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Two hypotheses for the blocking effect mechanisms under the electromagnetic radiation are presented, and the corresponding dual-frequency interference prediction models are proposed, which can be used to predict the working state of equipment under the condition that the single-frequency susceptibility is known. By taking a radar and a communication radio as the EUT, the experiments of dual-frequency continuous wave electromagnetic radiation are designed and carried out to verify the prediction models. The test results show that the sensitive bandwidth of blocking interference effect for the tested radar and the communication station is consistent with their working bandwidth, respectively. By substituting the test data into the proposed prediction models, the prediction errors of the models are less than 13%. Moreover, it can be found that the tested radar is more sensitive to the peak value of electric field, and the tested communication station is more sensitive to the effective value of electric field.

Background Nattokinase is a fibrinolytic enzyme that has huge market value as a nutritional supplement for health promotion. In order to increase nattokinase yields, fermentation conditions, strains, cultivation media, and feeding strategies have been optimized. Nattokinase has been expressed using several heterologous expression systems. Pichia pastoris heterologous expression system was the alternative. Results This report aimed to express high levels of nattokinase from B. subtilis natto (NK-Bs) using a Pichia pastoris heterologous expression system and assess its fibrinolytic activity in vivo. Multicopy expression strains bearing 1–7 copies of the aprN gene were constructed. The expression level of the target protein reached a maximum at five copies of the target gene. However, multicopy expression strains were not stable in shake-flask or high-density fermentation, causing significant differences in the yield of the target protein among batches. Therefore, P. pastoris bearing a single copy of aprN was used in shake-flask and high-density fermentation. Target protein yield was 320 mg/L in shake-flask fermentation and approximately 9.5 g/L in high-density fermentation. The recombinant nattokinase showed high thermo- and pH-stability. The present study also demonstrated that recombinant NK-Bs had obvious thrombolytic activity. Conclusions This study suggests that the P. pastoris expression system is an ideal platform for the large-scale, low-cost preparation of nattokinase.

Methyl parathion hydrolase (MPH) hydrolyses methyl parathion efficiently and specifically. Herein, we produced MPH from Plesiomonas sp. M6 using a Pichia pastoris multi-copy expression system. The original signal peptide sequence of the target gene was removed, and a modified coding sequence was synthesised. Multi-copy expression plasmids containing MPH were constructed using pHBM905BDM, and used to generate recombinant strains containing 1, 2, 3 or 4 copies of the MPH gene. The results showed that a higher target gene copy number increased the production of recombinant MPH (MPH-R), as anticipated. The expression level of the recombinant strain containing four copies of the MPH gene was increased to 1.9 U/ml using 500 ml shake flasks, and the specific activity was 15.8 U/mg. High-density fermentation further increased the target protein yield to 18.4 U/ml. Several metal ions were tested as additives, and Ni2+, Co2+ and Mg2+ at a concentration of 1 mM enhanced MPH-R activity by 196%, 201% and 154%, respectively. Enzyme immobilisation was then applied to overcome the difficulties in recovery, recycling and long-term stability associated with the free enzyme. Immobilised MPH-R exhibited significantly enhanced thermal and long-term stability, as well as broad pH adaptability. In the presence of inhibitors and chelating agents such as sodium dodecyl sulphate (SDS), immobilised MPH-R displayed 2-fold higher activity than free MPH-R, demonstrating its potential for industrial application.

BackgroundAntiviral therapies against the novel coronavirus SARS-CoV-2, which has caused a global pandemic of respiratory illness called COVID-19, are still lacking.MethodsOur study (NCT04252885, named ELACOI), was an exploratory randomized (2:2:1) controlled trial assessing the efficacy and safety of lopinavir/ritonavir (LPV/r) or arbidol monotherapy for treating patients with mild/moderate COVID-19.FindingsThis study successfully enrolled 86 patients with mild/moderate COVID-19 with 34 randomly assigned to receive LPV/r, 35 to arbidol and 17 with no antiviral medication as control. Baseline characteristics of the three groups were comparable. The primary endpoints, the average time of positive-to-negative conversion of SARS-CoV-2 nucleic acid and conversion rates at days 7 and 14, were similar between groups (all P>0.05). There were no differences between groups in the secondary endpoints, the rates of antipyresis, cough alleviation, or improvement of chest CT at days 7 or 14 (all P>0.05). At day 7, eight (23.5%) patients in the LPV/r group, 3 (8.6%) in the arbidol group and 2(11.8%) in the control group showed a deterioration in clinical status from moderate to severe/critical(P =0.206). Overall, 12 (35.3%) patients in the LPV/r group and 5 (14.3%) in the arbidol group experienced adverse events during the follow-up period. No apparent adverse event occurred in the control group.ConclusionsLPV/r or arbidol monotherapy present little benefit for improving the clinical outcome of patients hospitalized with mild/moderate COVID-19 over supportive care.FundingThis study was supported by project 2018ZX10302103-002, 2017ZX10202102-003-004 and Infectious Disease Specialty of Guangzhou High-level Clinical Key Specialty (2019-2021).

The laser triggered sampling method and the fourier interpolative sampling method based on the Brault algorithm are compared. The results show that the fourier interpolative sampling method has lower detection limit and better detection accuracy.

A novel triple-component TiO2/Ag3PO4/graphene oxide (TiO2/Ag3PO4/GO) photocatalyst with dual channels for photo-generated charges separation has been synthesized to improve the photocatalytic activity and stability of Ag3PO4 under visible light. The synthesis involved in-situ growth of Ag3PO4 nanoparticles on GO sheets to form Ag3PO4/GO, and then deposited TiO2 nanocrystals on the surface of Ag3PO4 by hydrolysis of Ti(SO4)2 at low-temperature hydrothermal condition. The TiO2/Ag3PO4/GO exhibited superior photocatalytic activity and stability to bare Ag3PO4, TiO2/Ag3PO4 and Ag3PO4/GO in degradation of Rhodamine B and phenol solutions under visible light. It is suggested that the photo-generated electrons in the conduction band of Ag3PO4 can be quickly transferred to GO, while the holes in the valence band of Ag3PO4 can be transferred to the valence band of TiO2. The dual transfer channels at the interfaces of TiO2/Ag3PO4/GO result in effective charges separation, leading to enhanced photocatalytic activity and stability. Furthermore, the content of noble metal Ag significantly reduces from 77 wt% in bare Ag3PO4 to 55 wt% in the nanocomposite. The concept of establishing dual channels for charges separation in a triple-component heterostructure provides a promising way to develop photocatalysts with high efficiency.

Pure and Y-doped LiCoPO 4 samples are prepared by a citric acid-based sol–gel route followed by heat treatment. X-ray diffraction, scanning electron microscopy and charge–discharge tests show that a small amount of Y 3 + doping can significantly improve the capacity delivery and cycling properties of LiCoPO 4 without affecting its structural properties. Y-doped LiCoPO 4 ( x = 0.01) cathode material presents a high discharge capacity of 154.3 mAh g − 1 (0.1 C) at room temperature. Cyclic voltammetric and electrochemical impedance spectra tests disclose that the Li-ion diffusion, the reversibility of lithium extraction/insertion, electrical conductivity and electrochemical reaction are significantly improved in Y-doped LiCoPO 4 .

A facile and efficient one-step hydrothermal approach has been developed to synthesize chemically bonded TiO2/reduced graphene oxide (RGO) nanocomposites with Ti(SO4)2 and graphene oxide (GO) as precursors and ethanol/water solvent as a reducing agent. This approach aims to realize a partial reduction of GO and a growth of anatase TiO2 nanoparticles on RGO sheets simultaneously. The morphology and microstructure characterizations of TiO2/RGO nanocomposites reveal that this method leads to close interfacial contact of TiO2/RGO and efficient dispersion of TiO2 nanocrystals on the surface of RGO sheets. The TiO2/RGO nanocomposites exhibit superior photocatalytic activity compared to bare TiO2 nanoparticles and a mechanical mixing TiO2 + RGO sample in the degradation of Rhodamine B. Based on the photoluminescence spectrum and photocurrent response measurements, the enhanced photocatalytic activity of TiO2/RGO is mainly attributed to the excellent electron trapping and transportation properties of RGO.

Two thermophilic β-mannanases (ManA and ManB)were successfully expressed in Yarrowialipolytica using vector pINA1296I. The sequences of manA from Aspergillus niger CBS 513.88 and manB from Bacillus subtilis BCC41051 were optimized based on codon-usage bias in Y.lipolytica and synthesized by overlapping polymerase chain reaction (PCR). We utilized the pINA1296I vector, which allows inserting and expression of multiple copies of an expression cassette, to engineer recombinant strains containing multiple copies of manA or manB. Following verification of target-gene expression by quantitative PCR, fermentation experiments indicated that recombinant protein levels and enzyme activity increased along with increasing manA/manB copy number.After production in a 10 l fermenter, we obtained maximum enzyme activity from strains YLA6 and YLB6 of3024 U/mL and 1024 U/mL, respectively. Additionally, purification and characterization results revealed that the optimum pH and temperature for manA activity were pH∼5 and ∼70 °C, and for manB activity were pH∼7 and 60 °C, respectively. These results indicated that the thermo stabilities of these two enzymes were higher than most other mannanases, making them potentially useful for industrial applications.

For studing the yield and spatial distributions of protons produced in the interaction of femtosecond laser with plasmas, protons behavior at the normal direction of the rear surface of the target irradiated by ultra-intensity pulse laser irradiated solid targets was explored on SILEX-I laser facility. The yield and spatial distributions of the protons with different target thicknesses were recorded by radiochromic film (RCF) HD810. The results show that the optics density (OD) is closely correlated with the protons flux, OD values increase with the increasing of proton beam flux;For fixed thickness of C8H8 layer, the proton beam flux and yield of protons and OD of RCF decrease with the increasing Cu layer thickness;for the same thickness of targets, the OD and yield of protons decrease with the decreases of laser intensity;And the corresponding spatial profile of proton beam shows ring-, filament-, and disc-like distribution. The size of the distribution is independent of laser focus.

Recombinant “all-fish” growth hormone gene (GH) was microinjected into the fertilized eggs of carp. A comparison between the growth traits of transgenics and non-transgenics was carried out, and the transgenic individuals with significant “fast-growing” effect were successfully gained. A comparison on the reproductivities was also given out between the transgenics and their non-transgenic siblings, and showed that the reproductive capacity of transgenics was substantially equivalent to those of the non-transgenics. On the other hand, the genetic separation and the characteristic distribution of the F1 generation were genetically analyzed, which gave solid evidence for the hypothesis that 2–3 chromosomes are integrated with transgene. In addition, the distinct biological effects for multisite-integrated transgenes were further discussed. The present study opens a door for the breeding of “fast-growing” transgenic fish.

A DR300 Broad Band ADCP mounted on a vessel moving at a speed of 2–3 m/s was used to measure the profile of suspended sediment concentrations (SSCs) at the entrance to Jiaozhou Bay, Shandong Peninsula, where the water is characterized by low SSCs. The echo intensity data produced by the ADCP were regressed against the SSCs derived using the filtration method. The results show that the calibrated relationship can be used to calculate the SSC, with a relative error of 30%. Therefore, it is feasible to measure the SSC (even if the concentration is low) using the ADCP mounted on a moving vessel. Compared with OBS, ABS and other instruments for SSC measurements, the ADCP represents a potentially powerful tool to retrieve SSC data in continental shelf waters.

Introduction of a design processes and methods of high-speed stamping equipment status monitoring and controlling system in steel ball production. The using of self-developed shock force sensor to detect the steel ball size whether meet the requirements, stamping equipment running status whether is normal; the using of innovative design eddy current flaw detection sensor which is used on-line to detect defects of the steel ball materials, to effectively control the quality of the steel ball; the using of special signal processing modules and embedded computer systems to achieve real-time sensor signal acquisition and processing, to quickly and accurately determine the status of equipment operation and product quality; the using of a pneumatic schematic design of the products qualified for high-speed sorting institutions to realize the pass rate of steel ball sorting. Experiment is proved that the system can be effectively monitor the status of high-speed stamping equipment and to be achieved the separation of the steel ball which is above 98% pass rate, the control system is stable and reliable.

The yeast vectors described, pYEV and pYEVB, were designed for parallel polymerase chain reaction (PCR) cloning of open reading frames (ORFs) and immediate protein expression in Pichia pastoris. The pYEV vector was used to clone PCR fragments obtained by using Taq or similar polymerase mixes, which leave an A-base overhang. The other vector pYEVB, with the same features for blunt-end ligation of PCR products, was developed to be complementary to pYEV. These two plasmids were linearized using the restriction enzymes BfuI and SchI, respectively. The purified PCR products, without any other treatments, were cloned into the linearized vectors, followed by selection on plates supplemented with X-gal. Only desired recombinants carrying the target gene in the correct orientation can give typical blue colonies. This screening technique is based on a lacO reconstruction strategy that can produce a full-length lacO to exhaust endogenous LacI and switch on the transcription of lacZ in the host. The recombinant plasmids extracted from the blue colonies can be linearized by SalI and transformed into P. pastoris for immediate expression. By using these two vectors, researchers could be saved from the tedious and time-consuming conventional cloning procedures.