bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel black widow optimization approach to improve the precision in parameter estimation problem of solar photovoltaic electrical model
Authors: Chauhan Abhishek , Prakash Surya
Published: March 2022

Mathematical modeling of solar photovoltaic (PV) cell/module or array is to assess its unknown modeling parameters with the experimental current–voltage (I–V) characteristic or from the manufacturer's datasheet, where exploitation of implicit and precise solution is a stern concern among researchers for the designing of an optimized solar PV system. Hence, in this article, a robust pheromone value black widow optimization (pv‐BWO) algorithm is proposed to estimate precise modeling parameters of equivalent solar PV single‐diode model (SDM), double‐diode model (DDM), and three‐diode model (TDM). The proposed algorithm is well investigated in coordination with three case studies that hold polycrystalline and monocrystalline PV modules. The suggested technique is validated through the analysis of I–V and power–voltage (P–V) performance characteristics that are meticulously analyzed under various environmental constraints. The first two case studies are widely investigated in the literature also, whereas, to affirm the suitability of pv‐BWO under real implementation the third case study is carried out in an experimental environment. Furthermore, the pv‐BWO method for the aforesaid case studies are validated and compared with the experimental data along with various well‐established parameter estimation techniques in literature, where the proposed method promises a more reliable, stable, and precise solution for the parameter estimation problem.
Effect of double‐droplet interaction on ignition and combustion characteristics of heptane‐based nanofluid fuels in a high‐temperature environment
Authors: Zhu Baozhong , Wang Jinghui , Dai Baoxin , Sun Yunlan
Published: March 2022

The ignition and combustion characteristics of a single droplet or double droplets of the Al/n‐heptane‐based nanofluid fuels with different arrangements were investigated by a droplet‐suspension method at high temperature. The addition of ricinoleic acid and nano‐sized Al particles to n‐heptane can improve the ignition performance of n‐heptane droplets, and the ignition delay times of n‐heptane droplets are decreased by the maximum of 19.0% and 31.0%, respectively. The mixing effect of combustible vapor of adjacent droplets and the heat transfer effect of adjacent flames are responsible for the different combustion processes of nanofluid fuel droplets with different arrangements. Compared with the single droplet, the ignition delay times of the horizontal and vertical double droplets are decreased by the maximum of 26.9% and 45.7%, respectively. The vertical double droplets have better ignition performance than the horizontal double droplets due to the disturbance and mixing of the vapor flow with different directions. In addition, the droplet arrangement has different promotion effects on different droplets.
Glymphatic system dysfunction in temporal lobe epilepsy patients with hippocampal sclerosis
Authors: Lee Dong Ah , Park Bong Soo , Ko Junghae , Park Si Hyung , Lee Yoo Jin , Kim Il Hwan , Park Jin Han , Park Kang Min
Published: March 2022

Objective

This study aimed to evaluate glymphatic system function in temporal lobe epilepsy (TLE) patients with hippocampal sclerosis (HS) in comparison to healthy controls, using diffusion tensor imaging (DTI)‐analysis along the perivascular space (ALPS) method. We hypothesized that there is glymphatic system dysfunction in TLE patients with HS.

Methods

We retrospectively enrolled 25 TLE patients with HS and 26 age‐ and sex‐matched healthy controls. All participants underwent DTI with the same 3T magnetic resonance imaging scanner, and the DTI‐ALPS index was calculated. We evaluated the differences in the DTI‐ALPS index between TLE patients with HS and healthy controls. Moreover, we evaluated the correlation between the DTI‐ALPS index and clinical characteristics of epilepsy, including age, age at seizure onset, duration of epilepsy, and number of anti‐seizure medications (ASMs).

Results

There was a difference in the DTI‐ALPS index between TLE patients with HS and healthy controls. The DTI‐ALPS index in TLE patients with HS was lower than that in healthy controls (1.497 vs. 1.668, P = .015). However, there was no difference in the DTI‐ALPS index between the newly diagnosed TLE patients with HS and the chronic TLE patients with HS. The DTI‐ALPS index was negatively correlated with age (r = −0.420, P = .036). However, the DTI‐ALPS index was not correlated with other clinical characteristics, including age at seizure onset, duration of epilepsy, and number of ASMs.

Significance

Our findings showed that the DTI‐ALPS index was significantly lower in TLE patients with HS than in healthy controls, indicating the presence of glymphatic system dysfunction in TLE patients with HS. Our study also suggests that the DTI‐ALPS method may be useful for evaluating glymphatic system function in epilepsy.
ENIGMA HALFpipe: Interactive, reproducible, and efficient analysis for resting‐state and task‐based fMRI data
Authors: Waller Lea , Erk Susanne , Pozzi Elena , Toenders Yara J. , Haswell Courtney C. , Büttner Marc , Thompson Paul M. , Schmaal Lianne , Morey Rajendra A. , Walter Henrik , Veer Ilya M.
Published: March 2022

The reproducibility crisis in neuroimaging has led to an increased demand for standardized data processing workflows. Within the ENIGMA consortium, we developed HALFpipe (Harmonized Analysis of Functional MRI pipeline), an open‐source, containerized, user‐friendly tool that facilitates reproducible analysis of task‐based and resting‐state fMRI data through uniform application of preprocessing, quality assessment, single‐subject feature extraction, and group‐level statistics. It provides state‐of‐the‐art preprocessing using fMRIPrep without the requirement for input data in Brain Imaging Data Structure (BIDS) format. HALFpipe extends the functionality of fMRIPrep with additional preprocessing steps, which include spatial smoothing, grand mean scaling, temporal filtering, and confound regression. HALFpipe generates an interactive quality assessment (QA) webpage to rate the quality of key preprocessing outputs and raw data in general. HALFpipe features myriad post‐processing functions at the individual subject level, including calculation of task‐based activation, seed‐based connectivity, network‐template (or dual) regression, atlas‐based functional connectivity matrices, regional homogeneity (ReHo), and fractional amplitude of low‐frequency fluctuations (fALFF), offering support to evaluate a combinatorial number of features or preprocessing settings in one run. Finally, flexible factorial models can be defined for mixed‐effects regression analysis at the group level, including multiple comparison correction. Here, we introduce the theoretical framework in which HALFpipe was developed, and present an overview of the main functions of the pipeline. HALFpipe offers the scientific community a major advance toward addressing the reproducibility crisis in neuroimaging, providing a workflow that encompasses preprocessing, post‐processing, and QA of fMRI data, while broadening core principles of data analysis for producing reproducible results. Instructions and code can be found at https://github.com/HALFpipe/HALFpipe.
Structural connectivity of autonomic, pain, limbic, and sensory brainstem nuclei in living humans based on 7 Tesla and 3 Tesla MRI
Authors: Singh Kavita , García‐Gomar María Guadalupe , Cauzzo Simone , Staab Jeffrey P. , Indovina Iole , Bianciardi Marta
Published: March 2022

Autonomic, pain, limbic, and sensory processes are mainly governed by the central nervous system, with brainstem nuclei as relay centers for these crucial functions. Yet, the structural connectivity of brainstem nuclei in living humans remains understudied. These tiny structures are difficult to locate using conventional in vivo MRI, and ex vivo brainstem nuclei atlases lack precise and automatic transformability to in vivo images. To fill this gap, we mapped our recently developed probabilistic brainstem nuclei atlas developed in living humans to high‐spatial resolution (1.7 mm isotropic) and diffusion weighted imaging (DWI) at 7 Tesla in 20 healthy participants. To demonstrate clinical translatability, we also acquired 3 Tesla DWI with conventional resolution (2.5 mm isotropic) in the same participants. Results showed the structural connectome of 15 autonomic, pain, limbic, and sensory (including vestibular) brainstem nuclei/nuclei complex (superior/inferior colliculi, ventral tegmental area‐parabrachial pigmented, microcellular tegmental–parabigeminal, lateral/medial parabrachial, vestibular, superior olivary, superior/inferior medullary reticular formation, viscerosensory motor, raphe magnus/pallidus/obscurus, parvicellular reticular nucleus‐alpha part), derived from probabilistic tractography computation. Through graph measure analysis, we identified network hubs and demonstrated high intercommunity communication in these nuclei. We found good (r = .5) translational capability of the 7 Tesla connectome to clinical (i.e., 3 Tesla) datasets. Furthermore, we validated the structural connectome by building diagrams of autonomic/pain/limbic connectivity, vestibular connectivity, and their interactions, and by inspecting the presence of specific links based on human and animal literature. These findings offer a baseline for studies of these brainstem nuclei and their functions in health and disease, including autonomic dysfunction, chronic pain, psychiatric, and vestibular disorders.
Parameters from site classification to harmonize MRI clinical studies: Application to a multi‐site Parkinson's disease dataset
Authors: C. Monte‐Rubio Gemma , Segura Barbara , P. Strafella Antonio , van Eimeren Thilo , Ibarretxe‐Bilbao Naroa , Diez‐Cirarda Maria , Eggers Carsten , Lucas‐Jiménez Olaia , Ojeda Natalia , Peña Javier , Ruppert Marina C. , Sala‐Llonch Roser , Theis Hendrik , Uribe Carme , Junque Carme
Published: March 2022

Multi‐site MRI datasets are crucial for big data research. However, neuroimaging studies must face the batch effect. Here, we propose an approach that uses the predictive probabilities provided by Gaussian processes (GPs) to harmonize clinical‐based studies. A multi‐site dataset of 216 Parkinson's disease (PD) patients and 87 healthy subjects (HS) was used. We performed a site GP classification using MRI data. The outcomes estimated from this classification, redefined like Weighted HARMonization PArameters (WHARMPA), were used as regressors in two different clinical studies: A PD versus HS machine learning classification using GP, and a VBM comparison (FWE‐p < .05, k = 100). Same studies were also conducted using conventional Boolean site covariates, and without information about site belonging. The results from site GP classification provided high scores, balanced accuracy (BAC) was 98.39% for grey matter images. PD versus HS classification performed better when the WHARMPA were used to harmonize (BAC = 78.60%; AUC = 0.90) than when using the Boolean site information (BAC = 56.31%; AUC = 0.71) and without it (BAC = 57.22%; AUC = 0.73). The VBM analysis harmonized using WHARMPA provided larger and more statistically robust clusters in regions previously reported in PD than when the Boolean site covariates or no corrections were added to the model. In conclusion, WHARMPA might encode global site‐effects quantitatively and allow the harmonization of data. This method is user‐friendly and provides a powerful solution, without complex implementations, to clean the analyses by removing variability associated with the differences between sites.
Multi‐trajectory models of serum biomarkers among patients with monoclonal gammopathy of undetermined significance
Authors: Castañeda‐Avila Maira A. , Lapane Kate L. , Person Sharina D. , Zhou Yanhua , Gurwitz Jerry , Mazor Kathleen M. , Epstein Mara M.
Published: March 2022

Understanding the progression of monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) is needed to identify patients who would benefit from closer clinical surveillance. Given that two of the defining criteria of MM are renal failure and anemia, we described the trajectories of creatinine (Cr) and hemoglobin (Hgb) over time in patients with a diagnosis of MGUS. Patients diagnosed with MGUS (n = 424) were identified by a previously validated case‐finding algorithm using health claims and electronic health record data (2007–2015) and followed through 2018. Group‐based trajectory modeling identified patients with distinct laboratory value trajectories of Cr (mg/dl) and Hgb (g/dl). Most patients were non‐Hispanic White (97.6%) with a mean age of 75 years at MGUS diagnosis. Three multi‐trajectory groups were identified: (1) Normal Cr/Hgb (n = 225; 53.1%)—stable serum Cr levels and decreasing, normal Hgb levels; (2) Normal Cr/lower‐normal Hgb group (n = 188; 44.3%)—stable, slightly elevated levels of Cr and decreasing levels of Hgb; and (3) High Cr/borderline Hgb group (n = 11; 2.6%)—increased Cr levels and stable low levels of Hgb. Patients with MGUS in Group 2 were older than patients in other groups, and patients in group 3 had more comorbidities than participants in all other groups. Few patients developed MM during the study period. We were able to identify distinct biomarker trajectories in patients with MGUS over time. Future research should investigate how these trajectories may be related to the risk of progression to MM, including M‐protein levels.
Elevated serum IL‐13 level is associated with increased Treg cells in tumor microenvironment and disease progression of diffuse large B‐cell lymphoma
Authors: Li Xiao , Liu Mengke , Shi Qing , Fang Ying , Fu Di , Shen Zhi‐xiang , Yi Hongmei , Wang Li , Zhao Weili
Published: March 2022

Diffuse large B cell lymphoma (DLBCL) is the most common aggressive lymphoid malignancy, with an immunosuppressive microenvironment affecting clinical outcome. Interleukin (IL)‐13 overexpression is observed in multiple solid tumors and contributes to tumor progression. This study aims to investigate pretreatment serum IL‐13 levels and their relationship with the prognosis of DLBCL patients. One hundred and sixty‐six patients with newly diagnosed DLBCL from June 2015 to July 2017 were included. Patients with elevated pretreatment serum IL‐13 levels (IL‐13≥1.63 pg/ml) were classified into the high IL‐13 group and they had significantly lower complete remission rate (60% vs. 74%, p = 0.0059), higher progression rate (43% vs. 23%, p = 0.0051), and poor progression‐free survival (2‐year PFS, 63% vs. 78%, p = 0.0078) and overall survival (2‐year OS, 75% vs. 92%, p = 0.0027), when compared to those in the low IL‐13 group (IL‐13<1.63 pg/ml). Meanwhile, increased Treg cell ratio in peripheral blood (p = 0.0147) and elevated serum IL‐2 levels (p = 0.0272) were observed in the high IL‐13 group. Moreover, RNA sequencing data showed that patients in the high IL‐13 group had significantly elevated expression of chemokines and chemokine receptors (CCR4, CCL19, CCL21, CXCL2) related to Treg activation and recruitment. Consistent with the chemokine profile, tumor immunophenotyping analysis revealed that higher Treg cells recruitment in the high IL‐13 group than the low IL‐13 group (p = 0.0116). In vitro, when lymphoma cells co‐cultured with peripheral blood monocytes of healthy controls, metformin down‐regulated both IL‐13 level and Treg cell ratio, in consistent with the decreased serum IL‐13 levels of patients after 6 months of metformin maintenance therapy in the high IL‐13 group. Taken together, pretreatment serum IL‐13 level is related to the immunosuppressive microenvironment and poor clinical outcome of DLBCL patients and could be targeted by metformin, thus providing a new therapeutic strategy in treating DLBCL with high serum IL‐13 levels.
The use of spider webs in the monitoring of air quality—A review
Authors: Stojanowska Agnieszka , Zeynalli Farhad , Wróbel Magdalena , Rybak Justyna
Published: March 2022

Methods for using spider webs as passive air samplers have been developed over recent years and reported in more than a dozen articles. In this article, we present the typical procedures followed when using this new tool and critically review its application in air pollution assessment. To understand the state of research and application of spider webs in this field, we describe some advantages and disadvantages of their use in the analyses of air contaminants. The aim is to summarize the current knowledge on this subject, highlight gaps in the present studies, and arouse the interest of scientists on this issue. The increased effort could result in the standardization of the method at the national and international level. Integr Environ Assess Manag 2023;19:32–44. © 2022 SETAC
Cesarean scar ectopic pregnancies: a retrospective case series at an Australian tertiary referral center
Authors: Toh Justine , Deussen Andrea , Yasin Nooraishah , Skubisz Monika , Dodd Jodie
Published: March 2022

Objective

To review the management, success, and complication rates of women who presented with a cesarean scar ectopic pregnancy at an Australian tertiary referral center.

Methods

A retrospective case series was undertaken. Patients were identified through the hospital's clinical information services coding system and data were collected from medical records.

Results

A total of 38 cases were identified. Patients who were hemodynamically stable were predominantly managed according to local expertise via intramuscular, intra‐sac methotrexate or a combination of these two. In some cases, surgical management was preferred.

Conclusion

Cesarean scar ectopic pregnancy may be managed both surgically and medically. At institutions where surgical expertise is unavailable, medical management would be valuable with few adverse outcomes identified, provided women have closely monitored follow‐up.
Mitochondrial transport and metabolism of the vitamin B‐derived cofactors thiamine pyrophosphate, coenzyme A,FADandNAD+, and related diseases: A review
Authors: Palmieri Ferdinando , Monné Magnus , Fiermonte Giuseppe , Palmieri Luigi
Published: March 2022

Multiple mitochondrial matrix enzymes playing key roles in metabolism require cofactors for their action. Due to the high impermeability of the mitochondrial inner membrane, these cofactors need to be synthesized within the mitochondria or be imported, themselves or one of their precursors, into the organelles. Transporters belonging to the protein family of mitochondrial carriers have been identified to transport the coenzymes: thiamine pyrophosphate, coenzyme A, FAD and NAD+, which are all structurally similar to nucleotides and derived from different B‐vitamins. These mitochondrial cofactors bind more or less tightly to their enzymes and, after having been involved in a specific reaction step, are regenerated, spontaneously or by other enzymes, to return to their active form, ready for the next catalysis round. Disease‐causing mutations in the mitochondrial cofactor carrier genes compromise not only the transport reaction but also the activity of all mitochondrial enzymes using that particular cofactor and the metabolic pathways in which the cofactor‐dependent enzymes are involved. The mitochondrial transport, metabolism and diseases of the cofactors thiamine pyrophosphate, coenzyme A, FAD and NAD+are the focus of this review.
Environmental exposure of the general population to cadmium as a risk factor of the damage to the nervous system: A critical review of current data
Authors: Ruczaj Agnieszka , Brzóska Małgorzata M.
Published: March 2022

Nowadays, more and more attention has been focused on the risk of the neurotoxic action of cadmium (Cd) under environmental exposure. Due to the growing incidence of nervous system diseases, including neurodegenerative changes, and suggested involvement of Cd in their aetiopathogenesis, this review aimed to discuss critically this element neurotoxicity. Attempts have been made to recognize at which concentrations in the blood and urine Cd may increase the risk of damage to the nervous system and compare it to the risk of injury of other organs and systems. The performed overview of the available literature shows that Cd may have an unfavourable impact on the human's nervous system at the concentration >0.8 μg Cd/L in the urine and >0.6 μg Cd/L in the blood. Because such concentrations are currently noted in the general population of industrialized countries, it can be concluded that environmental exposure to this xenobiotic may create a risk of damage to the nervous system and be involved in the aetiopathogenesis of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, as well as worsening cognitive and behavioural functions. The potential mechanism of Cd neurotoxicity consists in inducing oxidative stress, disrupting the activity of enzymes essential to the proper functioning of the nervous system and destroying the homoeostasis of bioelements in the brain. Thus, further studies are necessary to recognize accurately both the risk of nervous system damage in the general population due to environmental exposure to Cd and the mechanism of this action.
Mitochondrial uncoupling attenuates sarcopenic obesity by enhancing skeletal muscle mitophagy and quality control
Authors: Dantas Wagner S. , Zunica Elizabeth R.M. , Heintz Elizabeth C. , Vandanmagsar Bolormaa , Floyd Z. Elizabeth , Yu Yongmei , Fujioka Hisashi , Hoppel Charles L. , Belmont Kathryn P. , Axelrod Christopher L. , Kirwan John P.
Published: March 2022

Background

Sarcopenic obesity is a highly prevalent disease with poor survival and ineffective medical interventions. Mitochondrial dysfunction is purported to be central in the pathogenesis of sarcopenic obesity by impairing both organelle biogenesis and quality control. We have previously identified that a mitochondrial‐targeted furazano[3,4‐b]pyrazine named BAM15 is orally available and selectively lowers respiratory coupling efficiency and protects against diet‐induced obesity in mice. Here, we tested the hypothesis that mitochondrial uncoupling simultaneously attenuates loss of muscle function and weight gain in a mouse model of sarcopenic obesity.

Methods

Eighty‐week‐old male C57BL/6J mice with obesity were randomized to 10 weeks of high fat diet (CTRL) or BAM15 (BAM15; 0.1% w/w in high fat diet) treatment. Body weight and food intake were measured weekly. Body composition, muscle function, energy expenditure, locomotor activity, and glucose tolerance were determined after treatment. Skeletal muscle was harvested and evaluated for histology, gene expression, protein signalling, and mitochondrial structure and function.

Results

BAM15 decreased body weight (54.0 ± 2.0 vs. 42.3 ± 1.3 g, P < 0.001) which was attributable to increased energy expenditure (10.1 ± 0.1 vs. 11.3 ± 0.4 kcal/day, P < 0.001). BAM15 increased muscle mass (52.7 ± 0.4 vs. 59.4 ± 1.0%, P < 0.001), strength (91.1 ± 1.3 vs. 124.9 ± 1.2 g, P < 0.0001), and locomotor activity (347.0 ± 14.4 vs. 432.7 ± 32.0 m, P < 0.001). Improvements in physical function were mediated in part by reductions in skeletal muscle inflammation (interleukin 6 and gp130, both P < 0.05), enhanced mitochondrial function, and improved endoplasmic reticulum homeostasis. Specifically, BAM15 activated mitochondrial quality control (PINK1‐ubiquitin binding and LC3II, P < 0.01), increased mitochondrial activity (citrate synthase and complex II activity, all P < 0.05), restricted endoplasmic reticulum (ER) misfolding (decreased oligomer A11 insoluble/soluble ratio, P < 0.0001) while limiting ER stress (decreased PERK signalling, P < 0.0001), apoptotic signalling (decreased cytochrome C release and Caspase‐3/9 activation, all P < 0.001), and muscle protein degradation (decreased 14‐kDa actin fragment insoluble/soluble ratio, P < 0.001).

Conclusions

Mitochondrial uncoupling by agents such as BAM15 may mitigate age‐related decline in muscle mass and function by molecular and cellular bioenergetic adaptations that confer protection against sarcopenic obesity.
COVID‐19 and the adaptive evolution of genetic counseling
Authors: Hassel Nathan C. , Gilbert Adel D. , Bejjani Bassem A.
Published: March 2022

Emerging diseases such as the Coronavirus Disease (COVID‐19) have exposed severe weaknesses in the United States and global health. Healthcare systems have struggled and are still severely challenged and strained by this pandemic. It is clear that additional resources are needed to support healthcare providers in managing this and future pandemics. Genetic counselors can play an important supporting role in this fragile ecosystem because their comprehensive and broad training makes them uniquely qualified to meet many of the challenges that arise when healthcare workers and patients are faced with novel diseases. This paper describes the recent involvement of a telegenetic counseling company (Metis Genetics) in communicating and explaining COVID‐19 serum antibody results to patients and physicians. This experience demonstrates how genetic counselors may be called upon to play a vital supporting role in the management of infectious disease pandemics. From May 2020 to July 2020, our genetic counseling telegenetics team was asked to provide support to more than 1,580 patients who underwent serum COVID‐19 antibody testing and to educate their healthcare providers on the performance properties of this new test. The genetic counselors were able to utilize their expertise to convey test results, information on Center for Disease Control and Prevention (CDC) recommendations, COVID‐19 fact‐based evidence, to provide psychological support and reassurance to patients, and to respond to providers questions about the test. This experience suggests that the genetic counselors’ skillset that has allowed the profession to continuously evolve can also be used in the management of pandemics by communicating directly with the public, supporting other healthcare workers, and assisting individual patients and families navigate the many medical and psychological issues caused by such events.
Absorption of Al(GaN)N nanorod arrays with geometrical tuning
Authors: Yu Yingzhou , Gu Yan , Lu Naiyan , Liu Guanhong , Li Sai , Niu Huan , Yang Chenjia , Zhu Chun , Wei Chunlei , Zhang Qi , Zhang Xiumei , Yang Guofeng
Published: March 2022

We theoretically demonstrate that Al(Ga)N nanorod arrays (NRAs) exhibit tunable absorption and achieve selective resonant absorption according to different Al mole factions based on COMSOL Multiphysics via the three‐dimensional finite‐element method. The optical properties of AlxGa1‐xN (x = 0, 0.2, 0.4) NRAs with different geometrical parameters were discussed from the optical absorption and electric field distribution diagram perspective. The simulated results show that the resonant wavelength of absorption spectra is red‐shifted with increase of diameter. Besides, the NRA with diameter ≤ 70 nm own lower absorptance compared to the NRA with larger diameter, which is attributed to the weak coupling between light and NRs. In terms of the influences of pitch on the optical properties, intense coupling between incident light and NRAs with smaller pitch can be obtained. Notably, the position of absorption peak is blue‐shifted as the aluminum (Al) component increases. This work is promising for photovoltaics and photodetection in ultraviolet field.
A hierarchical porous composite magnetic sorbent of reduced graphene oxide embedded in polyvinyl alcohol cryogel for solvent‐assisted‐solid phase extraction of polycyclic aromatic hydrocarbons
Authors: Rattanakunsong Natnaree , Jullakan Sirintorn , Płotka ‐ Wasylka Justyna , Bunkoed Opas
Published: March 2022

A hierarchical porouscomposite magnetic sorbent was fabricated and applied to the dispersive solvent‐assisted solid‐phase extraction of five polycyclic aromatic hydrocarbons. A sorbent was first prepared by incorporating graphene oxide, calcium carbonate, and magnetite nanoparticles into a polyvinyl alcohol cryogel. The graphene oxide was converted to reduced graphene oxide using ascorbic acid and a hierarchical porous structure was produced by reacting hydrochloric acid with incorporated calcium carbonate to generate carbon dioxide bubbles which created a second network. Before extracting the target analytes, the extraction solvent was introduced into the hierarchical pore network of the sorbent. The extraction was based on the partition between the analytes and introduced extraction solvent and the adsorption of analytes on reduced graphene oxide.The extraction efficiency was enhanced through π‐π and hydrophobic interactions between polycyclic aromatic hydrocarbons and reduced graphene oxide and extraction solvent. The extracted polycyclic aromatic hydrocarbons were determined by using high‐performance liquid chromatography coupled with a fluorescence detector. The developed method was applied to extract polycyclic aromatic hydrocarbons in disposable diaper, coffee, and tea samples and recoveries from 84.5 to 99.4% were achieved with relative standard deviations below 7%. The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.
Gain‐Associated Nonlinear Phenomenon in Single‐Conductor Odd‐Mode Plasmonic Metamaterials
Authors: Niu Ling Yun , He Pei Hang , Fan Yi , Zhang Le Peng , Zhang Hao Chi , Cui Tie Jun
Published: March 2022

Nonlinear phenomena such as second‐harmonic generation (SHG) play an important role in both optical and microwave technologies. To achieve high second‐harmonic (SH) conversion efficiency and single‐conductor system adaptability simultaneously, a gain‐associated SHG method based on odd‐mode spoof surface plasmon polaritons (SSPPs) is proposed. Field analysis indicates that the odd‐mode SSPPs can support internal electric potential difference on the cross sections of single‐conductor transmission structures to feed active semiconductor chips, which is hardly achieved by the even modes of single‐conductor structures. Measured results demonstrate the realization of SHG with a gain of 4.93 dB at 9 GHz based on the odd‐mode SSPPs, accompanied by the third‐harmonic suppression and backward SH isolation as a result of the customized passband of odd‐mode SSPPs. The ingenious detachable chip carrier can easily be disassembled, replaced and repaired, bringing big convenience and adaptability to practical applications. Moreover, the proposed single‐conductor active integration method can be extended to other single‐conductor devices, which has great potentials in the flexible systems and wearable devices.
Analysis of the Spontaneous Emission Limited Linewidth of an Integrated III–V/SiN Laser
Authors: Chow Weng W. , Wan Yating , Bowers John E. , Grillot Frédéric
Published: March 2022

This article describes a calculation of the spontaneous emission limited linewidth of a semiconductor laser consisting of hybrid or heterogeneously integrated, silicon and III–V intracavity components. Central to the approach are a) description of the multi‐element laser cavity in terms of composite laser/free‐space eigenmodes, b) use of multimode laser theory to treat mode competition and multiwave mixing, and c) incorporation of quantum‐optical contributions to account for spontaneous emission effects. Application of the model is illustrated for the case of linewidth narrowing in an InAs quantum‐dot laser coupled to a high‐ SiN cavity.
Silicon Multimode Waveguide Crossing Based on Anisotropic Subwavelength Gratings
Authors: Zhao Weike , Yi Xiaolin , Peng Yingying , Zhang Long , Chen Haitao , Dai Daoxin
Published: March 2022

Multimode waveguide crossings (MWCs) are becoming more and more important as one of the key elements for on‐chip optical routing and cross‐connection. However, it is still very challenging to achieve scalable MWCs with compact footprints, low excess losses (ELs), and low intermode cross‐talks (CTs). This work demonstrates an unprecedented silicon MWC with high performances by using the anisotropy of one‐/two‐dimensional (1D/2D) subwavelength grating (SWG) structures. For the proposed silicon MWC, the 2D‐SWG crossing region at the center has a higher refractive index than the 1D‐SWG regions at both sides for the guided‐modes of TE polarization, due to the anisotropy of the 1D/2D SWGs. As a result, the crossing region can be equivalent to a straight waveguide, and the launched TE modes can transmit through the crossing region with negligible ELs and low intermode CTs. Such an MWC can be scaled very flexibly and easily according to the new principle. The fabricated three‐mode MWC with a footprint of 14.8 × 14.8 µm2 shows ELs of <0.26 dB and intermode CTs of <−20 dB in the wavelength range of 1525–1605 nm.
Ground state solutions for a Schrödinger–Poisson–Slater‐type equation with critical growth
Authors: Zhang Jiafeng , Lei Chunyu , Lei Jun
Published: March 2022

We study the existence of ground state solutions of a Schrödinger–Poisson–Slater‐type equation with critical growth. By using the Nehari–Pohozaev manifold, we obtain the existence of ground state solutions of this system.
Opportunistic control of crescent shape MIMO design for lower sub 6 GHz 5G applications
Authors: Sree Gorre Naga Jyothi , Nelaturi Suman
Published: March 2022

For lower sub‐6 5G applications, a two‐element crescent angular ring antenna is proposed. The suggested Multiple‐Input–Multiple‐Output (MIMO) antenna has a dimension of 38 × 25 mm2, a substrate height of 1.6 mm, and dielectric material of FR‐4 (lossy) with a dielectric constant of 4.4 and a loss tangent of 0.002. For 50‐Ω impedance matching, a line feed approach is used to improve return loss and achieve −35 dB at 3.5 GHz. Furthermore, there is a fractional bandwidth from 3–6.5 GHz (116.6%) using a monopole ground plane maintained with |S11| < −10 dB. Changing the placements of the radiators improves isolation by −42 dB. For the current crescent shape, the MIMO structure showed a radiation efficiency and gain of 84.25% and 6.2 dBi. Finally, the performance of MIMO metrics of the crescent shape structure like ECC, diversity gain, channel capacity loss, TARC, and mean effective gain is evaluated in addition to good radiation characteristics.
On‐chip multiple‐coupled inductors modeling on silicon for millimeter‐wave applications
Authors: Wang Haoran , Lan Min , Xiong Yuhang , Liu Huihua
Published: March 2022

This study proposes an improved broadband equivalent circuit model for millimeter‐wave and illustrates that the real part of the Z‐parameter (like Z21, Z31, and Z41) cannot be neglected. This improved model contains multiple‐coupled inductors on silicon with effective substrate current loops. And it is fabricated and measured in four‐port and in two‐port on the basis of 0.18 μm and 40 nm CMOS technology, respectively. Moreover, this proposed model is applied to a 22–31 GHz three common‐source stages differential gm‐boost low‐noise amplifier for 5G communication in 65 nm CMOS process. According to the measurement, the minimum noise figure is 2.5 dB at 23 GHz and the maximum gain is 22.2 dB at 24.5 GHz. The chip size is 0.5 mm × 0.92 mm with all pads.
Development of PA6/GO microspheres with good processability for SLS 3D printing
Authors: Wu Bozhen , Zhu Kaiqi , Wang Fancheng , Wen Xinghan , Li Minpei , Yang Yuhao , Yang Jintao
Published: March 2022

The particle size and processability of the powder are the keys for successful nylon in selective laser sintering (SLS) 3D printing, but the nylon powders on the market have disadvantages such as uncontrollable particle size and large distribution, poor sphericity, and poor processability. In this study, graphene oxide‐hybridized polyamide 6 (PA6/GO) microspheres perfectly suitable for SLS 3D printing have been fabricated via reaction‐induced phase separation. The selective distribution of GO in PA6 microspheres was characterized by thermogravimetric (TG) and transmission electron microscopy (TEM), and the particle size and morphology of PA6/GO microspheres could be effectively controlled by adjusting the ratio of caprolactam and polystyrene. Wherein, when the polystyrene addition amount is 15 wt%, the particle size of the PA6/GO microspheres is between 40 and 50 μm, and the sintering window and thermal stability of the microspheres are significantly improved. These experimental results are surprising for the preparation of new nylon SLS 3D printing materials.
Effectively use metrics as part of process safety feedback and learning systems to monitor and improve performance
Authors: Klein James A.
Published: March 2022

Without appropriate process safety program metrics and feedback systems, warning signs of problems may be missed and learning opportunities for improving performance can be lost. Ensuring the right things are measured and evaluated, based on process safety program goals, provides information on the current performance level and trends: is performance getting better or worsening? Learning from experience, based on effective feedback systems and the use of organizational learning approaches to collect, analyze, share, and retain critical process safety information, helps promote sensitivity to operations, a sense of vulnerability, and knowledge of past problems and successes to help maintain organizational memory and maintain or improve program performance.
A scoring framework for tiered warnings and multicategorical forecasts based on fixed risk measures
Authors: Taggart Robert , Loveday Nicholas , Griffiths Deryn
Published: March 2022

The use of tiered warnings and multicategorical forecasts are ubiquitous in meteorological operations. Here, a flexible family of scoring functions is presented for evaluating the performance of ordered multicategorical forecasts. Each score has a risk parameter , selected for the specific use case, so that it is consistent with a forecast directive based on the fixed threshold probability (equivalently, a fixed ‐quantile mapping). Each score also has use‐case specific weights so that forecasters who accurately discriminate between categorical thresholds are rewarded in proportion to the weight for that threshold. A variation is presented where the penalty assigned to near misses or close false alarms is discounted, which again is consistent with directives based on fixed risk measures. The scores presented provide an alternative to many performance measures currently in use, whose optimal threshold probabilities for forecasting an event typically vary with each forecast case, and in the case of equitable scores are based around sample base rates rather than risk measures suitable for users.
Oxidation of Cyclopentene with Manganese Oxides Octahedral Molecular Sieves with Layer and Tunnel Structures
Authors: Garces Luis J. , Galeano John Alexander , Garces Hector F. , Suib Steven L. , Hincapie Beatriz
Published: March 2022

Manganese oxides type octahedral molecular sieves OL‐1, OMS‐1, and OMS‐2 were synthesized, impregnated with sodium tungstate, and evaluated as catalysts for the selective epoxidation of cyclopentene (CPE) to cyclopentene oxide (CPO) in the sodium bicarbonate/hydrogen peroxide (BAP) system. OL‐1 was the best catalyst with a conversion of 78.6 % and a selectivity to CPO of 31.4 %. Impregnation with sodium tungstate affected the structure and activity of OL‐1 and OMS‐1. Mn2+ is required for the epoxidation of CPE. FTIR spectra provides evidence that tungstate ions react, during impregnation, with Mg2+ and/or Mn2+ present in OMS‐1 and OL‐1 producing an amorphous compound that is not active in the epoxidation reaction. The crystalline and chemical structure of OMS‐2 was not affected by tungstate impregnation, since most of the manganese occurs as Mn3+ and Mn4+, which in presence of hydrogen peroxide, tend to form radicals, active in the total oxidation of organic compounds.
A Sensitive Electrochemical Sensor Based on Co3O4‐CeO2 Composites Modified Glassy Carbon Electrode for the Determination of Bisphenol A
Authors: Yang Qin , Chen Ninghua , Zhang Xuefeng , Ye Zhixiang , Yang Yingchun
Published: March 2022

A novel electrochemical bisphenol A (BPA) sensor based on Co3O4‐CeO2 composites modified glassy carbon electrode (Co3O4‐CeO2/GCE) was prepared in this study. Co3O4‐CeO2 composites were easily prepared by sol‐gel combustion method, and their morphology and structure were characterized by scanning electron microscope (SEM), X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The electrochemical behavior of BPA on the modified electrode was investigated by cyclic voltammetry (CV), and an irreversible oxidation peak appeared at 0.598 V (pH=6). Also the effects of scan rate and pH on electron transfer efficiency of electrode were investigated by CV method. In order to reduce background interference and improve sensitivity, the limit of detection (LOD) and BPA of samples were detected by differential pulse voltammetry (DPV). The results showed there is a wide linear range of 0.033 μM∼30.3 μM with LOD of 0.0048 μM (S/N=3) for the constructed electrochemical sensor. It was successful used for the determination of BPA in real samples with satisfied results (the recoveries were between 99.2 % and 101.2 %). The fabricated Co3O4‐CeO2/GCE‐based sensors exhibited excellent electrochemical performance of BPA, so it could provide an alternative platform for the determination of BPA in the environment.
A Natural Hydrogel with Prohealing Properties Enhances Tendon Regeneration
Authors: Dang Ruyi , Chen Liling , Sefat Farshid , Li Xian , Liu Shilin , Yuan Xulei , Ning Xiaoqiao , Zhang Yu Shrike , Ji Ping , Zhang Ximu
Published: March 2022

Tendon regeneration and reduction of peritendinous adhesion remain major clinical challenges. This study addresses these challenges by adopting a unique hydrogel derived from the skin secretion of Andrias davidianus (SSAD) and taking advantage of its biological effects, adhesiveness, and controllable microstructures. The SSAD‐derived hydrogel contains many cytokines, which could promote tendon healing. In vitro, leach liquid of SSAD powder could promote tendon stem/progenitor cells migration. In vivo, the SSAD‐derived hydrogel featuring double layers possesses strong adhesiveness and could reconnect ruptured Achilles tendons of Sprague‐Dawley rats without suturing. The intimal SSAD‐derived hydrogel, with a pore size of 241.7 ± 21.0 µm, forms the first layer of the hydrogel to promote tendon healing, and the outer layer SSAD‐derived hydrogel, with a pore size of 3.3 ± 1.4 µm, reducing peritendinous adhesion by serving as a dense barrier. Additionally, the SSAD‐derived hydrogel exhibits antioxidant and antibacterial characteristics, which further contribute to the reduction of peritendinous adhesion. In vivo studies suggest that the SSAD‐derived hydrogel reduces peritendinous adhesion, increases collagen fiber deposition, promotes cell proliferation, and improves the biomechanical properties of the regenerated tendons, indicating better functional restoration. The SSAD‐derived bilayer hydrogel may be a feasible biomaterial for tendon repair in the future.
The Effects of Temperature on Starch Molecular Conformation and Hydrogen Bonding
Authors: Zhiguang Chen , Junrong Huang , Huayin Pu , Keipper Wade
Published: March 2022

Starch is an important resource in nature and heating is a frequently used processing method. In the process of starch processing, the changes of starch molecular conformation play a decisive role on starch physicochemical properties. Meanwhile, hydrogen bond is an important interaction force for maintaining starch structure. Therefore, molecular dynamics simulation is used to explore the effects of temperature on starch molecular conformation and hydrogen bonds. The results show that, firstly, heating can unwind the double‐amylose helix and improve the bending degree of starch molecules, indicating that heating treatment is destructive to the crystalline region. Secondly, starch molecules will become more unstable with the increase of temperature, which may be the key factor of heating induced starch gelatinization starch. Thirdly, heating will increase the intramolecular hydrogen bonds and decrease the starch‐water hydrogen bonds. Meanwhile, the hydrogen bond distributions in starch molecules are also clarified. The results can be complementary to the existing experimental phenomena about the effects of temperature on starch properties, and provide a reference for the fully explanation of the effects mechanism of heating on starch. Meanwhile, the results can also provide a reference for the using of heating in starch processing and the research of starch granule structure.
A limit state design approach for hybrid reinforced concrete column‐supported flat slabs
Authors: Aidarov Stanislav , Tošić Nikola , de la Fuente Albert
Published: March 2022

Hybrid reinforced technology (combination of steel reinforcing bars and fibers) can be considered as a competitive alternative to the already existing solutions for the construction of column‐supported flat slabs. Constructed hybrid‐reinforced buildings prove that hybrid solutions have sufficient bearing capacity to maintain structural integrity despite being exposed to high stress levels, thereby providing a beneficial solution in terms of toughness, ductility, and sustainability performance. However, the lack of design‐oriented recommendations based on the accepted limit state format for dealing with both serviceability and ultimate limit states slows down the wider implementation of this technology. Considering the above‐mentioned, this article presents a simplified design‐oriented method that covers the evaluation of the structural response of hybrid reinforced concrete column‐supported flat slabs in terms of flexural strength, cracking, and instantaneous deformations. Two hybrid reinforced alternatives for a given flat slab are studied by means of the proposed approach. Furthermore, a nonlinear finite element analysis is carried out in order to evaluate the effectiveness of the developed simplified method. Based on the achieved results, its suitable accuracy and precision can be pointed out. This outcome may motivate current practitioners to consider hybrid reinforced concrete solutions as a possible alternative during the design of residential and office buildings.
Leading instructional improvement in elementary science: State science coordinators' sense‐making about the Next Generation Science Standards
Authors: Haverly Christa , Lyle Angela , Spillane James P. , Davis Elizabeth A. , Peurach Donald J.
Published: March 2022

The Next Generation Science Standards (NGSS), a reform effort “for states, by states,” advances ambitious ideals for elementary science teaching, but the fate of these ideals will depend in part on the engagement of state science coordinators (SSCs). This article explores the responses ofSSCstoNGSSin a purposeful sample of 18USstates. Based on analysis of 19 interviews with 22SSCs, we develop two arguments. First,SSCs' ideas about improving elementary science education converged around three themes: the introduction of three‐dimensional science teaching and learning, the integration of engineering with science teaching, and the integration of science withELAand mathematics. Second,SSCs' sense‐making about reforming elementary science education was situated in and shaped by (a) their knowledge of how elementary science instruction has been and continues to be de‐prioritized, as well as their experiences (b) facilitating work groups in developing science standards using theFramework for K‐12 Science Education, and (c) participating in professional networks.