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1.
Small ; : e2406249, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39221532

RESUMO

Aqueous Zn-ion batteries (AZIBs) are promising energy-storage devices owing to their exceptional safety, long cycle life, simple production, and high storage capacity. Manganese oxides are considered potential cathode materials for AZIBs, primarily because of their safety, low cost, simple synthesis, and high storage capacity. However, MnO2-based cathodes tend to deteriorate structurally during long-term cycling, which reduces their reversible capacity. In this study, an advanced α-MnO2@SnO2 nanocomposite via facile hydrothermal synthesis is developed. The synergistic effects of lattice disorder and increased electron conductivity in the α-MnO2@SnO2 nanocomposite mitigate structural degradation and enhance the overall electrochemical performance. The nanocomposite exhibits a high reversible capacity of 347 mAh g-1 at a current density of 100 mA g-1 after 50 cycles. Furthermore, it exhibits excellent rate performance and stable capacity even after 1000 cycles, maintaining a capacity of 78 mAh g-1 at a high current density of 5 A g-1. This excellent electrochemical performance is attributed to the reversible Zn intercalation in α-MnO2@SnO2 nanocomposites due to the increased structural stability and fast ion/electron exchange caused by the distortion of the tunnel structure, on the basis of various ex situ experiments, density functional theory calculations, and electrochemical characterizations.

2.
Knee Surg Sports Traumatol Arthrosc ; 31(1): 178-184, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35737009

RESUMO

PURPOSE: The purpose of this study was to investigate the outcomes of conservative treatment for recurrent shoulder dislocation without subjective apprehension, despite the presence of a Bankart lesion or glenoid defect. METHODS: A retrospective analysis was performed for 92 patients with recurrent shoulder dislocation treated with conservative treatment due to negative apprehension between 2009 and 2018. The failure of the conservative treatment was defined as a dislocation or subluxation episode or subjective feeling of instability based on a positive apprehension. The Kaplan-Meier method was used to estimate failure rates over time, and a receiver operating characteristic (ROC) curve was constructed to determine a cut-off value for a glenoid defect. The clinical outcomes were compared between patients who completed conservative treatment without recurrence of instability (Group A) and those who failed and subsequently underwent surgical treatment (Group B) using shoulder functional scores and sports/recreation activity level. RESULTS: This retrospective study included 61 of 92 eligible patients with recurrent shoulder dislocation. Among the 61 patients, conservative treatment failed in 46 (75.4%) over the 2-year study period. The cut-off value for a glenoid defect was 14.4%. The association between glenoid defect size (≥ 14.4% or as a continuous variable) and survival was statistically significant (p = 0.039 and p < 0.001, respectively). The mean glenoid defect size in Group B increased from 14.6 ± 3.0% to 17.3 ± 3.1% (p < 0.001), and clinical outcomes for Group A were inferior to those for Group B at the 24-month follow-up. CONCLUSIONS: Conservative treatment for recurrent shoulder dislocation in patients without subjective apprehension showed a high failure rate during the study period, especially if the glenoid defect was ≥ 14.4% in size. Despite clinical improvement in patients who completed conservative treatment without recurrence, functional outcome scores and sport/recreation activity levels were better in the patients who underwent arthroscopic Bankart repair. Therefore, for recurrent anterior shoulder instability, even without subjective apprehension, surgical treatment is warranted over conservative treatment. LEVEL OF EVIDENCE: Level IV.


Assuntos
Instabilidade Articular , Luxação do Ombro , Articulação do Ombro , Humanos , Luxação do Ombro/diagnóstico , Luxação do Ombro/cirurgia , Articulação do Ombro/cirurgia , Estudos Retrospectivos , Instabilidade Articular/cirurgia , Instabilidade Articular/etiologia , Tratamento Conservador , Artroscopia/métodos , Exame Físico , Recidiva
3.
Arch Orthop Trauma Surg ; 143(6): 3251-3258, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36369526

RESUMO

INTRODUCTION: To investigate (1) the prevalence of "hidden lesions" and "non-hidden lesions" of subscapularis tendon tears requiring repair during arthroscopic examination that would be missed by a 30° arthroscope, but could be identified by a 70° arthroscope, from the standard posterior portal and (2) the correlation of preoperative internal rotation weakness and findings of magnetic resonance imaging (MRI) indicating hidden lesions. MATERIALS AND METHODS: We retrospectively examined 430 patients who underwent arthroscopic subscapularis repair between was initially nonvisible with a 30° arthroscope but became visible only with a 70° arthroscope from the standard posterior portal. The preoperative and intraoperative findings of the hidden lesion group (n = 82) were compared with those of the non-hidden lesion group (n = 348). 2016 and 2020. A hidden lesion was defined as a subscapularis tendon tear requiring repair that preoperative internal rotation weakness was assessed using the modified belly-press test. Preoperative MR images were reviewed using a systemic approach. RESULTS: The prevalence of hidden lesions was 19.1% (82/430). No significant difference was found in preoperative internal rotation weakness between the groups. Preoperative MRI showed a significantly lower detection rate in the hidden lesion group than in the non-hidden group (69.5% vs. 84.8%; P = 0.001). The hidden lesions were at a significantly earlier stage of subscapularis tendon tears than the non-hidden lesions, as revealed by the arthroscopic findings (Lafosse classification, degree of retraction; P = 0.003 for both) and MR findings (muscle atrophy, fatty infiltration; P = 0.001, P = 0.005, respectively). CONCLUSIONS: Among the subscapularis tears requiring repair, 19.1% could be identified by a 70° arthroscope, but not by a 30° arthroscope, through the posterior portal. The hidden lesions showed a significantly lower detection rate on preoperative MRI than the non-hidden lesions. Thus, for subscapularis tears suspected on preoperative physical examination, the 70° arthroscope would be helpful to avoid a misdiagnosis.


Assuntos
Lesões do Manguito Rotador , Traumatismos dos Tendões , Humanos , Manguito Rotador/cirurgia , Traumatismos dos Tendões/diagnóstico por imagem , Traumatismos dos Tendões/cirurgia , Estudos Retrospectivos , Artroscopia/métodos , Músculo Esquelético/patologia , Imageamento por Ressonância Magnética , Lesões do Manguito Rotador/diagnóstico por imagem , Lesões do Manguito Rotador/cirurgia
4.
Inorg Chem ; 60(15): 11147-11153, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34279910

RESUMO

The battery safety and cost remain major challenges for developing next-generation rechargeable batteries. All-solid-state sodium (Na)-ion batteries are a promising option for low-cost as well as safe rechargeable batteries by using abundant resources and solid electrolytes. However, the operation of solid-state batteries is limited due to the low ionic conductivity of solid electrolytes. Therefore, it is essential to develop new compounds that feature a high ionic conductivity and chemical stability at room temperature. Herein, we report a potassium-substituted sodium superionic conductor solid electrolyte, Na3-xKxZr2Si2PO12 (0 ≤ x ≤ 0.2), that exhibits an ionic conductivity of 7.734 × 10-4 S/cm-1 at room temperature, which is more than 2 times higher than that of the undoped sample. The synchrotron powder diffraction patterns with Rietveld refinements revealed that the substitution of large K-ions resulted in an increased unit cell volume, widened the Na diffusion channel, and shortened the Na-Na distance. Our work demonstrates that substituting a larger cation on the Na site effectively widens the ion diffusion channel and consequently increases the bulk ionic conductivity. Our findings will contribute to improving the ionic conductivity of the solid electrolytes and further developing safe next-generation rechargeable batteries.

5.
Sensors (Basel) ; 21(5)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668114

RESUMO

Planar-type resistance temperature detectors (P-RTDs) were fabricated via fused deposition modeling by dual nozzle extrusion. The temperature-sensing element of the fabricated sensor was printed with electrically conductive polylactic acid/carbon black (PLA/CB) composite, while the structural support was printed with a PLA insulator. The temperature-dependent resistivity change of PLA/CB was evaluated for different stacking sequences of PLA/CB layers printed with [0°/0°], [-45°/45°], and [0°/90°] plies. Compared to a PLA/CB filament used as 3D printing source material, the laminated structures exhibited a response over 3 times higher, showing a resistivity change from -10 to 40 Ω∙cm between -15 and 50 °C. Then, using the [0°/90°] plies stacking sequence, a P-RTD thermometer was fabricated in conjunction with a Wheatstone bridge circuit for temperature readouts. The P-RTD yielded a temperature coefficient of resistance of 6.62 %/°C with high stability over repeated cycles. Fabrication scalability was demonstrated by realizing a 3 × 3 array of P-RTDs, allowing the temperature profile detection of the surface in contact with heat sources.

6.
Mol Ther ; 27(2): 342-354, 2019 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-30424954

RESUMO

Radiotherapy has been a central part in curing non-small cell lung cancer (NSCLC). However, it is possible that not all of the tumor cells are destroyed by radiation; therefore, it is important to effectively control residual tumor cells that could become aggressive and resistant to radiotherapy. In this study, we aimed to investigate the molecular mechanism of decreased NSCLC radioresistance by low-dose radiation (LDR) pretreatment. The results indicated that miR-30a and miR-30b, which effectively inhibited plasminogen activator inhibitor-1 (PAI-1), were overexpressed by treatment of LDR to NSCLC cells. Phosphorylation of Akt and ERK, the downstream survival signals of PAI-1, was decreased by PAI-1 inhibition. Reduced cell survival and epithelial-mesenchymal transition by PAI-1 inhibition were confirmed in NSCLC cells. Moreover, in vivo orthotopic xenograft mouse models with 7C1 nanoparticles to deliver miRNAs showed that tumor growth and aggressiveness were efficiently decreased by LDR treatment followed by radiotherapy. Taken together, the present study suggested that PAI-1, whose expression is regulated by LDR, was critical for controlling surviving tumor cells after radiotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , MicroRNAs/metabolismo , Células A549 , Animais , Apoptose/genética , Apoptose/fisiologia , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/genética , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Nanopartículas/química , Reação em Cadeia da Polimerase em Tempo Real , Cicatrização/genética , Cicatrização/fisiologia
7.
J Wound Care ; 29(5): 289-294, 2020 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-32421480

RESUMO

OBJECTIVE: Studies have shown that ozone in an aqueous state on a scar, because of its antibacterial effect, aids wound-healing. This study aimed to compare the pain control effect, based on the time to wound healing, of using a sitz bath with ozonised water with that of using a sitz bath with ordinary tap water in patients who have had a haemorrhoidectomy. METHOD: Patients were divided into two equal-sized groups: Group O used a sitz bath with ozonised water after haemorrhoidectomy and patients in Group T used a sitz bath with ordinary tap water. Different concentrations (1ppm, 2ppm and 4ppm) of ozonized water were tested to determine their bactericidal activities. Pain levels were measured using the Visual Analogue Scale (ranging from 0-10 where 0 is 'no pain' and 10 is 'unbearable pain'), on days two, three and seven. Cohort analysis was retrospectively performed on the prospectively randomised collected data for this study. RESULTS: A total of 80 patients participated in the study. No case showed any signs of bacterial growth. On postoperative day seven, patients in Group O showed a significantly lower pain level than those in Group T (1.35±0.48 versus 2.40±0.9; p<0.001). The time needed for anus scars to be completely healed was significantly shorter for Group O than that for Group T (2.75±0.63 weeks versus 3.85±0.80 weeks; p<0.001). CONCLUSION: The results of this study showed that using a sitz bath with ozonised water reduced pain and accelerated healing in patients who have had a haemorrhoidectomy.


Assuntos
Banhos , Hemorroidectomia , Dor Pós-Operatória/terapia , Ferida Cirúrgica , Cicatrização , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ozônio , Fatores de Tempo , Resultado do Tratamento
8.
Sensors (Basel) ; 20(24)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302508

RESUMO

G nerve agents are colorless, odorless, and lethal chemical warfare agents (CWAs). The threat of CWAs, which cause critical damage to humans, continues to exist, e.g., in warfare or terrorist attacks. Therefore, it is important to be able to detect these agents rapidly and with a high degree of sensitivity. In this study, a surface acoustic wave (SAW) array device with three SAW sensors coated with different sensing materials and one uncoated sensor was tested to determine the most suitable material for the detection of nerve agents and related simulants. The three materials used were polyhedral oligomeric silsesquioxane (POSS), 1-benzyl-3-phenylthiourea (TU-1), and 1-ethyl-3-(4-fluorobenzyl) thiourea (TU-2). The SAW sensor coated with the POSS-based polymer showed the highest sensitivity and the fastest response time at concentrations below the median lethal concentration (LCt50) for tabun (GA) and sarin (GB). Also, it maintained good performance over the 180 days of exposure tests for dimethyl methylphosphonate (DMMP). A comparison of the sensitivities of analyte vapors also confirmed that the sensitivity for DMMP was similar to that for GB. Considering that DMMP is a simulant which physically and chemically resembles GB, the sensitivity to a real agent of the sensor coated with POSS could be predicted. Therefore, POSS, which has strong hydrogen bond acid properties and which showed similar reaction characteristics between the simulant and the nerve agent, can be considered a suitable material for nerve agent detection.


Assuntos
Substâncias para a Guerra Química , Agentes Neurotóxicos , Materiais Inteligentes , Substâncias para a Guerra Química/análise , Humanos , Polímeros , Sarina
9.
BMC Endocr Disord ; 19(1): 52, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31113413

RESUMO

BACKGROUND: Hypothyroidism, one of the prevalent endocrine disorders worldwide, has a broad spectrum of clinical manifestations, from an asymptomatic condition to myxedema coma. Although the majority of patients with hypothyroidism have minor clinical symptoms, which are recovered with levothyroxine treatment, some patients occasionally do experience fatal complications. Here we report, for the first time, the case of a patient who had hypothyroidism with simultaneous occurrence of rhabdomyolysis with acute kidney injury, moderate pericardial effusion, and sudden sensorineural hearing loss. CASE PRESENTATION: A 57-year-old man with a previous history of dyslipidemia and untreated hypothyroidism was admitted to the hospital due to shortness of breath, lethargy, lower extremity discomfort, and unilateral hearing loss. Laboratory results revealed rhabdomyolysis with acute kidney injury and severe hypothyroidism. We detected cardiomegaly without lung parenchymal infiltration on chest radiography and moderate pericardial effusion on transthoracic echocardiography. We performed pure tone audiometry and identified profound unilateral sensorineural hearing loss. Aggressive fluid resuscitation, levothyroxine treatment, and systemic and intratympanic steroid therapy alleviated the patient's severe hypothyroidism, rhabdomyolysis, and pericardial effusion; however, sensorineural hearing loss was not fully recovered. CONCLUSIONS: Early recognition of life-threatening complications is important in patients with severe hypothyroidism to prevent adverse outcomes. This case suggests that hypothyroidism should be considered in patients who have rhabdomyolysis with acute kidney disease and pericardial effusion. Moreover, sudden sensorineural hearing loss should be kept in mind as a rare complication of hypothyroidism.


Assuntos
Perda Auditiva Neurossensorial/patologia , Hipotireoidismo/patologia , Derrame Pericárdico/patologia , Rabdomiólise/patologia , Perda Auditiva Neurossensorial/complicações , Humanos , Hipotireoidismo/complicações , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/complicações , Prognóstico , Rabdomiólise/complicações
10.
Nano Lett ; 18(1): 475-481, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29235876

RESUMO

Nanostructural design renders several breakthroughs for the construction of high-performance materials and devices including energy-storage systems. Although attempts made toward electrode engineering have improved the existing drawbacks, nanoengineering is still hindered by some issues. To achieve practical applications of lithium-sulfur (Li-S) batteries, it is difficult to attain a high areal capacity with stable cycling. Physical encapsulation via nanostructural design not only can resolve the issue of lithium polysulfide dissolution during the electrochemical cycling, but also can offer significant contact resistance, which in turn can decrease the kinetics, particularly at a high sulfur loading. Thus, we demonstrate an electrospun carbon nanofiber (CNF) matrix for a sulfur cathode. This simple design enables a high mass loading of 10.5 mg cm-2 with a high specific capacity and stable cycling. The CNF-sulfur complex can deliver a high areal capacity of greater than 7 mAh cm-2, which is related to the excellent electrical conductivity of one-dimensional species. Moreover, we have observed that the reacted sulfur species have adhered well to the junction of the CNF network with specific wetting angles, which are induced by the cohesive force between the narrow gaps in the matrix that trapped the viscous polysulfides during cycling. The results of this study open new avenues for the design of high-areal-capacity Li-S batteries.

11.
Small ; 14(4)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29171687

RESUMO

To date, the possible depletion of lithium resources has become relevant, giving rise to the interest in Na-ion batteries (NIBs) as promising alternatives to Li-ion batteries. While extensive investigations have examined various transition metal oxides and chalcogenides as anode materials for NIBs, few of these have been able to utilize their high specific capacity in sodium-based systems because of their irreversibility in a charge/discharge process. Here, the mixed Sn-S nanocomposites uniformly distributed on reduced graphene oxide are prepared via a facile hydrothermal synthesis and a unique carbothermal reduction process, producing ultrafine nanoparticle with the size of 2 nm. These nanocomposites are experimentally confirmed to overcome the intrinsic drawbacks of tin sulfides such as large volume change and sluggish diffusion kinetics, demonstrating an outstanding electrochemical performance: an excellent specific capacity of 1230 mAh g-1 , and an impressive rate capability (445 mAh g-1 at 5000 mA g-1 ). The electrochemical behavior of a sequential conversion-alloying reaction for the anode materials is investigated, revealing both the structural transition and the chemical state in the discharge/charge process. Comprehension of the reaction mechanism for the mixed Sn-S/rGO hybrid nanocomposites makes it a promising electrode material and provides a new approach for the Na-ion battery anodes.

12.
J Nanosci Nanotechnol ; 18(9): 6565-6569, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29677835

RESUMO

The detection and monitoring of colorless and odorless chemical warfare agents (CWAs) has become important due to the increasing threat of terrorist activities. To enhance the sensitivity and selectivity of CWAs a number of sensing materials have been developed, including the widely used polyvinylidene fluoride (PVDF). However, PVDF is limited by its low sensitivity and selectivity for many CWAs. In this study, polyhedral oligomeric silsesquioxane (POSS) was used as a sensing material for dimethyl methylphosphonate (DMMP) a simulant of sarin nerve gas. Sensitivity, selectivity, and reusability were investigated with an AT-cut 5 MHz quartz crystal microbalance. At room temperature, POSS exhibited a strong response for DMMP vapor at different concentrations from 20 ppm to 120 ppm leading to fast chemical adsorption and desorption. To investigate selectivity the volatile organic compounds (VOCs) ethanol, water, toluene, ACN, methanol, and n-hexane were tested at a fixed flow rate. Targeted VOCs showed lower responses than DMMP as measured with a quartz crystal microbalance (QCM) sensor, demonstrating the high selectivity of the method. POSS can be considered a potentially useful material for sensing nerve simulants.

13.
BMC Surg ; 18(1): 34, 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-29855291

RESUMO

BACKGROUND: Following injection sclerotherapy using ALTA (aluminum potassium sulfate and tannic acid) (ALTAS) and transanal rectocele repair (TAR), changes in anorectal physiology were analyzed to compare the significance of the two treatments. METHODS: ALTAS was administered to 23 patients and 18 patients were treated using TAR. Efficacy measures included changes in defecography, anorectal manometry and constipation scoring system value. RESULTS: This was a retrospective cohort analysis conducted on prospectively collected data. Comparing anorectal physiology pre- and post- ALTAS, a statistically significant difference in push was observed with pre-ALTAS treatment (pre-A) at 104.33 ± 4.91° compared with post-ALTAS treatment (post-A) at 113.95 ± 4.74° (p < 0.001). With a pre-A value of 1.55 ± 0.18 cm and a post-A value of 2.46 ± 0.34 cm, perineal descent also showed an increase as well (p < 0.001). The rectocele size decreased post-A from a pre-A value of 7.74 ± 0.86 cm compared with a post-A value of 2.91 ± 0.52 cm (p < 0.001). The rectal sensation improved post-A compared with pre-A. Comparing anorectal physiology results of ALTAS and TAR treatments, no differences in defecography and rectal sensation were detected pre- and post-treatment. However, in terms of anorectal manometry, the mean resting pressure and maximal squeezing pressure showed statistical difference with two treatments. CONCLUSIONS: ALTAS treatment is a feasible option resulting in rapid and effortless long-term outcome, with low rates of complications. Therefore, this treatment may be an effective alternative for patients with symptomatic rectocele.


Assuntos
Compostos de Alúmen/administração & dosagem , Retocele/terapia , Escleroterapia/métodos , Taninos/administração & dosagem , Adulto , Canal Anal/fisiologia , Constipação Intestinal/etiologia , Defecação , Defecografia , Feminino , Humanos , Injeções , Pessoa de Meia-Idade , Períneo , Reto/fisiologia , Estudos Retrospectivos , Resultado do Tratamento
14.
Nanotechnology ; 27(17): 175102, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-26987360

RESUMO

A biocompatible polymer-gold nanorod (P-AuNR) conjugate was developed as a thermo-chemotherapeutic nano-sized drug carrier for cancer therapy using near-infrared (NIR) light as an external trigger. The amphiphilic polymer, poly(ethylene glycol)-block-poly(caprolactone) (PEG-b-PCL) bearing a disulfide bond, was prepared using a facile synthetic route via copper(I)-free click chemistry and covalently linked to AuNR. The chemical structures and successful conjugation of PEG-b-PCL were analyzed using (1)H NMR and FT-IR. Doxorubicin (DOX), a hydrophobic anticancer drug, was effectively loaded into the hydrophobic PCL domain of P-AuNR through a simple dialysis method. P-AuNR showed longitudinal plasmon resonance absorption at the NIR region, thus generating heat under irradiation at 808 nm. Interestingly, exposure of P-AuNRs to NIR induced a structural change in the PCL block from a crystalline to an amorphous state, leading to the temporally controlled release of DOX. No significant release of DOX was observed from P-AuNRs under physiological conditions (pH 7.4), whereas the release rate of DOX was remarkably enhanced in response to NIR irradiation. In vitro cellular experiments to assess cytotoxicity and intracellular drug release behavior of DOX-P-AuNRs demonstrated that the release of DOX could be selectively regulated by NIR irradiation. Overall, DOX-P-AuNRs might have the potential to overcome the indiscriminate toxicity of free DOX.


Assuntos
Portadores de Fármacos/química , Ouro/química , Raios Infravermelhos , Lactonas/química , Nanotubos/química , Polietilenoglicóis/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Humanos , Espectroscopia de Ressonância Magnética , Neoplasias/tratamento farmacológico , Fototerapia , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
15.
J Nanosci Nanotechnol ; 15(10): 8048-54, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26726461

RESUMO

The mechanical, thermal, optical, electrical and morphological properties of cellulose, an excellent natural biomaterial, can be improved by organic-inorganic hybrid composite methods. Based on the pristine properties of cellulose, the preparation of cellulose-metal oxide hybrid nanocomposites using a dispersion process of nanoparticles into the cellulose host matrix by traditional methods, has limitations. Recently, the functionalized cellulose-polymer-based materials were considered to be an important class of high-performance materials, providing the synthesis of various functional hybrid nanocomposites using a sol-gel method. Transparent cellulose-POSS-amine-silica/titania hybrids were prepared by an in-situ sol-gel process in the presence of γ-aminopropyltrimethoxylsilane (γ-APTES). The methodology involves the formation of covalent bonding between the cellulose-POSS amine and SiO2/TiO2 hybrid nanocomposite material. An analysis of the synthesized hybrid material by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, differential thermal calorimetry, scanning electron microscopy, and transmission electron microscopy indicated that the silica/titania nanoparticles were bonded covalently and dispersed uniformly into the cellulose-POSS amine matrix. In addition, biological properties of the cellulose-POSS-silica/titania hybrid material were examined using an antimicrobial test against pathogenic bacteria, such as Bacillus cereus (F481072) and E. coli (ATCC35150) for the bacterial effect.


Assuntos
Antibacterianos , Celulose , Nanocompostos/química , Compostos de Organossilício , Dióxido de Silício , Titânio , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus cereus/crescimento & desenvolvimento , Celulose/química , Celulose/farmacologia , Escherichia coli/crescimento & desenvolvimento , Compostos de Organossilício/química , Compostos de Organossilício/farmacologia , Dióxido de Silício/química , Dióxido de Silício/farmacologia , Titânio/química , Titânio/farmacologia
16.
Liver Int ; 34(4): 604-11, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24382309

RESUMO

BACKGROUND & AIMS: The course of NAFLD (nonalcoholic fatty liver disease) and associated factors in nonobese subjects are not well established. We investigated contributing factors for the development and regression of NAFLD in nonobese Koreans, and whether they would differ from those of obese subjects. METHODS: Two thousand three hundred and seven adults aged over 18 years participated in this longitudinal observational study. The mean duration of follow-up was 28.7 (±13.2) months. The participants were divided into two groups according to the baseline BMI (nonobese group: BMI <25 kg/m(2), obese group: BMI ≥25 kg/m(2)). The presence or absence of NAFLD was assessed by abdominal ultrasonography. RESULTS: Body weight change was independently associated with both the development and regression of NAFLD in nonobese subjects as well as obese subjects. Among the subjects who developed NAFLD, the amount of weight change was higher in nonobese subjects compared to obese subjects (1.6 ± 3.9% vs 0.6 ± 4.2%, P = 0.022); and among those who showed regression of NAFLD, the amount of weight change was lower in nonobese subjects (-1.9 ± 4.0% vs -5.0 ± 4.6%, P < 0.001). Among all the components of metabolic syndrome, only high triglyceride levels (>150 mg/dl) at the baseline were significantly associated with both the development and regression of NAFLD in nonobese subjects (ORs, 1.54 (1.10-2.14), and 0.60 (0.38-0.96) respectively). CONCLUSION: Body weight change and baseline triglyceride levels were strong indicators for the development and regression of NAFLD in a nonobese population.


Assuntos
Adiposidade/fisiologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Aumento de Peso/fisiologia , Adulto , Índice de Massa Corporal , Fígado Gorduroso/diagnóstico por imagem , Humanos , Estudos Longitudinais , Hepatopatia Gordurosa não Alcoólica , Análise de Regressão , República da Coreia , Triglicerídeos/sangue , Ultrassonografia
17.
Nanotechnology ; 25(9): 092001, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24521757

RESUMO

Most sensors are based on ceramic or semiconducting substrates, which have no flexibility or biocompatibility. Polymer-based sensors have been the subject of much attention due to their ability to collect molecules on their sensing surface with flexibility. Beyond polymer-based sensors, the recent discovery of cellulose as a smart material paved the way to the use of cellulose paper as a potential candidate for mechanical as well as electronic applications such as actuators and sensors. Several different paper-based sensors have been investigated and suggested. In this paper, we review the potential of cellulose materials for paper-based application devices, and suggest their feasibility for chemical and biosensor applications.

18.
J Nanosci Nanotechnol ; 14(10): 7558-61, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25942825

RESUMO

Cellulose is the most abundant bio-renewable materials with a long and well established technological base products and important applications such as fiber and paper materials. The one dimensional nano-materials such as nanotubes, nanowires and nano-rods have been widely studied for their potential applications in the field of nano-devices and nano-sensors due to their excellent electronic, optical properties. In this present work, the homogeneous cellulose-L-tyrosine-silica hybrid materials is prepared by in-situ sol-gel process using TEOS and γ-aminopropyltriethoxysilane (γ-APTES) as coupling agent. The silica nano-materials could be attached to the surface of amino functionalized cellulose-L-tyrosine matrices. The covalent bonding behavior of silica were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and transmission electron Microscopy (TEM).


Assuntos
Celulose/química , Nanocompostos/química , Nanotecnologia/métodos , Dióxido de Silício/química , Tirosina/química , Técnicas de Química Sintética , Hidrólise , Propilaminas , Silanos/química
19.
J Nanosci Nanotechnol ; 14(10): 7458-62, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25942809

RESUMO

In this paper, a cellulose-based Electro-Active Paper (EAPap) energy scavenging transducer is presented. Cellulose is proven as a smart material, and exhibits piezoelectric effect. Specimens were prepared by coating gold electrodes on both sides of cellulose film. The fabricated specimens were tested by a base excited aluminum cantilever beam at resonant frequency. Different tests were performed with single and multiple parallel connected electrodes coated on the cellulose film. A maximum of 131 mV output voltage was measured, when three electrodes were connected in parallel. It was observed that voltage output increases significantly with the area of electrodes. From these results, it can be concluded that the piezoelectricity of cellulose-based EAPap can be used in energy transduction application.


Assuntos
Celulose , Transdutores , Eletricidade , Papel , Vibração
20.
J Nanosci Nanotechnol ; 14(10): 7495-501, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25942815

RESUMO

Cellulose and one dimensional nano-material composite has been investigated for various industrial applications due to their optical, mechanical and electrical properties. In present investigation, cellulose/silica and silica-gold hybrid biomaterials were prepared by sol-gel covalent cross-linking process. The tetraethoxysiliane (TEOS) and gold precursors and γ-aminopropyltriethoxysilane (γ-APTES) as coupling agent were used for sol-gel cross-linking process. The chemical and morphological properties of cellulose/silica and cellulose/silica-gold nano-materials via covalent cross-linking hybrids were confirmed by FTIR, XRD, SEM, and TEM analysis. In the sol-gel process, the inorganic particles were dispersed in the cellulose host matrix at the nanometer scale, bonding to the cellulose through the covalent bonds.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Eletrônica , Ouro/química , Nanoestruturas/química , Dióxido de Silício/química , Fenômenos Mecânicos , Fenômenos Ópticos , Propilaminas , Silanos/química , Temperatura
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