12 research outputs found
Antiglycation, antiplatelets aggregation, cytotoxic and phytotoxic activities of Nepeta suavis
Nepeta suavis Stapf. (Lamiaceae), one of the ignored species for testing biological activities, was studied. In present research, the Nepeta suavis fractions: chloroform (FC), ethyl acetate (FE) and aqueous (FW) were evaluated for platelet aggregation, antiglycation, cytoxicity, and phytotoxicity. FE showed 65.60% antiglycation activity against the protein glycation while the other fractions showed less than 50% inhibitory potential. The FW inhibited arachidonic acid (AA) and platelet activating factor (acetyl-glyceryl-ether-phosphorylcholine, PAF) induced platelet aggregation. FE showed significant cytotoxicity against brine shrimp larvae with LD50 of 41.3 μg/ml. Phytotoxic studies of FC, FE and FW against Lemna minor showed 77.5-100% inhibitory effects at 1000 μg/ml. However, at lower concentration (10 μg/ml) enhancing effects were observed in FC and FE, as compared to control. FW remained in a uniform pattern of inhibitory effects in all three concentrations (10,100 and 1000 μg/ml). FE showed highest inhibitory activities against formation of glycation, while FW showed significant inhibitory effects against platelet aggregation and Lemna minor. Both of these fractions are recommended for further study to identify and isolate active chemical compounds.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Highly Compact GCPW-Fed Multi-Branch Structure Multi-Band Antenna for Wireless Applications
In this work, we present a highly compact multi-branch structure multi-band antenna with a grounded coplanar waveguide
(GCPW)-fed structure printed on 26 ×13 ×1.6 mm3 sized FR-4 substrate having dielectric constant r of 4.3 and loss tangent of
0.02. In the proposed antenna, ve branches are extended from the main radiator to provide multi-band behavior. Two branches
are introduced at the upper end of the main radiator, e ectively covering the lower bands, while the other three branches are
introduced near the center of the main radiator to extend operation to higher bands. e designed antenna covers ve di erent
bands: 2.4 GHz, 4.5 GHz, 5.5 GHz, 6.5 GHz, and 7.8 GHz, with respective gain values of 1.34, 1.60, 1.83, 1.80, and 3.50 dBi and
respective radiation e ciency values of 90, 88, 84, 75, and 89%. e antenna shows a good impedance bandwidth, ranging from
170MHz to 3070 MHz. e proposed antenna is simulated in CST Microwave Studio, while its performance is experimentally
validated by the fabrication and testing process. e antenna has potential applications for IoT, sub-6 GHz 5G and WLAN (both
enablers for IoT), C-band, and X-band services.Dr. Mohammad Alibakhshikenari acknowledges support
from the CONEX-Plus programme funded by Universidad
Carlos III de Madrid and the European Union’s Horizon
2020 research and innovation programme under the Marie
Sklodowska-Curie grant agreement No. 801538
Effect of Centaurea pullata Methanolic Extract on the Growth of Portulaca oleracea
Phytotoxicity or allelopathy means poisonous results by a composite onplantgrowth, composites may be trace metals, pesticides salinity or phytotoxins. Some of the medicinal plants have phytotoxic activities which inhibit the growth of weeds and unwanted plants which are not of our desire. The present study is aimed to investigate the phytotoxic assessment of Centaurea pullata methanolic extract (CPME) roots. Dried plant were ground and extracted with methanol to prepare methanol crude extract. In-vitro phytotoxicity activity was conducted using these methanolic extracts as per standard procedures. The inhibitory effect of Centaurea pullata extract is tested on stalk and root of Portulaca oleracea and using four concentrations (3, 1.5, 0.75 and 0.37mg/ml) of plant extract and distal water in control. The result is noted on 5th and 10th days. The results obtained from these experiments showed that the crude methanolic extract of Centaurea pullata slightly inhibits the roots and shoots of Portulaca oleracea seeds as compared to the control plate which was not treated by the above mentioned sample extracts shown in Figures as. From the results obtained that, Phytotoxicity activity of Centaurea pullata methanolic extract showed non-significant results. Purification and in vivo studies of these plant are required for further verification
Effect of Centaurea pullata Methanolic Extract on the Growth of Portulaca oleracea
Phytotoxicity or allelopathy means poisonous results by a composite onplantgrowth, composites may be trace metals, pesticides salinity or phytotoxins. Some of the medicinal plants have phytotoxic activities which inhibit the growth of weeds and unwanted plants which are not of our desire. The present study is aimed to investigate the phytotoxic assessment of Centaurea pullata methanolic extract (CPME) roots. Dried plant were ground and extracted with methanol to prepare methanol crude extract. In-vitro phytotoxicity activity was conducted using these methanolic extracts as per standard procedures. The inhibitory effect of Centaurea pullata extract is tested on stalk and root of Portulaca oleracea and using four concentrations (3, 1.5, 0.75 and 0.37mg/ml) of plant extract and distal water in control. The result is noted on 5th and 10th days. The results obtained from these experiments showed that the crude methanolic extract of Centaurea pullata slightly inhibits the roots and shoots of Portulaca oleracea seeds as compared to the control plate which was not treated by the above mentioned sample extracts shown in Figures as. From the results obtained that, Phytotoxicity activity of Centaurea pullata methanolic extract showed non-significant results. Purification and in vivo studies of these plant are required for further verification
Heat transfer analysis of generalized second-grade fluid with exponential heating and thermal heat flux
Abstract The aim of present work is to apply the Caputo–Fabrizio fractional derivative in the constitutive equations of heat transfer. Natural convection flow of an unsteady second grade fluid over a vertical plate with exponential heating is discussed. The generalized Fourier law is substituted in temperature profile. A portion of the dimensionless factors are utilized to make the governing equations into dimensionless structures. The solutions for temperature and velocity profiles of Caputo–Fabrizio model are acquired through the Laplace transform method. These solutions are greatly affected through the variation of different dimensionless variables like Prandtl number, Grashof number, and second-grade fluid parameter. Finally, the influence of embedded parameters is shown by plotting graphs through Mathcad. From the graphical results it is concluded that, the temperature of the fluid decreases with the increasing values of the Prandtl number and Second grade fluid parameter and increases with the passage of time. The velocity of the fluid increases with increasing values of the Grashof number, second grade parameter and time while decreases with increasing values of fractional parameter and Prandtl number
Pharmacological evaluation of methanolic extract of Cyperus scariosus
The present study is aimed to investigate the phytochemical screening and biological activities of methanolic extract of Cyperus scariosus roots. Dried plant was grounded and extracted with methanol to prepare methanol crud extract. In vitro biological tests were conducted using this methanolic extracts according to the standard procedure. 100% death rate of brine shrimp was perceived at 3 mg/mL of plant extract after 72 hours. The extract showed action against Aspergillus flavius i.e. 90% followed by A. niger (91%) while the highest activity was shown against A. fumegatrus (94%). Important scavenging results were detected during scavenging of free radicals viz; 92.2% against DPPH, 82.2% to ABTS, 75.8% to hydrogen peroxide, 88.1% to ?-carotene, 86.1% to hydroxyl radical and 89.4% against phosphomolybdate at 3 mg/mL were obtained. The results obtained in this study point out that extract showed significant biological activities which might be due to the presence of bioactive constituents
Design and Experimental Analysis of Multiband Frequency Reconfigurable Antenna for 5G and Sub-6 GHz Wireless Communication
A low-profile frequency reconfigurable monopole antenna operating in the microwave frequency band is presented in this paper. The proposed structure is printed on Flame Retardant-4 (FR-4) substrate having relative permittivity of 4.3 and tangent loss of 0.025. Four pin diode switches are inserted between radiating patches for switching the various operating modes of an antenna. The proposed antenna operates in five modes, covering nine different bands by operating at single bands of 5 and 3.5 GHz in Mode 1 and Mode 2, dual bands (i.e., 2.6 and 6.5 GHz, 2.1 and 5.6 GHz) in Mode 3 and 4 and triple bands in Mode 5 (i.e., 1.8, 4.8, and 6.4 GHz). The Voltage Standing Waves Ratio (VSWR) of the presented antenna is less than 1.5 for all the operating bands. The efficiency of the designed antenna is 84 % and gain ranges from 1.2 to 3.6 dBi, respectively, at corresponding resonant frequencies. The achieve bandwidths at respective frequencies ranges from 10.5 to 28%. The proposed structure is modeled in Computer Simulation Technology microwave studio (CST MWS) and the simulated results are experimentally validated. Due to its reasonably small size and support for multiple wireless standards, the proposed antenna can be used in modern handheld fifth generation (5G) devices as well as Internet of Things (IoT) enabled systems in smart cities
A Pentaband Compound Reconfigurable Antenna for 5G and Multi-Standard Sub-6GHz Wireless Applications
This work proposes a low-profile, printed antenna that offers pattern and frequency reconfiguration functionalities printed on FR-4 substrate with a size of 46 × 32 × 1.6 mm3. The proposed antenna can operate in five different frequency bands, each one identified as a Mode, wherein there are possibilities of pattern reconfiguration. The frequency and pattern reconfigurability are made possible through 12 p-i-n diode switches (S1 to S12). The former is enabled through the switches S1 to S4 within the radiating patch, hence effectively controlling the resonant bands of the antenna; the latter is made possible through main lobe beam steering, enabled by the rest of the eight switches (S5 to S12), loaded in split parasitic elements designed on both sides of the radiator. The proposed antenna operates in the 5 GHz (4.52–5.39 GHz) band when all switches are OFF. When S1 is ON, the operating band shifts to 3.5 GHz (2.96–4.17 GHz); it changes to a 2.6 GHz (2.36–2.95 GHz) band when S1 and S2 are ON. When S3 is also turned ON, the antenna shifts to the 2.1 GHz Band (1.95–2.30 GHz). When S1–S4 are ON, the operating band shifts to a 1.8GHz (1.67–1.90 GHz) band. In all these bands, the return loss remains less than −10 dB while maintaining good impedance matching. At each operating band, the ON/OFF states of the eight p-i-n diode switches (S5 through S12) enable beam steering. The proposed antenna can direct the main beam in five distinct directions at 3.5GHz, 2.6 GHz, and 2.1 GHz bands, and three different directions at 5 GHz and 1.8 GHz bands. Different 5G bands (2.1, 2.6, 3.5, and 5) GHz, which fall in the sub 6GHz range, are supported by the proposed antenna. In addition, GSM (1.8 GHz), UMTS (2.1 GHz), 4G-LTE (2.1 GHz and 2.6 GHz), WiMAX (2.6 GHz and 3.5 GHz) and WLAN (5 GHz) applications are also supported by the proposed antenna, which is a candidate for handheld 5G/4G/3G devices
Design and Experimental Analysis of Multiband Compound Reconfigurable 5G Antenna for Sub-6 GHz Wireless Applications
In this paper, a printed low-profile antenna with frequency and pattern reconfigurable functionality is designed in three modes. Each mode operates at different frequency bands and has several options available for pattern reconfiguration in these bands. The proposed antenna consists of eight pin-diode switches (S1 to S8). The switches S1 and S2, installed in the radiating patch, are used for frequency reconfigurability to control the operating bands of the antenna. The rest of the six switches (S3, S4, S5, S6, S7, and S8), loaded in the stubs on the rear side of the antenna, are used for pattern reconfiguration to control the main lobe beam steering. When all switches are off, the proposed antenna operates in a wideband mode, covering the 3.82-9.32 GHz frequency range. When S1 is on, the antenna resonates in the 3.5 GHz (3.09-4.17 GHz) band. When both S1 and S2 are on, the resonant band of the antenna is shifted to 2.5 GHz band (2.40-2.81 GHz). A very good impedance matching with a return loss of less than -10 dB is attained in these bands. The beam steering is done at each operating frequency by controlling the on and off states of the six pin-diode switches (S3, S4, S5, S6, S7, and S8). Depending on the state of the switches, the antenna can direct the beam in seven distinct directions at 4.2 GHz, 4.5 GHz, and 5 GHz. The main beam of the radiation pattern is steered in five different directions at 5.5 GHz, 3.5 GHz, and 2.6 GHz operating bands for the given state of the mentioned switches. The proposed antenna supports several sub-6 GHz 5G bands (2.6 GHz, 3.5 GHz, 4.2 GHz, 4.5 GHz, and 5 GHz) and can be used in handheld 5G devices