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1.
Molecules ; 29(13)2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38998988

RESUMEN

Naturally occurring homoisoflavonoids isolated from some Liliaceae plants have been reported to have diverse biological activities (e.g., antioxidant, anti-inflammatory, and anti-angiogenic effects). The exact mechanism by which homoisoflavonones exert anti-neuroinflammatory effects against activated microglia-induced inflammatory cascades has not been well studied. Here, we aimed to explore the mechanism of homoisoflavonoid SH66 having a potential anti-inflammatory effect in lipopolysaccharide (LPS)-primed BV2 murine microglial cells. Microglia cells were pre-treated with SH66 followed by LPS (100 ng/mL) activation. SH66 treatment attenuated the production of inflammatory mediators, including nitric oxide and proinflammatory cytokines, by down-regulating mitogen-activated protein kinase signaling in LPS-activated microglia. The SH66-mediated inhibition of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex and the respective inflammatory biomarker-like active interleukin (IL)-1ß were noted to be one of the key pathways of the anti-inflammatory effect. In addition, SH66 increased the neurite length in the N2a neuronal cell and the level of nerve growth factor in the C6 astrocyte cell. Our results demonstrated the anti-neuroinflammatory effect of SH66 against LPS-activated microglia-mediated inflammatory events by down-regulating the NLRP3 inflammasome complex, with respect to its neuroprotective effect. SH66 could be an interesting candidate for further research and development regarding prophylactics and therapeutics for inflammation-mediated neurological complications.


Asunto(s)
Antiinflamatorios , Lipopolisacáridos , Microglía , Microglía/efectos de los fármacos , Microglía/metabolismo , Lipopolisacáridos/farmacología , Animales , Ratones , Antiinflamatorios/farmacología , Antiinflamatorios/química , Línea Celular , Isoflavonas/farmacología , Isoflavonas/química , Citocinas/metabolismo , Óxido Nítrico/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Inflamasomas/metabolismo
2.
Bioorg Med Chem Lett ; 92: 129390, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37369329

RESUMEN

Naturally occurring homoisoflavonoids have attracted significant attention in the field of medicinal chemistry due to their potential health benefits and diverse range of biological properties. Recently, C-prenylated homoisoflavonoids, namely ledebourin A, B, and C, were isolated from the bulbs of Ledebouria floribunda and have exhibited potent antioxidant activity. In this study, we successfully synthesized ledebourin A and its regioisomer, compounds 1 and 9. By comparing the NMR spectra of the synthesized compounds with those of reported ledebourin A, we observed discrepancies. Nonetheless, our synthesis and subsequent findings offer valuable insights into the structural revision and biological activities of these unique prenylated homoisoflavonoids. Both synthesized compounds 1 and 9 exhibited no toxicity towards Hep-G2 cells and displayed the ability to recover glyceraldehyde-induced cell death, suggesting their potential as protective agents against liver damage.


Asunto(s)
Isoflavonas , Isoflavonas/química , Antioxidantes/química , Extractos Vegetales/química , Espectroscopía de Resonancia Magnética , Estructura Molecular
3.
Sensors (Basel) ; 23(8)2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-37112374

RESUMEN

In this work, we developed a prototype that adopted sound-based systems for localization of visually impaired individuals. The system was implemented based on a wireless ultrasound network, which helped the blind and visually impaired to navigate and maneuver autonomously. Ultrasonic-based systems use high-frequency sound waves to detect obstacles in the environment and provide location information to the user. Voice recognition and long short-term memory (LSTM) techniques were used to design the algorithms. The Dijkstra algorithm was also used to determine the shortest distance between two places. Assistive hardware tools, which included an ultrasonic sensor network, a global positioning system (GPS), and a digital compass, were utilized to implement this method. For indoor evaluation, three nodes were localized on the doors of different rooms inside the house, including the kitchen, bathroom, and bedroom. The coordinates (interactive latitude and longitude points) of four outdoor areas (mosque, laundry, supermarket, and home) were identified and stored in a microcomputer's memory to evaluate the outdoor settings. The results showed that the root mean square error for indoor settings after 45 trials is about 0.192. In addition, the Dijkstra algorithm determined that the shortest distance between two places was within an accuracy of 97%.


Asunto(s)
Dispositivos de Autoayuda , Personas con Daño Visual , Humanos , Sistemas de Información Geográfica , Ultrasonografía , Algoritmos
4.
Sensors (Basel) ; 22(19)2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36236334

RESUMEN

A modified monopole patch antenna for microwave-based hemorrhagic or ischemic stroke recognition is presented in this article. The designed antenna is fabricated on a cost-effective FR-4 lossy material with a 0.02 loss tangent and 4.4 dielectric constant. Its overall dimensions are 0.32 λ × 0.28 λ × 0.007 λ, where λ is the lower bandwidth 1.3 GHz frequency wavelength. An inset feeding approach is utilized to feed the antenna to reduce the input impedance (z = voltage/current). A total bandwidth (below -10 dB) of 2.4 GHz (1.3-3.7 GHz) is achieved with an effective peak gain of over 6 dBi and an efficiency of over 90%. A time-domain analysis confirms that the antenna produces minimal signal distortion. Simulated and experimental findings share a lot of similarities. Brain tissue is penetrated by the antenna to a satisfactory degree, while still exhibiting a safe specific absorption rate (SAR). The maximum SAR value measured for the head model is constrained to be equal to or below 0.1409 W/kg over the entire usable frequency band. Evaluation of theoretical and experimental evidence indicates the intended antenna is appropriate for Microwave Imaging (MWI) applications.


Asunto(s)
Imágenes de Microonda , Tecnología Inalámbrica , Encéfalo , Diseño de Equipo , Microondas
5.
Sensors (Basel) ; 20(5)2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32121477

RESUMEN

An Ultrawideband (UWB) octagonal ring-shaped parasitic resonator-based patch antenna for microwave imaging applications is presented in this study, which is constructed with a diamond-shaped radiating patch, three octagonal, rectangular slotted ring-shaped parasitic resonator elements, and partial slotting ground plane. The main goals of uses of parasitic ring-shaped elements are improving antenna performance. In the prototype, various kinds of slots on the ground plane were investigated, and especially rectangular slots and irregular zigzag slots are applied to enhance bandwidth, gain, efficiency, and radiation directivity. The optimized size of the antenna is 29 × 24 × 1.5 mm3 by using the FR-4 substrate. The overall results illustrate that the antenna has a bandwidth of 8.7 GHz (2.80 ̶ 11.50 GHz) for the reflection coefficient S11 < -10 dB with directional radiation pattern. The maximum gain of the proposed prototype is more than 5.7 dBi, and the average efficiency over the radiating bandwidth is 75%. Different design modifications are performed to attain the most favorable outcome of the proposed antenna. However, the prototype of the proposed antenna is designed and simulated in the 3D simulator CST Microwave Studio 2018 and then effectively fabricated and measured. The investigation throughout the study of the numerical as well as experimental data explicit that the proposed antenna is appropriate for the Ultrawideband-based microwave-imaging fields.

6.
Soft Matter ; 15(43): 8865-8878, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31616877

RESUMEN

We consider the collective dynamics of self-propelling particles in two dimensions. They can align themselves according to the direction of propulsion of their neighbours, together with small rotational fluctuations. They also interact with each other via soft, isotropic, repulsive potentials. The particles are confined in a circular trap. The steepness of the trap is tuneable. The average packing fraction of the particles is low. When the trap is steep, particles flock along its boundary. They form a polar cluster that spreads over the boundary. The cluster is not spatially ordered. We show that when the steepness is decreased beyond a threshold value, the cluster becomes round and compact and eventually spatial order (hexagonal) emerges in addition to the pre-established polar order. We investigate the kinetics of such ordering. We find that while rotating around the centre of the trap along its circular boundary, the cluster needs to roll around its centre of mass to be spatially ordered. We have studied the stability of the order when the trap is suddenly switched off. We find that for the particles with velocity alignment interaction, the decay of the spatial order is much slower than the particles without the alignment interaction.

7.
Sensors (Basel) ; 18(12)2018 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-30518080

RESUMEN

A simple, compact sickle-shaped printed antenna with a slotted ground plane is designed and developed for broadband circularly polarized (CP) radiation. The sickle-shaped radiator with a tapered feed line and circular slotted square ground plane are utilized to realize the wideband CP radiation feature. With optimized dimensions of 0.29λ × 0.29λ × 0.012λ at 2.22 GHz frequency for the realized antenna parameters, the measured results display that the antenna has a 10 dB impedance bandwidth of 7.70 GHz (126.85%; 2.22⁻9.92 GHz) and a 3 dB axial ratio (AR) bandwidth of 2.64 GHz (73.33%; 2.28⁻4.92 GHz). The measurement agrees well with simulation, which proves an excellent circularly polarized property. For verification, the mechanism of band improvement and circular polarization are presented, and the parametric study is carried out. Since, the proposed antenna is a simple design structure with broad impedance and AR bandwidth, which is a desirable feature as a candidate for various wireless communication systems. Because of the easy printed structure and scaling the dimension with broadband CP characteristics, the realized antenna does incorporate in a number of CP wireless communication applications.

8.
Sensors (Basel) ; 18(12)2018 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-30558191

RESUMEN

An experimental system for early screening of a breast tumor is presented in this article. The proposed microwave imaging (MI) system consists of a moveable array of nine improved negative-index metamaterial (MTM)-loaded ultrawideband (UWB) antenna sensor with incorporation of a corresponding SRR (split-ring resonator) and CLS (capacitively loaded strip) structure, in a circular array, the stepper motor-based array-mounting stand, the adjustable phantom hanging platform, an RF switching system to control the receivers, and a personal computer-based signal processing and image reconstruction unit using MATLAB. The improved antenna comprises of four-unit cells along one axis, where an individual unit cell integrates a balancing SRR and CLS pair, which makes the antenna radiation omnidirectional over the operating frequencies. The electrical dimensions of this proposed antenna are 0.28λ × 0.20λ × 0.016λ, measured at the lowest operating frequency of 2.97 GHz as the operating bandwidth of this is in between 2.97⁻15 GHz (134.82% bandwidth), with stable directional radiation pattern. SP8T 8 port switch is used to enable the eight receiver antennas to sequentially send a 3⁻8.0 GHz microwave signal to capture the backscattered signal by MATLAB software. A low-cost realistic homogeneous breast phantom with tumor material is developed and measured to test the capability of the imaging system to detect the breast tumors. A post-processing delay-multiply-and-sum (DMAS) algorithm is used to process the recorded backscatter signal to get an image of the breast phantom, and to accurately identify the existence and located area of multiple breast tumor tissues.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Fantasmas de Imagen , Algoritmos , Diseño de Equipo , Humanos , Microondas
9.
Sensors (Basel) ; 18(9)2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-30189684

RESUMEN

Microwave breast imaging has been reported as having the most potential to become an alternative or additional tool to the existing X-ray mammography technique for detecting breast tumors. Microwave antenna sensor performance plays a significant role in microwave imaging system applications because the image quality is mostly affected by the microwave antenna sensor array properties like the number of antenna sensors in the array and the size of the antenna sensors. In this paper, a new system for successful early detection of a breast tumor using a balanced slotted antipodal Vivaldi Antenna (BSAVA) sensor is presented. The designed antenna sensor has an overall dimension of 0.401λ × 0.401λ × 0.016λ at the first resonant frequency and operates between 3.01 to 11 GHz under 10 dB. The radiating fins are modified by etching three slots on both fins which increases the operating bandwidth, directionality of radiation pattern, gain and efficiency. The antenna sensor performance of both the frequency domain and time domain scenarios and high-fidelity factor with NFD is also investigated. The antenna sensor can send and receive short electromagnetic pulses in the near field with low loss, little distortion and highly directionality. A realistic homogenous breast phantom is fabricated, and a breast phantom measurement system is developed where a two antennas sensor is placed on the breast model rotated by a mechanical scanner. The tumor response was investigated by analyzing the backscattering signals and successful image construction proves that the proposed microwave antenna sensor can be a suitable candidate for a high-resolution microwave breast imaging system.

10.
Sensors (Basel) ; 18(12)2018 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-30513712

RESUMEN

A digit 8-shaped resonator inspired metamaterial is proposed herein for sensor applications. The resonator is surrounded by a ground frame and excited by a microstrip feedline. The measurement of the sensor can be performed using common laboratory facilities in lieu of using the waveguide, as the resonator, ground frame, and feedline are all on the same microstrip. To achieve metamaterial properties, more than one unit cell is usually utilized, whereas, in this work, a single cell was used to achieve the metamaterial characteristics. The properties of the metamaterial were investigated to find the relationship between the simulation and measurements. The proposed metamaterial sensor shows considerable sensitivity in sensor application. For the sensor application, FR4 and Rogers RO4350 materials were used as the over-layer. The sensor can measure dielectric thickness with a sensitivity of 625 MHz/mm, 468 MHz/mm, and 354 MHz/mm for the single over-layer, double over-layers, and multiple over-layers, respectively. The proposed prototype can be utilized in several applications where metamaterial characteristics are required.

11.
Sensors (Basel) ; 15(5): 11601-27, 2015 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-26007721

RESUMEN

This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.


Asunto(s)
Diagnóstico por Imagen/instrumentación , Microondas , Simulación por Computador , Diseño de Equipo , Modelos Teóricos , Reproducibilidad de los Resultados
12.
Biomol Ther (Seoul) ; 31(4): 425-433, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37035877

RESUMEN

During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

13.
J Family Med Prim Care ; 12(8): 1636-1643, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37767421

RESUMEN

Background: Chronic kidney disease (CKD), a leading public health problem, has potential risks and serious implications on the health of individuals and society at large. Few studies explored the factors that influence access to CKD care at the community level in rural areas of West Bengal. A qualitative study was planned among key stakeholders to explore their views and experiences and to identify the barriers and potential facilitators that influence access to CKD care at the primary care level. Methods: Total 23 stakeholders participated in the study. Seventeen in-depth interviews (IDIs) were conducted on a purposive sample of stakeholders (CKD patients, healthcare providers (HCPs) and health planners) and one focus group discussion (FGD) among six community health workers. The audio-recorded interviews were transcribed verbatim. The Lévesque's framework for access to care as modified by Jodie Bailie et al. was employed to construct interview guides and structure the initial codes. Thematic analysis was undertaken using QSR NVivo version 11 using both inductive and deductive approaches. Results: The major barriers to CKD care at patient level were poor knowledge and awareness of CKD and at the health system level was shortage of skilled staffs, diagnostics and medicines and fragmented referrals. The potential facilitators identified were educational activities to increase the awareness of CKD among HCPs and patients; provision of CKD-related supplies and a system-level approach to care coordination along with m-health-based care. Conclusions: Targeted CKD screening programs and CKD specific trainings may improve awareness of CKD. Additionally, stronger primary care infrastructure, availability of essential drugs and diagnostics and creating an efficient referral process for the quality CKD care are the need of the hour.

14.
J Family Med Prim Care ; 11(5): 1728-1733, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35800569

RESUMEN

Introduction: One of the goals of the National Population Policy 2000 was to stabilize the population at a level consistent with the requirement of national economy. Spacing methods are reversible methods of contraception. Vision FP2020 will build on policy of increasing focus on spacing services through voluntary adoption of family planning. With this background, the study was conducted to explore the spacing contraception behaviour among married women of reproductive age group. Methods: A descriptive cross-sectional study was conducted from July to August 2018 at a rural block of West Bengal. Four subcentres from a list of total 38 subcentres in the Bhatar block were selected by Simple random sampling (SRS). A list of currently married women of reproductive age group fulfilling the inclusion criteria was prepared and 10 women of each SC were chosen randomly. In-depth interviews were conducted among selected women and a focused group discussion was conducted involving the auxiliary nurse midwife (ANMs) to elicit reasons and barriers for contraceptive use from service providers' perspective. Results: The reasons for their current contraceptive choice were change in behaviour and, according to gender of the first baby, poor information, education, communication (IEC), personal preference, motivation by family members and health workers, religion and caste factors, fear and side effect for other methods, easy availability etc. Conclusion: The findings reinforce the need for targeted spacing contraception promotion that includes delivery of localized contraceptive services, increase of knowledge on safety and utility of spacing methods among eligible clients, their family members and local health workers.

15.
Phys Rev E ; 105(2-1): 024608, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35291112

RESUMEN

We consider binary suspension of rough, circular particles in two dimensions under athermal conditions. The suspension is subject to a time-independent external drive in response to which half of the particles are pulled along the field direction, whereas the other half is pushed in the opposite direction. Simulating the system with different magnitude of external drive in steady state, we obtain oppositely moving macroscopic lanes only for a moderate range of external drive. Below as well as above the range we obtain states with no lane. Hence we find that the no-lane state reenters along the axis of the external drive in the nonequilibrium phase diagram corresponding to the laning transition, with varying roughness of individual particles and external drive. Interparticle friction (contact dissipation) due to the roughness of the individual particle is the main player behind the reentrance of the no-lane state at high external drives.

16.
Sci Rep ; 12(1): 8495, 2022 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-35589758

RESUMEN

A couple ring enclosed circular geometric resonator (CRECGR) based dual-band polarization insensitive metamaterial (MM) with high effective medium ratio (EMR), and excellent absorptance is proposed in this study, which can be utilized as a sensor and absorber in the 5G sub-6 GHz frequency range. A circular geometry-based unique patch has been introduced in the proposed unit cell to achieve high polarization insensitive properties with excellent absorption for the 5G sub-6 GHz spectrum. The distinctive feature of this proposed CRECGR unit cell is its simple and unique structure with a high EMR of 11.13, polarization insensitive up to 180°, and epsilon negative (ENG) properties, including a negative refractive index and near-zero permeability for 5G sub-6 GHz applications. Furthermore, this designed unit cell yields excellent absorption properties with high quality factor. The designed MM unit cell is fabricated on low loss Rogers RT5880 printed media with an electrical dimension of 0.089λ × 0.089λ × 0.017λ. The performance of the designed CRECGR metamaterial is determined using Computer Simulation Technology (CST), Advanced Design Software (ADS), and measurements. The CRECGR unit cell offers dual resonances at 3.37 GHz and 5.8 GHz, covering the 5G sub-6 GHz band with ENG, near-zero permeability and negative index. The polarization insensitive properties of the unit cell were also investigated for maximum angle of incidence, which confirmed the identical response. The simulated outcome is verified by experiment with excellent accordance. Moreover, the unit cell performance with a complete backplane is explored, noting a maximum absorption of 99.9% for all normal and oblique incidence waves, suitable for sensing and antenna systems. In addition, the suggested unit cell sensing performance is evaluated using the permittivity-based sensing model. The proposed MM outperforms recent related studies in terms of polarization insensitivity up to 180°, high insensitive absorptivity, high EMR, and sensing applications. These features prove that the proposed CRECGR metamaterial is perfect for 5G Applications.

17.
Sci Rep ; 12(1): 12497, 2022 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-35864131

RESUMEN

This article presents a novel metamaterial (MTM) with a mirror symmetric resonator that exhibits multiple resonances of transmission coefficient covering the L, S, C, and X bands. The resonating patch is constructed on a low-loss Rogers (RT5880) substrate with a dimension of 20 × 20 × 1.575 mm3. It consists of four equal quartiles with each quartile made with interconnected split-ring resonators; the quartiles are in mirror symmetry with each other. The proposed MTM exhibits resonances at 1.98 GHz, 3.67 GHz, 4.74 GHz, 8.38 GHz, and 10.8 GHz, and electromagnetic characterization is performed through studies of permittivity, permeability, refractive index, and impedances. Power analysis is also performed, and the effect of polarized incident waves is studied. An electromagnetic characterization study reveals that the proposed MTM shows negative permittivity with near-zero permeability and refractive index. It also reveals very little power consumption in the vicinity of the resonances. The dielectric-based frequency tuning is studied by using different dielectric layers over the patch that provides good frequency tuning; this method provides flexibility for adjusting the resonance frequencies in accordance with the application demand. The measured result of the proposed unit cell with the dielectric layer is extracted using a vector network analyzer, and the results exhibit good similarity with the simulated ones. The above-mentioned properties, along with a good effective medium ratio (EMR) of 7.57 indicate that this MTM is suitable for frequency selective applications in microwave devices such as antenna performance improvement and sensing.

18.
Nanomaterials (Basel) ; 12(23)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36500876

RESUMEN

Researchers are trying to work out how to make a broadband response metamaterial absorber (MMA). Electromagnetic (EM) waves that can pass through the atmosphere and reach the ground are most commonly used in the visible frequency range. In addition, they are used to detect faults, inspect tapped live-powered components, electrical failures, and thermal leaking hot spots. This research provides a numerical analysis of a compact split ring resonator (SRR) and circular ring resonator (CRR) based metamaterial absorber (MMA) using a three-layer substrate material configuration for wideband visible optical wavelength applications. The proposed metamaterial absorber has an overall unit cell size of 800 nm × 800 nm × 175 nm in both TE and TM mode simulations and it achieved above 80% absorbance in the visible spectrums from 450 nm to 650 nm wavelength. The proposed MA performed a maximum absorptivity of 99.99% at 557 nm. In addition, the steady absorption property has a broad range of oblique incidence angle stability. The polarization conversion ratio (PCR) is evaluated to ensure that the MMA is perfect. Both TM and TE modes can observe polarization insensitivity and wide-angle incidence angle stability with 18° bending effects. Moreover, a structural study using electric and magnetic fields was carried out to better understand the MMA's absorption properties. The observable novelty of the proposed metamaterial is compact in size compared with reference paper, and it achieves an average absorbance of 91.82% for visible optical wavelength. The proposed MMA also has bendable properties. The proposed MMA validation has been done by two numerical simulation software. The MMA has diverse applications, such as color image, wide-angle stability, substantial absorption, absolute invisible layers, thermal imaging, and magnetic resonance imaging (MRI) applications.

19.
Front Pharmacol ; 13: 943879, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36059993

RESUMEN

Accumulation of glucose/sugar results in the formation of reactive di-carbonyl compounds such as MGO and GO that interact with several amino acids and proteins to form toxic advanced glycation end products (AGEs). Induction of AGEs breakdown can control symptoms and severity in T2DM and other related complications like NAFLD where AGEs are the key players. Therefore, an AGE cross-link breaker has been suggested for preventing the onset/progression of NAFLD. In this study, we reported novel synthetic naphthalene-2-acyl thiazolium derivatives (KHAGs). Among synthesized KHAG derivatives, we observed that a novel KHAG-04, a 1,4-dimethoxynaphthalen-2-acyl thiazolium salt which is an analog of alagebrium, dramatically cleaves MGO/GO-AGE cross-links, and it also inhibited inflammation by lowering the level of nitric oxide production and IL-1ß and TNF-α secretion in LPS and/or MGO-AGE-activated macrophage. Moreover, it also reduced FFA and MGO-AGE-induced lipogenesis in Hep-G2 cells. In mice, KHAG-04 significantly reduced the level of glyoxal in the liver, which was induced by DMC. Furthermore, KHAG-04 treatment significantly reduced blood glucose levels, lipid accumulation, and inflammation in the NAFLD/T2DM animal model. Novel KHAG-04-mediated induction of AGEs breakdown could be the possible reason for its anti-inflammatory, antihyperglycemic, and anti-lipidemic effects in cells and NAFLD in the T2DM animal model, respectively. Further research might explore the pharmacological efficacy and usefulness and consider the ability of this compound in the treatment strategy against various models of NAFLD in T2DM where MGO/GO-AGEs play a key role in the pathogenesis.

20.
Sci Rep ; 12(1): 9433, 2022 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-35676407

RESUMEN

This work proposes a compact metasurface (MS)-integrated wideband multiple-input multiple-output (MIMO) antenna for fifth generation (5G) sub-6 GHz wireless communication systems. The perceptible novelty of the proposed MIMO system is its wide operating bandwidth, high gain, lower interelement gap, and excellent isolation within the MIMO components. The radiating patch of the antenna is truncated diagonally with a partially ground plane, and a metasurface has been employed for enhancing the antenna performance. The suggested MS integrated single antenna prototype has a miniature dimension of 0.58λ × 0.58λ × 0.02λ. The simulated and measured findings demonstrate a wideband characteristic starting from 3.11 to 7.67 GHz including a high realized gain of 8 dBi. The four-element MIMO system has been designed by rendering each single antenna orthogonally to one another while retaining compact size and wideband properties between 3.2 and 7.6 GHz. The suggested MIMO prototype has been designed and fabricated on a low loss Rogers RT5880 substrate with a miniature dimension of 1.05λ × 1.05λ × 0.02λ and its performance is evaluated using a suggested 10 × 10 array of a square enclosed circular split ring resonators within the same substrate material. The inclusion of the proposed metasurface with a backplane significantly reduces antenna backward radiation and manipulates the electromagnetic field, thus improving the bandwidth, gain and isolation of MIMO components. The suggested 4-port MIMO antenna offers a high realized gain of 8.3 dBi compared to existing MIMO antennas with an excellent average total efficiency of 82% in the 5G sub-6 GHz spectrum and is in good accordance with measured results. Furthermore, the developed MIMO antenna exhibits outstanding diversity characteristics in respect of envelope correlation coefficient (ECC) less than 0.004, diversity gain (DG) close to 10 dB (> 9.98 dB) and high isolation between MIMO components (> 15.5 dB). Therefore, the proposed MS-inspired MIMO antenna substantiates its applicability for 5G sub-6 GHz communication networks.


Asunto(s)
Procedimientos Quirúrgicos Refractivos , Tecnología Inalámbrica , Diseño de Equipo
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