In vitro alteration of artemisinin biosynthesis in Artemisia annua L during treatment with methyl jasmonate

Purpose: To investigate the in vitro effect of methyl jasmonate (MeJA) on artemisinin biosynthesis in Artemisia annua.Method: The effect of two concentrations of MeJA i.e. 2 μm (T2) and 5 μm (T5) on biomass, plant height and artemisinin content of Artemisia annua L. was investigated in vitro in MS medium.Results: Plant height (6.5 ± 1.8 cm), biomass (0.18 ± 0.02 g/plant) and artemisinin content (0.035 ± 0.002 % dry weight) were higher in T5 and T2 treatment groups than in non-treated control plants (C). Artemisinin content, biomass and plant height were positively correlated after 2 - 8 days of treatment, but remained unchanged on the 12th day of treatment.Conclusion: The observed effects of exogenous MeJA on the biosynthesis of artemisinin and other secondary metabolites may lead to elucidation of promising targets for further studies on metabolic engineering of Artemisia annua L. Keywords: Artemisia annua L. Methyl jasmonate, HPLC, Artemisini

Effect of rapid thermal annealing on the electrical properties of dilute GaAsPN based diodes

© 2019 IOP Publishing Ltd. The effect of rapid thermal annealing on the electrical properties of p++GaP/p-GaAsPN/n+GaP diodes were investigated by using current-voltage (I-V), capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) techniques in the temperature range from 100 K to 440 K. It was observed that rapid thermal annealing treatment improves the electrical characteristics of as-grown structures. The annealed samples showed an ideality factor lower than the as-grown samples for all temperatures. The ideality factor values from I-V characteristics has changed between 6.8 and 1.9 in the temperature range of 110-430 K for as grown diode, and between 6.3 and 1.44 in the temperature range 100-400 K for the annealed diode. On the other hand, the barrier height increases and the ideality factor decreases with increasing temperature for all samples. The barrier height values has changed between 0.29 eV and 0.71 eV in the temperature range of 190-430 K for as grown diode, and between 0.38 eV and 0.77 eV in the temperature range 180-420 K for the annealed diode. High values of barrier heights were observed in the annealed samples due to the barrier height in-homogeneities at the p-i-n junction. The net acceptor concentration was calculated to be 1.18 × 1018 cm-3 and 2.11 × 1018 cm-3 for the as-grown and annealed GaAsPN layers, respectively. The net acceptor concentration increases by and the leakage current of the GaAsPN/GaP p-i-n junction decreases by 1-2 orders after RTA. DLTS and Laplace-DLTS measurements reveal three hole traps, H1an(0.06 eV), H2an(0.065 eV) and H3(0.23 eV) in the annealed samples as compared with two hole traps, H4ag(0.07 eV) and H5(0.25 eV) in the as-grown samples. After rapid thermal annealing an extra shallow trap is created

Investigation of the effect of different thicknesses and thermal annealing on the optical properties of GaAs0.1P0.89N0.01 alloys grown on GaP substrates

This work investigates the effect of the thickness of the epitaxial layer (100 nm and 1 μm) on the optical properties of quaternary GaAs0.1P0.89N0.01 alloys. Furthermore, the effect of rapid thermal annealing (RTA) on their properties has been studied using the Photoluminescence (PL) technique. Increasing the thickness of the epilayer led to an enhancement of the PL intensity as well as the energy bandgap, which was shifted to higher energy (from 1.82 eV in 100 nm to 1.94 eV in 1 μm layer). However, the 1.94 eV bandgap energy is not ideal for solar cells based materials grown on GaP substrates. Post-growth thermal annealing by rapid thermal annealing (RTA) for both samples resulted in an enhancement in the optical properties as observed by a decrease of the Full Width at Half Maximum (FWHM) and an increase of the PL intensity. Therefore, all results obtained in this study indicate that GaAs0.1P0.89N0.01 with 100 nm epilayer thick is better choice to fabricate good efficiency solar cells based materials on GaP substrates as compared to 1 μm sample

Effects of Lidocaine and Articaine on Neuronal Survival and Recovery

The local anesthetics lidocaine and articaine are among the most widely used drugs in the dentist’s arsenal, relieving pain by blocking voltage-dependent Naþ channels and thus preventing transmission of the pain signal. Given reports of infrequent but prolonged paresthesias with 4% articaine, we compared its neurotoxicity and functional impairment by screening cultured neural SH-SY5Y cells with formulations used in patients (2% lidocaine + 1:100,000 epinephrine or 4% articaine + 1:100,000 epinephrine) and with pure formulations of the drugs. Voltage-dependent sodium channels Na(v)1.2 and Na(v)1.7 were expressed in SH-SY5Y cells. To test the effects on viability, cells were exposed to drugs for 5 minutes, and after washing, cells were treated with the ratiometric Live/Dead assay. Articaine had no effect on the survival of SH-SY5Y cells, while lidocaine produced a significant reduction only when used as pure powder. To determine reversibility of blockage, wells were exposed to drugs for 5 minutes and returned for medium for 30 minutes, and the calcium elevation induced by depolarizing cells with a high-potassium solution was measured using the calcium indicator Fura-2. High potassium raised calcium in control SH-SY5Y cells and those treated with articaine, but lidocaine treatment significantly reduced the response. In conclusion, articaine does not damage neural cells more than lidocaine in this in vitro model. While this does not question the safety of lidocaine used clinically, it does suggest that articaine is no more neurotoxic, at least in the in vitro setting. © 2018 by the American Dental Society of Anesthesiology

P2X7 Receptor Primes IL-1β and the NLRP3 Inflammasome in Astrocytes Subjected to Mechanical Strain

Inflammatory responses play a key role in many neural pathologies, with localized signaling from non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. Stimulation of the NLRP3 inflammasome is a two-stage process. The priming stage involves upregulation of the biosynthesis of the structural components while activation results in their assembly into the actual inflammasome complex and subsequent activation. The priming step can be rate limiting and can connect insult to chronic inflammation but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammatory conditions is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure (IOP) increased mRNA for inflammasome components IL-1β, NLRP3, ASC, CASP1 and IL-6 in rat and mouse retinas. The P2X7 receptor was implicated in the in vivo mechanosensitive priming of IL-1β and IL-6 transcription and translation. In vitro experiments with optic nerve head astrocytes demonstrated enhanced expression of the IL-1β and IL-6 genes following stretching or swelling. The increase in IL-1β expression was inhibited by degradation of extracellular ATP with apyrase, blocking pannexin hemichannels with carbenoxolone, probenecid or 10Panx1 peptide, P2X7 receptor antagonists (BBG, A839977 or A740003) as well inhibition of the NFκB transcription factor with Bay 11-7082. The swelling-dependent fall in expression of the NFκB inhibitor IκB-α was reduced by treatment of cells with A839977 and in P2X7 knockout mice. In summary, our data suggest that mechanical trauma to the retina results in priming of the NLRP3 inflammasome components and upregulated IL-6 expression and release. This was dependent upon ATP release through pannexin hemichannels and autostimulation of the P2X7 receptor. Since the P2X7 receptor can also trigger inflammasome activation it appears to have a central role in linking mechanical strain to neuroinflammation

Impact of Knowledge and Attitude on Saudis’ Physical Activity Practice and Inactivity Barriers: A Questionnaire-based Study

BACKGROUND: Community participation in physical activity is considered a major public health preference of WHO. Saudi Arabia in the last decades faced many tremendous economic changes leading to adoption of western dietary habits associated with sedentary lifestyle. AIM: We aimed to study the relationship between both physical activity knowledge and attitude of community to the practice of individuals. METHODS: We used a questionnaire consists of a mixture of closed-ended questions. Participants were recruited through direct meetings in local markets, schools, and workplaces. Seven hundred and sixty six individuals agreed to participate. RESULTS: Overall correct answers to questions about importance of physical activity were 76.58%. The predominance of participants’ attitude was to establish public places for physical activity in each neighborhood (92.1%). Participants acknowledged that they exercise to improve their health (47.5%). Participants mainly perform light exercises (47.2%) on basis of 1–3 times weekly (48.9%). About 90.8% of participants admitted that they like to increase duration of their physical activity. CONCLUSIONS: Overall physical activity practice of participants’ needs encourage overcoming obstacles that prevent individuals from practicing especially lack of time

Synthesis and photophysical properties of new reactive fluorophenanthrenes

A series of six new suitably functionalized fluorophenanthrene derivatives were synthesized through a simple procedure, making use of inexpensive starting materials under mild conditions. The target phenanthrenes were characterized by 1H and 13C NMR and FT-IR spectroscopies. UV–Vis absorption and photoluminescence of these phenanthrenes were evaluated in solutions. A notable behavior and a strong fluorescence in the blue region of the visible spectrum were observed, making them potential candidates for organic light-emitting diode technology or advanced materials. Their electrochemical behavior was also experimentally examined in solution, demonstrating an important charge transfer interaction owing to their ${\pi }$-conjugated electronic system

Synthesis and photophysical properties of new reactive fluorophenanthrenes

A series of six new suitably functionalized fluorophenanthrene derivatives were synthesized through a simple procedure, making use of inexpensive starting materials under mild conditions. The target phenanthrenes were characterized by 1H and 13C NMR and FT-IR spectroscopies. UV–Vis absorption and photoluminescence of these phenanthrenes were evaluated in solutions. A notable behavior and a strong fluorescence in the blue region of the visible spectrum were observed, making them potential candidates for organic light-emitting diode technology or advanced materials. Their electrochemical behavior was also experimentally examined in solution, demonstrating an important charge transfer interaction owing to their ${\pi }$-conjugated electronic system

The relationship between periodontitis and diabetic retinopathy: A cross-sectional longitudinal study

BackgroundPeriodontal disease is regarded as the sixth complication of diabetes mellitus. The association of periodontitis with diabetic retinopathy is controversial.AimsThe study aimed to assess the association of periodontitis with diabetic retinopathy.Methods This is a cross-sectional descriptive study conducted at a diabetes centre in Omdurman, Sudan during the period from July to September 2018. One hundred and fifty-nine patients with type 2 diabetes were interviewed using a structured checklist. The demographic data and diabetes complications including retinopathy were recorded. An experienced dentist assessed the participants for periodontitis. The Statistical Package for Social Sciences (SPSS, version 20, New York) was used for data analysis. A P-value of > 0.05 was considered significant.Results Out of 159 patients with type 2 diabetes mellitus (65.4 per cent females), their age mean±SD was 58.13±9.96, periodontal diseases were found in 22.0 per cent of patients, and retinopathy was present in 34.6 per cent, while the number of lost teeth was 3.86±3.05. Between patients, periodontal disease (+) vs. (-), the incidence rate of the followings did not differ retinopathy, neuropathy, nephropathy, and coronary history. However, those with periodontal disease, compared with those without, had significantly more lost teeth P-value < 0.05.ConclusionThe number of lost teeth was higher among patients with diabetic retinopathy. However, a cause and effect cannot be withdrawn. Further larger multi-centre studies assessing the association of retinopathy with the severity of periodontal disease and controlling for other causes of teeth loss are needed

Stimulation of TLR3 Triggers Release of Lysosomal ATP in Astrocytes and Epithelial cells that Requires TRPML1 Channels

Cross-reactions between innate immunity, lysosomal function, and purinergic pathways may link signaling systems in cellular pathologies. We found activation of toll-like receptor 3 (TLR3) triggers lysosomal ATP release from both astrocytes and retinal pigmented epithelial (RPE) cells. ATP efflux was accompanied by lysosomal acid phosphatase and beta hexosaminidase release. Poly(I:C) alkalinized lysosomes, and lysosomal alkalization with bafilomycin or chloroquine triggered ATP release. Lysosomal rupture with glycyl-L-phenylalanine-2-naphthylamide (GPN) eliminated both ATP and acid phosphatase release. Secretory lysosome marker LAMP3 colocalized with VNUT, while MANT-ATP colocalized with LysoTracker. Unmodified membrane-impermeant 21-nt and “non-targeting” scrambled 21-nt siRNA triggered ATP and acid phosphatase release, while smaller 16-nt RNA was ineffective. Poly(I:C)-dependent ATP release was reduced by TBK-1 block and in TRPML1−/− cells, while TRPML activation with ML-SA1 was sufficient to release both ATP and acid phosphatase. The ability of poly(I:C) to raise cytoplasmic Ca2+ was abolished by removing extracellular ATP with apyrase, suggesting ATP release by poly(I:C) increased cellular signaling. Starvation but not rapamycin prevented lysosomal ATP release. In summary, stimulation of TLR3 triggers lysosomal alkalization and release of lysosomal ATP through activation of TRPML1; this links innate immunity to purinergic signaling via lysosomal physiology, and suggests even scrambled siRNA can influence these pathways