Activated carbons were prepared from pecan shell by phosphoric acid activation. The pore structure and acidic surface groups of these carbons were characterized by nitrogen adsorption, Boehm ...titration and transmittance Fourier infrared spectroscopy (FTIR) techniques. The characterization results demonstrated that the development of pore structure was apparent at temperatures ⩾250
°C, and reached 1130
m
2/g and 0.34
cm
3/g, respectively, at 500
°C. Impregnation ratio and soaking time at activation temperature also affected the pore development and pore size distribution of final carbon products. At an impregnation ratio of 1.5, activated carbon with BET surface area and micropore volume as high as 861
m
2/g and 0.289
cm
3/g was obtained at 400
°C. Microporous activated carbons were obtained in this study. Low impregnation ratio (less than 1.5) and activation temperature (less than 300
°C) are favorable to the formation of acidic surface functional groups, which consist of temperature-sensitive (unstable at high temperature) and temperature-insensitive (stable at high temperature) two parts. The disappearance of temperature-sensitive groups was significant at temperature ⩾300
°C; while the temperature-insensitive groups are stable even at 500
°C. FTIR results showed that the temperature-insensitive part was mostly phosphorus-containing groups as well as some carbonyl-containing groups, while carbonyl-containing groups were the main contributor of temperature-sensitive part.
Activated carbons were prepared from rice hull by one-step phosphoric acid activation in this work. The evolution of pore structure and surface chemistry in the activation temperature range of ...170–450
°C was investigated through various characterization techniques. The results showed that the development of porosity (extent of activation) was negligible at activation temperature below 300
°C, and rapid evolution occurred in 300–400
°C. Porous activated carbon with bimodel pore structure (pore
<
1
nm and pore
>
1
nm) and BET surface area as high as 1295
m
2/g was obtained at 450
°C. The ash contents of samples prepared in this study were in the range of 5–21%. The ash contents of carbons prepared in this study initially decreased from 21.03% to 4.89% with the change of temperature from 170 to 300
°C, then increased to 8.72% at 450
°C. Boehm titration results suggested that low activation temperature (⩽300
°C) benefits the formation of acidic surface groups. With the increase of activation temperature from 300 to 350
°C, the concentrations of strong, intermediate and weak acidic surface groups decreased from 2.23, 1.87, and 2.73 to 1.66, 1.32, and 2.16
mmol
H
+/g, respectively. Over 350
°C, the change of these groups were insignificant. FTIR results revealed the existence of carbonyl-containing, phosphorus-containing groups, and groups containing Si–O bond. The relative concentration of carbonyl-containing groups decreases with an increase in activation temperature, while that of phosphorus-containing groups follows the reverse trend. The content of Si–O decreased first, then slowly increased with the increase of activation temperature. Boehm titration and FTIR (Fourier transform infrared spectroscopy) results indicated that the surfaces of these carbons contain both temperature-sensitive and temperature-insensitive groups. The temperature-sensitive part consists mainly of carbonyl-containing groups, such as carboxylic groups, while the temperature-insensitive part is primarily phosphorus-containing groups and groups containing Si–O bond. This study demonstrated that carbon products with relative low ash content and high activation degree can be prepared from rice hull by H
3PO
4 activation at suitable temperature.
The Ca2+-selective epithelial channel TRPV5 plays a significant role in renal calcium reabsorption and improving osteoporosis (OP). In this study, we investigated the mechanisms of yak milk on ...osteoporosis mice in TRPV5-mediated Ca2+ reabsorption in the kidney. We observed that treatment of OP mice with yak milk reconstructed bone homeostasis demonstrated by increasing the levels of OPG as well as decreasing the levels of TRAP and ALP in serum. Additionally, yak milk reduced the level of parathyroid hormone (PTH) and elevated 1,25-(OH)2D3 and calcitonin (CT), and inhibited the excretion of Ca/Cr and Pi/Cr in OP mice, which explained by regulating hormone levels and thus enhance the renal Ca2+ reabsorption. Further analysis exhibited that yak milk upregulated the expression of TRPV5 protein and mRNA as well as calbindin-D28k in OP mice kidneys. Overall, these outcomes demonstrate that yak milk enhances renal Ca2+ reabsorption through the TRPV5 pathway synergistically with calbindin-D28k, thus ameliorating OP mice. This provides a new perspective for yak milk as a nutritional supplement to prevent osteoporosis.
Little is known of the genetic architecture of cancer at the subclonal and single-cell level or in the cells responsible for cancer clone maintenance and propagation. Here we have examined this issue ...in childhood acute lymphoblastic leukaemia in which the ETV6-RUNX1 gene fusion is an early or initiating genetic lesion followed by a modest number of recurrent or 'driver' copy number alterations. By multiplexing fluorescence in situ hybridization probes for these mutations, up to eight genetic abnormalities can be detected in single cells, a genetic signature of subclones identified and a composite picture of subclonal architecture and putative ancestral trees assembled. Subclones in acute lymphoblastic leukaemia have variegated genetics and complex, nonlinear or branching evolutionary histories. Copy number alterations are independently and reiteratively acquired in subclones of individual patients, and in no preferential order. Clonal architecture is dynamic and is subject to change in the lead-up to a diagnosis and in relapse. Leukaemia propagating cells, assayed by serial transplantation in NOD/SCID IL2Rγ(null) mice, are also genetically variegated, mirroring subclonal patterns, and vary in competitive regenerative capacity in vivo. These data have implications for cancer genomics and for the targeted therapy of cancer.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Along with the continuous urbanization process, massive riparian buffers are developed to satisfy the increasing demands for flood protection and economic growth. Such changes of land use types and ...landscape patterns pose a significant challenge to the protection of the eco-system of urban rivers. This research concentrates on revealing the potential relation between the water quality of the urban river and land characteristics including land use types and landscape patterns of the riparian area and discusses if the relationship varies with spatial scales. The study area of this research are the 800 m riparian buffer of the six river water quality monitoring sections along Huangpu River. Based on the long-term monthly collection data of six monitoring points in Huangpu River, Shanghai, China, and the land use data of 100 m downstream of 1 km upstream of the monitoring point. Using landscape indicators, GIS spatial analysis, and statistical methods, the responses of land use and landscape patterns to water quality in different scales are obtained. Results show that: (1) Urban Land (UL) and Agricultural Land (AL) have an enormous negative contribution to each buffer, which is the primary non-point source pollution and influencing factor. (2) The active contribution of Wetland (WL) and Forestry Land (FL) is the most significant in the small range buffer of 0–200 m. (3) The negative effect of Industrial Land (IL) on water quality is only significant in the small buffer. (4) The effect of landscape pattern on water quality is more significant on the large spatial scale than the small scale. At the same time, this paper extends the conclusion to discuss the land use of the 800 m buffer zone of Huang River by using point to the area, proving that the research result is helpful for the political decision of urban management and provides suggestions for the land optimization of riparian buffers.
In our study, the effects of water stress on photosynthesis and photosynthetic electron transport chain (PETC) were studied through several ways including monitoring the change of gas exchange ...parameters, modulated chlorophyll fluorescence, rapid fluorescence induction kinetics, reactive oxygen species, antioxidant enzymes activities and D1 protein in apple leaves. Our results showed when the leaf water potential (
) was above -1.5MPa, the stomatal limitation should be the main reason for the drop of photosynthesis. In this period,
,
,
, and
all showed a strong positive correlation with leaf water potential. So do modulated chlorophyll fluorescence parameters related to photosynthetic biochemistry activity including F
/F
, Φ
, q
, and q
as water leaf potential gradually decreased. On the contrary, in this period, NPQ and
kept going up, which expresses an attempt to dissipate excess energy to avoid its damage to plants. When
is below -1.5MPa,
continued to decrease linearly while
increased and a 'V' model presented the correlation between
and
by polynomial regression. It implied in this period the drop in photosynthesis activity might be caused by non-stomatal limitation other than stomatal limitation. F
/F
, Φ
, qP, and qL in apple leaves treated with water stress were much lower than that in control while NPQ and
started to go down. It demonstrated the excess energy might exceed the tolerant ability of apple leaves. Consistent with changes of these parameters, excess energy led to an increase in the production of reactive oxygen species (ROS) including H
O
and O
Although the activities of antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) increased dramatically and ascorbate peroxidase (APX) decreased in apple leaves with drought stress, it was not still sufficient to scavenge ROS. Consequently, the accumulation of ROS triggered a reduction of D1 protein net content, a core protein in PSII reaction center. As D1 was responsible for the photosynthetic electron transport from Q
to Q
, the capacity of PETC between Q
to Q
was considerably down-regulated. The decline of photosynthesis and activity of PETC might result in the shortage of ATP and limitation the regeneration of RuBP (
), a key enzyme in CO
assimilation. They were all non-stomatal factors and together contributed to the decreased CO
assimilation under severe water stress.
Mental health problems have become a public health problem that needs to be solved in China. However, medical resources for mental healthcare remain insufficient and unevenly distributed. The Chinese ...central government has taken many measures to address this issue over the last decade. This study aimed to evaluate the changes in equity in mental health bed allocation from 2011 to 2020.
The data of this study came from the China Health Statistical Yearbook (2012-2021) and the China National Administrative Division Information Platform. The annual growth rate was used to evaluate the time trends of mental health beds. The Lorenz curve, Gini coefficient and Theil index were used to assess equity in the demographic and geographical dimensions. The distribution of mental health beds was visualized on a map using geographic information system (GIS) software.
The total number of mental health beds in China increased steadily from 2011 to 2020. At the national level, the Gini coefficient and Theil index all exhibited downward trends over time. The mental health bed allocation in terms of the demographic dimension was relatively equitable, with Gini values all less than 0.3; however, the Gini coefficients by geographical area were all more than 0.6, indicating inequity. Intraregional contribution rates were higher than interregional contribution rates, which were all above 60%.
The overall distribution equity of mental health beds improved from 2011 to 2020. The equity of mental health beds in terms of population size is superior to that in terms of geographical area. Intraregional differences are the main source of inequity. In particular, differences within the western region need to be given attention. Thus, the findings from this study emphasize that the demographic and geographical distributions and all influencing factors should be considered when the government makes mental health resource allocation policies.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
The fabrication of one-dimensional (1D) magnetic systems on solid surfaces, although of high fundamental interest, has yet to be achieved for a crossover between two-dimensional (2D) ...magnetic layers and their associated 1D spin chain systems. In this study, we report the fabrication of 1D single-unit-cell-width CrCl
3
atomic wires and their stacked few-wire arrays on the surface of a van der Waals (vdW) superconductor NbSe
2
. Scanning tunneling microscopy/spectroscopy and first-principles calculations jointly revealed that the single wire shows an antiferromagnetic large-bandgap semiconducting state in an unexplored structure different from the well-known 2D CrCl
3
phase. Competition among the total energies and nanostructure-substrate interfacial interactions of these two phases result in the appearance of the 1D phase. This phase was transformable to the 2D phase either prior to or after the growth for in situ or ex situ manipulations, in which the electronic interactions at the vdW interface play a nontrivial role that could regulate the dimensionality conversion and structural transformation between the 1D-2D CrCl
3
phases.
Sugar plays an important role in apple fruit development, appearance and quality as well as contributing to a plant's water stress response. Trehalose and the trehalose biosynthetic metabolic ...pathways are part of the sugar signaling system in plants, which are important regulator of water stress response in apple. The effect of water stress treatments applied to apple trees and the corresponding effects of ABA on developmental fruit quality were examined for indicators of fruit quality during fruit development. The results indicated that the severe water stress treatment (W2) occurring after the last stage of fruit cell division caused a decrease in the color and size of fruit. The moderate water stress (W1) occurring after the last stage of fruit cell enlargement (S2) caused an increase in the content of fructose and sorbitol while the apple fruit shape was not affected. These changes in sugar are related to the activity of sugar metabolic enzymes. While the enzymatic activity of vacuolar acid invertase (vAINV) was higher, that of sucrose-phosphate synthase (SPS) was lower in water stress treated fruit throughout the developmental period. This indicates that enhanced sucrose degradation and reduced sucrose synthesis leads to an overall reduced sucrose content during times of drought. Thus, water stress reduced sucrose content. Whereas the content of endogenous trehalose and ABA were the highest in water stress treated fruit. A moderate water stress (W1) imposed on apple trees via water restriction (60%–65% of field capacity) after the fruit cell enlargement phase of fruit development yielded sweeter fruit of higher economic value.
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