Deformable hard tissue with high fatigue resistance in the hinge of bivalve Cristaria plicata.

The hinge of bivalve shells can sustain hundreds of thousands of repeating opening-and-closing valve motions throughout their lifetime. We studied the hierarchical design of the mineralized tissue in the hinge of the bivalve Cristaria plicata, which endows the tissue with deformability and fatigue resistance and consequently underlies the repeating motion capability. This folding fan-shaped tissue consists of radially aligned, brittle aragonite nanowires embedded in a resilient matrix and can translate external radial loads to circumferential deformation. The hard-soft complex microstructure can suppress stress concentration within the tissue. Coherent nanotwin boundaries along the longitudinal direction of the nanowires increase their resistance to bending fracture. The unusual biomineral, which exploits the inherent properties of each component through multiscale structural design, provides insights into the evolution of antifatigue structural materials.

Probiotics modulate gastrointestinal microbiota after Helicobacter pylori eradication: A multicenter randomized double-blind placebo-controlled trial.

Background: Helicobacter pylori (H. pylori) eradication has been reported to cause short-term disruption of gut microbiota. It is acknowledged that probiotics supplementation mitigates side effects induced by H. pylori eradication, yet its role on alleviating dysbiosis of microbiota is obscure. Objectives: To evaluate the impact of probiotics on gastrointestinal microbiota after eradication therapy. Methods: This was a multicenter, double-blinded, randomized trial done at seven centers in China. A total of 276 treatment-naïve H. pylori-positive patients were randomly assigned to receive 14-day bismuth-containing quadruple therapy (esomeprazole, bismuth, amoxicillin, furazolidone) combined with probiotics (Bifidobacterium Tetragenous viable Bacteria Tablets) (n=140) or placebo (n=136) for 28 days. Saliva, gastric mucosa and fecal samples were collected before and after therapy for 16S rRNA gene sequencing. Results: The incidence of gastrointestinal adverse events was lower in probiotics group compared to placebo group (23.6% vs 37.7%, p=0.016), while there was no significant difference in eradication rate. We found dramatic perturbations of gut microbiota immediately following eradication, with the predominance of Proteobacteria in replacement of commensal Firmicutes and Bacteroidetes, and gradually restored after two weeks. The reduction of gut Bacteroidetes caused by eradication drugs was neutralized with probiotics supplementation. The gastric microbiota was completely reconstituted with H. pylori depleted and other taxa flourished. Of note, patients treated with probiotics showed smaller fluctuations of gastric microbiota compared to those with placebo. We also observed changes of saliva microbiota after H. pylori eradication, illustrated by the overgrowth of Neisseria and depletion of Streptococcus. The expansion of some pathogenic genera, including Porphyromonas, Leptotrichia, in the mouth was suppressed by probiotics. Conclusion: This study not only demonstrated the beneficial effect of probiotics implementation on side events during H. pylori eradication but also provided a comprehensive profile of microbiome alterations along gastrointestinal tract that modulated by probiotics.

Polyethylene film mulching enhances the microbial carbon-use efficiency, physical and chemical protection of straw-derived carbon in an Entisol of the Loess Plateau.

The global use of agricultural polyethylene mulches has emerged as a widespread farming practice, however, its effects on the fate and dynamics of crop straw-derived C in soil microbial biomass C (MBC), aggregate-associated and chemical recalcitrance-related C fractions are rarely assessed in situ. A two-year field experiment using 13C-labeled maize stem was carried out to quantify the allocation and dynamics of straw-C in an Entisol with and without plastic mulching. The results indicated that across the treatments, from 49.2% to 56.4% of straw-13C was released as CO2-C, from 34.9% to 43.1% was sequestrated as SOC pool, and from 6.7% to 9.7% remained undecomposed at the end of the experiment. Compared to non-mulching, plastic mulching significantly decreased the straw-derived CO2-C emissions by 14.6%, partially owing to the increased incorporation of straw-C into SOC pool. Across the treatments, the straw-derived MBC ranged from 14.4 to 147.9 mg 13C kg-1; and plastic mulching increased straw-derived MBC and microbial C use efficiency (CUE) of straw residue by 41.2% and 35.2% compared with non-mulching, respectively. The allocation dynamics of straw-C in each soil aggregate followed a sustained upward trend with time, while a significantly higher straw-C was incorporated into both macro- (> 0.25 mm) and micro-aggregates (0.25-0.053 mm) with plastic mulching. Compared to the non-mulching, plastic mulching enhanced the inclusion of straw-13C in the chimerically more stable C fraction, especially at the late experimental period. We conclude that crop straw return combined with plastic mulching could improve SOC sequestration by enhancing microbial CUE, physical and chemical protection of straw-derived C in this dryland cropping system.

Alterations, Interactions, and Diagnostic Potential of Gut Bacteria and Viruses in Colorectal Cancer.

Gut microbiome alteration was closely associated with colorectal cancer (CRC). Previous studies had demonstrated the bacteria composition changes but lacked virome profiles, trans-kindom interactions, and reliable diagnostic model explorations in CRC. Hence, we performed metagenomic sequencing to investigate the gut microbiome and microbial interactions in adenoma and CRC patients. We found the decreased microbial diversity in CRC and revealed the taxonomic alterations of bacteria and viruses were highly associated with CRC at the species level. The relative abundance of oral-derived species, such as Fusobacterium nucleatum, Fusobacterium hwasookii, Porphyromonas gingivalis, and Bacteroides fragilis, increased. At the same time, butyrate-producing and anti-inflammatory microbes decreased in adenoma and CRC by non-parametric Kruskal-Wallis test. Despite that, the relative abundance of Escherichia viruses and Salmonella viruses increased, whereas some phages, including Enterobacteria phages and Uncultured crAssphage, decreased along with CRC development. Gut bacteria was negatively associated with viruses in CRC and healthy control by correlation analysis (P=0.017 and 0.002, respectively). Viruses were much more dynamic than the bacteria as the disease progressed, and the altered microbial interactions were distinctively stage-dependent. The degree centrality of microbial interactions decreased while closeness centrality increased along with the adenoma to cancer development. Uncultured crAssphage was the key bacteriophage that enriched in healthy controls and positively associated with butyrate-producing bacteria. Diagnostic tests based on bacteria by random forest confirmed in independent cohorts showed better performance than viruses for CRC. In conclusion, our study revealed the novel CRC-associated bacteria and viruses that exhibited specific differences and intensive microbial correlations, which provided a reliable diagnostic panel for CRC.

Deep dewatering process of sludge by chemical conditioning and its potential influence on wastewater treatment plants.

FeCl3, quick lime, and cationic polyacrylamide (CPAM) were used for excess sludge conditioning from wastewater treatment plant (WWTP) and the dewatering performance by different chemical conditioners was investigated. Experimental results showed that FeCl3 could make small and concentrated sludge particles. Furthermore, new mineral phase structures for building a dewatering framework were obtained by the addition of quick lime, and the coagulation capacity was enhanced by the formation of colloid hydroxyl polymer, which was induced due to the alkaline environment. In addition, the floc particle size significantly increased after the CPAM dosage. The bound water could be released with the stripping of tightly bound extracellular polymeric substance (EPS). Therefore, the dewatering performance and efficiencies were improved and subsequently the hypothetical sludge deep dewatering process was depicted in accordance with the variation of EPS. However, high-strength refractory organics in sludge filtrates caused by quick lime pyrolysis could lead to the unstable operation of the WWTP, because the relatively high concentrations of organic compounds with benzene were dominant in sludge dewatering filtrates.

Endoscopic Resection of Gastric Submucosal Masses by a Dental Floss Traction Method.

Background and Aims: ESE (endoscopic submucosal excavation) is widely used for the treatment of digestive diseases. The dental floss traction (DFT) method has been successfully used to facilitate ESE to resect mucosal lesions such as early gastric cancer. DFT has not been used in ESE to remove submucosal masses. This study aimed to examine the efficacy of DFT-assisted ESE (DFT- ESE) for the removal of submucous masses. Methods: From March 2017 to May 2017, a total of 12 patients with gastric submucosal masses at the First Affiliated Hospital of Nanchang University, Jiangxi, China, were enrolled. The tumor characteristics, en bloc resection rates, complications, and outcomes on follow-up were evaluated for all patients. Results: The 12 submucosal tumors were completely removed by DFT- ESE. Nine were gastrointestinal stromal tumors. Two were Schwannoma, located in the greater curvature of the gastric corpus. One was gastric ectopic pancreas. All the resected tumors were removed completely with intact tumor capsules. There was no more bleeding or perforation after the endoscopic closure of the perforation or the wound after the DFT-ESE, and no recurrences were identified at the time of follow-up. Conclusions: The DFT method efficiently and safely facilitated the ESE procedure during the resection of gastric submucosal tumors. This study was registered with Chinese Clinical Trial Registry under Registration number ChiCTR-OOC-15005833).

Simple Urea Immersion Enhanced Removal of Tetracycline from Water by Polystyrene Microspheres.

Antibiotics pose potential ecological risks in the water environment, necessitating their effective removal by reliable technologies. Adsorption is a conventional process to remove such chemicals from water without byproducts. However, finding cheap adsorbents with satisfactory performance is still a challenge. In this study, polystyrene microspheres (PSM) were enhanced to adsorb tetracycline by surface modification. Simple urea immersion was used to prepare urea-immersed PSM (UPSM), of which surface groups were characterized by instruments to confirm the effect of immersion. Tetracycline hydrochloride (TC) and doxycycline (DC) were used as typical adsorbates. The adsorptive isotherms were interpreted by Langmuir, Freundlich, and Tempkin models. After urea immersion, the maximum adsorption capacity of UPSM at 293 K and pH 6.8 increased about 30% and 60%, achieving 460 mg/g for TC and 430 mg/g for DC. The kinetic data were fitted by first-order and second-order kinetics and Weber⁻Morris models. The first-order rate constant for TC adsorption on UPSM was 0.41 /h, and for DC was 0.33 /h. The cyclic urea immersion enabled multilayer adsorption, which increased the adsorption capacities of TC on UPSM by two to three times. The adsorption mechanism was possibly determined by the molecular interaction including π⁻π forces, cation-π bonding, and hydrogen bonding. The simple surface modification was helpful in enhancing the removal of antibiotics from wastewater with similar structures.

Application of metabolomics profiling in the analysis of metabolites and taste quality in different subtypes of white tea.

Three subtypes of white tea, Silver Needle (SN), White Peony (WP), and Shou Mei (SM), differ in their taste, aroma, bioactivity, and commercial value. Here, a metabolomics investigation on the chemical compositions combining taste equivalent-quantification and dose-over-threshold (DoT) determination on the taste qualities were applied to comprehensively characterize the white tea subtypes for the first time. Significant differences in the contents of catechins, dimeric catechins, amino acids, phenolic acids, flavonol/flavone glycosides, and aroma precursors were observed among these 3 white teas. Metabolite content comparison and partial least-squares (PLS) analysis suggest that theanine, aspartic acid, asparagine, and AMP were positively correlated with the umami taste in white tea, and flavan-3-ols, theasinensins, procyanidin B3, and theobromine had positive correlations with higher bitterness and astringency tastes. In addition, puckering astringent (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and theogallin, bitter-tasting caffeine, and the mouth-drying/velvety-like astringent γ-aminobutyric acid (GABA) were identified as key taste compounds of white tea infusion by absolute quantification and DoT factor calculations. This work provided systematic and comprehensive knowledge on the chemical components, taste qualities, and sensory active metabolites for the subtypes of white tea.

The KSR2-rs7973260 Polymorphism is Associated with Metabolic Phenotypes, but Not Psychological Phenotypes, in Chinese Elders.

OBJECTIVE: To examine the associations between genetic variants of KSR2 (kinase suppressor of RAS)-rs7973260, RAPGEF6 (guanine nucleotide exchange factor 6)-rs3756290, LOC105377703-rs4481363, and subjective well-being (SWB) and depressive symptoms (DSs) in Chinese elders, which were recently associated in a genome-wide association study conducted in Caucasians. The pleiotropic effects of KSR2-rs7973260 on metabolic phenotypes were also explored. MATERIALS AND METHODS: We used data from 1788 older individuals aged 70-84 years from the aging arm of the Rugao Longevity and Aging Study, a population-based cohort study conducted in the Jiangsu province of China. RESULTS: No significant distributions of genotype frequencies were observed between life-satisfied and -unsatisfied groups across those with the three polymorphisms. The level of SWB components (positive affect, negative affect, and affect balance) and DSs did not differ among genotypes of the three variants. However, the presence of GA+AA of KSR2-rs7973260 was significantly higher in the metabolic syndrome (MetS), severe hypertriglyceridemia (HTG), and diabetes groups than in control groups (43.7% vs. 37.6%, 46.4% vs. 37.6%, 45.8% vs. 37.9%, respectively). The A allele of rs7973260 was associated with increased risk of MetS, severe HTG, and diabetes with an odds ratios (95% confidence intervals) of 1.289 (1.002-1.658), 1.438 (1.076-1.921), and 1.384 (1.022-1.875), which remained significant after multiple adjustments. CONCLUSION: Rs7973260, rs3756290, and rs4481363 were not associated with SWB and DSs in Chinese elders. However, the KSR2-rs7973260 A allele exhibited pleiotropic effects on some metabolic phenotypes in Chinese elders. These effects should be validated in future studies.

Preparation of three-dimensional graphene oxide-polyethylenimine porous materials as dye and gas adsorbents.

We report a facile method for the fabrication of three-dimensional (3D) porous materials via the interaction between graphene oxide (GO) sheets and polyethylenimine (PEI) with high amine density at room temperature under atmospheric pressure without stirring. The structural and physical properties of GO-PEI porous materials (GEPMs) are investigated by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and nitrogen adsorption-desorption measurement and their chemical properties are analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. GEPMs possess low density and hierarchical morphology with large specific surface area, and big pore volume. Furthermore, the as-prepared 3D porous materials show an excellent adsorption capacity for acidic dyes on the basis of the pore-rich and amine-rich graphene structure. GEPMs exhibit an extremely high adsorption capacity for amaranth (800 mg g(-1)), which are superior to other carbon materials. In addition, GEPMs also exhibit good adsorption capacity for carbon dioxide (11.2 wt % at 1.0 bar and 273 K).