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1.
J Nat Prod ; 84(10): 2738-2743, 2021 10 22.
Article in English | MEDLINE | ID: mdl-34612636

ABSTRACT

A simple methylenedioxy dibromoindole alkaloid, amakusamine (1), was isolated from a marine sponge of the genus Psammocinia, and its structure was determined from spectroscopic data, time-dependent density-functional theory calculations, and synthesis. Compound 1 inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinuclear osteoclasts with an IC50 value of 10.5 µM in RAW264 cells. The structure-activity relationship of 1 was also investigated with synthetic derivatives.


Subject(s)
Alkaloids/pharmacology , Osteoclasts/drug effects , Porifera/chemistry , RANK Ligand/antagonists & inhibitors , Animals , Japan , Mice , Molecular Structure , RAW 264.7 Cells , Structure-Activity Relationship
2.
Chem Commun (Camb) ; 56(94): 14905-14908, 2020 Nov 26.
Article in English | MEDLINE | ID: mdl-33179651

ABSTRACT

In situ monitoring of initial oxidation of GaAs surfaces was performed under (near-) realistic oxidizing environments, using ambient-pressure X-ray photoelectron spectroscopy (AP-XPS). The surface chemical states drastically change with time. The oxidation process at the sub-nano-meter-scale exhibits a significantly small activation energy, which can be regarded as a quasi-barrier-less oxidation.

3.
J Nat Med ; 74(3): 545-549, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32236853

ABSTRACT

Fungal co-culture is a strategy to induce the production of secondary metabolites by activating cryptic genes. We discovered the production of a new compound, talarodone A (1), along with five known compounds 2-6 in co-culture of Talaromyces pinophilus and Paraphaeosphaeria sp. isolated from soil collected in Miyazaki Prefecture, Japan. Among them, the productions of penicidones C (2) and D (3) were enhanced 27- and sixfold, respectively, by the co-culture. The structure of 3 should be represented as a γ-pyridol form with the reported chemical shifts, but not as a γ-pyridone form, based on DFT calculation.


Subject(s)
Pyridones/metabolism , Saccharomycetales/metabolism , Talaromyces/metabolism , Coculture Techniques , Japan , Pyridones/chemistry , Saccharomycetales/growth & development , Saccharomycetales/isolation & purification , Soil Microbiology , Talaromyces/growth & development , Talaromyces/isolation & purification
4.
IEEE Trans Biomed Circuits Syst ; 13(6): 1152-1162, 2019 12.
Article in English | MEDLINE | ID: mdl-31675341

ABSTRACT

A supply voltage monitor (SVM) with self-controlled dual-oscillator-based architecture is proposed herein for biosensing systems combined with a biofuel cell (BFC) in this paper. The output of the BFCs can be used to monitor the biological signals while powering the BFC-combined biosensing systems. Thus, the SVM is designed to convert the change in the supply voltage (V DD) into a code. The architecture of the proposed SVM allows self-controlled periodic operation without external signals. Furthermore, the frequency subtraction technique that uses two oscillators employing gate-leakage-based architecture with different frequency sensitivities to V DD allows accurate code generation with low power consumption and a small circuit area for supply voltage monitoring. The proposed SVM is fabricated using two different CMOS process technologies, including 65-nm CMOS and 55-nm deeply depleted channel (DDC) CMOS. The implementation of the 65-nm CMOS obtains an operating V DD range of 250 mV (0.75-1 V), draws a standby power consumption of 1.4 nW at 0.75-V V DD, exhibits a resolution of 2.4 mV with a nonlinearity error of -8.4/ +12.1 mV, and occupies a circuit area of 0.0047 mm2. Meanwhile, the implementation of the 55-nm DDC CMOS for low-voltage operation achieves an operating V DD range of 300 mV (0.225-0.525 V), draws a standby power consumption of 32.5 nW at 0.25-V V DD, exhibits a resolution of 0.94 mV with a nonlinearity error of -15.2/ +14 mV, and occupies a circuit area of 0.0032 mm2.


Subject(s)
Bioelectric Energy Sources , Biosensing Techniques/instrumentation , Electric Power Supplies , Equipment Design , Signal Processing, Computer-Assisted
5.
IEEE Trans Biomed Circuits Syst ; 13(2): 470-479, 2019 04.
Article in English | MEDLINE | ID: mdl-30475728

ABSTRACT

A fully integrated CMOS circuit based on a vector network analyzer and a transmission-line-based detection window for circulating tumor cell (CTC) and exosome analysis is presented for the first time. We have introduced a fully integrated architecture, which eliminates the undesired parasitic components and enables high-sensitivity, to analyze extremely low-concentration CTC in blood. The detection window was designed on the high-sensitive coplanar waveguide line. To validate the operation of the proposed system, a test chip was fabricated using 65-nm CMOS technology. Measurements were performed after adding a tiny lump of silicone or a droplet of water on its detection window. The measured results show |S_21| degradation of -1.96 dB and -6.04 dB for the silicone and the droplet, respectively, at 1.4 GHz. In addition, in another measurement using magnetic beads, it is confirmed that the proposed circuit can analyze even low concentrations of 20 beads/µL. As well as microbeads, measurement with CTCs was successfully demonstrated.


Subject(s)
Exosomes/metabolism , Metals/chemistry , Neoplastic Cells, Circulating/pathology , Oxides/chemistry , Semiconductors , Amplifiers, Electronic , Cell Line, Tumor , Electricity , Humans , Wavelet Analysis
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