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1.
Chembiochem ; 25(9): e202400011, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38415939

RESUMO

Characterization of the aromatic ammonia-lyase from Loktanella atrilutea (LaAAL) revealed reduced activity towards canonical AAL substrates: l-Phe, l-Tyr, and l-His, contrasted by its pronounced efficiency towards 3,4-dimethoxy-l-phenylalanine. Assessing the optimal conditions, LaAAL exhibited maximal activity at pH 9.5 in the ammonia elimination reaction route, distinct from the typical pH ranges of most PALs and TALs. Within the exploration of the ammonia source for the opposite, synthetically valuable ammonia addition reaction, the stability of LaAAL exhibited a positive correlation with the ammonia concentration, with the highest stability in 4 M ammonium carbamate of unadjusted pH of ~9.5. While the enzyme activity increased with rising temperatures yet, the highest operational stability and highest stationary conversions of LaAAL were observed at 30 °C. The substrate scope analysis highlighted the catalytic adaptability of LaAAL in the hydroamination of diverse cinnamic acids, especially of meta-substituted and di-/multi-substituted analogues, with structural modelling exposing steric clashes between the substrates' ortho-substituents and catalytic site residues. LaAAL showed a predilection for ammonia elimination, while classifying as a tyrosine ammonia-lyase (TAL) among the natural AAL classes. However, its distinctive attributes, such as genomic context, unique substrate specificity and catalytic fingerprint, suggest a potential natural role beyond those of known AAL classes.


Assuntos
Amônia-Liases , Biocatálise , Amônia-Liases/metabolismo , Amônia-Liases/química , Especificidade por Substrato , Amônia/metabolismo , Amônia/química , Concentração de Íons de Hidrogênio , Domínio Catalítico , Modelos Moleculares
2.
Public Health ; 229: 13-23, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382177

RESUMO

OBJECTIVES: This study aimed to examine the psychometric properties of the P4 suicide screener in a multinational sample. The primary goal was to evaluate the reliability and validity of the scale and investigate its convergent validity by analyzing its correlation with depression, anxiety, and substance use. STUDY DESIGN: The study design is a cross-sectional self-report study conducted across 42 countries. METHODS: A cross-sectional, self-report study was conducted in 42 countries, with a total of 82,243 participants included in the final data set. RESULTS: The study provides an overview of suicide ideation rates across 42 countries and confirms the structural validity of the P4 screener. The findings indicated that sexual and gender minority individuals exhibited higher rates of suicidal ideation. The P4 screener showed adequate reliability, convergence, and discriminant validity, and a cutoff score of 1 is recommended to identify individuals at risk of suicidal behavior. CONCLUSIONS: The study supports the reliability and validity of the P4 suicide screener across 42 diverse countries, highlighting the importance of using a cross-cultural suicide risk assessment to standardize the identification of high-risk individuals and tailoring culturally sensitive suicide prevention strategies.


Assuntos
Comparação Transcultural , Ideação Suicida , Humanos , Estudos Transversais , Psicometria , Reprodutibilidade dos Testes , Prevenção do Suicídio
3.
Sci Technol Adv Mater ; 25(1): 2292485, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38259326

RESUMO

Among various metal-organic frameworks (MOFs), the zeolitic imidazole framework (ZIF), constructed by the regular arrangement of 2-methylimidazole and metal ions, has garnered significant attention due to its distinctive crystals and pore structures. Variations in the sizes and shapes of ZIF crystals have been reported by changing the synthesis parameters, such as the molar ratios of organic ligands to metal ions, choice of solvents, and temperatures. Nonetheless, the giant ZIF-8 single crystals beyond the typical range have rarely been reported. Herein, we present the synthesis of millimeter-scale single crystal ZIF-8 using the solvothermal method in N,N-diethylformamide. The resulting 1-mm single crystal is carefully characterized through N2 adsorption-desorption isotherms, scanning electron microscopy, and other analytical techniques. Additionally, single-crystal X-ray diffraction is employed to comprehensively investigate the framework's mobility at various temperatures.


Millimeter-sized ZIF-8 single crystals were synthesized using the solvothermal method. These crystals exhibit a notable BET surface area of 1681 m2∙g−1 and demonstrate a reversible change in their crystal structure.

4.
Stud Mycol ; 104: 1-85, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37351542

RESUMO

Fruiting bodies (sporocarps, sporophores or basidiomata) of mushroom-forming fungi (Agaricomycetes) are among the most complex structures produced by fungi. Unlike vegetative hyphae, fruiting bodies grow determinately and follow a genetically encoded developmental program that orchestrates their growth, tissue differentiation and sexual sporulation. In spite of more than a century of research, our understanding of the molecular details of fruiting body morphogenesis is still limited and a general synthesis on the genetics of this complex process is lacking. In this paper, we aim at a comprehensive identification of conserved genes related to fruiting body morphogenesis and distil novel functional hypotheses for functionally poorly characterised ones. As a result of this analysis, we report 921 conserved developmentally expressed gene families, only a few dozens of which have previously been reported to be involved in fruiting body development. Based on literature data, conserved expression patterns and functional annotations, we provide hypotheses on the potential role of these gene families in fruiting body development, yielding the most complete description of molecular processes in fruiting body morphogenesis to date. We discuss genes related to the initiation of fruiting, differentiation, growth, cell surface and cell wall, defence, transcriptional regulation as well as signal transduction. Based on these data we derive a general model of fruiting body development, which includes an early, proliferative phase that is mostly concerned with laying out the mushroom body plan (via cell division and differentiation), and a second phase of growth via cell expansion as well as meiotic events and sporulation. Altogether, our discussions cover 1 480 genes of Coprinopsis cinerea, and their orthologs in Agaricus bisporus, Cyclocybe aegerita, Armillaria ostoyae, Auriculariopsis ampla, Laccaria bicolor, Lentinula edodes, Lentinus tigrinus, Mycena kentingensis, Phanerochaete chrysosporium, Pleurotus ostreatus, and Schizophyllum commune, providing functional hypotheses for ~10 % of genes in the genomes of these species. Although experimental evidence for the role of these genes will need to be established in the future, our data provide a roadmap for guiding functional analyses of fruiting related genes in the Agaricomycetes. We anticipate that the gene compendium presented here, combined with developments in functional genomics approaches will contribute to uncovering the genetic bases of one of the most spectacular multicellular developmental processes in fungi. Citation: Nagy LG, Vonk PJ, Künzler M, Földi C, Virágh M, Ohm RA, Hennicke F, Bálint B, Csernetics Á, Hegedüs B, Hou Z, Liu XB, Nan S, M. Pareek M, Sahu N, Szathmári B, Varga T, Wu W, Yang X, Merényi Z (2023). Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes. Studies in Mycology 104: 1-85. doi: 10.3114/sim.2022.104.01.

5.
Arch Orthop Trauma Surg ; 141(8): 1425-1432, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33715063

RESUMO

BACKGROUND: Intra-articular fractures are associated with posttraumatic arthritis if inappropriately treated. Exact reduction of the joint congruency is the main factor to avoid the development of arthrosis. Aim of this study was to evaluate feasibility of computer-assisted surgical planning and 3D-printed patient-specific instrumentation (PSI) for treatment of distal intraarticular radius fractures. METHOD: 7 Patients who suffered a distal intraarticular radius fracture were enrolled in this prospective case series. Preoperative CT-scan was recorded, whereupon a 3D model was computed for surgical planning and design of PSI for surgical navigation. Postoperative accuracy and joint congruency were assessed. Patients were followed-up 3, 6 and 12 months postoperatively. RESULTS: Mean follow-up was 16 months. Over all range of motion was restored and flexion, extension and pronation showed significant recovery, p < 0.05. Biggest intraarticular joint step-off and gap reduced from average 2.49 (± 1.04) to 0.8 mm (± 0.44), p < 0.05 and 6.12 mm (± 1.04) to 2.21 mm (± 1.16), p < 0.05. Average grip strength restored (3-16 months) from 20.33 kg (± 7.12) to 39.3 kg (± 19.55) p < 0.05, 100% of the healthy contralateral side. 3D-accuracy for guided fragments was 2.07 mm (± 0.64) and 8.59° (± 2.9) and 2.33 mm (± 0.69) and 12.86° (± 7.13), p > 0.05 for fragments reduced with ligamentotaxis. CONCLUSION: Computer-assisted and PSI navigated intraarticular radius fracture treatment is feasible, safe and accurate. The benefits of this method, however, do not outstand the additional effort. LEVEL OF EVIDENCE: IV.


Assuntos
Fraturas Intra-Articulares , Fraturas do Rádio , Adolescente , Adulto , Idoso , Placas Ósseas , Computadores , Feminino , Fixação Interna de Fraturas , Humanos , Fraturas Intra-Articulares/diagnóstico por imagem , Fraturas Intra-Articulares/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fraturas do Rádio/diagnóstico por imagem , Fraturas do Rádio/cirurgia , Amplitude de Movimento Articular , Cirurgia Assistida por Computador , Resultado do Tratamento
6.
Small ; 16(12): e1901718, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31515944

RESUMO

2D transition metal dichalcogenides (TMDs) have received widespread interest by virtue of their excellent electrical, optical, and electrochemical characteristics. Recent studies on TMDs have revealed their versatile utilization as electrocatalysts, supercapacitors, battery materials, and sensors, etc. In this study, MoS2 nanosheets are successfully assembled on the porous VS2 (P-VS2 ) scaffold to form a MoS2 /VS2 heterostructure. Their gas-sensing features, such as sensitivity and selectivity, are investigated by using a quartz crystal microbalance (QCM) technique. The QCM results and density functional theory (DFT) calculations reveal the impressive affinity of the MoS2 /VS2 heterostructure sensor toward ammonia with a higher adsorption uptake than the pristine MoS2 or P-VS2 sensor. Furthermore, the adsorption kinetics of the MoS2 /VS2 heterostructure sensor toward ammonia follow the pseudo-first-order kinetics model. The excellent sensing features of the MoS2 /VS2 heterostructure render it attractive for high-performance ammonia sensors in diverse applications.

7.
J Nanosci Nanotechnol ; 19(2): 770-779, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360152

RESUMO

Functionalization of mesoporous silica KIT-6 with ß-cyclodextrin (ß-CD) was successfully realized via post-grafting method as a new adsorbent for environmental remediation of methylene blue (MB) dye from aqueous solutions. The mesostructure properties were characterized by transmission electron microscope (TEM), low-angel X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and N2 sorption isotherm. The remarkable adsorption of MB into ß-CD-KIT-6 adsorbent was studied using UV-visible spectroscopy. The ß-CD-KIT-6 exhibited higher adsorption capacity compared with unmodified-KIT-6. The adsorption behavior of MB into the ß-CD-KIT-6 and unmodified-KIT-6 was carefully investigated using different kinetic and isotherm models. The adsorption process followed a pseudo-second order kinetic model and well-fitted to Langmuir isotherm. The thermodynamic parameters were evaluated and the adsorption of MB was found to be an exothermic and spontaneous process. The adsorption of MB into the ß-CD-KIT-6 was highly dependent on the solution pH.

8.
J Nanosci Nanotechnol ; 19(7): 3673-3685, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30764925

RESUMO

Hard- and soft-templating approaches are one of potential strategies for the fabrication of functional nanoporous carbon materials with desired morphologies and properties. Enormous efforts have been paid for understanding the synthetic mechanisms that strongly influence the materials design and applications. All of these investigations are crucial to encourage the application of hard- and soft-templating approaches for the precise synthesis of nanoporous carbon materials. In this review, we mainly summarize significant works employing different synthetic methods for making carbon materials with various pore sizes and functionalities. The content of the review article contains: (i) Hard-templating synthesis of microporous carbon from zeolites; (ii) Hard-templating synthesis of mesoporous carbon from mesoporous silica; (iii) Hard-templating synthesis of macroporous carbon; and (iv) Soft-templating synthesis of mesoporous carbon. This review aims to provide a detailed glimpse of hard- and soft-templating approaches for future development of functional nanoporous carbon materials.

9.
Eur J Vasc Endovasc Surg ; 52(6): 721-728, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27839876

RESUMO

OBJECTIVE/BACKGROUND: Asymmetric dimethylarginine (ADMA) inhibits nitric oxide (NO) synthesis and is a marker of atherosclerosis. This study examined the correlation between pre-operative l-arginine and ADMA concentration during carotid endarterectomy (CEA), and jugular lactate indicating anaerobic cerebral metabolism, jugular S100B reflecting blood-brain barrier integrity, and with factors of surgical intervention. METHODS: The concentration of l-arginine, ADMA, and symmetric dimethylarginine was measured in blood taken under regional anaesthesia from the radial artery of 55 patients prior to CEA. Blood gas parameters, concentration of lactate, and S100B were also serially measured in blood taken from both the radial artery and the jugular bulb before and after carotid clamping, and after release of the clamp. To estimate anaerobic metabolism, the jugulo-arterial ratio of CO2 gap/oxygen extraction was calculated. RESULTS: Positive correlation was found between pre-operative ADMA levels and the ratio of jugulo-arterial CO2 gap/oxygen extraction during clamp and reperfusion (p = .005 and p = .01, respectively). An inverse correlation was found between the pre-operative l-arginine concentration and jugular lactate at each time point (both p = .002). The critical pre-operative level of l-arginine was determined by receiver operator curve analysis. If l-arginine was below the cutoff value of 35 µmol/L, jugular S100B concentration was higher 24 h post-operatively (p = .03), and jugular lactate levels were increased during reperfusion (p = .02). The median pre-operative concentration of l-arginine was lower in patients requiring an intra-operative shunt than in patients without need of shunt (median: 30.3 µmol/L [interquartile range 24.4-34.4 µmol/L] vs. 57.6 µmol/L [interquartile range 42.3-74.5 µmol/L]; p = .002). CONCLUSION: High pre-operative ADMA concentration predicts poor cerebral perfusion indicated by elevated jugulo-arterial CO2 gap/oxygen extraction. Low pre-operative l-arginine concentration predicts the need for a shunt. The inverse correlation between pre-operative l-arginine concentration and both jugular lactate and S100B during carotid clamping suggests a protective role of the NO donor l-arginine.


Assuntos
Arginina/análogos & derivados , Estenose das Carótidas/cirurgia , Circulação Cerebrovascular , Endarterectomia das Carótidas/efeitos adversos , Idoso , Anaerobiose , Área Sob a Curva , Arginina/sangue , Biomarcadores/sangue , Gasometria , Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar , Estenose das Carótidas/sangue , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/fisiopatologia , Constrição , Feminino , Humanos , Veias Jugulares , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Artéria Radial , Reprodutibilidade dos Testes , Fatores de Risco , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Fatores de Tempo , Resultado do Tratamento
10.
J Nanosci Nanotechnol ; 16(4): 4200-4, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27451787

RESUMO

Recent reports have demonstrated the practical application of Prussian blue (PB) nanoparticles toward environmental clean-up of radionuclide 173Cs. Herein, we prepared a large amount of PB nanoparticles by mixing both iron(III) chloride and sodium ferrocyanide hydrate as starting precursors. The obtained PB nanoparticles show a high surface area (440 m2. g-1) and consequently an excellent uptake ability of Cs ions from aqueous solutions. The uptake ability of Cs ions into poly(N-isopropylacrylamide (PNIPA) hydrogel is drastically increased up to 156.7 m2. g-1 after incorporating our PB nanoparticles, compared to 30.2 m2 . g-1 after using commercially available PB. Thus, our PB-containing PNIPA hydrogel can be considered as an excellent candidate for the removal of Cs ions from aqueous solutions, which will be useful for the remediation of the nuclear waste.


Assuntos
Césio/isolamento & purificação , Ferrocianetos/química , Hidrogéis/química , Nanopartículas/química , Poluentes Radioativos da Água/isolamento & purificação , Purificação da Água/métodos , Césio/química , Íons , Teste de Materiais , Nanopartículas/ultraestrutura , Água/química , Poluentes Radioativos da Água/química
11.
Clin Exp Dermatol ; 41(5): 547-51, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26800853

RESUMO

Little is known about the altered lipid metabolism-related transcriptional events occuring in sebaceous glands of patients with acne vulgaris. Peroxisome proliferator-activated receptor (PPAR)γ, a lipid-activated transcription factor, is implicated in differentiation and lipid metabolism of sebocytes. We have observed that PPARγ and its target genes, ADRP (adipose differentiation related protein) and PGAR (PPARγ angioprotein related protein) are expressed at lower levels in sebocytes from patients with acne than in those from healthy controls (HCs) Furthermore, endogenous PPARγ activator lipids such as arachidonic acid-derived keto-metabolites (e.g. 5KETE, 12KETE) are increased in acne-involved and nonacne-involved skin of patients with acne, compared with skin from healthy individuals. Our findings highlight the possible anti-inflammatory role of endogenous ligand-activated PPARγ signaling in human sebocyte biology, and suggest that modulating PPARγ- expression and thereby signaling might be a promising strategy for the clinical management of acne vulgaris.


Assuntos
Acne Vulgar/metabolismo , PPAR gama/metabolismo , Glândulas Sebáceas/metabolismo , Transdução de Sinais/fisiologia , Adulto , Análise de Variância , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/metabolismo , Estudos de Casos e Controles , Eicosanoides/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Perilipina-2/metabolismo , RNA Mensageiro/metabolismo
12.
J Am Chem Soc ; 137(4): 1572-80, 2015 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-25580699

RESUMO

Core-shell structured ZIF-8@ZIF-67 crystals are well-designed and prepared through a seed-mediated growth method. After thermal treatment of ZIF-8@ZIF-67 crystals, we obtain selectively functionalized nanoporous hybrid carbon materials consisting of nitrogen-doped carbon (NC) as the cores and highly graphitic carbon (GC) as the shells. This is the first example of the integration of NC and GC in one particle at the nanometer level. Electrochemical data strongly demonstrate that this nanoporous hybrid carbon material integrates the advantageous properties of the individual NC and GC, exhibiting a distinguished specific capacitance (270 F·g(-1)) calculated from the galvanostatic charge-discharge curves at a current density of 2 A·g(-1). Our study not only bridges diverse carbon-based materials with infinite metal-organic frameworks but also opens a new avenue for artificially designed nanoarchitectures with target functionalities.

13.
Chemistry ; 21(17): 6375-80, 2015 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-25739331

RESUMO

A new dual soft-template system comprising the asymmetric triblock copolymer poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-b-P2VP-b-PEO) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) is used to synthesize hollow mesoporous silica (HMS) nanoparticles with a center void of around 17 nm. The stable PS-b-P2VP-b-PEO polymeric micelle serves as a template to form the hollow interior, while the CTAB surfactant serves as a template to form mesopores in the shells. The P2VP blocks on the polymeric micelles can interact with positively charged CTA(+) ions via negatively charged hydrolyzed silica species. Thus, dual soft-templates clearly have different roles for the preparation of the HMS nanoparticles. Interestingly, the thicknesses of the mesoporous shell are tunable by varying the amounts of TEOS and CTAB. This study provides new insight on the preparation of mesoporous materials based on colloidal chemistry.

14.
Small ; 10(10): 2096-107, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24610684

RESUMO

Nanoporous carbon particles with magnetic Co nanoparticles (Co/NPC particles) are synthesized by one-step carbonization of zeolitic imidazolate framework-67 (ZIF-67) crystals. After the carbonization, the original ZIF-67 shapes are preserved well. Fine magnetic Co nanoparticles are well dispersed in the nanoporous carbon matrix, with the result that the Co/NPC particles show a strong magnetic response. The obtained nanoporous carbons show a high surface area and well-developed graphitized wall, thereby realizing fast molecular diffusion of methylene blue (MB) molecules with excellent adsorption performance. The Co/NPC possesses an impressive saturation capacity for MB dye compared with the commercial activated carbon. Also, the dispersed magnetic Co nanoparticles facilitate easy magnetic separation.

15.
Chemistry ; 20(15): 4217-21, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24623613

RESUMO

Nanoporous carbon-cobalt-oxide hybrid materials are prepared by a simple, two-step, thermal conversion of a cobalt-based metal-organic framework (zeolitic imidazolate framework-9, ZIF-9). ZIF-9 is carbonized in an inert atmosphere to form nanoporous carbon-metallic-cobalt materials, followed by the subsequent thermal oxidation in air, yielding nanoporous carbon-cobalt-oxide hybrids. The resulting hybrid materials are evaluated as electrocatalysts for the oxygen-reduction reaction (ORR) and the oxygen-evolution reaction (OER) in a KOH electrolyte solution. The hybrid materials exhibit similar catalytic activity in the ORR to the benchmark, commercial, Pt/carbon black catalyst, and show better catalytic activity for the OER than the Pt-based catalyst.

16.
Chemistry ; 20(43): 13838-52, 2014 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-25251360

RESUMO

Tremendous development in the field of portable electronics and hybrid electric vehicles has led to urgent and increasing demand in the field of high-energy storage devices. In recent years, many research efforts have been made for the development of more efficient energy-storage devices such as supercapacitors, batteries, and fuel cells. In particular, supercapacitors have great potential to meet the demands of both high energy density and power density in many advanced technologies. For the last half decade, graphene has attracted intense research interest for electrical double-layer capacitor (EDLC) applications. The unique electronic, thermal, mechanical, and chemical characteristics of graphene, along with the intrinsic benefits of a carbon material, make it a promising candidate for supercapacitor applications. This Review focuses on recent research developments in graphene-based supercapacitors, including doped graphene, activated graphene, graphene/metal oxide composites, graphene/polymer composites, and graphene-based asymmetric supercapacitors. The challenges and prospects of graphene-based supercapacitors are also discussed.

17.
Chemistry ; 20(26): 7895-900, 2014 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-24788922

RESUMO

Nanoporous carbons (NPCs) have large specific surface areas, good electrical and thermal conductivity, and both chemical and mechanical stability, which facilitate their use in energy storage device applications. In the present study, highly graphitized NPCs are synthesized by one-step direct carbonization of cobalt-containing zeolitic imidazolate framework-67 (ZIF-67). After chemical etching, the deposited Co content can be completely removed to prepare pure NPCs with high specific surface area, large pore volume, and intrinsic electrical conductivity (high content of sp(2) -bonded carbons). A detailed electrochemical study is performed using cyclic voltammetry and galvanostatic charge-discharge measurements. Our NPC is very promising for efficient electrodes for high-performance supercapacitor applications. A maximum specific capacitance of 238 F g(-1) is observed at a scan rate of 20 mV s(-1) . This value is very high compared to previous works on carbon-based electric double layer capacitors.

18.
Sci Rep ; 14(1): 14427, 2024 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-38910140

RESUMO

The study presents a series of examples of magnetic nanoparticle systems designed for the diagnosis of viral diseases. In this interdisciplinary work, we describe one of the most comprehensive synthetic approaches for the preparation and functionalization of smart nanoparticle systems for rapid and effective RT-PCR diagnostics and isolation of viral RNA. Twelve different organic ligands and inorganic porous silica were used for surface functionalization of the Fe3O4 magnetic core to increase the number of active centres for efficient RNA binding from human swab samples. Different nanoparticle systems with common beads were characterized by HRTEM, SEM, FT-IR, XRD, XPS and magnetic measurements. We demonstrate the application of the fundamental models modified to fit the experimental zero-field cooling magnetization data. We discuss the influence of the nanoparticle shell parameters (morphology, thickness, ligands) on the overall magnetic performance of the systems. The prepared nanoparticles were tested for the isolation of viral RNA from tissue samples infected with hepatitis E virus-HEV and from biofluid samples of SARS-CoV-2 positive patients. The efficiency of RNA isolation was quantified by RT-qPCR method.


Assuntos
COVID-19 , Nanopartículas de Magnetita , RNA Viral , SARS-CoV-2 , Dióxido de Silício , Dióxido de Silício/química , Humanos , Nanopartículas de Magnetita/química , RNA Viral/genética , RNA Viral/isolamento & purificação , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/genética , COVID-19/diagnóstico , COVID-19/virologia , Propriedades de Superfície , Patologia Molecular/métodos , Viroses/diagnóstico , Viroses/virologia
19.
Chemistry ; 19(14): 4446-50, 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23447380

RESUMO

A new class of highly stable ferroelectric material, that is, a mesostructured SrTiO(3)/BaTiO(3) composite film, obtained by a surfactant-templated sol-gel method is reported. Due to the concave surface geometry and abundant hetero-interface between SrTiO(3) (ST) and BaTiO(3) (BT) phases, a large number of strains can be created in the composite film, thereby leading to dramatic enhancement of ferroelectric property (see scheme).

20.
Langmuir ; 29(9): 3061-72, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23387804

RESUMO

High-aspect-ratio titanate nanotubes (NT) and nanowires (NW) were produced by the hydrothermal conversion of TiO2 at 400 K. The titanate morphology was studied by high-resolution transmission electron microscopy (HRTEM). The formation of ordered titanate nanoobjects depended on the time of conversion. Shorter synthesis times favored hollow nanotube production while during prolonged treatment the thermodynamically more stable nanowires were formed. Titanate nanotubes and nanowires were decorated by Rh nanoparticles. The structure and stability of titanate nanocomposites were studied by thermal gravimetric (TG), X-ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS), Fourier transformed infrared spectroscopic (FTIR), and Raman spectroscopic methods. The nanowires preserve their structure up to 850 K, while the nanotubes start to recrystallize above 600 K. FTIR measurements showed that the water and hydroxyl content gradually decreased with increasing temperature in both cases. XPS data revealed the existence of high binding energy, highly dispersed Rh species on both supports. A small portion of Rh may participate in an ion exchange process. Support transformation phenomena were observed in Rh containing titanate nanowires and nanotubes. Rh decorated nanowires transform into the ß-TiO2 structure, whereas their pristine counterparts' recrystallize into anatase. The formation of anatase was dominant during the thermal annealing process in both acid treated and Rh decorated nanotubes. Transformation to anatase was enhanced in the presence of Rh. The average diameters Rh nanoparticles were 4.9 ± 1.4 and 2.8 ± 0.7 nm in the case of nanowires and nanotubes, respectively.


Assuntos
Nanotubos/química , Nanofios/química , Ródio/química , Titânio/química , Catálise , Propriedades de Superfície , Temperatura
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