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method Optimization Study on Isolation of Volatile Compounds by Headspace Solid-Phase microextraction (HS-SPmE) from Custard Apple (Annona squamosaL.) Pulp.

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Journal of Analytical Sciences, methods and Instrumentation 2020年第3期10卷 59-77页

作者： mércia de Sousa Galvão Karen leticia de Santana Juliete Pedreira Nogueira maria Terezinha Santos Leite Neta Narendra Narain Departament of Food Engineering Federal University of Paraiba Jo&atilde o Pessoa Brazil Laboratory of Flavor and Chromatographic Analysis PROCTA Federal University of Sergipe S&atilde o Cristóvã o Brazil

Aroma is an important quality parameter, which can help in delaying degradative processes and hence understanding the volatile compounds that are part of an aroma is extremely important. Thus, the aim of this study was to isolate the volatile compounds present in custard apple (m>Annona squamosam> L.) pulp by solid-phase microextraction (SPmE) technique using 3 different fibers (DVB/CAR/PDmS, PDmS and PDmS/DVB). An experimental design was set up to evaluate the best extraction conditions wherein the variables were extraction temperature (minimum 28°C, maximum 62°C), ionic strength (minimum 0, maximum 30.0%) and sample concentration (min 1, max 99.0%). The separation of volatiles was achieved in chromatographic columns of different polarity (polar and non-polar) while identification of volatile compounds was performed by high resolution gas chromatography system coupled with mass spectrometry. The results obtained using 3 different fibers revealed the isolation of 71 compounds with fiber DVB/CAR/PDmS, while only 30 and 21 compounds were isolated using fibers PDmS/DVB and PDmS, respectively. The major classes of compounds identified were terpenes, esters, alcohols and aldehydes. Optimum conditions for obtaining higher number of volatiles for non-polar column were 45°C for extraction temperature, 15% of sodium chloride and 50% of pulp amount which resulted in isolation of a maximum of 78 peaks.

关键词： Flavor SPmE Response Surface methodology Volatiles Gas Chromatography-mass Spectrometry

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Steviol Glycoside Content Dynamics during the Growth Cycle of Stevia rebaudiana Bert

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American Journal of Plant Sciences 2018年第4期9卷 892-901页

作者： Ana Belen Guerrero leticia San Emeterio Itziar Domeno Ignacio Irigoyen Julio muro Departamento de Produccion Agrícola Universidad Publica de NavarraCampus de ArrosadiaPamplonaSpain Research Institute on Innovation&Sustainable Development in Food Chain(ISFood) Universidad Pública de NavarraCampus de ArrosadiaPamplonaSpain

The sweetener compounds in Stevia, steviol glycosides (SG), are mainly found in the leaves. The SG content depends on the plant’s growth stage and is usually highest just before flowering. In temperate areas, Stevia is a polyannual crop (5 - 7 years) with a vegetative period lasting from April-may until October, during which time the crop can be harvested two or three times. This research focuses on the need for knowledge about Stevia’s response to temperate climates in Southern Europe. Two field assays were established from June to October 2013 at two sites in Navarra (Spain). The biomass and content of the two major SG, stevioside (ST) and rebaudioside A (RA), were measured using High Performance Liquid Chromatography (HPLC) in 66 cloned plants, at different developmental stages. Although the results from the two sites showed different SG leaf content dynamics during the plant growth, the optimum harvest date at both sites coincided with the bud-flowering stage at the beginning of September (around 96 days after planting), when a ST yield of 27 g·m-2 was reached. These results show Stevia’s potential as a commercial crop for stevioside production in northern Spain.

关键词： Stevia rebaudiana Bert. Crop Stevioside Rebaudioside A Photoperiod

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S-adenosyl-methionine decreases ethanol-induced apoptosis in primary hepatocyte cultures by a c-Jun N-terminal kinase activity-independent mechanism

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World Journal of Gastroenterology 2006年第12期12卷 1895-1904页

作者： maria del Pilar Cabrales-Romero Lucrecia márquez-Rosado Samia FatteI-Fazenda Cristina Trejo-Solis Evelia Arce-Popoca leticia Alemán-Lazarini Saúl Villa-Trevineo Department of Cell Biology Centro de Investigacién y Estudios Avanzados IPN Av. IPN No. 2508 México DF México Department of Neuroimmunology Instituto National de Neurologia y Neurocirugia MVS Insurgentes Sur 3877 Col La Fama DF México

AIm： To determine the role of c-Jun N-terminal kinase （JNK） activity in ethanol-induced apoptosis and the modulation of this signaling cascade by S-Adenosylmethionine （Adomet）. mETHODS： Primary hepatocyte cultures were pretreated with 100 IJmol/L SP600125, a selective JNK inhibitor, 1 mL/L DmSO or 4 mmol/L Adomet and then exposed to 100 mmo/L ethanol. Hepatocyte apoptosis was determined by the TUNEL and DNA ladder assays. JNK activity and its inhibition by SP600125 and Adomet were determined by Western blot analysis of c-jun phosphorylation and Bid fragmentation. SP600125 and Adomet effects on the apoptotic signaling pathway were determined by Western blot analysis of cytochrome c release and pro-caspase 3 fragmentation. The Adomet effect on glutathione levels was measured by EIIman＇s method and reactive oxygen species （ROS） generation by cell cytometry. RESULTS： The exposure of hepatocytes to ethanol induced JNK activation, c-jun phosphorylation, Bid fragmentation, cytochrome c release and pro-caspase 3 cleavage; these effects were diminished by SP600125, and caused a significant decrease in ethanol-induced apoptosis （P〈 0.05）. Adomet exerted an antioxidant effect maintaining glutathione levels and decreasing ROS generation, without a significant effect on JNK activity, and prevented cytochrome c release and pro-caspase 3 cleavage.CONCLUSION： The JNK signaling cascade is a key component of the proapoptotic signaling pathway induced by ethanol. JNK activation may be independent from ROS generation, since Adomet which exerted antioxidant properties did not have a significant effect on JNK activity. JNK pathway modulator agents and Adomet may be components of promising therapies for alcoholic liver disease （ALD） treatment.

关键词： Alcoholic liver disease c-Jun N-terminal kinase Apoptosis SP600125 S-Adenosyl methionine Bid Reactive oxygen species

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mG289 in mycoplasma genitaliumEnhances microbial Invasion and Bacterial Persistence in Benign Human Prostate Cells

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Open Journal of Urology 2013年第6期3卷 232-245页

作者： Wasia Rizwani leticia Reyes Jeongsoon Kim Steve Goodison Charles J. Rosser Cancer Research Institute MD Anderson Cancer Center Orlando Orlando USA Department of Infectious Disease & Pathology College of Veterinary Medicine University of Florida Gainesville USA

Introduction: Recent studies suggest that infectious organisms may facilitate initiation and metastasis of many human cancers. One infectious organism of interest is mycoplasma genitalium(mg), a prevalent organism in humans known to cause sexually transmitted infection, as well as urethritis and prostatitis. Previous studies have demonstrated that benign, non-tumorigenic human prostate cells (BPH-1) chronically exposed to m. genitalium led to the malignant transformation of these cells as demonstrated in in vitro and in vivo models. Based on work from our laboratory, we felt this malignant transformation revolved around a specific m. genitalium’s ABC transporter (mG289) with homology to m. hyorhinis’ ABC transporter, p37. In this study, differences in m. genitalium’s ability to infect and induce a unique proteome conducive to tumoral growth were studied with engineered m. genitalium in which the p37 protein was silent. materials and methods: Wild-type m. genitalium (strain 431c, designated as m. genitalium WT) and mG289 deficient m. genitalium mutant (strain 260_3, designated as mg260_3) were used for this study. We studied the infectivity potential between m. genitalium WT and mg260_3 upon exposure to BPH-1 cells. Furthermore, we set out to identify a unique proteome in BPH-1 cells exposed to m. genitalium WT that could explain its ability to induce malignant transformation of benign cells. Validation of selected proteomic targets was carried out by Western blot analysis. Results: Both m. genitalium WT and mg260_3 strains showed somewhat similar growth curve when absorbance at 450nm was matched at day 0. Colony forming units (CFUs) were similar for both strains at the same absorbance. However, the ability to infect BPH-1 cells was greatly reduced in mg260_3 compared to the m. genitalium WT (p microscopy. Proteomic analysis of BPH-1 cells infected with either m. genitalium WT or mg260_3 for 8 hr, 24 hr an

关键词： Cancer ER Stress Proteins Infection mycoplasma genitalium Prostate Proteomics

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Physico-Chemical and microbiological Analysis of Water of the “Presa De Los Patos” in the Desierto De Los Leones National Park, mexico

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Advances in Biological Chemistry 2017年第2期7卷 122-138页

作者： Luis Raúl Gutiérrez-Lucas Luz maría Chávez-Ramírez leticia Arregui Departamento de Ciencias Naturales DCNI Universidad Aut&oacute noma metropolitana Unidad Cuajimalpa M&eacute xico City M&eacute xico Secretarí a de Salud Centro de Salud TI Memetla M&eacute xico City M&eacute xico

The Desierto de los Leones National Park is a place that features recreational activities for residents and visitors to mexico City. The Presa de los Patos (Ducks Dam) is one of the many bodies of water that are present in the park. By means of physico-chemical and microbiological analysis, it was determined that the water of the Presa de los Patos cannot be considered potable. The pH range was between 5.5 - 5.9. The turbidity exceeded the values established in the standards (10.7 - 32.3 Nephelometric Turbidity Units (NTU’s)). Chemical Oxygen Demand (COD) showed that large amounts of oxygen are needed to oxidize organic matter (106 - 450 mg/L). The amount of coliforms and fecal coliforms exceeds the values established by the standards used (total coliforms 98 - 956 Colony Forming Units (CFU’s), fecal coliforms 78 - 807 CFU’s). Five bacterial genera (Escherichia coli, Pseudomona, Klebsiella, Shigella and Salmonella) were isolated and identified. most of the bacteria isolated were resistant to ampicillin (90%), while 25% were resistant to ciprofloxacin. The water consumption of the Presa de los Patos is a great risk for the habitants and visitors of the park.

关键词： Water Physico-Chemical microbiological Antimicrobial Resistance Antibiotics

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Assemblages of Giardia duodenalisIsolates from Dogs by Amplification and Restriction of tpi and β-Giardin Genes and Sequencing of SSU rDNA Gene

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Open Journal of Veterinary medicine 2013年第3期3卷 222-227页

作者： leticia Eligio-Garcia Cortés-Campos Adrian Cano-Estrada Apolinar Jiménez-Cardoso Enedina Laboratorio de Investigación en Parasitología Children Hospital of MéxicoMéxico D.F. México

Giardia duodenalis exhibits seven assemblages (A-G) that are distributed in different hosts. The A and B assemblages are commonly found in humans and several mammals, while C and D assemblages are typically found in dogs. The purpose of this study was to determine the assemblage of Giardia duodenalis present in the stool samples of ten canines using an assay based on PCR amplification, restriction analysis, and sequencing of the small subunit ribosomal DNA (SSU-rDNA), β-giardin, and triosephosphate isomerase (tpi) genes in order to establish the similarities or differences between the assemblage obtained with each gene. The results indicated that all positive isolates belonged to assemblage A, and specifically to the sub-assemblage A-I. A comparison of the SSU-rDNA gene sequence revealed the presence of three subgroups of assemblage A. These findings highlight the importance of canine transmission of Giardia in mexico and its genetic plasticity. They also establish a method for additional and more molecularly extensive epidemiological studies to improve sanitation and hygiene in the most affected areas.

关键词： Giardia duodenalis Genotyping Zoonosis tpi β-Giardin SSU rDNA

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回收生皮废料用于皮革加脂的研究

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北京皮革（中外皮革信息版）（中） 2007年第6期 71-74页

作者： leticia m. Santos[巴西] mariliz Gutterres[巴西] 王睿（译）不详四川大学轻纺与食品学院生物质与皮革工程系 610065

皮革生产需要很多步骤。在这些工序中，准备工段的主要目的是清洁生皮，并且通过化学物理作用使得皮组织适合于后期的鞣制工段。在这些操作中，去除了天然脂肪，其目的是防止不需要的反应以及增加了鞣制的反应位置。天然脂肪的去除有以... 详细信息

皮革生产需要很多步骤。在这些工序中，准备工段的主要目的是清洁生皮，并且通过化学物理作用使得皮组织适合于后期的鞣制工段。在这些操作中，去除了天然脂肪，其目的是防止不需要的反应以及增加了鞣制的反应位置。天然脂肪的去除有以下缺点：纤维易于粘在一起，会造成皮革的僵硬。为了避免这一后果，在鞣制后，还需要增加加脂工序。加脂通过在纤维间加入油层使得皮革变得更加柔软。本研究的目的是定量分析生皮中去除的脂肪，开发应用一种可以回收它们并应用于皮革加脂的方法，同时评价加脂吸收作用。本研究给出了在准备工段中从皮上去除的天然脂肪应用于加脂的方法，所以也是一种将废料转为有价值的资源的方法。该工艺的整合增加了经济效益并且减少了制革行业关注的环境污染。

关键词：皮革脂肪废料加脂

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Selection of Lactic Acid Bacteria Isolated from San Simón da Costa Cheese (PDO) in Order to Develop an Autochthonous Starter Culture

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Advances in microbiology 2015年第11期5卷 748-759页

作者： leticia González Araceli Fernández Cuadrillero José maría Castro Ana Bernardo maría Eugenia Tornadijo Department of Food Hygiene and Technology University of León León Spain Institute of Food Science and Technology (ICTAL) University of León León Spain

Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and in this respect, starter cultures consisting of autochthonous lactic acid bacteria strains are of particular interest. In the present study, we investigated lactic acid bacteria population diversity in San Simón da Costa cheese (PDO, Galicia, Spain) and found a predominance of the genus Lactobacillus, which by the end of ripening accounted for 78% of the strains isolated in Rogosa agar, around 40% of those in m17 agar and about 10% of those in mSE agar. The main species of lactic acid bacteria identified were Lactococcus lactis subsp. lactis, Lactobacillus casei subsp. casei, Lb. paracasei subsp. paracasei, Leuconostoc mesenteroides and Enterococcus faecalis. Virtually all the strains studied from a technological point of view yielded more than or equal to 0.24 g 100 mL-1 lactic acid. Lactococcus lactis subsp. lactis (SS 194), Lactobacillus paracasei (SS 1695 and SS 1689) and Enterococcus faecalis (SS 1378 and SS 1449) strains exhibited the greatest proteolytic capacity. Based on the overall technological aptitude of the tested strains, we can propose starter cultures and co-cultures that include different combinations of previous strains with a view to manufacturing San Simón da Costa cheese from pasteurised milk.

关键词： Cow milk Cheese Lactic Acid Bacteria Enzymatic Activities Autochthonous Starter

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Sound Insulation of Floors： A New Composite with a Resilient Layer of Recycled Polymer

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Journal of Civil Engineering and Architecture 2016年第8期10卷 861-869页

作者： Aline Zini leticia K. Zuchetto maria Femanda de O. Nunes Ana m. C. Grisa Daniel T. Pagnussat mara Zeni Laboratory of materials Chemistry Research University of Caxias do Sul Caxias do Sul RS 95070-560 Brazil Institute of Technology for Civil Construction University of Vale do Rio dos Sinos Sao Leopoldo RS 93022-750 Brazil Laboratory of Constructive Technology University of Caxias do Sul Caxias do Sul RS 95010-550 Brasil

PU （polyurethane） integral skin and PVC （polyvinyl chloride） are polymeric materials which have favorable physical characteristics to reduce the impact noise when applied to floor systems. In civil construction, floating floors systems are composed of two layers above the slab： a resilient layer and, above this, a rigid layer of cement matrix that works as a subfloor. This research aims to evaluate the incorporation of PVC and PU skin waste in the resilient layer of the floating floor, for impact noise insulation. It was conducted physical, mechanical and morphological tests in the composite, as SEm （scanning electron microscopy）, determination of compressive creep, and impact noise test to evaluate the absorption capacity of the floor system over time. Furthermore, experimental results were compared with theoretical studies. These correlations may assist in understanding the behavior of impact noise damping and its relation to the size of the samples.

关键词： Floor system impact noise insulation recycled polymer.

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Influence of Inorganic Salts during the Photooxidative Process of Nitrobenzene

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Journal of Environmental Science and Engineering(A) 2013年第4期2卷 267-275页

作者： Fernando Hernandez Aldana Antonio Rivera miguel Angel Hernandez Eduardo Torres Tonahtiuh Rendon Teresa Zayas leticia Flores Chemical Center-Environmental Chemistry BUAP Puebla 72570 Mexico Research Center for microbial Sciences BUAP Puebla 72570 Mexico Zeolites Research Department BUAP Puebla 72570 Mexico Faculty of Chemical Engineering BUAP Puebla 72570 Mexico

Into the photooxidation process, several factors such as pH, time of irradiation, dose of UV light, lamp power, contaminant concentration, turbidity of the solution and the presence of salts can interfere with the photodegradation of pollutants. This research aims to evaluate the influence of salts： NaCl, mgCl2, CaCI2, BaC12, CuCl2, Na2SO4, mgSO4, mnSO4, FeSO4, CuSO4, Na3PO4, K2CrO4 and K2Cr207 in concentrations of 0.0005 m, 0.005 m and 0.05 m during photodegradation of aqueous solution of 59.5 mg/L of nitrobenzene at a pH of 2.5. It was observed that the presence of salts such as CuCI2, CuSO4, FeSO4, K2CrO4 and K2Cr207 interfere negatively in the system UV/H202 applied for degradation of nitrobenzene; possibly by oxidation of Fe2＋ to Fe3＋ and Cu＋ to Cu2＋ in the Cr case, due to the difficulty of transforming the Cr6＋ to Cr3＋ or because these solutions have color and act as radiation absorbing filter.

关键词： AOPs nitrobenzene photooxidation influence by salts.

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