bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermomanometric system for diagnosing the technical condition of the ESP by the level of its vibration
Authors: Zainagalina L Z , Dumler E B 
Published: February 2021

Abstract
The article presents the results of the analysis of the main vibration causes of a submersible electric centrifugal pump and its consequences. It gives recommendations for minimizing the vibration with the installation of an electric centrifugal pump (ESP). The article analyzes the problem of breaks’ occurrence in the submersible unit assemblies is a result of the influence of various factors during the operation of the ESP. This type of failure is the most dangerous, since the fall of equipment to the bottom of the well is accompanied by damage to pump unit assemblies, cable rupture, jamming of equipment in the casing, and blockage of the filtration zone. Elimination of such accidents is characterized by significant costs for lifting the fallen equipment and restoring the bottom of the well, while the economic losses associated with an increase in the volume of work and the time of the forced downtime of the well increases significantly. The research identifies a number of reasons causing the accident, carries out the analysis of existing techniques and methods of eliminating “flights”, and proposes a telemetry device to solve this problem.
Bulk and interface second harmonic generation in the Si3N4 thin films deposited via ion beam sputtering
Authors: Das Nirmal Kumar , Kanclíř Vít , Mokrý Pavel , Žídek Karel 
Published: February 2021

Abstract
The nonlinear optical second harmonic generation (SHG) in Si3N4 has attracted considerable attention due to a variety of promising applications in optoelectronics. However, reports on SHG in Si3N4 thin films and microstructures lead to diverse conclusions about the SHG origin, pointing towards the Si3N4 bulk, as well as to the Si3N4–Si interface. Here we report on the measurement of polarization-resolved angle-dependent SHG in Si3N4 thin films in the reflective mode. This mode allowed us to measure the nonlinear response of Si3N4 thin films on the Si single crystal substrate. By measuring three samples deposited via ion beam sputtering, we were able to analyze the bulk and interface contributions. We have demonstrated that apart from the bulk SHG, the Si3N4–Si interface contributes with a significant amount of SHG for the thin sample (600 nm). Our result provides a link between the previous measurements in the Si3N4 thin films and on the microstructures.
Simulation of carriers spatial distribution and transportation in co-mixing composition perovskite for solar cell
Authors: Li Guangdong , Zou Xiaoping , Cheng Jin , Yu Xing , Zhou Zixiao , Wang Junqi , Liu Baoyu , Chen Dan 
Published: February 2021

Abstract
A planar device structure FTO/TiO2/SnO2/Cs0.1[HC(NH 2)2]0.74(CH3NH3)0.13PbI2.48Br0.39(Cs0.1FA0.74MA0.13PbI2.48Br0.39)/CuSCN/Au with cation and anion co-mixed Cs0.1FA0.74MA0.13PbI2.48 Br0.39 as light harvester was modeled and investigated by using modeling program wxAMPS. The energy band structure, carrier concentration, carrier generation rate, recombination rate, and other data were obtained through simulation to analyze the specific influence on the performance of perovskite solar cells (PSCs). In order to better optimize device performance, we investigated the effects of perovskite and the interface between each functional layer defect density, film thickness, and test temperature environment on the performance of PSCs. The simulation results show that the device performance has higher dependence on the effect of perovskite and interface defect density. By further optimizing the parameters of defect density (1013 cm−3), film thickness (400 nm), and test temperature (300 K), the power conversion efficiency (PCE) of the finally obtained PSCs was enhanced from the initial 11.65% to 21.95%. This investigation will enable us to better understand the internal working mechanism of PSCs and provide theoretical guidance for the fabrication of high-performance PSCs in experiments.
Effects of nitrogen element on microstructure and pitting corrosion resistance of duplex stainless steel welded joints
Authors: Zhang* Yingying , Liu* Zhengjun , Jin Meiling , Song Shuang 
Published: February 2021

Abstract
The microstructure, element distribution and pitting corrosion resistance of Gas Tungsten arc welding (GTAW) duplex stainless steel welded joints under 100% argon (Ar) and 98% Ar + 2% nitrogen (N2) shielding gas were studied by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and electrochemical corrosion methods. These results show that the addition of N2 to the shielding gas promotes the formation of austenite (γ) phase in the weld joint. Also, the austenite phase distribution is dendritic and the ferrite (δ) and austenite phases in the heat-affected zone are no longer banded structures. Moreover, the austenite phase in the welded joint is enriched in nickel (Ni) and nitrogen (N) elements, while the ferrite phase is enriched in chromium (Cr) and molybdenum (Mo) elements. The pitting corrosion index (PREN) of the austenite/ferrite (δ/α) phase boundary is lower than that of δ and γ phases, which leads to their preferential corrosion. The appearance of chromium nitride (Cr2N) decreases the corrosion resistance of the weld seam and the heat affected zone. N2 in the 98% Ar + 2% N2 shielding gas can restrain Cr2N precipitation, increase the pitting corrosion index of secondary austenite structure (γ
2), and improve the pitting corrosion resistance of welded joints.
Modification of TiO2 with metal chalcogenide nanoclusters for hydrogen evolution
Authors: Rhatigan Stephen , Niemitz Lorenzo , Nolan Michael 
Published: February 2021

Abstract
Using density functional theory, corrected for on-site Coulomb interactions (DFT + U), we have investigated surface modification of TiO2 with metal chalcogenide nanoclusters for hydrogen evolution. The nanoclusters have composition M4X4 (M = Sn, Zn; X = S, Se) and are adsorbed at the rutile (110) surface. The nanoclusters adsorb exothermically, with adsorption energies in the range −2.8 eV to −2.5 eV. Computed density of states (DOS) plots show that cluster-derived states extend into the band-gap of the rutile support, which indicates that modification produces a redshift in light absorption. After modification, photoexcited electrons and holes are separated onto surface and cluster sites, respectively. The free energy of H adsorption is used to assess the performance of metal chalcogenide modified TiO2 as a catalyst for the hydrogen evolution reaction (HER). Adsorption of H at nanocluster (S, Se) and surface (O) sites is considered, together with the effect of H coverage. Adsorption free energies at cluster sites in the range −0.15 eV to 0.15 eV are considered to be favourable for HER. The results of this analysis indicate that the sulphide modifiers are more active towards HER than the selenide modifiers and exhibit hydrogen adsorption free energies in the active range, for most coverages. Conversely, the adsorption free energies at the selenide nanoclusters are only in the active range at low H coverages. Our results indicate that surface modification with small, dispersed nanoclusters of appropriately selected materials can enhance the photocatalytic activity of TiO2 for HER applications.
Nano-mediated uniform ternary Cu–Co–Ni-based nitrogen-doped carbon nanotubes with synergistic reactivity for high-performance oxygen reduction
Authors: Gao Cunyuan , Huai Jie , Ma Kongshuo , Lu Yizhong , Zhao Zhenlu 
Published: February 2021

Abstract
Here, we report nano-mediated Cu–Co–Ni-based nitrogen-doped carbon nanotubes (N-CNTs/T-CCN) by hydrothermal and procedural calcination strategy. The nitrogen-doped carbon nanotubes (N-CNTs) show more average diameter and the N-CNTs are uniformly modified with ternary Cu–Co–Ni-based nanoparticles (T-CCN). The hybrid exhibits excellent ORR catalytic activity. The onset potential (Eonset) and half-wave potential (E1/2) are 0.96 V and 0.87 V (versus reversible hydrogen electrode, RHE) in 0.1 M KOH. Most importantly, compared to 20% Pt/C, N-CNTs/T-CCN catalyst displays better methanol tolerance and higher stability. The H2O2 yield of the N-CNTs/T-CCN is less than 7.5% and the electron-transfer number (n) is about 3.9. High ORR performance may be related to the synergistic enhancement effect. The N-CNTs supply good electrical conductivity and allow large numbers of active sites to efficiently participate; the T-CCN can improve the local work function of the N-CNTs by synergistic electronic interaction and promote O2 adsorption; the stability of embedded T-CCN can be greatly improved, mainly due to the weakness of Ostwald effect. All these advantages make the hybrid a promising ORR catalyst.
Leukocyte immunoglobulin-like receptor subfamily B: therapeutic targets in cancer
Authors: Deng Mi , Chen Heyu , Liu Xiaoye , Huang Ryan , He Yubo , Yoo Byounggyu , Xie Jingjing , John Samuel , Zhang Ningyan , An Zhiqiang , Zhang Cheng Cheng 
Published: February 2021

AbstractInhibitory leukocyte immunoglobulin-like receptors (LILRBs 1–5) transduce signals via intracellular immunoreceptor tyrosine-based inhibitory motifs that recruit phosphatases to negatively regulate immune activation. The activation of LILRB signaling in immune cells may contribute to immune evasion. In addition, the expression and signaling of LILRBs in cancer cells especially in certain hematologic malignant cells directly support cancer development. Certain LILRBs thus have dual roles in cancer biology—as immune checkpoint molecules and tumor-supporting factors. Here, we review the expression, ligands, signaling, and functions of LILRBs, as well as therapeutic development targeting them. LILRBs may represent attractive targets for cancer treatment, and antagonizing LILRB signaling may prove to be effective anti-cancer strategies.
Breath analysis for the detection of digestive tract malignancies: systematic review
Authors: Hintzen K F H , Grote J , Wintjens A G W E , Lubbers T , Eussen M M M , van Schooten F J , Bouvy N D , Peeters A 
Published: February 2021

Abstract

Background
In recent decades there has been growing interest in the use of volatile organic compounds (VOCs) in exhaled breath as biomarkers for the diagnosis of multiple variants of cancer. This review aimed to evaluate the diagnostic accuracy and current status of VOC analysis in exhaled breath for the detection of cancer in the digestive tract.

Methods
PubMed and the Cochrane Library database were searched for VOC analysis studies, in which exhaled air was used to detect gastro-oesophageal, liver, pancreatic, and intestinal cancer in humans, Quality assessment was performed using the QUADAS-2 criteria. Data on diagnostic performance, VOCs with discriminative power, and methodological information were extracted from the included articles.

Results
Twenty-three articles were included (gastro-oesophageal cancer n = 14, liver cancer n = 1, pancreatic cancer n = 2, colorectal cancer n = 6). Methodological issues included different modalities of patient preparation and sampling and platform used. The sensitivity and specificity of VOC analysis ranged from 66.7 to 100 per cent and from 48.1 to 97.9 per cent respectively. Owing to heterogeneity of the studies, no pooling of the results could be performed. Of the VOCs found, 32 were identified in more than one study. Nineteen were reported as cancer type-specific, whereas 13 were found in different cancer types. Overall, decanal, nonanal, and acetone were the most frequently identified.

Conclusion
The literature on VOC analysis has documented a lack of standardization in study designs. Heterogeneity between the studies and insufficient validation of the results make interpretation of the outcomes challenging. To reach clinical applicability, future studies on breath analysis should provide an accurate description of the methodology and validate their findings.
Advances in the management of generalized convulsive status epilepticus: what have we learned?
Authors: Neligan, Aidan , Rajakulendran Sanjeev , Walker Matthew C 
Published: February 2021

AbstractConvulsive status epilepticus is the most serious manifestation of an epileptic diathesis. In the early stages (5–30 min), there exists class A evidence to support the efficacy of benzodiazepines as first-line treatment. As status epilepticus progresses into the later stages, the evidence for treatment becomes less robust until we are depending upon short case series and case reports for the treatment of refractory status epilepticus. However, the past year saw the publication of three randomized controlled trials in the setting of benzodiazepine-resistant established convulsive status epilepticus: the EcLiPSE and ConSEPT studies, compared levetiracetam to phenytoin in children; and the ESETT study compared fosphenytoin, levetiracetam and sodium valproate in adults and children. In addition, the emergence of data from the SENSE study, a multicentre multinational prospective cohort study and the publication of a systematic review and meta-analysis of the mortality of status epilepticus over the past 30 years, has brought the treatment of status epilepticus into sharp focus. In this update we provide a detailed analysis of these studies and their impact on clinical practice. We review contentious areas of management in status epilepticus where a consensus is lacking and advance the case for more research on existing and alternative treatment strategies.
Optimized Chromatographic Determination of Naphazoline and Chlorpheniramine in Eye/Nose Drops Using Cation-exchange Column
Authors: Reid Imad Osman Abu 
Published: February 2021

Abstract
A simple and efficient liquid chromatographic method has been developed and validated for the simultaneous determination of naphazoline and chlorpheniramine in eye/nose drops, in presence of naphazoline degradation product and naphthalene acetic acid (NAPD). The separation was achieved within 6.0 min, employing a mixture of 53.5% v/v water-acetonitrile containing 78.70 mM/L sodium dihydrogen orthophosphate adjusted to pH 5.30 as isocratic mobile phase, pumped at 1.0 mL/min through a strong cation-exchange column (10 μm particle size), the analytes were monitored at 230 nm. Statistical experimental designs and graphic representations (response surface methodology) were used for optimizing the chromatographic separation. The linearity plots were linear over concentration range up to 125% of the analytes nominal concentrations (100%) with regression coefficients (r) &gt; 0.99, method’s accuracy (RSD &lt; 2.0%), repeatability and intermediate precision (RSD &lt; 2.0%) were verified. System suitability parameters were also within the acceptable range. The validated method was successfully employed for the routine analysis of eye/nose drops.
Amphibian reproductive technologies: approaches and welfare considerations
Authors: Silla Aimee J , Calatayud Natalie E , Trudeau Vance L 
Published: February 2021

Abstract
Captive breeding and reintroduction programs have been established for several threatened amphibian species globally, but with varied success. This reflects our relatively poor understanding of the hormonal control of amphibian reproduction and the stimuli required to initiate and complete reproductive events. While the amphibian hypothalamo–pituitary–gonadal (HPG) axis shares fundamental similarities with both teleosts and tetrapods, there are more species differences than previously assumed. As a result, many amphibian captive breeding programs fail to reliably initiate breeding behaviour, achieve high rates of fertilization or generate large numbers of healthy, genetically diverse offspring. Reproductive technologies have the potential to overcome these challenges but should be used in concert with traditional methods that manipulate environmental conditions (including temperature, nutrition and social environment). Species-dependent methods for handling, restraint and hormone administration (including route and frequency) are discussed to ensure optimal welfare of captive breeding stock. We summarize advances in hormone therapies and discuss two case studies that illustrate some of the challenges and successes with amphibian reproductive technologies: the mountain yellow-legged frog (Rana muscosa; USA) and the northern corroboree frog (Pseudophryne pengilleyi; Australia). Further research is required to develop hormone therapies for a greater number of species to boost global conservation efforts.
Impact on actual clinical practice of the latest evidence for percutaneous closure of patent foramen ovale associated with stroke. A single center experience
Authors: Carnero Montoro L , Ruiz Ortiz M , Paredes Hurtado N , Delgado Ortega M , Rodriguez Almodovar A , Segura Saint-Gerons JM , Mazuelos Bellido F , Ochoa Sepulveda JJ , Valverde Moyano R , Romero Moreno MA , Pan Alvarez-Ossorio M , Mesa Rubio MD 
Published: February 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background and aims
Since september 14th, 2017. Three large clinical trials demonstrated that, in selected patients, percutaneous closure of patent foramen ovale (PFO) was associated with lower recurrence in patients with cryptogenic stroke (CS). Our aim was to determine the impact of these findings on routine clinical practice in a tertiary hospital.

Methods
Patients with percutaneous closure of PFO due to CS (January 2001-January 2020) were included. The clinical characteristics were analyzed individually and grouped in the RoPE score, before and after the publication date. Complex anatomy (CA) defined as interatrial septum aneurysm or basal wide bubble passage was evaluated in both periods.

Results
293 patients were included. The mean age was 49 ± 11 years, 15% were older than 60 years, 60% men, 26% hypertensive, 28% smokers and 7%diabetics. The median RoPEscore was 6 [p25-75, 5-7] and 75% met CA criteria.
Since september 14th, 2017, the frequency of CA and the mean age of the patients were significantly higher (89% vs. 69% p &lt;0.0005 and 51 ± 11 vs. 48 ± 11 years, p = 0.02, respectively), and RoPEscore, significantly lower (5 [5-7] vs. 6 [5-7], p = 0.02).

Conclusion
The publication of clinical trials wich demonstrated the benefit of percutaneous closure of PFO in CS had a significant impact on the daily clinical practice of our institution, with an increase in indications for CA, despite a clinical profile suggestive of lower causal probability of PFO.
Impaired atrial electromechanical coupling in lichen planus patients
Authors: Jafaripour I , Aryanian Z , Hosseinzadeh S , Pourkia R , Ansari Ramandi MM , Kebria Shirzadian A , Tirgar Tabari S , Pourkia M 
Published: February 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Lichen planus (LP) which is a chronic inflammatory disease can cause impaired atrial electromechanical coupling, leading to increased risk of atrial fibrillation.

Purpose
The present study aimed to evaluate atrial electromechanical coupling in LP patients by using electrocardiography (ECG) and echocardiography.

Methods
Forty-six LP patients were investigated in this cross-sectional case-control study. The control group comprised healthy individuals selected in age and gender-matched manner. Echocardiography and ECG were done for all patients to show inter and intra-atrial electromechanical delays and P wave dispersion respectively. The electromechanical delays were calculated by using the difference between the delays from the onset of the P wave on ECG to the onset of A wave on tissue Doppler recordings of the different areas.

Results
The baseline characteristics of the case and control group were similar and did not differ significantly. The P wave dispersion was 45.63 ± 3.48 milliseconds in the LP group in comparison to 36.56 ± 2.87 milliseconds in the control group (p &lt; 0.001). As shown in the table, the intra and inter-atrial electromechanical delays were also significantly prolonged in LP patients when compared to the control group (p &lt; 0.001). There was no significant difference between the left and right ventricular systolic function and diastolic function of the two groups.

Conclusion
The results of the study indicate the presence of significant impaired atrial electromechanical coupling in patients with LP confirmed by both electrocardiographic and echocardiographic tools.
Electromechanical delays Case N = 46 (mean ± SD) Control N = 46 (mean ± SD) P value Septal - PA (msec) 59.71 ± 13.24 44.39 ± 11.07 0.002 Lateral - PA (msec) 55.71 ± 13.26 48.89 ± 11.21 0.009 Tricuspid - PA (msec) 52.37 ± 13.12 43.28 ± 10.58 0.002 Inter-atrial delay (msec) (lateral PA−RV PA) 8.47 ± 1.62 6.37 ± 1.36 &lt;0.001 Intra-atrial delay (msec) (LA) [lateral PA−septal PA] 4.80 ± 1.48 3.83 ± 0.82 &lt;0.001 Intra-atrial delay (msec) (RA) [septal PA−RV PA] 3.91 ± 0.96 2.02 ± 0.71 &lt;0.001 PA Delay from the onset of the P wave on ECG to the onset of A wave on tissue Doppler, N: number, SD: Standard Deviation, LA: Left Atrium, RA: Right Atrium, RV: Right Ventricle
Tissue Doppler velocities for ruling out rejection in heart transplant recipients in the daily routine of the echocardiography laboratory: a feasibility study
Authors: Ruiz Ortiz M , Rodriguez Diego S , Delgado Ortega M , Esteban Martinez F , Rodriguez Almodovar A , Romo Penas E , Rodriguez Nieto J , Piserra Lopez-Fernandez De Heredia A , Perea Armijo J , Lopez Granados A , Lopez Aguilera J , Carrasco Avalos F , Arizon Del Prado JM , Pan Alvarez-Ossorio M , Mesa Rubio D 
Published: February 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
The sum of systolic and early diastolic myocardial velocities at lateral mitral annulus, evaluated by tissue Doppler (in absolute values, s’+e’) in the apical four chambers view is a parameter whose value for ruling out acute cellular rejection (ACR) in heart transplant (HTx) recipients has been acknowledged by the European and Brazilian recommendations for the use of imaging in HTx. A recent study has shown its independent association with ACR in the context of classical and myocardial deformation variables, with a negative predictive value (NPV) of 98% for treatment requiring ACR (TR-ACR, grade ≥ 2R) for a cut-off point of ≥23 cm/s. This work was performed under experimental conditions (only one expert echocardiographer, only one high-end equipment).

Purpose
Our objective was to study the diagnostic utility of this parameter for ruling out rejection in HTx recipients in the daily routine of the echocardiography laboratory.

Methods
From October 2017 to May 2020, serial echocardiograms were performed to 33 consecutive HTx recipients, in the 3 hours after the routine surveillance endomyocardial biopsies (EMB), in the first year after HTx. Three sonographers, seven cardiology residents and six expert echocardiographers participated in the acquisition and interpretation of the images, with seven different echocardiographic machines in only one centre. We analysed the association of s’+e’ with the presence of ACR, and the NPV of s’+e’ ≥23 cm/s for ruling out TR-ACR was investigated.

Results
A total of 176 pairs of EMB and echocardiogram were obtained. The value of s’+e’ was significantly lower with higher severity of rejection: 25.6 ± 5.5 cm/s, 23.8 ± 5.1 cm/s and 21.6 ± 3.5 cm/s for ACR grade 0R (n = 91, 52%), 1R (n = 67, 38%) and ≥2R (n = 18, 10%), respectively, p = 0.005. It was also lower when comparing studies with (≥1R) and without rejection (23.4 ± 4.9 cm/s versus 25.6 ± 5.5 cm/s, p = 0.005), or TR-ACR versus the rest of series (21.6 ± 3.5 cm/s versus 24.8 ± 5.3 cm/s, p = 0.01). The area under curve for the detection of TR-ACR was 0.67 (CI95% 0.56-0.78), p = 0.02. A cut-off point of ≥23 cm/s, present in 57% of the studies, showed a NPV of 95% for TR-ACR.

Conclusion
Lateral mitral annulus velocities showed an excellent NPV of 95% for TR-ACR detection in HTx recipients when evaluated in the daily routine of an echocardiography laboratory with a wide variety of operators and echocardiographic equipment. This finding could be useful for reducing the number of EMB in selected cases.