Suppressing Manganese Dissolution from Lithium Manganese Oxide Spinel Cathodes with Single‐Layer Graphene

Spinel‐structured LiMn₂O₄ (LMO) is a desirable cathode material for Li‐ion batteries due to its low cost, abundance, and high power capability. However, LMO suffers from limited cycle life that is triggered by manganese dissolution into the electrolyte during electrochemical cycling. Here, it is shown that single‐layer graphene coatings suppress manganese dissolution, thus enhancing the performance and lifetime of LMO cathodes. Relative to lithium cells with uncoated LMO cathodes, cells with graphene‐coated LMO cathodes provide improved capacity retention with enhanced cycling stability. X‐ray photoelectron spectroscopy reveals that graphene coatings inhibit manganese depletion from the LMO surface. Additionally, transmission electron microscopy demonstrates that a stable solid electrolyte interphase is formed on graphene, which screens the LMO from direct contact with the electrolyte. Density functional theory calculations provide two mechanisms for the role of graphene in the suppression of manganese dissolution. First, common defects in single‐layer graphene are found to allow the transport of lithium while concurrently acting as barriers for manganese diffusion. Second, graphene can chemically interact with Mn³⁺ at the LMO electrode surface, promoting an oxidation state change to Mn⁴⁺, which suppresses dissolution.     

3D Si/C Fiber Paper Electrodes Fabricated Using a Combined Electrospray/Electrospinning Technique for Li‐Ion Batteries

Although the theoretical capacity of silicon is ten times higher than that of graphite, the overall electrode capacity of Si anodes is still low due to the low Si loading and heavy metal current collector. Here, a novel flexible 3D Si/C fiber paper electrode synthesized by simultaneously electrospraying nano‐Si‐PAN (polyacrylonitrile) clusters and electrospinning PAN fibers followed by carbonization is reported. The combined technology allows uniform incorporation of Si nanoparticles into a carbon textile matrix to form a nano‐Si/carbon composite fiber paper. The flexible 3D Si/C fiber paper electrode demonstrate a very high overall capacity of ≈1600 mAh g^‐1 with capacity loss less than 0.079% per cycle for 600 cycles and excellent rate capability. The exceptional performance is attributed to the unique architecture of the flexible 3D Si/C fiber paper, i.e., the resilient and conductive carbon fiber network matrix, carbon‐coated Si nanoparticle clusters, strong adhesion between carbon fibers and Si nanoparticle clusters, and uniform distribution of Si/C clusters in the carbon fiber frame. The scalable and facile synthesis method, good mechanical properties, and excellent electrochemical performance at a high Si loading make the flexible 3D Si/C fiber paper batteries extremely attractive for plug‐in electric vehicles, flexible electronics, space exploration, and military applications.     

下丘脑腹内侧核损毁对大鼠nesfatin-1/NUCB2表达的影响

目的:观察下丘脑腹内侧核(VMH)损毁对大鼠脂肪组织nesfatin-1/NUCB2表达的影响及其机制。方法:电损毁VMH,观察大鼠体重和脂肪组织变化,采用Western blot检测脂肪组织中nesfatin-1/NUCB2表达改变。腹腔注射6-羟多巴胺(50 mg/kg)以阻断交感神经;持续外周注射卡巴胆碱(180μg/kg)用以模拟VMH损毁,观察其对大鼠皮下脂肪nesfatin-1/NUCB2表达的影响。结果:与对照组和假手术组比较,VMH损毁后大鼠体重明显增加(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)也显著增多;Western blot分析结果显示,nesfatin-1/NUCB2在胰腺和肝脏中表达较多,但皮下、肠系膜脂肪和肩胛间棕色脂肪组织(i BAT)中表达较少,骨骼肌(腓肠肌)中鲜有表达;与对照组和假手术组比较,VMH损毁组大鼠nesfatin-1/NUCB2在肝脏、胰腺、骨骼肌和i BAT中表达无显著差异(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)nesfatin-1/NUCB2表达显著增多与对照组相比,6-羟多巴胺组nesfatin-1/NUCB2表达显著升高(t=3.43,P0.05),而卡巴胆碱组nesfatin-1/NUCB2表达无显著差异(t=0.37,P=0.72)。结论:VMH损毁后大鼠脂肪组织nesfatin-1/NUCB2表达改变可能通过抑制交感神经活动介导。     

Paradoxical Effects of All-Trans-Retinoic Acid on Lupus-Like Disease in the MRL/lpr Mouse Model

Roles of all-trans-retinoic acid (tRA), a metabolite of vitamin A (VA), in both tolerogenic and immunogenic responses are documented. However, how tRA affects the development of systemic autoimmunity is poorly understood. Here we demonstrate that tRA have paradoxical effects on the development of autoimmune lupus in the MRL/lpr mouse model. We administered, orally, tRA or VA mixed with 10% of tRA (referred to as VARA) to female mice starting from 6 weeks of age. At this age, the mice do not exhibit overt clinical signs of lupus. However, the immunogenic environment preceding disease onset has been established as evidenced by an increase of total IgM/IgG in the plasma and expansion of lymphocytes and dendritic cells in secondary lymphoid organs. After 8 weeks of tRA, but not VARA treatment, significantly higher pathological scores in the skin, brain and lung were observed. These were accompanied by a marked increase in B-cell responses that included autoantibody production and enhanced expression of plasma cell-promoting cytokines. Paradoxically, the number of lymphocytes in the mesenteric lymph node decreased with tRA that led to significantly reduced lymphadenopathy. In addition, tRA differentially affected renal pathology, increasing leukocyte infiltration of renal tubulointerstitium while restoring the size of glomeruli in the kidney cortex. In contrast, minimal induction of inflammation with tRA in the absence of an immunogenic environment in the control mice was observed. Altogether, our results suggest that under a predisposed immunogenic environment in autoimmune lupus, tRA may decrease inflammation in some organs while generating more severe disease in others.     

High-Density Genetic Linkage Map Construction and QTL Mapping of Grain Shape and Size in the Wheat Population Yanda1817 × Beinong6

High-density genetic linkage maps are necessary for precisely mapping quantitative trait loci (QTLs) controlling grain shape and size in wheat. By applying the Infinium iSelect 9K SNP assay, we have constructed a high-density genetic linkage map with 269 F ₈ recombinant inbred lines (RILs) developed between a Chinese cornerstone wheat breeding parental line Yanda1817 and a high-yielding line Beinong6. The map contains 2431 SNPs and 128 SSR & EST-SSR markers in a total coverage of 3213.2 cM with an average interval of 1.26 cM per marker. Eighty-eight QTLs for thousand-grain weight (TGW), grain length (GL), grain width (GW) and grain thickness (GT) were detected in nine ecological environments (Beijing, Shijiazhuang and Kaifeng) during five years between 2010–2014 by inclusive composite interval mapping (ICIM) (LOD≥2.5). Among which, 17 QTLs for TGW were mapped on chromosomes 1A, 1B, 2A, 2B, 3A, 3B, 3D, 4A, 4D, 5A, 5B and 6B with phenotypic variations ranging from 2.62% to 12.08%. Four stable QTLs for TGW could be detected in five and seven environments, respectively. Thirty-two QTLs for GL were mapped on chromosomes 1B, 1D, 2A, 2B, 2D, 3B, 3D, 4A, 4B, 4D, 5A, 5B, 6B, 7A and 7B, with phenotypic variations ranging from 2.62% to 44.39%. QGl.cau-2A.2 can be detected in all the environments with the largest phenotypic variations, indicating that it is a major and stable QTL. For GW, 12 QTLs were identified with phenotypic variations range from 3.69% to 12.30%. We found 27 QTLs for GT with phenotypic variations ranged from 2.55% to 36.42%. In particular, QTL QGt.cau-5A.1 with phenotypic variations of 6.82–23.59% was detected in all the nine environments. Moreover, pleiotropic effects were detected for several QTL loci responsible for grain shape and size that could serve as target regions for fine mapping and marker assisted selection in wheat breeding programs.     

Region-Oriented and Staged Treatment Strategy in Reconstruction of Severe Cervical Contracture

Introduction

Severe cervical contracture after burns causes obvious impairment of neck movement and the aesthetic silhouette. Although various surgical techniques for treatment have been described, there is not a definitive strategy to guide treatment. Over the past 6 years, we have been utilizing a region-oriented and staged treatment strategy to guide reconstruction of severe cervical contracture. Satisfactory results have been achieved with this strategy.

Methods

The first stage of treatment focuses on the anterior cervical region and submental region. Procedures include cicatrix resection, contracture release, division and elevation of the platysma to form two platysma flaps, and skin grafting. Three to six months later, the second stage treatment is performed, which localize to the mental region. This includes scar resection, correction of the lower lip eversion, and reconstruction with free (para)scapular skin flap. Three subtypes of cervicomental angle that we proposed were measured as quantitative tool for evaluation of the reconstruction.

Results

24 patients who completed the treatment were reviewed. By the 3rd postoperative month, their CM angles changed significantly: the soft tissue CM angle was reduced from 135.0° ± 17.3° to 111.1° ± 11.3°, the osseous CM angle increased from 67.1° ± 9.0° to 90.5° ± 11.6° and the dynamic CM angle increased from 21.9° ± 8.7° to 67.4° ± 13.1°. 22 in 24 (91.7%) of these patients gained notable improvement of cervical motion and aesthetic contour.

Conclusions

Our results suggest that the region-oriented and staged treatment strategy can achieve satisfactory functional and aesthetic results, combining usage of both skin graft and skin flap while minimizing the donor site morbidity.     

NMDA Receptor Antagonist Attenuates Bleomycin-Induced Acute Lung Injury

Background

Glutamate is a major neurotransmitter in the central nervous system (CNS). Large amount of glutamate can overstimulate N-methyl-D-aspartate receptor (NMDAR), causing neuronal injury and death. Recently, NMDAR has been reported to be found in the lungs. The aim of this study is to examine the effects of memantine, a NMDAR channel blocker, on bleomycin-induced lung injury mice.

Methods

C57BL/6 mice were intratracheally injected with bleomycin (BLM) to induce lung injury. Mice were randomized to receive saline, memantine (Me), BLM, BLM plus Me. Lungs and BALF were harvested on day 3 or 7 for further evaluation.

Results

BLM caused leukocyte infiltration, pulmonary edema and increase in cytokines, and imposed significant oxidative stress (MDA as a marker) in lungs. Memantine significantly mitigated the oxidative stress, lung inflammatory response and acute lung injury caused by BLM. Moreover, activation of NMDAR enhances CD11b expression on neutrophils.

Conclusions

Memantine mitigates oxidative stress, lung inflammatory response and acute lung injury in BLM challenged mice.     

A New Approach to Segment Both Main and Peripheral Retinal Vessels Based on Gray-Voting and Gaussian Mixture Model

Vessel segmentation in retinal fundus images is a preliminary step to clinical diagnosis for some systemic diseases and some eye diseases. The performances of existing methods for segmenting small vessels which are usually of more importance than the main vessels in a clinical diagnosis are not satisfactory in clinical use. In this paper, we present a method for both main and peripheral vessel segmentation. A local gray-level change enhancement algorithm called gray-voting is used to enhance the small vessels, while a two-dimensional Gabor wavelet is used to extract the main vessels. We fuse the gray-voting results with the 2D-Gabor filter results as pre-processing outcome. A Gaussian mixture model is then used to extract vessel clusters from the pre-processing outcome, while small vessels fragments are obtained using another gray-voting process, which complements the vessel cluster extraction already performed. At the last step, we eliminate the fragments that do not belong to the vessels based on the shape of the fragments. We evaluated the approach with two publicly available DRIVE (Staal et al., 2004) and STARE (Hoover et at., 2000) datasets with manually segmented results. For the STARE dataset, when using the second manually segmented results which include much more small vessels than the first manually segmented results as the “gold standard,” this approach achieved an average sensitivity, accuracy and specificity of 65.0%, 92.1% and 97.0%, respectively. The sensitivities of this approach were much higher than those of the other existing methods, with comparable specificities; these results thus demonstrated that this approach was sensitive to detection of small vessels.     

Is Demography Destiny? Application of Machine Learning Techniques to Accurately Predict Population Health Outcomes from a Minimal Demographic Dataset

For years, we have relied on population surveys to keep track of regional public health statistics, including the prevalence of non-communicable diseases. Because of the cost and limitations of such surveys, we often do not have the up-to-date data on health outcomes of a region. In this paper, we examined the feasibility of inferring regional health outcomes from socio-demographic data that are widely available and timely updated through national censuses and community surveys. Using data for 50 American states (excluding Washington DC) from 2007 to 2012, we constructed a machine-learning model to predict the prevalence of six non-communicable disease (NCD) outcomes (four NCDs and two major clinical risk factors), based on population socio-demographic characteristics from the American Community Survey. We found that regional prevalence estimates for non-communicable diseases can be reasonably predicted. The predictions were highly correlated with the observed data, in both the states included in the derivation model (median correlation 0.88) and those excluded from the development for use as a completely separated validation sample (median correlation 0.85), demonstrating that the model had sufficient external validity to make good predictions, based on demographics alone, for areas not included in the model development. This highlights both the utility of this sophisticated approach to model development, and the vital importance of simple socio-demographic characteristics as both indicators and determinants of chronic disease.     

Effects of low dietary protein on the metabolites and microbial communities in the caecal digesta of piglets

Thirty-six healthy piglets (weighing 10 ± 1 kg; three animals per pen) were randomly allocated to two treatments: (i) a low protein diet (14% crude protein [CP]) supplemented with lysine, methionine, threonine and tryptophan (Group LP) and (ii) a normal protein diet (20% CP, Group NP), resulting in six replicate pens per treatment. One piglet from each pen was slaughtered at days 10, 25 and 45 of the experiment. For the whole experimental period of 45 d, Group LP had lower feed intake and daily gain and a higher feed-to-gain ratio compared with Group NP. At day 10, no effects on measured caecum metabolites were observed, but at days 25 and 45 in Group LP the concentration of ammonia-N, cadaverine, branched chain fatty acids and acetate were reduced. This was also true for the concentration of short chain fatty acids at day 45. The results of denaturing gradient gel electrophoresis showed that microbial diversity in Group LP was less abundant at day 25, but there was no difference at days 10 and 45. An unweighted pair group mean average analysis showed that the similarities were lower between Groups LP and NP at day 10 and higher at days 25 and 45. Quantitation results indicated that the numbers of Firmicutes and Clostridium cluster IV were lower in Group LP than in Group NP at day 25, but there were no differences at days 10 and 45. In conclusion, the low protein diet markedly reduced the metabolites of protein and carbohydrate fermentation and altered microbial communities in the caecal digesta of piglets.