bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of a convolutional neural network for classifying microvessels of superficial esophageal squamous cell carcinomas
Authors: Uema Ryotaro , Hayashi Yoshito , Tashiro Taku , Saiki Hirotsugu , Kato Minoru , Amano Takahiro , Tani Mizuki , Yoshihara Takeo , Inoue Takanori , Kimura Keiichi , Iwatani Shuko , Sakatani Akihiko , Yoshii Shunsuke , Tsujii Yoshiki , Shinzaki Shinichiro , Iijima Hideki , Takehara Tetsuo
Published: March 2021

Background and Aim

The morphological diagnosis of microvessels on the surface of superficial esophageal squamous cell carcinomas using magnifying endoscopy with narrow‐band imaging is widely used in clinical practice. Nevertheless, inconsistency, even among experts, remains a problem. We constructed a convolutional neural network‐based computer‐aided diagnosis system to classify the microvessels of superficial esophageal squamous cell carcinomas and evaluated its diagnostic performance.

Methods

In this retrospective study, a cropped magnifying endoscopy with narrow‐band images from superficial esophageal squamous cell carcinoma lesions was used as the dataset. All images were assessed by three experts, and classified into three classes, Type B1, B2, and B3, based on the Japan Esophagus Society classification. The dataset was divided into training and validation datasets. A convolutional neural network model (ResNeXt‐101) was trained and tuned with the training dataset. To evaluate diagnostic accuracy, the validation dataset was assessed by the computer‐aided diagnosis system and eight endoscopists.

Results

In total, 1777 and 747 cropped images (total, 393 lesions) were included in the training and validation datasets, respectively. The diagnosis system took 20.3 s to evaluate the 747 images in the validation dataset. The microvessel classification accuracy of the computer‐aided diagnosis system was 84.2%, which was higher than the average of the eight endoscopists (77.8%, P < 0.001). The area under the receiver operating characteristic curves for diagnosing Type B1, B2, and B3 vessels were 0.969, 0.948, and 0.973, respectively.

Conclusions

The computer‐aided diagnosis system showed remarkable performance in the classification of microvessels on superficial esophageal squamous cell carcinomas.
Advances in understanding meso‐cortico‐limbic‐striatal systems mediating risky reward seeking
Authors: Piantadosi Patrick T. , Halladay Lindsay R. , Radke Anna K. , Holmes Andrew
Published: March 2021

The risk of an aversive consequence occurring as the result of a reward‐seeking action can have a profound effect on subsequent behavior. Such aversive events can be described as punishers, as they decrease the probability that the same action will be produced again in the future and increase the exploration of less risky alternatives. Punishment can involve the omission of an expected rewarding event (“negative” punishment) or the addition of an unpleasant event (“positive” punishment). Although many individuals adaptively navigate situations associated with the risk of negative or positive punishment, those suffering from substance use disorders or behavioral addictions tend to be less able to curtail addictive behaviors despite the aversive consequences associated with them. Here, we discuss the psychological processes underpinning reward seeking despite the risk of negative and positive punishment and consider how behavioral assays in animals have been employed to provide insights into the neural mechanisms underlying addictive disorders. We then review the critical contributions of dopamine signaling to punishment learning and risky reward seeking, and address the roles of interconnected ventral striatal, cortical, and amygdala regions to these processes. We conclude by discussing the ample opportunities for future study to clarify critical gaps in the literature, particularly as related to delineating neural contributions to distinct phases of the risky decision‐making process.

image
Neurobiology of alcohol seeking behavior
Authors: Domi Esi , Domi Ana , Adermark Louise , Heilig Markus , Augier Eric
Published: March 2021

Alcohol addiction is a chronic relapsing brain disease characterized by an impaired ability to stop or control alcohol use despite adverse consequences. A main challenge of addiction treatment is to prevent relapse, which occurs in more than >50% of newly abstinent patients with alcohol disorder within 3 months. In people suffering from alcohol addiction, stressful events, drug‐associated cues and contexts, or re‐exposure to a small amount of alcohol trigger a chain of behaviors that frequently culminates in relapse. In this review, we first present the preclinical models that were developed for the study of alcohol seeking behavior, namely the reinstatement model of alcohol relapse and compulsive alcohol seeking under a chained schedule of reinforcement. We then provide an overview of the neurobiological findings obtained using these animal models, focusing on the role of opioids systems, corticotropin‐release hormone and neurokinins, followed by dopaminergic, glutamatergic, and GABAergic neurotransmissions in alcohol seeking behavior.

image
Expression and significance of microRNA‐126 and VCAM‐1 in placental tissues of women with early‐onset preeclampsia
Authors: Liu Beibei , Liu Ling , Cui Shihong , Qi Yue , Wang Tiantian
Published: March 2021

Objective

To investigate the expression of microRNA‐126 (miR‐126) and vascular endothelial cell adhesion molecule‐1 (VCAM‐1) in the placental tissues of women with early‐onset preeclampsia (EOPE) and their effects on trophoblast invasion.

Materials and Methods

The placental tissues of 30 pregnant women with EOPE who delivered in the Third Affiliated Hospital of Zhengzhou University from November 2019 to May 2020 were selected as the preeclampsia (PE) group, and the placental tissues of 30 healthy pregnant women with normal prenatal examination were selected as the normal group. Immunohistochemistry was used to localize VCAM‐1 in placental tissues，the expression of miR‐126 and VCAM‐1 in placenta tissues of two groups and HTR‐8/SVneo cells transfected with miR‐126 were detected by real‐time polymerase chain reaction (RT‐PCR) and Western blot, and the correlation between them was analyzed. The invasion ability of cells transfected with miR‐126 was observed by Transwell invasion test.

Results

Compared with the normal group, the expression of miR‐126 was higher and VCAM‐1 was lower in the placental tissues of the PE group, and the difference were statistically significant (p < 0.01). Moreover, VCAM‐1 was negatively correlated with the expression of miR‐126 (r = −0.391, p < 0.05). In vitro experiment, the expression level of VCAM‐1 in miR‐126 mimics transfection group was decreased, and the expression level of VCAM‐1 in miR‐126 inhibitor transfection group was increased; the invasion ability of HTR‐8/SVneo cells transfected with miR‐126 mimics was decreased, and the invasion ability of HTR‐8/SVneo cells transfected with miR‐126 inhibitor was enhanced.

Conclusion

There was a negative correlation between the expression of miR‐126 and VCAM‐1 in EOPE.MiR‐126 and VCAM‐1 may participate in the occurrence and development of EOPE by affecting the invasion ability of trophoblast cells.
Educational and Type of Day Differences in Mothers' Time Availability for Child Care and Housework
Authors: Gupta Sanjiv , Sayer Liana C. , Pearlman Jessica
Published: March 2021

Objective

The authors analyzed variation by education and type of day in the “time availability” association between U.S. mothers' paid work hours and housework and child care, types of work that vary by their urgency, affect, and symbolic meaning.

Background

Research shows a stronger negative association of women's work hours with housework than child care, and interprets this as evidence to show mothers prioritize child care over housework. The authors extend this work by determining if associations of work hours with partnered mothers' housework and child care differ by college education and type of day.

Method

The authors used ordinary least squares regression on weekend and weekday time diaries of partnered mothers aged 18–65 (N = 22,816) from the 2003–2018 American Time Use Survey (
https://timeuse.ipums.org/).

Results

Authors found negative associations of mothers' work hours with weekday housework and child care. They found a negative association of college degrees with weekday housework but a positive association with child care that attenuates at longer work hours. The negative work hour association, and the education gap in predicted child care time, persisted on weekends. Work hour and education associations with weekend housework were positive, and the education gap widened at longer work hours.

Conclusion

The “time availability” constraint of employment hours applies to child care and housework, even among mothers with college degrees. Education differences in unpaid work, particularly child care, are most evident on weekends.
Cortisol levels in the peri‐implant sulcular fluid among patients with and without peri‐implantitis
Authors: Alresayes Saad , Al‐Askar Mansour , Mokeem Sameer A , Javed Fawad , Vohra Fahim , Abduljabbar Tariq
Published: March 2021

Background and Objective

Cortisol levels remain uninvestigated in peri‐implant sulcular fluid (PISF) of patients with and without peri‐implantitis. The present investigation investigated levels of cortisol in PISF among controls (individuals without peri‐implantitis) and patients with peri‐implantitis.

Methods

The patient population comprised of participants with and without peri‐implantitis (groups 1 and 2, respectively). Demographic information and data related to implant characteristics was recorded. Peri‐implant radiographic (crestal bone loss [CBL]) and clinical (modified plaque and bleeding on probing indices [PI and BOP], and probing depth [PD]) and parameters were assessed. In all patients, levels of cortisol were measured in the PISF, which was collected using standard methods. Data normality and group comparisons were assessed, and multiple logistic regression was performed. Probability values less than 0.01 were nominated as being significant.

Results

Eighty‐eight individuals (44 and 44 in groups 1 and 2, correspondingly) were included. In group 1, 24 and 20 participants were males and females, and there were 22 and 22 males and females in group 2. Mean ages were analogous in both groups. Peri‐implant BOP (p < .001); CBL (p < .001); PI (p < .001); and PD (p < .001) were higher among patients in group 1 compared with group 2. The volume of PISF (p < .001) collected and its concentrations of cortisol (p < .001) were significantly higher among patients in group 1 compared with group 2. Regression analysis showed that CBL and PD directly correlated with increased PISF levels of cortisol among participants with peri‐implantitis.

Conclusion

Within the limits of the present study, it remains debatable whether or not PISF cortisol levels vary among patients with and without peri‐implantitis. Further studies are needed to evaluate the role of PISF levels of cortisol in the diagnosis of peri‐implantitis.
Worlds without nation‐states: Five scenarios for the very long term
Authors: Wimmer Andreas
Published: March 2021

This article develops five scenarios of how human society could be politically organized in 300 years, after nation‐states have dissolved and nationalism as their foundational ideology has dissipated. The scenarios are based on sociological theories on how functional integration and differentiation shape the evolution of modern societies. All scenarios therefore assume that the basic characteristics of modernity will persist and explore only a small area of the theoretically infinite space of long‐term futures. Also for the sake of manageability, the author envisions only one technological and economic basis for future political developments, which in turn will be constrained by the need to fulfil three basic functions: to provide public goods, collective defence and a political decision‐making mechanism. The five scenarios differ, however, in whether these functions are assumed by states, how large these will be and whether their boundaries align with cultural difference. The author thus arrives at an anarchic scenario without any states, a scenario with a thousand or more mini‐states based on shared cultural identities, an imperial scenario with a few states each claiming to represent an entire civilization, a world with culturally heterogenous and highly efficient Continental states and finally a world state.
Plant‐centred sampling estimates higher beta diversity of interactions than pollinator‐based sampling across habitats
Authors: Souza Camila S. , Maruyama Pietro K. , Santos Karen C. B. S. , Varassin Isabela G. , Gross Caroline L. , Araujo Andréa C.
Published: March 2021

When describing plant–animal interaction networks, sampling can be performed using plant‐ or animal‐centred approaches. Despite known effects of sampling on network structure, how samplings affect the estimates of interaction β‐diversity across networks is still unresolved.

We investigated how the sampling method affects the assessment of β‐diversity of interactions, turnover and rewiring. We contrasted plant‐ and animal‐centred sampling methods applied to pollination networks across habitats in a heterogeneous tropical landscape, the Pantanal Wetlands. We also asked whether plant traits influence the difference in interaction specialization according to sampling.

Plant‐centred networks resulted in higher β‐diversity of interactions in space than animal‐centred networks. Turnover explained most of the β‐diversity in both methods, but rewiring was proportionately more important when using the animal‐centred method. While the plant‐centred method indicated lower network modularity and specialization, floral traits modulated the effects of the sampling method on species‐level network metrics.

Combining animal‐ and plant‐centred approaches returned intermediate values for β‐diversity of interactions and network metrics. Distinct methods may also be better suited for answering questions at different scales. Our results point out that the method choice, or combination of methods, should always reflect the appropriate scale of the factors determining the interactions being investigated.
Genome‐wide association studies of exacerbations in children using long‐acting beta2‐agonists
Authors: Slob Elise M. A. , Richards Levi B. , Vijverberg Susanne J. H. , Longo Cristina , Koppelman Gerard H. , Pijnenburg Mariëlle W. H. , Bel Elisabeth H. D. , Neerincx Anne H. , Herrera Luis Esther , Perez‐Garcia Javier , Tim Chew Fook , Yie Sio Yang , Andiappan Anand K. , Turner Steve W. , Mukhopadhyay Somnath , Palmer Colin N. A. , Hawcutt Daniel , Jorgensen Andrea L. , Burchard Esteban G. , Hernandez‐Pacheco Natalia , Pino‐Yanes Maria , Maitland‐van der Zee Anke H.
Published: March 2021

Background

Some children with asthma experience exacerbations despite long‐acting beta2‐agonist (LABA) treatment. While this variability is partly caused by genetic variation, no genome‐wide study until now has investigated which genetic factors associated with risk of exacerbations despite LABA use in children with asthma. We aimed to assess whether genetic variation was associated with exacerbations in children treated with LABA from a global consortium.

Methods

A meta‐analysis of genome‐wide association studies (meta‐GWAS) was performed in 1,425 children and young adults with asthma (age 6‐21 years) with reported regular use of LABA from six studies within the PiCA consortium using a random effects model. The primary outcome of each study was defined as any exacerbation within the past 6 or 12 months, including at least one of the following: 1) hospital admissions for asthma, 2) a course of oral corticosteroids or 3) emergency room visits because of asthma.

Results

Genome‐wide association results for a total of 82 996 common single nucleotide polymorphisms (SNPs, MAF ≥1%) with high imputation quality were meta‐analysed. Eight independent variants were suggestively (P‐value threshold ≤5 × 10−6) associated with exacerbations despite LABA use.

Conclusion

No strong effects of single nucleotide polymorphisms (SNPs) on exacerbations during LABA use were identified. We identified two loci (TBX3 and EPHA7) that were previously implicated in the response to short‐acting beta2‐agonists (SABA). These loci merit further investigation in response to LABA and SABA use.
Predictive value of coagulation profiles for both initial and repeated immunoglobulin resistance in Kawasaki disease: A prospective cohort study
Authors: Shao Shuran , Yang Lixia , Liu Xiaoliang , Liu Lei , Wu Mei , Deng Yuxin , Duan Hongyu , Li Yifei , Hua Yimin , Luo Lili , Zhou Kaiyu , Wang Chuan
Published: March 2021

Background

Intravenous immunoglobulin (IVIG) resistance prediction remains substantial in Kawasaki disease (KD), with limited data on the predictive value of coagulation profile for IVIG resistance, particularly for repeated IVIG resistance. Therefore, the aim of our study was to testify the predictive validity of coagulation profile for both initial IVIG resistance and repeated IVIG resistance in KD.

Methods

A total of 385 KD patients were prospectively recruited between April 2015 and May 2019. Coagulation and other profiles were evaluated between the IVIG‐responsive and IVIG‐resistant groups. Multivariate logistic regression analysis was applied to determine the association between coagulation profiles and IVIG resistance. ROC curves analysis was further performed to assess the validity of coagulation profiles in predicting both initial IVIG resistance and repeated IVIG resistance.

Results

Prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), fibrinogen degradation products (FDPs), and D‐dimer were significantly increased in the initial IVIG‐resistant group with antithrombin III (ATIII) and thrombin time (TT) significantly reduced. Meanwhile, ATIII was declined markedly in repeated IVIG‐resistant patients. Multivariate logistic regression analysis showed that PT, APTT, D‐dimer, and ATIII were independent risk factors for predicting initial IVIG resistance and ATIII for predicting repeated IVIG‐resistant patients with KD. PT, APTT, D‐dimer, and ATIII cutoff values of 13.95 s, 41.15 s, 1.48 mg/L, and 89.5% yielded sensitivities of 73%, 32%, 71%, and 81%, and specificities of 55%, 88%, 62%, and 51% for predicting initial IVIG resistance, respectively. The cutoff value of ATIII for predicting repeated IVIG resistance was 68.5%, with sensitivity of 71% and specificity of 55%.

Conclusions

KD patients who have hypercoagulation during the acute phase might be at higher risk of developing IVIG resistance.
Low CD4 count may be a risk factor for non‐tuberculous mycobacteria infection in pediatric hematopoietic cell transplant recipients
Authors: Wobma Holly , Chang Alicia K. , Jin Zhezhen , Baker Courtney , Garvin James , George Diane , Satwani Prakash , Foca Marc , Bhatia Monica
Published: March 2021

Background

HCT leaves patients in a relative state of immune deficiency both during their initial transplant admission and for several years following discharge. NTM are generally harmless colonizers of the outside environment, but for immunocompromised patients, they can cause significant disease due to a paucity of T‐cell defense. While routine prophylaxis against NTM is recommended for patients with low CD4 counts in certain clinical settings (eg, AIDS), this is not yet established for HCT patients despite their higher risk.

Methods

Here we build upon our prior work to determine risk factors for NTM in pediatric HCT patients by comparing NTM patient characteristics to matched HCT controls.

Results

We followed 272 patients across a 13‐year time period, with 11 cases of NTM. Patients with NTM had a significantly lower CD4 count at Day 365 than matched HCT controls (105.5 ± 97.0 cells/µl vs. 856.2 ± 446.1 cells/µl, respectively; p = .001). No other potential risk factors (eg, CMV, GvHD, disease type) were found to be statistically significant, including use of T‐cell depleting agents. This is consistent with an average diagnosis of NTM at Day +323 (ie, outside immediate post‐transplant period). All‐cause mortality was similar between NTM and control HCT groups, with an NTM attributable mortality of <10%.

Conclusion

Since reduced CD4 counts are associated with NTM, and cost and morbidity are high, azithromycin prophylaxis for CD4 count <200 cells/µl in high‐risk patients should be considered.
Factors associated with long‐term graft survival in pediatric kidney transplant recipients
Authors: Anand Adrish , Malik Tahir H. , Dunson Jordan , McDonald Malcolm F. , Christmann Caroline R. , Galvan Nhu Thao Nguyen , O’Mahony Christine , Goss John A. , Srivaths Poyyapakkam R. , Brewer Eileen D. , Rana Abbas
Published: March 2021

Pediatric kidney transplant recipients generally have good outcomes post‐transplantation. However, the younger age and longer life span after transplantation in the pediatric population make understanding the multifactorial nature of long‐term graft survival critical. This investigation analyzes factors associated with 10‐year survival to identify areas for improvement in patient care. Kaplan‐Meier with log‐rank test and univariable and multivariable logistic regression methods were used to retrospectively analyze 7785 kidney transplant recipients under the age of 18 years from January 1, 1998, until March 9, 2008, using United Network for Organ Sharing (UNOS) data. Our end‐point was death‐censored 10‐year graft survival after excluding recipients whose grafts failed within one year of transplant. Recipients aged 5–18 years had lower 10‐year graft survival, which worsened as age increased: 5–9 years (OR: 0.66; CI: 0.52–0.83), 10–14 years (OR: 0.43; CI: 0.33–0.55), and 15–18 years (OR: 0.34; CI: 0.26–0.44). Recipient African American ethnicity (OR: 0.67; CI: 0.58–0.78) and Hispanic donor ethnicity (OR: 0.82; CI: 0.72–0.94) had worse outcomes than other donor and recipient ethnicities, as did patients on dialysis at the time of transplant (OR: 0.82; CI: 0.73–0.91). Recipient private insurance status (OR: 1.35; CI: 1.22–1.50) was protective for 10‐year graft survival. By establishing the role of age, race, and insurance status on long‐term graft survival, we hope to guide clinicians in identifying patients at high risk for graft failure. This study highlights the need for increased allocation of resources and medical care to reduce the disparity in outcomes for certain patient populations.
Cascade Submodular Maximization: Question Selection and Sequencing in Online Personality Quiz
Authors: Tang Shaojie , Yuan Jing
Published: March 2021

Personality quiz is a powerful tool that enables costumer segmentation by actively asking them questions, and marketers are using it as an effective method of generating leads and increasing e‐commerce sales. We study the problem of how to select and sequence a group of quiz questions so as to optimize the quality of customer segmentation. We assume that the customer will sequentially scan the list of questions. After reading a question, the customer makes two, possibly correlated, random decisions: (i) she first decides whether to answer this question or not, and then (ii) decides whether to continue reading the next question or not. We further assume that the utility of questions that have been answered can be captured by a monotone and submodular function. In general, our problem falls into the category of non‐adaptive active learning‐based customer profiling. Note that under our model, the probability of a question being answered depends on the location of that question, as well as the set of other questions placed ahead of that question, this makes our problem fundamentally different from existing studies on submodular optimization. We develop a series of question selection and sequencing strategies with provable performance bound. Although we focus on the application of quiz design in this study, our results apply to a broad range of applications, including assortment optimization with position bias effect.
Eight Democratic Parties in China
Authors: Xiaoyi Huang
Published: March 2021

China has eight democratic parties which established cooperative relations with the CPC. All the democratic parties earnestly performed the functions of participating in and deliberating on state affairs and exercising democratic supervision in China’s political life. Their participation in state affairs under the leadership of the CPC is a major indication of people's democracy. They are of great importance to enhance and develop the multi-party cooperation and political consultation system under the leadership of the CPC. This paper introduces the establishing time, the mainly component members, the founding background, the history evolution and the outstanding contributions of China’s eight democratic parties.
Entre añoranzas, anhelos e incertidumbres: relatos de adultos mayores del barrio Juan XXIII (Bogotá)
Authors: González-Romero Nadya , Mesa-Hoyos Tatiana , Molina Ríos Juliana Angélica , Carbonell Blanco Olga Alicia , Menéndez-Echavarría Alfredo Luis
Published: March 2021

Entre añoranzas, anhelos e incertidumbres surge de una experiencia de indagación narrativa y creativa, que se pregunta por las formas en las que los seres humanos le dan sentido a su existencia y generan aprendizajes profundos en su vida cotidiana. Este libro está compuesto por cinco relatos, que son producto de una serie de conversaciones sobre las vivencias de algunos adultos mayores, que, siendo niños, poblaron parte de los cerros orientales de la ciudad de Bogotá y participaron en la creación y fundación del barrio Juan XXIII, en la localidad de Chapinero. Los relatos de estas personas, que se conectan entre sí, son narraciones espontáneas que se articulan en tres ejes: sus añoranzas por un pasado en el que ellos eran felices, a pesar de las limitaciones económicas y las adversidades; sus anhelos frente a la conciencia de sus pérdidas y vulnerabilidades actuales; y sus incertidumbres ante su futuro, el de sus hijos y sus nietos, quienes fluctúan entre la esperanza y la desesperación. Sus historias personales revelan una parte de la realidad de todo un país marcado por la violencia, la pobreza y la desatención estatal, pero también por la fuerza, la perseverancia y el valor de personas que han construido un espacio comunitario propio.
The Initiation and Propagation of the Plastic Zone in a Tension Bar of Mild Steel as Influenced by the Speed of Stretching and Rigidity of Testing Machine
Authors: Miklowitz Julius
Published: March 2021

The results of several tension tests with round and flat bars of mild steel and iron, under the influence of variations in speed of stretching and testing-machine rigidity, are presented. The emphasis in this work has been placed upon explaining the yield-point phenomena, as viewed externally on a stress-strain diagram, by the observations made and data taken on the internal localized yielding, as presented by the test piece. The study has been focused on the initiation of the plastic zone and the propagation of the boundaries of this zone, sometimes called the plastic working lengths, along the length of the tensile specimen.
The Flow of Metals Through Tools of Circular Contour
Authors: Sachs G. , Klingler L. J.
Published: March 2021

In a large variety of commercial forming processes, the metal flows through a gap formed by the surfaces of parallel cylinders. One of these processes is rolling, which has been investigated previously for certain boundary conditions. This analysis has been extended to cover all possible variations.
The Mobility Method Applied to Mechanical Wave Filters With Inductive Coupling
Authors: Winzer Alice
Published: March 2021

This paper describes a new analysis of mechanical elements connected by inductive coupling as contrasted to series or parallel connections. The mobility method as applied to mechanical wave filters has been discussed before (1). In connection with the high-pass filter, the impossibility of putting masses in series arises. By use of the technique given in the following, high-pass filters may be constructed without any difficulty and, also, all other types of filters may be obtained.
Camptograms for Beams in Compression
Authors: Rojansky V. , Beth R. A.
Published: March 2021

Under the usual assumption that the square of the slope of the beam may be neglected compared to unity, the authors show that if the bending moment M is used as ordinate and a quantity proportional to dM/dx as abscissa, then the curve representing an axially compressed uniform beam carrying a uniformly distributed transverse load is a circular arc or a sequence of circular arcs. This result leads to a graphical method for evaluating bending moment. The procedure is illustrated by examples which include external torques, concentrated transverse loads, built-in ends, stepwise variation of distributed load, stepwise variation of flexural rigidity, and a protruding end. The diagrams, named “camptograms,” are simpler to draw and to interpret than the polar diagrams currently used for the same purpose. The construction of camptograms representing the slope and the deflection of the beam is outlined.
A New Fatigue Strength - Damping Criterion for the Design of Resonant Members
Authors: Marin Joseph , Stulen F. B.
Published: March 2021

In the selection of materials for machine and structural parts subjected to vibrations it is common practice to consider the fatigue strength of materials. In some cases the damping constant of the material may be considered in a qualitative manner. A theoretical analysis is given in this paper to show that the load resistance of resonant members is a function not only of the fatigue strength but also of the damping constant and modulus of elasticity of the material. Test data on various materials are presented to show that the load resistance of a vibrating member may be appreciably changed by a correct selection of the material when this new design criterion is used. Fatigue strength - damping design criteria are presented in this paper for vibrating beams and plates subjected to both concentrated and distributed resonant forces. Results are given for both external and internal damping. The theory developed may be extended for other members where the possible condition of resonant vibrations may occur. Turbine blades, airplane propeller blades, and shafts of various kinds are applications where the design criteria presented herein may be found useful.
Proposed Experiments for Further Study of the Mechanism of Plastic Deformation
Authors: Koehler J. S. , Seitz F.
Published: March 2021

The purpose of this paper is to propose new experiments in the field of the plastic deformation of solids. A qualitatively satisfactory theory is discussed and is then used to suggest worth-while experiments. This theory assumes that plastic deformation is a result of the formation and motion of certain crystalline imperfections called dislocations. The nature and behavior of these imperfections are discussed. The origin of these imperfections and the changes produced in them during deformation are considered. Certain new experiments are then proposed. It is suggested that all of these experiments be done using single crystals in an attempt to simplify the interpretation of the experiments: (a) It is suggested that the internal friction, the electrical resistance, and the rate of creep all be measured on the same spectroscopically pure metal single crystal. These three measurements should be made at various temperatures and should be done successively on crystals of various crystallographic orientations. (b) It is also suggested that stress-strain curves be obtained on fine single-crystal wires. In this connection it has been shown in glass fibers that the stress concentrations at the cracks can be reduced in very thin fibers. (c) It is proposed that the electrical resistance and the internal friction of an ordered alloy be measured while the single-crystal specimen is subjected to a very small plastic deformation. (d) An attempt will be made to suggest an experiment which would enable the observer to “see” the dislocations.
Sliding Friction of Ball Bearings of the Pivot Type
Authors: Poritsky H. , Hewlett C. W. , Coleman R. E.
Published: March 2021

While ideal rotational surfaces of the pivot and the race of ball bearings can touch the spherical ball surfaces only at mathematical points, these surfaces actually “flatten” at the contact, due to elastic compression so that contact occurs over a finite area. It is shown in this paper that as a result of this flattening, owing to unavoidable small relative slipping over some of the contact areas, even the most precise and flawless ball bearings possess definite friction. This source of unavoidable friction is analyzed, and the frictional torque due to it is computed for an individual ball, for the whole bearing, and for both bearings holding a rotor or gimbal.
Optimization of photoresist plating mold fabrication for metal mask patterning
Authors: Hii Doreen , Vatanparvar Daryosh , Shkel Andrei M.
Published: March 2021

In this paper, we present results on optimization of photoresist (PR) plating molds for patterning of a nickel masking layer. The process can be adopted in a number of processes, including deep reactive ion etching of strongly bonded materials with high chemical resistance, such as fused silica (FS), borosilicate glass, and silicon carbide. The desirable plating mold attributes, such as thick PR, controlled dimension, vertical sidewall angle, and low sidewall roughness were optimized by varying exposure dose, exposure contact mode, developer dilution ratio, and PR type. We demonstrated that the PR dimensions decrease proportionally to increase of the exposure dose, where the relationship was utilized to control fabricated dimensions. To improve the sidewall angle, lowering the exposure dose was shown to reduce sidewall tapering, with further improvements possible by applying the vacuum contact exposure mode. Furthermore, we showed that by using a chemically enhanced PR, such as AZ®12XT, smooth PR sidewalls can be attained. The benefits of optimizing PR features were verified through an FS etch experiment and demonstrated a vertical etch with controlled dimension, smooth sidewall, and reduced faceting.
A one-dimensional flow model enhanced by machine learning for simulation of vocal fold vibration
Authors: Li Zheng , Chen Ye , Chang Siyuan , Rousseau Bernard , Luo Haoxiang
Published: March 2021

A one-dimensional (1D) unsteady and viscous flow model that is derived from the momentum and mass conservation equations is described, and to enhance this physics-based model, a machine learning approach is used to determine the unknown modeling parameters. Specifically, an idealized larynx model is constructed and ten cases of three-dimensional (3D) fluid–structure interaction (FSI) simulations are performed. The flow data are then extracted to train the 1D flow model using a sparse identification approach for nonlinear dynamical systems. As a result of training, we obtain the analytical expressions for the entrance effect and pressure loss in the glottis, which are then incorporated in the flow model to conveniently handle different glottal shapes due to vocal fold vibration. We apply the enhanced 1D flow model in the FSI simulation of both idealized vocal fold geometries and subject-specific anatomical geometries reconstructed from the magnetic resonance imaging images of rabbits' larynges. The 1D flow model is evaluated in both of these setups and shown to have robust performance. Therefore, it provides a fast simulation tool that is superior to the previous 1D models.
Effects of multiaxial pre-stress on Lamb and shear horizontal guided waves
Authors: Abderahmane Abdellahi , Lhémery Alain , Daniel Laurent
Published: March 2021

A theoretical model is derived to extend existing work on the theory of acoustoelasticity in isotropic materials subjected to uniaxial or hydrostatic loadings, up to the case of arbitrary triaxial loading. The model is applied to study guided wave propagation in a plate. The semi-analytical finite element method is adapted to deal with the present theory. Effects of triaxial loading on velocities of Lamb and shear horizontal (SH) modes are studied. They are non-linearly dependent on stress, and this nonlinearity is both frequency-dependent and anisotropic. Velocity changes induced by the effect of stress on the plate thickness are shown to be non-negligible. When a stress is applied, both Lamb and SH modes lose their simple polarization characteristics when they propagate in directions different from the principal directions of stress. The assumption that effects induced by a multiaxial stress equal the sum of effects induced by each of its components independently is tested. Its validity is shown to depend on frequency and propagation direction. Finally, the model is validated by comparing its predictions to theoretical and experimental results of the literature. Its predictions agree very well with measurements and are significantly more accurate than those of existing theories.
Multichannel deconvolution of vibrational signals: A state-space inverse filtering approach
Authors: Candy J. V. , Fisher K. A. , Markowicz B. A. , Paulsen D. J.
Published: March 2021

Deconvolution of noisy measurements, especially when they are multichannel, has always been a challenging problem. The processing techniques developed range from simple Fourier methods to more sophisticated model-based parametric methodologies based on the underlying acoustics of the problem at hand. Methods relying on multichannel mean-squared error processors (Wiener filters) have evolved over long periods from the seminal efforts in seismic processing. However, when more is known about the acoustics, then model-based state-space techniques incorporating the underlying process physics can improve the processing significantly. The problems of interest are the vibrational response of tightly coupled acoustic test objects excited by an out-of-the-ordinary transient, potentially impairing their operational performance. Employing a multiple input/multiple output structural model of the test objects under investigation enables the development of an inverse filter by applying subspace identification techniques during initial calibration measurements. Feasibility applications based on a mass transport experiment and test object calibration test demonstrate the ability of the processor to extract the excitations successfully.
Hyperbaric Oxygen Therapy to Treat Acute Sport-Related Traumatic Brain Injuries: A Case Series
Authors: Roby Patricia R. , Lynall Robert C. , Cools Michael J. , Marshall Stephen W. , Fonseca Janna C. , Stevens James R. , Mihalik Jason P.
Published: March 2021

We report on hyperbaric oxygen (HBO2) therapy used to improve postinjury outcomes in eight acutely concussed high school student-athletes (5 males, 3 females, mean age = 16.0 ± 1.2 years). Patients were randomly assigned into one of three intervention groups: (a) HBO2 therapy; (b) hyperbaric therapy with compressed medical-grade air (HBA); or (c) normobaric 100% O2 therapy. All patients completed five 1-hr treatments within the first 10 days following his or her concussion. Main outcome measures included mental status examination, symptom burden, and the number of days from injury until the physician permitted the student-athlete to return to activity. Patients receiving HBO2 treatment experienced the greatest absolute symptom reduction over the five treatment sessions. No meaningful differences were found in mental status examination. All participants returned to activity in a similar timeframe. HBO2 therapy may be an effective option for the acute treatment of postconcussion symptoms, particularly in young athletes presenting with a high symptom burden.
Profiling the gene editor
The Code Breaker: Jennifer Doudna, Gene Editing, and the Future of the Human Race
Walter Isaacson
Simon and Schuster, 2021. 560 pp.
Authors: Annas George J.
Published: March 2021

A new biography traces CRISPR's origins and embraces scientist-led oversight of its future
Immunity to SARS-CoV-2 variants of concern
Authors: Altmann Daniel M. , Boyton Rosemary J. , Beale Rupert
Published: March 2021

Variants show variable escape from vaccine immunity, but residual protection may suffice
Detection of Rotavirus Vaccine Strains in Oysters and Sewage and Their Relationship with the Gastroenteritis Epidemic
Authors: Ito Erika , Pu Jian , Miura Takayuki , Kazama Shinobu , Nishiyama Masateru , Ito Hiroaki , Konta Yoshimitsu , Omura Tatsuo , Watanabe Toru
Published: March 2021

We quantified rotavirus A (RVA), Rotarix, and RotaTeq strains in oyster and sewage samples during two gastroenteritis seasons and revealed the exact contamination of wild-type RVA by subtracting the quantitative value of rotavirus vaccine strains from that of RVA. The concentration of wild-type RVA was significantly correlated between oysters and sewage, although no significant correlation was seen between wild-type RVA concentration in sewage and the number of rotaviruses detected in patients with gastroenteritis.
Iminosugar Glucosidase Inhibitors Reduce Hepatic Inflammation in Hepatitis A Virus-Infected

Ifnar1
−/−

Mice
Authors: Misumi Ichiro , Li Zhucui , Sun Lu , Das Anshuman , Shiota Tomoyuki , Cullen John , Zhang Qibin , Whitmire Jason K. , Lemon Stanley M.
Published: March 2021

Hepatitis A virus (HAV) is a common cause of viral hepatitis. Iminosugar compounds block its replication in cultured cells by inhibiting the synthesis of gangliosides required for HAV cell entry but have not been tested for their ability to prevent or treat hepatitis A
in vivo
.
Spontaneous Currents and Topologically Protected States in Superconducting Hybrid Structures with the Spin–Orbit Coupling (Brief Review)
Authors: Samokhvalov A. V. , Kopasov A. A. , Kutlin A. G. , Mironov S. V. , Buzdin A. I. , Mel’nikov A. S.
Published: March 2021

The results of recent theoretical studies of features of superconducting states in hybrid structures whose properties are significantly determined by the spin–orbit effects have been reported. The two main phenomena appearing in such systems in the presence of additional spin splitting caused either by the Zeeman effect in a magnetic field or by the exchange field: (i) the generation of spontaneous currents and (ii) the appearance of topologically nontrivial superconducting phases. It has been shown that the spin–orbit coupling can be a key mechanism that allows implementing new inhomogeneous phase structures, in particular, the so-called “phase batteries.” The effect of geometric factors on the properties of topologically nontrivial superconducting states has been analyzed. New types of topological transitions in vortex states of Majorana wires have been proposed.
Hematopoietic stem cell gene therapy targeting TGFβ enhances the efficacy of irradiation therapy in a preclinical glioblastoma model
Authors: Andreou Tereza , Williams Jennifer , Brownlie Rebecca J , Salmond Robert J , Watson Erica , Shaw Gary , Melcher Alan , Wurdak Heiko , Short Susan C , Lorger Mihaela
Published: March 2021

Patients with glioblastoma (GBM) have a poor prognosis, and inefficient delivery of drugs to tumors represents a major therapeutic hurdle. Hematopoietic stem cell (HSC)-derived myeloid cells efficiently home to GBM and constitute up to 50% of intratumoral cells, making them highly appropriate therapeutic delivery vehicles. Because myeloid cells are ubiquitously present in the body, we recently established a lentiviral vector containing matrix metalloproteinase 14 (MMP14) promoter, which is active specifically in tumor-infiltrating myeloid cells as opposed to myeloid cells in other tissues, and resulted in a specific delivery of transgenes to brain metastases in HSC gene therapy. Here, we used this novel approach to target transforming growth factor beta (TGFβ) as a key tumor-promoting factor in GBM. Transplantation of HSCs transduced with lentiviral vector expressing green fluorescent protein (GFP) into lethally irradiated recipient mice was followed by intracranial implantation of GBM cells. Tumor-infiltrating HSC progeny was characterized by flow cytometry. In therapy studies, mice were transplanted with HSCs transduced with lentiviral vector expressing soluble TGFβ receptor II–Fc fusion protein under MMP14 promoter. This TGFβ-blocking therapy was compared with the targeted tumor irradiation, the combination of the two therapies, and control. Tumor growth and survival were quantified (statistical significance determined by t-test and log-rank test). T cell memory response was probed through a repeated tumor challenge. Myeloid cells were the most abundant HSC-derived population infiltrating GBM. TGFβ-blocking HSC gene therapy in combination with irradiation significantly reduced tumor burden as compared with monotherapies and the control, and significantly prolonged survival as compared with the control and TGFβ-blocking monotherapy. Long-term protection from GBM was achieved only with the combination treatment (25% of the mice) and was accompanied by a significant increase in CD8+ T cells at the tumor implantation site following tumor rechallenge. We demonstrated a preclinical proof-of-principle for tumor myeloid cell-specific HSC gene therapy in GBM. In the clinic, HSC gene therapy is being successfully used in non-cancerous brain disorders and the feasibility of HSC gene therapy in patients with glioma has been demonstrated in the context of bone marrow protection. This indicates an opportunity for clinical translation of our therapeutic approach.
Biofilm-forming ability of poultry Campylobacter jejuni strains in the presence and absence of Pseudomonas aeruginosa
Authors: Scheik Letícia Klein , Volcan Maia Darla Silveira , Würfel Simone de Fátima Rauber , Ramires Tassiana , Kleinubing Natalie Rauber , Haubert Louise , Lopes Graciela Volz , da Silva Wladimir Padilha
Published: March 2021

The aims of this study were to evaluate the ability of Campylobacter jejuni isolated from a poultry slaughterhouse to form biofilm in the presence and absence of Pseudomonas aeruginosa, and the effect of surface (stainless steel, polystyrene), temperature (7, 25, and 42 °C), and oxygen concentration (microaerophilic and aerobic conditions) on the formation of biofilm. The genes ahpC, cadF, clpP, dnaJ, docA, flaA, flaB, katA, kpsM, luxS, racR, and sodB, related to biofilm formation by C. jejuni, were also investigated. All isolates formed biofilm on stainless steel and on polystyrene, in both aerobic and microaerophilic atmospheres, including temperatures not optimal for C. jejuni growth (7 and 25 °C), and biofilm also was formed in the presence of P. aeruginosa. In dual-species biofilm on stainless steel, biofilm formation was 2–6 log CFU·cm−2 higher at 7 °C for all isolates, in comparison with monospecies biofilm. Ten genes (ahpC, cadF, clpP, dnaJ, docA, flaA, flaB, luxS, racR, and sodB) were detected in all isolates, but katA and kpsM were found in four and six isolates, respectively. The results obtained are of concern because the poultry C. jejuni isolates form biofilm in different conditions, which is enhanced in the presence of other biofilm formers, such as P. aeruginosa.
Precision measurement of the electron orbital gyromagnetic factor: relativistic contributions from zitterbewegung
Authors: Awobode A.M.
Published: March 2021

The contribution, by zitterbewegung, to a probable correction to the electron orbital g-factor is calculated. For an electron in a magnetic field, the orbital g-factor gL is not equal to 1 exactly, and the calculated anomaly, compared with the experimentally observed values, are in reasonable agreement, both in sign and order of magnitude. The contribution of zitterbewegung to the linewidth or broadening of a Landau level is calculated. An expression for the lifetime of a state is derived, showing that the electron is placed, due to zitterbewegung, in a state with a finite lifetime, with the probable emission/absorption of massless particles. The expected anomaly in the electron orbital g-factor may be measured using high-precision spectroscopic techniques.