bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of performance and emission in a lean‐burn gas fueled spark ignition engine by using a new pre‐chamber
Authors: Kheyrollahi Javad , Jafarmadar Samad , Khalilarya Shahram , Amini Niaki Seyed Reza 
Published: March 2021

AbstractLean burn combustion of natural gas in spark‐ignited engines is a promising approach to improving engine performance and efficiency by reducing pollutant emissions and better fuel consumption. However, inducing excessive lean mixture to the engine makes the combustion unstable, and misfire happens in a significant number of cycles. The pre‐chamber ignition technology is a useful solution that can make spark‐ignition engines more efficient. In this study, the lean mixture's combustion was empirically investigated with a new pre‐chamber spark plug in a one‐cylinder engine fueled with natural gas. Tests were performed at 11.5, 13.5, and 16 compression ratios and a wide range of air‐fuel ratios. With the pre‐chamber spark plug usage, the lean operating limit is enlarged by 10%–45% and gives 4% and 3% the average lower in‐cylinder pressure and exhaust gas temperature than the conventional spark ignition system. The brake‐specific fuel consumption was improved by 4%–11% using the pre‐chamber spark ignition. The HC, CO, and NOx formation is about 11%, 16.3%, and 10% lower than the conventional spark ignition usage. Outcomes confirmed that the new design pre‐chamber plug gives 1% improved COVIMEP than the standard spark plug. The use of pre‐chamber due to the lean‐burn combustion causes larger ignition delay and increases brake thermal efficiency by up to 9%. It can be concluded that the pre‐chamber increases the ignition ability, and the lean mixture limit is extended.
Improved decolorization of dye wastewater and enhanced power output in the electrically stacked microbial fuel cells with H2O2 modified corncob anodes
Authors: Sonu Kumar , Sogani Monika , Syed Zainab , Dongre Aman , Sharma Gopesh 
Published: March 2021

AbstractThe key operational constraints of the microbial fuel cell (MFC) technology in achieving its due potential are the high cost of electrodes and the difficulties in scaling up. To address these issues, carbonized corncob anodes were prepared and modified with the hydrogen peroxide (H2O2) to increase the oxygenated functional groups favoring the extracellular electron transfer between the microbes and electrodes. Compared to the MFC with anode without any modification, that is, bare anode, the single chambered MFC with 20% H2O2 modified anode exhibited excellent electro‐catalytic activity and a 91% decrease in the internal resistance (decreased from 35 ± 0.5 to 3.0 ± 0.6 kΩ) along with 89% increase in the maximum power density (increased from 8.8 ± 0.7 to 89.7 ± 0.6 mW/m2). MFCs with 20% H2O2 modified anode resulted in high decolorization efficiency of real dye wastewater (RDW) up to 92% which is 18% higher than that of the MFC with the bare anode. In order to boost the power output, the system was designed and studied by electrically stacking the 24 individual units of the MFC with the modified anode into parallel and series configurations. In parallel stacking and series stacking, the power output was 18.9 and 13.5 times higher than the single MFC unit, respectively. The RDW degradation rate was in the order of parallel stack > series stack > single MFC unit.
Silver nanoparticle filter for domestic wastewater reuse
Authors: Gagneten Ana M , Romero Natalí , Reno Ulises , Regaldo Luciana , Kergaravat Silvina V , Rodenak‐Kladniew Boris E , Castro Guillermo R 
Published: March 2021

AbstractBACKGROUNDUnder scarcity of freshwater, the reuse and low‐cost technological solutions applied to wastewaters seek to reduce contamination to the users and freshwater biota.RESULTSA low‐cost cellulose membrane was doped with silver nanoparticles to filter urban wastewater (UW) from a city in Argentina. The total amount of coliforms and Escherichia coli in the filter decreased by 99.6% and 99.9%, respectively. The leak of silver from the filter was 275 ng L−1, analyzed by square wave anodic stripping voltammetry. Silver nanoparticles tested on HepG2 and A549 mammalian cell lines showed no toxicity in a broad concentration range. Calculation of the organic matter provided by dead bacteria post‐filtration was 347 μg L−1 proteins, 148 μg L−1 nucleic acids, 57 μg L−1 lipids, and 53 μg L−1 polysaccharides, indicating high availability of organic matter. The retention of inorganic salts in the filter was 78.5% ammonia, 6.2% nitrates, 97.6% nitrites, and 19.2% phosphates. In post‐filtered UW, the Lactuca sativa germination test showed early seed germination between 90% and 95% in all the dilutions tested. In the range of 6.25% to 50.0%, filtered UW showed no significant differences in the hypocotyl but the difference was significant in the radicle length (mm) compared to the control made of synthetic media (P < 0.05).CONCLUSIONThe development of a low‐cost filter based on cellulose membranes doped with silver nanoparticles allowed the reuse of wastewater for domestic purposes and garden irrigation. © 2021 Society of Chemical Industry (SCI).
Preparation and characterization of leukocyte‐ and platelet‐rich fibrin membrane derived from cats' blood
Authors: Castilho Maíra Sales , Rahal Sheila Canevese , Dias Neto Ramiro das Neves , Pereira Ana Cristina , Francia Camila Contin Diniz de Almeida , Mesquita Luciane dos Reis , Antunes Carina Bueno , Lainetti Patrícia de Faria , Fonseca‐Alves Carlos Eduardo 
Published: March 2021

AbstractAutologous platelet concentrates have been used in regenerative medicine in humans due to the abundance of growth factors, but there are only a few reports in small animals. This study aimed to prepare and characterize a leukocyte and platelet‐rich fibrin membrane (L‐PRF) produced with blood obtained from cats. Thirteen client‐owned healthy adult Maine Coon cats were enrolled. The blood samples were collected and centrifuged at 650g for 12 min using a centrifuge specifically designed for this application. The L‐PRF clot was removed from the tube and red blood cell base layer was separated, leaving buffy coat intact. After this, L‐PRF clot was compressed by specialized metal plate for 30–60 s, and L‐PRF membrane was obtained. Light microscopy examination of the membranes showed three distinct layers: white part, buffy coat, and red part. Immunohistochemical analysis demonstrated expression of vascular endothelial growth factor and platelet derived growth factor. The scanning electron microscopy showed that three‐dimensional architecture of fibrin network was more compact in the area near the buffy coat. In conclusion, the method used allowed the characterization of the L‐PRF membrane composition, which presented cell types and fibrin network architecture similar to those described in the human species.
Sensitivity of Myocardial Radiomic Features to Imaging Parameters in Cardiac MR Imaging
Authors: Jang Jihye , El‐Rewaidy Hossam , Ngo Long H. , Mancio Jennifer , Csecs Ibolya , Rodriguez Jennifer , Pierce Patrick , Goddu Beth , Neisius Ulf , Manning Warren , Nezafat Reza 
Published: March 2021

BackgroundCardiac magnetic resonance (MR) images are often collected with different imaging parameters, which may impact the calculated values of myocardial radiomic features.PurposeTo investigate the sensitivity of myocardial radiomic features to changes in imaging parameters in cardiac MR images.Study TypeProspective.PopulationA total of 11 healthy participants/five patients.Field Strength/ SequenceA 3 T/cine balanced steady‐state free‐precession, T1‐weighted spoiled gradient‐echo, T2‐weighted turbo spin‐echo, and quantitative T1 and T2 mapping. For each sequence, the flip angle, in‐plane resolution, slice thickness, and parallel imaging technique were varied to study the sensitivity of radiomic features to alterations in imaging parameters.AssessmentMyocardial contours were manually delineated by experienced readers, and a total of 1023 radiomic features were extracted using PyRadiomics with 11 image filters and six feature families.Statistical TestsSensitivity was defined as the standardized mean difference (D effect size), and the robust features were defined at sensitivity < 0.2. Sensitivity analysis was performed on predefined sets of reproducible features. The analysis was performed using the entire cohort of 16 subejcts.Results64% of radiomic features were robust (sensitivity < 0.2) to changes in any imaging parameter. In qualitative sequences, radiomic features were most sensitive to changes in in‐plane spatial resolution (spatial resolution: 0.6 vs. flip angle: 0.19, parallel imaging: 0.18, slice thickness: 0.07; P < 0.01 for all); in quantitative sequences, radiomic features were least sensitive to changes in spatial resolution (spatial resolution: 0.07 vs. slice thickness: 0.16, flip angle: 0.24; P < 0.01 for all). In an individual feature level, no singular feature family/image filter was identified as robust (sensitivity < 0.2) across sequences; however, highly sensitive features were predominantly associated with high‐frequency wavelet filters across all sequences (32/50 features).Data ConclusionIn cardiac MR, a considerable number of radiomic features are sensitive to changes in sequence parameters.Evidence Level1Technical EfficacyStage 1
Antimicrobial susceptibility and virulence of Enterococcus spp. isolated from periodontitis‐associated subgingival biofilm
Authors: Espíndola Laís Christina P. , do Nascimento Marcus Vinícius M. R. , do Souto Renata M. , Colombo Ana Paula V. 
Published: March 2021

AbstractBackgroundThis study evaluated the prevalence, virulence and antimicrobial susceptibility of enterococci isolated from the subgingival microbiota of patients with different periodontal status.MethodsSubgingival biofilm was obtained from individuals with periodontal health (PH) (n = 139), gingivitis (n = 103), and periodontitis (n = 305) and cultivated on selective media. Isolated strains were identified by mass spectrometry. Antimicrobial sensitivity was determined by disk diffusion, virulence genes by polymerase chain reaction, and the subgingival microbiota by checkerboard. Differences among groups were assessed by Kruskal‒Wallis, Mann‒Whitney, and Chi‐square tests.ResultsEnterococcus spp. were isolated from 7.4% of all samples; 53.7% were Enterococcus faecalis. They were more prevalent in periodontitis (9.8%) and gingivitis (7.8%) than PH (2.2%; P <0.05), but no differences among stages of disease severity were observed. High rates of low susceptibility/resistance (>64%) to at least one antimicrobial were observed. Predominant virulence factors included ace (64.3%), asa (39.3%), and esp (35.7%). Fusobacterium nucleatum was prevalent in the subgingival microbiota of enterococci+ individuals, whereas Dialister pneumosintes was found in low frequency in patients with bopD+ enterococci. Oral streptococci were prevalent (>70%) in patients carrying enterococci susceptible to doxycycline (P <0.05), usually bopD‐ and esp‐ (P <0.01).ConclusionsE. faecalis is increased in periodontitis‐associated biofilm. Oral enterococci carry virulence genes and express resistance to some antibiotics commonly used in dentistry, such as ciprofloxacin and erythromycin. Specific subgingival taxa are associated with oral enterococci, suggesting they may interact with species of the dysbiotic periodontitis biofilm, constituting a potential source of factors to tissue destruction, antibiotic resistance dissemination, and poor response to periodontal therapy.
Lactulose significantly increased the relative abundance of Bifidobacterium and Blautia in mice feces as revealed by 16S rRNA amplicon sequencing
Authors: Cui Shumao , Gu Jiayu , Liu Xuemei , Li Dongyao , Mao Bingyong , Zhang Hao , Zhao Jianxin , Chen Wei 
Published: March 2021

AbstractBACKGROUNDLactulose was one of the earliest prebiotics to be identified. To assess the potential risk of large intakes of lactulose to the intestinal microbiota, mice were fed a diet containing lactulose (0%, 5% and 15%, w/w) for 2 weeks and the changes in the fecal microbiota were evaluated by 16S rRNA high‐throughput sequencing.RESULTSLactulose intervention decreased the α‐diversity of the fecal microbiota in both low‐dose and high‐dose groups. The relative abundance of Actinobacteria was significantly increased, while that of Bacteroidetes was significantly decreased after lactulose intervention. At the genus level, the relative abundance of Bifidobacterium belonging to Actinobacteria was significantly increased, and that of Alistipes belonging to Bacteroidetes was decreased in both low‐dose and high‐dose groups. The relative abundance of Blautia was significantly increased from 0.2% to 7.9% in the high‐dose group and one strain of Blautia producta was isolated from the mice feces. However, the strain could not utilize lactulose.CONCLUSIONOverall, the microbial diversity was decreased after lactulose treatment, with significant increases in the relative abundance of Bifidobacterium. We also provide a strategy to increase the relative abundance of Blautia in the intestine by lactulose feeding at high doses, although the mechanism is not revealed. This will help us understand the prebiotic effect of lactulose on the host health. © 2021 Society of Chemical Industry.
A chemometrics approach comparing characteristics and free radical scavenging capacity of flax (Linum usitatissimum L.) oils obtained from seeds and cakes with different extraction methods
Authors: Zhang Youfeng , Zhou Yang , Song Zhihua , Jin Jun , Tang Junjun , Wang Xingguo , Huang Jianhua , Jin Qingzhe 
Published: March 2021

AbstractBACKGROUNDFlax oil, a nutritive vegetable oil, is a rich natural source of the essential C18:3 α‐linolenic acid and trace nutrients (tocopherol, phytosterol, polyphenol, flavonoid, etc.). In most small‐ and medium‐sized facilities, the oil content in pressed cake is as high as 10%, which is not fully extracted and utilized. These cannot be neglected since they account for a considerable proportion. Characteristics and free radical scavenging capacity of flax (Linum usitatissimum L.) oil obtained from seeds and cakes with different extraction methods – cold‐pressing, hot‐pressing (120 and 160 °C) and solvent extraction (oil extracted with solvent from flaxseed, cold‐pressed cake, and hot‐pressed cake) – were evaluated and analyzed using chemometrics methods.RESULTSThe composition of C18:3 α‐linolenic acid of flax oil was not affected by the extraction methods in this work. Flax oils extracted with solvent from pressed cakes had lower content of bioactive minor components (tocopherols and phytosterols) compared with pressed and solvent‐extracted seed oils. The former also showed poorer oxidative stability and free radical scavenging capacity (polar fraction) when compared with the latter. Flax oils could be distinguished with principal component analysis and hierarchical cluster analysis. Tocopherols and phytosterols exhibited significant contributions to the antioxidant capacity of flax oils via correlation analysis and multiple linear regression analysis.CONCLUSIONTocopherols and phytosterols were appropriate and potent indicators for evaluating the antioxidant capacity of flax oil. Results have important implications for the industrial production and nutritional value of flax oil, especially for flax oils from the cakes after pressing. © 2021 Society of Chemical Industry.
Associations Among Increases in Posttraumatic Stress Symptoms, Neurocognitive Performance, and Long‐Term Functional Outcomes in U.S. Iraq War Veterans
Authors: Jackson Colleen E. , Ciarleglio Maria M. , Aslan Mihaela , Marx Brian P. , Ko John , Concato John , Proctor Susan P. , Vasterling Jennifer J. 
Published: March 2021

AbstractCross‐sectional research suggests that posttraumatic stress symptoms (PTSS) among war zone veterans are associated with functional impairment and poor quality of life. Less is known about the long‐term functional repercussions of PTSS. This study of Iraq War veterans examined the associations between increases in PTSS and long‐term functional outcomes, including the potential contributions of neurocognitive decrements. Service members and veterans (N= 594) completed self‐report measures of functioning and PTSS severity before Iraq War deployment and again after their return (M= 9.3 years postdeployment). Some participants (n= 278) also completed neurocognitive testing at both times. Multiple regression analyses with the full sample—adjusted for TBI, demographic characteristics, military variables, and predeployment PTSS and functioning—revealed that increased PTSS severity over time was significantly associated with unemployment, aOR= 1.04, 95% CI [1.03, 1.06]; poorer work performance; and poorer physical, emotional, and cognitive health–related functioning at long‐term follow‐up,f2s = 0.37–1.79. Among participants who completed neurocognitive testing, a decline in select neurocognitive measures was associated with poorer functioning; however, neurocognitive decrements did not account for associations between increased PTSS and unemployment, aOR= 1.04, 95% CI [1.02, 1.07], with the size and direction upheld after adding neurocognitive variables, or poorer functional outcomes, with small increases after adding neurocognitive measures to the models,f2s = 0.03–0.10. War zone veterans experiencing long‐term increased PTSS and/or neurocognitive decrements may be at elevated risk for higher‐level functional impairment over time, suggesting that early PTSS management may enhance long‐term functioning.
A Network Analysis of DSM‐5 Posttraumatic Stress Disorder Symptoms and Event Centrality
Authors: Guineau Melissa. G. , Jones Payton. J. , Bellet Benjamin. W. , McNally Richard. J. 
Published: March 2021

AbstractThe centrality of a traumatic event to one's autobiographical memory has been associated with posttraumatic stress disorder (PTSD) symptom severity. In the present study, we investigated the associations between specific features of event centrality (EC), as measured using the Centrality of Event Scale, and specific symptoms of PTSD. We computed a cross‐sectional graphical lasso network of PTSD symptoms and specific features of EC in a sample of trauma‐exposed individuals (n = 451), many of whom met the clinical threshold for a PTSD diagnosis. The graphical lasso revealed intrusive memories, negative trauma‐related feelings, and the perception that the traumatic event was central to one's identity to be influential nodes. Viewing the future through the lens of one's trauma exposure was the EC feature most strongly linked to PTSD. Among all PTSD symptoms, blaming oneself or others for the traumatic event showed the strongest link to EC. The network was stable, allowing for reliable interpretations. Future longitudinal research is needed to clarify the associations among EC features and PTSD symptoms over time.
Broadband high‐efficiency power amplifier with compact coupling matching network
Authors: Wang Weirong , Liu Guohua , Zhang Zhiwei , Cheng Zhiqun 
Published: March 2021

AbstractThis article presents the design of a broadband high‐efficiency power amplifier (PA) with a compact coupling structure. In theory, the output matching network impedance expression based on the compact coupling structure is derived. According to the load impedance range of the class EFJ PA, the coupling structure is deduced to meet the impedance range of the class EFJ PA. This structure can realize the two functions of impedance transformation and harmonic impedance control. In order to further expand the bandwidth and improve the drain efficiency, the step impedance matching method is used to design the input matching network. To verify this design approach, a broadband high‐efficiency PA over a 115% bandwidth from 0.8 to 3.0 GHz is designed. The measured results show that the PA delivers output power of 40–42.2 dBm with the drain efficiency of 62%–73% and gain of 10–12.2 dB in the target band. The test results are good consistent with the simulated ones.
An end‐to‐end‐trainable iterative network architecture for accelerated radial multi‐coil 2D cine MR image reconstruction
Authors: Kofler Andreas , Haltmeier Markus , Schaeffter Tobias , Kolbitsch Christoph 
Published: March 2021

PurposeIterative convolutional neural networks (CNNs) which resemble unrolled learned iterative schemes have shown to consistently deliver state‐of‐the‐art results for image reconstruction problems across different imaging modalities. However, because these methods include the forward model in the architecture, their applicability is often restricted to either relatively small reconstruction problems or to problems with operators which are computationally cheap to compute. As a consequence, they have not been applied to dynamic non‐Cartesian multi‐coil reconstruction problems so far.MethodsIn this work, we propose a CNN architecture for image reconstruction of accelerated 2D radial cine MRI with multiple receiver coils. The network is based on a computationally light CNN component and a subsequent conjugate gradient (CG) method which can be jointly trained end‐to‐end using an efficient training strategy. We investigate the proposed training strategy and compare our method with other well‐known reconstruction techniques with learned and non‐learned regularization methods.ResultsOur proposed method outperforms all other methods based on non‐learned regularization. Further, it performs similar or better than a CNN‐based method employing a 3D U‐Net and a method using adaptive dictionary learning. In addition, we empirically demonstrate that even by training the network with only iteration, it is possible to increase the length of the network at test time and further improve the results.ConclusionsEnd‐to‐end training allows to highly reduce the number of trainable parameters of and stabilize the reconstruction network. Further, because it is possible to change the length of the network at the test time, the need to find a compromise between the complexity of the CNN‐block and the number of iterations in each CG‐block becomes irrelevant.
Better nurse work environments associated with fewer readmissions and shorter length of stay among adults with ischemic stroke: A cross‐sectional analysis of United States hospitals
Authors: Brom Heather , Brooks Carthon J. Margo , Sloane Douglas , McHugh Mathew , Aiken Linda 
Published: March 2021

AbstractStroke is among the most common reasons for disability and death. Avoiding readmissions and long lengths of stay among ischemic stroke patients has benefits for patients and health care systems alike. Although reduced readmission rates among a variety of medical patients have been associated with better nurse work environments, it is unknown how the work environment might influence readmissions and length of stay for ischemic stroke patients. Using linked data sources, we conducted a cross‐sectional analysis of 543 hospitals to evaluate the association between the nurse work environment and readmissions and length of stay for 175,467 hospitalized adult ischemic stroke patients. We utilized logistic regression models for readmission to estimate odds ratios (OR) and zero‐truncated negative binomial models for length of stay to estimate the incident‐rate ratio (IRR). Final models accounted for hospital and patient characteristics. Seven and 30‐day readmission rates were 3.9% and 10.1% respectively and the average length of stay was 4.9 days. In hospitals with better nurse work environments ischemic stroke patients experienced lower odds of 7‐ and 30‐day readmission (7‐day OR, 0.96; 95% confidence interval [CI]: 0.93–0.99 and 30‐day OR, 0.97; 95% CI: 0.94–0.99) and lower length of stay (IRR, 0.97; 95% CI: 0.95–0.99). The work environment is a modifiable feature of hospitals that should be considered when providing comprehensive stroke care and improving post‐stroke outcomes.