24 research outputs found
Two stage superconducting quantum interference device amplifier in a high-Q gravitational wave transducer
We report on the total noise from an inductive motion transducer for a
gravitational-wave antenna. The transducer uses a two-stage SQUID amplifier and
has a noise temperature of 1.1 mK, of which 0.70 mK is due to back-action noise
from the SQUID chip. The total noise includes thermal noise from the transducer
mass, which has a measured Q of 2.60 X 10^6. The noise temperature exceeds the
expected value of 3.5 \mu K by a factor of 200, primarily due to voltage noise
at the input of the SQUID. Noise from flux trapped on the chip is found to be
the most likely cause.Comment: Accepted by Applied Physics Letters tentatively scheduled for March
13, 200
Atractylodes chinensis Water Extract Ameliorates Obesity via Promotion of the SIRT1/AMPK Expression in High-Fat Diet-Induced Obese Mice
Obesity remains a continuing global health concern, as it is associated with an increased risk of many chronic diseases. Atractylodes chinensis Koidz. (Ac) is traditionally used in the treatment of inflammatory diseases, such as arthritis, hepatitis, and gastric ulcers. Despite the diverse pharmacological activities of Ac, scientific evidence for the use of Ac in obesity is still limited. Therefore, the present study aimed to determine the anti-obesity effects of Ac. C57BL/6N mice were divided into five groups as follows: chow diet group (CON), 45% HFD group, HFD + oral administration of orlistat group, and HFD + oral administration of Ac groups. RT-PCR and western blotting were used to examine the expression of molecules relating to obesity progression. Ac-administered mice showed dramatically decreased body weight and weight gain compared to the high-fat diet (HFD)-fed mice. In addition, Ac administration attenuated the protein expression levels of adipogenic transcription factors in the white adipose tissue (WAT) and livers of HFD-fed mice. Furthermore, Ac administration declined the expression levels of lipogenic genes, while enhancing those of the fatty acid oxidation genes in the WAT of HFD-fed mice. Importantly, Ac administration highly upregulated the AMP-activated kinase (AMPK) and sirtuin 1 (SIRT1) expression levels in WAT of the HFD-induced obese mouse model. Our results provide evidence that Ac can effectively ameliorate weight gain and adipose tissue expansion
Iron Oxide@PEDOT-Based Recyclable Photothermal Nanoparticles with Poly(vinylpyrrolidone) Sulfobetaines for Rapid and Effective Antibacterial Activity
Growing microbial resistance that
renders antibiotic treatment
vulnerable has emerged, attracting a great deal of interest in the
need to develop alternative antimicrobial treatments. To contribute
to this effort, we report magnetic iron oxide (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles (NPs) coated with catechol-conjugated polyĀ(vinylpyrrolidone)
sulfobetaines (C-PVPS). This negatively charged Fe<sub>3</sub>O<sub>4</sub>@C-PVPS is subsequently encapsulated by polyĀ(3,4-ethylenedioxythiophene)
(PEDOT) following a layer-by-layer (LBL) self-assembly method. The
obtained Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT nanoparticles appear
to be novel NIR-irradiated photothermal agents that can achieve effective
bacterial killing and are reusable after isolation of the used particles
using external magnetic fields. The recyclable Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT NPs exhibit a high efficiency in converting
photothermal heat for rapid antibacterial effects against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i>. In this study, antibacterial tests for repeated uses maintained
almost 100% antibacterial efficiency during three cycles and provided
rapid and effective killing of 99% Gram-positive and -negative bacteria
within 5 min of near-infrared (NIR) light exposure. The coreāshell
nanoparticles (Fe<sub>3</sub>O<sub>4</sub>@C-PVPS:PEDOT) exhibit the
required stability, and their paramagnetic nature means that they
rapidly convert photothermal heat sufficient for use as NIR-irradiated
antibacterial photothermal sterilizing agents
Pharmacological Properties of a Traditional Korean Formula Bojungchiseup-tang on 3T3-L1 Preadipocytes and High-Fat Diet-Induced Obesity Mouse Model
The global obesity epidemic has nearly doubled since 1980, and this increasing prevalence is threatening public health. It has been reported that natural products could contain potential functional ingredients that may assist in preventing obesity. Bojungchiseub-tang (BJT), mentioned in the Donguibogam as an herbal medication for the treatment of edema, a symptom of obesity, consists of eleven medicinal herbs. However, the pharmacological activity of BJT has not been investigated. The present study was designed to investigate the putative effect of BJT on the adipogenesis of 3T3-L1 cells and the weight gain of high-fat diet (HFD-) fed C57BL/6 mice. Oil Red O staining was conducted to examine the amount of lipids in 3T3-L1 adipocytes. Male C57BL/6 mice were divided into three groups: standard diet group (control, CON), 45% HFD group (HFD), and HFD supplemented with 10% of BJT (BJT). The expression levels of genes and proteins related to adipogenesis in cells, WAT, and liver were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. We found that BJT treatment significantly decreased the protein and mRNA levels of peroxisome proliferator-activated receptor Ī³ (PPARĪ³), CCAAT/enhancer-binding protein Ī± (C/EBPĪ±), and sterol regulatory element-binding protein 1 (SREBP1) in a dose-dependent manner in differentiated 3T3-L1 cells. Similar to the results of the in vitro experiment, BJT suppressed HFD-induced weight gain in an obese mouse model. In addition, BJT effectively reduced the HFD-induced epididymal adipose tissue weight/body weight index. BJT also downregulated the mRNA levels of PPARĪ³, C/EBPĪ±, and SREBP1 in the epididymal adipose and liver tissue of HFD-fed obese mice. These findings suggest that BJT induces weight loss by affecting adipogenic transcription factors
Phase-controlled 1T/2H-MoS2interaction with reduced TiO2for highly stable photocatalytic CO2reduction into CO
Photocatalytic CO2 reduction is a potential technique for converting solar energy and greenhouse gases into value-added-chemicals. However, limited light absorption and poor charge separation of electron-hole pairs are the main obstacles. Here, we have developed a highly stable, phase-controlled heterostructured photocatalyst of molybdenum sulfide with reduced titania (1T/2H-MoS2@RT) for CO2 reduction into CO. The optimized 1T/2H-MoS2@RT produced 1.02 Ī¼mol g-1 h-1 (1480.1 ppm g-1 h-1) of CO. The catalyst showed ā¼5 and ā¼19 times higher activity than RT and MoS2, respectively, and excellent stability over 48 h (8 cycles). Our investigation revealed that the combination of phase-controlled MoS2 with RT synergizes the selective conversion of CO2 to CO. MoS2 acts as a visible light sensitizer and electron transport bridge; however, RT extracts electrons from MoS2 because of its lower energy potential. Improved light absorption, CO2 adsorption, and rapid electron-hole separation are responsible for the increased catalytic activity and stability. Ā© 2022 The Authors.TRU
Functionalized MXene ink enables environmentally stable printed electronics
Abstract Establishing dependable, cost-effective electrical connections is vital for enhancing device performance and shrinking electronic circuits. MXenes, combining excellent electrical conductivity, high breakdown voltage, solution processability, and two-dimensional morphology, are promising candidates for contacts in microelectronics. However, their hydrophilic surfaces, which enable spontaneous environmental degradation and poor dispersion stability in organic solvents, have restricted certain electronic applications. Herein, electrohydrodynamic printing technique is used to fabricate fully solution-processed thin-film transistors with alkylated 3,4-dihydroxy-L-phenylalanine functionalized Ti3C2T x (AD-MXene) as source, drain, and gate electrodes. The AD-MXene has excellent dispersion stability in ethanol, which is required for electrohydrodynamic printing, and maintains high electrical conductivity. It outperformed conventional vacuum-deposited Au and Al electrodes, providing thin-film transistors with good environmental stability due to its hydrophobicity. Further, thin-film transistors are integrated into logic gates and one-transistor-one-memory cells. This work, unveiling the ligand-functionalized MXenesā potential in printed electrical contacts, promotes environmentally robust MXene-based electronicsĀ (MXetronics)