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•Degree of fragmentation in Wuhan become increasingly serious.•Ecological source (tributaries of the Yangtze River) contains more land use types than others.•Number of ecological ...corridors is decreasing.
The construction of the urban ecological network has a comprehensive effect on urban aesthetics, society and economy, and provides the driving force for urban sustainable development. However, we found few studies on constructing and optimizing urban ecological networks in cities with the highest human density. In this paper, landscape pattern indexes were applied to analyze the landscape characteristics and morphological pattern analysis (MSPA) to identify the ecological source, the landscape connectivity and the region attributes revised the ecological resistance surface, and urban ecological network was constructed by MCR model. The results show that: (1) many ecological land types mainly distributed in the tributaries of the Yangtze River, while only forest land and water areas occupied in the northwest are. (2) Compared with 1995 and 2005, the number of ecological corridors in 2015 was decreasing. Although the ecological connectivity was improved, which of the Yangtze River was limited. (3) The coordinated development and the ecological protection ecological network optimization plan would promote the connectivity of the urban ecological functioning stability. This study provides recommendations for the optimization of the urban ecological network, which are of great significance for protecting biodiversity, improving ecosystem functions, and maintaining the regional ecological security pattern.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
SIRT1, an NAD‐dependent deacetylase, plays a role in regulation of autophagy. SIRT1 increases mitochondrial function and reduces oxidative stress, and has been linked to age‐related reactive oxygen ...species (ROS) generation, which is highly dependent on mitochondrial metabolism. H2O2 induces oxidative stress and autophagic cell death through interference with Beclin 1 and the mTOR signaling pathways. We evaluated connections between SIRT1 activity and induction of autophagy in murine (m) and human (h) embryonic stem cells (ESCs) upon ROS challenge. Exogenous H2O2 (1 mM) induced apoptosis and autophagy in wild‐type (WT) and Sirt1−/− mESCs. High concentrations of H2O2 (1 mM) induced more apoptosis in Sirt1−/−, than in WT mESCs. However, addition of 3‐methyladenine, a widely used autophagy inhibitor, in combination with H2O2 induced more cell death in WT than in Sirt1−/− mESCs. Decreased induction of autophagy in Sirt1−/− mESCs was demonstrated by decreased conversion of LC3‐I to LC3‐II, lowered expression of Beclin‐1, and decreased LC3 punctae and LysoTracker staining. H2O2 induced autophagy with loss of mitochondrial membrane potential and disruption of mitochondrial dynamics in Sirt1−/− mESCs. Increased phosphorylation of P70/85‐S6 kinase and ribosomal S6 was noted in Sirt1−/− mESCs, suggesting that SIRT1 regulates the mTOR pathway. Consistent with effects in mESCs, inhibition of SIRT1 using Lentivirus‐mediated SIRT1 shRNA in hESCs demonstrated that knockdown of SIRT1 decreased H2O2‐induced autophagy. This suggests a role for SIRT1 in regulating autophagy and mitochondria function in ESCs upon oxidative stress, effects mediated at least in part by the class III PI3K/Beclin 1 and mTOR pathways. Stem Cells 2014;32:1183–1194
Efficient hematopoietic stem cell (HSC) homing is important for hematopoietic cell transplantation (HCT), especially when HSC numbers are limited, as in the use of cord blood (CB). In a screen of ...small-molecule compounds, we identified glucocorticoid (GC) hormone signaling as an activator of CXCR4 expression in human CB HSCs and hematopoietic progenitor cells (HPCs). Short-term GC pretreatment of human CB HSCs and HPCs promoted SDF-1-CXCR4-axis-mediated chemotaxis, homing, and long-term engraftment when these cells were transplanted into primary- and secondary-recipient NSG mice. Mechanistically, activated glucocorticoid receptor binds directly to a glucocorticoid response element in the CXCR4 promoter and recruits the SRC-1-p300 complex to promote H4K5 and H4K16 histone acetylation, facilitating transcription of CXCR4. These results suggest a new and readily available means to enhance the clinical efficacy of CB HCT.
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IJS, NUK, SBMB, UL, UM, UPUK
In recent years, marked progress has been made in wearable technology for human motion and posture recognition in the areas of assisted training, medical health, VR/AR, etc. This paper systematically ...reviews the status quo of wearable sensing systems for human motion capture and posture recognition from three aspects, which are monitoring indicators, sensors, and system design. In particular, it summarizes the monitoring indicators closely related to human posture changes, such as trunk, joints, and limbs, and analyzes in detail the types, numbers, locations, installation methods, and advantages and disadvantages of sensors in different monitoring systems. Finally, it is concluded that future research in this area will emphasize monitoring accuracy, data security, wearing comfort, and durability. This review provides a reference for the future development of wearable sensing systems for human motion capture.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The existing array antenna reliability evaluation method based on the n/k system is analyzed. As the failed T/R module's influence on the array antenna's performance is not considered, the ...reliability of the array antenna is overestimated. To improve the accuracy of the array antenna reliability evaluation, the performance changes caused by T/R failures in different locations are considered. The reliability evaluation method considering the performance changes is established. The performance and probability of the array antenna's state are calculated, and accurate reliability is obtained by calculating all the available state's probabilities. The complexity of the reliability evaluation method is analyzed, and the reliability evaluation method for large-scale array antennae is established. The large-scale array antenna is divided into several subarrays. The performance and reliability of each subarray are analyzed, and the array antenna's reliability is calculated through subarrays. The array antenna's performance changes are considered with the proposed method, the overestimation problem of the existing reliability evaluation method is solved, and the accuracy of the array antenna reliability evaluation is improved.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The global spread of SARS-CoV-2 is posing major public health challenges. One feature of SARS-CoV-2 spike protein is the insertion of multi-basic residues at the S1/S2 subunit cleavage site. Here, we ...find that the virus with intact spike (Sfull) preferentially enters cells via fusion at the plasma membrane, whereas a clone (Sdel) with deletion disrupting the multi-basic S1/S2 site utilizes an endosomal entry pathway. Using Sdel as model, we perform a genome-wide CRISPR screen and identify several endosomal entry-specific regulators. Experimental validation of hits from the CRISPR screen shows that host factors regulating the surface expression of angiotensin-converting enzyme 2 (ACE2) affect entry of Sfull virus. Animal-to-animal transmission with the Sdel virus is reduced compared to Sfull in the hamster model. These findings highlight the critical role of the S1/S2 boundary of SARS-CoV-2 spike protein in modulating virus entry and transmission and provide insights into entry of coronaviruses.
Enhancement of hematopoietic stem cell (HSC) homing and engraftment is clinically critical, especially for cord blood (CB) hematopoietic cell transplantation. Here we report that specific HDAC5 ...inhibition highly upregulates CXCR4 surface expression in human CB HSCs and progenitor cells (HPCs). This results in enhanced SDF-1/CXCR4-mediated chemotaxis and increased homing to the bone marrow environment, with elevated SCID-repopulating cell (SRC) frequency and enhanced long-term and secondary engraftment in NSG mice. HDAC5 inhibition increases acetylated p65 levels in the nucleus, which is important for CXCR4 transcription. Inhibition of nuclear factor-κB (NF-κB) signaling suppresses HDAC5-mediated CXCR4 upregulation, enhanced HSC homing, and engraftment. Furthermore, activation of the NF-κB signaling pathway via TNFα also results in significantly increased CXCR4 surface expression, enhanced HSC homing, and engraftment. These results demonstrate a previously unknown negative epigenetic regulation of HSC homing and engraftment by HDAC5, and allow for a new and simple translational strategy to enhance HSC transplantation.
•This study proposed a novel method based on the vulnerability definition of the IPCC framework and remote sensing.•The results indicated ecological vulnerability in NSFYM was at a moderate level and ...above.•Ecological vulnerability consists of ecological exposure degree, ecological sensitivity and ecological adaptive capacity.
Ecological vulnerability assessment is essential to environmental and resource management, especially given recent global warming concerns. However, evaluation of ecological vulnerability over large areas is difficult and complex because it is affected by many variables, including natural factors and human activities. Here, we propose a novel method to evaluate the vulnerability of an eco-environment with a typical ecologically fragile region, the northern and southern foothills of the Yinshan Mountains of Inner Mongolia, China (NSFYM), as a case study. The proposed method is based on the definition of the IPCC framework and remote sensing. The results showed that the ecological vulnerability in the NSFYM was moderate or high and had distinct regional variations in spatial distribution. Overall, 29% of the seriously and highly vulnerable areas appeared mainly in the highlands, where the natural conditions are poor and human activities have been developing rapidly. Additionally, 31% of the medium vulnerable levels occurred in the low lands, probably in response to agricultural practices. The areas that were found to have high ecological vulnerability exhibited high degrees of exposure and sensitivity and weak adaptive capacity and vice versa, consistent with the current understanding of the characteristics of ecological vulnerability. The integrated method proposed here will be useful for protection of eco-environments under climate change and proper planning for land use in the future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Recently, research on double-network (DN) hydrogels with good biocompatibility and mechanical properties has been flourishing. The main research directions have aimed to enhance the poor mechanical ...properties of conventional hydrogels and to broaden their potential applications in various fields. This paper reviews the recent research progress in the preparation of DN hydrogels, including fully chemically cross-linked DN hydrogels, hybrid physically/chemically cross-linked DN hydrogels, and fully physically cross-linked DN hydrogels. These DN hydrogels have significant advantages in mechanical properties, structure, biocompatibility and so on. Focus is placed on the enhancement mechanisms and preparation of different DN hydrogels. Besides, we also discussed the applications of DN hydrogels in drug and biomolecular carriers, flexible sensors and actuators, tissue engineering, medical dressings, ions/pollutant removal, and supercapacitors (SCs). These research advances are rapidly breaking away from the current limitations of DN hydrogels and providing new ideas for their future development.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
MXene as a kind of two-dimensional nanomaterial has aroused people’s strong research interest because of its excellent properties. In the present study, we introduced a new poly(vinyl ...alcohol)/poly(acrylic acid)/Fe3O4/MXene@Ag nanoparticle composite film fabricated by electrospinning and heat treatment as well as self-reduction reaction process. The obtained composite films showed high self-reduction ability because of the incorporation of MXene flakes. The intercalated MXene flakes in the composite nanofibers were evenly distributed, which not only solved the aggregation problem from MXene dispersion but also could self-reduce Ag nanoparticles in situ in composite materials. In addition, the composite nanofiber films exhibited good fiber structure, thermal stability, and magnetic properties. Moreover, the composite nanofiber films demonstrated excellent catalytic ability and cycle stability to 4-nitrophenol and 2-nitroaniline.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
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