Removable silicon insertion stiffeners for neural probes using polyethylene glycol as a biodissolvable adhesive

Abstract not provide

Cooperative epithelial phagocytosis enables error correction in the early embryo

Errors in early embryogenesis are a cause of sporadic cell death and developmental failure1,2. Phagocytic activity has a central role in scavenging apoptotic cells in differentiated tissues3-6. However, how apoptotic cells are cleared in the blastula embryo in the absence of specialized immune cells remains unknown. Here we show that the surface epithelium of zebrafish and mouse embryos, which is the first tissue formed during vertebrate development, performs efficient phagocytic clearance of apoptotic cells through phosphatidylserine-mediated target recognition. Quantitative four-dimensional in vivo imaging analyses reveal a collective epithelial clearance mechanism that is based on mechanical cooperation by two types of Rac1-dependent basal epithelial protrusions. The first type of protrusion, phagocytic cups, mediates apoptotic target uptake. The second, a previously undescribed type of fast and extended actin-based protrusion that we call 'epithelial arms', promotes the rapid dispersal of apoptotic targets through Arp2/3-dependent mechanical pushing. On the basis of experimental data and modelling, we show that mechanical load-sharing enables the long-range cooperative uptake of apoptotic cells by multiple epithelial cells. This optimizes the efficiency of tissue clearance by extending the limited spatial exploration range and local uptake capacity of non-motile epithelial cells. Our findings show that epithelial tissue clearance facilitates error correction that is relevant to the developmental robustness and survival of the embryo, revealing the presence of an innate immune function in the earliest stages of embryonic development

Simulation of pulse width modulation using Tinkercard

Este trabajo tiene como finalidad usar la plata-forma Tinkercard para comprender los conceptos de la señal PWM (modulación por ancho de pulso). Dicha plataforma nos permite crear una simulación don se pueda observar fácil-mente términos como el DutyCycle (ciclo de trabajo), el periodo de la señal, la frecuencia de la señal, el tiempo de encendido de la señal, el tiempo de apagado de la señal, entro otras ter-minologías que se deben tener en cuenta al hacer uso de esta modulación por ancho de pulso. La ventaja más importante del uso de tinkercard es su facilidad de uso y su accesibilidad ya que es gratuita y muy intuitiva, así cualquier persona puede usarla sin previo conocimiento sobre ella

HIGH-DENSITY, BIO-COMPATIBLE, AND HERMETIC ELECTRICAL FEEDTHROUGHS USING EXTRUDED METAL VIAS

Implanted medical devices such as pacemakers and neural prosthetics require that the electronic components that power these devices are protected from the harsh chemical and biological environment of the body. Typically, the electronics are hermetically sealed inside a bio-compatible package containing feedthroughs that transmit electrical signals, while being impermeable to particles or moisture. We present a novel approach for fabricating one of the highest densities of biocompatible hermetic feedthroughs in alumina (Al{sub 2}O{sub 3}). Alumina substrates with laser machined vias of 200 {micro}m pitch were conformally metallized and lithographically patterned. Hermetic electrical feedthroughs were formed by extruding metal stud-bumps partially through the vias. Hermeticity testing showed leak rates better than 9 x 10{sup -10} torr-l/s. Based on our preliminary results and process optimization, this extruded metal via approach is a high-density, low temperature, cost-effective, and robust method of miniaturizing electrical feedthroughs for a wide range of implantable bio-medical device applications

Reglamento y ordenanza de su Magestad de seis de diziembre de mil setecientos y diez y ocho, sobre el comercio de las islas de Canaria, Tenerife, y La Palma en las Indias

Texto firmado por Miguel Fernández DuránTexto fechado en el Pardo a 6 de diciembre de 1718Sign.: [ ]1, A6Texto con apostillas marginale