bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrostatics of Conducting Cylinders and Spheres
Authors: Lekner John
Published: August 2021

Written by a recognized expert in the field, Electrostatics of Conducting Cylinders and Spheres presents the theory in a simple and physical way, beginning with basic principles and moving onto the details of electrostatics of pairs of spheres and of pairs of cylinders. The difficult topic of a finite charged cylinder is also covered. The book presents exact solutions, in closed form where possible, with recent and new results included. Applications to engineering, physical, chemical, and biological problems are also presented.

Key topics include:Fundamentals of the polarizability tensor and capacitance coefficients of an assembly of conductors.Rigorous and thorough theoretical investigation of the electrostatics of spheres and cylinders.Uniform formalism used in the solution for a rich array of problems.

Theoretical and experimental physicists, chemists, and engineers will find this an invaluable reference. It is also suitable for advanced undergraduate and graduate students in electrodynamics.
Bispherical coordinates
Authors: Lekner John
Published: August 2021

Bispherical coordinates are defined and related to cylindrical and to spherical coordinates. We consider geometries where two spheres are external to each other and where one is inside the other. Useful sums and integrals in bispherical coordinates are derived. Solutions of Laplace's equation are given, also in degenerate bispherical coordinates (touching spheres). Coordinates suitable for overlapping spheres are also considered.
Two Spheres in an External Field
Authors: Lekner John
Published: August 2021

This chapter deals with uncharged conducting spheres in an external field. There is charge separation on each sphere (they become polarized), but they remain neutral. When in contact, the combined two-sphere system also has net zero charge. Charged spheres, and the capacitance coefficients of the two-sphere system, are discussed in Chap. 4. The longitudinal and transverse polarizabilities of a pair of spheres are derived. From the polarizabilities the forces and torque on a pair of spheres in an external field are obtained.
Two Charged Spheres
Authors: Lekner John
Published: August 2021

The capacitance coefficients of two spheres are calculated and limiting forms at large and small separations discussed. The (equal and opposite) forces acting between the spheres are calculated, as are the charge distributions on the spheres. The cases where the spheres are held at different potentials are discussed, including the force acting between them. Appendices cover regions of attraction and repulsion between like-charged conducting spheres and charged intersecting spheres.
Sums and Integrals
Authors: Lekner John
Published: August 2021

This final chapter is in effect an Appendix to the book, dealing with mathematical topics that would have been too much of a detour in the text, and would have interrupted a physical development. The main feature is the Abel–Plana formula, which provides an exact correspondence between a sum and certain integrals. The Abel–Plana formula is especially useful in close approach of the sphere or cylinder pairs, when the sums we need converge slowly. There is also a section devoted to proving the mathematical equivalence of apparently different capacitance expressions. An Appendix discusses expansions in powers of a parameter that is small at close approach, and in particular two remarkable series arising in the polarizabilities of a pair of cylinders. These series each have ten successive zero coefficients.
Chitosan-modified biochar immobilised arsenic in root medium and enhanced the growth of zucchini (cv. Courgette d’Italie) seedlings
Authors: Mehmood Sajid , Ahmed Waqas , Imtiaz Muhammad , Qaswar Muhammad , Ikram Muhammad , Bashir Saqib , Rizwan Muhammad , Irshad Sana , Tu Shuxin , Li Weidong , Chen Di-Yun
Published: August 2021

Contamination of arsenic (As) presents a health hazard that affects home gardeners neighbouring contaminated environments. The use of chitosan-modified biochar was investigated to immobilise As(V) from aqueous solution and zucchini seedlings (cv. Courgette d’Italie) were grown as a test crop. The results of characterisation revealed that the presence of chitosan on biochar (BR) surface improved its efficiency of As(V) immobilisation from the contaminated environment. A sorption study further showed that compared with the BR, (BR-C) chitosan-modified biochar (0.1 g) depicted the increased immobilisation of As(V) (10 ppm) from solution. Both Langmuir and Freundlich models fitted well, showing monolayer as well as multilayer sorption. BR-C showed a high Langmuir arsenic sorption capacity of 57.83 mg/g, which effectively decreased the level of As(V) toxicity. As demonstrated in results, As-stress reduced plant growth, seedling length, photosynthetic pigments, soluble sugar, increased hydrogen peroxide contents, and electrolyte leakage percentage. Simultaneously, BR and BR-C were effective against As(V) stress-induced changes in the zucchini plant. Collectively, the results of this study indicate that the modification of BR with chitosan can efficiently immobilised arsenic in the root medium and enhance growth of zucchini under controlled conditions by reducing the uptake of As(V).
Assessment of bike handling during cycling individual time trials with a novel analytical technique adapted from motorcycle racing
Authors: Zignoli Andrea , Biral Francesco , Fornasiero Alessandro , Sanders Dajo , Erp Teun Van , Mateo‐March Manuel , Fontana Federico Y. , Artuso Paolo , Menaspà Paolo , Quod Marc , Giorgi Andrea , Laursen Paul B.
Published: August 2021

A methodology to study bike handling of cyclists during individual time trials (ITT) is presented. Lateral and longitudinal accelerations were estimated from GPS data of professional cyclists (n = 53) racing in two ITT of different length and technical content. Acceleration points were plotted on a plot (g‐g diagram) and they were enclosed in an ellipse. A correlation analysis was conducted between the area of the ellipse and the final ITT ranking. It was hypothesised that a larger area was associated with a better performance. An analytical model for the bike‐cyclist system dynamics was used to conduct a parametric analysis on the influence of riding position on the shape of the g‐g diagram. A moderate (n = 27, r = −0.40, p = 0.038) and a very large (n = 26, r = −0.83, p < 0.0001) association were found between the area of the enclosing ellipse and the final ranking in the two ITT. Interestingly, this association was larger in the shorter race with higher technical content. The analytical model suggested that maximal decelerations are highly influenced by the cycling position, road slope and speed. This investigation, for the first time, explores a novel methodology that can provide insights into bike handling, a large unexplored area of cycling performance.
Analysis of the generation mechanism of the S-shaped J–V curves of MoS2/Si-based solar cells
Authors: Xu He-Ju , Xin Li-Tao , Chen Dong-Qiang , Cong Ri-Dong , Yu Wei
Published: August 2021

Amorphous–microcrystalline MoS2 thin films are fabricated using the sol-gel method to produce MoS2/Si-based solar cells. The generation mechanisms of the S-shaped current density–voltage (J–V) curves of the solar cells are analyzed. To improve the performance of the solar cells and address the problem of the S-shaped J–V curve, a MoS2 film and a p+ layer are introduced into the front and back interfaces of the solar cell, respectively, which leads to the formation of a p–n junction between the p-Si and the MoS2 film as well as ohmic contacts between the MoS2 film and the ITO, improving the S-shaped J–V curve. As a result of the high doping characteristics and the high work function of the p+ layer, a high–low junction is formed between the p+ and p layers along with ohmic contacts between the p+ layer and the Ag electrode. Consequently, the S-shaped J–V curve is eliminated, and a significantly higher current density is achieved at a high voltage. The device exhibits ideal p–n junction rectification characteristics and achieves a high power-conversion efficiency (CE) of 7.55%. The findings of this study may improve the application of MoS2 thin films in silicon-based solar cells, which are expected to be widely used in various silicon-based electronic and optical devices.
Simulation of detection and scattering of sound waves by the lateral line of a fish
Authors: Adamyan V M , Popov I Y , Blinova I V , Zavalniuk V V
Published: August 2021

A solvable model of lateral line of a fish based on a wave equation with additional boundary conditions on a set of isolated points is proposed. Within the framework of this model it is shown that the ratio of pressures on lateral lines on different fish flanks, as well as the cross section of sound scattering on both the lines, strongly depends on angles of incidence of incoming sound waves. The strong angular dependence of the pressure ratio seems to be sufficient for the fish to determine the directions from which the sound is coming.
Integer quantum Hall effect in Kekulé-patterned graphene
Authors: Mohammadi Yawar , Bahrami Samira
Published: August 2021

Y-shaped Kekulé bond textures in a honeycomb lattice on a graphene-copper superlattice have recently been experimentally revealed. In this paper, the effects of such a bond modulation on the transport coefficients of Kekulé-patterned graphene are investigated in the presence of a perpendicular magnetic field. Analytical expressions are derived for the Hall and longitudinal conductivities using the Kubo formula. It is found that the Y-shaped Kekulé bond texture lifts the valley degeneracy of all Landau levels except that of the zero mode, leading to additional plateaus in the Hall conductivity accompanied by a split of the corresponding peaks in the longitudinal conductivity. Consequently, the Hall conductivity is quantized as ± ne
2/h for n = 2, 4, 6, 8, 10, …, excluding some plateaus that disappear due to the complete overlap of the Landau levels of different cones. These results also suggest that DC Hall conductivity measurements will allow us to determine the Kekulé bond texture amplitude.
Theoretical investigation of ferromagnetic resonance in a ferromagnetic thin film with external stress anisotropy
Authors: Zhou Jieyu , Rong Jianhong , Wang Huan , Yun Guohong , Wang Yanan , Zhang Shufei
Published: August 2021

We use the ferromagnetic resonance (FMR) method to study the properties of ferromagnetic thin film, in which external stress anisotropy, fourfold anisotropy and uniaxial anisotropy are considered. The analytical expressions of FMR frequency, linewidth and the imaginary part of magnetic susceptibility are obtained. Our results reveal that the FMR frequency and the imaginary part of magnetic susceptibility are distinctly enhanced, and the frequency linewidth or field linewidth are broadened due to a strong external stress anisotropy field. The hard-axis and easy-axis components of magnetization can be tuned significantly by controlling the intensity and direction of stress and the in-plane uniaxial anisotropy field.
Color-image encryption scheme based on channel fusion and spherical diffraction
Authors: Wang Jun , Zhang Yuan-Xi , Wang Fan , Ni Ren-Jie , Hu Yu-Heng
Published: August 2021

A secure encryption scheme for color images based on channel fusion and spherical diffraction is proposed in this paper. In the proposed encryption scheme, a channel fusion technology based on the discrete wavelet transformation is used to transform color images into single-channel grayscale images, firstly. In the process of transformation, the hyperchaotic system is used to permutate and diffuse the information of red–green–blue (RGB) channels to reduce the correlation of channels. Then the fused image is encrypted by spherical diffraction transform. Finally, the complex-valued diffraction result is decomposed into two real parts by the improved equal module decomposition, which are the ciphertext and the private key. Compared with the traditional color image encryption schemes that encrypt RGB channels separately, the proposed scheme is highly secure and robust.
Exact quantum dynamics study of the H(2S)+SiH+(X1Σ+) reaction on a new potential energy surface of SiH

2+(X2A1)

*
Authors: Zhao Wen-Li , Tan Rui-Shan , Cao Xue-Cheng , Gao Feng , Meng Qing-Tian
Published: August 2021

Based on a new global potential energy surface of

SiH

2
+

(

X
2

A
1

)

, the exact quantum dynamical calculation for the H(2 S) + SiH+(X1Σ+) → H2 + Si+ reaction has been carried out by using the Chebyshev wave packet method. The initial state specified (ν
i = 0, j
i = 0) probabilities, integral cross sections (ICS) and thermal rate constants of the title reaction are calculated. All partial wave contributions up to J = 90 are calculated in exact quantum calculation including the full Coriolis coupling (CC) effect. The dynamical behaviors of probabilities, ICSs and rate constants are found to be in accord with an exothermic reaction without potential barrier. By comparing the probabilities of CC with the corresponding centrifugal sudden (CS) approximation ones, it can be concluded that neglecting CC effect will decrease the collision time, increase the amplitude of oscillation and lead to overestimation or underestimation of the reaction probability. For ICSs and rate constants, it is found that the deviation of CC and CS ICSs is small in the most of collision energy range except for the range of 0 eV–0.05 eV, while the deviation of both rate constants is considerable in the temperature range of 16 K–1000 K.
Theory of multiphoton photoemission disclosing excited states in conduction band of individual TiO2 nanoparticles*
Authors: Li Bochao , Li Hao , Yang Chang , Ji Boyu , Lin Jingquan , Tomie Toshihisa
Published: August 2021

A theory of multiphoton photoemission is derived to explain the experimentally observed monotonic decrease with the wavelength in the electron yield of TiO2 nanoparticles (NPs) by as large as four orders of magnitude. It is found that the fitting parameter corresponds to the energy position of Ti3d eg and t2g states, and the derived theory is a novel diagnostic of excited states in the conduction band, very importantly, applicable to individual NPs. The difference between four-photon slope NPs and three-photon slope NPs is attributed to the difference in defect density. The success of the theory in solving the puzzling result shows that thermal emission from high-lying levels may dominate over direct multiphoton ionization in solids when the photon number larger than four is required.
Propagation of terahertz waves in nonuniform plasma slab under “electromagnetic window”
Authors: Li Hao , Zhang Zheng-Ping , Yang Xin
Published: August 2021

The application of magnetic fields, electric fields, and the increase of the electromagnetic wave frequency are up-and-coming solutions for the blackout problem. Therefore, this study considers the influence of the external magnetic field on the electron flow and the effect of the external electric field on the electron density distribution, and uses the scattering matrix method (SMM) to perform theoretical calculations and analyze the transmission behavior of terahertz waves under different electron densities, magnetic field distributions, and collision frequencies. The results show that the external magnetic field can improve the transmission of terahertz waves at the low-frequency end. Magnetizing the plasma from the direction perpendicular to the incident path can optimize the right-hand polarized wave transmission. The external electric field can increase the transmittance to some extent, and the increase of the collision frequency can suppress the right-hand polarized wave cyclotron resonance caused by the external magnetic field. By adjusting these parameters, it is expected to alleviate the blackout phenomenon to a certain extent.
Utilization of anti–factor Xa levels to guide reversal of oral factor Xa inhibitors in the emergency department
Authors: Zepeski Anne E , Faine Brett A , Merrill Anna E , Sutamtewagul Grerk , Bhagavathi Sharathkumar
Published: August 2021

Purpose

Oral factor Xa inhibitors (FXaIs) are increasingly utilized for outpatient anticoagulation therapy; however, laboratory monitoring is not routinely used to assess the safety and efficacy of these agents. We aimed to evaluate the role of chromogenic anti–factor Xa (anti-Xa) assays in the emergency department (ED) in the setting of patients with an acute bleed or requiring emergent procedures.

Methods

A retrospective review of anti-Xa levels obtained in the ED between June 1, 2019, and April 30, 2020, was completed. Data were collected to describe the clinical setting of anti-Xa level collection, oral FXaIs used before admission, administration of reversal agents, and patient disposition to further characterize the role of anti-Xa levels in the management of rivaroxaban and apixaban reversal.

Results

Thirty anti-Xa levels were included in the final analysis. The median time from sample collection to anti-Xa assay result was 45.9 minutes (interquartile range, 35.3-54.7 minutes). Eleven patients (37%) received anticoagulation reversal after their anti-Xa levels were determined. Anticoagulation reversal agents included either activated prothrombin complex concentrates (aPCCs) or prothrombin complex concentrates (PCCs). Anti-Xa levels were collected in 2 patients who had received PCCs before arrival at our ED. Of the patients with anti-Xa levels below 30 ng/mL, none received aPCCs or PCCs after their anti-Xa levels were determined. Anti-Xa assays were used to rule out the presence of FXaIs in 3 patients.

Conclusion

This study illustrates the novel role of anti-Xa levels in managing patients with an emergent need for reversal in the ED. The assay may be used to rule out the presence of oral FXaIs and avoid unnecessary administrations of anticoagulation reversal agents.
Sirt1 and Nrf2: regulation of Leydig cell oxidant/antioxidant intracellular environment and steroid formation†
Authors: Chung Jin-Yong , Chen Haolin , Zirkin Barry
Published: August 2021

Previous studies reported that, with aging, Leydig cell intracellular antioxidants are reduced in concentration and intracellular ROS levels increase, suggesting that oxidant/antioxidant imbalance may contribute to the reduced testosterone production that characterizes the aging cells. As yet, little is known about how the Leydig cell oxidant/antioxidant environment is regulated. Sirt1, an enzyme that deacetylates transcription factors, and the transcription factor Nrf2, have been shown to be associated with cellular response to oxidative stress. We hypothesized that Sirt1 and/or Nrf2 might be involved in regulating the oxidant/antioxidant environment of Leydig cells, and therefore, the testosterone production. We found that Sirt1 and Nrf2 are present in the Leydig cells of Brown Norway rats, though reduced in aged cells. In MA-10 cells in which Sirt1 or Nrf2 were suppressed by nicotinamide (NAM) or ML385, respectively, or in which siRNAs were used for knockdown of Sirt1 or Nrf2, increased ROS levels and decreased progesterone production occurred. In rat Leydig cells, inhibition of Sirt1 by culturing the cells with NAM resulted in increased ROS and reduced testosterone production, and subsequent removal of NAM from the culture medium resulted in increased testosterone production. Activation of rat Leydig cells Sirt1 with honokiol or of Nrf2 with sulforaphane resulted in the maintenance of testosterone production despite the exposure of the cells to oxidizing agent. These results, taken together, suggest that Sirt1 and Nrf2 are involved in maintaining the Leydig cell oxidant/antioxidant environment, and thus in maintaining steroid production.
Multiperspectival Normative Assessment: The Case of Mediated Reactions to Terrorism
Authors: Wessler Hartmut , Althaus Scott L , Chan Chung-hong , Jungblut Marc , Welbers Kasper , van Atteveldt Wouter
Published: August 2021

This article provides a model for how communication phenomena can be normatively assessed using multiple normative perspectives simultaneously. We exemplify the procedure of multiperspectival normative assessment (MNA) using mediated reactions to terrorism as our case in point. We first identify the normative challenges related to the speed and substance of terrorism communication and the ways in which relations of solidarity are communicatively constructed in reacting to terrorism. We link these challenges to four distinct normative theories that prioritize competing values for public discourse (freedom, community values, empowerment of the marginalized or constructive debate). The resulting set of competing normative expectations, which help assess the performance of terrorism communication, are eventually translated into recommendations for professional and non-professional communicators. In conclusion, we show how MNA can help ground empirical scholarship in firmer theoretical foundations while simultaneously demonstrating the usefulness of normative theory in analyzing a wide range of issues.
Theodor Adorno, Paul Lazarsfeld, and the Public Interest Mandate of Early Communications Research, 1935–1941
Authors: Shepperd Josh
Published: August 2021

Through detailed archival analysis of personal letters, this article examines how the “public interest” mandate of the Communications Act of 1934 inspired the formation of the Princeton Radio Research Project (PRRP), and influenced Paul Lazarsfeld’s development of two-step flows and media effects research. Buried in federal records, a post-Act Federal Communications Commission (FCC) Pursuant that mandated analysis of educational broadcasting additionally turns out to be the causative reason that Theodor Adorno was brought to America by the Rockefeller Foundation. Crucial to the intellectual history of media and communication theory, Lazarsfeld invited Adorno not only to develop techniques to inform educational music study, but to strategically formulate advocacy language for the media reform movement to help noncommercial media obtain frequency licenses. The limits and pressures exerted by the FCC Pursuant influenced the trajectory of the PRRP research, and consequently, the methodological investments of Communication Studies.
Role of imaging for diagnosis and management of aortic valve papillary fibroelastoma and cardiac amyloid light chain amyloidosis: a case report
Authors: Dimov Ivan , Meuleman Nathalie , de Cannière Didier , Unger Philippe
Published: August 2021

Background

We report the case of a patient who presented with concomitant aortic valve papillary fibroelastoma (PFE) and cardiac amyloidosis. Although histologically benign, PFE confers an increased thromboembolic risk, and surgical excision is often indicated. However, outcomes of cardiac surgery are poor in patients with cardiac amyloidosis.

Case summary

A 61-year-old man with complaints of dyspnoea and weight loss of 10 kg developing over the past 5 months was evaluated in the cardiology clinic. Echocardiography revealed sessile aortic valve PFE and was also highly suggestive of cardiac amyloidosis. The diagnosis of amyloid light chain amyloidosis secondary to indolent multiple myeloma was eventually confirmed. Therapy with daratumumab, bortezomib, cyclophosphamide, and dexamethasone allowed full remission over a 6-month period and resulted in marked improvement in symptoms and cardiac function as evaluated by global longitudinal strain. Further workup with cerebral magnetic resonance revealed multiple vascular sequelae. Surgical removal of the aortic fibroelastoma with bioprosthetic aortic valve replacement was performed successfully and the patient had an uneventful recovery.

Discussion

Papillary fibroelastoma and cardiac amyloidosis are rare and most likely unrelated entities. Concomitant presentation of both conditions in the same patient presents a unique therapeutic challenge. By allowing cardiac function to be monitored during chemotherapy, speckle-tracking echocardiography can prove instrumental in determining the optimal timing of surgical intervention.
Survey on arterial hypertension management: a report from the ESC Council for Cardiology Practice and the ESC Council on Hypertension
Authors: Mancusi Costantino , de Simone Giovanni , Asteggiano Riccardo , Richter Dimitri , Williams Bryan , Ferrini Marc
Published: August 2021

Aims

To explore the management of hypertensive patients by general cardiologists a few months after the European Society of Cardiology (ESC)–European Society of Hypertension (ESH) Guidelines publication.

Methods and results

A survey based on a 26-point questionnaire was sent to ∼69 000 worldwide ESC members, a few months after the ESC–ESH Guidelines publication. A total of 1458 responses were collected via a web-based form. Among them, 68% were men, 48% were below 45 years old, and 60% were from Europe. Current guidelines have been read, at least partially, by 92.8%. Measurement of blood pressure (BP) is mostly done using the auscultatory method (58.8%) while unattended BP is rarely performed. Different bladder cuffs are not available for different arm circumferences for 27% of responders. Routine workup in hypertensive patients includes more often 12 leads ECG (97.7%) and echocardiography (79.6%). Only 30.9% of responders systematically assess the cardiovascular risk by the SCORE system and orthostatic hypotension is systematically researched by only 39.1%. Respondents consider that BP target of 140/90 mmHg is achievable in 60–80% of patients and 130/80 mmHg in 40–60%. Guidelines are considered too tight to be achievable by 15.6%, while 77.4% consider they are exactly right. Low patient’s compliance, awareness of hypertension (HT) risk, and, at a lower degree, physician inertia, represent the main treatment challenges in reaching BP goals to most respondents, while treatment effectiveness is not in question. The present survey demonstrates specific gaps in HT management that need attention in clinical practice.
Yeast J-protein Sis1 prevents prion toxicity by moderating depletion of prion protein
Authors: Kumar Jyotsna , Reidy Michael , Masison Daniel C
Published: August 2021

[PSI+] is a prion of Saccharomyces cerevisiae Sup35, an essential ribosome release factor. In [PSI+] cells, most Sup35 is sequestered into insoluble amyloid aggregates. Despite this depletion, [PSI+] prions typically affect viability only modestly, so [PSI+] must balance sequestering Sup35 into prions with keeping enough Sup35 functional for normal growth. Sis1 is an essential J-protein regulator of Hsp70 required for the propagation of amyloid-based yeast prions. C-terminally truncated Sis1 (Sis1JGF) supports cell growth in place of wild-type Sis1. Sis1JGF also supports [PSI+] propagation, yet [PSI+] is highly toxic to cells expressing only Sis1JGF. We searched extensively for factors that mitigate the toxicity and identified only Sis1, suggesting Sis1 is uniquely needed to protect from [PSI+] toxicity. We find the C-terminal substrate-binding domain of Sis1 has a critical and transferable activity needed for the protection. In [PSI+] cells that express Sis1JGF in place of Sis1, Sup35 was less soluble and formed visibly larger prion aggregates. Exogenous expression of a truncated Sup35 that cannot incorporate into prions relieved [PSI+] toxicity. Together our data suggest that Sis1 has separable roles in propagating Sup35 prions and in moderating Sup35 aggregation that are crucial to the balance needed for the propagation of what otherwise would be lethal [PSI+] prions.
The SAGA and NuA4 component Tra1 regulates Candida albicans drug resistance and pathogenesis
Authors: Razzaq Iqra , Berg Matthew D , Jiang Yuwei , Genereaux Julie , Uthayakumar Deeva , Kim Grace H , Agyare-Tabbi Michelle , Halder Viola , Brandl Christopher J , Lajoie Patrick , Shapiro Rebecca S
Published: August 2021

Candida albicans is the most common cause of death from fungal infections. The emergence of resistant strains reducing the efficacy of first-line therapy with echinocandins, such as caspofungin calls for the identification of alternative therapeutic strategies. Tra1 is an essential component of the SAGA and NuA4 transcriptional co-activator complexes. As a PIKK family member, Tra1 is characterized by a C-terminal phosphoinositide 3-kinase domain. In Saccharomyces cerevisiae, the assembly and function of SAGA and NuA4 are compromised by a Tra1 variant (Tra1Q3) with three arginine residues in the putative ATP-binding cleft changed to glutamine. Whole transcriptome analysis of the S. cerevisiae tra1Q3 strain highlights Tra1’s role in global transcription, stress response, and cell wall integrity. As a result, tra1Q3 increases susceptibility to multiple stressors, including caspofungin. Moreover, the same tra1Q3 allele in the pathogenic yeast C. albicans causes similar phenotypes, suggesting that Tra1 broadly mediates the antifungal response across yeast species. Transcriptional profiling in C. albicans identified 68 genes that were differentially expressed when the tra1Q3 strain was treated with caspofungin, as compared to gene expression changes induced by either tra1Q3 or caspofungin alone. Included in this set were genes involved in cell wall maintenance, adhesion, and filamentous growth. Indeed, the tra1Q3 allele reduces filamentation and other pathogenesis traits in C. albicans. Thus, Tra1 emerges as a promising therapeutic target for fungal infections.
O-003 The puzzling unknowns of abnormal fertilization and first cleavage
Authors: Racowsky C
Published: August 2021

Abstract text

Fertilization is a critical event in development in that it provides the connection between the gametes and the earliest stages of embryogenesis. Yet, despite the central importance of this process in contributing to embryo developmental fate, clinical embryologists have historically assessed fertilization merely by the number of pronuclei and, if two are present, perhaps, by the presence of two polar bodies. Even though over 20 years ago, time lapse imaging was applied for defining early events of fertilization (Payne et al., 1997), it is only with contemporary time-lapse imaging systems in the last few years that detailed evaluation of spatial and temporal events of fertilization have been described (Iwata & Yasuyuki, 2016; Cottichio et al., 2018). These careful analyses allow us to describe typical and atypical events of fertilization and how they are each associated with timing of the first cleavage division and subsequent embryo development.

In this lecture, we will first describe the fundamental underpinnings of fertilization and highlight the normal events associated with this process. We will then discuss gross morphological abnormalities as visualized by light microscopy and highlight the unknowns associated with these events. Finally, we will focus on time-lapse imaging studies, which have revealed the remarkable spatial and temporal coordination of meiotic resumption, pronuclear dynamics, chromatin organization and cytoplasmic/cortical modifications that occur during fertilization and the implications of aberrations for the first cleavage division.

At the conclusion of this presentation, attendees should be able to: Review the normal events associated with fertilization and the first cleavage division.

1 Describe gross morphological aberrations of these two fundamental processes.

2 Discuss temporal and spatial abnormalities in the coordinated sequence of events that underly these processes.

3 State the potential application of these abnormalities as predictors of abnormal embryo development.

4 Summarize the puzzling unknowns that underly these abnormalities.
O-005 Mullerian anomalies overview
Authors: Prasad S
Published: August 2021

Abstract text

Mullerian Duct Anomalies- An Overview

Prof. Sudha Prasad

President Indian Fertility Society, Director, Matritava Advanced IVF & Training Centre, New Delhi, India

Congenital anomalies of the mullerian duct system is one of the complex disorder encountered in gynecological practice. Mullerian ducts are paired embryological structures which undergo fusion and resorption in utero to form the uterus, fallopian tubes, cervix and upper two-thirds of the vagina. Disruption in the mullerian duct development throughout embryogenesis could result a large spectrum of inherent abnormalities identified as mullerian duct anomalies (MDAs).

There is a wide variation in the prevalence of MDAs across various studies, ranging from 1–10% in the general population to 2–8% among infertile women and 5–30% among women with a history of miscarriage. These discrepancies in the reported prevalence are mainly attributed to lack of a universal classification system.

Different varieties of malformations can occur when this system is not well developed. It ranges from absence of uterus, cervix or vagina, septum/duplication of vagina to of the uterus and vagina to minor uterine cavity abnormalities. Mullerian malformations are frequently associated with abnormalities of the renal and axial skeletal systems. Therefore, on initial examination of MDAs patients, these points should be kept in mind.

Most mullerian duct anomalies (MDAs) are associated with functioning ovaries and age-appropriate external genitalia. These abnormalities are often recognized after the onset of puberty. After the onset of puberty, young women often present to the gynecologist with menstrual disorders. Late presentations include infertility and obstetric complications.

A meta-analysis of nine studies comprising 3805 women with congenital uterine anomalies reviewed the obstetric outcome. The study reported that canalization defects such as septate and partial septate uteri had reduce fertility and increase rates of miscarriage and preterm delivery. None of the unification defects (bicornuate, unicornuate and didelphic uteri) reduce fertility but some are related to miscarriage and prematurity. Arcuate uteri are specifically associated with second-trimester miscarriage. All uterine abnormalities increase the risk of fetal malformation during delivery1.

A retrospective longitudinal study concluded that reproductive performance of the unicornuate and didelphys uteri was poor (20–30% chance of carrying a pregnancy to term), while that of the septate and bicornuate uteri (live birth rate of 62%) was better than expected. The arcuate uterus had no impact on reproductive performance of women2.

Agenesis of uterus and vagina requires surgical techniques, such as the Vecchietti and McIndoe procedures, have enabled many women to have normal sexual relations. Uterine transplant has changed the perspective of all other surgical advances and assisted reproductive technologies to improve fertility and obstetric outcomes3, 4,5.
O-008 Improving outcomes in women with Mullerian anomalies
Authors: Malhotra J , Malhotra N , Malhotra N
Published: August 2021

Abstract text

Mullerian Anomalies are present in approximately 5% to 7% of the general population and the incidence is a little more in infertile and recurrent miscarriage women. Most of the recent studies have reported that the obstetric outcome is compromised in this group with greater risk of infertility, recurrent pregnancy loss, intrauterine growth retardation, preterm birth and many other obstetric complications, which may be individually related to the different types of Mullerian Anomalies. In this presentation, We are going to discuss on how the outcomes are different in the various Mullerian Anomalies depending upon the degree of the defects related to different complications with more profound defects. We will also discuss on how to optimize the pregnancy outcomes with various interventions and what the literature review supports.

Trial registration number

Study funding

Funding source
P-523 Whole-chromosome aneuploidies revealed by transcriptome of trophectoderm biopsied from human pre-implantation blastocyst
Authors: Song L , Yanwen X , Bing C , Yan X , Xiu Y , Canquan Z
Published: August 2021

Study question

Whether mRNA transcriptome of biopsied trophectoderm (TE) in human pre-implantation blastocyst can predict embryo karyotype?

Summary answer

mRNA transcriptome of biopsied TE can precisely predict whole-chromosome aneuploidies but not mosaicism or segmental aneuploidies.

What is known already

Karyotype of human pre-implantation blastocyst is well recognized by PGT-A. However, genome can’t demonstrate gene expression level which might infer the development potential of euploidy. Transcriptome of blastocyst by singe-cell RNA-seq has revealed the lineage segregation of human pre-implantation blastocyst. It is not known whether transcriptome of biopsied TE used in PGT-A can infer the karyotype of human pre-implantation blastocyst.

Study design, size, duration

A total of 74 TE samples were biopsied from 26 blastocysts which were donated from patients who underwent PGT at our Reproductive Medicine Center. All of these embryos have been previously diagnosed as aneuploidies (n = 19) or euploidies (n = 7) with monogenic disorder.

Participants/materials, setting, methods

The DNA and mRNA of all biopsied TEs were separated independently using a modified oligo-dT bead capture, followed by PGT-A of DNA and smart2-sequencing of mRNA (G&T-seq). Karyotype of biopsied TEs were confirmed with PGT-A performed in MiSeq system (Illumina) in our PGT laboratory with the use of next-generation sequencing. Data of transcriptome was analyzed using Rstudio and R package InferCNV to predict aneuploidies by referring to euploidies which were inferred with corresponding PGT-A results.

Main results and the role of chance

In human pre-implantation blastocyst, all whole-chromosome aneuploidies could be inferred by transcriptome of biopsied TE, which were consistent with PGT-A result. But chromosomal mosaicism or segmental aneuploidies were hard to be predicted precisely by transcriptome of TE.

Limitations, reasons for caution

The main limitation of this study lies in the inability to retrieve the exact copy number variations from mRNA transcription. Gene expression is in a great imbalance in such an early development of human pre-implantation blastocyst.

Wider implications of the findings

Our data suggest that mRNA transcriptome is enough for prediction of whole-chromosome aneuploidies. The method and value for predicting mosaicism and segmental aneuploidies by transcriptome should be further investigated.

Trial registration number

not applicable
O-034 Infertility treatment law making in Europe: the clash of knowledge, ethics and business
Authors: Wilinska-Zelek A
Published: August 2021

Abstract text

Infertility treatment law making in Europe: the clash of knowledge, ethics and business

Today, there is no common European set of rules for Assisted Reproduction Technology (ART). ART is now controlled by legislation in almost all European countries, substantial variations exist within the detail of that legislation.

Main legal differences between countries relate to: embryo selection, particularly by genetic screening, embryo freezing and embryo transfer, preimplantation genetic diagnosis (PGD), oocyte donation, anonymity of gamete donors, surrogacy, patient eligibility criteria (eg, sexual orientation, age), reimbursement and state funding.

The most complete survey ever of the ART legal and funding framework of 43 European countries was published in the ESHRE medical journal Human Reproduction Open: Calhaz-Jorge C, De Geyter C, Kupka MS, et al. Survey on ART and IUI: Legislation, regulation, funding and registries in European countries. Hum Reprod Open 2020; doi:10.1093/hropen/hoz044.

Unfortunately, changes of legislation are so dynamic that much of the information in this article is no longer up-to-date.

Lawyers observe that one of the most important rule of law “When the Law ceases to reflect the realities of Life, it is the Law that will Change” does not work in ART. In regard to this matter dominant rule is: “The Law will change only when it ceases to reflect the government’s point of view and lobbyists’ needs”. Modern medical knowledge and the society’s needs are often not the main concern during the law making discussion.

The speech discusses the issues related to infertility treatment law making in Europe with a focus of the problem that modern medical knowledge in this process is not taken into account at all. The author diagnoses numerous problem related to determining the border between medical knowledge, ethics and business in law making process.

The observed problems will be discussed on selected examples (from Poland, Greece and the United Kingdom) during presentation at the ESHRE on-line 37th Annual Meeting.
O-035 Searching for the perfect country - mapping out differences in fertility treatments and access to treatments across Europe
Authors: Bye K
Published: August 2021

Abstract text

Fertility Europe has established a working group that is examining secondary data on legislation, regulation and funding of fertility treatment across Europe. The data has been mapped in order to easily visualize the “perfect country” in terms of fertility treatments[Vi1] . The map will be updated every two years in order to show progress towards more countries reaching the status of “perfect country”. As the map provides a clear picture on the differences in access to treatments[Vi2] across Europe, it is expected to be a useful advocacy tool for patient[Vi3] associations working to influence the current treatment situation in their country. This talk focuses on the work that has been done by the Fertility Europe working group to date, to create the map of the “perfect country”, and the possibilities that such a map represents from a patient advocacy perspective.

treatmentS [Vi1] [Vi1]

treatmentS [Vi2] [Vi2]

patient associations’ [Vi3] [Vi3]
O-039 Mitochondrial ATP generation in mammalian eggs and Ca2+ signaling
Authors: Swann K
Published: August 2021

Abstract text

In metaphase II arrested mammalian oocytes (eggs) and cleavage stage embryos the mitochondria are responsible for nearly all ATP production because glycolysis is inactivated. Luciferase assays show that ATP levels in eggs are strictly dependent upon pyruvate and fatty acid oxidation. The level of ATP in eggs appears to be maximal in conventional medium because the addition of extra mitochondrial substrates to eggs does not increase cytosolic ATP. The only clear elevation of ATP is seen at fertilization and is associated with sperm induced Ca2+ oscillations. Our recent findings suggest that the level of ATP modulates events at fertilization.

At fertilization, the egg is activated by sperm derived PLCzeta which triggers a series of Ca2+ oscillations, with each Ca2+ release event causes by inositol trisphosphate (InsP3). Previous studies have shown that mouse eggs are more sensitive to PLCzeta, and generate higher frequency Ca2+ oscillations, than human eggs. Mouse eggs also generate Ca2+ oscillations and activate in response to Sr2+ that directly stimulates InsP3 receptors. In contrast, human eggs that contain the same type of InsP3 receptors do not generate Ca2+ oscillations in response to Sr2+.

The difference in sensitivity of Ca2+ release between species can be explained by the fact that mouse eggs are about ten times more sensitive to InsP3 than human eggs. The reason for this difference appears to be due to ATP. The ATP level in unfertilized mouse eggs is about twice that in human eggs. Furthermore, the ability of mouse eggs to Sr2+ medium can be abolished by removing the mitochondrial substrate pyruvate, which reduces the ATP level. Adding back pyruvate to such eggs restores ATP levels promotes Sr2+ induced Ca2+ levels in mouse eggs. These data suggest that the level of ATP, possibly as ATP4-, modulates the sensitivity of the InsP3 receptor and the ability of eggs to generate Ca2+ oscillations. The level of cytosolic ATP may represent a significant ‘egg factor’ in determining the success of fertilization in humans. Enhancing mitochondrial ATP production could be useful in improving activation and embryo development after fertilization, or after artificial egg activation.

References:

Dumollard et al. (2009) Seminar in Cell and Developmental Biology 20, 346-353

Campbell and Swann (2006) Developmental Biology 298, 225-233

Storey et al. (2021) Molecular Human Reproduction 27, gaaa086
O-044 Chinese Society of Reproductive Medicine 2018 annual report on ART
Authors: Deng C
Published: August 2021

Abstract text

Objective

To analysis the Chinese ART data in 2018 to provide evidence for utilization of various ART.

Methods

The data of ART of 263 Reproductive Centers in the mainland of China in 2018 were collected by CSRM ART Data Reporting System. A cross-sectional survey of the use of ART technology was performed.

Results

In 2018, the CSRM data reporting system reported 105 610 AID/AIH cycles, 323 938 oocyte retrieval cycles, 147 129 fresh embryo transfer cycles, 254 012 frozen-thawed embryo transfer (FET) cycles, and 204 688 newborn . The patient's age was mainly concentrated in the group <35 years old, accounting for 63.75%. The pregnancy rate and live birth rate of retrieval cycles were 52.49% and 42.23% respectively. The pregnancy rate and live birth rate of FET cycles were 48.71% and 37.68% respectively. Among ART complications, the incidence of moderate to severe OHSS was 1.42%, 0.03% postoperative bleeding, 0.01% postoperative pelvic infection, and 0.04% the other complications. The incidence of birth defects of IVF was 0.87%.

Conclusions

This study uses "CSRM data reporting system" data to describe and analyze the current status of ART, basically consistent with the comparison in 2016 and 2017 that most cycles with good outcomes. However, no clear conclusions have been drawn on the changes of PGD/PGS cycle, all-freeze cycle and comprehensive analysis should be conducted by combining with laboratory data.

Trial registration number:

Study funding:

Funding source:
O-045 Synthetic human embryo-like structures: a new paradigm for human embryology
Authors: Fu J
Published: August 2021

Abstract text

Early human development remains mysterious and very difficult to study. Recent advances in mammalian embryology, stem cell biology, organoid technology, and bioengineering have contributed to a significant interest in bottom-up, synthetic stem cell-derived models of human development (or embryoids). The controllability and reproducibility of human embryoids coupled with the ease of genetically modifying stem cell lines, the ability to manipulate culture conditions and the simplicity of live imaging make them robust and attractive systems to disentangle cellular behaviors and signaling interactions that drive human embryogenesis. In this talk, I will describe our effort in using human pluripotent stem cells (hPSCs) to develop tractable experimental models of the peri-implantation embryonic development and neurulation. The peri-implantation human embryoids developed by us recapitulate key early post-implantation developmental landmarks successively, including pro-amniotic cavity formation, amniotic ectoderm-epiblast patterning, primordial germ cell specification, and development of the primitive streak with controlled anteroposterior polarity. I will further discuss an hPSC-based neuroectoderm patterning model to recapitulate the formation of the neural plate and another patterned neural tube model with fully defined anterior-posterior and dorsal-ventral axes.
O-053 Early life factors that may influence adult male reproductive
Authors: Hart R
Published: August 2021

Abstract text

This presentation will provide a brief overview of testicular development and will describe a critical period of development at approximately 8-14 weeks of gestation, when the testicle may be vulnerable to external influences, potentially having a negative effect on subsequent development. The talk with then describe the testicular dysgenesis syndrome hypothesis, proposed by Niels Skakkebæk, and using the presenters work within the Western Australian (Raine) Cohort will go onto demonstrate how early life exposures may influence mature testicular function. Worryingly, the presentation will describe how adolescent features of early metabolic disturbance within the Raine Cohort are already having a determinantal effect on the reproductive function of these men in late adolescence, many years before the majority are seeking paternity.