bluuebunny/crossref_metadata_2025 huggingface dataset:
Reliability analysis for NOMA‐based UAV assisted short packet communication
Authors: Hu Hang , Han Huizhu , Huang Yangchao , Kang Qiaoyan , Si Jiangbo , Zhao Senhao , Wang Jing
Published: July 2023

This paper introduces the short packet transmission in non‐orthogonal multiple access (NOMA)‐based unmanned aerial vehicle (UAV) assisted relay communication system. Short packet transmission has considerable potential to decrease the transmission latency of UAV communication, and NOMA can effectively enhance the spectrum efficiency and fairness. To improve the reliability of the system, an effective packet error rate (PER) minimization problem within short packet transmission is proposed by jointly optimizing the packet length, UAV placement, and power allocation under the reliability requirement and total power constraints. To address the intricate PER minimization problem, the optimization problem is firstly decomposed into three sub‐problems, and the corresponding monotonicity and convexity are analyzed, respectively. Then, an overall iterative optimization algorithm for PER minimization based on alternating direction method of multipliers algorithm and optimal solution algorithm is formulated by solving the three sub‐problems in an iterative manner. Simulation results validate the effectiveness and convergence of the proposed NOMA scheme and overall iterative optimization algorithm, respectively.
Command filtered backstepping control of constrained flexible joint robotic manipulator
Authors: Arefi Mohammad Mehdi , Vafamand Navid , Homayoun Behrouz , Davoodi Mohammadreza
Published: July 2023

Here, an adaptive radial basis function (RBF) neural network (NN) backstepping controller is proposed for a class of input‐constrained flexible joint robotic manipulators represented by strict‐feedback form with unknown terms, external stochastic disturbance, and output disturbance. The proposed approach is robust against both deterministic and stochastic uncertainties and disturbances and copes with the control input amplitude saturation. Moreover, by deploying the minimal learning parameter method and command filter technique, the computational burden of derivative terms and adaptive terms greatly decreases. Considering the mean‐value theorem assists us to avoid the need for having the input saturation bounds in prior. The suggested tracking control scheme mandates the closed‐loop system states to be semi‐globally bounded‐in‐probability. Also, a quartic Barrier Lyapunov function is utilized to force the tracking error to be confined within a pre‐chosen small region around the origin. Eventually, a numerical simulation of a flexible joint robot manipulator with a single link is performed to show the effectiveness and performance of the developed control method.
Multi‐stage energy‐risk adjustments using practical Byzantine fault tolerance consensus for blockchain‐powered peer‐to‐peer transactive markets
Authors: Mohan Vivek , Dhinakaran Vishnu , Gangadharan Mallika , Modekurti Aditya , M Shyam , M Jisma
Published: July 2023

The energy risk associated with distributed energy resources is inevitable in peer‐to‐peer (P2P) transactive energy markets owing to mismatches between energy commitments and metered measurements. However, adjusting these possible mismatches by progressive revision of the energy commitments in the rolling time horizon mitigates the energy risk, and thereby mitigates the financial risk for prosumers. In this study, the conditional value at risk (CVaR) is used to estimate the risk value for each prosumer. The energy offers that are riskier than CVaR‐based threshold values are reduced in an ‘adjustment bid’. A new pricing mechanism for these adjustment bids is introduced, which varies with historical deviations of a prosumer from energy commitments. This market framework and pricing mechanism are simulated through a blockchain network hosted on a Python Django server using the practical Byzantine fault tolerance consensus algorithm to guarantee network immutability and data privacy. Efforts to mitigate such mismatches between ex ante and ex post energy values incentivise risk‐aware participation in P2P markets. In addition, the welfare of both prosumers and consumers improves with their participation in the proposed market framework. Furthermore, implementing a network using blockchain technology guarantees the privacy of bidding data and provides a secure transaction platform.
Polarization-dependent beam shifts upon metallic reflection in high-contrast imagers and telescopes
Authors: van Holstein R. G. , Keller C. U. , Snik F. , Bos S. P.
Published: July 2023

Context. To directly image rocky exoplanets in reflected (polarized) light, future space- and ground-based high-contrast imagers and telescopes aim to reach extreme contrasts at close separations from the star. However, the achievable contrast will be limited by reflection-induced polarization aberrations. While polarization aberrations can be modeled with numerical codes, these computations provide little insight into the full range of effects, their origin and characteristics, and possible ways to mitigate them.

Aims. We aim to understand polarization aberrations produced by reflection off flat metallic mirrors at the fundamental level.

Methods. We used polarization ray tracing to numerically compute polarization aberrations and interpret the results in terms of the polarization-dependent spatial and angular Goos-Hänchen and Imbert-Federov shifts of the beam of light as described with closed-form mathematical expressions in the physics literature.

Results. We find that all four beam shifts are fully reproduced by polarization ray tracing. We study the origin and characteristics of the shifts as well as the dependence of their size and direction on the beam intensity profile, incident polarization state, angle of incidence, mirror material, and wavelength. Of the four beam shifts, only the spatial Goos-Hänchen and Imbert-Federov shifts are relevant for high-contrast imagers and telescopes because these shifts are visible in the focal plane and create a polarization structure in the point-spread function that reduces the performance of coronagraphs and the polarimetric speckle suppression close to the star.

Conclusions. Our study provides a fundamental understanding of the polarization aberrations resulting from reflection off flat metallic mirrors in terms of beam shifts and lays out the analytical and numerical tools to describe these shifts. The beam shifts in an optical system can be mitigated by keeping the f-numbers large and angles of incidence small. Most importantly, mirror coatings should not be optimized for maximum reflectivity, but should be designed to have a retardance close to 180°. The insights from our study can be applied to improve the performance of SPHERE-ZIMPOL at the VLT and future telescopes and instruments such as the Roman Space Telescope, the Habitable Worlds Observatory, GMagAO-X at the GMT, PSI at the TMT, and PCS (or EPICS) at the ELT.
Improved thermonuclear rate of42Ti(p,γ)43V and its astrophysical implication in therpprocess
Authors: Hou S. Q. , Iliadis C. , Pignatari M. , Liu J. B. , Trueman T. C. L. , Li J. G. , Xu X. X.
Published: July 2023

Context.Accurate42Ti(p,γ)43V reaction rates are crucial for understanding the nucleosynthesis path of the rapid capture process (rpprocess) that occurs in X-ray bursts.

Aims.We aim to improve the thermonuclear rates of42Ti(p,γ)43V based on more complete resonance information and a more accurate direct component, together with the recently released nuclear masses data. We also explore the impact of the newly obtained rates on therpprocess.

Methods.We reevaluated the reaction rate of42Ti(p,γ)43V by the sum of the isolated resonance contribution instead of the Hauser-Feshbach statistical model. We used a Monte Carlo method to derive the associated uncertainties of new rates. The nucleosynthesis simulations were performed via the NuGrid post-processing code ppn.

Results.The new rates differ from previous estimations due to the use of a series of updated resonance parameters and a direct S factor. Compared with the previous results from the Hauser-Feshbach statistical model, which assumes compound nucleus43V with a sufficiently high-level density in the energy region of astrophysical interest, large differences exist over the entire temperature region ofrp-process interest, up to two orders of magnitude. We consistently calculated the photodisintegration rate using our new nuclear masses via the detailed balance principle, and found the discrepancies among the different reverse rates are much larger than those for the forward rate, up to ten orders of magnitude at the temperature of 108K. Using a trajectory with a peak temperature of 1.95×109K, we performed therp-process nucleosynthesis simulations to investigate the impact of the new rates. Our calculations show that the adoption of the new forward and reverse rates result in abundance variations for Sc and Ca of 128% and 49%, respectively, compared to the variations for the statistical model rates. On the other hand, the overall abundance pattern is not significantly affected. The results of using new rates also confirm that therp-process path does not bypass the isotope43V.

Conclusions.Our study found that the Hauser-Feshbach statistical model is inappropriate to the reaction rate evaluation for42Ti(p,γ)43V. The adoption of the new rates confirms that the reaction path of42Ti(p,γ)43V(p,γ)44Cr(β+)44V is a key branch of therpprocess in X-ray bursts.
Immediate Post-LVAD Implant Support: Two Approaches
Authors: Syracuse Phillip L. , Yager Carolyn , Smedira Nicholas , Savage Robert M.
Published: July 2023

Increased use of left ventricular assist devices (LVAD) as bridges to transplant has revealed the need for short-term right heart support for deairing and right ventricular recovery. The two approaches described are implemented as the patient is weaned from regular cardiopulmonary bypass. Dependent on patient needs, the surgeon may select a high-flow or low-flow approach to what is essentially right heart bypass. Both methods use the existing venous drainage from the right side of the heart. The higher flow returns blood through a 0.25-in tube connected to a modified adult vent (AV) to the pulmonary artery (PA). This provides flows as high as 3.5 L/min. The low-flow method uses the cardioplegia line, which goes unused during LVAD insertion. It is attached to the same modified AV cannula, placed into the PA, with flows between 400 and 600 ml/min. Each method has its advantages, disadvantages, and quirks. The results are functionally successful in allowing support of the right heart and deairing of the ventricular device.
Flooding the Surgical Field With Carbon Dioxide During Open Heart Surgery Improves Segmental Wall Motion
Authors: Skidmore Kimberly L. , Jones Clinton , DeWet Charl
Published: July 2023

Air embolization to the coronary arteries is a common cause of myocardial ischemia during open heart surgery. Carbon dioxide emboli may be absorbed faster than air emboli. In this randomized, double blind, placebo-controlled trial, we determined that flooding the surgical field with carbon dioxide is associated with improved myocardial function assessed by trans-esophageal echocardiography. Forty-three valve surgeries were randomized to insufflation of 6 L/min of carbon dioxide or placebo through a Jackson Pratt drain into the pericardium during cardiopulmonary bypass. During rewarming, as pulse pressure rose above 10 mmHg, two observers graded severity of bubbles in the left heart. Two other observers evaluated wall motion in the transgastric midpapillary short axis view of the left ventricle using transesophageal echocardiography. Compared with baseline average scores among all walls (carbon dioxide, 1.42 ± 0.46; placebo, 1.39 ± 0.45), worsening of wall motion was less at 1 minute in the carbon dioxide (1.60 ± 0.62) than in the placebo group (1.95 ± 0.54; p = 0.0266). Better wall motion tended to persist in the carbon dioxide group at 10 (1.58 ± 0.59 vs. 1.77 ± 0.6) and 60 minutes (1.61 ± 0.45 vs. 1.66 ± 0.58). Particularly, the inferior wall tended toward transiently better function in the carbon dioxide group (at baseline and 1, 10, and 60 minutes: placebo, 1.62 ± 0.72, 2.68 ± 0.79, 2.48 ± 0.95, 2.10 ± 0.9 vs. 1.88 ± 0.97, 2.33 ± 1.1, 2.18 ± 0.96, 2.20 ± 0.94). Preoperative characteristics, length of bypass, anesthesia time, hospitalization, and intensive care unit stay were not different. We recommend administration of carbon dioxide because it may improve myocardial function. We describe how to avoid adverse effects of giving carbon dioxide by filtering the supply, continuously managing its level during bypass, increasing sweep speeds, continuously analyzing the in-line blood gas, and avoiding suctioning gases in the field into the cardiotomy reservoir.
Evaluating the Efficacy of Intra-Aortic Balloon Pump Timing Using the Auto-Timing Mode of Operation With the Datascope CS100
Authors: Osentowski Melissa K. , Holt David W.
Published: July 2023

The intra-aortic balloon pump (IABP) was first introduced by Moulopoulos et al. in 1962 and was described clinically by Kantrowitz et al. in 1968. The subsequent development of the IABP has resulted in its widespread application, resulting in >70,000 applications per year, making it the most common cardiac assist device after pharmacologic intervention. The correct timing of the inflation and deflation of this device is critical to it being clinically advantageous to the patient. The purpose of this study was primarily to examine the Datascope CS100 automated timing of inflation and deflation, and secondarily, to create an awareness of the risks of solely relying on technology for patient treatment decisions in lieu of clinical evaluative skills. Timing data were collected from 165 IABP patients from January 1, 2003 to March 31, 2005 using the Datascope series System 97, System 98, and CS100 IABP consoles. Timing criteria used in the evaluation of the IABP in this study included proper inflation, defined as inflation at the dicrotic notch of arterial pressure waveform, and proper deflation, resulting in a presystolic decrease of diastolic pressure by 5–10 mmHg. These parameters were evaluated by examining a printed strip from the IABP console after timing selection stabilization. Before implementation of the CS100, 78.6% of inflations and 53.6% of deflations were correct when using the criteria listed above. After implementation of the CS100, 83.3% of inflations were correct and 44.4% of deflations were correct. Although improvement in consistency of IABP inflation quality was observed, a net decrease in the quality of IABP deflations was also observed. Total reliance on the auto-timing operation mode of the CS100 may not be warranted, and imposing clinical judgment in therapeutic application is necessary to avoid dangerous timing errors. An awareness of the dangers of solely relying on technology for patient treatment decisions vs. the use of technology combined with clinical evaluative skills for assessing therapeutic intervention to improve patient care is discussed.
Trans-Aortic Counterpulsation: A Viable Alternative?
Authors: Datt Bharat , Hutchison Lisa , Peniston Charles
Published: July 2023

Transthoracic intra-aortic balloon pump (IABP) insertion has been a relatively rare and uncommon procedure. However, it is an established beneficial option in patients with severe peripheral vascular disease (PVD) accompanied with bi-lateral femoral arterial occlusion. There are several viable alternatives to trans-aortic IABP insertion, including trans-axillary or in abdominal aorta (requiring a laparotomy). Cardiac surgery has the advantage of an open sternum, facilitating effortless direct intraaortic balloon (IAB) insertion into the aorta. The IAB can be inserted either through a 9-mm graft or directly into the ascending aorta. During cardiac surgery, direct insertion into the ascending aorta with the balloon tip lying distally in the abdominal aorta is facilitated with an open sternum. The base of the balloon lies ∼2 cm below the left subclavian and can be confirmed through a trans-esophageal echocardiogram (TEE). Elimination of a graft insertion saves the team from time-consuming maneuvers and additional hemorrhagic complications. In our experience, postoperative vasoplegic syndrome coupled with myocardial edema contributed to patent instability and was treated with vasopressin and transthoracic IAB insertion. The CS 100 (Datascope Corp., Mahwah, NJ) console allowed the ability to time the balloon accurately. This case report details our experience with one such patient and establishes trans-aortic counter-pulsation as a safe and viable option in patients with severe PVD, where percutaneous insertion is precluded or has failed.
Innovative Design to Prevent Reversal of Roller Blood Pump Rotation in the Event of Electromechanical Failure: An Easy Solution to a Devastating Problem
Authors: Skoletsky Jennifer S. , White Brian T. , Austin Jon W.
Published: July 2023

Despite the advanced technologies of battery back-up for heart-lung consoles and the availability of system-wide generators, electromechanical failure is still occurring. Several heartlung machine manufacturers still provide unsafe handcranking devices to use in the case of an emergency while using a roller blood pump. A new design has been engineered to eliminate safety and quality issues for the perfusionist and the patient when the need for handcranking presents itself. A ratchet-style handcranking device was fabricated by means of a steel plate with adjustable pins. The adjustable pins allow for use with different models of the Cobe, Stockert, and Jostra heart-lung consoles, which contain roller pumps with 180° roller heads. Additional modifications such as a 1:2 transmission and fluorescent markers are also used in the design. This innovative design is an improvement in safety compared with the current handcrank provided by Cobe, Stockert, and Jostra. With this modified handcranking device, accidental reverse rotation of the roller pump head cannot occur. Fluorescent markers will improve visualization of the pump head in low-light situations. The ergonomic design improves efficiency by reducing fatigue. Most importantly, a “safe” safety device will replace the current design provided by these manufacturers, thus improving the quality of care by health care providers.
Rupture of Extra-Corporeal Circuit Tubing During Cardiopulmonary Bypass
Authors: Krishna Cheemalapati Sai , Kumar Palli Venkata Naresh , Satpathy Soumya Kanta , Mohan Kanteti Ram , Babu Vedangi Ramesh
Published: July 2023

Roller pumps are widely used for cardiopulmonary bypass in developing nations by virtue of proven safety during several years of institutional use and cost effectiveness. However, careful adjustment of roller occlusion is needed because they are known to cause spallation, tubing wear, and the occasional incident of rupture of tubing in the extracorporeal circuit. Rupture of polyvinylchloride tubing in the pump raceway during repair of a ventricular septal defect in a 4-year-old child is discussed. The event was managed by exclusion and replacement of the defective tubing during a short period of arrest. Use of an inappropriate boot pump and failure to detect its inclusion in the bypass circuit was a significant departure from protocol. However, because occlusion settings and duration of perfusion were within acceptable limits, a manufacturing flaw could also have contributed to tubing failure, and the event may or may not have been averted by the use of larger tubing. In conclusion, this incident reiterates the need for adherence to established protocol during assembly of the pump and draws attention to the fact that tubing integrity is not a guarantee and vigilance is warranted to handle its failure.
Trends and Emerging Technologies in Extracorporeal Life Support: Results of the 2006 ECLS Survey
Authors: Sievert Alicia N. , Shackelford Anthony G. , McCall Mary M.
Published: July 2023

Extracorporeal life support (ECLS) is a procedure used to support the failing heart and/or lungs via a heart lung machine. Over 145 institutions perform this practice in the United States with more than 24,000 ECLS cases recorded. While many articles are published each year on common perfusion practice, little information is shared on emerging technologies in ECLS and common practices among perfusionists and ECLS specialists. This article presents our 2006 ECLS survey results and discusses emerging technologies and management topics new to the ECLS arena. ECLS specialists were asked to participate in an online survey. Two hundred twenty-two ECLS specialists responded. This survey suggests positive displacement roller pumps are still the leading pump used for ECLS 122/188 (64.9%). Silicone membrane oxygenators are used by responders 75% of the time for longterm use, while hollow fiber membrane oxygenators are used 44%. Forty-five percent of responders are using heparin or biocoated circuits exclusively, while 14.6% restrict their use to specific subpopulations. The most common coating is heparin coating (67.9%). Activated clotting time (ACT) management is still standard of care for coagulation monitoring (98%), while partial thromboplastin time (PTT) follows at 71.7%. The interquartile range for ACTs is 160–220 seconds and 160–200 seconds with active bleeding. This article suggests ECLS specialists are beginning to incorporate different technology into their practice, such as centrifugal pumps with hollow fiber oxygenators and coated-circuits.
Treatment of Malperfusion during Surgery for Type A Aortic Dissection
Authors: Lentini Salvatore , Savasta Marcello , Ciuffreda Francesco , La Monaca Marco , Gaeta Roberto
Published: July 2023

During surgery for acute type A aortic dissection, malperfusion may occur during cardiopulmonary bypass. Retrograde perfusion trough femoral cannulation is considered a predisposing factor. However, this may occur even with antegrade perfusion, because of the presence of multiple flaps or compression of the true lumen by the false lumen. In this particular setting, the aim is to reach a perfusion of the true lumen of the dissected aorta. A technique of epicardial ultrasound-guided direct cannulation of the dissected aorta’s true lumen by a Seldinger technique may help in those cases. We describe the technique with particular interest to the epicardial ultrasound control and the type of arterial cannula to be inserted by the Seldinger technique.
Preoperative Hyponatremia and Cardiopulmonary Bypass: Yet Another Factor for Cerebral Dysfunction?
Authors: Warwick Richard , Palmer Kenneth , Johnson Ian , Poullis Michael
Published: July 2023

Hyponatremia is common in patients prior to cardiopulmonary bypass (CPB), usually secondary to diuretic therapy. Rapid correction of chronic hyponatremia, which potentially occurs on commencing CPB, may in susceptible patients result in central pontine myelomatosis. There are three parts to this study. Part 1: Patients (n= 170) undergoing CPB with preoperative hyponatremia were analyzed by degree of hyponatremia, additive EuroSCORE, length of stay – intensive care and total hospital, and mortality. Part 2: Sodium concentrations of different prime constituents used clinically were collated from the literature. Part 3: Mathematical modeling of the effects of patient size, sex, preoperative hemoglobin, prime solution, and prime volume with regard to the effect on serum sodium during cardiopulmonary bypass was analyzed, assuming a preoperative serum sodium of 125 mmol/L. Part 1: Patients with preoperative hyponatremia, even after matching by additive EuroSCORE, have longer length of stay – intensive care and total hospital, but not significantly different mortality rates. Part 2: Sodium concentrations of different primes used clinically varied from 0 mmol/L to 160 mmol/L. Part 3: Mathematical modeling revealed that patient size, sex, preoperative hemoglobin, prime solution, and prime volume all can exert a significant effect on serum sodium on initiation of cardiopulmonary bypass. Further work is needed to evaluate the roles of sudden changes in serum sodium, with regard to a rapid correction of chronic hyponatremia, or the rapid creation of acute hyponatremia, and cerebral outcomes in patients undergoing CPB.
Layer-averaged approximation of Navier–Stokes system with complex rheologies
Authors: Fernández-Nieto Enrique D. , Garres-Díaz José
Published: July 2023

In this work, we present a family of layer-averaged models for the Navier–Stokes equations. For its derivation, we consider a layerwise linear vertical profile for the horizontal velocity component. As a particular case, we also obtain layer-averaged models with the common layerwise constant approximation of the horizontal velocity. The approximation of the derivatives of the velocity components is set by following the theory of distributions to account for the discontinuities at the internal interfaces. Several models has been proposed, depending on the order of approximation of an asymptotic analysis respect to the shallowness parameter. Then, we obtain a hydrostatic model with vertical viscous effects, a hydrostatic model where the pressure depends on the stress tensor, and fully non-hydrostatic models, with a complex rheology. It is remarkable that the proposed models generalize plenty of previous models in the literature. Furthermore, all of them satisfy an exact dissipative energy balance. We also propose a model that is second-order accurate in the vertical direction thanks to a correction of the shear stress approximation. Finally, we show how effective the layerwise linear approach is to notably improve, with respect to the layerwise constant method, the approximation of the velocity profile for some geophysical flows. Namely, a Newtonian fluid and some complex viscoplastic (dry granular and Herschel–Bulkley) materials are considered.
A Novel Fibrinogen Mutation p.BβAla68Asp Causes an Inherited Dysfibrinogenemia
Authors: Jia Kaiqi , Zeng Manlin , Zheng Xiaoyong , Xie Haixiao , Yang Lihong , Xie Yaosheng , Wang Mingshan
Published: July 2023

Objective Our study aimed to analyze the phenotype and genotype of a pedigree with inherited dysfibrinogenemia, and preliminarily elucidate the probable pathogenesis.

Methods The one-stage clotting method was used to test the fibrinogen activity (FIB:C), whereas immunoturbidimetry was performed to quantify the fibrinogen antigen (FIB:Ag). Furthermore, DNA sequence analysis was conducted to confirm the site of mutation. Conservation analysis and protein model analysis were performed using online bioinformatics software.

Results The FIB:C and FIB:Ag of the proband were 1.28 and 2.20 g/L, respectively. Gene analysis revealed a heterozygous c.293C > A (p.BβAla68Asp) mutation in FGB. Bioinformatics and modeling analysis suggested that the missense mutation could potentially have a deleterious effect on fibrinogen.

Conclusion The BβAla68Asp mutation in exon 2 of FGB may account for the reduced FIB:C levels observed in the pedigree. To our knowledge, this point mutation is the first report in the world.
The Risk of Developmental Dysplasia of the Hip in Premature Infants with Breech Presentation at Birth
Authors: Osman Ahmed , Jackson Kenneth , Conroy Sara , Seguin John , Slaughter Jonathan L.
Published: July 2023

Objective This article evaluates the risk (defined here as incidence per 1,000 infants) of developmental dysplasia of the hip (DDH) in premature infants undergoing hip ultrasound (HUS) for breech presentation only compared with other indications.

Study Design Retrospective study of infants born between January 1, 2009 and December 31, 2018 at <37 weeks' gestation with a HUS obtained in the first year of life, at Nationwide Children's Hospital, the only available facility for pediatric radiology and orthopaedic services in central Ohio. We calculated risk differences and odds ratios of DDH by the indication of HUS.

Results From 2,397 infants reviewed, 89% underwent HUS for breech presentation only. The local incidence of DDH for infants undergoing HUS for breech-only indication was 15 per 1,000 compared with 155 per 1,000 for infants undergoing HUS for other indications. The odds ratio of DDH diagnosis was 12.1 (95% confidence interval: 7.5, 19.6) for infants undergoing HUS for an indication other than breech presentation only relative to infants undergoing HUS for the indication of breech presentation only.

Conclusion The risk of DDH diagnosis in premature infants undergoing HUS for breech presentation is much lower than those undergoing HUS for clinical concerns and other risk factors. Screening these infants with physical examination may be sufficient.

Key Points
Efficacy and Safety of Aspirin 162 mg for Preeclampsia Prophylaxis in High-Risk Patients
Authors: Ayyash Mariam , Goyert Gregory , Garcia Robyn , Khangura Raminder , Pitts D'Angela , Jacobsen Gordon , Shaman Majid
Published: July 2023

Objective The aim of this study was to compare the safety and efficacy of aspirin 162 mg to the standard recommended dose of 81 mg for preeclampsia prevention.

Study Design A retrospective cohort study of patients at risk for preeclampsia who delivered between January 2013 and December 2020 at Henry Ford Health was performed. Patients were divided into three groups: a no aspirin group, a group treated under an 81 mg aspirin preeclampsia prophylaxis protocol, and a group treated under a 162 mg protocol. Univariate and multivariable logistic regression analyses compared rates of preeclampsia and secondary outcomes between groups. Clinical side effects traditionally associated with aspirin use were also assessed.

Results Of 3,597 patients, 2,266 (63%) were in the no aspirin group, 944 (26%) were in the 81 mg group, and 387 (11%) were in the 162 mg group. The rate of preeclampsia was significantly lower in the 162 mg group (10.1%, odds ratio, 0.68; 95% confidence interval, 0.46–0.99) compared with the 81 mg group (14.2%). The rate of preeclampsia was identical in the no aspirin and 81 mg groups. The rate for postpartum hemorrhage, postpartum hematoma, and intraventricular hemorrhage of the newborn were not significantly different between patients in the 162 and 81 mg groups.

Conclusion We observed a significantly lower rate of preeclampsia in high-risk patients who were treated with the 162 mg dose of aspirin for preeclampsia prophylaxis, and bleeding complications were not seen with the higher dose. Our study suggests that aspirin 162 mg may be considered for prophylaxis in patients at high risk for preeclampsia.

Key Points
The cascade influence of grain trade shocks on countries in the context of the Russia-Ukraine conflict
Authors: Liu Linqing , Wang Weiran , Yan Xiaofei , Shen Mengyun , Chen Haizhi
Published: July 2023

The Russia-Ukraine conflict has severely impacted global food security. This may increase the risk of supply chain disruption in low-income countries that rely heavily on grain imports. This study used production and trade data for wheat, barley and maize from 1995 to 2021 to construct longitudinal trade networks. On this basis, a cascading failure network model of shock propagation was used to identify the direct or indirect dependence of other countries on grain exported from Russia and Ukraine and the impact caused by trade shocks. The results revealed that the interruption of grain exports from Russia and Ukraine has resulted in an increasing impact on the global grain trade year by year and that the wheat trade is the most vulnerable to shock propagation, but it is also the most resilient. Russia and Ukraine interrupt exports of grain, causing more than 50% reduction in direct imports to 30 countries, including Eritrea, Seychelles, Kazakhstan and Mongolia. A shock propagation model that considers indirect dependence yields divergent results, with lower middle income (LM) countries in North Africa, Southeast Asia and West Asia facing supply shocks from reduced imports because they are unable to fully exploit the trade channels to balance grain supply and demand. Under the COVID-19 pandemic, this indirect dependence on imports is more prominent. It is worth noting that Eastern and Southern European countries often act as intermediaries to spread shocks during cascading failures. In the process of shock propagation, the main suppliers of grain include the United States, Canada, France, Argentina and Brazil. After the outbreak of COVID-19, the import demand faced by Australia increased significantly. We also examined how nodal characteristics relate to shock propagation dynamics and country vulnerability, finding that high import diversity, low import dependence and regional characteristics are effective in buffering countries from supply shocks. This study contributes to our understanding of the external supply risks for grain arising from the Russia-Ukraine conflict in a pandemic context, highlights the issue of accessibility in food security and provides trade policy recommendations to mitigate national vulnerability to food insecurity, thereby creating a resilient food trade system.
Risk assessment of radioactive hazards associated with black sand upgrading processes
Authors: Mohamed Tamer G. , Hassan Mostafa , Ismail Mohamed A. , El-Midany Ayman A. , El-Samrah Moamen G.
Published: July 2023

Black sands represent a good source of economic minerals with various industrial applications. However, their radioactive properties may prevent their use in specific applications. In this study, zircon, ilmenite, magnetite, and rutile are four minerals represent more than 75% of the black sand content, were selected to evaluate their Intrinsic radiological properties. The chemical composition of these minerals was determined along with their density and particle size. Then, the activity concentrations of the naturally occurring radioactive nuclides were experimentally determined and the most important radiological hazard indices were calculated. The results indicated that the upgrading process concentrates the natural radioisotopes in some minerals like the zircon and rutile leaving the magnetite and ilmenite with lower content than permissible limits. Moreover, the risk analysis identified the dangerous conditions and situations and suggest possible solutions to reduce these hazardous situations to a minimum and to keep a safe environment for the workers.
pHAPE: a plasmid for production of DNA size marker ladders for gel electrophoresis
Authors: Allen Angel G , Barthelson Karissa , Lardelli Michael
Published: July 2023

DNA size markers (also known as ‘molecular weight markers’ or ‘DNA ladders’) are an essential tool when using gel electrophoresis to identify and purify nucleic acids. However, the cost of these DNA ladders is not insignificant and, over time, impinges on the funds available for research and training in molecular biology. Here, we describe a method for the generation of ‘pHAPE’, a plasmid from which a variety of DNA ladders can be generated via simple restriction enzyme digestions. The pHAPE plasmid can be generated by mutagenesis of the commonly used pBluescript II SK+ phagemid followed by insertion of a 7141 bp sequence (comprised of three smaller, synthetic fragments). Our use of pHAPE allows us some small relief from the ever-rising costs of performing molecular biology experiments (‘Don’t worry, pHAPE’).
Provincializing “web traffic”: data imaginaries and vernacular construction ofliuliangin China
Authors: Zou Sheng
Published: July 2023

This article dehomogenizes the concept of “web traffic” through a keywords-informed approach. It attends to how, in China, the term for “web traffic,” liuliang (流量), is utilized in rich and creative ways. Instantiating bottom-up epistemic practices, the taxonomies, collocations, and wisdom related to liuliang reveal alternative and locally relevant ways in which people imagine, apprehend, and deal with digital media and data in everyday life. They unleash a set of reinvigorating vocabulary for the theorization of web traffic—liquidity, manipulability, portability, socio-spatial differentiation, ideological valence, and mystified power, among others. These new lenses enrich a genuinely global understanding of digital media, enable those in the Global North to comparatively rethink their taken-for-granted experiences of datafication, and democratize the making of media knowledges by addressing the inequality between the Global North and South(s), between experts and non-experts.
Artificial intelligence: a new field of knowledge for nephrologists?
Authors: Fayos De Arizón Leonor , Viera Elizabeth R , Pilco Melissa , Perera Alexandre , De Maeztu Gabriel , Nicolau Anna , Furlano Monica , Torra Roser
Published: July 2023

Artificial intelligence (AI) is a science that involves creating machines that can imitate human intelligence and learn. AI is ubiquitous in our daily lives, from search engines like Google to home assistants like Alexa and, more recently, OpenAI with its chatbot. AI can improve clinical care and research, but its use requires a solid understanding of its fundamentals, the promises and perils of algorithmic fairness, the barriers and solutions to its clinical implementation, and the pathways to developing an AI-competent workforce. The potential of AI in the field of nephrology is vast, particularly in the areas of diagnosis, treatment and prediction. One of the most significant advantages of AI is the ability to improve diagnostic accuracy. Machine learning algorithms can be trained to recognize patterns in patient data, including lab results, imaging and medical history, in order to identify early signs of kidney disease and thereby allow timely diagnoses and prompt initiation of treatment plans that can improve outcomes for patients. In short, AI holds the promise of advancing personalized medicine to new levels. While AI has tremendous potential, there are also significant challenges to its implementation, including data access and quality, data privacy and security, bias, trustworthiness, computing power, AI integration and legal issues. The European Commission's proposed regulatory framework for AI technology will play a significant role in ensuring the safe and ethical implementation of these technologies in the healthcare industry. Training nephrologists in the fundamentals of AI is imperative because traditionally, decision-making pertaining to the diagnosis, prognosis and treatment of renal patients has relied on ingrained practices, whereas AI serves as a powerful tool for swiftly and confidently synthesizing this information.
Classroom Discourse: What Is Conveyed Through Educational Interpretation
Authors: Langer Elizabeth C , Crume Peter K
Published: July 2023

When a deaf or hard-of-hearing child enters a classroom with an interpreter, the goal, and sometimes the assumption, is that they will be granted full access to the classroom experience. This study focuses on the clarity and completeness with which critical elements of classroom discourse are conveyed through the interpretations of 40 educational interpreters. Elements studied include conveyance of main ideas, directions for assignments, relevance strategies, orienting commentary, participation solicitation, mental state reference, and semantic organization. The interpretations clearly and completely conveyed approximately one-third to two-thirds of the information (M = 48.6%) related to these elements of classroom discourse. Frequent omissions and alterations rendered large parts of the message markedly different. Results suggest a need to improve training of educational interpreters, increase communication between teachers and interpreters, provide students supplementary services, and heighten awareness that the interpretation process is fallible in ways that can impact access to classroom discourse.
Trend and early clinical outcomes of off-pump coronary artery bypass grafting in the UK
Authors: Chan Jeremy , Dimagli Arnaldo , Dong Tim , Fudulu Daniel P , Sinha Shubhra , Angelini Gianni D
Published: July 2023

OBJECTIVES

The popularity of off-pump coronary artery bypass grafting (CABG) varies across the world, ranging from 20% in Europe and the USA to 56% in Asia. We present the trend and early clinical outcomes in off pump in the UK.

METHODS

All patients who underwent elective or urgent isolated CABG from 1996 to 2019 were extracted from the National Adult Cardiac Surgery Audit database. The trend in operating surgeons and units volume and training in off pump were analysed. Early clinical outcomes between off- and on-pump CABG were compared using propensity score matching.

RESULTS

A total of 351 422 patients were included. The overall off-pump rate during the study period was 15.17%, it peaked in 2008 (19.8%), followed by a steady decreased to 2018 (7.63%). Its adoption varied across centres and surgeons, ranging from <1% to 48.36% and <1% to 85.5%, respectively, of total cases performed. After propensity score matching for the period 1996–2019, off pump, when compared to on pump, was associated with a lower in-hospital/30-day mortality (1.2% vs 1.5%, P < 0.001), return to theatre (3.7% vs 4.5%, P < 0.001), cerebrovascular accident (transient ischaemic attack: 0.3% vs 0.6%, stroke: 0.3% vs 0.6%, P < 0.001) and deep sternal wound infection (0.8% vs 1.2%, P ≤ 0.001). In a sub-analysis from the introduction of EuroScore II (2012–2019), there were no differences in-hospital/30-day mortality (1.0% vs 1.0%, P = 0.71). However, on pump, had a higher return to theatre (4.2% vs 2.7%, P < 0.001), cerebrovascular accident (transient ischaemic attack: 0.4% vs 0.2%, stroke: 0.5% vs 0.3%, P = 0.003) and deep sternal wound infection (1.0% vs 0.6%, P = 0.004).

CONCLUSIONS

Our data show a decreasing trend in the use of off pump in the UK since 2008. This is likely to be multifactorial and raises the question of whether it should be a specialized revascularization technique.
Anatomic, histologic, and mechanical features of the right atrium: implications for leadless atrial pacemaker implantation
Authors: O’Connor Matthew , Barbero Umberto , Kramer Daniel B , Lee Angela , Hua Alina , Ismail Tevfik , McCarthy Karen P , Niederer Steven , Rinaldi Christopher A , Markides Vias , Clarke John-Ross D , Babu-Narayan Sonya , Ho Siew Yen , Wong Tom
Published: July 2023

Background

Leadless pacemakers (LPs) may mitigate the risk of lead failure and pocket infection related to conventional transvenous pacemakers. Atrial LPs are currently being investigated. However, the optimal and safest implant site is not known.

Objectives

We aimed to evaluate the right atrial (RA) anatomy and the adjacent structures using complementary analytic models [gross anatomy, cardiac magnetic resonance imaging (MRI), and computer simulation], to identify the optimal safest location to implant an atrial LP human.

Methods and results

Wall thickness and anatomic relationships of the RA were studied in 45 formalin-preserved human hearts. In vivo RA anatomy was assessed in 100 cardiac MRI scans. Finally, 3D collision modelling was undertaken assessing for mechanical device interaction. Three potential locations for an atrial LP were identified; the right atrial appendage (RAA) base, apex, and RA lateral wall. The RAA base had a wall thickness of 2.7 ± 1.6 mm, with a low incidence of collision in virtual implants. The anteromedial recess of the RAA apex had a wall thickness of only 1.3 ± 0.4 mm and minimal interaction in the collision modelling. The RA lateral wall thickness was 2.6 ± 0.9 mm but is in close proximity to the phrenic nerve and sinoatrial artery.

Conclusions

Based on anatomical review and 3D modelling, the best compromise for an atrial LP implantation may be the RAA base (low incidence of collision, relatively thick myocardial tissue, and without proximity to relevant epicardial structures); the anteromedial recess of the RAA apex and lateral wall are alternate sites. The mid-RAA, RA/superior vena cava junction, and septum appear to be sub-optimal fixation locations.
Recently formed Antarctic lakes host less diverse benthic bacterial and diatom communities than their older counterparts
Authors: Kollár Jan , Kopalová Kateřina , Kavan Jan , Vrbická Kristýna , Nývlt Daniel , Nedbalová Linda , Stibal Marek , Kohler Tyler J
Published: July 2023

Glacier recession is creating new water bodies in proglacial forelands worldwide, including Antarctica. Yet, it is unknown how microbial communities of recently formed “young” waterbodies (originating decades to a few centuries ago) compare with established “old” counterparts (millennia ago). Here, we compared benthic microbial communities of different lake types on James Ross Island, Antarctic Peninsula, using 16S rDNA metabarcoding and light microscopy to explore bacterial and diatom communities, respectively. We found that the older lakes host significantly more diverse bacterial and diatom communities compared to the young ones. To identify potential mechanisms for these differences, linear models and dbRDA analyses suggested combinations of water temperature, pH, and conductivity to be the most important factors for diversity and community structuring, while differences in geomorphological and hydrological stability, though more difficult to quantify, are likely also influential. These results, along with an indicator species analysis, suggest that physical and chemical constraints associated with individual lakes histories are likely more influential to the assembly of the benthic microbial communities than lake age alone. Collectively, these results improve our understanding of microbial community drivers in Antarctic freshwaters, and help predict how the microbial landscape may shift with future habitat creation within a changing environment.
Genome Dynamics and Temperature Adaptation During Experimental Evolution of Obligate Intracellular Bacteria
Authors: Herrera Paul , Schuster Lisa , Zojer Markus , Na Hyunsoo , Schwarz Jasmin , Wascher Florian , Kempinger Thomas , Regner Andreas , Rattei Thomas , Horn Matthias
Published: July 2023

Evolution experiments with free-living microbes have radically improved our understanding of genome evolution and how microorganisms adapt. Yet there is a paucity of such research focusing on strictly host-associated bacteria, even though they are widespread in nature. Here, we used the Acanthamoeba symbiont Protochlamydia amoebophila, a distant relative of the human pathogen Chlamydia trachomatis and representative of a large group of protist-associated environmental chlamydiae, as a model to study how obligate intracellular symbionts evolve and adapt to elevated temperature, a prerequisite for the pivotal evolutionary leap from protist to endothermic animal hosts. We established 12 replicate populations under two temperatures (20 °C, 30 °C) for 510 bacterial generations (38 months). We then used infectivity assays and pooled whole-genome resequencing to identify any evolved phenotypes and the molecular basis of adaptation in these bacteria. We observed an overall reduction in infectivity of the symbionts evolved at 30 °C, and we identified numerous nonsynonymous mutations and small indels in these symbiont populations, with several variants persisting throughout multiple time points and reaching high frequencies. This suggests that many mutations may have been beneficial and played an adaptive role. Mutated genes within the same temperature regime were more similar than those between temperature regimes. Our results provide insights into the molecular evolution of intracellular bacteria under the constraints of strict host dependance and highly structured populations and suggest that for chlamydial symbionts of protists, temperature adaptation was facilitated through attenuation of symbiont infectivity as a tradeoff to reduce host cell burden.