Diosmetin-7-O-ß-D-glucopyranoside from Pogostemonis Herba alleviated SARS-CoV-2-induced pneumonia by reshaping macrophage polarization and limiting viral replication.

ETHNOPHARMACOLOGICAL RELEVANCE: Viral pneumonia is the leading cause of death after SARS-CoV-2 infection. Despite effective at early stage, long-term treatment with glucocorticoids can lead to a variety of adverse effects and limited benefits. The Chinese traditional herb Pogostemonis Herba is the aerial part of Pogostemon Cablin (Blanco) Benth., which has potent antiviral, antibacterial, anti-inflammatory, and anticancer effects. It was used widely for treating various throat and respiratory diseases, including COVID-19, viral infection, cough, allergic asthma, acute lung injury and lung cancer. AIM OF THE STUDY: To investigate the antiviral and anti-inflammatory effects of chemical compounds from Pogostemonis Herba in SARS-CoV-2-infected hACE2-overexpressing mouse macrophage RAW264.7 cells and hACE2 transgenic mice. MATERIALS AND METHODS: The hACE2-overexpressing RAW264.7 cells were exposed with SARS-CoV-2. The cell viability was detected by CCK8 assay and cell apoptotic rate was by flow cytometric assay. The expressions of macrophage M1 phenotype markers (TNF-α and IL-6) and M2 markers (IL-10 and Arg-1) as well as the viral loads were detected by qPCR. The mice were inoculated intranasally with SARS-CoV-2 omicron variant to induce viral pneumonia. The levels of macrophages, neutrophils, and T cells in the lung tissues of infected mice were analyzed by full spectrum flow cytometry. The expressions of key proteins were detected by Western blot assay. RESULTS: Diosmetin-7-O-ß-D-glucopyranoside (DG) presented the strongest anti-SARS-CoV-2 activity. Intervention with DG at the concentrations of 0.625-2.5 µM not only reduced the viral replication, cell apoptosis, and the productions of inflammatory cytokines (IL-6 and TNF-α) in SARS-CoV-2-infected RAW264.7 cells, but also reversed macrophage polarity from M1 to M2 phenotype. Furthermore, treatment with DG (25-100 mg/kg) alleviated acute lung injury, and reduced macrophage infiltration in SARS-COV-2-infected mice. Mechanistically, DG inhibited SARS-COV-2 gene expression and HK3 translation via targeting YTHDF1, resulting in the inactivation of glycolysis-mediated NF-κB pathway. CONCLUSIONS: DG exerted the potent antiviral and anti-inflammatory activities. It reduced pneumonia in SARS-COV-2-infected mice via inhibiting the viral replication and accelerating M2 macrophage polarization via targeting YTHDF1, indicating its potential for COVID-19 treatment.

A reversible photochromic covalent organic framework.

Covalent organic frameworks are a type of crystalline porous materials that linked through covalent bond, and they have numerous potential applications in adsorption, separation, catalysis, and more. However, there are rarely relevant reported on photochromism. Fortunately, a hydrazone-linked DBTB-DETH-COF is rapidly generated through ultrasound method. The DBTB-DETH-COF is found to exhibit reversible photochromism (at least 50 cycles) from yellow to olive in the presence of light and air, and subsequently back to the original color upon heating. In addition, the structure of DBTB-DETH-COF remains unchanged after 15 days of light illumination. Furthermore, the reason of photochromic process is discussed by electron paramagnetic resonance, X-ray photoelectron spectroscopy, electrochemistry characterizations and transient absorption measurements. The reversible photochromic DBTB-DETH-COF can be used as anti-counterfeiting ink and optical switch in the presence of air. This work expands a stable organic photochromic material and broadens the applications of COFs.

N-terminus GTPase domain of the cytoskeleton protein FtsZ plays a critical role in its adaptation to high hydrostatic pressure.

Studies in model microorganisms showed that cell division is highly vulnerable to high hydrostatic pressure (HHP). Disassembly of FtsZ filaments induced by HHP results in the failure of cell division and formation of filamentous cells in E. coli. The specific characteristics of FtsZ that allow for functional cell division in the deep-sea environments, especially in obligate piezophiles that grow exclusively under HHP condition, remain enigmatic. In this study, by using a self-developed HHP in-situ fixation apparatus, we investigated the effect of HHP on FtsZ by examining the subcellular localization of GFP-tagged FtsZ in vivo and the stability of FtsZ filament in vitro. We compared the pressure tolerance of FtsZ proteins from pressure-sensitive strain Shewanella oneidensis MR-1 (FtsZSo) and obligately piezophilic strain Shewanella benthica DB21MT-2 (FtsZSb). Our findings showed that, unlike FtsZSo, HHP hardly affected the Z-ring formation of FtsZSb, and filaments composed of FtsZSb were more stable after incubation under 50 MPa. By constructing chimeric and single amino acid mutated FtsZ proteins, we identified five residues in the N-terminal GTPase domain of FtsZSb whose mutation would impair the Z-ring formation under HHP conditions. Overall, these results demonstrate that FtsZ from the obligately piezophilic strain exhibits superior pressure tolerance than its homologue from shallow water species, both in vivo and in vitro. Differences in pressure tolerance of FtsZ are largely attributed to the N-terminal GTPase domain. This represents the first in-depth study of the adaptation of microbial cytoskeleton protein FtsZ to high hydrostatic pressure, which may provide insights into understanding the complex bioprocess of cell division under extreme environments.

Assessment of left ventricular myocardial systolic dysfunction in premature ovarian insufficiency patients using echocardiographic layer-specific myocardial strain imaging.

BACKGROUND: Due to the lack of oestrogen, premature ovarian insufficiency (POI) is an independent risk factor for ischaemic heart disease and overall cardiovascular disease. This study aimed to apply layer-specific myocardial strain for early quantitative evaluation of subclinical left ventricular myocardial systolic function changes in patients with POI. METHODS: Forty-eight newly diagnosed, untreated patients with POI (POI group) and fifty healthy female subjects matched for age, height and weight (control group) were enrolled. Standard transthoracic echocardiography was used to measure conventional parameters and layer-specific strain parameters.The layer-specific strain parameters included subendomyocardial global longitudinal strain (GLSendo), mid-layer myocardial global longitudinal strain (GLSmid), subepimyocardial global longitudinal strain (GLSepi), subendomyocardial global circumferential strain (GCSendo), mid-layer myocardial global circumferential strain (GCSmid), and subepimyocardial global circumferential strain (GCSepi). RESULTS: There were no significant differences in age, body mass index (BMI), blood pressure, or left ventricular ejection fraction (LVEF) between the two groups. The end-diastolic interventricular septal thickness (IVST) was greater in the POI group (8.29 ± 1.32 vs. 7.66 ± 0.82, P = 0.008), and the POI group had lower E, E/A, and lateral e' (all P < 0.05). As for systolic functions,the POI group had lower GLSendo, GLSmid, GLSepi, GCSendo, GCSmid, and GCSepi (all P < 0.05).The intraobserver and interobserver coefficients of GLSendo, GLSmid, GLSepi, GCSendo, GCSmid, and GCSepi were greater than 0.900. CONCLUSIONS: POI patients with normal LVEF may suffer from subclinical left ventricular myocardial systolic dysfunction. Echocardiography of layer-specific myocardial strain could more sensitively detect subclinical impairment of left ventricular systolic function in POI patients.

Inner strength, coping self-efficacy and coping strategy of patients with peritoneal dialysis: A exploratory cross-sectional study.

AIM: The purpose of the study was to investigate and analyse inner strength of patients with peritoneal dialysis, explore the associations among inner strength, coping self-efficacy (CSE) and medial coping modes. DESIGN: This was a cross-sectional study which was conducted in nephrology departments of two affiliated hospitals of a comprehensive university in China. Convenience sampling was chosen to collect data. METHODS: A total of 191 patients undergoing peritoneal dialysis were recruited by convenience sampling in two hospitals. Data involved of sociodemographic and clinical materials, inner strength, CSE and medical coping modes were collected from the patients. IBM SPSS Statistics 21.0 was used to process and analyse the data. RESULTS: The averaged score of inner strength was 95.74 (SD = 13.52). The inner strength, CSE and confrontation coping had positive associations with each other. Besides, inner strength and CSE was negatively associated with acceptance-resignation coping strategy, respectively.

Integrated network pharmacology and metabolomics to study the potential mechanism of Jiawei Yinchenhao decoction in chronic hepatitis B.

Chronic hepatitis B infection (CHB) is a major risk factor for the development of hepatocellular carcinoma (HCC) globally and continues to pose a significant global health challenge. Jiawei Yinchenhao decoction (JWYCH) is a modified version of Yinchenhao decoction (YCHD), which is widely used to treat liver diseases including icteric hepatitis, cholelithiasis, and hepatic ascites. However, the effectiveness and underlying mechanism of JWYCH on CHB are still unclear. This study aimed to investigate the impact of JWYCH on CHB and explore the underlying mechanism via network pharmacology and metabolomics. C57BL/6 mice were administered rAAV-HBV1.3 via hydrodynamic injection (HDI) to establish the CHB model. The infected mice were orally administered JWYCH for 4 weeks. HBsAg, HBeAg, HBV DNA, the serum liver function index, and histopathology were detected. In addition, network pharmacology was used to investigate potential targets, whereas untargeted metabolomics analysis was employed to explore the hepatic metabolic changes in JWYCH in CHB mice and identify relevant biomarkers and metabolic pathways. JWYCH was able to reduce HBeAg levels and improve liver pathological changes in mice with CHB. Additionally, metabolomics analysis indicated that JWYCH can influence 105 metabolites, including pipecolic acid, alpha-terpinene, adenosine, and L-phenylalanine, among others. Bile acid metabolism, arachidonic acid metabolism, and retinol metabolism are suggested to be potential targets of JWYCH in CHB. In conclusion, JWYCH demonstrated a hepatoprotective effect on a mouse model of CHB, suggesting a potential alternative therapeutic strategy for CHB. The effect of JWYCH is associated mainly with regulating the metabolism of bile acid, arachidonic acid, and retinol. These differentially abundant metabolites may serve as potential biomarkers and therapeutic targets for CHB.

Exploring chemical markers and identifying phenolic markers using a metabolomics strategy and chemometrics to study the different origins of defatted Coix seed.

Coix seed, a prevalent medicinal and food-homologous plant, is extensively consumed in Asia. It has various pharmacological properties, such as anti-inflammatory and anticancer effects. Coix seed oil, as its main component, is widely produced. However, during the industrial production process of Coix seed oil, substantial byproducts are produced, namely, defatted Coix seeds, which are also worth researching. Currently, it remains unclear whether there will be differences in defatted Coix seeds obtained from different geographical locations, with previous studies reporting that phenolic compounds in defatted Coix seeds have a significant utilization value. In this study, firstly, the TPC and TFC of samples collected in three temperature zones were detected. Subsequently, UPLC-Q-TOF/MS was used to analyze the samples, and a metabolomics data processing strategy and chemometric analysis method were established. We have confirmed the presence of flavonoids and phenolic compounds in 30 batches of Coix seed from different temperature zones in China, and concluded that the overall quality of Coix seed from different batches is relatively stable. With the established strategy, 12 characteristic chemical markers were identified, and 5 valuable phenolic chemical markers were selected for distinguishing the origin of Coix seed and evaluating the quality of defatted Coix seed. Among them, proanthocyanidin A2 has the highest content in defatted Coix seed in subtropical regions, while the content of caffeic acid, naringin, rutin, and chlorogenic acid decreases from north to south. The strategy proposed in this study may provide some basis for the quality control and rational use of defatted Coix seeds.

Causal Relationship Between Autoimmune Arthritis and Temporomandibular Disorders.

OBJECTIVE: Accumulating evidence has indicated a close interrelation between autoimmune arthritis (AA) and temporomandibular disorders (TMD), but the causality is still unclear. The study aimed to explore the causal inference between AA and TMD using a bidirectional Mendelian randomization analysis. METHODS: Online genome-wide association study data on rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis, and TMD were obtained from the FinnGen and IEU databases. Causality was using the inverse variance-weighted method as the primary analysis and supplemented by other methods. Sensitivity analyses, including heterogeneity tests, horizontal pleiotropy tests, and leave-one-out methods, were conducted to investigate the stability and reliability of the results. RESULTS: The inverse variance-weighted test indicated that several AA types could causally increase the TMD risk, including overall RA (odds ratio [OR] = 1.348, 95% confidence interval [CI] = 1.1232-1.618, P = .001), subtype nRA (OR = 1.118, 95% CI = 1.044-1.197, P = .001), and AS (OR = 1.060, 95% CI = 1.024-1.097, P = .001). Moreover, the causal association of the above combinations has been proven to be stable and reliable using sensitivity and other tests. CONCLUSION: These findings suggest that RA and AS might be causally associated with an increased risk of TMD. However, more studies are needed to check the causal effects of AA on TMD and analyse the potential mechanisms further.

Dual-stage semantic segmentation of endoscopic surgical instruments.

BACKGROUND: Endoscopic instrument segmentation is essential for ensuring the safety of robotic-assisted spinal endoscopic surgeries. However, due to the narrow operative region, intricate surrounding tissues, and limited visibility, achieving instrument segmentation within the endoscopic view remains challenging. PURPOSE: This work aims to devise a method to segment surgical instruments in endoscopic video. By designing an endoscopic image classification model, features of frames before and after the video are extracted to achieve continuous and precise segmentation of instruments in endoscopic videos. METHODS: Deep learning techniques serve as the algorithmic core for constructing the convolutional neural network proposed in this study. The method comprises dual stages: image classification and instrument segmentation. MobileViT is employed for image classification, enabling the extraction of key features of different instruments and generating classification results. DeepLabv3+ is utilized for instrument segmentation. By training on distinct instruments separately, corresponding model parameters are obtained. Lastly, a flag caching mechanism along with a blur detection module is designed to effectively utilize the image features in consecutive frames. By incorporating specific parameters into the segmentation model, better segmentation of surgical instruments can be achieved in endoscopic videos. RESULTS: The classification and segmentation models are evaluated on an endoscopic image dataset. In the dataset used for instrument segmentation, the training set consists of 7456 images, the validation set consists of 829 images, and the test set consists of 921 images. In the dataset used for image classification, the training set consists of 2400 images and the validation set consists of 600 images. The image classification model achieves an accuracy of 70% on the validation set. For the segmentation model, experiments are conducted on two common surgical instruments, and the mean Intersection over Union (mIoU) exceeds 98%. Furthermore, the proposed video segmentation method is tested using videos collected during surgeries, validating the effectiveness of the flag caching mechanism and blur detection module. CONCLUSIONS: Experimental results on the dataset demonstrate that the dual-stage video processing method excels in performing instrument segmentation tasks under endoscopic conditions. This advancement is significant for enhancing the intelligence level of robotic-assisted spinal endoscopic surgeries.

Catalytic Enantioselective Synthesis of Planar Chiral Pillar[5]arenes via Asymmetric Sonogashira Coupling.

As a novel type of macrocycles with attractive planar chirality, pillar[5]arenes have gained increasing research interest over the past decades, enabling their widespread applications in diverse fields such as porous materials, molecular machines, and chiral luminescence materials. However, the catalytic methodology towards the enantioselective synthesis of planar chiral pillar[5]arenes remains elusive. Here we report a novel method for the enantioselective synthesis of planar chiral pillar[5]arenes via asymmetric Sonogashira coupling, giving access to a wide range of highly functionalized planar chiral pillar[5]arenes, including both homo- and hetero-rimmed ones, with excellent enantioselectivities. Attractively, the resultant planar chiral pillar[5]arenes show great potential for widespread use in many areas such as chiral luminescent materials. This work not only enables the successful synthesis of planar chiral pillar[5]arenes with abundant structural and functional diversity as key building blocks for practical applications but also enriches the asymmetric cross-coupling methodologies in organic synthetic chemistry.

Critical role of apoptosis in MeCP2-mediated epithelial-mesenchymal transition of ARPE-19 cells.

Proliferative vitreoretinopathy (PVR) is a complex disease that significantly contributes to recurrent retinal detachment. Its development is notably affected by epithelial-mesenchymal transition (EMT), where apoptosis plays a crucial role as a regulator of EMT. However, the function of MeCP2 in governing apoptosis and EMT in retinal pigment epithelial (RPE) cells and its implications for PVR development have remained inadequately understood. Thus, we investigated the impact of MeCP2 on proliferation, migration, apoptosis and EMT in ARPE-19 cells to provide a fresh perspective on the etiology of PVR. The morphological changes in ARPE-19 cells induced by recombinant human MeCP2 protein and MeCP2 knockdown were observed. Wound healing assay were performed to verify the effects of recombinant human MeCP2 protein and MeCP2 knockdown on ARPE-19 cell migration. Furthermore, cell proliferation was assessed using the CCK-8 assay and flow cytometry. Western blot analysis, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), and immunofluorescence analysis were conducted to measure the protein levels associated with apoptosis, cell cycle and EMT. Western blot analysis and immunofluorescence assays confirmed that MeCP2 promoted EMT formation in ARPE-19 cells. The CCK-8 assay revealed that MeCP2 treatment enhanced the proliferation of ARPE-19 cells, whereas MeCP2 knockdown inhibited ARPE-19 cell proliferation. Treatment with recombinant human MeCP2 protein and MeCP2 knockdown altered the morphology of ARPE-19 cells. Wound healing assay demonstrated that MeCP2 knockdown inhibited ARPE-19 cell migration, and MeCP2 treatment promoted ARPE-19 cell migration. MeCP2 knockdown induced a G0/G1 phase block, inhibiting cell growth, and qRT-PCR data indicated reduced expression of cell cycle-related genes. Increased apoptosis was observed after MeCP2 knockdown in ARPE-19 cells. Overall, MeCP2 treatment stimulates cell proliferation, migration and EMT formation; conversely, MeCP2 knockdown inhibits EMT, cell proliferation, migration and cell cycle G1/S phase transition, and induces apoptosis.

PoCXCL8, a teleost chemokine, exerts direct bactericidal, chemotactic/phagocytic, and NETs releasing properties, promoting host anti-bacterial immunity.

As an important CXC chemokine, CXCL8 plays pleiotropic roles in immunological response. In teleost, CXCL8 is involved in cell migration and bacterial invasion. However, the immune antibacterial function of CXCL8 in Japanese flounder (Paralichthys olivaceus) (PoCXCL8) is largely scarce. In this research, we investigated the antibacterial property and leukocyte activation of PoCXCL8. PoCXCL8 consists of 100 amino acid residues, with a conserved chemokine CXC domain. PoCXCL8 was expressed in various tissues, with the highest level in liver and the lowest level in muscle, and sharply induced by V. harveyi or E. tarda in liver, spleen, and head kidney. In vitro, the recombinant PoCXCL8 (rPoCXCL8) could bind to Bacillus subtilis, Edwardsiella tarda, Escherichia coli, Pseudomonas fluorescens, Vibrio anguillarum, Vibrio harveyi, Staphylococcus aureus, and Micrococcus luteus, affect the growth of E. coli, E. tarda, M. luteus, and P. fluorescens, and have a direct bactericidal effect on E. coli and E. tarda. Moreover, rPoCXCL8 was able to bind the outer membranal protein rPilA of E. tarda. In addition, rPoCXCL8 could bind to PBLs, activating the PBLs activity including chemotaxis, proliferation, phagocytosis, reactive oxygen species, acid phosphatase activity. At same time, rPoCXCL8 could induce neutrophil to generate neutrophil extracellular traps (NETs) and promote the expression of inflammatory genes including IL-1ß, IL6, MMP13, TNF-α, and NF-κB. In flounder, the presence of rPoCXCL8 could enhance the in vivo resistance to E. tarda in liver, spleen, and head kidney. Moreover, the PoCXCL8-deficient could attenuate the fish defense against E. tarda infection in in spleen and head kidney. In conclusion, these results provided new insights into the antibacterial properties of CXCL8 in P. olivaceus.

Nomogram construction and evaluation for predicting non-remission after a single radioactive iodine therapy for Graves' hyperthyroidism: a retrospective cohort study.

Background: Radioactive iodine (RAI) therapy is a widely used treatment for Graves' Hyperthyroidism (GH). However, various factors can impact the non-remission rate of GH after single RAI therapy. This study aimed to develop an online dynamic nomogram to assist physicians in providing personalized therapy for GH. Methods: Data from 454 GH patients who received RAI therapy were retrospectively reviewed and included in the present study. The univariate and multivariate analysis were conducted to investigate and identify independent influencing factors. The nomogram was developed based on the training cohort to explore non-remission rates. Finally, the reliability and accuracy of the constructed nomogram model were verified in the validation cohort via the calibration, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA). Results: 24-hours radioactive iodine uptake (RAIU24h), effective half-life (Teff), total iodine dose (TID) and iodine dose per gram of thyroid tissue (IDPG) were independent predictors. The nomogram had a high C-index 0.922 (95% CI: 0.892-0.953), for predicting non-remission. The calibration curves demonstrated excellent consistency between the predicted and the actual probability of non-remission. ROC analysis showed that the AUC of the nomogram model and the four independent factors in the training cohort were 0.922, 0.673, 0.760, 0.761, and 0.786, respectively. The optimal cutoff value for the total nomogram scores was determined to be 155. A total score of ≥155 indicates a higher likelihood of non-remission after a single RAI therapy for GH, whereas a score below 155 suggests a greater likelihood of remission. Additionally, the DCA curve indicated that this nomogram had good clinical utility in predicting non-remission. Conclusion: An online nomogram was constructed with good predictive performance, which can be used as a practical approach to predict and assist physicians in making personalized therapy decisions for GH patients.

Identification and screening of priority pollutants in printing and dyeing industry wastewater and the importance of these pollutants in environmental management in China.

At present, priority pollutants in printing and dyeing wastewater have attracted increasing attention, but their types and limits in the wastewater discharge standards for China's dyeing and finishing industry are still lacking. This study selected 9 printing and dyeing enterprises in a region of Zhejiang Province as the research objects. Through literature collection, field investigations, and chemical analysis, combined with industry priority pollutant screening technology, 103 and 21 characteristic pollutants were selected as preliminary and supplementary lists of priority pollutants, respectively. The results of the pollutant category analysis revealed that 55% of the pollutants on the preliminary list included carcinogens, and 29% of the pollutants on the supplementary list included alcohols. According to the four rules for in-depth screening, a total of 23 indicators (excluding those in GB 4287-2012 and its revised versions) were selected as the final list of priority pollutants, most of which were polycyclic aromatic hydrocarbons (PAHs) but also included a small number of lipid substances, such as bis (2-ethylhexyl) phthalate. The screening of these indicators not only provides data support for the expansion of water pollution control indicators and the determination of their limits in China's printing and dyeing industry, but also promotes the supplementation and improvement of the sewage discharge standard system in related industries.

ASCT2 Regulates Fatty Acid Metabolism to Trigger Glutamine Addiction in Basal-like Breast Cancer.

As a crucial amino acid, glutamine can provide the nitrogen and carbon sources needed to support cancer cell proliferation, invasion, and metastasis. Interestingly, different types of breast cancer have different dependences on glutamine. This research shows that basal-like breast cancer depends on glutamine, while the other types of breast cancer may be more dependent on glucose. Glutamine transporter ASCT2 is highly expressed in various cancers and significantly promotes the growth of breast cancer. However, the key regulatory mechanism of ASCT2 in promoting basal-like breast cancer progression remains unclear. Our research demonstrates the significant change in fatty acid levels caused by ASCT2, which may be a key factor in glutamine sensitivity. This phenomenon results from the mutual activation between ASCT2-mediated glutamine transport and lipid metabolism via the nuclear receptor PPARα. ASCT2 cooperatively promoted PPARα expression, leading to the upregulation of lipid metabolism. Moreover, we also found that C118P could inhibit lipid metabolism by targeting ASCT2. More importantly, this research identifies a potential avenue of evidence for the prevention and early intervention of basal-like breast cancer by blocking the glutamine-lipid feedback loop.

Bifunctional ArsI Dioxygenase from Acidovorax sp. ST3 with Both Methylarsenite [MAs(III)] Demethylation and MAs(III) Oxidation Activities.

Methylated arsenicals, including highly toxic species, such as methylarsenite [MAs(III)], are pervasive in the environment. Certain microorganisms possess the ability to detoxify MAs(III) by ArsI-catalyzed demethylation. Here, we characterize a bifunctional enzyme encoded by the arsI gene from Acidovorax sp. ST3, which can detoxify MAs(III) through both the demethylation and oxidation pathways. Deletion of the 22 C-terminal amino acids of ArsI increased its demethylation activity while reducing the oxidation activity. Further deletion of 44 C-terminal residues enhanced the MAs(III) demethylation activity. ArsI has four vicinal cysteine pairs, with the first pair being necessary for MAs(III) demethylation, while at least one of the other three pairs contributes to MAs(III) oxidation. Molecular modeling and site-directed mutagenesis indicated that one of the C-terminal vicinal cysteine pairs is involved in modulating the switch between oxidase and demethylase activity. These findings underscore the critical role of the C-terminal region in modulating the enzymatic activities of ArsI, particularly in MAs(III) demethylation. This research reveals the structure-function relationship of the ArsI enzyme and advances our understanding of the MAs(III) metabolism in bacteria.

Antimicrobial blue light inactivation of Pseudomonas aeruginosa: Unraveling the multifaceted impact of wavelength, growth stage, and medium composition.

Pseudomonas aeruginosa, a notable pathogen frequently associated with hospital-acquired infections, displays diverse intrinsic and acquired antibiotic resistance mechanisms, posing a significant challenge in infection management. Antimicrobial blue light (aBL) has been demonstrated as a potential alternative for treating P. aeruginosa infections. In this study, we investigated the impact of blue light wavelength, bacterial growth stage, and growth medium composition on the efficacy of aBL. First, we compared the efficacy of light wavelengths 405 nm, 415 nm, and 470 nm in killing three multidrug resistant clinical strains of P. aeruginosa. The findings indicated considerably higher antibacterial efficacy for 405 nm and 415 nm wavelength compared to 470 nm. We then evaluated the impact of the bacterial growth stage on the efficacy of 405 nm light in killing P. aeruginosa using a reference strain PAO1 in exponential, transitional, or stationary phase. We found that bacteria in the exponential phase were the most susceptible to aBL, followed by the transitional phase, while those in the stationary phase exhibited the highest tolerance. Additionally, we quantified the production of reactive oxygen species (ROS) in bacteria using the 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe and flow cytometry, and observed a positive correlation between aBL efficacy and ROS production. Finally, we determined the influence of growth medium on aBL efficacy. PAO1 was cultivated in brain heart infusion (BHI), Luria-Bertani (LB) broth or Casamino acids (CAA) medium, before being irradiated with aBL at 405 nm. The CAA-grown bacteria exhibited the highest sensitivity to aBL, followed by those grown in LB broth, and the BHI-grown bacteria demonstrated the lowest sensitivity. By incorporating FeCl3, MnCl2, ZnCl2, or the iron chelator 2,2'-bipyridine (BIP) into specific media, we discovered that aBL efficacy was affected by the iron levels in culture media.

Printing of 3D photonic crystals in titania with complete bandgap across the visible spectrum.

A photonic bandgap is a range of wavelengths wherein light is forbidden from entering a photonic crystal, similar to the electronic bandgap in semiconductors. Fabricating photonic crystals with a complete photonic bandgap in the visible spectrum presents at least two important challenges: achieving a material refractive index > ~2 and a three-dimensional patterning resolution better than ~280 nm (lattice constant of 400 nm). Here we show an approach to overcome such limitations using additive manufacturing, thus realizing high-quality, high-refractive index photonic crystals with size-tunable bandgaps across the visible spectrum. We develop a titanium ion-doped resin (Ti-Nano) for high-resolution printing by two-photon polymerization lithography. After printing, the structures are heat-treated in air to induce lattice shrinkage and produce titania nanostructures. We attain three-dimensional photonic crystals with patterning resolution as high as 180 nm and refractive index of 2.4-2.6. Optical characterization reveals ~100% reflectance within the photonic crystal bandgap in the visible range. Finally, we show capabilities in defining local defects and demonstrate proof-of-principle applications in spectrally selective perfect reflectors and chiral light discriminators.

Application of Pro-angiogenic Biomaterials in Myocardial Infarction.

Biomaterials have potential applications in the treatment of myocardial infarction (MI). These biomaterials have the ability to mechanically support the ventricular wall and to modulate the inflammatory, metabolic, and local electrophysiological microenvironment. In addition, they can play an equally important role in promoting angiogenesis, which is the primary prerequisite for the treatment of MI. A variety of biomaterials are known to exert pro-angiogenic effects, but the pro-angiogenic mechanisms and functions of different biomaterials are complex and diverse, and have not yet been systematically described. This review will focus on the pro-angiogenesis of biomaterials and systematically describe the mechanisms and functions of different biomaterials in promoting angiogenesis in MI.