Metal oxide resistive-type nano-scale gas sensors have been investigated for their low cost, high sensitivity, and environmentally friendly fabrication. In these sensors, electrical resistance ...measurements are used to detect the presence of gas. In n-type metal oxides, resistance is increased by coverage of adsorbed oxygen and lowered by removal of adsorbed oxygen through reactions with reducing gasses. The sensitivity and selectivity of these sensors have been improved by incorporation of heterostructures. Heterostructures may improve sensor performance through facilitating catalytic activity, increasing adsorption, and creating a charge carrier depletion layer that produces a larger modulation in resistance. Synergistic effects in these gas sensors describe the improved sensor signal due to these combined effects which act to amplify the reception and transduction of the sensor signal. Receptive mechanisms may be improved by increasing adsorption and reactivity. Transduction mechanisms may be improved by restriction of the major charge conduction channels which helps to maximize resistance modulation. In this review, the synergistic effect achieved by combining these two mechanisms are examined. Fundamental properties of the metal oxide surface are used to provide insight for the large body of experimental evidence available for metal oxide resistive-type gas sensors. This review aims to connect experimental evidence to conceptual mechanistic descriptions by examining adsorption processes, charge transfer, reaction mechanisms, morphology, and ambient gas interactions.
DNA is the main target for UV-B-irradiation-induced skin photodamage and accounts for 90 % of all the non-melanoma skin cancers.
In this study, we explored the mechanistic basis of photoprotective ...effect of Trigonelline, a naturally occurring alkaloid from the Trigonella foenum-graecum, against UV-B-induced oxidative DNA Damage Response using Primary Human Dermal Fibroblasts (HDFs) and BALB/C mice as models of skin photodamage.
Primary HDFs were subjected to UV-B exposure (10 mJ/cm2) with or without TG for 24 h. Effect of UV-B exposure and TG treatment was evaluated by analyzing the cell survival, cellular morphology, oxidative stress & DNA damage response markers by performing biochemical studies, florescent microscopy & protein expression studies. In in-vivo study, TG pre-treated BALB/c mice were -irradiated with 180 mJ/cm2 of UV-B dose thrice a week on alternative days for four months, followed by topical application of different concentrations of TG. The photodamage caused by UV-B exposure and its ameleoriation by topical treatment of TG was studied by physical and morphological appearance and analyzing the oxidative stress & DNA damage response markers from skin.
We found that TG significantly alleviates UV-B–induced cell death effects in HDFs. TG protects HDF cells and BALB/c mice from UV-B-induced DNA damage by regulating the expression profile of key protein markers of DNA damage which include P53, ATM, ATR, ϒH2AX, Chk1 and Chk2. We found that TG offers geno-protection to UV-B–irradiated HDFs by alleviating CPD induction, reducing the number of TUNEL positive cells and by decreasing the expression levels of DNA damage marker protein ϒH2AX in immunocytochemistry. Further, we found that TG prevents the UVB induced oxidative stress by activating the PI3K-AKT-Nrf2 signalling pathway. On employing PI3K inhibitor, LY294002, we found the expression of ϒH2AX and p-P53 is significantly increased compared to UV-B treated only, indicating that TG mediates the geno-protection against UV-B irradiation via PI3K-AKT-Nrf2 signalling pathway.
Current study presents for the first time the photo-protective role of TG against UV-B–induced oxidative DNA damage and provides its mechanistic insights also and provide strong evidence for TG to be carried forward as a potential remedial and cosmeceutical agent against UV-B–induced skin photodamage disorders.
•Trigonelline (TG) is an alkaloid natural skin care molecule.•TG prevents the UV-B -induced DNA damage via activation of PI3K-AKT-Nrf2 Pathway.•TG can be developed as a skin care agent against photodamage.
Defective autophagy has been linked to lipotoxicity in several cellular models. We aimed to investigate autophagy in lipid-stimulated hepatoma (Huh7) cells and tested whether 4-phenyl butyric acid ...(4-PBA), a chemical chaperone, has a beneficial role in hepatic fat accumulation and lipotoxicity. We report that long-term (24 h) exposure of hepatocytes to palmitate block autophagic flux that leads to lipid accumulation and cell death. Western blotting analysis showed increased accumulation of SQSTM1/p62, and decreased expression of Beclin1 and Atg7 in palmitate-treated cells. Autophagy inhibition by 3-methyladenine (3-MA) in palmitate-treated cells neither increased SQSTMI/p62 accumulation nor cell death, thus suggesting complete blockade of autophagy by palmitate. 4-PBA reduced lipid accumulation and cell death that were associated with restoration of autophagy. siRNA-mediated knockdown of Atg7 and presence of autophagy inhibitors, 3-MA and chloroquine, resulted in the decrease in lipid-lowering effect of 4-PBA, suggesting that 4-PBA mediates its lipid-lowering effect via autophagy. Apoptotic parameters, including altered Bcl2:Bax ratio and PARP1 cleavage induced by palmitate, were improved by 4-PBA. Our results indicate that palmitate impairs autophagy and increases lipid accumulation in Huh7 cells, whereas 4-PBA plays a protective role in lipid accumulation and lipotoxicity through activation of autophagy.
Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome. The underlying causes of the disease progression in NAFLD are unclear. Recent evidences suggest ...endoplasmic reticulum stress in the development of lipid droplets (steatosis) and subsequent generation of reactive oxygen species (ROS) in the progression to non-alcoholic steatohepatitis (NASH). The signalling pathway activated by disruption of endoplasmic reticulum (ER) homoeostasis, called as unfolded protein response, is linked with membrane biosynthesis, insulin action, inflammation and apoptosis. ROS are important mediators of inflammation. Protein folding in ER is linked to ROS. Therefore understanding the basic mechanisms that lead to ER stress and ROS in NAFLD have become the topics of immense interest. The present review focuses on the role of ER stress and ROS in the pathogenesis of NAFLD. We also highlight the cross talk between ER stress and oxidative stress which suggest and encourage the development of therapeutics for NAFLD. Further we have reviewed various strategies used for the management of NAFLD/NASH and limitations of such strategies. Our review therefore highlights the need for newer strategies with regards to ER stress and oxidative stress.
Resistive-type semiconducting metal oxide (SMOX) sensors offer exciting possibilities for designing sensing systems that can detect extremely low concentrations of gasses relevant for industrial ...applications, environmental monitoring, and human health and safety. Research on this technology has produced sensors with high response, but the ability to predictively design sensing systems for specific applications requires improvements in selective detection. Gas selectivity is necessary to differentiate between multiple gas species that may be present in a given application. This has prevented wide-spread use of this technology in real-world settings. In this work, studies on gas selectivity in semiconducting metal oxide sensors are reviewed with specific emphasis on heterojunctions and fundamental sensing mechanisms. Concepts relating both to receptive and transduction sensor mechanisms are explained. The effects due to gas surface interactions and electronic equilibration are compared and discussed. Both modeling efforts and experimental literature are presented to explain fundamental mechanisms that control sensor behavior. Sensor selectivity is examined to further both fundamental understanding as well as increase real-world applications of semiconducting metal oxides.
Astonishingly 3D printing has excited the world of aerospace. This paper takes stock of the popular 3D printing processes in aerospace. Reasons for their popularity over the traditional manufacturing ...processes are dwelled upon. Materials developed specially for aerospace applications along with their characteristics are discussed. Ongoing activities related to 3D printing at various companies and organisations around the world are looked into. Project works in the area of extra-terrestrial printing are also highlighted. Even though 3D printing processes are operationally simple, they do have limitations in terms of the type, quality, and quantity of the materials they can handle. This paper underlines these points while discussing drawbacks of the printed components. Challenges associated with 3D printing in microgravity are also touched upon. Finally, a glimpse is taken into the future appearance of aerospace industry with 3D printing.
Summary
Background
Prenatal maternal stress may influence offspring's atopic risk through sustained cortisol secretion resulting from activation of the hypothalamic‐pituitary axis (HPA), leading to ...Th2‐biased cell differentiation in the foetus. We undertook a systematic review and meta‐analysis investigating the relationship between prenatal maternal psychosocial stress and risk of asthma and allergy in the offspring.
Methods
We searched 11 electronic databases from 1960 to 2016, searched the grey literature and contacted experts in the field. Type of stress indicator included mood disorders, anxiety, exposure to violence, bereavement and socio‐economic problems occurring during pregnancy, both objectively and subjectively measured. We included all possible asthma and IgE‐mediated allergy outcomes. We conducted random‐effects meta‐analyses to synthesize the data.
Results
We identified 9779 papers of which 30 studies (enrolling >6 million participants) satisfied inclusion criteria. The quality of 25 studies was moderate, 4 were strong, and one was weak. Maternal exposure to any type of stressors was associated with an increased risk of offspring atopic eczema/dermatitis (OR 1.34, 95% CI 1.22‐1.47), allergic rhinitis (OR 1.30, 95% CI 1.04‐1.62), wheeze (OR 1.34, 95% CI 1.16‐1.54) and asthma (OR 1.15, 95% CI 1.04‐1.27). Exposure to anxiety and depression had strongest effect compared to other stressors. Exposure during the third trimester had the greatest impact compared to first and second trimesters. The increased risk was stronger for early‐onset and persistent than for late‐onset wheeze. Bereavement of a child (HR 1.28, 95% CI 1.10‐1.48) or a spouse (HR 1.40, 95% CI 1.03‐1.90) increased the risk of offspring asthma.
Conclusions
Exposure to prenatal maternal psychosocial stress was associated with increased risk, albeit modestly, of asthma and allergy in the offspring. The pronounced risk during the third trimester may represent cumulative stress exposure throughout pregnancy rather than trimester‐specific effect. Our findings may represent a causal effect or a result of inherent biases in studies, particularly residual confounding.
Advances in healthcare wearable devices Iqbal, Sheikh M. A.; Mahgoub, Imadeldin; Du, E ...
Npj flexible electronics,
04/2021, Letnik:
5, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
Wearable devices have found numerous applications in healthcare ranging from physiological diseases, such as cardiovascular diseases, hypertension and muscle disorders to neurocognitive ...disorders, such as Parkinson’s disease, Alzheimer’s disease and other psychological diseases. Different types of wearables are used for this purpose, for example, skin-based wearables including tattoo-based wearables, textile-based wearables, and biofluidic-based wearables. Recently, wearables have also shown encouraging improvements as a drug delivery system; therefore, enhancing its utility towards personalized healthcare. These wearables contain inherent challenges, which need to be addressed before their commercialization as a fully personalized healthcare system. This paper reviews different types of wearable devices currently being used in the healthcare field. It also highlights their efficacy in monitoring different diseases and applications of healthcare wearable devices (HWDs) for diagnostic and treatment purposes. Additionally, current challenges and limitations of these wearables in the field of healthcare along with their future perspectives are also reviewed.
Allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish constitutes the majority of food allergy reactions, but reliable estimates of their prevalence are lacking. This ...systematic review aimed to provide up‐to‐date estimates of their prevalence in Europe.Studies published in Europe from January 1, 2000, to September 30, 2012, were identified from searches of four electronic databases. Two independent reviewers appraised the studies and extracted the estimates of interest. Data were pooled using random‐effects meta‐analyses. Fifty studies were included in a narrative synthesis and 42 studies in the meta‐analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self‐reported lifetime prevalence of allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0% (95% confidence interval: 5.7–6.4), 2.5% (2.3–2.7), 3.6% (3.0–4.2), 0.4% (0.3–0.6), 1.3% (1.2–1.5), 2.2% (1.8–2.5), and 1.3% (0.9–1.7), respectively. The prevalence of food‐challenge‐defined allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish was 0.6% (0.5–0.8), 0.2% (0.2–0.3), 0.1% (0.01–0.2), 0.3% (0.1–0.4), 0.2% (0.2–0.3), 0.5% (0.08–0.8), 0.1% (0.02–0.2), and 0.1% (0.06–0.3), respectively. Allergy to cow's milk and egg was more common among younger children, while allergy to peanut, tree nuts, fish, and shellfish was more common among the older ones. There were insufficient data to compare the estimates of soy and wheat allergy between the age groups. Allergy to most foods, except soy and peanut, appeared to be more common in Northern Europe. In summary, the lifetime self‐reported prevalence of allergy to common foods in Europe ranged from 0.1 to 6.0%. The heterogeneity between studies was high, and participation rates varied across studies reaching as low as <20% in some studies. Standardizing the methods of assessment of food allergies and initiating strategies to increase participation will advance this evidence base.
Drought stress is one of the most immense and permanent constraints in agriculture, which leads to a massive loss of crop productivity. However, little is known about the mitigation role of ...exogenously applied abscisic acid (ABA) and jasmonic acid (JA) in pearl millet (Pennisetum glaucum L.) under PEG‐induced drought stress. Therefore, the current study investigated the putative role of exogenous ABA and JA in improving drought stress tolerance in pearl millet. Thirteen‐day‐old seedlings were exposed to six different treatments as follow; control (ck), PEG‐600 (20%), JA (100 μM), ABA (100 μM), PEG+JA, and PEG+ABA, and data were collected at 7 and 14 days after treatment (DAT). Results showed that PEG decreased plant growth while the oxidative damage increased due to over production of H2O2 and MDA content as a result of decreased activities of the antioxidative enzymes including APX, CAT, and SOD in the leaves. However, exogenous ABA and JA positively enhanced the growth profile of seedlings by improving chlorophyll and relative water content under PEG treatment. A significant improvement was observed in the plant defense system resulting from increased activities of antioxidative enzymes due to exogenous ABA and JA under PEG. Overall, the performance of JA was found better than ABA under PEG‐induced drought stress, and future investigations are needed to explore the potential effects of these phytohormones on the long‐term crop management and productivity under drought stress.
PDF
