首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7020篇
  免费   113篇
  国内免费   6篇
耳鼻咽喉   269篇
儿科学   262篇
妇产科学   360篇
基础医学   290篇
口腔科学   112篇
临床医学   355篇
内科学   1402篇
皮肤病学   307篇
神经病学   406篇
特种医学   519篇
外科学   2043篇
综合类   21篇
预防医学   210篇
眼科学   254篇
药学   18篇
中国医学   1篇
肿瘤学   310篇
  2023年   10篇
  2022年   6篇
  2021年   15篇
  2020年   16篇
  2019年   20篇
  2018年   35篇
  2017年   23篇
  2016年   31篇
  2015年   505篇
  2014年   567篇
  2013年   581篇
  2012年   583篇
  2011年   544篇
  2010年   596篇
  2009年   560篇
  2008年   590篇
  2007年   505篇
  2006年   485篇
  2005年   418篇
  2004年   276篇
  2003年   66篇
  2002年   23篇
  2001年   39篇
  2000年   18篇
  1999年   36篇
  1998年   28篇
  1997年   50篇
  1996年   42篇
  1995年   30篇
  1994年   25篇
  1993年   28篇
  1992年   22篇
  1991年   25篇
  1990年   19篇
  1989年   25篇
  1988年   26篇
  1987年   20篇
  1986年   14篇
  1985年   9篇
  1984年   14篇
  1983年   29篇
  1982年   27篇
  1981年   28篇
  1980年   24篇
  1979年   23篇
  1977年   10篇
  1976年   11篇
  1975年   9篇
  1974年   7篇
  1973年   8篇
排序方式: 共有7139条查询结果,搜索用时 15 毫秒
71.
BackgroundApproximately 80% of general surgery residents undertake some form of fellowship training. Our objective was to characterize goals and burdens of the interview process among applicants to Comprehensive Endocrine Surgery Fellowship programs.MethodsParticipants included trainees from 2013 to 2019. Results for ranking questions are presented as a mean rank reported out of the total number of selections.ResultsResponse rate was 54% (n = 75). The most important goal for interviews was meeting the faculty (mean rank 2.4/9), followed by “behind the scenes information” and “make a good impression” (mean rank 3.6 and 3.7, respectively). The most substantial burden for the applicant was expense (mean rank 2.1/7), followed by time away from residency (mean rank 3.1/7). The economic burden of 51% of the applicants was $2,500 to $7,500. Geographic location and expense were the top 2 reasons applicants declined offers of interviews. Despite the process, 76% of respondents indicated that no improvements to the interview process are necessary. Alternative strategies such as videoconferencing or centralized interviews received little support (<10%).ConclusionDespite identifying several burdens, survey respondents believed that in-person interviews are an integral component of the fellowship application process. Indeed, 70% of applicants do not have a first-choice program before interviews, and meeting the faculty is ranked as the greatest priority goal. Our data illustrate the importance of individual specialties evaluating and optimizing their own processes for fellowship interviews.  相似文献   
72.
Summary In 47 medical and postoperative ICU patients with 57 episodes of sepsis and septic shock, cardiovascular parameters including systemic vascular resistance (SVR), cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI) as well as six scoring systems (APACHE II, Elebute, Goris, HIS, SAPS and SSS) were studied regarding their usefulness in the assessment of disease progression and evaluation of response to supplemental sepsis therapy (immunoglobulins, plasmapheresis). Among the hemodynamic parameters, only a prompt SVR improvement significantly discriminated between ultimate survivors and nonsurvivors. Thus, an increase in SVR (>160 dyn*cm–5*sec, within days 0 to 4, persisting for >24 hours) can serve as a prognostically validated response criterion (responders/non-responders: 26/31; mortality: 27% vs. 77%). Non-invasively, the APACHE II score was best suited (specificity: 88%, sensitivity: 67%) to classify hemodynamically defined responders to supplemental sepsis treatment (score-reduction 4 on day 4 after onset of therapy).
Herz-Kreislauf-Parameter und Score-Systeme in der Beurteilung des Therapieerfolges bei Sepsis und septischem Schock
Zusammenfassung Bei 47 internistischen sowie postoperativen Intensivpatienten mit insgesamt 57 Episoden von Sepsis und septischem Schock wurden Herz-Kreislauf-Parameter inklusive systemischer Gefäßwiderstand (SGW), Herzindex, Schlagvolumenindex und linksventrikulärer Schlagarbeitsindex sowie sechs Score-Systeme (APACHE II, Elebute, Goris, HIS, SAPS und SSS) in ihrer Wertigkeit zur Beurteilung des Krankheitsverlaufes sowie des Ansprechens auf additive Sepsistherapie (Immunglobuline, Plasmapherese) untersucht. Von den hämodynamischen Parametern diskriminierte nur der — prompt nachweisbare — Anstieg des SGW signifikant zwischen letztlich überlebenden und nicht überlebenden Patienten. Ein Anstieg des SGW (>160 dyn*cm–5*s innerhalb von vier Tagen, länger als 24 Stunden anhaltend) kann somit als prognostisch validiertes Responder-Kriterium dienen (Responder/Non-Responder: 26/31; Letalität: 27% vs. 77%). Nichtinvasiv erwies sich der APACHE II Score (Kriterium: Score-Abfall 4 bis zum Tag 4 nach Therapiebeginn) zur Klassifizierung der hämodynamisch definierten Therapie-Responder bei additiver Sepsistherapie am besten geeignet (Spezifität: 88%, Sensitivität 67%).
  相似文献   
73.
A prospective outcome study was performed of 100 hip fracture patients at an urban medical center in the United States. After hospitalization 19% were discharged to a rehabilitation facility and 59% were discharged home. At a mean follow-up of 8 months, 81% of patients lived at home, compared to 89% who lived at home prior to the fracture. At follow-up 71% of the patients were able to walk outside with one cane or no aids at all, and 81% were able to perform basic activities of daily living. Half of all patients did not require any home assistance at follow-up. Ten patients had died at follow-up. The goal of operatively treating the patient with a hip fracture is fixation of the fracture with a return to the patient’s pre-fracture functional ability. This study illustrates that patients with hip fractures can be effectively treated and discharged home or to a short-term rehabilitation facility with restoration of their pre-fracture functional status.
Résumé  Une étude prospective sur le devenir de 100 patients présentant une fracture de la hanche a été faite dans un Centre Médical Urbain des USA. Après l’hospitalisation, 19% des patients sont allés en structure de rééducation et 59% ont regagné leur domicile. A un délai moyen de 8 mois, 81% des patients vivent à domicile alors qu’il y en avait 89% avant la fracture. Au délai d’observation, 71% des patients marchent à l’extérieur avec une canne ou sans aide et 81% sont capables des activités habituelles de la vie quotidienne. La moitié des patients n’ont besoin d’aucune assistance à domicile. 10 patients sont morts. Le but du traitement opératoire des patients présentant une fracture de la hanche est la fixation de la fracture pour permettre un retour au niveau de fonction pré-traumatique. Cette étude confirma la possibilité d’un retour à l’état fonctionnel antérieur avec, aprés le traitement, un retour à domicile ou un court séjour en Centre de réadaptation.


Accepted: 8 August 1999  相似文献   
74.
Summary The aim of the present study was to analyse the current epidemiological situation with respect to TBE in the new federal Länder of Germany and in Saarland through detection of the TBEV genome in unengorged ticks using an RT-PCR technique. 22,273 ticks (Ixodes ricinus) were collected in the five new Länder (and some in Bavaria and Baden-Württemberg) and divided into 294 pools. It was possible to detect TBEV RNA in six pools of ticks from Mecklenburg Western-Pomerania [4], Brandenburg [1], Thuringia [1] (and in three pools from Bavaria and Baden-Württemberg). The nucleotide sequence data of the PCR products were analysed and compared. In Saarland 8,780 ticks were collected in 70 habitats from all the geographic regions and analysed using the PCR in 21 pools; two pools produced positive PCR signals (Saarlouis, Perl). We cannot as a result make a general recommendation that TBE-immunization be introduced in Saarland and in the new federal Länder of Germany. In Germany, however, TBE immunoprophylaxis in Bavaria and Baden-Württemberg is very important.
Nachweis des Virus der Frühsommer-Meningoenzephalitis in Zecken einiger Bundesländer mittels Polymerase-Kettenreaktion und nähere Charakterisierung des Virus
Zusammenfassung Das Ziel der vorgelegten Studie ist die Einschätzung der aktuellen epidemiologischen Situation der Frühsommer-Meningoenzephalitis in den fünf neuen Bundesländern und im Saarland mit Hilfe des Nachweises von FSMEV-RNA in ungesogenen Zecken (Ixodes ricinus) durch eine RT-PCR-Technik. 22 273 Zecken wurden in den fünf neuen Ländern (einige auch in Bayern und Baden-Württemberg) gesammelt und in 294 Pools untersucht. Der spezifische RNA-Nachweis gelang viermal in Zecken aus Mecklenburg-Vorpommern, einmal in solchen aus Brandenburg und einmal aus Thüringen. In Bayern und Baden-Württemberg gelang der Virus-RNA-Nachweis dreimal. Die Sequenzdaten der PCR-Amplifikate zeigten, auch im Vergleich mit denen des Prototypstammes Neudoerfl, den hohen Grad der Konservierung im Bereich der 5 NCR. 8780 saarländische Zecken aus allen Gebieten des Bundeslandes wurden in 21 Pools untersucht, positive PCR-Signale konnten in zwei Pools aus Saarlouis und Perl und Umgebung gefunden werden. Der relativ seltene FSMEV-RNA-Nachweis in den neuen Ländern und im Saarland berechtigt nicht, eine generelle Impfempfehlung für diese Gebiete zu geben. Ein Impfschutz sollte jedoch vor Einreise in die Endemiegebiete Bayerns und Baden-Württembergs bestehen.
  相似文献   
75.
  • 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
  • 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
  • 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
  • 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.
  相似文献   
76.
Summary We evaluated teicoplanin for suspected gram-positive infections after inadequate response to initial empiric beta-lactam and aminoglycoside combination therapy. All 20 patients included in this study received either an allogeneic (8 patients) or an autologous (12 patients) bone marrow transplant for acute myeloid leucaemia (AML), non-Hodgkin's-lymphoma (NHL, high grade) or other malignant diseases. All patients developing primary septicaemia of unknown origin (18 patients) or catheter-related septicaemia (2 patients) were treated with 400 mg teicoplanin, administered i.v. once daily in combination with a cephalosporin and an aminoglycoside (ceftazidime 2 g i.v., t.i.d.; netilmicin 400 mg once daily). All patients responded to therapy, 19 patients were clinically cured and one patient improved under therapy. The therapeutic regimen was well tolerated; only one adverse drug reaction was observed. We did not observe any delayed take or prolonged neutropenia or thrombocytopenia with this therapeutic regimen when our patients were compared to other bone marrow transplant patients (who did not receive this antimicrobial therapy). Our results suggest that teicoplanin is a potentially effective and well tolerated antimicrobial agent in bone marrow transplant patients with infections not responding primarily to beta-lactams and aminoglycosides.
Teicoplanin in Kombination mit -Laktamen und Aminoglykosiden bei Knochenmarktransplantatempfängern mit schwerer Sepsis
Zusammenfassung Wir untersuchten Teicoplanin bei vermuteten grampositiven Infektionen nach ungenügendem Ansprechen auf die anfängliche Kombinationstherapie von -Laktam-Antibiotika und Aminoglykosiden. Alle 20 in dieser Studie erfaßten Patienten wurden entweder allogen (8 Patienten) oder autolog (12 Patienten) transplantiert mit folgenden Grundkrankheiten: akute myeloische Leukämie (AML), Non-Hodgkin-Lymphom (NHL) oder andere maligne Erkrankungen. Alle Patienten, die eine primäre Septikämie unbekannten Ursprungs entwickelten (18 Patienten) oder unter einer Katheter-bedingten Septikämie (2 Patienten) litten, wurden mit 400 mg Teicoplanin behandelt. Die Verabreichung von Teicoplanin erfolgte einmal täglich intravenös in Kombination mit einem Cephalosporin und einem Aminoglykosid (Ceftazidim 2 g i.v., 3 ×/die, Netilmicin 400 mg, 1 ×/die). Alle behandelten Patienten sprachen auf diese Therapie an. 19 Patienten wurden klinische geheilt, ein Patient besserte sich unter dieser Therapie. Die Kombinationstherapie wurde gut vertragen, unerwünschte Arzneimittelwirkungen traten während der Studie nicht auf. Wir beobachteten kein verzögertes Angehen des Knochenmarks oder eine Verlängerung der Thrombozytopenie unter dieser Behandlung im Vergleich zu anderen knochenmarktransplantierten Patienten, die diese antimikrobielle Behandlung nicht erhielten. Unsere Ergebnisse zeigen, daß Teicoplanin ein wirksames und gut verträgliches Antibiotikum für knochenmarktransplantierte Patienten ist, die primär nicht auf die Kombinationstherapie mit -Laktam-Antibiotika und Aminoglykosiden ansprechen.
  相似文献   
77.
Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.  相似文献   
78.
Tyrosinemia type I is an autosomal recessive inherited defect of tyrosine metabolism. The underlying cause is a defect of fumarylacetoacetate hydrolase. The disease affects the liver (acute liver failure, liver cirrhosis, hepatocellular cancer), the kidney (tubulopathy with hypophosphatemic rickets), and the peripheral nervous system (paresthesia, vegetative symptoms, progressive paralysis). Beside the hypertyrosinemia the diagnosis can be made on the basis of urinary excretion of a pathological metabolite of the tyrosine metabolism (succinylacetone). Therapeutic options are a regulated phenylalanine/tyrosine diet, a very effective drug therapy (NTBC) that has been available for several years, and in cases of acute liver failure or end-stage liver cirrhosis a liver transplantation.  相似文献   
79.
Ohne Zusammenfassung  相似文献   
80.
In monochorionic twin pregnancies, the risk of developing a twin to twin transfusion syndrome is between 15 and 20%. Using high-resolution ultrasound machines, sonographic images demonstrate the detailed features of placental development. The lambda sign was established for the diagnosis of dichorionic placenta and the T sign for monochorionic placenta at the end of the first trimester. Other sonographic findings of the twin to twin transfusion syndrome are monochorionicity, same sex, polyhydramnios, permanently filled bladder in the recipient, and oligo/anhydramnios of the donor with a slightly filled or empty bladder. Fetoscopic laser treatment has become an accepted procedure to coagulate the placental anastomoses. This development is supported by actual studies about psycho- and neuromotoric development in early childhood, which shows a lower rate of disabled children in the group receiving laser therapy in comparison to the group undergoing amnioreduction. Twin pregnancies complicated by twin to twin transfusion syndrome should be treated in specialized prenatal centers.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号