Optical backplane system using waveguide-embedded PCBs and optical slots

As discussed in this paper, a practical optical backplane system was demonstrated, using a waveguide-embedded optical backplane board, processing boards, and optical slots for board-to-board interconnection. A metal optical bench was used as a packaging die for the optical devices and the integrated circuit chips in both the transmitter and the receiver processing boards. The polymer waveguide was produced by means of a hot-embossing technique and was then embedded following a conventional lamination processes. The average propagation loss of these waveguides was approximately 0.1 dB/cm at 850 nm. The dimension and optical properties of the waveguide in an optical backplane board were unchanged after lamination. As connection components between transmitter/receiver processing boards and an optical backplane board, optical slots were used for easy and repeatable insertion and extraction of the boards with a micrometer-scale precision. A 1/spl times/4 850-nm vertical-cavity surface-emitting laser array was used with 2 dBm of output power for the transmitter and a p-i-n photodiode array for the receiver. This paper successfully demonstrates 8 Gb/s of data transmission between the transmitter processing board and the optical backplane board.     

Design of Rate-Compatible Block Turbo Code with a Low-Degree Generating Polynomial

This paper presents a Rate-Compatible Block Turbo Code (RC-BTC) with increased transmission capacity. The proposed RC-BTC uses a new algorithm called information augmenting scheme, and can achieve a higher code rate than conventional one. A new Error Location Finding (ELF) Decoding Algorithm is introduced to solve the decoding problem of the information augmenting scheme. As a result, a novel error-correcting capability of the BTC-applied Chase-ELF Hybrid Decoder, combining the previous Chase–Pyndiah algorithm and the proposed ELF algorithm, is demonstrated via Monte-Carlo simulation. In addition, the proposed code maximally increases the transmission capacity with the Chase-ELF Hybrid decoder using an information augmenting scheme.     

High-density inductively coupled plasma chemical vapor deposition of silicon nitride for solar cell application

The silicon nitride films were deposited by means of high-density inductively coupled plasma chemical vapor deposition in a planar coil reactor. The process gases used were pure nitrogen and a mixture of silane and helium. Passivated by silicon nitride, solar cells show efficiency above 13%. Strong H-atom release from the growing SiN film and Si–N bond healing are responsible for the improved electrical and passivation properties of SiN film. This paper presents the optimal refractive index of SiN for single layer antireflection coating as well as double layer antireflection coating in solar cell applications.     

Metallic nanowire-graphene hybrid nanostructures for highly flexible field emission devices

We report a simple but efficient method to prepare metallic nanowire-graphene (MN-G) hybrid nanostructures at a low temperature and show its application to the fabrication of flexible field emission devices. In this method, a graphene layer was transferred onto an anodic alumina oxide template, and vertically aligned Au nanowires were grown on the graphene surface via electrodeposition method. As a proof of concept, we demonstrated the fabrication of flexible field emission devices, where the MN-G hybrid nanostructures and another graphene layer on PDMS substrates were utilized as a cathode and an anode for highly flexible devices, respectively. Our field emission device exhibited stable and high field emission currents even when bent down to the radius of curvature of 25 mm. This MN-G hybrid nanostructure should prove tremendous flexibility for various applications such as bio-chemical sensors, field emission devices, pressure sensors and battery electrodes.     

Host-guest chemistry in the gas phase: selected fragmentations of CB[6]-peptide complexes at lysine residues and its utility to probe the structures of small proteins

The gas phase host-guest chemistry between cucurbit[6]uril (CB[6]) and peptide is investigated using electrospray ionization mass spectrometry (ESI-MS). CB[6] exhibits a high preference to interacting with a Lys residue in a peptide forming a CB[6]-peptide complex. Collisionally activated CB[6] complexes of peptides yield a common highly selective fragment product at m/z 549.2, corresponding to the doubly charged CB[6] complex of 5-iminiopentylammonium (5IPA). The process involves the formation of an internal iminium ion, which results from further fragments to an a-type ion from a y-type ion, and the resulting 5IPA ion threads through CB[6]. Numerous peptides are investigated to test the generality of the observed unique host-guest chemistry of CB[6]. Its potential utility in probing protein structures is demonstrated using CB[6] complexes of ubiquitin. Low-energy collision induced dissociation yields CB[6] complex fragments, and further MS(n) spectra reveal details of the CB[6] binding sites, which allow us to deduce the protein structure in the solution phase. The mechanisms and energetics of the observed reactions are evaluated using density functional theory calculations.     

Fast release process of metal structure using chemical dry etching of sacrificial Si layer

An ultra-fast removal process of a silicon sacrificial layer for the selective release of a metal structure on a Si substrate was studied, which uses a chemical dry etching method. The chemical dry etching of a Si layer was performed in an NF₃ remote plasma with the direct injection of additive nitric oxide (NO) gas. When the NO gas was injected into the chamber into which F radicals were supplied from a remote plasma source using NF₃ input gas, the silicon layer was removed selectively and the metal structure could be released easily. It was found that the etch rate on the sidewall (up to ≅ 18.7 μm/min for an opening width of 100 μm) and the bottom (up to ≅ 24.5 μm/min for an opening width of 100 μm) depends on the NO/(NO + Ar) gas flow ratio, time duration, and opening width. The developed dry etching process could be used to release a Ni structure with near infinite selectivity in a very short time. The process is well suited for fabricating various devices which require a suspended structure, such as in radio-frequency microelectromechanical system switches, tunable capacitors, high-Q suspended inductors and suspended-gate metal-oxide semiconductor field-effect transistors.     

Weakly Binding Molecules-Based Fast Charging Li-Ion Batteries

Fast charging of Li-ion batteries (LIBs) beyond standard 0.3 C (charged in 3.3 h) are desperately pursued but hindered by sluggish desolvation kinetics of ethylene carbonate-based traditional electrolyte, and Li-plating and dendrites growth at graphite anode and fire hazard. Herein, a new class of weakly binding all linear molecules-based nonflammable electrolyte (WNLE) is reported, comprising 1 m LiPF₆ in ethyl methyl carbonate and 2,2,2-trifluoroethyl acetate with additives for 10–20 times faster charging LIBs than traditional ones. The critical benefits of WNLE are 44% lower viscosity, 62% higher Li⁺ diffusion coefficient, 20% higher Li⁺ transference number, and 17% lower desolvation energy, which promotes diffusion kinetics and desolvation kinetics of Li⁺ in the vicinity of graphite anode enabling dendrites-free LIB, along with nonflammability. Under 3 C (charged in 20 min), WNLE-based industrial 800 mAh graphite//LiNi_0.8Mn_0.1Co_0.1O₂ (high active mass 13 mg cm⁻²) Li-ion pouch battery achieves outstanding 700 cycles, delivering 82% capacity retention and high Coulombic efficiencies ≈100%. Robust solid electrolyte interphase layers formed at the anode and cathode mitigate interfacial failures, making fast charge to 7 C and longer cycle-life. This new class of electrolyte formulation is a promising solution and a new opportunity to realize safe and long operation of fast-charging LIBs for practical applications.     

Berbamine Reduces Chloroquine-Induced Itch in Mice through Inhibition of MrgprX1

Chloroquine (CQ) is an antimalaria drug that has been widely used for decades. However, CQ-induced pruritus remains one of the major obstacles in CQ treatment for uncomplicated malaria. Recent studies have revealed that MrgprX1 plays an essential role in CQ-induced itch. To date, a few MrgprX1 antagonists have been discovered, but they are clinically unavailable or lack selectivity. Here, a cell-based high-throughput screening was performed to identify novel antagonists of MrgprX1, and the screening of 2543 compounds revealed two novel MrgprX1 inhibitors, berbamine and closantel. Notably, berbamine potently inhibited CQ-mediated MrgprX1 activation (IC₅₀ = 1.6 μM) but did not alter the activity of other pruritogenic GPCRs. In addition, berbamine suppressed the CQ-mediated phosphorylation of ERK1/2. Interestingly, CQ-induced pruritus was significantly reduced by berbamine in a dose-dependent manner, but berbamine had no effect on histamine-induced, protease-activated receptors 2-activating peptide-induced, and deoxycholic acid-induced itch in mice. These results suggest that berbamine is a novel, potent, and selective antagonist of MrgprX1 and may be a potential drug candidate for the development of therapeutic agents to treat CQ-induced pruritus.