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Quantification of changes in zero valent iron morphology using X-ray computed tomography

journal of Environmental Sciences 2013年第11期25卷 2344-2351页

作者： Ping Luo elizabeth H.Bailey Sacha j.Mooney Division of Agricultural and Environmental Sciences School of Biosciences University of Nottingham Sutton Bonington CampusSutton Bonington

Morphological changes within the porous architecture of laboratory scale zero valent iron （ZVI） permeable reactive barriers （PRBs）, after exposure to different groundwater conditions, have been quantified experimentally for different ZVI/sand ratios （10%, 50% and 100%, W/W） with the aim of inferring porosity changes in field barriers. Column studies were conducted to simulate interaction with different water chemistries, a synthetic groundwater, acidic drainage and deionised （DI） water as control. Morphological changes, in terms of pore size and distribution, were measured using X-ray computed tomography （CT）. CT image analysis revealed significant morphological changes in columns treated with different water chemistries. For example, 100% ZVI （W/W） columns had a higher frequency of small pores （0.6 mm） was observed in ZVI grains reacted with typical groundwater, resulting in a porosity of 27%, compared to 32% when exposed to DI water. In comparison, ZVI grains treated with the acidic drainage had higher porosity （44%） and larger average pore size （2.8 mm）. 10% ZVI PRB barrier material had the highest mean porosity （56%） after exposure to any water chemistry whilst 100% ZVI （W/W） columns always had the lowest （34%） with the 50% ZVI （W/W） in between （40%）. These results agree with previously published PRB field data and simultaneously conducted geochemical monitoring and mass balance calculation, indicating that both the geochemical and hydraulic environment of the PRB play an important role in determining barrier lifespan. This study suggests that X-ray CT image analysis is a powerful tool for studying the detailed inter pores between ZVI grains within PRBs.

关键词： porosity change X-ray computer tomography mass balance permeable reactive barrier zero valent iron acidic drainage typical groundwater pore-clogging

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Synthesis and evaluation as CO2 chemisorbent of the Li5(Al1-xFex)O4 solid solution materials:Effect of oxygen addition

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journal of Energy Chemistry 2017年第5期26卷 948-955页

作者： Paulina Olavarría elizabeth Vera Enrique j.Lima Heriberto Pfeiffer Laboratorio de Fisicoquímica y Reactividad de Superficies(LaFReS) Instituto de Investigaciones en MaterialesUniversidad Nacional Autońoma de MexicoCircuito exterior s/nCd.UniversitariaDel.Coyoacan C.P.04510Ciudad de MéxicoMexico

Pentalithium aluminate（β-LiAlO） and the corresponding iron-containing solid solution(Li(AlFe)O)were synthetized by solid-state reaction. All the samples were characterized structural and microstructurally by X-ray diffraction, solid-state nuclear magnetic resonance, scanning electron microscopy, Nadsorption-desorption and temperature-programmed desorption of CO. Results showed that 30 mol% of iron can be incorporated into the β-LiAlOcrystalline structure at aluminum positions. Moreover, iron addition induced morphological and superficial reactivity variations. Li(AlFe)Osamples chemisorbed CObetween 200 and 700 °C, where the superficial chemisorption presented the highest enhancement,in comparison to β-LiAlO. Additionally, Li(AlFe)Osamples sintered at higher temperatures thanβ-LiAlO. Isothermal COchemisorption experiments of β-LiAlOand Li(AlFe)Owere fitted to a first order reaction model, corroborating that iron enhances the COchemisorption, kinetically. When oxygen was added to the gas flow, COchemisorption process was mainly enhanced between 400 and 600 °C for the Li(AlFe)Osample in comparison to β-LiAlO. Hence, Li(AlFe)Osolid solution presented an enhanced COchemisorption process, in the presence and absence of oxygen, in comparison to β-LiAlO.

关键词： Lithium aluminate CO2 chemisorption Solid solution Thermogravimetry

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Adult neural stem cell plasticity

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Neural Regeneration Research 2019年第2期14卷 256-257页

作者： elizabeth j.Sandquist Donald S.Sakaguchi Department of Zoology Weber State University Department of Genetics Development and Cell Biology Iowa State University Neuroscience Program Iowa State University Nanovaccine Institute Iowa State University

Stem cells derived from adult tissues have long been consideredmultipotent, able to differentiate into a limited number of cell typesfound in their tissue of origin. Embryonic stem cells, in contrast,are pluripotent, which may differentiate into almost all cell *** the ability to create induced pluripotent stem cells from somaticcells now available, the properties of multipotent stem cellsare being re-evaluated. If adult cells may be reverted to pluripotentstem cells, can multipotent stem cells also be manipulated towardspluripotency? Advancements in biotechnology now allow for bettermethods to investigate stem cell plasticity, such as the relativeinfluence of external versus intrinsic factors on cell fate. Recentstudies indicate that adult neural stem cells (NSCs) demonstrategreater plasticity under certain conditions, resulting in the derivationof a variety of cell types including muscle, hematopoietic, andepithelial cells. This suggests that NSCs may provide a potentialsource of rare cell types for clinical application as an alternative toembryonic stem cells. Producing rare cell types from NSCs ratherthan embryonic stem cells avoids the ethical issues surrounding theuse of this cell type. Further, NSCs may be an advantageous sourcecompared to induced pluripotent stem cells, which are difficult tocreate, expensive, and time-consuming to

关键词： cells stem cell NSCs types

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Aging gracefully: social engagement joins exercise and enrichment as a key lifestyle factor in resistance to age-related cognitive decline

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Neural Regeneration Research 2019年第1期14卷 39-42页

作者： Tyler j.Dause elizabeth D.Kirby Department of Psychology The Ohio State University Department of Neuroscience The Ohio State University Chronic Brain Injury Program The Ohio State University

Cognitive impairment is a consequence of the normal aging process that effects many species, including humans and rodent models. Decline in hippocampal memory function is especially prominent with age and often reduces quality of life. As the aging population expands, the need for interventional strategies to prevent cognitive decline has become more pressing. Fortunately, several major lifestyle factors have proven effective at combating hippocampal aging, the most well-known of which are environmental enrichment and exercise. While the evidence supporting the beneficial nature of these factors is substantial, a less well-understood factor may also contribute to healthy cognitive aging: social engagement. We review the evidence supporting the role of social engagement in preserving hippocampal function in old age. In elderly humans, high levels of social engagement correlate with better hippocampal function, yet there is a dearth of work to indicate a causative role. Existing rodent literature is also limited but has begun to provide causative evidence and establish candidate mechanisms. Summed together, while many unanswered questions remain, it is clear that social engagement is a viable lifestyle factor for preserving cognitive function in old age. Social integration across the lifespan warrants more investigation and more appreciation when designing living circumstances for the elderly.

关键词： aging age-related cognitive decline social engagement hippocampus cognitive enrichment exercise memory neurogenesis

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Managing Student Protest in Republican China： Yenching and St. john＇s Compared

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Frontiers of History in China 2013年第1期8卷 3-31页

作者： elizabeth j. Perry Department of Government Harvard University Cambridge MA 02138 USA

Although similar in many respects, the two major Christian universities in Republican China adopted markedly different approaches to the common challenge of student nationalism. Case studies of the May Thirtieth Movement at St. john＇s University and the December Ninth Movement at Yenching University illustrate the consequences of these sharply contrasting experiences. Whereas St. john＇s was crippled by May Thirtieth, Yenching escaped December Ninth relatively unscathed. The explanation for the contrast, this paper suggests, lies not in any fundamental disagreement in the mission of the two universities or the philosophies of their famous and forceful presidents. It must be sought instead in the different campus cultures in which the student protests originated, and in the urban micro-environments in which the two universities were located： treaty-port Shanghai and post-imperial Peking.

关键词： student protest nationalism Christian universities higher education

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Increased presence of effector lymphocytes during Helicobacter hepaticus-induced colitis

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World journal of Gastroenterology 2012年第13期18卷 1459-1469页

作者： Sarah j McCaskey elizabeth A Rondini jonathan F Clinthorne Ingeborg M Langohr elizabeth M Gardner jenifer I Fenton Department of Food Science and Human Nutrition College of Osteopathic MedicineMichigan State UniversityEast LansingMI 48824United States Department of Food Science Human Nutrition Michigan State UniversityEast LansingMI 48824United States Department of Pathobiology and Diagnostic Investigation Michigan State UniversityEast Lansing MI 48824United States

AIM： To identify and characterize drosophila mothers against decapentaplegic （SMAD）3-dependent changes in immune cell populations following infection with He- Iicobacter hepaticus （H. hepaticus）. METHODS： SMAD3/ （n = L9） and colitis-resistant SMAD3＋/ （n = 24） mice （8-10 wk of age） were in- fected with/-/, hepaticus and changes in immune cell populations [T lymphocytes, natural killer （NK） cells, T regulatory cells] were measured in the spleen and mesenteric lymph nodes （MsLNs） at 0 d, 3 d, 7 d and 28 d post-infection using flow cytometry. Genotype-dependent changes in T lymphocytes and granzyme B＋ cells were also assessed after 28 d in proximal colon tissue using immunohistochemistry. RESULTS： As previously observed, SMAD3＋, but not SMAD3＋/- mice, developed colitis, peaking at 4 wk post-infection. No significant changes in T cell subsets were observed in the spleen or in the MsLNs between genotypes at any time point. However, CD4＋ and CD8＋/ CD62L＋＋ cells, an effector T lymphocyte population, as well as NK cells （NKp46/DX5＋） were significantly higher in the MsLNs of SMAD3/ mice at 7 d and 28 d post-in- fection. In the colon, a higher number of CD3＋ cells were present in SMAD3＋ compared to SMAD3＋/- mice at base- line, which did not significantly change during infection. However, the number of granzyme B＋ cells, a marker of cytolytic lymphoo/tes, significantly increased in SMAD3＋ mice 28 d post-infection compared to both SMAD3＋/- mice and to baseline values. This was consistent with more severe colitis development in these animals. CONCLUSION： Data suggest that defects in SMAD3 signaling increase susceptibility to H. hepaticus-induced colitis through aberrant activation and/or dysregulation of effector lymphoo/tes.

关键词： Transforming growth factor-j3 Colitis Dro-sophila mothers against decapentaplegic Colon cancer T lymphocytes

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Eggshell and environmental bacteria contribute to the intestinal microbiota of growing chickens

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journal of Animal Science and Biotechnology 2020年第4期11卷 1245-1260页

作者： joel j.Maki elizabeth A.Bobeck Matthew j.Sylte Torey Looft Food Safety and Enteric Pathogens Research Unit National Animal Disease CenterAgricultural Research ServiceUS Department of Agriculture1920 Dayton AveAmesIA 50010USA Interdepartmental Microbiology Graduate Program Iowa State University|AmesIA 50011USA Oak Ridge Institute for Science and Education ARS Research Participation ProgramOak RidgeTN 37830USA Department of Animal Science Iowa State UniversityAmesIA 50011USA.

Background: The initial intestinal microbiota acquired from different sources has profound impacts on animal health and productivity. In modern poultry production practices, the source(s) of the establishing microbes and their overall contribution during development of gastrointestinal tract communities are still unclear. Using fertilized eggs from two independent sources, we assessed the impact of eggshell-and environmental-associated microbial communities on the successional processes and bacterial community structure throughout the intestinal tract of chickens for up to 6 weeks ***: Culturing and sequencing techniques identified a viable, highly diverse population of anaerobic bacteria on the eggshell. The jejunal, ileal, and cecal microbial communities for the egg-only, environment-only, and conventionally raised birds generally displayed similar successional patterns characterized by increasing community richness and evenness over time, with strains of Enterococcus, Romboutsia, and unclassified Lachnospiraceae abundant for all three input groups in both trials. Bacterial community structures differed significantly based on trial and microbiota input with the exception of the egg-exposed and conventional birds in the jejunum at week 1 and the ileum at week 6. Cecal community structures were different based on trial and microbiota input source, and cecal short-chain fatty acid profiles at week 6 highlighted functional differences as ***: We identified distinct intestinal microbial communities and differing cecal short-chain fatty acid profiles between birds exposed to the microbiota associated with either the eggshell or environment, and those of conventionally hatched birds. Our data suggest the eggshell plays an appreciable role in the development of the chicken intestinal microbiota, especially in the jejunum and ileum where the community structure of the eggshellonly birds was similar to the structure of conventionally hatched birds

关键词： 16S rRNA gene Eggshell microbiota Environmental microbiota Hatching Intestinal colonization SCFA Succession

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Gastro-intestinal toxicity of chemotherapeutics in colorectal cancer:The role of inflammation

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World journal of Gastroenterology 2014年第14期20卷 3751-3761页

作者： Chun Seng Lee elizabeth j Ryan Glen A Doherty Centre for Colorectal Disease St. Vincent’s University Hospital School of Medicine and Medical Sciences University College Dublin

Chemotherapy-induced diarrhea(CID)is a common and often severe side effect experienced by colorectal cancer(CRC)patients during their *** chemotherapy regimens evolve to include more efficacious agents,CID is increasingly becoming a major cause of dose limiting toxicity and merits further *** is a key factor behind gastrointestinal(GI)toxicity of *** chemotherapeutic agents activate a diverse range of pro-inflammatory pathways culminating in distinct histopathological changes in the small intestine and colonic *** we review the current understanding of the mechanisms behind GI toxicity and the mucositis associated with systemic treatment of *** into the inflammatory response activated during this process gained from various models of GI toxicity are *** inflammatory processes contributing to the GI toxicity of chemotherapeutic agents are increasingly being recognised as having an important role in the development of anti-tumor immunity,thus conferring added benefit against tumor recurrence and improving patient *** review the basic mechanisms involved in the promotion of immunogenic cell death and its relevance in the treatment of colorectal ***,the impact of CID on patient outcomes and therapeutic strategies to prevent or minimise the effect of GI toxicity and mucositis are discussed.

关键词： Chemotherapy Diarrhea Side-effects Immunogenic cell death Pro-inflammatory cytokines

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TIC-Tox: A preliminary discussion on identifying the forcing agents of DBP-mediated toxicity of disinfected water

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journal of Environmental Sciences 2017年第8期29卷 208-216页

作者： Michael j.Plewa elizabeth D.Wagner Susan D.Richardson Safe Global Water Institute and the Department of Crop Sciences University of Illinois at Urbana-Champaign Department of Chemistry and Biochemistry University of South Carolina

The disinfection of drinking water is a major public health achievement; however, an unintended consequence of disinfection is the generation of disinfection by-products（DBPs）. Many of the identified DBPs exhibit in vitro and in vivo toxicity, generate a diversity of adverse biological effects, and may be hazards to the public health and the *** a few DBPs are regulated by several national and international agencies and it is not clear if these regulated DBPs are the forcing agents that drive the observed toxicity and their associated health effects. In this study, we combine analytical chemical and biological data to resolve the forcing agents associated with mammalian cell cytotoxicity of drinking water samples from three cities. These data suggest that the trihalomethanes（THMs） and haloacetic acids may be a small component of the overall cytotoxicity of the organic material isolated from disinfected drinking water. Chemical classes of nitrogen-containing DBPs, such as the haloacetonitriles and haloacetamides, appear to be the major forcing agents of toxicity in these samples. These findings may have important implications for the design of epidemiological studies that primarily rely on the levels of THMs to define DBP exposure among populations. The TIC-Tox approach constitutes a beginning step in the process of identifying the forcing agents of toxicity in disinfected water.

关键词： DBPs CHO cell cytotoxicity Toxicity Additivity

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Cardiovascular dysfunction following spinal cord injury

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Neural Regeneration Research 2016年第2期11卷 189-194页

作者： elizabeth Partida Eugene Mironets Shaoping Hou Veronica j.Tom Spinal Cord Research Center Department of Neurobiology & Anatomy Drexel University College of Medicine

Both sensorimotor and autonomic dysfunctions often occur after spinal cord injury（SCI）. Particularly, a high thoracic or cervical SCI interrupts supraspinal vasomotor pathways and results in disordered hemodynamics due to deregulated sympathetic outflow. As a result of the reduced sympathetic activity, patients with SCI may experience hypotension, cardiac dysrhythmias, and hypothermia post-injury. In the chronic phase, changes within the CNS and blood vessels lead to orthostatic hypotension and life-threatening autonomic dysreflexia（AD）. AD is characterized by an episodic, massive sympathetic discharge that causes severe hypertension associated with bradycardia. The syndrome is often triggered by unpleasant visceral or sensory stimuli below the injury level. Currently the only treatments are palliative - once a stimulus elicits AD, pharmacological vasodilators are administered to help reduce the spike in arterial blood pressure. However, a more effective means would be to mitigate AD development by attenuating contributing mechanisms, such as the reorganization of intraspinal circuits below the level of injury. A better understanding of the neuropathophysiology underlying cardiovascular dysfunction after SCI is essential to better develop novel therapeutic approaches to restore hemodynamic performance.

关键词： blood pressure heart rate autonomic dysreflexia hypertension bradycardia spinal cord lesion sprouting plasticity bladder distension relay sympathetic activity

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