Acoustic performance of near-rail low-height noise barriers installed on suburban railway bridges.

With the large-scale construction of suburban railway viaducts, the noise problem along the viaducts is becoming more and more prominent. Conventional vertical noise barriers have been widely used to alleviate the noise problem along the suburban railway viaducts. However, conventional vertical noise barriers often have an adverse effect on the urban landscape and also block the view of train drivers and passengers. A type of near-rail low-height noise barrier was planned to install on the viaducts of Wenzhou Rail Transit Line S1 to reduce the impact of noise on residents along the railway lines. To assess the acoustic performance of the near-rail low-height noise barrier, a numerical procedure for railway viaduct comprehensive noise considering wheel-rail noise and structure-borne noise of the bridge and noise barriers was proposed and then verified by a field test. On this basis, numerical models were established to compare the acoustic performances of the near-rail low-height noise barrier and conventional vertical noise barrier. The influences of the height and top shape of the near-rail low-height noise barrier on the acoustic performance were discussed. Based on the numerical analysis results, it is found that both the near-rail low-height noise barrier and conventional vertical noise barrier have good acoustic performances. The noise reduction effect of the near-rail low-height noise barrier is slightly better than that of the conventional vertical noise barrier. The acoustic performance of the near-rail low-height noise barrier gradually improves, but the improvement rate gradually slows down as the height of the noise barrier increases. The noise reduction effects of both the inverted L-shaped and Y-shaped near-rail low-height noise barrier are obviously better than that of the vertical one, while the noise reduction effects of the inverted L-shaped near-rail low-height noise barrier are slightly better than the Y-shaped one.

Development and validation of a physical model to investigate the biomechanics of infant head impact.

Head injury in childhood is the single most common cause of death or permanent disability from injury. However, despite its frequency and significance, there is little understanding of the response of a child's head to injurious loading. This is a significant limitation when making early diagnoses, informing clinical and/or forensic management or injury prevention strategies. With respect to impact vulnerability, current understanding is predominantly based on a few post-mortem-human-surrogate (PMHS) experiments. Researchers, out of experimental necessity, typically derive acceleration data, currently an established measure for head impact vulnerability, by calculation. Impact force is divided by the head mass, to produce a "global approximation", a single-generalised head response acceleration value. A need exists for a new experimental methodology, which can provide specific regional or localised response data. A surrogate infant head, was created from high resolution computer tomography scans with properties closely matched to tissue response data and validated against PMHS head impact acceleration data. The skull was 3D-printed from co-polymer materials. The brain, represented as a lumped mass, comprised of an injected gelatin/water mix. High-Speed Digital-Image-Correlation optically measured linear and angular velocities and accelerations, strains and strain rates. The "global approximation" was challenged by comparison with regional and local acceleration data. During impacts, perpendicular (at 90°) to a surface, regional and local accelerations were up to three times greater than the concomitant "global" accelerations. Differential acceleration patterns were very sensitive to impact location. Suture and fontanelle regions demonstrated ten times more strain (103%/s) than bone, resulting in skull deformations similar in magnitude to those observed during child birth, but at much higher rates. Surprisingly, perpendicular impacts produced significantly greater rotational velocities and accelerations, which are closer to current published injury thresholds than expected, seemingly as a result of deformational changes to the complex skull geometry. The methodology has proven a significant new step in characterising and understanding infant head injury mechanics.

Síndrome Kenny-Caffey en varios miembros de una familia / Kenny-Caffey Syndrome in several members of a family

El síndrome Kenny-Caffey es una enfermedad hereditaria, extremadamente rara, que se transmite de forma autosómica dominante y se caracteriza por retraso del crecimiento, anomalías oculares, hipocalcemia y engrosamiento cortinal de los huesos largos, cuyo diagnóstico precoz e intervención temprana ayudarán a mejorar la calidad de vida de los afectados. Se presenta a 2 miembros de una familia (la madre y un hijo), atendidos en la consulta de genética clínica de la provincia de Holguín, con características clínicas que se correspondían con dicho síndrome, para compartir estos hallazgos con la comunidad médica en general, pues llamó la atención que estuvieran afectados 3 personas de una misma familia, aunque solo se describe a 2 de ellos

The Kenny-Caffey syndrome is a hereditary, extremely strange disease that is transmitted in an autosomal dominant way and is characterized by growth failure, ocular anomalies, hypocalcemia and cortinal swelling of the long bones whose early diagnosis and intervention will help to improve the life quality of affected patients. Two members of a family are presented (mother and a son), assisted in the clinical genetics service in Holguín, with clinical characteristics that fitted with this syndrome, to share these findings with the medical community in general, because the fact that 3 people of the same family were affected attracted attention, although just 2 of them are described

Síndrome de Aarskog: hallazgos fenotípicos en una cohorte de pacientes / Aarskog syndrome: phenotypic findings in a cohort of patients

Se presentan los hallazgos fenotípicos de 7 pacientes diagnosticados de síndrome de Aarskog en el servicio de Genética del Hospital Pediátrico Docente William Soler. Las características fenotípicas que estuvieron presentes en todos los pacientes fueron el pico de viuda, las extremidades cortas y la braquidactilia. Les siguieron en orden de frecuencia (85 por ciento) la nariz pequeÑa, el puente nasal ancho y el filtrum largo y ancho. Otras dismorfias faciales encontradas (71 por ciento) fueron la frente amplia, las narinas antevertidas, el hipertelorismo, el cuello corto y el surco simiano. Se discute la posibilidad de que exista algún sesgo de detección debido a que el examinador presta mayor atención a la cara que a otros segmentos corporales. La criptorquidia, que distingue y da nombre al síndrome, se encontró en un porcentaje menor de individuos (60 por ciento). En dos casos se encontró hipoplasia renal, hallazgo ocasional en la literatura consultada. En ningún caso se constató retraso mental. Las diferencias fenotípicas halladas pudieran atribuirse a las diferencias moleculares reportadas en la literatura.

The phenotypic fndings of 7 patients who were diagnosed Aarskog syndrome in the Service of Genetics of William Soler Pediatric Teaching Hospital were presented. The phenotypic characteristics appearing in all patients were widow's peak, short extremities and brachydactilia. They were followed in order of frequency (85 percent) by small nose, wide nasal bridge and long and wide filtrum. Other facial dismorphies (71 percent) were wide forehead, anteverted narines, hypertelorism, short neck and simian crease. It is discussed the possibility that there is some bias of detection due to the fact that the examiner pays more attention to the face than to other body segments. Criptorchydia, that distinguishes and gives name to the syndrome, was found in a lower percent of individuals (60 percent). Renal hypoplasia, an occasional finding in the consulted literature, was observed in 2 cases. Mental retardation was not confirmed in any case. The phenoptypic differences detected could be attributed to mollecular differences reported in literature.