A facile method to functionalize gold nano-tripods with high suspension stability in an aqueous environment.

Here we aim to develop a facile emulsion-based method to prepare tripod gold nanoparticles (AuNPs) with high suspension stability in an aqueous environment. A gyroid-structured polymer template formed by the hydrolysis of a degradable block copolymer, polystyrene (PS)-b-poly(l-lactide), is used for the fabrication of AuNPs. Also, a successful emulsification of dichloromethane (DCM) in the aqueous phase is developed by using thiolated polyethylene glycol (PEG-SH) as the stabilizer. Subsequently, the nanohybrids of PS/Au can be fabricated by templated electroless plating, and then selectively dissolving in the DCM dispersive phase. Most interestingly, a dedicated process for the simultaneous release of the tripod AuNPs from the dissolution of PS associated with PEG-SH at the interface of the emulsion is achieved, giving PEG-SH-functionalized tripod AuNPs dispersed in the aqueous phase, which significantly improves the suspension stabilization of tripod AuNPs. The in situ temperature-programmed electrospray-differential mobility analysis provides a quantitative, statistical analysis of mobility diameter, dynamic shape factor, polydispersity, and colloidal stability.

Structure of outcome beliefs in condom use. The Project RESPECT Study Group.

To study the structure of beliefs about condom use outcomes, the authors derived and tested 4 psychosocial hypothetical models: (a) a 2-factor model of the personal and social outcomes of condom use; (b) a 2-factor model of the pros and cons of the behavior; (c) a 3-factor model (i.e., physical, self-evaluative, and social) of outcome expectancies; and (d) a thematic 4-factor model of the protection, self-concept, pleasure, and interaction implications of the behavior. All 4 models were studied with a confirmatory factor analysis approach in a multisite study of 4,638 participants, and the thematic solution was consistently the most plausible. Self-concept and pleasure were most strongly associated with attitudes toward using condoms, intentions to use condoms, and actual condom use, whereas protection and interaction generally had little influence.

Persistent hypertension in young spinal cord injured individuals resulting from aortic repair.

The development of persistent hypertension in young, previously healthy paraplegic individuals is unusual; it could be postulated that hypertension is a cardiovascular response peculiar to patients who sustained spinal cord injury after surgical repair of the aorta with trauma-related injuries. In a retrospective study of 712 patients sustaining spinal cord injury during the last decade, seven sustained paraplegia after aortic repair that was necessitated by trauma-related injuries. Despite the low incidence of new-onset hypertension in paraplegic patients, five of the seven developed hypertension, of which three required chronic antihypertensive medications. It is well documented that patients with lesions of the neuraxis above the sixth thoracic segment are prone to the phenomenon of autonomic hyperreflexia. This results from interruption of the baroreceptor reflex and the descending tracts of the spinal cord. There is evidence that the renin-angiotensin system, catecholamines, and receptor-site activity play an important role in the control of blood pressure in spinal cord injured patients. Additional investigation of this rare subgroup of spinal cord injured patients may further illuminate the effect of spinal cord injury on autonomic control of the cardiovascular system.

Inflammation of the neck.

In the evaluation of a large series of infectious processes in the cervical region, certain diagnostic sonographic patterns have been established, which prove very helpful in differentiating the various stages and the extension of inflammatory processes. The advantages of sonographic imaging are demonstrated.