Search

Purpose: This study aimed to identify the relationship and mechanism between skeletal muscle peroxisome proliferator–activated receptor β/δ (PPARβ/δ) and spontaneous hypertension. Methods: Rats were divided into four groups (n = 10): spontaneous hypertensive rats exercise group (SHR-E), spontaneous hypertensive rats sedentary group (SHR-S), Wistar-Kyoto control rats exercise group (WKY-E), and Wistar-Kyoto control rats sedentary group (WKY-S). Although the sedentary groups were placed on the treadmill without moving during the training sessions, the exercise groups were forced to run on a treadmill for 8 wk, 1 h·d−1, 5 d·wk−1. After training, the density and area of gastrocnemius microvessels were observed. PPARβ/δ, vascular endothelial growth factor A (VEGFA), superoxide dismutase 2 (SOD-2), and nitric oxide synthase in gastrocnemius were measured by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot. Results: Except the sixth week of age, the systolic blood pressure of SHR-S was significantly higher than that of WKY-S at all time periods. Exercise significantly reduced systolic blood pressure in SHR rats. Compared with the SHR-S group, the WKY-S group had significantly higher PPARβ/δ protein level and density of skeletal muscle microvessels. Eight weeks of exercise increased the PPARβ/δ, SOD-2, VEGFA, and microvessel density and area in the skeletal muscle of SHR. Conclusions: Exercise training promoted PPARβ/δ mRNA and protein-level expression of PPARβ/δ, SOD-2 and VEGFA in skeletal muscle, thus increasing the density and area of skeletal muscle blood vessels. These regulations contribute to the reduction of peripheral vascular resistance. This may be a potential mechanism of exercise to reduce blood pressure. [ABSTRACT FROM AUTHOR]

Visual illusions have fascinated mankind since antiquity, as they provide a unique window to explore the constructive nature of human perception. The Pinna illusion is a striking example of rotation perception in the absence of real physical motion. Upon approaching or receding from the Pinna-Brelstaff figure, the observer experiences vivid illusory counter rotation of the two rings in the figure. Although this phenomenon is well known as an example of integration from local cues to a global percept, the visual areas mediating the illusory rotary perception in the human brain have not yet been identified. In the current study we investigated which cortical area in the human brain initially mediates the Pinna illusion, using psychophysical tests and functional magnetic resonance imaging (fMRI) of visual cortices V1, V2, V3, V3A, V4, and hMT+ of the dorsal and ventral visual pathways. We found that both the Pinna-Brelstaff figure (illusory rotation) and a matched physical rotation control stimulus predominantly activated subarea MST in hMT+ with a similar response intensity. Our results thus provide neural evidence showing that illusory rotation is initiated in human MST rather than MT as if it were physical rotary motion. The findings imply that illusory rotation in the Pinna illusion is mediated by rotation-sensitive neurons that normally encode physical rotation in human MST, both of which may rely on a cascade of similar integrative processes from earlier visual areas. Hum Brain Mapp 37:2097-2113, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Vanishing white matter (VWM) disease, inherited in an autosomal recessive manner, is one of the most prevalent inherited leukoencephalopathies in childhood. It is a hereditary human disease resulting from the direct defects during protein synthesis, with the gene defects in EIF2B1–5 (identified in 2001–2002) encoding the five subunits of eukaryotic translation initiation factor (eIF2B α, β, γ, δ and ɛ), respectively. Most of the published studies were carried out in the white population. The analysis of clinical features and EIF2B mutation screening were performed in 11 Chinese patients for the first time. Mutations were identified exclusively in EIF2B5 and EIF2B3 in these patients, with six novel mutations, including five missense mutations (EIF2B5: c.185A>T, p.D62V; c.1004G>C, p.C335S; c.1126A>G, p.N376D; EIF2B3: c.140G>A, p.G47E; c.1037T>C, p.I346T) and one deletion leading to amino-acid deletion (EIF2B5: c.1827–1838del, p.S610–D613del). EIF2B3 mutation, accounting for 20% of the total number of mutations found in this study, is more prevalent than expected according to an earlier report (7%). A hot spot mutation in EIF2B3 was identified in this study. A unique EIF2B mutation spectrum in Chinese VWM patients was shown. A systemic study to assess mutation spectrum in different populations needs to be carried out.Journal of Human Genetics (2009) 54, 74–77; doi:10.1038/jhg.2008.10; published online 16 January 2009 [ABSTRACT FROM AUTHOR]

The effects of rainfall intensity on stemflow production as described in the literature are quite inconsistent (increase, decrease, or no clear relationship) due to complex interactions between rainfall characteristics, and the effect of raindrop size on stemflow production has rarely been explored. Here we conducted field rainfall simulation experiments on two dominant xerophytic shrubs (Caragana korshinskii and Artemisia ordosica) in northwesten China to quantitatively examine the relationship between rainfall intensity and stemflow production, and to test whether larger raindrops result in a decrease in stemflow production. We found that (1) stemflow production increased with rainfall intensity until reaching a threshold value and then began to decrease, and (2) stemflow showed a significant (P <.01) linear decrease with increasing raindrop size. Our study is useful to reconcile the disputed relationships between rainfall intensity and stemflow production, and provides a basis for a quantitative evaluation to fill the knowledge gap regarding how raindrop size determines stemflow production. [ABSTRACT FROM AUTHOR]

Aim: Stemflow has been increasingly recognized as an indispensable component in water and nutrient budgets within vegetated ecosystems. Here we aim to quantify the stemflow percentage (St, %) of incident precipitation (i.e. stemflow production) at a global scale, and to provide a systematic evaluation on how biotic and abiotic factors affect St. Location: Global. Time period: 1970–2019. Major taxa studied: Woody plants (trees and shrubs). Methods: We compiled a global stemflow dataset from 234 peer‐reviewed papers, which included 488 observations of St and the related biotic (stand characteristics) and abiotic factors (climate variables) at 283 sites within terrestrial woody plant ecosystems. We explored the global pattern of St and performed a machine learning method (boosted regression trees) to model the effects of biotic and abiotic variables on St. Results: Globally, the median (interquartile range, IQR) St was 2.7% (1.0–6.3%). We found that St in arid zones (type B in the Köppen‐Geiger climate classification) was significantly higher (p <.01) than in other climate types, and we also detected a significant difference (p <.01) in St between trees (median: 2.4%; IQR: 1.0–5.3%) and shrubs (median: 7.2%; IQR: 5.2–11.9%). Predictor variables that substantially accounted for the explained deviance of the final model included vegetation height (27.0%), mean annual precipitation (16.1%), mean annual temperature (14.4%), stand density (10.8%), stand age (8.9%) and bark type (5.5%). In contrast, leaf area index, diameter at breast height, basal area, phenology type, life‐form and leaf type were classified as low importance. Main conclusions: Our synthesis provides a cross‐site comparison of St, and gives a holistic view on how climate variables and stand characteristics contribute to and affect global stemflow production. [ABSTRACT FROM AUTHOR]

Monodisperse undoped and Ln3+ (Ln = Eu, Tb) doped Vernier Lu5O4F7 nanorods (denoted as V-LuOF) were synthesized via a facile two-step hydrothermal method followed by heat treatment for the first time. The phases, morphologies, sizes and photoluminescence properties of the as-prepared samples were investigated in detail. Under ultraviolet excitation, the V-LuOF:Ln3+ (Ln = Eu, Tb) nanorods showed their characteristic f–f emissions and also showed red and green emissions, respectively. Moreover, by co-doping Tb3+ and Eu3+ ions into the V-LuOF host and tuning their relative concentration ratio, multicolor tunable emissions have been achieved under 378 nm excitation. This result indicates that V-LuOF nanorods have potential applications in field-emission displays. [ABSTRACT FROM AUTHOR]

The application of NIR‐II emitters for gastrointestinal (GI) tract imaging remains challenging due to fluorescence quenching in the digestive microenvironment. Herein, we report that red‐shifting of the fluorescence emission of Au nanoclusters (AuNCs) into NIR‐II region with improved quantum yields (QY) could be achieved by engineering a protein corona structure consisting of a ribonuclease‐A (RNase‐A) on the particle surfaces. RNase‐A‐encapsulated AuNCs (RNase‐A@AuNCs) displayed emissions at 1050 nm with a 1.9 % QY. Compared to rare earth and silver‐based NIR‐II emitters, RNase‐A@AuNCs had excellent biocompatibility, showing >50‐fold higher sensitivity in GI tract, and migrated homogenously during gastrointestinal peristalsis to allow visualization of the detailed structures of the GI tract. RNase‐A@AuNCs could successfully examine intestinal tumor mice from healthy mice, indicating a potential utility for early diagnosis of intestinal tumors. [ABSTRACT FROM AUTHOR]

The application of NIR‐II emitters for gastrointestinal (GI) tract imaging remains challenging due to fluorescence quenching in the digestive microenvironment. Herein, we report that red‐shifting of the fluorescence emission of Au nanoclusters (AuNCs) into NIR‐II region with improved quantum yields (QY) could be achieved by engineering a protein corona structure consisting of a ribonuclease‐A (RNase‐A) on the particle surfaces. RNase‐A‐encapsulated AuNCs (RNase‐A@AuNCs) displayed emissions at 1050 nm with a 1.9 % QY. Compared to rare earth and silver‐based NIR‐II emitters, RNase‐A@AuNCs had excellent biocompatibility, showing >50‐fold higher sensitivity in GI tract, and migrated homogenously during gastrointestinal peristalsis to allow visualization of the detailed structures of the GI tract. RNase‐A@AuNCs could successfully examine intestinal tumor mice from healthy mice, indicating a potential utility for early diagnosis of intestinal tumors. [ABSTRACT FROM AUTHOR]

The application of NIR‐II emitters for gastrointestinal (GI) tract imaging remains challenging due to fluorescence quenching in the digestive microenvironment. Herein, we report that red‐shifting of the fluorescence emission of Au nanoclusters (AuNCs) into NIR‐II region with improved quantum yields (QY) could be achieved by engineering a protein corona structure consisting of a ribonuclease‐A (RNase‐A) on the particle surfaces. RNase‐A‐encapsulated AuNCs (RNase‐A@AuNCs) displayed emissions at 1050 nm with a 1.9 % QY. Compared to rare earth and silver‐based NIR‐II emitters, RNase‐A@AuNCs had excellent biocompatibility, showing >50‐fold higher sensitivity in GI tract, and migrated homogenously during gastrointestinal peristalsis to allow visualization of the detailed structures of the GI tract. RNase‐A@AuNCs could successfully examine intestinal tumor mice from healthy mice, indicating a potential utility for early diagnosis of intestinal tumors. [ABSTRACT FROM AUTHOR]

While dehydrogenases play crucial roles in tricarboxylic acid (TCA) cycle of cell metabolism, which are extensively explored for biomedical and chemical engineering uses, it is a big challenge to overcome the shortcomings (low stability and high costs) of recombinant dehydrogenases. Herein, it is shown that two‐dimensional (2D) SnSe is capable of mimicking native dehydrogenases to efficiently catalyze hydrogen transfer from 1‐(R)‐2‐(R′)‐ethanol groups. In contrary to susceptible native dehydrogenases, lactic dehydrogenase (LDH) for instance, SnSe is extremely tolerant to reaction condition changes (pH, temperature, and organic solvents) and displays extraordinary reusable capability. Structure–activity analysis indicates that the single‐atom structure, Sn vacancy, and hydrogen binding affinity of SnSe may be responsible for their catalytic activity. Overall, this is the first report of a 2D SnSe nanozyme to mimic key dehydrogenases in cell metabolism. [ABSTRACT FROM AUTHOR]

While dehydrogenases play crucial roles in tricarboxylic acid (TCA) cycle of cell metabolism, which are extensively explored for biomedical and chemical engineering uses, it is a big challenge to overcome the shortcomings (low stability and high costs) of recombinant dehydrogenases. Herein, it is shown that two‐dimensional (2D) SnSe is capable of mimicking native dehydrogenases to efficiently catalyze hydrogen transfer from 1‐(R)‐2‐(R′)‐ethanol groups. In contrary to susceptible native dehydrogenases, lactic dehydrogenase (LDH) for instance, SnSe is extremely tolerant to reaction condition changes (pH, temperature, and organic solvents) and displays extraordinary reusable capability. Structure–activity analysis indicates that the single‐atom structure, Sn vacancy, and hydrogen binding affinity of SnSe may be responsible for their catalytic activity. Overall, this is the first report of a 2D SnSe nanozyme to mimic key dehydrogenases in cell metabolism. [ABSTRACT FROM AUTHOR]

Incubated biocrusts is a promising biotechnology for restoring biocrusts and for improving soil health in dryland environments. However, it is challenging to use this method to restore biocrusts on a large-scale, because sand dunes have a complex morphology, and the angle of their varying slopes can expose biocrusts to wind speeds that delay or even prevent their development. In this study, we investigated how micro-topography, i.e. steepness of a sand dune's slope, affects cyanobacteria communities that incubate and restore biocrusts. We covered four different portions of a sand dune (which ranged between 2.3° and 31.3° of slope) with fine-soil substrate in the Tengger Desert, China, and then measured the cyanobacteria's colonization, development, and composition over three years as they formed biocrusts. The cyanobacteria successfully formed biocrusts on all sand dune slopes, and the greatest coverage (36.40 %), thickness (2.70 mm), biomass (22.38 μg cm−2), and exopolysaccharide content (EPS, 306.49 μg cm−2) occurred at the lowest degree of slope (2.3°–5.6°, dune-lowland), whereas the minimum coverage (4.90 %), thickness (1.62 mm), biomass (8.45 μg cm−2), and EPS (160.89 μg cm−2) occurred at the steepest degree of slope (25.3°–31.3°, dune-crest). These plots involved 20 genera of cyanobacteria, and Phormidium was the dominant genus, occupying >65 % of the species composition across all slope treatments. The steepness of a sand dune significantly and negatively influenced the biocrusts' coverage, thickness, chlorophyll a , and EPS (p < 0.05). Steepness was also negatively related to Phormidium (p < 0.05), but positively related to Crinalium , Sericytochromatia (p < 0.05), Chloroplast , and CENA359 (p < 0.10) genera. Our study demonstrated that covering sand with a fine-soil substrate can lead to the successful incubation of biocrusts. Further, the importance of the degree of sand dune slope demands further study to ensure maximum biocrusts restoration at a large scale. It will also be necessary to use a variety of cyanobacteria species in these future studies to achieve a broader knowledge of community functionality. • Sand dune steepness significantly influenced development of incubated biocrusts and composition of cyanobacteria; • Cyanobacteria from Phormidium is more suitable for different dune habitat; • Covering sand with fine-soil substrate is a feasible approach to create incubate and restore biocrusts at a large scale. [ABSTRACT FROM AUTHOR]

Although Fe 3 O 4 has low cost and high theoretical capacity, its low electrical conductivity and significant volume changes during the reaction process result in poor electrochemical performance, particularly cycling performance, which limit its application as anode materials. To overcome these limitations, this study created Fe 3 O 4 @3D cellular carbon composites (Fe 3 O 4 @3D cellular carbon: Fe 3 O 4 @3D-CC) by homogeneously embedding ultrafine Fe 3 O 4 nanoparticles of size around 10 nm in a three-dimensional cellular carbon skeleton using a template-assisted method. The porous structure enables for large volumes of electrolyte to be stored and features a dual continuous transport channel for ions and electrons, which can considerably improve the conductivity of the Fe 3 O 4. Furthermore, 3D cellular carbon locks Fe 3 O 4 nanoparticles, allowing them to adapt to volume changes during charge-discharge process and preventing structural degradation. Due to the aforementioned structural properties, this material has a first discharge-specific capacity of 2534 mA h g−1 at a rate of 0.1 C and can still reach 1011 mA h g−1 after 400 cycles at a high rate of 2 C. This keeps the theoretical capacity at 109 % and distinctly enhances the electrochemical performance of Fe 3 O 4 , particularly the cycling performance. [Display omitted] • Fe 3 O 4 @3D-CC has ion-electron transport channels. • The Fe 3 O 4 nanoparticles have a particle size of 10 nm. [ABSTRACT FROM AUTHOR]

Visual scenes can be readily decomposed into a variety of oriented components, the processing of which is vital for object segregation and recognition. In primate V1 and V2, most neurons have small spatio-temporal receptive fields responding selectively to oriented luminance contours (first order), while only a subgroup of neurons signal non-luminance defined contours (second order). So how is the orientation of second-order contours represented at the population level in macaque V1 and V2? Here we compared the population responses in macaque V1 and V2 to two types of second-order contour stimuli generated either by modulation of contrast or phase reversal with those to first-order contour stimuli. Using intrinsic signal optical imaging, we found that the orientation of second-order contour stimuli was represented invariantly in the orientation columns of both macaque V1 and V2. A physiologically constrained spatio-temporal energy model of V1 and V2 neuronal populations could reproduce all the recorded population responses. These findings suggest that, at the population level, the primate early visual system processes the orientation of second-order contours initially through a linear spatio-temporal filter mechanism. Our results of population responses to different second-order contour stimuli support the idea that the orientation maps in primate V1 and V2 can be described as a spatial-temporal energy map. [ABSTRACT FROM AUTHOR]

Fe 2 O 3 are attractive anode materials for lithium-ion batteries because of their large theoretical capacity and low cost. However, due to their low conductivity, large volume variation and unstable solid electrolyte interface (SEI), their cycling stability is poor. Herein, we developed a simple and general strategy to address these issues. The well-designed yolk-shell Fe 2 O 3 @C nanospheres with the inner Fe 2 O 3 nanoparticles are protected by highly-graphitized and interconnected carbon shells prepared by oxidizing commercial acetylene black. The obtained yolk-shell Fe 2 O 3 @C nanospheres provide sufficient interior void to buffer the volumetric variation of the inner Fe 2 O 3 nanoparticles during cycling. Furthermore, the highly-graphitized and perforated mesoporous carbon shells facilitate fast electron transfer and ions transportation during the charge/discharge process. Benefiting from these structural advantages, the yolk-shell Fe 2 O 3 @C nanospheres provide good cyclic stability which still retain 929 mAh g−1 after 200 cycles at the current density of 0.1 A g−1 and elevate Li + diffusion coefficient from 3.867 × 10−13 to 6.321 × 10−11 m2 s−1. This work provides a new perspective to design the yolk-shell metal oxides@C framework for exploring the high-performance Li-ion batteries. [Display omitted] • Acetylene blacks was constructed into hollow carbon nanospheres. • Unique chain structure and high graphitization degree of carbon shell provides an effective conductive network. • The obtained yolk-shell Fe 2 O 3 @C nanospheres provide sufficient interior void to buffer the volumetric variation of the inner Fe 2 O 3 nanoparticles during cycling. • Fe 2 O 3 @C still retain 929 mAh g−1 after 200 cycles and the Li + diffusion coefficient goes from 3.867 × 10−13 to 6.321 × 10−11 m2 s−1. [ABSTRACT FROM AUTHOR]

Abstract: As a key component of desert ecosystems, biological soil crusts (BSCs) play an important role in dune fixation and maintaining soil biota. Soil microbial properties associated with the colonization and development of BSCs may indicate soil quality changes, particularly following dune stabilization. However, very little is known about the influence of BSCs on soil microbes in sand dunes. We examined the influence of BSCs on soil microbial biomass and community composition in revegetated areas of the Tengger Desert. BSCs increased soil microbial biomass (biomass C and N), microbial phospholipid fatty acid (PLFA) concentrations and the ratio of fungal to bacterial PLFAs. The effects varied with crust type and crust age. Moss crusts had higher microbial biomass and microbial PLFA concentrations than cyanobacteria-lichen crusts. Crust age was positively correlated with microbial biomass C and N, microbial PLFA concentrations, bacterial PLFA concentrations, fungal PLFA concentrations and the ratio of fungal to bacterial PLFAs. BSCs significantly affected microbial biomass C and N in the 0–20cm soil layers, showing a significant negative correlation with soil depth. The study demonstrated that the colonization and development of BSCs was beneficial for soil microbial properties and soil quality in the revegetated areas. This can be attributed to BSCs increasing topsoil thickness after dunes have been stabilized, creating suitable habitats and providing an essential food source for soil microbes. [Copyright &y& Elsevier]

Vanishing white matter disease (VWM) is the first human hereditary disease known to be caused by defects in initiation of protein synthesis. Gene defects in each of the five subunits of eukaryotic translation initiation factor 2B (eIF2B α-ɛ) are responsible for the disease, although the mechanism of the pathogenesis is not well understood. In our previous study, four novel eIF2Bɛ mutations were found in Chinese patients: p.Asp62Val, p.Cys335Ser, p.Asn376Asp and p.Ser610-Asp613del. Functional analysis was performed on these mutations and the recently reported p.Arg269X. Our data showed that all resulted in a decrease in the guanine nucleotide exchange (GEF) activity of the eIF2B complex. p.Arg269X and p.Ser610-Asp613del mutants displayed the lowest activity, followed by p.Cys335Ser, p.Asn376Asp and p.Asp62Val. p.Arg269X and p.Ser610-Asp613del could not produce stable eIF2Bɛ, leading to almost complete loss-of-function. No evidence was obtained for the three missense mutations in changes in eIF2Bɛ protein level or eIF2BɛSer540 phosphorylation, and disruption of holocomplex assembly, or binding to eIF2. All patients in our study had the classical phenotype. p.Asp62Val and p.Asn376Asp mutations caused only mildly decreased GEF activity, were probably responsible for relatively mild phenotype in cases of classical VWM. [ABSTRACT FROM AUTHOR]

Keywords: biocatalysts; density functional calculations; hydrogen evolution; nanozymes; structure-activity relationship EN biocatalysts density functional calculations hydrogen evolution nanozymes structure-activity relationship 11021 11021 1 05/06/21 20210510 NES 210510 The authors would like to draw attention to an error in Figure 2 A of this Research Article. Ultrafiltration membrane was used to separate SnSe nanosheets and LDH at each cycle of LA dehydrogenation reaction by LDH assay kit containing 20 mm LA and 50 mg mL-1 NAD+. Biocatalysts, density functional calculations, hydrogen evolution, nanozymes, structure-activity relationship. [Extracted from the article]

Keywords: Biokatalyse; DFT-Rechnungen; Wasserstoffentwicklung; Nanozyme; Struktur-Aktivitäts-Beziehungen EN Biokatalyse DFT-Rechnungen Wasserstoffentwicklung Nanozyme Struktur-Aktivitäts-Beziehungen 11120 11120 1 05/06/21 20210510 NES 210510 The authors would like to draw attention to an error in Figure 2 A of this Research Article. In contrast, LDH loses 86.2 % activity in the second cycle and displays >99 % inactivation at the B fourth b cycle." Ultrafiltration membrane was used to separate SnSe nanosheets and LDH at each cycle of LA dehydrogenation reaction by LDH assay kit containing 20 mm LA and 50 mg mL-1 NAD+. [Extracted from the article]