372 research outputs found
Photoelectrochemical and theoretical investigations of spinel type ferrites (MxFe3-xO4) for water splitting: A mini-review
Solar-assisted water splitting using photoelectrochemical cells (PECs) is one of the promising pathways for the production of hydrogen for renewable energy storage. The nature of the semiconductor material is the primary factor that controls the overall energy conversion efficiency. Finding semiconductor materials with appropriate semiconducting properties (stability, efficient charge separation and transport, abundant, visible light absorption) is still a challenge for developing materials for solar water splitting. Owing to the suitable bandgap for visible light harvesting and the abundance of iron-based oxide semiconductors, they are promising candidates for PECs and have received much research attention. Spinel ferrites are subclasses of iron oxides derived from the classical magnetite (FeIIFe2 IIIO4) in which the FeII is replaced by one (some cases two) additional divalent metals. They are generally denoted as MxFe3-xO4 (M=Ca, Mg, Zn, Co, Ni, Mn, and so on) and mostly crystallize in spinel or inverse spinel structures. In this mini review, we present the current state of research in spinel ferrites as photoelectrode materials for PECs application. Strategies to improve energy conversion efficiency (nanostructuring, surface modification, and heterostructuring) will be presented. Furthermore, theoretical findings related to the electronic structure, bandgap, and magnetic properties will be presented and compared with experimental results
High-throughput screening of caterpillars as a platform to study host-microbe interactions and enteric immunity.
Mammalian models of human disease are expensive and subject to ethical restrictions. Here, we present an independent platform for high-throughput screening, using larvae of the tobacco hornworm Manduca sexta, combining diagnostic imaging modalities for a comprehensive characterization of aberrant phenotypes. For validation, we use bacterial/chemical-induced gut inflammation to generate a colitis-like phenotype and identify significant alterations in morphology, tissue properties, and intermediary metabolism, which aggravate with disease progression and can be rescued by antimicrobial treatment. In independent experiments, activation of the highly conserved NADPH oxidase DUOX, a key mediator of gut inflammation, leads to similar, dose-dependent alterations, which can be attenuated by pharmacological interventions. Furthermore, the developed platform could differentiate pathogens from mutualistic gastrointestinal bacteria broadening the scope of applications also to microbiomics and host-pathogen interactions. Overall, larvae-based screening can complement mammals in preclinical studies to explore innate immunity and host-pathogen interactions, thus representing a substantial contribution to improve mammalian welfare
Lehren und Lernen aus Sicht von SchĆ¼lerinnen und SchĆ¼lern im Politik-Unterricht der Gymnasialen Oberstufe. Ein Beitrag zur lernerorientierten, fachdidaktischen und qualitativen Unterrichtsforschung.
In dieser Untersuchung, die in unmittelbarer NƤhe zum Unterrichts- und Lerngeschehen eines Grundkurses der Oberstufe durchgefĆ¼hrt wurde, werden die individuellen Lernprozesse der SchĆ¼lerInnen zum Gegenstand gemacht und neue Erkenntnisse Ć¼ber das Lernen im Politikunterricht und den damit verbundenen Wahrnehmungsmuster erlangt.
Lernen ist ein hƶchst individueller Vorgang. Aus diesem Grund mĆ¼ssen Untersuchungen, die das Lernverhalten der SchĆ¼lerInnen zum Gegenstand haben, mƶglichst nahe am Lern- und Unterrichtsgeschehen platziert sein und die SchĆ¼ler selbst so oft und so direkt wie mƶglich zu Wort kommen lassen. Dies hat Auswirkung auf die Wahl der Erhebungsinstrumente der vorliegenden Studie und bedingt deren vorwiegend qualitative Ausrichtung.
Lernen ist darĆ¼ber hinaus auch ein hƶchst komplexer Vorgang, was die Erweiterung einer rein fachdidaktischen Fragestellung und ihre VerknĆ¼pfung mit einer allgemeindidaktischen Fragestellung sinnvoll macht.
Diese ZusammenhƤnge werden im ersten Teil der Arbeit in Gestalt der Aufarbeitung der entsprechenden allgemein- und fachdidaktischen Diskussion und der nƶtigen lernpsychologischen Grundlegung entwickelt.
Im Zentrum des zweiten Teils steht die empirische Studie selbst.
In dritten Teil der Studie werden die gewonnenen Erkenntnisse auf ihre politikdidaktischen und unterrichtspraktischen Konsequenzen hinterfragt. VorschlƤge zu einem ĀverbessertenĀ Politikunterricht schlieĆen sich an.
Dem FĆ¼hren eines Lerntagebuchs kommt in der Untersuchung eine besondere Bedeutung zu. Das Lerntagebuch bietet eine Schnittstelle als didaktisches Mittel und als Erhebungsinstrument.
Als didaktisches Mittel kann es zu Dokumentation und Evaluation des Unterrichts- und Lerngeschehens verwendet werden. Hier hat es vor allem auch eine Bedeutung fĆ¼r Lehrer zur Evaluation des eigenen Unterrichts und kann in der Hand des SchĆ¼lers neben der Evaluation des eigenen Lernprozesses auch ein Medium oder eine Methode zur VerƤnderung des Lern-verhaltens sein.
Als Datenquelle dient es der Rekonstruktion des Lernverhaltens, und kann im Sinn eines Diagnoseinstrumentes zu Aussagen Ć¼ber den Grad der Entwicklung von Lernkompetenz her-angezogen werden. Als Erhebungsinstrument verfĆ¼gt das LB Ć¼ber folgende Besonderhei-ten:
es wird ausschlieĆlich von den betroffenen Subjekten selbst und direkt erstellt,
es befindet sich in zeitlicher NƤhe zum Unterrichtsgeschehen,
es hat das Unterrichtsgeschehen selbst und das Lernen zum Gegenstand,
es lƤsst durch die relativ offene Form freie ĆuĆerungen zu,
und kann zugleich auch fĆ¼r die Dauer der Untersuchung einen prozessualen Aspekt erfassen.
Ergebnisse der Lerntagebucheinsatzes:
Die Wirksamkeit des Lerntagebuchs als methodisches Mittel zur VerƤnderung des Lern-verhaltens und zur Steigerung der Lernkompetenz ist in hohem MaĆe mit der Struktur des Unterrichts und den damit verbundenen Lernarrangements verknĆ¼pft.
Das Lerntagebuch ist keine fĆ¼r sich unabhƤngige, beliebig einzusetzende Methode, sondern komplementƤr zum Unterrichtsarrangement zu betrachten und in dieser KomplementaritƤt genau an diesen anzupassen . Die Wirksamkeit des Lerntagebuch setzt die VerƤnderung des traditionellen unterrichtlichen Settings im Sinne von mehr offenem und selbstbestimmten Lernen voraus.
In der Studie konnte gezeigt werden,
dass das FĆ¼hren des Lerntagebuchs zu einer VerƤnderung des Lernverhaltens gefĆ¼hrt hat: Die SchĆ¼ler setzten sich durch das LerntagebuchfĆ¼hren bedingt intensiver mit den Unterrichtsinhalten auseinander, benutzen das Lerntagebuch als Lerngrundlage fĆ¼r die Klausur und zur Rekapitulation der Unterrichtsinhalte.
Erfolgreich war das Lerntagebuch als Evaluationsgrundlage des Unterricht, wobei die Aussagen der SchĆ¼ler aussagekrƤftiger wurden, wenn sie die Zusicherung hatten, dass die Eintragungen nicht von der Lehrerin gelesen wĆ¼rden.
Erfolgreich war das Lerntagebuch auch in seiner diagnostischen Funktion. Es gestattet der Forscherin hilfreiche Erkenntnisse zum Lernen und vor allem zu eventuellen Lernpro-blemen bei SchĆ¼lern.
Lernerprofile:
Zur Beschreibung des Lernverhalten der SchĆ¼lerinnen und SchĆ¼ler werden Lernerprofile an-gelegt, die in Form von Einzelfallanalysen die Daten sƤmtlicher Instrumente in einer Trian-gulation vereinen und zu Profilen innerhalb der Lernergruppe bĆ¼ndeln. Die so ausgewƤhlten FƤlle stellen im Gesamtspektrum der Lerngruppe deutlich zu unterscheidende ExtremfƤlle dar, auf deren Grundlage Lernertypen zur Konturierung eines Spektrums konstruiert werden kƶn-nen, innerhalb dessen die gesamte Lernergruppe eingeordnet werden kann. Die Konstruktion von Lernertypen ist Systematisierung und Typisierung von mƶglichen individuellen Lernerpersƶnlichkeiten in einer Lerngruppe mit dem Anspruch von exemplarischer ReprƤsentativitƤt. Dabei stellt der spezielle Zugang zum Lernen die Grundlage dar
ŠŃŠµŠ½ŠŗŠ° ŠøŠ½Š²ŠµŃŃŠøŃŠøŠ¾Š½Š½Š¾Š¹ ŠæŃŠøŠ²Š»ŠµŠŗŠ°ŃŠµŠ»ŃŠ½Š¾ŃŃŠø ŠæŃŠµŠ“ŠæŃŠøŃŃŠøŃ Š½Š° ŠæŃŠøŠ¼ŠµŃŠµ ŠŠŠ Ā«Š¤Š°ŃŠ¼ŃŃŠ°Š½Š“Š°ŃŃ ā Š¢Š¾Š¼ŃŠŗŃ ŠøŠ¼ŃŠ°ŃŠ¼Ā»
ŠŠ°Š½Š½Š°Ń ŃŠ°Š±Š¾ŃŠ° ŃŠ¾Š“ŠµŃŠ¶ŠøŃ ŃŠ°ŃŃŠ¼Š¾ŃŃŠµŠ½ŠøŠµ ŃŠµŠ¾ŃŠµŃŠøŃŠµŃŠŗŠøŃ
Š¾ŃŠ½Š¾Š² ŠæŠ¾Š½ŃŃŠøŃ ŠøŠ½Š²ŠµŃŃŠøŃŠøŠ¾Š½Š½Š¾Š¹ ŠæŃŠøŠ²Š»ŠµŠŗŠ°ŃŠµŠ»ŃŠ½Š¾ŃŃŠø ŠæŃŠµŠ“ŠæŃŠøŃŃŠøŃ, ŠŗŠ»Š°ŃŃŠøŃŠøŠŗŠ°ŃŠøŃ ŃŠ°ŠŗŃŠ¾ŃŠ¾Š², Š²ŠŗŠ»ŃŃŠµŠ½Š½ŃŃ
Š² ŠµŃ Š¾ŃŠµŠ½ŠŗŃ Šø ŃŃŃŠµŃŃŠ²ŃŃŃŠøŠµ Š¼ŠµŃŠ¾Š“Ń ŠµŃ Š¾ŃŠµŠ½ŠŗŠø.
Š¦ŠµŠ»ŃŃ Š“Š°Š½Š½Š¾Š¹ ŃŠ°Š±Š¾ŃŃ ŃŠ²Š»ŃŠµŃŃŃ Š¾ŃŠµŠ½ŠŗŠ° ŠøŠ½Š²ŠµŃŃŠøŃŠøŠ¾Š½Š½Š¾Š¹ ŠæŃŠøŠ²Š»ŠµŠŗŠ°ŃŠµŠ»ŃŠ½Š¾ŃŃŠø ŠŠŠ "Š¤Š°ŃŠ¼ŃŃŠ°Š½Š“Š°ŃŃ-Š¢Š¾Š¼ŃŠŗŃ
ŠøŠ¼ŃŠ°ŃŠ¼". Š ŃŠ°Š¼ŠŗŠ°Ń
Š“Š¾ŃŃŠøŠ¶ŠµŠ½ŠøŃ Š“Š°Š½Š½Š¾Š¹ ŃŠµŠ»Šø Š±ŃŠ» Š²ŃŠ±ŃŠ°Š½ ŠæŃŠµŠ“ŠæŠ¾ŃŃŠøŃŠµŠ»ŃŠ½ŃŠ¹ Š¼ŠµŃŠ¾Š“ Š¾ŃŠµŠ½ŠŗŠø, ŠŗŠ¾ŃŠ¾ŃŃŠ¹ Š±ŃŠ» Š¼Š¾Š“ŠµŃŠ½ŠøŠ·ŠøŃŠ¾Š²Š°Š½ Šø Š¾ŠæŃŠøŠ¼ŠøŠ·ŠøŃŠ¾Š²Š°Š½ Š°Š²ŃŠ¾ŃŠ¾Š¼ Š“Š»Ń ŠæŠ¾Š»ŃŃŠµŠ½ŠøŃ Š½Š°ŠøŠ±Š¾Š»ŠµŠµ Š¾Š±ŃŠµŠŗŃŠøŠ²Š½ŃŃ
ŃŠµŠ·ŃŠ»ŃŃŠ°ŃŠ¾Š², Ń
Š°ŃŠ°ŠŗŃŠµŃŠøŠ·ŃŃŃŠøŃ
ŠæŠ¾Š»Š¾Š¶ŠµŠ½ŠøŠµ ŠæŃŠµŠ“ŠæŃŠøŃŃŠøŃ Š“Š»Ń ŠøŠ½Š²ŠµŃŃŠ¾ŃŠ¾Š².
Š ŃŠµŠ·ŃŠ»ŃŃŠ°ŃŠµ ŠøŃŃŠ»ŠµŠ“Š¾Š²Š°Š½ŠøŃ Š±ŃŠ»Šø ŃŃŠ¾ŃŠ¼ŃŠ»ŠøŃŠ¾Š²Š°Š½Ń Š²ŃŠ²Š¾Š“Ń Š¾ŃŠ½Š¾ŃŠøŃŠµŠ»ŃŠ½Š¾ ŠøŠ½Š²ŠµŃŃŠøŃŠøŠ¾Š½Š½Š¾Š¹ ŠæŃŠøŠ²Š»ŠµŠŗŠ°ŃŠµŠ»ŃŠ½Š¾ŃŃŠø ŠæŃŠµŠ“ŠæŃŠøŃŃŠøŃ, Š²ŃŠ“ŠµŠ»ŠµŠ½Ń Š¾ŃŠ½Š¾Š²Š½ŃŠµ ŃŠ°ŠŗŃŠ¾ŃŃ, Š¾ŠŗŠ°Š·ŃŠ²Š°ŃŃŠøŠµ Š½Š° Š½ŠµŃ Š½ŠµŠ³Š°ŃŠøŠ²Š½Š¾Šµ Š²Š»ŠøŃŠ½ŠøŠµ, ŃŠ°Š·ŃŠ°Š±Š¾ŃŠ°Š½Ń ŃŠµŠŗŠ¾Š¼ŠµŠ½Š“Š°ŃŠøŠø ŠæŠ¾ ŠøŃ
ŃŃŃŃŠ°Š½ŠµŠ½ŠøŃ.This work contains an examination of the theoretical foundations of the concept of the investment attractiveness of the enterprise, the classification of factors that include into its assessment and the existing methods for its evaluation.
The purpose of this work is to evaluate the investment attractiveness of OJSC "Pharmstandard-Tomskchimpharm". In the framework of achieving this goal, was selected a preferred valuation method, which was modernized and optimized by the author to obtain the most objective results that characterize the position of the enterprise for investors.
As a result of the research were drawn conclusions regarding the investment attractiveness of the enterprise, the main factors that exerted negative influence on it, identified recommendations for their elimination
The translation, validity and reliability of the German version of the Fremantle Back Awareness Questionnaire
Background: The Fremantle Back Awareness Questionnaire (FreBAQ) claims to assess disrupted self-perception of the back. The aim of this study was to develop a German version of the Fre-BAQ (FreBAQ-G) and assess its test-retest reliability, its known-groups validity and its convergent validity with another purported measure of back perception.
Methods: The FreBaQ-G was translated following international guidelines for the transcultural adaptation of questionnaires. Thirty-five patients with non-specific CLBP and 48 healthy participants were recruited. Assessor one administered the FreBAQ-G to each patient with CLBP on two separate days to quantify intra-observer reliability. Assessor two administered the FreBaQ-G to each patient on day 1. The scores were compared to those obtained by assessor one on day 1 to assess inter-observer reliability. Known-groups validity was quantified by comparing the FreBAQ-G score between patients and healthy controls. To assess convergent validity, patient\u27s FreBAQ-G scores were correlated to their two-point discrimination (TPD) scores.
Results: Intra- and Inter-observer reliability were both moderate with ICC3.1 = 0.88 (95%CI: 0.77 to 0.94) and 0.89 (95%CI: 0.79 to 0.94), respectively. Intra- and inter-observer limits of agreement (LoA) were 6.2 (95%CI: 5.0Ā±8.1) and 6.0 (4.8Ā±7.8), respectively. The adjusted mean difference between patients and controls was 5.4 (95%CI: 3.0 to 7.8, p\u3c0.01). Patient\u27s FreBAQ-G scores were not associated with TPD thresholds (Pearson\u27s r = -0.05, p = 0.79).
Conclusions: The FreBAQ-G demonstrated a degree of reliability and known-groups validity. Interpretation of patient level data should be performed with caution because the LoA were substantial. It did not demonstrate convergent validity against TPD. Floor effects of some items of the FreBAQ-G may have influenced the validity and reliability results. The clinimetric properties of the FreBAQ-G require further investigation as a simple measure of disrupted self-perception of the back before firm recommendations on its use can be made
Electronic structure of the MO oxides (M=Mg, Ca, Ti, V) in the GW approximation
The quasiparticle band structures of nonmagnetic monoxides, MO (M=Mg, Ca, Ti,
and V), are calculated by the GW approximation. The band gap and the width of
occupied oxygen 2p states in insulating MgO and CaO agree with experimental
observation. In metallic TiO and VO, conduction bands originated from metal 3d
states become narrower. Then the partial densities of transition metal e_g and
t_2g states show an enhanced dip between the two. The effects of static
screening and dynamical correlation are discussed in detail in comparison with
the results of the Hartree-Fock approximation and the static Coulomb hole plus
screened exchange approximation. The d-d Coulomb interaction is shown to be
very much reduced by on-site and off-site d-electron screening in TiO and VO.
The dielectric function and the energy loss spectrum are also presented and
discussed in detail.Comment: 10 pages, 5 figure
Lung surfactant in subacute pulmonary disease
Pulmonary surfactant is a surface active material composed of both lipids and proteins that is produced by alveolar type II pneumocytes. Abnormalities of surfactant in the immature lung or in the acutely inflamed mature lung are well described. However, in a variety of subacute diseases of the mature lung, abnormalities of lung surfactant may also be of importance. These diseases include chronic obstructive pulmonary disease, asthma, cystic fibrosis, interstitial lung disease, pneumonia, and alveolar proteinosis. Understanding of the mechanisms that disturb the lung surfactant system may lead to novel rational therapies for these diseases
Catecholamine up-regulates MMP-7 expression by activating AP-1 and STAT3 in gastric cancer
<p>Abstract</p> <p>Background</p> <p>Stress, anxiety and depression can cause complex physiological and neuroendocrine changes, resulting in increased level of stress related hormone catecholamine, which may constitute a primary mechanism by which physiological factors impact gene expression in tumors. In the present study, we investigated the effects of catecholamine stimulation on MMP-7 expression in gastric cancer cells and elucidated the molecular mechanisms of the up-regulation of MMP-7 level by catecholamine through an adrenergic signaling pathway.</p> <p>Results</p> <p>Increased MMP-7 expression was identified at both mRNA and protein levels in the gastric cancer cells in response to isoproterenol stimulation. Ī²2-AR antigonist effectively abrogated isoproterenol-induced MMP-7 expression. The activation of STAT3 and AP-1 was prominently induced by isoproterenol stimulation and AP-1 displayed a greater efficacy than STAT3 in isoproterenol-induced MMP-7 expression. Mutagenesis of three STAT3 binding sites in MMP-7 promoter failed to repress the transactivation of MMP-7 promoter and silencing STAT3 expression was not effective in preventing isoproterenol-induced MMP-7 expression. However, isoproterenol-induced MMP-7 promoter activities were completely disappeared when the AP-1 site was mutated. STAT3 and c-Jun could physically interact and bind to the AP-1 site, implicating that the interplay of both transcriptional factors on the AP-1 site is responsible for isoproterenol-stimulated MMP-7 expression in gastric cancer cells. The expression of MMP-7 in gastric cancer tissues was found to be at the site where Ī²2-AR was overexpressed and the levels of MMP-7 and Ī²2-AR were the highest in the metastatic locus of gastric cancer.</p> <p>Conclusions</p> <p>Up-regulation of MMP-7 expression through Ī²2-AR-mediated signaling pathway is involved in invasion and metastasis of gastric cancer.</p
Stabilization of G-quadruplex in the BCL2 promoter region in double-stranded DNA by invading short PNAs
Numerous regulatory genes have G-rich regions that can potentially form quadruplex structures, possibly playing a role in transcription regulation. We studied a G-rich sequence in the BCL2 gene 176-bp upstream of the P1 promoter for G-quadruplex formation. Using circular dichroism (CD), thermal denaturation and dimethyl sulfate (DMS) footprinting, we found that a single-stranded oligonucleotide with the sequence of the BCL2 G-rich region forms a potassium-stabilized G-quadruplex. To study G-quadruplex formation in double-stranded DNA, the G-rich sequence of the BCL2 gene was inserted into plasmid DNA. We found that a G-quadruplex did not form in the insert at physiological conditions. To induce G-quadruplex formation, we used short peptide nucleic acids (PNAs) that bind to the complementary C-rich strand. We examined both short duplex-forming PNAs, complementary to the central part of the BCL2 gene, and triplex-forming bis-PNAs, complementary to sequences adjacent to the G-rich BCL2 region. Using a DMS protection assay, we demonstrated G-quadruplex formation within the G-rich sequence from the promoter region of the human BCL2 gene in plasmid DNA. Our results show that molecules binding the complementary C-strand facilitate G-quadruplex formation and introduce a new mode of PNA-mediated sequence-specific targeting
- ā¦