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Chapter 1 presents the development of an efficient method for the expression and purification of aggregation-prone amyloid-β (Aβ) peptides, including Aβ(M1-42), 15N-labeled Aβ(M1-42), and Aβ(M1-42) familial mutants. Aβ peptides are central to the pathogenesis of Alzheimer’s disease. Aβ peptides are highly aggregation-prone, making them challenging to prepare and purify. Advances in amyloid research rely on improved access to Aβ peptides. Chemical synthesis of Aβ can lead to impurities, such as amino acid deletion products, that are difficult to eliminate during purification. Expression of Aβ(1-42) peptide requires the generation of fusion protein and cleavage by protease to remove the N-terminal methionine group that originates from the translational start codon, which can make the preparation of Aβ costly and time-intensive. In this chapter, I collaborated with fellow graduate student Stan Yoo to express Aβ(M1-42), a widely used form of Aβ with properties comparable to those of the native Aβ(1−42) peptide. Expression of Aβ(M1−42) is simple to execute and avoids the expensive and difficult enzymatic cleavage step associated with expression and isolation of Aβ(1−42). We then developed an efficient method to afford Aβ(M1-42) and 15N-labeled Aβ(M1-42) at around 19 mg per liter of bacterial culture with high purity using simple and inexpensive steps in three days. This method relies on the combination of protein biology tools such as bacterial expression and inclusion body solubilization, as well as peptide chemistry tools such as preparative HPLC purification of the solubilized inclusion bodies. This chapter also describes a simple method for the construction of recombinant plasmids and the preparation of Aβ peptides containing familial mutations. These methods may enable experiments that would otherwise be hindered by insufficient access to Aβ, such as NMR experiments with 15N-labeled Aβ. We anticipate that this method can be adjusted for the expression and purification of other amyloidogenic proteins.Chapter 2 presents the preparation of Aβ peptide with an N‑terminal cysteine [Aβ(C1–42)], the development of tailored chemical reaction conditions for the conjugation of aggregation-prone Aβ(C1–42) peptide with fluorophores or biotin, and the biophysical studies of labeled Aβ peptides.N-terminally functionalized Aβ peptides are important in amyloid and Alzheimer’s disease research. Site-specific labeling on the N-terminus of Aβ minimizes perturbation in the structure and function of the peptide, as the central and C-terminal regions of Aβ are more involved in fibril and oligomer formation. Although synthetic N-terminally functionalized Aβ peptides are commercially available, these peptides are expensive and limited to biotin and a few common fluorophores. Expressed Aβ peptides offer advantages over synthetic Aβ because they are free from amino acid deletions and epimeric contaminants, and they have been found to be more biological relevant because they aggregate more quickly and are more neurotoxic than synthetic Aβ. The method of preparing Aβ(C1–42) relies on the hitherto unrecognized observation that the expression of the Aβ(MC1-42) gene yields the Aβ(C1–42) peptide, because the N-terminal methionine is endogenously excised by E. coli. This observation is significant, because it allows the preparation of a useful Aβ(C1–42) peptide without the additional N-terminal methionine that originates from the translational start codon. The Aβ(C1–42) peptide represents a minimal modification of native Aβ(1–42), and the addition of a single cysteine residue at the N-terminus enables labeling of the expressed Aβ with complete site specificity using widely available maleimide-based reagents.The Aβ peptide is challenging to handle and label because of its strong propensity to aggregate. This chapter details the development of tailored chemical reaction conditions for handling and labeling of this aggregation-prone peptide. The labeling chemistry was optimized to be performed at pH 9 in HPLC fractions Aβ(C1–42), where Aβ remains mostly monomeric. Biophysical studies show that the labeled Aβ peptides behave like unlabeled Aβ and suggest that labeling of the N-terminus does not substantially alter the properties of the Aβ. This chapter also goes on to demonstrate the utility of the labeled Aβ peptides through fluorescence microscopy to visualize their interactions with mammalian cells and bacteria. Ready access to labeled Aβ bearing fluorophores will advance amyloid and Alzheimer’s disease research by enabling experiments for investigating the pathogenic mechanism, transport, and clearance of Aβ, as well as for screening anti-Aβ antibodies.Chapter 3 presents the introduction of intramolecular disulfide bonds to Aβ peptides that stabilizes Aβ into oligomeric state and the discovery of a disulfide-stapled peptide, AβC18C33, that forms homogeneous dimers and does not fibrilize. Aβ aggregates rapidly and exists as three different forms in equilibria: monomers, oligomers, and fibrils. Although Aβ fibrils are the most commonly found species in the brain tissue of patients with Alzheimer’s disease, soluble Aβ oligomers are the toxic contributors to neurodegeneration. Aβ oligomers are heterogenous and metastable: they can rapidly aggregate into more thermodynamically stable fibrils, which makes it challenging to isolate them and study their structures and biological properties. No high-resolution structures of Aβ oligomers have been reported thus far. Filling this gap is necessary for an enhanced understanding of the molecular basis of Alzheimer’s disease.In this chapter, we aimed to generate stable, non-covalent Aβ oligomers by introducing intramolecular disulfide linkages to Aβ. The intramolecular linkages were designed to enforce a β-hairpin conformation, the key conformation that favors Aβ oligomer formation and disfavors fibrilization. We have designed, prepared, and studied a variety of mutant Aβ peptides containing intramolecular linkages. Among these mutant peptides, we discovered AβC18C33, an Aβ peptide containing a disulfide bond between positions 18 and 33, that forms stable, homogeneous dimers and does not fibrilize, as evidenced by the results of a series of biophysical studies. The Aβ dimer has been proposed to be the basic building block of many larger Aβ oligomers and is thought to be one of the most neurotoxic and pathologically relevant species in Alzheimer’s disease. We thereby anticipate that the AβC18C33 peptide to serve as a stable, non-fibrilizing, and noncovalent Aβ dimer model for the exploration of the structure and pathogenesis of Aβ dimers, the generation of Aβ-specific antibodies, and the screening of Aβ-targeted drugs. Our laboratory is exploring ways to obtain high-resolution structures of this dimeric Aβ model peptide, using techniques including cryo-EM, NMR, and X-ray crystallography. Chapter 4 presents the structure-based design of a cyclic peptide inhibitor towards SARS-CoV-2 using free molecular modeling and docking software and publicly available X-ray crystallographic structures. When the COVID-19 pandemic forced the temporary closure of our laboratory in March 2020, we began working on the structure-based drug design of inhibitors against the SARS-CoV-2 virus main protease. These efforts resulted in the design of a cyclic peptide inhibitor, UCI-1. Working with other group members, I published a tutorial paper based to describe the structure-based drug design process and teach others how to do it using the publicly available software UCSF Chimera and AutoDock Vina.SARS-CoV-2 is a highly infectious virus that causes COVID-19, a serious respiratory infection that has caused over 178 million infections and over 3.8 million deaths worldwide as of June 2021. Main protease is a crucial enzyme that SARS-CoV-2 utilizes for site-specifically cleaving the polyprotein that is translated from viral mRNA and generating mature proteins that are necessary for replication and infection. The essential role of main protease, as well as the success of HIV protease inhibitors in the treatment of AIDS, make main protease an attractive therapeutic target in the treatment of COVID-19.This chapter begins with the analysis of the X-ray crystallographic structure of the main protease of the SARS coronavirus (SARS-CoV) bound to a peptide substrate. This chapter then describes the structural modification of the peptide substrate using the UCSF Chimera molecular modeling software to create a cyclic peptide inhibitor. Finally, this chapter presents the use of molecular docking software AutoDock Vina to show the interaction of the cyclic peptide inhibitor with both SARS-CoV main protease and the highly homologous SARS-CoV-2 main protease.The supporting information section of this chapter provides an illustrated step-by-step protocol showing the inhibitor design process. These and other molecular modeling studies helped our laboratory decide to pursue the synthesis of the cyclic peptide and experimentally evaluate its promise as an inhibitor of SARS-CoV-2 main protease. The molecular modeling studies presented in this chapter may help students and scientists design their own drug candidates for COVID-19 and the coronaviruses that may cause future pandemics.

Cinchona alkaloids are natural products extracted from cinchona plants, which contain quinine, quinidine, cinchonine, and cinchonidine. During the past 30 years, due to their attractive structural properties, these compounds have been used as chiral skeletons and organocatalysts in asymmetric organic synthesis. In this review, we summarize the applications of cinchona alkaloids derivatives in asymmetric catalysis recently developed by our group, including oxidation, reduction, and C-C bonds formation. These studies have solved some of the problems with the various asymmetric reactions discussed, while also enriching alkaloids chemistry, providing new ideas for the design and synthesis of chiral catalysts, and providing abundant experimental data for the chiral induction process.

The effects of heat treatment on the mechanical properties of plain-woven SiC/SiC composites at 927 °C and 1200 °C in argon were evaluated through tensile tests at room temperature and at elevated temperature on the as-received and heat-treated plain-woven SiC/SiC composites, respectively. Heat treatment can improve the mechanical properties of composites at room temperature due to the release of thermal residual stress. Although heat treatment can damage the fiber, the effect of this damage on the mechanical properties of composites is generally less than the effect of thermal residual stress. Heat treatment will graphitize the pyrolytic carbon interface and reduce its shear strength. Testing temperature will affect the expansion or contraction of the components in the composites, thereby changing the stress state of the components. This study can provide guidance for the optimization of processing of ceramic matrix composites and the structural design in high-temperature environments.

The sensitivity of strength via temperature for SiC/SiC composites and SiC fibers in an oxygen-free environment is studied through experimental investigation and theoretical analysis. Tensile tests are performed on SiC/SiC minicomposites at room temperature, 500 and 1000 ℃ in an oxygen-free environment. A high-efficiency method is proposed to obtain the high-temperature strength distribution of SiC fibers. The experimental results show that the sensitivity of strength via temperature is high for SiC fibers but low for SiC/SiC minicomposites. To explain this phenomenon, the strength model of minicomposites is developed. The theoretical analysis reveals that the low sensitivity of strength via temperature for minicomposites results from that the influences of the changes of the Weibull parameters m and σ0 at elevated temperatures are offset.

Newly structured pH-responsive smart surfactants (N+ -(n)-N, n=14, 16) from alkyl trimethylammonium bromides are reported. In neutral and alkaline media N+ -(n)-N behaves as a normal cationic surfactant and stabilizes conventional emulsions alone, as well as Pickering emulsions and oil-in-dispersion emulsions together with oppositely and similarly charged nanoparticles, respectively. In acidic media N+ -(n)-N becomes a hydrophilic Bola-type surfactant, N+ -(n)-NH+ , and is an inferior emulsifier either when used alone or together with charged nanoparticles, resulting in demulsification. N+ -(n)-NH+ returns to the aqueous phase alone or together with nanoparticles after demulsification without contaminating the oil phase, and the aqueous phase can be recycled when triggered by pH change. This protocol is a green process and leads to preparation of various temporarily stable emulsions which are often used in emulsion polymerization, heterogeneous catalysis, and oil transportation.

The purpose of the present study was to determine the effects of metformin on the inhibition of proliferation, apoptosis, invasion and migration of A172 human glioma cells in vitro and determine the underlying mechanism. The effects of metformin at different concentrations (0, 0.1, 1 and 10 mmol/l) on the inhibition of A172 cell proliferation were detected using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was detected by flow cytometry. Caspase-3 activity was analyzed by spectrophotometry. The invasion and migration of cells were detected by Transwell assays. The levels of Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), AMP-activated protein kinase (AMPK), phosphorylated-(p)AMPK and mechanistic target of rapamycin (mTOR) protein expression were detected by western blot analysis, and changes in the malondialdehyde (MDA) content and activity of superoxide dismutase (SOD) were determined. Compared with the control group, metformin significantly increased the inhibition of proliferation and apoptosis, and significantly reduced the invasion and migration of A172 cells in dose- and time-dependent manners (P

The titanium body porcelain was synthesised through sol–gel using borate–silicate system. The porcelain was characterised by X-ray diffraction (XRD), scanning electron microscope and three-point fl...

Plasma levels of PCSK9 are significantly higher in postmenopausal women. Pharmacologically increased estrogen levels have been shown to lower PCSK9 and LDL-C levels in animals and humans. The action of estrogen suggests that it has the ability to prevent PCSK9-mediated LDLR degradation in liver cells. However, little is known about how estrogen alters PCSK9-mediated LDLR degradation. Here, we report that 17β-estradiol (βE2) reduces PCSK9-mediated LDLR degradation by a mechanism that involves activation of the G protein-coupled estrogen receptor (GPER). In cultured HepG2 cells, βE2 prevented the internalization of PCSK9, which subsequently lead to PCSK9-mediated LDLR degradation. The altered LDLR levels also resulted in an increase in LDL uptake that was not observed in the absence of PCSK9. In addition, we showed that clathrin was rapidly increased in the presence of PCSK9, and this increase was blocked by βE2 incubation, suggesting rapid recruitment of clathrin in HepG2 cells. PLCγ activation and intracellular Ca2+ release were both increased due to the rapid effect of estrogen. By using a GPER antagonist G15, we demonstrated that the GPER mediates the action of estrogen. Together, the data from this in vitro study demonstrate that estrogen can regulate LDLR levels mainly through GPER activation, which prevents PCSK9-dependent LDLR degradation in HepG2 cells.

Star-like nano-ZrO2 has been synthesized using Zr(NO3)4·5H2O as zirconium source by a hydrothermal process without any template and surfactant. The structure of the as-prepared ZrO2 powder was investigated by multiple advanced analytical methods. The results showed that CH3COO− and NO3− had great effects on the formation of star-like ZrO2 nanostructures. The as-prepared ZrO2 had a superior catalytic activity, and the reason for it was analyzed by UV-Vis diffuse reflectance spectroscopy. The effect of raw material ratios on the photocatalytic property of ZrO2 was studied. The synthesized ZrO2 showed a narrow bandgap (3.50–3.85 eV) and an excellent photocatalytic activity, and the degradation of RhB was up to nearly 100% in 30 min with this photocatalyst.

Novel Bi2O4/BiOBr heterojunctions were fabricated via a chemical etching process. BiOBr nanosheets could be in-situ generated in Bi2O4 micro-rods, which greatly improved the interface quality. The photocatalytic performance of samples was evaluated by the degradation of rhodamine B(RhB) and methyl orange (MO) under visible light irradiation. The results showed that Bi2O4/BiOBr heterojunctions displayed higher photocatalytic activity than pure Bi2O4 and BiOBr, and 99.3% MO could be degraded in 60 min over 0.4BB (~ 33.3 mol% BiOBr) sample. The effective separation and transfer of the photogenerated electrons and holes were believed to be the main factor for the enhanced activity, and the holes (h+) and ·O2− radicals were confirmed to be the main active species. This work offers an effective route to the fabrication of Bi2O4/BiOBr heterojunctions with high interface quality for photocatalytic applications.

The study aims at deriving an equation for the temperature field of the specimen- vapour-gaseous envelope (VGE) – electrolyte three-phase system, followed by the calculation of the temperature distribution expression. The diffusion mechanism of carbon and nitrogen, in light of the theory of molecular diffusion, and the mechanism behind the plasma electrolytic saturation, is also discussed. In the PES process, the diffusion of carbon and nitrogen is affected by the strengthening voltage and processing time, which in turn affects the thickness and element distribution of the diffusion layer. Carbon, of which the diffusion depth ranges from 0.5 μm to 2.5 μm, is mainly distributed into the outermost layer. While the nitrogen is able to distribute throughout the diffusion layer as indicated by its several tens microns of diffusion depth. Further, the influence of process parameters on the diffusion of atoms during the strengthening process is verified experimentally.

By in-situ oxidative polymerization method, a novel flower-like polyaniline/graphitic carbon nitride (PANI/g-C3N4) nanocomposite was successfully synthesized. In comparison with single PANI, PANI/g-C3N4 displayed enhanced electrochemical performance which had a specific capacitance of 584.3 F g−1 and 81.91% of capacitance retention after 1000 cycles at 1 A g−1. This work demonstrated a simple strategy of improving the specific capacitance and cycling stability of polymer electrodes and may be extended to other similar systems.

Novel g-C3N4 decorated Bi2O4 heterojuction photocatalysts were prepared via a hydrothermal method. The obtained samples were characterized by using XRD, SEM, EDS mapping, FT-IR, XPS and DRS. After the introduction of g-C3N4, g-C3N4 nanostructure was evenly distributed on Bi2O4 nanorods, forming heterojunction composites with staggered band alignments. The photocatalytic performance was evaluated by the degradation of methyl orange under visible light irradiation. The g-C3N4/Bi2O4 composites exhibited significantly enhanced photocatalytic activity. Among them, 10CB sample displayed the highest degradation efficiency, whose apparent rate constant was 2.2 and 11.8 times higher than that of Bi2O4 and g-C3N4, respectively. Besides, by combining Bi2O4 with g-C3N4, the composites showed decent photochemical stability. It was assumed that the enhanced photocatalytic activity and photostability could be ascribed to the formation of heterojunction, which effectively promoted the separation and transfer of photogenerated charge carriers.

To investigate the mechanical properties of pressed and sintered PTFE/Al/Ni (polytetrafluoroethylene/aluminum/nickel) composite, uniaxial quasi-static and dynamic compression experiments were conducted at strain rates from 10−2 to 3 × 103/s. The prepared samples were tested by an electrohydraulic press with 300 kN loading capacity and a split Hopkinson pressure bar (SHPB) device at room temperature. Experimental results show that PTFE/Al/Ni composite exhibits evident strain hardening and strain rate hardening. Additionally, a bilinear relationship between stress and $${\text{log(}}\dot{\varepsilon } )$$ is observed. The experimental data were fit to Johnson-Cook constitutive model, and the results are in well agreement with measured data.

The extracellular region (EC) of the vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) contains seven immunoglobulin-like (Ig-like) domains that are required for specific ligand binding and receptor dimerization. Studies of domain 4–7 deletions and substitutions provided insights into the interaction between receptors in the absence of VEGF. In this study, we investigated the effect of domain 4 in ligand-independent VEGFR-2 dimerization and activation in human vascular endothelial cells and human breast cancer cells. To confirm the role of domain 4 in ligand-independent receptor dimerization and activation, two VEGFR-2 fragments with and without domain 4, KFP1 and KFP2, were generated by recombinant DNA technology. We measured the affinity of KFP1 and KFP2 with VEGFR-2, and the roles of KFP1 and FKP2 in dimerization and phosphorylation of VEGFR-2. We also evaluated the effect of KFP1 and FKP2 on cell proliferation and migration in HUVECs and in human breast cancer cells. We showed that KFP1 did not affect the interaction of VEGFR-2 and VEGF but bound VEGFR-2 in the absence of VEGF. Furthermore, cross-linking and cross-linking immunoblotting demonstrated that KFP1 could form a complex with VEGFR-2, which resulted in VEGFR-2 dimerization in the absence of VEGF. Importantly, we found that the KDR fragment with domain 4 induced phosphorylation of VEGFR-2, as well as phosphorylation of downstream receptor kinases in HUVECs and VEGFR-2-positive breast cancer cells. Consistent with these results, this ligand-independent activation of VEGFR-2 also promoted downstream signaling and cell proliferation and migration. The domain 4 of VEGFR-2 plays an important role in the interaction between VEGFR receptors in the absence of VEGF.

In this study, the complete mitochondrial genome of Pangasius sanitwongsei was firstly reported and analyzed. It had a double-stand DNA molecule with 16536 bp in length, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and one control region. The structural organization and gene order was similar to other bony fishes. The complete mitochondrial genome of P. sanitwongsei provided in this work would be helpful for further research on phylogenetics and conservation genetics of the Siluriformes and other orders.

A self-healing coating with UV-shielding property was prepared in this paper. The self-healing property was based on the inclusion between a host (&beta, CD-TiO2) and a guest HEMA-Ad). After inclusion of the host and guest, the host&ndash, guest complex (HEMA-Ad/&beta, CD-TiO2) was polymerized with other reactive monomers (HEMA and BA) to obtain the final coating. The coating had good hydrophobicity (water contact angle &gt, 90&deg, moisture absorption rate &lt, 2%) and excellent UV-shielding performance (ultra-violet protect factor &gt, 90%), and could be firmly bonded to a soft substrate. In addition, the coating had good self-healing property, which means that cracks in the material can recover many times after being damaged and that the UV-shielding ability can be fully restored with the self-healing process.

Background: To explore the triggering mechanism of interstitial lung disease (ILD) by establishing the effects of immunogenic and neurogenic calcitonin gene-related peptide (CGRP) imbalance on the regulation of AQP5 expression and the repair responses to promote alveolar epithelial cell (AEC) apoptosis in pulmonary fibrosis. Methods: Newly diagnosed ILD patients (n=60) were enrolled, whoseserological levels of β-CGRP, α-CGRP, AQP5, RAMP1, and RCP were detected by ELISA. Th1 and Th2 cytokines and CD4+ and CD8+ cells were measured by flow cytometry method (FCM). In vivo, bleomycin (BLM) was set for modeling pulmonary fibrosis. The CALCA-HET model was set as a chronic pulmonary fibrosis model. Hematoxylin-eosin (H&E), immunohistochemistry, Masson's trichrome staining, and TUNEL staining was performed to assess the role of apoptosis in the injured lung. The concentrations of cytokines were determined by cytokine antibody arrays. Results: Abnormal activation of serological CD4+T lymphocytes and predominant Th2 response was established in patients with ILD. Moreover, the ratio of β-CGRP/α-CGRP was positively correlated with the increased level of AQP5 in patients with ILD. In vivo, a significant increase of AQP5 and β-CGRP at the chronic stage of pulmonary fibrosis induced by bleomycin in mice model, whereas the expression of AQP5 protein was the generally decreased in the acute alveolitis phase. Moreover, the levels of AQP5 and α-CGRP in the CALCA-HET rats were elevated. The high ratio βCGRP/α-CGRP enhanced the expression of AQP5, inhibited TGFβ1/PSmad1/Smad4 pathway, and upregulated NRF2 signal, whereas the apoptosis of alveolar epithelial cells was significantly reduced in late-stage pulmonary fibrosis. Conclusions: The high ratio of β-CGRP/α-CGRP induced predominant Th2 response and promoted AEC apoptosis through inactivation of the TGFβ1/smad1 signaling pathway and upregulation of the Nrf2 signaling in the chronic stage of pulmonary fibrosis. Funding Statement: This work was financially supported by the National Natural Science Foundation of China (no.81800070 to Xiaoting Lv and no.81871293, no.81571613 to Qicai Liu), the Joint Fund for Program of Science innovation of Fujian Province (no.2016Y9011 to Feng Gao), the Sail Foundation of Fujian Medical University (no.2016QH063 to Xiaoting Lv). Declaration of Interests: The authors have no competing interests to declare. Ethics Approval Statement: This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Fujian Medical University (no. [2016]156). Consent for participation and publication the case reports was obtained. The animal experiment was approved by the Experimentation Ethics Committee on Animal Rights Protection of Fujian Medical University Animal Experiment Center (Fujian, China). During the experiments, the animals were treated in compliance with the “Guiding Opinions on the Ethical Treatments of Laboratory Animals” published by the Ministry of Science and Technology in 2006. All procedures strictly followed the National Institutes of Health guidelines for the care and use of laboratory animals.

To study the effect of the addition of potassium perchlorate (KClO4) on the performance of nano thermites, Al/Bi2O3 nano thermites with different mass fraction (wt%) of KClO4 was made by ultrasonic dispersion method. Then, all samples were tested by SEM, DSC and rapid excitation ignition. DSC results showed Al/Bi2O3/10 wt%KClO4 had the highest heat release. Compared with Al/Bi2O3, the heat release increased by 28.32%. The results of activation energy calculations showed Al/Bi2O3/30 wt%KClO4 had the lowest activation energy (Ea). Its activation energy was reduced by 30%, mere about 149.17 KJ mol−1. Finally, it can be seen from the combustion situation that the addition of KClO4 reduced the intensity of burning. This work found a way to increase the heat release or reduce the activation energy of nano thermites by controlling the amount of KClO4 added.

Erbium (Er) doped Bi24O31Br10 samples were successfully prepared by using a solvothermal method. The samples were characterized by XRD, XPS, SEM, TEM, BET, DRS, PL and EIS. The photocatalytic activity was evaluated by the degradation of rhodamine B (RhB) and methyl orange (MO) under visible light irradiation. The result shows that Er dopant induces a significant improvement in the photocatalytic activity. 1.0% Er–Bi24O31Br10 sample exhibits the best photocatalytic performance. The enhanced photocatalytic activity is attributed to the effective trapping of photogenerated electron by Er3+ ion and the up-conversion process resulting from Er dopant. In addition, it is found that holes and super-oxide radicals play main role in the photocatalytic degradation of RhB and MO.

Heat shock protein 70 (HSP70) is molecular chaperone that is important for reproductive biological processes. In this study, a full length HSP70 from the mudskipper (Boleophthalmus pectinirostris) was characterized. It was found to contain: a 108 bp 5'-untranslated region, a 208 bp 3'-untranslated region, and a 1953 bp open reading frame, which encodes a protein of 650 amino acids with a theoretical molecular weight of 71.1 kDa and an isoelectric point of 5.17. RT-PCR analysis revealed that HSP70 was ubiquitously expressed in all major tissues with differential expression levels. This suggests that HSP70 has vital and conserved biological functions. HSP70 was localized mainly in the cytoplasm of germinal cells, indicating an important role of this protein during spermatogenesis. In response to heat stress, the testes presented abnormal morphology in connective tissues, in which HSP70 immunoreactivity was not observed. HSP70 mRNA expression in the gill, liver, and testes was significantly increased, which suggests that HSP70 plays an important role in protection against heat stress.

The supercapacitors with conventional multilayer structure exhibit a large contact resistance and tend to delaminate because of the relative displacement under external force. Herein, the all-in-one flexible supercapacitors are fabricated by integrating chemically crosslinked hydrogel electrolytes with conducting copolymer electrodes. The hydrogel electrolyte is prepared by chemically crosslinking reaction of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) with glutaraldehyde (GA) where the hydroxyl groups (-OH) of PVA and PEG react with aldehyde groups (-CHO) of GA to form acetal or hemiacetal in sulphuric acid solution. The prepared hydrogel electrolyte exhibits better mechanical properties (tensile strength of 36 KPa under strain of 117%) and remarkable ionic conductivity (67.1 mS cm−1) than pure PVA hydrogel. Based on this gel electrolyte, a novel flexible supercapacitor with an all-in-one (electrode-electrolyte-electrode) configuration is designed by in situ polymerization of poly (pyrrole-co-aniline) onto PVA/PEG gel electrolyte to achieve exceptional electrochemical performance. This all-in-one configuration can maintain fast charge-carrier transportation and good structural stability. The resulting device shows a large specific capacitance of 773 mF cm−2 at the current density of 0.2 mA cm−2, excellent energy density (54 μWh cm−2) and power density (100 μW cm−2). Under different bending angles or 1000 bending cycles, the capacitance of the device is maintained at 100% which owing to the all-in-one configuration can overcome the relative displacement and avoid the loss of electroactive materials from gel electrolytes when the device is bent. These findings present potential applications in flexible, wearable and smart energy storage devices.

In order to control heat and smoke release of the intumescent flame retardant (IFR) epoxy coating on steel during fire hazard, a little amount of zirconium nitride (ZrN) of 1～3 wt% was introduced into the coating. The back temperature test showed it used about 46.1 min for the steel plate coated with IFR coating without ZrN to reach 580 °C, however by using of 3 wt% ZrN, the time was prolonged to 61 min, indicating the steel structure can be kept for more than 15 min. The result is very important to the safety of steel structure, meaning more escape time during a fire hazard. Furthermore in cone test, the coating containing ZrN exhibited more control on heat and smoke release. For example, compared with the IFR coating containing no ZrN, coating containing 3 wt% ZrN cut more than 20.3% total heat release (THR) and 40.0% smoke production (SPR). The graphitization degree increase of char was documented by Raman spectrum; and in XRD patterns some special peaks of ZrP2O7 and Ti0.8Zr0.2P2O7 was found in char, all the results indicated ZrN participated into the charring with IFR and TiO2 together and then promote formation of more compact char structure.

The ordered mesoporous carbon composite functionalized with carboxylate groups and iron oxide nanoparticles (Fe/OMC) was successfully prepared and used to adsorb 2,4-dichlorophenoxyacetic acid (2,4-D) from wastewater. The resultant adsorbent possessed high degree of order, large specific surface area and pore volume, and good magnetic properties. The increase in initial pollutant concentration and contact time would make the adsorption capacity increase, but the pH and temperature are inversely proportional to 2,4-D uptake. The equilibrium of adsorption was reached within 120 min, and the equilibrated adsorption capacity increased from 99.38 to 310.78 mg/g with the increase of initial concentration of 2,4-D from 100 to 500 mg/L. Notablely, the adsorption capacity reached 97% of the maximum within the first 5 min. The kinetics and isotherm study showed that the pseudo-second-order kinetic and Langmuir isotherm models could well fit the adsorption data. These results indicate that Fe/OMC has a good potential for the rapid adsorption of 2,4-D and prevention of its further diffusion.

BiPO4/BiOBr p–n junction photocatalysts were successfully synthesized via a facile one-pot solvothermal method. The products were characterized by XRD, FE-SEM, HRTEM, XPS, DRS, PL and EIS. The obtained BiPO4/BiOBr composites were constructed by inlaying BiPO4 nanoparticles into BiOBr hierarchical microspheres. Compared with BiPO4 and BiOBr, they exhibited significantly enhanced visible light photocatalytic activity towards the degradation of Rhodamine B (RhB). Among them, 10% BiPO4/BiOBr showed the maximum value of the activity, whose degradation rate was about three times higher than that of pure BiOBr. The enhanced photocatalytic activity could be attributed to the formation of the BiPO4/BiOBr p–n junction, which resulted in the effective separation and transfer of photogenerated electron–hole pairs. Moreover, the trapping experiments confirmed that O2− and h+ were the main active species responsible for the degradation of RhB.

In this study, a novel nitrogen-functionalized magnetic ordered mesoporous carbon (N-Fe/OMC) with uniform pore size (3.8 nm) and excellent magnetic property (8.46 emu/g) was fabricated through simple impregnation then polymerization and calcination. The resultant adsorbent exhibited more preferential sorption toward Pb(II) and phenol than simple equivalent mixture of magnetic ordered mesoporous carbon (Fe/OMC) and pristine ordered mesoporous carbon (OMC). Binary adsorption showed that the coexistence of Pb(II) and phenol at low concentrations would slightly accelerate their jointly adsorption because of partial complexation between Pb(II) and phenol. While at high concentrations, Pb(II) adsorption would be inhibited in relation to the competition from phenol, but phenol adsorption was scarcely affected due to the directly phenol molecular adsorption pattern. Pb(II) adsorption was more suitable in alkaline solution and affected by ionic strength on account of electrostatic interaction, whereas phenol adsorption was better in neutral pH and hardly interfered by ionic strength as the adsorption was a physical combination process. Thermodynamics indicated that the uptakes of Pb(II) and phenol were endothermic and exothermic processes, respectively. Moreover, N-Fe/OMC could be regenerated effectively and recycled by using dilute NaOH and acetone solutions. These superior properties demonstrate that N-Fe/OMC is attractive for practical applications in treatment of water contamination by Pb(II) and phenol.

It is necessary for estrogen to activate mouse blastocysts, so that they can attach to endometrial epithelium in implantation and in our previous research, we have proved estrogen can induce a fast increase in intracellular calcium of mouse blastocysts through acting on G protein-coupled receptor 30 (GPR30), which further promotes their implantation. Moreover, there has been evidence that cytoskeletal proteins are involved in integrin-mediated adhesion of many kinds of cells, which also plays an important role in implantation. To prove estrogen induces rapidly the changes of cytoskeletal proteins in mouse blastocysts and its roles in implantation, we first used immunofluorescence staining and laser confocal microscopy to investigate the fast effect of estrogen on the expression and localization of cytoskeletal proteins in mouse blastocysts. Second, we used electroporation associated with RNA interference to knock down one of the important cytoskeletal proteins, talin, in the mouse blastocyst cells to investigate the fast effect of estrogen on the localization of integrins and the binding activity of integrins with their ligand fibronectin (FN). At last, mouse blastocysts with different treatments were cultured with FN or uterine epithelial cell line Ishikawa in vitro, respectively, and transferred into the bilateral uterine horns of recipient mice, to study the role of the fast effect of estrogen on cytoskeletal proteins in blastocysts adhesion and implantation. Our results indicated that estradiol (E2), E2 conjugated with bovine serum album (E2-BSA) and G-1 (a GPR30-specific agonist) could induce cytoskeletal protein talin, vinculin, and actin to cluster in the mouse blastocysts, while G15 (a GPR30-specific antagonist) and BAPTA (a calcium chelator) may block this effect induced by E2-BSA. Furthermore, E2-BSA could induce the clustering and relocalization of integrin β1 and β3 and increase the FN-binding activity of integrins in blastocyst cells, while E2-BSA could not induce these effects in the blastocysts pretreated with talin-small interfering RNA (siRNA). Meanwhile, the adhesion rate and implantation rate of blastocysts pretreated with talin-siRNA were significantly lower than those pretreated with control-siRNA. We provided the first evidence that the fast effect of estrogen might cause the clustering of the cytoskeletal proteins in mouse blastocyst cells and further induce the changes of localization and functional activity of integrins in the blastocyst cells, which play important roles in blastocyst implantation.

The fabrication and evaluation of a glassy carbon electrode (GCE) modified with ordered mesopo- rous carbon (OMC), 2-mercaptoethanesulfonate (MES)- tethered polyaniline (PANI) and bismuth for simultane- ous determination of trace Cd 2 + and Pb 2 + by differential pulse anodic stripping voltammetry (DPASV) are pre- sented here. The morphology and electrochemical proper- ties of the fabricated electrode were respectively charac- terized by scanning electron microscopy (SEM) and elec- trochemical impedance spectroscopy (EIS). Experimental parameters such as PANI disposition, preconcentration potential, preconcentration time and bismuth concentra- tion were optimized. Under optimum conditions, the fab- ricated electrode exhibited linear calibration curves ranged from 1 to 120 nM for Cd 2 + and Pb 2 + . The limits of detection (LOD) were 0.26 nM for Cd 2 + and 0.16 nM for Pb 2 + (S/N = 3), respectively. Additionally, repeatabili- ty, reproducibility, interference and application were also investigated, and the proposed electrode exhibited excel- lent performance. The proposed method could be extend- ed for the development of other new sensors for heavy metal determination.

Cobalt nanoparticles-embedded magnetic ordered mesoporous carbon (Co/OMC), prepared through a simple method involving infusing and calcination, was used as a highly effective adsorbent for rhodamine B (Rh B) removal. Several techniques, including SEM, HRTEM, nitrogen adsorption–desorption isotherms, XRD, Raman spectra, EDX, zeta potential and VSM measurement, were applied to characterize the adsorbent. Batch tests were conducted to investigate the adsorption performance. The adsorption capacity of the resultant adsorbent was relatively high compared with raw ordered mesoporous carbon (OMC) and reached an equilibrium value of 468 mg/g at 200 mg/L initial Rh B concentration. Removal efficiency even reached 96% within 25 min at 100 mg/L initial Rh B concentration. Besides, the adsorption amount increased with the increase of solution pH, adsorbent dose and initial Rh B concentration. Kinetics study showed that the adsorption agreed well with pseudo-second-order model ( R 2 = 0.999) and had a significant correlation with intra-particle diffusion model in the both two adsorption periods. Furthermore, thermodynamics research indicated that the adsorption process was endothermic and spontaneous in nature. The adsorption isotherms fitted well with Langmuir model, demonstrating the formation of mono-molecular layer on the surface of Co/OMC during adsorption process. The results confirmed that Co/OMC has the potential superiority in removal of Rh B from aqueous solution.

A biosensor based on tyrosinase immobilized with ordered mesoporous carbon–Au (OMC–Au), L-lysine membrane and Au nanoparticles (tyrosinase/OMC–Au/L-lysine/Au) was combined with artificial neural networks (ANNs) for the simultaneous determination of catechol (CC) and hydroquinone (HQ) in compost bioremediation of municipal solid waste. The good performance of biosensor provided the potential applicability for the simultaneous identification and quantification of catechol and hydroquinone in real samples, and the combination with ANNs offered a good chemometric tool for data analysis in respect to the dynamic, nonlinear, and uncertain characteristics of the complex composting system. Good prediction ability was attained after the ANNs model optimization, and the direct detection range for catechol and hydroquinone were directly analyzed by the ANNs model and varied between 1.0 × 10−7 and 1.1 × 10−4 M, significantly extended compared to the linear model (4.0 × 10−7 to 8.0 × 10−5 M). Finally, the performance of the ANNs model was compared with the linear regression model. The results demonstrate that the prediction results by the ANNs model are more precise than those by the linear regression, and the latter was far from accurate at high levels of catechol and hydroquinone beyond the linear range. All the results show that the combination of the biosensor and ANNs is a rapid and sensitive method in the quantitative study of composting system.

Today, silicon material plays an irreplaceable role in microelectronic of the information industry, however it don`t have a good emission characteristics. In order to explore the emission character, we calculated the electrons structure, absorbance of silicon doped with C, Si, Ge, Sn and Pb by the first-principles methods.

The binding energy, electronic structure and optical properties of ultrathin single-layer silicon nanosheets passivated with H-, H3C-, H2-N and HS-cluster were calculated using density functional theory based on plane-wave ultra-soft pseudopotential respectively. Firstly, the most stable configuration was selected from passivated configurations according to the lowest energy principle after calculating their total energies. Secondly the density of state and the band structure of the different passivated systems were calculated. It was found that different passivation clusters could affect the forbidden band, furthermore the passivated HS-cluster could notably decrease the width of forbidden band through electron transfer. Finally, the light absorption and reflection properties were also investigated. All results were conducive to the development of silicon-based optoelectronic devices.

In this article, the selenium content of selenium polysaccharide and its antioxidant activity in vitro in Artemisia argyi has been studied. The double tracts atomic fluorescence spectrometry is used to detect the total selenium content in the sample and that of selenium polysaccharide in the active ingredient of the sample. The salicylic acid method and pyrogallol autoxidation method are used to detect the scavenging activity of selenium polysaccharide on hydroxyl radicals and superoxide anion. which grows in Yutangba, a selenium mining area of Enshi—“City of Selenium in China”. Through a comparative experiment with Artemisia argyi growing in non-selenium mining areas, the results have shown that the antioxidant ability of selenium polysaccharide in Se-enriched Artemisia argyi is significantly stronger than that of pure polysaccharide. Therefore, Se-enriched Chinese herbal medicine is a good natural antioxidant, which is worthy of exploitation and utilization.

Metallothionein (MT) has a characteristic molecular structure with a cysteine-rich content. This unique structure provides metal-binding and redox capabilities and promoting metal homeostasis and detoxification in living animals. In order to evaluate the effects of cadmium (Cd) on hepatic MT expression in the liver of Acrossocheilus fasciatus, we obtained the complete cDNA of the A. fasciatus liver MT for the first time. The MT cDNA contains a 605-bp sequence, which codes for 60 amino acids. Protein alignment showed that the similarity between MT protein sequences of A. fasciatus and those of other vertebrates (especially teleosts) was very high and a cysteine residue structure was also conserved. MT was detected in the liver, kidney, gill, testis, muscle, spleen, heart and brain tissues of A. fasciatus by tissue-specific expression analysis. After Cd exposure, Cd/hemoglobin saturation assay, immunohistochemistry and reverse-transcription quantitative PCR (RT-qPCR) were used to describe MT expression in liver tissue. These techniques indicate a sensitive response by liver MT to Cd exposure. The results suggest that A. fasciatus MT may play an important role in the detoxification processes in the liver, and also would be a useful biomarker for monitoring metal pollution in aquatic environments. In addition, A. fasciatus could be regarded as one candidate for a model species for bony fishes in ecotoxicology.

Short running title: Pseudosciaena crocea semen after cryopreservation Abstract The cryopreservation and additive's effects on the plasma membrane stability, motility, enzyme activity, membrane lipid composition, and ultrastructural injury of the sperm of Pseudosciaena crocea, sperm were analysed. The results indicated that the addition of trehalose (TH) and bovine serum albumin (BSA) provided significantly better results in the motility test than sucrose. In addition, the following BSA groups, especially the 3 g/L BSA and 8.56 g/L TH+3 g/L BSA groups, showed significantly increased semen motility. The 8.56 g/L TH, 0.5 g/L TH+3 g/L BSA, 8.56 g/L TH+3 g/L BSA, and 17.12 g/L TH+2 g/L BSA groups showed the most effective enzyme activity. There were no significant differences between the cholesterol (CHO) composition for fresh sperm and cryopreserved sperm stored in 3 g/L BSA or 8.56 g/L TH+3 g/L BSA. Ultrastructural injury mainly included a damaged membrane, lost mitochondria, or broken flagella, whereas the majority of the freeze-thawed sperm remained morphologically normal. In conclusion, the addition of 3 g/L BSA and 8.56 g/L TH+3 g/L BSA significantly increased semen quality.