bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental seismic performance assessment and numerical modelling of nonlinear inerter vibration absorber (IVA)‐equipped base isolated structures tested on shaking table
Authors: Pietrosanti Daniele , De Angelis Maurizio , Giaralis Agathoklis
Published: June 2021

In recent years, inerter vibration absorbers (IVAs), such as the tuned mass damper inerter (TMDI), attracted much attention in the literature for reducing seismic displacement demands of base isolated structures (BISs). Several theoretical studies reported reduced BIS seismic demands with increasing inertance endowed by a grounded inerter element, but adopted mostly idealized linear dynamical models. Herein, the potential of TMDI‐configured IVAs for seismic response reduction of BISs modelled as single‐mass structures is assessed under the combined effects of nonlinear inerter and structural behavior. To this aim, experimental data from a shaking table testing campaign are considered utilizing a custom‐built flywheel rack‐and‐pinion grounded inerter prototype with variable inertance, along with high damping rubber bearings in the isolation layer and in the BIS‐to‐absorber link. White noise excitation and an ensemble of six ground motions (GMs) with different frequency content are used in the tests for which bearings exhibit softening nonlinear behavior. Experimental results demonstrate improvement of BIS nonlinear seismic response in terms of displacement and base shear with increasing inertance for nonlinear and nonoptimally tuned IVAs. It is found though that the considered IVAs may be detrimental to BIS acceleration response depending on the GMs time‐varying frequency content signatures as captured by the continuous wavelet transform spectrogram. Finally, it is concluded that representing the inerter device by a simplified linear dissipative model as opposed to a nonlinear model with friction and gear backlash suffices to trace the BIS response with acceptable accuracy and, thus, can be used for optimal seismic TMDI design.
Proposal and validation of a design procedure for concentrically braced frames in the chevron configuration
Authors: Barbagallo Francesca , Bosco Melina , Marino Edoardo M. , Rossi Pier Paolo
Published: June 2021

In the recent past, several research studies have highlighted that the prescriptions reported in codes for the design of structures with concentric braces in the chevron configuration are often not effective in preventing yielding or buckling of non‐dissipative members and in ensuring collapse mechanisms characterised by uniform damage of braces. To investigate the reasons of these deficiencies, in this paper the seismic response of concentrically braced structures designed according to procedures reported in the literature and in the European seismic code is first examined. Then, a new design procedure is proposed, in which the innovative aspects are mainly related to the estimation of the bending moments in columns and to the formulation of requirements on the stiffness of braced beams and columns. The impact of the proposed procedure on the structural costs is computed on a large number of buildings characterised by different occupancy types and geometric properties. The seismic performance of these structures is evaluated by incremental nonlinear dynamic analysis and discussed at the achievement of the significant damage and near‐collapse limit states.
Cooperation in large‐scale human societies—What, if anything, makes it unique, and how did it evolve?
Authors: Powers Simon T. , van Schaik Carel P. , Lehmann Laurent
Published: June 2021

To resolve the major controversy about why prosocial behaviors persist in large‐scale human societies, we propose that two questions need to be answered. First, how do social interactions in small‐scale and large‐scale societies differ? By reviewing the exchange and collective‐action dilemmas in both small‐scale and large‐scale societies, we show they are not different. Second, are individual decision‐making mechanisms driven by self‐interest? We extract from the literature three types of individual decision‐making mechanism, which differ in their social influence and sensitivity to self‐interest, to conclude that humans interacting with non‐relatives are largely driven by self‐interest. We then ask: what was the key mechanism that allowed prosocial behaviors to continue as societies grew? We show the key role played by new social interaction mechanisms—change in the rules of exchange and collective‐action dilemmas—devised by the interacting individuals, which allow for self‐interested individuals to remain prosocial as societies grow.
Bringing social values to wildlife conservation decisions
Authors: Manfredo Michael J , Berl Richard EW , Teel Tara L , Bruskotter Jeremy T
Published: June 2021

Humans regularly exert a powerful influence on the survival and persistence of species, yet social‐science information is used only sporadically in conservation decisions. Using data obtained from a survey of 46,894 US residents, we developed and applied a spatially explicit “sociocultural index” to inform decision making through an understanding of public values toward wildlife. The classification is defined by opposing values of mutualism and domination, which have been previously shown to be highly predictive of attitudes on a wide range of policy issues. We developed state and county maps that can be used to represent public interests in policy decisions and inform management actions that target human behavior, such as education. To illustrate, we present findings indicating a supportive social context for gray wolf (Canis lupus) reintroduction in Colorado, an issue voted on and passed through a November 2020 citizen ballot initiative. Although the results are particularly relevant for the US, the technique is broadly applicable and its expansion is encouraged to better account for human factors in conservation decisions globally.
Managing animal movement conserves predator–prey dynamics
Authors: Keim Jonah L , DeWitt Philip D , Wilson Steven F , Fitzpatrick J Jeremy , Jenni Noemie S , Lele Subhash R
Published: June 2021

Anthropogenic landscape change can lead to novel interactions among species with consequences for predator–prey dynamics. Population responses of predators and prey vary according to species abundance, movement, and distribution. Although conservation often involves managing species abundance, culling predators to benefit vulnerable prey is socially, ethically, and ecologically tenuous. We conducted a before–after control–impact experiment to test how well mitigations designed to disrupt animal movement reduce encounters between endangered caribou (Rangifer tarandus) and their predators in a human‐modified landscape. Using camera traps, we quantified coincident habitat use by predators and prey. By deploying obstacles to disrupt ease of movement on human developments, we reduced the ratio of wolf (Canis lupus)–caribou encounters by 85% and reduced the ratio of black bear (Ursus americanus)–caribou encounters by 60%, without removing predators. By managing animal movements that regulate predator–prey encounters, risk to endangered species can be reduced without the disruptive trophic effects caused by intensive carnivore removals.
Throughfall and stemflow are major hydrologic highways for particulate traffic through tree canopies
Authors: Van Stan John T , Ponette‐González Alexandra G , Swanson Travis , Weathers Kathleen C
Published: June 2021

For one‐third of Earth’s land surface, precipitation passes through tree canopies (as throughfall or stemflow) before entering watersheds. Over a century of research has described fluxes of water and solutes along these “hydrologic highways”, yet little is known about their “traffic” – that is, the organisms and nonliving particulates frequently discarded from water samples after filtration in the lab. A comprehensive understanding of the composition of sub‐canopy precipitation is necessary to estimate the total nutrient and pollutant inputs to watersheds for redistribution downstream, as well as to systematically investigate precipitation effects on organismal exchanges along the atmosphere–plant–soil continuum. Here, we review current concepts and research showing that the hydrologic highways from tree canopies to soil carry ecologically relevant quantities of biologic (viruses, microbes, microfauna, and meiofauna) and abiotic particulates. Their fate may have important consequences for the biogeochemistry and biodiversity of terrestrial systems.
Expected demographic and genetic declines not found in most zoo and aquarium populations
Authors: Che‐Castaldo Judy , Gray Steven M , Rodriguez‐Clark Kathryn M , Schad Eebes Kristine , Faust Lisa J
Published: June 2021

Since the 1980s, animals in accredited zoos and aquariums have been managed as populations through cooperative breeding, with a goal of maintaining ex situ populations that are as demographically viable and genetically diverse as possible. Here, we provide what we believe to be the first large‐scale assessment of whether cooperative breeding programs are achieving this goal over time. Using a comprehensive dataset spanning nearly 20 years and encompassing more than 400 ex situ vertebrate populations, we applied Bayesian hierarchical modeling to quantify changes in seven population metrics over time. Instead of the general declines expected for small and often closed populations like those in zoos and aquariums, we found no change in the demographic and genetic characteristics of the majority of these populations. Our results indicate that while some zoo and aquarium populations are currently unsustainable, cooperative management is helping to slow or prevent declines in the health of many ex situ populations.
New insights on the petroleum migration and accumulation in the basal conglomerate reservoir of Cretaceous Qingshuihe Formation of Yongjin area, Central Junggar Basin
Authors: Wang Yue , Chang Xiangchun , Liu Zhongquan , Shi Bingbing , Zhang Pengfei , Xu Youde
Published: June 2021

The Junggar Basin is one of the largest and most petroliferous superimposed petroleum basins in China. This study focussed on the characteristics of the unconformity between the Jurassic and Cretaceous (J/K) and its influence on hydrocarbon accumulation in the Yongjin area, Junggar Basin. Based on the seismic reflection characteristics and wireline well logging response, we identified the structure of the unconformity, which consists of three layers: the basal conglomerate layer, weathered clay layer, and semi‐leached layer. Geochemical studies show that the crude oils of the Lower Cretaceous Qingshuihe (K1q) Formation in the Yongjin area are mainly derived from Permian source rocks and partly from Cretaceous source rocks. The abnormally high value of acoustic time and the low value of resistivity of mudstone indicate that the overpressure condition is pervasive in the Yongjin area and may act as the driving force for the vertical migration of hydrocarbon‐containing palaeo‐fluids. The poor sealing ability of the weathered clay layer of the unconformity between the Jurassic and Cretaceous (J/K) and the high abnormal overpressure indicate that the petroleum from Permian source rocks may break through the sealing of the weathered clay layer and migrate upward to the Cretaceous conglomerate to accumulate. In addition, the combination of faults, sheet sand bodies, and unconformities constitutes a three‐dimensional petroleum migration pathway. The evolution of the Che‐Mo palaeo‐uplift also affected the formation of source rocks and petroleum migration. Accordingly, the hydrocarbon accumulation model of the Cretaceous in the Yongjin area indicated that Late Palaeogene is the first accumulation period. Permian source rocks have entered a mature to high‐mature stage, where a large amount of generated oil and gas migrated along faults and unconformities and accumulated in the braided river channel sand bodies of the K1q Formation. The second accumulation period was the Neogene. The basin experienced a regional tilt leading to a south‐inclined stratum. The oil and gas migrated upwards along the Late Hercynian deep reverse fault (Carboniferous–Permian) and then passed through the shallow faults and migrated to the bottom sandstone of Cretaceous reservoirs.
Problems in the home and community‐based long‐term care for the elderly in China: A content analysis of news coverage
Authors: Wang Kun , Ke Yongjian , Sankaran Shankar , Xia Bo
Published: June 2021

Purpose

The purpose of this paper is to identify the issues that limited the supply of home and community‐based Long‐Term‐Care (LTC) for the elderly, offer essential insights into the sustainable development of China's LTC.

Design/methodology/approach

A content analysis of news coverage on 12 major portals in China has been conducted to identify the issues.

Findings

The results demonstrate that there are 12 significant problems in the supply of home and community‐based LTC for the elderly. For the service providers, the lack of qualified LTC professionals, limited service types/low service quality and unrealised integrated care, lack of steady profit patterns are the three major problems. The deficiencies of the LTC system and the lack of incentive policies and legislation for private investors’ participation are the two major problems faced by the government. The public is confronted with a shortage of home and community support resources and unable to adapt to a change due to their mindsets.

Practical implications

The issues identified in this paper can not only provide some opportunities to various stakeholders in this area but also offer insights into the sustainable development of China's LTC.

Originality/value

The findings presented in this paper provide the means to understand the home and community‐based LTC market in China for private investors and government, which will help to promote the cooperation between the two.
Characteristics and treatment of elemental mercury intoxication: A case series
Authors: Johnson‐Arbor Kelly , Tefera Eshetu , Farrell John
Published: June 2021

Background and aims

Elemental mercury toxicity is a rare condition which can be difficult to diagnose due to its nonspecific signs and symptoms. The purpose of this investigation is to describe the presenting characteristics and treatment of adult and pediatric patients with elemental mercury poisoning.

Methods

A retrospective review was performed in six patients with elemental mercury exposure or intoxication who were treated in an outpatient medical toxicology clinic. Clinical signs and symptoms, laboratory assessments, and public health responses were reviewed.

Results

Headache, anorexia, rash, and personality changes were commonly reported symptoms in pediatric patients; the adult patients were asymptomatic or reported signs and symptoms included myalgias, tremors, and hypertension. Delays in diagnosis were common. Symptomatic patients had 24‐hour urine mercury concentrations greater than 20 mcg/L. Treatment, including removal from the exposure source as well as chelation with dimercaptosuccinic acid, resulted in resolution of signs and symptoms within 6 months of diagnosis.

Conclusion

The evaluation and treatment of patients with suspected elemental mercury poisoning frequently require a multidisciplinary approach including medical toxicologists and public health officials. A heightened awareness of the clinical presentations of this condition, as well as early identification and removal of patients from the source of exposure and consideration of chelation therapy, can result in accelerated patient recovery.
How to ask: Surveying nursing directors of nursing homes
Authors: Williams Jessica A.R. , Vriniotis Mary G. , Gundersen Daniel A. , Boden Leslie I. , Collins Jamie E. , Katz Jeffrey N. , Wagner Gregory R. , Sorensen Glorian
Published: June 2021

Background and Aims

Nursing home research may involve eliciting information from managers, yet response rates for Directors of Nursing have not been recently studied. As a part of a more extensive study, we surveyed all nursing homes in three states in 2018 and 2019, updating how to survey these leaders effectively. We focus on response rates as a measure of non‐response error and comparison of nursing home's characteristics to their population values as a measure of representation error.

Methods

We surveyed Directors of Nursing or their designees in nursing homes serving adult residents with at least 30 beds in California, Massachusetts, and Ohio (N = 2389). We collected contact information for respondents and then emailed survey invitations and links, followed by three email reminders and a paper version. Nursing home associations in two of the states contacted their members on our behalf. We compared the response rates across waves and states. We also compared the characteristics of nursing homes based on whether the response was via email or paper. In a multivariable logit regression, we used characteristics of the survey and the nursing homes to predict whether their DON responded to the survey using adjustments for multiple comparisons.

Results

The response rate was higher for the first wave than for the second (30% vs 20.5%). The highest response rate was in Massachusetts (31.8%), followed by Ohio (25.8%) and California (19.5%). Nursing home characteristics did not vary by response mode. Additionally, we did not find any statistically significant predictors of whether a nursing home responded.

Conclusion

A single‐mode survey may provide a reasonably representative sample at the cost of sample size. With that said, however, switching modes can increase sample size without potentially biasing the sample.
Effects of mixed physical barrier on residual saltwater removal and groundwater discharge in coastal aquifers
Authors: Gao Mingpeng , Zheng Tianyuan , Chang Qinpeng , Zheng Xilai , Walther Marc
Published: June 2021

Physical barriers are widely used to control seawater intrusion (SWI). Amongst different kinds of physical barriers, mixed physical barriers (MPBs) are shown to be an effective approach to prevent SWI. However, the system may hinder the discharge of fresh groundwater and the removal of residual saltwater trapped in the inland aquifers of MPBs. Herein, using the validated numerical model, for the first time, we investigated the dynamics of residual saltwater and groundwater discharge after the installation of MPBs. For examining the applicability of MPB and its response to structural variations and hydraulic gradient, the comparison with traditional physical barriers and sensitivity analysis was also carried out. The MPB increased the mixing area of freshwater and saltwater at the beginning of the removal process, resulting in the reduction of the saltwater wedge length (RL) by 74.6% and the removal of total salt mass (RM) by 62.6% within the 4% of the total removal time. Meanwhile, the groundwater discharge (Q') rose rapidly after a sharp decline from 100% to 40% in the first stage. As the residual saltwater wedge was retreated, the mixing intensity and removal efficiency decreased substantially in the second stage. Similarly, Q' raised with a declining rate at this stage. The removal efficiency was positively correlated with wall depth and hydraulic gradient and there were optimal distance of the middle spacing and height of lower dam to reach the highest efficiency. The groundwater discharge reduced monotonously with the increase of dam height and wall depth as well as the decrease of barrier spacing and hydraulic gradient. Under certain conditions, the efficiency of MPB in removing residual saltwater could be 40%–100% and 0%–56% higher than that of traditional subsurface dam and cutoff wall, respectively. The laboratory scale conclusions provide valuable physical insight for the real field applications regarding dynamic mechanism and regularity. These findings will always help decision makers choose proper engineering measures and protect groundwater resources in coastal areas.
A deep learning framework for glaucoma detection based on robust optic disc segmentation and transfer learning
Authors: Natarajan Deepa , Sankaralingam Esakkirajan , Balraj Keerthiveena , Karuppusamy Selvakumar
Published: June 2021

Glaucoma is a common ocular disorder, inflicting blindness in millions of people, early detection of which can reduce adverse outcomes. This paper presents a two‐stage deep learning framework UNet‐SNet, for glaucoma detection. Initially, each fundus image is segmented into GMM super pixels and the Region of Interest (RoI) is separated by Cuckoo Search Optimization (CSO). In the first stage, a regularized UNet is trained with RoIs for OD segmentation. In the second stage, a SqueezeNet is fine‐tuned with deep features of the ODs to discriminate fundus images into glaucomotousor Normal. The UNet is trained and tested with the RIGA and RIM‐ONEv2 datasets, achieving 97.84% and 99.85% accuracies respectively. The classifier is trained with the ODs segmented from the RIM‐ONEv2 dataset and tested with ACRIMA, Drishti‐GS1 and RIM‐ONEv1 datasets accomplishing 99.86%, 97.05% and 100% accuracies respectively. Performance evaluations and complexity analyses with state‐of‐the‐art systems demonstrate the superiority of the proposed model.
Management of the competition horse – know the client, know the sport, know the rules
Authors: Elliott Christopher
Published: June 2021

Background: Managing the demands of actively competing sport horses can be challenging for veterinarians. Finding the right balance between short‐term athletic goals and long‐term health and wellbeing of the horse can at times be difficult. Understanding your client's goals, aspirations and the athletic expectations of their equine partner is essential for successful management of the sport horse. This, coupled with knowledge of the chosen equestrian sport and familiarity with the rules and regulations, will greatly improve any veterinarian's ability to manage actively competing sport horses.

Aim of the article: This article aims to assist veterinarians treating sport horses by highlighting some of the important equestrian rules and regulations. It also discusses some approaches to creating a successful veterinary‐client relationship.
Nanodiamond‐chitosan functionalized hernia mesh for biocompatibility and antimicrobial activity
Authors: Saha Tanushree , Houshyar Shadi , Sarker Satya Ranjan , Pyreddy Suneela , Dekiwadia Chaitali , Nasa Zeyad , Padhye Rajiv , Wang Xin
Published: June 2021

Polypropylene (PP) mesh is most commonly used for the treatment of hernia and pelvic floor construction. However, some of the patients have a few complications after surgery due to the rejection or infection of the implanted meshes. The poor biocompatibility of PP mesh, low wettability results in poor cell attachment/proliferation and restricts the loading of antibacterial agent, leading to a slow healing process and high risk of infection after surgery. Here in this study, a new technique has been employed to develop a novel antimicrobial and biocompatible PP mesh modified with bioactive chitosan and functionalized nanodiamond (FND) for infection inhibition and acceleration of the healing process. An oxygen plasma treatment PP mesh was used then chitosan was strongly attached to the surface of the PP fibers. Subsequently, FND as an antibacterial agent was loaded into the chitosan modified PP fiber to provide desired antibacterial functions. The meshes were characterised with XRD, FTIR, SEM, EDX, water contact angle, confocal, and optical microscopy. The modified PP mesh with chitosan and FND showed a significant increase in its hydrophilicity and L929 fibroblast cell attachment. Furthermore, the modified mesh exhibited great antibacterial efficiency against Escherichia coli. Therefore, the newly developed technique to modify PP mesh could be a promising technique to generate a biocompatible PP mesh to accelerate the healing process and reduce the risk of infection after surgery.
Proximity with limited humanity: How hosting a tent city impacted college students' perceptions of individuals experiencing homelessness
Authors: Tausen Brittany M. , Charleson Mary , Fingerhut Lea
Published: June 2021

The current manuscript assessed the impact of a community intervention—hosting a government‐sanctioned homeless encampment—on perceptions of individuals experiencing homelessness. College students' perceptions of individuals experiencing homelessness were collected before and after a tent city resided on campus. Perceptions were assessed utilizing a measure of dehumanization that probed the presumed importance of physiological and psychological needs. Data about contact with individuals experiencing homelessness were also collected. Hosting a tent city did not improve community‐wide perceptions of individuals experiencing homelessness. For a subset of participants who explicitly mentioned interactions with tent city members, awareness of the importance of physiological needs increased. Assessments of intergroup contact during hosting did not moderate changes in perceptions, though contact prior to hosting did have a modest impact. Specifically, students who had the fewest prior interactions were more likely to show improved perceptions of middle‐level need (e.g., love and belonging) importance. There was no evidence to suggest any enhancements in perceptions of high‐level needs (e.g., feeling independent and respected). Contact that organically occurs when a community hosts a tent city has limited potential to enhance markers of humanness. Implications for the contact hypothesis and recommendations for future hosting sites are discussed.
Non‐alcoholic fatty liver disease and sarcopenia additively increase mortality: a Korean nationwide survey
Authors: Moon Joon Ho , Koo Bo Kyung , Kim Won
Published: June 2021

Background

Sarcopenia is an independent risk factor not only for advanced‐stage non‐alcoholic fatty liver disease (NAFLD) but also for mortality. We investigated the association of sarcopenia and/or NAFLD with mortality among the Korean general population.

Methods

Individuals aged 35–75 years without any history of cancer, ischaemic heart disease, ischaemic stroke, or secondary causes of chronic liver disease were selected from the Korean National Health and Nutrition Examination Surveys from 2008 to 2015. Their mortality data until December 2018 were retrieved from the National Death Registry. NAFLD and sarcopenia were defined by hepatic steatosis index and appendicular skeletal muscle mass divided by body mass index (BMI), respectively.

Results

A total of 28 060 subjects were analysed [mean age, 50.6 (standard error, 0.1) years, 48.2 (0.3) % men]; the median follow‐up duration was of 6.8 (interquartile range, 4.8, 8.4) years. NAFLD predicted mortality after adjustment for age, sex, BMI, hypertension, dyslipidaemia, and smoking (HR 1.32, 95% CI 1.03–1.70), but this prediction lost its statistical significance after additional adjustment for diabetes mellitus. In contrast, NAFLD with advanced fibrosis independently increased the risk of mortality after adjustment for all covariates (HR 1.68, 95% CI 1.02–2.79). Stratified analysis revealed that NAFLD and sarcopenia additively increased the risk of mortality as an ordinal scale (HR 1.46, 95% CI 1.18–1.81, P for trend = 0.001). The coexistence of NAFLD and sarcopenia increased the risk of mortality by almost twice as much, even after adjustment for advanced fibrosis (HR 2.18, 95% CI 1.38–3.44).

Conclusions

Concurrent NAFLD and sarcopenia conferred a two‐fold higher risk of mortality. The observation that NAFLD and sarcopenia additively increase mortality suggests that risk stratification would be helpful in predicting mortality among those with metabolic derangement.
Solventless transacetalization of solketal over Amberlyst catalysts into valuable bio‐based chemicals
Authors: Noor Armylisas Abu H , Hoong Seng S , Tuan Noor Maznee Tuan I , Yeong Shoot K , Mohammat Mohd F
Published: June 2021

BACKGROUND

In addition to being a greener synthetic approach, the production of value‐added chemicals from bio‐based glycerol is highly appealing owing to its nontoxicity, renewability and availability. The current work reports solventless transacetalization of solketal with benzaldehyde in the presence of heterogeneous Amberlyst® catalysts (A15 dry, A15 wet, A36 and A46).

RESULTS

Effects of several reaction parameters on the transacetalization of solketal also were investigated and optimized to attain maximum conversion and yield. This reaction, however, is accompanied by concurrent hydrolysis of solketal to form the side product glycerol. Of all solid acid catalysts investigated, A15 dry (10 wt%) gave the highest conversion (88%) under optimized reaction conditions of 60 °C, 5:1 (solketal/benzaldehyde) and 30 min duration. The A15 dry is reusable and recyclable with only 8% reduction in conversion after five consecutive cycles. The approach was extended to other aldehydes including furfural and phenylacetaldehyde to produce, respectively, a highly value‐added fuel additive intermediate and hyacinth fragrance.

CONCLUSION

The transacetalization of solketal with less reactive aldehyde into cyclic glycerol acetal was achieved in an efficient, feasible and green manner. A15 was the most reactive catalyst of all Amberlyst® catalysts investigated. This approach also provided effective utilization of waste of biodiesel production – glycerol – for transformation into value‐added products. © 2021 Society of Chemical Industry (SCI).
Pre and postnatal diagnosis of a third branchial cleft cyst by sonography and magnetic resonance imaging with three‐dimensional virtual reconstruction
Authors: Castro Pedro Teixeira , Werner Heron , Fazecas Tatiana , Matos Ana Paula , Maia Fernando , de Mello Paulo Pires , Araujo Júnior Edward
Published: June 2021

Branchial cleft cysts (BCCs) are common causes of cervical tumors in children and adulthood; however, prenatal diagnosis of BCC is rare. In neonates, these cysts can suddenly increase in size, causing airway obstruction and becoming a life‐threatening condition. In this case report, we describe the prenatal diagnosis of a third BCC at the 25th week of pregnancy using ultrasound, magnetic resonance imaging, and three‐dimensional virtual models, as well as the perinatal outcomes of this rare condition.
Obesity and cholangiocarcinoma: A review of epidemiological and molecular associations
Authors: Osataphan Soravis , Mahankasuwan Treerat , Saengboonmee Charupong
Published: June 2021

Cholangiocarcinoma (CCA) is a malignancy of bile duct epithelium, and its incidence is increasing globally. Numerous factors are reported associated with an increased risk of CCA and vary among populations across different areas. Obesity is a major, worldwide public health problem that leads to several complications and is associated with increased cancer risk. Although several epidemiological studies have shown that obesity is likely associated with the increased risk of CCA, this association might be limited to Western countries. Multiple hormones, cytokines, and metabolite perturbations in obese states have been shown to enhance tumorigenicity and metastasis potentials. Understanding the biological linkage of obesity to CCA might lead to novel prevention and therapeutic approaches to CCA treatment. This review summarizes the current evidence and highlights the knowledge gaps regarding the relationship between obesity and CCA from epidemiological and molecular perspectives.
Machine Learning‐Based Multiparametric Magnetic Resonance Imaging Radiomic Model for Discrimination of Pathological Subtypes of Craniopharyngioma
Authors: Huang Zhou‐San , Xiao Xiang , Li Xiao‐Dan , Mo Hai‐Zhu , He Wen‐Le , Deng Yao‐Hong , Lu Li‐Jun , Wu Yuan‐Kui , Liu Hao
Published: June 2021

Background

Preoperative, noninvasive discrimination of the craniopharyngioma subtypes is important because it influences the treatment strategy.

Purpose

To develop a radiomic model based on multiparametric magnetic resonance imaging for noninvasive discrimination of pathological subtypes of craniopharyngioma.

Study Type

Retrospective.

Population

A total of 164 patients from two medical centers were enrolled in this study. Patients from the first medical center were divided into a training cohort (N = 99) and an internal validation cohort (N = 33). Patients from the second medical center were used as the external independent validation cohort (N = 32).

Field Strength/Sequence

Axial T1‐weighted (T1‐w), T2‐weighted (T2‐w), contrast‐enhanced T1‐weighted (CET1‐w) on 3.0 T or 1.5 T magnetic resonance scanners.

Assessment

Pathological subtypes (squamous papillary craniopharyngioma and adamantinomatous craniopharyngioma) were confirmed by surgery and hematoxylin and eosin staining. Optimal radiomic feature selection was performed by SelectKBest, the least absolute shrinkage and selection operator algorithm, and support vector machine (SVM) with a recursive feature elimination algorithm. Models based on each sequence or combinations of sequences were built using a SVM classifier and used to differentiate pathological subtypes of craniopharyngioma in the training cohort, internal validation, and external validation cohorts.

Statistical Tests

The area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic performance of the radiomic models.

Results

Seven texture features, three from T1‐w, two from T2‐w, and two from CET1‐w, were selected and used to construct the radiomic model. The AUC values of the radiomic model were 0.899, 0.810, and 0.920 in the training cohort, internal and external validation cohorts, respectively. The AUC values of the clinicoradiological model were 0.677, 0.655, and 0.671 in the training cohort, internal and external validation cohorts, respectively.

Data Conclusion

The model based on radiomic features from T1‐w, T2‐w, and CET1‐w has a high discriminatory ability for pathological subtypes of craniopharyngioma.

Level of Evidence

4

Technical Efficacy

2
Transcutaneous Mediastinal Ultrasonography for Lymphadenopathy in Children
Authors: Bhalla Deeksha , Sinha Pallavi , Naranje Priyanka , Jana Manisha , Bhalla Ashu S. , SK Pritviraj , Gupta Arun K.
Published: June 2021

Ultrasonography (US) forms the mainstay of imaging in children; however, in the chest, its use has traditionally been limited to evaluation of pleural pathology. US techniques such as endobronchial and endoscopic ultrasound, which are commonly used for detection of mediastinal lymphadenopathy are invasive, aerosol generating, and often require sedation. Transcutaneous mediastinal sonography (TMUS) offers a useful alternative, which is easier to perform and overcomes these limitations. In this review, we summarize the technique, as well as imaging appearances of lymph nodes on TMUS. We also list common problems faced by operators and suggest troubleshooting methods for these.
Tuberculosis in the Head and Neck: Changing Trends and Age‐Related Patterns
Authors: Gehrke Thomas , Hackenberg Stephan , Tecle Nyat , Hagen Rudolf , Scherzad Agmal
Published: June 2021

Objective

To evaluate changing trends in patient collectives, age‐related patterns of manifestation, and diagnostic pathways of patients with extrapulmonary head and neck tuberculosis (TB), and to provide strategies to fasten diagnosis in these patients.

Study design

Case control study.

Methods

A 10‐year retrospective analysis of 35 patients diagnosed with extrapulmonary TB in the head and neck at a tertiary university institution from 2009 to 2019, with special focus on the influence of the patient's age on consideration of TB and clinical patterns.

Results

The vast majority of patients younger than 40 years had their origin in countries with high TB burden (P = .0003), and TB was considered very early as a differential diagnosis (P = .0068), while most patients older than 40 years were domestic citizens initially suspected for a malignancy, who more often had an underlying immunosuppressive condition (0.0472). Most frequent manifestations in both groups were the lymph nodes, larynx, and oropharynx. Surprisingly, no differences in the rates of open TB or history of TB infection in the family anamnesis were found.

Conclusion

The two groups of patients found most often are younger patients migrating from regions with high TB burden and elderly domestic patients suffering from immunosuppressive conditions, with the latter often being misdiagnosed as malignancies. TB remains an important but difficult differential diagnosis, due to the initially unspecific symptoms and the great variety in the presentation of manifestations in the head and neck.

Level of Evidence

4 Laryngoscope, 131:2701–2705, 2021
Impact of increasing carbon dioxide on dinitrogen and carbon fixation rates under oligotrophic conditions and simulated upwelling
Authors: Singh Arvind , Bach Lennart T. , Löscher Carolin R. , Paul Allanah J. , Ojha Narendra , Riebesell Ulf
Published: June 2021

Dinitrogen (N2) fixation is a major source of bioavailable nitrogen to oligotrophic ocean communities. Yet, we have limited understanding how ongoing climate change could alter N2 fixation. Most of our understanding is based on short‐term laboratory experiments conducted on individual N2‐fixing species whereas community‐level approaches are rare. In this longer‐term in situ mesocosm study, we aimed to improve our understanding on the role of rising atmospheric carbon dioxide (CO2) and simulated deep water upwelling on N2 and carbon (C) fixation rates in a natural oligotrophic plankton community. We deployed nine mesocosms in the subtropical North Atlantic Ocean and enriched seven of these with CO2 to yield a range of treatments (partial pressure of CO2, pCO2 = 352–1025 μatm). We measured rates of N2 and C fixation in both light and dark incubations over the 55‐day study period. High pCO2 negatively impacted light and dark N2 fixation rates in the oligotrophic phase before simulated upwelling, while the effect reversed in the light N2 fixation rates in the bloom decay phase after added nutrients were consumed. Dust deposition and simulated upwelling of nutrient‐rich deep water increased N2 fixation rates and nifH gene abundances of selected clades including the unicellular diazotrophic cyanobacterium clade UCYN‐B. Elevated pCO2 increased C fixation rates in the decay phase. We conclude that elevated pCO2 and pulses of upwelling have pronounced effects on diazotrophy and primary producers, and upwelling and dust deposition modify the pCO2 effect in natural assemblages.
Thermal acclimation influences the growth and toxin production of freshwater cyanobacteria
Authors: Layden Tamara J. , Kremer Colin T. , Brubaker Delaney L. , Kolk Maeve A. , Trout‐Haney Jessica V. , Vasseur David A. , Fey Samuel B.
Published: June 2021

Understanding how altered temperature regimes affect harmful cyanobacterial bloom formation is essential for managing aquatic ecosystems amidst ongoing climate warming. This is difficult because algal performance can depend on both current and past environments, as plastic physiological changes (acclimation) may lag behind environmental change. Here, we investigate how temperature variation on sub‐weekly timescales affects population growth and toxin production given acclimation. We studied four ecologically important freshwater cyanobacterial strains under low‐ and high‐nutrient conditions, measuring population growth rate after acclimation and new exposure to a range of temperatures. Cold‐acclimated populations (15.7°C) outperformed fully acclimated populations (held in constant conditions) across 65% of thermal environments, while hot‐acclimated populations (35.7–42.6°C) underperformed across 75% of thermal environments. Over a 5‐day period, cold‐acclimated Microcystis aeruginosa produced ~2.5‐fold more microcystin than hot‐acclimated populations experiencing the same temperature perturbation. Our results suggest that thermal variation and physiology interact in underappreciated ways to influence cyanobacterial growth, toxin production, and likely bloom formation.
Synergistic effect of binary systems of nanostructured MoS2/SiO2 and GO/SiO2 as additives to coconut oil‐derived grease: Enhancement of physicochemical and lubrication properties
Authors: Rawat Sooraj Singh , Harsha A. P. , Khatri Om P.
Published: June 2021

The present work addresses the use of synergistic blends of two different types of nanomaterials (spherical particles and lamellar sheets) as additives for coconut oil‐based grease formulation to provide the energy‐efficient and sustainable alternative to conventional grease. The spherical SiO2 nanoparticles are separately blended with 2D lamellar sheets of MoS2 and graphene oxide (GO) in variable ratio and probed their synergistic effects for enhancement of physicochemical and lubrication properties. The SiO2 nanoparticles, MoS2, and GO nanosheets are prepared by modified sol–gel, hydrothermal reduction, and Hummer's methods, respectively. The 0.05 wt% nanomaterials blends of MoS2/SiO2 (30:70) and GO/SiO2 (50:50) as optimised doses furnished the maximum reduction in the friction and wear. The combination of rolling friction and low shear properties using the synergistic blend of the spherical nanoparticles (SiO2) and nanosheets (MoS2 and GO) showed significant improvement in tribological properties. The optimised blends of nanoadditives, that is, MoS2/SiO2 and GO/SiO2 conserved the energy by 20% and 19%, respectively. These findings suggest that the use of synergistic blends of variable nanomaterials to vegetable oil‐based lubricants can pave a direction for new generation lubricant formulation, where environmental sustainability and energy conservation are on prime importance.
Synthesis, Optimal Fabrication, and Physico‐Mechanical Property Evaluation of PCL‐b‐PLLA Diblock Copolymer‐Based Nanoscale Roughness Textured Electrospun Mats
Authors: Sharma Deepika , Goel Shubhra , Jacob Josemon , Satapathy Bhabani K.
Published: June 2021

Poly(ɛ‐caprolactone)‐block‐poly(L‐lactide) (PCL‐b‐PLLA) diblock copolymer and its electrospun mats (EMs) are characterized for their microstructural, thermal, and physico‐mechanical properties. The EMs of synthesized copolymer exhibiting the optimal level of average fiber diameter (Co‐FD) and diameter variation (Co‐SD) are obtained following Taguchi's design of experiments (DOE). Electrospinning process parameters such as solution concentration, DMF content in CF/DMF solvent mixture, and applied voltage are varied at three different levels (L9). Analysis of variance (ANOVA) indicated DMF content to be the major influencing factor on FD and SD of EMs with ∼95% confidence. Regression model indicated ∼88% accuracy in predicting the FD of the copolymer‐based EMs. The physico‐mechanical properties of the optimized EMs are evaluated vis‐à‐vis the influence of FD and SD on the mechanical properties. Atomic force microscopy revealed solvent evaporation induced radial inconsistencies, desirable in terms of nanoscale surface roughness, which is higher for Co‐SD (∼600 nm) than in Co‐FD (∼400 nm). The swelling and weight loss showed marked improvement in PCL‐b‐PLLA based EMs reiterating the possibility of their enhanced compatibility as biomedical materials.
Microporous Hyper‐Cross‐Linked Polymers with High and Tuneable Content of Pyridine Units: Synthesis and Application for Reversible Sorption of Water and Carbon Dioxide
Authors: Hašková Alena , Bashta Bogdana , Titlová Štěpánka , Brus Jiří , Vagenknechtová Alice , Vyskočilová Eliška , Sedláček Jan
Published: June 2021

New hyper‐cross‐linked porous organic polymers (POPs) with a high content of pyridine segments (7.86 mmol pyridine g−1), and a micro/mesoporous texture are reported. The networks are achieved by the chain‐growth homopolymerization of 2,6‐ and 3,5‐diethynylpyridines. The pyridine segments form links interconnecting the polyacetylene main chains in these networks. The content of pyridine segments in the networks can be tuned by copolymerizing diethynylpyridines with 1,3‐diethynylbenzene. The pyridine rings in the networks serve as base and hydrophilic centers for the sorption of CO2 and water. The homopolymer pyridine networks are highly efficient in the low‐pressure adsorption/desorption of CO2. This sorption mode is promising for the postcombustion removal of CO2 from the fuel gas. The poly(3,5‐diethynylpyridine) network exhibits high efficiency in capturing and releasing water vapor (determined capacity 376 mg g−1 at 298 K and relative humidity (RH) = 90% is one of the highest values reported for POPs) and is a promising material for the cyclic water harvesting from air. The reported networks are characterized by 13C cross‐polarization magic angle spinning NMR, thermogravimetric analysis, and N2 adsorption/desorption and their efficiency in CO2 and H2O capturing is discussed in relation to the content and type of incorporated pyridine segments.
In vivo CRISPR–Cas9 knockout screening using quantitative PCR identifies thymosin beta‐4 X‐linked that promotes diffuse‐type gastric cancer metastasis
Authors: An Hyeok‐Won , Kim Si‐You , Kwon Jong‐Wan , Seok Sang‐Hyuk , Woo Sang‐Ho , Kim Dae‐Yong , Park Jun Won
Published: June 2021

Gastric cancer (GC) is histologically classified into intestinal‐type gastric cancer (IGC) and diffuse‐type gastric cancer (DGC), and the latter is poorly differentiated and highly metastatic. In this study, using quantitative real‐time polymerase chain reaction, we described a complete protocol for in vivo CRISPR–Cas9‐based knockout screening of essential genes for DGC metastasis. We functionally screened 30 candidate genes using our mouse DGC models lacking Smad4, p53, and E‐cadherin. Pooled knockout mouse DGC cells were transplanted into a spleen of syngeneic immunocompetent mice to study clonal advantages in context of a complex process of liver metastasis. Tmsb4x (thymosin beta‐4 X‐linked), Hmox1, Ifitm3, Ldhb, and Itgb7 were identified as strong candidate genes that promote metastasis. In particular, Tmsb4x enhanced DGC metastasis and stomach organoid‐generated tumor growth in in vivo transplantation models. Tmsb4x promoted tumor clonogenicity and anoikis resistance. In situ hybridization analysis showed that Tmsb4x is highly expressed in E‐cadherin‐negative mouse DGC models compared with mouse IGC and intestinal cancer models. E‐cadherin deficiency also increased Tmsb4x expression in stomach organoids via Wnt signaling activation. Collectively, these results demonstrate that Tmsb4x promotes DGC metastasis. In addition, this experimental system will aid in the identification of novel target genes responsible for DGC metastasis.