Alzheimer Disease and Acetylcholinesterase Inhibitors

Alzheimer\u27s disease (AD) or Alzheimer\u27s is a is a chronic neurodegenerative disorder. It\u27s characterized by loss of neurons and synapses in the cerebral cortex and certain subcortical regions. AD patients are identified by problems with memory and language, getting lost and desorientation. AD affects about 6% of people 65 years and older but 4% to 5% of cases are younger.1 It is one of the most costly diseases in the world. In 2015, there were about 48 million people worldwide with AD. To prevent AD, intellectual activities such as reading and playing chess are recommended. In muslim countries, learning quran is linked to a reduced risk of AD. The cause for most Alzheimer\u27s cases is still mostly unknown except for 1% to 5% of cases linked to genetic factors AD has been identified as a protein misfolding disease (proteopathy), caused by plaque accumulation of abnormally folded amyloid beta protein in the brain.2 However, there is another hypothesis which proposes that AD is caused by reduced synthesis of the neurotransmitter acetylcholine.3 The enzyme Acetylcholinesterase breaks acetylcholine down after acetylcholine is used in the brain. Galanthamine, a natural product isolated from Galanthus nivalis, G. woronowii and some other Amaryllidaceae plants and rivastigmine which is a natural derived compound and Donepezil which is a synthetic compound are used as cholinesterase inhibitors. Polyphenols which have been shown to possess antioxidant activity are the principal constituants of the mediterranean diet which is known to decrease the risk of AD. Antioxidants may slow the progression of AD and minimise neuronal degeneration.4 The compounds that exhibit anticholinesterase activity are also related to radical scavenging activity.5 Polyphenols and terpenoids from Lamiaceae plants possess antioxidant and anticholinesterase activitie

ANTIOXIDANT AND THE IMMUNOMODULATORY ACTIVITIES EXHIBITED BY THREE PLANTS FROM LAMIACEAE FAMILY

Objective: The aim of this work was screening of the antioxidant activity and immunomodulatory effects of the crude extracts from the aerial parts of three Algerian endemic species from Lamiaceae.Methods: DPPH radical scavenging assay was used to find the antioxidant activity of Stachys circinata, Salvia verbenaca and Thymus guyonii and the immunostimulant potential of these plants extracts on the phagocytic activity which was measured by the carbon clearance rate test.Results: Our results obtained in this study shown that the IC50 of Thymus guyonii, Salvia verbenaca and Stachys circinata were 15,90;47,50 and 54,92 respectively. The phagocytic index was increased significantly in animals injected with Stachys circinata and Salvia verbenaca at doses of 200 mg/kg P≤0,05 but not significantly with Thymus guyonii when compared to the control group. The clearance rate of carbon was faster but not significantly P≥ 0,05 and the corrected phagocytic index α was increased at the group GIII with Salvia verbenaca but not significantly when compared with other groups P≥ 0,05.Conclusion: The Stachys circinata and Salvia verbenaca extracts proved an immune-stimulatory effect on the reticuloendothelial system and Thymus guyonii extract revealed anti-oxidant activity.Â

Effect of Argania spinosa oil extract on proliferation and Notch1 and ERK1/2 signaling of T-cell acute lymphoblastic leukemia cell lines

The Argan tree, called Argania spinosa (L.) Skeels, is a tropical plant, which belongs to the Sapotaceae family, it is exploited essentially for its fruits. The endosperm seed of the fruit constitutes a good potential source of edible oil for human consumption and is endowed with important medicinal properties such as antioxidant, antimalarial and anti-proliferative. The aim of the present work is to evaluate the anti-proliferative effect of the oil extracted from seeds of A. spinosa in T-cell acute lymphoblastic leukemia human (T-ALL) context. The activity was assessed through an in vitro test on three T-ALL cell lines: JURKAT, MOLT3 and DND41. The cytotoxicity effects of A. spinosa oil extract were checked by MTT assay and the change in the activity levels of two T-ALL proliferation-related proteins (Notch1 and ERK) was investigated by Western blot, the results demonstrate that treatment with A. spinosa oil extract at the dose of 100 μg/mL inhibited the growth of JURKAT, MOLT3 and DND41 cells, and reduced the expression levels and the activity of proliferation-related proteins such as ERK1/2 and Notch1 intracellular domain. A. spinosa oil extract could be a potential preventive and therapeutic approach recommended as anti-proliferative against leukemia

COMPARATIVE COMPOSITIONS AND ANTIBACTERIAL ACTIVITY OF THE ESSENTIAL OILS OF ANTHEMIS NOBILIS L. AND ANTHEMIS MIXTA L. (ASTERACEAE)

Objective: To evaluate the chemical composition of essential oils from aerial parts of Anthemis nobilis (An) and Anthemis mixta L (Am). and investigate their antibacterial property.Methods: The essential oils were isolated by hydro distillation and analyzed by GC and GC-MS. The disc diffusion and Agar dilution methods were used to screen the antibacterial activity against referenced and/or clinically isolated (HS) strains of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enterica, Klebsiella pneumonia and Shighuelle sonnei.Results: The main constituents of An essential oil were 3-methyl-2-buten-1-yl cyclopropane carboxylate (29.3%), vinyl-2,2-dimethylbutanoate (24.2%), glycidyl methacrylate (9.9%), 2-methylbutyl-2-mehylbutyrate (9.1%), isobutyl isobutyrate (7.8%) and 3,3,4-trimethylhexane (6.2%), while Am essential oil was mainly characterized by α-thujone (51.8%), β-thujone (14.6%), borneol (7.3%) and 3-hexen-1-ol (4.9%). An and Am essential oils exhibited the best antibacterial activity against the following strains of Escherichia coli ATCC 25922 (25±1.20, 32±1.00 mm), Pseudomonas aeruginosa ATCC 27853 (23±0.87, 32±0.76 mm) and Staphylococcus aureus ATCC 43300 (21±1.44, 25±1.24 mm inhibition zone diameters, respectively). Minimum inhibitory concentration (MICs) values of these oils were ranged from 32-128µg/ml.Conclusion: From this study, it can be concluded that the chemical composition of the essential oils was related to their antibacterial activity.Keywords: Anthemis nobilis L., Anthemis mixta L., Chemical composition, Antibacterial activit

Scaling of AlN/GaN HEMT for millimeter-wave power applications

International audienceIn this paper, we report on AlN/GaN HEMTs for high frequency applications. Various gate lengths have been studied as a function of the gate-drain distance in order to analyze the impact on the DC, RF and power performances. Electrical characteristics of this structure for 110 nm gate length show a maximum drain current of 1.2 A/mm, an extrinsic transconductance Gm of 400 mS/mm and a FT/Fmax of 63/300 GHz at a drain bias voltage VDS = 20V. An excellent electron confinement with a low leakage current below 10 µA/mm is achieved. Furthermore, a breakdown voltage of 55 V for GD0.5 and up to 140 V for GD2.5 are observed when using a 110 nm short gate length. Large signal characteristics at 40 GHz reveal a state-of-the-art combination of power added efficiency (PAE) (50%) with an output power density (Pout) of 3.6 W/mm at VDS = 20 V in continuous wave mode (CW) and PAE of 50% associated with a Pout of 8.3 W/mm at 40V in pulsed mode. It can be noticed that the 110 nm gate length GD0.5 showed no degradation after semi-on robustness tests and large signal measurements up-to VDS = 20V

Proteomic analysis of sweet algerian apricot kernels ( Prunus armeniaca L.) by combinatorial peptide ligand libraries and LC-MS/MS

An investigation on the proteome of the sweet kernel of apricot, based on equalisation with combinatorial peptide ligand libraries (CPLLs), SDS-PAGE, nLC-ESI-MS/MS, and database search, permitted identifying 175 proteins. Gene ontology analysis indicated that their main molecular functions are in nucleotide binding (20.9 %), hydrolase activities (10.6 %), kinase activities (7 %), and catalytic activity (5.6%). A protein-protein association network analysis using STRING software permitted to build an interactomic map of all detected proteins, characterised by 34 interactions. In order to forecast the potential health benefits deriving from the consumption of these proteins, the two most abundant, i.e. Prunin 1 and 2, were enzymatically digested in silico predicting 10 and 14 peptides, respectively. Searching their sequences in the database BIOPEP, it was possible to suggest a variety of bioactivities, including dipeptidyl peptidase-IV (DPP-IV) and angiotensin converting enzyme I (ACE) inhibition, glucose uptake stimulation and antioxidant properties

Demonstration of GaN-on-silicon material system operating up to 3 kilovolts with reduced trapping effects

International audienceWe report on the first demonstration of low trapping effects up to 3000 V within GaN-on-silicon epitaxial layers using a local substrate removal (LSR) followed by a thick backside ultra-wide-bandgap AlN deposition. The fabricated AlGaN/GaN devices deliver low specific on-resistance below 10 mΩcm 2 together with unprecedented 3-terminal blocking voltage while substrate ramp measurements show reduced hysteresis up to 3000 V. These results pave the way for beyond 1200 V applications using large wafer diameter GaN-on-Si high electron mobility transistors

Sens et conscience de la recherche urbaine

La question que nous nous sommes posée nous a longtemps interdit de rédiger quelques lignes que ce soit sur Rachel. Comment en effet parler de quelqu’un qui fut à la fois une élève, une amie et dont la complicité ne s’est jamais démentie pendant de très longues années, même si les chemins de la vie nous ont souvent séparés ? Il est vrai que la souffrance de la perte n’aide guère à penser autrement qu’en termes de compassion, de mots et complaintes dont on peut aisément décrire les dimensions ..

DEVELOPMENT OF SETUP FOR ON-WAFER PULSE-TO-PULSE STABILITY CHARACTERIZATION OF GAN HEMT TRANSISTOR IN KU-BAND

International audienceWe report on the development of a test bench to extract pulse-to-pulse (P2P) stability On-Wafer in Ku-band. The P2P stability is crucial for RADAR performances. GaN HEMT transistors are a promising candidate for RADAR application. However, they typically generate trapping effects, which can strongly affect the P2P stability. Two methods RMS and Standard Deviation based on temporal analysis are employed to extract the stability indicators. The main idea of the P2P test bench is the use of a homodyne demodulation to recover the envelop of the RF. This setup is also combined to an active load pull towards P2P stability test bench dedicated to the new generation of GaN HEMT transistors in large signal condition close to their operational mode

GaN-based transistors using buffer-free heterostructures for next generation RF devices

International audienc