Data augmentation is a commonly used technique for increasing both the size and the diversity of labeled training sets by leveraging input transformations that preserve corresponding output labels. ...In computer vision, image augmentations have become a common implicit regularization technique to combat overfitting in deep learning models and are ubiquitously used to improve performance. While most deep learning frameworks implement basic image transformations, the list is typically limited to some variations of flipping, rotating, scaling, and cropping. Moreover, image processing speed varies in existing image augmentation libraries. We present Albumentations, a fast and flexible open source library for image augmentation with many various image transform operations available that is also an easy-to-use wrapper around other augmentation libraries. We discuss the design principles that drove the implementation of Albumentations and give an overview of the key features and distinct capabilities. Finally, we provide examples of image augmentations for different computer vision tasks and demonstrate that Albumentations is faster than other commonly used image augmentation tools on most image transform operations.
Echinoderms are marine invertebrates belonging to the phylum Echinodermata (from the Ancient Greek words "echinos" (hedgehog) and "derma" (skin)). ....
The article is a comprehensive review concerning tetracyclic triterpene and steroid glycosides from sponges (Porifera, Demospongiae). The extensive oxidative transformations of the aglycone and the ...use of various monosaccharide residues, with up to six possible, are responsible for the significant structural diversity observed in sponge saponins. The saponins are specific for different genera and species but their taxonomic distribution seems to be mosaic in different orders of Demospongiae. Many of the glycosides are membranolytics and possess cytotoxic activity that may be a cause of their anti-predatory activities. All these data reveal the independent origin and parallel evolution of the glycosides in different taxa of the sponges. The information concerning chemical structures, biological activities, biological role, and taxonomic distribution of the sponge glycosides is discussed.
Triterpene glycosides are characteristic secondary metabolites of sea cucumbers (Holothurioidea, Echinodermata). They have hemolytic, cytotoxic, antifungal, and other biological activities caused by ...membranotropic action. These natural products suppress the proliferation of various human tumor cell lines in vitro and, more importantly, intraperitoneal administration in rodents of solutions of some sea cucumber triterpene glycosides significantly reduces both tumor burden and metastasis. The anticancer molecular mechanisms include the induction of tumor cell apoptosis through the activation of intracellular caspase cell death pathways, arrest of the cell cycle at S or G2/M phases, influence on nuclear factors, NF-κB, and up-down regulation of certain cellular receptors and enzymes participating in cancerogenesis, such as EGFR (epidermal growth factor receptor), Akt (protein kinase B), ERK (extracellular signal-regulated kinases), FAK (focal adhesion kinase), MMP-9 (matrix metalloproteinase-9) and others. Administration of some glycosides leads to a reduction of cancer cell adhesion, suppression of cell migration and tube formation in those cells, suppression of angiogenesis, inhibition of cell proliferation, colony formation and tumor invasion. As a result, marked growth inhibition of tumors occurs in vitro and in vivo. Some holothurian triterpene glycosides have the potential to be used as P-gp mediated MDR reversal agents in combined therapy with standard cytostatics.
The article describes the structure-activity relationships (SAR) for a broad series of sea cucumber glycosides on different tumor cell lines and erythrocytes, and an in silico modulation of the ...interaction of selected glycosides from the sea cucumber
with model erythrocyte membranes using full-atom molecular dynamics (MD) simulations. The in silico approach revealed that the glycosides bound to the membrane surface mainly through hydrophobic interactions and hydrogen bonds. The mode of such interactions depends on the aglycone structure, including the side chain structural peculiarities, and varies to a great extent. Two different mechanisms of glycoside/membrane interactions were discovered. The first one was realized through the pore formation (by cucumariosides A
(
) and A
(
)), preceded by bonding of the glycosides with membrane sphingomyelin, phospholipids, and cholesterol. Noncovalent intermolecular interactions inside multimolecular membrane complexes and their stoichiometry differed for
and
The second mechanism was realized by cucumarioside A
(
) through the formation of phospholipid and cholesterol clusters in the outer and inner membrane leaflets, correspondingly. Noticeably, the glycoside/phospholipid interactions were more favorable compared to the glycoside/cholesterol interactions, but the glycoside possessed an agglomerating action towards the cholesterol molecules from the inner membrane leaflet. In silicosimulations of the interactions of cucumarioside A
(
) with model membrane demonstrated only slight interactions with phospholipid polar heads and the absence of glycoside/cholesterol interactions. This fact correlated well with very low experimental hemolytic activity of this substance. The observed peculiarities of membranotropic action are in good agreement with the corresponding experimental data on hemolytic activity of the investigated compounds in vitro.
The influence of the structural differences in titanium dioxide (TiO
2
- Degussa P25 and Mesh 325) as supporting materials for cobalt (Co) nanoparticles, has been revealed in aqueous and alkaline ...sodium borohydride (NaBH
4
) hydrolysis. The very little amount of Co nanoparticles, which was 2.2 and 1.5 wt%, has been successfully embedded on TiO
2
(P25) and TiO
2
(Mesh 325), respectively, via facile impregnation and magnetic separation method. The activation energies for TiO
2
(Mesh 325)/Co and TiO
2
(P25)/Co catalysts in the aqueous solution of NaBH
4
were 64.3 kJ
.
mol
−1
and 56.76 kJ
.
mol
−1
, respectively. On the other hand, the activation energy values of the hydrolysis process in alkaline NaBH
4
solutions using TiO
2
(Mesh 325)/Co and TiO
2
(P25)/Co catalysts have been calculated as 55 kJ
.
mol
−1
and 45.2 kJ
.
mol
−1
, respectively. Consequently, the hydrogen generation rate (HGR) for TiO
2
(Mesh 325)/Co and TiO
2
(P25)/Co in an aqueous-alkaline solution are 360 and 660 mL
.
min
.
g
cat
−1
, respectively which are twice higher in that of aqueous NaBH
4
hydrolysis reaction. The maximum HGR of 9000 mL.min
−1.
gcat
−1
for TiO
2
(P25) loaded with 2.2 wt% Co in an aqueous-alkaline solution at 60 °C, indicates this catalysis is very promising as the cost-effective catalytic hydrolysis of NaBH
4
.
Graphical Abstract
In this study, g-C
3
N
4
-TiO
2
nanocomposite structure has been loaded with Co
3
O
4
via electroless plating and thermal annealing to form Co
3
O
4
@g-C
3
N
4
-TiO
2
catalyst material for H
2
...generation from NaBH
4
hydrolysis. The material characterizations of the fabricated catalyst have been performed before and after exposure to an aqueous NaBH
4
solution to understand the changes in catalytic performance and material properties. The Arrhenius activation energies have been determined to be 58 kJ mol
−1
. The hydrogen generation rates have been observed as 180 and 1200 mL min
−1
g
cat
−1
for the catalyst hydrolysis of NaBH
4
at 30 °C and 60 °C, respectively. The catalytic activity performed in NaBH
4
solution exhibited good reusability.
Graphical Abstract
The book largely reflect the structural diversity of echinoderm metabolites including triterpene glycosides and fucosylated chondroitin sulfates, as well as branched fatty acids, di- and ...triacylglycerols and other lipid classes from the sea cucumbers, polyhydroxysteroids from starfish and different classes of sphingolipids from sea cucumbers and starfish. Finally, the MS-based metabolomic approach, which is very helpful for the estimation of such diversity, is discussed. The materials from the Special Issue also illustrate the biomedical potential of the presented metabolites as cytotoxins and anticoagulants. The in silico approach broadens the possibilities to investigate the mechanisms of the action of membranolytic compounds.
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