spherical form
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2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Hui Lu ◽  
Honoka Aida ◽  
Masaomi Kurokawa ◽  
Feng Chen ◽  
Yang Xia ◽  
...  

AbstractThe morphology of primitive cells has been the subject of extensive research. A spherical form was commonly presumed in prebiotic studies but lacked experimental evidence in living cells. Whether and how the shape of living cells changed are unclear. Here we exposed the rod-shaped bacterium Escherichia coli to a resource utilization regime mimicking a primordial environment. Oleate was given as an easy-to-use model prebiotic nutrient, as fatty acid vesicles were likely present on the prebiotic Earth and might have been used as an energy resource. Six evolutionary lineages were generated under glucose-free but oleic acid vesicle (OAV)-rich conditions. Intriguingly, fitness increase was commonly associated with the morphological change from rod to sphere and the decreases in both the size and the area-to-volume ratio of the cell. The changed cell shape was conserved in either OAVs or glucose, regardless of the trade-offs in carbon utilization and protein abundance. Highly differentiated mutations present in the genome revealed two distinct strategies of adaption to OAV-rich conditions, i.e., either directly targeting the cell wall or not. The change in cell morphology of Escherichia coli for adapting to fatty acid availability supports the assumption of the primitive spherical form.


2021 ◽  
Vol 7 (2) ◽  
pp. 108-117
Author(s):  
Ngatijo Ngatijo ◽  
Restina Bemis ◽  
Heriyanti Heriyanti ◽  
Rahmi Rahmi ◽  
Nashih Ulwan ◽  
...  

Carbonated calcium hydroxyapatite (CHAp) exhibits excellent biocompatibility with bone and teeth, making it an ideal candidate for orthopedic and dental application. However, the study of CHAp synthesis from natural material is still scarce. The purpose of this research is to synthesize and characterize of CHAp, using Rebon shrimp (Acetes erythraeus) as a calcium source. The synthesis was conducted by hydrothermal method with the variation of Ca/P ratios 1.61; 1.67; 1.73. The as-prepared CHAp was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX). The FT-IR results show that synthesized material exhibited characteristic CHAp band of hydroxide at 3448 and 1635 cm-1, carbonate at 872 and 1427 cm-1, and phosphate at 1049; 606; and 570 cm-1. The diffractogram pattern assigned the all observed peak of CHAp are in good agreement compared to CHAp database with the nano-scale size. It also observed that the high Ca/P ratio will decrease the crystallinity of CHAp. The as-prepared CHAp micrograph is agglomerates spherical form with size between 5-20 nm which build up from 18–26 nm crystallite particles. The result of this research confirmed that Rebon shrimp is the promising materials for calcium source in CHAp production.


Molekul ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 170
Author(s):  
Salprima Yudha S ◽  
Aswin Falahudin ◽  
Morina Adfa ◽  
Irfan Gustian ◽  
Herlina Herlina

The aqueous extract of Rivina humilis was suitable to reduce silver ions (Ag+) to form micron-sized metallic silver at room temperature and without any addition of external reducing agent or stabilizer compounds. The reduction process was assisted by light, indicated by the colour change of the reaction mixture and supported by the appearance of peak at 455 nm in spectrophotometric analysis when the reaction was carried out under room light. Based on transmission electron microscopy (TEM) analysis, the as-prepared metallic silver was in spherical form. The analysis results using particles size analyzer (PSA) show their particles distribution from micro to nano size (average size was 199 nm). The interaction behaviour of micron-sized metallic silver/extract solution with Corptotermes curvignathus termites shows that the silver gives small additional effects along with the activity of the extract.


2021 ◽  
Author(s):  
Noriaki Sagata ◽  
Yasunari Sakai ◽  
Takahiro A. Kato

Direct conversion techniques, which generate induced-neuronal (iN) cells from human fibroblasts in less than two weeks, are expected to discover unknown neuronal phenotypes of neuropsychiatric disorders. Here, we present unique gene expression and cell morphology profiles in iN cells derived from neurofibromatosis type 1 (NF1) patients. NF1 is a single-gene multifaceted disorder with relatively high co-occurrence of autism spectrum disorder (ASD). Adenylyl cyclase (AC) dysfunction is one of the candidate pathways in abnormal neuronal development in the brains of NF1 patients. In our study, microarray-based transcriptomic analysis of iN cells from healthy controls (males) and NF1 patients (males) revealed significantly different gene expression of 149 (110 were upregulated and 39 were downregulated). In iN cells derived from NF1 patients (NF1-iN cells), there was a change in the expression level of 90 genes with the addition of forskolin, an AC activator. Furthermore, treatment with forskolin dramatically changed the cell morphology, especially that of NF1-iN cells, from flat-form to spherical-form. Current pilot data indicate the potential therapeutic effect of forskolin or AC activators on neuronal growth in NF1 patients. Further translational research is needed to validate the pilot findings for future drug development of ASD.


2021 ◽  
Vol 25 (7) ◽  
pp. 114-123
Author(s):  
Pawan P. Kalbende

A functional role of plant latex extract in the growth and nucleation of silver nanoparticles synthesized by green method has been discussed. By varying the biological species as capping and reducing agents, silver nanoparticles (AgNPs) of different morphologies under similar reaction conditions were produced. The synthetic protocol involves the preparation of AgNPs derived from two plant latex extract i.e. plumeria obtusa and manilkara zapota. Synthesized AgNPs generate the surface plasmonic resonance peak at 435 nm in UV–Visible spectrophotometer. Fourier-transform infrared spectroscopy (FT-IR) analysis shows the major role of active phenolic constituents and protein in reduction and stabilization of AgNPs. Size and shape of AgNPs were characterized through transmission electron microscopy (TEM) which shows that the AgNPs are of spherical form and relatively uniform. X-ray diffraction (XRD) pattern of AgNPs corresponding to (111), (200), (220) and (311) planes reveals that the generated nanoparticles were face centered cubic crystalline in nature. The average crystalline size was found to be 32.97 and 35.15 nm for plumeria obtusa and manilkara zapota respectively. The role of capping agents in controlling the size and properties of silver nanoparticles has been studied. Phyto-fabricated AgNPs exhibit significant antimicrobial activity against Staphylococcus aures and Escherichia coli.


2021 ◽  
Vol 5 (1) ◽  
pp. 75-81
Author(s):  
Anatolij Kobziev ◽  
Mykhailo Murzin

Direction finding networks have found application in radio monitoring, radio intelligence and passive radar systems. The operation of the direction-finding network in the short-wave range has a number of distinctive features, namely, long range of direction finders (up to several thousand km) due to ionospheric propagation of radio waves and high sensitivity of narrow-band signal receivers. In addition, the distance between direction finders can be hundreds or thousands of kilometers. Therefore the calculations should be carried out due to the location of the direction finders and radio sources on a spherical surface. In this work, analytical relationships are obtained for calculating the accuracy indicators of the estimation of coordinate information (latitude and longitude) at the output of the direction finding network in a rather general form in relation to the features of the short-wave range. The problem is solved in a geographic coordinate system for an arbitrary number of direction finders (two at least) and with their arbitrary location on the surface of Earth. To carry out a comparative analysis and assess the quality of coordinate information for various options for placing direction finders, it is proposed to display accuracy indicators using working zones (for example, round). The use of working areas allows a visual assessment on the map overall spatial pattern for accuracy indicators direction-finding network. The results of the calculation of working areas direction-finding network shortwave when placing it on the territory of Ukraine in the case of the smallest real errors direction-finding, and a mutual separation distance finders maximum permissible selected. The calculation results reflect the limiting possibilities for the accuracy of determining the coordinates of radio emission sources for such a direction finding network with a minimum number of direction finders (3 or 4). The given method of calculating working zones allows for the implementation of the best accuracy indicators to choose a specific option for placing direction finders on the territory of the country, taking into account the influence of all factors (approach of positions, availability of access roads, conditions for accommodating service personnel, etc.). As an example, the work considers 3 options for the location of direction finders with the maximum separation on the territory of Ukraine. The developed technique can also be used for other passive radar systems with direction finding coordinates, when it is necessary to take into account the spherical form of the Earth. Such a system can include two or more aerial reconnaissance aircraft with direction finders on board, as well as one aircraft or unmanned vehicle that determines coordinates by the method of multiple direction finding on the flight route.


2021 ◽  
Vol 12 (1) ◽  
pp. 1022-1038

Mesoporous iron oxide nanospheres (MINs) have been successfully synthesized and have proven to be high-efficiency adsorbents. The morphology of the MINs is very uniform in spherical form, with an average particle size of 23-27 nm in the diameter range. MINs content has a fairly high BET surface area of 188.25 m2g−1 and a total volume of 0.14 cm3g−1 pores. Thus, seams were seen as potential CO2 sequestration reservoirs to reduce greenhouse gas emissions. The CO2 adsorption was favorable at low temperature and dry MINs conditions. However, MINs have a high adsorption capacity of 0.15 mmol/g. The CO2 adsorption isotherm of all coal samples according to the IUPAC classification of adsorption isotherms fits category I, which most likely explains adsorption confined to a few layers of molecules (micropores and mesopores). The balancing assessment using Langmuir, Henry, Dubbin, Temkin, Toth, Harkins-Jura, Elovich, Redlich-Peterson, and Josene model provided the best fit for any experimental adsorption data that predict heterogeneous surface properties of MINs.


The green emitting phosphor based on manganese activated zinc silicate was successfully synthesized by the sol – gel method using hydrochloric acid. The suitable molar ratio of the initial components is Zn(CH3COO)2: MnSO4: TEOS = 1.98: 0.02: 1 corresponding to the product formula Zn1.98Mn0,02SiO4. The suitable pH value for the gelation is 3, ratio of water phase: ethanol phase = 1:1 and the product when calcining the obtained gel at 10000C for 60 minutes has highest luminescence intensity. The synthesized phosphor consists of Zn2SiO4 with rhombohedral structure and emits a green light at the 525 nm wavelength when excited by the 325 nm UV radiation. The produced sample has spherical form with the particles size being 100 nm.


2021 ◽  
Vol 79 (1) ◽  
pp. 1-14
Author(s):  
Genaro Diarte-Plata ◽  
Ruth Escamilla-Montes ◽  
Salvador Granados-Alcantar ◽  
Antonio Luna-González

Abstract Macrobrachium americanum has a high commercial value with good fishing and cultivation possibilities in Mexico. Currently there is little information on reproductive aspects so the present work analyzed the sex ratio, fecundity and morphometry of the eggs of M. americanum in the Petatlán River, Sinaloa, Mexico. A total of 31 ovigerous females were captured. The sex ratio was 0.39 F: 1 M. The partial fecundity (Pf) varied from 34, 554 to 342, 372 eggs (128, 246 ± 12, 306 eggs, average Pf). The relationships between body and length-fecundity (R2= 0.5546), cephalothorax and length-fecundity (R2= 0.4995) were adjusted to a linear model, and the total weight-fecundity to a potential model (R2= 0.5013). The average relative fecundity was 37, 132 ± 5, 162 eggs/g. A total of 7 stages of embryonic development were observed. In the first stages, the egg presents a spherical form and in the latter an ovoid shape. Maximum egg diameter values are presented in stages VII, VI and VIII. Stage II provided the largest number of eggs (1, 013, 073 eggs). It is essential to optimize the exploitation of the population of M. americanum present in the Petatlán River through the creation of scientific bases for the sustainability of the fishery.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 342
Author(s):  
Elisa Fracchia ◽  
Federico Simone Gobber ◽  
Mario Rosso

Strontium-based modifier alloys are commonly adopted to modify the eutectic silicon in aluminum-silicon casting alloys by changing the silicon shape from an acicular to a spherical form. Usually, the modifier alloy necessary to properly change the silicon shape depends on the silicon content, but the alloying elements’ content may have an influence. The AlSr10 master alloy’s modifying effect was studied on four Al-Si alloys through the characterization of microstructural and mechanical properties (micro-hardness and impact tests). The experimental results obtained on gravity cast samples highlighted the interdependence in the modification of silicon between the Si content and the alloying elements. After modification, a higher microstructural homogeneity characterized by a reduction of up to 22.8% in the size of intermetallics was observed, with a generalized reduction in secondary dendritic arm spacing. The presence of iron-based polygonal-shaped intermetallics negatively affects Sr modification; coarser silicon particles tend to grow close to α-Fe. The presence of casting defects such as bifilm reduces Sr modification’s beneficial effects, and little increase in absorbed impact energy is observed in this work.


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