As populations grow, global energy consumption in the next 30 years is predicted to rise by nearly 50%. Nowadays and many years before, the most energy worldwide is provided by fossil fuel which leads to severe pollution and contributes to the greenhouse effect. Hydrogen is the most ideal alternative clean energy, but currently, there is no significant hydrogen production from renewable sources. Hence, there is an urgent need for the development of new photocatalysts which will allow a water splitting for hydrogen production. The photocatalytic water splitting using TiO 2 offers a promising approach for clean, low-cost, and environmentally friendly production of hydrogen as a sustainable fuel. This paper reviews some recently used methods of synthesis such as hydrothermal, rapid breakdown anodization method, impregnation method, and sol-gel synthesis for the preparation of modified TiO 2 materials. These methods of synthesis provide the production of ultra-thin mesoporous TiO 2 nanosheets, nanorods, and nanotubes as well as heterojunction structures. Some investigations show that introduction of Ti 3+ atomic defects is beneficial for the photocatalytic water splitting for hydrogen generation. Some progress has been achieved by heterocoupling the two or more semiconductors. There is experimental evidence that in the presence of alcohol as a sacrificial agent, H 2 production rates decreased from a higher number of hydroxyl groups i.e. in order 3>2>1. The H 2 generation is also larger when TiO 2 is modified with the addition of small quantity of metal nanoparticles such as Pt, Pd, and Ni. One study has shown that the samples sensitised with Pt nanoparticles were superior to Pd and Ni modified TiO 2 , the other has shown that the co-catalyst activity followed the order Pd>Pt≈Au.

The election of Donald Trump to the presidency of the United States missed by a mere few weeks the 120th anniversary of the opening night of Alfred Jarry’s Ubu the King (10 December 1896). Numerous similarities between the 45th US president and the character that inaugu -rated the theatrical avantgarde didn’t go unnoticed. The poet Charles Simic wrote that the “story of his presidency and the cast of characters he has assembled in the White House would easily fit into Jarry’s play without a single word needing to be changed” (Simic 2017). British author Rosanna Hildyard had the same idea when she published her translation and adaptation of Jarry’s play under a tell-all title: Ubu Trump (2017). And early in 2018, Paula Vogel organized a “National UBU ROI Bake-Off” in which she invited playwrights to compose skits featuring key “ingredients” from Jarry’s play. So, on Presidents’ Day (19 February 2018) theatres across the country performed pieces that ranged from a farce about Trump and Anthony Scaramucci, who briefly and scandalously held the position of White House communications director, to a monologue by an actor playing Melania Trump, to Ubu’s funeral. More recently, in late February 2020, an advertisement from Verso Books for Hal Foster’s new book What Comes after Farce? landed in my inbox. The blurb is spot on:

In hematopoietic cell transplants, alloreactive T cells mediate the graft-versus-leukemia (GVL) effect. However, leukemia relapse accounts for nearly half of deaths. Understanding GVL failure requires a system in which GVL-inducing T cells can be tracked. We used such a model wherein GVL is exclusively mediated by T cells that recognize the minor histocompatibility antigen H60. Here we report that GVL fails due to insufficient H60 presentation and T cell exhaustion. Leukemia-derived H60 is inefficiently cross-presented whereas direct T cell recognition of leukemia cells intensifies exhaustion. The anti-H60 response is augmented by H60-vaccination, an agonist αCD40 antibody (FGK45), and leukemia apoptosis. T cell exhaustion is marked by inhibitory molecule upregulation and the development of TOX+ and CD39−TCF-1+ cells. PD-1 blockade diminishes exhaustion and improves GVL, while blockade of Tim-3, TIGIT or LAG3 is ineffective. Of all interventions, FGK45 administration at the time of transplant is the most effective at improving memory and naïve T cell anti-H60 responses and GVL. Our studies define important causes of GVL failure and suggest strategies to overcome them. In hematopoietic stem cell transplants, T cells mediate graft-versus-leukemia (GVL), but GVL can fail leading to leukemia relapse. Here the authors use a mouse model in which T cells target the minor histocompatibility antigen H60 to show how this can occur, characterize the CD8+ T cell response and demonstrate how anti-CD40 antibody therapy improves GVL.

An amendment to this paper has been published and can be accessed via the original article.

This article proposes geometrically-based stochastic channel model with scatterers homogeneously distributed within <inline-formula> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula>-dimensional (<inline-formula> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula>-D) hyperspherical-shaped scattering region for single-bounce propagation scenario, with arbitrary positions of base station (BS) and mobile station (MS). For such defined geometrically-based stochastic channel model, the angular and temporal statistics are determined by introducing the projective approach. Accordingly, azimuthal angle and time of arrival marginal PDFs are derived in closed form, while the elevation angle PDF can be delivered numerically in general, and in closed-form for specific environmental parameters. The fidelity of the analytically obtained results is evaluated by their comparison to the corresponding normalized histograms. Also, it is shown that the proposed <inline-formula> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula>-D model can be used to analyze some of the existing channel models like 2-D uniform disk and 3-D uniform (hemi)sphere models. Additionally, by introducing the mentioned projective approach, it is shown that the angular statistics of the proposed <inline-formula> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula>-D model are the same as the angular statistics of some nonuniform 2-D and 3-D models, which is an important property of the proposed model. Such observation enabled us, for the first time in the literature, to determinate angular statistics for geometrically-based stochastic channel models such as inverted parabolic scattering model, 2-D Gaussian model and 3-D Gaussian hemisphere model, for arbitrary positions of BS and MS. Such angular characteristics of proposed channel model are validated through several empirical datasets.

Dear Editor-in-Chief Marius M. Scarlat, We have read with great attention the article “Medications in COVID-19 patients: summarizing the current literature from an orthopaedic perspective”, written by Shi Heng Sharon Tan and colleagues (Authors) in the forthcoming August issue of International Orthopaedics [1]. We welcome the opportunity to make a short comment as well. This very interesting article evaluates current literature regarding common medications prescribed in orthopaedic surgery and their potential implications in COVID-19 patients. The Authors emphasized that vitamins are commonly prescribed in various orthopaedic conditions. We want to highlight that older people are in increased risk for mortality due to pandemic of COVID-19, but also for different vascular accidents after hip and/or other bone fractures. Also, hyperhomocysteinemia is common in elderly people and often associated increased risk for fractures and cardiovascular diseases, too. Interestingly, values of vitamin B9 (folic acid) and B12 are in negative correlation with levels of homocysteine [2]. Unfortunately, hyperhomocysteinemia appeared to be predictive of all-cause mortality, independent of frailty, an agerelated clinical state characterized by a global impairment of physiological functions and involving multiple organ systems [3]. In one of the very rare studies, high number of pulmonary embolism was noted in COVID-19 pneumonia patients (20.6%), despite the fact that 90% of them were receiving prophylactic antithrombotic treatment due to the current guidelines [4]. Furthermore, according to PubMed survey, there was no reliable data due to concomitance of COVID19, hyperhomocysteinemia and osteoporosis/fractures. So, what to do when we have older COVID-19 patient with high risks for different cardiovascular diseases, including pulmonary thromboembolism, as well as bone fracture? There is an urgent need to different opinions and recommendations, when proper data are absent due to enormous speed of COVID-19 disaster. Clinicians need to adapt to the challenges posed by this crisis and consider ways to continue serving the most vulnerable amongst us, those with chronic disease with their own substantive morbidity and mortality [5]. In light of this, we suggest that level of homocysteine and B9/B12 vitamin should be measured at clinical follow-up in all patients with COVID-19, immediately after hospitalization. If persistent, hyperhomocysteinemic proosteoporotic/ procoagulability state should be promptly decreased in acute phase of COVID-19, on the base of Latin phrase primum non nocere. Our studies from Bosnia and Herzegovina showed that the intake of B9 vitamin, sometimes with B12 vitamin as well, was efficient in creating normalized homocysteine levels in older patients with ischemic stroke and Parkinson’s disease [6, 7]. Fortunately, risk of side effects is minimal if the daily dose of B9 vitamin is 1–5 mg [8]. In addition, B2/B3/B6 vitamins are, as Authors wrote, enhancers of the immune system and might be efficient as soldiers from second echelon in battling with COVID-19. Lastly, we emphasize that further studies will elucidate hidden but also harmful potential of hyperhomocysteinemia on bone fractures/vascular accidents in COVID-19 patients as well as beneficial add-on effects of B9/B12 vitamin on their osteoporotic/vascular complications. * Suljo Kunić suljo.kunic@hotmail.com

AbstractDeveloping beneficial applications for sewage sludge is a key challenge in many countries, given the amount of sludge generated and the disposal or recycling options currently available. Se...

The original published article contained a mistake.

Lipid dyshomeostasis is associated with the most common form of dementia, Alzheimer’s disease (AD). Substantial progress has been made in identifying positron emission tomography (PET) and cerebrospinal fluid (CSF) biomarkers for AD, but they have limited use as front-line, non-invasive diagnostic tools. Small extracellular vesicles (EVs) are released by all cell types and contain an enriched subset of their parental cell molecular composition, including lipids. EVs are released from the brain into the periphery, providing a potential source of tissue and disease specific lipid biomarkers. However, the EV lipidome of the central nervous system (CNS) is currently unknown and the potential of brain-derived EVs (BDEVs) to inform on lipid dyshomeostasis in AD remains unclear. The aim of this study was to reveal the lipid composition of BDEVs in human frontal cortex tissue, and to determine whether BDEVs in AD have altered lipid profiles compared to age-matched neurological controls (NC). Here, using semi-quantitative mass spectrometry, we describe the BDEV lipidome, covering 4 lipid categories, 17 lipid classes and 692 lipid molecules. Frontal cortex-derived BDEVs were enriched in glycerophosphoserine (PS) lipids, a characteristic of small EVs. Here we report that BDEVs are enriched in ether-containing PS lipids. A novel finding that further establishes ether lipids as a feature of EVs. While no significant changes were detected in the frontal cortex in AD, the lipid profile of the BDEVs from this tissue exhibited disease related differences. AD BDEVs had altered glycerophospholipid (GP) and sphingolipid (SP) levels, specifically increased plasmalogen glycerophosphoethanolamine (PE-P) and decreased polyunsaturated fatty acyl containing lipids (PUFAs), and altered amide-linked acyl chain content in sphingomyelin (SM) and ceramide (Cer) lipids relative to vesicles from neurological control subjects. The most prominent alteration being a two-fold decrease in lipid species containing docosahexaenoic acid (DHA). The in-depth lipidome analysis provided in this study highlights the advantage of EVs over more complex tissues for improved detection of dysregulated lipids that may serve as potential biomarkers in the periphery.