Panicle, spikelet, and floret development in orchardgrass (Dactylis glomerata)

1993 ◽  
Vol 71 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Joanna Fraser ◽  
Eric G. Kokko

The initial stages of panicle, spikelet, and floret development in field-grown 'Kay' orchardgrass were examined using scanning electron microscopy. Spikelets arose from a complex multilevelled sequence of initiation from branch apices. Spikelets developed indirectly in a two-tiered progression: (i) an acropetal and basipetal sequence of first order, second-order, and third-order inflorescence apices, and (ii) an acropetal development within subclusters of higher-order lateral branch inflorescence apices. The panicle had the unique feature of dorsiventrality as well as bilateral symmetry. The basal apex from first-order, second-order, or third-order apices developed on the same side of the main axis as the first-order apex. The two glumes subtending each spikelet primordium developed alternately and acropetally. Development and initiation of florets within spikelets was basipetal within the panicle, basipetal within clusters and subclusters of spikelets on lateral branches, and acropetal within spikelets. Within florets, paleas developed later than lemmas. Key words: Dactylis glomerata, cocksfoot, scanning electron microscopy, development, panicle.

2020 ◽  
Vol 10 (1) ◽  
pp. 63-75
Author(s):  
Antonio O. Costa ◽  
Claure N. Lunardi ◽  
Anderson J. Gomes

Purpose: This study assesses the kinetics of the anti-tumor drug chlorambucil (CLB) incorporated into PLGA nanoparticles (NP-CLB) with and without the presence of the O-stearoyl mannose (OEM) functionalizing agent (NP-CLBMAN). Methods: OEM was synthesized and used in the NP-CLB-MAN formulation. The nanoparticles were characterized by dynamic light scattering, electrophoretic light scattering, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Results: The nanoparticles presented an encapsulation efficiency greater than 61% and a PdI between 0.186–0.217. The mean size was 185 nm for NP-CLB and 220 nm for NPCLB- MAN, and the zeta potential values were -17.7 mV for NP-CLB and -14.2 mV for NP- CLB-MAN. Scanning electron microscopy showed that NPs with OEM have a surface with a different shape, and FTIR analyses showed binding of CLB to the drug delivery system, as well as functionalization with OEM. In vitro release studies showed a biphasic release profile for both systems, and they were analyzed considering the mathematical Korsmeyer-Peppas, first-order, and Fick diffusion models, and the combination of the first-order and Fick diffusion models. Conclusion: The experimental results obtained for the release of CLB were better described using a combination of the first order and Fick diffusion mathematical models.


2019 ◽  
Vol 3 (1) ◽  
pp. 34
Author(s):  
Yuni Kurniati ◽  
Okky Putri Prastuti ◽  
Eka Lutfi Septiani

Indonesia adalah negara berkembang dengan ribuan perusahaan di sektor industri yang menghasilkan limbah. Pisang adalah produk umum yang paling dikenal di masyarakat. Bagian pisang seperti kulitnya belum digunakan secara optimal namun dapat dikembangkan menjadi karbon aktif. Penelitian ini bertujuan memanfaatkan limbah kulit pisang sebagai adsorben untuk menghilangkan limbah pewarna metil biru pada industri tekstil. Pada umumnya limbah industri tekstil saat ini banyak mengandung pewarna. Adsorben yang digunakan untuk mengurangi kadar pewarna dalam limbah perlu dikembangkan. Kapasitas adsorpsi limbah kulit pisang dalam penelitian diamati, termasuk jumlah adsorben yang harus ditentukan dan konsentrasi limbah untuk menghilangkan pewarna tekstil. Sebelum digunakan sebagai adsorben, karbon aktif  limbah kulit pisang harus diaktivasi menggunakan 0,1 N dan 0,5 N larutan NaOH. Larutan metil biru dibuat dalam berbagai konsentrasi untuk menentukan kurva kalibrasi standar menggunakan spektrofotometer UV-Vis. Karakterisasi yang dilakukan dalam penelitian ini adalah Scanning Electron Microscopy (SEM) untuk mengetahui morfologi partikel karbon aktif. Hasilnya menunjukkan bahwa karbon aktif limbah kulit pisang akan menjadi alternatif untuk menghilangkan metil biru dengan proses adsorpsi dengan memiliki daya adsorbsi rata-rata sebesar 14,12 %.  Kinetika adsorpsi dari penelitian ini menggunakan model pseudo orde satu yaitu persamaan Lagergren dan pseudo-orde ke dua yang dikembangkan oleh Ho dan McKay yang menghasilkan konstanta adsorpsi k1 dari pseudo-ordesatu dalam larutan limbah tekstil dengan perbandingan konsentrasi antara limbah tekstil dengan aquades sebesar 3 : 7  (v/v) dengan aktivasi larutan 0,1 dan 0,5 N larutan NaOH adalah 0,0066 dan 0,0033 min-1 sedangkan untuk model hasil pseudo-orde ke dua k2 dengan aktivasi larutan 0,1 dan 0,5 N larutan NaOH adalah 1,8172 dan 1,2539 min-1.Indonesia is a developing country that has thousands of companies in the industrial sector that generally produce waste. Banana is the general product that mostly known in society. The other part of banana only as a waste product, such as banana peel that have not used optimally yet meanwhile it can be developed to be activated carbon. This research aims to use banana peels as an adsorbent for removing methylene blue.  In general, textile industry waste currently contains many dyes. Adsorbents used to reduce dye levels in waste need to be developed. The adsorption capacity of banana peel adsorption is observed, including the dose of adsorbent that must be applied and the concentration of waste for removal of textile dyes. Before being used as an adosorbent, the activated carbon of banana peel must be activated by using 0.1 N and 0.5 NaOH solution. Methyl blue solutions were made in various concentrations to determine standard calibration curves using a UV-Vis spectrophotometer. The characterization was used to support this study such as Scanning Electron Microscopy (SEM) analysis to find out the morphology of activated carbon particles. The result indicate that the banana peel activated carbon would be an alternative for the removal of methylene blue by adsorption process with  adsorption capacity as 14.12%. The adsorption kinetics of this study used model of pseudo-first order by Lagergren equation and pseudo-second order developed by Ho and Mc. Kay that result adsorption constant k1 of pseudo-first order in 3:7  (v/v) textile waste and aquadest by activation in 0.1 and 0.5 NaOH solution were 0.0066 dan 0,0033 min-1, while the model of pseudo-second order results k2 by activation in 0.1 and 0.5 NaOH solution were 1.8172 dan 1.2539 min-1.


2019 ◽  
Vol 26 (1) ◽  
pp. 47-55
Author(s):  
Birol Başer ◽  
Mehmet Firat ◽  
Riza Binzet

The pollen morphology of 10 Allium L. taxa, 6 of which are endemic to Turkey, were investigated in detail by light and scanning electron microscopy. According to LM and SEM, the pollen grains of genera were monad, monosulcate percolate, heteropolar with bilateral symmetry, 25.30 to 53,85 µm long axis (LA) and 17.55 to 36.86 µm short axis (SA), the form was prolate (mean of LA/SA ratio 1.30 to 1.70 and in polar view boat-shaped. Three types of ornamentation were determined. Striate-rugulate-perforate type in Allium longisepalum, A. oreophilum, A. anacoleum, A. microspathum, A.shirnakiense, A. purpureoviride and A. armenum, Rugulate–perforate type in A. pervariense and A. gabardagense and Rugulate–reticulate-perforate type in A. arlgirdense. Sulcus membrane ornamentations were rugulate or psilate. The sulcus extends from the distal to proximal ends in A. anacoleum, A. arlgirdense and A. pervariense. The present study on some Turkish species of Allium showed that several morphological pollen characters may possess taxonomical value.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.


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