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1.
Chemistry ; 30(6): e202302979, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-37950854

RESUMO

Sustainability is one of the hot topics of today's research, in particular when it comes to energy-storage systems such as batteries. Redox-active molecules implemented in organic batteries represent a promising alternative to lithium-ion batteries, which partially rely on non-sustainable heavy metal salts. As an alternative, we propose benzothiazole, -oxazole and -imidazole derivatives as redox-active moieties for polymers in organic (radical) batteries. The target molecules were identified by a combination of theoretical and experimental approaches for the investigation of new organic active materials. Herein, we present the synthesis, electrochemical characterization and theoretical investigation of the proposed molecules, which can later be introduced into a polymer backbone and used in organic polymer batteries.

2.
Artigo em Inglês | MEDLINE | ID: mdl-37587244

RESUMO

A significant proportion of patients after SARS-CoV-2 infection suffer from long-lasting symptoms. Although many different symptoms are described, the majority of patients complains about neuropsychological symptoms. Additionally, a subgroup of patients fulfills diagnostic criteria for ME/CFS. We analyzed a registry of all patients presenting in the out-patients clinic at a German university center. For patients with more than one visit, changes in reported symptoms from first to second visit were analyzed. A total of 1022 patients were included in the study, 411 of them had more than one visit. 95.5% of the patients reported a polysymptomatic disease. At the first visit 31.3% of the patients fulfilled ME/CFS criteria after a median time of 255 days post infection and and at the second visit after a median of 402 days, 19.4% still suffered from ME/CFS. Self-reported fatigue (83.7-72.7%) and concentration impairment (66.2-57.9%) decreased from first to second visit contrasting non-significant changes in the structured screening. A significant proportion of SARS-CoV-2 survivors presenting with ongoing symptoms present with ME/CFS. Although the proportion of subjective reported symptoms and their severity reduce over time, a significant proportion of patients suffer from long-lasting symptoms necessitating new therapeutic concepts.

3.
Cereb Cortex ; 32(12): 2611-2620, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34729592

RESUMO

The age- and time-dependent effects of binge drinking on adolescent brain development have not been well characterized even though binge drinking is a health crisis among adolescents. The impact of binge drinking on gray matter volume (GMV) development was examined using 5 waves of longitudinal data from the National Consortium on Alcohol and NeuroDevelopment in Adolescence study. Binge drinkers (n = 166) were compared with non-binge drinkers (n = 82 after matching on potential confounders). Number of binge drinking episodes in the past year was linked to decreased GMVs in bilateral Desikan-Killiany cortical parcellations (26 of 34 with P < 0.05/34) with the strongest effects observed in frontal regions. Interactions of binge drinking episodes and baseline age demonstrated stronger effects in younger participants. Statistical models sensitive to number of binge episodes and their temporal proximity to brain volumes provided the best fits. Consistent with prior research, results of this study highlight the negative effects of binge drinking on the developing brain. Our results present novel findings that cortical GMV decreases were greater in closer proximity to binge drinking episodes in a dose-response manner. This relation suggests a causal effect and raises the possibility that normal growth trajectories may be reinstated with alcohol abstinence.


Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Substância Cinzenta , Adolescente , Consumo de Bebidas Alcoólicas , Encéfalo/diagnóstico por imagem , Etanol/farmacologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos
4.
J Laryngol Otol ; 133(5): 386-389, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30967160

RESUMO

OBJECTIVE: Acute tonsillitis represents a significant proportion of admissions to ENT departments nationally. Given current hospital pressures, it is vital to look for safe alternatives to admission. This study explores the safe management of patients in an ambulatory medical unit, without the need for admission. METHODS: A retrospective review of 48 patients' notes was carried out. Following the development and implementation of a guideline for acute tonsillitis, a prospective re-audit of 41 patients was carried out, measuring length of stay, overnight admissions and re-admissions. RESULTS: The rate of overnight admission following implementation of the guideline fell from 0.75 to 0.29, and average length of stay dropped from 19.2 to 9.5 hours. There were two re-admissions in each cycle of the audit, which represents a non-significant increase. CONCLUSION: The tonsillitis guideline has significantly reduced admissions and length of stay. Re-admissions remain low, demonstrating that this is a safe and cost-effective intervention.


Assuntos
Instituições de Assistência Ambulatorial/normas , Assistência Ambulatorial/normas , Implementação de Plano de Saúde/métodos , Guias de Prática Clínica como Assunto , Tonsilite/terapia , Doença Aguda , Adulto , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Auditoria Médica , Admissão do Paciente/estatística & dados numéricos , Estudos Prospectivos , Estudos Retrospectivos
5.
J Mater Chem B ; 4(15): 2679-2690, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32263292

RESUMO

The Mg-Zn-Ca metallic glass system has been the focus of recent studies as a prospective material for biodegradable implants. To date, the influence each alloying element has on the degradation behaviour of this class of alloy is still not well understood. This study employs electrochemical polarisation and in situ impedance spectroscopy coupled with H2 gas collection in simulated body fluid at 37 °C to elucidate the mechanisms by which a series of custom produced Mg-Zn-Ca metallic glasses degrade compared with high purity Mg. The results show that Mg-Zn-Ca metallic glasses provide significantly more noble corrosion potentials and suppressed hydrogen gas evolution relative to high purity Mg. Furthermore, the role each element has in degradation was investigated systematically by varying the concentration of each alloying element. Testing revealed that the complex nature of dissolution in metallic glasses requires testing beyond solely polarisation and hydrogen gas collection to elucidate degradation behaviour in vitro. Practical limits to which the composition may be adjusted in this ternary alloy system, so as to maintain minimal degradation, have been achieved.

6.
Rev Sci Instrum ; 83(6): 063103, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22755611

RESUMO

An instrument is described, which measures the efficiency of Förster resonance energy transfer (FRET) in parallel to the sample's turbidity. The instrument was used to study the film formation from polymer latex dispersions. In this context, the FRET efficiency reflects the diffusion of polymer chains across the interparticle boundaries, while the loss of turbidity reflects the progress of particle deformation. Particle deformation causes tensile in-plane stress, while polymer interdiffusion creates cohesion and thereby helps to prevent cracking. The relative timing between the two therefore is of fundamental importance for successful film formation. The on-line determination of FRET efficiency while the film dries is complicated by the fact that the fluorescence lifetime of the donor, τ(D), depends on the water content in the vicinity of the donor. In the established procedure for data analysis, drifts in τ(D) induce corresponding artifical drifts in the values of the FRET efficiency. A novel algorithm for the analysis of fluorescence decay profiles is proposed, which makes use of the method of moments. The FRET efficiency is quantified by the upward curvature of the fluorescence decay curve in log-linear display. In the application example, interdiffusion is delayed relative to particle deformation by about 10 min. For successful film formation, this delay should be as small as possible.

7.
Proc IEEE Int Symp Biomed Imaging ; 2012: 122-125, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-28603582

RESUMO

Segmenting regions of high angiogenic activity corresponding to malignant tumors from DCE-MRI is a time-consuming task requiring processing of data in 4 dimensions. Quantitative analyses developed thus far are highly sensitive to external factors and are valid only under certain operating assumptions, which need not be valid for breast carcinomas. In this paper, we have developed a novel Statistical Learning Algorithm for Tumor Segmentation (SLATS) for automatically segmenting cancer from a region selected by the user on DCE-MRI. In this preliminary study, SLATS appears to demonstrate high accuracy (78%) and sensitivity (100%) in segmenting cancers from DCE-MRI when compared to segmentations performed by an expert radiologist. This may be a useful tool for delineating tumors for image-guided interventions.

8.
Artigo em Inglês | MEDLINE | ID: mdl-28626350

RESUMO

Flow Doppler imaging has become an integral part of an echocardiographic exam. Automated interpretation of flow doppler imaging has so far been restricted to obtaining hemodynamic information from velocity-time profiles depicted in these images. In this paper we exploit the shape patterns in Doppler images to infer the similarity in valvular disease labels for purposes of automated clinical decision support. Specifically, we model the similarity in appearance of Doppler images from the same disease class as a constrained non-rigid translation transform of the velocity envelopes embedded in these images. The shape similarity between two Doppler images is then judged by recovering the alignment transform using a variant of dynamic shape warping. Results of similarity retrieval of doppler images for cardiac decision support on a large database of images are presented.

9.
Adv Hematol ; 2009: 175234, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20169121

RESUMO

Background. We developed a completely closed system based on gravity separation without centrifugation steps for separation of whole blood. With this new system we compared quality and stability of the processed blood components (PRC and plasma) with respect to classical preparation. Furthermore the cost-effectiveness of this hollow fibre system was evaluated. Study Design and Methods. Whole blood collections of 15 regular blood donors were used for component preparation using the U shaped hollow fibre filter device. Results were compared to 15 whole blood preparations using centrifugation. The following parameters were evaluated: total hemoglobin, leukocyte counts, the serum concentration of total protein, lactate dehydrogenase (LDH) and potassium. Furthermore ATIII, vWF and F VIII were analyzed at different timepoints. Results. packed red cells: the data directly after separation and after 42 days of storage are in line with the guidelines of the council of Europe. Plasma. all plasma quality data are in line with the guidelines of the council of Europe for quality assurance of plasma, except for a low protein amount (factor 0.75). Conclusion. Separation of whole blood on a clinical scale in this new closed system is feasible, however the plasma protein content must be optimized.

10.
J Phys Condens Matter ; 21(31): 314016, 2009 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-21828577

RESUMO

Using low-energy electron microscopy, we measure the diffusion of Pd into bulk Cu at the Cu(100) surface. Interdiffusion is tracked by measuring the dissolution of the Cu(100)-c(2 × 2)-Pd surface alloy during annealing (T>240 °C). The activation barrier for Pd diffusion from the surface alloy into the bulk is determined to be (1.8 ± 0.6) eV. During annealing, we observe the growth of a new layer of Cu near step edges. Under this new Cu layer, dilute Pd remaining near the surface develops a layered structure similar to the Cu(3)Pd L 1(2) bulk alloy phase.

11.
Proc IEEE Int Symp Biomed Imaging ; 2008: 812-815, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-28593030

RESUMO

Change detection is a critical task in the diagnosis of many slowly evolving pathologies. This paper describes an approach that semi-automatically performs this task using longitudinal medical images. We are specifically interested in meningiomas, which experts often find difficult to monitor as the tumor evolution can be obscured by image artifacts. We test the method on synthetic data with known tumor growth as well as ten clinical data sets. We show that the results of our approach highly correlate with expert findings but seem to be less impacted by inter- and intra-rater variability.

12.
Phys Rev Lett ; 96(24): 246103, 2006 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-16907257

RESUMO

A key challenge in thin-film growth is controlling structure and composition at the atomic scale. We have used spatially resolved electron scattering to measure how the three-dimensional composition profile of an alloy film evolves with time at the nanometer length scale. We show that heterogeneity during the growth of Pd on Cu(001) arises naturally from a generic step-overgrowth mechanism relevant in many growth systems.

13.
Dev Med Child Neurol ; 47(4): 252-6, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15832548

RESUMO

The aim of this study was to propose a classification system for childhood arterial ischaemic stroke (AIS). Subtypes from the Trial of Org 10172 in Acute Stroke Therapy (TOAST) classification, previously shown to be applicable to children, were retained in the proposed Paediatric Stroke Classification (PSC). Additional important paediatric AIS aetiologies were identified from a literature review. Preliminary validation was performed by three raters who categorized clinical vignettes from 135 patients (66 male; median age 6.3 y, range 0.1 to 16 y). Eight aetiological subtypes were identified and defined, as follows: (1) sickle cell disease; (2) cardioembolic; (3) moyamoya syndrome; (4) cervical arterial dissection; (5) steno-occlusive cerebral arteriopathy; (6) other determined aetiology; (7) multiple probable/possible aetiologies; and (8) undetermined aetiology. There was very good agreement between the raters about categorization of the vignettes. Causes of disagreement were identified and final categories and definitions were modified accordingly. We conclude that the PSC enables the categorization of children with AIS into aetiological subtypes relevant to this age group. This will be useful in multicentre studies of natural history and treatment but will require further independent validation.


Assuntos
Isquemia Encefálica/classificação , Índice de Gravidade de Doença , Acidente Vascular Cerebral/classificação , Adolescente , Anemia Falciforme/complicações , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/etiologia , Dissecação da Artéria Carótida Interna/complicações , Infarto Cerebral/complicações , Criança , Pré-Escolar , Sulfatos de Condroitina/uso terapêutico , Coleta de Dados/métodos , Dermatan Sulfato/uso terapêutico , Feminino , Fibrinolíticos/uso terapêutico , Heparitina Sulfato/uso terapêutico , Humanos , Lactente , Recém-Nascido , Arteriosclerose Intracraniana/complicações , Imageamento por Ressonância Magnética/métodos , Masculino , Doença de Moyamoya/complicações , Reprodutibilidade dos Testes , Literatura de Revisão como Assunto , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia
14.
Phys Rev Lett ; 93(16): 166101, 2004 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15525006

RESUMO

We find that less than 0.01 monolayer of S can enhance surface self-diffusion on Cu(111) by several orders of magnitude. The measured dependence of two-dimensional island decay rates on S coverage (theta(S)) is consistent with the proposal that Cu3S3 clusters are responsible for the enhancement. Unexpectedly, the decay and ripening are diffusion limited with very low and very high theta(S) but not for intermediate theta(S). To explain this result we propose that surface mass transport in the intermediate region is limited by the rate of reaction to form Cu3S3 clusters on the terraces.

16.
Ceska Gynekol ; 68(3): 152-5, 2003 May.
Artigo em Tcheco | MEDLINE | ID: mdl-12879652

RESUMO

OBJECTIVE: Implementation of minimally invasive selective ischemization of uterine leiomyomas at fertile age women. DESIGN: Pilot study. SETTINGS: Gynecological institute GynCentrum, Prague. SUBJECT AND METHODS: Ultrasound guided laparoscopic electro-coagulation of myoma's vascular stalk was carried out at consecutive 48 women during June 2000-June 2002. RESULTS: Significant reduction of the original size of the leiomyoma was achieved at 98% of women during 3 months after the surgery. No surgery complications were observed as well as any obstetrical complications at five patients getting pregnant after the procedure. CONCLUSION: In addition to good therapeutic effect this minimally invasive technique brings more rapid recovery, smaller visible incisions and reduced complication, particularly during consequent pregnancy.


Assuntos
Eletrocoagulação , Laparoscopia , Leiomioma/irrigação sanguínea , Leiomioma/cirurgia , Ultrassonografia de Intervenção , Neoplasias Uterinas/irrigação sanguínea , Neoplasias Uterinas/cirurgia , Adulto , Artérias/cirurgia , Feminino , Humanos , Leiomioma/diagnóstico por imagem , Projetos Piloto , Neoplasias Uterinas/diagnóstico por imagem
17.
Dev Med Child Neurol ; 45(4): 229-32, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12647923

RESUMO

Ischaemic stroke subtypes in children and adults were compared to determine the similarity in aetiologies. Thirty-six children (22 females, 14 males; median age 5 years 7 months, range 6 weeks to 15 years 10 months) and 50 adults (35 males, 15 females; median age 44 years, range 17 years 2 months to 49 years 11 months) who had presented with ischaemic stroke between 1995 and 2000, were categorized using a modified version of the Trial of Org 10172 in Acute Stroke Therapy (TOAST) classification. Proportions of patients in the subtypes of the TOAST classification system were significantly different in the two groups (chi2 test, p<0.01). The first three subtypes (large artery atherosclerosis, cardioembolic, and small vessel disease) accounted for the majority of adult strokes (27 of 50). In contrast, only three of 36 children were accounted for within these three subtypes. The majority of children (29 of 36) were classified within the 'other determined aetiology' subtype. Aetiology was undetermined in 12 of 50 adults compared with three of 36 children. Causes of ischaemic stroke in children and adults are distinct. A classification system for ischaemic stroke in children would be useful for collaborative studies.


Assuntos
Isquemia Encefálica/classificação , Adolescente , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Isquemia Encefálica/etiologia , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X
18.
Arch Dis Child ; 88(3): 267-9, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12598402

RESUMO

Five cases of ischaemic stroke preceded by minor head trauma in children are described. All patients had striatocapsular infarction. Three had no cerebrovascular abnormality; two had turbulent flow in the proximal middle cerebral artery. None of the patients had evidence of arterial dissection or any other risk factors for stroke. All made an excellent neurological recovery. Possible mechanisms include mechanical disruption to the flow in the perforating branches of the middle cerebral artery, intimal trauma and subsequent thrombosis, or arterial spasm induced by trauma. The specific susceptibility in affected children remains unexplained; both genetic and environmental factors (for example, previous chickenpox) may be implicated.


Assuntos
Traumatismos Craniocerebrais/complicações , Acidente Vascular Cerebral/etiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Angiografia por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia
19.
G Ital Med Lav Ergon ; 25 Suppl(3): 235-6, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-14979165

RESUMO

We re-investigated 13 workers 6 years (SD 2) after the first diagnosis of asthma or rhinitis caused by latex, to update the exposure to latex, the eventual symptoms, respiratory function (spirometry and metacholine PD20 FEV1), skin prick test to common allergens and latex, RAST to latex, total IgE levels and eosinophils count in the blood. At the follow up, all the workers stopped wearing powdered latex gloves, but for 10 an indirect exposure to latex was still possible. All cases referred improvement of respiratory symptoms at work, but 7 workers occasionally complained of mild symptoms. No statistically significant variations of respiratory function test and of the immunological parameters were found. The workers with persistent respiratory symptoms at work had a longer duration of symptoms before the diagnosis (p = 0.02), if compared with workers without symptoms.


Assuntos
Asma/diagnóstico , Hipersensibilidade ao Látex/complicações , Doenças Profissionais/diagnóstico , Rinite/diagnóstico , Asma/etiologia , Asma/fisiopatologia , Seguimentos , Volume Expiratório Forçado , Humanos , Doenças Profissionais/etiologia , Doenças Profissionais/fisiopatologia , Rinite/etiologia , Rinite/fisiopatologia
20.
Arch Dis Child ; 87(3): 223-4, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12193432

RESUMO

Headaches and papilloedema are key features of idiopathic (benign) intracranial hypertension (IIH). We describe three children in whom IIH was diagnosed in the absence of papilloedema. Recognition of atypical cases of IIH is important because pressure lowering treatment may be effective.


Assuntos
Cefaleia/etiologia , Hipertensão Intracraniana/complicações , Papiledema/etiologia , Transtornos da Visão/etiologia , Acetazolamida/uso terapêutico , Inibidores da Anidrase Carbônica/uso terapêutico , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Hipertensão Intracraniana/diagnóstico , Hipertensão Intracraniana/tratamento farmacológico , Masculino
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