Preparation and Characterization of Bismaleimide-Resin-Based Composite Materials.

This study utilized bismaleimide (BMI) resin, reinforced with introduced ether bonds, as a binding matrix, in combination with silicon carbide (SiC), for the fabrication of composite materials. A thorough investigation was conducted to assess the influence of diverse processing parameters on the mechanical properties and high-temperature thermo-oxidative stability of these composites. Experimental results indicate a notable improvement in the mechanical properties of the composites upon the incorporation of ether bonds, in contrast to their unmodified counterparts. The variation in performance among composites with different ratios and molding densities is apparent. Within a certain range, an increase in resin content and molding density is correlated with improved bending strength in the composites. With a resin content of 27.5 vol% and a molding density of 2.31 g/cm3, the composite achieved a maximum flexural strength of 109.52 MPa, representing a 24% increase compared to its pre-modification state. Even after exposure to high-temperature heat treatment, the composites displayed commendable mechanical properties compared to their pre-ether bond modification counterparts, maintaining 74.5% of the strength of the untreated composites at 300 °C. The scanning electron microscopy (SEM) microstructures of composite materials correlate remarkably well with their mechanical properties.

Research on Sol-Gel Synthesis of Low-Temperature Na2O-B2O3-SiO2 Vitrified Bonds and Preparation of High-Strength Stacked Abrasives Using the Molding and Crushing Method.

Currently, the sol-gel technique is employed in the synthesis of high-performance vitrified bonds; however, its application in the fabrication of stacked abrasives has been minimally explored. Furthermore, the methods utilized in the production of abrasive particles for stacked abrasives are technically challenging and incur high costs, which hinders their actual industrial application. Consequently, this study utilizes the sol-gel approach to synthesize a Na2O-B2O3-SiO2 ternary system vitrified bond powder and employs a molding and crushing method, which offers a lower technological barrier and reduced preparation costs, for the production of abrasive particles subsequently fabricating corundum stacked abrasives. Upon setting the binder composition to a molar ratio of n(SiO2):n(B2O3):n(Na2O) = 65:23:12, it was observed that the crystallization within the glass matrix was minimized and the optimal sintering temperature for the synthesized laminate abrasive to be sustained at 820 °C. At the aforementioned temperature, the binder melt is capable of flowing uniformly amongst the abrasive granules, thereby ensuring a robust encapsulation of the particles. The average single particle compressive strength of the prepared corundum stacked abrasive with a grain size of forty mesh can reach the highest of all composition points at 28.56 N and the average single particle compressive strength of the prepared diamond stacked abrasive is 28.14 N.

Rim-Based Binding of Perfluorinated Acids to Pillararenes Purifies Water.

Per- and polyfluoroalkyl substances (PFAS) pose a rapidly increasing global problem as their widespread use and high stability lead worldwide to water contamination, with significant detrimental health effects.[1] Supramolecular chemistry has been invoked to develop materials geared towards the specific capture of PFAS from water,[2] to reduce the concentration below advisory safety limits (e.g., 70 ng/L for the sum of perfluorooctane sulfonic acid, PFOS and perfluorooctanoic acid, PFOA). Scale-up and use in natural waters with high PFAS concentrations has hitherto posed a problem. Here we report a new type of host-guest interaction between deca-ammonium-functionalized pillar[5]arenes (DAF-P5s) and perfluoroalkyl acids. DAF-P5 complexes show an unprecedented 1 : 10 stoichiometry, as confirmed by isothermal calorimetry and X-ray crystallographic studies, and high binding constants (up to 106 M-1) to various polyfluoroalkyl acids. In addition, non-fluorinated acids do not hamper this process significantly. Immobilization of DAF-P5s allows a simple single-time filtration of PFAS-contaminated water to reduce the PFOS/PFOA concentration 106 times to 15-50 ng/L level. The effective and fast (<5 min) orthogonal binding to organic molecules without involvement of fluorinated supramolecular hosts, high breakthrough capacity (90 mg/g), and robust performance (>10 regeneration cycles without decrease in performance) set a new benchmark in PFAS-absorbing materials.

Tunable Supramolecular Ag+-Host Interactions in Pillar[n]arene[m]quinones and Ensuing Specific Binding to 1-Alkynes.

We developed an improved, robust synthesis of a series of pillar[6]arenes with a varying number (0-3) of quinone moieties in the ring. This easy-to-control variation yielded a gradually less electron-rich cavity in going from zero to three quinone units, as shown from the strength of host-guest interactions with silver ions. Such macrocycle-Ag2 complexes themselves were shown to display an unprecedented, sharp distinction between terminal alkynes, which strongly bound to such complexes, and internal alkynes, internal alkenes and terminal alkenes, which do hardly bind.

Synthesis of Large Macrocycles with Chiral Sulfur Centers via Enantiospecific SuFEx and SuPhenEx Click Reactions.

Here we report the first asymmetric synthesis of large chiral macrocycles with chiral sulfur atoms. Building on stereospecific SuFEx and SuPhenEx click chemistries, this approach utilizes disulfonimidoyl fluorides and disulfonimidoyl p-nitrophenolates─which are efficient building blocks with two chiral sulfur centers, and diphenols to efficiently form novel S-O bonds. Characteristic results include the enantiospecific one-step synthesis of rings consisting of 21-58 members and characterization of both enantiomers (R,R and S,S) by e.g. X-ray crystallography.

Preparation and Characterization of Carbide Particle-Toughened Si-B System of High Thermostability Polycrystalline Diamond by HPHT Sintering.

In this research, we report the synthesis of Si-TmC-B/PCD composites using Si, B, and transition metal carbide particles (TmC) as binders at high pressure and high temperature (HPHT method, 5.5 GPa and 1450 °C). The microstructure, elemental distribution, phase composition, thermal stability, and mechanical properties of PCD composites were systematically investigated. The Si-B/PCD sample is thermally stable in air at 919 °C. The initial oxidation temperature of the PCD sample with ZrC particles is as high as 976 °C, and it also has a maximum flexural strength of 762.2 MPa, and the highest fracture toughness of 8.0 MPa·m1/2.

Development of a monoclonal antibody recognizing novel linear neutralizing epitope on H protein of canine distemper virus vaccine strains (America-1 genotype).

Canine distemper virus (CDV) is an economically important virus responsible for canine distemper (CD), a highly contagious disease that afflicts various animal species worldwide. The hemagglutinin (H) protein is the major neutralizing target of virus. Therefore, it is often considered as immunogen to prepare neutralizing antibodies. The accurate identification of neutralizing epitope will provide important antigenic information and extend the knowledge of mechanisms of virus neutralization. In this study, we generated a neutralizing monoclonal antibody (mAb) 4C6 against CDV H protein, and defined the minimal linear epitope 238DIEREFDT245, which was highly conserved in America-1 genotype of CDV strains (vaccines). The mAb 4C6 could not react with a CDV strain that had two substitutions of D238Y and R241G in the epitope, which appeared in most CDV strains of the other genotypes. Besides, a few different amino acid mutations in the epitope were also included. Collectively, the epitope 238DIEREFDT245 was variable in the other genotypes of CDV strains. The epitope 238DIEREFDT245 was exposed to the surface of CDV H protein, showing good antigenicity. These data will provide insights into structure, function and antigenicity of H protein and lay the foundation for the development of diagnostic technologies and vaccine design for CDV.

Preparation and cutting performance study of YSZ-toughened PcBN superhard tools.

Titanium alloy, as a recognized difficult-to-cut material, places higher demands on the performance of cutting tools. Compared with the mainstream cemented carbide tools, PcBN tools have a higher life and better machining performance. In this paper, a new type of cubic boron nitride superhard tool was prepared by introducing Y2O3-stabilized ZrO2 (YSZ) under high temperature and high pressure (1500 °C, 5.5 GPa), and the effect of the variation of YSZ addition on the mechanical properties of the tool was systematically analyzed, and the cutting performance of the tool was also analyzed by cutting TC4. It was found that a small amount of YSZ addition, which generated a sub-stable t-ZrO2 phase during the sintering process, could improve the mechanical properties of the tool and increase its cutting life. When YSZ was added at 5 wt%, the flexural strength and fracture toughness of the composites reached the maximum values of 637.77 MPa and 7.18 MPa m1/2, while the cutting life of the tools reached the maximum value of 2615.81 m. And when YSZ was added at 2.5 wt%, the hardness of the material reached the maximum value of 43.62 GPa.

Handcuff-like metallo-pseudorotaxanes consisting of tiara[5]arene wheels and dimeric silver trifluoroacetate axles.

The complexation between tiara[5]arene (T[5]) and silver trifluoroacetate affords a binuclear metallo-pseudorotaxane on account of multiple endo-cavity AgI η2-arene interactions. Furthermore, two such enantiomeric [(CF3CO2Ag)2⊂T[5]] complexes are bridged by an extra (CF3CO2Ag)2 dimer through exo-wall AgI η2-arene coordination, resulting in a unique handcuff metallo-bis-pseudorotaxane structure in the solid state.

Gpx4, Selenov, and Txnrd3 Are Three Most Testis-Abundant Selenogenes Resistant to Dietary Selenium Concentrations and Actively Expressed During Reproductive Ages in Rats.

Almost all selenogenes are expressed in the testis, and those have the highest and constant expressions will be the primary candidates for functional analysis of selenium (Se) in male reproduction. This study aimed to profile the mRNA expressions of the testis-abundant selenogenes of rat models in responses to growth and dietary Se concentrations. Forty-eight weaning SD male rats were fed Se deficient basal diet (BD) for 5 weeks and then randomly grouped (n = 12/group) for being fed BD or BD plus 0.25, 3, or 5 mg Se/kg for 4 more weeks before sacrifice. Abundances of selenogenomic mRNAs in the liver and testis were determined with relative qPCR and those of the testis-abundant selenogenes in 13 kinds of tissues were assayed with a molecular beacon-based qPCR. Spatiotemporal expressions of rat selenogenome were also analyzed with the RNA-Seq transcriptomic data published by NCBI. mRNA abundances of glutathione peroxidase 4 (Gpx4), nuclear Gpx4 (nGpx4), selenoprotein V (Selenov), and thioredoxin reductase 3 (Txnrd3) in the testis were significantly higher than that in any other tissues (P < 0.05). Moreover, testicular mRNA abundances of Gpx4, Selenov, and Txnrd3 were not affected by levels of dietary Se supplementation (P > 0.05), and much higher at 6-21 weeks old than at 2 and 104 weeks old (P < 0.05). The result showed that Gpx4, Selenov, and Txnrd3 were most highly expressed in the testis of rats especially at reproductive ages and resistant to the impact of dietary Se levels, which suggested their specific importance in male reproduction.

Pyrazinamide Resistance and pncA Mutation Profiles in Multidrug Resistant Mycobacterium Tuberculosis.

Purpose: Pyrazinamide (PZA) is a critical component of standardized chemotherapy for tuberculosis (TB) and is recommended for the treatment of multidrug-resistant (MDR) TB. We aimed to characterize mutations in pncA of M. tuberculosis and evaluate their diagnostic accuracy for PZA susceptibility in China. We also combined genotypic methods with phenotypic susceptibility testing and pyrazinamidase (PZAse) activity to confirm PZA-resistant M. tuberculosis isolates. Results: An evaluation of 82 MDR M. tuberculosis strains revealed that 28.0% (23/82) were phenotypically resistant to 100 mg/L PZA and 15.9% (13/82) showed resistance to 300 mg/L PZA. Mutations in pncA were detected at 33 unique sites, and the majority were point mutations. No evident mutation hotspots or mutations affecting multiple amino acids were found, but the association between pncA mutations and PZA resistance was significant under 100 and 300 mg/L. The sensitivity of pncA mutation detection for predicting PZA susceptibility was 82.6% (19/23), and the specificity was 61.0% (36/59), based on 100 mg/L PZA, whereas the sensitivity was 84.6% (11/13) and the specificity was 55.1% (38/69), based on 300 mg/L PZA. All mutations identified in the highly PZA-resistant (300 mg/L) strains had an 80% loss relative to PZAse activity. No evident PZAse activity loss was observed in one synonymous mutation strain and the loss exceed 60% in all other strains. Conclusion: The association between pncA mutation and PZA resistance was significant. Relatively, the molecular method have shown better reliability than the phenotypic method for the detection of PZA resistance. This provides a theoretical basis for the clinical diagnosis of drug-resistant TB.

Economic evaluation of margetuximab vs. trastuzumab for pretreated ERBB2-positive advanced breast cancer in the US and China.

Objective: To assess the economic evaluation of margetuximab plus chemotherapy over trastuzumab plus chemotherapy for women with pretreated ERBB2-positive advanced breast cancer in the United States (US) and China. Methods: Based on the SOPHIA trial, a three-state Markov model was developed to compare the cost and efficacy of margetuximab to trastuzumab for previously treated women with ERBB2-positive advanced breast cancer. The model inputs were derived from existing literature and the US life table. Primary outcomes included lifetime costs in US dollars, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were conducted to evaluate the impact of uncertainty. Results: The base case analyses demonstrated that margetuximab plus chemotherapy had an increasing cost of $68,132 and $20,540 over trastuzumab plus chemotherapy in the US and China, respectively, with a gain of 0.11 and 0.09 QALYs both favored margetuximab. The ICERs for two treatment strategies were $260,176 in the US and $630,777 in China, resulting in a poor cost-effectiveness at their respective threshold of willingness to play. One-way sensitivity analyses showed that the results to be most sensitive to the price of margetuximab and that of trastuzumab. And an 11 and 82% price reduction of margetuximab would make this regimen cost-effective in the US and China, respectively. Conclusion: In the US and China, margetuximab plus chemotherapy is not likely to be cost-effective for women with pretreated ERBB2-positive advanced breast cancer, whereas price reduction effectively improves insufficient cost-effectiveness.

The Impact of Foaming Effect on the Physical and Mechanical Properties of Foam Glasses with Molecular-Level Insights.

Foaming effect strongly impacts the physical and mechanical properties of foam glass materials, but an understanding of its mechanism especially at the molecular level is still limited. In this study, the foaming effects of dextrin, a mixture of dextrin and carbon, and different carbon allotropes are investigated with respect to surface morphology as well as physical and mechanical properties, in which 1 wt.% carbon black is identified as an optimal choice for a well-balanced material property. More importantly, the different foaming effects are elucidated by all-atomistic molecular dynamics simulations with molecular-level insights into the structure-property relationships. The results show that smaller pores and more uniform pore structure benefit the mechanical properties of the foam glass samples. The foam glass samples show excellent chemical and thermal stability with 1 wt.% carbon as the foaming agent. Furthermore, the foaming effects of CaSO4 and Na2HPO4 are investigated, which both create more uniform pore structures. This work may inspire more systematic approaches to control foaming effect for customized engineering needs by establishing molecular-level structure-property-process relationships, thereby, leading to efficient production of foam glass materials with desired foaming effects.

Durvalumab consolidation therapy in patients with stage III non-small cell lung cancer after concurrent chemoradiation: a China-based cost-effectiveness analysis.

OBJECTIVE: To evaluate the cost-effectiveness of durvalumab in post-chemoradiotherapy patients with unresectable stage III NSCLC from the Chinese healthcare system perspective. METHODS: The study developed a five-health state Markov model to evaluate the cost-effectiveness of durvalumab consolidation therapy in post-chemoradiotherapy patients based on the PACIFIC clinical trial. Sensitivity and scenario analyses were performed to evaluate the model uncertainty. RESULTS: Durvalumab consolidation therapy provided an additional 1.22 quality-adjusted life-years (QALYs), with an incremental cost of $24,397 compared to no consolidation therapy in unselected patients. Durvalumab consolidation therapy was cost-effective as it yielded an incremental cost-effectiveness ratio (ICER) of $20,000 per QALY gained at a willingness-to-pay (WTP) threshold of $31,494 per QALY. In the patient subgroup with PD-L1-expressing tumors (≥1%), durvalumab was associated with an ICER of $33,058/QALY, resulting in a slight skewing away from the given cost-effectiveness threshold. The sensitivity analysis showed that ICERs were most sensitive to the cost of durvalumab, the cost of pembrolizumab, and the body weight of patients, regardless of PD-L1 expression selection. CONCLUSION: Durvalumab consolidation therapy is likely to be cost-effective in China, which indicates that expensive immunotherapies can gain clinical benefits at a justifiable cost in developing countries as well.

Economic Evaluation of First-Line Camrelizumab for Advanced Non-small-cell Lung Cancer in China.

Background: As the first domestic PD-1 antibody approved for lung cancer in China, camrelizumab has exhibited proven effectiveness for non-small-cell lung cancer (NSCLC) patients. However, the cost-effectiveness of this new regimen remains to be investigated. Objective: To evaluate the cost-effectiveness of camrelizumab combination therapy vs. chemotherapy for previously untreated patients with advanced, non-squamous NSCLC without Alk or Egfr genomic aberrations from the perspective of China's healthcare system. Methods: Based on the CameL trial, the study developed a three-health state Markov model to evaluate the cost-effectiveness of adding camrelizumab to chemotherapy compared to chemotherapy alone in NSCLC patients. The analysis models were conducted for patients unselected by PD-L1 tumor expression (the base case) and the patient subgroup with PD-L1-expressing tumors (≥1%). Primary model outcomes included the costs in US dollars and health outcomes in quality-adjusted life-years (QALYs) as well as the incremental cost-effectiveness ratio (ICER) under a willingness-to-pay threshold of $31,500 per QALY. Additionally, a scenario analysis that adjusted within-trial crossover was employed to evaluate camrelizumab combination therapy compared to chemotherapy without subsequent use of PD1/PD-L1 antibodies. Results: Camrelizumab combination therapy was more costly and provided additional 0.11 QALYs over chemotherapy in the base case analysis (0.86 vs. 0.75 QALYs), 0.12 QALYs over chemotherapy in the subgroup analysis (0.99 vs. 0.88 QALYs), and 0.34 QALYs over chemotherapy in the scenario analysis (0.86 vs. 0.52 QALYs). Correspondingly, the ICER was $63,080 per QALY, $46,311 per QALY, and $30,591 per QALY, in the base case, the subgroup, and the scenario analysis, respectively. One-way sensitivity analyses revealed that ICERs of the base case and the subgroup analysis were most sensitive to the cost of camrelizumab, the cost of pemetrexed. Besides, the base case and subgroup analysis were more sensitive to the risk of neutrophil count decreased in the camrelizumab and the utility of stable disease, respectively. Conclusion: Although camrelizumab combination therapy is not cost-effective as first-line therapy for NSCLC patients in China in the base case, adjusting within-trial crossover would move the treatment regimen toward cost-effectiveness in the scenario analysis.

Development and Verification of an Immune-Based Gene Signature for Risk Stratification and Immunotherapeutic Efficacy Assessment in Gastric Cancer.

OBJECTIVE: Due to the molecular heterogeneity of gastric cancer, only minor patients respond to immunotherapeutic schemes. This study is aimed at developing an immune-based gene signature for risk stratification and immunotherapeutic efficacy assessment in gastric cancer. METHODS: An immune-based gene signature was developed in gastric cancer by LASSO method in the training set. The predictive performance was validated in the external datasets. KEGG pathways related to risk scores were assessed by GSEA. Based on multivariate Cox regression analysis, a nomogram was established. Sensitivity to chemotherapy drugs was evaluated between high- and low-risk samples. The relationships of risk scores with infiltration levels of immune cells, stromal scores, immune scores, immune cell subgroups, and overall response to anti-PD-L1 therapy were determined. RESULTS: Our results showed that high risk scores were indicative of undesirable survival outcomes both in the training set (p < 0.0001) and the validation set (p = 0.002). Moreover, this signature could independently predict patients' survival (HR: 2.656 (1.919-3.676) and p < 0.001). Subgroup analysis confirmed the sensitivity of this signature in predicting prognosis (all p < 0.05). Cancer-related pathways were primarily enriched in high-risk samples, such as MAPK and TGF-ß pathways (p < 0.05). By incorporating stage and the risk score, we established a nomogram for predicting one-, three-, and five-year survival probability. Patients with high-risk scores were more sensitive to chemotherapy drugs (p < 0.05). There was heterogeneity in immune cells between high- and low-risk samples (p < 0.05). Samples with progressive disease exhibited the highest risk score, and those with complete response had the lowest risk score (p < 0.05). CONCLUSION: This immune-based gene signature might be representative of a promising prognostic classifier for predicting risk stratification and immunotherapeutic efficacy in gastric cancer, assisting personalized therapy and follow-up plan.

The Relationship between Internet Use and Health among Older Adults in China: The Mediating Role of Social Capital.

A growing academic attention has been paid to the health effects of Internet use among older adults. However, the relationship between Internet use and health among older adults in China remains to be studied further. On the one hand, existing research is still controversial on this issue. On the other hand, the underlying mechanism of how Internet use affects the health of older adults has not been fully explored. This article examined the relationship between Internet use and health among older adults with the mediating role of social capital in China based on the 2018 wave of China Health and Retirement Longitudinal Study (CHARLS). This study reveals that Internet use has a positive association with the health of older adults, and the positive effects of internet use among older adults are heterogeneous in age and residential location. In addition, this study also demonstrates that social capital plays a partial mediating role between Internet use and physical health among older adults. It is important for the government to take effective measures to expand Internet use and enhance social capital among older adults.

First-line atezolizumab plus chemotherapy in advanced non-squamous non-small cell lung cancer: a cost-effectiveness analysis from China.

Objective: To assess the cost-effectiveness of atezolizumab in combination with carboplatin plus nab-paclitaxel-based chemotherapy versus chemotherapy alone for first-line treatment of advanced non-squamous non-small cell lung cancer (NSCLC) from the Chinese healthcare system perspective.Methods: A Markov model was developed based on the IMpower130 clinical trial. Drug costs and health state utility were obtained from the literature. Outcomes included life-years (LYs), quality-adjusted life-years (QALYs), lifetime costs, and incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to evaluate the model uncertainty.Results: When compared to chemotherapy alone, atezolizumab plus chemotherapy provides an additional 0.34 LY and 0.19 QALY, and has an ICER of $180,560.15 per additional LY gained and that of $325,328.71 per QALY gained. Sensitivity analysis revealed that the results were most sensitive to changes in atezolizumab cost. Probabilistic sensitivity analysis showed that there was a 0% probability that atezolizumab plus chemotherapy was cost-effective at willingness-to-pay values of $30,828 per QALY. If the WTP threshold increased to $325,000 per QALY, atezolizumab plus chemotherapy has a 50% chance to be cost-effective.Conclusions: From the Chinese healthcare system perspective, atezolizumab combination is not cost-effective for first-line therapy of advanced non-squamous NSCLC.

Molecular epidemiology and genetic evolution of canine parvovirus in East China, during 2018-2020.

Canine parvovirus type 2 (CPV-2) emerged in the late 1970s, which caused high rates of morbidity and mortality in dogs. In last decade, five genetic variants (CPV-2a, CPV-2b, CPV-2c, New CPV-2a, and New CPV-2b) were frequently reported in the dog population, and replaced the original CPV-2, rising widespread concerns. However, little is known about their recent genetic diversity and evolution. The aim of this study was to analyze the characteristics of the CPV-2 strains collected in East China from 2018 to 2020. The 57 CPV-2 strains were isolated from rectal swab samples (n=140). They belong to three different genotypes, based on VP2 protein amino acid sequence. The results revealed a high prevalence of CPV-2c (77.19%) compared to the New CPV-2a (5.26%) and New CPV-2b (17.54%) strains. Further analysis showed that nucleotide homology of the VP2 gene among the 57 CPV strains was 98.9%~100%, and the homology with 24 reference strains from different countries and regions was 98.1%~100%. The phylogenetic tree of VP2 gene sequence showed that 44 CPV-2c strains were distantly related to CPV-2, CPV-2a, CPV-2b, New CPV-2a, New CPV-2b and European/American CPV-2c strains, and were closely related to Asian CPV-2c strains. The results showed that these Asian CPV-2c strains had become the dominant strain, which renewed the knowledge of CPV-2 molecular epidemiology in East China.