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1.
Phys Rev E ; 99(1-1): 013203, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30780312

RESUMO

The self-diffusion phenomenon in a two-dimensional dusty plasma at extremely strong (effective) magnetic fields is studied experimentally and by means of molecular dynamics simulations. In the experiment the high magnetic field is introduced by rotating the particle cloud and observing the particle trajectories in a corotating frame, which allows reaching effective magnetic fields up to 3000 T. The experimental results confirm the predictions of the simulations: (i) superdiffusive behavior is found at intermediate timescales and (ii) the dependence of the self-diffusion coefficient on the magnetic field is well reproduced.

2.
Neuropathol Appl Neurobiol ; 44(6): 606-627, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29575052

RESUMO

AIMS: Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motoneurons and progressive muscle wasting. Inflammatory processes, mediated by non-neuronal cells, such as glial cells, are known to contribute to disease progression. Inflammasomes consist of pattern recognition receptors (PRRs), apoptosis-associated speck-like protein (ASC) and caspase 1 and are essential for interleukin (IL) processing and a rapid immune response after tissue damage. Recently, we described inflammasome activation in the spinal cord of ALS patients and in SOD1(G93A) ALS mice. Since pathological changes in the skeletal muscle are early events in ALS, we hypothesized that PRRs might be abnormally expressed in muscle fibre degeneration. METHODS: Western blot analysis, real-time PCR and immunohistochemistry were performed with muscle tissue from presymptomatic and early-symptomatic male SOD1(G93A) mice and with muscle biopsies of control and sporadic ALS (sALS) patients. Analysed PRRs include nucleotide-binding oligomerization domain-like (NOD-like) receptor protein 1 (NLRP1), NLR protein 3 (NLRP3), NLR family CARD domain-containing 4 (NLRC4) and absent in melanoma 2. Additionally, expression levels of ASC, caspase 1, interleukin 1 beta (IL1ß) and interleukin 18 (IL18) were evaluated. RESULTS: Expression of PRRs and ASC was detected in murine and human tissue. The PRR NLRC4, caspase 1 and IL1ß were significantly elevated in denervated muscle of SOD1(G93A) mice and sALS patients. Furthermore, levels of caspase 1 and IL1ß were already increased in presymptomatic animals. CONCLUSION: Our findings suggest that increased inflammasome activation may be involved in skeletal muscle pathology in ALS. Furthermore, elevated levels of NLRC4, caspase 1 and IL1ß reflect early changes in the skeletal muscle and may contribute to the denervation process.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Inflamassomos/metabolismo , Músculo Esquelético/metabolismo , Receptores de Reconhecimento de Padrão/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Humanos , Camundongos , Músculo Esquelético/patologia , Superóxido Dismutase-1/metabolismo
3.
Z Rheumatol ; 76(9): 752-760, 2017 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-29071482

RESUMO

Nontuberculous mycobacterial (NTM) are found ubiquitously in the environment and are usually of low pathogenicity. Infection occurs via inhalation of aerosols, and some species may cause severe infections. The incidence of NTM infections is rising worldwide. The risk of developing NTM disease depends on the susceptibility of the host as well as the frequency and duration of exposure. In addition to congenital immune deficiencies and immunosuppressive therapy, structural lung and systemic diseases, including rheumatoid arthritis (RA), are associated with an increased risk for NTM infections. The immune response to NTM is complex and relies on the interplay between professional phagocytes and lymphoid cells. This interplay is concerted by three key cytokines: interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Targeted immunotherapies, e. g., treatment with TNF inhibitors, interfere with these essential pathways and increase the risk of NTM infection significantly. This review focuses on the relationship between the immune response to NTM and intrinsic and iatrogenic dispositions for NTM infection, with an emphasis on RA.


Assuntos
Artrite Reumatoide/complicações , Síndromes de Imunodeficiência/complicações , Imunossupressores/efeitos adversos , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções Oportunistas/diagnóstico , Artrite Reumatoide/imunologia , Artrite Reumatoide/terapia , Humanos , Doença Iatrogênica , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/terapia , Imunoterapia , Interferon gama/sangue , Interleucina-12/sangue , Linfócitos/imunologia , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Infecções por Mycobacterium não Tuberculosas/imunologia , Infecções por Mycobacterium não Tuberculosas/terapia , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/imunologia , Infecções Oportunistas/terapia , Fagócitos/imunologia , Fatores de Risco , Fator de Necrose Tumoral alfa/sangue
4.
Pneumologie ; 71(10): 629-680, 2017 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-29017219

RESUMO

Recently, epidemiological data shows an increase of childhood tuberculosis in Germany. In addition to this, drug resistant tuberculosis becomes more frequent. Therefore, diagnosis, prevention and therapy in childhood and adolescence remain a challenge. Adult guidelines do not work for children, as there are age specific differences in manifestation, risk of progression and diagnostic as well as therapeutic pathways.The German Society for Pediatric Infectious Diseases (DGPI) has initiated a consensus-based (S2k) process and completed a paediatric guideline in order to improve and standardize care for children and adolescents with tuberculosis exposure, infection or disease.Updated dosage recommendations take age dependant pharmacokinetics in the treatment of drug sensitive but also drug resistant tuberculosis in account. In addition to this, there is a detailed chapter on perinatal exposure and disease as well as extrapulmonary manifestations.


Assuntos
Antituberculosos/uso terapêutico , Infectologia , Pediatria , Sociedades Médicas , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Áustria , Criança , Pré-Escolar , Estudos Transversais , Feminino , Alemanha , Humanos , Lactente , Recém-Nascido , Masculino , Suíça , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/prevenção & controle , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/prevenção & controle
5.
J Environ Radioact ; 178-179: 203-211, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28892730

RESUMO

Modelling the radionuclide cycle in forests is important in case of contamination due to acute or chronic releases to the atmosphere and from underground waste repositories. This article describes the most important aspects to consider in forest model development. It intends to give an overview of the modelling approaches available and to provide guidance on how to address the quantification of radionuclide transport in forests. Furthermore, the most important gaps in modelling the radionuclide cycle in forests are discussed and suggestions are presented to address the variability of forest sites.


Assuntos
Modelos Químicos , Monitoramento de Radiação/métodos , Poluentes Radioativos/análise , Ecossistema , Florestas , Árvores
6.
Sci Rep ; 7(1): 7329, 2017 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-28779149

RESUMO

Various studies have established the possibility of non-bacterial methane (CH4) generation in oxido-reductive stress conditions in plants and animals. Increased ethanol input is leading to oxido-reductive imbalance in eukaryotes, thus our aim was to provide evidence for the possibility of ethanol-induced methanogenesis in non-CH4 producer humans, and to corroborate the in vivo relevance of this pathway in rodents. Healthy volunteers consumed 1.15 g/kg/day alcohol for 4 days and the amount of exhaled CH4 was recorded by high sensitivity photoacoustic spectroscopy. Additionally, Sprague-Dawley rats were allocated into control, 1.15 g/kg/day and 2.7 g/kg/day ethanol-consuming groups to detect the whole-body CH4 emissions and mitochondrial functions in liver and hippocampus samples with high-resolution respirometry. Mitochondria-targeted L-alpha-glycerylphosphorylcholine (GPC) can increase tolerance to liver injury, thus the effects of GPC supplementations were tested in further ethanol-fed groups. Alcohol consumption was accompanied by significant CH4 emissions in both human and rat series of experiments. 2.7 g/kg/day ethanol feeding reduced the oxidative phosphorylation capacity of rat liver mitochondria, while GPC significantly decreased the alcohol-induced CH4 formation and hepatic mitochondrial dysfunction as well. These data demonstrate a potential for ethanol to influence human methanogenesis, and suggest a biomarker role for exhaled CH4 in association with mitochondrial dysfunction.


Assuntos
Consumo de Bebidas Alcoólicas , Etanol/metabolismo , Metano/biossíntese , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Testes Respiratórios , Hipocampo/metabolismo , Humanos , Fígado/metabolismo , Mitocôndrias/metabolismo , Consumo de Oxigênio , Eliminação Pulmonar , Ratos
7.
Phys Rev E ; 95(1-1): 013209, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28208314

RESUMO

A magnetic field was recently shown to enhance field-parallel heat conduction in a strongly correlated plasma whereas cross-field conduction is reduced. Here we show that in such plasmas, the magnetic field has the additional effect of inhibiting the isotropization process between field-parallel and cross-field temperature components, thus leading to the emergence of strong and long-lived temperature anisotropies when the plasma is locally perturbed. An extended heat equation is shown to describe this process accurately.

8.
Phys Rev Lett ; 119(4): 045001, 2017 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-29341739

RESUMO

Dynamic characteristics of strongly coupled classical one-component Coulomb and Yukawa plasmas are obtained within the nonperturbative model-free moment approach without any data input from simulations so that the dynamic structure factor (DSF) satisfies the first three nonvanishing sum rules automatically. The DSF, dispersion, decay, sound speed, and other characteristics of the collective modes are determined using exclusively the static structure factor calculated from various theoretical approaches including the hypernetted chain approximation. A good quantitative agreement with molecular dynamics simulation data is achieved.

9.
Acta Anaesthesiol Scand ; 61(2): 224-231, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28025820

RESUMO

BACKGROUND: Femoral nerve blocks have been the gold standard approach for post-operative analgesia following total knee arthroplasty; however, the adductor canal block has recently gained popularity due to less block-induced motor weakness. The primary aim of this time-series analysis was to identify whether regional anesthesia practice changes have occurred for total knee arthroplasty. Our secondary aim was to assess for possible associated changes in safety and quality. METHODS: Using a 20-member clinical registry, we examined the practice patterns and safety around the performance of adductor canal blocks for all total knee arthroplasties between 18 July 2011 to 9 October 2015. To obtain more information about changes in quality associated with this practice transition, we analyzed clinical outcomes data surrounding all primary total knee arthroplasties from the largest contributing institution. RESULTS: A total of 6921 blocks were performed for 4822 primary and revision total knee arthroplasties (TKAs). Across the registry, adductor canal block utilization for TKA increased. This was not associated with any increase in immediate or recovery room-related complications. When analyzing unilateral primary TKAs from the largest surgical volume center (n = 766), there were no statistically significant changes in numeric rating scale scores (5.4 to 4.6, P value = 0.004), length of stay (3.0 to 2.8 days, P value = 0.3), or 30-day hospital re-evaluations for pain (2.8-4.9%, P value = 0.1). CONCLUSION: There was a large increase in the utilization of adductor canal blockade for TKAs among participating registry members. This change in practice was not associated with significant changes in safety or quality.


Assuntos
Artroplastia do Joelho , Bloqueio Nervoso/métodos , Dor Pós-Operatória/prevenção & controle , Idoso , Humanos , Tempo de Internação , Pessoa de Meia-Idade , Padrões de Prática Médica
10.
Phys Rev E ; 94(3-1): 033203, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27739697

RESUMO

In a two-dimensional (2D) dusty plasma composed of superparamagnetic, charged dust grains and immersed in an external magnetic field B, the grains interact via both Yukawa and magnetic dipole-dipole potentials. Because the grains' magnetic dipole moments are induced by B, the dipole moments all lie along B. When B is tilted with respect to the normal to the dust layer, the interaction between the grains becomes anisotropic. In our previous paper [Hartmann et al., Phys. Rev. E 89, 043102 (2014)PLEEE81539-375510.1103/PhysRevE.89.043102], we studied the character of waves in such a system, confined strictly to two dimensions, without any spatial extension in the direction perpendicular to the layer. We analyzed how the dispersion of waves depends on the direction of propagation and the relative strengths of the magnetic dipole and Yukawa potentials. In this paper, we consider a more realistic quasi-2D system where the grains are confined by an external potential and can undergo small oscillations perpendicular to the layer. We analyze the effect of the strength of the confining potential on the in-plane correlations and on the wave propagation. In addition to the in-plane compressional and transverse waves, there now appears an out-of-plane transverse wave generated by the oscillation of the grains in the confining potential. The theoretical approach uses the quasi-localized charge approximation paralleled by molecular dynamics simulations.

12.
Phys Rev E ; 93(6): 063209, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27415379

RESUMO

The influence of an external homogeneous magnetic field on the quasilocalization of the particles-characterized quantitatively by cage correlation functions-in strongly coupled three-dimensional Yukawa systems is investigated via molecular dynamics computer simulations over a wide domain of the system parameters (coupling and screening strengths, and magnetic field). The caging time is found to be enhanced by the magnetic field B. The anisotropic migration of the particles in the presence of magnetic field is quantified via computing directional correlation functions, which indicate a more significant increase of localization in the direction perpendicular to B, while a moderate increase is also found along the B field lines. Associating the particles' escapes from the cages with jumps of a characteristic length, a connection is found with the diffusion process: the diffusion coefficients derived from the decay time of the directional correlation functions in both the directions perpendicular to and parallel with B are in very good agreement with respective diffusion coefficients values obtained from their usual computation based on the mean-squared displacement of the particles.

13.
Eur J Clin Nutr ; 70(7): 843-51, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27026428

RESUMO

BACKGROUND/OBJECTIVES: Bioimpedance spectroscopy is an accurate non-invasive method for measuring body composition in adults, but in infants it requires further testing and validation. Of the few studies of bioimpedance conducted in infants, none have comprehensively investigated the effect of milk intake volume. This study assessed the effect of the milk intake, feed duration and the volume of the infant's stomach and bladder on the resistance values pre-/post-feed to establish the feasibility of using these values interchangeably during data collection. SUBJECTS/METHODS: Forty-eight breastfeeding infants were measured at 2, 5, 9 and/or 12 months (n=62 sessions) within 1-2 min before the start and after the end of breastfeed. Median (IQR) time between measurements was 24 (20.0-30.0) min. Resistance measurements at 0 and 50 kHz, and infinite frequency (R0, R50 and Rinf) and resistance of intracellular water (Ricw) were analysed with customised infant settings. Milk intake was measured by test weights. Free-water volumes and free-water change were determined from stomach and bladder volumes calculated from ultrasound images. RESULTS: Small pre-to-post-feed changes (median (IQR): R0 -3.7 (-14.8, 14.3); R50 0.3 (-10.4, 15.0); Rinf 2.8 (-13.3, 35.5); Ricw 20.8 (-98.1, 290.9)) were not significantly different from zero (R0: P=0.92; R50: P=0.48; Rinf: P=0.32; Ricw: P=0.097). No significant effect of milk intake or free-water change was detected. CONCLUSIONS: The lack of consistent change in resistance across a breastfeed provides flexibility in the timing of measurements of infants in the research setting, such that typically pre- and post-feed measures of resistance can be used interchangeably.


Assuntos
Aleitamento Materno , Impedância Elétrica , Líquido Extracelular , Leite Humano , Análise Espectral , Água , Estudos de Viabilidade , Comportamento Alimentar , Feminino , Humanos , Lactente , Masculino , Estômago , Bexiga Urinária
14.
Internist (Berl) ; 57(2): 107-16, 2016 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-26838368

RESUMO

Infections with Mycobacterium tuberculosis (MTB) induce complex immune responses involving an orchestrated interplay of innate and adaptive immune mechanisms. Why the immune system fails to eradicate the pathogen and at best achieves control of infection in the latent stage, still remains an unsolved mystery even more than 100 years after the discovery of MTB by Robert Koch. This article provides an overview of the current state of the art in the constantly evolving field of tuberculosis (TB) immunology. This review focuses on a change of paradigm proposing that in the latent stage MTB is anything but dormant and that latent TB is not merely a state of bacterial stasis but a state of dynamic bacterial and immunological equilibrium. The understanding of these dynamics is crucial for the development of new drugs against MTB as well as vaccines that aim to provide effective protection against the disease.


Assuntos
Imunidade Adaptativa/imunologia , Imunidade Inata/imunologia , Tuberculose Latente/imunologia , Tuberculose Latente/microbiologia , Modelos Imunológicos , Mycobacterium tuberculosis/imunologia , Animais , Humanos
15.
Exp Clin Endocrinol Diabetes ; 124(5): 294-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26824283

RESUMO

OBJECTIVE: Recent guidelines recommend an individualized approach towards patients with diabetes mellitus. Data of a programme dealing with quality of diabetes care, "Diabetes TÜV" of the Deutsche BKK was reappraised in the light of recent evidence applying these recommendations. PATIENTS AND METHODS: Data originates from a population-based study in primary diabetes care in Germany. Patients with diabetes mellitus insured by the Deutsche BKK were invited to participate. From 2000 to 2004 data of 4 784 patients participated. Double or multiple visits were not included. HbA1c was analysed in 0.5% categories and in age groups below and above 70 years. HbA1c was DCCT adjusted. RESULTS: A total of 368 patients with diabetes mellitus type 1 (DM1) (42% women, HbA1c 54 mmol/mol (7.1%), BP 136/79 mmHg) and 4 416 patients with diabetes type 2 (DM2) (44% women, HbA1c 48.6 mmol/mol (6.6%), BP 142/81 mmHg) were included.). An HbA1c of 53 mmol/mol (7%) or less was found in 70%, less than 64 mmol/mol (8%) in 87% of all patients, and higher than 86 mmol/mol (10%) in 2.8%. The detailed analysis shows that an HbA1c of <=47.6 mmol/mol (6.5%) is achieved of 38% of people with DM1 and 56% with DM2, an HbA1c <=66 mmol/mol (8.0%) of 79% and 88%, respectively.The mean systolic blood pressure (BP) was 142 mmHg, the diastolic BP was 81 mmHg. Systolic BP increased with age (systolic BP: < 50 years 131 mmHg; 50-70 years 142 mmHg; > 70 years 144 mmHg/diastolic BP: < 50 years 81 mmHg; 50-70 years 82 mmHg; > 70 years 80 mmHg). Using WHO grading, BP is mainly mildly elevated (grade 1: 41% (n=1942); grade 2, 17% (n=820) grade 3 6% (n=281). In 10 patients (0.2%) HbA1c above 86 mmol/mol (10.0%) coincides with a BP WHO grade 3. CONCLUSIONS: In recent years new evidence is available regarding treatment targets. The reappraisal of a cross sectional study of a quality assurance programme of a German health insurance in a differentiated way demonstrates that more than 2/3 of the people with diabetes mellitus meet their specific goals. Only very few patients are at imminent risk due to bad glycaemic control and high blood pressure. Old patients may be at risk of overtreatment. Strategies aiming at adapting pharmacological interventions in older patients must be conceived.


Assuntos
Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/terapia , Assistência Centrada no Paciente , Qualidade da Assistência à Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade
16.
Nanoscale ; 8(3): 1344-51, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26399166

RESUMO

The effects of constrained sample dimensions on the mechanical behavior of crystalline materials have been extensively investigated. However, there is no clear understanding of these effects in nano-sized amorphous samples. Herein, nanoindentation together with finite element simulations are used to compare the properties of crystalline and glassy CoNi(Re)P electrodeposited nanowires (ϕ ≈ 100 nm) with films (3 µm thick) of analogous composition and structure. The results reveal that amorphous nanowires exhibit a larger hardness, lower Young's modulus and higher plasticity index than glassy films. Conversely, the very large hardness and higher Young's modulus of crystalline nanowires are accompanied by a decrease in plasticity with respect to the homologous crystalline films. Remarkably, proper interpretation of the mechanical properties of the nanowires requires taking the curved geometry of the indented surface and sink-in effects into account. These findings are of high relevance for optimizing the performance of new, mechanically-robust, nanoscale materials for increasingly complex miniaturized devices.

17.
J Eur Acad Dermatol Venereol ; 29(12): 2333-41, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26370610

RESUMO

BACKGROUND: Glycerol is known to possess anti-irritant and hydrating properties and previous studies suggested that xylitol may also have similar effects. OBJECTIVE: Our aim was to study whether different concentrations of these polyols restore skin barrier function and soothe inflammation in sodium lauryl sulphate (SLS)-induced acute irritation. METHODS: The experiments were performed on male SKH-1 hairless mice. The skin of the dorsal region was exposed to SLS (5%) for 3 h alone or together with 5% or 10% of glycerol respectively. Further two groups received xylitol solutions (8.26% and 16.52% respectively) using the same osmolarities, which were equivalent to those of the glycerol treatments. The control group was treated with purified water. Transepidermal water loss (TEWL) and skin hydration were determined. Microcirculatory parameters of inflammation were observed by means of intravital videomicroscopy (IVM). Furthermore, accumulation of neutrophil granulocytes and lymphocytes, the expression of inflammatory cytokines and SLS penetration were assessed, as well. RESULTS: Treatment with the 10% of glycerol and both concentrations of xylitol inhibited the SLS-induced elevation of TEWL and moderated the irritant-induced increase in dermal blood flow and in the number of leucocyte-endothelial interactions. All concentrations of the applied polyols improved hydration and prevented the accumulation of lymphocytes near the treatment site. At the mRNA level, neither glycerol nor xylitol influenced the expression of interleukin-1 alpha. However, expression of interleukin-1 beta was significantly decreased by the 10% glycerol treatment, while expression of tumour necrosis factor-alpha decreased upon the same treatment, as well as in response to xylitol. Higher polyol treatments decreased the SLS penetration to the deeper layers of the stratum corneum. CONCLUSION: Both of the analysed polyols exert considerable anti-irritant and anti-inflammatory properties, but the effective concentration of xylitol is lower than that of glycerol.


Assuntos
Dermatite Irritante/tratamento farmacológico , Emolientes/uso terapêutico , Glicerol/uso terapêutico , Fenômenos Fisiológicos da Pele/efeitos dos fármacos , Pele/metabolismo , Xilitol/uso terapêutico , Animais , Dermatite Irritante/etiologia , Dermatite Irritante/patologia , Emolientes/farmacologia , Expressão Gênica/efeitos dos fármacos , Glicerol/farmacologia , Interleucina-1alfa/genética , Interleucina-1beta/genética , Microscopia Intravital , Masculino , Camundongos , Camundongos Pelados , Permeabilidade/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Pele/irrigação sanguínea , Pele/química , Dodecilsulfato de Sódio/farmacocinética , Fator de Necrose Tumoral alfa/genética , Água/análise , Perda Insensível de Água/efeitos dos fármacos , Xilitol/farmacologia
18.
Nanoscale ; 7(30): 12943-54, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26167654

RESUMO

Dendrimersomes are nanosized vesicles constituted by amphiphilic Janus dendrimers (JDs), which have been recently proposed as innovative nanocarriers for biomedical applications. Recently, we have demonstrated that dendrimersomes self-assembled from (3,5)12G1-PE-BMPA-G2-(OH)8 dendrimers can be successfully loaded with hydrophilic and amphiphilic imaging contrast agents. Here, we present two newly synthesized low generation isomeric JDs: JDG0G1(3,5) and JDG0G1(3,4). Though less branched than the above-cited dendrimers, they retain the ability to form self-assembled, almost monodisperse vesicular nanoparticles. This contribution reports on the characterization of such nanovesicles loaded with the clinically approved MRI probe Gadoteridol and the comparison with the related nanoparticles assembled from more branched dendrimers. Special emphasis was given to the in vitro stability test of the systems in biologically relevant media, complemented by preliminary in vivo data about blood circulation lifetime collected from healthy mice. The results point to very promising safety and stability profiles of the nanovesicles, in particular for those made of JDG0G1(3,5), whose spontaneous self-organization in water gives rise to a homogeneous suspension. Importantly, the blood lifetimes of these systems are comparable to those of standard liposomes. By virtue of the reported results, the herein presented nanovesicles augur well for future use in a variety of biomedical applications.


Assuntos
Dendrímeros/química , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Contraste/química , Meios de Contraste/farmacocinética , Meios de Contraste/toxicidade , Dendrímeros/farmacocinética , Dendrímeros/toxicidade , Gadolínio/química , Meia-Vida , Compostos Heterocíclicos/química , Humanos , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células NIH 3T3 , Compostos Organometálicos/química , Albumina Sérica/química , Albumina Sérica/metabolismo , Temperatura , Água/química
19.
Artigo em Inglês | MEDLINE | ID: mdl-24580342

RESUMO

In a plasma containing charged dust grains, the dust acoustic instability (DAI) can be driven by ions streaming through the dust with speed less than the ion thermal speed. When the dust is strongly coupled in the liquid phase, the dispersion relation of the dust acoustic modes changes in a way that leads to an enhancement of the growth rate of the DAI. In this paper, we show how strong coupling enhances the DAI growth rate and consider application to microgravity experiments where subthermal ion flows are in general possible.

20.
Bioinspir Biomim ; 9(1): 016004, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24343246

RESUMO

The diatoms are ubiquitous, exist in large numbers and show a great diversity of features on their porous silica structures. Therefore, they inspire the fabrication of nanostructured templates for nanoimprint processes (NIL), where large structured areas with nanometer precision are required. In this study, two approaches regarding the respective challenges and potential exploitations are followed and discussed: the first one takes advantage of a template that is directly made of natural occurring diatoms. Here, two replication steps via soft lithography are needed to obtain a template which is subsequently used for NIL. The second approach exploits the technical capabilities of the precise 3D laser lithography (3DLL) based on two-photon polymerization of organic materials. This method enables the fabrication of arbitrary artificial diatom-inspired micro- and nanostructures and the design of an inverse structure. Therefore, only one replication step is needed to obtain a template for NIL. In both approaches, a replication technique for true 3D structures is shown.


Assuntos
Materiais Biomiméticos/síntese química , Diatomáceas/ultraestrutura , Lasers , Impressão Molecular/métodos , Nanopartículas/química , Nanopartículas/ultraestrutura , Dióxido de Silício/química , Teste de Materiais , Dióxido de Silício/efeitos da radiação , Propriedades de Superfície/efeitos da radiação
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