On the basis of the predictions of statistical-thermodynamic models, it is postulated that excluded volume effects may play a significant role in the stability, interaction, and function of proteins. We studied the effects of confinement on protein un/refolding and stability. Our approach was to encapsulate a model protein, RNase A, in a mesoporous silica, MCM-48, with glasslike wall structure and with well-defined pores to create a crowded microenvironment. To the best of our knowledge, this is the first report where pressure perturbation and differential scanning calorimetric techniques are employed to evaluate the stability, hydration, and volumetric properties of the confined protein. A drastic increase in protein stability ( approximately 30 degrees C increase in unfolding temperature) is observed. The increase in stability is probably not only due to a restriction in conformational space (excluded volume effect due to nonspecific interactions) but also due to an increased strength of hydration of the protein within the narrow silica pores.
Objectives
To identify clinical variables predictive of the risk of thromboembolism (TE), and to confirm the incidence of TE in primary and secondary childhood nephrotic syndrome (NS).
Study design
A comprehensive chart review identified 326 children with NS from any cause evaluated between 1999 and 2006. These patients had a total of 1472.8 patient-years of follow-up. Comparison statistics, survival analysis, and logistic regression were used to define TE epidemiology and clinical risk factors.
Results
We found that 9.2% of our cohort had experienced at least 1 TE. The overall incidence was 20.4 patients with TEs/1000 patient-years. The median time to the first TE was 70.5 days after diagnosis of NS. Deep venous thrombosis was the most common TE (76%) and was frequently associated with the use of a central venous catheter (45%). Significant independent predictors of TE included age ≥ 12 years at onset of NS (P < .0001), severity of proteinuria (P < .0001), and history of TE preceding diagnosis of NS (P < .0001). Life- or limb-threatening TEs represented 23.7% of the events.
Conclusions
Children with NS should be carefully followed for TE, particularly those who are age 12 years or older, have severe proteinuria, or have a previous history of TE.
s Ca 3 M 2 Ge 3 O 12 :Mn 2+ ,Mn 4+ (M = Al, Ga) with sufficient red light component were developed, and their lattice occupancy and luminescent properties of different color centers have been studied. In Ca 3 M 2 Ge 3 O 12 :Mn, the abnormal self-reduction of Mn 4+ to Mn 2+ occurs. The doped manganese ion (using MnO 2 as Mn source) occupies dodecahedron Ca 2+ site forming Mn 2+ (I) color center with orange emission, while it occupies octahedral Al 3+ /Ga 3+ site forming Mn 2+ (II) and Mn 4+ color centers with red and deep red light emission. The thermal quenching properties show that Ca 3 M 2 Ge 3 O 12 :Mn (M = Al, Ga) samples have low thermal quenching, and the thermal quenching of Mn 2+ (I) is lower than that of Mn 2+ (II) due to existence of more defects nearby the Mn 2+ (II) providing additional nonradiative recombination decay path. Ca 3 Al 2 Ge 3 O 12 :Mn has a lower thermal quenching than Ca 3 Ga 2 Ge 3 O 12 :Mn because the former possesses higher rigidity. The obtained results reveal that Ca 3 M 2 Ge 3 O 12 :Mn 2+ ,Mn 4+ (M = Al, Ga) has potential practical value in WLEDs. Moreover, the luminescence of Mn 2+ and Mn 4+ ions in a matrix provides a new strategy for designing and synthesizing new luminescent materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.