The scattering and reflection of SH waves by a slope on an elastic wedged space is investigated. A series solution is obtained by using the wave function expansion method. The slope on a wedged space is divided into t...The scattering and reflection of SH waves by a slope on an elastic wedged space is investigated. A series solution is obtained by using the wave function expansion method. The slope on a wedged space is divided into two subregions by an artificial, auxiliary circular arc. The wave fields with unknown complex coefficients within each sub-region are derived. Applying Graf addition theorem, the scattered waves in the sub-regions are expressed in a global coordinate system. Fourier transform is adopted to derive a consistent form of standing waves in the inner region using the orthogonality of the cosine functions. The boundary-valued problem is solved by stress and displacement continuity along the artificial, auxiliary arc to obtain the unknown complex coefficients. Parametric studies are next performed to investigate how the topography from the slope on the wedged space will affect the scattering and diffraction, and hence the amplification and de-amplification of the SH waves. Numerical results show that the surface motions on the slope of the wedged space is influenced greatly by the topography. Amplification of the surface motions near the slope vertex is significant. The corresponding phases along the wedged space surfaces are consistent with the direction that the SH waves are propagating.展开更多
Background/Aim: The present study was directed to investigate the accuracy of ultrasound (USG) in early detection of developmental dysplasia of the hip (DDH) to prevent permanent complications. Material & Methods:...Background/Aim: The present study was directed to investigate the accuracy of ultrasound (USG) in early detection of developmental dysplasia of the hip (DDH) to prevent permanent complications. Material & Methods: A total of 276 infants was investigated;their ages range from 1 - 6 months. Patients referred from the clinic based on clinical assessment (mainly Barlo & Ortolani maneuvers). Then the patient’s hips were examined by expert radiologists in USG scan. After that, dynamic (coronal and transverse) & static ultrasound views evaluated by the same radiologist using Graf’s criteria. Infants with abnormal ultrasound findings suggestive of DDH were followed up after 4 - 6 weeks by the same investigator to monitor the progress. At the same time, the patient referred to a specialist for conservative management from the first positive findings. Results: Among the 276 referred patients, infants with normal stable hips (Graf Type I and Type II a+) were 221 (80%), 155 of them were female and 66 male infants. Infants with unstable hips based on Graf’s criteria (Type II a-, II b, II c and Type III a) were 55 (20%). Out of 55 with abnormal findings, the affected hips on both sides, right and left were: 5 cases (1.8%), 7 (2.5%) and 43 hips (15.5%) consecutively. Out of 55 infants affected;3 referred to tertiary centers for further surgical management while 52 managed conservatively. Conclusion: Delayed treatment rates of DDH and complications could be reduced by the usage of the USG after the first month of life. In addition to physical assessment, USG for high-risk infants will provide more accurate diagnosis and minimize complications.展开更多
Optimal DDH screening timing and whether adding risk profiles could aid in detecting treatment outcome were investigated. Risk factors were employed to supplement ultrasound findings in flagging cases for follow-up. I...Optimal DDH screening timing and whether adding risk profiles could aid in detecting treatment outcome were investigated. Risk factors were employed to supplement ultrasound findings in flagging cases for follow-up. Initial screening results and harness treatment outcomes concordance were compared at different screening ages and screening protocols. Using clinical decision to supplement ultrasound screening allowed to accurately flag all 12 DDH treated cases upon initial visit. Clinical decision correctly identified cases that would have otherwise been missed (n = 2). However, doing so increased the rate of false positive cases at all time points of initial screening. Initial screens were more accurate for predicting treatment outcomes when using ultrasound only if done after 28 days [≤28 days (88.1%) vs. 29 - 56 days (98.5%), OR = 7.16, p < 0.001] or ultrasound with clinical decision [≤28 days (86.4%) vs. 29 - 56 days (95.7%), OR = 3.00, p < 0.001]. In contrast, screening after 56 days failed to marginally improve accuracy compared to screens done between 29 - 56 days, regardless of the screening protocol employed. Two important trade-offs emerged. First, when choosing timing of initial screening, optimal accuracy and harness treatment schedule should both be considered. Second, when considering whether to use a more conservative risk profile to supplement ultrasound findings, treatment accuracy and the ability to efficiently detect cases requiring harness treatment should both be considered. We provide evidence for performing an initial DDH ultrasound screen between 4 and 8 weeks (29 - 56 days), while employing clinical decision to aid in determining cases that require further follow-up evaluation.展开更多
Developmental Dysplasia of the Hip (DDH) describes a wide range of anatomic abnormalities of the growing hips which might result in permanent abnormal gait. Therefore, early detection and management is crucial to impr...Developmental Dysplasia of the Hip (DDH) describes a wide range of anatomic abnormalities of the growing hips which might result in permanent abnormal gait. Therefore, early detection and management is crucial to improve the outcome and minimise the risk of osteoarthritis in later life. Hip ultrasound is used to evaluate DDH based on Graf classification. Graf score is a widely used ultrasound grading score to evaluate DDH in infants. There is conflicting evidence regarding the management of the developmentally immature Graf type IIa hip. Some physicians adopt watchful waiting for natural maturation of hips while other early treatment. This article will provide an evidence-based review on the management modalities of the Graf type IIa hip.展开更多
The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been stud...The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been studied in the presence of air. To establish reaction conditions for the graft modification of NNMBAA onto silk, the effect of different variables such as the initiator concentration, monomer concentration, acetic acid concentration, time of polymerization, reaction temperature and liquor ratio (fabric: liq.) have been studied. The optimum grafting conditions were found. As evidence of grafting, analyses of amino acid composition and alkali solubility have been carried out. Grafting caused changes in amino acid composition and alkali solubility of silk. The observation has been explained in relation to structural changes in the grafted silk.展开更多
Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing.Beijing Graffiti is a recent book co-authored...Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing.Beijing Graffiti is a recent book co-authored by Dartnell along with Beijing photographer Liu Yuansheng,also known as'Liu Laoshi/The book features Liu's photographs of graffiti works by various artists around the capital city.The images are accompanied by interviews in which each artist gives their thoughts on Beijing's graffiti scene.展开更多
Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing・Beijing Graffiti is a recent book co-authored...Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing・Beijing Graffiti is a recent book co-authored by Dartnell along with Beijing photographer Liu Yuansheng,also known as'Liu Laoshi/The book features Liu's photographs of graffiti works by various artists around the capital city.The images are accompanied by interviews in which each artist gives their thoughts on Beijing's graffiti scene.展开更多
AIM:To determine the influence of gaps[places where neither the donor's nor the recipient's Descemet's membrane(DM)is present]and overlaps(places where the recipient's DM is covered by the donor's ...AIM:To determine the influence of gaps[places where neither the donor's nor the recipient's Descemet's membrane(DM)is present]and overlaps(places where the recipient's DM is covered by the donor's DM)on the frequency of postoperative detachment of DM endothelial keratoplasty(DMEK)lamellae.METHODS:Totally 64 eyes of 64 patients with Fuchs'endothelial dystrophy or bullous keratopathy indicated for DMEK were randomly divided in two groups.The diameter of the implanted DMEK lamella was the same in both groups(8 mm),but we changed the diameter of the removed recipient DM.In the first group(32 eyes),the circular area was approximately 8.5 mm(gaps);in the second group(32 eyes),the diameter was 7.5 mm(overlaps).Postoperatively we noted all cases of detachment visible on the slit lamp and these cases we indicated for rebubbling.We also measured the uncorrected distance visual acuity(UDVA)as well as corrected distance visual acuity(CDVA)in decimal and postoperative endothelial cell density(ECD).The minimum follow-up time was 6mo.RESULTS:The number of rebubbling procedures in the entire group of patients was 13,i.e.,20.3%,with 6 eyes(18.7%)in the gap group,and 7 eyes(21.9%)in the overlap group.Lamella replacement(re-DMEK)was required in 3(gap group)and 2 patients(overlap group),respectively.The dif ference between the groups was statistically insignificant.The UDVA was 0.54±0.21 in the gap group and 0.58±0.24 in the overlap group.The CDVA was 0.74±0.22 and 0.80±0.16,respectively.ECD was 1920±491 and 2149±570 cells/mm2.The small differences between both groups were not statistically significant.CONCLUSION:We do not notice any difference in the group of patients with overlaps or gaps of DM.The presence of small areas of gaps or overlaps does not affect the frequency of detachment of the DMEK lamellae.展开更多
文摘The scattering and reflection of SH waves by a slope on an elastic wedged space is investigated. A series solution is obtained by using the wave function expansion method. The slope on a wedged space is divided into two subregions by an artificial, auxiliary circular arc. The wave fields with unknown complex coefficients within each sub-region are derived. Applying Graf addition theorem, the scattered waves in the sub-regions are expressed in a global coordinate system. Fourier transform is adopted to derive a consistent form of standing waves in the inner region using the orthogonality of the cosine functions. The boundary-valued problem is solved by stress and displacement continuity along the artificial, auxiliary arc to obtain the unknown complex coefficients. Parametric studies are next performed to investigate how the topography from the slope on the wedged space will affect the scattering and diffraction, and hence the amplification and de-amplification of the SH waves. Numerical results show that the surface motions on the slope of the wedged space is influenced greatly by the topography. Amplification of the surface motions near the slope vertex is significant. The corresponding phases along the wedged space surfaces are consistent with the direction that the SH waves are propagating.
文摘Background/Aim: The present study was directed to investigate the accuracy of ultrasound (USG) in early detection of developmental dysplasia of the hip (DDH) to prevent permanent complications. Material & Methods: A total of 276 infants was investigated;their ages range from 1 - 6 months. Patients referred from the clinic based on clinical assessment (mainly Barlo & Ortolani maneuvers). Then the patient’s hips were examined by expert radiologists in USG scan. After that, dynamic (coronal and transverse) & static ultrasound views evaluated by the same radiologist using Graf’s criteria. Infants with abnormal ultrasound findings suggestive of DDH were followed up after 4 - 6 weeks by the same investigator to monitor the progress. At the same time, the patient referred to a specialist for conservative management from the first positive findings. Results: Among the 276 referred patients, infants with normal stable hips (Graf Type I and Type II a+) were 221 (80%), 155 of them were female and 66 male infants. Infants with unstable hips based on Graf’s criteria (Type II a-, II b, II c and Type III a) were 55 (20%). Out of 55 with abnormal findings, the affected hips on both sides, right and left were: 5 cases (1.8%), 7 (2.5%) and 43 hips (15.5%) consecutively. Out of 55 infants affected;3 referred to tertiary centers for further surgical management while 52 managed conservatively. Conclusion: Delayed treatment rates of DDH and complications could be reduced by the usage of the USG after the first month of life. In addition to physical assessment, USG for high-risk infants will provide more accurate diagnosis and minimize complications.
文摘Optimal DDH screening timing and whether adding risk profiles could aid in detecting treatment outcome were investigated. Risk factors were employed to supplement ultrasound findings in flagging cases for follow-up. Initial screening results and harness treatment outcomes concordance were compared at different screening ages and screening protocols. Using clinical decision to supplement ultrasound screening allowed to accurately flag all 12 DDH treated cases upon initial visit. Clinical decision correctly identified cases that would have otherwise been missed (n = 2). However, doing so increased the rate of false positive cases at all time points of initial screening. Initial screens were more accurate for predicting treatment outcomes when using ultrasound only if done after 28 days [≤28 days (88.1%) vs. 29 - 56 days (98.5%), OR = 7.16, p < 0.001] or ultrasound with clinical decision [≤28 days (86.4%) vs. 29 - 56 days (95.7%), OR = 3.00, p < 0.001]. In contrast, screening after 56 days failed to marginally improve accuracy compared to screens done between 29 - 56 days, regardless of the screening protocol employed. Two important trade-offs emerged. First, when choosing timing of initial screening, optimal accuracy and harness treatment schedule should both be considered. Second, when considering whether to use a more conservative risk profile to supplement ultrasound findings, treatment accuracy and the ability to efficiently detect cases requiring harness treatment should both be considered. We provide evidence for performing an initial DDH ultrasound screen between 4 and 8 weeks (29 - 56 days), while employing clinical decision to aid in determining cases that require further follow-up evaluation.
文摘Developmental Dysplasia of the Hip (DDH) describes a wide range of anatomic abnormalities of the growing hips which might result in permanent abnormal gait. Therefore, early detection and management is crucial to improve the outcome and minimise the risk of osteoarthritis in later life. Hip ultrasound is used to evaluate DDH based on Graf classification. Graf score is a widely used ultrasound grading score to evaluate DDH in infants. There is conflicting evidence regarding the management of the developmentally immature Graf type IIa hip. Some physicians adopt watchful waiting for natural maturation of hips while other early treatment. This article will provide an evidence-based review on the management modalities of the Graf type IIa hip.
文摘The graft modification of N, N'-methylene-bisacrylamide (NNMBAA) onto silk using eerie ammonium sulfate, potassium persulfate, ammonium persulfate and 2, 2-azobis (isobutyronitrile) as the initiators has been studied in the presence of air. To establish reaction conditions for the graft modification of NNMBAA onto silk, the effect of different variables such as the initiator concentration, monomer concentration, acetic acid concentration, time of polymerization, reaction temperature and liquor ratio (fabric: liq.) have been studied. The optimum grafting conditions were found. As evidence of grafting, analyses of amino acid composition and alkali solubility have been carried out. Grafting caused changes in amino acid composition and alkali solubility of silk. The observation has been explained in relation to structural changes in the grafted silk.
文摘Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing.Beijing Graffiti is a recent book co-authored by Dartnell along with Beijing photographer Liu Yuansheng,also known as'Liu Laoshi/The book features Liu's photographs of graffiti works by various artists around the capital city.The images are accompanied by interviews in which each artist gives their thoughts on Beijing's graffiti scene.
文摘Shanghai-based author Tom Dartnell has been documenti ng graffiti since 1988.In recent years,his attention has turned to the small but intriguing graffiti scene in Beijing・Beijing Graffiti is a recent book co-authored by Dartnell along with Beijing photographer Liu Yuansheng,also known as'Liu Laoshi/The book features Liu's photographs of graffiti works by various artists around the capital city.The images are accompanied by interviews in which each artist gives their thoughts on Beijing's graffiti scene.
文摘AIM:To determine the influence of gaps[places where neither the donor's nor the recipient's Descemet's membrane(DM)is present]and overlaps(places where the recipient's DM is covered by the donor's DM)on the frequency of postoperative detachment of DM endothelial keratoplasty(DMEK)lamellae.METHODS:Totally 64 eyes of 64 patients with Fuchs'endothelial dystrophy or bullous keratopathy indicated for DMEK were randomly divided in two groups.The diameter of the implanted DMEK lamella was the same in both groups(8 mm),but we changed the diameter of the removed recipient DM.In the first group(32 eyes),the circular area was approximately 8.5 mm(gaps);in the second group(32 eyes),the diameter was 7.5 mm(overlaps).Postoperatively we noted all cases of detachment visible on the slit lamp and these cases we indicated for rebubbling.We also measured the uncorrected distance visual acuity(UDVA)as well as corrected distance visual acuity(CDVA)in decimal and postoperative endothelial cell density(ECD).The minimum follow-up time was 6mo.RESULTS:The number of rebubbling procedures in the entire group of patients was 13,i.e.,20.3%,with 6 eyes(18.7%)in the gap group,and 7 eyes(21.9%)in the overlap group.Lamella replacement(re-DMEK)was required in 3(gap group)and 2 patients(overlap group),respectively.The dif ference between the groups was statistically insignificant.The UDVA was 0.54±0.21 in the gap group and 0.58±0.24 in the overlap group.The CDVA was 0.74±0.22 and 0.80±0.16,respectively.ECD was 1920±491 and 2149±570 cells/mm2.The small differences between both groups were not statistically significant.CONCLUSION:We do not notice any difference in the group of patients with overlaps or gaps of DM.The presence of small areas of gaps or overlaps does not affect the frequency of detachment of the DMEK lamellae.
