全文获取类型
收费全文 | 2229篇 |
免费 | 125篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 69篇 |
妇产科学 | 32篇 |
基础医学 | 193篇 |
口腔科学 | 186篇 |
临床医学 | 241篇 |
内科学 | 549篇 |
皮肤病学 | 33篇 |
神经病学 | 115篇 |
特种医学 | 237篇 |
外科学 | 198篇 |
综合类 | 92篇 |
预防医学 | 106篇 |
眼科学 | 14篇 |
药学 | 197篇 |
中国医学 | 24篇 |
肿瘤学 | 56篇 |
出版年
2022年 | 13篇 |
2021年 | 28篇 |
2020年 | 19篇 |
2019年 | 26篇 |
2018年 | 42篇 |
2017年 | 37篇 |
2016年 | 37篇 |
2015年 | 35篇 |
2014年 | 62篇 |
2013年 | 118篇 |
2012年 | 109篇 |
2011年 | 99篇 |
2010年 | 87篇 |
2009年 | 70篇 |
2008年 | 89篇 |
2007年 | 110篇 |
2006年 | 72篇 |
2005年 | 88篇 |
2004年 | 78篇 |
2003年 | 74篇 |
2002年 | 74篇 |
2001年 | 72篇 |
2000年 | 76篇 |
1999年 | 66篇 |
1998年 | 70篇 |
1997年 | 65篇 |
1996年 | 54篇 |
1995年 | 37篇 |
1994年 | 36篇 |
1993年 | 34篇 |
1992年 | 43篇 |
1991年 | 43篇 |
1990年 | 28篇 |
1989年 | 33篇 |
1988年 | 44篇 |
1987年 | 40篇 |
1986年 | 32篇 |
1985年 | 38篇 |
1984年 | 17篇 |
1983年 | 21篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 17篇 |
1975年 | 7篇 |
1973年 | 10篇 |
1972年 | 13篇 |
排序方式: 共有2362条查询结果,搜索用时 31 毫秒
11.
Laine TP Ahonen A Torniainen P Heikkilä J Pyhtinen J Räsänen P Niemelä O Hillbom M 《Molecular psychiatry》1999,4(2):189-91, 104-5
Dopaminergic transmission has been suggested to be a main mechanism mediating reinforcement, withdrawal and craving associated with alcohol addiction. We measured here striatal dopamine (DA) transporter binding from 27 alcoholics within 4 days after cessation of prolonged heavy drinking and after a 4-week period of abstinence with single photon emission computed tomography (SPECT) using a cocaine analogue, iodine-123-beta-CIT. Controls were 29 healthy volunteers. Blind quantitative analyses of the SPECT data revealed markedly lower DA transporter binding in alcoholics on admission for detoxification than in the non-alcoholic controls. After a 4-week period of abstinence DA transporter binding increased significantly in the alcoholics (P<0.0001) reaching the levels of the healthy controls. The most substantial recovery in DA transporter binding occurred during the first 4 days of abstinence. The data indicate that prolonged heavy drinking decreases DA transporter binding and disturbs synaptic dopamine transport. This may sensitize alcoholics to dopaminergic transmission, which may lead to early relapse after ethanol withdrawal. 相似文献
12.
Grandbastien B Gower-Rousseau C Merle V Dupas JL Yzet T Lerebours E Marti R Laine I Cortot A Salomez JL 《Revue d'épidémiologie et de santé publique》1999,47(1):45-53
BACKGROUND: The period of time required for the diagnosis of a chronic illness depends on initial clinical symptoms and their perception by the patient and the physicians. The aim of this study was to describe the procedures of diagnosis of incident cases of Inflammatory Bowel Disease (IBD). METHODS: Patients reported by the Registry of inflammatory bowel disease of northern France (EPIMAD) in 1994 were included. Standardized questionnaires describing clinical history, patient behavior, medical consultations and examinations were collected by an interviewer practitioner from three sources: patients, general practitioners (GP) and gastroenterologists (GE). Patients were divided in 2 groups according to the time between symptom onset and diagnosis: more than 9 months or less than 9 months (D > 9 and D < or = 9). RESULTS: 258 patients were included: 144 Crohn's disease (CD) (56%), 106 ulcerative colitis (UC) (41%) and 8 chronic unclassifiable colitis (CUC). Median time between symptom onset and diagnosis was 3 months, 196 (76%) patients belonged to the group D < or = 9 and 62 (24%) to the group D > 9. There was no difference between the 2 groups for initial clinical symptoms. The delay between symptom onset and the consultation to the GP and the GE was longer in the group D > 9: respectively 1 month vs 0 and 7.6 vs 2. Thirty-five percent of patients in the group D > 9 had consulted more than one GP vs 14% (p < 0.05). Diagnosis management by the GE was the same in both groups. Patients of group D < or = 9 had more often perceived their symptoms as serious (p < 0.05). CONCLUSIONS: Delay to diagnosis in a quarter of patients with IBD was more than 9 months. This later diagnosis was not due to patient management by the GE but rather to a longer delay to consulting the GP and between GP and GE referral. Patient interpretation of the symptoms could also explain the variability of this delay. 相似文献
13.
RAL Dampney Y. Hirooka PD Potts GA Head 《Clinical and experimental pharmacology & physiology》1996,23(Z3):105-111
- 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.
14.
GA Smith SD Strausbaugh C Harbeck-Weber DM Cohen BJ Shields JD Powers 《Pediatrics》1997,100(5):825-830
OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration = 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups. OUTCOME MEASURES: Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children. 相似文献
15.
Contribution of edema and cerebral blood volume to traumatic brain swelling in head-injured patients 总被引:26,自引:0,他引:26
Marmarou A Fatouros PP Barzó P Portella G Yoshihara M Tsuji O Yamamoto T Laine F Signoretti S Ward JD Bullock MR Young HF 《Journal of neurosurgery》2000,93(2):183-193
OBJECT: The pathogenesis of traumatic brain swelling remains unclear. The generally held view is that brain swelling is caused primarily by vascular engorgement and that edema plays a relatively minor role in the swelling process. The goal of this study was to examine the roles of cerebral blood volume (CBV) and edema in traumatic brain swelling. METHODS: Both brain-tissue water and CBV were measured in 76 head-injured patients, and the relative contribution of edema and blood to total brain swelling was determined. Comparable measures of brain-tissue water were obtained in 30 healthy volunteers and CBV in seven volunteers. Brain edema was measured using magnetic resonance imaging, implementing a new technique for accurate measurement of total tissue water. Measurements of CBV in a subgroup of 31 head-injured patients were based on consecutive measures of cerebral blood flow (CBF) obtained using stable xenon and calculation of mean transit time by dynamic computerized tomography scanning after a rapid bolus injection of iodinated contrast material. The mean (+/- standard deviation) percentage of swelling due to water was 9.37+/-8.7%, whereas that due to blood was -0.8+/-1.32%. CONCLUSIONS: The results of this study showed that brain edema is the major fluid component contributing to traumatic brain swelling. Moreover, CBV is reduced in proportion to CBF reduction following severe brain injury. 相似文献
16.
Acute otomastoiditis and its complications: role of CT 总被引:2,自引:0,他引:2
Acute bacterial (suppurative) otomastoiditis responds to antibiotic treatment; radiologic study is required only when there is clinical suggestion of coalescent mastoiditis, intracranial complications, or an underlying chronic disease. Computed tomography (CT) is the method of choice for evaluating otogenic intra- or extra-cranial complications. CT scans can show stages of disease progression when infection has spread by way of soft tissue, blood, and bone pathways into the dural venous sinuses, meninges, labyrinth, facial nerves, epidural and other intracranial spaces. When there is clinical suggestion of acute coalescent mastoiditis, a CT scan of the temporal bone can confirm the presence of rarefying osteitis, coalescence of the air cells, and subperiosteal abscess. 相似文献
17.
目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。 相似文献
18.
经胸乳径路腔镜甲状腺手术180例的临床研究 总被引:1,自引:0,他引:1
目的探讨经胸乳径路腔镜甲状腺手术技巧及其并发症的防治。方法回顾分析2005年3月至2009年12月经胸乳径路腔镜甲状腺手术180例患者的临床资料。结果本组178例腔镜甲状腺手术顺利完成,2例中转开放手术,其中1例为结节性甲状腺肿,因甲状腺体积大,空间狭小中转开放手术,另1例为原发性甲状腺功能亢进,因粘连严重、创面广泛渗血中转开放手术。全组手术时间70~190 min,平均110 min。术中出血量5~75 ml。术后出现皮肤瘀斑2例,抽搐1例,均于2周后恢复正常。声音嘶哑1例,1个月后恢复正常。住院时间3~6 d,平均4.5 d。结论经胸乳径路腔镜甲状腺手术是一种极富技巧性的手术,甲状旁腺损伤和喉返神经损伤是其严重并发症,规范手术操作能有效减少并发症的发生。 相似文献
19.
BACKGROUND AND AIMS: The Finnish orthopaedic tradition has preferred hemiarthroplasty to internal fixation in femoral neck fracture treatment, while in Sweden internal fixation has been the method of choice. We decided to study whether internal fixation would prove superior to hemiarthroplasty even in displaced femoral neck fractures in patients over 75 years old. MATERIAL AND METHODS: We randomized 32 displaced femoral neck fractures in patients over 75 years old to receive internal fixation or hemiarthroplasty. RESULTS: Fifteen (47%) patients died within two years. Seven of 16 (44%) patients in the internal fixation group were reoperated, none in the hemiarthroplasty group (p = 0.007). Seven of the complications in the internal fixation group developed during the first year and it would have been unethical to continue the study. CONCLUSIONS: We conclude that displaced femoral neck fractures in patients over 75 years should be treated by arthroplasty. 相似文献
20.
Cytokine responses in patients undergoing coronary artery bypass surgery after ischemic preconditioning 总被引:3,自引:0,他引:3
Wei M Kuukasjärvi P Laurikka J Pehkonen E Kaukinen S Laine S Tarkka M 《Scandinavian cardiovascular journal : SCJ》2001,35(2):142-146
OBJECTIVE: The release of proinflammatory cytokines has been shown to be associated with the development of complications after coronary artery bypass grafting with cardiopulmonary bypass. The purpose of the present study was to establish whether ischemic preconditioning (IP) could limit inflammatory cytokines release in patients undergoing elective coronary artery bypass surgery. METHODS: Twenty-two patients with multiple-vessel coronary artery disease and stable angina admitted for first-time elective coronary artery bypass surgery were randomized into control or ischemic preconditioning groups. Patients in the IP group were exposed to two cycles of two-minute myocardial ischemia, followed by three minutes of reperfusion, at the beginning of the revascularization operation, before the cross-clamping and ischemic period used for coronary artery bypass graft anastomosis. Peripheral plasma levels of TNF-alpha, IL-6, IL-8 and IL-10 were measured perioperatively. RESULTS: Significant elevation of IL-6, IL-8 and IL-10 were observed in both groups after reperfusion. Ischemic preconditioning has no effect on cytokine release in the early stage after reperfusion. Arterial blood IL-6 levels in the preconditioning group were significantly lower than in controls at 20 h after declamping (52.93 +/- 9.79 vs 96.04 +/- 17.56 pg/ml, p < 0.05). CONCLUSIONS: The results indicate that ischemic preconditioning results in no effect on systemic inflammatory cytokine release in the early stage but a delayed reduction in IL-6 levels at 20 h after reperfusion. 相似文献