DICOM file format has better radiographic image quality than other file formats: an objective study

Abstract This study aimed to assess the influence of the file format on the image quality parameters (image noise, brightness, and uniformity) of periapical radiographs acquired with different digital systems. Radiographic images of an acrylic phantom were acquired with two digital systems - Digora Toto and Express, and exported into five different file formats - TIFF, BMP, DICOM, PNG, and JPEG. Image noise, image brightness (mean of gray values), and image uniformity (standard deviation of gray values) were evaluated in all images. A two-way analysis of variance with Tukey's test as a post-hoc test was used to compare the results, considering the file formats and radiographic systems as the studied factors. A significance level of 5% was adopted for all analyses. The DICOM image file format presented lower image noise, higher brightness (higher mean gray values), and greater image uniformity (p<0.001) than the other file formats, which did not differ from each other for both digital radiography systems (p>0.05). The Express system revealed lower image noise and greater image uniformity than the Digora Toto system regardless of the image file format (p<0.001). Moreover, the Express showed higher brightness than the Digora Toto for all image file formats (p<0.001), except for the DICOM image file format, which did not significantly differ between the digital radiography systems tested (p>0.05). The DICOM image file format showed lower image noise, higher brightness, and greater image uniformity than the other file formats (TIFF, BMP, PNG, and JPEG) in both digital radiography systems tested.

Resumo Este estudo teve como objetivo avaliar a influência do formato do arquivo nos parâmetros de qualidade de imagem (ruído de imagem, brilho e uniformidade) de radiografias periapicais adquiridas com diferentes sistemas digitais. As imagens radiográficas de um fantoma de acrílico foram adquiridas com dois sistemas digitais - Digora Toto e Express, e exportadas em cinco formatos de arquivo diferentes - TIFF, BMP, DICOM, PNG e JPEG. O ruído da imagem, o brilho da imagem (média dos valores de cinza) e a uniformidade da imagem (desvio padrão dos valores de cinza) foram avaliados em todas as imagens. A análise de variância (ANOVA) bidirecional com o teste post-hoc de Tukey foi aplicada para comparar os resultados, considerando os formatos de arquivo e os sistemas radiográficos como os fatores estudados. Um nível de significância de 5% foi adotado para todas as análises. O formato de arquivo de imagem DICOM apresentou menor ruído de imagem, maior brilho (maiores valores médios de cinza) e maior uniformidade de imagem (p<0,001) do que os outros formatos de arquivo, que não diferiram entre si para ambos os sistemas de radiografia digital (p>0,05). O sistema Express apresentou menor ruído de imagem e maior uniformidade de imagem que o sistema Digora Toto, independentemente do formato do arquivo de imagem (p<0,001). Além disso, o Express mostrou maior brilho do que o Digora Toto para todos os formatos de arquivo de imagem (p<0,001), exceto para o formato de arquivo de imagem DICOM, que não diferiu significativamente entre os sistemas de radiografia digital testados (p>0,05). O formato de arquivo de imagem DICOM mostrou menor ruído de imagem, maior brilho e maior uniformidade de imagem do que os outros formatos de arquivo (TIFF, BMP, PNG e JPEG) em ambos os sistemas de radiografia digital testados.

A novel method of objectively detecting tooth ankylosis using cone-beam computed tomography: A laboratory study

Purpose@#The aim of this study was to objectively detect simulated tooth ankylosis using a novel method involving cone-beam computed tomography (CBCT). @*Materials and Methods@#Tooth ankylosis was simulated in single-rooted human permanent teeth, and CBCT scans were acquired at different current levels (5, 6.3, and 8 mA) and voxel sizes (0.08, 0.125, and 0.2). In axial reconstructions, a line of interest was perpendicularly placed over the periodontal ligament space of 21 ankylosed and 21 non-ankylosed regions, and the CBCT grey values of all voxels along the line of interest were plotted against their corresponding X-coordinates through a line graph to generate a profile. The image contrast was increased by 30% and 60% and the profile assessment was repeated. The internal area of the resulting parabolas was obtained from all images and compared between ankylosed and non-ankylosed regions under different contrast enhancement conditions, voxel sizes, and mA levels using multi-way analysis of variance with the Tukey post hoc test (α=0.05). @*Results@#The internal area of the parabolas of all non-ankylosed regions was significantly higher than that of the ankylosed regions (P0.05). @*Conclusion@#The proposed novel method revealed a relevant degree of applicability in the detection of simulated tooth ankylosis; increased image contrast led to greater detectability.

Incidental finding of bullous concha by cone beam computed tomography / Hallazgo incidental de concha bullosa por tomografía computarizada de haz cónico

Abstract This study aimed to describe the imaging aspects of a concha bullosa discovered incidentally by means of cone-beam computed tomography (CBCT) imaging. A female patient underwent a CBCT exam, and a bilateral extensive pneumatization of the middle concha was verified, presenting a larger dimension of the right side and a deviated septum. The patient reported nasal obstruction and loss of smell. The CBCT for covering the maxillofacial region allowed the discovery of this incidental finding, allowing the patient to be referred for appropriate treatment.

Resumen Este estudio tuvo como objetivo describir los aspectos imaginológicos de una concha bullosa hallada incidentalmente por medio de imágenes de tomografía computarizada de haz cónico (TCHC). Una paciente de sexo femenino fue sometida a examen de TCHC y se verificó una neumatización extensa bilateral de la concha media, presentando una mayor dimensión del lado derecho, asi como desvío del tabique. El paciente refirió obstrucción nasal y pérdida del olfato. La TCHC de la región maxilofacial permitió localizar este hallazgo incidental, permitiendo derivar al paciente para el tratamiento adecuado.

Structural complexity of the craniofacial trabecular bone in multiple myeloma assessed by fractal analysis

Purpose@#This study aimed to evaluate the structural complexity of craniofacial trabecular bone in multiple myeloma by fractal analysis of panoramic and lateral skull radiography, and to compare the fractal dimension values of healthy patients (HPs), pre-treatment patients (PTPs), and patients during bisphosphonate treatment (DTPs). @*Materials and Methods@#Pairs of digital panoramic and lateral skull radiographs of 84 PTPs and 72 DTPs were selected. After application of exclusion criteria, 43 panoramic and 84 lateral skull radiographs of PTPs, 56 panoramic and 72 lateral skull radiographs of DTPs, and 99 panoramic radiographs of age- and sex-matched HPs were selected. The fractal dimension values from panoramic radiographs were compared among HPs, PTPs, and DTPs and between anatomical locations within patient groups using analysis of variance with the Tukey test. Fractal dimension values from lateral skull radiographs were compared between PTPs and DTPs using the Student t-test. Pearson correlation coefficients were used to assess the relationship between the mandible from panoramic radiographs and the skull from lateral skull radiographs. Intra-examiner agreement was assessed using intraclass correlation coefficients (α=0.05). @*Results@#The fractal dimension values were not significantly different among HPs, PTPs, and DTPs on panoramic radiographs or between PTPs and DTPs on lateral skull radiographs (P>0.05). The mandibular body presented the highest fractal dimension values (P≤0.05). The fractal dimension values of the mandible and skull in PTPs and DTPs were not correlated. @*Conclusion@#Fractal analysis was not sensitive for distinguishing craniofacial trabecular bone complexity in multiple myeloma patients using panoramic and lateral skull radiography.

Effects of exercise training on autonomic modulation and mood symptoms in patients with obstructive sleep apnea

We evaluated the effects of exercise training (ET) on the profile of mood states (POMS), heart rate variability, spontaneous baroreflex sensitivity (BRS), and sleep disturbance severity in patients with obstructive sleep apnea (OSA). Forty-four patients were randomized into 2 groups, 18 patients completed the untrained period and 16 patients completed the exercise training (ET). Beat-to-beat heart rate and blood pressure were simultaneously collected for 5 min at rest. Heart rate variability (RR interval) was assessed in time domain and frequency domain (FFT spectral analysis). BRS was analyzed with the sequence method, and POMS was analyzed across the 6 categories (tension, depression, hostility, vigor, fatigue, and confusion). ET consisted of 3 weekly sessions of aerobic exercise, local strengthening, and stretching exercises (72 sessions, achieved in 40±3.9 weeks). Baseline parameters were similar between groups. The comparisons between groups showed that the changes in apnea-hypopnea index, arousal index, and O2 desaturation in the exercise group were significantly greater than in the untrained group (P<0.05). The heart rate variability and BRS were significantly higher in the exercise group compared with the untrained group (P<0.05). ET increased peak oxygen uptake (P<0.05) and reduced POMS fatigue (P<0.05). A positive correlation (r=0.60, P<0.02) occurred between changes in the fatigue item and OSA severity. ET improved heart rate variability, BRS, fatigue, and sleep parameters in patients with OSA. These effects were associated with improved sleep parameters, fatigue, and cardiac autonomic modulation, with ET being a possible protective factor against the deleterious effects of hypoxia on these components in patients with OSA.

GM1 gangliosidosis: a case report / Gangliosidose GM1: um relato de caso

RESUMEN La gangliosidosis GM1 es un trastorno lisosomal caracterizada por la acumulación de gangliósido GM1 (glucoesfingolípido) en el sistema nervioso central (SNC) y visceral, debido a la deficiencia de la enzima beta-galactosidase (hidrolasa lisosomal). Afecta principalmente al SNC y las vísceras y produce importantes anomalías esqueléticas, que a menudo ocurren con la presencia de linfocitos vacuolados en la muestra de la sangre periférica o médula ósea. Tiene tres formas de presentación, lo que dificulta aún más su identificación debido al amplio espectro clínico. El presente estudio tiene como objetivo describir un caso de gangliosidosis GM1 en un paciente masculino, nacido a las 38 semanas. Hasta el momento, no existe un tratamiento efectivo para la gangliosidosis GM1, es decir, el portador de la enfermedad solo recibe medidas sintomáticas y paliativas. Por tanto, el diagnóstico precoz de la enfermedad es de suma importancia, ya que su única forma de prevención, actualmente, es a través del consejo genético.

Experiencia pedagógica: escenario de simulación de entrevista psiquiátrica con la participación de actores del grupo de teatro representativo Altergesto / A Teaching Experience: Psychiatric Interview on a Simulated Scenario With the Participation of Actors of the Altergesto Theater Group

Introducción: La simulación se ha empleado como herramienta de aprendizaje en diferentes disciplinas y profesiones, como la medicina y sus especialidades. Su utilidad está directamente relacionada con la integración a los objetivos, contenidos, metodologías y recursos específicos en cada área del conocimiento. Objetivo: Describir el desarrollo de una experiencia pedagógica implementada en la Pontificia Universidad Javeriana Cali con los estudiantes de Conducta Humana II del programa de Medicina entre 2012 y 2013. Dicha experiencia se apoyó en la participación de pacientes simulados por actores del grupo representativo Altergesto, que fueron entrevistados por los estudiantes con la supervisión de los psiquiatras docentes de la materia, utilizando el Hospital Simulado de la Universidad. Métodos: Recuento histórico del desarrollo de la secuencia didáctica desde el primer semestre de 2012 hasta el segundo semestre de 2013, planteamiento de los objetivos pedagógicos y descripción de la estrategia de enseñanza-aprendizaje. Resultados: Se realizaron 158 entrevistas en un periodo de 2 años, en el transcurso de los cuales fue necesario plantear soluciones metodológicas para adaptar la secuencia pedagógica a los contenidos y los objetivos de la materia. Conclusiones: La simulación de alta fidelidad, integrando a actores que representan a los pacientes psiquiátricos y la tecnología del Hospital Simulado, resultó útil para lograr el cumplimiento de los objetivos propuestos en el curso de Conducta Humana II del programa de Medicina de la Pontificia Universidad Javeriana Cali. Paralelamente, la construcción de la experiencia como un proyecto interdisciplinario y el enfoque práctico de esta estrategia pueden impactar en las dimensiones cognitivas, emocionales y conductuales de los significativo. Es necesario construir una base de datos de fácil acceso con el material recopilado y estudiar los efectos de esta estrategia en la formación de los estudiantes a largo plazo.

Introduction: Simulation has been used as a learning tool in different disciplines and pro-Simulation scenario fessions, including medicine and its specialties. Its usefulness is directly related to the Psychiatric interview integration of objectives, contents, methodologies and specific resources in each area of Simulated patient actor knowledge. Objective: To describe the development of an educational experience implemented in the Pontificia Universidad Javeriana Cali (Cali, Colombia) with medical students of Human Behavior II program, between 2012 and 2013. This experience was performed with simulated patients played by actors of the Altergesto theater group, that were interviewed by students under the supervision of psychiatrists and teachers of the subject, using the Simulated Hospital of the University. Methods: A historical development recall of the teaching sequence was made from the first half of 2012 to the second half of 2013, a statement of pedagogical objectives, and a description of the teaching-learning strategies. Results: 158 interviews were conducted over a period of two years during which it was necessary to raise methodological solutions to adapt this teaching sequence to the content and objectives of the subject. Conclusions: The high-fidelity simulation, integrating actors who represent psychiatric patients mixed with the technology of a Simulated Hospital was useful to achieve compliance with the objectives proposed in the course of Human Behavior II, as a part of the program of Medicine at the Pontificia Universidad Javeriana Cali. In parallel, the construction of experience as an interdisciplinary project and the practical approach of this strategy may impact on cognitive, emotional, behavioral dimensions of the participants, encouraging meaningful learning. An easy access database for the collected material and the study of the effects of this strategy in the formation of long-term students is needed.

Gastrointestinal parasites of swine raised in different management systems in the State of Rio de Janeiro, Brazil / Parasitos gastrintestinais de suínos criados sob diferentes sistemas de manejo no Estado do Rio de Janeiro

From 2012 to 2013 were surveyed gastrointestinal parasites from pig farms located in different municipalities in the state of Rio de Janeiro. Fecal samples from 790 pigs were collected from the rectum on 88 family farms and 702 farms with industrial production. The samples were subjected to Faust et al., Sheather, Ritchie, Lutz and direct examination faecal techniques. The estimated parasite prevalence was 93.1% in family farms and 59.1% in industrial farms. Balantidium coli, coccidia and Entamoeba sp. were the parasites with the highest frequencies, and the male and female reproductive categories and fatteners pigs the most infected (p<0.05). Trophozoites of B. coli were most evident in stool samples from semi-solid followed by solid and diarrheal consistencies. Strongyles eggs and Trichuris suis have been detected exclusively in family farms. Ascaris suum eggs and Strongyloides ransomi showed low frequency. The high degree of parasitism, especially protozoa, indicates the need to reassess the management of pigs in both types of production...

De 2012 a 2013 foram pesquisados parasitos gastrintestinais de suínos de granjas localizadas em diferentes municípios do estado do Rio de Janeiro. Amostras fecais de 790 suínos foram coletadas da ampola retal, sendo 88 de propriedades familiares e 702 de granjas com produção industrial. As amostras foram submetidas às técnicas de Faust et al., Sheather, Ritchie, Lutz e exame direto. A prevalência estimada foi de 93,1% nas granjas familiares e 59,1% nas granjas industriais. Balantidium coli, coccídios e Entamoeba sp. foram os parasitos que apresentaram as maiores frequências, sendo as categorias machos e fêmeas reprodutoras e leitões de terminação as mais infectadas (p<0,05). Trofozoítas de B. coli foram mais evidenciados nas amostras fecais de consistências semi-sólida, seguida pelas fezes com consistências sólida e diarreica. Ovos de estrongilídeos e Trichuris suis foram detectados exclusivamente em criações familiares. Ovos de Ascaris suum e de Strongyloides ransomi apresentaram baixa frequência. O alto grau de parasitismo, principalmente de protozoários, indica a necessidade de reavaliação do manejo dos suínos em ambos os tipos de produção...

Assessment of CT numbers in limited and medium field-of-view scans taken using Accuitomo 170 and Veraviewepocs 3De cone-beam computed tomography scanners

PURPOSE: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. MATERIALS AND METHODS: Tubes containing solutions with different concentrations of K2HPO4 were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the K2HPO4 solutions were measured. The relationship between CT number and K2HPO4 concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. RESULTS: The relationship between K2HPO4 concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. CONCLUSION: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.

Imagem radiográfica da cavidade torácica de cães Golden Retriever acometidos pela distrofia muscular / Radiologic images of the thoracic cavity of Golden Retriever dogs affected by muscular dystrophy

A distrofia muscular de Duchenne (DMD) é uma doença de origem genética, cuja principal manifestação clínica é enfraquecimento e atrofia progressiva dos músculos. Os cães da raça Golden Retriever podem apresentar distrofia muscular, com características genotípicas e fenotípicas muito próximas à distrofia muscular humana, sendo considerado o modelo animal mais apropriado para o estudo da DMD. Foram realizadas radiografias torácicas látero-laterais e dorsoventrais de 10 cães Golden Retriever afetados pela distrofia muscular, com o objetivo de relatar as alterações radiográficas associadas a essa patologia. O exame radiográfico da cavidade torácica evidenciou: (a) padrão pulmonar intersticial e alveolar predominante, (b) um quadro de pneumonia e edema pulmonar em fase inicial, (c) a cardiomegalia como o principal achado de comprometimento circulatório na cavidade torácica, (d) O megaesôfago torácico foi observado deslocando a traquéia e silhueta cardíaca ventralmente e, (e) a cúpula diafragmática apresentou modificação morfológica, mostrando protrusão para o interior da cavidade torácica e hérnia hiatal, com deslocamento do estômago para o espaço mediastino caudal. Os achados de necropsia evidenciaram efusão pleural e enfisema pulmonar e lesões compatíveis com processos degenerativos e metaplásicos da musculatura diafragmática e intercostal. A avaliação radiográfica constituiu-se como um meio diagnóstico auxiliar essencial na identificação de doença cardíaca e respiratória em cães Golden Retriever acometidos pela Distrofia Muscular, capaz de identificar processos pneumônicos primários, permitindo o estabelecimento de terapêutica adequada de tratamento, com prognóstico reservado nos estágios mais avançados desta alteração.

Duchenne Muscular Dystrophy (DMD) is a genetic disorder with clinical signs of muscular weaknesses and progressive atrophy. Golden Retriever dogs show similar genotypic and phenotypic characteristics to Human Muscular Dystrophy and are considered a proper animal model for DMD studies. Latero-lateral and dorso-ventral thoracic radiographies were obtained from 10 Golden Retriever dogs affected by muscular dystrophy, to investigate possible radiographic alterations. Thorax radiographic examination revealed (a) interstitial and alveolar pattern, (b) initial phases of pneumonia and pulmonary edema, (c) cardiomegaly as a principal alteration in the thoracic cavity, (d) megaesophagus displacing the trachea and heart silhouette, and (e) cranial protrusion of the diaphragm lining into the thorax with development of a hiatus hernia displacing the stomach to the caudal mediastinum. Postmortem examination showed pleural effusion, pulmonary emphysema, degenerative and metaplasic processes in the diaphragm and intercostal muscles. Radiographic examination was considered essential for the diagnosis of cardiac and respiratory disease in Golden Retriever dogs affected by muscular dystrophy, and to identify the primary pulmonary process and to provide the establishment of suitable therapeutic treatment, with a reserved prognosis in advanced stage of the disease.

Influência dos exercícios perineais e dos cones vaginais, associados à correção postural, no tratamento da incontinência urinária feminina / Influence of perineal exercises and vaginal cones in association with corrective postural exercises, on female urinary incontinence treatment

OBJETIVO: Verificar a influência dos exercícios perineais e dos cones vaginais, em associação aos exercícios posturais corretivos para a normalização estática da pelve, no tratamento da incontinência urinária feminina. MÉTODOS: Foram avaliadas 12 mulheres apresentando queixa de incontinência urinária, com idade média de 52,3 ± 9,7, submetidas a 10 sessões fisioterapêuticas, duas vezes na semana, divididas em dois grupos: Grupo A: n = 6, utilizando exercícios perineais e Grupo B: n = 6, utilizando cones vaginais. Ambos os grupos realizaram exercícios posturais para correção estática da pelve, conforme alterações de cada participante. Foram coletados os seguintes dados, antes e após intervenção: grau de contração muscular do períneo, pela Avaliação Funcional do Assoalho Pélvico (AFA); perda quantitativa de urina, mensurada pelo teste da almofada (Pad-Test), e sensações de umidade e desconforto, verificadas pelas Escalas Visuais Análogas (EVA). Os dados posturais foram coletados através do exame estático da pelve, exame de flexibilidade das cadeias musculares e avaliação postural. RESULTADOS: Na comparação dos dados pré e pós-intervenção, foi observado, para ambos os grupos, diminuição estatisticamente significativa da perda urinária (p < 0,05), ganho de contração muscular do assoalho pélvico e diminuição significativa da sensação de umidade. O grau de sensação de desconforto, pós-intervenção, foi significativamente menor para o grupo de exercícios perineais. O equilíbrio estático pélvico foi corrigido na maioria das voluntárias e houve ganho de flexibilidade das cadeias musculares. CONCLUSÃO: A correção estática da pelve, através dos exercícios posturais, constitui uma modalidade efetiva de intervenção na IU feminina, quando associada à reeducação perineal.

OBJECTIVE: To investigate the influence of perineal exercises and vaginal cones in association with corrective postural exercises for static normalization of the pelvis, on female urinary incontinence treatment. METHOD: Twelve women with urinary incontinence complaints (mean age: 52.3 ± 9.7) were assessed via 10 physical therapy sessions, twice a week. They were divided into two groups: Group A (n = 6) underwent perineal exercises, while Group B (n = 6) used vaginal cones. Both groups performed postural exercises for static correction of the pelvis, in accordance with each patient's abnormalities. The following data were collected before and after the intervention: degree of perineal muscle contraction, via functional evaluation of the pelvic floor (FEPF); quantitative urinary loss, using the pad test; and sensations of dampness and discomfort, via a visual analog scale (VAS). Postural data were collected using the static pelvic test, muscle chain flexibility test and postural evaluation. RESULTS: Comparing the data before and after the intervention, there were statistically significant decreases in urinary loss (p < 0.05) for both groups. There were gains in pelvic floor muscle contraction and significant decreases in the sensation of dampness. The degree of discomfort following the intervention was significantly lower for the group that did perineal exercises. The pelvic static balance was corrected in most of the volunteers and there were gains in muscle chain flexibility. CONCLUSIONS: Static correction of the pelvis by means of postural exercises is an efficient method for female urinary incontinence treatment when associated with perineal muscle training.

Uso de extrato de nim no controle de acaríase por Myobia musculi Schranck (Acari: Miobidae) e Myocoptes musculinus Koch (Acari: Listrophoridae) em camundongos (Mus musculus var. albina L.) / Use of neem extract in the control of acariasis by Myobia musculi Schranck (Acari: Miobidae) and Myocoptes musculinus Koch (Acari: Listrophoridae) in mice (Mus musculus var. albina L.)

O objetivo do trabalho foi avaliar a ação acaricida do extrato de nim sobre a forma de pomada, no tratamento da acaríase em camundongos (Mus musculus var. albina L.) naturalmente infestados por Myobia musculi Schrank e Myocoptes musculinus Koch. Foram selecionados 20 animais parasitados e distribuídos em quatro grupos: controle (vaselina), nim a 5 por cento, 10 por cento e 20 por cento. Os animais foram submetidos ao tratamento a cada 48h e mantidos confinados em gaiolas, com alimento e água ad libitum e acompanhados diariamente ao longo de 24 dias. Houve redução significativa do número médio de ácaros recuperados a partir de 96h na concentração de nim a 20 por cento, em comparação com as demais concentrações (P < 0,05). A partir das 120h da aplicação, as concentrações de 10 por cento e 20 por cento também apresentaram resultados significativos quando comparados com o grupo controle (P < 0,05 e P < 0,01; respectivamente). A partir de 168h, os animais tratados com as concentrações de 10 por cento e 20 por cento mostraram resultados significativos (P < 0,01) em comparação com o controle e os ácaros não foram mais observados. Após 216h da aplicação, a pelagem estava totalmente recuperada e os animais permaneceram livres da infestação, nas concentrações de 10 por cento e 20 por cento (P < 0,01). A pomada de nim apresentou atividade acaricida nas concentrações de 10 por cento e 20 por cento em camundongo quando aplicada topicamente, além de mostrar boa atividade flogística, cicatrizante e não desenvolver efeitos colaterais.