Low profile high gain RHCP antenna for L-Band and S-Band using rectangular ring metasurface with backlobe suppression.

In this reported work a single feed, miniaturized, dual layer, and low profile antenna is presented for 1.575GHz frequency band. The proposed antenna offers high gain, lower noise bandwidth, with better sensitivity and range. The ground choke technique is used for back lobe suppression. The prototype is fabricated on FR 4 substrate using manual fabrication technique. This offers an inexpensive and readily available fabrication. Therefore, fabricated antenna is small size, low cost, easily fabricated and tested for satellite communication. The antenna comprises of two layers, containing a patch radiator and a Metasurface layer with 3x3 rectangular ring resonators. The layers are separated using foam with a 12mm width. The proposed prototype is radiating at 1.575GHz and 2.33GHz with an overall dimension of 85.6 x 68.4 x 15.204 mm. The developed antenna provides a gain of 5.9 dBi. The simulated results are verified using VNA and anechoic chamber testing. Moreover, the developed antenna has been successfully tested for L-Band Satellite communication in real time scenario without any LNA. Higher Gain due to Metasurface increase the efficiency of the system. The promising results indicate the aptness of the developed antenna for real-world applications of L-Band and S-Band.

Optimal designing of grid-connected microgrid systems for residential and commercial applications in Pakistan.

Conventional energy sources (CESs) are currently serving most of the global energy demands, but they will be substantially depleted as moving towards the end of this decade. The generation of electricity from such sources is causing the emission of greenhouse gases that is resulting in deleterious effect on the environment along with changing climatic and energy patterns of the planet. Therefore, the world is heading toward decentralization, and microgrids are playing a key role in this process. The advantages of renewables, which are acknowledged globally as benign, eco-friendly, economical, and inexhaustible resources available worldwide, are to credit for such a massive surge in the utilization of renewable resources in microgrid technology. Despite having an enormous renewable energy potential, Pakistan spends a sizable portion of its budget on energy imports of coal, oil, and liquefied natural gas, however, with good planning, current energy crises might be eliminated or at least mitigated to a greater extent, assuring energy security, economic prosperity, and lower carbon emissions inside the country. This study considers the optimal component planning in a grid-connected microgrid with five objectives to achieve that are to reduce the cost of energy, increase the renewable share, cut greenhouse gas emissions, enhance the reliability of power supply and to make electricity generation sustainable in the long run for the country. Different solar PV capacities are tested against the energy cost, renewable share and emission of greenhouse gases in order to attain the trade-off. The cost of energy is minimized by 92.47%, renewable share rises to 85%, and CO2 emissions are decreased by 48% for residential application. In the case of commercial application, however, the cost of energy is lowered by 48.52%, the renewable energy share rises to 71.1%, and CO2 emissions are reduced by 61% through incorporating solar PV into the current power system.

Heparin purification by expanded bed anion exchange in a countercurrent chromatography column.

In this study, an expanded bed anion exchange in a countercurrent chromatography column (EB-CCC) technique for separation and purification of heparin, an anticoagulant and antithrombotic glycosaminoglycan, is reported for the first time. A comparative evaluation of the EB-CCC technique with the conventional fixed bed column chromatography (FBCC) revealed its effectiveness in improving adsorption at high flow rates and reducing separation time. A significantly higher maximum adsorption (91.66%) was exhibited by EB-CCC in comparison with FBCC (45.16%) at the eluent flow rate of 1 mL·min-1. Similarly, the experimental adsorption capacity of heparin was enhanced by 1.69, 2.06 and 2.58 times in the case of EB-CCC at the flow rates of 1, 2 and 5 mL·min-1, respectively. Moreover, the directly proportional amplification of double loaded resin and double column volume was demonstrated at an EB-CCC rotational speed of 300 rpm and a flow rate of 2 mL·min-1, and the experimental adsorption capacity was observed to increase from 66.42 to 136.48 mg·g-1 after amplification. Heparin purified by EB-CCC displayed higher potency (216.09 ± 11.89 IU·mg-1) as compared to FBCC (205.51 ± 7.90 IU·mg-1) and the initial crude heparin 134.17 ± 4.12 IU·mg-1. Furthermore, comparing to the purified heparin by FBCC, heparin purified by EB-CCC had low molecular weight, high FXa/FIIa, superior anticoagulation effect and enhanced suitability as an exogenous anticoagulant.

Deciphering the Variants Located in the MIR196A2, MIR146A, and MIR423 with Type-2 Diabetes Mellitus in Pakistani Population.

MicroRNAs (miRNAs) are small non-coding RNA molecules that control the post-transcriptional gene expression. They play a pivotal role in the regulation of important physiological processes. Variations in miRNA genes coding for mature miRNA sequences have been implicated in several diseases. However, the association of variants in miRNAs genes with Type 2 Diabetes Mellitus (T2DM) in the Pakistani population is rarely reported. Therefore, the current study was designed to investigate the association of rs11614913 T/C (MIR196A2), rs2910164 G/C (MIR146A), and rs6505162 C/A (MIR423) in clinicopathological proven T2DM patients and gender-matched healthy controls. The tetra-primer amplification refractory mutation system-polymerase chain (ARMS-PCR) reaction method was used to determine the genotypes and to establish the association of each variant with T2DM through inherited models. In conclusion, the present study showed that variants rs11614913 T/C and rs2910164 G/C were linked with the risk of T2DM. The data suggested that rs11614913 T/C and rs2910164 G/C could be considered as novel risk factors in the pathogenesis of T2DM in the Pakistani population.

Antioxidant Potential of Physicochemically Characterized Gracilaria blodgettii Sulfated Polysaccharides.

Marine rhodophyte polysaccharides have a wide range of described biological properties with nontoxic characteristics, and show great potential in prebiotics and the functional foods industries. However, there is a virtual lack of Gracilaria blodgettii polysaccharides (GBP) profiling and their bioactivities. This study was designed while keeping in view the lack of physical and chemical characterization of GBP. This polysaccharide was also not previously tested for any bioactivities. A linear random coil conformation was observed for GBP, which was found to be a polysaccharide. A significant sulfate (w/w, 9.16%) and 3,6-anhydrogalactose (AHG, w/w, 17.97%) content was found in GBP. The significant difference in its setting (27.33 °C) and melting (64.33 °C) points makes it resistant to increasing heat. This, in turn, points to its utility in industrial scale processing and in enhancing the shelf-life of products under high temperatures. A radical scavenging activity of 19.80%, 25.42% and 8.80% was noted for GBP (3 mg/mL) in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (ABTS) and hydroxyl radical (HO) scavenging assays, respectively. Therefore, the findings suggest that Gracilaria blodgettii polysaccharides display a good antioxidant potential and may have potential applications in the functional food industry.

Advances in Separation and Purification of Bioactive Polysaccharides through High-speed Counter-Current Chromatography.

Polysaccharides, with an extensive distribution in natural products, represent a group of natural bioactive substances having widespread applications in health-care food products and as biomaterials. Devising an efficient system for the separation and purification of polysaccharides from natural sources, hence, is of utmost importance in the widespread applicability and feasibility of research for the development of polysaccharide-based products. High-speed counter-current chromatography (HSCCC) is a continuous liquid-liquid partitioning chromatography with the ability to support a high loading amount and crude material treatment. Due to its flexible two-phase solvent system, HSCCC has been successfully used in the separation of many natural products. Based on HSCCC unique advantages over general column chromatography and its enhanced superiority in this regard when coupled to aqueous two-phase system (ATPS), this review summarizes the separation and purification of various bioactive polysaccharides through HSCCC and its coupling to ATPS as an aid in future research in this direction.

Comparison of Physicochemical Characteristics and Macrophage Immunostimulatory Activities of Polysaccharides from Chlamys farreri.

To address the structure-activity relationship of Chlamys farreri polysaccharides on their immunostimulatory efficacy, two polysaccharides (CFP-1 and CFP-2) were extracted from Chlamys farreri by hot water extraction, and separated through column chromatography. The isolated CFPs were chemically analyzed to clarify their physicochemical characteristics and cultured with murine macrophage RAW264.7 cells, in order to evaluate their immunostimulatory efficacy. Despite the fact that both CFP-1 and CFP-2 were mainly comprised of glucose lacking the triple-helix structure, as revealed through preliminary physicochemical analyses, obvious differences in regard to molecular weight (Mw), glucuronic acid content (GAc) and branching degree (BD) were observed between CFP-1 and CFP-2. In in vitro immunostimulatory assays for macrophage RAW264.7 cells, it was demonstrated that CFP-2 with larger Mw, more GAc and BD could evidently promote phagocytosis and increase the production of NO, IL-6, TNF-α and IL-1ß secretion, by activating the expression of iNOS, IL-6, TNF-α and IL-1ß genes, respectively. Hence, CFP-2 shows great promise as a potential immunostimulatory agent in the functional foods and nutraceutical industry, while CFP-1, with lower molecular weight, less GAc and BD, displays its weaker immunostimulatory efficacy, based on the indistinctive immunostimulatory parameters of CFP-1.

Physicochemical characterization and antioxidant activity of sulphated polysaccharides derived from Porphyra haitanensis.

This study was designed to fully characterize Porphyra haitanensis polysaccharides, and to evaluate their antioxidant activity. The polysaccharides primarily contained galactose and 3,6-anhydrogalactose in a molar ratio of 1.2:1.0, respectively and sulfate content about 3.8%. The molecular weight of polysaccharides is 2.5 × 105 Da. Scanning electron microscopy and atomic force microscopy of the polysaccharides pointed towards an irregular network with more or less hexagonal and a few rectangular pores. The chemical structure was confirmed through Fourier transform infrared spectroscopy, and 1D and 2D nuclear magnetic resonance structural characterization wherein â†’ 4-3,6-anhydro-α-L-galactopyranose-(1 â†’ 3)-ß-D-galactopyranose segments. The extracted polysaccharides revealed relatively high 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (53.16% at 2 mg/mL), moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging efficacy (34.63% at 2 mg/mL), and low hydroxyl radical scavenging potential (23.80% at 2 mg/mL). Further purification of these polysaccharides, hence, is advised for their potential role as antioxidants in the food, pharmaceutical and cosmeceutical industry.

Pumpkin polysaccharides: Purification, characterization and hypoglycemic potential.

The separation and purification of pumpkin polysaccharide by aqueous two-phase system combined with DEAE cellulose-52 column chromatography. There are two purified polysaccharides, neutral fractions (ATPS-PP-1) (7.67 kDa) and acidic fractions (ATPS-PP-2) (8.83 kDa), were obtained from pumpkin powder which were subsequently characterized structurally. The backbone of ATPS-PP-1 comprised of (1 → 3)-linked-Glcp having branching points at O-3 of (1 → 3,4)-linked-Glcp with terminal Glcp as side chain. ATPS-PP-2, on the other hand, comprised of 1 → Glcp, (1 → 3)-linked-Galp, (1 → 6)-linked-Glcp, (1 → 3,6)-linked-Glcp and (1 → 4)-linked-Glcp as backbone. And ATPS-PP-1with small molecular weight and the backbone consisted of (1 → 3) glycosidic linkages has better hypoglycemic activity. Significant protection was conferred on streptozotocin damaged islet ß cells by ATPS-PPs (neutral fractions and acidic fractions). Such protective effect was demonstrated by ATPS-PPs' ability to lower Nitric oxide levels by inhibiting NF-κB mRNA overexpression and afterwards down regulation iNOS mRNA expression, eventually minimizing cell oxidative damage caused by STZ and restoring the normal levels of superoxide dismutase.

Physicochemical characterization of Gracilaria chouae sulfated polysaccharides and their antioxidant potential.

A complete absence of the physicochemical characterization of Gracilaria chouae polysaccharides (GCP) and its corresponding bioactivities urged the need for this study. It was found that GCP is a heteropolysaccharide which exists in linear random coil conformation. It contained a sulfate content of 7.9% in addition to 52.63% total sugar content and 9.62% galacturonic acid. Galactose and 3,6-anhydrogalactose were found in a molar ratio of 1.0:0.6. Its setting and melting points were determined as 41.3 and 71.7 °C, respectively, which makes it a suitable candidate for industrial processing where further heating is required and/or where the end-product needs to have extended shelf life in hot climate. GCP demonstrated 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis and hydroxyl radical scavenging activity (36.86, 27.42 and 19.07% at 3 mg·ml-1). Moreover, the results also suggested its potential use as a prebiotic due to its perceived high fermentability.

Preparation and evaluation of Bletilla striata polysaccharide/carboxymethyl chitosan/Carbomer 940 hydrogel for wound healing.

This study aims at developing an effective, safe and economic hydrogel, with wound healing ability, by making use of polysaccharides. Bletilla striata polysaccharide (Bsp) and the bioactive natural polymers, carboxymethyl chitosan (CMC), were physically blended with Carbomer 940 (CBM940) in order to promote gel-forming and improve water retention. FT-IR displayed hydrogen bonding between CBM940 and CMC played a role in physical gel formation. XRD showed broad and weak intensity peak of Bsp/CMC/CBM940 hydrogel. SEM, rheological measurement and water loss test revealed that the best hydrogel with optimum characteristics in relation to porous structure, elastic property and water retention could be obtained by mixing Bsp, CMC and CBM940 in a ratio of 4:1:1. In vitro studies proved that the Bsp/CMC/CBM940 hydrogel possessed blood compatibility. M293T cells viability was over 85% via MTT assay which revealed non-cytotoxicity. Hydroxyl radical scavenging property highly improved while Bsp combined with CMC. The full-thickness wound experiment illustrated 71.64 ±â€¯6.64% and 83.80 ±â€¯5.56% wound healing rates for Bsp4:CMC1:CBM9401 hydrogel on Day 7 and Day 14, respectively, which showed no significant differences (p > 0.05) in comparison to the positive control. Histological observation expressed epithelization, dense collagen fiber and neovascular formation in hydrogel group on Day 14. Bsp/CMC/CBM940 hydrogel can, hence, serve as an attractive candidate for healing wounds.

ATPS: "Aqueous two-phase system" as the "answer to protein separation" for protein-processing food industry.

Every individual needs food for its nutritional value and flavor while the economic growth of a nation depends on a thriving profit-generating industry. The food industry caters to both needs in an efficient manner. Proteins can rightly be considered as the driving force behind the overwhelming success of this industry. However, purification of proteins is not an easy undertaking due to their intricate nature while presently employed procedures for this purpose, regrettably, are both costly, and labor- and time-intensive in addition to being unsettling on proteins structural conformity. ATPS has accumulated a lot of interest from the scientific community due to its mild operating conditions, high recovery yield, ease of scaling it up, and its cost-effective and environment friendly nature. This review tries to amass some accounts concerning the utility of ATPS for the separation and purification of proteins. Some auspicious clues in this regard can be witnessed along with a few loopholes which need to be addressed before this technique can truly demonstrate its potential vis-à-vis industrial protein purification. Overall, a polymer - salt (citrates in particular) ATPS with an added inert supplementary salt can be regarded as a better option for purifying proteins.

Seizure forecasting using single robust linear feature as correlation vector of seizure-like events in brain slices preparation in vitro.

OBJECTIVE: Epilepsy is a neurological disorder affecting 50 million individuals globally. Modern research has inspected the likelihood of forecasting epileptic seizures. Algorithmic investigations are giving promising results for seizure prediction. Though mostly seizure prediction algorithm uses pre-ictal (prodromal symptoms) events for prediction. On the contrary, prodromal symptoms may not necessarily be present in every patient or subject. This paper focuses on seizure forecasting regardless of the presence of pre-ictal (prodromal symptoms) using the single robust feature with maximum accuracy. Method: We evaluated datasets having 4-aminopydine induced seizure-like events rat's hippocampa slices and cortical tissue from pharmacoresistant epilepsy patients. The proposed methodology applies the Discrete Wavelet Transform (DWT) at levels 1-5 utilizing 'Daubechies-4'. Linear Discriminant classifier (LDC), Quadratic Discriminant Classifier (QDC) and Support Vector Machine (SVM) were used to classify each signal using eight discriminative features. Results: Classifier performance was assessed by parameters like true detections (TD), false detection (FD), accuracy (ACC), sensitivity (SEN), specificity (SPF), and positive predicted value (PPC), negative predicted value (NPV). Highest classification feature was selected as a seizure forecasting correlation vector and decision rule was formulated for seizure forecasting. Correlation vector served as a forecaster for current EEG activity. Proposed decision rule forecasted ongoing signal activity towards possible seizure condition true or false. The suggested framework revealed forecasting of ictal events at 10 seconds before the actual seizure. Conclusion: It is worth mentioning that the proposed study utilized a single linear feature to predict seizures precisely. Moreover, utilization of single feature encouraged in subsiding system complexity, processing delays, and system latency.

Marine Mollusks: Food with Benefits.

The extremely vast biodiversity represented by marine mollusks alongside their widespread utility as a source of food and their high nutritional value has aroused great interest from the scientific community. Furthermore, they can be caught with ease, and their commercial breeding and farming is rampant. This article comprehends the global availability of these organisms, their pretreatment and handling procedures, and their health-promoting potential with a focus on their antiviral, anti-inflammatory, and antimicrobial properties. The emphasis herein is on their potential use in the food and nutraceutical industry. In addition, mollusks consumption as part of everyday diet can also be helpful in avoiding many ailments as they are rich in vital nutrients and active secondary metabolites, as well as have the ability to enhance immune response. Moreover, the available literature suggests that normal cooking practices have no notable adverse effects on their nutritional value and they retain certain bioactivities even after the action of digestive enzymes. Though mollusks have been widely studied in relation to the health-promoting effects reviewed here, there is still more scope for further research in this direction in order to fully utilize this enormous source of food and nutraceuticals.

Oligosaccharides Derived from Red Seaweed: Production, Properties, and Potential Health and Cosmetic Applications.

Because of their potential use as functional ingredients in human nutrition, oligosaccharides derived from natural sources are receiving paramount consideration. Red seaweed, a proven rich source of agar and carrageenan, is one of the most abundantly present sources of such oligosaccharides. Agaro-oligosaccharides (AOS) and carrageenan-oligosaccharides (COS) are produced from agar and carrageenan, respectively, through chemical and enzymatic hydrolyses. Enzymatic hydrolysis of agar and carrageenan into oligosaccharides is preferred in industrial production because of certain problems associated with chemical hydrolysis, including the release of high amounts of monosaccharides and undesirable toxic products, such as furfural. AOS and COS possess many biological activities, including prebiotic, immuno-modulatory, anti-oxidant, and anti-tumor activities. These activities are related to their chemical structure, molecular weight, degree of polymerization, and the flexibility of the glycosidic linkages. Therefore, the structure⁻function relationship and the mechanisms occurring during the specific biological applications of AOS and COS are discussed herein. Moreover, the chromatographic separation, purification, and characterization of AOS and COS are also part of this review. This piece of writing strives to create a new perspective on the potential applications of AOS and COS in the functional food and pharmaceutical industry.

Screening of leaves extracts from Calamus aromaticus for their antimicrobial activity by disc diffusion assay.

The current research investigates the anti-microbial activities of different solvent extracted samples from the leaves of Calamus aromaticus against Gram positive, Gram negative bacteria and fungi using 500, 1000 and 2000 µg disc-1 concentrations. Escherichia coli, Citorbacter freundii and Candida albicans showed resistivity to crude methanolic extract and the same microbes were more susceptible to water extracted fractions. Maximum activity was measured by hexane extracted fractions against Pseudomonas aeruginosa, Bacillus subtilis and Xanthomonas campestris and minimum growth inhibition by water extracted fractions. Maximum growth of Klebsiella pneumoniae and Staphylococcus aureus was measured by ethyl acetate fraction. Majority of the tested microbes were resistant to water and butanol extracted fractions. Staphylococcus aureus revealed maximum susceptibility among gram positive bacteria and Bacillus subtilis showed minimum. Among Gram negative bacteria, Citorbacter freundii was more susceptibile while Xanthomonas campestris revealed resistively.