Search

Acute myocardial infarction (AMI) is one of the most severe cardiovascular diseases in humans, often resulting in unexpected death. Early detection is critical for patient survival. Sandwich ELISA is a common method for the detection of AMI. However, ELISA kits from different manufacturers can give different results, in part because of the lack of standardized epitopes. Therefore, the purpose of this study was to find two standardized epitopes. We predicted two antigen epitopes and respectively immunize mice to manufacture standardized monoclonal antibodies. Eight monoclonal antibodies were prepared. Monoclonal antibodies 7D2 and 2C3 were selected with high affinity, and their characteristics were explored. The results show that monoclonal antibodies 7D2 and 2C3 can both bind to various modified forms and complexes of cardiac troponin I (cTnI), were not cross‐reaction with related antigens of normal human serum and can be paired. Therefore, we deem epitopes 30 to 42 and 77 to 89 standardized epitopes. [ABSTRACT FROM AUTHOR]

As a crucial indicator in food and water safety testing, the detection of Escherichia coli plays a significant role in maintaining environmental sanitation and promoting public health. Herein, based on the electrochemical activity characteristics of E. coli, we established an enhanced electrochemiluminescence aptasensor for E. coli analysis. This study presents a new method for accurate identification by utilizing a double aptamer recognition system. Specifically, a nano-cadmium sulfide (CdS) modified aptamer was used for primary labeling, while a second aptamer was immobilized on a graphene/chitosan composite electrode for re-capture. The use of two aptamers improves the accuracy of the identification process. Furthermore, the application of an electrode potential facilitates continuous electron transfer between the electrode and electrochemically active microorganisms, resulting in an enhanced electroluminescence signal in relation to the metabolic status. This strategy possesses better sensitivity, accuracy, and stability, demonstrating its potential for E. coli analysis. [ABSTRACT FROM AUTHOR]

Purpose: Various studies have analyzed sepsis subtypes, yet the reproducibility of such results remains unclear. This study aimed to determine the reproducibility of sepsis subtypes across multiple cohorts. Methods: The study examined 63,547 sepsis patients from six distinct cohorts who had similar sepsis-related characteristics (vital signs, lactate, sequential organ failure assessment score, bilirubin, serum, urine output, and Glasgow coma scale). Identical cluster analysis techniques were used, employing 27 clustering schemes, and normalized mutual information (NMI), a metric ranging from 0 to 1 with higher values indicating better concordance, was employed to quantify the clustering solutions' reproducibility. Principal component analysis (PCA) was utilized to obtain the disease axis, and its uniformity across cohorts was evaluated through patterns of feature loading and correlation. Results: The reproducibility of sepsis clustering subtypes across the various studies was modest (median NMI ranging from 0.08 to 0.54). The top-down transfer learning method (model trained on cohorts with greater severity was transferred to cohorts with lower severity score) had a higher NMI value than the bottom-up approach (median [Q1, Q3]: 0.64 [0.49, 0.78] vs. 0.23 [0.2, 0.31], p < 0.001). The reproducibility was greater when the transfer solution was performed within United States (US) cohorts. The PCA analysis revealed that the correlation pattern between variables was consistent across all cohorts, and the first two disease axes were the "shock axis" and "systemic inflammatory response syndrome (SIRS) axis." Conclusions: Cluster analysis of sepsis patients across various cohorts showed modest reproducibility. Sepsis heterogeneity is better characterized through continuous disease axes that coexist to varying degrees within the same individual instead of mutually exclusive subtypes. [ABSTRACT FROM AUTHOR]

• An annular nozzle model with bi-directional coupling of transient processes was developed. • Comparative analysis of powder convergence characteristics by means of high-speed camera and simulation. • The heat of Fe-based powders under different parameters was studied using simulations and experimental methods. Extreme high-speed laser cladding technology (EHLA) is widely employed in critical parts manufacturing and repairing due to its high efficiency. The appearance and quality of the cladding layer are directly influenced by the powder flow characteristics and the interaction between powder trajectory and laser beam. In order to elaborate Fe-based powder flow characteristics of the EHLA process, this study established a powder flow model with a ring-shaped nozzle using a transient process bidirectional coupling. The accuracy of the powder flow model was verified using a high-speed camera. The results demonstrated that the error between the simulation results and the real-time images was within 10 %, confirming the validity of the powder flow model. The temperature profiles of laser-powder coupled model indicated that the optimal melting effect of Fe-based powder was achieved at a laser power of 1500 W. Moreover, the maximum elevation angle of the powder flow was mainly influenced by the carrier gas and protective gas flow rate. The experimental and simulation results showed that the optimal process was a protective gas flow rate of 40 L/min and a carrier gas flow rate of 7 L/min. [ABSTRACT FROM AUTHOR]

Understanding the molecular structural evolution mechanism during coal pyrolysis can help better regulate coal conversions for developing clean coal technology. This study investigated changes in functional groups and polycyclic aromatic hydrocarbons (PAHs) during pyrolysis of a perhydrous bituminous coal at temperature of 75–600 °C. Results indicated that aliphatic, C–O, C=O, OH, aromatic C=C, and aromatic C–H groups declined in relative abundance below 300 °C. These declines were attributed to cracking of hydrogen bonds and devolatilization. Meanwhile, the alkyl side chains of alkylated PAHs, i.e., alkyl-naphthalenes and alkyl-phenanthrenes, were continuously detached. Pyrolysis at 300–450 °C was characterized by elevated aromaticity, reflected by increments in the relative abundances of aromatic C–H, aromatic carbon, pyridine nitrogen, and protonated carbon. PAH evolutions at this stage exhibited relative increases of 4-–6-ring PAHs with relative decreases of 2-–3-ring PAHs. Pyrolysis at 450–600 °C was characterized by an increment of aromatic C=C and significant increases in relative abundances of 4-–6-ring PAHs in emitted particulate and gaseous phases. The elevation of pyrolysis temperature transformed coal macromolecules into more compact structure. The molecular structural units of chars were formulated as C 245 H 227 N 3 O 14 S, C 239 H 193 N 3 O 8 S, C 228 H 152 N 2 O 3 S, and C 221 H 113 NO 3 S for coal and chars produced at 300, 500, and 600 °C, respectively. Changes in three-dimensional molecular structural units reflected step-by-step intense deformation and condensed process. • The evolution behaviors of various functional groups varied at different temperature stages. • Hydrogen bond crackings, devolatilization, and dealkylation reactions occurred below 300 °C. • Aromatic and protonated carbons increased above 300 °C due to aromaticity elevation. • Changes in PAH compositions recorded dealkylation, polymerization and condensation reactions. • Molecular formulas varied from C 245 H 227 N 3 O 14 S for coal to C 221 H 113 NO 3 S for 600 °C char. [ABSTRACT FROM AUTHOR]

[Display omitted] • Changes in n -alkane, terpane, and sterane indices show the combined effects of maturation and depositional environment. • Pr/Ph, Pr/ n -C 17 , and Ph/ n -C 18 ratios record the influence of depositional environment. • Epimerization reactions of hopanes and steranes are affected by thermal maturity and origin. • Degree of demethylation consistently depends on rank but is higher in Da Baoding coals compared to Huainan coals. • Individual PACs indices show variable trends with maturity and are sensitive to organofacies. Biomarkers in coal can evolve dramatically in terms of their concentration and distribution during coalification, limiting their use in source allocation of coal-derived pollution. Here we analyzed a broad range of aliphatics (i.e., 26 n -alkanes, 6 isoprenoids, 32 terpanes, 19 steranes) and 77 polycyclic aromatic compounds (PACs) in the Permo-Carboniferous and Late Triassic coals from the Chinese Huainan and Da Baoding coalfields, respectively. These coals, classifying as high volatile bituminous B to low volatile bituminous with vitrinite reflectance (R r) values ranging from 0.71 to 1.74 %, show variable organic geochemical features owing to the combined effects of thermal maturity and organofacies. Changes in the n -alkanes and isoprenoids indicate the loss of aliphatic fractions associated with maturation owing to cracking of the long-chain alkanes. The stratigraphic changes in the pristane to phytane ratios (Pr/Ph), Pr/ n -C 17 , and Ph/ n -C 18 reflect a control exerted by the depositional environment in the Huainan coals. In addition, principal component analysis (PCA) recognizes the Pr/ n -C 17 , Ph/ n -C 18 , carbon preference index (CPI), and odd-to-even predominance 2 (OEP 2) as organofacies sensitive indices. Intercomparison of the PAC distributions suggest different maturation pathways for the coals from the Huainan and Da Baoding coalfields. The demethylation processes related to coalification preferentially occur on the polymethyl substitutes that occur to a greater degree in the Da Baoding coals than in the Huainan coals. Nine PAC indices display distinctive patterns when plotting against R r. The DMP-2 vs DBT:DBF cross-plot explicitly separates the Huainan and Da Baoding coals into three distinctive zones representing different depositional environments and sources of organic matter. Moreover, PCA explicitly discriminate the maturation sensitive indices (i.e., MNR, DNR-1, TrMN-1, TrMN, TeMN, MPR, and MPI-1) from organofacies sensitive indices (i.e., DMP-2 and DBT:DBF). [ABSTRACT FROM AUTHOR]

Increasing studies have demonstrated that sevoflurane can induce neurotoxicity in the developing brains. JNK normally promotes apoptosis. It was hypothesized that sevoflurane affected the proliferation and differentiation of FNSCs and induced cell apoptosis, which caused the learning and memory deficits via JNK pathway. Sevoflurane at a concentration of 1.2% did not induce damage on the FNSCS. However, concentrations of 2.4% and 4.8% decreased the cell viability, as shown by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and increased apoptosis, as shown by flow cytometry. The 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay demonstrated that 4.8% sevoflurane reduced the proliferation of FNSCs. Compared with the control group, the 4.8% sevoflurane group showed a decrease in the proportion of undifferentiated FNSCs at 6-h exposure; 4.8% sevoflurane could increase the p-JNK/JNK ratio. JNK inhibition by the specific inhibitor SP600125 enhanced partially the cell viability. Cumulatively, 4.8% sevoflurane induced significant damage on FNSCs; it decreased cell proliferation and proportion of undifferentiated cells as well. JNK pathway might play a key role in the decrease in survival of FNSCs induced by an inhaled anesthetic. The present findings might raise the possibility that JNK inhibition has therapeutic potential in protecting FNSCs from the adverse effects of the inhaled anesthetic. [ABSTRACT FROM AUTHOR]