Nanotechnology and chiroptical spectroscopy to characterise optically active chiral metamaterials

Work in this thesis involves manipulating the interaction between light and matter in order to retrieve important information from adsorbed molecules, such as their structure and/or function, and henceforth, to gain insight into highly sensitive detection capabilities for biosensor applications. Such manipulation might be achieved via rationalising the surfaces of optically active metamaterials by taking full advantage of the recent growth in a variety of nanotechnology disciplines. As such, the possibility of characterising biomolecules adsorbed on the surface of chiral and achiral plasmonic metamaterials, referred to as chiral and achiral plasmonic nanostructures, have been investigated. Also, illustration and applications for the so called `Superchiral Field`, which has been generated via circular polarised light (CPL), are presented. Microscopic origin of the chiroptical second harmonic generation (SHG) signal that originates from the surface of the chiral nanostructures has been investigated. Practical visualisation via femtosecond laser beam of regions of intense plasmonic activity, i.e., hot-spot mapping, has been performed. In general, the work described in this thesis involved the use of several linear and non-linear chiroptical techniques namely as extinction (absorption and scattering), CD, ORD and SHG spectroscopy, in addition to scanning imaging namely SEM and AFM microscopy. Given that most biomolecules contain either chiral molecules or adopt chiral structures, the plasmonic nanostructures presented in this work could be used to study a wide range of biological problems, from the structure of biomolecules associated with neurodegenerative illnesses such as Alzheimer’s disease and Parkinson’s disease, to DNA and viruses. As a regard, general classifications for aspects of chirality are presented in order to emphasise the association of the samples used in this chapter with some of these aspects. All samples are fabricated via Electron Beam Lithography (EBL) in JWNC cleanroom/UK; the associated fabrication techniques, the instruments and the experimental methods are described

Nanotechnology and chiroptical spectroscopy to characterise optically active chiral metamaterials

Work in this thesis involves manipulating the interaction between light and matter in order to retrieve important information from adsorbed molecules, such as their structure and/or function, and henceforth, to gain insight into highly sensitive detection capabilities for biosensor applications. Such manipulation might be achieved via rationalising the surfaces of optically active metamaterials by taking full advantage of the recent growth in a variety of nanotechnology disciplines. As such, the possibility of characterising biomolecules adsorbed on the surface of chiral and achiral plasmonic metamaterials, referred to as chiral and achiral plasmonic nanostructures, have been investigated. Also, illustration and applications for the so called `Superchiral Field`, which has been generated via circular polarised light (CPL), are presented. Microscopic origin of the chiroptical second harmonic generation (SHG) signal that originates from the surface of the chiral nanostructures has been investigated. Practical visualisation via femtosecond laser beam of regions of intense plasmonic activity, i.e., hot-spot mapping, has been performed. In general, the work described in this thesis involved the use of several linear and non-linear chiroptical techniques namely as extinction (absorption and scattering), CD, ORD and SHG spectroscopy, in addition to scanning imaging namely SEM and AFM microscopy. Given that most biomolecules contain either chiral molecules or adopt chiral structures, the plasmonic nanostructures presented in this work could be used to study a wide range of biological problems, from the structure of biomolecules associated with neurodegenerative illnesses such as Alzheimer’s disease and Parkinson’s disease, to DNA and viruses. As a regard, general classifications for aspects of chirality are presented in order to emphasise the association of the samples used in this chapter with some of these aspects. All samples are fabricated via Electron Beam Lithography (EBL) in JWNC cleanroom/UK; the associated fabrication techniques, the instruments and the experimental methods are described

A High-Energy-Density Magnesium-Air Battery with Nanostructured Polymeric Electrodes

The greenhouse emissions are biggest challenge of the present era. The renewable power sources are required to have characteristics of good charge capacity, energy density with proven charging discharging cycles for energy storage and applications. Mg-air batteries (MABs) are an alternative renewable power source due to their inexpensive cost. In particular, the previous reports presented the metal-air battery structure, with a specific energy overall output of 765 W h kg(−1). This paper is focused mainly on the MAB, which employed nanocomposite polymeric electrodes with a proven energy density of 545 W h kg(−1) and a charge capacity of 817 mA h g(−1) when electrolyzed at a cycling current density of 7 mA cm(−2)

Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Comparative study of efficacy of prepartum injection of multivitamins and selenium- vitamin E (ά-tocopherol)-combination on post-partum clinical findings, serum steroids, calf and placental weights, and milk antioxidant biomarkers changes in female dromed

Background: All concentrates given to camels were enriched in selenium (Se) in selenite form. The impacts of Se supplementation on lactating female health, milk, and Se/antioxidant statuses received no research interest. Aim: The current study aimed to compare the efficacy of long-term prepartum injection of Se-vitamin E combination and multivitamins on maternal post-calving clinical findings, serum steroid hormones, milk antioxidants, milk somatic cell count (SCC) status, calf body weight, placental weight (PW), and vaginal wash isolates. Methods: From three equal groups of postpartum she-camels (n = 45), one group received no treatment and served as control group (Cont.; n = 15). For 3 months prepartum, one group had received a combination of vitamin E (ά-tocopherol) and Se (VitE-Se-; n = 15), and the third one received multivitamins (Multi-; n = 15). All dams were subjected to clinical and laboratory assays including milk total antioxidant capacity (TAC), Se, vitamin E, and milk SCC on Days 14, 21, and 28 post-calving. Steroid hormones and calf and PW were estimated at birth (Day 0). Results: The study reported higher efficacy of Se-vitamin E combination comparing with that of multivitamins as a long-term prepartum injection in recently calved she-camels that was reflected through significant changes in steroids hormones (Drop), i.e., progesterone (P4) and estradiol (E2), the milk antioxidant biomarkers (Elevation), i.e., TAC, Se, vitamin E, and milk SCCs (Reduction). Both two therapeutic regimens had a more powerful effect that the control one. Conclusion: The applied therapeutic supplements had no significant effect on clinical and hematological changes as well as calves’ body weights and PWs. Body weights were significantly higher in male camel calves than those of female calves either in Cont., VitE-Se-, or Multi-

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA): past, present, and future implications

Adjuvants such as aluminum, mineral oils, and silicone are added to vaccines in order to trigger a stronger immune response. Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) was introduced in 2011 to address nonspecific symptoms and disorders appearing following vaccinations, which in fact were reported by many papers before the introduction of the syndrome. During the pandemic of COVID-19, a correlation between ASIA, COVID-19, and COVID-19 vaccines has been reported. Adjuvants, as the name indicates, are adjoined material aimed to assist in functioning as when added to vaccines they are meant to boost the effect and strongly stimulate the immune system. The response of the immune system can be unpredictable, and the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) was developed to address possible adverse reactions of an autoimmune and inflammatory type that may be caused by adjuvants. While ASIA, as a syndrome, was coined and defined in 2011; reports describing patients with vague and nonspecific clinical symptoms following vaccinations appeared much earlier. In other words, ASIA came to define, arrange, and unite the variety of symptoms, related to autoimmunity, caused not by the vaccine itself, rather by the adjuvant part of the vaccine such as aluminum, among others. Accordingly, the introduction of ASIA enabled better understanding, proper diagnosis, and early treatment of the disorder. Furthermore, ASIA was shown to be associated with almost all body systems and various rheumatic and autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome, and systemic sclerosis. In addition, the correlation between COVID-19 and ASIA was noticed during the pandemic. In this review, we summarized the reported effects of adjuvants and medical literature before and after ASIA was defined, the several ways ASIA can manifest and impact different systems of the body, and the incidences of ASIA during the COVID-19 pandemic. It is important to clarify, that vaccines are among, if not the, most effective means of fighting infectious diseases however, we believe that vaccines manufacturing is not above criticism, particularly when it comes to added substances possessing a risk of side effects

The mosaic of autoimmunity – Finally discussing in person. The 13th international congress on autoimmunity 2022 (AUTO13) Athens

While autoimmunity is a branch of medicine linked to every single organ system via direct and indirect pathways, meeting in person to discuss autoimmunity during the 13th international congress on autoimmunity (AUTO13) with participants from all over the world had a very good reason. The mechanisms involved in autoimmune diseases are of extreme importance and in fact critical in understanding the course of diseases as well as selecting proper therapies. COVID-19 has served as a great example of how autoimmunity is deeply involved in the disease and directly correlated to severity, morbidity, and mortality. For instance, initially the term cytokine storm dominated, then COVID-19 was addressed as the new member of the hyperferritinemic syndrome, and also the use of immunosuppressants in patients with COVID-19 throughout the pandemic, all shed light on the fundamental role of autoimmunity. Unsurprisingly, SARS-CoV-2 was called the “autoimmune virus” during AUTO13. Subsequently, the correlation between autoimmunity and COVID-19 vaccines and post-COVID, all were discussed from different autoimmune aspects during the congress. In addition, updates on the mechanisms of diseases, autoantibodies, novel diagnostics and therapies in regard to autoimmune diseases such as antiphospholipid syndrome, systemic lupus erythematosus, systemic sclerosis and others, were discussed in dedicated sessions. Due to the magnificence of the topics discussed, we aimed to bring in our article hereby, the pearls of AUTO13 in terms of updates, new aspects of autoimmunity, and interesting findings. While more than 500 abstract were presented, concluding all the topics was not in reach, hence major findings were summarized

Quarantining arriving travelers in the era of COVID-19: balancing the risk and benefits a learning experience from Bahrain

The quarantine period imposed to travelers in many countries due to COVID19 is a major obstacle for any traveler. Lifting the quarantine period could lead to significant improvement in people’s quality of life and any country’s economy. Bahrain have used two quarantine models from arriving passengers. We report data about the incidence of COVID19 on arriving passengers at Bahrain International airport. Infection rates were reported on arrival, during quarantine and after leaving quarantine. Results showed that travelers had low incidence of COVID19 on arriving and during the quarantine period, while becoming at higher risk after leaving quarantine. We concluded that quarantine requirement maybe lifted for arriving travelers. Testing upon arrival with implementation of the public health preventative measures can minimize the risk of transmission

Left Main Coronary Artery Revascularization in Patients with Impaired Renal Function: Percutaneous Coronary Intervention versus Coronary Artery Bypass Grafting

Introduction: The evidence about the optimal revascularization strategy in patients with left main coronary artery (LMCA) disease and impaired renal function is limited. Thus, we aimed to compare the outcomes of LMCA disease revascularization (percutaneous coronary intervention [PCI] vs. coronary artery bypass grafting [CABG]) in patients with and without impaired renal function. Methods: This retrospective cohort study included 2,138 patients recruited from 14 centers between 2015 and 2,019. We compared patients with impaired renal function who had PCI (n= 316) to those who had CABG (n = 121) and compared patients with normal renal function who had PCI (n = 906) to those who had CABG (n = 795). The study outcomes were in-hospital and follow-up major adverse cardiovascular and cerebrovascular events (MACCE). Results: Multivariable logistic regression analysis showed that the risk of in-hospital MACCE was significantly higher in CABG compared to PCI in patients with impaired renal function (odds ratio [OR]: 8.13 [95% CI: 4.19–15.76], p < 0.001) and normal renal function (OR: 2.59 [95% CI: 1.79–3.73]; p < 0.001). There were no differences in follow-up MACCE between CABG and PCI in patients with impaired renal function (HR: 1.14 [95% CI: 0.71–1.81], p = 0.585) and normal renal function (HR: 1.12 [0.90–1.39], p = 0.312). Conclusions: PCI could have an advantage over CABG in revascularization of LMCA disease in patients with impaired renal function regarding in-hospital MACCE. The follow-up MACCE was comparable between PCI and CABG in patients with impaired and normal renal function

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care