The Anti-Microbial Peptide Citrocin Controls Pseudomonas aeruginosa Biofilms by Breaking Down Extracellular Polysaccharide.

Citrocin is an anti-microbial peptide that holds great potential in animal feed. This study evaluates the anti-microbial and anti-biofilm properties of Citrocin and explores the mechanism of action of Citrocin on the biofilm of P. aeruginosa. The results showed that Citrocin had a significant inhibitory effect on the growth of P. aeruginosa with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 0.3 mg/mL. All five concentrations (1/4MIC, 1/2MIC, MIC, 2MIC, and 4MIC) of Citrocin inhibited P. aeruginosa biofilm formation. Citrocin at the MIC, 2MIC and 4MIC removed 42.7%, 76.0% and 83.2% of mature biofilms, respectively, and suppressed the swarming motility, biofilm metabolic activity and extracellular polysaccharide production of P. aeruginosa. Metabolomics analysis indicated that 0.3 mg/mL of Citrocin up- regulated 26 and down-regulated 83 metabolites, mainly comprising amino acids, fatty acids, organic acids and sugars. Glucose and amino acid metabolic pathways, including starch and sucrose metabolism as well as arginine and proline metabolism, were highly enriched by Citrocin. In summary, our research reveals the anti-biofilm mechanism of Citrocin at the metabolic level, which provides theoretical support for the development of novel anti-biofilm strategies for combatting P. aeruginosa.

Bendable and Chemically Stable Metal-Organic Hybrid Membranes for Molecular Separation.

Crystalline porous metal-organic materials are ideal building blocks for separation membranes because of their molecular-sized pores and highly ordered pore structure. However, creating ultrathin, defect-free crystalline membranes is challenging due to inevitable grain boundaries. Herein, we reported an amorphous metal-organic hybrid (MOH) membrane with controlled microporosity. The synthesis of the MOH membrane entails the use of titanium alkoxide and organic linkers containing di/multicarboxyl groups as monomers in the polymerization reaction. The resultant membranes exhibit similar microporosity to existing molecular sieve materials and high chemical stability against harsh chemical environments owing to the formation of stable Ti-O bonds between metal centers and organic linkers. An interfacial polymerization is developed to fabricate an ultrathin MOH membrane (thickness of the membrane down to 80 nm), which exhibits excellent rejections (>98% for dyes with molecular weights larger than 690 Da) and high water permeance (55 L m-2 h-1 bar-1). The membranes also demonstrate good flexibility, which greatly improves the processability of the membrane materials.

Thiolation-Based Protein-Protein Hydrogels for Improved Wound Healing.

The limitations of protein-based hydrogels, including their insufficient mechanical properties and restricted biological functions, arise from the highly specific functions of proteins as natural building blocks. A potential solution to overcome these shortcomings is the development of protein-protein hydrogels, which integrate structural and functional proteins. In this study, a protein-protein hydrogel formed by crosslinking bovine serum albumin (BSA) and a genetically engineered intrinsically disordered collagen-like protein (CLP) through Ag─S bonding is introduced. The approach involves thiolating lysine residues of BSA and crosslinking CLP with Ag+ ions, utilizing thiolation of BSA and the free-cysteines of CLP. The resulting protein-protein hydrogels exhibit exceptional properties, including notable plasticity, inherent self-healing capabilities, and gel-sol transition in response to redox conditions. In comparison to standalone BSA hydrogels, these protein-protein hydrogels demonstrate enhanced cellular viability, and improved cellular migration. In vivo experiments provide conclusive evidence of accelerated wound healing, observed not only in murine models with streptozotocin (Step)-induced diabetes but also in zebrafish models subjected to UV-burn injuries. Detailed mechanistic insights, combined with assessments of proinflammatory cytokines and the expression of epidermal differentiation-related proteins, robustly validate the protein-protein hydrogel's effectiveness in promoting wound repair.

Genetically encoded zinc-binding collagen-like protein hybrid hydrogels for wound repair.

Incorporating zinc oxide nanoparticles (ZnOnps) into collagen is a promising strategy for fabricating biomaterials with excellent antibacterial activity, but modifications are necessary due to the low zinc binding affinity of native collagen, which can cause disturbances to the functions of both ZnOnps and collagen and result in heterogeneous effects. To address this issue, we have developed a genetically encoded zinc-binding collagen-like protein, Zn-eCLP3, which was genetically modified by Scl2 collagen-like protein. Our study found that Zn-eCLP3 has a binding affinity for zinc that is 3-fold higher than that of commercialized type I collagen, as determined by isothermal titration calorimetry (ITC). Using ZnOnps-coordinated Zn-eCLP3 protein and xanthan gum, we prepared a hydrogel that showed significantly stronger antibacterial activity compared to a collagen hydrogel prepared in the same manner. In vitro cytocompatibility tests were conducted to assess the potential of the Zn-eCLP3 hydrogel for wound repair applications. In vivo experiments, which involved an S. aureus-infected mouse trauma model, showed that the application of the Zn-eCLP3 hydrogel resulted in rapid wound regeneration and increased expression of collagen-1α and cytokeratin-14. Our study highlights the potential of Zn-eCLP3 and the hybrid hydrogel for further studies and applications in wound repair.

Genetically encoded in situ gelation redox-responsive collagen-like protein hydrogel for accelerating diabetic wound healing.

Genetically encoded collagen-like protein-based hydrogels have demonstrated remarkable efficacy in promoting the healing process in diabetic patients. However, the current methods for preparing these hydrogels pose significant challenges due to harsh reaction conditions and the reliance on chemical crosslinkers. In this study, we present a genetically encoded approach that allows for the creation of protein hydrogels without the need for chemical additives. Our design involves the genetic encoding of paired-cysteine residues at the C- and N-terminals of a meticulously engineered collagen-like recombination protein. The protein-based hydrogel undergoes a gel-sol transition in response to redox stimulation, achieving a gel-sol transition. We provide evidence that the co-incubation of the protein hydrogel with 3T3 cells not only enhances cell viability but also promotes cell migration. Moreover, the application of the protein hydrogel significantly accelerates the healing of diabetic wounds by upregulating the expression of collagen-1α (COL-1α) and Cytokeratin 14 (CK-14), while simultaneously reducing oxidant stress in the wound microenvironment. Our study highlights a straightforward strategy for the preparation of redox-responsive protein hydrogels, removing the need for additional chemical agents. Importantly, our findings underscore the potential of this hydrogel system for effectively treating diabetic wounds, offering a promising avenue for future therapeutic applications.

Interaction matters: Co-viewing facilitates learning from live video streaming for elementary students.

With the development of information technology, co-viewing of live video streaming (LVS) has become a popular online learning method. However, existing studies have found inconsistent results regarding the effects of co-viewing, which could be due to the impact of learner-learner interactions. The present study tested the effects of co-viewing LVS on learning in elementary students, and whether learner-learner interaction moderated students' attention allocation, learning performance (i.e., retention and transfer), learning efficiency, and metacognition. The study used a one-way between-subjects design, with 86 participants assigned randomly to one of three groups: learning alone group, merely co-viewing group, or co-viewing with interaction group. Kruskal-Wallis H tests showed that students in the co-viewing with interaction group allocated more attention to their co-viewer and less to the LVS. However, ANOVA results indicated that they had the best learning performance and metacognition, and demonstrated the highest learning efficiency. Meanwhile, those co-viewing without interaction did not show significantly positive effects compared to those learning alone. The results of informal interviews were largely consistent with the above findings. The findings of the present study suggest the benefits of co-viewing with interaction, providing practical implications for the social context of learning from LVS for elementary students in particular.

Fusarium oxysporum Associated with Fusarium Wilt on Pennisetum sinese in China.

Pennisetum sinese, a versatile and adaptable plant, plays an essential role in phytoremediation, soil reclamation, and fodder production. From 2018 to 2021, the occurrence of Fusarium wilt, with symptoms of foliar blight and internal discoloration of the stem, was observed in Chongqing, China. Pathogens were isolated from the symptomatic leaves. Based on morphological characteristics as well as DNA sequences of the 18S ribosomal RNA (SSU), translation elongation factor 1-α (EF1-α), RNA polymerase II subunit 1 (rpb1), and RNA polymerase II second largest subunit (rpb2) genes, the causal agents were identified as Fusarium oxysporum. Phylogenetic analysis of the combined dataset of EF1-α, rpb1 and rpb2 showed that pathogenic isolates clustered with F. oxysporum strains. The pathogen was reisolated from inoculated and diseased tissues; thus, Koch's postulates were fulfilled. This is the first report of F. oxysporum causing Fusarium wilt on P. sinese in China and worldwide.

[Metabolomics study of Danggui Buxue Tang on treatment of type 2 diabetes mice using UHPLC-Q-TOF-MS].

In this paper, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(UHPLC-Q-TOF-MS)-based metabolomics approach was used to explore the mechanism of Danggui Buxue Tang(DBT) in treating type 2 diabetes mellitus(T2 DM). T2 DM mice model was induced by high-sugar and high-fat fodder and streptozotocin(STZ). The routine indexes such as body weight, blood glucose, plasma insulin, IL-6 and related organ indexes were determined. The UHPLC-Q-TOF-MS technique was used to analyze the metabolism profile of serum samples between the control group and model group, and multiple statistical analysis methods including principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) were used to screen and identify biomarkers. Metabolic profiling revealed 16 metabolites as the most potential biomarkers distinguishing mice in model group from those in control group. The metabolomics pathway analysis(MetPA) was used to investigate the underlying metabolic pathways. Seven major metabolic pathways such the valine, leucine and isoleucine biosynthesis, glycerophospholipid metabolism, primary bile acid biosynthesis, taurine and hypotaurine metabolism, phenylalanine metabolism, fatty acid metabolism and biosynthesis of unsaturated fatty acid. Eleven metabolites such as taurocholic acid and palmitic acid were down-regulated in T2 DM mice, and five metabolites such as L-leucine and leukotriene E4 were up-regulated. Moreover, the sixteen biomar-kers of each administration group had a trend of returning to mice in control group. The significantly-altered metabolite levels indicated that DBT can improve the progression of type 2 diabetes by increasing insulin sensitivity, regulating sugar and lipid metabolism disorders, and relieving inflammation.

Identification of Chemical Markers for the Discrimination of Radix Angelica sinensis Grown in Geoherb and Non-Geoherb Regions Using UHPLC-QTOF-MS/MS Based Metabolomics.

This research aimed to discover chemical markers for discriminating radix Angelica sinensis (RAS) from different regions and to explore the differences of RAS in the content of four active compounds and anti-inflammatory activities on lipopolysacchride (LPS)-induced RAW264.7 cells and calcium antagonists on the HEK 293T cells of RAS. Nine compounds were selected as characteristic chemical markers by ultra-high-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UHPLC-QTOF-MS/MS), based on metabolomics, in order to rapidly discriminate RAS from geoherb and non-geoherb regions. The contents of senkyunolide I and butylidenephthalide in geoherb samples were higher than those in non-geoherb samples, but the contents of ferulic acid and levistolide A were lower in the geoherb samples. Furthermore, the geoherbs showed better nitric oxide (NO) inhibitory and calcium antagonistic activities than the non-geoherbs. These results demonstrate the diversity in quality of RAS between geoherbs and non-geoherbs.

Constituents Isolated from the Leaves of Glycyrrhiza uralansis and Their Anti-Inflammatory Activities on LPS-Induced RAW264.7 Cells.

Licorice, the root and rhizome of Glycyrrhiza uralansis Fisch, is one of the most frequently used Traditional Chinese Medicines in rigorous clinical trials to remove toxins and sputum, and to relieve coughing. However, the aerial parts are not used so widely at present. It has been reported that the aerial parts have many bioactivities such as anti-microbial and anti-HIV activities. In this study, we aimed to discover the bioactive compounds from the leaves of G. uralensis. Four new compounds, licostilbene A-B (1-2) and licofuranol A-B (3-4), together with eight known flavonoids (5-12), were isolated and identified from the leaves of G. uralensis. Their structures were elucidated mainly by the interpretation of high-resolution electrospray mass spectrometry (HR-ESI-MS) and nuclear magnetic resonance (NMR) spectroscopic data. Compared with quercetin, which showed a 50% inhibitory concentration (IC50) value of 4.08 µg/mL, compounds 1-9 showed significant anti-inflammatory activities by inhibiting lipopolysaccharide (LPS)-induced nitric oxide (NO) production with IC50 values of 2.60, 2.15, 3.21, 3.25, 2.00, 3.45, 2.53, 3.13 and 3.17 µg/mL, respectively. The discovery of these active compounds is important for the prevention and treatment of inflammation.

Prediction of the relationship between the mandibular and craniofacial bone and cervical vertebrae based on a genetic algorithm in patients with skeletal class Ⅱ malocclusion / 口腔疾病防治

Objective@#To explore the correlation between the parameters of the mandible and parameters of cervical vertebrae and craniofacial bone in class Ⅱ skeletal patients in Northeast China and to establish correlation equations expressing the relationship between the mandible and cervical vertebrae and craniofacial bone directly and quantitatively for the clinical diagnosis and treatment of orthodontics and orthognathics and for prediction. @*Methods @#The mandible, cranial facial bone and cervical vertebrae of 201 children and adolescents aged 8 to 20 years were measured using digital cranial lateral tablets. All of the cases were divided into male (n=75) and female (n=126) groups using a sensitivity analysis method based on genetic algorithms to select the craniofacial bone and cervical bone with strong sensitivity to mandible parameters and to establish relevant equations. @*Results @#Through sensitivity analysis, the parameters with the strongest correlation between the measured values of the mandible were H4 and SN, those with a strong correlation were SN-Ar, the anterior and posterior high ratio SGo/NGn, the Y axis angle and mandibular angle Ar-Go-Gn. The established equation was as follows: males: Ar-Pg=28.415+1.818×H4+0.746×SN(r2=0.056 8, P < 0.001); females: Ar-Pg=15.168+1.706×H4+0.675×SN+0.31×SN-Ar-0.29×Y axis angle (r2=0.611, P < 0.001). No significant difference was found between the predicted values obtained by the established equations and measured values (P > 0.05). @*Conclusion @#The mandibular length equation established by sensitivity analysis and genetic algorithms is statistically significant and can predict a certain degree of growth and development.

Selenium suppresses glutamate-induced cell death and prevents mitochondrial morphological dynamic alterations in hippocampal HT22 neuronal cells.

BACKGROUND: Previous studies have indicated that selenium supplementation may be beneficial in neuroprotection against glutamate-induced cell damage, in which mitochondrial dysfunction is considered a major pathogenic feature. However, the exact mechanisms by which selenium protects against glutamate-provoked mitochondrial perturbation remain ambiguous. In this study glutamate exposed murine hippocampal neuronal HT22 cell was used as a model to investigate the underlying mechanisms of selenium-dependent protection against mitochondria damage. RESULTS: We find that glutamate-induced cytotoxicity was associated with enhancement of superoxide production, activation of caspase-9 and -3, increases of mitochondrial fission marker and mitochondrial morphological changes. Selenium significantly resolved the glutamate-induced mitochondria structural damage, alleviated oxidative stress, decreased Apaf-1, caspases-9 and -3 contents, and altered the autophagy process as observed by a decline in the ratio of the autophagy markers LC3-I and LC3-II. CONCLUSION: These findings suggest that the protection of selenium against glutamate stimulated cell damage of HT22 cells is associated with amelioration of mitochondrial dynamic imbalance.

Overexpression of selenoprotein H prevents mitochondrial dynamic imbalance induced by glutamate exposure.

Selenium and selenoproteins play important roles in neuroprotection against glutamate­induced cell damage, in which mitochondrial dysfunction is considered a major pathogenic feature. Recent studies have revealed that mitochondrial fission could activates mitochondrial initiated cell death pathway. The objectives of the study are to determine whether glutamate induced cell death is mediated through mitochondrial initiated cell death pathway and activation of autophagy, and whether overexpression of selenoprotein H can protect cells from glutamate toxicity by preserving mitochondrial morphology and suppressing autophagy. Vector- or human selenoprotein H (SelH)-transfected HT22 cells (V-HT22 and SelH-HT22, respectively) were exposed to glutamate. The results showed that glutamate-induced cytotoxicity was associated with increased ROS production and imbalance in mitochondrial dynamics and autophagy. These alterations were reversed and cellular integrity restored by overexpression of SelH in HT22 cells.

Choleretic Activity of Turmeric and its Active Ingredients.

Turmeric, a rhizome of Curcumin longa L. is widely used as both a spice and an herbal medicine. The traditional use of turmeric in gastroenterology is mainly based on its choleretic activity. The aim of this study is to determine the effects of turmeric on bile flow (BF) and total bile acids (TBAs) excretion in a bile fistula rat model after acute duodenal administration. A significant dose-dependent enhancement in both BF and TBAs was detected after treatment with the turmeric decoctions which suggested the choleretic activity was bile acid-dependent secretion. In order to direct the active group of compounds, aqueous (AE), ethyl acetate (EtOAc), and petroleum ether (PE) extracts were investigated. The EtOAc and PE extracts showing high effects were purified to locate the active ingredients. Three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) and 2 sesquiterpenes (bisacurone B and ar-turmerone) were isolated. It was found Bisacurone B was the most potent choleretic ingredient followed by ar-turmerone, bisdemethoxycurcumin demethoxycurcumin, and then curcumin. The amounts of the active ingredients were quantitatively analyzed by high-performance liquid chromatography. The EtOAc and PE extracts had high sesquiterpenes and curcuminoids content, while the AE extract had poor content of sesquiterpenes and curcuminoids which affected neither BF nor TBAs. Based on the results of multiple linear regression analysis, the content of BIS and TUR were dominant factors (P < 0.01) of controlling BL and TBAs in EtOAC and PE extracts.

Efficient free radical generation against cancer cells by low-dose X-ray irradiation with a functional SPC delivery nanosystem.

Tumor hypoxia is a negative prognostic factor in cancer radiotherapy, due in part to its role in causing resistance to radiotherapy. It has attracted extensive critical attention to radiation sensitizers by using active oxygen to improve radiotherapy outcome. Active oxygen delivery functional materials are promising candidates to transport active oxygen to tumor cells. Herein, we report an oxygen delivery functional material by using hollow mesoporous silica nanoparticles (HMSNs) as carriers, synthesizing sodium percarbonate (SPC) in the channels and cavity of HMSNs (SPC@HMSNs) and coating polyacrylic acid (PAA) on the functional materials (SPC@HMSNs-PAA). SPC@HMSNs-PAA could release more SPC in a simulated tumor acidic microenvironment (pH ∼ 6.5), which can provide oxygen to improve radiotherapy outcome even under low energy X-ray irradiation. The events induce obvious overproduction of reactive oxygen radicals to kill cancer cells with a significant effect. Meanwhile, no obvious cytotoxicity was observed when SPC@HMSNs-PAA applied alone. The radiosensitization of SPC@HMSNs-PAA on cancer cells, even exposure to low-energy X-ray irradiation, may suggest promising application in radiotherapy.

Lysosome-controlled efficient ROS overproduction against cancer cells with a high pH-responsive catalytic nanosystem.

Excess reactive oxygen species (ROS) have been proved to damage cancer cells efficiently. ROS overproduction is thus greatly desirable for cancer therapy. To date, ROS production is generally uncontrollable and outside cells, which always bring severe side-effects in the vasculature. Since most ROS share a very short half-life and primarily react close to their site of formation, it would be more efficient if excess ROS are controllably produced inside cancer cells. Herein, we report an efficient lysosome-controlled ROS overproduction via a pH-responsive catalytic nanosystem (FeOx-MSNs), which catalyze the decomposition of H2O2 to produce considerable ROS selectively inside the acidic lysosomes (pH 5.0) of cancer cells. After a further incorporation of ROS-sensitive TMB into the nanosystem (FeOx-MSNs-TMB), both a distinct cell labeling and an efficient death of breast carcinoma cells are obtained. This lysosome-controlled efficient ROS overproduction suggests promising applications in cancer treatments.

Community-based mental health counseling for children orphaned by AIDS in China.

There is an urgent need to develop scalable approaches to community-based mental health services for children in rural China and other developing countries involving task shifting from clinicians to trained community workers. Evidence is needed about the effectiveness of interventions for children affected by AIDS in rural areas. This article describes an intervention study aimed at developing, implementing, and evaluating a community-based counseling program for the AIDS orphans of Fuyang, Anhui Province, an area of central China where a tainted blood donation scheme infected countless farmers and left many children orphaned by AIDS. In China these children live in rural settings with no access to mental health services. The authors trained a group of community-based counselors to provide group counseling sessions focusing on self-awareness and communication and to provide a basic therapeutic approach for depression and anxiety. The authors conducted a baseline and two follow-up surveys of 39 children who met the clinical diagnostic criteria for anxiety and depression. There was a statistically significant improvement for the children on anxiety, but there was no statistically significant improvement on depression, with greatest gains immediately following the intervention. We demonstrated the feasibility of task shifting for mental health services in this setting.

Formulation and pharmacokinetic evaluation of a paclitaxel nanosuspension for intravenous delivery.

Paclitaxel is a diterpenoid isolated from Taxus brevifolia. It is effective for various cancers, especially ovarian and breast cancer. Due to its aqueous insolubility, it is administered dissolved in ethanol and Cremophor EL (BASF, Ludwigshafen, Germany), which can cause serious allergic reactions. In order to eliminate Cremophor EL, paclitaxel was formulated as a nanosuspension by high-pressure homogenization. The nanosuspension was lyophilized to obtain the dry paclitaxel nanoparticles (average size, 214.4 ± 15.03 nm), which enhanced both the physical and chemical stability of paclitaxel nanoparticles. Paclitaxel dissolution was also enhanced by the nanosuspension. Differential scanning calorimetry showed that the crystallinity of paclitaxel was preserved during the high-pressure homogenization process. The pharmacokinetics and tissue distribution of paclitaxel were compared after intravenous administration of paclitaxel nanosuspension and paclitaxel injection. In rat plasma, paclitaxel nanosuspension exhibited a significantly (P < 0.01) reduced area under the concentration curve (AUC)(0-∞) (20.343 ± 9.119 µg · h · mL(-1) vs 5.196 ± 1.426 µg · h · mL(-1)), greater clearance (2.050 ± 0.616 L · kg(-1) · h(-1) vs 0.556 ± 0.190 L · kg(-1) · h(-1)), and shorter elimination half-life (5.646 ± 2.941 vs 3.774 ± 1.352 hours) compared with the paclitaxel solution. In contrast, the paclitaxel nanosuspension resulted in a significantly greater AUC(0-∞) in liver, lung, and spleen (all P < 0.01), but not in heart or kidney.

Alkaloid and sesquiterpenes from the root tuber of Curcuma longa.

One new quinoline alkaloid and seven known bisabolane sesquiterpenes: 2-(2'-methyl-1'-propenyl)-4, 6-dimethyl-7-hydroxyquinoline (1), 2, 5-dihydroxybisabola-3, 10-diene (2), 4, 5-dihydroxybisabola-2,10-diene (3), turmeronol A (4), bisacurone (5), bisacurone A (6), bisacurone B (7) , bisacurone C (8), as well as dehydrozingerone (9) and zingerone (10) were isolated from the root tuber of Curcuma longa. Their structures were identified by spectral evidence. Compound 1 is a new compound, compounds 6 -8 were isolated from this plant for the first time and compounds 9 - 10 from Curcuma for the first time.