Anisotropic Growth Control of Polyaniline Nanostructures and Their Morphology-Dependent Electrochemical Characteristics

ACS Nano ◽  
2012 ◽  
Vol 6 (9) ◽  
pp. 7624-7633 ◽  
Author(s):  
Hyun-Woo Park ◽  
Taejoon Kim ◽  
Jinyoung Huh ◽  
Minjeong Kang ◽  
Ji Eun Lee ◽  
...  
Keyword(s):  
Growth Control ◽  
Electrochemical Characteristics ◽  
Anisotropic Growth

scholarly journals Seedless gold nanostars with seed-like advantages for biosensing applications

2019 ◽  
Vol 6 (2) ◽  
pp. 181971 ◽  
Author(s):  
Masauso Moses Phiri ◽  
Danielle Wingrove Mulder ◽  
Barend Christiaan Vorster
Keyword(s):  
Growth Control ◽  
Building Blocks ◽  
Anisotropic Growth ◽  
Visible Spectroscopy ◽  
Naked Eye ◽  
Gold Nanostars ◽  
Plasmonic Sensing ◽  
Synthesis Strategy ◽  
Biomedical Diagnosis

Gold nanostars (AuNSs) are seen as promising building blocks for biosensors with potential for easy readouts based on naked-eye and ultraviolet–visible spectroscopy detection. We present a seedless synthesis strategy for AuNSs that has the advantages of the seeded methods. The method used ascorbic acid as a reducing agent and silver nitrate as an anisotropic growth control assisting agent. AuNSs with multiple branches and a diameter of 59 nm were produced. They showed good stability when capped with PVP and modified with an enzyme in relatively strong ionic conditions. We investigated their application in plasmonic sensing by modifying them with glucose oxidase and detection of glucose. The AuNSs were found to be a good scaffold for the enzyme, proved to be stable and sensitive as transducers. Thus, the AuNSs showed good promise for further applications in plasmonic biosensing for in vivo biomedical diagnosis.

scholarly journals Anisotropic growth is achieved through the additive mechanical effect of material anisotropy and elastic asymmetry

2018 ◽  
Author(s):  
Firas Bou Daher ◽  
Yuanjie Chen ◽  
Behruz Bozorg ◽  
Jack Clough ◽  
Henrik Jönsson ◽  
...  
Keyword(s):  
Cell Wall ◽  
Growth Characteristic ◽  
Growth Control ◽  
Mechanical Effect ◽  
Anisotropic Growth ◽  
Hypocotyl Growth ◽  
Differential Growth ◽  
Directional Growth ◽  
Additive Combination ◽  
Shoot Meristems

AbstractFast directional growth is a necessity for the young seedling: after germination, the seedling needs to quickly reach through the soil to begin its autotrophic life. In most dicot plants, this rapid escape is due to the anisotropic elongation of the hypocotyl, the columnar organ between the root and the shoot meristems. Such anisotropic growth is common in many plant organs and is canonically attributed to cell wall anisotropy produced by oriented cellulose fibers in the cell wall. More recently, a mechanism based on asymmetric cell wall elasticity has been proposed, produced by differential pectin biochemistry. Here we present a harmonizing model for anisotropic growth control in the dark-grown Arabidopsis hypocotyl: basic anisotropic information is provided by cellulose orientation (proxied by microtubules) and additive anisotropic information is provided by pectin-based elastic asymmetry in the epidermis. We demonstrate that hypocotyl growth was always anisotropic with axial and transverse walls growing differently, from germination. We present experimental evidence for pectin biochemical differences and wall mechanics underlying this differential growth. We demonstrate that pectin biochemical changes control the transition to rapid growth characteristic of Arabidopsis hypocotyl elongation, and provide evidence for a substantial mechanical role for pectin in the cell wall when microtubules are compromised. Lastly, our in silico modelling experiments indicate an additive combination for pectin biochemistry and cellulose orientation in promoting anisotropic growth.

Gold nanorod synthesis catalysed by Au clusters

2016 ◽  
Vol 191 ◽  
pp. 205-213 ◽  
Author(s):  
Yasser A. Attia ◽  
Carlos Vázquez-Vázquez ◽  
M. Carmen Blanco ◽  
David Buceta ◽  
M. Arturo López-Quintela
Keyword(s):  
Aspect Ratio ◽  
Gold Nanorods ◽  
Growth Control ◽  
Reaction Times ◽  
Good Control ◽  
Silver Ions ◽  
Gold Nanorod ◽  
Anisotropic Growth ◽  
Simple Scheme ◽  
Au Clusters

Gold nanorods have been successfully synthesized by the seed mediated method using Au clusters. This synthesis does not require silver ions to obtain large amounts of Au nanorods and has good control over their aspect ratio. Au clusters are produced with the same recipe as for Au seeds, but using shorter reaction times. This very simple scheme confirms the important catalytic influence of clusters in the anisotropic growth control.

scholarly journals Anisotropic growth is achieved through the additive mechanical effect of material anisotropy and elastic asymmetry

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Firas Bou Daher ◽  
Yuanjie Chen ◽  
Behruz Bozorg ◽  
Jack Clough ◽  
Henrik Jönsson ◽  
...  
Keyword(s):  
Cell Wall ◽  
Growth Regulation ◽  
Growth Control ◽  
Cellulose Fibers ◽  
Mechanical Effect ◽  
Anisotropic Growth ◽  
Material Anisotropy ◽  
Directional Growth ◽  
Cell Wall Elasticity ◽  
Shoot Meristems

Fast directional growth is a necessity for the young seedling; after germination, it needs to quickly penetrate the soil to begin its autotrophic life. In most dicot plants, this rapid escape is due to the anisotropic elongation of the hypocotyl, the columnar organ between the root and the shoot meristems. Anisotropic growth is common in plant organs and is canonically attributed to cell wall anisotropy produced by oriented cellulose fibers. Recently, a mechanism based on asymmetric pectin-based cell wall elasticity has been proposed. Here we present a harmonizing model for anisotropic growth control in the dark-grown Arabidopsis thaliana hypocotyl: basic anisotropic information is provided by cellulose orientation) and additive anisotropic information is provided by pectin-based elastic asymmetry in the epidermis. We quantitatively show that hypocotyl elongation is anisotropic starting at germination. We present experimental evidence for pectin biochemical differences and wall mechanics providing important growth regulation in the hypocotyl. Lastly, our in silico modelling experiments indicate an additive collaboration between pectin biochemistry and cellulose orientation in promoting anisotropic growth.

Quantitative EM of gap junction distribution in mutant drosophila wing discs

1983 ◽  
Vol 41 ◽  
pp. 720-721
Author(s):  
J.S. Ryerse
Keyword(s):  
Gap Junctions ◽  
Growth Control ◽  
Intercellular Junctions ◽  
Wing Disc ◽  
En Bloc ◽  
Metabolic Cooperation ◽  
Drosophila Wing ◽  
Adult Wing ◽  
Wing Discs ◽  
Wing Pouch

Gap junctions are intercellular junctions found in both vertebrates and invertebrates through which ions and small molecules can pass. Their distribution in tissues could be of critical importance for ionic coupling or metabolic cooperation between cells or for regulating the intracellular movement of growth control and pattern formation factors. Studies of the distribution of gap junctions in mutants which develop abnormally may shed light upon their role in normal development. I report here the distribution of gap junctions in the wing pouch of 3 Drosophila wing disc mutants, vg (vestigial) a cell death mutant, 1(2)gd (lethal giant disc) a pattern abnormality mutant and 1(2)gl (lethal giant larva) a neoplastic mutant and compare these with wildtype wing discs.The wing pouch (the anlagen of the adult wing blade) of a wild-type wing disc is shown in Fig. 1 and consists of columnar cells (Fig. 5) joined by gap junctions (Fig. 6). 14000x EMs of conventionally processed, UA en bloc stained, longitudinally sectioned wing pouches were enlarged to 45000x with a projector and tracings were made on which the lateral plasma membrane (LPM) and gap junctions were marked.

Ultrastructural features of prognostic significance in human oral cancer

1992 ◽  
Vol 50 (1) ◽  
pp. 618-619
Author(s):  
Karvita B. Ahluwalia ◽  
Nidhi Sharma
Keyword(s):  
Oral Cancer ◽  
Squamous Cell ◽  
Common Knowledge ◽  
Prognostic Significance ◽  
Growth Control ◽  
Terminal Differentiation ◽  
Squamous Cell Carcinomas ◽  
Effective Therapy ◽  
Invasive Potential ◽  
Biological Behaviour

It is common knowledge that apparently similar tumors often show different responses to therapy. This experience has generated the idea that histologically similar tumors could have biologically distinct behaviour. The development of effective therapy therefore, has the explicit challenge of understanding biological behaviour of a tumor. The question is which parameters in a tumor could relate to its biological behaviour ? It is now recognised that the development of malignancy requires an alteration in the program of terminal differentiation in addition to aberrant growth control. In this study therefore, ultrastructural markers that relate to defective terminal differentiation and possibly invasive potential of cells have been identified in human oral leukoplakias, erythroleukoplakias and squamous cell carcinomas of the tongue.

Microstructural investigation of surface roughness in MBE-grown AlAs

1995 ◽  
Vol 53 ◽  
pp. 454-455
Author(s):  
R. Rajesh ◽  
R. Droopad ◽  
C. H. Kuo ◽  
R. W. Carpenter ◽  
G. N. Maracas
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Growth Control ◽  
Native Oxide ◽  
Effusion Cell ◽  
Surface Oxide Layer ◽  
Microstructural Investigation ◽  
Mbe Growth ◽  
Film Substrate ◽  
And Control

Knowledge of material pseudodielectric functions at MBE growth temperatures is essential for achieving in-situ, real time growth control. This allows us to accurately monitor and control thicknesses of the layers during growth. Undesired effusion cell temperature fluctuations during growth can thus be compensated for in real-time by spectroscopic ellipsometry. The accuracy in determining pseudodielectric functions is increased if one does not require applying a structure model to correct for the presence of an unknown surface layer such as a native oxide. Performing these measurements in an MBE reactor on as-grown material gives us this advantage. Thus, a simple three phase model (vacuum/thin film/substrate) can be used to obtain thin film data without uncertainties arising from a surface oxide layer of unknown composition and temperature dependence.In this study, we obtain the pseudodielectric functions of MBE-grown AlAs from growth temperature (650°C) to room temperature (30°C). The profile of the wavelength-dependent function from the ellipsometry data indicated a rough surface after growth of 0.5 μm of AlAs at a substrate temperature of 600°C, which is typical for MBE-growth of GaAs.

Smart Plant Growth Control and Monitoring System for Indoor Hydroponic Farming

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Fina Supegina
Keyword(s):  
Water Level ◽  
Monitoring System ◽  
Growth Control ◽  
Set Point ◽  
Water Solvent ◽  
Growth Room ◽  
Smart Control ◽  
Level Sensor ◽  
Planting Method ◽  
Hydroponic Growth

Hydroponics is one of planting method that use water as a medium of plants growth, in this technique, mineral solution added into the water solvent, allowing the nutrient uptake process by the plants.  Farming by hydroponic method must pay attention to the following parameters namely, temperature, humidity, the level of water needs and nutrients and also the level of sunlight need for photosynthesis process.  This research used hydroponic technique in hydroponic growth room, and  there is a LED growth light as an alternate of sunlight, due to this room is closed without sunlight.  There are outputs displayed in monitoring system namely, temperature sensor, humidity sensor, ultrasound sensor to detect height of the plant and water level sensor to measured height of the water as a medium of the plant.  Results of measured sensor in hydroponic growth room explained as the following:  fan cooler worked when temperature , and humidity  .  Water pump worked when water level is less than 50% accordance set point.  Control on LED Growth Light and LED Bulb when LDR sensor reached set point > 500 in bright condition, and < 500 in dark condition respectively. The average of Time update/received data in thing speak web is 2.4 second. Keywords: Smart Control, Hydroponic, IoT, Monitoring

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