RESUMEN
This Letter presents the first observation on how a strong, 500 kG, externally applied B field increases the mode-two asymmetry in shock-heated inertial fusion implosions. Using a direct-drive implosion with polar illumination and imposed field, we observed that magnetization produces a significant increase in the implosion oblateness (a 2.5× larger P2 amplitude in x-ray self-emission images) compared with reference experiments with identical drive but with no field applied. The implosions produce strongly magnetized electrons (ω_{e}τ_{e}â«1) and ions (ω_{i}τ_{i}>1) that, as shown using simulations, restrict the cross field heat flow necessary for lateral distribution of the laser and shock heating from the implosion pole to the waist, causing the enhanced mode-two shape.
RESUMEN
A subset of antiandrogen compounds, the N-aryl-3,3,3-trifluoro-2-hydroxy-2-methylpropanamides 1, were found to activate ATP sensitive potassium channels (KATP) and represent a new class of potassium channel openers (PCOs). A structure-activity relationship was carried out on the western region of this series with the goal of obtaining an activator of the ATP sensitive potassium channel suitable for use in the treatment of urge urinary incontinence. In particular three large 4-(N-aryl) substituents, the (N-phenyl-N-methylamino)sulfonyl, benzoyl, and 4-pyridylsulfonyl moieties, yielded non-antiandrogen, KATP potassium channel openers (39, 41, and 64, respectively) that are bladder selective in an in vivo rat model that simultaneously measures bladder contractions, heart rate, and blood pressure. Substitutions of the aryl rings of 41 and 64 gave several derivatives that also display selectivity in the in vivo rat model; however, none appear to offer a substantial advantage over 41 and 64. The PCO activity of 41 and 64 resides in the (S)-(-) enantiomers. ZD6169, 41(S), has been selected into development for the treatment of urge urinary incontinence.
Asunto(s)
Amidas/química , Canales de Potasio/agonistas , Amidas/farmacología , Amidas/uso terapéutico , Animales , Cricetinae , Técnicas In Vitro , Contracción Muscular , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Ratas , Relación Estructura-Actividad , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/fisiología , Incontinencia Urinaria/tratamiento farmacológicoRESUMEN
BACKGROUND: A compilation of treatment options for impacted teeth is presented to assist dentists in discussing the sequelae of impacted teeth as well as the complications of treatment with their patients. OVERVIEW: A differential diagnosis for an impacted tooth is not possible without clinical assessment. However, an ankylosed tooth or a tooth with failure of its eruption mechanism may be mistaken for an impacted tooth. This review of national and international dental texts, journals and publications concerning impacted teeth spans more than 50 years. PRACTICE IMPLICATIONS: Treatment options for the management of impacted teeth are separated into four categories: observation, intervention, relocation and extraction. The indications, contraindications and complications of each option are presented. This information will help the clinician identify developmental conditions associated with an increased probability of tooth impaction and assess available treatment options.
Asunto(s)
Diente Impactado/terapia , Diagnóstico Diferencial , Humanos , Diente/cirugía , Anquilosis del Diente/diagnóstico , Erupción Ectópica de Dientes/diagnóstico , Técnicas de Movimiento Dental , Diente Impactado/diagnóstico , Diente Supernumerario/diagnóstico , Diente no Erupcionado/diagnósticoRESUMEN
Guided tissue regeneration techniques, which are used in the treatment of certain advanced Class II and Class II furca-involved teeth, have progressed from promising to predictable. However, furca-modification techniques remain important aspects of treatment. Tooth eruption, combined with standard furca-modification techniques, improves the prognosis for both the treated and the adjacent teeth. Continued eruption of periodontally involved molars improves the crown-to-root ratio and maintains the periodontium of the adjacent dentition. These same concepts can be used to treat restoratively compromised molars, many of which were considered hopeless and subsequently extracted. Passive eruption can be useful in treating cases that need less than 3 mm of tooth eruption; orthodontic-active eruption with fixed appliances is advised if more than 3 mm of eruption is desired. Slower eruption rates (2 mm per month) allow the periodontal ligament to repair and the alveolar bone to remodel between orthodontic adjustments (3 to 4 weeks between adjustments). Periodic periodontal maintenance is accomplished during orthodontic treatment. After a retention period (8 weeks), periodontal++ surgery should be performed to reestablish the tooth's biologic width. After surgical wound healing (6 to 8 weeks), the tooth should be restored.
Asunto(s)
Alargamiento de Corona/métodos , Defectos de Furcación/terapia , Técnicas de Movimiento Dental/métodos , Adolescente , Adulto , Análisis del Estrés Dental , Defectos de Furcación/complicaciones , Humanos , Masculino , Diente Molar , Planificación de Atención al Paciente , Fracturas de los Dientes/etiología , Raíz del Diente/lesionesRESUMEN
This hospital-based cross-sectional cohort study examines the clinical and demographic features of neck pain, disability (using the Northwick Park neck pain questionnaire) and relationships to handicap in employment. Of 173 consecutive referrals to a rheumatology clinic with neck pain, 70% had neck/arm pain without neurological involvement, 13% other conditions, 11% nerve involvement and 5% other spinal pain. 141 patients (mean age 50 years) had mechanical or degenerative neck pain, of which 13% was probably work-related and 13% was trauma-related. 44 had taken sickness absence for an average of 30 weeks. Comorbidities were frequent (lumbar pain 51%). Those in work were significantly less disabled than those not working (p = 0.001) and those off sick (p < 0.01). Those reporting sleep disturbance, tearfulness and crying were significantly more disabled (p = 0.0001) than those who did not. Neck pain in secondary care is complicated by physical and emotional comorbidities. Comprehensive management requires a biopsychosocial model of care.
Asunto(s)
Dolor de Cuello/terapia , Adulto , Anciano , Anciano de 80 o más Años , Atención Ambulatoria , Enfermedad Crónica , Estudios de Cohortes , Estudios Transversales , Evaluación de la Discapacidad , Personas con Discapacidad , Empleo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Dolor de Cuello/psicología , Enfermedades Profesionales/etiología , Enfermedades Profesionales/psicología , Enfermedades Profesionales/terapia , Trastornos del Sueño-Vigilia/etiologíaRESUMEN
This is the case report of a 26-year-old black woman with a Class I malocclusion and a skeletal Class II profile and vertical maxillary excess. Extraction spaces were closed, creating a Class II malocclusion to augment anticipated surgery (LeFort I osteotomy and genioplasty). The treatment result provided outstanding occlusal function and optimal facial esthetics. Attention to detail was mandatory, i.e., identify the patient's chief complaint, provide treatment options to resolve the complaint, and treat and maintain the dentition as ideally as possible. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]
Asunto(s)
Maloclusión Clase I de Angle/terapia , Mandíbula/anomalías , Maxilar/cirugía , Ortodoncia Correctiva/métodos , Retrognatismo/cirugía , Adulto , Cefalometría , Mentón/cirugía , Femenino , Humanos , Maloclusión Clase I de Angle/cirugía , Mandíbula/cirugía , Maxilar/patología , Dimensión VerticalRESUMEN
A case report about the orthodontic treatment of a Class III malocclusion in a black man 22 years 8 months old. The patient's chief complaint concerned the space left by the traumatic loss of the maxillary left central incisor. Not desiring changes in facial appearance, the patient sought an orthodontic solution to his problem. An acceptable result was achieved through maxillary expansion and the reduction of mandibular space. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]
Asunto(s)
Oclusión Dental Traumática/terapia , Maloclusión de Angle Clase III/terapia , Ortodoncia Correctiva/métodos , Adulto , Cefalometría , Dentadura Parcial Removible , Humanos , Masculino , Mandíbula/anomalías , Planificación de Atención al Paciente , Prognatismo , Avulsión de DienteRESUMEN
Practitioners are aware of the presence of friction in those orthodontic appliances where relative motion between bracket system and arch wire occurs in ordinary deactivation processes. Numerous comments on friction have appeared in the published dental/orthodontic literature, but little controlled research into the problem has been reported. The objective of this investigation was to evaluate and compare frictional forces generated in an experimental stimulation of the canine-retraction procedure on a continuous arch wire. Six independent variables were chosen for study: arch wire size and shape, bracket width and style, second-order angulation between bracket and passive arch wire, arch wire material, ligature force and type of ligation, and interbracket distances. Frictional resistance was found to be nonlinearly dependent upon bracket/arch wire angulation. With small and generally nonbinding angulations, bracket width and ligature force were the dominant influences on level of friction. As angulations were increased, producing binding between wire and bracket, this variable itself became the controlling parameter. Wire shape and arch wire stiffness in bending, a function of three of the variables studied, apparently exerted substantial influence on frictional-force magnitude at relatively high angulations. The reduced data, together with structural computations, were employed to deduce a minimum frictional-resistance combination of edgewise appliance components.
Asunto(s)
Análisis del Estrés Dental , Aparatos Ortodóncicos , Fenómenos Biomecánicos , Equipo Dental , Análisis del Estrés Dental/instrumentación , Elasticidad , Cinética , Análisis de Regresión , Estrés Mecánico , Propiedades de Superficie , Técnicas de Movimiento DentalRESUMEN
The Caenorhabditis elegans HSN motor neurons permit genetic analysis of neuronal development at single-cell resolution. The egl-5 Hox gene, which patterns the posterior of the embryo, is required for both early (embryonic) and late (larval) development of the HSN. Here we show that ham-2 encodes a zinc finger protein that acts downstream of egl-5 to direct HSN cell migration, an early differentiation event. We also demonstrate that the EGL-43 zinc finger protein, also required for HSN migration, is expressed in the HSN specifically during its migration. In an egl-5 mutant background, the HSN still expresses EGL-43, but expression is no longer down-regulated at the end of the cell's migration. Finally, we find a new role in early HSN differentiation for UNC-86, a POU homeodomain transcription factor shown previously to act downstream of egl-5 in the regulation of late HSN differentiation. In an unc-86; ham-2 double mutant the HSNs are defective in EGL-43 down-regulation, an egl-5-like phenotype that is absent in either single mutant. Thus, in the HSN, a Hox gene, egl-5, regulates cell fate by activating the transcription of genes encoding the transcription factors HAM-2 and UNC-86 that in turn individually control some differentiation events and combinatorially affect others.
Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/genética , Movimiento Celular/genética , Genes Homeobox/genética , Proteínas del Helminto/genética , Neuronas Motoras/metabolismo , Factores de Transcripción/genética , Dedos de Zinc/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Caenorhabditis elegans/embriología , Diferenciación Celular/genética , Clonación Molecular , Regulación del Desarrollo de la Expresión Génica/genética , Proteínas del Helminto/química , Proteínas de Homeodominio/genética , Microscopía Fluorescente , Datos de Secuencia Molecular , Mutación/genética , Factores del Dominio POU , Fenotipo , Análisis de Secuencia de ADN , Factores de Transcripción/químicaRESUMEN
Computer-based sun safety instruction has many advantages that may be attractive to health educators in schools. An educational multimedia computer program on sun safety was produced on CD-ROM for children in grades 4 and 5, which was based on the "Sunny Days, Healthy Ways" sun safety curriculum (SDHW). Its effects on children's sun safety knowledge, attitudes and behaviour were evaluated with 162 students in 8 fourth and fifth grade classes in a randomized pretest-posttest 2 x 2 factorial design. Children interacting with the CD-ROM program showed significant improvements in knowledge (p = 0.007). The effect on knowledge may have indirectly improved children's sun protection (r = 0.201, p = 0.013), even though the CD-ROM program did not directly increase sun protection (p > .05) or improve attitudes (p > .05). The CD-ROM program may be a cost-effective and administratively acceptable sun safety instructional strategy, however, like many short prevention strategies, it will be most successful at conveying information on sun safety to children.