Recognition of peptidoglycan and b-lactam antibiotics by the extracellular domain of the Ser/Thr protein kinase StkP from Streptococcus pneumoniae

The eukaryotic-type serine/threonine kinase StkP from Streptococcus pneumoniae is an important signal-transduction element that regulates the expression of numerous pneumococcal genes. We have expressed the extracellular C-terminal domain of StkP kinase (C-StkP), elaborated a three-dimensional structural model and performed a spectroscopical characterization of its structure and stability. Biophysical experiments show that C-StkP binds to synthetic samples of the cell wall peptidoglycan (PGN) and to β-lactam antibiotics, which mimic the terminal portions of the PGN stem peptide. This is the first experimental report on the recognition of a minimal PGN unit by a PASTA-containing kinase, suggesting that non-crosslinked PGN may act as a signal for StkP function and pointing to this protein as an interesting target for β-lactam antibiotics

Smarter greener cities through a social-ecological-technological systems approach

Publisher Copyright: © 2022Smart city development is expanding rapidly globally and is often argued to improve urban sustainability. However, these smart developments are often technology-centred approaches that can miss critical interactions between social and ecological components of urban systems, limiting their real impact. We draw on the social-ecological-technological systems (SETS) literature and framing to expand and improve the impact of smart city agendas. A more holistic systems framing can ensure that ‘smart’ solutions better address sustainability broadly and extend to issues of equity, power, agency, nature-based solutions and ecological resilience. In this context, smart city infrastructure plays an important role in enabling new ways of measuring, experiencing and engaging with local and temporal dynamics of urban systems. We provide a series of examples of subsystems interactions, or ‘couplings’, to illustrate how a SETS approach can expand and enhance smart city infrastructure and development to meet normative societal goals.Peer reviewe

Entanglement of single-photons and chiral phonons in atomically thin WSe2_2

Quantum entanglement is a fundamental phenomenon which, on the one hand, reveals deep connections between quantum mechanics, gravity and the space-time; on the other hand, has practical applications as a key resource in quantum information processing. While it is routinely achieved in photon-atom ensembles, entanglement involving the solid-state or macroscopic objects remains challenging albeit promising for both fundamental physics and technological applications. Here, we report entanglement between collective, chiral vibrations in two-dimensional (2D) WSe$_2$ host --- chiral phonons (CPs) --- and single-photons emitted from quantum dots (QDs) present in it. CPs which carry angular momentum were recently observed in WSe$_2$ and are a distinguishing feature of the underlying honeycomb lattice. The entanglement results from a "which-way" scattering process, involving an optical excitation in a QD and doubly-degenerate CPs, which takes place via two indistinguishable paths. Our unveiling of entanglement involving a macroscopic, collective excitation together with strong interaction between CPs and QDs in 2D materials opens up ways for phonon-driven entanglement of QDs and engineering chiral or non-reciprocal interactions at the single-photon level

A eukaryotic-type signalling system of Pseudomonas aeruginosa contributes to oxidative stress resistance, intracellular survival and virulence

<p>Abstract</p> <p>Background</p> <p>The genome of <it>Pseudomonas aeruginosa </it>contains at least three genes encoding eukaryotic-type Ser/Thr protein kinases, one of which, <it>ppkA</it>, has been implicated in <it>P. aeruginosa </it>virulence. Together with the adjacent <it>pppA </it>phosphatase gene, they belong to the type VI secretion system (H1-T6SS) locus, which is important for bacterial pathogenesis. To determine the biological function of this protein pair, we prepared a <it>pppA-ppkA </it>double mutant and characterised its phenotype and transcriptomic profiles.</p> <p>Results</p> <p>Phenotypic studies revealed that the mutant grew slower than the wild-type strain in minimal media and exhibited reduced secretion of pyoverdine. In addition, the mutant had altered sensitivity to oxidative and hyperosmotic stress conditions. Consequently, mutant cells had an impaired ability to survive in murine macrophages and an attenuated virulence in the plant model of infection. Whole-genome transcriptome analysis revealed that <it>pppA-ppkA </it>deletion affects the expression of oxidative stress-responsive genes, stationary phase σ-factor RpoS-regulated genes, and quorum-sensing regulons. The transcriptome of the <it>pppA-ppkA </it>mutant was also analysed under conditions of oxidative stress and showed an impaired response to the stress, manifested by a weaker induction of stress adaptation genes as well as the genes of the SOS regulon. In addition, expression of either RpoS-regulated genes or quorum-sensing-dependent genes was also affected. Complementation analysis confirmed that the transcription levels of the differentially expressed genes were specifically restored when the <it>pppA </it>and <it>ppkA </it>genes were expressed ectopically.</p> <p>Conclusions</p> <p>Our results suggest that in addition to its crucial role in controlling the activity of <it>P. aeruginosa </it>H1-T6SS at the post-translational level, the PppA-PpkA pair also affects the transcription of stress-responsive genes. Based on these data, it is likely that the reduced virulence of the mutant strain results from an impaired ability to survive in the host due to the limited response to stress conditions.</p

The additional value of patient-reported health status in predicting 1-year mortality after invasive coronary procedures: A report from the Euro Heart Survey on Coronary Revascularisation

Objective: Self-perceived health status may be helpful in identifying patients at high risk for adverse outcomes. The Euro Heart Survey on Coronary Revascularization (EHS-CR) provided an opportunity to explore whether impaired health status was a predictor of 1-year mortality in patients with coronary artery disease (CAD) undergoing angiographic procedures. Methods: Data from the EHS-CR that included 5619 patients from 31 member countries of the European Society of Cardiology were used. Inclusion criteria for the current study were completion of a self-report measure of health status, the EuroQol Questionnaire (EQ-5D) at discharge and information on 1-year follow-up, resulting in a study population of 3786 patients. Results: The 1-year mortality was 3.2% (n = 120). Survivors reported fewer problems on the five dimensions of the EQ-5D as compared with non-survivors. A broad range of potential confounders were adjusted for, which reached a p<0.10 in the unadjusted analyses. In the adjusted analyses, problems with self-care (OR 3.45; 95% CI 2.14 to 5.59) and a low rating (≤ 60) on health status (OR 2.41; 95% CI 1.47 to 3.94) were the most powerful independent predictors of mortality, among the 22 clinical variables included in the analysis. Furthermore, patients who reported no problems on all five dimensions had significantly lower 1-year mortality rates (OR 0.47; 95% CI 0.28 to 0.81). Conclusions: This analysis shows that impaired health status is associated with a 2-3-fold increased risk of all-cause mortality in patients with CAD, independent of other conventional risk factors. These results highlight the importance of including patients' subjective experience of their own health status in the evaluation strategy to optimise risk stratification and management in clinical practice

Clinical Outcomes With a Repositionable Self-Expanding Transcatheter Aortic Valve Prosthesis: The International FORWARD Study

Background Clinical outcomes in large patient populations from real-world clinical practice with a next-generation self-expanding transcatheter aortic valve are lacking. Objectives This study sought to document the clinical and device performance outcomes of transcatheter aortic valve replacement (TAVR) with a next-generation, self-expanding transcatheter heart valve (THV) system in patients with severe symptomatic aortic stenosis (AS) in routine clinical practice. Methods The FORWARD (CoreValve Evolut R FORWARD) study is a prospective, single-arm, multinational, multicenter, observational study. An independent clinical events committee adjudicated safety endpoints based on Valve Academic Research Consortium-2 definitions. An independent echocardiographic core laboratory evaluated all echocardiograms. From January 2016 to December 2016, TAVR with the next-generation self-expanding THV was attempted in 1,038 patients with symptomatic, severe AS at 53 centers on 4 continents. Results Mean age was 81.8 ± 6.2 years, 64.9% were women, the mean Society of Thoracic Surgeons Predicted Risk of Mortality was 5.5 ± 4.5%, and 33.9% of patients were deemed frail. The repositioning feature of the THV was applied in 25.8% of patients. A single valve was implanted in the proper anatomic location in 98.9% of patients. The mean aortic valve gradient was 8.5 ± 5.6 mm Hg, and moderate or severe aortic regurgitation was 1.9% at discharge. All-cause mortality was 1.9%, and disabling stroke occurred in 1.8% at 30 days. The expected-to-observed early surgical mortality ratio was 0.35. A pacemaker was implanted in 17.5% of patients. Conclusions TAVR using the next-generation THV is clinically safe and effective for treating older patients with severe AS at increased operative risk. (CoreValve Evolut R FORWARD Study [FORWARD]; NCT02592369

Numerical simulation of ventilation in blind headings

Przedmiotem rozważań są problemy i możliwości związane z numerycznym modelowaniem przepływów w wyrobiskach ślepych. Uwaga skoncentrowana jest na prognozowaniu wielkości wentylacyjnych w komorach o parametrach charakterystycznych dla systemu eksploatacji stosowanego w kopalniach LGOM. Omówiono podstawy matematycznego modelowania przepływów turbulentnych. Rozwiązywany układ złożony jest z 3D równań ciągłości, Reynoldsa, turbulentnego transportu składnika chemicznego oraz równań modelu k-epsylon (kinetycznej energii turbulencji i szybkości dysypacji tej energii). Przy dyskretyzacji równań stosowano metodę objętości kontrolnej oraz technikę UPWIND. W opracowanych kodach numerycznych wykorzystano schemat hybrydowy. Nieliniowe układy równań dyskretnych rozwiązywano, stosując procedurę SIMPLER. Przedstawiono wyniki obliczeń 3D pola prędkości i koncentracji gazów w komorach. Badano możliwość skutecznego eliminowania zagrożeń gazowych pochodzących od maszyn wyposażonych w silniki spalinowe i będących wynikiem robót strzałowych. Zamieszczono wyniki symulacji numerycznej ustalonego pola prędkości oraz czasoprzestrzennego pola stężeń gazów szkodliwych przy skupionych i rozłożonych źródłach gazów. Spostrzeżenia wynikające z wariantowych obliczeń umożliwiają określenie warunków, przy których komory mogą być skutecznie przewietrzane wentylatorami wolno-strumieniowymi. Dokładność odwzorowania numerycznego oceniano, porównując wyniki obliczeń z pomiarami. Uznano, że wygenerowany na drodze numerycznej obraz pola prędkości i pola stężeń domieszek gazowych odzwierciedla pola rzeczywiste z wystarczającą dla praktycznych celów dokładnością.The study explores the potential of numerical modelling of airflow in blind headings. The main focus is forecasting the ventilation parameters in headings and galleries characteristic of copper mines belonging to the LGOM Corporation. The fundamentals of mathematical modelling of turbulent flows are provided. The model makes use of 3D continuity and Rynolds equations, the equation of turbulent transport of chemical components and the equations of the k-epsylon model (kinetic energy of turbulence, the rate of kinetic energy dissipation). The discretisation procedure involved the control volume method and the technique UPWIND. The developed numerical codes employ the hybrid schemes and power-law techniques. Nonlinear systems of discrete equations were solved with the use of SIMPLER procedures. 3D velocity fields and gas concentrations calculated for galleries are provided. The chief objective is to eliminate the hazardous conditions caused by the presence of gas pollutants emitted by diesel-powered engines in machines and produced in the course of blasting operations. The results of numerical solutions of steady-state velocity field and the time-space field of concentration of gaseous pollutant emitted by lumped or distributed gas sources are presented. The accuracy of numerical representation is evaluated by comparing the prognosticated values with measurements. The obtained physical fields by way of numerical procedures portray the real fields sufficiently well for practical purposes

Sedimentation of barium sulphate in settler as a method of limitation of solid residues in Jankowice outflow pipe-line

Zjawisko wytrącania się w rurociągach kolektora "Olza" osadów stałych siarczanu baru stanowi poważne zagrożenie dla ich stanu technicznego. Wprowadzanie odpowiednich metod ograniczenia ilości tych osadów pozwala rozwiązać ten problem. Należy pamiętać jednak, że nie każda metoda neutralizacji znajdzie swoje zastosowanie w wybranych kopalniach. Z punktu widzenia kopalni Jankowice najskuteczniejsza wydaje się być metoda sedymentacji osadów w zbiornikach przykopalnianych. Poznanie mechanizmu przebiegu sedymentacji, przy pomocy metody symulacji numerycznej, pozwoliło w przybliżony sposób określić jego efektywność. Jej wartość przy średnicy cząstek 7ź10-6 m wynosi 99%. Problemem jest jednak fakt, niema możności dokładnego określenia średnicy cząsteczek siarczanu baru. Przebieg procesu sedymentacji w osadniku ściśle zależy od jego geometrii i rozmieszczenia otworów wlotowych i wylotowych, a to ma wpływ na czas przebywania cząstek w osadniku. W przypadku osadnika kopalni Jankowice pomiary stężeń jonów baru i siarczanowych na wlocie i wylocie potwierdziły, że proces sedymentacji przebiega praktycznie ze 100% efektywnością. Połączenie chemicznej analizy procesu sedymentacji z analizą jego przebiegu metodą symulacji numerycznej, a także systematyczną kontrolą stężeń jonów na wlocie i wylocie z osadnika stwarza możliwości zastosowania tej metody w innych kopalniach, jak również wykorzystania jej przy projektowaniu nowych zbiorników, tak aby zapewnić najlepsze parametry procesu.The article treats about the process of barium sulphate deposits flow through the Jankowice's settling tank. "Jankowice" coal mine transports its mine waters through the "Olza" retaining-dose system. The waters' chemical character strongly depends on the hydrological lay of land of the south-western part of Upper Silesia. The different chemical character of transported waters is a main reason for precipitation of solid sediments in the interceptor-sewer's pipe-lines. This leads to their overgrowingwith sediment, increasing of water pumping energy and, in the end, necessity of overhaul repairs. Therefore, it is very important to get to know the chemical character of mine waters through the years. Authors described changes of the barium and sulphates ions' concentrations in the water transported to the river from "Jankowice" and "Chwalowice" coal mines in the period of VI 2003-V 2006. From 1993 "Jankowice" mine, through the medium of one big settling tank, drains off its waters with increased concentration of barium ions, and also waters of increased concentration of sulphate ions coming from "Chwalowice" coal mine. The process of precipitation of barium sulphate is almost immediate and it is a source of huge technical problems for the interceptor sewer. It is also very important to analyze the process of chemical sedimentation of barium sulphate by usage of chemical equations. This allows to estimate the amount of sulphates ions needed to precipitate barium ions. Due to the strong contaminations of "Jankowice" and "Chwalowice" waters special water cleansing methods were introduced. They were focused on removing barium and suphate ions and most of them were highly effective. Unfortunately the amount of sulphates ions used in certain methods was insufficientto remove whole barium ions. Therefore, there was another method used. The process of precipitation of barium sulphate is being proceed at the source, that is in the settling tank. In order to prevent penetrating the remaining barium sulphate into the pipe-lines it is necessary to get to know the process of its sedimentation and its efficiency. Numerical simulation of the solid particles flow (barium sulphate) proceeded in this article throughout Fluent 6.1, is the way of describing the sedimentation process. Usage of the two-phase model flow throughout the calculations of the velocity field and trajectory of barium sulphate particles, allows to pinpoint the sedimentation efficiency and the particles' descending time (timeof particles being in the settler). The calculated sedimentation efficiency for the particles of 7ź10-6 m diameter for the "Jankwice" settler was 99%, which means that the whole barium ions were precipitated. Unfortunately difficulties with clear specification of the barium sulphate particles' diameter reflect on the appraisingtheir free descending velocity and in the end on the sedimentation efficiency. Thesedimentation efficiency and descending time depend also on the settler geometry, inlet and outlet placing (water inflow and outflow), and flowing watervolume flux. Thus, the same sedimentation process proceeded in geometrically different settler would give different sedimentation efficiency. Numerical calculations of the different mass flux suspension flow through the settlers of different geometry allow to demonstrate the process of sedimentation. This knowledge might be useful during the settlers' modernization. Not only does it concern the optimization of the settlers' shape and arranging inlet and exit cavities but also designing new objects

Airflow patterns inside a short blind heading

Rozważa się proces przewietrzania krótkiego wyrobiska ślepego realizowany wyłącznie pod wpływem działania wentylatorów głównych. Analizowano obrazy pól prędkości w komorze przy różnych prędkościach przepływu w opływowym prądzie powietrza wynoszących od 0,65 m/s do 2,1 m/s. Obliczenia 3D pól prędkości wykonano przy użyciu metod CFD. Testowano dwa modele turbulencji: standardowy k- i RNG k- oraz dwa sposoby opisu warunków brzegowych: przy pomocy funkcji ściany oraz stosując dwuwarstwowy model warstwy przyściennej. Wyniki obliczeń numerycznych porównywano z pomiarami.Ventilation of short blind heading caused by through road air velocity is considered. A series of numerical tests was performed to determine the effect of different through air velocities on airflow patterns. The velocities ranged between 0,65 m/s and 2,1 m/s. 3D velocity fields was calculated using a finite-volume CFD computer code FLUENT 6.1. Two turbulence models (standard k- and RNG k-) as well as two near-wall models (wall function and enhanced wall treating) were tested. Numerical results were compared with experimental data