Catalysis with inorganic membranes

Catalytic inorganic membranes are among the most challenging and intriguing porous materials. Consisting of a thin film of mesoporous or microporous inorganic material deposited on a macroporous material, catalytic membranes are multifunctional materials that must be engineered for both chemical and physical properties. New approaches to carrying out chemical reactions are possible by tailoring the membrane catalytic activity and selectivity, permselectivity, and other thin film properties. Readers are referred to several recent reviews of inorganic membranes, in particular, Zaspalis and Burggraaf, Armor, Gellings and Bouwmeister, Hsieh, Stoukides, and Tsotsis et al. Inorganic membranes are most conveniently classified according to pore size (see introductory article). Of particular importance is the ratio of the pore size to the molecular mean free path (MFP). Decreasing pore dimensions lead to increased selectivity with corresponding loss of permeability. Macroporous membranes have a pore size much larger than the MFP, leading to molecular (bulk) diffusion or viscous flow. Knudsen diffusion dominates in the mesoporous regime, where the pore size is comparable to the MFP. In addition, surface diffusion of the molecules along the pore walls may contribute, leading to an enhanced flux of the adsorbed species along the walls. The microporous regime is encountered when the pore size is comparable to the molecules. This regime makes possible much higher permselectivities, which depend on both molecular size and specific interactions with the solid. Finally, in dense membranes, molecular transport occurs through a solution-diffusion mechanism, which also involves specific interactions between the solute and membrane

Reactive Attachment Disorder: Challenges for Early Identification and Intervention within the Schools

Attachment is of key importance in childhood development. The quality of attachment relationship between the child and parent/primary caregiver may have an effect on the child and future relationships and social success (Rubin, Bukowski, & Parker, 1998). When a child fails to bond with a caring adult, attachment becomes disordered and children may not be able to bond appropriately or at all with other people. This inability to relate and connect with others may disrupt or arrest not only children\u27s social development, but also their overall development. The purpose of this review is to synthesize information and research on characteristics, diagnosis, and interventions currently in practice in working with young children with Reactive Attachment Disorder (RAD). A discussion will highlight the themes found during this review and conclude with implications for intervention and practice

Age Moderates the Effect of Self-Paced Exercise on Exercise Adherence among Overweight Adults

Objective: The present study tested the hypothesis that the effect of self-paced exercise on adherence to exercise programs is more pronounced with increasing age. Method: Fifty-nine low-active overweight adults (18-65 years) were encouraged to walk 30 to 60 min/day and randomized to either self-paced (n = 30) or prescribed moderate-intensity (n = 29) conditions. Results: The effect of study condition was moderated by age (main effect: b = 6.14, SE = 2.54, p = .02; Condition × Age: b = −11.55, SE = 3.77, p \u3c .01), such that among participants \u3e50 years, those in the self-paced condition exercised 6 more min/day than participants in the prescribed moderate-intensity condition (p = .02), whereas among participants \u3c50 \u3eyears, those in the self-paced condition exercised 5.4 fewer min/day compared with those in the moderate-intensity condition (p = .05). Affective response to physical activity did not mediate the moderating effect of age. Discussion: As age increases, adults may be more likely to adhere to self-paced versus prescribed moderate-intensity exercise

Affective response as a mediator of the association between the physical and social environment and physical activity behavior

Perceptions of the physical and social environment have been shown to be predictive of physical activity (PA) behavior. However, the mechanisms of this association have not been examined. Affective response to PA was examined as a putative mediator of the association between perceptions of the PA environment and subsequent PA behavior. As part of a PA promotion study, 59 low-active overweight or obese but otherwise healthy adults completed real-time assessments of the perceived physical and social PA environment, affective response to PA, and PA behavior over a 6-month period. As hypothesized, decreased latency to and greater duration of subsequent PA was predicted by engaging in PA with a partner (b = 17.24, SE = .45, p \u3c .01), engaging in PA outdoors versus indoors (b = 3.70, SE = 0.67, p \u3c .01), and perceived pleasantness of the physical (b = 0.59, SE = .17, p \u3c .01) and social settings (b = 0.68, SE = .16, p \u3c .01). Affective response to PA (a shift toward feeling good versus bad during PA) mediated the association between engaging in PA with a partner (a path: 0.53(.11), p \u3c .01, b path: 0.42(.12), p \u3c .01, ab path: 0.22(.08), 95% CI .09–.41) and perceived pleasantness of the physical (a path: .38(.02), p \u3c .01; b path: .65(.23), p = .01; ab path: .25(.09), 95% CI .08–.43) and social setting (apath: .35(.02), p \u3c .01; b path: .57(.23), p = .01; ab path: .20(.08), 95% CI .03–.37) and PA behavior, but not the association between engaging in PA outdoors versus indoors and PA behavior. These findings suggest that perceived environmental variables may have their effects on PA through the process of psychological hedonism

Cystatin C deficiency in human atherosclerosis and aortic aneurysms

The pathogenesis of atherosclerosis and abdominal aortic aneurysm involves breakdown of the elastic laminae. Elastolytic cysteine proteases, including cathepsins S and K, are overexpressed at sites of arterial elastin damage, but whether endogenous local inhibitors counterbalance these proteases is unknown. We show here that, whereas cystatin C is normally expressed in vascular wall smooth muscle cells (SMCs), this cysteine protease inhibitor is severely reduced in both atherosclerotic and aneurysmal aortic lesions. Furthermore, increased abdominal aortic diameter among 122 patients screened by ultrasonography correlated inversely with serum cystatin C levels. In vitro, cytokine-stimulated vascular SMCs secrete cathepsins, whose elastolytic activity could be blocked when cystatin C secretion was induced by treatment with TGF-β1. The findings highlight a potentially important role for imbalance between cysteine proteases and cystatin C in arterial wall remodeling and establish that cystatin C deficiency occurs in vascular disease

Interaction-Induced Magnetization of the Two-Dimensional Electron Gas

We consider the contribution of electron-electron interactions to the orbital magnetization of a two-dimensional electron gas, focusing on the ballistic limit in the regime of negligible Landau-level spacing. This regime can be described by combining diagrammatic perturbation theory with semiclassical techniques. At sufficiently low temperatures, the interaction-induced magnetization overwhelms the Landau and Pauli contributions. Curiously, the interaction-induced magnetization is third-order in the (renormalized) Coulomb interaction. We give a simple interpretation of this effect in terms of classical paths using a renormalization argument: a polygon must have at least three sides in order to enclose area. To leading order in the renormalized interaction, the renormalization argument gives exactly the same result as the full treatment.Comment: 11 pages including 4 ps figures; uses revtex and epsf.st

Wavy Strings: Black or Bright?

Recent developments in string theory have brought forth a considerable interest in time-dependent hair on extended objects. This novel new hair is typically characterized by a wave profile along the horizon and angular momentum quantum numbers $l,m$ in the transverse space. In this work, we present an extensive treatment of such oscillating black objects, focusing on their geometric properties. We first give a theorem of purely geometric nature, stating that such wavy hair cannot be detected by any scalar invariant built out of the curvature and/or matter fields. However, we show that the tidal forces detected by an infalling observer diverge at the `horizon' of a black string superposed with a vibration in any mode with $l \ge 1$. The same argument applied to longitudinal ($l=0$) waves detects only finite tidal forces. We also provide an example with a manifestly smooth metric, proving that at least a certain class of these longitudinal waves have regular horizons.Comment: 45 pages, latex, no figure

Clofarabine and high-dose cytosine arabinoside in the treatment of refractory or relapsed acute myeloid leukaemia

Clofarabine (40 mg/m2/day × 5) and high-dose cytosine arabinoside (Ara-C, 1–2 g/m2/day × 5) were used in 10 men and 11 women, at a median age of 45 (22–62) years, with refractory (N = 4) and relapsed (N = 17) acute myeloid leukaemia, after a median of 3 (2–5) prior regimens. Grade 4 myelosuppression was observed in all cases, with two patients dying of bacterial sepsis. Nine patients achieved a complete remission. Disease status, number of prior therapies, and cytogenetic aberrations were not associated with the outcome. However, remission was only achieved with Ara-C at 2 g/m2/day and not 1 g/m2/day (9/15 versus 0/4, P = 0.03)