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Polymer carbon dot membranes prepared through bioinspired complexation for robust structure and high proton conductivity.

Polyester thin film composite (PE-TFC) membranes featuring excellent chlorine-resistant property hold grand promise in seawater desalination and wastewater treatment. However, the low reactivity of alcohol or phenolic hydroxyl groups with acyl chloride groups usually leads to the formation of a relatively loose PE network, resulting in undesirable salt rejection. Preparing high-performance PE-TFC membranes remains a daunting challenge. In this study, we propose a thermal-facilitated interfacial polymerization (TFIP) approach to fabricate PE-TFC membranes with high desalination performance. The elevated temperature promoted the diffusion of glucose monomers across the water/heptane interface and then facilitated the reaction rate between glucose and TMC during interfacial polymerization (IP), resulting in the formation of PE layer with a higher cross-linking density compared to that fabricated via conventional IP. The PE membrane prepared via TFIP exhibited a superior ion rejection of 99.5% for Na2SO4 and high water permeance up to 16.1 L m−2 h−1 bar−1, outperforming all the polyester membranes with similar rejection in literature. The resultant PE-TFC membrane displayed unprecedented chlorine resistance (960 000 ppm h) and maintained separation efficiency after exposed to sodium hypochlorite solution (1000 ppm) for 36 days. Polyols including sucrose, raffinose and β-CD were also utilized as monomers, confirming the universality of the TFIP approach for facile preparation of high-performance desalination membranes.

Covalent organic frameworks (COFs) are an emergent class of crystalline porous polymers featuring a long-range regular pore structure, high porosity and excellent chemical stability. Bilayer COF membranes with tunable interfaces hold great promise in ionic and molecular separations. Herein, we designed a series of bilayer COF membranes with homointerface and heterointerface, which achieved efficient desalination performance through manipulating the interface confinement effect. COF membranes were prepared on a porous support through successively regulating the growth of imine-based 2D COF layers by in situ growth and counter-diffusion approach at ambient temperature. Narrowed sub-nanometer interlaced channels were created at the interface of the two adjacent COF layers. The rejection rate of homointerface COF membrane toward Na2SO4 was higher than that of heterointerface COF membranes, which was due to the synergistic enhancement of interface-confined size sieving and Donnan effect. The homointerface TpPa–SO3H/TpPa–SO3H/MPAN membrane exhibits a rejection rate of 98.3% for Na2SO4 and water flux of 13.1 L m−2 h−1 bar−1, which is the highest performance among COF desalination membranes ever reported.

Graphene oxide (GO) has drawn extensive research interest in the fabrication of high-performance membranes. However, the original narrow interlayer distance of the GO membrane restrains the permeat...

No study has examined myocardial work in subjects with cancer therapy-related cardiac dysfunction (CTRCD). Myocardial work, as a new ultrasonic indicator, reflects the metabolism and oxygen consumption of the left ventricle. The aim of this study was to test the relative value of new indices of myocardial work and global longitudinal strain (GLS) in detecting changes in myocardial function during the treatment of breast cancer by two-dimensional and three-dimensional echocardiography. We enrolled 79 breast cancer patients undergoing different tumor treatment regimens. Follow-up observation was conducted before and after chemotherapy. The effects of breast cancer chemotherapy and targeted therapy on the development of CTRCD [defined as an absolute reduction in left ventricular ejection fraction (LVEF) of >5% to p < 0.05). The three-dimensional strain changes after T6 and T8 had no advantages compared with GLS. Body mass index (BMI), the GLS change rate after the second cycle of chemotherapy (G2v) and the 3D-GCS change rate after the second cycle of chemotherapy (C2v) were independent factors that could predict the occurrence of CTRCD during follow-up, among which BMI was the best predictor (area under the curve, 0.922). In conclusion, the current study determined that GLS was superior to GWI in predicting cardiac function in patients with tumors with little variation in blood pressure. BMI, G2v and C2v can be used to predict the occurrence of CTRCD.

Ionic covalent organic framework membranes (iCOFMs) hold great promise in ion conduction-relevant applications because the high content and monodispersed ionic groups could afford superior ion conduction. The key to push the upper limit of ion conductivity is to maximize the ion exchange capacity (IEC). Here, we explore iCOFMs with a superhigh ion exchange capacity of 4.6 mmol g−1, using a dual-activation interfacial polymerization strategy. Fukui function is employed as a descriptor of monomer reactivity. We use Brønsted acid to activate aldehyde monomers in organic phase and Brønsted base to activate ionic amine monomers in water phase. After the dual-activation, the reaction between aldehyde monomer and amine monomer at the water-organic interface is significantly accelerated, leading to iCOFMs with high crystallinity. The resultant iCOFMs display a prominent proton conductivity up to 0.66 S cm−1, holding great promise in ion transport and ionic separation applications.

Recently, the overall survival (OS) and progression-free survival (PFS) of patients with advanced cancer has been significantly improved due to the application of immune checkpoint inhibitors (ICIs). Low response rate and high occurrence of immune-related adverse events (irAEs) make urgently need for ideal predictive biomarkers to identity efficient population and guide treatment strategies. Cytokines are small soluble proteins with a wide range of biological activity that are secreted by activated immune cells or tumor cells and act as a bridge between innate immunity, infection, inflammation and cancer. Cytokines can be detected in peripheral blood and suitable for dynamic detection. During the era of ICIs, many studies investigated the role of cytokines in prediction of the efficiency and toxicity of ICIs. Herein, we review the relevant studies on TNF-α, IFN-γ, IL-6, IL-8, TGF-β and other cytokines as biomarkers for predicting ICI-related reactions and adverse events, and explore the immunomodulatory mechanisms. Finally, the most important purpose of this review is to help identify predictors of ICI to screen patients who are most likely to benefit from immunotherapy.

Determining the etiology of end-stage renal disease (ESRD) constitutes a great challenge in the context of renal transplantation. Evidence is lacking on the genetic findings for adult renal transplant recipients through exome sequencing (ES). Adult patients on kidney transplant waitlist were recruited from 2017 to 2019. Trio-ES was conducted for the families who had multiple affected individuals with nephropathy or clinical suspicion of a genetic kidney disease owing to early onset or extrarenal features. Pathogenic variants were confirmed in 62 from 115 families post sequencing for 421 individuals including 195 health family members as potential living donors. Seventeen distinct genetic disorders were identified confirming the priori diagnosis in 33 (28.7%) families, modified or reclassified the clinical diagnosis in 27 (23.5%) families, and established a diagnosis in two families with ESRD of unknown etiology. In 14.8% of the families, we detected promising variants of uncertain significance in candidate genes associated with renal development or renal disease. Furthermore, we reported the secondary findings of oncogenes in 4.4% of the patients and known single-nucleotide polymorphisms associated with pharmacokinetics in our cohort to predict the drug levels of tacrolimus and mycophenolate. The diagnostic utility of the genetic findings has provided new clinical insight in most families that help with preplanned renal transplantation.

Covalent organic framework (COF) membranes hold potential for widespread applicability, but scalable fabrication is challenging. Here, we demonstrate the disorder-to-order transformation from amorphous polymeric membrane to crystalline COF membrane via monomer exchange. Solution processing is used to prepare amorphous membrane and the replacing monomer is selected based on the chemical and thermodynamical stability of the final framework. Reversible imine bonds allow the extraneous monomers to replace the pristine monomers within amorphous membrane, driving the transformation from disordered network to ordered framework. Incorporation of intramolecular hydrogen bonds enables the crystalline COF to imprint the amorphous membrane morphology. The COF membranes harvest proton conductivity up to 0.53 S cm-1 at 80 °C. Our strategy bridges amorphous polymeric and crystalline COF membranes for large-scale fabrication of COF membranes and affords guidance on materials processing.

Mixed matrix membranes (MMMs), which are fabricated by incorporating dispersed fillers into a continuous polymeric matrix, have been broadly utilized in gas separation due to their unique hierarchical structures and enhanced separation performance. Fillers of intrinsic nanopores (FINs) have drawn considerable attention because they not only can provide additional molecular transport channels but also have a potential size-sieving property. Although many excellent reviews about MMMs have been published, quite few of them are specifically designed for MMMs containing FINs. This Review focuses on three kinds of FINs, covalent organic frameworks (COFs), zeolites, and metal–organic frameworks (MOFs), as the representatives of organic, inorganic, and inorganic–organic FINs. The typical physical and chemical features of these three kinds of FINs are introduced. Afterward, methods to prepare FIN-based MMMs are briefly introduced. Particularly, solutions to prevent the aggregation and improve the dispersion of FIN...

Graphene oxide (GO), an emergent 2D nanomaterial, holds great promise in fabricating membranes with high permeability and precise sieving ability endowed by the tunable interlayer distance. Currently, the available interlayer distance is usually less than 2 nm. In this study, a GO-based membrane with an interlayer distance greater than 40 nm is synthesised: a kind of 2D/2D nanoheterojunction of vertically grown covalent organic framework (COF) nanosheets on GO nanosheets (v-COF@GO) is constructed and then intercalated into adjacent GO nanosheets via a vacuum-assisted self-assembly process. By tuning the size of COF nanosheets, the interlayer distance increases from 0.81 nm of the GO membrane to 42.2 nm of the GO/v-COF@GO membrane, and accordingly, the permeate flux of the GO/v-COF@GO membrane exhibits a 157-fold increase. Meanwhile, the resulting membranes acquire superior morphological stability as indicated by the fact that the permeate flux is linearly proportional to the transmembrane pressure in the range of 0–0.5 bar and the appearance of the membrane remains almost unchanged when immersed in water for two months. This study may offer a facile, generic approach to creating an ultra-large interlayer distance for GO-based membranes and many other kinds of membranes from the assembly of two-dimensional nanomaterials.

Metal-organic frameworks (MOFs) have attracted extensive attention in catalysis and adsorption fields due to the large surface area and tunable pore structure, however MOFs have not been so broadly exploited for water treatment primarily due to their low water stability and hydrophilicity. In this study, a kind of MOFs, poly(acrylic acid) (PAA) modified UiO-66-NH2 (UiO-66-NH2@PAA), was first synthesized and used to fabricate membranes via vacuum-assisted self-assembly process. Owing to the high water adsorption ability of MOF, abundant hydrophilic, negatively-charged carboxyl groups and high surface roughness, the membranes exhibited high hydrophilicity and underwater superoleophobicity, and thus better antifouling performance. Owing to the ionization and deionization ability of carboxyl groups, the membranes exhibited good stability in the pH range from 1 to 11. Owing to the existence of chemical and hydrogen bond interactions, the membranes exhibited improved multicycle stability. Accordingly, the MOF membranes exhibited high separation efficiency for oil/water emulsion (rejection > 99.9%). Under optimum conditions, the pure water flux was 2330 L m−2 h−1 bar−1 and the flux recovery ratio (FRR) after 3 cycles separation of oil/water emulsion maintained over 80%, manifesting great potential of MOF membranes in oil/water separation.

Background Treacher Collins syndrome‐1 (TCS1; OMIM# 154500) is a rare autosomal dominant disease that is defined by congenital craniofacial dysplasia. Here, we report four sporadic and one familial case of TCS1 in Chinese patients with clinical features presenting as hypoplasia of the zygomatic complex and mandible, downslanting palpebral fissures, coloboma of the lower eyelids, and conductive hearing loss. Materials and Methods Audiological, radiological, and physical examinations were performed. Targeted next‐generation sequencing (NGS) was performed to examine the genetics of this disease in five probands, and Sanger sequencing was used to confirm the identified variants. A literature review discusses the pathogenesis, treatment, and prevention of TCS1. Results We identified a novel insertion of c.939_940insA (p.Gly314Argfs*35; NM_001135243.1), a novel deletion of c.1766delC (p.Pro589Leufs*7), two previously reported insertions of c.1999_2000insC (p.Arg667Profs*31) and c.4218_4219insG (p.Ser1407Valfs*23), and one previously reported deletion of c.4369_4373delAAGAA (p.Lys1457Glufs*12) in the TCOF1 gene. All five cases exhibited a degree of interfamilial and intrafamilial phenotypic variability. A review of the literature revealed no clear evidence of a genotype–phenotype correlation in TCS1. Conclusion Our results expand the variant spectrum of TCOF1 and highlight that NGS is essential for the diagnosis of TCS and that genetic counseling is beneficial for guiding prevention., Treacher Collins syndrome‐1 (TCS1; OMIM# 154500) is a rare autosomal dominant disease that is defined by congenital craniofacial dysplasia. Here, we report four sporadic and one familial case of TCS1 in Chinese patients with clinical features presenting as hypoplasia of the zygomatic complex and mandible, downslanting palpebral fissures, coloboma of the lower eyelids, and conductive hearing loss. We identified a novel insertion of c.939_940insA (p.Gly314Argfs*35; NM_001135243.1), a novel deletion of c.1766delC (p.Pro589Leufs*7), two previously reported insertions of c.1999_2000insC (p.Arg667Profs*31) and c.4218_4219insG (p.Ser1407Valfs*23), and one previously reported deletion of c.4369_4373delAAGAA (p.Lys1457Glufs*12) in the TCOF1 gene.

Isothermal compressibility, κ T , and isobaric thermal expansivity, α P , can describe the volumetric behavior of a given fluid in response to the change in pressure and temperature, respectively. They are two important parameters that are used in the simulation and modeling of many petroleum and chemical processes. Isothermal compressibility and isobaric thermal expansivity can be calculated with empirical correlations or thermodynamic models, but these methods are not sufficiently accurate. Cubic equations of state (CEOSs) are widely used in the petroleum and chemical industry to describe the phase behavior of fluid mixtures. It is recognized that one of the deficiencies of CEOSs is their inaccuracy in predicting liquid-phase volumes. The volume translation (VT) strategy was proposed to overcome this deficiency, which could significantly improve the performance of CEOSs in predicting volumetric properties. With recent development in the volume-translated equations of state (VT-EOSs), κ T and α P could be predicted more accurately by VT-EOSs. However, the prediction accuracy of κ T and α P by different VT-EOSs has not been comprehensively investigated. In this work, κ T and α P of two pure example fluids (CH4 and CO2) are predicted by seven different VT models: one constant VT model, two linear temperature-dependent VT models, two exponential temperature-dependent VT models, and two temperature-pressure-dependent VT models. The accuracy of each model is evaluated by comparing the predictions with the NIST pseudo-experimental data for the liquid phase, the vapor phase, and the supercritical phase. The predicted results show that the distance-function-based temperature-pressure-dependent VT models exhibit relatively better performance in predicting κ T and α P than the temperature-dependent and the constant VT models. This is because the distance function is a function of both temperature and pressure, which allows the distance-function-based VTs to provide more accurate volume corrections for most of the phase regions and thus can lead to better accuracy in predicting κ T and α P . According to the overall prediction accuracy, the VT-PR EOS model proposed by Abudour et al. (2012) provides the most accurate predictions of κ T , while the VT-SRK EOS model proposed by Chen and Li (2020) provides the most accurate predictions of α P . The findings of this study can help to predict κ T and α P of pure substances at different temperature and pressure conditions by using the most accurate VT-EOS and provide insights for further improvement of volume translation strategies.

Anthracycline drugs are considered to be pivotal drugs in numerous chemotherapy regimens for breast cancer. However, the cardiotoxicity associated with the treatment is an important issue to be addressed. With the emergence of increasingly diverse antitumor drugs, anthracycline-free therapies are able to reduce the cardiotoxicity caused by anthracycline drugs while ensuring that a therapeutic effect is achieved. In the present review, anthracycline-free oncological therapy regimens for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer and the associated cardiovascular toxicity are discussed, as well as some monitoring strategies. It is recommended that patients with HER2-positive breast cancer patients should receive adjuvant chemotherapy with single or dual-targeted therapy, with or without endocrine therapy according to the hormone receptor status determined by immunohistochemical examination. The main side effects of targeted therapy include cardiac dysfunction, hypertension and arrhythmia. According to individual risk stratification, it is recommended that patients should be periodically monitored using echocardiography, electrocardiography and serum markers, to enable the timely detection of the cardiovascular adverse reactions associated with tumor treatment, thereby preventing the morbidity and mortality caused by the cardiotoxicity of these drugs.

Owing to highly porous and low density attributes, aerogels have been actively utilized in catalysis and adsorption processes, but their great potential in filtration requires exploitation. In this study, an asymmetric aerogel membrane is fabricated via one-pot hydrothermal reaction-induced self-cross-linking of poly(vinyl alcohol) (PVA), which exhibits ultrafast permeation for the separation of oil-in-water emulsion. Meanwhile, carbon nanotubes are added to improve the mechanical strength of the aerogel membranes. The self-cross-linking of PVA forms the supporting layer, and the exchange of water and vapor at the interface of PVA solution and air generates the separating layer as well as abundant hydroxyl groups on the membrane surface. The density, porosity, pore size, and wettability of the aerogel membrane can be tuned by the PVA concentration. Owing to high porosity (>95%) and suitable pore size (

Membranes with excellent antifouling properties and persistent high permeance are eternal pursuits in membrane technology. Herein, we proposed an electrostatic enhanced surface segregation approach toward the antifouling and self-cleaning membranes for molecular separation. A copolymer containing quaternary ammonium (QA) segments was designed as the surface segregation agent in the casting solution, while polysulphonic acid (PSA) was designed as the crosslinking agent in the coagulation bath. Driven by the electrostatic interactions between the positively charged QA and negatively charged sulphonic groups, the copolymer and PSA were in-situ assembled during the non-solvent induced phase separation (NIPS) processes, generating a selective separation layer on the polymeric matrix. The segregation of copolymer was enhanced, leading to a high surface coverage of ionic QA and sulphonic groups and a significantly improved surface hydrophilicity. Accordingly, the membrane exhibited a high water permeance up to 124 Lm−2h−1bar−1 with dye rejection over 95%. Moreover, the membrane exhibited excellent antifouling performance with the ultralow total permeance decline of 1.2% and the ultrahigh permeance recovery ratio of 99.8% against emulsified oil, as well as the self-cleaning property against crude oil. Hopefully, this study can afford a novel and generic approach to antifouling and self-cleaning membranes for diverse separations.

Graphene oxide (GO) membranes hold great promise in molecular separation owing to the ultrathin thickness as well as precisely controllable interlayer distance. However, the tortuous mass transport pathway along stacked nanosheets hinders the availability of high-flux GO membranes. Herein, we design multi-pathway GO membranes to afford fast water transport through in-plane and interlayer pathways. The in-plane pathway is introduced by the porous GO (pGO) nanosheets and the interlayer pathway is enlarged by intercalating hydrophilic halloysite nanotubes (HNTs) into adjacent pGO nanosheets, jointly contributing to the enhanced water permeance. Through manipulating the intercalator amount, the optimized membrane displays ultrahigh water permeance of 206.7 L m−2 h−1 bar−1 and dye rejections over 98.5%. Furthermore, the resultant membranes exhibit resistance against broad-spectrum oil-in-water emulsions. Our study can pave a facile and prospective way to fabricating high-performance two-dimensional laminated membranes.

A facile approach to fabricating the antifouling, high-flux oil/water separation carbon nanotube (CNT) nanohybrid membranes was explored by polymer-mediated surface charging and hydrophilization through vacuum-assisted self-assembly process. The controlled stacking of CNT imparted the membranes hierarchical nanostructure and high water permeation reaching 4592 L m −2 h −1 bar −1 , which was about 10 folds of commercial ultrafiltration membranes used for oil/water separation. Modifying CNT with a series of polymers endowed the membranes with different surface charge and hydrophilicity. The compact hydration layer was formed at the interface of water/membrane by the water trapped in the hierarchical nanostructure to prevent oil from adhering on the membrane surface. Hence, the polymer@CNT nanohybrid membranes possessed underwater superoleophobicity and low oil adhesive force. Moreover, the antifouling properties of as-prepared membranes were evaluated through filtration of oil-in-water emulsions with different surface charges and the results demonstrated that synergetically regulating the surface charge and hydrophilicity could tune the interactions between the foulants and membrane surface, which can efficiently inhibit the irreversible fouling, leading to 100% flux recovery ratio (FRR). The fabrication process of the polymer@CNT nanohybrid membranes with high water permeation, high separation efficiency and excellent antifouling properties may enlighten the great prospects for CNT-based materials in water separation and purification.

Membrane fouling is one of the main bottlenecks in membrane separation processes for water purification. Due to the complexity of foulants, engineering the membrane surface to coordinate multi-defense mechanisms is essential for fabricating membranes with broad-spectrum antifouling performance. In this study, we synthesized a heterostructured modifier comprising zwitterionic, fluorine-containing polymeric segments and inorganic silver nanoparticles. The heterostructured modifiers were synergistically segregated to the membrane surface during non-solvent induced phase separation. A dual-heterogeneous surface structure was formed, compromising physicochemical heterogeneity with hydrophilic-low surface energy-antibacterial domains, as well as topological heterogeneity with nanopapillae. Consequently, multi-defense mechanisms including passive fouling resistance, fouling release and active antibacterial mechanisms were integrated to the membrane surface, leading to superior antifouling performances against oil-in-water emulsions with ultralow total flux decline ratio of 3.3% and the flux recovery ratio of nearly 100%, as well as nearly 100% antibacterial activity against E. Coli with an obvious inhibition zone.

For water treatment applications, fabricating a high permeation flux membrane with super-strong mechanical strength and excellent long-term antifouling properties remains a great challenge. In this study, robust, antifouling carbon nanotube (CNT) nanohybrid membranes have been fabricated for oil/water separation. Polyethyleneimine (PEI) with abundant amino groups and a hyperbranched structure is utilized to construct a nanocoating on a CNT surface to enhance their hydrophilicity through multiple interactions between PEI and CNTs. Secondly, the vacuum-assisted self-assembly method is utilized to fabricate free-standing membranes by filtration of CNT dispersions. Finally, trimesoyl chloride (TMC) is utilized to post-modify membranes to enhance the mechanical strength and hydrophilicity and change the surface charge through reaction between amino groups and acyl chloride groups as well as hydrolysis of acyl chloride groups into carboxyl groups. The controlled stacking of CNTs renders membranes with a hierarchical nanostructure and a high porosity, leading to high water flux. The physical and chemical crosslinking renders membranes with high mechanical strength, as measured by atomic force microscopy (AFM) and tensile strength tests. The high hydrophilicity and negatively charged surface render membranes with good antifouling properties, as evaluated by filtration experiments of various oil-in-water emulsions. This study may reveal the great prospects of CNT-based membranes with superior comprehensive properties in water treatment relevant applications.

Nanofiltration membranes featuring excellent separation and antifouling performances are highly desired for applications such as water purification. In this study, inspired by the phenomenon of coordination-driven self-assembly and the structures of aquaporins in nature, an arginine (Arg)-FeIII complex was designed and incorporated into the polyamide layer during interfacial polymerization, endowing the resultant nanofiltration membranes with enhanced water permeance and prominent antifouling performance. Owing to the active amine groups, the Arg-FeIII complex could react with trimesoyl chloride (TMC) and thus act as the aqueous additive in company with piperazine (PIP), which improved the compatibility between the organic phase and aqueous phase. The interfacial channels between the Arg-FeIII complex and the polyamide matrix as well as the hydrogen bonds interaction between water and the Arg-FeIII complex facilitated the rapid water transfer. When the content of the Arg-FeIII complex reached 0.3 g/L, the water permeance was elevated significantly, twice than that of the pristine polyamide membrane. Meanwhile, the rejections for Na2SO4 and dyes were close to those of the pristine polyamide membrane. Furthermore, the resultant membranes displayed exceptional antifouling performance. Introducing the metal-organic complex into the interfacial polymerization process proves an effective and promising attempt to fabricate membranes with high performance for water resource reclamation.

RpoS (σ(S)), the stationary phase/stress σ factor, controls the expression of a large number of genes involved in cellular responses to a variety of stresses. However, the role of RpoS appears to differ in different bacteria. While RpoS is an important regulator of flagellum biosynthesis, it is associated with biofilm development in Edwardsiella tarda. Biofilms are dense communities formed by bacteria and are important for microbe survival under unfavorable conditions. The type VI secretion system (T6SS) discovered recently is reportedly associated with several phenotypes, ranging from biofilm formation to stress sensing. For example, Vibrio anguillarum T6SS was proposed to serve as a sensor for extracytoplasmic signals and modulates RpoS expression and stress response. In this study, we investigated the physiological roles of RpoS in Yersinia pseudotuberculosis, including bacterial survival under stress conditions, flagella formation, biofilm development and T6SS expression. We found that RpoS is important in resistance to multiple stressors-including H2O2, acid, osmotic and heat shock-in Y. pseudotuberculosis. In addition, our study showed that RpoS not only modulates the expression of T6SS but also regulates flagellum formation by positively controlling the flagellar master regulatory gene flhDC, and affects the formation of biofilm on Caenorhabditis elegans by regulating the synthesis of exopolysaccharides. Taken together, these results show that RpoS plays a central role in cell fitness under several adverse conditions in Y. pseudotuberculosis.

This study focuses on the genetic and biochemical characterization of phenol hydroxylase (Phe, NCgl2588) from Corynebacterium glutamicum that shares 31% identity in amino acids with phenol hydroxylase from yeast Trichosporon cutaneum but less similarity with that from bacteria. The phe deletion mutant significantly reduced its ability to grow with phenol as the sole carbon and energy source. Expression of the phe gene was strongly induced with phenol and also subject to the control of carbon catabolite repression (CCR). The molecular weight of purified Phe protein determined by gel filtration chromatography was 70 kDa, indicating that Phe exists as a monomer in the purification condition. However, Phe protein pre-incubated with phenol showed a molecular weight of 140 kDa, suggesting that Phe is likely active as a dimer. In addition to phenol, the Phe protein could utilize various other phenolic compounds as substrates. Site-directed mutagenesis revealed that D75, P261, R262, R269, C349 and C476 are key amino acid residues closely related to the enzyme activity of Phe.

To determine bacteriostatic abilities of Artemisia argyi extracts, and to explore the effect of Artemisia argyi extracts on oral ulcer in rats. Methods: We extracted the mixture of Artemisia argyi volatile oils and water-extraction by leaching method and evaluated the anti-microbial effect of Artemisia argyi extracts on common oral floras in vitro. The rat cheeks were burnt by NaOH to establish the models of oral ulcer. The curative effects of crude drug of Artemisia argyi extracts at 2.0, 1.0, 0.5 g/mL on oral ulcer in rats were evaluated by measuring the oral ulcer healing time. Serum TNF-α level and expression of proliferating cell nuclear antigen (PCNA) were analyzed by ELASA and immunohistochemical staining. Results: Artemisia argyi extracts obviously inhibited the Staphylococcus aureus and Streptococcus. NaOH-made oral ulcer in rats were successfully established. The crude drug at 2.0 and 1.0 g/mL obviously reduced healing time, significantly inhibited the release of TNF-α, and improved the PCNA level in the ulcer tissues (All P0.01). The extracts obviously reduced the local inflammatory reaction and promoted tissue repair of oral ulcer. Conclusion: Artemisia argyi extracts promote tissue repair of oral ulcer via inhibiting bacterial growth, reducing the release of TNF-α and improving the PCNA level.目的：体外研究艾叶提取物抑菌能力，初步探索艾叶提取物对大鼠口腔溃疡模型的治疗效果及其机制。方法：用浸出法提取艾叶挥发油及水提液混合物；体外研究艾叶提取物对口腔常见菌群的抑菌能力；以NaOH灼烧大鼠唇内侧造口腔溃疡模型，观察2.0，1.0，0.5 g/mL生药浓度的艾叶提取物对大鼠口腔溃疡模型愈合时间、溃疡修复程度的影响；运用ELASA法检测各组血清肿瘤坏死因子(tumor necrosis factor-α，TNF-α)含量，免疫组织化学法检测溃疡局部病变组织增殖细胞核抗原(proliferating cell nuclear antigen，PCNA)的表达情况。结果：艾叶提取物对金黄色葡萄球菌和链球菌生长具有显著的抑制作用；使用NaOH晶体成功构建大鼠口腔溃疡模型，2.0和1.0g/mL艾叶提取物均可有效缩短口腔溃疡愈合时间(P0.01)，显著降低血清TNF-α表达(P0.01)及提高溃疡局部PCNA表达水平(P0.01)，有效减轻局部炎症反应并促进组织修复。结论：艾叶提取物能通过抑制细菌生长，降低血清TNF-α含量及提高溃疡局部PCNA表达来促进大鼠口腔溃疡的愈合。.

This study focuses on the genetic and biochemical characterization of phenol hydroxylase (Phe, NCgl2588) from Corynebacterium glutamicum that shares 31% identity in amino acids with phenol hydroxylase from yeast Trichosporon cutaneum but less similarity with that from bacteria. The phe deletion mutant significantly reduced its ability to grow with phenol as the sole carbon and energy source. Expression of the phe gene was strongly induced with phenol and also subject to the control of carbon catabolite repression (CCR). The molecular weight of purified Phe protein determined by gel filtration chromatography was 70 kDa, indicating that Phe exists as a monomer in the purification condition. However, Phe protein pre-incubated with phenol showed a molecular weight of 140 kDa, suggesting that Phe is likely active as a dimer. In addition to phenol, the Phe protein could utilize various other phenolic compounds as substrates. Site-directed mutagenesis revealed that D75, P261, R262, R269, C349 and C476 are key amino acid residues closely related to the enzyme activity of Phe.

Ohr, a bacterial protein encoded by the Organic Hydroperoxide Resistance (ohr) gene, plays a critical role in resistance to organic hydroperoxides. In the present study, we show that the Cys-based thiol-dependent Ohr of Corynebacterium glutamicum decomposes organic hydroperoxides more efficiently than hydrogen peroxide. Replacement of either of the two Cys residues of Ohr by a Ser residue resulted in drastic loss of activity. The electron donors supporting regeneration of the peroxidase activity of the oxidized Ohr of C. glutamicum were principally lipoylated proteins (LpdA and Lpd/SucB). A Δohr mutant exhibited significantly decreased resistance to organic hydroperoxides and marked accumulation of reactive oxygen species (ROS) in vivo; protein carbonylation was also enhanced notably. The resistance to hydrogen peroxide also decreased, but protein carbonylation did not rise to any great extent. Together, the results unequivocally show that Ohr is essential for mediation of organic hydroperoxide resistance by C. glutamicum.