We show that formyl benzeno boronic acids (2FBBA) selectively react with
-terminal cysteines to yield a boronated thiazolidine featuring a B-N bond. The reaction exhibits a very rapid constant rate ...(2.38 ± 0.23 × 10
M
s
) under mild aqueous conditions (pH 7.4, 23 °C) and tolerates different amino acids at the position adjacent to the
-cysteine. DFT calculations highlighted the diastereoselective nature of this ligation reaction and support the involvement of the proximal boronic acid in the activation of the imine functionality and the stabilisation of the boronated thiazolidine through a chelate effect. The 2FBBA reagent allowed the effective functionalisation of model peptides (C-ovalbumin and a laminin fragment) and the boronated thiazolidine construct was shown to be stable over time, though the reaction was reversible in the presence of benzyl hydroxylamine. The reaction proved to be highly chemoselective, and 2FBBA was used to functionalize the
-terminal cysteine of calcitonin in the presence of a potentially competing in-chain thiol group. This exquisite selectivity profile enabled the dual functionalisation of calcitonin and the interactive orthogonal modification of this peptide when 2FBBA was combined with conventional maleimide chemistry. These results highlight the potential of this methodology to construct complex and well-defined bioconjugates.
The enzymatic alcoholysis of soybean oil with methanol and ethanol was investigated using a commercial, immobilized lipase (Lipozyme RMIM). The effect of alcohol (methanol or ethanol), enzyme ...concentration, molar ratio of alcohol to soybean oil, solvent, and temperature on biodiesel production was determined. The best conditions were obtained in a solvent-free system with ethanol/oil molar ratio of 3.0, temperature of 50 degrees C, and enzyme concentration of 7.0% (w/w). Three-step batch ethanolysis was most effective for the production of biodiesel. Ethyl esters yield was about 60% after 4 h of reaction.
Specific folate receptors are abundantly overexpressed in chronically activated macrophages and in most cancer cells. Directed folate receptor targeting using liposomes is usually achieved using ...folate linked to a phospholipid or cholesterol anchor. This link is formed using a large spacer like polyethylene glycol. Here, we report an innovative strategy for targeted liposome delivery that uses a hydrophobic fragment of surfactant protein D linked to folate. Our proposed spacer is a small 4 amino acid residue linker. The peptide conjugate inserts deeply into the lipid bilayer without affecting liposomal integrity, with high stability and specificity. To compare the drug delivery potential of both liposomal targeting systems, we encapsulated the nuclear dye Hoechst 34580. The eventual increase in blue fluorescence would only be detectable upon liposome disruption, leading to specific binding of this dye to DNA. Our delivery system was proven to be more efficient (2-fold) in Caco-2 cells than classic systems where the folate moiety is linked to liposomes by polyethylene glycol.
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•Printed circuit boards (PCB) of mobile phones have large amounts of metals with high economic value such as gold and silver.•Dissolution of gold was done with a cyanide-based reagent ...and silver with nitric acid.•Leaching of PCB with Na2S2O3 and (NH4)2S2O3 to examine the feasibility of using these reagents was done.
Electronic waste has been increasing proportionally with the technology. So, nowadays, it is necessary to consider the useful life, recycling, and final disposal of these equipment. Metals, such as Au, Ag, Cu, Sn and Ni can be found in the printed circuit boards (PCB). According to this, the aims of this work is to characterize the PCBs of mobile phones with aqua regia; obtaining “reference” values of leaching, to gold and silver, with cyanide and nitric acid, respectively; and study the process of leaching of these metals in alternative leaching with sodium thiosulfate and ammonium thiosulfate. The metals were characterized by digesting the sample with aqua regia for 1 and 2h at 60°C and 80°C. The leaching of Au with a commercial reagent (cyanide) and the Ag with HNO3were made. The leaching of Au and Ag with alternative reagents: Na2S2O3, and (NH4)2S2O3 in 0.1M concentration with the addition of CuSO4, NH4OH, and H2O2, was also studied. The results show that the digestion with aqua regia was efficient to characterize the metals present in the PCBs of mobile phones. However, the best method to solubilize silver was by digesting the sample with nitric acid. The leaching process using sodium thiosulfate was more efficient when an additional concentration of 0.015 and 0.030M of the CuSO4 was added.
Background: Although the survival rate has considerably improved, many patients with systemic lupus erythematosus (SLE) develop irreversible organ damage. Objectives: The objectives of this paper are ...to characterize cumulative damage in SLE patients and identify variables associated with its presence and severity. Methods: A cross-sectional analysis of SLE patients from the Portuguese Lupus register Reuma.pt/SLE in whom damage assessment using the SLICC/ACR-Disability Index (SDI) was available was performed. Predictor factors for damage, defined as SDI ≥ 1, were determined by logistic regression analyses. A sub-analysis of patients with severe damage (SDI ≥ 3) was also performed. Results: In total, 976 patients were included. SDI was ≥1 in 365 patients, of whom 89 had severe damage. Musculoskeletal (24.4%), neuropsychiatric (24.1%) and ocular (17.2%) domains were the most commonly affected. Older age, longer disease duration, renal involvement, presence of antiphospholipid antibodies and current therapy with steroids were independently associated with SDI ≥ 1. The subpopulation with severe damage had, in addition, a greater interval between the first manifestation attributable to SLE and the clinical diagnosis as well as and more frequently early retirement due to SLE. Conclusions: This large lupus cohort confirmed that demographic and clinical characteristics as well as medication are independently associated with damage. Additionally, premature retirement occurs more often in patients with SDI ≥ 3. Diagnosis delay might contribute to damage accrual.
The Tabapuã breed is a beef cattle Brazilian breed known for its sexual precocity and desirable characteristics for tropical conditions. However, this is a newly formed breed and few studies have ...been conducted regarding genetic parameters and genetic trends for its reproductive traits. The objective of the present study was to estimate the genetic parameters, genetic trends, and relative selection efficiency for weaning weight adjusted to 210 d of age (W210), age at first calving (AFC), average calving interval (ACI), first calving interval (CI1), and accumulated productivity (ACP) among Tabapuã beef cattle. Pedigree data on 15,241 Tabapuã animals born between 1958 and 2011 and phenotype records from 7,340 cows born between 1970 and 2011 were supplied by the National Association of Breeders and Researchers (Associação Nacional de Criadores e Pesquisadores). Analysis through the least squares method assisted in defining the fixed effects that were considered within the models. The estimates for the genetic parameters were obtained through the REML, using a multitrait animal model. The likelihood ratio test applied for W210 was significant ( < 0.05) for the inclusion of maternal additive genetic and permanent environmental effects in the model. Genetic trends were calculated through linear regression of the EBV of the animals, according to the year of birth. The heritability estimates obtained ranged from 0.04 ± 0.03 for CI1 to 0.25 ± 0.05 for W210. The genetic correlations ranged from 0.004 ± 0.19 for W210-AFC and 0.93 ± 0.12 for ACI-CI1. The genetic trend was significant ( < 0.05) and favorable for CI1 and the maternal genetic effect of W210 and was significant ( < 0.05) and unfavorable for AFC, ACI, and ACP. The ACP could be used in the selection index to assist the breeding goal of improved productive and reproductive performance. The genetic trends indicated small and unfavorable genetic changes for AFC, ACI, and ACP in light of the recent implementation of a genetic breeding program for this breed.
Quaternized vinyl‐ and alkynyl‐pyridine reagents were shown to react in an ultrafast and selective manner with several cysteine‐tagged proteins at near‐stoichiometric quantities. We have demonstrated ...that this method can effectively create a homogenous antibody–drug conjugate that features a precise drug‐to‐antibody ratio of 2, which was stable in human plasma and retained its specificity towards Her2+ cells. Finally, the developed warhead introduces a +1 charge to the overall net charge of the protein, which enabled us to show that the electrophoretic mobility of the protein may be tuned through the simple attachment of a quaternized vinyl pyridinium reagent at the cysteine residues. We anticipate the generalized use of quaternized vinyl‐ and alkynyl‐pyridine reagents not only for bioconjugation, but also as warheads for covalent inhibition and as tools to profile cysteine reactivity.
Quaternize to click: The computation‐inspired discovery of quaternization of the nitrogen of vinyl and alkynyl pyridine reagents to enable selective and ultrafast modification of cysteine at near‐stoichiometric quantities is presented. With this strategy, stable and defined antibody–drug conjugates can be prepared. Furthermore, the electrophoretic mobility of the protein may be modulated through simple introduction of a +1 charge to its overall net charge, as shown using microfluidics.
This paper describes some R&D activities conducted in support of the design and safe operation of a high-power liquid Pb-Bi target within the LIEBE (Liquid Eutectic Lead Bismuth Loop Target for ...EURISOL) project. The target material is lead bismuth eutectic (LBE) which also acts as a primary coolant. As a consequence of interaction of the highly pulsed 1.4-GeV protons at ISOLDE with the target, heat powers of the order of 2GW would be instantaneously deposited in the target during a bunch. Considerable R&D effort is thus required to demonstrate its continued coolability and structural integrity. This paper mainly reports on the conjugate flow (CFD) and heat deposition (Monte Carlo) calculations, not accounting for Fluid–Structure Interactions.
ABSTRACTThis article presents a novel approach to classifying archaeological artefacts using machine learning, specifically deep learning, rather than relying on traditional, time-consuming ...human-based methods. By employing Convolutional Neural Networks (CNNs), this approach aims to expedite and enhance the identification process, making it more accessible to a wider audience. The study focuses on two types of artefacts- Roman Lusitanian amphorae (2nd-5th centuries) and Portuguese faience (16th-18th centuries)- chosen for their diversity. While Lusitanian amphorae lack decoration, Portuguese faience poses challenges with subtle colour variations. The study demonstrates the potential of this approach to overcome these hurdles. The paper outlines the methodology, dataset creation, and model training, emphasizing the importance of extensive data and computational resources. The ultimate objective of this research is to develop a mobile application that utilizes image classification techniques to accurately classify ceramic sherds and bring about a significant transformation in archaeological classification.
First laser ions at the CERN-MEDICIS facility Gadelshin, Vadim Maratovich; Wilkins, Shane; Fedosseev, Valentin Nikolaevich ...
Hyperfine interactions,
2020, Letnik:
241, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CERN-MEDICIS facility aims to produce emerging medical radionuclides for the theranostics approach in nuclear medicine with mass separation of ion beams. To enhance the radioisotope yield and ...purity of collected samples, the resonance ionization laser ion source MELISSA was constructed, and provided the first laser ions at the facility in 2019. Several operational tests were accomplished to investigate its performance in preparation for the upcoming production of terbium radioisotopes, which are of particular interest for medical applications.
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