A microfluidic system for studying ageing and dynamic single-cell responses in budding yeast

Recognition of the importance of cell-to-cell variability in cellular decision-making and a growing interest in stochastic modeling of cellular processes has led to an increased demand for high density, reproducible, single-cell measurements in time-varying surroundings. We present ALCATRAS (A Long-term Culturing And TRApping System), a microfluidic device that can quantitatively monitor up to 1000 cells of budding yeast in a well-defined and controlled environment. Daughter cells are removed by fluid flow to avoid crowding allowing experiments to run for over 60 hours, and the extracellular media may be changed repeatedly and in seconds. We illustrate use of the device by measuring ageing through replicative life span curves, following the dynamics of the cell cycle, and examining history-dependent behaviour in the general stress response

Fabrication of thick silicon dioxide layers for thermal isolation

This paper reports a method of fabricating very thick (10–100 µm) silicon dioxide layers for thermal isolation without the need for very long deposition or oxidation. Deep reactive ion etching (DRIE) is used to create high-aspect-ratio trenches and silicon pillars, which are then oxidized and/or refilled with LPCVD oxide to create oxide layers as thick as the DRIE allows. Stiffeners are used to provide support for the pillars during oxidation. Thermal tests show that such thick silicon dioxide layers can effectively thermally isolate heated structures from neighboring structures within a distance of hundreds of microns. The thermal conductivity of the thick SiO2 is measured to be ∼1.1 W (m K)−1. Such SiO2 diaphragms of thickness 50–60 µm can sustain an extrinsic shear stress up to 3–5 MPa.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49045/2/jmm4_6_002.pd

Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo

Meeting Abstracts: Proceedings of the Thirteenth International Society of Sports Nutrition (ISSN) Conference and Expo Clearwater Beach, FL, USA. 9-11 June 201

Cyclist safety at road works

SIGLEAvailable from British Library Document Supply Centre-DSC:9050.78239(370) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Forecasting continuous carbon nanotube production in the floating catalyst environment

We pre­sent val­i­dated sta­tis­ti­cal mod­els and uni­vari­ate cor­re­la­tions of car­bon nan­otube (CNT) tex­tile prop­er­ties (spe­cific elec­tri­cal con­duc­tiv­ity, Ra­man G:D ra­tio and mass yield rate) ex­tracted con­tin­u­ously from float­ing cat­a­lyst chem­i­cal vapour de­po­si­tion (FC-CVD) re­ac­tors over a uniquely wide mul­ti­vari­ate ex­per­i­men­tal space. This in­cludes di­rectly con­trolled re­ac­tor set­tings (e.g. pre­cur­sor con­cen­tra­tions, gas flow rates, fur­nace tem­per­a­tures and wind­ing speeds), in­di­rect pa­ra­me­ters (e.g. am­bi­ent tem­per­a­ture and pres­sure), and time-de­pen­dent re­ac­tor in­flu­ences such as re­ac­tor tube age. Two ver­ti­cal FC-CVD re­ac­tors, with dif­fer­ent pre­cur­sor de­liv­ery ar­chi­tec­tures, were con­sid­ered: 1) in which pre­cur­sors were pre-mixed to­gether as a liq­uid so­lu­tion that was di­rectly in­jected into re­ac­tor; 2) in which va­por­ised pre­cur­sors were in­de­pen­dently in­jected in the gas phase us­ing Cori­o­lis-based mi­croflu­idic mass flow con­trollers with con­cen­tra­tions mon­i­tored in-line us­ing FTIR spec­troscopy. Fac­tors favour­ing high­est elec­tri­cal con­duc­tiv­ity fi­bres in­clude: lower hy­dro­gen flows, lean fuel-to-gas mix­tures, higher wind­ing rates, higher ar­gon flows, with many thio­phene con­cen­tra­tion in­ter­ac­tions with other pa­ra­me­ters; for high­est Ra­man G:D ra­tios: leaner fuel-to-gas mix­tures, lower thio­phene con­cen­tra­tions, higher hy­dro­gen flows, and greater ex­ter­nal lab­o­ra­tory pres­sure; but for yield rate, sys­tem­atic trends were harder to dis­cern. This study demon­strates the de­gree of pre­dictabil­ity in FC-CVD re­ac­tors, quan­ti­ta­tively ranks im­pact of FC-CVD pa­ra­me­ters, and iden­ti­fies re­gions of fi­bre “spinnabil­ity” which cor­re­spond well with a re­cent meta-analy­sis of ex­per­i­men­tal re­sults in the lit­er­a­ture