Select Group Research Articles

Direct benzylation of carboxylic acids using Pd@Cu2(BDC)2DABCO via C‐H (sp3) bond activation

In this study, Pd nanoparticles encapsulated in the copper‐based mesoporous metal–organic framework (Cu2(BDC)2DABCO) and used as a reusable heterogeneous catalyst to establish a method for the direct benzylation of carboxylic acids through C‐H (sp3) bond activation. The catalyst structure was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and inductively coupled plasma (ICP). This catalyst showed high catalytic activity, selectivity, and good functional group tolerance for the direct benzylation of carboxylic acids.

Relevance of Proteinuria in Kidney Transplant Recipients and Allograft Outcomes

BackgroundThe onset of proteinuria in renal allograft recipients is frequently associated with an increased risk for both graft failure and mortality. We investigated the risk associated with post-transplant proteinuria and its time-dynamics in a select group treated for biopsy proven antibody-mediated rejection (ABMR). MethodsEighty-five patients who underwent transplantation were enrolled in our study and followed up from transplantation until October 31, 2020, death, or the date of the return to dialysis. We created two main groups: the ABMR group (n = 19) and an ABMR-negative control group with stable kidney function (n = 52) without donor-specific antibodies (DSA) and a subgroup with DSAs but stable graft function (n = 14) without ABMR. Differences in patient, donor, and transplant graft characteristics between the groups were assessed by Fisher's exact test for categorical variables. Death-censored graft loss was evaluated with the help of Kaplan-Meier analysis using log risk statistics. ResultsProteinuria decreased after treatment in the ABMR group (P < .0009). Pre-treatment every 10 mg/mmol increase in proteinuria was associated with a 7% increase in the risk for graft failure in the ABMR group. The estimated 3-year graft survival was 87.5% in the ABMR group, compared to 93% in the group without ABMR but with pre-formed DSA, and 100% in the DSA negative subgroup (log-rank probe P < .0666). ConclusionProteinuria is an independent predictor for graft failure, can be lowered by treatment for ABMR but ABMR is associated with lower graft survival in our study population.

Prognostic Impact of Para-Aortic Lymph Node Metastasis in Resected Non-Pancreatic Periampullary Cancers

BackgroundSurgery remains debatable in para-aortic lymph node (PALN, station 16b1) metastasis in non-pancreatic periampullary cancer (NPPAC). This study examined the impact of PALN metastasis on outcomes following pancreaticoduodenectomy (PD) in NPPAC.MethodsA retrospective analysis of patients with NPPAC who were explored for PD with PALN dissection was performed. Based on the extent of nodal involvement on final histopathology, they were stratified as node-negative (N0), regional node involved (N+) and metastatic PALN (N16+) and their outcomes were compared.ResultsBetween 2011 and 2022, 153/887 PD patients underwent a PALN dissection, revealing N16+ in 42 patients (27.4%), of whom 32 patients underwent resection. The 3-years overall survival (OS) for patients with N16+ was 28% (95% confidence interval [CI] 13–60%), notably lower than the 67% (95% CI 53–83.5%; p = 0.007) for those without PALN metastasis. Stratified by nodal involvement, the median OS for N+ and N16+ patients was similar (28.4 months and 26.2 months, respectively). The N0 subgroup had a significantly longer 3-years OS of 87.5% (95% CI 79–96.7%; p = 0.0051). Interestingly, 10 patients not offered resection following N16+ identified on frozen section had a median survival of only 9 months. The perioperative morbidity and mortality in patients undergoing PD with PALN dissection were similar to standard resections.ConclusionIn a select group of patients with NPPAC, PD in isolated PALN metastasis was associated with improved OS. The survival in this group of patients was comparable with regional node-positive patients and significantly better than palliative treatment alone.

Aprotinin in high-risk isolated coronary artery bypass graft patients: a 3-year propensity matched study

BackgroundAprotinin, a serine protease inhibitor, has been used variably in cardiac surgery amidst ongoing debates about its safety following several previous studies. This study assesses the outcomes of aprotinin in high-risk isolated Coronary Artery Bypass Graft (iCABG) patients.MethodsThe study retrospectively analysed a cohort of 1026 iCABG patients, including 51 patients who underwent aprotinin treatment. Logistic regression powered score matching was employed to compare aprotinin patients with a control group, in a propensity-matched cohort of 96 patients. The primary outcome measured was in-hospital death, with secondary outcomes including renal dysfunction, stroke, myocardial infarction, re-exploration for bleeding or tamponade, and postoperative stay durations.ResultsThe aprotinin cohort had high-risk preoperative patients with significantly higher EUROSCORE II values, 7.5 (± 4.2), compared to 3.9 (± 2.5) in control group. However, aprotinin group showed no statistically significant increase (p-value: 0.44) in hospital mortality with OR 2.5 [95% CI 0.51, 12.3]. Major secondary outcome rates of renal replacement therapy and postoperative stroke compared to the control group were also statistically insignificant between the two groups.ConclusionThis study suggests that aprotinin may be safely used in a select group of high-risk iCABG patients. The reintroduction of aprotinin under specific conditions reflects its potential benefits in managing bleeding in high-risk surgeries, but also underscores the complexity of its risk-benefit profile in such critical care settings. Nonetheless, it highlights the importance of carefully selecting patients and conducting additional research, including larger and more controlled studies to fully comprehend the potential risks and benefits of aprotinin.

Biogeochemical Migration of Some Rare Elements in the “Leaf Debris–Soil” System of the Catenary Landscapes in Tropical Mountainous Forests in Southern Vietnam

Expeditionary studies of the functioning of landscapes of mid-mountain monsoon (including fog) forests have been being conducted within the landscape and ecological station in the territory of the Bidoup-Nui Ba National Park and the adjacent Hon Giao since 2018 and are currently underway. One of the research objectives is to clarify the biogeochemical migrations of the material composition of soils in the “leaf debris–soil” system. We have consistently studied natural objects for their material composition as well as the intensity and rate of involvement of chemical elements in physicochemical migration processes in the “leaf debris–soil” system. Our findings indicate an active influx of a select group of examined elements (Se, Pd, Ag, Cd, Sn, Bi), particularly Bi, Pd, Se, and Cd, through the leaf debris and the detachment of aboveground plant organs, warranting their integration into organogenic soil horizons. Subsequently, lateral migration (Pd, Cd, Se) ensues. Slope processes within subordinate landscape facets, in addition to soil moisture and aeration processes, contribute to the subsequent redistribution of elemental volumes introduced into organogenic soil horizons.

Selective Laser Trabeculoplasty Versus Medical Therapy for the Treatment of Open Angle Glaucoma or Ocular Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Selective laser trabeculoplasty (SLT) and medical therapy groups displayed comparable intraocular pressure (IOP) at most follow-ups. SLT was associated with significantly decreased rates of glaucoma surgeries, antiglaucomatous medications, and ocular adverse effects. To evaluate the efficacy and safety of SLT compared with medical therapy in the treatment of open angle glaucoma (OAG) or ocular hypertension (OHT). A systematic search was performed in PubMed, Embase, Cochrane Library and Web of Science databases. Randomized controlled trials (RCTs) comparing SLT with medical therapy were included. We computed mean differences (MDs) or standardized mean differences (STDs) for continuous endpoints and risk ratios (RRs) for binary endpoints, with 95% confidence intervals (CIs). Heterogeneity was assessed with I2 statistics. Software R, version 4.2.1, was used for statistical analyses. Subgroup analyses were performed on treatment-naive patients and on the class of drugs in the medical therapy group. Fourteen RCTs comprising 1706 patients were included, of whom 936 were submitted to SLT. Medical therapy was associated with a significantly improved IOP at 1 month and a higher proportion of patients achieving ≥20% IOP reduction. There were no significant differences between groups in IOP at 2, 3, 6, and 12 months, IOP fluctuation, rate of eyes at target IOP, visual field, and quality of life. The SLT group exhibited significantly decreased rates of glaucoma surgeries, antiglaucoma medications, and ocular adverse effects. SLT demonstrated comparable efficacy to medical therapy in IOP control at most follow-ups, along with favorable impacts on critical treatment-related factors. Our findings support SLT as a safe and effective treatment for OAG or OHT.

TIM-3 blockade enhances ex vivo stimulated allogeneic NK cell therapy for relapsed murine neuroblastoma after hematopoietic cell transplant.

High-risk neuroblastoma (HR-NBL) is an aggressive tumor of the sympathetic nervous system with high risk of relapse and poor overall survival. Allogeneic hematopoietic cell transplant (allo-HCT) has been used previously in HR-NBL patients; however, graft-versus-host-disease (GVHD) and disease progression have limited clinical application. Ex-vivo stimulated allogeneic natural killer (NK) cells represent a potential approach to enhance the graft-versus-tumor (GVT) effect without exacerbation of GVHD but have not shown efficacy in NBL. Ex-vivo stimulated NK cells from C57BL/6NCr (B6) mice were expanded with soluble IL-15/IL-15Rα alone or with irradiated CD137L/CD54+ AgN2a-4P (15-4P) at a 1:1 ratio for 10-12 days. Allogeneic NK cells were then analyzed for activation, proliferation, cytokine production, and cytotoxicity against two murine NBL cell lines, Neuro2a and NXS2, in the absence or presence of anti-TIM-3. Lethally irradiated B6AJF1 Mice received allo-HCT from B6 donors followed by NBL challenge after 7 days to mimic tumor relapse. Select groups received anti-TIM-3 starting on day 9 for every 4 days with/without infusions of 15-4P B6 NK cells on days 14, 21, and 28. In select experiments, T cell and NK cells were selectively depleted to establish their contribution to the GVT effect. All groups were analyzed for tumor growth, GVHD and overall survival. Co-culturing NK cells with 15-4P results in 78-fold expansion with increased expression of Ki-67 and NKG2D, NKp46, TRAIL and TIM-3. 15-4P stimulated allogeneic NK cells showed enhanced cytotoxicity against NBL compared to IL-15 NK cells alone but was limited in part due to high expression of TIM-3 ligands on Neuro-2a compared to NXS2. The addition of TIM-3 blockade further enhanced NK cytotoxicity versus Neuro-2a, with enhanced 15-4P NK cell degranulation, Eomes, TRAIL and FasL expression observed. Analysis of RNA from 15-4P NK cells exposed to TIM-3 blockade showed gene expression of chemokines, NKG2D/DAP12 signaling, non-canonical NF-κb pathway and TRAIL signaling. Blockade of NKG2D, TRAIL or FasL on 15-4P NK cells abrogated cytotoxicity. In vivo, the combination of 15-4P stimulated allogeneic NK cells and TIM-3 blockade after allo-HCT resulted in prolonged survival against NBL with decreased tumor burden compared to NK cells or anti-TIM-3 alone, without inducing GVHD. Depletion of NK cells, but not T cells, abrogated the GVT effect. Allo-HCT can be a platform for treating NBL using combination ex-vivo stimulated allogeneic NK cell therapy with TIM-3 blockade to enhance the GVT effect without inducing GVHD.

Two-element Selective Assembly with Non-linear Input-output Models Using Approximation

The process of single-parameter selective assembly of two elements is considered for the case of a nonlinear input-output modelapplication. Due to the objective complexity of determining the relations between the limit deviations and tolerances of input and output parameters, as well as the relative accuracy smallness due to the precision of the assembly, it is reasonable to represent the initial model in the form of a first-order polynomial of two variables. Linearisation is proposed to be carried out using a method of obtaining an approximating relation in the form of a Taylor series and by means of a multivariate least square method, with subsequent variantcomparison according to a given criterion. The criterion for choosing one of the two proposed variants is the minimum average approximation error. To determine the values of group tolerances, it is proposed to use two methods: assigning the equal tolerances and assigning tolerances of the equal relative accuracy. For both methods the derivation of the set-making equations is given, allowing the use of selective group numbersunder certain assumptions. Using a linearized model, the main indicators of the assembly process are determined: the number of assembly sets, work in progress and preliminary scrap. An example is given for the case when the output parameter represents the product of the input elementparameters. The coefficients were calculated and the set-making equation was derived. Comparison of the results presented in the paper with earlier obtained results (initial nonlinear model) shows a relatively small divergence in calculating the boundaries of selective groups, the error in determining the probability of obtaining assembly sets as a whole does not exceed 0.5%. The proposed method is applicable in case of small values of relative accuracy of input and output parameters, which in practice corresponds to selective assembly of precision products.

A Comprehensive Review on Hepatic Encephalopathy: Pathophysiology, Symptoms, Epidemiology, Classification, Diagnosis and Treatment

The condition known as hepatic encephalopathy (HE) is a state of impaired brain function that can be reversed and is experienced by patients who are suffering from severe liver diseases. Neurotoxins, decreased neurotransmission as a result of metabolic anomalies in liver failure, changes in brain energy metabolism, systemic inflammatory response, and alterations of the blood brain barrier are the primary hypotheses that are still being explored in relation to the precise pathophysiology of hepatic encephalopathy (HE). There is a wide spectrum of severity regarding the neurological and mental symptoms that can be brought on by HE. For the purpose of diagnosing limited HE, abnormal psychometric tests are utilised. Alterations in personality, altered states of consciousness, gradual spatial and temporal disorientation, lethargy, stupor, and coma are some of the characteristics of HE that are clinically noticeable. For the purpose of diagnosis, specific testing is not required outside of clinical studies. HE is classified according to the underlying disease, the severity of symptoms, the length of time it has been present, and whether or not there are triggers that cause it to occur. Hepatic encephalopathy refers to a collection of neuropsychiatric illnesses that can be treated and are characterised by the presence of symptoms in individuals who have liver disease or who have undergone portosystemic shunting. Entephalopathy, a disabling result of cirrhosis, affects thirty-five percent to forty-five percent of cirrhotic patients. Before recently, the treatment choices for HE that were available in hospitals were depending on anecdotal evidence, the availability of medication, and the norms of the relevant institutions. An increasing number of randomised controlled trials (RCTs) are providing further confirmation of the central significance of the basic HE therapy techniques (lactulose, branched-chain amino acids, and rifaximin), as well as the rising body of evidence showing the large beneficial advantages associated with these strategies. The liver transplantation and embolisation of large PSSs are two treatments that have proven to be effective for a select group of patients who have been carefully selected. Not only does it have a significant influence on the day-to-day lives of patients and carers, but it is also associated with increased rates of sickness and death and consumes a significant amount of resources in the healthcare system. In this article, we examine the history of hepatic encephalopathy, as well as the current understanding of the condition and the potential treatments for it.

An Institutional Shift from Routine to Selective Diversion of Low Anastomosis in Robotic TME Surgery for Rectal Cancer Patients Using the KHANS Technique: A Single-Centre Cohort Study.

(1) Background: In recent years, there has been a change in practice for diverting stomas in rectal cancer surgery, shifting from routine diverting stomas to a more selective approach. Studies suggest that the benefits of temporary ileostomies do not live up to their risks, such as high-output stomas, stoma dysfunction, and reoperation. (2) Methods: All rectal cancer patients treated with a robotic resection in a single tertiary colorectal centre in the UK from 2013 to 2021 were analysed. In 2015, our unit made a shift to a more selective approach to temporary diverting ileostomies. The cohort was divided into a routine diversion group treated before 2015 and a selective diversion group treated after 2015. Both groups were analysed and compared for short-term outcomes and morbidities. (3) Results: In group A, 63/70 patients (90%) had a diverting stoma compared to 98/135 patients (72.6%) in group B (p = 0.004). There were no significant differences between the groups in anastomotic leakages (11.8% vs. 17.8%, p = 0.312) or other complications (p = 0.117). There were also no significant differences in readmission (3.8% vs. 2.6%, p = 0.312) or reoperation (3.8% vs. 2.6%, p = 1.000) after stoma closure. After 1 year, 71.6% and 71.9% (p = 1.000) of patients were stoma-free. One major reason for the delay in stoma reversal was the COVID-19 pandemic, which only occurred in group B (0% vs. 22%, p = 0.054). (4) Conclusions: A more selective approach to diverting stomas for robotic rectal cancer patients does not lead to more complications or leaks and can be considered in the treatment of rectal cancer tumours.

Beyond the echo chamber: modelling open-mindedness in citizens’ assemblies

A Citizens’ assembly (CA) is a democratic innovation tool where a randomly selected group of citizens deliberate a topic over multiple rounds to generate, and then vote upon, policy recommendations. Despite growing popularity, little work exists on understanding how CA inputs, such as the expert selection process and the mixing method used for discussion groups, affect results. In this work, we model CA deliberation and opinion change as a multi-agent systems problem. We introduce and formalise a set of criteria for evaluating successful CAs using insight from previous CA trials and theoretical results. Although real-world trials meet these criteria, we show that finding a model that does so is non-trivial; through simulations and theoretical arguments, we show that established opinion change models fail at least one of these criteria. We therefore propose an augmented opinion change model with a latent ‘open-mindedness’ variable, which sufficiently captures people’s propensity to change opinion. We show that data from the CA of Scotland indicates a latent variable both exists and resembles the concept of open-mindedness in the literature. We calibrate parameters against real CA data, demonstrating our model’s ecological validity, before running simulations across a range of realistic global parameters, with each simulation satisfying our criteria. Specifically, simulations meet criteria regardless of expert selection, expert ordering, participant extremism, and sub-optimal participant grouping, which has ramifications for optimised algorithmic approaches in the computational CA space.

P-092 PGT-A Evaluates Advanced Sperm Selection in Embryos from High Teratozoospermia Males; a prospective randomized controlled trial

Abstract Study question Can sperm selection techniques improve the reproductive outcomes of ICSI patients, particularly in males with high teratozoospermia index (TZI) and sperm DNA fragmentation (SDF)? Summary answer Sperm selection techniques significantly increase fertilization and blastocyst development rates in males with high TZI and SDF, achieving a euploidy rate comparable to normal cases. What is known already Abnormal sperm morphology negative effects begin at the fertilization and reach the blastocyst quality and euploidy status. Men with abnormal teratozoospermic index (TZI) exhibit high levels of chromosomal abnormalities and sperm DNA fragmentation (SDF). SDF adversely affects pre and post-implantation embryo development events. Blastocyst aneuploidy isn’t solely due to the oocyte; but also, sperm contribution should be taken into consideration. Previous studies reported that advanced sperm selection techniques (PICSI and MACS) can efficiently enhance reproductive outcomes in abnormal SDF ICSI cases. The efficiency of these techniques in improving ICSI outcomes of patients with high TZI plus SDF remains unexplored. Study design, size, duration A prospective randomized controlled trial included a total of 264 couples, divided into three groups: (1) Control-1 group: males having normal TZI and no sperm selection techniques were used (n = 111), (2) Control-2 group (NO-SS): males having high TZI and no sperm selection techniques were used (n = 63), and (3) Sperm selection (SS) group: males having high TZI and SDF, and sperm selection techniques were used (n = 90). The study started from January till October 2023. Participants/materials, setting, methods Eligibility: females had ≥5MII oocytes, males had abnormal (&amp;gt;1.8) TZI, and all blastocysts (≥4BB) had trophoectoderm biopsy. Cases were randomized on the ICSI day to (control-2) and (SS) groups, along with (control-1) with normal TZI for comparison. Females were categorized into 2 subgroups (&amp;lt;35, and ≥35 years). SS techniques included physiological ICSI and magnetic-activated cell sorting. PGT-A was done using Illumina platform (Miseq). Statistical analysis (SPSS) of pre-implantation embryo development and PGT-A results was done. Main results and the role of chance We found no significant differences between the female, male ages and number of mature oocytes between the studied groups. Limitations, reasons for caution The results included all pre-implantation embryo parameters but, subsequent post-implantation events like implantation, pregnancy, and miscarriage rates will add more data about the competency of the resulting embryos. A Small sample size of females aged from 36 to 40 years old. Wider implications of the findings Sperm selection techniques appear to be efficient in improving fertilization, blastocyst development rates, and euploidy rates in males with high TZI and sperm DNA fragmentation, suggesting potential benefits for couples undergoing infertility treatment. Trial registration number NCT06231589

Opioid-Free Anesthesia with a Mixture of Dexmedetomidine, Ketamine and Lidocaine in Severely Obese Patients Undergoing Laparoscopic Cholecystectomy

Abstract Background Opioids have historically been a first-line therapy for surgical pain control. They were considered optimum and the mainstay for balanced anesthesia but recently the concerns about their side effects were raised. The concept of opioid free anesthesia (OFA) was introduced to provide a safer alternative that would provide benefits to selective group of patients as well as enhance recovery after surgery. Methods The current study compares the use of a mixture of dexmedetomidine and ketamine infusion with traditional fentanyl infusion intra-operative on many variables both intra-operative and post- operative in laparoscopic surgeries. Number of patients who will need rescue narcotics after extubation and total nalbuphine consumption, hemodynamic events (bradycardia, hypotension and hypertension), time to extubation, time to reach Alderete score of 9, post-operative hypoxemia, vomiting, pain scores were recorded and compared with the traditional balanced anesthesia (TBA). Results Forty patients were enrolled in the study, 20 patients in each group. The 2 groups, TBA and OFA, were comparable in demographic data (age, sex, body mass index (BMI), lean body weight (LBW)) and duration of surgery. There was significant decrease in pain scores, number of patients who will need rescue narcotics after extubation and nalbuphine consumption in the OFA group that extended to 24 h post-operative. TBA group showed statistically significant less time needed for extubation (P-value 0.018) and reaching Aldrete score of 9 (P-value 0.02). Conclusions OFA has a better profile than TBA as regard to post-operative pain score and opioid consumption post-operative but they have relative increase in time to extubation and time to reach Aldrete score of 9, and they were equally safe regarding post operative hypoxia and hemodynamics.

Group consensus under asymmetric voting behavior

Abstract In this study, we propose a group formation model by assuming voters hold asymmetric irrationality, namely the probability of accepting a candidate with whom they disagree with. Moreover, we utilize a non-Markovian function by introducing a rationality decay rate to represent that agents’ rationality decays as their contributed admissions on the candidate increase. We have systematically explored the impact of non-Markovian asymmetric irrationality, voter selection mechanisms, voter number, and group size on the degree of consensus. Our findings indicate that, with only one voter, as the group size increases, the degree of consensus converges to a value determined by the irrationality ratio. Remarkably, even in scenarios with significant asymmetry in irrationality, a substantial degree of consensus can still be maintained. Furthermore, for multiple voters, the relationship between the degree of group consensus and rationality decay rate exhibits non-monotonic behaviors. In summary, this research offers new theoretical insights into group dynamics and provides implications for enhancing consensus in real-world social groups.

Is parity pricing enough? A critical analysis of parity pricing and the case for additional strategies

Producers in the U.S., particularly small-scale farmers and specialty crop growers, are unable to maintain their livelihoods with farming alone. This issue is convoluted by low farm gate prices stemming from the unequal distribution of market share and political support within the U.S. food supply chain. As a result, many farm activists and scholars have recommended a revitalization of parity pricing within U.S. policy. Parity pricing once served to set price floors considered to represent “fair” farm gate prices determined by the farm gate price and purchasing power of commodities during the parity period of 1910–1914. In this paper, we evaluate whether parity did exist during the set period of 1910–1914, showing farm incomes and non-farm incomes were not significantly different from one another during the parity period. We then explore the extent to which parity prices correspond to farm-gate prices, transfer terminal prices, and retail prices for a select group of twelve specialty crops. We show that farm gate prices are significantly lower than parity prices, do not necessarily translate into low prices for consumers, and do not consistently correlate with production costs. Lastly, we display the temporal correspondence between the end of parity pricing and declines in farm income. Our analysis contributes important evidence of the inequalities within production, payment, and pricing structures of specialty crops in the U.S. As such, we provide a critique of parity pricing arguing that parity pricing alone will not be sufficient to solve the complex and deeply rooted issues underpinning low farm gate prices and injustices within the U.S. food system. We conclude with a discussion of the impacts of low farm gate prices and areas for policy interventions.

Existing and Evolving Therapies for Arteriovenous Fistula and Graft Dysfunction

A functional vascular access (VA) is of paramount importance to patients on hemodialysis therapy. While arteriovenous fistula (AVF) remains the preferred VA, their long-term patency is unpredictable. A dysfunctional VA contributes to a high morbidity rate, an increased susceptibility to major adverse cardiovascular events, recurrent hospitalization, and a poor quality of life. The recent innovations in devices and technologies have significantly expanded our options to create and prolong VA patency. Endovascular devices such as WavelinQ and Ellipsys are recent additions to creating a VA. The endovascular creation of AVF helps reduce the wait time and potentially avoids or reduces the duration of catheter use. The bioengineered graft and immediate access arteriovenous graft offer reasonable alternatives in a select group of patients. There is growing evidence that covered stents and drug-coated balloons offer options to prolong the VA patency. Finally, the role of stem cell therapy in VA is currently being explored. This article presents a comprehensive review of the conventional and current developments in the management of a dysfunctional VA.

REVISITING THE FIVE-POWERS WAR RISK EXCLUSION

AbstractMarine war risk insurance fundamentally contemplates casualties caused by international conflict. Curiously, however, standard clauses also exclude cover and automatically terminate war risk policies in the event of an outbreak of war between a select group of historically powerful States: China, France, the United Kingdom, the United States and Russia. This article aims to demystify the origins of this five-powers clause and evaluate its prospective application through the lens of an emerging breed of confrontation among the world's major powers.

Evaluating Numerical Methods to Investigate Spectral Solar Radiative Transfer in Plant Canopies

AbstractThe disposition of spectral solar irradiance in plant canopies is crucially important to understand processes such as photolysis of molecules amenable to absorbing actinic light. Thus, one objective of this study is to evaluate the most commonly applied radiative transfer approaches to estimate spectral irradiance as a function of plant canopy depth. Eight radiative transfer approaches are ascertained. Another objective is to determine the impacts of the spectral resolution assumed in radiative transfer calculations and model choice on key processes such as canopy absorption and reflection of irradiance. By comparing results from broadband‐only and spectrally‐resolved canopy radiative transfer, we aim to quantitatively determine the uncertainties associated with failing to resolve the sunlight spectra. We determine the optimal spectral resolution required to estimate canopy radiative transfer results such as air‐chemistry‐specific quantities related to photolysis of a select group of molecules. In addition, we evaluate techniques for binning leaf and soil optical properties. Results showed that high spectral resolution is ideally desired to compute photolysis of molecules such as ozone, nitrogen dioxide, nitrate radical, nitrous acid, and formaldehyde. For in‐canopy photolysis of molecules, a waveband resolution of at least 10 nm is sufficient to obtain accurate estimates for most photochemical reactions. Positive reaction‐dependent uncertainties in canopy‐mean relative photolysis values for individual molecules can be as high as 30% compared to estimates derived with broad‐band solar irradiance.

Molecularly imprinted polymer based on MIL-101 (Cr) MOF incorporated polyvinylidene for selective adsorption and separation dye with improved antifouling properties

In this work, new membrane was fabricated from polyester fabric (PF) as a substrate which was coated by a casting solution containing polyvinylidene fluoride (PVDF) blending by addition of MIL-101 (Cr) metal-organic framework (MOF)-molecularly imprinted 3-aminophenolhexamethylenetetramine (MIAPH) as filler and sodium dodecyl sulfate (SDS) as hydrophilic agent. The membrane was fabricated by phase inversion method (PVDF/MIAPH). The MIAPH has selective functional groups and was applied as filler in the mixed matrix membrane. The as-prepared MIAPH was characterized by FE-SEM, EDS, XRD, FTIR and BET-BJH analyses. The hydrophilic property, dye adsorption and filtration properties of the MIAPH/PVDF/PF membrane were studied for removal Trypan blue (TB) based on central composite design (CCD) technique through investigating operational variables (pH, TB concentration, pressure). In the fabrication of membranes, the optimal filtration properties appear at the 30 μL of SDS solution and 0.005 g MIAPH fillers. The fabricated MIAPH/PVDF/PF membrane indicates a high removal efficiency up to 94.9 % for the TB removal and has high selectivity. The data of the adsorption equilibrium were described by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms. The findings illustrated that appropriate of MIAPH in membranes could be an efficient and selective technique for TB elimination.

How can digital media enhance students' mastery of threshold concepts?

Mastery of threshold concepts is driven by students’ expanding knowledge and experience. Threshold concepts cannot be taught via the simple transfer of knowledge, but instead ‘emerge’ for students via experience, conceptualisation and self-development (Meyer and Land, 2005). This can happen at different stages via different means and students may enter a liminal state whereby they oscillate between states of understanding and being (Cousin, 2006; Meyer and Land 2005). Teaching and re-teaching threshold concepts at set points adds to the teaching load and may not be an effective way to support students’ mastery on what is a messy, unpredictable and personal journey. The persistence of learning resources in the online space means that students can drive their own learning and development by visiting and revisiting interactive digital resources that demonstrate conceptually difficult or contradictory knowledge. Such troublesome knowledge is a feature of many fields of engineering. The transformative power of digital media can take students outside of the classroom and immerse them in other worlds. By taking a focussed approach in this project, we will explore what transformative and troublesome knowledge means in the literature, and to a select group of students and staff at WMG. Using the findings, we will then propose digital media solutions informed by multiple perspectives.