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1.
Malays J Med Sci ; 31(2): 142-152, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38694580

RESUMO

Background: Severe traumatic brain injury (TBI) is a leading cause of disability worldwide and cerebral protection (CP) management might determine the outcome of the patient. CP in severe TBI is to protect the brain from further insults, optimise cerebral metabolism and prevent secondary brain injury. This study aimed to analyse the short-term Glasgow Outcome Scale (GOS) at the intensive care unit (ICU) discharge and a month after ICU discharge of patients post CP and factors associated with the favourable outcome. Methods: This is a prospective cohort study from January 2021 to January 2022. The short-term outcomes of patients were evaluated upon ICU discharge and 1 month after ICU discharge using GOS. Favourable outcome was defined as GOS 4 and 5. Generalised Estimation Equation (GEE) was adopted to conduct bivariate GEE and subsequently multivariate GEE to evaluate the factors associated with favourable outcome at ICU discharge and 1 month after discharge. Results: A total of 92 patients with severe TBI with GOS of 8 and below admitted to ICU received CP management. Proportion of death is 17% at ICU discharge and 0% after 1 month of ICU discharge. Proportion of favourable outcome is 26.1% at ICU discharge and 61.1% after 1 month of ICU discharge. Among factors evaluated, age (odds ratio [OR] = 0.96; 95% CI: 0.94, 0.99; P = 0.004), duration of CP (OR = 0.41; 95% CI: 0.20, 0.84; P = 0.014) and hyperosmolar therapy (OR = 0.41; CI 95%: 0.21, 0.83; P = 0.013) had significant association. Conclusion: CP in younger age, longer duration of CP and patient not receiving hyperosmolar therapy are associated with favourable outcomes. We recommend further clinical trial to assess long term outcome of CP.

2.
Malays J Med Sci ; 31(1): 76-90, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38456106

RESUMO

Background: The aim of the study was to determine the predictors of meropenem treatment failure and mortality in the Intensive Care Unit (ICU). Methods: This was a retrospective study, involving sepsis and septic shock patients who were admitted to the ICU and received intravenous meropenem. Treatment failure is defined as evidence of non-resolved fever, non-reduced total white cell (TWC), non-reduced C-reactive protein (CRP), subsequent culture negative and death in ICU. Results: An Acute Physiology and Chronic Health Evaluation II (APACHE II) and duration of antibiotic treatment less than 5 days were associated with treatment failure with adjusted OR = 1.24 (95% CI: 1.15, 1.33; P < 0.001), OR = 65.43 (95% CI: 21.70, 197.23; P < 0.001). A higher risk of mortality was observed with higher APACHE and Sequential Organ Failure Assessment (SOFA) scores, initiating antibiotics > 72 h of sepsis, duration of antibiotic treatment less than 5 days and meropenem with renal adjustment dose with an adjusted OR = 1.21 (95% CI: 1.12, 1.30; P < 0.001), adjusted OR = 1.23 (95% CI: 1.08, 1.41; P < 0.001), adjusted OR = 6.38 (95% CI: 1.67, 24.50; P = 0.007), adjusted OR = 0.03 (95% CI: 0.01, 0.14; P < 0.001), adjusted OR = 0.30 (95% CI: 0.14, 0.64; P = 0.002). Conclusion: A total of 50 (14.12%) patients had a treatment failure with meropenem with 120 (48.02%) ICU mortality. The predictors of meropenem failure are higher APACHE score and shorter duration of meropenem treatment. The high APACHE, high SOFA score, initiating antibiotics more than 72 h of sepsis, shorter duration of treatment and meropenem with renal adjustment dose were predictors of mortality.

3.
Heliyon ; 9(11): e21663, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37954386

RESUMO

Gold nanoparticles (AuNPs) have emerged as a promising application in aquaculture. Their nano-sized dimensions, comparable to pathogens offer potential solutions for combating antibiotic resistance. In this study, AuNPs were synthesized by using polychaetes, Marphysa moribidii as the bio-reducing agent. Modifications were made to reduce agglomeration in green-synthesized AuNPs through ultrasonication. The antibacterial activities of AuNPs against V. parahaemolyticus were evaluated. The physicochemical characteristics of the green synthesized AuNPs were comprehensively investigated. The successful formation of AuNPs was confirmed by the appearance of a red ruby colour and the presence of surface Plasmon resonance (SPR) absorption peaks at 530 nm as observed from UV-vis spectroscopy. Scanning electron microscopy (SEM) revealed spherical-shaped AuNPs with some agglomerations. Transmission electron microscopy (TEM) showed particle size of AuNPs ranging from 10 nm to 60 nm, meanwhile dynamic light scattering (DLS) analysis indicated an average particle size of 24.36 nm. X-ray diffraction (XRD) analysis confirmed the high crystallinity of AuNPs, and no AuNPs were detected in the polychaetes extracts prior to synthesis. A brief ultrasonication significantly reduced the tendencies for AuNPs to coalesce. The green-synthesized AuNPs demonstrated a remarkable antibacterial efficacy against V. parahaemolyticus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests revealed that a concentration of 0.3 g/ml of AuNPs effectively inhibited V. parahaemolyticus. These findings highlighted the potential of green-synthesized AuNPs as antibacterial agents for the prevention and management of AHPND in aquaculture.

4.
Surg Neurol Int ; 14: 158, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37151468

RESUMO

Background: Brain cooling therapy is one of the subjects of interest, and currently, data on direct brain cooling are lacking. Hence, the objective is to investigate the clinical outcomes and discuss the thermodynamics aspect of direct brain cooling on severely injured brain patients. Methods: This pilot study recruited the severely injured brain patients who were then randomized to either a direct brain cooling therapy group using a constant cooling temperature system or a control group. All studied patients must be subjected to an emergency neurosurgical procedure of decompressive craniectomy and were monitored with intracranial pressure, brain oxygenation, and temperature. Further, comparison was made with our historical group of patients who had direct brain cooling therapy through the old technique. Results: The results disclosed the direct brain cooling treated patients through a newer technique obtained a better Extended Glasgow Outcome Score than a control group (P < 001). In addition, there is a significant outcome difference between the combined cooling treated patients (new and old technique) with the control group (P < 0.001). Focal brain oxygenation and temperature are likely factors that correlate with better outcomes. Conclusion: Direct brain cooling is feasible, safe, and affects the clinical outcomes of the severely traumatized brain, and physics of thermodynamics may play a role in its pathophysiology.

5.
Nanomaterials (Basel) ; 13(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36985957

RESUMO

At present, aerogel is one of the most interesting materials globally. The network of aerogel consists of pores with nanometer widths, which leads to a variety of functional properties and broad applications. Aerogel is categorized as inorganic, organic, carbon, and biopolymers, and can be modified by the addition of advanced materials and nanofillers. Herein, this review critically discusses the basic preparation of aerogel from the sol-gel reaction with derivation and modification of a standard method to produce various aerogels for diverse functionalities. In addition, the biocompatibility of various types of aerogels were elaborated. Then, biomedical applications of aerogel were focused on this review as a drug delivery carrier, wound healing agent, antioxidant, anti-toxicity, bone regenerative, cartilage tissue activities and in dental fields. The clinical status of aerogel in the biomedical sector is shown to be similarly far from adequate. Moreover, due to their remarkable properties, aerogels are found to be preferably used as tissue scaffolds and drug delivery systems. The advanced studies in areas including self-healing, additive manufacturing (AM) technology, toxicity, and fluorescent-based aerogel are crucially important and are further addressed.

6.
Plants (Basel) ; 12(6)2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36986948

RESUMO

Ornamental plant species introduced into new environments can exhibit an invasive potential and adaptability to abiotic stress factors. In this study, the drought stress responses of four potentially invasive ornamental grass species (Cymbopogon citratus, Cortaderia selloana, Pennisetum alopecuroides and P. setaceum) were analysed. Several seed germination parameters were determined under increasing polyethylene glycol (PEG 6000) concentrations. Additionally, plants in the vegetative stage were subjected to intermediate and severe water stress treatments for four weeks. All species registered high germination rates in control conditions (no stress treatment), even at high PEG concentrations, except C. citratus, which did not germinate at -1 MPa osmotic potential. Upon applying the water stress treatments, P. alopecuroides plants showed the highest tolerance, and C. citratus appeared the most susceptible to drought. Stress-induced changes in several biochemical markers (photosynthetic pigments, osmolytes, antioxidant compounds, root and shoot Na+ and K+ contents), highlighted different responses depending on the species and the stress treatments. Basically, drought tolerance seems to depend to a large extent on the active transport of Na+ and K+ cations to the aerial part of the plants, contributing to osmotic adjustment in all four species and, in the case of the most tolerant P. alopecuroides, on the increasing root K+ concentration under water deficit conditions. The study shows the invasive potential of all species, except C. citratus, in dry areas such as the Mediterranean region, especially in the current climate change scenario. Particular attention should be given to P. alopecuroides, which is widely commercialised in Europe as ornamental.

7.
Plants (Basel) ; 12(4)2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36840127

RESUMO

Syntenic cell wall QTLs (SQTLs) can identify genetic determinants of biomass traits in understudied species based on results from model crops. However, their effective use in plant breeding requires SQTLs to display intraspecific allelic variability and to predict causative loci in other populations/species than the ones used for SQTLs identification. In this study, genome assemblies from different accessions of Arabidopsis, rapeseed, tomato, rice, Brachypodium and maize were used to evaluate the intraspecific variability of SQTLs. In parallel, a genome-wide association study (GWAS) on cell wall quality traits was performed in miscanthus to verify the colocalization between GWAS loci and miscanthus SQTLs. Finally, an analogous approach was applied on a set of switchgrass cell wall QTLs retrieved from the literature. These analyses revealed large SQTLs intraspecific genetic variability, ranging from presence-absence gene variation to SNPs/INDELs and changes in coded proteins. Cell wall genes displaying gene dosage regulation, such as PAL and CAD, displayed presence-absence variation in Brachypodium and rapeseed, while protein INDELs were detected for the Brachypodium homologs of the rice brittle culm-like 8 locus, which may likely impact cell wall quality. Furthermore, SQTLs significantly colocalized with the miscanthus and switchgrass QTLs, with relevant cell wall genes being retained in colocalizing regions. Overall, SQTLs are useful tools to screen germplasm for relevant genes and alleles to improve biomass quality and can increase the efficiency of plant breeding in understudied biomass crops.

8.
Mol Ecol ; 32(5): 1000-1019, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36511846

RESUMO

The blue shark Prionace glauca is a top predator with one of the widest geographical distributions of any shark species. It is classified as Critically Endangered in the Mediterranean Sea, and Near Threatened globally. Previous genetic studies did not reject the null hypothesis of a single global population. The blue shark was proposed as a possible archetype of the "grey zone of population differentiation," coined to designate cases where population structure may be too recent or too faint to be detected using a limited set of markers. Here, blue shark samples collected throughout its global range were sequenced using a specific RAD method (DArTseq), which recovered 37,655 genome-wide single nucleotide polymorphisms (SNPs). Two main groups emerged, with Mediterranean Sea and northern Atlantic samples (Northern population) differentiated significantly from the Indo-west Pacific samples (Southern population). Significant pairwise FST values indicated further genetic differentiation within the Atlantic Ocean, and between the Atlantic Ocean and the Mediterranean Sea. Reconstruction of recent demographic history suggested divergence between Northern and Southern populations occurred about 500 generations ago and revealed a drastic reduction in effective population size from a large ancestral population. Our results illustrate the power of genome scans to detect population structure and reconstruct demographic history in highly migratory marine species. Given that the management plans of the blue shark (targeted or bycatch) fisheries currently assume panmictic regional stocks, we strongly recommend that the results presented here be considered in future stock assessments and conservation strategies.


Assuntos
Polimorfismo de Nucleotídeo Único , Tubarões , Animais , Polimorfismo de Nucleotídeo Único/genética , Tubarões/genética , Densidade Demográfica , Deriva Genética , Oceano Atlântico
9.
Environ Sci Pollut Res Int ; 30(13): 37105-37117, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36567391

RESUMO

Being a prominent tourist destination, the hotel industry's demand in Malaysia has been increasing day by day. There is still a shortage of studies focusing on how hotels can make environmental management routine work, take environmental laws seriously and be more responsive to the environment. This study focused on the connections between green employee involvement, green performance management and green dynamic capability in implementing environmental law in the hospitality industry. The study also evaluates the mediating role of implementing environmental law between green employee involvement, green performance management, green dynamic capability and organisational citizenship behaviour to reduce pollution. This study employed a quantitative approach to test the hypotheses and a convenient sampling method to collect the data from hotel employees. Out of 600 distributed questionnaires, useable responses were 253 to proceed with data analysis. Data were analysed through structural equation modelling (SEM) using the Smart-PLS and SPSS. The relationship between green employee involvement, green performance management, green dynamic capability and implementation of environmental laws was discovered and considered unique in the hotel industry in Malaysia. The study further established the mediating role of environmental law between independent and dependent variables.


Assuntos
Cidadania , Indústrias , Humanos , Poluição Ambiental , Inquéritos e Questionários , Malásia
10.
Glob Change Biol Bioenergy ; 15(4): 444-461, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38505760

RESUMO

New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low-cost rapid light interception measurements using a simple laboratory-made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass. We apply the model to project the European biomass potentials of new market-ready hybrids for 2020-2030. Field measurements are easier to collect, the calibration is seasonally dynamic and reduces influence of weather variation between field sites. The model obtained is conservative, being calibrated by crops of varying establishment and varying maturity on less productive (marginal) land. This results in conservative projections of miscanthus hybrids for 2020-2030 based on 10% land use conversion of the least (productive) grassland and arable for farm diversification, which show a European potential of 80.7-89.7 Mt year-1 biomass, with potential for 1.2-1.3 EJ year-1 energy and 36.3-40.3 Mt year-1 carbon capture, with seeded Miscanthus sacchariflorus × sinensis displaying highest yield potential. Simulated biomass projections must be viewed in light of the field measurements on less productive land with high soil water deficits. We are attempting to model the results from an ambitious and novel project combining new hybrids across Europe with agronomy which has not been perfected on less productive sites. Nevertheless, at the time of energy sourcing issues, seed-propagated miscanthus hybrids for the upscaled provision of bioenergy offer an alternative source of renewable energy. If European countries provide incentives for growers to invest, seeded hybrids can improve product availability and biomass yields over the current commercial miscanthus variety.

11.
Polymers (Basel) ; 14(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36365671

RESUMO

The current work discusses ground coffee waste (GCW) reinforced high-density polyethylene (HDPE) composite. GCW underwent two types of treatment (oil extraction, and oil extraction followed by mercerization). The composites were prepared using stacking HDPE film and GCW, followed by hot compression molding with different GCW particle loadings (5%, 10%, 15% and 20%). Particle loadings of 5% and 10% of the treated GCW composites exhibited the optimum level for this particular type of composite, whereby their mechanical and thermal properties were improved compared to untreated GCW composite (UGC). SEM fracture analysis showed better adhesion between HDPE and treated GCW. The FTIR conducted proved the removal of unwanted impurities and reduction in water absorption after the treatment. Specific tensile modulus improved for OGC at 5 vol% particle loading. The highest impact energy absorbed was obtained by OGC with a 16% increment. This lightweight and environmentally friendly composite has potential in high-end packaging, internal automotive parts, lightweight furniture, and other composite engineering applications.

12.
Biomater Res ; 26(1): 55, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36217173

RESUMO

BACKGROUND: To support bone regeneration, 3D-printed templates function as temporary guides. The preferred materials are synthetic polymers, due to their ease of processing and biological inertness. Poly(lactide-co-trimethylene carbonate) (PLATMC) has good biological compatibility and currently used in soft tissue regeneration. The aim of this study was to evaluate the osteoconductivity of 3D-printed PLATMC templates for bone tissue engineering, in comparison with the widely used 3D-printed polycaprolactone (PCL) templates. METHODS: The printability and physical properties of 3D-printed templates were assessed, including wettability, tensile properties and the degradation profile. Human bone marrow-derived mesenchymal stem cells (hBMSCs) were used to evaluate osteoconductivity and extracellular matrix secretion in vitro. In addition, 3D-printed templates were implanted in subcutaneous and calvarial bone defect models in rabbits. RESULTS: Compared to PCL, PLATMC exhibited greater wettability, strength, degradation, and promoted osteogenic differentiation of hBMSCs, with superior osteoconductivity. However, the higher ALP activity disclosed by PCL group at 7 and 21 days did not dictate better osteoconductivity. This was confirmed in vivo in the calvarial defect model, where PCL disclosed distant osteogenesis, while PLATMC disclosed greater areas of new bone and obvious contact osteogenesis on surface. CONCLUSIONS: This study shows for the first time the contact osteogenesis formed on a degradable synthetic co-polymer. 3D-printed PLATMC templates disclosed unique contact osteogenesis and significant higher amount of new bone regeneration, thus could be used to advantage in bone tissue engineering.

13.
Surg Neurol Int ; 13: 370, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36128129

RESUMO

Background: Elizabethkingia meningoseptica meningitis is rare and challenging to manage infection. As this infection is always associated with superimposed multidrug-resistant organisms, a combination and prolonged antibiotic treatment are necessary to ensure the complete eradication of infections. Case Description: We report successful antibiotic therapies in a patient with E. meningoseptica bacteremia and meningitis complicated with superimposed extreme-drug-resistant Acinetobacter baumannii infection in a patient post transsphenoidal hypophysectomy complicated with central venous thrombosis. Conclusion: Antibiotic combination therapy with prolonged duration in those with E. meningoseptica with concomitant multi-resistant organisms is needed. Diagnosing associated prothrombotic risk with the infection and prompt treatment would also be essential.

14.
Malays J Med Sci ; 29(4): 131-139, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36101537

RESUMO

Background: A dedicated trauma operation theatre (TOT) and a trauma intensive care unit (TICU) within the same block as the emergency department (ED) can facilitate immediate management and surgery of patients suffering from traumatic brain injury (TBI). The present study compared the effectiveness and outcomes of TBI management between the TOT-TICU and general OT (GOT) and neuro-ICU (NICU) setups. Methods: This was a retrospective cohort study involving 120 patients with TBI who were divided into the GOT-NICU (n = 63) and TOT-TICU (n = 57) groups. Data were obtained from patients' admission and medical records. Demographic data, durations of specific management phases and outcomes of patients were documented. Results: In the TOT-TICU group, the duration of transportation from ED to OT [15 (standard deviation [SD] = 15) min versus 45 (SD = 15) min; P < 0.001], duration of arrival in OT to incision [50 (SD = 30) versus 70 (SD = 23) min; P = 0.005] and duration of transportation from OT to ICU [40 (SD = 17) versus 48 (SD = 30); P = 0.005] were significantly shorter than those in the GOT-NICU group. However, the duration of mechanical ventilation, duration of ICU stays, Glasgow Outcome Scale (GOS) upon discharge and GOS at 3-month post-discharge were comparable between both groups. Conclusion: The TOT-TICU setup shortened the duration of transportation from ED to OT, duration of arrival in OT to incision and duration of transportation from OT to ICU compared with the GOT-NICU setup. Hence, the availability of OT and ICU within the trauma block managed to provide immediate management to TBI patients.

15.
Polymers (Basel) ; 14(12)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746044

RESUMO

Natural and synthetic fibres are in high demand due to their superior properties. Natural fibres are less expensive and lighter as compared to synthetic fibres. Synthetic fibres have drawn much attention, especially for their outstanding properties, such as durability, and stability. The hybridisation between natural and synthetic fibres composite are considered as an alternative to improve the current properties of natural and synthetic fibres. Therefore, this study aimed to determine the physical and mechanical properties of pineapple leaf fibre (PALF) and Kevlar reinforced unsaturated polyester (UP) hybrid composites. The PALF/Kevlar hybrid composites were fabricated by using hand layup method utilising unsaturated polyester as the matrix. These composites were laid up to various laminated configurations, such as [PKP]s, [PPK]s, [KPP]s, [KKP]s, [PPP]s and [KKK]s, whereby PALF denoted as P and Kevlar denoted as K. Next, they were cut into size and dimensions according to standards. Initially, the density of PALF/Kevlar reinforced unsaturated polyester were evaluated. The highest density result was obtained from [KKK]s, however, the density of hybrid composites was closely indistinguishable. Next, moisture absorption behaviour and its effects on the PALF/Kevlar reinforced unsaturated polyester were investigated. The water absorption studies showed that the hybridisation between all PALF and Kevlar specimens absorbed moisture drastically at the beginning of the moisture absorption test and the percentage of moisture uptake increased with the volume fraction of PALF in the samples. The tensile test indicated that all specimens exhibited nonlinear stress-strain behaviour and shown a pseudo-ductility behaviour. [KKP]s and [KPK]s hybrid composites showed the highest tensile strength and modulus. The flexural test showed that [KPK]s had the highest flexural strength of 164.0 MPa and [KKP]s had the highest flexural modulus of 12.6 GPa. In terms of the impact strength and resistance, [KKP]s outperformed the composite laminates. According to SEM scans, the hybrid composites demonstrated a stronger interfacial adhesion between the fibres and matrix than pure PALF composite.

16.
Aquat Toxicol ; 248: 106208, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35635983

RESUMO

In marine organisms, differing degree of sensitivity to ocean acidification (OA) is expected for each life stage, and disturbance at one stage can carry over into the following stage or following generation. In this study we investigated phenotypic changes of sperm and larvae of the sea urchin Paracentrotus lividus in response to different pH conditions (8.0, 7.7, 7.4) experienced by the parents during gametogenesis. In sperm from two-months exposed males, sperm motility, velocity, ATP content, ATP consumption and respiration rate were evaluated at three pH values of the activating medium (8.0, 7.7 and 7.4). Moreover, larvae from each parental group were reared at pH 8.0 and 7.7 for 20 days and larval mortality and growth were then assessed. Sperm motility and respiration rate were not affected either by exposure of males to low pH or by the post-activation pH. Sperm velocity did not differ among post-activation pH values in all sperm groups, but it decreased slower in sperm developed under acidified conditions, suggesting the presence of positive carryover effect on sperm longevity. This positive carryover effect of exposure of males to low pH values was highlighted also for the sperm ATP content, which was higher in these groups of sperm. ATP consumption rate was affected by post-activation pH with higher values at pH 8.0 in sperm from males maintained at control condition and pH 7.7 while the energy consumption appeared to be differently modulated at different experimental conditions. A negative carry over effect of OA was observed on survival of larvae from parents acclimated at pH 7.4 and additive negative effects of both parental and larval exposure to low pH can be suggested. In all groups of larvae, decreased somatic growth was observed at low rearing pH, thus larvae from parents maintained at low pH did not show an increased capability to cope with OA.


Assuntos
Paracentrotus , Poluentes Químicos da Água , Adaptação Fisiológica , Trifosfato de Adenosina , Animais , Concentração de Íons de Hidrogênio , Larva , Masculino , Oceanos e Mares , Ouriços-do-Mar , Água do Mar/química , Motilidade dos Espermatozoides , Espermatozoides , Poluentes Químicos da Água/toxicidade
17.
Polymers (Basel) ; 14(7)2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35406196

RESUMO

Natural and synthetic fibres have emerged in high demand due to their excellent properties. Natural fibres have good mechanical properties and are less expensive, making them a viable substitute for synthetic fibers. Owing to certain drawbacks such as their inconsistent quality and hydrophilic nature, researchers focused on incorporating these two fibres as an alternative to improve the limitations of the single fibre. This review focused on the interply hybridisation of natural and synthetic fibres into composites. Natural fibres and their classifications are discussed. The physical and mechanical properties of these hybrid composites have also been included. A full discussion of the mechanical properties of natural/synthetic fibre hybrid composites such as tensile, flexural, impact, and perforation resistance, as well as their failure modes, is highlighted. Furthermore, the applications and future directions of hybrid composites have been described in details.

18.
Polymers (Basel) ; 14(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35406261

RESUMO

Natural-fiber-reinforced composites, especially bamboo, are an alternative material to compete with conventional materials. Their environmentally friendly, renewable, low-cost, low-density, non-toxic, and fully biodegradable properties are concerning for researchers because of their advantages over synthetic polymers. This comprehensive review presents the results of work on bamboo fiber composites with special reference to bamboo types, thermoplastic and thermoset polymers matrices, hybrid composites, and their applications. In addition, several studies prove that these properties are very good and efficient in various applications. However, in the development of composite technology, bamboo fiber has certain constraints, especially in moisture conditions. Moisture is one of the factors that reduces the potential of bamboo fiber and makes it a critical issue in the manufacturing industry. Therefore, various efforts have been made to ensure that these properties are not affected by moisture by treating the surface fibers using chemical treatments.

19.
Int J Biol Macromol ; 206: 954-976, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35304199

RESUMO

The emergence of nanocellulose from various natural resources as a promising nanomaterial has been gaining interest for a wide range application. Nanocellulose serves as an excellent candidate since it contributes numerous superior properties and functionalities. In this review, details of the three main nanocellulose categorised: cellulose nanocrystal (CNC), cellulose nanofibril (CNF), and bacterial nanocellulose (BNC) have been described. We focused on the preparation and isolation techniques to produce nanocellulose including alkaline pre-treatment, acid hydrolysis, TEMPO-mediated oxidation, and enzymatic hydrolysis. The surface modification of nanocellulose through esterification, silylation, amidation, phosphorylation, and carboxymethylation to improve the diverse applications has also been reviewed. Some invigorating perspectives on the applications, challenges, and future directions on the relevant issues regarding nanocellulose are also presented.


Assuntos
Nanopartículas , Nanoestruturas , Celulose/química , Hidrólise , Nanoestruturas/química
20.
J Hum Genet ; 67(7): 381-386, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35046476

RESUMO

Primary ciliary dyskinesia (PCD) is a clinically and genetically heterogeneous ciliopathy. Dysfunction of motile respiratory and nodal cilia results in sinopulmonary symptoms associated with laterality defects (LD) found in half of the patients. The molecular basis of the disease is insufficiently investigated in patients originating from the Arabian Peninsula. In a group of 16 unrelated Saudi patients clinically suspected of PCD and among whom only 5 (31%) had LD, we first screened by PCR-RFLP two founder mutations, RSPH9 c.804_806del and CCDC39 c.2190del previously identified in patients from the Arabian Peninsula and Tunisia, respectively. When negative, targeted panel or whole-exome sequencing was performed. Three patients were homozygous for the mutation in RSPH9, which encodes an axonemal protein that is absent from nodal cilia. None of the patients carried the CCDC39 founder mutation frequent in Tunisia. NGS analysis showed that nine patients had homozygous mutations in PCD genes. In total, sequential RFLP and NGS analysis solved 75% (12/16) of cases and identified ten distinct mutations, among which six are novel, in nine different genes. These results, which highlight the genetic heterogeneity of PCD in Saudi Arabia, show that the RSPH9 c.804_806del mutation is a prevalent mutation among Saudi patients, whereas the CCDC39 c.2190del ancestral allele is most likely related to the Berber population. This study shows that RSPH9 founder mutation first-line screening and NGS analysis is efficient for the genetic exploration of PCD in Saudi patients. The RSPH9 founder mutation accounts for the low rate of LD among Saudi patients.


Assuntos
Proteínas do Citoesqueleto , Síndrome de Kartagener , Proteínas do Citoesqueleto/genética , Efeito Fundador , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Síndrome de Kartagener/diagnóstico , Síndrome de Kartagener/genética , Mutação , Arábia Saudita
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