Study on impact of silver nanoparticles synthesized using aqueous extract of Ganoderma applanatum on thyroid and lipid parameters of albino rat

Se estudió el impacto de SNP cargadas con extracto de Ganoderma applanatum sobre el perfil tiroideo y lipídico de rata. Las SNP (diámetro medio 58,77 nm; potencial zeta - 3,8) mV se analizaron mediante DLS. La microespectroscopía de infrarrojo con transformada de Fourier proporcionó un pico de transmisión amplio y elevado a 3248,12 cm-1, que indica la carga bioquímica del extracto de G. applanatum en la superficie de los SNP. No se observó mortalidad ni cambios de comportamiento en la prueba de toxicidad aguda. El grupo-1 recibió 1 mL de agua destilada, el grupo-2 y el grupo-3 recibieron 200 mg kg-1 y 400 mg kg-1 de nanopartículas respectivamente. Una dosis de 400 mg kg-1 de SNPs mostró una mayor actividad hipertiroidea e hipolipidímica en comparación con el control y la dosis de 200 mg kg-1. Impact of silver nanoparticles loaded with Ganoderma applanatum extract on thyroid and lipid profile of rat were studied. Synthesized SNPs (Average diameter 58.77 nm; -13.8 mV zeta potential) were analysed by dynamic light scattering analysis. Fourier transform infrared spectroscopy provided broad and high transmission peak at 3248.12 cm-1 which indicates the loaded biochemical of the G. applanatum extract on the surface of SNPs. No mortality and behavioural changes were observed in the Acute toxicity test. Group-1 received 1 mL distilled water, group-2 and group-3 received 200 mg kg-1 and 400 mg kg-1 nanoparticles respectively. A 400 mg kg-1 dose of SNPs showed increased hyper thyroid and hypolipidimic activity as compared to control and 200 mg kg-1 dose.

High Sensitivity Terahertz Biosensor Based on Mode Coupling of a Graphene/Bragg Reflector Hybrid Structure

In this work, a high-sensitivity terahertz (THz) biosensor is achieved by using a graphene/Bragg reflector hybrid structure. This high-sensitivity THz biosensor is developed from the sharp Fano resonance transmission peak created by coupling the graphene Tamm plasmons (GTPs) mode to a defect mode. It is found that the proposed THz biosensor is highly sensitive to the Fermi energy of graphene, as well as the thickness and refractive index of the sensing medium. Through specific parameter settings, the composite structure can achieve both a liquid biosensor and a gas biosensor. For the liquid biosensor, the maximum sensitivity of >1000°/RIU is obtained by selecting appropriate parameters. We believe the proposed layered hybrid structure has the potential to fabricate graphene-based high-sensitivity biosensors.

Simulation and Experimental Study of Terahertz Wave Transmission Characteristics Based on Periodic Metal Open Resonant Ring Structures

Different open resonant ring structures with substrate of polyimide were designed. The transmission characteristics of the structures for terahertz wave were investigated by simulation and experiment. The results show that the transmission peak of the structures moves to high frequency with increase of thickness of the metal layer. With increase of substrate thickness, the transmission peak moved to low frequency and the transmissivity decreased. The influence of number of “C” shape open resonant rings in the unit structure on the transmission characteristics of terahertz wave was also studied. It is found that when the number of “C” shape open resonant rings increases from one to two, more transmission peaks appeared in the frequency of 0.2–2 THz. The transmissivity of the designed structures was tested by terahertz time-domain spectrometer (THz-TDS). The experimental results showed good agreement to the simulation results.

Modulation of the Transmission Spectra of the Double-Ring Structure by Surface Plasmonic Polaritons

This paper proposes a new structural design to excite surface plasmonic polaritons to enhance the double-ring interference structure. The double-ring structure was etched into a thin film to form fundamental interference patterns, and periodic concentric-ring grooves were employed to gather energy from the surrounding regions through the excitation of surface plasmonic polaritons. Accordingly, the energy of the incident light can be concentrated at the center. The surface plasmon modulates the interference pattern and the transmission spectra. The transmission peak position and its intensity can be tuned by changing the alignment of the grooves. The proposed structure can be applied for designing plasmonic devices as useful components of the plasmonic toolbox.

Correlation between Local Eid-al-Fitr Homecoming (Mudik) with Coronavirus Disease-19 during Ramadhan Season Amidst Large-scale Social Distancing in Indonesia

BACKGROUND: In anticipation of coronavirus disease (COVID)-19’s transmission peak, Eid-al-Fitr homecoming (mudik) has officially been banned by the Indonesian government interlocal but not local in welcoming this religious Muslim celebration. This local Mudik is held by traveling among regional provinces and is still allowed by each local government, including Java, which has the highest transmission of COVID-19 in Indonesia. AIM: This study aims to present the difference between COVID-19 status before and during local Mudik on Java during Ramadhan with the implementation of large-sale social distancing applied in Jakarta, Indonesia. METHODS: This research was employed by secondary data analysis that was obtained from surveillance data from related authorities, including the Ministry of Health and all local governments of Java, which consisted of four provinces and Jakarta. Incidence and suspect statuses of COVID-19, which were examined in the study, were presented in daily rates with before and during local Mudik in four provinces: Jawa Barat, Yogyakarta, Banten, and Jawa Tengah. RESULTS: The number of positive confirmed patients differed significantly with before and during local Mudik (p < 0.05; mean difference = −/negative values). CONCLUSION: This study’s findings showed that the local Mudik increased the number of COVID-19 cases in four provinces in Java, which these provinces were designated as Mudik destinations by travelers coming from Jakarta during the end of Ramadhan season.

Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

Selective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.

Color-Adjustable Devices Based on the Surface Plasmons Effect

The optical response of a metamaterial can be engineered by manipulating the size, pattern, and composition of its cells. Here, we present a coloring device, which increases resolution while retaining adjustability. By adding different nanoparticles in the nanohole, the shift of the transmission peak in the visible regions is realizable and manageable, which means a series of different colors are revealed in this device. At the same time, it is also possible to fill the holes with dielectric materials of different refractive indices to achieve the purpose of color diversity. This method theoretically confirms the feasibility of designing a coloring device via surface plasmons-based metamaterial nanostructure, which holds great promise for future versatile utilization of multiple physical mechanisms to render multiple colors in a simple nanostructure.

The Influence of Heat Treatment on the Phononic Multilayer Sensor

In the work, the transmission of aperiodic quasi one-dimensional sensor built of Zr55Cu30Ni5Al10 amorphous alloy was tested using the Transfer Matrix Method algorithm. Transmission peak shifts were analyzed depending on the temperature of the flowing liquid. The influence of annealing in the temperatures 693K and 773K of the amorphous alloy on the structure of the sensor transmission bands was analyzed. The existence of bands in the examined structures has been shown. The best phononic properties were found in the structure heated to 773 K.

The Influence of Heat Treatment on the Phononic Multilayer Sensor

In the work, the transmission of aperiodic quasi one-dimensional sensor built of Zr55Cu30Ni5Al10 amorphous alloy was tested using the Transfer Matrix Method algorithm. Transmission peak shifts were analyzed depending on the temperature of the flowing liquid. The influence of annealing in the temperatures 693K and 773K of the amorphous alloy on the structure of the sensor transmission bands was analyzed. The existence of bands in the examined structures has been shown. The best phononic properties were found in the structure heated to 773 K. Keywords: phononic, transfer marix, aperiodic, multilayers, acoustic