Impact of ultra-high-pressure treatment on microbial community composition and flavor quality of jujube juice: Insights from high-throughput sequencing technology, intelligent bionic sensory system, and metabolomics approach.

Ultra-high-pressure (UHP1) technology for cold pasteurization is a viable alternative to traditional heat sterilization for preserving food nutrients and flavor compounds during fruit juice processing. In this study, cutting-edge techniques, including high-throughput sequencing technology, intelligent bionic sensory systems, and metabolomics, were used to examine the impact of UHP treatment on microbial community composition, odor, and taste quality of jujube juice. The UHP treatment demonstrated its effect by inducing a reddish-yellow color in the jujube juice, thereby enhancing its brightness, overall color, and stability. The most significant enhancement was observed at 330 MPa. The microorganisms responsible for spoilage and deterioration of jujube juice during storage were categorized into three clusters: bacterial clusters at 0-330 MPa, 360-450 MPa, and 480-630 Mpa. The results showed no distinct distribution patterns for fungi based on the pressure strength. The dominant bacterial genera were Lactobacillus, Nocardia, Achromobacter, Enterobacter, Pseudomonas, Mesorhizobium, and Rhodococcus, whereas the dominant fungal genera were yeast and mold. Notably, Lactobacillus, Achromobacter, Enterobacter, and Pseudomonas were responsible for the significant differences between the 360 MPa to 450 MPa and 480 MPa to 630 MPa clusters in terms of bacterial spoilage, whereas Torulaspora, Lodderomyces, Wickerhamomyces, and Fusarium were the primary fungal spoilage genera. UHP treatment exerted no significant impact on the taste of jujube juice but influenced its sourness. Treatment at 330 MPa had the most pronounced effect on the presence of aromatic compounds and other odorants, which were substantially increased. Further analysis revealed the prevalence of organic acids, such as malic acid, succinic acid, and tartaric acid, in jujube juice and demonstrated a consistent relationship between changes in organic acids and sourness. In addition, nine distinct odorants with VIP values greater than 1 were identified in the jujube juice. Among these, methyl acetate and methyl caproate exhibited substantial increases following the UHP treatment at 330 MPa.

Comparative analysis of bacterial community structure and physicochemical quality in high-temperature Daqu of different colors in Qingzhou production area.

To compare the effects of differences in Daqu making technology and production regions on the bacterial composition and physicochemical properties of high-temperature Daqu (HTD), this study analyzed the bacterial community structure of three colors of HTD in the Qingzhou production area and measured their physicochemical quality. At the same time, a comparative analysis was conducted on the bacterial composition of Qingzhou and Xiangyang regions. The results revealed that the HTD in the Qingzhou area exhibited a diverse bacterial community dominated by Lentibacillus, Scopulibacillus, and Staphylococcus. The black HTD displayed the lowest bacterial richness (P < 0.05) and a relatively unique microbial structure. Significant variations were observed in the physicochemical qualities of the three colors of HTD. Notably, white HTD demonstrated higher moisture and ash content, saccharification and liquor-producing power. Yellow HTD exhibited higher amino nitrogen and protein content, and black HTD displayed higher water activity, acidity, and starch content. The variation in Bacillus, Limosilactobacillus, and Weissella distributions across different colors of HTD primarily contributed to these findings. From the HTD samples in the Qingzhou area, Bacillus (61.90 %) and lactic acid bacteria (17.46 %) being the predominant cultivable communities. Cluster analysis identified significant differences in bacterial communities among HTD samples from various production areas. It can enhance the understanding of HTD quality in the Qingzhou area and offer insights for optimizing HTD and Maotai-flavor Baijiu quality.

Comparative analysis of sensory features, microbial diversity, and their correlations in light-flavor Daqu from different regions.

This study performed a comparative analysis of the sensory and microbial profiles of light-flavor Bijou (LFD) from Taiyuan (Shanxi Province) and Suizhou (Hubei Province) in China. The results of the electronic nose showed that the aromatic substances of the LFD from Taiyuan (TLFD) were significantly higher (p < .05), while alcohol and aldehyde substances were significantly lower (p < .05) compared with the LFD from Suizhou (SLFD). The average response values of sensors W1C (sensitive to aromatic hydrocarbons), W3C (sensitive to amine and aromatic components), W5C (sensitive to olefins, aromatics, and polar molecules), and W2S (sensitive to alcohol and aldehyde compounds) to TLFD were 0.26, 0.33, 0.34, and 7.72, whereas the response values to SLFD were 0.25, 0.32, 0.33, and 8.04, respectively. The electronic tongue results showed that the aftertaste A (bitter aftertaste) and aftertaste B (astringent aftertaste) of the TLFD were significantly higher (p < .05) and umami was significantly lower (p < .05) as compared to the SLFD. The relative intensities of the aftertaste A, aftertaste B, and umami indicators of TLFD were 0.10, -0.008, and -0.22, respectively, while those of SLFD were -0.23, -0.36, and 0.835, respectively. MiSeq high-throughput sequencing results showed that TLFD exhibited lower fungal richness and diversity compared to SLFD. The dominant bacterial genera were mainly Bacillus (58.12%), Kroppenstedtia (10.11%), and Weissella (6.26%), and the dominant fungal genera were Saccharomycopsis (67.53%), Rasamsonia (9.90%), and Thermoascus (7.10%). Streptomyces and Staphylococcus were identified as the key characteristic microorganisms in TLFD, while Kroppenstedtia, Rasamsonia, and Thermoascus were the key characteristic microorganisms in SLFD. Correlation analysis indicated a stronger correlation between microorganisms and sensory characteristics in SLFD samples. This study provides valuable insights into the sensory and microbiological characteristics of LFD from different regions and offers a new perspective for understanding the production of differently flavored light-flavor Baijiu.

Switchable chemoselective aryne reactions between nucleophiles and pericyclic reaction partners using either 3-methoxybenzyne or 3-silylbenzyne.

Arynes are known to serve as highly reactive benzene-based synthons, which have gained numerous successes in preparing functionalized arenes. Due to the superb electrophilic nature of these fleeting species, however, it is challenging to modulate the designated aryne transformation chemoselectively, when substrates possess multiple competing reaction sites. Here, we showcase our effort to manipulate chemoselective control between two major types of aryne transformations using either 3-methoxybenzyne or 3-silylbenzyne, where nucleophilic addition-triggered reactions and non-polar pericyclic reactions could be differentiated. This orthogonal chemoselective protocol is found to be applicable between various nucleophiles, i.e., imidazole, N-tosylated/N-alkyl aniline, phenol, and alcohol, and an array of pericyclic reaction partners, i.e., furan, cyclopentadiene, pyrrole, cycloheptatrienone, and cyclohexene. Beyond arylation reactions, C-N bond insertion, Truce-Smiles rearrangement, and nucleophilic annulation are appropriate reaction modes as well. Moreover, this chemoselective protocol can find potential synthetic application.

Moisture content online detection system based on multi-sensor fusion and convolutional neural network.

To monitor the moisture content of agricultural products in the drying process in real time, this study applied a model combining multi-sensor fusion and convolutional neural network (CNN) to moisture content online detection. This study built a multi-sensor data acquisition platform and established a CNN prediction model with the raw monitoring data of load sensor, air velocity sensor, temperature sensor, and the tray position as input and the weight of the material as output. The model's predictive performance was compared with that of the linear partial least squares regression (PLSR) and nonlinear support vector machine (SVM) models. A moisture content online detection system was established based on this model. Results of the model performance comparison showed that the CNN prediction model had the optimal prediction effect, with the determination coefficient (R2) and root mean square error (RMSE) of 0.9989 and 6.9, respectively, which were significantly better than those of the other two models. Results of validation experiments showed that the detection system met the requirements of moisture content online detection in the drying process of agricultural products. The R2 and RMSE were 0.9901 and 1.47, respectively, indicating the good performance of the model combining multi-sensor fusion and CNN in moisture content online detection for agricultural products in the drying process. The moisture content online detection system established in this study is of great significance for researching new drying processes and realizing the intelligent development of drying equipment. It also provides a reference for online detection of other indexes in the drying process of agricultural products.

Quality and Process Optimization of Infrared Combined Hot Air Drying of Yam Slices Based on BP Neural Network and Gray Wolf Algorithm.

In this paper, the effects on drying time (Y1), the color difference (Y2), unit energy consumption (Y3), polysaccharide content (Y4), rehydration ratio (Y5), and allantoin content (Y6) of yam slices were investigated under different drying temperatures (50-70 °C), slice thicknesses (2-10 mm), and radiation distances (80-160 mm). The optimal drying conditions were determined by applying the BP neural network wolf algorithm (GWO) model based on response surface methodology (RMS). All the above indices were significantly affected by drying conditions (p < 0.05). The drying rate and effective water diffusion coefficient of yam slices accelerated with increasing temperature and decreasing slice thickness and radiation distance. The selection of lower temperature and slice thickness helped reduce the energy consumption and color difference. The polysaccharide content increased and then decreased with drying temperature, slice thickness, and radiation distance, and it was highest at 60 °C, 6 mm, and 120 mm. At 60 °C, lower slice thickness and radiation distance favored the retention of allantoin content. Under the given constraints (minimization of drying time, unit energy consumption, color difference, and maximization of rehydration ratio, polysaccharide content, and allantoin content), BP-GWO was found to have higher coefficients of determination (R2 = 0.9919 to 0.9983) and lower RMSEs (reduced by 61.34% to 80.03%) than RMS. Multi-objective optimization of BP-GWO was carried out to obtain the optimal drying conditions, as follows: temperature 63.57 °C, slice thickness 4.27 mm, radiation distance 91.39 mm, corresponding to the optimal indices, as follows: Y1 = 133.71 min, Y2 = 7.26, Y3 = 8.54 kJ·h·kg-1, Y4 = 20.73 mg/g, Y5 = 2.84 kg/kg, and Y6 = 3.69 µg/g. In the experimental verification of the prediction results, the relative error between the actual and predicted values was less than 5%, proving the model's reliability for other materials in the drying technology process research to provide a reference.

Exploring jujube wine flavor and fermentation mechanisms by HS-SPME-GC-MS and UHPLC-MS metabolomics.

The fermentation metabolites significantly influence the quality of jujube wine. However, the dynamics of these metabolites during fermentation are not well understood. In this study, a total of 107 volatile and 1758 non-volatile compounds were identified using a flavor-directed research strategy and non-targeted metabolomics. The increase in esters and alcohols during fermentation shifted the aroma from grassy, mushroomy, and earthy to a floral and fruity flavor in the jujube wine. Leucine and phenylalanine were notably enriched during fermentation, potentially benefiting human health and enriching the flavor of fruit wines. Moreover, pathway analysis identified four key metabolic pathways and two crucial metabolic substrates, pyruvate and l-aspartate. This study provides a theoretical reference for optimizing the fermentation process and enhancing the quality of jujube wine.

Ultra-high-depth macrogenomic sequencing revealed differences in microbial composition and function between high temperature and medium-high temperature Daqu.

Complex microorganisms in Daqu of different temperatures play a vital role in the taste, flavor and quality of Baijiu during fermentation. However, understanding the functional diversity of the whole microbial community between the Daqus of two different temperatures (high temperature Daqu, HD and medium-high temperature Daqu, MD) remains a major challenge. Here, a systematic study of the microbial diversity, functions as well as physiological and biochemical indexes of Daqu are described. The results revealed that the Daqu exhibited unique characteristics. In particular, the diversity of microorganisms in HD and MD was high, with 44 species including 14 novel species (Sphingomonas sp. is the main novel species) detected in all samples. Their profiles of carbohydrate-active enzymes and specific functional components supported the fact that these species were involved in flavor formation. The Daqu microbiome consisted of a high proportion of phage, providing evidence of phage infection/genome integration and horizontal gene transfer from phage to bacteria. Such processes would also regulate Daqu microbiomes and thus flavor quality. These results enrich current knowledge of Daqu and can be used to promote the development of Baijiu fermentation technology.

[Research progress in vaccines of SARS-CoV-2].

Since the outbreak of corona virus disease 2019 (COVID-19), viral strains have mutated and evolved. Vaccine research is the most direct and effective way to control COVID-19. According to different production mechanisms, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines included inactivated virus vaccine, live attenuated vaccine, mRNA vaccine, DNA vaccine, viral vector vaccine, virus-like particle vaccine and protein subunit vaccine. Among them, viral protein subunit vaccine has a wide application prospect due to its high safety and effectiveness. Viral nucleocapsid protein has high immunogenicity and low variability which could be a new direction for vaccine production. We summarized the current development of vaccine research by reviewing the current progress, vaccine safety and vaccine immune efficiency. It is hoped that the proposed possible development strategies could provide a reference for epidemic prevention work in future.

Exploring metabolic dynamics during the fermentation of sea buckthorn beverage: comparative analysis of volatile aroma compounds and non-volatile metabolites using GC-MS and UHPLC-MS.

Sea buckthorn has a high nutritional value, but its sour taste and foul odor make it unpalatable for consumers. In this study, we analyzed the metabolite changes occurring during the yeast-assisted fermentation of sea buckthorn juice using the HeadSpace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) and Ultra-High Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS) techniques. A total of 86 volatile aroma compounds were identified during the fermentation process. The content of total volatiles in sea buckthorn juice increased by 3469.16 µg/L after 18 h of fermentation, with 22 compounds showing elevated levels. Notably, the total content of esters with fruity, floral, and sweet aromas increased by 1957.09 µg/L. We identified 379 non-volatile metabolites and observed significant increases in the relative abundance of key active ingredients during fermentation: glycerophosphorylcholine (increased by 1.54), glutathione (increased by 1.49), L-glutamic acid (increased by 2.46), and vanillin (increased by 0.19). KEGG pathway analysis revealed that amino acid metabolism and lipid metabolism were the primary metabolic pathways involved during fermentation by Saccharomyces cerevisiae. Fermentation has been shown to improve the flavor of sea buckthorn juice and increase the relative content of bioactive compounds. This study provides novel insights into the metabolic dynamics of sea buckthorn juice following yeast fermentation through metabolomics analysis. These findings could serve as a theoretical foundation for further studies on the factors influencing differences in yeast fermentation.

Drying Temperature Precision Control System Based on Improved Neural Network PID Controller and Variable-Temperature Drying Experiment of Cantaloupe Slices.

A drying temperature precision control system was studied to provide technical support for developing and further proving the superiority of the variable-temperature drying process. In this study, an improved neural network (INN) proportional-integral-derivative (PID) controller (INN-PID) was designed. The dynamic performance of the PID, neural network PID (NN-PID) and INN-PID controllers was simulated with unit step signals as an input in MATLAB software. A drying temperature precision control system was set up in an air impingement dryer, and the drying temperature control experiment was carried out to verify the performance of the three controllers. Linear variable-temperature (LVT) and constant-temperature drying experiments of cantaloupe slices were carried out based on the system. Moreover, the experimental results were evaluated comprehensively with the brightness (L value), colour difference (ΔE), vitamin C content, chewiness, drying time and energy consumption (EC) as evaluation indexes. The simulation results show that the INN-PID controller outperforms the other two controllers in terms of control accuracy and regulation time. In the drying temperature control experiment at 50 °C-55 °C, the peak time of the INN-PID controller is 237.37 s, the regulation time is 134.91 s and the maximum overshoot is 4.74%. The INN-PID controller can quickly and effectively regulate the temperature of the inner chamber of the air impingement dryer. Compared with constant-temperature drying, LVT is a more effective drying mode as it ensures the quality of the material and reduces the drying time and EC. The drying temperature precision control system based on the INN-PID controller meets the temperature control requirements of the variable-temperature drying process. This system provides practical and effective technical support for the variable-temperature drying process and lays the foundation for further research. The LVT drying experiments of cantaloupe slices also show that variable-temperature drying is a better process than constant-temperature drying and is worthy of further study to be applied in production.

Comparative genomic analysis of the genus Weissella and taxonomic study of Weissella fangxianensis sp. nov., isolated from Chinese rice wine starter.

In this study, three lactic acid bacteria, namely, HBUAS51963T, HBUAS51964 and HBUAS51965, were isolated from Chinese rice wine starter sampled in Fangxian County, PR China. All were non-motile, non-spore-forming and Gram-positive spherical cells. Their taxonomic status was characterized using a polyphasic approach. Genome-based analysis revealed that all three strains were phylogenomically related to Weissella thailandensis KCTC 3751T and Weissella paramesenteroides ATCC 33313T. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the three strains and the phylogenetically related type strains were less than 54.8 and 93.8 %, respectively, and thus, they were below the thresholds of dDDH and ANI for species definition. The genomic DNA G+C content was 38.6 mol %. The predominant fatty acid methyl esters (>10 %) were C16 : 0, C19 : 0 cyc11 and summed feature 10 (C18 : 1 cyc11 and/or ECL 17.834). The polar lipids in the cells of strain HBUAS51963T were mainly phosphatidylglycerol, diphosphatidylglycerol, unidentified glycolipids, phospholipids and lipids. Finally, the three strains were capable of producing d-lactic acid (4.29 g l-1) and various organic acids such as tartaric, acetic, lactic and succinic acids. Overall, the results of genotypic, phenotypic and genomic analyses suggest that the three strains represent a new species of the genus Weissella, for which the name Weissella fangxianis sp. nov. is proposed. The type strain is HBUAS51963T (=GDMCC 1.3506T= JCM 35803T).

Evaluating the effect of lactic acid bacteria fermentation on quality, aroma, and metabolites of chickpea milk.

Legumes are an attractive choice for developing new products since their health benefits. Fermentation can effectively improve the quality of soymilk. This study evaluated the impact of Lactobacillus plantarum fermentation on the physicochemical parameters, vitamins, organic acids, aroma substances, and metabolites of chickpea milk. The lactic acid bacteria (LAB) fermentation improved the color, antioxidant properties, total phenolic content, total flavonoid content, lactic acid content, and vitamin B6 content of raw juice. In total, 77 aroma substances were identified in chickpea milk by headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME-GC-MS); 43 of the 77 aroma substances increased after the LAB fermentation with a significant decrease in beany flavor content (p < 0.05), improving the flavor of the soymilk product. Also, a total of 218 metabolites were determined in chickpea milk using non-targeted metabolomics techniques, including 51 differentially metabolites (28 up-regulated and 23 down-regulated; p < 0.05). These metabolites participated in multiple metabolic pathways during the LAB fermentation, ultimately improving the functional and antioxidant properties of fermented soymilk. Overall, LAB fermentation can improve the flavor, nutritional, and functional value of chickpea milk accelerating its consumer acceptance and development as an animal milk alternative.

Aryne 1,4-Disubstitution and Remote Diastereoselective 1,2,4-Trisubstitution via a Nucleophilic Annulation-[5,5]-Sigmatropic Rearrangement Process.

Both aryne 1,4-disubstitution and 1,2,4-trifunctionalization were accomplished from tertiary amines bearing a penta-2,4-dien-1-yl moiety. These transformations could directly incorporate a C-N and a C-C bond para to each other on an aryne intermediate via a sequential nucleophilic addition and [5,5]-sigmatropic rearrangement. When arynes bearing 3-tethered electrophiles were employed, a cascade regioselective nucleophilic addition, intramolecular cyclization, and remote diastereoselective [5,5]-sigmatropic rearrangement process was observed. Our density functional theory (DFT) calculations revealed that hydrogen-bonding interactions between two C-H hydrogens on the penta-2,4-dien-1-yl chain and the oxygen anion generated upon N-nucleophilic annulation reaction in the [5,5]-sigmatropic rearrangement step is responsible for the remote diastereoselective control in this reaction system.

Depth-depended quality comparison of light-flavor fermented grains from two fermentation rounds.

To improve the utilization of raw materials, the fermentation of light-flavor Baijiu (LFB) will usually take two rounds of fermentation to the same batch of raw materials. The microorganisms involved in the fermented grains (FG) from these two fermentation rounds are the key to the quality formation of light-flavor style. Using Illumina MiSeq high-throughput sequencing and electronic-senses, it was found that the microbiota and flavor of FG for light-flavor Baijiu were mainly affected by fermentation rounds rather than depths, while the physicochemical factors were just the opposite. Starch was the most influential physiochemical factor on the microbiota. FG from the first fermentation round (FFRFG) had a higher fungal diversity, while FG from the second fermentation round (SFRFG) had a higher microbial richness and bacterial diversity. Monascus and the function of metabolism were significantly enriched in FFRFG; while Nocardia, Saccharomyces, Aspergillus and the functions of information storage and processing as well as cellular processes and signaling were significantly enriched in SFRFG. The flavor characteristics of FFRFG were mainly sourness as well as rich in sulfur organic compounds and broad range compounds, while that of SFRFG was mainly saltiness, umami, and bitterness, as well as rich in aromatic compounds. The findings could contribute to a comprehensive understanding of the role of FG in LFB fermentation from the perspective of rounds and depths.

Insights into the Aroma Profile of Sauce-Flavor Baijiu by GC-IMS Combined with Multivariate Statistical Analysis.

Aroma is among the principal quality indicators for evaluating Baijiu. The aroma profiles of sauce-flavor Baijiu produced by 10 different manufacturers were determined by GC-IMS. The results showed that GC-IMS could effectively separate the volatile compounds in Baijiu, and a total of 80 consensus volatile compounds were rapidly detected from all samples, among which 29 volatile compounds were identified, including 5 alcohols, 14 esters, 2 acids, 2 ketones, 5 aldehydes, and 1 furan. According to the differences in aroma profile found by multivariate statistical analysis, these sauce-flavor Baijiu produced by 10 different manufacturers can be further divided into three types. The relative odor activity value of the identified volatile compounds indicated that seven volatile compounds contributed most to the aroma of sauce-flavor Baijiu in order of aroma contribution rate, and they were ethyl hexanoate, ethyl pentanoate, ethyl 2-methylbutanoate, ethyl octanoate (also known as octanoic acid ethyl ester), ethyl 3-methylbutanoate, ethyl butanoate, and ethyl isobutyrate. Correspondingly, the main aromas of these sauce-flavor Baijiu produced by 10 different manufacturers were sweet, fruity, alcoholic, etheral, cognac, rummy, and winey. On the one hand, this study proved that GC-IMS is well adapted to the detection of characteristic volatile aroma compounds and trace compounds in Baijiu, which is of positive significance for improving the aroma fingerprint and database of sauce-flavor Baijiu. On the other hand, it also enriched our knowledge of Baijiu and provided references for the evaluation and regulation of the flavor quality of sauce-flavor Baijiu.

Effects of five extraction methods on total content, composition, and stability of flavonoids in jujube.

The present study investigated the effects of different extraction methods including water-water bath (W-WB), ethanol-water bath (E-WB), deep eutectic solvent (DES) combined with ultrasound-assisted extraction (DES-UAE), microwave-assisted extraction (DES-MAE), and enzyme-assisted extraction (DES-EAE) on flavonoids (total flavonoid content, flavonoid composition, and stability) in jujube. The highest total flavonoid content of 8.03 mg/g was obtained by the DES-MAE extraction. Fifteen types of flavonoids were identified from jujube. The amount of rutin produced by the E-WB and DES-UAE methods was 66.88 ± 1.58 µg/g and 45.23 ± 3.22 µg/g, respectively. The retention of flavonoids in DES-UAE extracts were 98.15 ± 0.51%, 64.25 ± 2.21% after 2 h of high temperature treatment at 90 °C and 21 days of dark storage, respectively. The flavonoids extracted by different methods were suitable for dark storage under different light contrasts, where the retention of flavonoids extracted by DES-UAE method was 86.44 ± 2.45%. In conclusion, DES-UAE would be an efficient method for flavonoid extraction from jujube.

Low-temperature adaptation and preservation revealed by changes in physiological-biochemical characteristics and proteome expression patterns in post-harvest Hami melon during cold storage.

MAIN CONCLUSION: The proteome and its time-dependent effects reveal the importance of stress response (including expression regulation of heat-shock proteins) and fatty acid metabolism in cold adaptation and preservation of Hami melon. To better understand the molecular mechanism of how Hami melons respond to low-temperature stress, this study investigated the relevant physiological characteristics, catalytic antibody activity, and quantitative proteomics of Hami melon (Jiashi muskmelon) during low-temperature storage. Jiashi muskmelon was stored inside two refrigerators set at 21 °C (control group) and 3 °C, respectively, for 24 days. Low-temperature storage led to a significantly reduced decay rate, weight loss rate, and loss of relative conductivity. It also maintained fruit firmness, inhibited the production rate of malondialdehyde and H2O2, and induced over-expression of antioxidant enzyme and ATPase. A total of 1064 differentially expressed proteins (DEPs) were identified during low-temperature storage. Stimulation response was the main process in response to low-temperature. To further verify the proteome data, we selected four heat-shock proteins (HSP) displaying relatively high expression levels. Real-time fluorescence PCR results confirmed that HmHSP90 I, HmHSP90 II, HmHSP70, and HmsHSP were significantly up-regulated upon low-temperature induction. These proteins may protect the Hami melon from physiological and cellular damage due to the low-temperature stress by acting alone or synergistically. Additionally, the main enrichment term of the fatty acid metabolism-related DEPs was fatty acid beta oxidation at 21 °C in contrast to fatty acid biosynthesis processes at 3 °C. It is speculated that Hami melon enhances low-temperature adaptability by slowing down the oxidative degradation of fatty acids and synthesizing new fatty acids at low temperatures. This study provides new insights into the mechanism of low-temperature adaptation and preservation in post-harvest Hami melon during cold storage.

The Stannum-Ene Reactions of Benzyne and Cyclohexyne with Superb Chemoselectivity for Cyclohexyne.

The stannum-ene reactions of both benzyne and cyclohexyne were realized, which is particularly suitable for cyclohexyne with a broad substrate scope and excellent chemoselectivity. Our DFT calculations via distortion/interaction analysis revealed that both stannum- and hydrogen-ene reactions with cyclohexyne have later transition states due to their higher distortion energies in the transition states than those in benzyne reactions, which lead to enhanced Pauli repulsion as the decisive factor in the interaction energy accompanied with enlarged energy gap between two types of ene reactions. Therefore, excellent chemoselectivity was disclosed in the cyclohexyne-ene reaction.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May-Thurner syndrome.

PURPOSE: To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May-Thurner syndrome. METHODS: Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen. RESULTS: There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05). CONCLUSIONS: Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May-Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.