bluuebunny/crossref_metadata_2025 huggingface dataset:
Há diferença na força de compressão interfragmentar entre parafusos com rosca total ou parcial? Resultados de um estudo biomecânico experimental piloto
Authors: Okoro Tosan , Landgren Marcus , Afenu Edem , Russow Gabriele , Wulsten Dag , Heyland Mark
Published: July 2022

Objetivo Este estudo avaliou diferenças entre parafusos com rosca total ou parcial na resistência à compressão interfragmentar inicial. Nossa hipótese era de que haveria maior perda de resistência à compressão inicial com o parafuso de rosca parcial.

Métodos Uma linha de fratura oblíqua de 45 graus foi criada em amostras de osso artificial. O primeiro grupo (TOTAL, n = 6) foi fixado com um parafuso de 3,5 mm de rosca total, enquanto o segundo grupo (PARCIAL, n = 6) usou um parafuso de 3,5 mm de rosca parcial. Avaliamos a rigidez à torção em ambas as direções de rotação. Os grupos foram comparados com base nos seguintes parâmetros biomecânicos: momento de rigidez-ângulo, momento de rigidez-tempo, momento de torção máxima (carga de falha) e força de compressão calibrada com base na medida do sensor de pressão.

Resultados Depois da perda de uma amostra PARCIAL, não foram observadas diferenças estatisticamente significativas na força de compressão calibrada entre os 2 grupos [mediana (intervalo interquartil)]: TOTAL: 112,6 (10,5) N e PARCIAL: 106,9 (7,1) N, com p = 0,8 segundo o teste U de Mann-Whitney). Além disso, após a exclusão de 3 amostras para testes mecânicos (TOTAL, n = 5, PARCIAL, n = 4), não foram observadas diferenças estatisticamente significativas entre os construtos TOTAL e PARCIAL quanto ao momento de rigidez-ângulo, momento de rigidez-tempo ou momento de torção máxima (carga de falha).

Conclusão Não há diferença aparente na força de compressão inicial (força de compressão ou rigidez do construto ou carga de falha) com o uso de parafusos de rosca total ou parcial neste modelo biomecânico em osso artificial de alta densidade. Parafusos de rosca total podem, portanto, ser mais úteis no tratamento de fraturas diafisárias. Mais pesquisas são necessárias sobre o impacto em modelos ósseos osteoporóticos ou metafisários de menor densidade e avaliação do significado clínico.
Técnica de reconstrução do pé com prótese de calcâneo feita sob medida em câncer primário – Relato de caso
Authors: Gowda Aditya K. S. , Dhingra Mohit , Vathulya Madhubari , Seenivasagam Rajkumar K.
Published: July 2022

O pé é um local incomum para tumores ósseos, e compreende cerca de 3% de todos os tumores esqueléticos, em especial ao redor do calcâneo. A cirurgia radical cria um vazio no pé, o que afeta de forma negativa a capacidade de resgate do membro. As cirurgias de reconstrução do calcâneo não são comumente realizadas por causa da instabilidade da prótese, defeito de partes moles, e consequente possibilidade de insucesso pós-operatório. Assim, apresentamos aqui um caso raro de sarcoma sinovial originário da bainha do tendão tibial posterior com acometimento secundário do osso calcâneo. Considerando as experiências prévias de diferentes cirurgiões, projetamos uma prótese sob medida com modificações relevantes.
Effectiveness and acceptability of conversational agents for sexual health promotion: a systematic review and meta-analysis
Authors: Balaji Divyaa , He Linwei , Giani Stefano , Bosse Tibor , Wiers Reinout , de Bruijn Gert-Jan
Published: July 2022

Digital health interventions for sexual health promotion have evolved considerably alongside innovations in technology. Despite these efforts, studies have shown that they do not consistently result in the desired sexual health outcomes. This could be attributed to low levels of user engagement, which can hinder digital health intervention effectiveness, as users do not engage with the system enough to be exposed to the intervention components. It has been suggested that conversational agents (automated two-way communication systems e.g. Alexa) have the potential to overcome the limitations of prior systems and promote user engagement through the increased interactivity offered by bidirectional, natural language-based interactions. The present review, therefore, provides an overview of the effectiveness and user acceptability of conversational agents for sexual health promotion. A systematic search of seven databases provided 4534 records, and after screening, 31 articles were included in this review. A narrative synthesis of results was conducted for effectiveness and acceptability outcomes, with the former supplemented by a meta-analysis conducted on a subset of studies. Findings provide preliminary support for the effectiveness of conversational agents for promoting sexual health, particularly treatment adherence. These conversational agents were found to be easy to use and useful, and importantly, resulted in high levels of satisfaction, use and intentions to reuse, whereas user evaluations regarding the quality of information left room for improvement. The results can inform subsequent efforts to design and evaluate these interventions, and offer insight into additional user experience constructs identified outside of current technology acceptance models, which can be incorporated into future theoretical developments.
Molecular mechanism of the severe MH/CCD mutation Y522S in skeletal ryanodine receptor (RyR1) by cryo-EM
Authors: Iyer Kavita A. , Hu Yifan , Klose Thomas , Murayama Takashi , Samsó Montserrat
Published: July 2022

Ryanodine receptors (RyRs) are main regulators of intracellular Ca
2+
release and muscle contraction. The Y522S mutation of RyR1 causes central core disease, a weakening myopathy, and malignant hyperthermia, a sudden and potentially fatal response to anesthetics or heat. Y522 is in the core of the N-terminal subdomain C of RyR1 and the mechanism of how this mutation orchestrates malfunction is unpredictable for this 2-MDa ion channel, which has four identical subunits composed of 15 distinct cytoplasmic domains each. We expressed and purified the RyR1 rabbit homolog, Y523S, from HEK293 cells and reconstituted it in nanodiscs under closed and open states. The high-resolution cryogenic electron microscopic (cryo-EM) three-dimensional (3D) structures show that the phenyl ring of Tyr functions in a manner analogous to a “spacer” within an α-helical bundle. Mutation to the much smaller Ser alters the hydrophobic network within the bundle, triggering rearrangement of its α-helices with repercussions in the orientation of most cytoplasmic domains. Examining the mutation-induced readjustments exposed a series of connected α-helices acting as an ∼100 Å-long lever: One end protrudes toward the dihydropyridine receptor, its molecular activator (akin to an antenna), while the other end reaches the Ca
2+
activation site. The Y523S mutation elicits channel preactivation in the absence of any activator and full opening at 1.5 µM free Ca
2+
, increasing by ∼20-fold the potency of Ca
2+
to activate the channel compared with RyR1 wild type (WT). This study identified a preactivated pathological state of RyR1 and a long-range lever that may work as a molecular switch to open the channel.
How liquid–liquid phase separation induces active spreading
Authors: Chao Youchuang , Ramírez-Soto Olinka , Bahr Christian , Karpitschka Stefan
Published: July 2022

The interplay between phase separation and wetting of multicomponent mixtures is ubiquitous in nature and technology and recently gained significant attention across scientific disciplines, due to the discovery of biomolecular condensates. It is well understood that sessile droplets, undergoing phase separation in a static wetting configuration, exhibit microdroplet nucleation at their contact lines, forming an oil ring during later stages. However, very little is known about the dynamic counterpart, when phase separation occurs in a nonequilibrium wetting configuration, i.e., spreading droplets. Here we show that liquid–liquid phase separation strongly couples to the spreading motion of three-phase contact lines. Thus, the classical Cox–Voinov law is not applicable anymore, because phase separation adds an active spreading force beyond the capillary driving. Intriguingly, we observe that spreading starts well before any visible nucleation of microdroplets in the main droplet. Using high-speed ellipsometry, we further demonstrate that the evaporation-induced enrichment, together with surface forces, causes an even earlier nucleation in the wetting precursor film around the droplet, initiating the observed wetting transition. We expect our findings to improve the fundamental understanding of phase separation processes that involve dynamical contact lines and/or surface forces, with implications in a wide range of applications, from oil recovery or inkjet printing to material synthesis and biomolecular condensates.
Two approaches for the passive charge management of contactless test masses
Authors: Wang S , Saraf S , Lipa J , Yadav D , Buchman S
Published: July 2022

Free floating test masses (TM) of inertial reference instruments accumulate charge mainly through the triboelectric effect during separation from their housings and, if in the space environment, from cosmic radiation. These charges will degrade the accuracy of high sensitivity accelerometers and drag-free sensors. We demonstrate in ground testing two passive bipolar charge management systems using photoelectrons emitted from gold coated surfaces under illumination by ultraviolet light emitting diodes (UV-LEDs) with 255 nm, 275 nm, and 295 nm central wavelengths. The first method uses fast photoelectrons, generated by two 255 nm UV-LEDs with adjustable-intensity (through fine-tuning of their excitation currents) and illuminating the TM and its housing respectively. A second technique uses slow photoelectrons generated by one UV-LED, of either 275 nm or 295 nm, directed at the TM. Fast and slow electrons are defined as having kinetic energies after photoemission above and below

e
V

T
M

max

, where

V

T
M

max

is the maximum allowable potential required for normal operation of the TM. In its optimized configurations and following an exposure of <30 s to UV, the fast-photoelectron control system converges to zero TM potential from ±1 V with a drift of ≈1.5 mV/day. The slow-photoelectron system requires about 5 min to converge to zero TM potential from 100 mV, with a similar drift of ≈2.0 mV/day. For reference,

V

T
M

max

≅
80

m
V

for the LISA and LISA pathfinder sensors. Insight into the slow photoelectrons charge control method is provided by our simple Gaussian model of the work function for gold films (that approximates their quasi-triangular measured shape): 4.6 eV center, 0.2 eV standard deviation, and 4.30 eV and 4.90 eV cutoffs. The longest wavelength (lowest energy) photoemission is obtained with the 295 nm LED (11 nm FWHM) at about 285 nm (4.35 eV), where only about 3.5% of the photons have an energy above the photoelectric threshold. While the two-source UV fast photoelectron method is a modification of the LISA Pathfinder approach, the slow photoelectron method is a new passive charge management technique. These two passive techniques were developed for instruments without sensing and activation systems. For instruments with electric fields surrounding the TM and more complex geometries additional adaptations are required.
Parameter estimation in fluid flow models from aliased velocity measurements
Authors: Garay Jeremías , Nolte David , Löcke Miriam , Bertoglio Cristóbal
Published: July 2022

Parameter estimation in blood flow models from measured velocity data—as e.g. velocity-encoded MRI—is a key step for patient-specific hemodynamic analysis. However, velocity encoding suffers from competing noise and aliasing artifacts, which negatively impact the parameter estimation results. The aim of this work is to propose a new inverse problem formulation capable of tackling aliased and noisy velocity MRI measurements in parameter estimation in flows. The formulation is based on a modification of the quadratic cost function for velocity measurements. This allows for a correct parameter estimation when they have influence on the whole measurement domain, in spite of aliasing artifacts. The new inverse problem can be solved numerically using any standard solver, and we show how a popular sequential approach can be applied. Numerical results in an aortic flow show robust parameter estimation for velocity encoding ranges until 30% of the maximal velocity of the problem, while the standard inverse problem fails already for any encoding velocity smaller than the true one. Moreover, the parameter estimation results are even improved for reduced velocity encoding ranges when using the new cost function. The presented approach allows therefore for great flexibility in personalization of blood flows models from MRI data commonly encountered in the clinical context.
Quantum confinement in chalcogenides 2D nanostructures from first principles
Authors: Das Tilak , Di Liberto Giovanni , Pacchioni Gianfranco
Published: July 2022

We investigated the impact of quantum confinement on the band gap of chalcogenides 2D nanostructures by means of density functional theory. We studied six different systems: MoS2, WS2, SnS2, GaS, InSe, and HfS2 and we simulated nanosheets of increasing thickness, ranging from ultrathin films to ∼10–13 nm thick slabs, a size where the properties converge to the bulk. In some cases, the convergence of the band gap with slab thickness is rather slow, and sizeable deviations from the bulk value are still present with few nm-thick sheets. The results of the simulations were compared with the available experimental data, finding a quantitative agreement. The impact of quantum confinement can be rationalized in terms of effective masses of electrons and holes and system’s size. These results show the possibility of reliably describing quantum confinement effects on systems for which experimental data are not available.
Improved compact model extraction of statistical variability in 5 nm nanosheet transistors and applied to SRAM simulations
Authors: Li Ruihan , Luo Haowen , Wang Yichen , Yuan Zhengwu , Asenov Asen , Miao Xiangshui , Wang Xingsheng
Published: July 2022

In this paper, we look at how artificial neural networks (ANNs) may be used to improve compact model extraction of statistical variability in 5 nm nanosheet transistors (NSTs) and how it can be applied to 6NST-static random access memory (SRAM) simulations. To begin, both the TCAD simulation platform and compact model of 3D n-type and p-type NST have been rigorously validated against the experimental data. The transfer characteristics curves of 1104 NST samples generated by metal gate granularity, random discrete dopants and line edge roughness are used to extract the important figures of merit (FoM) including ON-current (I
ON), OFF-current (I
OFF), threshold voltage (V
TH) and subthreshold slope. Meanwhile, we can collect the main compact model parameters of these NST samples using our automatic extraction technique. Furthermore, a multi-layer ANN engine is trained to anticipate the important compact model parameters by entering FoMs, which significantly speeds up the automatic extraction. When we compare the prediction results to the genuine values, we discover that their correlation coefficients are all larger than 0.99. Finally, we simulated the 6NST-SRAM circuit and obtained its stability variation, with the help of extracted NST variability by the aforementioned speedup techniques.
Inducing spin-order with an impurity: phase diagram of the magnetic Bose polaron
Authors: Mistakidis S I , Koutentakis G M , Grusdt F , Schmelcher P , Sadeghpour H R
Published: July 2022

We investigate the formation of magnetic Bose polaron, an impurity atom dressed by spin-wave excitations, in a one-dimensional spinor Bose gas. Within an effective potential model, the impurity is strongly confined by the host excitations which can even overcome the impurity-medium repulsion leading to a self-localized quasi-particle state. The phase diagram of the attractive and self-bound repulsive magnetic polaron, repulsive non-magnetic (Fröhlich-type) polaron and impurity-medium phase-separation regimes is explored with respect to the Rabi-coupling between the spin components, spin–spin interactions and impurity-medium coupling. The residue of such magnetic polarons decreases substantially in both strong attractive and repulsive branches with strong impurity-spin interactions, illustrating significant dressing of the impurity. The impurity can be used to probe and maneuver the spin polarization of the magnetic medium while suppressing ferromagnetic spin–spin correlations. It is shown that mean-field theory fails as the spinor gas approaches immiscibility since the generated spin-wave excitations are prominent. Our findings illustrate that impurities can be utilized to generate controllable spin–spin correlations and magnetic polaron states which can be realized with current cold atom setups.
Impact of amplified spontaneous emission noise on the SRS threshold of high-power fiber amplifiers
Authors: Liu Wei , Ren Shuai , Ma Pengfei , Zhou Pu
Published: July 2022

Impact of amplified spontaneous emission (ASE) noise on the stimulated Raman scattering (SRS) threshold of high-power fiber amplifiers is demonstrated numerically through a spectral evolution approach. The simulation results confirm that ASE noise in the Raman wavelength band could reduce the SRS threshold of high-power fiber amplifiers significantly. As for ASE noise originated the main amplifier, it becomes stronger and reduces the SRS threshold at shorter operation wavelength below 1052 nm. As for ASE noise originated from the seed laser, it reduces the SRS threshold at different operation wavelength under the condition that the Raman ratio is over –90 dB in the seed laser. The theoretical method and results in this work could provide a well reference to extend the operation wavelength of high-power fiber lasers.
In situ temperature measurement of vapor based on atomic speed selection
Authors: Yu Lu , Cao Li , Yue Ziqian , Li Lin , Zhai Yueyang
Published: July 2022

We demonstrate an experimental method for the in situ temperature measurement of atomic vapor using the saturated absorption spectrum. By separately manipulating the frequency of the pump and probe beams, the position of the crossover peaks can move along the spectrum. Different velocity classes of atoms contribute to the crossover during the movement. We study the relationship between the intensity change of peaks and vapor temperature. Our experimental result around room temperature shows a deviation of less than 0.3 K. Compared with traditional thermometry using absorption spectroscopy, higher accuracy can theoretically be achieved with real-time thermometry.
Anisotropy of 2H-NbSe2 in the superconducting and charge density wave states
Authors: Zhang Chi , Qiao Shan , Xiao Hong , Hu Tao
Published: July 2022

Anisotropy is an important feature of layered materials, and a large anisotropy is usually related to the two-dimensional characteristics. We investigated the anisotropy of the layered transition metal dicalcogenide 2H-NbSe2 in the superconducting and charge density wave (CDW) states using magnetotransport measurements. In the superconducting state, the normalized

H

c
2

|
|
c

/

H
p

is independent of the thickness of 2H-NbSe2, while

H

c
2

|
|
a
b

/

H
p

increases significantly with decreasing thickness, where H
p is the Pauli limiting magnetic field and

H

c
2

|
|
c

and

H

c
2

|
|
a
b

are the upper critical fields in the c and ab directions, respectively. It is found that the superconducting anisotropy parameter

γ

H

c
2

=

H

c
2

|
|
a
b

/

H

c
2

|
|
c

increases with reduction in the thickness of 2H-NbSe2. In the CDW state, the angular (θ) dependence of magnetoresistance, R(H,θ) scales with

H

(

cos

2

θ
+

γ

CDW

−
2

sin

2

θ
)

1
/
2

, which decreases with increasing temperature and disappears at about 40 K. It is found that the CDW anisotropy parameter γ
CDW is much larger than the effective mass anisotropy but does not change a lot for ultrathin and bulk samples. Our results suggest the existence of three-dimensional superconductivity and quasi-two dimensional CDWs in bulk 2H-NbSe2.
Electron beam pumping improves the conversion efficiency of low-frequency photons radiated by perovskite quantum dots
Authors: Du Peng , Mu Yining , Ren Hang , Tafur Monroy Idelfonso , Li Yan-Zheng , Fan Hai-Bo , Wang Shuai , Ibrahim Makram , Liang Dong
Published: July 2022

This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion. Firstly, we measure the random lasing threshold and luminescence threshold of CsPbX
3 films pumped by an electron beam. Then, we simulate the spatial distribution of the electron beams in CsPbX
3 films. Combined with the above data, a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented. This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.
TiO2/SnO2 electron transport double layers with ultrathin SnO2 for efficient planar perovskite solar cells
Authors: Li Can , Xu Hongyu , Zhi Chongyang , Wan Zhi , Li Zhen
Published: July 2022

The electron transport layer (ETL) plays an important role on the performance and stability of perovskite solar cells (PSCs). Developing double ETL is a promising strategy to take the advantages of different ETL materials and avoid their drawbacks. Here, an ultrathin SnO2 layer of ∼ 5 nm deposited by atomic layer deposit (ALD) was used to construct a TiO2/SnO2 double ETL, improving the power conversion efficiency (PCE) from 18.02% to 21.13%. The ultrathin SnO2 layer enhances the electrical conductivity of the double layer ETLs and improves band alignment at the ETL/perovskite interface, promoting charge extraction and transfer. The ultrathin SnO2 layer also passivates the ETL/perovskite interface, suppressing nonradiative recombination. The double ETL achieves outstanding stability compared with PSCs with TiO2 only ETL. The PSCs with double ETL retains 85% of its initial PCE after 900 hours illumination. Our work demonstrates the prospects of using ultrathin metal oxide to construct double ETL for high-performance PSCs.
Growth and characterization of superconducting Ca1–x
Na
x
Fe2As2 single crystals by NaAs-flux method
Authors: Zhou Hong-Lin , Zhang Yu-Hao , Li Yang , Li Shi-Liang , Hong Wen-Shan , Luo Hui-Qian
Published: July 2022

High-quality superconducting Ca1−x
Na
x
Fe2As2 single crystals have been successfully grown by the NaAs-flux method, with sodium doping level x = 0.4–0.64. The typical sizes of these crystals are more than 10 mm in ab-plane and ∼ 0.1 mm along c-axis in thickness. X-ray diffraction, resistance and magnetization measurements are carried out to characterize the quality of these crystals. While no signature of magnetic phase transitions is detected in the normal state, bulk superconductivity is found for these samples, with a sharp transition at T
c ranging from 19.8 K (x = 0.4) to 34.8 K (x = 0.64). The doping dependences of the c-axis parameter and T
c are consistent with previous reports, suggesting a possible connection between the lattice parameters and superconductivity.
Comment on ‘Egypt’s water budget deficit and suggested mitigation policies for the Grand Ethiopian Renaissance Dam filling scenarios’
Authors: Eladawy Ahmed , Asefa Tirusew , El Nour Saker
Published: July 2022

The Grand Ethiopian Renaissance Dam (GERD) filling and operation is a highly sensitive issue for Egypt and Sudan. A recently accepted manuscript by Heggy et al (2021 Environ. Res. Lett.
16 074022) assessed the water deficit for Egypt based on different scenarios for the first filling of GERD lake and estimated 31 billion cubic meters per year under a 3 year filling scenario. We would like to present grossly mischaracterized assumptions, inaccurate data, and controversial conclusions found in this accepted manuscript through this rebuttal. Although the accepted manuscript does not include any new analysis of the River Nile Hydrology, the results of previous substantive studies were misinterpreted or ignored. Moreover, we have serious concerns about the basic hydrological assumptions that are the basis for the economic impacts and the potential loss of the Egyptian agricultural lands. The main methodological flaws of concerns are (a) how the deficit is calculated, losses from GERD, especially the evaporation losses that contradicts several previous studies (e.g. Wheeler et al 2016 Water Int.
41 611–34; Eldardiry and Hossain 2020 J. Hydrol. 125708; Wheeler et al 2020 Nat. Commun.
11 1–9); (b) neglecting the normal role of High Aswan Dam (HAD) reservoir and directly linking the deficit of the water budget to an immediate loss of agricultural lands with all other associated exaggerated economic impacts estimates; (c) including highly exaggerated seepage losses from the GERD lake; (d) neglecting the updated situation of Aswan High Dam reservoir levels and the GERD’s infrastructure itself, and (e) quantifying the impacts of potential changes of water level on HAD reservoir on the Nubian aquifer. We herein present a direct fact-checking approach including the studies cited in the accepted manuscript. We believe that this critical comment paper can serve as a basis for defending scientific integrity and contributes to cooperation and peace in the region.
Combined impact of the cold vortex and atmospheric blocking on cold outbreaks over East Asia and the potential for short-range prediction of such occurrences
Authors: Zhuo Wenqin , Yao Yao , Luo Dehai , Simmonds Ian , Huang Fei
Published: July 2022

This study explores the consequences of independent and combined effects of blockings on the northeast Asian cold vortex (NACV), and corresponding cold outbreaks over East Asia (EA) during boreal winters of 1979–2019. The results show that the development of NACV is closely associated with blocking over the Ural Mountains (UB) upstream and eastern Siberia to mid-North Pacific (SPB) downstream. Here we focus on the initial periods before the peak day of NACV events. It is found that the strong NACV events are usually induced by the initial-UB situation, leading to the greatest temperature drop in EA. While the weak NACV events may be associated with the initial-SPB condition, which can bring less dramatic outbreaks but longer duration, owing to the Ural ridge that formed by the westward shift of SPB. Furthermore, an SPB-UB relay effect is discovered against the background of a negative Arctic Oscillation pattern. In such cases, UB is formed by the westward shift of downstream SPB after the occurrence of NACV, forming a relay effect that motivates the second NACV process, hence prolonging the duration of cold anomalies in EA. These findings highlight the importance of the combined effect of blockings and NACV in the intraseasonal time scale. Compared to the ‘Initial-UB’ and ‘Initial-SPB’ situation, this ‘SPB-UB relay’ scenario can produce longer-lasting cold extreme in EA, which may be indicative of the short-term weather forecasting of such extreme cold weather.
Minimizing couplings in renormalization by preserving short-range mutual information
Authors: Bertoni Christian , Renes Joseph M
Published: July 2022

The connections between renormalization in statistical mechanics and information theory are intuitively evident, but a satisfactory theoretical treatment remains elusive. We show that the real space renormalization map that minimizes long range couplings in the renormalized Hamiltonian is, somewhat counterintuitively, the one that minimizes the loss of short-range mutual information between a block and its boundary. Moreover, we show that a previously proposed minimization focusing on preserving long-range mutual information is a relaxation of this approach, which indicates that the aims of preserving long-range physics and eliminating short-range couplings are related in a nontrivial way.
Non-invasive diagnostics of pathogenic bacteria using a breath sampler in children with cystic fibrosis
Authors: van Aerde Koen J , Leegstraten Aniek , van den Kieboom Corné H , Merkus Peter , Sintnicolaas Coosje , Simons Sami O , van der Flier Michiel , de Groot Ronald , de Jonge Marien I
Published: July 2022

Cystic fibrosis (CF) is a common autosomal recessive disease causing thick, viscous secretions leading to pulmonary infections with pathogenic bacteria. As part of routine patient care, colonization and infection with these bacteria is monitored with cough swab or sputum cultures and sometimes bronchoalveolar lavage. In this cross-sectional proof-of-concept study in a cohort of CF patients we collected swabs or sputa and exhaled breath samples with the modular breath sampler (MBS), a newly developed two-way non-rebreathing sampling device. Pathogen specific polymerase chain reactions (PCRs) were performed on the MBS samples and compared with the results obtained with conventional diagnostics (i.e. culturing of swabs and sputa). A control group of stable asthma patients was used as negative control for the MBS measurements. The pathogens detected using MBS and conventional culturing differed: S. aureus was found more often in swab or sputum samples whereas Pseudomonas aeruginosa and S. pneumoniae were found more often in MBS samples. We hypothesize that this is due to sampling of different compartments, MBS samples are derived from the lower respiratory tract while cultures from cough swabs and sputa are dominated by pathogens residing in the upper respiratory tract. Another important difference is the readout, i.e. culture versus PCR. The majority of CF patients in whom P. aeruginosa was found did not have recent positive cultures suggesting higher sensitivity of MBS-based than conventional diagnostics. The majority of parents/patients found the MBS easy to use and less of a burden than respiratory sampling.
Correlation between blood ketones and exhaled acetone measured with a semiconducting gas sensor
Authors: Tsunemi Shingo , Nakamura Yuta , Yokota Kenichi , Nakagawa Tomoko , Tsukiyama Hidekazu , Kubo Yui , Oyanagi Takeshi , Takemoto Ayaka , Nagai Yoshio , Tanaka Yasushi , Sone Masakatsu
Published: July 2022

Breath acetone (BrAce) has been reported to be useful for monitoring the pathophysiology of patients with diabetes. However, devices that measure BrAce are expensive, complex and uncommon. The FM-001, originally designed to monitor a marker of weight loss in healthy people, is a device for measuring BrAce. The FM-001 is a loading semiconducting gas sensor that is a simple and reusable device. The aim of this study was to evaluate the correlation between blood total ketone bodies (TKB) and BrAce measured with the FM-001 in patients with diabetes. Furthermore, through evaluation of that correlation, we sought to detect patients at high risk of developing diabetic ketoacidosis (DKA). Thirty-five participants (age 52 [40–57], T2DM 32, T1DM 3) were enrolled. Scatter plots and linear regression lines relating BrAce to TKB and the correlation coefficients were calculated. Receiver-operating characteristic analysis was performed to determine the cut-off for predicting patients prone to DKA. The results showed that BrAce strongly correlates with TKB (R = 0.828), and the correlation was stronger in patients whose serum C-peptide was not low. The optimal BrAce cut-off for predicting risk of developing DKA was 3400 ppb (AUC 0.924, sensitivity 73.3%, specificity 100%), which corresponds to a TKB ⩾ 1000 µmol l−1. BrAce also weakly correlated with free fatty acid. Thus, BrAce levels measured with the FM-001 strongly correlate with TKB, even in patients with diabetes. This suggests the FM-001 is a simple and potentially useful method for detecting diabetic ketosis. (UMIN-ID: UMIN000038086)
An experimental investigation on enhancing the strength and stiffness of GFRP co-cured composite joint: effect of glass powder addition
Authors: Vijaya Rajan V , Gnanavel B K
Published: July 2022

Co-cure adhesive joints are preferred by various industries, namely, automobile, marine and aerospace, to join two surfaces in structural applications, as a useful replacement for mechanical fastenings. The present work focusses on the mechanical properties and free vibration behaviour of co-cured glass fiber compositesreinforced with glass powder. In the course of the experimentation, the adhesive is being reinforced concurrently with glass powder in four different weight percentages, such as 0%, 0.5%, 1%, 1.5% and 2%. The mechanical testing results reveal that the addition of 1.5% of glass powder to the epoxy could relatively help in increasing the tensile strength and flexural strength of the co-cured glass fiber composites respectively to the degree of 11.68% (364.29 Mpa) and 24.75% (256.16 Mpa). The Single lap shear results show that the 0.5% glass powder reinforcement significantly increases the shear strength of the cocured glass fiber composites by 20.91% (19.31 Mpa). Furthermore, the free vibrational study of 1.5% co-cured composites shows that they have a higher fundamental natural frequency than the glass powder reinforced co-cured composites that have a lower weight percentage. Furthermore, the addition of glass powder to the co-cured composites helps in increasing the damping factor of the composites due to the glass powder agglomeration. Neat and glass powder reinforced co-cured samples are further analysed afterwards, using the mechanical and shear test by scanning electron microscopy.
Investigation of radial heat conduction with 1D self-consistent model in helicon plasmas
Authors: TIAN Bin , MERINO Mario , WAN Jie , HU Yuan , CAO Yong
Published: July 2022

A 1D radially self-consistent model in helicon plasmas has been established to investigate the influence of radial heat conduction on plasma transport and wave propagation. Two kinds of 1D radial fluid models, with and without considering heat conduction, have been developed to couple the 1D plasma–wave interaction model, and self-consistent solutions have been obtained. It is concluded that in the low magnetic field range the radial heat conduction plays a moderate role in the transport of helicon plasmas and the importance depends on the application of the helicon source. It influences the local energy balance leading to enhancement of the electron temperature in the bulk region and a decrease in plasma density. The power deposition in the plasma is mainly balanced by collisional processes and axial diffusion, whereas it is compensated by heat conduction in the bulk region and consumed near the boundary. The role of radial heat conduction in the large magnetic field regime becomes negligible and the two fluid models show consistency. The local power balance, especially near the wall, is improved when conductive heat is taken into account.
A study of the influence of different grid structures on plasma characteristics in the discharge chamber of an ion thruster
Authors: SUN Mingming , LONG Jianfei , GUO Weilong , LIU Chao , ZHAO Yong
Published: July 2022

The grid structure has significant effects on the discharge characteristics of an ion thruster. The discharge performances of a 30 cm diameter ion thruster with flat, convex and concave grids are studied. The analysis results show that the discharge chamber with a convex grid has a larger ‘magnetic-field free area’ than the others, and the parallelism of the magnetic-field isopotential lines and anode is generally the same in the three models. Plasma densities of the three structures at the grid outlet are in the range of 3.1 × 1016–6.9 × 1017 m−3. Along the thruster axis direction, the electron temperature in the chamber with the convex and concave grids is in the range of 3.3–3.5 eV, while that with a flat grid is lower, in the range of 3.1–3.5 eV. In addition, the convex and the concave grids have better uniform distribution of electron temperature. Moreover, the collision frequency ratios show that the axial degree of ionization of the three models is the highest, and the flat grid has the highest discharge efficiency, followed by the convex grid and the concave grid is the least efficient. The test and simulation results of the 30 cm diameter ion thruster with the convex grid show that the measurement and calculation results are 3.67 A and 3.44 A, respectively, and the error above mainly comes from the ignorance of the doubly charged ions and parameter settings in the model. The comparison error between the simulation and measurement of beam current density is mainly caused by the actual thermal deformation of the grids during the discharge process, which leads to the change in electric potential distribution and variation of the focusing characteristics of the grids. Upon consideration of discharge performance and the thermal grid gap variation, it can be concluded that the flat and concave grids are more suitable for small-diameter ion thrusters, while the convex grid is a more reasonable choice for the higher-power and larger-diameter thrusters.
Adapting a Persian Magic Realist Novel on Screen: The Case of Women Without Men
Authors: Zahedi Farshad
Published: July 2022

This paper will explore Shirin Neshat’s adaptation of Shahrnush Parsipur’s novel Women Without Men (1989). A primary focus will be on Neshat’s aesthetic choices related to the creation of space and the depiction of bodies and the extent to which they reflect her exilic condition. Another distinctive aspect to be explored concerns the dialectical relations in the film that visually depict gendered spaces inside homes and in public spaces. A related area here is the representation of an orchard as a heterotopian third space that gives shelter to wounded women. While both the novel and the film portray this orchard as a place of becoming, the film’s garden contains allegorical relations that portray it as a place of imaginary exile. Finally, the paper will argue that the portrayal of wounded female bodies is a political sign and a metaphor for women’s traumatic experiences of patriarchal culture.
Functional trade-offs in volume allocation to xylem cell types in 75 species from the Brazilian savanna Cerrado
Authors: Dória Larissa Chacon , Sonsin-Oliveira Julia , Rossi Sergio , Marcati Carmen Regina
Published: July 2022

Background and Aims

Xylem is a crucial tissue for plant survival, performing the functions of water transport, mechanical support and storage. Functional trade-offs are a result of the different assemblages of xylem cell types within a certain wood volume. We assessed how the volume allocated to different xylem cell types can be associated with wood functional trade-offs (hydraulics, mechanical and storage) in species from the Cerrado, the Brazilian savanna. We also assessed the xylem anatomical characters linked to wood density across species.

Methods

We analysed cross-sections of branches collected from 75 woody species belonging to 42 angiosperm families from the Cerrado. We estimated the wood volume fraction allocated to different cell types and performed measurements of vessel diameter and wood density.

Key Results

The largest volume of wood is allocated to fibres (0.47), followed by parenchyma (0.33) and vessels (0.20). Wood density is positively correlated to cell wall (fibre and vessel wall), and negatively to the fractions of fibre lumen and gelatinous fibres. We observed a trade-off between hydraulics (vessel diameter) and mechanics (cell wall fraction), and between mechanics and storage (parenchyma fraction). The expected positive functional relationships between hydraulics (vessel diameter) and water and carbohydrate storage (parenchyma and fibre lumen fractions) were not detected, though larger vessels are linked to a larger wood volume allocated to gelatinous fibres.

Conclusions

Woody species from the Cerrado show evidence of functional trade-offs between water transport, mechanical support and storage. Gelatinous fibres might be potentially linked to water storage and release by their positive relationship to increased vessel diameter, thus replacing the functional role of parenchyma and fibre lumen cells. Species can profit from the increased mechanical strength under tension provided by the presence of gelatinous fibres, avoiding expensive investments in high wood density.
ShinySyn: a Shiny/R application for the interactive visualization and integration of macro- and micro-synteny data
Authors: Xiao Zhixia , Lam Hon-Ming
Published: July 2022

Motivation

Synteny analysis is a widely used framework in comparative genomics studies, which provides valuable information to reveal chromosome collinearity in both intra-species and inter-species. Most analysis pipelines, however, are command line-based, making it challenging for biologists to run the algorithms and visualize the results. Existing visualization tools either provide static plots or can only be run on web-based servers and lack efficient visualization methods for associating macro-synteny blocks with individual gene pairs in a micro-synteny region.

Results

We developed ShinySyn, a Shiny/R application built on the MCscan framework that provides an easy-to-use graphic interface for synteny analyses without requiring any programming skills, to reduce technical barriers. ShinySyn not only provides interactive visualization for macro-synteny, micro-synteny and genome-level dot views, but it also creates an intuitive representation with a dynamic zooming feature from macro-synteny to individual homologous genes.

Availability and implementation

The source code and installation instructions for ShinySyn can be accessed via https://github.com/obenno/ShinySyn. A pre-built docker image is also available at https://hub.docker.com/r/obenno/shinysyn. The application can be used locally or seamlessly integrated into any Shiny application server.
Optical imaging detects metabolic signatures associated with oocyte quality
Authors: Tan Tiffany C Y , Brown Hannah M , Thompson Jeremy G , Mustafa Sanam , Dunning Kylie R
Published: July 2022

Oocyte developmental potential is intimately linked to metabolism. Existing approaches to measure metabolism in the cumulus oocyte complex (COC) do not provide information on the separate cumulus and oocyte compartments. Development of an assay that achieves this may lead to an accurate diagnostic for oocyte quality. Optical imaging of the autofluorescent cofactors reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] and flavin adenine dinucleotide (FAD) provides a spatially resolved indicator of metabolism via the optical redox ratio (FAD/[NAD(P)H + FAD]). This may provide an assessment of oocyte quality. Here, we determined whether the optical redox ratio is a robust methodology for measuring metabolism in the cumulus and oocyte compartments compared with oxygen consumption in the whole COC. We also determined whether optical imaging could detect metabolic differences associated with poor oocyte quality (etomoxir-treated). We used confocal microscopy to measure NAD(P)H and FAD, and extracellular flux to measure oxygen consumption. The optical redox ratio accurately reflected metabolism in the oocyte compartment when compared with oxygen consumption (whole COC). Etomoxir-treated COCs showed significantly lower levels of NAD(P)H and FAD compared to control. We further validated this approach using hyperspectral imaging, which is clinically compatible due to its low energy dose. This confirmed lower NAD(P)H and FAD in etomoxir-treated COCs. When comparing hyperspectral imaged vs non-imaged COCs, subsequent preimplantation development and post-transfer viability were comparable. Collectively, these results demonstrate that label-free optical imaging of metabolic cofactors is a safe and sensitive assay for measuring metabolism and has potential to assess oocyte developmental competence.
SARS-CoV-2 triggers pericyte-mediated cerebral capillary constriction
Authors: Hirunpattarasilp Chanawee , James Greg , Kwanthongdee Jaturon , Freitas Felipe , Huo Jiandong , Sethi Huma , Kittler Josef T , Owens Raymond J , McCoy Laura E , Attwell David
Published: July 2022

The SARS-CoV-2 receptor, ACE2, is found on pericytes, contractile cells enwrapping capillaries that regulate brain, heart and kidney blood flow. ACE2 converts vasoconstricting angiotensin II into vasodilating angiotensin-(1-7). In brain slices from hamster, which has an ACE2 sequence similar to human ACE2, angiotensin II evoked a small pericyte-mediated capillary constriction via AT1 receptors, but evoked a large constriction when the SARS-CoV-2 receptor binding domain (RBD, original Wuhan variant) was present. A mutated non-binding RBD did not potentiate constriction. A similar RBD-potentiated capillary constriction occurred in human cortical slices, and was evoked in hamster brain slices by pseudotyped virions expressing SARS-CoV-2 spike protein. This constriction reflects an RBD-induced decrease in the conversion of angiotensin II to angiotensin-(1-7) mediated by removal of ACE2 from the cell surface membrane and was mimicked by blocking ACE2. The clinically used drug losartan inhibited the RBD-potentiated constriction. Thus, AT1 receptor blockers could be protective in COVID-19 by preventing pericyte-mediated blood flow reductions in the brain, and perhaps the heart and kidney.
Structural disconnection and functional reorganization in Fabry disease: a multimodal MRI study
Authors: Gabusi Ilaria , Pontillo Giuseppe , Petracca Maria , Battocchio Matteo , Bosticardo Sara , Costabile Teresa , Daducci Alessandro , Pane Chiara , Riccio Eleonora , Pisani Antonio , Brunetti Arturo , Schiavi Simona , Cocozza Sirio
Published: July 2022

Central nervous system involvement in Fabry disease, a rare systemic X-linked lysosomal storage disorder, is characterized by the presence of heterogeneous but consistent functional and microstructural changes. Nevertheless, knowledge about the degree and extension of macro-scale brain connectivity modifications is to date missing. In this work, we performed connectomic analyses of diffusion and resting-state functional MRI to investigate changes of both structural and functional brain organization in Fabry disease, as well as to explore the relationship between the two and their clinical correlates. In this retrospective cross-sectional study, 46 patients with Fabry disease (28F, 42.2 ± 13.2years) and 49 healthy controls (21F, 42.3 ± 16.3years) were included. All subjects underwent an MRI examination including anatomical, diffusion and resting-state functional sequences. Images were processed to obtain quantitative structural and functional connectomes, where the connections between regions of interest were weighted by the total intra-axonal signal contribution of the corresponding bundle and by the correlation between blood-oxygen level–dependent time series, respectively. We explored between-group differences in terms of both global network properties, expressed with graph measures and specific connected subnetworks, identified using a network-based statistics approach. As exploratory analyses, we also investigated the possible association between cognitive performance and structural and functional connectome modifications at both global and subnetwork level in a subgroup of patients (n = 11). Compared with healthy controls, patients with Fabry disease showed a significantly reduced global efficiency (P = 0.005) and mean strength (P < 0.001) in structural connectomes, together with an increased modularity (P = 0.005) in functional networks. As for the network-based statistics analysis, a subnetwork with decreased structural connectivity in patients with Fabry disease compared with healthy controls emerged, with eight nodes mainly located at the level of frontal or deep grey-matter areas. When probing the relation between altered global network metrics and neuropsychological tests, correlations emerged between the structural and functional disruption with results at verbal and working memory tests, respectively. Furthermore, structural disruption at subnetwork level was associated with worse executive functioning, with a significant moderation effect of functional changes suggesting a compensation mechanism. Taken together, these results further expand the current knowledge about brain involvement in Fabry disease, showing widespread structural disconnection and functional reorganization, primarily sustained by loss in axonal integrity and correlating with cognitive performance.