FeOOH/Ni heterojunction nanoarrays on carbon cloth as a robust catalyst for efficient oxygen evolution reaction

Developing catalysts based on transition metal-based materials for oxygen evolution reaction (OER), which are cheap and efficient, is one of the keys to increase the rate of electrolysis of water to produce hydrogen. Herein, we successfully synthesize iron hydr(oxy)oxide nano-arrays on carbon cloth (FeOOH@CC), and then metallic nickel is electrodeposited on its surface to fabricate FeOOH/Ni heterojunction nanoarrays. Notably, the optimal FeOOH/Ni heterojunction nanoarrays catalyst shows high electrocatalytic performance toward OER with a small overpotential of 257.8 mV at 50 mA cm⁻², a Tafel slope of 30.8 mV dec⁻¹ and outstanding long-term stability in alkaline media. The superior OER performance could be ascribed to the introducing of metallic nickel. The nickel in-situ grows on the surface of FeOOH, which not only can improve the conductivity of FeOOH, but also cooperate with FeOOH to form the FeOOH/Ni heterogeneous interfaces for further enhancing OER electrocatalytic activities. This work provides a simple and efficient strategy of interface engineering to fabricate oxyhydroxide/metal heterojunction nanoarrays as high-efficiency OER catalysts.     

基于网络药理学和分子对接探究黄芪-女贞子治疗免疫缺陷病的作用机制

本文利用网络药理学和分子对接技术探索黄芪-女贞子治疗免疫缺陷病(IDD)的作用机制.综合利用TCMSP、Swiss Tagert Prediction和Genecards等在线数据库搜集黄芪-女贞子化学成分及治疗IDD靶点,构建黄芪-女贞子治疗IDD的"化合物-靶点-疾病"和蛋白互作网络;基于DAVID数据库及Clue...     

南美白对虾在酸性电解水减菌处理下鲜度品质及挥发性风味物质的变化

该研究就酸性电解水对南美白对虾减菌工艺条件进行了优化,在此基础上,采用GC-IMS技术分析美白对虾的挥发性风味物质,并结合感官评价、微生物指标(菌落总数和优势腐败菌)和理化指标(色度和TVB-N值)共同评价酸性电解水减菌处理对南美白对虾品质特性的影响.研究结果表明,酸性电解水对南美白对虾减菌的最佳处理方式为,电解水液温...     

Emitting area limitation via scattering control in phosphor film realizing high-luminance laser lighting

One major benefit of laser lighting is the possibility to achieve very high luminance. In phosphor-converted laser lighting systems, a blue (pump) laser can be focused into a very small spot. However, after excitation of the phosphor, the white-light-emitting area usually increases considerably, which reduces the luminance parameter substantially. Herein, we design and investigate a highly scattering YAG:Ce/glass composite film with a porous microstructure. Both the glass/phosphor interfaces and the introduced pores act as scattering centers, which can confine the emission area effectively. The relationship between the spot size and the microstructure (porosity, phosphor-particle size, thickness) is elucidated. Under excitation with blue laser, the composite film shows a uniform white-light emission with high luminous efficacy (230 lm/W) and high saturation threshold (> 40 W/mm²), thus achieving a high luminous exitance of ～1239 lm/mm². With above excellent properties, the designed composite films show great potential for use in high-luminance laser lighting.     

全基因组测序和real-time PCR法检测食源性沙门氏菌parC、gyrA基因突变特征

以45 株食源性沙门氏菌喹诺酮耐药株为对象,采取全基因组测序和实时聚合酶链式反应（real-time polymerase chain reaction,real-time PCR）法检测parC、gyrA基因突变位点,并对检测方法可靠性、耐药基因突变特征进行评估和分析。首先将4 株沙门氏菌进行二代全基因组测序,根据测序数据分析结果,建立了一种real-time PCR法检测gyrA Asp87Tyr、gyrA Asp87Asn、parC Thr57Ser和parC Ser80Ile这4 个突变位点。将沙门氏菌进行qnrS、qnrA、qnrB的real-time PCR检测,发现有31 株菌未检出qnr基因。以这31 株菌为对象,采取real-time PCR法筛查基因突变位点,结果发现parC Thr57Ser和gyrA Asp87Asn型突变最常见。将real-time PCR阳性的10 株菌扩增parC、gyrA基因全长并测序,real-time PCR检测和测序结果完全吻合,说明了real-time PCR检测的可靠性。全基因组测序和real-time PCR法相结合的方法用于耐药基因突变筛查,既可以发现新的基因突变,又可以快速筛查大样本的主要突变类型,可作为沙门氏菌耐药性研究的一种可靠手段。     

藤茶中二氢杨梅素对乳酸菌生长及活性的影响

该研究通过生长曲线和流式细胞术实验初步探索了藤茶中二氢杨梅素对嗜酸乳杆菌（Lactobacillus acidophilus）、德氏乳杆菌保加利亚亚种（Lactobacillus delbrueckii subsp. bulgaria）、嗜热链球菌（Streptococcus thermophilus）三种乳酸菌生长的影响。结果表明,二氢杨梅素添加量在100～1 000 μg/mL时,对三种乳酸菌均有显著促进其生长并提高其菌液活菌数量的作用（P＜0.05）;当二氢杨梅素添加量＞1 000 μg/mL时,对三种菌的生长和菌液中活菌的数量均表现出不同程度的抑制,其中德氏乳杆菌保加利亚亚种对二氢杨梅素最为敏感。在发酵后的菌液分析中,未明显观察到二氢杨梅素含量的降低,说明二氢杨梅素通过对生长环境进行调节影响乳酸菌生长。     

果胶酶产生菌的筛选鉴定和酶学性质研究

以果胶为唯一碳源,从海南采集的土样中筛选出一株能够利用果胶生长并产生果胶酶的菌株,采用3,5-二硝基水杨酸定糖法测定果胶酶酶活,通过生理、生化特性以及16S rRNA基因序列分析比对对菌株进行鉴定,并对其所产果胶酶的酶学性质进行研究。结果表明,分离筛选出一株果胶酶产生菌,编号为YY01,被鉴定为Bacillus niabensis。菌株YY01所产果胶酶的最适pH值为7.0,最适反应温度为45 ℃;在pH 10.0孵育12 h,仍有52.5%残余酶活力,50 ℃孵育6 h,仍有64%的残余酶活力。结果显示该酶有较好的耐碱性及较高的热稳定性,具有应用于果汁加工和胡椒脱皮的应用前景。     

Analysis of MicroRNA Expression Profiles in Weaned Pig Skeletal Muscle after Lipopolysaccharide Challenge

MicroRNAs (miRNAs) constitute a class of non-coding RNAs that play a crucial regulatory role in skeletal muscle development and disease. Several acute inflammation conditions including sepsis and cancer are characterized by a loss of skeletal muscle due primarily to excessive muscle catabolism. As a well-known inducer of acute inflammation, a lipopolysaccharide (LPS) challenge can cause serious skeletal muscle wasting. However, knowledge of the role of miRNAs in the course of inflammatory muscle catabolism is still very limited. In this study, RNA extracted from the skeletal muscle of pigs injected with LPS or saline was subjected to small RNA deep sequencing. We identified 304 conserved and 114 novel candidate miRNAs in the pig. Of these, four were significantly increased in the LPS-challenged samples and five were decreased. The expression of five miRNAs (ssc-miR-146a-5p, ssc-miR-221-5p, ssc-miR-148b-3p, ssc-miR-215 and ssc-miR-192) were selected for validation by quantitative polymerase chain reaction (qPCR), which found that ssc-miR-146a-5p and ssc-miR-221-5p were significantly upregulated in LPS-challenged pig skeletal muscle. Moreover, we treated mouse C2C12 myotubes with 1000 ng/mL LPS as an acute inflammation cell model. Expression of TNF-α, IL-6, muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1) mRNA was strongly induced by LPS. Importantly, miR-146a-5p and miR-221-5p also showed markedly increased expression in LPS-treated C2C12 myotubes, suggesting the two miRNAs may be involved in muscle catabolism systems in response to acute inflammation caused by a LPS challenge. To our knowledge, this study is the first to examine miRNA expression profiles in weaned pig skeletal muscle challenged with LPS, and furthers our understanding of miRNA function in the regulation of inflammatory muscle catabolism.     

Evaluation and mechanism of antifungal effects of carbon nanomaterials in controlling plant fungal pathogen

The antifungal activity of six carbon nanomaterials (CNMs, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), reduced graphene oxide (rGO), fullerene (C₆₀) and activated carbon (AC)) against two important plant pathogenic fungi (Fusarium graminearum (F. graminearum) and Fusarium poae (F. poae)) was evaluated. SWCNTs were found to show the strongest antifungal activity, followed by MWCNTs, GO, and rGO, while C₆₀ and AC showed no significant antifungal activity. The antifungal mechanism of CNMs was deduced to target the spores in three steps: (i) depositing on the surface of the spores, (ii) inhibiting water uptake and (iii) inducing plasmolysis.