Cell Electrospinning: An In Vitro and In Vivo Study Sampson, Samantha L.; Saraiva, Luisa; Gustafsson, Kenth ...
Small (Weinheim an der Bergstrasse, Germany),
January 15, 2014, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Cell electrospinning and aerodynamically assisted bio‐threading are novel bioplatforms for directly forming large quantities of cell‐laden scaffolds for creating living sheets and vessels in ...three‐dimensions. The functional biological architectures generated will be useful in both the laboratory and the clinic.
Objective
Sport participation may have quality-of-life benefits for people with chronic breathlessness; however, its feasibility and impact on health are unknown. We aimed to synthesise the ...scientific literature concerning the impact of sport for people with chronic breathlessness.
Data sources
Searches of MEDLINE, CINAHL, PsycINFO, Embase, SPORTDiscus and Google Scholar were conducted (May 2023).
Review methods
Studies were included if they assessed the impact of sport with participants who were likely to suffer from chronic breathlessness due to an underlying condition (e.g. severe asthma, heart failure). A convergent-segregated approach to synthesis in accordance with the JBI methodology for mixed-methods reviews was utilised, including meta-analytic and meta-aggregation analyses.
Results
A total of 22 studies met the inclusion criteria. Studies sampled 1017 participants from 13 different countries, with sample sizes ranging from 5 to 185. Causes of breathlessness consisted of chronic respiratory diseases (9 studies) and coronary heart disease (13 studies). Design-wise, 18 reported quantitative methods, 3 qualitative, and 1 mixed-methods.
Conclusions
Sports were well-adhered to with only minor/unrelated adverse events reported. Improvements in exercise capacity were observed although there was no impact on health-related quality of life. Other quantitative outcomes extracted varied widely across studies, making it difficult to draw firm conclusions. Participation in sports was reliably recorded at intensity consistent with moderate-to-vigorous activity despite being self-paced. Qualitative themes emphasised the positive elements of sport participation, namely, social cohesion, the capacity to incorporate culture, and the idea that participation is enjoyable rather than a necessary chore to maintain one’s health.
The synthesis and physical properties of thiol–ene elastomers derived from plant-based phenolic acids were explored. Phenolic acids of varying functionality (ranging from 2 to 4 hydroxyl and carboxyl ...groups per molecule) and relative placement of functional groups (ortho, meta, para) were allylated and subsequently reacted with a multifunctional thiol using a photoinitiator. The thermal and mechanical behaviors of the resulting elastomers were characterized. The networks derived from difunctional allylated phenolic acids exhibited narrow glass transitions (indicating a high degree of network homogeneity) and glass transition temperatures (T g) which correlated with their cross-link density. The para placement of allyl groups on the allylated phenolic acid produced a network with the highest cross-link density, T g, modulus, tensile strength, and elongation at break (followed by ortho and then meta). As the functionality of the allylated monomer increased (to 3–4 allyl groups per molecule), the cross-link density remained high yet the T g decreased, attributed to a lower concentration of benzene rings throughout the network structure (as all networks were prepared at the stoichiometric ratio of allyl and thiol functional groups). The networks derived from the higher functionality allylated phenolic acids also exhibited lower elongation at break and associated tensile strength and tensile toughness, likely due to increased heterogeneity of the networks (indicated by higher glass transition widths compared to the networks derived from difunctional allylated phenolic acids). All networks exhibited behavior consistent with an ideal elastomer (affine network) at low to moderate strains, albeit with lower moduli than predicted from the monomer chemical structure. At the high end of the strain ranges achieved, some of the networks exhibited strain hardening behavior. This work develops fundamental relationships between the molecular structure of the phenolic acids, including number and placement of functional groups, and the physical properties of the resulting networks.
This work demonstrates photocatalytic CO2 reduction by a noble-metal-free photosensitizer-catalyst system in aqueous solution under red-light irradiation. A water-soluble Mn(I) tricarbonyl diimine ...complex, MnBr(4,4′-{Et2O3PCH2}2-2,2′-bipyridyl)(CO)3 (1), has been fully characterized, including single-crystal X-ray crystallography, and shown to reduce CO2 to CO following photosensitization by tetra(N-methyl-4-pyridyl)porphyrin Zn(II) tetrachloride Zn(TMPyP)Cl4 (2) under 625 nm irradiation. This is the first example of 2 employed as a photosensitizer for CO2 reduction. The incorporation of −P(O)(OEt)2 groups, decoupled from the core of the catalyst by a −CH2– spacer, afforded water solubility without compromising the electronic properties of the catalyst. The photostability of the active Mn(I) catalyst over prolonged periods of irradiation with red light was confirmed by 1H and 13C{1H} NMR spectroscopy. This first report on Mn(I) species as a homogeneous photocatalyst, working in water and under red light, illustrates further future prospects of intrinsically photounstable Mn(I) complexes as solar-driven catalysts in an aqueous environment.
Elastomeric polymer films synthesized through thiol–ene chemistry, suitable in applications as coatings and adhesives due to their ease of preparation and superior physical properties, are ...traditionally derived from petroleum sources. Of recent interest is the exploration of sustainable alternatives for the precursors to these materials. Here, we report the synthesis of thiol–ene networks through the photoinitiated reaction between allylated plant-based phenolic acids (salicylic acid and 4-hydroxybenzoic acid) and a multifunctional thiol, followed by isothermal annealing. Plant-sourced phenolic acids offer many advantages as biorenewable monomers: their rigid aromatic rings are expected to provide mechanical strength to the resulting polymers and the presence of multiple hydroxyl and carboxyl groups leads to ease of functionalization. Both phenolic acids produced networks with high degrees of homogeneity and few defects, as evidenced by narrow glass transitions and consistency of their tensile behavior with the ideal elastomer model at low-to-moderate strains. The 4-hydroxybenzoic acid based network, which had a higher cross-link density, exhibited a higher glass transition temperature, modulus, tensile strength, and elongation at break as compared to the salicylic acid based network. This work develops fundamental relationships between the molecular structure of the phenolic acids and the physical properties of the resulting networks.
Deck machinery is a leading source of hospitalized injury for commercial fishing workers in Alaska. More detailed data are needed about the specific circumstances leading to injuries for developing ...targeted prevention efforts.
This study analyzed claims submitted to the Alaska Fisherman's Fund (AFF) to identify patterns among injuries in Alaska from commercial fishing winches.
During January 1, 2000-November 1, 2020, 125 traumatic injuries from commercial fishing winches were identified, mainly occurring among males (94%), frequently among fishermen aged 30 years or younger (54%). Over 80% of winch injuries occurred in salmon fisheries. By gear type, 40% of injuries occurred on vessels using purse seine gear, 30% on vessels using drift gillnet gear, and 12% among set gillnet operators. Most injuries involved a fisherman having a body part caught in or compressed by a winch or cables attached to a winch (67%). Injuries mainly affected upper extremities including fingers (50% of cases) or hands/wrists (together 22% of cases). Injury severity was not formally assessed, but injuries ranged from contusions, sprains, and strains to finger or hand crushing injuries, upper limb amputation, skull fracture, spinal fracture, and chest trauma. Most cases involved fractures (23%), amputations (18%), lacerations (16%), and contusions (16%). Of all injuries, 51% were caused by anchor winches, 32% were caused by deck winches, 9% were caused by trailer winches, and 9% were caused by other types of winches.
Practical solutions are needed for avoiding entanglement and struck-by hazards when operating fishing winches. Anchor winches warrant focused attention, having accounted for more than half of all winch injuries identified in this study. Engineering solutions, including emergency stop devices or other simple mechanical interventions depending on winch type, could help to avert potentially disabling injuries from winches. Administrative controls such as task-specific training for winches should be emphasized, especially for younger or less experienced commercial fishing crew, who may be at increased risk for injury.
In vivo experimentation is costly and time-consuming, and presents a major bottleneck in anti-tuberculosis drug development. Conventional methods rely on the enumeration of bacterial colonies, and it ...can take up to 4 weeks for Mycobacterium tuberculosis to grow on agar plates. Light produced by recombinant bacteria expressing luciferase enzymes can be used as a marker of bacterial load, and disease progression can be easily followed non-invasively in live animals by using the appropriate imaging equipment. The objective of this work was to develop a bioluminescence-based mouse model of tuberculosis to assess antibiotic efficacy against M. tuberculosis in vivo.
We used an M. tuberculosis strain carrying a red-shifted derivative of the firefly luciferase gene (FFlucRT) to infect mice, and monitored disease progression in living animals by bioluminescence imaging before and after treatment with the frontline anti-tuberculosis drug isoniazid. The resulting images were analysed and the bioluminescence was correlated with bacterial counts.
Using bioluminescence imaging we detected as few as 1.7 × 10(3) and 7.5 × 10(4) reporter bacteria ex vivo and in vivo, respectively, in the lungs of mice. A good correlation was found between bioluminescence and bacterial load in both cases. Furthermore, a marked reduction in luminescence was observed in living mice given isoniazid treatment.
We have shown that an improved bioluminescent strain of M. tuberculosis can be visualized by non-invasive imaging in live mice during an acute, progressive infection and that this technique can be used to rapidly visualize and quantify the effect of antibiotic treatment. We believe that the model presented here will be of great benefit in early drug discovery as an easy and rapid way to identify active compounds in vivo.
Microphytobenthic communities play a significant role in nutrient modulation, sediment stabilization, and primary production in seagrass beds, which provide various ecosystem services. We ...hypothesized that microphytobenthic communities in sediments of chronically oil-exposed seagrass beds will exhibit increased resiliency to stressors associated with oil exposure as opposed to seagrass beds never exposed to oil spills. We prepared 14-liter seawater mesocosms, each containing a submersed macrophyte Ruppia maritima collected from the Chandeleur Islands, Louisiana, and Estero Bay, Florida. Mesocosms were initially exposed to 50% water-accommodated oil fractions (WAF) and subsequently diluted by 50% with daily artificial seawater exchanges over 8 days to simulate tidal dilution. High-throughput amplicon sequencing based on 23S rRNA gene targeting cyanobacteria and chloroplasts of eukaryotic microphytobenthos was conducted to assess the impact of oiling on microphytobenthic communities with additional assessment via microscopy. High-throughput sequencing in combination with traditional microscopic analysis provided a robust examination in which both methods roughly complemented each other. Distinct succession patterns were detected in benthic algal communities of chronically oil-exposed (Louisiana) versus unexposed (Florida) seagrass bed sediments. The impact of oiling in microphytobenthos across all samples showed that benthic diatoms dominated all algal communities with sample percentages ranging from 42 to 97%, followed by cyanobacteria (2 to 50%). It is noteworthy that drastic changes in microphytobenthic community structure in terms of the larger taxonomic level were not observed, rather change occurred at the phylotype level. These results were also confirmed by microscopy. Similarity percentages (SIMPER) analysis identified seven phylotypes (Cyanobacteria, Bacillariophyceae, and Mediophyceae) in the Louisiana samples and one phylotype (Bacillariophyceae) in the Florida samples that increased in relative sequence abundance after oil exposure. The detailed phylotype analysis identifying sentinel microphytobenthic indicators provides a base for future research on benthic microalgae response to ecosystem disturbance.
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•Oil did not greatly alter microphytobenthic community structure at the class level.•Chronically oil exposed sediments exhibited increased resiliency to oil stressors.•Microphytobenthic phylotypes that responded to oiling were identified.
The natural polyphenolic compound quercetin was functionalized and cross‐linked to afford a robust epoxy network. Quercetin was selectively methylated and functionalized with glycidyl ether moieties ...using a microwave‐assisted reaction on a gram scale to afford the desired monomer (Q). This quercetin‐derived monomer was treated with nadic methyl anhydride (NMA) to obtain a cross‐linked network (Q‐NMA). The thermal and mechanical properties of this naturally derived network were compared to those of a conventional diglycidyl ether bisphenol A‐derived counterpart (DGEBA‐NMA). Q‐NMA had similar thermal properties i.e., glass transition (Tg) and decomposition (Td) temperatures and comparable mechanical properties (i.e., Young's Modulus, storage modulus) to that of DGEBA‐NMA. However, it had a lower tensile strength and higher flexural modulus at elevated temperatures. The application of naturally derived, sustainable compounds for the replacement of commercially available petrochemical‐based epoxies is of great interest to reduce the environmental impact of these materials. Q‐NMA is an attractive candidate for the replacement of bisphenol A‐based epoxies in various specialty engineering applications.
A natural solution: A diglycidyl monomer prepared in two steps using a natural polyphenolic starting material, quercetin, is reacted with nadic methyl anhydride to afford epoxy cross‐linked networks. The thermal and mechanical properties of these networks are compared to similarly synthesized bisphenol A‐based epoxy materials for potential replacement in advanced engineering applications.
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