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1.
Magn Reson Chem ; 60(9): 877-883, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35665956

RESUMO

In this paper, we evaluated the particle dispersion degree of alumina slurry containing a dispersant by solvent nuclear magnetic resonance (NMR) relaxation and compared it with conventional dispersion evaluation methods such as viscosity, particle size, and sedimentation height measurements. The dispersion of slurry was evaluated via numerical analysis of the transverse relaxation time (T2 ). The effect of the changes in different parameters of the experiment in terms of milling time, solid loading, and dispersant amount was investigated by NMR relaxation as well as conventional methods. The results of NMR relaxation measurements revealed that T2 correlates well with other dispersion evaluation methods; thus, it is an efficient technique to evaluate the dispersion of alumina slurry, specifically, when studying the effect of the change in milling time and dispersion amount.

2.
Muscle Nerve ; 51(3): 333-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24958627

RESUMO

INTRODUCTION: Split hand is considered to be a specific feature of amyotrophic lateral sclerosis (ALS). METHODS: We evaluated the pattern difference of intrinsic hand muscles of upper limb-onset ALS (UL-ALS), upper limb-onset progressive muscular atrophy (UL-PMA), brachial amyotrophic diplegia (BAD), and Hirayama disease (HD) by measuring objective electrophysiological markers. RESULTS: The abductor digiti minimi (ADM)/abductor pollicis brevis (APB) compound muscle action potential (CMAP) amplitude ratio was significantly higher in UL-ALS than other variants, but a considerable proportion of UL-ALS cases had an amplitude ratio in the range of other variants. Absent APB CMAP and abnormally high ADM/APB CMAP amplitude ratio (≥4) occurred only with UL-ALS. Conversely, an absent ADM CMAP was identified only in UL-PMA and BAD. CONCLUSIONS: The absolute ADM/APB CMAP amplitude ratio was not specific for ALS; however, several findings from simple electrophysiological measurements may help predict prognosis in patients with motor neuron diseases and may be early diagnostic markers for ALS.


Assuntos
Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/epidemiologia , Mãos/patologia , Atrofia Muscular/diagnóstico , Atrofia Muscular/epidemiologia , Potenciais de Ação/fisiologia , Adolescente , Adulto , Idoso , Esclerose Lateral Amiotrófica/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atrofia Muscular/fisiopatologia , Estudos Retrospectivos , Adulto Jovem
3.
Ann Otol Rhinol Laryngol ; 124(1): 62-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25048959

RESUMO

OBJECTIVE: Ethanol ablation has been known as an effective, easy, and safe treatment of cystic thyroid lesions. The objective of the present study was to evaluate efficacy of ethanol ablation as a minimally invasive management of thyroglossal duct cyst (TGDC). METHODS: Between January 2012 and July 2013, 9 TGDC patients were diagnosed and treated with ethanol ablation. We evaluated the treatment outcomes with the change of volume reduction and the improvement of symptomatic and cosmetic complaints and complications. RESULTS: Initial mean tumor volume was 8.9 mL (range, 0.2-36.9 mL) in ultrasonography. The mean number of the treatment sessions was 1.7 (range, 1-3 sessions). At last follow-up, the mean volume of the treated thyroglossal duct cyst decreased significantly from 8.9 mL to 1.9 mL (P = .019; volume reduction rate = 76.6%). Treatment success rate was 77.8% (7/9). Mean symptoms and cosmetic-grading scores improved from 5.2 to 3.1 and from 5.3 to 3.1 (P = .062). No significant complications were observed during follow-up. CONCLUSION: Ethanol ablation is a feasible and convenient procedure without surgical scars and hospitalization for TGDC patients. Favorable outcomes can be achieved without significant complications.


Assuntos
Etanol/administração & dosagem , Escleroterapia/métodos , Solventes/administração & dosagem , Cisto Tireoglosso/terapia , Adolescente , Adulto , Estudos de Coortes , Feminino , Humanos , Injeções Intralesionais , Masculino , Pessoa de Meia-Idade , Cisto Tireoglosso/patologia , Resultado do Tratamento , Adulto Jovem
4.
Langmuir ; 30(35): 10668-77, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25121826

RESUMO

A KB cancer cell-selective, liquid crystal microdroplets emulsion is prepared using folic acid-conjugated block copolymers (PS-b-PAA-FA) and sodium dodecyl sulfate (SDS) as a mediator to induce configurational transitions in 4-cyano-4'-pentylbiphenyl (5CB) liquid crystal microdroplets emulsion. The prepared liquid crystal microdroplets emulsion has shown a configurational transition from radial to bipolar on interacting with KB cancer cells, but no transition from radial to bipolar configuration is observed when liquid crystal microdroplets emulsion was allowed to interact with other normal cells such as fibroblast and osteoblast. The KB cancer cell selectivity of liquid crystal microdroplets emulsion has been considered due to the presence of KB cancer cell folate receptor-specific ligand (FA) at the surface of liquid crystal microdroplets, which allowed liquid crystal microdroplets to interact specifically with KB cancer cells. The ligand-receptor interactions have been considered responsible for triggering the configurational transitions from radial to bipolar in liquid crystal microdroplets emulsion. Thus, folate ligand anchored liquid crystal microdroplets emulsion has shown a potential to be used for in vitro detection of KB cancer cells in the early stage of tumor development.


Assuntos
Ácido Fólico/química , Cristais Líquidos/química , Linhagem Celular , Emulsões/química , Humanos
5.
Korean J Fam Med ; 44(4): 205-214, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37248072

RESUMO

BACKGROUND: Similar to smoking, exposure to secondhand smoke is a risk factor for developing hypertension and cardiovascular diseases; however, there is no standardized method for measuring smoke exposure. Measuring urine cotinine levels is one possible means for determining the degree of exposure to secondhand smoke. This study investigated the association between urinary cotinine levels and blood pressure in Korean adults exposed to secondhand smoke. METHODS: Data from the Korea National Health and Nutrition Examination Survey conducted between 2016 and 2018 were used. A total of 9,273 participants aged ≥19 years self-reported as current non-smokers, which was cotinine- verified. A complex sample general linear model regression analysis was performed to analyze the association between urine cotinine and blood pressure. A P-value of <0.05 was considered statistically significant. RESULTS: Corrected urine cotinine levels were positively associated with systolic and diastolic blood pressure in female participants (P<0.001 and P=0.040, respectively). Furthermore, a 10-fold increase in the corrected urine cotinine level of those in contact with secondhand smoke was independently associated with 2.085 mm Hg and 0.575 mm Hg increases in systolic and diastolic blood pressure, respectively. However, there was no association between systolic and diastolic blood pressure in male participants (P=0.226 and P=0.256, respectively). CONCLUSION: Urinary cotinine levels were positively associated with increased blood pressure in females exposed to secondhand smoke. Therefore, urinary cotinine may be used as an indicator to quantify and monitor the effects of blood pressure elevation in females exposed to secondhand smoke.

6.
J Nanosci Nanotechnol ; 12(2): 1415-20, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22629969

RESUMO

ZnO nanowires were grown on indium tin oxide (ITO) coated glass substrates at a low temperature of 90 degrees C using an aqueous solution method. The ZnO seeds were coated on the ITO thin films by using a spin coater. ZnO nanowires were formed in an aqueous solution containing zinc nitrate hexahydrate (Zn(NO3)2 x 6H2O) and hexamethylenetetramine (C6H12N4). The pH value and concentration of the solution play an important role in the growth and morphologies of ZnO nanowires. The size of ZnO naonowires increased as the concentration of the solution increased. It was formed with a top surface of hexagonal and tapered shape at low and high pH values respectively. Additionally, the single crystalline structure and optical property of the ZnO nanowires were investigated using high-resolution transmission electron microscopy and photoluminescence spectroscopy.

7.
Biomaterials ; 280: 121257, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34839122

RESUMO

Recent strategies in cancer immunotherapy based on interleukin-2 (IL-2) are generally focused on reducing regulatory T cell (Treg) development by modifying IL-2 receptor alpha (IL-2Rα) domain. However, the clinical utility of high-dose IL-2 treatment is mainly limited by severe systemic toxicity. We find that peritumorally injectable 'BALLkine-2', recombinant human IL-2 (rIL-2) loaded porous nanoparticle, dramatically reduces systemic side effects of rIL-2 by minimizing systemic IL-2 exposure. Notably, in cynomolgus monkeys, subcutaneous (SC)-injection of BALLkine-2 not only dramatically reduces systemic circulation of rIL-2 in the blood, but also increases half-life of IL-2 compared to IV- or SC-injection of free rIL-2. Peritumorally-injected BALLkine-2 enhances intratumoral lymphocyte infiltration without inducing Treg development and more effectively synergizes with PD-1 blockade than high-dose rIL-2 administration in B16F10 melanoma model. BALLkine-2 could be a highly potent therapeutic option due to higher anti-tumor efficacy with lower and fewer doses and reduced systemic toxicity compared to systemic rIL-2.


Assuntos
Melanoma , Nanopartículas , Humanos , Imunoterapia , Interleucina-2/uso terapêutico , Melanoma/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Linfócitos T Reguladores
8.
J Clin Med ; 10(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204466

RESUMO

There is no information about whether maternal neutrophil to lymphocyte ratios (NLRs) progressively increase with respect to the progression of acute histologic chorioamnionitis (acute-HCA) and increased maternal NLR is a risk factor for amnionitis, known as advanced acute-HCA, in pregnant women at risk for spontaneous preterm birth (PTB). The objective of the current study is to examine this issue. The study population included 132 singleton PTB (<34 weeks) due to either preterm labor or preterm-PROM with both placental pathology and maternal CBC results within 48 h before delivery. We examined maternal NLRs according to the progression of acute-HCA in extra-placental membranes (EPM) (i.e., group-0, inflammation-free EPM; group-1, inflammation restricted to decidua; group-2, inflammation restricted to the membranous trophoblast of chorion and the decidua; group-3, inflammation in the connective tissue of chorion but not amnion; group-4, amnionitis). Maternal NLRs significantly and progressively increased with the progression of acute-HCA (Spearman's rank correlation test, γ = 0.363, p = 0.000019). Moreover, the increased maternal NLR (≥7.75) (Odds-ratio 5.56, 95% confidence-interval 1.26-24.62, p < 0.05) was a significant independent risk factor for amnionitis even after the correction for potential confounders. In conclusion, maternal NLRs significantly and progressively increased according to the progression of acute-HCA and the increased maternal NLR (≥7.75) was an independent risk factor for amnionitis in spontaneous PTB. The evaluation of the performance of NLR should clearly require a prospective description of this parameter in a cohort of patients with either threatened PTL or preterm-PROM.

9.
J Clin Med ; 10(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34300208

RESUMO

No information exists about whether intra-amniotic inflammatory response increases with a chorio-deciduitis grade in the context of both inflammation-restricted to chorio-decidua and amnionitis of extra-placental membranes among spontaneous preterm births. The objective of current study is to examine this issue. A study population included 195 singleton pregnant women with chorio-deciduitis, and who spontaneously delivered at preterm (21.6~35.7 weeks) within 7 days of amniocentesis. We examined intra-amniotic inflammatory response according to the chorio-deciduitis grade in the context of inflammation restricted to chorio-decidua and amnionitis of extra-placental membranes. Intra-amniotic inflammatory response was measured by MMP-8 concentration (ng/mL) and WBC-count (cells/mm3) in amniotic-fluid (AF). Inflammation restricted to chorio-decidua and amnionitis were present in 47.7% (93/195) and 52.3% (102/195) of cases, respectively. Median AF MMP-8 concentration and WBC-count significantly increased with chorio-deciduitis grade in the context of inflammation restricted to chorio-decidua. However, there was no significant difference in median AF MMP-8 concentration and WBC-count between chorio-deciduitis grade-1 and grade-2 in the context of amnionitis. The inflammatory milieu of AF increases with chorio-deciduitis grade in inflammation-restricted to chorio-decidua, but not amnionitis, of extra-placental membranes. This finding suggests that a chorio-deciduitis grade may have little effect on the intensification of intra-amniotic inflammatory response in the context of amnionitis of extra-placental membranes.

10.
ACS Appl Mater Interfaces ; 12(30): 34274-34282, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32639143

RESUMO

Biaxial p-SnO/n-ZnO heterostructured nanowires (average length of 10 µm) were grown onto a glass substrate by thermal evaporation in vacuum. These nanowires had spherical ball tips, and the size of the SnO part increased gradually from the top to the bottom of the nanowire, but the corresponding size of ZnO varied slightly. The Sn-Zn alloy formed in the tips resulted in determined as the catalyst of the growth of the ZnO nanowires. The growth process of the p-SnO/n-ZnO biaxial nanowires is discussed based on vapor-liquid-solid (VLS) based on the subsequent growth process: the VLS catalytic growth of the ZnO nanowire and subsequent epitaxial SnO growth on the sidewall of the pregrown ZnO nanowire. An epitaxial relationship, (001)SnO//(110)ZnO and [110]SnO//[002]ZnO, was observed in the biaxial p-SnO/n-ZnO heterostructured nanowires. The gas-sensing properties of the as-synthesized p-SnO/n-ZnO nanowires were investigated. The results show that the device exhibit a good performance to the ppb-level NO2 at room temperature (25 °C) without light illumination. The detection limit of the p-SnO/n-ZnO sensor to NO2 is 50 ppb. Moreover, the NO2-sensing properties of the p-SnO/n-ZnO device were investigated under various relative humidity. Finally, the NO2-sensing mechanism of the p-SnO/n-ZnO nanowires was proposed and discussed.

11.
Korean J Radiol ; 20(4): 609-620, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30887743

RESUMO

Minimally invasive treatment of symptomatic thyroid nodules is now commonplace. Ethanol ablation (EA) of thyroid cystic nodules has been performed since the 1990s, but there is no global consensus or guideline. Although various limitations of EA have been described, recommendations for practical application are necessary. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology initiated the present consensus statement and here we provide recommendations for the role of EA in the management of symptomatic thyroid nodules. These recommendations are based on evidence to date from the literature and expert opinion.


Assuntos
Ablação por Cateter/métodos , Etanol/química , Nódulo da Glândula Tireoide/cirurgia , Guias como Assunto , Humanos , República da Coreia , Sociedades Médicas
12.
Korean J Radiol ; 18(1): 217-237, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28096731

RESUMO

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.


Assuntos
Biópsia com Agulha de Grande Calibre/métodos , Neoplasias da Glândula Tireoide/patologia , Biópsia com Agulha de Grande Calibre/efeitos adversos , Biópsia com Agulha de Grande Calibre/instrumentação , Hematoma/etiologia , Rouquidão/etiologia , Humanos , Biópsia Guiada por Imagem , Assistência ao Paciente , República da Coreia , Sociedades Médicas , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Ultrassonografia Doppler
13.
Medicine (Baltimore) ; 95(36): e4759, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27603375

RESUMO

BACKGROUND: Primary small cell carcinomas (SCCs) are uncommon in extrapulmonary sites and account for only 2.5% to 5.0% of all SCCs. SCCs in the pyriform sinus are rare and there is little information regarding this disease, especially on therapeutics. Herein, we present a case of successfully treated SCC in the right pyriform sinus that occurred in a patient with small cell lung carcinoma (SCLC) that completely resolved 4 years prior. METHODS: A 1.5 × 1.5-cm mass in the right pyriform sinus was detected on imaging studies in a 71-year-old male at a regular check-up visit after being in remission from SCLC. RESULTS: Based on histologic examination and immunohistochemistry, the tumor in the right pyriform sinus was diagnosed as an extrapulmonary SCC. Chemo-radiotherapy was applied to the SCC of the pyriform sinus with a regimen of etoposide and cisplatin. The patient exhibited complete response to treatment and has been disease free for 11 months. CONCLUSION: This interesting case shows that chemotherapy with concurrent radiation may be an effective therapeutic modality for localized extrapulmonary SCC similar to localized SCLC, which is treated with concurrent chemo-radiotherapy as the standard therapeutic option.


Assuntos
Carcinoma de Células Pequenas/terapia , Neoplasias Hipofaríngeas/terapia , Neoplasias Pulmonares , Segunda Neoplasia Primária/terapia , Seio Piriforme , Carcinoma de Pequenas Células do Pulmão , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia , Cisplatino/administração & dosagem , Etoposídeo/administração & dosagem , Humanos , Neoplasias Pulmonares/terapia , Masculino , Segunda Neoplasia Primária/diagnóstico por imagem , Carcinoma de Pequenas Células do Pulmão/terapia
14.
ACS Appl Mater Interfaces ; 8(19): 12205-10, 2016 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-27127906

RESUMO

A lithium ionic conductor, Li1.3Al0.3Ti1.7(PO4)3 (LATP), is introduced as a coating material on the surface of Mg-doped LiCoO2 to improve electrochemical performances for high-voltage (4.5 V) lithium ion batteries. Structure, morphology, elemental distribution, and electrical properties of the materials are thoroughly characterized by SEM, TEM, EELS, EDS, and C-AFM. The coating layer is electrically conductive with the aid of Mg ions which are used as a dopant for the active materials; therefore, this mixed electronic ionic conductor strongly enhances the electrochemical performances of initial capacity, cycling property, and rate capability. The LATP coating layer also demonstrates very promising applicability for 4.4 V prismatic full cells with graphite anode, which correspond to the 4.5 V half-cells with lithium anode. The 2900 mA h full cells show 85% of capacity retention after 500 cycles and more than 60% after 700 cycles.

15.
ACS Appl Mater Interfaces ; 8(36): 23862-7, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27557404

RESUMO

We report broadband pH-sensing organic field-effect transistors (OFETs) with the polymer-dispersed liquid crystal (PDLC) sensing layers. The PDLC layers are prepared by spin-coating using ethanol solutions containing 4-cyano-4'-pentyl-biphenyl (5CB) and a diblock copolymer (PAA-b-PCBOA) that consists of LC-philic block [poly(4-cyano-biphenyl-4-oxyundecyl acrylate) (PCBOA)] and acrylic acid block [poly(acrylic acid) (PAA)]. The spin-coated sensing layers feature of 5CB microdomains (<5 µm) encapsulated by the PAA-b-PCBOA polymer chains. The resulting LC-integrated-OFETs (PDLC-i-OFETs) can detect precisely and reproducibly a wide range of pH with only small amounts (10-40 µL) of analyte solutions in both static and dynamic perfusion modes. The positive drain current change is measured for acidic solutions (pH < 7), whereas basic solutions (pH > 7) result in the negative change of drain current. The drain current trend in the present PDLC-i-OFET devices is explained by the shrinking-expanding mechanism of the PAA chains in the diblock copolymer layers.

16.
Korean J Radiol ; 17(3): 370-95, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27134526

RESUMO

The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the mainstay for the detection and risk stratification of thyroid nodules as well as for providing guidance for their biopsy and nonsurgical treatment. The Korean Society of Thyroid Radiology (KSThR) published their first recommendations for the US-based diagnosis and management of thyroid nodules in 2011. These recommendations have been used as the standard guidelines for the past several years in Korea. Lately, the application of US has been further emphasized for the personalized management of patients with thyroid nodules. The Task Force on Thyroid Nodules of the KSThR has revised the recommendations for the ultrasound diagnosis and imaging-based management of thyroid nodules. The review and recommendations in this report have been based on a comprehensive analysis of the current literature and the consensus of experts.


Assuntos
Neoplasias da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/diagnóstico , Técnicas de Imagem por Elasticidade , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Humanos , Processamento de Imagem Assistida por Computador , Linfonodos/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Guias de Prática Clínica como Assunto , Sociedades Médicas , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Ultrassonografia
17.
Medicine (Baltimore) ; 94(52): e2370, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26717381

RESUMO

Desmoid tumors (DTs) are a group of rare and benign soft tissue tumors that result from monoclonal proliferation of well-differentiated fibroblasts. Since DTs tend to infiltrate and compress adjacent structures, the location of DTs is one of the most crucial factors for determining the severity of the disease. Furthermore, DTs can further complicate the clinical course of patients when the growth is remarkably rapid, especially for DTs occurring in anatomically critical compartments, including the thoracic cavity.The authors report a case of a 71-year-old man with a known mediastinal mass incidentally detected 4 months ago, presenting dyspnea with right-sided atelectasis and massive pleural effusion. Imaging studies revealed a 16.4 × 9.4-cm fibrous mass with high glucose metabolism in the anterior mediastinum. The mass infiltrated into the chest wall and also displaced the mediastinum contralaterally. Interestingly, the tumor had an extremely rapid doubling time of 31.3 days.En bloc resection of the tumor was performed as a curative as well as a diagnostic measure. Histopathologic examination showed spindle cells with low cellularity and high collagen deposition in the stroma. Immunohistochemical staining was positive for nuclear ß-catenin. Based on these pathologic findings, the mass was diagnosed as DT. After surgery, there has been no evidence of recurrence of disease in the patient.This patient presents a mediastinal DT with extremely rapid growth. Notably, the doubling time of DT in our case was the shortest among reported cases of DT. Our experience also highlights the benefits of early interventional strategy, especially for rapidly growing DTs in the thoracic cavity.


Assuntos
Fibromatose Agressiva/patologia , Neoplasias do Mediastino/patologia , Idoso , Fibromatose Agressiva/complicações , Fibromatose Agressiva/diagnóstico , Fibromatose Agressiva/cirurgia , Humanos , Masculino , Neoplasias do Mediastino/complicações , Neoplasias do Mediastino/diagnóstico , Neoplasias do Mediastino/cirurgia , Derrame Pleural/etiologia , Atelectasia Pulmonar/etiologia
18.
J Nanosci Nanotechnol ; 14(12): 9020-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25971002

RESUMO

The growth of ZnO nanorods on the c-plane of Al2O3 substrates by PLD was been investigated by controlling processing conditions such as growth temperature, distance between target and substrate, and background oxygen pressure. ZnO nanorods were observed from the growth temperature of 600 degrees C for the oxygen pressure of 30 mTorr and the target/substrate distance of 70 mm. The diameters of the ZnO nanorods at the temperature of 700 degrees C and the oxygen pressure of 30 mTorr were approximately 200, 70, and 40 nm for the distance of 45, 70, and 100 mm, respectively. ZnO films without nanorods were observed at the distance of 70 mm and the temperature of 700 degrees C when the oxygen pressure decreased to 1 mTorr. The kinetic energy of the ablated particles by the laser decreases during collisions with background oxygen molecules, resulting in conditions that favor the growth of ZnO nanorods.

19.
Colloids Surf B Biointerfaces ; 121: 400-8, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25009103

RESUMO

The interface between the nematic liquid crystal, 4-cyano-4'-pentylbiphenyl (5CB) and water within a transmission electron microscopy (TEM) grid cell coated with the pH-dependent weak cationic amphiphilic block copolymer poly((4-cyanobiphenyl-4'-oxyundecylacrylate)-b-((2-dimethyl amino) ethyl methacrylate)) (LCP-b-PDMAEMA) (which was successfully synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization) was subsequently evaluated for protein and deoxyribonucleic acid (DNA) detection. The LCP-b-PDMAEMA monolayer was fabricated using a Langmuir Blodgett trough, transferred to the 5CB-filled TEM grid, and placed on the octadecyltrichlorosilane-coated glass (TEMPDMAEMA) in such a way that the LCP chains were immersed in the 5CB while the PDMAEMA chains were pointed away from the 5CB surface and immersed in water. Several model proteins such as bovine serum albumin (BSA), hemoglobin (Hb), and chymotrypsinogen (ChTg) were tested at pH values ranging from 2 to 12 to determine the role of the charge state of the protein on protein detection by a weak polyelectrolyte such as PDMAEMA. PDMAEMA contains cationic and neutral states below and above the pKa value, respectively, and is thus able to absorb proteins below its pKa threshold through electrostatic interactions. BSA exhibited a homeotropic to planar (H-P) change in orientation within the TEMPDMAEMA grid cell at concentrations greater than 0.02wt% within the pH range between the isoelectric point (pI) of BSA and the pKa of PDMAEMA, where the charge states of BSA and PDMAEMA were negative and positive, respectively. However, this change in orientation did not occur with other proteins that exhibited a pI higher than the pKa of PDMAEMA due to the electrostatic repulsions resulting from their same cationic charges. This result indicates that the electrostatic interactions between proteins and PDMAEMA are a major contributing factor for protein detection by the H-P transformation within the TEMPDMAEMA grid cell. DNA, a pH-independent strong anionic polyelectrolyte, was also tested with the TEMPDMAEMA grid cell, and it exhibited an H-P transformation at the charged state of PDMAEMA below its pKa threshold at concentrations higher than 0.01wt%. Thus, we demonstrated that the TEMPDMAEMA grid cell effectively facilitated the detection of negatively charged biomaterials (i.e.; protein and DNA) through the H-P transformation using the polarized optical microscope. This simple and inexpensive experimental set-up for non-specific biomaterial detection lays the basic groundwork for developing effective biosensors using polyelectrolytes.


Assuntos
Técnicas Biossensoriais/métodos , Cristais Líquidos/química , Ácidos Polimetacrílicos/química , Água/química , Animais , Bovinos , DNA/análise , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Polimerização , Ácidos Polimetacrílicos/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Soroalbumina Bovina/análise , Soroalbumina Bovina/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Biomed Res Int ; 2014: 954307, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24511553

RESUMO

Herceptin, a typical monoclonal antibody, was immobilized on the surface of CdSe/ZnS core-shell quantum dots (QDs) to enhance their specific interactions with breast cancer cells (SK-BR3). The mean size of the core-shell quantum dots (28 nm), as determined by dynamic light scattering, increased to 86 nm after herceptin immobilization. The in vitro cell culture experiment showed that the keratin forming cancer cells (KB) proliferated well in the presence of herceptin-conjugated QDs (QD-Her, 5 nmol/mL), whereas most of the breast cancer cells (SK-BR3) had died. To clarify the mechanism of cell death, the interaction of SK-BR3 cells with QD-Her was examined by confocal laser scanning microscopy. As a result, the QD-Her bound specifically to the membrane of SK-BR3, which became almost saturated after 6 hours incubation. This suggests that the growth signal of breast cancer cells is inhibited completely by the specific binding of herceptin to the Her-2 receptor of SK-BR3 membrane, resulting in cell death.


Assuntos
Anticorpos Monoclonais Humanizados/farmacocinética , Neoplasias da Mama , Pontos Quânticos/metabolismo , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/farmacologia , Compostos de Cádmio/química , Compostos de Cádmio/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Tamanho da Partícula , Pontos Quânticos/química , Compostos de Selênio/química , Compostos de Selênio/farmacocinética , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfetos/química , Sulfetos/farmacocinética , Trastuzumab , Compostos de Zinco/química , Compostos de Zinco/farmacocinética
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