bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly (vinyl alcohol)/Polyquaternium-7 Anion Exchange Membranes for Alkaline Polymer Electrolyte Fuel Cells
Authors: Samsudin Asep Muhamad , Abdullah Abdullah , Nasher Kharissa , Kamal Mutiara Tabitha
Published: March 2024

Anion exchange membrane (AEM) is one of the critical components in Alkaline polymer electrolyte fuel cells. This is due to the crucial function in facilitating the process of hydroxide ion conduction. A series of anion exchange membranes (AEMs) were synthesized using poly (vinyl alcohol) (PVA) as the backbone polymer and polyquaternium-7 as the copolymer that provides a hydroxide conducting group source. Thermal and chemical crosslinking was introduced to reduce the excessive swelling of the membranes. The effect of the PVA/PQ7 mass ratio on AEMs performance was investigated. The FTIR study reveals that the spectra exhibit the primary functional groups of PVA, polyquaternium-7, and chemical crosslinking. According to the SEM image, the PVA/PQ7 membranes have smooth and uniform morphology. Water uptake and swelling degree increased with increasing mass ratio of polyquaternium-7 to PVA. AEMs with a polyquaternium-7 to PVA ratio of 0.5 provide the highest IEC and hydroxide conductivity values of 1.52 mmol/g and 9.26 mS/cm at room temperature, respectively.
Improving the corrosion protection of plasma electrolysis-treated light metal by polymeric functionalization
Authors: Kamil Muhammad Prisla , Suhartono Tri , Kozin Muhammad , Puranto Prabowo , Ulfah Ika Maria , Fitriani Diah Ayu , Azahra Siti Amalina , Ko Young Gun
Published: March 2024

Suppressing the rate of corrosive degradation has been the primary challenge in the widespread use of lightweight metals across a variety of potential applications because their native passive layer is still susceptible to chemical attacks in aqueous or humid environments. This work explores the roles of polyaniline in tandem with a TiO2 layer in improving the corrosion properties of pure Ti. The anodic TiO2 surface is a result of a plasma electrolysis treatment in a non-acidic, phosphate-based electrolyte. The emeraldine base form of the polymer is subsequently applied to modify the surface properties of the plasma-electrolyzed Ti samples to further protect the surface against polar species that might interact with TiO2. The deposition of the thin layer of polyaniline retains the original surface microstructure of the plasma electrolysis layer. Nevertheless, the presence of polyaniline successfully reduces the corrosion current density and passive current density of plasma-electrolyzed Ti by ~50%. The corrosion protection mechanism is explained in the context of equivalent circuit models based on impedance measurements.
NIKA2 observations of 3 low-mass galaxy clusters at z ~ 1: Pressure profile and YSZ – M relation
Authors: Adam R. , Ricci M. , Eckert D. , Ade P. , Ajeddig H. , Altieri B. , André P. , Artis E. , Aussel H. , Beelen A. , Benoist C. , Benoît A. , Berta S. , Bing L. , Birkinshaw M. , Bourrion O. , Boutigny D. , Bremer M. , Calvo M. , Cappi A. , Catalano A. , De Petris M. , Désert F.-X. , Doyle S. , Driessen E.F.C. , Faccioli L. , Ferrari C. , Gastaldello F. , Giles P. , Gomez A. , Goupy J. , Hahn O. , Hanser C. , Horellou C. , Kéruzoré F. , Koulouridis E. , Kramer C. , Ladjelate B. , Lagache G. , Leclercq S. , Lestrade J.-F. , Macías-Pérez J.F. , Madden S. , Maughan B. , Maurogordato S. , Maury A. , Mauskopf P. , Monfardini A. , Muñoz-Echeverría M. , Pacaud F. , Perotto L. , Pierre M. , Pisano G. , Pompei E. , Ponthieu N. , Revéret V. , Rigby A. , Ritacco A. , Romero C. , Roussel H. , Ruppin F. , Sereno M. , Schuster K. , Sievers A. , Vidal G. Tintoré , Tucker C. , Zylka R.
Published: March 2024

Three galaxy clusters selected from the XXL X-ray survey at high redshift and low mass (z ~ 1 and M500 ~ 1 – 2 × 1014 M⊙) were observed with NIKA2 to image their Sunyaev-Zel'dovich effect (SZ) signal. They all present an SZ morphology, together with the comparison with X-ray and optical data, that indicates dynamical activity related to merging events. Despite their disturbed intracluster medium, their high redshifts, and their low masses, the three clusters follow remarkably well the pressure profile and the SZ flux-mass relation expected from standard evolution. This suggests that the physics that drives cluster formation is already in place at z ~ 1 down to M500 ~ 1014 M⊙.
The case for an all-sky millimetre survey at subarcminute resolution
Authors: Désert François-Xavier , Calvo Martino , Catalano Andrea , Leclercq Samuel , Macias-Perez Juan , Mayet Frédéric , Monfardini Alessandro , Perotto Laurence , Ponthieu Nicolas
Published: March 2024

There are several new projects to survey the sky with millimetre eyes, the biggest being Simons Observatory and CMB-S4, in the Southern Hemisphere. The NIKA2 collaboration has acquired sufficient knowledge to build a large focal plane KID camera for a 15 m antenna. This would allow covering the whole Northern Hemisphere in five years at subarcminute resolution and with milliJansky point-source sensitivity. We describe the main scientific drivers for such a project: the SZ sky, the high-redshift millimetre Universe and the interstellar medium in our Galaxy and the nearby galaxies. We also show briefly the main difficulties (scientific, organisational, technical and financial).
SAAVY machine learning program can determine 3D culture viability without harming cells
Authors: Shapiro Maura
Published: March 2024

Machine learning trained image analysis software can accurately determine culture viability without killing the cells, enabling longitudinal studies.
Adapting TeachABI to the local needs of Australian educators – a critical step for successful implementation
Authors: Drake Marnie , Scratch Shannon E. , Jackman Angela , Scheinberg Adam , Wilson Meg , Knight Sarah
Published: March 2024

Background The present study is the foundational project of TeachABI-Australia, which aims to develop and implement an accessible, nation-wide digital resource for educators to address their unmet acquired brain injury (ABI)-related professional learning needs. The aim of the present study was to identify the adaptations required to improve the suitability and acceptability of the TeachABI professional development module within the Australian education system from the perspectives of Australian educators. Methods The research design employed an integrated knowledge translation approach and followed the ADAPT Guidance for undertaking adaptability research. A purposive sample of eight educators eligible to teach primary school in Australia provided feedback on the module through a quantitative post-module feedback questionnaire and a qualitative semi-structured interview. Results Participants rated the acceptability of the module as ‘Completely Acceptable’ (Mdn = 5, IQR = 1), and reported ‘only Minor’ changes were required (Mdn = 2, IQR = 0.25) to improve the suitability to the Australian context. Qualitative analysis of transcripts revealed three broad categories: (1) the usefulness of TeachABI, (2) the local fit of TeachABI, and (3) pathways for implementing TeachABI in the local setting. Recommended adaptations to the module collated from participant feedback included changes to language, expansion of content, and inclusion of Australian resources, legislation, and videos. Conclusions TeachABI is acceptable to Australian educators but requires modifications to tailor the resource to align with the unique schooling systems, needs, and culture of the local setting. The systematic methodological approach to adaptation outlined in this study will serve as a guide for future international iterations of TeachABI.
Effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus (COVID-19) vaccination on male fertility
Authors: Chen Fei , Zhang Yunfei , Zhang Yingze , Li Yuqi , Ma Jiao , Qin Yining , Deng Shuwen , Zhang Yuhan , Wang Deyang , Wang Haiying , Lin Juan
Published: March 2024

Coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an ongoing global public health challenge. This disease causes damage not only to the respiratory system, affecting the normal physiological function of the lungs, but also to other vital organs, such as the heart and testicles. Existing studies have shown that co-expression of angiotensin-converting enzyme 2 and transmembrane serine protease 2 is the main mechanism by which SARS-CoV-2 invades host cells. Angiotensin-converting enzyme 2-expressing cells are widespread in the corpus cavernosum, reproductive tract and testis of men, which has raised concerns. Furthermore, abnormal sex hormone levels and decreased semen parameters were observed in coronavirus disease 2019 patients. This study comprehensively assessed the effects of SARS-CoV-2 infection on the testis, semen parameters, sex hormone levels and erectile function, and discussed possible transmission routes during sexual intercourse and the effect of vaccination on male fertility.
Classical vs. quantum plasmon-induced molecular transformations at metallic nanojunctions
Authors: Mantilla Alexander B. C. , Wang Chih-Feng , Krayev Andrey , Gu Yi , Schultz Zachary D. , El-Khoury Patrick Z.
Published: March 2024

Chemical transformations near plasmonic metals have attracted increasing attention in the past few years. Specifically, reactions occurring within plasmonic nanojunctions that can be detected via surface and tip-enhanced Raman (SER and TER) scattering were the focus of numerous reports. In this context, even though the transition between localized and nonlocal (quantum) plasmons at nanojunctions is documented, its implications on plasmonic chemistry remain poorly understood. We explore the latter through AFM-TER-current measurements. We use two molecules: i) 4-mercaptobenzonitrile (MBN) that reports on the (non)local fields and ii) 4-nitrothiophenol (NTP) that features defined signatures of its neutral/anionic forms and dimer product, 4,4′-dimercaptoazobenzene (DMAB). The transition from classical to quantum plasmons is established through our optical measurements: It is marked by molecular charging and optical rectification. Simultaneously recorded force and current measurements support our assignments. In the case of NTP, we observe the parent and DMAB product beneath the probe in the classical regime. Further reducing the gap leads to the collapse of DMAB to form NTP anions. The process is reversible: Anions subsequently recombine into DMAB. Our results have significant implications for AFM-based TER measurements and their analysis, beyond the scope of this work. In effect, when precise control over the junction is not possible (e.g., in SER and ambient TER), both classical and quantum plasmons need to be considered in the analysis of plasmonic reactions
Brain decoding of spontaneous thought: Predictive modeling of self-relevance and valence using personal narratives
Authors: Kim Hong Ji , Lux Byeol Kim , Lee Eunjin , Finn Emily S. , Woo Choong-Wan
Published: March 2024

The contents and dynamics of spontaneous thought are important factors for personality traits and mental health. However, assessing spontaneous thoughts is challenging due to their unconstrained nature, and directing participants’ attention to report their thoughts may fundamentally alter them. Here, we aimed to decode two key content dimensions of spontaneous thought—self-relevance and valence—directly from brain activity. To train functional MRI-based predictive models, we used individually generated personal stories as stimuli in a story-reading task to mimic narrative-like spontaneous thoughts (
n
= 49). We then tested these models on multiple test datasets (total
n
= 199). The default mode, ventral attention, and frontoparietal networks played key roles in the predictions, with the anterior insula and midcingulate cortex contributing to self-relevance prediction and the left temporoparietal junction and dorsomedial prefrontal cortex contributing to valence prediction. Overall, this study presents brain models of internal thoughts and emotions, highlighting the potential for the brain decoding of spontaneous thought.
Electrochemical synthesis of 2D-silver nanodendrites functionalized with cyclodextrin for SERS-based detection of herbicide MCPA
Authors: Daly Robert , Narayan Tarun , Diaz Fernando , Shao Han , Gutierrez Moreno Jose Julio , Nolan Michael , O’Riordan Alan , Lovera Pierre
Published: March 2024

Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique that has found application in the trace detection of a wide range of contaminants. In this paper, we report on the fabrication of 2D silver nanodendrites, on silicon chips, synthesized by electrochemical reduction of AgNO3 at microelectrodes. The formation of nanodendrites is tentatively explained in terms of electromigration and diffusion of silver ions. Electrochemical characterization suggests that the nanodendrites do not stay electrically connected to the microelectrode. The substrates show SERS activity with an enhancement factor on the order of 106. Density functional theory simulations were carried out to investigate the suitability of the fabricated substrate for pesticide monitoring. These substrates can be functionalized with cyclodextrin macro molecules to help with the detection of molecules with low affinity with silver surfaces. A proof of concept is demonstrated with the detection of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA).
General relativistic bubble growth in cosmological phase transitions
Authors: Giombi L. , Hindmarsh Mark
Published: March 2024

We use a full general relativistic framework to study the self-similar expansion of bubbles of the stable phase into a flat Friedmann-Lemaître-Robertson-Walker Universe in a first order phase transition in the early Universe. With a simple linear barotropic equation of state in both phases, and in the limit of a phase boundary of negligible width, we find that self-similar solutions exist, which are qualitatively similar to the analogous solutions in Minkowski space, but with distinguishing features. Rarefaction waves extend to the centre of the bubble, while spatial sections near the centre of the bubble have negative curvature.
Gravitational effects redistribute the kinetic energy of the fluid around the bubble, and can change the kinetic energy fraction significantly. The kinetic energy fraction of the gravitating solution can be enhanced over the analogous Minkowski solution by as much as 𝒪(1), and suppressed by a factor as larger as 𝒪(10) in case of fast detonations.
The amount of negative spatial curvature at the centre of the bubble is of the same order of magnitude of the naive expectation based on considerations of the energy density perturbation in Minkowski solutions, with gravitating deflagrations less negatively curved, and detonations more.
We infer that general relativistic effects might have a significant impact on
accurate calculations of the gravitational wave power spectrum when the bubble size becomes comparable to the cosmological Hubble radius,
affecting the primary generation from the fluid shear stress, and inducing secondary generation by scalar perturbations.
Erratum: Gravitational echoes of lepton number symmetry breaking with light and ultralight Majorons
Authors: Addazi Andrea , Marcianò Antonino , Morais António P. , Pasechnik Roman , Viana João , Yang Hao
Published: March 2024

We rectify a typographical error in equation (3.14) from the original version of this article, pertaining to the effective Higgs-Majoron coupling, λ(0)

JJh
1
, expressed in the mass eigenbasis. Notably, the same error persisted in the computational routines used in our work. This oversight resulted in a discrepancy in the numerical calculation of the invisible Higgs decay branching fraction, Br(h
1 → JJ), affecting a subset of the sampled points. While the main conclusions remain unaltered, we provide an updated version of our results.
Silicon carbide detectors for dosimetry and monitoring of ultra-high dose rate beams
Authors: Okpuwe C. , Amato A. , D'Amico I. , De Liso V. , De Napoli M. , Di Martino F. , Felici G. , Galluzzo L. , Medina E. , Vignati A. , Camarda M. , Romano F. , Milluzzo G.
Published: March 2024

FLASH radiotherapy, which employs ultra-high dose rate (UHDR) beams with a mean dose rate > 40 Gy/s and a total irradiation time < 200 ms to treat tumors, exhibits remarkable ability to spare healthy tissue while maintaining the same efficiency in treating tumors. However, UHDR presents challenges in dosimetry and beam monitoring, as the dosimeters recommended for conventional radiotherapy, i.e. the ionization chambers, show saturation at such high dose rates and dose delivered per pulse and hence cannot be employed for accurate dosimetry in the future clinical transition of FLASH radiotherapy. This implies the need to develop alternative techniques and dosimeters able to sustain the peculiar conditions of the UHDR beams. This study investigates the feasibility of using a new generation of Silicon Carbide (SiC) detectors for the measurement of the instantaneous dose rate of UHDR electron beams. An experimental investigation was conducted with the ElectronFLASH linac developed by the SIT Sordina company and able to accelerate 7 and 9 MeV electron pulsed beams at FLASH regimes. The signals
produced in the SiC detectors were acquired and compared with the signals detected by the monitoring system currently mounted along the LINAC, i.e. two AC current transformers supplied by the Bergoz company. The main purpose of the experiment was to demonstrate the capability of the developed SiC detector to measure the single pulse duration and waveform with high time resolution and accuracy. The test was performed by using both 7 and 9 MeV electron beams and has shown promising results.
Impact of beam-coupling impedance on the Schottky spectrum of bunched beam
Authors: Lannoy C. , Lasocha K. , Pieloni T. , Alves D. , Mounet N.
Published: March 2024

The Schottky monitors of the Large Hadron Collider (LHC) can
be used for non-invasive beam diagnostics to estimate various bunch
characteristics, such as tune, chromaticity, bunch profile or
synchrotron frequency distribution. However, collective effects, in
particular beam-coupling impedance, can significantly affect
Schottky spectra when large bunch charges are involved. In such
conditions, the available interpretation methods are difficult to
apply directly to the measured spectra, thus preventing the
extraction of beam and machine parameters, which is possible for
lower bunch charges. To study the impact of impedance on such
spectra, we introduce a method for building Schottky spectra from
macro-particle simulations performed with the PyHEADTAIL code,
applied to LHC beam conditions. In this case, the use of a standard
Fast Fourier Transform (FFT) algorithm to recover the spectral
content of the beam becomes computationally intractable memory-wise,
because of the relatively short bunch length compared to the large
revolution period. To circumvent this difficulty, a semi-analytical
method was developed to efficiently compute the Fourier
transform. The simulated Schottky spectrum is then compared against
theoretical formulas and measurements of Schottky signals previously
obtained with lead ion beams in the LHC where impedance effects are
expected to be limited. Furthermore, this study provides
preliminary interpretations of the impact of beam-coupling impedance
on proton Schottky spectra by incorporating longitudinal and
transverse resonator-like impedance models into the simulations. A
theoretical framework is also introduced for the case of the
longitudinal impedance, allowing the extension of the existing
theoretical formalism.
The nonlinear Schrödinger equation in cylindrical geometries
Authors: Krechetnikov R
Published: March 2024

The nonlinear Schrödinger equation was originally derived in nonlinear optics as a model for beam propagation, which naturally requires its application in cylindrical coordinates. However, that derivation was performed in Cartesian coordinates for linearly polarized fields with the Laplacian

Δ

⊥

=

∂

x

2

+

∂

y

2

transverse to the beam z-direction, and then, tacitly assuming covariance, extended to axisymmetric cylindrical setting. As we show, first with a simple example and next with a systematic derivation in cylindrical coordinates for axisymmetric and hence radially polarized fields,

Δ

⊥

=

∂

r

2

+

1
r

∂

r

must be amended with a potential

V
(
r
)
=

1

r

2

, which leads to a Gross–Pitaevskii equation instead. Hence, results for beam dynamics and collapse must be revisited in this setting.
Improving performance of quantum heat engines using modified Otto cycle
Authors: S Revathy B , Sharma Harsh , Divakaran Uma
Published: March 2024

The efficiency of a quantum heat engine is maximum when the unitary strokes of the quantum Otto cycle are adiabatic. On the other hand, this may not be always possible due to small energy gaps in the system, especially at the critical point (CP) where the gap between the ground state and the first excited state vanishes and the system gets excited. With the aim to regain this lost adiabaticity, we modify one of the unitary strokes of the Otto cycle by allowing the system to first evolve with a time dependent Hamiltonian as in the case of a usual Otto cycle, followed by an additional evolution with a different time independent Hamiltonian so that the system reaches a less excited state. This will help in increasing the magnitude of the heat absorbed from the hot bath so that the work output and efficiency of the engine can be increased. We demonstrate this method using an integrable model and a non-integrable model as the working medium and discuss the generality and limitations of this method. In the case of a two spin system, the optimal value for the time till which the system needs to be freely evolved is calculated analytically in the adiabatic limit. The results show that implementing this modified unitary stroke significantly improves the work output and efficiency of the engine, especially when it crosses the CP.
Breast masses with rim enhancement on contrast-enhanced mammography: morphological and enhancement features for diagnosis and differentiation of benign and malignant
Authors: Wen Chanjuan , Wang Sina , Ma Mengwei , Xu Zeyuan , Zeng Fengxia , Zeng Hui , Liao Xin , He Zilong , Xu Weimin , Chen Weiguo
Published: March 2024

Objectives

To investigate the imaging characteristics and clinicopathological features of rim enhancement of breast masses demonstrated on contrast-enhanced mammography (CEM).

Methods

67 cases of breast lesions confirmed by pathology and showing rim enhancement on CEM examinations were analyzed. The lesions were divided into benign and malignant groups, and the morphological and enhanced features were described. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated separately for each morphology descriptor to evaluate the diagnostic ability of each indicator.

Results

There were 35 (52.2%) malignant and 32 (47.8%) benign lesions. There are significant differences in the morphological and enhanced features between benign and malignant lesions. 29/35 (82.9%) malignant lesions exhibited irregular shapes, and 31/35 (88.6%) showed indistinct margins. 28/35 (80%) malignant lesions displayed strong enhancement on CEM, while 12/32 (37.5%) benign lesions exhibited weak enhancement (P = 0.001). Malignant lesions showed a higher incidence of unsmooth inner walls than benign lesions (28/35 vs 7/32; P <.001). Lesion margins showed high sensitivity of 88.57% and NPV of 81.8%. The presence of suspicious calcifications had the highest specificity of 100% and PPV of 100%. The diagnostic sensitivity, specificity, PPV, and NPV of the combined parameters were 97.14%, 93.15%, 94.44%, and 96.77%, respectively.

Conclusions

The assessment of morphological and enhanced features of breast lesions exhibiting rim enhancement on CEM can improve the differentiation between benign and malignant breast lesions.

Advances in knowledge

This article provides a reference for the differential diagnosis of ring enhanced lesions on CEM.
Migration and making of non-heteronormative households and families: lived experiences of cisgender women partners of trans men in Bengaluru
Authors: Puthan Purayil Agaja
Published: March 2024

The lived experiences of cisgender women partners of trans men are rarely a subject of concern, even for sexuality studies in India. This article looks into the lived experiences of cisgender-identified female partners of trans men who migrated to Bengaluru city from different parts of south India to live with their trans men partners. Despite constant opposition and threats from their natal families, these women decided to relocate to Bengaluru along with their trans men partners. Bengaluru-based Non-Governmental Organizations (NGOs) working on gender and sexual minorities helped them migrate and settle in Bengaluru. The queer and trans community in Bengaluru also helped them deal with the challenges post-migration. Post-migration, these women formed households and families along with their trans men partners. This study uses Pfeffer’s conceptualization of ‘normative resistance’ and ‘inventive pragmatism’ to elucidate how, post- migration, the women and their trans men partners strategically resisted and accessed social structure/institutions to receive social recognition and escape public stigma and violence. The study also shows that inegalitarian emotional and household division of labour exists between the women and their trans men partners. Even as the women try to naturalize them, they were not passive receptors and have learned to strategize their roles in the household realm. Simultaneously, the article also shows that the space created by the NGOs and trans-civic networks in the city has helped these women form a strong community consciousness and forge support system that gives them the confidence to live with their trans men partners.
Human cytomegalovirus seropositivity and its influence on oral rotavirus vaccine immunogenicity: a specific concern for HIV-exposed-uninfected infants
Authors: Laban Natasha , Bosomprah Samuel , Chilengi Roma , Simuyandi Michelo , Chisenga Caroline , Ng’ombe Harriet , Musukuma-Chifulo Kalo , Goodier Martin
Published: March 2024

Oral rotavirus vaccines demonstrate diminished immunogenicity in low-income settings where human cytomegalovirus infection is acquired early in childhood and modulates immunity. We hypothesized that human cytomegalovirus infection around the time of vaccination may influence immunogenicity. We measured plasma human cytomegalovirus-specific immunoglobulin M antibodies in rotavirus vaccinated infants from 6 weeks to 12 months old and compared rotavirus immunoglobulin A antibody titers between human cytomegalovirus seropositive and seronegative infants. There was no evidence of an association between human cytomegalovirus serostatus at 9 months and rotavirus-specific antibody titers at 12 months (geometric mean ratio 1.01, 95% CI: 0.70, 1.45; P = 0.976) or fold-increase in RV-IgA titer between 9 and 12 months (risk ratio 0.999, 95%CI: 0.66, 1.52; P = 0.995) overall. However, HIV-exposed-uninfected infants who were seropositive for human cytomegalovirus at 9 months old had a 63% reduction in rotavirus antibody geometric mean titers at 12 months compared to HIV-exposed-uninfected infants who were seronegative for human cytomegalovirus (geometric mean ratio 0.37, 95% CI: 0.17, 0.77; P = 0.008). While the broader implications of human cytomegalovirus infections on oral rotavirus vaccine response might be limited in the general infant population, the potential impact in the HIV-exposed-uninfected infants cannot be overlooked. This study highlights the complexity of immunological responses and the need for targeted interventions to ensure oral rotavirus vaccine efficacy, especially in vulnerable subpopulations.
Non-image-forming vision as measured through ipRGC-mediated pupil constriction is not modulated by covert visual attention
Authors: Vilotijević Ana , Mathôt Sebastiaan
Published: March 2024

In brightness, the pupil constricts, while in darkness, the pupil dilates; this is known as the pupillary light response (PLR). The PLR is driven by all photoreceptors: rods and cones, which contribute to image-forming vision, and intrinsically photosensitive retinal ganglion cells (ipRGCs), which mainly contribute to non-image-forming vision. Rods and cones cause immediate pupil constriction upon light exposure, whereas ipRGCs cause sustained constriction throughout light exposure. Recent studies have shown that covert attention modulated the initial PLR; however, it remains unclear whether the same holds for the sustained PLR. We tested this by leveraging ipRGCs’ responsiveness to blue light, causing the most prominent sustained constriction. While replicating previous studies by showing that pupils constricted more when either directly looking at, or covertly attending to, bright as compared to dim stimuli (with the same color), we also found that the pupil constricted more when directly looking at blue as compared to red stimuli (with the same luminosity). Crucially, however, in two high-powered studies (n = 60), we did not find any pupil-size difference when covertly attending to blue as compared to red stimuli. This suggests that ipRGC-mediated pupil constriction, and possibly non-image-forming vision more generally, is not modulated by covert attention.
Concurrent abnormal non-acid reflux is associated with additional chronic rejection risk in lung transplant patients with increased acid exposure
Authors: Lo Wai-Kit , Muftah Mayssan , Goldberg Hilary J , Sharma Nirmal , Chan Walter W
Published: March 2024

Acid reflux has been associated with allograft injury and rejection in lung transplant patients; however, the pathogenic role of non-acid reflux remains debated. We aimed to evaluate the impact of concurrent abnormal non-acid reflux with acid reflux on chronic rejection in lung transplant patients with acid reflux. This was a retrospective cohort study of lung transplant recipients who underwent pre-transplant combined impedance–pH study off acid suppression. Only subjects with acid exposure >4% were included. Non-acid reflux (pH > 4) episodes >27 was considered abnormal per prior normative studies. Chronic rejection was defined as chronic lung allograft dysfunction (CLAD) per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses were performed using Cox proportional hazards and Kaplan–Maier methods, with censoring at death, anti-reflux surgery, or last follow-up. In total, 68 subjects (28 abnormal/40 normal non-acid reflux) met inclusion criteria for the study. Baseline demographic/clinical characteristics were similar between groups. Among this cohort of patients with increased acid exposure, subjects with concurrent abnormal non-acid reflux had significantly higher risk of CLAD than those without on Kaplan–Meier analysis (log-ranked P = 0.0269). On Cox multivariable regression analysis controlling for body mass index, age at transplantation, and proton pump inhibitor use, concurrent abnormal non-acid reflux remained independently predictive of increased CLAD risk (hazard ratio 2.31, confidence interval: 1.03–5.19, P = 0.04). Presence of concurrent abnormal non-acid reflux in lung transplant subjects with increased acid exposure is associated with additional risk of chronic rejection. Non-acid reflux may also contribute to pathogenicity in lung allograft injury/rejection, supporting a potential role for impedance-based testing in this population.
Fecal microbiota related to postoperative endoscopic recurrence in patients with Crohn's disease
Authors: Wang Haichao , Yan Guorong , Wu Yaling , Zhuoma Deji , Liu Zhanju , Gao Xuefeng , Wang Xiaolei
Published: March 2024

Background

Postoperative recurrence (POR) remains a major challenge for patients with Crohn’s disease (CD). Gut microbial dysbiosis has been reported to be involved in the pathogenesis of POR. This study aims to investigate the relationship between fecal microbiome and endoscopic recurrence in patients with CD after ileocolonic resection.

Methods

This is a cross-sectional study. Fecal samples were collected from 52 patients with CD after surgical intervention from 6 to 12 months before endoscopic examination. Endoscopic recurrence was defined as Rutgeerts score ≥ i2. The microbiome was analyzed by sequencing the V3–V4 hypervariable regions of the 16S rRNA gene.

Results

A total of 52 patients were included and classified into POR (n = 27) and non-POR (n = 25) groups. Compared with the non-POR group, the POR group had a significantly lower community richness (Chao1 index: 106.5 vs 124, P = 0.013) and separated microbial community (P = 0.007 for Adonis, P = 0.032 for Anosim), combined with different distribution of 16 gut microbiotas and decrease of 11 predicted metabolic pathways (P < 0.05). Lactobacillus and Streptococcus were identified to closely correlate to non-POR (P < 0.05) after controlling for confounding factors. Kaplan-Meier analysis indicated that the patients with higher abundance of Streptococcus experienced longer remission periods (P < 0.01), but this was not for Lactobacillus. The predicted ethylmalonyl-coA pathway related to increased amount of succinate was positively correlated with Streptococcus (r > 0.5, P < 0.05).

Conclusions

The characteristic alterations of fecal microbiota are associated with postoperative endoscopic recurrence in patients with CD; particularly, high abundance of Streptococcus may be closely related to endoscopic remission.
DiffGR: Detecting Differentially Interacting Genomic Regions from Hi-C Contact Maps
Authors: Liu Huiling , Ma Wenxiu
Published: March 2024

Recent advances in high-throughput chromosome conformation capture (Hi-C) techniques have allowed us to map genome-wide chromatin interactions and uncover higher-order chromatin structures, thereby shedding light on the principles of genome architecture and functions. However, statistical methods for detecting changes in large-scale chromatin organization such as topologically associating domains (TADs) are still lacking. Here, we proposed a new statistical method, DiffGR, for detecting differentially interacting genomic regions at the TAD level between Hi-C contact maps. We utilized the stratum-adjusted correlation coefficient to measure similarity of local TAD regions. We then developed a nonparametric approach to identify statistically significant changes of genomic interacting regions. Through simulation studies, we demonstrated that DiffGR can robustly and effectively discover differential genomic regions under various conditions. Furthermore, we successfully revealed cell type-specific changes in genomic interacting regions in both human and mouse Hi-C datasets, and illustrated that DiffGR yielded consistent and advantageous results compared with state-of-the-art differential TAD detection methods. The DiffGR R package is published under the GNU General Public License (GPL) ≥ 2 license and is publicly available at https://github.com/wmalab/DiffGR.
Inter- and Intraobserver Variability on Endoscopic Scoring Systems in Crohn’s Disease and Ulcerative Colitis: A Systematic Review and Meta-Analysis
Authors: Hashash Jana G , Yu Ci Ng Faye , Farraye Francis A , Wang Yeli , Colucci Daniel R , Baxi Shrujal , Muneer Sadaf , Reddan Mitchell , Shingru Pratik , Melmed Gil Y
Published: March 2024

Background

Endoscopy scoring is a key component in the diagnosis of ulcerative colitis (UC) and Crohn’s disease (CD). Variability in endoscopic scoring can impact patient trial eligibility and treatment effect measurement. In this study, we examine inter- and intraobserver variability of inflammatory bowel disease endoscopic scoring systems in a systematic review and meta-analysis.

Methods

We included observational studies that evaluated the inter- and intraobserver variability using UC (endoscopic Mayo Score [eMS], Ulcerative Colitis Endoscopic Index of Severity [UCEIS]) or CD (Crohn’s Disease Endoscopic Index of Severity [CDEIS], Simple Endoscopic Score for Crohn’s Disease [SES-CD]) systems among adults (≥18 years of age) and were published in English. The strength of agreement was categorized as fair, moderate, good, and very good.

Results

A total of 6003 records were identified. After screening, 13 studies were included in our analysis. The overall interobserver agreement rates were 0.58 for eMS, 0.66 for UCEIS, 0.80 for CDEIS, and 0.78 for SES-CD. The overall heterogeneity (I2) for these systems ranged from 93.2% to 99.2%. A few studies assessed the intraobserver agreement rate. The overall effect sizes were 0.75 for eMS, 0.87 for UCEIS, 0.89 for CDEIS, and 0.91 for SES-CD.

Conclusions

The interobserver agreement rates for eMS, UCEIS, CDEIS, and SES-CD ranged from moderate to good. The intraobserver agreement rates for eMS, UCEIS, CDEIS, and SES-CD ranged from good to very good. Solutions to improve interobserver agreement could allow for more accurate patient assessment, leading to richer, more accurate clinical management and clinical trial data.
Rediversion of the Failing Ileoanal Pouch: First Step in Pouch Salvage?
Authors: Uchino Tairin , Lincango Eddy P , Hernandez Dominguez Oscar , Bhama Anuradha , Gorgun Emre , Kanters Arielle , Kessler Hermann , Lipman Jeremy , Liska David , Sommovilla Joshua , Valente Michael , Steele Scott R , Hull Tracy , Holubar Stefan D
Published: March 2024

Background

Ileal pouch–anal anastomosis is a technically demanding procedure with many potential complications. Rediversion with an ileostomy is often the first step in pouch salvage; however, it may not be clear if an individual patient will undergo subsequent pouch salvage surgery. We aimed to describe the indications and short- and long-term outcomes of rediversion in our pouch registry.

Methods

We queried our institutional pouch registry for patients who underwent index 2- or 3-stage IPAA and subsequent rediversion at our institution between 1985 and 2022. Pouches constructed elsewhere, rediverted elsewhere, or those patients who underwent pouch salvage/excision without prior rediversion were excluded. Patients were selected for pouch salvage according to the surgeon’s discretion.

Results

Overall, 177 patients (3.4% of 5207 index pouches) were rediverted. At index pouch, median patient age was 32 years and 50.8% were women. Diagnoses included ulcerative colitis (86.4%), indeterminate colitis (6.2%), familial adenomatous polyposis (4.0%), and others (3.4%). Median time from prior ileostomy closure to rediversion was 7.2 years. Indications for rediversion were inflammatory in 98 (55.4%) and noninflammatory in 79 (44.6%) patients. After rediversion, 52% underwent pouch salvage, 30% had no further surgery, and 18.1% underwent pouch excision. The 5-year pouch survival rates for inflammatory and noninflammatory indications were 71.5% and 94.5%, respectively (P = .02).

Conclusion

Rediversion of ileoanal pouches is a safe initial strategy to manage failing pouches and is a useful first step in pouch salvage in many patients. Subsequent salvage surgery for noninflammatory indications had a significantly higher pouch salvage rate than those rediverted for inflammatory complications.
Hypervirulent Klebsiella pneumoniae employs genomic island encoded toxins against bacterial competitors in the gut
Authors: Tan Yi Han , Arros Patricio , Berríos-Pastén Camilo , Wijaya Indrik , Chu Wilson H W , Chen Yahua , Cheam Guoxiang , Mohamed Naim Ahmad Nazri , Marcoleta Andrés E , Ravikrishnan Aarthi , Nagarajan Niranjan , Lagos Rosalba , Gan Yunn-Hwen
Published: March 2024

The hypervirulent lineages of Klebsiella pneumoniae (HvKp) cause invasive infections such as Klebsiella-liver abscess. Invasive infection often occurs after initial colonization of the host gastrointestinal tract by HvKp. Over 80% of HvKp isolates belong to the clonal group 23 sublineage I that has acquired genomic islands (GIs) GIE492 and ICEKp10. Our analysis of 12 361 K. pneumoniae genomes revealed that GIs GIE492 and ICEKp10 are co-associated with the CG23-I and CG10118 HvKp lineages. GIE492 and ICEKp10 enable HvKp to make a functional bacteriocin microcin E492 (mccE492) and the genotoxin colibactin, respectively. We discovered that GIE492 and ICEKp10 play cooperative roles and enhance gastrointestinal colonization by HvKp. Colibactin is the primary driver of this effect, modifying gut microbiome diversity. Our in vitro assays demonstrate that colibactin and mccE492 kill or inhibit a range of Gram-negative Klebsiella species and Escherichia coli strains, including Gram-positive bacteria, sometimes cooperatively. Moreover, mccE492 and colibactin kill human anaerobic gut commensals that are similar to the taxa found altered by colibactin in the mouse intestines. Our findings suggest that GIs GIE492 and ICEKp10 enable HvKp to kill several commensal bacterial taxa during interspecies interactions in the gut. Thus, acquisition of GIE492 and ICEKp10 could enable better carriage in host populations and explain the dominance of the CG23-I HvKp lineage.
The impact of indole and mucin on sporulation, biofilm formation, and enterotoxin production in foodborne Clostridium perfringens
Authors: Wang Chao , Defoirdt Tom , Rajkovic Andreja
Published: March 2024

Aims

Indole and mucin are compounds found in the host environment as they are produced by the host or by the host-associated microbiota. This study investigated whether indole and mucin impact Clostridium perfringens growth and sporulation, as well as enterotoxin production and biofilm formation.

Methods and results

There was no impact on growth of Cl. perfringens for up to 400 µM indole and 240 mg/l mucin, and neither indole nor mucin affected sporulation. Reverse-transcriptase qPCR showed that mucin strongly upregulated the expression of Cl. perfringens enterotoxin (up to 121-fold increase), whereas indole had a much more modest effect (2-fold). This was also reflected in increased Cl. perfringens enterotoxin levels in mucin-treated Cl. perfringens (as assessed by a reversed passive latex agglutination assay). Finally, mucin and indole significantly increased biofilm formation of Cl. perfringens, although the effect size was relatively small (less than 1.5 fold).

Conclusion

These results indicate that Cl. perfringens can sense its presence in a host environment by responding to mucin, and thereby markedly increased enterotoxin production.
Development of Green and High-Throughput Microwell Spectrophotometric Methods for Determination of Galidesivir in Bulk Drug and Dosage Forms Based on Simple Oxidimetric Reactions With Inorganic Agents
Authors: Darwish Ibrahim A , Alzoman Nourah Z , Abuhejail Reem M
Published: March 2024

Background

Galidesivir hydrochloride (GDV) is a new potent and safe antiviral drug used for the treatment of a broad spectrum of viral diseases, including COVID-19. In the literature, no analytical method exists for the determination of GDV in bulk or dosage form.

Objective

The objective of this study was the investigation of oxidation reactions of GDV with five inorganic oxidizing reagents and the employment of the reactions in the development of five green microwell spectrophotometric methods (MW-SPMs) with simple procedure and high throughputs for determination of GDV in its bulk and dosage forms (capsules).

Methods

The reactions were carried out in 96-well plates, and the absorbances of reaction solutions were measured by an absorbance microplate reader. Variables influencing the reactions were carefully investigated and optimized.

Results

Under the refined optimum conditions, Beer’s law with excellent correlation coefficients (0.9992–0.9997) was followed in GDV concentrations in a general range of 5–700 µg/mL, and the limits of detection were ≥1.8 µg/mL. All validation parameters of all methods were acceptable. The methods were successfully applied to the analysis of GDV in bulk drug and capsules with high accuracy and precision; the recovery percentages were 98.6–101.2 ± 0.58–1.14%. The greenness of MW-SPMs was evaluated by three comprehensive metric tools, which demonstrated the adherence of MW-SPMs to the principles of the green analytical chemistry (GAC) approach.

Conclusions

The proposed MW-SPMs combined the advantages of microwell-based practice and the use of common laboratory reagents for the analysis. The advantages of microwell analysis were the high throughput, readily available for semi-automation, reduced samples/reagents volume, precise measurements, and versatility. The advantages of using common laboratory reagents were the availability, consistency, compatibility, safety, and cost-effectiveness.

Highlights

Overall, the proposed MW-SPMs are versatile, valuable tools for the quantitation of GDV during its pharmaceutical manufacturing.
Genomic regions and biological pathways associated with sex-limited reproductive traits in bovine species
Authors: Olasege Babatunde S , Oh Zhen Yin , Tahir Muhammad S , Porto-Neto Laercio R , Hayes Ben J , Fortes Marina R S
Published: March 2024

Many animal species exhibit sex-limited traits, where certain phenotypes are exclusively expressed in one sex. Yet, the genomic regions that contribute to these sex-limited traits in males and females remain a subject of debate. Reproductive traits are ideal phenotypes to study sexual differences since they are mostly expressed in a sex-limited way. Therefore, this study aims to use local correlation analyses to identify genomic regions and biological pathways significantly associated with male and female sex-limited traits in two distinct cattle breeds (Brahman [BB] and Tropical Composite [TC]). We used the Correlation Scan method to perform local correlation analysis on 42 trait pairs consisting of six female and seven male reproductive traits recorded on ~1,000 animals for each sex in each breed. To pinpoint a specific region associated with these sex-limited reproductive traits, we investigated the genomic region(s) consistently identified as significant across the 42 trait pairs in each breed. The genes found in the identified regions were subjected to Quantitative Trait Loci (QTL) colocalization, QTL enrichment analyses, and functional analyses to gain biological insight into sexual differences. We found that the genomic regions associated with the sex-limited reproductive phenotypes are widely distributed across all the chromosomes. However, no single region across the genome was associated with all the 42 reproductive trait pairs in the two breeds. Nevertheless, we found a region on the X-chromosome to be most significant for 80% to 90% (BB: 33 and TC: 38) of the total 42 trait pairs. A considerable number of the genes in this region were regulatory genes. By considering only genomic regions that were significant for at least 50% of the 42 trait pairs, we observed more regions spread across the autosomes and the X-chromosome. All genomic regions identified were highly enriched for trait-specific QTL linked to sex-limited traits (percentage of normal sperm, metabolic weight, average daily gain, carcass weight, age at puberty, etc.). The gene list created from these identified regions was enriched for biological pathways that contribute to the observed differences between sexes. Our results demonstrate that genomic regions associated with male and female sex-limited reproductive traits are distributed across the genome. Yet, chromosome X seems to exert a relatively larger effect on the phenotypic variation observed between the sexes.