Identification and Antibacterial Activity Study of a Terrestrial Strain of Brevibacterium aureus 431

This study isolated and purified strain 431 from an animal probiotic product.Through staining and microscopic examination,colony morphology analysis,biochemical reaction tests,and 16S rDNA sequence alignment,the strain was identified and named Brevibacterium aureus 431.The study focused on the production of biosurfactants by strain 431,and antibacterial activity tests were conducted on the strain and its secondary metabolites.The results showed that strain 431 exhibited no resistance to 10 commonly used drugs,and its concentrated secondary metabolites were highly sensitive to the indicator bacterium Escherichia coli.Oral administration of strain 431 to BALB/c mice resulted in normal mental state,diet,and bowel movements,with no signs of illness or death,indicating that strain 431 is highly safe and non-pathogenic to mice.The study suggests that Brevibacterium aureus 431 has significant research value as a new source of actinomycetes and that its secondary metabolites have potential application value in the development of antibacterial drugs.

A method for preventing hydrates from blocking flow during deep-water gas well testing

Based on the research of the formation mechanism and evolution rule of hydrate flow obstacle during deep-water gas well testing,a new method for the prevention of hydrate flow obstacle based on safety testing window is proposed by changing the previous idea of"preventing formation"to the idea of"allowing formation,preventing plugging".The results show that the effective inner diameter of the testing tubing and the wellhead pressure decrease gradually with the formation and precipitation of hydrates during deep-water gas well testing,and it presents three typical processes of slow,fast and sudden changes.There is a safety testing window during deep-water gas well testing.The safety testing window of deep-water gas well testing decreases first and then increases with the increase of gas production rate,and increases with the increase of hydrate inhibitor concentrations.In the case with different testing production rates,a reasonable testing order with alternate low and high gas production rates has been proposed to further reduce the dosage of hydrate inhibitor and even avoid the use of hydrate inhibitors considering the decomposition and fall-off of hydrates.Compared with the traditional methods,the new method based on safety testing window can reduce the dosage of hydrate inhibitor by more than 50%.

Food safety testing by negentropy-sorted kernel independent component analysis based on infrared spectroscopy

In the field of food safety testing,variety,brand,origin,and adulteration are four important factors.In this study,a novel food safety testing method based on infrared spectroscopy is proposed to investigate these factors.Fourier transform infrared spectroscopy data are analyzed using negentropy-sorted kernel independent component analysis(NS-kICA)as the feature optimization method.To rank the components,negentropy is performed to measure the non-Gaussian independent components.In our experiment,the proposed method was run on four datasets to comprehensively investigate the variety,brand,origin,and adulteration of agricultural products.The experimental results show that NS-kICA outperforms conventional feature selection methods.The support vector machine model outperforms the backpropagation artificial neural network and partial least squares models.The combination of NS-kICA and support vector machine(SVM)is the best method for achieving high,stable,and efficient recognition performance.These findings are of great importance for food safety testing.

Separation and Preliminary Identification of Intestinal Probiotics of Laying Hens

[Objective] The paper was to isolate and identify probiotics in the intestine of laying hens. [Method] The intestinal probiotics in laying hens at peak period were isolated using conventional separation methods; the physical and chemical properties of target strains and in vitro antibacterial effects were measured. Moreover, the safety test of chicks was conducted. [Result] Four strains of lactobacillus were isolated from the jejunum of laying hens, including Lactobacillus plantarum, Bacillus acidophilus, L. delbrueckii subsp. Delbrueckii and L. delbrueckii subsp. Lactis, and their inhibition zone diameters were 18.30, 16.07, 11.45, 17.26 mm, respectively. One strain of Lactobacillus, L. brevis, was isolated from the cecum, with the inhibition zone diameter of 10.26 mm. Three strains of bacillus were isolated from the cecum, including Bacillus subtilis, B. cereus and B. licheniformis, and their inhibition zone diameters were 9.25, 8.46 and 8.37 mm, respectively. Daily drinking 2 billion units of viable bacteria was the safe dosage for chicks. [Conclusion] Eight strains of probiotics had certain inhibitory effect on Escherichia coli O;, and had no toxic side effects to chicks. Lactobacillus had strong antibacterial effect on E. coli O;, while the antibacterial effect of bacillus was relatively weak.

Critical analysis of ineffective post implantation implantable cardioverter-defibrillator-testing

AIM To test of the implantable-cardioverter-defibrillator is done at the time of implantation. We investigate if any testing should be performed.METHODS All consecutive patients between January 2006 and December 2008 undergoing implantable cardioverterdefibrillator(ICD) implantation/replacement(a total of 634 patients) were included in the retrospective study.RESULTS Sixteen patients(2.5%) were not tested(9 with LA/LVthrombus, 7 due to operator's decision). Analyzed were 618 patients [76% men, 66.4 + 11 years, 24% secondary prevention(SP), 46% with left ventricular ejection fraction(LVEF) < 20%, 56% had coronary artery disease(CAD)] undergoing defibrillation safety testing(SMT) with an energy of 21 + 2.3 J. In 22/618 patients(3.6%) induced ventricular fibrillation(VF) could not be terminated with maximum energy of the ICD. Six of those(27%) had successful SMT after system modification or shock lead repositioning, 14 patients(64%) received a subcutaneous electrode array. Younger age(P = 0.0003), non-CAD(P = 0.007) and VF as index event for SP(P = 0.05) were associated with a higher incidence of ineffective SMT. LVEF < 20% and incomplete revascularisation in patients with CAD had no impact on SMT.CONCLUSION Defibrillation testing is well-tolerated. An ineffective SMT occurred in 4% and two third of those needed implantation of a subcutaneous electrode array to passa SMT > 10 J.

Efficacy and Phytotoxicity Trial of Different Dosages of 4% Nicosulfuron SC on Weeds in Corn Fields

[Objective]The paper was to study efficacy and phytotoxicity of different dosages of 4% nicosulfuron on weeds in corn fields.[Method]With summer corn variety Zhengdan 958commonly used in field production in Hengshui area of Hebei Province of China as the test material,different dosages（1 050,1 500 and 1 950mL/hm2）of corn postemergence herbicide 4% nicosulfuron SC were sprayed during five-leaf stage of corn,and the treatments with water spraying and manual weeding were set as controls.The effects of different dosages of 4% nicosulfuron SC on weed control efficacy and safety and yield of corn were analyzed in order to determine the optimal dosage.[Result]Spraying 4% nicosulfuron SC with dosage of 1 500mL/hm2 during five-leaf stage of corn not only had better control effect against various weeds,but also did not produce phytotoxicity on corn,and the yield of corn was higher.[Conclusion]The study provided scientific information for using 4% nicosulfuron to eradicate weeds in corn fields.

SIMULATION TESTS INITIATE PASSIVE SAFETY STUDY

Two simulation crash tests were carried out in Tianjin and Shanghai respectively with a domestically developed setup and a imported system. Both are for their first time in China. Through more than 3 year’s efforts and with the assistance of UNDP (United Nations Development Programme) Beijing, CATARC has established its simulation crash test setup for auto components. This setup is the first such kind of equipment developed in China, and it consists of catapult, energy absorption system, measurement system, high-speed camera, film analysis system, TNO-10 Dummy and HybridⅡ Dummy. The setup can be used to carry out

High conductivity polymer electrolyte with comb-like structure via a solvent-free UV-cured method for large-area ambient all-solid-sate lithium batteries

A novel solid polymer electrolyte with comb-like structure is prepared via a solvent-free UV-cured method.The relationship between conductivity and molecular weight is investigated and revealed.The optimal electrolyte presents a considerably high conductivity of 1.44·10^(-4)S·cm^(-1)at 30℃.Meanwhile,it shows excellent compatibility with metallic lithium and wide electrochemical window(>5 V).To investigate the safety and cycling performance,the coin cell and soft package battery are assembled respectively.The LiFePO_(4)/Li coin cells exhibit initial discharge specific capacities of 163.2,147.7,137.3 and 108.7 mA·h·g^(-1)at 0.1,0.2,0.5 and 1C under 60℃,respectively.Notably,when the coin cells work at 30℃,the initial discharge specific capacities at 0.05,0.1,0.2 and 0.5C are 140.5,133.5,107.7 and 55.6 mA·h·g^(-1).Significantly,a 3.5 cm×7 cm solid-state soft pack battery is fabricated and cycling at 30℃.The first discharge capacity reaches to 137.5 mA·h·g^(-1)and the capacity retention is as high as 84.4%after 100 cycles at 0.2C and remain 95.5%after 100 cycles at 0.5C,respectively.These results shows a promising solid polymer electrolyte for solid-state batteries with good cycling and safety performance.

Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data

Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle （DHDV） was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit （IMU）. The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with ki- nematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance （ANOVA） test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis.