Increased Bone Resorption during Lactation in Pycnodysostosis

Pycnodysostosis, a rare autosomal recessive skeletal dysplasia, is caused by a deficiency of cathepsin K. Patients have impaired bone resorption in the presence of normal or increased numbers of multinucleated, but dysfunctional, osteoclasts. Cathepsin K degrades collagen type I and generates N-telopeptide (NTX) and the C-telopeptide (CTX) that can be quantified. Levels of these telopeptides are increased in lactating women and are associated with increased bone resorption. Nothing is known about the consequences of cathepsin K deficiency in lactating women. Here we present for the first time normalized blood and CTX measurements in a patient with pycnodysostosis, exclusively related to the lactation period. In vitro studies using osteoclasts derived from blood monocytes during lactation and after weaning further show consistent bone resorption before and after lactation. Increased expression of cathepsins L and S in osteoclasts derived from the lactating patient suggests that other proteinases could compensate for the lack of cathepsin K during the lactation period of pycnodysostosis patients.     

Targeting Intercellular Communication in the Bone Microenvironment to Prevent Disseminated Tumor Cell Escape from Dormancy and Bone Metastatic Tumor Growth

Metastasis to the bone is a common feature of many cancers including those of the breast, prostate, lung, thyroid and kidney. Once tumors metastasize to the bone, they are essentially incurable. Bone metastasis is a complex process involving not only intravasation of tumor cells from the primary tumor into circulation, but extravasation from circulation into the bone where they meet an environment that is generally suppressive of their growth. The bone microenvironment can inhibit the growth of disseminated tumor cells (DTC) by inducing dormancy of the DTC directly and later on following formation of a micrometastatic tumour mass by inhibiting metastatic processes including angiogenesis, bone remodeling and immunosuppressive cell functions. In this review we will highlight some of the mechanisms mediating DTC dormancy and the complex relationships which occur between tumor cells and bone resident cells in the bone metastatic microenvironment. These inter-cellular interactions may be important targets to consider for development of novel effective therapies for the prevention or treatment of bone metastases.     

Stretchable,Antifreezing, Non-Drying,and Fast-Response Sensors Based on Cellulose Nanocomposite Hydrogels for Signal Detection

Conductive hydrogels have received widespread attention in the applications of biosensors, human–machine interface, and health recording electrodes. Herein, the conductive hydrogels integrated with antifreezing, water retention, reusable, and sensing performances are fabricated by introducing polyvinyl alcohol, cellulose nanofibril, MXene nanosheets, and glycerol. The as-prepared hydrogels present prominent electrical conductivity (2.58 mS cm⁻¹) and flexibility even at −18 °C. In addition, the hydrogels have favorable water retention performance and can reuse after heating and cooling. When used as sensors, the hydrogels illustrate high sensitivity (gauge factor of 2.30), fast response time (0.165 s), wide working strain range (559%), favorable linearity (R² = 0.999), and wide operating temperature range (−18 to 60 °C). The hydrogels can detect not only large strains of 10–200%, but also small strains of 1–5%, making them promising candidates for wearable sensors to monitor large and subtle movements.     

水热离子交换时间对铯离子改型白榴石的影响

为实现对白榴石热膨胀系数的有效调控,利用铯离子对白榴石粉体进行改型。将白榴石粉体在浓度为0.3 mol/L的硫酸铯溶液中进行水热离子交换处理。利用X射线衍射仪（XRD）和扫描电子显微镜（SEM）对180 ℃下不同离子交换时间得到样品的物相和形貌进行了分析和观察。结果表明:铯离子进入白榴石晶格后,使部分白榴石转变生成了铯榴石,并且随着保温时间的延长,产物铯榴石晶体会逐渐由四方晶系过渡为立方晶系。当保温时间超过10 h时,两相间内应力增加会导致铯榴石从白榴石颗粒表面脱落,所以保温时间应该控制在2~10 h。利用JMA方程对合成铯榴石生长动力学过程进行拟合分析,从Avrami指数n小于0.5可知,整个反应主要由扩散控制。     

Relaxation of the mouse pubic symphysis during late pregnancy is not accompanied by the influx of granulocytes

In some animals, such as mice and guinea pigs, a hormonally controlled mechanism increases the flexibility of the pubic symphysis and enhances the cervical remodeling necessary for safe delivery. Cervical ripening during pregnancy is associated with a paradoxical influx of leukocytes. However, the changes in cell metabolism during relaxation of the mouse pubic symphysis for delivery have not been extensively studied. In this work, we used light microscopy and transmission and scanning electron microcopy, as well as immunohistochemistry and Western blotting for MMP-8, to investigate the involvement of granulocytes or resident stromal cells in the relaxation of the virgin pubic symphysis during late pregnancy (days 18 and 19, before delivery) in vivo and in explanted joints. MMP-8 was studied because this collagenase is a hallmark for cervical ripening associated with the influx of granulocytes during late pregnancy. Extensive dissolution and disorganization of the extracellular matrix was seen around fibroblastic-like cells in late pregnancy. In contrast to the cervix (positive control), morphological and immunohistochemical analyses revealed that there was no characteristic cellular inflammatory response in the interpubic tissue. Staining for MMP-8 was observed in chondroid and fibroblastic-like cells of virgin and relaxed interpubic ligament, respectively. However, no granulocytes were seen during the extensive remodeling of the pubic joint in late pregnancy. These results indicate that constitutive stromal cells may have an important role in tissue relaxation during remodeling of the pubic symphysis in pregnancy.     

集群风场系统链式SVG高频谐振分析与抑制

针对含链式静止无功发生器(static var generator, SVG)的风场区域系统高频谐振问题,首先采用谐波线性化的方法建立包含锁相环、功率外环以及电流内环在内的SVG谐波阻抗模型。利用阻抗分析法对风场区域空载线路投入对SVG稳定性的影响进行分析,揭示风场区域系统高频谐振的发生机理。然后,为抑制系统高频谐振,提出一种基于电压前馈附加带阻滤波器的SVG高频谐振抑制策略。对SVG侧中高频段等效阻抗进行重塑,以保证在该频段系统呈正阻尼状态。并讨论带阻滤波器中心频率和阻尼系数对系统相位裕度的影响。最后利用搭建的含链式SVG风场区域系统仿真模型,验证了理论分析的正确性和所提抑制策略的有效性。     

Fractional Order Nonlinear Bone Remodeling Dynamics Using the Supervised Neural Network

This study aims to solve the nonlinear fractional-order mathematical model (FOMM) by using the normal and dysregulated bone remodeling of the myeloma bone disease (MBD). For the more precise performance of the model, fractional-order derivatives have been used to solve the disease model numerically. The FOMM is preliminarily designed to focus on the critical interactions between bone resorption or osteoclasts (OC) and bone formation or osteoblasts (OB). The connections of OC and OB are represented by a nonlinear differential system based on the cellular components, which depict stable fluctuation in the usual bone case and unstable fluctuation through the MBD. Untreated myeloma causes by increasing the OC and reducing the osteoblasts, resulting in net bone waste the tumor growth. The solutions of the FOMM will be provided by using the stochastic framework based on the Levenberg-Marquardt backpropagation (LVMBP) neural networks (NN), i.e., LVMBPNN. The mathematical performances of three variations of the fractional-order derivative based on the nonlinear disease model using the LVMPNN. The static structural performances are 82% for investigation and 9% for both learning and certification. The performances of the LVMBPNN are authenticated by using the results of the Adams-Bashforth-Moulton mechanism. To accomplish the capability, steadiness, accuracy, and ability of the LVMBPNN, the performances of the error histograms (EHs), mean square error (MSE), recurrence, and state transitions (STs) will be provided.