“谢谢”的行为反语功能

本文讨论“谢谢”类施为短句回应抵触性引发行为、实施言语行为对抗的隐性否定新用法,即行为反语。“谢谢”的行为对抗功能,朝着交际非当面、回应对象非可控角度发展。从日常对话向网络虚拟对话演进,其行为对抗强度、负面情绪态度发生强化,形成“我谢谢你”等负面对抗性固化表达。“谢谢”的行为对抗功能填补了不礼貌抵触类行为配对的交际空位,满足了互动平衡中“文明对抗”的交际需要。

谢晶日调畅气机抑酸通腑辨治胃食管反流

谢晶日教授认为胃食管反流病(GERD)是情志不遂、饮食不节、素患胆病、脾胃虚弱,气机升降失调,病位在胃与食管,与肝胆脾胃密切相关。治疗从调畅肝气出发,选方灵活、用药审慎、巧设药对、着重整体;活用左金丸,灵活调整黄连和吴茱萸比例,谢师认为左金丸乃辛开苦降,寒热并用之典范,不单局限于肝火证,适用于一切中焦寒热错杂。临证尤注意顾护胃气,常用舒缓平和之品,木香、草豆蔻等香燥之品尤为慎重;调畅气机为主,抑酸为辅,巧设"四石"组合(海螵蛸、海蛤壳、煅瓦楞子、浙贝母)制酸止痛;兼顾上下,畅通腑气;便秘较轻用焦槟榔替代槟榔,大黄与诸药一起煎煮,便秘较重大黄代茶饮,增强通便功效。饮食调护,重视情志因素,嘱患者改变生活方式,清淡饮食,勿过饱,戒除辛辣油腻,好转后仍要注意饮食情志调护,预防复发。

中国哲学史研究的“谢无量范式”

“选出而叙述之”范式是过去百年中国哲学史研究的主流范式。由于同时缺失“中国效度”与“哲学效度”,该范式学理不合法,是中国哲学合法性危机之根源。与“选出而叙述之”范式完全不可通约,由谢无量《中国哲学史》所确立的“谢无量范式”,一方面,从内容到形式上,完全植根于中国传统学术思想,因而深具“中国效度”;另一方面,持“以中观西”“以中化西”的视角与方法,确立了真实的“哲学效度”。“谢无量范式”兼具双重效度,是学理合法的中国哲学研究范式。化解中国哲学合法性危机之道,在于适应当下时代要求,通过实现中国哲学研究从“选出而叙述之”范式向“谢无量范式”的转换,以学理合法的创造性解释来开辟中国哲学无限美好的未来。

“感谢”与“感激”表达的功能差异

行为动词"感谢"和心理动词"感激"在某些句法环境中可互换且语义差异不易辨察,学界尚未深入探究。本文通过对语料库的穷尽性考察,揭示出二者程度延展性及使因性差异。通过描写"感谢"和"感激"与不同句式的互动选择,揭示出二者表达意愿的强弱差异,并建立了"感谢"与"感激"表达主观性的连续统,归纳出"感谢"表达的功能为外显表行,"感激"表达的功能为内隐表情。

周作人“谢本师”事件初探

由于留学日本期间曾在民报社听章太炎讲学,周作人一直视自己为章门弟子。然而1926年周作人却做出了“谢本师”的举动。周作人与章太炎分歧的焦点是他们对“反赤”的态度,章太炎将中国的“赤党”视为苏俄帝国主义入侵中国的傀儡和先锋,故而坚持“反赤”;周作人则由于个人情感和思想倾向的缘故,同情共产党和社会主义理论,并且透过“反赤”看到了军阀对于言论和思想的压迫,故而坚定地批评“反赤”。这两种截然相反的态度实则受章太炎与周作人各自在20年代提出的不同救国方案的影响。章太炎主张联省自治的法制改革,故而十分警惕希望武力统一中国的广州革命政府及其北伐军;周作人则主张以“正当的民族主义”为核心的思想革命,因此透过“反赤”看到了中国人思想上“嗜杀”的“遗传病”。由于北伐结束、国共内战、日本侵华等时局变动,两人的救国方案都无疾而终,并且不约而同地回到了某种“文化救国”的方针上。这促成了师生二人的和解,也为我们揭示了某些为“革命-启蒙”叙事所遮蔽的历史事实。

Advances and Challenges of Exosome Metabolomics in Body Fluids

Exosomes,ubiquitously present in body fluids,serve as non-invasive biomarkers for disease diagnosis,monitoring,and treatment.As intercellular messengers,exosomes encapsulate a rich array of proteins,nucleic acids,and metabolites,although most studies have primarily focused on proteins and RNA.Recently,exosome metabolomics has demonstrated clinical value and potential advantages in disease detection and pathophysiology,despite significant challenges,particularly in exosome isolation and metabolite detection.This review discusses the significant technical challenges in exosome isolation and metabolite detection,highlighting the advancements in these areas that support the clinical application of exosome metabolomics,and illustrates the potential of exosomal metabolites from various body fluids as biomarkers for early disease diagnosis and treatment.

Metabolic characteristics of Qi-Yin deficiency and heat stagnation in liver meridian patterns of dry eye based on tear metabolomics

Objective To explore the metabolic differences between dry eye patients with Qi-Yin defi-ciency and heat stagnation in liver meridian patterns,and clarify their metabolic characteris-tics.Methods Patients with dry eye who were treated in the Ophthalmology Ward and Outpatient Department of the First Hospital of Hunan University of Chinese Medicine from October 1,2020,to October 30,2021 were enrolled as the research participants in the study.They were assigned to two groups based on traditional Chinese medicine(TCM)syndrome types:heat stagnation in liver meridian pattern group and Qi-Yin deficiency pattern group.Healthy vol-unteers who underwent health check-ups in the Health Management Department were in-cluded as healthy group following the random number table method.The tears of the pa-tients and the healthy volunteer participants were tested by high-performance liquid chro-matography-mass spectrometry(LC-MS).The differential metabolites were screened out by multivariate statistical analysis,and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment was performed on the differential metabolites.Finally,the association analysis of differential proteins and metabolites was conducted to verify and supplement the metabolites.Results A total of 32 dry eye patients were enrolled,including 16 cases with heat stagnation in liver meridian pattern and 16 cases with Qi-Yin deficiency pattern.Fourteen healthy volun-teers were included as healthy group.There were no significant differences in baseline char-acteristics among the three groups(P>0.05).A total of 412 biomarkers were determined in Qi-Yin deficiency pattern group,mainly including lipids,lipid-like molecules,organic acids and their derivatives,organic heterocyclic compounds,and nucleosides and their analogues.For heat stagnation in liver meridian pattern group,112 metabolites were determined,main-ly including organic acids and their derivatives,lipids,and lipid-like molecules.The KEGG enrichment results of pathways and the relative content analysis of differential markers de-monstrate that purine metabolism and caffeine metabolism pathways are common metabol-ic characteristics of all dry eyes.Among them,deoxyinosine monophosphate(dIMP)and 2-(formamido)-N1-(5-phospha-D-ribosyl)acetamidine can serve as their biomarkers.The main characteristics of Qi-Yin deficiency syndrome pattern were the significant enhancement of metabolic pathways such as lysine degradation,ovarian steroidogenesis,cholesterol metabolism,pyrimidine metabolism,and bile secretion(P<0.05).Dry eye associated with the heat stagnation in liver meridian pattern is mainly characterized by inhibition of the valine,leucine,and isoleucine biosynthesis pathways(P<0.05).Conclusion Metabolomics can be used as an effective basis for TCM syndrome classification.Different patterns of dry eye syndrome exhibit typical characteristics in the types and concen-trations of metabolites,which correspond to the syndrome classification in TCM.This study initially confirms the rationality of TCM syndrome classification and provides significant ref-erence for the mechanism of dry eye and drug development.

Human AKR1A1 involves in metabolic activation of carcinogenic aristolochic acidⅠ

OBJECTIVE To investigate whether aldo-keto reductases(AKRs)can act as a nitrore⁃ductase(NR)and bioactivate aristolochic acidⅠ(AA-Ⅰ)to produce AA-Ⅰ-DNA adducts.METHODS①Human-induced hepatocytes(hiHeps)and human bladder RT4 cells were used as tool cells and treated with AA-Ⅰ0,0.5,1.0 and 2μmol·L^(-1)for 24 h.Cell viability was detected using the CCK-8 method,and the half maximal inhibition concentration(IC_(50))was calculated using the CCK-8 method and the level of DNA adduct production was calculated.②hiHeps and RT4 cells were treated with AKR inhibitor luteotin(0,5,10 and 25μmol·L^(-1))+AA-Ⅰ0.2 and 1.0μmol·L^(-1)for 24 h,respectively,and the levels of DNA adducts were detected by a liquid chromatography-tandem mass spectrometer(LC-MS/MS).③hiHeps cells were incubated with 80 nmol·L^(-1)small interfering RNAs(si-AKRs)for 48 h and treated with AA-Ⅰ1.0μmol·L^(-1)for 24 h.Real-time qualitative PCR(RT-qPCR)method was used to detect the mRNA expression of AKRs gene and LC-MS/MS technology was used to investigate the effect of specific AKR gene knockdown on DNA adduct levels.④500 nmol·L^(-1)human AKR recombinant proteins AKR1A1 and AA-Ⅰwere incubated in vitro under anaerobic conditions and the formation of AA-Ⅰ-DNA adducts was detected.RESULTS①The IC_(50)of AA-Ⅰto hiHeps and RT4 cells was 1.9 and 0.42μmol·L^(-1),respec⁃tively.The level of DNA adduct production of the two cell lines was significantly different(P<0.01).②Luteolin≥5μmol·L^(-1)significantly inhibited the production of AA-Ⅰ-DNA adducts in both cells(P<0.05),and there was a concentration-dependent effect in hiHeps cells(P<0.01,R=0.84).③In the AKR family,the knockdown of AKR1A1 gene up to 80%inhibited the generation of AA-Ⅰ-DNA adducts by 30%-40%.④The AA-Ⅰ-DNA adducts were detected in the incubation of recombinant protein AKR1A1 and AA-Ⅰunder anaerobic conditions in vitro,approximately 1 adduct per 107 nucleotides.CONCLU⁃SION AKR1A1 is involved in AA-Ⅰbioactivation,providing a reference for elucidation of the carcino⁃genic mechanism of AA-Ⅰ.

Dissecting Causal Relationships Between Plasma Metabolites and Osteoporosis:A Bidirectional Mendelian Randomization Study

Objective To investigate the causal relationships between plasma metabolites and osteoporosis via Mendelian randomization(MR) analysis.Methods Bidirectional MR was used to analyze pooled data from different genome-wide association studies(GWAS). The causal effect of plasma metabolites on osteoporosis was estimated using the inverse variance weighted method, intersections of statistically significant metabolites obtained from different sources of osteoporosis-related GWAS aggregated data was determined, and then sensitivity analysis was performed on these metabolites. Heterogeneity between single nucleotide polymorphisms was evaluated by Cochran's Q test. Horizontal pleiotropy was assessed through the application of the MR-Egger intercept method and the MRPRESSO method. The causal effect of osteoporosis on plasma metabolites was also evaluated using the inverse variance weighted method. Additionally, pathway analysis was conducted to identify potential metabolic pathways involved in the regulation of osteoporosis.Results Primary analysis and sensitivity analysis showed that 77 and 61 plasma metabolites had a causal relationship with osteoporosis from the GWAS data in the GCST90038656 and GCST90044600 datasets, respectively. Five common metabolites were identified via intersection. X-13684 levels and the glucose-to-maltose ratio were negatively associated with osteoporosis, whereas glycoursodeoxycholate levels and arachidoylcarnitine(C20) levels were positively associated with osteoporosis(all P < 0.05). The relationship between X-11299 levels and osteoporosis showed contradictory results(all P < 0.05). Pathway analysis indicated that glycine, serine, and threonine metabolism, valine, leucine, and isoleucine biosynthesis, galactose metabolism, arginine biosynthesis, and starch and sucrose metabolism pathways were participated in the development of osteoporosis.Conclusion We found a causal relationship between plasma metabolites and osteoporosis. These results offer novel perspectives with important implications for targeted metabolite-focused interventions in the management of osteoporosis.

Damage effect and mechanisms of cyclophosphamide to human neuroblastoma SH-SY5Y cells

OBJECTIVE To investigate the damage effect and mechanisms of cyclophosphamide(CTX)and its active metabolite derivative 4-hydroperoxycyclophosphamide(4-HC)to human neuroblas⁃toma SH-SY5Y cells.METHODS SH-SY5Y cells were treated with CTX[0(cell control),0.01,0.1,1,5,10,20,40 and 80 mmol·L^(-1)]and 4-HC[0(cell control),0.01,0.1,1,5,10,20,40 and 80μmol·L^(-1)]for 48 h.Cell confluence and morphology were observed by the IncuCyte ZOOM system.Cell viability was assessed by CCK-8 assay.Lactate dehydrogenase(LDH)release was measured by LDH assay kit.SH-SY5Y cells were treated with CTX(0,1,5,10 and 20 mmol·L^(-1))and 4-HC(0,1,5,10 and 20μmol·L^(-1))for 48 h before cell proliferation was analyzed by 5-ethynyl-2′-deoxyuridine(EdU)staining assay.Immunofluorescence was employed to assess the levels of the DNA double-strand break markerγ-H2AX and to evaluate changes in mitochondrial membrane potential.SH-SY5Y cells were treated with CTX(0,1,5 and 10 mmol·L^(-1))and 4-HC(0,1,5 and 10μmol·L^(-1))for 48 h,and the alterations in glycolysis and oxidative phosphorylation levels were analyzed using the Seahorse XFe96 Analyzer.RESULTS Compared with the cell control group,cell confluence and cell viability were significantly reduced in the CTX and 4-HC groups(P<0.01),and the half-maximal inhibitory concentrations(IC50)for CTX and 4-HC were 4.44 mmol·L^(-1) and 4.78μmol·L^(-1),respectively.The release rate of LDH was signif⁃icantly increased while the percentage of EdU+cells was significantly reduced in the CTX and 4-HC groups(P<0.01).The percentage ofγ-H2AX+cells was significantly increased and mitochondrial membrane potential significantly decreased in the CTX and 4-HC group(P<0.05).Treatment with CTX and 4-HC resulted in reduced levels of maximum glycolytic capacity,glycolytic reserve,maximal respi⁃ration,and ATP production(P<0.05).CONCLUSION CTX and 4-HC exert significant cytotoxic effects on SH-SY5Y cells by disrupting cell membrane structure,impeding cell proliferation,and reducing cell viability.The mechanisms underlying these effects may involve intracellular DNA damage,disturbance of energy metabolism and mitochondrial dysfunction.

Transcriptome Sequencing for Sugar and Flavonoid Metabolism in Prunus persica‘Jinxiangyu’

In this study,high performance liquid chromatography(HPLC)and RNA-seq transcriptome sequencing were used to study the changes in soluble sugar components and flavonoids in Prunus persica‘Jinxiangyu’at different developmental stages(20–90 d after flowering)and screen the key genes regulating the formation of soluble sugar and flavonoids in the fruits.The results showed that 60–85 d after flowering was the key stage of quality formation of Prunus persica‘Jinxiangyu’,and the content of soluble sugar,soluble solid,fructose,and sucrose in the fruit increased significantly during this period.The sugar content of ripe fruits was mainly fructose and sucrose.The content of kaempferol glycoside was low in the fruit.Quercetin glycoside content was higher in the young fruit stage and decreased with fruit maturity.There were no anthocyanin compounds in the fruit.The expression levels of genes involved in flavonoid metabolism(ANS,DFR,F3H,FLS,4CL1,etc.)were low in the fruit.A total of 181 differentially expressed genes were identified during fruit development to participate in five sugar metabolism pathways,among which the SDH gene had a higher expression level,which continuously rised in the later stage of fruit development.It mainly promoted the accumulation of fructose content in the later stage of fruit development.The expression levels of SPS1,SS,and SS1 genes were continuously up-regulated,which played a key role in sucrose regulation.The higher expression levels of SUS3 and INVA genes in the early stage of fruit development promoted the degradation of sucrose.

Comprehensive Understanding of Immune Cells in The Pathogenesis of Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease,defined by several phases,ranging from benign fat accumulation to non-alcoholic steatohepatitis(NASH),which can lead to liver cancer and cirrhosis.Although NAFLD is a disease of disordered metabolism,it also involves several immune cell-mediated inflammatory processes,either promoting and/or suppressing hepatocyte inflammation through the secretion of pro-inflammatory and/or anti-inflammatory factors to influence the NAFLD process.However,the underlying disease mechanism and the role of immune cells in NAFLD are still under investigation,leaving many open-ended questions.In this review,we presented the recent concepts about the interplay of immune cells in the onset and pathogenesis of NAFLD.We also highlighted the specific non-immune cells exhibiting immunological properties of therapeutic significance in NAFLD.We hope that this review will help guide the development of future NAFLD therapeutics.

Effect of surfactant Tween-80 on sulfur oxidation and expression of sulfur metabolism relevant genes of Acidithiobacillus ferrooxidans

The effects of surfactant Tween-80 on the growth, sulfur oxidation, and expression of selected typical sulfur metabolism relevant genes of Acidithiobacillus ferrooxidans ATCC 23270 were investigated. The results showed that in the presence of 10-2 g/L Tween-80, the growth of A. ferrooxidans and its metabolism on the insoluble substrate S0 and CuFeS2 were promoted. After 24 d of bioleaching, the copper extraction yield of chalcopyrite at 10-2 g/L Tween-80 increased by 16% compared with the bioleaching experiment without Tween-80. FT-IR spectra analysis revealed that the result was probably caused by the extracellular polymeric substances whose composition could be changed by the surfactant addition. RT-qPCR was used to analyze the differential expressions of 17 selected sulfur metabolism relevant genes in response to the addition of Tween-80. Down-regulation of the extracellular protein genes indicated the influence of Tween-80 on bacteria-sulfur adsorption. Variation of the expression level of the enzymes provided a supplement to sulfur metabolism investigation.

Relationship Between Polyamine Metabolism in Roots and Salt Tolerance of Barley Seedlings

Plant growth rate (GR), contents of free polyamines (fPAs) and bound polyamines (bPAs) and activities of some key enzymes involved in polyamine (PA) metabolism in the roots of two barley (Hordeum valgare L.) cultivars differing in salt sensitivity were investigated with 0-300 mmol/L NaCl treatments. With 0-200 mmol/L NaCl treatments, activities of arginine decarboxylase (ADC) and transglutaminase (TGase) and PA oxidase (PAO) in the roots of barley seedlings all increased, while TGase and PAO activities decreased slightly at 300 mmol/L NaCl. As a result, free Put (fPut) content increased continuously with increasing concentrations of NaCl, while levels of free Spd (fSpd) and an unknown PA (fPAx) and bPAs (bPut, bSpd and bPAx), as well as (fSpd + fPAx)/fPut ratio rose at 50-200 mmol/L NaCl and reduced at 300 mmol/L NaCl. However, no significant change in the tetra-amine spermine (Spin) content was observed. Statistical analysis showed that GR was very significantly positively correlated with (fSpd + fPAx)/fPut ratios and the contents of bPAs, whereas a significant inverse correlation existed between GR and the ratios of fPA contents to bPA levels. These results showed that, under salt stress, the balance between fSpd, fPAx and fPut levels and an equipoise between fPA and bPA contents in roots were important to salt tolerance of barley seedlings.

Chemical Constituents from Starfish Asterias rollestoni

Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.

Metabolism and thermoregulation between Mrs Hume's Pheasant(Syrmaticus humiae) and Elliot's Pheasant(S.ellioti)

To understand metabolic adaptations,the basal metabolic rate（BMR） of Mrs Hume＇s Pheasant（Syrmaticus humiae） and Elliot＇s Pheasant（Syrmaticus ellioti） were investigated.Metabolic rate（MR）,body temperature（Tb） and thermal conductance（C） were determined in both species at a temperatrue range of 5-35 ℃,respectively.Oxygen consumption was measured with a closed circuit respirometer.The thermal neutral zones（TNZ） were 24.5-31.6 ℃,and 23.0-29.2 ℃,respectively.With a temperature range of 5-35 ℃,Mrs Hume＇s Pheasant and Elliot＇s Pheasant could maintained stable Tb at a mean of（40.47±0.64） and（40.36±0.10） ℃,respectively.Mean BMRs within TNZs were（1.36±0.84） mLO2/（g.h） for Mrs Hume＇s Pheasant and（2.03±0.12） mLO2/（g.h） for Elliot＇s Pheasant,which were 77% and 86% of the expected value based on their body mass,respectively.Thermal conductance of Mrs Hume＇s Pheasant and Elliot＇s Pheasant were（0.12±0.01） and（0.17±0.01） mLO2/（g.h.℃）,below the lower critical temperature,respectively,which were 119% and 124% of the expected value based on their body mass,respectively.The ecophysiological characteristics of these species were low metabolic rate,high body temperature,and high thermal conductance,which allow both species to better adapt to the warmer climate environment in south China.

Participation of H_2O_2 in Enhancement of Cold Chilling by Salicylic Acid in Banana Seedlings

The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3-0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H 2O 2 metabolism. Compared with water_treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H 2O 2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H 2O 2 and thiobarbituric acid_reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H 2O 2 treatments (1.5 -2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H 2O 2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H 2O 2 may be required for SA_enhanced cold tolerance. The significance of the interaction of SA, H 2O 2 and H 2O 2_metabolizing enzymes during cold stress has been discussed.

Environmental Stresses and Redox Status of Ascorbate

To investigate the effects of environmental stresses on ascorbic acid content and its redox status, the effects of freezing and drought on ascorbate and dehydro-ascorbate content and activities of four enzymes involved in the ascorbate-glutathione cycle in some conifers were studied. The results showed that both freezing and drought induced the decrease in ascorbate content and the increase in dehydro-ascorbate content. The activities of ascorbate peroxidase (APX) and monodehydro-ascorbate reductase (MDAR) were decreased by freezing stress. At the beginning of exposure to air, water loss from detached needles induced the increase in the activities of APX and MDAR. Further water loss turned to decrease the APX and MDAR activities. The activities of dehydro-ascorbate reductase (DHAR) and glutathione reductase (GR) were not sensitive to changes in temperature and water content of the needles. It is concluded that moderate temperature or water stresses may induce the acclimation and increase in the ability of the H2O2 scavenging system, while strong stresses decrease the ability and induce injury of plant tissues. Correlation between ascorbate content and activities of related enzymes and cold tolerance of conifers were also reported.

Review on hygienical components of sweet potato and their functions

Sweet potato not only contains primary materials such as dietary fiber, vitamin and soluble protein, but also provides abundant secondary metabolic products which have hygienical functions, like caffeic acid and caffeoylqinic acid derivatives, and anthocyanins, carotanoids. Many studies showed that many secondary products of sweet potato have hygienical functions as quenching free radicals, antioxidation, and preventing cancer, cardiovascular disease and diabetes. Further understanding of the hygienical functions of components in sweet potato is considered to be one of the important factors for developing new uses of sweet potato.