粘弹性圆柱壳在轴向恒压下的动力稳定性

基于Timoshenko-Mindlin假设,得到考虑粘弹性的各向同性圆柱壳及纤维增强正交铺设层合圆柱壳在轴向恒压下的动力学方程。文中对两端简支的圆柱壳进行了分析,依Laplace变换,导出动力稳定的特征方程,由Routh-Hurwitz判据建立动力稳定性条件,对两类圆柱壳讨论了横向剪切变形的影响。     

The relationship of attention deficit hyperactivity disorder and conduct disorder to juvenile delinquency: legal implications

Attention deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) are both disorders of childhood and adolescence that all too frequently extend into adulthood. But just what is the relationship between these two disorders? This study explores the overlap between these two disorders as they relate to juvenile delinquency; both are significant risk factors for the development of antisocial behavior. But there is more significance to the presence or absence of ADHD or CD in later antisocial behavior. Higher levels of defiant and/or aggressive behavior lead to antisocial acts as compared with lower levels of defiance and antisocial acts. Boys diagnosed with ADHD have higher felony rates than normal control boys, yet ADHD is not nearly as strong a predictor of offending behavior as is CD in study subjects. The presence of both CD and ADHD contributes to illegal behavior, and it is likely that early intervention in both disorders will reduce the prevalence of antisocial behavior.     

Exceptionally high seizure threshold: ECT device limitations

Numerous studies have confirmed the distinct biological behavior of two subsets of prostate cancer diagnosed incidentally after either transurethral resection (TURP) or open prostatectomy for presumed benign prostatic hyperplasia (BPH). Focal, low-grade lesions are associated with a low risk for clinical progression and are designated as stage T1a or A1. These cases have traditionally been managed conservatively with close clinical observation. In contrast, multifocal, high-volume, or high-grade tumors are associated with a more aggressive clinical course and are designated as stage T1b or A2. Early definitive intervention is usually advocated for these latter patients. Therefore, accurate pathological assignment to either stage T1a or T1b is crucial for selection of appropriate management options. A variety of methods for staging patients with incidentally detected prostate cancer have been proposed, including detailed histological analysis, repeat TURP or transurethral biopsy, serial prostate-specific antigen (PSA) analysis, and imaging with either transrectal ultrasound (TRUS) or magnetic resonance (MRI) techniques. This article critically examines the clinical utility of these staging modalities for patients with incidentally detected prostate cancer.     

Immunity to Cryptosporidium muris infection in mice is expressed through gut CD4+ intraepithelial lymphocytes

The role of gut intraepithelial lymphocytes (IEL) in immunity to cryptosporidial infection was investigated with a murine infection model involving Cryptosporidium muris. Oocyst shedding was monitored in severe combined immunodeficiency (SCID) mice infected with C. muris following intravenous injection of mesenteric lymph node (MLN) cells or intestinal IEL from BALB/c donor mice which were naive or previously infected with C. muris. SCID mice receiving no lymphoid cells developed chronic infections and excreted large numbers of oocysts until the end of the experiment. SCID mice injected with IEL from immune animals, however, were able to overcome the infection, and furthermore, these animals produced fewer oocysts and recovered sooner than ones which received IEL or MLN cells from naive BALB/c donors. Similar levels of protection were obtained in SCID mice injected with either 2 X 10(6) IEL or MLN cells from immune donor mice. Depletion of CD4+ cells from immune IEL, however, abrogated the ability to transfer immunity to SCID mice, while depletion of CD8+ cells only marginally reduced the protective capacity of immune IEL. Finally, control SCID mice which received no lymphocytes had < or = 1% CD4+ cells in the IEL from the small intestine, whereas the IEL from SCID mice recovered from infection, as a result of injection with immune IEL, contained 15% CD4+ cells. Thus, the ability to control C. muris infection correlated with the presence of the protective CD4+ cells in the gut epithelium.     

On the possible role of positive end-expiratory pressure ventilation in the treatment of chylothorax caused by blunt chest trauma

Recent reports on the treatment of chylothorax postulate a benefit to ventilator therapy, especially using positive end-expiratory pressure (PEEP). This report describes the use of mechanical ventilation with PEEP in the management of a 24-year-old male motorcyclist who sustained a ligamentous Chance fracture of the thoracic spine at the T6-7 level with bilateral traumatic chylothorax. Treatment of the chylothorax consisted of high PEEP ventilation, bilateral chest tube thoracostomies, and total parenteral nutrition. The chylothoraces resolved within 4 days of treatment and mechanical ventilation was stopped. Ventilator therapy of traumatic chylothorax and the physiologic grounds for its use are discussed. A review of the literature and experimental evidence seem to suggest that ventilator treatment of traumatic chylothoraces is effective.