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1.
Plant Biol (Stuttg) ; 26(2): 330-345, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38196270

RESUMO

Mixed-species forests are promoted as a forest management strategy for climate change adaptation, but whether they are more resistant to drought than monospecific forests remains contested. In particular, the trait-based mechanisms driving the role of tree diversity under drought remain elusive. Using tree cores from a large-scale biodiversity experiment, we investigated tree growth and physiological stress responses (i.e. increase in wood carbon isotopic ratio; δ13 C) to changes in climate-induced water availability (wet to dry years) along gradients in neighbourhood tree species richness and drought-tolerance traits. We hypothesized that neighbourhood species richness increases growth and decreases δ13 C and that these relationships are modulated by the abiotic (i.e. climatic conditions) and the biotic context. We characterised the biotic context using drought-tolerance traits of focal trees and their neighbours. These traits are related to cavitation resistance versus resource acquisition and stomatal control. Tree growth increased with neighbourhood species richness. However, we did not observe a universal relief of water stress in species-rich neighbourhoods. The effects of neighbourhood species richness and climate on growth and δ13 C were modulated by the traits of focal trees and the traits of their neighbours. At either end of each drought-tolerance gradient, species responded in opposing directions during dry and wet years. We show that species' drought-tolerance traits can explain the strength and nature of biodiversity-ecosystem functioning relationships in experimental tree communities experiencing drought. Mixing tree species can increase growth but may not universally relieve drought stress.


Assuntos
Ecossistema , Árvores , Árvores/fisiologia , Secas , Florestas , Madeira
2.
J Neural Eng ; 17(1): 016008, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31683267

RESUMO

OBJECTIVE: Error-related potentials (ErrP) are generated in the brain when humans perceive errors. These ErrP signals can be used to classify actions as erroneous or non-erroneous, using single-trial electroencephalography (EEG). A small number of studies have demonstrated the feasibility of using ErrP detection as feedback for reinforcement-learning-based brain-computer interfaces (BCI), confirming the possibility of developing more autonomous BCI. These systems could be made more efficient with specific information about the type of error that occurred. A few studies differentiated the ErrP of different errors from each other, based on direction or severity. However, errors cannot always be categorised in these ways. We aimed to investigate the feasibility of differentiating very similar error conditions from each other, in the absence of previously explored metrics. APPROACH: In this study, we used two data sets with 25 and 14 participants to investigate the differences between errors. The two error conditions in each task were similar in terms of severity, direction and visual processing. The only notable differences between them were the varying cognitive processes involved in perceiving the errors, and differing contexts in which the errors occurred. We used a linear classifier with a small feature set to differentiate the errors on a single-trial basis. MAIN RESULTS: For both data sets, we observed neurophysiological distinctions between the ErrPs related to each error type. We found further distinctions between age groups. Furthermore, we achieved statistically significant single-trial classification rates for most participants included in the classification phase, with mean overall accuracy of 65.2% and 65.6% for the two tasks. SIGNIFICANCE: As a proof of concept our results showed that it is feasible, using single-trial EEG, to classify these similar error types against each other. This study paves the way for more detailed and efficient learning in BCI, and thus for a more autonomous human-machine interaction.


Assuntos
Interfaces Cérebro-Computador/classificação , Eletroencefalografia/classificação , Força da Mão/fisiologia , Desempenho Psicomotor/fisiologia , Projetos de Pesquisa , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Processamento de Sinais Assistido por Computador , Adulto Jovem
3.
Klin Padiatr ; 228(6-07): 319-324, 2016 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-27846662

RESUMO

Based on a case report an overview on the differential diagnostic considerations with respect to blood hypereosinophilia (HE) and hypereosinophilic syndromes (HES) in childhood is given. A 13-year-old boy was admitted for the clarification of an asthma. In the blood count an increased HE with 3 500/µl (30%) was found along with elevated total serum IgE and IL-5 level (2 000 IU/ml and 17 pg/ml). Lung function showed an obstruction (FEV1 38%). Radiologically the picture of bronchiectasis and mucus pluggine appeared. In the BAL a HE (76%) with raised IL-5 level was apparent. Histologically asthma was diagnosed with mucostasis, hypertrophy of the bronchial wall musculature and a lung HE. Differential-diagnostically an ABPA, a Churg-Strauss-Syndrome, a parasitosis, drug associated HE, allergies and malignant disease could be excluded. An aberrant T-cell clone in peripheral blood was detected by flow cytometry and T-cell receptor clonal rearrangements by PCR, leading to the diagnosis of a lymphoid variant of HES (L-HES). Failure to detect the FIP1L1-PDGFRA gene fusion and a normal bone marrow examination could exclude a neoplastic HES (HESN). After steroid initiation, prompt decrease of blood eosinophilia with resolution of symptoms was observed. Steroid discontinuation led to eosinophilia recurrence associated with disease symptoms. As steroid-sparing agent the immunosuppressive azathioprine was additionally given; steroid doses could be decreased and stopped in the course. This case demonstrated the range of HE evaluation in infancy. With asthma one should also consider the possibility of a L-HES.


Assuntos
Asma/diagnóstico , Asma/imunologia , Síndrome Hipereosinofílica/diagnóstico , Síndrome Hipereosinofílica/imunologia , Linfócitos T/imunologia , Adolescente , Asma/genética , Asma/patologia , Azatioprina/uso terapêutico , Biópsia por Agulha , Medula Óssea/patologia , Brônquios/patologia , Diagnóstico Diferencial , Citometria de Fluxo , Volume Expiratório Forçado/fisiologia , Humanos , Síndrome Hipereosinofílica/genética , Síndrome Hipereosinofílica/patologia , Imunoglobulina E/sangue , Interleucina-5/sangue , Pulmão/patologia , Proteínas de Fusão Oncogênica/genética , Eosinofilia Pulmonar/diagnóstico , Eosinofilia Pulmonar/genética , Eosinofilia Pulmonar/imunologia , Eosinofilia Pulmonar/patologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética
4.
Ann Oncol ; 27(6): 1155-1160, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27013395

RESUMO

BACKGROUND: Over the past decade, numerous reports describe the generation and increasing utility of non-small-cell lung cancer (NSCLC) patient-derived xenografts (PDX) from tissue biopsies. While PDX have proven useful for genetic profiling and preclinical drug testing, the requirement of a tissue biopsy limits the available patient population, particularly those with advanced oligometastatic disease. Conversely, 'liquid biopsies' such as circulating tumour cells (CTCs) are minimally invasive and easier to obtain. Here, we present a clinical case study of a NSCLC patient with advanced metastatic disease, a never smoker whose primary tumour was EGFR and ALK wild-type. We demonstrate for the first time, tumorigenicity of their CTCs to generate a patient CTC-derived eXplant (CDX). PATIENTS AND METHODS: CTCs were enriched at diagnosis and again 2 months later during disease progression from 10 ml blood from a 48-year-old NSCLC patient and implanted into immunocompromised mice. Resultant tumours were morphologically, immunohistochemically, and genetically compared with the donor patient's diagnostic specimen. Mice were treated with cisplatin and pemetrexed to assess preclinical efficacy of the chemotherapy regimen given to the donor patient. RESULTS: The NSCLC CDX expressed lung lineage markers TTF1 and CK7 and was unresponsive to cisplatin and pemetrexed. Examination of blood samples matched to that used for CDX generation revealed absence of CTCs using the CellSearch EpCAM-dependent platform, whereas size-based CTC enrichment revealed abundant heterogeneous CTCs of which ∼80% were mesenchymal marker vimentin positive. Molecular analysis of the CDX, mesenchymal and epithelial CTCs revealed a common somatic mutation confirming tumour origin and showed CDX RNA and protein profiles consistent with the predominantly mesenchymal phenotype. CONCLUSIONS: This study shows that the absence of NSCLC CTCs detected by CellSearch (EpCAM(+)) does not preclude CDX generation, highlighting epithelial to mesenchymal transition and the functional importance of mesenchymal CTCs in dissemination of this disease.


Assuntos
Biomarcadores Tumorais/genética , Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Células Neoplásicas Circulantes/patologia , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Cisplatino/administração & dosagem , Proteínas de Ligação a DNA/genética , Transição Epitelial-Mesenquimal/genética , Humanos , Células-Tronco Mesenquimais/patologia , Camundongos , Mutação , Células Neoplásicas Circulantes/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Pemetrexede/administração & dosagem , Fatores de Transcrição/genética , Ensaios Antitumorais Modelo de Xenoenxerto
5.
J Craniomaxillofac Surg ; 44(5): 622-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27017106

RESUMO

The present study analyses the exclusive use of absorbable suture material (Vicryl(®), Ethicon, Germany) in the fixation of transposed bone segments in craniofacial surgery without modification of the osteotomy design. Among 129 children up to 24 months of age, osteosynthesis was conducted exclusively with Vicryl(®) sutures. The stability of postoperative results was evaluated and possible foreign body reactions were examined within the framework of clinical and radiological routine checks. All examined children exhibited stable postoperative conditions while the length of hospital stay was not affected. X-ray examinations of the skull in two planes demonstrated good bony union in all cases. Relevant foreign body reactions were not observed. The exclusive application of absorbable suture material enables stable and cost effective osteosynthesis. Significant foreign body reactions were not observed. The exclusive use of absorbable sutures did not alter the osteotomy design.


Assuntos
Implantes Absorvíveis , Craniossinostoses/cirurgia , Suturas , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
6.
J Hum Nutr Diet ; 29(2): 217-24, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25722119

RESUMO

BACKGROUND: Baby Boomer men (those born in 1946-1964) are becoming obese at an earlier age compared to previous generations. The present study aimed to identify weight-loss strategies used by Baby Boomer men, to determine whether those strategies varied by weight status and to explore their dieting experiences. METHODS: The study used a cross-sectional survey of 211 men and 20 in-depth interviews. RESULTS: Men had a mean (SD) body mass index (BMI) of 29.35 (5.07) kg m(-2), with 82% being overweight or obese. Fifty-six percent were currently trying to lose weight. Healthy weight-loss strategies included reducing portions, increasing physical activity, cutting back on fried foods, cutting back on sweets, cutting back on alcohol, using meal replacement drinks/bars and joining a weight-loss programme. Unhealthy strategies included skipping meals and using over-the-counter 'diet pills'. Men who reduced portions, skipped meals, cut back on sweets, joined a weight-loss programme and used diet pills had significantly higher BMIs than men who said they did not (P < 0.05 for all). Interviews revealed that older men struggle to lose weight, 'I've been struggling for the last 2-3 years'. 'The last time I really tried to lose weight I stayed on the diet for just a day or two'. Wives were considered essential to their weight management success. CONCLUSIONS: Men used a do-it-yourself weight-loss approach using both healthy and unhealthy strategies. Obese men were more likely to use unhealthy practices than overweight men.


Assuntos
Obesidade/terapia , Sobrepeso/terapia , Redução de Peso , Programas de Redução de Peso/métodos , Índice de Massa Corporal , Estudos Transversais , Dieta Redutora , Exercício Físico , Nível de Saúde , Humanos , Masculino , Refeições , Pessoa de Meia-Idade
9.
Artigo em Francês | MEDLINE | ID: mdl-24388628

RESUMO

INTRODUCTION: Obstructive Sleep Apnea Syndrome (OSAS), when associated with adverse skeletal dysmorphia, can be managed by curative surgery i.e. advanced maxillomandibular associated with genioplasty and uvulopalatoglossoplasty ("6 in 1"). The purpose of this study was to assess the functional impact of this procedure. MATERIALS AND METHODS: This retrospective study was made on 27 patients with OSAS surgically treated between 1998 and 2009. The functional results were considered satisfactory when postoperative apnea/hypopnea index (AHI) was <15/h and/or at least decreased by 50%. RESULTS: After surgical treatment, the AHI dropped below 15/h for 70.4%, and for 92.6% it was at least decreased by 50%, one year after surgery. A significant concomitant decrease of the body mass index (BMI) was also observed. DISCUSSION: This "6 in 1" surgical management seemed to effectively treat OSAS in the selected cases.


Assuntos
Procedimentos Cirúrgicos Bucais/métodos , Polissonografia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/cirurgia , Adulto , Idoso , Feminino , Mentoplastia , Glossectomia , Humanos , Masculino , Avanço Mandibular , Pessoa de Meia-Idade , Palato/cirurgia , Estudos Retrospectivos , Sono/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Resultado do Tratamento , Úvula/cirurgia
10.
Eur J Radiol ; 82(6): e286-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23394760

RESUMO

OBJECTIVE: Standard stroke CT protocols start with non-enhanced CT followed by perfusion-CT (PCT) and end with CTA. We aimed to evaluate the influence of the sequence of PCT and CTA on quantitative perfusion parameters, venous contrast enhancement and examination time to save critical time in the therapeutic window in stroke patients. METHODS AND MATERIALS: Stroke CT data sets of 85 patients, 47 patients with CTA before PCT (group A) and 38 with CTA after PCT (group B) were retrospectively analyzed by two experienced neuroradiologists. Parameter maps of cerebral blood flow, cerebral blood volume, time to peak and mean transit time and contrast enhancements (arterial and venous) were compared. RESULTS: Both readers rated contrast of brain-supplying arteries to be equal in both groups (p=0.55 (intracranial) and p=0.73 (extracranial)) although the extent of venous superimposition of the ICA was rated higher in group B (p=0.04). Quantitative perfusion parameters did not significantly differ between the groups (all p>0.18), while the extent of venous superimposition of the ICA was rated higher in group B (p=0.04). The time to complete the diagnostic CT examination was significantly shorter for group A (p<0.01). CONCLUSION: Performing CTA directly after NECT has no significant effect on PCT parameters and avoids venous preloading in CTA, while examination times were significantly shorter.


Assuntos
Angiografia Cerebral/métodos , Infarto Cerebral/diagnóstico por imagem , Imagem de Perfusão/métodos , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Infarto Cerebral/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Acidente Vascular Cerebral/etiologia , Adulto Jovem
11.
Curr Pharm Biotechnol ; 13(8): 1513-21, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22283763

RESUMO

INTRODUCTION: In linkage and association studies the DTNBP1 gene has been identified as a major susceptibility gene for schizophrenia. Reduced expression of DTNBP1 was found in the hippocampus and prefrontal cortex in post mortem brains of schizophrenic patients. In vitro and animal models provide evidence that the DTNBP1 gene product dysbindin modulates the activity of the neurotransmitter glutamate in hippocampal neurons and is crucial for cell functioning and synaptogenesis. This study is the first to investigate the effects of genetic variants of DTNBP1 on the status of the glutamate system as well as neuronal integrity (N-acetylaspartate, NAA) in the hippocampus and a cortical region, the anterior cingulate cortex (ACC), in humans. METHODS: In 79 healthy subjects, the association of single nucleotide polymorphisms (SNPs) rs760665 and rs909706 with absolute concentrations of glutamate and NAA in the left hippocampus and the ACC were investigated, using proton magnetic resonance spectroscopy (MRS) at 3 Tesla and a well established quantification procedure. RESULTS: Hippocampal glutamate concentration was significantly affected by genotype of rs760665 (F=4.406, df=2,p=0.016) and rs909706 (F=3.171,df=2,p=0.048). For the concentration of NAA, a weak association with rs760665 was observed in the contrast analysis. None of the metabolites measured in the ACC showed a significant connection with either genotype. CONCLUSION: The results support a role of DTNBP1 gene variants in the glutamate neurotransmission system in the human brain at least in the hippocampus. This is compatible to growing evidence of a crucial role of glutamate in the pathobiology of schizophrenia. In addition, the weak association between DTNBP1 genotype and NAA is in line with a regulatory influence of dysbindin on synaptogenesis and neuronal survival.


Assuntos
Proteínas de Transporte/genética , Ácido Glutâmico/fisiologia , Hipocampo/fisiologia , Transmissão Sináptica/fisiologia , Adulto , Disbindina , Proteínas Associadas à Distrofina , Feminino , Genótipo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Polimorfismo de Nucleotídeo Único , Adulto Jovem
12.
Med Klin Intensivmed Notfmed ; 106(2): 103-10, 2011 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-22038634

RESUMO

The role of diagnostic imaging in pediatric intensive care units (PICU) includes primary diagnosis, monitoring of the patient's progress, and the assessment of interventional procedures. Images should be acquired in the PICU, not only to minimize the time interval between image acquisition and image interpretation but also in order to avoid unnecessary and maybe harmful transportation of the patient. Portable, optimized equipment is warranted. Most images are acquired as conventional X-ray examinations. Thorough consideration of radiation protection based on optimized equipment also includes the protection of relatives and other children in the PICU room. Ultrasound is an expanding imaging modality adjunct or as alternative to conventional X-ray examinations, which allows the generation of functional information (color-coded duplex, elastography). Fluoroscopy, computed tomography, and magnetic resonance imaging are available as advanced diagnostic modalities in special circumstances, but require transportation of the patient.


Assuntos
Diagnóstico por Imagem , Unidades de Terapia Intensiva Pediátrica , Adolescente , Criança , Pré-Escolar , Feminino , Fluoroscopia , Humanos , Interpretação de Imagem Assistida por Computador , Lactente , Recém-Nascido , Doenças do Prematuro/diagnóstico , Unidades de Terapia Intensiva Neonatal , Imageamento por Ressonância Magnética , Masculino , Sistemas Automatizados de Assistência Junto ao Leito , Prognóstico , Proteção Radiológica , Radiografia , Radiografia Torácica , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia
13.
Transfus Apher Sci ; 45(1): 45-51, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21715229

RESUMO

Several miniaturized high throughput technologies have been developed in the last decade, primarily to study genomic structures and gene expression patterns under various conditions. At the same time, the microarrays, biosensors, integrated microfluidic lab-on-a-chip devices, next generation sequencing or digital PCR are gradually finding their diagnostic applications, although their suitability for specialised diagnostic fields has still to be assessed. In this review we discuss the potential applications of the new technologies to blood testing.


Assuntos
Transfusão de Sangue/instrumentação , Miniaturização/instrumentação , Técnicas Biossensoriais/instrumentação , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Tecnologia
14.
Opt Express ; 19(5): 4421-7, 2011 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-21369273

RESUMO

In this paper we describe a high power narrow-band amplified spontaneous emission (ASE) light source at 1030 nm center wavelength generated in an Yb-doped fiber-based experimental setup. By cutting a small region out of a broadband ASE spectrum using two fiber Bragg gratings a strongly constrained bandwidth of 12±2 pm (3.5±0.6 GHz) is formed. A two-stage high power fiber amplifier system is used to boost the output power up to 697 W with a measured beam quality of M2≤1.34. In an additional experiment we demonstrate a stimulated Brillouin scattering (SBS) suppression of at least 17 dB (theoretically predicted ~20 dB), which is only limited by the dynamic range of the measurement and not by the onset of SBS when using the described light source. The presented narrow-band ASE source could be of great interest for brightness scaling applications by beam combination, where SBS is known as a limiting factor.


Assuntos
Amplificadores Eletrônicos , Tecnologia de Fibra Óptica/instrumentação , Lasers , Refratometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento
15.
Int J Obes (Lond) ; 35(9): 1141-53, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21266947

RESUMO

OBJECTIVES: Beside having roles in energy homeostasis and endocrine modulation, adipose tissue (AT) is now considered a promising source of mesenchymal stromal cells (adipose-derived stromal cells or ASCs) for regenerative medicine. Despite numerous studies on cultured ASCs, native human ASCs are rarely investigated. Indeed, the phenotype of ASCs in their native state, their localization within AT and comparison with bone marrow-derived mesenchymal stromal cells (BM-MSCs) has been poorly investigated. DESIGN: To address these issues, the stroma vascular fraction (SVF) of human AT was extracted and native cell subtypes were isolated by immunoselection to study their clonogenic potential in culture. Immunohistology on samples of human AT in combination with reconstruction of confocal sections were performed in order to localize ASCs. RESULTS: Compared with BM-MNCs, all native ASCs were found in the CD34(+) cell fraction of the AT-SVF. Native ASCs expressed classical mesenchymal markers described for BM-MSCs. Interestingly, CD34 expression decreased during ASC cell culture and was negatively correlated with cell proliferation rate. Immunohistological analysis revealed that native ASCs exhibited specific morphological features with protrusions. They were found scattered in AT stroma and did not express in vivo pericytic markers such as NG2, CD140b or alpha-smooth muscle actin, which appeared during the culture process. Finally, ASCs spontaneous commitment to adipocytic lineage was enhanced in AT from obese humans. CONCLUSIONS: The use of complementary methodological approaches to study native human ASCs revealed their immunophenotype, their specific morphology, their location within AT and their stemness. Furthermore, our data strongly suggest that human ASCs participate in adipogenesis during AT development.


Assuntos
Adipogenia , Tecido Adiposo/citologia , Diferenciação Celular/fisiologia , Células-Tronco Mesenquimais , Obesidade , Células Estromais , Adipogenia/genética , Adulto , Biomarcadores , Diferenciação Celular/genética , Células Cultivadas , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Células-Tronco Mesenquimais/citologia , Obesidade/genética , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/citologia
16.
Rheumatol Int ; 31(10): 1315-20, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20383509

RESUMO

Hypophosphatasia (HPP) is a rare inborn error of bone metabolism caused by various defects in the gene coding for the tissue-nonspecific alkaline phosphatase (TNSAP). It results in a reduced activity of the TNSAP and elevated concentrations of its substrates, including inorganic pyrophosphate. Clinical features of HPP include defective bone mineralisation with bone deformities, fractures and chronic non-bacterial osteomyelitis. Renal damage due to calcification, craniosynostosis and dental abnormalities with premature loss of dentition are further complications. Until now, detailed descriptions of whole-body magnetic resonance imaging (WB-MRI) in HPP do not exist. Here, we analysed WB-MRIs of 4 children with the childhood form of HPP. Deformities and defects of the long bones could be seen. All patients showed radiological lesions in the metaphyses of the long bones predominantly in the lower extremities being consistent with hyperaemia and oedema. Differential diagnosis includes an inflammatory process being active in these locations.


Assuntos
Hipofosfatasia/diagnóstico , Imageamento por Ressonância Magnética/métodos , Imagem Corporal Total/métodos , Calcinose/diagnóstico , Calcinose/genética , Calcinose/patologia , Pré-Escolar , Feminino , Humanos , Hipofosfatasia/genética , Hipofosfatasia/patologia , Lactente , Masculino , Osteomielite/diagnóstico , Osteomielite/patologia
17.
J Hum Hypertens ; 25(4): 256-61, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20463749

RESUMO

Hypertension is associated with an increased risk of cognitive decline, which is generally regarded as a consequence of advanced cerebral atherosclerosis. Many hypertensive patients, however, suffer from cognitive decline long before they have any signs of cerebrovascular disease. Therefore, this study examines direct effects of blood pressure on neurotransmitter status in the hippocampus, a vulnerable cerebral structure relevant for memory consolidation. Absolute glutamate concentration and N-acetylaspartate (NAA) concentration as an alternative marker of neuronal integrity were determined in the hippocampus and the cerebral cortex (anterior cingulate cortex; ACC) by 3-T proton magnetic resonance spectroscopy in 16 probands without any history of cerebrovascular disease. Memory function was tested by the auditory verbal learning test (AVLT) and the rivermead behavioural memory test (RBMT). Arterial stiffness was assessed by augmentation index (AI). Mean arterial pressure showed a significant negative age-adjusted correlation to absolute glutamate concentrations in the hippocampus (R=-0.655, P=0.011), but not in the ACC. There was no significant correlation of mean arterial pressure and NAA in either hippocampus or ACC. AI did not affect hippocampal glutamate. Moreover, there was a significant negative correlation between mean arterial pressure and AVLT (r=-0.558, P=0.025) and RBMT score (r=-0.555, P=0.026). There is an inverse relation between blood pressure and the concentration of hippocampal glutamate. Glutamate is essential for long-term potentiation, the neurobiological correlate for memory formation in the hippocampus. Thus, hypertension-associated cognitive decline may not only be mediated by structural atherosclerotic wall changes, but also by functional changes in neurotransmission.


Assuntos
Pressão Sanguínea , Transtornos Cognitivos/etiologia , Cognição , Ácido Glutâmico/metabolismo , Hipocampo/fisiopatologia , Hipertensão/fisiopatologia , Memória , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/psicologia , Feminino , Alemanha , Giro do Cíngulo/metabolismo , Giro do Cíngulo/fisiopatologia , Hipocampo/metabolismo , Humanos , Hipertensão/complicações , Hipertensão/metabolismo , Hipertensão/psicologia , Modelos Lineares , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto Jovem
18.
Tree Physiol ; 30(6): 689-704, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20453002

RESUMO

The periodic production of large seed crops by trees (masting) and its interaction with stem growth has long been the objective of tree physiology research. However, very little is known about the effects of masting on stem growth and total net primary productivity (NPP) at the stand scale. This study was conducted in an old-growth, mixed deciduous forest dominated by Fagus sylvatica (L.) and covers the period from 2003 to 2007, which comprised wet, dry and regular years as well as two masts of Fagus and one mast of the co-dominant tree species Fraxinus excelsior (L.) and Acer pseudoplatanus (L.). We combined analyses of weather conditions and stem growth at the tree level (inter- and intra-annual) with fruit, stem and leaf production, and estimates of total NPP at the stand level. Finally, we compared the annual demand of carbon for biomass production with net canopy assimilation (NCA), derived from eddy covariance flux measurements, chamber measurements and modelling. Annual stem growth of Fagus was most favoured by warm periods in spring and that of Fraxinus by high precipitation in June. For stem growth of Acer and for fruit production, no significant relationships with mean weather conditions were found. Intra-annual stem growth of all species was strongly reduced when the relative plant-available water in soil dropped below a threshold of about 60% between May and July. The inter-annual variations of NCA, total NPP and leaf NPP at the stand level were low (mean values 1313, 662 and 168 g C m(-2) year(-1), respectively), while wood and fruit production varied more and contrarily (wood: 169-241 g C m(-2) year(-1); fruits: 21-142 g C m(-2) year(-1)). In all years, an annual surplus of newly assimilated carbon was calculated (on average 100 g C m(-2) year(-1)). The results suggest that stem growth is generally not limited by insufficient carbon resources; only in mast years a short-term carbon shortage may occur in spring. In contrast to common assumption, stem growth alone is not a sufficient proxy for total biomass production or the control of carbon sequestration by weather extremes.


Assuntos
Clima , Fagus/crescimento & desenvolvimento , Caules de Planta/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Fraxinus/anatomia & histologia , Fraxinus/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Estações do Ano , Solo , Árvores/anatomia & histologia , Tempo (Meteorologia)
20.
Opt Lett ; 34(10): 1567-9, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19448823

RESUMO

We report on spectral combination of four high repetition rate 5 ns pulsed Yb-doped fiber amplifiers at 1 microm wavelength. The output beam is spatially and temporally superposed by use of an all-reflective diffraction grating. 1.1 kW average power and 220 microJ pulse energy were extracted with a combining efficiency of 99%.

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