A large amount of GRAS (generally recognized as safe) salts and concentrations were evaluated in in vitro tests (inhibition of mycelial growth on PDA dishes) against Lasiodiplodia theobromae, the ...causal agent of citrus Diplodia stem-end rot. Ammonium carbonate (AC, 0.2%), potassium sorbate (PS, 2.0%), potassium carbonate (PC, 0.2%), sodium methylparaben (SMP, 0.1%), sodium ethylparaben (SEP, 0.1%), sodium benzoate (SB, 2.0%), and potassium silicate (PSi, 2.0%) were selected as the most effective. Disease control ability of edible composite coatings formulated with hydroxypropyl methylcellulose (HPMC), beeswax (BW), and these selected antifungal GRAS salts was assessed in in vivo experiments with ‘Ortanique’ mandarins and ‘Barnfield’ oranges artificially inoculated with L. theobromae. Coatings containing 2% PS, 0.1% SEP, or 2% SB were the most effective reducing disease severity (up to 50% reduction) and were also applied to non-inoculated and cold-stored ‘Barnfield’ oranges to determine their effect on postharvest fruit quality. After periods of 21 and 42 d at 5 °C followed by 7 d of shelf life at 20 °C, coatings containing SEP and SB significantly reduced weight loss and did not adversely affect the physicochemical quality attributes (firmness, soluble solid content, titratable acidity, and ethanol and acetaldehyde content) and sensory flavor with respect to uncoated control fruit. Although the internal gas concentration (CO2 level) of coated fruit increased, the coatings did not induce off-flavors.
•GRAS salts effectively inhibited mycelial growth of Lasiodiplodia theobromae.•HPMC-BW coatings containing GRAS salts reduced severity of citrus Diplodia stem-end rot.•Quality of coated and cold-stored oranges was not adversely affected.
Structural variants of the (iso)‐Nazarov and aza‐(iso)Nazarov electrocyclic reactions, including monofunctional and difunctional pentadienyl cations with permutations of the heteroatom‐containing ...functional groups have been computationally studied at the ωB97XD/Def2TZVPP(SMD, THF)//ωB97XD/Def2TZVP level of theory. The relative location of two heteroatoms at either odd‐ or even‐numbered positions of the conjugated pentadienyl cation, including the Piancatelli and iso‐Piancatelli reactions and their variants, determines the feasibility of their rearrangement. In particular 4πe–‐electrocyclic reactions of formal enamines/protonated ketones are more favorable than those of the alternative enols/iminium ions. Both the classical aza‐Piancatelli and the aza‐iso‐Piancatelli electrocyclizations are highly favored. The key electrocyclic aza‐iso‐Piancatelli and aza‐Piancatelli steps of the few experimental systems successfully reported show activation energies that are in agreement with those of the simple model systems. On line with the computational predictions, the stabilization of the intermediates are key to ensure the success of these concerted electrocyclizations due to the positional location of the two heteroatoms and other factors (such as the release of strain of reacting allenes).
Computations on (iso)‐Nazarov and aza‐(iso)Nazarov as well as Piancatelli and iso‐Piancatelli electrocyclic reactions, including the few systems successfully reported to undergo the process, have confirmed the key role played by the heteroatoms when located at either odd‐ or even‐numbered positions of the conjugated enols, enamines, protonated ketones and iminium ions reaction intermediates.
In this study, the influence of abrasives (size and morphology) and graphite on the processing and properties of friction materials were investigated. Friction materials based on bronze matrix, ...graphite as solid lubricant and different abrasives (silica, mullite and zircon) were prepared following two routes. On the one hand, following the traditional P/M technology (pressing-sintering) and on the other hand, using an alternative P/M route, which consists on sintering a powder blend free deposited in a mold and subsequently cold pressing. Sinterability, microstructure and physical-mechanical properties of the processed friction materials have been studied. Tribological and wear tests were carried out on a pin-on-disc system at different loads and sliding speeds using samples of 20 mm in diameter. Results show that the influence of abrasives size is especially relevant in the alternative P/M route, where materials including fine abrasives present unsuitable properties. Graphite also plays an important role on tribological behavior, in this work it has been found that friction materials with 4 wt.% graphite have better tribological properties than those with 2 wt.% graphite, despite having lower density and mechanical resistance.
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•The melting behavior of dark-chocolates was independent of its formulation and intrinsic processing.•The chocolates exhibited two glass-transition temperatures (Tg) related to ...unstable polymorphic forms of triacylglycerides.•The chemometric analysis of volatiles discriminated against the dark-chocolates concerning the cocoa origin and genotype from Latin America.
There is a growing interest in the identification of chemometric markers that allow the distinction and authentication of dark-chocolates according to their cocoa geographical origin and/or genotype. However, samples derived from Latin American cocoa, including specimens from North and South America, have not been studied in this context. An exploration of the melting behavior, fat composition, bioactive content, and volatile profile of commercial darkchocolates was conducted to identify possible patterns related to the genotype and/or origin of cocoa from Latin America. The melting properties were evaluated by DSC and related to fat content and fatty acids profile. Total polyphenol, anthocyanin, methylxanthine, and catechin content were analyzed. Finally, the volatile compounds were extracted and identified by HS-SPME/GC-MS and were analyzed through Principal Component Analysis (PCA) and the Hierarchical Cluster Analysis Heatmap (HCA Heatmap). The fatty acids profile showed a relationship with the melting properties of dark chocolate. The samples exhibited two glass-transition temperatures (Tg) at ≈19 °C and ≈25.5 °C, possibly related to traces of unstable polymorphic forms of monounsaturated triacylglycerides. The analysis of bioactive compounds demonstrated great variability among samples independent of the cocoa origin, genotype, and content. The PCA and HCA Heatmaps allowed discriminating against the chocolates in relation to the cocoa origin and genotype. Compounds like tetramethylpyrazine, trimethylpyrazine, benzaldehyde, and furfural could be considered as dark-chocolate aroma markers derived from Latin American cocoas (North American region). The 2-phenylethyl alcohol, 2-methylpropanoic acid, 2,3-butanediol, 2-nonanone, and limonene for derived from South America. And the 2-phenylethyl acetate, 3-methyl-butanal, and cinnamaldehyde could allow to distinguishing between regional genotypes.
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•Novel polarization strategy for monitoring hydrogen evolution with SECM.•Application of a fixed anodic polarization between free corrosion stages.•The measured tip currents correlate ...with the magnitude of prior anodic polarization.•Observations correlate with the notion of enhanced catalytic activity for H2 evolution.
The evolution of hydrogen gas from corroding magnesium arises not exclusively from the cathodic half-cell reaction due to the consumption of the electrons released by the dissolving metal, but anodized magnesium generates significant amounts of H2 gas as well. In addition, the increase of the anodic overpotential enhances the rate of hydrogen gas generation. Therefore, spatially-resolved detection of the actual sites for hydrogen evolution related to anodically-activated sites is attempted using scanning electrochemical microscopy (SECM). This work describes a new experimental procedure for SECM based on a three-step (off-on-off) anodization operation sequence that was designed to obtain new insights into the behavior of magnesium and magnesium alloys when they are subjected to anodic polarization. Results obtained with scanning electrochemical microscopy (SECM) and scanning vibrating electrode technique (SVET) experiments presented here demonstrate the catalytic properties of the magnesium-oxide film for the hydrogen-evolution reaction.
CBL missense mutations have recently been associated with juvenile myelomonocytic leukaemia (JMML), an aggressive myeloproliferative and myelodysplastic neoplasm of early childhood characterised by ...excessive macrophage/monocyte proliferation. CBL, an E3 ubiquitin ligase and a multi-adaptor protein, controls proliferative signalling networks by downregulating the growth factor receptor signalling cascades in various cell types.
CBL mutations were screened in 65 patients with JMML. A homozygous mutation of CBL was found in leukaemic cells of 4/65 (6%) patients. In all cases, copy neutral loss of heterozygosity of the 11q23 chromosomal region, encompassing the CBL locus, was demonstrated. Three of these four patients displayed additional features suggestive of an underlying developmental condition. A heterozygous germline CBL p.Y371H substitution was found in each of them and was inherited from the father in one patient. The germline mutation represents the first hit, with somatic loss of heterozygosity being the second hit positively selected in JMML cells. The three patients display a variable combination of dysmorphic features, hyperpigmented skin lesions and microcephaly that enable a 'CBL syndrome' to be tentatively delineated. Learning difficulties and postnatal growth retardation may be part of the phenotype.
A report of germline mutations of CBL in three patients with JMML is presented here, confirming the existence of an unreported inheritable condition associated with a predisposition to JMML.
This study sought to examine the impact of the presence of two co-dominant (ovulatory) follicles at the time of artificial insemination (AI) on the ovulatory response to GnRH given in a fixed-time AI ...protocol. The study population comprised 622 lactating dairy cows: 306 (49.2%) with a single follicle, 198 (31.8%) with two bilateral follicles (one follicle per ovary) and 118 (19%) with two unilateral follicles (same ovary). Based on odds ratios, cows with two bilateral or unilateral follicles were less likely (by factors of 0.09 and 0.11, respectively) to undergo ovulation failure compared with cows with one follicle (P = 0.01 and P = 0.02, respectively); the likelihood of ovulation failure decreased 0.75 times with every one-mm increase in follicle diameter for cows with a single follicle, whereas individual follicle diameter was not related to ovulation failure in cows with two bilateral follicles (P = 0.001). The likelihood of double ovulation decreased 0.7 times with every one-mm diameter difference between the larger and smaller follicle for all cows with two follicles (P = 0.001), whereas cows with two unilateral follicles showed a higher (P < 0.05) double ovulation rate than cows with two bilateral follicles. In 116 (58.6%) of the cows with two bilateral follicles, only the larger follicle ovulated in 59.5% cows, whereas only the smaller one ovulated in the remaining 40.5% cows. In these cows, a one-mm size difference between the larger and the smaller follicle gave rise to a 1.12-fold increase in the ovulation failure rate for the larger follicles (P = 0.0001). Cows with two bilateral follicles were more likely (by a factor of 1.5) to conceive than cows with one follicle (P = 0.001). Significant right-left differences were not found in cows with two bilateral follicles, whereas the right ovary was more active than the left in the remaining cows. Our results indicate that cows with two co-dominant follicles at AI show different ovulation patterns to those with one dominant follicle. A higher rate of ovulation failure was observed among cows with one follicle than cows with two follicles, whereas the conception rate was higher for cows with two bilateral follicles than for the remaining cows. In cows with two follicles, double ovulations along with ovulation of the smaller follicle were related to the least size difference between the larger and smaller follicle.
•The likelihood of ovulation increased with increasing follicle diameter in cows with one follicle.•Individual follicle size was not related to ovulation failure in cows with one ovulatory follicle in each ovary.•Cows with two unilateral follicles showed a greater likelihood of double ovulation than cows with two bilateral follicles.•The conception rate was higher for cows with two bilateral follicles compared with two unilateral or a single follicle.
Clinicians reported an increasing trend of rapid progression (RP) (AIDS within 3years of infection) in Cuba.
Recently infected patients were prospectively sampled, 52 RP at AIDS diagnosis (AIDS-RP) ...and 21 without AIDS in the same time frame (non-AIDS). 22 patients were sampled at AIDS diagnosis (chronic-AIDS) retrospectively assessed as >3years infected. Clinical, demographic, virological, epidemiological and immunological data were collected. Pol and env sequences were used for subtyping, transmission cluster analysis, and prediction of resistance, co-receptor use and evolutionary fitness. Host, immunological and viral predictors of RP were explored through data mining.
Subtyping revealed 26 subtype B strains, 6 C, 6 CRF18_cpx, 9 CRF19_cpx, 29 BG-recombinants and other subtypes/URFs. All patients infected with CRF19 belonged to the AIDS-RP group. Data mining identified CRF19, oral candidiasis and RANTES levels as the strongest predictors of AIDS-RP. CRF19 was more frequently predicted to use the CXCR4 co-receptor, had higher fitness scores in the protease region, and patients had higher viral load at diagnosis.
CRF19 is a recombinant of subtype D (C-part of Gag, PR, RT and nef), subtype A (N-part of Gag, Integrase, Env) and subtype G (Vif, Vpr, Vpu and C-part of Env). Since subtypes D and A have been associated with respectively faster and slower disease progression, our findings might indicate a fit PR driving high viral load, which in combination with co-infections may boost RANTES levels and thus CXCR4 use, potentially explaining the fast progression. We propose that CRF19 is evolutionary very fit and causing rapid progression to AIDS in many newly infected patients in Cuba.
•We propose that CRF19 is evolutionary very fit, causing rapid progression to AIDS in many newly infected patients in Cuba.•CRF19 is a recombinant of subtype D, subtype A and subtype G, with a subtype D protease estimated to be particularly fit.•A fit protease with high viral load and co-infections, may boost RANTES levels and thus CXCR4 use, hence fast progression.
STUDY QUESTION
Does fibronectin (Fn) stimulate the sperm capacitation process in humans?
SUMMARY ANSWER
Fibronectin stimulates human sperm capacitation.
WHAT IS KNOWN ALREADY
Capacitation is a ...process that occurs in the oviduct. It has been suggested that some molecules present in the oviductal fluid and cells as well as proteins present in the cumulus oophorus could be involved in the modulation of sperm function and their acquisition of fertilizing capacity. Fibronectin is a glycoprotein that is present in the fluid and the oviduct epithelium, and its receptor (alpha 5 beta 1 integrin) is present in human sperm. When alpha 5 beta 1 (α5β1) integrin binds to fibronectin, intracellular signals similar to the process of sperm capacitation are activated.
STUDY DESIGN, SIZE, DURATION
Human sperm were selected via a percoll gradient and were then incubated in non-capacitated medium (NCM) or reconstituted capacitated medium (RCM), in the presence or absence of fibronectin for different time periods. A total of 39 donors were used during the study, which lasted 3 years.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Freshly ejaculated sperm from healthy volunteers were obtained by masturbation. All semen samples were normal according to the World Health Organization parameters. Six approaches were used to determine the effects of fibronectin on sperm capacitation: chlortetracycline (CTC) assay, heterologous co-culture of human sperm with bovine oviductal epithelial cells (BOEC), measurement of cyclic (c) AMP levels, activity of protein kinase A (PKA), phosphorylation of proteins in tyrosine (Tyr) residues, and induction of acrosome reaction with progesterone.
MAIN RESULTS AND THE ROLE OF CHANCE
When sperm were incubated in RCM in the presence of Fn, we observed differences with respect to sperm incubated in RCM without Fn (control): (i) a 10% increase in the percentage of sperm with the B pattern (capacitated sperm) of CTC fluorescence from the beginning of capacitation (P < 0.001); (ii) an effect on both the concentration of cAMP (P < 0.05) and PKA activity (P < 0.05) during early capacitation; (iii) an increase in the degree of phosphorylation of proteins on tyrosine residues after 60 min of capacitation (P < 0.01); (iv) an increase in the percentage of acrosome-reacted sperm in response to progesterone (P < 0.05); and (v) a decrease in the percentage of sperm attached to BOEC (P < 0.05). Moreover, we noted that the effect of Fn was specific and mediated by alpha 5 beta 1 integrin (P < 0.001). Fn by itself had no effect on sperm capacitation.
LIMITATIONS, REASONS FOR CAUTION
This study was carried out with sperm from young adult men. Men with abnormal semen samples were excluded. The results cannot be directly extrapolated to other mammalian species.
WIDER IMPLICATIONS OF THE FINDINGS
Currently, male subfertility has become a huge public health problem, which makes it imperative to develop new treatments. This is a novel discovery that extends our current knowledge concerning normal and pathological sperm physiology as well as events that regulate the process of fertilization.
STUDY FUNDING/COMPETING INTEREST(S)
This study was supported by grants from FONDECYT (1130341, E.S.D. and 1120056, P.M.) and FONCYT (PIP 2011-0496, S.P.-M). The authors have no conflicts of interest.
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