Construction and Evaluation of the Brucella Double Gene Knock-out Vaccine Strain MB6 Δbp26ΔwboA (RM6)

Brucellosis is a serious zoonotic infection worldwide. To date, vaccination is the most effective measure against brucellosis. This study was aimed at obtaining a vaccine strain that has high protective efficacy and low toxicity, and allows vaccination to be differentiated from infection. Using homologous recombination, we constructed a double gene-deletion Brucella strain MB6 Δbp26ΔwboA (RM6) and evaluated its characteristics, safety and efficacy. The RM6 strain had good proliferative ability and stable biological characteristics in vivo and in vitro. Moreover, it had a favorable safety profile and elicited specific immune responses in mice and sheep. The RM6 strain may have substantial practical application value

Development and Efficacy Evaluation of an SP01-adjuvanted Inactivated Escherichia Coli Mutant Vaccine Against Bovine Coliform Mastitis

Escherichia coli ( E. coli ) is one of the most common pathogens causing clinical mastitis in cattle, but no vaccine is available to prevent this disease in China. Therefore, development of an E. coli vaccine against bovine clinical mastitis is urgently needed. The candidate vaccine (Ch-O111-1) and challenge (LZ06) strains were screened from milk samples of cows with clinical mastitis. To extend the cross-protection of the Ch-O111-1 strain, we deleted the galE gene fragment of the Ch-O111-1 strain through homologous recombination between the Ch-O111-1 strain and pCVD442/ΔgalE plasmid, which was identified through conventional methods, including PCR, SDS-PAGE and sequencing. The Ch-O111-1/ΔgalE (Z9) strain was characterized by extensive cross-reactivity and attenuated virulence. We prepared inactivated Z9 vaccines with different adjuvants. Immunization of inactivated Z9 antigen induced adjuvant-, dosage- and inoculation time-dependent antibody titers in cows and mice. Furthermore, immunization with SP01-adjuvanted inactivated Z9 vaccine protected cows against severe clinical mastitis caused by LZ06 and protected mice against death due to LZ06. An SP01-adjuvanted inactivated Z9 vaccine was successfully developed and found to protect cows against severe mastitis caused by Escherichia coli

Preparation of Equine Immunoglobulin F(ab′) 2 against Smallpox and Evaluation of its Immunoprotective Effect

Smallpox, a severe infectious disease caused by the smallpox virus, causes a death rate as high as 30% within 15-20 days after infection. Therefore, development of anti-Smallpox product as a strategic reserve is urgently needed. We prepared and tested pepsin-digested F(ab′) 2 fragments of serum IgG from horses. Transmission electron microscopy indicated that the purified virus showed morphology consistent with VVTT. The titer was above 1.0 × 10 7 PFU/mL. The purity of the antigen exceeded 90%, according to HPLC. After purification and cleavage, the yield of the purified product F(ab′) 2 was approximately 1.3%, its purity exceeded 90%, and the neutralizing antibody titer exceeded 1:3200. F(ab′) 2 fragments had good preventive and therapeutic effects in mice at antibody doses of 5.2 mg/mL and 2.6 mg/mL. The viral loads of the drug-treated mice were suppressed to varying degrees, and the higher dose groups (5.2 and 2.6 mg/mL) showed a 2-3 fold lower viral load than that in the control group. A process for producing equine immunoglobulin F(ab′) 2 against VVTT was established. The prepared horse anti-smallpox immunoglobulin product had good neutralizing antibody effects on VVTT. The highly purified preparation may serve as a potential candidate for smallpox treatment

Purified Immunoglobulin F(ab′) 2 Protects Mice and Rhesus Monkeys against Lethal Ricin Intoxication

Ricin is a highly toxic ribosome-inactivating lectin derived from castor beans. To date, no antidote is available to treat ricin-poisoned patients, and the development of a safe and effective antidote is urgently needed. First, ricin was prepared and used to construct a mouse model and a rhesus monkey model of ricin intoxication. Second, pepsin-digested F(ab′) 2 fragments of serum IgG from horses injected with Freund’s-adjuvanted purified ricin were prepared. Third, the protective efficacy was evaluated in mouse and rhesus monkey models of lethal ricin intoxication. The purity quotient of the prepared ricin and F(ab′) 2 fragments exceeded 90% and 85% in the mouse and monkey models, respectively. The LD 50 of ricin in mice and rhesus monkeys was 2.7 and 9 μg/kg, respectively. A quantity of 6.25 and 1.85 mg/kg F(ab′) 2 was sufficient to treat lethal ricin intoxication in the mice and rhesus monkeys, respectively. Finally, the effect of this therapeutic antibody on peripheral blood immune cells was examined by analysis of peripheral blood immune cells through single cell sequencing. The underlying mechanism was found to involve restraining neutrophil activation, proliferation, and differentiation. Purified F(ab′) 2 fragments administered with needle-free devices fully protect mice and rhesus monkeys against lethal doses of ricin intoxication

Dynamic Multi-Objective Optimization Inverse Prediction of Excavation-Induced Tunnel Displacement

Control of the disturbed displacement of adjacent tunnel during excavation is a significant issue for design and construction. Based on the multi-objective optimization method, the multi-type monitoring data in the excavation of the excavation are integrated, the key soil parameters are inverted and identified, and the time effect of the tunnel displacement is quantified and corrected. A dynamic multi-objective optimization method with adaptive infill criterion (DMO-AIC) is proposed to improve the updating efficiency of dynamic surrogate models. The proposed method takes into account the computational redundancy of dynamic surrogate models in engineering optimization, and designs an adaptive point-adding discrimination strategy, which can autonomously identify invalid updates of surrogate models on the optimization path. The results show that the proposed DMO-AIC significantly reduces the invocations of the black-box model during optimization while ensuring the good search performance and the convergence speed of the algorithm. The improved computational efficiency of DMO-AIC is helpful for the application of dynamic surrogate models in engineering optimization. The results of the virtual numerical example show that DMO-AIC can predict and update multiple model responses during excavation, such as wall deflections and tunnel displacements. The engineering practice of Shanghai Bund 596 excavation indicates that the time effect is properly updated, and the staged vertical displacements of the adjacent tunnel are accurately predicted

Tranexamic Acid for Blood Loss after Transforaminal Posterior Lumbar Interbody Fusion Surgery: A Double-Blind, Placebo-Controlled, Randomized Study

Background. Transforaminal lumbar interbody fusion (TLIF) may result in significant blood loss and an increase in blood transfusion. Though tranexamic acid (TXA) is widely studied for the hemostasis of arthroplasty, there is little information on the use of TXA for TLIF surgery. Methods. This prospective randomized, double-blind, placebo-controlled trial was conducted to study the influence of TXA (intravenous bolus of 10 mg/kg 15 minutes before skin incision followed by intravenous infusion of 6-8 mg/kg/h up to a total dose of 15 mg/kg during the surgery) on the blood loss and Enhanced Recovery After Surgery (ERAS) after TLIF surgery. 40 patients were randomized into two groups: TXA group (tranexamic acid) and control group (placebo). Baseline characteristics were comparable between the TXA group and the control group before the surgery. Outcomes assessed included blood loss, total postoperative drainage, time for drainage removal, time to ambulation, hospital stay after surgery, postoperative hemoglobin (Hb) one day after surgery, and adverse events. Results. Compared to patients in the control group after TLIF surgery, patients in the TXA group have significantly reduced intraoperative hemorrhage and time to ambulation after surgery but show similar hospital stay, postoperative drainage, time for drainage removal, postoperative Hb one day after surgery, and adverse events. Conclusions. TXA shows important ability in controlling blood loss and promoting the ERAS after TLIF surgery

Demo abstract: wind measurements for water quality studies in urban reservoirs

Water quality monitoring and prediction are critical for ensuring the sustainability of water resources which are essential for social security, especially for countries with limited land like Singapore. For example, the Singapore government identified water as a new growth sector and committed in 2006 to invest S$ 330 million over the following five years for water research and development [1]. To investigate the water quality evolution numerically, some key water quality parameters at several discrete locations in the reservoir (e.g., dissolved oxygen, chlorophyll, and temperature) and some environmental parameters (e.g., the wind distribution above water surface, air temperature and precipitation) are used as inputs to a three-dimensional hydrodynamics-ecological model, Estuary Lake and Coastal Ocean Model - Computational Aquatic Ecosystem Dynamics Model (ELCOM-CAEDYM) [2]. Based on the calculation in the model, we can obtain the distribution of water quality in the whole reservoir. We can also study the effect of different environmental parameters on the water quality evolution, and finally predict the water quality of the reservoir with a time step of 30 seconds. In this demo, we introduce our data collection system which enables water quality studies with real-time sensor data

PD-1-Targeted Discovery of Peptide Inhibitors by Virtual Screening, Molecular Dynamics Simulation, and Surface Plasmon Resonance

The blockade of the programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway plays a critical role in cancer immunotherapy by reducing the immune escape. Five monoclonal antibodies that antagonized PD-1/PD-L1 interaction have been approved by the Food and Drug Administration (FDA) and marketed as immunotherapy for cancer treatment. However, some weaknesses of antibodies, such as high cost, low stability, poor amenability for oral administration, and immunogenicity, should not be overlooked. To overcome these disadvantages, small-molecule inhibitors targeting PD-L1 were developed. In the present work, we applied in silico and in vitro approaches to develop short peptides targeting PD-1 as chemical probes for the inhibition of PD-1–PD-L1 interaction. We first predicted the potential binding pocket on PD-1/PD-L1 protein–protein interface (PPI). Sequentially, we carried out virtual screening against our in-house peptide library to identify potential ligands. WANG-003, WANG-004, and WANG-005, three of our in-house peptides, were predicted to bind to PD-1 with promising docking scores. Next, we conducted molecular docking and molecular dynamics (MD) simulation for the further analysis of interactions between our peptides and PD-1. Finally, we evaluated the affinity between peptides and PD-1 by surface plasmon resonance (SPR) binding technology. The present study provides a new perspective for the development of PD-1 inhibitors that disrupt PD-1–PD-L1 interactions. These promising peptides have the potential to be utilized as a novel chemical probe for further studies, as well as providing a foundation for further designs of potent small-molecule inhibitors targeting PD-1

An Intrinsically Microporous Network Polymer with Good Dielectric Properties at High Frequency

An intrinsically microporous fluoropolymer has been successfully synthesized through thermo-cross-linking of a functional monomer having a quaternary carbon center and thermopolymerizable trifluorovinyl ether groups as the side chains. Because the monomer has a tetrahedral configuration, the thermo-cross-linking produces spontaneously formed micropores with an average size of 8 Å in the polymer. Because of the existence of the micropores, the fluoropolymer exhibits excellent dielectric properties with dielectric constant (<i>D</i>_<i>k</i>) of 2.36 and dissipation factor (<i>D</i>_<i>f</i>) of 1.29 × 10^–3 at a frequency of 5 GHz. Moreover, the polymer shows very low water uptake (<0.08% in water of 99 °C for 72 h) and high transparency (transmittance of 93% varying from 400 to 1100 nm). TGA and DMA data show that the polymer has 5 wt % loss temperature of 492 °C (in N₂) and Young’s modulus of 4.95 GPa, respectively. These results suggest that the polymer is very suitable as the matrix resin for the production of the composites utilized in high-frequency printed circuit boards (HF-PCBs). In particular, this work is the first example for the production of a low <i>D</i>_<i>k</i> and <i>D</i>_<i>f</i> polymer using a strategy of spontaneously forming pores. Because HF-PCBs have a broad range of applications, this contribution is of considerable industrial importance