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1.
Environ Geochem Health ; 46(6): 190, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695943

RESUMO

A magnetic nanocomposite of hydroxyapatite and biomass (HAp-CM) was synthesized through a combined ultrasonic and hydrothermal method, aiming for efficient adsorption of arsenic (As) and fluoride (F-) from drinking water in natural environments. The characterization of HAp-CM was carried out using TG, FTIR, XRD, SEM, SEM-EDS, and TEM techniques, along with the determination of pHpzc charge. FTIR analysis suggested that coordinating links are the main interactions that allow the formation of the nanocomposite. XRD data indicated that the crystalline structure of the constituent materials remained unaffected during the formation of HAp-CM. SEM-EDS analysis revelated a Ca/P molar ratio of 1.78. Adsorption assays conducted in batches demonstrated that As and F- followed a PSO kinetic model. Furthermore, As adsorption fitting well to the Langmuir model, while F- adsorption could be explained by both Langmuir and Freundlich models. The maximum adsorption capacity of HAp-CM was found to be 5.0 mg g-1 for As and 10.2 mg g-1 for F-. The influence of sorbent dosage, pH, and the presence of coexisting species on adsorption capacity was explored. The pH significantly affected the nanocomposite's efficiency in removing both pollutants. The presence of various coexisting species had different effects on F- removal efficiency, while As adsorption efficiency was generally enhanced, except in the case of PO43-. The competitive adsorption between F- and As on HAp-CM was also examined. The achieved results demonstrate that HAp-CM has great potential for use in a natural environment, particularly in groundwater remediation as a preliminary treatment for water consumption.


Assuntos
Arsênio , Durapatita , Fluoretos , Nanocompostos , Poluentes Químicos da Água , Purificação da Água , Fluoretos/química , Adsorção , Nanocompostos/química , Durapatita/química , Poluentes Químicos da Água/química , Arsênio/química , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Biomassa , Cinética , Água Potável/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Brain Sci ; 14(2)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38391708

RESUMO

BACKGROUND: The goal of this study was to investigate whether the combination of semantic feature analysis (SFA) and transcranial direct current stimulation (tDCS) is effective in treating word retrieval in the semantic variant of primary progressive aphasia (svPPA) and how long the potential effects last. METHODS: A 56-year-old woman diagnosed with frontotemporal dementia (FTD) and svPPA participated in this longitudinal single-subject design. A total of four 2-week stimulation phases were conducted over a 14-month period, each of which was started depending on the participant's language performance. Follow-up testing was conducted shortly after the stimulation period, approximately 2 weeks, and approximately 4 weeks thereafter. RESULTS: Significant improvement in word retrieval occurred after SFA and tDCS therapy. Two weeks after the end of each stimulation phase, approx. 80% of the trained words could be named correctly. For the untrained words, also significantly more words were correctly named at follow-ups compared to the baseline. Furthermore, the Boston Naming Test (BNT) demonstrated a significant increase in naming performance and showed that phonological cues facilitated word retrieval compared to semantic cues. CONCLUSION: The combination of SFA and tDCS was able to counteract the expected language deterioration of a participant with svPPA. This effect increased until approximately 2 weeks after each intervention. In addition, a generalization of the effect to untrained words was shown.

3.
NPJ Parkinsons Dis ; 9(1): 162, 2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38071194

RESUMO

Progressive supranuclear palsy (PSP) is an atypical Parkinsonian disorder which results in deterioration of motor and cognitive skills, including language disorders such as impaired word retrieval. While there is evidence of successful use of tDCS to improve word fluency in PSP, little is known about the effectiveness of brain stimulation for word retrieval in sentence context. Therefore, we investigated whether tDCS reduces sentence completion time in PSP patients. In this sham-controlled, triple-blinded crossover study, anodal tDCS (atDCS) was applied over the left Broca's area at 2 mA for 20 min (n = 23). In contrast to patients with multiple system atrophy (MSA), also an atypical Parkinsonian disorder, and healthy elderlies, sentence completion improved in PSP patients when tDCS was applied. The improvement in word fluency reported in previous studies using other electrode positions was not replicated. By using atDCS of the left Broca's area, we were able to demonstrate a difference between the two movement disorders. The obtained insight could be helpful to improve language therapy of these disorders.

4.
Tijdschr Psychiatr ; 65(2): 107-112, 2023.
Artigo em Holandês | MEDLINE | ID: mdl-36912056

RESUMO

BACKGROUND: Clozapine is the most effective treatment for people with treatment-resistant schizophrenia. However, it is prescribed less often than guidelines indicate. AIM: To personalize clozapine treatment, we investigated the efficacy of clozapine as first- or second-line treatment and investigated whether there are factors that were associated with efficacy and side effects. METHOD: We collected a unique cohort of over 800 clozapine users diagnosed with a schizophrenia spectrum disorder. We meta-analyzed factors that were associated with response during clozapine treatment. Additionally, we conducted genetic association analyses to investigate the relations between side effects and symptom severity during clozapinetreatment. RESULTS: From our meta-analyses, we found that clozapine was more effective when used as a first- or second-line treatment. Furthermore, we found that younger age, less negative symptoms and the paranoid subtype of schizophreniawere associated with a better clozapine response. Several specific locations on genes (loci) were associated with clozapine-induced agranulocytosis and neutropenia, while polygenic risk scores were associated with symptom severity. CONCLUSION: We found that clozapine could be effective earlier in treatment and identified factors that could aid the prediction of< response to clozapine treatment in the future. These finding could contribute to the start of a personalized clozapine treatment.


Assuntos
Antipsicóticos , Clozapina , Neutropenia , Esquizofrenia , Humanos , Antipsicóticos/uso terapêutico , Clozapina/efeitos adversos , Neutropenia/induzido quimicamente , Neutropenia/tratamento farmacológico , Medicina de Precisão , Esquizofrenia/tratamento farmacológico
5.
Front Aging ; 4: 1171133, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38414493

RESUMO

Introduction: In addition to age-related changes in language, hemispheric lateralization of language functions steadily declines with age. Also, performance on word fluency tasks declines and is sensitive to the expression of dementia-related changes. The aim of this study is to evaluate the effect of anodal tDCS combined with a word fluency training on language lateralization and word fluency performance in healthy elderly subjects and in persons with mild cognitive impairment (MCI). Methods: The effect of anodal tDCS over the left inferio frontal gyrus (IFG) was measured in a group of healthy elderly up to the age of 67 years (YG, Ø = 63.9 ± 3.02), a group of healthy elderly aged 68 years and older (OG, Ø = 78.1, ± 4.85), and a group of patients with MCI (Ø = 81.18, ± 7.35) by comparing performance in phonological and semantic word fluency tasks before and after 3 days of tDCS. Half of the experimental participants received sham stimulation. In addition, language lateralization was determined using a lateralization index (LI) measured with functional transcranial Doppler sonography (fTCD) before and after the stimulation period. Results: Anodal tDCS was associated with significantly higher scores in phonological but not semantic word fluency in both YG and OG. In MCI patients, no difference was measured between the tDCS and sham groups in either word fluency task. fTCD showed significantly increased left lateralization in all three groups after the training phase. However, this effect was independent of tDCS and the degree of lateralization could not be predicted by word fluency performance in any of the groups. Discussion: Phonological word fluency can be increased with atDCS in healthy elderly people by stimulating the IFG in a 3-day training. When cognitive decline has reached a certain stage, as is the case with MCI, this paradigm does not seem to be effective enough.

6.
Tijdschr Psychiatr ; 64(5): 266-272, 2022.
Artigo em Holandês | MEDLINE | ID: mdl-35735035

RESUMO

BACKGROUND: Insights from psychiatric genetics research and large international psychiatric genetics consortia are promising but still remain outside the realm of clinical practice.
AIM: To provide an overview of developments in the field of psychiatric genetics; and to offer guidance for health professionals how to assess and manage clinical implications of these developments.
METHOD: In this review, we address: recent developments in psychiatric genetics, with a focus on polygenic risk scores (PRS); ethical dilemmas associated with clinical application of PRS; and basic principles of genetic counseling for psychiatric disorders.
RESULTS: PRS are not yet ready for implementation in clinical practice because of limited predictive value and poor generalizability. In addition, it is still unclear how genetic risk and PRS can be communicated clearly to patients and families.
CONCLUSION: Advances in psychiatric genetics and increased availability of genetic risk scores may lead to questions from patients and families coping with psychiatric illness. These questions may be best addressed using psychiatric genetic counseling techniques. We recommend that psychiatrists have some basic knowledge of psychiatric genetics and know how to refer their patients to a clinical geneticist. Implementing a psychiatric genetics theme in training and education may be helpful.
.


Assuntos
Transtornos Mentais , Psiquiatria , Adaptação Psicológica , Humanos , Transtornos Mentais/genética , Transtornos Mentais/psicologia , Psiquiatria/educação , Fatores de Risco
7.
Tijdschr Psychiatr ; 64(5): 278-285, 2022.
Artigo em Holandês | MEDLINE | ID: mdl-35735037

RESUMO

BACKGROUND: In recent years, technological advances have led to the identification of numerous genetic variations that are associated with psychiatric symptoms. Establishing a genetic cause may provide patients and family members with an explanation for the problems and in specific cases allows targeted treatment of psychiatric and somatic (co)morbidity. At present, patients with psychiatric disorders are rarely referred for genetic testing. AIM: To provide an overview of literature and (inter)national guidelines in the field of genetic testing for patients with psychiatric disorder, and to present guidance on indications for genetic testing in clinical practice. METHOD: A systematic search was conducted in PubMed and Embase focusing on articles with recommendations on genetic testing in psychiatric disorders. In addition, national and international guidelines on genetic testing in psychiatry were studied. The main findings were summarized in an infographic. RESULTS: Based on the current literature and (inter)national guidelines, patients with (comorbid) intellectual disability should always be referred to a clinical geneticist. Psychiatrists should consider genetic testing in patients with other psychiatric disorders if there are ‘red flags’ such as a positive family history, congenital abnormalities, developmental delay, dysmorphic features, movement disorders or cognitive decline. Psychiatrists may request genetic testing themselves or refer patients to clinical geneticists. CONCLUSION: Psychiatric disorders may be underpinned by a genetic anomaly, particularly in patients presenting with psychiatric as well as somatic symptomatology. Psychiatrists should recognize symptoms and warning signs indicative of an underlying genetic abnormality, and know when to refer their patients for genetic testing.


Assuntos
Transtornos Mentais , Psiquiatria , Comorbidade , Testes Genéticos , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/genética , Transtornos Mentais/terapia
8.
J Integr Neurosci ; 21(2): 64, 2022 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35364652

RESUMO

Functional transcranial Doppler sonography (fTCD) is a time- and cost-effective, non-invasive approach to determining real time hemispheric lateralization and is well-suited for repetitive study designs comprising multiple days. To date, no study has examined the reproducibility of the direction and degree (strength) of lateralization during word fluency (WF) over multiple, consecutive sessions within a single person, although there are many studies of lateralization during language processing. Moreover, there is conflicting evidence as to whether there is a relationship between the degree of laterality and the word fluency performance. In this study, one right-handed male (aged 24 years) completed a total of seven examination sessions in the time span of 10 days. Each session comprised multiple phonological and semantic WF tasks. The maximum difference of relative cerebral blood flow velocity (CBFV) changes between the left and right middle cerebral artery (MCA) during WF was defined as the Lateralization Index (LI). The word-fluency performance and the LIs were used in a linear regression model to detect relative changes in the direction and degree of lateralization during repetitive WF tasks. The reproducibility of the direction of language-related lateralization is very stable over multiple sessions within this single person and the processed LIs were left-lateralized in every session for both WF tasks. In addition, performance during phonological WF could significantly predict the variability in the degree of lateralization. This result could not be confirmed for the semantic WF task. The results of this pilot study support the usage of fTCD as a reliable method for examining lateralization patterns, especially in longitudinal study designs. They also provide evidence for the notion that performance in WF tasks can be related to the degree of lateralization, at least intra-individually.


Assuntos
Lateralidade Funcional , Ultrassonografia Doppler Transcraniana , Adulto , Lateralidade Funcional/fisiologia , Humanos , Estudos Longitudinais , Masculino , Projetos Piloto , Reprodutibilidade dos Testes , Ultrassonografia Doppler Transcraniana/métodos , Adulto Jovem
9.
Transl Psychiatry ; 12(1): 145, 2022 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-35393395

RESUMO

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia. However, response is highly variable and possible genetic underpinnings of this variability remain unknown. Here, we performed polygenic risk score (PRS) analyses to estimate the amount of variance in symptom severity among clozapine-treated patients explained by PRSs (R2) and examined the association between symptom severity and genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activity. Genome-wide association (GWA) analyses were performed to explore loci associated with symptom severity. A multicenter cohort of 804 patients (after quality control N = 684) with schizophrenia spectrum disorder treated with clozapine were cross-sectionally assessed using the Positive and Negative Syndrome Scale and/or the Clinical Global Impression-Severity (CGI-S) scale. GWA and PRS regression analyses were conducted. Genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activities were calculated. Schizophrenia-PRS was most significantly and positively associated with low symptom severity (p = 1.03 × 10-3; R2 = 1.85). Cross-disorder-PRS was also positively associated with lower CGI-S score (p = 0.01; R2 = 0.81). Compared to the lowest tertile, patients in the highest schizophrenia-PRS tertile had 1.94 times (p = 6.84×10-4) increased probability of low symptom severity. Higher genotype-predicted CYP2C19 enzyme activity was independently associated with lower symptom severity (p = 8.44×10-3). While no locus surpassed the genome-wide significance threshold, rs1923778 within NFIB showed a suggestive association (p = 3.78×10-7) with symptom severity. We show that high schizophrenia-PRS and genotype-predicted CYP2C19 enzyme activity are independently associated with lower symptom severity among individuals treated with clozapine. Our findings open avenues for future pharmacogenomic projects investigating the potential of PRS and genotype-predicted CYP-activity in schizophrenia.


Assuntos
Antipsicóticos , Clozapina , Citocromo P-450 CYP2C19 , Esquizofrenia , Antipsicóticos/uso terapêutico , Clozapina/uso terapêutico , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2D6/genética , Estudo de Associação Genômica Ampla , Humanos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/genética
10.
Nurs Rep ; 11(1): 175-186, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-34968322

RESUMO

Measuring health may refer to the measurement of general health status through measures of physical function, pain, social health, psychological aspects, and specific disease. Almost no evidence is available on the possible interaction of physiological measures and correlating emotional-affective states that are triggered by dealing with individual health-relevant issues and their specific processing modes. Public health research has long been concerned with the processing of health-related information. However, it is not yet clear which factors influence access and the handling of health-related information in detail. One way to close this research gap could be adopting methods from neurocognitive experiments to add psychophysiological data to existing approaches in health-related research. In this article, we present some of these methods and give a narrative overview and description of their usefulness for enlarged research in public health.

11.
Behav Sci (Basel) ; 11(12)2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34940097

RESUMO

Regarding the embodiment of language processing in adults, there is evidence of a close connection between sensorimotor brain areas and brain areas relevant to the processing of action verbs. This thesis is hotly debated and has therefore been thoroughly studied in adults. However, there are still questions concerning its development in children. The present study deals with the processing of action verbs in concrete and abstract sentences in 60 eleven-year-olds using a decision time paradigm. Sixty-five children mirrored arm movements or sat still and rated the semantic plausibility of sentences. The data of the current study suggest that eleven-year-olds are likely to misunderstand the meaning of action verbs in abstract contexts. Their decision times were faster and their error rates for action verbs in concrete sentences were lower. However, the gender of the children had a significant influence on the decision time and the number of errors, especially when processing abstract sentences. Females were more likely to benefit from an arm movement before the decision, while males were better if they sat still beforehand. Overall, children made quite a few errors when assessing the plausibility of sentences, but the female participants more often gave plausibility assessments that deviated from our expectations, especially when processing abstract sentences. It can be assumed that the embodiment of language processing plays some role in 11-year-old children, but is not yet as mature as it is in adults. Especially with regard to the processing of abstract language, the embodied system still has to change and mature in the course of child development.

12.
Tijdschr Psychiatr ; 63(4): 270-275, 2021.
Artigo em Holandês | MEDLINE | ID: mdl-33913142

RESUMO

BACKGROUND: To monitor the unique side effect pattern of clozapine, the Glasgow Antipsychotic Side-effect Scale for Clozapine (GASS-C) was developed in English and validated. This questionnaire was previously translated to Dutch, and revised, but not yet validated. AIM: The current study concerns the validation of the second revision of the GASS-C-NL-R2 for the Dutch language. METHOD: Two Spearman correlation tests were conducted to compare GASS-C-NL-R2 with the Dutch version of the Liverpool University Neuroleptic Side-Effect Rating Scale (LUNSERS) at two time p´oints. There was one week between these two time points. The test-retest reliability was determined using a Spearman correlation test and Cronbach's alpha on the GASS-C-NL-R2 between the two time points. In addition, a factor analysis was performed. RESULTS: Spearman's correlation coefficient between the GASS-C-NL-R2 and the LUNSERS was 0.830 (p < 0.001, n = 72) at the first time point and 0.684 (p < 0.001, n = 50) at the second time point. GASS-C-NL-R2 also had a strong test-retest reliability: Spearman's correlation coefficient was 0.680 (p < 0.001; n = 46), and Cronbach's alpha was 0.847, n = 78. Factor analysis showed that all questions were relevant. CONCLUSION: The current study shows that GASS-C-NL-R2 is a valid and reliable questionnaire to monitor side effects related to clozapine with a relatively high prevalence. Future studies should focus on the practical utility of GASS-C-NL-R2 with a larger sample size.


Assuntos
Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Inquéritos e Questionários/normas , Humanos , Idioma , Reprodutibilidade dos Testes , Tradução
13.
Ned Tijdschr Tandheelkd ; 128(2): 113-117, 2021 Feb.
Artigo em Holandês | MEDLINE | ID: mdl-33605261

RESUMO

As far as we know, very little has been published in dental literature on how patients' complaints about their dentist's treatment are assessed and what methods are used to try and resolve these complaints with the accused dentist. On the basis of 2 cases, a successful strategy of dental advisers is outlined. How they developed a strategy to resolve the complaint satisfactorily, drawing on knowledge of the use of conversation techniques, with the accused dentist is emphasised. Early on in the conversation, it is particularly important for advisers to understand and sense the often quite emotional state of mind of the dentist. Thereafter, an account of the facts can be formulated and a strategy can be developed for assessing and possibly resolving the patient's complaint.


Assuntos
Relações Dentista-Paciente , Emoções , Comunicação , Humanos
14.
Neurosci Biobehav Rev ; 121: 119-127, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33301779

RESUMO

Polygenic risk scores (PRS) may aid in the identification of individuals at-risk for psychiatric disorders, treatment optimization, and increase in prognostic accuracy. PRS may also add significant value to genetic counseling. Thus far, integration of PRSs in genetic counseling sessions remains problematic because of uncertainties in risk prediction and other concerns. Here, we review the current utility of PRSs in the context of clinical psychiatry. By comprehensively appraising the literature in other fields of medicine including breast cancer, Alzheimer's Disease, and cardiovascular disease, we outline several lessons learned that could be applied to future studies and may thus benefit the incorporation of PRS in psychiatric genetic counseling. These include integrating PRS with environmental factors (e.g. lifestyle), setting up large-scale studies, and applying reproducible methods allowing for cross-validation between cohorts. We conclude that psychiatry may benefit from experiences in these fields. PRS may in future have a role in genetic counseling in clinical psychiatric practice, by advancing prevention strategies and treatment decision-making, thus promoting quality of life for (potentially) affected individuals.


Assuntos
Aconselhamento Genético , Psiquiatria , Predisposição Genética para Doença , Humanos , Herança Multifatorial , Qualidade de Vida , Fatores de Risco
15.
BMC Psychiatry ; 20(1): 568, 2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33246443

RESUMO

BACKGROUND: Clozapine is an atypical antipsychotic proven to be superior in the treatment of treatment-resistant schizophrenia. Myocarditis is a rare, but well-known complication of treatment with clozapine. Only few cases have been reported in which nausea and vomiting were prominent symptoms. This is the first described report in which nausea and vomiting were the only presenting symptoms of clozapine-induced myocarditis. CASE PRESENTATION: We report a case of a 58-year-old woman, suffering from schizoaffective disorder, who is being treated with clozapine. Two weeks after initiation of clozapine, she developed nausea and vomiting, in absence of any other clinical symptoms. Laboratory examination and magnetic resonance imaging confirmed the diagnosis of clozapine-induced myocarditis. Clozapine was discontinued and the patient recovered fully. CONCLUSIONS: This case emphasizes the importance of recognizing myocarditis as a cause of isolated nausea and vomiting in patients treated with clozapine. Early recognition improves clinical outcome and reduces mortality.


Assuntos
Antipsicóticos , Clozapina , Miocardite , Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Miocardite/induzido quimicamente , Miocardite/diagnóstico , Náusea , Vômito/induzido quimicamente
16.
Soc Sci Med ; 183: 80-87, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28475902

RESUMO

The Extending Working Lives (EWL) agenda seeks to sustain employment up to and beyond traditional retirement ages. This study examined the potential role of childhood factors in shaping labour force participation and exit among older adults, with a view to informing proactive interventions early in the life-course to enhance individuals' future capacity for extending their working lives. Childhood adversity and socioeconomic disadvantage have previously been linked to ill-health across the life-span and sickness benefit in early adulthood. This study builds upon previous research by examining associations between childhood adversity and self-reported labour force participation among older adults (aged 55). Data was from the National Child Development Study - a prospective cohort of all English, Scottish, & Welsh births in one week in 1958. There was evidence for associations between childhood adversity and increased risk of permanent sickness at 55 years - which were largely sustained after adjustment for educational disengagement and adulthood factors (mental/physical health, qualifications, socioeconomic disadvantage). Specifically, children who were abused or neglected were more likely to be permanently sick at 55 years. In addition, among males, those in care, those experiencing illness in the home, and those experiencing two or more childhood adversities were more likely to be permanently sick at 55 years. Childhood factors were also associated with part-time employment and retirement at 55 years. Severe childhood adversities may represent important distal predictors of labour force exit at 55 years, particularly via permanent sickness. Notably, some adversities show associations among males only, which may inform interventions designed to extend working lives.


Assuntos
Maus-Tratos Infantis/psicologia , Saúde da Criança/normas , Emprego/psicologia , Aposentadoria/psicologia , Classe Social , Criança , Maus-Tratos Infantis/reabilitação , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Aposentadoria/normas , Reino Unido , Engajamento no Trabalho , Recursos Humanos
17.
Mater Sci Eng C Mater Biol Appl ; 74: 443-450, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28254315

RESUMO

In this study, one-step co-precipitation method was conveniently adapted to obtain novel nanomaterials based on Gum Arabic and magnetite. Two synthesis procedures were evaluated: one employing the solid biopolymer in the co-precipitation media; a second using an aqueous solution of the polysaccharide. An exhaustive characterization of both formulations was performed using several specific techniques. The obtained data confirmed the successful incorporation of the gum Arabic on the magnetic core. Values of hydrodynamic diameters, measured by dynamic light scattering, in aqueous dispersions were about 70-80nm, while sizes lower than 20nm were registered by TEM microscopy. Surface charge of gum Arabic coated magnetic nanoparticles was significantly different from the corresponding to raw materials (magnetite and GA). This fact confirmed the formation of hybrid nanosystems with novel and specific properties. The potential utility of these materials was tested regarding to magnetic hyperthermia therapy under radiofrequency fields. Magnetocalorimetric measurements were performed in a wide range of field amplitude and frequency. Specific absorption rate of 218W/gFe was determined at field frequency of 260kHz and amplitude of 52kA/m. These results demonstrate their viability to be applied in tumor ablation treatments. Using the linear response theory and restricting field parameters to the accepted biomedical window, maximum useful value of 74w/gFe is predicted at 417kHz and 12kA/m.


Assuntos
Goma Arábica/química , Magnetismo , Nanoestruturas/química , Difusão Dinâmica da Luz , Hipertermia Induzida , Nanopartículas de Magnetita/química , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
18.
BMC Anesthesiol ; 17(1): 42, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-28288587

RESUMO

BACKGROUND: A relatively new uncalibrated arterial pressure waveform cardiac output (CO) measurement technique is the Pulsioflex-ProAQT® system. Aim of this study was to validate this system in cardiac surgery patients with a specific focus on the evaluation of a difference in the radial versus the femoral arterial access, the value of the auto-calibration modus and the ability to show fluid-induced changes. METHODS: In twenty-five patients scheduled for ascending aorta, aortic arch replacement, or both we measured CO simultaneously by transpulmonary thermodilution (COtd) and by using the ProAQT® system connected to the radial (COpR), as well as the femoral artery catheter (COpF). Hemodynamic data were assessed at predefined time points; from incision until 16 h after ICU admission. RESULTS: In total 175 (radial) and 179 (femoral) pairs of CO measurement were collected. The accuracy of COpR/COpF was evaluated showing a mean bias of -0.31 L/min (±2.9 L/min) and -0.57 L/min (± 2.8 L/min) with percentage errors of 49 and 46% respectively. Trending ability of the ProAQT® device was evaluated; the four quadrant concordance rates in the radial and femoral artery were 74 and 75% and improved to 77 and 85% after auto-calibration. The mean angular biases in the radial and femoral artery were 6.4° and 6.0° and improved to 5° and 3.3° after auto-calibration. The polar concordance rates in the radial and femoral artery were 65 and 70% and improved to 76 and 84% after auto-calibration. Considering the fluid-induced changes in stroke volume(SV), the coefficient of correlation between the changes in SVtd and SVp was 0.57 (p < 0.01) in the radial artery and 0.60 (p < 0.01) in the femoral artery. CONCLUSIONS: The ProAQT® system can be of additional value if the clinician wants to determine fluid responsiveness in cardiac surgery patients. However, the ProAQT® system provided inaccurate CO measurements compared to transpulmonary thermodilution. The trending ability was poor for COpR but moderate for COpF. Auto-calibration of the system did not improve accuracy of CO measurements nor did it improve the prediction of fluid responsiveness. However, the trending ability was improved by auto-calibration, possibly by correcting a drift over a longer time period.


Assuntos
Débito Cardíaco/fisiologia , Procedimentos Cirúrgicos Cardíacos , Artéria Femoral/fisiologia , Monitorização Intraoperatória/instrumentação , Artéria Radial/fisiologia , Idoso , Pressão Sanguínea/fisiologia , Catéteres , Feminino , Humanos , Masculino , Estudos Prospectivos , Termodiluição
19.
Brain Lang ; 168: 95-105, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28189047

RESUMO

Brain oscillations in the α- and ß-range become suppressed during motor processing and motor imagery. It has recently been discussed that such power changes also occur during action language processing. In our study, we compared ß2-oscillations (16-25Hz) during the observation of prototypical arm movements (revealed via motion tracking) as well as during semantic processing of concrete and abstract sentences containing arm-related action verbs. Whereas we did find a strong desynchronization in the ß2-range during action observation, the processing of action sentences evoked a rather weak desynchronization. However, this desynchronization occurred for action verbs in both concrete and abstract contexts. These results might indicate a tendency for abstract action language to be processed similar to concrete action language rather than abstract sentences. The oscillation patterns reflect the close relationship between language comprehension and motor functions - one of the core claims of current theories on embodied cognition.


Assuntos
Ritmo beta/fisiologia , Compreensão/fisiologia , Eletroencefalografia/métodos , Idioma , Desempenho Psicomotor/fisiologia , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico , Feminino , Humanos , Masculino , Semântica , Adulto Jovem
20.
Cogn Sci ; 41(5): 1328-1349, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27882587

RESUMO

In a behavioral study we analyzed the influence of visual action primes on abstract action sentence processing. We thereby aimed at investigating mental motor involvement during processes of meaning constitution of action verbs in abstract contexts. In the first experiment, participants executed either congruous or incongruous movements parallel to a video prime. In the second experiment, we added a no-movement condition. After the execution of the movement, participants rendered a sensibility judgment on action sentence targets. It was expected that congruous movements would facilitate both concrete and abstract action sentence comprehension in comparison to the incongruous and the no-movement condition. Results in Experiment 1 showed a concreteness effect but no effect of motor priming. Experiment 2 revealed a concreteness effect as well as an interaction effect of the sentence and the movement condition. The findings indicate an involvement of motor processes in abstract action language processing on a behavioral level.


Assuntos
Idioma , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Adulto , Compreensão/fisiologia , Feminino , Humanos , Julgamento/fisiologia , Masculino , Adulto Jovem
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