bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relating Bond Strength and Nature to the Thermodynamic Stability of Hypervalent Togni‐Type Iodine Compounds
Authors: Oliveira Vytor Pinheiro , Marcial Bruna Luana , Machado Francisco B. C. , Kraka Elfi 
Published: August 2021

AbstractThe bond strength and nature of a set of 32 Togni‐like reagents have been investigated at the M062X/def2‐TZVP(D) level of theory in acetonitrile described with the SMD continuum solvent model, to rationalize the main factors responsible for their thermodynamic stability in different conformations, and trifluoromethylation capabilities. For the assessment of bond strength, we utilized local stretching force constants and associated bond strength orders, complemented with local features of the electron density to access the nature of the bonds. Bond dissociation energies varied from 31.6 to 79.9 kcal/mol depending on the polarizing power of the ligand trans to CF3. Based on the analysis of the Laplacian of the density, we propose that the charge‐shift bond character plays an important role in the stability of the molecules studied, especially for those containing I−O bonds. New insights on the trans influence and on possible ways to fine‐tune the stability of these reagents are provided.
Amorphous Molecular Materials for Directed Supercontinuum Generation
Authors: Dehnen Stefanie , Schreiner Peter R. , Chatterjee Sangam , Volz Kerstin , Rosemann Nils W. , Pilgrim Wolf‐Christian , Mollenhauer Doreen , Sanna Simone 
Published: August 2021

AbstractMolecular compounds of the general formula [(RT)4E6] (R=organic or organometallic substituent; T=C, Si, Ge, Sn; E=CH2, S, Se), hence adamantane derivatives and inorganic‐organic hybrid compounds based on a heteroadamantane structure exhibit a non‐linear optical response upon radiation with a continuous‐wave near‐infrared laser. The effect depends on the compounds’ habitus, which itself depends on the elemental composition of the cluster core, and on the nature of the organic substituents. A combination of these parameters that cause the material to be intrinsically amorphous leads to supercontinuum generation and thus to the emission of a broad spectrum, potentially appearing as white light. Notably, the emission essentially retains the driving laser's directionality. For crystalline samples, second harmonic generation is observed instead, which points to a close relationship of the optical properties and the intermolecular order. Variation of R, T, and E allows further fine‐tuning of the emitted spectra. We present all studies made in regards to these effects and our overarching conclusions derived from them.
Elevated serum triglyceride levels at first prenatal visit is associated with the development of gestational diabetes mellitus
Authors: Hu Ming , Gu Xiaohan , Niu Yang , Lu Wenyi , Huang Cuihua , Tang Qingya , Wu Jiang 
Published: August 2021

AbstractAimsWhile several studies have indicated that maternal serum lipid profiles are associated with the development of gestational diabetes mellitus (GDM), the results have been inconsistent. This study aimed to explore the relationship between maternal lipids profiles at first prenatal visit and GDM and determine the optimal cut‐off values of possible trimester‐specific variables in predicting GDM.Materials and MethodsClinical data of women with singleton pregnancies who delivered in Xinhua Hospital between January 2016 and January 2017 were collected from electronic databases. Multivariate logistic regression was used to determine the potential risk factors of GDM (specific to the trimester at first prenatal visit), including age, body mass index (BMI), and serum lipid profile and fasting plasma glucose (FPG) levels. The receiver operating characteristic (ROC) curve analysis was performed to determine the cut‐off values of significant variables.ResultsAmong the 2191 pregnant women included, 315 (14.38%) were diagnosed with GDM. Of these, 880 (40.16%) had their first prenatal visit before 14 gestational weeks. Univariate and multivariate analyses showed that both FPG and triglyceride (TG) levels in the first and second trimesters were associated with a high risk of GDM (p < 0.05). The ROC curve showed that serum TG levels >1.235 mmol/L and >1.525 mmol/L in the first and second trimesters, respectively, were significantly associated with the development of GDM (p < 0.05).ConclusionsTG levels at first prenatal visit is associated with GDM risk. Different TG cut‐off values should be applied in the different trimesters of pregnancy for GDM screening.
Esophageal achalasia diagnosed in people previously diagnosed with an eating disorder: Epidemiological study using record‐linkage
Authors: Goldacre Michael , Benians Robin , Goldacre Raph 
Published: August 2021

AbstractObjectiveOccasionally, patients with eating disorders have been subsequently diagnosed with esophageal achalasia. We sought to establish whether eating disorders and achalasia coexisted more often than expected by chance alone.MethodNational record‐linkage study of hospital inpatients in England, between 2001 and 2017. Use of Cox proportional hazards to compare the occurrence of achalasia in cohorts of people with or without anorexia nervosa (AN), and with or without bulimia nervosa (BN), with adjustment of the comparisons for such confounders as age, sex, and year of admission.ResultsThere were 18,500 people in the AN cohort, 11,300 in the BN cohort, and 8.7 million in the comparison cohort. The Cox regression hazard ratio, comparing the AN cohort with the reference cohort, was 3.4 (95% confidence interval 1.8–6.3) and that in the BN cohort was 4.2 (2.2–8.2).DiscussionAN and achalasia, and BN and achalasia, were diagnosed in the same individuals, more often than expected by chance. Clinicians should be aware of the possible associations with achalasia because the treatment of eating disorders and achalasia is different.
What is winter? Modeling spatial variation in bat host traits and hibernation and their implications for overwintering energetics
Authors: Hranac C. Reed , Haase Catherine G. , Fuller Nathan W. , McClure Meredith L. , Marshall Jonathan C. , Lausen Cori L. , McGuire Liam P. , Olson Sarah H. , Hayman David T. S. 
Published: August 2021

AbstractWhite‐nose syndrome (WNS) has decimated hibernating bat populations across eastern and central North America for over a decade. Disease severity is driven by the interaction between bat characteristics, the cold‐loving fungal agent, and the hibernation environment. While we further improve hibernation energetics models, we have yet to examine how spatial heterogeneity in host traits is linked to survival in this disease system. Here, we develop predictive spatial models of body mass for the little brown myotis (Myotis lucifugus) and reassess previous definitions of the duration of hibernation of this species. Using data from published literature, public databases, local experts, and our own fieldwork, we fit a series of generalized linear models with hypothesized abiotic drivers to create distribution‐wide predictions of prehibernation body fat and hibernation duration. Our results provide improved estimations of hibernation duration and identify a scaling relationship between body mass and body fat; this relationship allows for the first continuous estimates of prehibernation body mass and fat across the species' distribution. We used these results to inform a hibernation energetic model to create spatially varying fat use estimates for M. lucifugus. These results predict WNS mortality of M. lucifugus populations in western North America may be comparable to the substantial die‐off observed in eastern and central populations.
Influence of the large‐Z effect during contact between butterfly sister species
Authors: Nelson Erik D. , Cong Qian , Grishin Nick V. 
Published: August 2021

AbstractRecently diverged butterfly populations in North America have been found to exhibit high levels of divergence on the Z chromosome relative to autosomes, as measured by fixation index, . The pattern of divergence appears to result from accumulation of incompatible alleles, obstructing introgression on the Z chromosome in hybrids (i.e., the large‐Z effect); however, it is unknown whether this mechanism is sufficient to explain the data. Here, we simulate the effects of hybrid incompatibility on interbreeding butterfly populations using a model in which populations accumulate cross‐incompatible alleles in allopatry prior to contact. We compute statistics for introgression and population divergence during contact between model populations and compare our results to those for 15 pairs of butterfly species interbreeding along a suture zone in central Texas. Time scales for allopatry and contact in the model are scaled to glacial and interglacial periods during which real populations evolved in isolation and contact. We find that the data for butterflies are explained well by an otherwise neutral model under slow fusion conditions. In particular, levels of divergence on the Z chromosome increase when interacting clusters of genes are closely linked, consistent with clusters of functionally related genes in butterfly genomes.
Tree‐ring stable isotopes and radiocarbon reveal pre‐ and post‐eruption effects of volcanic processes on trees on Mt. Etna (Sicily, Italy)
Authors: Seiler Ruedi , Hajdas Irka , Saurer Matthias , Houlié Nicolas , D'Arrigo Rosanne , Kirchner James W. , Cherubini Paolo 
Published: August 2021

AbstractEarly detection of volcanic eruptions is of major importance for protecting human life. Ground deformation and changes in seismicity, geochemistry, petrology, and gravimetry are used to assess volcanic activity before eruptions. Studies on Mt. Etna (Italy) have demonstrated that vegetation can be affected by pre‐eruptive activity before the onset of eruptions. During two consecutive years before Mt. Etna's 2002/2003 flank eruption, enhanced vegetation index (NDVI) values were detected along a distinct line which later developed into an eruptive fissure. However, the mechanisms by which volcanic activity can lead to changes in pre‐eruption tree growth processes are still not well understood. We analysed δ13C, δ18O and14C in the rings of the survived trees growing near to the line where the pre‐eruptive increase in NDVI was observed in order to evaluate whether the uptake of water vapour or fossil volcanic CO2could have contributed to the enhanced NDVI. We found a dramatic decrease in δ18O in tree rings formed before 2002/2003 in trees close to the eruption fissure, suggesting uptake of volcanic water by trees during pre‐eruptive magma degassing. Moist conditions caused by outgassing of ascending magma may also have led to an observed reduction in tree‐ring δ13C following the eruption. Furthermore, only ambiguous evidence for tree uptake of degassed CO2was found. Our results suggest that additional soil water condensed from degassed water vapour may have promoted photosynthesis, explaining local increases in NDVI before the 2002/2003 Mt. Etna flank eruption. Tree‐ring oxygen stable isotopes might be used as indicators of past volcanic eruptions.
Blood pressure visit‐to‐visit variability and outcomes in patients with heart failure with preserved ejection fraction
Authors: Zhang Qi , Zhou Bingyang , Ma Yu , Hu Yuecheng , Li Ximing , Cong Hongliang 
Published: August 2021

AbstractAimsPrevious studies report that blood pressure (BP) variability is associated with increased risk of adverse outcomes in patients diagnosed with cardiovascular disease. However, studies have not fully explored this association in patients with heart failure with preserved ejection fraction (HFpEF). This study sought to explore the association between visit‐to‐visit variability (VVV) of BP and clinical outcomes in patients with HFpEF.Methods and resultsA total of 1988 patients (mean age of 67.73 ± 9.22, 51.7% female) from the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial were included in this study. BP‐VVV was determined by standard deviation (SD) of mean systolic BP (SBP‐SD) from six measurements (baseline and months 1, 2, 4, 8, and 12) during the first 12 months after randomization. Mean on‐treatment SBP during the first 12 months was 127.77 ± 10.42 mmHg, and the median of SBP‐SD was 8.15 mmHg. A total of 192 (9.7%) patients met the primary outcome during the subsequent median follow‐up of 35.16 months, including a composite of cardiovascular death, heart failure hospitalization, or aborted cardiac arrest. Multiple Cox regression analysis showed that SBP‐SD was independently associated with the increased risk of the primary outcome after adjusting for age, gender, method of BP measurement, treatment, renal function and common co‐morbidities, and the mean SBP during the first 12 months [hazard ratio (HR) for fourth vs. first quartile, 1.63; 95% confidence interval (CI), 1.07–2.49; P = 0.024]. Analysis showed that SBP‐SD as continuous variable was associated with a 23% increase in the risk of primary outcome (HR 1.23, 95% CI 1.06–1.43; P = 0.006).ConclusionsThe findings of the current study show that high SBP‐VVV in patients with HFpEF is associated with an increased risk of adverse outcomes independent of the mean on‐treatment SBP.
Coordination Chemistry and Sensing Properties Towards Anions and Metal Ions of a Simple Fluorescent Urea
Authors: Montis Riccardo , Aragoni M. Carla , Arca Massimiliano , Coles Simon J. , Lippolis Vito , Milia Jessica , Orton James B. , Pala Laura , Picci Giacomo , Pivetta Tiziana , Caltagirone Claudia 
Published: August 2021

AbstractThe coordination and sensing properties towards anions and transition metal ions of the simple novel fluorescent urea 1‐(2‐aminophenyl)‐3‐(naphthalen‐1)‐yl)urea (L) were investigated in solution, and in the solid state. An electron donating amine group in the molecular skeleton of L decreased the acidity of the urea NHs that are usually deprotonated by basic anions and allowed for a good degree of affinity towards fluoride in DMSO‐d6‐0.5 %H2O. Moreover, the amine moiety acted as a further binding group for metal ions. Indeed, L was able to bind Zn2+ both in solution and in the solid state, and to respond to the presence of this metal ion in MeCN with an enhancement of the fluorescence emission. Although solution studies evidenced the formation of a 1 : 1 complex of L with Zn2+, complexes with a 2 : 1 ligand‐to‐metal stoichiometry were isolated in the solid state. DFT calculations helped to clarify the stability reasons behind these results.
Authenticity assessment of dairy products by capillary electrophoresis
Authors: Masci Maurizio , Zoani Claudia , Nevigato Teresina , Turrini Aida , Jasionowska Renata , Caproni Roberto , Ratini Patrizia 
Published: August 2021

AbstractMilk and derivatives are a very important part in the diet of the world population. Products from goat, buffalo, and sheep species have a greater economic value than the cow ones, therefore, authenticity frauds by improperly adding cow's milk occur frequently: dairy products are among the seven more attractive foods for adulteration. Milk from each of the above‐cited animal species has its own definite profile of whey proteins (variants of α‐lactalbumin and β‐lactoglobulin) and its definite profile of caseins (variants of αS1‐, αS2‐, β‐, and κ‐casein). Such proteins can be usefully exploited as markers of authenticity by using capillary electrophoresis which is the technique of choice for the analysis of proteins. Due to the multiple adjustable parameters that are unknown to other analytical techniques, capillary electrophoresis is able to detect frauds in milk mixtures and cheese with little use of solvents, fast analysis time, and ease of operation. This makes it attractive and competitive for routine checks that are very important to fight the adulteration market. Advantages and limitations are discussed.
Quantized precoding and companding schemes for PAPR reduction in UFMC‐based massive MIMO downlink systems
Authors: Chintala Vijaya Durga , Sundru Anuradha 
Published: August 2021

AbstractUniversal‐filtered multi‐carrier (UFMC) is a promising waveform technology, which inherits the robustness of FBMC and simplicity of OFDM. In this article, the UFMC waveform is combined with the massive multi‐user multiple‐input and multiple‐output (MU‐MIMO) technology to meet the desired needs of future wireless networks. In order to eliminate MU interference (MUI), the precoding is essential in massive MU‐MIMO downlink. However, the transmitted signals produced by the precoders have high peak‐to‐average power ratio (PAPR), thus resulting in reduction of power efficiency of the system. Hence, this article proposes the quantized MU precoding and companding schemes to increase the power efficiency of UFMC‐based massive MU‐MIMO downlink systems. A nonlinear quantized precoder called squared‐infinity norm Douglas‐Rachford splitting (SQUID), which generates signals with constant envelope, is proposed. The proposed SQUID precoder reduces the power consumption and MUI of UFMC‐based massive MU‐MIMO systems. Moreover, a piecewise linear companding (PLC) scheme, which further reduces the PAPR by employing two threshold values and one companding parameter, is also proposed. The simulation results confirm that the proposed UFMC‐based massive MU‐MIMO with quantized nonlinear SQUID precoding provides better performance than quantized linear precoders. Besides, the proposed system with the PLC scheme offers better PAPR reduction of 4.5 dB when compared with linear nonsymmetrical transform and ‐law schemes.
Optogenetic‐mediated cardiovascular differentiation and patterning of human pluripotent stem cells
Authors: Hellwarth Peter B. , Chang Yun , Das Arundhati , Liang Po‐Yu , Lian Xiaojun , Repina Nicole A. , Bao Xiaoping 
Published: August 2021

AbstractPrecise spatial and temporal regulation of dynamic morphogen signals during human development governs the processes of cell proliferation, migration, and differentiation to form organized tissues and organs. Tissue patterns spontaneously emerge in various human pluripotent stem cell (hPSC) models. However, the lack of molecular methods for precise control over signal dynamics limits the reproducible production of tissue patterns and a mechanistic understanding of self‐organization. We recently implemented an optogenetic‐based OptoWnt platform for light‐controllable regulation of Wnt/β‐catenin signaling in hPSCs for in vitro studies. Using engineered illumination devices to generate light patterns and thus precise spatiotemporal control over Wnt activation, here we triggered spatially organized transcriptional changes and mesoderm differentiation of hPSCs. In this way, the OptoWnt system enabled robust endothelial cell differentiation and cardiac tissue patterning in vitro. Our results demonstrate that spatiotemporal regulation of signaling pathways via synthetic OptoWnt enables instructive stem cell fate engineering and tissue patterning.
White matter degeneration revealed by fiber‐specific analysis relates to recovery of hand function after stroke
Authors: Cheng Bastian , Petersen Marvin , Schulz Robert , Boenstrup Marlene , Krawinkel Lutz , Gerloff Christian , Thomalla Götz 
Published: August 2021

AbstractRecent developments of higher‐order diffusion‐weighted imaging models have enabled the estimation of specific white matter fiber populations within a voxel, addressing limitations of traditional imaging markers of white matter integrity. We applied fixel based analysis (FBA) to investigate the evolution of fiber‐specific white matter changes in a prospective study of stroke patients and upper limb motor deficit over 1 year after stroke. We studied differences in fiber density and macrostructural changes in fiber cross‐section. Motor function was assessed by grip strength. We conducted a whole‐brain analysis of fixel metrics and predefined corticospinal tract (CST) region of interest in relation to changes in motor functions. In 30 stroke patients (mean age 62.3 years, SD ±16.9; median NIHSS 4, IQR 2–5), whole‐brain FBA revealed progressing loss of fiber density and cross‐section in the ipsilesional corticospinal tract and long‐range fiber tracts such as the superior longitudinal fascicle and trans‐callosal tracts extending towards contralesional white matter tracts. Lower FBA metrics measured at the brainstem section of the CST 1 month after stroke were significantly associated with lower grip strength 3 months (p = .009, adjusted R2 = 0.259) and 1 year (T4: p < .001, adj. R2 = 0.515) after stroke. Compared to FA, FBA metrics showed a comparably strong association with grip strength at later time points. Using FBA, we demonstrate progressive fiber‐specific white matter loss after stroke and association with functional motor outcome. Our results promote the application of fiber‐specific analysis to detect secondary neurodegeneration after stroke in relation to clinical recovery.
Incomplete information model of credit default of micro and small enterprises
Authors: Chen Tingqiang , Wang Suyang 
Published: August 2021

AbstractThis research constructs a credit default estimation model for micro and small enterprises (MSEs) under the condition of changing information asymmetry. The model is established through the refinement, abstraction and portrayal of the core elements contained in the default trigger mechanism; this mechanism is based on the cash flow, the default boundary and the distribution of actual cash flow in the framework of the incomplete information model. By relaxing the assumption that the bank can fully observe the customer's initial information, this work constructs a theoretical model with practical application value that can effectively describe the default risk of MSEs. Numerical simulation shows that the model can accurately estimate the default probability of MSEs by quantitatively modelling the mechanism of default risk management and control which is applicable to the risk characteristics of MSEs. The model is also suitable for the continuous dynamic estimation and forecast of individual customer credit application and post‐lending risk.
The role of mothers’ self‐compassion on mother–infant bonding during the COVID‐19 pandemic: A longitudinal study exploring the mediating role of mindful parenting and parenting stress in the postpartum period
Authors: Fernandes Daniela V. , Canavarro Maria C. , Moreira Helena 
Published: August 2021

AbstractThe current COVID‐19 pandemic is a challenging time for postpartum mothers, and associated challenges may have a negative impact on their parenting and, consequently, on mother–infant bonding. This study aimed to longitudinally explore whether mothers’ self‐compassion was associated with mother–infant bonding and whether this relationship was mediated by mindful parenting and parenting stress. A total of 125 Portuguese mothers of infants aged between 0 and 12 months completed an online survey at two assessment points during the first wave of the COVID‐19 pandemic (T1: April–May 2020; T2: June–July 2020). The survey included several questionnaires assessing sociodemographic, clinical, and COVID‐19 information; self‐compassion; mindful parenting; parenting stress; and mother–infant bonding. Mothers presented significantly higher levels of self‐compassion, less impaired mother–infant bonding, and lower levels of depressive symptoms at T2 than T1. Higher levels of self‐compassion at T1 predicted less impaired mother–infant bonding at T2, and this relationship was mediated by higher levels of mindful parenting and lower levels of parenting stress (both assessed at T1). These results highlight the relevance of mothers’ self‐compassion to establishing mother–infant bonding in the postpartum period, particularly during the COVID‐19 pandemic, and the important role of mindful parenting and parenting stress in determining this relationship.