Synthesis of optically active 2-ethyl-1,6-dioxaspiro[4.4]nonane (chalcogran), the principal aggregation pheromone of pityogenes chalcographus (l.)1

((2R, 5RS)- and (2S, 5RS)-2-Ethyl-1,6-dioxaspiro[4.4]nonanes (chalcograns) were synthesized in a simple manner by applying the recent technique of dianion chemistry.     

Non-Sonogashira-type palladium-catalyzed coupling reactions of terminal alkynes assisted by silver(I) oxide or tetrabutylammonium fluoride

Palladium-catalyzed reaction of aryl and alkenyl halides with terminal alkynes in the presence of silver(I) oxide as an activator furnishes various arylated or alkenylated alkynes in good to excellent yields. The similar coupling reaction is also found to proceed using tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH) as an activator.     

Stereocontrolled synthesis of all of the possible stereoisomers of 3,11-dimethylnonacosan-2-one and 29-hydroxy-3,11-dimethylnonacosan-2-one : The female sex pheromone of the german cockroach

All of the possible stereoisomers of 3, 11 - dimethylnonacosan - 2 - one 1 and 29 - hydroxy - 3, 11 -dimethylnonacosan - 2 - one 2 were synthesized from (R)-(+)- citronellic acid as the chiral source. The natural pheromones were shown to be (3S,11S)-1 and (3S, 11S)-2 by direct comparisons.     

A Pixelized Variable Optical Attenuator Using Liquid Crystal on Silicon Technology for Tunable Filters

We apply liquid crystal on silicon (LCOS) in 0.8-$mUm standard complementary metal-oxide semiconductor (CMOS) technology to demonstrate a low-cost, high-performance pixelized liquid crystal variable optical attenuator (VOA) with pulse width modulation. We then build a prototype tunable filter by using this VOA along with a grating in the Littrow configuration. With the application of 5-V pulse width modulation, the proposed VOA achieves a 5.6-dB insertion loss, a dynamic range of more than 20 dB, a 50-GHz channel spacing capability, and a polarization-dependent loss (PDL) of less than 0.6 dB at 15-dB attenuation. Our VOA is suitable for applications such as dynamic channel gain equalizers, channel-blocking filters, sub-components of re-configurable add-drop modules, and wavelength selectors.     

Synthesis of optically active forms of (Z)-14-methylhexadec-8-enal : The pheromone of female dermestid beetle

The both enantiomers of (Z)-14-methylhexadec-8-enal were synthesized starting from (R)-(+)-citronellol. The (R)-(?)enantiomer (1) was about 250 times more active than its antipode (1') when tested on dermestid beetle.     

Optical pulse compression to 3.4 fs in the monocycle region by feedback phase compensation

We compensated for chirp of optical pulses with an over-one-octave bandwidth (495-1090 nm; center wavelength of 655.4 nm) produced by self-phase modulation in a single argon-filled hollow fiber and generated 3.4-fs, 1.56 optical-cycle pulses (500 nJ, 1-kHz repetition rate). This was achieved with a feedback system combined with only one 4-f phase compensator with a spatial light modulator and a significantly improved phase characterizer based on modified spectral phase interferometry for direct electric-field reconstruction. To the best of our knowledge, this is the shortest pulse in the visible-to-infrared region.     

A method for the determination of tritium in environmental water samples by electrolytic enrichment

In order to determine the tritium concentration in environmental water samples, the electrolytic enrichment was carried out with (St) and without (S) addition of tritiated water of a certain concentration (deuterium-free) to the samples. With the use of the fundamental formulas on electrolytic enrichment, the deuterium concentration (Dit) before electrolysis for an environmental water sample is determined by liquid scintillation counting and densitometry for the sample St. Furthermore, the tritium concentration in the environmental water sample is determined by the above methods for the sample S, and by the substitution of Dit for Di in the formulas. Tritium concentrations in environmental water samples were found to be determined within an accuracy of 10% by this method when Vi/Vf was 14-25. It is considered that this method dispenses with the direct measurement of low deuterium concentrations (Di) before electrolysis, a special technique on the purification of water for densitometry, and moreover, excludes the possibility of cross contamination in the electrolytic enrichment by the spike cell method.     

The Two-Way Switch Role of ACE2 in the Treatment of Novel Coronavirus Pneumonia and Underlying Comorbidities

December 2019 saw the emergence of the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has spread across the globe. The high infectivity and ongoing mortality of SARS-CoV-2 emphasize the demand of drug discovery. Angiotensin-converting enzyme II (ACE2) is the functional receptor for SARS-CoV-2 entry into host cells. ACE2 exists as a membrane-bound protein on major viral target pulmonary epithelial cells, and its peptidase domain (PD) interacts SARS-CoV-2 spike protein with higher affinity. Therefore, targeting ACE2 is an important pharmacological intervention for a SARS-CoV-2 infection. In this review, we described the two-way switch role of ACE2 in the treatment of novel coronavirus pneumonia and underlying comorbidities, and discussed the potential effect of the ACE inhibitor and angiotensin receptor blocker on a hypertension patient with the SARS-CoV-2 infection. In addition, we analyzed the S-protein-binding site on ACE2 and suggested that blocking hot spot-31 and hot spot-353 on ACE2 could be a therapeutic strategy for preventing the spread of SARS-CoV-2. Besides, the recombinant ACE2 protein could be another potential treatment option for SARS-CoV-2 induced acute severe lung failure. This review could provide beneficial information for the development of anti-SARS-CoV-2 agents via targeting ACE2 and the clinical usage of renin-angiotensin system (RAS) drugs for novel coronavirus pneumonia treatment.     

Fabrication of a Practical and Polymer‐Rich Organic Radical Polymer Electrode and its Rate Dependence

A practical and polymer‐rich organic radical cathode that contains 80 wt.‐% poly(4‐vinyloxy‐2,2,6,6‐tetramethylpiperidine‐N‐oxyl) (PTVE) and 15 wt.‐% vapor‐grown carbon fiber (VGCF) has been fabricated. The PTVE/VGCF composite electrode shows a reversible redox peak at 3.56 V (vs Li/Li⁺) in cyclic voltammetry. A coin‐type cell with the PTVE/VGCF composite electrode as the cathode and lithium metal as the anode has also been fabricated and used for charge/discharge measurements. When the cell was discharged at 0.3 mA · cm⁻² (1 C), a capacity of 104 mAh · g⁻¹, which is 77% of PTVE's theoretical capacity (135 mAh · g⁻¹), was obtained. When it was discharged at 9.0 mA · cm⁻² (30 C), its capacity was 52% of the capacity it had when it was discharged at 0.3 mA · cm⁻² (1 C). Even when discharged at 24 mA · cm⁻² (80 C), it surprisingly had 32% of the capacity it had when discharged at 0.3 mA · cm⁻². The observed rate dependence shows that the polymer‐rich electrode could discharge over 50% of the cell capacity in two minutes and over 30% within one minute.