bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyanogenesis in Aralia spinosa (Araliaceae)
Authors: Lechtenberg Matthias , Sendker Jandirk , Kastner Lisa , Hensel Andreas
Published: November 2021

A systematic survey of Aralia spinosa (Araliaceae), covering an entire growing season and including aboveground organs at various developmental stages, revealed that only about half of all samples collected showed cyanogenesis. Cyanogenesis was detected in inflorescences and leaves but is apparently restricted to certain harvest times or developmental stages. The structurally unusual triglochinin, characterized by a hex-2-enedioic acid partial structure, was the only cyanogenic glycoside detected. This is the first description of triglochinin in this species and in the family of Araliaceae. Triglochinin is biogenetically derived from tyrosine, which is in good agreement with the few cyanogenic glycosides previously detected in members of the Araliaceae family. Triglochinin was identified, characterized, and quantified by modern chromatographic methods, and the amount of enzymatically releasable hydrocyanic acid was determined qualitatively and quantitatively. Two
isomers of triglochinin were detected chromatographically at minor levels. The isomeric pattern agreed well with literature data from other triglochinin-containing plants. This was confirmed in the two species, Triglochin maritima and Thalictrum aquilegiifolium, which were comparatively studied. In the case of A. spinosa, inflorescence buds harvested in July showed the highest content of triglochinin, just under 0.2% on a dry weight basis. The detection of triglochinin adds to the knowledge of toxicological properties and the dereplication of U(H)PLC/MS² data provides a comprehensive phytochemical profile of A. spinosa.
Investigating the Relationship between Childbirth Type and Breastfeeding Pattern Based on the LATCH Scoring System in Breastfeeding Mothers
Authors: Mokhtari Sorkhani Tayebeh , Namazian Elahe , Komsari Samaneh , Arab Shima
Published: November 2021

Objective The role of breast milk in the physical and mental health of infants and in the prevention of infant death is widely known. The benefits of breastfeeding for mothers and infants have been proven, but several factors can affect breastfeeding. Childbirth is one of the most influential factors. The present study aimed to investigate the effect of the type of delivery (natural childbirth and cesarean section) on breastfeeding based on the latch, audible swallowing, type of nipple, comfort, hold (LATCH) scoring system.

Methods The present cross-sectional observational study was performed using the census method among women who referred to Afzalipour Hospital for delivery in May 2020; the breastfeeding pattern was completed by observation and the in-case information, by LATCH checklist. Data were analyzed using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Armonk, NY, United States) software, version 19.0, analysis of variance (ANOVA), and the Chi-squared statistical test.

Results Out of a total of 254 deliveries (127 natural childbirths and 127 cesarean deliveries), there was no statistically significant difference between the 2 study groups in terms of age, maternal employment status, and infant weight, but there was a statistically significant relationship between the type of delivery, the maternal level of schooling, and the appearance, pulse, grimace, activity, and respiration (Apgar) score in the first minute. The mean score of breastfeeding patterns among the natural childbirth group (9.33) was higher than that of the cesarean section group (7.21).

Conclusion The type of delivery affects the mother's performance during breastfeeding, and mothers submitted to cesarean sections need more support and help in breastfeeding.
Thyroid Function of Pregnant Women and Perinatal Outcomes in North Macedonia
Authors: Avramovska Maja , Kostova Neda Milevska , Karanfilski Borislav , Hunziker Sandra , Vaskova Olivija , Dimitrov Goran , Dzikova Elena , Markova Ana Daneva , Lega Marija Hadzi , Tofoski Gligor , Sikole Aleksandar
Published: November 2021

Objective Thyroid diseases are the second most common endocrine disorders in the reproductive period of women. They can be associated with intrauterine growth restriction (IUGR), preterm delivery, low Apgar score, low birthweight (LBW) or fetal death. The aim of the present study is to explore thyroid dysfunction and its relationship with some poor perinatal outcomes (Apgar Score, low birthweight, and preterm delivery).

Methods Dried blood spot samples from 358 healthy pregnant women were analyzed for thyroid stimulating hormone (TSH), total thyroxine (TT4), and thyroglobulin (Tg). Neonatal data were collected upon delivery. Four groups were formed based on thyroid function tests (TFTs).

Results Of the 358 tested women, 218 (60.72%) were euthyroid. Isolated hypothyroxinemia was present in 132 women (36.76%), subclinical hyperthyroidism in 7 women (1.94%), and overt hypothyroidism in 1 (0.28%). The perinatal outcomes IUGR (p = 0.028) and Apgar score 1 minute (p = 0.015) were significantly different between thyroid function test [TFT]-distinct groups. In the multiple regression analysis, TT4 showed a statistically significant inverse predictive impact on LBW (p < 0.0001), but a positive impact of Tg on LBW (p = 0.0351).

Conclusion Thyroid hormones alone do not have a direct impact on neonatal outcomes, but the percentage of their participation in the total process cannot be neglected. Based on the regression analysis, we can conclude that TT4 and Tg can be used as predictors of neonatal outcome, expressed through birthweight and Apgar score. The present study aims to contribute to determine whether a test for thyroid status should become routine screening during pregnancy.
Intraoperative Assessment of Endogenous Microbiota in the Breast
Authors: Stachon Henrique , Amoroso Vanessa , Urban Cicero , Bioni Pamela , Spautz Cleverton , Lima Rubens Silveira de , Anselmi Karina , Kuroda Flávia , Rabinovich Iris , Alvarez Thabata , Monteiro Juliane
Published: November 2021

Objective: Breast surgery is considered a clean surgery; however, the rates of infection range between 3 and 15%. The objective of the present study was to intraoperatively investigate the presence of autochthonous microbiota in the breast.

Methods: Pieces of breast tissue collected from 49 patients who underwent elective breast surgery (reconstructive, diagnostic, or oncologic) were cultured. The pieces of breast tissue were approximately 1 cm in diameter and were removed from the retroareolar area, medial quadrant, and lateral quadrant. Each piece of tissue was incubated in brain heart infusion (BHI) broth for 7 days at 37°C, and in cases in which the medium became turbid due to microorganism growth, the samples were placed in Petri dishes for culturing and isolating strains and for identifying species using an automated counter.

Results: Microorganism growth was observed in the samples of 10 of the 49 patients (20.4%) and in 11 of the 218 pieces of tissue (5%). The detected species were Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus epidermidis, Sphingomonas paucimobilis, and Aeromonas salmonicida. No patient with positive samples had clinical infection postoperatively.

Conclusion: The presence of these bacteria in breast tissue in approximately 20% of the patients in this series suggests that breast surgery should be considered a potential source of contamination that may have implications for adverse reactions to breast implants and should be studied in the near future for their oncological implications in breast implant-associated large-cell lymphoma etiology.
Perceived Stress and Resilience among Nurses Working in a Selected Hospital at Mangalore
Authors: Kannappan Sujatha R. , Veigas Jacintha
Published: November 2021

Objective A minimum amount of stress is essential for a successful life. When it goes beyond the limit, it affects overall well-being. There is a need to modify the environment, feelings, and physical factors of an individual to promote resilience. This study aimed to assess and find the relationship between perceived stress and resilience among nurses working in a selected hospital.

Materials and Methods The investigators used the descriptive correlation design and, through the nonprobability sampling method, selected 65 nurses. Data was collected using the demographic variables, perceived stress scale, and the Connor–Davidson resilience scale.

Results and Discussion The investigators found a moderate level of stress (61.5%) with intermediate resilience (73.8%) among the nurses and noted a weak correlation between perceived stress and resilience (calculated value is 0.226 and the p-value is 0.071). There was an association found between the frequency of night duty, education level, and perceived stress.

Conclusion Our study showed that most of the nurses had a moderate level of stress with intermediate resilience. The unmarried nurses were more resilient, with a moderate level of stress than the married.
Reverse Perilunate Injuries—The “Extended Scaphoid” Sign
Authors: Herzberg Guillaume , Burnier Marion , Druel Thibault
Published: November 2021

Background Reverse perilunate injuries (REPLI) are rare variants of the classic radial-sided perilunate injuries (PLI) whose mechanism was described by Mayfield in 1980. Classic radial-sided nontranscaphoid dorsal PLI invariably display a flexed, foreshortened position of the scaphoid on their initial posteroanterior (PA) and lateral radiographs. We observed that some dorsal perilunate dislocations displayed an extended position of the scaphoid on their initial radiographs. Our hypothesis is that this extended position of the scaphoid was associated with a REPLI pattern.

Methods The PA and lateral initial emergency radiographs of our specialized wrist surgery series of 114 dorsal pure ligamentous PLI (within a 186 cases series of PLI treated between 2004 and 2020) were reviewed as well as the available figures of the current REPLI literature.

Results A total of seven cases of cases within our dorsal PLI series displayed an extended position of the scaphoid on their initial PA and lateral radiographs, while 107 cases displayed a flexed, foreshortened position. The PA and lateral radiographs available in the REPLI literature displayed an extended position of the scaphoid, a lunotriquetral dissociation, and a dorsal dislocation of the capitate with respect to the lunate.

Discussion This study confirms our hypothesis. By contrast to the dorsal classic radial-sided pure ligamentous PLI pattern of scaphoid displacement (scaphoid flexed and foreshortened with scapholunate gap), the dorsal REPLI pattern displays an extended position of the scaphoid with scapholunate step-off and overlap rather than a gap. The combination of a lunotriquetral dissociation with a dorsal dislocation of the capitate from the lunate yet an extended position of the scaphoid with almost normal radioscaphoid relationships should raise a high suspicion for REPLI.
Group B Streptococcus Rectovaginal Colonization and Resistance Patterns in HIV-Positive Compared to HIV-Negative Pregnant Patients
Authors: Morgan John A. , Hankins Miriam E. , Callais Nicholas A. , Albritton Charles W. , Vanchiere John A. , Betcher Raymond E. , Lewis David F.
Published: November 2021

Objective The objective of our study is to determine if human immunodeficiency virus (HIV)-positive pregnant patients have a higher rate of group B streptococcus (GBS) rectovaginal colonization compared with HIV-negative pregnant patients.

Study Design Our study is a multi-site retrospective study performed at Ochsner Louisiana State University-Health Shreveport and Monroe campuses including patients who delivered between December 2011and June 2019. Rates of GBS rectovaginal colonization between HIV-positive pregnant patients were compared with a control group of HIV-negative patients. The control group was age and race matched in a 2:1 fashion. The primary outcome was to investigate rates of GBS rectovaginal colonization. Secondary outcomes included GBS culture antibiotic sensitivities, presence of GBS urinary tract infection, GBS positivity based on HIV viral load, and GBS positivity based on new vs established diagnosis of HIV. Continuous data were analyzed using an unpaired t-test, and categorical data were analyzed using a Chi-squared test. The probability level of <0.05 was set as statistically significant.

Results A total of 225 patients were included in the final analysis, 75 HIV-positive and 150 HIV-negative controls. Demographic differences were noted. HIV-positive patients were more likely to deliver preterm and were more likely to deliver via cesarean section. Our primary outcome showed no significant differences in incidence of GBS colonization between HIV-positive patients and control group (n = 31, 41.3% vs n = 46, 30.6%, p = 0.136). Antibiotic resistance patterns showed no significant difference between the two groups. There were no significant differences in GBS positivity based on HIV viral load.

Conclusion Our study does not show a statistically significant difference in the incidence of GBS colonization between HIV-positive patients and HIV-negative controls.

Key Points
Standardized Cesarean Risk Counseling with Induction: Impact on Racial Disparities in Birth Satisfaction
Authors: Hamm Rebecca F. , Srinivas Sindhu K. , Mccoy Jennifer , Morales Knashawn H. , Levine Lisa D.
Published: November 2021

Objective Our prior work demonstrated decreased birth satisfaction for Black women undergoing labor induction. We aimed to determine if implementation of standardized counseling around calculated cesarean risk during labor induction could reduce racial disparities in birth satisfaction.

Study Design We implemented use of a validated calculator that provides an individual cesarean risk score for women undergoing induction into routine care. This prospective cohort study compared satisfaction surveys for 6 months prior to implementation (preperiod: January 2018–June 2018) to 1 year after (postperiod: July 2018–June 2019). Women with full-term (≥37 weeks) singleton gestations with intact membranes and an unfavorable cervix undergoing induction were included. In the postperiod, providers counseled patients on individual cesarean risk at the beginning of induction using standardized scripts. This information was incorporated into care at patient–provider discretion. The validated 10-question Birth Satisfaction Scale-Revised (BSS-R) subdivided into three domains was administered throughout the study. Patients were determined to be “satisfied” or “unsatisfied” if total BSS-R score was above or below the median, respectively. In multivariable analysis, interaction terms evaluated the differential impact of the calculator on birth satisfaction by race (Black vs. non-Black women).

Results A total of 1,008 of 1,236 (81.6%) eligible women completed the BSS-R (preperiod: 330 [79.7%] versus postperiod: 678 [82.5%], p = 0.23), 63.8% of whom self-identified as Black. In the preperiod, Black women were 50% less likely to be satisfied than non-Black women, even when controlling for differences in parity (Black: 39.0% satisfied vs. non-Black: 53.9%, adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI]: 0.30–0.79). In the postperiod, there was no difference in satisfaction by race (Black: 43.7% satisfied vs. non-Black: 44.0%, aOR = 0.97. 95% CI: 0.71–1.33). Therefore, disparities in birth satisfaction were no longer present at postimplementation (interaction p = 0.03).

Conclusion Implementation of standardized counseling with a validated calculator to predict cesarean risk after labor induction is associated with a decrease in racial disparities in birth satisfaction.

Key Points
Defining a Strategy for Laboratory Evaluation with Expectant Management of Preeclampsia
Authors: Cozzi Gabriella D. , Blanchard Christina T. , Sanjanwala Aalok R. , Page Margaret R. , Kim Dhong-Jin , Tita Alan T. , Szychowski Jeff M. , Subramaniam Akila
Published: November 2021

Objective The objective of this study was to compare the frequency and timing of laboratory abnormalities and evaluate optimal laboratory testing strategies in women with preeclampsia (PE) undergoing expectant management.

Study Design Retrospective cohort study of women with inpatient expectant management of PE at ≥23 weeks at a tertiary center from 2015 to 2018 was conducted. Women ineligible for expectant management or with less than two laboratory sets (platelets, aspartate aminotransferase, and serum creatinine) before the decision to deliver were excluded. Women were categorized as per the American College of Obstetricians and Gynecologists' definitions by initial diagnosis: PE without severe features, superimposed preeclampsia (SiPE) without severe features, and their forms with severe features. The frequency and timing of laboratory abnormalities were compared across the four PE categories. Kaplan–Meier curves modeled time to a laboratory abnormality (event) with censoring for delivery and were compared using log-rank tests. Logistic regression analysis modeled the development of a laboratory abnormality as a function of testing time intervals (days) for each PE type. Receiver operating characteristic curves and areas under the curve (AUC) were calculated; optimal cut points were determined using the Liu method.

Results Among 636 women who met inclusion criteria, laboratory abnormalities were uncommon (6.3%). The median time to a laboratory abnormality among all women was ≤10 days, time being shortest in women with PE with severe features. Time to laboratory abnormality development did not differ significantly between the four PE groups (p = 0.36). Laboratory assessment intervals were most predictive for PE and SiPE with severe features (AUC = 0.87, AUC = 0.72). Optimal cutoffs were every 4 days for PE without severe features, 2 days for PE with severe features, 8 days for SiPE without severe features, and 3 days for SiPE with severe features.

Conclusion Most laboratory abnormalities in PE occur earlier and more frequently in those with severe features. Individual phenotypes should undergo serial evaluation based on this risk stratification.

Key Points
Global diffusion of three road safety policies, 1964–2015
Authors: Nazif-Munoz José Ignacio , Quesnel-Vallée Amélie , van den Berg Axel
Published: November 2021

Global convergence of public policies has been regarded as a defining feature of the late twentieth century. This study explores the generalizability of this thesis for three road safety measures: (i) road safety agencies; (ii) child restraint laws; and (iii) mandatory use of daytime running lights. This study analyzes cross-national longitudinal data using survival analysis for the years 1964–2015 in 181 countries. The first main finding is that only child restraint laws have globally converged; in contrast, the other two policies exhibit a fractured global convergence process, likely as the result of competing international and national forces. This finding may reflect the lack of necessary conditions, at the regional and national levels, required to accelerate the spread of policies globally, adding further nuance to the global convergence thesis. A second finding is that mechanisms of policy adoption, such as imitation/learning and competition, rather than coercion, explain more consistently global and regional convergence outcomes in the road safety realm. This finding reinforces the idea of specific elective affinities, when explaining why the diffusion of policies may or not result in convergence. Lastly, by recognizing fractured convergence processes, these results call for revisiting the global convergence thesis and reintegrating more consistently regional analyses into policy diffusion and convergence studies.
Perceptions, experiences and opportunities for occupational safety and health professionals arising out of the COVID-19 Pandemic
Authors: Gold David , Hughes Stuart , Thomas David
Published: November 2021

This study explored perceptions, experiences and opportunities for the occupational safety and health professional (OSHP) as a result of COVID-19. Using qualitative methods, interviews took place with OSHPs in two organisations to understand how their role developed during the pandemic. Additionally, seven focus groups were organised and met virtually, using the Zoom platform, each addressing a different topic identified by the researchers. Participants (n = 45) from 10 different countries were distributed among the focus groups. Topics were separated into four themes: impact on the workplace; the psychosocial dynamic; medical and health issues and occupational safety and health (OSH) issues. Results were subsequently divided into seven action categories and compared with the findings from the organisational interviews. Comparison pointed to an expanded role for the OSHP including business continuity, resilience and wellbeing in addition to assessing and controlling risks emerging during the pandemic. There is also the need for a means to adequately disseminate trustworthy information. Results indicated that there was no single ‘average’ role of the OSHP, demonstrating essential contributions as a member of the management team. Results also stressed that the pandemic carried three health-related co-morbidities, stress, Post-Traumatic Stress Disorder and burnout. Directions for future research included: the education of the OSHP to support a move away from compliance towards risk management; determining how mental health issues in organisations should be managed; expanded roles for OSHPs within business; and implications for professional bodies, membership institutions and academia in supporting the above-mentioned emerging roles.
Developing biomaterials to mediate the spatial distribution of integrins
Authors: Hu Xunwu , Zhang Ye
Published: November 2021

Innovation in material design to regulate cell behavior and function is one of the primary tasks in materials science. Integrins, a family of cell surface-adhesion receptors that mechanically connect the extracellular matrix (ECM) to the intracellular cytoskeleton, have long served as primary targets for the design of biomaterials because their activity is not only critical to a wide range of cell and tissue functions but also subject to very tight and complex regulations from the outside environment. To review the recent progress of material innovations targeting the spatial distribution of integrins, we first introduce the interaction mechanisms between cells and the ECM by highlighting integrin-based cell adhesions, describing how integrins respond to environmental stimuli, including variations in ligand presentation, mechanical cues, and topographical variations. Then, we overview the current development of soft materials in guiding cell behaviors and functions via spatial regulation of integrins. Finally, we discuss the current limitations of these technologies and the advances that may be achieved in the future. Undoubtedly, synthetic soft materials that mediate the spatial distribution of integrins play an important role in biomaterial innovations for advancing biomedical applications and addressing fundamental biological questions.
Extracting Lagrangian coherent structures in cardiovascular flows using Lagrangian descriptors
Authors: Darwish Ahmed , Norouzi Shahrzad , Di Labbio Giuseppe , Kadem Lyes
Published: November 2021

In cardiovascular flows, Lagrangian coherent structures have been used to explore the skeleton of blood transport. Revealing these transport barriers is instrumental to quantify the mixing and stagnation of blood as well as to highlight locations of elevated strain rate on blood elements. Nevertheless, the clinical use of Lagrangian coherent structures in cardiovascular flows is rarely reported due largely to its non-intuitive nature and computational expense. Here, we explore a recently developed approach called “Lagrangian descriptors,” which quantifies the finite time Euclidean arc length of Lagrangian trajectories released from a grid of initial positions. Moreover, the finite time arc lengths of a set of trajectories capture signatures of Lagrangian coherent structures computed from the same initial condition. Remarkably, the Lagrangian descriptors approach has the most rapid computational performance among all its Lagrangian counterparts. In this work, we explore the application of Lagrangian descriptors for the first time in cardiovascular flows. For this purpose, we consider two in vitro flow models studied previously by our group: flow in an abdominal aortic aneurysm and that in a healthy left ventricle. In particular, we will demonstrate the ability of the Lagrangian descriptors approach to reveal Lagrangian coherent structures computed via the classical geometrical approach, though at a significantly reduced computational cost.
Deformed explicitly correlated Gaussians
Authors: Beutel Matthew , Ahrens Alexander , Huang Chenhang , Suzuki Yasuyuki , Varga Kálmán
Published: November 2021

Deformed explicitly correlated Gaussian (DECG) basis functions are introduced, and their matrix elements are calculated. All matrix elements can be calculated analytically in a closed form, except the Coulomb one, which has to be approximated by a Gaussian expansion. The DECG basis functions can be used to solve problems with nonspherical potentials. One example of such potential is the dipole self-interaction term in the Pauli–Fierz Hamiltonian. Examples are presented showing the accuracy and necessity of deformed Gaussian basis functions to accurately solve light–matter coupled systems in cavity QED.
1D photonic crystal direct bandgap GeSn-on-insulator laser
Authors: Joo Hyo-Jun , Kim Youngmin , Burt Daniel , Jung Yongduck , Zhang Lin , Chen Melvina , Parluhutan Samuel Jior , Kang Dong-Ho , Lee Chulwon , Assali Simone , Ikonic Zoran , Moutanabbir Oussama , Cho Yong-Hoon , Tan Chuan Seng , Nam Donguk
Published: November 2021

GeSn alloys have been regarded as a potential lasing material for a complementary metal–oxide–semiconductor-compatible light source. Despite their remarkable progress, all GeSn lasers reported to date have large device footprints and active areas, which prevent the realization of densely integrated on-chip lasers operating at low power consumption. Here, we present a 1D photonic crystal nanobeam with a very small device footprint of 7 μm2 and a compact active area of ∼1.2 μm2 on a high-quality GeSn-on-insulator substrate. We also report that the improved directness in our strain-free nanobeam lasers leads to a lower threshold density and a higher operating temperature compared to the compressive strained counterparts. The threshold density of the strain-free nanobeam laser is ∼18.2 kW cm−2 at 4 K, which is significantly lower than that of the unreleased nanobeam laser (∼38.4 kW cm−2 at 4 K). Lasing in the strain-free nanobeam device persists up to 90 K, whereas the unreleased nanobeam shows quenching of lasing at a temperature of 70 K. Our demonstration offers an avenue toward developing practical group-IV light sources with high-density integration and low power consumption.
First-principles study of two-dimensional gallium-nitrides on van der Waals epitaxial substrate
Authors: Yayama Tomoe , Lu Anh Khoa Augustin , Morishita Tetsuya , Nakanishi Takeshi
Published: November 2021

The structural and electronic properties of two-dimensional gallium nitrides (2D GaNs) on a van der Waals (vdW) epitaxial substrate are investigated using first-principles calculations. We show that the structures and electronic properties of mono- and bilayer GaN are hardly affected when deposited on the vdW substrate comprising a graphene sheet placed on the GaN(0001) bulk surface. A weak attractive interaction is found to work between the 2D GaNs and vdW substrate, which is still sufficient to maintain the 2D GaNs on the substrate and could also be exploited to control their stability. The present findings demonstrate that the vdW substrate is propitious to grow and hold the 2D GaNs without altering their intrinsic properties, in contrast to previously examined metal substrates.
Strain engineering of quasi-1D layered TiS3 nanosheets toward giant anisotropic Raman and piezoresistance responses
Authors: Qin Jing-Kai , Sun Hai-Lin , Su Tong , Zhao Weiwei , Zhen Liang , Chai Yang , Xu Cheng-Yan
Published: November 2021

Quasi-one-dimensional layered TiS3 nanosheets possess highly anisotropic physical properties. Herein, we reported the anisotropic strain response of Raman and the piezoresistance effect in layered TiS3 nanosheets. An attractive Grüneisen parameter (γm) of 5.82 was achieved for AgIII mode in the b-axis strained TiS3 nanosheet, while a negligible value of γm was obtained when the strain is applied along the a-axis direction. We also revealed the opposite piezoresistive effect with strains applied along the two principal axes, demonstrating a gauge factor ratio of approximately −1:3.2. The giant anisotropy is attributed to the strain modulated bandgap, which was further confirmed by density functional theory calculations.
Detailed investigation of subgrid scale models in large-eddy simulation using high aspect-ratio grid spacing
Authors: Abe Ken-ichi
Published: November 2021

In large eddy simulation (LES), we generally use information of the grid width in representing a filter width (Δ) to evaluate a subgrid scale (SGS) model. In practical applications, however, the grid widths are largely different in the streamwise and cross-streamwise directions, resulting in grid cells having high aspect ratios. In such a case, we often adopt the cube root of the grid-cell volume for the filter width; i.e., Δ=(ΔxΔyΔz)1/3 in the Cartesian grid system. Although this has been regarded as a standard way to determine the filter width, its superiority over other strategies, such as using the maximum width in all directions (i.e., Δ=max(Δx,Δy,Δz)), has not always been made clear. In this paper, to investigate the effect of the definition of a filter width on the prediction accuracy of an SGS model, we report on a priori tests of several SGS models using highly resolved LES data of a backward-facing step flow. We focus particularly on the model performance in the shear layer downstream of a step, where there exists a strong velocity gradient and the aspect ratio of a grid cell is high despite the region being far from wall surfaces. This investigation enables us to distinguish the effect of the grid aspect ratio from that of near-wall damping. We make the important finding that the cube root of a grid-cell volume is not always appropriate for the filter width. To evaluate an SGS model properly, the effect of a grid width in one direction much smaller than in other directions must be excluded in determining the filter width.
Turbulent characteristics and energy transfer in the far field of active-grid turbulence
Authors: Zheng Y. , Nagata K. , Watanabe T.
Published: November 2021

Turbulent characteristics in the far field of active-grid turbulence have been investigated through wind tunnel experiments using hot-wire anemometry. Two forcing protocols are employed following previous studies: one is the double-random mode and the other is the open mode with the grid remaining static with minimum blockage. The integral length scale L for the double-random modes slightly decreases with streamwise distance in the far field as observed in the near field of the active-grid turbulence. The nondimensional dissipation rate Cε for the double-random modes is around 0.5. This asymptotic value is different from those reported in previous active-grid turbulence experiments and could be nonuniversal. The equilibrium scaling L/λ=CεReλ/15 (λ is the Taylor microscale and Reλ is the turbulent Reynolds number) with a constant Cε is established in the far field of the double-random modes regardless of active-grid motions. The sum of production and destruction terms in the enstrophy budget equation for homogeneous and isotropic turbulence S+2G/Reλ (S is the skewness of the longitudinal velocity derivative and G is the destruction coefficient) is proportional to Reλ−1 and close to zero in the present active-grid turbulence, suggesting that the equilibrium scaling is possibly related to the balance between the production and destruction of the enstrophy.
An efficient implementation of the NEVPT2 and CASPT2 methods avoiding higher-order density matrices
Authors: Kollmar Christian , Sivalingam Kantharuban , Guo Yang , Neese Frank
Published: November 2021

A factorization of the matrix elements of the Dyall Hamiltonian in N-electron valence state perturbation theory allowing their evaluation with a computational effort comparable to the one needed for the construction of the third-order reduced density matrix at the most is presented. Thus, the computational bottleneck arising from explicit evaluation of the fourth-order density matrix is avoided. It is also shown that the residual terms arising in the case of an approximate complete active space configuration interaction solution and containing even the fifth-order density matrix for two excitation classes can be evaluated with little additional effort by choosing again a favorable factorization of the corresponding matrix elements. An analogous argument is also provided for avoiding the fourth-order density matrix in complete active space second-order perturbation theory. Practical calculations indicate that such an approach leads to a considerable gain in computational efficiency without any compromise in numerical accuracy or stability.
Different perspectives on predicting the thermoacoustic energy conversion response in a Rijke tube
Authors: Shelton Cody M. , Majdalani Joseph
Published: November 2021

In this work, six different perspectives on characterizing the thermoacoustic field in an open-ended Rijke tube are considered and discussed. These begin with a three-pronged approach consisting of theoretical, experimental, and numerical investigations of the Rijke tube's time-dependent field. It is followed by a discussion of effective techniques that rely on either Green's function or differential equation models. Finally, a perturbation expansion is introduced that leverages a naturally occurring small parameter in the open tube configuration. This approach is shown to produce accurate predictions of pressure modal shapes and frequencies for an arbitrary specified temperature distribution. It also leads to a set of linear partial differential equations that can be solved in conjunction with a Green's function expression for the thermoacoustic pressure, velocity, and heat oscillations. In this study, the underlying framework is presented and evaluated for the pressure disturbance only. Another fundamental result includes a similarity parameter, coined the Rijke number, which plays an essential role in driving thermoacoustic oscillations, namely, by relating heat-flux fluctuations to the acoustic velocity and pressure. In this context, we find that the peak value of the energy-flux vector modulus, which stands for the modular product of acoustic velocity and pressure, does indeed occur at the heat source location and increases with the heat power input.
Large temperature difference heat dominated flow simulations using a pressure-based lattice Boltzmann method with mass correction
Authors: Wang Guanxiong , Xu Lincheng , Serre Eric , Sagaut Pierre
Published: November 2021

This paper addresses simulation of heat dominated compressible flows in a closed cavity using a pressure-based lattice Boltzmann (LB) method, in which thermal effects are modeled by applying a pressure-featured zero-order moment of distribution functions. A focus is made on the conservation of mass at boundary nodes, which is a challenging issue that significantly complicated by the density-decoupled zero-order moment here. The mass leakage at boundary nodes is mathematically quantified, which enables an efficient local mass correction scheme. The performance of this solver is assessed by simulating buoyancy-driven flows in a closed deferentially heated cavity with large temperature differences (non-Boussinesq) at Rayleigh numbers ranging from 103 to 107. Simulations show that mass leakage at solid walls in such configurations is a critical issue to obtain reliable solutions, and it eventually leads to simulations overflow when the cavity is inclined. The proposed mass correction scheme is, however, shown to be effective to control the mass leakage and get accurate solutions. Thus, associated with the proposed mass conservation scheme, the pressure-based LB method becomes reliable to study natural convection dominated flows at large temperature differences in closed geometries with mesh aligned boundaries or not.
Structural phase transition and giant negative thermal expansion in pyrophosphate Zn2–xMgxP2O7
Authors: Kadowaki Y. , Kasugai R. , Yokoyama Y. , Katayama N. , Okamoto Y. , Takenaka K.
Published: November 2021

By tuning the structural phase transition in Zn2–xMgxP2O7, large negative thermal expansion (NTE) was achieved at room temperature. An earlier report described that Zn2P2O7 undergoes a structural phase transition at 405 K, accompanied by volume contraction of 1.8% on heating. Results showed that as Mg doping proceeds, the transition temperature decreases. Also, the volume change becomes gradual with respect to temperature. Particularly, Zn1.6Mg0.4P2O7 has a large negative coefficient of linear thermal expansion αL of −60 ppm/K at 280–350 K. Structural analysis using synchrotron radiation revealed that this dilatometric NTE is almost identical to that of crystallographic unit cells, indicating less dominant structural effects on NTE. We also verified thermal expansion compensation capabilities of powdered Zn1.6Mg0.4P2O7 by evaluating the thermal expansion of the epoxy resin matrix composites. The present phosphates are promising for use as practical thermal expansion compensators because they are free of toxic or expensive elements and can be fabricated in air using the simple solid-state reaction method.
Arbitrarily accurate quantum alchemy
Authors: von Rudorff Guido Falk
Published: November 2021

Doping compounds can be considered a perturbation to the nuclear charges in a molecular Hamiltonian. Expansions of this perturbation in a Taylor series, i.e., quantum alchemy, have been used in the literature to assess millions of derivative compounds at once rather than enumerating them in costly quantum chemistry calculations. So far, it was unclear whether this series even converges for small molecules, whether it can be used for geometry relaxation, and how strong this perturbation may be to still obtain convergent numbers. This work provides numerical evidence that this expansion converges and recovers the self-consistent energy of Hartree–Fock calculations. The convergence radius of this expansion is quantified for dimer examples and systematically evaluated for different basis sets, allowing for estimates of the chemical space that can be covered by perturbing one reference calculation alone. Besides electronic energy, convergence is shown for density matrix elements, molecular orbital energies, and density profiles, even for large changes in electronic structure, e.g., transforming He3 into H6. Subsequently, mixed alchemical and spatial derivatives are used to relax H2 from the electronic structure of He alone, highlighting a path to spatially relaxed quantum alchemy. Finally, the underlying code that allows for arbitrarily accurate evaluation of restricted Hartree–Fock energies and arbitrary order derivatives is made available to support future method development.
Quantitative Imaging in Oncologic PET
Authors: Wahl Richard L. , Lodge Martin A.
Published: November 2021

This chapter highlights the fundamentals of positron emission tomography (PET) imaging, highlighting the steps needed to secure quantitative image data from PET scans, and highlights some of the challenges, especially for detecting and quantifying small lesions and for lesion assessment across differing performance sites and scanners. An extensive review of the role of quantitative PET imaging to provide valuable prognostic and staging data is included. Examples of the advantages of quantitative imaging (QI), notably the ability to detect small, but biologically significant, changes in tumor tracer uptake related to therapy and the improved reliability of QI versus qualitative imaging alone are reviewed. Tools to extract QI data from PET scans easily and more rapidly are highlighted, and an extensive review of the uses of quantitative PET in assessing treatment response is provided. Extraction of simple to more complex QI data from PET can be used to provide a non-invasive phenotyping of patients with cancer, which is increasingly used to guide precision medicine approaches to cancer.
Quantitative Imaging in Computed Tomography
Authors: McNitt-Gray Michael
Published: November 2021

This chapter covers the use of computed tomography (CT) in quantitative imaging (QI). The use of CT in clinical practice and its widespread use in many clinical applications are described, and a short history of QI applications is presented. Some of these have been in place for 30 years. A full understanding of the use of CT as a clinical QI measurement system requires knowledge of some of the design features of modern CT scanners and their capabilities, including the number of detector rows, the design of those detectors, the number and characteristics of the x-ray source, and filtration schemes. Also important are issues related to operational parameters of CT scanning, including acquisition and reconstruction parameters, and their effects on QI and radiomic feature sensitivity. The chapter concludes with a brief discussion of standardization, with regard to the use of CT in QI applications.
Paying for value: options for value-based payment reform in Australia
Authors: Wise Sarah , Hall Jane , Haywood Philip , Khana Nikita , Hossain Lutfun , van Gool Kees
Published: November 2021

Value-based health care has gained increasing prominence among funders and providers in efforts to improve the outcomes important to patients relative to the resources used to deliver care. In Australia, the value-based healthcare agenda has focused on reducing the use of ‘low-value’ interventions, redesigning models of care to improve integration between providers and increasing the use of patient-reported measures to drive improvement; all have occurred within existing payment structures. In this paper we describe options for value-based payment reform and highlight two challenges critical for success: attributing financial risk fairly and organisational structures. What is known about the topic? ‘Fee for service’ is the dominant payment method in Australia and creates incentives to increase service volume, rewarding inputs rather than improvements in longer-term health outcomes. There is increasing recognition that payment reform is needed to support the shift to value-based health care in Australia. What does this paper add? This paper describes the three main options for value-based payment reform: episode-based bundled payments chronic condition bundled payments and comprehensive capitation payments. Each involves some degree of funds pooling, and the shifting of risk from the funder to provider to stimulate the more efficient use of resources. What are the implications for practitioners? We conclude that local hospital authorities in the states, private health insurers and primary health networks could implement reform as payment holders, but that capacity development in coordination and risk adjustment will be required. Successful implementation of payment reform will also require investment in data collection and information technology to track patients’ care and measure outcomes and costs.
Pathophysiological interplay between
O
-GlcNAc transferase and the Machado–Joseph disease protein ataxin-3
Authors: Pereira Sena Priscila , Weber Jonasz J. , Watchon Maxinne , Robinson Katherine J. , Wassouf Zinah , Hauser Stefan , Helm Jacob , Abeditashi Mahkameh , Schmidt Jana , Hübener-Schmid Jeannette , Schöls Ludger , Laird Angela S. , Riess Olaf , Schmidt Thorsten
Published: November 2021

Significance

Machado–Joseph disease (MJD) is an incurable neurodegenerative disorder caused by a mutation in the ataxin-3 protein, which becomes toxic and induces cerebellar degeneration and motor impairments. Disturbances in the protein modification
O
-GlcNAcylation, catalyzed by the enzyme
O
-GlcNAc transferase (OGT), have been linked to neurodegeneration, but its potential involvement in MJD remains elusive. By analyzing MJD cells and animal models, we demonstrate altered levels of OGT in MJD, further identifying this enzyme as a substrate of ataxin-3. Targeting OGT reduced ataxin-3 toxicity, improving the motor phenotype of an MJD animal model. Our results unveiled a physiological interplay between ataxin-3 and OGT, highlighting OGT as a potential therapeutic target in this deadly condition.
THCz: Small molecules with antimicrobial activity that block cell wall lipid intermediates
Authors: Reithuber Elisabeth , Wixe Torbjörn , Ludwig Kevin C. , Müller Anna , Uvell Hanna , Grein Fabian , Lindgren Anders E. G. , Muschiol Sandra , Nannapaneni Priyanka , Eriksson Anna , Schneider Tanja , Normark Staffan , Henriques-Normark Birgitta , Almqvist Fredrik , Mellroth Peter
Published: November 2021

Significance

Considering the alarming emergence of resistance to most antibiotics and the need for new antibiotics, the finding here of a small-molecule class, THCz, that displayed bactericidal activity against gram-positive and selected gram-negative bacteria, is of the greatest importance. We found that THCz target the cell envelope synthesis and can easily be synthesized and modified, and resistance did not readily develop in vitro. Thus, THCz are promising scaffolds for development of bacterial cell wall inhibitors.
GRACE Follow-On revealed Bangladesh was flooded early in the 2020 monsoon season due to premature soil saturation
Authors: Han Shin-Chan , Ghobadi-Far Khosro , Yeo In-Young , McCullough Christopher M. , Lee Eunjee , Sauber Jeanne
Published: November 2021

Significance

We report how much water flooded Bangladesh during the 2020 wet monsoon period and explain why the 2020 monsoonal flooding started unusually early, lasted longer, and was more severe than flooding in other years. The laser-ranging instrument on GRACE Follow-On spacecraft detected the size and timing of this unusual flooding event, and we found that the 2020 flooding was worsened by soils saturated earlier than usual by a premonsoon cyclone. We highlight the importance of including the antecedent soil moisture condition in the present flood forecasting and warning practices in Bangladesh.
Handedness and its genetic influences are associated with structural asymmetries of the cerebral cortex in 31,864 individuals
Authors: Sha Zhiqiang , Pepe Antonietta , Schijven Dick , Carrión-Castillo Amaia , Roe James M. , Westerhausen René , Joliot Marc , Fisher Simon E. , Crivello Fabrice , Francks Clyde
Published: November 2021

Significance

Left-handedness occurs in roughly 10% of people, but whether it involves altered brain anatomy has remained unclear. We measured left to right asymmetry of the cerebral cortex in 28,802 right-handers and 3,062 left-handers. There were small average differences between the two handedness groups in brain regions important for hand control, language, vision, and working memory. Genetic influences on handedness were associated with some of these brain asymmetries, especially of language-related regions. This suggests links between handedness and language during human development and evolution. One implicated gene is
NME7
, which also affects placement of the visceral organs (heart, liver, etc.) on the left to right body axis—a possible connection between brain and body asymmetries in embryonic development.