Competitive ligation between carbon monoxide and propiononitrile in chloro-complexes of platinum(II)

EtCN partially displaces coordinated carbon monoxide from cis-PtCl₂(CO)₂ giving an equilibrium mixture of the two geometrical isomers of PtCl₂(CO)(NCEt), together with unreacted cis-PtCl₂(CO)₂, as monitored by IR and NMR measurements. The equilibrium has also been studied starting from PtCl₂(NCEt)₂, through displacement of coordinated EtCN by CO. The equilibrium constant of the reaction between PtCl₂(CO)(NCEt) [cis + trans] and CO to produce cis-PtCl₂(CO)₂ (48 ± 6, corresponding to ΔG⁰ = −9.5 ± 0.3 kJ mol⁻¹) has been measured at 23.4 °C, in the presence of SnCl₂ as catalyst, the uncatalysed reaction being exceedingly slow. With an appropriate control of the CO partial pressure, PtCl₂(CO)(NCEt) was obtained in a nearly quantitative yield either from cis-PtCl₂(CO)₂ + EtCN or from PtCl₂(NCEt)₂ + CO. The molecular and crystal structure of cis-PtCl₂(CO)(NCEt) has been solved by X-ray diffractometry.     

Analysis on the activation of the VMO and VLL muscles during semisquat exercises with and without hip adduction in individuals with patellofemoral pain syndrome

Objective: The purpose of this study was to investigate the effect of hip adduction on the activity of the Vastus Medialis Obliquus (VMO) and Vastus Lateralis Longus (VLL) muscles during semisquat exercises.

Methods: Twenty female subjects, divided into two groups comprising healthy and patellofemoral pain syndrome (PFPS) subjects (ten volunteers for each group), performed three double-leg semisquat exercise trials with maximum hip adduction isometric contraction (DLSS-HA) and three double-leg semisquat exercise trials without hip adduction (DLSS). The normalized electromyographic muscle data were analysed using Repeated Measure ANOVA (p  0.05).

Results: The electrical activity of both VMO and VLL muscles was significantly greater during DLSS-HA exercise than during DLSS (p = 0.0002) for both groups. Additionally, an independent Repeated Measure ANOVA revealed that the electric activity of the VLL muscle was significantly greater (p = 0.0149) than that of the VMO muscle during DLSS exercises only for the PFPS group. However, no differences were found during DLSS-HA exercises.

Conclusions: Although there was no preferential VMO muscle activation, the association of hip adduction with squat exercise promoted a greater balance between the medial and lateral portions of the quadriceps femoris muscle and could be indicated for the conservatory treatment of PFPS patients. The association of isometric hip adduction with isometric semisquat exercises produced a more overall quadriceps activity and could be indicated for clinical rehabilitation or muscle strengthening programs.     

Polymorphic dinucleotide microsatellites for the Mediterranean angler species (Lophiidae)

A microsatellite‐enriched genomic library was obtained from black‐bellied angler Lophius budegassa and six polymorphic dinucleotide markers were successfully optimized. These markers showed levels of polymorphism ranging from 0.363 to 0.662 and allele numbers ranging from three to seven. These markers were also found to successfully amplify in the closely related Lophius piscatorius (angler) and thus appear to be useful for genetic stock structure analysis in both species.     

Improved preparation of anhydrous lanthanide chlorides under mild conditions

Oxides or carbonates of lanthanides (Ln) are converted under mild conditions into the corresponding solvated anhydrous chlorides LnCl₃(ether)_n by hydrogen chloride produced in situ from thionyl chloride and water in the presence of 1,l2-dimethoxyethane under mild conditions.     

Long-term vitamin E supplementation fails to reduce lipid peroxidation in people at cardiovascular risk: analysis of underlying factors

Background  

Antioxidant supplementation with vitamin E had no effect in the prevention of cardiovascular diseases (CVD) in three recent large, randomized clinical trials. In order to reassess critically the role of vitamin E in CVD prevention, it is important to establish whether these results are related to a lack of antioxidant action.     

Environmental heterogeneity shapes physiological traits in tropical direct‐developing frogs

1. Tropical ectotherm species tend to have narrower physiological limits than species from temperate areas. As a consequence, tropical species are considered highly vulnerable to climate change since minor temperature increases can push them beyond their physiological thermal tolerance. Differences in physiological tolerances can also be seen at finer evolutionary scales, such as among populations of ectotherm species along elevation gradients, highlighting the physiological sensitivity of such organisms.
2. Here, we analyze the influence of elevation and bioclimatic domains, defined by temperature and precipitation, on thermal sensitivities of a terrestrial direct‐developing frog (Craugastor loki) in a tropical gradient. We address the following questions: (a) Does preferred temperature vary with elevation and among bioclimatic domains? (b) Do thermal tolerance limits, that is, critical thermal maximum and critical thermal minimum vary with elevation and bioclimatic domains? and (c) Are populations from high elevations more vulnerable to climate warming?
3. We found that along an elevation gradient body temperature decreases as environmental temperature increases. The preferred temperature tends to moderately increase with elevation within the sampled bioclimatic domains. Our results indicate that the ideal thermal landscape for this species is located at midelevations, where the thermal accuracy (d_b) and thermal quality of the environment (d_e) are suitable. The critical thermal maximum is variable across elevations and among the bioclimatic domains, decreasing as elevation increases. Conversely, the critical thermal minimum is not as variable as the critical thermal maximum.
4. Populations from the lowlands may be more vulnerable to future increases in temperature. We highlight that the critical thermal maximum is related to high temperatures exhibited across the elevation gradient and within each bioclimatic domain; therefore, it is a response to high environmental temperatures.