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1.
Anaesthesia ; 79(2): 168-177, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37970939

RESUMO

The escalating epidemic of burnout in healthcare professionals affects provider well-being, patient care and sustainability of healthcare systems. The objective of this study was to determine the prevalence of burnout among anaesthesia care providers (consultants, trainees or nurse anaesthetists) in Switzerland and identify risk factors to develop strategies for prevention. This multicentre cross-sectional study was conducted at 22 anaesthesia departments in the German-speaking part of Switzerland, using an online questionnaire. Burnout assessment was performed using the Maslach Burnout Inventory. Additionally, the questionnaire included questions on workplace and personal risk factors. Of 1630 anaesthesia care providers contacted, 688 (42%) completed the survey. Among respondents who specified their work positions (n = 676), 52% (149/287) of nurses and 59% (229/389) of physicians were at high risk of burnout; and 9% (26/287) of nurses and 18% (70/389) of physicians met the criteria for burnout syndrome. Logistic regression analysis found significant associations between burnout and perceived lack of support at work among physicians (odds ratio (95%CI) 2.66 (1.40-5.24), p = 0.004); being a trainee in the 1st and 2nd year of training (2.91 (1.14-7.41), p = 0.024); being a trainee with > 5 years of experience (2.78 (1.08-6.98), p = 0.031); and male gender among nurses (4.13 (1.62-11.2), p = 0.004) and physicians (2.32 (1.22-4.47), p = 0.011). Work-related errors due to high workload or fatigue were reported by 65% (444/688) and consideration of leaving the profession due to working conditions was expressed by 46% (319/688) of respondents. Anaesthetic care providers in German-speaking Switzerland experience a considerable prevalence of burnout, influenced mainly by workplace factors.


Assuntos
Anestesia , Esgotamento Profissional , Humanos , Masculino , Estudos Transversais , Suíça/epidemiologia , Esgotamento Profissional/epidemiologia , Esgotamento Psicológico/epidemiologia , Inquéritos e Questionários , Prevalência
2.
J Hosp Infect ; 141: 167-174, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37696472

RESUMO

BACKGROUND: Different isolation measures are required according to the routes of transmission of pathogens. Few studies have compared different forms of hygiene training in terms of efficiency and/or improvement of perception towards hygiene measures. This study aimed to evaluate the benefits of different forms of isolation training in the operating room, and their respective effects on the perception of hygiene measures by comparing simulation training with video-based training. METHODS: This multi-centre, prospective, randomized, controlled trial compared hygiene knowledge, psychological safety and perception of training among healthcare workers after in-centre simulation training and conventional video-based training. RESULTS: Neither type of training led to a significant improvement in knowledge or perceived psychological safety (F=0.235, P=0.629, η2=0.003). Participants in the simulation group reported higher levels of willingness to speak up in the depicted scenario compared with participants who received video-based training. Participants perceived the simulation-based training significantly more positively than the video-based training. CONCLUSION: Clear definition of the goals of training based on the pre-existing level of knowledge of the participants is crucial. For future studies, it would be interesting to investigate the long-term effect and continuing benefits concerning the implementation of hygiene regulations after different types of training.


Assuntos
Salas Cirúrgicas , Treinamento por Simulação , Humanos , Estudos Prospectivos , Pessoal de Saúde , Higiene
3.
NPJ Microgravity ; 9(1): 65, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582930

RESUMO

Space levitation processing allows researchers to conduct benchmark tests in an effort to understand the physical phenomena involved in rapid solidification processing, including alloy thermodynamics, nucleation and growth, heat and mass transfer, solid/liquid interface dynamics, macro- and microstructural evolution, and defect formation. Supported by ground-based investigations, a major thrust is to develop and refine robust computational tools based on theoretical and applied approaches. This work is accomplished in conjunction with experiments designed for precise model validation with application to a broad range of industrial processes.

4.
Adv Simul (Lond) ; 6(1): 22, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34090514

RESUMO

The healthcare simulation field has no shortage of debriefing options. Some demand considerable skill which serves as a barrier to more widespread implementation. The plus-delta approach to debriefing offers the advantages of conceptual simplicity and ease of implementation. Importantly, plus-delta promotes learners' capacity for a self-assessment, a skill vital for safe clinical practice and yet a notorious deficiency in professional practice. The plus-delta approach confers the benefits of promoting uptake of debriefing in time-limited settings by educators with both fundamental but also advanced skills, and enhancing essential capacity for critical self-assessment informed by objective performance feedback. In this paper, we describe the role of plus-delta in debriefing, provide guidance for incorporating informed learner self-assessment into debriefings, and highlight four opportunities for improving the art of the plus delta: (a) exploring the big picture vs. specific performance issues, (b) choosing between single vs. double-barreled questions, (c) unpacking positive performance, and (d) managing perception mismatches.

5.
J Neurosci ; 40(41): 7795-7810, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32878902

RESUMO

Mammalian taste buds are comprised of specialized neuroepithelial cells that act as sensors for molecules that provide nutrition (e.g., carbohydrates, amino acids, and salts) and those that are potentially harmful (e.g., certain plant compounds and strong acids). Type II and III taste bud cells (TBCs) detect molecules described by humans as "sweet," "bitter," "umami," and "sour." TBCs that detect metallic ions, described by humans as "salty," are undefined. Historically, type I glial-like TBCs have been thought to play a supportive role in the taste bud, but little research has been done to explore their role in taste transduction. Some evidence implies that type I cells may detect sodium (Na+) via an amiloride-sensitive mechanism, suggesting they play a role in Na+ taste transduction. We used an optogenetic approach to study type I TBCs by driving the expression of the light-sensitive channelrhodopsin-2 (ChR2) in type I GAD65+ TBCs of male and female mice. Optogenetic stimulation of GAD65+ TBCs increased chorda tympani nerve activity and activated gustatory neurons in the rostral nucleus tractus solitarius. "N neurons," whose NaCl responses were blocked by the amiloride analog benzamil, responded robustly to light stimulation of GAD65+ TBCs on the anterior tongue. Two-bottle preference tests were conducted under Na+-replete and Na+-deplete conditions to assess the behavioral impact of optogenetic stimulation of GAD65+ TBCs. Under Na+-deplete conditions GAD65-ChR2-EYFP mice displayed a robust preference for H2O illuminated with 470 nm light versus nonilluminated H2O, suggesting that type I glial-like TBCs are sufficient for driving a behavior that resembles Na+ appetite.SIGNIFICANCE STATEMENT This is the first investigation on the role of type I GAD65+ taste bud cells (TBCs) in taste-mediated physiology and behavior via optogenetics. It details the first definitive evidence that selective optogenetic stimulation of glial-like GAD65+ TBCs evokes neural activity and modulates behavior. Optogenetic stimulation of GAD65+ TBCs on the anterior tongue had the strongest effect on gustatory neurons that responded best to NaCl stimulation through a benzamil-sensitive mechanism. Na+-depleted mice showed robust preferences to "light taste" (H2O illuminated with 470 nm light vs nonilluminated H2O), suggesting that the activation of GAD65+ cells may generate a salt-taste sensation in the brain. Together, our results shed new light on the role of GAD65+ TBCs in gustatory transduction and taste-mediated behavior.


Assuntos
Apetite/fisiologia , Preferências Alimentares/fisiologia , Glutamato Descarboxilase/fisiologia , Optogenética/métodos , Células Receptoras Sensoriais/fisiologia , Sódio/deficiência , Papilas Gustativas/fisiologia , Amilorida/farmacologia , Animais , Apetite/efeitos dos fármacos , Channelrhodopsins , Nervos Cranianos/fisiologia , Diuréticos/farmacologia , Feminino , Preferências Alimentares/efeitos dos fármacos , Glutamato Descarboxilase/efeitos dos fármacos , Masculino , Camundongos , Células Receptoras Sensoriais/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Papilas Gustativas/efeitos dos fármacos
6.
J Phys Condens Matter ; 31(45): 455101, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31342943

RESUMO

Self- and inter-diffusion coefficients in liquid Ge and dilute Ge-based Ge-Si, Ge-Au, Ge-In, Ge-Ce and Ge-Gd alloys-containing 2 at% additions, respectively, are measured using a comprehensive approach of measuring techniques: quasi-elastic neutron scattering, in situ long-capillary experiments combined with x-ray radiography, and a long-capillary experiment under microgravity conditions. Resulting inter- and Ge self-diffusion coefficients are equal within error bars for each investigated alloy. The interdiffusion coefficients are smaller for the alloys containing Ce and Gd, However, no dependence of the atomic mass of the minor additions, that varies by about a factor of seven between Si and Au, on the diffusion coefficients could be observed. This demonstrates that in a loosely-packed metallic liquid with fast diffusive dynamics the diffusion mechanism is highly collective in nature.

7.
Rev Sci Instrum ; 89(10): 103114, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399919

RESUMO

At the Metrology Light Source (MLS), the compact electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB) with a circumference of 48 m, a specific operation mode with two stable closed orbits for stored electrons was realized by transverse resonance island buckets. One of these orbits is closing only after three turns. In combination with single-bunch operation, the new mode was applied for electron time-of-flight spectroscopy with an interval of the synchrotron radiation pulses which is three times the revolution period at the MLS of 160 ns. The achievement is of significant importance for PTB's future programs of angular-resolved electron spectroscopy with synchrotron radiation and similar projects at other compact electron storage rings. The scheme applied here for selecting the photons originating from a particular orbit by optical imaging has been used before in fs slicing applications and may be relevant for the BESSY VSR project of the Helmholtz-Zentrum Berlin.

8.
Anaesthesist ; 67(8): 592-598, 2018 08.
Artigo em Alemão | MEDLINE | ID: mdl-29947817

RESUMO

BACKGROUND: In the case of a mass casualty incident an advanced medical post (AMP) plays a central role in the medical care by ambulance service and civil protection units. Besides the traditional organization with one triage category per medical services tent, it can also be structured in a mixed form (i.e. a defined number of patients with different triage categories are assigned to each medical services tent). To date it remains unclear which organization format is better in order to rapidly evacuate those patients with the highest priority. METHODS: The Medical Task Force of Lower Franconia treated 50 identical and standardized training patients including 18 triage category red/emergency (36%), 12 triage category yellow/urgent (24%), 18 triage category green/non-urgent (36%) and 2 triage category black/dead (4%) in the course of a scheduled field exercise within two consecutive training sessions (first session: classical structure, second session: mixed structure). The training patients were represented by a dynamic patient simulation, whereby simulation cards showed injury patterns and the external appearance of the patients at a defined point which required certain interventions. The patients' conditions changed when these measures were accomplished or neglected. The length of stay of the patients with the triage category red/emergency at the AMP (start of triage to start evacuation) as well as the overall number of evacuated patients were collated and compared. RESULTS: Out of 18 patients with the triage category red/emergency, 13 patients in each session were evacuated in one pass. During the first session the mean evacuation time at the AMP was 25 min and during the second session the mean evacuation time was 18 min. After the end of the 90 min of exercise time in the first session 14 non-critical patients (triage categories yellow/urgent and green/non-urgent, n = 30) were still left at the AMP (16 evacuated) and in the second session 12 (18 evacuated). CONCLUSION: Depending on the mission requirements the mixed form of AMP organization can provide several advantages. In addition to rapid operational readiness and high flexibility the patient distribution by triage category could be processed better and the evacuation time of critical patients could be shortened.


Assuntos
Estado Terminal , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/organização & administração , Incidentes com Feridos em Massa , Triagem/métodos , Ambulâncias , Feminino , Humanos , Masculino , Projetos Piloto
9.
J Chem Phys ; 148(11): 114502, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29566522

RESUMO

Electrostatic levitation is applied in order to undercool liquid glass forming NiZr significantly below its melting temperature. For NiZr large undercoolings are found to be highly reproducible with this experimental method. One single NiZr sample of high purity is undercooled 200 consecutive times which leads to a distribution function of undercooling temperatures. Within a statistical approach of classical nucleation theory, the undercooling distribution is analyzed yielding parameters, e.g., a pre-exponential factor of KV ≈ 1035 m-3 s-1, which indicates homogeneous nucleation. This result is consistent with the crystallization behavior of NiZr at high undercooling and with the corresponding microstructural analysis. Since NiZr is a representative of the very common CrB structure type, with 132 isostructural phases existing, understanding its nucleation behavior adds important knowledge to the nucleation of binary alloys in general.

10.
Rev Sci Instrum ; 85(5): 055117, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24880425

RESUMO

A rotating analyzer spectroscopic polarimeter and ellipsometer with a wide-range θ-2θ goniometer installed at the Insertion Device Beamline of the Metrology Light Source in Berlin is presented. With a combination of transmission- and reflection-based polarizing elements and the inherent degree of polarization of the undulator radiation, this ellipsometer is able to cover photon energies from about 2 eV up to 40 eV. Additionally, a new compensator design based on a CaF2 Fresnel rhomb is presented. This compensator allows ellipsometric measurements with circular polarization in the vacuum ultraviolet spectral range and thus, for example, the characterization of depolarizing samples. The new instrument was initially used for the characterization of the polarization of the beamline. The technical capabilities of the ellipsometer are demonstrated by a cohesive wide-range measurement of the dielectric function of epitaxially grown ZnO.

11.
Nat Commun ; 5: 3974, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24875774

RESUMO

Ferromagnetic thin films of Heusler compounds are highly relevant for spintronic applications owing to their predicted half-metallicity, that is, 100% spin polarization at the Fermi energy. However, experimental evidence for this property is scarce. Here we investigate epitaxial thin films of the compound Co2MnSi in situ by ultraviolet-photoemission spectroscopy, taking advantage of a novel multi-channel spin filter. By this surface sensitive method, an exceptionally large spin polarization of (93(-11)(+7)) % at room temperature is observed directly. As a more bulk sensitive method, additional ex situ spin-integrated high energy X-ray photoemission spectroscopy experiments are performed. All experimental results are compared with advanced band structure and photoemission calculations which include surface effects. Excellent agreement is obtained with calculations, which show a highly spin polarized bulk-like surface resonance ingrained in a half metallic bulk band structure.

12.
Ultramicroscopy ; 130: 63-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23639852

RESUMO

As Stern-Gerlach type spin filters do not work with electrons, spin analysis of electron beams is accomplished by spin-dependent scattering processes based on spin-orbit or exchange interaction. Existing polarimeters are single-channel devices characterized by an inherently low figure of merit (FoM) of typically 10⁻4-10⁻³. This single-channel approach is not compatible with parallel imaging microscopes and also not with modern electron spectrometers that acquire a certain energy and angular interval simultaneously. We present a novel type of polarimeter that can transport a full image by making use of k-parallel conservation in low-energy electron diffraction. We studied specular reflection from Ir (001) because this spin-filter crystal provides a high analyzing power combined with a "lifetime" in UHV of a full day. One good working point is centered at 39 eV scattering energy with a broad maximum of 5 eV usable width. A second one at about 10 eV shows a narrower profile but much higher FoM. A relativistic layer-KKR SPLEED calculation shows good agreement with measurements.

13.
Cell Death Dis ; 3: e384, 2012 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-22951981

RESUMO

The Gram-negative bacterium Shigella flexneri invades the colonic epithelium and causes bacillary dysentery. S. flexneri requires the virulence factor invasion plasmid antigen B (IpaB) to invade host cells, escape from the phagosome and induce macrophage cell death. The mechanism by which IpaB functions remains unclear. Here, we show that purified IpaB spontaneously oligomerizes and inserts into the plasma membrane of target cells forming cation selective ion channels. After internalization, IpaB channels permit potassium influx within endolysosomal compartments inducing vacuolar destabilization. Endolysosomal leakage is followed by an ICE protease-activating factor-dependent activation of Caspase-1 in macrophages and cell death. Our results provide a mechanism for how the effector protein IpaB with its ion channel activity causes phagosomal destabilization and induces macrophage death. These data may explain how S. flexneri uses secreted IpaB to escape phagosome and kill the host cells during infection and, may be extended to homologs from other medically important enteropathogenic bacteria.


Assuntos
Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Macrófagos/citologia , Shigella flexneri/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Caspase 1/metabolismo , Endossomos/metabolismo , Células HEK293 , Células HeLa , Humanos , Canais Iônicos/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Macrófagos/enzimologia , Macrófagos/microbiologia , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Técnicas de Patch-Clamp , Fagossomos/metabolismo , Fagossomos/microbiologia , Potássio/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/toxicidade , Xenopus laevis/crescimento & desenvolvimento
14.
Phys Rev Lett ; 107(20): 207601, 2011 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-22181775

RESUMO

Since the original work by Mott, the low efficiency of electron spin polarimeters, remaining orders of magnitude behind optical polarimeters, has prohibited many fundamental experiments. Here we report a solution to this problem using a novel concept of multichannel spin-polarization analysis that provides a stunning increase in efficiency by 4 orders of magnitude. This improvement was demonstrated in a setup using a hemispherical electron energy analyzer. An imaging setup proved the principal capability of resolving more than 10(5) data points in parallel.

15.
Br J Anaesth ; 106(6): 801-6, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21429954

RESUMO

BACKGROUND: Recent studies in anaesthesia and intensive care indicate that a team's ability to adapt its coordination activities to changing situational demands is crucial for effective teamwork and thus, safe patient care. This study addresses the relationship between adaptation of team coordination and markers of clinical performance in response to a critical event, particularly regarding which types of coordination activities are used and which team member engages in those coordination activities. METHODS: Video recordings of 15 two-person anaesthesia teams (anaesthesia trainee plus anaesthesia nurse) performing a simulated induction of general anaesthesia were coded, using a structured observation system for coordination activities. The simulation involved a critical event-asystole during laryngoscopy. Clinical performance was assessed using two separate reaction times related to the critical event. RESULTS: Analyses of variance revealed a significant effect of the critical event on team coordination: after the occurrence of the asystole, team members adapted their coordination activities by spending more time on information management-a specific type of coordination activity (F(1,28)=15.17, P=0.001). No significant effect was found for task management. The increase in information management was related to faster decisions regarding how to respond to the critical event, but only for trainees and not for nurses. CONCLUSIONS: Our findings support the claim that adaptation of coordination activities is related to improved team performance in healthcare. Moreover, adaptation and its relationship to team performance were found to vary with regard to type of coordination activities and team member.


Assuntos
Adaptação Psicológica , Anestesiologia/organização & administração , Competência Clínica , Equipe de Assistência ao Paciente/organização & administração , Análise e Desempenho de Tarefas , Anestesia Geral/normas , Anestesiologia/educação , Anestesiologia/normas , Tomada de Decisões , Educação de Pós-Graduação em Medicina/organização & administração , Feminino , Pesquisa sobre Serviços de Saúde/métodos , Parada Cardíaca/etiologia , Parada Cardíaca/terapia , Humanos , Gestão da Informação/normas , Laringoscopia/efeitos adversos , Masculino , Equipe de Assistência ao Paciente/normas , Simulação de Paciente , Tempo de Reação , Suíça , Gravação em Vídeo
16.
Eur Cell Mater ; 21: 144-56, 2011 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-21305477

RESUMO

The morphogen sonic hedgehog (Shh) seems to mediate adult repair processes in bone regeneration and vascularisation. In this study we investigated the effects of Shh on co-cultures consisting of human primary osteoblasts and outgrowth endothelial cells in terms of angiogenic activation and vessel maturation in comparison to the treatment with the commonly used proangiogenic factor, VEGF. Both, stimulation with VEGF or Shh, leads to an increase in the formation of microvessel-like structures compared to untreated controls. In contrast to VEGF, proangiogenic effects by Shh could already be observed after 24 h of treatment. Nevertheless, after 14 days the angiogenic activity of OEC was comparable in VEGF- or Shh-treated co-cultures. Furthermore, Shh and VEGF resulted in different growth factor expression or release profiles. Compared to VEGF, Shh stimulates also the expression and secretion of angiopoietins which was detected as early as 24 h of treatment. Moreover, smooth muscle cell-related markers, such as alpha-smooth muscle actin, desmin and myocardin, as well as basement membrane components were clearly upregulated in response to Shh treatment compared to VEGF- or untreated controls. In terms of growth factors relevant for vessel stabilisation and maturation increased levels of PDGF-BB, angiopoietin-1 and TGF-beta were observed in cell culture supernatants when treated with Shh. This was in accordance with higher levels of smooth muscle actin in Shh-treated samples indicating the potential of Shh to improve the angiogenic activity and vessel stabilisation of human tissue engineered constructs. Experiments using cyclopamine, a Shh pathway inhibitor, blocked the effects of Shh.


Assuntos
Osso e Ossos/irrigação sanguínea , Células Endoteliais/fisiologia , Proteínas Hedgehog/metabolismo , Neovascularização Fisiológica , Osteoblastos/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Actinas/genética , Inibidores da Angiogênese/farmacologia , Angiopoietina-1/genética , Angiopoietinas/genética , Membrana Basal/metabolismo , Western Blotting , Regeneração Óssea , Técnicas de Cocultura , Desmina/genética , Eletroforese em Gel de Poliacrilamida , Células Endoteliais/citologia , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Proteínas Hedgehog/farmacologia , Humanos , Osteoblastos/citologia , Reação em Cadeia da Polimerase , Receptores do Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Transformador beta/genética , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular/farmacologia
17.
Ergonomics ; 53(2): 211-28, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20099175

RESUMO

Team coordination during a simulated clean approach performed by 42 civil aviation cockpit crews was analysed. Several hypotheses regarding the adaptive use of implicit and explicit coordination, leadership and heedful interrelating were tested. The results indicate the adaptiveness of coordination to different levels of standardisation and task load and the general importance of explicit coordination for good performance. Leadership seems to be required mainly for work phases with little standardisation. In exploratory lag sequential analyses, heedful behaviour in the seven best and six worst performing crews was examined. The coordination sequences in high performance crews were found to be more succinct and well balanced, indicating that a shared sense of heedfulness is crucial for effectiveness. Theoretical implications for the conceptualisation of adaptive coordination and heedfulness and practical implications for improving crew training are discussed. Statement of Relevance: Analyses of team coordination during a simulated clean approach performed by civil aviation cockpit crews demonstrated the occurrence and effectiveness of adaptive coordination in response to different levels of task load and standardisation. Results also indicated the importance of heedful interrelating, both as a form of coordination and as a way of regulating the adaptiveness of coordination efforts. These findings have important implications for improving crew training, leadership practices and possibly also standard operating procedures.


Assuntos
Aviação/normas , Conscientização , Comportamento Cooperativo , Adulto , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Gestão da Segurança/métodos , Análise e Desempenho de Tarefas , Gravação de Videoteipe
18.
Anal Chem ; 81(5): 1770-6, 2009 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19203285

RESUMO

For the chemical speciation of binary compounds of tri- and tetravalent titanium, high-resolution X-ray absorption and emission spectra were recorded in different energy regimes in order to evaluate and to qualify both near-edge X-ray absorption fine structure (NEXAFS or XANES) spectroscopy and wavelength-dispersive X-ray emission spectroscopy (WDXES) as spectroscopic methods for this analytical task. A high resolving power in the excitation channel was ensured by use of monochromatic synchrotron radiation provided by BESSY II, where the soft X-ray emission spectra were recorded as well. In the hard X-ray range, emission measurements were performed at SPring-8. For a comparison of the information gained from the various methods, the titanium compounds were classified according to the bonded titanium's oxidation state. Thus, it was possible to distinguish between inner atomic effects due to different oxidation states and external effects related to the respective ligand and the surrounding structure. It becomes evident, that certain compounds, while hardly distinguishable in their Ti-K XANES spectra, still show significant differences in their emission characteristics. On the other hand, some compounds with little difference in their emission spectra are easily distinguished by their NEXAFS structures. Only the combined use of the complementary methods both in the soft and the hard X-ray range allows for a reliable speciation of tri- and tetravalent titanium compounds.

19.
Cell Mol Life Sci ; 63(4): 505-14, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16456617

RESUMO

Tight junctions seal intercellular clefts via membrane-related strands, hence, maintaining important organ functions. We investigated the self-association of strand-forming transmembrane tight junction proteins. The regulatory tight junction protein occludin was differently tagged and cotransfected in eucaryotic cells. These occludins colocalized within the plasma membrane of the same cell, coprecipitated and exhibited fluorescence resonance energy transfer. Differently tagged strand-forming claudin-5 also colocalized in the plasma membrane of the same cell and showed fluorescence resonance energy transfer. This demonstrates self-association in intact cells both of occludin and claudin-5 in one plasma membrane. In search of dimerizing regions of occludin, dimerization of its cytosolic C-terminal coiledcoil domain was identified. In claudin-5, the second extracellular loop was detected as a dimer. Since the transmembrane junctional adhesion molecule also is known to dimerize, the assumption that homodimerization of transmembrane tight junction proteins may serve as a common structural feature in tight junction assembly is supported.


Assuntos
Proteínas de Membrana/química , Junções Íntimas/química , Animais , Proteínas de Bactérias , Linhagem Celular , Cromatografia em Gel , Claudina-5 , Dimerização , Cães , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Proteínas de Fluorescência Verde , Humanos , Substâncias Luminescentes , Proteínas Luminescentes , Proteínas de Membrana/metabolismo , Ocludina , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo
20.
Gesundheitswesen ; 64(12): 664-8, 2002 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-12516018

RESUMO

At the first health conference in Saxony-Anhalt held at Magdeburg in March 1998 six health objectives were defined, among them the objective to increase to 90% the vaccination coverage level of the population. To achieve this goal the participants decided to establish a working group composed of representatives of 20 institutions and organisations interested in vaccination strategies. Subgroups were constituted for the following components of the objective: improvement of the data basis, completion of the special knowledge of physicians and other medical personnel, public information campaigns, and improvement of the structural framework. More than 50 actions per year were initiated or co-ordinated taking into account the special profiles of the institutions and organisations involved. In this way a better identification of the participants with the project was achieved and waste of strength and time was avoided. The data basis was assessed using generally available or newly created parameters such as the incidence of notified vaccine-preventable diseases, measles seroprevalence, and vaccination coverage levels among children aged 5-6 years. Approaches to target group related activities of the working group were derived from these parameters. The most remarkable results of these activities include the definition of age specific vaccination coverage levels, the establishment of a certificate for physicians who have completed a vaccination training course, a monthly press release on vaccination subjects, the design of a poster presentation, the composition of foil-based age group specific lectures, and the establishment of frame conditions for a recall system for practising physicians. The first hurdles on the way to a high age specific vaccination coverage levels have been taken. Further work must be done to improve the use of offered vaccinations and to complete the available data. Therefore, additional target group-related projects and actions are planned for the years to come.


Assuntos
Controle de Doenças Transmissíveis/tendências , Objetivos , Vacinação/estatística & dados numéricos , Fatores Etários , Criança , Pré-Escolar , Doenças Transmissíveis/epidemiologia , Estudos Transversais , Feminino , Previsões , Alemanha/epidemiologia , Humanos , Lactente , Masculino , Vacinação/tendências
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