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To investigate age-related changes on passive muscle stiffness in healthy individuals and measure the shear modulus in different age groups. Shear wave elastography (SWE) movies of gastrocnemius medialis (GM) were collected during passive stretching induced by ankle rotation from plantarflexion (PF) to dorsiflexion (DF). A series of SWE images at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, 0°, DF 10°, DF 20°, and DF 30° were collected and shear moduli measured accordingly for analyses. Eighty-six healthy volunteers (27 children, 31 middle-aged adults, and 28 older people) were recruited. No significant difference was observed in the shear modulus between the three groups at ankle angles of PF 40°, PF 30°, PF 20°, PF 10°, and 0° (p > 0.05). The difference in the shear modulus among the three groups became significant as DF increased. At ankle angles of DF 10°, DF 20°, and DF 30°, the shear modulus was the greatest in the older group, followed by the middle-aged group and then the children group (p = 0.007, 0.000, and 0.000, respectively). Passive muscle stiffness increases with age, and the difference between age groups was pronounced only after reaching a certain degree of stretching. • The influence of age on passive muscle stiffness becomes pronounced only after reaching a certain degree of stretching. • Age should be considered when evaluating passive muscle stiffness in muscular disorders.

Aim: To investigate the reliability of quantitative analysis of dynamic stretching muscle stiffness using shear wave elas- tography (SWE), and to evaluate the influence of stretched levels and region of interest (ROI) sizes on the repeatability of SWE measurements. Materials and methods: SWE videos of the gastrocnemius medius were collected during ankle movement from plantar flexion (PF) 40° to dorsiflexion (DF) 30°. Shear wave images were collected of ankle angles at PF 25°, 0°, DF 15°, and DF 30°, representing the slack status, mildly stretched level, moderately stretched level, and maximal stretched level of the gastrocnemius medius, respectively. ROI circles with diameters of 2 mm, 5 mm, and 8 mm were applied to measure the shear modulus. Intra-observer, and inter-observer repeatability of the measurements were compared among different stretched levels and ROI sizes. Results: Twenty-one healthy volunteers were enrolled. Muscle stiffness increased as the ankle DF increased. Intraclass correlation coefficients (ICCs) of intra-observer and inter-observer repeatability obtained for ROI sizes of 2 mm, 5 mm and 8 mm indicated good to excellent repeatability at all stretched levels. Conclusions: Shear wave elastography appeared to be a reliable tool to evaluate the dynamic stretching muscle stiffness with satisfactory repeatability at various stretched levels of gastrocnemius medius. Good to excellent repeatability was found using different ROI sizes.

Background A reliable anterior facial vein (AFV, donor vein) is cardinal for the success of submandibular gland (SMG) transplantation. This study determined the impact of computed tomographic (CT) venography in identifying AFV variations for SMG transplantation. Methods CT venography was performed in consecutive patients with severe dry eye prior to SMG transplantation in order to identify disadvantageous AFV variations for vascular anastomosis, namely, AFVs that did not drain the SMG and those that did not match the superficial temporal vein (STV, recipient vein; AFV:STV caliber ratio, ≥3). The CT results were compared with the intraoperative findings for the diagnostic accuracy. Results Forty-two donors were included. Compared with the intraoperative findings, the CT results accurately identified AFV–STV caliber mismatches ( P = 1.00; sensitivity and specificity, 100%). In the identification of AFVs not draining the SMG, CT showed 94.7% sensitivity and 100% specificity ( P = 0.25). According to the CT findings, 10 contralateral SMGs with AFVs (23.8%), instead of ipsilateral donors, were selected for transplantations (conventionally ipsilateral donor was the first choice). The surgical success rate was 95.2% (40/42). Conclusion CT venography is valuable in determining disadvantageous AFV variations for anastomosis and choosing a reliable donor for SMG transplantation.

Aims This study sought to explore right (RV) and left ventricular (LV) mechanics and ventricular–ventricular interaction in adolescents and young adults late after percutaneous balloon pulmonary valvoplasty (PBPV) for valvar pulmonary stenosis (PS). Methods and results Potential late effects of PS despite PBPV on cardiac mechanics have not been well defined. Thirty-one patients aged 20.2 ± 7.6 years were studied at 18 ± 6 years after PBPV. Ventricular myocardial deformation was determined using speckle tracking echocardiography, while RV and LV volumes and ejection fraction as well as LV systolic dyssynchrony index were assessed by three-dimensional echocardiography. The results were compared with those of 30 controls. Pulmonary regurgitation, mostly trivial to mild, was present in 90% (28/31) of patients. Compared with controls, patients had significantly greater RV end-diastolic ( P < 0.001), RV end-systolic ( P < 0.001), and LV end-systolic ( P = 0.04) volumes as well as lower LV ejection fraction ( P < 0.001). For deformation, patients had significantly reduced RV longitudinal systolic strain ( P = 0.004), decreased LV circumferential systolic strain ( P < 0.001), and strain rate ( P = 0.001) as well as greater LV mechanical dyssynchrony ( P < 0.001). In patients, RV end-diastolic and end-systolic volumes correlated with LV circumferential strain ( r = −0.47, P = 0.008 and r = −0.36, P = 0.049, respectively) and dyssynchrony ( r = 0.53, P = 0.002 and r = 0.49, P = 0.005, respectively). Patients who had PBPV at age ≤1 year had ventricular deformation indices similar to those who had interventions beyond 1 year. Conclusion Impaired RV and LV mechanics and adverse ventricular–ventricular interaction occur in adolescents and young adults late after balloon valvoplasty for isolated valvar PS.

Background: The aim of this case-control study was to assess the usefulness of three-dimensional (3D) speckle-tracking echocardiography in the evaluation of global left ventricular (LV) myocardial performance in adolescent and adult survivors of childhood cancers. Methods:Fifty-threeanthracycline-treated survivorsofchildhoodcancers(meanage,18.665.1years)and38 controls were studied. Three-dimensional speckle-tracking echocardiography was performed to assess LV 3D global and segmental strain, time to peak segmental 3D strain, LV torsion, and ejection fraction. LV systolic dyssynchrony index (SDI) was calculated as the percentage of the standard deviation of times to peak strain of the 16 segments divided by the RR interval. A global performance index (GPI) was calculated as (global 3D strain torsion)/SDI. The area under the receiver operating characteristic curve was calculated to determine the capability of various echocardiographic indices to discriminate between patients and controls. Results: Compared with controls, patients had significantly reduced LV global 3D strain (P < .001), torsion (P < .001), and GPI (P < .001) and greater SDI (P < .001). All except the basal anteroseptal segment in patients had reduced regional 3D strain compared with controls (P < .05 for all). Global 3D strain (P = .018), SDI (P = .003), and GPI (P = .02) were correlated with cumulative anthracycline dose. The areas under the curves for GPI, global 3D strain, 1/SDI, torsion, and ejection fraction were 0.92, 0.79, 0.79, 0.79, and 0.78, respectively. A GPI cutoff of 10.6/cm had sensitivity of 84.9% and specificity of 81.6% of differentiating patients from controls. Conclusions: Three-dimensional speckle-tracking echocardiography enables the derivation of an index of LV global performance that incorporates LV 3D strain, dyssynchrony, and torsion for the sensitive detection of altered LV mechanics in childhood cancer survivors. (J Am Soc Echocardiogr 2013;26:846-52.)

Background Ventricular diastolic dysfunction in patients with repaired tetralogy of Fallot (TOF) may affect atrial mechanics. This study aimed to explore right atrial (RA) and left atrial (LA) mechanics in repaired TOF patients and their relationship with ventricular diastolic function. Methods Fifty-four patients (36 males), aged 17.8 ± 8.3 years, who had undergone TOF repair at 3.9 ± 3.3 years and 40 healthy subjects aged 16.9 ± 6.3 years (P = 0.57) were studied. Right and LA peak positive, peak negative, and total strain, strain rate at ventricular systole (SRs), early diastole (SRed), and atrial contraction (SRac), and electromechanical delay were determined using speckle tracking echocardiography (STE). Ventricular diastolic function was assessed by tissue Doppler imaging and STE. Ventricular volumes and pulmonary regurgitant volume were derived from 3D echocardiography. Results Compared with controls, patients had significantly lower RA and LA peak positive and total strain, SRs, SRed, and SRac (all P

Background The clinical relevance of evaluating right ventricular (RV) myocardial deformation in congenital heart disease is increasingly recognized. The aim of this study was to explore, using three-dimensional (3D) speckle-tracking echocardiography, RV mechanics in terms of 3D global area strain and mechanical dyssynchrony in adults with repaired tetralogy of Fallot. Methods Twenty patients (12 men) aged 24.7 ± 8.6 years and 22 age-matched controls (11 men) were studied. Global RV peak area strain and area strain–derived systolic dyssynchrony index (SDI) were determined using 3D speckle-tracking echocardiography. RV end-diastolic volume and end-systolic volume, ejection fraction (EF), and pulmonary regurgitation fraction were measured in patients using cardiac magnetic resonance. Results Coefficients of variation for intraobserver and interobserver measurements of RV global area strain were 6.1% and 7.9%, respectively, and those for SDI were 7.6% and 10.1%, respectively. Compared with controls, patients had significantly lower global area strain ( P = .005) and greater SDI ( P = .008). The prevalence of RV mechanical dyssynchrony (SDI > control mean + 2 SDs) in patients was 30%. In patients, global area strain correlated inversely with SDI ( r = −0.42, P = .04), RV end-diastolic volume ( r = −0.48, P = .032), and RV end-systolic volume ( r = −0.48, P = .031) and positively with EF ( r = −0.51, P = .02), while RV SDI correlated positively with RV end-systolic volume ( r = 0.55, P = .012), pulmonary regurgitation fraction ( r = 0.54, P = .031), and QRS duration ( r = 0.51, P = .022) and negatively with RV EF ( r = −0.62, P = .004). Multivariate analysis showed that RV EF (β = 0.22, P = .048) was a significant correlate of global area strain in patients. Conclusions In adults after tetralogy of Fallot repair, 3D RV deformation is impaired in association with RV dyssynchrony, volume overloading, and reduced EF.

The paper discusses two policies for recognizing NEs with complex structures by maximum entropy models. One policy is to develop cascaded MaxEnt models at different levels. The other is to design more detailed tags with human knowledge in order to represent complex structures. The experiments on Chinese organization names recognition indicate that layered structures result in more accurate models while extended tags can not lead to positive results as expected. We empirically prove that the {start, continue, end, unique, other} tag set is the best tag set for NE recognition with MaxEnt models.

This paper presents a unified approach for Chinese lexical analysis using hierarchical hidden Markov model (HHMM), which aims to incorporate Chinese word segmentation, Part-Of-Speech tagging, disambiguation and unknown words recognition into a whole theoretical frame. A class-based HMM is applied in word segmentation, and in this level unknown words are treated in the same way as common words listed in the lexicon. Unknown words are recognized with reliability in role-based HMM. As for disambiguation, the authors bring forth an n-shortest-path strategy that, in the early stage, reserves top N segmentation results as candidates and covers more ambiguity. Various experiments show that each level in HHMM contributes to lexical analysis. An HHMM-based system ICTCLAS was accomplished. The recent official evaluation indicates that ICTCLAS is one of the best Chinese lexical analyzers. In a word, HHMM is effective to Chinese lexical analysis.

Cardiovascular disorders are important causes of late morbidity in childhood cancer survivors. This study assessed the usefulness of three-dimensional speckle tracking echocardiography (3D-STE) in the evaluation of global left ventricular (LV) myocardial performance in adolescent and adult survivors