997 resultados para ddc:760


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Botanicals and botanical preparations, including plant food supplements (PFS), are widely used in Western diets. The growing use of PFS is accompanied by an increasing concern because the safety of these PFS is not generally assessed before they enter the market. Regulatory bodies have become more aware of this and are increasing their efforts to ensure the safety of PFS. The present review describes an overview of the general framework for the safety assessment of PFS, focusing on the different approaches currently in use to assess the safety of botanicals and/or botanical compounds, including their history of safe use, the tiered approach proposed by the European Food Safety Authority (EFSA), the Threshold of Toxicological Concern (TTC) and the...

Relevância:

10.00% 10.00%

Publicador:

Resumo:

documentstyle[12pt,german]{article} pagestyle{empty} topmargin-1.5cm textheight24.5cm footskip-1.5cm % % begin{document} % begin{center} {Large {it Hern'{a}n Rodr'{i}guez}}\ vspace{24pt} {Large {bf Elektronische Transporteigenschaften von YBa$_{2}$Cu$_{3}$O$_{7-x}$/PrBa$_{2}$Cu$_{2.9}$Ga$_{0.1}$O$_{7-y}$ Dreifachschichten und "Ubergittern senkrecht zur Lagenstruktur}} end{center} vspace{24pt} noindent In der vorliegenden Arbeit wurden die Transporteigenschaften senkrecht zu den CuO$_{2}$--Ebenen von Hochtemperatur Supraleitern an YBa$_{2}$Cu$_{3}$O$_{7-x}$/\ PrBa$_{2}$Cu$_{2.9}$Ga$_{0.1}$O$_{7-y}$/ YBa$_{2}$Cu$_{3}$O$_{7-x}$ Dreifachschichten und [(YBa$_{2}$Cu$_{3}$O$_{7-x}$)$_{n}$\/(PrBa$_{2}$Cu$_{2.9}$Ga$_{0.1}$O$_{7-y}$)$_{m}$]$_{times M}$ "Ubergittern untersucht. Um die Transporteigenschaften senkrecht zu den Grenzfl"achen in Mehrlagenstrukturen messen zu k"onnen, ist ein Verfahren zur Herstellung von planaren Bauelemente verwendet worden. Die Untersuchungen an YBa$_{2}$Cu$_{3}$O$_{7-x}$/PrBa$_{2}$Cu$_{2.9}$Ga$_{0.1}$O$_{7-y}$ Dreifachschichten und "Ubergittern zeigen, da"s die Substrattemperatur w"ahrend des Wachstums die elektronischen Eigenschaften entlang der $c$--Achse stark beeinflusst. Bei Senkung der Abscheidetemperatur ergibt sich eine "Anderung von normalmetallischem zu tunnelkontaktartigem Verhalten. Die bei 840$^circ$C hergestellten Vielfachschichten weisen sowohl eine konstante Hintergrundleitf"ahigkeit als auch eine "Uberschu"sleitf"ahigkeit bei niedrigen Spannungen auf. Dies deutet darauf hin, da"s es sich um einen Supraleiter--Normalleiter--Supraleiter (S--N--S) Kontakt handelt. Dagegen zeigen Vielfachschichten, die bei 760$^circ$C deponiert wurden, deutlich unterschiedliches Verhalten verglichen mit den bei 840$^circ$C pr"aparierte Proben. Die Leitf"ahigkeit nimmt mit der Spannung zu, wobei der Leitf"ahigkeithintergrund eine ``V''--Form darstellt. Dar"uber hinaus zeigen die Leitf"ahigkeitskennlinien bei niedrigen Spannungen eine starke Abh"angigkeit sowohl von der Bias Spannung als auch von der Temperatur. Bei Dreifachschichten mit 20 nm PrBa$_{2}$Cu$_{2.9}$Ga$_{0.1}$O$_{7-y}$ tritt ein Leitf"ahigkeitmaximun bei Null--Spannung auf. Die Wechselwirkung zwischen tunnelnden Quasiteilchen und magnetischen Momenten in der Barriere ruft dieses Maximun hervor. Das "Ubergitter mit ($n/m$) = (4/5) Modulation zeigt Supraleiter--Isolator--Supraleiter (S--I--S) Tunnelkontakt--Verhalten mit Strukturen, die von der Energiel"ucke des Supraleiters hervorgerufen werden. Das S--N-- bzw., S--I--Kontaktverhalten der Heterostrukturen wurden ebenfalls mit Messungen der Leitf"ahigkeit bei tiefern Temperaturen weit au"serhalb der supraleitenden Energiel"ucke best"atigt. Diese Ergebnisse weisen auf die M"oglichkeit hin, durch Einstellen der Substrattemperaturen bei der Deposition das Auftreten von S--N--S und S--I--S Verhalten der Kontakte zu steuern. vspace{24pt} noindent Datum: 05.07.2004\ Betreuer: Prof. Dr. Hermann Adrian %Name des Betreuers, daneben dessen Unterschrift end{document}

Relevância:

10.00% 10.00%

Publicador:

Resumo:

153 Nachkommen einer Kreuzung aus der pilzresistenten Rebsorte ‘Regent‘ und ‘Lemberger‘ als klassischer pilzsensitiver Sorte zeigen quantitative Merkmalsvariation bezüglich der Resistenz gegen Plasmopara viticola und Uncinula necator sowie für weitere Eigenschaften, die z.B. das Eintreten der Beerenreife betreffen. Auf dem Weg über die genetische Kartierung mit molekularen Markern und der Lokalisierung von QTL-Effekten konnten Hinweise auf weinbaulich relevante Genomregionen gewonnen werden; dies liefert z.B. die Basis für markergestützte Selektion bei Zuchtvorhaben mit dem Resistenzträger ‘Regent’ (vgl. auch FISCHER et al., 2004). Ein Major-QTL für die Resistenz gegen den Echten Mehltau Uncinula necator sowie zwei Major QTL für die Resistenz gegen den Erreger des Falschen Mehltau, Plasmopara viticola, traten mit hoher Signifikanz auf drei verschiedenen Kopplungsgruppen von ‘Regent‘ auf. Auch Regionen mit Relevanz für das Eintreten der Beerenreife wurden beschrieben. Über die Isolierung, Sequenzierung und anschließende Analyse einzelner Markerfragmente mit Methoden der Bioinformatik ist es gelungen, ein putatives T10P12.4-Ortholog der Weinrebe (ein thioredoxinähnliches Protein) in enger Kopplung zu einem Major-QTL-Maximum für Plasmopara viticola-Resistenz zu identifizieren, das als Kandidat für die Beteiligung an der Pathogenantwort in Frage kommt. Es konnte exemplarisch gezeigt werden, dass die eingesetzten Methoden der Kartierung und QTL-Analyse unter Verwendung PCR-basierter Markertypen wie SSR und AFLP und einer beschleunigten Analyse über computergestützte Kapillargelelektrophorese in vertretbarem Zeitrahmen bis zur Isolation potentieller Schlüsselgene führen können. Die grundsätzliche Eignung der QTL-Analyse als effizientes Werkzeug gezielter Züchtungsplanung für den Weinbau bestätigte sich. Ihre Anwendung im Rahmen der vorliegenden Dissertation hat die Basis für die Nutzung von QTL-Information bei dem Vergleich etablierter und der Entwicklung neuer Sorten gelegt und zum Verständnis von Prozessen beigetragen, die den betrachteten Eigenschaften wie der Pilzresistenz möglicherweise zu Grunde liegen. Ein großer Teil der gewonnenen Daten bringt auch die Untersuchungen anderer Kultivare voran und ist intervarietal übertragbar. Darüber hinaus haben sich Chancen für vergleichende Studien zwischen der Weinrebe einerseits und der Modellpflanze Arabidopsis thaliana sowie weiteren Kulturpflanzen andererseits abgezeichnet. Die Hinweise auf die zentrale Rolle und universelle Natur des Redox-Signalling haben interessante Perspektiven zum Verständnis organismenübergreifender physiologischer Zusammenhänge eröffnet. Dies betrifft z.B. auch die Reaktion auf Verwundung oder die Pathogenantwort.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background and Purpose— The term “minor stroke” is often used; however a consensus definition is lacking. We explored the relationship of 6 “minor stroke” definitions and outcome and tested their validity in subgroups of patients. Methods— A total of 760 consecutive patients with acute ischemic strokes were classified according to the following definitions: A, score ≤1 on every National Institutes of Health Stroke Scale (NIHSS) item and normal consciousness; B, lacunar-like syndrome; C, motor deficits with or without sensory deficits; D, NIHSS ≤9 excluding those with aphasia, neglect, or decreased consciousness; E, NIHSS ≤9; and F, NIHSS ≤3. Short-term outcome was considered favorable when patients were discharged home, and favorable medium-term outcome was defined as a modified Rankin Scale score of ≤2 at 3 months. The following subgroup analyses were performed by definition: sex, age, anterior versus posterior and right versus left hemispheric stroke, and early (0 to 6 hours) versus late admission (6 to 24 hours) to the hospital. Results— Short-term and medium-term outcomes were most favorable in patients with definition A (74% and 90%, respectively) and F (71% and 90%, respectively). Patients with definition C and anterior circulation strokes were more likely to be discharged home than patients with posterior circulation strokes (P=0.021). The medium-term outcome of older patients with definition E was less favorable compared with the outcome of younger ones (P=0.001), whereas patients with definition A, D, and F did not show different outcomes in any subgroup. Conclusions— Patients fulfilling definition A and F had best short-term and medium-term outcomes. They would be best suited to the definition of “minor stroke.”

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although the ischial spine sign (ISS) has been advocated to detect acetabular retroversion, it is unknown whether the sign is valid on anteroposterior (AP) pelvic radiographs with tilted or rotated pelves. We therefore evaluated reliability of the ISS as a tool for diagnosing acetabular retroversion in the presence of considerable pelvic tilt and/or malrotation. We obtained radiographs of 20 cadaver pelves in 19 different malorientations resulting in 380 pelvis images (760 hips) for evaluation. In addition, 129 clinical radiographs of patients' hips that had varying pelvis orientations were reviewed. We found an overall sensitivity of 81% (90%), specificity of 70% (71%), positive predictive value of 77% (80.7%), and negative predictive value of 75% (85%) in the cadaver (patient) hips. Our data suggest the ISS is a valid tool for diagnosing acetabular retroversion on plain radiographs taken using a standardized technique regardless of the degree of pelvic tilt and rotation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The presence of endothelial cell (EC)-derived surface molecules in the circulation is among hallmarks of endothelial activation and damage in vivo. Previous investigations suggest that upregulation of T-cadherin (T-cad) on the surface of ECs may be a characteristic marker of EC activation and stress. We investigated whether T-cad might also be shed from ECs and in amounts reflecting the extent of activation or damage.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim of this study involving 170 patients suffering from non-specific low back pain was to test the validity of the spinal function sort (SFS) in a European rehabilitation setting. The SFS, a picture-based questionnaire, assesses perceived functional ability of work tasks involving the spine. All measurements were taken by a blinded research assistant; work status was assessed with questionnaires. Our study demonstrated a high internal consistency shown by a Cronbach's alpha of 0.98, reasonable evidence for unidimensionality, spearman correlations of >0.6 with work activities, and discriminating power for work status at 3 and 12 months by ROC curve analysis (area under curve = 0.760 (95% CI 0.689-0.822), respectively, 0.801 (95% CI 0.731-0.859). The standardised response mean within the two treatment groups was 0.18 and -0.31. As a result, we conclude that the perceived functional ability for work tasks can be validly assessed with the SFS in a European rehabilitation setting in patients with non-specific low back pain, and is predictive for future work status.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This article introduces a new construct to the field of management called Psychological Sense of Community (PSOC). This is important because management scholars are calling for the creation of communities in organizations in an environment that lacks appropriate construct development. The aims of this article are threefold: (a) develop a working definition of PSOC via a review of the extant literature on PSOC from other disciplines with the goal of translating it into the domain of management, (b) synthesize findings from parallel literatures on the outcomes of PSOC with an eye toward exploring the relevance of such outcomes in management contexts, and (c) assess the value of PSOC as it relates to its uniqueness in relation to other prominent management constructs and its scope of applicability in a variety of management inquiry areas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

QUESTIONS UNDER STUDY: This study investigated the use among the Swiss adult population and regional dissemination of various methods of complementary medicine (CM) provided by physicians or therapists in Switzerland. METHODS: Data of the Swiss Health Survey 2007 were used, which comprised a telephone interview followed by a written questionnaire (18,760 and 14,432 respondents, respectively) and included questions about people's state of health, health insurance and usage of health services. Users and non-users of CM were compared using logistic regression models. RESULTS: The most popular CM methods were homeopathy, osteopathy, acupuncture and shiatsu/foot reflexology. 30.5% of women and 15.2% of men used at least one CM method in the 12 months preceding the survey. Lake Geneva region and central Switzerland had more CM users than the other regions. Women, people between 25 and 64 years of age and people with higher levels of education were more likely to use CM. 53.5% of the adult population had a supplemental health insurance for CM treatments. 32.9% of people with such an insurance used CM during the 12 months preceding the survey, and so did 12.0% of people without additional insurance. CONCLUSIONS: Almost one fourth of the Swiss adult population had used CM within the past 12 months. User profiles were comparable to those in other countries. Despite a generally lower self-perceived health status, elderly people were less likely to use CM.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Drug-use among teenagers in two ex-communist countries, Romania and the Republic of Moldova, was studied both in isolation and on a comparative basis. The group carried out a psycho-social study, gaining data from two representative samples of teenagers (N=713 in Romania and N=760 in Moldova). Teachers, parents and experts were also interviewed, using focus groups, questionnaires and 3 individual interviews. Aspects of the phenomenon investigated were the extent of drug use (frequency of consumption, kinds of drugs used, and categories of teenage consumers, by age, gender, residential areas, occupational status, marketplaces and traffickers); internal and external stimulating and inhibiting factors, the attitude of all four categories of subjects to drug abuse in teenagers, and strategies for combating this and other such problems.