bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Main Challenges Faced in the Implementation of Government Policy Interventions towards Access to Pre-primary and Primary Education by Street Children in North Rift, Kenya
Authors: Paul K. Lagat, , Joseph Lelan , Shadrack Saina 
Published: September 2024

Aims: Despite of the strong policy measures to have street children in school, many school-going-age are still not attending school. Therefore, the main purpose of this paper was to evaluate challenges faced in the implementation of Government policy interventions towards access to pre-primary and primary education by street children in North Rift, Kenya.
Study Design: The study adopted a mixed method research design.
Place and Duration of the Study: A survey was conducted in three towns of the North Rift Counties of Kenya (Kapsabet, Eldoret, and Kitale) which are the headquarters of the respective counties. Data collection done in the period between 1st December and 31st December 2022
Methodology: Purposive and simple random sampling was used to select 322 respondents (218 males and 23 females with a modal age of 10 -15 years; 18 female and 27 female teachers were aged between 30 – above 40 years). Data was collected using observation guides, in-depth interviews, and questionnaires. Descriptive and inferential statistics as well as theme analysis were used to analyze the data, respectively. The data was coded and analyzed using themes.
Results: Main reasons street children had not enrolled in school were a lack of money for school materials (56.2%) and an unattractive school environment (30%). Other reasons included having to work to support their families (1.3%), distance to school (0.9%), being born and raised on the streets, being over-aged, and early parenting responsibilities.
Conclusion: The study concluded that government policy interventions alone are insufficient for improving street children's access to education. Effective implementation requires collaborative efforts from all stakeholders, addressing barriers like poverty and parenting responsibilities, and restructuring education to include informal systems.
Using PKPD Modeling to Optimize Gentamicin Dosing in Saudi Neonates
Authors: Alfaifi Khalid A. 
Published: September 2024

The intricate interplay between pharmacokinetics and pharmacodynamics is pivotal in optimizing gentamicin therapy for neonates, a population characterized by unique physiological developmental considerations and pathophysiological changes in critically ill neonates. Rapid growth, Altered body composition, the immature renal function and premature immune system, significantly influence pharmacokinetic parameters Cl and Vd which aggravate complexities to achieve targets attainment and therapeutic drug monitoring compared to adults, necessitating individualized dosing strategies. The primary aim of this review, highlights the importance of PKPD modeling to optimizing gentamicin dosing in neonates Emerging trends in pediatric pharmacotherapy underscore the urgency for advancing pharmacokinetic-pharmacodynamic (PKPD) modeling to enhance therapeutic efficacy. Future research should focus on integrating real-world data from diverse neonatal populations. Genetic variations may influence the outcomes of PKPD studies, and subsequent dosing recommendations. Conducting PKPD studies in diverse populations is crucial for obtaining more robust and reliable results, which would allow for more representative models that account for physiological variations. Incorporating advanced computational techniques such as machine learning may further refine predictive accuracy, enabling personalized dosing strategies that minimize toxicity while maximizing therapeutic benefits As research evolves, the role of pediatric-specific biomarkers in PKPD modeling warrants closer investigation, potentially leading to breakthroughs that redefine dosing paradigms. By addressing these critical areas, the field can advance toward more effective and individualized pharmacotherapy, reducing adverse outcomes and improving clinical care for vulnerable neonates.
Frequency dependence in seismoacoustic imaging of shallow free gas due to gas bubble resonance
Authors: Tóth Zsuzsanna , Spiess Volkhard , Keil Hanno 
Published: December 2015

AbstractShallow free gas is investigated in seismoacoustic data in 10 frequency bands covering a frequency range between 0.2 and 43 kHz. At the edge of a gassy patch in the Bornholm Basin (Baltic Sea), compressional wave attenuation caused by free gas is estimated from reflection amplitudes beneath the gassy sediment layer. Imaging of shallow free gas is considerably influenced by gas bubble resonance, because in the resonance frequency range attenuation is significantly increased. At the resonance frequency of the largest bubbles between 3 and 5 kHz, high scattering causes complete acoustic blanking beneath the top of the gassy sediment layer. In the wider resonance frequency range between 3 and 15 kHz, the effect of smaller bubbles becomes dominant and the attenuation slightly decreases. This allows acoustic waves to be transmitted and reflections can be observed beneath the gassy sediment layer for higher frequencies. Above resonance beginning at ∼19 kHz, attenuation is low and the presence of free gas can be inferred from the decreased reflection amplitudes beneath the gassy layer. Below the resonance frequency range (<1 kHz), attenuation is generally very low and not dependent on frequency. Using the geoacoustic model of Anderson and Hampton, the observed frequency boundaries suggest gas bubble sizes between 1 and 4–6 mm, and gas volume fractions up to 0.02% in a ∼2 m thick sediment layer, whose upper boundary is the gas front. With the multifrequency acoustic approach and the Anderson and Hampton model, quantification of free gas in shallow marine environments is possible if the measurement frequency range allows the identification of the resonance frequency peak. The method presented is limited to places with only moderate attenuation, where the amplitudes of a reflection can be analyzed beneath the gassy sediment layer.
Assessing the performance of community‐available global MHD models using key system parameters and empirical relationships
Authors: Gordeev E. , Sergeev V. , Honkonen I. , Kuznetsova M. , Rastätter L. , Palmroth M. , Janhunen P. , Tóth G. , Lyon J. , Wiltberger M. 
Published: December 2015

AbstractGlobal magnetohydrodynamic (MHD) modeling is a powerful tool in space weather research and predictions. There are several advanced and still developing global MHD (GMHD) models that are publicly available via Community Coordinated Modeling Center's (CCMC) Run on Request system, which allows the users to simulate the magnetospheric response to different solar wind conditions including extraordinary events, like geomagnetic storms. Systematic validation of GMHD models against observations still continues to be a challenge, as well as comparative benchmarking of different models against each other. In this paper we describe and test a new approach in which (i) a set of critical large‐scale system parameters is explored/tested, which are produced by (ii) specially designed set of computer runs to simulate realistic statistical distributions of critical solar wind parameters and are compared to (iii) observation‐based empirical relationships for these parameters. Being tested in approximately similar conditions (similar inputs, comparable grid resolution, etc.), the four models publicly available at the CCMC predict rather well the absolute values and variations of those key parameters (magnetospheric size, magnetic field, and pressure) which are directly related to the large‐scale magnetospheric equilibrium in the outer magnetosphere, for which the MHD is supposed to be a valid approach. At the same time, the models have systematic differences in other parameters, being especially different in predicting the global convection rate, total field‐aligned current, and magnetic flux loading into the magnetotail after the north‐south interplanetary magnetic field turning. According to validation results, none of the models emerges as an absolute leader. The new approach suggested for the evaluation of the models performance against reality may be used by model users while planning their investigations, as well as by model developers and those interesting to quantitatively evaluate progress in magnetospheric modeling.
Ruthenium(II)‐Catalyzed Oxidative Annulation Reactions of Arylimidazolium Salts via N‐Heterocyclic Carbene‐Directed CH Activation
Authors: Li Renhe , Hu Yang , Liu Ran , Hu Ruofang , Li Bin , Wang Baiquan 
Published: December 2015

AbstractAn efficient ruthenium(II)‐catalyzed oxidative annulation reaction of various arylimidazolium salts with alkynes via N‐heterocyclic carbene‐directed CH activation to obtain substituted benzo[ij]imidazo[2,1,5‐de]quinolizinium salts is reported. This catalytic reaction proceeds in an excellent regioselective manner when using unsymmetrical alkynes as reactants. The intermediate mono‐annulated products can be obtained by reducing the amount of catalyst. Two catalytically competent N‐heterocyclic carbene‐based cyclometallated ruthenium(II) complexes have been isolated and characterized, which represent the key intermediates in the catalytic cycle. Moreover, most of the products show a strong fluorescent property, indicating their potential for making new light‐emitting materials.magnified image
Catalytic Enantioselective Arylative Dearomatization of 3‐Methyl‐2‐vinylindoles Enabled by Reactivity Switch
Authors: Wang Yang , Sun Meng , Yin Lei , Shi Feng 
Published: December 2015

AbstractThe first catalytic asymmetric dearomatization of 3‐methyl‐2‐vinylindoles has been established by using quinone monoimides as suitable electrophiles in the presence of chiral phosphoric acid, which afforded chiral indole derivatives bearing a quaternary stereogenic center in a chemospecific and highly enantioselective fashion (up to 81% yield, >99% ee). The success of this reaction was enabled by the reactivity switch of 3‐methyl‐2‐vinylindoles, which has not been reported before. This reaction also represents the first catalytic asymmetric arylative dearomatization of vinylindoles, which will help confront the challenges in catalytic asymmetric arylative dearomatization and dearomatization of vinylindoles.magnified image
Enantioselective Formal [4+2] Cycloadditions to 3‐Nitroindoles by Trienamine Catalysis: Synthesis of Chiral Dihydrocarbazoles
Authors: Li Yang , Tur Fernando , Nielsen Rune Pagh , Jiang Hao , Jensen Frank , Jørgensen Karl Anker 
Published: December 2015

AbstractThe first enantioselective formal [4+2] cycloadditions of 3‐nitroindoles are presented. By using 3‐nitroindoles in combination with an organocatalyst, chiral dihydrocarbazole scaffolds are formed in moderate to good yields (up to 87 %) and enantioselectivities (up to 97 % ee). The reaction was extended to include enantioselective [4+2] cycloadditions of 3‐nitrobenzothiophene. The reaction proceeds through a [4+2] cycloaddition/elimination cascade under mild reaction conditions. Furthermore, a diastereoselective reduction of an enantioenriched cycloadduct is presented. The mechanism of the reaction is discussed based on experimental and computational studies.
Total Synthesis and Biological Evaluation of Rakicidin A and Discovery of a Simplified Bioactive Analogue
Authors: Tsakos Michail , Clement Lise L. , Schaffert Eva S. , Olsen Frank N. , Rupiani Sebastiano , Djurhuus Rasmus , Yu Wanwan , Jacobsen Kristian M. , Villadsen Nikolaj L. , Poulsen Thomas B. 
Published: December 2015

AbstractWe report a concise asymmetric synthesis of rakicidin A, a macrocyclic depsipeptide that selectively inhibits the growth of hypoxic cancer cells and stem‐like leukemia cells. Key transformations include a diastereoselective organocatalytic cross‐aldol reaction to build the polyketide portion of the molecule, a highly hindered ester fragment coupling reaction, an efficient Helquist‐type Horner—Wadsworth—Emmons (HWE) macrocyclization, and a new DSC‐mediated elimination reaction to construct the sensitive APD portion of rakicidin A. We further report the preparation of a simplified structural analogue (WY1) with dramatically enhanced hypoxia‐selective activity.
Amide‐Substituted Titanocenes in Hydrogen‐Atom Transfer Catalysis
Authors: Zhang Yong‐Qiang , Jakoby Verena , Stainer Katharina , Schmer Alexander , Klare Sven , Bauer Mirko , Grimme Stefan , Cuerva Juan Manuel , Gansäuer Andreas 
Published: December 2015

AbstractTwo new catalytic systems for hydrogen‐atom transfer (HAT) catalysis involving the N−H bonds of titanocene(III) complexes with pendant amide ligands are reported. In a monometallic system, a bifunctional catalyst for radical generation and reduction through HAT catalysis depending on the coordination of the amide ligand is employed. The pendant amide ligand is used to activate Crabtree's catalyst to yield an efficient bimetallic system for radical generation and HAT catalysis.
Effects of Lowering Glycemic Index of Dietary Carbohydrate on Plasma Uric Acid Levels: The OmniCarb Randomized Clinical Trial
Authors: Juraschek Stephen P. , McAdams‐Demarco Mara , Gelber Allan C. , Sacks Frank M. , Appel Lawrence J. , White Karen J. , Miller Edgar R. 
Published: December 2015

ObjectiveThe effects of carbohydrates on plasma uric acid levels are a subject of controversy. We determined the individual and combined effects of carbohydrate quality (the glycemic index) and quantity (the proportion of total daily energy [percentage of carbohydrates]) on uric acid levels.MethodsWe conducted a randomized, crossover trial of 4 different diets in overweight or obese adults without cardiovascular disease (n = 163). Participants consumed each of 4 diets over a 5‐week period, each of which was separated by a 2‐week washout period. Body weight was kept constant. The 4 diets were high glycemic index (≥65) with high percentage of carbohydrates (58% kcal), low glycemic index (≤45) with low percentage of carbohydrates (40% kcal), low glycemic index with high percentage of carbohydrates, and high glycemic index with low percentage of carbohydrates. Plasma uric acid levels were measured at baseline and after completion of each 5‐week period for comparison between the 4 diets.ResultsOf the 163 study participants, 52% were women and 50% were non‐Hispanic African American subjects; their mean age was 52.6 years, and their mean ± SD uric acid level was 4.7 ± 1.2 mg/dl. Reducing the glycemic index lowered uric acid levels when the percentage of carbohydrates was low (−0.24 mg/dl; P < 0.001) or high (−0.17 mg/dl; P < 0.001). Reducing the percentage of carbohydrates marginally increased the uric acid level only when the glycemic index was high (P = 0.05). The combined effect of lowering the glycemic index and increasing the percentage of carbohydrates was −0.27 mg/dl (P < 0.001). This effect was observed even after adjustment for concurrent changes in kidney function, insulin sensitivity, and products of glycolysis.ConclusionReducing the glycemic index lowers uric acid levels. Future studies should examine whether reducing the glycemic index can prevent gout onset or flares.
Combined Pulmonary Fibrosis and Emphysema in Scleroderma‐Related Lung Disease Has a Major Confounding Effect on Lung Physiology and Screening for Pulmonary Hypertension
Authors: Antoniou K. M. , Margaritopoulos G. A. , Goh N. S. , Karagiannis K. , Desai S. R. , Nicholson A. G. , Siafakas N. M. , Coghlan J. G. , Denton C. P. , Hansell D. M. , Wells A. U. 
Published: December 2015

ObjectiveTo assess the prevalence of combined pulmonary fibrosis and emphysema (CPFE) in systemic sclerosis (SSc) patients with interstitial lung disease (ILD) and the effect of CPFE on the pulmonary function tests used to evaluate the severity of SSc‐related ILD and the likelihood of pulmonary hypertension (PH).MethodsHigh‐resolution computed tomography (HRCT) scans were obtained in 333 patients with SSc‐related ILD and were evaluated for the presence of emphysema and the extent of ILD. The effects of emphysema on the associations between pulmonary function variables and the extent of SSc‐related ILD as visualized on HRCT and echocardiographic evidence of PH were quantified.ResultsEmphysema was present in 41 (12.3%) of the 333 patients with SSc‐related ILD, in 26 (19.7%) of 132 smokers, and in 15 (7.5%) of 201 lifelong nonsmokers. When the extent of fibrosis was taken into account, emphysema was associated with significant additional differences from the expected values for diffusing capacity for carbon monoxide (DLco) (average reduction of 24.1%; P < 0.0005), and the forced vital capacity (FVC)/DLco ratio (average increase of 34.8%; P < 0.0005) but not FVC. These effects were identical in smokers and nonsmokers. Multivariate analysis showed that the presence of emphysema had a greater effect than echocardiographically determined PH on the FVC/DLco ratio, regardless of whether it was analyzed as a continuous variable or using a threshold value of 1.6 or 2.0.ConclusionAmong patients with SSc‐related ILD, emphysema is sporadically present in nonsmokers and is associated with a low pack‐year history in smokers. The confounding effect of CPFE on measures of gas exchange has major implications for the construction of screening algorithms for PH in patients with SSc‐related ILD.
Brennpunkt „reading animal“. Hermann Cohn und die Genese der Lesehygiene
Authors: Grütter Fabian 
Published: December 2015

AbstractFocal Point “Reading Animal”. Hermann Cohn and the Emergence of the Fin de Siècle Hygiene of Reading. From the 1860s onward, ‘eye experts’ increasingly fretted the alleged surge of myopia attributed to an increase of reading matter circulating in schools. In order to avert the inauspicious prospects, revised school desks designed to prevent children from becoming myopic were introduced. During the 1880s, said experts turned to printed matter, maintaining that books must become more reader‐ friendly. Along with the turn to books, a peculiar shift within the hygiene discourse occurred: While the ill addressed by school desk‐revisions was myopia, the goal of revising book design was to make reading less tiring. This paper explores both the shift from the hygiene of the eye to the hygiene of reading as well as the materialization of the stipulations and claims made by reading hygienists. In doing so, the paper demonstrates that optimizing the reading process was closely linked to a fear of overburdening and fatigue which expressed itself in the psychopathological discourse of the time.
Mechanism of product inhibition for cellobiohydrolase Cel7A during hydrolysis of insoluble cellulose
Authors: Olsen Johan P. , Alasepp Kadri , Kari Jeppe , Cruys‐Bagger Nicolaj , Borch Kim , Westh Peter 
Published: December 2015

ABSTRACTThe cellobiohydrolase cellulase Cel7A is extensively utilized in industrial treatment of lignocellulosic biomass under conditions of high product concentrations, and better understanding of inhibition mechanisms appears central in attempts to improve the efficiency of this process. We have implemented an electrochemical biosensor assay for product inhibition studies of cellulases acting on their natural substrate, cellulose. Using this method we measured the hydrolytic rate of Cel7A as a function of both product (inhibitor) concentration and substrate load. This data enabled analyses along the lines of conventional enzyme kinetic theory. We found that the product cellobiose lowered the maximal rate without affecting the Michaelis constant, and this kinetic pattern could be rationalized by two fundamentally distinct molecular mechanisms. One was simple reversibility, that is, an increasing rate of the reverse reaction, lowering the net hydrolytic velocity as product concentrations increase. Strictly this is not a case of inhibition, as no catalytically inactive is formed. The other mechanism that matched the kinetic data was noncompetitive inhibition with an inhibition constant of 490 ± 40 μM. Noncompetitive inhibition implies that the inhibitor binds with comparable strength to either free enzyme or an enzymesubstrate complex, that is, that association between enzyme and substrate has no effect on the binding of the inhibitor. This mechanism is rarely observed, but we argue, that the special architecture of Cel7A with numerous subsites for binding of both substrate and product could give rise to a true noncompetitive inhibition mechanism. Biotechnol. Bioeng. 2016;113: 1178–1186. © 2015 Wiley Periodicals, Inc.
Improved Efficiency for Partial Oxidation of Methane by Controlled Copper Deposition on Surface‐Modified ZSM‐5
Authors: Sheppard Thomas , Daly Helen , Goguet Alex , Thompson Jillian M. 
Published: December 2015

AbstractThe mono(μ‐oxo) dicopper cores present in the pores of Cu‐ZSM‐5 are active for the partial oxidation of methane to methanol. However, copper on the external surface reduces the ratio of active, selective sites to unselective sites. More efficient catalysts are obtained by controlling the copper deposition during synthesis. Herein, the external exchange sites of ZSM‐5 samples were passivated by bis(trimethylsilyl) trifluoroacetamide (BSTFA) followed by calcination, promoting selective deposition of intraporous copper during aqueous copper ion exchange. At an optimum level of 1–2 wt % SiO2, IR studies showed a 64 % relative reduction in external copper species and temperature‐programmed oxidation analysis showed an associated increase in the formation of methanol compared with unmodified Cu‐ZSM‐5 samples. It is, therefore, reported that the modified zeolites contained a significantly higher proportion of active, selective copper species than their unmodified counterparts with activity for partial methane oxidation to methanol.
Mechanism and Charge Effect of Cycloisomerization of ω‐Alkynylfuran Catalyzed by Subnanometer Gold Clusters: A Theoretical Study
Authors: Tang Dianyong , Yang Miao , Zhang Jin , He Rongxing , Shen Wei , Li Ming 
Published: December 2015

AbstractThe detailed reaction mechanism of the ω‐alkynylfuran cycloisomerization catalyzed by medium‐sized bare Au38 nanoclusters was investigated by means of density functional theory at the Perdew–Burke–Ernzerhof level of theory. Both the charge and size effects of the three‐dimensional gold clusters are studied at the same level. The mechanistic studies show that the 5‐exo Friedel–Crafts‐type mechanism is the most favorable mechanism, and could be selective to form phenol derivatives. Additionally, the solvation effect of acetonitrile apparently lowers the energy barrier of the first and second steps of the reaction. The positive charge on the gold clusters could enhance the catalytic activity of the clusters. Suitable positive charges on the reaction sites are essential for the formation of phenol through the cycloisomerization of ω‐alkynylfuran. The subnanometer gold clusters show high catalytic efficiency for the conversion of ω‐alkynylfurans to phenol derivatives.
NaOH‐Aided Platinum Nanoparticle Size Regulation on Polybenzimidazole‐Wrapped Carbon Nanotubes for Use as Non‐Humidified Polymer Electrolyte Fuel Cell Catalyst
Authors: Yang Zehui , Fujigaya Tsuyohiko , Nakashima Naotoshi 
Published: December 2015

AbstractWe describe a method to control the size of platinum nanoparticles (Pt‐NPs) on poly[2,2′‐(2,6‐pyridine)‐5,5′‐bibenzimidazole] (PyPBI)‐wrapped pristine multi‐walled carbon nanotubes (MWNTs) without changing the loading amount by adding various concentrations of sodium hydroxide (NaOH) to the ethylene glycol aqueous solutions. The Pt‐NP sizes decreased from 3.8±0.4 to 1.7±0.1 nm with increasing NaOH concentrations. The mass activity of the oxygen reduction reaction was 224 mA mgPt−1 for the electrocatalyst with 3 nm Pt‐NPs, in which the power density reached 350 mW cm−2, which was 1.4 times higher than that of the electrocatalyst synthesized without NaOH (250 mW cm−2) at 120 °C and without any extra humidification. The electrocatalyst synthesized from a small amount of additional NaOH (0.5 mm) in the starting solution shows an enhanced performance and similar Pt stability. More importantly, the Pt‐NP size showed no effect on the Pt stability owing to the use of the PyPBI.