bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of clinical predictive values for radiographic pneumonia in children
Authors: Rees Chris A , Basnet Sudha , Gentile Angela , Gessner Bradford D , Kartasasmita Cissy B , Lucero Marilla , Martinez Luis , O'Grady Kerry-Ann F , Ruvinsky Raul O , Turner Claudia , Campbell Harry , Nair Harish , Falconer Jennifer , Williams Linda J , Horne Margaret , Strand Tor , Nisar Yasir B , Qazi Shamim A , Neuman Mark I
Published: August 2020

Introduction

Healthcare providers in resource-limited settings rely on the presence of tachypnoea and chest indrawing to establish a diagnosis of pneumonia in children. We aimed to determine the test characteristics of commonly assessed signs and symptoms for the radiographic diagnosis of pneumonia in children 0–59 months of age.

Methods

We conducted an analysis using patient-level pooled data from 41 shared datasets of paediatric pneumonia. We included hospital-based studies in which >80% of children had chest radiography performed. Primary endpoint pneumonia (presence of dense opacity occupying a portion or entire lobe of the lung or presence of pleural effusion on chest radiograph) was used as the reference criterion radiographic standard. We assessed the sensitivity, specificity, and likelihood ratios for clinical findings, and combinations of findings, for the diagnosis of primary endpoint pneumonia among children 0–59 months of age.

Results

Ten studies met inclusion criteria comprising 15 029 children; 24.9% (n=3743) had radiographic pneumonia. The presence of age-based tachypnoea demonstrated a sensitivity of 0.92 and a specificity of 0.22 while lower chest indrawing revealed a sensitivity of 0.74 and specificity of 0.15 for the diagnosis of radiographic pneumonia. The sensitivity and specificity for oxygen saturation <90% was 0.40 and 0.67, respectively, and was 0.17 and 0.88 for oxygen saturation <85%. Specificity was improved when individual clinical factors such as tachypnoea, fever and hypoxaemia were combined, however, the sensitivity was lower.

Conclusions

No single sign or symptom was strongly associated with radiographic primary end point pneumonia in children. Performance characteristics were improved by combining individual signs and symptoms.
Creating the Moorfields’ virtual eye casualty: video consultations to provide emergency teleophthalmology care during and beyond the COVID-19 pandemic
Authors: Kilduff Caroline LS , Thomas Alice AP , Dugdill Juliet , Casswell Edward J , Dabrowski Marcin , Lovegrove Claire , Sim Dawn A , Hay Gordon R , Thomas Peter BM
Published: August 2020

Background

The COVID-19 crisis forced hospitals in the UK dramatically to reduce outpatient activity. To provide continuity of care and to assist patients reluctant or unable to leave their homes, video consultations were rapidly implemented across routine and emergency ophthalmology services.

Objective

To describe the deployment and scaling to a large volume of teleophthalmology using a video consultation platform ‘Attend Anywhere’ in Moorfields Eye Hospital’s accident and emergency (A&E) department (London, UK).

Method

Patient satisfaction, waiting time, consultation duration, outcome and management were audited following the launch of the new virtual A&E service.

Results

In the 12 days following the service launch, 331 patients were seen by video consultation. 78.6% of patients (n=260) were determined not to need hospital A&E review and were managed with advice (n=126), remote prescription (n=57), general practitioner referral (n=27), direct referral to hospital subspecialty services (n=26) or diversion to a local eye unit (n=24). Mean patient satisfaction was 4.9 of 5.0 (n=62). The mean consultation duration was 12 min (range 5–31 min) and the wait time was 6 min (range 0–37 min).

Conclusion

Video consultations showed greater than expected usefulness in the remote management of eye disease and supported a substantial reduction in the number of people visiting the hospital.
Quality improvement project for improving inpatient glycaemic control in non-critically ill patients admitted on medical floor with type 2 diabetes mellitus
Authors: Khan Adeel Ahmad , Shahzad Aamir , Rose Samman , Al Mohanadi Dabia Hamad S H , Zahid Muhammad
Published: August 2020

A significant number of patients admitted to the medical floor have type 2 diabetes mellitus (DM). Lack of a standardised inpatient hyperglycaemia management protocol leads to improper glycaemic control adding to morbidity in such patients. American Diabetes Association, in its 2019 guidelines, recommends initiation of a regimen consisting of basal insulin (long-acting insulin) or basal plus correctional insulin for non-critically ill hospitalised patients with poor or no oral intake. A combination of basal insulin, bolus (short-acting premeal or prandial) insulin and correctional scale insulin is recommended for inpatient hyperglycaemia management in non-critical patients with type 2 DM who have proper oral intake. Baseline data of 100 patients with diabetes admitted to Hamad General Hospital Doha, Qatar, showed that although insulin was used in the majority of patients, there was lack of uniformity in the initiation of insulin regimen. Adequate glycaemic control (7.8–10 mmol/L) was achieved in 45% of patients. Using Plan–Do–Study–Act (PDSA) model of improvement, a quality improvement project was initiated with the introduction of a standardised inpatient hyperglycaemia management protocol aiming to achieve 50% compliance to protocol and improvement in inpatient glycaemic control from baseline of 45% to 70%. Interventions for change included development of a standardised inpatient hyperglycaemia management protocol and its provision to medical trainees, teaching sessions for trainees and nurses, active involvement of medical consultants for supervision of trainees to address the fear of hypoglycaemia, regular reminders/feedbacks to trainees and nurses about glycaemic control of their patients and education about goals of diabetes management during hospitalisation for patients with diabetes. Overall, glycaemic control improved significantly with target glycaemic control of 70% achieved in 4 of the 10 PDSA cycles without an increase in the number of hypoglycaemic episodes. We conclude that development of a standardised inpatient insulin prescribing protocol, educational sessions for medical trainees and nurses about goals of diabetes management during hospitalisation, regular reminders to healthcare professionals and patient education are some of the measures that can improve glycaemic control of patients with type 2 DM during inpatient stay.
Out-of-hospital deaths among children during COVID-19 pandemic: indicator of collateral damage?
Authors: Harve-Rytsälä Heini , Puhakka Laura , Kuisma Markku , Kuitunen Mikael , Oulasvirta Jelena , Salmi Heli
Published: August 2020

We aimed to investigate the out-of-hospital mortality, and the actual prevalence of COVID-19 in children requiring paediatric emergency department (ED) care for infectious symptoms. There were four emergency medical services (EMS) responses concerning children (age 0–15 years) leading to death on-scene in 2 months during the pandemic, and eight during the previous 12 months in the Helsinki University Hospital area, although the number of EMS missions decreased by 18%. The prevalence of COVID-19 in children contacting a paediatric ED for any infectious symptoms during the epidemic peak was only 2.7%.
Simulation capacity building in rural Indian hospitals: a 1-year follow-up
qualitative analysis
Authors: Sheshadri Veena , Wasserman Isaac , Peters Alexander W , Santhirapala Vatshalan , Mitra Shivani , Sandler Simone , Svensson Emma , Ljungman David , George Regi , Ambepu Arundhathi , Krishnan Jithendranath , Kataria Raman , Afshar Salim , Meara John G , Galea Jerome T , Weinstock Peter , Roussin Christopher , Taylor Matthew , Menon Nandakumar , McClain Craig D
Published: August 2020

Introduction

The benefits of simulation-based medical training are well described. The
most effective way to plant and scale simulation training in rural locations
remains undescribed. We sought to plant simulation training programmes for
anaesthesia emergencies in two rural Indian hospitals.

Methods

Two Indian consultant anaesthetists without experience in medical
simulation underwent a 3-day course at the Boston Children’s Hospital’s (BCH)
Simulator Program. They returned to their institutions and launched simulation
programmes with an airway manikin and mock patient monitor. The 1-year
experience was evaluated using individual, in-depth interviews of simulation
facilitators. Three staff members (responsible for facilitating medical
simulations over the prior year) at two rural hospitals in India were
interviewed. None attended the BCH training; instead, they received on-the-job
training from the BCH-trained, consultant anaesthetist colleagues.

Results

Successes included organisational adoption of simulation training with
exercises 1 year after the initial BCH-training, increased interdisciplinary
teamwork and improved clinical competency in managing emergencies. Barriers to
effective, local implementation of simulation programmes fell into three
categories: time required to run simulations, fixed and rigid roles, and
variable resources. Thematic improvement requests were for standardised
resources to help train simulation facilitators and demonstrate to participants
a well-run simulation, in addition to context-sensitive scenarios.

Conclusion

An in-person training of simulation facilitators to promote medical
simulation programmes in rural hospitals produced ongoing simulation programmes
1 year later. In order to make these programmes sustainable, however, increased
investment in developing simulation facilitators is required. In particular,
simulation facilitators must be prepared to formally train other simulation
facilitators, too.
Tumor copy-number alterations predict response to immune-checkpoint-blockade in gastrointestinal cancer
Authors: Lu Zhihao , Chen Huan , Li Shuang , Gong Jifang , Li Jian , Zou Jianling , Wu Lihong , Yu Jianing , Han Wenbo , Sun Huaibo , Jiao Xi , Zhang Xiaotian , Peng Zhi , Lu Ming , Wang Zhenghang , Zhang Henghui , Shen Lin
Published: August 2020

Background

Despite the great achievements made in immune-checkpoint-blockade (ICB) in cancer therapy, there are no effective predictive biomarkers in gastrointestinal (GI) cancer.

Methods

This study included 93 metastatic GI patients treated with ICBs. The first cohort comprising 73 GI cancer patients were randomly assigned into discovery (n=44) and validation (n=29) cohorts. Comprehensive genomic profiling was performed on all samples to determine tumor mutational burden (TMB) and copy-number alterations (CNAs). A subset of samples was collected for RNA immune oncology (IO) panel sequencing, microsatellite instability (MSI)/mismatch repair and program death ligand 1 (PD-L1) expression evaluation. In addition, 20 gastric cancer (GC) patients were recruited as the second validation cohort.

Results

In the first cohort of 73 GI cancer patients, a lower burden of CNA was observed in patients with durable clinical benefit (DCB). In both the discovery (n=44) and validation (n=29) subsets, lower burden of CNA was associated with an improved clinical benefit and better overall survival (OS). Efficacy also correlated with a higher TMB. Of note, a combinatorial biomarker of TMB and CNA may better stratify DCB patients from ICB treatment, which was further confirmed in the second validation cohort of 20 GC patients. Finally, patients with lower burden of CNA revealed increased immune signatures in our cohort and The Cancer Genome Atlas data sets as well.

Conclusions

Our results suggest that the burden of CNA may have superior predictive value compared with other signatures, including PD-L1, MSI and TMB. The joint biomarker of CNA burden and TMB may better stratify DCB patients, thereby providing a rational choice for GI patients treated with ICBs.
Safety and efficacy of CAR-T cell targeting BCMA in patients with multiple myeloma coinfected with chronic hepatitis B virus
Authors: Han Lu , Zhou Jian , Zhou Keshu , Zhu Xinghu , Zhao Lingdi , Fang Baijun , Yin Qingsong , Wei Xudong , Zhou Hu , Li Linlin , Xu Bengling , Zhang Jishuai , Song Yongping , Gao Quanli
Published: August 2020

Background

Reactivation of hepatitis B virus (HBV) infection is a well-recognized complication in patients with chronic or resolved HBV infection undergoing anticancer therapy. There is a risk of HBV reactivation after infusion of chimeric antigen receptor (CAR) T cells for patients with refractory/relapsed (R/R) multiple myeloma (MM).

Methods

We administered B cell maturation antigen (BCMA) CAR-T cell by infusion to nine patients with R/R MM with chronic or resolved HBV infection. Patient serum was analyzed to determine the expression of five components of HBV and the copy number of HBV DNA. HBV reactivation was defined if a patient re-exhibited hepatitis B surface antigen (HBsAg) or HBV DNA regrowth after CAR-T therapy.

Results

In one patient who was HBsAg-positive, no HBV reactivation was observed during the follow-up period of 9.8 months after administration of anti-HBV drugs before and after CAR-T therapy. Among eight patients with MM who had resolved HBV infection, two patients administered prophylactic anti-HBV drugs did not exhibit HBV reactivation. Of the six patients who did not use prophylactic antiviral drugs, five did not exhibit HBV reactivation, while one showed recurrence of HBsAg without detection of HBV DNA or damage to liver function. The best objective response rate was 100%, and the progression-free survival (PFS) at 12 months was of 88.89% (median PFS was not observed).

Conclusions

These findings showed that BCMA CAR-T cell therapy could be used in patients with R/R MM with chronic or resolved HBV infection and that antiviral drugs should be administered in these patients during CAR-T cell therapy.
Revisiting the scalar weak gravity conjecture
Authors: Benakli Karim , Branchina Carlo , Lafforgue-Marmet Gaëtan
Published: August 2020

We revisit the scalar weak gravity conjecture and investigate the possibility to impose that scalar interactions dominate over gravitational ones. More precisely, we look for consequences of assuming that, for leading scalar interactions, the corresponding gravitational contribution is sub-dominant in the non-relativistic limit. For a single massive scalar particle, this leads us to compare four-point self-interactions in different type of potentials. For axion-like particles, we retrieve the result of the axion weak gravity conjecture: the decay constant f is bounded by the Planck mass, $$f < {M_{Pl}}$$f<MPl. Similar bounds are obtained for exponential potentials. For quartic, power law and Starobinsky potentials, we exclude large trans-Planckian field excursions. We then discuss the case of moduli that determine the scalars masses. We retrieve the exponential dependence as requested by the Swampland distance conjecture. We also find extremal state masses with field dependence that reproduces both the Kaluza-Klein and winding modes behaviour. In particular cases, our constraints can be put in the form of the Refined de Sitter Conjecture.
Polynomial energy bounds for type F4 WZW-models
Authors: Gui Bin
Published: August 2020

We prove that for any type [Formula: see text] unitary affine VOA [Formula: see text], sufficiently many intertwining operators satisfy polynomial energy bounds. This finishes the Wassermann type analysis of intertwining operators for all WZW-models.
Quantum-inspired binary gravitational search algorithm to recognize the facial expressions
Authors: Kumar Yogesh , Verma Shashi Kant , Sharma Sandeep
Published: August 2020

This paper addresses an autonomous facial expression recognition system using the feature selection approach of the Quantum-Inspired Binary Gravitational Search Algorithm (QIBGSA). The detection of facial features completely depends upon the selection of precise features. The concept of QIBGSA is a modified binary version of the gravitational search algorithm by mimicking the properties of quantum mechanics. The QIBGSA approach reduces the computation cost for the initial extracted feature set using the hybrid approach of Local binary patterns with Gabor filter method. The proposed automated system is a sequential system with experimentation on the image-based dataset of Karolinska Directed Emotional Faces (KDEF) containing human faces with seven different emotions and different yaw angles. The experiments are performed to find out the optimal emotions using the feature selection approach of QIBGSA and classification using a deep convolutional neural network for robust and efficient facial expression recognition. Also, the effect of variations in the yaw angle (front to half side view) on facial expression recognition is studied. The results of the proposed system for the KDEF dataset are determined in three different cases of frontal view, half side view, and combined frontal and half side view images. The system efficacy is analyzed in terms of recognition rate.
Investigation on flapping dynamics and wake characteristics of a flexible plate in nonlinear hysteresis region
Authors: Shen Pingping , Dou Huashu , Wei Yikun , Tu Chengxu , Xu Hui
Published: August 2020

In this paper, the flapping dynamics and wake flow characteristics in the nonlinear hysteresis region are investigated experimentally by immersing a cantilevered flexible plate in uniform airflow. The experimental results show that the flapping mode of a cantilevered flexible plate in hysteresis region will be transited from periodical traveling wave mode to limited cantilever-like mode with the variation of Reynolds number. The flapping mode will greatly influence the kinetic parameters of a flexible plate and also wake flow characteristics. The comparison of Strouhal number values between flapping flexible plate and animals further indicates that the fluid dynamics between passive flapping and active swimming is similar to the obtained optimal propulsive efficiency. Flow visualization reveals that the Karman vortex street appears, vanishes and coherent structures of turbulent flow arise behind the stable flexible plate with increasing Reynolds number. Meanwhile, the measurements of pressure distribution in wake flow provide a good physical understanding of the energy-saving mechanism and the optimal arrangement in fish school. Moreover, the fast Fourier transform (FFT) spectra of fluctuating velocity indicate that the characteristics of wake flow are closely related to the flapping mode of flexible plate. The wake flow will come into strong harmonic excitation state when flapping mode transits into a limited cantilever-like mode.
You can see a clock running backwards in time
Authors: Paranjape M. B.
Published: August 2020

The epitome of a causal or anti-chronological behavior would be to see a clock running backwards in time. In this essay, we point out that this is indeed possible, but there is no problem with causality. What you see is not what is really happening. Locally, causality is always respected. However, our observation should be cause for pause to astronomers and cosmologists, who strictly observe events occurring at very large distances or very long ago and certainly not locally. It can be that what you see is not what you necessarily get.
Self-gravitating dark matter gets in shape
Authors: Wagner Jenny
Published: August 2020

In our current best cosmological model, the vast majority of matter in the universe is dark, consisting of yet undetected, nonbaryonic particles that do not interact electro-magnetically. So far, the only significant evidence for dark matter has been found in its gravitational interaction, as observed in galaxy rotation curves or gravitational lensing effects. The inferred dark matter agglomerations follow almost universal mass density profiles that can be reproduced well in simulations, but have eluded an explanation from a theoretical viewpoint. Forgoing standard (astro-)physical methods, I show that it is possible to derive these profiles from an intriguingly simple mathematical approach that directly determines the most likely spatial configuration of a self-gravitating ensemble of collisionless dark matter particles.
Geometry creates inertia
Authors: Lahiri Amitabha
Published: August 2020

The dynamics of fermions in curved spacetime is governed by a spin connection, a part of which is contorsion, an auxiliary field independent of the metric, without dynamics but fully expressible in terms of the axial current density of fermions. Its effect is the appearance of a quartic interaction involving all fermions. Contorsion can couple to left- and right-handed fermions with different strengths, leading to an effective mass for fermions propagating on a background containing fermionic matter.
A new empirical formula for cross-sections of (n,nα) reactions
Authors: Yiğit Mustafa
Published: August 2020

Studies on the cross-sections of (n,n[Formula: see text]) reactions which are energetically possible, about 14 MeV neutrons are quite scarce. In this paper, the cross-sections of (n,n[Formula: see text] nuclear reactions at [Formula: see text]14–15 MeV are analyzed by using a new empirical formula based on the statistical theory. We show that neutron cross-sections are closely related to the [Formula: see text]-value of nuclear reaction, in particular for (n,n[Formula: see text]) channels. Results obtained with this empirical formula show good agreement with the available measured cross-section values. We hope that the estimations on the cross-sections using the present formalism may be helpful in future studies in this field.
The multiplicity characteristics of7Li-Em interactions as a function of noninteracting projectile nucleons
Authors: Mohery M. , Sultan E. M. , Abdallah N. N. , Farghaly M. H.
Published: August 2020

In this work, the interactions of7Li nuclei with emulsion at 3 A GeV/c were studied. Multiplicity of the charged secondary particles as well as the charge of the outgoing projectile fragments were measured, while correlations among them are discussed. The values of the total charge of the noninteracting projectile nucleons and the average number of interacting projectile nucleons are estimated. The dependence of the secondary particles on the number of heavily-ionized tracks is analyzed. The results show that interactions of7Li nuclei with emulsion nuclei exhibit a number of regularities, which had been noted in experiments with lighter nuclei. The absorption of relativistic particles, while increasing the degree of target destruction, is observed. The average multiplicities of the secondary charged particles depend on the impact parameter, as their values increase, while decreasing the impact parameter. The number of secondary charged particles in the heavy-ion interactions depends on the degree of disintegration of the target nuclei. This dependence is not observed in the case of the interaction of hadron with emulsion. The experimental data of the interaction of7Li are systematically compared with the other interactions at different energies. The results agree with the corresponding results at nearly the same energy.
SIX WEEKS OF TREADMILL RUNNING EXERCISE IMPROVE BONE ARCHITECTURE IN ADULT OSTEOPENIC RATS: AN EXPERIMENTAL STUDY TOWARD EXERCISE DOSE PRESCRIPTION
Authors: Ahmed Mona Mohammed Ibrahim , El Nahass Bassem , Ibrahiem Hanna Abdelkadir
Published: August 2020

Question: Can exercise dose be established for bone weakness treatment? Design: Randomized experimental study. Participants: Thirty two adult (12 weeks) Wistar rats (16 males and 16 females) weighed [Formula: see text][Formula: see text]gm. Intervention: Rats were tail suspended for 2 weeks and then randomly divided into four groups; Group I ([Formula: see text]) sacrificed after suspension, Group II ([Formula: see text]) normal cage activities. Group III: ([Formula: see text]) level surface treadmill running. Group IV: ([Formula: see text]) uphill treadmill at angle of 15∘. The running speed was 12[Formula: see text]m/min for a period of 30[Formula: see text]min daily at frequency of 5 days/week for 6 weeks. Outcome measures: Histomorphometric analysis of distal femurs of right hind limbs to measure bone architectural parameters (cortical thickness, Tb.Th, Tb.Nm, Tb.Sp, Tb.Ar, Bone marrow area and density and TBA). Results: Significant improvements were shown in bone architecture in distal femur of Group IV ([Formula: see text]) compared to both Group I and Group II. No significant improvement in distal femur in Group III ([Formula: see text]) compared to both Group I and Group II. The percentage of change was found to be 62–96% between Group IV and Group II and 72– 82% between Group IV and Group I. Conclusion: The results suggested that uphill treadmill running exercises were effective to induce changes in bone tissue in the form of changing trabecular dimensions and density. The induced structural improvement was site specific and dose dependent.
The fast clustering algorithm for the big data based on K-means
Authors: Xie Ting , Zhang Taiping
Published: August 2020

As a powerful unsupervised learning technique, clustering is the fundamental task of big data analysis. However, many traditional clustering algorithms for big data that is a collection of high dimension, sparse and noise data do not perform well both in terms of computational efficiency and clustering accuracy. To alleviate these problems, this paper presents Feature K-means clustering model on the feature space of big data and introduces its fast algorithm based on Alternating Direction Multiplier Method (ADMM). We show the equivalence of the Feature K-means model in the original space and the feature space and prove the convergence of its iterative algorithm. Computationally, we compare the Feature K-means with Spherical K-means and Kernel K-means on several benchmark data sets, including artificial data and four face databases. Experiments show that the proposed approach is comparable to the state-of-the-art algorithm in big data clustering.
Single-cell RNA-seq data clustering: A survey with performance comparison study
Authors: Li Ruiyi , Guan Jihong , Zhou Shuigeng
Published: August 2020

Clustering analysis has been widely applied to single-cell RNA-sequencing (scRNA-seq) data to discover cell types and cell states. Algorithms developed in recent years have greatly helped the understanding of cellular heterogeneity and the underlying mechanisms of biological processes. However, these algorithms often use different techniques, were evaluated on different datasets and compared with some of their counterparts usually using different performance metrics. Consequently, there lacks an accurate and complete picture of their merits and demerits, which makes it difficult for users to select proper algorithms for analyzing their data. To fill this gap, we first do a review on the major existing scRNA-seq data clustering methods, and then conduct a comprehensive performance comparison among them from multiple perspectives. We consider 13 state of the art scRNA-seq data clustering algorithms, and collect 12 publicly available real scRNA-seq datasets from the existing works to evaluate and compare these algorithms. Our comparative study shows that the existing methods are very diverse in performance. Even the top-performance algorithms do not perform well on all datasets, especially those with complex structures. This suggests that further research is required to explore more stable, accurate, and efficient clustering algorithms for scRNA-seq data.
Effect of noise on deterministic remote preparation of an arbitrary two-qudit state by using a four-qudit χ-type state as the quantum channel
Authors: Lv Li , Zhou Ping
Published: August 2020

We present a protocol for remote preparation of an arbitrary two-qudit state by using a four-qudit [Formula: see text]-type state as the quantum channel via positive operator-valued measurement. We first propose the protocol for remote preparation of an arbitrary two-qudit state via positive operator-valued measurement in noiseless environment and then discuss the protocol in noisy environments. Four important quantum decoherence noise models, the dephasing noise, the qudit-flip noise, the qudit-phase-flip noise and the depolarizing noise, are considered in our protocol. The output states and the fidelities of remote state preparation in four different types of quantum noises are presented. It is shown the protocol for remote state preparation via positive operator-valued measurement with [Formula: see text]-type state has the advantage of transmitting less particles for remote preparing an arbitrary two-qudit state. The fidelities of remote state preparation depend on the coefficients of original two-qudit state and the decoherence rates of the noise models.
Large data scattering for NLKG on waveguide ℝd × 𝕋
Authors: Forcella Luigi , Hari Lysianne
Published: August 2020

We consider the pure-power defocusing nonlinear Klein–Gordon equation, in the [Formula: see text]-subcritical case, posed on the product space [Formula: see text], where [Formula: see text] is the one-dimensional flat torus. In this framework, we prove that scattering holds for any initial data belonging to the energy space [Formula: see text] for [Formula: see text]. The strategy consists in proving a suitable profile decomposition theorem on the whole manifold to pursue a concentration-compactness and rigidity method along with the proofs of (global in time) Strichartz estimates.
SME ACCESS TO FINANCE AND THE GLOBAL FINANCIAL CRISIS
Authors: UDELL GREGORY F.
Published: August 2020

This paper offers an overview of research on SME access to finance during the Global Financial Crisis (GFC) in order to cull key things that we have learned. It discusses selected articles that peg the frontier of knowledge on this topic in both European and American contexts. It highlights differences between these two areas in terms of how the crisis unfolded. It also identifies key differences in the availability of data between Europe and the US that shape the nature of the empirical analysis of the attendant credit crunch. Selected research on both the nature and magnitude of the impact of the credit crunch on the SME sector are discussed. Research on some key policy initiatives to mitigate the crisis’ damage in Europe and in the US are also discussed. The paper concludes with some comments on how research on the GFC might inform research on SME access to finance during the unfolding COVID-19 crisis.
Design and Implementation of a Novel Hybrid Rental Apartment Recommender System
Authors: Neloy Asif Ahmed , Alam Sazid , Bindu Rafia Alif
Published: August 2020

Recommender Systems (RSs) have become an essential part of most e-commerce sites nowadays. Though there are several studies conducted on RSs, a hybrid recommender system for the real state search engine to find appropriate rental apartment taking users preferences into account is still due. To address this problem, a hybrid recommender system is proposed in this paper constructed by two of the most popular recommendation approaches — Collaborative Filtering (CF), Content-Based Recommender (CBR). CF-based methods use the ratings given to items by users as the sole source of information for learning to make a recommendation. However, these ratings are often very sparse in applications like a search engine, causing CF-based methods to degrade accuracy and performance. To reduce this sparsity problem in the CF method, the Cosine Similarity Score (CSS) between the user and predicted apartment, based on their Feature Vectors (FV) from the CBR module is utilized. Improved and optimized Singular Value Decomposition (SVD) with Bias-Matrix Factorization (MF) of the CF model and CSS with FV of CBR constructs this hybrid recommender. The proposed recommender was evaluated using the Statistical Cross-Validation consisting of Leave-One-Out Validation (LOOCV). Experimental results show that it significantly outperformed a benchmark random recommender in terms of precision and recall. In addition, a graphical analysis of the relationships between the accuracy and error minimization is presented to provide further evidence for the potentiality of this hybrid recommender system in this area.
Comparison of predicted and actual states in tunnels: lessons to be learned from the Gerede Water Transmission Tunnel, Turkey
Authors: Apaydin Ahmet
Published: August 2020

The Gerede Tunnel is a large inter-basin project in Turkey. As with many long tunnels, some of the predictions in the project report and the tender contract have not been realized. Completion of the tunnel has been delayed for more than twice the time given in the tender contract. Unexpectedly complex geological–tectonic–hydrogeological conditions and the selection of tunnel-boring machines (TBMs) are the main reasons for this long delay. There were some discrepancies between the predicted and actual geology. The groundwater pressure encountered was much higher than expected. Plastic clays in the limestone and breccia and loose agglomerates with a high water pressure in the faults decreased the advance rate and led to several long stoppages. One of the three double-shield TBMs became stuck in the tunnel and could not be recovered. The last quarter of the tunnel was excavated more slowly, but without severe problems, by a modified earth pressure balance shield TBM. As a result, the TBM type, drive direction, length, route, cost and completion date of the Gerede Tunnel have all changed.
Tensors in Statistics
Authors: Bi Xuan , Tang Xiwei , Yuan Yubai , Zhang Yanqing , Qu Annie
Published: August 2020

This article provides an overview of tensors, their properties, and their applications in statistics. Tensors, also known as multidimensional arrays, are generalizations of matrices to higher orders and are useful data representation architectures. We first review basic tensor concepts and decompositions, and then we elaborate traditional and recent applications of tensors in the fields of recommender systems and imaging analysis. We also illustrate tensors for network data and explore the relations among interacting units in a complex network system. Some canonical tensor computational algorithms and available software libraries are provided for various tensor decompositions. Future research directions, including tensors in deep learning, are also discussed.
Investigation of Reducing Concentration Overvoltage toward Development of Low Pt-Loading PEFC
Authors: Takei S. , Uda K. , Nagayama M. , Sasaki K. , Hayashi A.
Published: August 2020

Membrane electrode assemblies (MEAs) with various catalyst-loading were made using a standard 46.5%Pt/KB (TEC10E50E) with the aim of developing low Pt-loading PEFCs. Since increase in concentration overvoltage for low catalyst-loading MEAs was observed, the mechanism of such increase in concentration overvoltage was considered, and then reducing concentration overvoltage was tried through two methods, by adding extra carbon and using a more hydrophobic carbon support, graphitized Ketjen black, within the cathode layer (CL). As a result, we have experimentally proven that increase in hydrophobicity of CL can promote water drain and reduce the concentration overvoltage for low catalyst-loading MEAs, and hydrophobicity is an important factor to be controlled within CL in addition to porosity.
Heat of Mixing During Fast Charge/Discharge of a Li-Ion Cell: A Study on NMC523 Cathode
Authors: Chalise Divya , Lu Wenquan , Srinivasan Venkat , Prasher Ravi
Published: August 2020

Predicting temperature rise accurately during fast charge/discharge of a Li-ion cell is essential to avoid thermal runaway and extend battery life. While modeling the temperature rise, it is necessary to model the heat generation correctly. Heat of mixing, one of the four main sources of heat generation in a Li-ion battery, has often been considered insignificant and therefore excluded from modeling. When included, it is modeled using the expression from a Taylor expansion approximation. In this work, we have shown the conditions when including the heat of mixing becomes important and quantified the error associated with using the Taylor expansion, especially under high charge/discharge conditions. Consequently, we carry out the calculation of the rate of enthalpy change and the heat generation rate from the most fundamental equation for the rate of the total enthalpy change without simplifying assumptions or approximations. The heat generation rate calculated doing so naturally includes irreversible, reversible and mixing heat. We then exclusively separate out the heat of mixing by subtracting the rate of enthalpy change by reaction from the rate of the total enthalpy change. Results show that the contribution of heat of mixing in the total heat generated increases with the charge/discharge rate and is as large as 23% for a 6 C discharge. This result suggests that while modeling heat generation for fast charge/discharge, it is necessary to include the heat of mixing and avoid calculating it using the Taylor expansion approximation.
Inhibition of Mg Corrosion by Sulfur Blocking of the Hydrogen Evolution Reaction on Iron Impurities
Authors: Mercier Dimitri , Światowska Jolanta , Protopopoff Elie , Zanna Sandrine , Seyeux Antoine , Marcus Philippe
Published: August 2020

A combination of electrochemical measurements, H2 volume measurements and surface analysis using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray Photoelectron Spectroscopy (XPS) was used to investigate the role of the metallic Fe impurities (60 ppm) in high purity (99.9 wt%) magnesium and the effect of sulfur on the hydrogen evolution. The Mg corrosion was studied in NaCl solutions containing dissolved hydrogen sulfide. At OCP and under anodic polarization the hydrogen evolution reaction and the growth of dark corroded areas were significantly inhibited in the presence of H2Saq. ToF-SIMS and XPS analyses showed the presence of sulfur adsorbed on Mg and on Fe segregated at grain boundaries. The observed inhibition of hydrogen evolution at OCP and above is assigned to a poisoning effect by adsorbed S of the H adsorption sites on segregated iron which, in the absence of sulfur, provides catalytic sites for excess HER. The equilibrium Pourbaix diagram for the Mg–Fe–S system including the adsorbed species predicts that S is adsorbed on Mg and Fe in the E-pH conditions of this work, which confirms the role assigned to adsorbed sulfur in the inhibition of excess hydrogen evolution at OCP and under anodic polarization in the presence of H2Saq.
Revisiting the role of concept mapping in teaching and learning pathophysiology for medical students
Authors: Fonseca Marta , Oliveira Beatriz , Carreiro-Martins Pedro , Neuparth Nuno , Rendas António
Published: August 2020

Concept mapping methodology is a way of representing knowledge described as a useful tool in medical education. It was introduced in the pathophysiology curricular unit at NOVA Medical School in 2002, within an ongoing experience of problem-based learning. Our goal is to present a comparison between the students’ opinions and performances in two academic years, 2017–18 and 2018–19, to evaluate the effects of pedagogical changes in the concept mapping methodology, applied in the last year, which is also described in detail. Our convenience samples were composed by 224 students in 2017–2018 and by 216 students in 2018–2019. The analysis used the students’ responses to the yearly institutional questionnaire on the quality of teaching and to a specific questionnaire applied to evaluate the tutorial sessions of 2018–19. Both were anonymous, and the response rate was above 50%. A comparison was also made between the continuous assessment during the tutorial sessions, expressed as a final cumulative score, and the results of an obligatory multiple-choice final test. The students considered the introduced pedagogical changes useful in their different components, such as identification of core concepts, construction of mini-maps, and their inclusion in final global maps. The better performance of the tutors, signaled by the students in 2018–19, was probably due to the preparatory pedagogical sessions.
Structured oral examination as an effective assessment tool in lab-based physiology learning sessions
Authors: Wang Lifeng , Khalaf Ahmad Taha , Lei Dongyu , Gale Mengke , Li Jing , Jiang Ping , Du Jing , Yinayeti Xuehereti , Abudureheman Mayinuer , Wei Yuanyuan
Published: August 2020

Traditional oral examination (TOE) is criticized for the shortage of objectivity, standardization, and reliability. These perceived limitations can be mitigated by the introduction of structured oral examination (SOE). There is little evidence of the implementation of SOE in physiology laboratory courses. The purpose of this study was to investigate the effect of SOE in laboratory-based learning sessions. Second-year medical students ( n = 114) attended a 16-wk physiology laboratory course. They were initially assessed by TOE in the middle of the academic term. The students’ perspectives on this assessment were measured by a modified three-point Likert-type scale questionnaire. Following this, faculty members prepared topics for SOE; nine topics were included from each laboratory course. The correct answers and scoring criteria were discussed among the faculty before the SOE event. One week after the last laboratory course, SOE was carried out for each student. As with the TOE process, student feedback was collected via a modified three-point Likert-type scale questionnaire. The mean laboratory homework score from the first four and last four laboratory courses was also calculated. Paper exams were also conducted after TOE and SOE. The results show that SOE is more acceptable to students than TOE. Significant differences ( P < 0.05) were observed in terms of uniformity of questions asked, syllabus coverage, and anxiety levels. In addition, SOE improved students’ performance in the laboratory course explored here. We contend that SOE shows promise as an effective assessment tool in laboratory-based physiology learning sessions.
Blood pressure control is not enough to normalize endothelial repair by progenitor cells
Authors: de Cavanagh Elena M. V. , González Sergio A. , Inserra Felipe , Forcada Pedro , Castellaro Carlos , Chiabaut-Svane Jorge , Obregón Sebastián , Casarini María Jesús , Kempny Pablo , Kotliar Carol
Published: August 2020

As individuals who present with risk factors within acceptable or average value ranges often develop cardiovascular (CV) disease, it has been suggested that other CV risk factors need to be considered in addition to those that are commonly combined in the Framingham score (FS) to estimate the risk of general CV disease. We investigated whether peripheral endothelial progenitor cells (EPCs) and tunneling nanotubes (TNTs) deserve to be considered. Here we report that EPCs and TNTs are significantly lower in controlled hypertensive patients versus normotensive subjects and that the disparity in vascular status between patients presenting with an FS of ≥10% with scarce vascular changes and those presenting with an FS of <10% with severe vascular impairment is related to differences in EPC and TNT numbers. These data point to EPC and TNT numbers as potential CV risk factors to be included in the FS calculation.
Investigation of Cytotoxicity Apoptotic and Inflammatory Responses of Biosynthesized Zinc Oxide Nanoparticles from Ocimum sanctum Linn in Human Skin Keratinocyte (Hacat) and Human Lung Epithelial (A549) Cells
Authors: Almutairi Bader , Albahser Gadah , Almeer Rafa , Alyami Nouf M. , Almukhlafi Hanouf , Yaseen Khadijah N. , Alkahtani Saad , Alarifi Saud
Published: August 2020

Pristine and engineered metal nanoparticles are widely applied in various fields of industry, and as consequences, they are useful as well as harmful to human health and environment. This study aimed at synthesizing the green zinc oxide nanoparticles (ZnNPs) using the leaf extract of Ocimum sanctum Linn and assessing its toxicity on human skin epidermal (HaCaT) and human lung epithelial (A549) cells. The synthesized green ZnNPs (gZnNPs) were characterized by using dynamic light scattering (DLS) and a high-resolution transmission electron microscope. The average size of gZnNPs obtained was 62 nm with a spherical shape. The effects of gZnNPs on the viability of HaCaT and A549 cells were investigated using tetrazolium salt (MTT) for 24 h. We have seen more reduction of cell viability of A549 cells in comparison to HaCaT cells. The induction of intracellular reactive oxygen species (ROS) was measured using DCFDA assay and showed a slightly high intensity of green fluorescence in A549 than HaCaT cells. The different oxidative stress biomarkers such as ROS generation and lipid peroxide were increased, and GSH was decreased in a dose-dependent manner. The apoptotic and necrotic effect of gZnNPs in both cells was carried out using Annexin-V-FITC and propidium iodide staining. More apoptotic and necrotic cells were found at a higher concentration of gZnNPs exposure. Also, we determined the effect of gZnNPs at the molecular level by evaluating the apoptotic and inflammatory markers, in which gZnNPs downregulated Bcl2 and upregulated Bax, caspase-3, and TNF-α in HaCaT and A549 cells. Ultimately, gZnNPs exerted toxicity and apoptosis in HaCaT and A549 cells.
Exosome: A Novel Nanocarrier Delivering Noncoding RNA for Bone Tissue Engineering
Authors: Liu Keda , Cao Nanjue , Zhu Yuhe , Wang Wei
Published: August 2020

Bone growth and metabolism are mainly regulated by a series of intracellular molecules and extracellular stimuli. Exosome, as a nanoscale substance secreted to the outside of the cells, plays an extensive role in intercellular communication. This review provides theoretical references and evidences for further exploration of exosomes as noncoding RNA carriers to regulate bone tissue recovery through the following aspects: (1) basic characteristics of exosomes, (2) research progress of exosomal noncoding RNA in bone tissue engineering, (3) current status and advantages of engineering exosomes as nanocarriers for noncoding RNA delivery, and (4) problems and application prospects of exosome therapy in the field of orthopedics.
Transmission Dynamics of Fractional Order Brucellosis Model Using Caputo–Fabrizio Operator
Authors: Peter Olumuyiwa James
Published: August 2020

In this paper, a noninteger order Brucellosis model is developed by employing the Caputo–Fabrizio noninteger order operator. The approach of noninteger order calculus is quite new for such a biological phenomenon. We establish the existence, uniqueness, and stability conditions for the model via the fixed-point theory. The initial approachable approximate solutions are derived for the proposed model by applying the iterative Laplace transform technique. Finally, numerical simulations are conducted for the analytical results to visualize the effect of various parameters that govern the dynamics of infection, and the results are presented using plots.