Untargeted Metabolome Analyses Revealed Potential Metabolic Mechanisms of Leymus chinensis in Response to Simulated Animal Feeding.

Leymus chinensis (Trin.) Tzvel., also known as the "Alkali Grass", is a major forage grass in the eastern and northeastern steppe vegetation in the Songnen Prairie. It is of great practical significance for grassland management to understand the influence of animal saliva on L. chinensis during animal feeding. In this study, we used clipping and daubing animal saliva to simulate responses to grazing by L. chinensis, and analyzed the physiological and metabolomic changes in response to simulated animal feeding. Results showed that the effects of animal saliva on physiological and metabolic processes of the treated plants produced a recovery phenomenon. Moreover, the effects of animal saliva produced a large number of differential metabolites related to several known metabolic pathways, among which the flavonoid biosynthesis pathway has undergone significant and persistent changes. We posit that the potential metabolic mechanisms of L. chinensis in response to simulated animal feeding are closely related to flavonoid biosynthesis.

Electronically Coupled 2D Polymer/MoS2 Heterostructures.

Emergent quantum phenomena in electronically coupled two-dimensional heterostructures are central to next-generation optical, electronic, and quantum information applications. Tailoring electronic band gaps in coupled heterostructures would permit control of such phenomena and is the subject of significant research interest. Two-dimensional polymers (2DPs) offer a compelling route to tailored band structures through the selection of molecular constituents. However, despite the promise of synthetic flexibility and electronic design, fabrication of 2DPs that form electronically coupled 2D heterostructures remains an outstanding challenge. Here, we report the rational design and optimized synthesis of electronically coupled semiconducting 2DP/2D transition metal dichalcogenide van der Waals heterostructures, demonstrate direct exfoliation of the highly crystalline and oriented 2DP films down to a few nanometers, and present the first thickness-dependent study of 2DP/MoS2 heterostructures. Control over the 2DP layers reveals enhancement of the 2DP photoluminescence by two orders of magnitude in ultrathin sheets and an unexpected thickness-dependent modulation of the ultrafast excited state dynamics in the 2DP/MoS2 heterostructure. These results provide fundamental insight into the electronic structure of 2DPs and present a route to tune emergent quantum phenomena in 2DP hybrid van der Waals heterostructures.

A Mussel-Inspired Persistent ROS-Scavenging, Electroactive, and Osteoinductive Scaffold Based on Electrochemical-Driven In Situ Nanoassembly.

Conductive polymers are promising for bone regeneration because they can regulate cell behavior through electrical stimulation; moreover, they are antioxidative agents that can be used to protect cells and tissues from damage originating from reactive oxygen species (ROS). However, conductive polymers lack affinity to cells and osteoinductivity, which limits their application in tissue engineering. Herein, an electroactive, cell affinitive, persistent ROS-scavenging, and osteoinductive porous Ti scaffold is prepared by the on-surface in situ assembly of a polypyrrole-polydopamine-hydroxyapatite (PPy-PDA-HA) film through a layer-by-layer pulse electrodeposition (LBL-PED) method. During LBL-PED, the PPy-PDA nanoparticles (NPs) and HA NPs are in situ synthesized and uniformly coated on a porous scaffold from inside to outside. PDA is entangled with and doped into PPy to enhance the ROS scavenging rate of the scaffold and realize repeatable, efficient ROS scavenging over a long period of time. HA and electrical stimulation synergistically promote osteogenic cell differentiation on PPy-PDA-HA films. Ultimately, the PPy-PDA-HA porous scaffold provides excellent bone regeneration through the synergistic effects of electroactivity, cell affinity, and antioxidative activity of the PPy-PDA NPs and the osteoinductivity of HA NPs. This study provides a new strategy for functionalizing porous scaffolds that show great promise as implants for tissue regeneration.

Epithelial-specific deletion of FAM20A leads to short root defects.

Short Root Defects defined by a reduced ratio of root to crown, may culminate in root resorption and subsequent tooth loss, in spite of the absence of apparent symptoms. Such defects present considerable impediments to orthodontic treatment and restoration. Recent identification of Fam20a, an emergent pseudokinase, has been associated with enamel development and tooth eruption, yet its definitive role in root formation and eruption remains ambiguous. In this research, we initially ascertained that the targeted knockout of Fam20a within the epithelium led to truncated tooth roots, irregular breaks in the epithelial root sheath initiation of the WNT signaling pathway, and decreased expression of the cell polarity-related transcription factor Cdc42 in murine models. This was concomitant with the participation of the associated epithelial root sheath developmental pathways BMP2, Gli1, and Nfic. Furthermore, we observed that Fam20a predominantly affects the intraosseous eruption phase of tooth emergence. During this phase, the osteoclast peak around the mandibular first molar in cKO mice is delayed, leading to a slower formation of the eruption pathway, ultimately resulting in delayed tooth eruption in mice. The findings of this study enrich the extant knowledge regarding the role of Fam20a, suggesting its potential regulatory function in tooth root development through the WNT/ß-catenin/Cdc42 pathway.

Role of ferroptosis-related genes in periodontitis based on integrated bioinformatics analysis.

BACKGROUND: Cell survival or death is one of the key scientific issues of inflammatory response. To regulate cell death during the occurrence and development of periodontitis, various forms of programmed cell death, such as pyroptosis, ferroptosis, necroptosis, and apoptosis, have been proposed. It has been found that ferroptosis characterized by iron-dependent lipid peroxidation is involved in cancer, degenerative brain diseases and inflammatory diseases. Furthermore, NCOA4 is considered one of ferroptosis-related genes (FRGs) contributing to butyrate-induced cell death in the periodontitis. This research aims to analyze the expression of FRGs in periodontitis tissues and to explore the relationship between ferroptosis and periodontitis. METHOD: Genes associated with periodontitis were retrieved from two Gene Expression Omnibus datasets. Then, we normalized microarray data and removed the batch effect using the R software. We used R to convert the mRNA expression data and collected the expression of FRGs. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), transcription factor (TF) and protein-protein interaction (PPI) network analyses were used. In addition, we constructed a receiver operating characteristic curve and obtained relative mRNA expression verified by quantitative reverse-transcription polymerase chain reaction (PCR). RESULTS: Eight and 10 FRGs related to periodontitis were upregulated and downregulated, respectively. GO analysis showed that FRGs were enriched in the regulation of glutathione biosynthetic, glutamate homeostasis, and endoplasmic reticulum-nucleus signaling pathway. The top TFs included CEBPB, JUND, ATF2. Based on the PPI network analysis, FRGs were mainly linked to the negative regulation of IRE1-mediated unfolded protein response, regulation of type IIa hypersensitivity, and regulation of apoptotic cell clearance. The expression levels of NCOA4, SLC1A5 and HSPB1 using PCR were significantly different between normal gingival samples and periodontitis samples. Furthermore, the diagnostic value of FRGs for periodontitis were "Good". CONCLUSIONS: We found significant associations between FRGs and periodontitis. The present study not only provides a new possible pathomechanism for the occurrence of periodontitis but also offers a new direction for the diagnosis and treatment of periodontitis.

Genomic epidemiology of coxsackievirus A16 in mainland of China, 2000-18.

Hand, foot, and mouth disease (HFMD), which is a frequently reported and concerning disease worldwide, is a severe burden on societies globally, especially in the countries of East and Southeast Asia. Coxsackievirus A16 (CV-A16) is one of the most important causes of HFMD and a severe threat to human health, especially in children under 5 years of age. To investigate the epidemiological characteristics, spread dynamics, recombinant forms (RFs), and other features of CV-A16, we leveraged the continuous surveillance data of CV-A16-related HFMD cases collected over an 18-year period. With the advent of the EV-A71 vaccine since 2016, which targeted the EV-A71-related HFMD cases, EV-A71-related HFMD cases decreased dramatically, whereas the CV-A16-related HFMD cases showed an upward trend from 2017 to October 2019. The CV-A16 strains observed in this study were genetically related and widely distributed in the mainland of China. Our results show that three clusters (B1a-B1c) existed in the mainland of China and that the cluster of B1b dominates the diffusion of CV-A16 in China. We found that eastern China played a decisive role in seeding the diffusion of CV-A16 in China, with a more complex and variant transmission trend. Although EV-A71 vaccine was launched in China in 2016, it did not affect the genetic diversity of CV-A16, and its genetic diversity did not decline, which confirmed the epidemiological surveillance trend of CV-A16. Two discontinuous clusters (2000-13 and 2014-18) were observed in the full-length genome and arranged along the time gradient, which revealed the reason why the relative genetic diversity of CV-A16 increased and experienced more complex fluctuation model after 2014. In addition, the switch from RFs B (RF-B) and RF-C co-circulation to RF-D contributes to the prevalence of B1b cluster in China after 2008. The correlation between genotype and RFs partially explained the current prevalence of B1b. This study provides unprecedented full-length genomic sequences of CV-A16 in China, with a wider geographic distribution and a long-term time scale. The study presents valuable information about CV-A16, aimed at developing effective control strategies, as well as a call for a more robust surveillance system, especially in the Asia-Pacific region.

Plant-inspired adhesive and tough hydrogel based on Ag-Lignin nanoparticles-triggered dynamic redox catechol chemistry.

Adhesive hydrogels have gained popularity in biomedical applications, however, traditional adhesive hydrogels often exhibit short-term adhesiveness, poor mechanical properties and lack of antibacterial ability. Here, a plant-inspired adhesive hydrogel has been developed based on Ag-Lignin nanoparticles (NPs)triggered dynamic redox catechol chemistry. Ag-Lignin NPs construct the dynamic catechol redox system, which creates long-lasting reductive-oxidative environment inner hydrogel networks. This redox system, generating catechol groups continuously, endows the hydrogel with long-term and repeatable adhesiveness. Furthermore, Ag-Lignin NPs generate free radicals and trigger self-gelation of the hydrogel under ambient environment. This hydrogel presents high toughness for the existence of covalent and non-covalent interaction in the hydrogel networks. The hydrogel also possesses good cell affinity and high antibacterial activity due to the catechol groups and bactericidal ability of Ag-Lignin NPs. This study proposes a strategy to design tough and adhesive hydrogels based on dynamic plant catechol chemistry.

[Cloning and expression of a novel metallothionein gene LbMT2 from Limonium bicolor].

The full length cDNA of a novel metallothionein (LbMT2) gene was cloned from a cDNA library of Limonium bicolor. The LbMT2 gene cloned is 518 bp in length, which includes a 64 bp of 5' untranslated region (UTR) and a 205 bp of 3' untranslated region. This gene has an open reading frame (ORF) of 249 bp in length, encoding a protein of 82 amino acid residues with the molecular mass of 8.1 kDa and theoretical pI of 4.71. The expression of LbMT2 gene in L. bicolor in response to CuSO4, CdCl2, NaCl, cold, and PEG was further investigated using real time quantitative PCR. In both leaf and root of L. bicolor, the expression of LbMT2 was induced by CuSO4, CdCl2, NaCl, and cold, but inhibited by PEG stress. LbMT2 gene was inserted into a prokaryotic expression vector (pGEX-4T-2) to produce the recombinant expression vector pGEX-LbMT2. The expression of LbMT2 in E. coli BL21 was induced with IPTG, which produced a protein band with expected size of 35 kDa on SDS-PAGE.

Simultaneous voltammetry detection of dopamine and uric acid in human serum and urine with a poly(procaterol hydrochloride) modified glassy carbon electrode.

In the present study, procaterol hydrochloride (ProH) was successfully electropolymerized onto a glass carbon electrode (GCE) with simply cyclic voltammetry scans to construct a poly(procaterol hydrochloride) (p-ProH) membrane modified electrode. Compared with the bare GCE, much higher oxidation peak current responses and better peak potentials separation could be obtained for the simultaneous oxidation of dopamine (DA) and uric acid (UA), owning to the excellent electrocatalytic ability of the p-ProH membrane. And it's based on that a square wave voltammetry (SWV) method was developed to selective and simultaneous measurement of DA and UA. Under the optimum conditions, the linear dependence of oxidation peak current on analyte concentrations were found to be 1.0-100 µmol/L and 2-100 µmol/L, giving detection limits of 0.3 µmol/L and 0.5 µmol/L for DA and UA, separately. The as prepared modified electrode shows simplicity in construction with the merits of good reproducibility, high stability, passable selectivity and nice sensitivity. Finally, the proposed p-ProH membrane modified electrode was successfully devoted to the detection of DA and UA in biological fluids such as human serum and urine with acceptable results.

Risk factors of periodontal disease in maintenance hemodialysis patients.

To explore the characteristics and relevant risk factors of periodontal disease (PD) among hemodialysis patients.Uremic patients on maintenance hemodialysis from November 2015 to March 2016 were retrospectively reviewed. Patients were divided into a PD group and a non-PD group. Demographic and laboratory data were collected and analyzed.In all, 136 uremic patients (79 males and 57 females, aged 50.8 ±â€Š15.3 years) on maintenance hemodialysis were included in this study. The incidence of PD increased with age. Hemodialysis patients most likely developed PD if they were male, smokers, or diabetic (P = .009, <.001, and <.001, respectively). Patients brushing their teeth twice daily had significantly less chance of developing PD as compared with those only brushing once daily (P < .001). Hemodialysis patients in the PD group had significantly higher levels of total cholesterol, high-sensitivity C-reactive protein, fasting blood glucose, and peripheral white blood cell counts, compared with the non-PD group (all P < .001). Logistic regression analysis revealed that diabetes, total cholesterol, high-sensitivity C-reactive protein, and peripheral white blood cell count were independent risk factors for developing PD, whereas teeth brushing twice daily and serum calcium were favorable factors for maintenance hemodialysis patients against PD.Identification of risk factors provides a theoretical basis for prevention and improvement of PD among maintenance hemodialysis patients.

Electrochemical investigation and determination of procaterol hydrochloride on poly(glutamic acid)/carboxyl functionalized multiwalled carbon nanotubes/polyvinyl alcohol modified glassy carbon electrode.

Poly(glutamic acid) (P-GLU)/carboxyl functionalized multiwalled carbon nanotubes (MWCNTs-COOH)/polyvinyl alcohol (PVA) modified glassy carbon electrode (GCE) has been successfully prepared and the electrochemical behavior of procaterol hydrochloride (ProH) was studied. The results show that the as-prepared modified electrode exhibits a good electrocatalytic property towards the oxidation of ProH in 0.2M phosphate buffer solution (PBS) (pH 6.0) due to the enhanced oxidation peak current at ~+0.59V. Under optimal reaction conditions, the oxidation peak current of ProH is proportional to its concentration in the linear dynamic ranges of 0.060 - 8.0µM (R = 0.9974), with a detection limit of 8.0 × 10-9M. Finally, this method was efficiently used for the determination of ProH in tablets and human urine with recoveries of 88.5~98.7% and 89.2 ~ 108.0%, respectively.

Prevalence of enteroviruses in healthy populations and excretion of pathogens in patients with hand, foot, and mouth disease in a highly endemic area of southwest China.

Etiological carriers and the excretion of the pathogens causing hand, foot, and mouth disease (HFMD) in healthy persons, patients, and asymptomatic persons infected with HFMD as ongoing infection sources may play an important role in perpetuating and spreading epidemics of HFMD. The aims of this study were to determine the carrier status of EV-A71 and CV-A16 in healthy populations, as well as the duration of EV-A71 and CV-A16 shedding in the stools of HFMD patients in an epidemic area of southwest China. A cross-sectional study and a follow-up study were conducted in three HFMD endemic counties of Yunnan Province. Six hundred sixty-seven healthy subjects were recruited to participate in the cross-sectional study, and two stool specimens were collected from each subject. Among the healthy subjects, 90 (13.5%) tested positive for viral isolation, but neither EV-A71 nor CV-A16 was detected in healthy individuals. Of the 150 patients with probable HFMD, 55.3% (83/150) tested positive for viral isolation with presented serotypes such as EV-A71 (51.81%, 43/83), CV-A16 (32.53%, 27/83), other EVs (13.25%, 11/83), and mixed EV-A71 and CV-A16 (2.41%, 2/83). The longest duration of EV-A71 and CV-A16 shedding in stool specimens from patients with HFMD was >46 days after onset. The positive rate of EV-A71 in the stool specimens of confirmed patients dropped to 50% by the end of the third week, and the same occurred with CV-A16 by the end of approximately the seventh week after onset. Although carriers of major causative agents of HFMD in healthy populations are fewer in number, the prolonged shedding of pathogens in patients with HFMD may serve as an important factor in perpetuating and spreading HFMD epidemics.

Role of quality control circle in sustained improvement of hand hygiene compliance: an observational study in a stomatology hospital in Shandong, China.

BACKGROUND: Hand hygiene is an important element of the WHO multimodal strategy for healthcare-associated infection control, whereas compliance of hand hygiene among healthcare workers (HCWs) remains a challenge to sustain. In order to increase the hand hygiene compliance of HCWs, a quality control circle (QCC) program was carried out in our hospital, and the plan-do-check-act (PDCA) method was applied for 12 months. FINDINGS: Hand hygiene compliance rates improved over time, with significant improvement between preintervention (60.1%) and postintervention (97.2%) periods (P < 0.001). Nurses (88.3%) exhibited higher compliance than dentists (87.3%), and female (88.4%) HCWs were more likely to perform hand hygiene than males (85.6%), both P < 0.001. Overall hand hygiene compliance and observance of the five indications exhibited significant linear increases over time (P < 0.005). CONCLUSION: This study highlights the success of a multifaceted intervention, conducted by QCC program and PDCA method, which led to a significant improvement of hand hygiene compliance. Though training is the most basic intervention element, surveillance, evaluation and feedback should be explored as additional interventions to ensure that hand hygiene compliance is achieved and sustained at high levels.

Template-assisted low temperature synthesis of functionalized graphene for ultrahigh volumetric performance supercapacitors.

We demonstrated the fabrication of functionalized graphene nanosheets via low temperature (300 °C) treatment of graphite oxide with a slow heating rate using Mg(OH)2 nanosheets as template. Because of its dented sheet with high surface area, a certain amount of oxygen-containing groups, and low pore volume, the as-obtained graphene delivers both ultrahigh specific gravimetric and volumetric capacitances of 456 F g(-1) and 470 F cm(-3), almost 3.7 times and 3.3 times higher than hydrazine reduced graphene, respectively. Especially, the obtained volumetric capacitance is the highest value so far reported for carbon materials in aqueous electrolytes. More importantly, the assembled supercapacitor exhibits an ultrahigh volumetric energy density of 27.2 Wh L(-1), which is among the highest values for carbon materials in aqueous electrolytes, as well as excellent cycling stability with 134% of its initial capacitance after 10,000 cycles. Therefore, the present work holds a great promise for future design and large-scale production of high performance graphene electrodes for portable energy storage devices.

Fabrication and evaluation of a sustained-release chitosan-based scaffold embedded with PLGA microspheres.

Nutrient depletion within three-dimensional (3D) scaffolds is one of the major hurdles in the use of this technology to grow cells for applications in tissue engineering. In order to help in addressing it, we herein propose to use the controlled release of encapsulated nutrients within polymer microspheres into chitosan-based 3D scaffolds, wherein the microspheres are embedded. This method has allowed maintaining a stable concentration of nutrients within the scaffolds over the long term. The polymer microspheres were prepared using multiple emulsions (w/o/w), in which bovine serum albumin (BSA) and poly (lactic-co-glycolic) acid (PLGA) were regarded as the protein pattern and the exoperidium material, respectively. These were then mixed with a chitosan solution in order to form the scaffolds by cryo-desiccation. The release of BSA, entrapped within the embedded microspheres, was monitored with time using a BCA kit. The morphology and structure of the PLGA microspheres containing BSA before and after embedding within the scaffold were observed under a scanning electron microscope (SEM). These had a round shape with diameters in the range of 27-55 µm, whereas the chitosan-based scaffolds had a uniform porous structure with the microspheres uniformly dispersed within their 3D structure and without any morphological change. In addition, the porosity, water absorption and degradation rate at 37 °C in an aqueous environment of 1% chitosan-based scaffolds were (92.99±2.51) %, (89.66±0.66) % and (73.77±3.21) %, respectively. The studies of BSA release from the embedded microspheres have shown a sustained and cumulative tendency with little initial burst, with (20.24±0.83) % of the initial amount released after 168 h (an average rate of 0.12%/h). The protein concentration within the chitosan-based scaffolds after 168 h was found to be (11.44±1.81)×10(-2) mg/mL. This novel chitosan-based scaffold embedded with PLGA microspheres has proven to be a promising technique for the development of new and improved tissue engineering scaffolds.

[Genetic characteristics of EV71 in Yunnan Province from 2009 to 2010].

In order to learn about the genetic characteristic of human enterovirus type71 (HEV71) isolated from cases of Hand, Foot and Mouth Disease (HFMD) in Yunnan Province from 2009 to 2010. 50 isolates form HFMD cases were performed entire VP1 coding region amplification by reverse transcription-polymerase chain reaction and sequencing the nucleotide sequences; then the phylogenetic tree was constructed. The complete nucleotide sequences of region VP1 of the 50 strains were all 891nt length coding 297 amino acids. The result of molecular identification of the 50 strains is HEV71. Phylogenetic analysis indicated that 48 EV71 isolates belonged to subgenotype C4a and 2 EV71 isolates belonged to genotype A. From 2009 to 2010, the pathogen of HFMD cases were EV71 strains in Yunnan province, which were co-evolved with isolates from other provinces in mainland of China. There was no significant difference found in the whole sequence of VP1 gene of the strains isolated from different regions or under different diseases occurred, but the spread of genetype A appared in Yunnan Province in 2009.

Comparison of mesenchymal stem cells released from poly(N-isopropylacrylamide) copolymer film and by trypsinization.

Temperature-responsive platforms containing poly(N-isopropylacrylamide) (PNIPAAm) have been developed as an effective substitute for enzymatic treatment to recover adherent cells, but it remains unclear whether this alternative harvesting method tends to support stem cells preserving them being primitive. This study mainly investigated the biological properties of mesenchymal stem cells derived from rat bone marrow and human adipose tissue (BM-MSCs and AT-MSCs) after being cultured on PNIPAAm copolymer films and recovered by temperature drop, and compared the cells harvested from glass coverslips with trypsinization as controls. The experimental results demonstrated that after three serial passages, the released MSCs from thermal liftoff showed no significant differences in cell morphology, immunophenotype and osteogenesis for BM-MSCs or adipogenesis for AT-MSCs, but had higher viability, stronger proliferation and higher adipogenic differentiation for BM-MSCs or higher osteogenic differentiation for AT-MSCs compared with the trypsinization group. Besides, more proteins remained around or within the cell membranes upon temperature drop. It is concluded that cell detachment with more extracellular matrix proteins facilitates the maintenance of membrane proteins, and accordingly preserves MSC properties related to viability, proliferation and differentiation to some extent. This indicates that the PNIPAAm copolymer films and their matching cooling treatment can be used as effective alternatives to the existing culture substrates and traditional enzymatic digestion for MSCs.