Novel palladium(II) complex derived from mixed ligands of dithizone and triphenylphosphine synthesis, characterization, crystal structure, and DFT study

ABSTRACT. A novel distorted square-planar palladium(II) complex of the type [Pd(Hdz)(PPh3)Cl], where (Hdz = dithizone mono deprotonate and PPh3 = triphenylphosphine), was synthesized in dichloromethane reactions between PdCl2 and a mixture of Hdz and PPh3. The new Pd(II) complex has been identified by FT-IR, electronic spectra, DFT calculations, molar conductivity, and single-crystal X-ray diffraction. An X-ray diffraction study revealed the structure of this complex, indicating distorted square planar coordination geometry around the Pd(II) ion by N, S, P, and Cl donor atoms. XRD analysis has also shown that the Pd(II) complex contains one five-membered ring formed by the coordination of the Hdz ligand through the nitrogen and sulfur atoms to the palladium metal center. To comprehend the strength of nucleophilic and electrophilic attack between the ligands and metal ions, the natural bond orbital (NBO) was used. Finally, density functional theory (DFT) was used to show the molecular reactivity and stability of the ligands and palladium complex.   KEY WORDS: Palladium(II), Dithizone mono deprotonated, Distorted square planar geometry, NBO analysis, DFT calculations Bull. Chem. Soc. Ethiop. 2022, 36(3), 617-626.                                                               \ DOI: https://dx.doi.org/10.4314/bcse.v36i3.11                                                     &nbsp

Effect of age on fatty infiltration of supraspinatus muscle after experimental tendon release in rats

Rotator cuff tendon tear is a leading cause for atrophy, fibrosis and fatty infiltration of the rotator cuff muscles. The pathophysiology of fatty muscle infiltration is not well understood. An animal model suited to study cellular and molecular mechanisms would therefore be desirable. While a rat model has been established for chronic rotator cuff tendon pathology, sufficient and easily identifiable fatty infiltration of the muscle has not yet been shown in rats. As younger animals regenerate better, we hypothesized that the absence of a sufficient amount of fatty infiltration in previous experiments was due to the selection of young animals and that older animals would exhibit higher amounts of fatty infiltration after tendon tear. FINDINGS: The supraspinatus tendon was released using tenotomy in 3 young (6 weeks old) and in 3 aged (24 months old) Sprague Dawley rats (group I and II). Another 3 aged (24 months old) rats underwent sham surgery and served as a control group (group III). In group I and II retraction of the musculotendinous unit was allowed for 6 weeks. All animals were sacrificed 6 weeks after surgery and the supraspinatus muscles were harvested. Each sample was examined for fatty infiltration of the muscle by histological methods and micro-CT. In histology, fat cells were counted with a 10-fold magnification in 6 fields of view twice. An adjusted measurement setup was developed for the use of micro-CT to quantify the absorption coefficient of the muscle as a reciprocal indicator for fatty infiltration, based on the established procedure for quantification of fatty infiltration on CT in humans.Tenotomy resulted in an insignificant increase of fat cells in histological sections in both, aged and young rats. Micro-CT was able to quantify small differences in the absorption coefficients of muscle samples; the absorption coefficient was 8.1% ± 11.3% lower in retracted muscles (group I and II) compared with the control (group III), indicating a tendency towards a higher amount of intra- and/or extracellular fat. Absorption was 4.28% ± 3.2% higher in aged compared with young muscles; however, this difference could not be confirmed by histology. CONCLUSIONS: Substantial fatty muscle infiltration following chronic retraction after supraspinatus tenotomy could be documented histologically neither in young nor aged rats. Although micro-CT was able to reveal minor differences in absorption between the studied groups, the differences were too small to make the rat supraspinatus model interesting to study fatty infiltration of the chronically retracted muscle

Self-Amplifying Pestivirus Replicon RNA Encoding Influenza Virus Nucleoprotein and Hemagglutinin Promote Humoral and Cellular Immune Responses in Pigs.

Self-amplifying replicon RNA (RepRNA) promotes expansion of mRNA templates encoding genes of interest through their replicative nature, thus providing increased antigen payloads. RepRNA derived from the non-cytopathogenic classical swine fever virus (CSFV) targets monocytes and dendritic cells (DCs), potentially promoting prolonged antigen expression in the DCs, contrasting with cytopathogenic RepRNA. We engineered pestivirus RepRNA constructs encoding influenza virus H5N1 (A/chicken/Yamaguchi/7/2004) nucleoprotein (Rep-NP) or hemagglutinin (Rep-HA). The inherent RNase-sensitivity of RepRNA had to be circumvented to ensure efficient delivery to DCs for intracellular release and RepRNA translation; we have reported how only particular synthetic delivery vehicle formulations are appropriate. The question remained concerning RepRNA packaged in virus replicon particles (VRPs); we have now compared an efficient polyethylenimine (PEI)-based formulation (polyplex) with VRP-delivery as well as naked RepRNA co-administered with the potent bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) adjuvant. All formulations contained a Rep-HA/Rep-NP mix, to assess the breadth of both humoral and cell-mediated defences against the influenza virus antigens. Assessment employed pigs for their close immunological relationship to humans, and as natural hosts for influenza virus. Animals receiving the VRPs, as well as PEI-delivered RepRNA, displayed strong humoral and cellular responses against both HA and NP, but with VRPs proving to be more efficacious. In contrast, naked RepRNA plus c-di-AMP could induce only low-level immune responses, in one out of five pigs. In conclusion, RepRNA encoding different influenza virus antigens are efficacious for inducing both humoral and cellular immune defences in pigs. Comparisons showed that packaging within VRP remains the most efficacious for delivery leading to induction of immune defences; however, this technology necessitates employment of expensive complementing cell cultures, and VRPs do not target human cells. Therefore, choosing the appropriate synthetic delivery vehicle still offers potential for rapid vaccine design, particularly in the context of the current coronavirus pandemic

Financing Direct Democracy: Revisiting the Research on Campaign Spending and Citizen Initiatives

The conventional view in the direct democracy literature is that spending against a measure is more effective than spending in favor of a measure, but the empirical results underlying this conclusion have been questioned by recent research. We argue that the conventional finding is driven by the endogenous nature of campaign spending: initiative proponents spend more when their ballot measure is likely to fail. We address this endogeneity by using an instrumental variables approach to analyze a comprehensive dataset of ballot propositions in California from 1976 to 2004. We find that both support and opposition spending on citizen initiatives have strong, statistically significant, and countervailing effects. We confirm this finding by looking at time series data from early polling on a subset of these measures. Both analyses show that spending in favor of citizen initiatives substantially increases their chances of passage, just as opposition spending decreases this likelihood

Investigating the role of auditory and visual sensory inputs for inducing relaxation during virtual reality stimulation

Stress is a part of everyday life which can be counteracted by evoking the relaxation response via nature scenes presented using immersive virtual reality (VR). The aim of this study was to determine which sensory aspect of immersive VR intervention is responsible for the greatest relaxation response. We compared four conditions: auditory and visual combined (audiovisual), auditory only, visual only, and no artificial sensory input. Physiological changes in heart rate, respiration rate, and blood pressure were recorded, while participants reported their preferred condition and awareness of people, noise, and light in the real-world. Over the duration of the stimulation, participants had the lowest heart rate during the audiovisual and visual only conditions. They had the steadiest decrease in respiration rate and the lowest blood pressure during the audiovisual condition, compared to the other conditions, indicating the greatest relaxation. Moreover, ratings of awareness indicated that participants reported being less aware of their surroundings (i.e., people, noise, light, real environment) during the audiovisual condition versus the other conditions (p < 0.001), with a preference for audiovisual inputs. Overall, the use of audiovisual VR stimulation is more effective at inducing a relaxation response compared to no artificial sensory inputs, or the independent inputs

Eccrine porocarcinoma of the head: An important differential diagnosis in the elderly patient

Background: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland, characterized by a broad spectrum of clinicopathologic presentations. Surprisingly, unlike its benign counterpart eccrine poroma, eccrine porocarcinoma is seldom found in areas with a high density of eccrine sweat glands, like the palms or soles. Instead, eccrine porocarcinoma frequently occurs on the lower extremities, trunk and abdomen, but also on the head, resembling various other skin tumors, as illustrated in the patients described herein. Observations: We report 5 cases of eccrine porocarcinoma of the head. All patients were initially diagnosed as having epidermal or melanocytic skin tumors. Only after histopathologic examination were they classified as eccrine porocarcinoma, showing features of epithelial tumors with abortive ductal differentiation. Characteristic clinical, histopathologic and immunohistochemical findings of eccrine porocarcinomas are illustrated. Conclusion: Eccrine porocarcinomas are potentially fatal adnexal malignancies, in which extensive metastatic dissemination may occur. Porocarcinomas are commonly overlooked, or misinterpreted as squamous or basal cell carcinomas as well as other common malignant and even benign skin tumors. Knowledge of the clinical pattern and histologic findings, therefore, is crucial for an early therapeutic intervention, which can reduce the risk of tumor recurrence and serious complications. Copyright (c) 2008 S. Karger AG, Basel

Data-driven honeybee antennal lobe model suggests how stimulus-onset asynchrony can aid odour segregation

Insects have a remarkable ability to identify and track odour sources in multi-odour backgrounds. Recent behavioural experiments show that this ability relies on detecting millisecond stimulus asynchronies between odourants that originate from different sources. Honeybees, Apis mellifera , are able to distinguish mixtures where both odourants arrive at the same time (synchronous mixtures) from those where odourant onsets are staggered (asynchronous mixtures) down to an onset delay of only 6 ms. In this paper we explore this surprising ability in a model of the insects' primary olfactory brain area, the antennal lobe. We hypothesize that a winner-take-all inhibitory network of local neurons in the antennal lobe has a symmetry-breaking effect, such that the response pattern in projection neurons to an asynchronous mixture is different from the response pattern to the corresponding synchronous mixture for an extended period of time beyond the initial odourant onset where the two mixture conditions actually differ. The prolonged difference between response patterns to synchronous and asynchronous mixtures could facilitate odour segregation in downstream circuits of the olfactory pathway. We present a detailed data-driven model of the bee antennal lobe that reproduces a large data set of experimentally observed physiological odour responses, successfully implements the hypothesised symmetry-breaking mechanism and so demonstrates that this mechanism is consistent with our current knowledge of the olfactory circuits in the bee brain

Dietary options to reduce the environmental impact of milk production

A range of options was explored to test the hypothesis that diets for dairy cows could be formulated to reduce the carbon footprint (CFP) of feed, increase efficiency of conversion of potentially human-edible feed into milk, increase nitrogen use efficiency (NUE) and reduce methane (CH4) emissions per kg milk. Diets based on grazed grass, grass silage, maize silage or straw, supplemented with raw material feeds, were formulated to meet requirements for metabolizable energy and metabolizable protein for a range of daily milk yields. At similar levels of milk yield, NUE, predicted CH4 emissions and diet CFP were generally higher for diets based on maize silage than for those based on grazed grass, grass silage or straw. Predicted CH4 emissions and human-edible proportion decreased, while NUE increased with the increasing level of milk yield. It is concluded that there is potential to reduce the environmental impact of milk production by altering diet formulation, but the extent to which this might occur is likely to depend on availability of raw material feeds with low CFPs

Agricultural climate change mitigation : Carbon calculators as a guide for decision making

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Agricultural Sustainability on 9 November 2017, available online: https://doi.org/10.1080/14735903.2017.1398628. Under embargo. Embargo end date: 9 November 2018.The dairy industry is receiving considerable attention in relation to both its significant greenhouse gas (GHG) emissions, and it’s potential for reducing those emissions, contributing towards meeting national targets and driving the industry towards sustainable intensification. However, the extent to which improvements can be made is dependent on the decision making processes of individual producers, so there has been a proliferation of carbon accounting tools seeking to influence those processes. This paper evaluates the suitability of such tools for driving environmental change by influencing on-farm management decisions. Seven tools suitable for the European dairy industry were identified, their characteristics evaluated, and used to process data relating to six scenario farms, emulating process undertaken in real farm management situations. As a result of the range of approaches taken by the tools, there was limited agreement between them as to GHG emissions magnitude, and no consistent pattern as to which tools resulted in the highest/lowest results. Despite this it is argued, that as there was agreement as to the farm activities responsible for the greatest emissions, the more complex tools were still capable of performing a ‘decision support’ role, and guiding management decisions, whilst others could merely focus attention on key issues.Peer reviewe

Prothrombinase-Induced Clotting Time to Measure Drug Concentrations of Rivaroxaban, Apixaban, and Edoxaban in Clinical Practice: A Cross-Sectional Study.

Prothrombinase-induced clotting time (PiCT) is proposed as a rapid and inexpensive laboratory test to measure direct oral anticoagulant (DOAC) drug levels. In a prospective, multicenter cross-sectional study, including 851 patients, we aimed to study the accuracy of PiCT in determining rivaroxaban, apixaban, and edoxaban drug concentrations and assessed whether clinically relevant drug levels could be predicted correctly. Citrated plasma samples were collected, and the Pefakit® PiCT was utilized. Ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to measure drug concentrations. Cut-off levels were established using receiver-operating characteristics curves. We calculated sensitivities and specificities with respect to clinically relevant drug concentrations. Spearman's correlation coefficient between PiCT and drug concentrations was 0.85 in the case of rivaroxaban (95% CI 0.82, 0.88), 0.66 for apixaban (95% CI 0.60, 0.71), and 0.78 for edoxaban (95% CI 0.65, 0.86). The sensitivity to detect clinically relevant drug concentrations was 85.1% in the case of 30 µg L-1 (95% CI 82.0, 87.7; specificity 77.9; 72.1, 82.7), 85.7% in the case of 50 µg L-1 (82.4, 88.4; specificity 77.3; 72.5, 81.5), and 85.1% in the case of 100 µg L-1 (80.9, 88.4; specificity 73.2%; 69.1, 76.9). In conclusion, the association of PiCT with DOAC concentrations was fair, and the majority of clinically relevant drug concentrations were correctly predicted