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1.
Microsc Res Tech ; 84(12): 3104-3115, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34309120

RESUMO

Polyamide-6 fiber was modified by grafting it with poly(methyl methacrylate) PMMA polymer. The grafting process is widely used in industry to introduce new properties and overcome some obstacles, for instance, in storing energy applications. Multiple-beam interference techniques are very precise techniques to characterize the different properties of polymeric fibers. Fringes of equal chromatic order FECO technique was used to study the effect of grafting process on the dispersion properties of polyamides fibers. A mechanical drawing device was attached to the FECO system to evaluate the mechanical deformation impact on the samples and on their dispersion properties. The dispersion properties were evaluated by measuring their refractive indices, Cauchy's constants, average excitation energy, dispersion energy, lattice energy, interband oscillator wavelength, static dielectric constant, and Abbe's dispersion number. The results show that grafting polyamide-6 with PMMA produced a new material with a different structure and different dispersion properties. Microinterferograms, graphs and tables were given for illustrations.

2.
Am J Rhinol Allergy ; 35(6): 802-808, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33745321

RESUMO

BACKGROUND: Acquiring proficiency for the repair of a cerebrospinal fluid (CSF) leak is challenging in great part due to its relative rarity, which offers a finite number of training opportunities. OBJECTIVE: The purpose of this study was to evaluates the use of a 3-dimensional (3D) printed, anatomically accurate model to simulate CSF leak closure. METHODS: Volunteer participants completed two simulation sessions. Questionnaires to assess their professional qualifications and a standardized 5-point Likert scale to estimate the level of confidence, were completed before and after each session. Participants were also queried on the overall educational utility of the simulation. RESULTS: Thirteen otolaryngologists and 11 neurosurgeons, met the inclusion criteria. A successful repair of the CSF leak was achieved by 20/24 (83.33%), and 24/24 (100%) during the first and second simulation sessions respectively (average time 04:04 ± 1.39 and 02:10 ± 01:11). Time-to-close-the-CSF-leak during the second session was significantly shorter than the first (p < 0.001). Confidence scores increased across the training sessions (3.3 ± 1.0, before the simulation, 3.7 ± 0.6 after the first simulation, and 4.2 ± 0.4 after the second simulation; p < 0.001). All participants reported an increase in confidence and believed that the model represented a valuable training tool. CONCLUSIONS: Despite significant differences with varying clinical scenarios, 3D printed models for cerebrospinal leak repair offer a feasible simulation for the training of residents and novice surgeons outside the constrictions of a clinical environment.


Assuntos
Vazamento de Líquido Cefalorraquidiano , Base do Crânio , Vazamento de Líquido Cefalorraquidiano/cirurgia , Simulação por Computador , Humanos , Impressão Tridimensional , Estudos Retrospectivos
3.
J Oleo Sci ; 69(10): 1219-1230, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32908101

RESUMO

Quality parameters of potato chips (flat and serrated) fried either in palm oil (PO) alone or containing natural (thyme (TPO) and rosemary (RPO) extracts) and synthetic BHT (BPO) antioxidants were evaluated during storage period. The free fatty acid and peroxide values of chips fried in PO (control) were found between 0.18 and 0.21% to 1.00 and 1.04 meqO2/kg during the first storage month, respectively. However, these values were 0.07-0.10% and 0.55-0.90 meqO2/kg for chips fried in TPO, respectively. The water contents increased when storage time increased from 1 to 7 month and their values changed between 0.49 and 1.95% (flat potato chips in BPO) and between 0.88 and 1.24% (serrated potato chips in TPO). The total trans-fat contents were 0.13% (serrated potato chips in BPO) and 0.35% (both flat and serrated potato chips in PO) at the start of storage. The total trans-fat content after 7 months were 0.13% (PO fried flat and serrated potato chips) and 0.17% (serrated potato chips fried in BPO, TPO and RPO). The acrylamide contents varied between 152 (serrated potato chips in PO) and 540 µg/kg (flat potato chips fried in RPO) at the beginning of storage. However, the acrylamide contents changed during 7th storage month and ranged from 182 (serrated potato chips in PO) to 518 µg/kg (flat potato chips in RPO). Among fatty acids, while palmitic acid are determined between 37.14 (flat chips in PO) and 41.60% (serrated chips in TPO), oleic acid varied between 30.0 (flat chips in RPO) and 33.00% (serrated chips in PO). Sensory evaluation showed that PO containing antioxidants showed better consumer preference for potato chips until the end of storage.


Assuntos
Antioxidantes/análise , Hidroxitolueno Butilado/análise , Culinária/métodos , Análise de Alimentos , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Armazenamento de Alimentos , Óleo de Palmeira , Extratos Vegetais , Rosmarinus/química , Solanum tuberosum/química , Paladar , Thymus (Planta)/química , Acrilamida/análise , Fenômenos Químicos , Ácidos Graxos não Esterificados/análise , Humanos , Peróxidos/análise , Ácidos Graxos trans/análise
4.
Microsc Res Tech ; 83(1): 56-65, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31625652

RESUMO

Mach-Zehnder interferometer technique is utilized to study the impact of grafting of the nylon-6 fibers with poly (methyl methacrylate) (PMMA) polymer on the optical, geometrical, and structural properties. He-Ne laser diffraction technique is applied to study the changes in the fiber thickness of two samples (nylon-6 blank and nylon-6 grafted with PMMA) at different positions along the fiber length. The geometrical parameters are investigated by determining the cross-sectional shape of the two samples. The results of the interferometric and the diffraction techniques show that there is no variation in the thickness of nylon-6 fiber but variations in the thickness of the grafted nylon-6 fiber are obvious. The optical and physical properties along the axis of these fibers are characterized by measuring their refractive indices, birefringence, polarizability per unit volume, dielectric constant, surface reflectivity and the refractive index profile. The results show that PMMA polymer changed the optical, geometrical, and structural properties of the nylon-6 blank fiber. Microinterferograms are given for illustrations.

5.
Ann R Coll Surg Engl ; 93(6): e119-21, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21929907

RESUMO

High-intensity focused ultrasonography is the only completely non-invasive thermal therapy. To date its applications have been limited but clinical indications are expanding with enhanced technological advances that have increased the accuracy of targeting and decreased the duration of treatment times. We report its first use for rectal cancer.


Assuntos
Adenocarcinoma/terapia , Recidiva Local de Neoplasia/terapia , Neoplasias do Colo Sigmoide/terapia , Ultrassom Focalizado Transretal de Alta Intensidade/métodos , Idoso , Estudos de Viabilidade , Humanos , Masculino
6.
J Obstet Gynaecol Res ; 34(4): 538-42, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18937706

RESUMO

AIM: To determine if the incidence of female genital malignancies changed with foreign immigration. METHODS: Retrospective analysis of histopathology records of women with primary genital tract cancers attending a referral gynecological hospital over two decades from 1985 to 2004. Incidence rates for the combined population of foreign migrants and Saudi nationals were compared to rates among Saudi nationals alone. Outcome measures were incidence rates and incidence rate ratios. RESULTS: The incidence of cervical cancer for the combined migrant and local Saudi population was 48.4%, while for Saudi nationals alone it was 33.5% (incident rate ratio [IRR]= 1.44, 95% CI 1.17-1.88, P < 0.001). For vulvar cancer, the incidence was 1.2% versus 0.5% (IRR = 2.4, 95% CI 2.03-2.79, P < 0.001). Endometrial cancer rate was lower in the combined population than in Saudi nationals alone (11.7% vs 18.0%, IRR = 0.65, 95% CI 0.27-1.02, P < 0.04). There were no differences in incidence for gestational trophoblastic neoplasia, uterine corpus sarcoma, ovarian, and vaginal cancer. Incidence rate ratios differed between decades for cervical cancer (1.1/1.9, 0.58, 95% CI 0.21-0.89, P < 0.001), vulvar cancer (4.2/1.8, 2.33, 95% CI 1.68-3.07, P < 0.001), gestational trophoblastic neoplasia (1.4/1.0, 1.4, 95% CI 1.09-2.13, P < 0.04), and uterine sarcoma (0.3/1.0, 0.03, 95% CI 0.012-0.041, P < 0.02). CONCLUSION: The incidence of cervical and vulvar cancer increased among women presenting with gynecological malignancies. For cervical and vulvar cancer, uterine corpus sarcoma, and gestational trophoblastic neoplasia, incidence varied over time.


Assuntos
Emigrantes e Imigrantes , Neoplasias dos Genitais Femininos/epidemiologia , Feminino , Humanos , Incidência , Arábia Saudita/epidemiologia
7.
Transplantation ; 75(12): 2068-76, 2003 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-12829914

RESUMO

BACKGROUND: The response of human CD4+ T cells against porcine cells is of comparable magnitude to that induced by human leukocyte antigen-mismatched allogeneic cells. This reflects productive interactions between key costimulatory molecules across the species barrier. Inhibition of these molecular interactions will be crucial in overcoming CD4+ T-cell-mediated rejection of xenografts. We have performed a detailed investigation to determine the expression profiles and relative contributions of the three key costimulatory molecules in the porcine-human xenogeneic response. Whereas only porcine CD86 is constitutively expressed on resting endothelial cells, both CD40 and CD80 are rapidly expressed after activation. All three costimulatory molecules are expressed by professional antigen-presenting cells. METHODS: We have isolated full-length cDNA clones for human and porcine CD80, CD86, and CD40. Human fibroblast cell lines (M1) coexpressing DR1 were transfected with these cDNAs and used in mixed lymphocyte reactions and flow cytometric studies in vitro. RESULTS: These data provide the first characterization of the expression profile and functional role of porcine CD80. Functional assays demonstrate that pCD40, pCD80, and pCD86 are independently capable of costimulating human CD4+ T cells, albeit with differing kinetics. Proliferative responses were of comparable magnitude to those obtained when costimulation was provided by human CD40, CD80, and CD86. CONCLUSIONS: These data have implications for therapy targeting the direct pathway of xenorecognition; costimulatory molecule blockade must be directed against both the B7/CD28 and CD40/CD40L pathways.


Assuntos
Antígenos CD/genética , Antígeno B7-1/genética , Antígenos CD40/genética , Ativação Linfocitária/imunologia , Glicoproteínas de Membrana/genética , Linfócitos T/imunologia , Animais , Antígeno B7-2 , Sequência de Bases , Primers do DNA , DNA Complementar , Fibroblastos/imunologia , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Especificidade da Espécie , Suínos , Fatores de Tempo , Transplante Heterólogo/imunologia
8.
Biol Res ; 35(2): 247-65, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12415743

RESUMO

The ADP-ribosylation factor family of small GTP-binding proteins are implicated in the regulation of vesicular transport and control of cytoskeletal and cell adhesion events. The phosphoinositide 3-kinase, phosphoinositide 4-P 5-kinase and phospholipase D signaling pathways are major regulators of ARF signaling cascades. Two families of ARF regulatory molecules, the cytohesin ARF-Guanine nucleotide Exchange Factors and the centaurin GTPase-Activating Proteins provide key targets for the action of these lipids signals. A critical feature of the regulation of ARF signaling is coordinated recruitment of exchange factors, ARFs and GAPs to appropriate subcellular locations. These complexes drive repetitive cycles of ARF activation and membrane association that underlie the processes of cell movement as well as endosomal uptake and intracellular redistribution of signaling molecules. Cytohesins and centaurins bind specifically to a variety of other signaling proteins and these interactions may provide routes for regulated recruitment to the sites of ARF activation. Through their ability to control endosomal trafficking/recycling of these supramolecular signaling complexes ARF and phospholipid signaling pathways may have consequences that reach as far as the regulation of gene transcription and control of cell fate.


Assuntos
Fatores de Ribosilação do ADP/fisiologia , Proteínas Ativadoras de GTPase/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Fosfatidilinositóis/fisiologia , Transdução de Sinais , Animais , Adesão Celular , Citoesqueleto , Proteínas Ativadoras de GTPase/classificação , Fatores de Troca do Nucleotídeo Guanina/classificação , Humanos , Integrinas/metabolismo , Substâncias Macromoleculares , Transporte Proteico/fisiologia
9.
Biol. Res ; 35(2): 247-265, 2002. ilus, tab
Artigo em Inglês | LILACS | ID: lil-323348

RESUMO

The ADP-ribosylation factor family of small GTP-binding proteins are implicated in the regulation of vesicular transport and control of cytoskeletal and cell adhesion events. The phosphoinositide 3-kinase, phosphoinositide 4-P 5-kinase and phospholipase D signaling pathways are major regulators of ARF signaling cascades. Two families of ARF regulatory molecules, the cytohesin ARF-Guanine nucleotide Exchange Factors and the centaurin GTPase-Activating Proteins provide key targets for the action of these lipids signals. A critical feature of the regulation of ARF signaling is coordinated recruitment of exchange factors, ARFs and GAPs to appropriate subcellular locations. These complexes drive repetitive cycles of ARF activation and membrane association that underlie the processes of cell movement as well as endosomal uptake and intracellular redistribution of signaling molecules. Cytohesins and centaurins bind specifically to a variety of other signaling proteins and these interactions may provide routes for regulated recruitment to the sites of ARF activation. Through their ability to control endosomal trafficking/recycling of these supramolecular signaling complexes ARF and phospholipid signaling pathways may have consequences that reach as far as the regulation of gene transcription and control of cell fate


Assuntos
Humanos , Animais , Fatores de Ribosilação do ADP , Proteínas Ativadoras de GTPase , Fatores de Troca do Nucleotídeo Guanina , Fosfatidilinositóis , Transdução de Sinais , Fatores de Ribosilação do ADP , Adesão Celular , Citoesqueleto , Proteínas Ativadoras de GTPase , Fatores de Troca do Nucleotídeo Guanina , Integrinas , Substâncias Macromoleculares , Fosfatidilinositóis , Transporte Proteico
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