Effect of Water on Phenol Separation from Model Oil with Ionic Liquids Based on COSMO-RS Calculation and Experimental Study

Ionic liquids (ILs) are widely used in the extraction of phenolic compounds from low-temperature coal tar (LTCT). However, both ILs and LTCT contain a certain amount of water. The existence of water may have a remarkable impact on the phenol separation performance of ILs with different structures. In this work, the capacity and selectivity for m-cresol, as well as the solubility of cumene and dodecane in different IL–H2O mixtures, were firstly calculated by the conductor-like screening model for real solvents (COSMO-RS) at infinite dilution. The calculation covers ILs with different anionic and anionic structures and different water contents. To explore the effect of water in IL on separation performance, 1-ethyl-3-methyl imidazolium acetate ([C2mim]­[Ac]) was selected as the representative IL, and then the molecular interactions between the [C2mim]­[Ac]–H2O mixture solvent and solute (including m-cresol, cumene, and dodecane) were analyzed by COSMO-RS. The results indicated that both water and m-cresol could form hydrogen bonds with [C2mim]­[Ac]. The competition between them leads to decreasing separation performance for m-cresol of the [C2mim]­[Ac]–H2O mixture with increasing water content. Moreover, through analyses of m-cresol extraction efficiency, distribution coefficient, selectivity, and entrainment of cumene and dodecane, the experimental results confirmed that the presence of water in [C2mim]­[Ac] had a negative effect on the separation of m-cresol. The viscosity and UV–vis spectra of the [C2mim]­[Ac]–H2O mixture were also measured. Water in ILs should be removed as much as possible to ensure a better dephenolization effect and avoid phenol containing wastewater

Clinical characteristics for conservative therapy of pediatric parapharyngeal abscesses

Abstract Introduction The role of surgical drainage versus conservative therapy in treating patients with parapharyngeal abscesses is still a theme of debate. Objectives This study aimed to investigate the characteristics associated with good outcomes in pediatric patients with parapharyngeal abscesses treated with conservative therapy. Methods This retrospective chart review was performed on children aged 0.3-14 years with the diagnosis of parapharyngeal abscesses confirmed by computed tomography from January 2013 to March 2018. Patients with a severe upper airway obstruction required early intervention, while those in a stable condition initially received conservative therapy with antibiotics. If the patients appeared unlikely to recover, additional surgical drainage was provided. Multivariate logistic regression models were constructed to investigate the clinical characteristics associated with a good response to conservative therapy. A receiver operating characteristic curve was used to identify the age and abscess size cutoff for predicting a successful response. Results A total of 48 children were included in the study. Patient age, antecedent illness, and abscess size were significantly associated with a response to therapy (Odds Ratio = 1.326, 2.314 and 1.235, respectively). The age cutoff associated with the conservative therapy was 4.2 years (76.9% sensitivity, 68.2% specificity), and the abscess size cutoff associated with the conservative therapy was 23 mm (84.6% sensitivity, 77.3% specificity). Conclusion The findings suggested that younger age, smaller abscess size, and less frequent antecedent illnesses, such as upper respiratory tract infection and lymphadenitis, could predict a successful response to conservative therapy in pediatric patients with parapharyngeal abscesses.</div

Converting a Binding Protein into a Biosensing Conformational Switch Using Protein Fragment Exchange

Biosensors can be used in applications ranging from identifying disease biomarkers to detecting spatial and temporal distributions of specific molecules in living cells. A major challenge facing biosensor development is how to functionally couple a biological recognition domain to an output module so that the binding event can be transduced to a visible and quantifiable signal [e.g., Förster resonance energy transfer (FRET)]. Most designs achieve coupling by means of a binding protein that changes conformation upon interacting with its target. This approach is limited by the fact that few proteins possess such natural allosteric mechanisms, and for those that do, the conformational change is frequently not extensive enough to produce a large change in distance between FRET donor and acceptor groups. Here, we introduce protein fragment exchange (FREX) to address both problems. FREX employs two components: a folded binding protein and a fragment duplicated from it, the latter of which can be chosen from many possible fragments. The system is rationally tuned so that addition of ligand induces a conformational change in which the fragment exchanges positions with the corresponding segment of the binding protein. Placing fluorescent donor and acceptor groups on the binding protein and fragment reduces the background level of FRET of the unbound sensor, resulting in a ratiometric FRET response that is expected to be strong and reproducible from protein to protein. FREX is demonstrated using fibronectin III, a monobody binding scaffold that has been tailored to recognize multiple targets. Sensors labeled with Alexa FRET pairs exhibit ratiometric FRET changes of up to 8.6-fold and perform equally well in buffer and serum. A genetically encoded variant of this sensor is shown to be functional in cell lysates and in mammalian cell cultures

sj-pdf-1-ijd-10.1177_10567895241247324 - Supplemental material for Investigation of pore structure evolution and damage characteristics of high temperature rocks subjected to liquid nitrogen cooling shock

Supplemental material, sj-pdf-1-ijd-10.1177_10567895241247324 for Investigation of pore structure evolution and damage characteristics of high temperature rocks subjected to liquid nitrogen cooling shock by Can Du, Jing Bi, Yu Zhao, Chaolin Wang, Wei Tang and Shuailong Lian in International Journal of Damage Mechanics</p

Multiple Isothermal Amplification Coupled with CRISPR–Cas14a for the Naked-eye and Colorimetric Detection of Aflatoxin B1

Aflatoxin B1 (AFB1) is highly toxic and challenging to remove, posing significant risks to both human health and economic development. Therefore, there is an urgent need to develop rapid, simple, and sensitive detection technologies. In this study, we introduce a naked-eye and colorimetric method based on multiple isothermal amplifications coupled with CRISPR–Cas14a and investigate its biosensing properties. This technique utilizes composite nanoprobes (MAPs) comprising magnetic nanoparticles and gold nanoparticles. AFB1 is efficiently identified through an aptamer competition process facilitated by magnetic nanoparticles , which triggers multiple isothermal amplification. This converts trace amounts of the toxin into a large quantity of DNA signal. Upon specific activation of the CRISPR–Cas14a complex, the MAPs are cleaved, resulting in significant changes in both color and colorimetric signal. The method demonstrates acceptable sensitivity, with a detection limit of 31.90 pg mL–1 and a wide detection range from 0.05 to 10 ng mL–1. Furthermore, the assay exhibits satisfactory specificity and high accuracy when it is applied to practical samples. Our approach offers a universal sensing platform with potential applications in food safety, environmental monitoring, and clinical diagnostics

sj-pdf-2-ijd-10.1177_10567895241247324 - Supplemental material for Investigation of pore structure evolution and damage characteristics of high temperature rocks subjected to liquid nitrogen cooling shock

Supplemental material, sj-pdf-2-ijd-10.1177_10567895241247324 for Investigation of pore structure evolution and damage characteristics of high temperature rocks subjected to liquid nitrogen cooling shock by Can Du, Jing Bi, Yu Zhao, Chaolin Wang, Wei Tang and Shuailong Lian in International Journal of Damage Mechanics</p

Table_1_Prevalence and WGS-based characteristics of MRSA isolates in hospitals in Shanghai, China.XLS

Methicillin-resistant Staphylococcus aureus (MRSA) isolates remain a serious threat to global health despite a decrease in MRSA infections since 2005. MRSA isolates exhibit great diversity worldwide, and their lineages show geographic variation. In this study, we used whole genome sequencing (WGS) to analyze antibiotic resistance genes and virulence genes, spa, staphylococcal cassette chromosome mec, sequence types (STs), and core genome multilocus sequence typing (cgMLST) of MRSA isolates from patients and environmental surface in hospitals in China to determine their prevalence and molecular traits. The highest number of infections by MRSA isolates was observed in patients aged ≥60 years (69.8%, P < 0.05). We identified a total of 19 STs from 162 MRSA isolates from patients. A significant increase was observed in the incidence of ST764-t002-II MRSA infection, which is replacing ST5-t002-II MRSA as the predominant ST. Similarly, isolates from environmental surface were predominantly ST764-t002-II (47%). Notably, most ST764 isolates (97.7%) carried seb, but not arginine catabolic mobile element (ACME), which differed from ST764 isolates in Japan and Thailand. The potential danger of spreading requires rigorous surveillance of emerging ST764 MRSA isolates. We also found higher resistance to seven antimicrobials [OXA, cefoxitin (FOX), ERY, CFZ, ciprofloxacin (CIP), levofloxacin (LEV), and moxifloxacin (MXF)]. Resistance to gentamicin (38.3%), tetracycline (55.9%), and minocycline (41.5%) were also common. Phenotypic resistance to antimicrobials was associated with resistance genes to its content, and cgMLST clustering suggested a strong link between these strains. Overall, our findings revealed the prevalence and molecular characteristics of MRSA isolates in Shanghai, China, providing a theoretical reference for preventing and controlling clonal transmission of MRSA isolates in hospitals in China.</p

DataSheet_1_Whole Genome Sequencing Identifies Novel Mutations Associated With Bedaquiline Resistance in Mycobacterium tuberculosis.pdf

Bedaquiline (BDQ), a new antitubercular agent, has been used to treat drug-resistant tuberculosis (TB). Although mutations in atpE, rv0678, and pepQ confer major resistance to BDQ, the mechanisms of resistance to BDQ in vitro and in clinical settings have not been fully elucidated. We selected BDQ-resistant mutants from 7H10 agar plates containing 0.5 mg/L BDQ (the critical concentration) and identified mutations associated with BDQ resistance through whole genome sequencing and Sanger sequencing. A total of 1,025 mutants were resistant to BDQ. We randomly selected 168 mutants for further analysis and discovered that 157/168 BDQ-resistant mutants harbored mutations in rv0678, which encodes a transcriptional regulator that represses the expression of the efflux pump, MmpS5–MmpL5. Moreover, we found two mutations with high frequency in rv0678 at nucleotide positions 286–287 (CG286–287 insertion; accounting for 26.8% [45/168]) and 198–199 (G198, G199 insertion, and G198 deletion; accounting for 14.3% [24/168]). The other mutations were dispersed covering the entire rv0678 gene. Moreover, we found that one new gene, glpK, harbors a G572 insertion; this mutation has a high prevalence (85.7%; 144/168) in the isolated mutants, and the minimum inhibitory concentration (MIC) assay demonstrated that it is closely associated with BDQ resistance. In summary, we characterized 168/1,025 mutants resistant to BDQ and found that mutations in rv0678 confer the primary mechanism of BDQ resistance. Moreover, we identified a new gene (glpK) involved in BDQ resistance. Our study offers new insights and valuable information that will contribute to rapid identification of BDQ-resistant isolates in clinical settings.</p

Additional file 1 of Contribution of small airway inflammation to the development of COPD

Supplementary Material

Acetylation of lysine 182 inhibits the ability of <i>Mycobacterium tuberculosis</i> DosR to bind DNA and regulate gene expression during hypoxia

The DosR regulon is believed to be a key factor in latency adaptation of Mycobacterium tuberculosis and is strongly induced by multiple stresses, including hypoxia. Previous studies have revealed reversible acetylation of the conserved core DNA-binding lysine residue 182 (K182) of DosR in M. tuberculosis. In this study, we demonstrated that acetylated K182 plays an important role in the DNA-binding ability of DosR and that acetylation of K182 completely abolished the affinity of DosR for DNA in vitro. Antibodies that specifically recognized acetyllysine at position 182 of DosR were used to monitor DosR acetylation. We found that in vitro acetylation of K182 could be removed by deacetylase Rv1151c and that either the deacetylase-deletion strain ∆npdA or treatment with a deacetylase inhibitor resulted in increased levels of K182 acetylation in vivo. The physiological significance of DosR acetylation was demonstrated by decreased levels of acetylated K182 in M. tuberculosis in response to hypoxia and by the effects of K182 acetylation on the transcript levels of DosR regulon genes. Since the DosR regulon plays a critical role during host infection by M. tuberculosis, our findings suggest that targeting DosR acetylation may be a viable strategy for antituberculosis drug development.</p