146 research outputs found
Recommended from our members
An Investigation of Thin Feature Generation in Direct Metal Laser Sintering Systems
The fabrication of metal structures with thin features (<1mm) with additive manufacturing processes is
of interest for various lightweight applications. This paper investigates the geometrical and
microstructural characteristics of thin features fabricated using an EOS direct metal laser sintering
(DMLS) system. Both 1D and 2D thin features were fabricated using various process themes, and
subsequently analyzed for microstructure geometrical characteristics. It was found that the selection of
process parameters has significant influence on both the geometrical accuracy and the microstructure of
the thin features. The results can be used for the further development of process guidelines for
lightweight structures such as cellular structures and support structures.Mechanical Engineerin
Anthropophilic Behavior of Aedes albopictus: A Predominant Vector of Dengue/Chikungunya in Thiruvananthapuram district, Kerala, South India
Human host seeking behavior of Aedes albopictus was evaluated using human landing collections conducted during both dry and wet seasons of 2010-2012 in Thiruvanathapuram district, Kerala. Collections were segregated hourly to provide a time distribution of host-seeking behavior. Aedes albopictusā day time landing collections comprised of 36.89% and maintained 3-4 per man hour (PMH) density during morning hours whereas 2-3 per man hour density during afternoon hours. PMH density of Aedes albopictus (P < 0.001) and Aedes vittatus (P < 0.05) varied significantly between pre and post monsoon seasons. PMH density of Aedes albopictus is correlated with humidity at pre monsoon season (r = 0.64) but slightly correlated with post monsoon season (r = 0.35). Night time collections showed the presence of Ae. albopictus and Ae. vittatus from both indoor and outdoor landing collections. Density of both Ae. albopictus and Ae. vittatus significantly varied in Day time and Indoor (Night time) collections (P < 0.05). Density of Aedes albopictus significantly varied in Day time and Thinnai (Night time) collections (P < 0.05). Aedes albopictus was the only species that varied both in Indoor and Thinnai night time collections (P < 0.05). This study revealed that the Ae. albopictus mosquitoes predominantly bite during day time (95.5%) compared to night time in Thinnai (3.9%). Increase in dengue cases reported during the post monsoon period in Kerala was due to the increased human host seeking behavior (71.3%) of Ae. albopictus
Receptor-Binding and Oncogenic Properties of Polyoma Viruses Isolated from Feral Mice
Laboratory strains of the mouse polyoma virus differ markedly in their abilities to replicate and induce tumors in newborn mice. Major determinants of pathogenicity lie in the sialic binding pocket of the major capsid protein Vp1 and dictate receptor-binding properties of the virus. Substitutions at two sites in Vp1 define three prototype strains, which vary greatly in pathogenicity. These strains replicate in a limited fashion and induce few or no tumors, cause a disseminated infection leading to the development of multiple solid tumors, or replicate and spread acutely causing early death. This investigation was undertaken to determine the Vp1 type(s) of new virus isolates from naturally infected mice. Compared with laboratory strains, truly wild-type viruses are constrained with respect to their selectivity and avidity of binding to cell receptors. Fifteen of 15 new isolates carried the Vp1 type identical to that of highly tumorigenic laboratory strains. Upon injection into newborn laboratory mice, the new isolates induced a broad spectrum of tumors, including ones of epithelial as well as mesenchymal origin. Though invariant in their Vp1 coding sequences, these isolates showed considerable variation in their regulatory sequences. The common Vp1 type has two essential features: 1) failure to recognize āpseudoreceptorsā with branched chain sialic acids binding to which would attenuate virus spread, and 2) maintenance of a hydrophobic contact with true receptors bearing a single sialic acid, which retards virus spread and avoids acute and potentially lethal infection of the host. Conservation of these receptor-binding properties under natural selection preserves the oncogenic potential of the virus. These findings emphasize the importance of immune protection of neonates under conditions of natural transmission
Recommended from our members
Receptor-Binding and Oncogenic Properties of Polyoma Viruses Isolated from Feral Mice
Laboratory strains of the mouse polyoma virus differ markedly in their abilities to replicate and induce tumors in newborn mice. Major determinants of pathogenicity lie in the sialic binding pocket of the major capsid protein Vp1 and dictate receptor-binding properties of the virus. Substitutions at two sites in Vp1 define three prototype strains, which vary greatly in pathogenicity. These strains replicate in a limited fashion and induce few or no tumors, cause a disseminated infection leading to the development of multiple solid tumors, or replicate and spread acutely causing early death. This investigation was undertaken to determine the Vp1 type(s) of new virus isolates from naturally infected mice. Compared with laboratory strains, truly wild-type viruses are constrained with respect to their selectivity and avidity of binding to cell receptors. Fifteen of 15 new isolates carried the Vp1 type identical to that of highly tumorigenic laboratory strains. Upon injection into newborn laboratory mice, the new isolates induced a broad spectrum of tumors, including ones of epithelial as well as mesenchymal origin. Though invariant in their Vp1 coding sequences, these isolates showed considerable variation in their regulatory sequences. The common Vp1 type has two essential features: 1) failure to recognize āpseudoreceptorsā with branched chain sialic acids binding to which would attenuate virus spread, and 2) maintenance of a hydrophobic contact with true receptors bearing a single sialic acid, which retards virus spread and avoids acute and potentially lethal infection of the host. Conservation of these receptor-binding properties under natural selection preserves the oncogenic potential of the virus. These findings emphasize the importance of immune protection of neonates under conditions of natural transmission
Cost-effectiveness of cenobamate for focal seizures in people with drug-resistant epilepsy
OBJECTIVES: To estimate the cost-effectiveness of add-on cenobamate in the UK when used to treat drug-resistant focal seizures in adults who are not adequately controlled with at least two prior antiseizure medication, including at least one used adjunctively. METHODS: We estimated the cost per quality-adjusted life-year (QALY) for cenobamate compared to brivaracetam, eslicarbazepine, lacosamide and perampanel in the UK National Health Service over a lifetime time horizon. We used a Markov cohort structure to determine response to treatment, using pooled data from three long-term studies of cenobamate. A network meta-analysis informed the likelihood of response to therapy with brivaracetam, eslicarbazepine, lacosamide and perampanel relative to cenobamate. Once individuals discontinued treatment, they transitioned to subsequent treatment health states, including other antiseizure medicines, surgery, and vagus nerve stimulation. Costs included treatment, administration, routine monitoring, event management and adverse events. Published evidence and expert opinion informed the likelihood of response to subsequent treatments, associated adverse events, and costs. Utility data was based on short-form, six dimensions utility. Discounting was applied at 3.5% per annum as per National Institute for Health and Care Excellence guidance. Uncertainty was explored through deterministic and probabilistic sensitivity analyses. RESULTS: In the base case, cenobamate led to cost savings of Ā£51,967 (compared to brivaracetam), Ā£21,080 (compared to eslicarbazepine), Ā£33,619 (compared to lacosamide), and Ā£28,296 (compared to perampanel) and increased QALYs of 1.047 (compared to brivaracetam), 0.598 (compared to eslicarbazepine), 0.776 (compared to lacosamide), and 0.703 (compared to perampanel) per individual over a lifetime time horizon. Cenobamate also dominated the four drugs across most sensitivity analyses. Differences were due to reduced seizure frequency with cenobamate relative to comparators. SIGNIFICANCE: Cenobamate improved QALYs and was less costly than brivaracetam, eslicarbazepine, lacosamide and perampanel. Therefore, cenobamate may be considered as a cost-effective adjunctive antiseizure medication for people with drug-resistant focal seizures
Ciprofloxacin-Resistant Neisseria meningitidis, Delhi, India
Decreased susceptibility of Neisseria meningitidis isolates to ciprofloxacin emerged from an outbreak in Delhi, India. Results of antimicrobial susceptibility testing of the meningococcal isolates to ciprofloxacin and further sequencing of DNA gyrase A quinolone-resistanceādetermining region confirmed the emergence of ciprofloxacin resistance in the outbreak
Autologous blood products : Leucocyte and Platelets Rich Fibrin (L-PRF) and Platelets Rich Plasma (PRP) gel to promote cutaneous ulcer healing ā a systematic review
Objective To summarise evidence on the effectiveness of Platelet-Rich Plasma (PRP) gel and Leucocyte and Platelet Rich Fibrin (L-PRF) gel as agents promoting ulcer healing compared with the standard wound dressing techniques alone.
Design Systematic review.
Eligibility criteria Individual patient randomised controlled trials on skin ulcers of all types excluding traumatic lesions.
Intervention group: treatment with topical application of L-PRF gel or PRP gel to the wound surface.
Control group: treatment with standard skin ulcer care using normal saline, normgel or hydrogel dressings.
Information sources Medline (Ovid), Excerpta Medica Database (EMBASE), Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Web of Science and manual search of studies from previous systematic reviews and meta-analyses. The papers published from 1946 to 2022 with no restriction on geography and language were included. The last date of the search was performed on 29 August 2022.
Data extraction and synthesis Independent reviewers identified eligible studies, extracted data, assessed risk of bias using V.2 of the Cochrane risk-of-bias tool for randomised trials tool and assessed certainty of evidence by using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
Main outcome measures Time to complete healing, proportion healed at a given time and rate of healing.
Results Seven studies met the inclusion criteria, five using PRP gel and two using L-PRF gel. One study showed a better proportion of complete healing, three reported reduced meantime to complete healing and five showed improved rate of healing per unit of time in the intervention group. The risk of bias was high across all studies with one exception and the GRADE showed very low certainty of evidence.
Conclusion The findings show potential for better outcomes in the intervention; however, the evidence remains inconclusive highlighting a large research gap in ulcer treatment and warrant better-designed clinical trial
A randomised Trial of Autologous Blood products, leukocyte and platelet-rich fibrin (L-PRF), to promote ulcer healing in LEprosy : The TABLE trial
Introduction:
Autologous blood products like Platelet Rich Plasma (PRP) and Leukocyte and Platelets Rich Fibrin (L-PRF) have been used for many years across many types of skin ulcers. However, the effectiveness of autologous blood products on wound healing is not well established.
Methods:
We evaluated the āsecond generationā autologous product- Leukocyte and Platelet- Rich Fibrin (L-PRF). Our trial was undertaken on patients suffering from neuropathic leprosy ulcers at the Anandaban hospital which serves the entire country of Nepal. We conducted a 1:1 (n = 130) individually randomised trial of L-PRF (intervention) vs. normal saline dressing (control) to compare rate of healing and time to complete healing. Rate of healing was estimated using blind assessments of ulcer areas based on three different measurement methods. Time to complete healing was measured by the local unblinded clinicians and by blind assessment of ulcer images.
Results:
The point estimates for both outcomes were favourable to L-PRF but the effect sizes were small. Unadjusted mean differences (intervention vs control) in mean daily healing rates (cm2) were respectively 0.012 (95% confidence interval 0.001 to 0.023, p = 0.027); 0.016 (0.004 to 0.027, p = 0.008) and 0.005 (-0.005 to 0.016, p = 0.313) across the three measurement methods. Time to complete healing at 42 days yielded Hazard Ratios (unadjusted) of 1.3 (0.8 to 2.1, p = 0.300) assessed by unblinded local clinicians and 1.2 (0.7 to 2.0, p = 0.462) on blind assessment.
Conclusion:
Any benefit from L-PRF appears insufficient to justify routine use in care of neuropathic ulcers in leprosy.
Trial registration:
ISRCTN14933421. Date of trial registration: 16 June 2020
An individual randomised efficacy trial of autologous blood products, leukocyte and platelet-rich fibrin (L-PRF), to promote ulcer healing in leprosy in Nepal : the TABLE trial protocol
Background:
Leprosy is curable with multidrug therapy and treatment in the early stages can prevent disability. However, local nerve damage can lead to injury and consequently recurring and disfiguring ulcers. The aim of this study is to evaluate the treatment of leprosy ulcers using an autologous blood product; leukocyte and platelet-rich fibrin (L-PRF) to promote healing.
Methods:
This is a single-centre study in the Anandaban Hospital, The Leprosy Mission Nepal, Kathmandu, Nepal. Consenting patients (n=130) will be individually randomised in a single-blinded, controlled trial. Participants will be 18 years of age or older, admitted to the hospital with a clean, dry and infection-free chronic foot ulcer between 2 and 20 cm2 in size. If the ulcer is infected, it will be treated before enrolment into the study. The intervention involves the application of leukocyte and platelet-rich fibrin (L-PRF) matrix on the ulcer beds during twice-weekly dressing changes. Controls receive usual care in the form of saline dressings only during their twice-weekly dressing changes. Primary outcomes are the rate of healing assessed using standardised photographs by observers blind to allocated treatment, and time to complete re-epithelialization. Follow-up is at 6 months from randomisation.
Discussion:
This research will provide valuable information on the clinical and cost-effectiveness of L-PRF in the treatment of leprosy ulcers. An additional benefit is the evaluation of the effects of treatment on quality of life for people living with leprosy ulcers. The results will improve our understanding of the scalability of this treatment across low-income countries for ulcer healing in leprosy and potentially other conditions such as diabetic ulcers.
Trial registration:
ClinicalTrials.govISRCTN14933421. Registered on 16 June 202
Recommended from our members
High-Density SNP Genotyping of Tomato (Solanum lycopersicum L.) Reveals Patterns of Genetic Variation Due to Breeding
The effects of selection on genome variation were investigated and visualized in tomato using a high-density single nucleotide polymorphism (SNP) array. 7,720 SNPs were genotyped on a collection of 426 tomato accessions (410 inbreds and 16 hybrids) and over 97% of the markers were polymorphic in the entire collection. Principal component analysis (PCA) and pairwise estimates of F-st supported that the inbred accessions represented seven sub-populations including processing, large-fruited fresh market, large-fruited vintage, cultivated cherry, landrace, wild cherry, and S. pimpinellifolium. Further divisions were found within both the contemporary processing and fresh market sub-populations. These sub-populations showed higher levels of genetic diversity relative to the vintage sub-population. The array provided a large number of polymorphic SNP markers across each sub-population, ranging from 3,159 in the vintage accessions to 6,234 in the cultivated cherry accessions. Visualization of minor allele frequency revealed regions of the genome that distinguished three representative sub-populations of cultivated tomato (processing, fresh market, and vintage), particularly on chromosomes 2, 4, 5, 6, and 11. The PCA loadings and F-st outlier analysis between these three sub-populations identified a large number of candidate loci under positive selection on chromosomes 4, 5, and 11. The extent of linkage disequilibrium (LD) was examined within each chromosome for these sub-populations. LD decay varied between chromosomes and sub-populations, with large differences reflective of breeding history. For example, on chromosome 11, decay occurred over 0.8 cM for processing accessions and over 19.7 cM for fresh market accessions. The observed SNP variation and LD decay suggest that different patterns of genetic variation in cultivated tomato are due to introgression from wild species and selection for market specialization
- ā¦