Determinación de sebo bovino en mantequilla utilizando un método integral

The detection of animal fats such as tallow in butter using standard criteria is more difficult than vegetable fats. In order to perform a complete assessment, several methods are likely to be used together. In the experimental design of this research, compositional characteristics such as fatty acids, sterols and triacylglycerols, along with the conventional physicochemical characteristics of butter mixed with different percentages of tallow (0–15% w/w) were evaluated. An increase of less than 5% (w/w) in bovine tallow content in butter physicochemical tests, sterols and fatty acids could not indicate the adulteration level but the ratio of C6+8+10+12/C18 fatty acids, C52/C50، C52/C48, C52/C46 triacylglycerols, S1, S3, S5-value equation and C52 triacylglycerols could show this adulteration level in butter. Also, the successive use of fatty acids and triacylglycerols resulted in the capability to determine adulteration in butter including bovine tallow above 1% (w/w).La detección de grasas animales, como el sebo en mantequilla, utilizando criterios estándares es más difícil que las grasas vegetales y esto probablemente se puede evaluar mediante la recopilación de métodos de evaluación y mediante un enfoque completo. En el diseño experimental de esta investigación, se evaluaron las características composicionales como los ácidos grasos, esteroles y triacilgliceroles junto con los índices fisicoquímicos convencionales, en mantequilla mezclada con un porcentaje diferente de sebo (0–15% p/p). Mediante un aumento de menos del 5% (p/p) de contenido de sebo bovino en mantequilla, las pruebas fisicoquímicas, los esteroles y los ácidos grasos no pudieron indicar el nivel de adulteración, pero sí lo hizo la relación de ácidos grasos C6+8+10+12/C18, la relación de triacilgliceroles C52C50; C52/C48; C52/C46; los valores de S1, S3, S5 en la ecuación y los triacilgliceroles C52. Además, el uso sucesivo de ácidos grasos y triacilgliceroles dio como resultado la capacidad de determinar la adulteración en la mantequilla, incluido el sebo bovino por encima del 1% (p/p)

Apigenin as Tumor Suppressor in Cancers: Biotherapeutic Activity, Nanodelivery, and Mechanisms With Emphasis on Pancreatic Cancer

Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer. © Copyright © 2020 Ashrafizadeh, Bakhoda, Bahmanpour, Ilkhani, Zarrabi, Makvandi, Khan, Mazaheri, Darvish and Mirzaei

Wind Energy Potential Assessment for Electric Pumps of Agriculture in Broujerd

In order to restrain the potential of wind energy, the first step is to determine the wind energy potential. In this study the wind data was used from the three-hour frequency recording of 10-year period (2002-2011). To predict the occurrence probability of each wind speed, the two-parameter Weibull function was used. The goodness of fit test by Chi-Square test showed that the wind speed distribution is not represented by the typical two- parameter Weibull function for all the months. Weibull probability density function has a good fit for eleven months, but for the 9th month of the year (September), it is not fitted. Thus, four-parameter Weibull probability function has been developed to analyze the wind speed frequency distribution in that region for the mentioned months. The electrical energy consumption of agricultural water wells in the region was also calculated for the desired periods of the year. Energy demand and energy supply were matched. Data analysis was performed using SPSS 18.0.0, MATLAB 7.13.0.564 and WIDOGRAPHER 3.0.2. The results show that in Broujerd, to exploit the wind energy at all times of the year, it is necessary to have at least 39 turbines of 2300 kW with 99 meters tower. If the desired turbines are used, there will be extra energy and also, agriculture will be continued towards sustainable development

Uncovering a copper(II) Alkynyl Complex in C−C Bond Forming Reactions

Copper(II) alkynyl species are proposed as key intermediates in numerous Cu−catalysed C−C coupling reactions. Supported by a β−diketiminate ligand, the three coordinate copper(II) alkynyl [CuII]−C≡CAr (Ar = 2,6−Cl2C6H3) forms upon reaction of the alkyne H−C≡CAr with the copper(II) tert−butoxide complex [CuII]−OtBu. In solution, this [CuII]−C≡CAr species cleanly transforms the to the Glaser coupling product ArC≡C−C≡CAr and [CuI](solvent). Addition of nucleophiles R′C≡CLi (R′ = aryl, silyl) and Ph–Li to [CuII]−C≡CAr affords the corresponding Csp−Csp and Csp−Csp2coupled products RC≡C−C≡CAr and Ph–C≡CAr with concomitant generation of [CuI](solvent) and {[CuI]−C≡CAr}−. Supported by DFT calculations, redox disproportionation forms [CuIII](C≡CAr)(R) species that reductively eliminate R−C≡CAr products. [CuII]−C≡CAr also captures the trityl radical Ph3C• to give Ph3C−C≡CAr. Radical capture represents the key Csp−Csp3 bond forming step in the copper catalysed C-H functionalization of benzylic substrates R−H with alkynes H−C≡CR′ (R′ = (hetero)aryl, silyl) that provide Csp−Csp3 coupled products R−C≡CR via radical relay with tBuOOtBu as oxidant.</p

Copper(II) Ketimides in sp3 C-H Amination

Commercialy available benzphenone imine (HN=CPh2) reacts with b-diketiminato copper(II) tert-butoxide complexes [CuII]-OtBu to form isolable copper(II) ketimides [CuII]-N=CPh2. Structural characterization of the three coordinate copper(II) ketimide [Me3NN]Cu-N=CPh2 reveals a short Cu-Nketimide distance (1.700(2) Å) with a nearly linear Cu-N-C linkage (178.9(2)°). Copper(II) ketimides [CuII]-N=CPh2 readily capture alkyl radicals R• (PhCH(•)Me and Cy•) to form the corresponding R-N=CPh2 products that competes with N-N coupling of copper(II) ketimides [CuII]-N=CPh2 to form the azine Ph2C=N-N=CPh2. Copper(II) ketimides [CuII]-N=CAr2 serve as intermediates in catalytic sp3 C-H amination of substrates R-H with ketimines HN=CAr2 and tBuOOtBu as oxidant to form N-alkyl ketimines R-N=CAr2. This protocol enables the use of unactivated sp3 C-H bonds to give R-N=CAr2 products easily converted to primary amines R-NH2 via simple acidic deprotection.</p

Radical Capture at Ni(II) Complexes: C-C, C-N, and C-O Bond Formation

The dinuclear b-diketiminato NiIItert-butoxide {[Me3NN]Ni}2(μ-OtBu)2 (2), synthesized from [Me3NN]Ni(2,4-lutidine) (1) and di-tert-butylperoxide, is a versatile precursor for the synthesis of a series of NiIIcomplexes [Me3NN]Ni-FG to illustrate C-C, C-N, and C-O bond formation at NiII via radicals. {[Me3NN]Ni}2(μ-OtBu)2 reacts with nitromethane, alkyl and aryl amines, acetophenone, benzamide, ammonia and phenols to deliver corresponding mono- or dinuclear [Me3NN]Ni-FG species (FG = O2NCH2, R-NH, ArNH, PhC(O)NH, PhC(O)CH2, NH2and OAr). Many of these NiII complexes are capable of capturing the benzylic radical PhCH(•)CH3 to deliver corresponding PhCH(FG)CH3 products featuring C-C, C-N or C-O bonds. DFT studies shed light on the mechanism of these transformations and suggest two competing pathways that depend on the nature of the functional groups. These radical capture reactions at [NiII]-FG complexes outline key C-C, C-N, and C-O bond forming steps and suggest new families of nickel radical relay catalysts.</p

Lewis Acid Coordination Redirects S-Nitrosothiol Reduction

S-Nitrosothiols (RSNOs) serve as air-stable reservoirs for nitric oxide in biology and are responsible for a myriad of physiological responses. While copper enzymes promote NO release from RSNOs by serving as Lewis acids capable of intramolecular electron-transfer, redox innocent Lewis acids separate these two functions to reveal the effect of coordination on structure and reactivity. The synthetic Lewis acid B(C6F5)3 coordinates to the RSNO oxygen atom in adducts RSNO-B(C6F5)3, leading to profound changes in the RSNO electronic structure and reactivity. Although RSNOs possess relatively negative reduction potentials (-1.0 to -1.1 vs. NHE), B(C6F5)3 coordination increases their reduction potential by over 1 V into the physiologically accessible +0.1 V vs. NHE. Outer-sphere chemical reduction results in formation of the Lewis acid stabilized hyponitrite dianion trans-[LA–O–N=N–O–LA]2– (LA = B(C6F5)3) that releases N2O upon acidification. Mechanistic and computational studies support initial reduction to the [RSNO-B(C6F5)3]•/- radical-anion susceptible to N-N coupling prior to loss of RSSR