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1.
Cureus ; 16(8): e66318, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39238678

RESUMO

OBJECTIVE: This study aimed to investigate perineal wound healing rates following abdominoperineal resection (APR) or extralevator abdominoperineal excision (ELAPE) for rectal cancer, with a focus on identifying associated risk factors and outcomes. METHODOLOGY: A retrospective analysis was conducted on patients undergoing APR or ELAPE for rectal cancer in a tertiary centre between 2013 and 2020. Data on demographics, comorbidities, surgical techniques, and perineal wound outcomes were collected and analyzed using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 27.0, Armonk, NY). Statistical significance was set at p<0.05. RESULTS: A total of 87 patients were included, with a mean age of 64 years and the majority being male (66.7%). Neoadjuvant radiotherapy was administered in 87.4% of cases. Perineal wound complications were documented in 52 cases (59.8%), with major complications observed in 11 cases (12.6%). Healing within six months was achieved in 48 patients (55.2%), while 39 patients (44.8%) developed chronic perineal wounds. Logistic regression analysis revealed omentoplasty as a significant predictor of perineal wound healing rate showing a significant negative association (p=0.0289). CONCLUSION: Perineal wound healing rates following APR or ELAPE varied. While most patients achieved complete healing, chronic perineal wounds presented challenges. Omentoplasty was associated with lower odds of healing, suggesting the need for further investigation into its role. These findings underscore the importance of patient counselling and multidisciplinary management strategies to optimize outcomes in rectal cancer surgery.

3.
Int J Biol Macromol ; 280(Pt 1): 135656, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39278436

RESUMO

The study aims to improve the viability and stability of resveratrol by encapsulating metal-based biocompatible nanocarrier for mitochondrial-targeted delivery and breast cancer treatment. For this purpose, sodium alginate coated silver nanoparticles were synthesized by in-situ reduction of silver nitrate using sodium borohydride. The prepared nanoparticles and resveratrol-loaded nanoparticles were characterized by utilizing the following instruments including X-ray diffraction (XRD), UV visible spectroscopy, Photoluminescence (PL) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared (FTIR), Raman spectroscopy, Zeta potential. The dialysis method revealed increased resveratrol release in pH 5 phosphate buffer. The incorporation of resveratrol significantly stimulated the antioxidant activity of sodium alginate coated silver nanoparticles. MTT assay was employed to evaluate the biocompatibility and anticancer potential of developed sodium alginate coated silver nanoparticles and resveratrol-loaded nanoparticles with increasing concentrations against normal HaCaT and breast cancer MCF-7 cell lines respectively. Further, the apoptotic morphology of MCF-7 cells treated with sodium alginate coated nanoparticles and resveratrol loaded nanoparticles was evaluated by AO/EtBr staining and apoptosis was demonstrated in the form of green and red fluorescence. Mitochondrial staining with Mito-Tracker Red evaluated the targeted delivery of RES into mitochondria leading to apoptosis of cancer cells.

4.
Cureus ; 16(8): e68143, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39347322

RESUMO

OBJECTIVE: This study aimed to assess the quality of primary transurethral resection of bladder tumor (TURBT) procedures performed at Aga Khan University Hospital (AKUH) over nine years, focusing on proper documentation, completeness of tumor resection, quality of histopathology reports, complication rates, and adherence to European Association of Urology (EAU) guidelines. MATERIALS AND METHODS: A retrospective analysis of patients aged 25-75 who underwent primary TURBT at AKUH between 2010 and 2019 was done. Patients with incomplete records, concomitant procedures, or those who underwent emergency TURBT were excluded. Data was collected on patient demographics, clinical presentation, intraoperative details, and histopathology reports. Statistical analysis was performed using SPSS Version 27.0. RESULTS: 300 patients were initially identified, with 265 meeting the inclusion criteria. The mean age was 61.5 years, with 83% being male. Complete tumor resection was achieved in 35% (n=92) of cases, while deep biopsy was taken in 85% (n=226). Detrusor muscle (DM), a marker of resection quality, was noted in 75% (n=200) of histopathology reports. However, documentation quality varied, with 54% (n=143) of cases lacking clear information on resection completeness. The administration of a single instillation of a chemotherapeutic agent (SICA) was recorded in 79% (n=210) of patients, and the 30-day postoperative complication rate was monitored. CONCLUSION: The study highlights areas for improvement in the quality of TURBT procedures at AKUH, particularly in the documentation of resection completeness and adherence to established guidelines. Ensuring thorough resection and proper documentation is critical to optimizing patient outcomes and future management plans.

5.
Proc Natl Acad Sci U S A ; 121(36): e2403487121, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39196626

RESUMO

Gauge theories are powerful theoretical physics tools that allow complex phenomena to be reduced to simple principles and are used in both high-energy and condensed matter physics. In the latter context, gauge theories are becoming increasingly popular for capturing the intricate spin correlations in spin liquids, exotic states of matter in which the dynamics of quantum spins never ceases, even at absolute zero temperature. We consider a spin system on a three-dimensional pyrochlore lattice where emergent gauge fields not only describe the spin liquid behavior at zero temperature but crucially determine the system's temperature evolution, with distinct gauge fields giving rise to different spin liquid phases in separate temperature regimes. Focusing first on classical spins, in an intermediate temperature regime, the system shows an unusual coexistence of emergent vector and tensor gauge fields where the former is known from classical spin ice systems while the latter has been associated with fractonic quasiparticles, a peculiar type of excitation with restricted mobility. Upon cooling, the system transitions into a low-temperature phase where an entropic selection mechanism depopulates the degrees of freedom associated with the tensor gauge field, rendering the system spin-ice-like. We further provide numerical evidence that in the corresponding quantum model, a spin liquid with coexisting vector and tensor gauge fields has a finite window of stability in the parameter space of spin interactions down to zero temperature. Finally, we discuss the relevance of our findings for non-Kramers magnetic pyrochlore materials.

6.
Nat Commun ; 15(1): 7191, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39168995

RESUMO

Quantum spin liquids (QSLs) have become a key area of research in magnetism due to their remarkable properties, such as long-range entanglement, fractional excitations, and topologically protected phenomena. Recently, the search for QSLs has expanded into the three-dimensional world, despite the suppression of quantum fluctuations due to high dimensionality. A new candidate material, K2Ni2(SO4)3, belongs to the langbeinite family and consists of two interconnected trillium lattices. Although magnetically ordered, it exhibits a highly dynamical and correlated state. In this work, we combine inelastic neutron scattering measurements with density functional theory (DFT), pseudo-fermion functional renormalization group (PFFRG), and classical Monte Carlo (cMC) calculations to study the magnetic properties of K2Ni2(SO4)3, revealing a high level of agreement between experiment and theory. We further reveal the origin of the dynamical state in K2Ni2(SO4)3 to be centred around a magnetic network composed of tetrahedra on a trillium lattice.

7.
Plants (Basel) ; 13(13)2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38999706

RESUMO

Using contaminated land to grow lignocellulosic crops can deliver biomass and, in the long term, improve soil quality. Biostimulants and microorganisms are nowadays an innovative approach to define appropriate phytomanagement strategies to promote plant growth and metal uptake. This study evaluated biostimulants and mycorrhizae application on biomass production and phytoextraction potential of four lignocellulosic crops grown under two metal-contaminated soils. Two greenhouse pot trials were setup to evaluate two annual species (sorghum, hemp) in Italy and two perennial ones (miscanthus, switchgrass) in China, under mycorrhizae (M), root (B2) and foliar (B1) biostimulants treatments, based on humic substances and protein hydrolysates, respectively, applied both alone and in combination (MB1, MB2). MB2 increased the shoot dry weight (DW) yield in hemp (1.9 times more), sorghum (3.6 times more) and miscanthus (tripled) with additional positive effects on sorghum and miscanthus Zn and Cd accumulation, respectively, but no effects on hemp metal accumulation. No treatment promoted switchgrass shoot DW, but M enhanced Cd and Cr shoot concentrations (+84%, 1.6 times more, respectively) and the phytoextraction efficiency. Root biostimulants and mycorrhizae were demonstrated to be more efficient inputs than foliar biostimulants to enhance plant development and productivity in order to design effective phytomanagement strategies in metal-contaminated soil.

8.
Endocr Pract ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38969009

RESUMO

OBJECTIVE: The objectives of this study were to evaluate the stratification of people with diabetes mellitus (DM) based on the International Diabetes Federation-Diabetes and Ramadan 2021 risk calculator into different risk categories and assess their intentions to fast and outcomes of fasting during the holy month of Ramadan. METHODS: This was a 3-month prospective study that was performed from February 9, 2023, to May 6, 2023 (6 weeks before Ramadan until 6 weeks after Ramadan), at a tertiary care hospital in Pakistan. Data regarding glycemic control, characteristics and complications of diabetes, comorbidities, and the various factors that influence fasting were gathered from patients of either sex aged 18 to 80 years with any type of diabetes. The International Diabetes Federation-Diabetes and Ramadan 2021 risk calculation and recommendation were made accordingly for each patient. RESULTS: This study comprised of 460 participants with DM, with 174 males (37.8%) and 286 females (62.2%). The risk categorization showed that 209 (45.4%), 107 (23.3%), and 144 (31.3%) of the participants were in the low-, moderate-, and high-risk categories, respectively. Of the 144 high-risk patients who fasted, 57.9% experienced hypoglycemia (P <.0001). The recommendation of fasting showed statistically significant differences with risk categories, intention to fast, hypoglycemia, type of DM, duration of DM, level of glycemic control, and days of fasting (P <.001). CONCLUSION: A statistically significant number of participants in the high-risk group who fasted experienced complications. This reiterates the importance of rigorous adherence to the medical recommendations.

9.
Rep Prog Phys ; 87(3)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38241725

RESUMO

For decades, frustrated quantum magnets have been a seed for scientific progress and innovation in condensed matter. As much as the numerical tools for low-dimensional quantum magnetism have thrived and improved in recent years due to breakthroughs inspired by quantum information and quantum computation, higher-dimensional quantum magnetism can be considered as the final frontier, where strong quantum entanglement, multiple ordering channels, and manifold ways of paramagnetism culminate. At the same time, efforts in crystal synthesis have induced a significant increase in the number of tangible frustrated magnets which are generically three-dimensional in nature, creating an urgent need for quantitative theoretical modeling. We review the pseudo-fermion (PF) and pseudo-Majorana (PM) functional renormalization group (FRG) and their specific ability to address higher-dimensional frustrated quantum magnetism. First developed more than a decade ago, the PFFRG interprets a Heisenberg model Hamiltonian in terms of Abrikosov pseudofermions, which is then treated in a diagrammatic resummation scheme formulated as a renormalization group flow ofm-particle pseudofermion vertices. The article reviews the state of the art of PFFRG and PMFRG and discusses their application to exemplary domains of frustrated magnetism, but most importantly, it makes the algorithmic and implementation details of these methods accessible to everyone. By thus lowering the entry barrier to their application, we hope that this review will contribute towards establishing PFFRG and PMFRG as the numerical methods for addressing frustrated quantum magnetism in higher spatial dimensions.

10.
Environ Sci Pollut Res Int ; 30(46): 103339-103357, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37688708

RESUMO

Nowadays, business is not only a financial entity. The environmental impact of rapid business growth necessitates solutions. This study considers natural resource orchestration theory (ROT) to study the impact of the environment management control system (MCS) package and green intellectual capital (IC) on environmental performance through the mediating role of top management support (TMS) and the interaction role of green business strategies. This study employed partial least squares structural equation modeling to analyze 358 questionnaires. Simple sampling was used to collect data from Pakistan manufacturing firms. The results revealed that the environmental MCS package significantly influences environmental performance directly and through TMS mediation. Still, the green IC does not influence environmental performance directly or through mediation in selected industries of Pakistan. Furthermore, the interaction of TMS and green business strategies significantly determines environmental performance. This study suggests managers use the environmental MCS package, green IC, top management support, and green business strategies in decision-making to determine environmental performance of manufacturing firms in Pakistan even though green IC has no influence on environmental performance. This study used natural ROT to impart the managerial role along with bundling firms' resources and strategies (i.e., environmental MCS package, green IC, top management support, and green business strategies) which is ignored in the resource-based view.

11.
Carbohydr Polym ; 321: 121318, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37739510

RESUMO

The attention to polymer-based biomaterials, for instance, chitosan and its derivatives, as well as the techniques for using them in numerous scientific domains, is continuously rising. Chitosan is a decomposable naturally occurring polymeric material that is mostly obtained from seafood waste. Because of its special ecofriendly, biocompatible, non- toxic nature as well as antimicrobial properties, chitosan-based materials have received a lot of interest in the field of biomedical applications. The reactivity of chitosan is mainly because of the amino and hydroxyl groups in its composition, which makes it further fascinating for various uses, including biosensing, textile finishing, antimicrobial wound dressing, tissue engineering, bioimaging, gene, DNA and drug delivery and as a coating material for medical implants. This study is an overview of the different types of chitosan-based materials which now a days have been fabricated by applying different techniques and modifications that include etherification, esterification, crosslinking, graft copolymerization and o-acetylation etc. for hydroxyl groups' processes and acetylation, quaternization, Schiff's base reaction, and grafting for amino groups' reactions. Furthermore, this overview summarizes the literature from recent years related to the important applications of chitosan-based materials (i.e., thin films, nanocomposites or nanoparticles, sponges and hydrogels) in different biomedical applications.


Assuntos
Quitosana , Esterificação , Materiais Biocompatíveis/farmacologia , Acetilação , Bandagens , Polímeros
12.
Future Med Chem ; 15(7): 599-613, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37140092

RESUMO

Aim: To develop an efficient and cost-effective antidiabetic agent. Methods: A simple and convenient Hantzsch synthetic strategy was used to prepare 4-adamantyl-(2-(arylidene)hydrazinyl)thiazoles. Results: Fifteen newly established structures of 4-adamantyl-(2-(arylidene)hydrazinyl)thiazoles were tested for their α-amylase, antiglycation and antioxidant activities. Almost all tested compounds showed excellent α-amylase inhibition. Compounds 3a and 3j exhibited the highest potency, with IC50 values of 16.34 ± 2.67 and 16.64 ± 1.12 µM, respectively. Compounds 3c and 3i exhibited comparable antiglycation potential with the standard, aminoguanidine. The antioxidant potential of compound 3g was found to be excellent, with an IC50 value of 28.19 ± 0.2563 µM. The binding interactions of compound 3a (binding energy = -8.833 kcal/mol) with human pancreatic α-amylase identified 3a as a potent α-amylase inhibitor. Conclusion: Enrichment of established structures with more electron-donating functionalities may assist/lead to the development of more potent antidiabetic drugs.


Diabetes is one of the major causes of death in the present era. To combat damaging processes associated with diabetes, called glycation and oxidation, we prepared a series of compounds called 4-adamantyl-(2-(arylidene)hydrazinyl)thiazoles. The established structures were tested for their antidiabetic potential. The compounds 4-adamantyl-(2-(4-chlorobenzylidene)hydrazinyl)thiazole and 4-adamantyl-(2-(2-chlorobenzylidene)hydrazinyl)thiazole showed the highest potency. The compounds 4-adamantyl-(2-(4-bromobenzylidene)hydrazinyl)thiazole and 4-adamantyl-(2-(2-hydroxybenzylidene)hydrazinyl)thiazole exhibited comparable antiglycation potential. The antioxidant potential of compound 4-adamantyl-(2-(3-nitrobenzylidene)hydrazinyl)thiazole was found to be excellent. A further test was used to check toxicity and all compounds were found to be biocompatible. We also investigated, through docking studies, the way in which these compounds interact with the human proteins albumin and pancreatic α-amylase.


Assuntos
Antioxidantes , Tiazóis , Humanos , Antioxidantes/farmacologia , Simulação de Acoplamento Molecular , Tiazóis/farmacologia , Tiazóis/química , Hipoglicemiantes/farmacologia , alfa-Amilases , Relação Estrutura-Atividade
13.
Phys Rev Lett ; 130(19): 196601, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37243662

RESUMO

Fracton phases are a particularly exotic type of quantum spin liquids where the elementary quasiparticles are intrinsically immobile. These phases may be described by unconventional gauge theories known as tensor or multipolar gauge theories, characteristic for so-called type-I or type-II fracton phases, respectively. Both variants have been associated with distinctive singular patterns in the spin structure factor, such as multifold pinch points for type-I and quadratic pinch points for type-II fracton phases. Here, we assess the impact of quantum fluctuations on these patterns by numerically investigating the spin S=1/2 quantum version of a classical spin model on the octahedral lattice featuring exact realizations of multifold and quadratic pinch points, as well as an unusual pinch line singularity. Based on large scale pseudofermion and pseudo-Majorana functional renormalization group calculations, we take the intactness of these spectroscopic signatures as a measure for the stability of the corresponding fracton phases. We find that in all three cases, quantum fluctuations significantly modify the shape of pinch points or lines by smearing them out and shifting signal away from the singularities in contrast to effects of pure thermal fluctuations. This indicates possible fragility of these phases and allows us to identify characteristic fingerprints of their remnants.

14.
Materials (Basel) ; 15(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36013795

RESUMO

The disposal of steel slag leads to the occupation of large land areas, along with many environmental consequences, due to the release of poisonous substances into the water and soil. The use of steel slag in concrete as a sand-replacement material can assist in reducing its impacts on the environment and can be an alternative source of fine aggregates. This is the very first paper that seeks to experimentally investigate the cumulative effect of steel slag and polypropylene fibers, particularly on the impact resistance of concrete. Various concrete mixes were devised by substituting natural sand with steel slag at volumetric replacement ratios of 0%, 10%, 20%, 30%, and 40%, with and without fibers. Polypropylene fibers of 12 mm length were introduced into the steel slag concrete at 0%, 0.5%, and 1.0% by weight of cement as a reinforcing material. Performance evaluation of each mix through extensive experimental testing indicated that the use of steel slag as partial substitution of natural sand, up to a certain optimum replacement level of 30%, considerably improved the compressive strength, flexural strength, and tensile strength of the concrete by 20.4%, 23.8%, and 17.0%, respectively. Furthermore, the addition of polypropylene fibers to the steel slag concrete played a beneficial role in the improvement of strength characteristics, particularly the flexural strength and final drop weight impact energy, which had a maximum rise of 48.1% and 164%, correspondingly. Moreover, integral structure and analytical analyses have also been performed in this study to validate the experimental findings. The results obtained encourage the use of fiber-reinforced steel slag concrete (FRSLC) as a potential impact-resistant material considering the environmental advantages, with the suggested substitution, of an addition ratio of 30% and 1.0% for steel slag and polypropylene fibers, respectively.

15.
Sensors (Basel) ; 22(12)2022 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-35746213

RESUMO

Globally, the surge in disease and urgency in maintaining social distancing has reawakened the use of telemedicine/telehealth. Amid the global health crisis, the world adopted the culture of online consultancy. Thus, there is a need to revamp the conventional model of the telemedicine system as per the current challenges and requirements. Security and privacy of data are main aspects to be considered in this era. Data-driven organizations also require compliance with regulatory bodies, such as HIPAA, PHI, and GDPR. These regulatory compliance bodies must ensure user data privacy by implementing necessary security measures. Patients and doctors are now connected to the cloud to access medical records, e.g., voice recordings of clinical sessions. Voice data reside in the cloud and can be compromised. While searching voice data, a patient's critical data can be leaked, exposed to cloud service providers, and spoofed by hackers. Secure, searchable encryption is a requirement for telemedicine systems for secure voice and phoneme searching. This research proposes the secure searching of phonemes from audio recordings using fully homomorphic encryption over the cloud. It utilizes IBM's homomorphic encryption library (HElib) and achieves indistinguishability. Testing and implementation were done on audio datasets of different sizes while varying the security parameters. The analysis includes a thorough security analysis along with leakage profiling. The proposed scheme achieved higher levels of security and privacy, especially when the security parameters increased. However, in use cases where higher levels of security were not desirous, one may rely on a reduction in the security parameters.


Assuntos
Privacidade , Telemedicina , Computação em Nuvem , Segurança Computacional , Confidencialidade , Humanos
16.
Food Res Int ; 157: 111205, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761527

RESUMO

Narrow leaf plantain, white clover, perennial ryegrass, and tall fescue are non-conventional edible plants having widespread existence in many temperate and Mediterranean regions worldwide. These edible plants represent valuable food resources, and genetic and genomic approaches to improving and utilising these plants for human consumption are ongoing. These plants have characteristic high antioxidant capacities attributed to their polyphenol composition. This study performed the screening of polyphenols by applying a high-throughput LC-ESI-QTOF/MS technique and determined their antioxidant potential. Seventy different polyphenols were detected with 25 compounds in narrow leaf plantain, 27 in white clover, 15 in perennial ryegrass and 14 in tall fescue. Total phenolic content (TPC) was highest in white clover (1.81 ± 0.16 mg GAE/g fresh weight (FW)), while total tannin content (TTC) was highest in perennial ryegrass (0.89 ± 0.04 mg GAE/g FW) compared with their three counterparts, respectively. Narrow leaf plantain and white clover had greater total flavonoid content (TFC) than perennial ryegrass and tall fescue. The results of this investigation provided valuable information about the unique phenolic composition and antioxidant potential of the studied non-conventional edible plants that could be used to promote their utilization in human foods, nutraceutical preparations and functional foods besides being used as a valuable source of polyphenols for different industrial sectors. Besides, the results of the study can also be used as a baseline information for the planned and targeted delivery of bioactive compounds like polyphenols to the animals by devising an appropriate feeding strategy based on the phenolic composition of these plants.


Assuntos
Plantago , Polifenóis , Animais , Antioxidantes/análise , Fenóis/análise , Folhas de Planta/química , Plantas Comestíveis , Polifenóis/análise
17.
BMC Genomics ; 23(1): 43, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012465

RESUMO

BACKGROUND: Miscanthus, which is a leading dedicated-energy grass in Europe and in parts of Asia, is expected to play a key role in the development of the future bioeconomy. However, due to its complex genetic background, it is difficult to investigate phylogenetic relationships in this genus. Here, we investigated 50 Miscanthus germplasms: 1 female parent (M. lutarioriparius), 30 candidate male parents (M. lutarioriparius, M. sinensis, and M. sacchariflorus), and 19 offspring. We used high-throughput Specific-Locus Amplified Fragment sequencing (SLAF-seq) to identify informative single nucleotide polymorphisms (SNPs) in all germplasms. RESULTS: We identified 257,889 SLAF tags, of which 87,162 were polymorphic. Each tag was 264-364 bp long. The obtained 724,773 population SNPs were used to investigate genetic relationships within three species of Miscanthus. We constructed a phylogenetic tree of the 50 germplasms using the obtained SNPs and grouped them into two clades: one clade comprised of M. sinensis alone and the other one included the offspring, M. lutarioriparius, and M. sacchariflorus. Genetic cluster analysis had revealed that M. lutarioriparius germplasm C3 was the most likely male parent of the offspring. CONCLUSIONS: As a high-throughput sequencing method, SLAF-seq can be used to identify informative SNPs in Miscanthus germplasms and to rapidly characterize genetic relationships within this genus. Our results will support the development of breeding programs with the focus on utilizing Miscanthus cultivars with elite biomass- or fiber-production potential for the developing bioeconomy.


Assuntos
Poaceae , Polimorfismo de Nucleotídeo Único , Ásia , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Poaceae/genética
18.
Phys Rev Lett ; 127(17): 177001, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34739258

RESUMO

The recent discovery of AV_{3}Sb_{5} (A=K,Rb,Cs) has uncovered an intriguing arena for exotic Fermi surface instabilities in a kagome metal. Among them, superconductivity is found in the vicinity of multiple van Hove singularities, exhibiting indications of unconventional pairing. We show that the sublattice interference mechanism is central to understanding the formation of superconductivity in a kagome metal. Starting from an appropriately chosen minimal tight-binding model with multiple van Hove singularities close to the Fermi level for AV_{3}Sb_{5}, we provide a random phase approximation analysis of superconducting instabilities. Nonlocal Coulomb repulsion, the sublattice profile of the van Hove bands, and the interaction strength turn out to be the crucial parameters to determine the preferred pairing symmetry. Implications for potentially topological surface states are discussed, along with a proposal for additional measurements to pin down the nature of superconductivity in AV_{3}Sb_{5}.

19.
Phys Rev Lett ; 127(15): 157204, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34677991

RESUMO

Quantum spin liquids are exotic states of matter that form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challenging due to the significant reduction of the influence of quantum fluctuations. Here, we report the magnetic characterization of K_{2}Ni_{2}(SO_{4})_{3} forming a three-dimensional network of Ni^{2+} spins. Using density functional theory calculations, we show that this network consists of two interconnected spin-1 trillium lattices. In the absence of a magnetic field, magnetization, specific heat, neutron scattering, and muon spin relaxation experiments demonstrate a highly correlated and dynamic state, coexisting with a peculiar, very small static component exhibiting a strongly renormalized moment. A magnetic field B≳4 T diminishes the ordered component and drives the system into a pure quantum spin liquid state. This shows that a system of interconnected S=1 trillium lattices exhibits a significantly elevated level of geometrical frustration.

20.
Int J Biol Macromol ; 191: 861-871, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34571126

RESUMO

Compressed tablet formation from granular drug require binder with Cohesiveness property. Plants mucilage as pharmaceutical excipients are available. In this study, biocompatible date palm mucilage was encapsulated with silver nano particles for sustained drug release to provoke an immune response. Nano formulated mucilage was characterized by UV/VIS, FTIR, XRD, SEM/EDX spectrophotometry. UV/VIS spectra revealed an intense surface plasmon resonance peak at 406 nm for spherical mono dispersed silver nano formulated mucilage resulted from efficient reduction of silver ions to AgNPs. Zeta sizer disclosed the emergence of single peak at 139.7 nm with 100% intensity. Crude mucilage exhibited number of peaks in the region of 4000-500 cm-1 by FT-IR spectroscopy whereas purified as well as nano formulated samples showed somewhat different pattern of peaks in addition to peaks of crude sample. XRD spectra of crude mucilage revealed somewhat regular pattern while purified and modified mucilage displayed irregular structure. In SEM analysis, crude mucilage was appeared as granular that turned into porous network with entangled tiny silver nano spheres. A controlled release of drug levofloxacin hemihydrate was evaluated using crude/ nano formulated mucilage as excipient. Nano formulated mucilage delayed the onset exposure of drug in gastric medium giving recommendations as value added bio binder for drug to the target organ.


Assuntos
Liberação Controlada de Fármacos , Nanopartículas/química , Mucilagem Vegetal/química , Antibacterianos/administração & dosagem , Células Cultivadas , Colo/metabolismo , Humanos , Levofloxacino/administração & dosagem , Phoeniceae/química
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