bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the performance of solar water heater: an experimental and theoretical investigation
Authors: Alwan Naseer T , Majeed Milia H , Khudhur Ihsan M , Shcheklein S E , Ali Obed M , Yaqoob Salam J , Alayi Reza
Published: April 2022

This study aims to evaluate the performance of a flat plate solar water heater (SWH) theoretically and experimentally. The thermal performance of the SWH was predicted using Fortran 90 programming language. SWH was designed as a square shape with dimensions of 110 cm length, 120 cm width and 10 cm depth and tested by integrating with a modified solar distiller to increase the water temperature in the basin at a constant mass flow rate of 1.2 l/min. The tests were conducted under the weather condition of Yekaterinburg city, Russia, from June to September of 2019, and a typical day was chosen for each month (19 June, 17 July, 22 August and 15 September). The study revealed that the highest efficiency of the solar water collector obtained at the highest value of the intensity of solar radiation at mid-day. The maximum thermal efficiencies achieved on 17 July of 2019 were ~67% and 66% based on theoretical and experimental analyses, respectively. A simultaneous increase in the water temperature and the intensity of solar radiation has been observed. During the four typical days of the experiment, the highest water temperatures of the solar collector were recorded during midday, i.e. $57.2{}^{\circ}\mathrm{C},64.4{}^{\circ}\mathrm{C},52.4{}^{\circ}\mathrm{C}\kern0.5em \mathrm{and}\ 49{}^{\circ}\mathrm{C}$ at the inlet, and $62.8{}^{\circ}\mathrm{C},71{}^{\circ}\mathrm{C},57.4{}^{\circ}\mathrm{C}$ and $53.2{}^{\circ}\mathrm{C}$ at the outlet for 19 June, 17 July, 22 August and 15 September 2019, respectively, while the solar radiation intensities recorded are $957,1022,840\kern0.5em \mathrm{and}\ 723\ \mathrm{W}/{\mathrm{m}}^2$ for the test days.
Novel method for microencapsulation of eutectic hydrated salt as a phase change material for thermal energy storage
Authors: Huo Xianliang , Xie Donghuan , Zhao Zimo , Wang Shujun , Meng Fanbin
Published: April 2022

Inorganic hydrated salts have many advantages over organic phase change materials (PCMs), such as higher thermal storage density, low cost, non-toxicity and non-flammability. In this research, microcapsules loaded with eutectic hydrated salt (EHS) as the core material was fabricated via coacervation method at room temperature, with ethyl cellulose/acrylonitrile butadiene styrene as the shell material. EHS consisted of sodium sulfate decahydrate and disodium hydrogen phosphate dodecahydrate with a mass ratio of 1:3 was prepared as the PCM with its phase change temperature of 29.3°C and phase change enthalpy of 218.58 J/g. The chemical structures and morphology were investigated by Fourier transform infrared spectroscopy and scanning electron microscope. Results indicates that the almost spherical microcapsules, with diameter around 60 μm, are of core–shell microstructures and good chemical compatibility of the core and shell material. Differential scanning calorimetry results shows that microcapsules possess a high latent heat (178.36 J/g) and excellent thermal stability and reliability, which are suitable for thermal energy storage and management in practical applications. More importantly, the simple and environmentally conscious way of this study may be extended to other promising inorganics@organics PCMs with different core–shell structured compositions.
An integrated CCU-plant scheme and assessment for conversion of captured CO2 into methanol
Authors: Yang Ning , Kang Fu , Liu Zhenyu , Ge Xinzhe , Zhou Yunlong
Published: April 2022

The purpose of this work is to highlight the interest of CO2 conversion into MeOH through a complete assessment of the entire CO2-to-MeOH chain. A CO2 capture unit using MEA solvent is considered to treat the CO2 from a 600-MW power plant, and the captured CO2 is then sent to the CO2 conversion unit. As a result, the combination of the two units leads to the integrated CO2 capture and utilization (CCU) plant, in particular involving the reuse of the heat from the high-temperature flows of the exothermal CO2 conversion reactions for regeneration of the CO2 capture solvent, and the recovered H2O between the CO2 capture and conversion units is also proposed to completely fulfill the H2O make-up. The technological results suggest that the integrated CCU plant is expected to offer advantages. The integrated CCU plant studied can utilize ~17.3% of the CO2 emissions of a power plant and convert 92% of them to 59.96 t of MeOH, and the heat integration corresponds to a 41.84% reduction in total reboiler load for the regeneration of MEA solvent. An economic assessment is proposed to estimate the OPEX and CAPEX costs, as well as the net present value, which confirms that the feasible economic conditions strongly depends on electricity costs. The contribution of the process or flows from CCU plant to the main environmental impacts is finally determined using the LCA method. The integrations inside the CCU plant offer a significant reduction in impact categories and CO2 emission as well as non-CO2 emission impacts when compared to the conventional MeOH production process.
Ecopump: a novel thermoelectric heat pump/heat recovery ventilator system for domestic building applications
Authors: Xu Qi , Zhang Shihao , Riffat Saffa
Published: April 2022

In recent years, there has been a risen interest in heat recovery systems for building applications due to concerns about the energy crisis and global climate change. In this paper, the intention to understand the performance of a window thermoelectric heat pump/heat recovery system (Ecopump) for heating has been developed. An overview to the prototype design, heat transfer model, experimental parameters and environmental feasibility is discussed. The variation of MATLAB modelling results followed the same regularity as the experimental results. The MATLAB model along with Revit has been used to simulate the Ecopump’s performance when installed in a sustainable house in the UK. From the calculation, Ecopump can provide 670 kWh heating energy and reduce 90.6 kg CO2 emissions per year. The proposed Ecopump system combined with window frame could be a promising technology to enhance space heating for domestic buildings while reducing energy consumption during daily ventilation. Further in situ experiments should be conducted to explore its comprehensive performance in the future.
What might COVID-19 patients experience after recovery? A comprehensive review
Authors: Elhiny Rehab , Al-Jumaili Ali Azeez , Yawuz Mohammed Jamal
Published: April 2022

Objectives

The objective of this review was to describe the COVID-19 complications after recovery.

Methods

The researchers systematically reviewed studies that reported post-COVID-19 complications from three databases: PubMed, Google Scholar and the World Health Organization (WHO) COVID-19 database. The search was conducted between 21 November 2020 and 14 January 2021. Inclusion criteria were articles written in English, with primary data, reporting complications of COVID-19 after full recovery. The review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement.

Key findings

This review included 69 studies with 146 725 patients from 22 countries related to post-COVID-19 complications. Thirty-six studies reported post-cure respiratory complications, ranging from dyspnoea to residual pulmonary fibrosis. Cardiac symptoms were reported in nine studies, including palpitation, chest pain and diastolic dysfunction. Neurological complications included post-traumatic stress syndrome, anxiety, depression, memory issues, insomnia and sleeping disturbance, cognitive impairments and stigma. Gastrointestinal symptoms included nausea, vomiting, diarrhoea and acute liver injury. The physical decline was the most common symptom reported in the musculoskeletal complications.

Conclusion

COVID-19 may cause several types of complications after recovery (testing negative PCR). The identified complications include respiratory, neurological/mental, cardiovascular, gastrointestinal tract, urinary tract, musculoskeletal and miscellaneous complications. However, the key impairments were pulmonary consequences, psychological problems and exercise intolerance. Thus, COVID-19 patients may need long-term follow-up.
Zero-order hold discretization of general state space systems with input delay
Authors: Pechlivanidou Georgia , Karampetakis Nicholas
Published: April 2022

Plethora of applications in physics and engineering are dealing with systems that are subject to input delays. Despite the scientific focus, previous research investigated only state space systems with input delays. Here, we investigate the discretization of generalized state space system with input delay by using the zero-order hold method. Firstly, the solution of a continuous time, generalized state space system with input delay is addressed. By applying the appropriate zero-order hold sampling method, we transform a continuous time linear system into the equivalent discrete time system, while the discrete time solution of the equivalent system is analytically presented. Finally, we use local error metric to estimate the difference between the continuous time and discrete time solutions.
Log-Canonical Coordinates for Symplectic Groupoid and Cluster Algebras
Authors: Chekhov Leonid O , Shapiro Michael
Published: April 2022

Using Fock–Goncharov higher Teichmüller space variables we derive log-canonical coordinate representation for entries of general symplectic leaves of the $\mathcal A_n$ groupoid of upper-triangular matrices and, in a more general setting, of higher-dimensional symplectic leaves for algebras governed by the reflection equation with the trigonometric $R$-matrix. The obtained results are in a perfect agreement with the previously obtained Poisson and quantum representations of groupoid variables for $\mathcal A_3$ and $\mathcal A_4$ in terms of geodesic functions for Riemann surfaces with holes. We realize braid-group transformations for $\mathcal A_n$ via sequences of cluster mutations in the special $\mathcal A_n$-quiver. We prove the groupoid relations for normalized quantum transport matrices and, as a byproduct, obtain the Goldman bracket in the semiclassical limit. We prove the quantum algebraic relations of transport matrices for arbitrary (cyclic or acyclic) directed planar network.Dedicated to the memory of a great mathematician and person, Boris Dubrovin.
Combinatorial Invariance Conjecture for $\widetilde {A}_2$
Authors: Burrull Gaston , Libedinsky Nicolas , Plaza David
Published: April 2022

The combinatorial invariance conjecture (due independently to Lusztig and Dyer) predicts that if $[x,y]$ and $[x^{\prime},y^{\prime}]$ are isomorphic Bruhat posets (of possibly different Coxeter systems), then the corresponding Kazhdan–Lusztig polynomials are equal, that is, $P_{x,y}(q)=P_{x^{\prime},y^{\prime}}(q)$. We prove this conjecture for the affine Weyl group of type $\widetilde {A}_2$. This is the first infinite group with non-trivial Kazhdan–Lusztig polynomials where the conjecture is proved.
Positive Mass Theorem With Arbitrary Ends and Its Application
Authors: Zhu Jintian
Published: April 2022

In this article, we give a proof for positive mass theorem (PMT) of asymptotically flat manifolds with arbitrary ends when the dimension is no greater than seven. As an application, we also show a PMT for asymptotically locally Euclidean manifolds with necessary incompressible conditions.
Respiratory Syncytial Virus Is the Leading Cause of United States Infant Hospitalizations, 2009–2019: A Study of the National (Nationwide) Inpatient Sample
Authors: Suh Mina , Movva Naimisha , Jiang Xiaohui , Bylsma Lauren C , Reichert Heidi , Fryzek Jon P , Nelson Christopher B
Published: April 2022

Background

This study describes leading causes of hospitalization, including respiratory syncytial virus (RSV), in United States infants (<1 year) from 2009 through 2019.

Methods

Within the National (Nationwide) Inpatient Sample (NIS) data, hospitalizations were determined by primary diagnosis using International Classification of Diseases, Ninth or Tenth Revision codes. RSV was defined as 079.6, 466.11, 480.1, B97.4, J12.1, J20.5, or J21.0. Bronchiolitis was defined as 466.19, J21.8, or J21.9. Leading causes overall and by sociodemographic variables were identified. The Kids’ Inpatient Database (KID) was used for confirmatory analyses.

Results

Acute bronchiolitis due to RSV (code 466.11 or J21.0) was the leading primary diagnosis, accounting for 9.6% (95% confidence interval [CI], 9.4%–9.9%) and 9.3% (95% CI, 9.0%–9.6%) of total infant hospitalizations from January 2009 through September 2015 and October 2015 through December 2019, respectively; it was the leading primary diagnosis in every year accounting for >10% of total infant hospitalizations from December through March, reaching >15% in January–February. From 2009 through 2011, acute bronchiolitis due to RSV was the leading primary diagnosis in every birth month. Acute bronchiolitis due to RSV was the leading cause among all races/ethnicities, except Asian/Pacific Islanders, and all insurance payer groups. KID analyses confirmed these results.

Conclusions

Acute bronchiolitis due to RSV is the leading cause of US infant hospitalizations.
Male Circumcision and Genital Human Papillomavirus (HPV) Infection in Males and Their Female Sexual Partners: Findings From the HPV Infection and Transmission Among Couples Through Heterosexual Activity (HITCH) Cohort Study
Authors: Shapiro Samantha B , Wissing Michel D , Khosrow-Khavar Farzin , El-Zein Mariam , Burchell Ann N , Tellier Pierre Paul , Coutlée François , Franco Eduardo L
Published: April 2022

Background

Previous studies examining the association between male circumcision (MC) and human papillomavirus (HPV) infections have reported inconsistent results. We used data from the HPV Infection and Transmission Among Couples Through Heterosexual Activity (HITCH) cohort study to examine the association between MC and HPV infections in males and their female sexual partners.

Methods

We enrolled monogamous couples in a longitudinal study between 2005 and 2011 in Montreal, Canada. We used logistic and Poisson regression models with propensity score adjustment to estimate odds ratios (ORs) and rate ratios for the association between MC and the prevalence, transmission, and clearance of HPV infections.

Results

Four hundred thirteen couples were included in our study. The prevalence OR for the association between MC and baseline infections was 0.81 (95% confidence interval [CI], .56–1.16) in males and 1.05 (95% CI, .75–1.46) in females. The incidence rate ratio for infection transmission was 0.59 (95% CI, .16–2.20) for male-to-female transmission and 0.77 (95% CI, .37–1.60) for female-to-male transmission. The clearance rate ratio for clearance of infections was 0.81 (95% CI, .52–1.24).

Conclusions

We found little evidence of an association between MC and HPV infection prevalence, transmission, or clearance in males and females. Further longitudinal couple-based studies are required to investigate this association.
A conserved cellular mechanism for cotton fibre diameter and length control
Authors: Yanagisawa Makato , Keynia Sedighe , Belteton Samuel , Turner Joseph A , Szymanski Daniel
Published: April 2022

Highly polarized cotton fibre cells that develop from the seed coat surface are the foundation of a multi-billion-dollar international textile industry. The unicellular trichoblast emerges as a hemispherical bulge that is efficiently converted to a narrower and elongated shape that extends for about 2 weeks before transitioning into a cellulose-generating machine. The polarized elongation phase employs an evolutionarily conserved microtubule-cellulose synthase control module that patterns the cell wall and enables highly anisotropic diffuse growth. As the multi-scale interactions and feedback controls among cytoskeletal systems, morphologically potent cell wall properties, and a changing cell geometry are uncovered, opportunities emerge to engineer architectural traits. However, in cotton, such efforts are hampered by insufficient knowledge about the underlying control mechanisms. For example, fibre diameter is an important trait that is determined during the earliest stages of development, but the basic growth mode and the mechanisms by which cytoskeletal and cell wall systems mediate fibre tapering are not known. This paper combines multiparametric and multiscale fibre phenotyping and finite element computational modelling of a growing cell to discover an evolutionarily conserved tapering mechanism. The actin network interconverts between two distinct longitudinal organizations that broadly distributes organelles and likely enables matrix secretion patterns that maintain cell wall thickness during growth. Based on plausible finite element models and quantitative analyses of the microtubule cytoskeleton, tapering and anisotropic growth is programmed by a constricting apical microtubule depletion zone and highly aligned microtubules along the fibre shaft. The finite element model points to a central role for tensile forces in the cell wall to dictate the densities and orientations of morphologically potent microtubules that pattern the cell wall.
Risk factors for acute diarrhoea in children between 0 and 23 months of age in a peri-urban district of Pakistan: a matched case–control study
Authors: Sadiq Kamran , Mir Fatima , Jiwani Uswa , Chanar Suhail , Nathwani Apsara , Jawwad Muhammad , Hussain Amjad , Rizvi Arjumand , Muhammad Shah , Habib Muhammad Atif , Soofi Sajid Bashir , Ariff Shabina , Bhutta Zulfiqar A
Published: April 2022

Background

Diarrhoea is a leading cause of preventable childhood morbidity and mortality worldwide. Unfortunately, Pakistan has the third-highest burden of diarrhoea-related deaths in children <5 y of age. Therefore we aimed to evaluate factors associated with diarrhoea among Pakistani children.

Methods

A retrospective 1:2 matched case–control study nested in a baseline cross-sectional survey was conducted from October to December 2018 in Taluka Kotri, a two-thirds urban locality in the Jamshoro district. Children between the ages of 0 and 23 months with a history of diarrhoea in the 2 weeks preceding the survey were labelled as cases. Age-matched controls were children without symptoms of diarrhoea. Univariate and multivariable conditional logistic regression was performed to identify diarrhoea-related factors.

Results

A total of 1558 cases were matched with 3116 controls. Factors significantly associated with lower odds of diarrhoea in the multivariate analysis included increasing maternal age (odds ratio [OR] 0.78 [95% confidence interval {CI} 0.67 to 0.90]), breastfeeding (OR 0.77 [95% CI 0.66 to 0.90]), higher paternal education (OR 0.79 [95% CI 0.65 to 0.97]) and belonging to the rich (OR 0.66 [95% CI 0.54 to 0.80]) and richest quintiles (OR 0.54 [95% CI 0.44 to 0.66]).

Conclusions

This study identifies risk factors associated with diarrhoea in children <23 months of age, including younger maternal age, higher paternal education, not breastfeeding and poverty, which has implications for developing preventive programs and strategies that target populations with a higher risk of diarrhoea.
Rebooting effective clinical supervision practices to support healthcare workers through and following the COVID-19 pandemic
Authors: Martin Priya , Kumar Saravana , Tian Esther , Argus Geoff , Kondalsamy-Chennakesavan Srinivas , Lizarondo Lucylynn , Gurney Tiana , Snowdon David
Published: April 2022

The importance of clinical supervision, a professional support and clinical governance mechanism, to patients, healthcare workers and organizations has been well documented. Clinical supervision has been shown to support healthcare workers during challenging times, by reducing burnout, enhancing mental health and wellbeing at work, and improving job satisfaction. However, clinical supervision participation and effectiveness are pre-requisites for realising these benefits. During times of stress and increased workloads (e.g. during the Coronavirus pandemic), healthcare workers tend to prioritise clinical duties and responsibilities over clinical supervision. Effective supervision practices can be restored, and healthcare workers can be better supported in their roles during and in the post-pandemic period only if healthcare workers, policy makers, healthcare organizations, clinical supervision trainers and researchers join forces. This paper sheds light on this important topic and offers a number of practical recommendations to reboot effective clinical supervision practices at the point of care.
Penicillin G concentrations required for prophylaxis against Group A Streptococcus infection evaluated using a hollow fibre model and mathematical modelling
Authors: Tait Jessica R , Barnett Timothy C , Rogers Kate E , Lee Wee Leng , Page-Sharp Madhu , Manning Laurens , Boyd Ben J , Carapetis Jonathan R , Nation Roger L , Landersdorfer Cornelia B
Published: April 2022

Background

Acute rheumatic fever (ARF), an autoimmune reaction to Group A Streptococcus (Streptococcus pyogenes; Strep A) infection, can cause rheumatic heart disease (RHD). New formulations of long-acting penicillins are being developed for secondary prophylaxis of ARF and RHD.

Objectives

To evaluate the penicillin G concentrations required to suppress growth of Strep A.

Methods

Broth microdilution MIC and MBC for Strep A strains M75611024, M1T15448 and M18MGAS8232 were determined. All strains were studied in a hollow fibre model (initial inoculum 4 log10 cfu/mL). Constant penicillin G concentrations of 0.008, 0.016 and 0.05 mg/L were examined against all strains, plus 0.012 mg/L against M18MGAS8232. Viable counts were determined over 144 h. Subsequently, all penicillin G-treated cartridges were emptied, reinoculated with 5 log10 cfu/mL and counts determined over a further 144 h. Mathematical modelling was performed.

Results

MIC and MBC were 0.008 mg/L for all strains; small subpopulations of M75611024 and M1T15448, but not M18MGAS8232, grew at 1× MIC. Following the first inoculation, 0.008 mg/L achieved limited killing and/or stasis against M75611024 and M1T15448, with subsequent growth to ∼6 log10 cfu/mL. Following both inocula, concentrations ≥0.016 mg/L suppressed M75611024 and M1T15448 to <1 log10 cfu/mL from 6 h onwards with eradication. Concentrations ≥0.008 mg/L suppressed M18MGAS8232 to <1 log10 cfu/mL from 24 h onwards with eradication after both inoculations. Mathematical modelling well described all strains using a single set of parameter estimates, except for different maximum bacterial concentrations and proportions of bacteria growing at 1× MIC.

Conclusions

In the absence of validated animal and human challenge models, the study provides guidance on penicillin G target concentrations for development of new penicillin formulations.
Frequency of azole resistance in clinical and environmental strains of Aspergillus fumigatus in Turkey: a multicentre study
Authors: Ener Beyza , Ergin Çağrı , Gülmez Dolunay , Ağca Harun , Tikveşli Melek , Aksoy Seçil Ak , Otkun Müşerref , Siğ Ali Korhan , Öğünç Dilara , Özhak Betil , Topaç Tuncay , Özdemir Aslı , Metin Dilek Yeşim , Polat Süleyha Hilmioğlu , Öz Yasemin , Koç Nedret , Atalay Mustafa Altay , Erturan Zayre , Birinci Asuman , Çerikçioğlu Nilgün , Timur Demet , Ekşi Fahriye , Genç Gonca Erköse , Findik Duygu , Gürcan Şaban , Kalkanci Ayşe , Arikan-Akdagli Sevtap
Published: April 2022

Objectives

Aspergillus fumigatus causes several diseases in humans and azole resistance in A. fumigatus strains is an important issue. The aim of this multicentre epidemiological study was to investigate the prevalence of azole resistance in clinical and environmental A. fumigatus isolates in Turkey.

Methods

Twenty-one centres participated in this study from 1 May 2018 to 1 October 2019. One participant from each centre was asked to collect environmental and clinical A. fumigatus isolates. Azole resistance was screened for using EUCAST agar screening methodology (EUCAST E.DEF 10.1) and was confirmed by the EUCAST E.DEF 9.3 reference microdilution method. Isolates with a phenotypic resistance pattern were sequenced for the cyp51A gene and microsatellite genotyping was used to determine the genetic relationships between the resistant strains.

Results

In total, resistance was found in 1.3% of the strains that were isolated from environmental samples and 3.3% of the strains that were isolated from clinical samples. Mutations in the cyp51A gene were detected in 9 (47.4%) of the 19 azole-resistant isolates, all of which were found to be TR34/L98H mutations. Microsatellite genotyping clearly differentiated the strains with the TR34/L98H mutation in the cyp51A gene from the strains with no mutation in this gene.

Conclusions

The rate of observed azole resistance of A. fumigatus isolates was low in this study, but the fact that more than half of the examined strains had the wild-type cyp51A gene supports the idea that other mechanisms of resistance are gradually increasing.
Population pharmacokinetics of ethambutol in African children: a pooled analysis
Authors: Tikiso Tjokosela , McIlleron Helen , Abdelwahab Mahmoud Tareq , Bekker Adrie , Hesseling Anneke , Chabala Chishala , Davies Geraint , Zar Heather J , Rabie Helena , Andrieux-Meyer Isabelle , Lee Janice , Wiesner Lubbe , Cotton Mark F , Denti Paolo
Published: April 2022

Objectives

Ethambutol protects against the development of resistance to co-administered drugs in the intensive phase of first-line anti-TB treatment in children. It is especially relevant in settings with a high prevalence of HIV or isoniazid resistance. We describe the population pharmacokinetics of ethambutol in children with TB to guide dosing in this population.

Methods

We pooled data from 188 intensively sampled children from the DATiC, DNDi and SHINE studies, who received 15–25 mg/kg ethambutol daily according to WHO guidelines. The median (range) age and weight of the cohort were 1.9 (0.3–12.6) years and 9.6 (3.9–34.5) kg, respectively. Children with HIV (HIV+; n = 103) received ART (lopinavir/ritonavir in 92%).

Results

Ethambutol pharmacokinetics were best described by a two-compartment model with first-order elimination and absorption transit compartments. Clearance was estimated to reach 50% of its mature value by 2 months after birth and 99% by 3 years. Typical steady-state apparent clearance in a 10 kg child was 15.9 L/h. In HIV+ children on lopinavir/ritonavir, bioavailability was reduced by 32% [median (IQR) steady-state Cmax = 0.882 (0.669–1.28) versus 1.66 (1.21–2.15) mg/L). In young children, bioavailability correlated with age. At birth, bioavailability was 73.1% of that in children 3.16 years or older.

Conclusions

To obtain exposure within the 2–6 mg/L recommended range for Cmax, the current doses must be doubled (or tripled with HIV+ children on lopinavir/ritonavir) for paediatric patients. This raises concerns regarding the potential for ocular toxicity, which would require evaluation.
Resistance to empirical β-lactams recommended in febrile neutropenia guidelines in Gram-negative bacilli bloodstream infections in Spain: a multicentre study
Authors: Chumbita Mariana , Puerta-Alcalde Pedro , Yáñez Lucrecia , Cuesta Maria Angeles , Chinea Anabelle , Español Morales Ignacio , Fernández Abellán Pascual , Gudiol Carlota , Guerreiro Manuel , González-Sierra Pedro , Rojas Rafael , Sánchez Pina José María , Sánchez Vadillo Irene , Varela Rosario , Vázquez Lourdes , Lopera Carlos , Monzó Patricia , Garcia-Vidal Carolina
Published: April 2022

Objectives

To describe current resistance to the β-lactams empirically recommended in the guidelines in bloodstream infection (BSI) episodes caused by Gram-negative bacilli (GNB).

Methods

Retrospective, multicentre cohort study of the last 50 BSI episodes in haematological patients across 14 university hospitals in Spain. Rates of inappropriate empirical antibiotic therapy (IEAT) and impact on mortality were evaluated.

Results

Of the 700 BSI episodes, 308 (44%) were caused by GNB, mainly Escherichia coli (141; 20.1%), Klebsiella spp. (56; 8%) and Pseudomonas aeruginosa (48; 6.9%). Among GNB BSI episodes, 80 (26%) were caused by MDR isolates. In those caused by Enterobacterales, 25.8% were ESBL producers and 3.5% were carbapenemase producers. Among P. aeruginosa BSI episodes, 18.8% were caused by MDR isolates. Overall, 34.7% of the isolated GNB were resistant to at least one of the three β-lactams recommended in febrile neutropenia guidelines (cefepime, piperacillin/tazobactam and meropenem). Despite extensive compliance with guideline recommendations (91.6%), 16.6% of BSI episodes caused by GNB received IEAT, which was more frequent among MDR GNB isolates (46.3% versus 6.1%; P < 0.001). Thirty day mortality was 14.6%, reaching 21.6% in patients receiving IEAT.

Conclusions

Current resistance to empirical β-lactams recommended in febrile neutropenia guidelines is exceedingly high and IEAT rates are greater than desired. There is an urgent need to adapt guidelines to current epidemiology and better identify patients with a high risk of developing MDR GNB infection.
Risk factors for carriage of antimicrobial-resistant bacteria in community dwelling-children in the Asia-Pacific region: a systematic review and meta-analysis
Authors: Chan Yi Qi , Chen Kailin , Chua Gilbert T. , Wu Peng , Tung Keith T. S. , Tsang Hing Wai , Lung David , Ip Patrick , Chui Celine S. L.
Published: April 2022

Background

Antimicrobial resistance is an increasingly important issue in public health as antibiotics are overused. Resistance to antimicrobial agents can pose significant challenges to infection treatment.

Objectives

To evaluate risk factors associated with carriage of antimicrobial-resistant (AMR) bacteria in children in the Asia-Pacific region to consolidate evidence for future implementation of antibiotic prescribing practice.

Methods

Three electronic databases—PubMed, EMBASE and Cochrane Library—were searched. Observational studies that investigated the risk factors for carriage of MRSA, penicillin-resistant Streptococcus pneumoniae, ESBL-producing Escherichia coli and Klebsiella pneumoniae among the paediatric population in community settings in the Asia-Pacific region were considered eligible. Summary statistics from the identified studies were pooled using meta-analyses.

Results

From the 4145 search results, 25 papers were included in this review. Sixteen papers were included in the meta-analysis based on reported risk factors. Young age of 2–6 months compared with children aged 7–60 months (OR 2.74, 95% CI: 1.75–4.29), antibiotic use within the past 3 months (OR 2.65, 95% CI: 1.70–4.12), daycare attendance (OR 1.49, 95% CI: 1.17–1.91) and hospital admission within the past 3 months (OR 3.43, 95% CI: 2.13–5.51) were found to be significant risk factors for AMR bacterial carriage, whilst breastfeeding (OR 0.69, 95% CI: 0.60–0.81) and concurrent colonization of S. pneumoniae (OR 0.59, 95% CI: 0.38–0.91) are protective factors.

Conclusions

The findings support that there are a number of significant risk factors associated with carriage of AMR bacteria in the Asia-Pacific paediatric population. To combat antimicrobial resistance in the future, these risk factors should be considered, and measures taken to mitigate associated carriage.
Combination of phage therapy and cefiderocol to successfully treat Pseudomonas aeruginosa cranial osteomyelitis
Authors: Simner Patricia J. , Cherian Jerald , Suh Gina A. , Bergman Yehudit , Beisken Stephan , Fackler Joseph , Lee Martin , Hopkins Robert J. , Tamma Pranita D.
Published: April 2022

Background

Pseudomonas aeruginosa has the ability to exhibit resistance to a broad range of antibiotics, highlighting the importance of identifying alternative or adjunctive treatment options, such as phages.

Patients and methods

We report the case of a 25-year-old male who experienced an accidental electrocution resulting in exposed calvarium in the left parieto-temporal region, complicated by a difficult-to-treat P. aeruginosa (DTR-P. aeruginosa) infection. Cefiderocol was the sole antibiotic with consistent activity against six bacterial isolates obtained from the infected region over a 38 day period.

Results

WGS analysis identified a blaGES-1 gene as well as the MDR efflux pumps MexD and MexX in all six of the patient’s ST235 DTR-P. aeruginosa isolates, when compared with the reference genome P. aeruginosa PA01 and a P. aeruginosa ST235 isolate from an unrelated patient. After debridement of infected scalp and bone, the patient received approximately 6 weeks of cefiderocol in conjunction with IV phage Pa14NPøPASA16. Some improvement was observed after the initiation of cefiderocol; however, sustained local site improvement and haemodynamic stability were not achieved until phage was administered. No medication-related toxicities were observed. The patient remains infection free more than 12 months after completion of therapy.

Conclusions

This report adds to the growing literature that phage therapy may be a safe and effective approach to augment antibiotic therapy for patients infected with drug-resistant pathogens. Furthermore, it highlights the importance of the GES β-lactamase family in contributing to inactivation of a broad range of β-lactam antibiotics in P. aeruginosa, including ceftolozane/tazobactam, ceftazidime/avibactam and imipenem/relebactam.
Point-of-Care: Roadmap for Analytical Characterization and Validation of a High-Sensitivity Cardiac Troponin I Assay in Plasma and Whole Blood Matrices
Authors: Christenson Robert H , Frenk Lisa D S , de Graaf Henk J , van Domburg Trees S Y , Wijnands Frank P G , Foolen Helma W J , Kemper Danielle W M , Bruinen Anne L , Meijering Bernadet D M , Fonville Judith M , de Theije Femke K
Published: April 2022

Background

High-sensitivity cardiac troponin (hs-cTn) assays enable more precise use of traditional diagnostic strategies and earlier rule-out/rule-in at 0/1 h or 0/2 h after presentation of acute myocardial infarction (AMI). Availability of hs-cTn measurements at point-of-care (POC) can improve timely management of AMI patients. A roadmap for regulatory and analytical validation is exemplified with studies with the Atellica VTLi hs-cTnI at POC.

Methods

High-sensitivity performance was assessed with AACC/IFCC expert recommendations. Clinical Laboratory Standards Institute protocols were used for characterizing limit of blank, limit of detection (LoD), limit of quantitation (LoQ), 10% CV, precision, linearity, and analytic specificity with several reagent lots. Bland-Altman, Passing-Bablok, and hematocrit bias plots compared hs-cTnI measurement in lithium-heparin plasma (PL) and whole blood (WB) matrices.

Results

LoB was 0.55 ng/L; LoD and LoQ were 1.24 ng/L and 2.1 ng/Lm for PL and 1.60 ng/L and 3.7 ng/L for WB, respectively. The male 99th percentile is 27 ng/L, and female 99th percentile upper reference limit is 18 ng/L; 10% CVs were 6.7 ng/L for PL and 8.9 ng/L for WB. Also ≥50% of hs-cTnI values for healthy cohorts exceeded the LoD, confirming high-sensitivity performance. Linearity spanned from LoQ to 1250 ng/L. Specificity was >90% for 40 potential interferences; no hook effect was detected. WB and PL correlation was WB = 1.02*plasma + 0.3 ng/L (r = 0.996, n = 152). No hs-cTnI association with hematocrit was detected (R2 = 0.003).

Conclusion

This analytical roadmap showed high-sensitivity performance, good analytic characteristics, and excellent PL and WB agreement for the Atellica VTLi hs-cTnI POC system. Essential clinical performance studies in patients by intended POC users may now commence.
Spectrum–Effect Relationships Between High-Performance Liquid Chromatography Fingerprints and Hepatoprotective Activities of Cuscutae Semen
Authors: Liang Hui-Ting , Xiao Ping-Ting , Jiang Zheng-Meng , Wang Jian-Wei , Liu E-Hu
Published: April 2022

Background

Cuscutae Semen (CS) is a commonly used hepatoprotective traditional Chinese medicine, but the chemical components responsible for its hepatoprotective activity are unclear.

Objective

The purpose of this study was to evaluate the spectrum–effect relationships between HPLC fingerprints and hepatoprotective effects of CS, and to identify its bioactive components.

Methods

Phytochemical isolation of CS extracts was first carried out and 14 potential bioactive compounds were obtained. Chemical fingerprinting was performed on 27 batches of CS from different sources by HPLC, and further analyzed by similarity analysis (SA) and hierarchical clustering analysis (HCA). Pharmacodynamic testing was performed in a CCl4-induced, acute liver injury cell model to assess the hepatoprotective activity of CS by measuring the cell viability and levels of alanine transaminase (ALT) and aspartate aminotransferase (AST). Bivariate correlations analysis (BCA) and orthogonal projections to latent structures (OPLS) were used to analyze the spectrum–effect relationships of CS.

Results

The results showed that the chemical fingerprints of CS were closely correlated with its hepatoprotective activity. Peaks 1, 10, 18, 19, 21, 22, and 24 might be potential hepatoprotective compounds in CS, and the validation experiments of isolated compounds indicated that chlorogenic acid (P10), hyperoside (P21), isoquercitrin (P22), and astragalin (P24) were the main hepatoprotective components.

Conclusion

By combining chemical fingerprints with hepatoprotective evaluation, the present study provides important guidance for QC and clinical use of CS.

Highlights

(1) Ten potential bioactive compounds were isolated from CS; (2) The spectrum-effect relationship of CS was molded by HPLC and analysed by OPLS and BCA. (3) Four compounds including chlorogenic acid were the main hepatoprotective components.
Impact of Telehealth on Medication Adherence in Chronic Gastrointestinal Diseases
Authors: Kim Hyun Jae , Tomaszewski Marcel , Zhao Billy , Lam Eric , Enns Robert , Bressler Brian , Moosavi Sarvee
Published: April 2022

Background

With the COVID-19 pandemic, the demand and availability of telehealth in outpatient care has had exponential growth. Although use of telehealth has been studied and validated for various medical specialties, relatively few studies have looked at its role in gastroenterology.

Aim

To assess effectiveness of telehealth medicine in gastroenterology by comparing medication adherence rate for patients seen with telehealth and traditional in-person appointment for various gastrointestinal conditions.

Methods

Retrospective chart review of patients seen in outpatient gastroenterology clinic was performed to identify patients who were given prescription to fill either through telehealth or in-person appointment. By using provincial pharmacy database, we determined the prescription fill rate.

Results

A total of 206 patients were identified who were provided new prescriptions or prescription renewal at their gastroenterology clinic visit. One hundred and three patients were seen through in-person visit during pre-pandemic period, and 103 patients were seen through telehealth appointment during COVID-19 pandemic. The mean age of patients was 49.2 years (55% female). On average, patients had 4.7 previous visits with their gastroenterologists before their visit. IBD management was the most common reason for visits (37.9% and 46.6% in telehealth and in-person groups, respectively). Prescription fill rate for patients seen through telehealth was 92.2% compared to 81.6% for the in-person group (OR: 2.69, 95% CI: 1.12–6.45; P = 0.023).

Conclusions

Medication adherence rate for telehealth visits was higher than for in-patient visits. These findings suggest that telehealth can be an effective method of care delivery, especially for patients with chronic gastrointestinal conditions like IBD.
Effect of salt and brine-beet juice de-icer on osmoregulatory physiology of the freshwater amphipod Hyalella azteca (Saussure, 1858) (Amphipoda: Hyalellidae)
Authors: Picinic Britney , Durant Andrea , Donini Andrew
Published: April 2022

The anthropogenic salinization of freshwater is concerning because it can negatively impact the success and survival of freshwater animals. Road salt (NaCl) in cold climates contributes to salinization and organic based de-icers have been developed to mitigate the effects of NaCl on freshwater. One of these de-icers is sugar beet juice, and few studies have examined its effects on freshwater animals. We exposed Hyalella azteca (Saussure, 1858), a freshwater amphipod, to different concentrations of NaCl (salt-contaminated water or SCW) and a NaCl brine and beet-juice mixture used as a de-icing product (brine-beet juice de-icer, BBJD). The LC50 of NaCl on H. azteca was 12.8 g l–1 and for BBJD was 4.6% (which at that percentage contained ~ 4.2 g l–1 Na+). Sub-lethal doses of SCW elevated hemolymph Na+ and BBJD exposure resulted in elevated K+ concentration as well as acidification of the hemolymph. Both Na+/K+ ATPase (NKA) and V-type H+-ATPase (VA) were localized to the coxal gills, whereas only NKA was found in the sternal gills. There was a qualitatively apparent decrease in expression of NKA in the gills of SCW-treated amphipods. NKA and VA expression qualitatively increased with BBJD exposure in the gut. The NKA and VA activity in whole-body homogenates was lower in BBJD and SCW. Results show that Hyalella azteca responds to SCW and BBJD by altering parameters of ionoregulatory physiology in different ways.
Dividing a sphere into equal-area and/or equilateral spherical polygons
Authors: Rezaee Javan Anooshe , Lee Ting-Uei , Xie Yi Min
Published: April 2022

Dividing a sphere uniformly into equal-area or equilateral spherical polygons is useful for a wide variety of practical applications. However, achieving such a uniform subdivision of a sphere is a challenging task. This study investigates two classes of sphere subdivisions through numerical approximation: (i) dividing a sphere into spherical polygons of equal area; and (ii) dividing a sphere into spherical polygons with a single length for all edges. A computational workflow is developed that proved to be efficient on the selected case studies. First, the subdivisions are obtained based on spheres initially composed of spherical quadrangles. New vertices are allowed to be created within the initial segments to generate subcomponents. This approach offers new opportunities to control the area and edge length of generated subdivided spherical polygons through the free movement of distributed points within the initial segments without restricting the boundary points. A series of examples are presented in this work to demonstrate that the proposed approach can effectively obtain a range of equal-area or equilateral spherical quadrilateral subdivisions. It is found that creating gaps between initial subdivided segments enables the generation of equilateral spherical quadrangles. Secondly, this study examines spherical pentagonal and Goldberg polyhedral subdivisions for equal area and/or equal edge length. In the spherical pentagonal subdivision, gaps on the sphere are not required to achieve equal edge length. Besides, there is much flexibility in obtaining either the equal area or equilateral geometry in the spherical Goldberg polyhedral subdivisions. Thirdly, this study has discovered two novel Goldberg spherical subdivisions that simultaneously exhibit equal area and equal edge length.
Future landscape visualization using a city digital twin: integration of augmented reality and drones with implementation of 3D model-based occlusion handling
Authors: Kikuchi Naoki , Fukuda Tomohiro , Yabuki Nobuyoshi
Published: April 2022

The integration of augmented reality and drones allows past and future landscapes to be visualized from an aerial perspective. However, these visualizations still suffer from the occlusion problem, where the three-dimensional (3D) virtual model displayed in the real world is in front of a real-world object. Currently, city digital twins are essential for the sustainable development of cities and the development of detailed 3D models of cities. By visualizing the city digital twin, augmented reality can facilitate the participation of nonexpert citizens in the decision-making process of urban design, but research examples are limited. Here, using detailed city 3D models, we develop a digital-twin approach to outdoor augmented reality with occlusion handling for both first-person and bird’s-eye views. In a verification experiment, the occlusion handling accuracy of the prototype system was measured to be about 0.8 using intersection over union. The frame rate of the entire prototype system was about 30 fps, and the delay between the controller and the augmented reality device was about 3 s. The internet-based system architecture was developed to integrate augmented reality and drone systems. Our system allows multiple stakeholders involved in building construction projects to observe aerial perspectives of those projects, both on-site and off-site via an internet browser, using augmented reality with occlusion handling.
Submarine Communication Cables and the Law of Armed Conflict: Some Enduring Uncertainties, and Some Proposals, as to Characterization
Authors: McLaughlin Rob , Paige Tamsin Phillipa , Guilfoyle Douglas
Published: April 2022

Submarine data cables are of fundamental strategic consequence. However, two intensely context-sensitive and contemporary sets of questions about how these cables are to be dealt with by the law of armed conflict remain—questions which state practice during the two World Wars either did not resolve or did not need to address. Through an examination of the relevant legal history and current law, this article seeks to explore potential answers to these question sets. The first question set relates to the general approach to be adopted when dealing with submarine data cables within LOAC: a sui generis regime; discrete analogy; or general principles? The second question set addresses three lingering queries regarding legal characterization of submarine data cables for LOAC purposes, namely: (i) Are they ordinary military objectives? (ii) Can they be considered neutral objects? (iii) How do we assess proportionality in relation to attack on submarine data cables? The analysis concludes that a modified application of the ordinary rule of proportionality in LOAC targeting, noting some of the difficulties surrounding the concepts of incidental damage in this context, offers the most useful way forward.