884 research outputs found
Myrica esculenta Buch.-Ham. ex D. Don: A natural source for health promotion and disease preventdion
Myrica esculenta (Myricaceae) is a popular medicinal plant most commonly found in the sub-tropical Himalayas. It is widely used in folk medicine to treat several ailments such as asthma, cough, chronic bronchitis, ulcers, inflammation, anemia, fever, diarrhea, and ear, nose, and throat disorders. Due to its multidimensional pharmacological and therapeutic effects, it is well recognized in the ayurvedic pharmacopeia. However, the recent upsurge in M. esculenta use and demand has led to illicit harvesting by the horticultural trade and habitat loss, pushing the plant to the brink of extinction. Thus, the present review aims to provide updated information on M. esculenta botany, ethnomedicinal uses, phytochemistry, pharmacological effects, toxicity, and conservation methods, as well as also highlight prospective for future research. Particular emphasis is also given to its antioxidant potential in health promotion. In-depth literature was probed by searching several sources via online databases, texts, websites, and thesis. About 57 compounds were isolated and identified from M. esculenta, and the available reports on physicochemical parameters, nutritional and high-performance thin-layer chromatography analysis of bioactive plant parts are portrayed in a comparative manner. Friendly holistic conservation approaches offered by plant biotechnology applications, such as micropropagation, germplasm preservation, synthetic seed production, and hairy root technologies are also discussed. Nonetheless, further studies are needed to propose the mechanistic role of crude extracts and other bioactives, and even to explore the structureāfunction relationship of active components.Authors are thankful to A.P. Singh, Dean RIC, I. K. Gujral Punjab Technical University and members of sta_ in the department of RIC, I. K. Gujral Punjab Technical University for support and encouragement in this work. N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and āNORTE2020 - Northern Regional Operational Programā (NORTE-01-0145-FEDER-000012)
Phytochemical composition, antioxidant, and antimicrobial attributes of different solvent extracts from myrica esculenta buch.-ham. ex. d. don leaves
Background: Plant diversity is a basic source of food and medicine for local Himalayan communities. The current study was designed to assess the effect of different solvents (methanol, ethyl acetate, and water) on the phenolic profile, and the corresponding biological activity was studied. Methods: Antioxidant activity was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2Āæ-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) assay, while the antimicrobial activity was evaluated by disk diffusion method using various bacterial and fungal strains. Results: The outcomes demonstrated that methanol acted as the most effective solvent for polyphenols extraction, as strengthened by the liquid chromatography and mass spectroscopy (LC-MS) and fourier transform infrared spectroscopy (FTIR) analysis. M. esculenta methanol extract showed the highest DPPH and ABTS radical scavenger antioxidant activity with IC50 values of 39.29 Āµg/mL and 52.83 Āµg/mL, respectively, while the ethyl acetate and aqueous extracts revealed minimum antioxidant potential. Methanol extract also revealed higher phenolic content, 88.94 Ā± 0.24 mg of equivalent gallic acid (GAE)/g), measured by the FolināCiocalteu method, while the minimum content was recorded for aqueous extract (62.38 Ā± 0.14 GAE/g). The highest flavonoid content was observed for methanol extract, 67.44 Ā± 0.14 mg quercetin equivalent (QE)/g) measured by an aluminum chloride colorimetric method, while the lowest content was recorded for aqueous extract (35.77 Ā± 0.14 QE/g). Antimicrobial activity findings also reveal that the methanol extract led to a higher inhibition zone against bacterial and fungal strains. FTIR analysis reveals the presence of various functional groups, viz. alkenes, amines, carboxylic acids, amides, esters, alcohols, phenols, ketones, carboxylic acids, and aromatic compounds. This FTIR analysis could serve as a basis for the authentication of M. esculenta extracts for future industrial applications. Compounds identified by LC-MS analysis were gallic acid, myricanol, myricanone, epigallocatechin 3-O-gallate, Ć-sitosterol, quercetin, p-coumaric acid, palmitic acid, n-pentadecanol, n-octadecanol, stigmasterol, oleanolic acid, n-hexadecanol, cis-Ć-caryophyllene, lupeol, and myresculoside. Conclusion: This study suggests that the methanolic extract from M. esculenta leaves has strong antioxidant potential and could be a significant source of natural antioxidants and antimicrobials for functional foods formulation.Authors are thankful to A.P. Singh, Dean RIC, I.K. Gujral Punjab Technical University and members of staff in the department of RIC, I.K. Gujral Punjab Technical University for support and encouragement in this work. N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and āNORTE2020āNorthern Regional Operational Programā (NORTE-01-0145-FEDER-000012)
An efficient method for measuring dissolved VOSCs in wastewater using GC-SCD with static headspace technique
Volatile organic sulfur compounds (VOSCs) are important sources of unpleasant odor in wastewater systems. However, the study of VOSCs is usually hindered by their complicated measurement method and highly reactive nature. In this work, a static headspace method utilising gas chromatography (GC) with a sulfur chemiluminescence detector (SCD) was developed to quantitatively analyze VOSCs in wastewater matrices. The method has low detection limits and requires no pre-concentration treatment. Three typical VOSCs, namely methanethiol (MT), dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), were chosen as examples for this study. The calibration curves of all three compounds covering a wide range from 0.5 ppb to 500 ppb showed good linearity (R-2 > 0.999). The method detection limits (MDL) were 0.08, 0.12 and 0.21 ppb for MT, DMS and DMDS, respectively. The reproducibility (relative standard deviation) was approximately 2%. The recovery ratio of MT, DMS and DMDS in spiked wastewater samples were 83 +/- 4%, 103 +/- 4% and 102 +/- 3%, respectively. Sample preservation tests showed that VOSCs in wastewater samples could be preserved in vials without headspace under acidified conditions (pH similar to 1.1) for at least 24 h without significant changes
Molecular motors robustly drive active gels to a critically connected state
Living systems often exhibit internal driving: active, molecular processes
drive nonequilibrium phenomena such as metabolism or migration. Active gels
constitute a fascinating class of internally driven matter, where molecular
motors exert localized stresses inside polymer networks. There is evidence that
network crosslinking is required to allow motors to induce macroscopic
contraction. Yet a quantitative understanding of how network connectivity
enables contraction is lacking. Here we show experimentally that myosin motors
contract crosslinked actin polymer networks to clusters with a scale-free size
distribution. This critical behavior occurs over an unexpectedly broad range of
crosslink concentrations. To understand this robustness, we develop a
quantitative model of contractile networks that takes into account network
restructuring: motors reduce connectivity by forcing crosslinks to unbind.
Paradoxically, to coordinate global contractions, motor activity should be low.
Otherwise, motors drive initially well-connected networks to a critical state
where ruptures form across the entire network.Comment: Main text: 21 pages, 5 figures. Supplementary Information: 13 pages,
8 figure
Changes in the Hearing Thresholds of Infants Who Failed the Newborn Hearing Screening Test and in Infants Treated in the Neonatal Intensive Care Unit
ObjectivesThe aim of this study was to investigate changes in the hearing thresholds during the first year of life in infants who failed the newborn hearing screening (NHS) test and of infants treated in the neonatal intensive care unit (NICU).MethodsFrom March 2007 to November 2010, 193 healthy infants who failed the NHS test and 51 infants who were treated in the NICU were referred for evaluation of hearing acuity. Their hearing was evaluated using impedance audiometry, auditory brainstem response (ABR), and otoacoustic emission before 6 months of age, and follow-up hearing tests were administered before 12 months of age. Changes in their hearing thresholds were then analyzed.ResultsOf the 193 healthy infants who failed the NHS test, 60 infants (31%) had normal hearing acuity, 126 infants (65%) had sensorineural hearing loss (SNHL, ABR threshold ā„40 dB) and 7 infants (4%) had auditory neuropathy (AN). On the follow-up hearing tests, which were conducted in 65 infants, 6 infants showed a hearing threshold deterioration of more than 20 dB, and 19 infants showed a hearing threshold improvement of more than 20 dB. Of the 51 infants who were treated in the NICU, 38 infants (75%) had normal hearing acuity, 12 infants (24%) had SNHL, and one infant (2%) had AN. In the follow-up hearing tests, which were performed in 13 infants, one infant with normal hearing progressed to severe hearing loss. Five infants who had SNHL showed a hearing threshold improvement of more than 20 dB, and 4 infants recovered to normal hearing.ConclusionThe hearing thresholds of infants with congenital SNHL can change during the first year of life; therefore, the importance of administration of follow-up hearing tests is emphasized. Irreversible intervention such as cochlear implantation should be considered with great caution within the first year after birth
Exploring the opportunities for carbon capture in modular, small-scale steam methane reforming: an energetic perspective
Source contribution to the bulk atmospheric deposition of minor and trace elements in a Northern Spanish coastal urban area
Mo, Ni, Pb, Ti, V and Zn was investigated in Santander, a Northern Spanish coastal city. Bulk deposition samples were collected monthly for three years using a bottle/funnel device. Taking into account that heavy metals are bioavailable only in their soluble forms, water-soluble and water-insoluble fractions were evaluated separately for element concentration. The fluxes of the studied elements in the bulk deposition exhibited the following order: Zn>Mn>>Cu>Cr>Pb>V>Ni>>As>Mo>Cd. The fluxes of Zn and Mn were more than 10 times higher than those of the other elements, withmaximumvalues of 554.5 and 334.1 Āµg m-2 day-1, respectively. Low solubilities (below 22%) were found for Cr, Ti and Pb, whereas the highest solubility was found for Zn (78%). With the exception of Cu, all of the studied metals in the water-soluble fraction of the atmospheric deposition showed seasonal dependence, due to the seasonal variability of precipitation. The enrichment factors (EFs) of Cu, Cd and Zn were higher than 100, indicating a clear anthropogenic origin. The EF of Mn (50) was below 100, but an exclusively industrial origin is suggested. Positive Matrix Factorisation (PMF) was used for the source apportionment of the studiedminor and trace elements in the soluble fraction. Four factors were identified from PMF, and their chemical profiles were compared with those calculated from known sources that were previously identified in Santander Bay: two industrial sources, the first of which was characterised by Zn and Mn, which contributes 62.5% of the total deposition flux of the studied elements; a traffic source; and a maritime source. Zinc and Mn are considered to be the most characteristic pollutants of the studied area.The authors are grateful for the financial support from the CTM 2010-16068 project (Spanish Ministry of Science and Innovation)
Gene Expression Profiling on Global cDNA Arrays Gives Hints Concerning Potential Signal Transduction Pathways Involved in Cardiac Fibrosis of Renal Failure
Cardiac remodelling with interstitial fibrosis in renal failure, which so far is only poorly understood on the molecular level, was investigated in the rat model by a global
gene expression profiling analysis. SpragueāDawley rats were subjected to subtotal
nephrectomy (SNX) or sham operation (sham) and followed for 2 and 12 weeks,
respectively. Heart-specific gene expression profiling, with RZPD Rat Unigene-1
cDNA arrays containing about 27 000 gene and EST sequences revealed substantial
changes in gene expression in SNX compared to sham animals. Motor protein genes,
growth and differentiation markers, and extracellular matrix genes were upregulated
in SNX rats. Obviously, not only genes involved in cardiomyocyte hypertrophy, but
also genes involved in the expansion of non-vascular interstitial tissue are activated
very early in animals with renal failure. Together with earlier findings in the SNX
model, the present data suggest the hypothesis that the local renināangiotensin system
(RAS) may be activated by at least two pathways: (a) via second messengers and Gproteins
(short-term signalling); and (b) via motor proteins, actins and integrins (longterm
signalling). The study documents that complex hybridization analysis yields
reproducible and promising results of patterns of gene activation pointing to signalling
pathways involved in cardiac remodelling in renal failure. The complete array data
are available via http://www.rzpd.de/cgi-bin/services/exp/viewExpressionData.pl.cg
Comparing national home-keeping and the regulation of translational stem cell applications: an international perspective
A very large grey area exists between translational stem cell research and applications that comply with the ideals of randomised control trials and good laboratory and clinical practice and what is often referred to as snake-oil trade. We identify a discrepancy between international research and ethics regulation and the ways in which regulatory instruments in the stem cell field are developed in practice. We examine this discrepancy using the notion of ānational home-keepingā, referring to the way governments articulate international standards and regulation with conflicting demands on local players at home.
Identifying particular dimensions of regulatory tools ā authority, permissions, space and acceleration ā as crucial to national home-keeping in Asia, Europe and the USA, we show how local regulation works to enable development of the field, notwithstanding international (i.e. principally āwesternā) regulation. Triangulating regulation with empirical data and archival research between 2012 and 2015 has helped us to shed light on how countries and organisations adapt and resist internationally dominant regulation through the manipulation of regulatory tools (contingent upon country size, the state's ability to accumulate resources, healthcare demands, established traditions of scientific governance, and economic and scientific ambitions)
Antixenosis and antibiosis mechanisms of resistance to pod borer, Helicoverpa armigera in wild relatives of chickpea, Cicer arietinum
The noctuid pod borer, Helicoverpa armigera is one of the most damaging pests of chickpea, Cicer arietinum. The levels of resistance to H. armigera in the cultivated chickpea are low to moderate, but the wild relatives of chickpea have exhibited high levels of resistance to this pest. To develop insect-resistant cultivars with durable resistance, it is important to understand the contribution of different components of resistance, and therefore, we studied antixenosis and antibiosis mechanisms of resistance to H. armigera in a diverse array of wild relatives of chickpea. The genotypes IG 70012, PI 599046, IG 70022, PI 599066, IG 70006, IG 70018 (C. bijugum), ICC 506EB, ICCL 86111 (cultivated chickpea), IG 72933, IG 72953 (C. reticulatum), IG 69979 (C. cuneatum) and IG 599076 (C. chrossanicum) exhibited non preference for oviposition by the females of H. armigera under multi-choice, dual-choice and no-choice cage conditions. Based on detached leaf assay, the genotypes IG 70012, IG 70022, IG 70018, IG 70006, PI 599046, PI 599066 (C. bijugum), IG 69979 (C. cuneatum), PI 568217, PI 599077 (C. judaicum) and ICCW 17148 (C. microphyllum) suffered significantly lower leaf damage, and lower larval weights indicating high levels of antibiosis than on the cultivated chickpea. Glandular and non-glandular trichomes showed negative correlation with oviposition, while the glandular trichomes showed a significant and negative correlation with leaf damage rating. Density of non-glandular trichomes was negatively correlated with larval survival. High performance liquid chromatography (HPLC) fingerprints of leaf surface exudates showed a negative correlation of oxalic acid with oviposition, but positive correlation with malic acid. Both oxalic acid and malic acid showed a significant negative correlation with larval survival. The wild relatives exhibiting low preference for oviposition and high levels of antibiosis can be used as sources of resistance to increase the levels and diversify the basis of resistance to H. armigera in cultivated chickpea
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