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A novel three dimensional blood brain barrier (BBB) platform was developed by independently supplying different types of media to separate cell types within a single device. One channel (vascular channel, VC) is connected to the inner lumen of the vascular network while the other supplies media to the neural cells (neural channel, NC). Compared to co-cultures supplied with only one type of medium (or 1:1 mixture), best barrier properties and viability were obtained with culturing HUVECs with endothelial growth medium (EGM) and neural cells with neurobasal medium supplemented with fetal bovine serum (NBMFBS) independently. The measured vascular network permeability were comparable to reported in vivo values (20 kDa FITC-dextran, 0.45 ± 0.11 × 10 −6  cm/s; 70 kDa FITC-dextran, 0.36 ± 0.05 × 10 −6  cm/s) and a higher degree of neurovascular interfacing (astrocytic contact with the vascular network, GFAP-CD31 stain overlap) and presence of synapses (stained with synaptophysin). The BBB platform can dependably imitate the perivascular network morphology and synaptic structures characteristic of the NVU. This microfluidic BBB model can find applications in screening pharmaceuticals that target the brain for in neurodegenerative diseases.

In this paper, a winding inter-turn fault (ITF) diagnosis algorithm for electrical machines in integrated motor and drive (IMD) systems is proposed based on impedance analysis using space voltage vectors. An ITF alters the stator resistance, causing an imbalance in the motor’s impedance depending on the phase connection. This impedance asymmetry can be effectively utilized for fault diagnosis. However, in IMD systems, direct impedance measurement through mechanical terminal access is difficult due to the integrated structure. To address this, the impedance of the induction motor is analyzed electrically, without the need for physical disconnection, allowing practical implementation within integrated systems. The specific phase angle of the space voltage vector in the three-phase inverter is analyzed to replicate the electrical conditions of mechanical terminal configurations. Based on this approach, a fault diagnosis algorithm was developed by analyzing the variation in stator current and impedance with respect to space voltage vector angles. The effectiveness of the proposed method was verified through experimental validation using a 12kW three-phase induction motor and terminal box.

Successful pregnancy inevitably depends on the implantation of a competent embryo into a receptive endometrium. Although many substances have been suggested to improve the rate of embryo implantation targeting enhancement of endometrial receptivity, currently there rarely are effective evidence-based treatments to prevent or cure this condition. Here we strongly suggest minimally-invasive intra-uterine administration of embryo-secreted chemokine CXCL12 as an effective therapeutic intervention. Chemokine CXCL12 derived from pre- and peri-implanting embryos significantly enhances the rates of embryo attachment and promoted endothelial vessel formation and sprouting in vitro. Consistently, intra-uterine CXCL12 administration in C57BL/6 mice improved endometrial receptivity showing increased integrin β3 and its ligand osteopontin, and induced endometrial angiogenesis displaying increased numbers of vessel formation near the lining of endometrial epithelial layer with higher CD31 and CD34 expression. Furthermore, intra-uterine CXCL12 application dramatically promoted the rates of embryo implantation with no morphologically retarded embryos. Thus, our present study provides a novel evidence that improved uterine endometrial receptivity and enhanced angiogenesis induced by embryo-derived chemokine CXCL12 may aid to develop a minimally-invasive therapeutic strategy for clinical treatment or supplement for the patients with repeated implantation failure with less risk.

Endometrial receptivity is a critical determinant of embryo implantation and early pregnancy success; however, current methods for assessing endometrial receptivity remain poorly validated and insufficiently reliable for clinical application. Here, we establish a patient-derived vascularised endometrium-on-a-chip (EoC), successfully replicating the dynamic microenvironment and both temporal and spatial architecture of native endometrial tissue. Using our EoC, we develop a clinically relevant endometrial receptivity scoring system, ERS 2 , which integrates molecular profiling of established receptivity markers with quantitative analyses of angiogenesis. The ERS 2 enables personalised assessment of endometrial health and implantation potential, addressing inter-patient variability often overlooked by conventional techniques. By leveraging our EoC to therapeutic monitoring, we observe progressive restoration of the endometrial microenvironment following platelet-rich-plasma treatments, highlighting the translational utility of our model. This study represents the innovative application of a patient-derived EoC and scoring system to assess receptivity, offering personalised infertility management and advancing targeted therapies in reproductive medicine. Accurate assessment of endometrial receptivity remains a challenge in infertility care. Here, authors present a patient-derived vascularised endometrium-on-a-chip and a scoring system for receptivity evaluation.

Bone is one of the most common sites of cancer metastasis, as its fertile microenvironment attracts tumor cells. The unique mechanical properties of bone extracellular matrix (ECM), mainly composed of hydroxyapatite (HA) affect a number of cellular responses in the tumor microenvironment (TME) such as proliferation, migration, viability, and morphology, as well as angiogenic activity, which is related to bone metastasis. In this study, we engineered a bone-mimetic microenvironment to investigate the interactions between the TME and HA using a microfluidic platform designed for culturing tumor cells in 3D bone-mimetic composite of HA and fibrin. We developed a bone metastasis TME model from colorectal cancer (SW620) and gastric cancer (MKN74) cells, which has very poor prognosis but rarely been investigated. The microfluidic platform enabled straightforward formation of 3D TME composed the hydrogel and multiple cell types. This facilitated monitoring of the effect of HA concentration and culture time on the TME. In 3D bone mimicking culture, we found that HA rich microenvironment affects cell viability, proliferation and cancer cell cytoplasmic volume in a manner dependent on the different metastatic cancer cell types and culture duration indicating the spatial heterogeneity (different origin of metastatic cancer) and temporal heterogeneity (growth time of cancer) of TME. We also found that both SW620 and MKN72 cells exhibited significantly reduced migration at higher HA concentration in our platform indicating inhibitory effect of HA in both cancer cells migration. Next, we quantitatively analyzed angiogenic sprouts induced by paracrine factors that secreted by TME and showed paracrine signals from tumor and stromal cell with a high HA concentration resulted in the formation of fewer sprouts. Finally we reconstituted vascularized TME allowing direct interaction between angiogenic sprouts and tumor-stroma microspheroids in a bone-mimicking microenvironment composing a tunable HA/fibrin composite. Our multifarious approach could be applied to drug screening and mechanistic studies of the metastasis, growth, and progression of bone tumors.

The time-of-flight (ToF) principle is a method used to measure distance and construct three-dimensional (3D) images by detecting the time or the phase difference between emitted and back-reflected optical flux. The ToF principle has been employed for various applications including light ranging and detection (LiDAR), machine vision and biomedical engineering; however, bulky system size and slow switching speed have hindered the widespread application of ToF technology. To alleviate these issues, a demonstration of hetero-integration of GaN-based high electron mobility transistors (HEMTs) and GaAs-based vertical cavity surface emitting lasers (VCSELs) on a single platform via a cold-welding method was performed. The hetero-integrated ToF sensors show superior switching performance when compared to silicon-transistor-based systems, miniaturizing size and exhibiting stable ranging and high-resolution depth-imaging. This hetero-integrated system of dissimilar material-based high-performance devices suggests a new pathway towards enabling high-resolution 3D imaging and inspires broader range application of heterogeneously integrated electronics and optoelectronics.

Tumors develop in intricate microenvironments required for their sustained growth, invasion, and metastasis. The tumor microenvironment plays a critical role in the malignant or drug resistant nature of tumors, becoming a promising therapeutic target. Microengineered physiological systems capable of mimicking tumor environments are one emerging platform that allows for quantitative and reproducible characterization of tumor responses with pathophysiological relevance. This review highlights the recent advancements of engineered tumor microenvironment systems that enable the unprecedented mechanistic examination of cancer progression and metastasis. We discuss the progress and future perspective of these microengineered biomimetic approaches for anticancer drug prescreening applications.

In this paper, the design of novel slotless permanent magnet synchronous motor (PMSM) for a collaborative robot was studied considering the manufacture process of winding. The winding manufacture process of novel slotless PMSM was proposed in three steps. First, the two types of coil units were manufactured based on the winding jig to assemble the coil units. Second, the coil unit was manufactured using the injection molding based on the plastic material such as polyphenylene sulfide (PPS). Third, the units of the coil were assembled to form a stator winding. Considering this manufacture process of winding, the slotless motor design was studied for the collaborative robot. For the design and analysis of slotless motor, finite element analysis (FEA) was performed through ANSYS Maxwell. The electromagnetic performance was analyzed according to the pole-slot combination. Considering the space of the collaborative robot, the basic model was designed. Based on the basic model, the electromagnetic performance was analyzed according to the design parameters such as the thickness of magnet and yoke and turns per slot. Considering the torque and current density, the final model was designed. To verify the FEA results, the slotless motor was manufactured and the experiment and FEA results were compared.

Hypoxia in the tumor microenvironment (TME) is the leading cause of metastasis and chemoresistance in cancer cells. Numerous 3D in vitro models have been proposed to study hypoxic stress, but none have enabled sufficient analysis of hepatocellular carcinoma (HCC). Herein, a 3D in vitro tumor vasculature model for HCC is introduced to investigate cellular responses and drug resistance under hypoxic conditions through high‐content screening. The hypoxic TME of vascularized HCC can be established by maintaining the platform in a hypoxia chamber and is used to analyze the diverse physiological responses of the TME to normoxia, hypoxia, and drug treatment. The proposed platform also demonstrates the hypoxic status naturally induced by 3D HCC spheroids for comparison with single HCC cells cultured in the hypoxia chamber. The results show that hypoxic stress in the HCC vasculature promotes angiogenesis, hypoxia‐inducible factor 1 (HIF‐1) expression, and proliferation; it also enhances drug resistance. The hypoxic tumor vasculature of the model generates cellular responses that are also expressed in the physiological hypoxic microenvironment of HCC. These findings suggest that our high‐content microfluidic platform can be applied as a powerful tool to develop anticancer therapeutics, which have remained elusive because of hypoxia in the TME. The low oxygen environment in vivo, hypoxia leads to enhanced tumor progression and drug resistance in cancer cells. This in vitro injection‐molded platform reconstitutes hepatocellular carcinoma under low oxygen conditions and provides insight into the effects of hypoxia. The formation of new blood vessels and cancer cell proliferation as well as increased chemoresistance are highlighted.

In vivo, blood vessels constitutively experience mechanical stresses exerted by adjacent tissues and other structural elements. Vascular collapse, a structural failure of vascular tissues, may stem from any number of possible compressive forces ranging from injury to tumor growth and can promote inflammation. In particular, endothelial cells are continuously exposed to varying mechanical stimuli, internally and externally, resulting in blood vessel deformation and injury. This study proposed a method to model biomechanical-stimuli-induced blood vessel compression in vitro within a polydimethylsiloxane (PDMS) microfluidic 3D microvascular tissue culture platform with an integrated pneumatically actuated compression mechanism. 3D microvascular tissues were cultured within the device. Histological reactions to compressive forces were quantified and shown to be the following: live/dead assays indicated the presence of a microvascular dead zone within high-stress regions and reactive oxygen species (ROS) quantification exhibited a stress-dependent increase. Fluorescein isothiocyanate (FITC)-dextran flow assays showed that compressed vessels developed structural failures and increased leakiness; finite element analysis (FEA) corroborated the experimental data, indicating that the suggested model of vascular tissue deformation and stress distribution was conceptually sound. As such, this study provides a powerful and accessible in vitro method of modeling microphysiological reactions of microvascular tissues to compressive stress, paving the way for further studies into vascular failure as a result of external stress.