A Real-Time Location-Based Services System Using WiFi Fingerprinting Algorithm for Safety Risk Assessment of Workers in Tunnels

This paper investigates the feasibility of a real-time tunnel location-based services (LBS) system to provide workers’ safety protection and various services in concrete dam site. In this study, received signal strength- (RSS-) based location using fingerprinting algorithm and artificial neural network (ANN) risk assessment is employed for position analysis. This tunnel LBS system achieves an online, real-time, intelligent tracking identification feature, and the on-site running system has many functions such as worker emergency call, track history, and location query. Based on ANN with a strong nonlinear mapping, and large-scale parallel processing capabilities, proposed LBS system is effective to evaluate the risk management on worker safety. The field implementation shows that the proposed location algorithm is reliable and accurate (3 to 5 meters) enough for providing real-time positioning service. The proposed LBS system is demonstrated and firstly applied to the second largest hydropower project in the world, to track workers on tunnel site and assure their safety. The results show that the system is simple and easily deployed

A Review of Spatter in Laser Powder Bed Fusion Additive Manufacturing: In Situ Detection, Generation, Effects, and Countermeasures

Spatter is an inherent, unpreventable, and undesired phenomenon in laser powder bed fusion (L-PBF) additive manufacturing. Spatter behavior has an intrinsic correlation with the forming quality in L-PBF because it leads to metallurgical defects and the degradation of mechanical properties. This impact becomes more severe in the fabrication of large-sized parts during the multi-laser L-PBF process. Therefore, investigations of spatter generation and countermeasures have become more urgent. Although much research has provided insights into the melt pool, microstructure, and mechanical property, reviews of spatter in L-PBF are still limited. This work reviews the literature on the in situ detection, generation, effects, and countermeasures of spatter in L-PBF. It is expected to pave the way towards a novel generation of highly efficient and intelligent L-PBF systems

A Novel Label-free Immunosensor Based on L-cysteine/deposited Gold Nanocrystals for the Chlorpyrifos Detection

In this paper, a novel label-free immunosensor for the chlorpyrifos residues detection was developed. This immunosenor was based on deposited gold nanocrystals (DpAus)/L-cysteine (L-Cys) modified Au electrode. The DpAus was used due to its unique properties: large surface and good conductivity, improve the performance of the electrode surface, rise the sensitivity of the current responsive. L-cysteine and DpAus were combined through Au-S bond. The immobilization of chlorpyrifos antibodies at the gold electrode was carried out through a stable acyl amino ester intermediate generated by 1-ethyl-3-(3-dime thylaminoprop-yl) carbodiimide (EDC) and N-hydrosuccinimide (NHS), which could condense antibodies highly efficient and immobilize them orientedly on the Au electrode surface. The sensitive steps of surface modification had been characterized by cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS), respectively. The immunoreaction between anti-chlorpyrifos monoclonal antibody and chlorpyrifos directly triggered a signal via different pulse voltammetry (DPV). Then we optimized conditions during the preparation of the immunosensor. The result was: the optimized pH of the working solution was 7.5, the optimized cubation time was 25 min. Under optimal conditions the immunosensor showed good response to chlorpyrifos, the rate of the peak current change of the biosensor were in linear with concentrations of chlorpyrifos from 1.0 to 200.0 ng/mL with a detection limit 0.17 ng/mL

An Amperometric Immunosensor Based on Multi-Walled Carbon Nanotubes-Thionine-Chitosan Nanocomposite Film for Chlorpyrifos Detection

In this work, a novel amperometric immunosensor based on multi-walled carbon nanotubes-thionine-chitosan (MWCNTs-THI-CHIT) nanocomposite film as electrode modified material was developed for the detection of chlorpyrifos residues. The nanocomposite film was dropped onto a glassy carbon electrode (GCE), and then the anti-chlorpyrifos monoclonal antibody was covalently immobilized onto the surface of MWCNTs-THI-CHIT/GCE using the crosslinking agent glutaraldehyde (GA). The modification procedure was characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, a linear relationship between the relative change in peak current of different pulse voltammetry (DPV) and the logarithm of chlorpyrifos solution concentration was obtained in the range from 0.1 to 1.0 × 105 ng/mL with a detection limit of 0.046 ng/mL. The proposed chlorpyrifos immunosensor exhibited high reproducibility, stability, and good selectivity and regeneration, making it a potential alternative tool for ultrasensitive detection of chlorpyrifos residues in vegetables and fruits

The intracellular domain of CX3CL1 regulates adult neurogenesis and Alzheimer’s amyloid pathology

The membrane-anchored CX3CL1 is best known to exert its signaling function through binding its receptor CX3CR1. This study demonstrates a novel function that CX3CL1 exerts. CX3CL1 is sequentially cleaved by α-, β-, and γ-secretase, and the released CX3CL1 intracellular domain (CX3CL1-ICD) would translocate into the cell nucleus to alter gene expression due to this back-signaling function. Amyloid deposition and neuronal loss were significantly reduced when membrane-anchored CX3CL1 C-terminal fragment (CX3CL1-ct) was overexpressed in Alzheimer's 5xFAD mouse model. The reversal of neuronal loss in 5xFAD can be attributed to increased neurogenesis by CX3CL1-ICD, as revealed by morphological and unbiased RNA-sequencing analyses. Mechanistically, this CX3CL1 back-signal likely enhances developmental and adult neurogenesis through the TGFβ2/3-Smad2/3 pathway and other genes important for neurogenesis. Induction of CX3CL1 back-signaling may not only be a promising novel mechanism to replenish neuronal loss but also for reducing amyloid deposition for Alzheimer's treatment.National Institute on Aging (Grant RF1AG054012

Ag-Carbenoid-Initiated Catalytic Hydration Cascades: Rapid Construction of Functionalized Bicyclo[3.3.1]nonanes

Remarkable Ag-carbenoid-initiated enone cyclopropanation–hydrolytic fragmentation–competitive 1,2-vs-1,4 addition reaction cascades were uncovered on a range of propargylic esters tethered to cyclohexadienones, leading to the highly efficient and stereospecific construction of densely functionalized bicyclo[3.3.1]nonanes under mild conditions

Bioengineering of a Lactococcus lactis subsp. lactis strain enhances nisin production and bioactivity.

Lactococcus lactis subsp. lactis is a food bacterium that has been utilized for decades in food fermentation and the development of high-value industrial goods. Among these, nisin, which is produced by several strains of L. lactis subsp. lactis, plays a crucial role as a food bio-preservative. The gene expression for nisin synthesis was evaluated using qPCR analysis. Additionally, a series of re-transformations of the strain introducing multiple copies of the nisA and nisRK genes related to nisin production were developed. The simultaneous expression of nisA and nisZ genes was used to potentiate the effective inhibition of foodborne pathogens. Furthermore, qPCR analysis indicated that the nisA and nisRK genes were expressed at low levels in wild-type L. lactis subsp. lactis. After several re-transformations of the strain with the nisA and nisRK genes, a high expression of these genes was obtained, contributing to improved nisin production. Also, co-expression of the nisA and nisZ genes resulted in extremely effective antibacterial action. Hence, this study would provide an approach to enhancing nisin production during industrial processes and antimicrobial activity

Safety and efficacy of ciprofol vs. propofol for sedation in intensive care unit patients with mechanical ventilation: a multi-center, open label, randomized, phase 2 trial

Abstract. Background:. Ciprofol (HSK3486; Haisco Pharmaceutical Group Co., Ltd., Chengdu, China), developed as a novel 2,6-disubstituted phenol derivative showed similar tolerability and efficacy characteristics as propofol when applicated as continuous intravenous infusion for 12 h maintenance sedation in a previous phase 1 trial. The phase 2 trial was designed to investigate the safety, efficacy, and pharmacokinetic characteristics of ciprofol for sedation of patients undergoing mechanical ventilation. Methods:. In this multicenter, open label, randomized, propofol positive-controlled, phase 2 trial, 39 Chinese intensive care unit patients receiving mechanical ventilation were enrolled and randomly assigned to a ciprofol or propofol group in a 2:1 ratio. The ciprofol infusion was started with a loading infusion of 0.1–0.2 mg/kg for 0.5–5.0 min, followed by an initial maintenance infusion rate of 0.30 mg·kg−1·h−1, which could be adjusted to an infusion rate of 0.06 to 0.80 mg·kg−1·h−1, whereas for propofol the loading infusion dose was 0.5–1.0 mg/kg for 0.5–5.0 min, followed by an initial maintenance infusion rate of 1.50 mg·kg−1·h−1, which could be adjusted to 0.30–4.00 mg·kg−1·h−1 to achieve −2 to +1 Richmond Agitation-Sedation Scale sedation within 6–24 h of drug administration. Results:. Of the 39 enrolled patients, 36 completed the trial. The median (min, max) of the average time to sedation compliance values for ciprofol and propofol were 60.0 (52.6, 60.0) min and 60.0 (55.2, 60.0) min, with median difference of 0.00 (95% confidence interval: 0.00, 0.00). In total, 29 (74.4%) patients comprising 18 (69.2%) in the ciprofol and 11 (84.6%) in the propofol group experienced 86 treatment emergent adverse events (TEAEs), the majority being of severity grade 1 or 2. Drug- and sedation-related TEAEs were hypotension (7.7% vs. 23.1%, P = 0.310) and sinus bradycardia (3.8% vs. 7.7%, P = 1.000) in the ciprofol and propofol groups, respectively. The plasma concentration-time curves for ciprofol and propofol were similar. Conclusions:. ciprofol is comparable to propofol with good tolerance and efficacy for sedation of Chinese intensive care unit patients undergoing mechanical ventilation in the present study setting. Trial registration:. ClinicalTrials.gov, NCT04147416