bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucosamine amends CNS pathology in mucopolysaccharidosis IIIC mouse expressing misfolded HGSNAT
Authors: Pan Xuefang , Taherzadeh Mahsa , Bose Poulomee , Heon-Roberts Rachel , Nguyen Annie L.A. , Xu TianMeng , Pará Camila , Yamanaka Yojiro , Priestman David A. , Platt Frances M. , Khan Shaukat , Fnu Nidhi , Tomatsu Shunji , Morales Carlos R. , Pshezhetsky Alexey V.
Published: June 2022

The majority of mucopolysaccharidosis IIIC (MPS IIIC) patients have missense variants causing misfolding of heparan sulfate acetyl-CoA:α-glucosaminide N-acetyltransferase (HGSNAT), which are potentially treatable with pharmacological chaperones. To test this approach, we generated a novel HgsnatP304L mouse model expressing misfolded HGSNAT Pro304Leu variant. HgsnatP304L mice present deficits in short-term and working/spatial memory 2–4 mo earlier than previously described constitutive knockout Hgsnat-Geo mice. HgsnatP304L mice also show augmented severity of neuroimmune response, synaptic deficits, and neuronal storage of misfolded proteins and gangliosides compared with Hgsnat-Geo mice. Expression of misfolded human Pro311Leu HGSNAT protein in cultured hippocampal Hgsnat-Geo neurons further reduced levels of synaptic proteins. Memory deficits and majority of brain pathology were rescued in mice receiving HGSNAT chaperone, glucosamine. Our data for the first time demonstrate dominant-negative effects of misfolded HGSNAT Pro304Leu variant and show that they are treatable by oral administration of glucosamine. This suggests that patients affected with mutations preventing normal folding of the enzyme can benefit from chaperone therapy.
Electron impact excitation of the Tl
+
ion: resonance and cascade transitions
Authors: Roman Viktoria , Gomonai Aleksandr I , Sharma Lalita , Sahoo Aloka Kumar , Gomonai Anna N
Published: June 2022

Results of experimental and theoretical investigations into the electron-impact excitation of the resonance

6
s
6

p

1

P
1

°

→ 6s
2
1
S
0 (132.2 nm), as well as the cascade 6s7s
1
S
0 →

6
s
6

p

1

P
1

°

(309.2 nm) and 6p
2
1
D
2 →

6
s
6

p

1

P
1

°

(150.8 nm) spectral transitions from the ground 6s
2
1
S
0 level in the thallium ion, are presented. Crossed beams of electrons and Tl+ ions in combination with a spectroscopic method were used in the experiment. Measured cross sections have a distinct resonance structure arising mainly from the electron decay of atomic 5d
96s
26p
2, 5d
106s7s(1
S)np (n ⩾ 7), 5d
106s6d(1
D)np (n ⩾ 6), 5d
106s6d(1
D)nd (n ⩾ 6) and ionic 5d
96s
2
np, 5d
96s
2
nd, 5d
96snp (n ⩾ 6) autoionizing levels, as well as radiative transitions from the higher 6s7s
1
S
0, 6s6d
1
D
2, and 6p
2
1
D
2, 1
S
0 ionic levels. Relativistic distorted wave (RDW) calculations are performed to obtain the effective cross sections for the above transitions. The absolute values of the cross sections are found to be 1.39 × 10−16 cm2 at 300 eV for the λ132.2 nm resonance line, and 0.11 × 10−16 cm2 and 0.56 × 10−16 cm2 at 100 eV for the λ309.2 nm and λ150.8 nm lines, respectively. The contribution of the cascade transitions being studied to the effective cross section of the λ132.2 nm resonance line at the energy of 100 eV is about 30%. A calculation using the semi-empirical Van Regemorter formula is also performed to obtain the effective cross section of the resonance λ132.2 nm line. The absolute value of the cross section at 300 eV is found to be nearly the same as that given by the RDW calculation.
Modelling and experimental evidence of the cathode erosion in a plasma spray torch
Authors: Baeva M , Benilov M S , Zhu T , Testrich H , Kewitz T , Foest R
Published: June 2022

The lifetime of tungsten cathodes used in plasma spray torches is limited by processes leading to a loss of cathode material. It was reported in the literature that the mechanism of their erosion is the evaporation. A model of the ionization layer of a cathode is developed to study the diffusive transport of evaporated tungsten atoms and tungsten ions produced due to ionization by electron impact in a background argon plasma. It is shown that the Stefan–Maxwell equations do not reduce to Fick law as one could expect for the transport of diluted species, which is due to significant diffusion velocities of argon ions. The ionization of tungsten atoms occurs in a distance of a few micrometers from the cathode surface and leads to a strong sink, which increases the net flux of tungsten atoms far beyond that obtained in absence of tungsten ions. This shows that the tungsten ions are driven by the electric field towards the cathode resulting in no net diffusive flux and no removal of tungsten species from the ionization layer even if convection is accounted for. A possible mechanism of removal is found by extending the model to comprise an anode. The extended model resolves the inter-electrode region and provides the plasma parameters for a current density corresponding to the value at the center of the cathode under typical arc currents of 600 A and 800 A. The presence of the anode causes a reversal of the electric field on the anode side, which pulls the ions away from the ionization layer of the cathode. The net flux of tungsten ions can be further fortified by convection. This model allows one to evaluate the loss of cathode material under realistic operating conditions in a quantitative agreement with measured values.
Propagation dynamics of the solid–liquid interface in Ge upon ns and fs laser irradiation
Authors: Casquero Noemi , Ruiz de Galarreta Carlota , Fuentes-Edfuf Yasser , Solis Javier , Wright C David , Siegel Jan
Published: June 2022

Monitoring the laser-induced melting and solidification dynamics of Ge upon laser irradiation is an enormous challenge due to the short penetration depth of its liquid phase. In this work, real-time pump-probe experiments in combination with finite element calculations have been employed to investigate the melting and solidification dynamics of germanium upon ns and fs laser pulse irradiation (λ = 800 nm). Excellent agreement between experiments and simulations allowed us to indirectly determine additional time- and depth-dependent information about the transformation dynamics of germanium, including the thickness evolution of the molten layer, as well as its melting and solidification velocities for the two pulse durations for different fluences. Our results reveal considerable differences in the maximum thickness of the molten Ge superficial layers at sub-ablative fluences for ns and fs pulses, respectively. Maximum melt-in velocities of 39 m s−1 were obtained for ns pulses at high fluences, compared to non-thermal melting of a thin layer within 300 fs for fs pulses already at moderate fluences. Maximum solidification velocities were found to be 16 m s−1 for ns pulses, and up to 55 m s−1 for fs pulses. Weak signs of amorphization were observed for fs excitation, suggesting that the lower limit of solidification velocities for a complete amorphization is above 55 m s−1. In addition, we show high precision measurements of the melt-in velocities over the first 20 nm by means of fs microscopy with sub-ps temporal resolution. Here, differences of the melt-in process of several orders of magnitude were observed, ranging from virtually instantaneous melting within less than 2 ps even for a moderate peak fluence up to 200 ps for fluences close to the melting threshold.
Effect of nanodisperse powders on the spreading and crystallization of a metal drop on a porous substrate
Authors: Cherepanov A N , Cherepanova V K , Bublik V V
Published: June 2022

The influence of modifying nanopowders on the spreading and crystallization of a nickel droplet on a porous steel substrate is analyzed. For this purpose, a model has been developed for the spreading of a drop of liquid metal after its high-speed collision with a heated porous substrate. Due to the high impact velocity, the process of metal crystallization is considered after the complete spreading of the drop using the model of heterogeneous nucleation and macroscopic growth of the solid phase, taking into account the size and capillary effects. The influence of the impact velocity and substrate porosity on the thickness and diameter of the formed splat, the penetration depth, and the volume of liquid that penetrated the substrate has been studied. The numerical study of heterogeneous crystallization of a metal drop has made it possible to evaluate the influence of the modifying nanoparticle parameters, the impact velocity, and substrate porosity on the heterogeneous nucleation and on the resulting splat macrostructure.
Radiation exposure to the lens of the eye for Japanese nuclear power plant workers
Authors: Yokoyama Sumi , Tatsuzaki Hideo , Tanimura Yoshihiko , Yoshitomi Hiroshi , Hirao Shigekazu , Aoki Katsunori , Tachiki Shuichi , Ezaki Iwao , Hoshi Katsuya , Tsujimura Norio
Published: June 2022

In Japan, the radiation-dose limit for the lens of the eye was revised in April 2021. Consequently, for workers, the numerical values of the equivalent dose to the lens of the eye are equal to those of the effective dose. Radiation workers, radiation safety officers and licensees must comply with regulations related to radiation protection and optimize protection. The new guidelines on dose monitoring of the lens of the eye developed by the Japan Health Physics Society recommend for the dose to be estimated near the eye for accurate estimation, when the dose to the lens approaches or exceeds the management criteria. However, there is limited information regarding the non-uniform exposure of nuclear power plant workers. In this study, the dose equivalents of high-dose-rate workplaces and the personal doses of 88 workers were estimated at four Japanese commercial nuclear power plant sites (RWR: 3 units and BWR: 3 units) and the dose to the lens of the eye and the exposure situations of the workers were analyzed.
ESDDNet: efficient small defect detection network of workpiece surface
Authors: Chen Guodong , Xu Feng , Liu Guihua , Chen ChunMei , Liu Manlu , Zhang Jing , Niu Xiaoming
Published: June 2022

Defect detection of a workpiece surface is a basic and essential task in the production of products. Although significant progress has been made in workpiece surface defect detection, traditional methods still find it difficult to detect small defects efficiently. To deal with this problem, we propose an efficient small defect detection network with a novel parallel convolution module, serial convolution module and feature fusion module. First, a lightweight backbone network is used to extract the preliminary defect features. Second, the parallel convolution module and serial convolution module are used to obtain the abundant defect features. Then, the feature fusion module is used to fuse the shallow features with deep features, to enhance the features of the small defects. Finally, the obtained features are put into the corresponding detection head to get the final prediction results. The experimental results on a local cable dataset and a public printed circuit board dataset show that our method achieves a remarkable performance in detecting small defects and achieves a favorable trade-off between accuracy, speed and model size, which meets the requirements of industrial applications.
Mechanical health indicator construction and similarity remaining useful life prediction based on natural language processing model
Authors: Duan Yuhang , Li Honghui , Zhang Ning
Published: June 2022

Remaining useful life (RUL) prediction, as an essential task for prediction and health management, can improve the reliability of degradation systems. In this paper, multi-dimensional mechanical monitoring readings are treated as natural language sequences and inputted to a natural language processing model, Transformer, to extract semantic compression vectors. The health indicators (HIs) are constructed from the changes of compressed semantic vectors during the mechanical system operation, reflecting the mechanical health status at each monitoring point. Subsequently, combined with the similarity matching method, the RUL prediction is achieved by weighted summation. Transformer mainly consists of attention layers and residual connection layers, which contain no recurrence and convolution. The attention layer can highlight the critical time step information during the HI construction. Moreover, the output of different time steps can be obtained simultaneously in a parallel computation manner. The proposed scheme is conducted on two publicly available datasets for experimental and evaluation metrics comparison. The experimental results show that the proposed scheme can achieve competitive prediction results, with some of the metrics reaching the highest. An autoencoder only containing attention mechanism can effectively extract degradation feature representations for the adaptive construction of unsupervised HIs.
Detection of arrhythmia in 12-lead varied-length ECG using multi-branch signal fusion network
Authors: Dong Yanfang , Cai Wenqiang , Qiu Lishen , Guo Yunbo , Chen Yuhang , Zhang Miao , Wang Duoduo , Zhang Huimin , Wang Lirong
Published: June 2022

Objective. Automatic detection of arrhythmia based on electrocardiogram (ECG) plays a critical role in early prevention and diagnosis of cardiovascular diseases. With the increase in widely available digital ECG data and the development of deep learning, multi-class arrhythmia classification based on automatic feature extraction of ECG has become increasingly attractive. However, the majority of studies cannot accept varied-length ECG signals and have limited performance in detecting multi-class arrhythmias. Approach. In this study, we propose a multi-branch signal fusion network (MBSF-Net) for multi-label classification of arrhythmia in 12-lead varied-length ECG. Our model utilizes the complementary power between different structures, which include Inception with depthwise separable convolution (DWS-Inception), spatial pyramid pooling (SPP) Layer, and multi-scale fusion Resnet (MSF-Resnet). The proposed method can extract features from each lead of 12-lead ECG recordings separately and then effectively fuse the features of each lead by integrating multiple convolution kernels with different receptive fields, which can achieve the information of complementation between different angles of the ECG signal. In particular, our model can accept 12-lead ECG signals of arbitrary length. Main results. The experimental results show that our model achieved an overall classification F1 score of 83.8% in the 12-lead ECG data of CPSC-2018. In addition, the F1 score of the MBSF-Net performed best among the MBF-Nets which are removed the SPP layer from MBSF-Net. In comparison with the latest ECG classification algorithms, the proposed model can be applied in varied-length signals and has an excellent performance, which not only can fully retain the integrity of the original signals, but also eliminates the cropping/padding signal beforehand when dealing with varied-length signal database. Significance. MBSF-Net provides an end-to-end multi-label classification model with outperfom performance, which allows detection of disease in varied-length signals without any additional cropping/padding. Moreover, our research is beneficial to the development of computer-aided diagnosis.
Classification of multi-lead ECG with deep residual convolutional neural networks
Authors: Cai Wenjie , Liu Fanli , Xu Bolin , Wang Xuan , Hu Shuaicong , Wang Mingjie
Published: June 2022

Objective. Automatic electrocardiogram (ECG) interpretation based on deep learning methods is attracting increasing attention. In this study, we propose a novel method to accurately classify multi-lead ECGs using deep residual neural networks. Approach. ECG recordings from seven different open databases were provided by PhysioNet/Computing in Cardiology Challenge 2021. All the ECGs were pre-processed to obtain the same sampling rate. The label inconsistency among the databases was corrected by adding or removing specific labels. A label mask was created to filter out potentially incorrectly labelled data. Five models based on deep residual convolutional neural networks were optimized using an asymmetric loss function to classify multi-lead ECGs. Main results. The proposed method achieved an official challenge score of 0.54, 0.52, 0.50, 0.51, and 0.50 on twelve-lead, six-lead, four-lead, three-lead, and two-lead ECG test sets, respectively. These scores were ranked 5th, 3rd, 7th, 5th and 7th, respectively, in the challenge. Significance. The proposed method can correct the differential labeling tendency of databases from different sources and exhibits good generalization for classifying multi-lead ECGs in the hidden test set. The proposed models have the potential for clinical applications.
Key aspects of the past 30 years of protein design
Authors: Magi Meconi Giulia , Sasselli Ivan R , Bianco Valentino , Onuchic Jose N , Coluzza Ivan
Published: June 2022

Proteins are the workhorse of life. They are the building infrastructure of living systems; they are the most efficient molecular machines known, and their enzymatic activity is still unmatched in versatility by any artificial system. Perhaps proteins’ most remarkable feature is their modularity. The large amount of information required to specify each protein’s function is analogically encoded with an alphabet of just ∼20 letters. The protein folding problem is how to encode all such information in a sequence of 20 letters. In this review, we go through the last 30 years of research to summarize the state of the art and highlight some applications related to fundamental problems of protein evolution.
Resonant hyper-Raman scattering of light by LO phonons in wurtzite semiconductors
Authors: Semenova Ludmila E
Published: June 2022

Theoretical treatment of resonant hyper-Raman scattering of light by LO phonons in wurtzite semiconductors is given. The hyper-Raman process was considered for the scattering geometry y(xxz)x at which it involves the two-photon transitions to the B and C excitons of the s-type. Allowance was made for different sequences of intermediate virtual states. On the example of a CdS crystal the influence of the possible dipole transitions to the deeper valence band on the frequency dependence of the scattering cross section was investigated.
Laser analysis of the exhaled air isotope composition in diagnosing nosologically different H. pylori-associated diseases
Authors: Stepanov Eugene V , Ivashkin Vladimir T
Published: June 2022

Laser spectroscopic analysis of the isotope composition of exhaled air was performed for diagnosing the digestive system diseases, associated with Helicobacter pylori infection. An analyzer of 13СО2/12СО2 ratio in exhaled air based on tunable diode lasers and 13С-urea breath test (13С-UBT) were used to diagnose the infection. Nosologically different gastro-intestinal tract diseases: gastric and duodenal ulcer, gastritis and duodenitis were studied. The data of morphologic analysis of the gastric and duodenal mucosa, obtained during fibreoptic gastroduodenoscopyfor 612 patientshave been compared with the results of isotope breath test. The dependence has been analysed of laser 13С-UBT results on nosology and localisation of the H. pylori colony.
A new insight of specification error in regression: Excluding education variable from a model
Authors: Setyadharma A , Bowo P A , Suseno D A
Published: June 2022

The aim of this study is to show specification error in a model that exclude a relevant independent variable. Literature suggests that human capital features, such as education, must be considered in studies of social problems, such as environmental degradation. Therefore, the absence of education variable in a multiple regression equation model that explain the determinants of environmental degradation may result in model misspecification. Firstly, this study constructs a model with four variables, i.e.: unemployment level (ULEVEL), poor areas (POOR_AREAS), income inequality (INEQ) and access to electricity (ELEC), that may affect environmental quality in Indonesia. Secondly, this study examines the second model when education variable is included in the model. This study uses panel data regression method from 33 provinces in Indonesia during 2012 to 2018. The results of the first model show that all four control variables are statistically significant. However, ELEC’s coefficient has unexpected sign. When education variable is added to the second model, ELEC’s coefficient has expected sign. In conclusion, education variable is theoretically and empirically important variable to explain the changes in the quality of environment in Indonesia and education variable should be used in the model to avoid specification error in a model.
Shift in controlling factors of carbon stocks across biomes on the Qinghai-Tibetan Plateau
Authors: Han Daorui , Hu Zhongmin , Wang Xuhui , Wang Tao , Chen Anping , Weng Qihao , Liang Minqi , Zeng Xiang , Cao Ruochen , Di Kai , Luo Dengnan , Zhang Guangru , Yang Yuanhe , He Honglin , Fan Jiangwen , Yu Guirui
Published: June 2022

The Qinghai-Tibetan Plateau (TP) accumulated a large amount of organic carbon, while its size and response to environmental factors for the whole area remain uncertain. Here, we synthesized a dataset to date with the largest data volume and broadest geographic coverage over the TP, composing of 7196 observations from multiple field campaigns since the 1980s, and provided a comprehensive assessment of the size and spatial distribution of carbon pools for both plant and soils on the TP using machine learning algorithms. The estimated soil organic carbon (SOC) storage to 1 m depth was

32

.01

19

.69

47

.9

Pg (

11

.72

7

.2

17

.53

kg m−2 on average), accounting for approximately

37

.2

22

.9

55

.6

% of China’s SOC stock on its <30% land area. There was

15

.52

9

.91

23

.52

Pg C stored in grassland soils (1 m), which played as the largest C pool on the TP, followed by shrubland (

7

.52

4

.8

11.6

Pg) and forest (

3

.72

2

.5

5

.36

Pg). The estimated plant C pool was

2

.4

0

.95

5

.16

Pg (

1

.03

0

.2

2

.7

Pg in aboveground biomass (AGB) and

1

.37

0

.75

2

.45

Pg in belowground biomass). Soil and biomass C density presented a similar spatial pattern, which generally decreased from the east and southeast parts to the central and western parts. We found both vegetation and soil C (1 m depth) were primarily regulated by climatic variables and C input across the entire TP. However, main driving factors of the C stocks varied among vegetation types and depth intervals. Though AGB played as an important role in SOC variation for both topsoil (0–30 cm) and subsoil (30–100 cm), the strength of the correlation weakened with depth and was gradually attenuated from grassland to shrubland, and forest. The outcomes of this study provided an updated geospatial estimate of SOC stocks for the entire TP and their relationships with environmental factors, which are essential to carbon model benchmarking and better understanding the feedbacks of C stocks to global change.
Soliton resonance and web structure in the Davey–Stewartson system
Authors: Biondini Gino , Kireyev Dmitri , Maruno Ken-ichi
Published: June 2022

We write down and characterize a large class of nonsingular multi-soliton solutions of the defocusing Davey–Stewartson II equation. In particular we study their asymptotics at space infinities as well as their interaction patterns in the xy-plane, and we identify several subclasses of solutions. Many of these solutions describe phenomena of soliton resonance and web structure. We identify a subclass of solutions that is the analogue of the soliton solutions of the Kadomtsev–Petviashvili II equation. In addition to this subclass, however, we show that more general solutions exist, describing phenomena that have no counterpart in the Kadomtsev–Petviashvili equation, including V-shape solutions and soliton reconnection.
Facile synthesis of sulfur and oxygen co-doped graphitic carbon nitride quantum dots for on-off detection of Cu2+ in real samples and living cells
Authors: Zhang Mengting , Zhang Yulu , Gan Mingyu , Xie Liping , Wang Jing , Jia Weihua , Bian Wei , Shuang Shaomin , Choi Martin M F
Published: June 2022

A fluorescent sulfur and oxygen co-doped graphitic carbon nitride quantum dots (S,O-CNQDs) were prepared from ethylenediaminetetraacetic acid disodium salt dihydrate and thiourea as the carbon and sulfur sources. The morphology and surface functional groups of S,O-CNQDs were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The fluorescence of S,O-CNQDs could be quenched efficiently by Cu2+ under the optimum conditions. The S,O-CNQDs could function as an excellent fluorescent probe for Cu2+ detection with a wide linear range of 0.50–15 μM and a low detection limit of 0.58 nM. In addition, this fluorescent probe was employed for monitoring Cu2+ in samples of tap water, lake water, human serum and urine with good recoveries from 99.0% to 110.0%. Moreover, the S,O-CNQDs with high cell penetration and low cytotoxicity were utilized for Cu2+ detection in living cells. Owing to the excellent properties of S,O-CNQDs, the as-prepared S,O-CNQDs can be a potential candidate for biological applications.
Plasmon spectroscopy for the determination of Ti3C2T
x
MXene few layer stacks architecture
Authors: Bilyk T , Hsiao H-W , Yuan R , Benchakar M , Habrioux A , Célérier S , Zuo J-M , Pacaud J , Mauchamp V
Published: June 2022

Like many 2D materials, numerous properties of MXene multilayers, and especially the most popular one Ti3C2T
x
, have been shown to significantly depend on their architecture, i.e. the number of layers and interlayer distance. These structural parameters are thus key elements to be characterized for the analysis of MXene properties. Focusing on valence electron energy-loss spectroscopy (VEELS) as performed in a transmission electron microscope (TEM), and using density functional theory (DFT) simulations, we here analyze the layer dependent large changes in the VEEL spectra of Ti3C2T
x
multilayers as a probe of their total thickness, and emphasize the bulk plasmon energy sensitivity to interlayer distance. Together these findings allow to directly quantify the absolute number of layers in a Ti3C2T
x
stack up to ∼10 nm thickness and give access to interlayer distance modifications with sub-angström sensitivity, evidencing VEELS as a powerful method for the characterization of MXene multilayers on the nanometer scale. We expect these results to be relevant for the study of structure/properties correlations in this class of materials, especially with the development of in situ or environmental TEM experiments.
A recyclable solid catalyst of KF/Ca-Mg-Al-O using for biodiesel production from jatropha seed oil: preparation, characterization, and methanolysis process optimization
Authors: You Qinghong , Yin Xiulian , Wang Jun , Dai Chunhua
Published: June 2022

A recyclable heterogeneous KF/Ca-Mg-Al-O catalyst was prepared by co-precipitation and calcination processes. The characteristics of the catalyst were investigated using FTIR, XRD, TG-DTG and SEM. Response surface methodology was utilized to obtain the best most extreme biodiesel production yield. The ideal biodiesel production conditions were: the amount of catalyst was 3 wt%; the reaction temperature was 65 °C; the alcohol oil molar ratio 9.8:1, the reaction time was 3.5 h. Under these amended conditions, the average biodiesel yield was 95.19%, which is well in close concurrence with the worth anticipated by the model. The repeatability of catalysts was studied. After using the catalyst seven times, the catalytic efficiency was only reduced by 2.7%. These results indicate that the catalyst has good catalytic efficiency and is recyclable.
Optimization for preparing Bi1.68Pb0.32Sr1.75Ca1.85Cu2.85O10+y powders by wet ball milling
Authors: Chen Yingwei , Shao Ling , Zhao Guomeng , Liu Qijie , Huang Yingqi , Liu Zhenzhong , Zhu Liu , Wang Tianle , Zheng Beibei
Published: June 2022

Superconducting Bi1.68Pb0.32Sr1.75Ca1.85Cu2.85O10+y
(Bi-2223) powders were prepared by a conventional solid-state reaction using hand grinding and wet ball milling. The effects of the ball milling and sintering times on the phase evolution were examined by x-ray diffraction and magnetic susceptibility measurements. Single-phase Bi-2223 powders with a superconducting transition temperature of about 108 K were optimally prepared by wet ball milling for 20 h and sintering at 867 °C for 80 h. Finding these optimal preparation conditions were crucial for mass producing high-quality single-phase Bi-2223 precursor powders with a much lower cost of energy. Furthermore, we found that ball milling led to thinner grains than hand grinding.
Precise finite element verification of the unreliability of using multi-layers of FRP on CFRP-debonding in RC beams
Authors: Abdulrahman Bassam Qasim
Published: June 2022

The nonlinear behaviour of an adhesive material that connects layer of carbon fibre reinforced polymer (CFRP) to a reinforced concrete (RC) beam is numerically simulated in this study. To the author’s knowledge, how debonding increases significantly with increasing FRP thickness has not yet been studied theoretically only with few experimental studies that directly say this information. The work is conducted via a finite element approach using the commercially available software ABAQUS 6.13. Firstly, the 3D finite element model is introduced and all the suitable elements, material properties, damage initiation and evolution, and failure criteria are presented. Initially, the numerical model is validated by using the experimental study of a CFRP strengthened beam, which is chosen from literature. The model is shown to accurately capture slip at the interface of the strengthening material and resultant debonding. Furthermore, the tensile strain profile along the CFRP sheet is studied and, which has shown a reverse trend to the interfacial slip profile. Using the validated model, a detailed study is conducted with regards to the effects of multiple CFRP layers on the ultimate capacity and failure mode of the strengthened RC beam. It is found that adding two layers similar to the thickness of one layer will not change the response of the beam. However, this makes the beam behave with less ductility. Furthermore, the difference between the two cases is that the damage of one layer is concentrated at the FRP free end for a short distance. While, for two layers it is also at the free end but extended to a longer distance to the centre of the beam what causes earlier debonding. It is also found that adding one layer of CFRP to strengthen a RC beam can improve the ultimate capacity by 22%. But adding more CFRP layers does not increase the ultimate capacity or change the failure mode. In addition, it will reduce the total deflection of the beam. The study has also found that the interface bond-stresses are non-uniformly distributed along the reinforced boundaries and the shear stresses values exhibit peak values of 1 to 2 times greater than or 1 to 0.5 times less than the mean values predicted by the classical beam theory. Moreover, during the simulation, no de-lamination was observed between the superimposed CFRP plates for the two layers of CFRP.
Sums of proper divisors follow the Erdős–Kac law
Authors: Pollack Paul , Troupe Lee
Published: June 2022

Let

s
(
n
)
=

∑

d
∣
n
,
 
d
>
n

d

s(n)=\sum _{d\mid n,~d>n} d

denote the sum of the proper divisors of

n
n

. The second-named author proved that

ω
(
s
(
n
)
)

\omega (s(n))

has normal order

log
⁡
log
⁡

n

\log \log {n}

, the analogue for

s
s

-values of a classical result of Hardy and Ramanujan [The normal number of prime factors of a number n [Quart. J. Math. 48 (1917), 76–92], AMS Chelsea Publ., Providence, RI, 2000, pp. 262–275]. We establish the corresponding Erdős–Kac theorem:

ω
(
s
(
n
)
)

\omega (s(n))

is asymptotically normally distributed with mean and variance

log
⁡
log
⁡

n

\log \log {n}

. The same method applies with

s
(
n
)

s(n)

replaced by any of several other unconventional arithmetic functions, such as

β
(
n
)
≔

∑

p
∣
n

p

\beta (n)≔\sum _{p\mid n} p

,

n
−
φ
(
n
)

n-\varphi (n)

, and

n
+
τ
(
n
)

n+\tau (n)

(

τ
\tau

being the divisor function).
Global 𝑊^{2,𝑝} estimates for elliptic equations in the non-divergence form
Authors: Qiu Weifeng , Tang Lan
Published: June 2022

This paper is devoted to establishing global

W

2
,
p

W^{2, p}

estimate for strong solutions to the Dirichlet problem of uniformly elliptic equations in the non-divergence form where the domain is a Lipschitz polyhedra.
The mapping class group of connect sums of 𝑆²×𝑆¹
Authors: Brendle Tara , Broaddus Nathan , Putman Andrew
Published: June 2022

Let

M
n

M_n

be the connect sum of

n
n

copies of

S
2

×

S
1

S^2 \times S^1

. A classical theorem of Laudenbach says that the mapping class group

Mod
⁡
(

M
n

)

\operatorname {Mod}(M_n)

is an extension of

Out
⁡
(

F
n

)

\operatorname {Out}(F_n)

by a group

(

Z

/

2

)
n

(\mathbb {Z}/2)^n

generated by sphere twists. We prove that this extension splits, so

Mod
⁡
(

M
n

)

\operatorname {Mod}(M_n)

is the semidirect product of

Out
⁡
(

F
n

)

\operatorname {Out}(F_n)

by

(

Z

/

2

)
n

(\mathbb {Z}/2)^n

, which

Out
⁡
(

F
n

)

\operatorname {Out}(F_n)

acts on via the dual of the natural surjection

Out
⁡
(

F
n

)
→
G

L
n

(

Z

/

2
)

\operatorname {Out}(F_n) \rightarrow GL_n(\mathbb {Z}/2)

. Our splitting takes

Out
⁡
(

F
n

)

\operatorname {Out}(F_n)

to the subgroup of

Mod
⁡
(

M
n

)

\operatorname {Mod}(M_n)

consisting of mapping classes that fix the homotopy class of a trivialization of the tangent bundle of

M
n

M_n

. Our techniques also simplify various aspects of Laudenbach’s original proof, including the identification of the twist subgroup with

(

Z

/

2

)
n

(\mathbb {Z}/2)^n

.
1025 THE IMPACT OF DEPRIVATION AND FRAILTY ON THE LIKELIHOOD OF RECEIVING HIP AND KNEE ARTHROPLASTY DUE TO OSTEOARTHRITIS
Authors: Cook M J , Lunt M , Board T , O'Neill T W
Published: June 2022

Introduction

We determined the impact of deprivation and frailty at the time of diagnosis of hip or knee osteoarthritis (OA) on the likelihood of receiving total hip/knee arthroplasty (THA/TKA).

Method

We used routinely collected primary care data (Clinical Practice Research Datalink), linked to Hospital Episode Statistics. Frailty was assessed at the time of OA diagnosis using the electronic frailty index and categorised as fit, mild, moderate, and severe frailty. The association between quintile of index of multiple deprivation (IMD), frailty category and likelihood of receiving THA and TKA was assessed in separate Cox regression models, adjusted for year of OA diagnosis, age, and sex.

Results

104,672 individuals with hip OA and 220,714 with knee OA contributed data. Compared to those in the first quintile of IMD (least deprived), those in the fourth and fifth quintile of IMD (most deprived), respectively, were less likely to receive THA, hazard ratio (HR) (95% CI), 0.92 (0.89, 0.95) and 0.80 (0.77, 0.83), with similar results for TKA. Increasing frailty at OA diagnosis was associated with reduced likelihood of receiving THA/TKA. Compared to fit individuals, the HR (95% CI) for receiving THA and TKA, respectively among those with severe frailty was 0.42 (0.39, 0.45) and 0.57 (0.53, 0.61). Increasing deprivation was associated with increasing frailty at the time of hip/knee OA diagnosis, independent of age, sex, and year of OA diagnosis. However, those in the two most deprived quintiles were still less likely to receive THA/TKA after additionally adjusting for frailty category.

Conclusion

Increased deprivation and increased frailty category were associated with a lower likelihood of receiving THA/TKA among people with hip/knee OA. Increased frailty did not, however, explain the reduced likelihood of receiving THA/TKA among those living in the most deprived areas.
1030 EXPERIENCES OF EARLY SUPPORTED DISCHARGE SERVICES FOLLOWING A STROKE: A QUALITATIVE EVIDENCE SYNTHESIS
Authors: Connor E O , Dolan E , Horgan F , Robinson K , Galvin R
Published: June 2022

Background

Early supported discharge (ESD) facilitates people with a stroke to be discharged from the hospital environment earlier than conventional care to continue their rehabilitation within the home with a multi-disciplinary team. Known benefits of ESD from Randomised Controlled Trials conducted include reducing the length of a hospital stay, long term dependency, and cost savings. There is limited qualitative evidence available on ESD. This systematic review and qualitative synthesis explored the experiences of those involved in ESD including people with stroke, family members, caregivers as well as healthcare professionals.

Method

A literature search was completed in 11 databases which generated 3,425 articles. Qualitative or mixed

Method

studies that included qualitative data on the experiences of people with stroke, family members, caregivers and healthcare professionals of an ESD service were included. The Critical Appraisal Skills Programme checklist was used to appraise the methodological quality of the papers. The findings were synthesised using the three step process for thematic synthesis.

Results

A total of fourteen studies were included with the methodological quality of the studies deemed good overall. Four key themes emerged: 1) ESD is experienced by people with stroke as a goal-focused and supportive process leading to positive outcomes, 2) ESD eases the transition from the hospital to the home environment but the transition from ESD to social and community services is often problematic, 3) Organisational, logistical and inter-professional factors are critical to the success of ESD and 4) The home environment enhances rehabilitation.

Conclusion

The findings of this qualitative evidence synthesis highlight the importance of the home environment in the rehabilitation process post stroke. Key practice implications point to the need for increased attention to periods where care transitions occur from ESD to community services.
989 IS DIET QUALITY AS IMPORTANT AS DIET QUANTITY IN THE OLDER ADULT? MICRONUTRIENT DEFICIENCY, FRAILTY AND SARCOPENIA
Authors: Jennings C , Slee A , Weekes C E
Published: June 2022

Introduction

Dietary research in older adults has focused on energy content, macronutrient composition and diet quantity. Dietary antioxidants can theoretically ameliorate oxidative stress, which is widely implicated in age-related degeneration. Additional vital micronutrients are magnesium, being a co-factor for antioxidant enzyme function, and potassium, given its role in nerve and muscle function, and fluid balance. This study sought to investigate diet quality, specifically micronutrient content, and independent nutritional risk factors for frailty and sarcopenia.

Method

Secondary analysis of NUTRICOM 2015–2018 study participants (NIHR 19045)—exploring the impact of malnutrition on community-dwelling older adults—was conducted. Dietary intake was assessed using multiple-pass 24-hour dietary recall, nutrition risk status (NRS) using Guy’s and St Thomas’ NRS Tool, frailty using the 7-point Clinical Frailty Scale (CFS) and sarcopenia using EWGSOP2 handgrip strength cut-offs. Mann–Whitney U-Test assessed differences in dietary intake between malnutrition risk groups. Multivariable regression models, adjusting for age, gender, deprivation and comorbidities, established nutritional correlates of frailty and sarcopenia.

Results

142 participants; mean age 77.4(SD 8.4) years, 83(59%) female, mean BMI 26.05(SD 5.35). 79%–91% of older adults showed dietary deficiency in zinc, selenium, copper, magnesium and potassium. CFS increase was independently associated with NRS, and deficiency of potassium, copper and cumulative micronutrients, by 1.52, 1.19, 0.82 and 0.28 respectively (p < 0.05). Individuals with dietary zinc deficiency were 3.25 times more likely to have sarcopenia than individuals with sufficient zinc intake (95%CI: 1.04–10.16, p = 0.042).

Conclusion

Routine nutrition risk screening (accounting for macronutrient intake) finds only about 5% of older adults to be at-risk of malnutrition, whilst assessment of dietary intake in this study suggests dietary micronutrient deficiency is very common and is associated with increased frailty. 24-hour recall only provides a snapshot of dietary intake; further studies should be conducted using method that measure habitual dietary intake e.g. 7-day dietary diary.
1070 IMPACT OF ECONOMIC FACTORS, SOCIAL HEALTH AND RECENT STRESSORS ON PHYSICAL HEALTH-RELATED QUALITY OF LIFE TRAJECTORIES
Authors: Phyo A Z Z , Gonzalez-Chica D , Stocks N , Woods R , Fisher J , Tran T , Owen A , Ward S , Britt C , Ryan J ,   on behalf of the ASPREE Investigator Group (www.aspree.org), Freak-Poli R
Published: June 2022

Introduction

Poorer physical health-related quality of life (HRQoL) has been shown to predict a higher risk of adverse health outcomes including cognitive decline, cardiovascular disease, and mortality among community-dwelling older individuals. However, little is known about how physical HRQoL changes over time in older people and the predictors of this trajectory. This study (a) identified trajectories of physical HRQoL among older people and (b) explored whether economic factors, social health, or recent stressors impact physical HRQoL trajectories.

Method

A cohort of 12,506 community-dwelling Australians aged ≥70 years (54.4% females), enrolled in the ASPREE Longitudinal Study of Older Persons (ALSOP) study and was followed for six years. Physical HRQoL was assessed by using a validated instrument (SF-12; version-2) at baseline and over up to six annual follow-ups. Economic factors, social health, and recent stressors (i.e. stressful life events in the last 12 months) were assessed through a questionnaire at baseline. Growth mixture and structural equation modelling were used to identify physical HRQoL trajectories and their predictors.

Results

Four physical HRQoL trajectories were identified—stable low (7.1%), declining (9.0%), stable intermediate (17.9%) and stable high (66.0%). Living in more disadvantaged areas, having economic burden, no voluntary work, loneliness, or recent stressors (i.e. spousal illness, friend/family illness, financial problem, pet died) were associated with a 10%–152% higher likelihood of being in the stable low or declining physical HRQoL trajectory than the stable high group.

Conclusion

Specific stressors including financial hardship had a greater impact on adverse physical HRQoL trajectories in older people than other factors. This study highlights that grassroots approaches are needed to emphasize economic autonomy and social support networks in order to support the wellbeing of older people. Volunteering may prevent physical HRQoL decline and requires further investigation.
762 FOR OLDER PATIENTS WITH FRAILTY, SIX WEEKS OF ENFORCED IMMOBILITY HAS NO DETRIMENTAL IMPACT ON MUSCLE STRENGTH OR THICKNESS
Authors: Lunt E , Gordon A L , Greenhaff P , Gladman J R
Published: June 2022

Introduction

Immobility can lead to rapid reductions in muscle size, strength and function. Understanding these changes could inform interventions to prevent or slow decline. This longitudinal study aimed to assess the extent of muscle changes in older patients admitted with fragility fractures where clinical management was immobilisation (non-weight bearing) of the affected limb for at least 6 weeks.

Method

Handgrip strength (HGS); knee extensor strength(KES); Vastus Lateralis thickness and cross-sectional area at ultrasound (VLMT, VLCSA); and skeletal mass index (SMI; bioimpedance analysis) were measured in the non-injured limb of 50 patients (88% female) aged ≥70. Pre-existing physical frailty meant patients were limited to transfers only while non-weight bearing. Measurements were performed at hospital admission, 1, 3 and 6 weeks. One-way repeated measures ANOVA was used to assess changes in measurements over time. Additionally, baseline measurements in female patients (n = 36) were compared to 11 healthy, non-frail, non-hospitalised females with comparable BMI, aged ≥70, using independent t-tests. Data are mean + SD.

Results

Patient Clinical Frailty Score (median, IQR) was 5 (4–6). At hospital admission, female patients were older (84 ± 7 years vs. 77 ± 6 years, p < 0.05), weaker (HGS of 9.2 ± 4.7 kg vs. 19.9 ± 5.8 kg, p < 0.001; KES 4.5 ± 1.5 kg vs. 7.8 ± 1.3 kg, p < 0.001) and had lower VLMT (1.38 ± 0.47 cm vs. 1.75 ± 0.30 cm, p = 0.02) than non-frail female controls. Six weeks immobility had no temporal effect on any variable: HGS (F(2,51) = 1.04,p = 0.38,n = 27), KES (F(3,45) = 3.22,p = 0.81,n = 16), VLMT (F(3,54) = 2.52,p = 0.07,n = 19), VLCSA (F(3,42) = 0.74,p = 0.53,n = 15) and SMI (F(2,59) = 0.09,p = 0.94,n = 26).

Conclusion

Older patients admitted with fragility fractures were weaker and had lower VLMT compared to healthy, non-frail older people. This, together with the lack of decline in muscle strength and thickness with 6 weeks immobility strongly suggests muscle resilience was attenuated pre-admission, such that immobility had no further detrimental effect. These results differ from muscle changes seen in younger and non-frail cohorts, and warrants assessment of clinical interventions aimed at increasing muscle mass and function specifically in older people with frailty.
950 USE OF A ‘COVID BUNDLE’ TO IMPROVE PATIENT CARE DURING WAVE 2 IN A BUSY DGH
Authors: Quirie C , Olley R
Published: June 2022

The early stage of wave 2 in SJH was a very busy and rapidly evolving situation for the medical team. Dexamethasone and remdesivir had recently been introduced into clinical practice following RECOVERY trial results. High clinical demand, and a rapid turn-over of junior medical staff in the COVID wards meant unfamiliarity with the treatment. My COVID Bundle was designed as a support tool for medical staff in safely managing patients who tested positive for COVID-19 to: 1. Improve easy to see documentation of target oxygen saturations in patients with COVID-19 disease 2. Improve the monitoring of blood sugars when patients were started on dexamethasone for COVID-19 disease Thirty covid positive patients were included in the initial baseline data collection from the medical wards. Of these, only four (13.3%) had clear documentation of target oxygen saturations. Fifteen were commenced on dexamethasone, of which seven (46.7%) had appropriate monitoring of their blood sugars.

A series of interventions were then implemented. Initially I created a ‘COVID Bundle’ for patient’s bedside notes which prompted staff on 1) target oxygen saturations, 2) escalation status, 3) resuscitation status, 4) checking BMswhen on dexamethasone. I then updated and combined my COVID Bundle with a COVID treatment poster, which was placed in all ‘red’ patient notes.

I had several rounds of data collection during the series of interventions. The clear documentation of target oxygen saturations increased from 13.3% to 100%, while appropriate monitoring of BMsincreased from 46.7% to 93.3%. The management of COVID-19 is an ever evolving area, which can be difficult for both medical and nursing staff to keep up with in an ever busy working environment. This small scale QIP shows that the ‘COVID Bundle’ is a useful aid for staff in the safe management of patients with COVID-19.