Decreased plasma ELABELA level as a novel screening indicator for heart failure: a cohort and observational study.

The predictive power of B-type natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) is limited by its low specificity in patients with heart failure (HF). Discovery of more novel biomarkers for HF better diagnosis is necessary and urgent. ELABELA, an early endogenous ligand for the G protein-coupled receptor APJ (Apelin peptide jejunum, Apelin receptor), exhibits cardioprotective actions. However, the relationship between plasma ELABELA and cardiac function in HF patients is unclear. To evaluate plasma ELABELA level and its diagnostic value in HF patients, a total of 335 patients with or without HF were recruited for our monocentric observational study. Plasma ELABELA and Apelin levels were detected by immunoassay in all patients. Spearman correlation analysis was used to analyze the correlation between plasma ELABELA or Apelin levels and study variables. The receiver operating characteristic curves were used to access the predictive power of plasma ELABELA or Apelin levels. Plasma ELABELA levels were lower, while plasma Apelin levels were higher in HF patients than in non-HF patients. Plasma ELABELA levels were gradually decreased with increasing New York Heart Association grade or decreasing LVEF. Plasma ELABELA levels were negatively correlated with BNP, left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular posterior wall thickness and positively correlated with LVEF in HF patients. In contrast, the correlation between plasma Apelin levels and these parameters is utterly opposite to ELABELA. The diagnostic value of ELABELA, Apelin, and LVEF for all HF patients was 0.835, 0.673, and 0.612; the sensitivity was 62.52, 66.20, and 32.97%; and the specificity was 95.92, 67.23, and 87.49%, respectively. All these parameters in HF patients with preserved ejection fraction were comparable to those in total HF patients. Overall, plasma ELABELA levels were significantly reduced and negatively correlated with cardiac function in HF patients. Decreased plasma ELABELA levels may function as a novel screening biomarker for HF. A combined assessment of BNP and ELABELA may be a good choice to increase the accuracy of the diagnosis of HF.

Development of an attenuated potato virus Y mutant carrying multiple mutations in helper-component protease for cross-protection.

Tobacco (Nicotiana tabacum) is one of the major cash crops in China. Potato virus Y (PVY), a representative member of the genus Potyvirus, greatly reduces the quality and yield of tobacco leaves by inducing veinal necrosis. Mild strain-mediated cross-protection is an attractive method of controlling diseases caused by PVY. Currently, there is a lack of effective and stable attenuated PVY mutants. Potyviral helper component-protease (HC-Pro) is a likely target for the development of mild strains. Our previous studies showed that the residues lysine at positions 124 and 182 (K124 and K182) in HC-Pro were involved in PVY virulence, and the conserved KITC motif in HC-Pro was involved in aphid transmission. In this study, to improve the stability of PVY mild strains, K at position 50 (K50) in KITC motif, K124, and K182 were separately substituted with glutamic acid (E), leucine (L), and arginine (R), resulting in a triple-mutant PVY-HCELR. The mutant PVY-HCELR had attenuated virulence and did not induce leaf veinal necrosis symptoms in tobacco plants and could not be transmitted by Myzus persicae. Furthermore, PVY-HCELR mutant was genetically stable after six serial passages, and only caused mild mosaic symptoms in tobacco plants even at 90 days post inoculation. The tobacco plants cross-protected by PVY-HCELR mutant showed high resistance to the wild-type PVY. This study showed that PVY-HCELR mutant was a promising mild mutant for cross-protection to control PVY.

Effect of guar gum, gelatin, and pectin on moisture changes in freeze-dried restructured strawberry blocks.

This study aimed to investigate the effects of edible gum addition on moisture changes in freeze-dried restructured strawberry blocks (FRSB), which involved five groups: the control, 1.2% guar gum, 1.2% gelatin, 1.2% pectin, and the composite group with 0.5% guar gum, 0.5% gelatin, and 0.45% pectin. The results indicated that the drying rates of the five groups of FRSB presented similar early acceleration and later deceleration trends. Moisture content in FRSB was linearly predicted by peak area of low field nuclear magnetic resonance with R2 higher than 0.90 for all the five groups. The FRSB samples in the gelatin and composition groups formed a denser porous structure and had a lower hygroscopicity after four days of storage. This study provides a theoretical basis for controlling the processing of FRSB.

Generation of High-Quality African Swine Fever Virus Complete Genome from Field Samples by Next-Generation Sequencing.

African swine fever (ASF) is a lethal contagious viral disease of domestic pigs and wild boars caused by the African swine fever virus (ASFV). The pandemic spread of ASF has caused severe effects on the global pig industry. Whole-genome sequencing provides crucial information for virus strain characterization, epidemiology analysis and vaccine development. Here, we evaluated the performance of next-generation sequencing (NGS) in generating ASFV genome sequences from clinical samples. Thirty-four ASFV-positive field samples including spleen, lymph node, lung, liver and blood with a range of Ct values from 14.73 to 25.95 were sequenced. For different tissue samples collected from the same sick pigs, the proportion of ASFV reads obtained from the spleen samples was 3.69-9.86 times higher than other tissues. For the high-viral-load spleen samples (Ct < 20), a minimum of a 99.8% breadth of ≥10× coverage was revealed for all the samples. For the spleen samples with Ct ≥ 20, 6/12 samples had a minimum of a 99.8% breadth of ≥10× coverage. A high average depth of sequencing coverage was also achieved from the blood samples. According to our results, high-quality ASFV whole-genome sequences could be obtained from the spleen or blood samples with Ct < 20. The high-quality ASFV genome sequence generated in this study was further used for the high-resolution phylogenetic analysis of the ASFV genomes in the early stage of the ASF epidemic in China. Our study demonstrates that NGS may act as a useful tool for efficient ASFV genome characterization, providing valuable information for disease control.

Changes and correlation analysis of volatile flavor compounds, amino acids, and soluble sugars in durian during different drying processes.

Durian contains rich flavor components that undergo complex changes during drying. In this study, durian was subjected to integrated freeze-drying (IFD), conventional freeze-drying (CFD), and hot air drying (AD). Compared with the fresh samples, those dried by IFD, CFD, and AD lost 11, 9, and 7 original volatile compounds, respectively, and generated 7, 6, and 8 new volatile compounds, respectively, and showed a rapid and then slow decreasing trend in the total content during drying. However, the types of amino acids and soluble sugars remained unchanged during each of the drying methods. Furthermore, volatile compounds showed a significant negative correlation with the majority of amino acids and a significant positive correlation with soluble sugars. The IFD samples had the highest content of volatile compounds, amino acids, and soluble sugars. Therefore, IFD is recommended as a preferable drying method for durian.

First Report of Penicillium subrubescens Causing Root Rot of Knoxia roxburghii in China.

Knoxia roxburghii (syn. Knoxia valerianoides), locally known as 'Zi Daji', is a perennial herb that belongs to the Rubiaceae family, cultivated in different areas of China and recognized for its medicinal properties in traditional Chinese medicine (Chen et al. 2022). In 2021, root rot was observed during summer on K. roxburghii in Xiangyun and Dali, Yunnan Province (25°25'N, 100°40'E), China. Root rots were characterized by dark brown tissue from stem base to root, loss of vitality in tender leaves and wither. Three symptomatic root samples of K. roxburghii collected from different fields were rinsed with running water, and 0.5-1 cm2 fragments of diseased tissues were cut and surface-disinfested with 75% ethanol for 30 s, and 1% NaClO for 180 s. The fragments were then washed with sterile water, transferred to potato dextrose agar (PDA, 4.6%) and incubated at 28℃ in the dark for 3 days. A total of 13 isolates with consistent appearances were obtained by single spore isolation. These colonies on PDA showed gray and light brown obverse, and light green reverse after 10 days. The average growth rate was 3 mm per day. Conidia were nearly spherical or broadly elliptic, greyish-green, and 1.4-2.4×1.3-2.2 µm in size (n=50). The conidiophore has symmetrical or asymmetrical broom branches from the tip, with 2-4 small stems. The conidiophore branching patterns were predominantly biverticillate; stipes coarsely roughened, 80-210×2.6-3.0 µm; metulae were usually appressed verticils of 3-6, 6.4-12.5×1.6-3.0 µm; phialides were short and wide neck, 3.8-4.8×1.1-1.8 µm (n=30). The morphological characteristics of the fungus were identical to Penicillium (Mansouri et al. 2013). To further identify the isolate, one isolate (ByF10) was randomly selected for identification. DNA was extracted from mycelia using a simplified CTAB method. Primer pairs, ITS1/ITS4 and Bt2a/Bt2b were used to amplify the partial regions of rDNA internal transcribed spacer (ITS) and ß-tubulin (TUB), respectively (White et al. 1990; Glass and Donaldson 1999). Blast searches showed that the sequences of ITS (OQ954757) and TUB (OQ970059) of isolate ByF10 were 99% (MH865456) and 100% (KC797611) identical with P. subrubescens CBS 130205 and CBS 129617, respectively. A concatenated phylogenetic tree (ITS+TUB) constructed using the maximum likelihood method showed that ByF10 was closely grouped next to isolates of P. subrubescens. Pathogenicity test was carried out using 1-year-old healthy seedlings of K. roxburghii cv. Yunji-1 growing on autoclaved soil (n=10). Ten plants were inoculated with mycelial blocks (5 mm2), which were taken from the colony margins of a 10-day-old culture (PDA) colony, and placed on the roots near the soil. Five control plants were inoculated with non-colonized PDA plugs. The pathogenicity test was repeated three times. All plants were kept at 25℃, 70% relative air humidity, and 12 h light/12 h regime dark for 35 days. After that period 95% of inoculated plants showed typical symptoms of root browning. P. subrubescens was only re-isolated from the inoculated plants, and identified based on morphological and molecular characteristics. No symptoms were observed in the controls. To the best of our knowledge, this is the first report of P. subrubescens causing root rot on K. roxburghii in China and the world.

A novel triplex real-time PCR assay for the differentiation of lumpy skin disease virus, goatpox virus, and sheeppox virus.

Introduction: Three members of Capripoxvirus (CaPV) genus, including lumpy skin disease virus (LSDV), goatpox virus (GTPV), and sheeppox virus (SPPV), are mentioned as notifiable forms by World Organization for Animal Health. These viruses have negatively impacted ruminant farming industry worldwide, causing great economic losses. Although SPPV and GTPV cause more severe clinical disease in only one animal species, they can transfer between sheep and goats. Both homologous and heterologous immunization strategies are used to protect animals against CaPVs. However, development of accurate and rapid methods to distinguish these three viruses is helpful for the early detection, disease surveillance, and control of CaPV infection. Therefore, we developed a novel triplex real-time PCR (qPCR) for the differentiation of LSDV, GTPV, and SPPV. Methods: Universal primers were designed to detect pan-CaPV sequences. Species-specific minor groove binder (MGB)-based probes were designed, which were labeled with FAM for LSDV, HEX for GTPV, and ROX for SPPV. The sensitivity, specificity, reproducibility, and ability of detecting mixed infections were evaluated for the triplex qPCR. Further, 226 clinical samples of the infection and negative controls were subjected to the triplex qPCR, and the results were verified using PCR-restriction fragment length polymorphism (PCR-RFLP) and sequencing methods for PRO30 gene. Results: The triplex qPCR could successfully distinguish LSDV, GTPV, and SPPV in one reaction, and the assay sensitivity was 5.41, 27.70, and 17.28 copies/µL, respectively. No cross-reactivity was observed with other viruses causing common ruminant diseases, including des petits ruminants virus, foot-and-mouth disease virus, bluetongue virus, ovine contagious pustular dermatitis virus, infectious bovine rhinotracheitis virus, and bovine viral diarrhea-mucosal disease virus. Inter-and intra-assay variabilities were < 2.5%. The results indicated that the triplex qPCR was highly specific, sensitive, and reproducible. Simulation experiments revealed that this assay could successfully distinguish two or three viruses in case of mixed infections without any cross-reaction. For clinical samples, the results were completely consistent with the results of PCR-RFLP and sequencing. This demonstrated that the assay was reliable for clinical application. Discussion: The triplex qPCR is a robust, rapid, and simple tool for identifying various types of CaPV as it can successfully distinguish LSDV, GTPV, and SPPV in one reaction. Furthermore, the assay can facilitate more accurate disease diagnosis and surveillance for better control of CaPV infection.

Genetic variants, pathophysiological pathways, and oral anticoagulation in patients with hypertrophic cardiomyopathy and atrial fibrillation.

Atrial fibrillation (AF) is commonly prevalent in patients with hypertrophic cardiomyopathy (HCM). However, whether the prevalence and incidence of AF are different between genotype-positive vs. genotype-negative patients with HCM remains controversial. Recent evidence has indicated that AF is often the first presentation of genetic HCM patients in the absence of a cardiomyopathy phenotype, implying the importance of genetic testing in this population with early-onset AF. However, the association of the identified sarcomere gene variants with HCM occurrence in the future remains unclear. How the identification of these cardiomyopathy gene variants should influence the use of anticoagulation therapy for a patient with early-onset AF is still undefined. In this review, we sought to assess the genetic variants, pathophysiological pathways, and oral anticoagulation in patients with HCM and AF.

Changes in, and correlation analysis of, volatile compounds, key enzymes, and fatty acids in lemon juice vesicles during freeze drying and hot-air drying.

BACKGROUND: Lemon juice vesicles are distinguished by their unique and abundant volatile flavor compounds, which can undergo complex changes during drying. In this study, integrated freeze drying (IFD), conventional freeze drying (CFD), and hot-air drying (AD) were used to dry lemon juice vesicles to investigate the changes in, and correlations among volatile compounds, fatty acids, and key enzyme activity during the drying process. RESULTS: Twenty-two volatile compounds were detected during the drying processes. Compared with fresh samples, seven compounds were lost in the dried samples after IFD, seven after CFS, and six after AD, and the loss rates of the total content of volatile compounds in the dried samples were 82.73% in CFD, more than 71.22% in IFD, and more than 28.78% in AD. In total, 1.015 mg/g of seven fatty acids were detected in the fresh samples; the content loss rates of total fatty acids after drying were 67.68% in AD, more than 53.00% in CFD, and more than 36.95% in IFD, respectively. During the three drying processes, IFD retained relatively higher enzyme activity in the samples. CONCLUSION: Many positive and negative correlations (P < 0.05) were observed among the key enzyme effects, fatty acids, and volatile compounds, showing close associations. The current work provides information that is important for the selection of suitable drying techniques for lemon juice vesicles and suggests how to control their flavor during the drying process. © 2023 Society of Chemical Industry.

Edible gum addition improves the quality of freeze-dried restructured strawberry blocks.

Freeze-dried restructured strawberry blocks (FRSB) have become an increasingly popular product. In this study, the effects of six edible gums (guar gum, gelatin, xanthan gum, pectin, konjac gum, and carrageenan) on the FRSB quality were investigated. For FRSBs, compared with those in untreated samples, the 0.6 % guar gum addition increased texture profile analysis (TPA) hardness, chewiness, and puncture hardness by 29.59%, 174.86%, and 25.34%, respectively; after the 0.6% gelatin addition, the sensory evaluation sourness was reduced by 8.58%, whereas yield, TPA chewiness, and puncture hardness were increased by 3.40%, 28.62%, and 92.12%, respectively; with the 0.9% gelatin addition, the sensory evaluation sourness was reduced by 8.58%; with the 0.9% pectin addition, the yield, TPA hardness, chewiness, and puncture hardness were increased by 4.55%, 5.94%, 77.49%, and 103.62%, respectively. In summary, 0.6-0.9% pectin, gelatin, and guar gum addition are recommended to improve the main qualities of FRSBs.

Optimization of Conditions for a Freeze-Dried Restructured Strawberry Block by Adding Guar Gum, Pectin and Gelatin.

With its high moisture content and tender texture, fresh strawberry is very susceptible to mechanical damage and microbial infection. Drying is one of the most frequently employed methods to extend its shelf life, and freeze-dried restructured strawberry block (FRSB) is an emerging popular food. Here, in order to enhance the quality of FRSB, edible gums of guar gum, pectin, and gelatin were added and the combination was optimized using response surface methodology (RSM) with chewiness, hardness, and organoleptic evaluations of the dried sample as the response indicators. The results showed that the combination addition of 0.10% guar gum, 0.22% pectin, and 0.30% gelatin contributed to the highest comprehensive quality of the dried sample. Compared with the untreated sample, the optimal combination addition of the three edible gums resulted in a higher moisture content for the dried sample (increased by 0.8%), and increased the chewiness, hardness, and porosity by 82.04%, 27.09%, and 3.01%, respectively, while maintaining more original color and forming a denser porous microstructure. The findings in the current work will be useful for the application of edible gums in freeze-dried restructured fruits and vegetables.

Characterization of aroma-active compounds in Dongli by quantitative descriptive analysis, gas chromatography-triple quadrupole tandem mass spectrometry, and gas chromatography-olfactometry.

Dongli, or frozen pear, is a traditional Chinese snack with a unique flavor. This study identified the aroma-active volatile compounds (VOCs) in Dongli using quantitative descriptive analysis (QDA), gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS), and gas chromatography-olfactometry (GC-O). QDA indicated that Dongli of all cultivars presented increased sweet and wine aromas. A total of 21 VOCs were identified by GC-MS/MS. Bidirectional orthogonal partial least square (O2PLS) analysis, GC-O analysis, detection frequency analysis (DFA), and relative odor activity values (ROAV) showed that: estragole and anethole contributing "anise, green" aromas were the key aromatic VOCs of fresh pears, while ethyl butanoate, butyl acetate, heptyl acetate, benzaldehyde, and geranyl acetone contributing "sweet, fruity, green" aromas were the key aromatic VOCs of Dongli. The results revealed that the repeated freezing treatment promoted a unique aroma in pears. This study would contribute to developing new pear products. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05463-8.

Hepatic inhibitors expression profiling of venom-challenged Sinonatrix annularis and antidotal activities.

Snake venom is considered a "toxin arsenal", and it often induces a series of clinical and pathophysiological symptoms in snakebite victims. Interestingly, toxin inhibitors are commonly found in the serum of snakes and their predators. Sinonatrix annularis is a type of non-venomous snake that was reported to contain an "inhibitor cocktail", including phospholipase A2 inhibitors (PLIs), metalloproteinase inhibitors (SVMPIs), and small serum protein (SSP). However, the sequences and activities of these components remain obscure. In this study, we performed envenomation challenges on S. annularis using venoms from Deinagkistrodon acutus, Agkistrodon halys and Naja atra. In brief, the maximum injected amount of venom was 360 mg/kg for D. acutus, 72 mg/kg for A. halys, and 18 mg/kg for N. atra. The mRNA expression of the inhibitors PLIα, PLIß, PLIγ, SVMPI, serpin A1, and SSP showed a dose-dependent effect on envenomation. Liver homogenate from S. annularis (LH) was prepared and used to evaluate its inhibitory effect on snake venoms. As a result, LH showed significant neutralization of venom PLA2, mitigated hemorrhage, venom-induced muscle damage, and system toxicity. In the presence of LH, envenomated mice exhibited attenuated inflammation, apoptosis, oxidative damage, and mitigated changes in serum biochemical markers caused by venom. The study reveals the secret of "natural immunity" in snakes, namely, the "antivenom", which consists of an inhibitor proteome or cocktail.

Dynamic Changes in Volatile Flavor Compounds, Amino Acids, Organic Acids, and Soluble Sugars in Lemon Juice Vesicles during Freeze-Drying and Hot-Air Drying.

Lemon juice vesicles have abundant flavor components that can undergo complex changes during drying. Three drying methods, including integrated freeze-drying (IFD), conventional freeze-drying (CFD), and hot-air drying (AD), were studied to determine their effects on the dynamic changes in the flavor compounds in lemon juice vesicles. Compared with the fresh samples, the final dried samples that underwent IFD, CFD, and AD lost seven, seven, and six volatile flavor compounds and three, four, and five amino acids, respectively; the order of the loss ratios with respect to the volatile compound content was: 82.73% in CFD > 71.22% in IFD > 28.78% in AD. AD resulted in the highest total amino acid content (10.83 ± 0.20 mg/g), which was 1.39 and 5.54 mg/g higher than that of IFD and CFD, respectively; CFD resulted in the highest total organic acid content (45.94 ± 0.34 mg/g), which was 8.01 and 7.87 mg/g higher than that of IFD and AD, respectively; and AD contributed to the highest total soluble sugars (17.12 ± 0.20 mg/g), which was 1.24 and 1.49 mg/g higher than that of IFD and CFD, respectively. A correlation analysis demonstrated that most of the amino acids and the soluble sugars were closely related to the profiles of the volatile compounds in the lemon juice vesicles during drying.

The molecular basis of venom resistance in the non-venomous snake Sinonatrix annularis.

Various snake species and snake predators have natural neutralization against snake toxins, which their antidotal abilities are commonly attributed to the intrinsic inhibitors produced by the liver, e.g., phospholipase A2 inhibitor (PLI) and metalloproteinase inhibitor (SVMPI). Sinonatrix annularis was found to possess broad-spectrum neutralization to different snake venoms in our lab. Although the anti-venom compound PLIγ has been previously characterized in our laboratory, the mechanism of resistance of S. annularis to snake venoms remains obscure. In this research, a venom affinity chromatography was constructed by immobilizing D. acutus venom to NHS-agarose beads and applied for antitoxins mining from S. annularis. The binding capacity of the venom column was validated using a self-prepared rabbit antivenom against D. acutus. Serum and liver homogenate of S. annularis were then applied to the column, the bound components were profiled using SDS-PAGE and mass spectrometry. PLIs, snake venom metalloproteins inhibitor (SVMPI), small serum protein (SSP), heat shock proteins, etc were identified. To identify their toxin targets in D. acutus venom, a reverse separation was conducted by coupling the fractionated S. annularis serum proteins to NHS-agarose beads. Fifteen toxins of five families were captured and identified as follows: PLA2s, metalloproteinases, cysteine-rich secretory proteins, snake venom serine proteinases, and C-type lectins. These discoveries increased our understanding of the capacity and mechanism of the natural neutralization of S. annularis to snake venom. These natural inhibitors are medically significant due to their powerful and broad antidotal activities, which may provide alternative and promising drug candidates for snakebite treatment.

Cardiovascular aspects of the (pro)renin receptor: Function and significance.

Cardiovascular diseases (CVDs), including all types of disorders related to the heart or blood vessels, are the major public health problems and the leading causes of mortality globally. (Pro)renin receptor (PRR), a single transmembrane protein, is present in cardiomyocytes, vascular smooth muscle cells, and endothelial cells. PRR plays an essential role in cardiovascular homeostasis by regulating the renin-angiotensin system and several intracellular signals such as mitogen-activated protein kinase signaling and wnt/ß-catenin signaling in various cardiovascular cells. This review discusses the current evidence for the pathophysiological roles of the cardiac and vascular PRR. Activation of PRR in cardiomyocytes may contribute to myocardial ischemia/reperfusion injury, cardiac hypertrophy, diabetic or alcoholic cardiomyopathy, salt-induced heart damage, and heart failure. Activation of PRR promotes vascular smooth muscle cell proliferation, endothelial cell dysfunction, neovascularization, and the progress of vascular diseases. In addition, phenotypes of animals transgenic for PRR and the hypertensive actions of PRR in the brain and kidney and the soluble PRR are also discussed. Targeting PRR in local tissues may offer benefits for patients with CVDs, including heart injury, atherosclerosis, and hypertension.

Mutation Profiles of eGFP-Tagged Small Ruminant Morbillivirus During 45 Serial Passages in Ribavirin-Treated Cells.

Small ruminant morbillivirus (SRMV), formerly known as peste-des-petits-ruminants virus, classified into the genus Morbillivirus in the family Paramyxoviridae. Its L protein functions as the RNA-dependent RNA polymerases (RdRp) during viral replication. Due to the absence of efficient proofreading activity in their RdRps, various RNA viruses reveal high mutation frequencies, making them evolve rapidly during serial passages in cells, especially treated with a certain mutagen, like ribavirin. We have previously rescued a recombinant enhanced green fluorescence protein-tagged SRMV (rSRMV-eGFP) using reverse genetics. In this study, the rSRMV-eGFP was subjected to serial passages in ribavirin-treated cells. Due to the ribavirin-exerted selective pressure, it was speculated that viral progenies would form quasispecies after dozens of passages. Viral progenies at passage-10, -20, -30, -40, and -50 were separately subjected to next-generation sequencing (NGS), consequently revealing a total of 34 single-nucleotide variations, including five synonymous, 21 missense, and one non-sense mutations. The L sequence was found to harbor eight missense mutations during serial passaging. It was speculated that at least one high-fidelity variant was present in viral quasispecies at passage-50. If purified from the population of viral progenies, this putative variant would contribute to clarifying a molecular mechanism in viral high-fidelity replication in vitro.

Effects of pre-drying treatments combined with explosion puffing drying on the physicochemical properties, antioxidant activities and flavor characteristics of apples.

The purpose of this research was to study the effect of hot air drying, microwave vacuum drying and freeze drying combined with explosion puffing drying (HDEPD, MDEPD and FDEPD) on physicochemical properties, antioxidant activities and flavor characteristics of apples. The results showed that MDEPD and FDEPD products had better color and textural properties, exhibited a homogeneous porous structure. MDEPD and FDEPD better preserved scavenging abilities of DPPH, hydroxyl radical and FRAP, retained values of TFC and TPC. Aroma characteristics and taste properties of apples obviously changed with different drying methods, and drying qualities of products could be classified in terms of volatile compounds and taste profiles. Two principal components were able to describe 90.12% and 69.43% of the total volatile compound variance and total taste profile variance, respectively. Three main clusters of dried apples were identified, MDEPD and FDEPD can be used to enhance drying qualities of apple products.

Clinical Validation of Two Recombinase-Based Isothermal Amplification Assays (RPA/RAA) for the Rapid Detection of African Swine Fever Virus.

African swine fever (ASF), caused by African swine fever virus (ASFV), is a devastating infectious disease of domestic pigs and wild boars, and has tremendous negative socioeconomic impact on the swine industry and food security worldwide. It is characterized as a notifiable disease by World Organisation for Animal Health (OIE). No effective vaccine or treatment against ASF has so far been available. Early detection and rapid diagnosis are of potential significance to control the spread of ASF. Recombinase-based isothermal amplification assay, recombinase polymerase amplification (RPA) developed by TwistDx (Cambridge, United Kingdom) or recombinase-aided amplification (RAA) by Qitian (Wuxi, China), is becoming a molecular tool for the rapid, specific, and cost-effective identification of multiple pathogens. In this study, we aim to investigate if RPA/RAA can be a potential candidate for on-site, rapid and primary detection of ASFV. A panel of 152 clinical samples previously well-characterized by OIE-recommended qPCR was enrolled in this study, including 20 weak positive (Ct value ≥ 30) samples. This panel was consisted of different types, such as EDTA-blood, spleen, lung, lymph node, kidney, tonsil, liver, brain. We evaluated two recombinase-based isothermal amplification assays, RPA or RAA, by targeting the ASFV B646L gene (p72), and validated the clinical performance in comparison with OIE real-time PCR. Our result showed that the analytical sensitivity of RPA and RAA was as 93.4 and 53.6 copies per reaction, respectively at 95% probability in 16 min, at 39°C. They were universally specific for all 24 genotypes of ASFV and no cross reaction to other pathogens including Classical swine fever virus (CSV), Foot-and-mouth disease virus (FMDV), Pseudorabies virus, Porcine circovirus 2 (PCV2), Porcine Reproductive and respiratory syndrome virus (PPRSV). The results on detection of various kinds of clinical samples indicated an excellent diagnostic agreement between RPA, RAA and OIE real-time PCR method, with the kappa value of 0.960 and 0.973, respectively. Compared to real-time PCR, the specificity of both RPA and RAA was 100% (94.40% ∼ 100%, 95% CI), while the sensitivity was 96.59% (90.36% ∼ 99.29%, 95% CI) and 97.73% (92.03% ∼ 99.72%, 95% CI), respectively. Our data demonstrate that the developed recombinase-based amplification assay (RPA/RAA), promisingly equipped with field-deployable instruments, offers a sensitive and specific platform for the rapid and reliable detection of ASFV, especially in the resource-limited settings for the purpose of screening and surveillance of ASF.

Multivariate analyses of the volatile components in fresh and dried turnip (Brassica rapa L.) chips via HS-SPME-GC-MS.

Turnip is a vegetable that has many health promoting effects. To diversify the usage and increase the consumption of turnip, the effects of hot air drying, infrared drying, explosion puff drying and freeze drying (FD) on the volatiles of turnip chips were studied. The volatiles of fresh turnip and dried turnip chips were isolated by HS-SPME-GC-MS and a total of 67 volatiles were identified. However, the volatiles in turnip chips dried by different methods are quite different. Based on principal component analysis and hierarchical cluster analysis, the volatiles of fresh turnip were distinguished from those of the dried chips and FD was separated from the other drying methods. As the result of orthogonal projection on latent structure-discriminant analysis (OPLS-DA), isothiocyanato-cyclopropane and (2-isothiocyanatoethyl)-benzene were identified as the characteristic volatiles of fresh turnip. While, 2-azido-2,3,3-trimethyl-butane and hexanal were identified as the characteristic volatiles for FD dried chips.