Self-assembly of Fmoc-tetrapeptides based on the RGDS cell adhesion motif

Self-assembly in aqueous solution has been investigated for two Fmoc [Fmoc ¼ N-(fluorenyl)-9-methoxycarbonyl] tetrapeptides comprising the RGDS cell adhesion motif from fibronectin or the scrambled sequence GRDS. The hydrophobic Fmoc unit confers amphiphilicity on the molecules, and introduces aromatic stacking interactions. Circular dichroism and FTIR spectroscopy show that the self-assembly of both peptides at low concentration is dominated by interactions among Fmoc units, although Fmoc-GRDS shows b-sheet features, at lower concentration than Fmoc-RGDS. Fibre X-ray diffraction indicates b-sheet formation by both peptides at sufficiently high concentration. Strong alignment effects are revealed by linear dichroism experiments for Fmoc-GRDS. Cryo-TEM and smallangle X-ray scattering (SAXS) reveal that both samples form fibrils with a diameter of approximately 10 nm. Both Fmoc-tetrapeptides form self-supporting hydrogels at sufficiently high concentration. Dynamic shear rheometry enabled measurements of the moduli for the Fmoc-GRDS hydrogel, however syneresis was observed for the Fmoc-RGDS hydrogel which was significantly less stable to shear. Molecular dynamics computer simulations were carried out considering parallel and antiparallel b-sheet configurations of systems containing 7 and 21 molecules of Fmoc-RGDS or Fmoc-GRDS, the results being analyzed in terms of both intermolecular structural parameters and energy contributions

A New Species of \u3ci\u3eAcanthobothrium\u3c/i\u3e Van Beneden, 1849 (Eucestoda: Tetraphyllidea: Onchobothriidae) in \u3ci\u3eDasyatis longus\u3c/i\u3e Garman (Chondrichthyes: Myliobatiformes: Dasyatididae) from Chamela Bay, Jalisco, Mexico

A new species of Acanthobothrium in Dasyatis longus from Chamela Bay, Jalisco, Mexico, is a member of a presumed clade of species diagnosed by being anapolytic or nearly so, having more than 100 testes per proglottis, with immature and mature proglottides wider than long to square, aspinose scolex, muscular bothridia fused to the scolex at their posterior ends, H- to V-shaped ovaries, relatively short symmetrical to asymmetrical ovarian arms that extend anteriorly to, or nearly to, the cirrus sac, and vitellaria arranged in fields rather than a single row of follicles. The new species most closely resembles Acanthobothrium terezae from the freshwater stingray Potamotrygon motoro in the following characters: bothridial hooks longer than 200 μm with inner hooks having bent asymmetrical prongs, an average of 130-140 testes per proglottis, and shallow genital atria located posterior to midline of proglottis. The new species differs from A. terezae by having outer hooks approximately the same size and shape as the inner hooks, inner hooks averaging 230 μm rather than 313 μm in total length, and cirrus sacs averaging 255 μm rather than 450 μm in length. The new species is unique among all described species of Acanthobothrium by having a cleft in the posterior margin of each apical bothridial pad. The apparent close relationship of the new species to one inhabiting a Neotropical freshwater stingray provides support for the hypothesized Pacific marine ancestry of Neotropical freshwater stingrays and raises the possibility that the Neotropical freshwater stingrays may not be monophyletic

Clavo gamma en el tratamiento de las fracturas del macizo trocantérico: estudio comparativo entre el Clavo Gamma Trocantérico y el Gamma 3

El clavo Gamma es una técnica bien establecida en el tratamiento de las fracturas del macizo trocantéreo. Hemos realizado un estudio prospectivo en 40 pacientes para comparar dos tipos de clavos. En 20 se utilizó el clavo gamma trocantérico y en 20 un nuevo dispositivo llamado Gamma3 fabricado en titanio y con modificaciones en el diseño para permitir una menor incisión y mayor faciliad en su implante. De todos los parámetros estudiados tanto intra como postoperatorios sólo hemos encontrado diferencias en cuanto al tiempo del acto quirúrgico y al tamaño de la incisión, encontrando menor tiempo y menor tamaño de la incisión en el clavo gamma 3. No encontramos diferencias en cuanto a las complicaciones técnicas, ni en cuanto al dolor, tiempo transcurrido hasta la consolidación o grado de independencia obtenido. Consideramos el clavo Gamma3 como una técnica valiosa que disminuye el tiempo de cirugía y el traumatismo de las partes blandas.The nail Gamma is a well-established technique in the treatment of the trochanteric fractures. We have made a prospective study in 40 patients for compare two Gamma nail types. In 20 we use the Trochanteric Gamma Nail and in 20 a new device called Gamma 3 manufactured in titanium and with modifications in the design to permit a less incision and most facilities in his implantation. Of all of the parameters studied both intra and postoperative we have found differences in the time of surgical act and in the size of the incision, finding less time and less size of the approach in the gamma 3 nail. We do not find differences about technical complications, neither as to the pain, time to the consolidation or independence grade obtained. We regard to the nail Gamma 3 as a valuable technique that decreases the time of surgery and the traumatism of the soft tissues

Parabolic stable surfaces with constant mean curvature

We prove that if u is a bounded smooth function in the kernel of a nonnegative Schrodinger operator $-L=-(\Delta +q)$ on a parabolic Riemannian manifold M, then u is either identically zero or it has no zeros on M, and the linear space of such functions is 1-dimensional. We obtain consequences for orientable, complete stable surfaces with constant mean curvature $H\in\mathbb{R}$ in homogeneous spaces $\mathbb{E}(\kappa,\tau)$ with four dimensional isometry group. For instance, if M is an orientable, parabolic, complete immersed surface with constant mean curvature H in $\mathbb{H}^2\times\mathbb{R}$, then $|H|\leq 1/2$ and if equality holds, then M is either an entire graph or a vertical horocylinder.Comment: 15 pages, 1 figure. Minor changes have been incorporated (exchange finite capacity by parabolicity, and simplify the proof of Theorem 1)

Reproductive biology of male franciscanas (Pontoporia blainvillei) (Mammalia: Cetacea) from Rio Grande do Sul, southern Brazil

The reproductive biology of male franciscanas (Pontoporia blainvillei), based on 121 individuals collected in Rio Grande do Sul State, southern Brazil, was studied. Estimates on age, length, and weight at attainment of sexual maturity are presented. Data on the reproductive seasonality and on the relationship between some testicular characteristics and age, size, and maturity status are provided. Sexual maturity was assessed by histological examination of the testes. Seasonality was determined by changes in relative and total testis weight, and in seminiferous tubule diameters. Testis weight, testicular index of maturity, and seminiferous tubule diameters were reliable indicators of sexual maturity, whereas testis length, age, length, and weight of the dolphin were not. Sexual maturity was estimated to be attained at 3.6 years (CI 95% =2.7–4.5) with the DeMaster method and 3.0 years with the logistic equation. Length and weight at attainment of sexual maturity were 128.2 cm (CI 95%=125.3–131.1 cm) and 26.4 kg (CI 95% =24.7–28.1 kg), respectively. It could not be verified that there was any seasonal change in the testis weight and in the seminiferous tubule diameters in mature males. It is suggested that at least some mature males may remain reproductively active throughout the year. The extremely low relative testis weight indicates that sperm competition does not occur in the species. On the other hand, the absence of secondary sexual characteristics, the reversed sexual size dimorphism, and the small number of scars from intrassexual combats in males reinforce the hypothesis that male combats for female reproductive access may be rare for franciscana. It is hypothesized that P. blainvillei form temporary pairs (one male copulating with only one female) during the reproductive period

Etiopathogenesis of ovarian cancer. An inflamm-aging entity?

Ovarian cancer is one of the most common gynecologic cancers and has the highest mortality rate. The risk/protective factors of ovarian cancer suggest that its etiology is multifactorial. Several factors are involved in age-related increases in carcinogenesis, including the accumulation of senescent cells, inflammaging (a chronic inflammatory state that persists in the elderly), and immunosenescence (aging of the immune system) changes associated with poor immune surveillance. At sites of inflammation, exposure to high levels of inflammatory mediators, such as reactive oxygen species, cytokines, prostaglandins, and growth factors, contributes to increased cell division and genetic and epigenetic changes. These exposure-induced changes promote excessive cell proliferation, increased survival, malignant transformation, and cancer development. Furthermore, the proinflammatory tumor microenvironment contributes to ovarian cancer metastasis and chemoresistance. This narrative review of the literature was carried out to delineate the possible role of inflammaging in the etiopathogenesis of ovarian cancer development. We discuss the current carcinogenic hypotheses, sites of origin, and etiological factors of ovarian cancer. Treatment of inflammation may represent an attractive strategy for both the prevention and therapy of ovarian cancer. © 2022 The Author(s

New insights into oxygen surface coverage and the resulting two-component structure of graphene oxide

Elucidating the essential details of the structure of graphene oxide (GO) is still a challenge. There is no consensus in the increasingly abundant literature, especially relating to the epoxy groups as the main surface complexes in the basal plane, as well as the simultaneous presence of GO sheets and oxidative debris (OD), with a large difference in their oxygen content. In the present work we characterized the base-washed GO (bwGO) sheets, the OD and the humic fraction of the OD obtained by base digestion, when the parent GO was dispersed by applying sonication, a routine procedure when starting from dried graphite oxide. When sonication is not applied, the amount of OD detected is considerably lower, indicative of its formation before base digestion. The presence of lactols and carboxylic anhydrides as the dominant surface complexes at graphene edges is consistent with all the characterization results, as well as with the general knowledge of surface chemistry of carbon materials ranging from coal to graphite. These findings suggest that the Hummers-Offeman reaction produces a chemical scissor effect during the water/hydrogen peroxide quenching step, yielding a broad size distribution of GO sheets, with little in-plane oxidation and the vast majority of edges being oxidized to form oxepinone-type functionalities.The authors gratefully acknowledge the financial support of the Ministerio de Economía y Competitividad of Spain (Project CTQ2013-44213-R), and Generalitat Valenciana (project PROMETEOII/2014/007). LRR is grateful for the support of CONICYT-Chile (project Fondecyt 1160949)

Model-Driven Chatbot Development

Esta versión del artículo ha sido aceptada para su publicación, después de la revisión por pares (cuando corresponda) y está sujeta a los términos de uso de AM de Springer Nature, pero no es la Versión de Registro y no refleja mejoras posteriores a la aceptación, ni ninguna corrección. La versión del registro está disponible en línea en: https://doi.org/10.1007/978-3-030-62522-1_15Chatbots are software services accessed via conversation in natural language. They are increasingly used to help in all kinds of procedures like booking flights, querying visa information or assigning tasks to developers. They can be embedded in webs and social networks, and be used from mobile devices without installing dedicated apps. While many frameworks and platforms have emerged for their development, identifying the most appropriate one for building a particular chatbot requires a high investment of time. Moreover, some of them are closed – resulting in customer lock-in – or require deep technical knowledge. To tackle these issues, we propose a model-driven engineering approach to chatbot development. It comprises a neutral meta-model and a domainspecific language (DSL) for chatbot description; code generators and parsers for several chatbot platforms; and a platform recommender. Our approach supports forward and reverse engineering, and model-based analysis. We demonstrate its feasibility presenting a prototype tool and an evaluation based on migrating third party Dialogflow bots to RasaWork funded by the Spanish Ministry of Science (RTI2018095255-B-I00) and the R&D programme of Madrid (P2018/TCS-4314

Turn-on fluorescent probes for nitric oxide sensing based on the the ortho-hydroxyamino structure showing no interference with dehydroascorbic acid

A new family of fluorescent synthetic molecular probes for nitric oxide sensing based on ortho-hydroxyamino-triarylpyrylium salts is presented