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1.
J Hazard Mater ; 421: 126752, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352524

RESUMO

In this study, environmentally-friendly nanocomposite hydrogels were fabricated. These hydrogels consisted of semi-interpenetrating networks of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA), as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups, which were reinforced with different levels of graphene oxide particles (0.5, 1.5 or 3% wt). Field-emission electron scanning microscopy (FESEM) images indicated that the pore size of the nanocomposites decreased with increasing graphic oxide concentration. The presence of the graphic oxide increased the storage modulus and thermal stability of the nanocomposite hydrogels. The hydrogels had an adsorption capacity of 138 mg/g of a model cationic dye pollutant (methylene blue) after 250 min. Moreover, a reusability test showed that the adsorption capacity remained at around 90% after 9 cycles. Density functional theory (DFT) simulations suggested that the adsorption of methylene blue was mainly a result of π-π bonds, hydrogen bonds, and electrostatic interactions with graphene oxide. Our results indicated that the nanocomposite hydrogels fabricated in this study may be eco-friendly, stable, efficient, and reusable adsorbents for ionic pollutants in wastewater treatment.


Assuntos
Nanocompostos , Poluentes Químicos da Água , Resinas Acrílicas , Adsorção , Carboximetilcelulose Sódica , Corantes , Grafite , Cinética , Azul de Metileno , Águas Residuárias
2.
Talanta ; 237: 122924, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736661

RESUMO

During recent decades, we have witnessed a great improvement in the performance of aptamer-based sensors, specifically when aptamers are combined with new nanomaterials; as a platform for biosensors. The design of hollow carbon-based materials has also received a lot of attention due to its excellent properties in various applications. Herein, we aim at designing hierarchical porous Ni(OH)2 nanosheets on hollow N-doped carbon nanoboxes Ni(OH)2@N-C n-box). In this sense, we obtained the hollow N-C n-box skeletons from the Fe2O3 nanocubes template. The development of label-free electrochemical aptasensor was carried out using the covalently immobilizing NH2-functionalized aptamer on Ni(OH)2@N-C n-box as an efficient substrate. The Ni(OH)2@N-C n-box was characterized using scanning fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), transmission electron microscopes (TEM) and electron microscopy (FESEM). The electrochemical evaluations clarified the fact that a linear relationship exists between the alpha-fetoprotein (AFP) contents and the charge transfer resistance (Rct) (from 1 fg mL-1 to 100 ng mL-1) with a low detection limit of 0.3 fg mL-1. Moreover, regarding the aptasensor, the superior detection recoveries were experienced in real biological samples, illustrating its great detection performance and practical feasibility. Considering the aptasensor application, these studies showed that Ni(OH)2@N-C n-box possesses different enhanced electrochemical features, making it appropriate as an electrode material for aptasensor application.


Assuntos
Neoplasias , alfa-Fetoproteínas , Biomarcadores Tumorais , Carbono , Técnicas Eletroquímicas , Humanos , Hidróxidos , Níquel , Nitrogênio
3.
J Biomater Sci Polym Ed ; : 1-22, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34641773

RESUMO

In this study, a novel biopolymer based on poly(glycerol sebacic)-urethane (PGS-U) and its nanocomposites containing Cloisite@30B were synthesized by facile approach in which the crosslinking was created by aliphatic hexamethylene diisocyanate (HDI) at room temperature and 80 °C. Moreover, metronidazole and tetracycline drugs were selected as target drugs and loaded into PGSU based nanocomposites. A uniform and continuous microstructure with smooth surface is observed in the case of pristine PGS-U sample. The continuity of microstructure is observed in the case of all bionanocomposites. XRD result confirmed an intercalated morphology for PGSU containing 5 wt% of clay nanoparticles with a d-spacing 3.4 nm. The increment of nanoclay content up to 5%, the ultimate tensile stress and elastic modulus were obtained nearly 0.32 and 0.83 MPa, which the latter was more than eight-fold than that of pristine PGS-U. A sustained release for both dugs was observed by 200 h. The slowest and controlled drug release rate was determined in the case of PGSU containing 5 wt% clay and cured at 80 °C. A non-Fickian diffusion can be concluded in the case of tetracycline release via PGS-U/nanoclay bionanocomposites, while a Fickian process was detected in the case of metronidazole release by PGS-U/nanoclay bionanocomposites. As a result, the designed scaffold showed high flexibility, which makes it an appropriate option for utilization in the treatment of periodontal disease.

4.
Microchem J ; 170: 106718, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34381282

RESUMO

As a promising approach for serological tests, the present study aimed at designing a robust electrochemical biosensor for selective and quantitative analysis of SARS-CoV-2-specific viral antibodies. In our proposed strategy, recombinant SARS-CoV-2 spike protein antigen (spike protein) was used as a specific receptor to detect SARS-CoV-2-specific viral antibodies. In this sense, with a layer of nickel hydroxide nanoparticles (Ni(OH)2 NPs), the screen-printed carbon electrode (SPCE) surface was directly electrodeposited to ensure better loading of spike protein on the surface of SPCE. The differential pulse voltammetry (DPV) showed signals which were inversely proportional to the concentrations of the antibody (from 1 fg mL-1 L to 1 µg mL-1) via a specific and stable binding reaction. The assay was performed in 20 min with a low detection limit of 0.3 fg mL-1. This biodevice had high sensitivity and specificity as compared to non-specific antibodies. Moreover, it can be regarded as a highly sensitive immunological diagnostic method for SARS-CoV-2 antibody in which no labeling is required. The fabricated hand-held biodevice showed an average satisfactory recovery rate of ~99-103% for the determination of antibodies in real blood serum samples with the possibility of being widely used in individual serological qualitative monitoring. Also, the biodevice was tested using real patients and healthy people samples, where the results are already confirmed using the enzyme-linked immunosorbent assay (ELISA) procedure, and showed satisfactory results.

5.
J Pediatr Surg ; 56(7): 1192-1198, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33836847

RESUMO

INTRODUCTION: short bowel syndrome is marked by inadequate intestinal surface area to absorb nutrients. Current treatments are focused on medical management and surgical reconfiguration of the dilated intestine. We propose the use of spring-mediated distraction enterogenesis as a novel intervention to increase intestinal length. Given our previous success lengthening intestinal segments using springs with spring constant ~7 N/m that exerts 0.46 N or higher, we sought to determine the minimal force needed to lengthen porcine small intestinal segments, and to explore effects on intestine over time. METHODS: Juvenile Yucatan pigs underwent laparotomy with enterotomy to introduce nitinol springs intraluminally (n = 21 springs). Bowel segments (control, spring-distracted) were retrieved on post-operative day (POD) 7 and 14, and lengths measured. Thickness of cross-sectional intestinal layers were measured using H&E, and submucosal collagen fiber orientation measured using trichrome stained sections. RESULTS: all pigs survived to POD7 and 14. Spring constants of at least 2 N/m exerting a minimum force of 0.10 N significantly lengthened intestinal segments (p <0.0001). The stronger the spring force, the greater the induced thickness of various intestinal layers at POD7 and 14. Collagen fiber orientation was also more disordered because of stronger springs. CONCLUSION: a spring constant of approximately 2 N/m exerting 0.10 N and greater significantly lengthens intestinal segments and stimulates intestinal structural changes at POD7 and 14. This suggests a decreased force is capable of inducing spring-mediated distraction enterogenesis.


Assuntos
Síndrome do Intestino Curto , Dispositivos para Expansão de Tecidos , Animais , Estudos Transversais , Intestino Delgado/cirurgia , Jejuno/cirurgia , Síndrome do Intestino Curto/cirurgia , Suínos , Expansão de Tecido
6.
Mikrochim Acta ; 188(3): 105, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33651173

RESUMO

Severe acute respiratory syndrome SARS-CoV-2 has caused a global pandemic starting in 2020. Accordingly, testing is crucial for mitigating the economic and public health effects. In order to facilitate point-of-care diagnosis, this study aims at presenting a label-free electrochemical biosensor as a powerful nanobiodevice for SARS-CoV-2 spike protein detection. Utilizing the IgG anti-SARS-CoV-2 spike antibody onto the electrode surface as a specific platform in an ordered orientation through staphylococcal protein A (ProtA) is highly significant in fabricating the designed nanobiodevice. In this sense, the screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provide a large surface area in a very small space, was applied in order to increase the ProtA loading on the electrode surface. Accordingly, the sensitivity and stability of the sensing platform significantly increased. The electrochemical evaluations proved that there is a very good linear relationship between the charge transfer resistance (Rct) and spike protein contents via a specific binding reaction in the range 0.25 fg mL-1 to 1 µg mL-1. Moreover, the assay when tested with influenza viruses 1 and 2 was performed in 20 min with a low detection limit of 0.04 fg mL-1 for spike protein without any cross-reactivity. The designed nanobiodevice exhibited an average satisfactory recovery rate of ~ 97-103% in different artificial sample matrices, i.e., saliva, artificial nasal, and universal transport medium (UTM), illustrating its high detection performance and practicability. The nanobiodevice was also tested using real patients and healthy samples, where the results had been already obtained using the standard polymerase chain reaction (PCR) procedure, and showed satisfactory results. Graphical abstract.


Assuntos
Técnicas Biossensoriais/métodos , Teste para COVID-19/métodos , COVID-19/diagnóstico , Cobre/química , Técnicas Eletroquímicas/métodos , Nanoestruturas/química , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/análise , Anticorpos Antivirais/metabolismo , Eletrodos , Humanos , Imunoensaio/métodos , Imunoglobulina G/metabolismo , Ligação Proteica , SARS-CoV-2/metabolismo , Sensibilidade e Especificidade , Proteína Estafilocócica A/química , Propriedades de Superfície
7.
Talanta ; 223(Pt 1): 121700, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33303152

RESUMO

The design of hollow mesoporous carbon-based materials has attracted tremendous attention, due to their sizeable intrinsic cavity to load specific chemical and unique physical/chemical properties in various applications. Herein, we have established an effective strategy for the preparation of novel hollow carbon nanocapsules-based nitrogen-doped carbon nanofibers (CNCNF) with rosary-like structure. By embedding ultrafine hollow carbon nanocapsules into electrospun polyacrylonitrile (PAN) skeleton, the as-designed composite CNFs were carbonized into hierarchical porous CNFs, consisted of interconnected nitrogen-doped hollow carbon nanocapsules. Due to its individual structural properties and unique chemical composition, the performance of CNCNF was evaluated in aptasensor application via the detection of Pseudomonas aeruginosa (PA). Under optimized conditions, the aptasensor based on CNCNF has a detection limit of 1 CFU⋅mL-1 and a linear range from 101 CFU ⋅mL-1 to 107 CFU ⋅mL-1 (n = 3). Moreover, the designed aptasensor possesses high sensivity, high selectivity, low detection limit, and high reproducibility. These studies showed that the CNCNF material offers a wide variety of enhanced electrochemical features as an electrode material for aptasensor application.


Assuntos
Técnicas Biossensoriais , Nanocápsulas , Nanofibras , Carbono , Técnicas Eletroquímicas , Nitrogênio , Pseudomonas aeruginosa , Reprodutibilidade dos Testes
8.
Bioengineering (Basel) ; 7(4)2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33171760

RESUMO

Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common form of intestinal failure. Different strategies including parenteral nutrition and surgical lengthening to manage patients with short bowel syndrome are associated with high complication rates. More recently, self-expanding springs have been used to lengthen the small intestine using an intraluminal axial mechanical force, where this biomechanical force stimulates the growth and elongation of the small intestine. Differences in physical characteristics of patients with short bowel syndrome would require a different mechanical force-this is crucial in order to achieve an efficient and safe lengthening outcome. In this study, we aimed to predict the required mechanical force for each potential intestinal size. Based on our previous experimental observations and computational findings, we integrated our experimental measurements of patient biometrics along with mechanical characterization of the soft tissue into our numerical simulations to develop a series of computational models. These computational models can predict the required mechanical force for any potential patient where this can be advantageous in predicting an individual's tissue response to spring-mediated distraction enterogenesis and can be used toward a safe delivery of the mechanical force.

9.
Int J Biol Macromol ; 165(Pt A): 883-901, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33011268

RESUMO

Herein, for the first time, the adsorption mechanism of HCrO4- and CrO42- (as models of Cr(VI)) by bacterial cellulose (BC), polyaniline (PANI), and BC/PANI was performed using Density Functional Theory (DFT) in both acidic and neutral pH. For this purpose, three forms of neutral, partially (pp), and fully protonated (fp) were assumed for PANI in neutral and acidic media to elucidate the influence of pH. The results indicated that the formation of hydrogen bonds (H-bond) had the main contribution in the adsorption of CrO42- and HCrO4- onto both BC and PANI. Besides, the adsorption energy of PANI was nearly 3 times as much as BC in both acidic and neutral pH. The design of the BC/PANI complex improved the stability of PANI by increasing in HOMO-LUMO energy gap from 1.1 eV to 1.97 eV. The establishment of more H-bonds, and the appearance of two different types of H-bonds, O⋯H and N⋯H, and their smaller distances (average 1.5 Å), were observed in HCrO4-/BC-fp-PANI complexes, while one type of hydroxyl H-bond (average 2 Å) was detected in CrO42-/BC-pp-PANI. It proved the adsorption of Cr(VI) is more favorable in acidic pH. The small value of charge transferred (-0.001-0.01) showed that interfacial interaction was governed by physisorption.


Assuntos
Compostos de Anilina/química , Celulose/química , Cromo/isolamento & purificação , Poluentes Químicos da Água/química , Adsorção/efeitos dos fármacos , Cromo/toxicidade , Simulação por Computador , Teoria da Densidade Funcional , Humanos , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
10.
Carbohydr Polym ; 250: 116903, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33049830

RESUMO

In this work, the structure-property relationship was evaluated in the synthesis of bacterial cellulose (BC)/polyaniline (PANI) nanocomposite aerogels in terms of both experimental and density functional theory (DFT) simulation. The molarity of HCl solution (0.01 and 0.5 M) and the presence/absence of cetyltrimethylammonium bromide (CTAB) were the main parameters of synthesis conditions. DFT simulation showed that the formation of hydrogen bonds governed interaction between BC and PANI, and PANI had more tendency to BC than that of CTAB at 0.5 M. It was confirmed by the formation of shorter hydrogen bonds between BC and protonated PANI at 0.5 M. Regarding this fact, prepared samples at 0.5 M of HCl solution and the presence of CTAB experienced higher storage modulus and electrical conductivity by 2000 Pa and 4 order of magnitude than those of lower molarity (0.01 M). These findings were in accordance with simulation outcomes.


Assuntos
Compostos de Anilina/química , Bactérias/metabolismo , Celulose/química , Teoria da Densidade Funcional , Condutividade Elétrica , Nanocompostos/química , Tensoativos/química , Ligação de Hidrogênio , Polimerização , Propriedades de Superfície
11.
Cancer Cell Int ; 20: 426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32905102

RESUMO

Background: The methylation of the CpG islands of the LINE-1 promoter is a tight control mechanism on the function of mobile elements. However, simultaneous quantification of promoter methylation and transcription of LINE-1 has not been performed in progressive stages of colorectal cancer. In addition, the insertion of mobile elements in the genome of advanced adenoma stage, a precancerous stage before colorectal carcinoma has not been emphasized. In this study, we quantify promoter methylation and transcripts of LINE-1 in three stages of colorectal non-advanced adenoma, advanced adenoma, and adenocarcinoma. In addition, we analyze the insertion of LINE-1, Alu, and SVA elements in the genome of patient tumors with colorectal advanced adenomas. Methods: LINE-1 hypomethylation status was evaluated by absolute quantitative analysis of methylated alleles (AQAMA) assay. To quantify the level of transcripts for LINE-1, quantitative RT-PCR was performed. To find mobile element insertions, the advanced adenoma tissue samples were subjected to whole genome sequencing and MELT analysis. Results: We found that the LINE-1 promoter methylation in advanced adenoma and adenocarcinoma was significantly lower than that in non-advanced adenomas. Accordingly, the copy number of LINE-1 transcripts in advanced adenoma was significantly higher than that in non-advanced adenomas, and in adenocarcinomas was significantly higher than that in the advanced adenomas. Whole-genome sequencing analysis of colorectal advanced adenomas revealed that at this stage polymorphic insertions of LINE-1, Alu, and SVA comprise approximately 16%, 51%, and 74% of total insertions, respectively. Conclusions: Our correlative analysis showing a decreased methylation of LINE-1 promoter accompanied by the higher level of LINE-1 transcription, and polymorphic genomic insertions in advanced adenoma, suggests that the early and advanced polyp stages may host very important pathogenic processes concluding to cancer.

12.
Int J Biol Macromol ; 152: 57-67, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32057868

RESUMO

Herein, polyaniline (PANI) with tuning morphology was in-situ synthesized within bacterial cellulose (BC)/silver nanoparticles hydrogels (AgNPs) that were prepared by green hydrothermal reduction method in different molarity of 0.01 and 0.25 of HCl solution along with the presence of polyethylene glycol (PEG). The synthesis of PANI in the presence of PEG in 0.01 M HCl led to the formation of rose-like morphology within nanocomposite aerogels with a size of 1.5-5.2 µm. All aerogels had the porosity and shrinkage of higher than 80% and lower than 10%, respectively. Rheology results showed a higher value of storage modulus (G') than that of loss modulus (G″) for all samples over the whole frequency regime. It confirmed by the loss factor (tan δ) value of less than 1 for all hydrogel samples. The synthesis of PANI within BC/Ag in 0.25 M of HCl solution resulted in a substantial rise of G' to nearly 1.5 × 104 Pa that was one order of magnitude higher than that of other hydrogels. However, the synthesis condition of PANI did not influence the antibacterial activity. In spite of unfavorable cell attachment onto nanocomposite aerogels, the cell proliferation increased steadily over the whole period of incubation.


Assuntos
Compostos de Anilina/química , Compostos de Anilina/farmacologia , Bactérias/química , Celulose/química , Nanopartículas Metálicas/química , Prata/química , Engenharia Tecidual , Antibacterianos/química , Antibacterianos/farmacologia , Géis , Teste de Materiais , Modelos Moleculares , Conformação Molecular , Polietilenoglicóis/química , Reologia
13.
Talanta ; 210: 120696, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987185

RESUMO

In this study, for the first time, we reported a fast and facile three-step in situ strategy for direct controllable growth of the Co3(BTC)2 MOFs thin films on the GCE, through the rapid conversion of the electrodeposited Co(OH)2 nano-flakes on rGO/GCE, to crystalline rectangular bar-shape structures of MOFs. X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and elemental mapping analysis used to the structural and morphological characterization of the well-synthesized MOFs. The as-prepared Co3(BTC)2 MOFs were used to construct a non-enzymatic sensing platform for determining the glucose in alkaline solution. The designed electrode demonstrated two wide linear dynamic range of 1 µM - 0.33 mM and 0.33 mM-1.38 mM with high sensitivity of 1792 µA mM-1 cm-2 and 1002 µA mM-1 cm-2, respectively, good repeatability and reproducibility, high selectivity against interference species and good poisoning resistance against chloride ions and a low detection limit of 0.33 µM (S/N = 3). Finally, the application of the proposed sensor for the determination of glucose in the human blood serum samples was investigated and results showed excellent recoveries, which confirmed that the fabricated sensor can act as a reliable and sensitive platform for biological and clinical samples analysis.


Assuntos
Técnicas Biossensoriais , Carbono/química , Cobalto/química , Técnicas Eletroquímicas , Glucose/análise , Hidróxidos/química , Estruturas Metalorgânicas/química , Eletrodos , Grafite/síntese química , Grafite/química , Tamanho da Partícula , Propriedades de Superfície
14.
J Mech Behav Biomed Mater ; 101: 103425, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541857

RESUMO

Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common subset of intestinal failure. Spring distraction uses an intraluminal axial mechanical force to stimulate the growth and elongation of the small intestine. The tissue close to the distracted intestinal segment may also experience signaling to grow. In this study we examined the effects of distraction enterogenesis at different post-operative days on the thickness of small intestinal layers in the intestine proximal and distal to the distracted segment, as well as how the submucosal collagen fibers were reoriented. It was observed that not only different layers of intestine wall in distracted segment showed thickening due to the applied mechanical force but also adjacent tissues in both distal and proximal directions were impacted significantly where they showed thickening as well. The orientation of collagen fibers in submucosa layer was also significantly impacted due to the mechanical force in both distracted and adjacent tissue. The effect of the applied mechanical force on the main distracted tissue and the radial growth of the adjacent tissue strongly suggest actions of paracrine signaling.


Assuntos
Colágeno/metabolismo , Intestino Delgado/citologia , Intestino Delgado/metabolismo , Fenômenos Mecânicos , Transdução de Sinais , Animais , Fenômenos Biomecânicos , Feminino , Intestino Delgado/cirurgia , Suínos
15.
J Mech Behav Biomed Mater ; 101: 103413, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518947

RESUMO

During recent years, distraction enterogenesis has been extensively studied as a treatment for short bowel syndrome, which is the most common cause of intestinal failure. Although different strategies such as parenteral nutrition and surgical lengthening have been used to manage the difficulties that patients with SBS deal with, these treatments are associated with high complication rates. Distraction enterogenesis uses mechanical force to increase the length and stimulate growth of the small intestine. In this study we combine in vivo experiments with computational modeling to explore the biomechanics of spring dependent distraction enterogenesis. We hypothesize that the self-expanding spring provides mechanical force for elastic tissue lengthening and triggers cellular proliferation. The additional growth of the intestine suggests signaling between mechanical stress and tissue response. We developed a computational modeling platform to test the correlation of applied mechanical force and tissue growth. We further validated our computational models with experimental measurements using spring-mediated distraction enterogenesis in a porcine model. This modeling platform can incorporate patient biometrics to estimate an individual's tissue response to spring mediated distraction enterogenesis.


Assuntos
Intestino Delgado/cirurgia , Fenômenos Mecânicos , Expansão de Tecido/instrumentação , Animais , Fenômenos Biomecânicos , Proliferação de Células , Elasticidade , Intestino Delgado/citologia , Suínos
16.
J Neurosci ; 39(41): 8079-8088, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31434689

RESUMO

Here, we investigated processing by receptive fields, a fundamental property of neurons in the visual system, using fMRI and population receptive field (pRF) mapping in 20 human females with monosomic Turner syndrome (TS) (mean age, 10.3 ± 2.0 years) versus 22 age- and sex-matched controls (mean age, 10.4 ± 1.9 years). TS, caused by X-chromosome haploinsufficiency in females, is associated with well-recognized effects on visuospatial processing, parieto-occipital cortical anatomy, and parietal lobe function. However, it is unknown whether these effects are related to altered brain structure and function in early visual areas (V1-V3) versus downstream parietal cortical regions. Results show that girls with TS have the following: (1) smaller volume of V1-V3, (2) lower average pRF eccentricity in early visual areas, and (3) sparser pRF coverage in the periphery of the visual field. Further, we examined whether the lower volume of early visual areas, defined using retinotopic mapping, in TS is due to smaller surface area or thinner cortex. Results show that girls with TS had a general reduction in surface area relative to controls in bilateral V1 and V2. Our data suggest the possibility that the smaller cortical surface area of early visual areas in girls with TS may be associated with a lower number of neurons, which in turn, leads to lesser coverage of the peripheral visual field compared to controls. These results indicate that X-chromosome haploinsufficiency associated with TS affects the functional neuroanatomy of early visual areas, and suggest that investigating pRFs in TS may shed insights into their atypical visuospatial processing.SIGNIFICANCE STATEMENT Turner syndrome is caused by the absence of one of the two X-chromosomes in females. Using functional neuroimaging and population receptive field mapping, we find that chromosome dosage variation (X-monosomy) associated with Turner syndrome affects the functional neuroanatomy of the visual cortex. Specifically, girls with Turner syndrome have smaller early visual areas that provide lesser coverage of the peripheral visual field compared with healthy controls. Our observations provide compelling evidence that the X-chromosome affects not only parietal cortex, as described in previous studies, but also affects early visual areas. These findings suggest a paradigm change in understanding the effect of X-monosomy on the development of visuospatial abilities in humans.


Assuntos
Cromossomos Humanos X/genética , Síndrome de Turner/fisiopatologia , Córtex Visual/crescimento & desenvolvimento , Córtex Visual/fisiopatologia , Adolescente , Mapeamento Encefálico , Contagem de Células , Criança , Feminino , Haploinsuficiência/genética , Humanos , Imageamento por Ressonância Magnética , Neurônios , Desempenho Psicomotor , Síndrome de Turner/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Testes de Campo Visual , Campos Visuais
17.
Nanoscale ; 11(26): 12655-12671, 2019 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-31237600

RESUMO

The planned design of nanocomposites combined with manageable production processes, which can offer controllability over the nanomaterial structure, promises the practical applications of functional nanomaterials. Hollow core-shell nanostructure architectures represent an emerging category of advanced functional nanomaterials, whose benefits derived from their notable properties may be hampered by complicated construction processes, especially in the sensing domain. In this regard, we designed a highly porous three-dimensional array of hierarchical hetero Cu(OH)2@CoNi-LDH core-shell nanotubes via a quick, very simple, green, and highly controllable three-step in situ method; they were directly grown on a glassy carbon electrode to fabricate an enzyme-free glucose sensor. By virtue of an open structure containing a hollow conductive core and a highly porous catalytic active shell, which were both synthesized by the in situ method, hierarchical self-standing core-shell nanotubes were obtained. They provided an enlarged active surface area, highly accessible catalytic sites, faster electron transfer, effortless electrolyte ion diffusion pathways, and structural stability, thus leading to improved electrocatalytic performances and durability towards glucose electro-oxidation; this was reflected by the fast sensitive responses of the as-prepared sensor towards glucose and comparable results with the automatic biochemistry analyzer used in hospitals in real sample analysis. Moreover, the commercialization capability of the proposed sensor was evaluated analogously by directly grown hierarchical Cu(OH)2@CoNi-LDH core-shell nanotubes on graphite screen-printed exposable electrodes through a 3-step in situ method. Cu(OH)2@CoNi-LDH NS-NTs/GSPE showed accurate responses towards glucose, lack of any fouling effect of the electrocatalyst layer over a wide range of glucose concentrations and comparable results with that of a commercial glucometer in real sample analysis, which revealed high sensitivity, selectivity, and durability of the low-cost on-site sensor as well as excellent versatility of its fabrication method. Thus, the self-supporting, cost-affordable, facile, and fast electrode fabrication procedure with versatility and meticulous structural controllability presented in this research provides a new architecture for the advancement of high-performance electrochemical sensors and miniaturized detection devices.

18.
Netw Neurosci ; 3(1): 157-172, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30793079

RESUMO

Accelerated intermittent theta burst stimulation (aiTBS) is a noninvasive neurostimulation technique that shows promise for improving clinical outcome in patients suffering from treatment-resistant depression (TRD). Although it has been suggested that aiTBS may evoke beneficial neuroplasticity effects in neuronal circuits, the effects of aiTBS on brain networks have not been investigated until now. Fifty TRD patients were enrolled in a randomized double-blind sham-controlled crossover trial involving aiTBS, applied to the left dorsolateral prefrontal cortex. Diffusion-weighted MRI data were acquired at each of three time points (T1 at baseline; T2 after the first week of real/sham aiTBS stimulation; and T3 after the second week of treatment). Graph analysis was performed on the structural connectivity to examine treatment-related changes in the organization of brain networks. Changes in depression severity were assessed using the Hamilton Depression Rating Scale (HDRS). Baseline data were compared with 60 healthy controls. We observed a significant reduction in depression symptoms over time (p < 0.001). At T1, both TRD patients and controls exhibited a small-world topology in their white matter networks. More importantly, the TRD patients demonstrated a significantly shorter normalized path length (p AUC = 0.01), and decreased assortativity (p AUC = 0.035) of the structural networks, compared with the healthy control group. Within the TRD group, graph analysis revealed a less modular network configuration between T1 and T2 in the TRD group who received real aiTBS stimulation in the first week (p < 0.013). Finally, there were no significant correlations between changes on HDRS scores and reduced modularity. Application of aiTBS in TRD is characterized by reduced modularity, already evident 4 days after treatment. These findings support the potential clinical application of such noninvasive brain stimulation in TRD.

19.
J Laparoendosc Adv Surg Tech A ; 29(2): 267-271, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30207836

RESUMO

BACKGROUND: Pectus excavatum and carinatum are two of the most commonly observed chest wall deformities in pediatrics. The standard diagnostic evaluation for these conditions includes either chest radiograph (CXR) or computed tomography (CT). Our research aims to develop a novel and reliable way of quantifying chest wall deformities in the clinic setting without radiation exposure. METHODS: Using a handheld structured light scanner, we created three-dimensional (3D) models of patients with chest wall deformities through an IRB-approved protocol. Raters from a variety of backgrounds were then asked to take measurements based on the 3D model utilizing commercially available 3D graphical software. The standard deviation of the measurements and intraclass correlation coefficient (ICC) were then calculated to quantify inter-rater reliability. RESULTS: Sixty patients with pectus excavatum (Haller index range 2.0-6.38) and pectus carinatum were enrolled and imaged in our outpatient clinic using a structured light scanner. Five patients were used to verify interuser reliability. The standard deviation of all the measurements was 2.2 mm. The ICC for absolute agreement was 0.99139, with 1.0 being perfect correlation. CONCLUSION: Structured light scanners provide an alternative approach to quantifying chest wall deformities in pediatric patients without radiation exposure. Our method is highly reliable, even among users with minimal image processing or 3D modeling experience. Our protocol can potentially be used to track treatment progress in children with chest wall deformities.


Assuntos
Tórax em Funil/diagnóstico por imagem , Imageamento Tridimensional/métodos , Imagem Óptica/métodos , Pectus Carinatum/diagnóstico por imagem , Parede Torácica/anormalidades , Parede Torácica/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Imagem Óptica/instrumentação , Reprodutibilidade dos Testes , Adulto Jovem
20.
Carbohydr Polym ; 201: 228-235, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30241815

RESUMO

In this work, in-situ biosynthesized bacterial cellulose (BC) /multiwall carbon nanotubes (MWCNTs) nanocomposite hydrogels converted to the conductive nanocomposite aerogels via the supercritical CO2 method. A low percolation threshold value of 0.0041 (volume concentration) predicted for BC/MWCNTs nanocomposite aerogels by the proposed modified model. The piezoresistive behavior of the nanocomposite aerogel at percolation threshold, evaluated in tension mode. The strain sensing outcomes revealed a linear trend during loading until a critical strain, afterward began to decline with further increasing of strain. Moreover, by applying loading unloading cyclic tension for 10 times at two different strain amplitudes (2% and 8%), the variation of relative resistance was different. This attributed to the rearrangement of MWCNTs at high strain condition. The gauge factor of 21 and response time of 390 ms obtained for flexible lightweight strain sensor. The fabricated strain sensor utilized to monitor human detection motion.

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