Conjugated poly-ynes and poly(metalla-ynes) incorporating thiophene-based spacers for solar cell (SC) applications

Solar cells (SCs) are of considerable current research interest because of their potential as a clean alternative to fossil fuels. Researchers across the globe are developing novel polymeric materials with enhanced power conversion efficiency (PCE). Conjugated poly-ynes and poly(metalla-ynes) incorporating late transition metals and thiophene-based spacers have played a very important role in this strategic area of materials research. The performance of the SCs can be optimized by varying the conjugated spacers and/or the metal ions along the polymer backbone. Therefore, an analysis of structure-photovoltaic property relationships in poly-ynes and poly(metalla-ynes) is desirable as a guide for the development of new functional materials for use in SCs. Keeping the importance of this strategic topic in mind, herein we present a brief review on conjugated poly-ynes and poly(metalla-ynes) incorporating thiophene-based spacers that have potential SC applications. Attempts have been made to correlate the photovoltaic performance of the SCs to the chemical structure of thiophene-incorporated poly-ynes and poly(metalla-ynes). The performance of SCs is also strongly influenced by other factors such as morphology and device structure.</p

Evaluation of the Intestinal Bacterial Community of Local Omani and Cobb 500 Broiler Chickens Raised in an Open-Sided House Using 16S rDNA-Based Analysis

Little is known about how the intestinal bacterial microbiota differs among different strains of chickens raised in an open sided house, predominantly those with lower growth rates, such as Indigenous chickens. Ninety-one-day-old chicks of each strain of chickens were raised in an open-sided house system and fed a conventional corn-soybean meal diet from Day 0–35 days of age. The objective of this study was to assess the relative abundance of bacteria microbiota identified in the intestinal tract of local Omani and Cobb 500 broiler chickens raised in an open-sided house system using 16S rDNA-based analysis. The results obtained showed the diversity of bacterial populations in different intestinal regions of two chicken strains. Bacilli were found in higher numbers and reached 98.8% of the bacteria in the duodenum on Day 5 in Cobb 500 versus 72.5% in the Omani chickens. Local Omani chickens had significantly higher numbers of Clostridia at an early age period. On Day 5 Clostridia comprised 13.1% of the bacteria in the duodenum of local Omani chickens, versus only 0.062% in the Cobb 500. The relative abundance of the bacterial microbiota differed significantly (p &lt;0.05) across different intestinal segments of the two strains of chickens, suggesting that each region generated its bacterial community with different relative abundances

The impact of the alkyne substitution pattern and metalation on the photo-isomerization of azobenzene-based platinum(II) diynes and polyynes

Trimethylsilyl-protected dialkynes incorporating azobenzene linker groups, Me₃SiCCRCCSiMe₃ (R = azobenzene-3,3′-diyl, azobenzene-4,4′-diyl, 2,5-dioctylazobenzene-4,4′-diyl), and the corresponding terminal dialkynes, HCCRCCH, have been synthesized and characterized. The CuI-catalyzed dehydrohalogenation reaction between <i>trans</i>-[Ph­(Et₃P)₂PtCl] and the deprotected dialkynes in a 2:1 ratio in ⁱPr₂NH/CH₂Cl₂ gives the platinum­(II) diynes <i>trans</i>-[Ph­(Et₃P)₂PtCCRCCPt­(PEt₃)₂Ph], while the dehydrohalogenation polycondensation reaction between <i>trans</i>-[(ⁿBu₃P)₂PtCl₂] and the dialkynes in a 1:1 molar ratio under similar reaction conditions affords the platinum­(II) polyynes, [−Pt­(PⁿBu₃)₂–CCRCC−]_<i>n</i>. The materials have been characterized spectroscopically, with the diynes also studied using single-crystal X-ray diffraction. The platinum­(II) diynes and polyynes are all soluble in common organic solvents. Optical-absorption measurements show that the compounds incorporating the <i>para</i>-alkynylazobenzene spacers have a higher degree of electronic delocalisation than their <i>meta</i>-alkynylazobenzene counterparts. Reversible photoisomerization in solution was observed spectroscopically for the alkynyl-functionalized azobenzene ligands and, to a lesser extent, for the platinum­(II) complexes. Complementary quantum-chemical modeling was also used to analyze the optical properties and isomerization energetics

Dicopper(I) Complexes Incorporating Acetylide-functionalized Pyridinyl-based Ligands::Synthesis, Structural and Photovoltaic Studies

Heteroaryl incorporated acetylide-functionalized pyridinyl ligands (<b>L1–L6</b>) with the general formula Py-CC-Ar (Py = pyridine and Ar = <i>thiophene-2-yl</i>, 2,2′<i>-bithiophene]-5-yl</i>, 2,2′<i>:5</i>′,2″<i>-terthiophene]-5-yl</i>, <i>thieno­[2,3-<i>b</i>]­thiophen-2-yl</i>, <i>quinoline-5-yl</i>, <i>benzo­[c]­[1,2,5]­thiadiazole-5-yl</i>) have been synthesized by Pd(0)/Cu­(I)-catalyzed cross-coupling reaction of 4-ethynylpyridine and the respective heteroaryl halide. Ligands <b>L1–L6</b> were isolated in respectable yields and characterized by microanalysis, IR spectroscopy, ¹H NMR spectroscopy, and ESI-MS mass spectrometry. A series of dinuclear Cu­(I) complexes <b>1</b>–<b>10</b> have been synthesized by reacting <b>L1–L6</b> with CuI and triphenylphosphine (PPh₃) (<b>R1</b>) or with an anchored phosphine derivative, 4-(diphenylphosphino) benzoic acid (<b>R2</b>)/2-(diphenylphosphino)­benzenesulfonic acid (<b>R3</b>), in a stoichiometric ratio. The complexes are soluble in common organic solvents and have been characterized by analytical, spectroscopic, and computational methods. Single-crystal X-ray structure analysis confirmed rhomboid dimeric structures for complexes <b>1</b>, <b>2</b>, <b>4</b>, and <b>5</b>, and a polymeric structure for <b>6</b>. Complexes <b>1</b>–<b>6</b> showed oxidation potential responses close to 0.9 V vs Fc^0/+, which were chemically irreversible and are likely to be associated with multiple steps and core oxidation. Preliminary photovoltaic (PV) results of these new materials indicated moderate power conversion efficiency (PCE) in the range of 0.15–1.56% in dye-sensitized solar cells (DSSCs). The highest PCE was achieved with complex <b>10</b> bearing the sulfonic acid anchoring functionality

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Digital employee experience and organizational performance: a study of the telecommunications sector in Oman

Purpose – The study aims at assessing the effect of digital employee experience on organisational performance, particularly in the telecommunications sector in the Sultanate of Oman, using quantitative and qualitative analysis. Research methodology – The techniques used in this empirical research include scientific literature analysis, correlation analysis, multiple regression, and sentiment analysis. Findings – The results indicate that organisational performance has a higher association with elements of the digital employee experience like work environment, organisational culture, training availability, technology accessibility, digital tool usability, and leadership support and is statistically significant at the 5% level. Also, 80% of respondents were favourable or indifferent about their digital experience. Research limitations – The study exclusively covers Oman’s telecoms industry and six important digital employee experience elements, so additional factors and industries may be examined further. A direct interview may improve findings since self-reported responses from individuals with demanding work schedules may be biased. Practical implications – Telecommunication companies must increase their efforts to engage employees in the use of digital tools and encourage their employees to utilise the different digital technologies. Originality/Value – The study investigated the six elements of the digital experience of telecom employees and its impact on organisational performance with multiple regression and sentiment analysis

Metacognitive Awareness Perceptions of Students with High and Low Scores on TIMSS-Like Science Tests

The current study explores the differences in metacognitive awareness perceptions of students who had high and low scores on TIMSS-like science tests. The sample consisted of 937 Omani students, 478 in Grade Five and 459 in Grade Nine. TIMSS-like tests were specially designed for both grade levels, and students also completed a metacognitive awareness perceptions inventory which explored their use of four main skills: planning, information management strategies, debugging strategies and evaluation. MANOVA was used to analyze the data. The findings indicated that students with high scores in the TIMSS-like test out-performed students with low scores in the test on all four metacognitive skills surveyed. This was true for all three performance areas analysed: performance in the TIMSS-like test as a whole, performance in lower-level test questions and performance in higher-level test questions. These findings highlight the extent to which students’ metacognitive skills influence their performance in science tests. The study recommends that students be trained to improve their metacognitive skills, reviews several methods for doing this, and suggests that such training might better prepare them for taking science tests. However, it also notes that further research is needed to explore the impact of metacognitive training on student performance in specific science examinations such as TIMSS