bluuebunny/crossref_metadata_2025 huggingface dataset:
A new approach for modeling delayed fire‐induced tree mortality
Authors: Maringer Janet , Hacket‐Pain Andrew , Ascoli Davide , Garbarino Matteo , Conedera Marco
Published: May 2021

Global change is expanding the ecological niche of mixed‐severity fire regimes into ecosystems that have not usually been associated with wildfires, such as temperate forests and rainforests. In contrast to stand‐replacing fires, mixed‐severity fires may result in delayed tree mortality driven by secondary factors such as post‐fire environmental conditions. Because these effects vary as a function of time post‐fire, their study using commonly applied logistic regression models is challenging. Here, we propose overcoming this challenge through the application of time‐explicit survival models such as the Kaplan‐Meier (KM‐) estimator and the Cox proportional‐hazards (PH‐) model. We use data on tree mortality after mixed‐severity fires in beech forests to (1) illustrate temporal trends in the survival probabilities and the mortality hazard of beech, (2) estimate annual survival probabilities for different burn severities, and (3) consider driving factors with possible time‐dependent effects. Based on our results, we argue that the combination of KM‐estimator and Cox‐PH models have the potential of substantially improve the analysis of delayed post‐disturbance tree mortality by answering when and why tree mortality occurs. The results provide more specific information for implementing post‐fire management measures.
LaNixFe1‐xO3‐δ‐Quantum Dot/CNT Composite for High Performance Oxygen Evolution Reaction
Authors: Lu Shiqing , Wang Yangchen , Han Yuqi , Zhong Ming , Yang Haidong , Su Bitao , Lei Ziqiang
Published: May 2021

Rational design of active and earth‐abundant catalysts toward oxygen evolution reaction (OER) is of particular significance for archiving highly efficient water electrolysis. Herein, a series of perovskite oxide quantum dots with abundant oxygen vacancies adhered on oxidized carbon nanotubes (LaNiXFe1‐XO3‐δ‐QDs/CNTs) were fabricated by simple sol‐gel and pyrolysis methods. The results indicate that the optimized LaNi0.3Fe0.7O2.759‐QDs/CNTs sample with adjust crystal structure, proper ratio of Ni to Fe, and desirable oxygen vacancy concentration shows a low overpotential (0.34 V at 10 mA/cm2), a low Tafel slope (74 mV dec−1), and excellent stability when it was evaluated as OER electrocatalyst. This work will shed light on the development of precious‐metal‐free catalysts with promoted catalytic performance
Bis(alkyl) Sc and Y Complexes Supported by Tri‐ and Tetradentate Amidinate Ligands: Synthesis, Structure, and Catalytic Activity in α‐Olefin and Isoprene Polymerization
Authors: Rad'kova Natalia Yu. , Skvortsov Grigorii G. , Cherkasov Anton V. , Fukin Georgy K. , Kovylina Tatyana A. , Ob'edkov Anatoly M. , Trifonov Alexander A.
Published: May 2021

Bis(alkyl) complexes [(2,6‐Me2C6H3)NC(tBu)N(C6H4−2‐OMe)]M(CH2C6H4−2‐NMe2)2 (M=Sc (4), Y (5)), [(2‐OMe−C6H4N)2C(tBu)]Y(CH2SiMe3)2(THF)2 (6), supported by N,N,O‐tridentate (4, 5) and N,N,O,O‐tetradentate (6) amidinate ligands were synthesized by the alkane elimination approach reacting tris(alkyl) rare‐earth species M(R)3Xn (R=Me3SiCH2, X=THF, n=2; R=CH2C6H4−2‐NMe2, n=0) with one equivalent of amidine (2,6‐Me2C6H3)N=C(tBu)−NH(C6H4−2‐OMe) (1) or (2‐MeO−C6H4)N=C(tBu)−NH(C6H4−2‐OMe) (2). The reaction of amidine 2 with equimolar amount of Y(CH2C6H4−2‐NMe2)3 in toluene unexpectedly results in the addition of N,N‐dimethylaminobenzyl group to C=N bond of one amidinate fragment, ligand disproportionation and the formation of novel bis(amide)amidinate complex [(2‐OMe−C6H4N)2C(tBu)CH2C6H4−2‐NMe2]Y[(2‐OMe−C6H4N)2C(tBu)] (7). Complexes 4–6 were evaluated as catalysts for α‐olefins and isoprene polymerization.
Intermolecular Dehydrogenative C−H/Si−H Cross‐Coupling for the Synthesis of Arylbenzyl Bis(silanes)
Authors: You Lijun , Yuan Wei , He Chuan
Published: May 2021

An iridium‐catalyzed intermolecular dehydrogenative C−H/Si−H cross‐coupling reaction for the synthesis of arylbenzyl bis(silanes) is developed. This hydrosilyl group steered intermolecular C−H silylation process features high chemo‐ and regioselectivity, giving access to a wide range of multi‐functionalized organosilanes in good yields from readily available starting materials with atom economy, efficiency, and environmental benignity.
Is patriotism helpful to fight the crisis? The role of constructive patriotism, conventional patriotism, and glorification amid the COVID‐19 pandemic
Authors: Rupar Mirjana , Jamróz‐Dolińska Katarzyna , Kołeczek Maryna , Sekerdej Maciej
Published: May 2021

We examined the link between constructive patriotism, glorification, and conventional patriotism and COVID‐19‐related attitudes and behaviors at different stages of the pandemic in Poland. In Study 1 (N = 663), constructive patriotism was positively associated with support for internal measures (e.g., raising awareness about health practices). Glorification was negatively linked to support for such measures and positively connected to support for external measures (e.g., closing the borders). In Study 2 (N = 522), constructive patriots showed greater compliance with hygiene and social distance practices. In Study 3 (N = 633), the attribution of responsibility for fighting the crisis to the state and particularly to individuals underlined the link between constructive patriotism and compliance with health practices. Additionally, constructive patriotism was linked to support for international collaboration. Study 4 (N = 1051), conducted on a representative sample, further corroborated these findings. The results regarding conventional patriotism were not consistent across studies.
High‐status people are more individualistic and analytic‐thinking in the west and wheat‐farming areas, but not rice‐farming areas
Authors: Zhang Haotian , Talhelm Thomas , Yang Qian , Hu Chao S.
Published: May 2021

Previous studies have found that high‐status people are more individualistic and think more analytically than people of lower social status. We find new evidence that this is not always the case. We tested a large sample (N = 1,418) of people across China on analytic thought and the friend–stranger distinction. In China's more individualistic wheat‐farming regions, social status patterns replicated findings from the West: high‐status people thought more analytically and drew smaller distinctions between friends and strangers. But in more interdependent rice‐farming regions, high‐status people thought more holistically and drew a larger distinction between friends and strangers. This suggests that culture shapes social status differences in thought style and individualism. The data also showed that STEM majors thought more analytically than non‐STEM majors. STEM differences in thought style were larger among older students, which is consistent with the idea that STEM training encourages analytic thinking over time.
Capacity analysis of cooperative amplify and forward multiple‐input multiple‐output systems
Authors: Eltira Khadiga , Jibreel Nareeman , Younis Abdelhamid , Mesleh Raed
Published: May 2021

The capacity and mutual information of amplify and forward (AF) cooperative multiple‐input multiple‐output (MIMO) systems with direct link are studied and analyzed in this article. Specifically, the capacities of space modulation techniques (SMTs)‐AF and spatial multiplexing (SMX)‐AF cooperative systems are derived, and the conditions under which the capacity is accomplished are discussed and interpreted. The impact of varying system and channel parameters on the capacity is studied and discussed. As well, the impact of the presence or the absence of the direct link on the capacity performance is discussed. It is revealed that the capacity can be attained if the distribution of both direct and cooperative links follow complex Gaussian distribution. The capacity of SMTs‐AF systems is shown to be higher than that of SMX‐AF counterparts. As well, the capacity of SMTs‐AF is shown to be independent of the fading channel distribution as the channel is a source of spatial symbols in SMTs. Additionally, it is disclosed that the capacity performance is significantly enhanced in the presence of the direct link and adding more AF relays enhances the performance.
Assessing the combustibility of claddings: A comparative study of the modified cone calorimeter method and cylindrical furnace test
Authors: Nguyen Kate , Kim Nam Kyeun , Bhattacharyya Debes , Mouritz Adrian
Published: May 2021

A cone calorimeter, a standard device to measure the fire reaction properties of materials, is modified in this study to investigate its potential to replace the cylindrical furnace test method to assess the combustibility of cladding materials used in buildings. The modification allows cladding materials to be evaluated under conditions closer to their end‐use configuration than the current testing condition in the cylindrical furnace test. In addition, the modified cone calorimeter method provides more quantitative data on the fire reaction properties of the cladding materials compared to the passed/failed indicator in the cylindrical furnace test. Comparative studies between modified cone calorimeter and cylindrical furnace test results for four types of cladding with different combustibility properties are performed. The surface temperature, time‐to‐ignition, and flaming duration values measured for the claddings using the two test methods are similar, leading to the same classification based on AS 1530.1 standard. Other fire reaction properties of the claddings can be measured using the modified cone calorimeter method, which is not possible with the cylindrical furnace test, including mass loss rate, heat release rate, and smoke production, which are particularly dependent on the formation of a ceramic‐like carbonaceous layer of tested samples.
Connectivity within regions characterizes epilepsy duration and treatment outcome
Authors: Chen Xue , Wang Yanjiang , Kopetzky Sebastian J. , Butz‐Ostendorf Markus , Kaiser Marcus
Published: May 2021

Finding clear connectome biomarkers for temporal lobe epilepsy (TLE) patients, in particular at early disease stages, remains a challenge. Currently, the whole‐brain structural connectomes are analyzed based on coarse parcellations (up to 1,000 nodes). However, such global parcellation‐based connectomes may be unsuitable for detecting more localized changes in patients. Here, we use a high‐resolution network (~50,000‐nodes overall) to identify changes at the local level (within brain regions) and test its relation with duration and surgical outcome. Patients with TLE (n = 33) and age‐, sex‐matched healthy subjects (n = 36) underwent high‐resolution (~50,000 nodes) structural network construction based on deterministic tracking of diffusion tensor imaging. Nodes were allocated to 68 cortical regions according to the Desikan–Killany atlas. The connectivity within regions was then used to predict surgical outcome. MRI processing, network reconstruction, and visualization of network changes were integrated into the NICARA (https://nicara.eu). Lower clustering coefficient and higher edge density were found for local connectivity within regions in patients, but were absent for the global network between regions (68 cortical regions). Local connectivity changes, in terms of the number of changed regions and the magnitude of changes, increased with disease duration. Local connectivity yielded a better surgical outcome prediction (Mean value: 95.39% accuracy, 92.76% sensitivity, and 100% specificity) than global connectivity. Connectivity within regions, compared to structural connectivity between brain regions, can be a more efficient biomarker for epilepsy assessment and surgery outcome prediction of medically intractable TLE.
Effect of antioxidant, malondialdehyde, macro‐mineral, and trace element serum concentrations in Bangladeshi patients with schizophrenia: A case‐control study
Authors: Uddin S. M. Naim , Sultana Farhana , Uddin Md. Giash , Dewan Syed Masudur Rahman , Hossain Mohammed Kamrul , Islam Mohammad Safiqul
Published: May 2021

Background

Schizophrenia (SCZ) is an incurable neuropsychiatric disorder generally described by impaired social behavior and altered recognition of reality. For the first time, this study explored serum levels of antioxidants (vitamin A, E, and C), malondialdehyde (MDA), macro‐minerals (calcium, potassium, and sodium), and trace elements (zinc, iron, and selenium) in Bangladeshi patients with SCZ and thereby, discovering any pathophysiological correlation.

Methods

This case‐controlled study evaluated 63 patients with SCZ as cases and 63 healthy individuals as controls. Vitamin A and E levels were defined by RP‐HPLC. MDA and vitamin C levels were measured by using UV spectrophotometry, and macro and trace elements by atomic absorption spectroscopy.

Results

This study found significantly (P ≤ 0.05) elevated MDA levels and decreased levels of antioxidants—vitamin A, C, and E and significantly (P ≤ 0.05) diminished levels of macro and trace elements in cases in contrast to the controls. Serum levels of zinc (Zn), selenium (Se), iron (Fe), potassium (K), calcium (Ca), and sodium (Na) were determined to be 0.33 ± 0.008, 0.0252 ± 0.00060, 0.24 ± 0.01, 64.18 ± 2.72, 36.88 ± 2.56, and 2657.5 ± 53.32 mg/L, respectively, in cases, whereas 0.79 ± 0.03, 0.0650 ± 0.00355,0.78 ± 0.03, 168.01 ± 2.85, 86.43 ± 2.55, and 3200.8 ± 29.96 mg/L, respectively, were determined in controls. Pearson's correlation analysis revealed a negative correlation between Zn and Na, Zn and K, Zn and Ca, Zn and Fe, Zn and Se, Fe and Na, and Fe and Se in patients.

Conclusions

The findings connect that the pathogenesis of SCZ may have a correlation with altered levels of antioxidants, MDA, macro‐minerals, and trace elements.
Medical image denoising using optimal thresholding of wavelet coefficients with selection of the best decomposition level and mother wavelet
Authors: Benhassine Nasser Edinne , Boukaache Abdelnour , Boudjehem Djalil
Published: May 2021

Medical images have become omnipresent in diagnosis and therapy. However, they can be affected by various types of noise that reduce image quality and make the final diagnostic decision difficult. The main objective of this research is to effectively remove the noise while preserving the important image characteristics. This paper proposes a novel approach for image denoising based on discrete wavelet transform (DWT) with the selection of the best decomposition level and mother wavelet. Then, the thresholding function is carried out in the detail coefficients. Optimal thresholding is done using new optimization techniques such as the crow search algorithm and social spider optimization techniques. Finally, the inverse of DWT is applied to reconstruct the denoised image. The proposed method is evaluated using peak signal to noise ratio, mean square error, and the structural similarity index measure. The experimental results show the efficiency of the optimization‐based denoising method over standard methods. Interesting results are obtained with all kinds of noise, and improvements about 30 dB can be reached with the Rician noise.
The Puppeteer behind the scenes: Toward understanding ecosystem leadership mechanisms to grow IoT in South Africa
Authors: Goshalia Chetan , McDonogh Jennifer , Mhlanga Prins , Sewchurran Kosheek
Published: May 2021

The IoT digital revolution has opened opportunities to resolve complex, economic, environmental and social issues. Digitizing efforts involve participating in an ecosystem of innovators, providers, evolving customer needs and government policies. Companies entering this world report experiencing complexities with realizing value for stakeholders. This study presents a critical inquiry into the IoT world in South Africa. A grounded theory methodology is applied to provide an understanding of the important mechanisms at play affecting uptake of IoTs in the ecosystem. We use the insights to develop a model relevant for IoT players and urban planners to enhance benefit realization for the ecosystem as a whole. The study provides insight into a missing, “Puppeteering” role, that is required to organize ecosystem participants in their pursuit of value. A significant finding is that this role is best played by technology owners so that they can co‐create and generate jointly‐developed power to realize potential value for the entire ecosystem. The role needs to synergistically organize ecosystem participants to capture and distribute value to sustainably grow the ecosystem; and to engage in the development of required capabilities to sustain this. We argue that this “puppeteer effect” has potential to foster an inclusive, sustainable IoT strategy.
Alteration of fibrin hydrogel gelation and degradation kinetics through addition of azo dyes
Authors: Gandhi Jarel K , Heinrich Lauren , Knoff David S , Kim Minkyu , Marmorstein Alan D
Published: May 2021

Fibrin is a degradable biopolymer with an excellent clinical safety profile. Use of higher mechanical strength fibrin hydrogels is limited by the rapid rate of fibrin polymerization. We recently demonstrated the use of higher mechanical strength (fibrinogen concentrations >30 mg/ml) fibrin scaffolds for surgical implantation of cells. The rapid polymerization of fibrin at fibrinogen concentrations impaired our ability to scale production of these fibrin scaffolds. We serendipitously discovered that the azo dye Trypan blue (TB) slowed fibrin gelation kinetics allowing for more uniform mixing of fibrinogen and thrombin at high concentrations. A screen of closely related compounds identified similar activity for Evans blue (EB), an isomer of TB. Both TB and EB exhibited a concentration dependent increase in clot time, though EB had a larger effect. While gelation time was increased by TB or EB, overall polymerization time was unaffected. Scanning electron microscopy showed similar surface topography, but transmission electron microscopy showed a higher cross‐linking density for gels formed with TB or EB versus controls. Based on these data we conclude that addition of TB or EB during thrombin mediated fibrin polymerization slows the initial gelation time permitting generation of larger more uniform fibrin hydrogels with high‐mechanical strength.
Drug‐induced organ injury in coronavirus disease 2019 pharmacotherapy: Mechanisms and challenges in differential diagnosis and potential protective strategies
Authors: Ommati Mohammad Mehdi , Mobasheri Ali , Heidari Reza
Published: May 2021

The world is currently facing an unprecedented pandemic caused by a newly recognized and highly pathogenic coronavirus disease 2019 (COVID‐19; induced by SARS‐CoV‐2 virus), which is a severe and ongoing threat to global public health. Since COVID‐19 was officially declared a pandemic by the World Health Organization in March 2020, several drug regimens have rapidly undergone clinical trials for the management of COVID‐19. However, one of the major issues is drug‐induced organ injury, which is a prominent clinical challenge. Unfortunately, most drugs used against COVID‐19 are associated with adverse effects in different organs, such as the kidney, heart, and liver. These side effects are dangerous and, in some cases, they can be lethal. More importantly, organ injury is also a clinical manifestation of COVID‐19 infection. These adverse reactions are increasingly recognized as outcomes of COVID‐19 infection. Therefore, the differential diagnosis of drug‐induced adverse effects from COVID‐19‐induced organ injury is a clinical complication. This review highlights the importance of drug‐induced organ injury, its known mechanisms, and the potential therapeutic strategies in COVID‐19 pharmacotherapy. We review the potential strategies for the differential diagnosis of drug‐induced organ injury. This information can facilitate the development of therapeutic strategies, not only against COVID‐19 but also for future outbreaks of other emerging infectious diseases.
Using a machine learning model for the optimal design of simulated moving bed processes and its application to separate rebaudioside A and stevioside
Authors: Yao Chuanyi , Zheng Zhenwei , Chen Kuan , Wei Liangwan , Shen Liang , Lu Yinghua , Fan Enguo
Published: May 2021

BACKGROUND

Solving a mechanistic model of simulated moving bed (SMB) is extremely time consuming, therefore, it is inefficient for online control using the optimization method based on such a mechanistic model. To this end, the machine learning model can be regarded as a potential substitution to accelerate the optimization process.

RESULTS

Several machine learning algorithms were applied to predict the product purities under various operation conditions using two SMB processes as case studies: i.e., a sugar separation of rebaudioside A and stevioside, as well as an enantioseparation of 1,1′‐bi‐2‐naphthol racemate. The results indicate that the random forest (RF) model and the deep neural network (DNN) model provide a satisfactory accuracy with a mean absolute error (MAE) lower than 0.19% (RF) and 0.08% (DNN), respectively. During the optimization process to maximize the feed flowrate under specific purity requirements, among the two selected models, DNN model showed a better generalization ability than RF model and gave a feed flowrate 10% higher than the highest value in the training dataset, which was consistent with the result obtained by using the mechanistic model. The optimized operation conditions for sugar separation were verified experimentally and the achieved purities of rebaudioside A and stevioside were 99.2% and 98.8%, respectively.

CONCLUSION

The DNN model was successfully used to substitute the mechanistic model to reach a rapid optimization of SMB processes with an improved efficiency of 103 ~ 104 times. © 2021 Society of Chemical Industry (SCI).
HIV risk and pre‐exposure prophylaxis interest among women seeking post‐abortion care in Kenya: a cross‐sectional study
Authors: Heffron Renee , Casmir Edinah , Aswani Linda , Ngure Kenneth , Kwach Benn , Ogello Vallery , Kiptinness Catherine , Ambiyo Faith , Wairimu Njeri , Ossome Ethel , Machafu Hilda , Zia Yasaman , Thomas Dorothy , Scoville Caitlin , Barker Taryn , Bukusi Elizabeth , Mugo Nelly
Published: May 2021

Introduction

Post‐abortion clinics located in regions with high HIV burden may ideal locations to integrate counselling and delivery of HIV pre‐exposure prophylaxis (PrEP), aligning with normative goals for integrated delivery of HIV and reproductive health care. The objective of this study was to gauge the degree to which Kenyan women seeking care for a pregnancy loss, including induced abortion, are at risk for HIV and whether women would welcome an introduction to PrEP prior to discharge from post‐abortion care.

Methods

We conducted a mixed‐methods study from August 2019 to February 2020 with women ages 15 to 30 recruited sequentially as they were accessing post‐abortion care at public and private facilities in Thika and Kisumu, Kenya. Data collection was through a cross‐sectional survey and laboratory testing for common sexually transmitted infections (N = 200), and in‐depth interviews (N = 30). Descriptive statistics summarize PrEP knowledge and referrals and a multivariable log‐link binomial model estimated correlates of receiving a referral for PrEP. Qualitative data were analysed using inductive and deductive approaches.

Results

Among 200 HIV‐negative women (median age 21.0, interquartile range 19.0 to 22.0), the prevalence of Chlamydia trachomatis was 18.2% and Neisseria gonorrhoeae was 2.0%. Half of the women scored ≥5 on a validated tool that would correspond to an expected HIV incidence of 9.5% per year. Approximately half (55.8%) of women were familiar with PrEP prior to the study and 33.3% received a referral from study staff to a clinic offering PrEP. In qualitative interviews, women expressed interest in accessing PrEP from the gynaecology ward that provided post‐abortion care but they preferred alternative locations for PrEP refills.

Conclusions

Kenyan women accessing post‐abortion care have substantial HIV risk and were favourable about the idea of receiving support to initiate PrEP as part of care offered during post‐abortion care. These settings can be integrated into national PrEP programmes as locations providing PrEP referrals and initiation.
Adherence to event‐driven HIV PrEP among men who have sex with men in Amsterdam, the Netherlands: analysis based on online diary data, 3‐monthly questionnaires and intracellular TFV‐DP
Authors: Jongen Vita W , Hoornenborg Elske , van den Elshout Mark AM , Boyd Anders , Zimmermann Hanne ML , Coyer Liza , Davidovich Udi , Anderson Peter L , de Vries Henry JC , Prins M , Schim van der Loeff Maarten F ,   the Amsterdam PrEP Project team in the HIV Transmission Elimination Amsterdam (H‐TEAM) Initiative
Published: May 2021

Introduction

Event‐driven pre‐exposure prophylaxis (edPrEP) with oral tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) is highly effective for preventing HIV acquisition in men who have sex with men (MSM) and is preferred over daily PrEP by some MSM. However, it is largely unknown how well MSM adhere to edPrEP. We then aimed to assess PrEP protection during CAS among MSM using edPrEP and participating in the Amsterdam PrEP demonstration project (AMPrEP).

Methods

We analysed data from participants enrolled in AMPrEP who were taking edPrEP. We measured adherence through (1) a mobile application in which sexual behaviour and PrEP‐use were recorded daily, (2) three‐monthly self‐completed questionnaires and (3) dried blood spot (DBS) samples collected around six, twelve and twenty‐four months after PrEP initiation. We assessed the proportion of days with condomless anal sex (CAS) acts that were protected by PrEP, per partner type (i.e. steady partners, known casual partners, unknown casual partners), and the proportion of three‐month periods during which PrEP was correctly used. Intracellular TFV‐diphosphate (TFV‐DP) concentrations were determined from DBS. Good adherence was defined as at least one tablet before and one tablet within 48 hours after a CAS act.

Results

Between 11 September 2015 and 6 October 2019, 182 of 376 MSM (48.4%) used edPrEP for at least one three‐month period. Of the 8224 CAS days that were reported in the app during edPrEP‐use, we observed good protection for most CAS days involving steady partners (n = 1625/2455, 66.9%), known casual partners (n = 3216/3472, 92.6%) and unknown casual partners (n = 2074/2297, 90.3%). Men reported consistently correct PrEP‐use in 851 (81.4%) of the 1046 three‐month periods of edPrEP‐use. The median TFV‐DP concentration was 591 fmol/sample (interquartile range = 270 to 896).

Conclusions

Adherence to edPrEP was high as determined from the online app and questionnaire. DBS measurements were consistent with two to three tablets per week on average.
Gadolinium Clearance in the First 5 Weeks After Repeated Intravenous Administration of Gadoteridol, Gadoterate Meglumine, and Gadobutrol to rats
Authors: Bussi Simona , Coppo Alessandra , Bonafè Roberta , Rossi Silvia , Colombo Serra Sonia , Penard Laure , Kirchin Miles A. , Maisano Federico , Tedoldi Fabio
Published: May 2021

Background

Studies of gadolinium (Gd) clearance from animals in the first weeks after administration of gadolinium‐based contrast agents (GBCAs) have previously looked at solitary timepoints only. However, this does not give information on differences between GBCAs and between organs in terms of Gd elimination kinetics.

Purpose

To compare Gd levels in rat cerebellum, cerebrum, skin, and blood at 1, 2, 3, and 5 weeks after repeated administration of macrocyclic GBCAs.

Study Type

Prospective.

Animal Model

One hundred eighty male Sprague–Dawley rats randomized to three groups (n = 60/group), received intravenous administrations of gadoteridol, gadoterate meglumine, or gadobutrol (0.6 mmol/kg for each) four times/week for 5 consecutive weeks. Rats were sacrificed after washout periods of 1, 2, 3, or 5 weeks.

Field Strength/Sequence

Not applicable.

Assessment

Cerebellum, cerebrum, skin, and blood were harvested for Gd determination by inductively coupled plasma‐mass spectrometry (15 animals/group/all timepoints).

Statistical Tests

Anova and Dunnett's test (data with homogeneous variances and normal distribution). Kruskal–Wallis and Wilcoxon's rank sum tests (data showing nonhomogeneous variances or a non‐normal distribution, significance levels: P < 0.05, P < 0.01, and P < 0.001).

Results

Gd levels in cerebellum, cerebrum, and skin were significantly lower after gadoteridol than after gadoterate and gadobutrol at all timepoints. Mean cerebellum Gd concentrations after gadoteridol, gadoterate, and gadobutrol decreased from 0.693, 0.878, and 1.011 nmol Gd/g at 1 week to 0.144, 0.282, and 0.297 nmol Gd/g at 5 weeks after injection. Similar findings were noted for cerebrum and skin. Conversely, significantly higher Gd levels were noted in blood after gadoteridol compared to gadobutrol at 1, 2, and 3 weeks and compared to gadoterate at all timepoints.

Data Conclusion

Gadoteridol is eliminated more rapidly from rat cerebellum, cerebrum, and skin compared to gadoterate and gadobutrol in the first 5 weeks after administration, resulting in lower levels of retained Gd in these tissues.

Evidence Level

1

Technical Efficacy

Stage 5
Neural network model with positional deviation correction for Fourier ptychography
Authors: Zhao Ming , Zhang Xiaohui , Tian Zhiming , Liu Shuai
Published: May 2021

Fourier ptychography is a new type of computational imaging technology, which uses a stack of low‐resolution images obtained from overlapped apertures (or equivalent) to reconstruct super‐resolved image. However, the accuracy of the aperture position will directly affect the quality and resolution of the reconstructed image. This paper proposes a new perspective for FP positional deviations correction using the neural network. We construct a trainable neural network to perform positional deviations correction along with object reconstruction. The real part and imaginary part of the object as well as the different and irregular positional deviations of each aperture are set as the weights of convolutional layer. The gradients over these weights are computed automatically, and gradient‐based optimization algorithm is employed to recover the object and find the correct aperture position. Simulation and experiment are performed to verify our algorithm. The results show that the proposed algorithm can accurately find the aperture position and improve the reconstruction quality.
A Comparison of an Artificial Intelligence Tool to Fundamental Frequency as an Outcome Measure in People Seeking a More Feminine Voice
Authors: Bensoussan Yael , Park Christopher , Johns Michael , Brown Sarah , Pinto Jeremy , Chang Joseph , Courey Mark
Published: May 2021

Objectives/Hypothesis

An artificial intelligence (AI) tool was developed using audio clips of cis‐male and cis‐female voices based on spectral analysis to assess %probability of a voice being perceived as female (%Prob♀). This program was validated with 92% accuracy in cisgender speakers. The aim of the study was to assess the relationship of fo on %Prob♀ by a validated AI tool in a cohort of trans females who underwent intervention to feminize their voice with behavioral modification and/or surgery.

Study Design

Cohort study.

Methods

Fundamental frequency (fo) from prolonged vowel sounds (fo/a/) and fo from spontaneous speech (fo‐sp) were measured using the Kay Pentax Computerized Speech Lab (Montvale, NJ) in trans females postintervention. The same voice samples were analyzed by the AI tool for %Prob♀. Chi‐square analysis and regression models were performed accepting >50% Prob♀ as female voice.

Results

Forty‐two patients were available for analysis after intervention. fo‐sp post‐treatment was positively correlated with %Prob♀ (R = 0.645 [P < .001]). Chi‐square analysis showed a significant association between AI %Prob♀ >50% for the speech samples and fo‐sp >160 Hz (P < .01). Sixteen of 42 patients reached an fo‐sp >160 Hz. Of these, the AI program only perceived nine patients as female (>50 %Prob♀).

Conclusion

Patients with fo‐sp >160 Hz after feminization treatments are not necessarily perceived as having a high probability of being female by a validated AI tool. AI may represent a useful outcome measurement tool for patients undergoing gender affirming voice care.

Level of Evidence

3 Laryngoscope, 131:2567–2571, 2021
CRISPR/Cas9 gene editing in legume crops: Opportunities and challenges
Authors: Bhowmik Pankaj , Konkin David , Polowick Patricia , Hodgins Connor Lorne , Subedi Maya , Xiang Daoquan , Yu Bianyun , Patterson Nii , Rajagopalan Nandhakishore , Babic Vivijan , Ro Dae‐Kyun , Tar'an Bunyamin , Bandara Manjula , Smyth Stuart J. , Cui Yuhai , Kagale Sateesh
Published: May 2021

Legumes are an excellent source of proteins and health‐promoting phytochemicals. Recognizing their importance in human nutrition and sustainable agricultural production, significant efforts are currently being made to accelerate genetic gain related to yield, stress resilience, and nutritional quality. Recent increases in genomic resources for multiple legume crops have laid a solid foundation for application of transformative breeding technologies such as genomic selection and genome editing for crop improvement. In this review, we focus on the recent plant‐specific advances in CRISPR/Cas9‐based gene editing technology and discuss the challenges and opportunities to harnessing this innovative technology for targeted improvement of traits in legume crops. Gene‐editing methods have been successfully established for soybean, cowpea, chickpea, and model legumes such as Medicago truncatula and Lotus japonicus. However, the recalcitrance of other legumes to in vitro gene transfer and regeneration has posed a serious challenge to application of gene editing. We discuss various modifications to in vitro culture methods, in terms of the choice of explant, media composition, and DNA delivery and gene‐editing detection methods that can potentially improve the rate of transformation and regeneration of whole plant in legume crops. Although gene‐editing technology can bring enormous benefits to legume breeding, regulatory hurdles are a cause for serious concern. We compare the regulatory environments existing in the European Union and the United States of America. A favorable regulatory framework and public acceptance are important factors in realizing CRISPR's potential benefits to global food security.
Multiculturalism: A Challenge for Cognitive Screeners in Parkinson's Disease
Authors: Statucka Marta , Cherian Kirsten , Fasano Alfonso , Munhoz Renato P. , Cohn Melanie
Published: May 2021

Background

The Montreal Cognitive Assessment (MoCA) and the Dementia Rating Scale‐2 (DRS‐2) are recommended screeners for Parkinson's disease mild cognitive impairment (PD‐MCI). Cross‐cultural studies examining their diagnostic precision have not addressed cultural bias in a multicultural setting.

Objectives

To compare DRS‐2 and MoCA performance between patients born in Canada, the USA, and the UK (Anglosphere group) and immigrant patients born elsewhere (International group). To identify sources of cultural bias by comparing group characteristics, and by assessing the relationships between performance and immigration and socio‐development variables. To examine the diagnostic precision of both tools in detecting PD‐MCI in each group.

Methods

We conducted a clinical chart review of advanced PD patients who completed cognitive screeners (MoCA: n = 288, 30% International group; DRS‐2: n = 426, 31% International group). All completed a comprehensive neuropsychological assessment to apply Level II PD‐MCI diagnostic criteria.

Results

The International group performed worse than the Anglosphere group on the MoCA and DRS‐2, and the only variable that accounted for some of the group difference was the Historical Index of Human Development, a societal variable, which fully mediated the group effect on the DRS‐2. Diagnostic precision of the MoCA was at chance level in the International group, and was poorer than that of the DRS‐II in this group and that of the MoCA in the Anglosphere group, although these were considered poor.

Conclusions

Our results support the recommendation to exert caution in using cognitive screeners to capture PD‐MCI in all patients and particularly with first generation immigrants.
Strategic stocking for new products to signal quality information
Authors: Jiang Yuan , Guan Xu , Tang Yao , Chen Simiao
Published: May 2021

This paper investigates the signaling role of stocking for new experience products in a two‐period setting. The seller privately observes the product quality information, which cannot be resolved until the second selling period. We show that the stocking plays a pivotal role in signaling the quality information, and the equilibrium strategy depends highly on ordering cost and the consumer prior belief about the seller type. If the seller is unable to dynamically decide the retail prices, separating equilibrium arises more frequently and such a fixed pricing may result in a win‐win situation for both seller and consumers.
Trans‐Ethnic Fine‐Mapping of the Major Histocompatibility Complex Region Linked to Parkinson's Disease
Authors: Naito Tatsuhiko , Satake Wataru , Ogawa Kotaro , Suzuki Ken , Hirata Jun , Foo Jia Nee , Tan Eng‐King , Toda Tatsushi , Okada Yukinori
Published: May 2021

Background

Despite evidence for the role of human leukocyte antigen (HLA) in the genetic predisposition to Parkinson's disease (PD), the complex haplotype structure and highly polymorphic feature of the major histocompatibility complex (MHC) region has hampered a unified insight on the genetic risk of PD. In addition, a majority of the reports focused on Europeans, lacking evidence on other populations.

Objectives

The aim of this study is to elucidate the genetic features of the MHC region associated with PD risk in trans‐ethnic cohorts.

Methods

We conducted trans‐ethnic fine‐mapping of the MHC region for European populations (14,650 cases and 1,288,625 controls) and East Asian populations (7712 cases and 27,372 controls). We adopted a hybrid fine‐mapping approach including both HLA genotype imputation of genome‐wide association study (GWAS) data and direct imputation of HLA variant risk from the GWAS summary statistics.

Results

Through trans‐ethnic MHC fine‐mapping, we identified the strongest associations at amino acid position 13 of HLA‐DRβ1 (P = 6.0 × 10−15), which explains the majority of the risk in HLA‐DRB1. In silico prediction revealed that HLA‐DRB1 alleles with histidine at amino acid position 13 (His13) had significantly weaker binding affinity to an α‐synuclein epitope than other alleles (P = 9.6 × 10−4). Stepwise conditional analysis suggested additional independent associations at Ala69 in HLA‐B (P = 1.0 × 10−7). A subanalysis in Europeans suggested additional independent associations at non‐HLA genes in the class III MHC region (EHMT2; P = 2.5 × 10−7).

Conclusions

Our study highlights the shared and distinct genetic features of the MHC region in patients with PD across ethnicities. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
Global strong solution of 2D Navier–Stokes–Korteweg system
Authors: Yu Yanghai , Wu Xing
Published: May 2021

In this paper, we consider the Cauchy problem to the two‐dimensional Navier–Stokes–Korteweg system with nonvacuum and general pressure laws and establish the global well‐posedness of strong solution for general initial data in the framework of Sobolev spaces.
A model selection framework to quantify microvascular liver function in gadoxetate‐enhanced MRI: Application to healthy liver, diseased tissue, and hepatocellular carcinoma
Authors: Berks Michael , Little Ross A. , Watson Yvonne , Cheung Sue , Datta Anubhav , O’Connor James P. B. , Scaramuzza Davide , Parker Geoff J. M.
Published: May 2021

Purpose

We introduce a novel, generalized tracer kinetic model selection framework to quantify microvascular characteristics of liver and tumor tissue in gadoxetate‐enhanced dynamic contrast‐enhanced MRI (DCE‐MRI).

Methods

Our framework includes a hierarchy of nested models, from which physiological parameters are derived in 2 regimes, corresponding to the active transport and free diffusion of gadoxetate. We use simulations to show the sensitivity of model selection and parameter estimation to temporal resolution, time‐series duration, and noise. We apply the framework in 8 healthy volunteers (time‐series duration up to 24 minutes) and 10 patients with hepatocellular carcinoma (6 minutes).

Results

The active transport regime is preferred in 98.6% of voxels in volunteers, 82.1% of patients’ non‐tumorous liver, and 32.2% of tumor voxels. Interpatient variations correspond to known co‐morbidities. Simulations suggest both datasets have sufficient temporal resolution and signal‐to‐noise ratio, while patient data would be improved by using a time‐series duration of at least 12 minutes.

Conclusions

In patient data, gadoxetate exhibits different kinetics: (a) between liver and tumor regions and (b) within regions due to liver disease and/or tumor heterogeneity. Our generalized framework selects a physiological interpretation at each voxel, without preselecting a model for each region or duplicating time‐consuming optimizations for models with identical functional forms.
Two‐dimensional oxide based pressure sensors with high sensitivity
Authors: Liu Hao , Feng Bo , Bai Xiaosong , Qi Tianhang , Wei Zhiyong , Liu Ruichao , Yin Keke , Gao Jinxing , Yang Daoyuan , Zheng Guangchao , ten Elshof Johan E. , Shan Chongxin , Sun Qi‐Jun , Yuan Huiyu
Published: May 2021

Nanomaterials based pressure sensors have obtained world‐wide research interest due to their promising potential applications in health monitoring, artificial intelligence, and electronic skin (e‐skin). Despite the recent progress in sensitivity and detection range of the pressure sensors, the relatively high thickness of the active films has obstructed their applications for e‐skin and degraded the comfortability as wearable devices. We hereby report for the first time a novel pressure sensor based on two‐dimensional metal oxide nanosheets where the gaps between neighboring nanosheets are adjustable. The pressure sensors show a sensitivity of up to 7.2 × 106 kPa–1, which is the highest value ever reported for a pressure sensor. Additionally, the sensor shows good repeatability and excellent stability. The pressure‐sensing ranges can be tuned by adjusting the coverage of the nanosheet film. This work presents an effective strategy to develop ultrathin pressure sensors.
Does traditional pharmacotherapy augment behavioral modification in the treatment of nocturia?
Authors: Miller Connelly D. , Monaghan Thomas F. , Robins Dennis J. , Weiss Jeffrey P.
Published: May 2021

Aims

To assess the efficacy of traditional first‐line non‐antidiuretic pharmacotherapy for nocturia in the real‐world outpatient urology setting.

Methods

We retrospectively analyzed voiding diaries from adult men treated for lower urinary tract symptoms (LUTS) at an outpatient urology clinic to identify pairs of voiding diaries with ≥1 nocturnal void at baseline and a corresponding follow‐up diary completed within 1 year. We compared the odds of nocturia improvement (decrease of ≥1 nocturnal void) in patients started on LUTS pharmacotherapy versus behavioral modification alone.

Results

Two hundred and thirteen diary pairs from 93 patients were included. Fifty‐seven diary pairs were identified from patients prescribed at least one LUTS drug on the initial visit and 156 diary pairs were identified from patients receiving behavioral modification alone. All standard voiding diary parameters were assessed, and only maximum voided volume differed at baseline (240 ml [interquartile range: 200–330 ml] vs. 280 ml [200–400 ml] with and without pharmacotherapy, respectively, p = 0.04). The odds of nocturia improvement did not significantly differ between pharmacotherapy and behavioral modification treatment groups (crude odds ratio [OR]: 1.16 [95% confidence interval: 0.63–2.16], p = 0.63; maximum voided volume [MVV]‐adjusted OR: 1.19 [0.63–2.22], p = 0.59). In contrast, improvement in 24‐h urinary frequency was more likely with pharmacotherapy versus behavioral modification alone (crude OR: 2.36 [1.22–4.56], p = 0.01; MVV‐adjusted OR: 2.05 [1.05–4.01], p = 0.04). Results were consistent on subgroup analyses restricted to first diary pairs from each patient.

Conclusion

Despite improvement in 24‐h voiding frequency, there was no evidence that adjunctive pharmacotherapy provided a benefit in the treatment of nocturia in men receiving behavioral counseling.
Topology optimization of degradable composite structures with time‐changeable stiffness
Authors: Zhang Heng , Takezawa Akihiro , Ding Xiaohong , Xu Shipeng , Li Hao , Guo Honghu
Published: May 2021

For effective bone healing, the stiffness of the bone plate should be adjusted to different bone‐healing processes. Thus, the design of stiffness‐changeable structures that take into account the time effect is of importance. To this end, this study introduces a novel topological optimization approach for the composite structural layout design considering material degradation to realize structures with changeable stiffness over time. In this approach, two sets of variables are used: a density field that defines the material layout, and a time field that determines the effect of material degradation on mechanical performance. The continuous degradation update formula is proposed by integrating the Heaviside projected function and Kreisselmeier–Steinhauser function to guarantee its derivability. The objective is to minimize the summed compliance in some specified time steps subject to the constraints of volume fraction. The sensitivity of the aforementioned objective with respect to the design variable is deduced by considering the material degradation over time. The proposed design formulation is general and is demonstrated with several design analyses, considering different fix and degradable interface boundary conditions. Moreover, the results are compared with the results of not considering material degradation and demonstrate the effectiveness of the proposed method.
Validity and reliability of the RAC adult infection risk scale: A new instrument to measure healthcare‐associated infection risk
Authors: Rodríguez‐Acelas Alba Luz , de Abreu Almeida Miriam , Schmarczek Figueiredo Manoela , Monteiro Mantovani Vanessa , Mattiello Rita , Cañon‐Montañez Wilson
Published: May 2021

Healthcare‐associated infections represent a public health problem, and they have repercussions for patient safety. The aim of this study was to determine the psychometric properties of the Rodríguez–Almeida–Cañon (RAC) adult infection risk scale, focusing on the construct and predictive validity and reliability. The study enrolled 278 patients at a large hospital in southern Brazil. The research process involved the following three phases: construct validation, assessing predictive validity, and assessing reliability. Confirmatory factor analysis showed a good fit using a two‐factor model with 15 items. The logistic regression analysis showed an association between the scale score and prediction of developing healthcare‐associated infections (odds ratio: 1.18; 95% confidence interval: 1.08–1.28). The Cronbach's alpha was 0.72 for intrinsic factors subscale and 0.71 for extrinsic factors subscale. A high level of inter‐rater agreement (intraclass correlation coefficient ≥0.97) was found for both subscales. The Bland and Altman method showed narrow agreement limits, demonstrating good agreement between evaluators. The findings of this study showed that the RAC adult infection risk scale is a new, reliable, and psychometrically valid instrument to assess healthcare‐associated infections risk. Future research using this scale may lead to a better understanding of the healthcare‐associated infections risk and assist health professionals in decision‐making for interventions to improve patient safety.