Effects Of Active Components Research Articles

Design of Multiband, Reconfigurable Coplanar Meander Antenna for WLAN Applications

This paper presents the implementation of Reconfigurable, Planar Meander Antenna operates at 2.45 GHz and 5.12 GHz for WLAN applications. In the proposed work the planar meander antenna is designed using FR4 substrate. In the meander antenna the varactor diodes are incorporated in the appropriate arm positions to achieve reconfigurability. In this, reconfigurability is accomplished using frequency tuning. Also, the principle of reconfigurability in meander antenna focuses size reduction and dual band operations. The meander structure is characterized for its operating frequency. A parametric study is done for finding the resonance in the appropriate arm positions of the meander antenna. The varactor diodes fixed meander antenna is tested using network analyzer. The comparison is made for the antenna designs of with and without varactor diodes for the establishment of reconfigurability. The effects of active components are ignored. The proposed antenna design is validated for its concurrence in both simulation and experimentation. The arm and the behavior of the frequency tuning is tested using the network analyzer. The reflection coefficient is -23.66dB and -18.41dB at 2.45 GHz and 5.1 GHz respectively. The overall size of the meander antenna is reduced by 76%. VSWR of the proposed antenna is 1.

Bioactive steroids from seed germination supporting fungus (Ceratobasidium GS2) of the terrestrial orchid Gymnadenia conopsea

ABSTRACT Almost all orchids rely on mycorrhizal fungus to support their seed germination. To date, the effect of active components in mycorrhizal fungus on orchid seed germination largely remains unknown. In this study, we aimed to investigate the impact of active components found in mycorrhizal fungus on orchid seed germination. Specifically, we focused on a terrestrial orchid Gymnadenia conopsea and its host-specific seed germination supporting fungus Ceratobasidium GS2. In total, several steroids (1–7) were isolated from this fungus. Notably, compounds 1, 2, 4, and 5 exhibited significant enhancements in protocorm volume. Moreover, compounds 1–6 demonstrated strong promotion of protocorm differentiation. These findings suggest that steroids may play a crucial role in the symbiotic germination of G. conopsea seeds. Future studies should continue to explore the specific mechanisms through which these steroids exert their effects, contributing to our understanding of orchid biology and mycorrhizal interaction.

Anti-cervical cancer activity of Portulaca oleracea L. and the mechanism of synergistic cisplatin

• Flavonoids was core components of PO for anti-cevical cancer. • POF combined with cisplatin showed stronger anti-cevical cancer effect. • POF and cisplatin shared common targets related to apoptosis in cervical cancer. • The mechanism was related to inducing apoptosis through PI3K/Akt signaling pathway. To explore the antitumor active components and its underlying synergistic mechanism of Portulaca oleracea L. (PO), an edible plant and traditional medicine on cervical cancer based on network pharmacology and experimental validation. Effects of active components (POF) alone or in combination with cisplatin against cervical cancer were evaluated by detecting cell viability, cell cycle, and activities associated with apoptosis, such as reactive oxygen species, mitochondrial membrane potential and PI3K/Akt signaling pathway. The results showed that POF combined with cisplatin showed stronger anti-tumor effect. Ten main active components were screened and flavonoids was core components. POF and cisplatin shared common targets related to apoptosis in cervical cancer. The mechanisms were associated with inducing apoptosis through PI3K/Akt signaling pathway. The study revealed the active ingredients and potential targets and mechanism of POF combined with cisplatin against cervical cancer. PO may become a potential complementary and alternative drug for cervical cancer.

Dehydrogenation of Cycloalkanes over N-Doped Carbon-Supported Catalysts: The Effects of Active Component and Molecular Structure of the Substrate.

Efficient dehydrogenation of cycloalkanes under mild conditions is the key to large-scale application of cycloalkanes as a hydrogen storage medium. In this paper, a series of active metals loaded on nitrogen-doped carbon (M/CN, M = Pt, Pd, Ir, Rh, Au, Ru, Ag, Ni, Cu) were prepared to learn the role of active metals in cycloalkane dehydrogenation with cyclohexane as the model reactant. Only Pt/CN, Pd/CN, Rh/CN and Ir/CN can catalyze the dehydrogenation of cyclohexane under the set conditions. Among them, Pt/CN exhibited the best catalytic activity with the TOF value of 269.32 h−1 at 180 °C, followed by Pd/CN, Rh/CN and Ir/CN successively. More importantly, the difference of catalytic activity between these active metals diminishes with the increase in temperature. This implies that there is a thermodynamic effect of cyclohexane dehydrogenation with the synthetic catalysts, which was evidenced by the study on the activation energy. In addition, the effects of molecular structure on cycloalkane dehydrogenation catalyzed by Pt/CN were studied. The results reveal that cycloalkane dehydrogenation activity and hydrogen production rate can be enhanced by optimizing the type, quantity and position of alkyl substituents on cyclohexane.

Mesoscopic rheological modeling of drilling fluids: Effects of the electrolyte

Drilling fluid is a complex fluid, including base fluid and other materials, carrying out the vital functions during drilling operation such as cutting transport and controlling formation pressure. In order to optimize performance of a drilling process, a reliable rheological model is required in the computation of fluid flow dynamics. Time-independent Generalized Newtonian formulation are the most common models for describing the rheological behavior of drilling fluids due to its simplicity and ease of use, in spite the fact that they are not able to predict the normal stresses and could not consider effects of active components on the rheological behavior of the drilling fluid and also could not describe the internal microstructures changes in the fluid during its flow. In this paper, a rather simple model in the mesoscopic level of study through the Generalized Bracket formalism have been developed to consider the influence of salts and electrolytes on the rheology of drilling fluid which has received less attention in the previous models. The advantage of this model is that it provides a description for the structural and orientation changes during transient and steady state fluid flows beside prediction of the transient and steady rheological behavior of salt containing suspensions of bentonite in polymeric solutions. Comparison of the model predictions with the published data from literature shows that the model predictions for the effects of the drilling fluid components including clay and salts are in well agreement with those of the rheological experimental data.

The Hypolipidemic Effect of Active Components in the Decoction of Alisma Orientale and their Chemical Structures Characterized by LC-QTOF-MS/MS

Background: The decoction of Alisma orientale is used as a traditional medicine for the treatment of hyperlipidemia in China with a long clinical history. The present study undertook a detailed investigation to compare the hypolipidemic effect and chemical composition of two extracts of Alisma orientale prepared by boiling water and organic reagent, respectively. Methods: The hyperlipidemic mice were induced by administration of a High-Fat Diet (HFD) for one month. The body weight of mice and the serum Cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), Superoxide Dismutase (SOD), malondialdehyde (MDA), aspartate Aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined. Meanwhile, the chemical constituents of the extracts were characterized using liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOF-MS/MS). Results: The better hypolipidemic effect was observed in mice administered with the decoction compared to that of methanol extract. In addition, the liver protective effects were confirmed by the photographs stained with oil red lipid stain. As for the chemical constituents in the extracts, twenty major components were identified or characterized using LC-QTOF-MS/MS. Among them, eight oligopeptides were characterized for the first time and proved to only exist in the decoction of Alisma orientale. Conclusion: It is reasonable to assume that the oligopeptides may partially contribute to the hypolipidemic effect of Alisma orientale. The structural characterization procedures also provide a suitable method to analyze oligopeptide analogues in plant samples.

Effect of active components on strength development in alkali-activated low calcium fly ash cements

The compressive strength achieved in alkali-activated low-calcium fly ash depends on the total reactive oxide ratios in the activated system, the reactive alumina content in fly ash and the initial molarity of NaOH. The total reactive silica in the system is the reactive silica contributed by the fly ash and soluble silica from the alkaline solution. A minimum molarity of NaOH is required to ensure complete dissolution of the glassy phase present in fly ash. The maximum compressive strength depends on the amorphous reaction product content formed, which is determined by the reactive alumina content in the fly ash. The highest compressive strength is achieved for the ratio of the total reactive silica to sodium ratio in the activated system equal to 4.72 and lower. More Na is incorporated in the reaction product on increasing the Na2O content relative to the reactive oxides.

In vivo fungicidal properties of Diospyros kaki-isolated compound and its analogues

Fungicidal effects of active component purified from Diospyros kaki roots and its analogues against Erysiphe graminis, Botrytis cinerea, Pyricularia grisea, Puccinia recondite, Rhizoctonia solani, and Phytophthora infestans were investigated using a whole-plant method. Active constituents isolated from the chloroform fraction of D. kaki roots were characterized as plumbagin, using various spectroscopic analyses. To establish the structure–activity relationships, the fungicidal effects of plumbagin and its structural analogues were bioassayed against phytopathogenic fungi. At 0.25, 0.125, and 0.0625 g/L, plumbagin had a greater fungicidal effect than p-naphthoquinone, juglone, lawsone, 2-methoxy-p-naphthoquinone, or menadione against P. grisea, B. cinerea, R. solani, and E. graminis. Our results suggest that the methyl and hydroxyl functional groups at the 5′- and 2′-positions of p-naphthoquinone play key roles in its fungicidal effect against six phytopathogenic fungi. Therefore, plumbagin and its analogues may be suitable as antifungal agents to control plant diseases.

The effect of active components from citrus fruits on dentin MMPs

ObjectivesThis study was aimed to evaluate the anti-matrix metalloproteinases (MMPs) ability of active components from citrus fruits (hesperetin: Hst, hesperidin: Hsd and naringenin: Nge). MethodsInactivation effects of citrus flavonoids (Hst, Hsd, Nge) at different concentrations on soluble collagenase were measured using a fluorometric assay. Matrix-bound endogenous MMPs activity was evaluated via dry mass loss and hydroxyproline (HYP) release of demineralized human dentin. Demineralized dentin beams were pretreated with 500μg/mL citrus flavonoids for 10min. Chlorhexidine (CHX) was used as inhibitor control. Beams pretreated with distilled water served as blank control. Dentin slabs were used for in situ zymography and evaluated under confocal microscopy. Ultrastructure of demineralized collagen fibers was exhibited by Transmission Electron Microscopy (TEM). ResultsCitrus flavonoids exhibited inactivation function on soluble MMPs and the extent of inactivation increased in a dose-dependent manner. The inactivation percent of citrus flavonoids reached above 90% at the concentration of 500μg/mL. Compared with control group, citrus flavonoids pretreated demineralized dentin beams exhibited less dry mass loss, lower hydroxyproline release and more intact collagen architecture after 15days storage. Dentin samples pretreated with citrus flavonoids showed lower enzymes activities in in situ zymography. ConclusionsHst, Hsd or Nge have anti-MMPs ability and can preserve dentin collagen from degradation.Clinical Significance: Hst, Hsd and Nge may have the potential to be used in dentin bonding systems and improve the resin-dentin bonding durability.

Screening anti-allergic components of Astragali Radix using LAD2 cell membrane chromatography coupled online with UHPLC-ESI-MS/MS method.

Huangqi (Astragali Radix), a traditional Chinese herb, is widely used in clinical therapy in China. In addition, an anti-allergic effect of constituents in Huangqi has been reported in the scientific literature. In the present study, cell membrane chromatography coupled online with UHPLC-ESI-MS/MS method was developed to screen, analyze and identify the anti-allergic components of Huangqi. The Laboratory of Allergic Disease 2 (LAD2) cell was used to establish cell membrane chromatography, which was combined with UHPLC-ESI-MS/MS. The coupled system was then used to screen anti-allergic components from Huangqi. Effects of active components were verified by histamine release assay. A component retained on the LAD2 cell membrane chromatography was identified as formononetin. Bioactivity of formononetin was investigated by histamine release assay in LAD2 cells, and it was found that formononetin could inhibit histamine release in a dose-dependent manner from 1 to 100 μm. The LAD2 cell membrane chromatography online with UHPLC-ESI-MS/MS method is an effective technique for screening the anti-allergic components of Huangqi.

Antiplatelet Effect of Active Components Derived from Chinese Herbal Medicine.

Atherothrombosis is the major cause of acute coronary syndromes and cardiovascular deaths. Platelets participate in the processes of forming and extending atherosclerotic plaques. Therefore, antiplatelet therapy is a milestone in the primary and second prevention of atherothrombotic diseases. Along with the longterm use of antiplatelet agents, the safety and drug resistance has become a big concern in clinic and new drugs possessing higher effectiveness and fewer adverse effects are needed. Abundant recent data support that traditional Chinese herbs may be a good alternative and complementary choice of new antiplatelet drugs. This review highlights the progress of antiplatelet effect of active components derived from traditional Chinese herbs based on their chemical structures.

Comparison of protective effects of eight ethyl acetate extracts from Eclipta prostrate on NHBE cells based on component structure theory

To analyze and compare the protective effects of active components in different ethyl acetate extracts (EAEEPs) from Eclipta prostrate, in order to study the comparison of materials bases protecting normal human bronchial epithelial (NHBE) cells. The MTT assay was taken to compare the protective effect of different EAEEPs on cigarette smoke extracts (CSE) -induced NHBE cells. The ultra-performance liquid chromatography (UPLC) was applied to analyze the content of phenolic acid, coumaric grass ether and flavonoid in EAEEPs. According to the results, all of the eight EAEEPs (0-200 mg x L(-1)) showed certain protective effect on NHBE cells, with statistical difference. Specifically, the total mass of EAEEP VII (89.15 mg x L(-1)) and EAEEP VIII (57.44 mg x L(-1)), which showed the strongest activity, was not the highest, while EAEEP III (132.25 mg x L(-1)) displayed the highest total mass. In the combination with the "component structure" theory, the analysis showed a significant difference in the mass structure among phenolic acid, coumaric grass ether and flavonoid in EAEEP VIII and EAEEP VIII, which were 1.0: 1. 0: 0.5 and 1.0: 1.9: 0.8, respectively. The results suggested a specific optimal "component structure" relationship may exist in EAEEP, which could provide reference for the material base study and quality control.

Desulfurization and Regeneration Performance of Sorbent Prepared by Subcritical Water Impregnation

A series of metal oxides sorbents supported on γ-Al2O3 were directly prepared by subcritical water impregnation (SCWI) method using an autoclave reactor. The effects of active components, preparation pressure, temperature, and time on the desulfurization activity of sorbents in hot coal-based gases at mid-temperature were investigated. The samples were characterized by X-ray diffraction (XRD), nitrogen adsorption and atomic absorption spectrophotometer (AAS). The results showed that Mn-based sorbent loaded on γ-Al2O3 by SCWI presented a good desulfurization performance. The optimal preparation parameters of sorbent were the temperature of 350 °C, the pressure of 18.9 MPa, impregnation time of 30 min, the precursor solution concentration of 0.287 mol/L and the volume of 100 ml, respectively. The Mn/γ-Al2O3 sorbent prepared under the optimal conditions presented a good desulfurization precision and regeneration performance. After regeneration, the mechanical strengths of the sorbents were higher than that of raw support and the breakthrough time at the desulfurization efficiency of above 99% was not obviously decreased.

Thinking and practice on research of effective components of traditional Chinese medicine compound prescriptions

By analyzing current research status and considering our own previous research results, we hold that research on active substance of Chinese herbal formula should be focused on the effect of active components according to its functions, thus determining the main effective components of traditional Chinese medicine (TCM) compound prescriptions. Study of compatibility of effective components should be carried out and compound prescriptions composed of effective components should be developed. It is a pivotal way to deepen research on active components of TCM compound prescription by further analyzing the compatibility of effective components and the relationship between functional components and active components by multilink and multitarget methods.

Ethylbenzene dehydrogenation in the presence of carbon dioxide over alumina supported catalysts

The dehydrogenation of ethylbenzene to styrene was performed in the presence of carbon dioxide instead of steam over a series of alumina supported catalysts, which was believed to be an energy-saving and environmentally friendly process. The effects of active components, promoters, textural properties and other preparation parameters on the catalyst behaviors were examined. The results indicated that the conversion of ethylbenzene could be greatly improved by the reaction coupling due to the simultaneous elimination of hydrogen produced from the dehydrogenation, and vanadium supported on alumina with chromium as promoter was suggested to be promising catalysts. With the catalyst VCr/Al 2O 3, high ethylbenzene conversion (about 50%) and selectivity to styrene (95–99%) at lower temperature (550 °C) was achieved with reasonable stability (>70 h). The main cause of catalyst deactivation is the coke deposition, which may be alleviated in the presence of carbon dioxide. The catalytic activity of V/Al 2O 3 can be resumed completely after burning the coke by air or diluted air. Moreover, the catalyst characterization showed that high ratio of mesopore in the γ-Al 2O 3 support could benefit the catalyst activity and stability.

Investigation on the catalysis of CO x-free hydrogen generation from ammonia

The effects of active component (Ru, Rh, Pt, Pd, Ni, Fe) and support (CNTs, AC, Al 2O 3, MgO, ZrO 2, TiO 2) on the catalysis of ammonia decomposition were studied for the generation of CO x -free hydrogen. It was shown that the Ru catalyst using CNTs as support exhibits the highest conversion of NH 3. The performance can be further improved by modifying CNTs with KOH. According to the results of XRD, TEM, and chemisorption (CO and H 2 as adsorbates) investigations, Ru dispersion is the highest on CNTs. In the range of 2–5 nm, the particle size of Ru on CNTs is the smallest among the supported Ru catalysts; the Ru particles on the metal oxides are in the 3–16 nm range. It seems that larger Ru particles are more active for NH 3 decomposition in terms of TOF. Further investigation on the relationship between support basicity and catalytic activity disclosed that a support material of strong basicity is essential for high catalytic performance. In the N 2-TPD studies of supported Ru catalysts, desorption was promoted over catalysts of strong basicity, suggesting that N 2 desorption is the rate-determining step in ammonia decomposition. These results implied that it is possible to develop a highly efficient Ru catalyst for NH 3 decomposition by using electron-conductive materials of strong basicity as support.

Structure characterization of the Co and Ni catalysts for carbon dioxide reforming of methane

The effects of active components, promoters and reforming reaction on structure variation of catalysts for carbon dioxide reforming with methane are extensively investigated. It is found that the active component and promoters disperse in different sites on the support. The impregnated metal species may be mainly located on the inner surface of the micropore of the support. The 8.5%Ni–2%MgO–3%CeO 2/Al 2O 3 catalyst achieves best metal dispersion among the tested catalysts. It is also interesting to note that the addition of the alkaline oxide promoter (MgO) prohibits the metal dispersion on the support, while the addition of rare-earth metal oxide CeO 2 effectively promotes the Ni metal dispersion on the surface of the support despite of unsatisfactory self-dispersion of CeO 2 promoter.

Ｃｏｍｐｏｕｎｄ４８／８０の活性オリゴマーによる肥満細胞からのヒスタミン分泌機構とりん脂質代謝について

We synthesized compound 48/80, and fractionated by TLC into 14 components with various histamine-releasing activities and different Ca2+-requirements for their actions. The effect of active component was investigated on phospholipid metabolism during the postreceptorligand-binding in relation to the Ca2+-dependent histamine release from mast cells. The most active component (MW=2280, a tridecamer of N-methyl-p-methoxyphenylethylamine monomer) induced the Ca2+-dependent histamine release from mast cells, via its binding to a specific sites on the membranes. The binding reaction, a Ca2+ -independent process, induced the Ca2+-independent changes of polyphosphoinositol cv le including the hydrolysis of PIP2 and IP3 formation. On the other hand, it stimulated Ca2+-dependent releases of arachidonic acid, prostaglandins and HETEs. Kinetic analysis suggests that the binding of ligand to receptor induced a rapid accumlation of arachidonic acid into PA, PI and PC, with concomitant decrease of the arachiodonic acid from PE, following a Ca2+-dependent increase of phospholipase A2, prior to the detectable histamine release.