Precisely Designed Mesoscopic Titania for High-Volumetric-Density Pseudocapacitance

Author(s):  
Kun Lan ◽  
Lu Liu ◽  
Jun-Ye Zhang ◽  
Ruicong Wang ◽  
Lianhai Zu ◽  
...  
Keyword(s):  
Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2499
Author(s):  
Krzysztof Jastrzębski ◽  
Piotr Kula

The energetic and climate crises should pose a challenge for scientists in finding solutions in the field of renewable, green energy sources. Throughout more than two decades, the search for new opportunities in the energy industry made it possible to observe the potential use of hydrogen as an energy source. One of the greatest challenges faced by scientists for the sake of its use as an energy source is designing safe, usable, reliable, and effective forms of hydrogen storage. Moreover, the manner in which hydrogen is to be stored is closely dependent on the potential use of this source of green energy. In stationary use, the aim is to achieve high volumetric density of the container. However, from the point of view of mobile applications, an extremely important aspect is the storage of hydrogen, using lightweight tanks of relatively high density. That is why, a focus of scientists has been put on the use of carbon-based materials and graphene as a perspective solution in the field of H2 storage. This review focuses on the comparison of different methods for hydrogen storage, mainly based on the carbon-based materials and focuses on efficiently using graphene and its different forms to serve a purpose in the future H2-based economy.


PEDIATRICS ◽  
1993 ◽  
Vol 91 (6) ◽  
pp. 1127-1130
Author(s):  
Antero Kotaniemi ◽  
Anneli Savolainen ◽  
Hannu Kautiainen ◽  
Heikki Kröger

Study objective. To investigate the degree and determinants of osteopenia in juvenile chronic polyarthritis. Design. Retrospective case-control study of central bone mineral density. Setting. Rheumatism Foundation Hospital and Kuopio University Hospital, Finland. Subjects. A sample of 43 girls aged 7 to 19 with juvenile chronic polyarthritis treated with systemic glucocorticoids and a control sample of 44 healthy girls matched for age. Main outcome measures. Bone mineral density and bone size (width) measured by dual-energy x-ray absorptiometry and bone volumetric density calculated as an approximation of true bone density at both the lumbar spine and femoral neck. Results. The girls with juvenile chronic arthritis had reduced bone mineral density, bone size, and bone volumetric density at both the lumbar spine and femoral neck (statistically significant findings, P = .022 for the bone size of the femoral neck and P < .001 for the other parameters). At the spine, the mean bone mineral density was 80%, the mean bone size 89%, and the mean bone volumetric density 89% of the values in the control group. At the femoral neck, the values were 78%, 93%, and 83%, respectively. The groups were matched for age, but the girls with arthritis were smaller and lighter. In the juvenile arthritis group, the femoral bone mineral density and bone volumetric density and the spinal bone width correlated negatively with the mean glucocorticoid dose. Conclusion. Axial bone mineral density is clearly reduced in severe juvenile polyarthritis and is mediated by both decreased bone volumetric density and diminished growth.


2018 ◽  
Vol 33 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Jennifer C Kelley ◽  
Nicolas Stettler-Davis ◽  
Mary B Leonard ◽  
Douglas Hill ◽  
Brian H Wrotniak ◽  
...  

2019 ◽  
Author(s):  
Donald J. Siegel ◽  
◽  
Alauddin Ahmed ◽  
Yiyang Liu ◽  
Adam Matzger ◽  
...  

2021 ◽  
Author(s):  
Joseph Murray

Abstract The mechanism which adapts the T-cell antigen receptor (TCR) within a given major histocompatibility complex (MHC/HLA) genotype is essential for protection against pathogens. Historically attributed to relative affinity, genetically vast TCRs are surprisingly focused towards a micromolar affinity for their respective peptide (p) plus MHC (pMHC) ligands. Thus, the somatic diversity of the TCR with respect to MHC-restriction, and (ultimately) to pathogens, remains enigmatic. Here, we derive a triple integral solution (from fixed geometry) for any given V domain in TCR bound to pMHC. Solved complexes involving HLA-DR and HLA-DQ, where genetic linkage to the TCR is most profound, were examined in detail. Certain V domains displayed rare geometry within this panel—specifying a restricted rotational probability/volumetric density (dV). Remarkably, hydrogen (H) bond charge-relays distinguished these structures from the others; suggesting that CDR3 binding chemistry dictates CDR2 contacts on the opposite MHC-II alpha helix. Together, these data suggest that TCR recapitulate dV and specialise target pMHC recognition, i.e., a dynamics alternative to a relative TCR-affinity based mechanism.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 178 ◽  
Author(s):  
Patrick Schlegel ◽  
Andreas Gutzwiller

Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P–) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P– diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P– reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P– without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.


1993 ◽  
Vol 265 (4) ◽  
pp. E655-E659 ◽  
Author(s):  
I. R. Reid ◽  
M. C. Evans ◽  
G. J. Cooper ◽  
R. W. Ames ◽  
J. Stapleton

We recently established that the dependence of bone mineral density (BMD) on body weight in women is mainly attributable to a close relationship between total body fat mass and BMD. The present study assesses whether this latter relationship might be contributed to by the hormones insulin or amylin, both of which may influence fat mass and calcium metabolism. Fifty-three normal postmenopausal women underwent a 75-g glucose tolerance test with measurement of plasma insulin and amylin concentrations every 30 min for 2 h. Body composition and BMD/height (to provide a quantity with the dimensions of volumetric density that is independent of body size) were measured by dual-energy X-ray absorptiometry, and volumetric density of the third lumbar vertebral body was calculated. Circulating insulin concentrations correlated with BMD/height and volumetric density of the third lumbar vertebral body (r = 0.28-0.52). They also were related to body weight (r = 0.34-0.56) and fat mass (r = 0.38-0.56) but were not independently related to lean mass on multiple regression. There were no consistent relationships between amylin levels and these variables. Multiple-regression analyses with fat mass and insulin levels as independent variables indicated that BMD/height of total body and femoral trochanter were primarily related to fat mass, whereas, in femoral neck, the significant relationship was with insulin. Volumetric density of the third lumbar vertebral body was related to insulin levels alone on this analysis.(ABSTRACT TRUNCATED AT 250 WORDS)


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