scholarly journals Experimental test of the sample reduction random error formula

2021 ◽  
pp. 37-44
Author(s):  
Ekaterina Stupakova ◽  
Keyword(s):  
Form Factor ◽  
Granulometric Composition ◽  
Analytical Formula ◽  
Maximum Size ◽  
Free Form ◽  
Relative Reduction ◽  
Case Methodology ◽  
Sample Composition ◽  
Reduction Error ◽  
First Time

Introduction. An immediate estimate of the accidental error of sample reduction can only be made if the measurement method of execution is zero. This can be achieved by imitating the grains of a useful component with markers fully extracted from the reduced sample. The markers can be larger than 44 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 4. 2021 ISSN 0536-1028 the maximum size of the sample material and are extracted from the sample using screens. Markers whose granulometric composition matches the sample composition should be extracted completely from the reduced sample using a hand magnet in the case. Methodology. A small number of markers of the correct shape imitates forgeable gold grains or d99 platinum. A much larger number of free-form markers simulate the granulometric composition of a sample in the –1+0.5 mm class. It is necessary to find a form factor linking the particles real volume with the cube volume. For magnetite markers, the form factor is 0.4. Results and analysis. The samples have been reduced with regular shaped and free-form markers, which makes it possible to experimentally determine the error of reduction. Theoretical formulas found errors for the conditions of experiments. For experiments with the regular shaped markers, a 54.77– 58.43% relative reduction error has been obtained according to 480 parallel measurements. Theoretically determined 57.64% relative error falls into this range. Similar relative reduction errors with free-form markers are 8.82–10.00% and 9.15%. Conclusion. The fairness of the reduction error analytical formula has been directly evaluated for the first time. The reduction error analytical formula can be applied when analyzing the schemes of sample preparation.

scholarly journals Comparison of α-Tocopherol, α-Tocopherol Acetate, and α-Tocopheryl Polyethylene Glycol Succinate 1000 Absorption by Caco-2 TC7 Intestinal Cells

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 129
Author(s):  
Charlotte Cuerq ◽  
Claire Bordat ◽  
Charlotte Halimi ◽  
Emilie Blond ◽  
Marion Nowicki ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
High Performance ◽  
Lipid Extraction ◽  
Free Form ◽  
Glycol Succinate ◽  
Tocopherol Acetate ◽  
Apical Side ◽  
Basolateral Side ◽  
Human Enterocyte ◽  
First Time

(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p < 0.001); and (iii) significantly lower with the TPGS form (p < 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.

scholarly journals Nanoliposomal Cercodemasoide A and Its Improved Activities Against NTERA-2 Cancer Stem Cells

2020 ◽  
Vol 15 (12) ◽  
pp. 1934578X2098210
Author(s):  
Nguyen Thi Nga ◽  
Do Thi Phuong ◽  
Nguyen Thi Cuc ◽  
Trieu Ha Phuong ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Drug Carrier ◽  
Free Form ◽  
Cancer Therapies ◽  
3 Dimensional ◽  
Novel Target ◽  
Average Size ◽  
Biopharmaceutical Properties ◽  
First Time

Recently, saponins derived from marine sources have received much attention because of their promising bioactivities, such as anticancer, anti-angiogenesis, and anti-inflammation. In particular, a triterpene saponin from the sea cucumber Cercodemas anceps Selenka, cercodemasoide A (CAN1), showed potent cytotoxicity against various cancer cell lines. Recent evidence has indicated that cancer stem cells (CSCs) could be a novel target for efficient cancer therapies. In order to improve the biopharmaceutical properties of CAN1, the compound was loaded into nanoliposomes as an ideal drug carrier. CAN1 was successfully incorporated into nanoliposomes as small unilamellar liposome vesicles with an average size of 73.39 ± 1.57 nm, zeta potential of −0.299 ± 0.046 mV, polydispersity index of 0.336 ± 0.038, and with an encapsulation efficiency of up to 62.9%. For the first time, CAN1 and its nanoliposomal forms have been shown to have a promising cytotoxic activity against NTERA-2 CSCs, with half-maximal inhibitory concentration (IC50) =1.03 ± 0.04 and 0.41 ± 0.03 µM, respectively. The CAN1 nanoliposomes also presented significantly improved activities in suppressing the growth of NTERA-2 3-dimensional tumorspheres (IC50 = 1.71 ± 0.06 µM) in comparison with the free form ( P < .05). The anti-CSC effects of CAN1 nanoliposomes on NTERA-2 cells were due to their apoptotic induction through enhancing caspase-3 activity (more than 2-fold) and arresting the cell cycle at the S phase ( P < .05). The obtained CAN1-encapsulated nanoliposomes suggest valuable applications in CSC-targeting treatment for more efficient clinical therapy.

scholarly journals Immobilization of Eversa Lipase on Octyl Agarose Beads and Preliminary Characterization of Stability and Activity Features

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 511 ◽  
Author(s):  
Sara Arana-Peña ◽  
Yuliya Lokha ◽  
Roberto Fernández-Lafuente
Keyword(s):  
Immobilized Enzyme ◽  
Biodiesel Production ◽  
Free Form ◽  
Enzyme Specificity ◽  
Agarose Beads ◽  
The Stability ◽  
Isoform B ◽  
First Time ◽  
Commercial Lipase

Eversa is an enzyme recently launched by Novozymes to be used in a free form as biocatalyst in biodiesel production. This paper shows for first time the immobilization of Eversa (a commercial lipase) on octyl and aminated agarose beads and the comparison of the enzyme properties to those of the most used lipase, the isoform B from Candida antarctica (CALB) immobilized on octyl agarose beads. Immobilization on octyl and aminated supports of Eversa has not had a significant effect on enzyme activity versus p-nitrophenyl butyrate (pNPB) under standard conditions (pH 7), but immobilization on octyl agarose beads greatly enhanced the stability of the enzyme under all studied conditions, much more than immobilization on aminated support. Octyl-Eversa was much more stable than octyl-CALB at pH 9, but it was less stable at pH 5. In the presence of 90% acetonitrile or dioxane, octyl-Eversa maintained the activity (even increased the activity) after 45 days of incubation in a similar way to octyl-CALB, but in 90% of methanol, results are much worse, and octyl-CALB became much more stable than Eversa. Coating with PEI has not a clear effect on octyl-Eversa stability, although it affected enzyme specificity and activity response to the changes in the pH. Eversa immobilized octyl supports was more active than CALB versus triacetin or pNPB, but much less active versus methyl mandelate esters. On the other hand, Eversa specificity and response to changes in the medium were greatly modulated by the immobilization protocol or by the coating of the immobilized enzyme with PEI. Thus, Eversa may be a promising biocatalyst for many processes different to the biodiesel production and its properties may be greatly improved following a suitable immobilization protocol, and in some cases is more stable and active than CALB.

Enzymatic Hydrolysis of Carotenoid Fatty Acid Esters of Red Pepper (Capsicum annuum L.) by a Lipase from Candida rugosa

2000 ◽  
Vol 55 (11-12) ◽  
pp. 971-975 ◽  
Author(s):  
Dietmar Ernst Breithaupt
Keyword(s):  
Enzymatic Hydrolysis ◽  
Candida Rugosa ◽  
Fatty Acid Esters ◽  
Red Pepper ◽  
Free Form ◽  
Enzymatic Cleavage ◽  
Reaction Conditions ◽  
First Time ◽  
Hydrolysis Of ◽  
Acid Esters

Analyses of red pepper extracts which had been pretreated with lipase type VII (EC 3.1.1.3.) from Candida rugosa showed for the first time pepper carotenoid esters to be substrates of this enzyme. However, the extent of enzymatic hydrolysis depends on the respective carotenoid and was not quantitative compared to chemical saponification. After enzymatic cleavage, 67-89% of total capsanthin, 61-65% of total zeaxanthin, 70-81% of total β-cryptoxanthin and 70-86% of total violaxanthin were detected in free form. Nevertheless, the method described here offers the possibility to cleave in part several carotenoid esters originating from red pepper quickly and under comparatively mild reaction conditions. Replacement of the generally performed alkaline hydrolysis by enzymatic cleavage allows the resulting product to be used in food industry as “natural” coloring agent e.g. to colour cheese and jellies.

THE THOMAS–FERMI–GOMBÁS ATOM MODELS IN WHICH THE ELECTRONS ARE GROUPED INTO n- AND nl-SHELLS AND A CALCULATION OF THE ATOMIC FORM FACTOR

2004 ◽  
Vol 18 (03) ◽  
pp. 409-419
Author(s):  
V. F. TARASOV
Keyword(s):  
Form Factor ◽  
Kinetic Energy ◽  
Total Energy ◽  
Hypergeometric Functions ◽  
Fermi Theory ◽  
Thomas Fermi ◽  
Atomic Form Factor ◽  
First Time ◽  
Analytical Expressions ◽  
Gradient Correction

This article, considers in detail P. Gombás's idea of grouping electrons into n- and nl-shells in the Thomas–Fermi theory of free atoms briefly, the TFG n- and TFG nl-models respectively). Using these models, exact analytical expressions for the total energy E and the atomic form factor F(κ) are obtained. All integrals of the TFG nl-model are computed by means of the hypergeometric functions 2F1(x), 3F2(x), F2(x,y) and FA(x1,…,x6) for the first time. In particular, Weizsäcker's gradient correction to the kinetic energy of the nl-th shell [Formula: see text] generates a new numerical triangle [Formula: see text] with coefficients bw=n+2l(n-l-1).

scholarly journals Predictions on the alpha decay chains of superheavy nuclei with Z = 121 within the range 290 ≤ A ≤ 339

2016 ◽  
Vol 25 (10) ◽  
pp. 1650079 ◽  
Author(s):  
K. P. Santhosh ◽  
C. Nithya
Keyword(s):  
Spontaneous Fission ◽  
Potential Model ◽  
Analytical Formula ◽  
Superheavy Element ◽  
Alpha Decay ◽  
Mass Range ◽  
Universal Curve ◽  
Proximity Potential ◽  
Deformed Nuclei ◽  
First Time

A systematic study on the alpha decay half-lives of various isotopes of superheavy element (SHE) [Formula: see text] within the range [Formula: see text] is presented for the first time using Coulomb and proximity potential model for deformed nuclei (CPPMDN). The calculated [Formula: see text] decay half-lives of the isotopes within our formalism match well with the values computed using Viola–Seaborg systematic, Universal curve of Poenaru et al., and the analytical formula of Royer. In our study by comparing the [Formula: see text] decay half-lives with the spontaneous fission half-lives, we have predicted [Formula: see text] chain from [Formula: see text]121, [Formula: see text] chain from [Formula: see text]121 and [Formula: see text] chain from [Formula: see text]121. Clearly our study shows that the isotopes of SHE [Formula: see text] within the mass range [Formula: see text] will survive fission and can be synthesized and detected in the laboratory via alpha decay. We hope that our predictions will provide a new guide to future experiments.

scholarly journals Effect of Microencapsulation on the Development of Antioxidant Activity and Viability of Lactobacillus acidophilus LA5 in Whey Drink During Fermentation

2020 ◽  
Vol 11 (2) ◽  
pp. 9762-9771
Keyword(s):  
Antioxidant Activity ◽  
Storage Time ◽  
Free Form ◽  
Antiradical Properties ◽  
Gastrointestinal Conditions ◽  
Eudragit S100 ◽  
Encapsulation Process ◽  
Encapsulated Bacteria ◽  
Functional Drink ◽  
First Time

Encapsulation could be used for increasing of probiotic’s viability and maintaining of product’s quality during storage. The encapsulation process was performed using alginate-resistant starch and Eudragit S100 nanoparticles and by the extrusion technique. In whey drink, the viability of encapsulated L. acidophilus was upper in comparison to the free probiotic bacteria (P=0.001). The viability of bacteria reduced significantly during the study (P<0.001 in both groups), and encapsulated bacteria were more stable during the storage time than free forms (P=0.046). In gastrointestinal conditions, the viability of bacteria was reduced significantly during the 120 min study period in both groups (P<0.001 for free form and P=0.001 for microencapsulated bacteria). Encapsulated bacteria were more stable than free form (P<0.001). Free bacteria containing whey products exhibited an increasing antioxidant activity from beginning day to the fifth week (0.1-2.6 mmol Trolox equivalents/mL sample). Whey drinks with encapsulated bacteria showed similar antiradical properties for the first time, but their increasing activity rate within 35 days was lower than free form samples (0.1-0.9 mmol Trolox equivalents/mL sample). This technique of encapsulation can prevent bacteria from reducing their survivability. Whey products prepared using L. acidophilus (especially in free form) could be considered as a potent antioxidant functional drink.

NPR-B Expression In Megakaryocytes and Platelets

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4319-4319
Author(s):  
Sinny Delacroix ◽  
Brian J Boylan ◽  
Adriana Harbuzariu ◽  
Peter J Psaltis ◽  
Shuchong Pan ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Colony Formation ◽  
Conflicts Of Interest ◽  
Guanosine Monophosphate ◽  
Single Amino Acid ◽  
Relative Reduction ◽  
Mutant Form ◽  
Cgmp Production ◽  
Independent Functions ◽  
First Time

Abstract Abstract 4319 C-type natriuretic peptide (CNP) is known to exert pleiotropic effects on a variety of cell types through binding to its receptor, natriuretic peptide receptor type B (NPR-B) and activation of the cytoplasmic intracellular guanylyl cyclase domain. Although nitric oxide-mediated activation of cyclic guanosine monophosphate (cGMP) is known to induce megakaryocyte apoptosis and regulate platelet activation, the effects of CNP on these cells is yet to be defined. In this study for the first time we have addressed the potential role of CNP and NPR-B in megakaryocyte and platelet biology. We identified NPR-B on murine megakaryocytes by immunostaining demonstrating co-localization of CD41 and NPR-B. CNP induced cGMP production in megakaryocytes compared to a mutant form of CNP containing a single amino acid substitution (Lbab) (67.24 ± 10.65 fmol/well vs. 17.18 ± 2.089 fmol/well; P<0.05). Subsequently, CNP was shown to reduce megakaryocyte colony formation compared to Lbab and this effect was dose-dependent: Lbab 500nM 26.75 ± 5.618 CFU-M vs. 15.25 ± 2.750 CFU-M for CNP 500nM and Lbab 1000 nM 27.50 ± 2.102 CFU-M vs. 12.25 ± 1.493 CFU-M for CNP 1000nM; P<0.05). Furthermore, CNP also resulted in smaller-sized colonies, with altered cell morphology. To verify these findings, wild-type C57/BL6 mice were treated with daily injections of either saline, 1uM CNP or 1uM Lbab for one week, following which megakaryocytes were isolated and cultured. Colony formation was diminished in mice injected with CNP compared to mice receiving saline or Lbab peptide (125.3 ± 18.54 CFU-M for saline; 107.0 CFU-M ± 20.04 for Lbab and 20.00 ± 3.674 CFU-M for CNP; P<0.05). In addition platelet numbers were measured in the aforementioned mice and the CNP treated mice had significantly lower platelet counts compared to the mice treated with Lbab (832.0 ± 13.19 ×103/ul for CNP vs. 778.0 ± 12.00 ×103/ul for Lbab; P<0.05). Taken together, these data indicate that CNP may play a role in the development, maturation and/or survival of megakaryocytes. Using flow cytometry we identified that 47% of CD41+ murine platelets co-express NPR-B. In addition, this expression of NPR-B was confirmed by immunocytostaining and western blotting in both human and murine platelets. Interestingly, despite the expression of NPR-B, and unlike megakaryocytes, CNP (similar to the mutant peptide) did not increase cGMP production in platelets (1.652 ± 0.016 fmol/well for CNP and 1.606 ± 0.01550 fmol/well for Lbab). Further, although preliminary results did not indicate that CNP alters platelet secretion or aggregation, exposure to the peptide profoundly inhibited adhesion of platelets to collagen (53 ± 5 adhered platelets with Lbab, 32 ± 3 with CNP, relative reduction 42%; P<0.05). In summary, these results provide for the first time evidence that the NPR-B receptor is expressed on both megakaryocytes and platelets. Our studies suggest that CNP might have both cGMP dependent and independent functions in megakaryocytes and platelets and further studies will assist in delineating the mechanisms by which CNP exerts its actions on these cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Luteal dynamics in goats: morphological and endocrine features

2010 ◽  
Vol 39 (9) ◽  
pp. 1937-1942 ◽  
Author(s):  
Eduardo Kenji Nunes Arashiro ◽  
João Henrique Moreira Viana ◽  
Jeferson Ferreira da Fonseca ◽  
Luiz Sérgio de Almeida Camargo ◽  
Carlos Antônio de Carvalho Fernandes ◽  
...  
Keyword(s):  
Sharp Decrease ◽  
Maximum Size ◽  
Tissue Growth ◽  
Corpora Lutea ◽  
Multiple Ovulation ◽  
Tissue Area ◽  
Luteal Tissue ◽  
The Moment ◽  
First Time ◽  
Endocrine Features

The aim of this study was to establish the morphologic and endocrine characteristics of luteal dynamics in goats. It was used Toggenburg female goats that showed natural estrus in a 48-hour interval. After estrus, ultrasonographic evaluations of the ovaries were daily performed during 21 days using a portable device (5MHz probe). Blood sample was collected for plasma progresterone (P4) determination. Corpora lutea were detected for the first time on day 5 and progressively increased in size until D9 (1.26 ± 0.08 cm²), with no variation on subsequent days. In females with one ovulation, the first visualization of the corpora lutea was earlier than in those with multiple ovulation (4.54 ± 0.18 vs 5.74 ± 0.25 days). At the moment of the first visualization, luteal area was smaller in animals with single ovulation. Plasma P4 concentration progressively increased until day 9 and it did not show significant increase until luteolysis, characterized by a sharp decrease in P4 concentration, reaching values below 1 ng/mL in 24 hours. The luteal area slowly and gradually decreased in size. It was observed a significant positive correlation between P4 concentration and area during luteogenesis and luteolysis (r = 0.63 and r = 0.50, respectively). When corpus luteum reached its maximum size (D9), female with more than one corpora lutea, with a greater luteal tissue area, did not show P4 concentration higher than those with one ovulation (5.92 ± 0.59 vs 7.04 ± 0.79 ng/mL). These results show that luteal dynamics in Toggenbur goats follow a similar pattern to those observed in other goat breeds and luteal tissue growth was positively correlated with corpora lutea functionality.

scholarly journals Extinction Moment for a Branching Tree Evolution with Birth Rate and Death Rate Both Depending on Age

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xi Hu ◽  
Yun-Zhi Yan ◽  
Zhong-Tuan Zheng ◽  
Hong-Yan Li ◽  
Hong-Yan Zhao
Keyword(s):  
Approximation Algorithm ◽  
Nuclear Physics ◽  
Death Rate ◽  
Birth Rate ◽  
Branching Process ◽  
Analytical Formula ◽  
Extinction Probability ◽  
Extinction Time ◽  
Necessary And Sufficient ◽  
First Time

In this paper, a branching tree evolution is established, in which the birth rate and the death rate are both dependent on node’s age. The extinction probability and the t-pre-extinction (extinct before time t ) probability are studied, by which the distribution of the extinction moment can be given. The analytical formula and the approximation algorithm for the distribution of extinction moment are given; furthermore, the analytical formula and the approximation algorithm of extinction probability are given, and a necessary and sufficient condition of extinction with probability 1 is given. It is the first time to study the distribution of extinction time for the branching process with birth rate and the death rate both depending on node’s age, and the results will do great help in the theory of branching process. It is expected to be applied in the fields of biology, genetics, medicine, epidemiology, demography, nuclear physics, actuarial mathematics, algorithm, and data structures, etc.

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