Risk factors for cardio-cerebrovascular events among patients undergoing continuous ambulatory peritoneal dialysis and their association with serum magnesium

Serum magnesium levels exceeding 0.9 mmol/L are associated with increased survival rates in patients with CKD. This retrospective study aimed to identify risk factors for cardio-cerebrovascular events among patients receiving continuous ambulatory peritoneal dialysis (CAPD) and to examine their correlations with serum magnesium levels. Sociodemographic data, clinical physiological and biochemical indexes, and cardio-cerebrovascular event data were collected from 189 patients undergoing CAPD. Risk factors associated with cardio-cerebrovascular events were identified by univariate binary logistic regression analysis. Correlations between the risk factors and serum magnesium levels were determined by correlation analysis. Univariate regression analysis identified age, C-reactive protein (CRP), red cell volume distribution width standard deviation, red cell volume distribution width corpuscular volume, serum albumin, serum potassium, serum sodium, serum chlorine, serum magnesium, and serum uric acid as risk factors for cardio-cerebrovascular events. Among them, serum magnesium ≤0.8 mmol/L had the highest odds ratio (3.996). Multivariate regression analysis revealed that serum magnesium was an independent risk factor, while serum UA (<440 μmol/L) was an independent protective factor for cardio-cerebrovascular events. The incidence of cardio-cerebrovascular events differed significantly among patients with different grades of serum magnesium (χ2 = 12.023, p = 0.002), with the highest incidence observed in patients with a serum magnesium concentration <0.8 mmol/L. High serum magnesium levels were correlated with high levels of serum albumin (r = 0.399, p < 0.001), serum potassium (r = 0.423, p < 0.001), and serum uric acid (r = 0.411, p < 0.001), and low levels of CRP (r = -0.279, p < 0.001). In conclusion, low serum magnesium may predict cardio-cerebrovascular events in patients receiving CAPD.

Inactivation of hydrogenase-3 leads to enhancement of 1,3-propanediol and 2,3-butanediol production by Klebsiella pneumoniae

Klebsiella pneumoniae can use glucose or glycerol as carbon sources to produce 1,3-propanediol or 2,3-butanediol, respectively. In the metabolism of Klebsiella pneumoniae, hydrogenase-3 is responsible for H2 production from formic acid, but it is not directly related to the synthesis pathways for 1,3-propanediol and 2,3-butanediol. In the first part of this research, hycEFG, which encodes subunits of the enzyme hydrogenase-3, was knocked out, so K. pneumoniae ΔhycEFG lost the ability to produce H2 during cultivation using glycerol as a carbon source. As a consequence, the concentration of 1,3-propanediol increased and the substrate (glycerol) conversion ratio reached 0.587 mol/mol. Then, K. pneumoniae ΔldhAΔhycEFG was constructed to erase lactic acid synthesis which led to the further increase of 1,3-propanediol concentration. A substrate (glycerol) conversion ratio of 0.628 mol/mol in batch conditions was achieved, which was higher compared to the wild type strain (0.545 mol/mol). Furthermore, since adhE encodes an alcohol dehydrogenase that catalyzes ethanol production from acetaldehyde, K. pneumoniae ΔldhAΔadhEΔhycEFG was constructed to prevent ethanol production. Contrary to expectations, this did not lead to a further increase, but to a decrease in 1,3-propanediol production. In the second part of this research, glucose was used as the carbon source to produce 2,3-butanediol. Knocking out hycEFG had distinct positive effect on 2,3-butanediol production. Especially in K. pneumoniae ΔldhAΔadhEΔhycEFG, a substrate (glucose) conversion ratio of 0.730 mol/mol was reached, which is higher compared to wild type strain (0.504 mol/mol). This work suggests that the inactivation of hydrogenase-3 may have a global effect on the metabolic regulation of K. pneumoniae, leading to the improvement of the production of two industrially important bulk chemicals, 1,3-propanediol and 2,3-butanediol.

Hydrogen-bond-modulated negative linear compressibility in a V-shaped molecular crystal

A material with the "hidden" negative linear compressibility (NLC) will expand along a specific crystal direction upon uniformly compression to a critical pressure; such materials are thought to be promising candidates for non-linear actuators, switches and sensors. Herein, we use density functional theory (DFT) calculations to uncover the hidden NLC in a V-shaped molecular crystal, bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM). The calculations indicate that the crystal is normally compressed over the pressure range of 0-3 GPa while it expands along the b-axis when the external hydrostatic pressure exceeds 3 GPa. The compressive behavior of the BATZM crystal is modulated by inter-molecular hydrogen bonds, which act as highly compressible springs at low pressures but robust struts at high pressures. Hence, the crystal prefers to compress the hydrogen bonds coupled with PLC at first and flatten the molecules, coupled with later NLC to resist the increasing external pressure. The compressive behavior of BATZM provides a strategy to design more hidden NLC materials via the rational use of the hydrogen bonds.

XMECP: Reaching State-of-the-Art MECP Optimization in Multiscale Complex Systems

The Python-based program, XMECP, is developed for realizing robust, efficient, and state-of-the-art minimum energy crossing point (MECP) optimization in multiscale complex systems. This article introduces the basic capabilities of the XMECP program by theoretically investigating the MECP mechanism of several example systems including (1) the photosensitization mechanism of benzophenone, (2) photoinduced proton-coupled electron transfer in the cytosine-guanine base pair in DNA, (3) the spin-flip process in oxygen activation catalyzed by an iron-containing 2-oxoglutarate-dependent oxygenase (Fe/2OGX), and (4) the photochemical pathway of flavoprotein adjusted by the intensity of an external electric field. MECPs related to multistate reaction and multistate reactivity in large-scale complex biochemical systems can be well-treated by workflows suggested by the XMECP program. The branching plane updating the MECP optimization algorithm is strongly recommended as it provides derivative coupling vector (DCV) with explicit calculation and can equivalently evaluate contributions from non-QM residues to DCV, which can be nonadiabatic coupling or spin-orbit coupling in different cases. In the discussed QM/MM examples, we also found that the influence on the QM region by DCV can occur through noncovalent interactions and decay with distance. In the example of DNA base pairs, the nonadiabatic coupling occurs across the π-π stacking structure formed in the double-helix system. In contrast to general intuition, in the example of Fe/2OGX, the central ferrous and oxygen part contribute little to the spin-orbit coupling; however, a nearby arginine residue, which is treated by molecular mechanics in the QM/MM method, contributes significantly via two hydrogen bonds formed with α-ketoglutarate (α-KG). This indicates that the arginine residue plays a significant role in oxygen activation, driving the initial triplet state toward the productive quintet state, which is more than the previous knowledge that the arginine residue can bind α-KG at the reaction site by hydrogen bonds.

Disulfidptosis decoded: a journey through cell death mysteries, regulatory networks, disease paradigms and future directions

Cell death is an important part of the life cycle, serving as a foundation for both the orderly development and the maintenance of physiological equilibrium within organisms. This process is fundamental, as it eliminates senescent, impaired, or aberrant cells while also promoting tissue regeneration and immunological responses. A novel paradigm of programmed cell death, known as disulfidptosis, has recently emerged in the scientific circle. Disulfidptosis is defined as the accumulation of cystine by cancer cells with high expression of the solute carrier family 7 member 11 (SLC7A11) during glucose starvation. This accumulation causes extensive disulfide linkages between F-actins, resulting in their contraction and subsequent detachment from the cellular membrane, triggering cellular death. The RAC1-WRC axis is involved in this phenomenon. Disulfidptosis sparked growing interest due to its potential applications in a variety of pathologies, particularly oncology, neurodegenerative disorders, and metabolic anomalies. Nonetheless, the complexities of its regulatory pathways remain elusive, and its precise molecular targets have yet to be definitively identified. This manuscript aims to meticulously dissect the historical evolution, molecular underpinnings, regulatory frameworks, and potential implications of disulfidptosis in various disease contexts, illuminating its promise as a groundbreaking therapeutic pathway and target.

Galvanic replacement synthesis of PtPdAu hollow nanorods as peroxidase mimic with high specific activity for colorimetric detection

Noble metal nanomaterials have been widely demonstrated to possess intrinsic enzyme-like properties and have been increasingly applied in the fields of analysis and biomedicine. However, current exploration of high-activity noble metal nanozymes is still far from adequate. The construction of hollow structures and adjustment of their elemental composition are effective ways to improve the specific activity (SA) of nanozymes. In this study, trimetallic PtPdAu hollow nanorods (HNRs) were developed using a galvanic replacement reaction and Kirkendall effect. The catalytic experiment showed that the PtPdAu HNRs possessed outstanding peroxidase-like performance and their SA value was up to 563.71 U mg-1, which is remarkable among various previously reported nanozymes and higher than that of monometallic or bimetallic counterparts with similar structure and size prepared in this study. Electron paramagnetic resonance (EPR)measurements showed that the PtPdAu HNRs could contribute to the formation of hydroxyl radicals (˙OH) in catalyzing hydrogen peroxide. When using PtPdAu HNRs as a nanozyme in the colorimetric detection of H2O2 and ascorbic acid (AA), the limits of detection were as low as 1.8 μM and 0.068 μM, respectively. This study demonstrates that PtPdAu HNRs are high-activity nanozymes and have the potential to be applied in the field of analysis.

Advanced Soft Porous Organic Crystal with Multiple Gas-Induced Single-Crystal-to-Single-Crystal Transformations for Highly Selective Separation of Propylene and Propane

Soft porous organic crystals with stimuli-responsive single-crystal-to-single-crystal (SCSC) transformations are important tools for unraveling their structural transformations at the molecular level, which is of crucial importance for the rapid development of stimuli-responsive systems. Carefully balancing the crystallinity and flexibility of materials is the prerequisite to construct advanced organic crystals with SCSC, which remains challenging. Herein, a squaraine-based soft porous organic crystal (SPOC-SQ) with multiple gas-induced SCSC transformations and temperature-regulated gate-opening adsorption of various C1-C3 hydrocarbons is reported. SPOC-SQ is featured with both crystallinity and flexibility, which enable pertaining the single crystallinity of the purely organic framework during accommodating gas molecules and directly unveiling gas-framework interplays by SCXRD technique. Thanks to the excellent softness of SPOC-SQ crystals, multiple metastable single crystals are obtained after gas removals, which demonstrates a molecular-scale shape-memory effect. Benefiting from the single crystallinity, the molecule-level structural evolutions of the SPOC-SQ crystal framework during gas departure are uncovered. With the unique temperature-dependent gate-opening structural transformations, SPOC-SQ exhibits distinctly different absorption behaviors towards C3 H6 and C3 H8 , and highly efficient and selective separation of C3 H6 /C3 H8 (v/v, 50/50) is achieved at 273 K. Such advanced soft porous organic crystals are of both theoretical values and practical implications.

Epigenetic regulation and factors that influence the effect of iPSCs-derived neural stem/progenitor cells (NS/PCs) in the treatment of spinal cord injury

Spinal cord injury (SCI) is a severe neurological disorder that causes neurological impairment and disability. Neural stem/progenitor cells (NS/PCs) derived from induced pluripotent stem cells (iPSCs) represent a promising cell therapy strategy for spinal cord regeneration and repair. However, iPSC-derived NS/PCs face many challenges and issues in SCI therapy; one of the most significant challenges is epigenetic regulation and that factors that influence this mechanism. Epigenetics refers to the regulation of gene expression and function by DNA methylation, histone modification, and chromatin structure without changing the DNA sequence. Previous research has shown that epigenetics plays a crucial role in the generation, differentiation, and transplantation of iPSCs, and can influence the quality, safety, and outcome of transplanted cells. In this study, we review the effects of epigenetic regulation and various influencing factors on the role of iPSC-derived NS/PCs in SCI therapy at multiple levels, including epigenetic reprogramming, regulation, and the adaptation of iPSCs during generation, differentiation, and transplantation, as well as the impact of other therapeutic tools (e.g., drugs, electrical stimulation, and scaffolds) on the epigenetic status of transplanted cells. We summarize our main findings and insights in this field and identify future challenges and directions that need to be addressed and explored.

Enhanced supercapacitor performance of porous carbon through tuning maceral composition proportion of coal

Porous carbons (PCs) have been widely investigated as electrode materials for supercapacitors. However, during the preparation process, intense pore formation reactions result in an amorphous carbon structure, which limits the rate performance of the electrode material. Herein, coal is chosen as a carbon source and making use of different reaction characteristics of vitrinite and inertinite with a KOH activator, an interconnected porous structure carbon material with an abundant graphite microcrystalline structure is obtained; the organic relationships between the ratio of vitrinite and inertinite, carbonization conditions, material structure and capacity performance were researched. At the ratio of vitrinite to inertinite of 1 : 2, the sample shows a specific surface area of 2507 m2 g-1 and its ID1/IG is 1.31, which is lower than that of raw coal (1.36). Due to the synergistic effect of the pore structure and graphite microcrystals, PC-900-40 exhibits an improved specific capacitance of 229.40 F g-1 at a current density of 1.0 A g-1, and even at a high current density of 10.0 A g-1 it delivers a specific capacitance of 170.04 F g-1. The PC-900-40//PC-900-40 symmetrical capacitor retains 96% of its initial capacitance after 20 000 cycles.

Revealing Novel Genomic Insights and Therapeutic Targets for Juvenile Idiopathic Arthritis through Omics

BACKGROUND

The genetic architecture of juvenile idiopathic arthritis (JIA) remains only partially comprehended. There is a clear imperative for continued endeavors to uncover insights into the underlying causes of JIA.

METHODS

This study encompassed a comprehensive spectrum of endeavors, including conducting a JIA GWAS meta-analysis that incorporated data from 4,550 JIA cases and 18 446 controls. We employed in silico and genome-editing approaches to prioritize target genes. To investigate pleiotropic effects, we conducted phenome-wide association studies. Cell-type enrichment analyses were performed by integrating bulk and single-cell sequencing data. Finally, we delved into potential druggable targets for JIA.

RESULTS

Fourteen genome-wide significant non-HLA loci were identified including four novel loci, each exhibiting pleiotropic associations with other autoimmune diseases or musculoskeletal traits. We uncovered strong genetic correlation between JIA and bone mineral density (BMD) traits at 52 genomic regions, including three GWAS loci for JIA. Candidate genes with immune functions were captured by in silico analyses at each novel locus, with additional findings identified through our experimental approach. Cell-type enrichment analysis revealed 21 specific immune cell types crucial for affected organs in JIA, indicating their potential contribution to the disease. Finally, 24 known or candidate druggable target genes were prioritized.

CONCLUSIONS

Our identification of four novel JIA associated genes, CD247, RHOH, COLEC10 and IRF8, broadens novel potential drug repositioning opportunities. We established a new genetic link between COLEC10, TNFRSF11B and JIA/BMD. Additionally, the identification of RHOH underscores its role in positive thymocyte selection, thereby illuminating a critical facet of JIA's underlying biological mechanisms.

Syringaresinol promotes the recovery of spinal cord injury by inhibiting neuron apoptosis via activating the ubiquitination factor E4B/AKT Serine/Threonine kinase signal pathway

Spinal cord injury (SCI) is a serious traumatic disease with no effective treatment. This study aimed to explore the therapeutic effect of syringaresinol on SCI. First, the potential targets and associated signaling pathways of syringaresinol were predicted by bioinformatics analysis and molecular docking. Second, MTT was employed to evaluate cell proliferation rate, Western blot was performed to detect protein expression, RT-qPCR was conducted to detect mRNA expression levels, flow cytometry and 5-ethynyl-2'-deoxyuridine (EDU) staining were used to determine cell apoptosis, and immunofluorescence and immunohistochemistry were used to estimate the expression of RNA binding fox-1 homolog 3 and clipped caspase 3. Basso-Beattie-Bresnahan scores and inclined plate tests were conducted to analyze hindlimb locomotor function. Results showed that syringaresinol could inhibit the apoptosis of glutamate-treated SHSY5Y cells by upregulating the expression of ubiquitination factor E4B (UBE4B) and activating the AKT serine/threonine kinase (AKT) signaling pathway. This effect can be rescued by UBE4B knockdown or AKT pathway inhibition. Syringaresinol remarkably improved locomotor function and increased neuronal survival in SCI rats. Our results suggested that syringaresinol could promote locomotor functional recovery by reducing neuronal apoptosis by activating the UBE4B/AKT signaling pathway.

Lanthanium nitride LaN9 featuring azide units: the first metal nine-nitride as a high-energy-density material

High-pressure phase diagrams of the La-N binary system were systematically constructed using the CALYPSO method and first-principles calculations. In addition to the pressure-induced La-N compounds reported previously, we have uncovered a hitherto unknown LaN9 structure in Pm3̄ symmetry stabilized within a narrow pressure range of 20-24.5 GPa. Notably, LaN9 stands as the first thermodynamically stable metal nine-nitrogen compound, featuring centrosymmetric linear N3 anion units and an edge-sharing LaN12 icosahedron. Charge transfer between the La and N atoms plays a crucial role in facilitating structural stability. Furthermore, we identified a novel Cm phase for LaN8, which has a lower enthalpy compared to the previously reported phase. N atoms in Cm LaN8 are polymerized into infinite N∞ chains. Calculations demonstrate the potential recoverability of LaN9 and Cm LaN8 under atmospheric conditions while preserving their initial polynitrogen configuration. From the perspective of detonation pressure and detonation velocity, LaN9 and Cm LaN8 exhibit excellent explosive performance in comparison to TNT and HMX, with estimated energy densities of 0.9 and 1.54 kJ g-1, respectively, indicating their potential utility as high-energy-density materials.

SpSrtA-Catalyzed Isopeptide Ligation on Lysine Residues

Sortase-mediated ligation (SML) is widely used for protein bioconjugation. However, the sortase used in this strategy typically recognizes only the N-terminal oligoglycine, which is absent in most natural proteins. To broaden the spectrum of substrates compatible with SML, we focus on a novel sortase, sortase A from Streptococcus pneumoniae (SpSrtA), known for its expanded substrate specificity (N-terminal glycine, alanine, and serine). We present the first evidence showing that the reported SpSrtA mutant (SpSrtA*) can modify lysine residues in itself and other proteins. The modification sites of SpSrtA* were identified through LC-MS/MS analysis. Moreover, we discovered an optimal lysine-containing peptide tag by fusing it onto sfGFP, resulting in a labeling efficiency of 57%. Inspired by this, we applied the method to modify proteins on microorganism surfaces up to 13.5-fold. To enhance labeling efficiency, we fused the SpSrtA* onto a surface protein and achieved a 2.64-fold improvement. We further developed a high-throughput yeast display screening method for the directed evolution of SpSrtA*, achieving a 10-fold improvement in the labeling efficiency of this surface protein. Our study provides a novel strategy for modifying the lysine residues that will be a powerful addition to the protein bioconjugation toolbox.

2-Hydroxyisovalerate production by Klebsiella pneumoniae

2-Hydroxyisovalerate is a valuable chemical that can be used in the production of biodegradable polyesters. In nature, it was only produced at a very low level by Lactococcus lactis. 2-Ketoisovalerate is an intermediate metabolite of the branched-chain amino acid biosynthesis pathway, and Klebsiella pneumoniae ΔbudAΔldhA (Kp ΔbudAΔldhA) was a 2-ketoisovalerate producing strain. In this research, 2-hydroxyisovalerate was identified as a metabolite of Kp ΔbudAΔldhA, and its synthesis pathway was revealed. It was found that 2-ketoisovalerate and 2-hydroxyisovalerate were produced by Kp ΔbudA and Kp ΔbudAΔldhA, but not by Kp ΔbudAΔldhAΔilvD in which the 2-ketoisovalerate synthesis was blocked. budA, ldhA, and ilvD encode α-acetolactate decarboxylase, lactate dehydrogenase, and dihydroxy acid dehydratase, respectively. Thus, it was deduced that 2-hydroxyisovalerate was synthesized from 2-ketoisovalerate. Isoenzymes of ketopantoate reductase PanE, PanE2, and IlvC were suspected of being responsible for this reaction. Kinetic parameters of these enzymes were detected, and they all hold the 2-ketoisovalerate reductase activities. PanE and PanE2 use both NADH and NADPH as co-factors. While IlvC only uses NADH as a co-factor. Over-expression of panE, panE2, or ilvC in Kp ΔbudAΔldhA all enhanced the production of 2-hydroxyisovalerate. Accordingly, 2-hydroxyisovalerate levels were reduced by knocking out panE or panE2. In fed-batch fermentation, 14.41 g/L of 2-hydroxyisovalerate was produced by Kp ΔbudAΔldhA-panE, with a substrate conversion ratio of 0.13 g/g glucose.

Impact of different ANCA serotypes on the long-term outcome of ANCA-associated vasculitis patients

OBJECTIVES

To investigate the clinical features and long-term outcomes of Chinese anti-neutrophil cytoplasmic antibodies (ANCAs)-associated vasculitis (AAV) patients with different ANCA serotypes.

METHODS

Two hundred and twenty-four AAV patients from January 2010 to June 2021 were divided into myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA groups. Clinical and long-term outcomes were compared.

RESULTS

In this study, the average follow-up was 46.4 months (range 0.3-188.4 months). One hundred and seventy-seven (79.0%) patients were MPO-ANCA-positive and 47 were PR3-ANCA-positive; the mean age of MPO-ANCA positive patients at diagnosis was elder than that of PR3-ANCA positive patients (67.0 vs. 60.0 years, p = .004). Among PR3-ANCA-positive patients, ear, nose and throat symptoms were more common (p = .014). Between two ANCA serotypes, there were no differences in complement 3 (C3), Birmingham vasculitis activity score (BVAS), five-factor score (FFS) or other organ involvements. For all AAV patients, the overall survival rates at one, three and five years were 80.0%, 67.0% and 56.4%, respectively. The cumulative relapse-free rates of one, three and five years were 89.5%, 76.4% and 68.4%, respectively. The survival of AAV patients was unaffected by the ANCA serotype (p = .23). The ANCA serotype also had no effect on either disease relapse (p = .20) or remission rates (p = .10). In our study, PR3-ANCA patients showed a better long-term survival, as the 5-year survival rate and the 5-year relapse-free survival rate of PR3-ANCA patients were 60.7% and 76.9%, while that of MPO-ANCA patients were 55.2% and 65.8%, respectively. Rather than ANCA serotype, younger patients with milder kidney involvement and lower disease assessment scores (BVAS and FFS) might be more relevant to better prognosis.

CONCLUSIONS

The likelihood of induced remission, patient survival or disease recurrence is all unaffected by ANCA serotypes. A better prognosis is seen in younger patients with milder kidney involvement and lower BVAS/FFS scores.

An intelligent diagnostic method of ECG signal based on Markov transition field and a ResNet

BACKGROUND AND OBJECTIVE

Heart disease seriously threatens human life and health. It has the character of abruptness and is necessary to accurately monitor and intelligently diagnose electrocardiograph signals in real-time. As part of the automation of heart monitoring, the electrocardiogram (ECG) intelligent diagnosis method based on deep learning not only meets the needs of real-time and accurate but also can abandon relevant professional knowledge, which makes it possible to be promoted in the general population.

METHODS

This paper presents an intelligent diagnosis method based on a ResNet. Firstly, ECG signals from MIT-BIH Database are converted into 2-dim matrices by Markov Transition Field. Secondly, the matrices are used as the input of a ResNet. Then, the ResNet is able to extract high abstract features of various diseases and realize intelligent identification of five heartbeat types, including Normal Beat, Left Bundle Branch Block Beat, Right Bundle Branch Block Beat, Premature Ventricular Contraction Beat, and Atrial Premature Contraction Beat. Eventually, the proposed model is used to identify Normal Beat and Atrial Fibrillation(AF) based on the PAF Prediction Challenge Database(the PAFPC Database) to verify its generalization ability.

RESULTS

The experiment result shows that the intelligent diagnosis method can reach a high F1-score of 97.7% and a high accuracy upon to 99.2% on MIT-BIH Database, which are higher than the models proposed by other researchers. Its mean sensitivity and mean specificity are 97.42% and 99.54%, respectively. Moreover, the accuracy of the generalization ability verification experiment is 94.57% on the PAFPC Database, which is also higher than the results of other studies.

CONCLUSION

The research results show that the method proposed in this paper still achieves higher accuracy and higher F1-score than other methods without any data preprocessing. This method has better classification performance than traditional machine learning methods and other deep learning methods. That is, the method based on Markov Transition Field and a ResNet has good application prospects. At the same time, it has been verified that the model proposed in this paper also has excellent generalization ability.

Selective Oxidation of 5-Hydroxymethyl Furfural Coupled with H2 Production over Surface Sulfur Vacancy-Rich Zn3In2S6/Bi2MoO6 Heterojunction Photocatalyst

The construction of heterojunctions and surface defects is a promising strategy for enhancing photocatalytic activity. A surface sulfur vacancy (VS)-rich Zn3In2S6/Bi2MoO6 heterojunction photocatalyst (ZIS-VS/BMO) was herein developed for the selective oxidation of biomass-derived 5-hydroxymethyl furfural (HMF) to value-added 2,5-diformylfuran (DFF) coupled with H2 production. The ZIS-VS/BMO heterojunction consisted of Bi2MoO6 (BMO) with preferentially exposed high-index (131) facets and VS-rich two-dimensional (2D) Zn3In2S6 (ZIS-VS) nanosheets with preferentially exposed high-index (102) facets. The directional transfer of light-driven electrons from BMO to ZIS-VS occurs in the heterojunction interface, as confirmed by an in situ irradiated XPS (ISI-XPS) measurement, which facilitates the electron-hole separation. The benefits of VS in activating HMF, suppressing overoxidation of DFF, and accelerating electron transport were disclosed by molecular simulation. ZIS-VS/BMO displays outstanding performance with a DFF yield of 74.1% and a DFF selectivity of 90%, as well as a rapid rate of H2 evolution. This research would help design highly efficient photocatalysts and develop a new technology for biomass resource utilization.

[The predictive values of platelet mitochondrial mass and quantity during the perioperative period in elderly patients on the occurrence of postoperative delirium]

Objective: To investigate the changes of platelet mitochondrial mass and quantity during perioperative period in elderly patients, and assess their predictive values on the occurrence of postoperative delirium (POD). Methods: In this prospective study, 162 elderly patients scheduled for abdominal surgery under general anesthesia were enrolled from November 2021 to January 2022 in Nanjing Drum Tower Hospital Affiliated to Nanjing University Medical School. Among them, 20 patients [10 males, 10 females, aged (71.4±6.8) years] developed POD within 3 days after surgery (POD group), and another 20 patients[12 males, 8 females, aged (67.7±5.3) years] who did not develope POD were selected as controls (control group) using propensity score matching method. Blood samples were collected preoperatively, at the end of surgery and on the first postoperative day. Platelets were extracted and mitochondrial mass was detected with flow cytometry. Transmission electron microscopy was used to determine mitochondrial quantity. The receiver operating characteristic (ROC) curve was drawn to analyze the value of mitochondrial mass and quantity in predicting the occurrence of POD. Results: The mean fluorescence intensities of platelet mitochondrial mass were 193±46, 236±61, 264±53 preoperatively, at the end of surgery and on the first postoperative day in the POD group, respectively. The corresponding values were 209±61, 191±67 and 201±56 in the control group. The platelet mitochondrial mass of patients in the POD group was significantly increased on the first postoperative day compared to preoperative levels (P<0.001). In contrast, there was no significant difference in the control group (P=0.410). Patients in the POD group had higher platelet mitochondrial mass than patients in the control group on the first postoperative day(P=0.002). Meanwhile, platelets from patients in the POD group showed significantly higher number of mitochondria than platelets from patients in the control group [3 (2, 4) vs 2 (1, 2), P<0.001]. According to the ROC curve of platelet on the first postoperative day, at a mitochondrial mass cut-off value of>275.35, the sensitivity, specificity and area under the ROC curve to detect the occurrence of POD were 55%, 90% and 0.800 (95%CI: 0.666-0.934, P<0.001). At a mitochondrial quantity cut-off value of>2, the sensitivity, specificity and area under the ROC curve to detect the occurrence of POD were 53%, 78% and 0.680 (95%CI: 0.584-0.776, P<0.001). Conclusions: Patients who developed POD show higher platelet mitochondrial mass after surgery compared to preoperative levels. The mitochondrial mass of platelets on the first postoperative day has good predictive value on the occurrence of POD.

Unit-cell-thick zeolitic imidazolate framework films for membrane application

Zeolitic imidazolate frameworks (ZIFs) are a subset of metal-organic frameworks with more than 200 characterized crystalline and amorphous networks made of divalent transition metal centres (for example, Zn2+ and Co2+) linked by imidazolate linkers. ZIF thin films have been intensively pursued, motivated by the desire to prepare membranes for selective gas and liquid separations. To achieve membranes with high throughput, as in ångström-scale biological channels with nanometre-scale path lengths, ZIF films with the minimum possible thickness-down to just one unit cell-are highly desired. However, the state-of-the-art methods yield membranes where ZIF films have thickness exceeding 50 nm. Here we report a crystallization method from ultradilute precursor mixtures, which exploits registry with the underlying crystalline substrate, yielding (within minutes) crystalline ZIF films with thickness down to that of a single structural building unit (2 nm). The film crystallized on graphene has a rigid aperture made of a six-membered zinc imidazolate coordination ring, enabling high-permselective H2 separation performance. The method reported here will probably accelerate the development of two-dimensional metal-organic framework films for efficient membrane separation.

Selective Photonic Gasification of Strained Oxygen Clusters on Graphene for Tuning Pore Size in the Å Regime

Controlling the size of single-digit pores, such as those in graphene, with an Å resolution has been challenging due to the limited understanding of pore evolution at the atomic scale. The controlled oxidation of graphene has led to Å-scale pores; however, obtaining a fine control over pore evolution from the pore precursor (i.e., the oxygen cluster) is very attractive. Herein, we introduce a novel "control knob" for gasifying clusters to form pores. We show that the cluster evolves into a core/shell structure composed of an epoxy group surrounding an ether core in a bid to reduce the lattice strain at the cluster core. We then selectively gasified the strained core by exposing it to 3.2 eV of light at room temperature. This allowed for pore formation with improved control compared to thermal gasification. This is because, for the latter, cluster-cluster coalescence via thermally promoted epoxy diffusion cannot be ruled out. Using the oxidation temperature as a control knob, we were able to systematically increase the pore density while maintaining a narrow size distribution. This allowed us to increase H2 permeance as well as H2 selectivity. We further show that these pores could differentiate CH4 from N2, which is considered to be a challenging separation. Dedicated molecular dynamics simulations and potential of mean force calculations revealed that the free energy barrier for CH4 translocation through the pores was lower than that for N2. Overall, this study will inspire research on the controlled manipulation of clusters for improved precision in incorporating Å-scale pores in graphene.

Coupling of Nd doping and oxygen-rich vacancy in CoMoO4@NiMoO4 nanoflowers toward advanced supercapacitors and photocatalytic degradation

In this paper, we successfully prepared rare earth element-doped 0.8% Nd-CoMoO4@NiMoO4 nanoflowers with a large specific surface area using the sol-gel method for the first time. In the experiment, we added a structure-directing agent to successfully assemble the nanosheets into a three-dimensional ordered micro-flower shape. By using the strategy of forming a flower-shaped morphology with a structure-directing agent and doping Nd elements to generate oxygen vacancies, the problems of the collapse of the active material structure and slow reaction kinetics were solved. Through relevant electrochemical performance tests, it was found that when the rare earth element Nd was doped at a concentration of 0.8%, the material exhibited exceptional specific capacitance (2387 F g-1 at 1 A g-1) and cycling stability (99.3% after 10 000 cycles at 5 A g-1). These performance characteristics far surpassed those of the other synthesized products. We assembled 0.8% Nd-CoMoO4@NiMoO4 with hydrophilic CNTs into an asymmetric device, 0.8% Nd-CoMoO4@NiMoO4//CNTs. This device exhibited high specific capacitance (262 F g-1 at 1 A g-1) and cycling stability (99.2% after 3000 cycles), with a good energy storage effect. In addition, 0.8% Nd-CoMoO4@NiMoO4 has a low band gap, which broadens the absorption range of the product and improves the utilization rate of visible light. The photocatalyst showed good degradation efficiency (all exceeding 96%) and cycling stability (96%) for all four dyes. This paper provides a new strategy and method for preparing doped polymetallic mixtures, which has potential application value.

Sema3C Signaling is an Alternative Activator of the Canonical WNT Pathway in Glioblastoma

PURPOSE/OBJECTIVE(S)

Wnt signaling maintains normal and cancer stem cells. The Wnt pathway is frequently dysregulated in many cancers, underscoring it as a therapeutic target. Although Wnt inhibitors appear promising in many preclinical studies, they have failed uniformly in clinical trials. Molecular mechanisms of resistance are poorly defined. Further dissection of the precise mechanisms of Wnt pathway activation in specific tumor types is needed to develop new Wnt pathway inhibitors with less toxicity. Here, we identify an alternative activator of the Wnt pathway that may mediate resistance to upstream Wnt inhibition in glioblastoma.

MATERIALS/METHODS

Glioma stem-like cells (GSCs) were enriched in defined media. GSCs were transduced with lentiviruses to knockdown or overexpress Sema3C or Wnt pathway components. Cell viability, proliferation, apoptosis, and self-renewal were assessed. Expression of Sema3C and Wnt pathway components were assessed in GSCs, mouse models of GBM, and human glioblastoma by qPCR, Western blot, and/or immunostaining. Beta-catenin subcellular localization was assessed by cell fractionation and immunofluorescence. GSC-derived orthotopic models of GBM were used to assess the impact of genetic or pharmacologic inhibition of Sema3C or Wnt pathway components alone or in combination on tumor growth and animal survival.

RESULTS

The axonal guidance protein Sema3C promotes the tumorigenicity of GSCs through binding its NRP/PlxnD1 receptor complex leading to Rac1 activation. Sema3C signaling directs beta-catenin nuclear accumulation in a Rac1-dependent process, leading to transactivation of Wnt target genes. Sema3C-driven Wnt signaling occurred despite suppression of Wnt ligand secretion, suggesting that Sema3C may drive canonical Wnt signaling independent of Wnt ligand binding. In human glioblastoma, Sema3C expression and Wnt pathway activation were highly concordant. In a mouse model of glioblastoma, combined depletion of Sema3C and beta-catenin partner TCF1 extended animal survival more than single target inhibition alone.

CONCLUSION

Sema3C signaling may represent an alternative mechanism of WNT pathway activation even when WNT ligand-receptor interaction is inhibited. Since Sema3C is overexpressed in >85% glioblastoma and is used to maintain GSCs but not normal neural progenitor cells, this pathway may represent a major mechanism of Wnt pathway activation and resistance to upstream Wnt pathway inhibitors in GSCs. Our data provide a therapeutic strategy to achieve clinically significant Wnt pathway inhibition in GSCs potentially without the toxicity of currently available WNT inhibitors.

[Distribution and reference intervals of daytime intraocular pressure in the eye health screening population of Handan]

Objective: To describe the distribution and establish reference intervals (RI) of daytime intraocular pressure (IOP) in the eye health screening population of Handan. Methods: This cross-sectional study included subjects who participated in eye health screening at the Physical Examination Center of Handan First Hospital from May 2021 to June 2022. A complete general and ocular examination was performed, including measurements of visual acuity and IOP (using Goldmann tonometry), slit lamp microscopy, fundus photography, and anterior and posterior segment optical coherence tomography. Subjects with factors that could cause significant changes in IOP or affect the accuracy of IOP measurement, or with an inability to measure IOP were excluded. Simple random sampling was used to select participants, who were grouped by gender and age (18 to <30, 30 to <40, 40 to <50, 50 to <60, 60 to <70, and ≥70 years). Central corneal thickness and IOP at 8 to 11 o'clock in one eye of each participant were recorded. The independent sample t test and ANOVA were used for statistical analysis, and the RI of IOP values was calculated by x¯±1.96s. Results: A total of 9 310 subjects had their IOP measured, and 3 491 participants (3 491 eyes) were randomly selected from 7 886 healthy subjects. The age of the participants was (47.74±14.47) years old, ranging from 18 to 90 years old. There were 1 694 males and 1 797 females. The central corneal thickness of all participants was (525.56±49.39) μm. The daytime IOP of all participants was (15.40±2.54) mmHg (1 mmHg=0.133 kPa), and the RI was 10.42 to 20.39 mmHg. The IOP was (15.49±2.58) mmHg for males and (15.29±2.49) mmHg for females, and the gender difference was statistically significant (P<0.05). The RI of daytime IOP values was 10.43 to 20.54 mmHg for males and 10.41 to 20.18 mmHg for females. There were significant differences in daytime IOP [(15.13±2.58), (15.33±2.53), (15.49±2.50), (15.53±2.55), (15.39±2.62), and (15.28±2.52) mmHg] among 6 age groups (P<0.05). Conclusions: The distribution of daytime IOP in different gender and age groups in the eye health screening population of Handan and the RIs derived from the distribution were roughly the same as the international normal IOP RI (10 to 21 mmHg). It is recommended to refer to the RI of daytime IOP values of different genders and ages for clinical decision.

Prediction of a reservoir of N-rich high-energy density material at the Earth's mantle

Water and nitrogen are abundant in the Earth's interior and atmosphere, and their mixture under high pressure is a fundamental and valuable scientific issue for physics and chemical science. Based on structural prediction and first-principles simulations, we propose that the two nitrogen-rich stoichiometries, H₂ON₆ and H₂ON₁₀, become energetically stable above ∼70 GPa. Further ab initio molecular dynamics calculations indicate that H₂ON₆ and H₂ON₁₀ undergo phase transitions from solid to superionic and finally to fluid phase with increasing temperature. The superionic regions in their phase diagram correspond to the extreme conditions of Earth's mantle, implying that the Earth's interior might be a possible reservoir of the N-rich hydrates. In addition, H₂ON₆ remains dynamically stable under ambient conditions with an estimated energy density of 6.53 kJ g^-1, indicating that it might be a high-energy density material. These results not only provide essential information for the understanding of the Earth's interior, but also provide guidance for the design of high-energy density materials.

LncRNA CASC15 inhibition relieves renal fibrosis in diabetic nephropathy through down-regulating SP-A by sponging to miR-424

Study has demonstrated the abnormal expression and role of lncRNA CASC15 in diabetes patients with chronic renal failure. However, its role in diabetes nephropathy (DN) is still unclear. This study aimed to investigate the potential mechanism and role of lncRNA CASC15 in DN. The relationship between miR-424 and CASC15/SP-A was predicted by Starbase software and verified by luciferase reporter assay. HK-2 cells were treated with 25 mM glucose (HG) for 24 h to establish DN cell model. MTT and flow cytometry analysis were carried out to test cell proliferation and apoptosis. Epithelial-to-mesenchymal transition (EMT) markers were analyzed by RT-qPCR and western blot assay. We proved that CASC15 could interact with miR-424, and SP-A was a target of miR-424. HG-treatment significantly enhanced lncRNA CASC15 level and decreased miR-424 level in HK-2 cells. LncRNA CASC15-siRNA significantly improved cell viability, repressed apoptosis, promoted E-cadherin expression, and inhibited N-cadherin expression in HG-treated HK-2 cells, and these effects were reversed by miR-424 inhibitor. SP-A was highly expressed in HG-treated HK-2 cells. The biological effects of miR-424 mimic on HG-treated HK-2 cells were reversed by SP-A-plasmid. In conclusion, lncRNA CASC15 inhibition relieved HG-induced HK-2 cell injury and EMT through miR-424/SP-A axis.

Enhancement of oxygen sensing performance of metalloporphyrin film modified with nano Al2O3 powder

In this work, the metalloporphyrin film of PtOEP/Poly (St-co-TFEMA) modified by nano Al₂O₃ powder was prepared, and the enhancement performance of oxygen sensing was studied in detail. It was verified that the modified film extended the residence time of oxygen through the characterization of SEM. The phosphorescence intensity changes with the content of Al₂O₃ and PtOEP were studied. The Stern-Volmer equations before and after modification of Al₂O₃ powder was compared. It was found that the linearity of the calibration curve was still high, but the oxygen sensitivity value of K_SV was significantly improved due to the increase of quenching probability between indicator and oxygen. Finally, the stability test shows that the Al₂O₃@PtOEP/Poly (St-co-TFEMA) oxygen sensing film presents a strong anti-photo-bleaching ability, and the response time is shortened.

Neutrophil to high-density lipoprotein cholesterol ratio, a novel risk factor associated with acute ischemic stroke

To investigate the relationship between neutrophil to high-density lipoprotein cholesterol ratio (NHR) and Acute Ischemic Stroke (AIS), and provide a new direction for the diagnosis and prevention of AIS. A total of 158 patients with AIS and 162 healthy individuals were recruited. Demographic, clinical, and laboratory data of participants were obtained and the multivariable logistic regression analysis was employed to assess risk factors for AIS. The receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic value of NHR for AIS. The spearman correlation analysis was used to estimate the correlation between NHR and national institute of health stroke scale (NIHSS) score. The age, White blood cell, MONO (monocyte), NEUT (neutrophil), creatinine, TG (triglyceride), NHR, neutrophil to lymphocyte ratio and MONO to high-density lipoprotein cholesterol ratio were remarkably greater and HDL-C (high-density lipoprotein cholesterol) was dramatically lower in the case group compared with in the control group (P < .05). The multivariable logistic regression analysis revealed that age [OR = 1.095, 95% CI (1.056, 1.135)], TG [OR = 6.188, 95% CI (2.900, 13.206)] and NHR [OR = 11.394, 95% CI (1.196, 108.585)] were independent risk factors for AIS (P < .05). The areas under the curve (AUCs) for the prediction of AIS by the age, TG and NHR were 0.694, 0.686, 0.782, respectively, the specificity were 56.8%, 88.3%, 87.0%, and the sensitivity were 75.3%, 44.3%, 56.3%, respectively (P < .05). In addition, spearman correlation analysis indicated that there was a positive correlation between NHR and NIHSS score (R = 0.558, P < .05). The level of NHR was higher in patients with a NIHSS score of above 5 points compared with those with a NIHSS score of 5 points or lower (P < .0001). The age, TG, and NHR were independent risk factors for AIS, and the level of NHR was positively correlated with severity of AIS.

Silver-Promoted Radical Cascade Aryldifluoromethylation/Cyclization of 2-Allyloxybenzaldehydes for the Synthesis of 3-Aryldifluoromethyl-Containing Chroman-4-one Derivatives

A convenient silver-promoted radical cascade aryldifluoromethylation/cyclization of 2-allyloxybenzaldehydes has been developed. Experimental studies disclosed that the addition of aryldifluoromethyl radicals in situ produced from easily accessible gem-difluoroarylacetic acids to unactivated double bonds in 2-allyloxybenzaldehyde was an effective route to access a series of 3-aryldifluoromethyl-containing chroman-4-one derivatives in moderate to good yields under mild reaction conditions.

Superconducting H7 chain in gallium hydrides at high pressure

Pressure-stabilized hydrides have potential as an outstanding reservoir for high-temperature (T_c) superconductors. We undertook a systematic study of crystal structures and superconducting properties of gallium hydrides using an advanced structure-search method together with first-principles calculations. We identified an unconventional stoichiometric GaH₇ gallium hydride that is thermodynamically stable at pressures above 247 GPa. Interestingly, the H atoms are clustered to form a unique H₇ chain intercalating the Ga framework. Further calculations show a high estimated T_c above 100 K at 200-300 GPa for GaH₇, closely related to the strong coupling between electrons of Ga and H atoms, and phonon vibrations of H₇ chains. Our work provides an example of exploration for diverse superconducting hydrogen motifs under high pressure, and may stimulate further experimental syntheses.

Correlation analysis of systemic immune inflammatory index, Serum IL-35 and HMGB-1 with the severity and prognosis of sepsis

Objective

To investigate the correlation between systemic immune inflammatory (SII) index, serum interleukin-35 (IL-35) and high mobility Group-Box one (HMGB-1) with the severity and prognosis of sepsis.

Methods

A retrospective analysis was performed on the clinical data of 209 patients with sepsis admitted to Ganzhou City People's Hospital from October 2019 to October 2021. One hundred eighteen patients in Group-A had common sepsis, and 91 patients in Group-B had septic shock, which were subdivided into the survival Group-And the mortality Group-According to the 28d prognosis. The levels of SII, IL-35 and HMGB-1 in different groups were compared, and their correlation with the severity and prognosis of sepsis was analyzed.

Result

The levels of SII, IL-35 and HMGB-1 in Group-A were significantly lower than those in Group-B (p<0.05). The levels of SII, IL-35 and HMGB-1 in the survival group were significantly lower than those in the death group (p<0.05). Spearman correlation analysis showed that the levels of SII, IL-35, and HMGB-1 were significantly positively correlated with the severity of sepsis (p<0.05), and significantly positively correlated with the prognosis of patients with sepsis (p<0.05).

Conclusion

SII, IL-35 and HMGB-1 are remarkably correlated with the severity and prognosis of patients with sepsis. With the increasing in SII, IL-35 and HMGB-1 levels, patients will suffer from severe disease progression and poor prognosis, which require more clinical attention.

Characterization and applications of evoked responses during epidural electrical stimulation

BACKGROUND

Epidural electrical stimulation (EES) of the spinal cord has been FDA approved and used therapeutically for decades. However, there is still not a clear understanding of the local neural substrates and consequently the mechanism of action responsible for the therapeutic effects.

METHOD

Epidural spinal recordings (ESR) are collected from the electrodes placed in the epidural space. ESR contains multi-modality signal components such as the evoked neural response (due to tonic or BurstDR™ waveforms), evoked muscle response, stimulation artifact, and cardiac response. The tonic stimulation evoked compound action potential (ECAP) is one of the components in ESR and has been proposed recently to measure the accumulative local potentials from large populations of neuronal fibers during EES.

RESULT

Here, we first review and investigate the referencing strategies, as they apply to ECAP component in ESR in the domestic swine animal model. We then examine how ECAP component can be used to sense lead migration, an adverse outcome following lead placement that can reduce therapeutic efficacy. Lastly, we show and isolate concurrent activation of local back and leg muscles during EES, demonstrating that the ESR obtained from the recording contacts contain both ECAP and EMG components.

CONCLUSION

These findings may further guide the implementation of recording and reference contacts in an implantable EES system and provide preliminary evidence for the utility of ECAP component in ESR to detect lead migration. We expect these results to facilitate future development of EES methodology and implementation of use of different components in ESR to improve EES therapy.

Copper-Catalyzed Trifluoromethylation of (Hetero)aryl Boronic Acid Pinacol Esters with YlideFluor

A copper-catalyzed trifluoromethylation of (hetero)arylboronic acid pinacol esters with YlideFluor for the preparation of trifluoromethylated (hetero)arenes was described. The reaction conditions are mild and compatible with a broad range of functional groups. Heteroaryl boronic acid pinacol esters could also be trifluoromethylated in high yields. Application of this protocol for trifluoromethylation of drug and OLED molecules was demonstrated.

Low-grade sepiolite with low loading of Na/La salts for simultaneous removal of ammonia and phosphate from wastewater

Efficient treatment of wastewater is of paramount importance for protecting the ecosystem. In this work, we prepared a low-grade sepiolite with low Na/La salt loadings (Na/La-Sep) and employed it for the simultaneous removal of ammonia (N) and phosphate (P) species in the wastewater. The key factors influencing the nutrient removal efficiency of Na/La-Sep, such as the concentration of the La/Na salt solution, the co-existing ion type, and surface zero charges, were investigated. Na/La-Sep exhibits excellent N and P adsorption capability and reduced the N and P concentrations in the spiked and real-world wastewaters to below the allowable N and P discharge limits. Due to the extraordinarily low cost of low-grade sepiolite and the low loading of Na/La salts, Na/La-Sep has a substantially lower cost when compared to other reported clay mineral adsorbents. Furthermore, the N and P removal mechanisms by Na/La-Sep were unraveled by combining the kinetic studies, the molecular dynamics (MD) simulation, and the electron density difference. The present findings might shed light on a new way to develop cost-efficient and high-efficiency adsorbents for alleviating eutrophication and deepen the understanding of N and P removal at a molecular level.

Preparation of the Porous CoMoO4+NiMoO4 nanosheets with high capacitance by a Sol-gel method and freezing method

Cobalt molybdate and nickel molybdate blends were prepared by sol-gel method and freezing method. Through the correlation analysis of morphology and phase, the prepared product has a porous sheet structure,...

Multi-objective parameter optimization of CNC plane milling for sustainable manufacturing

Energy modeling and cutting parameter optimization of the machining process have been recognized as powerful and effective ways to save energy. However, in the actual machining process, technologists often use empirical methods to determine the final cutting parameters. Due to the lack of theoretical support and optimization tools, this method is difficult to fully consider the constraints of machine tool capability, cutting tool performance, and workpiece material, which affects the overall performance of the machine tool to give full play. To address this problem, a multi-objective parameter optimization method of computer numerical control (CNC) plane milling for sustainable manufacturing was proposed in this paper. More specifically, three tasks were carried out: (1) an accurate milling energy model considering transient processes such as spindle acceleration was established; (2) a multi-objective parameter optimization model of CNC plane milling was established with cutting parameters as optimization variables and considering various complex constraints; (3) by drawing 3D surface maps, the internal relationship between the cutting parameters and the optimization index was presented in detail and intuitively. Finally, a case study was carried out in the XHK-714F vertical machining center. The results showed that the processing efficiency is improved by 21.0%, the energy consumption is reduced by 15.3%, and the surface roughness is reduced by 5.5% through the optimization of cutting parameters, which verified the effectiveness and feasibility of the proposed model and method.

The pyruvate decarboxylase activity of IpdC is a limitation for isobutanol production by Klebsiella pneumoniae

Background

Klebsiella pneumoniae contains an endogenous isobutanol synthesis pathway. The ipdC gene annotated as an indole-3-pyruvate decarboxylase (Kp-IpdC), was identified to catalyze the formation of isobutyraldehyde from 2-ketoisovalerate.

Results

Compared with 2-ketoisovalerate decarboxylase from Lactococcus lactis (KivD), a decarboxylase commonly used in artificial isobutanol synthesis pathways, Kp-IpdC has an 2.8-fold lower K_m for 2-ketoisovalerate, leading to higher isobutanol production without induction. However, expression of ipdC by IPTG induction resulted in a low isobutanol titer. In vitro enzymatic reactions showed that Kp-IpdC exhibits promiscuous pyruvate decarboxylase activity, which adversely consume the available pyruvate precursor for isobutanol synthesis. To address this, we have engineered Kp-IpdC to reduce pyruvate decarboxylase activity. From computational modeling, we identified 10 amino acid residues surrounding the active site for mutagenesis. Ten designs consisting of eight single-point mutants and two double-point mutants were selected for exploration. Mutants L546W and T290L that showed only 5.1% and 22.1% of catalytic efficiency on pyruvate compared to Kp-IpdC, were then expressed in K. pneumoniae for in vivo testing. Isobutanol production by K. pneumoniae T290L was 25% higher than that of the control strain, and a final titer of 5.5 g/L isobutanol was obtained with a substrate conversion ratio of 0.16 mol/mol glucose.

Conclusions

This research provides a new way to improve the efficiency of the biological route of isobutanol production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13068-022-02144-8.

Kp-IpdC is more efficient than KivD for 2-ketoisovalerate decarboxylation.

Pyruvate decarboxylase activity is a limitation of Kp-IpdC.

T290L variant exhibits a decreased pyruvate decarboxylase activity.

Isobutanol production by K. pneumoniae T290L was improved.

Macrophage migration inhibitory factor levels are associated with disease activity and possible complications in membranous nephropathy

Membranous nephropathy (MN) is an autoimmune disease characterized by the deposition of immunoglobulin G (IgG) and complementary components in the epithelium of the glomerular capillary wall. Macrophage migration inhibitory factor (MIF) is an inflammatory mediator released by macrophages. MIF plays a key regulatory function in the pathogenesis of immune-mediated glomerulonephritis. This study aimed to investigate whether MIF level could be associated with the activity of MN. Plasma and urine samples from 57 MN patients and 20 healthy controls were collected. The MIF levels in plasma and urine were determined by an enzyme-linked immunosorbent assay (ELISA) kit. The expression of MIF in the renal specimens from 5 MN patients was detected by immunohistochemistry (IHC). The associations of the plasma and urinary levels of MIF and glomerular MIF expression with clinical and pathological characteristics were analyzed. It was revealed that with the increase of MIF levels in plasma and urine, the severity of renal pathological injury in MN patients gradually increased. Correlation analysis showed that the MIF levels in plasma were positively correlated with the platelet (PLT) count (r = 0.302, P = 0.022), and inversely correlated with the prothrombin time (PT) (r =  - 0.292, P = 0.028) in MN patients. The MIF levels in plasma were positively correlated with the C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) (r = 0.651, P < 0.0001; r = 0.669, P < 0.0001) in MN patients. The urinary levels of MIF were positively correlated with ESR (r = 0.562, P < 0.0001). IHC suggested that MIF was expressed in glomerular basement membrane and tubulointerstitial areas. MIF levels in plasma and urine could reflect the severity of MN, and MIF levels in plasma and urine could be associated with venous thrombosis and infectious complications in MN patients. The glomerular MIF expression could be used to indicate the activity of MN.

Ultrathin fluoroacrylic coating wrapped microporous non-woven fabrics as efficient air filtration membranes

Ultrathin fluoroacrylic emulsion coating wrapped effective microporous non-woven air filtration membranes of 0.2 μm thickness were made for PPE masks with up to 99.9% filtration efficiencies for both 0.3 μm NaCl aerosol particles and oily DEHS aerosols. An ultrasonic dip-coating process was applied for the controllable formation of a nano-protrusion morphology on the fiber surface.

Micro-physical parameter dynamic evolution behaviour of a natural ester molecular chain under a changing electric field and its correlation mechanism with lightning impulse discharge: theoretical analysis

The lightning impulse breakdown properties of natural esters are very important for their further applications. This paper focuses on the discharge mechanism investigation of a natural ester insulating liquid under a lightning impulse electric field. Based on density functional theory (DFT), the configuration, electron structure, ionization and electron affinity process, excitation process and molecular orbital of natural ester molecules were calculated under different electric field strengths. A correlation mechanism between the micro-physical parameters of ester insulating liquid molecules and discharge was proposed. The molecular electrostatic potential was used to predict the active point of discharge. The results show that the molecular structure of triglycerides shows yield behaviour under electric field action. The electrons are redistributed in the direction of the source of the electric field. Among the four triglycerides, the ionization and electron affinity process, excitation process and molecular orbital of glycerol tripalmitate were least affected by the electric field. The microscopic properties of other triglycerides were significantly affected by the electric field. According to the electrostatic potential (ESP) result of natural ester molecules, it can be predicted in the experiment that the surface of H atoms of the triglyceride ester group easily forms electron traps to bind electrons, while the surface of an O atom at the ester of a triglyceride undergoes electron collisions resulting in an electrical discharge. The proportion of palmitic acid in natural esters could be increased or pure glycerol tripalmitate could be used as an insulating oil to solve the problem of the low lightning impulse breakdown voltage of natural esters.

Ambient-Pressure Recoverable Polynitrogen Solids Assembled by Pentazolate Rings with High Energy Density

Crystal structure predictions and first-principles calculations were used to predict three polynitrogen solids (aP8-N, aP12-N, and oP24-N) that possess competitive enthalpies as compared to the synthesized open-chain N₈ phase at pressures in the range of 0-60 GPa. aP8-N, aP12-N, and oP24-N contain edge-shared, N₂-linked, and N-bridged pentazolate rings and form molecular N₈, molecular N₁₂, and quasi-one-dimensional N_∞ ribbons, respectively. The calculations of formation enthalpies show that the three polynitrogen solids can be synthesized by compressing cyclo-N₅ salts in hydrogen-saturated environments. Molecular simulations suggest that the three polynitrogen solids have the ability of quench recoverability under ambient conditions once being synthesized at high pressure. With estimated energy densities in the range of 5.6-6.5 kJ/g, these three polynitrogen phases show notable promise for applications as high-energy-density materials.