyoshi Kimura Hideki Araoka Kosei Kageyama Shinsuke Takagi Go Yamamoto Shigeki Nakamura Yoshitsugu Miyazaki Naoyuki Uchida Akiko Yoneyama Shuichi Taniguchi 《Journal of infection and chemotherapy》2019,25(4):289-292
Few cases of cryptococcal infection following umbilical cord blood transplantation (UCBT) have been reported. We report a case, where cryptococcal infection occurred soon after rapidly reducing the dose of tacrolimus in a UCBT recipient who received micafungin prophylaxis during the early phase of transplantation. The etiology of cryptococcal infection following allogeneic hematopoietic stem cell transplantation (allo-HSCT), including UCBT, might be associated with rapid dose-reduction of calcineurin inhibitors, such as tacrolimus during early phase of allo-HSCT. To our knowledge, this is the first English-language report to describe in detail a case of cryptococcal meningitis with fungemia during early phase of UCBT. 相似文献
26.
Fukushima S Tanaka T Sato T Shirakawa Y Asayama K Shirahata A 《Seminars in thrombosis and hemostasis》2002,28(6):539-544
A recently developed method to quantitate prothrombin in plasma uses the carinactivase-1 (CA-1) method. The present study was designed to establish the reference value by the CA-1 method in the neonatal period and to explore the effect of gestational age, birth weight, concurrent diseases, and vitamin K administration on the prothrombin levels. We enrolled 78 consecutive neonates. The gestational ages ranged from 28 to 41 weeks, and the birth weight ranged from 850 to 3750 g. Twenty-nine infants had concurrent diseases, and the others (n = 49) were healthy. A 300 microL blood sample was drawn into a plastic syringe containing 60 U freeze-dried buffered heparin. Prothrombin levels did not differ between appropriate-for-date (AFD) and light-for-date (LFD) babies (p = 0.090) or between groups with and without concurrent diseases (p = 0.210). In healthy AFD babies, prothrombin levels correlated with gestational age (r = 0.465, p = 0.003) and birth weight (r = 0.458, p = 0.003). In healthy low-birth-weight infants (n = 14) and those with concurrent diseases (n = 17), the changes after vitamin K administration were not significant. The CA-1 method is of clinical use in monitoring coagulation during the early neonatal period. 相似文献
27.
S. Castell M.K. Akmatov N. Obi D. Flesh-Janys A. Nieters Y. Kemmling F. Pessler G. Krause 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2014,57(11):1300-1307
Introduction/objectives
Large scale population-based studies focusing on infectious diseases are scarce. This may be explained by methodological obstacles concerning ascertainment of data on infectious diseases requiring, e.g. collection of data on relatively short-termed symptoms and/or collection of biosamples for pathogen identification during a narrow time window. In the German National Cohort (GNC), a novel self-administered questionnaire will be used in addition to biosampling to collect data on selected infectious diseases and symptoms. The aim of this study was to evaluate in Pretest 2 of the GNC newly added items on self-assessed vulnerability to several infectious diseases and to assess test–retest reliability of the questionnaire.Methods
The study was conducted in two study centres (Hamburg and Hanover) during Pretest 2 of the GNC. A self-administered paper questionnaire was applied. In Hamburg, participants were asked to fill in the questionnaire during their regular visit at the study centre. For test–retest reliability, participants in Hanover filled in the same questionnaire at home twice. To evaluate agreement, item-related percentage agreement and kappa (κ) were calculated. In addition, we computed Bennet’s S and Krippendorf’s alpha (α). Items on self-assessed vulnerability to infections were evaluated by comparing them with the corresponding self-reported frequency of infections. An explanatory factor analysis was applied to construct the scores of self-reported infection frequency and self-assessed vulnerability to infections.Results
The evaluation of the internal consistency of the five-item instrument of self-assessed vulnerability to infections resulted in a Cronbach’s α of 0.78. The factor analysis yielded evidence of one factor. The factor was divided into three groups (lowest quintile classified as “less prone to infections” compared to peers; second, middle and fourth quintiles classified as “similarly prone to infections” and highest quintile classified as “more prone to infections”). Participants classified as “less prone to infections” reported fewer infections than participants classified as “more prone to infections”. Spearman’s correlation of the two scores (self-reported infection frequency and self-assessed vulnerability to infection) was 0.50 (p?0.0001). For quantifying reliability, 88 participants with a median time of 8 days between filling in both questionnaires could be included in the analysis; for items sensitive to disease occurrence between both questionnaires only participants with no relevant disease in this time interval were included (n?=?75). The weighted κ ranged between 0.65 and 0.87 for the items on infectious disease frequency in the last 12 months, for items on symptom frequency in the past 12 months between 0.77 and 0.90, and for items on vulnerability compared to peers between 0.68 and 0.76.Conclusion
A five-item instrument on self-assessed vulnerability to infections seems to be promising, but requires further evaluation. Overall, the questionnaire on self-reported infectious diseases used in Pretest 2 of the GNC is a moderately reliable instrument and, thus, can be applied in future studies on infectious diseases. 相似文献28.
Stefanie Castell G. Krause M. Schmitt M. Pawlita Y. Deleré N. Obi D. Flesch-Janys Y. Kemmling A.M. Kaufmann 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2014,57(11):1270-1276
Background and objectives
Within the German National Cohort (GNC) 100,000 adult women in Germany will be comprehensively interviewed and examined. While women’s health is addressed in the basic interview, direct detection of cervicovaginal microbial colonisation or infection is not part of the examination protocol. In a pilot project the feasibility of female study participants of the GNC collecting a cervicovaginal lavage at home without having to involve a gynecologist or other medical personnel was thus investigated. The ability of the procedure to detect vaginal microbes and conditions including human papillomavirus (HPV), Chlamydia trachomatis and bacterial vaginosis (BV) were also explored.Methods
This cross-sectional study was conducted in two study centers (Hamburg and Hanover) of the GNC during Pretest 2 in 2012 as an add-on module to the main program of the National Cohort. Participants were randomly selected through the population registration office. After providing written informed consent at the study center, participants self-collected a cervicovaginal lavage (Delphi Screener?) at home following written instructions. Participants mailed samples and acceptability questionnaires to the laboratory and the study center, respectively. Acceptability of self-sampling was categorized as consent, partial consent and rejection. The samples were analyzed by multiplex HPV genotyping for the presence of 27 mucosal HPV subtypes. To detect other pathogens “Sexually Transmitted Infection Profiling” (STIP) was used, a novel multiplex polymerase chain reaction (PCR) for various vaginally occurring pathogens/conditions coupled with subsequent bead-based Luminex® hybridization. Human beta-globin and DNA polymerase alpha (PolA) sequences were used as positive controls for the detection of human DNA during HPV detection and STIP, respectively.Results
The participation based on the proportion of all women in Pretest 2 who could take part in the add-on Pretest 2 was 67.3?% (109 out of 162). The age of participants ranged from 20 to 69 years. The self-reported median duration of the collection of the lavage was 5 min. Analysis of the questionnaires (n?=?108) revealed that the self-sampling of a cervicovaginal lavage was acceptable to 98?% of women (106 out of 108), and considered to be easy by 89?% (96 out of 108) as well as user-friendly by 96?% of the women (104 out of 108). Human beta-globin and PolA as markers for human DNA and sample quality were detected in all samples analyzed while HPV as a marker for pathogen detectability was identified in 18 out of 109 samples. Of the 107 samples tested with STIP as a second marker for pathogen detectability, 5 samples were excluded from statistical analyses on bacterial colonization because of signs in the laboratory results of the use of antibiotics. For the computation of the possible occurrence of bacterial vaginosis and candidiasis 7 and 8 samples, respectively, were excluded because of low signal intensities resulting in an evaluation of 95 or 94 samples, respectively. Ureaplasma parvum was detected in 22 out of 102 samples, BV in 14 out of 95 samples and candidiasis in 13 out of 94 samples. Chlamydia trachomatis was not detected in any sample.Conclusion
The feasibility study on cervicovaginal self-sampling indicates that this form of biosampling was very well accepted within the framework of the GNC and feasible in terms of pathogen detection. Its further application in the GNC would allow investigation of transience and persistence, or long-term effects of vaginal (co)infections and colonization. 相似文献29.
Yuta Takeuchi Yuma Ebihara Yoshitsugu Nakanishi Toshimichi Asano Takehiro Noji Yo Kurashima Soichi Murakami Toru Nakamura Takahiro Tsuchikawa Keisuke Okamura Toshiaki Shichinohe Satoshi Hirano 《Asian journal of endoscopic surgery》2020,13(2):215-218
We report a novel technique for combined laparoscopy and thoracoscopy for far‐advanced adenocarcinoma of the esophagogastric junction (AEG). A 56‐year‐old man presented with far‐advanced AEG, and an esophagogastroduodenoscopy revealed a type 2 lesion that encircled the esophagogastric junction. CT revealed stenosis of the esophagogastric junction, suspected invasion into the left side of the diaphragm, and lymph node metastases in the abdomen. We diagnosed Siewert type II AEG (cT4aN1M0, cStage IIIA) according to the Japanese Classification of Gastric Carcinoma, version 14. Laparoscopic and thoracoscopic proximal gastrectomy and lower esophagectomy with double‐tract reconstruction were performed as a palliative resection via a minimally invasive abdominal and left thoracic approach. However, localized peritoneal dissemination was detected. The patient was discharged with no postoperative morbidity. Hence, a minimally invasive abdominal and left thoracic approach provides good visualization, and it is safe for lower esophageal transection and intrathoracic anastomosis in the treatment of locally advanced AEG invading the surrounding tissues. 相似文献
30.