Preparation and characterization of spray-dried submicron particles for pharmaceutical application

The versatile use of submicron-sized particles (0.1–1?μm) requires new manufacturing methods. One possibility for the preparation of submicron-sized particles is spray drying. However, the generation of small droplets at a high production rate and the precipitation of submicron particles are quite challenging. In order to produce a sufficient amount of fine and uniform droplets, a two-fluid nozzle with internal mixing was combined with a cyclone droplet separator. The precipitation of particles was realized with an electrostatic precipitator. Considering the difficulty of electrostatic precipitation concerning explosion risks and to make it capable using organic solvents, the spray dryer was integrated in a pressure resistant vessel. Based on previous experiments, the now presented design is compact and the electrostatic precipitator is shortened. In addition, enhanced drying conditions ensured a controlled and reproducible preparation of submicron-sized particles. Thus, high separation efficiencies were shown. Spray-drying experiments were conducted with the model substance mannitol. With the cyclone droplet separator, a fine and uniform spray with a droplet size smaller 2?μm was produced. This robust atomizing technique is capable for high concentrations. For a 10?wt% mannitol solution, particles in the submicron range d_50,3?=?0.7?μm were produced.     

Synthesis and characterisation of silver nanoparticles using leaf extract of Artemisia afra and their in vitro antimicrobial and antioxidant activities

In this study, the conversion of silver ions into ∼30.74 nm sized silver nanoparticles (AgNPs) was achieved in 30 min at a reaction temperature of 80–90°C in aqueous leaf extract of Artemisia afra. The synthesised AgNPs showed surface plasmon resonance in the range of 423–438 nm. Spherical and face‐centred cubic nanoparticles were confirmed by transmission electron microscope (TEM) and X‐ray diffraction (XRD) analysis, respectively. Fourier transform infra‐red (FTIR) results indicated that the obtained nanoparticles were stabilised and capped through the carbonyl and carboxylate ion groups possibly from flavonoids, terpenoids, phenolics and esters content of the extracts. In addition, the AgNPs were assessed for their biological potentials against some microbes and, also, their free radical scavenging ability was established. The AgNPs exhibited interesting antimicrobial and antioxidant properties better than the aqueous extract of A. afra. Inspec keywords: silver, transmission electron microscopy, ultraviolet spectra, visible spectra, surface plasmon resonance, antibacterial activity, X‐ray diffraction, microorganisms, nanoparticles, nanofabrication, Fourier transform infrared spectraOther keywords: silver nanoparticles, reaction temperature, surface plasmon resonance, face‐centred cubic nanoparticles, antioxidant properties, silver ion conversion, aqueous leaf extract, carboxylate ion group, antimicrobial properties, Artemisia afra, spherical nanoparticles, TEM, XRD, FTIR spectra, Ag, temperature 80 degC to 90 degC, time 30.0 min, free radical scavenging, esters, phenolics, terpenoids, flavonoids, carbonyl ion group     

Distributed construction of low-interference spanners

We propose a new low-interference topology for wireless ad hoc networks modeled by Quasi Unit Disk Graphs. Our topology combines two existing structures, the relaxed Greedy structure developed by Damian, Pandit and Pemmaraju, and the low-interference structure developed by Burkhart, von Rickenbach, Wattenhofer and Zollinger. Our main contribution is showing that, when applied on a QUDG G = (V, E), this new structure inherits most properties of the two underlying structures: (i) it is a t(1 + ε) spanner of G, for any t > 1 and ε > 0, (ii) it has optimal interference among all t-spanners for G, (iii) it has O(1) maximum degree, (iv) its total weight is within a factor of O(log Δ) of the weight of a minimum spanning tree for V, where Δ is the aspect ratio of G, and (v) it can be implemented efficiently in O(log Δ + log^* n) rounds of communication. This work was supported by NSF grant CCF-0728909. A preliminary version of this paper, titled “Distributed construction of bounded-degree low-interference spanners of low weight”, appeared in MobiHoc’08.     

Altered Elemental Distribution in Male Rat Brain Tissue as a Predictor of Glioblastoma Multiforme Growth—Studies Using SR-XRF Microscopy

Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used. However, to assess the efficacy and safety of the therapy basing on these models, a deep knowledge of the pathological changes associated with tumor development in the animal brain is necessary. Therefore, as part of our study, the synchrotron radiation-based X-ray fluorescence microscopy was applied for multi-elemental micro-imaging of the rat brain in which glioblastoma develops. Elemental changes occurring in animals after the implantation of two human glioma cell lines as well as the cells taken directly from a patient suffering from GBM were compared. Both the extent and intensity of elemental changes strongly correlated with the regions of glioma growth. The obtained results showed that the observation of elemental anomalies accompanying tumor development within an animal’s brain might facilitate our understanding of the pathogenesis and progress of GBM and also determine potential biomarkers of its extension. The tumors appearing in a rat’s brain were characterized by an increased accumulation of Fe and Se, whilst the tissue directly surrounding the tumor presented a higher accumulation of Cu. Furthermore, the results of the study allow us to consider Se as a potential elemental marker of GBM progression.     

Air-Liquid-Interface Differentiated Human Nose Epithelium: A Robust Primary Tissue Culture Model of SARS-CoV-2 Infection

The global urgency to uncover medical countermeasures to combat the COVID-19 pandemic caused by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has revealed an unmet need for robust tissue culture models that faithfully recapitulate key features of human tissues and disease. Infection of the nose is considered the dominant initial site for SARS-CoV-2 infection and models that replicate this entry portal offer the greatest potential for examining and demonstrating the effectiveness of countermeasures designed to prevent or manage this highly communicable disease. Here, we test an air–liquid-interface (ALI) differentiated human nasal epithelium (HNE) culture system as a model of authentic SARS-CoV-2 infection. Progenitor cells (basal cells) were isolated from nasal turbinate brushings, expanded under conditionally reprogrammed cell (CRC) culture conditions and differentiated at ALI. Differentiated cells were inoculated with different SARS-CoV-2 clinical isolates. Infectious virus release into apical washes was determined by TCID₅₀, while infected cells were visualized by immunofluorescence and confocal microscopy. We demonstrate robust, reproducible SARS-CoV-2 infection of ALI-HNE established from different donors. Viral entry and release occurred from the apical surface, and infection was primarily observed in ciliated cells. In contrast to the ancestral clinical isolate, the Delta variant caused considerable cell damage. Successful establishment of ALI-HNE is donor dependent. ALI-HNE recapitulate key features of human SARS-CoV-2 infection of the nose and can serve as a pre-clinical model without the need for invasive collection of human respiratory tissue samples.     

Some trends in computing: The implications for simulation

This paper examines the computational environment and identifies some emerging trends and techniques that promise to have a major impact on the development of simulation software. The topics explored are single-user workstations, object-oriented programming, and expert systems. In each area, the more important underlying concepts are described briefly and the relevant terminology is defined. Their significance for simulation software development is discussed.     

Is biological treatment a viable alternative for micropollutant removal in drinking water treatment processes?

In western societies, clean and safe drinking water is often taken for granted, but there are threats to drinking water resources that should not be underestimated. Contamination of drinking water sources by anthropogenic chemicals is one threat that is particularly widespread in industrialized nations. Recently, a significant amount of attention has been given to the occurrence of micropollutants in the urban water cycle. Micropollutants are bioactive and/or persistent chemicals originating from diverse sources that are frequently detected in water resources in the pg/L to μg/L range. The aim of this review is to critically evaluate the viability of biological treatment processes as a means to remove micropollutants from drinking water resources. We first place the micropollutant problem in context by providing a comprehensive summary of the reported occurrence of micropollutants in raw water used directly for drinking water production and in finished drinking water. We then present a critical discussion on conventional and advanced drinking water treatment processes and their contribution to micropollutant removal. Finally, we propose biological treatment and bioaugmentation as a potential targeted, cost-effective, and sustainable alternative to existing processes while critically examining the technical limitations and scientific challenges that need to be addressed prior to implementation. This review will serve as a valuable source of data and literature for water utilities, water researchers, policy makers, and environmental consultants. Meanwhile this review will open the door to meaningful discussion on the feasibility and application of biological treatment and bioaugmentation in drinking water treatment processes to protect the public from exposure to micropollutants.     

Separation and identification of amino acids from lignite humic acids by thin layer chromatography

Thin layer chromatography with and without temperature gradient was used to identify ten amino acids in the humic acid hydrolysate of Rovinari lignite, using cellulose and volcanic tuff as stationary phases. The acids found were L-leucine, isoleucine, phenylalanine, L-valine, tyrosine, proline, L-alanine, glutamic acid, threonine and L-lysine.     

From projectification to programmification

This paper considers two key themes from the Rethinking Project Management Network activities: projectification and managing multiple projects. Following analysis of cases presented during network meetings, the findings are set in the context of the extant literature, and discuss the development of the concept of projectification over the past decade. Three key conclusions are drawn from this work. Firstly, projectification has considerably extended the definition of ‘a project’ way beyond the current definitions in the literature. Secondly, projectification has not been a panacea for individuals or organisations. Lastly, during the decade reviewed by this paper, we have seen the establishment of programmes and portfolios of programmes as a mechanism for managing in organisations. This represents a developed phenomenon we have termed programmification. All three of these conclusions have implications for research and practice, which are reflected in a research agenda and specific research questions.     

Using wireless technology to develop a virtual reality command and control centre

This paper investigates the applicability of wireless communication systems for use in command and control environments. Human positional data is transmitted over a wireless network. This data is then used to update a highly accurately modelled real-time 3D environment of the surroundings, with avatars positioned at the transmitted points. The data is displayed on a stereoscopic 3D screen enabling novel automatic tracking of human movement and allowing for more rapid and informed tactical decision making. The system has applicability in a variety of C4I environments, including the military and emergency services.