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High Oxygen Nanocomposite Barrier Films Based on Xylan and Nanocrystalline Cellulose

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Nano-Micro Letters 2010年第4期2卷 235-241页

作者： Amit Saxena Thomas j.Elder jeffrey Kenvin arthur j.ragauskas School of Chemistry and Biochemistry Georgia Institute of Technology USDA-Forest Service Southern Research Station Micromeritics Instrument Corporation

The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan,sorbitol and nanocrystalline cellulose.The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more open structure as compared to xylan-sorbitol films containing sulfonated nanocrystalline cellulose.The average pore diameter,bulk density,porosity and tortuosity factor measurements of control xylan films and nanocomposite xylan films were examined by mercury intrusion porosimetry techniques.Xylan films reinforced with nanocrystalline cellulose were denser and exhibited higher tortuosity factor than the control xylan films.Control xylan films had average pore diameter,bulk density,porosity and tortuosity factor of 0.1730 μm,0.6165 g/ml,53.0161% and 1.258,respectively as compared to xylan films reinforced with 50% nanocrystalline cellulose with average pore diameter of 0.0581 μm,bulk density of 1.1513 g/ml,porosity of 22.8906% and tortuosity factor of 2.005.Oxygen transmission rate tests demonstrated that films prepared with xylan,sorbitol and 5%,10%,25% and 50% sulfonated nanocrystalline cellulose exhibited a significantly reduced oxygen permeability of 1.1387,1.0933,0.8986 and 0.1799 cm^3×μm/m^2×d×k Pa respectively with respect to films prepared solely from xylan and sorbitol with a oxygen permeability of 189.1665 cm^3×μm/m^2×d×k Pa.These properties suggested these nanocomposite films have promising barrier properties.

关键词： Nanocomposites Xylan Nanocrystalline cellulose Oxygen barrier

In Situ Wood Delignification toward Sustainable Applications

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Accounts of Materials Research 2021年第8期2卷 606-620页

作者： jianguo Li Chaoji Chen j.Y.Zhu arthur j.ragauskas Liangbing Hu Department of Materials Science and Engineering University of MarylandCollege ParkMaryland 20742United States Forest Products Laboratory USDA Forest ServiceMadisonWisconsin 53726United States Department of Chemical and Biomolecular Engineering and Department of Chemical and Biomolecular Engineering and Center for Renewable Carbon Department of ForestryWildlifeand FisheriesUniversity of Tennessee Institute of AgricultureUniversity of TennesseeKnoxvilleTennessee 37996United States BioEnergy Science Center&Center for Bioenergy Innovation Biosciences DivisionUniversity of Tennessee-Oak Ridge National Laboratory Joint Institute for Biological ScienceOak Ridge National LaboratoryOak RidgeTennessee 37831United States Center for Materials Innovation University of MarylandCollege ParkMaryland 20742United States

CONSPECTUS:As one of the most abundant and versatile natural materials on Earth,recently wood has attracted tremendous attention from scientists and engineers due to its outstanding advantages,including hierarchically porous microstructure,high mechanical strength,environmental friendliness,renewability,and biodegradability.Wood’s hierarchically porous structure and chemical components(e.g.,cellulose,hemicelluloses,and lignin)enable its mechanical,ionic,optical,and thermal properties to be tuned via physical,chemical,and/or thermal modifications.Among these various approaches,the chemical delignification of bulk wood is the most fascinating,in which the majority of lignin and hemicelluloses is removed while leaving the cellulose intact,maintaining wood’s physical integrity and hierarchical structure.This delignified structure is unique,composed of hollow,aligned channels made up of cellulose microfibrils,and particularly attractive given its origin from a sustainable and renewable resource.As a result,delignified wood has attracted increasing attention for applications that go far beyond traditional wood utilization,such as lightweight yet strong structural materials,energy storage and conversion,environmental remediation,flexible electronics,and bioengineering.This Account reviews recent developments in bulk wood delignification strategies toward the achievement of such advanced wood technologies for sustainable applications,with a focus on the research in our group.Similar to chemical pulping and bleaching,wood delignification involves a series of nucleophilic reactions based on alkaline Na2SO3 or Na2S systems(i.e.,chemical pulping)or electrophilic,radical,and oxidation reactions based on H2O2,ClO2,or NaClO systems(i.e.,chemical bleaching)to deconstruct,fragment,and promote the hydrophilicity of lignin macromolecules,which finally make lignin easier to be removed.We discuss the structure and properties of partially and near-completely delignified wood,with a focus on process-structure−property relationships.The

关键词： removed attractive versatile

华南湿地松EMCC制浆过程中木素结构的变化(英文)

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华南理工大学学报（自然科学版） 2002年第9期30卷 65-70页

作者：詹怀宇蒲云桥 arthur j.ragauskas 江健儿华南理工大学制浆造纸工程国家重点实验室广东广州510640 Institute of Paper Science and Technology Corporate Research Center

以华南湿地松为原料制备卡伯值为 16～ 32的常规硫酸盐浆和深化脱木素的改良硫酸盐 (EMCC)浆 .从木材和纸浆中分离木素 ,利用13C_NMR和31P_NMR技术表征木素样品的结构 ,研究制浆过程中木素结构的变化 .结果表明 ,从木材和纸浆中分离出... 详细信息

以华南湿地松为原料制备卡伯值为 16～ 32的常规硫酸盐浆和深化脱木素的改良硫酸盐 (EMCC)浆 .从木材和纸浆中分离木素 ,利用13C_NMR和31P_NMR技术表征木素样品的结构 ,研究制浆过程中木素结构的变化 .结果表明 ,从木材和纸浆中分离出来的木素结构是不同的 ;制浆方法影响纸浆残余木素的结构特征 ,包括脂肪羟基、酚羟基和羧基含量 ,β_O_4结构和缩合结构含量 .对常规硫酸盐浆和改良硫酸盐浆 ,卡伯值较低的纸浆残余木素脂肪羟基和 β_O_4结构含量较低 ,酚羟基、羧基和缩合结构含量较高 .当卡伯值相同时 ,EMCC木素的脂肪羟基和酚羟基含量较低 ,β_O_4结构和羧基含量较高。

关键词：华南湿地松制浆过程 EMCC 木素结构硫酸盐浆脂肪羟基酚羟基羧基 β-O-4结构

Hydrogenation of Pyrolysis Oil from Loblolly Pine Residue

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Paper And Biomaterials 2020年第1期5卷 1-13页

作者： Ajoy Kanti Mondal Chengrong Qin arthur jragauskas Yonghao Ni Fang Huang College of Material Engineering Fujian Agriculture and Forestry UniversityFuzhouFujian Province350108China Guangxi Key Laboratory of Clean Pulp&Papermaking and Pollution Control NanningGuangxi Zhuang Autonomous Region530004China Department of Forestry Wildlifeand FisheriesCenter for Renewable CarbonUniversity of Tennessee Institute of AgricultureKnoxvilleTennessee37996USA joint Institute for Biological Science Biosciences DivisionOak Ridge National LaboratoryOak RidgeTennessee37831USA Department of Chemical Engineering University of New BrunswickFrederictonE3B 5A3Canada Institute of Fuel Research and Development Bangladesh Council of Scientific and Industrial ResearchDhaka-1205Bangladesh

Loblolly pine residue prepared with and without zeolite ZSM-5 was pyrolyzed at 600℃ and the pyrolysis oil was hydrogenated using formic acid as a hydrogen source, in the presence of a Ru/activated carbon catalyst. As indicated by the pyrolysis yield, addition of the zeolite ZSM-5 increased the yield of light oil but decreased the yield of heavy oil. The pyrolysis oils were analyzed by 13C-,31P-,19F-nuclear magnetic resonance(NMR), and heteronuclear single quantum coherence or heteronuclear single quantum correlation nuclear magnetic resonance(HSQC-NMR), demonstrating that the zeolite ZSM-5 can efficiently induce decarboxylation reactions and decrease the content of aliphatic hydroxyl groups in the heavy oil by 57%.After hydrogenation of the pyrolysis oil, the aromatic carbon content decreased by 78%, with a significant increase in the aliphatic carbon content.

关键词： hydrogenation pyrolysis oil Loblolly pine residue zeolite ZSM-5

Effects of High-Definition Transcranial Direct Current Stimulation on Excitability of Spinal Motoneurons under Ankle Dorsi-Plantarflexion Fatigue Task

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Expediting the transition from replacement medicine to tissue engineering

Yiyong Shengwu Lixue/journal of Medical Biomechanics 2024年第2期39卷 293-298页

作者： Yu C. Zhan j. Shen B. Zhou j. Xu L. Fu W. School of Rehabilitation Science Hangzhou Medical College Hangzhou 310000 China Key Laboratory of Exercise and Health Sciences of Ministry of Education Shanghai University of Sport Shanghai 200438 China Harvard Medical School 02115 MA United States Hebrew Senior Life Hinda and arthur Marcus Institute for Aging Research 02131 MA United States

Objective To investigate the effects of high-definition transcranial direct current stimulation (HD-tDCS) on the modulation of the H-reflex and M-wave during ankle dorsiflexion-plantar flexion fatigue tasks to provide direction for the application of HD-tDCS in mitigating neuromuscular fatigue. Methods Twenty healthy young male participants were recruited and randomly assigned to either the real stimulation or sham stimulation group, with 10 participants in each group. The intervention consisted of a 5-day single-blind HD-tDCS application (duration: 20 min; intensity: 2 mA; target: Cz) . Baseline measurements of the H-reflex and M-wave under resting conditions, M-wave during maximal voluntary isometric contraction (MVIC) of the dorsiflexor muscle, and MVIC torque of the dorsiflexor and plantar flexor muscles were obtained. An ankle dorsiflexion fatigue task was performed to determine the time to achieve fatigue for the task. The same fatigue task was repeated and evaluated one day after the intervention. A repeated-measures two-factor (stimulation condition × pre / post fatigue) analysis of variance (ANOVA) was used to analyze the effects of independent variables on the mechanical properties of the muscles and α-motoneuron conduction characteristics. Results After fatigue, voluntary activation (VA), maximal H-reflex (Hmax ), maximal M-wave (Mmax ), and dorsiflexor and plantar flexor MVIC torques in both groups were significantly reduced compared with pre-fatigue levels (P junction under the ankle dorsi-plantarflexion fatigue task. © 2024 Editorial Department of journal of Shanghai Second Medical University. Al

关键词： corticospinal pathway high-definition transcranial direct current stimulation (HD-tDCS) maximal voluntary isometric contraction (MVIC) muscle fatigue neural impulses α-motoneuron activity

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Regenerative Biomaterials 2016年第2期3卷 111-113页

作者： arthur j.Coury Department of Chemical Engineering Northeastern UniversityBostonMAUSA

In this article,an expansive interpretation of“Tissue Engineering”is proposed which is in congruence with classical and recent published definitions.I further simplify the definition of tissue engineering as:“Exerting systematic control of the body’s cells,matrices and fluids.”As a consequence,many medical therapies not commonly considered tissue engineering are placed in this category because of their effect on the body’s responses.While the progress of tissue engineering strategies is inexorable and generally positive,it has been subject to setbacks as have many important medical therapies.Medical practice is currently undergoing a transition on several fronts(academics,start-up companies,going concerns)from the era of“replacement medicine”where body parts and functions are replaced by mechanical,electrical or chemical therapies to the era of tissue engineering where health is restored by regeneration generation or limitation of the body’s tissues and functions by exploiting our expanding knowledge of the body’s biological processes to produce natural,healthy outcomes.

关键词： tissue engineering medical devices combination products regenerative medicine

An implementation assessment of China's Environmental Information Disclosure Decree

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journal of Environmental Sciences 2010年第10期22卷 1649-1656页

作者： Lei Zhang arthur E j Mol Guizhen He Yonglong Lu School of Environment and Natural Resources Renmin University of China Beijing 100872 China Environmental Policy Group Wageningen University Hollandseweg 1 6706 KN Wageningen The Netherlands State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

China＇s 2007 Open Government Information Regulations is widely considered as a milestone in the country＇s information policy history and is praised as a ＂sunshine program＂. The Environmental Information Disclosure Decree was the first to operationalize these general regulations into a sectorai information disclosure system on environment. This study assessed the implementation of the environmental information disclosure system about six months after the Decree took effect on May 1, 2008. Through reviewing the websites of all 31 provincial Environmental Protection Bureaus and the Ministry of Environmental Protection, conducting an experiment with actual information disclosure request, and through interviews with all provincial Environmental Protection Bureaus, this article concluded that the implementation of the environmental information disclosure system still fails short. Future improvements should focus on further publicity of the regulations and decree to enhance public participation, the establishment of an independent evaluation and supervision system for information disclosure, the exchange of experiences and best practices among provincial Environmental Protection Bureaus, and on strengthening the legal status of environmental information disclosure.

关键词： environmental information disclosure environmental governance

Non-small-bowel lesions encountered during double-balloon enteroscopy performed for obscure gastrointestinal bleeding

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World journal of Gastroenterology 2010年第15期16卷 1885-1889页

作者： Hoi-Poh Tee arthur j Kaffes A W Morrow Gastroenterology and Liver Centre Royal Prince Alfred Hospital

AIM:To report the incidence of non-small-bowel bleeding pathologies encountered during double-balloon enteroscopy (DBE) procedures and to analyse their significance.METHODS: A retrospective study of a prospective DBE database conducted in a tertiary-referral center was conducted. A total of 179 patients with obscure gastrointestinal bleeding (OGIB) referred for DBE from june 2004 to November 2008 were analysed looking for the incidence of non-small-bowel lesions (NSBLs; all and newly diagnosed) encountered during DBE.RESULTS: There were 228 (150 antegrade and 78 retrograde) DBE procedures performed in 179 patients. The mean number of DBE procedures was 1.27 per patient. The mean age (SD) of the patients was 62 ± 16 years old. There were 94 females (52.5%). The positive yield for a bleeding lesion was 65.9%. Of the 179 patients, 44 (24.6%) had NSBLs (19 of them had dual pathology with small-bowel lesions and NSBLs); 27 (15.1%) had lesions not detected by previous endoscopies. The most common type of missed lesions were vascular lesions.CONCLUSION: A significant proportion of patients (24.6%) had lesions within reach of conventional endoscopy. Careful repeat examination with gastroscopy and colonoscopy might be required.

关键词： Bleeding Obscure gastrointestinal bleeding Endoscopy Double-balloon enteroscopy

Gastrointestinal disease in children with autism spectrum disorders:Etiology or consequence?

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World journal of Psychiatry 2021年第9期11卷 605-618页

作者： arthur Krigsman Stephen j Walker Pediatric Gastroenterology Resources of New York and Texas GeorgetownTX 78628United States Institute for Regenerative Medicine Wake Forest Baptist Medical CenterWinston SalemNC 27157United States

Chronic gastrointestinal(GI)symptoms and disorders are common in children with autism spectrum disorder and have been shown to be significantly correlated with the degree of behavioral and cognitive impairment.In this unique population,GI symptoms often arise very early in development,during infancy or toddlerhood,and may be misdiagnosed-or not diagnosed at all–due in part to the challenges associated with recognition of symptoms in a minimally or noncommunicative child.Evidence demonstrating that the gut-brain-axis can communicate gut dysbiosis and systemic immune dysregulation in a bidirectional manner raises the question as to whether an untreated gastrointestinal disorder can directly impact neurodevelopment or,conversely,whether having a neurodevelopmental disorder predisposes a child to chronic GI issues.From the data presented in this mini review,we conclude that the preponderance of available evidence would suggest the former scenario is more strongly supported.

关键词： Autism spectrum disorder Gastrointestinal disease Immune dysregulation Neurodevelopment