bluuebunny/crossref_metadata_2025 huggingface dataset:
Chylothorax associated with lymphatic reflux in a thoracic duct tributary after lung cancer surgery
Authors: Ishida Hironori , Nakazawa Ken , Yanagihara Akitoshi , Umesaki Tetsuya , Taguchi Ryo , Yamada Akiko , Nitanda Hiroyuki , Sakaguchi Hirozo
Published: June 2021

Chyle leaks are attributed to damage to the thoracic duct itself or its tributaries during surgery. Chylothorax after lung cancer surgery can occur due to damaged thoracic duct tributaries; however, little is known of the mechanism involved. A 71‐year‐old female underwent a left upper lobectomy with hilar and mediastinal lymphadenectomy for a 1.8‐cm primary squamous cell carcinoma, and developed a chylothorax a day later. Catheter lymphangiography revealed high‐flow chyle leaks from a damaged thoracic duct tributary, known as a bronchomediastinal lymph trunk, due to a lymphatic reflex from the thoracic duct. Subsequently, catheter embolization of the tributary repaired the chylothorax. The potential for persistent chylothorax after lung cancer surgery and successful lymphatic intervention should be noted.
Patient perceptions of surgical telehealth consultations during the COVID 19 pandemic in Australia: Lessons for future implementation
Authors: Wiadji Elvina , Mackenzie Lisa , Reeder Patrick , Gani Jonathan S. , Ahmadi Sima , Carroll Rosemary , Smith Stephen , Frydenberg Mark , O'Neill Christine J.
Published: June 2021

Introduction

Prior studies of telehealth report high levels of patient satisfaction, but within carefully selected clinical scenarios. The COVID‐19 pandemic led to telehealth replacing face‐to‐face care for many surgical consultations across a variety of situations. More evidence is needed regarding patient perceptions of telehealth in surgery, in particular, exploring barriers and facilitators associated with its sustained implementation beyond the pandemic.

Methods

Survey invitations were emailed to a convenience sample of surgical patients by their surgeon following a telehealth consultation during the COVID‐19 pandemic. Surgeons were recruited from a sample (n = 683) who completed a survey on telehealth (distributed via email to all Australian Fellows of the Royal Australasian College of Surgeons). Mixed methods analysis was performed of the patient survey data.

Results

A total of 1166 consultations were captured: 50% routine reviews, 17% initial appointments and 20% post‐operative reviews. Video‐link was used in 49% of consultations. The majority of patients (94%), were satisfied with the quality of their surgical telehealth consultation and 75% felt it delivered the same level of care as face‐to‐face encounters. Telehealth was convenient to use (96%) and led to cost savings for 60% of patients. When asked about future appointment preferences after the pandemic, 41% indicated they would prefer telehealth (24% video‐link and 17% telephone) over face‐to‐face appointments. There was a perception by patients that telehealth consultation fees should be less than face‐to‐face consultation fees.

Conclusion

Patient satisfaction with surgical telehealth consultations is high. Barriers to more widespread implementation include financial, clinical appropriateness, technical and confidentiality concerns.
It's not you, it's me: a descriptive study of patient complaints and surgeon understanding
Authors: McSweeney William , Leaning Matthew , Dastouri Darius , Parkinson Debra , Hendahewa Rasika
Published: June 2021

Background

Patient complaints are an underutilized and under‐addressed issue in general surgery. They represent a unique sphere of interaction for surgeons and patients to understand motivations and failures in the delivery of healthcare. The aims of this study were to identify motivators of patient complaints and understand surgeon's awareness of this issue.

Methods

A retrospective review of patient complaint data in a single regional general surgical department was undertaken between the periods October 2017 to June 2020 and June 2018 to October 2020 relating to patient demographics and subject of complaint. Secondly, an anonymous survey was conducted across the same department and results tabulated by seniority.

Results

Two hundred and nineteen complaints were received during the study period. One hundred and thirteen were made by patients, while 56 were made by family members. One hundred and fifty‐nine complaints were related to an inpatient episode of care, and 152 were made in writing. The majority of complainants were female, with a mean age of 52. The most common reason for complaint was “treatment” (n = 102), followed by communication (n = 48), and humaneness/caring (n = 44). Consultant surgeons and surgical trainees placed communication, humaneness/caring, and professionalism as most likely to incite complaints, while interns were more likely to prioritize other measures such as patient healthcare rights and medications.

Conclusion

Patient complaints remain a relatively under‐utilized resource in addressing the downfalls of general surgical departments. This study reports patient demographics that are congruent with the literature and highlights that surgeons prioritize many non‐technical skills in the maintenance of the doctor‐patient relationship, in contrast to preconceptions.
Sentenced to Life: Reflections on the Inability to Bear Vitality, Following the Movie Turtles Can Fly
Authors: Schellekes Alina
Published: June 2021

The paper focuses on psychic states in which living and bearing one's vitality have become hindered or totally obstructed, either as a result of a primary trauma or of a late‐onset trauma. The author relates especially to patients who have been severely traumatized and have withdrawn into encapsulated states with schizoid/autistic‐like features that create complex challenges in therapy. The paper weaves together clinical cases with theoretical understandings and with a discussion of the Kurdish movie Turtles Can Fly, in which many orphan Kurdish refugee children try to survive emotionally the traumatic life they have been going through. The author discusses the complex states of mind of the patients presented and of the orphans in the movie, who are sentenced to life, having lost all their hope and ability to tolerate their own vitality or that of others, due to extreme traumas. Consequently an encounter between themselves and another person, including a therapist/analyst, frequently becomes a flooding experience that is beyond their abilities to assimilate, being experienced as an annihilating threat to one's emotional existence and being in danger of creating states of a therapeutic and undigestible excess for which the term toxemia of therapy is suggested.
Independent primary cutaneous and mammary apocrine carcinomas with neuroendocrine differentiation: Report of a case and literature review
Authors: DeCoste Ryan C. , Carter Michael D. , Barnes Penelope J. , Andea Aleodor A. , Wang Min , Rayson Daniel , Walsh Noreen M.
Published: June 2021

Cutaneous apocrine carcinomas share common features with their counterparts in the breast; hence, metastatic mammary carcinoma must be excluded before such lesions can be designated primary cutaneous neoplasms. Primary tumors from either source rarely exhibit neuroendocrine differentiation. We report a case of a 72‐year‐old female with a painless 1.2‐cm scalp nodule. An incisional biopsy revealed dermal involvement by an invasive apocrine carcinoma juxtaposed to a benign apocrine cystic lesion. Immunohistochemically, the carcinoma expressed neuroendocrine proteins including synaptophysin, chromogranin, and CD56. A primary cutaneous apocrine carcinoma with neuroendocrine differentiation was favored, but additional investigations to exclude breast origin were recommended. These revealed a 1.1‐cm nodule in the right breast, which proved to be an invasive ductal carcinoma, morphologically and immunophenotypically similar to the scalp lesion. This confounded the case, yet factors militating against metastatic breast carcinoma to skin included (a) the small size of the mammary tumor, (b) absence of other metastatic disease, and (c) juxtaposition of the scalp carcinoma to a putative benign precursor. Molecular studies were undertaken to resolve the diagnostic quandary. Single nucleotide polymorphism microarray analysis revealed distinct patterns of chromosomal copy number alterations in the two tumors, supporting the concept of synchronous and unusual primary neoplasms.
Interventions involving own treatment choice for people living with coexisting severe mental illness and type 1 or 2 diabetes: A scoping review
Authors: Zabell Vicki , Rønne Sabrina T. , Høgsgaard Ditte , Jørgensen Rikke , Gæde Peter H. , Arnfred Sidse M.
Published: June 2021

Aim

The objective of this scoping review was to summarize, understand and provide an overview of the empirical literature on interventions involving own treatment choice for people with coexisting diabetes (type 1 and 2) and severe mental illness (SMI).

Methods

This scoping review undertook a systematic literature assessment. Searches were performed in MEDLINE, Embase, PsycINFO, Web of Science, CINAHL, the Cochrane Library and grey literature (OpenGrey, Google Scholar and Danish Health and Medicine Authority databases). Publications from 2000 to July 2020 were of interest. Studies were included if they involved the users’ own choice of treatment. Included studies: RCT, intervention, cohort and case‐based studies.

Results

A total of 4320 articles were screened, of which nine were included. The review identified eight studies from the United States and one from Canada testing different interventions for people with SMI and diabetes (one diabetes education program, five randomized controlled trials, one retrospective cohort study, one naturalistic intervention program and one case vignette). The interventions described in the nine articles involved service users, the majority incorporated individualized healthcare plans, and all interventions were based on multidisciplinary teamwork.

Conclusions

Research in the area is limited. Care management interventions tend to focus on a single condition, paradoxically excluding SMI during enrolment. Interventions aimed at people with both conditions often prioritize one condition treatment leading to an unbalanced care.
Epigenetic regulation and signalling pathways in Merkel cell development
Authors: Oss‐Ronen Liat , Cohen Idan
Published: June 2021

Merkel cells are specialized epithelial cells connected to afferent nerve endings responsible for light‐touch sensations, formed at specific locations in touch‐sensitive regions of the mammalian skin. Although Merkel cells are descendants of the epidermal lineage, little is known about the mechanisms responsible for the development of these unique mechanosensory cells. Recent studies have highlighted that the Polycomb group (PcG) of proteins play a significant role in spatiotemporal regulation of Merkel cell formation. In addition, several of the major signalling pathways involved in skin development have been shown to regulate Merkel cell development as well. Here, we summarize the current understandings of the role of developmental regulators in Merkel cell formation, including the interplay between the epigenetic machinery and key signalling pathways, and the lineage‐specific transcription factors involved in the regulation of Merkel cell development.
Consumers’ purchase behaviour and green marketing: A synthesis, review and agenda
Authors: Sharma Ajai Pal
Published: June 2021

The study presents an overview of green marketing and the gap between attitude and actual purchase behaviour of consumers towards green products. A total of 232 studies have been analysed using a systematic review to develop a green purchase decision‐making model. A thematic analysis helped in the identification of three major themes namely; personal factors affecting green purchase; green purchase; and green marketing mix. The concern for eco‐environment, eco‐labelling, past experiences and perceived usefulness have been identified as major influencers of green consumer behaviour. Lack of environmental knowledge, price, perceived associated risks, organizational image, trust, and willingness to pay has been identified as barriers, creating a gap between attitude and actual purchase behaviour of consumers towards green products. On the basis of analysis, a green purchase decision model has been proposed and also potential areas of future research have been suggested.
The creation and implementation of advanced practice nursing in France: Experiences from the field
Authors: Colson Sébastien , Schwingrouber Jocelyn , Evans Catherine , Roman Christophe , Bourriquen Maryline , Lucas Guillaume , Mellinas Marie , Brunet Philippe , Cermolacce Michel , Chinot Olivier , Mayen Sandrine , Berbis Philippe
Published: June 2021

Aim

This paper describes the characteristics of the new advanced practice nursing roles in France, as well as their challenges and perspectives, and compares the French model with the recommendations of the International Council of Nurses.

Background

Advanced practice nursing is particularly well established in English‐speaking countries. Since 2018, France has become the second French‐speaking region to legalize and regulate advanced practice nurses.

Source of evidence

The International Council of Nurses and French government websites, and scientific databases (PubMed, CINALH, Cochrane Library) were explored. Feedback from French nursing academics was also requested.

Discussion

The advanced practice nursing model in France is described according to the scope and conditions of professional practice. The educational program leads to a State diploma with master’s degree, which it is mandatory to be a registered nurse. Remuneration depends on the sector of practice in the public hospital, primary care or private sector. Although there is no national strategy for the implementation of advanced practice nursing roles, research projects are being initiated to guide and evaluate the practice. Based on concordance analysis with the recommendations of the International Council of Nurses, the French advanced practice nursing model appears to be similar to the nurse practitioner model.

Conclusion

Adjustments in the scope of practice and education can be expected as the implementation of these roles is evaluated.

Implications for nursing practice

This is a historical evolution of the nursing profession in France, for which communication with patients and healthcare professionals is essential.

Implications for nursing policy

The implementation of advanced practice nursing roles in clinical settings requires the development of national strategies to support initiatives and ensure the sustainability of these roles.
CEO cultural heritage and the pricing of audit services
Authors: Pham Anh Viet , Pham Mia Hang , Truong Cameron
Published: June 2021

We construct preferences toward risk and uncertainty as reflected in the cultural heritage of chief executive officers (CEOs) managing public firms in the United States. We demonstrate that auditors take into account the cultural traits of CEOs in the pricing of their audit services. We also show that CEO cultural heritage is associated with a firm's misreporting, internal control weakness, and accounting conservatism. The results are robust to controlling for other known attributes of CEOs, firm characteristics, and corporate governance. Our study contributes to research on corporate risk culture, CEO characteristics, and determinants of the pricing of audit services and financial reporting quality.
Microstructure of paneer prepared by automated pressing technique
Authors: Sinha Chitranayak , Manjunatha M.  , Jayaraj Rao K.  , Sinha Pushpanayak , Kumari Khushbu , G. Kumar Mahesh , Dabas Jitender Kumar
Published: June 2021

In this study, paneer was prepared by conventional method as well as by employing an automated pressing equipment and microstructure of paneer samples was studied by scanning electron microscopy. Further, pneumatic pressing of the hot coagulum was carried out at different pressures (2.5, 3.0, and 3.5 kg cm−2) and time durations (10, 12.5, and 15 min) using a semi‐automated microprocessor based pneumatic pressing unit. It was found that the microstructure of paneer comprised mainly of continuous medium of casein matrix in which micro‐pores were distributed. However, differences were observed in the way the curd particles were fused during the pressing process of paneer manufacture. Paneer obtained from the automated press was found to possess more uniformity than the one prepared by conventional method. This was attributed to more uniform pressure applied by the automated technique. Further, porosity values were correlated with the openness observed in the microstructure of paneer. It was found that at an optimized pressure and time combination, paneer had a more uniform structure along with porosity than conventionally made one. The dependence of the paneer properties on the pressure and pressing time was well fitted to polynomial quadratic model which showed influence of pressure applied is greater than the time of pressing.

Practical Applications

The SEM imaging of paneer prepared by automated pneumatic pressing based technique could be very useful in analyzing the microstructure which influences the texture and amount of water retention. Small to medium scale paneer manufacturers could very well utilize the automated pneumatic pressing technique to produce paneer of optimum texture and adequate amount of moisture. Paneer manufacturers of small to medium scale could very well utilize this pressing technique to increase their income at farm level.
Care dependency of patients and residents at the end of life: A secondary data analysis of data from a cross‐sectional study in hospitals and geriatric institutions
Authors: Schüttengruber Gerhilde , Halfens Ruud J. G. , Lohrmann Christa
Published: June 2021

Aims and objectives

The holistic care dependency concept can be applied to gain comprehensive insights into individuals’ care needs in the end‐of‐life (EoL) phase. This study was carried out to measure and characterise the “care dependency” phenomenon in this phase and to obtain deeper knowledge about this phenomenon.

Background

The end of a human life is often characterised by a physical decline, often implying that a high amount of care is needed. Non‐malignant diseases can develop unpredictably; therefore, it is difficult to detect the onset of the EoL phase.

Design

Data were collected in a cross‐sectional multicentre study, using the Austrian Nursing Quality Measurement 2.0.

Methods

Descriptive and multivariate statistical methods were used. Care dependency was measured with the Care Dependency Scale (CDS). The study follows the STROBE guideline.

Results

Ten per cent (n = 389) of the sample (N = 3589) were allocated to “a pathway for management of patients at the end of life.” The patients and residents in the EoL phase are significantly older and more often diagnosed with dementia, and circulatory system and musculoskeletal system diseases. Of these patients, 60% were care dependent completely or to a great extent. Dementia and age represent main influencing factors that affect the degree of care dependency at the end of life.

Conclusion

Our results show that the “typical” EoL patient or resident is female, old and affected by dementia and/or circulatory system diseases. Dementia and age were identified as main factors that contribute to very high care dependency.

Relevance to clinical practice

The measurement of care dependency may support the identification of special care needs in the EoL phase. Gaining deeper knowledge about the care dependency phenomenon can also help healthcare staff better understand the needs of patients with non‐malignant conditions in their last phase of life.
High‐frequency trading: Definition, implications, and controversies
Authors: Zaharudin Khairul Zharif , Young Martin R. , Hsu Wei‐Huei
Published: June 2021

High‐frequency trading (HFT) is an important component of stock market activity on major exchanges. In the United States, HFT contributed approximately 52% of total equity trading in 2018, with an estimated value of more than US$17 trillion. However, to date, there is no standard definition of HFT, and how it is perceived or viewed depends on the underlying criteria set by regulators. The lack of a uniform identification for HFT leads to problems, such as research complications, that lead to somewhat conflicting conclusions as to the effect of HFT on equity markets in general and the market microstructure in particular. This article presents a survey of the definitions, measurements, mechanisms, empirical evidence, and relevant controversies and issues pertaining to HFT.
Influence of the median lobe on the results at 4 years of the prostate vaporization by GreenLight laser
Authors: Vanalderwerelt Victor , Pradère Benjamin , Grevez Tristan , Faivre D'Arcier Benjamin , Bruyère Franck
Published: June 2021

Objective

The aim of this study was to examine the influence of a median lobe (ML) on complications and functional results after 4 years of GreenLight photoselective vaporization of the prostate (PVP).

Methods

All men undergoing GreenLight PVP for benign prostatic hyperplasia were included in the baseline analysis and followed prospectively. Two groups were formed according to the presence or absence of the prostatic ML. Complications classified according Clavien and Dindo and functional results (International Prostate Symptom Score [IPSS], quality of life, maximum urinary flow rate [Qmax], and postvoid residual [PVR]) were evaluated with 4 years of follow‐up. The pre‐ and postoperative data were compared by a chi‐square test (χ2) for the qualitative variables and by a Student t test for the quantitative variables.

Results

A total of 432 patients (172 with ML and 260 without ML) were included prospectively from September 2005 to October 2013. The initial populations were comparable. At 4 years of follow‐up, the improvement in mean IPSS was significantly greater for patients with ML at 6, 12, 24, and 48 months. The improvement in Qmax was significantly greater for patients with ML at 1, 6, 24, and 48 months. There was no significant difference between the two groups concerning the PVR reduction, the occurrence of complications, the level of average prostate‐specific antigen, and the average ultrasound volume at 4 years.

Conclusion

There is a clearer and longer‐lasting improvement in urinary symptoms in patients with prostatic ML. The indication of PVP in those patients seems to be excellent, with good results persisting at 4 years.
Bayesian Skyline Plots disagree with range size changes based on Species Distribution Models for Holarctic birds
Authors: Miller Eleanor F. , Green Rhys E. , Balmford Andrew , Maisano Delser Pierpaolo , Beyer Robert , Somveille Marius , Leonardi Michela , Amos William , Manica Andrea
Published: June 2021

During the Quaternary, large climate oscillations impacted the distribution and demography of species globally. Two approaches have played a major role in reconstructing changes through time: Bayesian Skyline Plots (BSPs), which reconstruct population fluctuations based on genetic data, and Species Distribution Models (SDMs), which allow us to back‐cast the range occupied by a species based on its climatic preferences. In this paper, we contrast these two approaches by applying them to a large data set of 102 Holarctic bird species, for which both mitochondrial DNA sequences and distribution maps are available, to reconstruct their dynamics since the Last Glacial Maximum (LGM). Most species experienced an increase in effective population size (Ne, as estimated by BSPs) as well as an increase in geographical range (as reconstructed by SDMs) since the LGM; however, we found no correlation between the magnitude of changes in Ne and range size. The only clear signal we could detect was a later and greater increase in Ne for wetland birds compared to species that live in other habitats, a probable consequence of a delayed and more extensive increase in the extent of this habitat type after the LGM. The lack of correlation between SDM and BSP reconstructions could not be reconciled even when range shifts were considered. We suggest that this pattern might be linked to changes in population densities, which can be independent of range changes, and caution that interpreting either SDMs or BSPs independently is problematic and potentially misleading.
Critical appraisal of different triggering pathways for the pathobiology of pemphigus vulgaris—A review
Authors: R Hannah , Ramani Pratibha , Tilakaratne WM , Sukumaran Gheena , Ramasubramanian Abilasha , Krishnan Reshma Poothakulath
Published: June 2021

Pemphigus vulgaris is an autoimmune blistering disease with an increased potential for mortality. The epithelium is key in understanding the pathobiology as it is specialized to perform functions like mechanical protection, immunological defense, and proprioception. In order to perform these array of functions, epithelial integrity is important. This integrity is maintained by a host of molecules which orchestrate the ability of the keratinocytes to function as a single unit. Desmoglein 3 antibodies formed in genetically susceptible individuals are known to cause the disruption of the intact oral mucosa leading to the formation of blisters in pemphigus vulgaris patients. However, there are underlying complex triggering pathways leading to the clinical disease. The aim of the review is to congregate and critically appraise the various triggering pathways which contribute toward the pathobiology of pemphigus vulgaris. Articles relevant to the pathobiology of pemphigus vulgaris were identified from various search databases till the year 2020. The pathogenesis of pemphigus vulgaris is complex, and it involves an in‐depth understanding of the various predisposing factors, provoking factors, and progression mechanisms. Congregation of the various triggering pathways will open our minds to understand pemphigus vulgaris better and in turn develop a reliable treatment in the near future.
Community composition influences ecosystem resistance and production more than species richness or intraspecific diversity
Authors: Bowker Matthew A. , Rengifo‐Faiffer M. Cristina , Antoninka Anita J. , Grover Henry S. , Coe Kirsten K. , Fisher Kirsten , Mishler Brent D. , Oliver Mel , Stark Lloyd R.
Published: June 2021

Biodiversity describes the variety of life and may influence properties and processes of ecosystems, such as biomass production and resistance to disturbance. We investigated the effects of multiple facets of biodiversity – species richness and composition of the community, and intraspecific diversity in two key species – on both production and resistance of experimentally‐assembled biological soil crusts (biocrusts). We found that productivity was most strongly influenced by community composition (variation in the presence and relative proportions of community members), and weakly positively influenced by species richness. Intraspecific diversity, encompassing both the richness and composition of clones, had a neutral effect on community productivity within one focal species (Syntrichia caninervis), but a moderately negative effect on productivity within the other focal species (S. ruralis). Resistance was also most strongly influenced by community composition, although different sets of species contributed most to resistance and production. Resistance was not affected by either species richness or intraspecific diversity in either focal species. Our findings supported our general expectation that community‐level facets of biodiversity would be more influential than intraspecific diversity within a species because trait variability among species is usually greater than that within. These results also indicated that although species richness is often thought to strongly affect both productivity and resistance, the presence, absence and relative abundance of particular species may be more influential to both. Simultaneous manipulation of multiple facets of biodiversity in experiments may lead to a more complete understanding of the variety of ways in which biodiversity may regulate ecological systems.
Breeding plant type for adaptation to high plant density in tropical maize—A step towards productivity enhancement
Authors: Sandhu Surinder , Dhillon Baldev Singh
Published: June 2021

Breeding for tolerance to high plant density (HPD) stress resulted in remarkable increase in grain yield per unit area in temperate maize. In spite of improved germplasm and reasonable adoption of hybrid technology, average maize productivity in tropics is still much below the achievable potential, primarily due to natural abiotic stresses and poor management due to lack of access to key inputs. A tropical maize plant, inherently distinguished with tall stem, numerous long dropping leaves, bushy tassel, rapid postsilking leaf senescence and prone to lodging, needs to be redesigned for amenability to HPD stress. With reference to the historical outlook on plant type modifications in temperate maize for adaptation to HPD and, hence, to minimize decrease in grain yield per plant resulting from crowding stress, we delineated HPD adaptation traits, which need to be focused during selection to enhance the productivity in tropical maize, a source of food, feed and livelihood to millions of resources‐poor farmers.
Geochemical record of the subsurface redox gradient in marine red beds: A case study from the Devonian Prague Basin, Czechia
Authors: Bábek Ondřej , Vodrážková Stanislava , Kumpan Tomáš , Kalvoda Jiří , Holá Markéta , Ackerman Lukáš
Published: June 2021

Marine red beds are usually interpreted as indicating water column oligotrophy, good bottom‐water oxygenation and redox conditions. Lower Devonian successions of the Prague Basin, Czechia, exhibit a distinct centimetre to metre‐scale alternation of layers of marine red beds, grey carbonates, marls and black shales. In order to understand why the redox potential fluctuated so rapidly, reflectance spectroscopy, microscopy, elemental geochemistry data and stable isotopes of Mo have been analysed in this paper. Whilst the grey and black facies only contain goethite, the marine red beds are enriched with synsedimentary and early diagenetic, submicronic hematite, which is present in micrite, skeletal interiors, microstromatolites and oncoids. It was formed by microbially mediated precipitation, the replacement of detrital Fe phyllosilicates, and/or by the oxidation of microbially precipitated Fe‐bearing aluminosilicate precursors. The marine red beds are frequently enriched in Fe, depleted in U, V, Mo and Cu, and show negative δ98Mo values indicating oxic conditions. Peloidal micrite, microbial coatings and cements with the marine red beds exhibit positive (up to 9) Ce/Ce* anomalies. The non‐red facies show opposite patterns. This geochemical variability is probably related to Mn oxyhydroxide cycling and organic matter remineralization along the sediment subsurface redox gradient, particularly by reactions between pore water and various elemental pools. These patterns, combined with the centimetre‐scale colour alternation of the sediments, may reflect redox zonation that has been preserved beneath the ancient seafloor. Four zones are recognized: (i) the oxic zone of Fe‐oxide precipitation (marine red beds); suboxic zones of (ii) Fe enrichment, and (iii) U‐Mo enrichment; and (iv) suboxic–anoxic zone of Cu, V (± Mo) enrichment. The presented model of a marine red bed origin from redox reactions in the sediment subsurface contradicts models of the formation of marine red beds through iron enrichment from Fe2+ supersaturated ocean waters following periods of ocean anoxia.
Autonomous Docking of Hybrid-Wheeled Modular Robots With an Integrated Active Genderless Docking Mechanism
Authors: Sohal Shubhdildeep Singh , Sebastian Bijo , Ben-Tzvi Pinhas
Published: June 2021

This paper presents a self-reconfigurable modular robot with an integrated two degrees-of-freedom (DOF) active docking mechanism. Active docking in modular robotic systems has received a lot of interest recently as it allows small versatile robotic systems to coalesce and achieve the structural benefits of large systems. This feature enables reconfigurable modular robotic systems to bridge the gap between small agile systems and larger robotic systems. The proposed self-reconfigurable mobile robot design exhibits dual mobility using a tracked drive for longitudinal locomotion and a wheeled drive for lateral locomotion. The 2-DOF docking interface allows for efficient docking while tolerating misalignments. To aid autonomous docking, visual marker-based tracking is used to detect and re-position the source robot relative to the target robot. The tracked features are then used in Image-Based Visual Servoing to bring the robots close enough for the docking procedure. The hybrid-tracking algorithm allows eliminating external pixelated noise in the image plane resulting in higher tracking accuracy along with faster frame update on a low-cost onboard computational device. This paper presents the overall mechanical design and the integration details of the modular robotic module with the docking mechanism. An overview of the autonomous tracking and docking algorithm is presented along with a proof-of-concept real-world demonstration of autonomous docking and self-reconfigurability. Experimental results to validate the robustness of the proposed tracking method, as well as the reliability of the autonomous docking procedure, are also presented.
A Normal Equation-Based Extreme Learning Machine for Solving Linear Partial Differential Equations
Authors: Dwivedi Vikas , Srinivasan Balaji
Published: June 2021

This paper develops an extreme learning machine for solving linear partial differential equations (PDEs) by extending the normal equations approach for linear regression. The normal equations method is typically used when the amount of available data is small. In PDEs, the only available ground truths are the boundary and initial conditions (BC and IC). We use the physics-based cost function use in state-of-the-art deep neural network-based PDE solvers called physics-informed neural network (PINN) to compensate for the small data. However, unlike PINN, we derive the normal equations for PDEs and directly solve them to compute the network parameters. We demonstrate our method’s feasibility and efficiency by solving several problems like function approximation, solving ordinary differential equations (ODEs), and steady and unsteady PDEs on regular and complicated geometries. We also highlight our method’s limitation in capturing sharp gradients and propose its domain distributed version to overcome this issue. We show that this approach is much faster than traditional gradient descent-based approaches and offers an alternative to conventional numerical methods in solving PDEs in complicated geometries.
Effect of the welding process on microstructure, microhardness and residual stresses of capacitor discharge stud welded joint
Authors: Zhang Qian , Zhang Bao-Zhu , Luo Yun , Yang Gang , Zheng Hong-xiang
Published: June 2021

Capacitor discharge (CD) stud welding is a common and fast connection technology. This paper presents an experimental and simulation study of the stud weld joint of copper stud and carbon plate. An optimized stud welding process was proposed based on microstructure, microhardness and residual stresses of CD stud welded joint. The results show that a narrow weld seam with widmanstaten structure were formed because of quickly cooling. For the longer stud extension length, the width of weld zone becomes wider and the microstructure becomes more uniform. As the increase of welding voltage and stud extension length, the microhardness increases then decreases. However, the residual stresses are increased with welding voltage increases, while they are decreased with the increases of stud extension length. The optimized welding voltage and stud extension length should be designed to 90 V and 5 mm, respectively. This study will provide a great significance to the stud welding on site.
Master Sintering Curve of W-Mo-Cu Alloy Prepared by Electric Field Sintering
Authors: Liu Yanfang , Feng Keqin , Zhou Hongling
Published: June 2021

The master sintering curve (MSC) was developed for the densification description and prediction of W-Mo-Cu alloy sintered by electric field sintering. W-Mo-Cu compacts were sintered at a temperature of 975 °C, the pressure of 30 MPa, and heating rate of 25,75,125 °C/s, respectively. The MSC of W-Mo-Cu alloy was successfully constructed with the calculated value Q = 110 kJ/mol and experimental data (such as shrinkage data and sintering time and temperature) of the compact. The shrinkage response and the densification process of the compact were studied with the MSC. What is more, the densification of the alloy was verified and predicted by the MSC. The results show that the MSC is a promising strategy for predicting the densification evolution of the ternary alloy during sintering.
Optimum Design and Trafficability Analysis for an Articulated Wheel-Legged Forestry Chassis
Authors: Sun Zhibo , Zhang Dan , Li Zhilong , Shi Yan , Wang Na
Published: June 2021

High trafficability and stability are the most two significant features of the forestry chassis. In this study, in order to improve surface trafficability, a novel articulated wheel-legged forestry chassis (AWLFC) is presented. To balance the trafficability and stability, a serial suspension system which is a combination with the active four-bar linkage articulated suspension (AFLAS) and passive V shape rocker-bogie is proposed. Then, parameter optimization with a comprehensive object function is implemented not only to enhance the trafficability and stability benefit of the structure but also to reduce the wheel slip. After that, through the flexible kinematic model based on screw theory, characteristics such as leveling ability and surface profile accessibility of the chassis are analyzed. The minimum accessible radius is obtained as 3088 mm, and the longitudinal and lateral leveling angle reaches to 22 deg and 28.7 deg separately. The new chassis performs better on leveling ability and surface profile accessibility than the forestry chassis in the current literature. Finally, through the results of simulation and prototype experiment, error rates related to the flexible analysis are reduced by 12.2% and 8.6% compared with the rigid model. Previously inaccessible forestry working environments can be available with the development of AWLFC.
Titanium infiltration into ultrathin PMMA brushes
Authors: Mani-Gonzalez Pierre Giovanni , McFeely Caitlin , Snelgrove Matthew , Shiel Kyle , Hernandez Marquez Jesus Alfredo , O’Connor Robert
Published: June 2021

Vapor phase infiltration (VPI) is a bottom-up process that involves the infiltration of polymers, often using atomic layer deposition compatible precursors. By exposing a polymer to an organo-metallic precursor, area selective material formation is achieved where the precursor reacts with regions covered by an infiltration-receptive polymer brush. Combining receptive and rejecting polymers that have the capability of forming complex nanopatterns could potentially allow for the creation of nanofeatures, offering a route to area selective deposition. This work is concerned with the creation and characterization of titanium-infiltrated films with a VPI process. Thin films of poly(methyl methacrylate) (PMMA) were infused with titanium isopropoxide and subsequently analyzed with angular resolved x-ray photoelectron spectroscopy. All XPS analysis and VPI treatments were completed without breaking vacuum in an integrated ultrahigh vacuum setup, with O 1s, C 1s, Ti 2p, and Si 2p core levels revealing the successful incorporation of titanium into the polymer. Grazing angle Fourier-transform infrared spectroscopy demonstrates the breaking of carbon–oxygen double bonds within the PMMA structure due to titanium incorporation.
Dynamics and rheology of ring-linear blend semidilute solutions in extensional flow. Part I: Modeling and molecular simulations
Authors: Young Charles D. , Zhou Yuecheng , Schroeder Charles M. , Sing Charles E.
Published: June 2021

We use Brownian dynamics (BD) simulations and single molecule experiments to investigate the influence of topological constraints and hydrodynamic interactions on the dynamics and rheology of solutions of ring-linear polymer blends at the overlap concentration. We find agreement between simulation and experiment in which rings in solution blends exhibit large conformational fluctuations. A subpopulation of rings shows extension overshoots in the startup of the flow, and other populations display tumbling and tank-treading at the steady state. Ring polymer fluctuations increase with the blend fraction of linear polymers and are peaked at a ring Weissenberg number WiR≈1.5. On the contrary, linear and ring polymers in pure solutions show a peak in fluctuations at the critical coil-stretch Weissenberg number Wi=0.5. BD simulations show that extension overshoots on the startup of the flow are due to flow-induced intermolecular ring-linear polymer hooks, whereas fluctuations at the steady state are dominated by intermolecular hydrodynamic interactions (HIs). This is supported by simulations of bidisperse linear polymer solution blends, which show similar trends in conformational dynamics between rings and linear polymers with a matched contour length. Compared to BD simulations, single molecule experiments show quantitatively larger fluctuations, which could arise because experiments are performed on higher molecular weight polymers with stronger topological constraints. To this end, we have advanced the understanding of the effects of topological interactions and intermolecular HIs on the dynamics of semidilute ring-linear polymer blend solutions.
Nanoparticle dynamics in semidilute polymer solutions: Rings versus linear chains
Authors: Chen Renjie , Kotkar Shivraj B. , Poling-Skutvik Ryan , Howard Michael P. , Nikoubashman Arash , Conrad Jacinta C. , Palmer Jeremy C.
Published: June 2021

We study the dynamics of nanoparticles in semidilute solutions of ring and linear polymers using hybrid molecular dynamics–multiparticle collision dynamics simulations. The dynamics of the monomers, the polymer centers-of-mass, and the nanoparticles coincide for these two architectures for solutions of the same monomer concentration. The long time diffusivities of the nanoparticles follow the predictions of a polymer coupling theory [Cai et al., Macromolecules 44, 7853–7863 (2011)], suggesting that nanoparticle dynamics are coupled to segmental relaxations for both polymer architectures examined here. At intermediate time scales, the nanoparticle dynamics are characterized by subdiffusive exponents, which markedly deviate from coupling theory and closely follow those of the polymers. Instead, the nanoparticle dynamics are strongly coupled to the polymer center-of-mass motions for both architectures, rather than to their segmental dynamics. The presence of ring concatenations does not affect the long-time diffusivity of the nanoparticles but leads to a slight decrease in the subdiffusive exponents of the nanoparticles and the polymer center-of-mass.
Generating Genotype-Specific Aminoglycoside Combinations with Ceftazidime/Avibactam for KPC-Producing
Klebsiella pneumoniae
Authors: Huang Yanqin , Sokolowski Karol , Rana Amisha , Singh Nidhi , Wang Jiping , Chen Ke , Lang Yinzhi , Zhou Jieqiang , Kadiyala Neera , Krapp Fiorella , Ozer Egon A. , Hauser Alan R. , Li Jian , Bulitta Jürgen B. , Bulman Zackery P.
Published: June 2021

Antibiotic combinations, including ceftazidime/avibactam (CAZ/AVI), are frequently employed to combat KPC-producing
Klebsiella pneumoniae
(KPC-Kp), though such combinations have not been rationally optimized. Clinical KPC-Kp isolates with common genes encoding aminoglycoside-modifying enzymes (AMEs),
aac(6′)-Ib′
or
aac(6′)-Ib
, were used in static time-kill assays (
n
 = 4 isolates) and the hollow-fiber infection model (HFIM;
n
 = 2 isolates) to evaluate the activity of gentamicin, amikacin, and CAZ/AVI alone and in combinations.
Paleomagnetic dating of prehistoric lava flows from the urban district of Catania (Etna volcano, Italy)
Authors: Magli Andrea , Branca Stefano , Speranza Fabio , Risica Gilda , Siravo Gaia , Giordano Guido
Published: June 2021

Determining the ages of past eruptions of active volcanoes whose slopes were historically inhabited is vitally important for investigating the relationships between eruptive phenomena and human settlements. During its almost three-millennia-long history, Catania—the biggest city lying at the toe of Etna volcano—was directly impacted only once by the huge lava flow emplaced during the A.D. 1669 Etna flank eruption. However, other lava flows reached the present-day Catania urban district in prehistoric ages before the founding of the city in Greek times (729/728 B.C., i.e., 2679/2678 yr B.P.). In this work, the Holocene lava flows of Barriera del Bosco, Larmisi, and San Giovanni Galermo, which are exposed in the Catania urban district, were paleomagnetically investigated at 12 sites (120 oriented cores). Paleomagnetic dating was obtained by comparing flow-mean paleomagnetic directions to updated geomagnetic reference models for the Holocene. The Barriera del Bosco flow turns out to represent the oldest eruptive event and is paleomagnetically dated to the 11,234–10,941 yr B.P. and 8395–8236 yr B.P. age intervals. The mean paleomagnetic directions from the San Giovanni Galermo and Larmisi flows overlap when statistical uncertainties are considered. This datum, along with geologic, geochemical, and petrologic evidence, implies that the two lava flows can be considered as parts of a single lava field that erupted in a narrow time window between 5494 yr B.P. and 5387 yr B.P. The emplacement of such a huge lava flow field may have buried several Neolithic settlements, which would thus explain the scarce occurrence of archaeological sites of that age found below the town of Catania.
Septic arthritis of the acromioclavicular joint secondary to methicillin-resistantStaphylococcus aureusinfection
Authors: Cooper Blair , Obi Nnamdi Jonathan Chukwura , Cheng Kenneth
Published: June 2021

Septic arthritis of the acromioclavicular joint (ACJ) is a rare pathology with very few documented case reports available in the literature. In addition, ACJ septic arthritis secondary to methicillin-resistantStaphylococcus aureus(MRSA) is a rarer pathology with only two previously documented case reports in the medical literature to our knowledge. We present the case of a 46-year-old man who was diagnosed with a confirmed ACJ septic arthritis secondary to MRSA following admission to the local trauma and orthopaedic service at a district general hospital. We aim to give an insight into this pathology and highlight the importance of the relationship between orthopaedics and microbiology in optimising patient care, particularly in a period of rising rates of antimicrobial resistance.
Three atypical presentations of choriocarcinoma, occurring during and shortly after a coexistent viable pregnancy
Authors: du Fossé Nadia A. , Lutke Holzik E. Margo , de Kroon Cor H.
Published: June 2021

Gestational choriocarcinoma is a malignant tumour originating from the trophoblastic tissue that can arise during or after any type of pregnancy, but most of the time follows a molar pregnancy. Characteristic for this tumour is its rapid haematogenous spread to various organs, causing atypical presentations often attributable to metastatic disease. We review three cases that occurred during and shortly after a coexistent intrauterine pregnancy. The patient of Case 1 presented with neurological symptoms due to hypercalcaemia, in Case 2 there was initially suspicion of appendicitis and the third patient presented with acute respiratory insufficiency. This case series illustrates that, although highly effective chemotherapy is available, choriocarcinoma can be life-threatening and accurate diagnosis is challenging but critical.