bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical linear algebra in data assimilation
Authors: Freitag Melina A. 
Published: September 2023

AbstractData assimilation is a method that combines observations (ie, real world data) of a state of a system with model output for that system in order to improve the estimate of the state of the system and thereby the model output. The model is usually represented by a discretized partial differential equation. The data assimilation problem can be formulated as a large scale Bayesian inverse problem. Based on this interpretation we will derive the most important variational and sequential data assimilation approaches, in particular three‐dimensional and four‐dimensional variational data assimilation (3D‐Var and 4D‐Var) and the Kalman filter. We will then consider more advanced methods which are extensions of the Kalman filter and variational data assimilation and pay particular attention to their advantages and disadvantages. The data assimilation problem usually results in a very large optimization problem and/or a very large linear system to solve (due to inclusion of time and space dimensions). Therefore, the second part of this article aims to review advances and challenges, in particular from the numerical linear algebra perspective, within the various data assimilation approaches.
Development of Nitroreductase‐Activatable Fluoroquinolone Prodrugs Exhibiting Attenuated Magnesium Ion Binding
Authors: Zhao Zhenxiang , Yadav Anuj K. , Weng Yourong , Chan Jefferson 
Published: September 2023

AbstractFluoroquinolones such as levofloxacin and ciprofloxacin are potent antibiotics prescribed to treat various bacterial infections. Recent studies have also identified prominent examples as promising anti‐cancer agents. However, significant off‐target effects observed in human patients have precluded their wide‐spread clinical use. For instance, upon systemic administration, overt toxicity toward eukaryotic organelles (i. e., mitochondria) can result to the destruction of healthy tissue. Moreover, fluoroquinolones feature a β‐ketoacid motif which binds to and strips magnesium ions from cartilage, leading to rupture of the Achilles tendon. In this study, we have masked the β‐ketoacid of levofloxacin and ciprofloxacin (as well as two quinolones) with a nitroreductase (NTR)‐responsive warhead appended through a new self‐immolative prodrug linker. The resulting β‐ketoester functional group was found to be remarkably resistant toward spontaneous hydrolysis, esterase activity, as well as other ester‐cleaving enzymatic systems. Further testing also reveal no cross‐reactivity against commonly encountered biologically relevant analytes (e. g., ROS and thiols). Importantly, we demonstrate that upon esterification, the binding toward magnesium ions was attenuated based on an in vitro fluorescent competition assay with the unmodified parent drug.
Scalable, Chromatography‐Free Synthesis of 2‐(3‐Bromophenyl)‐2H‐1,2,3‐triazole through N−N Bond Forming Cyclization
Authors: Kohler Philipp , Schindelholz Ivan , Schäfer Gabriel 
Published: September 2023

Abstract2‐(3‐Bromophenyl)‐2H‐1,2,3‐triazole is a low molecular‐weight building block that is not readily accessible in pure form by standard synthetic approaches due to competing formation of the triazol‐1‐yl regioisomer. After investigation of a wide range of synthetic routes, a process based on construction of the triazole heterocycle by cyclization of an activated dihydrazone was developed. A suitable isolation method had to be identified before embarking on a demonstration run on >100 g scale without the need for chromatography. The new process delivered the desired building block in 48 % overall yield over four telescoped steps with excellent purity (99 % a/a).
A modified SWAT model for mechanistic simulation of soil water‐salt transport and the interactions with shallow groundwater
Authors: Mu Danning , Xun Yihao , Gao Ya , Ren Dongyang , Sun Chen , Ma Xin , Huang Guanhua , Xu Xu 
Published: September 2023

AbstractCurrent hydrological models still face difficulties in accurately simulating vadose zone (VZ) hydrological processes in arid watersheds with shallow groundwater environments. Therefore, this article introduces a new mechanistic VZ module coupled with an improved groundwater‐balance (GWB) module to enhance the capabilities of the well‐known Soil Water Assessment Tools (SWAT) model. The main improvements and features of the modified SWAT model (M‐SWAT) include: a numerical VZ module to accurately simulate soil water‐salt transport under variably saturated conditions by solving the head‐formed Richards' equation and advection‐dispersion equation; a GWB module (on a sub‐basin scale for shallow aquifer) coupled with VZ module by proposing an effective way of boundary information exchanges; and a more reasonable water‐salt stress functions (i.e., based on matric head and osmotic head) to calculate root water uptake and plant growth. The M‐SWAT was then tested and evaluated with two‐year observation data from the Yangchang canal command area (YCA, an experimental site) and the Jiyuan Irrigation System (Jiyuan, region‐scale), located in the arid upper Yellow River basin of northwest China. The model produced a good agreement between the simulated and observed data in both calibration and validation with sufficiently small root mean square error (RMSE). The determination coefficient (R2) was greater than 0.51, 0.36, and 0.87 in simulating the soil water‐salt dynamics, groundwater depth fluctuations, and leaf area index development, respectively. Case testing also proved that the M‐SWAT had sufficient computational efficiency and stability for regional application. Further comparisons with previous studies indicated that the M‐SWAT could more accurately and rationally simulate the soil water‐salt dynamics and their interactions in arid watersheds with shallow groundwater tables.
Implications of bank competition, financial stability, and gender gap on access to finance: Evidence from Sub‐Saharan Africa
Authors: Rakshit Bijoy , Bardhan Samaresh 
Published: September 2023

AbstractWhether bank competition promotes access to finance is highly debated in economic literature and policy circles. Amidst this debate, this paper investigates the implications of bank competition, financial stability, and gender gap on access to finance for 40 Sub‐Saharan African countries using 12,504 firm‐level observations from the World Bank Enterprise Survey. In addition to structural measures, competition has been measured by three non‐structural measures (Lerner index, Boone indicator, and Panzar‐Rosse H‐statistic). Results obtained through the probit model and probit model with sample selection (PSS) suggest that a higher degree of bank competition positively affects firm's credit availability in the Sub‐Saharan African region. Results also indicate that firms owned by female entrepreneurs are more likely to report greater difficulties in obtaining formal finance. The findings suggest that policymakers and other stakeholders should direct policy actions that promote competition in the credit market by reducing the cost of credit.
Joint elicitation of elasticity of intertemporal substitution, risk and time preferences
Authors: de Castro Luciano , Galvao Antonio F. , Montes‐Rojas Gabriel , Olmo Jose 
Published: September 2023

AbstractThe elicitation of the elasticity of intertemporal substitution (EIS), discount factor and risk attitude parameters in dynamic models is of central importance to economics, finance and public policy. This paper suggests an alternative method to jointly elicit and estimate these three parameters using experimental data. We employ a new model based on dynamic quantile preferences, where individuals maximize the stream of future ‐quantile utilities, for . These preferences are simple, dynamically consistent and monotonic. In the quantile model, the risk attitude is captured by the quantile of the payoff distribution, while the EIS and the discount factor are related to the utility function describing individual's intertemporal behaviour, hence allowing for complete separability between risk, EIS and discount factor. The estimation of the parameters of interest uses a structural maximum likelihood method. Individual's risk aversion is estimated below the median. The discount factor is marginally smaller than estimates reported in the literature, and the EIS is slightly larger than one, which suggests that utility over time is concave. The estimates for the elasticity contrast with those reported by the existing studies using observational disaggregated data, which in general find an elasticity smaller than one.
An obstetric‐specific surgical Apgar score predicts maternal morbidity from cesarean hysterectomy for placenta accreta spectrum
Authors: Munoz Jessian L. , Curbelo Jacqueline , Ramsey Patrick S. 
Published: September 2023

AbstractObjectivePlacenta accreta spectrum (PAS) is a continuum of placental conditions characterized by significant maternal and neonatal morbidity. Tools to accurately predict postoperative morbidity have been lacking due to the hemodynamic changes of pregnancy. The surgical Apgar score (SAS) is a 10‐point scale that assesses heart rate, mean arterial pressure, and estimated blood loss. The SAS has been validated to predict morbidity such as blood transfusion and reoperation.MethodsWe created an obstetric‐specific SAS (ObSAS) scale for physiologic changes of pregnancy (two‐fold increase in blood loss, 10% increased heart rate, and 5% decreased mean arterial pressure) and analyzed 110 cases of PAS who underwent cesarean hysterectomy.ResultsAn ObSAS of 0–4 (poorest score) was significantly associated with increased risk of intensive care unit (ICU) admission (odds ratio [OR] 40.6, 95% confidence interval [CI] 7.9–742.9), transfusion >4 units (26/26 patients), and greater surgical morbidity (OR 22.7, 95% CI 4.4–415.0). ObSAS of 9–10 resulted in no ICU admissions (0/12), fewer blood transfusions (OR 0.1, 95% CI 0.1–0.4). and less surgical morbidity (OR 0.09, 95% CI 0.01–0.37).ConclusionGiven the overall surgical morbidity associated with PAS cesarean hysterectomy, the ObSAS score is a powerful tool with excellent predictive capabilities for ICU admission, blood transfusion, and surgical morbidity, allowing for resource allocation, prophylactic interventions, and optimal patient outcomes.
Layer‐controlled nonlinear terahertz valleytronics in two‐dimensional semimetal and semiconductor PtSe2
Authors: Hemmat Minoosh , Ayari Sabrine , Mičica Martin , Vergnet Hadrien , Guo Shasha , Arfaoui Mehdi , Yu Xuechao , Vala Daniel , Wright Adrien , Postava Kamil , Mangeney Juliette , Carosella Francesca , Jaziri Sihem , Wang Qi Jie , Liu Zheng , Tignon Jérôme , Ferreira Robson , Baudin Emmanuel , Dhillon Sukhdeep 
Published: September 2023

AbstractPlatinum diselenide () is a promising two‐dimensional (2D) material for the terahertz (THz) range as, unlike other transition metal dichalcogenides (TMDs), its bandgap can be uniquely tuned from a semiconductor in the near‐infrared to a semimetal with the number of atomic layers. This gives the material unique THz photonic properties that can be layer‐engineered. Here, we demonstrate that a controlled THz nonlinearity—tuned from monolayer to bulk —can be realized in wafer size polycrystalline through the generation of ultrafast photocurrents and the engineering of the bandstructure valleys. This is combined with the layer interaction with the substrate for a broken material centrosymmetry, permitting a second order nonlinearity. Further, we show layer dependent circular dichroism, where the sign of the ultrafast currents and hence the phase of the emitted THz pulse can be controlled through the excitation of different bandstructure valleys. In particular, we show that a semimetal has a strong dichroism that is absent in the monolayer and few layer semiconducting limit. The microscopic origins of this TMD bandstructure engineering are highlighted through detailed DFT simulations, and shows the circular dichroism can be controlled when becomes a semimetal and when the K‐valleys can be excited. As well as showing that is a promising material for THz generation through layer controlled optical nonlinearities, this work opens up a new class of circular dichroism materials beyond the monolayer limit that has been the case of traditional TMDs, and impacting a range of domains from THz valleytronics, THz spintronics to harmonic generation.image
Progress and prospect of nanotechnology for cardiac fibrosis treatment
Authors: Gaytan Samantha L. , Beaven Elfa , Gadad Shrikanth S. , Nurunnabi Md 
Published: September 2023

AbstractCardiac fibrosis is the excessive accumulation of extracellular matrix components in the heart, leading to reduced cardiac functionality and heart failure. This review provides an overview of the therapeutic applications of nanotechnology for the treatment of cardiac fibrosis. We first delve into the fundamental pathophysiology of cardiac fibrosis, highlighting the key molecular players, including Matrix Metalloproteinases, Transforming Growth Factor‐beta, and several growth factors, cytokines, and signaling molecules. Each target presents a unique opportunity to develop targeted nano‐therapies. We then focus on recent advancements in nanotechnology and how nanoparticles can be engineered to deliver drugs or therapeutic genes. These advanced delivery approaches have shown significant potential to inhibit fibrosis‐promoting factors, thereby mitigating the fibrotic response and potentially reversing disease progression. In addition, we discuss the challenges associated with developing and translating nanotechnology‐based drug delivery systems, including ensuring biocompatibility, safety, and regulatory compliance. This review highlights how nanotechnology can bridge the gap between lab research and clinical practice for treating cardiac fibrosis.
The clinical value of echocardiography combined with transabdominal vascular ultrasound in the diagnosis of different types of aortic dissection
Authors: Zhong Weihua , Li Kejun , Wang Fen , Zhang Tao , Xu Shouhong , Yao Shuzhi 
Published: September 2023

AbstractPurposeTo analyze the clinical values of echocardiography combined with vascular ultrasound in the diagnosis of aortic dissection according to the DeBakey classification.MethodsThe clinical data of 77 patients with aortic dissection admitted to our hospital from August 2016 to January 2022 were retrospectively analyzed. All patients were examined with ultrasound and CT angiography (CTA), the consistency between ultrasound and CTA ± intraoperative diagnosis for the classification of AD was checked, as well as the differences in ultrasound signs and Ultrasound parameters between different types of AD were analyzed.ResultsThe results of Kappa value: There was a high level of agreement between echocardiography combined with transabdominal vascular ultrasound and CTA ± intraoperative diagnosis for the classification of AD (Kappa = 0.897, p = 0.000). In the ultrasound signs, the proportion of pericardial effusion, aortic regurgitation, aortic widening, and coronary artery involvement in type DeBakey I and II aortic dissection was significantly higher than that in Type III. There was no significant difference in the proportion of intimal floating, true and false lumen, and intimal rupture in Types I, II, and III aortic dissections. In the comparison of ultrasound parameters, there is a statistically significant difference in the values of LAD (left atrial diameter), LAV (left atrial volume), and LVEDD (left ventricular end‐diastolic diameter) among different types of aortic dissection. There is no significant difference in IVS (interventricular septum thickness), LVPW (left ventricular posterior wall thickness), LVEF (left ventricular ejection fraction), and E/e′ ratio among different types of aortic dissection.ConclusionEchocardiography combined with transabdominal vascular ultrasound can accurately evaluate aortic dissection with real‐time dynamic images and provide important clinical significance for early individualized treatment of patients through accurate classification of different aortic dissection.
Assessment of the Prognostic Value of MRI Left Ventricular Global Function Index (LVGFI) in Patients With End‐Stage Renal Disease Under Maintenance Dialysis
Authors: Zhang Tian‐yi , An Dong‐aolei , Fang Yan , Zhou Hang , Yan Hao , Chen Binghua , Lu Renhua , Fang Wei , Wang Qin , Che Xiajing , Xu Yao , Huang Jiaying , Jin Haijiao , Shen Jianxiao , Mou Shan , Wu Lian‐Ming 
Published: September 2023

BackgroundLeft ventricular global function index (LVGFI) integrates LV volumetric and functional parameters. In patients with end‐stage renal disease (ESRD), cardiac injury manifests as LV hypertrophy and dysfunction. However, the prognostic value of LVGFI in this population remains unclear.PurposeTo investigate the association of LVGFI with major adverse cardiac events (MACE) in patients with ESRD.Study TypeProspective.PopulationOne hundred fifty‐eight ESRD patients (mean age: 54.1 ± 14.4 years; 105 male) on maintenance dialysis.Filed Strength/Sequence3.0 T, balanced steady‐state free precession (bSSFP) cine and modified Look‐Locker inversion recovery (MOLLI) sequences.AssessmentLV volumetric and functional parameters were determined from bSSFP images. LVGFI was calculated as the ratio of stroke volume to global volume and native T1 was determined from MOLLI T1 maps. MACE was recorded on follow up. Models were developed to predict MACE from conventional risk factors combined with LVGFI, GLS, native T1, and LV mass index (LVMI), respectively. Subgroup analyses were further performed in participants with LVEF above median.Statistical TestsCox proportional hazard regression and log‐rank test were used to investigate the association between LVGFI and MACE. The predictive models were evaluated and compared using Harrell's C‐statistics and DeLong tests. A P value <0.05 was considered statistically significant.ResultsThirty‐four MACE occurred during the median follow‐up period of 26 months. The hazard of MACE increased by 114% for each 10% decrease in LVGFI in univariable analysis. The predictive model consisting of LVGFI (C‐statistic: 0.724) had significantly better predictive performance than the others (all P < 0.001). These results were consistent in patients (N = 79) with LVEF > median (63.54%).Data ConclusionLVGFI is a novel marker for MACE risk stratification in patients with ESRD and was better able to predict MACE than native T1 mapping and GLS.Evidence Level2Technical EfficacyStage 3
Time‐Resolved Quantification of Patellofemoral Cartilage Deformation in Response to Loading and Unloading via Dynamic MRI With Prospective Motion Correction
Authors: Rovedo Philipp , Meine Hans , Hucker Patrick , Taghizadeh Elham , Izadpanah Kaywan , Zaitsev Maxim , Lange Thomas 
Published: September 2023

BackgroundIn vivo cartilage deformation has been studied by static magnetic resonance imaging (MRI) with in situ loading, but knowledge about strain dynamics after load onset and release is scarce.PurposeTo measure the dynamics of patellofemoral cartilage deformation and recovery in response to in situ loading and unloading by using MRI with prospective motion correction.Study TypeProspective.SubjectsTen healthy male volunteers (age: [31.4 ± 3.2] years).Field Strength/SequenceT1‐weighted RF‐spoiled 2D gradient‐echo sequence with a golden angle radial acquisition scheme, augmented with prospective motion correction, at 3 T.AssessmentIn situ knee loading was realized with a flexion angle of approximately 40° using an MR‐compatible pneumatic loading device. The loading paradigm consisted of 2 minutes of unloaded baseline followed by a 5‐minute loading bout with 50% body weight and an unloading period of 38 minutes. The cartilage strain was assessed as the mean distance between patellar and femoral bone–cartilage interfaces as a percentage of the initial (pre‐load) distance.Statistical TestsWilcoxon signed‐rank tests (significance level: P < 0.05), Pearson correlation coefficient (r).ResultsThe cartilage compression and recovery behavior was characterized by a viscoelastic response. The elastic compression ([−12.5 ± 3.1]%) was significantly larger than the viscous compression ([−7.6 ± 1.5]%) and the elastic recovery ([10.5 ± 2.1]%) was significantly larger than the viscous recovery ([6.1 ± 1.8]%). There was a significant residual offset strain ([−3.6 ± 2.3]%) across the cohort. A significant negative correlation between elastic compression and elastic recovery was observed (r = −0.75).Data ConclusionThe in vivo cartilage compression and recovery time course in response to loading was successfully measured via dynamic MRI with prospective motion correction. The clinical relevance of the strain characteristics needs to be assessed in larger subject and patient cohorts.Level of Evidence2Technical EfficacyStage 1
Role of cAMP receptor protein in phenotype and stress tolerance in Salmonella enterica serovar Typhimurium
Authors: Sawant Kirti , Shashidhar Ravindranath 
Published: September 2023

AbstractSalmonella enterica serovar Typhimurium (S. Typhimurium) is exposed to biotic and abiotic stresses. The survival of Salmonella in nature depends on the global regulators like cAMP receptor protein (CRP). The role of CRP in the phenotypic characteristics and stress tolerance was elucidated in S. Typhimurium using a crp gene null mutant (Δcrp). A 1.6‐fold decrease in the cell size, a two‐fold reduction in the colony size, and a 3.5‐fold decrease in motility were observed in the Δcrp compared with the S. Typhimurium wild‐type (WT). H2S production on selective media was affected in the Δcrp. The utilisation of d‐mannose, d‐glycerol and d‐mannitol was completely affected, whereas that of d‐galactose and d‐fructose was partially affected. The utilisation of d‐arabinose was induced in the Δcrp. The growth rate of the Δcrp in Luria Bertani medium was unaffected. However, in the glucose‐containing minimal medium, the growth rate of the Δcrp was reduced by 1.5‐fold compared with the WT. The Δcrp was able to utilise ethanolamine as the sole carbon source similar to the WT. The Δcrp was more tolerant to heat and oxidative stress. Overexpression of heat and oxidative stress‐related genes was observed in the Δcrp in the stationary phase. The Δcrp was less tolerant to radiation stress compared with the WT. The current findings decisively establish the CRP protein as a global regulator. The CRP affects multiple phenotypes, carbon metabolism and stress physiology of S. Typhimurium.
Apigenin promotes antibacterial activity via regulation of nitric oxide and superoxide anion production
Authors: Kim Suhyun , Woo Eun‐Rhan , Lee Dong Gun 
Published: September 2023

AbstractApigenin is a naturally occurring flavone isolated from the medicinal herb, Aster yomena. The present study was designed to elucidate the apoptosis‐like antibacterial mechanism of apigenin in Escherichia coli. Administration of apigenin resulted in a rapid increase in intracellular calcium accompanied by an increase in reactive nitrogen species (RNS) and nitric oxide (NO) levels. Furthermore, apigenin increases reactive oxygen species (ROS), superoxide anion (O2–) which left E. coli with no ability to activate superoxide dismutase. Finally, we found that perturbance of the membrane lipid bilayer leading to glutathione oxidation and formation 8‐hydroxy‐2′‐deoxyguanosine occurred during the process and apoptosis‐like death hallmarks were further observed. Furthermore, we applied the NO synthase inhibitor (
l‐NAME) and the O2– scavenger (Tiron) and observed attenuation in apoptotic markers under their presence. Taken together, these results suggest that apigenin induces bacterial apoptosis via activation of cellular oxidative pathways dependent on the production and accumulation of RNS/ROS.