Complex acylation of Angiotensin II by N-Hydroxysulfosuccinimide linked biotin reagents

N-Hydroxysulfosuccinimide-linked biotins (sulfoNHS-biotins) are water soluble biotin tags commonly used to conjugate a biotin moiety to proteins by rapid N-acylation of primary amines. Unexpected O-acylation by sulfoNHSbiotin on tyrosine of Angiotensin II (Ag-II) and an acylation on third site unable to characterize were identified by LC-MS in addition to the expected N-acylation on the N-terminal of Ag-II. The N-acylation only undergoes incomplete hydrolysis in 0.1% formic acid not at pH 7.2 and 8.0, while two unexpected acylation hydrolyze at both conditions, but their hydrolysis in 0.1% formic acid was much more rapid. Dithiothreitol treatment selectively catalyzed hydrolysis of both of the unexpected acylation but not the N-acylation of Ag-II. The maximum yield of O-acylation of the AgII tyrosine was 99% at pH 7.2 and 95% at pH 8.0 as compared N-acylation of lysine when reacted with excess sulfoNHS-biotin with these yields of 94% at pH 7.2 and 96% at pH 8.0. Acylation of the third uncharacterized site of Ag-II showed maximum yield of approximately 17% at pH 7.2, but higher yield (≥ 47%) at pH 8.0 within 30 min. The unexpected O-acylation of the Ag-II tyrosine occurred within 1 min at either pH 7.2 or pH 8.0, as rapidly as the N-acylation, while the other unexpected acylation required more time to complete at pH 8.0

Dynamics of consumer demand for proprietary software in the presence of open source software

Over the last two decades, the software industry has witnessed the outstanding growth and adoption of the Open Source Software (OSS). Industry analysts claim that the market share of Proprietary Software (PS) has been shrinking because of the competitive pressure from OSS. Nevertheless, many PS vendors, such as IBM, Oracle, etc., are surprisingly active participants in OSS development and community, which could be particularly instrumental in helping their PS sales. Therefore, it remains largely unclear as to the net impact of OSS entry on the demand for PS. The resolution to this central tension in the extant literature has immense theoretical implications for the research on competitive rivalry as well as managerial implications for PS vendors regarding their product and pricing strategies. To …postprin

Interpretation of the Flavor Dependence of Nucleon Form Factors in a Generalized Parton Distribution Model

We give an interpretation of the $u$ and $d$ quarks contributions to the nucleon electromagnetic form factors for values of the four-momentum transfer in the multi-GeV region where flavor separated data have been recently made available. The data show, in particular, a suppression of $d$ quarks with respect to $u$ quarks at large momentum transfer. %and constant ratios of the flavor dependent Pauli to Dirac form factors ratios. This trend can be explained using a reggeized diquark model calculation of generalized parton distributions, thus providing a correlation between momentum and coordinate spaces, both of which are necessary in order to interpret the partonic substructure of the form factors. We extend our discussion to the second moments of generalized parton distributions which are believed to contribute to partonic angular momentum.Comment: 22 pages, 19 figures; results and figures added and changed, tables added, formulae added, major rewriting of tex

A selective turn-on fluorescent chemosensor 1,1-diaminoazine for azinphos-methyl

Financiaciado para publicación en acceso aberto: Universidade de Vigo/CISUGDetection of organophosphorus pesticides (OPPs) is an important challenge in environmental chemistry, because their exposure to humans can cause severe health problems. In the current study, organic nanoparticles of (E)-(4-chlorophenyl)-1,1-diamino-2,3-diazabutadiene were developed using eco-friendly approach which was found to be in the range of 15–20 nm. These synthesized species exhibited both U.V. Visible and “turn-on” fluorescence responses in aqueous media for the selective detection of the extremely hazardous pesticide azinphos-methyl. These organic nanoparticles also exhibit a good linear relationship in the range of 1–100 μM and the limit of detection (LOD) is 7.4 µM. The selective fluorescence response was also observed in RO water, tap water and orange juice. The FT-IR and DFT studies helped in identifying the specific H-bonding interactions responsible for the selective detection of Azinphos-methylDepartment of Science and Technology, New-Delhi, India | Ref. SP/YO/2021/231

Do Multinational enterprises push up wages of domestic firms in the Italian Manufacturing sector?

This paper analyzes the effects of foreign direct investment on wages paid by domestic firms in the Italian manufacturing sector over the period 2002–2007. In particular, the authors investigate the im-pact of multinational enterprises on wages paid by local firms which operate in the same industry, known and horizontal wage spillovers, or have linkages with multinational enterprises in both downstream and upstream industries, known as vertical wage spillovers. By using a large panel dataset, consisting of 551,000 observations, the authors find evidence of wage spillovers only at inter-industry level and, more specifically, for those firms who supply their goods to multinational enterprises, described as backward wage spillovers. Moreover, findings suggest that the wage spillover effect is strongly affected by the technological gap between local and foreign firms: only workers employed in domestic firms with a low-medium technological absorptive capacity seem to benefit from the presence of multinational enterprises in terms of higher wages

Microstructural characterization of AISI 431 martensitic stainless steel laser-deposited coatings

High cooling rates during laser cladding of stainless steels may alter the microstructure and phase constitution of the claddings and consequently change their functional properties. In this research, solidification structures and solid state phase transformation products in single and multi layer AISI 431 martensitic stainless steel coatings deposited by laser cladding at different processing speeds are investigated by optical microscopy, Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), orientation imaging microscopy (OIM), ternary phase diagram, Schaeffler and TTT diagrams. The results of this study show how partitionless solidification and higher solidification rates alter the microstructure and phase constitution of martensitic stainless steel laser deposited coatings. In addition, it is shown that while different cladding speeds have no effect on austenite–martensite orientation relationship in the coatings, increasing the cladding speed has resulted in a reduction of hardness in deposited coatings which is in contrast to the common idea about obtaining higher hardness values at higher cladding speeds.

Caffeine ingestion compromises thermoregulation and does not improve cycling time to exhaustion in the heat among males

Purpose Caffeine is a commonly used ergogenic aid for endurance events; however, its efficacy and safety have been questioned in hot environmental conditions. The aim of this study was to investigate the effects of acute caffeine supplementation on cycling time to exhaustion and thermoregulation in the heat. Methods In a double-blind, randomised, cross-over trial, 12 healthy caffeine-habituated and unacclimatised males cycled to exhaustion in the heat (35 \ub0C, 40% RH) at an intensity associated with the thermoneutral gas exchange threshold, on two separate occasions, 60 min after ingesting caffeine (5 mg/kg) or placebo (5 mg/kg). Results There was no effect of caffeine supplementation on cycling time to exhaustion (caffeine; 28.5 \ub1 8.3 min vs. placebo; 29.9 \ub1 8.8 min, P = 0.251). Caffeine increased pulmonary oxygen uptake by 7.4% (P = 0.003), heat production by 7.9% (P = 0.004), whole-body sweat rate by 21% (P = 0.008), evaporative heat transfer by 16.5% (P = 0.006) and decreased estimated skin blood flow by 14.1% (P < 0.001) compared to placebo. Core temperature was higher by 0.6% (P = 0.013) but thermal comfort decreased by -18.3% (P = 0.040), in the caffeine condition, with no changes in rate of perceived exertion (P > 0.05). Conclusion The greater heat production and storage, as indicated by a sustained increase in core temperature, corroborate previous research showing a thermogenic effect of caffeine ingestion. When exercising at the pre-determined gas exchange threshold in the heat, 5 mg/kg of caffeine did not provide a performance benefit and increased the thermal strain of participants

Modulation of frustration in folding by sequence permutation

Folding of globular proteins can be envisioned as the contraction of a random coil unfolded state toward the native state on an energy surface rough with local minima trapping frustrated species. These substructures impede productive folding and can serve as nucleation sites for aggregation reactions. However, little is known about the relationship between frustration and its underlying sequence determinants. Chemotaxis response regulator Y (CheY), a 129-amino acid bacterial protein, has been shown previously to populate an off-pathway kinetic trap in the microsecond time range. The frustration has been ascribed to premature docking of the N- and C-terminal subdomains or, alternatively, to the formation of an unproductive local-in-sequence cluster of branched aliphatic side chains, isoleucine, leucine, and valine (ILV). The roles of the subdomains and ILV clusters in frustration were tested by altering the sequence connectivity using circular permutations. Surprisingly, the stability and buried surface area of the intermediate could be increased or decreased depending on the location of the termini. Comparison with the results of small-angle X-ray-scattering experiments and simulations points to the accelerated formation of a more compact, on-pathway species for the more stable intermediate. The effect of chain connectivity in modulating the structures and stabilities of the early kinetic traps in CheY is better understood in terms of the ILV cluster model. However, the subdomain model captures the requirement for an intact N-terminal domain to access the native conformation. Chain entropy and aliphatic-rich sequences play crucial roles in biasing the early events leading to frustration in the folding of CheY