296 research outputs found
Flow reactors for the continuous synthesis of garlic metabolites
Garlic secondary metabolites are organosulfur compounds that possess prophylactic properties. The chemical composition of garlic oil extracts consists of a combination of these compounds. The instability of a major component, allicin 5, limits the commercial viability of garlic oil extracts.
The synthesis of garlics organosulfur compounds has been performed in batch reactors. In this thesis, flow reactors were utilised to improve the throughput, reduce the operating conditions.
The thermolysis of allicin 5 is the solitary approach to produce the garlic metabolite, ajoene 14. Ajoene 14 has greater stability compared to allicin 5 that possesses interesting biological activity. The primary three-step synthesis investigated consisted of dialkyl polysulfide synthesis, subsequent oxidation and finally the terminal thermolysis.
In addition, other garlic metabolites have also been produced. The synthesis of unsymmetrical monosulfides and their subsequent oxidation was investigated using novel heterogeneous packed-bed flow reactors. The stable amino acid, alliin 15, is the precursor of allicin 5. Alliin 15 was also synthesised in homogeneous flow mode. The telescoped synthesis of alliin 15 was successfully completed using a semi-batch reactor.
Development of novel approaches to synthesise garlics organosulfur compounds is reported in this thesis. Finally, the flow reactor systems, experimental details and characterisation of the compounds are described
Training in pediatric neurogastroenterology and motility across Europe: a survey of the ESPGHAN National Societies Network 2016-2019
BACKGROUND
Pediatric gastrointestinal motility disorders present significant challenges for diagnosis and management, emphasizing the need for appropriate training in Pediatric Neurogastroenterology and Motility (PNGM). The aim of this survey, part of a comprehensive survey on training in pediatric gastroenterology, hepatology and nutrition, was to evaluate training related to PNGM across European training centers.
METHOD
Standardized questionnaires were collected from training centers through the National Societies Network of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN), from June 2016 to December 2019.
RESULTS
In total, 100 training centers from 19 countries participated in the survey. Dedicated PNGM clinics were available in 22 centers; pH-monitoring in 60; pH/impedance in 66; standard manometry in 37; and high-resolution manometry in 33. If all motility studies were performed partially or fully by the trainees, the median (range) annual numbers/per trainee were as follows: pH-monitoring 30 (1-500); pH/impedance 17 (1-131); standard manometries 10 (1-150); and high-resolution manometries 8 (1-75). The motility assessment was performed by pediatric gastroenterologists (43 centers); adult gastroenterologists (10 centers); pediatric surgeons (5 centers); and both pediatric gastroenterologists and pediatric surgeons (9 centers). Annual numbers ≤10 for pH-monitoring, pH/impedance, standard manometries and high-resolution manometries were reported by 7 (12%), 15 (23%), 11 (30%) and 14 (42%) centers, respectively.
CONCLUSIONS
Significant differences exist in PNGM-related infrastructure, staff and procedural volumes at training centers across Europe. ESPGHAN and the National Societies should take initiatives to ensure the acquisition of competence in PNGM-related knowledge and skills, and develop strategies for assessment and accreditation.An infographic is available for this article at: http://www.annalsgastro.gr/files/journals/1/earlyview/2022/Infographic-AG6486.pdf
Association of training standards in pediatric gastroenterology, hepatology and nutrition in European training centers with formal national recognition of the subspecialty: a survey of the ESPGHAN National Societies Network 2016-2019
BACKGROUND
This survey evaluated the effects of the recognition of pediatric gastroenterology, hepatology and nutrition (PGHN) on European PGHN training centers.
METHOD
Standardized questionnaires were collected from training centers via the presidents/representatives of the National Societies Network of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition, from June 2016 to December 2019.
RESULTS
A total of 100 training centers from 19 countries participated in the survey: 55 from 12 countries where PGHN is formally recognized (Group 1) and 45 from 7 countries where it is not (Group 2). Training centers in Group 2 were less likely to have an integrated endoscopy suite, a written training curriculum and a training lead (P=0.059, P<0.001 and P=0.012, respectively). Trainees in Group 2 were less likely to be exposed to an adequate number of diagnostic endoscopies, while no differences were found in relation to liver biopsies. Half of the training centers in both Groups do not have dedicated beds for PGHN patients, while in 64% and 58%, respectively, trainees do not participate in on-call programs for PGHN emergencies. Research training is mandatory in 26% of the centers. The duration of training, as well as the assessment and accreditation policies, vary between countries.
CONCLUSIONS
This study has revealed significant discrepancies and gaps in infrastructure and training programs, training leadership, and assessment of training and certification across European training centers in PGHN. Strategies to support the recognition of PGHN and to standardize and improve training conditions should be developed and implemented.An infographic is available for this article at: http://www.annalsgastro.gr/files/journals/1/earlyview/2022/Infographic_AG-6496.pdf
Pediatric endoscopy training across Europe: a survey of the ESPGHAN National Societies Network 2016-2019
Background and study aims  The ability to perform endoscopy procedures safely and effectively is a key aspect of quality clinical care in Pediatric Gastroenterology, Hepatology and Nutrition (PGHN). The aim of this survey, which was part of a global survey on PGHN training in Europe, was to assess endoscopy training opportunities provided across Europe. Methods  Responses to standardized questions related to endoscopy training were collected from training centers across Europe through the presidents/representatives of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition National Societies from June 2016 to December 2019. Results  A total of 100 training centers from 19 countries participated in the survey. In 57 centers, the endoscopy suit was attached to the PGHN center, while in 23, pediatric endoscopies were performed in adult endoscopy facilities. Ninety percent of centers reported the availability of specialized endoscopy nurses and 96 % of pediatric anesthetists. Pediatric endoscopies were performed by PGHN specialists in 55 centers, while 31 centers reported the involvement of an adult endoscopist and 14 of a pediatric surgeon. Dividing the number of procedures performed at the training center by the number of trainees, ≤ 20 upper, lower, or therapeutic endoscopies per trainee per year were reported by 0 %, 23 %, and 56 % of centers, respectively, whereas ≤ 5 wireless capsule endoscopies per trainee per year by 75 %. Only one country (United Kingdom) required separate certification of competency in endoscopy. Conclusions  Differences and deficiencies in infrastructure, staffing, and procedural volume, as well as in endoscopy competency assessment and certification, were identified among European PGHN training centers limiting training opportunities in pediatric endoscopy
Notes on the Music: A social data infrastructure for music annotation
Beside transmitting musical meaning from composer to reader, symbolic music notation affords the dynamic addition of layers of information by annotation. This allows music scores to serve as rudimentary communication frameworks. Music encodings bring these affordances into the digital realm; though annotations may be represented as digital pen-strokes upon a score image, they must be captured using machine-interpretable semantics to fully benefit from this transformation. This is challenging, as annota- tors’ requirements are heterogeneous, varying both across different types of user (e.g., musician, scholar) and within these groups, de- pending on the specific use-case. A hypothetical all-encompassing tool catering to every conceivable annotation type, even if it were possible to build, would vastly complicate user interaction. This additional complexity would significantly increase cognitive load and impair usability, particularly in dynamic real-time usage con- texts, e.g., live annotation during music rehearsal or performance. To address this challenge, we present a social data infrastructure that facilitates the creation of use-case specific annotation toolkits. Its components include a selectable-score module that supports customisable click-and-drag selection of score elements (e.g., notes, measures, directives); the Web Annotations data model, extended to support the creation of custom, Web-addressable annotation types supporting the specification and (re-)use of annotation palettes; and the Music Encoding and Linked Data (MELD) Javascript client library, used to build interfaces that map annotation types to render- ing and interaction handlers. We have extended MELD to support the Solid platform for social Linked Data, allowing annotations to be privately stored in user-controlled Personal Online Datastores (Pods), or selectively shared or published. To demonstrate the feasi- bility of our proposed approach, we present annotation interfaces employing the outlined infrastructure in three distinct use-cases: scholarly communication; music rehearsal; and rating during music listening
Recommended from our members
Transcript specific regulation of expression influences susceptibility to multiple sclerosis.
Genome-wide association studies (GWAS) have identified over 100 loci containing single nucleotide variants (SNVs) that influence the risk of developing multiple sclerosis (MS). Most of these loci lie in non-coding regulatory regions of the genome that are active in immune cells and are therefore thought to modify risk by altering the expression of key immune genes. To explore this hypothesis we screened genes flanking MS-associated variants for evidence of allele specific expression (ASE) by quantifying the transcription of coding variants in linkage disequilibrium with MS-associated SNVs. In total, we were able to identify and successfully analyse 200 such coding variants (from 112 genes) in both CD4+ and CD8+ T cells from 106 MS patients and 105 controls. Fifty-six of these coding variants (from 43 genes) showed statistically significant evidence of ASE in one or both cell types. In the Lck interacting transmembrane adaptor 1 gene (LIME1), for example, we were able to show that in both cell types, the MS-associated variant rs2256814 increased the expression of some transcripts while simultaneously reducing the expression of other transcripts. In CD4+ cells from an additional independent set of 96 cases and 93 controls we were able to replicate the effect of this SNV on the balance of alternate LIME1 transcripts using qPCR (p = 5 × 10-24). Our data thus indicate that some of the MS-associated SNVs identified by GWAS likely exert their effects on risk by distorting the balance of alternate transcripts rather than by changing the overall level of gene expression
Study protocol: a double blind randomised control trial of high volume image guided injections in achilles and patellar tendinopathy in a young active population
Background: Chronic tendinopathy is a significant problem particularly in active populations limiting sporting and
occupational performance. The prevalence of patellar tendinopathy in some sports is near 50% and the incidence
of lower limb tendinopathy is 1.4% p.a. in the UK Military. Management includes isometric, eccentric, heavy slow
resistance exercises and extracorporeal shockwave therapy (ESWT). Often these treatments are inadequate yet there
is no good evidence for injection therapies and success rates from surgery can be as low as 50%. High Volume Image Guided Injection (HVIGI) proposes to strip away the neovascularity and disrupt the nerve
ingrowth seen in chronic cases and has shown promising results in case series. This study aims to investigate the efficacy of HVIGI in a randomised controlled trial (RCT).
Methods: RCT comparing 40ml HVIGI, with or without corticosteroid, with a 3ml local anaesthetic sham-control injection. Ninety-six participants will be recruited. Inclusion criteria: male, 18–55 years old, chronic Achilles or patellar tendinopathy of at least 6 months, failed conservative management including ESWT, and Ultrasound (US) evidence of neovascularisation, tendon thickening and echogenic changes. Outcome measures will be recorded at baseline, 6 weeks, 3, 6 and 12 months. Primary outcome measures include The Victoria Institute of Sport Assessments for Achilles and patellar tendinopathy (VISA-A and VISA-P) and VAS pain. Secondary outcome measures include
Modified Ohberg score, maximum tendon diameter and assessment of hypoechoic appearance on US, and Functional Activity Assessment.
Discussion: Despite previous interventional trials and reviews there is still insufficient evidence to guide injectable
therapy for chronic tendinopathy that has failed conservative treatment. The scant evidence available suggests HVIGI has the greatest potential however there is no level one RCT evidence to support this. Investigating the efficacy of HVIGI against control in a RCT and separating the effect of HVIGI and corticosteroid will add high level
evidence to the management of chronic tendinopathy resistant to conservative treatment
A monoclonal antibody raised against a thermo-stabilised β1-adrenoceptor interacts with extracellular loop 2 and acts as a negative allosteric modulator of a sub-set of 1- adrenoceptors expressed in stable cell lines
Recent interest has focused on antibodies that can discriminate between different receptor conformations. Here we have characterised the effect of a monoclonal antibody (mAb3), raised against a purified thermo-stabilised turkey β1-adrenoceptor (β1AR-m23 StaR), on β1-ARs expressed in CHO-K1 or HEK 293 cells. Immunohistochemical and radioligand-binding studies demonstrated that mAb3 was able to bind to ECL2 of the tβ1-AR, but not its human homologue. Specific binding of mAb3 to tβ1-AR was inhibited by a peptide based on the turkey, but not the human, ECL2 sequence. Studies with [3H]-CGP 12177 demonstrated that mAb3 prevented the binding of orthosteric ligands to a subset (circa 40%) of turkey 1-receptors expressed in both CHO K1 and HEK 293 cells. MAb3 significantly reduced the maximum specific binding capacity of [3H]-CGP-12177 without influencing its binding affinity. Substitution of ECL2 of tβ1-AR with its human equivalent, or mutation of residues D186S, P187D, Q188E prevented the inhibition of [3H]-CGP 12177 binding by mAb3. MAb3 also elicited a negative allosteric effect on agonist-stimulated cAMP responses. The identity of the subset of turkey β1-adrenoceptors influenced by mAb3 remains to be established but mAb3 should become an important tool to investigate the nature of β1-AR conformational states and oligomeric complexes
Binding of Transcription Factor GabR to DNA Requires Recognition of DNA Shape at a Location Distinct from its Cognate Binding Site
Mechanisms for transcription factor recognition of specific DNA base sequences are well characterized and recent studies demonstrate that the shape of these cognate binding sites is also important. Here, we uncover a new mechanism where the transcription factor GabR simultaneously recognizes two cognate binding sites and the shape of a 29 bp DNA sequence that bridges these sites. Small-angle X-ray scattering and multi-angle laser light scattering are consistent with a model where the DNA undergoes a conformational change to bend around GabR during binding. In silico predictions suggest that the bridging DNA sequence is likely to be bendable in one direction and kinetic analysis of mutant DNA sequences with biolayer interferometry, allowed the independent quantification of the relative contribution of DNA base and shape recognition in the GabR–DNA interaction. These indicate that the two cognate binding sites as well as the bendability of the DNA sequence in between these sites are required to form a stable complex. The mechanism of GabR–DNA interaction provides an example where the correct shape of DNA, at a clearly distinct location from the cognate binding site, is required for transcription factor binding and has implications for bioinformatics searches for novel binding sites
- …