340 research outputs found
Der Ileus - ein Findling in der modernen Medizin?
Zusammenfassung: Kaum einem Krankheitsbild liegt ein so breites differenzialdiagnostisches Spektrum zugrunde wie dem Ileus. Insbesondere die hochgradige Obstruktion und der komplette Ileus können ĂŒber eine bakterielle Translokation und Mikroperfusionsstörungen des dilatierten Darmes zu intestinalen Perforationen und einer KreislaufinstabilitĂ€t fĂŒhren. Klare Algorithmen zur schnellen Kategorisierung des Ileus sind deshalb unabdingbar. Dabei sind insbesondere die Lokalisation des Kalibersprungs beim mechanischen Ileus als auch der Grad der Obstruktion wichtige Kriterien. Die Anamnese, klinische Untersuchung und das konventionelle Röntgenbild des Abdomens sind elementare Bestandteile der Basisdiagnostik. Als Goldstandard der erweiterten bildgebenden Diagnostik hat sich die Computertomographie etabliert. WĂ€hrend fĂŒr die meisten hochgradigen mechanischen Obstruktionen des DĂŒnndarms, die in drei Vierteln der FĂ€lle durch AdhĂ€sionen und Briden bedingt sind, eine explorative Laparotomie indiziert ist, stehen beim obstruierenden Dickdarmileus auch endoskopische Optionen zur VerfĂŒgung. Das Stenting von malignen kolorektalen Tumoren aboral der linken Flexur als ĂŒberbrĂŒckende oder palliative Intervention hat sich ebenso wie die koloskopische Detorquierung des Volvulus etablier
Synthesis and characterization of p-n junction ternary mixed oxides for photocatalytic coprocessing of CO2 and H2O
In the present paper, we report the synthesis and characterization of both binary (Cu2 O, Fe2 O3, and In2 O3 ) and ternary (Cu2 O-Fe2 O3 and Cu2 O-In2 O3 ) transition metal mixed-oxides that may find application as photocatalysts for solar driven CO2 conversion into energy rich species. Two different preparation techniques (High Energy Milling (HEM) and Co-Precipitation (CP)) are compared and materials properties are studied by means of a variety of characterization and analytical techniques UV-Visible Diffuse Reflectance Spectroscopy (UV-VIS DRS), X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Energy Dispersive X-Ray spectrometry (EDX). Appropriate data elaboration methods are used to extract materials bandgap for Cu2 O@Fe2 O3 and Cu2 O@In2 O3 prepared by HEM and CP, and foresee whether the newly prepared semiconductor mixed oxides pairs are useful for application in CO2-H2 O coprocessing. The experimental results show that the synthetic technique influences the photoactivity of the materials that can correctly be foreseen on the basis of bandgap experimentally derived. Of the mixed oxides prepared and described in this work, only Cu2 O@In2 O3 shows positive results in CO2-H2 O photo-co-processing. Preliminary results show that the composition and synthetic methodologies of mixed-oxides, the reactor geometry, the way of dispersing the photocatalyst sample, play a key role in the light driven reaction of CO2 âH2 O. This work is a rare case of full characterization of photo-materials, using UV-Visible DRS, XPS, XRD, TEM, EDX for the surface and bulk analytical characterization. Surface composition may not be the same of the bulk composition and plays a key role in photocatalysts behavior. We show that a full material knowledge is necessary for the correct forecast of their photocatalytic behavior, inferred from experimentally determined bandgaps
The Current Generation of Integrated Engineering Curriculum
In September of 2004 our university adopted the Multidisciplinary Engineering Foundation Spiral Curriculum as the basis for disciplinary engineering programs in Chemical, Civil, Electrical, Mechanical and General Engineering. The curriculum includes a sequence of first and second year engineering courses, matched closely with the development of studentsâ mathematical sophistication and analytical capabilities and integrated with course work in the sciences. Students develop a conceptual understanding of engineering basics in this series of courses which stress practical applications of these principles. The new curriculum was designed to provide students with a multidisciplinary perspective while developing basic engineering skills and fostering an understanding of basic engineering concepts. Each of the ten courses in the program were developed and are taught by faculty from several disciplines. Course materials are intended to make students keenly aware of the highly integrated nature of the current practice of engineering. It was also expected that the novel program would prove to be attractive to a broader range of students than those drawn to traditional disciplinary programs. Finally, student retention was expected to be enhanced by the new courses. Students who entered as freshmen in 2004 are currently juniors, taking courses in their disciplinary major. This study attempts to provide early data on the success of the program through the following measures:
âą Impact of the new curriculum on student recruiting through a survey of newly matriculated students
âą Impact on student retention from first to second and second to third years
âą Comparison of student performance in early disciplinary courses with that of students in previous years
âą Impact of program implementation on faculty attitude
Selective Aerobic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran or 2-Formyl-5-furancarboxylic Acid in Water by using MgOâ CeO2 Mixed Oxides as Catalysts
Mixed oxides based on MgOâ
CeO2 were used as efficient catalysts in the aerobic oxidation of 5-hydroxymethylfurfural (5-HMF) to afford, with very high selectivity, either 2,5-diformylfuran (DFF, 99 %) or 2-formyl-5-furancarboxylic acid (FFCA, 90 %), depending on the reaction conditions. 5-Hydroxymethyl-2-furancarboxylic acid (HMFCA, 57â90 %) was formed only at low concentration of 5-HMF (<0.03 m) or in presence of external bases. The conversion of 5-HMF ranged from a few percent to 99 %, according to the reaction conditions. The oxidation was performed in water, with O2 as oxidant, without any additives. The surface characterization of the catalysts gave important information about their acidâbase properties, which drive the selectivity of the reaction towards DFF. FFCA was formed from DFF at longer reaction times. Catalysts were studied by XPS and XRD before and after catalytic runs to identify the reason why they undergo reversible deactivation. XRD showed that MgO is hydrated to Mg(OH)2, which, even if not leached out, changes the basic properties of the catalyst that becomes less active after some time. Calcination of the recovered catalyst allows recovery of its initial activity. The catalyst is thus recoverable (>99 %) and reusable. The use of mixed oxides allows tuning of the basicity of the catalysts, avoiding the need for external bases for efficient and selective conversion of 5-HMF and waste formation, resulting in an environmentally friendly, sustainable process
OptoâElectronic Characterization of Photocatalysts Based on p,nâJunction Ternary and Quaternary Mixed Oxides Semiconductors (Cu2OâIn2O3 and Cu2OâIn2O3âTiO2)
Semiconductor materials are the basis of electronic devices employed in the communication and media industry. In the present work, we report the synthesis and characterization of mixed metal oxides (MOs) as p,nâjunction photocatalysts, and demonstrate the correlation between the preparation technique and the properties of the materials. Solidâstate UV-visible diffuse reflectance spectroscopy (UVâVIS DRS) allowed for the determination of the light absorption properties and the optical energy gap. Xâray photoelectron spectroscopy (XPS) allowed for the determination of the surface speciation and composition and for the determination of the valence band edge. The optoâelectronic behavior was evaluated measuring the photocurrent generated after absorption of chopped visible light in a 3âelectrode cell. Scanning electron microscopy (SEM) measurements allowed for auxiliary characterization of size and morphology, showing the formation of composites for the ternary Cu2OâIn2O3 p,nâmixed oxide, and even more for the quaternary Cu2OâIn2O3âTiO2 MO. Light absorption spectra and photocurrentâtime curves mainly depend upon the composition of MOs, while the optical energy gap and defective absorption tail are closely related to the preparation methodology, time and thermal treatment. Qualitative electronic band structures of semiconductors are also presented
Transmembrane transporters and salt tolerance in temperate japonica rice
Several investigations aimed at identifying molecular tools useful for the selection and/or the constitution of high-yield salt tolerant rice have been successfully carried out, concerning in particular indica and/ or tropical rice genotypes. Te global warming process is nowadays determining the intrusion of saline wedge into coastal fresh-water streams, and the soil salt concentration of many European rice areas, where temperate rice cultivars are mainly grown, is more and more increasing. In order to identify molecular markers and/or new loci related to salt tolerance, a Genome Wide Association Study (GWAS) has been carried out using a panel of 277 japonica rice accessions. Te panel has been subjected to Genotyping By Sequencing and phenotyping concerning tolerance to a mild-salt stress soil condition (5 dS m-1) expressed at the 4th-5th leaf developmental stage using the Standard Evaluation Score (SES) proposed by IRRI. On the basis of GWAS, a QTL including a few genes that in the indica rice genome are localized within the major salinity tolerance-related QTL \u2018SalTol\u2019 have been identified. Among them, the Os01g0337500 gene encoding the vacuolar H+-pyrophosphatase 6 (OsOVP6) is present. Since the role of the OsOVP6 activity is considered central in regulating the cellular Na+ homeostasis in both roots and leaves, investigations comparing some elements of the complex mechanisms involved in this process have been carried out. A physiological approach evaluating this possibility has been conducted in two japonica rice varieties (Galileo and Virgo) that resulted salt-tolerant, in one japonica rice variety (PL12) known to be quite salt-susceptible, and in the salt-tolerant indica inbred genotype FL478 (containing the \u2018SalTol\u2019 QTL) as reference genotype. Te root and shoot Na+/K+ ratio, Na+ influx and K+ efflux, H+ extrusion activity, cytosolic and vacuolar pH by in vivo 31P-NMR techniques were evaluated in roots of the four rice genotypes. Te results obtained, together with the electrophysiological evaluation of the whole root Na+ conductance, allow to define a picture that may explain the different salt tolerance observed among the rice genotypes analyzed. As a whole, these results confirm the interest towards a deep allele mining analysis, concerning OsOVP6, within the most significant members of the japonica rice accession panel under investigation
Establishment of Innovative Shared Departments to Advance Interdisciplinary Education
More and more universities are pursuing interdisciplinary academic activities that span across department and college boundaries. Administrative structures to facilitate such programs are difficult to establish within traditional university frameworks consisting of disciplinary departments and colleges. Often interdisciplinary programs are housed in a traditional disciplinary department or college, or in a standalone center reporting to a college dean or the provost. The difficulty of these structures is obtaining broad buy-in from faculty across departments and having disciplinary degree programs include interdisciplinary coursework.
To overcome the difficulties described above, an innovative shared department structure that fosters collaborations to advance interdisciplinary education has been deployed at the University of New Haven. Three shared departments have been established over the last two years: (1) a college-wide department to support interdisciplinary coursework in the first two years of engineering programs; (2) a university-wide department to support entrepreneurship and innovation; and (3) a university-wide department to support health sciences.
The shared departments typically have faculty whose tenure home is a traditional disciplinary department. Faculty membership is based on interest and activity level in teaching interdisciplinary courses, participating in interdisciplinary co-curricular activities, and performing interdisciplinary research. A few faculty members may be appointed full-time in a shared department. Like traditional departments, the shared departments have chairs to lead and coordinate activities. Faculty membership can vary from year-to-year depending on their level of activity in the shared department. The shared departments are responsible for approving interdisciplinary courses within their jurisdiction. The chairs of the departments are responsible for reviewing the performance of instructors teaching the interdisciplinary courses, and for providing feedback to disciplinary department chairs on the performance of faculty who are members of the shared department.
To date the shared departments have facilitated the following: (1) an Entrepreneurial Engineering Living-Learning Community (LLC) for freshmen; (2) an Innovation and Entrepreneurship LLC for sophomores; (3) an integrated technical communications program across all engineering and computer science programs; (4) an integrated approach to developing entrepreneurial thinking in students across all engineering and computer science programs; (5) the development and teaching of courses on entrepreneurship; and (6) startup weekends and a business plan competition with students drawn from across the university.
The detailed structure of the two shared departments and the lessons learned in establishing and operating them is described in this paper
Analysis of cadmium root retention for two contrasting rice accessions suggests an important role for oshma2
Two rice accessions, Capataz and Beirao, contrasting for cadmium (Cd) tolerance and root
retention, were exposed to a broad range of Cd concentrations (0.01, 0.1, and 1 M) and analyzed for
their potential capacity to chelate, compartmentalize, and translocate Cd to gain information about
the relative contribution of these processes in determining the different pathways of Cd distribution
along the plants. In Capataz, Cd root retention increased with the external Cd concentration, while
in Beirao it resulted independent of Cd availability and significantly higher than in Capataz at the
lowest Cd concentrations analyzed. Analysis of thiol accumulation in the roots revealed that the
different amounts of these compounds in Capataz and Beirao, as well as the expression levels of
genes involved in phytochelatin biosynthesis and direct Cd sequestration into the vacuoles of the root
cells, were not related to the capacity of the accessions to trap the metal into the roots. Interestingly,
the relative transcript abundance of OsHMA2, a gene controlling root-to-shoot Cd/Zn translocation,
was not influenced by Cd exposure in Capataz and progressively increased in Beirao with the
external Cd concentration, suggesting that activity of the OsHMA2 transporter may differentially
limit root-to-shoot Cd/Zn translocation in Capataz and Beirao
A possible role of the trehalose/trehalose-6-phosphate/SnRK1 system in rice response to salt stress
Among the abiotic stresses exacerbated by climate change, soil salinity is one of the most harmful for crops. Rice (Oryza sativa L.) is a very salt-sensitive cereal, with particular regard to the cultivars belonging to the subspecies japonica. In order to identify genomic traits conferring salt tolerance, a collection of 277 rice accessions (ssp. japonica) has been phenotypized under mild-salinity considering germination kinetic parameters and seedling emergence rate. Genotyping By Sequencing (GBS) followed by a Genome Wide Association Study (GWASs) were carried out. A total of 31.421 SNPs were used for the analysis. Significant genotypic-phenotypic associations were observed and a few Marker-Trait Associations (MTAs) were identified. By alignment with the rice reference genome (Os-Nipponbare-Reference-IRGSP-1.0), some of the genes putatively involved in salt stress were highlighted. Among them, our interest has been focused on OsTPP7 (chromosome 9) and OsTPP10 (chromosome 7), genes that belong to the OsTPP gene family encoding for Trehalose-6-Phosphate Phosphatase (TPP) enzymes catalyzing the dephosphorylation of Trehalose-6-Phosphate (T6P) to Trehalose (Tre). The level of T6P plays a central role in abiotic stress tolerance, acting as a signal in the cascade of events regulating sugar metabolism (sucrose) during seed germination and seedling growth. This activity is mediated by Snf1-Related protein Kinase-1 (SnRK1), a metabolic sensor fundamental in maintaining carbon homeostasis under stress condition. Biochemical and molecular analyses were performed on two rice accessions showing opposite behavior under salt stress (Olcenengo, tolerant, and SR113, sensitive). Results concerning T6P, Tre and sucrose levels in growing embryos, the evaluation of the time course of \u3b1-amylase enzyme (target of the SnRK1 system) activity and of OsTPP10-OsTPP7 gene expression appear to allow us to define a picture coherent with the different effects of salt stress in Olcenengo and SR113. Functional characterization of OsTPP10 gene and its allele mining analysis within the 277 rice accessions are in progress
Preliminary Assessment of and Lessons Learned in PITCH: an Integrated Approach to Developing Technical Communication Skills in Engineers
The Project to Integrate Technical Communication Habits (PITCH) has been implemented across seven engineering and computer science undergraduate programs starting in fall 2012. The overarching goal of PITCH is to develop written, oral and visual communication skills and professional habits in engineering students. PITCH activities begin in the very first semester and are reinforced and extended through all four years of each program. After three years of progressively more extensive development and deployment, a preliminary assessment of student writing over their first three years in programs was performed. In May 2016 the first cohort of students will have completed the entire sequence of PITCH courses, including senior design.
PITCH was designed to include technical memoranda, poster presentations, oral presentations, laboratory reports, proposals, and senior design reports. In addition to text elements, the use of tables and graphics also were addressed. These technical communication products are integrated into specific foundational courses common to several programs, as well as higher-level courses unique to each program. Engineering faculty teaching these courses were progressively trained through workshops conducted over three summers, so in the early years not all instructors teaching these courses had been fully trained. A random sample of students from four programs was selected for the assessment. These students had taken freshman through junior courses with trained instructors, and the assessment was performed based on the PITCH writing assignments they submitted in four courses.
Four faculty members and an external consultant involved in the development and deployment of PITCH performed the assessment. Each writing assignment was evaluated through use of a common rubric to see how well students achieved the overall PITCH learning outcomes. The evaluations were done in a series of collective settings with all five evaluators present and each writing assignment was assessed. Student progress through the four courses spanning the first three years of PITCH is quantified and the results are discussed.
Also discussed are pedagogical and administrative lessons learned during development and implementation of PITCH to date.
PITCH is supported by a grant from the Davis Educational Foundation
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