Stability of a crystal surface in fractional crystallization on a band

The problem on the morphological and thermal stability of a crystal surface in fractional crystallization on a band has been investigated theoretically. A model to describe the dynamics of the development of a striped perturbation of the crystal surface is suggested. It is used as a basis for analyzing the influence of the main factors on the stability, and a stability criterion has been derived. It has been established theoretically that the thermal instability must appear at small Reynolds numbers (Re < 10). Numerical experiments have shown that an increase in the length of the band, its inclination angle, as well as a decrease in the rate of melt feed and in the band motion velocity increase the thermal instability. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 1, pp. 106–113, January–February, 2009.     

Magnetic and EPR studies of edge-localized spin paramagnetism in multi-shell nanographites derived from nanodiamonds

Prolonged (up to 2 h) heat treatment at 1600 °C of nanodiamond particles (5 nm) leads to their conversion to the mixture of quasi-spherical carbon onions and multi-shell polyhedral nanographites. Structural and magnetic properties of two (A and B) series of nanographite samples obtained at various annealing intervals were studied. XRD data show that both multi-shell nanographite samples have practically the same crystalline structures. HRTEM evidences that the most of particles obtained by short time (7 min) annealing have a spherical like shape whereas the long time (~ 2 h) annealing leads to the majority of particles having a polyhedral shape with a hollow inside. Electronic and magnetic properties of these nanocarbons were investigated by magnetic susceptibility and EPR. Annealing results in entire transformation of the EPR signal of nanodiamond to new EPR signals of various line shapes and widths. These signals are extremely sensitive to ambient oxygen. Concentrations for all EPR active spins vary from ~ 1 × 10¹⁹ spins/g (7 min) to ~ 2 × 10¹⁹ spins/g (2 h). Temperature dependences of EPR spectra' parameters were obtained for vacuum-processed samples within the range 4?600 K. Intensity vs. T plots may be well-fitted by the combination of Curie–Weiss and temperature-independent Pauli susceptibility contributions. The latter one increases on heat treatment. Significant extension of electron spin-lattice relaxation time on decreasing temperature was found.     

A two-term MEDLINE search strategy for identifying randomized trials in obstetrics and gynecology

In this study, we examined whether endothelin (ET) plays a role in the short-term increase in mean arterial pressure (MAP) after nitric oxide synthase (NOS) inhibition with N(omega)-nitro-L-arginine methyl ester (L-NAME) in stroke-prone spontaneously hypertensive rats (SHRSPs). Experiments were performed by using Inactin-anesthetized male SHRSPs that were pretreated with chlorisondamine to block reflex autonomic cardiovascular effects. Injection of L-NAME (10 mg/kg, i.v.), but not D-NAME, produced rapid and marked increases (74 +/- 3 mm Hg) in MAP that were sustained for >1 h. In SHRSPs that were treated with the ET(A/B) receptor antagonist, L-754,142 (15 mg/kg + 15 mg/kg/h), L-NAME increased MAP by 45 +/- 4 mm Hg (p < 0.0001 compared with L-NAME alone). L-754,142 blocked pressor responses to big ET-1 by >90% but was without effect on pressor responses to norepinephrine. Plasma levels of ET-1 averaged 5 +/- 1 pg/ml in animals given vehicle and were slightly increased in animals given either L-NAME alone (7 +/- 2 pg/ml) or L-754,142 alone (7 +/- 2 pg/ml) but increased markedly when L-NAME and L-754,142 were given together (114 +/- 18 pg/ml). This may relate to an effect of L-754,142 to block ET-receptor-mediated clearance of ET-1. We conclude that ET plays a role in the short-term pressor response after NOS inhibition in SHRSPs.     

Swyer James syndrome following Mycoplasma pneumoniae pneumonia: report of one case

Systemic vasculopathy in patients with neurofibromatosis type 1 is rare. We describe a case of unusual cerebral and renal involvement in a young, 29-year-old patient, who died of a cerebral ischemic attack one year after our observation.     

Active Wegener's granulomatosis is associated with HLA-DR+ CD4+ T cells exhibiting an unbalanced Th1-type T cell cytokine pattern: reversal with IL-10

Wegener's granulomatosis (WG) is a granulomatous vasculitis that affects the upper respiratory tract, lung, and kidney. Since T cells make up a significant proportion of cells infiltrating granulomatous lesions in WG, we investigated the proliferative response and cytokine profile of T cells from these patients. PBMCs were isolated from 12 patients with active WG, 7 patients with inactive disease, and 12 healthy normal donors. PBMCs from clinically active WG patients exhibited increased proliferation following stimulation with either PMA/ionomycin or anti-CD2 and anti-CD28, when compared with normal donors. In addition, these PBMCs exhibited increased secretion of IFN-gamma, but not of IL-4, IL-5, or IL-10. Furthermore, TNF-alpha production from PBMCs and CD4+ T cells isolated from patients with WG was elevated, when compared with healthy donors. In further studies, we investigated the ability of WG patients' monocytes to produce IL-12 and showed that both inactive and active patients produced increased amounts of IL-12. Finally, the in vitro IFN-gamma production by WG PBMC is inhibited in a dose-dependent manner by exogenous IL-10. These data suggest that T cells from WG patients overproduce IFN-gamma and TNF-alpha, probably due to dysregulated IL-12 secretion, and that IL-10 may therefore have therapeutic implications for this disease.     

Diabetes education on wheels

Diabetes education programs remain underdeveloped in the pediatric setting, resulting in increased consumer complaints and financial liability for hospitals. The Diabetes Education on Wheels program was designed to provide comprehensive, outcome-oriented education for patients with juvenile diabetes. The primary goal of the program was to enhance patients' and family members' ability to achieve self-care in the home setting. The program facilitated sequential learning, improved consumer satisfaction, and promoted financial viability for the hospital.     

The athlete's heart: is this an entity in paediatrics?

A case report of a boy who demonstrates features of an athlete's heart, associated with dilatation of the coronary artery, is presented. The importance of distinguishing this benign condition from pathologic causes such as cardiomyopathy, and risk of sudden death in these athletes is discussed.