Speed and power predictors of change of direction ability in elite snow athletes

Change of direction ability (COD speed) is an important physical component of snow sports. The aim of this study was to investigate the relationships between regular speed and vertical jumping ability, and COD speed in elite snow athletes. Moreover, the correlations between relative mean propulsive power (assessed in the jump squat exercise) and COD speed were quantified. Sixteen elite snow sport athletes executed squat jumps, countermovement jumps, jump squats, and 25 m sprint tests, in addition to a Zig-zag change of direction speed test. The outcomes revealed that vertical jumping height and mean propulsive power are strongly correlated (r ≈ 0.90) with COD speed. Furthermore, snow athletes capable of sprinting faster in a linear course of 25 m performed better in COD speed tests ( r = 0.91). Our results support the use of loaded and unloaded vertical jumping and regular speed tests to evaluate/monitor predictors of COD speed in elite snow athletes. Finally, these relationships suggest that plyometrics and regular speed training should be considered by coaches as effective strategies to enhance COD ability in this specific group of subjects

The stress responsive and morphologically regulated hsp90 gene from Paracoccidioides brasiliensis is essential to cell viability

<p>Abstract</p> <p>Background</p> <p><it>Paracoccidioides brasiliensis </it>is a dimorphic fungus that causes the most prevalent systemic mycosis in Latin America. The response to heat shock is involved in pathogenesis, as this pathogen switches from mycelium to yeast forms in a temperature dependent fashion that is essential to establish infection. HSP90 is a molecular chaperone that helps in the folding and stabilization of selected polypeptides. HSP90 family members have been shown to present important roles in fungi, especially in the pathogenic species, as an immunodominant antigen and also as a potential antifungal therapeutic target.</p> <p>Results</p> <p>In this work, we decided to further study the <it>Pbhsp90 </it>gene, its expression and role in cell viability because it plays important roles in fungal physiology and pathogenesis. Thus, we have sequenced a <it>Pbhsp90 </it>cDNA and shown that this gene is present on the genome as a single copy. We have also confirmed its preferential expression in the yeast phase and its overexpression during dimorphic transition and oxidative stress. Treatment of the yeast with the specific HSP90 inhibitors geldanamycin and radicicol inhibited growth at 2 and 10 μM, respectively.</p> <p>Conclusion</p> <p>The data confirm that the <it>Pbhsp90 </it>gene encodes a morphologically regulated and stress-responsive protein whose function is essential to cell viability of this pathogen. This work also enforces the potential of HSP90 as a target for antifungal therapies, since the use of HSP90 inhibitors is lethal to the <it>P. brasiliensis </it>yeast cells in a dose-responsive manner.</p

Uma nova espécie de Epiperipatus (Onychophora: Peripatidae) da região nordeste do Brasil

This article aims to describe and illustrate Epiperipatus cratensis sp. nov. from Crato (coordinates 07°16’S,39°26’W), Ceara State, Brazil. Specimens of onychophorans were collected under stones and decomposing tree barks during the rainy season. E. cratensis differs from all of the species of the genus by having: (i) many pairs of legs, even though it is the second smallest species in size to the genus in Brazil; (ii) fewer rings of antennas than the other Brazilian species. Furthermore, E. cratensis is similar to E. tucupi, especially because females have 34 pairs of legs, and differs morphologically only by being shorter in size. In addition, this two species are located in different biomes: E. tucupi is endemic to the Amazon region, while E. cratensis is derived from Chapada do Araripe mountains, within Atlantic Forest biome of the Brejos de Altitude complex of northeastern Brazil. Key words: high land humid forest, Epiperipatus, peripatidae, onychophora.O presente artigo visa descrever e ilustrar Epiperipatus cratensis sp. nov. proveniente de Crato (coordenadas 07°16’S, 39°26’W), Estado do Ceara, Brasil. Para tanto, os espécimes foram coletados sob pedras e cascas de arvores em decomposição durante a estação chuvosa. E. cratensis difere de todas as espécies do gênero por possuir: (i) um grande número de pares de pernas, mesmo sendo a segunda menor espécie em tamanho para o gênero no Brasil; (ii) menos anéis de antenas que as demais espécies brasileiras. Epiperipatus cratensis é semelhante a E. tucupi, principalmente porque as fêmeas apresentam 34 pares de pernas, diferindo morfologicamente apenas por serem de tamanho menor. Além disso, essas duas espécies estão inseridas em biomas distintos: a E. tucupi endêmica da região amazônica, enquanto a E. cratensis encontra-se na Chapada do Araripe, inserida no complexo dos brejos de altitude nordestinos na Mata Atlântica. Palavras-chave: brejos de altitude, E. cratensis, Onychophora, Peripatidae

Protective effects of Amburoside A, a phenol glucoside from Amburana cearensis, against CCl4-induced hepatotoxicity in rats.

The aim of this study was to investigate the possible beneficial effects of amburoside A, AMB [4-(0-b-d-glycopyranosyl) benzyl protocatechoate], against carbon tetrachloride (CCl) toxicity in rats

Monitoring the degradation and the corrosion of naphthenic acids by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and atomic force microscopy

AbstractAlthough the term “naphthenic acids” was originally used to describe acids that contain naphthenic rings, today this term is used in a more general sense and refers to all components in the acid extractable fraction. In crude oil, naphthenic acids exist as a complex mixture of compounds with broad polydispersity with respect to both molecular weight and structure. There has been increasing interest in the naphthenic acids in crude oil because of the corrosion problems that cause during oil refining. Herein, two powerful analytical tools, negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, ESI(-)FT-ICR MS and atomic force microscopy (AFM), were combined to monitor the thermal degradation of naphthenic acids and their corrosion effects on AISI 1020 steel, respectively. Two different acidic crude oils (TAN=2.38 and 4.79mgKOHg−1, and total sulfur=0.7993 and 1.0220wt%) have been submitted to thermal treatment at 280, 300 and 350°C during 2, 4 and 6h, and characterized by ESI(-)-FT-ICR MS, total acid number (TAN), and total sulfur. The AISI 1020 steel was analyzed by scanning electron microscopy (SEM) and AFM. Generally, heating the crude oil at 350°C in a period of 6h, it was observed that a high efficiency (≅80%) and selectivity of thermal decarboxylation process was monitored by decay of TAN (4.79→0.44mgKOHg−1). ESI(-)-FT-ICR MS results showed that naphthenic acid species remained after the heating have DBE ranging 1–12 and carbon number from C15 to C45. AFM topographic profile evidenced that the naphthenic acid corrosion of the crude oil with TAN of 4.73mgKOHg−1 on AISI 1020 steel was profoundly altered and a marked reduction in peak to peak height values (obtained by subtracting the value of the lowest peak by the highest peak in the topographic area examined). Optical images and microphotographs confirmed the presence of irregularities, characterizing the corrosion mechanism as pitting type. The naphthenic corrosion was also evidenced in samples with low TAN value (0.44mgKOHg−1)

Rutin-functionalized multi-walled carbon nanotubes: molecular docking, physicochemistry and cytotoxicity in fibroblasts

Multi-Walled Carbon Nanotubes (MWCNT) have been functionalized with rutin through three steps (i. reaction step; ii. purification step; iii. drying step) and their physicochemical properties investigated with respect to morphological structure, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR), and cytotoxicity. The molecular docking suggested the rutin-functionalized MWCNT occurred by hydrogen bonds, which was confirmed by FTIR assays, corroborating the results obtained by thermal analyses. A tubular shape, arranged in a three-dimensional structure, could be observed. Mild cytotoxicity observed in 3T3 fibroblasts suggested a doseeffect relationship after exposure. These findings suggest the formation of aggregates of filamentous structures on the cells favoring the cell penetration.The authors acknowledge Classius Ferreira da Silva, from the Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, for the scanning electron microscopy analyses.info:eu-repo/semantics/publishedVersio

It Takes Two to Tango, Part II : Synthesis of A-Ring Functionalised Quinones Containing Two Redox-Active Centres with Antitumour Activities

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/seleniumcontaining triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of paranaphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango