Caracterización morfológica de la semilla de Hibiscus cannabinus (Malvaceae) e influencia del tiempo de almacenamiento sobre la viabilidad

Hibiscus cannabinus L. (Malvaceae) “kenaf ” es una especie de ciclo anual primavero-otoñal, que se cultiva para la producción de fibra para papel, bioetanol de segunda generación y forraje. Los objetivos de esta investigación fueron caracterizar la morfología de la semilla de H. cannabinus y establecer la influencia del tiempo de almacenamiento sobre la viabilidad de dos cultivares, Endora y Tainung 1. Se realizaron observaciones de cortes histológicos y mediciones con microscopio óptico y estereoscópico. Se evaluó la germinación a los 30, 180 y 730 días después de cosecha. Las semillas de H. cannabinus presentan una forma asimétrica, cuneiforme y/o triangular (ca. 5,1 mm x 2,8 mm), son endospermadas y derivan de óvulos campilótropos. La cubierta seminal tiene tricomas unicelulares, eglandulares distribuidos en toda la superficie con predominio en la región del hilo. El embrión es plegado, con cotiledones conduplicados de posición axial sub tipo curvo. El episperma presenta un marcado predominio de la capa de macroesclereidas. Se encontró que las semillas de los cultivares Endora y Tainung 1, almacenadas por dos años a temperatura ambiente y con 9,5% de humedad, mantienen un alto porcentaje de germinación con valores cercanos al 80%. Los resultados permiten afirmar que las semillas de “kenaf ” mantienen las características morfológicas internas constantes típicas de las Malváceas, y que los cultivares estudiados presentan una alta viabilidad sostenida en el tiempo

Evaluación sistématica de la degradación de materiales sometidos al intemperismo

La necesidad de actividades de restauración y conservación del patrimonio deriva de la acción agresiva que ejercen los agentes ambientales sobre los materiales de construcción. En la actualidad, existen numerosos proyectos destinados a evaluar el comportamiento de estos materiales en ambientes de elevada agresividad, tales como las atmósferas marinas e industriales. Sin embargo, no se conocen iniciativas similares que estén orientadas al estudio de los deterioros que se producen en climas menos severos, y que en nuestro país representan las condiciones de una extensa región. Por otra parte, para diseñar las medidas de reparación y conservación de las construcciones resulta indispensable contar con herramientas que permitan evaluar en forma sistemática el comportamiento de los materiales y la evolución de los deterioros que ellos sufren, a fin de determinar las causas de degradación. Posteriormente, estas mismas herramientas deben permitir monitorear la efectividad de los métodos de reparación aplicados. Los profesionales que desean conocer con certeza el comportamiento de los materiales ante el paso del tiempo y su respuesta ante las distintas condiciones de exposición deben recurrir a datos suministrados por el fabricante o antecedentes existentes en la bibliografía específica y provenientes de investigaciones realizadas al respecto. Muchas de estas fuentes se encuentran desactualizadas, no corresponden a las condiciones de exposición específicas o bien carecen de valor técnico. El CECOVI, dentro de las actividades de investigación y desarrollo de materiales de construcción y sistemas constructivos que lleva adelante, está desarrollando un proyecto que tiene por objetivo principal el abordaje sistemático de la problemática de la durabilidad de los materiales de construcción sometidos a la acción de la intemperie y su aptitud en servicio. Este proyecto se circunscribe, actualmente, al estudio de la durabilidad de hormigones convencionales y elaborados con agregados livianos, hormigones celulares, madera, suelocemento y materiales plásticos, mientras que el tipo de exposición se limita a las condiciones de intemperismo habituales en un clima templado húmedo, de acuerdo a la clasificación establecida por el Sistema Internacional de Koeppen. Paralelamente, se realizan contrastes con materiales mantenidos en condiciones de laboratorio que actúan como patrones de comparación. Los ejes fundamentales planteados están constituidos por el análisis teórico, el seguimiento sistemático del comportamiento de materiales ante condiciones reales de exposición y en condiciones de envejecimiento acelerado, tendientes al establecimiento de una metodología de evaluación de aplicabilidad general, correlaciones entre el deterioro de los materiales y variables ambientales típicas de la región y el desarrollo de técnicas que permitan predecir su vida útil

VARIAÇÕES ANATÔMICAS DO CANAL MANDIBULAR

O trabalho irá apresentar a prevalência dos diferentes trajetos do canal mandibular. Tendo por objetivo destacar essas já conhecidas variações anatômicas do canal mandibular e informar os profissionais da área da saúde quanto à existência das mesmas, bem como suas condutas clínicas frente a esses achados anatômicos. Foram avaliadas 211 radiografias panorâmicas de pacientes atendidos no curso de odontologia da UFPR no período de 2005 a 2006. Os pacientes eram brasileiros, de ambos sexos, com idades entre 7 e 84 anos. As radiografias foram avaliadas por 3 pesquisadores após calibração prévia, sobre negastocópio adequado. Utilizou-se a classificação de LANGLAIS et al (1985). Das 211 radiografias avaliadas 2,36% (5casos) apresentaram canal mandibular ramificados, sendo que destes 2 apresentavam ramificação para o terceiro molar bilateralmente, 1 ramificação para o terceiro molar unilateralmente e 2 ramificação limitada ao ramo mandibular bilateralmente. Pode-se confirmar que o canal mandibular pode apresentar variações em sua trajetória, sendo extremamente importante a verificação criteriosa do mesmo em radiografias panorâmicas prévias ao tratamento a fim de se estabelecer um plano de tratamento adequado para o pacient

Primary structure and spectroscopic studies of Neurospora copper metallothionein.

When Neurospora crassa is grown in the presence of Cu(II) ions, it accumulates the metal with the concomitant synthesis of a low molecular weight copper-binding protein. The molecule binds 6 g-atom of copper per mole protein (Mr = 2200) and shows a striking sequence homology to the zinc- and cadmium-binding vertebrate metallothioneins. Absorption, circular dichroism, and electron paramagnetic resonance spectroscopy of Neurospora metallothionein indicate the copper to be bound to cysteinyl residues as a Cu(I)-thiolate complex of the polymeric mu-thiolate structure [Cu(I)6RS7]-. This metal-binding mode is also in agreement with the unusual luminescence of the protein. Spectral perturbation studies with HgCl2 and p-(chloromercuri)benzoate suggest that the 6 Cu(I)ions are coordinated to the seven cysteinyl residues in the form of a single metal cluster. Neurospora apometallothionein is also capable of binding in vivo group IIB metal ions [Zn(II), Cd(II), and Hg(II)] as well as paramagnetic Co(II) ions with an overall metal-to-protein stoichiometry of 3. The spectroscopic properties of the fully substituted forms are indicative of a distorted tetrahedral coordination. However, metal titration of the apoprotein shows the third metal ion to be differently coordinated than the other two metal ions. This difference can be explained by the presence of only seven cysteine residues in Neurospora metallothionein as opposed to nine cysteine residues in the three-metal cluster of the mammalian metallothioneins

Resistance to stress and Hc functional modulation in Liocarcinus sp

This study is included in a project aimed to study the alterations on the structure of the Northern Adriatic Sea ecosystem produced by fishing activity. The indirect or secondary effects of fishery such as the changes of the structure and trophic relationships of the ecosystem are under investigation and we have particularly considered the effects on species such as Liocarcinus depurator that are captured and then rejected because devoid of commercial value. The objective of this study is the Liocarcinus sp. adaptative resistance to stress and the effects of biochemical parameters (allosteric effectors) on Hc functional modulation

Structural and functional heterogeneity of hemocyanin: intra- and inter-specific comparison in four species of portunid crabs (Crustacea: Portunidae)

This work is focused on hemocyanin (Hc) heterogeneity at population level and on the biochemical characterization of the different subunit patterns. Two different approaches have been used: we have characterized Hc subunit composition to describe the subunit polymorphism. Then, we have measured the Hc oxygen-binding affinity to disclose the physiological implications of such heterogeneity. In order to evaluate the intra- and inter-specific variability, different populations of Liocarcinus depurator, Liocarcinus marmoreus, Liocarcinus holsatus, Necora puber (Crustacea: Portunidae), from British Isles and Adriatic Sea, have been sampled. Results indicate that Hc polymorphism normally occurs at both intra- and interspecific levels and involves the protein subunit type. These evidences extend to the portunid Hc the concept of molecular heterogeneity within species that have been previously reported for other decapod and amphipod crustaceans. Besides, the results support the view that subunit composition of crustacean Hcs is almost species-specific, but also that closely related species share a common pattern. Furthermore, this heterogeneity corresponds to different stability of the native oligomers quaternary structure and different oxygen affinity. The results are discussed in relation with the environmental regimes that characterize the different sampling areas. In addition to Hc, the hemolymph collected in specimens from different sampling areas contained also a non-respiratory pseudo-Hc. This paper reports for the first time the occurrence of pseudo-Hc at the level of population

Hypersensitivity to Imatinib: Successful Desensitization in a Skin Test–Positive Patient

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Physico-chemical and antifungal properties of protease inhibitors from Acacia plumosa

This study was aimed at investigating the purification, biological activity, and some structural properties of three serine protease inhibitors isoforms, denoted ApTIA, ApTIB, and ApTIC from Acacia plumosa Lowe seeds. They were purified from the saline extract of the seeds, using Superdex-75 gel filtration and Mono-S ion exchange chromatography. They were further investigated by mass spectrometry, spectroscopic measurements, surface plasmon resonance, and inhibition assays with proteases and phytopathogenic fungi. The molecular mass of each isoform was estimated at ca. 20 kDa. Each contained two polypeptide chains linked by a disulfide bridge, with different isoelectric points that are acidic in nature. The N-terminal sequences of both chains indicated that they were Kunitz-type inhibitors. Circular dichroism (CD) analyses suggested the predominance of both disordered and beta-strands on ApTI isoforms secondary structure, as expected for β-II proteins. In addition, it was observed that the proteins were very stable, even at either extreme pH values or at high temperature, with denaturation midpoints close to 75 °C. The isoinhibitors could delay, up to 10 times, the blood coagulation time in vitro and inhibited action of trypsin (Ki 1.8 nM), α-chymotrypsin (Ki 10.3 nM) and kallikrein (Ki 0.58 μM). The binding of ApTIA, ApTIB, and ApTIC to trypsin and α-chymotrypsin, was investigated by surface plasmon resonance (SPR), this giving dissociation constants of 0.39, 0.56 and 0.56 nM with trypsin and 7.5, 6.9 and 3.5 nM with α-chymotrypsin, respectively. The growth profiles of Aspergillus niger, Thielaviopsis paradoxa and Colletotrichum sp. P10 were also inhibited by each isoforms. These three potent inhibitors from A. plumosa may therefore be of great interest as specific inhibitors to regulate proteolytic processes.FAPESPCNP

Open reduction and internal fixation without rigid maxillomandibular fixation: evidence based or merely a surgical dictum? A comparative pilot study on 24 cases

OBJECTIVE: The objective of the study was to evaluate the results and immediate postoperative complications following open reduction and internal fixation of mandibular fractures with or without postoperative maxillo-mandibular fixation MATERIALS AND METHODS: The study spanned over a period of 24 months, extending from October 2015 to October 2017. The study sample comprised 24 subjects between the age range of 18 to 65 years. They were randomly divided into two groups: Group A included subjects in whom open reduction and internal fixation was followed by maxilla-mandibular fixation for 15 days, and Group B subjects in whom only open reduction and internal fixation was done, followed by immediate mobilization. The outcomes evaluated were swelling, pain, simplified oral hygiene index and occlusion. The subjects were followed for all these outcomes on 1st, 7th and 15th days. The occlusion was assessed for 5 days. Any other intra/post-operative complications were additionally noted. RESULTS: There was no statistical difference between the groups for swelling, pain and occlusion. The patients with postoperative maxilla-mandibular fixation had poorer oral hygiene when compared to the other group (p<0.001). CONCLUSIONS: The use of maxilla-mandibular fixation post open reduction and internal fixation seems to offer no additional benefits to the patients. According to the results of the study, this traditional surgical dictum seems to be used by the surgeons due to the lack of any scientific evidence. However, further studies should be conducted to confirm this statement

Accuracy of ChatGPT-Generated Information on Head and Neck and Oromaxillofacial Surgery: A Multicenter Collaborative Analysis

Objective: To investigate the accuracy of Chat-Based Generative Pre-trained Transformer (ChatGPT) in answering questions and solving clinical scenarios of head and neck surgery. Study Design: Observational and valuative study. Setting: Eighteen surgeons from 14 Italian head and neck surgery units. Methods: A total of 144 clinical questions encompassing different subspecialities of head and neck surgery and 15 comprehensive clinical scenarios were developed. Questions and scenarios were inputted into ChatGPT4, and the resulting answers were evaluated by the researchers using accuracy (range 1-6), completeness (range 1-3), and references' quality Likert scales. Results: The overall median score of open-ended questions was 6 (interquartile range[IQR]: 5-6) for accuracy and 3 (IQR: 2-3) for completeness. Overall, the reviewers rated the answer as entirely or nearly entirely correct in 87.2% of cases and as comprehensive and covering all aspects of the question in 73% of cases. The artificial intelligence (AI) model achieved a correct response in 84.7% of the closed-ended questions (11 wrong answers). As for the clinical scenarios, ChatGPT provided a fully or nearly fully correct diagnosis in 81.7% of cases. The proposed diagnostic or therapeutic procedure was judged to be complete in 56.7% of cases. The overall quality of the bibliographic references was poor, and sources were nonexistent in 46.4% of the cases. Conclusion: The results generally demonstrate a good level of accuracy in the AI's answers. The AI's ability to resolve complex clinical scenarios is promising, but it still falls short of being considered a reliable support for the decision-making process of specialists in head-neck surgery