bluuebunny/crossref_metadata_2025 huggingface dataset:
Indirect Nuclear Spin‐Spin Exchange Coupling through Solvated Electron in Small Sizes of Cyclic and Cage‐Shaped Perfluoroalkanes
Authors: Chen Xiao , Bu Yuxiang
Published: March 2023

Small perfluorocycloalkanes (hexafluorocyclopropane (c‐C3F6), octafluorocyclobutane (c‐C4F8) and decafluorocyclopentane (c‐C5F10) and cage‐shaped perfluoroalkanes (perfluoro tetrahedral alkane (C4F4), perfluoro prismane (C6F6) and perfluoro cubane (C8F8)) are better electron scavengers. The captured excess electrons are weakly bound inside their backbone voids or over their backbones, forming the solvated electron (
) systems (e@c‐CnF2ns (n=3, 4, 5) and e@CnFn (n=4, 6, 8)). There have been many studies on the structures and properties of such
systems. However, the effect of
on the indirect nuclear spin‐spin coupling (J‐coupling) is unknown. In this work, we explore how
affects NeJ‐coupling between two coupled F nuclei (NeJFF‐coupling) in perfluoroalkane
systems through density functional theory calculations. We find unusual trans‐NeJFF‐couplings (two coupled F nuclei in trans‐position) in e@c‐CnF2n (n=3, 4, 5) and NeJFF‐couplings in e@CnFn (n=4, 6, 8). One excess electron not only changes the molecular structures, but also enforces unique distributions and properties, depending on the structural characteristics. We also confirm that such unusual NeJFF‐couplings are realized by through‐
(T‐SE) transmission mechanism, rather than the conventional through‐bonds (T−B)/through‐space (T−S) ones. The novel transmission mechanism consists of the T‐SE coupling path (path 1) and
‐enhanced T−B
T−S coupling path (path 2), and the two paths jointly control NeJFF through cooperation and competition. Interestingly, the former plays a dominant role for long‐range NeJFF‐coupling (N=5), while the latter plays a role in the short‐range NeJFF‐coupling (N=3, 4). Path bending angle mainly influences path 1, while path 2 is mainly influenced by the path length. This work not only provides novel insights into the mediating role of
in the coupling information exchange, but also proposes a new
‐based coupling mechanism, possibly opening up potential applications for the
‐based indirect nuclear spin couplings.
Influence of the Thiophene Ring on the Molecular Order of Structurally Simple π‐Conjugated Smectogens: 13C NMR Study
Authors: Veeraprakash Bathini , Pratap Gallelli , Lobo Nitin P. , Ramanathan Krishna V. , Narasimhaswamy Tanneru
Published: March 2023

Structurally simple rod‐like π‐conjugated mesogens with thiophene directly connected to phenyl, biphenyl, and fluorenone rings with terminal chains are synthesized respectively. The occurrence of smectic A/smectic C phases is concurred by a hot‐stage optical polarising microscope (HOPM), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). The static 1D and 2D 13C nuclear magnetic resonance (NMR) studies in the liquid crystalline phase are carried out to find the alignment‐induced chemical shifts (AIS) and 13C−1H dipolar couplings. The orientational order parameters of the mesogens determined from 13C−1H dipolar couplings disclose that the long axis is not only collinear to the C3−C4 bond of the thiophene ring but also for the local axes of phenyl and biphenyl rings. For fluorenone‐based mesogen, the molecular biaxiality is found to be high owing to the increased breadth of the molecule. The study unveils that the orientation of thiophene and the phenyl rings is similar in the current mesogens in stark contrast to mesogens, where thiophene is connected to phenyl rings through linking groups.
Intrinsically Chiral Twist‐Bend Nematogens: Interplay of Molecular and Structural Chirality in the NTB Phase
Authors: Walker Rebecca , Pociecha Damian , Salamonczyk Miroslaw , Storey John M. D. , Gorecka Ewa , Imrie Corrie T.
Published: March 2023

The front cover artwork is provided by Dr Rebecca Walker of the Liquid Crystals Group at the University of Aberdeen. The image is a cartoon depiction of the formation of the heliconical chiral twist‐bend nematic phase (N*TB) from its constituent bent molecules. The presence of a single enantiomer of the chiral, lactate‐based liquid crystal dimers biases the formation of helices with only one handedness, unlike in the conventional NTB phase, observed for achiral molecules, for which the left‐ and right‐handed helices are doubly degenerate. Read the full text of the Research Article at 10.1002/cphc.202200807.
Amphiphilic Near‐Infrared Fluorescent Molecular Probes: Optical Properties in Solution and in Surfactant Micelle Microenvironment
Authors: Samaniego Lopez Cecilia , Verónica Rivas M. , García Cambón Tomás A. , Wolosiuk Alejandro , Spagnuolo Carla C.
Published: March 2023

In this work, the optical properties of two novel near‐infrared fluorescent tricarbocyanines with amphiphilic nature, CyN and CyS, were studied in solution and in micelles of representative surfactants (anionic, cationic and non‐ionic) by means of spectroscopic techniques. Interestingly, the spectral properties of the new fluorophores depend on the nature of the heteroatom at the meso position. Dependence on the solvent polarity and the viscosity were also observed in both cases. Furthermore, changes on photophysical properties occurred upon encapsulation of the dyes. The incorporation of the dye from the aqueous solution to the surfactant supramolecular assembly produced a drastic change in the fluorescence emission from quenched state to fluorescence enhancement, rendering an OFF‐ON response to the exchange of environment. In addition, a significant protective effect against photobleaching was determined when the dyes were included in Pluronic® micelles (F127) resulting in a promising system to be used as a fluorescent nanosized container. The novel amphiphilic NIR fluorophores also interact as a Förster resonance energy transfer (FRET) pair and the process was studied within micelles loaded with both dyes.
Flexure‐axial‐shear interaction of ductile beams with single‐crack plastic hinge behaviour
Authors: Opabola Eyitayo A. , Elwood Kenneth J.
Published: March 2023

One of the key damage observations in modern reinforced concrete (RC) frame buildings, damaged following the 2010/2011 Canterbury and 2016 Kaikoura earthquakes, was localised cracking at the beam‐column interface of capacity‐designed beams. The localised cracking in the beams was due to curtailed longitudinal bars at the beam‐column interface. Following these observations, without experimental data to justify desirable seismic performance, modern beams controlled by localised cracking were assumed to be potentially earthquake‐vulnerable. To address this, an experimental program was carried out on six RC beam specimens susceptible to single‐crack plastic hinge behaviour due to curtailed longitudinal bars. The experimental data show that RC beams with single‐crack plastic hinge behaviour can undergo significant inelastic drift demands without loss of lateral resistance. However, contrary to conventional beams with distributed cracking, the response of RC beams with single‐crack plastic hinge behaviour due to curtailed longitudinal bars is mainly dominated by hinge rotation (via bond‐slip) and shear sliding at the column face. The current paper studies the interdependence of axial elongation, bond‐slip and shear sliding deformation of RC beams with single‐crack plastic hinge behaviour under cyclic demands. A procedure for seismic assessment of RC beams with single‐crack plastic hinge behaviour due to curtailed longitudinal bars is proposed. The proposed formulations can be adopted to develop adequate numerical models for simulating the response of RC frames with beams susceptible to single‐crack plastic hinge behaviour due to curtailed longitudinal bars.
The need to reorganize health research systems in pandemic crisis: A prospective study
Authors: Kharazmi Erfan , Ostovar Sedigheh , Ahmadi Marzaleh Milad
Published: March 2023

Background and Aims

A pandemic has posed a major challenge to health systems all over the world. All countries have realized that the only way to get real growth and development and solve their problems is to use what they have learned from research.

Methods

A descriptive and analytic type of study was conducted with the help of experts in the field of health research. The components affecting the research system were obtained via process approach and content analysis methods, and then the position of each component was identified by the Mic Mac technique.

Results

Seventeen influential structural components in the health research system were identified. The leadership and management components had the most direct and indirect influence among other components. The health promotion component had a greater dependency than the other components.

Conclusion

All health systems need to provide adequate financial resources and manpower to provide a useful research system. Human resources are the most important inputs to such a system. Components such as the research process, research sustainability, quality, or innovation in research can play a balancing role. Having the right infrastructures for creating, transferring, developing, and getting access to knowledge makes it possible to do systematic science. It is hoped that this science will be used in other results of the health research system, like improving the effectiveness or promoting health.
Spectrum of congenital heart disease in Nepal from 2002–2022: A systematic review and meta‐analysis
Authors: Shrestha Oshan , Thapa Niranjan , Karki Sagun , Khanal Prechha , Pant Prashant , Neopane Arun
Published: March 2023

Background

Congenital heart diseases are recognized as public health concerns worldwide and Nepal is no exception. This study aims to study congenital heart disease in Nepal on grounds of burden, commonest type, common presentations, and associated noncardiac anomalies so that its spectrum can be known for prompt diagnosis and adoption of screening protocols.

Methods

Relevant articles were searched in electronic databases using appropriate search terms and Boolean operators. Data were extracted in Excel and analyzed in Comprehensive Meta‐Analysis Software. The proportion was used as an effect measure and a fixed or random‐effect model was used as per the heterogeneity. Forest plots were used to give visual feedback.

Results

A total of nine studies were included in the qualitative and quantitative synthesis after a rigorous screening of imported studies. The prevalence of congenital heart disease was 0.7% (Proportion: 0.007; CI: 0.001–0.035; I2: 99.263%). The burden of atrial septal defect was 32.1%, ventricular septal defect was 31.1%, patent ductus arteriosus was 12.6% and Tetralogy of Fallot was 7.3%. The most common presentations were respiratory tract infection (54.7%), developmental delay (49.8%), difficulty in breathing (44.5%), failure to thrive (17.1%), and cyanosis (15.9%).

Conclusions

The prevalence of congenital heart disease in Nepal was 0.7% and the frequency of male patients was higher. The atrial septal defect was the commonest on the whole, while, Tetralogy of Fallot was the commonest among cyanotic variety. Respiratory tract infection was frequently seen at presentation and the most commonly associated noncardiac anomaly was the cleft palate.
Impact of convective tip condition on the transient thermal behavior of wet porous convective radiative exponential profiled inclined longitudinal fin structures subject to heat generation
Authors: Nagaraja Halammanavar Gangadharappa , Gireesha Bijjanal Jayanna
Published: March 2023

A convective‐radiative fully wet porous inclined longitudinal fin of exponential profile is the focus of the current work. The thermal behavior of the fin under unsteady conditions has been analyzed for adiabatic and convective boundary conditions. The exponential fin and its counterpart inverted exponential fin are simultaneously investigated by considering temperature‐relevant thermal conductivity and heat generation. The modeled governing equation upon nondimensionalization reduces to a partial differential equation which is computed by employing the finite difference approach. The impact of relevant parameters like the convective parameter, radiative parameter, wet porous parameter, dimensionless time, exponential index, dimensionless ambient temperature, generation number, thermal conductivity parameter, and angle of inclination on thermal characteristics of exponential and inverted exponential fin structures with adiabatic and convective boundary restrictions have been examined. One of the main outcomes was that the inverted exponential fin with an adiabatic tip gives rise to the highest thermal curve, and the tapered exponential fin with a convective tip resulted in the lowest thermal curve.
Protective effects of cordycepin pretreatment against liver ischemia/reperfusion injury in mice
Authors: Liu Yunxia , Sheng Mingwei , Jia Lili , Zhu Min , Yu Wenli
Published: March 2023

Introduction

Cordycepin has been reported to exhibit hepatic protective and anti‐inflammatory properties. Here, we investigated the role of cordycepin in ischemia/reperfusion (IR)‐induced liver injury in a mouse model.

Methods

Mice were pretreated with cordycepin by gavage for 3 weeks, followed by the establishment of the IR modeling. Liver injury, Suzuki's histological grading, hepatic apoptosis, and inflammatory responses were evaluated by biochemical and pathological analysis.

Results

It was found that Cordycepin pretreatment at 50 mg/kg for 3 weeks attenuated IR‐induced liver injury, as reflected by the significant decrease of the levels of aspartate aminotransferase, alanine transaminase, lactate dehydrogenase, and low‐density lipoprotein. Cordycepin pretreatment also reduced histopathological changes, attenuated hepatocyte apoptosis, inflammatory responses in the livers of IR mice. Mechanically, toll‐like receptor 4/nuclear factor kappa‐B signaling in liver tissues was inhibited by Cordycepin pretreatment.

Conclusions

In conclusion, Cordycepin pretreatment protects IR‐induced liver injury, which demonstrates its potential for the treatment of IR in the liver.
Reframing caring for parents who struggle with substance‐use disorders
Authors: Mayes Linda C.
Published: March 2023

Nancy Suchman and the colleagues she influenced have produced ground‐breaking and attitude‐challenging work in understanding how parenting and substance use come together. Dr Suchman and her colleagues make the claim that there is nothing about a substance‐use disorder that precludes effective and sensitive caring for children especially with interventions that focus on the parent–child relationship. Suchman's legacy is to highlight how substance use as an illness pulls individuals away from important, caring relationships and limits their giving themselves to those relationships. Restoring the salience of caring relationships and of the individual's ability to care may be as impactful on their substance use as a strict focus on the reduction of drug use and achieving abstinence.
Three‐dimensional, label‐free cell viability measurements in tissue engineering scaffolds using optical coherence tomography
Authors: Babakhanova Greta , Agrawal Anant , Arora Deepika , Horenberg Allison , Budhathoki Jagat B. , Dunkers Joy P. , Chalfoun Joe , Bajcsy Peter , Simon Carl G.
Published: March 2023

In the field of tissue engineering, 3D scaffolds and cells are often combined to yield constructs that are used as therapeutics to repair or restore tissue function in patients. Viable cells are often required to achieve the intended mechanism of action for the therapy, where the live cells may build new tissue or may release factors that induce tissue regeneration. Thus, there is a need to reliably measure cell viability in 3D scaffolds as a quality attribute of a tissue‐engineered medical product. Here, we developed a noninvasive, label‐free, 3D optical coherence tomography (OCT) method to rapidly (2.5 min) image large sample volumes (1 mm3) to assess cell viability and distribution within scaffolds. OCT imaging was assessed using a model scaffold‐cell system consisting of a polysaccharide‐based hydrogel seeded with human Jurkat cells. Four test systems were used: hydrogel seeded with live cells, hydrogel seeded with heat‐shocked or fixed dead cells and hydrogel without any cells. Time series OCT images demonstrated changes in the time‐dependent speckle patterns due to refractive index (RI) variations within live cells that were not observed for pure hydrogel samples or hydrogels with dead cells. The changes in speckle patterns were used to generate live‐cell contrast by image subtraction. In this way, objects with large changes in RI were binned as live cells. Using this approach, on average, OCT imaging measurements counted 326 ± 52 live cells per 0.288 mm3 for hydrogels that were seeded with 288 live cells (as determined by the acridine orange‐propidium iodide cell counting method prior to seeding cells in gels). Considering the substantial uncertainties in fabricating the scaffold‐cell constructs, such as the error from pipetting and counting cells, a 13% difference in the live‐cell count is reasonable. Additionally, the 3D distribution of live cells was mapped within a hydrogel scaffold to assess the uniformity of their distribution across the volume. Our results demonstrate a real‐time, noninvasive method to rapidly assess the spatial distribution of live cells within a 3D scaffold that could be useful for assessing tissue‐engineered medical products.
A density functional theory study of van der Waals interaction in carbon nanotubes
Authors: Wang Houng‐Wei , Hayashi Michitoshi
Published: March 2023

In this article, we investigate the effect of van der Waals force in zigzag carbon nanotubes (CNTs) including single‐wall CNT (SWCNT) and double‐walled CNT (DWCNT) structures with several interaction configurations. The solid‐state density functional theory is employed to calculate the geometric optimization, normal mode frequencies, and IR and Raman spectra with the periodic boundary condition. For SWCNTs, we find that the Raman intensity is not affected by the tube diameter or the electronic structure. The IR absorption, however, increases with the tube diameter. We find that the close metallicity of the electronic structure has a significant impact on the IR simulations. When the van der Waals force is applied outside the CNTs at a distance longer than 3.0, the effect on Raman spectra is minimal but some effects can still be confirmed by IR absorption. When the van der Waals force acts inside the CNTs, the effect on the spectrum can be observed, especially at a distance of 2.8 Å, both IR and Raman can be significantly enhanced in many modes.
NIR‐II fluorescent nanophosphors for bio‐imaging
Authors: Satpathy Aishwarya , Su Ting‐Yi , Huang Wen‐Tse , Liu Ru‐Shi
Published: March 2023

The design of nanoprobes in the second window near‐infrared region has grasped a substantial amount of attention due to the flexible emission in the second near‐infrared region (NIR‐II) region (1,000–1,700 nm). In addition, this region provides the advantage of reduced photon scattering with less autofluorescence for improvement during in vivo fluorescence imaging. NIR‐II nanoprobes such as quantum dots, AIEgens, carbon nanotubes, and polymers are in a constant state of evolution for improved NIR‐II emission. Among these probes, lanthanides are explored the most for NIR‐II imaging applications. Moreover, nanophosphors, although in their nascent form, are interesting compounds due to their good luminescence properties with efficient energy transfer processes. Our review aims to give insight into nanophosphors, mainly for biological imaging applications. We will also provide a comparative study of lanthanides and nanophosphors for understanding the mechanism and importance of nanophosphors in the future bio‐imaging field.
Rapid two‐stage amplification in a single tube for simultaneous detection of norovirus GII and group a rotavirus
Authors: Li Feng‐yu , Guo Ying‐hui , Sun Zhen‐lu , Liu Hong , Zhao Meng‐chuan , Cui Jia , Jiang Yue , Shen Xin‐xin , Ma Xue‐jun , Feng Zhi‐shan
Published: March 2023

The most prevalent viruses currently causing diarrhea are norovirus and rotavirus, and rapid and sensitive detection methods are essential for the early diagnosis of disease. The purpose of this study was to establish a sensitive single‐tube two‐stage nucleic acid amplification method—reverse transcription recombinase‐assisted PCR (RT‐RAP)—for simultaneous detection of norovirus GII and group A Rotavirus, with the first stage consisting of isothermal reverse transcription recombinase‐aided amplification (RT‐RAA) and the second stage consisting of qPCR (quantitative PCR). RT‐RAP is more sensitive than either RT‐RAA or qRT‐PCR (quantitative RT‐PCR) alone. And the addition of a barrier that can be disassembled after heating enabled the detection of samples within 1 h in a single closed tube. Sensitivity was 10 copies/reaction of norovirus (Novs) GII and group A rotavirus (RVA). In parallel, two hundred fecal specimens were used to evaluate the method and compare it with a commercial fluorescent quantitative RT‐PCR. The data showed kappa values of 0.957 and 0.98 (p < 0.05) for detecting Novs GII and RVA by the two methods, indicating the potential of the newly established assay to be applied to clinical and laboratory testing.
Keep thinking about unanswered questions in primary care: Cultivating negative capability
Authors: Son Daisuke , Inoue Kazuoki , Kamimoto Minako , Taniguchi Shin‐ichi
Published: March 2023

Negative capability or tolerance for uncertainty is important for primary care physicians. The 2022 edition of the Model Core Curriculum for Medical Education also states that the content of professionalism is to “keep thinking about unanswerable questions.”
The origin and evolution of emerged swine acute diarrhea syndrome coronavirus with zoonotic potential
Authors: Yu De , Zhao Zhuang‐Yan , Yang Yong‐Le , Qin Yu , Pan Dan , Yuan Li‐Xia , Huang Yao‐Wei , Wang Bin
Published: March 2023

Swine acute diarrhea syndrome coronavirus (SADS‐CoV) is a newly discovered alphacoronavirus with zoonotic potential that causes diarrhea and vomiting mainly in piglets. Having emerged suddenly in 2017, the prevailing opinion is that the virus originated from HKU2, an alphacoronavirus whose primary host is bats, and at some unknown point achieved interspecies transmission via some intermediate. Here, we further explore the evolutionary history and possible cross‐species transmission event for SADS‐CoV. Coevolutionary analysis demonstrated that HKU2 may have achieved host switch via SADS‐related (SADSr)‐CoV, which was isolated from the genus Rhinolophus in 2017. SADS‐CoV, HKU2, and SADSr‐CoV share similar codon usage patterns and showed a lower tendency to use CpG, which may reflect a method of immune escape. The analyses of virus‐host coevolution and recombination support SADSr‐CoV is the direct source of SADS‐CoV that may have undergone recombination events during its formation. Structure‐based spike glycoprotein variance analysis revealed a more nuanced evolutionary pathway to receptor recognition for host switch. We did not find a possible positive selection site, and the dN/dS of the S gene was only 0.29, which indicates that the current SADS‐CoV is slowly evolving. These results provide new insights that may help predict future cross‐species transmission, and possibly surveil future zoonotic outbreaks and associated public health emergencies.
Increasing rates of general anesthesia use in lumpectomy procedures: A 15‐year trends analysis
Authors: Rubenstein Robyn N. , Tadros Audree , Slutsky Hanna L. , Plotsker Ethan L. , Haglich Kathryn , Stern Carrie S. , Morrow Monica , Nelson Jonas A. , Nelson Priscilla
Published: March 2023

Background

Anesthesia methods in oncologic breast surgery have evolved with less invasive practices. The aims of this study were primarily to examine trends in anesthesia type used during lumpectomy.

Methods

We analyzed lumpectomy procedures from 2005 to 2019 using the NSQIP database. Upon defining the nadir in general anesthesia (GA) and peak in monitored anesthesia care (MAC) use as 2007, we compared patient characteristics and complications in the 2007 versus 2019 GA and MAC cohorts. Multivariable logistic regression was used to examine associations with receipt of GA.

Results

Of 253 545 lumpectomy patients, 191 773 (75.6%) received GA and 61 772 (24.4%) received MAC. From 2005 to 2019, GA rates increased from 66.7% to 82.5%, while MAC rates decreased from 33.3% to 17.5%. More GA patients were obese and American Society of Anesthesiologists class 3. Over time, age and body mass index (BMI) increased in both GA and MAC cohorts. Odds of receiving GA increased over time, and predictors included concurrent axillary lymph node dissection (p < 0.0001) or sentinel lymph node biopsy (p < 0.0001).

Conclusions

We demonstrate increasing use of GA over time for lumpectomy, which may be related to aging lumpectomy patient population with higher BMIs. We also find a strong association between use of GA and concurrent lymph node procedures.
Optical coherence tomography biomarkers for myopic choroidal neovascularization treated with anti‐vascular endothelial growth factor
Authors: Lee Daniel Yu , Wu Po‐Ying , Sheu Shwu‐Jiuan
Published: March 2023

In recent years, optical coherence tomography (OCT) biomarkers for specific retinal diseases have been found to be associated with treatment outcome and disease recurrence. The main purposes of this study were to identify OCT biomarkers for myopic choroidal neovascularization (mCNV) treated with intravitreal injection of anti‐vascular endothelial growth factor (anti‐VEGF). OCT features in 43 eyes of 39 patients with mCNV treated with anti‐VEGF with at least 1 year of follow‐up were retrospectively analyzed. Eyes with subretinal hyperreflective material (SHM) in baseline spectral‐domain OCT (SD‐OCT) had significantly more visual improvement than eyes without SHM at month 6 (p = 0.007) and had a trend of more visual improvement than eyes without SHM (p = 0.058) at month 12. Eyes with subretinal fluid (SRF) at baseline had significantly more central retinal thickness (CRT) decrease than patients without SRF at month 6 and 12 (p = 0.012 and 0.006 respectively). In univariate regression analysis, dome‐shaped macula (DSM), SRF in baseline OCT image and fuzzy border of mCNV when entering pro re nata (PRN) injection protocol tended to have higher risk of disease recurrence in 1 year (odds ratio: 14.86 (p = 0.003), 3.75 (p = 0.049) and 22.92 (p < 0.001) respectively). However, they were not significant in multivariate regression analysis. OCT biomarkers at baseline could provide prognostic information for mCNV management.
Enhancing High‐Temperature Energy Density through Al2O3 Nanoplates with Charge Barrier Effect in Polyetherimide‐Based Composites
Authors: Yang Xuelin , Li Hongye , Xie Xinyue , Liu Xiaolin
Published: March 2023

Polymer‐based dielectric composites have a wide range of applications in modern electronics and power systems owing to their incomparable reliability, but remain a challenge to energy density at high temperatures. In this work, polyetherimide (PEI)‐based nanocomposites with a small amount of aluminium oxide (Al2O3) nanoplates are prepared and obtain excellent energy density at elevated temperatures. The high‐temperature energy density of the nanocomposites is significantly improved and reaches to 5.2 J cm−3 at 550 kV mm−1 and 150 °C after adding 0.6 wt% Al2O3 nanoplates. The enhanced energy density is attributed to the wide band gap and flaky morphology of Al2O3 nanoplates that can induce charge barrier effect and thus reduce the leakage current density within the nanocomposites. Furthermore, finite element simulations further reveal the mechanism of Al2O3 nanoplates acting as charge barrier to capture the charges transmitted from PEI matrix at the interface. This work offers a promising pathway to high‐energy density polymer dielectrics capable of operating under high temperatures.
Fabrication of Surface Polymer Brushes Via Thin Film Crystallization and Solvent Annealing
Authors: Wilk Jeffrey T. , Chancellor Andrew J. , Mei Shan , Qian Qian , Zhao Bin , Li Christopher Y.
Published: March 2023

Polymer single crystals are used as templates to synthesize polymer brushes, known as the “polymer‐single‐crystal‐assisted‐grafting‐to” (PSCAGT) approach. Polymer brushes with controlled grafting densities and spatial tethering locations are demonstrated. Previous works focused on solution crystallization, which involves large amounts of organic solvent, and the grafting density can only be tuned by varying crystallization temperatures. In this work, thin film crystallization is utilized to fabricate 2D polymer crystals on flat surfaces. Subsequent chemical tethering leads to polymer brushes that retain the original morphology of the crystals with high fidelity. Furthermore, it is shown that the grafting density of the polymer brushes fabricated using this method depends on the chain end distribution on the top/bottom surfaces of the crystal, which can be facilely controlled by annealing the crystals at various nonsolvent media. This work broadens the scope of the PSCAGT method and provides a new route to achieve polymer brushes with controlled structures.
The Siren Call of Complacency
Authors: Wich Scott
Published: March 2023

Let's face it: if “Inbox Zero” were readily achievable, there would not be countless articles, blogs, and strategies suggesting ways to achieve this seemingly unattainable status. The elusiveness of the goal and our never‐ending efforts to address it are symptomatic of a larger, widely accepted concern. To state the obvious, managers and supervisors are busy. Inbox Zero is elusive because too frequently we have more items to handle than time in which to handle them. People faced with this challenge resort to varying strategies. Some address the “squeakiest” wheels; others address the tightest deadlines or the hottest fires. In all such instances, individuals engage in a form of triage. They address the highest priority items first; however, that priority might be measured.
Temporal disturbance of a model stream ecosystem by high microbial diversity from treated wastewater
Authors: Stach Tom L. , Sieber Guido , Shah Manan , Simon Sophie A. , Soares André , Bornemann Till L. V. , Plewka Julia , Künkel Julian , Becker Christian , Meyer Folker , Boenigk Jens , Probst Alexander J.
Published: March 2023

Microbial communities in freshwater streams play an essential role in ecosystem functioning via biogeochemical cycling. Yet, the impacts of treated wastewater influx into stream ecosystems on microbial strain diversity remain mostly unexplored. Here, we coupled full‐length 16S ribosomal RNA gene Nanopore sequencing and strain‐resolved metagenomics to investigate the impact of treated wastewater on a mesocosm system (AquaFlow) run with restored river water. Over 10 days, community Bray–Curtis dissimilarities between treated and control mesocosm decreased (0.57 ± 0.058 to 0.26 ± 0.046) based on ribosomal protein S3 gene clustering, finally converging to nearly identical communities. Similarly, strain‐resolved metagenomics revealed a high diversity of bacteria and viruses after the introduction of treated wastewater; these microbes also decreased over time resulting in the same strain clusters in control and treatment at the end of the experiment. Specifically, 39.2% of viral strains detected in all samples were present after the introduction of treated wastewater only. Although bacteria present at low abundance in the treated wastewater introduced additional antibiotic resistance genes, signals of naturally occurring ARG‐encoding organisms resembled the resistome at the endpoint. Our results suggest that the previously stressed freshwater stream and its microbial community are resilient to a substantial introduction of treated wastewater.
Parkin exerts the tumor‐suppressive effect through targeting mitochondria
Authors: Sun Xin , Ye Guiqin , Mai Yuanyuan , Shu Yuhan , Wang Lei , Zhang Jianbin
Published: March 2023

The role of PARKIN in Parkinson's disease is well established but its role in cancer has recently emerged. PARKIN serves as a tumor suppressor in many cancers and loses the tumor‐suppressive function due to loss of heterozygosity and DNA copy number. But how PARKIN protects against cancer is poorly understood. Through the analysis of PARKIN substrates and their association with mitochondria, this viewpoint discussed that PARKIN exerts its anti‐cancer activity through targeting mitochondria. Mitochondria function as a convergence point for many signaling pathways and biological processes, including apoptosis, cell cycle, mitophagy, energy metabolism, oxidative stress, calcium homeostasis, inflammation, and so forth. PARKIN participates in these processes through regulating its mitochondrial targets. Conversely, these mitochondrial substrates also influence the function of PARKIN under different cellular circumstances. We believe that future studies in this area may lead to novel therapeutic targets and strategies for cancer therapy.
The propagation of strong cylindrical shock wave in a rotating axisymmetric non‐ideal gas with radiation heat flux
Authors: Yadav Shalini , Singh Deepika , Arora Rajan
Published: March 2023

In this manuscript, we studied a quasi‐linear hyperbolic system of partial differential equations which describes the one‐dimensional adiabatic unsteady flow behind a strong cylindrical shock wave propagating in a rotating non‐ideal gas, which has a varying azimuthal fluid velocity together with a varying axial fluid velocity, with radiation heat flux, and similarity solutions are obtained by using the Lie group‐theoretic method. The basic idea of this method is that it changes the system of PDEs representing the one‐dimensional flow through the similarity variable to the system of ODEs. The flow profiles are drawn behind the shock followed by a brief discussion on the behavior of the solutions via graphs. The effects of variation in non‐ideal parameter, adiabatic index of the gas, Alfven–Mach number and ambient azimuthal velocity exponent on the flow variables are described. All numerical calculations have been performed using the “Mathematica” software.
Reduction of discrete‐time infectious disease models
Authors: Bravo de la Parra Rafael
Published: March 2023

In this work, we propose the construction of discrete‐time systems with two time scales in which infectious diseases dynamics are involved. We deal with two general situations. In the first, we consider that individuals affected by the disease move between generalized sites on a faster time scale than the dynamics of the disease itself. The second situation includes the dynamics of the disease acting faster together with another slower general process. Once the models have been built, conditions are established so that the analysis of the asymptotic behavior of their solutions can be carried out through reduced models. This is done using known reduction results for discrete‐time systems with two time scales. These results are applied in the analysis of two new models. The first of them illustrates the first proposed situation, being the local dynamics of the SIS‐type disease. Conditions are found for the eradication or global endemicity of the disease. In the second model, a case of co‐infection with a primary disease and an opportunistic disease is treated, the latter acting faster than the former. Conditions for eradication and endemicity of co‐infection are proposed.
Mechanical model for geomechanical pumped storage in horizontal fluid‐filled lenses
Authors: Bunger Andrew P. , Lau Henry , Wright Scott , Schmidt Howard
Published: March 2023

Pumped subsurface energy storage entails pumping fluid into fluid‐filled lenses in subterranean rock formations during times of peak power production, and then later producing the fluid back to the surface to drive a turbine. A new mechanical model is developed for lens behavior during flowback (production), shut‐in, and inflation (storage) stages. The model couples elastic deformation of the lens with Darcy–Weisbach fluid flow spanning the laminar to turbulent regimes. It includes an energy‐based inlet boundary condition governing fluid flow rate out of the lens and up to the Earth's surface. It also introduces pressure‐dependent leakoff of fluid to the surrounding rock and the impact of intact rock bridges, which can arise from the lens having multiple petals or lobes, on lens compliance. The model is then used to illustrate the transition from early‐time gradual decline in wellhead pressure and flow rate to eventual pinching of the lens width at the wellbore, leading to rapid decline of pressure and flow rate. The model demonstrates the feasibility of efficient storage cycles that generate a desired amount of power over a desired time while avoiding pinching. Maximizing efficiency is shown to have at least two contrasting regimes depending on whether the fluid leakoff rate to the host rock is dependent on the fluid pressure. The development of this model is therefore an essential step in deployment of subsurface energy storage by providing a mechanical basis for storage lens design.
Slice‐specific tracking for free‐breathing diffusion tensor cardiac MRI
Authors: Xu Xi , Hu Junpu , Zheng Yijia , Liu Yuanyuan , Cui Zhuoxu , Liang Dong , Zhu Yanjie
Published: March 2023

Background

Diffusion tensor cardiac magnetic resonance (DT‐CMR) imaging has great potential to characterize myocardial microarchitecture. However, its accuracy is limited by respiratory and cardiac motion and long scan times. Here, we develop and evaluate a slice‐specific tracking method to improve the efficiency and accuracy of DT‐CMR acquisition during free breathing.

Methods

Coronal images were obtained along with signals from a diaphragmatic navigator. Respiratory and slice displacements were obtained from the navigator signals and coronal images, respectively, and these displacements were fitted with a linear model to obtain the slice‐specific tracking factors. This method was evaluated in DT‐CMR examinations of 17 healthy subjects, and the results were compared with those obtained using a fixed tracking factor of 0.6. DT‐CMR with breath‐holding was used for reference. Quantitative and qualitative evaluation methods were used to analyze the performance of the slice‐specific tracking method and the consistency between the obtained diffusion parameters.

Results

In the study, the slice‐specific tracking factors showed an upward trend from the basal to the apical slice. Residual in‐plane movements were lower in slice‐specific tracking than in fixed‐factor tracking (RMSE: 2.748 ± 1.171 versus 5.983 ± 2.623, P < 0.001). The diffusion parameters obtained using slice‐specific tracking were not significantly different from those obtained from breath‐holding acquisition (P > 0.05).

Conclusion

In free‐breathing DT‐CMR imaging, the slice‐specific tracking method reduced misalignment of the acquired slices. The diffusion parameters obtained using this approach were consistent with those obtained with the breath‐holding technique.
Interface flux recovery framework for constructing partitioned heterogeneous time‐integration methods
Authors: Sockwell K. Chad , Bochev Pavel , Peterson Kara , Kuberry Paul
Published: March 2023

A common approach for the development of partitioned schemes employing different time integrators on different subdomains is to lag the coupling terms in time. This can lead to accuracy issues, especially in multistage methods. In this article, we present a novel framework for partitioned heterogeneous time‐integration methods, which allows the coupling of arbitrary multistage and multistep methods without reducing their order of accuracy. At the core of our approach are accurate estimates of the interface flux obtained from the Schur complement of an auxiliary monolithic system. We use these estimates to construct a polynomial‐in‐time approximation of the interface flux over the current time coupling window. This approximation provides the interface boundary conditions necessary to decouple the subdomain problems at any point within the coupling window. In so doing our framework enables a flexible choice of time‐integrators for the individual subproblems without compromising the time‐accuracy at the coupled problem level. This feature is the main distinction between our framework and other approaches. To demonstrate the framework, we construct a family of partitioned heterogeneous time‐integration methods, combining multistage and multistep methods, for a simplified tracer transport component of the coupled air‐sea system in Earth system models. We report numerical tests evaluating accuracy and flux conservation for different pairs of time‐integrators from the explicit Runge‐Kutta and Adams‐Moulton families.
An interaction effect of external noise and exposure duration on the spatial contrast sensitivity function
Authors: Zhang Pan , Ren Weicong , Meng Hu , Wang Jialei , Lu Qing , Chen Ge , Li Chenxi , Li Ying , Zhang Shilei , Tao Jiayu , Wu Di
Published: March 2023

It has been demonstrated that contrast sensitivity is sensitive to stimulus exposure duration. Here, we investigated how the duration effect on contrast sensitivity was modulated by the spatial frequency and intensity of external noise. Through a contrast detection task, the contrast sensitivity function under 10 spatial frequencies, three external noise, and two exposure duration conditions was measured. The temporal integration effect was defined by the difference in contrast sensitivity or the area under the log contrast sensitivity function between short and long exposure durations. We found that (1) the temporal integration effect was less pronounced in the zero‐noise condition than in the low‐ or high‐noise condition; (2) in the zero‐noise condition, a stronger temporal integration effect was observed at high spatial frequencies; (3) in the high‐noise condition, a stronger temporal integration effect was observed at low spatial frequencies; (4) the spatial‐frequency‐dependent transient or sustained mechanism is also sensitive to external noise level; and (5) perceptual template model analysis revealed that both decreased additive internal noise and an improved perceptual template accounted for the temporal integration effect, and these two factors were tuned to spatial frequency.
Engaging and collaborating with families across multitiered systems of support: Current school psychologists' practices
Authors: Hendricker Elise , Bender Stacy L. , Ouye Jenna
Published: March 2023

The National Association of School Psychologists emphasizes consultation, collaboration, and family–school–community collaboration as domains within school psychology practice. Family engagement is defined as caregiver participation in children's learning and instruction. While research outlines best practices in engaging and collaborating with families across multitiered systems of support (MTSS), there has been little examination of the current practices of school psychologists within this domain. This study investigated family engagement practices in schools, school psychologists' involvement in these practices, and their perceived effectiveness. Results indicated that while family engagement and problem‐solving consultation methods were used within MTSS, school psychologists were less involved in implementation. Implications and future research are discussed.
The association between purpose in life and knowledge sharing behavior among Chinese university students: The mediating effects of gratitude
Authors: Guo Yungui , Luo Shiyu , Tan Yu
Published: March 2023

In the era of knowledge economy, how to promote knowledge sharing behavior of university students deserves close attention from academic and practical circles. As a character strength, purpose in life can predict individuals' thriving and positive development, but its predictive effect on knowledge sharing behavior has not been explored. This study investigated the association between purpose in life (meaningfulness, goal orientation, and beyond‐the‐self) and knowledge sharing behavior, and the potential mediating effect of gratitude. Data were collected from 493 students (mean age = 20.86, standard deviation= 1.69) from two universities in the Hunan province of China. They completed the scales of purpose in life, gratitude, and knowledge sharing behavior in June 2022. This study conducted structural equation model analysis to test the hypothetical model. The results showed that goal orientation and beyond‐the‐self positively predicted knowledge sharing behavior, and gratitude partially mediated the association between goal orientation and knowledge sharing behavior, and beyond‐the‐self and knowledge sharing behavior. The findings highlight the importance of purpose in life and gratitude in promoting knowledge sharing behavior among university students.
Vertical GaN Transistor with Semi‐Insulating Channel
Authors: Šichman Peter , Stoklas Roman , Hasenöhrl Stanislav , Gregušová Dagmar , Ťapajna Milan , Hudec Boris , Haščík Štefan , Hashizume Tamotsu , Chvála Aleš , Šatka Alexander , Kuzmík Ján
Published: March 2023

Herein, vertical GaN transistors with a semi‐insulating (SI) 1.3 μm thick channel layer and C doping of 1 × 1017 cm−3 are studied. Structures are grown using a metal–organic chemical vapor deposition on conductive GaN substrates. SI GaN is sandwiched between 2.5 μm thick n‐GaN drift layer (Si doping of ≈ 1 × 1017 cm−3) and a top n‐GaN contact layer. A circular mesa region with a diameter of 180 μm is patterned using a deep dry etching. The gate contact formed on the mesa sidewall is insulated from the vertical channel using a 20 nm thick Al2O3 grown by an atomic layer deposition. Despite a robust layout, transistors transfer characteristics indicate normally off behavior if extracted from the linearly scaled current–voltage characteristics and an open channel drain current of 30 mA at the gate bias of 4 V. Achieved on/off ratio is 107 at −2 V subthreshold gate bias when the full channel depletion is reached. And, 200 ns long gate pulse characteristics show only a marginal trapping even though no post‐metallization annealing is performed. By comparing experimental results with modeling, mobility of free electrons in the channel is found to be about 45 cm2 V−1 s−1.
Prediction of Ta2C‐Type Vacancy‐Layered Structures in the Ternary Hf–Ta–C System
Authors: Peng Junhui , Tikhonov Evgenii
Published: March 2023

Herein, the vacancy‐ordered structures in the ternary Hf–Ta–C system are investigated by the first‐principles method and evolutionary algorithms. In addition to the rocket‐salt structure, two Ta2C‐type structures, HfTa2C2 and Hf2Ta2C3, are predicted, and their space groups are determined to be R‐3m. In these two structures, the vacancy layers are formed perpendicular to the c‐axis, and the vacancies occupy the [Ta6] octahedral interstices. Furthermore, the electronic properties of HfTa2C2 and Hf2Ta2C3, such as the electron‐localization function, density of state, band structure, partial charge density, and charge–density distribution, are calculated and analyzed. It is shown in the results that the localized electrons locate in the layered vacancies originating from the Ta atoms and that they form localized metallic bonds. Therefore, HfTa2C2 and Hf2Ta2C3 exhibit higher elastic modulus and Vickers hardness than the rock‐salt structure.
Pressure Effect on Diffusion of Native Defects and Mg Impurity in Mg‐Ion‐Implanted GaN during Ultrahigh‐Pressure Annealing
Authors: Kano Emi , Otsuki Ritsuo , Kobayashi Koki , Kataoka Keita , Sierakowski Kacper , Bockowski Michal , Nagao Masahiro , Narita Tetsuo , Kachi Tetsu , Ikarashi Nobuyuki
Published: March 2023

Herein, transmission electron microscopy direct observations are used to examine the time evolution of dislocation loops in Mg‐ion‐implanted GaN during annealing in N2 atmospheres of 2.0 and 0.3 GPa. It is indicated in the results that the diffusion of the native defects, for both interstitials and vacancies, is retarded during annealing at the higher pressure. Furthermore, secondary ion mass spectrometry shows that annealing at the higher pressure retards the migration of Mg and increases Mg‐acceptor concentration in the ion‐implanted region. These findings provide a design principle of the postimplantation annealing process to activate ion‐implanted Mg in GaN.