这项工作部分得到了美国陆军医学研究材料司令部W81XWH-08-1-0503和W81XWH-12-1-0066的支持，AHA授予No0655441U和15SDG25740015以及NIH R21 HL081892，R21 HL130899，R21 HL089175，RC1 DK087365，R01 DK098526，R01 DK118964，R01 CA140338，R01 CA234428，Lantheus Medical Imaging和GE Healthcare，挪威奥斯陆。

托马斯杰斐逊大学和宾夕法尼亚大学医院的机构审查委员会批准了该协议。该协议符合《健康保险流通与责任法案》。美国食品和药物管理局（FDA）为该协议发布了研究性新药批准（IND # 124，465至F. Forsberg）。GE Healthcare（挪威奥斯陆）提供了本研究中使用的UCA（Sonazoid; 表 1）。Sonazoid未被FDA批准用于美国的任何临床应用，这就是为什么需要IND的原因。其他获得 FDA 批准1 的 UCA 如果认为有潜在的临床有用，可以由主治医生自行决定在标签外使用。
注意:完整的协议和统计分析计划可在 https:// clinicaltrials.gov/ct2/show/NCT02489045 获得。试验注册号:NCT # 02489045。
1. 科目准备
<ol><li>查看受试者已知的药物过敏或不耐受，特别是对正在使用的UCA的任何已知过敏。</li>
	<li>排除心肺疾病不稳定或通常医学不稳定的受试者。</li>
	<li>将受试者仰卧放在担架上。</li>
	<li>将 18 - 22 号套管放在受试者右臂或左臂的静脉中以进行 UCA 输注。</li>
	<li>确保医院内提供紧急服务（例如，急救车），以防出现任何急性不良反应。 注意:UCA非常安全，报告的严重类过敏反应发生率低于0.01%。20</li>
</ol>2. UCA制备（特定于声纳肽）
<ol><li>根据制造商的说明重悬，为每个受试者准备三 （3） 个装有 48 μL 微气泡 （6 mL） 的小瓶。UCA 以干粉形式提供，装在 10 mL 密封小瓶中。小瓶的顶部空间含有全氟丁烷。<ol><li>用化学尖刺穿UCA小瓶的塞子。</li>
		<li>从化学尖峰的注射器端口取下保护帽，并加入2mL无菌水。</li>
		<li>将注射器留在化疗尖峰上，立即摇动产品 1 分钟以确保产品均匀。</li>
		<li>将产品撤回注射器，然后再次将产品重新注入小瓶中。这是为了避免由于化学尖峰中的死区体积而导致产品稀释。</li>
		<li>从注射器端口取出注射器并重新安装保护盖。重组UCA的浓度为8 μL微泡/mL。</li>
		<li>对其他2个小瓶重复复溶程序。</li>
	</ol></li>
	<li>在连接到 3 通旋塞阀之前，使用生理盐水（0.9% NaCl 溶液）填充连接管。然后，旋塞阀将连接到通向套管的延长管。</li>
	<li>将所有三 （3） 瓶悬浮的 UCA 抽入 10 mL 注射器中，并将其放入患者相同水平或下方的注射泵中，并直接连接到旋塞阀。</li>
	<li>在初始超声成像和旋塞阀打开后，以 120 mL/h 的速度输注 NaCl 溶液，并以每公斤体重每分钟 0.024 μL 的速率共同输注 Sonazoid（悬浮输注速率为 0.18 mL/kg/小时）。 注意:该输注速率是根据我们小组以前在接受SHAPE13，14，21的门静脉高压受试者中输注声纳样的经验选择的。确切的重悬程序和输液方法将根据所使用的UCA而有所不同。</li>
</ol>3. 初始超声成像
<ol><li>打开超声扫描仪（例如 Logiq E10 版本 R2）的电源并选择 C1-6-D 曲线探头。</li>
	<li>在超声扫描仪上选择一个腹部预设，并使用曲线阵列（通常具有1-6或2-8 MHz带宽）在同一成像平面和相似深度获取门静脉和肝静脉的灰度图像（图1）。这通常最好通过肋下方法来实现。</li>
	<li>根据良好临床实践优化图像，并注意选择远离下腔静脉的肝静脉区域，以避免逆行血流的影响。</li>
</ol>4. SHI 和形状成像
<ol><li>使用 次谐波对比度 触摸屏按钮在双显示模式下激活 SHI 对比度成像模式（即同时运行实时 B 模式和 SHI），并激活对比度模式。然后在旋转控制器上选择 SUBH-AM 。<ol><li>以 2.5 MHz 的发射频率执行 SHI，并在 1.25 MHz 处获得接收信号。</li>
		<li>使用脉冲整形来最大限度地产生次谐波微气泡信号，例如带有声纳样的高斯窗口二项式滤波方波，21 但这依赖于扫描仪和 UCA。17 注:最终用户可能无法选择成像频率和脉冲形状。</li>
	</ol></li>
	<li>确认门静脉和肝静脉的通畅性以及微气泡的存在，从输注开始可能需要长达1-2分钟。</li>
	<li>激活 SHAPE 自动优化代码，通过补偿不同的深度和衰减来优化 SHAPE。22，23 在触摸屏上选择 TIC 分析，然后选择 F6，然后选择 k 按钮。</li>
	<li>SHAPE优化算法将获取每个声学输出电平的次谐波数据。数据采集完成后，在对比样本窗口（TIC分析屏幕左上角）的门静脉上放置ROI。<ol><li>将ROI内的平均次谐波数据绘制为声学输出的函数，并将逻辑曲线拟合到数据。选择该曲线的拐点（或者更确切地说是下面显示的导数曲线中的峰值）作为优化功率，因为这已被证明是SHAPE灵敏度最高的点。22，23 图2显示了一组这样的曲线。</li>
	</ol></li>
	<li>将声学输出功率调整到步骤4.4.1中确定的值，这将确保次谐波幅度的最大变化是环境压力的函数（即，最大化SHAPE的灵敏度）。</li>
	<li>在输注UCA悬浮液期间，从5-15秒段的微气泡（即SHAPE）获取次谐波数据（图3）。</li>
</ol>5. 形状数据处理
<ol><li>获取优化的SHI电影循环（步骤5.6）后，在触摸屏上选择"TIC分析"。<ol><li>确保触摸面板上的"运动跟踪"已激活，该面板会调整每帧的ROI位置以补偿任何呼吸或其他运动。</li>
		<li>确保在分析窗口中选择dB作为迹线上Y轴的单位。</li>
	</ol></li>
	<li>在对比样本窗口（屏幕左上角）中，选择肝静脉和门静脉内相同的ROI（椭圆区域为默认）。在分析窗口（右侧）中，每个容器内的次谐波信号（以dB为单位）在1.25 MHz左右的0.5 MHz带宽内的所有帧上平均。</li>
	<li>计算最终的SHAPE梯度（以dB为单位）作为肝静脉和门静脉ROI之间平均次谐波信号的差异。根据目前的研究，识别CSPH的最佳工作点为-0.11 dB，线性回归方程为HVPG = 0.81 x SHAPE + 9.43。14 需要注意的是，这个截止值和方程都取决于扫描仪和UCA。</li>
</ol>

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Forsberg，Gupta，Wallace和Eisenbrey博士正在申请SHAPE技术的专利。华莱士博士是通用电气的员工。

长期以来，无创、准确测量人体内压力一直是一个重要但难以捉摸的临床目标。这里介绍的SHAPE测量协议实现了这一目标。SHAPE程序最关键的组成部分是优化算法，因为在最佳声功率输出下未获得的次谐波数据与静水压力的相关性较差。17，22，23 在Logiq 9扫描仪上实现的该软件的初始版本容易在S曲线的导数中显示多个峰值（参?...

许多不同的超声造影剂（UCA）被批准用于心脏病学（特别是左心室混浊）和放射学（特别是成人和儿童肝脏病变特征）的临床应用。1 超声成像的灵敏度和特异性可以通过静脉内 （IV） 注射由脂质或蛋白质外壳封装的充满气体的微气泡（直径 < 10 μm）作为 UCA 来提高，UCA 穿过整个脉管系统并将信号增强高达 30 dB。1 这些UCA不仅增强了反向散射超声信号，而且在足够的声压（>200 kPa）下，它们还充当非线性振荡器。因此，在接收到的回波中将产生重要的能量成分，范围从次谐波和谐波到超谐波频率。1，2 这些非线性信号分量可以从组织和线性气泡回波中提取（例如，使用脉冲反转），并用于创建对比特定的成像模式，例如次谐波成像（SHI），其接收频率为发射频率的一半（即f 0/2）。3 我们小组在人体临床试验中证明，SHI可以检测与各种肿瘤和组织相关的新血管和小动脉中的血流。4，5，6，7，8，9
我们提倡不使用UCA作为血管示踪剂，而是通过监测次谐波对比气泡振幅变化来作为循环系统中无创压力估计的传感器。10这种称为次谐波辅助压力估计（SHAPE）的创新技术依赖于大多数商业UCA在体外测量的次谐波信号幅度与静水压力（高达186 mmHg）之间的反线性相关性（r2>0.90），如表1所示。10，11 但是，应该注意的是，并非所有 UCA 都表现出这种行为。最值得注意的是，已经表明，来自UCA SonoVue（在美国称为Lumason）的次谐波信号最初随着静水压力的增加而上升，然后是平台期和下降阶段。12尽管如此，SHAPE提供了允许无创获得心脏和整个心血管系统的压力梯度以及肿瘤中的间质液压力的可能性。13，14，15，16，17 最近，我们在商用超声扫描仪上实现了SHAPE算法的实时版本，并提供了概念验证，即SHAPE可以提供体内压力估计，患者的左心室和右心室误差小于3 mmHg。16，17 
迄今为止，SHAPE的最多经验是诊断门静脉高压症，入组了220多名受试者，并在一项多中心试验中证实了初步发现。13，14 门静脉高压定义为门静脉与肝静脉或下腔静脉之间的压力梯度增加超过 5 mmHg，而临床上显着的门静脉高压 （CSPH） 需要梯度或等效值，肝静脉压梯度 （HVPG） ≥ 10 mmHg。18 CSPH 与胃食管静脉曲张、腹水、肝失代偿、术后失代偿和肝细胞癌的风险增加有关。18，19 发生腹水的患者三年死亡率为 50%，发生腹水自发感染的患者一年死亡率为 70%。肝硬化患者胃食管静脉曲张形成年发病率为5-10%，出血年发生率为4-15%;每次出血发作都有高达20%的死亡风险。18，19 
本手稿描述了如何使用市售设备和UCA进行SHAPE研究，重点是识别患者肝脏中的门静脉高压症。详细解释了实现估算压力变化的最高灵敏度所需的关键校准程序。

<table>
	<tbody>
		<tr>
			<td>2 mL syringe</td>
			<td>Becton Dickinson</td>
			<td>309637</td>
			<td>Used for reconstituting Sonazoid</td>
		</tr>
		<tr>
			<td>10 mL saline-filled syringe</td>
			<td>Becton Dickinson</td>
			<td>306545</td>
			<td>Used for flushing line to verify IV access</td>
		</tr>
		<tr>
			<td>500 mL saline bag</td>
			<td>Baxter Healthcare Corp</td>
			<td>2131323</td>
			<td>Used for co-infusion with Sonazoid</td>
		</tr>
		<tr>
			<td>C1-6-D curvi-linear proble</td>
			<td>GE Healthcare</td>
			<td>H40472LT</td>
			<td>Used for liver imaging</td>
		</tr>
		<tr>
			<td>Chemoprotect Spike</td>
			<td>Codan USA</td>
			<td>C355</td>
			<td>Chemospike used for reconstituting Sonazoid</td>
		</tr>
		<tr>
			<td>Discofix C Blue</td>
			<td>B. Braun Medical Inc</td>
			<td>16494C</td>
			<td>3-way stopcock</td>
		</tr>
		<tr>
			<td>Intrafix Safeset 180 cm</td>
			<td>B. Braun Medical Inc</td>
			<td>4063000</td>
			<td>Infusion tubing</td>
		</tr>
		<tr>
			<td>Logiq E10 ultrasound scanner</td>
			<td>GE Healthcare</td>
			<td>H4928US</td>
			<td>Used for conventional ultrasound imaging as well as for SHI and SHAPE</td>
		</tr>
		<tr>
			<td>Luer lock 10 mL syringe</td>
			<td>Becton Dickinson</td>
			<td>300912</td>
			<td>For infusion of Sonazoid</td>
		</tr>
		<tr>
			<td>Medfusion 3500 syringe pump</td>
			<td>Smiths Medical</td>
			<td>3500-500</td>
			<td>Used for infusing Sonazoid at 0.18 mL/kg/hour</td>
		</tr>
		<tr>
			<td>Perfusor-leitung tubing 150 mm</td>
			<td>B. Braun Medical Inc</td>
			<td>8722960</td>
			<td>Extension line enabling syringe connection to patient&#39;s IV access</td>
		</tr>
		<tr>
			<td>SHI/SHAPE software</td>
			<td>GE Healthcare</td>
			<td>H4920CI</td>
			<td>Contrast-specific imaging software</td>
		</tr>
		<tr>
			<td>Sigma Spectrum infusion system</td>
			<td>Baxter Healthcare Corp</td>
			<td>35700BAX</td>
			<td>Pump used for co-infusing saline at 120 mL/hour</td>
		</tr>
		<tr>
			<td>Sonazoid</td>
			<td>GE Healthcare</td>
			<td></td>
			<td>Gas-filled microbubble based ultrasound contrast agent</td>
		</tr>
		<tr>
			<td>sterile water, 2 mL</td>
			<td>B. Braun Medical Inc</td>
			<td></td>
			<td>Used for reconstituting Sonazoid</td>
		</tr>
		<tr>
			<td>ultrasound gel</td>
			<td>Cardinal Health</td>
			<td>USG-250BT</td>
			<td>Used for contact between probe and patient</td>
		</tr>
		<tr>
			<td>Venflon IV cannula 22GA</td>
			<td>Becton Dickinson</td>
			<td>393202</td>
			<td>Cannula needle for obtaining IV access</td>
		</tr>
	</tbody>
</table>

contrast-enhanced subharmonic aided pressure estimation (shape) using ultrasound imaging with a focus on identifying portal hypertension

长期以来，无创、准确测量人体内压力一直是一个重要但难以捉摸的临床目标。用于超声成像的造影剂是充满气体的封装微气泡（直径< 10 μm），可穿过整个脉管系统并将信号增强多达 30 dB。这些微气泡还产生非线性振荡，频率范围从次谐波（发射频率的一半）到更高次谐波。次谐波幅度与环境静水压力呈反比线性关系。这里介绍了一种能够执行实时次谐波辅助压力估计（SHAPE）的超声系统。在超声造影剂输注期间，激活了优化声学输出的算法。在此校准之后，次谐波微气泡信号（即SHAPE）对压力变化具有最高的灵敏度，可用于无创量化压力。SHAPE程序在识别肝脏门静脉高压症方面的效用是这里的重点，但该技术在许多临床场景中具有适用性。

与所有超声影像学检查一样，肝脏 SHAPE 的首要考虑因素是获得目标区域的最佳基线灰度图像，并确保（使用多普勒成像）不存在肝内门静脉分流或其他血管异常。在用于诊断门静脉高压的肝脏成像的情况下，关键是在同一深度上可视化门静脉和肝静脉，以尽量减少衰减的影响（图1）。
尽管UCA浓度不被认为是SHAPE程序10，23...

Watch this Scientific Journal Video about Contrast-Enhanced Subharmonic Aided Pressure Estimation SHAPE Using Ultrasound Imaging with a Focus on Identifying Portal Hypertension at JoVE.com

Contrast-Enhanced Subharmonic Aided Pressure Estimation SHAPE Using Ultrasound Imaging with a Focus on Identifying Portal Hypertension

通过人类慢性肝病患者的例子描述了利用注入对比微泡的次谐波超声成像（经过适当校准）无创估计环境压力的方案。

使用超声成像的对比增强次谐波辅助压力估计 （SHAPE），重点是识别门静脉高压症

Noninvasive, accurate measurement of pressures within the human body has long been an important but elusive clinical goal. Contrast agents for ultrasound ...

contrast-enhanced-subharmonic-aided-pressure-estimation-shape-using

Research

JoVE Journal

Bioengineering

Contrast-Enhanced Subharmonic Aided Pressure Estimation (SHAPE) Using Ultrasound Imaging with a Focus on Identifying Portal Hypertension

2.2K 次观看.  Thomas Jefferson University. 通过人类慢性肝病患者的例子描述了利用注入对比微泡的次谐波超声成像（经过适当校准）无创估计环境压力的方案。

视频: Contrast-Enhanced Subharmonic Aided Pressure Estimation SHAPE Using Ultrasound Imaging with a Focus on Identifying Portal Hypertension

Shape Memory Polymers for Active Cell Culture

Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent shape upon the application of a stimulus such as heat1-5. In a typical shape memory cycle, the SMP is first deformed at an elevated temperature that is higher than its transition temperature, Ttrans [either the melting temperature (Tm) or the glass transition temperature (Tg)]. The deformation is elastic in nature and mainly leads to a reduction in conformational entropy of the constituent network chains (following the rubber elasticity theory). The deformed SMP is then cooled to a temperature below its Ttrans while maintaining the external strain or stress constant. During cooling, the material transitions to a more rigid state (semi-crystalline or glassy), which kinetically traps or "freezes" the material in this low-entropy state leading to macroscopic shape fixing. Shape recovery is triggered by continuously heating the material through Ttrans under a stress-free (unconstrained) condition. By allowing the network chains (with regained mobility) to relax to their thermodynamically favored, maximal-entropy state, the material changes from the temporary shape to the permanent shape.
Cells are capable of surveying the mechanical properties of their surrounding environment6. The mechanisms through which mechanical interactions between cells and their physical environment control cell behavior are areas of active research. Substrates of defined topography have emerged as powerful tools in the investigation of these mechanisms. Mesoscale, microscale, and nanoscale patterns of substrate topography have been shown to direct cell alignment, cell adhesion, and cell traction forces7-14. These findings have underscored the potential for substrate topography to control and assay the mechanical interactions between cells and their physical environment during cell culture, but the substrates used to date have generally been passive and could not be programmed to change significantly during culture. This physical stasis has limited the potential of topographic substrates to control cells in culture.
Here, active cell culture (ACC) SMP substrates are introduced that employ surface shape memory to provide programmed control of substrate topography and deformation. These substrates demonstrate the ability to transition from a temporary grooved topography to a second, nearly flat memorized topography. This change in topography can be used to control cell behavior under standard cell culture conditions.

A method for developing cell culture substrates with the ability to change topography during culture is described. The method makes use of smart materials known as shape memory polymers that have the ability to memorize a permanent shape. This concept is adaptable to a wide range of materials and applications.

形状记忆聚合物主动细胞培养

Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent ...

科研

生物工程

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic imaging. In medical applications, one of the major limitations of optical sensing technology is its susceptibility to environmental conditions, e.g. changes in pressure and temperature, which may saturate the detection. Additionally, the clinical environment often imposes stringent limits on the size and robustness of the sensor. In this work, the combination of pulse interferometry and fiber-based optical sensing is demonstrated for ultrasound detection. Pulse interferometry enables robust performance of the readout system in the presence of rapid variations in the environmental conditions, whereas the use of all-fiber technology leads to a mechanically flexible sensing element compatible with highly demanding medical applications such as intravascular imaging. In order to achieve a short sensor length, a pi-phase-shifted fiber Bragg grating is used, which acts as a resonator trapping light over an effective length of 350 &#181;m. To enable high bandwidth, the sensor is used for sideway detection of ultrasound, which is highly beneficial in circumferential imaging geometries such as intravascular imaging. An optoacoustic imaging setup is used to determine the response of the sensor for acoustic point sources at different positions.

Optical detection of ultrasound is impractical in many imaging scenarios because it often requires stable environmental conditions. We demonstrate an optical technique for ultrasound sensing in volatile environments with miniaturization and sensitivity levels appropriate for optoacoustic imaging in restrictive scenarios, e.g. intravascular applications.

宽带超声医疗成像应用，光学检测仪

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

Microfluidic Fabrication of Polymeric and Biohybrid Fibers with Predesigned Size and Shape

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and used to dictate the shape as well as the diameter of a core stream.&#160;Grooves in the top and bottom of a microfluidic channel were designed to direct the sheath fluid and shape the core fluid.&#160;By matching the viscosity and hydrophilicity of the sheath and core fluids, the interfacial effects are minimized and complex fluid shapes can be formed.&#160;Controlling the relative flow rates of the sheath and core fluids determines the cross-sectional area of the core fluid.&#160;Fibers have been produced with sizes ranging from 300 nm to ~1 mm, and fiber cross-sections can be round, flat, square, or complex as in the case with double anchor fibers. Polymerization of the core fluid downstream from the shaping region solidifies the fibers.&#160;Photoinitiated click chemistries are well suited for rapid polymerization of the core fluid by irradiation with ultraviolet light.&#160;Fibers with a wide variety of shapes have been produced from a list of polymers including liquid crystals, poly(methylmethacrylate), thiol-ene and thiol-yne resins, polyethylene glycol, and hydrogel derivatives. Minimal shear during the shaping process and mild polymerization conditions also makes the fabrication process well suited for encapsulation of cells and other biological components.

Two adjacent fluids passing through a grooved microfluidic channel can be directed to form a sheath around a prepolymer core; thereby&#160;determining both shape and cross-section. Photoinitiated polymerization, such as thiol click chemistry, is well suited for rapidly solidifying the core fluid into a microfiber with predetermined size and shape.

预设计尺寸和形状的聚合物纤维和生物贿赂纤维的微流体制造

A &#8220;sheath&#8221; fluid passing through a microfluidic channel at low Reynolds number can be directed around another &#8220;core&#8221; stream and ...

Fabrication of a Bioactive, PCL-based "Self-fitting" Shape Memory Polymer Scaffold

Tissue engineering has been explored as an alternative strategy for the treatment of critical-sized cranio-maxillofacial (CMF) bone defects. Essential to the success of this approach is a scaffold that is able to conformally fit within an irregular defect while also having the requisite biodegradability, pore interconnectivity and bioactivity. By nature of their shape recovery and fixity properties, shape memory polymer (SMP) scaffolds could achieve defect &#8220;self-fitting.&#8221; In this way, following exposure to warm saline (~60 &#186;C), the SMP scaffold would become malleable, permitting it to be hand-pressed into an irregular defect. Subsequent cooling (~37 &#186;C) would return the scaffold to its relatively rigid state within the defect. To meet these requirements, this protocol describes the preparation of SMP scaffolds prepared via the photochemical cure of biodegradable polycaprolactone diacrylate (PCL-DA) using a solvent-casting particulate-leaching (SCPL) method. A fused salt template is utilized to achieve pore interconnectivity. To realize bioactivity, a polydopamine coating is applied to the surface of the scaffold pore walls. Characterization of self-fitting and shape memory behaviors, pore interconnectivity and in vitro bioactivity are also described.

Fabrication of a Bioactive, PCL-based &quot;Self-fitting&quot; Shape Memory Polymer Scaffold

Scaffolds capable of fitting within cranio-maxillofacial (CMF) bone defects while exhibiting osteoconductivity and bioactivity are of interest. This protocol describes the preparation of a shape memory scaffold based on polycaprolactone diacrylate (PCL-DA) using a solvent-casting particulate-leaching (SCPL) method employing a fused salt template and application of a bioactive polydopamine coating.

生物活性，PCL为基础的"自我装配"形状记忆聚合物支架的制备

Tissue engineering has been explored as an alternative strategy for the treatment of critical-sized cranio-maxillofacial (CMF) bone defects. Essential to ...

Real-time Monitoring of High Intensity Focused Ultrasound (HIFU) Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound (HMIFU)

Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An oscillatory motion is generated at the focus of a 93-element and 4.5 MHz center frequency HIFU transducer by applying a 25 Hz amplitude-modulated signal using a function generator. A 64-element and 2.5 MHz imaging transducer with 68kPa peak pressure is confocally placed at the center of the HIFU transducer to acquire the radio-frequency (RF) channel data. In this protocol, real-time monitoring of thermal ablation using HIFU with an acoustic power of 7 W on canine livers in vitro is described. HIFU treatment is applied on the tissue during 2 min and the ablated region is imaged in real-time using diverging or plane wave imaging up to 1,000 frames/second. The matrix of RF channel data is multiplied by a sparse matrix for image reconstruction. The reconstructed field of view is of 90&#176; for diverging wave and 20 mm for plane wave imaging and the data are sampled at 80 MHz. The reconstruction is performed on a Graphical Processing Unit (GPU) in order to image in real-time at a 4.5 display frame rate. 1-D normalized cross-correlation of the reconstructed RF data is used to estimate axial displacements in the focal region. The magnitude of the peak-to-peak displacement at the focal depth decreases during the thermal ablation which denotes stiffening of the tissue due to the formation of a lesion. The displacement signal-to-noise ratio (SNRd) at the focal area for plane wave was 1.4 times higher than for diverging wave showing that plane wave imaging appears to produce better displacement maps quality for HMIFU than diverging wave imaging.

Real-time Monitoring of High Intensity Focused Ultrasound HIFU Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound HMIFU

This article describes real-time monitoring of HIFU ablation in canine liver with high frame rate ultrasound imaging using diverging and plane wave imaging. Harmonic Motion Imaging for Focused Ultrasound is used to image the decrease of acoustic radiation force induced displacement in the ablated region.

高强度的实时监控聚焦超声（HIFU）消融<em&gt;体外</em&gt;使用谐运动成像的聚焦超声犬肝脏（HMIFU）

Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An ...

Double Emulsion Generation Using a Polydimethylsiloxane (PDMS) Co-axial Flow Focus Device

Double emulsions are useful in a number of biological and industrial applications in which it is important to have an aqueous carrier fluid. This paper presents a polydimethylsiloxane (PDMS) microfluidic device capable of generating water/oil/water double emulsions using a coaxial flow focusing geometry that can be fabricated entirely using soft lithography. Similar to emulsion devices using glass capillaries, double emulsions can be formed in channels with uniform wettability and with dimensions much smaller than the channel sizes. Three dimensional flow focusing geometry is achieved by casting a pair of PDMS slabs using two layer soft lithography, then mating the slabs together in a clamshell configuration. Complementary locking features molded into the PDMS slabs enable the accurate registration of features on each of the slab surfaces. Device testing demonstrates formation of double emulsions from 14 &#181;m to 50 &#181;m in diameter while using large channels that are robust against fouling and clogging.

Double Emulsion Generation Using a Polydimethylsiloxane PDMS Co-axial Flow Focus Device

Microfluidic double emulsions generation typically involves devices with patterned wettability or custom-fabricated glass components. Here we describe the fabrication and testing of an all polydimethylsiloxane (PDMS) double emulsion generator that does not require surface treatment or complicated fabrication processes, and is capable of producing double emulsions down to 14 &#181;m.

复乳代使用聚二甲基硅氧烷（PDMS）同轴流量聚焦设备

Double emulsions are useful in a number of biological and industrial applications in which it is important to have an aqueous carrier fluid. This paper ...

Conducting Multiple Imaging Modes with One Fluorescence Microscope

Fluorescence microscopy is a powerful tool to detect biological molecules in situ and monitor their dynamics and interactions in real-time. In addition to conventional epi-fluorescence microscopy, various imaging techniques have been developed to achieve specific experimental goals. Some of the widely used techniques include single-molecule fluorescence resonance energy transfer (smFRET), which can report conformational changes and molecular interactions with angstrom resolution, and single-molecule detection-based super-resolution (SR) imaging, which can enhance the spatial resolution approximately ten&#160;to twentyfold compared to diffraction-limited microscopy. Here we present a customer-designed integrated system, which merges multiple imaging methods in one microscope, including conventional epi-fluorescent imaging, single-molecule detection-based SR imaging, and multi-color single-molecule detection, including smFRET imaging. Different imaging methods can be achieved easily and reproducibly by switching optical elements. This set-up is easy to adopt by any research laboratory in biological sciences with a need for routine and diverse imaging experiments at a reduced cost and space relative to building separate microscopes for individual purposes.

Here we present a practical guide of building an integrated microscopy system, which merges conventional epi-fluorescent imaging, single-molecule detection-based super-resolution imaging, and multi-color single-molecule detection, including single-molecule fluorescence resonance energy transfer imaging, into one set-up in a cost-efficient way.

使用一个荧光显微镜进行多种成像模式

Fluorescence microscopy is a powerful tool to detect biological molecules in situ and monitor their dynamics and interactions in real-time. In addition to ...

Material Formation of Recombinant Spider Silks through Aqueous Solvation using Heat and Pressure

Many spiders produce seven types of silks. Six of the silks are fiber in form when produced by the spiders. These fibers are not water soluble. In order to reproduce the remarkable mechanical properties of spider silks, they must be produced in heterologous hosts as spiders are both territorial and cannibalistic. The synthetic analogs of spider silk also tend to be insoluble in aqueous solutions. Thus, a large percentage of research in recombinant spider silks rely upon organic solvents that are detrimental to large scale production of materials. Our group&#8217;s method forces the solvation of these recombinant spider silks into water. Remarkably, when these proteins are prepared using this method of heat and pressure, a wide range of material forms can be prepared from the same solution of recombinant spider silk proteins (rSSp) including: films, fibers, sponge, hydrogel, lyogel, and adhesives. This article demonstrates the production of the solvated rSSp and material forms in a manner that is more easily understood than from written materials and methods alone.

Here, we present a protocol to produce water soluble recombinant spider silk protein solutions and the material forms that can be formed from those solutions.

热、压水固化重组蜘蛛丝的材料形成

Many spiders produce seven types of silks. Six of the silks are fiber in form when produced by the spiders. These fibers are not water soluble. In order ...

Patient-Specific Polyvinyl Alcohol Phantom Fabrication with Ultrasound and X-Ray Contrast for Brain Tumor Surgery Planning

Phantoms are essential tools for clinical training, surgical planning and the development of novel medical devices. However, it is challenging to create anatomically accurate head phantoms with realistic brain imaging properties because standard fabrication methods are not optimized to replicate any patient-specific anatomical detail and 3D printing materials are not optimized for imaging properties. In order to test and validate a novel navigation system for use during brain tumor surgery, an anatomically accurate phantom with realistic imaging and mechanical properties was required. Therefore, a phantom was developed using real patient data as input and 3D printing of molds to fabricate a patient-specific head phantom comprising the skull, brain and tumor with both ultrasound and X-ray contrast. The phantom also had mechanical properties that allowed the phantom tissue to be manipulated in a similar manner to how human brain tissue is handled during surgery. The phantom was successfully tested during a surgical simulation in a virtual operating room.
The phantom fabrication method uses commercially available materials and is easy to reproduce. The 3D printing files can be readily shared, and the technique can be adapted to encompass many different types of tumor.

This protocol describes the fabrication of a patient specific skull, brain and tumor phantom. It uses 3D printing to create molds, and polyvinyl alcohol (PVA-c) is used as the tissue mimicking material.

患者特异性聚乙烯酒精幻影制造与超声波和X射线对比脑肿瘤手术规划

Phantoms are essential tools for clinical training, surgical planning and the development of novel medical devices. However, it is challenging to create ...

High-Dimensionality Flow Cytometry for Immune Function Analysis of Dissected Implant Tissues

The success of implanting laboratory-grown tissue or a medical device in an individual is subject to the immune response of the recipient host. Considering an implant as a foreign body, a hostile and dysregulated immune response may result in the rejection of the implant, while a regulated response and regaining of homeostasis can lead to its acceptance. Analyzing the microenvironments of implants dissected out under in vivo or ex vivo&#160;settings can help in understanding the pattern of immune response, which can ultimately help in developing new generations of biomaterials. Flow cytometry is a well-known technique for characterizing immune cells and their subsets based on their cell surface markers. This review describes a protocol based on manual dicing, enzymatic digestion, and filtration through a cell strainer for the isolation of uniform cell suspensions from dissected implant tissue. Further, a multicolor flow cytometry staining protocol has been explained, along with steps for initial cytometer settings to characterize and quantify these isolated cells by flow cytometry.

Isolation of cells from dissected implants and their characterization by flow cytometry can significantly contribute to understanding the pattern of immune response against implants. This paper describes a precise method for the isolation of cells from dissected implants and their staining for flow cytometric analysis.

使用超声成像的对比增强次谐波辅助压力估计 （SHAPE），重点是识别门静脉高压症

使用超声成像的对比增强次谐波辅助压力估计（SHAPE），重点是识别门静脉高压症