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1.
Nanoscale Adv ; 5(17): 4402-4414, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37638158

RESUMO

Nanodiamonds (NDs) are versatile, broadly available nanomaterials with a set of features highly attractive for applications from biology over energy harvesting to quantum technologies. Via synthesis and surface chemistry, NDs can be tuned from the sub-micron to the single-digit size, from conductive to insulating, from hydrophobic to hydrophilic, and from positively to negatively charged surface by simple annealing processes. Such ND diversity makes it difficult to understand and take advantage of their electronic properties. Here we present a systematic correlated study of structural and electronic properties of NDs with different origins and surface terminations. The absolute energy level diagrams are obtained by the combination of optical (UV-vis) and photoelectron (UPS) spectroscopies, Kelvin probe measurements, and energy-resolved electrochemical impedance spectroscopy (ER-EIS). The energy levels and density of states in the bandgap of NDs are correlated with the surface chemistry and structure characterized by FTIR and Raman spectroscopy. We show profound differences in energy band shifts (by up to 3 eV), Fermi level position (from p-type to n-type), electron affinity (from +0.5 eV to -2.2 eV), optical band gap (5.2 eV to 5.5 eV), band gap states (tail or mid-gap), and electrical conductivity depending on the high-pressure, high-temperature and detonation origin of NDs as well as on the effects of NDs' oxidation, hydrogenation, sp2/sp3 carbon phases and surface adsorbates. These data are fundamental for understanding and designing NDs' optoelectrochemical functional mechanisms in diverse application areas.

4.
Molecules ; 28(13)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37446891

RESUMO

In this study, three types of sulfonic acid group functionalized ionic liquids (SAILs) with a different number of catalytic groups and lipophilicity were synthesized and characterized by FT-IR, NMR, and MS analyses. Their catalytic activities were studied in a model esterification of oleic acid with ethanol; heating in a microwave reactor was also used. The experimental results indicated that SAIL, with the lipophilic alkyl chain, performed the best due to its increased solubility in the reaction mixture. Microwave heating was found to be more effective than conventional heating. Recycling experiments show that these novel SAILs can be reused without significant loss of the catalytic activity.


Assuntos
Ácidos Graxos , Líquidos Iônicos , Esterificação , Ácidos Graxos/química , Líquidos Iônicos/química , Ácidos Sulfônicos , Espectroscopia de Infravermelho com Transformada de Fourier , Catálise
5.
Front Psychiatry ; 14: 1127511, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37032913

RESUMO

This 8-week study was designed to explore any correlation between a passive data collection approach using a wearable device (i.e., digital phenotyping), active data collection (patient's questionnaires), and a traditional clinical evaluation [Montgomery-Åsberg Depression Rating Scale (MADRS)] in patients with major depressive disorder (MDD) treated with trazodone once a day (OAD). Overall, 11 out of 30 planned patients were enrolled. Passive parameters measured by the wearable device included number of steps, distance walked, calories burned, and sleep quality. A relationship between the sleep score (derived from passively measured data) and MADRS score was observed, as was a relationship between data collected actively (assessing depression, sleep, anxiety, and warning signs) and MADRS score. Despite the limited sample size, the efficacy and safety results were consistent with those previously reported for trazodone. The small population in this study limits the conclusions that can be drawn about the correlation between the digital phenotyping approach and traditional clinical evaluation; however, the positive trends observed suggest the need to increase synergies among clinicians, patients, and researchers to overcome the cultural barriers toward implementation of digital tools in the clinical setting. This study is a step toward the use of digital data in monitoring symptoms of depression, and the preliminary data obtained encourage further investigations of a larger population of patients monitored over a longer period of time.

6.
Materials (Basel) ; 16(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37049179

RESUMO

A systematic experimental study was performed to determine laser irradiation conditions for the large-area fabrication of highly regular laser-induced periodic surface structures (HR-LIPSS) on a 220 nm thick Mo film deposited on fused silica. The LIPSS were fabricated by scanning a linearly polarized, spatially Gaussian laser beam at 1030 nm wavelength and 1.4 ps pulse duration over the sample surface at 1 kHz repetition rate. Scanning electron microscope images of the produced structures were analyzed using the criterion of the dispersion of the LIPSS orientation angle (DLOA). Favorable conditions, in terms of laser fluence and beam scanning overlaps, were identified for achieving DLOA values <10∘. To gain insight into the material behavior under these irradiation conditions, a theoretical analysis of the film heating was performed, and surface plasmon polariton excitation is discussed. A possible effect of the film dewetting from the dielectric substrate is deliberated.

7.
Atmos Chem Phys ; 22(1): 641-674, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35136405

RESUMO

Aerosol-cloud interactions (ACIs) are considered to be the most uncertain driver of present-day radiative forcing due to human activities. The nonlinearity of cloud-state changes to aerosol perturbations make it challenging to attribute causality in observed relationships of aerosol radiative forcing. Using correlations to infer causality can be challenging when meteorological variability also drives both aerosol and cloud changes independently. Natural and anthropogenic aerosol perturbations from well-defined sources provide "opportunistic experiments" (also known as natural experiments) to investigate ACI in cases where causality may be more confidently inferred. These perturbations cover a wide range of locations and spatiotemporal scales, including point sources such as volcanic eruptions or industrial sources, plumes from biomass burning or forest fires, and tracks from individual ships or shipping corridors. We review the different experimental conditions and conduct a synthesis of the available satellite datasets and field campaigns to place these opportunistic experiments on a common footing, facilitating new insights and a clearer understanding of key uncertainties in aerosol radiative forcing. Cloud albedo perturbations are strongly sensitive to background meteorological conditions. Strong liquid water path increases due to aerosol perturbations are largely ruled out by averaging across experiments. Opportunistic experiments have significantly improved process-level understanding of ACI, but it remains unclear how reliably the relationships found can be scaled to the global level, thus demonstrating a need for deeper investigation in order to improve assessments of aerosol radiative forcing and climate change.

8.
Colloids Surf B Biointerfaces ; 204: 111689, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33932892

RESUMO

Due to high biocompatibility, miniaturization, optical transparency and low production cost together with high radiation hardness the diamond-based sensors are considered promising for radiation medicine and biomedicine in general. Here we present detection of fibroblast cell culture properties by nanocrystalline diamond solution-gated field-effect transistors (SG-FET), including effects of gamma irradiation. We show that blank nanocrystalline diamond field-effect biosensors are stable at least up to 300 Gy of γ irradiation. On the other hand, gate current of the diamond SG-FET biosensors with fibroblastic cells increases exponentially over an order of magnitude with increasing radiation dose. Extracellular matrix (ECM) formation is also detected and analyzed by correlation of electronic sensor data with optical, atomic force, fluorescence, and scanning electron microscopies.


Assuntos
Técnicas Biossensoriais , Diamante , Matriz Extracelular , Fibroblastos , Microscopia Eletrônica de Varredura
10.
Sci Rep ; 11(1): 590, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33437005

RESUMO

Nanoscale composite of detonation nanodiamond (DND) and polypyrrole (PPy) as a representative of organic light-harvesting polymers is explored for energy generation, using nanodiamond as an inorganic electron acceptor. We present a technology for the composite layer-by-layer synthesis that is suitable for solar cell fabrication. The formation, pronounced material interaction, and photovoltaic properties of DND-PPy composites are characterized down to nanoscale by atomic force microscopy, infrared spectroscopy, Kelvin probe, and electronic transport measurements. The data show that DNDs with different surface terminations (hydrogenated, oxidized, poly-functional) assemble PPy oligomers in different ways. This leads to composites with different optoelectronic properties. Tight material interaction results in significantly enhanced photovoltage and broadband (1-3.5 eV) optical absorption in DND/PPy composites compared to pristine materials. Combination of both oxygen and hydrogen functional groups on the nanodiamond surface appears to be the most favorable for the optoelectronic effects. Theoretical DFT calculations corroborate the experimental data. Test solar cells demonstrate the functionality of the concept.

11.
Nanotoxicology ; 12(8): 797-818, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30182770

RESUMO

Glycodendrimers (Glyco-DDMs) represent a rapidly growing class of nanoparticles with promising properties for biomedical applications but concerns regarding the impact on human health and environment are still justified. Here we report, for the first time, the comparative study of in vivo developmental toxicity of carbosilane Glyco-DDMs and their cytotoxicity in vitro. Carbosilane Glyco-DDMs (generation 1-3) containing 4, 8, and 16 ß-d-glucopyranosyl units at the periphery (DDM1Glu, DDM2Glu, and DDM3Glu) were synthesized and characterized by 1H, 13C and 29Si NMR, mass spectrometry, dynamic light scattering, atomic force microscopy (AFM), and computer modeling. In vitro cytotoxicity assay (MTT) of DDM1-3Glu was performed on three different rodent cell lines (Cricetulus griseus) - B14 (ATCC, CCL-14.1), BRL 3A (ATCC, CRL-1442), and NRK 52E (ATCC, CRL-1571). Overall, very low cytotoxicity was observed with calculated IC50 in mM range with slight difference between each cell line and DDM generation investigated. Modified fish embryo test (FET) was further used for DDM3Glu developmental toxicity testing on zebrafish (Danio rerio) embryos. While seemingly harmless to intact embryos, adverse effects of DDMs on the embryonic development become evident after chorion removal (LD50=2.78 µM at 96 hpe). We summarized that the modified FET test showed a two to three orders of magnitude difference between the in vitro cytotoxicity and in vivo developmental toxicity of DDM3Glu. While, in general, the Glyco-DDMs show great promises as efficient vectors in targeted drug delivery or as therapeutic molecules itself, we suggest that their developmental toxicity should be thoroughly investigated to exclude safety risks associated with their potential biomedical use.


Assuntos
Dendrímeros/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Silanos/toxicidade , Teratogênicos/toxicidade , Peixe-Zebra , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Dendrímeros/química , Glucose/química , Humanos , Dose Letal Mediana , Modelos Moleculares , Silanos/química , Propriedades de Superfície , Teratogênicos/química , Testes de Toxicidade , Peixe-Zebra/embriologia
12.
J Mass Spectrom ; 53(10): 986-996, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30019544

RESUMO

Macromolecular polyelectrolytes are gaining considerable attention for the application in medicine that implies their detailed characterization. We have successfully applied electrospray ionization mass spectrometry (ESI MS) to the analysis of defects in the structure of three generations of polycationic carbosilane dendrimers bearing series of quarternary phosphonium groups at their periphery. Besides expected defects caused by incomplete conversion of particular reaction steps during the synthesis of dendritic scaffold and subsequent peripheral functionalization, also, several products of side reactions were observed together with defects created in the course of measurement (particularly ion exchange products). Defective molecules can be to some extent separated by means of gel permeation chromatography that proves that they are not products of in source fragmentation processes. Within the reaction sequence used for the synthesis of dendrimers under study, hydrosilylation was the source of most defects; the effectivity of quarternization depends on the type of phosphine. Results confirm high sensitivity of ESI MS towards defects, stability of the carbosilane skeleton towards fragmentation under the conditions of ESI ionization, and capability to detect both lower- and higher-molecular weight impurities arising from the synthetic sequence in the same m/z range as the target dendrimer, thus providing valuable view of the polydispersity.

13.
RSC Adv ; 8(58): 33276-33290, 2018 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-35548149

RESUMO

Improving the performance of p-type photoelectrodes represents a key challenge toward significant advancement in the field of tandem dye-sensitized solar cells. Herein, we demonstrate the application of boron-doped nanocrystalline diamond (B:NCD) thin films, covalently functionalized with a dithienopyrrole-benzothiadiazole push-pull chromophore, as alternative photocathodes. First, a primary functional handle is introduced on H-terminated diamond via electrochemical diazonium grafting. Afterwards, Sonogashira cross-coupling and Cu(i) catalyzed azide-alkyne cycloaddition (CuAAC) reactions are employed to attach the chromophore, enabling the comparison of the degree of surface functionalization and the importance of the employed linker at the diamond-dye interface. X-ray photoelectron spectroscopy shows that surface functionalization via CuAAC results in a slightly higher chromophore coverage compared to the Sonogashira cross-coupling. However, photocurrents and photovoltages, obtained by photoelectrochemical and Kelvin probe measurements, are approximately three times larger on photocathodes functionalized via Sonogashira cross-coupling. Surface functionalization via Sonogashira cross-coupling is thus considered the preferential method for the development of diamond-based hybrid photovoltaics.

14.
Macromol Biosci ; 16(4): 553-66, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26748571

RESUMO

For the design of a biohybrid structure as a ligand-tailored drug delivery system (DDS), it is highly sophisticated to fabricate a DDS based on smoothly controllable conjugation steps. This article reports on the synthesis and the characterization of biohybrid conjugates based on noncovalent conjugation between a multivalent biotinylated and PEGylated poly(amido amine) (PAMAM) dendrimer and a tetrameric streptavidin-small protein binding scaffold. This protein binding scaffold (SA-ABDwt) possesses nM affinity toward human serum albumin (HSA). Thus, well-defined biohybrid structures, finalized by binding of one or two HSA molecules, are available at each conjugation step in a controlled molar ratio. Overall, these biohybrid assemblies can be used for (i) a controlled modification of dendrimers with the HSA molecules to increase their blood-circulation half-life and passive accumulation in tumor; (ii) rendering dendrimers a specific affinity to various ligands based on mutated ABD domain, thus replacing tedious dendrimer-antibody covalent coupling and purification procedures.


Assuntos
Dendrímeros/síntese química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Albumina Sérica/química , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biotina/química , Biotinilação , Linhagem Celular , Dendrímeros/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Ligantes , Modelos Moleculares , Nanopartículas/ultraestrutura , Poliaminas/química , Polietilenoglicóis/química , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Estreptavidina/química , Streptomyces/genética , Streptomyces/metabolismo
16.
Int J Soc Psychiatry ; 60(4): 352-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23775144

RESUMO

BACKGROUND: The chronic course of schizophrenia typically results in severe social, vocational and functional impairment, interferes with patients' autonomy, reduces quality of life and increases disability. AIMS: The aim of our study was: (1) to assess social and functional impairment in schizophrenia outpatients from the Czech Republic and Slovakia; and (2) to examine a relationship between functioning and antipsychotic treatment and demographic variables. METHODS: Schizophrenia outpatients in a stable phase of illness, treated with current antipsychotic medication for a minimum of one month, were enrolled for the study. Demographic and medication data were recorded. The Personal and Social Performance (PSP), Subjective Well-Being under Neuroleptics (SWN) and Clinical Global Impressions (CGI) scales were administered. RESULTS: The total number of study subjects was 926. Most PSP values were within the interval of moderate impairment. Functional performance correlated positively with subjective satisfaction with medication and negatively with symptom severity. Higher education predicted better functioning on PSP. The best performance was associated with a stable relationship and a useful work role. Patients who showed the best level of functioning were more likely to be treated with antipsychotic monotherapy. No difference among drugs in monotherapy was found in subjective satisfaction. CONCLUSIONS: The PSP values of stable schizophrenia outpatients indicated a moderate degree of impairment. Improvement of functional capacity remains one of the unmet needs of schizophrenia patients.


Assuntos
Avaliação da Deficiência , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Adulto , Antipsicóticos/uso terapêutico , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação Pessoal , Esquizofrenia/tratamento farmacológico , Índice de Gravidade de Doença , Eslováquia
17.
Eur Arch Psychiatry Clin Neurosci ; 263(6): 475-84, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22983355

RESUMO

Low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) of the left temporo-parietal cortex (LTPC) has been proposed as a useful therapeutic method for auditory hallucinations (AHs). Stereotactic neuronavigation enables the magnetic coil to be targeted according to the individual parameters obtained from neuroimaging. Individualized rTMS neuronavigated according to 18-fluorodeoxyglucose positron emission tomography ((18)FDG PET) allows us to focus the coil explicitly on a given area with detected maxima of specific abnormalities, thus presuming a higher therapeutic effect of the method. The objective of this study is to test clinical efficacy of neuronavigated LF-rTMS administered according to the local maxima of (18)FDG PET uptake of LTPC and to compare it with treatment effects of standard and sham rTMS. In a double-blind, sham-controlled design, patients with AHs underwent a 10-day series of LF-rTMS using (1) (18)FDG PET-guided "neuronavigation," (2) "standard" anatomically guided positioning, and (3) sham coil. The effect of different rTMS conditions was assessed by the Auditory Hallucinations Rating Scale (AHRS) and the Positive and Negative Syndrome Scale (PANSS). Fifteen patients were randomized to a treatment sequence and ten of them completed all three treatment conditions. The intention-to-treat analysis of AHRS score change revealed superiority of the (18)FDG PET-guided rTMS over both the standard and the sham rTMS. The analyses of the PANSS scores failed to detect significant difference among the treatments. Our data showed acute efficacy of (18)FDG PET-guided rTMS in the treatment of AHs. Neuronavigated rTMS was found to be more effective than standard, anatomically guided rTMS.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Fluordesoxiglucose F18 , Alucinações/patologia , Alucinações/terapia , Estimulação Magnética Transcraniana/métodos , Adulto , Análise de Variância , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Neuronavegação , Tomografia por Emissão de Pósitrons , Escalas de Graduação Psiquiátrica , Psicometria
18.
Int J Psychiatry Clin Pract ; 17(1): 35-43, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22486580

RESUMO

OBJECTIVE: This randomized, 6-week, open-label study compared efficacy of CAD and antidepressant monotherapies (ADM) that had been chosen according to clinical judgment of the attending psychiatrist. METHODS: A total of 60 inpatients (intent-to-treat analysis) with depressive disorder (≥ 1 unsuccessful antidepressant treatment) were randomly assigned to the interventions. The responders who completed the acute phase of study, were evaluated for relapse within 2 months of follow-up treatment. The primary outcome measure was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) and response was defined as a ≥ 50% reduction of MADRS score. RESULTS: Mean changes in total MADRS score from baseline to week 6 for patients in both treatment modalities were not different (ADM = 13.2 ± 8.6 points; CAD = 14.5 ± 9.5 points; P = 0.58). The analysis of covariance performed for significantly higher value of imipramine equivalent dose in CAD group showed only a non-significant between-group difference for total MADRS change (P = 0.17). There were also no differences between groups in response rate (ADM = 48%; CAD = 58%) and number of drop-outs in acute treatment as well as proportion of responders' relapses in the follow-up. CONCLUSION: Both treatment modalities produced clinically relevant reduction of depressive symptomatology in acute treatment of patients with resistant depression and their effect was comparable.


Assuntos
Antidepressivos/administração & dosagem , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
19.
Int J Oncol ; 40(6): 2111-21, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22407486

RESUMO

The Apaf-1 interacting protein (APIP) and the uveal autoantigen with coiled coil domains and ankyrin repeats (UACA) belong to endogenous regulators of the apoptosome apparatus, but their role in tumourigenesis and progression of non-small cell lung carcinoma (NSCLC) is not known. Previous studies demonstrated that APIP inhibits the apoptosome-mediated procaspase-9 activation while UACA induces translocation of Apaf-1 from the cytoplasm into the nucleus. Here, we report for the first time that the expression of APIP and UACA genes is down-regulated on the level of both mRNA and protein in NSCLC cells and tumours. In particular, the expression of APIP protein was strikingly decreased and the expression of UACA mRNA and protein was frequently down-regulated in NSCLC tumours of different histopathological types. Moreover, stage IA NSCLC tumours showed significantly lower expression of UACA mRNA compared to higher stage tumours. The weak increase of both APIP and UACA mRNA levels in the 5-aza-2'-deoxycytidine-treated NSCLC cells indicates that mechanisms other than DNA methylation are involved in the regulation of APIP and UACA gene expression in these cancer cells. Taken together, the down-regulation of APIP and UACA expression suggests that the threshold to activate the apoptosome apparatus may be decreased in NSCLC cells due to the lack of APIP-mediated suppression and UACA-assisted Apaf-1 nuclear entry. Moreover, the loss of UACA-assisted Apaf-1 nuclear translocation may underlie the failure of DNA damage checkpoint activation in NSCLC cells leading to their genomic instability.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Apoptose/genética , Autoantígenos/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Regulação para Baixo , Neoplasias Pulmonares/metabolismo , Adulto , Idoso , Proteínas Reguladoras de Apoptose/metabolismo , Autoantígenos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estatísticas não Paramétricas , Transcrição Gênica
20.
Funct Plant Biol ; 39(2): 103-115, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32480765

RESUMO

The topology of the xylem network is likely to affect the transport of water, propagation of embolism and plant survival and growth. Few studies have been conducted on the hydraulics of the entire water pathway in trees. We evaluated the hydraulic connections from roots to branches in a mature Quercus suber L. tree, through sap flow responses upon branch severing. Sap flow was recorded in branches, stem and roots by the heat field deformation (HFD) method. Results showed that roots, except for the taproot, were hydraulically connected to all branches, but the rest of the tree (stem, branches and taproot) was highly sectored. In the large roots that showed an integrated response to branch severing, the outer xylem was preferentially connected to the same side branch and the inner xylem to the opposite branch. The hydraulic sectoriality in branches, stem and taproot may be regarded as an adaptive trait to water stress. The integrated hydraulic structure of roots is advantageous under patchy soil conditions, but may allow the spread of root diseases. The HFD sap flow method proved extremely useful to calculate xylem flux connectivity between different organs of a large tree, providing a comprehensive picture of its hydraulic architecture.

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