The Xenopus Chk1 Protein Kinase Mediates a Caffeine-sensitive Pathway of Checkpoint Control in Cell-free Extracts

We have analyzed the role of the protein kinase Chk1 in checkpoint control by using cell-free extracts from Xenopus eggs. Recombinant Xenopus Chk1 (Xchk1) phosphorylates the mitotic inducer Cdc25 in vitro on multiple sites including Ser-287. The Xchk1-catalyzed phosphorylation of Cdc25 on Ser-287 is sufficient to confer the binding of 14-3-3 proteins. Egg extracts from which Xchk1 has been removed by immunodepletion are strongly but not totally compromised in their ability to undergo a cell cycle delay in response to the presence of unreplicated DNA. Cdc25 in Xchk1-depleted extracts remains bound to 14-3-3 due to the action of a distinct Ser-287-specific kinase in addition to Xchk1. Xchk1 is highly phosphorylated in the presence of unreplicated or damaged DNA, and this phosphorylation is abolished by caffeine, an agent which attenuates checkpoint control. The checkpoint response to unreplicated DNA in this system involves both caffeine-sensitive and caffeine-insensitive steps. Our results indicate that caffeine disrupts the checkpoint pathway containing Xchk1

Safety and efficacy of PDpoetin for management of anemia in patients with end stage renal disease on maintenance hemodialysis: Results from a phase IV clinical trial

Recombinant human erythropoietin (rHuEPO) is available for correcting anemia. PDpoetin, a new brand of rHuEPO, has been certified by Food and Drug Department of Ministry of Health and Medical Education of Iran for clinical use in patients with chronic kidney disease. We conducted this post-marketing survey to further evaluate the safety and efficacy of PDpoetin for management of anemia in patients on maintenance hemodialysis. Patients from 4 centers in Iran were enrolled for this multicenter, open-label, uncontrolled phase IV clinical trial. Changes in blood chemistry, hemoglobin and hematocrit levels, renal function, and other characteristics of the patients were recorded for 4 months; 501 of the patients recruited, completed this study. Mean age of the patients was 50.9 (±16.2) years. 48.7 of patients were female. Mean of the hemoglobin value in all of the 4 centers was 9.29 (±1.43) g/dL at beginning of the study and reached 10.96 (±2.23) g/dL after 4 months and showed significant increase overall (P<0.001). PDpoetin dose was stable at 50-100 U/kg thrice weekly. Hemorheologic disturbancesand changes in blood electrolytes was not observed. No case of immunological reactions to PDpoetin was observed. Our study, therefore, showed that PDpoetin has significantly raised the level of hemoglobin in the hemodialysis patients (about 1.7±0.6 g/dL). Anemia were successfully corrected in 49 of patients under study. Use of this biosimilar was shown to be safe and effective for the maintenance of hemoglobin in patients on maintenance hemodialysis. © A.N. Javidan et al., 2014

Improved sensitivity RF photonics doppler frequency measurement system

An improved sensitivity Doppler frequency measurement system based on microwave photonics technology was demonstrated practically. The system employs a four-wave mixing effect to achieve broad radio-frequency (RF) frequency measurement. In addition, a lock-in amplification technique was utilized to achieve high-measurement sensitivity. The system is, thus, capable of Doppler frequency estimation of radar echoes with a carrier frequency up to 40 GHz and a power level as low as $-$35 dBm. © 2009-2012 IEEE

Reduced cost photonic instantaneous frequency measurement system

A wideband photonic instantaneous frequency measurement system is proposed and practically demonstrated. This system employs only a low-frequency inexpensive photodetector and thus the system cost is reduced

Generating Diffusion MRI scalar maps from T1 weighted images using generative adversarial networks

Diffusion magnetic resonance imaging (diffusion MRI) is a non-invasive microstructure assessment technique. Scalar measures, such as FA (fractional anisotropy) and MD (mean diffusivity), quantifying micro-structural tissue properties can be obtained using diffusion models and data processing pipelines. However, it is costly and time consuming to collect high quality diffusion data. Here, we therefore demonstrate how Generative Adversarial Networks (GANs) can be used to generate synthetic diffusion scalar measures from structural T1-weighted images in a single optimized step. Specifically, we train the popular CycleGAN model to learn to map a T1 image to FA or MD, and vice versa. As an application, we show that synthetic FA images can be used as a target for non-linear registration, to correct for geometric distortions common in diffusion MRI

RF photonic instantaneous frequency measurement using DC photo-detection

A microwave photonic instantaneous frequency measurement (IFM) system based on a photonic transversal approach and DC-detection is proposed and practically demonstrated. This system is able to measure the RF frequency and power level independently

Quadrature hybrid coupler using photonic transversal approach

A novel technique to phase shift signal by 90° over a broad frequency range based on transversal signal processing is proposed and practically demonstrated. The proposed technique is suitable for non coherent optic implementation

Two output RF hybrid coupler using photonic transversal approach

A novel technique to implement a two output broad band RF hybrid coupler based on transversal signal processing is proposed and practically demonstrated. It features broadband frequency range, stable phase difference at outputs, 50 ohm input/output impedance, and low noise characteristics. This technique is suitable for non-coherent optic implementation

Amplitude independent RF instantaneous frequency measurement system using photonic Hilbert transform

A photonic instantaneous frequency measurement system capable of measuring both RF frequency and power simultaneously, is conceived and practically demonstrated. This system employs an RF photonic Hilbert transformer together with low-cost, low-frequency photo-detectors to obtain two orthogonal DC measurements. This system exhibits a frequency range of 1-10 GHz. Wider frequency range can be achieved through integration