检索结果-南通市图书馆

Sustainability of microporous polymers and their applications

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2017年第8期60卷 1033-1055页

作者： Tamara L.Church alma Berenice Jasso-Salcedo Fredrik Bjrnerbck Niklas Hedin Department of Materials and Environmental Chemistry Stockholm University SE-106 91 Stockholm Sweden

Microporous polymers(MPs) are studied for their intriguing chemistry and physics as well as their potential application in catalytic transformations, gas-separation processes, water purification and so on. Here, we critically review MPs with respect to the sustainability aspects of their synthesis as well as their applications that have sustainable character. Some MPs have been synthesized from monomers derived from biomass resources, but there is certainly a large potential for further *** are also opportunities to improve the sustainability of MP synthesis in terms of the use of solvents, catalysts, and related aspects. The applications of MPs in processes related to sustainability depend upon multiple properties. A rich and flexible chemistry is important to applications as catalysts for, among other useful reactions, the photoreduction of CO_2 and selective oxidation. The(ultra)micropore volume of MPs are crucial in gas-separation applications such as CO_2 capture, and the chemisorption of CO_2 on MP-tethered alkylamines could offer a means to remove that gas from dilute mixtures. When it comes to the storage of H_2 and CH_4 in MPs for onboard use in fuel cell or biogas cars, volumetric capacity is paramount, meaning that the density of the MPs must be considered. Finally, for use in separation and purifications from liquid mixtures(aqueous or hydrocarbon-based), crosslinked MPs are more limited than the solution-processable MPs that can be more easily processed into films and membranes.

关键词： microporous polymers biomass sustainability CO2 capture catalysis H2 storage CH4 storage separation purification

Testicular angioleiomyoma presenting wit laematospermia

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2013年第4期15卷 573-574页

作者： Goran Stimac alma Demirovic Bozo Kruslin Davor Tomas Clinical Department of Urology 'Sestre milosrdnice' University Hospital Center Zagreb 10000 Croatia Ljudevit Jurak' Department of Pathology 'Sestre milosrdnice' University Hospital Center Zagreb 10 000 Croatia and School of Medicine University of Zagreb Zagreb 10 000 Croatia

Dear editors, We report an exceedingly rare case of primary testicular angioleio- myoma to increase awareness of this rare entity among urologists and pathologists. To our knowledge, only one case of this rare testicular tumour has been reported in the literature to date, and this is the first report of its presentation with haematospermia.1 A 65-year-old patient was admitted to our clinic for the evaluation of painless haematospermia. The patient＇s past medical history was unremarkable. At presentation and during the scrotal and testis exam- ination, there was no palpable mass. The patient had no voiding symptoms, and there were no signs of infection. The patient also denied experiencing any recent trauma. A digital rectal examination of the prostate was normal. The ultrasonographic findings disclosed a well-circumscribed ovoid hypoechoic nodule within the right testis, near its upper pole, measuring approximately 0.5 cm, and moderate hydrocele （Figure la）. The values of serum prostate-specific antigen, alpha-fetoprotein, beta-human chorionic gonadotropin and lactate dehydrogenase were normal.

关键词： angioleiomyoma presenting haematospermia

Characterization of Evolutionarily ConservedMotifs Involved in Activity and Regulation of theABA-INSENSITIVE （ABI） 4 Transcription Factor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2014年第2期7卷 422-436页

作者： Josefat Gregorio alma Fabiola Hernández-Bernal Elizabeth Cordoba Patricia León Departamento de Biología Molecular de Plantas Instituto de Biotecnología Universidad Nacional Autónoma de México Av. Universidad # 2001 Col. Chamilpa Cuernavaca Morelos C.p. 62210 Mexico

In recent years, the transcription factor ABI4 has emerged as an important node of integration for externaland internal signals such as nutrient status and hormone signaling that modulates critical transitions during the growthand development of plants. For this reason, understanding the mechanism of action and regulation of this protein rep-resents an important step towards the elucidation of crosstalk mechanisms in plants. However, this understanding hasbeen hindered due to the negligible levels of this protein as a result of multiple posttranscriptional regulations. To betterunderstand the function and regulation of the ABI4 protein in this work, we performed a functional analysis of severalevolutionarily conserved motifs. Based on these conserved motifs, we identified ortholog genes of ABI4 in differentplant species. The functionality of the putative ortholog from Theobroma cacao was demonstrated in transient expres-sion assays and in complementation studies in plants. The function of the highly conserved motifs was analyzed aftertheir deletion or mutagenesis in the Arabidopsis ABI4 sequence using mesophyll protoplasts. This approach permitted usto immunologically detect the ABI4 protein and identify some of the mechanisms involved in its regulation. We identi-fied sequences required for the nuclear localization （AP2-associated motif） as well as those for transcriptional activationfunction （LRP motif）. Moreover, this approach showed that the protein stability of this transcription factor is controlledthrough protein degradation and subcellular localization and involves the AP2-associated and the PEST motifs. We dem-onstrated that the degradation of ABI4 protein through the PEST motif is mediated by the 26S proteasome in responseto changes in the sugar levels.

关键词： ABI4 posttranslational regulation transcription factor sugar signaling abscisic acid-insensitive protea-some nuclear localization signals

Characterization by Thermogravimetric Analysis of Polymeric Concrete with High Density Polyethylene Mechanically Recycled

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Minerals and Materials Characterization and Engineering 2014年第4期2卷 259-263页

作者： alma delia rodriguez Martinez Martha Lilia Dominguez Patino Rosa Maria Melgoza Aleman Gerardo Antonio Rosas Trejo Graduate Engineering and Applied Science Autonomus University of the State of MorelosChamilpaMorelosMexico Faculty of Chemical Sciences and Engineering Autonomus University of the State of MorelosChamilpaMorelosMexico Metallurgical Research Institute University Michoacana de San Nicolas de HidalgoMoreliaMichoacanMexico

This paper presents the results of the characterization by thermogravimetric analysis of a new composite material called polymeric concrete. The polymeric concrete contains micro-particles obtained from High Density Poly-Ethylene (HDPE) mechanically recycled (post-consumer bottles);the official Mexican standard NMX-E-232-SCFI-1999 considers the HDPE as the recyclable plastic material. Thermo-grams based on weight lost were obtained from the raw material (HDPE) and the polymer concrete in order to obtain the glass transition temperature (Tg) and melting temperature (Tf). The analysis conditions were defined from 20°C to 180°C and the heat rate of 1°C/minute. The results show that the glass transition temperature of polymeric concrete is 46°C and the HDPE is 38°C. These results mean that the polymeric concrete is more resistant to decomposition. With respect to the melting temperature, the results show that the 2°C difference between polymeric concrete and HDPE is not significant. The polymeric concrete with HDPE recycled can be considered as composite material thermoplastic. The new material melts when it is heated to 146°C and has the ability to be softened, processed and reprocessed with temperature and pressure changes, which make it possible to obtain molded pieces in the desired shape.

关键词： Polymer Concrete High Density Poly-Ethylene Thermogravimetric Analysis

Effect of <i>Carica papaya</i>Leaf Extract on Serum Lipids and Liver Metabolic Parameters of Rats Fed a High Cholesterol Diet

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2015年第9期7卷 1196-1205页

作者： alma M. Zetina-Esquivel Carlos A. Tovilla-Zárate Crystell Guzmán-Garcia Arturo rodríguez-Hernández Andrés E. Castell-rodríguez Jorge L. Ble-Castillo Angela Avila-Fernandez Isela E. Juárez-Rojop Juan C. Díaz-Zagoya Centro de Investigación División Académica de Ciencias de la Salud Universidad Juárez Autónoma de Tabasco Villahermosa México División Académica Multidisciplinaria de Comalcalco Universidad Juárez Autónoma de Tabasco Comalcalco México Unidad de Medicina Familiar 10 Instituto Mexicano del Seguro Social Xalapa México División de Investigación Facultad de Medicina Universidad Nacional Autónoma de México México D. F. México

Hyperlipidemia plays an important role in the development of atherosclerosis, the main cause of death in the world. In this study, the lipid-lowering effect of Carica papaya leaf in rats fed with a high cholesterol diet was evaluated. Daily doses of C. papaya extract 0, 31, 62 or 125 mg/kg body weight were orally administered in 300 μl polyethylene glycol to hypercholesterolemic rats;it was also administered 62 mg/kg body weight of the extract to rats with normal diet. After a 20-day treatment, the animals were sacrificed;blood and liver were analyzed. Hypercholesterolemic rats showed an increased serum and liver cholesterol, triacylglycerols, and atherogenic index. The C. papaya extract produced a significant decrease of serum and liver cholesterol concentrations in hypercholesterolemic rats, but did not modify serum or liver triacylglycerols;however, the extract reduced the atherogenic index in a dose-dependent manner. C. papaya treatment decreased LDL-C and increased HDL-C in serum significantly. When the oxygen consumption was evaluated in phosphorylating and resting states, the respiratory control in hypercholesterolemic rats mitochondria was lower than in normal diet rats. However, a higher respiratory control in hypercholesterolemic rats mitochondria was observed after C papaya treatment. The liver morphological data are in accordance with serum and liver biochemical values. Our data support that C. papaya has a significant hypocholesterolemic action and HDL-C raising effect on rats fed with a cholesterol-rich diet, however, the precise metabolites responsible of this effect remain unknown.

关键词： Serum Lipids Carica papaya Cholesterol Mitochondria

Experimental hybridization and reproductive isolation between two sympatric species of tephritid fruit flies in the Anastrepha fraterculus species group

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2018年第6期25卷 1045-1055页

作者： Juan Rull Eduardo Tadeo rodrigo Lasa Christian L.rodriguez alma Altuzar-Molina Martin Aluja PROIMI Biotecnologia-OONICET LIEMEN-Division Control Biologico de PlagasTucumanArgentina Red de Manejo Biorracional de Plagas y Vectores Instituto de EcologiaA.C.XalapaVeracruzMexico

Among tephritid fruit flies,hybridization has been found to produce local adaptation and speciation,and in the case of pest species,induce behavioral and ecological alterations that can adversely impact efficient pest *** species group within Anastrepha (Diptera:Tephritidae),is a rapidly radiating aggregate,which includes cryptic species complexes,numerous sister species,and several pest species. Molecular studies have highlighted the possibility of introgression between *** and *** isolation has been studied among morphotypes of the A. fraterculus species complex as a tool for species *** we examined the exis- tence and strength of prezygotic and postzygotic isolation between sympatric populations of two closely related species within the highly derivedfraterculus group (*** and ***),coexisting in *** adults of both species showed a strong tendency for assortative mating,a small proportion of hybrid pairings in both directions were *** also observed asymmetric postzygotic isolation,with one hybrid cross displaying a strong reduction in fecundity and F1 egg *** was greater for the progeny of homotypic and hybrid crosses in the maternal *** was a marked female biased sex ratio distortion for both F1 hybrid *** between *** and *** in nature may be difficult but possible;these two species display stronger reproductive isolation than all pairs of species previously examined in the *** species *** postzygotie isolation is suggestive of Wolbachia mediated cytoplasmic incompatibilities that may be exploited in area-wide pest management.

关键词： Anastrephafraterculus Anastrepha obliqua Haldane's rule introgression prezygotic isolation postzygotic isolation

Polycondensation reaction and its mechanism during lignocellulosic liquefaction by an acid catalyst: a review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forestry Studies in China 2011年第1期13卷 71-79页

作者： NIU Min ZHAO Guang-jie Mehmet Hakki alma College of Materials Science and Technology Beijing Forestry University Beijing 100083 R R. China Faculty of Forestry Kahramanmaras Sutcu Imam University Kahramanmaras 46100 Turkey

The increase in the residue content resulting from polycondensation would be adverse to the utilization of lignocellulose and to the quality of products obtained from liquefied lignocellulosic *** yield of the residue formed from liquefaction and the mechanism of polycondensation were reported mainly by Lin,Yamada and *** major products of cellulosic liquefaction are levulinic acid and hydroxymethylfurfural（HMF） derivatives under polyhydric alcohols and phenolated compounds under *** cleavage of the β-O-4 bonds is the major reaction pathway of lignin liquefaction under various liquefying reagents regardless of whether they contain acid catalysts or *** break up compounds by decomposition are polymerized to substances with high molecular weight by polycondensation in lignocellulosic *** molecular weight of condensed residues increases almost linearly as a function of liquefaction time at the later stage of lignocellulosic *** longer the time required,the greater the content of new residue generated by polycondensation during the entire process of *** conclude that the condensed residues may stem from the interaction of degraded lignin and cellulose components in wood or from the products of two major components reacting with liquefying reagents.

关键词： lignocellulose polycondensation mechanism decomposition condensed residues

Species Account of Anura ns from the Western Slope of Mt. Kita nglad, Mindanao Island, Philippines

在线全文

学校读者我要写书评

暂无评论

Asian Herpetological Research 2021年第1期12卷 76-87页

作者： Elsa May Delima BARON Mark Oliver D.MARIN Benjo A.LOGRAMONTE alma B.MOHAGAN Biology Natural Sciencesand Math Division.Arts and Sciences DepartmentSan Pedro CollegeDavao City 8000MindanaoPhilippines Biology Department College of Arts and SciencesCentral Mindanao UniversityMusuanBukidnon 8714MindanaoPhilipines

The Mt. Kitanglad Range is one of the country’s important key biodiversity sites;however, information about anuran diversity in this protected area remains depauperate. Herein we provided accounts of anuran species from high-elevation forests, in three sites of the western slope of Mt. Kitanglad range. The combined belt-transect sampling and microha bitat searches accounted for 13 species representing five families. The most represented family was Rhacophoridae with five representative species of the genus Philautus. Twelve out of the 13 species documented in the current survey are endemic. Four previously unaccounted species(Pelophr yne brevipes, Pulchrana grandocula, Sanguirana mearnsi, and Philautus surrufus) were added and brought the total anurans known from Mt. Kitanglad to 26 species. Most of the species were also recorded in forested sites, suggestive of their lesser affinity to non-forested ecosystems. The additional species detected during our survey may also imply that full understanding of anuran diversity of Mt. Kitanglad remains far from complete.

关键词： key biodiversity area Mindanao faunal region Philippine endemic anurans upper elevation forests wildlife inventory in Mindanao

与供应商在社会责任方面合作对食品供应链绩效的影响

在线全文

学校读者我要写书评

暂无评论

与供应商在社会责任方面合作对食品供应链绩效的影响

作者：任小琳（alma delia Sánchez Ramírez）清华大学

学位级别：硕士

供应商在保证食品质量、安全可靠和可追踪来源的原料中发挥着关键的作用。然而,由于自然资源缺乏且受到污染,以及气候变化和公众对此产业关注的施压,供应商的职责已延伸至环境与社会问题方面。本文研究的目的在于,通过探索世界上最大的... 详细信息

供应商在保证食品质量、安全可靠和可追踪来源的原料中发挥着关键的作用。然而,由于自然资源缺乏且受到污染,以及气候变化和公众对此产业关注的施压,供应商的职责已延伸至环境与社会问题方面。本文研究的目的在于,通过探索世界上最大的公共食品加工公司的实践,分析供应商在食品供应链中受到环境保护合作和社会协作的影响。为了评价供应商协作的作用,本文研究分析了2012-2014年间64篇关于食品加工公司的可持续发展报告以及78篇关于食品供应链表现的报道。在收集所有数据后,使用最小二乘法(OLS)估计方法来进行假设检验。主要研究成果表明,环保实践以及供应商间的合作能够帮助减少食品产业中的资金周转周期并增加毛利润。另外,为评估供应商的环保与社会协作实践而进行的审计和控制活动有助于提高食品产业链的经营效绩。尽管此文章受限于公司发表信息的有效性,但它能够填补研究领域中供应商在环保和社会责任协作方面的空缺。这对食品供应链中的管理者们有重大指导意义。

关键词：食品产业供应商协作环境保护合作社会协作供应链的性能表现