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1.
Anal Chem ; 84(22): 9873-80, 2012 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-23098322

RESUMEN

Raman micro-spectroscopy was applied to compile a large-scale database of Raman spectra of single Bacillus endospores and to calculate classification functions, which were trained to discriminate between endospores of 66 strains from 13 Bacillus and Bacillus-related species including B. anthracis. The developed two-stage classification system comprising two support vector machines and one linear discriminant analysis classifier was then challenged by a test set of 27 samples to simulate the case of a real-world-scenario, when "unknown samples" are to be identified. In the end, all 27 test set samples including six B. anthracis strains were identified correctly. The samples thereby covered a diverse selection of species within the phylogenetically broad Bacillus genus and also included strains, which were not incorporated in the database before. All of them were correctly identified on the species level with accuracies between 88 and 100%. The sample analysis itself requires no biomass enrichment step prior to the analysis and qualifies the presented Raman spectroscopic approach to be a rapid analysis system in term of Bacillus endospore typing.


Asunto(s)
Bacillus anthracis/aislamiento & purificación , Informática/métodos , Espectrometría Raman/métodos , Análisis Discriminante , Contaminación de Alimentos , Microbiología de Alimentos , Máquina de Vectores de Soporte
3.
Appl Environ Microbiol ; 76(9): 2895-907, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20208030

RESUMEN

Micro-Raman spectroscopy is a fast and sensitive tool for the detection, classification, and identification of biological organisms. The vibrational spectrum inherently serves as a fingerprint of the biochemical composition of each bacterium and thus makes identification at the species level, or even the subspecies level, possible. Therefore, microorganisms in areas susceptible to bacterial contamination, e.g., clinical environments or food-processing technology, can be sensed. Within the scope of point-of-care-testing also, detection of intentionally released biosafety level 3 (BSL-3) agents, such as Bacillus anthracis endospores, or their products is attainable. However, no Raman spectroscopy-compatible inactivation method for the notoriously resistant Bacillus endospores has been elaborated so far. In this work we present an inactivation protocol for endospores that permits, on the one hand, sufficient microbial inactivation and, on the other hand, the recording of Raman spectroscopic signatures of single endospores, making species-specific identification by means of highly sophisticated chemometrical methods possible. Several physical and chemical inactivation methods were assessed, and eventually treatment with 20% formaldehyde proved to be superior to the other methods in terms of sporicidal capacity and information conservation in the Raman spectra. The latter fact has been verified by successfully using self-learning machines (such as support vector machines or artificial neural networks) to identify inactivated B. anthracis-related endospores with adequate accuracies within the range of the limited model database employed.


Asunto(s)
Bacillus/aislamiento & purificación , Espectrometría Raman/métodos , Esporas Bacterianas/aislamiento & purificación , Esterilización , Bacillus/clasificación , Bacillus anthracis/aislamiento & purificación , Proteínas Bacterianas/análisis , Desinfección , Viabilidad Microbiana , Esporas Bacterianas/química , Esporas Bacterianas/ultraestructura
4.
Gesundheitswesen ; 72(1): 35-40, 2010 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-19844868

RESUMEN

Three "main public health revolutions" have been described in the history of public health -the fight against communicable diseases by means of hygiene and bacteriology, the struggle against risk factors by early diagnosis and behaviour modification and the vitalisation of health resources by health promotion. This does not say much about governmental or societal strategies and their successes. In this article the development of health policies is outlined from the end of the 18 (th) century until today. What kind of state-run or social responsibilities have been defined? Have health policies been supported, constrained or pursued by the state? Has state control restricted the right of personal freedom? Public health measures were often claimed by social reformers and only hesitantly adopted by state action. It was under the special conditions of National Socialism in Germany that the "Volksgesundheit" became a national objective, achieved by selection and enforced even against the will of the persons concerned. In the aftermath, personal freedom thus acquired a high priority in health policy debates. Meanwhile this view seems to be questioned.


Asunto(s)
Política de Salud/historia , Promoción de la Salud/historia , Disparidades en Atención de Salud/historia , Programas Nacionales de Salud/historia , Prevención Primaria/historia , Factores Socioeconómicos , Alemania , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos
5.
Anal Bioanal Chem ; 379(4): 594-8, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-14963626

RESUMEN

The observation of acoustic phonons located at the surface of uncoated fibres or guided in thin films deposited on fibres by Brillouin light scattering spectroscopy (BLS) is reported. The BLS technique is non-destructive and non-intrusive and is well applicable to non-planar sample geometries. Investigations were carried out on bundles of commercially available carbon fibres, in which a single fibre was 5 microm in diameter. With regard to the detected surface acoustic excitations, each fibre can be considered as an infinite halfspace owing to the large ratio of fibre diameter to wavelength. The shear modulus, which is highly relevant for the intended technical application, was determined by measurement of the Rayleigh mode phase velocity of the uncoated fibres. These fibre bundles were coated with boron nitride (BN) in a continuously driven thermal chemical vapour deposition (CVD) process using trimethyl borate and ammonia as precursors. In comparison to carbon, BN is expected to improve the mechanical properties of fibre-reinforced composites such as fracture toughness at high temperatures. The measured velocity dispersion of the Rayleigh mode of this film-on-substrate system permitted the comparison of the shear stiffness of the carbon fibre and of the BN film material. The results evidence the desired effect of a distinct stiffness reduction of the coated fibre relative to the uncoated fibre in the near-surface region. Additional information can be obtained on the homogeneity of the deposition across the whole fibre bundle.

6.
Anal Bioanal Chem ; 375(7): 884-90, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12707755

RESUMEN

Hard BCN films were deposited by chemical vapour deposition (CVD) on Si(100) substrates. TCVD (thermal activated) and PECVD (GD or RF microwave plasma-activated, respectively) were used. The films were analysed with respect to chemical state, composition, morphology and microstructure, oxidation behaviour and hardness. Wavelength dispersive X-ray spectroscopy (EPMA), infrared spectroscopy (IR), transmission electron microscopy (TEM), differential thermal analysis (DTA) and hardness evaluation were employed for film characterization. A correlation between deposition parameters and film composition, structure and hardness could be proved in every CVD process. Parallels between TCVD and PECVD films emerged in the case of chemical composition and the correlation between carbon content and hardness values. Considerable differences exist with regard to the microstructure, especially the texture of the films. Moreover in TCVD films the carbon is preferentially incorporated between the BN basal planes, whereas in PECVD films it is incorporated preferentially in as well as between the BN basal planes.

7.
Hautarzt ; 53(4): 261-4, 2002 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-12053695

RESUMEN

Cavernous hemangiomas of the scalp associated with vascular tumors of the skull occur rarely in older patients. Giant hemangiomas can cause complications secondary to extensive bleeding. Here we report on a 78-year-old female presenting with a giant ulcerated cavernous hemangioma of the scalp. Before admission to the hospital, she had suffered from severe bleeding of the vascular tumor, with resulting anemia. Because of her cardiovascular disease, the tumor mass, and possible vascular connections to osseous hemangiomas, complete surgical removal of the hemangioma was not indicated. Therefore the superficial ulceration was covered with a split skin transplant. After complete wound healing, no further bleeding occurred.


Asunto(s)
Hemangioma Cavernoso/diagnóstico , Cuero Cabelludo , Neoplasias Cutáneas/diagnóstico , Anciano , Femenino , Estudios de Seguimiento , Hemangioma Cavernoso/patología , Hemangioma Cavernoso/cirugía , Hemorragia/patología , Hemorragia/cirugía , Humanos , Cuero Cabelludo/patología , Cuero Cabelludo/cirugía , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Trasplante de Piel
8.
Hautarzt ; 53(1): 37-41, 2002 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-11963221

RESUMEN

Osteoma cutis is a single or multiple ectope calcification with development of bony structures in the skin. We distinguish between primary and secondary ossification. Multiple miliary osteoma in the face has mostly been described secondary to preexisting acne vulgaris. We present a 62-year-old woman who developed multiple miliary osteoma in the face together with repeated doses of estrogen and discuss pathogenesis and therapeutic possibilities.


Asunto(s)
Congéneres del Estradiol/efectos adversos , Neoplasias Faciales/inducido químicamente , Osteoma/inducido químicamente , Neoplasias Cutáneas/inducido químicamente , Biopsia , Procedimientos Quirúrgicos Dermatologicos , Congéneres del Estradiol/administración & dosificación , Neoplasias Faciales/diagnóstico , Neoplasias Faciales/patología , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Terapia por Láser , Persona de Mediana Edad , Osteoma/diagnóstico , Osteoma/patología , Piel/patología , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/patología
9.
Eur J Dermatol ; 11(1): 50-3, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11174140

RESUMEN

Dapsone (4, 4' diaminodiphenylsulfone) is an efficient antiinflammatory agent. Its therapeutic use may result in a variety of adverse effects. The most frequent unwanted reactions are hemolytic anemia and methemoglobinemia. By oral route dapsone is mainly metabolized to monoacetyldapsone (MADDS) and hydroxylamine dapsone (DDS-NOH). We report a 76-year-old female patient with linear IgA dermatosis who developed a dapsone-induced photosensitivity 8 weeks after initiation of sulfone therapy. She showed a widespread erythematous eruption in UV-exposed skin area. After clearing of skin lesions the photopatch test revealed positive reactions to dapsone, MADDS and DDS-NOH. Dapsone-induced photosensitivity to date has been described only in leprosy patients. We demonstrate for the first time that this adverse reaction is not restricted to leprosy and that dapsone metabolites may also contribute to the mechanism of photosensitivity like the parent sulfone. Dapsone-induced photosensitivity is a rare, not dose-related adverse effect of the sulfone and can also occur in patients with inflammatory skin disorders.


Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Dapsona/efectos adversos , Dermatosis Facial/inducido químicamente , Inmunoglobulina A , Trastornos por Fotosensibilidad/inducido químicamente , Enfermedades Cutáneas Vesiculoampollosas/tratamiento farmacológico , Anciano , Dermatosis Facial/patología , Femenino , Humanos , Pruebas del Parche , Trastornos por Fotosensibilidad/patología , Tórax
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