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1.
Disabil Rehabil ; 45(15): 2507-2516, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35815498

RESUMO

PURPOSE: To assess the psychosocial outcomes of facial weakness in facioscapulohumeral muscular dystrophy (FSHD). MATERIALS AND METHODS: A cross-sectional survey study. The severity of facial weakness was assessed by patients (self-reported degree of facial weakness) and by physicians (part I FSHD clinical score). Questionnaires on facial function, psychosocial well-being, functioning, pain, and fatigue were completed. Regression analyses were performed to explain variance in psychosocial outcomes by demographic and disease variables. RESULTS: One hundred and thirty-eight patients participated. They reported mild to moderate psychological distress, no to mild fear of negative evaluation, and moderate to good social functioning. However, patients with severe self-reported facial weakness scored lower in social functioning. Patients with more facial dysfunction experienced more fear of negative evaluation and lower social functioning. Furthermore, younger age, presence of pain, fatigue, walking difficulty, and current or previous psychological support were associated with lower psychosocial outcomes. Overall, patients report moderate to good psychosocial functioning in this study. The factors contributing to lower psychosocial functioning are diverse. CONCLUSIONS: A multidisciplinary, personalized approach, focusing on coping with physical, emotional, and social consequences of FSHD is supposed to be helpful. Further research is needed to assess the psychosocial outcomes of facial weakness in younger patients.Implications for rehabilitationResearch on the psychosocial consequences of facial weakness in facioscapulohumeral muscular dystrophy (FSHD) is limited.Patients with FSHD experience mild to moderate psychosocial distress, partly due to overall disease severity, such as reduced mobility, and partly due to facial weakness and reduced facial function.Self-reported degree of facial weakness and facial dysfunction were related to lower psychosocial outcomes (social functioning, fear of negative evaluation, and psychological distress).Physician-reported degree of facial weakness was not related to psychosocial outcomes, suggesting an absence of a strong correlation between observed facial weakness and experienced disease burden in this study.This calls for a multidisciplinary, personalized approach with a focus on coping with physical, emotional, and social consequences of FSHD.


Assuntos
Distrofia Muscular Facioescapuloumeral , Humanos , Estudos Transversais , Dor/complicações , Análise de Regressão , Fadiga Muscular
2.
Support Care Cancer ; 30(2): 1797-1806, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34599663

RESUMO

PURPOSE: To investigate the prevalence of adjustment disorder (AD) among cancer patients and the acceptance of psychological treatment, in relation to sociodemographic, clinical, and psychological factors. METHODS: Breast, prostate, and head and neck cancer patients of all stages and treatment modalities (N = 200) participated in this observational study. Patients completed the Hospital Anxiety and Depression Scale, Checklist Individual Strength, Distress Thermometer and problem list. Patients with increased risk on AD based on these questionnaires were scheduled for a diagnostic interview. Patients diagnosed with AD were invited to participate in a randomized controlled trial on the cost-effectiveness of psychological treatment. Participation in this trial was used as a proxy of acceptance of psychological treatment. Logistic regression analyses were used to investigate associated factors. RESULTS: The overall prevalence of AD was estimated at 13.1%. Sensitivity analyses showed prevalence rates of AD of 11.5%, 15.0%, and 23.5%. Acceptance of psychological treatment was estimated at 65%. AD was associated both with being employed (OR = 3.3, CI = 1.3-8.4) and having a shorter time since diagnosis (OR = 0.3, CI = 0.1-0.8). CONCLUSION: Taking sensitivity analysis into account, the prevalence of AD among cancer patients is estimated at 13 to 15%, and is related to being employed and having a shorter time since diagnosis. The majority of cancer patients with AD accept psychological treatment.


Assuntos
Transtornos de Adaptação , Neoplasias de Cabeça e Pescoço , Transtornos de Adaptação/epidemiologia , Transtornos de Adaptação/etiologia , Transtornos de Adaptação/terapia , Ansiedade , Análise Custo-Benefício , Depressão , Humanos , Masculino , Prevalência , Estresse Psicológico , Inquéritos e Questionários
3.
Br J Surg ; 108(8): 991-997, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-33837383

RESUMO

BACKGROUND: Bowel dysfunction after rectal cancer surgery is common, with some experiencing low anterior resection syndrome (LARS) is common after rectal cancer surgery. This study examined if transanal total mesorectal excision (TaTME) has a similar risk of LARS and altered quality of life (QoL) as patients who undergo low anterior resection (LAR). METHODS: Patients who underwent TaTME or traditionally approached total mesorectal excision in a prospective colorectal cancer cohort study (2014-2019) were propensity score matched in a 1 : 1 ratio. LARS and QoL scores were assessed before and after surgery with a primary endpoint of major LARS at 12 months analysed for possible association between factors by logistic regression. RESULTS: Of 61 TaTME and 317 LAR patients eligible, 55 from each group were propensity score matched. Higher LARS scores (30.6 versus 25.4, P = 0.010) and more major LARS (65 versus 42 per cent, P = 0.013; OR 2.64, 95 per cent c.i. 1.22 to 5.71) were reported after TaTME. Additionally, QoL score differences (body image, bowel frequency, and embarrassment) were worse in the TaTME group. CONCLUSIONS: TaTME may be associated with more severe bowel dysfunction than traditional approaches to rectal cancer.


Assuntos
Laparoscopia/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Protectomia/efeitos adversos , Pontuação de Propensão , Neoplasias Retais/cirurgia , Reto/cirurgia , Cirurgia Endoscópica Transanal/efeitos adversos , Feminino , Humanos , Incidência , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Protectomia/métodos , Estudos Prospectivos , Síndrome , Cirurgia Endoscópica Transanal/métodos
4.
Trials ; 22(1): 177, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648576

RESUMO

BACKGROUND: Mitochondrial disease is a rare, hereditary disease with a heterogeneous clinical presentation. However, fatigue is a common and burdensome complaint in children and adolescents with mitochondrial disease. No psychological intervention targeting fatigue exists for paediatric patients with a mitochondrial disease. We designed the PowerMe intervention, a blended cognitive behaviour therapy targeting fatigue in children and adolescents with mitochondrial disease. The aim of the intervention is to reduce perceived fatigue by targeting fatigue-related cognitions and behaviours. METHODS: A multiple baseline single case experiment will be conducted in five children (8-12 years old) and 5 adolescents (12-18 years old) with mitochondrial disease and severe fatigue. Patients will be included in the study for 33 weeks, answering weekly questions about the fatigue. Patients will be randomly assigned a baseline period of 5 to 9 weeks before starting the PowerMe intervention. The intervention consists of face-to-face and online sessions with a therapist and a website with information and assignments. The treatment will be tailored to the individual. Each patient will work on their personalized treatment plan focusing on personally relevant goals. The primary outcome is perceived fatigue. Secondary outcomes are quality of life, school presence and physical functioning. DISCUSSION: The results of the PowerMe study will provide information on the efficacy of a blended cognitive behaviour therapy on reducing perceived fatigue and its impact on daily life in children and adolescents with mitochondrial disease. Strengths and limitations of the study design are discussed. TRIAL REGISTRATION: Dutch Trial Register NTR 7675. Registered on 17 December 2018. Identifier https://www.trialregister.nl/trial/7433.


Assuntos
Terapia Cognitivo-Comportamental , Doenças Mitocondriais , Adolescente , Criança , Fadiga/diagnóstico , Fadiga/terapia , Humanos , Doenças Mitocondriais/diagnóstico , Doenças Mitocondriais/terapia , Qualidade de Vida , Projetos de Pesquisa
5.
Eur J Surg Oncol ; 46(10 Pt A): 1779-1788, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32571636

RESUMO

Follow-up after curative treatment for colorectal cancer (CRC) puts pressure on outpatient services due to the growing number of CRC survivors. The aim of this state-of-the-art review was to evaluate setting, manner and provider of follow-up. Moreover, perceptions of CRC survivors and health care providers regarding standard and alternative follow-up were examined. After a comprehensive literature search of the PubMed database, 69 articles were included reporting on CRC follow-up in the hospital, primary care and home setting. Hospital-based follow-up is most common and has been provided by surgeons, medical oncologists, and gastroenterologists, as well as nurses. Primary care-based follow-up has been provided by general practitioners or nurses. Even though most hospital- or primary care-based follow-up care requires patients to visit the clinic, telephone-based care has proven to be a feasible alternative. Most patients perceived follow-up as positive; valuing screening and detection for disease recurrence and appreciating support for physical and psychosocial symptoms. Hospital-based follow-up performed by the medical specialist or nurse is highly preferred by patients and health care providers. However, willingness of both patients and health care providers for alternative, primary care or remote follow-up exists. Nurse-led and GP-led follow-up have proven to be cost-effective alternatives compared to specialist-led follow-up. If proven safe and acceptable, remote follow-up can become a cost-effective alternative. To decrease the personal and financial burden of follow-up for a growing number of colorectal cancer survivors, a more acceptable, flexible and dynamic care follow-up mode consisting of enhanced communication and role definitions among clinicians is warranted.


Assuntos
Assistência ao Convalescente/métodos , Atitude Frente a Saúde , Sobreviventes de Câncer , Neoplasias Colorretais/terapia , Oncologia , Recidiva Local de Neoplasia/diagnóstico , Atenção Primária à Saúde , Telemedicina , Atitude do Pessoal de Saúde , Análise Custo-Benefício , Gastroenterologia , Humanos , Aceitação pelo Paciente de Cuidados de Saúde , Oncologia Cirúrgica
6.
J Phys Condens Matter ; 32(42): 425601, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32585641

RESUMO

There is an ongoing dispute in the community about the absence of a magnetic quantum critical point (QCP) in the noncentrosymmetric heavy fermion compound CeRhSi3. In order to explore this question we prepared single crystals of CeRh(Si1-x Ge x )3 with x = 0.05 and 0.15 and determined the temperature-pressure (T-p) phase diagram by means of measurements of the electrical resistivity. The substitution of isoelectronic but large Ge enforces a lattice volume increase resulting in a weakening of the Kondo interaction. As a result, the x = 0.05 and x = 0.15 compound exhibit a transition into the antiferromagnetic (AFM) at higher temperatures being T N = 4.7 K and T N1 = 19.7 K, respectively. Application of pressure suppresses T N (T N1) monotonically and pressure induced superconductivity is observed in both Ge-substituted compounds above p ⩾ 2.16 GPa (x = 0.05) and p ⩾ 2.93 GPa (x = 0.15). Extrapolation of T N(p) → 0 of CeRh(Si0.95Ge0.05)3 yields a critical pressure of p c ≈ 3.4 GPa (in CeRh(Si0.85Ge0.15)3 p c ≈ 3.5 GPa) pointing to the presence of an AFM QCP located deep inside the superconducting state.

7.
BMC Med Educ ; 19(1): 118, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035995

RESUMO

BACKGROUND: Since patient-centered communication is directly connected to clinical performance, it should be integrated with medical knowledge and clinical skills. Therefore, clinical communication skills should be trained and assessed as an integral part of the student's clinical performance. We were unable to identify a tool, which helps when assessing patient-centered communication skills as an integrated component of medical history taking ('the integrated medical interview'). Therefore, we decided to design a new tailor-made assessment tool, the BOCC (BeOordeling Communicatie en Consultvoering (Dutch), Assessment of Communication and Consultation (English) to help raters assess students' integrated clinical communication skills with the emphasis on patient-centred communication combined with the correct medical content. This is a first initiative to develop such a tool, and this paper describes the first steps in this process. METHODS: We investigated the tool in a group of third-year medical students (n = 672) interviewing simulated patients. Internal structure and internal consistency were assessed. Regression analysis was conducted to investigate the relationship between scores on the instrument and general grading. Applicability to another context was tested in a group of fourth-year medical students (n = 374). RESULTS: PCA showed five components (Communication skills, Problem clarification, Specific History, Problem influence and Integration Skills) with various Cronbach's alpha scores. The component Problem Clarification made the strongest unique contribution to the grade prediction. Applicability was good when investigated in another context. CONCLUSIONS: The BOCC is designed to help raters assess students' integrated communication skills. It was assessed on internal structure and internal consistency. This tool is the first step in the assessment of the integrated medical interview and a basis for further investigation to reform it into a true measurement instrument on clinical communication skills.


Assuntos
Competência Clínica/normas , Educação de Graduação em Medicina/normas , Avaliação Educacional/métodos , Encaminhamento e Consulta/normas , Estudantes de Medicina , Currículo , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Anamnese , Modelos Educacionais , Relações Médico-Paciente , Garantia da Qualidade dos Cuidados de Saúde
8.
Neuromuscul Disord ; 29(1): 30-38, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30578099

RESUMO

Mutations in RYR1 are a common genetic cause of non-dystrophic neuromuscular disorders. To obtain baseline data concerning the prevalence of fatigue, the psychological disease burden and quality of life associated with these common conditions, we performed a questionnaire study. Seventy-two patients were included in this study, 33 with a congenital myopathy and 39 with malignant hyperthermia or exertional rhabdomyolysis. Our results showed that patients with RYR1-related myopathies have more functional impairments and significant chronic fatigue compared to healthy controls, with almost half of patients being severely fatigued. Whilst fatigue, pain and associated physical and social difficulties were more pronounced in those with permanent phenotypes, individuals with intermittent phenotypes also scored higher in all relevant categories compared to healthy controls. These findings indicate that RYR1-related myopathies, despite being often considered relatively mild conditions, are nevertheless associated with severe fatigue and functional limitations, resulting in substantial loss of quality of life. Moreover, milder but in essence similar findings in patients with RYR1-related malignant hyperthermia and rhabdomyolysis suggest that those phenotypes are not truly episodic but in fact associated with a substantial permanent disease burden. These preliminary data should help to design more comprehensive quality of life studies to inform standards of care.


Assuntos
Fadiga/fisiopatologia , Doenças Musculares/genética , Doenças Musculares/fisiopatologia , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Estudos de Coortes , Estudos Transversais , Avaliação da Deficiência , Fadiga/genética , Feminino , Humanos , Masculino , Hipertermia Maligna/fisiopatologia , Hipertermia Maligna/psicologia , Pessoa de Meia-Idade , Doenças Musculares/psicologia , Fenótipo , Dados Preliminares , Qualidade de Vida , Inquéritos e Questionários
9.
Sci Rep ; 5: 15904, 2015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26514364

RESUMO

Many current research efforts in strongly correlated systems focus on the interplay between magnetism and superconductivity. Here we report on coexistence of both cooperative ordered states in recently discovered stoichiometric and fully inversion symmetric heavy fermion compound Ce3PdIn11 at ambient pressure. Thermodynamic and transport measurements reveal two successive magnetic transitions at T1 = 1.67 K and TN = 1.53 K into antiferromagnetic type of ordered states. Below Tc = 0.42 K the compound enters a superconducting state. The large initial slope of dBc2/dT ≈ - 8.6 T/K indicates that heavy quasiparticles form the Cooper pairs. The origin of the two magnetic transitions and the coexistence of magnetism and superconductivity is briefly discussed in the context of the coexistence of the two inequivalent Ce-sublattices in the unit cell of Ce3PdIn11 with different Kondo couplings to the conduction electrons.

10.
Ann Behav Med ; 49(1): 66-73, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24838871

RESUMO

BACKGROUND: Anxious people show an attentional bias towards threatening information. PURPOSE: It was investigated whether an attentional bias exists for cancer-related stimuli in breast cancer survivors and if different levels of fear of cancer recurrence would lead to different patterns of selective attention. METHODS: Breast cancer survivors with high (n = 35) and low (n = 32) fear of cancer recurrence were compared to 40 healthy female hospital employees. Specificity of attentional biases was investigated using a modified Emotional Stroop Task. Self-report measures were used to assess depression and anxiety, feelings of fatigue, and experienced traumas. RESULTS: Compared to control participants, breast cancer survivors with both high and low levels of fear of cancer recurrence showed increased interference for cancer-related words, but not for other word types. CONCLUSIONS: The findings suggest a specific attentional bias for cancer-related words in breast cancer survivors that is independent of level of fear of cancer recurrence.


Assuntos
Atenção , Neoplasias da Mama/psicologia , Medo/psicologia , Recidiva Local de Neoplasia/psicologia , Sobreviventes/psicologia , Adulto , Idoso , Ansiedade/psicologia , Emoções , Feminino , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Autorrelato , Saúde da Mulher
11.
Gene Ther ; 20(12): 1158-64, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24005577

RESUMO

Ex vivo gene therapy during coronary artery bypass grafting (CABG) holds great potential to prevent excessive smooth muscle cell (SMC) proliferation, neointima formation and graft failure. The most successful preclinical strategies to date have utilised vectors based on the species C adenovirus, Ad5, which engages the Coxsackie and Adenovirus receptor (CAR) as its primary attachment receptor. Profiling receptors on human SMCs demonstrated the absence of CAR but substantial expression of the species B receptor CD46. We performed transduction experiments using Ad5 and the CD46-utilising adenovirus Ad35, and found Ad35 significantly more efficient at transducing SMCs. To evaluate whether transduction could be further augmented, we evaluated chimeric CD46-utilising Ad5/Ad35 vectors comprising the Ad5 capsid pseudotyped with the Ad35 fibre alone (Ad5/F35) or in combination with the Ad35 penton (Ad5/F35/P35). In human smooth muscle cells (hSMCs), Ad5/F35/P35 mediated significantly higher levels of transduction than either parental vector or Ad5/F35. Ex vivo transduction experiments using mouse aortas from CD46 transgenics demonstrated that Ad5/F35/P35 was significantly more efficient at transducing SMCs than the other vectors tested. Finally, ex vivo transduction and immunofluorescent colocalisation experiments using human tissue from CABG procedures confirmed the preclinical potential of Ad5/F35/P35 as an efficient vector for vascular transduction during CABG.


Assuntos
Adenovírus Humanos/genética , Proteínas do Capsídeo/metabolismo , Capsídeo/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Transdução Genética , Adenovírus Humanos/classificação , Animais , Aorta , Células Cultivadas , Ponte de Artéria Coronária , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/cirurgia , Doença da Artéria Coronariana/terapia , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus/metabolismo , Terapia Genética , Vetores Genéticos , Humanos , Proteína Cofatora de Membrana/genética , Proteína Cofatora de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Músculo Liso Vascular/virologia , Neointima/patologia , Neointima/terapia
12.
J Phys Condens Matter ; 25(41): 416006, 2013 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-24055927

RESUMO

We report on detailed low-temperature measurements of the magnetization, the specific heat and the electrical resistivity on high-quality CeRuSn single crystals. The compound orders antiferromagnetically at T(N) = 2.8 K with the Ce(3+) ions locked within the a-c plane of the monoclinic structure. Magnetization shows that below T(N) CeRuSn undergoes a metamagnetic transition when applying a magnetic field of 1.5 and 0.8 T along the a- and c-axis, respectively. This transition manifests in a tremendous negative jump of ~25% in the magnetoresistance. The value of the saturated magnetization along the easy magnetization direction (c-axis) and the magnetic entropy above T(N) derived from specific heat data correspond to the scenario of only one third of the Ce ions in the compound being trivalent and carrying a stable Ce(3+) magnetic moment, whereas the other two thirds of the Ce ions are in a nonmagnetic tetravalent and/or mixed valence state. This is consistent with the low-temperature CeRuSn crystal structure i.e., a superstructure consisting of three unit cells of the CeCoAl type piled up along the c-axis, and in which the Ce(3+) ions are characterized by large distances from the Ru ligands while the Ce-Ru distances of the other Ce ions are much shorter causing a strong 4f-ligand hybridization and hence leading to tetravalent and/or mixed valence Ce ions.


Assuntos
Ligas/química , Cristalização , Campos Magnéticos , Metais/química , Modelos Químicos , Modelos Moleculares , Simulação por Computador , Teste de Materiais , Condutividade Térmica
13.
Nat Mater ; 11(3): 189-94, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22231597

RESUMO

How ground states of quantum matter transform between one another reveals deep insights into the mechanisms stabilizing them. Correspondingly, quantum phase transitions are explored in numerous materials classes, with heavy-fermion compounds being among the most prominent ones. Recent studies in an anisotropic heavy-fermion compound have shown that different types of transitions are induced by variations of chemical or external pressure, raising the question of the extent to which heavy-fermion quantum criticality is universal. To make progress, it is essential to broaden both the materials basis and the microscopic parameter variety. Here, we identify a cubic heavy-fermion material as exhibiting a field-induced quantum phase transition, and show how the material can be used to explore one extreme of the dimensionality axis. The transition between two different ordered phases is accompanied by an abrupt change of Fermi surface, reminiscent of what happens across the field-induced antiferromagnetic to paramagnetic transition in the anisotropic YbRh2Si2. This finding leads to a materials-based global phase diagram--a precondition for a unified theoretical description.


Assuntos
Cério/química , Paládio/química , Anisotropia , Metais/química , Transição de Fase , Dióxido de Silício/química , Itérbio/química
14.
J Phys Condens Matter ; 23(9): 094208, 2011 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-21339561

RESUMO

The heavy fermion compound Ce3Pd20Si6 is one of the rare examples of a cubic system with a readily accessible quantum critical point. Ce atoms at the two different sites 4a and 8c of the crystal structure have recently been shown to have different crystal field ground states (Γ7 and Γ8, respectively) and are assumed to be responsible for the two different low-temperature phase transitions at T(L) and T(U), which have been tentatively attributed to antiferromagnetic and antiferroquadrupolar order, respectively. Here we present electrical resistivity measurements in a wide temperature range (50 mK-300 K) on two new representatives of the La substitution series Ce(3 - x)La(x)Pd20Si6, x=1/3 and 2/3. Put in the context of previously published data our results indicate that La preferentially occupies the 4a site and that Ce ions at the 8c site have a sizably larger Kondo temperature. Low-temperature resistivity measurements in applied magnetic fields suggest that (disorder smeared) quantum critical points exist in the x=1/3 and 2/3 samples at fields below 1 T.

15.
Phys Rev Lett ; 104(18): 186402, 2010 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-20482193

RESUMO

The canonical view of heavy fermion quantum criticality assumes a single quantum critical point separating the paramagnet from the antiferromagnet. However, recent experiments on Yb-based heavy fermion compounds suggest the presence of non-Fermi liquid behavior over a finite zero-temperature region. Using detailed susceptibility and transport measurements we show that the classic quantum critical system, Ge-substituted YbRh(2)Si(2), also displays such behavior. We advance arguments that this is not due to a disorder-smeared quantum critical point, but represents a new class of metallic phase.

16.
Dalton Trans ; 39(4): 1071-7, 2010 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-20066193

RESUMO

Single crystals of the type-I clathrate Ba(8)Ni(3.5)Ge(42.1)square(0.4) (space group Pm3n, no. 223, a = 10.798(2) A, l = 30 mm, slashed circle = 8 mm) were grown from the melt using the Bridgman technique. Their composition, determined by microprobe analysis, reveals a distinctly lower Ni content than previously reported for the lower limit (x = 5.4) of the homogeneity range of the clathrate-I phase Ba(8)Ni(x)Ge(46-x). From single crystal X-ray diffraction data we introduce a crystal structure model that takes point defects (vacancies) square in the Ge network into account. It reveals that both Ni and square accumulate at a single site (6c) and that, as a consequence, the Ge network distorts considerably. Ba(8)Ni(3.5)Ge(42.1)square(0.4) shows metal-like behaviour (drho/dT > 0) albeit with high resistivity at room temperature (rho(300 K) approximately 1 mOmega cm). Together with the low charge carrier concentration of 2.3 e(-)/unit cell at 300 K this is typical of a degenerate semiconductor. The lattice thermal conductivity is distinctly smaller than that of Ba(8)Ge(43)square(3), where the vacancies partially order, and smaller than those of Ba-Ni-Ge type-I clathrates without vacancies, suggesting that disordered vacancies efficiently scatter heat-transporting phonons. We provide evidence that the maximum value of the thermoelectric figure of merit reached in Ba(8)Ni(3.5)Ge(42.1)square(0.4), ZT(680 K) congruent with 0.21, can be further improved by adjusting the charge carrier concentration.

17.
Vaccine ; 27(19): 2588-93, 2009 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-19428865

RESUMO

Reverse genetics, the generation of influenza viruses from cDNA, presents a rapid method for creating vaccine strains. The technique necessitates the use of cultured cells. Due to technical and regulatory requirements, the choice of cell lines for production of human influenza vaccines is limited. PER.C6 cells, among the most extensively characterized and documented cells, support growth of all influenza viruses tested to date, and can be grown to high densities in large bioreactors in the absence of serum or micro carriers. Here, the suitability of these cells for the generation of influenza viruses by reverse genetics was investigated. A range of viruses reflective of vaccine strains was rescued exclusively using PER.C6 cells by various transfection methods, including an animal component-free procedure. Furthermore, a whole inactivated vaccine carrying the HA and NA segments of A/HK/156/97 (H5N1) that was both rescued from and propagated on PER.C6 cells, conferred protection in a mouse model. Thus PER.C6 cells provide an attractive platform for generation of influenza vaccine strains via reverse genetics.


Assuntos
Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H3N2/crescimento & desenvolvimento , Virus da Influenza A Subtipo H5N1/crescimento & desenvolvimento , Vacinas contra Influenza/genética , Vírus Reordenados/crescimento & desenvolvimento , Animais , Anticorpos Antivirais/sangue , Técnicas de Cultura de Células , Linhagem Celular , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Vírus Reordenados/genética , Vírus Reordenados/imunologia , Índice de Gravidade de Doença , Análise de Sobrevida , Transfecção/métodos , Ensaio de Placa Viral
18.
Vaccine ; 25(12): 2228-37, 2007 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-17250936

RESUMO

The presence of replication-competent adenovirus (RCA) is a safety concern for biologics based on recombinant adenoviruses and RCA testing is therefore mandatory for release of clinical material. RCA, which arises from homologous recombination between Ad5 vectors and HEK-293 cells, can be eliminated by the use of PER.C6 cells in combination with a matched vector. However, little is known on RCA formation with vectors based on adenovirus serotypes other than Ad5 and reliable RCA assays to test them are generally lacking. Here we report on the development and qualification of a sensitive RCA assay for Ad35, a promising alternative to Ad5 vectors. The assay is able to detect 1 RCA in 3x10(10) vector particles with 95% confidence, thus meeting current FDA requirements, and can discriminate between RCA and other rare CPE-causing entities, including helper dependent E1 positive particles (HDEP). Using this assay, the first batches of Ad35 vectors produced in PER.C6 cells were analysed and found to be free of RCA and HDEP. Based on the statistical model used, we anticipate that our approach to RCA assay development can be broadly applicable to other adenoviral vectors.


Assuntos
Adenoviridae/genética , Proteínas E1 de Adenovirus/genética , Bioensaio/métodos , Deleção de Genes , Replicação Viral , Adenoviridae/crescimento & desenvolvimento , Linhagem Celular , Linhagem Celular Tumoral , Vetores Genéticos/genética , Humanos , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
19.
Langmuir ; 22(26): 10932-41, 2006 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-17154568

RESUMO

We perform differential potentiometric titration measurements for the binding of Ca2+ ions to micelles composed of the carboxylic acid end-standing Pluronic P85 block copolymer (i.e., CAE-85 (COOH-(EO)26-(PO)39-(EO)26-COOH)). Two different ion-selective electrodes (ISEs) are used to detect the free calcium concentration; the first ISE is an indicator electrode, and the second is a reference electrode. The titration is done by adding the block copolymers to a known solution of Ca2+ at neutral pH and high enough temperature (above the critical micellization temperature CMT) and various amount of added monovalent salt. By measuring the difference in the electromotive force between the two ISEs, the amount of Ca2+ that is bound by the micelles is calculated. This is then used to determine the binding constant of Ca2+ with the micelles, which is a missing parameter needed to perform molecular realistic self-consistent-field (SCF) calculations. It turns out that the micelles from block copolymer CAE-85 bind Ca2+ ions both electrostatically and specifically. The specific binding between Ca2+ and carboxylic groups in the corona of the micelles is modeled through the reaction equilibrium -COOCa+ <==> -COO- + Ca2+ with pKCa = 1.7 +/- 0.06.

20.
Phys Rev Lett ; 96(25): 256403, 2006 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-16907329

RESUMO

We report a comprehensive study of CeIn3-xSnx (0.55

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