Objective:To investigate the effect of isoimperatorin on histopathological and biochemical changes in acetic acid-induced colitis rats.Methods:Colitis was induced by intracolonic administration of acetic acid solution...Objective:To investigate the effect of isoimperatorin on histopathological and biochemical changes in acetic acid-induced colitis rats.Methods:Colitis was induced by intracolonic administration of acetic acid solution(4%v/v)in rats.Rats were divided into six groups including the sham group,the negative control group,the dexamethasone-treated group,and the groups treated with isoimperatorin(0.1,1,and 10 mg/kg/d by gavage).The treatments were administered for three days and then colonic status was assessed by macroscopic,histopathological,and biochemical analyses.Results:Isoimperatorin significantly alleviated colonic damage in a dose-dependent manner and improved histological changes in rats with acetic acid-induced colitis.It also significantly reduced myeloperoxidase,TNF-α,IL-1β,and malodialdehyde levels.Conclusions:Isoimperatorin alleviates acetic acid-induced colitis in rats and may be a potential therapeutic agent for the treatment of colitis.展开更多
Mg-air batteries have attracted tremendous attention as a potential next-generation power source for portable electronics and e-transportation due to their remarkable high theoretical volumetric energy density,environ...Mg-air batteries have attracted tremendous attention as a potential next-generation power source for portable electronics and e-transportation due to their remarkable high theoretical volumetric energy density,environmental sustainability,and cost-effectiveness.However,the fast hydrogen evolution reaction(HER)in NaCl-based aqueous electrolytes impairs the performance of Mg-air batteries and leads to poor specific capacity,low energy density,and low utilization.Thus,the conventionally used NaCl solute was proposed to be replaced by NaNO_(3)and acetic acid additive as a corrosion inhibitor,therefore an electrolyte engineering for long-life time Mg-air batteries is reported.The resulting Mg-air batteries based on this optimized electrolyte demonstrate an improved discharge voltage reaching~1.8 V for initial 5 h at a current density of 0.5 mA/cm^(2) and significantly prolonged cells'operational lifetime to over 360 h,in contrast to only~17 h observed in NaCl electrolyte.X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry were employed to analyse the composition of surface film and scanning electron microscopy combined with transmission electron microscopy to clarify the morphology changes of the surface layer as a function of acetic acid addition.The thorough studies of chemical composition and morphology of corrosion products have allowed us to elucidate the working mechanism of Mg anode in this optimized electrolyte for Mg-air batteries.展开更多
BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against...BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against conventional therapies.Gossypol acetic acid(GAA),which is extracted from the seeds of cotton plants,exerts anti-tumor roles in several types of cancer and has been reported to induce apoptosis of LSCs by inhibiting Bcl2.AIM To investigate the exact roles of GAA in regulating LSCs under different microenvironments and the exact mechanism.METHODS In this study,LSCs were magnetically sorted from AML cell lines and the CD34+CD38-population was obtained.The expression of leucine-rich pentatricopeptide repeat-containing protein(LRPPRC)and forkhead box M1(FOXM1)was evaluated in LSCs,and the effects of GAA on malignancies and mitochondrial RESULTS LRPPRC was found to be upregulated,and GAA inhibited cell proliferation by degrading LRPPRC.GAA induced LRPPRC degradation and inhibited the activation of interleukin 6(IL-6)/janus kinase(JAK)1/signal transducer and activator of transcription(STAT)3 signaling,enhancing chemosensitivity in LSCs against conventional chemotherapies,including L-Asparaginase,Dexamethasone,and cytarabine.GAA was also found to downregulate FOXM1 indirectly by regulating LRPPRC.Furthermore,GAA induced reactive oxygen species accumulation,disturbed mitochondrial homeostasis,and caused mitochondrial dysfunction.By inhibiting IL-6/JAK1/STAT3 signaling via degrading LRPPRC,GAA resulted in the elimination of LSCs.Meanwhile,GAA induced oxidative stress and subsequent cell damage by causing mitochondrial damage.CONCLUSION Taken together,the results indicate that GAA might overcome the BMM protective effect and be considered as a novel and effective combination therapy for AML.展开更多
BACKGROUND Conventional magnifying endoscopy with narrow-band imaging(NBI)observation of the gastric body mucosa shows dominant patterns in relation to the regular arrangement of collecting venules,subepithelial capil...BACKGROUND Conventional magnifying endoscopy with narrow-band imaging(NBI)observation of the gastric body mucosa shows dominant patterns in relation to the regular arrangement of collecting venules,subepithelial capillary network,and gastric pits.AIM To evaluate the effectiveness of a new one-dual(near)focus,NBI mode in the assessment of the microscopic features of gastric body mucosa compared to conventional magnification.METHODS During 2021 and 2022,68 patients underwent proximal gastrointestinal endoscopy using magnification endoscopic modalities subsequently applying acetic acid(AA).The GIF-190HQ series NBI system with dual focus capability was used for the investigation of gastric mucosa.At the time of the endoscopy,the gastric body mucosa of all enrolled patients was photographed using the white light endoscopy(WLE),near focus(NF),NF-NBI,AA-NF,and AA-NF-NBI modes.RESULTS The WLE,NF and NF-NBI endoscopic modes for all patients(204 images)were classified in the same order into three groups.Two images from each patient for the AA-NF and AA-NF-NBI endoscopic modes were classified in the same order.According to all three observers who completed the work independently,NF magnification was significantly superior to WLE(P<0.01),and the NF-NBI mode was significantly superior to NF magnification(P<0.01).After applying AA,the three observers confirmed that AA-NF-NBI was significantly superior to AA-NF(P<0.01).Interobserver kappa values for WLE were 0.609,0.704,and 0.598,respectively and were 0.600,0.721,and 0.637,respectively,for NF magnification.For the NF-NBI mode,the values were 0.378,0.471,and 0.553,respectively.For AA-NF,they were 0.453,0.603,and 0.480,respectively,and for AA-NF-NBI,they were 0.643,0.506,and 0.354,respectively.CONCLUSION When investigating gastric mucosa in microscopic detail,NF-NBI was the most powerful endoscopic mode for assessing regular arrangement of collecting venules,subepithelial capillary network,and gastric pits among the five endoscopic modalities investigated in this study.AA-NF-NBI was the most powerful endoscopic mode for analyzing crypt opening and intervening part.展开更多
It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and co...It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and countermeasures were needed. Therefore, we studied the copper corrosion caused by acetic acid. The present work investigated the relationship between the corrosion form of copper and acetic acid concentration using phosphorous-deoxidized copper, and reported that hemispherical corrosion was observed at acetic acid concentrations of 0.01 to 1 vol.% (0.002 to 0.2 mol·L<sup>-1</sup>) in the immersion test. In this study, the effects of acetic acid and phosphate on copper corrosion were examined using oxygen-free copper in immersion tests. The results suggested that different concentrations of phosphate in acetic acid solutions and the presence or absence of acetic acid and phosphate affected the corrosion of copper, resulting in different corrosion forms and corrosion progress.展开更多
BACKGROUND Atractylodes japonica Koidz.ex Kitam.(A.japonica,Chinese name:Guan-Cangzhu,Japanese name:Byaku-jutsu),a perennial herb,which is mainly distributed in northeast area of China,it’s often used to treat digest...BACKGROUND Atractylodes japonica Koidz.ex Kitam.(A.japonica,Chinese name:Guan-Cangzhu,Japanese name:Byaku-jutsu),a perennial herb,which is mainly distributed in northeast area of China,it’s often used to treat digestive system diseases such as gastric ulcer(GU).However,the mechanism of its potential protective effects against GU remains unclear.AIM To investigate the protective effects of A.japonica on acetic acid-induced GU rats.METHODS The chemical constituents of A.japonica were determined by ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)analysis.The rat model of GU was simulated by acetic acid method.The pathological changes of gastric tissues were evaluated by hematoxylin-eosin stain,the levels of epidermal growth factor(EGF),EGF receptor(EGFR),nuclear factor kappa-B(NF-κB),interleukin-1β(IL-1β),IL-10,Na^(+)-K^(+)-ATPase(NKA)in serum and gastric tissues were determined by enzyme-linked immunosorbent assay,and the mRNA expressions of EGFR,NF-κBp65,IkappaBalpha(IκBα)and Zonula Occludens-1(ZO-1)in gastric tissues were determined by real-time reverse transcription polymerase chain reaction,and the efficacy was observed.Then,plasma metabolomic analysis was performed by UPLC-MS/MS to screen the specific potential biomarkers,metabolic pathways and to explore the possible mechani-sms.RESULTS 48 chemical constituents were identified.Many of them have strong pharmacological activity,the results also revealed that A.japonica significantly improved the pathological damage of gastric tissues,increased the expression levels of IL-10,IκBαrelated to anti-inflammatory factors,decreased the expression levels of IL-1β,NF-κB,NF-κBp65,related to proinflammatory factors,restored the levels of factors about EGF,EGFR,ZO-1 associated with ulcer healing and the levels of factors about NKA associated with energy metabolism.Metabolomic analysis identified 10 potential differential metabolites and enriched 7 related metabolic pathways.CONCLUSION These findings contribute to the understanding of the potential mechanism of A.japonica to improve acetic acidinduced GU,and will be of great importance for the development and clinical application of natural drugs related to A.japonica.展开更多
<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> It is not well analyze...<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> It is not well analyzed whether there are differences in plasma levels of tryptophan (TRP) metabolites between healthy control people (HC) and patients of major monopolar depression (MMD). </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Ultra high-speed </span></span><span style="font-family:""><span style="font-family:Verdana;">liquid chromatography/mass spectrometry has been used for the simultaneous determination of plasma levels of tryptophan metabolites in depressive </span><span><span style="font-family:Verdana;">patients. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> There are no significant differences between plasma levels of TRP between HC and MMD. Plasma levels of TRP of HC are higher in young men, young women, old men, and old women in this order. Serotonin (5-HT) levels are higher in MMD than HC. Plasma levels of 5-HIAA of HC are also higher than those of patients of MMD. Plasma levels of kynurenine (KYN) of healthy old men and old women are higher than those of young men and old women. Plasma levels of KYN are higher in old women and young men of MMD than those of HC. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> Plasma levels of 5-HT are higher in patients of MMD than those of HC, which may suggest that use of drugs inhibiting the 5-HT transportation may increase plasma levels of 5-HT in MMD.展开更多
A novel Zn(Ⅱ) complex, [ZnL_2(H_2O)_4]·H_2O(1, HL = 2-(nicotinoyloxy)acetic acid), was synthesized using Zn(OAc)_2·2H_2O and 2-(nicotinoyloxy)acetic acid as raw materials. Its structure has been elucidated ...A novel Zn(Ⅱ) complex, [ZnL_2(H_2O)_4]·H_2O(1, HL = 2-(nicotinoyloxy)acetic acid), was synthesized using Zn(OAc)_2·2H_2O and 2-(nicotinoyloxy)acetic acid as raw materials. Its structure has been elucidated by elemental analysis, IR and single-crystal X-ray diffraction. The structural analysis revealed that complex 1 crystallizes in triclinic, space group P1 and the Zn(Ⅱ) atom is six-coordinated with two N atoms from two different 2-(nicotinoyloxy)acetate anion ligands and four O atoms from coordinated water molecules. Complex 1 forms a 3D network structure by O–H···O hydrogen bonds. The antitumor activities of 2-(nicotinoyloxy)acetic acid ligand and its Zn(Ⅱ) complex were evaluated against human lung adenocarcinoma A549 cells, human hepatoma SMMC-7721 cells and human colon carcinoma Wi Dr cells.展开更多
Objective: To investigate the anti-colitic effects of diet containing seeds of Buchholzia coriacea(B. coriacea) on acetic acid induced ulcerative colitis. Methods: Male Wistar rats(70-100 g) were fed with standard die...Objective: To investigate the anti-colitic effects of diet containing seeds of Buchholzia coriacea(B. coriacea) on acetic acid induced ulcerative colitis. Methods: Male Wistar rats(70-100 g) were fed with standard diets(control group) or with same diet containing B. coriacea seeds at 12.5% or 25% for six weeks. At the sixth week, colitis was induced by intra-rectal administration of 1 mL/200 g 6% acetic acid. Animals were sacrificed at days 0(before induction), 1, 3 and 7 post induction to assess disease severity via evaluation of stool consistency, haematological variables and histomorphometry of colon tissues. Results: A significant increase in body weight was observed in the 12.5% B. coriacea fed group compared to the control. B. coriacea significantly reduced stool consistency and microscopic scores. Histological evaluation revealed significantly decreased inflammatory aggregates in B. coriacea fed groups compared to control after colitis induction. There was a significant decrease in packed cell volume, red blood cell and haemoglobin concentration in the control group at day 1 post colitis induction compared to 12.5% B. coriacea fed groups. Neutrophils and white blood cell were also significantly increased after colitis induction in the control group while these were significantly decreased in the B. coriacea fed groups. Conclusions: The addition of B. coriacea seeds to diets promotes healing of acetic acid induced colitis by suppressing infiltration of inflammatory aggregates and ameliorating anemia.展开更多
Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsol...Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsola imbricata was characterized by HPLC.Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200μL,7.5%acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays.The levels of malondialdehyde,glutathione peroxidase 1,superoxide dismutase,and catalase were determined in colon tissues.Proinflammatory cytokines including interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were quantified by ELISA.The extent of tissue damage was assessed by histological analysis.Results:Phytochemical analysis confirmed the presence of phytochemicals including quercetin,gallic acid,syringic acid,benzoic acid and chlorogenic acid in the crude extract.The crude extract of Salsola imbricata(300 and 500 mg/kg)markedly decreased malondialdehyde and nitric oxide(P<0.01)and increased antioxidant activities of glutathione peroxidase 1(P<0.001)and superoxide dismutase(P<0.001).Moreover,it decreased the levels of IL-1β,IL-6 and TNF-αsignificantly(P<0.001)and reduced the damage to the colon mucosa,promoting tissue healing and regeneration.Conclusions:Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.展开更多
Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained w...Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained with selectivity of 82.7% and once-through space time yield (STY) of 257.4 g/h(L.展开更多
Objective To investigate the effect of naphthalene acetic acid(NAA) on proliferation and apoptosis of mice hepatocytes.Methods Fifty mice were randomly divided into five groups: positive control,normal control,low,mid...Objective To investigate the effect of naphthalene acetic acid(NAA) on proliferation and apoptosis of mice hepatocytes.Methods Fifty mice were randomly divided into five groups: positive control,normal control,low,middle and high dose of NAA groups.Mice in low,middle and high dose of naphthalene acetic acid groups were fed with 200 mg/kg,1 000 mg/kg and 5 000 mg/kg NAA animal food,respectively.Mice in positive control,normal control groups were fed with usual animal food.After 4 weeks,mice were sacrificed and liver was separated.Three days before scarification,mice in positive control group were given 20 mg/kg ascyclophosphami daily by intraperitoneal injection.The proliferative activity of hepatocytes was detected by MTT assay.The expressions of PCNA protein and Caspase-3 were measured by immunohistochemistry method.Results The proliferative activities of mice hepatocytes in high dose group and normal control group were 0.794±0.019 and 1.055±0.019, respectively.The expressions of PCNA protein and Caspase-3 in high dose group were 11.2% and 37.9%,and those in the normal group were 33.1% and 6.3%, respectively.All differences were significant(P<0.01).Conclusion High dose of NAA acid could significantly inhibit proliferation and increase apoptosis of hepatocytes in mice.展开更多
Sourdough starters for making traditional steamed bread are rich in microbes.Studies have shown that,in addition to yeast and lactic acid bacteria(LAB),acetic acid bacteria(AAB)are other functional species in sourdoug...Sourdough starters for making traditional steamed bread are rich in microbes.Studies have shown that,in addition to yeast and lactic acid bacteria(LAB),acetic acid bacteria(AAB)are other functional species in sourdough,but the influences of AAB on the properties of sourdough and steamed bread were rarely reported.This study aimed to assess the effects of a selected strain of acetic acid bacterium on the properties of sourdough and steamed bread.Sourdoughs and steamed breads were prepared from five different starter cultures,marked as CK(control check,with no starters),Y(only yeast),YL(yeast+LAB),YA(yeast+AAB)and YLA(yeast+LAB+AAB),and their properties were determined.The results of sour dough properties showed that the YLA sourdough had the highest total titratable acid of 14.6 mL and the lowest pH of 3.87 compared with the other groups after fermentation to 8 h;and the YLA sourdough had the greatest elasticity and viscosity.The results of quality properties of steamed bread revealed that the L*value(88.40±0.09)of the YA steamed bread was significantly higher than those of the YLA and YL steamed breads;the YLA steamed bread had the highest specific volume and the highest sensory score of 89.6±3.31 in comparison to those of the other groups;the hardness and chewiness of YLA and YA steamed breads were significantly lower than those of the other groups.Volatile compounds in the steamed breads were also determined by SPME-GC-MS.A total of 42 flavor substances were detected,including 3 kinds of alcohols,8 kinds of aldehydes,7 kinds of ketones,2 kinds of acids,15 kinds of esters,1 furan,and 6 kinds of other types of compounds,mainly alkanes and esters,followed by alcohols and aldehydes.The YLA steamed bread was richer in esters,aldehydes,and acids than those from the other treatment groups.By contrast,alkanes and aldehydes were dominant in the Y and YL steamed breads.Therefore,the flavor and quality of the steamed bread made from the YLA sourdough could be improved obviously.These results could provide references for the application of AAB in dough fermentation and the improvement of new kinds of starters.展开更多
This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-...This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-family:"">Dam</span><span style="font-family:"">ascus, to reduce fruit drop of sweet cherry. The experiment included 4 foliar applications: T1: control, T2: GA<sub>3</sub> (100 ppm), T3: NAA (20 <span>ppm), T4: (100 ppm GA<sub>3</sub> + 20 ppm NAA). Fruit set and fruit drop pe</span>rcentage, fruiting factor, and yield were recorded. The results showed that treatment with (100 ppm GA<sub>3</sub> + 20 ppm NAA) recorded higher fruit set percentage (73.81% and 75.62%), and fruiting factor (48.38% and 50.04%) respectively</span><span style="font-family:"">;</span><span style="font-family:""> <span>In addition to fruit yield (40.19 and 41.21 kg/tree) for both cultivars, co</span>mpared to the control (9.13, 6.60 kg/tree). Therefore, it can be concluded that GA<sub>3</sub> + NAA treatment reduced Sweet cherry fruit drop better than other treatments, <span>where fruit drop percentage didn’t exceed (63.11% and 62.01%) in both cu</span>ltivars (Bing and Hardy Giant) respectively, compared to the control (80.92% and 80.64%).展开更多
It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative...It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative bacteria. In this study, we evaluated the effects of intake of Gluconacetobacter hansenii GK-1 (GK-1), Gram-negative acetic acid bacteria, for 12 weeks on physical condition and immune indices. We conducted a randomized, double-blind, placebo-controlled, parallel-group study in 100 healthy adults. The subjects were randomized into the GK-1 and the placebo groups. The diary-administered physical condition survey was conducted during the study period. The evaluation of salivary sIgA levels, NK-cell activity, and serum IFN-γ levels and quality of life survey was conducted before, in 6 weeks, and 12 weeks after the start of ingestion. Based on the physical condition survey, the cumulative onset-days of symptoms were significantly suppressed in the GK-1 group compared to the placebo group regarding the evaluation of 13 symptoms related to immunity, every 3 weeks. Additionally, salivary sIgA levels per hour were significantly increased in the GK-1 group compared with the placebo group at 6 and 12 weeks. Despite no significant differences in the NK-cell activity, serum IFN-γ levels or quality of life survey between the groups. Serum IFN-γ levels in the GK-1 group were significantly elevated at 12 weeks after the start of ingestion compared with those before ingestion. In conclusion, intake of GK-1 was shown to increase salivary sIgA levels and improve physical condition. This suggested that oral intake of GK-1 may help maintain the immune system.展开更多
Fruit vinegar is a new beverage emerging in recent years because of its rich nutrition. At present, acetic acid bacteria are main strains used in the fruit vinegar production. Acetic acid bacteria are a general term f...Fruit vinegar is a new beverage emerging in recent years because of its rich nutrition. At present, acetic acid bacteria are main strains used in the fruit vinegar production. Acetic acid bacteria are a general term for a class of bacteria that can oxidize ethanol to acetic acid. This paper mainly summarized the biological characteristics and research status of acetic acid bacteria for fruit vinegar brewing, in order to provide a theoretical basis for the selection of high-quality acetic acid bacteria for fruit vinegar brewing.展开更多
Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate...Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate the thermo-ethanol-acid tolerance characters of five AAB strains (VMA1, VMA5, VMA7, VMAM, VMAO) previously isolated from fermented mango alcohol and belonging to Gluconoacetobacter genera. As result, the five AAB strains exhibited good growth and acid production at temperatures up to 45°C;they could tolerate and produce acetic acid at ethanol concentrations up to 20% (v/v). In addition, the studied strains showed growth at acetic acid concentrations up to 4.5% (w/v). Strains VMA7 and VMAO showed the highest resistance properties: they demonstrated acid production at 50°C and VMAO could even grow at 60°C;they tolerated and produced acetic acid at 25% (v/v) ethanol concentration;they showed resistance to acetic acid concentrations up to 6% (w/v). Considering all these properties, the use of these strains would seriously contribute to improving the quality of the vinegar produced and help to reduce the cooling water feeds in vinegar production especially in hot countries in the context of global warming.展开更多
From January 1995 to December 2004, 860 rainwater samples were collected in the humid savannah of Lamto. Using the Henry’s law, we determined the content of formic and acetic acids in the air based on their concentra...From January 1995 to December 2004, 860 rainwater samples were collected in the humid savannah of Lamto. Using the Henry’s law, we determined the content of formic and acetic acids in the air based on their concentrations in rainwater. The annual partial pressure of both formic and acetic acids over the decade is variable. It covers a range of 0.003 (1998) to 0.21 ppbv (1996) and 0.27 (1999) to 0.47 ppbv (1996) for formic and acetic acids respectively. Also, the partial pressure in the dry season is higher than that in the wet season. This difference is related to the enrichment of the organic acid content in the air by the various sources that produce these acids. One of the main sources of increment in organic acid is biomass burning. This biomass burning contributes between 21% and 51% to the formation of the two acids in the humid savannah of Lamto. Ultimately the average annual organic acidity varies from 40% to 60% over the ten years period.展开更多
Submicrometer sized pure cubic phase,Eu^(3+)doped,and Yb^(3+)/Er^(3+)co-dopedα-NaYF4 particles with octahedral morphology have been prepared in acetic acid.The acetate anion plays a critical role in the formation of ...Submicrometer sized pure cubic phase,Eu^(3+)doped,and Yb^(3+)/Er^(3+)co-dopedα-NaYF4 particles with octahedral morphology have been prepared in acetic acid.The acetate anion plays a critical role in the formation of such symmetric octahedral structures through its selective adsorption on the(111)faces of the products.The size of the as-prepared octahedra can be tuned by varying the amount of sodium acetate added to the acetic acid.A possible formation mechanism for these octahedra has been proposed.The dopedα-NaYF_(4) octahedral submicrometer particles show down-conversion and up-conversion photoluminescence typical of these materials.展开更多
Acetic acid is the main component of the volatile acid in the wine.However,excessive amounts of acetic acid negatively affect wine quality.The study aimed to decrease acetic acid content produced by Saccharomyces cere...Acetic acid is the main component of the volatile acid in the wine.However,excessive amounts of acetic acid negatively affect wine quality.The study aimed to decrease acetic acid content produced by Saccharomyces cerevisiae fermentation after adding metal ion at different temperatures.Response surface methodology(RSM)was used to predict the optimum conditions for acetic acid removal.A central composite design was employed for the experiments and results were analyzed to obtain the best possible combination of fermentation temperature(X1:16℃-24℃)and concentrations of potassium(X2:0-12.0 mM),magnesium(X3:0-8.0 mM),and calcium ions(X4:0-0.2 mM)that would generate the minimum acetic acid in lychee wine at an initial acetic acid concentration of 1.5 g/L.Experimental data were fitted to a second-order polynomial equation using multiple regression analysis and analyzed using analysis of variance(ANOVA).During fermentation under pre-established conditions,the correlation coefficients R2 and Adj-R2 of the models for acetic acid removal were 0.9487 and 0.9007,respectively.After testing,the optimum conditions for acetic acid removal were determined as follows:fermentation temperature of 20℃;potassium,magnesium,and calcium ion concentrations of 10.1 mM,6.1 mM,and 0.2 mM,respectively.The experimental acetic acid content of lychee wine under optimal conditions was found to be 0.309 g/L,which agreed well with the model-predicted value of 0.314 g/L.展开更多
文摘Objective:To investigate the effect of isoimperatorin on histopathological and biochemical changes in acetic acid-induced colitis rats.Methods:Colitis was induced by intracolonic administration of acetic acid solution(4%v/v)in rats.Rats were divided into six groups including the sham group,the negative control group,the dexamethasone-treated group,and the groups treated with isoimperatorin(0.1,1,and 10 mg/kg/d by gavage).The treatments were administered for three days and then colonic status was assessed by macroscopic,histopathological,and biochemical analyses.Results:Isoimperatorin significantly alleviated colonic damage in a dose-dependent manner and improved histological changes in rats with acetic acid-induced colitis.It also significantly reduced myeloperoxidase,TNF-α,IL-1β,and malodialdehyde levels.Conclusions:Isoimperatorin alleviates acetic acid-induced colitis in rats and may be a potential therapeutic agent for the treatment of colitis.
基金the China Scholarship Council(CSC)for funding(no.201806310116)。
文摘Mg-air batteries have attracted tremendous attention as a potential next-generation power source for portable electronics and e-transportation due to their remarkable high theoretical volumetric energy density,environmental sustainability,and cost-effectiveness.However,the fast hydrogen evolution reaction(HER)in NaCl-based aqueous electrolytes impairs the performance of Mg-air batteries and leads to poor specific capacity,low energy density,and low utilization.Thus,the conventionally used NaCl solute was proposed to be replaced by NaNO_(3)and acetic acid additive as a corrosion inhibitor,therefore an electrolyte engineering for long-life time Mg-air batteries is reported.The resulting Mg-air batteries based on this optimized electrolyte demonstrate an improved discharge voltage reaching~1.8 V for initial 5 h at a current density of 0.5 mA/cm^(2) and significantly prolonged cells'operational lifetime to over 360 h,in contrast to only~17 h observed in NaCl electrolyte.X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry were employed to analyse the composition of surface film and scanning electron microscopy combined with transmission electron microscopy to clarify the morphology changes of the surface layer as a function of acetic acid addition.The thorough studies of chemical composition and morphology of corrosion products have allowed us to elucidate the working mechanism of Mg anode in this optimized electrolyte for Mg-air batteries.
文摘BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against conventional therapies.Gossypol acetic acid(GAA),which is extracted from the seeds of cotton plants,exerts anti-tumor roles in several types of cancer and has been reported to induce apoptosis of LSCs by inhibiting Bcl2.AIM To investigate the exact roles of GAA in regulating LSCs under different microenvironments and the exact mechanism.METHODS In this study,LSCs were magnetically sorted from AML cell lines and the CD34+CD38-population was obtained.The expression of leucine-rich pentatricopeptide repeat-containing protein(LRPPRC)and forkhead box M1(FOXM1)was evaluated in LSCs,and the effects of GAA on malignancies and mitochondrial RESULTS LRPPRC was found to be upregulated,and GAA inhibited cell proliferation by degrading LRPPRC.GAA induced LRPPRC degradation and inhibited the activation of interleukin 6(IL-6)/janus kinase(JAK)1/signal transducer and activator of transcription(STAT)3 signaling,enhancing chemosensitivity in LSCs against conventional chemotherapies,including L-Asparaginase,Dexamethasone,and cytarabine.GAA was also found to downregulate FOXM1 indirectly by regulating LRPPRC.Furthermore,GAA induced reactive oxygen species accumulation,disturbed mitochondrial homeostasis,and caused mitochondrial dysfunction.By inhibiting IL-6/JAK1/STAT3 signaling via degrading LRPPRC,GAA resulted in the elimination of LSCs.Meanwhile,GAA induced oxidative stress and subsequent cell damage by causing mitochondrial damage.CONCLUSION Taken together,the results indicate that GAA might overcome the BMM protective effect and be considered as a novel and effective combination therapy for AML.
文摘BACKGROUND Conventional magnifying endoscopy with narrow-band imaging(NBI)observation of the gastric body mucosa shows dominant patterns in relation to the regular arrangement of collecting venules,subepithelial capillary network,and gastric pits.AIM To evaluate the effectiveness of a new one-dual(near)focus,NBI mode in the assessment of the microscopic features of gastric body mucosa compared to conventional magnification.METHODS During 2021 and 2022,68 patients underwent proximal gastrointestinal endoscopy using magnification endoscopic modalities subsequently applying acetic acid(AA).The GIF-190HQ series NBI system with dual focus capability was used for the investigation of gastric mucosa.At the time of the endoscopy,the gastric body mucosa of all enrolled patients was photographed using the white light endoscopy(WLE),near focus(NF),NF-NBI,AA-NF,and AA-NF-NBI modes.RESULTS The WLE,NF and NF-NBI endoscopic modes for all patients(204 images)were classified in the same order into three groups.Two images from each patient for the AA-NF and AA-NF-NBI endoscopic modes were classified in the same order.According to all three observers who completed the work independently,NF magnification was significantly superior to WLE(P<0.01),and the NF-NBI mode was significantly superior to NF magnification(P<0.01).After applying AA,the three observers confirmed that AA-NF-NBI was significantly superior to AA-NF(P<0.01).Interobserver kappa values for WLE were 0.609,0.704,and 0.598,respectively and were 0.600,0.721,and 0.637,respectively,for NF magnification.For the NF-NBI mode,the values were 0.378,0.471,and 0.553,respectively.For AA-NF,they were 0.453,0.603,and 0.480,respectively,and for AA-NF-NBI,they were 0.643,0.506,and 0.354,respectively.CONCLUSION When investigating gastric mucosa in microscopic detail,NF-NBI was the most powerful endoscopic mode for assessing regular arrangement of collecting venules,subepithelial capillary network,and gastric pits among the five endoscopic modalities investigated in this study.AA-NF-NBI was the most powerful endoscopic mode for analyzing crypt opening and intervening part.
文摘It was reported that hemispheric corrosion occurred in copper tubes in an acetic acid environment. When hemispheric corrosion occurred, corrosion could easily progress if water then flowed into the copper pipe, and countermeasures were needed. Therefore, we studied the copper corrosion caused by acetic acid. The present work investigated the relationship between the corrosion form of copper and acetic acid concentration using phosphorous-deoxidized copper, and reported that hemispherical corrosion was observed at acetic acid concentrations of 0.01 to 1 vol.% (0.002 to 0.2 mol·L<sup>-1</sup>) in the immersion test. In this study, the effects of acetic acid and phosphate on copper corrosion were examined using oxygen-free copper in immersion tests. The results suggested that different concentrations of phosphate in acetic acid solutions and the presence or absence of acetic acid and phosphate affected the corrosion of copper, resulting in different corrosion forms and corrosion progress.
基金Supported by National Natural Science Foundation of China,No.81973478Liaoning Revitalization Talents Program,China,No.XLYC2002004Natural Science Foundation of Liaoning Province,China,No.2019-ZD-0443.
文摘BACKGROUND Atractylodes japonica Koidz.ex Kitam.(A.japonica,Chinese name:Guan-Cangzhu,Japanese name:Byaku-jutsu),a perennial herb,which is mainly distributed in northeast area of China,it’s often used to treat digestive system diseases such as gastric ulcer(GU).However,the mechanism of its potential protective effects against GU remains unclear.AIM To investigate the protective effects of A.japonica on acetic acid-induced GU rats.METHODS The chemical constituents of A.japonica were determined by ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)analysis.The rat model of GU was simulated by acetic acid method.The pathological changes of gastric tissues were evaluated by hematoxylin-eosin stain,the levels of epidermal growth factor(EGF),EGF receptor(EGFR),nuclear factor kappa-B(NF-κB),interleukin-1β(IL-1β),IL-10,Na^(+)-K^(+)-ATPase(NKA)in serum and gastric tissues were determined by enzyme-linked immunosorbent assay,and the mRNA expressions of EGFR,NF-κBp65,IkappaBalpha(IκBα)and Zonula Occludens-1(ZO-1)in gastric tissues were determined by real-time reverse transcription polymerase chain reaction,and the efficacy was observed.Then,plasma metabolomic analysis was performed by UPLC-MS/MS to screen the specific potential biomarkers,metabolic pathways and to explore the possible mechani-sms.RESULTS 48 chemical constituents were identified.Many of them have strong pharmacological activity,the results also revealed that A.japonica significantly improved the pathological damage of gastric tissues,increased the expression levels of IL-10,IκBαrelated to anti-inflammatory factors,decreased the expression levels of IL-1β,NF-κB,NF-κBp65,related to proinflammatory factors,restored the levels of factors about EGF,EGFR,ZO-1 associated with ulcer healing and the levels of factors about NKA associated with energy metabolism.Metabolomic analysis identified 10 potential differential metabolites and enriched 7 related metabolic pathways.CONCLUSION These findings contribute to the understanding of the potential mechanism of A.japonica to improve acetic acidinduced GU,and will be of great importance for the development and clinical application of natural drugs related to A.japonica.
文摘<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> It is not well analyzed whether there are differences in plasma levels of tryptophan (TRP) metabolites between healthy control people (HC) and patients of major monopolar depression (MMD). </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Ultra high-speed </span></span><span style="font-family:""><span style="font-family:Verdana;">liquid chromatography/mass spectrometry has been used for the simultaneous determination of plasma levels of tryptophan metabolites in depressive </span><span><span style="font-family:Verdana;">patients. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> There are no significant differences between plasma levels of TRP between HC and MMD. Plasma levels of TRP of HC are higher in young men, young women, old men, and old women in this order. Serotonin (5-HT) levels are higher in MMD than HC. Plasma levels of 5-HIAA of HC are also higher than those of patients of MMD. Plasma levels of kynurenine (KYN) of healthy old men and old women are higher than those of young men and old women. Plasma levels of KYN are higher in old women and young men of MMD than those of HC. </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> Plasma levels of 5-HT are higher in patients of MMD than those of HC, which may suggest that use of drugs inhibiting the 5-HT transportation may increase plasma levels of 5-HT in MMD.
基金supported by the National Natural Science Foundation of China(No.21171132)the Project of Shandong Province Higher Educational Science and Technology Program(J14LC01)Science Foundation of Weifang
文摘A novel Zn(Ⅱ) complex, [ZnL_2(H_2O)_4]·H_2O(1, HL = 2-(nicotinoyloxy)acetic acid), was synthesized using Zn(OAc)_2·2H_2O and 2-(nicotinoyloxy)acetic acid as raw materials. Its structure has been elucidated by elemental analysis, IR and single-crystal X-ray diffraction. The structural analysis revealed that complex 1 crystallizes in triclinic, space group P1 and the Zn(Ⅱ) atom is six-coordinated with two N atoms from two different 2-(nicotinoyloxy)acetate anion ligands and four O atoms from coordinated water molecules. Complex 1 forms a 3D network structure by O–H···O hydrogen bonds. The antitumor activities of 2-(nicotinoyloxy)acetic acid ligand and its Zn(Ⅱ) complex were evaluated against human lung adenocarcinoma A549 cells, human hepatoma SMMC-7721 cells and human colon carcinoma Wi Dr cells.
文摘Objective: To investigate the anti-colitic effects of diet containing seeds of Buchholzia coriacea(B. coriacea) on acetic acid induced ulcerative colitis. Methods: Male Wistar rats(70-100 g) were fed with standard diets(control group) or with same diet containing B. coriacea seeds at 12.5% or 25% for six weeks. At the sixth week, colitis was induced by intra-rectal administration of 1 mL/200 g 6% acetic acid. Animals were sacrificed at days 0(before induction), 1, 3 and 7 post induction to assess disease severity via evaluation of stool consistency, haematological variables and histomorphometry of colon tissues. Results: A significant increase in body weight was observed in the 12.5% B. coriacea fed group compared to the control. B. coriacea significantly reduced stool consistency and microscopic scores. Histological evaluation revealed significantly decreased inflammatory aggregates in B. coriacea fed groups compared to control after colitis induction. There was a significant decrease in packed cell volume, red blood cell and haemoglobin concentration in the control group at day 1 post colitis induction compared to 12.5% B. coriacea fed groups. Neutrophils and white blood cell were also significantly increased after colitis induction in the control group while these were significantly decreased in the B. coriacea fed groups. Conclusions: The addition of B. coriacea seeds to diets promotes healing of acetic acid induced colitis by suppressing infiltration of inflammatory aggregates and ameliorating anemia.
文摘Objective:To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action.Methods:Ethanolic crude extract of Salsola imbricata was characterized by HPLC.Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200μL,7.5%acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays.The levels of malondialdehyde,glutathione peroxidase 1,superoxide dismutase,and catalase were determined in colon tissues.Proinflammatory cytokines including interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were quantified by ELISA.The extent of tissue damage was assessed by histological analysis.Results:Phytochemical analysis confirmed the presence of phytochemicals including quercetin,gallic acid,syringic acid,benzoic acid and chlorogenic acid in the crude extract.The crude extract of Salsola imbricata(300 and 500 mg/kg)markedly decreased malondialdehyde and nitric oxide(P<0.01)and increased antioxidant activities of glutathione peroxidase 1(P<0.001)and superoxide dismutase(P<0.001).Moreover,it decreased the levels of IL-1β,IL-6 and TNF-αsignificantly(P<0.001)and reduced the damage to the colon mucosa,promoting tissue healing and regeneration.Conclusions:Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.
文摘Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained with selectivity of 82.7% and once-through space time yield (STY) of 257.4 g/h(L.
文摘Objective To investigate the effect of naphthalene acetic acid(NAA) on proliferation and apoptosis of mice hepatocytes.Methods Fifty mice were randomly divided into five groups: positive control,normal control,low,middle and high dose of NAA groups.Mice in low,middle and high dose of naphthalene acetic acid groups were fed with 200 mg/kg,1 000 mg/kg and 5 000 mg/kg NAA animal food,respectively.Mice in positive control,normal control groups were fed with usual animal food.After 4 weeks,mice were sacrificed and liver was separated.Three days before scarification,mice in positive control group were given 20 mg/kg ascyclophosphami daily by intraperitoneal injection.The proliferative activity of hepatocytes was detected by MTT assay.The expressions of PCNA protein and Caspase-3 were measured by immunohistochemistry method.Results The proliferative activities of mice hepatocytes in high dose group and normal control group were 0.794±0.019 and 1.055±0.019, respectively.The expressions of PCNA protein and Caspase-3 in high dose group were 11.2% and 37.9%,and those in the normal group were 33.1% and 6.3%, respectively.All differences were significant(P<0.01).Conclusion High dose of NAA acid could significantly inhibit proliferation and increase apoptosis of hepatocytes in mice.
基金supported by Young Key Teachers Training Program of Henan University of Technology and Young Key Teachers Cultivation Plan in Colleges and Universities of Henan province (2019GGJS-088)sponsored by Natural Science Foundation of Henan(202300410113)
文摘Sourdough starters for making traditional steamed bread are rich in microbes.Studies have shown that,in addition to yeast and lactic acid bacteria(LAB),acetic acid bacteria(AAB)are other functional species in sourdough,but the influences of AAB on the properties of sourdough and steamed bread were rarely reported.This study aimed to assess the effects of a selected strain of acetic acid bacterium on the properties of sourdough and steamed bread.Sourdoughs and steamed breads were prepared from five different starter cultures,marked as CK(control check,with no starters),Y(only yeast),YL(yeast+LAB),YA(yeast+AAB)and YLA(yeast+LAB+AAB),and their properties were determined.The results of sour dough properties showed that the YLA sourdough had the highest total titratable acid of 14.6 mL and the lowest pH of 3.87 compared with the other groups after fermentation to 8 h;and the YLA sourdough had the greatest elasticity and viscosity.The results of quality properties of steamed bread revealed that the L*value(88.40±0.09)of the YA steamed bread was significantly higher than those of the YLA and YL steamed breads;the YLA steamed bread had the highest specific volume and the highest sensory score of 89.6±3.31 in comparison to those of the other groups;the hardness and chewiness of YLA and YA steamed breads were significantly lower than those of the other groups.Volatile compounds in the steamed breads were also determined by SPME-GC-MS.A total of 42 flavor substances were detected,including 3 kinds of alcohols,8 kinds of aldehydes,7 kinds of ketones,2 kinds of acids,15 kinds of esters,1 furan,and 6 kinds of other types of compounds,mainly alkanes and esters,followed by alcohols and aldehydes.The YLA steamed bread was richer in esters,aldehydes,and acids than those from the other treatment groups.By contrast,alkanes and aldehydes were dominant in the Y and YL steamed breads.Therefore,the flavor and quality of the steamed bread made from the YLA sourdough could be improved obviously.These results could provide references for the application of AAB in dough fermentation and the improvement of new kinds of starters.
文摘This study was conducted during 2019/2020 on sweet cherry trees (<i>Prunus Avium</i> L.) (Bing and Hardy Giant) cultivar planted at Sergaya-Al_Zabadani area of Rural </span><span style="font-family:"">Dam</span><span style="font-family:"">ascus, to reduce fruit drop of sweet cherry. The experiment included 4 foliar applications: T1: control, T2: GA<sub>3</sub> (100 ppm), T3: NAA (20 <span>ppm), T4: (100 ppm GA<sub>3</sub> + 20 ppm NAA). Fruit set and fruit drop pe</span>rcentage, fruiting factor, and yield were recorded. The results showed that treatment with (100 ppm GA<sub>3</sub> + 20 ppm NAA) recorded higher fruit set percentage (73.81% and 75.62%), and fruiting factor (48.38% and 50.04%) respectively</span><span style="font-family:"">;</span><span style="font-family:""> <span>In addition to fruit yield (40.19 and 41.21 kg/tree) for both cultivars, co</span>mpared to the control (9.13, 6.60 kg/tree). Therefore, it can be concluded that GA<sub>3</sub> + NAA treatment reduced Sweet cherry fruit drop better than other treatments, <span>where fruit drop percentage didn’t exceed (63.11% and 62.01%) in both cu</span>ltivars (Bing and Hardy Giant) respectively, compared to the control (80.92% and 80.64%).
文摘It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative bacteria. In this study, we evaluated the effects of intake of Gluconacetobacter hansenii GK-1 (GK-1), Gram-negative acetic acid bacteria, for 12 weeks on physical condition and immune indices. We conducted a randomized, double-blind, placebo-controlled, parallel-group study in 100 healthy adults. The subjects were randomized into the GK-1 and the placebo groups. The diary-administered physical condition survey was conducted during the study period. The evaluation of salivary sIgA levels, NK-cell activity, and serum IFN-γ levels and quality of life survey was conducted before, in 6 weeks, and 12 weeks after the start of ingestion. Based on the physical condition survey, the cumulative onset-days of symptoms were significantly suppressed in the GK-1 group compared to the placebo group regarding the evaluation of 13 symptoms related to immunity, every 3 weeks. Additionally, salivary sIgA levels per hour were significantly increased in the GK-1 group compared with the placebo group at 6 and 12 weeks. Despite no significant differences in the NK-cell activity, serum IFN-γ levels or quality of life survey between the groups. Serum IFN-γ levels in the GK-1 group were significantly elevated at 12 weeks after the start of ingestion compared with those before ingestion. In conclusion, intake of GK-1 was shown to increase salivary sIgA levels and improve physical condition. This suggested that oral intake of GK-1 may help maintain the immune system.
文摘Fruit vinegar is a new beverage emerging in recent years because of its rich nutrition. At present, acetic acid bacteria are main strains used in the fruit vinegar production. Acetic acid bacteria are a general term for a class of bacteria that can oxidize ethanol to acetic acid. This paper mainly summarized the biological characteristics and research status of acetic acid bacteria for fruit vinegar brewing, in order to provide a theoretical basis for the selection of high-quality acetic acid bacteria for fruit vinegar brewing.
文摘Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate the thermo-ethanol-acid tolerance characters of five AAB strains (VMA1, VMA5, VMA7, VMAM, VMAO) previously isolated from fermented mango alcohol and belonging to Gluconoacetobacter genera. As result, the five AAB strains exhibited good growth and acid production at temperatures up to 45°C;they could tolerate and produce acetic acid at ethanol concentrations up to 20% (v/v). In addition, the studied strains showed growth at acetic acid concentrations up to 4.5% (w/v). Strains VMA7 and VMAO showed the highest resistance properties: they demonstrated acid production at 50°C and VMAO could even grow at 60°C;they tolerated and produced acetic acid at 25% (v/v) ethanol concentration;they showed resistance to acetic acid concentrations up to 6% (w/v). Considering all these properties, the use of these strains would seriously contribute to improving the quality of the vinegar produced and help to reduce the cooling water feeds in vinegar production especially in hot countries in the context of global warming.
文摘From January 1995 to December 2004, 860 rainwater samples were collected in the humid savannah of Lamto. Using the Henry’s law, we determined the content of formic and acetic acids in the air based on their concentrations in rainwater. The annual partial pressure of both formic and acetic acids over the decade is variable. It covers a range of 0.003 (1998) to 0.21 ppbv (1996) and 0.27 (1999) to 0.47 ppbv (1996) for formic and acetic acids respectively. Also, the partial pressure in the dry season is higher than that in the wet season. This difference is related to the enrichment of the organic acid content in the air by the various sources that produce these acids. One of the main sources of increment in organic acid is biomass burning. This biomass burning contributes between 21% and 51% to the formation of the two acids in the humid savannah of Lamto. Ultimately the average annual organic acidity varies from 40% to 60% over the ten years period.
基金by the National Basic Research Program of China(2007CB925101)National Science Foundation of China(20671087).
文摘Submicrometer sized pure cubic phase,Eu^(3+)doped,and Yb^(3+)/Er^(3+)co-dopedα-NaYF4 particles with octahedral morphology have been prepared in acetic acid.The acetate anion plays a critical role in the formation of such symmetric octahedral structures through its selective adsorption on the(111)faces of the products.The size of the as-prepared octahedra can be tuned by varying the amount of sodium acetate added to the acetic acid.A possible formation mechanism for these octahedra has been proposed.The dopedα-NaYF_(4) octahedral submicrometer particles show down-conversion and up-conversion photoluminescence typical of these materials.
基金the National Natural Science Foundation of China(Grant No.31260398)the Hainan Province Natural Science Foundation,P.R.China(Grant No.313044).
文摘Acetic acid is the main component of the volatile acid in the wine.However,excessive amounts of acetic acid negatively affect wine quality.The study aimed to decrease acetic acid content produced by Saccharomyces cerevisiae fermentation after adding metal ion at different temperatures.Response surface methodology(RSM)was used to predict the optimum conditions for acetic acid removal.A central composite design was employed for the experiments and results were analyzed to obtain the best possible combination of fermentation temperature(X1:16℃-24℃)and concentrations of potassium(X2:0-12.0 mM),magnesium(X3:0-8.0 mM),and calcium ions(X4:0-0.2 mM)that would generate the minimum acetic acid in lychee wine at an initial acetic acid concentration of 1.5 g/L.Experimental data were fitted to a second-order polynomial equation using multiple regression analysis and analyzed using analysis of variance(ANOVA).During fermentation under pre-established conditions,the correlation coefficients R2 and Adj-R2 of the models for acetic acid removal were 0.9487 and 0.9007,respectively.After testing,the optimum conditions for acetic acid removal were determined as follows:fermentation temperature of 20℃;potassium,magnesium,and calcium ion concentrations of 10.1 mM,6.1 mM,and 0.2 mM,respectively.The experimental acetic acid content of lychee wine under optimal conditions was found to be 0.309 g/L,which agreed well with the model-predicted value of 0.314 g/L.
