bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cavitation phenomenon in mechanical prosthetic valves: Not only microbubbles
Authors: Vriz Olga , Arshi Fatma , Ahmed Mawada , Alhumaid Mohammed , Galzerano Domenico , Emmanual Shisamma , Kinsara Abdulhalim J. , Aladmawi Mohammed , Alamro Bandar , Alshahid Maie , Pedrizzettid Gianni 
Published: May 2020

AbstractIntroductionMicrobubbles (MBs) or cavitation is high‐velocity, echo‐bright findings present during the closing or opening of a mechanical valve (MVP). Cavitation bubble growth or gas emboli are less frequently described. We evaluated the hemodynamic parameters involved in the formation of gas emboli and the impact of gas emboli on requests for additional investigations.Methods and ResultsTransthoracic echocardiographic studies (TTE) of 57 patients (31 males, mean age 46.8 ± 13.8 years) with gas emboli were evaluated after heart valve replacement surgery. The majority (72%, n = 42) had a mitral or combined mitral/aortic MVP, with 28% (n = 16) an aortic MVP. The last TTE with and without gas emboli were considered for the same patient and the no emboli group was the control group (42 patients). The patient's blood pressure (BP) and heart rate (HR) were available for each TTE. Comparing the two TTEs, the systolic and diastolic BP, transmitral and aortic gradients, and left ventricular ejection fraction were similar but the HR (80.9 ± 18.7 vs 72.5 ± 13.9 bpm, P = .02) was significantly higher in the group with gas emboli. A TEE was performed 52 times in 27 patients, due to gas emboli, with one case positive for thrombus/vegetation. For 19 patients, a brain CT was requested. In two patients, the indication for the brain CT was gas emboli but the result was negative.ConclusionGas emboli are frequently present and associated to an increased HR. They can cause the misdiagnosis of endocarditis or thrombus formation with significant additional requests for diagnostic examinations.
Ecological assembly rules on arthropod community inhabiting mistletoes
Authors: Lázaro‐González Alba , Hódar José A. , Zamora Regino 
Published: May 2020

1. The colonisation of a new habitat by a community is led by deterministic and stochastic processes at different spatio‐temporal scales. Parasitic plants, such as mistletoe, represent a new habitat within forest canopy that is free to be colonised by many organisms.2. This study investigates how ecological factors operating at forest and plant scales drive changes in both specialist (mistletoe‐dwelling) and tourist (transient visitors) arthropod communities inhabiting European mistletoe, Viscum album subsp. austriacum, in a Mediterranean pine forest. The influence of elevation along a broad elevational gradient was tested by sampling arthropod communities dwelling in mistletoe plants and host pine branches and the effects of mistletoe plant size, distances to other mistletoes, and temporal variation in arthropod assemblages inhabiting mistletoes.3. The diversity of the specialist community remained constant along the elevational gradient and over the summer period, while the tourist and pine‐dwelling arthropod communities showed species turnover. Larger mistletoes were occupied by more species and individuals, whereas more isolated mistletoes presented the same equilibrium point as the more aggregated ones. Thus, mistletoe size is key to the composition of the arthropod community.4. In conclusion, this study's findings indicate contrasting assembly rules for specialised and tourist arthropod communities associated with mistletoe. The specialist community was highly stable and followed a deterministic trophic sequence of colonisation as the assemblage rule: first, colonisation by the main specialist herbivore, Cacopsylla visci, and, second, by its predator Anthocoris visci. Meanwhile, the tourist community, being a subset of the arthropod assemblage of the pine, acts independent of mistletoe presence.
Neurological manifestations and neuro‐invasive mechanisms of the severe acute respiratory syndrome coronavirus type 2
Authors: Vonck K. , Garrez I. , De Herdt V. , Hemelsoet D. , Laureys G. , Raedt R. , Boon P. 
Published: May 2020

Background and purposeInfections with coronaviruses are not always confined to the respiratory tract and various neurological manifestations have been reported. The aim of this study was to perform a review to describe neurological manifestations in patients with COVID‐19 and possible neuro‐invasive mechanisms of Sars‐CoV‐2.MethodsPubMed, Web of Science and COVID‐dedicated databases were searched for the combination of COVID‐19 terminology and neurology terminology up to 10 May 2020. Social media channels were followed up between 15 March and 10 May 2020 for postings with the same scope. Neurological manifestations were extracted from the identified papers and combined to provide a useful summary for the neurologist in clinical practice.ResultsNeurological manifestations potentially related to COVID‐19 have been reported in large studies, case series and case reports and include acute cerebrovascular diseases, impaired consciousness, cranial nerve manifestations and autoimmune disorders such as the Guillain–Barré syndrome often present in patients with more severe COVID‐19. Cranial nerve symptoms such as olfactory and gustatory dysfunctions are highly prevalent in patients with mild to moderate COVID‐19 even without associated nasal symptoms and often present in an early stage of the disease.ConclusionPhysicians should be aware of the neurological manifestations in patients with COVID‐19, especially when rapid clinical deterioration occurs. The neurological symptoms in COVID‐19 patients may be due to direct viral neurological injury or indirect neuroinflammatory and autoimmune mechanisms. No antiviral treatments against the virus or vaccines for its prevention are available and the long‐term consequences of the infection on human health remain uncertain especially with regard to the neurological system.
Stereotactic Laser Ablation for Mesial Temporal Lobe Epilepsy: A prospective, multicenter, single‐arm study
Authors: Sperling Michael R. , Gross Robert E. , Alvarez Guy E. , McKhann Guy M. , Salanova Vicenta , Gilmore Julie 
Published: May 2020

AbstractObjectiveTo describe the development of the Stereotactic Laser Ablation for Temporal Lobe Epilepsy study protocol in the context of current practice. An ideal treatment for drug‐resistant epilepsy remains an ongoing area of research. Although there are several options available, each has challenges that not only make deciding on the appropriate treatment not clear‐cut but also create difficulties in designing clinical studies to provide evidence in support of the treatment.MethodsA prospective, single‐arm, multicenter study designed to evaluate safety and efficacy of the VisualaseTM MRI‐Guided Laser Ablation System for the treatment of temporal lobe epilepsy will include up to 150 patients with a primary efficacy endpoint of seizure freedom (defined as Engel Class I) for the first 12 months following the procedure and a primary safety endpoint of incidence of qualifying device‐, procedure‐, or anesthesia‐related adverse events through 12 months following the procedure.ResultsPrimary endpoints will be assessed against historical values of safety and efficacy of anterior temporal lobectomy.SignificanceThe scientific and payor communities typically demand randomized controlled trials (RCTs) as definitive evidence for safety and efficacy claims. However, in circumstances where the medical device has already been cleared by regulatory authorities and is readily available in the market, an RCT may not be feasible to execute. It is therefore crucial to gain acceptance by both the scientific community and regulators to design a study that will satisfy all concerned.
Gene flow as a simple cause for an excess of high‐frequency‐derived alleles
Authors: Marchi Nina , Excoffier Laurent 
Published: May 2020

AbstractMost human populations exhibit an excess of high‐frequency variants, leading to a U‐shaped site‐frequency spectrum (uSFS). This pattern has been generally interpreted as a signature of ongoing episodes of positive selection, or as evidence for a mis‐assignment of ancestral/derived allelic states, but uSFS has also been observed in populations receiving gene flow from a ghost population, in structured populations, or after range expansions. In order to better explain the prevalence of high‐frequency variants in humans and other populations, we describe here which patterns of gene flow and population demography can lead to uSFS by using extensive coalescent simulations. We find that uSFS can often be observed in a population if gene flow brings a few ancestral alleles from a well‐differentiated population. Gene flow can either consist in single pulses of admixture or continuous immigration, but different demographic conditions are necessary to observe uSFS in these two scenarios. Indeed, an extremely low and recent gene flow is required in the case of single admixture events, while with continuous immigration, uSFS occurs only if gene flow started recently at a high rate or if it lasted for a long time at a low rate. Overall, we find that a neutral uSFS occurs under more restrictive conditions in populations having received single pulses of gene flow than in populations exposed to continuous gene flow. We also show that the uSFS observed in human populations from the 1000 Genomes Project can easily be explained by gene flow from surrounding populations without requiring past episodes of positive selection. These results imply that uSFS should be common in non‐isolated populations, such as most wild or domesticated plants and animals.
Biomarkers in melanoma and non‐melanoma skin cancer prevention and risk stratification
Authors: Trager Megan H. , Geskin Larisa J. , Samie Faramarz H. , Liu Liang 
Published: May 2020

AbstractThe rates of melanoma and non‐melanoma skin cancer (NMSC) have been increasing over the last twenty years in the United States, and this has been attributed to increased ultraviolet radiation exposure (UVR). Given these rising rates, preventative measures have become increasingly important to reduce the incidence and promote early detection of these cancers. Skin cancer prevention remains a challenging task to accomplish mainly due to the lack of reliable and sensitive methods to provide objective risk information that can educate and motivate individuals to avoid sunburn. Currently, minimal erythema dose (MED) is used as a marker of UVR. However, it is not an ideal marker because significant cancer‐related molecular damage can occur after UVR exposure that cannot be detected by MED. Thus, over the recent years there has been significant interest in development of biomarkers indicative of exposure to UVR to improve early detection of cutaneous malignancies. Here, we will discuss emerging biomarkers for melanoma and NMSC that can help with risk stratification and targeted prevention and treatment.
Novel potential of metformin on valproic acid‐induced autism spectrum disorder in rats: involvement of antioxidant defence system
Authors: Ishola Ismail O. , Balogun Aishat O. , Adeyemi Olufunmilayo O. 
Published: May 2020

AbstractPrenatal exposure to valproic acid (VPA) has been shown to increase the risk of autism in children. This study examined the effect of metformin on VPA‐induced autism spectrum disorders in rats. Pregnant albino rats administered VPA (500 mg/kg, i.p.) or normal saline (10 mL/kg, i.p.; vehicle‐control) on gestational day 12.5. The pups were given metformin (5, 50 or 500 mg/kg, p.o.) or vehicle (10 mL/kg, p.o.) daily from postnatal day (PND) 21–50. Social behaviour, spatial learning/reference memory, repetitive behaviour and anxiety were assessed using the three‐chamber social assay, Morris water maze (MWM), Y maze and elevated plus maze tests (EPM), respectively. On PND 51, the animals were euthanized and brains removed for biochemical assay. In utero VPA exposure caused significant reduction in sociability index, social novelty preference index in three‐chambered apparatus and spatial learning and reference memory deficits in the MWM task as well as increase in repetitive/anxiety‐like behaviour in Y maze and EPM tests, respectively, which were ameliorated by post‐treatment with metformin in a dose‐dependent manner. Moreover, prenatal VPA increased malondialdehyde (MDA) and nitrite levels as well as deficits in antioxidant enzymes activities in the hippocampus and prefrontal cortex (PFC) which were attenuated by metformin administration. Similarly, VPA‐induced increase in acetylcholinesterase activity in the hippocampus and PFC were attenuated by postnatal treatment with metformin. Findings from this study showed that postnatal administration of metformin prevented valproic acid‐induced autistic‐like behaviour. Hence, metformin could be a potential adjunct in the management of autism spectrum disorders.
Structural insight into tanapoxvirus‐mediated inhibition of apoptosis
Authors: Suraweera Chathura D. , Anasir Mohd Ishtiaq , Chugh Srishti , Javorsky Airah , Impey Rachael E. , Hasan Zadeh Mohammad , Soares da Costa Tatiana P. , Hinds Mark G. , Kvansakul Marc 
Published: May 2020

Premature programmed cell death or apoptosis of cells is a strategy utilized by multicellular organisms to counter microbial threats. Tanapoxvirus (TANV) is a large double‐stranded DNA virus belonging to the poxviridae that causes mild monkeypox‐like infections in humans and primates. TANV encodes for a putative apoptosis inhibitory protein 16L. We show that TANV16L is able to bind to a range of peptides spanning the BH3 motif of human proapoptotic Bcl‐2 proteins and is able to counter growth arrest of yeast induced by human Bak and Bax. We then determined the crystal structures of TANV16L bound to three identified interactors, Bax, Bim and Puma BH3. TANV16L adopts a globular Bcl‐2 fold comprising 7 α‐helices and utilizes the canonical Bcl‐2 binding groove to engage proapoptotic host cell Bcl‐2 proteins. Unexpectedly, TANV16L is able to adopt both a monomeric and a domain‐swapped dimeric topology where the α1 helix from one protomer is swapped into a neighbouring unit. Despite adopting two different oligomeric forms, the canonical ligand binding groove in TANV16L remains unchanged from monomer to domain‐swapped dimer. Our results provide a structural and mechanistic basis for tanapoxvirus‐mediated inhibition of host cell apoptosis and reveal the capacity of Bcl‐2 proteins to adopt differential oligomeric states whilst maintaining the canonical ligand binding groove in an unchanged state.DatabaseStructural data are available in the Protein Data Bank (PDB) under the accession numbers 6TPQ, 6TQQ and 6TRR.
Fatigue of vulcanized natural rubber under proportional and non‐proportional loading
Authors: Wang Yanping , Liu Jianjun , Duan Wuwei , Pan Zheng , Qiao Yu 
Published: May 2020

AbstractTwo natural rubber (NR) compounds of hardness shore A 60 and 70 with 10 different biaxial displacement/twist paths were investigated using an axisymmetric cylindrical hollow dumbbell specimen. The effects of the proportional and non‐proportional loading modes on the fatigue life are discussed. In total, 52 fatigue test results are reported with fatigue life results of 3,918 to 488,000 cycles. The effect of the channel phase on the fatigue life is discussed.
Further Evaluation of Penglai Zircon Megacrysts as a Reference Material for (U‐Th)/He Dating
Authors: Yu Shun , Sun Jingbo , Evans Noreen J. , Danišík Martin , Wu Lin , Tian Yuntao , Shen Ze 
Published: May 2020

The α‐ejection‐corrected (U‐Th)/He dates of the widely used reference materials (e.g., Fish Canyon Tuff zircon) can be inaccurate for several reasons (e.g., inclusions, U‐Th zonation). There is a need for large, widely available, compositionally homogeneous mineral reference materials with accurately and precisely known ages. In this work, four individual Penglai zircon megacrysts are evaluated via interlaboratory (U‐Th)/He dating comparison, trace element analysis, U‐Pb dating and a range of characterisation methods. The (U‐Th)/He ages and 206Pb/238U ages are variable between Penglai megacrysts – 4.12 ± 0.10 Ma (1s) and 4.29 ± 0.05 Ma (1s) (PL1), 3.07 ± 0.25 Ma (1s) and 3.95 ± 0.05 Ma (1s) (PL2), 3.04 ± 0.24 Ma (1s) and 3.06 ± 0.07 Ma (1s) (PL4), and 4.49 ± 0.07 Ma (1s) (PL5; (U‐Th)/He age only), respectively. A single, cm‐sized megacryst (PL1) qualifies as a new (U‐Th)/He dating reference material, as it is structurally and chemically homogeneous, and yielded a highly reproducible and statistically indistinguishable (U‐Th)/He age of 4.12 ± 0.10 Ma from repeated analysis in multiple laboratories (slightly younger than the 206Pb/238U age of 4.29 ± 0.05 Ma). These results confirm Penglai zircon as a suitable reference material for (U‐Th)/He dating, on the proviso that some care needs to be taken to characterise individual megacrysts for trace element zonation, and to verify (U‐Th)/He (and U‐Pb ages, if double dating) prior to routine use. The 206Pb/238U ages and (U‐Th)/He ages obtained in this work provide constraints on the timing of Penglai megacryst crystallisation and eruption, and confirm at least two eruptive episodes during the Neogene in the Leiqiong area.
Headaches During COVID‐19: My Clinical Case and Review of the Literature
Authors: Belvis Robert 
Published: May 2020

ObjectiveTo analyze headaches related to COVID‐19 based on personal case experience.BackgroundCOVID‐19 is an infection caused by the new coronavirus SARS‐CoV‐2. The first reported case happened in Wuhan on December 1, 2019. At present, at least 1.8 million people are infected around the world and almost 110,000 people have died. Many studies have analyzed the clinical picture of COVID‐19, but they are focused on respiratory symptoms and headache is generically treated.MethodsI describe and discuss my headaches during my COVID‐19 and I review the MEDLINE literature about headaches and COVID‐19.ResultsMore than 41,000 COVID‐19 patients have been included in clinical studies and headache was present in 8%‐12% of them. However, no headache characterization was made in these studies. As a headache expert and based on my own personal clinical case, headaches related to COVID‐19 can be classified in the 2 phases of the disease. Acute headache attributed to systemic viral infection, primary cough headache, tension‐type headache and headache attributed to heterophoria can appear in the first phase (the influenza‐like phase); and headache attributed to hypoxia and a new headache, difficult to fit into the ICHD3, can appear if the second phase (the cytokine storm phase) occurs.ConclusionsSeveral headaches can appear during COVID‐19 infection. All of them are headaches specified in the ICHD3, except 1 that occurs from the 7th day after the clinical onset. This headache is probably related to the cytokine storm that some patients suffer and it could be framed under the ICHD3 headache of Headache attributed to other non‐infectious inflammatory intracranial disease. Although the reported prevalence of headaches as a symptom of COVID‐19 infection is low, this experience shows that, very probably, it is underestimated.
Loss of switch/sucrose non‐fermenting complex protein expression in undifferentiated gastrointestinal and pancreatic carcinomas
Authors: Tessier‐Cloutier Basile , Schaeffer David F , Bacani Julinor , Marginean Celia E , Kalloger Steve , Köbel Martin , Lee Cheng‐Han 
Published: May 2020

AimsUndifferentiated carcinoma refers to an epithelial malignancy that lacks morphological evidence of differentiation. Recent studies have implicated the loss of constitutively expressed switch/sucrose non‐fermenting (SWI/SNF) complex subunits in undifferentiated carcinomas of the gastrointestinal tract and other sites. In this study we examine the expression of SWI/SNF and mismatch repair (MMR) proteins in a series of undifferentiated carcinomas from the gastrointestinal tract and the pancreas.Methods and resultsWe searched pathology databases from four Canadian health centres for primary undifferentiated carcinoma from gastrointestinal and pancreatic resection specimens. Upon review of 31 cases, 19 were confirmed to be undifferentiated carcinomas (eight colonic, six gastric, three pancreatic, one appendiceal and one duodenal). Immunohistochemical analysis of SMARCA4, SMARCA2, SMARCB1, ARID1A, ARID1B, MSH2, MSH6, MLH1 and PMS2 was performed on whole sections. Five of 19 (26%) showed loss of core SWI/SNF proteins (two loss of SMARCA4, one loss of SMARCB1 and two concurrent loss of ARID1A and ARID1B). SMARCA4, SMARCB1, or ARID1A/ARID1B‐deficient undifferentiated carcinoma consistently exhibited sheet‐like growth pattern, with cellular discohesion and rhabdoid morphology. Nine of 17 undifferentiated carcinomas tested were MMR‐deficient by immunohistochemistry. In comparison, none of the 12 poorly differentiated carcinomas that were originally diagnosed as undifferentiated carcinomas showed loss of SMARCA4, SMARCA2, SMARCB1 or ARID1B.ConclusionsUndifferentiated gastrointestinal/pancreatic carcinomas show frequent loss of expression of SWI/SNF complex proteins. The loss of these core components of SWI/SNF complex may contribute to the arrest of cellular differentiation, resulting in the undifferentiated histology and aggressive clinical behaviour.
Geochemical characteristics and Sr‐Nd‐Hf isotope compositions of Late Triassic post‐collisional A‐type granites in Sarudik, SW Sumatra, Indonesia
Authors: Zhang Haikun , Hu Peng , Cao Liang , Tampubolon Armin , Liu Asui , Cheng Xiang , Zhan Mingguo , Pan Luozhong , Dai Yu , Pan Beihong 
Published: May 2020

AbstractLate Triassic A‐type granites are identified in this study in Sarudik, SW Sumatra. We present new data on zircon U–Pb geochronology, whole‐rock major and trace elements and Sr‐Nd‐Hf isotope geochemistry, aiming to study their petrogenesis and tectonic implications. LA‐ICP‐MS U–Pb dating of zircon separated from one biotite monzogranite sample yields a concordia age of 222.6 ±1.0 Ma, indicating a Late Triassic magmatic event. The studied granites are classified as weakly peralumious, high‐K calc‐alkaline granites. They exhibit high SiO2, K2O + Na2O, FeO/(FeO + MgO) and Ga/Al ratios and low Al2O3, CaO, MgO, P2O5 and TiO2 contents, with enrichment of Rb, Th and U and depletion of Ba, Sr, P and Eu, showing the features of A‐type granites. The granites have zircon εHf(t) values from −4.6 to −0.4 and whole‐rock εNd(t) values from −5.51 to −4.98, with Mesoproterozoic TDM2 ages (1278–1544 Ma) for both Hf and Nd isotopes. Geochemical and isotopic data suggest that the source of these A‐type granites is the Mesoproterozoic continental crust, without significant incorporation of mantle‐derived component, and their formation is controlled by subsequent fractional crystallization. The Sarudik A‐type granites are further assigned to A2‐type formed in post‐collisional environment. Combined with previous knowledge on the western SE Asia tectonic evolution, we conclude that the formation of the Late Triassic A‐type granites is related to the post‐collisional extension induced by the crustal thickening, gravitational collapse, and asthenosphere upwelling following the collision between the Sibumasu and the East Malaya Block.