A facile route for 3D aerogels from nanostructured 1D and 2D materials

Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO2, single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS2, graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications.National Science Foundation (U.S.) (award number NSF DMR 0845358)MIT Energy InitiativeDouglas Spreng '65Massachusetts Institute of Technology. Institute for Soldier Nanotechnologie

Growth of superconducting MgB2 thin films via postannealing techniques

We report the effect of annealing on the superconductivity of MgB2 thin films as functions of the postannealing temperature in the range from 700 C to 950 C and of the postannealing time in the range from 30 min to 120 min. On annealing at 900 C for 30 min, we obtained the best-quality MgB2 films with a transition temperature of 39 K and a critical current density of ~ 10^7 A/cm^2. Using the scanning electron microscopy, we also investigated the film growth mechanism. The samples annealed at higher temperatures showed the larger grain sizes, well-aligned crystal structures with preferential orientations along the c-axis, and smooth surface morphologies. However, a longer annealing time prevented the alignment of grains and reduced the superconductivity, indicating a strong interfacial reaction between the substrate and the MgB2 film.Comment: 7 pages, 4 figures include

Effects of an Aging Management Program for Middle-aged Women on Resilience and Successful Aging

PURPOSE: The purpose of this study was to examine the effects of an aging management program on the resilience and successful aging of middle-aged women. METHODS: A quasi-experimental study with a non-equivalent control and pre-post test design was used. The participants were 39 middle-aged women living in urban areas in Korea. The experimental group (n=22) received the aging management program for a total of 10 weeks, 90 minutes to 120 minutes per week. The aging management program consisted of strategies to enhance the behavior, promotion conditions, and habits of the program, including various activities for middle-aged women. The data were analyzed using χ² tests, independent t-tests, and repeated measures analysis of variance with the SPSS/WIN 21.0 program. RESULTS: The resilience score of the experimental group was significantly higher level than the score of the control group in the time-to-group interactions (F=3.70, p=0.029). The successful aging score of the experimental group was significantly higher than the score of the control group in the time-to-group interactions (F=5.86, p=0.004). However, the sub-hypotheses of resilience (self-regulation and interpersonal relationships) and successful aging (physical aging adaptation and psychological age adaptation) were partially accepted. CONCLUSIONS: The aging management program for middle-aged women was identified as an effective intervention for promoting resilience and successful aging in middle-aged women. Therefore, this suggests that the aging care program could be a useful intervention program to improve the mental health of middle-aged women living in communities

Do parenting stress, work-family conflict, and resilience affect retention intention in Korean nurses returning to work after parental leave?: a cross-sectional study

Purpose This study investigated whether parenting stress, work-family conflict, resilience affect retention intent in Korean nurses returning to work after parental leave. Methods The participants in this study were 111 nurses recruited from 10 hospitals in Korea, who were working after formal parental leave from their hospitals. Collected data were analyzed using descriptive statistics, the t-test, analysis of variance, the Mann-Whitney U-test, Pearson correlation coefficients, and hierarchical regression. Results Retention intention (33.80±7.78), parenting stress (101.70±17.57), and resilience (85.02±12.75) were at greater than moderate levels and a midpoint level of work-family conflict (29.63±7.00) was noted in this sample of mostly women nurses in their 30s. The factors affecting retention intent were parental leave duration, the number of times that participants had taken parental leave, health condition, work-family conflict, and resilience. The total explanatory power of these variables was 36.7%. Retention intent had a negative correlation with parenting stress and work-family conflict. Conversely, retention intent was positively correlated with resilience Conclusion This study supports the need for flexible adjustment of returning nurses’ working hours and family-friendly policies to promote balance between work and family. It is also necessary to develop and apply measures that boost resilience and support health improvement for nurses returning to work.As nurses are often assigned to new areas of work upon return, training programs to aid their adjustment may also be helpful

Dietary Intake and Serum Levels of Iron in Relation to Oxidative Stress in Breast Cancer Patients

Iron may induce oxidative stress via production of reactive oxygen species, facilitating mammary carcinogenesis. This study investigated the role of iron in relation to oxidative stress as a potential risk factor in the development of breast cancer (BC). BC patients (n = 121) and healthy age-matched controls (n = 149) were entered into the study. Iron and antioxidant vitamins intakes were estimated using a quantitative food frequency questionnaire. Thirty one subjects from each group provided blood samples for measurement of serum iron, plasma malondialdehyde (MDA) and ferric reducing ability of plasma (FRAP). Total and non-heme iron intake of BC patients were lower than those of the controls. However, the serum iron level was significantly higher in BC patients. Plasma MDA levels were also significantly higher in BC patients whereas no significant difference in FRAP values were observed between the two groups. Log-transformed serum iron concentration showed no significant correlation with MDA or FRAP. These results suggest that serum iron overload may be a breast cancer risk factor possibly due to increased oxidative stress

Characterization of Fabry mice treated with recombinant adeno-associated virus 2/8-mediated gene transfer

<p>Abstract</p> <p>Background</p> <p>Enzyme replacement therapy (ERT) with α-galactosidase A (α-Gal A) is currently the most effective therapeutic strategy for patients with Fabry disease, a lysosomal storage disease. However, ERT has limitations of a short half-life, requirement for frequent administration, and limited efficacy for patients with renal failure. Therefore, we investigated the efficacy of recombinant adeno-associated virus (rAAV) vector-mediated gene therapy for a Fabry disease mouse model and compared it with that of ERT.</p> <p>Methods</p> <p>A pseudotyped rAAV2/8 vector encoding α-Gal A cDNA (rAAV2/8-hAGA) was prepared and injected into 18-week-old male Fabry mice through the tail vein. The α-Gal A expression level and globotriaosylceramide (Gb3) levels in the Fabry mice were examined and compared with Fabry mice with ERT. Immunohistochemical and ultrastructural studies were conducted.</p> <p>Results</p> <p>Treatment of Fabry mice with rAAV2/8-hAGA resulted in the clearance of accumulated Gb3 in tissues such as liver, spleen, kidney, heart, and brain with concomitant elevation of α-Gal A enzyme activity. Enzyme activity was elevated for up to 60 weeks. In addition, expression of the α-Gal A protein was identified in the presence of rAAV2/8-hAGA at 6, 12, and 24 weeks after treatment. α-Gal A activity was significantly higher in the mice treated with rAAV2/8-hAGA than in Fabry mice that received ERT. Along with higher α-Gal A activity in the kidney of the Fabry mice treated with gene therapy, immunohistochemical studies showed more α-Gal A expression in the proximal tubules and glomerulus, and less Gb3 deposition in Fabry mice treated with this gene therapy than in mice given ERT. The α-gal A gene transfer significantly reduced the accumulation of Gb3 in the tubules and podocytes of the kidney. Electron microscopic analysis of the kidneys of Fabry mice also showed that gene therapy was more effective than ERT.</p> <p>Conclusions</p> <p>The rAAV2/8-hAGA mediated α-Gal A gene therapy provided improved efficiency over ERT in the Fabry disease mouse model. Furthermore, rAAV2/8-hAGA-mediated expression showed a greater effect in the kidney than ERT.</p