Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure

Five-day exposure of clary sage (Salvia sclarea L.) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (Φ_PSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (Φ_NO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (¹O₂) formation. A basal ROS level was detected in control plant leaves for optimal growth, while a low increased level of ROS under 5 days Cd exposure seemed to be beneficial for triggering defense responses, and a high level of ROS out of the boundaries (8 days Cd exposure), was harmful to plants. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered. However, exposure to a combination of Cd and high light or to Cd alone (8 days) resulted in an inhibition of PSII functionality, indicating Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposure and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of “adaptive response” and “toxicity”, respectively.     

On the Distortion and Warpage of 7249 Aluminum Alloy After Quenching and Machining

The objective of this study is to determine the effect of solution treatment temperature, quenching media, and various machining sequences on the warpage behavior of aluminum 7249 alloy aged to T6 and T7′ tempers. Large extrusions of 7249 aluminum alloy with fins were cut into 108 “T” sections. The samples were solution-treated, aged, and machined. Three solution temperatures (445, 474, and 505 °C), two quenching media (water and 20% polyalkylene glycol), two aging treatments (T6 and T7′), and three machine sequences were used. The flatness of the samples was measured on the surfaces orthogonal to the z-axis. Three points were on top of both shoulders (six total), six were at the bottom of the sample, and six were on the top of the fin, in the cases where the fin was not milled off. They were then averaged together by surface to represent the overall warpage of each sample.     

Case study of the impact of toecap type on the microclimate in protective footwear

Protective footwear plays a critical role in work effectiveness and personal safety. It exhibits special properties due to the use of protective elements and materials, but these components may deteriorate its hygienic characteristics. This paper presents a study on the influence of toecap type on the microclimate in protective footwear (ankle boots). Toecaps made of metal and of a composite polymer material were evaluated. Changes in the footwear microclimate were monitored using a thermal foot model at a perspiration rate of about 5 g/h with and without the simulated movement function. The influence of the toecap material on the microclimate in the footwear was analyzed statistically. Under conditions of simulated movement, higher temperature and relative humidity values (about 32 °C and 90%) were recorded in the toe region of ankle boots with metal toecaps as compared to composite polymer toecaps (about 29 °C and 53%, respectively). These results suggest that protective footwear with composite toecaps ensures better ventilation of the foot during work.     

Cleaner production in Romanian textile industry: a case study

This paper reports the changes resulting from adopting environmentally sensitive criteria in Novatextile Pitesti, Romania. The changes have improved the operation of the production plant and reduced costs at the same time.     

Direct Ink Writing of a Preceramic Polymer and Fillers to Produce Hardystonite (Ca2ZnSi2O7) Bioceramic Scaffolds

The direct ink writing of an ink composed of a preceramic polymer and fillers was used to produce hardystonite (Ca₂ZnSi₂O₇) bioceramic scaffolds. Suitable formulations were developed for the extrusion of fine filaments (350 μm diameter) through a nozzle. The preceramic polymer was employed with the double purpose of contributing to the rheology of the ink by increasing its viscosity and of forming the hardystonite phase upon heat treatment by reacting with the fillers. A control of the rheology is essential when spanning features have to be produced, and therefore the main rheological characteristics of the inks were measured (flow curves, dynamic oscillation tests, viscosity recovery tests) and compared to models reported in the literature. Highly porous scaffolds (up to 80% total porosity) were produced and heat treated in air or in nitrogen atmosphere. The influence of the heat‐treatment atmosphere on the morphology, crystalline phase assemblage, and compressive strength of the scaffolds was investigated.     

Influence of macromolecular structure of novel 2- and 4-armed polylactides on their physicochemical properties and in vitro degradation process

The objective of this study was to analyse how macromolecular structure of polylactides influences their properties and degradation rate. To achieve this, novel 2- and 4-armed PDLLA and PLLA (noted as 2b and 4b) were synthesized by ring-opening method. 1,4-butanediol and pentaerythritol were used as initiators and stannous octoate was used as catalyst. The obtained polymers were investigated in terms of molecular weight by size exclusion chromatography, thermal properties by differential scanning calorimetry and thermogravimetry, and hydrophilicity by the contact angle measurements. The in vitro degradation test was carried out in PBS solution at 37 °C by means of the mass loss, water uptake, molecular weight and thermal properties changes. The branched polylactides including 2bPDLLA, 4bPDLLA, 2bPLLA and 4bPLLA were successfully synthesized and the average molecular weights were around 40-45 kDa. The numbers of arms in each polymer just slightly influenced the thermal properties and the contact angle. The crystallinity of 4bPLLA was 23 %, whereas for 2bPLLA it was 41 %. The degradation rates of both 2b and 4bPLLA were similar and the degradation process was similar only during first 7 weeks. After this period, the degradation rate of 4bPDLLA increased. Consequently, thermal properties and degradation profiles of the branched polymers would depend on plural factors, such as chain length and crystallinity in branched structure.     

Effect of cooking and germination on phenolic composition and biological properties of dark beans (Phaseolus vulgaris L.)

Legumes are the base´s diet in several countries. They hold a high nutritional value, but other properties related to human health are nowadays being studied. The aim of this work was to study the influence of processes (boiling or germination) on the phenolic composition of dark beans (Phaseolus vulgaris L. c.v. Tolosana) and their effect on their antioxidant, neuroprotective and anticancer ability. Phenolic composition of raw and processed dark beans was analysed by HPLC-PAD and HPLC–ESI/MS. The antioxidant activity was evaluated by ORAC. Astrocytes cultures (U-373) have been used to test their neuroprotective effect. Anticancer activities were evaluated on three different cell lines (renal adenocarcinoma (TK-10), breast adenocarcinoma (MCF-7) and melanoma (UACC-62)) by sulphorhodamine B method. Qualitative and quantitative differences in phenolic composition have been observed between raw and processed dark beans that influence the antioxidant activity, mainly for germinated samples which show a decrease of antioxidant capacity. Although every assayed extracts decreased reactive oxygen species release and exhibited cytotoxicity activities on cancer cell lines, raw beans proved to be the most active in neuroprotective and antitumoral effects; this sample is especially rich in phenolic compounds, mainly anthocyanins. This study further demonstrated that phenolic composition of dark beans is related with cooking process and so with their neuroprotective and anticancer activity; cooking of dark beans improves their digestion and absorption at intestinal level, while maintaining its protective ability on oxidative process at cellular level.     

In-stream energy converters in a river – Effects on upstream hydropower station

The use of in-stream energy converters in rivers is an area of research that is still in its preliminary stages. The driving force of river flows is the potential energy the water gains when it precipitates on mountainsides, and this energy is traditionally converted by hydropower stations, where dams are used to create a larger head. Using an in-stream energy converter would be advantageous in areas restricted by regulation. In this paper the effects of using these converters on the upstream water level in a river are studied. This has been done both with an analytical model and with a numerical model. The analytical model described the water level increase due to energy capture to depend on how large fraction of the channel that is blocked by the turbine. It was also shown that as the converter induces drag on the flow, and as energy is lost in wake mixing, the total head loss will be a sum of energy capture and energy losses. The losses correspond to a considerable fraction of the total head drop. The numerical model was used to evaluate these results. The model used was the 3D numerical model MIKE from the DHI Group in Sweden. Turbines were modelled with an inbuilt function in the program. The results from the model did not correspond to the analytical results, as the energy capture was equal to the head drop in the program.     

Comparative exergy analysis of direct alcohol fuel cells using fuel mixtures

Within the last years there has been increasing interest in direct liquid fuel cells as power sources for portable devices and, in the future, power plants for electric vehicles and other transport media as ships will join those applications. Methanol is considerably more convenient and easy to use than gaseous hydrogen and a considerable work is devoted to the development of direct methanol fuel cells. But ethanol has much lower toxicity and from an ecological viewpoint ethanol is exceptional among all other types of fuel as is the only chemical fuel in renewable supply. The aim of this study is to investigate the possibility of using direct alcohol fuel cells fed with alcohol mixtures. For this purpose, a comparative exergy analysis of a direct alcohol fuel cell fed with alcohol mixtures against the same fuel cell fed with single alcohols is performed. The exergetic efficiency and the exergy loss and destruction are calculated and compared in each case. When alcohol mixtures are fed to the fuel cell, the contribution of each fuel to the fuel cell performance is weighted attending to their relative proportion in the aqueous solution. The optimum alcohol composition for methanol/ethanol mixtures has been determined.     

Neuroprotective properties of Spanish red wine and its isolated polyphenols on astrocytes

The neuroprotective effect of Merlot red wine and its isolated polyphenols was evaluated in an oxidative stress model induced by Fenton reaction and hydrogen peroxide in the human astrocytoma U373 MG cell line. Compared with cells treated only with oxidative stress inductors, the pre-incubation with Merlot red wine for 24 h caused a significant increase in cell viability for all concentrations assayed. The most abundant polyphenols found in Merlot red wine were the flavonoids catechin (37.8 mg/l), epicatechin (52.3 mg/l), quercetin (5.89 mg/l) and procyanidins (15.2 mg/l), the hydroxybenzoic acid gallic acid (16.7 mg/l), and the phenolic alcohol tyrosol (31.4 mg/l). The potential protective role of these polyphenols when isolated was then assessed in treated Fenton reaction U373 MG cells. Polyphenols decreased reactive oxygen species generation and increased the activity and the protein expression of the antioxidant enzymes catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase. Of the polyphenols, quercetin and procyanidins showed the highest neuroprotective effect.