全文获取类型
收费全文 | 3117篇 |
免费 | 161篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 157篇 |
妇产科学 | 110篇 |
基础医学 | 359篇 |
口腔科学 | 39篇 |
临床医学 | 215篇 |
内科学 | 769篇 |
皮肤病学 | 31篇 |
神经病学 | 335篇 |
特种医学 | 304篇 |
外国民族医学 | 10篇 |
外科学 | 334篇 |
综合类 | 14篇 |
预防医学 | 93篇 |
眼科学 | 16篇 |
药学 | 137篇 |
中国医学 | 5篇 |
肿瘤学 | 363篇 |
出版年
2022年 | 20篇 |
2021年 | 50篇 |
2020年 | 39篇 |
2019年 | 36篇 |
2018年 | 48篇 |
2017年 | 26篇 |
2016年 | 49篇 |
2015年 | 63篇 |
2014年 | 73篇 |
2013年 | 93篇 |
2012年 | 133篇 |
2011年 | 155篇 |
2010年 | 90篇 |
2009年 | 94篇 |
2008年 | 122篇 |
2007年 | 130篇 |
2006年 | 161篇 |
2005年 | 126篇 |
2004年 | 101篇 |
2003年 | 116篇 |
2002年 | 114篇 |
2001年 | 98篇 |
2000年 | 102篇 |
1999年 | 102篇 |
1998年 | 72篇 |
1997年 | 79篇 |
1996年 | 70篇 |
1995年 | 56篇 |
1994年 | 52篇 |
1993年 | 39篇 |
1992年 | 80篇 |
1991年 | 59篇 |
1990年 | 68篇 |
1989年 | 59篇 |
1988年 | 61篇 |
1987年 | 57篇 |
1986年 | 50篇 |
1985年 | 49篇 |
1984年 | 39篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 19篇 |
1980年 | 21篇 |
1979年 | 22篇 |
1978年 | 18篇 |
1977年 | 20篇 |
1976年 | 19篇 |
1975年 | 21篇 |
1974年 | 11篇 |
1972年 | 13篇 |
排序方式: 共有3296条查询结果,搜索用时 15 毫秒
91.
92.
Cesare Greco Piero A. Chiavari Giuseppe Campolongo Simona Mariani Fortunato Messa Demetrio Tallarico Michele Schiariti Carlo Gonnella Carlo Gaudio 《Catheterization and cardiovascular interventions》2008,72(4):538-541
Objectives : To reduce risks, discomfort, cost, and operative time for percutaneous patent foramen ovale (PFO) closure, we propose to perform this procedure under transesophageal echo‐guidance using a 10 Fr. catheter introduced through nasal way (TEENW). Background : Transesophageal or intracardiac echocardiography is commonly used to guide percutaneous PFO closure. Sedation needed quite frequently during transesophageal echocardiography, increased patients' discomfort, procedure prolongation, costs, use of both femoral veins, and additional intracardiac manipulations are the main limitations of standard techniques. Methods : We enrolled 20 consecutive patients with a history of cerebral ischemia and PFO with right‐to‐left shunt. In 15 patients Amplatzer® PFO occluder was used, whereas in five patients with longer PFO tunnel (>10 mm) Cardia Intrasept® was selected. Without sedation, a multifrequency monoplane probe, developed for intracardiac echocardiography, was introduced into the nostril and advanced forward the esophagus. Then under echo guidance, the closing device was presented, opened and released. Results : Procedure lasted for an average of 33.3 min, and no complications were seen. At procedure's completion, six patients showed persistence of reduced shunt during Valsalva manoeuvre. At six‐month follow‐up, shunts disappeared in all patients. Conclusion : TEENW is safe and well tolerated, and images' quality is high enough to deserve widespread adoption of this technique for PFO closure. © 2008 Wiley‐Liss, Inc. 相似文献
93.
94.
CL Sanchez CS Biskup S Herpertz TJ Gaber CM Kuhn SH Hood FD Zepf 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2015,18(10)
The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research. 相似文献
95.
Crosslinking the CD27 antigen on T cells provides a costimulatory signal that, in concert with T-cell receptor crosslinking, can induce T- cell proliferation and cellular immune activation. We find that chronic lymphocytic leukemia (CLL) B cells from most patients coexpress both membrane-bound and soluble CD27, along with its newly identified ligand, CD70. The expression of soluble CD27 may preclude leukemic B cells from stimulating T cells via CD70, thereby potentially impairing their ability to function as effective antigen-presenting cells. We find that leukemic B-cell expression of soluble and membrane-bound CD27 can be downmodulated through a CD40-dependent signal. This signal also induces enhanced expression of CD70 on both normal and leukemic B cells. We find that tumor necrosis factor (TNF)-alpha, or the Th1 cytokine interferon (IFN)-gamma, also can induce downmodulation of CD27, whereas Th2-associated cytokines interleukin-4 (IL-4) or IL-10 can enhance leukemic B-cell expression of this accessory molecule. The modulation of CD27 induced by these conditions is accompanied by reciprocal changes in the expression levels of CD70, suggesting that these accessory molecules may be engaged in reciprocal receptor-ligand downmodulation. Consistent with this, we observe that co-culture of CLL B cells with transfected murine plasmacytoma cells that express human CD70 affects downmodulation of CD27 and enhanced expression of CD70 on leukemic B cells, but does not affect expression of CD27 mRNA. However, we find that CD40-crosslinking, in addition to reducing the level of CD27 protein, also reduces leukemic B-cell expression of CD27 mRNA. This argues that the changes in the expression levels of CD27 following CD40-signaling are not simply due to induced increases in the expression levels of CD70. Finally, we demonstrate that reciprocal changes in expression of CD27 and CD70 may contribute to the enhanced antigen-presenting capacity of CLL B cells after CD40-dependent leukemic B-cell activation. These findings expand the understanding of the regulation of costimulatory molecules important in antigen presentation and also have implications for the immunobiology of and therapy for CLL. 相似文献
96.
Barbaro D Boni G Meucci G Simi U Lapi P Orsini P Pasquini C Piazza F Caciagli M Mariani G 《The Journal of clinical endocrinology and metabolism》2003,88(9):4110-4115
The main steps in the management of differentiated thyroid cancer are thyroidectomy, treatment with iodine-131 ((131)I), and follow-up with whole-body scanning (WBS) and serum thyroglobulin (Tg) determination. Both (131)I treatment and follow-up require maximum stimulation of normal or pathological thyroid remnants by TSH. The use of recombinant human TSH (rhTSH) has been shown to be useful for follow-up, whereas previous reports are not univocal regarding the use of (131)I postsurgical ablation of thyroid remnants, at least when low doses (30 mCi) of (131)I are administered. A possible explanation for the diminished effectiveness of (131)I treatment after rhTSH may be the interference of iodine content of L-thyroxine (L-T4) therapy during the protocol of administration of rhTSH. We have evaluated the effectiveness of stimulation by rhTSH for radioiodine ablation of postsurgical remnants, stopping L-T4 the day before the first injection of rhTSH and restarting L-T4 the day after (131)I. The study included two groups of patients: group 1 included 16 patients with differentiated thyroid cancer (15 papillary cancers and 1 follicular cancer, stages I and II), who were treated with 30 mCi (131)I with the aid of rhTSH, using the standard protocol but stopping L-T4 as stated previously; and group 2 included 24 patients with the same features (histology and stage) of disease treated with 30 mCi in the hypothyroid state after L-T4 withdrawal. In both groups, serum TSH reached a very good stimulation level [76-210 U/liter (mean, 112 +/- 11 SE) and 38-82 U/liter (mean, 51 +/- 3 SE), respectively]. At the first WBS (after (131)I treatment), all patients showed thyroid remnants. Furthermore, two patients of the first group and three patients of the second group showed lymph node metastases. After 1 yr, all patients were studied again and underwent WBS with a tracer dose of (131)I and serum Tg measurement using rhTSH with the same protocol in both groups. The percentage of ablation (undetectable Tg and a negative WBS) was higher, although not reaching statistical significance, in patients treated with rhTSH: 81.2% in patients treated by rhTSH withdrawal and 75.0% in patients treated by L-T4 withdrawal, respectively. No patient experienced symptoms of hypothyroidism during the 4 d of L-T4 interruption, and serum T4 remained in the normal range. Urinary iodine was analyzed in both groups and compared with a control group of patients who received, for diagnostic purposes, rhTSH without stopping L-T4. In the first group, urinary iodine was 47.2 +/- 4.0 microg/liter (mean +/- SE; P = 0.21 vs. the second group, P = 0.019 vs. control group). In the second group, urinary iodine was 38.6 +/- 4.0 microg/liter (mean +/- SE; P < 0.001 vs. control group); urinary iodine in the control group was 76.4 +/- 9.3 microg/liter (mean +/- SE). Our data show that rhTSH, as administered in the protocol stated previously, allows at least the same rate of ablation of thyroid remnants when low doses (30 mCi) of (131)I are used. The possible role of interference of iodine content in L-T4 is not surprising if we consider that the amount of iodine in 30 mCi is negligible (5 microg) compared with the amount of iodine content in a daily dose of T(4) ( approximately 50 microg). The cost of rhTSH seems modest compared with the high cost of complex therapeutic regimens in other areas of oncology and in consideration of the well-being of patients and of the high level of effectiveness of the treatment. 相似文献
97.
Raúl Solernó Pablo Pedroni Javier Mariani Ricardo Sarmiento 《Expert review of cardiovascular therapy》2018,16(10):765-770
Background: Fractional flow reserve (FFR) has become a useful tool in the assessment of physiological significance of coronary artery stenosis (CAS), and Adenosine (ADE) is associated with a high incidence of transient side effects. Sodium nitroprusside (NPS) has been proposed as an alternative vasodilator agent. A meta-analysis of studies comparing ADE and NPS for FFR assessment in the same coronary lesions was performed.Methods: Authors searched for articles comparing NPS and ADE for FFR assessment in intermediate coronary lesions published through January 2018. The following keywords were used: ‘fractional flow reserve’ AND ‘nitroprusside’. Data were summarized using weighted mean differences for paired data.Results: Seven studies were identified comprising 342 patients and 401 lesions. Four studies evaluated intravenous ADE and 3 studies intracoronary ADE administration. Weighted means FFR values obtained with ADE and NPS were 0.8411 and 0.8445, respectively (weighted mean difference: 0.00, 95% confidence interval (CI) ?0.01 to 0.01, p = 0,548). Adverse events were significantly reduced with IC NPS (RR = 0.08, 95%CI 0.02–0.30, P < 0.0001).Conclusions: NPS produces similar FFR measurements compared to ADE with a significant reduction in adverse effects. These results may support its use as a suitable alternative to ADE for FFR assessment. 相似文献
98.
Absence of late gadolinium enhancement on cardiac magnetic resonance imaging in ventricular fibrillation and nonischemic cardiomyopathy
下载免费PDF全文
![点击此处可从《Pacing and clinical electrophysiology : PACE》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Aleksandr Voskoboinik MBBS Michael C. G. Wong MBBS Jessica K. Elliott MBBS BMedSc Benedict T. Costello MBBS Sandeep Prabhu MBBS Justin A. Mariani MBBS PhD Jonathan M. Kalman MBBS PhD Peter M. Kistler MBBS PhD Andrew J. Taylor MBBS PhD Joseph B. Morton MBBS PhD 《Pacing and clinical electrophysiology : PACE》2018,41(9):1109-1115
Introduction
Cardiac magnetic resonance (CMR)‐identified late gadolinium enhancement (LGE), representing regional fibrosis, is often used to predict ventricular arrhythmia risk in nonischemic cardiomyopathy (NICM). However, LGE is more closely correlated with sustained monomorphic ventricular tachycardia (SMVT) than ventricular fibrillation (VF). We characterized CMR findings of ventricular LGE in VF survivors.Methods
We examined consecutively resuscitated VF survivors undergoing contrast‐enhanced 1.5T CMR between 9/2007 and 7/2016. We excluded coronary artery disease, hypertrophic cardiomyopathy, amyloid, sarcoid, arrhythmogenic right ventricular cardiomyopathy, and channelopathy. Preexisting implantable cardioverter‐defibrillator (ICD) was a CMR contraindication. VF patients were divided into three groups: (1) NICM, (2) left ventricular (LV) dilatation with normal LV ejection fraction (LVEF), and (3) normal LV size and LVEF. Two groups of NICM patients with and without SMVT were examined for comparison.Results
We analyzed 87 VF patients, and found that LGE was seen in 8/22 (36%) with NICM (LVEF 38 ± 11%, LV end‐diastolic volume index [LVEDVI] 134 ± 68 mL/BSA), 11/40 (28%) with LV dilatation and normal LVEF (LVEDVI 103 ± 17 mL/BSA), 4/25 (16%) with normal LV size and LVEF. Incidence of LGE in NICM patients without prior ventricular tachycardia/VF (LVEF 36 ± 12%, LVEDVI 141 ± 46 mL/body surface area [BSA]) was 117/277 and was not lower than those with VF and NICM (42% vs 36%; P = 0.59). By contrast, 22/37 NICM patients with SMVT (LVEF 42 ± 11%, LVEDVI 123 ± 48 mL/BSA) were LGE‐positive (59% NICM‐SMVT vs 36% NICM‐VF; P = 0.04).Conclusion
Most VF survivors with a diagnosis of NICM did not have LGE on CMR and would not have met primary prevention ICD criteria based on LVEF. Absence of LGE may not portend a benign prognosis in NICM. Novel strategies for determining SCD risk in this cohort are required.99.
Elham Vaez Rohini Indran Abbas Abdollahi Rumaya Juhari Mariani Mansor 《Vulnerable children and youth studies》2015,10(4):321-336
The development of children over time is one of the continuing aims of psychological inquiry. Many studies have concluded that children who grew up in dysfunctional households show inconsistent development across various developmental pathways. Previous studies have consistently concluded how different family factors, such as interparents relationship, parent–child relationships, and emotional relations in families, can explain the outcomes of child behavior problems. Therefore, this paper attempts to review the empirical findings of previous studies that assess the effects of marital relations on child behavioral development by reviewing the literature that supports the association between marital relations and behavioral problems of children. Twenty-seven studies were chosen for their outcomes. This review used online databases such as Google Scholar, Scopus, ProQuest, Psychological and Behavioral Science collection, SAGE full-text collection in psychology, and PsycINFO. The key words used were marital relation, marital conflict, marital satisfaction, child behavior problem, and offspring behavior adjustment. All articles hypothesized that marital relation affects child adjustment and behavior outcomes directly and indirectly. Approximately all the research samples were in the developmental stage (ages 3 to 12). Various methodologies were used in the studies, but some methodological defects in the literature in some way diminished the interpretation of their findings. Results revealed that children who come from families high in conflict are at risk of psychopathological developmental problems in their adolescent years. This review adds to a large collection of literature that highlights the damaging effects of marital conflict on children. Research limitations and suggestions for future studies are outlined. The study provides a concrete basis for further research on this topic considering that married couples and child behavior problems are varied. This review can benefit married and soon-to-be married couples by revealing perceptions into the experiences of others as regards marriage problem solving. 相似文献
100.
Evaluation of breast tumour cell contamination in the bone marrow and leukapheresis collections by RT-PCR for cytokeratin-19 mRNA 总被引:5,自引:0,他引:5