Discovery of PXR agonists from Hypericum japonicum: A class of novel nonaromatic acylphloroglucinol-terpenoid adducts.

Pregnane X receptor (PXR) has been considered as a promising therapeutic target for cholestasis due to its crucial regulation in bile acid biosynthesis and metabolism. To search promising natural PXR agonists, the PXR agonistic activities of five traditional Chinese medicines (TCMs) with hepatoprotective efficacy were assayed, and Hypericum japonicum as the most active one was selected for subsequent phytochemical investigation, which led to the isolation of eight nonaromatic acylphloroglucinol-terpenoid adducts including seven new compounds (1 - 4, 5a, 5b and 6). Their structures including absolute configurations were determined by comprehensive spectroscopic, computational and X-ray diffraction analysis. Meanwhile, the PXR agonistic activities of aplenty compounds were evaluated via dual-luciferase reporter assay, RT-qPCR and immunofluorescence. Among them, compounds 1 - 4 showed more potent activity than the positive drug rifampicin. Furthermore, the molecular docking revealed that 1 - 4 were docked well on the PXR ligand binding domain and formed hydrogen bonds with amino acid residues Gln285, Ser247 and His409. This investigation revealed that H. japonicum may serve as a rich source of natural PXR agonists.

Primase and polymerase α tango to make an RNA-DNA hybrid primer.

Several recent cryo-electron microscopy (cryo-EM) studies about the eukaryotic primosome, including the human primosome described by Yin et al. in this issue, have uncovered the structural intricacies between the RNA primase and the DNA polymerase. These studies show that these two partners tango on DNA to synthesize a hybrid primer composed of ~ 10 nucleotide (nt) RNA and ~ 10-nt DNA. They reveal key intermediate steps involved in this process; from the self-inhibited apo state to the initiation of RNA primer synthesis, RNA primer handover to the polymerase, primer elongation by polymerase, and finally, primer termination and release. Remarkably, the polymerase domain orchestrates all major steps during primer synthesis.

Association of circulating inflammatory proteins with type 2 diabetes mellitus and its complications: a bidirectional Mendelian randomization study.

Background: Increasing evidence indicates that immune response underlies the pathology of type 2 diabetes (T2D). Nevertheless, the specific inflammatory regulators involved in this pathogenesis remain unclear. Methods: We systematically explored circulating inflammatory proteins that are causally associated with T2D via a bidirectional Mendelian randomization (MR) study and further investigated them in prevalent complications of T2D. Genetic instruments for 91 circulating inflammatory proteins were derived from a genome-wide association study (GWAS) that enrolled 14,824 predominantly European participants. Regarding the summary-level GWASs of type 2 diabetes, we adopted the largest meta-analysis of European population (74,124 cases vs. 824,006 controls) and a prospective nested case-cohort study in Europe (9,978 cases vs. 12,348 controls). Summary statistics for five complications of T2D were acquired from the FinnGen R9 repository. The inverse variance-weighted method was applied as the primary method for causal inference. MR-Egger, weighted median and maximum likelihood methods were employed as supplementary analyses. Results from the two T2D studies were combined in a meta-analysis. Sensitivity analyses and phenotype-wide association studies (PheWAS) were performed to detect heterogeneity and potential horizontal pleiotropy in the study. Results: Genetic evidence indicated that elevated levels of TGF-α (OR = 1.16, 95% CI = 1.15-1.17) and CX3CL1 (OR = 1.30, 95% CI = 1.04-1.63) promoted the occurrence of T2D, and increased concentrations of FGF-21 (OR = 0.87, 95% CI = 0.81-0.93) and hGDNF (OR = 0.96, 95% CI = 0.95-0.98) mitigated the risk of developing T2D, while type 2 diabetes did not exert a significant influence on said proteins. Elevated levels of TGF-α were associated with an increased risk of ketoacidosis, neurological complications, and ocular complications in patients with T2D, and increased concentrations of FGF-21 were potentially correlated with a diminished risk of T2D with neurological complications. Higher levels of hGDNF were associated with an increased risk of T2D with peripheral vascular complications, while CX3CL1 did not demonstrate a significant association with T2D complications. Sensitivity analyses and PheWAS further ensure the robustness of our findings. Conclusion: This study determined four circulating inflammatory proteins that affected the occurrence of T2D, providing opportunities for the early prevention and innovative therapy of type 2 diabetes and its complications.

Low initial cell density promotes the differentiation and maturation of human pluripotent stem cells into erythrocytes.

Human pluripotent stem cell (hPSC)-derived red blood cells (RBCs) possess great potential for compensating shortages in transfusion medicine. For better RBC generation from hPSCs, we compared the cell seeding density in the embryoid body formation-based hPSC induction protocol. In the selection of low- and high-density inoculation conditions, we found that low-density culture performed better in the final RBC product with more cell output and increased average cellular hemoglobin content. An elaborate study using flow cytometry demonstrated that low inoculation density promoted endothelial-to-hematopoietic transition, followed by improved hematopoietic progenitor formation and erythrocyte generation. The improved transformation from glycolysis to mitochondrial oxidation and reduced apoptosis might be responsible for this effect. Hints from RNA sequencing suggested that molecules involved in microenvironment interaction and metabolic regulation might respond for the different developmental potential. The possible mediators between outer message and intracellular response could be the nutrition sensors FOXO, PRKAA1 (AMPK) and MTOR genes. It is possible that low inoculation density triggered metabolic regulation signals, promoted mitochondrial oxidation, and resulted in enhanced cell amplification and hematopoietic differentiation. The low cell culture density will improve RBC generation from human PSCs.

Gut microbiome is associated with recurrence-free survival in patients with resected Stage IIIB-D or Stage IV melanoma treated with immune checkpoint inhibitors.

The gut microbiome (GMB) has been associated with outcomes of immune checkpoint blockade therapy in melanoma, but there is limited consensus on the specific taxa involved, particularly across different geographic regions. We analyzed pre-treatment stool samples from 674 melanoma patients participating in a phase-III trial of adjuvant nivolumab plus ipilimumab versus nivolumab, across three continents and five regions. Longitudinal analysis revealed that GMB was largely unchanged following treatment, offering promise for lasting GMB-based interventions. In region-specific and cross-region meta-analyses, we identified pre-treatment taxonomic markers associated with recurrence, including Eubacterium, Ruminococcus, Firmicutes , and Clostridium . Recurrence prediction by these markers was best achieved across regions by matching participants on GMB compositional similarity between the intra-regional discovery and external validation sets. AUCs for prediction ranged from 0.83-0.94 (depending on the initial discovery region) for patients closely matched on GMB composition (e.g., JSD ≤0.11). This evidence indicates that taxonomic markers for prediction of recurrence are generalizable across regions, for individuals of similar GMB composition. Highlights: Overall gut microbiome (GMB) composition is largely unchanged during ICB treatment.GMB composition varies by geographic regionWe identified gut bacterial markers associated with recurrence in region-specific analyses.Region-identified markers are generalizable if GMB composition is taken into account by matching.

Dysregulation of ferroptosis may participate in the mitigating effect of CoCl2 on contrast-induced nephropathy / La desregulación de ferroptosis puede participar en el efecto mitigador de CoCl2 en la nefropatía inducida por contraste

Background: Contrast agents can directly or indirectly induce renal tubular ischemia and hypoxic damage. Given that cobalt chloride (CoCl2) can protect renal tubules, the protective effect and potential mechanism of action of CoCl2 on contrast-induced nephropathy (CIN) warrant investigation. Methods: A CIN mouse model was established to determine the protective effect of CoCl2 on renal injury in vivo. Then, TMT-based proteomics was performed to determine the differentially expressed proteins (DEPs), following which, enrichment analyses of gene ontology and the KEGG pathway were performed. In vitro, a CIN model was constructed with renal tubular epithelial cells (HK-2) to determine the effect of CoCl2 on potential targets and the role of the key protein identified from the in vivo experiments. Results: CoCl2 treatment decreased the levels of BUN and serum creatinine (sCr), while increasing the levels of urea and creatinine (Cr) in the urine of mice after CIN injury. Damage to the renal tubules in the CoCl2 treatment group was significantly less than in the CIN model group. We identified 79 DEPs after treating the in vivo model with CoCl2, and frequently observed ferroptosis-related GO and KEGG pathway terms. Of these, Hp (haptoglobin) was selected and found to have a strong renoprotective effect, even though its expression level in kidney tissue decreased after CoCl2 treatment. In HK-2 cells, overexpression of Hp reduced the ferroptosis caused by erastin, while knocking down Hp negated the attenuation effect of CoCl2 on HK-2 cell ferroptosis. Conclusion: CoCl2 attenuated kidney damage in the CIN model, and this effect was associated with the decrease in ferroptosis mediated by Hp.(AU)

Antecedentes: Los agentes de contraste pueden inducir isquemia tubular renal y daño hipóxico de manera directa o indirecta. Dado que el cloruro de cobalto (CoCl2) puede proteger los túbulos renales, el efecto protector y el mecanismo de acción potencial de CoCl2 en la nefropatía inducida por contraste (NIC) merecen ser investigados. Métodos: Se estableció un modelo de NIC en ratones para determinar el efecto protector de CoCl2 en la nefropatía in vivo. Seguidamente, se realizó un análisis proteómico por TMT para determinar las proteínas diferencialmente expresadas (DEP) y, a continuación, un análisis de enriquecimiento de ontología genética y vía KEGG. In vitro, se construyó un modelo NIC en células epiteliales de túbulos renales (HK-2) para determinar el efecto de CoCl2 en los objetivos potenciales y el rol de la proteína clave identificada en los experimentos in vivo. Resultados: El tratamiento con CoCl2 redujo los niveles de BUN y de creatinina sérica e incrementó, a la vez, los de urea y creatinina en la orina de los ratones, tras la lesión NIC. El daño a los túbulos renales en el grupo de tratamiento con CoCl2 fue significativamente menor que en el grupo de modelo NIC. Identificamos 79 DEP tras el tratamiento en el modelo in vivo con CoCl2 y observamos con frecuencia ontología genética relacionada con ferroptosis y términos de vías KEGG. De ellos, se seleccionó la haptoglobina (Hp) y se encontró que tenía un fuerte efecto renoprotector, aun cuando su nivel de expresión en el tejido renal se redujo tras el tratamiento con CoCl2. En las células HK-2, la sobreexpresión de Hp redujo la ferroptosis causada por erastina, a pesar de que el descenso de Hp negó el efecto atenuador de CoCl2 en la ferroptosis de las células HK-2. Conclusión: El CoCl2 atenuó el daño renal en el modelo NIC y se asoció este efecto al descenso de ferroptosis mediada por Hp.(AU)

Tailoring d-band center of high-valent metal-oxo species for pollutant removal via complete polymerization.

Polymerization-driven removal of pollutants in advanced oxidation processes (AOPs) offers a sustainable way for the simultaneous achievement of contamination abatement and resource recovery, supporting a low-carbon water purification approach. However, regulating such a process remains a great challenge due to the insufficient microscopic understanding of electronic structure-dependent reaction mechanisms. Herein, this work probes the origin of catalytic pollutant polymerization using a series of transition metal (Cu, Ni, Co, and Fe) single-atom catalysts and identifies the d-band center of active site as the key driver for polymerization transfer of pollutants. The high-valent metal-oxo species, produced via peroxymonosulfate activation, are found to trigger the pollutant removal via polymerization transfer. Phenoxyl radicals, identified by the innovative spin-trapping and quenching approaches, act as the key intermediate in the polymerization reactions. More importantly, the oxidation capacity of high-valent metal-oxo species can be facilely tuned by regulating their binding strength for peroxymonosulfate through d-band center modulation. A 100% polymerization transfer ratio is achieved by lowering the d-band center. This work presents a paradigm to dynamically modulate the electronic structure of high-valent metal-oxo species and optimize pollutant removal from wastewater via polymerization.

Structure of the PCNA unloader Elg1-RFC.

During DNA replication, the proliferating cell nuclear antigen (PCNA) clamps are loaded onto primed sites for each Okazaki fragment synthesis by the AAA+ heteropentamer replication factor C (RFC). PCNA encircling duplex DNA is quite stable and is removed from DNA by the dedicated clamp unloader Elg1-RFC. Here, we show the cryo-EM structure of Elg1-RFC in various states with PCNA. The structures reveal essential features of Elg1-RFC that explain how it is dedicated to PCNA unloading. Specifically, Elg1 contains two external loops that block opening of the Elg1-RFC complex for DNA binding, and an "Elg1 plug" domain that fills the central DNA binding chamber, thereby reinforcing the exclusive PCNA unloading activity of Elg1-RFC. Elg1-RFC was capable of unloading PCNA using non-hydrolyzable AMP-PNP. Both RFC and Elg1-RFC could remove PCNA from covalently closed circular DNA, indicating that PCNA unloading occurs by a mechanism that is distinct from PCNA loading. Implications for the PCNA unloading mechanism are discussed.

Total Synthesis of the Euphorbia Diterpenoid Pepluacetal.

The first total synthesis of the Euphorbia diterpenoid pepluacetal is disclosed in both racemic and chiral fashions. The synthesis strategically relies on a photo-induced Wolff rearrangement/lactonization cascade (WRLC) reaction to access the cyclobutane moiety, a ring-closing metathesis/cyclopropanation sequence to rapidly forge the 7-3 bicyclic system, and a late-stage Rh-catalyzed transannular carbenoid insertion to C(sp3)-H bond followed by a Baeyer-Villiger oxidation and ring-opening manipulations to install the side chain. The synthetic route demonstrates excellent stereochemical control on the non-classical concave-face bond formation, remote traceless stereochemical relay and high scalability to provide 20 mg of (+)-pepluacetal.

Sociobiome - Individual and neighborhood socioeconomic status influence the gut microbiome in a multi-ethnic population in the US.

Lower socioeconomic status (SES) is related to increased incidence and mortality due to chronic diseases in adults. Association between SES variables and gut microbiome variation has been observed in adults at the population level, suggesting that biological mechanisms may underlie the SES associations; however, there is a need for larger studies that consider individual- and neighborhood-level measures of SES in racially diverse populations. In 825 participants from a multi-ethnic cohort, we investigated how SES shapes the gut microbiome. We determined the relationship of a range of individual- and neighborhood-level SES indicators with the gut microbiome. Individual education level and occupation were self-reported by questionnaire. Geocoding was applied to link participants' addresses with neighborhood census tract socioeconomic indicators, including average income and social deprivation in the census tract. Gut microbiome was measured using 16SV4 region rRNA gene sequencing of stool samples. We compared α-diversity, ß-diversity, and taxonomic and functional pathway abundance by SES. Lower SES was significantly associated with greater α-diversity and compositional differences among groups, as measured by ß-diversity. Several taxa related to low SES were identified, especially an increasing abundance of Prevotella copri and Catenibacterium sp000437715, and decreasing abundance of Dysosmobacter welbionis in terms of their high log-fold change differences. In addition, nativity and race/ethnicity have emerged as ecosocial factors that also influence the gut microbiota. Together, these results showed that lower SES was strongly associated with compositional and taxonomic measures of the gut microbiome, and may contribute to shaping the gut microbiota.

P. aeruginosa CtpA protease adopts a novel activation mechanism to initiate the proteolytic process.

During bacterial cell growth, hydrolases cleave peptide cross-links between strands of the peptidoglycan sacculus to allow new strand insertion. The Pseudomonas aeruginosa carboxyl-terminal processing protease (CTP) CtpA regulates some of these hydrolases by degrading them. CtpA assembles as an inactive hexamer composed of a trimer-of-dimers, but its lipoprotein binding partner LbcA activates CtpA by an unknown mechanism. Here, we report the cryo-EM structures of the CtpA-LbcA complex. LbcA has an N-terminal adaptor domain that binds to CtpA, and a C-terminal superhelical tetratricopeptide repeat domain. One LbcA molecule attaches to each of the three vertices of a CtpA hexamer. LbcA triggers relocation of the CtpA PDZ domain, remodeling of the substrate binding pocket, and realignment of the catalytic residues. Surprisingly, only one CtpA molecule in a CtpA dimer is activated upon LbcA binding. Also, a long loop from one CtpA dimer inserts into a neighboring dimer to facilitate the proteolytic activity. This work has revealed an activation mechanism for a bacterial CTP that is strikingly different from other CTPs that have been characterized structurally.

Structural insight into an Arl1-ArfGEF complex involved in Golgi recruitment of a GRIP-domain golgin.

Arl1 is an Arf-like (Arl) GTP-binding protein that interacts with the guanine nucleotide exchange factor Gea2 to recruit the golgin Imh1 to the Golgi. The Arl1-Gea2 complex also binds and activates the phosphatidylserine flippase Drs2 and these functions may be related, although the underlying molecular mechanism is unclear. Here we report high-resolution cryo-EM structures of the full-length Gea2 and the Arl1-Gea2 complex. Gea2 is a large protein with 1459 residues and is composed of six domains (DCB, HUS, SEC7, HDS1-3). We show that Gea2 assembles a stable dimer via an extensive interface involving hydrophobic and electrostatic interactions in the DCB and HUS region. Contrary to the previous report on a Gea2 homolog in which Arl1 binds to the dimerization surface of the DCB domain, implying a disrupted dimer upon Arl1 binding, we find that Arl1 binds to the outside surface of the Gea2 DCB domain, leaving the Gea2 dimer intact. The interaction between Arl1 and Gea2 involves the classic FWY aromatic residue triad as well as two Arl1-specific residues. We show that key mutations that disrupt the Arl1-Gea2 interaction abrogate Imh1 Golgi association. This work clarifies the Arl1-Gea2 interaction and improves our understanding of molecular events in the membrane trafficking.

Effect of Infusion Set Replacement Intervals on Central Line-Associated Bloodstream Infection in the Intensive Care Unit: Study Protocol of the INSPIRATION Study.

INTRODUCTION: The replacement intervals for infusion sets may differ among healthcare institutions, which may have an impact on the occurrence of central line-associated bloodstream infections (CLABSI). Nevertheless, there exists a limited amount of high-quality evidence available to assist clinicians in determining the most suitable replacement intervals for infusion sets. Therefore, the objective of this trial is to compare the efficacy of 24-h and 96-h replacement intervals for infusion sets on CLABSI among critically ill adults who have central venous access devices. METHODS: This is a multicenter, parallel-group randomized controlled trial that will investigate the effect of infusion set replacement intervals on CLABSI in adult patients admitted to intensive care units (ICUs). The study will enroll 1240 participants who meet the inclusion criteria, which includes being 18 years or older, expected to stay in the ICU for longer than 96 h, and in need of central venous access. Participants will be randomly assigned to either a control group receiving a 96-h replacement interval or a treatment group receiving a 24-h replacement interval. PLANNED OUTCOME: The primary outcome of this trial is the rate of CLABSI within 28 days after randomization. CONCLUSION: This is the first randomized controlled trial to investigate the effects of infusion set replacement at 24-h and 96-h intervals on CLABSI in ICU patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT05359601.

Feasibility of a family-oriented mHealth intervention for Chinese Americans with type 2 diabetes: A pilot randomized control trial.

OBJECTIVES: To test the feasibility, acceptability, and potential efficacy of a mHealth intervention tailored for Chinese immigrant families with type 2 diabetes (T2D). METHODS: We conducted a pilot randomized controlled trial (RCT) with baseline, 3-, and 6-month measurements. Participating dyads, T2D patients and families/friends from NYC, were randomized into the intervention group (n = 11) or the wait-list control group (n = 12). Intervention includes 24 videos covering T2D self-management, behavioral techniques, and family-oriented sessions. Feasibility and acceptability were measured respectively by the retention rate and video watch rate, and a satisfaction survey. Patients' HbA1c, weight, and self-management were also assessed to test potential efficacy. RESULTS: Most T2D patients (n = 23; mean age 56.2±9.4 years; 52.2% male) and families/friends (n = 23, mean age 54.6±11.2 years; 52.2% female) had high school education or less (69.6% and 69.6%), annual household income < $25,000 (65.2% and 52.2%), and limited English proficiency (95.7% and 95.7%). The retention rates were not significantly different between the intervention and the control groups for both the patients (90.91% vs 83.3%, p = 0.589); and their families/friends (3-month: 90.9% vs 75%, p = 0.313; 6-month: 90.9% vs 83.3%, p = 0.589). The mean video watch rate was 76.8% (7%). T2D patients and families/friends rated satisfaction as 9.4 and 10 out of 10, respectively. Despite no between-group differences, the intervention group had significantly lower HbA1c (p = 0.014) and better self-management (p = 0.009), and lost 12 lbs. on average at 6 months (p = 0.079), compared to their baseline levels. CONCLUSIONS: A culturally-tailored, family-based mHealth intervention is feasible and acceptable among low-income, limited English-proficient Chinese families with T2D in NYC. Significant changes in HbA1c and self-management within the intervention group indicate this intervention may have potential efficacy. Given the small sample size of this study, a future RCT with adequate power is needed to test efficacy.

Formation of Different Polyploids Through Disrupting Meiotic Crossover Frequencies Based on cntd1 Knockout in Zebrafish.

Polyploidy, a significant catalyst for speciation and evolutionary processes in both plant and animal kingdoms, has been recognized for a long time. However, the exact molecular mechanism that leads to polyploid formation, especially in vertebrates, is not fully understood. Our study aimed to elucidate this phenomenon using the zebrafish model. We successfully achieved an effective knockout of the cyclin N-terminal domain containing 1 (cntd1) using CRISPR/Cas9 technology. This resulted in impaired formation of meiotic crossovers, leading to cell-cycle arrest during meiotic metaphase and triggering apoptosis of spermatocytes in the testes. Despite these defects, the mutant (cntd1-/-) males were still able to produce a limited amount of sperm with normal ploidy and function. Interestingly, in the mutant females, it was the ploidy not the capacity of egg production that was altered. This resulted in the production of haploid, aneuploid, and unreduced gametes. This alteration enabled us to successfully obtain triploid and tetraploid zebrafish from cntd1-/- and cntd1-/-/- females, respectively. Furthermore, the tetraploid-heterozygous zebrafish produced reduced-diploid gametes and yielded all-triploid or all-tetraploid offspring when crossed with wild-type (WT) or tetraploid zebrafish, respectively. Collectively, our findings provide direct evidence supporting the crucial role of meiotic crossover defects in the process of polyploidization. This is particularly evident in the generation of unreduced eggs in fish and, potentially, other vertebrate species.

Microfluidic paper-based analysis device applying black phosphorus nanosheets@MWCNTs-COOH: A portable and efficient strategy for detection of ß-Lactoglobulin in dairy products.

This study prepared a novel, portable and cost-effective microfluidic paper-based electrochemical analysis device (µ-PAD) using black phosphorus nanosheets@carboxylated multi-walled carbon nanotubes (BPNSs@MWCNTs-COOH) nanocomposites for ß-lactoglobulin (ß-LG) detection. At the appreciate ratio, the synthesized BPNSs@MWCNTs-COOH was demonstrated to not only serve as a high-quality substrate for the specific aptamer immobilization, but also improve the electron transfer capability of the sensing interface. The µ-PADs, utilizing BPNSs@MWCNTs-COOH and aptamer recognition, exhibited a wider detection range (10-1000 ng mL-1) and lower detection limit (LOD: 0.12 ng mL-1) for ß-LG, and demonstrated enhanced specificity, satisfactory anti-interference ability and stability. When applied to the ß-LG determination in dairy samples, the µ-PAD yielded ß-LG concentrations highly correlated with those obtained using the HPLC method (R2: 0.9982). These results emphasized the reliable performance of the developed µ-PADs in ß-LG allergen quantification, highlighting their potential as an efficient platform for the rapid screening of ß-LG allergens.

Efficient monodisperse upconversion composite prepared using high-density local field and its dual-mode temperature sensing.

Enhanced upconversion via plasmonics has considerable potential in biosensors and solar cells; however, conventional plasmonic configurations such as core-shell assemblies or nanoarray platforms still suffer from the compromise between the enhancement factor and monodispersity, which has failed to meet the requirement of the materials for the in vivo all-solution-prepared solar cells and biosensors. We herein report a monodisperse metal-dielectric-metal (MDM) type upconverted hybrid material with high efficiency. The lanthanide-doped upconversion nanoparticles (UCNPs) were sandwiched by two gold nanodisk mirrors, and the highly localized excitation field around the UCNPs together with the efficient coupling enhanced the upconversion. The upconversion intensity can then be effectively regulated and improved by three to four orders of magnitude. As per the measurement of the temperature-dependent fluorescence intensity and spectra shift, a dual-mode nanothermometer based on our proposed hybrid materials was demonstrated. This MDM-type upconverted hybrid material demonstrated the merits of high efficiency and monodispersity, which demonstrated promise in in vivo biosensors and solar cell fabrication techniques such as spin-coating and roll-to-roll.

Bimetallic Ag/Au nanoclusters encapsulated in ZIF-8 framework: A novel strategy for ratiometric fluorescence detection of doxycycline in food.

This study successfully encapsulated the Ag+-doped Au nanoclusters (Ag/AuNCs) within the ZIF-8 framework to construct a novel Ag/AuNCs@ZIF-8 ratiometric fluorescent probe for the antibiotic doxycycline (DOX) detection. The incorporation of Ag+ contributed to the fluorescence enhancement of the nanoclusters through the "silver effect", consequently improving the stability of the developed bimetallic Ag/AuNCs. Furthermore, the encapsulation of bimetallic Ag/AuNCs within the ZIF-8 framework restricted their intramolecular vibrations, resulting in further amplification of fluorescence intensity at 595 nm. The ZIF-8 also sensitized the restoration of DOX green fluorescence at 515 nm. Within the concentration range of 0.001-20 µg mL-1, the ratio of fluorescence intensity (F515/F595) exhibited a favorable linearity for DOX concentration, with a detection limit of 36.8 ng mL-1. This ratiometric fluorescence approach had the promising potential for accurate and efficient quantitative detection of DOX residue in food and served as a valuable reference for rapid monitoring of food contaminants.

Longitudinal Lower Airway Microbial Signatures of Acute Cellular Rejection in Lung Transplantation.

Rationale: Acute cellular rejection (ACR) after lung transplantation is a leading risk factor for chronic lung allograft dysfunction. Prior studies have demonstrated dynamic microbial changes occurring within the allograft and gut that influence local adaptive and innate immune responses. However, the lung microbiome's overall impact on ACR risk remains poorly understood. Objective: To evaluate whether temporal changes in microbial signatures were associated with the development of ACR. Methods: We performed cross-sectional and longitudinal analyses (joint modeling of longitudinal and time-to-event data and trajectory comparisons) of 16S rRNA gene sequencing results derived from lung transplant recipient lower airway samples collected at multiple timepoints. Measurements and Main Results: Among 103 lung transplant recipients, 25 (24.3%) developed ACR. In comparing samples acquired one month after transplant, subjects who never developed ACR demonstrated lower airway enrichment with several oral commensals (e.g., Prevotella and Veillonella spp.) compared to those with current or future (beyond one month) ACR. However, a subgroup analysis of those who developed ACR beyond one month revealed delayed enrichment with oral commensals occurring at the time of ACR diagnosis compared to baseline, when enrichment with more traditionally pathogenic taxa was present. In longitudinal models, dynamic changes in alpha diversity (characterized by an initial decrease and a subsequent increase) and in the taxonomic trajectories of numerous oral commensals were more commonly observed in subjects with ACR. Conclusion: Dynamic changes in the lower airway microbiota are associated with the development of ACR, supporting its potential role as a useful biomarker or in ACR pathogenesis.

Characteristics of Gastroenteritis Outbreaks Investigated in Singapore: 2018-2021.

There is a need to study the characteristics of outbreaks via Singapore's outbreak surveillance system to understand and identify the gaps in food safety for targeted policy interventions due to the increasing trend in gastroenteritis outbreaks and consequential increase in foodborne-related deaths and economic burden on public health systems worldwide. A total of 171 gastroenteritis outbreaks were investigated in Singapore from January 2018 to December 2021. This study analyzed the annual trend of investigated gastroenteritis outbreaks, the proportion of outbreaks by implicated sources of food, and the proportion of the type of pathogens identified from human cases, food samples, and environmental swabs collected from outbreak investigations. Among the foodborne gastroenteritis outbreaks (n = 121) investigated in Singapore, approximately 42.1% of the outbreaks had food prepared by caterers, 14.9% by restaurants, and 12.4% had food prepared by in-house kitchens. Clostridium perfringens and Salmonella were the most common causative pathogens in foodborne outbreaks throughout the analysis period. The food samples and environmental swabs collected were mostly detected for Bacillus cereus. Norovirus was the most common causative pathogen in non-foodborne outbreaks and was mainly attributable to preschools. This highlights the importance of monitoring and educating the catering industry and preschools to prevent future outbreaks.