Major Current Issue Research Articles

Prediction of drought regulating gene (s) in barley (Hordeum vulgare L.) using express sequence tags (ESTs) through in silico approaches

Climate change is a major current issue in the world, affecting the availability and stability of food. It leads to the most damaging abiotic stress for the ecosystem and the one that results in the greatest output loss is drought. Barley was once thought to be an abiotic stress-tolerant plant but the production of barley dropped significantly due to drought-stress. In this study, a computational method was used to predict the genes in barley that are associated with drought stress. The expressed sequence tags (ESTs) were investigated to identify the gene expression profiling in barley during drought stress. Various software, tools, and servers were used to predict the genes using ESTs, which were responsive to drought stress. The TFcat and blast2GO tools were used to predict transcription factors and enzymes respectively. Phytozome and plantCARE databases were used to validate newly predicted novel candidate genes using promoter studies. By using the Ensemble plant genome database, new genes related to drought stress were discovered. There were only 37 locations in the barley genome that had candidate genes. According to the promoter analysis, twenty nine genes had more than ten cis acting controlling elements that was related to drought stress in various plants. The promoter study showed that 29 out of 37 genes contained more than 10 cis-acting regulatory elements involved in drought stress in different plants. These findings will be helpful to identify the novel drought stress tolerant gene in barley that may play an important role in developing new varieties in near future.

Dynamics of retinal perfusion parameters in patients with post-COVID syndrome

BACKGROUND: A major current health issue is the rehabilitation of patients who previously had a coronavirus infection (COVID-19), as well as the treatment of patients with post-COVID syndrome. For a long time after COVID-19, patients may have complaints, including vision-related ones. One of the theories is that this may be due to long-term persistent microcirculatory retinal changes.
 AIM: To assess the long-term dynamics of retinal microcirculation changes in patients with post-COVID syndrome and to evaluate the relationship of these parameters with visual functions.
 MATERIALS AND METHODS: The main group consisting of 41 patients (82 eyes) was divided into groups depending on the severity of COVID-19: mild, moderate and severe. The control group included 13 people (26 eyes) who did not have COVID-19 to the time of the examination. All patients underwent an ophthalmological examination, including low-contrast visual acuity testing and optical coherence tomography-angiography. Vessel density (VD) was examined within the superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary capillaries (RPC). The following structural indicators were also measured: the retinal thickness, the retinal nerve fiber layer thickness and the ganglion cell complex. All patients were examined twice: 6 weeks after COVID-19 and in 27 weeks (6 months after the first visit).
 RESULTS: Patients who went through moderately severe and severe COVID-19 showed a significant decrease in low-contrast visual acuity in comparison to the control group at Visit 1 (p .001 in both cases), which totally recovered to the Visit 2. In the same group of patients, there was a significant decrease in VD SCP (p .001) and VD DCP (p .001) in comparison to the control group, and these parameters significantly decreased at visit 2 (p .001 in both cases). In the group of patients with moderate COVID-19, there was also a decrease in VD SCP and VD DCP in comparison to the control group (p .001 in both cases), while the indicators remained stable during 6 months of follow-up (p = .082). There were no significant changes in VD RPC and main morphometric parameters during 6 months of follow-up.
 CONCLUSIONS: In patients with COVID-19 from moderate severity to severe, there is a significant decrease in contrast sensitivity, which is temporary and fully recovers after 6 months. In patients with severe COVID-19, there was a negative dynamic of retinal perfusion during 6 months, both in deep and superficial capillary plexuses. Patients with post-COVID syndrome, or those who have had COVID-19 and present with visual complaints, need a deep ophthalmological examination including optical coherence tomography-angiography, with a possible involvement of related specialists.

Innovative integrated solar combined cycle: Enhancing dispatchability with a partial recuperative gas turbine and supercritical CO2 bottoming cycle, coupled with an ORC

Concentrating solar power is crucial in the future energy mix due to its ability to integrate thermal energy storage, thus providing dispatchability. One way to address the current high costs of this technology is by using higher temperatures, which can, however, lead to issues with heat transfer fluids and storage. A promising integrated solar combined cycle is here proposed to solve that current major issue. A partially recuperated gas turbine is coupled to a solar tower system using a Brayton supercritical CO2 power cycle, which recovers heat at two temperature levels. An Organic Rankine Cycle is also used to exploit the low-temperature flue gases. The performance at the design point is assessed under different solar contributions. The modulation of the thermal duty in the gas turbine recuperator allows reaching a nearly constant power production in the plant (180 MWe): 56 % coming from the gas turbine, 39 % from the CO2 power cycle, and 5 % from the ORC. The global efficiency achieved is 57.2 %. Carbon dioxide emissions range from 236 g CO2/kWhe (86 g CH4/kWhe are consumed) with the maximum solar contribution to 346 g CO2/kWhe (126 g CH4/kWh are consumed) with no solar contribution.

Research on the Practical Path of Common Prosperity in the Process of Chinese Modernization

Common prosperity is an important characteristic and core essential of Chinese modernization, and it is also the essential requirement of socialism. With the continuous advancement of Chinese modernization, how to achieve common prosperity has become the current major realistic issue. This article clarifies the dialectical relationship between Chinese modernization and common prosperity, and reviews the practical process of the Communist Party of China to promote common prosperity in the process of Chinese modernization. At the same time, Gangyao village of Yiwu City is selected as the research object, and the practical basis of promoting common prosperity in Gangyao village is discussed. Through the case analysis of Gangyao village, it is concluded that the practical path of promoting common prosperity is mainly the cooperation between villages and enterprises, the joint construction of agriculture, culture, tourism and the party, and the construction of spiritual and cultural life.

The influence of air pollution on gestational age at delivery and birthweight in patients with or without respiratory allergy: A nested case-control study.

Air pollution is a current major health issue. The burden of airborne pollutants and aeroallergen levels varies throughout the year, as well as their interaction and consequences. Prenatal exposure during pregnancy has been associated with adverse perinatal outcomes. The aim of this study was to evaluate the impact of air pollutants on perinatal outcomes in patients with or without respiratory allergy. Nested case-control retrospective study on 3006 pregnant women. Correlations between concentrations of common pollutants in each trimester of pregnancy and on average during the whole pregnancy and both gestational age at delivery and birthweight were studied. Pearson's correlation coefficient and binary logistic regression were used. In general, pollutants correlated more strongly with birthweight than with gestational age at delivery. Nine-month NO2 , SO2 , CO, and benzene, and second-trimester CO negatively correlated with birthweight, whereas only first-trimester NO2 showed a very mild correlation with gestational age at delivery. Negative correlations between pollutants and birthweight were much stronger in the respiratory allergy group (n = 43; 1.4%) than in the non-allergic group. After adjustments, the most significant predictive pollutant of birthweight was SO2 in both groups. The best predictive model was much stronger in the allergic group for third-trimester SO2 (R2 = 0.12, p = 0.02) than in the non-allergic group for total SO2 (R2 = 0.002, p = 0.02). For each unit that SO2 increased, birthweight reduced by 3.22% vs. 1.28% in each group, respectively. Air pollutant concentrations, especially SO2 , negatively influenced birthweight. The impact of this association was much stronger and more relevant in the group of women with respiratory allergies.

Multi-Criteria Optimization including Environmental Impacts of a Microwave-Assisted Extraction of Polyphenols and Comparison with an Ultrasound-Assisted Extraction Process.

Valorization of wastes and by-products using environmentally friendly technologies with an optimal cost-benefit relationship is a current major issue in agri-food industries. An original tool was recently developed for multi-criteria optimization of an ultrasound-assisted extraction (UAE) process including the assessment of environmental impacts using Life Cycle Assessment. In the present work, this methodology was adapted and applied to another green extraction process, microwave-assisted extraction (MAE), with the same case study, valorization of antioxidant polyphenols from downgraded beet seeds. Once built, the obtained multi-criteria optimization tool was used to investigate performances of the MAE process regarding productivity criteria (polyphenol concentration and antioxidant activity of the extracts), energy consumption and environmental impacts as functions of operating parameters (time, solvent composition, microwave power density, and liquid-solid ratio). The MAE process was optimized under different constraints and compared to the UAE process. For the studied conditions and different investigated scenarios, MAE enabled obtaining extracts with higher polyphenol concentrations and antioxidant activity (approximately 33% and 23% enhancements, respectively), and to strongly reduce extraction duration (by a factor up to 6), whereas UAE enabled reducing the energy consumption (up to 3.6 fold) and the environmental impacts (up to 12% for climate change).

Evaluation of anxiolytic activity of decoction of Parkia biglobosa in mice exposed to chronic immobilisation and physical activity test

Anxiety is a major current issue for both athletes and sedentary people. Several strategies for fighting this condition, aimed at limiting its sometimes adverse effects on the health and performance of athletes, are currently being developed. This study aims at assessing the combined effect of the decoction of dried Parkia biglobosa bark and aerobic physical activity in white mice. For this purpose, the elevated plus maze test (EPM) and the open field test were used. Thirty male and female mice of approximately eight weeks of age and 22 g body weight were used. They were divided into six groups of five mice each. This makes three test groups, one of which received the plant decoction by gavage and underwent anxiety induction; the other plant decoction and underwent anxiety induction and physical activity, and the third the anxiety induction and physical activity. A normal group received distilled water by gavage, a negative control group received distilled water by gavage and underwent anxiety induction and a positive control group received diazepam intraperitoneally and underwent anxiety induction. Thus, the results in the EPM give a significant difference (p˂0.001) in the open arms of the number of entries from 5 ± 1 in the negative control mice to 27 ± 2.54 in those treated with 56 mg/kg of the batch (Pb56+SIC+AP), the percentage of entries from 18.08 ± 4.54 in the negative control mice to 84.46 ± 2.57 in those treated with 56 mg/kg of the group (Pb56+SIC+AP). Then, the open field test showed a significant increase (p˂0.001) in the time spent in the centre from 6 ± 1second in the negative control mice to 42 ± 2 in those treated with 56 mg/kg of the group (Pb56+SIC+AP), in the number of crossing from 53 ± 4, 24 in the negative control mice to 101.8 ± 7.15 in those treated with 56 mg/kg of the group (Pb56+SIC+AP), the number of grooming from 2 ± 0.70 in the negative control mice to 11 ± 1.87 in those treated with 56 mg/kg of the batch (Pb56+SIC+AP). The decoction of dried barks of P. biglobosa combined with physical activity produces anxiolytic effects, that is, the ability to treat anxiety.

Development of Concrete Material Technology in the context of supply - demand based on geographical aspects

The Indonesian construction industry is one of the leading sectors with significant contributions to economic growth. A current major issue in the industry is to strive for sustainable development focuses on three aspects, social, environmental, and economical. The use of technology, especially concrete material technology, is one of the supporting factors to achieve the goal. Concrete material usage, with cement as the main component, is quite prominent in the industry, supported by Indonesia’s top 12th cement producer globally with a 2,05% contribution of the world’s total cement production. However, the industry performance in each part of Indonesia also needs to be observed, considering that Indonesia has numerous islands. This study aims to evaluate the landscape of technological development of construction material regarding the supply-demand from geographical dimensions. This supply-demand analysis can consider policy strategies to support sustainable development programs. The data used in this study are derived from the production and consumption aspects of concrete material with an economic approach. The study shows the relationship between the development of concrete construction technology in terms of supply and market conditions. In addition, this study discusses the sustainable aspect of concrete material technology in the context of the trend of cement usage.

Metal precursors from eggshells wastes for the production of calcium–organic frameworks and their use in accelerating the formation of carbon–carbon bonds

The current study's major issue is the transition from trash to value-added products. Eggshell waste is one of the most typical byproducts of food manufacturing. Eggshell is a calcium-rich material that can be used as an economical supply of Ca2+ for the construction of Ca-BTC MOFs. The catalytic impact of an eggshell-based metal-organic framework was explored in the Knoevenagel condensation reaction. To find the best condensation reaction setup, we looked at the effects of different solvents, such as ethanol, ethyl acetate, and toluene, as well as the effects of different temperatures, such as 30–80 °C, and different dosages of Calcium-BTC. Ca-BTC's recoverability, reusability, and durability were also confirmed under optimal conditions. Ca-BTC's catalytic performance in the Knoevenagel reaction for condensing various aldehydes with malononitrile derivatives yielded benzylidenemalononitrile with yields up to 99% in a relatively short period under ecologically friendly settings.

Overview of the microbiota in the gut-liver axis in viral B and C hepatitis.

Viral B and C hepatitis are a major current health issue, both diseases having a chronic damaging effect on the liver and its functions. Chronic liver disease can lead to even more severe and life-threatening conditions, such as liver cirrhosis and hepatocellular carcinoma. Recent years have uncovered an important interplay between the liver and the gut microbiome: the gut-liver axis. Hepatitis B and C infections often cause alterations in the gut microbiota by lowering the levels of ‘protective’ gut microorganisms and, by doing so, hinder the microbiota ability to boost the immune response. Treatments aimed at restoring the gut microbiota balance may provide a valuable addition to current practice therapies and may help limit the chronic changes observed in the liver of hepatitis B and C patients. This review aims to summarize the current knowledge on the anato-functional axis between the gut and liver and to highlight the influence that hepatitis B and C viruses have on the microbiota balance, as well as the influence of treatments aimed at restoring the gut microbiota on infected livers and disease progression.

Vaccination after prior COVID-19 infection: Implications for dose sparing and booster shots.

Vaccination after prior COVID-19 infection: Implications for dose sparing and booster shots.

U- and Th- series disequilibria in separated soil mineral fractions: Insight into the mechanism and timescale of U, Th and Ra redistribution

In recent decades, U- and Th- series nuclides have been successfully used to determine weathering rates in soils and regoliths. However, the redistribution of the nuclides within secondary minerals and/or organic matter may interfere with the recorded U- and Th-series weathering signals and can result in inaccurate and/or poorly constrained weathering rate determinations. In addition, the migration of radionuclides in the environment represents a major current issue. The objective of this study, therefore, was to evaluate the meaning of bulk soil data for weathering investigations and to assess the processes and timescales of U, Th and Ra redistribution in a forested-soil profile, both at the bulk soil scale level and for separated mineral fractions. This study was carried out at the INRAE-Andra experimental beech-forested site of Montiers (Meuse, France), which was developed on acidic detrital sediments inherited from tropical paleosoils erosion. U- and Th-series activity nuclides were measured in bulk soil samples and in separated Fe nodules and clay-size (<2 μm) fractions. Furthermore, the analyses of atmospheric particles allow discussing the potential influence of atmospheric inputs.While bulk soil disequilibria suggested negligible to moderate mobility of the nuclides, an important transfer between mineral fractions was highlighted; this resulted in contrasting redistributions of U, Th and Ra within soil fractions. Fe-oxide nodules controlled the overall mobility of U on the bulk soil scale, while the fine <2 μm fraction controlled the mobility of Ra. A capture of 234U by Fe-oxide nodules (mainly comprised of goethite) was observed within the entire soil profile, most likely occurring for several hundred ky. In the shallow soil layers, a leaching of U from the <2 μm fraction that was not re-adsorbed onto Fe-oxides occurred. In contrast, Fe-oxides appeared to retain all U mobilized from the <2 μm fraction in the deep soil layers, resulting in negligible U mobility and an apparent “closed-system” at the bulk soil scale. This transfer, however, seemed to occur over shorter timescale than the one in the shallowest soil layers. No mobility of 226Ra was observed at the bulk soil scale, despite the large release of this nuclide from Fe-oxides. The measured (210Pb/226Ra) activity ratios suggested that up to 50% of 226Ra in Fe-oxides is available for desorption. However, the <2 μm fraction strongly readsorbed the released Ra and prevented the loss of this nuclide at the bulk soil scale. Considering the short half-life of 226Ra, such transfer from Fe-oxides to the <2 μm fraction occurred over a significantly shorter timescale than U mobilization. In addition, the analysis of the short-lived 228Ra isotope emphasized the flux involved in the biological cycle and the potential impact of vegetation on the soil radionuclide redistribution over a short timescale.Our results suggest that the fine <2 μm fractions might be suitable for probing the residence time of clay minerals in soils by the U-series dating method, if the soil profile can be assumed to consist of homogenous inherited clays.

Biosafety evaluation and detection of shrimp viruses on field samples using dual priming oligonucleotide (DPO) system based multiplex PCR assay

Disease is the current major challenge and issue in shrimp aquaculture as it can be spread easily causing global outbreak. The risk of disease outbreak in shrimp populations can be further minimized with rapid and accurate diagnostic method. This study aims to develop a dual priming oligonucleotide (DPO) based multiplex PCR system for simultaneous detection of shrimp DNA and RNA viruses. This system targets Baculovirus Penaei (BP), Monodon Baculovirus (MB), Infectious Hypodermal, Haematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV), Macrobrachium rosenbergii nodavirus (MrNV), Infectious Myonecrosis Virus (IMNV), Taura Syndrome Virus (TSV) and Yellow Head Virus (YHV). The shrimp samples collected from shrimp farm were diagnosed to be infected with YHV infection in the 2nd cycle in year 2018 with 80% screening rate (4/5). DPO based multiplex PCR system may facilitate the rapid and effective screening of shrimp viruses in laboratory.

From haematopoietic stem cell harvest to post-transplant

Allogeneic stem cell transplant, used for the first time in 1950s, is the older immunotherapy which can be able to cure malignant hematologic diseases. Indications are becoming larger thanks to supportive care progress and larger donor availability, in particular with haplo-identical donors. Graft versus host disease and infections remain the main complications at the origin of high morbi-mortality (treatment-related mortality of 15 to 25%). Current major issue is to limit post-allogeneic relapse, especially thanks to targeted therapies and immunotherapy.

Manipulation of Bio-nanotechnology in Agri-Sector for Pest Control with Special Emphasis to Nematode Problems in Egypt

With the extravagant increase in the population and the increasing need for food, space and desert development, especially for agricultural expansion, has become a strategic goal and the focus of the economic and social policies of Egypt. The coming decades will witness accelerated rates of development in desert agriculture, not only through expanding beyond the green boundaries of the delta and the Nile valley , but also by crossing to remote areas in Sinai , southern Egypt. Soil nematode infecting plants are one of the most destructive parasites worldwide and cause crop damages with wide host rang. Attacking plant root system and feed on the plant nutrients causing lose in the crop yield and even death of the plants by developing galls and necrosis in the root system losing the ability of absorb the nutrients, water and die. The current major issue concerning nematode damage to plants is the lack of effective chemical treatment methods. The public concern over the chemical Nematicides is not only their toxicity for health and environmental risks but also their loss of efficiency after prolonged use. Several control strategies alternative to chemical control that develops recently is production of natural Bio-Nano Nematicides as (green chemical) which act as inhibitors against nematodes population in soil. The Advantages of using bionano Nematicides, it's safe organic compound extracted from the plant, It has no residual effect, It gives high ability to reach within the roots to combat nematodes in their phases, and the ability of the compound to rapidly spread in irrigation water which also gives the strength to spread and stay in the soil for a long time. The nematicides caused direct death to nematodes after few minutes when exposed to low concentrations, also has a repellent effect due to the presence of nanoparticles around the roots, the penetration of nanoparticles inside the root causes the inability of nematodes to form the nourishing cells and are therefore destroyed. It was also found out that there are more than 800 products as fertilizers in the world with their effective as nanomaterials, it is used for sprinkling on the vegetable, which will benefit the plant faster by Increasing photodynamic activity also increasing leaf content of chlorophyll. Also that product Increase crop capacity to withstand different stress conditions, Absorption speed, and Only 1 kg of nanophosphate fertilizer is required to replace 150 to 200 kg of superphosphate fertilizer in citrus farms. For example, Nanomaterials help protect the environment and human health, Increases farm profitability due to reduced fertilizer and spraying costs. Finally Advantage of using Bio-nanotechnology application in agriculture is seriously contributes effectively to increase the productivity of crops, Increase the quality of fruits, Increase their competitiveness by reducing the residues of fertilizers, Preserves the soil and reduces the contamination of groundwater with the residues of different fertilizers, Economically reflected on the economic yield of the farmer through the reduction of expenses, and thus increase the profitability of different crops, and increase export opportunities through increased product competitiveness . More over the Development of the new generation of highly specialized biocides, overcoming the problems of global warming and its impact on the growth of plants to produce plants that tolerate high temperatures.

Acoustic Study of Noise Generated by Arzew's Industrial Units in Limited Batteries

This study carried out concerns noise pollution from the Arzew industrial zone. Currently, noise is an integral part of our environment and represents a major current issue, due to its dangerous health effect. Due to the proximity between industrial sites and residential areas, which very often generates noise-related conflicts that require the intervention of an acoustic expert to resolve and protect the neighbourhood from noise exposure from the complexes in the Arzew industrial zone. We have dedicated our work to the assessment of noise emissions generated by several oil and gas plants located in the ARZEW industrial zone and to the verification of the application of laws relating to the limitation of noise levels emitted into the environment by the various facilities. We focused our study on noise measurements in the periphery of the plants, known as the "property limit", also known as the "battery limit".

Design of New Amines of Low Toxicity for Efficient Free Radical Polymerization under Air

AbstractTwo new amines are proposed here as a new class of high performance coinitiators for camphorquinone (CQ)‐based systems for mild polymerizations of methacrylates under blue light irradiation (LED@477 nm). These new compounds are very interesting because they are much less toxic than commonly used amines such as ethyl 4‐(dimethylamino) benzoate or 4‐(dimethylamino) benzonitrile. The particularity of one of these two new amines is its dual role: it is a coinitiator and contains a copolymerizable group. Therefore, it is much less subject to migration or leaching, which is a major current issue of polymers. Excellent polymerization performances in the presence of CQ for the free radical polymerization of methacrylates under blue light irradiation and under air are observed. Remarkably, good bleaching properties are obtained after polymerization.

Assessing Perception of Climate Change by Representatives of Public Authorities and Designing Coastal Climate Services: Lessons Learnt From French Polynesia

Institutional actors have a crucial role in adaptation to climate change, especially for highly vulnerable territories such as small tropical islands. Here, we emphasize their major role in the co-design of tailored coastal climate services based on a case study of French Polynesia. In this perspective, we assessed climate change perceptions by public authorities and identified their needs with regard to climate-related science. This assessment included an analysis of the decision-making context, semi-structured interviews with practitioners representing 23 administrative divisions directly or indirectly involved in climate change issues, and a workshop dedicated to discussing needs in terms of coastal climate services. Generally, respondents did not identify climate change as a major current issue in French Polynesia; they showed more concern for economic growth, pollution, land tenure, and land use planning. However, interviewees were concerned about future impacts of sea-level rise (SLR) and ocean warming and acidification, mentioning in particular their detrimental impacts on marine ecosystems, shoreline position, economy (especially agriculture and the blue economy), and freshwater resources. The interviewed practitioners showed particular interest in SLR projections for future decades up to a century, and for knowledge on expected impacts to critical infrastructure, coastal systems, and natural resources. Practitioners’ needs made it possible to co-define four coastal climate services to be developed: (1) the design of sea-level-rise-compatible critical infrastructures (airports and ports); (2) adapting to the risk of destabilization of beaches and reef islands; (3) professional training on climate change impacts and adaptation, including an analysis of potentially emerging new jobs in the SLR context; and (4) the development of participatory approaches for observing climate change impacts. While the co-development of these coastal climate services will require a multi-year engagement of stakeholders concerned with climate change adaptation, our results already shed light on specific needs for salient coastal climate services in highly vulnerable tropical island territories.

Production of Mannosylerythritol Lipids (MELs) to be Used as Antimicrobial Agents Against S. aureus ATCC 6538

Antimicrobial resistance (AMR) is a current major health issue, both for the high rates of resistance observed in bacteria that cause common infections and for the complexity of the consequences of AMR. Pathogens like Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Mycobacterium tuberculosis among others are clear examples of antibiotic-resistant threats. Biosurfactants have recently emerged as a potential new generation of anti-adhesive and anti-biofilm agents; mannosylerythritol lipids (MELs) are biosurfactants produced by a range of fungi. A range of structural variants of MELs can be formed and the proportion of each isomer in the fermentation depends on the yeast used, the carbon substrate used for growth and the duration of the fermentation. In order to allow assessment of the possible functions of MELs as antimicrobial molecules, small quantities of MEL were produced by controlled fermentation. Fermentations of the yeast Pseudozyma aphidis using rapeseed oil as a carbon source yielded up to 165 gMELs/kgSubstrate. The MELs formed by this strain was a mixture of MEL-A, MEL-B, MEL-C and MEL-D. The MELs produced were tested against S. aureus ATCC 6538 on pre-formed biofilm and on co-incubation biofilm experiments on silicone discs; showing a disruption of biomass, reduction of the biofilm metabolic activity and a bacteriostatic/bactericidal effect confirmed by a release of oxygen uptake p_{{{text{O}}_{2} }}, the reduction of citrate synthase activity and scanning electron microscopy. The results show that MELs are promising antimicrobial molecules for biomedical technological applications that could be studied in detail in large-scale systems and in conjunction with animal tissue models.

Introducing sequential aza-amino acids units induces repeated β-turns and helical conformations in peptides.

A major current issue in medicinal chemistry is the design of small peptide analogues resistant to proteolysis and able to adopt preferential conformations, while preserving the selectivity and efficiency of natural peptides. Whereas the introduction of one aza-Gly in peptides has proven numerous biological and structural interest, the conformational effect of sequential aza-Gly or aza-amino acids bearing side chains has not been investigated. In this work, experimental NMR and X-ray data together with in silico conformational studies reveal that the introduction of two consecutive aza-amino acids in pseudotripeptides induces the formation of stable hydrogen-bonded β-turn structures. Notably, this stabilization effect relies on the presence of side chains on aza-amino acids, as more flexible conformations are observed with aza-Gly residues. Remarkably, a longer aza/aza/α/aza/aza/α pseudohexapeptide containing substituted aza-amino acids adopts repeated β-turns conformations which interconvert with a fully helical structure mimicking a 310 helix.