A time-space network-based model for transportation service optimization of China Railway Express

This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.

Genome-Wide Discovery and Expression Profiling of the SWEET Sugar Transporter Gene Family in Woodland Strawberry (Fragaria vesca) under Developmental and Stress Conditions: Structural and Evolutionary Analysis

The SWEET(sugar will eventually be exported transporter)family proteins are a recently identified class of sugar transporters that are essential for various physiological processes.Although the functions of the SWEET proteins have been identified in a number of species,to date,there have been no reports of the functions of the SWEET genes in woodland strawberries(Fragaria vesca).In this study,we identified 15 genes that were highly homolo-gous to the A.thaliana AtSWEET genes and designated them as FvSWEET1–FvSWEET15.We then conducted a structural and evolutionary analysis of these 15 FvSWEET genes.The phylogenetic analysis enabled us to categor-ize the predicted 15 SWEET proteins into four distinct groups.We observed slight variations in the exon‒intron structures of these genes,while the motifs and domain structures remained highly conserved.Additionally,the developmental and biological stress expression profiles of the 15 FvSWEET genes were extracted and analyzed.Finally,WGCNA coexpression network analysis was run to search for possible interacting genes of FvSWEET genes.The results showed that the FvSWEET10 genes interacted with 20 other genes,playing roles in response to bacterial and fungal infections.The outcomes of this study provide insights into the further study of FvSWEET genes and may also aid in the functional characterization of the FvSWEET genes in woodland strawberries.

Identification and expression analysis of sugar transporter family genes reveal the role of ZmSTP2 and ZmSTP20 in maize disease resistance

Sugar is an indispensable source of energy for plant growth and development, and it requires the participation of sugar transporter proteins(STPs) for crossing the hydrophobic barrier in plants. Here, we systematically identified the genes encoding sugar transporters in the genome of maize(Zea mays L.), analyzed their expression patterns under different conditions, and determined their functions in disease resistance. The results showed that the mazie sugar transporter family contained 24 members, all of which were predicted to be distributed on the cell membrane and had a highly conserved transmembrane transport domain. The tissue-specific expression of the maize sugar transporter genes was analyzed, and the expression level of these genes was found to be significantly different in different tissues. The analysis of biotic and abiotic stress data showed that the expression levels of the sugar transporter genes changed significantly under different stress factors. The expression levels of Zm STP2 and Zm STP20 continued to increase following Fusarium graminearum infection. By performing disease resistance analysis of zmstp2 and zmstp20 mutants, we found that after inoculation with Cochliobolus carbonum, Setosphaeria turcica, Cochliobolus heterostrophus, and F. graminearum, the lesion area of the mutants was significantly higher than that of the wild-type B73 plant. In this study, the genes encoding sugar transporters in maize were systematically identified and analyzed at the whole genome level. The expression patterns of the sugar transporter-encoding genes in different tissues of maize and under biotic and abiotic stresses were revealed, which laid an important theoretical foundation for further elucidation of their functions.

The heterogeneous impact of China-Europe railway express on the efficiency of logistics industry in node cities

Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low-added-value marine products,significantly impacting the logistics industry efficiency.However,there are few literature verifying and analyzing its heterogeneity.This study explores the impact of CR-Express on the efficiency of logistics industry in node cities and analyzes the heterogeneity.Design/methodology/approach-First,this study uses panel data to measure the efficiency of node city logistics industry.Secondiy,this study discusses the impact of the opening of CR-Express on the efficiency of logistics industry in node cities based on the multi-period differential model.Finally,according to the node city difference,the sample city experimental group is grouped for heterogeneity analysis.Findings-The results show that CR-Express can promote the urban logistics industry efficiency,with an average effect of 4.55%.According to the urban characteristics classification,the heterogeneity analysis shows that the efficiency improvement effect of logistics industry in inland cities is more obvious.The improvement effect of node cities and central cities in central and western China is stronger,especially in the sample of megacities and type I big cities.Compared with non-value chain industrial products,the CR-Express has significant promotion effects on the logistics efficiency of the cities where main goods are value chain products.Originality/value-Under the background of double cycle development,this paper can provide a scientific basis for the investment benefit evaluation of CR-Express construction and the follow-up route planning.

Transcriptome-based identification and expression analysis of the glutathione S-transferase(GST)family in tree peony reveals a likely role in anthocyanin transport

For red-flowered cultivars of tree peony(Paeonia suffruticosa),anthocyanin content is a critical factor determining the different petal pigmentations.Glutathione S-transferases(GSTs)are ubiquitous and multifunctional conjugating proteins that may be responsible for the transport of anthocyanin pigments from the cytoplasm to vacuole.The underlying function of the GST family in tree peony,however,remains unclear.In this study,we systematically isolated and identified a total of 54 putative full-length Ps GST genes through a combination of bioinformatics approaches from transcriptome databases.Intraspecific phylogenetic analyses revealed extensive differentiation in their coding sequences and divided them into 10 of the 14 known classes of plant GSTs.The phylogenetic relationships,evolutionary characteristics,protein domain,and motif organization were clearly conserved among the different phylogenetic subclasses.The results of the RNA-seq and quantitative real-time polymerase chain reaction experiments exhibited extensive variation in gene expression profiles among different developmental stages and varieties.Furthermore,the phylogenetic relationships,expression profiles,protein interactions,weighted gene co-expression network analysis,and correlation analysis results suggested that PsGSTF3(Unigene 0064200)is a candidate participant in anthocyanin transport and the promotion of pigment accumulation,exhibiting a strong positive correlation with anthocyanin content among different tissues(r=0.908**)and an increasing rate of anthocyanin content during the flower developmental process(r=0.961*).These results furthered our understanding of the transport and accumulation functions of the GST family as well as the enhancement of tree peony breeding through molecular biology techniques.

Expression Pattern of Peptide and Amino Acid Genes in Digestive Tract of Transporter Juvenile Turbot(Scophthalmus maximus L.)

Turbot(Scophthalmus maximus L.),a carnivorous fish species with high dietary protein requirement,was chosen to examine the expression pattern of peptide and amino acid transporter genes along its digestive tract which was divided into six segments including stomach,pyloric caeca,rectum,and three equal parts of the remainder of the intestine.The results showed that the expression of two peptide and eleven amino acid transporters genes exhibited distinct patterns.Peptide transporter 1(Pep T1) was rich in proximal intestine while peptide transporter 2(PepT2) was abundant in distal intestine.A number of neutral and cationic amino acid transporters expressed richly in whole intestine including B^0-type amino acid transporter 1(B^0AT1),L-type amino acid transporter 2(LAT2),T-type amino acid transporter 1(TAT1),proton-coupled amino acid transporter 1(PAT1),y^+L-type amino acid transporter 1(y^+LAT1),and cationic amino acid transporter 2(CAT2) while ASC amino acid transporter 2(ASCT2),sodium-coupled neutral amino acid transporter 2(SNAT2),and y^+L-type amino acid transporter 2(y^+LAT2) abundantly expressed in stomach.In addition,system b^(0,+) transporters(rBAT and b^(0,+)AT) existed richly in distal intestine.These findings comprehensively characterized the distribution of solute carrier family proteins,which revealed the relative importance of peptide and amino acid absorption through luminal membrane.Our findings are helpful to understand the mechanism of the utilization of dietary protein in fish with a short digestive tract.

TfR1 Extensively Regulates the Expression of Genes Associated with Ion Transport and Immunity

Transferrin receptor 1(TfR1),encoded by the TFRC gene,is the gatekeeper of cellular iron uptake for cells.A variety of molecular mechanisms are at work to tightly regulate TfR1 expression,and abnormal TfR1 expression has been associated with various diseases.In the current study,to determine the regulation pattern of TfR1,we cloned and overexpressed the human TFRC gene in HeLa cells.RNA-sequencing(RNA-seq)was used to analyze the global transcript levels in overexpressed(OE)and normal control(NC)samples.A total of 1669 differentially expressed genes(DEGs)were identified between OE and NC.Gene ontology(GO)analysis was carried out to explore the functions of the DEGs.It was found that multiple DEGs were associated with ion transport and immunity.Moreover,the regulatory network was constructed on basis of DEGs associated with ion transport and immunity,highlighting that TFRC was the node gene of the network.These results together suggested that precisely controlled TfR1 expression might be not only essential for iron homeostasis,but also globally important for cell physiology,including ion transport and immunity.

Elevated NKCC1 transporter expression facilitates early post-traumatic brain injury seizures

As a leading cause for morbidity and mortality in young adults,traumatic brain injury（TBI）,along with the poorly understood TBI-related seizures inducing their predispositions,pose a major health and socioeconomic problem in the world（Huang,2013）.

Effect of Bacillus subtilis,Enterococcus faecium,and Enterococcus faecalis supernatants on serotonin transporter expression in cells and tissues

BACKGROUND Bacillus subtilis(B.subtilis),Enterococcus faecium(E.faecium),and Enterococcus faecalis(E.faecalis)are probiotics that are widely used in the clinical treatment of irritable bowel syndrome(IBS).Whether the supernatants of these three probiotics can improve gastrointestinal sensation and movement by regulating the serotonin transporter(SERT)expression needs to be clarified.AIM To investigate whether B.subtilis,E.faecium,and E.faecalis supernatants can upregulate SERT expression in vitro and in vivo.METHODS Caco-2 and HT-29 cells were stimulated with probiotic culture supernatants for 12 and 24 h,respectively.A male Sprague-Dawley rat model of post-infectious irritable bowel syndrome(PI-IBS)was established and the rats were treated with phosphate-buffered saline(group A)and three probiotics culture supernatants(groups B,C,and D)for 4 wk.The levels of SERT were detected by quantitative PCR and western blotting.RESULTS The levels of SERT at post-treatment 12 and 24 h were significantly elevated in Caco-2 cells treated with B.subtilis supernatant compared with those in the control group(aP<0.05).Those levels were markedly upregulated in Caco-2 cells stimulated with E.faecium and E.faecalis supernatants at 24 h(aP<0.05).In addition,SERT expression in groups B,C,and D was significantly higher than that in group A in the 2nd wk(aP<0.05).Increased SERT expression was only found in group D in the 3rd wk(aP<0.05).However,there was no significant difference in SERT expression between the groups in the last week(P>0.05).CONCLUSION The supernatants of B.subtilis,E.faecium,and E.faecalis can upregulate SERT expression in intestinal epithelial cells and the intestinal tissues in the rat model of PI-IBS.

Differential expression of cholangiocyte and ileal bile acid transporters following bile acid supplementation and depletion

AIM: We have previously demonstrated that cholangiocytes, the epithelial cells lining intrahepatic bile ducts,encode two functional bile acid transporters via alternative splicing of a single gene to facilitate bile acid vectorial transport. Cholangiocytes possess ASBT,an apical sodium-dependent bile acid transporter to take up bile acids,and t-ASBT,a basolateral alternatively spliced and truncated form of ASBT to efflux bile acids.Though hepatocyte and ileal bile acid transporters are in part regulated by the flux of bile acids, the effect of alterations in bile acid flux on the expression of t-ASBT in terminal ileocytes remains undear.Thus,we tested the hypothesis that expression of ASBT and t-ASBT in cholangiocytes and ileocytes was regulated by bile acid flux. METHODS: Expression of ASBT and t-ASBT message and protein in cholangiocytes and ileocytes isolated from pair- fed rats given control (C) and 1% taurocholate (TCA) or 5% cholestyramine (CY) enriched diets,were assessed by both quantitative RNase protection assays and quantitative immunoblotting.The data obtained from each of the control groups were pooled to reflect the changes observed following TCA and CY treatments with respect to the control diets. Cholangiocyte taurocholate uptake was determined using a novel microperfusion technique on intrahepatic bile duct units (IBDUs) derived from C,TCA and CY fed rats. RESULTS: In cholangiocytes,both ASBT and t-ASBT message RNA and protein were significantly decreased in response to TCA feeding compared to C diet.In contrast, message and protein of both bile acid transporters significantly increased following CY feeding compared to C diet.In the ileum,TCA feeding significantly up-regulated both ASBT and t-ASBT message and protein compared to C diet,while CY feeding significantly down-regulated message and protein of both bile acid transporters compared to C diet.As anticipated from alterations in cholangiocyte ASBT expression,the uptake of taurocholate in microperfused IBDUs derived from rats on TCA diet decreased 2.7-fold,whereas it increased 1.7-fold in those on CY diet compared to C diet fed groups. CONCLUSION: These data demonstrate that expression of ASBT and t-ASBT in cholangiocytes is regulated by a negative feedback loop while the expression of these transporters in terminal ileum is modified via positive feedback.Thus, while transcriptional regulatory mechanisms in response to alterations in bile acid pool size are operative in both cholangiocytes and ileocytes,each cell type responds differently to bile acid supplementation and depletion.

Effect of Xylanase on mRNA Expression of Cationic Amino Acid Transporters in Intestines of Broilers

480 healthy 1-day-old male yellow-feathered chickens were selected and assigned randomly into groups A and B,each having 6 pens with 40 birds per pen.The birds in group A were fed with wheatbased diet and group B with wheat-based diet supplemented with xylanase(1.2×l0~4 U/kg diet).On day 16,two birds per replication with average live weight were selected and sacrificed.Tissue samples of jejunum and ileum were collected to detect mRNA expression of cationic amino acid transporters using RT-PCR.The results showed that xylanase significantly increased the abundance of mRNA for rBAT and CAT4 in the intestines of broilers fed with wheat-based diets(P<0.05)and had a tendency to increase the mRNA expression of y^+LAT2 and CAT1 in jejunum(P>0.05),y^+LAT2,CAT1 and CAT4 in ileum(P>0.05).The treatment had no effect on the expression of rBAT mRNA in ileum(P>0.05).

Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows

Background： Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian （HF）, Jersey （JE） and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80℃. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gen, expression values and production efficiency variables. Results： While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect （P 〈 0.05） on ABCGS, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 （P= 0.072）, SLC3A2 （P= 0.081） and SLC6A 14 （P= 0.072） was also evident in the F1 genotype. A negative （P 〈 0.05） association was identified between the expression of the glucose transporter gene SLCSA1 and total lactational milk solids yield, corrected for body weight. Positive correlations （P 〈 0.05） were also observed between the expression values of genes involved in common transporter roles. Conclusion： This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed efficiency between HF, JE and their F1 hybrid. Furthermore, positive associations between the expression of genes involved in common transporter roles suggest that these may be co-regulated. The study identifies potential candidates for investigation of genetic variants regulating nutrient transport and absorption in the duodenum in dairy cows, which may be incorporated into future breeding programmes.

西瓜蔗糖转运蛋白SUT家族的鉴定及其在果实发育和逆境响应中的表达分析

蔗糖转运蛋白(SUTs)作为蔗糖主动转运的主要载体,在分配同化物从源到库组织的转运中起着关键作用。尽管SUTs的特性及其生物学功能已在高等植物中得到了深入研究,但该基因家族尚未在西瓜中进行鉴定。本研究在西瓜基因组中共鉴定了4个ClSUT基因,并对其基因和蛋白结构、保守基序、亚细胞定位、染色体分布、进化关系、启动子元件等进行了全面分析。基因结构分析表明,亚族Ⅰ的ClSUT3和ClSUT4基因均只含有一个内含子。所有ClSUT均被预测定位在质膜中,它们均含有一个保守的MFS-2结构域,并且含有与之对应的5个保守基序。系统发育分析发现拟南芥、水稻和西瓜中的SUT分为5个亚族,西瓜ClSUT与拟南芥SUT的亲缘关系更近,被聚类在亚族Ⅰ、亚族Ⅱ和亚族Ⅴ。还在西瓜ClSUT基因的启动子中鉴定到一些与激素和逆境响应相关的作用元件。此外,转录组数据表明,西瓜ClSUT基因的表达对渗透和盐胁迫呈现多样性,很可能参与西瓜对这些逆境的响应。

南粳系列超级稻品种灌浆期光合产物的分配特性

【目的】研究南粳系列超级稻灌浆期光合产物转运和分配及相关基因表达量的变化特性及其与对照品种的差异,总结南粳系列超级稻高产的生理优势,为优质高产粳稻的培育提供理论依据。【方法】采用南粳5718、南粳晶谷、南粳3908和南粳5055为研究对象,以淮稻5号为对照,在孕穗期、开花期以及开花后每隔7 d至成熟期测定剑叶光合速率、地上部干物质分配和转运,以及剑叶和籽粒发育不同时期物质转运相关基因的表达量,统计产量差异。【结果】南粳系列超级稻产量和千粒重高于淮稻5号,其剑叶净光合速率在孕穗期和花后28 d显著高于淮稻5号。在物质转运方面,南粳系列超级稻开花后茎叶干重、叶片输出量、输出率和转运率显著高于淮稻5号,其中南粳5718叶片输出量和输出率最高。南粳5718剑叶中与淀粉降解和糖类代谢相关基因(OsSPS1,OsSUT2,OsGWD1)的表达比其他品种启动早,最高表达量也高于其他品种。籽粒中SWEET基因在灌浆早期的蔗糖转运过程中扮演重要角色,中后期OsPK3、OsSUT1、OsSUT2基因在糖类的运输卸载中发挥重要作用,OsAGPL2和OsDPE1基因在中后期淀粉合成中发挥重要作用,南粳5718、南粳晶谷、南粳3908籽粒中与淀粉合成和糖类运输的相关基因在不同时期的表达量显著高于淮稻5号。【结论】南粳系列超级稻较高的产量在物质转运方面主要有以下特征:茎秆和叶片物质积累量多,穗积累量大,叶片和茎秆物质转运率高;叶片中蔗糖代谢和转运相关基因表达量高,有利于蔗糖在源端的合成、装载和转运;籽粒中蔗糖转运和淀粉合成相关基因表达量高,有利于蔗糖在库端的卸载及籽粒中淀粉的合成。

融合COLREGs的水上交通场景认知建模

为实现国际海上避碰规则(COLREGs)场景的语义表达与推理,让船舶具备类人的水上交通场景理解与推理能力,提出一种融合COLREGs的场景认知计算建模方法。基于COLREGs水上交通场景的语义描述,将水上交通场景解析为时间、对象、属性、关系、行为、事件等要素相互作用的综合体,构建水上交通场景的概念模型;采用本体建模实现COLREGs场景概念模型的结构化表达;通过定义语义计算操作函数和触发集搭建COLREGs场景认知计算框架,进而提出一种基于逻辑推理的场景认知计算方法。选取厦门港环境和船舶AIS数据,在场景语义抽取的基础上对COLREGs场景认知模型进行案例验证,结果表明:相对于数据驱动的方法,所提模型能够对场景中的对象属性、船舶行为、事件等进行描述和语义计算,并能更好地支持场景中各类要素相关知识的获取与查询。研究提出的场景认知建模方法对于船舶实现规则约束下的场景自主认知具有可行性和有效性。

交通工程专业设计类课程高质量教材建设刍议

在新工科建设背景下,交通工程专业设计类课程教材建设面临层级目标的设定、教材内容与标准规范的联系、知识表达形式、教材的修编再版等挑战,围绕“层级目标、专业实战、多元资源”课程教材建设目标,创新性提出了对教材内容进行从基础设计能力到创新设计能力的层级模块化编排和设计类教材核心词汇语言表达方式的教材建设思路,以实战为导向探索设计类教材知识多样化表现手法,并针对设计类课程的特点,提出教材“编写—修订—再版”全过程动态监测评估的建设技术路径。

家蚕单羧酸转运蛋白基因家族的鉴定与表达模式分析

单羧酸转运蛋白(Monocarboxylate Transporter, MCT)是细胞膜上重要的跨膜转运蛋白,负责乳酸、丙酮酸等单羧酸类化合物的跨膜运输,参与机体代谢平衡调节。通过生物信息学方法对家蚕MCT家族基因成员进行了鉴定分析,并利用qRT-PCR技术对其表达模式进行了检测。结果显示,家蚕基因组中存在21个MCT家族基因,其编码氨基酸长度为438~791 aa,等电点为5.47~9.69。分析发现家蚕MCT家族基因分布于7条染色体上,其中在第5号、7号、13号和23号染色体上存在串联重复现象。该家族基因均编码含有6个以上的保守基序的蛋白质,其中MCT9蛋白含有12个跨膜结构域,与人类、果蝇、蜜蜂、赤拟谷盗、非洲爪蟾中的同源蛋白相似。聚类分析结果显示,21个成员中有15个与果蝇、蜜蜂、赤拟谷盗等昆虫中的MCT蛋白成员聚在一支,而人类只有4个MCT蛋白序列同昆虫聚在一起,其余10个单独聚为一支。进一步对这些基因在家蚕不同组织中的表达模式进行检测,结果显示,BmMCT5基因在家蚕5龄第3天幼虫的中肠组织特异性高量表达,BmMCT1、BmMCT7、BmMCT9-2、BmMCT14-2、BmMCT18基因在马氏管特异性高量表达,推测它们在家蚕的消化、排泄等基础代谢中发挥重要作用。研究结果为深入探讨家蚕MCT家族基因的生物学功能提供了理论依据和数据支持。

关于打通铁路网运输能力堵点对策探究

国铁企业落实党中央部署要求并加快推进铁路货运市场化改革,采取有效措施尽快打通铁路网运输能力堵点,有效降低物流成本。通过分析路网总体规模、旅客运输供给能力、货物运输保障能力等铁路网运输能力现状,剖析铁路网运输能力堵点及成因。在此基础上,提出加强铁路网运输能力经验借鉴,探析打通铁路网运输能力堵点对策,即:畅通普速干线通道,加强煤运通道能力保障,强化中欧班列通道能力,完善港口铁路通过能力,增强西部陆海新通道线路能力,完善枢纽点线配套能力,强化铁路货运设施设备卸车能力等方面,在助力降低全社会物流成本中发挥“火车头”的重要作用。

模拟快递运输对雌性中华绒螯蟹活力及其蟹肉品质的影响

探究雌性中华绒螯蟹(Eriocheir sinensis)在运输过程中活力、生化特性和滋味品质的变化,并分析三者之间的相关性。通过模拟电商生鲜运输条件,对模拟快递运输24 h、48 h和72 h的中华绒螯蟹活力进行统计和评价,以乳酸、挥发性盐基氮(TVB-N)和pH等分析中华绒螯蟹蟹肉生化特性的变化,同时以游离氨基酸、呈味核苷酸及感官等评价中华绒螯蟹蟹肉滋味品质的变化。结果显示,中华绒螯蟹在24 h的模拟运输下,无死亡且活力强劲,蟹肉乳酸和TVB-N等与0 h组无显著差异,且24 h组蟹肉的苦味氨基酸含量最低,为105.10 mg/100 g,印证了活蟹当日送达的重要性。超过24 h后,中华绒螯蟹的活力显著下降,死亡率上升,其中,模拟运输48 h后死亡率为3.33%,72h后死亡率达40.00%;其蟹肉乳酸、TVB-N及pH显著升高;随着运输时间的延长,蟹肉鲜、甜、苦味游离氨基酸含量均呈先下降后上升的趋势,而在模拟运输72 h后,5′-肌苷酸(IMP)含量显著增加至97.47 mg/100 g,5′-鸟苷酸(GMP)含量骤降至6.49 mg/100 g。感官结果则表明,经过模拟快递运输后,蟹肉的鲜味强度降低。综上所述,随着运输时间的延长,雌性中华绒螯蟹的死亡率显著上升,活力显著下降,生化特性和滋味品质发生显著改变,本研究可为销售运输过程中中华绒螯蟹的品质变化提供参考,并为后续运输条件优化提供理论依据。

四指马鲅热休克蛋白70基因(HSP70)表达分析

四指马鲅(Eleutheronema tetradactylum)为名贵海产鱼类,因其对应激反应强烈,易在运输过程中受损。热休克蛋白70(heat shock protein 70,HSP70)作为一种热休克蛋白(heat shock protein,HSP),是HSP家族中最重要的一员,对细胞蛋白质折叠过程及细胞对压力的适应起着重要作用。比较四指马鲅仔鱼和幼鱼在运输胁迫下的抗氧化能力和应激反应,进行幼鱼鳃组织学观察,探究热休克蛋白HSP70基因的组织表达模式以及在仔鱼和幼鱼中的表达差异,研究验证了运输胁迫下仔鱼和幼鱼阶段四指马鲅的抗氧化能力和HSP70表达呈现显著差异,并探讨了其作为评估抗应激反应及养殖管理效果的生物指标的潜力。