混凝剂预处理非工艺低放废水研究

我国后处理工业示范厂和后处理大厂产生的非工艺低放废水具有年产生量大、成分复杂、污染核素种类多等特点。针对后处理非工艺低放废水的特点,初步探究了使用混凝剂处理非工艺低放废水的可行性。研究用非离子型聚丙烯酰胺(NPAM)为助凝剂,比较了聚合氯化铝(PAC)、聚合硫酸铁(PFS)、阴离子型聚丙烯酰胺(PAM)3种混凝剂对模拟非工艺低放废水中总有机碳(TOC)的去除效果。通过正交实验探讨了混凝效果的影响因素。结果表明:聚合氯化铝对模拟非工艺低放废水的混凝效果最佳,混凝剂的投加量是影响混凝效果的主要因素。当混凝剂和助凝剂的加入量分别为348 mg/L和24μg/L、混凝时间为30 min、pH=5时,得到去除模拟非工艺低放废水中TOC的最优方案,TOC去除率达到24%。     

A roadmap for interlayer excitons

Interlayer excitons in van der Waals heterostructures have tunable electron–hole separation in both real space and momentum space, enabling unprecedented contro...     

溶剂法合成2-羟基-1-萘甲酸的工艺研究

以β-萘酚和氢氧化钠为原料,正辛烷为溶剂,合成了2-羟基-1-萘甲酸,纯度达98%以上。通过正交实验研究了反应压力、反应温度和反应时间对收率的影响,确定了优化的工艺条件:反应压力0.8 MPa,反应温度90℃,反应时间8 h,该条件下收率达82.83%。     

黑莓果汁饮料生产流程中关键点的控制

为了保证黑莓果汁饮料成品的品质,对黑莓花色苷的稳定性及黑莓果汁饮料生产中三个关键控制点的工艺参数进行研究。采用感官品评、正交实验、方差分析及成品于38℃保温实验7d等方法,结果显示:随着加热温度的升高和时间的延长,黑莓汁花色苷含量下降速率增大;pH为2~3时黑莓花色苷较稳定;柠檬酸对实验结果的影响最大;最优的调配方案为柠檬酸0.15%,果葡糖浆5%,白砂糖4%,果胶0.05%;采用118℃/10s UHT、灌装温度大于85℃的生产工艺能很好的保存黑莓果汁饮料的色、香、味。为黑莓果汁饮料的生产提供了一套可行的工艺参数。      

介孔SiO2负载1,8-萘二酸酐结构表征及其荧光性能

分别利用单孔道MCM-41和双模型介孔分子筛(BMMs)作为载体通过氨丙基改性和负载荧光分子1, 8-萘二酸酐制备有机-无机杂化发光材料, 并采用XRD、TEM、SEM、BET、FT-IR、PL等手段对样品进行了结构表征.结果表明:具有双模型介孔结构的BMMs所制备的有机-无机杂化材料, 其发射峰位置(444 nm)较负载到单孔道的MCM-41中所制备的杂化材料的发射峰位置(450 nm)蓝移更明显, 主要原因是由于BMMs和MCM-41的颗粒形貌和大小不同所致.BMMs为球形颗粒(50 nm), 而MCM-41则为不规则颗粒且大小分布不均(1~3μm).     

Genome-Wide Identification and Expression Analysis of Fatty Acid Desaturase (FAD) Genes in Camelina sativa (L.) Crantz

Camelina sativa (L.) Crantz is an indispensable oilseed crop, and its seeds contain many unsaturated fatty acids. FAD (fatty acid desaturase) regulates the synthesis of unsaturated fatty acids. In this research, we performed CsFAD gene family analysis and identified 24 CsFAD genes in Camelina, which were unevenly distributed on 14 of the 19 total chromosomes. Phylogenetic analysis showed that CsFAD includes four subfamilies, supported by the conserved structures and motifs of CsFAD genes. In addition, we investigated the expression patterns of the FAD family in the different tissues of Camelina. We found that CsFAD family genes were all expressed in the stem, and CsFAD2-2 was highly expressed in the early stage of seed development. Moreover, during low temperature (4 °C) stress, we identified that the expression level of CsFAD2-2 significantly changed. By observing the transient expression of CsFAD2-2 in Arabidopsis protoplasts, we found that CsFAD2-2 was located on the nucleus. Through the detection and analysis of fatty acids, we prove that CsFAD2-2 is involved in the synthesis of linolenic acid (C18:3). In conclusion, we identified CsFAD2-2 through the phylogenetic analysis of the CsFAD gene family and further determined the fatty acid content to find that CsFAD2-2 is involved in fatty acid synthesis in Camelina.     

Circ_0011129 Encapsulated by the Small Extracellular Vesicles Derived from Human Stem Cells Ameliorate Skin Photoaging

Photoaging is not only the main cause of skin aging caused by exogenous factors, it is also related to a variety of skin diseases and even malignant tumors. Excessive and repeated exposure to ultraviolet radiation, especially UVA induces oxidative stress, DNA damage, inflammation, and collagen and elastin degeneration, ultimately leads to skin photoaging, manifested by skin redness, coarse wrinkles, and pigmentation even skin cancer. There has been a large demand of effective prevention and medications but approaches in the current management of photoaging are very limited. In the previous study, we found that a non-coding circular RNA circ_0011129 acts as a miR-6732-5p adsorption sponge to inhibit the reduction of type I collagen and the denaturation and accumulation of elastin in UVA-induced HDF cells photoaging model. However, in vivo instability and efficient delivery to the target cell of circRNA is a major challenge for its clinical application. Therefore, improving its stability and delivery efficiency are desired. In this study, we proposed a strategy of delivering circ_0011129 with small extracellular vesicles (sEVs) from human adipose-derived stem cells (hADSCs) to intervene in the photoaging process. The results showed that sEVs from hADSCs in 3D bioreactor culture (3D-sEVs) can prevent photoaging. Consequently, by overexpressing circ_0011129 in hADSCs, we successfully loaded it into 3D-sEVs (3D-circ-sEVs) and its protective effect was better. Our studies provide a novel approach to preventing skin photoaging, which has important clinical significance and application value for the development of non-coding RNA drugs to treat skin photoaging. We first screened out hADSCs-derived sEVs with excellent anti-oxidant effects. We then compared the sEVs collected from traditional 2D culture with 3D bioreactor culture. By miRNA-seq and GEO data analysis, we found that miRNAs in 3D-sEVs were enriched in cell activities related to apoptosis, cellular senescence, and inflammation. Subsequently, we prepared circ_0011129-loaded 3D-sEVs (3D-circ-sEVs) by overexpressing it in hADSCs for the treatment of photoaging in vitro. We proved that 3D-circ-sEVs can interfere with the process of cell photoaging and protect cells from UVA radiation damage, as well as in a H2O2-induced oxidative stress model.     

Lactoferrin Ameliorates Ovalbumin-Induced Asthma in Mice through Reducing Dendritic-Cell-Derived Th2 Cell Responses

Asthma is a chronic respiratory disease with symptoms such as expiratory airflow narrowing and airway hyperresponsiveness (AHR). Millions of people suffer from asthma and are at risk of life-threatening conditions. Lactoferrin (LF) is a glycoprotein with multiple physiological functions, including antioxidant, anti-inflammatory, antimicrobial, and antitumoral activities. LF has been shown to function in immunoregulatory activities in ovalbumin (OVA)-induced delayed type hypersensitivity (DTH) in mice. Hence, the purpose of this study was to investigate the roles of LF in AHR and the functions of dendritic cells (DCs) and Th2-related responses in asthma. Twenty 8-week-old male BALB/c mice were divided into normal control (NC), ovalbumin (OVA)-sensitized, and OVA-sensitized with low dose of LF (100 mg/kg) or high dose of LF (300 mg/kg) treatment groups. The mice were challenged by intranasal instillation with 5% OVA on the 21st to 27th day after the start of the sensitization period. The AHR, cytokines in bronchoalveolar lavage fluid, and pulmonary histology of each mouse were measured. Serum OVA-specific IgE and IgG1 and OVA-specific splenocyte responses were further detected. The results showed that LF exhibited protective effects in ameliorating AHR, as well as lung inflammation and damage, in reducing the expression of Th2 cytokines and the secretion of allergen-specific antibodies, in influencing the functions of DCs, and in decreasing the level of Th2 immune responses in a BALB/c mouse model of OVA-induced allergic asthma. Importantly, we demonstrated that LF has practical application in reducing DC-induced Th2 cell responses in asthma. In conclusion, LF exhibits anti-inflammation and immunoregulation activities in OVA-induced allergic asthma. These results suggest that LF may act as a supplement to prevent asthma-induced lung injury and provide an additional agent for reducing asthma severity.     

Regulation of Epstein-Barr Virus Minor Capsid Protein BORF1 by TRIM5α

TRIM5α is a host anti-retroviral restriction factor that destroys human immunodeficiency virus (HIV) virions and triggers innate immune signaling. TRIM5α also mediates the autophagic degradation of target proteins via TRIMosome formation. We previously showed that TRIM5α promotes Epstein-Barr virus (EBV) Rta ubiquitination and attenuates EBV lytic progression. In this study, we sought to elucidate whether TRIM5α can interact with and induce the degradation of EBV capsid proteins. Glutathione S-transferase (GST) pulldown and immunoprecipitation assays were conducted to identify interacting proteins, and mutants were generated to investigate key binding domains and ubiquitination sites. Results showed that TRIM5α binds directly with BORF1, an EBV capsid protein with a nuclear localization signal (NLS) that enables the transport of EBV capsid proteins into the host nucleus to facilitate capsid assembly. TRIM5α promotes BORF1 ubiquitination, which requires the surface patch region in the TRIM5α PRY/SPRY domain. TRIM5α expression also decreases the stability of BORF1(6KR), a mutant with all lysine residues mutated to arginine. However, chloroquine treatment restores the stability of BORF1(6KR), suggesting that TRIM5α destabilizes BORF1 via direct recognition of its substrate for autophagic degradation. These results reveal novel insights into the antiviral impact of TRIM5α beyond retroviruses.     

Studies of Mercaptosuccinic Acid-Crosslinked Chitosan Hydrogel with Grafted Cinnamaldehyde and Silver Nanoparticles for Antibacterial Biomedical Application

For the effective clinical antibacterial application of biomaterials, such as for wound management and tissue repair, the biomaterials need to show proper antibacterial capability as well as non-cytotoxicity. Furthermore, the material needs to have suitable mechanical characteristics for further medical use. Chitosan hydrogel is a potential candidate for various antibacterial biomedical applications due to its amine functionalities that lead to antimicrobial characteristics. Nevertheless, its antimicrobial capability is dependent upon the degree of protonation of amine groups caused by the pH value. Moreover, its mechanical compressive strength may not be high enough for clinical use if not chemically or physically crosslinked. This study utilized a novel chemical crosslinker, mercaptosuccinic acid, to improve its mechanical characteristics. The natural antibacterial agent, cinnamaldehyde, was grafted onto the crosslinked chitosan to improve its antimicrobial capability. Meanwhile, to take advantage of the thiol functionality in the mercaptosuccinic acid, the bactericidal silver nanoparticles were incorporated through silver-thiol covalent bounding. NMR analyses indicated the chitosan was successfully mercaptosuccinic acid-crosslinked and grafted with cinnamaldehyde at different ratios. Combined the results from the mechanical assessment, swelling experiments, antimicrobial assessment, and cytotoxicity assay, the chitosan hydrogel with the highest crosslinked degree and grafted with cinnamaldehyde and silver nanoparticles is of great promise for further clinical uses.