Comparative light and scanning electron microscopy in authentication of adulterated traded medicinal plants

The medicinal plants are utilized globally considering the cheap and chemical free source, but their correct identification and authentication is prerequisite for safety and efficacy of plant‐based medicines. The present study encompassed traded medicinal plants (16) with high therapeutic value from diverse families like Brassicaceae, Berberidaceae, Malvaceae, Salicaceae, Myrtaceae, Papilionaceae, Ascelpiadaceae, Colchicaceae, Violaceae, and Vitaceae for detailed microscopic study of characters that is, morphology, pollen shape and sizes, P/E ratio, pore length and width, spine length, colpi dimensions, and exine sculpture pattern. The plants showed noteworthy differences in microscopy of Wattakaka volubilis having pollinia, translator and corpusculum like structures while pores were visible in Colchicum luteum, Alcea rosea, and Hibiscus syriacus. The spines were observed in Centipeda minima, A. rosea, and H. syriacus being dimorphic spines in A. rosea and monomorphic in H. syriacus. The exine sculpturing pattern was reticulate in mostly studied plants however distinctive exine pattern was noted in Berberis aristata and Berberis lyceum. The highest polar diameter, equatorial diameter and exine thickness among studied plants were observed in H. syriacus (161 μm), C. luteum (50 μm) and Vitis jacquemontii (1.10), respectively. Thus, microscopy of medicinal plants in addition to other taxonomic evidence offers a supportive skill in authentication, consequently utilization by local consumers and pharmaceutical industries.     

Palyno‐morphological investigations of subtropical endangered flora of Capparidaceae through light and scanning electron microscopy

The research was performed to investigate pollen morphology of endangered species of Capparidaceae in subtropical regions of Pakistan. The distinguishing characters were investigated by using light microscope and scanning electron microscope. Palynological study is comprised of pollen shape, pollen type, exine sculpturing, polar and equatorial diameter, length and width of colpi, mesocolpium, and exine thickness. In polar view, Cleome viscosa exhibited the highest pollen size 26.4 (32.7–24.5 μm) ±0.776 whereas Capparis spinosa appeared to be the lowest 12.6 (14.5?10.7 μm) ±0.400. In equatorial view, Cleome viscosa had the largest pollen size 17.1 (20.0–15.0 μm) ±0.606 and Capparis spinosa had the smallest pollen size 9.7 (12.50–8.00 μm) ±0.394. The maximum fertility percentage has been observed in Capparis spinosa, that is, 98.96% and minimum in Cleome viscosa, that is, 82.93%. Diagnostic key has been constructed to state the essential diagnostic features by means of which the taxa can be identified. Remarkable variations have been observed in pollen size, shape, and exine sculpturing. All the selected species were tricolporate. Prolate to subprolate pollen were observed. There is a great variation existed in exine sculpturing such as in Capparis decidua and C. sp. nova sculpturing is reticulate, in Capparis himalayensis sculpturing is Scabrate granulate, in Capparis spinosa sculpturing is Psilate, in Cleome viscosa sculpturing is regulate‐reticulate, in Dipterygium glaucum sculpturing is regulate and in Gynandropsis gynandra sculpturing is striate‐regulate. On the basis of overall characteristics of pollen it seems that palynology of this family is helpful at the generic and specific level.     

Foliar epidermal anatomy of some selected wild edible fruits of Pakistan using light microscopy and scanning electron microscopy

The present study is focused on the detailed foliar epidermal anatomy of some selected wild edible fruits (WEFs) from Pakistan using light microscopy (LM) and scanning electron microscopy (SEM). The studied species are Ficus racemosa L., Solanum nigrum L., Capparis spinosa L., Physalis divaricata D.Don, Rosa moschata Herrm. and Ribes orientale Desf. collected from various localities of Pakistan. The objective of the present study is to investigate qualitative and quantitative anatomical characters for the identification and differentiation of collected wild edible fruits. The characters studied are shape and size of epidermal cells, anticlinal wall pattern, trichome type and shape, average number of stomata, length and width of stomata and pore. The detailed microscopic investigation and variations in the characters recorded have a key role in the determination and authentication of wild edible fruits. This study possesses great potential for plant taxonomists to further evaluate the species at molecular and genetic levels.     

Quality assurance and authentication of herbal drug (Argyrolobium roseum and Viola stocksii) through comparative light and scanning electron microscopy

The quality assurance and authentication of crude herbal drugs play important role in the effective therapeutic effect of herbal drug and their products. There are many reported problems in quality assurance of herbal crude drugs concerning to their correct identification. The present study was designed with the aim to document the authentication and quality assurance of the herbal crude drugs (Argyrolobium roseum and Viola stocksii) thorough light microscopy (LM) and scanning electron microscopy (SEM). The detailed foliar anatomical studies showed polygonal epidermal cells having anticlinal walls in Argyrolobium roseum while rounded epidermal cells were observed in Viola stocksii. The anomocytic stomata type was observed in Argrolobium roseum while actinocytic was noticed in Viola stocksii. The pollen of studied species appeared as tricolporate showing reticulate exine sculpturing in Argrolobium roseum while fine perforations were recorded in Viola stocksii. Furthermore, quantitative analysis of phenols, flavonoids, and antioxidant activity showed high flavonoid and phenol content in Argyrolobium roseum as compared with Viola stocksii. It was observed that Argyrolobium roseum was discriminated from the Viola stocksii based on the leaf and pollen micromorphological traits by using LM and SEM techniques. It was concluded that LM and SEM techniques were found useful for the quality assurance of botanicals and their authentication.     

Systematic significance of pollen morphology and foliar epidermal anatomy of medicinal plants using SEM and LM techniques

Alternative medicinal source is a hot issue within medicine community now a days due to various side effects of allotropic drugs; most importantly the multidrug resistance phenomena. Medicinal plants provide an attractive and effective alternative to modern synthetic drugs as they contain different types of bioactive compounds, having great potential in treatment of various diseases. The present study deals with identification of micromorphological characteristics of 10 ethnomedicinally important plants of Northern Pakistan, that is, Aster himalaicus C. B. Clarke, Artemisia maritima (Berg.) Wellkomm, Isodon rugosus (Wall. ex Benth.), Myricaria squamosal Desv, Pedicularis groenlandica Retz. Polygonum aviculare L, Salvia himmelbauer E. Peter, Swertia kingie Hook. f., Tanacetum dolichophyllum (Kitam) Kitam, Verbascum epixanthinum Boiss. & Heldr. as potential source for pharmaceutical industry. The characters studied were shape and size of pollen, polar diameter and equatorial diameter, epidermal cell shape and size, stomata width and length, trichome shapes, and type. Most of the species had tricolporate pollen type but hexacolporate pollen was also observed in Isodon rugosus, Polygonum aviculare, Salvia himmelbauer. Different types of exine sculpturing observed were foveolate, scabrate, lophate, regular, steriate, and alveolate. Minimum equatorial diameter was noted in Tanacetum dolichophyllum (12.4 μm) and maximum in Myricaria squamosal (20.9 μm). Shape of epidermis cell ranged from rectangular and irregular, polygonal and pentagonal. Different types of stomata like anisocytic, actinocytic, paracytic, and diacytic were noticed. Variations in microscopic characters observed in the current study have great potential to be used as identification tools by the taxonomists for further studies.     

Aliovalent Ho3+ ion doped BaZrO3 thin films; Structural,optical and photoluminescence properties

Ho doped BaZrO3 thin film phosphors with varying Ho content (1, 2, 3 and 4?at%) were prepared via pulsed laser deposition technique. To understand the effect of doping on structural, morphological, optical and emission properties of thin films, X-ray Diffractrometer (XRD), Scanning Electron Microscopy (SEM), Spectroscopic Ellipsometry (SE) and Photoluminescence (PL) Spectroscopy have been used, respectively. Polycrystalline nature with single phase cubic crystalline structure of the films has been obtained. The optical band gap energy, as estimated by SE, has been found to increase with increase in the Ho content. The PL spectra of the synthesized phosphor exhibit green and yellow-orange as prominent emission bands in response to 328?nm as excitation wavelength.     

Modelling and kinetic study of microwave assisted drying of ginger and onion with simultaneous extraction of bioactive compounds

Food Science and Biotechnology - Onion and ginger are rich sources of bioactive compounds which are lost during conventional drying process. The present study was designed to optimize the novel...     

An energy-efficient cuckoo search algorithm for virtual machine placement in cloud computing data centers

The Journal of Supercomputing - The advent of virtualization technology has created a huge potential application for cloud computing. In virtualization, a large hardware resource is often broken...     

Recent trends in environmentally friendly water-borne polyurethane coatings: A review

Environmentally friendly waterborne polyurethane (WPU) coatings are used extensively due to their low VOCs emission than solvent based PU coatings. Additionally, WPU coatings have low temperature flexibility, pH stability, water resistance, superior solvent resistance, outstanding weathering resistance and desirable chemical and mechanical properties. This review provides an overview on the recent developments of WPU coatings and their value added applications in the coatings and paint industry. UV-cured WPU coatings provide an important class of green and ecofriendly coatings with outstanding mechanical properties and rapid curing system. Hyper-branched polyurethanes (PUs) show interesting properties, such as high solubility, reactivity and good rheological behavior owing to multiple end groups, compact molecular structure and diminishing chain entanglement. Inherently, WPU coatings have reduced stiffness and mechanical strength that can be increased by the addition of nanoparticles, like Ag, Cu, TiO₂, SiO₂ and many more. Fire retardants, commonly phosphorous, are incorporated in the WPU structure to increase the flame retardancy of WPU coatings.     

Role of Ce-Mn substitution on structural, electrical and magnetic properties of W-type strontium hexaferrites

W-type hexaferrites with nominal composition Sr_1−xCe_xCo₂Mn_yFe_16−yO₂₇ (x = 0.00, 0.02, 0.04, 0.06 & y = 0.0, 0.2, 0.4, 0.6) has been synthesized by the chemical co-precipitation method. The effect of substitution of Ce at Sr & Mn at Fe site on the structural, magnetic and electrical properties has been investigated. The XRD patterns confirm single W-type hexaferrite phase and various parameters such as lattice constants (a & c), cell volume (V), crystallite size (D), X-ray density (d_x), bulk density (d_b) and porosity (P) were calculated from XRD data. The crystallite size is found in the range of 22.5-30 nm and this size is small enough to obtained suitable signal-to-noise ratio in high density recording media. The magnetic properties such as saturation magnetization, remanence, squareness ratio and coercivity were calculated from hysteresis loops and were observed to increase with increase in Ce-Mn concentration up to a certain substitution level. The resistivity showed interesting behavior with temperature, showing metal-to-semiconductor transition temperature. The increase in saturation and remanence suggest that the synthesized materials can be used in the high density recording media.