Efficient expression of γ-glutamyl transpeptidase in Bacillus subtilis via CRISPR/Cas9n and its immobilization.

In this study, we successfully applied the strategy of combining tandem promoters and tandem signal peptides with overexpressing signal peptidase to efficiently express and produce γ-glutamyl peptidase (GGT) enzymes (BsGGT, BaGGT, and BlGGT) from Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus licheniformis in Bacillus subtilis ATCC6051Δ5. In order to avoid the problem of instability caused by duplicated strong promoters, we assembled tandem promoters of different homologous genes from different species. To achieve resistance marker-free enzyme in the food industry, we first removed the replication origin and corresponding resistance marker of Escherichia coli from the expression vector. The plasmid was then transformed into the B. subtilis host, and the Kan resistance gene in the expression plasmid was directly edited and silenced using the CRISPR/Cas9n-AID base editing system. As a result, a recombinant protein expression carrier without resistance markers was constructed, and the enzyme activity of the BlGGT strain during shake flask fermentation can reach 53.65 U/mL. The recombinant BlGGT was immobilized with epoxy resin and maintained 82.8% enzyme activity after repeated use for 10 times and 87.36% enzyme activity after storage at 4 °C for 2 months. The immobilized BlGGT enzyme was used for the continuous synthesis of theanine with a conversion rate of 65.38%. These results indicated that our approach was a promising solution for improving enzyme production efficiency and achieving safe production of enzyme preparations in the food industry. KEY POINTS: • Efficient expression of recombinant proteins by a combination of dual promoter and dual signal peptide. • Construction of small vectors without resistance markers in B. subtilis using CRISPR/Cas9n-AID editing system. • The process of immobilizing BlGGT with epoxy resin was optimized.

Development and application of a fast and efficient CRISPR-based genetic toolkit in Bacillus amyloliquefaciens LB1ba02.

BACKGROUND: Bacillus amyloliquefaciens is generally recognized as food safe (GRAS) microbial host and important enzyme-producing strain in the industry. B.amyloliquefaciens LB1ba02 is a production strain suitable for secreting mesophilic α-amylase in the industry. Nevertheless, due to the low transformation efficiency and restriction-modification system, the development of its CRISPR tool lags far behind other species and strains from the genus Bacillus. This work was undertaken to develop a fast and efficient gene-editing tool in B.amyloliquefaciens LB1ba02. RESULTS: In this study, we fused the nuclease-deficient mutant Cas9n (D10A) of Cas9 with activation-induced cytidine deaminase (AID) and developed a fast and efficient base editing system for the first time in B. amyloliquefaciens LB1ba02. The system was verified by inactivating the pyrF gene coding orotidine 5'-phosphate decarboxylase and the mutant could grow normally on M9 medium supplemented with 5-fluoroorotic acid (5-FOA) and uridine (U). Our base editing system has a 6nt editing window consisting of an all-in-one temperature-sensitive plasmid that facilitates multiple rounds of genome engineering in B. amyloliquefaciens LB1ba02. The total editing efficiency of this method reached 100% and it achieved simultaneous editing of three loci with an efficiency of 53.3%. In addition, based on the base editing CRISPR/Cas9n-AID system, we also developed a single plasmid CRISPR/Cas9n system suitable for rapid gene knockout and integration. The knockout efficiency for a single gene reached 93%. Finally, we generated 4 genes (aprE, nprE, wprA, and bamHIR) mutant strain, LB1ba02△4. The mutant strain secreted 1.25-fold more α-amylase into the medium than the wild-type strain. CONCLUSIONS: The CRISPR/Cas9n-AID and CRISPR/Cas9n systems developed in this work proved to be a fast and efficient genetic manipulation tool in a restriction-modification system and poorly transformable strain.

Effects of FGFR1 Gene Polymorphisms on the Risk of Breast Cancer and FGFR1 Protein Expression.

BACKGROUND/AIMS: Fibroblast growth factor receptor 1 (FGFR1) is widely considered to play an important role in mammary carcinogenesis. Some common variants in FGFR1 might be associated with its expression, and further affect breast cancer risk. The aim of this study was to investigate effects of single-nucleotide polymorphisms (SNPs) in FGFR1 on breast cancer susceptibility and FGFR1 protein expression. METHODS: SNPs rs17182023, rs17175624 and rs10958704 in FGFR1 were genotyped in 747 breast cancer cases and 716 healthy controls by SNaPshot method. The associations between SNPs and breast cancer were examined by logistic regression. Immunohistochemistry(IHC) was used to detect FGFR1 protein expression, and the association of FGFR1 polymorphisms with its protein expression was analyzed by Pearson's chi-square test. Additionally, Cox regression and Kaplan-Meier analysis was used to evaluate the association between FGFR1 protein expression and breast cancer prognosis. RESULTS: The minor allele of rs17182023 in FGFR1 was significantly associated with reduced breast cancer risk, with an odds ratio of 0.800 (95%CI = 0.684-0.935). No significant associations were detected between other SNPs and breast cancer. Moreover, rs17182023 was correlated to FGFR1 protein expression (P = 0.006), and patients with high FGFR1 protein expression tended to have poor outcomes. CONCLUSIONS: SNP rs17182023 was correlated to reduced breast cancer risk, and was associated with FGFR1 protein expression. High FGFR1 protein expression was an independent risk factor of breast cancer, and resulted in poor prognosis.

Oncogenic long noncoding RNA landscape in breast cancer.

BACKGROUND: Few long noncoding RNAs (lncRNAs) that act as oncogenic genes in breast cancer have been identified. METHODS: Oncogenic lncRNAs associated with tumourigenesis and worse survival outcomes were examined and validated in Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA), respectively. Then, the potential biological functions and expression regulation of these lncRNAs were studied via bioinformatics and genome data analysis. Moreover, progressive breast cancer subtype-specific lncRNAs were investigated via high-throughput sequencing in our cohort and TCGA validation. To elucidate the mechanisms of the regulation of these lncRNAs, genomic alterations from the TCGA, Broad, Sanger and BCCRC data, as well as epigenetic modifications from GEO data, were then applied and examined to meet this objective. Finally, cell proliferation assays, flow cytometry analyses and TUNEL assays were applied to validate the oncogenic roles of these lncRNAs in vitro. RESULTS: A cluster of oncogenic lncRNAs that was upregulated in breast cancer tissue and was associated with worse survival outcomes was identified. These oncogenic lncRNAs are involved in regulating immune system activation and the TGF-beta and Jak-STAT signalling pathways. Moreover, TINCR, LINC00511, and PPP1R26-AS1 were identified as subtype-specific lncRNAs associated with HER-2, triple-negative and luminal B subtypes of breast cancer, respectively. The up-regulation of these oncogenic lncRNAs is mainly caused by gene amplification in the genome in breast cancer and other solid tumours. Finally, the knockdown of TINCR, DSCAM-AS1 or HOTAIR inhibited breast cancer cell proliferation, increased apoptosis and inhibited cell cycle progression in vitro. CONCLUSIONS: These findings enhance the landscape of known oncogenic lncRNAs in breast cancer and provide insights into their roles. This understanding may potentially aid in the comprehensive management of breast cancer.

Asymmetric Fe-O2-Ti structures accelerate reduced-layer-FeII "electron" conversion: Facilitating photocatalytic nitrogen fixation.

As a green and sustainable method for ammonia production, solar photocatalytic nitrogen fixation (PNRR) provides a new approach to slowing down the consumption of non-renewable energy resources. Given the extremely huge energy required to activate inert nitrogen, a rational design of efficient nitrogen fixation catalytic materials is essential. This study constructs defective Ti3+-Ti3C2Ox to regulate the NH2-MIL-101(Fe) reduced layer-FeII 'electron' transition; meanwhile, the heterojunction interface electronic structure formed by coupling promotes catalytic charges' transfer/separation, while the interface-asymmetric Fe-O2-Ti structure accelerates the response with nitrogen. It is shown that the heterojunction NM-101(FeII/FeIII)-1.5 exhibits a 75.1 % FeII enrichment (FeII:FeIII), which successfully impedes the fouling relationship between the two (FeII/FeIII). Mössbauer spectroscopy analysis demonstrates that the presence of D1-high spin state FeIII and D2-low/medium spin state FeII structures in the heterojunction boosts the PNRR activity. Furthermore, it is found that the defective state Ti3+-Ti3C2Ox modulation enhances the reduced nitrogen fixation capacity of the heterojunction (CB = -0.84 eV) and decreases the interfacial charge transfer resistance, yielding 450 umol·g-1·h-1 ammonia. Furthermore, this study modulates the charge ration of the catalyst reduction layer by constructing a charge-asymmetric structure with Ti3+-deficient carriers; this method provides a potential opportunity for enhancing photocatalytic nitrogen fixation in the future.

Study on application and environmental effect of phosphogypsum-fly ash-red mud composite cemented paste backfill.

Phosphogypsum (PG) cementitious paste backfill (CPB) was prepared by using PG and fly ash (FA) as the main raw materials, red mud (RM) as the alkaline activator, Portland cement (OPC) as the binder, and silica fume (SF) as the additive, and its properties were investigated to achieve the objective of "treating harm with waste." The results showed that the addition of OPC facilitated the flowability of the slurry, while the addition of RM and SF had the opposite effect. The slurry presented ideal flowability when the water/binder ratio was 0.2 and the superplasticizer (SP) content was 0.7%. The mechanical properties and water resistance were improved significantly with increasing OPC, RM, and SF doping. The strength of the CPB material exceeded 22 MPa after curing at room temperature for 28 days, which met the mine filling requirements. Changes in the ion concentrations of the solution were first monitored during immersion. The dissolution rules of Ca2+ and SO42- at different immersion ages confirmed that RM promoted the continuous hydration of CPB, which was the key to improve water resistance. Microstructural analysis showed that the main hydration products were AFt and C-S-H, which played an important role in the strength development of the material. The leaching results demonstrated that the metal ion content satisfied the requirements of the III categories of Chinese environmental standards (GB/T 14848-2017), indicating that the technology is a reliable and environmentally friendly technology for PG, FA, and RM recovery that can simultaneously support safe mining.

Effect of microwave pretreatment on catalytic gasification of spirit-based distillers' grains to hydrogen-rich syngas.

Steam gasification of spirit-based distillers' grains (SDGs) was performed in a fixed-bed reactor under different microwave pretreatment (MWP) approaches with or without addition of red mud (RM). The effects of MWP on the gasification rate, total gas yield, H2/CO, and gasification mechanism of action were investigated. The results showed that RM could enhance the effect of MWP. The gasification rate, total gas yield and H2/CO increased by 21.29%, 8.23% and 16.08%, respectively. In addition, RM and MWP had a synergistic effect on the catalytic gasification reaction. This was because MWP disrupted the complete ordered surface structure of the SDGs, allowing a large number of inherent alkali and alkaline earth metal ions to dissolve onto the surface and combine with the catalytically active material in RM to form a uniformly dispersed bimetallic catalyst. The catalytic mechanism consisted of an active-site catalytic mechanism and a bimetallic synergistic catalytic mechanism. Therefore, the combination of MWP and SDGs steam gasification is a promising, clean, efficient hydrogen-rich synthesis gas technology.

In-situ formed Cyclodextrin-functionalized graphene oxide / poly (N-isopropylacrylamide) nanocomposite hydrogel as an recovery adsorbent for phenol and microfluidic valve.

Phenolic compounds are important industrial raw materials for various industrial applications, but phenol-containing wastewater creates significant environmental and biological hazards. To address these issues, a three-dimensional network graphene oxide-cyanoethyltriethoxysilane-ß-cyclodextrin/poly (N-isopropylacrylamide) (GO-CTES-ß-CD/PNIPAM) nanocomposite hydrogel as a phenol recovery adsorbent is prepared herein by in-situ polymerization. Double graft modification on the graphene oxide (GO) via the silane coupling agent 2-cyanoethyltriethoxysilane (CTES) and single (6-tetraethylenepentamine-6-deoxy)-ß-cyclodextrin (NH-ß-CD) compensated the loss of the active sites on both GO and N-isopropylacrylamide (NIPAM), and the hydrogel shows excellent mechanical properties as the chemical crosslinking and physical entanglement of the two components. Consequently, the composite hydrogel achieved an adsorption capacity of 131.64 mg·g-1 for the common environmental toxin 4-NP. After five repeated adsorption-desorption cycles, the hydrogel retained 74% of the initial 4-NP removal ratio. The adsorption results followed pseudo-first-order kinetics, corresponding to heterogeneous multilayer adsorption, which was regulated by a combination of surface adsorption and intra-particle diffusion mechanisms. In general, the nanocomposite hydrogel shows promising application in the field of recycling phenols from wastewater. Also, high photothermal conversion and temperature-sensitive properties are also demonstrated, which makes the hydrogel possessing great potential to be applied in smart microvalves.

Oxygen and Titanium Vacancies in a BiOBr/MXene-Ti3C2 Composite for Boosting Photocatalytic N2 Fixation.

Solar energy can be used as "green" energy by photocatalysis for the nitrogen fixation under the atmospheric conditions compared with the traditional energy-intensive industrial production of ammonia. However, the complex kinetics and high reaction barriers greatly hinder the development of the photocatalytic N2 reduction reaction. Herein, a BiOBr/MXene-Ti3C2 composite catalyst is prepared by the simple electrostatic adsorption and self-assembly method. The as-prepared 10 wt % BiOBr/Ti3C2 exhibits the best performance for N2 fixation to NH3 by photocatalysis. The evolution rate of NH3 is up to 234.6 µmol·g-1·h-1, which is approximately 48.8 times and 52.4 times higher than those of pure BiOBr and Ti3C2, respectively. It is found that the designed double vacancies of oxygen and titanium for BiOBr/Ti3C2 composites, with the availability of localized electrons, have the ability to adsorb and activate N2, which can be efficiently reduced to NH3 by the interfacial electrons transferred from the excited BiOBr/Ti3C2 composite. In addition, the results of in situ Fourier transform infrared show the generation of NxHy species by the continuous protonation processes. Moreover, titanium vacancy (VTi) induces a strong absorption energy for nitrogen atoms on the surface of BiOBr/Ti3C2 according to the density functional theory calculations. In particular, the P-electron feedback caused by VTi could effectively promote the weakening of the N≡N triple bond and elongate the N2 bond length by ∼31.6%. This work might provide new insights into the synergistic effect of double defects and inspiration for the rational design of catalysts by defect engineering in the field of catalytic synthesis of ammonia.

Construction of Bi2O2CO3/Ti3C2 heterojunctions for enhancing the visible-light photocatalytic activity of tetracycline degradation.

Bi2O2CO3 (BOC) was successfully loaded on a highly conductive Ti3C2 surface by the hydrothermal method, forming a unique BOC/Ti3C2 heterostructure. The use of advanced characterization methods reveals the composition, morphology and photoelectric properties of the material. The results show that the interface formed by close contact between BOC and Ti3C2 provides an effective channel for charge transfer between the two. Importantly, the photocatalytic degradation efficiency of BOC/Ti3C2 for tetracycline (TC) is ~80%, which is significantly higher than the degradation efficiency of pure BOC and pure Ti3C2 for TC. In addition, BOC/Ti3C2 still has high catalytic activity in the degradation of complex mixed antibiotics. This is because BOC and Ti3C2 have large specific surface areas, high light absorption capacity and efficient carrier separation after recombination. At the same time, the detected superoxide radicals (O2-) and holes (h+) are the main active substances. The degradation pathway and catalytic mechanism of the photocatalytic degradation of TC by BOC/Ti3C2 are further explained. This research designed and developed a BOC/Ti3C2 composite material for the photocatalytic degradation of tetracycline and mixed antibiotic wastewater, providing experimental methods and ideas for actual wastewater treatment.

Fabrication of novel CuFe2O4/MXene hierarchical heterostructures for enhanced photocatalytic degradation of sulfonamides under visible light.

The overuse of sulfonamides, causing serious pollution of water bodies, has drawn great attention from society. To address these problems, a novel CuFe2O4/MXene (CFO/Ti3C2) heterojunction photocatalyst was used to photodegrade the antibiotic sulfamethazine (SMZ, a typical pollutant) under visible light, and the synergy and coupling function of the two components in the heterojunction system were analyzed. With the aid of time-resolved photoluminescence (TRPL) and transient surface photovoltage (TPV) spectra, the carrier lifetimes and kinetic behaviors were studied, revealing that the lifetime of photoinduced carriers was prolonged by loading Ti3C2, inhibiting the reorganization of photogenerated electron holes. More importantly, the organic intermediates and mineralization degree were identified by high-performance liquid chromatography (HPLC)-mass spectrometry (MS) and total organic carbon (TOC) techniques. The results show that the breaking of SN bonds, the oxidation of aniline and deamination were dominated by the attack of •OH. This work shows a new model for the degradation mechanism of SMZ over CFO/MXene heterostructures.

The effect of a diet based on rice straw co-fermented with probiotics and enzymes versus a fresh corn Stover-based diet on the rumen bacterial community and metabolites of beef cattle.

Improvement of the food value of rice straw is urgently required in rice crop growing areas to mitigate pollution caused by rice straw burning and enhance the supply of high-quality forages for ruminants. The aims of the present study were to compare the effects of fresh corn Stover and rice straw co-fermented with probiotics and enzymes on rumen fermentation and establish the feasibility of increasing the rice straw content in ruminant diets and, by extension, reducing air pollution caused by burning rice straw. Twenty Simmental hybrid beef cattle were randomly allotted to two groups with ten cattle per group. They were fed diets based either on rice straw co-fermented with probiotics and enzymes or fresh corn Stover for 90 days. Rumen fluid was sampled with an esophageal tube vacuum pump device from each animal on the mornings of days 30, 60, and 90. Bacterial diversity was evaluated by sequencing the V4-V5 region of the 16S rRNA gene. Metabolomes were analyzed by gas chromatography/time-of-flight mass spectrometry (GC-TOF/MS). Compared to cattle fed fresh corn Stover, those fed rice straw co-fermented with probiotics and enzymes had higher (P < 0.05) levels of acetic acid and propionate in rumen liquid at d 60 and d 90 respectively, higher (P < 0.05) abundances of the phyla Bacteroidetes and Fibrobacteres and the genera Ruminococcus, Saccharofermentans, Pseudobutyrivibrio, Treponema, Lachnoclostridium, and Ruminobacter, and higher (P < 0.05) concentrations of metabolites involved in metabolisms of amino acid, carbohydrate, and cofactors and vitamins. Relative to fresh corn Stover, rice straw co-fermented with probiotics and enzymes resulted in higher VFA concentrations, numbers of complex carbohydrate-decomposing and H2-utilizing bacteria, and feed energy conversion efficiency in the rumen.

Removal of Fluorine from Wet-Process Phosphoric Acid Using a Solvent Extraction Technique with Tributyl Phosphate and Silicon Oil.

The deep removal of fluorine from wet-process phosphoric acid is currently a very serious issue. In this paper, an efficient liquid-liquid separation method based on a bubble membrane was developed to solve this problem. Tributyl phosphate (TBP) and silicon oil (SIO) were used as the organic phase. The effects of the component proportion in the organic phase (TBP/SIO v/v), organic to aqueous phase ratio (O/A), pH, temperature, and reaction time on the extraction ratio were investigated. The extraction ratio of fluorine was 98.4% when using only one stage with the following conditions: 90 °C, pH -0.46, volume ratio (TBP/SIO v/v) of 7:3, phase ratio (O/A) of 1:5, stirring speed of 200 rpm, and reaction time of 50 min. Fourier-transform infrared spectroscopy and inverted fluorescence microscopy were used to investigate the reaction mechanism and reaction kinetics. In addition, the scrubbing and stripping process was investigated. When a 2 mol/L sodium hydroxide solution ([NaOH]) was used as the stripping agent with a phase ratio (O/A) of 1:10, a stirring speed of 200 rpm, and a reaction time of 30 min, a maximum stripping ratio of 90.1% was obtained.

Fabrication of Ag/AgBr/Ag3VO4 composites with high visible light photocatalytic performance.

Herein, Ag/AgBr/Ag3VO4 composites were synthesized by a simple continuous precipitation method. The obtained composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy (PL). Photocatalytic performance of the composites was assessed by the degradation of methyl orange (MO) and tetracycline hydrochloride (TC) under visible light, and the effects of different nominal mass ratios of AgBr and Ag3VO4 on the photocatalytic activity were investigated. The results showed that after 20 min of visible light irradiation (λ > 420 nm), the removal rate of MO in the presence of a 5 : 1 sample reached 98.6%. The EIS and photocurrent results demonstrated that the enhancement of the visible light photocatalytic activity was attributed to the efficient electron-hole pair separation. In addition, the scavenging reactions conducted via the addition of different scavengers confirmed that h+ and ·O2- were the main active species in the reaction. The present study offers potential for the degradation of contaminants.

Functionalized Large-Pore Mesoporous Silica Microparticles for Gefitinib and Doxorubicin Codelivery.

Large-pore coralline mesoporous silica microparticles (CMS) were synthesized using the triblock polymer PEG-b-PEO-b-PEG and a hydrothermal method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the coralline morphology of the fabricated materials. The Brunauer⁻Emmett⁻Teller (BET) method and the Barrett⁻Joyner⁻Halenda (BJH) model confirmed the existence of large pores (20 nm) and of a tremendous specific surface area (663.865 m²·g-1) and pore volume (0.365 cm³·g-1). A novel pH-sensitive multiamine-chain carboxyl-functionalized coralline mesoporous silica material (CMS⁻(NH)3⁻COOH) was obtained via a facile "grafting-to" approach. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) validated the effective interfacial functionalization of CMS with carboxyl and multiamine chains. The encapsulation and release behavior of the dual drug (gefitinib (GB) and doxorubicin (DOX)) was also investigated. It was found that CMS⁻(NH)3⁻COOH allows rapid encapsulation with a high loading capacity of 47.36% for GB and 26.74% for DOX. Furthermore, the release profiles reveal that CMS⁻(NH)3⁻COOH can preferably control the release of DOX and GB. The accumulative release rates of DOX and GB were 32.03% and 13.66%, respectively, at a low pH (pH 5.0), while they reduced to 8.45% and 4.83% at pH 7.4. Moreover, all of the modified silica nanoparticles exhibited a high biocompatibility with a low cytotoxicity. In particular, the cytotoxicity of both of these two drugs was remarkably reduced after being encapsulated. CMS⁻(NH)3⁻COOH@GB@DOX showed tremendously synergistic effects of the dual drug in the antiproliferation and apoptosis of A549 human cancer cells in vitro.

Steam co-gasification of different ratios of spirit-based distillers' grains and anthracite coal to produce hydrogen-rich gas.

In this study, the gas release rate and gas composition in the steam gasification of blends of anthracite coal and spirit-based distillers' grains (SDG) with mass ratios of 3:1, 1:1, and 1:3 were studied. The changes in the gasification reaction activity for different gasification temperatures and sample ratios were investigated, and the synergy between SDG and coal in terms of co-gasification was analysed. The results indicated that the instantaneous release rate of hydrogen was higher than that of other gases for all sample ratios. Upon the addition of SDG, the H2 content increased while CO and CO2 contents decreased. The gasification reactivity increased with decreased temperature and ratio of SDG. Furthermore, potassium and calcium in SDG ash played a synergistic catalytic role in the gasification reaction.

One-Step Synthesis of a Nanosized Cubic Li2TiO3-Coated Br, C, and N Co-Doped Li4Ti5O12 Anode Material for Stable High-Rate Lithium-Ion Batteries.

Nanosized Li4Ti5O12 with both a Li2TiO3 coating and C-N-Br co-doping (CLLTO) was successfully synthesized via a facile reverse microemulsion method in one step using hexadecyl trimethyl ammonium bromide as a surface control agent and as a carbon, nitrogen, and bromine source. A uniform Li2TiO3 layer was formed on the surface and strongly adhered to the host material Li4Ti5O12 (LTO), which played an important role in improving the cyclic stability of CLLTO. The thin and stable Li2TiO3 layer has the same cubic structure as LTO, which provides many three-dimensional channels for ion transport. C, N, and Br co-doping in CLLTO promoted the transition of Ti4+ to Ti3+ in Li4Ti5O12, which could improve the capacity and facilitate the Li+ ion and electron transfer at the interface. The conductive behavior induced by co-doping was estimated by UV-vis diffuse reflectance spectra and further supported by theoretical calculations. The electrical conductivity of both p-type and n-type LTO can be well improved by co-doping C, N, and Br. This improvement may be due to the band gap reduction and the increased n-type electronic modification of the entire LTO. Owing to the synergistic effect of coating, co-doping, and nanosizing at one time, the CLLTO exhibits a high discharge capacity of 177.3-153.9 mA h g-1 at the working rate of 0.1C-20C, with a capacity retention of 86%. The stable cycling of CLLTO is also obtained after 500 cycles at 20C, with a capacity retention of 95.5% (approximately 8 times higher than that of pure LTO) and almost 100% Coulombic efficiency. With high capacity, excellent rate performance, and good cycling stability, CLLTO can be applied in high-power lithium-ion batteries.

Effects of Pr and Yb Dual Doping on the Thermoelectric Properties of CaMnO3.

There has been research on CaMnO3 with natural abundance, low toxicity, and low cost as promising candidates for n-type thermoelectric (TE) materials. In this paper, Ca1-2xPrxYbxMnO3 with different Pr and Yb contents (x = 0, 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by means of coprecipitation. With X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), researchers characterized the phase structure and morphology of all the samples. The oxidation states of manganese were determined by X-ray photoemission spectroscopy (XPS). The role of Ca-site dual doping in the TE properties was also investigated. Increasing the Pr and Yb contents leads to decreases in the electrical resistivity and Seebeck coefficient, leading to a power factor of 3.48 × 10-4 W·m-1·K-2 for x = 0.04 at 773 K, which is its maximum. Furthermore, the thermal conductivity (κ) decreases with increasing x, and κ = 1.26 W m-1·K-1 is obtained for x = 0.04 at 973 K. Ca0.92Pr0.04Yb0.04MnO3 exhibit a ZT (thermoelectric figure of merit) value of 0.24 at 973 K, approximately 3 times more than that of the pristine CaMnO3. Thus, the reported method is a new strategy to enhance the TE performance of CaMnO3.

Silicate silver/flower-like magnalium hydroxide composites for enhanced visible light photodegradation activities.

Flower-like magnalium layered composites (MgAl-LDH) were first fabricated by a hydrothermal method, and a series of AgSiO x /MgAl-LDH composites with different mole ratios was successfully prepared by loading AgSiO x on the MgAl-LDH surface. The photocatalytic activities of the composites for the degradation of methylene blue (MB) were investigated under visible light irradiation (xenon lamp). The prepared AgSiO x /MgAl-LDH composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy, thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS). The results revealed that AgSiO x /MgAl-LDH (5 : 1) displayed a photocatalytic degradation efficiency of 99.7% in 30 min for MB. The photocatalytic degradation rate was higher than that of pure AgSiO x .

Mindfulness training for psychological stress in family caregivers of persons with dementia: a systematic review and meta-analysis of randomized controlled trials.

Caring for a relative with dementia is extremely challenging; conventional interventions may not be highly effective or easily available on some occasions. This study aimed to explore the efficacy of mindfulness training in improving stress-related outcomes in family caregivers of people with dementia using a meta-analytic review. We searched randomized controlled trials (RCT) through April 2017 from five electronic databases, and assessed the risk of bias using the Cochrane Collaboration tool. Seven RCTs were included in our review. Mindfulness interventions showed significant effects of improvement in depression (standardized mean difference: -0.58, [95% CI: -0.79 to -0.37]), perceived stress (-0.33, [-0.57 to -0.10]), and mental health-related quality of life (0.38 [0.14 to 0.63]) at 8 weeks post-treatment. Pooled evidence did not show a significant advantage of mindfulness training compared with control conditions in the alleviation of caregiver burden or anxiety. Future large-scale and rigorously designed trials are needed to confirm our findings. Clinicians may consider the mindfulness program as a promising alternative to conventional interventions.