bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration Localization in Rotating Shafts: Part II — Experiment
Authors: Ulsoy A. Galip , Pierre Christophe , Choi Suhyun
Published: March 2021

This paper presents an experimental study of vibration localization in single-span, flexible, rotating shafts. It was shown in a companion paper (Part I) that a non-circular cross-section of the rotating shaft, leading to dissimilar lateral moments of inertia, can introduce disorder. Internal coupling between the principal directions of vibration is provided by the rotational speed through the gyroscopic moments. It is experimentally demonstrated here that directional vibration localization can occur for certain appropriate combinations of disorder and coupling. The steady state response, due to mass unbalance, of a simply supported rotating shaft is considered. It is shown that disorder and gyroscopic coupling lead to directional vibration localization; i.e., larger vibration amplitudes in one of the two orthogonal principal directions of the shaft cross section.
Active Vibration Control of a Triple Flexible Structures Combined With Actuators
Authors: Seto Kazuto , Toba Yoshihiro , Doi Fumio
Published: March 2021

In order to realize living comfort of tall buildings by reducing the vibration of higher floors by strong winds, this paper proposes a new method of vibration control for flexible structures with a large scale. The higher a tall building the lower its natural frequency. Since obtaining sufficient force to control the lower frequency vibrations of tall buildings is a difficult task, controlling the vibration of ultra-tall buildings using active dynamic absorbers is nearly impossible. This problem can be overcome by placing actuators between a pair of two or three ultra-tall buildings and using the vibrational force of each building to offset the vibrational movement of its paired mate. Therefore, it is able to obtain enough control force under the low frequency when the proposed method is used. In this paper, a reduced-order model expressed by 2DOF system under taking into consideration for preventing spillover instability is applied to control each flexible structure. The LQ control theory is applied to the design of such a control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.
Sliding Mode Control for Flexible Structures With μ Control-Based Frequency-Shaping Hyperplane
Authors: Nonami Kenzo , Nishimura Hidekazu
Published: March 2021

This paper proposes a new sliding mode control method using μ synthesis theory. This concept is based on the frequency-shaped approach. A conventional hyperplane consisits of a desired reference model without dynamics. Therefore, the sliding mode control system becomes often unstable based on spillover phenomena in a higher frequency region. On the other hand, the proposed design method can completely suppress such spillover phenomena because of the frequency-shaped hyperplane. Also, it has good robustness and robust performance in cases of parameter variations on the hyperplane to minimize the maximum singular value and structured sigular value from some noise to the controlled variables. We have just applied this new method to the flexible structure of the miniature test rig with four stories like high rise building. We have verified from simulations and experiments that the new sliding mode control method proposed in this paper has good performances and it is very useful to suppress the spillover in a higher frequency region.
The Trajectory Tracking Control of 2-Link Flexible Arm Using Tendon Mechanism
Authors: Cao Hui , Yoshida Kazuo
Published: March 2021

This paper deals with the trajectory tracking control of a 2-link flexible arm using tendon control mechanism. The purpose of this research is to establish modeling and control method for flexible arm. First, the equations of kinematic relationship and equations of motion are derived by using static deflection curve. From these equations, the relationship between tip trajectory and joint input torque is established. Second, a trajectory tracking controller is designed for real-time control of the flexible arm by using the resolved acceleration control method. Then the controller is carried out to track the designed straight line and circular trajectory. The simulation results show the effectiveness of the proposed method. To summarize these results, it was demonstrated that the tendon mechanism can be used to solve the tracking problem of the flexible arms and it also has a higher tracking precision than traditional method.
New Control Algorithms for Semi-Active Dynamic Vibration Absorbers
Authors: Abé M. , Igusa T.
Published: March 2021

A semi-active dynamic vibration absorber is proposed for controlling the free-vibration impulse response of structures. It is assumed that (i) the initial displacement for the absorber spring can be set to non-zero values and (ii) the viscous damping coefficient for the absorber damping can be adjusted. The theory is first developed for a single-degree-of-freedom structure, and is then generalized to continuous structures. The extensive use of closed-form analytical results provides useful insight into the complex interaction between the structure and absorber. This makes it possible to solve the design problem without recourse to numerical optimization. The semi-active vibration absorber is found to be far more effective than conventional passive devices.
Parametric Studies of Photo Deformation and Optical Actuation
Authors: Tzou H. S. , Chou C.-S.
Published: March 2021

Optically driven actuators can introduce remote actuation and control effects without any hard-wire connections. In this study, photostrictive {opto-piezoelectric) characteristics and photodeformation of distributed photostrictive optical actuators are investigated and a parametric study of design parameters is conducted. Photodeformation induced by the photostrictive (opto-piezoelectric) effect (a combination of the photovoltaic effect and the converse piezoelectric effect) is discussed and its two-dimensional (2-D) constitutive relations are presented. 2-D equivalent control forces and moments induced by the photodeformation effect of distributed actuators are formulated, and system governing equations derived. Static and dynamic applications are discussed, and simulation studies of design parameters are conducted and evaluated.
Orthogonal Bases for Eigenvalue Sensitivities—Torsional Vibration
Authors: Nayfeh S. A. , Asada H.
Published: March 2021

The sensitivity of the natural frequencies of torsional vibration of an initially uniform shaft to nonuniform changes in its radius is studied. For the particular example of a fixed-fixed shaft, a set of design changes are found that modify a single natural frequency without modifying any of the others. The possibility of finding such a set of design changes for general boundary conditions is then investigated, and conditions for the existence of such a set are determined.
On the Analysis and Fundamental Frequency of Slightly Curved Sandwich Beams With a Delamination
Authors: Rossettos John N.
Published: March 2021

An analysis of the vibration of sandwich beams with small iinitial curvature and a delamination between the core and face sheet is presented. The combined effects of initial curvature, transverse shear deformation and extent of delamination are evaluated and discussed. It is shown that the sensitivity to delamination damage is greater for straight beams than for initially curved beams. It is also greater for high modulus cores (less shear deformation). Also the influence of shear deformation on the fundamental frequency becomes smaller as the curvature increases.
A Comparison Between the Use of Physical Parameters and Correction Factors in Dynamic Model Updating
Authors: D’Ambrogio Walter , Fregolent Annalisa
Published: March 2021

The selection of quantities and/or variables that have to be corrected during the updating process is addressed in this paper. Among quantities, the major alternative is the choice between correction factors and physical parameters. The former represent scale factors used to adjust mass and stiffness submatrices of the analytical model, while the latter include parameters such as the elasticity modulus, mass density, geometrical dimensions, etc. Advantages and limitations in the process of updating physical parameters instead of correction factors are highlighted: it can be shown that only a limited number of physical parameters can be simultaneously updated for each element. The two approaches are compared using a previously developed updating procedure to solve an experimental test case.
Non-Linear Spring and Damping Forces Estimation During Free Vibration
Authors: Feldman Michael , Braun Simon
Published: March 2021

A method for dynamic analysis of sophisticated nonlinear single-degree-of-freedom systems, based on the Hilbert transform in the time domain is described. Using the Hilbert transform together with the proposed method for system identification, we obtain both instantaneous modal parameters together with non-linear force characteristics during free vibration analysis under impulse excitation without long resonance testing. Using the Hilbert transform in the time domain is a new method of studying linear and non-linear vibrating systems exposed to impulse or shock inputs.
Holographic Interferometry in Automotive Powertrain Component Engineering Analysis
Authors: Forbes James W. , Marchi Mitchell M. , Petniunas Alexander , Wales Raymond R.
Published: March 2021

As increased performance and vehicle system requirements are placed on automotive powertrains more sophisticated methods of engineering analysis are required in their development. Since the containment of noise and vibration is a major design requirement for powertrains, experimental techniques such as laser holographic interferometry are used to tune the dynamic response of system components. This allows the overall system to be optimized from a noise and vibration standpoint as well as from the standpoint of structural integrity. This paper will discuss a variety of examples of how powertrain components have been optimized with the use of holographic methodology.
Hybrid Holographic-Numerical Method for Vibration Studies
Authors: Der Hovanesian Joseph , Hung Y. Y. , Sherman Paul S.
Published: March 2021

This paper presents a hybrid experimental-numerical method for studying dynamic characteristic of vibrating structures. A continuous structure is first lumped into a number of discrete elements and its influence coefficients are measured by holographic interferometry. The eigen values and eigen vectors of the lumped system are then calculated. A major adavantage of the hybrid method is that it is not necessary to know material properties and idealize the boundary conditions, as the measured influcence coefficients will automatically reflect the real boundary and the material behaviors.
A method for realistic, conversational signal-to-noise ratio estimation
Authors: Mansour Naim , Marschall Marton , May Tobias , Westermann Adam , Dau Torsten
Published: March 2021

The analysis of real-world conversational signal-to-noise ratios (SNRs) can provide insight into people's communicative strategies and difficulties and guide the development of hearing devices. However, measuring SNRs accurately is challenging in everyday recording conditions in which only a mixture of sound sources can be captured. This study introduces a method for accurate in situ SNR estimation where the speech signal of a target talker in natural conversation is captured by a cheek-mounted microphone, adjusted for free-field conditions and convolved with a measured impulse response to estimate its power at the receiving talker. A microphone near the receiver provides the noise-only component through voice activity detection. The method is applied to in situ recordings of conversations in two real-world sound scenarios. It is shown that the broadband speech level and SNR distributions are estimated more accurately by the proposed method compared to a typical single-channel method, especially in challenging, low-SNR environments. The application of the proposed two-channel method may render more realistic estimates of conversational SNRs and provide valuable input to hearing instrument processing strategies whose operating points are determined by accurate SNR estimates.
Quantifying the influence of short-term emission reductions on climate
Authors: Fyfe J. C. , Kharin V. V. , Swart N. , Flato G. M. , Sigmond M. , Gillett N. P.
Published: March 2021

Emission reductions associated with pandemic containment are nowhere close to affecting climate and reducing global warming.
First Brazilian-made satellite watches the Amazon
Authors: Moutinho Sofia
Published: March 2021

Launch promises more deforestation data, but researchers fear government obstruction.
The genes behind the sexiest birds on the planet
Authors: Pennisi Elizabeth
Published: March 2021

Genomes from the tropical performers called manakins reveal the power of sexual selection.
Multidecadal climate oscillations during the past millennium driven by volcanic forcing
Authors: Mann Michael E. , Steinman Byron A. , Brouillette Daniel J. , Miller Sonya K.
Published: March 2021

A volcanic source of variation

The Atlantic Multidecadal Oscillation (AMO), a 50- to 70-year quasiperiodic variation of climate centered in the North Atlantic region, was long thought to be an internal oscillation of the climate system. Mann
et al.
now show that this variation is forced externally by episodes of high-amplitude explosive volcanism. They used an ensemble of climate models to evaluate the causes of the AMO, finding that volcanos are the most important influence, and that there is no evidence to show that it has been internally generated during the last millennium.

Science
, this issue p.
1014
Redox-active antibiotics enhance phosphorus bioavailability
Authors: McRose Darcy L. , Newman Dianne K.
Published: March 2021

Phenazines liberate phosphate

Bacteria secrete a wide range of small molecules with chemical reactivity that offers multiple functions in different contexts. Phenazines are commonly considered to be antibiotics, but they can also participate in environmental redox reactions, especially with iron. McRose and Newman found that phenazines, when added exogenously or made by bacteria in situ, can liberate phosphorous (P) in the form of phosphate from mineral surfaces, and that the production of these molecules is regulated by signaling pathways that respond to P limitation. Strains unable to produce these molecules grew more slowly under P limitation but could be rescued by the addition of exogenous phenazines. The authors hypothesize that reductive dissolution of iron oxides has the benefit of liberating P, and that this could be one mechanism of microbial P acquisition in some environments.

Science
, this issue p.
1033
Sub-Riemannian (2, 3, 5, 6)-Structures
Authors: Sachkov Yu. L. , Sachkova E. F.
Published: March 2021

We describe all Carnot algebras with growth vector (2, 3, 5, 6), their normal forms, an invariant that separates them, and a change of basis that transforms such an algebra into a normal form. For each normal form, Casimir functions and symplectic foliations on the Lie coalgebra are computed. An invariant and normal forms of left-invariant (2, 3, 5, 6)-distributions are described. A classification, up to isometries, of all left-invariant sub-Riemannian structures on (2, 3, 5, 6)-Carnot groups is obtained.
Novel case of a scleroderma-mimicking syndrome associated with gastrointestinal stromal tumour
Authors: Butt Zaran Ahmad , Ng Wan Lin , Osman Kamal , Howard Donough
Published: March 2021

We report a case of a 54-year-old man who developed an atypical systemic syndrome involving Raynaud’s phenomenon, pulmonary fibrosis and skin thickening. These features were initially suggestive of newly diagnosed scleroderma. However, he displayed atypical clinical features of same, antinuclear antibody was negative and symptoms were refractory to various immunosuppressive therapies. CT imaging revealed a gastric mass, which later proved to be a gastrointestinal stromal tumour (GIST). Resection of the GIST leads to minimal symptomatic improvement. Surveillance imaging 1 year later revealed metastatic deposits. He was subsequently initiated on imatinib therapy, which led to a rapid improvement in fibrotic changes within weeks. While there have been previous descriptions of paraneoplastic fibrotic disorders, this is the first description of a scleroderma mimic in the setting of a GIST. It highlights an important potential overlap in the pathogenesis of these disease processes and the potential efficacy of tyrosine kinase inhibitors for scleroderma-like fibrotic disorders.
Long-term outcomes of Boston keratoprosthesis type I: the Chinese People’s Liberation Army General Hospital experience
Authors: Wang Li-Qiang , Wu Teng-Yun , Chen Xiao-Niao , Xu Ze-Quan , Yang Min , Xiang Ran , Ma Xiao , Zhang Shan , Huang Yi-Fei
Published: March 2021

Purpose

To report the long-term outcomes of Boston keratoprosthesis type I (B-KPro type I) implantation in the management of severe ocular surface disorders.

Methods

Retrospective case series. Patients who underwent B-KPro type I implantation at the People’s Liberation Army General Hospital were enrolled between March 2011 and September 2019. Data regarding visual acuity (VA), B-KPro type I retention and postoperative complications were recorded and analysed.

Results

A total of 103 eyes of 100 patients who underwent B-KPro type I implantation were included. The main indications were chemical burn (59.2%), ocular trauma (25.2%), herpetic keratitis (11.7%) and autoimmune diseases (3.9%). The percentage of eyes with postoperative VA of 10/200 or better was 82.7% at 6 months, 82.8% at 12 months, 77.9% at 2 years, 72.4% at 3 years, 71.1% at 4 years, 69.4% at 5 years, 58.9% at 6 years, 56.8% at 7 years and 42.9% at 8 years. Preoperatively, 8.7% eyes were diagnosed with new-onset glaucoma. Retroprosthetic membrane formation occurred in 19.4% eye. Corneal melting occurred in 18.4% eyes. Sterile vitritis was diagnosed in 4.9% eyes and infectious endophthalmitis in 2.9% eyes. Retinal detachment occurred in 0.9% eyes.

Conclusions

In a Chinese patient group, B-KPro type I is a viable option for treating severe ocular surface disorders in eyes where conventional keratoplasty would have a poor prognosis, especially in patients with chemical and thermal burns. Improved visual outcomes and high retention rate can be achieved and maintained in most cases.
Use of saliva flow rate measurement in minor salivary glands autotransplantation for treatment of severe dry eye disease
Authors: Su Jia-Zeng , Wang Zhen , Liu Xiao-Jing , Lv Lan , Yu Guang-Yan
Published: March 2021

Aims

To use minor salivary glands’ flow rate (MSGFR) measurement in minor salivary glands (MSGs) autotransplantation for the treatment of severe dry eye disease (DED).

Methods

MSGs autotransplantations were performed in 18 eyes (17 patients) with severe DED. MSGFR were measured before operation. The upper or lower lip with higher MSGFR was selected as the donor site. Buccal mucosa was the back-up in cases labial MSGs showing markedly decreased MSGFRs. Two pieces of salivary lobules with the covering mucosa were harvested and transplanted to the recipient beds prepared in both upper and lower lids.

Results

The donor sites included lower lip in 12 eyes, upper lip in 5 eyes and buccal mucosa in 1 eye. Postoperative follow-up confirmed viable grafts in all cases. The overall subjective relief rate of DED symptoms was 58.8%, with Schirmer test values increasing from 0 mm to 4 mm (p<0.05). The mean preoperative MSGFR was 1.7 (range: 0.9–3.3) µL/min/cm2. ROC analysis indicated an outstanding discrimination power for preoperative MSGFR to predicate postoperative relief of DED symptoms (area under the curve (AUC)=0.948, p<0.01). The maximum sensitivity (100%) and specificity (72.7%) were reached at a cut-off of 1.785 µL/min/cm2. Patients with preoperative MSGFR >1.785 µL/min/cm2showed greater improvement of Schirmer test values after surgery than those with MSGFR ≤1.785 µL/min/cm2(p<0.05).

Conclusion

MSGs transplantation proved to be useful for treating severe DED. The amount of postoperative lubrication and the treatment effect were positively correlated with preoperative MSGFR. MSGFR measurement and donor-site selection should be critical steps before the operation.
Ambient air pollution and risk of respiratory infection among adults: evidence from the multiethnic study of atherosclerosis (MESA)
Authors: Kirwa Kipruto , Eckert Carly M , Vedal Sverre , Hajat Anjum , Kaufman Joel D
Published: March 2021

Background

Air pollution may affect the risk of respiratory infection, though research has focused on uncommon infections or infections in children. Whether ambient air pollutants increase the risk of common acute respiratory infections among adults is uncertain, yet this may help understand whether pollutants influence spread of pandemic respiratory infections like COVID-19.

Objective

To estimate the association between ambient air pollutant exposures and respiratory infections in adults.

Methods

During five study examinations over 12 years, 6536 participants in the multiethnic study of atherosclerosis (MESA) reported upper respiratory tract infections, bronchitis, pneumonia or febrile illness in the preceding 2 weeks. Using a validated spatiotemporal model, we estimated residential concentrations of ambient PM2.5, NOxand NO2for the 2–6 weeks (short-term) and year (long-term) prior to each examination.

Results

In this population aged 44–84 years at baseline, 10%–32% of participants reported a recent respiratory infection, depending on month of examination and study region. PM2.5, NOxand NO2concentrations over the prior 2–6 weeks were associated with increased reporting of recent respiratory infection, with risk ratios (95% CIs) of 1.04 (1.00 to 1.09), 1.15 (1.10 to 1.20) and 1.21 (1.10 to 1.33), respectively, per increase from 25th to 75th percentile in residential pollutant concentration.

Conclusion

Higher short-term exposure to PM2.5and traffic-related pollutants are associated with increased risk of symptomatic acute respiratory infections among adults. These findings may provide an insight into the epidemiology of COVID-19.
A systematic mixed studies review of patient experiences in the ED
Authors: Bull Claudia , Latimer Sharon , Crilly Julia , Gillespie Brigid M
Published: March 2021

Background

Understanding patient experiences is crucial to evaluating care quality in EDs. However, while previous reviews describe the determinants of ED patient experiences (ie, factors that influence patient experiences), few have described actual patient experiences. The aim of this systematic mixed studies review was to describe patient experiences in the ED from the patient’s perspective.

Methods

Embase, Medline, ProQuest Nursing and Allied Health, the Cumulative Index to Nursing and Allied Health Literature and the Cochrane Library electronic databases were searched, with publication dates limited between 1 January 2001 and 16 September 2019. Studies describing adult patient experiences in the ED were included. Studies describing patient satisfaction, proxy-reported experiences or child/adolescent experiences were excluded. The quality of included studies was appraised using the Mixed Methods Appraisal Tool (2018 version). An inductive, convergent qualitative synthesis of the extracted data was undertaken following Thomas and Harden’s (2008) methods.

Results

Fifty-four studies were included and of those, only five (9%) studies included a standardised definition of patient experience. Two inter-related themes emerged:Relationships between ED patients and care providers; andSpending time in the ED environment. The first theme included four subthemes regarding respect, communication, caring behaviours and optimising patient confidence. A key finding related to the potential for power imbalances between patients and their care providers. The second theme included two subthemes regarding physical aspects of the ED environment and patients’ waiting experience. Patients attributed more importance to the waiting experience itself rather than the duration they had to wait.

Conclusions

Patients in the ED have unique and complex experiences. Greater research is needed to understand the relational and environmental factors that contribute to power imbalances between patients and care providers, how to support more positive waiting experiences, and developing a standardised definition of patient experience in the ED.

PROSPERO registration number

CRD42020150154.
ESE3/EHF, a promising target of rosiglitazone, suppresses pancreatic cancer stemness by downregulating CXCR4
Authors: Zhou Tianxing , Liu Jing , Xie Yongjie , Yuan Shuai , Guo Yu , Bai Weiwei , Zhao Kaili , Jiang Wenna , Wang Hongwei , Wang Haotian , Zhao Tiansuo , Huang Chongbiao , Gao Song , Wang Xiuchao , Yang Shengyu , Hao Jihui
Published: March 2021

Background and aims

The crosstalk between cancer stem cells (CSCs) and their niche is required for the maintenance of stem cell-like phenotypes of CSCs. Here, we identified E26 transformation-specific homologous factor (EHF) as a key molecule in decreasing the sensitivity of pancreatic cancer (PC) cells to CSCs’ niche stimulus. We also explored a therapeutic strategy to restore the expression of EHF.

Design

We used a LSL-KrasG12D/+mice, LSL-Trp53R172H/+and Pdx1-Cre (KPC) mouse model and samples from patients with PC. Immunostaining, flow cytometry, sphere formation assays, anchorage-independent growth assay, in vivo tumourigenicity, reverse transcription PCR, chromatin immunoprecipitation (ChIP) and luciferase analyses were conducted in this study.

Results

CXCL12 derived from pancreatic stellate cells (PSCs) mediates the crosstalk between PC cells and PSCs to promote PC stemness. Tumorous EHF suppressed CSC stemness by decreasing the sensitivity of PC to CXCL12 stimulus and inhibiting the crosstalk between PC and CSC-supportive niches. Mechanically, EHF suppressed the transcription of the CXCL12 receptor CXCR4. EHF had a cell autonomous role in suppressing cancer stemness by inhibiting the transcription ofSox9,Sox2,Oct4andNanog. Rosiglitazone suppressed PC stemness and inhibited the crosstalk between PC and PSCs by upregulating EHF. Preclinical KPC mouse cohorts demonstrated that rosiglitazone sensitised PDAC to gemcitabine therapy.

Conclusions

EHF decreased the sensitivity of PC to the stimulus from PSC-derived CSC-supportive niche by negatively regulating tumorous CXCR4. Rosiglitazone could be used to target PC stem cells and the crosstalk between CSCs and their niche by upregulating EHF.
Defining indicators for drug overdose emergency department visits and hospitalisations in ICD-10-CM coded discharge data
Authors: Vivolo-Kantor Alana , Pasalic Emilia , Liu Stephen , Martinez Pedro D , Gladden Robert Matthew
Published: March 2021

Introduction

The drug overdose epidemic has worsened over the past decade; however, efforts have been made to better understand and track nonfatal overdoses using various data sources including emergency department and hospital admission data from billing and discharge files.

Methods and findings

The Centers for Disease Control and Prevention (CDC) has developed surveillance case definition guidance using standardised discharge diagnosis codes for public health practitioners and epidemiologists using lessons learnt from CDC’s funded recipients and the Council for State and Territorial Epidemiologists (CSTE) International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) Drug Poisoning Indicators Workgroup and General Injury ICD-10-CM Workgroup. CDC’s guidance was informed by health departments and CSTE’s workgroups and included several key aspects for assessing drug overdose in emergency department and hospitalisation discharge data. These include: (1) searching all diagnosis fields to identify drug overdose cases; (2) estimating drug overdose incidence using visits for initial encounter but excluding subsequent encounters and sequelae; (3) excluding underdosing and adverse effects from drug overdose incidence indicators; and (4) using codes T36–T50 for overdose surveillance. CDC’s guidance also suggests analysing intent separately for ICD-10-CM coding.

Conclusions

CDC’s guidance provides health departments a key tool to better monitor drug overdoses in their community. The implementation and validation of this standardised guidance across all CDC-funded health departments will be key to ensuring consistent and accurate reporting across all entities.
High efficiency and clinical relevance of exome sequencing in the daily practice of neurogenetics
Authors: Thomas Quentin , Vitobello Antonio , Tran Mau-Them Frederic , Duffourd Yannis , Fromont Agnès , Giroud Maurice , Daubail Benoit , Jacquin-Piques Agnès , Hervieu-Begue Marie , Moreau Thibault , Osseby Guy-Victor , Garret Philippine , Nambot Sophie , Delanne Julian , Bruel Ange-Line , Sorlin Arthur , Callier Patrick , Denomme-Pichon Anne-Sophie , Faivre Laurence , Béjot Yannick , Philippe Christophe , Thauvin-Robinet Christel , Moutton Sébastien
Published: March 2021

Objective

To assess the efficiency and relevance of clinical exome sequencing (cES) as a first-tier or second-tier test for the diagnosis of progressive neurological disorders in the daily practice of Neurology and Genetic Departments.

Methods

Sixty-seven probands with various progressive neurological disorders (cerebellar ataxias, neuromuscular disorders, spastic paraplegias, movement disorders and individuals with complex phenotypes labelled ‘other’) were recruited over a 4-year period regardless of their age, gender, familial history and clinical framework. Individuals could have had prior genetic tests as long as it was not cES. cES was performed in a proband-only (60/67) or trio (7/67) strategy depending on available samples and was analysed with an in-house pipeline including software for CNV and mitochondrial-DNA variant detection.

Results

In 29/67 individuals, cES identified clearly pathogenic variants leading to a 43% positive yield. When performed as a first-tier test, cES identified pathogenic variants for 53% of individuals (10/19). Difficult cases were solved including double diagnoses within a kindred or identification of a neurodegeneration with brain iron accumulation in a patient with encephalopathy of suspected mitochondrial origin.

Conclusion

This study shows that cES is a powerful tool for the daily practice of neurogenetics offering an efficient (43%) and appropriate approach for clinically and genetically complex and heterogeneous disorders.
New-onset refractory status epilepticus (NORSE)
Authors: Mantoan Ritter Laura , Nashef Lina
Published: March 2021

New-onset refractory status epilepticus and its subcategory febrile infection-related epilepsy syndrome are rare devastating clinical presentations in those without pre-existing relevant history, often in schoolchildren or young adults, without a clear cause on initial investigations. A cause is later identified in up to half of adults, but in many fewer children. Patients often require protracted intensive care and are at significant risk of dying. Functional disability is common and subsequent chronic epilepsy is the norm, but some people do have good outcomes, even after prolonged status epilepticus. Patients need prompt investigations and treatment. Anaesthetic and antiseizure medications are supplemented by other treatment modalities, including the ketogenic diet. Despite limited evidence, it is appropriate to try to modify the presumed underlying pathogenesis with immune modulation early, with a more recent focus on using interleukin inhibitors. Optimising management will require concerted multicentre international efforts.
Quantifying the vertical diversification development stage of old-growth Douglas-fir to derive stage-specific targets for restoration silviculture
Authors: Zenner Eric K. , Peck JeriLynn E.
Published: March 2021

Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size structures of live trees across a developmental sequence of 10 pristine stands in the Oregon Cascades, USA. Floating neighborhoods were used to delineate natural tree neighborhoods based on triangulated irregular networks in five concentric rings of ever-greater spatial extent (averaging 60–2060 m2). Diameter distributions summarized the most frequently encountered tree size structures among neighborhoods, with increasing deviation from the neutral multi-variate core. Of 18 observed diameter distribution types (DDTs), the core DDT characterized all-sized tree neighborhoods reflective of vertical diversification, which was most abundant in early old-growth (VD) stands and least abundant at the extremes of the sequence. VD declined in older stands, whose more distinct DDTs had peaks in larger trees and multiple size classes, likely reflecting horizontal diversification (HD). This new approach illustrates that structural restoration of VD stands could be facilitated by the single-tree selection method, while that of HD stands may be promoted with both single-tree and group selection as well as targeted release.
Erratum to: The new physics reach of null tests with $$D \rightarrow \pi \ell \ell $$ and $$D_s \rightarrow K \ell \ell $$ decays
Authors: Bause Rigo , Golz Marcel , Hiller Gudrun , Tayduganov Andrey
Published: March 2021

A Correction to this paper has been published: https://doi.org/10.1140/epjc/s10052-020-7621-7.
Electric field distribution of Ag@CuO and Ag@ZnO core–shell dimer
Authors: Li Guoli , Chen Haixia , Ding Jijun
Published: March 2021

The effect of shape, material and shell thickness on electric field distribution of both Ag@CuO and Ag@ZnO core–shell dimer is investigated. First, three core–shell structures, including plane@circle, triangle@circle and quadrilateral@circle are designed. The field enhancement advantages of the quadrilateral@circle structures are summarized by analyzing the electric field distribution diagrams. Then the influence of materials on the field enhancement effect of core–shell dimer is discussed. The results show that Ag@CuO structure has better stability, while Ag@ZnO structure have larger electric field enhancement. Finally, the shell thickness is changed from 0.1 nm to 1.5 nm. We found that the X-component electric field of both the Ag@ZnO and Ag@CuO core–shell dimer structure is decreased with the increase in the shell thickness. Also, the X-component electric field of Ag@ZnO core–shell dimer is about five times than that of the Ag@CuO. The increase of electric field indicated that Ag@ZnO core–shell dimer has strong local surface plasma resonance characteristics.
Forced Vibration Responses of Smart Composite Plates using Trigonometric Zigzag Theory
Authors: Chanda Aniket , Sahoo Rosalin
Published: March 2021

The Trigonometric Zigzag theory is utilized in this research for analytically evaluating the forced vibration responses of smart multilayered laminated composite plates with piezoelectric actuators and sensors. This theory, as the name suggests, incorporates a trigonometric function, namely the secant function for describing the nonlinear behavior of transverse shear stresses through the thickness of the smart composite plates. The kinematics for the in-plane displacement components are obtained by superposing a globally varying nonlinear field through the thickness of the plate structure on a piecewise linearly varying zigzag field with slope discontinuities at the layer interfaces. The model also satisfies the inter-laminar continuity conditions of tractions at the interfaces of the multilayered plate. The equations of motion are derived using Hamilton’s principle, and the separation of the variables technique is extended to assume the solutions for the primary variables in space and time and solved analytically using Navier’s solution technique along with Newmark’s time integration scheme. A detailed analytical investigation of the dynamic behavior of the smart laminated plate coupled with piezoelectric materials like PVDF and piezoelectric fiber-reinforced composite (PFRC) is carried out by considering several forms of the time-dependent electromechanical excitations and also covering different geometrical and material features of the smart plate structure. The responses are found to be in close agreement with the elasticity solutions and some new results are also presented to show the dynamic controlling capacity of the piezoelectric layers.
Internal Short Circuit Analysis of Cylindrical Lithium-Ion Cells Due to Structural Failure
Authors: Sheikh Muhammad , Elmarakbi Mohab , Rehman Sheikh , Elmarakbi Ahmed
Published: March 2021

Battery failures are obvious after being subject to abuse conditions however predicting these failures in advance is crucial when using test and validation techniques to understand battery potential. Lithium-ion battery cells are widely used due to their high energy and power densities. When abusive conditions like the three-point bend loading are applied to lithium-ion batteries, what occurs to the mechanical behaviours and components is still mostly unknown. To further this understanding, this paper investigates the mechanical behaviour of the separator in the LiCoO2/Graphite cylindrical 18650 cells. Internal short circuit (ISC) behaviour, strain rate dependency, and electrochemical status of the cells (i.e. SOC dependency) are studied to understand failure patterns. Furthermore, a simple and effective constitutive model for the separator layer is formed, facilitating further mechanical analysis and numerical simulation of lithium-ion battery study. The occurrence of ISC is investigated by jellyroll deformation where the casing is removed, and quasi-static load is applied. A numerical simulation model is developed to further investigate sequential structural failures and temperature changes. Simulation results showed good accuracy with experimental results and are useful to predict structural failure of cells. The number of failures including electrolyte leakage, change in shape, sudden voltage drop/temperature rise, and gas venting is observed.
Perspective—Combining Physics and Machine Learning to Predict Battery Lifetime
Authors: Aykol Muratahan , Gopal Chirranjeevi Balaji , Anapolsky Abraham , Herring Patrick K. , van Vlijmen Bruis , Berliner Marc D. , Bazant Martin Z. , Braatz Richard D. , Chueh William C. , Storey Brian D.
Published: March 2021

Forecasting the health of a battery is a modeling effort that is critical to driving improvements in and adoption of electric vehicles. Purely physics-based models and purely data-driven models have advantages and limitations of their own. Considering the nature of battery data and end-user applications, we outline several architectures for integrating physics-based and machine learning models that can improve our ability to forecast battery lifetime. We discuss the ease of implementation, advantages, limitations, and viability of each architecture, given the state of the art in the battery and machine learning fields.
Study on Identifying Significant Risk Sources during Bridge Construction Based on Grey Entropy Correlation Analysis Method
Authors: Wang Kunpeng , Lu Chenggang , Li Qingfu
Published: March 2021

Nowadays, many methods have been used in the identification of bridge risk sources, and certain results have been achieved. However, the research on the identification of significant risk sources of bridges during the construction period is relatively weak, and these methods still have some defects, such as the correlation between risk sources is not considered comprehensively, the dynamic risk sources are not fully considered, and the weight assignment is highly subjective. In order to solve these problems, this paper comprehensively uses the combination of expert scoring method, fuzzy analytic hierarchy process (F-AHP), and grey entropy correlation analysis (GECA) to identify significant risk sources during bridge construction. Firstly, the F-AHP and expert scoring method are used to initially identify safety sources during the bridge construction period, which effectively considers the identification of dynamic risk sources. Secondly, the combination of the GRA method and EW method is applied to identify the significant risk sources during bridge construction period, which can effectively analyze the interrelationship between different factors and greatly reduce the interference of subjective factors in the weight assignment, so as to effectively control the risks in construction and protect the health of the bridge structure and property losses. Finally, the feasibility and rationality of the proposed method were verified by comparing the AHP and GECA proposed in this paper in combination with specific engineering examples, which provides a reference basis for the identification of significant risk sources during the follow-up bridge construction period.
An Efficient Algorithm for Solving Hyperbolic Partial Differential Equations with a Nonlocal Conservation Condition
Authors: Bin Jebreen H.
Published: March 2021

In this paper, a numerical scheme based on the Galerkin method is extended for solving one-dimensional hyperbolic partial differential equations with a nonlocal conservation condition. To achieve this goal, we apply the interpolating scaling functions. The most important advantages of these bases are orthonormality, interpolation, and having flexible vanishing moments. In other words, to increase the accuracy of the approximation, we can individually or simultaneously increase both the degree of polynomials (multiplicity

r

) and the level of refinement (refinement level

J

). The convergence analysis is investigated, and numerical examples guarantee it. To show the ability of the proposed method, we compare it with existing methods, and it can be confirmed that our results are better than them.
Function and Mechanism of Novel Histone Posttranslational Modifications in Health and Disease
Authors: Xu Huiwen , Wu Maoyan , Ma Xiumei , Huang Wei , Xu Yong
Published: March 2021

Histone posttranslational modifications (HPTMs) are crucial epigenetic mechanisms regulating various biological events. Different types of HPTMs characterize and shape functional chromatin states alone or in combination, and dedicated effector proteins selectively recognize these modifications for gene expression. The dysregulation of HPTM recognition events takes part in human diseases. With the application of mass spectrometry‐ (MS‐) based proteomics, novel histone lysine acylation has been successively discovered, e.g., propionylation, butyrylation, 2‐hydroxyisobutyrylation, β‐hydroxybutyrylation, malonylation, succinylation, crotonylation, glutarylation, and lactylation. These nine types of modifications expand the repertoire of HPTMs and regulate chromatin remodeling, gene expression, cell cycle, and cellular metabolism. Recent researches show that HPTMs have a close connection with the pathogenesis of cancer, metabolic diseases, neuropsychiatric disorders, infertility, kidney diseases, and acquired immunodeficiency syndrome (AIDS). This review focuses on the chemical structure, sites, functions of these novel HPTMs, and underlying mechanism in gene expression, providing a glimpse into their complex regulation in health and disease.
Nonlinear Vibration Analysis of Rotor considering Cogging and Harmonic Effects
Authors: Li Shanle , Liu Feng , Wang Hongyan , Song Haijun , Yu Kuilong
Published: March 2021

This paper aims to investigate nonlinear vibration characteristics of rotor system considering cogging and harmonic effects. Firstly, relative permeance with eccentric was established and then corrected by correction factor caused by the cogging effect. Based on the new formula of relative permeance, the expression of unbalanced magnetic force was obtained, and the coefficient of cogging effect was defined. Motion equations of rotor system were established, and Runge–Kutta method was used to solve the equations. Results showed that errors between finite and analytical results were smaller considering cogging and harmonic effects. When the harmonics were taken into consideration, the vibration of rotor increases sharply. When the cogging and harmonics were taken into consideration simultaneously, the vibration of rotor decreased instead, which means that stator slots have the effect of reducing vibration in rotor system. Rotor vibration was axis symmetry with static eccentricity rather than central symmetry with no eccentricity, and double, four times, and six times supply frequency always existed in the components of main frequency with eccentric.
Equivalent SDOF Load Transformation Factors for One‐Way Members Subjected to Air Blast Loading
Authors: He Yaobei , Geng Shaobo , Wei Yaxin , Luo Gan , Gong Xin , Mao Huifeng
Published: March 2021

The equivalent single‐degree‐of‐freedom (SDOF) load transformation factor expressions of the simply supported, fixed end and simply‐fixed one‐way members subjected to air blast loading are derived by finite series‐expansion method or finite point‐fitting method. Moreover, figures are used to show the relative relationship between the load transformation factors KL and the ratio of stand‐off distance to structural span (γ). The typical calculation conditions show that the load transformation factors are sensitive to the piecewise function of peak overpressure when γ is less than 0.5. The load transformation factor will be a smooth curve for peak overpressure adopting a single smooth continuous function. For the blast‐resistant structural design, if the error of 3% in the elastic stage and 5% in the plastic stage can be allowed, γ = 1.0 is the demarcation point between near field blast and far field blast. In addition, if the error of 0.5% can be allowed, γ ≥ 2.0 can be treated as the far field blast. The calculation results of far field blast show that the values of KL of simply supported, simply‐fixed, and fixed‐end members are 0.64, 0.58, and 0.54, respectively, which means that the load transformation factor is insensitive to the selection of shape function in vibration mode function or static deflection curve function. The calculation accuracy of KL expression for simply supported beam structure in this paper has been verified through near field blast experiments. This paper provides a clear numerical definition for the distinction between near field and far field explosions. It provides qualification criteria for analyzing explosion categories in blast‐resistant structural design and a reference for the selection of theoretical calculation formulas.