Xanthan gum is a natural complex exopolysaccharide produced by the phytopathogen Xanthomonas campestris pv. campestris(Xcc). It is polymerized from a repeating unit, which consists of the D-glucosyl, D-mannosyl, and D-glucuronyl residues and variable proportions of O-acetyl and pyruvyl residues. Because of xanthan gum’s outstanding rheological properties, it is widely used as a stabilizer and thickener in many industries including food, pharmaceutical and cosmetic industries. This review summarizes its structural characteristics, rheological properties, applications and fermentation conditions, as well as its biosynthetic pathways and regulation networks, paving the way for its further study.

One of the bottlenecks for wheat improvement is the narrowing of wheat genetic basis. Ethyl methyl sulfonate (EMS) is an efficient and stable alkylation mutagens, which can induce a series of allele mutations with high density, and make breakthroughs in creating of new varieties, new germplasm, genetic materials and solving some special problems in breeding. Based on the principles and characteristics of EMS mutagenesis, this paper briefly describes the method of EMS induction and mutagenesis selection for wheat, and draws an alternative scheme of EMS mutagenesis research, which provides research ideas and reference for wheat researchers. At the same time, the research progress of EMS mutagenesis technology in disease resistance gene cloning, quality trait improvement, leaf greening mechanism research, agronomic trait analysis, and mutant library construction was reported. The problems and countermeasures of EMS mutagenesis in wheat research were analyzed. The development prospect of EMS mutagenesis technology in wheat was prospected. This is of great significance for enriching wheat genetic resources, accelerating breeding processes and studying gene function.

Light-emitting diode (LED)is a semiconductor material that converts electrical energy into light energy. With the constant upgrading of LED technology, its application range is also extended from the traditional lighting field. In recent years, LED has received more and more attention in clinical application and experimental study, especially in the areas of skin diseases, arthritis, osteoporosis, wound healing and repair, anti-infection and immune regulation. This paper mainly reviews the study and application of LED red light in different clinical diseases.

Hepatitis C is caused by hepatitis C virus (HCV)infection, and is the leading cause of liver cirrhosis and liver cancer. HCV has become a serious threat to human health and become public health problems. HCV non-structure protein 5A is a target and hotspot of HCV inhibitor research in recent years. And we reviewed three domains of NS5A and the biological functions of each domain in hepatitis C virus replication, virus particle assembly and release. It provides a broad idea for the study of the mechanism of action of NS5A inhibitors, and is beneficial to the development of NS5A inhibitors.

As an internationally recognized standard method for carbon flux determination, the eddy covariance method has a broad space in the field of agro-ecosystem carbon flux studies. To provide references for eddy covariance method and carbon flux research in agro-ecosystem, the study aims to summarize the latest research results of agro-ecosystem carbon flux based on eddy covariance method. This paper reviews the research status of carbon flux over agro-ecosystem based on the eddy covariance method at home and abroad, and also put emphasis on the latest research results on the temporal variation characteristics, driving factors, productivity models and data processing. Through literature research, it is found that the eddy covariance method has many researches on the temporal variation characteristics of carbon flux in agro-ecosystems, and many research results show that the daily and seasonal changes of farmland carbon flux show a single-peak “U” trend in single planting mode, while in the multi-crop planting mode, the seasonal change is “W” type. But the carbon flux research on planting mode lacks regional representation. At the same time, the driving factor research focuses on the influence of environmental factors such as temperature, light and moisture on farmland carbon flux. Less research on the relationship between environmental factors and agronomic measures was done. And there is a lack of uniform standards for the processing of flux night data and elimination or interpolation of the invalidation and missing data. Therefore, this paper points out that the long-term continuous monitoring at the typical planting mode, multi-factor collaborative analysis, data quality control should be the important research directions.

Here, we report a novel metal-organic framework ZIF-8-based nanocomposite with encapsulated molybdenum disulfide(MoS2)nanosheets and doxorubicin(DOX)for pH- and NIR-triggered synergistic chemo/photothermal treatment of cancer cells. First, MoS2 nanosheets, which have uniform size of ~100 nm and topological height of 0.3~1.4 nm, are synthesized by hydrothermal reaction and ultrasonic treatment. Subsequently,an acid-degradable metal-organic framework ZIF-8 is employed to synchronously encapsulate MoS2 nanosheets and anti-cancer drug DOX to obtain DOX loaded ZIF-8 coated MoS2 (DOX/MoS2@ZIF-8)nanocomposites by one-step method. The nanocomposites are used for chemo/photothermal synergistic treatment of cancer cells: under acid conditions (e.g. pH 5.0 in a lysosome)and NIR laser irradiation (780 nm, 2.1 W/cm2), the ZIF-8 of the DOX/MoS2@ZIF-8 nanocomposites can be degraded, resulting in the release of encapsulated DOX, the cytosolic DOX can enter the nucleus to induce apoptosis. Meanwhile, the MoS2 nanosheets can effectively convert NIR laser light energy into heat energy, the photoinduced hyperthermia can also induce apoptosis. Thus, chemo/photothermal synergistic cancer therapy is realized. Cell viability assays show that this DOX/MoS2@ZIF-8 nanocomposites have an excellent chemo/photothermal synergistic treatment effect on SMMC-7721 cells, which can kill the tumor cells efficiently.

The seed oil of flax (Linum usitatissimum L.)is notable for its high level of polyunsaturated fatty acids including linolenic acid,which could be oxidized by lipoxygenase,which result in oxidative acidity of oils.Therefore, stability and off-flavors are vital characteristics that determine the quality of flax oil. Lipoxygenases (LOXs)are a class of non-heme iron containing dioxygenases which catalyze the hydroperoxidation of polyunsaturated fatty acids such as linoleic and linolenic acids. Experiments were conducted in order to elucidate the role of LOXs during seed development and in relation to seed oil quality. The full length cDNA of LuLOX1 was cloned based on flax whole genome DNA sequence database.The expression of LuLOX1 was determined by RT-PCR and the catalytic activity of LuLOX1 was determined by spectrophotometer. Results have shown that the CDNA of LuLOX1gene was 2 607 bp, encoding a protein of 868 amino acids. The molecular weight and isoelectric point of LuLOX1 were 97.87 kD and 6.36, respectively.RT-PCR carried out with RNAs extracted from seeds at different development stages showed that LOX is mainly expressed at early developmental stages.The results were consistent with those of LOX activity assays. The patterns of LuLOX1 expression were consistent with LuLOX1 activities.This indicated that LuLOX1 might be involved in regulation of fatty acid oxidation during seed development. These results laid the foundation for further study on the function of LuLOX1that may play an important role in enhancement of the quality of flaxseed oil through lipoxygenase.

To study the expression and spatial localization of Cx43 protein in different differentiated esophageal cancer cells and its effect on the biological behavior of esophageal cancer cells. The expression and distribution of Cx43 protein fluorophores in esophageal cancer cells were detected by image analysis of single particle tracking (SPT)with appropriate fluorescent probe and laser scanning confocal microscope. The distribution of Cx43 in EC9706 cells of highly differentiated esophageal squamous cell carcinoma was similar to that in esophageal carcinoma EC109 cells, especially the cell membrane showed obvious fluorophores. The content of Cx43 protein in the near-cell membrane was higher than that in the cytoplasm, which had the structural basis for building cell-cell communication of the cytomembrane and indicated the trend of benign development of the cell. The fluorescences of Cx43 protein in KY150 cells of poorly differentiated esophageal squamous cell carcinoma and SHEEC cells of esophageal carcinoma were mainly distributed in the cytoplasm near the nuclear membrane, but less distributed near the cell membrane. The content of Cx43 protein in the near-nuclear membrane was higher than that in the near-nuclear membrane, indicating the retention of Cx43 protein in the cytoplasm. Studies have suggested that SPT images can visually trace the distribution of fluorophore of Cx43 protein in esophageal cancer cells, so as to determine the trace of expression and localization of Cx43 protein in different differentiated esophageal cancer cells.

To investigate the regulatory effect of emodin on lipid profile in diet-induced hyperlipidemic rats and elucidate the molecular mechanisms involved, male SD rats were randomly divided into 4 groups (8 rats for each group) including control group, hyperlipidemia group, simvastatin group and emodin group.The control group was given normal diet, and others were given diet rich in cholesterol. In the meantime, the simvastatin group and emodin group was orally administrated with simvastatin(10 mg/kg) and emodin (10 mg/kg), respectively. After continous gavage for 38 days, the lipid profile was investigated by the content of serum total cholesterol(TC), triglyceride(TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C).The atherogenic index (AI) of each group was calculated and compared. Pathological features of liver histology were observed. Thoracic aortas were isolated and divided into two sections, one for in vitro incubation and detection of total nitric oxide (NO) content in supernatant, the other for measuring the mRNA expression level of endothelial nitric oxide synthase(eNOS) by realtime fluorescence quantification PCR and the protein expression level by western blotting. The results showed that emodin markedly attenuated the increased serum TC, TG and LDL-C induced by hypercholesterolemic diet. Compared with the hyperlipidemia group, emodin significantly reduced AI value. Liver histopathology examination showed that emodin observably reduced the degree of steatosis in hepatocytes of hyperlipidemic rats. Emodin significantly increased the secretion of NO in vitro, and also upregulated both the mRNA and protein expression levels of eNOS in thoracic aortas. The results of the present experiment indicate that emodin can lower serum TC,TG,LDL-C and reduce the atherogenic properties of dietary choleaterol in rats. Its antihyperlipidemic function may be due to upregulating the level of eNOS/NO system and protecting the blood vessel endothelium.

In this study,the effects of cell viscoelasticity under continuous and individual stress from different As(V)concentrations for the rice suspension cells was monitored in real-time by QCM and it was estimated on a overall level of cells. The results shows that: 1)In the range of 2~10 mmol/L,the effects of cell viscoelasticity under continuous and individual stress from As(V)increased with increasing concentrations of As(V); 2)Under continuous and individual stress,the viscoelasticity and hardness of rice suspension cells declined with the increasing concentrations of As(V); 3)The viscoelasticity index of rice cells declined under the stress of continuous gradient concentrations of As(V); 4)The sensitivity of rice suspension cells declined with the increasing concentrations of As(V).In the goal of establishing a new method to evaluate the effects of stresses of HMs on plants.

The TGF-β signaling plays multiple developmental and physiological functions in life. It is important to study the expression pattern of this signal family in vivo. gbb is a homolog gene of bmp7 in Drosophila. In order to study the effect of TGF-β signaling on embryonic development, a polyclonal antibody against Drosophila GBB was prepared. The cDNA sequence of the gbb was cloned (from the library) by cDNA library of Drosophila, and the eukaryotic expression plasmid pCAGGS-P7/gbb was constructed. The BALB/c mice were immunized with DNA immunoassay, and the polyclonal antibody against GBB was prepared by taking serum. The antibody was found to be effective by WB. Through immunofluorescence of Drosophila embryos, it was shown that GBB has no obvious expression at 0~9 h, however, highly expressed signal may be seen after 9 h.

The optical absorption of exogenous contrast agents in conventional photoacoustic imaging is mainly concentrated in the visible region and the traditional near infrared region (NIR, 750~900 nm). The development of near-infrared-II (NIR-II, 1 000~1 700 nm) nanoprobes with higher optical tissue penetration depth is of great significance for photoacoustic imaging of deep tissue in vivo. In this paper, semiconductor single-walled carbon nanotubes with optical absorption peaks of about 1 000 nm were selected as the exogenous contrast agent for near-infrared-Ⅱphotoacoustic imaging. The strong photoacoustic effect was tested under near-infrared-Ⅱlaser excitation. Furthermore, the deep photoacoustic imaging of the phantom tissue was obtained by embedding the nanomaterial in different depths of the tissue-mimic phantom. The imaging depth can reach 1.5 cm. Experimental results show that semiconductor single-walled carbon nanotubes (SWCNTs) with near-infrared-Ⅱ optical absorption have great potential in photoacoustic imaging of deep tissues in vivo.

In order to investigate the effects of LaCl3 on the growth and physiological characteristics of rice seedlings under drought stress, 15% PEG6000 was used to simulate drought stress. The effects of different concentrations of LaCl3 on the biomass, seedling index, root morphology, antioxidant system and malondialdehyde content of rice seedlings under drought stress were studied. The results showed that after spraying exogenous LaCl3, the indexes of rice seedlings under drought stress showed a concentration effect of low promoting and high suppression. 1 μmol/L LaCl3 can significantly promote the fresh weight of plants and the dry weight of aerial parts. 100 μmol/L LaCl3 can significantly increase the underground dry weight and seedling index, SOD activity of leaves and roots, CAT activity of leaves, and decrease of MDA content in roots. This study laid the foundation for the study of LaCl3 regulation of drought tolerance in rice seedlings.

With the rapid development of industrialization and urbanization, more and more materials including nanomaterials, heavy metals and biomass materials have been exposed in our life. In order to study the influencing mechanism of these materials in biological tissue, we investigated the biosafety of quantum dots materials. The aims were to assess physiological behavior and some gene expressions of Caenorhabditis elegans with quantum dots CdS/ZnS expoure. The results showed that the quantum dots inhited the biological behavior of Caenorhabditis elegans, and up-regulated the expression of some genes including the cytotoxic gene, stress-related gene and development related gene.The body length, head-swimming rate and body bending of C.elegans was down to (0.48±0.099) mm, (15.83±6.76) times/min and (7.72±1.12) times/20 s, from the control of (0.64±0.072) mm,(55.94±7.17) times/min and (9.95±2.42) times/20 s respectviely. And, the gene transcript of GST-1, daf-21, HSP-16.4 was up-regulation to 15.33, 19.51 and 35.01 folds respectviely with 3.33 nmol/L CdS/ZnS quantum dots exposure. This work highlights the utility of the Caenorhabditis elegans model as a multiflexible platform to allow noninvasively imaging and monitoring in vivo consequences of engineered nanomaterials.