142 research outputs found
Spatial distribution of early red lesions is a risk factor for development of vision-threatening diabetic retinopathy
Aims/hypothesis
Diabetic retinopathy is characterised by morphological lesions related to disturbances in retinal blood flow. It has previously been shown that the early development of retinal lesions temporal to the fovea may predict the development of treatment-requiring diabetic maculopathy. The aim of this study was to map accurately the area where lesions could predict progression to vision-threatening retinopathy.
Methods
The predictive value of the location of the earliest red lesions representing haemorrhages and/or microaneurysms was studied by comparing their occurrence in a group of individuals later developing vision-threatening diabetic retinopathy with that in a group matched with respect to diabetes type, age, sex and age of onset of diabetes mellitus who did not develop vision-threatening diabetic retinopathy during a similar observation period.
Results
The probability of progression to vision-threatening diabetic retinopathy was higher in a circular area temporal to the fovea, and the occurrence of the first lesions in this area was predictive of the development of vision-threatening diabetic retinopathy. The calculated peak value showed that the risk of progression was 39.5% higher than the average. There was no significant difference in the early distribution of lesions in participants later developing diabetic maculopathy or proliferative diabetic retinopathy.
Conclusions/interpretation
The location of early red lesions in diabetic retinopathy is predictive of whether or not individuals will later develop vision-threatening diabetic retinopathy. This evidence should be incorporated into risk models used to recommend control intervals in screening programmes for diabetic retinopathy
Diabetic retinopathy: current and future methods for early screening from a retinal hemodynamic and geometric approach
Diabetic retinopathy (DR) is a major disease and is the number one cause of blindness in the UK. In England alone, 4200 new cases appear every year and 1280 lead to blindness. DR is a result of diabetes mellitus, which affects the retina of the eye and specifically the vessel structure. Elevated levels of glucose cause a malfunction in the cell structure, which affects the vessel wall and, in severe conditions, leads to their breakage. Much research has been carried out on detecting the different stages of DR but not enough versatile research has been carried out on the detection of early DR before the appearance of any lesions. In this review, the authors approach the topic from the functional side of the human eye and how hemodynamic factors that are impaired by diabetes affect the vascular structur
Biocrude from hydrothermal liquefaction of indigenous municipal solid waste for green energy generation and contribution towards circular economy: A case study of urban Pakistan.
In this study, biocrude was successfully produced by the hydrothermal liquefaction of municipal solid waste collected from the landfill site of Lahore, the capital of Punjab, Pakistan, boasting a population of 12 million and an annual waste collection of 10 million tons. The hydrothermal liquefaction process was performed at reaction parameters of 350 °C and 165 bars with 15 min of residence time. The solid waste was found to have 78 % dry matter, 22 % moisture contents, 22.2 % ash, 22.69 MJ/kg higher heating value, 52.062 % C, 8.007 % H, 0.764 % N, and 39.164 % O. Non-catalytic process only produced 10.57 % oil, however when using the catalytic process, the biocrude yield improved to 17.61 %, with 22.61 % energy recovery for biocrude and 12.14 % for solids, when using 2 g dose of K2CO3. The resultant biocrude has a 28.61 MJ/kg higher heating value, having 60.28 % C and 9.28 % H. In contrast, the aqueous phase generated had 4.43 pH, 71.5 g/L TOC, and 1.35 g/L Total Nitrogen. TGA indicated that biocrude contains approximately 80 % of volatile fractions of different fuels. The organic compounds having the six highest peak areas in GC-MS were Ethyl ether 25.74 %, 2-pentanone, 4-hydroxy-4-methyl 9.08 %, 2-propanone, 1,1-dimethoxy 5.62 %, Silane, dimethyl (docosyloxy) butoxy 5.08 %, 1-Hexanol, 2-ethyl 4.53 %, and. Phenol 4.07 %. This work makes the first-ever successful use of indigenous solid waste from a landfill dumping site in Lahore to successfully produce useful biocrude with aims of waste reduction and management, circular economy, and energy recovery
Frictional stability of pumice-reinforced lightweight magnesium composite in ambient and elevated temperature environments
Lightweight materials with better resistance to sliding wear are prominent candidates for automobile brake drums, clutch pads and cylinder block applications to facilitate fuel economy. This attempt is reserved to cater to materials with higher tribological quality needs. Less dense foamy pumice stone particles were involved in three different percentages (5, 10, and 15 wt%) to reinforce lightweight AZ31 Mg alloy. A stir-assisted squeeze casting technique was pursued to process the composite and refine the grain structure. A phase detection, elemental mapping and microstructure study were done through X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), respectively. An experimental dry sliding wear scrutiny was administered using a pin-on-disc apparatus by considering: (i) ambient and elevated temperature environments and (ii) three different levels of loads. The results reveal a significant drop in wear loss and a frictional coefficient for 15% pumice-loaded composite than the base alloy. Post-wear examination acknowledges the fact that the ambient temperature wear is governed by adhesive-abrasive wear and high temperature is by abrasive wear mechanisms. Worn-out scrutiny authenticates the presence of oxide layers and their role in lubrication. A comparative study with previous works upholds the novel magnesium composite is the right candidate for the mentioned automobile applications
The evolutionary signal in metagenome phyletic profiles predicts many gene functions
Background. The function of many genes is still not known even in model organisms. An increasing availability of microbiome DNA sequencing data provides an opportunity to infer gene function in a systematic manner. Results. We evaluated if the evolutionary signal contained in metagenome phyletic profiles (MPP) is predictive of a broad array of gene functions. The MPPs are an encoding of environmental DNA sequencing data that consists of relative abundances of gene families across metagenomes. We find that such MPPs can accurately predict 826 Gene Ontology functional categories, while drawing on human gut microbiomes, ocean metagenomes, and DNA sequences from various other engineered and natural environments. Overall, in this task, the MPPs are highly accurate, and moreover they provide coverage for a set of Gene Ontology terms largely complementary to standard phylogenetic profiles, derived from fully sequenced genomes. We also find that metagenomes approximated from taxon relative abundance obtained via 16S rRNA gene sequencing may provide surprisingly useful predictive models. Crucially, the MPPs derived from different types of environments can infer distinct, non-overlapping sets of gene functions and therefore complement each other. Consistently, simulations on > 5000 metagenomes indicate that the amount of data is not in itself critical for maximizing predictive accuracy, while the diversity of sampled environments appears to be the critical factor for obtaining robust models. Conclusions. In past work, metagenomics has provided invaluable insight into ecology of various habitats, into diversity of microbial life and also into human health and disease mechanisms. We propose that environmental DNA sequencing additionally constitutes a useful tool to predict biological roles of genes, yielding inferences out of reach for existing comparative genomics approaches
Full-length human Surfactant Protein A inhibits Influenza A Virus infection of A549 lung epithelial cells: a recombinant form containing neck and lectin domains promotes infectivity
Hydrophilic lung surfactant proteins have emerged as key immunomodulators aimed at recognition and clearance of pulmonary pathogens. Surfactant protein A (SP-A) is a surfactant-associated innate immune pattern recognition molecule, which is known to interact with a variety of pathogens, and display anti-microbial effects. SP-A, being carbohydrate pattern recognition molecule, has been suggested to have a wide range of innate immune functions against pathogens. In addition, SP-A can work against respiratory pathogens, including influenza A virus (IAV). Some pandemic pH1N1 strains resist neutralization by SP-A due to differences in the N-glycosylation of viral hemagglutinin (HA). Here, we provide evidence, for the first time, that a recombinant form of human SP-A (rfhSP-A) composed of α-helical neck and carbohydrate recognition domains can actually promote the IAV replication, as observed by an upregulation of M1 expression in lung epithelial cell line, A549, when challenged with pH1N1 and H3N2 IAV subtypes. rfhSP-A (10 μg/ml) bound neuraminidase (NA) (˜60 kDa), matrix protein 1 (M1) (˜25 kDa) and M2 (˜17 kDa) in a calcium dependent manner, as revealed by far western blotting, and direct binding ELISA. However, human full length native SP-A downregulated mRNA expression levels of M1 in A549 cells challenged with IAV subtypes. Furthermore, qPCR analysis showed that transcriptional levels of TNF-α, IL-12, IL-6, IFN-α and RANTES were enhanced following rfhSP-A treatment by both IAV subtypes at 6 h post-IAV infection of A549 lung epithelial cells. In the case of full length SP-A treatment, mRNA expression levels of TNF-α, and IL-6 were downregulated during the mid-to-late stage of IAV infection of A549 cells. Multiplex cytokine/chemokine array revealed enhanced levels of both IL-6 and TNF-α due to rfhSP-A treatment in the case of both IAV subtypes tested, while no significant effect was seen in the case of IL-12. Enhancement of IAV infection of pH1N1 and H3N2 subtypes by truncated rfhSP-A, concomitant with infection inhibition by full-length SP-A, appears to suggest that a complete SP-A molecule is required for protection against IAV. This is in contrast to a recombinant form of trimeric lectin domains of human SP-D (rfhSP-D) that acts as an entry inhibitor of IAV.KACST (14-MED258-20
State of the Art: Natural fibre-reinforced composites in advanced development and their physical/chemical/mechanical properties
Nowadays, people are highly conscious of the environment, leading to rapid growth and progress in research and innovation in eco-friendly natural fiber composites (NFCs), which are also cost-effective. The sustainable development of biodegradable NFCs obtained from renewable sources is paving the way for the replacement of synthetic fiber composites. Furthermore, researchers are focusing on enhancing the mechanical performance of NFCs for various applications. Some renewable sources, such as rice, wheat, and corn, have been used to produce polylactic acid-based NFCs. Due to their low greenhouse gas emissions and minimal energy consumption during production, NFCs are also suitable for 3D printing applications. However, they do have some drawbacks, and to overcome them, they are often blended with other NFCs. The purpose of this review article is to provide data on the physical, chemical, and mechanical properties of natural fiber-reinforced composites to assist new researchers. The central idea is that natural, biodegradable, and eco-friendly materials can replace plastics, enhancing their properties in terms of mechanical strength, thermal resistance, antimicrobial properties, water absorption, and degradability. The use of NFCs is flourishing in various fields. Every year, a substantial amount of agricultural waste with potential fibers is discarded. Some examples of waste products include fruit, including areca and tamarind. The reinforcement obtained from these materials is utilized in polymer composites for lightweight structures, the automotive industry, and domestic applications
Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases
Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics
RSM and Artificial Neural Networking based production optimization of sustainable Cotton bio-lubricant and evaluation of its lubricity & tribological properties
Depletion of mineral reservoirs along with health and environmental concerns have led to a greater focus on bio-lubricants. The purpose of this study was to analyze and optimize the reaction conditions of the transesterification process for cotton biolubricant synthesis by using Response Surface Methodology (RSM). In RSM, Rotatable central composite design was selected to examine the effect of reaction input factors on the yield of cotton bio-lubricant during the transesterification process. ANOVA analysis showed that temperature was the most significant factor followed by time, pressure and catalyst-concentration. Optimum reaction conditions obtained by RSM for maximum TMP tri-ester (cotton bio-lubricant) yield of about 37.52% were 144 °C temperature, 10 h time, 25 mbar pressure, and 0.8% catalyst-concentration. RSM predicted results were successfully validated experimentally and by artificial neural networking. About 90%–94% cotton seed oil bio-lubricant was obtained after purification and its physiochemical, lubricity and tribological properties were evaluated and found comparable with ISO VG-46 and SAE-40 mineral lubricant. Hence, cottonseed oil is a potential source for the bio-lubricant industry
- …
