bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization and Use of the Silicon Intensified Target Vidicon Detector in Basic and Applied Research in Atomic Spectroscopy
Authors: Olesik John W. , Walters John P.
Published: July 2005

In this paper we briefly discuss the operation of the silicon intensified target (SIT) vidicon, describing what we conclude to be the most important properties of the detector. We provide experimental evaluation of the SIT vidicon characteristics, including two-dimensional image fidelity, channel-to-channel and pixel-to-pixel response as a function of position on the detector, and temporal resolution and gating. We illustrate how these unique properties enhance our ability to make spectroscopic measurements, as well as how, at the same time, they impose limitations on the use of the SIT vidicon. We describe a variety of experiments which employed an SIT vidicon detection system for atomic spectroscopy with various degrees of spatial and temporal resolution.
Spectrometric Characterization of Metribuzin and its Metabolites
Authors: Albro P. W. , Parker C. E. , Marbury G. D. , Hernandez O. , Corbin F. T.
Published: July 2005

Metribuzin and its three major plant metabolites have been characterized by ultraviolet, infrared, and proton NMR spectroscopy and mass spectrometry. The reported structures for these compounds have been confirmed, except that deaminated Metribuzin (DA) exists mainly in the enol form rather than the keto form usually reported. Evidence is presented concerning the most probable sites of protonation during titration of these compounds. Whereas diketo Metribuzin (DK) does undergo protonation of the amino group, Metribuzin itself apparently does not. Keto/enol tautomerism as a function of pH greatly complicates interpretation of the spectra. Metribuzin appears to form a poorly soluble, hydrogen-bonded dimer (or polymer) when titrated from basic to acidic pH.
Evaluation of Atomic Fluorescence Detection Limits with an Inductively Coupled Plasma as an Excitation Source and Atomization Cell
Authors: Long Gary L. , Winefordner J. D.
Published: July 2005

The use of an inductively coupled plasma, ICP, as an excitation source for atomic fluorescence spectrometry, AFS, in a second ICP is re-examined. Improvements in the ICP-ICP-AFS setup have allowed the lowering of the limits of detection by one to two orders of magnitude below that of previous work. Also discussed is a new mode of operation for the atomization cell ICP. Through simple torch-position and flow-rate adjustments, a thin plasma, which extends 20 to 30 cm above the torch, can be produced. This plasma is referred to as the pencil plasma. With the use of these operating conditions, propane can be added to the Ar nebulizing gas to aid in refractory-element determination. The pencil plasma and the conventional plasma will be compared for use as an atom reservoir for AFS measurements.
Preparation of Calibration Standards for Quantitative Diffuse Reflectance Infrared Spectrometry
Authors: Hamadeh Issam M. , Yeboah S. Agyare , Trumbull Kathy A. , Griffiths Peter R.
Published: July 2005

Several methods of preparing mixtures of powdered samples for diffuse reflectance infrared spectrometry are described. Simply grinding two materials together does not usually lead to a homogeneous mixture because the softer material will adhere to the walls of the vessel holding the mixture. The components should be ground separately and then mixed and shaken together vigorously, preferably using a mechanical device such as a Wig-L-Bug.
Examination of a C-Black by Various FT-IR Spectroscopic Methods
Authors: Rockley M. G. , Ratcliffe A. E. , Davis D. M. , Woodard M. K.
Published: July 2005

Carbon-black prepared by combustion of hexane has been studied by Fourier-transformed infrared spectroscopy, with the use of transmission, attenuated total reflectance, diffuse reflectance, and photoacoustic detection methods. When compared, the results indicate the presence of oxidative functional groups on the carbon-black lattice. The results obtained by photoacoustic detection differ substantially from those obtained by the other methods. The explanation offered is that the photoacoustic method produces a spectrum which is defined only by the optical characteristics of the interferometer head. A ratio of the photoacoustic spectrum to the standard TGS detector single beam spectrum results in the observation of the spectroscopic sensitivity profile of the TGS detector. For these low acoustic modulation frequencies, carbon-black is observed to display no surface functionality by FT-IR-PAS detection. This distinguishes FT-IR-PAS as an analytical tool for this particular chemical system.
Temperature Effects on Electronic Spectral Absorptions of Aqueous Electrolyte Solutes I: An Optical Microautoclave
Authors: Toy Madeline S. , Stringham Roger S. , Floyd Mark S. , Passell Thomas O.
Published: July 2005

A high-temperature optical microautoclave for maintaining aqueous solution at elevated temperatures and pressures is described. The apparatus is being used to monitor the chemical processes taking place during temperature cyclings. Some spectra of copper(II) and iron(II) solutions are presented as examples up to 200°C and 15.3 atm estimated pressure.
Determination of Germanium in Coal Ashes by Inductively Coupled Plasma Atomic Emission Spectrometry
Authors: Botto R. I.
Published: July 2005

R. A. Nadkarni
Nonlinear Detector Response in FT-IR
Authors: Chase D. B.
Published: July 2005

The problem of nonlinear detector response in FT-IR spectroscopy is discussed. The effects of nonlinearity are demonstrated with the use of synthetic data, and a convenient method for detection of the nonlinear response is given. The interaction between phase correction and nonlinear response is also shown with the use of synthetic data.
Determination of Phenols in Water Using Raman Spectroscopy
Authors: Marley Nancy A. , Mann Charles K. , Vickers Thomas J.
Published: July 2005

The potential of Raman spectroscopy for quantitative analysis of phenols in water solution has been investigated. A group of six compounds—phenol, o-chlorophenol, 2, 4-dichlorophenol, 2, 4, 6-trichlorophenol, 2-chloro-S-methylphenol and 2-chloro-4-nitrophenol—was studied with the use of the 514.5, 488.0, and 457.9 nanometer lines of an argon ion laser. Attention was given to the effects of source intensity, optical alignment, and background fluctuations on quantitative results. It was found that the use of an internal standard with each measurement made a significant improvement in the accuracy and precision of results. Two methods of quantitation, peak area measurement and cross-correlation, were used. Results were somewhat better for cross-correlation, presumably because of more effective exclusion of background interference. Limits of detection were calculated based upon the slope and the standard deviation of the intercept of the standard curve. These varied from the range of 100 ppm to 0.3 ppm, depending on the compound. The most important factor controlling sensitivity is occurrence of resonance enhancement.
Nebulization with Nitrogen versus Argon in the DCP
Authors: Mangold R. A. , Bastiaans G. J.
Published: July 2005

The consequences of using N2 as a nebulizer gas during operation of a direct current plasma were evaluated with respect to its utility as a practical analytical procedure. Performance of the N2 system vs. that of an all-Ar plasma was compared on the basis of background plasma emission, atomization efficiency, detection limits, sensitivity, plasma electron density, and immunity from the easily ionized matrix element interference effect. Observations with regard to the mechanism of the EIE effect were also made. It was concluded in many cases that the use of N2 as a nebulizer gas does not significantly degrade analytical performance. An exception to this conclusion was the finding that refractory samples did not atomize as efficiently in the N2 plasma system.
Jet-Impact Nebulization for Sample Introduction in Inductively Coupled Plasma Spectrometry
Authors: Doherty M. P. , Hieftje G. M.
Published: July 2005

A novel, simple device for the production of liquid aerosol has been constructed and evaluated. In operation of this device, a sample solution is forced under pneumatic or mechanical pressure through an orifice of 25–60 micrometers in diameter. The resulting high-velocity stream of solution is directed onto a solid surface, thereby generating a fine aerosol. Details of nebulizer construction and operation are discussed and factors affecting nebulizer performance are examined. The utility of this nebulizer as a sample-introduction device for inductively coupled plasma spectrometry is explored. When coupled with an ICP, the jet-impact nebulizer compares favorably with a conventional pneumatic nebulizer in terms of precision, linearity, detection limits, and efficiency. Moreover, aerosol production is independent of any gas flow, making the device potentially useful in low-gas-flow plasmas. However, clogging of the nebulizer orifice with particulate matter can be a problem unless solutions are pre-filtered.
Microscopic Investigations of the Material Eroded by a High Voltage Spark Discharge
Authors: Helmer Deborah J. C. , Walters J. P.
Published: July 2005

The material eroded by a high voltage spark discharge in a point-to-plane configuration was investigated. Glass microscope slides were used to collect material close to the spark discharge and material which had traveled away from the spark. The effluent was also directed into a microwave discharge, and material from the spark which had traveled through this discharge was collected and inspected. The collected material was visually inspected with a light microscope and with a Scanning Electron Microscope (SEM).

Using these microscopes, it was found that the material collected near the spark discharge consisted mainly of very small particles, although some larger droplets were also observed. As the material was collected farther from the spark, larger particles were observed. These were apparently aggregations of the smaller particles observed close to the spark. When these large particles passed through the microwave plasma, some were melted.
The Effect of Particle Size on FT-IR-PAS Spectra
Authors: Rockley N. L. , Woodard M. K. , Rockley M. G.
Published: July 2005

FT-IR-PAS has been used to study minerals, monodisperse polymer beads, and organic crystals of size ranges varying from 5 μm up to several hundred μm diameter. In results that are to be expected, it has been found that the FT-IR-PAS spectra show a fairly complicated dependence on size at a resolution of 8 cm−1 for polymer beads up to a diameter of 35 μm. AC Fine Test Dust samples in cuts 5 μm up to 35 μm were found to have FT-IR-PAS spectra that varied with diameter of the sample by as much as 5% of the intensity of the bands. This was thought to be due to chemical inhomogeneity exaggerated by the process of aerodynamic sizing of the samples. The FT-IR-PAS spectra of paranitrophenol samples showed a decrease in band intensity and an increase in band width which was most dramatic when the average crystal diameter exceeded about 75 μm. It has been concluded that FT-IR-PAS spectroscopy suffers from the same limitations of spectral distortion with particle size as has been observed for visible photoacoustic spectra and for diffuse reflectance (DRIFT) spectra.
Fourier Transform Filtering of Two-Dimensional Fluorescence Data
Authors: Rossi T. M. , Warner I. M.
Published: July 2005

Fourier transform data filtering is applied to video fluorometric data. Minimum mean square error analysis is used to evaluate the effectiveness of various smoothing filters applied to noisy spectra of perylene. The equivalent width criteria for predicting the optimum filter radii in two dimensions are tested. Image sharpening of poorly resolved data is also demonstrated. The use of data filtering to aid in the visual interpretation of HPLC/VF data is demonstrated.
Deformation Studies of Polymers by Time-Resolved Fourier Transform Infrared Spectroscopy III: A New Approach
Authors: Lasch J. E. , Burchell D. J. , Masoaka T. , Hsu S. L.
Published: July 2005

A new time-resolved Fourier transform infrared spectroscopy technique has been developed for commercial fast scanning interferometers. In contrast to the methods developed previously, this one has greater flexibility in the time resolution achievable (100 microseconds to seconds) and can be easily adapted to measure a variety of external experiments. Experiments are given demonstrating the correct operation of this technique and its applicability in following the deformation behavior in polymers.
Fourier Analysis Enhances NIR Diffuse Reflectance Spectroscopy
Authors: McClure W. F. , Hamid Abdul , Giesbrecht F. G. , Weeks W. W.
Published: July 2005

Fourier coefficients computed from the NIR spectra of pulverized tobacco samples can be used to estimate certain chemical constituents in the samples. As few as 11 coefficients from the Fourier domain used in a stepwise multiple linear regression (SMLR) model provide results equivalent to a 7-term SMLR model using log 1/ R from the wavelength domain. The Fourier model reduces the computation time for calibration by 96% compared to the wavelength model, and reduces the magnetic storage space requirements by 98%. Removing the mean term from the Fourier model partially corrects the particle size anomaly encountered in pulverized samples.
GC/FT-IR Experimental Considerations in the Separation of Complex Hydrocarbon Mixtures Using Fused Silica Columns
Authors: Cooper J. R. , Taylor L. T.
Published: July 2005

The successful interfacing and utilization of fused silica capillary GC columns with Fourier transform infrared spectrometry (FT-IR) can introduce difficulties not usually encountered with lower efficiency (higher capacity) GC columns. Recognition of these difficulties, however, can lead to refinement of a GC/FT-IR detection system which can analyze complex samples with low nanogram detection limits. Chromatographic and spectrometric considerations include lightpipe temperature, choice of sample introduction, column concentration dynamic range capability, infrared data acquisition rate, and spectral S/N ratio. These parameters as they relate to capillary GC/FT-IR method development are discussed. The GC/FT-IR analysis of a complex sample is presented in an effort to explain these problems. In order to reflect the FT-IR sensitivity under complex sample chromatographic conditions, quantification data using known compounds are also included.
Deformation Studies of Polymers by Fourier Transform Infrared Spectroscopy II: Mechanical Stretcher and its Interface to the Spectrometer
Authors: Burchell D. J. , Lasch J. E. , Dobrovolny E. , Page N. , Domian J. , Farris R. J. , Hsu S. L.
Published: July 2005

We have built a hydraulic mechanical stretcher to be used with a Fourier transform infrared spectrometer to monitor molecular response when polymer samples are deformed macroscopically. Experiments on ethylene-methacrylic acid copolymers and their neutralized forms have been carried out to demonstrate the potential usefulness of this type of experiments.
Smoothing and Differentiation of Spectroscopic Curves Using Spline Functions
Authors: Gans Peter , Gill J. Bernard
Published: July 2005

The use of B-splines for smoothing and differentiation of spectroscopic curves has been investigated. The theory of B-splines and their use are outlined. For single Lorentzian and Gaussian curves, optimal spline functions of degrees 3–7 inclusive, based on symmetric arrangements of 5, 6, and 7 knots, have been computed. Various schemes for the automatic selection of knots used in fitting experimental curves have been investigated and some schemes have been applied to data obtained by Raman spectroscopy.
Identification of Inclusions in Lung Tissue with a Raman Microprobe
Authors: Buiteveld H. , De Mul F. F. M. , Mud J. , Greve J.
Published: July 2005

Inhaled particles smaller than 4 μm can cause damage to lung tissue, a disease called silicosis. We present an investigation on the use of a Raman microspectrometer for the identification of inclusions in lung tissue. We measured Raman spectra of such inclusions in lung tissue of a patient whose probable cause of death was silicosis. Most of the inclusions we could identify were calcite particles.
Characterization of Optical Diffraction and Crystal Structure in Monodisperse Polystyrene Colloids
Authors: Carlson Roger J. , Asher Sanford A.
Published: July 2005

Bragg diffraction of laser light from crystalline aqueous colloids of polystyrene spheres is examined to determine crystal structure, orientation, and elasticity. A new technique using Kossel rings is described which simultaneously measures structure, lattice spacings, and crystallite orientation. The monodisperse polystyrene sphere latex dispersions crystallize into large single crystals, which, depending on sphere concentration, are either face-centered or body-centered cubic. The interparticle spacings in the crystals are many times larger than the sphere diameter (0.109 μm). The use of tunable lasers to easily determine crystal structure is described, and the technique is further illustrated by the experimental determination of the bulk modulus. The bulk modulus is a macroscopic physical constant which can be used to monitor intersphere potentials and the screening of the particle charges by electrolytes in the solution. Data are presented which suggest that crystallite orientation occurs with the closest packed sphere layers parallel to the sample cell quartz walls.
Ultra-High Mass Spectrometry
Authors: Campana Joseph E. , Colton Richard J. , Wyatt Jeffrey R. , Bateman Robert H. , Green Brian N.
Published: July 2005

Massive cluster ions of CsI (mass-to-charge ratio > 25,000) have been produced, mass analyzed, and detected with a conventional double-focusing mass spectrometer. Variations in the ion intensity distributions depend on the relative lifetime of the ions. These results are of fundamental interest, but they also impact the practical limits of mass spectrometry.
Quantitative Surface Analysis by Fourier Transform Attenuated Total Reflection Infrared Spectroscopy
Authors: Iwamoto Reikichi , Ohta Koji
Published: July 2005

The Fourier transform infrared spectroscopic ATR (FT-IR-ATR) method has been applied to quantitative determination of chemical composition of thin surface layers. The powerful capability of the FT-IR-ATR spectral subtraction method was proved to determine poly(dimethylsiloxane) content in the surface layer of Cardiothane 51, which consists of poly(urethane) and poly(dimethylsiloxane) as a minor component, showing the detection limit of 0.2% of the content. An absorbance ratio of a selected band of poly(dimethylsiloxane) relative to a selected band of poly(urethane) was determined by FT-IR-ATR measurements on the pure samples of each of the constituting components that have the same area contacted onto the internal reflection element of Ge. Consideration was also given to the thickness of the surface layer that can be analyzed by the present method, and one half of the penetration depth dp was considered to better represent the thickness of the surface layer measured than dp.
Raman Spectroscopic Determination of the Integrity of Urea Inclusion Compounds
Authors: Casal Hector L.
Published: July 2005

Raman spectroscopy is shown to provide a rapid and definitive analysis of the nature of urea inclusion compounds. It is demonstrated that the photodecomposition of included alkanones does not destroy the urea lattice, but the inclusion compounds of n-decane are destroyed by ultrasonic agitation.
Analysis of the Effluent from a High Voltage Spark Discharge with a Microwave-Induced Plasma
Authors: Helmer Deborah J. C. , Walters J. P.
Published: July 2005

A high voltage spark discharge was used to sample ferrous alloy samples in a point-to-plane configuration. An enclosed Petry spark stand was used so that the effluent from the spark could be put into a microwave discharge sustained at 2450 MHz. The emission from the eroded metals in the microwave discharge was monitored with a PARC Vidicon detector. This method of detection provided spectral simplification and improved signal-to-background ratios up to six-fold over the emission observed from the spark discharge. The emission from the microwave was shown to be linear with concentration for many lines observed.
Raman Spectroscopic Evidence of Pressure-Induced Conformational Changes in Liquid Methylcyclohexane
Authors: Gardiner Derek J. , Bassi Gurmail S. , Galvin Gerry D. , Gorvin Anthony C. , Straughan Brian P.
Published: July 2005

Raman spectra have been obtained from liquid methylcyclohexane over a range of temperatures (–64°C + 64°C) and pressures (1 bar to 5 kbar). Comparison of the pattern of band intensity changes as a function of temperature and pressure indicates that an increase in pressure shifts the conformational equilibrium in the liquid to favor the equatorial form.
A Simple Method for Determining the Lower Critical Solution Temperature of Polymer Blends Using a Raman Spectrometer
Authors: Coleman M. M. , Skrovanek D. J. , Painter P. C.
Published: July 2005

The authors have an ongoing research interest in the application of Fourier transform infrared spectroscopy to the study of compatible polymer blend systems and, in particular, the role of intermolecular interactions in compatibilization. It was considered essential to obtain an independent measurement of the lower critical solution temperature (LCST) of the particular polymer blends used in our studies. Not having conventional light scattering equipment, it was decided to attempt to use our Raman spectrometer for these purposes. In this communication we describe the simple method employed and present preliminary results from three polymer blend systems. The results exceeded our expectations. The onset of phase separation is obvious, and the experimentally determined LCSTs are in accord with previously published data.
Physical Activity and Weight Loss Among Adults With Type 2 Diabetes and Overweight or Obesity
Authors: Huang Zihao , Zhuang Xiaodong , Huang Rihua , Liu Menghui , Xu Xinghao , Fan Ziyan , Dai Rongling , Li Hansheng , Xiong Zhenyu , Guo Yue , Liang Qi , Liao Xinxue
Published: February 2024

Importance

Prior findings from the Look AHEAD trial showed no significant reduction in the risk of cardiovascular events by lifestyle-induced weight loss among individuals with type 2 diabetes (T2D) and overweight or obesity. However, physical activity (PA) may modify the changes in cardiovascular risk associated with weight loss.

Objective

To examine the joint association of weight loss and PA with the risk of adverse cardiovascular events in patients with T2D and overweight or obesity.

Design, Setting, and Participants

This cohort study was a post hoc analysis of the Look AHEAD randomized clinical trial, which compared the cardiovascular effects of weight loss by intensive lifestyle intervention vs diabetes support and education among individuals with T2D and overweight or obesity. The study was conducted from June 2001 to September 2012, and participants were patients in the substudy of accelerometry-measured PA from 8 locations in the United States. Data were analyzed from June to August 2023.

Exposures

Body weight change and accelerometer-derived PA volume across the first 4 years.

Main Outcomes and Measures

The primary outcome was a composite cardiovascular outcome including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina.

Results

Among a total of 1229 participants (mean [SD] age, 60 [7] years; 533 male [43%]), 333 (27%) achieved and maintained weight loss for the first 4 years. Among the individuals who maintained weight loss, 105 (32%) maintained high PA volume. During a median of 9.5 years of follow-up, 198 participants (16.1%) experienced the primary outcome. Compared with those with low PA volume and no weight loss (105 [15.8%]), maintaining high PA volume and weight loss was associated with a 61% lower risk of the primary end point (hazard ratio, 0.39; 95% CI, 0.19-0.81; P = .01). However, there was no significant difference in the risk of the primary end point among those with either weight loss only or high PA only. The multiplicative interaction between weight loss and PA for the risk of cardiovascular events was also significant (P for interaction = .01).

Conclusions and Relevance

In this cohort study, maintaining weight loss and higher PA volume was associated with a lower risk of the composite cardiovascular outcome. The findings suggest that the cardiovascular benefits of PA may vary and be enhanced by weight loss among individuals with T2D and overweight or obesity.
Racial and Ethnic Differences in the Prevalence of Patients With Arthritis and Severe Joint Pain and Who Received Provider Counseling About Physical Activity for Arthritis Among Adults Aged 18 Years or Older—United States, 2019
Authors: Wise Akilah , Boring Michael A. , Odom Erica L. , Foster Anika L. , Guglielmo Dana , Master Hiral , Croft Janet B.
Published: February 2024

Objective

This study examined the racial and ethnic differences in individuals with self‐reported and doctor‐diagnosed arthritis, severe joint pain, and provider counseling for physical activity among US adults with arthritis.

Methods

We estimated prevalence by race and ethnicity among 31,997 adults aged ≥18 years in the 2019 National Health Interview Survey. We used multiple logistic regression models to investigate associations between outcomes and race and ethnicity.

Results

Compared with non‐Hispanic White adults (22.9%), we found a significantly higher age‐adjusted prevalence of arthritis among American Indian/Alaska Native adults (30.3%). Among adults with arthritis, higher age‐adjusted prevalence of severe joint pain among American Indian/Alaska Native (39.1%), non‐Hispanic Black (36.4%), and Hispanic adults (35.7% vs 22.5% [White]) and higher provider counseling for physical activity among non‐Hispanic Black adults (58.9% vs 52.1% [White]) were observed and could not be fully explained by differences in socioeconomic factors, body mass index, depression history, and comorbid conditions. Additional models also containing inability to pay medical bills and food insecurity did not explain racial and ethnic differences.

Conclusion

Our findings highlight a need for multilevel interventions to mitigate social and environmental barriers to physical activity and eliminate disparities in individuals with arthritis and severe joint pain.
Er‐Doped MgAl2O4 Nanofilms Enabling Highly Efficient Near‐Infrared Electroluminescence from the Silicon‐Based MOS Devices Fabricated by Atomic Layer Deposition
Authors: Yu Zhimin , Guo Xinliang , Yan Zengxin , Yang Yang , Sun Jiaming
Published: February 2024

Er3+‐doped polycrystalline MgAl2O4 (MAO:Er) spinel nanofilms are deposited via atomic layer deposition, and the metal‐oxide–semiconductor light emitting devices are fabricated. The crystallinity and morphology of the MAO:Er nanofilms are explored by modifying the annealing temperatures, Al2O3/MgO ratios and Er2O3 dopant cycles. The similar electroluminescence (EL) emissions peaking at 1530 nm indicates the identical crystal field environment for the doped Er3+ ions. The concentration quenching is verified to occurs via the energy transfer among the neighboring Er3+ ions. The optimal device (800 °C‐annealed, Al2O3/MgO ratio close to stoichiometry, Er3+: 1.85 mol%) yields the highest external quantum efficiency of 28%, the power efficiency of 0.32% and the optical power density of 14.62 mW cm−2. The smooth MAO:Er spinel nanofilms with the low refractive index and high resistance ensure the highly efficient light extraction and the generation of energetic electrons for the impact excitation of Er3+ ions. The trap‐assisted tunneling under operation electric field dominates the conduction mechanism for the EL emissions. The estimated decay lifetime of 1154.4 µs and a large‐stimulated emission cross‐section in the order of 10−15–10−14 cm2 are revealed from the EL emissions. Intense near‐infrared emissions from these Si‐based MAO:Er devices have great potential in the optoelectronic applications.
Comparison of fatigue and functional status in elderly type 2 diabetes patients versus age and gender matched individuals
Authors: Bhatt Priyal P. , Sheth Megha S.
Published: February 2024

Introduction

Fatigue is a common yet not frequently explored complication of diabetes. There are fewer studies available on the impact of diabetes on the severity of fatigue and the functional status of patients.

Methods

Fifty individuals meeting the inclusion criteria were included. The individuals were divided into two groups: group A (diabetic elderly individuals) and group B (nondiabetic age and gender‐matched individuals). An observational analytical study was conducted. Outcome measures used were: fatigue severity scale (FSS), lower extremity functional scale (LEFS), 6‐minute walk distance (6MWD), and 30‐second chair stand test. SPSS 16 was used to analyze data.

Results

As per the normality test, a between‐group comparison of fatigue severity scale (FSS) score, chair stand test score, and LEFS score was carried out by a nonparametric Mann–Whitney test, which showed a statistically significant difference between the groups (P < 0.05). Between‐group comparison of 6MWD was carried out by parametric unpaired t test. The results showed a statistically significant difference in the distance walked by both groups.

Conclusion

Higher levels of fatigue and impaired functional status along with reduced strength and function of lower limbs was seen in elderly patients with type 2 diabetes Inclusion of symptom assessment and strategies to reduce the burden of fatigue in diabetes patient should be incorporated.
Dynamic Reconstruction of Two‐Dimensional Defective Bi Nanosheets for Efficient Electrocatalytic Urea Synthesis
Authors: Wang Yan , Xia Shuai , Cai Rui , Zhang Jianfang , Yu Cuiping , Cui Jiewu , Zhang Yong , Wu Jingjie , Wu Yucheng
Published: February 2024

Abstract:Catalyst surface dynamics drive the generation of active species for electrocatalytic reactions. Yet, the understanding of dominant site formation and reaction mechanisms is limited. In this study, we thoroughly investigate the dynamic reconstruction of two‐dimensional defective Bi nanosheets from exfoliated Bi2Se3 nanosheets under electrochemical CO2 and nitrate (NO3−) reduction conditions. The ultrathin Bi2Se3 nanosheets obtained by NaBH4‐assisted cryo‐mediated liquid‐phase exfoliation are more easily reduced and reconstructed to Bi nanosheets with high‐density grain boundaries (GBs; GB‐rich Bi). The reconstructed GB‐rich Bi catalyst affords a remarkable yield rate of 4.6 mmol h−1 mgcat.−1 and Faradaic efficiency of 32 % for urea production at −0.40 V vs. RHE. Notably, this yield rate is 2 and 8.2 times higher than those of the low‐GB Bi and bulk Bi catalysts, respectively. Theoretical analysis demonstrates that the GB sites significantly reduce the *CO and *NH2 intermediate formation energy and C−N coupling energy barrier, enabling selective urea electrosynthesis on the GB‐rich Bi catalyst. This work will trigger further research into the structure‐activity interplay in dynamic processes using in situ techniques.
Triply Selective & Sequential Diversification at Csp3: Expansion of Alkyl Germane Reactivity for C−C & C−Heteroatom Bond Formation
Authors: Ahrweiler Eric , Schoetz Markus D. , Singh Gurdeep , Bindschaedler Quentin P. , Sorroche Alba , Schoenebeck Franziska
Published: February 2024

We report the triply selective and sequential diversification of a single Csp3 carbon carrying Cl, Bpin and GeEt3 for the modular and programmable construction of sp3‐rich molecules. Various functionalizations of Csp3−Cl and Csp3−BPin (e.g. alkylation, arylation, homologation, amination, hydroxylation) were tolerated by the Csp3−GeEt3 group. Moreover, the methodological repertoire of alkyl germane functionalization was significantly expanded beyond the hitherto known Giese addition and arylation to alkynylation, alkenylation, cyanation, halogenation, azidation, C−S bond formation as well as the first demonstration of stereo‐selective functionalization of a Csp3‐[Ge] bond.
Insight into the d–p Orbital Hybridization of Ru and B Dispersed g‐C3N4 Catalysts for Nitrogen Reduction Reaction
Authors: Zhang Ji , Liu Daojun , Yu Aimin , Li Dongsheng , Zhou Songlin , Sun Chenghua
Published: February 2024

Electrochemical nitrogen reduction reaction (NRR) is considered as an important strategy for ammonia using green energy. Single atom catalysts (SACs) with a metal atom as active site have been shown its advantages to high ammonia yield and low energy consumption. In this work, we proposed a new concept of SACs with the capacity of d‐p orbital hybridization. These computationally designed SACs contained a metal and non‐metal pair anchored on g‐C3N4 slab. Among these SACs studied in the present work, RuB@g‐C3N4 catalyst performed the best activity for NRR with low onset potential of −0.33 V by a two‐step scanning computations using density functional theory (DFT). Moreover, suppressing effectively to the competitive hydrogen evolution reaction (HER) also make it more selective. It was further revealed that the hybridization of d‐p orbitals between metal and nonmetal could regulate the electronics of active sites and facilitate the adsorption and charge transfer of adsorbed N2 molecules resulting in enhanced catalytic performance. This work demonstrated an alternative way to further enhance the catalytic activity of SACs by introducing a non‐metal atom.
Quantitative image analysis pipeline for detecting circulating hybrid cells in immunofluorescence images with human‐level accuracy
Authors: Heussner Robert T. , Whalen Riley M. , Anderson Ashley , Theison Heather , Baik Joseph , Gibbs Summer , Wong Melissa H. , Chang Young Hwan
Published: February 2024

Circulating hybrid cells (CHCs) are a newly discovered, tumor‐derived cell population found in the peripheral blood of cancer patients and are thought to contribute to tumor metastasis. However, identifying CHCs by immunofluorescence (IF) imaging of patient peripheral blood mononuclear cells (PBMCs) is a time‐consuming and subjective process that currently relies on manual annotation by laboratory technicians. Additionally, while IF is relatively easy to apply to tissue sections, its application to PBMC smears presents challenges due to the presence of biological and technical artifacts. To address these challenges, we present a robust image analysis pipeline to automate the detection and analysis of CHCs in IF images. The pipeline incorporates quality control to optimize specimen preparation protocols and remove unwanted artifacts, leverages a β‐variational autoencoder (VAE) to learn meaningful latent representations of single‐cell images, and employs a support vector machine (SVM) classifier to achieve human‐level CHC detection. We created a rigorously labeled IF CHC data set including nine patients and two disease sites with the assistance of 10 annotators to evaluate the pipeline. We examined annotator variation and bias in CHC detection and provided guidelines to optimize the accuracy of CHC annotation. We found that all annotators agreed on CHC identification for only 65% of the cells in the data set and had a tendency to underestimate CHC counts for regions of interest (ROIs) containing relatively large amounts of cells (>50,000) when using the conventional enumeration method. On the other hand, our proposed approach is unbiased to ROI size. The SVM classifier trained on the β‐VAE embeddings achieved an F1 score of 0.80, matching the average performance of human annotators. Our pipeline enables researchers to explore the role of CHCs in cancer progression and assess their potential as a clinical biomarker for metastasis. Further, we demonstrate that the pipeline can identify discrete cellular phenotypes among PBMCs, highlighting its utility beyond CHCs.
Fungal communities associated with early immature tubers of wild Gastrodia elata
Authors: Li Dong , Jin Xiao‐Han , Li Yu , Wang Yu‐Chuan , He Hai‐Yan , Zhang Han‐Bo
Published: February 2024

Full myco‐heterotrophic orchid Gastrodia elata Bl. is widely distributed in Northeast Asia, and previous research has not fully investigated the symbiotic fungal community of its early immature tubers. This study utilized Illumina sequencing to compare symbiotic fungal communities in natural G. elata immature tubers and their habitats. LEfSe (Linear Discriminant Analysis Effect Size) was used to screen for Biomarkers that could explain variations among different fungal communities, and correlation analyses were performed among Biomarkers and other common orchid mycorrhizal fungi. Our results illustrate that the symbiotic fungal communities of immature G. elata tubers cannot be simply interpreted as subsets of the environmental fungal communities because some key members cannot be traced back to the environment. The early growth of G. elata was related to a small group of fungi, such as Sebacina, Thelephora, and Inocybe, which were also common mycorrhizal fungi from other orchids. In addition, Mycena, Auricularia, and Cryptococcus were unique fungal partners of G. elata, and many new species have yet to be discovered. Possible symbiotic Mycena should be M. plumipes and its sibling species in this case. Our results provide insight into the symbiotic partner switch and trophic pattern change during the development and maturation of G. elata.
Among‐individual behavioural variation in the ornamental red cherry shrimp, Neocaridina heteropoda
Authors: Rickward Rosie Ann , Santostefano Francesca , Wilson Alastair James
Published: February 2024

Personality variation, defined as among‐individual differences in behaviour that are repeatable across time and context, is widely reported across animal taxa. From an evolutionary perspective, characterising the amount and structure of this variation is useful since differences among individuals are the raw material for adaptive behavioural evolution. However, behavioural variation among individuals also has implications for more applied areas of evolution and ecology—from invasion biology to ecotoxicology and selective breeding in captive systems. Here, we investigate the structure of personality variation in the red cherry shrimp, Neocaridina heteropoda, a popular ornamental species that is readily kept and bred under laboratory conditions and is emerging as a decapod crustacean model across these fields, but for which basic biological, ecological and behavioural data are limited. Using two assays and a repeated measures approach, we quantify behaviours putatively indicative of shy–bold variation and test for sexual dimorphism and/or size‐dependent behaviours (as predicted by some state‐dependent models of personality). We find moderate‐to‐high behavioural repeatabilities in most traits. Although strong individual‐level correlations across behaviours are consistent with a major personality axis underlying these observed traits, the multivariate structure of personality variation does not fully match a priori expectations of a shy–bold axis. This may reflect our ecological naivety with respect to what really constitutes bolder, more risk‐prone, behaviour in this species. We find no evidence for sexual dimorphism and only weak support for size‐dependent behaviour. Our study contributes to the growing literature describing behavioural variation in aquatic invertebrates. Furthermore, it lays a foundation for further studies harnessing the potential of this emerging model system. In particular, this existing behavioural variation could be functionally linked to life‐history traits and invasive success and serve as a target of artificial selection or bioassays. It thus holds significant promise in applied research across ecotoxicology, aquaculture and invasion biology.
Temperature and nutrients alter the relative importance of stochastic and deterministic processes in the coastal macroinvertebrates biodiversity assembly on long‐time scales
Authors: Wan Xuhao , Fang Yuan , Jiang Yueming , Lu Xueqiang , Zhu Lin , Feng Jianfeng
Published: February 2024

Macroinvertebrates play a vital role in coastal ecosystems and are an important indicator of ecosystem quality. Both anthropogenic activity and environmental changes may lead to significant changes in the marine macroinvertebrate community. However, the assembly process of benthic biodiversity and its mechanism driven by environmental factors at large scales remains unclear. Here, using the benthic field survey data of 15 years at large spatial and temporal scales from the Yellow Sea Large Marine Ecosystem, we investigated the relative importance of environmental selection, dispersal processes, random‐deterministic processes of macroinvertebrates community diversity assembly, and the responses of this relative importance driven by temperature and nutrients. Results showed that the macroinvertebrates community diversity is mainly affected by dispersal. Nitrogen and phosphorus are the most important negative factors among environmental variables, while geographical distance is the main limiting factor of β diversity. Within the range of 0.35–0.70 mg/L of nutrients, increasing nutrient concentration can significantly facilitate the contribution of the decay effect to β diversity. Within the temperature range studied (15.0–18.0°C), both warming and cooling can lead to a greater tendency for species diversity assembly processes to be dominated by deterministic processes. The analysis contributes to a better understanding of the assembly process of the diversity of coastal marine macroinvertebrates communities and how they adapt to global biogeochemical processes.
The association between vertebral artery hypoplasia and fetal‐type variants of the posterior cerebral artery with imaging findings among patients with posterior circulation stroke: A single‐center cross‐sectional study
Authors: Layegh Parvaneh , Jarahi Lida , Hassannejad Ehsan , Arab Marziye
Published: February 2024

Background and Aim

The present study investigated the correlation between vertebral artery hypoplasia and fetal‐type variations of posterior cerebral arteries with stroke patterns and imaging findings in individuals with posterior circulation ischemic stroke.

Methods

In this cross‐sectional study, patients with symptoms of acute ischemic stroke in the posterior circulation system referred to Ghaem Hospital in Mashhad between 2016 and 2022 were investigated. Demographic data, including age, gender, systemic diseases, history of previous stroke or transient ischemic attacks, and clinical manifestations of patients, were recorded using questionnaires and checklists from patient files. The results of imaging studies, including magnetic resonance imaging and computed tomography angiography, were also recorded. The obtained data were analyzed by SPSS statistical software.

Results

Among 974 patients suffering from posterior circulation ischemic stroke, 155 patients with an average age of 60.44 ± 13.95 years were included in the study, out of which 97 patients (62.6%) were male. Unilateral vertebral artery hypoplasia on the right, left, and bilateral hypoplasia was present in 67 (43.2%), 35 (22.6%), and 5 (3.2%) patients, respectively. There were complete unilateral fetal origin on the right in 38 (24.5%), complete unilateral on the left in 12 (7.7%), partial unilateral on the right in 12 (7.7%), partial unilateral on the left in 6 (3.9%), complete bilateral in 14 (9%), and partial bilateral in 8 (5.2%) patients. There was no significant relationship between vertebral artery hypoplasia and PCA fetal‐type variants with different ischemia locations and infarct patterns (p > 0.05). Also, there was no significant relationship between the age and gender of patients with ischemia location and infarct pattern (p > 0.05).

Conclusion

Despite previous evidence showing a relation between vertebral artery hypoplasia and PCA fetal‐type variants as risk factors for PC stroke, the present study did not establish a significant correlation between these factors and the location of ischemia and infarct patterns.
Health‐related quality of life (HRQoL) and associated factors in Bangladeshi adolescents during COVID‐19
Authors: Anjum Afifa , Mousum Sabrina , Ratan Zubair Ahmed , Salwa Marium , Khan Md Maruf H. , Islam Mohammad Tanvir , Arafat S. M. Yasir , Haque M. Atiqul
Published: February 2024

Background and Aims

The COVID‐19 pandemic and its accompanying countermeasures significantly disrupt the health‐related quality of life (HRQoL) of adolescents. We aimed to estimate the status and associated factors related to HRQoL of adolescents during the COVID‐19 pandemic from the community population of Bangladesh.

Methods

This cross‐sectional study followed two‐stage sampling. From eight administrative divisions of Bangladesh, 2030 adolescents were enrolled. The KIDSCREEN‐10 index was used to measure the HRQoL of adolescents. In addition to this, adolescents' data on sociodemographics, mental well‐being, parenting style, insomnia, food insecurity, depression, anxiety and stress, resilient coping, screen‐based activity, and anthropometry were taken for finding out the factors associated with HRQoL of adolescents. The hierarchical multilinear regression was performed to assess the association.

Results

More than 47% of adolescents were found to have moderate and high HRQoL, while 4.7% of adolescents experienced low HRQoL during data collection. Higher age (B: −0.671), having more siblings (B: −0.316), food insecurity (B: ‒2.010), depression (B: ‒0.321), anxiety (B: ‒0.362), and stress (B: ‒0.150) were found to have significantly negative associations with adolescents' HRQoL during the COVID‐19 pandemic. Whereas, positive parenting (B: 0.409), inconsistent parenting discipline (B: 0.266), good mental health (B: 5.662), resilient coping (B: 0.306) were found to have significant positive relationships.

Conclusions

The findings from this study indicate that over 52% of the adolescents reported a moderate and lower level of HRQoL. In light of these results, it may be beneficial to prioritize interventions targeting psychological factors such as depression, anxiety, and stress.
Dietary Intakes of Young Children with Cystic Fibrosis: Is There a Difference?
Authors: Bentur L. , Kalnins D. , Levison H. , Corey M. , Durie P. R.
Published: February 2024

Caloric intakes of preadolescent and adolescent girls and boys with cystic fibrosis (CF) were compared in order to evaluate the possibility that poor caloric intake contributes to poor nutritional status and high mortality among girls with CF. Fifty‐six CF patients (26 girls and 30 boys), 10‐15 years old, completed a 3‐day food record, answered a short questionnaire, and underwent anthropometric and pulmonary function assessment. The mean ages of the girls and boys were similar, but the height and weight percentiles of the girls were lower than those of the boys (p = 0.02). Mean caloric intakes were no different (116% and 112% of the recommended nutrient intake in the girls and boys, respectively). Nutritional status, as determined by weight as a percentage of ideal weight for height, mean triceps skinfold thickness, and midarm muscle circumference, was normal and similar in both sexes. Most girls and boys with CF in this study had an appropriate perception of their body weight. Pulmonary function tests suggested mild lung disease with no significant difference between girls and boys (forced expiratory volume in 1 s of 82.2% and 79.8% of predicted values, respectively). The similar nutritional and pulmonary status of the girls and boys with CF in this age group is in contrast to previous reports. This finding may be the result of our policy, introduced >15 years ago, of expecting normal growth, by paying close attention to enzyme therapy and encouraging high energy intake from the time of diagnosis. It remains to be seen whether boys and girls continue to maintain similar nutritional and pulmonary status at a later age and whether both sexes experience a similar mortality rate as they age.