Analysis of contamination and pathogenic characteristics of Salmonella in the processing of pre-packed cooked meat products

ObjectiveTo analyze the molecular characteristics and antibiotic susceptibility of Salmonella isolates and investigate the contamination of Salmonella in pre-packed cooked meat products during food processing.MethodsAccording to the sampling requirements of the national “Manual for Monitoring the Production and Processing of Cooked Meat Products （Pre-packed）”， 460 environmental and cooked meat samples were collected from a pre-packed cooked meat product factory in Dezhou from 2015 to 2017. Salmonella isolation and identification were performed per the currently effective GB 4789.4—2016 protocol. Salmonella serotypes were determined based on serum agglutination. Pulsed field gel electrophoresis （PFGE） and multilocus sequence typing （MLST） were employed to determine the molecular types of Salmonella isolates. Resistance tests for 15 antibiotics were performed using the broth microdilution susceptibility test.ResultsThe detection rate of Salmonella in 460 samples was 5.65% （26/460）. The detection rate in 2016 was the highest （7.65%， 14/183）， and the difference among samples from different years was not statistically significant （χ2=2.82， P>0.05）. The detection rate in intermediate products was the highest， and the difference among samples from different samples was statistically significant （χ2=64.16， P<0.05）. Salmonella was detected only in the raw product workshop， and the difference among samples from different workshops was statistically significant （χ2=78.08， P<0.05）. Twenty-six strains of Salmonella were divided into six serotypes， with Salmonella enteritidis being the most prevalent， accounting for 53.85% （14/26）. Twenty-six isolates were subtyped into 12 PFGE types， with type S4 predominantly dominating. The 26 Salmonella strains were divided into five types based on MLST typing. ST11 was the major ST type. Of these 26 isolates， 22 were resistant to various antibiotics. The highest antibiotic resistance rate was for ampicillin， at 73.08% （19/26）， and the multiple antibiotic resistance rate （resistance to three or more antibiotics） was 73.08%.ConclusionDuring the processing of cooked meat products， Salmonella contamination is concentrated mainly in raw materials and intermediate products. The contamination status of the products after steaming was effectively controlled

Development and validation of a highly dynamic and reusable picture-based scale: A new affective measurement tool

Emotion measurement is crucial to conducting emotion research. Numerous studies have extensively employed textual scales for psychological and organizational behavior research. However, emotions are transient states of organisms with relatively short duration, some insurmountable limitations of textual scales have been reported, including low reliability for single measurement or susceptibility to learning effects for multiple repeated use. In the present article, we introduce the Highly Dynamic and Reusable Picture-based Scale (HDRPS), which was randomly generated based on 3,386 realistic, high-quality photographs that are divided into five categories (people, animals, plants, objects, and scenes). Affective ratings of the photographs were gathered from 14 experts and 209 professional judges. The HDRPS was validated using the Self-Assessment Manikin and the PANAS by 751 participants. With an accuracy of 89.73%, this new tool allows researchers to measure individual emotions continuously for their research. The non-commercial use of the HDRPS system can be freely accessible by request at http://syy.imagesoft.cc:8989/Pictures.7z. HDRPS is used for non-commercial academic research only. As some of the images are collected through the open network, it is difficult to trace the source, so please contact the author if there are any copyright issues

Age-Related Decline in the Variation of Dynamic Functional Connectivity: A Resting State Analysis

Normal aging is typically characterized by abnormal resting-state functional connectivity (FC), including decreasing connectivity within networks and increasing connectivity between networks, under the assumption that the FC over the scan time was stationary. In fact, the resting-state FC has been shown in recent years to vary over time even within minutes, thus showing the great potential of intrinsic interactions and organization of the brain. In this article, we assumed that the dynamic FC consisted of an intrinsic dynamic balance in the resting brain and was altered with increasing age. Two groups of individuals (N = 36, ages 20–25 for the young group; N = 32, ages 60–85 for the senior group) were recruited from the public data of the Nathan Kline Institute. Phase randomization was first used to examine the reliability of the dynamic FC. Next, the variation in the dynamic FC and the energy ratio of the dynamic FC fluctuations within a higher frequency band were calculated and further checked for differences between groups by non-parametric permutation tests. The results robustly showed modularization of the dynamic FC variation, which declined with aging; moreover, the FC variation of the inter-network connections, which mainly consisted of the frontal-parietal network-associated and occipital-associated connections, decreased. In addition, a higher energy ratio in the higher FC fluctuation frequency band was observed in the senior group, which indicated the frequency interactions in the FC fluctuations. These results highly supported the basis of abnormality and compensation in the aging brain and might provide new insights into both aging and relevant compensatory mechanisms

Theoretical Study on the Mechanism of Asymmetrical Large Deformation of Heading Roadway Facing Mining

The problem of asymmetric large deformation of surrounding rock of heading roadways is prominent due to the superposition of mining stress in the mining intersection area. Therefore, on the basis of the background of 18,106 tailentry in the Xiegou Coal Mine, this paper establishes a mechanical model of surrounding rock deformation of mining roadways under the effect of advanced abutment pressure. In the model, we deduce the theoretical calculation formula of roadway full-section deformation and discuss the influence factors of roadway surrounding rock deformation. Accordingly, the deformation mechanism of surrounding rock of mining roadways and the engineering suggestions and measures are revealed. The main results and finding are threefold. Firstly, the increase of the stress concentration factor of the coal pillar rib and the increase of the width of the failure zone are the fundamental reasons leading to the aggravation of the surrounding rock deformation on the side of the coal pillar in the heading roadway. Secondly, the deformation of the coal pillar rib increases with the increase of stress concentration factor and decreases with the increase of coal cohesion, internal friction angle, elastic modulus, and roadway rib support resistance. Additionally, the deformation of the roadway roof and floor decreases with the increase of roadway rib support resistance and is inversely proportional to the cubic power of rock beam thickness and elastic modulus. The deformation rate of the roadway roof and floor increases with the increase of vertical stress concentration factor of the coal pillar rib, and the maximum deformation position shifts to the side of the coal pillar. Therefore, increasing the strength and stiffness of the roadway surrounding rock and the supporting resistance of surrounding rock can reduce the deformation of roadway surrounding rock and the influence of advanced abutment pressure on roadway deformation. In the end, the rationality and feasibility of the theoretical analysis is verified through an engineering example. Under the influence of advanced abutment pressure, the deformation of roadway floor heave is the most severe, the asymmetrical deformation on both sides of the roadway is remarkable, and the deformation of coal pillar side is about twice that of solid coal side

An Albumin-Binding PSMA Ligand with Higher Tumor Accumulation for PET Imaging of Prostate Cancer

Prostate-specific membrane antigen (PSMA) is an ideal target for the diagnosis and treatment of prostate cancer. Due to the short half-life in blood, small molecules/peptides are rapidly cleared by the circulatory system. Prolonging the half-life of PSMA probes has been considered as an effective strategy to improve the tumor detection. Herein, we reported a 64Cu-labeled PSMA tracer conjugating with maleimidopropionic acid (MPA), 64Cu-PSMA-CM, which showed an excellent ability to detect PSMA-overexpressing tumors in delayed time. Cell experiments in PSMA-positive 22Rv1 cells, human serum albumin binding affinity, and micro-PET imaging studies in 22Rv1 model were performed to investigate the albumin binding capacity and PSMA specificity. Comparisons with 64Cu-PSMA-BCH were performed to explore the influence of MPA on the biological properties. 64Cu-PSMA-CM could be quickly prepared within 30 min. The uptake of 64Cu-PSMA-CM in 22Rv1 cells increased over time and it could bind to HSA with a high protein binding ratio (67.8 &plusmn; 1.5%). When compared to 64Cu-PSMA-BCH, 64Cu-PSMA-CM demonstrated higher and prolonged accumulation in 22Rv1 tumors, contributing to high tumor-to-organ ratios. These results showed that 64Cu-PSMA-CM was PSMA specific with a higher tumor uptake, which demonstrated that MPA is an optional strategy for improving the radioactivity concentration in PSMA-expressing tumors and for developing the ligands for PSMA radioligand therapy

Ultrasound-assisted Extraction and Physicochemical Properties of Starch from Cyperus esculentus Tubers

The purpose of this study was to use ultrasound-based extraction to prepare starch from the tubers of Cyperus esculentus. Ultrasonic treatment of Cyperus esculentus powder with a medium of alkaline-treated water can effectively improve the starch extraction efficiency. Box-Behnken design was used to optimize the extraction process, and the results showed that the optimal parameters were ultrasound time of 30 minutes, pH value of 9.0, ultrasound temperature of 40 °C, and solid-liquid ratio of 10:1. The extraction percentage under these conditions was 90.1%. The physicochemical properties of C. esculentus starch were compared with those of cassava, potato, and corn starch. The particle size of C. esculentus starch was approximately 2 to 15 μm. The gelatinization temperature was 70.5 °C, and the peak viscosity was similar to cassava but with better thermal stability. Like other tuber starches, C. esculentus starch had higher swelling power and solubility at 85 °C

A Melting Curve-Based Multiplex RT-qPCR Assay for Simultaneous Detection of Four Human Coronaviruses

Human coronaviruses HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1 are common respiratory viruses associated with acute respiratory infection. They have a global distribution. Rapid and accurate diagnosis of HCoV infection is important for the management and treatment of hospitalized patients with HCoV infection. Here, we developed a melting curve-based multiplex RT-qPCR assay for simultaneous detection of the four HCoVs. In the assay, SYTO 9 was used to replace SYBR Green I as the fluorescent dye, and GC-modified primers were designed to improve the melting temperature (Tm) of the specific amplicon. The four HCoVs were clearly distinguished by characteristic melting peaks in melting curve analysis. The detection sensitivity of the assay was 3 × 102 copies for HCoV-OC43, and 3 × 101 copies for HCoV-NL63, HCoV-229E and HCoV-HKU1 per 30 μL reaction. Clinical evaluation and sequencing confirmation demonstrated that the assay was specific and reliable. The assay represents a sensitive and reliable method for diagnosis of HCoV infection in clinical samples

Solar-Driven Soil Remediation along with the Generation of Water Vapor and Electricity

As a renewable energy source, solar energy has become an important part of human energy use. However, facilities utilizing solar energy are often complex and technically difficult, and preparation equipment and materials are expensive, while these equipment and materials often cause new environmental pollution. Soil, which exists in large quantities on the earth&rsquo;s surface, is an inexhaustible natural material with loose and stable properties. Due to the specificity of its composition and microscopic form, the soil has an inherent advantage as a medium for solar thermal and photovoltaic conversion. Here, we built an integrated solar energy utilization system, the Integrated Soil Utilization Module (ISUM), integrating multi-functions into one hybrid system, which enables solar-driven water vapor and electricity generation and soil remediation. The evaporation rate of the soil represented by the rocky land was 1.2 kg&middot;m&minus;2&middot;h&minus;1 under 1-sun irradiation with evaporation induced voltage of 0.3 V. With only seven days of continuous exposure to sunlight, the removal of heavy metal ions from the soil reached 90%, while the pH was raised to near neutral. The combined application of readily available natural soil with solar energy not only demonstrates the potential of a soil for solar desalination and power generation, but in addition, solar-driven interfacial evaporation provides an energy-efficient, environmentally friendly, and sustainable method for purifying heavy metal and acid-contaminated soil