Quantitative Assessment of Skin Stiffness Using Ultrasound Shear Wave Elastography in Systemic Sclerosis

This study was aimed at investigating the performance of ultrasound shear wave elastography (US-SWE) in the assessment of skin (the dermis) stiffness in patients with systemic sclerosis (SSc). The thickness and elastic modulus of the skin were measured using US-SWE at 6 sites in 60 SSc patients and 60 healthy volunteers: the bilateral middle fingers and forearms and the anterior chest and abdomen. To evaluate clinical scores, the measurements were also extended to 17 skin sites in 30 patients. The diagnostic performance of US-SWE in the differentiation of SSc from healthy skin was determined by receiver operating characteristic (ROC) curve analysis, and the reliability of the measurement was evaluated with intra- and inter-class correlation coefficients. The results of US-SWE were compared with modified Rodnan skin thickness scores. Our results indicated that (i) the elastic modulus values were significantly higher in SSc patients than in controls, with or without normalization by skin thickness; (ii) receiver operating characteristic analysis revealed normalized US-SWE cutoff values with a very high accuracy for right and left fingers (areas under the curve?=?0.974 and 0.949), followed by left forearm (0.841), anterior abdomen (0.797), right forearm (0.772) and anterior chest (0.726); (iii) the reliability of US-SWE measurements was good for all examined sites with intra-observer correlation coefficients of 0.845–0.996 and inter-observer correlation coefficients of 0.824–0.985; and (iv) total scores of skin involvement determined at 17 sites (modified Rodnan skin thickness scores) correlated with skin stiffness (r?=?0.832) and thickness (r?=?0.736). In conclusion, US-SWE is a quantitative method with high specificity, sensitivity and reliability in the detection of SSc involvement. This non-invasive, real-time and operator-independent imaging technique could be an ideal tool for the assessment of SSc disease.     

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??Objective??The new type of zirconia materials and dentin was bonded with different adhesive systems??using different types of LED curing lights. By comparing the shear strength??to provide certain theoretical reference for the choice of clinical indications??adhesives systems and curing lights of the new type of restoration. Methods??According to the unified standard??maxillary incisors in vitro were selected as experimental samples. Prepared and scanned post space??new type of zirconia post was made by CAD/CAM. Randomly divided into 6 groups??post was respectively bonded using 3 kinds of adhesive systems ??Panavia F??Multilink N??NX3-Nexus?? and 2 kinds of LED lights ??ordinary ??VALO??. Then the samples were horizontally cut into a 1 mm slice. The slices were released in the universal mechanical test machine??the shear strength of each group was analyzed by SPSS 17.0. Results????The shear strength of Panavia F was better than that of Multilink N and NX3-Nexus??using the ordinary LED curing light ??P < 0.05??. Panavia F also had higher shear strength than the other two adhesive systems, using VALO LED curing light ??P < 0.05??. There was no significant difference in shear strength between the ordinary and VALO light??using the same adhesive systems ??P > 0.05??. Conclusion????The adhesion strength of Panavia F is better than those of Multilink N and NX3-Nexus??using different types of LED curing lights. There is no significant difference in adhesion strength between VALO and ordinary LED curing light??the VALO LED curing light can significantly reduced the operating time by the side of the chair.     

Correlation between Classical Rheometry and Supersonic Shear Wave Imaging in Blood Clots

The assessment of coagulating blood elasticity has gained importance as a result of several studies that have correlated it to cardiovascular pathologic conditions. In this study we use supersonic shear wave imaging (SSI) to measure viscoelastic properties of blood clots. At the same time, classical rheometry experiments were carried out on the same blood samples taken within the first few seconds of coagulation. Using SSI, phase velocities of the shear wave indicated increasing dispersion with time. In all cases, the frequency bandwidth of propagating shear waves changed from 20–50 Hz at the first few min of coagulation to around 300 Hz toward the end of experiments. Using the values of G′ and G″ from the rheometry studies, the theoretical shear wave velocities were calculated and correlated with SSI measurements. Results of the two techniques were in very good agreement, confirming that SSI provides accurate measurements of viscoelastic properties as corroborated by conventional rheometric measurements.     

孙丽平教授治疗小儿唇风经验

孙丽平教授认为,小儿唇风的发生不外乎内、外二因,心脾积热是导致唇风发生的关键因素.治疗小儿唇风,重在清心泻脾,扶正祛邪.内治法采用泻黄散合导赤散加减为主方,外治法配合本院自制黄连膏,在临床应用中取得满意疗效.     

从厥阴“络”“风”角度探讨高血压

高血压是心脑血管疾病最主要的危险因素，影响心、脑、肾等人体重要脏器的结构和功能。目前，我国高血压患病率居高不下，如何有效遏制高血压的发病率，减轻高血压患者靶器官损害，是眼下亟需解决的难题。中国传统医学，因为其独特的疗效和优势，目前正越来越多地在世界各地广泛应用。中医认为“风邪”是高血压发生发展的主要因素，且贯穿始终；与此同时，也有学者认为高血压位在络，络脉病变亦是高血压发生发展的重要原因。络病、风邪与高血压发生发展及心、脑、肾等靶器官损害疾病密切相关。从伤寒六经辨证角度来看，“络”“风”与厥阴关系密切，络病属厥阴，风邪始于厥阴，高血压的发生发展、持续存在与厥阴病密切相关。本文从厥阴“络”“风”角度浅析高血压的病机与论治，具体论述厥阴“络”“风”与高血压的关系，认为厥阴风火内郁，肝火上冲；厥阴虚损，肝风内动、络虚风动；厥阴外感，外风引动是导致高血压发生发展，心、脑、肾等靶器官损害的重要病机，并基于厥阴主方乌梅丸探讨厥阴“络”“风”同治之法。六经统百病，开后世之门径，基于厥阴“络”“风”角度探讨高血压病机与论治，对指导高血压的防治、减轻高血压患者靶器官损害、持续改善心脑血管病预后具有重要意义。     

Shear Behavior Models of Steel Fiber Reinforced Concrete Beams Modifying Softened Truss Model Approaches

Recognizing that steel fibers can supplement the brittle tensile characteristics of concrete, many studies have been conducted on the shear performance of steel fiber reinforced concrete (SFRC) members. However, previous studies were mostly focused on the shear strength and proposed empirical shear strength equations based on their experimental results. Thus, this study attempts to estimate the strains and stresses in steel fibers by considering the detailed characteristics of steel fibers in SFRC members, from which more accurate estimation on the shear behavior and strength of SFRC members is possible, and the failure mode of steel fibers can be also identified. Four shear behavior models for SFRC members have been proposed, which have been modified from the softened truss models for reinforced concrete members, and they can estimate the contribution of steel fibers to the total shear strength of the SFRC member. The performances of all the models proposed in this study were also evaluated by a large number of test results. The contribution of steel fibers to the shear strength varied from 5% to 50% according to their amount, and the most optimized volume fraction of steel fibers was estimated as 1%–1.5%, in terms of shear performance.     

Cyclic Deformation of Ultra-Fine Grained Commercial Purity Aluminum Processed by Accumulative Roll-Bonding

Accumulative Roll-Bonding (ARB) is one of the more recently developed techniques capable of producing bulk ultra-fine grained (ufg) metals. There are still many aspects of the behavior of ufg metals that lacks an in-depth understanding, such as a generalized view of the factors that govern the cyclic deformation mechanism(s). This study aims to advance the understanding of the cyclic deformation behavior of ufg metals through the systematic investigation of ARB processed aluminum upon cyclic loading. It was found that the cyclic softening response often reported for ufg metals is largely influenced by the microstructure stability as the cyclic softening response is facilitated by grain coarsening which becomes inhibited with highly stable microstructure. On one hand, shear bands resembling braids of dislocations trespassing multiple grains have been observed to operate for the accommodation of the imposed cyclic strain in cases where grain coarsening is largely restricted. On the other hand, it was found that the microstructure stability can be overcome at higher applied cyclic plastic strain levels, leading to grain coarsening and thus a cyclic softening response. The findings in this study have further confirmed that the cyclic softening behavior found in many ufg metals, which may be detrimental in practical applications, can be inhibited by improvements in the microstructure stability.     

Challenges and Considerations When Using Shear Wave Elastography to Evaluate the Transplanted Kidney,With Pictorial Review

The gold standard in evaluating renal allograft dysfunction has traditionally been renal biopsy. However, not only does biopsy come with inherent risks, the time frame from biopsy to detecting renal dysfunction is often inefficient. It is therefore advantageous to have a noninvasive, low‐cost, time‐saving method, such as shear wave elastography (SWE), to detect fibrosis early, to maximize immunosuppressive care. It is important to consider factors that affect tissue stiffness in the kidney, as well as the challenges incurred when using SWE in this anisotropic organ, in order to select the most appropriate patients for this exam.