First-principles prediction of ferroelectric Janus Si2XY (X/Y = S/Se/Te, X ≠ Y) monolayers with negative Poisson's ratios.

Nowadays, two-dimensional (2D) materials with Janus structures evoke much attention due to their unique mechanical and electronic properties. In this work, Janus Pma2-Si2XY (X/Y = S/Se/Te, X ≠ Y) ferroelectric monolayers are firstly proposed and systematically investigated by first-principles calculations. These monolayers exhibit remarkable mechanical properties, including small Young's modulus values, negative Poisson's ratios (NPRs) and large critical strains, reflecting their exceptional flexibility and stretchability. More strikingly, the novel structures of Si2STe and Si2SeTe also endow them with in-plane spontaneous polarization (Ps) and low energy barrier for phase transition, with Ps and energy barrier values being 1.632 × 10-10 C m-1 and 159 meV for Si2STe and 1.149 × 10-10 C m-1 and 196.6 meV for Si2SeTe. The ab initio molecular dynamics (AIMD) simulations reveal high Curie temperatures (Tc) for Si2STe and Si2SeTe, ranging between 1300 K and 1400 K. Additionally, Si2XY monolayers exhibit high anisotropic carrier mobility (∼103 cm2 V-1 s-1) and an extraordinary light absorption coefficient (∼105 cm-1). Our research not only broadens the family of 2D Janus ferroelectric materials, but also demonstrates their potential applications in nanomechanical, nanoelectronic and optoelectronic devices.

TaMIR397-6A and -6B Homoeologs Encode Active miR397 Contributing to the Regulation of Grain Size in Hexaploid Wheat.

Wheat is one of the most important food crops globally, and understanding the regulation of grain size is crucial for wheat breeding to achieve a higher grain yield. MicroRNAs (miRNAs) play vital roles in plant growth and development. However, the miRNA-mediated mechanism underlying grain size regulation remains largely elusive in wheat. Here, we report the characterization and functional validation of a miRNA, TamiR397a, associated with grain size regulation in wheat. The function of three TaMIR397 homoeologs was determined through histochemical ß-glucuronidase-dependent assay. MiRNA expression was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR), and the function of TamiR397a was validated through its transgenic overexpression and repression in wheat. It was found that TaMIR397-6A and TaMIR397-6B encode active TamiR397a. The expression profiling indicated that TamiR397a was differentially expressed in various tissues and gradually up-regulated during grain filling. The inhibition of TamiR397a perturbed grain development, leading to a decrease in grain size and weight. Conversely, the overexpression of TamiR397a resulted in increased grain size and weight by accelerating the grain filling process. Transcriptome analysis revealed that TamiR397a regulates a set of genes involved in hormone response, desiccation tolerance, regulation of cellular senescence, seed dormancy, and seed maturation biological processes, which are important for grain development. Among the down-regulated genes in the grains of the TamiR397a-overexpressing transgenic plants, 11 putative targets of the miRNA were identified. Taken together, our results demonstrate that TamiR397a is a positive regulator of grain size and weight, offering potential targets for breeding wheat with an increased grain yield.

The application of new gastric cancer screening score system for gastric cancer screening and risk assessment of gastric precancerous lesions in China.

Objective: To evaluate the value of new gastric cancer screening score system for risk assessment of gastric precancerous lesions.Methods: A total of 520 patients were enrolled after the examination of endoscopy at Endoscopy Center, Department of Gastroenterology, from June 2018 to December 2021. The patients were divided into three groups according to age, gender, serum helicobacter pylori antibody test, pepsinogen I (PGI), pepsinogen II (PGII), pepsinogen I/II ratio (PGR) and gastrin-17 test results before endoscopy: Group A defined as low-risk group (0-11 points), Group B defined as middle-risk group (12-16 points), Group C defined as high-risk group (17-23 points). The detection rates of gastric cancer and atrophic gastritis in three groups were analyzed. According to the range and degree of atrophy/intestinal metaplasia, patients were divided into five groups on the basis of OLGA/OLGIM staging system. The levels of PG I, PG II and PGR were compared between different groups, and the correlation between new gastric cancer screening score system and OLGA/OLGIM staging system were evaluated. Statistical analysis was accomplished by ANOVA, chi-square test and Gamma coefficient analysis.Results: A total of 520 patients were enrolled. 268 patients were classified into group A,222 patients into group B and 30 patients into group C, respectively. According to the pathological results, 281 cases were non-atrophic gastritis, 230 cases atrophic gastritis and 9 cases gastric cancer. For OLGA staging system, 281 patients were divided into stage-0 group, 121 patients into stage-I group, 72 patients into stage-II group, 33 patients into stage-III group and 13 patients into stage-IV groups. The PGI and PGR level correlated inversely with the rising OLGA stages (F = 3.028, p = .016, F = 6.036, p < .001). For OLGIM staging system, 252 patients were divided into stage-0 group, 137 patients into stage-I group, 80 patients into stage-II group, 36 patients into stage-III group and 15 patients into stage-IV group. The PGR level correlated inversely with the rising OLGIM stages (F = 3.466, p＝.007). The detection rates of gastric cancer and atrophic gastritis in Group C were much higher than other groups. (X2 = 14.727, p < .001; X2 = 51.280, p < .001). Gamma coefficient analysis showed significant correlations between OLGA/OLGIM and the new gastric cancer screening score system (p < .001).Conclusions: The new gastric cancer screening score system is closely linked with histological OLGA/OLGIM staging system in the risk assessment of gastric precancerous lesions. The role of new gastric cancer screening score system in future gastric precancerous lesions screening and high risk population identifying was promising.

Electrostatic gating dependent multiple band alignments in ferroelectric VS2/Ga2O3 van der Waals heterostructures.

Two-dimensional (2D) van der Waals (vdW) heterostructures with spontaneous intrinsic ferroelectrics play an essential role in ferroelectric memories. Also, the reversal of polarized directions induces band alignment transitions among different types to provide a new path for multifunctional devices. In this work, the structural and electronic properties of 2D VS2/Ga2O3 vdW heterostructures under different polarizations were investigated using first-principles calculations with the vdW correction of the DFT-D2 method. The results reveal that the polarized direction of a 2D Ga2O3 monolayer can cause a distinct band structure reversion from a metal to a semiconductor due to the shift of band alignment induced by the interlayer charge transfer. Moreover, the VS2/P↑ Ga2O3 heterostructures retain type-I and type-II band alignments in the majority and minority channel, respectively, under an external electric field. Interestingly, applying the external electric field for VS2/P↓ Ga2O3 heterostructures can lead to a transition from type-II to type-I in the majority channel, and from type-II to type-III in the minority channel. Our work provides a feasible way to realize 2D VS2/Ga2O3 vdW heterostructures for potential applications in ferroelectric memories and electrostatic gating dependent multiple band alignment devices.

Robust ferroelectricity in low-dimensional δ-SiX (X = S/Se): a first-principles study.

Low-dimensional ferroelectric materials hold great promise for application in nonvolatile memory devices. In this work, ferroelectricity in two-dimensional monolayers and one-dimensional nanowires based on δ-SiX (X = S and Se) materials with spontaneous polarization and ferroelectric switching energy barriers has been predicted using the first-principles method. The results show that the intrinsic ferroelectric values due to spontaneous polarization of 2D-SiS, 2D-SiSe, 1D-SiS and 1D-SiSe are 3.22 × 10-10 C m-1, 3.00 × 10-10 C m-1, 7.58 × 10-10 C m-1 and 6.81 × 10-10 C m-1, respectively. The Monte Carlo simulations and ab initio molecular dynamics (AIMD) simulations both indicate that 2D-SiX and 1D-SiX exhibit room-temperature ferroelectricity. Moreover, the polarization and ferroelectric switching energy barrier can be tuned by applying a strain. Notably, spontaneous spin polarization can be achieved by hole doping in one-dimensional nanowires. Our findings not only broaden the research field of low-dimensional ferroelectric materials, but also provide a promising platform for the application of novel nano-ferroelectric devices.

Observation of General Entropy-Enthalpy Compensation Effect in the Relaxation of Wrinkled Polymer Nanocomposite Films.

Surface-textured polymer nanocomposite (PNC) films are utilized in many device applications, and therefore understanding the relaxation behavior of such films is important. By extending an in situ wrinkle relaxation method, we observed that the thermal stability of wrinkled PNC films, both above and below the glass transition temperature (Tg), is proportional to a film's nanoparticle (polymer grafted and bare) concentration, with a slope that changes sign at a compensation temperature (Tcomp) that is determined to be in the vicinity of the film's Tg. This provides unambiguous confirmation of entropy-enthalpy compensation (EEC) as a general feature of PNC films, implying that the stability of PNC films changes from being enhanced to becoming diminished by simply passing through this characteristic temperature, a phenomenon having evident practical ramifications. We suggest EEC will also arise in films where residual stresses are associated with the film fabrication process, which is relevant to nanotech device applications.

Vertically oriented nanoporous block copolymer membranes for oil/water separation and filtration.

The separation of oil from water and filtration of aqueous solutions and dispersions are critical issues in the processing of waste and contaminated water treatment. Membrane-based technology has been proven as an effective method for the separation of oil from water. In this research, novel vertical nanopores membrane, via oriented cylindrical block copolymer (BCP) films, suitable for oil/water filtration has been designed, fabricated and tested. We used a ∼100 nm thick model poly(styrene-block-methymethacrylate) (PS-b-PMMA) BCP as the active top nanofiltration layer, processed using a roll-to-roll (R2R) method of cold zone annealing (CZA) to obtain vertical orientation, followed by ultraviolet (UV) irradiation selective etch of PMMA cylinders to form vertically oriented nanopores as a novel feature compared to meandering nanopores in other reported BCP systems. The cylindrical nanochannels are hydrophilic, and have a uniform pore size (∼23 nm), a narrow pore size distribution and a high nanopore density (∼420 per sq. micron). The bottom supporting layer is a conventional microporous polyethersulfone (PES) membrane. The created asymmetric membrane is demonstrated to be effective for oil/water extraction with a modestly high throughput rate comparable to other RO/NF membranes. The molecular weight dependent filtration of a water soluble polymer, PEO, demonstrates the broader applications of such membranes.

Tuning the Relaxation of Nanopatterned Polymer Films with Polymer-Grafted Nanoparticles: Observation of Entropy-Enthalpy Compensation.

Polymer films provide a versatile platform in which complex functional relief patterns can be thermally imprinted with a resolution down to few nanometers. However, a practical limitation of this method is the tendency for the imprinted patterns to relax ("slump"), leading to loss of pattern fidelity over time. While increasing temperature above glass transition temperature ( Tg) accelerates the slumping kinetics of neat films, we find that the addition of polymer-grafted nanoparticles (PGNP) can greatly enhance the thermal stability of these patterns. Specifically, increasing the concentration of poly(methyl methacrylate) (PMMA) grafted titanium dioxide (TiO2) nanoparticles in the composite films slows down film relaxation dynamics, leading to enhanced pattern stability for the temperature range that we investigated. Interestingly, slumping relaxation time is found to obey an entropy-enthalpy compensation (EEC) relationship with varying PGNP concentration, similar to recently observed relaxation of strain-induced wrinkling in glassy polymer films having variable film thickness. The compensation temperature,  Tcomp was found to be in the vicintity of the bulk  Tg of PMMA. Our results suggest a common origin of EEC relaxation in patterned polymer thin films and  nanocomposites.

The correlation between histological gastritis staging- 'OLGA/OLGIM' and serum pepsinogen test in assessment of gastric atrophy/intestinal metaplasia in China.

BACKGROUND: Serum pepsinogen (PG) test, as an indicator of gastric mucosal atrophy, reflects the functional and morphologic status of gastric mucosal and it is suggested to serve as a useful predictive marker for patients with gastric cancer (GC). The available classifications of gastritis, known as the Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastritis Intestinal Metaplasia (OLGIM), integrating the severity and topography of atrophy/intestinal metaplasia (IM), have been gradually accepted and used in screening for GC in recent years. GOALS: To assess whether serum pepsinogen test, including PGI, PGII, PGI/PGII and gastrin-17 (G-17) could reflect the extent and topography of gastric mucosal atrophy/IM. Furthermore, to discuss the relationship between OLGA/OLGIM staging system and serum pepsinogen test in assessment of gastric atrophy/IM. METHODS: The OLGA/OLGIM ranks the gastric staging according to both the topography and the severity of gastric atrophy/IM. A retrospective study was conducted with 331 patients who underwent endoscopy with consecutive biopsy sampling and reassessed according to OLGA/OLGIM staging system. Serum pepsinogen test, including PGI, PGII, PGI/PGII and G-17, as well as serological Helicobacter pylori (Hp) antibody were also measured. Results were presented as gastritis stage, serum pepsinogen level and Hp status. Baseline characteristics were compared using analysis of variance (ANOVA) test for continuous data and Pearson's χ2 test for categorical data. A logistic regression model was used for the correlation analysis between OLGA/OLGIM and serological pepsinogen test. RESULTS: A total of 177 non-atrophic gastritis and 154 atrophic gastritis were analyzed, among which 40 were antrum atrophy, 32 were corpus atrophy and 82 were pan-atrophy. All patients were assessed applying the OLGA/OLGIM criteria with a mean age of 54.7 ± 10.8 years. Patients among OLGA/OLGIM Stage III-IV were presented with a lower level of serum PGI and PGI/PGII (p < .05), especially for Stage IV (p = .01). For both Hp-positive patients and Hp-negative patients according to OLGA system, PGI/PGII level correlated inversely with the rising stage (p = .022; p = .028). As for OLGIM system, similar difference can be seen in PGI/PGII level in either Hp-positive patients, or Hp-negative patients (p = .036; p = .013). In addition, the percentage of G-17 <1 pmol/L combined with PG-negative in antrum atrophy group was much higher than that of non-atrophy group and corpus atrophy group (25 versus 15.8 versus 6.3%) (p = .029). The proportion of G-17 > 15 pmol/L combined with PG-positive was apparently higher in corpus atrophy group, compared with other two groups (25 versus 11.3 versus 8.1%) (p = .023). Logistic regression modeling showed there exist significant connections between OLGA/OLGIM stages and serum pepsinogen test in patient stratification for gastric mucosal atrophy assessment (p < .001, p < .001). CONCLUSIONS: Serum pepsinogen test has a strong correlation with OLGA/OLGIM gastritis stage and could provide important information in assessment of atrophy/intestinal metaplasia.

[Syndrome Features of Chinese Medicine in Hyperlipidemia Patients of Han, Uyghur, Kazakh Na- tionalities in Xinjiang Uyghur Autonomous Region].

Objective To observe distribution laws and features of syndrome types of Chinese medicine (CM) in hyperlipidemia patients of Han, Uyghur, Kazakh nationalities in Xinjiang Uyghur Auton- omous Region. Methods Using cluster random sampling, 1 410 hyperlipidemia patients (18 -70 years old ) were recruited from Urumqi, Turpan, Altay, Ili, Aksu, Hetian in Xinjiang Uyghur Autonomous Re- gion. The general condition, susceptible factors, classification of blood lipids, complications, syndromes of CM, tongue figure, etc. clinical data were investigated using self-formulated Epidemiological Investiga- tion Questionnaire on Susceptible Factors in Different Nationalities of Hyperlipemia Patients in Xinjiang (abbreviated as Questionnaire thereafter). Factor analysis and cluster analysis were performed. Results Cronbach's coefficient for the 54 syndrome items in Questionnaire was 0.891, Kaiser-Meyer-Olkin (KMO) 0. 897, Sig <0.05 in Bartlett's sphericity test. Seventeen common factors were obtained using principal component analysis (PCA). Totally 54 common symptoms of hyperlipidemia were screened, which were then divided into 17 groups with 1 -6 symptoms in each group. F4 (soreness and weakness of waist and knees, sour pain in joints and muscles, body numbness, heavy body sensation, cold limbs), F5 (frequent and clear nocturia, dysuria,-dribble of urine, frequent urination at night), F10 (thirsty, no desire for water, tastelessness, hydroadipsia) , F12 (a white complexion with puffiness, hid- ing fever, hypoactive sexual desire) , and F17 (enuresis) were merged as Shen yang deficiency (SYD) ; F2 (fatigue, drowsiness, depression, spiritlessness, fatigue and disinclination to talk) and F15 (poor ap- petite) were merged as Pi-qi deficiency (PQD) ; F3 (dry mouth and dry pharynx, thirsty, propensity for water, bitter mouth, greasy mouth, stingy mouth, irritability and upset) and F16 (dark red tongue proper, greasy tongue fur) were merged as damp-heat trapped in Pi (DHTP). Results of cluster analysis showed that Pi-Shen deficiency (PSD) was most often seen in hyperlipidemia, and main syndrome types were sequenced from high to low as Pi-Shen deficiency type (46. 2%, 652/1 410) , blockage of cardiac vessels type ( 31. 1% , 438/1 410 ), phlegm and blood stasis internal resistance type ( 13. 3% , 187/1 410), Pi-deficiency induced damp abundance type (8. 3%, 123/1 410), Gan-Shen yin deficiency type (0. 7%, 10/1 410). Conclusions Deficiency syndrome was dominant in hyperlipidemia patients of Xinjiang Uyghur Autonomous Region. Phlegm turbidity, damp heat, and etc. were often complicated. The complex situation was manifested to be involved in multiple organs, qi-blood-fluid mixed disease.

[Effect of ERK1/2 pathway in the expression of MHC-â ¡of intestinal dendritic cells in viscerally hypersensitive rats].

OBJECTIVE: To study the phenotypic alteration of intestinal dendritic cells (DC) in a rat model of irritable bowel syndrome (IBS) and the change of mitogen-activated protein kinase (MAPK) signaling pathway, in order to explore the potential mechanism of ERK1/2 pathway mediation in abnormal DC immune response. METHODS: IBS rat model was established by combining neonatal maternal separation and colorectal distension in 10 SD rats, and 10 healthy rats served as controls. Visceral sensitivity was evaluated with abdominal withdrawal reflex (AWR). Mesenteric lymph node DC (MLNDC) was isolated and purified by magnetic label-based technique after modeling. Expression of surface major histocompatibility complex (MHC)-Ⅱin control rats was determined by flow cytometric analyses. Western-blot was used to determine the expression of MHC-Ⅱ, p-p38, p38, phosphorylated extracellular regulated protein kinase (p-ERK1/2), ERK1/2, phosphorylated c-Jun N-terminal kinase (p-JNK), and JNK in MLNDC. RESULTS: Visceral sensitivity was significantly higher in the IBS group than in the control group. The purity of the OX62 positivity MLNDC following magnetic sorting was about 85.57%±7.67%. MLNDC in the control group expressed high level of MHC-Ⅱ. The expression of MHC-Ⅱ and p-ERK1/2 in MLNDC in the IBS group were higher than those in the control group (1.05±0.13 vs 0.67±0.18, t=-2.973, P=0.041; 3.21±0.48 vs 2.34±0.85, t=-3.130, P=0.035); while there was no significant difference in the expressions of p-JNK and p-p38 compared with the control groups (0.95±0.17 vs 0.76±0.36, t=0.808, P=0.464; 1.07±1.13 vs 1.19±0.91, t=0.137, P=0.897). CONCLUSION: The intestinal DC in IBS rats show a upregulated expression of MHC-Ⅱ, which may be related to the activation of intracellular ERK1/2 pathway.

Understanding physical exercise among individuals with substance use disorders using an integrated theoretical perspective of the health action process approach and theory of planned behavior.

Introduction: Physical exercise is considered a useful non-pharmacological adjunctive treatment for promoting recovery from substance use disorders (SUD). However, adherence to physical exercise treatments is low, and little is known about what factors are associated with the initiation and maintenance of physical exercise behaviors. The aim of this study was to explore the psychosocial factors underlying these behaviors in individuals with SUD using an integrated theoretical model based on the health action process approach (HAPA) and the theory of planned behavior (TPB). Methods: A total of 1,197 individuals with SUDs (aged 37.20 ± 8.62 years) were recruited from 10 compulsory isolation drug rehabilitation centers in Zhejiang Province via convenience sampling according to a set of inclusion criteria. Self-reported data were collected to assess task self-efficacy (TSE), maintenance self-efficacy (MSE), recovery self-efficacy (RSE), outcome expectations (OE), action planning (AP), coping planning (CP), social support (SS), subjective norms (SN), attitude behavior (AB), behavioral intention (BI), perceived behavioral control (PBC), risk perception (RP), exercise stage, and exercise behavior in this integrated model. ANOVA and structural equation modeling (SEM) were used to evaluate this model. Results: One-way ANOVA revealed that the majority of the moderating variables were significantly different in the exercise phase. Further SEM showed that the model fit the data and revealed several important relationships. TSE, RP, SS, AB, and SN were indirectly associated with physical exercise behavior in individuals with SUD through the BI in the SUD initiation stage. In addition, PBC was directly related to physical exercise behavior in individuals with SUD. In the maintenance stage, MSE, AP, CP and exercise behavior were significantly related. Moreover, AP and CP were mediators of BI and MSE. Conclusion: This study is the first attempt to integrate patterns of physical exercise behavior in individuals with SUD. The HAPA-TPB integration model provides a useful framework for identifying determinants of physical exercise behavioral intentions and behaviors in individuals with SUD and for explaining and predicting the initiation and maintenance of physical exercise behaviors in these individuals. Moreover, the model provides scientific guidance for the enhancement of physical exercise adherence in individuals with SUD.

Microstructural Evolution, Mechanical Properties and Tribological Behavior of B4C-Reinforced Ti In Situ Composites Produced by Laser Powder Bed Fusion.

Based on the advantage of rapid net-shape fabrication, laser powder bed fusion (LPBF) is utilized to process B4C-reinforced Ti composites. The effect of volumetric energy density (VED) on the relative density, microstructural evolution, tensile properties and wear behaviors of B4C-reinforced Ti composites were systematically investigated. The LPBF-ed samples with high relative density (>99%) can be achieved, while the pores and un-melted powders can be observed in the sample owing to the low energy input (33 J/mm3). The additive particulates B4C were transformed into needle-like TiB whiskers with nano-scale while C dissolved in the Ti matrix. Fine-scale grains (<10 µm) with random crystallographic orientation can be achieved and the residual stress shows a downtrend as the VED increases. Through the analysis of the tensile and wear tests, the sample at 61 J/mm3 VED showed a good combination of strength and wear performance, with an ultimate tensile strength of 951 MPa and a wear rate of 3.91 × 10-4 mm3·N-1m-1. The microstructural evolution in VED changes and the corresponding underlying strengthening mechanisms of LPBF-ed Ti + B4C composites are conducted in detail.

Characterization of thioredoxin gene TaTrxh9 associated with heading-time regulation in wheat.

Thioredoxins (Trxs) are thiol-disulfide oxidoreductase proteins that play important roles in a spectrum of processes linking redox regulation and signaling in plants. However, little is known about Trxs and their biological functions in wheat, one of the most important food crops worldwide. This study reports the identification and functional characterization of an h-type Trx gene, TaTrxh9, in wheat. Three homoeologs of TaTrxh9 were identified and the sequences in the coding region were highly consistent among the homoeologs. Protein characterization showed that a conserved Trx_family domain, as well as a typical active site with a dithiol signature (WCGPC), was included in TaTrxh9. Structural modeling demonstrated that TaTrxh9 could fold into a canonical thioredoxin structure consisting of five-stranded antiparallel beta sheets sandwiched between four alpha helices. The insulin disulfide reduction assay demonstrated that TaTrxh9 was catalytically active in vitro. TaTrxh9 overexpression in the Arabidopsis mutant trxh9 complemented the abnormal growth phenotypes of the mutant, suggesting is functionality in vivo. The transcription level of TaTrxh9 was higher in leaf tissues and it was differentially expressed during the development of wheat plants. Interestingly, barley stripe mosaic virus-mediated suppression of TaTrxh9 shortened the seedling-heading period of wheat. Furthermore, CRISPR-Cas9 mediated gene knockout confirmed that the TaTrxh9 mutation resulted in early heading of wheat. To our knowledge, this study is the first to report that Trxh is associated with heading-time regulation, which lays a foundation for further exploring the biological function of TaTrxh9 and provides new ideas for molecular breeding focusing on early heading in wheat.

Enhanced resistance to decay of imprinted nanopatterns in thin films by bare nanoparticles compared to polymer-grafted nanoparticles.

We extend a previous study on the influence of nanoparticles on the decay of nanoimprinted polymer film patterns to compare the effects of "bare" silica (SiO2) nanoparticles and SiO2 nanoparticles with grafted polymer layers having the same chemical composition as the polymer matrix. This method involves nanoimprinting substrate-supported polymer films using a pattern replicated from a digital versatile disc (DVD), and then annealing the patterned polymer nanocomposite films at elevated temperatures to follow the decay of the topographic surface pattern with time by atomic force microscopy imaging after quenching. We quantified the relaxation of the pattern height ("slumping") and determined the relaxation time τ for this pattern decay process as a function of nanoparticle filler type and concentration to determine how nanoparticle additives influence relative film stability. Attractive interactions between the bare nanoparticles and the polymer matrix significantly enhance the thermal resilience of the nanopatterns to decay, compared to those of the particle brushes, wherein the particle core interactions are screened from the matrix via the brush layer. A novel aspect of this method is that it readily lends itself to in situ film relaxation measurements in a manufacturing context. We observe that the relaxation time of the pattern relaxation exhibits entropy-enthalpy compensation in the free energy parameters governing the pattern relaxation process as a function of temperature, irrespective of the NP system used, consistent with our previous experimental and computational studies.

Preparation and evaluation of chitosan-polyvinyl alcohol/polyhexamethylene guanidine hydrochloride antibacterial dressing to accelerate wound healing for infectious skin repair.

BACKGROUND: Wound infections, especially multidrug-resistant (MDR) bacterial infections, are a major challenge in clinical medicine. METHODS: In this study, a new type of antibacterial sponge was prepared from a solution containing a chitosan-polyvinyl alcohol (CTS-PVA) emulsion with added polyhexamethylene guanidine hydrochloride (PHMG) in a homogeneous medium using lyophilization technology. The antibacterial ability of and CTS-PVA/PHMG sponge against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Methicillin-resistant Staphylococcus aureus, multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Acinetobacter baumannii in vitro. The structure and physical properties were characterized. The sponge dressing was tested in a Pseudomonas aeruginosa-infected full-thickness mouse skin wound defect model. The effects were evaluated by wound area measurement and histological analysis. RESULTS: The CTS-PVA/PHMG sponge showed broad-spectrum antibacterial ability, including for MDR bacterial stains from clinical sources, while maintaining excellent physicochemical properties, including a high swelling degree and good moisture retention capability. Scanning electron microscopy images displayed the surface morphology of the CTS-PVA/PHMG sponge dressing. The detection of the wound healing rate and histological analysis supported that the new dressing can alleviate the inflammation and accelerate the healing speed of infected wounds and in vivo. CONCLUSIONS: CTS-PVA/PHMG sponge shows broad-spectrum antibacterial activity, which can provide a new pathway for clinical prevention and treatment of superbug-infected wounds.

Control of Phase Morphology of Binary Polymer Grafted Nanoparticle Blend Films via Direct Immersion Annealing.

While the phase separation of binary mixtures of chemically different polymer-grafted nanoparticles (PGNPs) is observed to superficially resemble conventional polymer blends, the presence of a "soft" polymer-grafted layer on the inorganic core of these nanoparticles qualitatively alters the phase separation kinetics of these "nanoblends" from the typical pattern of behavior seen in polymer blends and other simple fluids. We investigate this system using a direct immersion annealing method (DIA) that allows for a facile tuning of the PGNPs phase boundary, phase separation kinetics, and the ultimate scale of phase separation after a sufficient "aging" time. In particular, by switching the DIA solvent composition from a selective one (which increases the interaction parameter according to Timmerman's rule) to an overall good solvent for both PGNP components, we can achieve rapid switchability between phase-separated and homogeneous states. Despite a relatively low and non-classical power-law coarsening exponent, the overall phase separation process is completed on a time scale on the order of a few minutes. Moreover, the roughness of the PGNP blend film saturates at a scale that is proportional to the in-plane phase separation pattern scale, as observed in previous blend and block copolymer film studies. The relatively low magnitude of the coarsening exponent n is attributed to a suppression of hydrodynamic interactions between the PGNPs. The DIA method provides a significant opportunity to control the phase separation morphology of PGNP blends by solution processing, and this method is expected to be quite useful in creating advanced materials.

Down-Regulation of miR-301a-3p Reduces Burn-Induced Vascular Endothelial Apoptosis by potentiating hMSC-Secreted IGF-1 and PI3K/Akt/FOXO3a Pathway.

Vascular endothelium dysfunction plays a pivotal role in the initiation and progression of multiple organ dysfunction. The mesenchymal stem cell (MSC) maintains vascular endothelial barrier survival via secreting bioactive factors. However, the mechanism of human umbilical cord MSC (hMSC) in protecting endothelial survival remains unclear. Here, we found IGF-1 secreted by hMSC suppressed severe burn-induced apoptosis of human umbilical vein endothelial cells (HUVECs) and alleviated the dysfunction of vascular endothelial barrier and multiple organs in severely burned rats. Severe burn repressed miR-301a-3p expression, which directly regulated IGF-1 synthesis and secretion in hMSC. Down-regulation of miR-301a-3p decreased HUVECs apoptosis, stabilized endothelial barrier permeability, and subsequently protected against multiple organ dysfunction in vivo. Additionally, miR-301a-3p negatively regulated PI3K/Akt/FOXO3 signaling through IGF-1. Taken together, our study highlights the protective function of IGF-1 against the dysfunction of multiple organs negatively regulated by miR-301a-3p, which may provide the theoretical foundation for further clinical application of hMSC.

MIR-190B Alleviates Cell Autophagy and Burn-Induced Skeletal Muscle Wasting via Modulating PHLPP1/Akt/FoxO3A Signaling Pathway.

INTRODUCTION: Cell autophagy is an important material recycling process and is involved in regulating many vital activities under both physiological and pathological conditions. However, the mechanism of autophagy regulating burn-induced skeletal muscle wasting still needs to be elucidated. METHODS: The rat burn model with 30% total body surface area and L6 cell line were used in this study. An immunofluorescence assay was used to detect autophagic levels. MicroRNA array and real-time PCR were employed to measure miR-190b levels, and its influence on PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1) protein translation was estimated using luciferase reporter assay. The expression levels of autophagy-related proteins were analyzed by Western blot. Skeletal muscle wasting was evaluated by the ratio of tibias anterior muscle weight to body weight. RESULTS: Our study demonstrates that burn injury promotes expression of the autophagy-related proteins light chain 3 (LC3) and Beclin-1, suppresses expression of Akt and Forkhead box O (FoxO) 3a protein phosphorylation, and increases PHLPP1 protein level which is required for Akt dephosphorylation. miR-190b, the regulator of PHLPP1 protein translation, also significantly decreases after burn injury. Ectopic expression of miR-190b in L6 myoblast cell downregulates PHLPP1 protein expression, elevates Akt and FoxO3a phosphorylation, and subsequently reduces cell autophagy. Finally, suppressing autophagy with 3-methyladenine represses the protein expression of LC3 and Beclin-1 and mitigates burn-induced skeletal muscle wasting. CONCLUSION: Burn injury induced skeletal muscle cell autophagy and subsequently resulted in skeletal muscle wasting via regulating miR-190b/PHLPP1/Akt/FoxO3a signaling pathway.

Biopsy strategies for endoscopic screening of pre-malignant gastric lesions.

Operative Link on Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) were adopted to evaluate gastric risk stratification in five biopsy samples. This study aimed to evaluate the degree of gastric atrophy (GA) and intestinal metaplasia (IM) in five locations to detect a more representative biopsy sample in gastric cancer (GC) screening. Our study enrolled 368 patients and 5 biopsy pieces were acquired from them. Gastric risk stratification was calculated by OLGA and OLGIM staging system. The results revealed that the IM score in the incisura angularis was higher than that in the larger and lesser curvature of corpus mucosa (p = 0.037 and p = 0.030, respectively) and the IM score in the lesser curvature of antrum mucosa was higher than that in the incisura angularis mucosa (p = 0.018). IM is more frequently observed in the angulus region than in the lesser curvature of corpus in the mild degree (p = 0.004) and mild IM lesions in the lesser curvature of antrum were more frequently observed than in the incisura angularis mucosa (p = 0.004), Four biopsy pieces protocol (larger curvature and lesser curvature of the antrum, lesser curvature of the corpus and angulus) demonstrated accurate consistency (97.83% and 98.37%, respectively) with a Kendall's tau-b of higher than 0.990, along with low misdiagnosis rates of OLGA and OLGIM (III + IV) (9.76% and 5.00%, respectively). Three biopsy pieces protocol (lesser curvature of the antrum and corpus, angulus biopsy) in OLGA and OLGIM staging system was close to the standard protocol (five biopsy specimens) with a consistency of 94.84% and 94.29% and has a Kendall's tau-b higher than 0.950 and diagnostic omission rates of 9.76% and 5.00%, respectively, which was exactly the same with the four biopsy pieces protocol. Furthermore, it had the second-highest Youden index (0.902 and 0.950, respectively) and area under the ROC curve (0.992 and 0.996, respectively) for the screening of high-risk GC by OLGA and OLGIM stages. Thus, we recommended the angulus and the lesser curvature of antrum as a conventional biopsy and three biopsy pieces for further GC risk screening.