975 resultados para Stiekna, Konrad.


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Thesis (doctoral)--Kaiser Wilhelms-Unaiversitat Strassburg.

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Thesis (doctoral)--Kaiser-Wilhelms-Universitat Strassburg.

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Thesis (doctoral)--Friedrich-Wilhelms-Universitat zu Berlin.

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Im Grubenfeld "Konrad" der Salzgitter-Erzbergbau AG bei Salzgitter-Bleckenstedt wurde ein 62 m mächtiges, von den Ornaten-Schichten (Mittel-Callovium, coronaten-Zone) bis an die Basis des Mittleren Korallenoolith (Mittel-Oxfordium, plicatilis-Zone oder Ober-Oxfordium, cautisnigrae-Zone) reichendes Profil aufgenommen und untersucht. Die Mächtigkeit der Heersumer Schichten beträgt nur 1,5 m, die des Unteren Korallenoolith ca. 60 m. Im Gegensatz zum nördlichen Teil des Gifhorner Troges (SEITZ 1950) ist die Mächtigkeit der Heersumer Schichten im südlichen Teil also erheblich geringer. Der Untere Korallenoolith ist in beiden Vorkommen etwa gleichmächtig entwickelt. Die Schichtlücke zwischen Mittel-Callovium und Unter-Oxfor- dium, die im untersuchten Profil nachgewiesen werden konnte, tritt auch am nördlichen Harzrand in der Grube "Hansa" (DENG- LER 1954) und im Wiehengebirge (LANGE 1971) auf. Offensichtlich ist sie jedoch nur lokal entwickelt, denn im Hildesheimer Jurazug (VINKEN 1974, 1975), im nördlichen Teil des Gifhorner Troges (SEITZ 1950) und am nördlichen Harzrand in unmittelbarer Nähe der Grube "Hansa" (s.o.) liegen lückenlose Profile vor. Daß diese Schichtlücken auch im Südteil des Gifhorner Troges auftreten, spricht für ein späteres Einsetzen der Trogtendenz in diesem Gebiet. Die untersuchten Schichten stimmen in ihren wesentlichen faziellen und petrographischen Merkmalen mit benachbarten Vorkommen überein. Die Zyklen im Unteren Korallenoolith werden als Ergebnis sich ablösender Transgressions- und Regressionsphasen gedeutet.

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Purpose To assess the repeatability and validity of lens densitometry derived from the Pentacam Scheimpflug imaging system. Setting Eye Clinic, Queensland University of Technology, Brisbane, Australia. Methods This prospective cross-sectional study evaluated 1 eye of subjects with or without cataract. Scheimpflug measurements and slitlamp and retroillumination photographs were taken through a dilated pupil. Lenses were graded with the Lens Opacities Classification System III. Intraobserver and interobserver reliability of 3 observers performing 3 repeated Scheimpflug lens densitometry measurements each was assessed. Three lens densitometry metrics were evaluated: linear, for which a line was drawn through the visual axis and a mean lens densitometry value given; peak, which is the point at which lens densitometry is greatest on the densitogram; 3-dimensional (3D), in which a fixed, circular 3.0 mm area of the lens is selected and a mean lens densitometry value given. Bland and Altman analysis of repeatability for multiple measures was applied; results were reported as the repeatability coefficient and relative repeatability (RR). Results Twenty eyes were evaluated. Repeatability was high. Overall, interobserver repeatability was marginally lower than intraobserver repeatability. The peak was the least reliable metric (RR 37.31%) and 3D, the most reliable (RR 5.88%). Intraobserver and interobserver lens densitometry values in the cataract group were slightly less repeatable than in the noncataract group. Conclusion The intraobserver and interobserver repeatability of Scheimpflug lens densitometry was high in eyes with cataract and eyes without cataract, which supports the use of automated lens density scoring using the Scheimpflug system evaluated in the study

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To further investigate the use of DNA repair-enhancing agents for skin cancer prevention, we treated Cdk4R24C/R24C/NrasQ61K mice topically with the T4 endonuclease V DNA repair enzyme (known as Dimericine) immediately prior to neonatal ultraviolet radiation (UVR) exposure, which has a powerful effect in exacerbating melanoma development in the mouse model. Dimericine has been shown to reduce the incidence of basal-cell and squamous cell carcinoma. Unexpectedly, we saw no difference in penetrance or age of onset of melanoma after neonatal UVR between Dimericine-treated and control animals, although the drug reduced DNA damage and cellular proliferation in the skin. Interestingly, epidermal melanocytes removed cyclobutane pyrimidine dimers (CPDs) more efficiently than surrounding keratinocytes. Our study indicates that neonatal UVR-initiated melanomas may be driven by mechanisms other than solely that of a large CPD load and/or their inefficient repair. This is further suggestive of different mechanisms by which UVR may enhance the transformation of keratinocytes and melanocytes.

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We report on a systematic analysis of genotype-specific melanocyte (MC) UVR responses in transgenic mouse melanoma models along with tumour penetrance and comparative histopathology. pRb or p53 pathway mutations cooperated with NrasQ61K to transform MCs. We previously reported that MCs migrate from the follicular outer root sheath into the epidermis after neonatal UVR. Here, we found that Arf or p53 loss markedly diminished this response. Despite this, mice carrying these mutations developed melanoma with very early age of onset after neonatal UVR. Cdk4R24C did not affect the MC migration. Instead, independent of UVR exposure, interfollicular dermal MCs were more prevalent in Cdk4R24C mice. Subsequently, in adulthood, these mutants developed dermal MC proliferations reminiscent of superficial congenital naevi. Two types of melanoma were observed in this model. The location and growth pattern of the first was consistent with derivation from the naevi, while the second appeared to be of deep dermal origin. In animals carrying the Arf or p53 defects, no naevi were detected, with all tumours ostensibly skipping the benign precursor stage in progression.

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Introduction: Emergency prehospital medical care providers are frontline health workers during emergencies. However, little is known about their attitudes, perceptions, and likely behaviors during emergency conditions. Understanding these attitudes and behaviors is crucial to mitigating the psychological and operational effects of biohazard events such as pandemic influenza, and will support the business continuity of essential prehospital services. ----- ----- Problem: This study was designed to investigate the association between knowledge and attitudes regarding avian influenza on likely behavioral responses of Australian emergency prehospital medical care providers in pandemic conditions. ----- ----- Methods: Using a reply-paid postal questionnaire, the knowledge and attitudes of a national, stratified, random sample of the Australian emergency prehospital medical care workforce in relation to pandemic influenza were investigated. In addition to knowledge and attitudes, there were five measures of anticipated behavior during pandemic conditions: (1) preparedness to wear personal protective equipment (PPE); (2) preparedness to change role; (3) willingness to work; and likely refusal to work with colleagues who were exposed to (4) known and (5) suspected influenza. Multiple logistic regression models were constructed to determine the independent predictors of each of the anticipated behaviors, while controlling for other relevant variables. ----- ----- Results: Almost half (43%) of the 725 emergency prehospital medical care personnel who responded to the survey indicated that they would be unwilling to work during pandemic conditions; one-quarter indicated that they would not be prepared to work in PPE; and one-third would refuse to work with a colleague exposed to a known case of pandemic human influenza. Willingness to work during a pandemic (OR = 1.41; 95% CI = 1.0–1.9), and willingness to change roles (OR = 1.44; 95% CI = 1.04–2.0) significantly increased with adequate knowledge about infectious agents generally. Generally, refusal to work with exposed (OR = 0.48; 95% CI = 0.3–0.7) or potentially exposed (OR = 0.43; 95% CI = 0.3–0.6) colleagues significantly decreased with adequate knowledge about infectious agents. Confidence in the employer’s capacity to respond appropriately to a pandemic significantly increased employee willingness to work (OR = 2.83; 95% CI = 1.9–4.1); willingness to change roles during a pandemic (OR = 1.52; 95% CI = 1.1–2.1); preparedness to wear PPE (OR = 1.68; 95% CI = 1.1–2.5); and significantly decreased the likelihood of refusing to work with colleagues exposed to (suspected) influenza (OR = 0.59; 95% CI = 0.4–0.9). ----- ----- Conclusions:These findings indicate that education and training alone will not adequately prepare the emergency prehospital medical workforce for a pandemic. It is crucial to address the concerns of ambulance personnel and the perceived concerns of their relationship with partners in order to maintain an effective prehospital emergency medical care service during pandemic conditions.

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Introduction: Little is known about the risk perceptions and attitudes of healthcare personnel, especially of emergency prehospital medical care personnel, regarding the possibility of an outbreak or epidemic event. Problem: This study was designed to investigate pre-event knowledge and attitudes of a national sample of the emergency prehospital medical care providers in relation to a potential human influenza pandemic, and to determine predictors of these attitudes. Methods: Surveys were distributed to a random, cross-sectional sample of 20% of the Australian emergency prehospital medical care workforce (n = 2,929), stratified by the nine services operating in Australia, as well as by gender and location. The surveys included: (1) demographic information; (2) knowledge of influenza; and (3) attitudes and perceptions related to working during influenza pandemic conditions. Multiple logistic regression models were constructed to identify predictors of pandemic-related risk perceptions. Results: Among the 725 Australian emergency prehospital medical care personnel who responded, 89% were very anxious about working during pandemic conditions, and 85% perceived a high personal risk associated with working in such conditions. In general, respondents demonstrated poor knowledge in relation to avian influenza, influenza generally, and infection transmission methods. Less than 5% of respondents perceived that they had adequate education/training about avian influenza. Logistic regression analyses indicate that, in managing the attitudes and risk perceptions of emergency prehospital medical care staff, particular attention should be directed toward the paid, male workforce (as opposed to volunteers), and on personnel whose relationship partners do not work in the health industry. Conclusions: These results highlight the potentially crucial role of education and training in pandemic preparedness. Organizations that provide emergency prehospital medical care must address this apparent lack of knowledge regarding infection transmission, and procedures for protection and decontamination. Careful management of the perceptions of emergency prehospital medical care personnel during a pandemic is likely to be critical in achieving an effective response to a widespread outbreak of infectious disease.