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Earphones are often exported to foreign countries by sea as consumer goods. In view of the humid marine environment, the earphone packaging box is often placed with anti-mold chips to prevent mold, while the volatilization of the anti-mold chips will also cause corrosion problems. In this study, a large number of aluminum earphone connectors were corroded in the process of ocean transportation, and the corrosion products were located in the left earphone connector close to the anti-mold chips. It’s determined that sulfate and nitrate ions lead to the corrosion of the aluminum connectors, and these are the volatilization products of the anti-mold chips. This conclusion was further confirmed by the simulation test, which was carried out on the anti-mold chips and aluminum connectors at 85 °C, 85% RH humidity for 72 h. The aluminum connectors were obviously corroded, and the morphology and composition of the corrosion products were the same as those on the actual earphones. The corrosion was successfully prevented by a PTFE coating on the surface of aluminum connectors. Keywords: Earphones; Anti-mold chip; Aluminum; Corrosion; PTFE coating

This research investigated a synthetic amendment to improve composting and resource recycling of pig manure and biogas residue. We further examined whether adding a synthetic amendment impacts the microbial ecosystem in the composted materials. Three mixing ratios were used to investigate composting performance: no synthetic amendment (T0), 5% synthetic amendment (T1), and 10% synthetic amendment (T2) (T1 and T2 were measured as a wet weight ratio). There were no significant differences in the fundamental characteristics between composting products in T0 and T1. The moisture content of composting material in T0, T1, and T2 significantly decreased from a baseline of approximately 65% to 35.5%, 37.3%, and 55.9%, respectively. Meanwhile, the germination index significantly increased to 111.6%, 155.6%, and 62.3%, respectively. When an optimal proportion of synthetic amendment was added, T1 showed high degree of humification, lignocellulase activities, and effective biodegradation. Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant bacteria, while Ascomycota and Basidiomycota were the dominant fungi in all treatment groups. Amino sugar and nucleotide sugar metabolism, glycolysis, starch, and sucrose metabolism were among the primary pathways in predicted functions. The synthetic amendment can generate a mature composting product and can be reused or recycled to conserve resources.

We present a controllable terahertz (THz) metamaterial switch by manipulating toroidal dipolar mode in simulation. The metamaterial switch consists of periodically patterned metallic split rings with photosensitive silicon stripes. The excitation of toroidal dipolar resonance is closely dependent on the transition between the dielectric and conductive phases of photosensitive silicon. The toroidal dipolar mode is exploited to modulate the ON/OFF-switching transmission of THz wave under wide incident angles. The operation mechanism and frequency tunability are discussed.

The effect of lead on the catalytic performance of Mn-Ce/TiO2 catalysts in the selective catalytic reduction (SCR) of NOx with ammonia at low temperature was investigated; with the help of nitrogen sorption, XRD, FT-IR spectroscopy, H2-TPR and NH3-TPD characterization, the causes of lead poisoning and acid regeneration were clarified. The results indicate that the doping of Pb in Mn-Ce/TiO2 leads to a significant decrease of the low-temperature SCR activity; with a Pb loading of 11%, the conversion of NO over Mn-Ce/TiO2 at 180°C decreases from original 100% on the fresh catalyst to 44% on the Pd-poisoned catalyst. The presence of Pb may reduce the content of active Mn4+ and Ce3+ species on the Mn-Ce/TiO2 catalyst, which suppresses the redox cycle of Mn4+ + Ce3+ ↔ Mn3+ + Ce4+; moreover, the decrease of surface acidity on the Mn-Ce/TiO2 catalyst by the doping of Pb is also disadvantageous to the adsorption and activation of NH3. The Pd-poisoned Mn-Ce/TiO2 can be regenerated by nitric acid treatment; after the regeneration, the catalytic activity of Mn-Ce/TiO2 in NH3-SCR of NO is almost completely recovered and even exceeds that of the fresh catalyst at 80–150°C. The nitric acid treatment can restore the redox capacity of Mn-Ce/TiO2, increase the surface area, and create new acid sites, which contribute to recovery of the activity of Pb-poisoned Mn-Ce/TiO2 catalyst in NH3-SCR.

In order to evaluate the effect of blood glucose concentration on the reliability of AZ31 magnesium alloy medical implant, the corrosion of AZ31 alloy was studied in a simulated physiological saline solution. It is found that when the glucose concentration is in the normal range of ca. 1 g/L, the corrosion of AZ31 alloy can be inhibited. However, when the glucose concentration becomes higher like that of diabetic patients, the degradation of AZ31 alloy is significantly accelerated. Therefore, for diabetic patients, the change in glucose concentration must be taken into consideration in order to ensure the reliability of AZ31 medical implants.

Background Cachexia, a syndrome of muscle atrophy, adipose loss, and anorexia, is associated with reduced survival in cancer patients. The colon adenocarcinoma C26c20 cell line secretes the cytokine leukaemia inhibitory factor (LIF), which induces cachexia. We characterized how LIF promotes cachexia‐associated weight loss and anorexia in mice through Janus kinase (JAK)‐dependent changes in adipose and hypothalamic tissues. Methods Cachexia was induced in vivo with the heterotopic allotransplanted administration of C26c20 colon adenocarcinoma cells or the intraperitoneal administration of recombinant LIF in the absence or presence of JAK inhibitors. Blood, adipose, and hypothalamic tissues were collected and processed for cytokine/adipokine enzyme‐linked immunosorbent assays, immunoblot analysis, and quantitative reverse transcription polymerase chain reaction (RT‐PCR). Cachexia‐associated lipolysis was induced in vitro by stimulating differentiated adipocytes with recombinant LIF or interleukin (IL)‐6 in the absence or presence of lipase or JAK inhibitors. These adipocytes were processed for glycerol release into the media, immunoblot analysis, and RT‐PCR. Results Tumour‐secreted LIF induced changes in adipose tissue expression and serum levels of IL‐6 and leptin in a JAK‐dependent manner influencing cachexia‐associated adipose wasting and anorexia. We identified two JAK inhibitors that block IL‐6 family‐mediated adipocyte lipolysis and IL‐6 induction using an in vitro cachexia lipolysis assay. JAK inhibitors administered to the in vivo C26c20 cancer cachexia mouse models led to (i) a decrease in signal transducer and activator of transcription 3 phosphorylation in hypothalamic and adipose tissues, (ii) a reverse in the cachexia serum cytokine/adipokine signature, (iii) a delay in cancer cachexia‐associated anorexia and adipose loss, and (iv) an improvement in overall survival. Conclusions JAK inhibitors suppress LIF‐associated adipose loss and anorexia in both in vitro and in vivo models of cancer cachexia.

Deoxynivalenol (DON) or “vomitoxin” is a mycotoxin produced by Fusarium species. Few food poisoning cases caused by DON have been reported since the 1990s in China. However, on May 16, 2019, the Zh...

In this work, we design and construct a graphitic/amorphous heterophase porous carbon with a lotus-leaf-like surface microstructure via using cellulose paper as a single carbon source. The results ...

It is still a big challenge to develop active, stable, and easy-to-make bifunctional non-noble electrocatalysts for upshifting overall urea-assisted water splitting toward practical environmental a...

The occurrence of stress is unavoidable in the process of livestock production, and prolonged stress will cause the decrease of livestock productivity. The stress response is mainly regulated by the hypothalamic-pituitary-adrenal axis (HPA axis), which produces a large amount of stress hormones, namely glucocorticoids (GCs), and generates a severe impact on the energy metabolism of the animal body. It is reported that m6A modification plays an important role in the regulation of stress response and also participates in the process of muscle growth and development. In this study, we explored the effect of GCs on the protein synthesis procession of porcine skeletal muscle cells (PSCs). We prove that dexamethasone affects the expression of SLC7A7, a main amino acid transporter for protein synthesis by affecting the level of m6A modification in PSCs. In addition, we find that SLC7A7 affects the level of PSC protein synthesis by regulating the conduction of the mTOR signaling pathway, which indicates that the reduction of SLC7A7 expression may alleviate the level of protein synthesis under stress conditions.

We prospected a novel arylesterase LggEst from the probiotics Lacticaseibacillus rhamnosus GG by genome mining strategy, and characterized the enzymatic properties in detail. Biochemical characterization revealed that arylesterase LggEst presented high activity at a wide range of temperatures from 25 to 65 °C with maximum activity at 50 °C. LggEst maintained high activity in the pH range from 5.5 to 7.5 with optimum pH of 6.5. LggEst might efficiently hydrolyze a series of aryl substrates p-nitrophenyl esters with different acyl chain lengths. LggEst displayed the Vmax from 2.8 to 77.3 μmol min−1 mg−1 protein and the kcat from 1.8 to 48.8 s−1 with the highest catalytic activity on pNPC6. The KM of LggEst on different substrates varied significantly from 4.9 μM to 5.6 mM with the highest affinity on pNPC10. LggEst exhibited the preference for medium- and long-chain p-nitrophenyl esters. LggEst showed remarkable thermostability at 45 °C. LggEst could be tolerant of several organic solvents at the concentration of 10% and DMSO and methanol at the concentration of 20%. Catalytic activity of LggEst was improved by 12% in the presence of 20% ethylene glycol. LggEst was resistant to high concentrations of sodium citrate and sodium chloride. Notably, enzymatic activity of LggEst was significantly enhanced in the presence of 0.1% sodium deoxycholate at high temperatures.

To investigate the formation mechanism of the dendrites glass-ceramics and the effect of TaB2 modifier on the oxidation-inhibition ability of Si-based coatings in aerobic environment with broad temperature region for carbon materials, the Si-based coatings modified with different TaB2 content were fabricated by the liquid phase sintering method. The fabricated coatings and its corresponding composite powders were investigated in dynamic TG aerobic environments up to 1500 ℃. The initial oxidation temperatures of Si-based coatings modified with TaB2 powders are almost completely suppressed to 800 ℃. With the increase of TaB2 phase content, the relative oxygen permeability of the Si-based coatings is significantly reduced, which can be interpreted as the generation of liquid boride, silicide and Ta-Si-B-O compound glass ceramics those can improve the stability of the coating. The formation mechanism of the dendrites glass-ceramics was illustrated.

In aquatic fields, ammonium (NH4+) is the most preferred nitrogen (N) source used by plants. The uptake of NH4+ is facilitated by the family of ammonium transporters (AMTs). However, the molecular functions of AMTs in aquatic plants are largely unknown. In this work, a new NH4+ transporter encoding gene, ApAMT1;1, was isolated from the typical aquatic plant alligatorweed, using degenerated primers and rapid amplification of cDNA end (RACE) techniques. Quantitative real time PCR showed that ApAMT1;1 was predominantly expressed in roots, and significantly induced by NH4+ starvation in all tested tissues, including leaves, stems and roots. Functional determination and 15N-labeled ammonium uptake assays in yeast cells indicated that ApAMT1;1 was a typical high-affinity transporter, with a 38.6 μM Km value, and the phosphorylation site T469 was required to retain its NH4+ uptake capacity. Further analyses with Met sulfoximine (MSX), a NH4+ assimilation inhibitor, demonstrated that ApAMT1;1-mediated NH4+ uptake might be feedback regulated by the internal NH4+ accumulation. Our results reveal a functional role of ApAMT1;1 in the uptake and transport of NH4+ in aquatic plants.

Various types of fuel cells as clean and portable power sources show a great attraction, especially direct methanol fuel cells (DMFCs) having high energy density and convenient fuel storage. In this paper, PtNi bimetallic nanoparticles (NPs) supported on the electrochemically reduced porous graphene oxide (ERPGO) was fabricated by one-step electrochemical reduction of the mixture of H2PtCl6, NiSO4 and porous graphene oxide (PGO). The obtained hybrid of PtNi/ERPGO was investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Furthermore, the electrocatalytic activity for methanol oxidation reaction (MOR) was evaluated by electrochemical method. The experimental results have demonstrated that PtNi/ERPGO enhanced electrocatalytic activity, which might be attributed to the bifunctional mechanism and the existence of unique pore structure on the surface of graphene sheets.

A double interlacing metal–organic framework (MOF), formula of [(Zn4O)2(PDDA)6(H2O)2]·10DMF (1), with pcu-topology has been successfully assembled by Zn4O inorganic clusters and a V-shaped ligand 4...

Type III CRISPR-Cas systems code for a multi-subunit ribonucleoprotein (RNP) complex that mediates DNA cleavage and synthesizes cyclic oligoadenylate (cOA) second messenger to confer anti-viral immunity. Both immune activities are to be activated upon binding to target RNA transcripts by their complementarity to crRNA, and autoimmunity avoidance is determined by extended complementarity between the 5ʹ-repeat tag of crRNA and 3ʹ-flanking sequences of target transcripts (anti-tag). However, as to how the strategy could achieve stringent autoimmunity avoidance remained elusive. In this study, we systematically investigated how the complementarity of the crRNA 5ʹ-tag and anti-tag (i.e., tag complementarity) could affect the interference activities (DNA cleavage activity and cOA synthesis activity) of Cmr-α, a type III-B system in Sulfolobus islandicus Rey15A. The results revealed an increasing suppression on both activities by increasing degrees of tag complementarity and a critical function of the 7(th) nucleotide of crRNA in avoiding autoimmunity. More importantly, mutagenesis of Cmr3α exerts either positive or negative effects on the cOA synthesis activity depending on the degrees of tag complementarity, suggesting that the subunit, coupling with the interaction between crRNA tag and anti-tag, function in facilitating immunity and avoiding autoimmunity in Type III-B systems.

Here, a unique triple-layered core-shell structure (Au@N-CQDs@Pt) with an Au metal core, nitrogen-doped carbon quantum dots interlayer, and metal Pt outside shell was obtained by chemical reduction of HAuCl4 and H2PtCl6 in the presence of N-CQDs. The remarkable advantage of the method reported here is no any stabilizer or surfactant agent involved. The results of transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS) reveal that the as-prepared nanocomposites exhibit the nanostructured dendritic Pt and the quantity of Pt shell can be easily changed through controlling the synthesis time. Specifically, Au@N-CQDs@Pt displays excellent catalytic activity toward methanol oxidation reaction in alkaline condition than Au-Pt without N-CQDs, which indicate the useful application of CQDs in designing new catalysts to be used in direct methanol fuel cells.

Amino acids can affect protein synthesis by activating mammalian target of rapamycin complex 1 (mTORC1) signaling pathway. Amino acid transporters SLC38A9 on the lysosomal membrane not only transport amino acids, but also can sense amino acids and activate mTORC1 signaling pathway. Activating transcription factor 4 (ATF4) can promote the expression of amino acid transporters by binding with amino acid response element (AARE). In this study, two AAREs were found in the SLC38A9 promoter region of pig, and both of them bound to ATF4. The AARE in the first intron was located in the core promoter region of SLC38A9. ATF4 regulated mRNA expression level of SLC38A9 in porcine skeletal muscle cells. In the absence of amino acids, the expression of ATF4 decreased and the expression of SLC38A9 increased. After leucine addition, the expression levels of ATF4 and SLC38A9 increased. It suggested that in the absence of amino acids, the expression of SLC38A9 was increased via binding of ATF4 to AARE binding factors in SLC38A9 promoter fragment; after the addition of leucine, ATF4 was activated, resulting in the increase of SLC38A9 expression.

Genome-wide association studies have identified that NPR-C (natriuretic peptide receptor-C) variants are associated with elevation of blood pressure. However, the mechanism underlying the relationship between NPR-C and blood pressure regulation remains elusive. Here, we investigate whether NPR-C regulates Ang II (angiotensin II)-induced hypertension through sodium transporters activity. Wild-type mice responded to continuous Ang II infusion with an increased renal NPR-C expression. Global NPR-C deficiency attenuated Ang II–induced increased blood pressure both in male and female mice associated with more diuretic and natriuretic responses to a saline challenge. Interestingly, Ang II increased both total and phosphorylation of NCC (NaCl cotransporter) abundance involving in activation of WNK4 (with-no-lysine kinase 4)/SPAK (Ste20-related proline/alanine-rich kinase) which was blunted by NPR-C deletion. NCC inhibitor, hydrochlorothiazide, failed to induce natriuresis in NPR-C knockout mice. Moreover, low-salt and high-salt diets–induced changes of total and phosphorylation of NCC expression were normalized by NPR-C deletion. Importantly, tubule-specific deletion of NPR-C also attenuated Ang II–induced elevated blood pressure, total and phosphorylation of NCC expression. Mechanistically, in distal convoluted tubule cells, Ang II dose and time-dependently upregulated WNK4/SPAK/NCC kinase pathway and NPR-C/Gi/PLC/PKC signaling pathway mediated NCC activation. These results demonstrate that NPR-C signaling regulates NCC function contributing to sodium retention-mediated elevated blood pressure, which suggests that NPR-C is a promising candidate for the treatment of sodium retention-related hypertension.

A new potentiometric sensor based on modified carbon paste electrode (CPE) was prepared for the sensitive and selective detection of total residual chlorine (TRC) in simulated electrolytically-treated ballast water (BW). The modified CPE was prepared using ferrocene (Fc) as the sensing species and paraffin oil as the binder. It is revealed that the addition of Fc can significantly shorten the response time and improve the reproducibility, selectivity, and stability of the sensor. The open circuit potential of the Fc-CPE is in linear proportion to the logarithm of TRC within the TRC concentration range from 1 mg∙dm−3 to 15 mg∙dm−3. In addition, the Fc-CPE sensor exhibits good selectivity to TRC over a wide concentration range of the possible co-exiting interference ions in seawater. The Fc-CPE electrode can be used as a convenient and reliable sensor for the continuous monitoring of TRC during the electrolytic treatment of BW.

Biodrying in conjunction with compound stone amendment was used to treat kitchen waste, which improved biodrying. After 16 days, the pile moisture content decreased from 68.8% to 23.0%. Lignin, cellulose and hemicellulose concentrations decreased from 104.6 mg g−1 d.b., 322.9 mg g−1 d.b. and 155.9 mg g−1 d.b., respectively, to 74.0 mg g−1 d.b., 224.8 mg g−1 d.b. and 134.5 mg g−1 d.b., respectively. The Shannon index for bacteria increased from 2.5 to 3.1, while for fungi, it decreased from 4.6 to 0.6. The relative abundances of Amino Acid Metabolism and Carbohydrate Metabolism exceeded 7%. The thermophilic phase during the process inactivated the pathogenic microorganisms, increased the bacterial diversity, decreased the fungal diversity, and potentially improved the metabolism of nutrients, including amino acids, carbohydrates, lipids and vitamins. The biomarker analysis and predicated protein sequences provide genetic evidence to elucidate why the thermophilic phase is the peak time for nutrient metabolism.

Summary The role of chronic adipose inflammation in diet-induced obesity (DIO) and its sequelae including fatty liver disease remains unclear. Leukemia inhibitory factor (LIF) induces JAK-dependent adipocyte lipolysis and altered adipo/cytokine expression, suppressing in vivo adipose expansion in normal and obese mouse models. To characterize LIF receptor (LIFR-α)-dependent cytokine signaling in DIO, we created an adipocyte-specific LIFR knockout mouse model (Adipoq-Cre;LIFRfl/fl). Differentiated adipocytes derived from this model blocked LIF-induced triacylglycerol lipolysis. Adipoq-Cre;LIFRfl/fl mice on a high-fat diet (HFD) displayed reduced adipose STAT3 activation, 50% expansion in adipose, 20% body weight increase, and a 75% reduction in total hepatic triacylglycerides compared with controls. To demonstrate that LIFR-α signals adipocytes through STAT3, we also created an Adipoq-Cre;STAT3fl/fl model that showed similar findings when fed a HFD as Adipoq-Cre;LIFRfl/fl mice. These findings establish the importance of obesity-associated LIFR-α/JAK/STAT3 inflammatory signaling in adipocytes, blocking further adipose expansion in DIO contributing to ectopic liver triacylglyceride accumulation., Graphical abstract, Highlights • LIFR-α signaling induces adipocyte lipolysis, restricting adipose expansion in DIO • LIFR-α signaling requires STAT3 for adipocyte lipolysis • LIFR-α/JAK/STAT3 lipolysis signaling in adipocytes promotes hepatic steatosis, Biological Sciences ; Animal Physiology ; Cellular Physiology ; Endocrinology ; Cell Biology

The effect of pyrolytic carbon (PyC) thickness on the tensile property of mini T800-carbon fiber reinforced SiC matrix composites (mini-C/SiC) was studied in this work. PyC interphase was prepared by chemical vapor infiltration (CVI) process using C3H6-Ar as gas source, and the PyC thickness was adjusted from 0 to 400 nm, then the SiC matrix was prepared by CVI process using methyltrichlorosilane (MTS)-H2-Ar as precursor and gas source. The results showed that the tensile strength of mini-C/SiC increased first and then decreased with the increase of the PyC thickness. When the thickness of PyC was 100 nm, the average strength reached the maximum value of 393±70 MPa. The Weibull modulus increased from 2.0 to 8.06 with the increase of PyC thickness, the larger the Weibull modulus, the smaller the dispersion, which indicated that the regulation of PyC thickness is conducive to improve tensile properties.

The aroma of peach fruit is predominantly determined by the accumulation of γ-decalactone and ester compounds. A previous study showed that the biosynthesis of these aroma compounds in peach fruit is catalyzed by PpAAT1, an alcohol acyltransferase. In this work, we investigated the key active site residues responsible for γ-decalactone and ester biosynthesis. A total of 14 candidate amino acid residues possibly involved in internal esterification and 9 candidate amino acid residues possibly involved in esterification of PpAAT1 were assessed via site-directed mutagenesis. Analyses of the in vitro enzyme activities of PpAAT1 and its site-directed mutant proteins (PpAAT1-SMs) with different amino acid residue mutations as well as the contents of γ-decalactone in transgenic tobacco leaves and peach fruits transiently expressing PpAAT1 and PpAAT1-SMs revealed that site-directed mutation of H165 in the conserved HxxxD motif led to lost enzymatic activity of PpAAT1 in both internal esterification and its reactions, whereas mutation of the key amino acid residue D376 led to the total loss of γ-decalactone biosynthesis activity of PpAAT1. Mutations of 9 and 7 other amino acid residues also dramatically affected the enzymatic activity of PpAAT1 in the internal esterification and esterification reactions, respectively. Our findings provide a biochemical foundation for the mechanical biosynthesis of γ-decalactone and ester compounds catalyzed by PpAAT1 in peach fruits, which could be used to guide the molecular breeding of new peach species with more favorable aromas for consumers.

Steam reforming of toluene, a model tar compound, was carried out at low temperature of 600 °C using Cu–Ni and Fe–Ni bimetallic catalysts with different molar ratios supported on activated carbon (AC). For the Cu–Ni/AC catalysts, the carbon conversion of toluene rose and then decreased with the content of Cu increasing, and the best performance was achieved at the molar ratio of 0.2. However, the Fe–Ni/AC catalyst with the optimum composition of Fe/Ni = 0.1 had a better catalytic performance for toluene steam reforming than the Cu–Ni/AC catalyst (Cu/Ni = 0.2). During the duration test of 20 h, the Fe–Ni/AC (Fe/Ni = 0.1) catalyst showed higher activity for the average carbon conversion of toluene (93.8% vs. 92.9%) and better resistance. to carbon deposition than those of Ni/AC catalyst. Moreover, the metal average sizes of the spent Ni/AC and 0.1-Fe–Ni/AC were estimated to be 30.0 nm and 19.0 nm, respectively. Based on a variety of physiochemical characterization results, it is demonstrated that the addition of iron into Ni/AC catalyst led to good dispersion of Ni, and few coke formation and limited aggregation of nickel particles during reaction.

A series of AuPd/C catalysts were prepared and tested for the first time for active and stable dehydrogenation of a formic acid–ammonium formate (FA–AF) mixture. The catalysts with different Au-to-Pd molar ratios were prepared using a facile simultaneous reduction method and characterized using transmission electron microscopy (TEM), high-resolution TEM, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was found that the catalytic activity and stability of the Au3Pd1/C catalyst was the best. The initial turnover frequency for the dehydrogenation of the FA–AF mixture over the Au3Pd1/C catalyst can reach 407.5 h−1 at 365 K. The reaction order with respect to FA and AF is 0.25 and 0.55, respectively. The apparent activation energy of dehydrogenation is 23.3 ± 1.3 kJ mol−1. The catalytic activity of the Au3Pd1/C catalyst remains ca. 88.0% after 4 runs, which is much better than the single Pd/C catalyst. The mechanism for the dehydrogenation is also discussed.

Large-sized single-crystal two-dimensional (2D) perovskites are highly desirable owing to their fundamental properties and intriguing ability to boost devices. Herein, 2-phenylethylammonium lead bromide [(PEA)2PbBr4] single crystals, which are a violet-light-emitting 2D perovskite material, with typical lateral sizes of about one centimeter were successfully grown using a seeded solution method. The single-crystal plates showed a well-defined shape (rectangle or hexagon), a natural thickness (300–500 μm) similar to that of conventional silicon and InP wafers, a large aspect ratio of ∼20, and a smooth surface (root mean square, ∼0.7 nm). We integrated these single crystal plates into an ultraviolet photodetector, achieving a low dark current of ∼10−13 A and an efficient photoresponse (on/off ratio, ∼103). This experiment could easily be extended to grow freestanding 2D perovskite single crystals on a wafer scale for practical integrated optoelectronics.

Metallic molybdenum disulfide (MoS2) has attracted wide attention owing to its high electrical conductivity and promising application in the electrocatalytic hydrogen evolution reaction (HER). However, it is difficult to realize the scale-up production of thermodynamically metastable metallic MoS2via conventional approaches. Although some research efforts have been devoted to producing metallic MoS2, it is still a challenging task to simultaneously realize metallic phase control and morphological regulation in MoS2. Here, metallic MoS2 with a controllable hierarchical spherical structure has been achieved via a hydrothermal strategy by using carbon nitride (C3N4) nanospheres as a self-sacrificial template. In the crystal growth, C3N4 played an important role in controlling the morphology of MoS2 by serving as the nucleation and growth site. Meanwhile, the decomposed C3N4 acted as an intercalated material which could further stabilize the metallic phase MoS2. Owing to good electroconductibility and unique structure design, metallic phase MoS2 with a hierarchical flower-like architecture exhibits enhanced electrolytic properties for the HER in an acidic medium.

To improve the modification effect of ZrB2 phase on Si-based ceramic coatings in aerobic environment with wider range of temperature, ZrB2 was utilized to modify the SiC coating by the technique of liquid phase sintering. The modification behaviors of ZrB2 phase on oxidation inhibition ability of SiC coating were investigated in wider range of temperature through the TG oxidation tests (room temperature-1773 K). When the synthetic temperature is 1700 °C, pure phase ZrB2 powders were synthesized through the way of carbothermal reduction, the average particle size of which is 531 nm. The SiC coating modified by ZrB2 is comprised of ZrB2 and SiC phases, the thickness of which is about 200 μm. With the modification of ZrB2 phase, the oxidation resistance of the SiC coating is significantly enhanced, especial the temperature region below 1200 °C, leading to the delay of initial mass loss temperature (about 260 °C) and slowing down mass loss rate (reduced by about 67%) in the fastest mass loss area. While the final mass loss of the coated graphite substrate decreased from 18% to 5%. Owing to the formation of the protective B2O3, the fast weight gain temperature region (from 700 °C to 1240 °C) in the TG curve of the ZrB2 powders effectively compensate the weakness of the SiC coating in this temperature region. With the movement of the increasing SiO2 glass layer to cover the surface of the coating, Zr-oxides consisted of ZrO2 and ZrSiO4 were gradually peeled into tiny oxide particles to form Zr-oxides-rings. The refractory Zr-oxides-rings and the unpeeled large Zr-oxides-obstacles construct skeleton inlayed in the SiO2 glass layer, demonstrating the ability of restricting the growth of microcrack, which is responsible for the remarkably enhanced anti-oxidation modification effect of ZrB2 phase.

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.

Recently, Type III-A CRISPR-Cas systems were found to catalyze the synthesis of cyclic oligoadenylates (cOAs), a second messenger that specifically activates Csm6, a Cas accessory RNase and confers antiviral defense in bacteria. To test if III-B CRISPR-Cas systems could mediate a similar CRISPR signaling pathway, the Sulfolobus islandicus Cmr-α ribonucleoprotein complex (Cmr-α–RNP) was purified from the native host and tested for cOA synthesis. We found that the system showed a robust production of cyclic tetra-adenylate (c-A4), and that c-A4 functions as a second messenger to activate the III-B-associated RNase Csx1 by binding to its CRISPR-associated Rossmann Fold domain. Investigation of the kinetics of cOA synthesis revealed that Cmr-α–RNP displayed positively cooperative binding to the adenosine triphosphate (ATP) substrate. Furthermore, mutagenesis of conserved domains in Cmr2α confirmed that, while Palm 2 hosts the active site of cOA synthesis, Palm 1 domain serves as the primary site in the enzyme–substrate interaction. Together, our data suggest that the two Palm domains cooperatively interact with ATP molecules to achieve a robust cOA synthesis by the III-B CRISPR-Cas system.

To investigate the anti-oxidation modification behaviors and mechanisms of the pure HfB2 phase in dynamic aerobic environment, HfB2-SiC coating was prepared through liquid phase sintering method. The average particle size of the synthetic pure phase HfB2 powders is about 335 nm. The TG curve of pure HfB2 powders exhibits excellent anti-oxidation modification ability for Si-based coating. After the modification of HfB2 phase, the anti-oxidation ability of SiC coating achieved prominent improvement. The initiative mass loss temperature of SiC coating lagged by 41.8%, while the percentage of mass loss and rate in fastest mass-loss zone of the SiC coating lagged by 57.6% and 33.3%, respectively. The generated B2O3 is responsible for the obviously improved oxidation resistance below 1200 °C. It compensates the oxidation protection weaknesses of the Si-based ceramic coating in this temperature region. With the fluid of the SiO2 glass layer, the dispersed Hf-oxides were inlaid in it to form the compound Hf-O-Si glass layer. The Hf-oxides heterogeneous phases with ultra-high melting temperature are able to improve the stability of the SiO2 glass layer at ultra-high temperature. It improves the ability of microcracks restriction and reduces the erosion of oxygen to the carbon matrix.

The titanium opaque porcelain was synthesized through sol-gel using borate-silicate system. The porcelain was characterized by DSC-TG, X-ray diffraction, N2 adsorption-desorption isotherms and scanning electron microscope tests. The results of DSC showed that the nitrates could be decomposed completely when the bioglass xerogel precursor was heat-treated at 760 ℃. The XRD results showed that the Na2Ca3Si6O16 was the major phase of the opaque porcelain. The synthesized opaque porcelain powders had an average particle size of about 5–25 µm with nanopores of around 50–70 nm on the surface. The BET average surface area of the porcelain was 12.67 m2/g, while the average pore diameters for adsorption and desorption were 9.73 and 10.16 nm, respectively. The flexure strength significantly increased from 47.4 MPa to 116.2 MPa with the sintering temperature increasing from 575 ℃ to 600 ℃. The XRD, FTIR and EDS results proved that hydroxyapatite had formed on the porcelain surface after incubation in simulated body fluid.

Cold tolerance is the primary limiting factor affecting the quality and productivity of chrysanthemum (Dendranthema morifolium). However, few studies have investigated the molecular mechanisms underlying the low temperature response in chrysanthemum. In the present study, we used RNA-Seq technology to compare the transcript profiles of chrysanthemum leaves exposed to two different temperatures (20 and −8 °C). A total of 13.54 Gb of clean reads were assembled into 71,971 unigenes with an average length of 694 bp, and 33,282 unigenes were annotated identified from five well-known protein databases. Of these, 9579, 24,252, 7123, 22,554, and 32,891 unigenes were separately identified in the COG, GO, KEGG, Swiss-Prot, and NCBI databases, respectively. Differentially expressed genes (1592 upregulated and 718 downregulated) were identified between the control (CK) and low temperature treatment (T) groups. KEGG pathway enrichment analysis identified 20 significantly different pathways. Many genes encoding important transcription factors (e.g. CBF/DREB, bHLH, MYC, and ZAT) as well as proteins (e.g. CCX, CBP, CML, and MAPK) involved in cold signal transduction were up- or down-regulated in the low temperature treatment group. Genes involved in ABA signal transduction and biosynthesis of unsaturated fatty acids were also identified. The expression profiles of these genes were analyzed during the cold treatment stage. These results provide important information for further studies on gene discovery in chrysanthemum and suggest a potential molecular mechanism for the response to low temperature in this plant species.

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.