QA Group Research Articles

Highly durable anion exchange membranes with sustainable mitigation of hydroxide attacks for water electrolysis

Low hydroxide conductivity and insufficient alkaline stability are the main problems currently facing anion exchange membranes (AEMs). Conventional quaternary ammonium groups have limited resistance to attack by hydroxide roots. In this paper, quaternary ammonium-type (Cn-PFCO (n = 2, 5)) perfluoroanion exchange polymers with carbonyl side chains were synthesized. The C5–PFCO exhibited an impressive conductivity of 113.4 mS cm−1 at 80 °C, and remarkably, it retained 86.87% of its initial conductivity even after 15 days of immersion in a 1 M KOH aqueous solution. This excellent alkali resistance is due to the generation of intermediate oxygen anions from OH− and carbonyl groups through a reversible reaction. These anions effectively reduce the likelihood of SN2 attack by diminishing the electrostatic potential of the QA groups from Density Functional Theory (DFT) calculations. The electrostatic potential of C2–PFCO is 6.28 eV, while it decreases to 2.69 eV after the formation of intermediate anions. Furthermore, we also used the prepared AEM for pure water electrolysis to explore its performance. The electrochemical performance of AEMWE exhibited remarkable results when supplied with pure water, demonstrating an impressive current density of 262 mA cm−2 at 1.9 V. This study introduces a novel strategy for concurrently enhancing hydroxide conductivity and alkali resistance in AEMs by analyzing the potential for further improvement in AEMs' alkali resistance.

High performance quaternary ammonium-functionalized polybenzoxazine-based anion exchange membranes

Two kinds of benzoxazine monomers were synthesized by Mannich reaction with N,N-dimethyl-p-phenylenediamine and N,N-dimethylethylenediamine using polyformaldehyde, 4,4′-dihydroxydiphenylmethane as raw materials. Subsequently, quaternary ammonium functionalization was realized by Menshutkin reaction. The aromatic amine-based quaternary ammonium-functionalized polybenzoxazine (AQPBZ) and aliphatic amine-based quaternary ammonium-functionalized polybenzoxazine (LQPBZ) were synthesized by ring-opening polymerization. Polybenzoxazine anion exchange membrane (AEM) was prepared by solution casting method. The AQPBZ and LQPBZ AEMs exhibit micro-phase separated morphology clearly. LQPBZ AEM displays more large ion clusters and ion conductive channels due to the flexible alkyl connection between QA group and polybenzoxazine skeleton. AQPBZ and LQPBZ AEMs have the ionic conductivity of 75.5 mS/cm and 86.3 mS/cm at 80 °C and 100% relative humidity, respectively. AQPBZ and LQPBZ AEMs show excellent alkaline stability. After treated with 6 M sodium hydroxide solution at 80 °C for 240 h, they manitained the 49.8 mS/cm and 50.2 mS/cm, respectively. They also exhibit good oxidation stability and thermal stability. Their oxidation weight losses are 4.1% and 7.2% through Fenton test, respectively. Their Td5s are 325 °C and 289 °C, respectively.

Cytotoxicity and Microbiological Properties of Copolymers Comprising Quaternary Ammonium Urethane-Dimethacrylates with Bisphenol A Glycerolate Dimethacrylate and Triethylene Glycol Dimethacrylate.

Using dental composite restorative materials with a copolymeric matrix chemically modified towards bioactive properties can help fight secondary caries. In this study, copolymers of 40 wt.% bisphenol A glycerolate dimethacrylate, 40 wt.% quaternary ammonium urethane-dimethacrylates (QAUDMA-m, where m represents 8, 10, 12, 14, 16 and 18 carbon atoms in the N-alkyl substituent), and 20 wt.% triethylene glycol dimethacrylate (BG:QAm:TEGs) were tested for (i) cytotoxicity on the L929 mouse fibroblast cell line; (ii) fungal adhesion, fungal growth inhibition zone, and fungicidal activity against C. albicans; and (iii) bactericidal activity against S. aureus and E. coli. BG:QAm:TEGs had no cytotoxic effects on L929 mouse fibroblasts because the reduction of cell viability was less than 30% compared to the control. BG:QAm:TEGs also showed antifungal activity. The number of fungal colonies on their surfaces depended on the water contact angle (WCA). The higher the WCA, the greater the scale of fungal adhesion. The fungal growth inhibition zone depended on the concentration of QA groups (xQA). The lower the xQA, the lower the inhibition zone. In addition, 25 mg/mL BG:QAm:TEGs suspensions in culture media showed fungicidal and bactericidal effects. In conclusion, BG:QAm:TEGs can be recognized as antimicrobial biomaterials with negligible biological patient risk.

Transcriptome-wide analysis of RNA m6A methylation regulation of muscle development in Queshan Black pigs

BackgroundN6-methyladenosine (m6A) refers to the methylation modification of N6 position of RNA adenine, a dynamic reversible RNA epigenetic modification that plays an important regulatory role in a variety of life processes. In this study, we used MeRIP-Seq and RNA-Seq of the longissimus dorsi (LD) muscle of adult (QA) and newborn (QN) Queshan Black pigs to screen key genes with m6A modification involved in muscle growth by bioinformatics analysis.ResultsA total of 23,445 and 25,465 m6A peaks were found in the whole genomes of QA and QN, respectively. Among them, 613 methylation peaks were significantly different (DMPs) and 579 genes were defined as differentially methylated genes (DMGs). Compared with the QN group, there were 1,874 significantly differentially expressed genes (DEGs) in QA group, including 620 up-regulated and 1,254 down-regulated genes. In order to investigate the relationship between m6A and mRNA expression in the muscle of Queshan Black pigs at different periods, a combined analysis of MeRIP-Seq and RNA-Seq showed that 88 genes were significantly different at both levels. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes results showed that DEGs and DMGs were mainly involved in skeletal muscle tissue development, FoxO signaling pathway, MAPK signaling pathway, insulin signaling pathway, PI3K–Akt signaling pathway, and Wnt signaling pathway. Four DEGs (IGF1R, CCND2, MYOD1 and FOS) and four DMGs (CCND2, PHKB, BIN1 and FUT2), which are closely related to skeletal muscle development, were selected as candidate genes for verification, and the results were consistent with the sequencing results, which indicated the reliability of the sequencing results.ConclusionsThese results lay the foundation for understanding the specific regulatory mechanisms of growth in Queshan Black pigs, and provide theoretical references for further research on the role of m6A in muscle development and breed optimization selection.

Abstract OT1-09-02: ATNEC: A multicentre, randomized trial investigating whether axillary treatment can be avoided in T1-3N1M0 breast cancer patients with no residual cancer in the axillary lymph nodes after neoadjuvant chemotherapy

Abstract Background: For patients who are node positive at presentation and are found to have a complete nodal tumour response (ypN0) post-neoadjuvant chemotherapy (NACT), we do not yet know whether local axillary therapy can be modified based on the response to NACT. ATNEC addresses whether axillary treatment can be de-escalated, post-surgery, in T1-3N1M0 breast cancer patients who have no residual nodal disease post-NACT. Methods: Design: ATNEC is a phase III, randomized (1:1), multi-centre trial, with embedded economic evaluation. Patients with proven axillary node metastases on needle biopsy receive NACT followed by sentinel node biopsy (SNB). If the sentinel nodes have converted to ypN0, ATNEC randomizes patients to axillary treatment (nodal radiotherapy [ART] or axillary nodal clearance [ANC]) vs. no further axillary treatment. Stratification: Institution, type of surgery (breast conserving surgery vs mastectomy), receptor status (triple negative vs HER2 positive vs ER positive and/or PR positive and HER2 negative). Inclusion criteria: • Age ≥ 18 • Male or female • T1-3N1M0 breast cancer at diagnosis (pre-NACT) • FNA or core biopsy confirmed axillary nodal metastases at presentation • ER and HER2 status evaluated on primary tumour • Received standard NACT as per local guidelines • Imaging of the axilla to assess response to NACT • Dual tracer SNB post-NACT and at least 3 nodes removed (sentinel nodes and marked node). o If a single tracer is used, the patient is eligible if the involved node is marked pre-NACT and at least 3 nodes removed (including the marked node) o If axillary node sampling is performed following failed localization of sentinel nodes, patient is eligible if at least 3 nodes removed (including the marked node). o If node is not marked, or marked node is not removed, patient is eligible if the histology report shows evidence of down-staging with complete pathological response in at least one node of the 3 removed nodes. • No evidence of nodal metastases post-NACT (ypN0) Exclusion criteria: • Bilateral invasive breast cancer • SNB prior to NACT • Previous ipsilateral axillary nodal surgery • Previous cancer within last 5 years or concomitant malignancy Aims: To assess whether omitting further axillary treatment (ART or ANC) for patients with early stage breast cancer and axillary nodal metastases on needle biopsy - who post NACT have no residual nodal disease on SNB (ypN0) - is non-inferior to axillary treatment in terms of disease-free survival, and whether lymphoedema is reduced at 5 years. Statistical methods: All analyses will be carried out on an intention-to-treat basis to preserve randomization, avoid bias from exclusions and preserve statistical power. Radiotherapy Quality Assurance: ATNEC has in-built radiotherapy QA coordinated by National Radiotherapy Trials QA (RTTQA) group. The RTQA monitors trial protocol compliance ensuring clinical outcomes reflect differences in randomization schedules rather than departures from the protocol. ATNEC is the only trial in the UK that offers QA for IMC radiotherapy. Screening Data: ATNEC collects screening data to monitor acceptance rates and reasons why patients decline the trial to identify ways to improve recruitment. Screening data until 30-Jun-22 shows that 69% of eligible patients were approached (244/354) and, of those approached, 45% were consented (109/244). For the 81 patients who declined, the most common reasons were; preference for axillary treatment (31%), preference for no axillary treatment (10%), no reason documented (23%) and ineligibility (21%). ClinicalTrials.gov: NCT04109079 Target accrual: 1900 Target sites: 100 Trial Status: Recruiting. As of 30-Jun-22: 52 sites open, 158 patients enrolled, 54 randomised. ATNEC is open to new sites and international collaboration. Citation Format: Amit Goyal, Sophie Nicholls, Andrea Marshall, Natalie Hammonds, Duncan Wheatley, Beatrix Elsberger, Janice Rose, Helen-Teresa Edwards, Roeum Butt, Abeer Shaaban, Shama Puri, Samreen Ahmed, Tara Homer, Luke Vale, Julie Bruce, Sophie J. Gasson, Helen Higgins, Janet A. Dunn. ATNEC: A multicentre, randomized trial investigating whether axillary treatment can be avoided in T1-3N1M0 breast cancer patients with no residual cancer in the axillary lymph nodes after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT1-09-02.

Extreme pH‐Resistant, Highly Cation‐Selective Poly(Quaternary Ammonium) Membranes Fabricated via Menshutkin Reaction‐Based Interfacial Polymerization

AbstractMembrane‐based separation technologies have attracted significant interest from various industries owing to their high process efficiency. However, the wider applications of conventional polyamide (PA) thin‐film composite (TFC) membranes are limited by their poor pH stability and low cation selectivity, necessitating the development of membranes with advanced chemistries. Herein, an extreme pH‐resistant, highly cation‐selective TFC membrane is fabricated by synthesizing a crosslinked poly(quaternary ammonium) (PQA) selective layer on a polyethylene support via Menshutkin reaction‐based interfacial polymerization (Men‐IP). The Men‐IP process produces a thin, densely crosslinked, and positively charged PQA permselective layer without hydrolysis‐prone functional groups. The fabricated PQA membrane features a highly selective molecular density that significantly exceeds those of previously reported membranes with non‐PA chemistries. Moreover, the PQA membrane exhibits remarkably high rejection (>90%) and selectivity for divalent cations owing to the exceptionally strong positive charge imparted by its abundant cationic QA groups. More importantly, the PQA membrane displays ultrahigh pH stability under both extremely acidic (1.5 m H2SO4) and alkaline (5 m NaOH) conditions for 28 days. No other membrane reported in the literature demonstrates such excellent pH stability. This strategy opens a new route for fabricating highly selective membranes that can be used in harsh pH environments.

High-flow arteriovenous fistula and myocardial fibrosis in hemodialysis patients with non-contrast cardiac magnetic resonance imaging.

BackgroundThe role of high-flow arteriovenous fistula (AVF) in cardiovascular morbidity in hemodialysis (HD) patients is very likely under-recognized. We assessed the relationship between high access flow (Qa) and myocardial fibrosis in HD patients.MethodsMyocardial fibrosis was assessed by native T1 relaxation times on non-contrast cardiac magnetic resonance imaging and a potential marker of fibrosis. Serum levels of galectin-3, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and monocyte chemoattractant protein 1 (MCP-1) were measured in 101 HD patients who underwent regular monitoring of AVF Qa. A high-flow AVF was defined as a Qa >2 L/min.ResultsHemodialysis patients showed significantly higher galectin-3 value and increased T1 relaxation time compared to healthy volunteers, suggesting increased myocardial fibrosis in uremic cardiomyopathy. In HD patients, 20 (19.8%) had a Qa > 2L/min, and they had significantly higher cardiac output, cardiac index, left ventricular mass, and increased T1 times than those with a Qa ≤ 2 L/min. Also, serum galectin-3 and NT-proBNP levels were much higher in the high Qa group, indicating a close relationship between the high Qa, increased myocardial fibrosis, and the risk of heart failure (HF) in HD patients. It is interesting that a higher AVF Qa for myocardial fibrosis was independent of several traditional cardiovascular risk factors as well as serum levels of NT-proBNP and MCP-1.ConclusionsA supra-physiologically high Qa can be related to myocardial fibrosis and increased risk of HF in HD patients. Regular Qa monitoring could allow early detection of a high-flow AVF that could arise cardiac complications.

ATNEC: A multicenter, randomized trial investigating whether axillary treatment can be avoided in patients with T1-3N1M0 breast cancer with no residual cancer in the lymph glands after neoadjuvant chemotherapy.

TPS615 Background: Neoadjuvant chemotherapy (NACT) results in eradication of cancer in the axillary nodes in 40-70% of patients. This raises questions about the benefit of further axillary treatment in patients with no evidence of residual nodal disease (ypN0) post NACT. Methods: Design: ATNEC is a phase 3, randomized (1:1), multi-center UK trial, with embedded economic evaluation. Patients with proven axillary node metastases on needle biopsy receive NACT followed by sentinel node biopsy (SNB). If the sentinel nodes have converted to benign (ypN0), ATNEC randomly assigns patients to axillary treatment (nodal radiotherapy [ART] or axillary nodal clearance [ALND]) vs no further axillary treatment. Stratification: Institution, type of surgery (breast conserving surgery vs mastectomy), receptor status (triple negative vs HER2 positive vs ER positive and/or PR positive and HER2 negative).Inclusion criteria: Age ≥ 18; Male or female; T1-3N1M0 breast cancer at diagnosis (pre-NACT); FNA or core biopsy confirmed axillary nodal metastases at presentation; ER and HER2 status evaluated on primary tumor; Received standard NACT as per local guidelines; Imaging of the axilla to assess response to NACT;Dual tracer SNB post-NACT and at least 3 nodes removed (sentinel nodes and marked node): If a single tracer is used, the patient is eligible if the involved node is marked pre-NACT and at least 3 nodes removed (including the marked node), If axillary node sampling is performed following failed localization of sentinel nodes, patient is eligible if at least 3 nodes removed (including the marked node), If node is not marked, or marked node is not removed, patient is eligible if the histology report shows evidence of down-staging with complete pathological response in at least one node and at least 3 nodes removed; No evidence of nodal metastases post NACT (ypN0). Exclusion criteria: Bilateral invasive breast cancer; SNB prior to NACT; Previous ipsilateral axillary nodal surgery; Previous cancer within last 5 years or concomitant malignancy. Aims: To assess whether omitting further axillary treatment (ALND & ART) for patients with early-stage breast cancer and axillary nodal metastases on needle biopsy - who after NACT have no residual nodal disease on SNB (ypN0) - is non-inferior to axillary treatment in terms of disease-free survival, and reduces lymphoedema at 5 years. Statistical methods: All analyses will be carried out on an intention-to-treat basis to preserve randomization, avoid bias from exclusions and preserve statistical power. Radiotherapy Quality Assurance: Study has in-built radiotherapy QA program that will be coordinated by National Radiotherapy Trials QA (RTTQA) group. Target accrual: 1,900 Status: Recruiting. As of 11-Feb-2022, 39 sites open, 87 patients enrolled, 31 randomized. Clinical trial information: NCT04109079.

Abstract OT1-04-01: ATNEC: A multi-centre, randomised trial investigating whether axillary treatment can be avoided in T1-3N1M0 breast cancer patients with no residual cancer in the lymph glands after neoadjuvant chemotherapy (clinicaltrials.gov: nct04109079)

Abstract Background: For patients who are node positive to start at presentation and are found to have a complete nodal tumour response (ypN0) post neoadjuvant chemotherapy (NACT), we do not yet know whether local axillary therapy can be modified based on the response to NACT. ATNEC randomised trial specifically address axillary management following NACT in patients with proven axillary node metastases. Methods: Design: ATNEC is a phase III, randomised (1:1), multi-centre trial, with embedded economic evaluation. Patients with proven axillary node metastases on needle biopsy receive NACT followed by sentinel node biopsy (SNB). If the sentinel nodes have converted to benign (ypN0), ATNEC randomly assigns patients to axillary treatment (nodal radiotherapy or axillary nodal clearance) vs. no axillary treatment (without further surgery). Aims: To assess whether, omitting further axillary treatment (ALND and ART) for patients with early stage breast cancer and axillary nodal metastases on needle biopsy - who after NACT have no residual nodal disease on SNB - is non-inferior to axillary treatment in terms of disease free survival, and reduces the risk of lymphoedema at 5 years. Stratification: Institution, type of surgery (breast conserving surgery [BCS] vs mastectomy), receptor status (triple negative vs HER2 positive vs ER status positive and/or PR status positive and HER2 negative). Inclusion criteria:. • Age ≥ 18. • Male or female. • T1-3N1M0 breast cancer at diagnosis (pre-NACT). • FNA or core biopsy confirmed axillary nodal metastases at presentation. • ER and HER2 status evaluated on primary tumour. • Received standard NACT as per local guidelines. • Imaging assessment of the axilla at completion of NACT. • Dual tracer SNB after NACT and at least 3 nodes removed (sentinel nodes and marked node). o If a single tracer is used, the patient is eligible if the involved node is marked before NACT and at least 3 nodes removed (including the marked node). o If axillary node sampling is performed following failed localisation of sentinel nodes, patient is eligible if at least 3 nodes removed (including the marked node). o If node is not marked, or marked node is not removed, patient is eligible if the histology report shows evidence of down-staging with complete pathological response in at least one node and at least 3 nodes removed. • No evidence of nodal metastases post NACT (ypN0). Exclusion criteria:. • Bilateral invasive breast cancer. • SNB prior to NACT. • Previous ipsilateral axillary nodal surgery. • Previous cancer within last 5 years or concomitant malignancy. Radiotherapy Quality Assurance: ATNEC has in-built radiotherapy QA programme that is coordinated by National Radiotherapy Trials QA (RTTQA) group. Target accrual: 1900 Number of sites: 100 Trial Status: Recruiting. Trial is open to new sites. Disclaimer: This study is funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme (Reference - HTA NIHR128311). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. Citation Format: Amit Goyal, Sophie Cramp, Andrea Marshall, Duncan Wheatley, Natalie Hammonds, Shama Puri, Tara Homer, Luke Vale, Roeum Butt, Romaana Mir, Janice Rose, Helen Teresa Edwards, Samreen Ahmed, Abeer Shaaban, Beatrix Elsberger, Julie Bruce, Sophie Gasson, Valerie Speirs, Jacqui Shaw, Helen Higgins, Janet Dunn. ATNEC: A multi-centre, randomised trial investigating whether axillary treatment can be avoided in T1-3N1M0 breast cancer patients with no residual cancer in the lymph glands after neoadjuvant chemotherapy (clinicaltrials.gov: nct04109079) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-04-01.

High-performance COF-based composite anion exchange membrane sandwiched by GO layers for alkaline H2/O2 fuel cell application

With well-defined structure and high stability, covalent organic framework (COF) inspires the preparation of new ion-conducting materials for anion exchange membrane (AEM) in alkaline fuel cell. In order to reveal the influence of micro-nano structure within COF ordered channels on the hydroxide diffusion, we construct a multi-dimensional composite membrane by combining two-dimensional lamellar COF with one-dimensional polymer chains. The quaternary ammonium-modified COF-LZU1 (QAmCOF-LZU1) is incorporated into quaternized poly (2,6-dimethyl-1,4-phenylene oxide) (QAPPO) to fabricate QAmCOF-LZU1/PPO composite membranes. The rapidly diffusion of hydroxide ions in the first solvent shell formed by the huge amount of quaternary ammonium groups in the ordered COF channels is investigated by molecular dynamics simulations. Afterwards, sulfonated graphene oxide (GO) is coated on both surfaces of the membranes via ionic interactions and π-π interactions to obtain GO@QAmCOF-LZU1/PPO sandwich membranes, which would avoid excessive swelling of membranes and leakage of QA groups. Especially, the GO-sandwiched membrane exhibits strikingly high stabilities and excellent H2/O2 fuel cell performance with a peak power density of 242 mW cm−2 at 60 °C. This study provides an effective strategy to construct ion-conducting COF-based composite membranes for high-performance alkaline fuel cell.

Axillary management in T1-3N1M0 breast cancer patients with needle biopsy proven nodal metastases at presentation after neoadjuvant chemotherapy (ATNEC).

TPS600 Background: Neoadjuvant chemotherapy (NACT) results in eradication of cancer in the axillary nodes in 40% to 70% of patients. This raises questions about the benefit of further axillary treatment in those patients with no evidence of residual nodal disease (ypN0) after NACT. Methods: Design: ATNEC is a phase 3, randomised (1:1), multi-centre trial, with embedded economic evaluation, comparing standard axillary treatment (axillary lymph node dissection [ALND] or axillary radiotherapy [ART]) with no further axillary treatment in T1-3N1M0 breast cancer patients with needle biopsy proven axillary nodal metastases, who after NACT have no residual nodal disease (ypN0) on dual tracer sentinel node biopsy (SNB) and removal of at least 3 nodes (sentinel nodes and marked involved node). Stratification: Institution, type of surgery (breast conserving surgery vs mastectomy), receptor status (triple negative vs HER2 positive vs ER positive and/or PR positive and HER2 negative). Inclusion criteria are: Age ≥ 18, Male or female, T1-3N1M0 breast cancer at diagnosis (pre-NACT), FNA or core biopsy confirmed axillary nodal metastases at presentation, ER and HER2 status evaluated on primary tumour, received standard NACT as per local guidelines, ultrasound of the axilla at completion of NACT, dual tracer SNB after NACT and at least 3 nodes removed (sentinel nodes and marked node), no evidence of nodal metastases post NACT (ypN0). Exclusion criteria are: bilateral invasive breast cancer, SNB prior to NACT, marked node not removed except where at least one node removed shows evidence of down-staging with complete pathological response e.g. fibrosis/scarring and at least 3 nodes removed, previous ipsilateral axillary surgery, previous cancer within last 5 years or concomitant malignancy except basal or squamous cell carcinoma of the skin, in situ carcinoma of the cervix, in situ or stage 1 melanoma, contra- or ipsilateral in situ breast cancer. Aims: To assess whether, omitting further axillary treatment (ALND and ART) for patients with early stage breast cancer and axillary nodal metastases on needle biopsy - who after NACT have no residual nodal disease on SNB (ypN0) - is non-inferior to axillary treatment in terms of disease free survival, and reduces the risk of lymphoedema at 5 years. Statistical methods: All analyses will be carried out on an intention-to-treat basis to preserve randomisation, avoid bias from exclusions and preserve statistical power. Radiotherapy quality assurance: Study has in-built radiotherapy QA programme that will be co-ordinated by National Radiotherapy Trials QA (RTTQA) group. Target accrual: 1900. Trial status: Recruiting. Number of sites: 100. Clinical trial information: NCT04109079.

P010: Emergency department performed renal point-of-care ultrasound (POCUS) for the assessment of obstructive uropathy: Impact of a training curriculum and ongoing educational intervention

Introduction: Hydronephrosis is the de facto measure of obstructive uropathy (OU) and can be evaluated using renal Point of Care Ultrasound (rPOCUS). This educational initiative aimed to develop an effective one-day rPOCUS curriculum and evaluate if feedback/quality assurance (QA), leads to an improvement in image acquisition and interpretation of hydronephrosis as well as comfort with the technique. Methods: Physicians were randomized into a QA or control group (NQA) and all attended a one day training session which involved acquiring rPOCUS scans with one-on-one instruction. Participants then performed POCUS scans on all ED patients where formal renal US was deemed clinically indicated. The QA group received feedback on every scan from qualified ED physicians. Overall sensitivity and specificity were calculated compared to formal scans using a chi-square test. Written QA was reviewed for future improvements. Crossover occurred at 10 weeks to allow for equal learning opportunity but analyses focused on pre-crossover data. Participants completed surveys at study start and end focusing on initiative effectiveness and barriers/comfort with POCUS measured with a likert scale (Not at all (1)-Very (7)). Results: Fourteen ED physicians participated. The most common cited barrier to utilizing rPOCUS was lack of knowledge/training (78.6%). A total of 63 POCUS scans were reviewed. Common feedback included breath-holding (69.7%), use of color doppler (48.5%) and including a transverse sweep (36.4%). Sensitivity and specificity were better in the QA versus NQA group though the difference was not significant (Se- 75.0% vs 50.0%, 95%CI: −34.0-73.4%; Sp- 89.3% vs 73.9%, 95% CI: 8.2-39.2%). Ten physicians completed the post survey; all reported improved comfort with rPOCUS in assessment of hydronephrosis (median [IQR]: Δ+2 [1-3]). At study end, the comfort rating for using only POCUS and not formal scan remained low (median [IQR]: 3.50 [1.8-4.2]). The training initiative was rated highly with a median [IQR] rating of 5.50 [4.8-7.0]. Conclusion: Although the initiative was rated highly effective and resulted in improved comfort with renal POCUS, physicians did not feel comfortable solely using POCUS without formal scan to diagnose OU. Despite the initiative's success, further educational programs are needed before rPOCUS can be safely used as the primary investigation. In the future, a greater emphasis should be placed on the commonly noted areas of improvement.

A novel approach to improve hamstring flexibility: A single-blinded randomised clinical trial.

BackgroundThe hamstrings play a major role in body posture. Shortening or tightness of the hamstrings affects postural alignment and results in possible musculoskeletal pain.ObjectivesThe aim of this study was to develop a novel approach to improve hamstring flexibility in young adults.MethodA single-blinded randomised clinical trial included 60 participants aged 18–24 with shortened hamstrings recruited from the Hashemite University, Zarqa, Jordan. The range of motion of knee extension was measured with the hip at 90° flexion using a simple goniometer to detect the level of hamstring flexibility. Participants received either a passive hamstring stretch (PS), followed by two sets of 10 tibial nerve neurodynamic technique (ND), or PS followed by three sets of 10 repetitions of active knee extension–quadriceps activation (QA), or PS only.ResultsThere was a significant improvement of hamstring flexibility in the QA group compared to the PS group (13.4 ± 12.1° vs. 6.2 ± 6.4°, p = 0.05). There was a significant improvement in hamstring flexibility post-intervention compared to pre-intervention in the PS group by 6.2 ± 6.4 (30.5 ± 10.8° vs. 36.6 ± 9.5°, p = 0.001), ND group by 9.3 ± 6.2 (26.7 ± 10.9° vs. 36.0 ± 9.5°, p = 0.001) and QA group by 13.4 ± 12.1 (20.3 ± 9.0° vs. 33.4 ± 8.9°, p = 0.001).ConclusionQuadriceps muscle activation following passive stretching of the hamstrings appears to be superior to the PS and ND techniques in improving hamstring muscle flexibility.Clinical implicationsQuadriceps activation following passive hamstring stretching can be used in physiotherapy settings to improve hamstring muscle flexibility.

Preparation and properties of anion exchange membranes based on multiple quaternary ammonium groups

Anion exchange membrane fuel cell (AEMFC) has attracting great attention as one of the most clean energy conversion technologies, because it has a facile electrochemical kinetics under alkaline condition and enables the use of non-precious metal catalysts. The reported anion exchange membranes were usually prepared by tethering quaternary ammonium groups (QA) to the backbone of chloromethylated or bromomethylated aromatic polymers by immersing in trimethylamine solution. However, they exhibit much low ionic conductivity and poor alkaline stability, which hinders the further development of AEMFC technology. In order to improve the ionic conductivity of anion exchange membranes, we located multi QA groups on one side chains for enhancing the local density of ionic groups. Therefore, we synthesized a type of small molecule with a quaternary ammonium group and an alkyl bromide. After gethering it onto 1,4-diazabicyclo[2.2.2] octane-functionalized poly(arylene ether ketone) by a quaternization reaction, tri-quaternized poly(arylene ether ketone) (TQPAEK) was successfully prepared with flexible side chains containing multi quaternary ammonium groups. Then a series of anion exchange membranes in OH- form were obtained by solution casting and then alkaline treatment. The ionic exchange capacity of these membranes in the range of 1.75–2.57 meq/g could be adjusted by controlling the degree of bromination of the precursor polymer. The water uptake, swelling ratio and hydroxide conductivity of TQPAEK membranes increased with the increasing IEC values. They also showed good thermal and mechanical stabilities. Especially, the introduction of flexible side chains significantly improved the elongation at the break of membranes, which reached up to 103.2%. Meanwhile, the tensile stress was still higher than 28 MPa. AFM images showed that the hydrophilic/hydrophobic phase-separation morphology was formed in these TQPAEK containing multi-quaternized flexible side chains. Therefore, TQPAEK exhibited high ionic conductivity of 74.35 mS/cm at 80°C. The results indicated that TQPAEK membranes had the potential to be used in alkaline AEMFCs.

Densely quaternized anion exchange membranes synthesized from Ullmann coupling extension of ionic segments for vanadium redox flow batteries

Membranes with high ion conductivity and selectivity are important for vanadium redox flow batteries. Herein, densely quaternized anion exchange membranes based on quaternary ammonium functionalized octa-benzylmethyl-containing poly(fluorenyl ether ketone)s (QA-OMPFEKs) were prepared from the (i) condensation polymerization of a newly developed octa-benzylmethyl-containing bisphenol monomer via Ullmann coupling, (ii) bromination at the benzylmethyl sites using N-bromosuccinimide, and (iii) quaternization of the bromomethyl groups using trimethylamine. The QA-OMPFEK-20 with an ion exchange capacity (IEC) of 1.66 mmol g−1 exhibited a higher SO42− conductivity (9.62 mS cm−1) than that of the QA-TMPFEK-40 (4.82 mS cm−1) at room temperature, which had a slightly higher IEC of 1.73 mmol g−1 but much lower QA density. The enhanced SO42− conductivity of QA-OMPFEK-20 was attributed to the ion-segregated structure arising from the densely anchored QA groups, which was validated by SAXS observation. Furthermore, the QA-OMPFEK-20 showed much lower VO2+ permeability (1.24×10−14 m2 s−1) than QA-TMPFEK-40 (5.40×10−13 m2 s−1) and Nafion N212 (5.36×10−12 m2 s−1), leading to improved Coulombic and energy efficiencies in Vanadium redox flow batteries (VRFBs). Therefore, the Ullmann coupling extension is a valuable approach for the development of high performance anion exchange membranes for VRFBs.

Poly(arylene ether nitrile) anion exchange membranes with dense flexible ionic side chain for fuel cells

To resolve the excessive swelling and undesirable alkaline stability of densely functionalized type anion exchange membranes (AEMs) and to obtain high performance AEMs, quaternary ammonium-functionalized poly(arylene ether nitrile) (QPAEN) AEMs with dense flexible ionic side chain are prepared via nucleophilic substitution polycondensation, demethylation reaction and Williamson reaction. The densely pendent flexible long side chains with QA groups at the end provide a high conductivity and the introduced strong polar nitrile groups result in lower water uptake, excellent dimensional stability and strong alkali resistance of the AEMs. The QPAEN membrane with IEC of 1.78meqg−1 exhibits the highest hydroxide conductivity of 116.0 mScm−1 at 80°C. The high conductivity is attributed to the well-developed hydrophilic/hydrophobic phase separated morphology that constructs efficient ion conducting pathways in the membranes. High retention of hydroxide conductivity (80.2%) and ionic exchange capacity (IEC) (86.0%) was observed for the QPAEN-0.4 membrane in the degradation test in a 2M aqueous KOH solution for 480h. Moreover, the single cell performance of the as-prepared AEMs was greatly enhanced and a high peak power density of 251.3mWcm−2 at 60°C was observed.

A virtual dosimetry audit – Towards transferability of gamma index analysis between clinical trial QA groups

PurposeQuality assurance (QA) for clinical trials is important. Lack of compliance can affect trial outcome. Clinical trial QA groups have different methods of dose distribution verification and analysis, all with the ultimate aim of ensuring trial compliance. The aim of this study was to gain a better understanding of different processes to inform future dosimetry audit reciprocity. MaterialsSix clinical trial QA groups participated. Intensity modulated treatment plans were generated for three different cases. A range of 17 virtual ‘measurements’ were generated by introducing a variety of simulated perturbations (such as MLC position deviations, dose differences, gantry rotation errors, Gaussian noise) to three different treatment plan cases. Participants were blinded to the ‘measured’ data details. Each group analysed the datasets using their own gamma index (γ) technique and using standardised parameters for passing criteria, lower dose threshold, γ normalisation and global γ. ResultsFor the same virtual ‘measured’ datasets, different results were observed using local techniques. For the standardised γ, differences in the percentage of points passing with γ < 1 were also found, however these differences were less pronounced than for each clinical trial QA group’s analysis. These variations may be due to different software implementations of γ. ConclusionsThis virtual dosimetry audit has been an informative step in understanding differences in the verification of measured dose distributions between different clinical trial QA groups. This work lays the foundations for audit reciprocity between groups, particularly with more clinical trials being open to international recruitment.

Cationic Side-Chain Attachment to Poly(Phenylene Oxide) Backbones for Chemically Stable and Conductive Anion Exchange Membranes

A series of chemically stable and ionically conductive side-chain anion exchange membranes (AEMs) based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) backbones and alkyltrimethylammonium cations are reported in this work. Two alkyltrimethylammonium groups with n-propyl (C3) and n-pentyl (C5) alkyl chains were tethered onto PPO backbones through secondary amine moieties, resulting in two side-chain AEMs, that is, NC3Q-PPO and NC5Q-PPO and NC5 Q-PPO. In comparison to benzylic QA groups (e.g., benzyltrimethylammonium cations in quarternized PPO (QPPO) and benzylalkyldimethylammonium cations in comb-shaped PPOs (i.e., QC3-PPO and QC6-PPO)), the alkyltrimethylammonium cations of the side-chain PPOs, which do not possess highly reactive benzylic protons adjacent to both the aromatic ring and the cation, showed superior alkaline stability. After 30 days of aging in 1 mol/L NaOH solution at 80 °C, the retention of the conductivities of NC3Q-PPO (IEC = 2.17 mmol/g), NC5Q-PPO-40 (IEC = 2.03 mmol/g), and NC5Q-PPO-...

OC-0538: A virtual dosimetry audit – towards transferability between global QA groups in clinical trials

OC-0538: A virtual dosimetry audit – towards transferability between global QA groups in clinical trials

Adding access blood flow surveillance reduces thrombosis and improves arteriovenous fistula patency: a randomized controlled trial.

Stenosis is the main cause of arteriovenous fistula (AVF) failure. It is still unclear whether surveillance based on vascular access blood flow (QA) enhances AVF function and longevity. We conducted a three-year follow-up randomized, controlled, multicenter, open-label trial to compare QA-based surveillance and pre-emptive repair of subclinical stenosis with standard monitoring/surveillance techniques in prevalent mature AVFs. AVFs were randomized to either the control group (surveillance based on classic alarm criteria; n = 104) or to the QA group (QA measured quarterly using Doppler ultrasound [M-Turbo®] and ultrasound dilution [Transonic®] added to classic surveillance; n = 103).The criteria for intervention in the QA group were: 25% reduction in QA, QA<500 mL/min or significant stenosis with hemodynamic repercussion (peak systolic velocity [PSV] more than 400 cm/sc or PSV pre-stenosis/stenosis higher than 3). At the end of follow-up we observed a significant reduction in the thrombosis rate in the QA group (0.025 thrombosis/patient/year in the QA group vs. 0.086 thrombosis/patient/year in the control group [p = 0.007]). There was a significant improvement in the thrombosis-free patency rate (HR, 0.30; 95% CI, 0.11-0.82; p = 0.011) and in the secondary patency rate in the QA group (HR, 0.49; 95% CI, 0.26-0.93; p = 0.030), with no differences in the primary patency rate between the groups (HR, 0.98; 95% CI, 0.57-1.61; p = 0.935).There was greater need for a central venous catheter and more hospitalizations associated with vascular access in the control group (p = 0.034/p = 0.029).Total vascular access-related costs were higher in the control group (€227.194 vs. €133.807; p = 0.029). QA-based surveillance combining Doppler ultrasound and ultrasound dilution reduces the frequency of thrombosis, is cost effective, and improves thrombosis free and secondary patency in autologous AVF.