On The Rate and Extent of Drug Delivery to the Brain

To define and differentiate relevant aspects of blood–brain barrier transport and distribution in order to aid research methodology in brain drug delivery. Pharmacokinetic parameters relative to the rate and extent of brain drug delivery are described and illustrated with relevant data, with special emphasis on the unbound, pharmacologically active drug molecule. Drug delivery to the brain can be comprehensively described using three parameters: Kp,uu (concentration ratio of unbound drug in brain to blood), CLin (permeability clearance into the brain), and Vu,brain (intra-brain distribution). The permeability of the blood–brain barrier is less relevant to drug action within the CNS than the extent of drug delivery, as most drugs are administered on a continuous (repeated) basis. Kp,uu can differ between CNS-active drugs by a factor of up to 150-fold. This range is much smaller than that for log BB ratios (Kp), which can differ by up to at least 2,000-fold, or for BBB permeabilities, which span an even larger range (up to at least 20,000-fold difference). Methods that measure the three parameters Kp,uu, CLin, and Vu,brain can give clinically valuable estimates of brain drug delivery in early drug discovery programmes

The state of the art in beyond 5G distributed massive multiple-input multiple-output communication system solutions

<p>Beyond fifth generation (5G) communication systems aim towards data rates in the tera bits per second range, with improved and flexible coverage options, introducing many new technological challenges in the fields of network architecture, signal pro- cessing, and radio frequency front-ends. One option is to move towards cell-free, or distributed massive Multiple-Input Multiple-Output (MIMO) network architectures and highly integrated front-end solutions. This paper presents an outlook on be- yond 5G distributed massive MIMO communication systems, the signal processing, characterisation and simulation challenges, and an overview of the state of the art in millimetre wave antennas and electronics.</p&gt

Atmospheric Short-Chain Chlorinated Paraffins in China, Japan, and South Korea

This study presents the first investigation of concentrations and congener group patterns of atmospheric short-chain chlorinated paraffins (SCCPs) throughout East Asia. Based on an absorption rate calibration experiment, a spatial survey of SCCPs was performed using passive air samplers in China, Japan, and South Korea during two separate periods in 2008. The atmospheric concentrations of SCCPs in China were clearly greater than those in Japan and South Korea, both of which exceed the levels determined for other regions of the world. C-10 components were the most abundant type of SCCPs in China, whereas C-11 components were dominant in Japan and South Korea. With respect to the total chlorine content, Cl-6 and Cl-5 were the predominant compounds in China and Japan; however, Cl-6 and Cl-7 were predominant in South Korea. A similar pattern was also found for remote sites within China, Japan, and South Korea, respectively. Together with the back-trajectories calculated for the remote sites, the results indicate that the SCCPs in the air of East Asia were mainly influenced by local sources due to their relatively low long-range atmospheric transport potential compared to other POPs.This study presents the first investigation of concentrations and congener group patterns of atmospheric short-chain chlorinated paraffins (SCCPs) throughout East Asia. Based on an absorption rate calibration experiment, a spatial survey of SCCPs was performed using passive air samplers in China, Japan, and South Korea during two separate periods in 2008. The atmospheric concentrations of SCCPs in China were clearly greater than those in Japan and South Korea, both of which exceed the levels determined for other regions of the world. C-10 components were the most abundant type of SCCPs in China, whereas C-11 components were dominant in Japan and South Korea. With respect to the total chlorine content, Cl-6 and Cl-5 were the predominant compounds in China and Japan; however, Cl-6 and Cl-7 were predominant in South Korea. A similar pattern was also found for remote sites within China, Japan, and South Korea, respectively. Together with the back-trajectories calculated for the remote sites, the results indicate that the SCCPs in the air of East Asia were mainly influenced by local sources due to their relatively low long-range atmospheric transport potential compared to other POPs