全文获取类型
收费全文 | 251271篇 |
免费 | 15849篇 |
国内免费 | 1068篇 |
专业分类
耳鼻咽喉 | 2681篇 |
儿科学 | 6220篇 |
妇产科学 | 4591篇 |
基础医学 | 31597篇 |
口腔科学 | 4919篇 |
临床医学 | 25564篇 |
内科学 | 52892篇 |
皮肤病学 | 3663篇 |
神经病学 | 25450篇 |
特种医学 | 11089篇 |
外国民族医学 | 13篇 |
外科学 | 39538篇 |
综合类 | 2613篇 |
现状与发展 | 1篇 |
一般理论 | 183篇 |
预防医学 | 17327篇 |
眼科学 | 5879篇 |
药学 | 16371篇 |
1篇 | |
中国医学 | 360篇 |
肿瘤学 | 17236篇 |
出版年
2023年 | 1457篇 |
2022年 | 2429篇 |
2021年 | 5771篇 |
2020年 | 3340篇 |
2019年 | 5406篇 |
2018年 | 6505篇 |
2017年 | 4807篇 |
2016年 | 5360篇 |
2015年 | 6284篇 |
2014年 | 9026篇 |
2013年 | 12086篇 |
2012年 | 18628篇 |
2011年 | 19281篇 |
2010年 | 10852篇 |
2009年 | 9987篇 |
2008年 | 16995篇 |
2007年 | 17871篇 |
2006年 | 17318篇 |
2005年 | 17111篇 |
2004年 | 16057篇 |
2003年 | 14634篇 |
2002年 | 13953篇 |
2001年 | 2082篇 |
2000年 | 1523篇 |
1999年 | 2150篇 |
1998年 | 2930篇 |
1997年 | 2332篇 |
1996年 | 1994篇 |
1995年 | 1809篇 |
1994年 | 1562篇 |
1993年 | 1535篇 |
1992年 | 1018篇 |
1991年 | 945篇 |
1990年 | 800篇 |
1989年 | 761篇 |
1988年 | 699篇 |
1987年 | 625篇 |
1986年 | 640篇 |
1985年 | 685篇 |
1984年 | 919篇 |
1983年 | 792篇 |
1982年 | 1048篇 |
1981年 | 971篇 |
1980年 | 845篇 |
1979年 | 469篇 |
1978年 | 517篇 |
1977年 | 453篇 |
1976年 | 424篇 |
1975年 | 317篇 |
1974年 | 317篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Wayne K Nelson Scott G Houghton Dawn S Milliner John C Lieske Michael G Sarr 《Surgery for obesity and related diseases》2005,1(5):481-485
BACKGROUND: Neither the presence nor prevalence of enteric hyperoxaluria has been recognized after Roux-en-Y gastric bypass (RYGBP). We have noted a high rate of oxalate nephrolithiasis and even 2 patients with oxalate nephropathy in this patient population postoperatively. Our aim was to determine the frequency of the occurrence and effects of enteric hyperoxaluria after RYGBP. METHODS: Retrospective review of all patients at our institution diagnosed with calcium oxalate nephrolithiasis or oxalate nephropathy after standard (n = 14) or distal (n = 9) RYGBP. The mean postoperative follow-up was 55 months. RESULTS: A total of 23 patients (14 men and 9 women; mean age 45 years; mean preoperative body mass index 55 kg/m(2)) developed enteric hyperoxaluria after RYGBP, defined by the presence of oxalate nephropathy (n = 2) or calcium oxalate nephrolithiasis (n = 21) and increased 24-hour excretion of urinary oxalate and/or calcium oxalate supersaturation. Enteric hyperoxaluria was recognized after a mean weight loss of 46 kg at 29 months (range 2-85) after RYGBP. Two patients developed renal failure and required chronic hemodialysis. Of the 21 patients with nephrolithiasis, 14 had no history of nephrolithiasis preoperatively, and 19 of 21 required lithotripsy or other intervention. Of the 23 patients, 20 tested had increased oxalate excretion, and 14 of 15 tested had high urine calcium oxalate supersaturation. CONCLUSION: Enteric hyperoxaluria, nephrolithiasis, and oxalate nephropathy must be considered with the other risks of RYGBP. Efforts should be made to identify factors that predispose patients to developing hyperoxaluria. 相似文献
132.
133.
134.
BACKGROUND: Production of grammatical morphology is typically impaired in agrammatic aphasic individuals, as is their capacity to produce the syntactic structure responsible for licensing that morphology. Whether these two impairments are causally related has been an issue of long-standing debate. If morphological deficits are a side-effect of underlying syntactic ones, as has been claimed (Friedmann & Grodzinsky, 1997; Izvorski & Ullman, 1999), therapy which improves the syntactic deficit should remediate the morphological deficit as well. This paper reports a case study of one individual with such co-occurring impairments and describes their recovery in response to linguistically-motivated treatment targeting his syntactic deficits. METHODS #ENTITYSTARTX00026; PROCEDURES: MD is a 56 year-old male diagnosed with non-fluent Broca's aphasia subsequent to a left-hemisphere CVA, with limited capacity to produce syntactically complex utterances and grammatical morphology. He was enrolled in therapy using Treatment of Underlying Forms (TUF; Thompson & Shapiro, 2005), targeting production of sentences involving Wh-movement (object relative clauses). MD participated in twice-weekly treatment sessions for approximately two months, with daily probes assessing his production of treated and untreated sentence types. In addition, probes assessing his grammatical morphology and sentence production were administered pre- and post-treatment. OUTCOMES #ENTITYSTARTX00026; RESULTS: Pre-treatment scores in tests of grammatical morphology and sentence production indicated deficits in both domains. During treatment, MD successfully acquired production of a variety of sentence with Wh-movement, though this did not generalize to sentences involving a grammatically distinct movement operation (NP-movement). Post-treatment scores also indicated a lack of improvement in production of grammatical morphology. CONCLUSIONS: The dissociation between MD's morphological and syntactic recovery indicates that the recovery of syntactic and morphological processes in aphasia may occur independently. This result is thus surprising under approaches in which morphological and syntactic impairments are strongly and causally related in aphasia, such as the Tree-Pruning Hypothesis (Friedmann, 2001; Friedmann & Grodzinsky, 1997). Further, these results reinforce the conclusion that aphasia treatment can lead to generalization, but only to linguistic material which is in a subset relation to trained structures (Thompson, Shapiro, Kiran & Sobecks, 2003). 相似文献
135.
Late-onset and Recurrent Neonatal Group B Streptococcal Disease Associated with Breast-milk Transmission 总被引:2,自引:0,他引:2
Michael Kotiw Gwang W. Zhang Grant Daggard Elizabeth Reiss-Levy John W. Tapsall Andrew Numa 《Pediatric and developmental pathology》2003,6(3):251-256
The purpose of the study was to determine the epidemiological relationships in three unrelated cases of neonatal late-onset Group B streptococcal (GBS) disease and maternal breast-milk infection with GBS. All deliveries were by cesarean section; case 1 was at term, and cases 2 and 3 were at 32- and 33-wk gestation, respectively. Case 1 relates to a mother with clinical mastitis and recurrent GBS infection in a 20-day-old male infant. Following antibiotic therapy and cessation of breast-feeding, the infant recovered without sequelae. Case 2 refers to a mother with clinical mastitis and the occurrence of late-onset GBS disease in 5-wk-old male twins. Despite intervention, one infant died and the second became ill. Following antibiotic therapy and cessation of breast-feeding, the surviving infant recovered without sequelae. Case 3 refers to a mother with sub-clinical mastitis and late-onset GBS infection occurring in a 6-day-old female twin. Following intervention, the infant recovered but suffered a bilateral thalamic infarction resulting in developmental delay and a severe seizure disorder. Following recovery of GBS from an inapparent mastitis and cessation of breast-feeding, the second infant remained well. Blood cultures from all affected infants and maternal breast milk were positive for GBS. Epidemiological relationships between neonatal- and maternal-derived GBS isolates were confirmed by a random amplified polymorphic DNA polymerase chain reaction assay (RAPD-PCR). This study is significant in that it has demonstrated that maternal milk (in cases of either clinical or sub-clinical mastitis) can be a potential source of infection resulting in either late-onset or recurrent neonatal GBS disease. 相似文献
136.
Coras Brigitte MD Hohenleutner Ulrich MD Landthaler Michael MD Hohenleutner Silvia MD 《Dermatologic surgery》2005,31(3):331-333
BACKGROUND AND OBJECTIVES: Two absorbable polydioxanone threads are compared regarding intraoperative handling qualities, scar dehiscence, and possible side effects. METHODS: In 30 excisions, half of each suture was performed with PDS II (Ethicon GmbH, Norderstedt, Germany), whereas the other half was closed with Serasynth (Serag-Wiessner, Naila, Germany). Clinical evaluation for scar spreading, spitting of the sutures, hypertrophic scarring, or suture granuloma was performed 3 and 6 months after surgery. RESULTS: No significant difference in scar spreading, hypertrophic scarring, or the incidence of suture granuloma was noted. A significantly lower frequency of spitting was seen with Serasynth than with PDS. The handling and suturing properties of SerasynthM were estimated to be slightly superior compared with those of PDS. CONCLUSION: Our study shows that PDS and Serasynth provide equal cosmetic results when applied in an appropriate suturing technique. Possibly owing to its better pliability, the frequency of spitting was lower with Serasynth. 相似文献
137.
Does Additional Doxorubicin Chemotherapy Improve Outcome in Patients with Hepatocellular Carcinoma Treated by Liver Transplantation? 总被引:5,自引:0,他引:5
Herwig Pokorny Michael Gnant Susanne Rasoul-Rockenschaub Bernd Gollackner Birgit Steiner Günter Steger Rudolf Steininger Ferdinand Mühlbacher 《American journal of transplantation》2005,5(4):788-794
The aim of this prospective randomized study was to determine whether additional doxorubicin chemotherapy improves outcome in patients with hepatocellular carcinoma (HCCA) treated by liver transplantation. Stratification parameters were tumor stage (UICC I-IVa), gender, age 50 years, α-fetoprotein 20 ng/mL, cirrhosis and HbsAg status. For pre-operative chemotherapy doxorubicin (15 mg/m2 ) was given biweekly, intra-operative chemotherapy was a single dose administered before surgical manipulation. Post-operative chemotherapy from day 10 was as given preoperatively for a total dosage of 300 mg/m2 . Outcome parameters were overall survival (OS) and disease-free survival. Of the 75 consecutive patients who received liver transplantation for treatment of HCCA, 62 patients were enrolled. Thirty-four patients were randomized in the chemotherapy group; 28 patients were in the control group and transplanted only. OS rates at 5 years were 38% in the chemotherapy group and 40% in the control group, disease-free survival rates at 5 years 43% and 53%, respectively. Tumor stage and vascular invasion were identified as independent risk factors for recurrence of disease. Doxorubicin chemotherapy did not improve organ survival and disease-free survival in patients undergoing liver transplantation for HCCA. 相似文献
138.
Michael W Ross Amy Jo Harzke Deborah P Scott Kelly McCann Michael Kelley 《AIDS education and prevention》2006,18(6):504-517
We report select outcomes from an evaluation of Project Wall Talk, a community-based, peer-led HIV prevention education program implemented in 36 Texas State prison units. Peer educators completed questionnaires prior to receipt of a 40-hour intensive training (N = 590) and at 9-month follow-up (N = 257). Students (N = 2506) completed questionnaires pre- and post-receipt of peer educator-led HIV education sessions. Peer educators and their students showed significant increases in HIV-related knowledge. Peer educators showed significant increases in assessment of their skills as educators. For both peer educators and students, significant differences in HIV-related knowledge were indicated across categories of prior educational level attained and race/ethnicity; no such differences were indicated at follow-up. Compared with baseline, a significantly greater proportion of peer educators reported ever having had an HIV test. After receiving peer-led education, a significantly smaller proportion of students reported they knew their HIV status and more indicated plans to take an HIV test. Additionally, in months 12 and 18 following program implementation, the numbers of HIV tests at the five units that implemented the peer education program were roughly twice that of five, matched comparison units without the peer education program. Based on peer educator reports, we projected that peer educators (N = 257) may have as many as 84,000 or more annual opportunities to share HIV-related knowledge with other prisoners outside the classroom. 相似文献
139.
This study describes the impact computer training has on the health outcomes of older adults at a community center and its
implications for influencing computer training practices. Our objective is to understand and link this group's self-reports
of their health arising from attending lessons to improve the content and delivery of computer tuition. 相似文献
140.
OBJECTIVE: To assess the utility and reliability of echocardiographic assessment of hemidiaphragm motion abnormalities in pediatric cardiothoracic patients. DESIGN: Retrospective observational study, with post hoc blinded assessment of echocardiographic and fluoroscopic results. SETTING: Tertiary care center. PATIENTS: Thirty-six consecutive pediatric cardiothoracic patients with suspected hemidiaphragm paralysis were identified and included in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The results of both echocardiographic and fluoroscopic studies on all patients were included. In addition, blinded review of study results were performed. The sensitivity and specificity of fluoroscopy in identifying hemidiaphragms that needed plication were 100% and 74%, respectively. The positive predictive value was 55%; negative predictive value was 100%. Comparing reported diagnoses with blinded review of the studies showed poor agreement; reviewers agreed with 89% diagnosed as normal, 44% of paralyzed, and 76% of paradoxical hemidiaphragms. The sensitivity and specificity of echo in identifying hemidiaphragms that needed plication were 100% and 81%, respectively. The positive predictive value and negative predictive value were 66% and 100%. Comparing reported diagnoses with blinded review, reviewers agreed with 97% diagnosed as normal, 81% of paralyzed, and 100% of paradoxical hemidiaphragms. Echocardiography was less accurate in discriminating between paralyzed and paradoxical diaphragm motion. Echocardiography was specific for paradoxical motion, since both patients identified by echocardiography were confirmed by fluoroscopy, but it was not sensitive. In nine patients, echo showed paralyzed motion that was identified by fluoroscopy as paradoxical. CONCLUSIONS: This study supports the use of echocardiography in the assessment of diaphragm function. When the diaphragms are clearly visualized by echo, as they are in the majority of cases, the addition of an additional fluoroscopic study adds no clinical value. The differentiation between paralyzed and paradoxical motion is unreliable by both imaging modalities. 相似文献