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1.
Small ; : e2404373, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39011730

RESUMO

Short peptide-based supramolecular hydrogels hold enormous potential for a wide range of applications. However, the gelation of these systems is very challenging to control. Minor changes in the peptide sequence can significantly influence the self-assembly mechanism and thereby the gelation propensity. The involvement of SARS CoV E protein in the assembly and release of the virus suggests that it may have inherent self-assembling properties that can contribute to the development of hydrogels. Here, three pentapeptide sequences derived from C-terminal of SARS CoV E protein are explored with same amino acid residues but different sequence distributions and discovered a drastic difference in the gelation propensity. By combining spectroscopic and microscopic techniques, the relationship between peptide sequence arrangement and molecular assembly structure are demonstrated, and how these influence the mechanical properties of the hydrogel. The present study expands the variety of secondary structures for generating supramolecular hydrogels by introducing the 310-helix as the primary building block for gelation, facilitated by a water-mediated structural transition into ß-sheet conformation. Moreover, these Fmoc-modified pentapeptide hydrogels/supramolecular assemblies with tunable morphology and mechanical properties are suitable for tissue engineering, injectable delivery, and 3D bio-printing applications.

2.
Environ Res ; 259: 119575, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38986799

RESUMO

NH2-functionalized metal-organic frameworks (NH2-functionalized MOFs) can abate organic pollutants, predominantly favored by their chemical, mechanical, and thermal stabilities. The present review stated the chemistry of identifying NH2-functionalization and its role in enhancing the properties of bare MOFs. The integration of the amine group bestows several advantages: 1.) enabling band structure modification, 2.) establishing strong metal-NH2 bonds, 3.) preserving MOF structures from reactive oxygen species, and 4.) shielding MOF structures against pH alterations. Consequently, the NH2-functionalized MOFs are promising materials for the photodegradation of organic contaminants. The following section illustrates the two approaches (pre-synthetic and post-synthetic) for NH2-functionalized MOFs. Nevertheless, specific intrinsic limitations, entailing a high recombination rate of charge carriers and inadequate optical adsorption, restrain the applicability of NH2-functionalized MOFs. Accordingly, the succeeding segment presents strategies to elevate the photocatalytic activities of NH2-functionalized MOFs via heterojunction fabrication. The importance of the NH2-functionalized MOFs-based heterojunction has been evaluated in terms of the effect on the enhancement of charge separation, optical adsorption, and redox ability of charge carriers. Subsequently, the potential application for organic pollutant degradation via NH2-functionalized MOFs-based heterojunctions has been scrutinized, wherein the organic pollutants. Eventually, the review concluded with challenges and potential opportunities in engaging and burgeoning domains of the NH2-functionalized MOFs-based heterojunctions.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Catálise , Recuperação e Remediação Ambiental/métodos , Poluentes Ambientais/química , Fotólise , Processos Fotoquímicos
3.
Eur J Oral Sci ; 132(5): e13016, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39272220

RESUMO

The study aimed to investigate the influence of H2O2-based and H2O2-free in-office bleaching on the surface and mechanical attributes of CAD/CAM composite blocks. CAD/CAM composite blocks from five different composite materials (CC1, CC2, CC3, CC4, and CC5) were randomly divided into two groups according to bleaching application (H2O2-based and H2O2-free). The surface topography, morphology, nanohardness, elastic modulus, flexural strength, and fracture toughness were measured. A paired and unpaired sample t-tests gauged the effect of pre- and post-bleaching on the substrates. The estimated mean differences (before-after bleaching) suggested an increase in surface roughness for two materials CC2 and CC4, and a significant decrease in nanohardness for material CC4 and in elastic modulus for materials CC2 and CC4 with H2O2-based bleaching, whereas H2O2-free bleaching resulted in changes compatible with no change in these properties. Flexural strength and fracture toughness showed no evidence of changes, irrespective of the bleaching gel used. Scanning electron microscopic analysis revealed erosive effects and micropore formation due to H2O2-based bleaching. H2O2-based bleaching deteriorates the surface of CAD/CAM composite materials while H2O2-free bleaching gel had an insignificant effect on both surface and bulk properties. The clinician should carefully evaluate the potential effects of H2O2-based bleaching on the surface properties of CAD/CAM composites.


Assuntos
Resinas Compostas , Desenho Assistido por Computador , Módulo de Elasticidade , Resistência à Flexão , Peróxido de Hidrogênio , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Clareadores Dentários , Clareamento Dental , Resinas Compostas/química , Peróxido de Hidrogênio/química , Clareadores Dentários/química , Materiais Dentários/química , Humanos , Dureza , Peróxidos/química , Restauração Dentária Permanente , Estética Dentária
4.
Anal Chem ; 95(36): 13638-13648, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37651212

RESUMO

Aggregation-induced emission (AIE)-based fluorescent organic nanoparticles (FONPs) with distinctive characteristics are emerging as superior sensors due to their facile fabrication, high signal-to-noise ratio, and good biocompatibility. The present article delineates the detection and analysis of the redox behavior of the protein disulfide isomerase (PDI) enzyme by exploitation of the AIE of novel naphthalimide (NI) derivatives having thiol (-SH) and disulfide (-S-S-) moieties. Self-aggregated spherical-shaped organic nanoparticles were prepared by synthesized NI-based amphiphiles (NISH, NISS, NINSS, and TNINSH) through J-type aggregation in DMSO-water (fw = 99 vol %). Naphthyl residue containing NI-derived amphiphiles (NINSS and TNINSH) exhibited AIE (blue and yellow) at 470 and 550 nm, respectively, in DMSO-water (fw = 99 vol %). NINSS and TNINSH FONPs were suitably utilized in sensing PDI through their redox nature of thiol-disulfide exchange. Fluorescence quenching of NINSS FONPs was observed due to reduction of disulfide to thiol by PDI, whereas emission intensity was progressively red-shifted and enhanced ("Dual-AIE") for TNINSH (containing ER-targeting N-tosylethylenediamine), owing to oxidation of thiol to disulfide by PDI. NINSS and TNINSH FONPs were found to be highly efficient in sensing PDI through the AIE-based "fluorescence off/on" mechanism having limits of detection of ∼12.6-17.7 and ∼11.7-16.5 ng/mL, respectively. In vitro cell imaging for NIH3T3 (noncancer) and B16F10 (melanoma) cells with NINSS and TNINSH FONPs displayed excellent diagnosis of eukaryotic cells upon interaction with indigenous PDI. Notably, detection of cancer cells was more sensitive over the noncancerous cells by these FONPs due to overexpression of PDI within cancer cells.


Assuntos
Dimetil Sulfóxido , Isomerases de Dissulfetos de Proteínas , Camundongos , Animais , Células NIH 3T3 , Naftalimidas , Corantes , Dissulfetos , Oxirredução , Compostos de Sulfidrila , Água
5.
Chembiochem ; 24(18): e202300253, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37232377

RESUMO

The present work depicts the development of stable nanogels in an aqueous medium that were exploited for efficient surface-active lipase-catalyzed hydrolysis of water-insoluble substrates. Surfactant-coated gel nanoparticles (neutral NG1, anionic NG2, and cationic NG3) were prepared from peptide amphiphilic hydrogelator (G1, G2, and G3, respectively) at different hydrophilic and lipophilic balance (HLB). Chromobacterium viscosum (CV) lipase activity towards hydrolysis of water-insoluble substrates (p-nitrophyenyl-n-alkanoates (C4-C10)) in the presence of nanogels got remarkably improved by ~1.7-8.0 fold in comparison to that in aqueous buffer and other self-aggregates. An increase in hydrophobicity of the substrate led to a notable improvement in lipase activity in the hydrophilic domain (HLB>8.0) of nanogels. The micro-heterogeneous interface of small-sized (10-65 nm) nanogel was found to be an appropriate scaffold for immobilizing surface-active lipase to exhibit superior catalytic efficiency. Concurrently, the flexible conformation of lipase immobilized in nanogels was reflected in its secondary structure having the highest α-helix content from the circular dichroism spectra.


Assuntos
Lipase , Água , Hidrólise , Nanogéis , Água/química , Lipase/química , Catálise
6.
Environ Res ; 222: 115349, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36709022

RESUMO

Architecting a desirable and highly efficient nanocomposite for applications like adsorption, catalysis, etc. has always been a challenge. Metal Organic Framework (MOF)-based hierarchical composite has perceived popularity as an advanced adsorbent and catalyst. Hierarchically structured MOF material can be modulated to allow the surface interaction (external or internal) of MOF with the molecules of interest. They are well endowed with tunable functionality, high porosity, and increased surface area epitomizing mass transfer and mechanical stability of the fabricated nanostructure. Additionally, the anticipated optimization of nanocomposite can only be acquired by a thorough understanding of the synthesis techniques. This review starts with a brief introduction to MOF and the requirement for advanced nanocomposites after the setback faced by conventional MOF structures. Further, we discussed the background of MOF-based hierarchical composites followed by synthetic techniques including chemical and thermal treatment. It is important to rationally validate the successful nanocomposite fabrication by characterization techniques, an overview of challenges, and future perspectives associated with MOF-based hierarchically structured nanocomposite.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Purificação da Água , Nanocompostos/química , Catálise , Adsorção
7.
Environ Res ; 238(Pt 2): 117288, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37797665

RESUMO

Hydrogen production, catalytic organic synthesis, carbon dioxide reduction, environmental purification, and other major fields have all adopted photocatalytic technologies due to their eco-friendliness, ease of use, and reliance on sunlight as the driving force. Photocatalyst is the key component of photocatalytic technology. Thus, it is of utmost importance to produce highly efficient, stable, visible-light-responsive photocatalysts. CIS stands out among other visible-light-response photocatalysts for its advantageous combination of easy synthesis, non-toxicity, high stability, and suitable band structure. In this study, we took a brief glance at the synthesis techniques for CIS after providing a quick introduction to the fundamental semiconductor features, including the crystal and band structures of CIS. Then, we discussed the ways doping, heterojunction creation, p-n heterojunction, type-II heterojunction, and Z-scheme may be used to modify CIS's performance. Subsequently, the applications of CIS towards pollutant degradation, CO2 reduction, water splitting, and other toxic pollutants remediation are reviewed in detail. Finally, several remaining problems with CIS-based photocatalysts are highlighted, along with future potential for constructing more superior photocatalysts.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Catálise , Luz , Tecnologia
8.
Sensors (Basel) ; 23(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37765797

RESUMO

The rapid advancements in technology have paved the way for innovative solutions in the healthcare domain, aiming to improve scalability and security while enhancing patient care. This abstract introduces a cutting-edge approach, leveraging blockchain technology and hybrid deep learning techniques to revolutionize healthcare systems. Blockchain technology provides a decentralized and transparent framework, enabling secure data storage, sharing, and access control. By integrating blockchain into healthcare systems, data integrity, privacy, and interoperability can be ensured while eliminating the reliance on centralized authorities. In conjunction with blockchain, hybrid deep learning techniques offer powerful capabilities for data analysis and decision making in healthcare. Combining the strengths of deep learning algorithms with traditional machine learning approaches, hybrid deep learning enables accurate and efficient processing of complex healthcare data, including medical records, images, and sensor data. This research proposes a permissions-based blockchain framework for scalable and secure healthcare systems, integrating hybrid deep learning models. The framework ensures that only authorized entities can access and modify sensitive health information, preserving patient privacy while facilitating seamless data sharing and collaboration among healthcare providers. Additionally, the hybrid deep learning models enable real-time analysis of large-scale healthcare data, facilitating timely diagnosis, treatment recommendations, and disease prediction. The integration of blockchain and hybrid deep learning presents numerous benefits, including enhanced scalability, improved security, interoperability, and informed decision making in healthcare systems. However, challenges such as computational complexity, regulatory compliance, and ethical considerations need to be addressed for successful implementation. By harnessing the potential of blockchain and hybrid deep learning, healthcare systems can overcome traditional limitations, promoting efficient and secure data management, personalized patient care, and advancements in medical research. The proposed framework lays the foundation for a future healthcare ecosystem that prioritizes scalability, security, and improved patient outcomes.


Assuntos
Blockchain , Aprendizado Profundo , Humanos , Segurança Computacional , Ecossistema , Atenção à Saúde , Registros Eletrônicos de Saúde
9.
Pak J Med Sci ; 39(1): 223-226, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36694769

RESUMO

Objective: This study aimed to improve the mechanical properties of denture base material using various concentrations of natural biopolymer, i.e., Gum Arabic (GA). Methods: This experimental study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from May 2022 to July 2022. After obtaining exemption from the institutional review board, the powdered GA was added in ratios of weight 5, 10, and 20% to PMMA heat-cured acrylic powder to produce bar-shaped samples (65 × 10 × 30 mm3 in dimensions). While the control group was prepared as such. Micro hardness (n=10/group) and fracture toughness (n=10/group) were evaluated. One-way analysis of variance method was used to statistically analyze the results (p<0.05) using SPSS version 23. Results: Significant differences were observed for micro hardness (p<0.001) and fracture toughness (p=0.007) between the means of the different study groups. The control group exhibited the highest micro hardness (22.5±0.6 VHN) and fracture toughness (1.25±0.11 MPa.m1/2) value among the study groups. While 20 wt. % GA and 10 wt. % GA groups showed the lowest micro hardness and fracture toughness values, respectively. Conclusions: GA powder might not be an appropriate reinforcing material for denture base or the higher filler loading of GA in denture base acrylic might be detrimental to the mechanical properties.

10.
Pak J Med Sci ; 39(6): 1631-1636, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37936770

RESUMO

Objective: This laboratory study determined the surface, mechanical and chemical properties of polymethyl methacrylate (PMMA) denture resin reinforced with micron-sized Gum Arabic (GA) powder in different weight ratios. Methods: This laboratory study was conducted at the Dental Health Department of the College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia from November 2022 to February 2023. Three experimental denture resins were prepared by incorporating GA powder in heat-polymerized PMMA powder using different wt.% (5, 10, and 20 wt.%). While pristine PMMA served as the control group. A total of ten bar-shaped specimens with dimensions of 65 mm × 10 mm × 3.5 mm were prepared for each study group. The surface properties (micro CT and SEM evaluation), mechanical properties (Nanohardness, elastic modulus and flexural strength) and chemical properties (FTIR) were conducted. The data were statistically analyzed using the one-way analysis of variance and Tukey's post hoc tests (p<0.05). Results: The surface and bulk properties of experimental GA-reinforced PMMA resin materials deteriorated while the mechanical properties were also negatively altered using GA-based PMMA denture resin. A linear correlation was observed between weak mechanical properties and increasing wt.% of GA in denture resin. Conclusions: The incorporation of GA powder in denture resin might not be a viable option. The surface and mechanical properties of experimental PMMA composites were adversely affected compared to the control group.

11.
Environ Res ; 207: 112650, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34979124

RESUMO

Very recently the green synthesis routes of nanomaterials have attracted massive attention as it overcome the sustainability concerns of conventional synthesis approaches. With this heed, in this novel research work we have synthesized the g-C3N4 nanosheets based nanocomposites by utilizing Eriobotrya japonica as mediator and stabilizer agent. Our designed bio-caped and green g-C3N4 nanosheets based nanocomposites have abundant organic functional groups, activated surface and strong adsorption capability which are very favorable for conversion CO2 into useful products and bisphenol A degradation. Beneficial to further upgrade the performances of g-C3N4 nanosheets, the resulting pristine g-C3N4 nanosheets are coupled with LaFeO3 nanosheets via SrO bridge. Based on our experimental results such as TEM, XRD, DRS, TPD, TGA, PL, PEC and FS spectra linked with OH amount it is confirmed that the biologically mediated green g-C3N4 nanosheets are eco-friendly, highly efficient and stable. Furthermore, the coupling of LaFeO3 nanosheets enlarged the surface area, enhanced the charge separation, while the insertion of SrO bridge worked as facilitator for electron transportation and photo-electron modulation. In contrast to pristine green g-C3N4 nanosheets (GCN), the activities of final resulting sample 6LFOS-(4SrO)-GCN are improved by 8.0 times for CO2 conversion (CH4 = 4.2, CO = 9.2 µmol g-1 h-1) and 2.5-fold for bisphenol A degradation (88%) respectively. More specifically, our current research work will open a new gateway to design cost effective, eco-friendly and biological inspired green nanomaterials for CO2 conversion and organic pollutants degradation which will further support the net zero carbon emission manifesto and the optimization of carbon neutrality level.


Assuntos
Dióxido de Carbono , Nanocompostos , Compostos Benzidrílicos , Catálise , Fenóis
12.
Photodermatol Photoimmunol Photomed ; 38(6): 591-599, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35811336

RESUMO

PURPOSE: To evaluate the bacterial, clinical, and cytokine profile of adjunctive photodynamic therapy using chloro-aluminum phthalocyanine (CAP/aPDT) with root surface debridement (RSD) versus RSD alone in cigarette smokers (CS) and never-smokers (NS) during the period of 6 months. METHODS: Twenty-nine patients [CS - 14 and NS - 15] were recruited for the trial having stage-III periodontitis. All candidates from the study groups were subjected to a split-mouth treatment technique receiving CAP/aPDT + RSD and RSD alone. Periodontal parameters including plaque levels (PL), bleeding on probing (BP), probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. Polymerase chain reaction (qPCR) assay was used to analyze the copy numbers of Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf). Levels of tumor necrosis factor-alpha (TNF-α) interleukin (IL)-6 in the crevicular fluid were evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: CAP/aPDT+RSD decreased BP in smokers after 6 months (p < .05). Probing depth and CAL reported statistically significant reductions within both CAP/aPDT+RSD and RSD groups and also within the NS and CS (p < .05). Pg and Tf stayed elevated in smokers at the 6-month evaluation period (p < .01). Only CAP/aPDT+RSD significantly decreased Pg and Tf at 3- and 6-month follow-up in smokers (p < .05). CAP/aPDT+RSD showed decreased IL-6 levels in the NS during the 6-month follow-up (p < .01). TNF-α levels were significantly reduced in the CS group with CAP/aPDT+RSD and RSD alone until 6 months (p < .01). CONCLUSION: CAP-mediated aPDT along with nonsurgical periodontal therapy helped to improve the bacteriological outcomes among smokers and never-smokers with stage-III CP patients.


Assuntos
Anti-Infecciosos , Periodontite Crônica , Fotoquimioterapia , Humanos , Periodontite Crônica/tratamento farmacológico , Interleucina-6 , Índice Periodontal , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Aplainamento Radicular/métodos , Fumar , Fator de Necrose Tumoral alfa
13.
Photodermatol Photoimmunol Photomed ; 38(6): 582-590, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35678189

RESUMO

PURPOSE: To assess the clinical periodontal, bacterial, and immunological outcomes of chloro-aluminum phthalocyanine-mediated photodynamic therapy (PDT) as an adjunct to dental scaling (DS) versus DS alone among cigarette smokers (CS) and never-smokers (NS). METHODS: A total of 26 patients (13 CS and 13 NS) with clinical and radiographic diagnosis of stage-II chronic periodontitis were recruited. Each patient from both groups were subjected with two parallel therapies (split-mouth): PDT + DS (test side) and DS alone (control side). Periodontal parameters were investigated by evaluating plaque scores (PS), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and alveolar bone loss (ABL). Subgingival plaque was collected to detect and quantify Porphyromonas gingivalis and Tannerella forsythia using real-time quantitative polymerase chain reaction (RT-qPCR) assay. Gingival crevicular fluid was sampled for the quantification of interleukin (IL)-1ß and tumor necrosis factor-alpha (TNF-α) using enzyme linked immunosorbent assay. All assessments were performed at baseline, 3 months, and 6 months. RESULTS: Bleeding on probing was significantly reduced at 6 months after PDT + DS in CS groups (p < .05). Mean PD and CAL significantly reduced after both PDT + DS and DS subgroups and among NS and CS groups (p < .05). At 6 months follow-up, the copy number of both P. gingivalis and T. forsythia remained significantly high in CS group (p < .01). Only PDT + DS subgroup in CS significantly reduced the counts of P. gingivalis and T. forsythia at 3 months and 6 months (p < .05). Only at 6 months did PDT + DS showed statistically significantly reduced IL-1ß levels in the NS group (p < .01). TNF-α levels significantly reduced in CS group with PDT + DS and DS alone at both 3 months and 6 months follow-up (p < .01). CONCLUSION: Chloro-aluminum phthalocyanine-mediated PDT helped to improve the non-surgical periodontal therapy outcomes among stage-II chronic periodontitis patients among smokers and never-smokers.


Assuntos
Periodontite Crônica , Fotoquimioterapia , Humanos , Periodontite Crônica/tratamento farmacológico , Aplainamento Radicular , Bolsa Periodontal/tratamento farmacológico , Bolsa Periodontal/microbiologia , Fumantes , Fator de Necrose Tumoral alfa
14.
Natl Med J India ; 35(2): 74-77, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36461850

RESUMO

Background The prevalence of tobacco use is high in rural India, but limited information on tobacco use among the tribal population is available. We assessed the prevalence of tobacco use and type of tobacco use in the Gond tribal population. Methods We did a cross-sectional survey among the Gond tribal population residing in the Kundam block of Jabalpur district in Madhya Pradesh state in India. The study was carried out among persons aged 6 years and above during February-May 2017. Pre-tested interview schedules were used by trained field investigators to collect information on tobacco use. Results A total of 3351 individuals were included in this study, of which 58% were using some form of tobacco. The prevalence of tobacco use was higher among men compared to women, and it increased significantly from age 6 to 25 in both men and women. Tobacco use was significantly associated with age, gender and educational status of the respondents. Conclusion The study highlights a high tobacco use in the Gond tribe population. The high prevalence of tobacco use in younger ages is a matter of serious concern. The study establishes a need for information, education and communication and behavioural change communication activities; health camps focusing on the harmful effects of tobacco use and tobacco control campaign among tribal communities, tribal schools and ashrams.


Assuntos
Comunicação , Uso de Tabaco , Masculino , Feminino , Humanos , Estudos Transversais , Uso de Tabaco/epidemiologia , Escolaridade , Índia/epidemiologia
15.
Sensors (Basel) ; 22(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36146168

RESUMO

The effects of mutual coupling on the scanning characteristics of a four-element linear rectangular dielectric resonator antenna array (RDRA) are investigated for different inter-element spacing in this work. In particular, the gain and half-power beam width (HPBW) of an RDRA are studied for various scan angles in the E- and H-plane configurations. It is shown that for both the E and H planes, mutual coupling has an adverse effect on the performance of both phased array configurations. The H-plane array, however, is more stable than the E-plane array in terms of a gain and beam width performance comparison. The HPBW increases and gain decreases more in the E plane than the H plane when the scan angle is increased.

16.
Int J Mol Sci ; 23(10)2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35628546

RESUMO

Amidst growing technological advancements, newer denture base materials and polymerization methods have been introduced. During fabrication, certain mechanical properties are vital for the clinical longevity of the denture base. This systematic review aimed to explore the effect of newer denture base materials and/or polymerization methods on the mechanical properties of the denture base. An electronic database search of English peer-reviewed published papers was conducted using related keywords from 1 January 2011, up until 31 December 2021. This systematic review was based on guidelines proposed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search identified 579 papers. However, the inclusion criteria recognized 22 papers for eligibility. The risk of bias was moderate in all studies except in two where it was observed as low. Heat cure polymethyl methacrylate (PMMA) and compression moulding using a water bath is still a widely used base material and polymerization technique, respectively. However, chemically modified PMMA using monomers, oligomers, copolymers and cross-linking agents may have a promising result. Although chemically modified PMMA resin might enhance the mechanical properties of denture base material, no clear inferences can be drawn about the superiority of any polymerization method other than the conventional compression moulding technique.


Assuntos
Bases de Dentadura , Polimetil Metacrilato , Teste de Materiais , Polimerização , Polímeros , Polimetil Metacrilato/química
17.
J Environ Manage ; 310: 114757, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35220093

RESUMO

Understanding public preferences and evaluating the river basin are essential for effective river basin management, and enhancing its environmental attributes can provide considerable non-market benefits. As such, the study explores the heterogeneity in people's preferences and rankings of river ecosystem services based on their willingness to pay (WTP) to upgrade these services. A research survey was conducted throughout the river basin using a choice experiment approach. In this study, we evaluated the impact of study area elevation (a spatial attribute) on residents' willingness to pay for rehabilitation of environmental attributes. The study incorporates 6 ecological attributes in order to examine the differences in people's willingness to pay at various elevation levels. A total of five cities and 33 surrounding villages and townships were surveyed, while five elevation groups were made on an ad hoc basis to split samples, i.e., 1000-1600 m, ≤1600-2200 m, ≤2200-2800 m, > 2800-3400 m, and 3400-4000 m. The results of the mixed logit model recognized that people living at different elevations value rehabilitation of varying environmental attributes differently. For example, the inhabitants in Group 1 (1000-1600 mm) are willing to pay RMB 6.70 per year for biodiversity upgrades; while the WTP of the people for the same attributes is RMB 32.68 in Group 5 (3400-4000 mm). The Krinsky Robb approach confirmed that agricultural product quality and greenhouse gases (GHGs) were the most highly valued attributes, with a willingness to pay of RMB 90.40 and RMB 47.17, respectively. Applying these results as a reference for sustainable improvements and uplift of deteriorated ecological qualities is an example of how they may be helpful in bettering the world.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Cidades , Conservação dos Recursos Naturais/métodos , Humanos , Políticas , Opinião Pública , Rios
18.
J Pak Med Assoc ; 72(11): 2218-2222, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37013290

RESUMO

OBJECTIVE: To identify the dietary patterns and understand their association with sociodemographic characteristics among adults. METHODS: The community-based cross-sectional study was conducted in Islamabad, Lahore, Karachi, Peshawar and Quetta cities of Pakistan from March to November 2018, after approval from the National Bioethics Committee, Islamabad, and comprised adults of either gender. Data was collected using the food frequency questionnaire, and dietary patterns were identified using factor analysis. Multivariate regression analysis was used to assess the association of socio-demographic determinants with dietary patterns. Data was analysed using SPSS 21. Parallel Analysis criterion (Eigen values) was determined along with Monte Carlo simulation. RESULTS: Of the 448 subjects, 206(46%) were males and 242(54%) were females. The largest age group was 36-55 years 199(47.4%). Six dietary patterns were identified: "Vegetables", "Fruits", "Mixed Junk and Processed food", "Dairy and Fast food", "Discretionary" and "Fish". Regression analysis showed that those aged 36-55 years had higher scores for vegetables, fruit and fish pattern (p<0.05). Females scored more for vegetables, fish and fruits, and a significantly low score for discretionary diet pattern (p<0.05). Participants with high education level and socioeconomic status had raised scores for discretionary diet items (p<0.05). CONCLUSIONS: Six distinct dietary patterns among Pakistani adults were identified, showing significant association with sociodemographic characteristics.


Assuntos
Dieta , Frutas , Animais , Paquistão , Estudos Transversais , Verduras , Comportamento Alimentar
19.
Environ Res ; 202: 111716, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34293311

RESUMO

Commercial membranes typically suffer from fouling and wetting during membrane distillation (MD). In contrast, reverse osmosis (RO) can be subject to the fouling issue if applied for highly saline feed solutions containing foulants (e.g., organics, oils, and surfactants). Among the diverse treatment options, the nanomaterial-based membranes have recently gained great interest due to their advantageous properties (e.g., enhanced flux and roughness, better pore size distribution, and higher conductivity). This review focuses on recent advances in the mechanical properties, anti-fouling capabilities, salt rejection, and economic viability of metal oxide (SiO2, TiO2, and ZnO) and carbon nanomaterial (graphene oxide/carbon nanotube)-based membranes. Current challenges in applying nanomaterial-based membranes are also discussed. The study further describes the preparation methods, mechanisms, commercial applications, and economical feasibility of metal oxide- and carbon nanomaterial-based membrane technologies.


Assuntos
Nanoestruturas , Purificação da Água , Destilação , Membranas Artificiais , Osmose , Dióxido de Silício
20.
Surgeon ; 19(1): 27-32, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32199773

RESUMO

INTRODUCTION: Faecal Immunohistochemistry Testing (FIT) is recommended as an adjunct to guide referrals from Primary Care for individuals without rectal bleeding, who do not meet the suspected cancer pathway referral guidelines. It has largely replaced Faecal Occult Blood Testing. AIMS: To assess the specificity of FIT. To understand the characteristics of FIT negative cancer patients and whether they have predominantly right sided cancers. Evaluating the efficacy of FIT and Iron deficiency anaemia in combination to capture patients with colorectal cancers. METHODS: A study of 1000 symptomatic patients, undergoing FIT by Clinicians during the 'Digital rectal examination'. Inclusion criteria; all patients referred via our cancer referral pathway. FIT positivity was set at 10 µg g of faeces. RESULTS: There were 7 FIT negative cancers in this cohort; 1 was a lymphoma and the other 6 were caecal adenocarcinomas. 5 were anaemic. The positive predictive value of IDA was 34% compared with 'other symptoms'; 18%. The negative predictive value of FIT was 99.05% in this cohort. Specificity for FIT was 86.9% (CI 96%). CONCLUSION: Two separate referral pathways for IDA and FIT positive tests, would have captured all patients except 2; the lymphoma and 1 advanced caecal adenocarcinoma. FIT is an excellent triage tool prior to colonoscopy however capturing right sided disease remains a weak point. Multivariate analysis of patients in addition to IDA and FIT should improve capture of this subgroup.


Assuntos
Anemia Ferropriva , Neoplasias Colorretais , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/etiologia , Colonoscopia , Neoplasias Colorretais/complicações , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer , Humanos , Imuno-Histoquímica , Programas de Rastreamento , Sangue Oculto
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