Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Opt Express ; 27(18): 24885-24899, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31510370

RESUMO

Mid-spatial frequency (MSF) errors challenge freeform manufacture, not in the least due to tool-misfit. This can compromise the performance of functional surfaces and is difficult to remove by post-processing. Our previously reported work on an effective process-chain for aluminum polishing demonstrated the ability to remove MSFs by hard-tool grolishing. In this paper, we describe MSF removal on an aluminum mirror, deformed to a saddle-like freeform shape, using power spectral density (PSD) as a diagnostic. CNC Precessions bonnet polishing was optimized to minimize output MSFs, then a non-Newtonian (n-N) tool was used to attenuate the residual MSFs that were present. Our approach was distinct from the approach pioneered by University of Arizona, in that we adopted small-tool polishing on the saddle-like part, with removal rate restored by rotating the n-N tool. In order to define the optimum window of rotation speeds, the dynamic behavior of the n-N material was explored by modelling and experiments. The tool was deployed on an industrial robot, and we describe a novel 'hyper-crossing' tool-path with wide sweeping paths, which is the logical opposite of the unicursal zero-crossing paths we have previously reported. This new path has proved ideally suited to robots, given their high velocity/acceleration capabilities. Detailed results are presented from the PSD viewpoint.

2.
J Neurol Surg B Skull Base ; 80(2): 209-213, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30931230

RESUMO

Despite numerous advancements in the treatment of skull base tumors, the management of jugular paragangliomas remains controversial and nuanced. Contemporary treatment objectives focus not only on achieving durable tumor control but also on maximizing post-treatment quality of life. While this philosophy places appropriate attention on limiting cranial neuropathies, less discussed morbidities such as hearing loss can have a profound impact on quality of life outcomes. The objective of this retrospective review is to provide a comprehensive review of hearing outcomes following the treatment of tympanojugular paragangliomas. A particular focus is placed on the variable audiologic outcomes as it relates to disease pathology, extent of disease, as well as chosen treatment modality. This review underscores the importance of considering treatment-related effects on hearing.

3.
Otolaryngol Head Neck Surg ; 158(5): 923-929, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29529928

RESUMO

Objective Despite the rising incidence of methicillin-resistant Staphylococcus aureus (MRSA) otologic infections, choice of treatment remains controversial. Only fluoroquinolone-containing ototopical preparations are approved by the US Food and Drug Administration for middle ear application. Furthermore, American Academy of Otolaryngology-Head and Neck Surgery Foundation guidelines advocate ototopical monotherapy for both tympanostomy tube otorrhea and acute otitis externa. Unfortunately, MRSA may be ciprofloxacin resistant. This causes confusion regarding antibiotic selection, because susceptibility profiles reflect a minimum inhibitory concentration (MIC), referenced against systemic, not ototopical, drug delivery dosing. The goal of this study is to determine the ciprofloxacin MIC for ciprofloxacin-resistant MRSA isolates from otologic infections and compare that value to the expected drug concentration achieved by fluoroquinolone ear drops and determine MRSA genotype for each isolate. Study Design In vitro assay with retrospective medical record review. Setting Tertiary care university hospital. Subjects and Methods Thirty otologically sourced ciprofloxacin-resistant MRSA isolates collected from adult and pediatric patients. MICs were calculated by broth dilution method. Isolates underwent multilocus sequence typing and polymerase chain reaction for arcA and Panton-Valentine leukocidin to establish the genotype. Results MICs ranged from 16 to 1025 µg/mL. There was a relationship between MIC and genotype; of the 7 isolates with an MIC value greater than 512 µg/mL, 6 were sequence type (ST)8. Conclusion These findings support the practice of ototopical monotherapy for patients with uncomplicated ciprofloxacin-resistant MRSA otitis externa. However, they raise concern that ototopical therapy may not be adequate to treat highly resistant strains of MRSA infecting the middle ear space.


Assuntos
Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Otite/microbiologia , Infecções Estafilocócicas/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Adulto Jovem
4.
J Appl Psychol ; 102(2): 163-179, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27893256

RESUMO

Customer service employees tend to react negatively to customer incivility by demonstrating incivility in return, thereby likely reducing customer service quality. Research, however, has yet to uncover precisely what customers do that results in employee incivility. Through transcript and computerized text analysis in a multilevel, multisource, mixed-method field study of customer service events (N = 434 events), we found that employee incivility can occur as a function of customer (a) aggressive words, (b) second-person pronoun use (e.g., you, your), (c) interruptions, and (d) positive emotion words. First, the positive association between customer aggressive words and employee incivility was more pronounced when the verbal aggression included second-person pronouns, which we label targeted aggression. Second, we observed a 2-way interaction between targeted aggression and customer interruptions such that employees demonstrated more incivility when targeted customer verbal aggression was accompanied by more (vs. fewer) interruptions. Third, this 2-way interaction predicting employee incivility was attenuated when customers used positive emotion words. Our results support a resource-based explanation, suggesting that customer verbal aggression consumes employee resources potentially leading to self-regulation failure, whereas positive emotion words from customers can help replenish employee resources that support self-regulation. The present study highlights the advantages of examining what occurs within customer-employee interactions to gain insight into employee reactions to customer incivility. (PsycINFO Database Record


Assuntos
Agressão/psicologia , Comportamento do Consumidor , Emprego/psicologia , Relações Interpessoais , Comportamento Verbal , Adulto , Comércio , Feminino , Humanos , Masculino
5.
JAMA ; 316(11): 1215, 2016 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-27654616
6.
JAMA ; 315(20): 2221-2, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27218631
7.
Laryngoscope ; 126(6): 1426-32, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26371439

RESUMO

OBJECTIVES/HYPOTHESIS: To describe the elements critical to successful middle temporal artery periosteal rotational flap harvest and utilization based on the anatomic features of the middle temporal artery. STUDY DESIGN: Description of anatomy based on cadaver dissection. METHODS: Seventy temporal fossa dissections were performed on 35 adult human cadavers. RESULTS: Sixty-nine of 70 dissections had an identifiable middle temporal artery muscular branch pedicle in the periosteum deep to the temporalis muscle. Pedicle length was at least 7 cm in 32 of 38 (84%) male cadavers and in 20 of 31 (65%) female cadavers (P = 0.054), whereas the average length required to reach the digastric ridge from the pedicle base to the digastric ridge in a mastoidectomy cavity was 5.2 cm. The pedicle sharply transitions from a posterior to a posterior-superior course 0.93 cm superior (range: 0.5-1.9 cm) and 0.04 cm posterior (range: 1.4 cm posterior-0.7 cm anterior) to the spine of Henle. Branching occurred in 26 of 69 pedicles (38%), and 20 of 31 (65%) branches were oriented posteriorly. If temporalis muscle fibers are not incorporated into the flap, the thickness is roughly three times that of a standard temporalis fascia graft. CONCLUSION: The muscular branch of the middle temporal artery is reliably identified in the periosteum deep to the posterior aspect of the temporalis muscle, and this vessel is sufficiently robust to provide axial blood supply to a rotational periosteal flap that has sufficient thickness and length to allow a variety of applications in otologic surgery. LEVEL OF EVIDENCE: NA. Laryngoscope, 126:1426-1432, 2016.


Assuntos
Procedimentos Cirúrgicos Otológicos/métodos , Periósteo/transplante , Procedimentos de Cirurgia Plástica/métodos , Retalhos Cirúrgicos/irrigação sanguínea , Artérias Temporais/anatomia & histologia , Adulto , Cadáver , Dissecação/métodos , Humanos , Artérias Temporais/cirurgia , Músculo Temporal/irrigação sanguínea , Músculo Temporal/cirurgia
8.
Nephrology (Carlton) ; 20(3): 117-23, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25388805

RESUMO

Rodent models of renal physiology and pathology are crucial to our understanding of the molecular, histological and functional sequelae that contribute to kidney diseases. One of the most important measures of renal function is glomerular filtration rate (GFR). While the accurate determination of GFR is pivotal to understanding the progression of disease and/or the benefits of treatment strategies, in rodents the conventional methods for assessment of GFR are inconvenient and cumbersome, not the least because they involve stress and often anaesthesia. The legitimacy of assay-based assessment of plasma and urine markers of GFR in mice has also been heavily scrutinized for their insensitivity to minor declines in GFR and inaccurate detection of renal biomarkers. While infusion-based clearance methods of GFR assessment are thus the gold standard in terms of accuracy, they are limited by the fact that they are primarily non-recovery procedures. This presents a dilemma when trying to document the progression of renal disease, as these measures cannot be taken in the same experimental subject. Here we review a technique of transcutaneous measurement of fluorescein isothiocyanate-labelled sinistrin to calculate GFR in small rodents, using a non-invasive clearance device (NIC-Kidney Device). This is a recently validated non-invasive technique for measuring GFR in small rodents that allows for the real-time measurement of GFR in conscious animals, without the need for plasma and urine assays.


Assuntos
Tamanho Corporal , Taxa de Filtração Glomerular , Rim/fisiologia , Animais , Fluoresceínas/farmacocinética , Corantes Fluorescentes/farmacocinética , Rim/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais , Modelos Biológicos , Oligossacarídeos/farmacocinética , Reprodutibilidade dos Testes , Espectrometria de Fluorescência
9.
Surgery ; 156(3): 584-90, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24931283

RESUMO

INTRODUCTION: Minimally invasive parathyroidectomy is successful in achieving cure for most patients with primary hyperparathyroidism. Most surgeons rely on preoperative imaging as part of the workup for localization. Ultrasonography and sestamibi are the 2 most commonly used preoperative imaging studies. When these 2 studies are positive and concordant the preoperative localization is straightforward. However, when ≥1 of these studies is negative, the preoperative localization is suspect. We hypothesize that the yield of useful localizing information from "negative" sestamibi scans can be increased in certain situations. Specifically, in cases where the thyroid lobe length seen on sestamibi is discordant from the lobe length of the ultrasonography, this often represents a "hidden" parathyroid adenoma. If our hypothesis is correct, this could lead to decreased resource utilization in cases of nonlocalized parathyroid adenomas. METHODS: We retrospectively analyzed our database of patients with primary hyperparathyroidism who underwent parathyroidectomy from 2005 to 2011. The anteroposterior views of early phase sestamibi were analyzed for thyroid lobe lengths. A ratio of the length of the right lobe to left lobe was calculated. The thyroid lobe lengths on ultrasonography were measured and similar ratios were calculated. The difference in ratios between sestamibi and ultrasonography was calculated for each patient. A difference in ratios from sestamibi and ultrasonography that corresponded with a "hidden" parathyroid on the side of the additional length on sestamibi at the time of surgery was considered a positive finding. When the difference in ratios from the 2 images did not correspond with a "hidden" parathyroid at the time of operation, it was considered a negative finding. RESULTS: There were 59 patients with single-gland disease, negative sestamibi, and images available for review. There were 32 patients (54%) with the positive finding of a "hidden" parathyroid corresponding with a difference in thyroid lobe length ratios from sestamibi and ultrasonography. The overall mean difference in ratios between sestamibi and ultrasonography was 0.37 ± 0.32. The mean ratio difference in the group of patients with a negative "hidden" parathyroid was 0.11 ± 0.02, and the mean ratio difference in the group of patients with a positive "hidden" parathyroid was 0.58 ± 0.05 (P < .001). When a difference in ratios of ≥0.23 was obtained, this predicted a "hidden" parathyroid with a sensitivity of 93.8% and specificity of 85.2%. There were 39 patients with multigland disease, negative sestamibi, and images available for review. None of these patients had a ratio difference of ≥0.23. The mean ratio difference for patients with multigland disease was significantly lower than that of the single-gland disease (0.08 ± 0.06 vs 0.37 ± 0.32; P < .001). CONCLUSION: Discordance between thyroid lobe lengths on the early phase sestamibi compared with ultrasonography has led to successful preoperative identification of parathyroid adenomas, even though the sestamibi was traditionally read as negative. This finding has not been previously described, seems to be reliable, and can lead to improved preoperative localization and decreased resource utilization in this subset patients.


Assuntos
Hiperparatireoidismo Primário/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Adulto , Idoso , Estudos de Coortes , Reações Falso-Negativas , Feminino , Humanos , Hiperparatireoidismo Primário/cirurgia , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Neoplasias das Paratireoides/cirurgia , Paratireoidectomia , Cintilografia , Estudos Retrospectivos , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia
10.
J Appl Psychol ; 99(1): 151-61, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24060158

RESUMO

Incivility between customers and employees is common in many service organizations. These encounters can have negative outcomes for employees, customers, and the organization. To date, researchers have tended to study incivility as an aggregated and accumulated phenomenon (entity perspective). In the present study, we examined incivility as it occurs during a specific service encounter (event perspective) alongside the entity perspective. Using a mixed-method multilevel field study of customer service interactions, we show that individual customer incivility encounters (i.e., events) trigger employee incivility as a function of the employee's overall accumulated impression of the (in)civility in his or her customer interactions, such that the effects are more pronounced among employees who generally perceive their customer interactions to be more versus less civil. We also find that these interactive effects occur only among employees who are lower (vs. higher) in negative affectivity. Our results show that, in order to expand the understanding of customer incivility, it is important to study the incivility encounter, the social context in which negative customer interactions occur, and individual differences.


Assuntos
Afeto/fisiologia , Comportamento do Consumidor , Emprego/psicologia , Hostilidade , Relações Interpessoais , Adulto , Comércio , Feminino , Humanos , Masculino
11.
Arch Facial Plast Surg ; 14(3): 189-92, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22801763

RESUMO

OBJECTIVE: To determine the quantitative effects of Z-plasty vs spreader grafts on nasal valve surface area. METHODS: Eight fresh cadaver heads were used that provided 16 total nasal valve procedures. Surgical sides were randomized, and Z-plasty was performed on 8 valves and endonasal spreader grafts were performed on 8 valves. The minimal cross-sectional area at the level of the nasal valve was measured preoperatively and postoperatively using acoustic rhinometry. We then compared Z-plasty and spreader grafts using a Wilcoxon signed rank test. RESULTS: The mean nasal surface area at the nasal valve before Z-plasty was 1.37 cm(2) (range, 0.39-2.25 cm(2)) and after Z-plasty was 1.95 cm(2) (range, 1.08-2.62 cm(2)). The mean surface area at the nasal valve before spreader grafts was 1.15 cm(2) (range, 0.75-1.48 cm(2)) and after spreader grafts was 1.48 cm(2) (0.95-1.95 cm(2)). This correlates with a mean increase in the nasal valve surface area of 65% when Z-plasty was performed (95% CI, 28%-88%; P = .007) and 31% when a spreader graft was performed (95% CI, 15%-54%; P = .01). CONCLUSIONS: Z-plasty and spreader grafts were shown to increase nasal valve surface area. Z-plasty seems to increase nasal valve surface area more than spreader grafts.


Assuntos
Cavidade Nasal/cirurgia , Cirurgia Endoscópica por Orifício Natural/métodos , Rinoplastia/métodos , Retalhos Cirúrgicos , Humanos , Cavidade Nasal/anatomia & histologia , Técnicas de Sutura
12.
Cytokine ; 58(3): 448-54, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22450225

RESUMO

Prior studies showing that treatment of head and neck squamous cell carcinoma (HNSCC) patients with 1α,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] stimulated intratumoral immune infiltration were extended to analysis of cytokine profiles in the periphery and in oral tissues. Most prominent was the disparity between cytokine levels in plasma and in either pathologically normal oral tissue or HNSCC tissue from patients that were untreated or treated with 1,25(OH)(2)D(3). Levels of IL-6 and IL-10, but not IL-2, IFN-γ or TNF-α, tended to be increased in the plasma of HNSCC patients and 1,25(OH)(2)D(3) further increased plasma levels of all of these cytokines. While these cytokines tended to be increased in HNSCC tissue, 1,25(OH)(2)D(3) resulted in variable cytokine responses that showed a general tendency toward further increased levels. Levels of IL-8 and VEGF were increased in plasma and tissue of untreated HNSCC patients, and were further increased in plasma, but not in tissues, of patients treated with 1,25(OH)(2)D(3). Levels of IL-1α and IL-1ß were similar in plasma of controls and HNSCC patients, but were increased in HNSCC tissues. In contrast to that seen in plasma where 1,25(OH)(2)D(3) increased levels of IL-1α and IL-1ß, this was not seen in tissue following 1,25(OH)(2)D(3) treatment. These results show a discordant relationship between systemic and intratumoral cytokine profiles and suggest a tendency of 1,25(OH)(2)D(3)to increase a multitude of cytokines within tumor tissue.


Assuntos
Calcitriol/farmacologia , Carcinoma de Células Escamosas/imunologia , Neoplasias de Cabeça e Pescoço/imunologia , Citocinas/sangue , Neoplasias de Cabeça e Pescoço/sangue , Humanos
13.
Cancer Immunol Immunother ; 61(6): 927-39, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22116344

RESUMO

While studies have indicated that squamous cell carcinoma of the head and neck (HNSCC) is associated with immune suppression, these studies did not analyze the immune response at the dysplastic stage. The present study utilized a mouse model of 4-nitroquinoline 1-oxide-induced oral carcinogenesis to examine the alterations in immune phenotype at the premalignant and malignant stages of HNSCC. Cervical lymph nodes of HNSCC-bearing mice were found to contain a greater number of cells, including a greater number of conventional (Tconv) and regulatory (Treg) T cells, compared to cervical lymph nodes of control and premalignant lesion-bearing mice, though the Tconv cells appear to be less proliferative and the Treg cells appear to be less suppressive at the HNSCC stage. Premalignant lesion-bearing mouse lymph nodes consist of a greater percentage of Tconv cells expressing markers for activation, memory, and exhaustion compared to both control and HNSCC-bearing mice. Also, lymph nodes' cells from both premalignant lesion-bearing and HNSCC-bearing mice include increased levels of Th1, Tc1, and Th17 cells, with no differences in levels of Th2 cells, compared to control mice. The data show that while there is the expected increase in immunosuppressive Tregs in lymph nodes when HNSCC is present, there is also an unexpected increase in immune populations usually associated with a beneficial antitumor response, including Tconv cells and Th1 and Tc1 cells. In addition, the results demonstrate that the premalignant stage of HNSCC development is associated with a robust immune response involving an increase in inflammatory Th1, Tc1, and Th17 cells.


Assuntos
Carcinoma de Células Escamosas/imunologia , Progressão da Doença , Neoplasias de Cabeça e Pescoço/imunologia , Animais , Carcinoma de Células Escamosas/patologia , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Linfócitos T Citotóxicos/imunologia , Células Th1/imunologia , Células Th17/imunologia
14.
J Appl Psychol ; 93(6): 1335-47, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19025251

RESUMO

Research on the "dark side" of organizational behavior has determined that employee sabotage is most often a reaction by disgruntled employees to perceived mistreatment. To date, however, most studies on employee retaliation have focused on intra-organizational sources of (in)justice. Results from this field study of customer service representatives (N = 358) showed that interpersonal injustice from customers relates positively to customer-directed sabotage over and above intra-organizational sources of fairness. Moreover, the association between unjust treatment and sabotage was moderated by 2 dimensions of moral identity (symbolization and internalization) in the form of a 3-way interaction. The relationship between injustice and sabotage was more pronounced for employees high (vs. low) in symbolization, but this moderation effect was weaker among employees who were high (vs. low) in internalization. Last, employee sabotage was negatively related to job performance ratings.


Assuntos
Relações Interpessoais , Princípios Morais , Cultura Organizacional , Comportamento Social , Meio Social , Identificação Social , Justiça Social , Local de Trabalho/psicologia , Adulto , Feminino , Humanos , Masculino
15.
Opt Express ; 16(23): 18942-9, 2008 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-19581985

RESUMO

In this paper we first contrast classical and CNC polishing techniques in regard to the repetitiveness of the machine motions. We then present a pseudo-random tool path for use with CNC sub-aperture polishing techniques and report polishing results from equivalent random and raster tool-paths. The random tool-path used - the unicursal random tool-path - employs a random seed to generate a pattern which never crosses itself. Because of this property, this tool-path is directly compatible with dwell time maps for corrective polishing. The tool-path can be used to polish any continuous area of any boundary shape, including surfaces with interior perforations.


Assuntos
Algoritmos , Desenho Assistido por Computador , Lentes , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Opt Express ; 14(24): 11787-95, 2006 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-19529601

RESUMO

The Precessions process polishes complex surfaces from the ground state preserving the ground-in form, and subsequently rectifies measured form errors. Our first paper introduced the technology and focused on the novel tooling. In this paper we describe the unique CNC machine tools and how they operate in polishing and correcting form. Experimental results demonstrate both the '2D' and '2(1/2)D' form-correction modes, as applied to aspheres with rotationally-symmetric target-form.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...