Search

With increasing interest in constructing more three-dimensional entities, there has been growing interest in cross-coupling reactions that forge C(sp3)–C(sp3) bonds, which leads to additional challenges as it is not just a more difficult bond to construct but issues of stereocontrol also arise. Herein, we report the stereocontrolled cross-coupling of enantioenriched boronic esters with racemic allylic carbonates enabled by iridium catalysis, leading to the formation of C(sp3)–C(sp3) bonds with single or vicinal stereogenic centers. The method shows broad substrate scope, enabling primary, secondary, and even tertiary boronic esters to be employed, and can be used to prepare any of the four possible stereoisomers of a coupled product with vicinal chiral centers. The new method, which combines the simultaneous enantiospecific reaction of a chiral nucleophile with the enantioselective reaction of a chiral electrophile in a single process, offers a solution for stereodivergent cross-coupling of two C(sp3) fragments.

Soil properties can be significantly influenced by the addition of biochar and are known to enhance plant productivity and soil quality. Berseem acts as a good phytoaccumulator. The main aim of this study was to evaluate the effect of different concentrations of biochar on plant height, biomass, and chlorophyll content and on PAHs adsorption capacity at different time intervals. Sixteen treatment combinations were designed in three replicates for a total 144 pots. A soil/biochar (w/w) mixture and poly-aromatic hydrocarbon (PAH) content (50 mg kg−1naphthalene and 100 mg kg−1phenanthrene) of suitable ratio for each application was used for filling different pots, having dimensions of 19.6 cm diameter × 20.6 cm height. Various qualitative and quantitative methods were followed for further analysis of soil, plant, and biochar samples. Maximum plant height and plant biomass were observed at 5% and 10% biochar level in the soil as compared to control. Total available nutrients increased with biochar application rate. Increase in biochar concentration resulted in increased PAH adsorption capacity, thereby making it less available to cause the negative effect on plant growth parameters. Bio-concentration factor significantly decreased with increased biochar concentration in soil, i.e., from 92.5 to 5.31 in phenanthrene-contaminated soil and from 17.4 to 1.36 in mixed contaminated soil as compared to control. These results significantly prove that biochar enhanced the PAHs adsorption capacity as well as removal efficiency and crop yield. This study also shows the effectiveness of biochar on contaminant remediation with the help of Trifolium alexandrinum.

Sustainable agriculture necessitates the exploration of eco friendly materials to eradicate the pathogenic menace without causing any adverse and residual impact on the environment. Nanotechnology proposes the prodigious aptitude by developing the nanometric-materials to change the pathological scenario of seeds. In this study, zinc carbonate nanoparticles (NPs) of varying sizes (ZnC-1 NPs, ZnC-2 NPs and ZnC-3 NPs) were prepared in aqueous media under sonochemical conditions to visualize the size-dependedant antifungal potential of ZnC NP. Topo-morphological parametric details were achieved by TEM, SEM-EDS, XRD, IR and UV-visible spectroscopic techniques. In vitro suppression of pathogenic fungi of rice seeds by ZnC NPs revealed the size-dependent inhibition of mycelial growth of Fusarium fujikuroi. The nanopriming of rice seeds with ZnC-3 NPs at 150 µg/ml for 6 h caused significant reduction in seedling blight (82 ± 2%) and seed rot (81 ± 4%) relative to control, while seeds nanoprimed for 8 h resulted in augmentated percent germination (90 ± 2%), root length (13 ± 1.0 cm), shoot length (9.9 ± 0.6 cm), dry weight (0.076 ± 0.003 g) and overall vigor index (6.84 ± 0.5) when comparad to control. The enhanced internalization of zinc in ZnC-3 NPs primed seedlings, compared to hydroprimed seeds, provides the evidence for the role of nano zinc in promoting growth of nanoprimed seedlings. Inclusively, by conducting extensive field trials on rice, ZnC nanoforms can be endorsed as environmentally friendly antifungal agents and classified as “nanofungicides” in the agricultural sector.

The uncontrollable spread of the COVID-19 pandemic and countries' countervailing responses to mitigate its impact on their people led to prolonged stockouts of essential consumer products, resulting in consumer panic buying, which further exacerbated the stockout crisis. The retail stores were unable to mitigate this crisis. This study offers a conceptual framework for retail stores to become resilient to such disruptions in the future using their existing resources and capabilities. Later, we illustrate the testing of the framework using simulation methodology. The results demonstrate that stores can quickly and cost-effectively mitigate stockouts by deploying appropriate substitute products, discounts, return policies, demand containment, and effective communication with consumers. Finally, we furnish implications for supply chain resilience and retail managers and describe the study's limitations.

A unique supply chain disruption in the USA created shortages resulting in inflated prices of products regularly sourced from foreign production locations despite their availability at pre-pandemic levels at the US ports. This study uses the 'fishbone' or 'cause and effect' diagram, a graphical tool developed by Ishikawa, to analyse the underlying reasons for this unique disruption. Our analysis reveals that this disruption emerged from the interaction of lingering effects of the COVID-19 pandemic and structural limitations of US West Coast ports. Discussion of factors deemed responsible for the disruption is elucidated along with managerial implications and the study's limitations.

In the hydro power plants, mild steel pipes are used to transport river water from Dam to the turbine house. This water usually contains sand particles that are also transported through these pipelines that are observed to erode the pipelines at different locations. The present study is thus conducted to investigate the erosion phenomenon of similar sand particles on a mild steel specimen. The base material mild steel is coated with two different coating powder in three different proportions viz. 70 Al2O3 + 30 TiO2, 80 Al2O3 + 20 TiO2 and 60 Al2O3 + 40 TiO2. The experiments are performed in a slurry pot tested at 750, 1000, 1250, and 1500 rpm for 30-120 minutes. The results show that on the blending of 30% TiO2 feedstock coating powder with 70%, Al2O3 is more beneficial to improve the erosion resistance of mild steel.

Concrete is the most common material used in civil infrastructure building. However, concrete deformation such as cracks, abnormalities, or voids can develop at any time during its life cycle or during use. As a result, a tangible assessment is required to determine its strength and quality status. The most prevalent non-destructive approach for assessing the state of concrete structures is the radio frequency (RF) method. However, issues occur when the sample surface is only partially accessible. As a result, this article uses the sensor on the tested concrete to analyse RF as non-destructive testing (NDT). The concrete system is simulated using the COMSOL Multiphysics. The scattering parameters are used to analyse the dielectric characteristics of the sample using the output signal from the sensor. The value for the dielectric constant ranges from 15 to 18. The results are then verified using the Debye model to determine the concrete sample’s dielectric characteristics.

Carbon–phosphorus bond formation is significant in synthetic chemistry because phosphorus-containing compounds offer numerous indispensable biochemical roles. While there is a plethora of methods to access organophosphorus compounds, phosphonylations of readily accessible alkyl radicals to form aliphatic phosphonates are rare and not commonly used in synthesis. Herein, we introduce a novel phosphorus radical trap “BecaP” that enables facile and efficient phosphonylation of alkyl radicals under visible light photocatalytic conditions. Importantly, the ambiphilic nature of BecaP allows redox neutral reactions with both nucleophilic (activated by single-electron oxidation) and electrophilic (activated by single-electron reduction) alkyl radical precursors. Thus, a broad scope of feedstock alkyl potassium trifluoroborate salts and redox active carboxylate esters could be employed, with each class of substrate proceeding through a distinct mechanistic pathway. The mild conditions are applicable to the late-stage installation of phosphonate motifs into medicinal agents and natural products, which is showcased by the straightforward conversion of baclofen (muscle relaxant) to phaclofen (GABABantagonist).

Enantioenriched organoboron intermediates are important building blocks in organic synthesis and drug discovery. Recently, transition metal-catalyzed enantioselective 1,2-metalate rearrangements of alkenylboronates have emerged as an attractive protocol to access these valuable reagents by installing two different carbon fragments across C═C π-bonds. Herein, we report the development of an iridium-catalyzed asymmetric allylation-induced 1,2-metalate rearrangement of bicyclo[1.1.0]butyl (BCB) boronate complexes enabled by strain release, which allows asymmetric difunctionalization of C–C σ-bonds, including dicarbonation and carboboration. This protocol provides a variety of enantioenriched three-dimensional 1,1,3-trisubstituted cyclobutane products bearing a boronic ester that can be readily derivatized. Notably, the reaction gives transdiastereoisomers that result from an anti-addition across the C–C σ-bond, which is in contrast to the syn-additions observed for reactions promoted by PdII–aryl complexes and other electrophiles in our previous works. The diastereoselectivity has been rationalized based on a combination of experimental data and density functional theory calculations, which suggest that the BCB boronate complexes are highly nucleophilic and react via early transition states with low activation barriers.

Borylations of inert carbon–hydrogen bonds are highly useful for transforming feedstock chemicals into versatile organoboron reagents. Catalysis of these reactions has historically relied on precious-metal complexes, which promote dehydrogenative borylations with diboron reagents under oxidant-free conditions. Recently, photoinduced radical-mediated borylations involving hydrogen atom transfer pathways have emerged as attractive alternatives because they provide complimentary regioselectivities and proceed under metal-free conditions. However, these net oxidative processes require stoichiometric oxidants and therefore cannot compete with the high atom economy of their precious-metal-catalyzed counterparts. Herein, we report that CuCl2catalyzes radical-mediated, dehydrogenative C(sp3)–H borylations of alkanes with bis(catecholato)diboron under oxidant-free conditions. This is a result of an unexpected dual role of the copper catalyst, which promotes oxidation of the diboron reagent to generate an electrophilic bis-boryloxide that acts as an effective borylating agent in subsequent redox-neutral photocatalytic C–H borylations.

[Display omitted]

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental condition that is estimated to affect 5% of children and adolescents worldwide. The core manifestations of ADHD include impulsivity, inattentiveness and hyperactivity, with there being a high proportion of individuals also experiencing other psychiatric co-morbidities. Currently available treatments for ADHD are limited by the low adherence rates related to adverse events. However, it has been suggested that cannabis-based medicinal products (CBMPs) may be effective in the treatment of ADHD, as evidence has shown how cannabis can lead to improvements in symptoms of hyperactivity and impulsivity. However, there is still limited published data supporting its use and further randomised controlled trials are required to help establish the efficacy, safety and exact role of CBMPs for the treatment of ADHD. ADHD patients can be assessed for receiving potential treatment with CBMPs by specialist clinics, such as Sapphire Medical Clinics, in instances where they have failed to respond to their treatment.

This research plans to explore the risks of the investment claims involved in the ongoing technology transfers to COVID-19 vaccine manufacturers based on the recently approved ‘Agreement on Trade-Related Aspects of Intellectual Property Rights' (TRIPS) waiver. These investment claims are based on the various intellectual property rights protected under international investment laws. The recently approved TRIPS waiver only deals with the patent rights involved in producing the COVID-19 vaccine but does not deal with the other related intellectual property rights such as trade secrets. This work sounds the alarm of investment dispute for the mass-production of vaccines based on the TRIPS waiver. The research suggests a plan by which the Indian government can address the global issue of COVID-19 technology transfer in India.

Purpose: This article analyzes research on digital transformation in the tourism sector, providing insights into leading work, authors, journals, trends and future research opportunities. However, limited in-depth research exists on this topic, and the existing studies lack an understanding of its development, scope and relevant areas. Design/methodology/approach: The study utilized the Scopus database to identify 61 articles on digital transformation in the tourism sector. The research employed VOSviewer software to analyze publication and citation structure, incorporating bibliometric variables like co-authorship, co-citation network, keywords co-occurrence network and bibliographic coupling. Findings: The study yielded valuable insights from top-cited articles, revealing their contributions to digital transformation in tourism research. It also highlighted publication trends and the impact of authors, journals and studies and conducted co-occurrence, co-authorship and bibliographic analyses to identify key trends and issues in the tourism sector. The study calls for further examination of the digital revolution in tourism research and outlines future opportunities for researchers in this area. Research limitations/implications: To enhance the comprehensiveness of data collection, it is recommended that researchers consider including publications from databases such as WOS (Web of Science), Dimensions and PubMed in addition to the Scopus database. This broader inclusion of sources can provide different network structures and valuable insights from the field of digital transformation in the tourism sector. Originality/value: The research provides substantial value to the study of digital transformation in tourism by focusing on bibliometric data from the Scopus database for the period from 2017 to 2022. By analyzing this data, it identifies significant trends in digital transformation within tourism research. Additionally, the study uncovers new areas of digitization in the tourism sector, further enhancing its value and relevance.

Objective weight-based multi-attribute decision-making (OWMADM) methods are applied in decision situations where the weight values are not sought from decision-makers and are rather obtained based on the range or spread of attribute data. The present study develops three novel OWMADM methods, namely preference selection index proximity indexed value method (PSIPIVM), standard deviation proximity indexed value method (SDPIVM) and entropy proximity indexed value method (EPIVM), by combining the objective weights obtained through three different methods with the recently developed proximity indexed value method (PIVM), which is known to promote minimisation of the rank reversal problem. Two established criteria are adopted to evaluate the occurrence of rank reversal, one by removing the least preferred alternative from consideration while another involved splitting the considered alternatives into two sets and testing for the transitive property. The paper also attempts to identify suitable normalisation techniques for the proposed OWMADM methods to yield robust ranking orders, which may enhance the reliability of decision outcome.

High consequence supply chain disruptions adversely affect stores and consumers. The stores inherit prolonged stockouts resulting in loss of consumer trust and commitment and their patronage leading to substantial losses. Consumers feel compelled to pay inflated prices at grey markets, patronise other outlets, or learn to live without them. There is a dearth of studies offering strategies to mitigate such disruptive effects quickly and cost-effectively thereby leaving a gap in supply chain strategies, which this study attempts to fill by offering a novel implementable model using the repurposed marketing strategies. The model suggests that the stores can mitigate such disruptive impacts by regaining consumer trust and commitment. This study contributes substantively to the supply chain strategies and builds a bridge for future development and testing applications of re-purposed strategies to specific types of high consequence disruptions. This study furnishes purposeful managerial implications and directions for future research.

Surface-modified zinc sulfide nanoparticles (ZnS NPs) were prepared and their zeta potentials modulated by the topological adsorption of Zn2+and S2−ions viathe common ion adsorption property of colloids to visualize the effect of surface charge on their antifungal potential. The in vitrosuppression of Fusarium verticillioidesby ZnS©-6 NPs (ζ= +20.04 mV) revealed the charge-dependent enhancement in their antifungal potential, indicating that electrostatic interactions are their interactive mode. Specifically, the variation in the zeta potential of the fungal hyphae was measured to range from ζ= −13.20 mV to ζ= −5.34 mV during contact with the positively charged ZnS NPs. The SEM-EDS analysis and staining of the treated hyphae confirmed the association of the nanoparticles on the external surface of the hyphae, disrupting their external structure, which resulted in the leakage of their intercellular proteins, and finally their death. Nanopriming of rice seeds with ZnS©-6 NPs at 48 μg mL−1for 8 h significantly reduced the seed rot (66.62%) and seedling blight (75.27%) to the maximum extent compared to carbendazim as the standard fungicide. The enhancement in seed invigorating factors, i.e., germination (47.82%), shoot length (68.03%), root length (51.46%), dry weight (39.86%) and vigor index (68.63%), was maximum at this concentration with respect to the hydroprimed seeds (control). The positively charged ZnS©-6 NPs supported 2.5-times higher nutritional Zn modulation in the treated seedlings compared to the hydroprimed rice seeds serving as the control. Overall, these results suggest that ZnS©-6 NPs are potential dual-targeting bio-assimilative and agro-compatible nanoplatforms for constraining the growth of F. verticillioidesin rice seeds with health invigorating effects.

In this article, an improved MULTIMOORA approach is proposed for multi-attribute decision making (MADM) using the fuzzy concept, best–worst method (BWM) and half-quadratic (HQ) theory. The fuzzy concept helps to capture the vague information derived from human judgement at different stages of decision making, while BWM helps to simplify the attribute weighing. The standard MULTIMOORA method uses three utility functions, namely the ratio system (RS) utility function, reference point (RP) utility function and full multiplicative form (FMF) utility function, for evaluating the alternatives and obtaining the ranking orders using each of the utility function scores, which are consolidated using dominance theory. However, the dominance theory in the existing MULTIMOORA method has limitations, like there is no way to ascertain the trust level of the consolidated ranking and the level of consensus among the three ranking orders. Also, there is a need for multiple comparisons during aggregation, difficulty in automation, and the problem of circular reasoning. To overcome the limitations of dominance theory, a new HQ theory-based aggregation procedure has been proposed in this paper, which also has two associated indices, one to ascertain the level of consensus from the three ranking orders from MULTIMOORA and the other to ascertain the trust level or reliability of the final ranking in the aggregated ranking. The new modification is expected to add to the trustworthiness of the MULTIMOORA decision tool. The applicability of the proposed approach has been demonstrated with cases on welding process selection.

The present study focuses on analysing the impact of website quality and content on leisure traveller's hotel selection. A structured questionnaire was developed and distributed to respondents through online platform using Google Forms. Chi square test has been used for checking the association between website quality, content and leisure travellers. The findings of the study revealed that out of ten identified features of websites quality: clear language, high resolution photographs, videos of hotel products and services, user friendly and easily accessible websites, 'influence more' to leisure travellers in the selection of star category hotels of Uttar Pradesh. The findings of the study also concluded that out of ten identified features of website content; information about cleanliness and hygiene standards especially followed in the COVID pandemic, places of tourists interest in city and discounts and offers 'influence more' to leisure travellers in the selection of star category hotels of Uttar Pradesh.

This research plans to explore the risks of the investment claims involved in the ongoing technology transfers to COVID-19 vaccine manufacturers based on the recently approved ‘Agreement on Trade-Related Aspects of Intellectual Property Rights' (TRIPS) waiver. These investment claims are based on the various intellectual property rights protected under international investment laws. The recently approved TRIPS waiver only deals with the patent rights involved in producing the COVID-19 vaccine but does not deal with the other related intellectual property rights such as trade secrets. This work sounds the alarm of investment dispute for the mass-production of vaccines based on the TRIPS waiver. The research suggests a plan by which the Indian government can address the global issue of COVID-19 technology transfer in India.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has emerged as a promising imaging tool in prostate cancer diagnosis. PSMA PET/CT radiotracers are produced in-house (gallium-68, eg, 68Ga-PSMA-11) or provided by commercial entities (fluorine-18, eg, 18F-DCFPyL). Nevertheless, the cost per procedure is not well established given that current estimates have several limitations. This study aimed to establish the cost of PSMA PET/CT in Australia.

Objective: We have routinely utilized minimally invasive direct coronary artery bypass (MIDCAB) for revascularization of the left anterior descending (LAD) coronary artery. We examined how this procedure has evolved.Methods: A retrospective review was undertaken of 2,283 consecutive patients who underwent MIDCAB between 1997 and 2021. Patients were divided into 3 groups: group A from 1997 to 2002 (n= 751, 32.9%), group B from 2003 to 2009 (n= 452, 19.8%), and group C from 2009 to 2021 (n= 1,080, 47.3%). Risk profiles and short-term outcomes were analyzed for the entire cohort and for 293 propensity-matched patients drawn from each group.Results: The left internal mammary artery was harvested open in group A but with robotic assistance in group C. Thirty-day mortality was higher in group A versus group C (12 deaths, 1.6% vs 5 deaths, 0.5%, P= 0.044); this difference was negated after propensity matching. Group A had more comorbidities than group C, including peripheral vascular disease (17.7% vs 10.0%, P< 0.001), congestive heart failure (39.6% vs 18.0%, P< 0.001), and a history of stroke (17.9% vs 10.0%, P< 0.001), although diabetes mellitus was more common in group C (51.4% vs 31.0%, P< 0.001). Stroke was greater in group A (1.2% vs 0.0% vs 0.2%, respectively, P= 0.004), as was the need for prolonged ventilation (3.6% vs 0.2% vs 0.9%, respectively, P< 0.001), before and after propensity matching.Conclusions: MIDCAB patients had less comorbidities than in the past. Robot-assisted MIDCAB was associated with lower stroke risk.

Over the last decade, multiple transcatheter mitral valve repair and replacement strategies have emerged, yet there is only 1 US Food and Drug Administration approved device, the MitraClip (Abbott Vascular, Inc., Santa Clara, CA). Current guidelines support the use of the MitraClip in high or prohibitive surgical risk patients, but there are many patients that are not anatomically suited for the device. This review article discusses the approach to degenerative and functional mitral regurgitation in the high-prohibitive risk patient, how to choose transcatheter treatment options (both approved and investigational), and potential management for therapy failure.

Cardiac arrest leading to death and sudden cardiac death (SCD) may refer implicitly to situations in which death is unexpected and primarily of cardiac cause. National and international societies have published differing definitions for the various terms relating to cardiac arrest and SCD. We highlight the controversies in defining SCD, including the lack of a universal definition, the heterogeneity in the operationalization of the term “sudden,” and limitations of time-based systems of SCD classification. We discuss the importance of a standardized methodology for classifying cardiac arrest as recommended by the World Health Organization (WHO) that should include use of multisource evidence (eg, coroner, autopsy, and toxicology reports) for confirming or refuting a cardiac cause of arrest. We reveal how a universal definition of SCD has been incorrectly attributed to the WHO and how this has been perpetuated in the literature. We make the case that definitional clarity is essential to understanding epidemiology, evaluating novel treatments, forming international collaboration, and innovating public health prevention strategies. We propose a practical schema to categorize cardiac arrest events to describe and study this population more accurately.