5,5′-Di-4-pyridyl-2,2′-(5-tert-butyl-m-phenyl­ene)bis­(1,3,4-oxadiazole)

The title compound, C24H20N6O2, is a novel 1,3,4-oxadiazole derivative which has potential as an electron-transporting material in organic electroluminescent (EL) devices. In the crystal, the mol­ecular framework is almost planar with an r.m.s. deviation of 0.091 (4) Å and it exists in an E form. Intra­molecular C—H⋯O and C—H⋯N hydrogen bonds are observed between the benzene and 1,3,4-oxadiazole rings. The tert-butyl group is disordered over two sites, with occupancy factors of 0.78 (1) and 0.22 (1) for the major and minor orientations, respectively. In the crystal structure, mol­ecules aggregate via C—H⋯N inter­actions, forming mol­ecular tapes along the b axis, which aggregate to form a mol­ecular sheet via C—H⋯N inter­actions

5,5-Bis(4-methoxy­phen­yl)-2,8-bis­[3-(trifluoro­meth­yl)phen­yl]-5H-cyclo­penta­[2,1-b:3,4-b’]dipyridine

The title compound, C39H26F6N2O2, showed two melting transitions 477.4 and 506.5 K in a differential scanning calorimetry (DSC) study. The first of these can be attributed to a melting phase transition arising from the rotation of two trifluoro­methyl groups. In the crystal structure, both trifluoro­methyl groups are disordered over two sites with occupancy factors of 0.660 (17) and 0.340 (17) for the major and minor orientations, respectively. The introduction of trifluoro­methyl groups inhibits π-stacking between the diaza­fluorene (cyclo­penta­[2,1-b:3,4-b’]dipyridine) units. Three short F⋯O contacts between 2.80 (3) and 2.95 (1) Å are observed in the crystal structure

(3Z,3′Z)-3,3′-(Ethane-1,2-diyl­idene)­bis[isobenzofuran-1(3H)-one]

The title compound, C18H10O4, has been isolated as an impurity in commercially available 6,11-dihydr­oxy-5,12-naphth­acenedione. The title compound exhibits yellow fluorescence in the solid state. The mol­ecule has crystallographic inversion symmetry and is planar, with an r.m.s. deviation of 0.031 (1) Å. The crystal structure is stabilized by C—H⋯O hydrogen bonds and π–π stacking inter­actions between 3-methyl­eneisobenzofuran-1(3H)-one units [inter­planar distance 3.43 (1) Å]

Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier

The power consumption of a conventional photoreceiver is dominated by that of the electric amplifier connected to the photodetector (PD). An ultralow-capacitance PD can overcome this limitation, because it can generate sufficiently large voltage without an amplifier when combined with a high-impedance load. In this work, we demonstrate an ultracompact InGaAs PD based on a photonic crystal waveguide with a length of only 1.7 μm and a capacitance of less than 1 fF. Despite the small size of the device, a high responsivity of 1 A/W and a clear 40 Gbit/s eye diagram are observed, overcoming the conventional trade-off between size and responsivity. A resistor-loaded PD was actually fabricated for light-to-voltage conversion, and a kilo-volt/watt efficiency with a gigahertz bandwidth even without amplifiers was measured with an electro-optic probe. Combined experimental and theoretical results reveal that a bandwidth in excess of 10 GHz can be expected, leading to an ultralow energy consumption of less than 1 fJ/bit for the photoreceiver. Amplifier-less PDs with attractive performance levels are therefore feasible and a step toward a densely integrated photonic network/processor on a chip

Rehabilitation Using 13-Degree Forward Bending Poles for Patients with Rheumatoid Arthritis After a Total Joint Replacement.

Here we evaluate the usefulness of 13-degree forward bending pole-assisted walking to promote the early discharge of rheumatoid arthritis patients after a total joint arthroplasty. We evaluated two male and six female rheumatoid arthritis patients with an average age of 64 who received a total hip or knee arthroplasty. We required them to perform pole-assisted walking five times a week for 20 minutes a day. Rehabilitation lasted 4-6 weeks until discharge. Clinical follow-up included mobility, physical strength and flexibility assessments. After 1 year of pole-assisted walking, two patients can play golf without the assistance of a cane. Patients who performed pole-assisted walking improved their walking speed 1 year after surgery by 5 seconds compared with speeds measured 4 weeks after surgery. Chair stand repetitions also increased over that time. Pole-assisted walking improved the stability and safety of the ambulation of rheumatoid arthritis patients after surgery. Patients also reported improved arm and leg strength. No falls were reported 5 years after surgery. This clinical trial is thought to be specific to patients with severe pain in many joints including knees and hips