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Millimeter-wave (mmWave) communication is used in high-throughput wireless networks. The shorter wavelength of mmWave requires the use of highly directional beamforming transmission techniques. However, transmission link degradation is significant with fast movement in the end user (EU) device. In this study, a rotational motion-aware beam refinement procedure (BRP) was proposed to maintain high-throughput data transmission during data transmission intervals (DTIs). Within the millisecond time frame of a DTI, the vulnerable rotational movement of the EU device can be detected using a three-axis orientation sensor (gyro). Therefore, the proposed BRP algorithm was employed at the EU device to switch the beam and thus achieve a proper line-of-sight. The process of beam switching is performed by directly detecting changes in the orientation of the EU device. The experimental results demonstrated that the proposed algorithm maintains high-throughput transmission under the fast movement of a EU device. The execution time of the BRP algorithm can be as low as 10 µs. Therefore, the overhead is solely the result of the sampling frequency of the motion sensors. The simulation results demonstrated that the use of our proposed algorithm improved the average received signal strength indicator by over 10 dBm. Furthermore, an average throughput of 928 Mbps is achieved with hardware testing, which is close to the maximum throughput of 970 Mbps for a low-power 60-GHz mmWave-embedded device. [ABSTRACT FROM AUTHOR]

The effects of the phosphorylation state of the glycogen synthase kinase 3β involved in the cardiac myocytes (jelly-like cells) epithelial-mesenchymal transition-associated migration during heart-valve formation were examined through the valproic acid-induced cardiac teratogenicity of transgenic line A34 of Tg in a the Brachydanio rerio embryo model. Valproic acid is an effective anti-epileptic drug; however, when taken by pregnant women to treat epilepsy, it can produce cardiac developmental defects in fetuses. In this study, the role of glycogen synthase kinase 3β in valproic acid-induced cardiac teratogenicity was investigated. Transgenic line A34 of zebrafish embryos was used at 3 days postfertilization. The results show that 78 % (18/23) of the embryos treated with 0.10 mM valproic acid (group A) had incomplete chamber formation with normal looping and 22 % (5/23) had abnormal looping. Bradycardia was also found in comparison with control embryos ( P < 0.001). For the embryos treated with 0.25 mM valproic acid (group B), 92 % (22/24) demonstrated chamber formation failure and looping abnormality. Pericardial effusion, noncontracting ventricles, and enlarged, slowly beating atriums were observed at 6 days postfertilization. Valproic acid inhibited phosphorylation of serine 9 in glycogen synthase kinase 3β in a dose-dependent manner. According to immunochemical staining results, valproic acid was shown to inhibit the mass migration and proliferation of cardiomyocytes in the development of the heart-valve region through inhibition of the GSK3β Ser 9 phosphorylation. Folic acid rescued the GSK3β Ser 9 phosphorylation and reversed the valproic acid-induced cardiac morphological, functional, and biochemical defects. [ABSTRACT FROM AUTHOR]

We present a new double-sided, single-chip monolithic integration scheme to integrate the CMOS circuits and MEMS structures by using through-silicon-via (TSV). Neural sensing applications were chosen as the implementation example. The proposed heterogeneous device integrates standard 0.18 μm CMOS technology, TSV and neural probe array into a compact single chip device. The neural probe array on the back-side of the chip is connected to the CMOS circuits on the front-side of the chip by using low-parasitic TSVs through the chip. Successful fabrication results and detailed characterization demonstrate the feasibility and performance of the neural probe array, TSV and readout circuitry. The fabricated device is 5 × 5 mm in area, with 16 channels of 150 μm-in-length neural probe array on the back-side, 200 μm-deep TSV through the chip and CMOS circuits on the front-side. Each channel consists of a 5 × 6 probe array, 3 × 14 TSV array and a differential-difference amplifier (DDA) based analog front-end circuitry with 1.8 V supply, 21.88 μW power consumption, 108 dB CMRR and 2.56 μVrms input referred noise. In-vivo long term implantation demonstrated the feasibility of presented integration scheme after 7 and 58 days of implantation. We expect the conceptual realization can be extended for higher density recording array by using the proposed method. [ABSTRACT FROM AUTHOR]

The protein kinase C (PKC) pathway is important for the regulation of K transport. The renal outer medullar K (ROMK1) channels show an exquisite sensitivity to intracellular protons (pH) (effective p K approximately 6.8) and play a key role in K homeostasis during metabolic acidosis. Our molecular dynamic simulation results suggest that PKC-mediated phosphorylation on Thr-193 may disrupt the PIP-channel interaction via a charge-charge interaction between Thr-193 and Arg-188. Therefore, we investigated the role of PKC and pH in regulation of ROMK1 channel activity using a giant patch clamp with Xenopus oocytes expressing wild-type and mutant ROMK1 channels. ROMK1 channels pre-incubated with the PKC activator phorbol-12-myristate-13-acetate exhibited increased sensitivity to pH (effective p K shifted to pH approximately 7.0). In the presence of GF109203X-a PKC selective inhibitor-the effective p K for inhibition of ROMK1 channels by pH decreased (effective p K shifted to pH approximately 6.5). The pH sensitivity of ROMK1 channels mediated by PKC appeared to be dependent of PIP depletion. The giant patch clamp together with site direct mutagenesis revealed that Thr-193 is the phosphorylation site on PKC that regulates the pH sensitivity of ROMK1 channels. Mutation of PKC-induced phosphorylation sites (T193A) decreases the pH sensitivity and increases the interaction of channel-PIP. Taken together, these results provide new insights into the molecular mechanisms underlying the pH gating of ROMK1 channel regulation by PKC. [ABSTRACT FROM AUTHOR]

Rundown is a generally encountered problem while recording KATP channel activity with inside-out patches. No assigned structural fragment related to this mechanism has yet been derived from any of the functional analyses performed. Therefore, based on a combined sequence and secondary structure alignment against known crystal structure of segments from closely related proteins, we propose here the three-dimensional structural model of an intracellular C-terminal domain of the Kir6.2 subunit in KATP channels. An E. coli CMP-kinase was suggested as template for the model building. The subdomain arrangement of this novel kinase domain and the structural correlation for UDP-docking are described. With structural-functional interpretation, we conclude that the reactivation of KATP channel rundown by MgATP or UDP is very possibly regulated by this intracellular kinase domain at the C-terminus of Kir6.2 subunit in KATP channels. [ABSTRACT FROM AUTHOR]

Helicobacter pylori infection is associated with the development of gastric and duodenal ulcers as well as gastric cancer. GroES of H. pylori (HpGroES) was previously identified as a gastric cancer-associated virulence factor. Our group showed that HpGroES induces interleukin-8 (IL-8) cytokine release via a Toll-like receptor 4 (TLR4)-dependent mechanism and domain B of the protein is crucial for interactions with TLR4. In the present study, we investigated the importance of the histidine residues in domain B. To this end, a series of point mutants were expressed in Escherichia coli, and the corresponding proteins purified. Interestingly, H96, H104 and H115 were not essential, whereas H100, H102, H108, H113 and H118 were crucial for IL-8 production and TLR4 interactions in KATO-III cells. These residues were involved in nickel binding. Four of five residues, H102, H108, H113 and H118 induced certain conformation changes in extended domain B structure, which is essential for interactions with TLR4 and consequent IL-8 production. We conclude that interactions of nickel ions with histidine residues in domain B help to maintain the conformation of the C-terminal region to conserve the integrity of the HpGroES structure and modulate IL-8 release. [ABSTRACT FROM AUTHOR]