Determination of toxicological relevant arsenic species in urine by hydride generation microwave-induced plasma optical emission spectrometry.

An analytical method for the determination of toxicological relevant species of arsenic in urine was developed and validated using hydride generation microwave-induced emission spectrometry (HG-MP-AES). This strategy can be used as an alternative to HG-HPLC-ICP-MS considered as a reference technique for arsenic speciation. This procedure is notably less expensive than other techniques and sample preparation and requires only a few steps.•Hydride generation with MP-AES detection has proven to be an effective technique for measuring arsenic metabolites in urine, which is relevant for occupational monitoring and health risk assessment purposes.•This method offers simplicity and cost-effectiveness, serving as an alternative to classical analytical procedures typically used for arsenic analysis in urine.•The methodology has been successfully applied for the purpose of workers' health surveillance.

Clinical risk prediction model and external validation of positive surgical margin in laparoscopic radical prostatectomy based on MRI lesion location.

OBJECTIVE: To clarify the composition of lesions in different magnetic resonance imaging (MRI) partitions of positive surgical margins (PSM) after laparoscopic radical prostatectomy, explore the influence of lesion location on PSM, and construct a clinical prediction model to predict the risk of PSM. MATERIALS AND METHODS: This retrospective cohort study included 309 patients who underwent laparoscopic radical prostatectomy from 2018 to 2021 in our center was performed. 129 patients who met the same criteria from January to September 2022 were external validation cohorts. RESULTS: The incidence of PSM in transition zone (TZ) lesions was higher than that in peripheral zone (PZ) lesions. The incidence of PSM in the middle PZ was lower than that in other regions. Prostate specific antigen (PSA), clinical T-stage, the number of positive cores, international society of urological pathology (ISUP) grade (biopsy), MRI lesion location, extracapsular extension, seminal vesicle invasion (SVI), pseudo-capsule invasion (PCI), long diameter of lesions, lesion volume, lesion volume ratio, PSA density were related to PSM. MRI lesion location and PCI were independent risk factors for PSM. Least absolute shrinkage and selection operator (LASSO) regression was used to construct a clinical prediction model for PSM, including five variables: the number of positive cores, SVI, MRI lesion location, long diameter of lesions, and PSA. CONCLUSION: The positive rate of surgical margin in middle PZ was significantly lower than that in other regions, and MRI lesion location was an independent risk factor for PSM.

Geographical origin identification of mandarin fruits by analyzing fingerprint signatures based on multielemental composition.

Given rising traders and consumers concerns, the global food industry is increasingly demanding authentic and traceable products. Consequently, there is a heightened focus on verifying geographical authenticity as food quality assurance. In this work, we assessed pattern recognition approaches based on elemental predictors to discern the provenance of mandarin juices from three distinct citrus-producing zones located in the Northeast region of Argentina. A total of 202 samples originating from two cultivars were prepared through microwave-assisted acid digestion and analyzed by microwave plasma atomic emission spectroscopy (MP-AES). Later, we applied linear discriminant analysis (LDA), k-nearest neighbor (k-NN), support vector machine (SVM), and random forest (RF) to the element data obtained. SVM accomplished the best classification performance with a 95.1% success rate, for which it was selected for citrus samples authentication. The proposed method highlights the capability of mineral profiles in accurately identifying the genuine origin of mandarin juices. By implementing this model in the food supply chain, it can prevent mislabeling fraud, thereby contributing to consumer protection.

The effect of the electronic structure method and basis set on the accuracy of the electric multipoles computed with the distributed multipole analysis (DMA).

CONTEXT: An accurate description of the molecular charge density is crucial for investigating intra- and inter-molecular properties. Among the different ways of describing and analyzing it, the widely used distributed multipole analysis (DMA) is an accurate method for decomposing the molecular charge density into atom-centered electric multipoles (monopole, dipole, quadrupole, and so on) that have a direct chemical interpretation. In this work, DMA was employed to decompose the molecular charge density of six chemically distinct molecules, namely, (2R)-2-amino-3-[(S)-prop-2-enylsulfinyl] propanoic acid (AAP), 4-amine-2-nitro-1,3,5 triazole (ANTA), (RS)-Propan-2-yl methylphosphonofluoridate (SARIN), chloromethane (CLMET), and 2-aminoacetic acid (GLY) into monopole, dipole, and quadrupole values. A hypothetical variation of ANTA built by exchanging all the nitrogen atoms with phosphorus that we named 4-phosphine-2-phosphite-1,3,5-phosphorine (ANTAP) was also studied. These molecules have different chemical structures bearing distinct carbon skeletons, electronegative atoms, and electron-withdrawing/donating groups. We found that although DFT multipole values can depend considerably on the exchange-correlation functional for specific atomic sites, the associated root-mean-square errors (RMSEs) compared to benchmark MP4 mainly were about [Formula: see text] The most significant variations were for monopoles and dipoles of sites highly polarized by adjacent atoms, and to a lesser degree, for the quadrupoles. The double hybrid B2PLYP and the hybrid meta M06-2X functionals, as expected in the framework of Jacob's ladder, overall give the most accurate results among the DFT methods. The MP2 DMA multipole values have an RMSE in relation to the MP4 benchmark mainly in the range [Formula: see text], thus representing a lower computational cost to obtain results with similar good accuracy without the ambiguity of choosing a DFT functional. The deviations of the HF multipoles from the benchmark in most cases were less than 20%, in agreement with the well-known fact that non-correlated charge densities have a slight dependence on the electronic correlation. We also confirmed that DMA values have a small dependence on the size of the basis set: deviations did not exceed 5% in most cases. However, the dependence of the DMA values on the size of the basis set increases with the rank of the electric multipole. To compute accurate values of DMA multipoles of an atom bonded to very electronegative atoms, especially dipoles and quadrupoles, a large basis set including diffuse functions is necessary. Despite that, for a given polarized basis set, the choice of the basis set to compute accurate DMA multipole values is not critical. METHODS: The molecular charge densities were computed using the electronic structure methods Hartree-Fock (HF), MP2, MP4, DFT/PBE, DFT/B3LYP, DFT/B3PW91, DFT/M06-2X, and DFT/B2PLYP implemented in the Gaussian 09 package. MP4 was the benchmark method. The DMA multipoles were obtained with the GDMA program of Stone. The 6-311G + + (d,p) basis set was used for the production calculations, and the augmented correlation-consistent Dunning's hierarchy of basis sets was employed to evaluate the dependence of the DMA multipoles on the basis set size.

Should we think about green or white analytical chemistry? Case study: Accelerated sample preparation using an ultrasonic bath for the simultaneous determination of Mn and Fe in beef.

Green Analytical Chemistry (GAC) metrics include a variety of criteria, such as the regent amounts and toxicity, energy consumption, generated waste, among others. The analytical greenness metric (AGREE) and its variant for sample preparation (AGREEprep) cover different aspects that contribute to the environmental sustainability of sample preparation. White Analytical Chemistry (WAC) considers not only environmental aspects but also analytical and practical aspects with a holistic vision based on a Red-Green-Blue color model. A case study is presented to assess the green and white profile of a method based on ultrasound-assisted extraction and determination of Mn and Fe in beef using microwave-induced plasma atomic emission spectroscopy (MP AES). The method was validated and resulted simple, fast without external heating using diluted acids. It was concluded that we should think in green sample preparation with the AGREEprep tool, as well as in white holistic assessments (WAC) as both constitute complementary tools.

Two MP2CL5 Antigen Vaccines from Naegleria fowleri Stimulate the Immune Response against Meningitis in the BALB/c Model.

Naegleria fowleri is an etiological agent that generates primary amoebic meningoencephalitis; unfortunately, no effective treatment or vaccine is available. The objective of this work was to determine the immunoprotective response of two vaccine antigens, as follows: (i) the polypeptide band of 19 kDa or (ii) a predicted immunogenic peptide from the membrane protein MP2CL5 (Smp145). Both antigens were administered intranasally in mice using cholera toxin (CT) as an adjuvant. The survival rate and immune response of immunized mice with both antigens and challenged with N. fowleri trophozoites were measured in the nose-associated lymphoid tissue (NALT) and nasal passages (NPs) by flow cytometry and enzyme-linked immunosorbent assay (ELISA). We also determined the immunolocalization of both antigens in N. fowleri trophozoites by confocal microscopy. Immunization with the polypeptide band of 19 kDa alone or coadministered with CT was able to confer 80% and 100% of protection, respectively. The immunization with both antigens (alone or coadministered with CT) showed an increase in T and B lymphocytes. In addition, there was an increase in the expression of integrin α4ß1 and IgA in the nasal cavity of protected mice, and the IgA, IgG, and IgM levels were increased in serum and nasal washes. The immunolocalization of both antigens in N. fowleri trophozoites was observed in the plasma membrane, specifically in pseudopod-like structures. The MP2CL5 antigens evaluated in this work were capable of conferring protection which would lead us to consider them as potential candidates for vaccines against meningitis caused by N. fowleri.

The Combination of Synoeca-MP Antimicrobial Peptide with IDR-1018 Stimulates Proliferation, Migration, and the Expression of Pro-Regenerative Genes in Both Human Skin Cell Cultures and 3D Skin Equivalents.

In skin lesions, the development of microbial infection affects the healing process, increasing morbidity and mortality rates in patients with severe burns, diabetic foot, and other types of skin injuries. Synoeca-MP is an antimicrobial peptide (AMP) that exhibits activity against several bacteria of clinical importance, but its cytotoxicity can represent a problem for its positioning as an effective antimicrobial compound. In contrast, the immunomodulatory peptide IDR-1018 presents low toxicity and a wide regenerative potential due to its ability to reduce apoptotic mRNA expression and promote skin cell proliferation. In the present study, we used human skin cells and a 3D skin equivalent models to analyze the potential of the IDR-1018 peptide to attenuate the cytotoxicity of synoeca-MP, as well as the influence of synoeca-MP/IDR-1018 combination on cell proliferation, regenerative processes, and wound repair. We found that the addition of IDR-1018 significantly improved the biological properties of synoeca-MP on skin cells without modifying its antibacterial activity against S. aureus. Likewise, in both melanocytes and keratinocytes, the treatment with synoeca-MP/IDR-1018 combination induces cell proliferation and migration, while in a 3D human skin equivalent model, it can accelerate wound reepithelization. Furthermore, treatment with this peptide combination generates an up-regulation in the expression of pro-regenerative genes in both monolayer cell cultures and in 3D skin equivalents. This data suggests that the synoeca-MP/IDR-1018 combination possesses a good profile of antimicrobial and pro-regenerative activity, opening the door to the development of new strategies for the treatment of skin lesions.

Potential involvement of circulating extracellular vesicles and particles on exercise effects in malignancies.

Physical activity and exercise have been widely related to prevention, treatment, and control for several non-communicable diseases. In this context, there are innumerous pre-clinical and clinical evidence indicating the potential role of exercise, beyond cancer prevention and survival, improved quality of life, including on psychological components, bone health and cachexia, from cancer survivors is described as well. This mini-review raises the potential role of circulating extracellular and particles vesicles (EVPs) cargo, as exerkines, conducting several positive effects on adjacent and/or distant tissues such as tumor, immune, bone and muscle cells. We highlighted new perspectives about microRNAs into EVPs changes induced by exercise and its benefits on malignancies, since microRNAs can be implicated with intricated physiopathological processes. Potential microRNAs into EVPs were pointed out here as players spreading beneficial effects of exercise, such as miR-150-5p, miR-124, miR-486, and miRNA-320a, which have previous findings on involvement with clinical outcomes and as well as tumor microenvironment, regulating intercellular communication and tumor growth. For example, high-intensity interval aerobic exercise program seems to increase miR-150 contents in circulating EVPs obtained from women with normal weight or overweight. In accordance circulating EVPs miR-150-5p content is correlated with prognosis colorectal cancer, and ectopic expression of miR-150 may reduce cell proliferation, invasion and metastasis. Beyond the involvement of bioactive miRNAs into circulating EVPs and their pathways related to clinical and preclinical findings, this mini review intends to support further studies on EVPs cargo and exercise effects in oncology.

Investigation of G4(MP2)-XK theory for antimony compounds' thermochemistry.

The heats of formation of thirty-five molecules containing antimony atoms have been calculated using G4(MP2)-XK, B3LYP, M06, M06-HF, M06-2X, BMK, wB97XD, and TPSSh atomization. The discrepancies between the predicted and the reported heats of formation vary in the range of 0.0-83 kcal mol-1 when compared with experimental and literature. The best agreement with experimental and literature data was achieved by using G4(MP2)-XK. The functionals used did not show results as good as G4(MP2)-XK. In its development, G4 (MP2)-XK showed itself comparable in accuracy to the G4(MP2)-6X. Importantly, the precision of G4(MP2)-XK for heavier elements such as antimony is similar to that of the first- and second-row species, although it contains parameters that are only adjusted to the systems of the first two rows. In this study, we can observe that G4(MP2)-XK has excellent requirements for elements such as antimony and leads us to believe that its scope will be further expanded in future studies with formation enthalpy such as iodine and xenonium.

An inception-based deep multiparametric net to classify clinical significance MRI regions of prostate cancer.

Objective.Multi-parametric magnetic resonance imaging (MP-MRI) has played an important role in prostate cancer diagnosis. Nevertheless, in the clinical routine, these sequences are principally analyzed from expert observations, which introduces an intrinsic variability in the diagnosis. Even worse, the isolated study of these MRI sequences trends to false positive detection due to other diseases that share similar radiological findings. Hence, the main objective of this study was to design, propose and validate a deep multimodal learning framework to support MRI-based prostate cancer diagnosis using cross-correlation modules that fuse MRI regions, coded from independent MRI parameter branches.Approach.This work introduces a multimodal scheme that integrates MP-MRI sequences and allows to characterize prostate lesions related to cancer disease. For doing so, potential 3D regions were extracted around expert annotations over different prostate zones. Then, a convolutional representation was obtained from each evaluated sequence, allowing a rich and hierarchical deep representation. Each convolutional branch representation was integrated following a special inception-like module. This module allows a redundant non-linear integration that preserves textural spatial lesion features and could obtain higher levels of representation.Main results.This strategy enhances micro-circulation, morphological, and cellular density features, which thereafter are integrated according to an inception late fusion strategy, leading to a better differentiation of prostate cancer lesions. The proposed strategy achieved a ROC-AUC of 0.82 over the PROSTATEx dataset by fusing regions ofKtransand apparent diffusion coefficient (ADC) maps coded from DWI-MRI.Significance.This study conducted an evaluation about how MP-MRI parameters can be fused, through a deep learning representation, exploiting spatial correlations among multiple lesion observations. The strategy, from a multimodal representation, learns branches representations to exploit radio-logical findings from ADC andKtrans. Besides, the proposed strategy is very compact (151 630 trainable parameters). Hence, the methodology is very fast in training (3 s for an epoch of 320 samples), being potentially applicable in clinical scenarios.

Ammonia quantum tunneling in cold rare-gas He and Ar clusters and factorial design approach for methodology evaluation.

Quantum tunneling of the ammonia inversion motion and energy level splittings in He and Ar clusters were investigated. It was found that the double well potential (DWP) in He clusters is symmetrical and that the first layer of He atoms is able to model the system. The calculated tunneling splitting was in good agreement with the experimental, 36.4 and 24.6 cm[Formula: see text] respectively. For NH[Formula: see text] in Ar clusters, the DWP becomes slightly asymmetric, which is enough to decrease the resonance and make the symmetric DWP unable to model the system. An asymmetric potential was used and the result was in excellent agreement with the experimental splitting, of 9.0 and 10.6 cm[Formula: see text] respectively. Non-covalent interactions revealed that the asymmetry is caused by dissimilar interactions in each minimum of the double well potential. The effects of different methodologies were analyzed via a design of experiments approach. For the gas-phase NH[Formula: see text] molecule, only diffuse functions were statistically significant while for the NH[Formula: see text] embedded in He cluster both the MP2 method and polarization functions were significant. This tendency suggests higher order polarization functions may be essential to generate accurate barrier heights.

Determination of major elements in igneous rocks using microwave plasma atomic emission spectrometry (MP-AES).

An analytical method for sample preparation of igneous rocks and subsequent determination of Si, Na, K, Ca, Mg, Al, Fe, Mn, Ba, Sr, and Ti by means of microwave induced emission spectrometry (MP-AES) was developed and validated. The proposed sample preparation procedure avoids the use of perchloric acid and provided accurate results even for silicon determination using an acid digestion with hydrofluoric acid. The determination of major elements in rocks is required for the design of classification diagrams that provides relevant information for geochemical analysis.•MP-AES showed to be an adequate technique to measure major and some trace elements that are relevant for classification of igneous rocks.•This method is in better agreement with the principles of the Green Analytical Chemistry and constitutes a reliable alternative to classical analytical and tedious procedures used for geochemical analysis.•The methodology was successfully applied to chemical classification of rocks from Valle Chico (Uruguay) using a Total Alkali-Silica Diagram (TAS).

Determination of the standard enthalpy of formation of iodine compounds through the G2 and G3(MP2)//B3-SBK theories.

The domain of application of the G3(MP2)//B3-SBK theory was expanded, and its efficiency was evaluated to determinate enthalpies of formation of forty-one iodine compounds. The results were compared to those obtained with the G2 theory for the same set of molecules. The G3(MP2)//B3-SBK theory showed a mean deviation and deviation standard equal to 3.7 kcal mol-1 and 6.0 kcal mol-1, respectively. The G2 theory (mean deviation = 3.1 kcal mol-1 and standard deviation = 4.9 kcal mol-1) presented a lower error and standard deviation, but at a significantly higher computational cost. For a more complete evaluation, as a secondary part of the work, it also used different functionals B3LYP, M06-2X, WB97XD, and MP2 method with four different basis sets 6-311G(d,p), LANL2DZ, jorge-ADZP, and CEP-31G(d). The best density functional/basis set combination was obtained with M06-2X/CEP-31G(d) among the three mentioned functionals. However, the produced mean deviation is significant and equal to 17.3 kcal mol-1, with a standard deviation equal to 23.0 kcal mol-1. The 6-311G(d,p) basis achieved the best performance with the MP2 method, generating an equally significant mean deviation of 12.8 kcal mol-1 with a standard deviation equal to 18.7 kcal mol-1.

Electrochemical detection of gram-negative bacteria through mastoparan-capped magnetic nanoparticle.

The increasing number of multidrug resistance microorganisms is an alarming threat, and their rapid detection is essential to prevent nosocomial, foodborne, or waterborne infections. Many peptides derived from the venom of wasp Synoeca surinama have antimicrobial activity against Gram-positive and Gram-negative bacteria. Synoeca-MP, an antimicrobial peptide (AMP) from mastoparan family, seems to increase bacterial membrane permeability, promoting cytotoxicity and membrane disruption. Here Synoeca-MP was evaluated as biorecognition element tethered over chitosan-coated magnetic nanoparticles (Fe3O4-Chit). The transducing layer of the biosensor was developed from the self-assembling of 4-mercaptobenzoic acid (4-MBA) monolayer onto gold substrate. Atomic force microscopy (AFM) analyses confirmed the biointeraction between AMP and different pathogens membranes. The fabrication and performance of the biosensing assembly were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Detection of Enterococcus faecalis (G+), Klebsiella pneumoniae (G-), Pseudomonas aeruginosa (G-), and Candida tropicalis was assessed in a recognition range from 101 to 105 CFU.mL-1. An instrumental limit of detection of 10 CFU.mL-1 was obtained for each specimen. However, the device presented a preferential selectivity towards Gram-negative bacteria. The proposed biosensor is a sensitive, fast, and straightforward platform for microbial detection in aqueous samples, envisaged for environmental monitoring applications.

Trifluoromethyl-stabilized 2D nitrogen clusters: a theoretical study.

The stability of 2D all nitrogen clusters containing from 6 to 96 nitrogen atoms, terminated with CF3 groups, has been explored using two computational models: dispersion corrected B3LYP functional and scaled opposite spin Møller-Plesset perturbation theory (SOS-MP2). Single point domain-based local pair natural orbital coupled-cluster theory calculations (DLPNO-CCSD(T)) was used for further energy refinement. All systems were found to be minima, and their stability increases with CF3/N ratio. Larger clusters and anion radicals were not dynamically stable, while some of the cation radicals were found to be minima on potential energy surface. The mechanism of cluster stabilization by CF3 groups is related with interaction of orbitals holding lone electron pairs and antibonding sigma orbitals.

Application of microwave plasma atomic emission spectrometry in bioanalytical chemistry of bioactive rhenium compounds.

Five newly synthetized fac-Re(I) tricarbonyl compounds were explored as prospective antitrypanosomal agents. The biological activity of the whole series was evaluated preliminarily against the epimastigote form of Trypanosoma cruzi. All compounds showed activity against epimastigotes with IC50 values in the low micromolar range. The most active compound [fac-Re(I)(CO)3(tmp)(CTZ)](PF6), with CTZ = clotrimazole and tmp = 3,4,7,8-tetramethyl-1,10-phenantroline, showed good selectivity towards the parasites and thus was selected to carry out further metallomic studies. For this task, a newly bioanalytical method based on microwave plasma atomic emission spectrometry (MP-AES) was developed and validated. The accuracy of the method was ensured by testing a certified reference material. Results of rhenium elemental analysis by MP-AES agreed with the proposed formula of the studied compounds, contributing to the overall validation of the method, which was then applied to evaluate the percentage of rhenium uptaken by the parasites and the association of the compounds with parasite biomacromolecules. Metallomics results showed low total rhenium percentage uptaken by parasites (∼1.2%) and preferential accumulation in the soluble proteins fraction (∼82.8%). Thus, the method based on MP-AES turned out to be an economical and green alternative for metallomics studies involving potential rhenium metallodrugs. Moreover, a comparison against rhenium determination by electrothermal atomic absorption spectrometry (ET-AAS) was included.

In Vivo Visualization of Mobile mRNA Particles in Plants Using BglG.

Cells have developed mechanisms for cytoplasmic RNA transport and localization that participate in the regulation and subcellular localization of protein synthesis. In addition, plants can exchange RNA molecules between cells through plasmodesmata and to distant tissues in the phloem. These mechanisms are hijacked by RNA viruses to establish their replication complexes and to disseminate their genomes throughout the plant organism with the help of virus-encoded movement proteins (MP). Live imaging of RNA molecules is a fundamental approach to understand the regulation and molecular basis of these processes. The most widely used experimental systems for the in vivo visualization of genetically encoded RNA molecules are based on fluorescently tagged RNA binding proteins that bind to specific motifs inserted into the RNA, thus allowing the tracking of the specific RNA molecule by fluorescent microscopy. Recently, we developed the use of the E. coli RNA binding protein BglG for the imaging of RNAs tagged with BglG-binding sites in planta. We describe here the detailed method by which we use this in vivo RNA tagging system for the real-time imaging of Tobacco mosaic virus (TMV) MP mRNA.

Synergistic activity and immunomodulatory potential of levofloxacin and Synoeca-MP peptide against multi-resistant strains of Klebsiella pneumoniae.

The purpose of this article is to study the isolated and combined effect of the peptides Synoeca-MP and IDR-1018 against multi-resistant clinical isolates of K. pneumoniae (Kp2177569 - LACEN) in vitro. The bactericidal activity of the peptide Synoeca-MP in combination with three different classes of commercial antimicrobials and its immunomodulatory potential was also evaluated. Synoeca-MP showed better antimicrobial activity than IDR-1018 and presented synergistic action combined with levofloxacin. Therefore, Synoeca-MP and levofloxacin, and the combination of both, were used in subsequent analyses. In the presence of heat-killed antigens, cellular viability and TNF-α levels was maintained, the production of NO increased and a reduction in IL-10 production was observed. The synergistic antibacterial effect between Synoeca-MP and levofloxacin was effective against multidrug-resistant strains of K. pneumoniae. The association of Synoeca-MP and levofloxacin may present a low modulating action of pro and anti-inflammatory mediators, based on these results.

Candida rugosa lipase immobilized on hydrophobic support Accurel MP 1000 in the synthesis of emollient esters.

OBJECTIVES: To immobilize Candida rugosa lipase in Accurel MP 1000 (CRL-AMP) by physical adsorption in organic medium and apply in the synthesis of wax esters dodecanoyl octadecanoate 1 and hexadecanoyl octadecanoate 2 in a heptane medium, as well as evaluating the stability and recyclability of CRL-AMP in six reaction cycles. RESULTS: The specific activity (Asp) for CRL-AMP was 200 ± 20 U mg-1. Its catalytic activity was 1300 ± 100 U g-1. CRL-AMP was used in the synthesis of esters in heptane medium with a 1:1 acid:alcohol molar ratio at 45 °C and 200 rpm. In synthesis 1, conversion was 62.5 ± 3.9% in 30 min at 10% m v-1 and 56.9 ± 2.8% in 54 min at 5% m v-1; while in synthesis 2, conversion was 79.0 ± 3.9% in 24 min at 10% m v-1, and 46.0 ± 2.4% in 54 min at 5% m v-1. Reuse tests after six consecutive cycles of reaction showed that the biocatalyst retained approximately 50% of its original activity for both reaction systems. CONCLUSIONS: CRL-AMP showed a high potential in the production of wax esters, since it started from low enzymatic load and high specific activities and conversions were obtained, in addition to allowing an increase in stability and recyclability of the prepared biocatalyst.

Activation of YAP regulates muscle fiber size in a PKC-dependent mechanism during chick in vitro myogenesis.

The formation of skeletal muscle fibers is an intricate process controlled by a multitude of signaling pathways, including Wnt, Shh, and FGF. However, the role of the Hippo pathway during vertebrate myofiber formation has conflicting reports, which we decided to address in chick muscle cultures. We found that the transcriptional regulator Yes-associated protein (YAP) was highly concentrated within the nuclei of myoblasts. As cells differentiate into myotubes, YAP localization shifted to the cell cytoplasm in more mature myotubes. Treatment of cultures with XMU-MP-1 (XMU), a MST1/2 inhibitor, stimulated the nuclear localization of YAP in myoblasts and in myotubes, upregulated myogenin, and promoted myoblast fusion, ultimately resulting in the formation of large and fully striated multinucleated myotubes. The XMU-induced phenotype was blocked by the protein kinase C (PKC) inhibitor calphostin, which raises the possibility that the Hippo pathway controls the growth of skeletal muscle fibers through a PKC-dependent mechanism.