From core/shell to hollow Fe/γ-Fe2O3 nanoparticles: evolution of the magnetic behavior.

High quality Fe/γ-Fe2O3 core/shell, core/void/shell, and hollow nanoparticles with two different sizes of 8 and 12 nm were synthesized, and the effect of morphology, surface and finite-size effects on their magnetic properties including the exchange bias (EB) effect were systematically investigated. We find a general trend for both systems that as the morphology changes from core/shell to core/void/shell, the magnetization of the system decays and inter-particle interactions become weaker, while the effective anisotropy and the EB effect increase. The changes are more drastic when the nanoparticles become completely hollow. Noticeably, the morphological change from core/shell to hollow increases the mean blocking temperature for the 12 nm particles but decreases for the 8 nm particles. The low-temperature magnetic behavior of the 12 nm particles changes from a collective super-spin-glass system mediated by dipolar interactions for the core/shell nanoparticles to a frustrated cluster glass-like state for the shell nanograins in the hollow morphology. On the other hand for the 8 nm nanoparticles core/shell and hollow particles the magnetic behavior is more similar, and a conventional spin glass-like transition is obtained at low temperatures. In the case of the hollow nanoparticles, the coupling between the inner and outer spin layers in the shell gives rise to an enhanced EB effect, which increases with increasing shell thickness. This indicates that the morphology of the shell plays a crucial role in this kind of exchange-biased systems.

Genetic divergence for high-molecular weight glutenin subunits (HMW-GS) in indigenous landraces and commercial cultivars of bread wheat of Pakistan.

Wheat flour quality is an important consideration in the breeding and development of new cultivars. A strong association between high-molecular weight glutenin subunits (HMW-GS) and bread making quality has resulted in the widespread utilization of HMW-GS in wheat breeding. In this study, we analyzed 242 lines of wheat, including landraces from the provinces of Punjab and Baluchistan, as well as the commercial varieties of Pakistan, to determine allelic variation in the Glu-A1, Glu-B1, and Glu-D1 loci encoding HMW-GS. Higher genetic diversity was observed for HMW-GS in landraces from Baluchistan, followed by landraces collected from Punjab and then commercial varieties. Rare and uncommon subunits were observed in Glu-B1, whereas Glu-A1 was less polymorphic. However, Glu-B1 was the highest contributor to overall diversity (78%), with a total of 31 rare alleles, followed by Glu-D1 (20%) with the high quality 5+10 allele and other variants. Commercial cultivars possessed favorable alleles, potentially from indirect selection for wheat flour quality by the breeders; however, this indirect selection has decreased the pedigree base of commercial cultivars. The allelic combinations, including 2*, 5+10, and 17+18, showing high quality scores were frequent among landraces, indicating their usefulness in future crop improvement and breeding programs.

Shunt nephritis from Propionibacterium acnes in a solitary kidney.

Since its initial description in 1965, immune complex glomerulonephritis associated with ventriculoatrial shunts (VAS) has been reported widely in the literature. The most common incriminating organism is Staphylococcus epidermidis, but less often, an organism generally regarded as nonpathogenic, such as Propionibacterium acnes, has been noted as the cause. Shunt infection usually occurs within a few months after placement or manipulation of the shunt, and shunt nephritis (SN) develops gradually over months to years after. Treatment involves mandatory removal of the shunt and antibiotics; prognosis is variable. We report a case of SN with P acnes that is unusual because of its occurrence in a solitary kidney 6 years after shunt placement, persistently negative blood cultures, and normal complement levels. Percutaneous biopsy of a solitary kidney should be considered if it is expected that the result may guide therapy of progressive renal failure.

Diagnosis and management of laryngo-pharyngeal reflux.

The aim of the present paper was to analyze laryngo-pharyngeal reflux (LPR) manifestations in ENT patients, and present a diagnostic and treatment algorithm for appropriate management. Retrospective chart review of 150 patients, who had initially presented with symptoms suggestive of LPR. Treatment included the administration of omeprazole 20 mg twice daily for at least 4 weeks. Unresponsive patients were also given metoclopramide 10 mg twice daily for four additional weeks, and the dose of omeprazole was increased to 40 mg twice daily, if they did not achieve complete symptom resolution. Only patients who became completely asymptomatic after LPR treatment were included in the study. As many as 18 % of patients attending an ENT outpatient department benefited from anti-reflux treatment. A need to clear the throat represented the most common symptom, whereas interarytenoid oedema/congestion was the most common finding on flexible naso-endoscopy (62.67 and 72.7 % of patients, respectively). The vast majority of patients responded after 4 weeks of treatment with omeprazole, however, as many as 32 % of LPR patients achieved complete symptom control after the initial 4 week trial period. LPR seems to be more common than previously reported in the literature. Appropriate management of LPR can prevent the symptomatic use of various medical treatments for related manifestations, and even surgical interventions, thus decreasing the overall patient morbidity.