Design characteristics for temporomandibular joint disc tissue engineering: learning from tendon and articular cartilage

Tissue engineering of chondrocytic or fibroblastic musculoskeletal tissues has been relatively well studied compared with that of the temporomandibular joint (TMJ) disc. Early attempts at tissue engineering the disc have been misguided owing to a lack of understanding of the composition and function of the TMJ disc. The objective of this review is to compare the TMJ disc with a chondrocytic tissue (hyaline articular cartilage) and a fibroblastic tissue (tendon) to understand better the properties of this fibrocartilaginous tissue. The TMJ disc has 25 times more glycosaminoglycan (GAG) per dry weight than tendon but half that of articular cartilage. The disc's tensile modulus is six times more than cartilage but orders less than tendon. The GAG content and tensile modulus suggest that the TMJ disc is characterized as a tissue between hyaline cartilage and tendon, but the disc appears more tendon like when considering its collagen make-up and cell content. Like tendon, the TMJ disc contains primarily collagen type I at 85 per cent per dry weight, while articular cartilage has 30 per cent less collagen, which is type II. Knowledge of quantitative comparisons between joint tissues can give extensive insight into how to improve tissue engineering of the TMJ disc.     

Measurement of thrombus formation on intravascular catheters

War is a complex social situation due to the interplay of multiple factors. Economical and political ones are of utmost importance, but human attitudes and motivations must be also taken into account. Being desirable to modify human transactions in such a way that they do not interfere with the basic right of everyone to a condition of physical and mental well-being, war must be abolished. The author contends that an understanding of behaviour through Psychology can be helpful in that aim. Aggression is considered the principal psychological cause of war. It is worth while to differentiate between aggression as an instrument for attaining a special end, and as pure hostility. Only in the first form, it is held here, does it play an important role in war. Psychogists must deal also with a wide range of states of mind that can be "served" by aggression: feelings of inferiority or insecurity, fear, greed, projections, compensations, rationalizations, etc. Scientific approach is not the only one Physiology brings to war prevention. It is equally important the wide dissemination of its conclusions among the general public. Information on the dynamics that prompt people to decide war would make it easier to control. This applies not only to political or military leaders, but also to civil populations. Concerning those two possible contributions of psychologists, scientific and educative, it is suggested the extensive use of psychodramatic techniques. Their richness lie in the lifelike experiences they convey to the participants, and particular aptitude to promote changes of attitudes. Investigation and information on the psychological processes related to war should be undertaken by international organizations of social scientists, acting simultaneously in several countries. Some of the initial steps they could further: 1) that prevention of war be a current subject matter in psychological courses; 2) that the World Health Organization take interest in this subject; 3) that psychologists participate in international political and economical bodies in order to clarify the psychological factors leading to war.     

TPS6211x电源供应设计的实际考虑

作者:Jeff Falin、Bill Johns·电源管理产品/便携式电源DC/DC应用TPS6211x dc/dc转换器是一种同步降压转换器,其输入电压最高可达17V,输出电压范围为1.2-16V,输出电流高达1.5A。该器件可以高效地将两节锂离子电池、铅酸蓄电池或12V-15V系统电压降至5V、3.3V或者更低。图1为典型应用电路。图1:典型应用本文将提供TPS62111x降压转换器的示例应用并对关键特性进行总结,以供实际设计参考。外部组件的尺寸要求集成FET及内部补偿功能可进一步减少外部组件教。假设不使用集成输出电压与输入电压监控电路,则固定输出电压(5V或3.3V)时仅…     

我真不是素描

<正>简单的纯白瓷块加上素描感十足的黑色包边,营造出立体插画般的视觉错觉。英国陶艺家Katharine Morling用坚硬的陶瓷创作出其他瓶瓶罐罐绝对没有的3D梦幻感。一台堪称古董级别的收银机内似乎装了太多的硬币,抽屉怎么也关不上,一旁放着订书机、记事本、笔筒等小杂物。如果不是有一圈黑色包边清晰地勾勒出轮廓,它们就像是微融的白巧克力。再仔细一看,似乎又像用柔软的纸张剪出的纸艺美物。然而轻轻敲几下,清脆     

Cardiac syncope due to transient coronary artery occlusion: the role of percutaneous angioplasty

A case of cardiac syncope is presented, associated with single vessel coronary disease. The mechanism of the syncope would appear to be a ventricular arrhythmia with transmural myocardial ischaemia due to transient occlusion of the diseased coronary artery. The symptoms and electrocardiographic abnormalities were reproduced and subsequently abolished by percutaneous coronary angioplasty.     

The effects of deprenyl on methamphetamine-induced dopamine depletions

The effects of deprenyl on methamphetamine-induced dopamine depletions were studied in mice. Four SC injections of 12.5 mg/kg of methamphetamine at two-hour intervals caused substantial (72-82%) and long-lasting depletions of striatal dopamine. Pretreatment with either 25 or 40 mg/kg of deprenyl did not significantly alter the magnitude of this depletion. These results indicate that, unlike what is observed following MPTP, there is no protection afforded dopaminergic cells by deprenyl pretreatment in the methamphetamine model of parkinsonism.