BACKGROUND & AIMS: :An analytical treatment of the piezoelectric ceramic complete ring transducer undergoing flexural vibrations is presented. Conditions for the electromechanical excitation of the flexural vibrations are discussed and it is shown that the fundamental mode of the flexural vibration of a complete ring can be considered as sufficiently dominant over a broad frequency range. Hence, the one-dimensional equivalent electromechanical circuit representation of the transducer is applicable and all the parameters of the equivalent circuit are determined. Possibilities to optimize the effective coupling coefficient of the transducer by changing the extent of the electrodes on the piezoelectric body are considered. It is shown that for effective operation of the flexural ring transducer as a low frequency hydroacoustic projector the opposing quadrants (or three quadrants in case of a planar array configuration) have to be covered with baffles. The radiation impedance and directional factors of the transducers with baffles are considered. Limitations of the acoustical power radiated by the transducers are discussed.

背景与目标： : 提出了对承受弯曲振动的压电陶瓷完整环形换能器的分析处理。讨论了弯曲振动的机电激励条件，表明完整环的弯曲振动的基本模式可以认为在很宽的频率范围内具有足够的优势。因此，换能器的一维等效机电电路表示是适用的，并且确定了等效电路的所有参数。考虑了通过改变压电体上电极的范围来优化换能器有效耦合系数的可能性。表明，为了有效地将弯曲环换能器用作低频水声投影仪，必须用挡板覆盖相对的象限 (在平面阵列配置的情况下为三个象限)。考虑了带挡板的换能器的辐射阻抗和方向因子。讨论了换能器辐射的声功率的局限性。

BACKGROUND & AIMS: :Signal transducers and activators of transcriptions (STAT) are key mediators of cytokine signaling. Moreover, these transcription factors play a crucial role in oncogenic signaling where inappropriate and sustained activation of STATs, especially STAT3, is a trait of many different cancers and their derived cell lines. Constitutively active STAT3 has been reported to prevent programmed cell death and enhance cell proliferation, whereas the disruption of STAT3 signaling can inhibit tumor growth. The physiologic activation of STAT3 by cytokines has been well established; however, little is known about altered, stimulation-independent STAT3 activation. Here, we show that, in most but not all melanoma cell lines, STAT3 phosphorylation increased substantially with cell density and that this STAT3 was able to bind to DNA and to activate transcription. Inhibitor studies showed that the cell density-dependent STAT3 activation relies on Janus kinases (JAK) rather than Src kinases. Using a specific JAK inhibitor, sustained STAT3 activation was completely abrogated in all tested melanoma lines, whereas inhibition of Src or mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1/2 had no effect on constitutively tyrosine-phosphorylated STAT3 levels. Although STAT3 activation was completely blocked with JAK inhibitor I and to a lesser extent with the common JAK inhibitor AG490, only the latter compound markedly decreased proliferation and induced apoptosis. Taken together, variations in cell density can profoundly modify the extent of JAK-mediated persistent STAT3 phosphorylation; however, STAT3 activation was not sufficient to provide critical growth and survival signals in melanoma cell lines.

背景与目标： : 信号转导子和转录激活子 (STAT) 是细胞因子信号传导的关键介质。此外，这些转录因子在致癌信号传导中起着至关重要的作用，其中STATs (尤其是STAT3) 的不适当和持续激活是许多不同癌症及其衍生细胞系的特征。据报道，组成型活性STAT3可防止程序性细胞死亡并增强细胞增殖，而STAT3信号传导的破坏可抑制肿瘤生长。细胞因子对STAT3的生理激活已得到充分证实; 然而，对于改变的，与刺激无关的STAT3激活知之甚少。在这里，我们显示，在大多数但不是所有的黑色素瘤细胞系中，STAT3磷酸化随细胞密度而显着增加，并且该STAT3能够结合DNA并激活转录。抑制剂研究表明，细胞密度依赖性STAT3激活依赖于Janus激酶 (JAK) 而不是Src激酶。使用特定的JAK抑制剂，在所有测试的黑素瘤品系中，持续的STAT3活化被完全消除，而Src或丝裂原活化的蛋白激酶/细胞外信号调节激酶1/2的抑制对组成型酪氨酸磷酸化的STAT3水平没有影响。尽管JAK抑制剂I完全阻断了STAT3的激活，而常见的JAK抑制剂AG490则在较小程度上阻断了STAT3的激活，但只有后一种化合物显着降低了增殖并诱导了凋亡。总之，细胞密度的变化可以深刻地改变JAK介导的持续性STAT3磷酸化的程度; 然而，STAT3的激活不足以在黑色素瘤细胞系中提供关键的生长和存活信号。

BACKGROUND & AIMS: BACKGROUND:Point-of-injury extended focused assessment with sonography in trauma (eFAST) may identify life-threatening torso hemorrhage and expedite casualty evacuation. The purpose of this study was to compare combat medic eFAST performance between the novel and conventional ultrasound (US) transducers. METHODS:We conducted a randomized crossover trial. Medic participants, previously naïve to US, were randomized to the type of transducer first utilized. The primary outcome was eFAST completion time in seconds. Secondary outcomes included diagnostic accuracy, technical adequacy, and transducer ease-of-use rating. RESULTS:Forty medics performed 160 eFASTs. We found a statistically significant difference in eFAST completion times in favor of conventional transducers (304 vs. 358 s; P = 0.03). There was no statistically significant difference between the conventional and novel transducers in terms of diagnostic accuracy (97.7% vs. 96.0%; P = 0.25) and technical adequacy (65% vs. 72.5%; P = 0.11). Median transducer ease-of-use rating (Likert 1-5 scale) was statistically significant in favor of the conventional transducers (5 vs. 4; P = < 0.001). CONCLUSIONS:Extended focused assessment with sonography in trauma exam times was faster with the conventional transducers. Combat medics performed diagnostically accurate eFASTs with both transducer types in a simulated aid station setting after a brief training intervention. Conventional transducers were rated higher for ease-of-use.

背景与目标：

BACKGROUND & AIMS: :Monomeric G-proteins, also referred to as small GTPases, function as biological hubs being activated by extracellular stimuli and regulate downstream signalling events, which result in different cellular responses. The importance of these mechanisms is mirrored by the fact that several pathological conditions, including allergic asthma, are associated with derailed GTPases signalling. For this reason attention has been focused on the role of monomeric G-proteins and their effectors in airway (patho)physiology. In this article we review our current knowledge on the regulation and functions of Ras and Rho GTPase signalling under physiological and pathophysiological conditions in the pulmonary system. Based on recent findings concerning novel regulatory proteins for Ras family members, we further discuss potential future directions for therapeutical interventions in asthma.

背景与目标： : 单体g蛋白，也称为小gtp酶，充当被细胞外刺激激活的生物枢纽，并调节下游信号传导事件，从而导致不同的细胞反应。这些机制的重要性反映在以下事实中: 包括过敏性哮喘在内的几种病理状况与脱轨的GTPases信号有关。由于这个原因，人们的注意力集中在单体g蛋白及其效应子在气道 (病理) 生理学中的作用。在这篇文章中，我们回顾了我们目前关于Ras和Rho GTPase信号在肺系统的生理和病理生理条件下的调节和功能的知识。基于有关新颖的最新发现ras家族成员的调节蛋白，我们进一步讨论了哮喘治疗干预的潜在未来方向。

BACKGROUND & AIMS: :p53 protein is a well-known tumor suppressor factor that regulates cellular homeostasis. As it has several and key functions exerted, p53 is known as "the guardian of the genome" and either loss of function or gain of function mutations in the TP53 coding protein sequence are involved in cancer onset and progression. The Hippo pathway is a key regulator of developmental and regenerative physiological processes but if deregulated can induce cell transformation and cancer progression. The p53 and Hippo pathways exert a plethora of fine-tuned functions that can apparently be in contrast with each other. In this review, we propose that the p53 status can affect the Hippo pathway function by switching its outputs from tumor suppressor to oncogenic activities. In detail, we discuss: (a) the oncogenic role of the protein complex mutant p53/YAP; (b) TAZ oncogenic activation mediated by mutant p53;

背景与目标： : p53蛋白是一种众所周知的肿瘤抑制因子，可调节细胞内稳态。由于p53具有多种关键功能，因此被称为 “基因组的守护者”，TP53编码蛋白序列中的功能丧失或功能突变的获得都与癌症的发生和发展有关。Hippo途径是发育和再生生理过程的关键调节剂，但如果放松管制，则可以诱导细胞转化和癌症进展。p53和Hippo途径发挥了许多微调功能，显然可以相互对比。在这篇综述中，我们提出p53状态可以通过将其输出从肿瘤抑制因子转换为致癌活性来影响Hippo途径的功能。详细地，我们讨论了 :( a) 蛋白质复合物突变体p53/YAP的致癌作用; (b) 突变p53介导的TAZ致癌激活;

BACKGROUND & AIMS: UNLABELLED:Most neurological diseases are associated with chronic inflammation initiated by the activation of microglia, which produce cytotoxic and inflammatory factors. Signal transducers and activators of transcription (STATs) are potent regulators of gene expression but contribution of particular STAT to inflammatory gene expression and STAT-dependent transcriptional networks underlying brain inflammation need to be identified. In the present study, we investigated the genomic distribution of Stat binding sites and the role of Stats in the gene expression in lipopolysaccharide (LPS)-activated primary microglial cultures. Integration of chromatin immunoprecipitation-promoter microarray data and transcriptome data revealed novel Stat-target genes including Jmjd3, Ccl5, Ezr, Ifih1, Irf7, Uba7, and Pim1. While knockdown of individual Stat had little effect on the expression of tested genes, knockdown of both Stat1 and Stat3 inhibited the expression of Jmjd3 and inflammatory genes. Transcriptional regulation of Jmjd3 by Stat1 and Stat3 is a novel mechanism crucial for launching inflammatory responses in microglia. The effects of Jmjd3 on inflammatory gene expression were independent of its H3K27me3 demethylase activity. Forced expression of constitutively activated Stat1 and Stat3 induced the expression of Jmjd3, inflammation-related genes, and the production of pro-inflammatory cytokines as potently as lipopolysacharide. Gene set enrichment and gene function analysis revealed categories linked to the inflammatory response in LPS and Stat1C + Stat3C groups. We defined upstream pathways that activate STATs in response to LPS and demonstrated contribution of Tlr4 and Il-6 and interferon-γ signaling. Our findings define novel direct transcriptional targets of Stat1 and Stat3 and highlight their contribution to inflammatory gene expression. KEY MESSAGE:Combined analysis of genomic Stat occupancy and transcriptome revealed novel Stat target genes in LPS-induced microglia. Jmjd3 transcription factor is a novel transcriptional target of Stat1 and Stat3. Stat1 and Stat3 cooperate with Jmjd3 to induce the expression of pro-inflammatory genes. Constitutively active Stat1 and Stat3 fully mimic the LPS-induced upregulation of inflammatory genes and secretion of cytokines.

背景与目标：

BACKGROUND & AIMS: :Haem-containing proteins such as haemoglobin and myoglobin play an essential role in oxygen transport and storage. Comparison of the amino-acid sequences of globins from Bacteria and Eukarya suggests that they share an early common ancestor, even though the proteins perform different functions in these two kingdoms. Until now, no members of the globin family have been found in the third kingdom, Archaea. Recent studies of biological signalling in the Bacteria and Eukarya have revealed a new class of haem-containing proteins that serve as sensors. Until now, no haem-based sensor has been described in the Archaea. Here we report the first myoglobin-like, haem-containing protein in the Archaea, and the first haem-based aerotactic transducer in the Bacteria (termed HemAT-Hs for the archaeon Halobacterium salinarum, and HemAT-Bs for Bacillus subtilis). These proteins exhibit spectral properties similar to those of myoglobin and trigger aerotactic responses.

背景与目标： 含血红素的蛋白质，如血红蛋白和肌红蛋白，在氧气运输和储存中起着至关重要的作用。来自细菌和真核生物的球蛋白的氨基酸序列的比较表明，即使蛋白质在这两个王国中具有不同的功能，它们也具有早期的共同祖先。直到现在，在第三王国古菌 (Archaea) 中还没有发现珠蛋白家族的成员。最近对细菌和真核生物中的生物信号传导的研究揭示了一类新的含血红素的蛋白质作为传感器。到目前为止，古细菌中还没有描述过基于血红素的传感器。在这里，我们报告了古细菌中第一个类似肌红蛋白的含血红素的蛋白质，以及细菌中第一个基于血红素的航空趋化换能器 (古细菌盐藻称为HemAT-Hs，枯草芽孢杆菌称为HemAT-Bs)。这些蛋白质表现出与肌红蛋白相似的光谱特性，并触发了航空反应。

BACKGROUND & AIMS: :Male breast cancer (MBC) is a rare hormone-driven disease often associated with obesity. HMG-CoAR is the central enzyme of the mevalonate pathway, a molecular route deputed to produce cholesterol and steroid-based hormones. HMG-CoAR regulates the oncogenic Hippo transducers TAZ/YAP whose expression was previously associated with shorter survival in MBC. 225 MBC samples were immunostained for HMG-CoAR and 124 were considered eligible for exploring its relationship with hormone receptors (ER, PgR, AR), Hippo transducers and survival outcomes. HMG-CoAR was positively associated with the expression of hormone receptors (ER, PgR, AR) and Hippo transducers. Overall survival was longer in patients with HMG-CoAR-positive tumors compared with their negative counterparts (p = 0.031). Five- and 10-year survival outcomes were better in patients whose tumors expressed HMG-CoAR (p = 0.044 and p = 0.043). Uni- and multivariate analyses for 10-year survival suggested that HMG-CoAR expression is a protective factor (HR 0.50, 95% CI: 0.25-0.99, p = 0.048 and HR 0.53, 95% CI: 0.26-1.07, p = 0.078). Results were confirmed in a sensitivity analysis by excluding uncommon histotypes (multivariate Cox: HR 0.45, 95% CI: 0.21-0.97, p = 0.043). A positive relationship emerged between HMG-CoAR, hormone receptors and TAZ/YAP, suggesting a connection between the mevalonate pathway, the hormonal milieu and Hippo in MBC. Moreover, HMG-CoAR expression may be a favorable prognostic indicator.

背景与目标： 男性乳腺癌 (MBC) 是一种罕见的激素驱动疾病，通常与肥胖相关。HMG-CoAR是甲羟戊酸途径的中心酶，甲羟戊酸途径是一种产生胆固醇和类固醇激素的分子途径。HMG-CoAR调节致癌Hippo换能器TAZ/YAP，其表达先前与MBC的较短生存期相关。225 MBC样品对HMG-CoAR进行免疫染色，124被认为有资格探索其与激素受体 (ER，PgR，AR)，Hippo换能器和生存结果的关系。HMG-CoAR与激素受体 (ER，PgR，AR) 和Hippo换能器的表达呈正相关。与阴性患者相比，HMG-CoAR阳性患者的总生存期更长 (p   =   0.031)。肿瘤表达HMG-CoAR的患者 (p   =   0.044，p   =   0.043) 5年和10年的生存结局较好。10年生存率的单因素和多因素分析表明，HMG-CoAR表达是一种保护因子 (HR 0.50，95% ci ci: 0.25-0.99，p   =   0.048和HR 0.53，95%  CI: 0.26-1.07，p   =   0.078)。通过排除不常见的组织类型 (多变量Cox: HR 0.45，95%  CI: 0.21-0.97，p   =   0.043)，在敏感性分析中证实了结果。HMG-CoAR，激素受体和TAZ/YAP之间出现正相关关系，表明MBC中的甲羟戊酸途径，激素环境和河马之间存在联系。此外，HMG-CoAR表达可能是有利的预后指标。

BACKGROUND & AIMS: :Diaphragm pressure transducers are designed to measure pressures in fluids, but have also been applied to measuring pressures on soft materials, such as at the interface between the residual limb of a lower-limb amputee and the supporting surface defined by the prosthetic socket. The reliability and accuracy of Kulite XTM-190 transducer as a pressure monitor on soft materials, such as silicone and Pelite was evaluated in three physical model set-ups. The evaluations included the uniform loading of solid disks of silicone and Pelite, the application of air pressure to the core of a contained thick-walled cylinder made of silicone, and the dynamic indentation of a contained solid silicone cylinder. Sensor measurements in all situations were similar to analytical, iterative or finite element solutions when certain conditions were met. These conditions include: (i) lubricating the interface between the soft material and the supporting structure; (ii) calibrating the transducers under surface and material conditions used during measurements; and (iii) using compatible soft materials (e.g. silicone but not Pelite).

背景与目标： : 隔膜压力传感器被设计用于测量流体中的压力，但也已应用于测量软材料上的压力，例如在下肢截肢者的残肢与由假肢窝限定的支撑表面之间的界面处。在三个物理模型设置中评估了Kulite XTM-190传感器作为软材料 (例如硅树脂和Pelite) 上的压力监测器的可靠性和准确性。评估包括均匀加载硅树脂和Pelite的实心圆盘，将气压施加到由硅树脂制成的内置厚壁圆柱体的核心以及内置的实心硅树脂圆柱体的动态压痕。当满足某些条件时，所有情况下的传感器测量都类似于解析，迭代或有限元解决方案。这些条件包括 :( i) 润滑软材料和支撑结构之间的界面; (ii) 在测量过程中使用的表面和材料条件下校准换能器; 以及 (iii) 使用兼容的软材料 (例如硅树脂而不是Pelite)。

BACKGROUND & AIMS: :Ultrasound speckle is a consequence of the stochastic nature of the reflectivity of scattering media (e.g., biological tissue) and of the coherent nature of piezoelectric transducers. This speckle noise can be reduced by the use of incoherent processing techniques (e.g., spatial compounding, incoherent summation, random phase and phase insensitive transducers). We present a unified framework that explains the limitations of incoherent processing in terms of the information grain theory. This theory predicts the gains in SNR as well as the losses in directivity. We also present the random phase transducer approach to incoherence to total coherence. We present applications to speckle reduction, detection of specular reflectors, attenuation estimation and ultrasound imaging. We show that totally incoherent transducers completely remove diffraction effects. They might be used in attenuation estimation, in which case, correction for diffraction is no longer required, in order to obtain unbiased estimates. Partially coherent transducers might also be useful in imaging to reduce speckle noise.

背景与目标： : 超声斑点是散射介质 (例如生物组织) 的反射率的随机性质和压电换能器的相干性质的结果。可以通过使用非相干处理技术 (例如，空间复合，非相干求和，随机相位和相位不敏感的换能器) 来降低斑点噪声。我们提出了一个统一的框架，该框架根据信息谷物理论解释了不连贯处理的局限性。该理论预测了SNR的收益以及方向性的损失。我们还介绍了随机相位换能器方法，以使其与总相干性不一致。我们介绍了在散斑减少，镜面反射器的检测，衰减估计和超声成像方面的应用。我们证明了完全不相干的换能器完全消除了衍射效应。它们可以用于衰减估计，在这种情况下，不再需要衍射校正，以便获得无偏估计。部分相干换能器也可能在成像中以减少斑点噪声中有用。

BACKGROUND & AIMS: OBJECTIVE:This safety study was designed to investigate tissue heating close to the surface of transvaginal ultrasound transducers, with the objective of assessing the validity of manufacturing safety standards set by the International Electrotechnical Commission (IEC). METHODS:The transducers investigated in this study were held in contact with a layered soft-tissue mimicking material (TMM), and the temperature increase was measured at various depths using a miniature thermocouple. The temperature rise at 200 s was recorded, and the measured profiles of temperature rise with depth were compared with profiles predicted from both analytical and numeric models. Two transvaginal transducers of different manufacturers were investigated, operating in B-mode imaging, color-flow imaging and pulsed Doppler modes, using scanner settings giving acoustic output power towards the upper end of that available. RESULTS:The greatest heating always occurred at the interface between the transducer and the TMM, and it reduced to about 0.1 times the surface temperature rise at a depth of 1 cm. A local maximum was observed in pulsed Doppler mode. A three-dimensional finite-element model which accounted for transducer dimensions gave a better prediction of temperature increase than a simple analytical model. The temperature profiles were compared with the depth of fetal tissue measured from a small survey of clinical scans. CONCLUSIONS:It is provisionally concluded that the transducer surface temperature rise of 6 degrees C allowed to manufacturers by the IEC may give rise to an associated worst-case contribution to temperature rise due to the transducer, in fetal tissue, of between 0.5 and 1 degrees C at 1-cm depth. The contribution to tissue heating at 2 cm and deeper is negligible. Published by John Wiley & Sons, Ltd.

背景与目标：

BACKGROUND & AIMS: :The transcription factors signal transducers and activators of transcription (STAT)5a and STAT5b (STAT5) are essential mediators of many actions of GH, including transcription of the IGF-I gene. Here, we present evidence that skeletal muscle STAT5 is important for postnatal growth and suggest that this is conveyed by the production of localized IGF-I. To investigate the role of STAT5 signaling in skeletal muscle, mice with a skeletal-muscle-specific deletion of the Stat5a and Stat5b genes (Stat5MKO mice) were used. IGF-I mRNA levels were reduced by 60% in muscle tissue of these mice. Despite only a 15% decrease in circulating IGF-I, 8-wk-old male Stat5MKO mice displayed approximately 20% reduction in body weight that was accounted for by a reduction in lean mass. The skeletons of Stat5MKO mice were found to be smaller than controls, indicating the growth defect was not restricted to skeletal muscle. These results demonstrate an as yet unreported critical role for STAT5 in skeletal muscle for local IGF-I production and postnatal growth and suggest the skeletal muscle as a major site of GH action.

背景与目标： : 转录因子信号转导子和转录激活子 (STAT)5a和STAT5b (STAT5) 是GH许多作用的重要介质，包括igf-i基因的转录。在这里，我们提供证据表明骨骼肌STAT5对出生后的生长很重要，并表明这是通过局部igf-i的产生来传达的。为了研究STAT5信号在骨骼肌中的作用，使用了骨骼肌特异性缺失Stat5a和Stat5b基因的小鼠 (Stat5MKO小鼠)。这些小鼠的肌肉组织中的60% 降低了igf-i mRNA水平。尽管只有循环igf-i的15% 降低，8周龄的雄性Stat5MKO小鼠表现出约20% 的体重减少，这是由于瘦体重的减少所致。发现Stat5MKO小鼠的骨骼小于对照组，表明生长缺陷不仅限于骨骼肌。这些结果表明STAT5在骨骼肌中对于局部igf-i的产生和产后生长起着尚未报道的关键作用，并表明骨骼肌是GH作用的主要部位。

BACKGROUND & AIMS: :Two possible methods to determine the spatial average temporal average intensity I(sata) and ultrasonic power W in composite ltrasonic transducers for medical application are described. Results showed that integrals using one method will yield accurate results but a vast amount of computational effort is required. On the other hand, using an alternative method these integrals may readily be solved at the expense of the accuracy of the results deduced.

背景与目标： : 描述了两种可能的方法来确定用于医学应用的复合超声换能器中的空间平均时间平均强度I(sata) 和超声功率W。结果表明，使用一种方法的积分将产生准确的结果，但需要大量的计算量。另一方面，使用另一种方法，可以很容易地解决这些积分，但要牺牲推导结果的准确性。

BACKGROUND & AIMS: :This paper presents novel micromachined two-dimensional array piezoelectrically actuated flextensional transducers that can be used to generate sound in air or water. Micromachining techniques to fabricate these devices are also presented. Individual unimorph array elements consist of a thin piezoelectric annular disk and a thin, fully clamped, circular plate. We manufacture the transducer in two-dimensional arrays using planar silicon micromachining and demonstrate ultrasound transmission in air at 2.85 MHz with 0.15 microm/V peak displacement. The devices have a range of operating resonance frequencies starting from 450 kHz up to 4.5 MHz. Such an array could be combined with on-board driving and addressing circuitry for different applications.

背景与目标： : 本文介绍了新型的微机械二维阵列压电驱动的挠曲张换能器，可用于在空气或水中产生声音。还介绍了制造这些设备的微加工技术。单个单压电晶片阵列元件由薄的压电环形盘和薄的，完全夹紧的圆板组成。我们使用平面硅微加工在二维阵列中制造换能器，并演示了在2.85 MHz的空气中具有0.15 microm/V峰值位移的超声传输。这些器件具有从450 kHz到4.5 MHz开始的一系列工作谐振频率。这样的阵列可以与用于不同应用的车载驱动和寻址电路结合使用。

BACKGROUND & AIMS: :Differences in tissue heating rates between ultrasound transducers have been well documented; however, comparative analysis between ultrasound fields to determine why tissue heating rates may differ is lacking. We selected three transducers from the same manufacturer with similar effective radiating area, output power, effective intensity and beam nonuniformity ratio [as defined by the FDA, 21 CFR Chap. 1, part 1,050 (10)], but markedly different Schlieren images. Each transducer was utilized to heat tissue with a standardized ultrasound application to determine whether Schlieren analysis may be useful in understanding variability in tissue heating rates. Thermocouples were inserted into the left triceps surae of 12 volunteers at a depth of 1.5 cm below one half the measured skin fold thickness (estimated average depth of the thermocouple was 1.99 +/- 0.27 cm). Each subject received one treatment from each transducer in a single session (n = 3); 3 MHz at 1.2 W/cm(2) for 8 min with a 100% duty cycle. Each transducer increased the IM temperature over time (p < 0.0001). IM temperatures were not significantly different between transducers from time zero to the fourth minute of treatment. After the fourth min, transducers B and C generated significantly higher tissue temperatures (p < 0.01). Transducer A, B and C increased IM temperature from 34.9 +/- 0.5 to 41.2 +/- 1.3 degrees C, 34.9 +/- 0.6 to 42.5 +/- 1.4 degrees C and 34.9 +/- 0.5 to 42.7 +/- 1.7 degrees C, respectively. Interestingly, transducer C emitted 22% lower output power but heated 24% higher than transducer A and our Schlieren images demonstrate that transducers B and C produced a more concentrated field compared with transducer A. The data we present here supports the general contention that a more concentrated field will heat to a higher temperature than a more disperse field, however, technical challenges in estimating output power, ERA and Schlieren analysis remain an issue.

背景与目标： : 超声换能器之间的组织加热速率差异已得到充分记录; 但是，缺乏超声场之间的比较分析以确定为什么组织加热速率可能不同。我们从同一制造商中选择了三个换能器，它们具有相似的有效辐射面积，输出功率，有效强度和光束不均匀性比 [由FDA，21 CFR第1章，第1,050 (10) 部分定义]，但明显不同的Schlieren图像。利用每个换能器通过标准化的超声应用来加热组织，以确定Schlieren分析是否有助于理解组织加热速率的变异性。将热电偶插入到12名志愿者的左肱三头肌中，深度1.5厘米低于测得的皮肤褶皱厚度的一半 (热电偶的估计平均深度为1.99 +/-0.27厘米)。每个受试者在单个会话 (n = 3) 中从每个换能器接受一次治疗; 在1.2 W/cm(2) 下3 MHz，持续8分钟，具有100% 的占空比。每个换能器随时间增加IM温度 (p <0.0001)。从零点到治疗的第四分钟，换能器之间的IM温度没有显着差异。在第四分钟后，换能器B和C产生明显更高的组织温度 (p <0.01)。换能器A、B和C分别将IM温度从34.9 +/- 0.5增加到41.2 +/- 1.3 ℃，34.9 +/- 0.6到42.5 +/- 1.4 ℃，34.9 +/- 0.5到42.7 +/- 1.7 ℃。有趣的是，与换能器A相比，换能器C发射22% 更低的输出功率，但加热的24% 更高，并且我们的Schlieren图像表明，与换能器a相比，换能器B和C产生了更集中的场。我们在这里提供的数据支持了一个普遍的论点，即更集中的场将比更分散的场加热到更高的温度，但是，估计输出功率，ERA和Schlieren分析的技术挑战仍然是一个问题。