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1.
Dalton Trans ; 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38973394

ABSTRACT

Polylactic acid (PLA) is a biodegradable and biocompatible polymer with versatile applications in packaging and medicine. It is derived from lactic acid and thus represents an eco-friendly option sourced from renewable raw materials. Despite its advantages, PLA exhibits few drawbacks, such as brittleness and relatively high melting and glass transition temperatures. However, these limitations can be addressed through copolymerization with other monomers like ε-caprolactone (ε-CL), resulting in a composite material with improved physical properties. This paper comprehensively reviews achievements in PLA-PCL copolymerization using organometallic catalysts, discussing scientific findings and various copolymer architectures obtained, including random or block configurations. It also demonstrates various sustainable catalysts for achieving the required microstructure under mild reaction conditions without the aid of any external initiator.

2.
Lancet ; 403(10444): 2606-2618, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38823406

ABSTRACT

BACKGROUND: Coronary computed tomography angiography (CCTA) is the first line investigation for chest pain, and it is used to guide revascularisation. However, the widespread adoption of CCTA has revealed a large group of individuals without obstructive coronary artery disease (CAD), with unclear prognosis and management. Measurement of coronary inflammation from CCTA using the perivascular fat attenuation index (FAI) Score could enable cardiovascular risk prediction and guide the management of individuals without obstructive CAD. The Oxford Risk Factors And Non-invasive imaging (ORFAN) study aimed to evaluate the risk profile and event rates among patients undergoing CCTA as part of routine clinical care in the UK National Health Service (NHS); to test the hypothesis that coronary arterial inflammation drives cardiac mortality or major adverse cardiac events (MACE) in patients with or without CAD; and to externally validate the performance of the previously trained artificial intelligence (AI)-Risk prognostic algorithm and the related AI-Risk classification system in a UK population. METHODS: This multicentre, longitudinal cohort study included 40 091 consecutive patients undergoing clinically indicated CCTA in eight UK hospitals, who were followed up for MACE (ie, myocardial infarction, new onset heart failure, or cardiac death) for a median of 2·7 years (IQR 1·4-5·3). The prognostic value of FAI Score in the presence and absence of obstructive CAD was evaluated in 3393 consecutive patients from the two hospitals with the longest follow-up (7·7 years [6·4-9·1]). An AI-enhanced cardiac risk prediction algorithm, which integrates FAI Score, coronary plaque metrics, and clinical risk factors, was then evaluated in this population. FINDINGS: In the 2·7 year median follow-up period, patients without obstructive CAD (32 533 [81·1%] of 40 091) accounted for 2857 (66·3%) of the 4307 total MACE and 1118 (63·7%) of the 1754 total cardiac deaths in the whole of Cohort A. Increased FAI Score in all the three coronary arteries had an additive impact on the risk for cardiac mortality (hazard ratio [HR] 29·8 [95% CI 13·9-63·9], p<0·001) or MACE (12·6 [8·5-18·6], p<0·001) comparing three vessels with an FAI Score in the top versus bottom quartile for each artery. FAI Score in any coronary artery predicted cardiac mortality and MACE independently from cardiovascular risk factors and the presence or extent of CAD. The AI-Risk classification was positively associated with cardiac mortality (6·75 [5·17-8·82], p<0·001, for very high risk vs low or medium risk) and MACE (4·68 [3·93-5·57], p<0·001 for very high risk vs low or medium risk). Finally, the AI-Risk model was well calibrated against true events. INTERPRETATION: The FAI Score captures inflammatory risk beyond the current clinical risk stratification and CCTA interpretation, particularly among patients without obstructive CAD. The AI-Risk integrates this information in a prognostic algorithm, which could be used as an alternative to traditional risk factor-based risk calculators. FUNDING: British Heart Foundation, NHS-AI award, Innovate UK, National Institute for Health and Care Research, and the Oxford Biomedical Research Centre.


Subject(s)
Computed Tomography Angiography , Coronary Angiography , Coronary Artery Disease , Humans , Male , Female , Middle Aged , Aged , Longitudinal Studies , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Coronary Angiography/methods , United Kingdom/epidemiology , Risk Assessment/methods , Risk Factors , Inflammation , Prognosis , Myocardial Infarction/epidemiology
3.
Dalton Trans ; 53(25): 10592-10602, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38855964

ABSTRACT

A series of tri-coordinated zinc alkyl complexes with the general molecular formula [κ2NE-{NHIRP(Ph)(E)N-Dipp}ZnEt] [R = Dipp (2,6-diisopropylphenyl), E = S (3a), Se (3b) and R = tBu (tert-butyl), E = S (4a), Se (4b)] bearing imino-phosphanamidinate chalcogenide ligands were prepared in good yields from the reaction between the protic imino-phosphanamidinate chalcogenide ligand [NHIRP(Ph)(E)NH-Dipp] [R = Dipp, E = S (1a), Se (1b) and R = tBu, E = S (2a), Se (2b)] and diethylzinc at room temperature. The molecular structures of all the zinc complexes were established by single-crystal X-ray diffraction analysis. In the solid state, all complexes exhibited a distorted trigonal planar geometry around the zinc ion. Metal-chalcogenide (Zn-S/Se) interactions were observed in the coordination sphere. These zinc alkyl complexes were employed as pre-catalysts in the hydroboration reaction of nitriles and esters to obtain the corresponding N,N-diborylamines and boronate esters, respectively, under ambient conditions. A wide substrate scope of nitriles and esters is presented.

4.
Disaster Med Public Health Prep ; 18: e82, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695200

ABSTRACT

BACKGROUND: Medical students hold significant importance, as they represent the future of healthcare provision. This study aimed to explore psychological antecedents towards the monkeypox (mpox) vaccines among postgraduate and undergraduate medical students across countries. METHODS: A cross-sectional survey was conducted among medical students aged 18 years old and above in 7 countries; Egypt, Romania, Malaysia, and Yemen, Iraq, India, and Nigeria. We used social media platforms between September 27 and November 4, 2022. An anonymous online survey using the 5C scale was conducted using snowball and convenience Sampling methods to assess the 5 psychological antecedents of vaccination (i.e., confidence, constraints, complacency, and calculation, as well as collective responsibility). RESULTS: A total of 2780 participants were recruited. Participants' median age was 22 years and 52.1% of them were males. The 5C psychological antecedents of vaccination were as follows: 55% were confident about vaccination, 10% were complacent, 12% experienced constraints, and 41% calculated the risk and benefit. Lastly, 32% were willing to be vaccinated for the prevention of infection transmission to others. The Country was a significant predictor of confidence, complacency, having constraints, and calculation domains (P < 0.001). Having any idea about the mpox vaccine was linked to 1.6 times higher odds of being more confident [OR = 1.58 (95% CI, 1.26-1.98), P < 0.001] Additionally, living in a rural area significantly increased complacency [OR = 1.42 (95% CI, 1.05-1.95), P = 0.024] as well as having anyone die from mpox [OR = 3.3 (95% CI, 1.64-6.68), P < 0.001]. Education level was associated with increased calculation [OR = 2.74 (95% CI, 1.62-4.64), P < 0.001]. Moreover, being single and having no chronic diseases significantly increased the calculation domain [OR = 1.40 (95% CI, 1.06-1.98), P = 0.02] and [OR = 1.54 (95% CI, 1.10-2.16), P = 0.012] respectively. Predictors of collective responsibility were age 31-45 years [OR = 2.89 (95% CI, 1.29-6.48), P = 0.01], being single [OR = 2.76 (95% CI, 1.94 -3.92), P < 0.001], being a graduate [OR = 1.59 (95% CI (1.32-1.92), P < 0.001], having no chronic disease [OR = 2.14 (95% CI, 1.56-2.93), P < 0.001], and not knowing anyone who died from mpox [OR = 2.54 (95% CI, 1.39-4.64), P < 0.001), as well as living in a middle-income country [OR = 0.623, (95% CI, 0.51-0.73), P < 0.001]. CONCLUSIONS: This study underscores the multifaceted nature of psychological antecedents of vaccination, emphasizing the impact of socio-demographic factors, geographic location, and awareness, as well as previous experiences on individual attitudes and collective responsibility towards vaccination.


Subject(s)
Students, Medical , Vaccination Hesitancy , Humans , Male , Cross-Sectional Studies , Students, Medical/psychology , Students, Medical/statistics & numerical data , Female , Surveys and Questionnaires , Vaccination Hesitancy/psychology , Vaccination Hesitancy/statistics & numerical data , Adult , Adolescent , Internationality
5.
Med Phys ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695825

ABSTRACT

BACKGROUND: High-dose-rate (HDR) brachytherapy (BT) has been acknowledged as a widely utilized treatment for patients with intermediate- and high-risk prostate cancer, despite its side effects such as edema, incontinence, and impotence. Nevertheless, the treatment is consistently limited by the potential danger of excessive irradiation to organs-at-risk (OARs) like the urethra, bladder, and rectum. PURPOSE: This study aims to introduce curvilinear catheter implantation in the prostate gland for HDR treatment. The objective is to improve the radiation dose distribution by offering access channels conformal to the prostate anatomy. This approach seeks to minimize toxicity to nearby OARs while utilizing a reduced number of needles, potentially leading to improved clinical outcomes. METHODS: Curvilinear catheters were first pre-planned for an anonymized patient using Oncentra treatment planning system (TPS) and hybrid inverse planning optimization (HIPO) algorithm. The trajectories of the catheters were then analyzed using MATLAB to extract their radius of curvature. Tendon-driven active needles were then used to implant curvilinear catheters inside an anthropomorphic phantom. RESULTS: Proposed curvilinear catheter implantation resulted in significant improvement in terms of dosimetric constraints to the OARs and coverage to the prostate. Tendon-driven active needles were shown to be capable of realizing the required pre-planned curvatures inside prostate. It was shown that the active needle can realize a desired radius of curvature and a desired trajectory with an average accuracy of 9.1 ± 8.6  and 1.27 ± 0.50 mm in air and inside a tissue-mimicking phantom, respectively. CONCLUSION: This work demonstrates the feasibility of using tendon-driven active curvilinear catheter implantation in prostate to improve the outcomes of HDR-BT via improved radiation dose distribution to the prostate and reduced toxicity to the OARs.

6.
Chem Commun (Camb) ; 60(42): 5542-5545, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38699830

ABSTRACT

Unprecedented ring-opening polymerization of quinazolinones to produce novel polyacylamidines, led by a unique cooperation between a cesium metal center and imino-phosphanamidinate ligand, was developed. Morphological studies revealed the formation of a unique macromolecular assembly producing nanofibers in the absence of a templating agent with excellent control of molecular weights and polydispersity index.

7.
Rev Med Virol ; 34(3): e2541, 2024 May.
Article in English | MEDLINE | ID: mdl-38743385

ABSTRACT

As the mankind counters the ongoing COVID-19 pandemic by the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), it simultaneously witnesses the emergence of mpox virus (MPXV) that signals at global spread and could potentially lead to another pandemic. Although MPXV has existed for more than 50 years now with most of the human cases being reported from the endemic West and Central African regions, the disease is recently being reported in non-endemic regions too that affect more than 50 countries. Controlling the spread of MPXV is important due to its potential danger of a global spread, causing severe morbidity and mortality. The article highlights the transmission dynamics, zoonosis potential, complication and mitigation strategies for MPXV infection, and concludes with suggested 'one health' approach for better management, control and prevention. Bibliometric analyses of the data extend the understanding and provide leads on the research trends, the global spread, and the need to revamp the critical research and healthcare interventions. Globally published mpox-related literature does not align well with endemic areas/regions of occurrence which should ideally have been the scenario. Such demographic and geographic gaps between the location of the research work and the endemic epicentres of the disease need to be bridged for greater and effective translation of the research outputs to pubic healthcare systems, it is suggested.


Subject(s)
Bibliometrics , Humans , Disease Outbreaks/prevention & control , Animals , Mpox (monkeypox)/epidemiology , Mpox (monkeypox)/transmission , Mpox (monkeypox)/prevention & control , Mpox (monkeypox)/virology , COVID-19/transmission , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/virology , SARS-CoV-2 , Zoonoses/epidemiology , Zoonoses/virology , Zoonoses/transmission , Zoonoses/prevention & control , Pandemics/prevention & control
8.
ACS Omega ; 9(13): 14860-14866, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38585097

ABSTRACT

In the current research, dye-embedded polylactic acid (PLA) conjugate materials were synthesized using one-pot ring-opening polymerization (ROP), i.e., (dtHPLA) (2-[(2,4,6-trimethylphenyl) imino]-1(2H)-acenaphthylenone-reduced-PLA) and (dmHPLA) (monoiminoacenaphtheneone-reduced-PLA), and then, nanoparticles (NPs) were engineered in the size range of 150 ± 30 nm. P(dtHPLA) NPs were employed in the treatment of melanoma, an aggressive type of skin cancer, which mandates the development of novel techniques to enhance healing outcomes and eliminate adverse effects related to existing treatments. In addition to exhibiting strong intracellular absorption in the spheroid model, the P(dtHPLA) NPs exhibited a strong cytotoxic effect on B16F10 cells, which resulted in oxidative stress from the generation of reactive oxygen species (ROS) and cell death. Additionally, a live/dead experiment using P(dtHPLA) NPs revealed a notable reduction in cell viability.

9.
Org Biomol Chem ; 22(15): 3053-3058, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38545870

ABSTRACT

We report a competent and selective hydrosilylation of nitriles and tertiary amides catalyzed by the readily available zinc bis(hexamethyldisilazide) under solvent-free and mild conditions, making it a sustainable and desirable alternative to existing methods. Both protocols afforded high conversion, superior selectivity, and a broad substrate scope, from electron-withdrawing to electron-donating and heterocyclic substitutions.

10.
J Surg Case Rep ; 2024(2): rjae037, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38328454

ABSTRACT

Lipomas are common benign mesenchymal tumours, whereas lipomatoses are uncommon. Familial multiple lipomatosis (FML) is a rare syndrome characterized by multiple usually painless lipomas which may be associated with other conditions. FML is considered to be genetic, with various patterns of inheritance suggested. In this case report, we described a case of multiple familial lipomatosis that was misdiagnosed as dercum's disease.

12.
Appl Opt ; 63(1): 159-166, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38175017

ABSTRACT

A fiber-connectorized K-band integrated-optics two-telescope beam combiner was developed for long-baseline interferometry at the CHARA telescope array utilizing the ultrafast laser inscription (ULI) technique. Single-mode waveguide insertion losses were measured to be ∼1.1d B over the 2-2.3 µm window. The development of asymmetric directional couplers enabled the construction of a beam combiner that includes a 50:50 coupler for interferometric combination and two ∼75:25 couplers for photometric calibration. The visibility of the bare beam combiner was measured at 87% and then at 82% after fiber-connectorization by optimizing the input polarization. These results indicate that ULI technique can fabricate efficient fiber-connectorized K-band beam combiners for astronomical purposes.

13.
Adv Radiat Oncol ; 9(1): 101313, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38260218

ABSTRACT

Purpose: Stereotactic body radiation therapy (SBRT) is considered the standard of care for medically inoperable early-stage non-small cell lung cancer. There is mixed evidence on the prognostic significance of tumor metabolic activity assessed by positron emission tomography combined with computed tomography (PET/CT) using F-18 fluorodeoxyglucose (FDG). The objectives of this study were to evaluate the maximum standardized uptake value (SUVmax) pretreatment and at 3 and 6 months after SBRT for prediction of tumor control and survival outcomes. Methods and Materials: Consecutive patients from a single institution with T12N0M0 non-small cell lung cancer receiving primary treatment with SBRT with pretreatment FDG-PET/CT (n = 163) and follow-up FDG-PET/CT at 3 or 6 months (n = 71) were included. Receiver operator characteristic analysis was performed to dichotomize variables for Kaplan-Meier survival analysis. Multivariate analysis was performed with Cox proportional hazards regression. Results: Median follow-up was 19 months. For the whole cohort, 1-year and 2-year local control, progression-free survival (PFS), and overall survival (OS) were 95.0% and 80.3%, 87.1% and 75.4%, and 67.0% and 49.6% respectively. The following pre-SBRT SUVmax cutoffs were significant: SUV > 4.0 for distant failure-free survival (adjusted hazard ratio [aHR], 3.33, P = .006), >12.3 for PFS (aHR, 2.80, P = .011), and >12.6 for OS (aHR, 3.00, P = .003). SUVmax decreases of at least 45% at 3 months (aHR, 0.15, P = .018), and 53% at 6 months (aHR, 0.12, P = .046) were associated with improved local failure-free survival. Conclusions: Pre-SBRT SUVmax cutoffs can predict distant failure, PFS, and OS. At both 3 and 6 months after SBRT, cutoffs for percentage change in SUVmax can potentially stratify risk of local recurrence.

14.
Radiat Res ; 201(1): 55-70, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38059553

ABSTRACT

Currently, no radioprotectors have been approved to mitigate hematopoietic injury after exposure to ionizing radiation. Acute ionizing radiation results in damage to both hematopoietic and immune system cells. Pre-exposure prophylactic agents are needed for first responders and military personnel. In this study, the ability of gamma-tocotrienol (GT3), a promising radioprotector and antioxidant, to ameliorate partial-body radiation-induced damage to the hematopoietic compartment was evaluated in a nonhuman primate (NHP) model. A total of 15 rhesus NHPs were divided into two groups, and were administered either GT3 or vehicle 24 h prior to 4 or 5.8 Gy partial-body irradiation (PBI), with 5% bone marrow (BM) sparing. Each group consisted of four NHPs, apart from the vehicle-treated group exposed to 5.8 Gy, which had only three NHPs. BM samples were collected 8 days prior to irradiation in addition to 2, 7, 14, and 30 days postirradiation. To assess the clonogenic ability of hematopoietic stem and progenitor cells (HSPCs), colony forming unit (CFU) assays were performed, and lymphoid cells were immunophenotyped using flow cytometry. As a result of GT3 treatment, an increase in HSPC function was evident by an increased recovery of CFU-granulocyte macrophages (CFU-GM). Additionally, GT3 treatment was shown to increase the percentage of CD34+ cells, including T and NK-cell subsets. Our data further affirm GT3's role in hematopoietic recovery and suggest the need for its further development as a prophylactic radiation medical countermeasure.


Subject(s)
Chromans , Radiation-Protective Agents , Animals , Macaca mulatta , Radiation-Protective Agents/pharmacology , Vitamin E/pharmacology , Bone Marrow/radiation effects
16.
Curr Pain Headache Rep ; 28(1): 27-35, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38010488

ABSTRACT

PURPOSE OF REVIEW: Osteoarthritis (OA) is a prevalent and debilitating condition characterized by joint degeneration and pain. Current treatment options aim to alleviate symptoms and slow disease progression but lack curative potential. Stem cell therapies have emerged as a promising alternative. This article explores the epidemiology, pathophysiology, clinical manifestations of hip and knee OA, and the evolving role of stem cell therapies in their treatment. RECENT FINDINGS: The global prevalence of OA, with knee OA being the most common form, has fueled the demand for stem cell therapies. Despite limited robust evidence supporting their efficacy, clinical trials investigating stem-cell treatments for OA have reported encouraging radiological and clinical improvements. Stem cell therapies offer potential disease-modifying benefits through immunomodulatory actions, growth factor secretion, and chondrogenic capabilities. Adipose-derived mesenchymal stem cells (ADMSCs) have shown promise in clinical trials for OA treatment, offering potential pain relief and functional improvement. ADMSCs possess advantages such as accessibility and a favorable safety profile, making them a viable option for OA management. Although other stem-cell types, including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), have been used in OA treatment, ADMSCs have demonstrated superior outcomes. By providing a comprehensive overview of the evolving landscape of stem cell therapies for hip and knee OA, this article highlights the potential of stem-cell treatments to address the limitations of current therapies. However, further research is required to establish their long-term efficacy, identify optimal stem-cell types, and develop standardized protocols.


Subject(s)
Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Osteoarthritis, Knee , Humans , Osteoarthritis, Knee/therapy , Mesenchymal Stem Cell Transplantation/methods , Pain
17.
Curr Pain Headache Rep ; 28(1): 37-45, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38032538

ABSTRACT

PURPOSE OF REVIEW: The surge in orthopedic surgeries strains the US healthcare system, necessitating innovative rehabilitation solutions. This review examines the potential of virtual reality (VR)-based interventions for orthopedic rehabilitation. RECENT FINDINGS: The effectiveness of VR-based interventions in orthopedic surgery patients is scrutinized. While some studies suggest better patient-reported outcomes and satisfaction, mixed results emerge from others, demonstrating comparable or varied results compared to traditional rehabilitation. The underlying mechanisms of VR-based rehabilitation are elucidated, showing its positive impact on proprioception, pain management, agency, and balance. Challenges of unfamiliarity, patient engagement, and drop-out rates are identified, emphasizing the need for tailored approaches. VR technology's immersive environments and multisensory experiences offer a novel approach to addressing functional deficits and pain post-surgery. The conclusion drawn is that VR-based rehabilitation complements rather than replaces conventional methods, potentially aiding in pain reduction and functional improvement. VR-based rehabilitation holds promise for enhancing orthopedic surgery outcomes, presenting a dynamic approach to recovery. Its potential to reshape healthcare delivery and reimbursement structures underscores its significance in modern healthcare. Overall, VR-based rehabilitation offers a promising avenue for optimizing postoperative recovery in orthopedic surgery patients.


Subject(s)
Orthopedic Procedures , Virtual Reality , Humans , Pain , Pain Management
18.
Am J Otolaryngol ; 45(2): 104186, 2024.
Article in English | MEDLINE | ID: mdl-38101136

ABSTRACT

INTRODUCTION: Acute otitis media is one of the most common reasons for pediatric medical visits in the United States. Additionally, past studies have linked food insecurity and malnutrition with increased infections and worse health outcomes. However, there is a lack of information on the risk factors for food insecurity in specific patient populations, including the pediatric recurrent acute otitis media (RAOM) population. METHODS: The 2011 to 2018 National Health Interview Survey (NHIS) datasets were used to obtain a national estimate of the presentation of food insecurity within pediatric patients with RAOM. Relevant sociodemographic information and prevalence were identified. A multivariable logistic regression model was used to determine sociodemographic risk factors. Calculations were conducted using R with the "survey" package to account for the clustering and sampling of the NHIS. RESULTS: Of 3844 children with RAOM who responded to the food insecurity module, 20.8 % (19.0-22.6 %) were food insecure. Age, race/ethnicity, percentage of federal poverty level status, insurance status, and self-reported health status were significant and were not independent of food insecurity status. Using multivariable regression, this study found the following sociodemographic risk factors: age 6-10 and age > 10 (reference: age 0-2); Black (reference: Non-Hispanic White); 100 % to 200 % and <100 % federal poverty level (reference: >200 % federal poverty level); public insurance or uninsured status (reference: private insurance); and poor to fair self-reported health status (reference: good to excellent). DISCUSSION: Children with RAOM who were older, Black, less insured, living in lower-income households, and of poorer health had a greater association with being food insecure. Due to the frequency of RAOM pediatric visits, identifying at-risk groups as well as incorporating food insecurity screening and food referral programs within clinical practice can enable otolaryngologists to reduce disparities and improve outcomes in a targeted approach.


Subject(s)
Ethnicity , Otitis Media , Child , Humans , United States/epidemiology , Infant, Newborn , Infant , Child, Preschool , Poverty , Otitis Media/epidemiology , Risk Factors , Food Insecurity
19.
Chem Rev ; 123(23): 13323-13373, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38048165

ABSTRACT

The coordination chemistry of bis(phosphinimino)methanide ligands is widespread and accompanies a large number of metal ions in the periodic table ranging from lithium to neptunium. This unique class of ligand systems show copious coordination chemistry with the main-group, transition, rare-earth, and actinide metals and are considered to be among the most attractive ligand systems to researchers. The bis(phosphinimino)methanide metal complexes offer an extensive range of applications in various fields and have been demonstrated as one of the universal ligand systems to stabilize the metal ions in not only their usual but also their unusual oxidation states. The main-group and transition metal chemistry using bis(phosphinimino)methanides as ligands was last updated almost a decade ago. In this review, we provide a comprehensive overview of various state-of-the-art bis(phosphinimino)methanide-supported metal complexes by dealing with their synthesis, characterization, reactivity, and catalytic studies which were not included in the last critical reviews.

20.
Stat Appl Genet Mol Biol ; 22(1)2023 01 01.
Article in English | MEDLINE | ID: mdl-38073574

ABSTRACT

Allele-sharing statistics for a genetic locus measure the dissimilarity between two populations as a mean of the dissimilarity between random pairs of individuals, one from each population. Owing to within-population variation in genotype, allele-sharing dissimilarities can have the property that they have a nonzero value when computed between a population and itself. We consider the mathematical properties of allele-sharing dissimilarities in a pair of populations, treating the allele frequencies in the two populations parametrically. Examining two formulations of allele-sharing dissimilarity, we obtain the distributions of within-population and between-population dissimilarities for pairs of individuals. We then mathematically explore the scenarios in which, for certain allele-frequency distributions, the within-population dissimilarity - the mean dissimilarity between randomly chosen members of a population - can exceed the dissimilarity between two populations. Such scenarios assist in explaining observations in population-genetic data that members of a population can be empirically more genetically dissimilar from each other on average than they are from members of another population. For a population pair, however, the mathematical analysis finds that at least one of the two populations always possesses smaller within-population dissimilarity than the value of the between-population dissimilarity. We illustrate the mathematical results with an application to human population-genetic data.


Subject(s)
Genetics, Population , Humans , Alleles , Gene Frequency , Genotype
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