109 research outputs found
BER Performance of IM/DD FSO System with OOK using APD Receiver
In this paper, the performance of intensity-modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying (OOK) and avalanche photodiode (APD) receiver is observed. The gamma-gamma model is used to describe the effect of atmospheric turbulence since it provides good agreement in the wide range of atmospheric conditions. In addition, the same FSO system with equal gain combining applied at the reception is analyzed. After theoretical derivation of the expression for the bit error rate (BER), the numerical integration with previously specified relative calculation error is performed. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of the FSO link and receiver parameters on the BER performance are discussed. The results illustrate that the optimal APD gain in the minimum BER sense depends considerably on the link distance, atmospheric turbulence strength and receiver temperature. In addition, the value of this optimal gain is slightly different in the case of spatial diversity application compared with single channel reception
Influence of dietary mannanoligosaccharides on histological parameters of the jejunal mucosa and growth performance of broiler chickens
The trial involved 480 Hubbard Classic broiler chicks which were from either mannanoligosaccharide (MOS) fed breeder flock (Bio-Mos, Alltech Inc. USA at level of 1 kg/t) or control fed breeder flock (without MOS). Three groups with four replicates per treatment were formed: control fed breeders/control fed broilers (C/C); MOS fed breeders/control fed broilers (BM/C) and MOS fed breeders/MOS fed broilers (BM/BM). All chicks were fed the same basal diet, except for the inclusion of Bio-Mos (1, 0.75 and 0.5 kg/t in the starter, grower and finisher diet, respectively). The results showed a significant improvement (p<0.05) in the body weight gain with the addition of Bio-Mos in broiler feed. Feed conversion ratio was improved by 0.03 points, but the difference was not significant (P>0.05). The gut morphology examination showed that chick origin (chicks that originated from Bio-Mos fed breeders or control fed breeders) did not influence the morphological parameters of the jejunum in the broiler chickens, but addition of Bio-Mos directly to the broiler feed had a significant influence on the gut morphology and played an important role in processes of digestion and absorption, leading to improved performance.Key words: Broiler, mannanoligosaccharides, growth, jejunum, histology
Data-driven vs knowledge-driven inference of health outcomes in the ageing population: A case study
Preventive, Predictive, Personalised and Participative (P4) medicine has the potential to not only vastly improve people's quality of life, but also to significantly reduce healthcare costs and improve its efficiency. Our research focuses on age-related diseases and explores the opportunities offered by a data-driven approach to predict wellness states of ageing individuals, in contrast to the commonly adopted knowledge-driven approach that relies on easy-to-interpret metrics manually introduced by clinical experts. This is done by means of machine learning models applied on the My Smart Age with HIV (MySAwH) dataset, which is collected through a relatively new approach especially for older HIV patient cohorts. This includes Patient Related Outcomes values from mobile smartphone apps and activity traces from commercial-grade activity loggers. Our results show better predictive performance for the data-driven approach. We also show that a post hoc interpretation method applied to the predictive models can provide intelligible explanations that enable new forms of personalised and preventive medicine
Craniovertebral anomalies associated with pituitary gland duplication
Background: An extremely rare occurrence of the pituitary gland duplication inspired us to examine in detail the accompanying craniovertebral congenital anomalies in a patient involved.
Materials and methods: T1-wighted magnetic resonance imaging (MRI) was performed, as well as the multislice computerised tomography (MSCT) and MSCT angiography in our patient, as well as in a control group of 10 healthy subjects.
Results: In a 20-year-old male a double pituitary gland was identified, as well as hypothalamic enlargement, tuberomamillary fusion and hamartoma. In addition, the patient also showed a duplicated hypophyseal fossa and posterior clinoid processes, notch of the upper sphenoid, prominent inner relief of the skull, inverse shape of the foramen magnum, third occipital condyle, partial aplasia of the anterior and posterior arches of the atlas with a left arcuate foramen, duplication of the odontoid process and the C2 body, and fusion of the C2–C4 and T12–L1 vertebrae. The MSCT angiography presented a segmental dilatation of both vertebral arteries and the A2 segment of the anterior cerebral artery, as well as a duplication of the basilar artery.
Conclusions: This patient is unique due to complex craniovertebral congenital anomalies associated with a duplication of the pituitary gland
Operative treatment of supracondylar elbow fracture in a child using the percutaneous method
Supracondylar fractures are the most common elbow injuries in children and are associated with prolonged morbidity due to possible complications that can lead to deformity. The decision on the treatment method is made based on Gartland's classification (I, II, III and IV types) and the treatment can be non-operative (I and II type) and operative (III and IV type). When it comes to the percutaneous method, the main dilemma for its implementation is related to pinning from the medial side of the elbow because there is a high possibility of injury to the n. ulnaris which, according to data from the literature, occurs in some 15% of cases. The aim of treatment is pain relief and maintenance of the patient's functional status. The case presented in this paper represents a patient with whom the clinician is most likely to encounter and shows the clinical assessment of the patient's condition, the way of deciding on the treatment method and the outcome of the treatment undertaken. Agirl, 8 years old, was injured when she fell while playing. At the Department of Orthopedic Surgery and Traumatology, Clinical Hospital Center Kosovska Mitrovica, the patient was clinically and radiographically examined, and the injury was defined as a supracondylar fracture type III according to Gartland. After adequate preoperative preparation under general anesthesia, without the use of a drape - Turniquet, with the use of a C-bow, repositioning is performed and after obtaining a satisfactory position of the fragments, they are fixed percutaneously with 3 Kirschner needles, two medially and one laterally. The patient was discharged 3 days after admission with controls performed for 7 days. The Kirschner pins were removed on the 5th week after the operation and physical treatment was started, after which the movements of flexion and extension as well as pronation and supination were fully restored. Similar results are found in the literature. This information can be helpful in advising parents about what to expect after their child's injury. Also, they represent evidence of good clinical practice for orthopedic doctors and physiotherapists
Photoactivity of Immobilized Titanium Dioxide (TiO2 ) in Lindane Degradation
Introduction and study objectives: Lindane is a generic name for γ-hexachlorocyclohexane, one of the isomers from the group of Hexachlorocyclohexanes (HCH) [1]. Due to its neurotoxic activity, it had a very wide application, from agricultural to non-agricultural purposes. As a result of its lipophility, lindane can easily pass through the blood-brain barrier. The reason of his neurotoxicity is that it can interact with GABAA receptors and obstruct GABA neurotransmitter signaling in nervous system. People who have been exposed to lindane for a long time can experience serious health problems, such as: poor liver function, cardiac arrhythmias, and irregular menstruation. Due to its adverse health effect, lindane is classified as a “pregnancy category C” chemical [2]. It is also one of the Persistent Organic Pollutants (POPs) that were listed under the Annex A (elimination) of the Stockholm Convention with a specific exemption for use as a human health pharmaceutical [3]. The aim of this paper was the assessment of the immobilized titanium dioxide photocalytic properties in lindane degradation. Methodology: Spray pyrolysis method was used for a synthesis of thin titanium oxide films on the foils of the stainless steel [4]. The lindane solution was incubated with TiO2 and exposed to UV/VIS light. Aliquots were taken from the reaction mixture after 0, 2, 4, 6, 8, 10 and 12 hours. Lindane was extracted according to the EPA method 505 [5], and analyzed using an Agilent 7890A gas chromatograph (GC) connected to an electron capture detector (ECD). The GC was equipped with a Thermo Scientific™ TraceGOLD™ TG-5MT capillary column (60 m × 0.25 mm ID × 0.25 μm). The temperature program used for gas chromatography was: Initial heating temperature: 50 °C for 3 minutes, then heating at a rate of 30 °C/min to 210 °C for 20 minutes. Hydrogen with a flow rate of 60 mL/min was used as the carrier gas. Results and conclusions: Photoactivity of immobilized titanium dioxide in the degradation of lindane was measured as a percentage of lindane’s degradation compared to its initial concentration. The obtained results demonstrated that after two hours 45.32 % of lindane was degraded, while after twelve hours the percentage of degradation increased to 98.20 %. In this study we proved that the immobilized titanium dioxide can be used as a productive and fast photocatalyst for lindane photodegradation
Crystallographic Snapshots of Tyrosine Phenol-lyase Show That Substrate Strain Plays a Role in C–C Bond Cleavage
Assessment of the sensitivity of model responses to urban emission changes in support of emission reduction strategies
© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/The sensitivity of air quality model responses to modifications in input data (e.g. emissions, meteorology and boundary conditions) or model configurations is recognized as an important issue for air quality modelling applications in support of air quality plans. In the framework of FAIRMODE (Forum of Air Quality Modelling in Europe, https://fairmode.jrc.ec.europa.eu/) a dedicated air quality modelling exercise has been designed to address this issue. The main goal was to evaluate the magnitude and variability of air quality model responses when studying emission scenarios/projections by assessing the changes of model output in response to emission changes. This work is based on several air quality models that are used to support model users and developers, and, consequently, policy makers. We present the FAIRMODE exercise and the participating models, and provide an analysis of the variability of O3 and PM concentrations due to emission reduction scenarios. The key novel feature, in comparison with other exercises, is that emission reduction strategies in the present work are applied and evaluated at urban scale over a large number of cities using new indicators such as the absolute potential, the relative potential and the absolute potency. The results show that there is a larger variability of concentration changes between models, when the emission reduction scenarios are applied, than for their respective baseline absolute concentrations. For ozone, the variability between models of absolute baseline concentrations is below 10%, while the variability of concentration changes (when emissions are similarly perturbed) exceeds, in some instances 100% or higher during episodes. Combined emission reductions are usually more efficient than the sum of single precursor emission reductions both for O3 and PM. In particular for ozone, model responses, in terms of linearity and additivity, show a clear impact of non-linear chemistry processes. This analysis gives an insight into the impact of model’ sensitivity to emission reductions that may be considered when designing air quality plans and paves the way of more in-depth analysis to disentangle the role of emissions from model formulation for present and future air quality assessments.Peer reviewe
Positively selected modifications in the pore of TbAQP2 allow pentamidine to enter Trypanosoma brucei
Mutations in the Trypanosoma brucei aquaporin AQP2 are associated with resistance
to pentamidine and melarsoprol. We show that TbAQP2 but not TbAQP3 was positively selected
for increased pore size from a common ancestor aquaporin. We demonstrate that TbAQP2’s
unique architecture permits pentamidine permeation through its central pore and show how
specific mutations in highly conserved motifs affect drug permeation. Introduction of key TbAQP2
amino acids into TbAQP3 renders the latter permeable to pentamidine. Molecular dynamics
demonstrates that permeation by dicationic pentamidine is energetically favourable in TbAQP2,
driven by the membrane potential, although aquaporins are normally strictly impermeable for ionic
species. We also identify the structural determinants that make pentamidine a permeant although
most other diamidine drugs are excluded. Our results have wide-ranging implications for
optimising antitrypanosomal drugs and averting cross-resistance. Moreover, these new insights in
aquaporin permeation may allow the pharmacological exploitation of other members of this
ubiquitous gene family
Coordinate and redox interactions of epinephrine with ferric and ferrous iron at physiological pH
Coordinate and redox interactions of epinephrine (Epi) with iron at physiological pH are essential for understanding two very different phenomena - the detrimental effects of chronic stress on the cardiovascular system and the cross-linking of catecholamine-rich biopolymers and frameworks. Here we show that Epi and Fe3+ form stable high-spin complexes in the 1:1 or 3:1 stoichiometry, depending on the Epi/Fe3+ concentration ratio (low or high). Oxygen atoms on the catechol ring represent the sites of coordinate bond formation within physiologically relevant bidentate 1:1 complex. Redox properties of Epi are slightly impacted by Fe3+. On the other hand, Epi and Fe2+ form a complex that acts as a strong reducing agent, which leads to the production of hydrogen peroxide via O-2 reduction, and to a facilitated formation of the Epi-Fe3+ complexes. Epi is not oxidized in this process, i.e. Fe2+ is not an electron shuttle, but the electron donor. Epi-catalyzed oxidation of Fe2+ represents a plausible chemical basis of stress-related damage to heart cells. In addition, our results support the previous findings on the interactions of catecholamine moieties in polymers with iron and provide a novel strategy for improving the efficiency of cross-linking.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3040
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