Consistent Response Research Articles

Rasch Analysis Of The Dermatology Life Quality Index.

Previous results of the Dermatology-Life-Quality-Index (DLQI) validation in Colombia based on the classical test theory (CTT) perspective have showed the need to delve into its measurement properties. Therefore, we aimed to assess the structural validity, internal consistency and item response analysis of the DLQI through the item response theory (IRT) or the Rasch model. We assessed the dimensionality of the DLQI, determined its difficulty, discrimination and differential functioning and went on to evaluate its internal consistency and discriminative validity among patients with inflammatory and non-inflammatory skin disease. We recruited Colombian patients with different skin diseases. Data of 865 patients (mean age, 49.3 years; 61% females) were included. DLQI-scores ranged from 0 up to 30. Internal consistency for dichotomous item #7 showed a McDonald's Omega coefficient of 0.85 (95%CI, 0.84-0.87) and a Cronbach's α coefficient of 0.86 (95%CI, 0.84-0.88). For ordinal item #7, the McDonald's Omega coefficient was 0.87 (95%IC:0.85-0.89) and Cronbach's α coefficient, 0.84 (95%CI, 0.82-0.87). Horn's parallel analysis revealed the presence of DLQI unidimensionality with a 1-factor solution. Only item #1 fitted the PCM model. The remaining items, including item #9, did not show adequate fit due to overlapping responses and order changes. The validity of DLQI-COL based on Rasch analysis proved not to be a suitable instrument to evaluate QoL in our dermatologic population. A refined version of the scale with an adequate cross-cultural adaptation and validation process is needed to obtain an appropriate and reliable version of the instrument for QOL measuring in Colombian patients with skin diseases.

Study on dosimetric characteristics of polycarbonate films irradiated by electron beam

In this study, the dosimetric characteristics (thickness applicability, dose linear response, signal fading characteristic, in-batch consistency, readout reproducibility, humidity dependence, and electron energy response) of engineering polycarbonate films irradiated by electron beam were studied using spectrophotometry. The results show that polycarbonate films of various thicknesses exhibit good dose linearity within their corresponding wavelength ranges. Specifically, the dose capture range of 0.3 mm polycarbonate film spans from 950 Gy to 1000 kGy. After irradiation, the net absorbance of polycarbonate films showed an exponential decline, which was dose-dependent. The average absolute deviation of net absorbance for polycarbonate films produced within the same batch is 1.49% at 100 kGy. After 15 repeated absorbance measurements, the coefficient of variation in net absorbance for the polycarbonate films is less than 1%. Additionally, the radiation response of the polycarbonate film is affected by the environment relative humidity (during irradiation and post-irradiation storage). At the same dose of 3.5-20 MeV electron beam irradiation, the net absorbance response deviation of polycarbonate films remains below 2.26%. These results provide a comprehensive reference for detecting high doses of electron beams using engineering polycarbonate films.

Functional parcellation of the cingulate gyrus by electrical cortical stimulation: a synthetic literature review and future directions

BackgroundThe cingulate gyrus (CG), a brain structure above the corpus callosum, is recognised as part of the limbic system and plays numerous vital roles. However, its full functional capacity is...

Electroacupuncture improves vascular cognitive impairment no dementia: A Randomized Clinical Trial

BackgroundElectroacupuncture (EA) could represent a clinically effective treatment strategy for patients with vascular cognitive impairment no dementia (VCIND). This randomized trial aims to explore the underlying mechanism of EA in VCIND patients through cognitive function assessment and neuroimaging assessment. Methods140 eligible patients with VCIND were recruited and randomly divided into EA group (n = 70) and Control group (n = 70). The Montreal Cognitive Assessment (MoCA), and the Auditory Verbal Learning Test (AVLT), the Stroop color-naming task (STROOP), and the resting-state functional magnetic resonance imaging assessment. The EA group received treatment for 30 min/day, 5 times/week, for 8 weeks. ResultsEA intervention could increase the MoCA score and improve the neutral and consistency response of the STROOP test in VCIND patients (P < 0.05). fMRI functional connectivity analysis showed that, after EA, the default mode network (DMN) function of the posterior cingulate gyrus, left middle frontal gyrus, left anterior cingulate gyrus, left and right superior temporal gyrus, right insula, left precentral gyrus and other brain regions were significantly higher than that in the control group. The functional connectivity between the posterior cingulate gyrus-left middle frontal gyrus and the posterior cingulate gyrus-right superior temporal gyrus was positively correlated with cognitive function (P < 0.05). Gray Matter Volume increased in VCIND after EA(P < 0.05). ConclusionsEA can increase the functional connectivity between posterior cingulate gyrus-other gyri in VCIND patients. The functional connectivity is positively correlated with cognitive function.

An Improved Voltage Control Method for EAST Fast Control Power Supply

The Experimental Advanced Superconducting Tokamak (EAST) fast control power supply (FCPS) is an important device for controlling the vertical displacement of plasma during the nuclear fusion power generation process, adopting a multiple H-bridge invertor branch parallel operation structure to output total current. At the beginning of each shot of plasma discharge, FCPS works in open-loop voltage control mode (VCM) or closed-loop current control mode (CCM) determined by the plasma control system to output current for exciting the load coil, to achieve plasma vertical displacement control. VCM has the characteristics of fast dynamic response speed but poor consistency of branch current and insufficient branch current control accuracy and stability because of open-loop control. CCM has the characteristics of high branch current control accuracy but poor dynamic response and robustness because of control delay and control parameters determined based on engineering experience. To achieve fast and robust control, an improved voltage control method (IVCM) is proposed by combining the advantages of VCM and CCM. In the beginning of establishing the output current, FCPS operates in VCM, and rapid establishment of the output current is ensured. After the output current rapidly increases to the critical value, closed-loop current control is added to VCM to ensure the accuracy of output current control. In closed-loop current control, linear super-twisting sliding mode control is designed to achieve fast and robust control, ensuring good consistency and fast dynamic response performance of each branch current. Simulations and experiments verify that the designed IVCM has better compatibility characteristics in output current stability, control accuracy, and consistency of each branch current compared to VCM.

Effects of pain on cortical homeostatic plasticity in humans: a systematic review.

Homeostatic plasticity (HP) is a negative feedback mechanism that prevents excessive facilitation or depression of cortical excitability (CE). Cortical HP responses in humans have been investigated by using 2 blocks of noninvasive brain stimulation with a no-stimulation block in between. A healthy HP response is characterized by reduced CE after 2 excitatory stimulation blocks and increased CE when using inhibitory stimulation. Conversely, impaired HP responses have been demonstrated in experimental and chronic pain conditions. Therefore, this systematic review aimed to provide an overview of the effect of pain on cortical HP in humans. Scopus, Embase, and PubMed were searched from inception until November 20, 2023. The included studies (1) compared experimental or clinical pain conditions with healthy controls, (2) induced HP using 2 blocks of stimulation with a no-stimulation interval, and (3) evaluated CE measures such as motor-evoked potentials. Four studies were included, consisting of 5 experiments and 146 participants, of whom 63 were patients with chronic pain and 48 were subjected to an experimental pain model. This systematic review found support for an HP impairment in pain compared with that in pain-free states, reflected by a lack of CE reduction after excitatory-excitatory HP induction over the primary motor cortex. Inhibitory-inhibitory HP induction did not produce a consistent HP response across studies, independent of pain or pain-free states. Standardization of HP induction protocols and outcome calculations is needed to ensure reproducibility and study comparison. Future HP studies may consider investigating sensory domains including nociception, which would further our understanding of abnormal HP regulation in pain conditions.

(268) Intracavernous Prostaglandin Injection as a Predictor and Effectiveness Measure for LISWT Sessions in ED Patients: A Single Urologist's Experience

Abstract Introduction In recent years, therapeutic approaches for treating vasculogenic Erectile Dysfunction (ED) have evolved, with Low Intensity Shock Wave Therapy (LISWT) emerging as a promising modality. Objective To objectively evaluate the efficacy of LISWT for ED patients and to predict the required number of sessions, we examined the effects of administering up to 10 mcg of intracavernous alprostadil injections both before and after treatment Methods 85 vasculogenic ED patients (Average age: 57); 33 with mild to moderate ED and 52 with moderate or severe ED. Intracavernous injection (ICI) of ≤10 mcg of alprostadil was given before LISWT and one month post-treatment. Depending on ICI response, patients underwent either six (Erection Hardness Score (EHS) ≤3) or four (EHS=4) weekly LISWT sessions using PiezoWave2 from Richard WOLF. LISWT Parameters: 0.16mj/mm2 energy flux density, 8 Hz frequency, 10mm wave focus penetration depth, and 6000 shocks per session distributed among the two crura of the penis (2000 shocks), dorsum penis (2000 shocks), and lateral penis (2000 shocks). Results 33 patients showed a robust response to the 10mcg ICI and were treated with four LISWT sessions. 52 patients exhibited a partial response to the 10mcg ICI, necessitating six LISWT sessions. 78.6% (26 out of 33) of the patients who initially responded well to 10 mcg ICI had a consistent response to 8 mcg ICI; 63.6% (33 out of 52) of those with a partial initial response to 10 mcg ICI demonstrated an improved reaction to the same dosage post-treatment (table 1) (fig. 1). No complications were reported from the ICI. Conclusions Intracavernous prostaglandin injection can serve as a predictor for the required number of LISWT sessions and can objectively gauge the treatment's effectiveness in ED patients. Further randomized studies, incorporating parameters such as EHS, IIEF, and the ICI dosage, are recommended to validate this method's feasibility Disclosure No.

Predictive Power of Random Forests in Analyzing Risk Management in Islamic Banking

This study utilizes the random forest technique to investigate risk management practices and concerns in Islamic banks using survey data from 2016 to 2021. Findings reveal that larger banks provide more consistent survey responses, driven by their confidence and larger survey budgets. Moreover, a positive link is established between a country’s development, characterized by high GDPs and low inflation and interest rates, and the precision of Islamic banks’ survey responses. Analyzing risk-related concerns, the study notes a significant reduction in credit portfolio risk attributed to improved risk management practices, global economic growth, stricter regulations, and diversified asset portfolios. Concerns related to terrorism financing and cybersecurity risks have also decreased due to the better enforcement of anti-money laundering regulations and investments in cybersecurity infrastructure and education. This research enhances our understanding of risk management in Islamic banks, highlighting the impact of bank size and country development. Additionally, it emphasizes the need for ongoing analysis beyond 2021 to account for potential COVID-19 effects and evolving risk management and regulatory practices in Islamic banking.

North Atlantic Response to Observed North Atlantic Oscillation Surface Heat Flux in Three Climate Models

Abstract We investigate how the ocean responds to 10-yr persistent surface heat flux forcing over the subpolar North Atlantic (SPNA) associated with the observed winter NAO in three CMIP6-class coupled models. The experiments reveal a broadly consistent ocean response to the imposed NAO forcing. Positive NAO forcing produces anomalously dense water masses in the SPNA, increasing the southward lower (denser) limb of the Atlantic meridional overturning circulation (AMOC) in density coordinates. The southward propagation of the anomalous dense water generates a zonal pressure gradient overlying the models’ North Atlantic Current that enhances the upper (lighter) limb of the density-space AMOC, increasing the heat and salt transport into the SPNA. However, the amplitude of the thermohaline process response differs substantially between the models. Intriguingly, the anomalous dense-water formation is not primarily driven directly by the imposed flux anomalies, but rather dominated by changes in isopycnal outcropping area and associated changes in surface water mass transformation (WMT) due to the background surface heat fluxes. The forcing initially alters the outcropping area in dense-water formation regions, but WMT due to the background surface heat fluxes through anomalous outcropping area decisively controls the total dense-water formation response and can explain the intermodel amplitude difference. Our study suggests that coupled models can simulate consistent mechanisms and spatial patterns of decadal SPNA variability when forced with the same anomalous buoyancy fluxes, but the amplitude of the response depends on the background states of the models.

Assessment of Drought Responses of Wild Soybean Accessions at Different Growth Stages

Drought is a significant abiotic stress that limits crop production. Soybeans [Glycine max (L.) Merr.] are regarded as drought-sensitive. In the present study, the drought responses of wild soybean accessions were evaluated at different growth stages. Based on the leaf wilting index of 411 accessions at the vegetative stage, seven highly tolerant (HT) and 24 tolerant (T) accessions were identified, although most wild soybeans were classified as moderate (M), sensitive (S), and highly sensitive (HS) genotypes. In addition, with selected wild soybeans, stomatal density decreased in HT accessions but increased in HS accessions under drought conditions at the vegetative stage. However, for cultivated soybeans, the stomatal density of the drought-tolerant and drought-sensitive were not significantly different between the two conditions. The expression levels of drought-related transcriptional factors indicated that the HT genotype showed a higher expression level of drought-related genes than that of the HS genotype at the vegetative stage. At the reproductive stages, 12 wild soybeans randomly selected from HT, T, S, and HS based on assessment at the vegetative stage showed consistent drought responses with seed yield, root development, and water status. However, the extent of the detrimental effect of drought on the germination rates and root length of 165 wild soybeans at the germination stage varied depending on the genotype, indicating that there may not be a robust correlation between phenotypic measurements at the germination stage and drought-related assessments at the two growth stages. The information from this study can provide useful breeding materials for the development of drought-tolerant cultivars from wild soybeans.

Oncopig bladder cancer cells recapitulate human bladder cancer treatment responses in vitro.

Bladder cancer is a common neoplasia of the urinary tract that holds the highest cost of lifelong treatment per patient, highlighting the need for a continuous search for new therapies for the disease. Current bladder cancer models are either imperfect in their ability to translate results to clinical practice (mouse models), or rare and not inducible (canine models). Swine models are an attractive alternative to model the disease due to their similarities with humans on several levels. The Oncopig Cancer Model has been shown to develop tumors that closely resemble human tumors. However, urothelial carcinoma has not yet been studied in this platform. We aimed to develop novel Oncopig bladder cancer cell line (BCCL) and investigate whether these urothelial swine cells mimic human bladder cancer cell line (5637 and T24) treatment-responses to cisplatin, doxorubicin, and gemcitabine in vitro. Results demonstrated consistent treatment responses between Oncopig and human cells in most concentrations tested (p>0.05). Overall, Oncopig cells were more predictive of T24 than 5637 cell therapeutic responses. Microarray analysis also demonstrated similar alterations in expression of apoptotic (GADD45B and TP53INP1) and cytoskeleton-related genes (ZMYM6 and RND1) following gemcitabine exposure between 5637 (human) and Oncopig BCCL cells, indicating apoptosis may be triggered through similar signaling pathways. Molecular docking results indicated that swine and humans had similar Dg values between the chemotherapeutics and their target proteins. Taken together, these results suggest the Oncopig could be an attractive animal to model urothelial carcinoma due to similarities in in vitro therapeutic responses compared to human cells.

Sensitivity improvement of subharmonic-based pressure measurement using phospholipid-coated monodisperse microbubbles

The use of the subharmonic signal from microbubbles exposed to ultrasound is a promising safe and cost-effective approach for the non-invasive measurement of blood pressure. Achieving a high sensitivity of the subharmonic amplitude to the ambient overpressure is crucial for clinical applications. However, currently used microbubbles have a wide size distribution and diverse shell properties. This causes uncertainty in the response of the subharmonic amplitude to changes in ambient pressure, which limits the sensitivity. The aim of this study was to use monodisperse microbubbles to improve the sensitivity of subharmonic-based pressure measurements. With the same shell materials and gas core, we used a flow-focusing microfluidic chip and a mechanical agitation method to fabricate monodisperse (∼2.45-µm mean radius and 4.7 % polydisperse index) and polydisperse microbubbles (∼1.51-µm mean radius and 48.4 % polydisperse index), respectively. We varied the ultrasound parameters (i.e., the frequency, peak negative pressure (PNP) and pulse length), and found that there was an optimal excitation frequency (2.8 MHz) for achieving maximal subharmonic emission for monodisperse microbubbles, but not for polydisperse microbubbles. Three distinct regimes (occurrence, growth, and saturation) were identified in the response of the subharmonic amplitude to increasing PNP for both monodisperse and polydisperse microbubbles. For the polydisperse microbubbles, the subharmonic amplitude decreased either monotonically or non-monotonically with ambient overpressure, depending on the PNP. By contrast, for the monodisperse microbubbles, there was only a monotonic decrease at all PNPs. The maximum sensitivity (1.18 dB/kPa, R2 = 0.97) of the subharmonic amplitude to ambient overpressure for the monodisperse microbubbles was ∼6.5 times higher than that for the polydisperse microbubbles (0.18 dB/kPa, R2 = 0.88). These results show that monodisperse microbubbles can achieve a more consistent response of the subharmonic signal to changes in ambient overpressure and greatly improve the measurement sensitivity.

A screening study on the detection strain of Coxsackievirus A6: the key to evaluating neutralizing antibodies in vaccines

ABSTRACT The increasing incidence of diseases caused by Coxsackievirus A6 (CV-A6) and the presence of various mutants in the population present significant public health challenges. Given the concurrent development of multiple vaccines in China, it is challenging to objectively and accurately evaluate the level of neutralizing antibody response to different vaccines. The choice of the detection strain is a crucial factor that influences the detection of neutralizing antibodies. In this study, the National Institutes for Food and Drug Control collected a prototype strain (Gdula), one subgenotype D1, as well as 13 CV-A6 candidate vaccine strains and candidate detection strains (subgenotype D3) from various institutions and manufacturers involved in research and development. We evaluated cross-neutralization activity using plasma from naturally infected adults (n = 30) and serum from rats immunized with the aforementioned CV-A6 strains. Although there were differences between the geometric mean titer (GMT) ranges of human plasma and murine sera, the overall trends were similar. A significant effect of each strain on the neutralizing antibody test (MAX/MIN 48.0 ∼16410.3) was observed. Among all strains, neutralization of the S112 strain by 15 different sera resulted in higher neutralizing antibody titers (GMTS112 = 132.0) and more consistent responses across different genotypic immune sera (MAX/MIN = 48.0). Therefore, S112 may serve as a detection strain for NtAb testing in various vaccines, minimizing bias and making it suitable for evaluating the immunogenicity of the CV-A6 vaccine.

Machines, mathematics, and modules: the potential to provide real-time metrics for pain under anesthesia.

The brain-based assessments under anesthesia have provided the ability to evaluate pain/nociception during surgery and the potential to prevent long-term evolution of chronic pain. Prior studies have shown that the functional near-infrared spectroscopy (fNIRS)-measured changes in cortical regions such as the primary somatosensory and the polar frontal cortices show consistent response to evoked and ongoing pain in awake, sedated, and anesthetized patients. We take this basic approach and integrate it into a potential framework that could provide real-time measures of pain/nociception during the peri-surgical period. This application could have significant implications for providing analgesia during surgery, a practice that currently lacks quantitative evidence to guide patient tailored pain management. Through a simple readout of "pain" or "no pain," the proposed system could diminish or eliminate levels of intraoperative, early post-operative, and potentially, the transition to chronic post-surgical pain. The system, when validated, could also be applied to measures of analgesic efficacy in the clinic.

Extreme environments simplify reassembly of communities of arbuscular mycorrhizal fungi.

The ecological impacts of long-term (press) disturbance on mechanisms regulating the relative abundance (i.e., commonness or rarity) and temporal dynamics of species within a community remain largely unknown. This is particularly true for the functionally important arbuscular mycorrhizal (AM) fungi; obligate plant-root endosymbionts that colonize more than two-thirds of terrestrial plant species. Here, we use high-resolution amplicon sequencing to examine how AM fungal communities in a specific extreme ecosystem-mofettes or natural CO2 springs caused by geological CO2 exhalations-are affected by long-term stress. We found that in mofettes, specific and temporally stable communities form as a subset of the local metacommunity. These communities are less diverse and dominated by adapted, "stress tolerant" taxa. Those taxa are rare in control locations and more benign environments worldwide, but show a stable temporal pattern in the extreme sites, consistently dominating the communities in grassland mofettes. This pattern of lower diversity and high dominance of specific taxa has been confirmed as relatively stable over several sampling years and is independently observed across multiple geographic locations (mofettes in different countries). This study implies that the response of soil microbial community composition to long-term stress is relatively predictable, which can also reflect the community response to other anthropogenic stressors (e.g., heavy metal pollution or land use change). Moreover, as AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in community structure in response to long-term environmental change have the potential to impact terrestrial plant communities and their productivity.IMPORTANCEArbuscular mycorrhizal (AM) fungi form symbiotic relationships with more than two-thirds of plant species. In return for using plant carbon as their sole energy source, AM fungi improve plant mineral supply, water balance, and protection against pathogens. This work demonstrates the importance of long-term experiments to understand the effects of long-term environmental change and long-term disturbance on terrestrial ecosystems. We demonstrated a consistent response of the AM fungal community to a long-term stress, with lower diversity and a less variable AM fungal community over time under stress conditions compared to the surrounding controls. We have also identified, for the first time, a suite of AM fungal taxa that are consistently observed across broad geographic scales in stressed and anthropogenically heavily influenced ecosystems. This is critical because global environmental change in terrestrial ecosystems requires an integrative approach that considers both above- and below-ground changes and examines patterns over a longer geographic and temporal scale, rather than just single sampling events.

Self-powered graphene/4H-SiC nanowire array-based ultraviolet photodetectors with fast response time and low dark current for promising wireless ultraviolet communication

Self-powered ultraviolet photodetectors (UV PDs) capable of detecting UV light signals without using an external power supply have become particularly attractive because of their high sensitivity, consistent optical response, ultra-small size, low energy consumption, and long-term robustness for the future. Here we reported a self-powered UV PDs coupling of two-dimensional (2D) single-layer graphene and one-dimensional (1D) 4H-SiC nanowire arrays. The fabricated PDs can feature an ultra-high on-off ratio of 6301 at 0 V and the 2D-1D architectural exhibits a low dark current of ∼4 pA, an ultra-fast response of 4.89 ms. The high performance was associated with the formed heterojunction between the 2D graphene and 1D 4H-SiC nanowire array and the high carrier mobility of the graphene. Moreover, the 2D-1D PDs with a large switching ratio and ultra-fast response time can be beneficial to achieve efficient, real-time, and accurate information transmission under 275 nm UV light, shedding some light on the development of high-performance wireless optical communication systems.

Impact of duck astrovirus on susceptibility to infection across duck ages

An outbreak of duck astrovirus (DAstV) has occurred in duck farming regions of China, causing substantial economic setbacks in the duck industry. This investigation aimed to examine the variations in DAstV pathogenicity among ducks at different age intervals. Infections were induced in ducks at distinct age groups (1, 7, 14, 21, and 28 d) utilizing the DAstv-1-GDB-2022 strain. The results indicate increased pathogenicity of the DAstv-1-GDB-2022 strain in ducklings aged 21 to 28 d, manifesting as liver and kidney enlargement, severe bleeding, and potential fatalities. Conversely, ducklings aged 1 and 14 d displayed milder symptoms postinfection. Notably, viral shedding continued in ducks of diverse age groups even 21 d postinfection (Dpi). Moreover, DAstV replicates in various tissues, predominantly affecting the liver. Immunohistochemical tests using rabbit anti-DAstV antibodies revealed robust positive signals in both the liver and kidneys, which correlated with the clinical symptom severity observed through macroscopic and microscopic examinations. Serum biochemical assays and indirect ELISA demonstrated a consistent response to DAstV infection across different age groups, with older ducklings exhibiting increased sensitivity. In conclusion, this study successfully replicated clinical symptoms similar to those of natural DAstV infection using the DAstv-1-GDB-2022 strain. Importantly, we systematically delineated the differences in susceptibility to DAstV among ducks at various ages, laying the foundation for further research into the pathogenic mechanisms of DAstV and potential vaccine development.

Single-layer graphene based resistive humidity sensor enhanced by graphene quantum dots

Graphene is broadly applied as sensitive sensing material results from its superb features. Concurrently, as a derivative of graphene with 0D structure, graphene quantum dots (GQDs) offer more possibilities as a supportive sensing material due to its adjustable size and functional group modification. In this work, GQDs are introduced to single-layer graphene (SLG) based humidity sensor to enhance the sensing performance. Specifically, consistent resistance response to relative humidity (RH) is extended from the range of 10%–60% to 10%–90% by contrary to original SLG based sensor. Parallelly, effect of the amount of GQDs is investigated by means of multiple GQDs deposition. As the resultant higher binding efficiency between water molecules and the functional groups of GQDs, improved response rate is observed. For the case of 4-time deposition of GQDs, the response rate ( ΔR/R ) reaches ∼130% in RH range of 10%–90%. Besides, the response time and recovery time are ∼0.7 s and ∼1.1 s, respectively. The fluctuation of the resistance change of the sensor under constant humidity is less than 5% over a month which demonstrates long-term reliability.

A transcriptomic time-series reveals differing trajectories during pre-floral development in the apex and leaf in winter and spring varieties of Brassica napus

Oilseed rape (Brassica napus) is an important global oil crop, with spring and winter varieties grown commercially. To understand the transcriptomic differences between these varieties, we collected transcriptomes from apex and leaf tissue from a spring variety, Westar, and a winter variety, Tapidor, before, during, and after vernalisation treatment, until the plants flowered. Large transcriptomic differences were noted in both varieties during the vernalisation treatment because of temperature and day length changes. Transcriptomic alignment revealed that the apex transcriptome reflects developmental state, whereas the leaf transcriptome is more closely aligned to the age of the plant. Similar numbers of copies of genes were expressed in both varieties during the time series, although key flowering time genes exhibited expression pattern differences. BnaFLC copies on A2 and A10 are the best candidates for the increased vernalisation requirement of Tapidor. Other BnaFLC copies show tissue-dependent reactivation of expression post-cold, with these dynamics suggesting some copies have retained or acquired a perennial nature. BnaSOC1 genes, also related to the vernalisation pathway, have expression profiles which suggest tissue subfunctionalisation. This understanding may help to breed varieties with more consistent or robust vernalisation responses, of special importance due to the milder winters resulting from climate change.

In situ monolayer patch clamp of acutely stimulated human iPSC-derived cardiomyocytes promotes consistent electrophysiological responses to SK channel inhibition

Human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) represent an in vitro model of cardiac function. Isolated iPSC-CMs, however, exhibit electrophysiological heterogeneity which hinders their utility in the study of certain cardiac currents. In the healthy adult heart, the current mediated by small conductance, calcium-activated potassium (SK) channels (ISK) is atrial-selective. Functional expression of ISK within atrial-like iPSC-CMs has not been explored thoroughly. The present study therefore aimed to investigate atrial-like iPSC-CMs as a model system for the study of ISK. iPSCs were differentiated using retinoic acid (RA) to produce iPSC-CMs which exhibited an atrial-like phenotype (RA-iPSC-CMs). Only 18% of isolated RA-iPSC-CMs responded to SK channel inhibition by UCL1684 and isolated iPSC-CMs exhibited substantial cell-to-cell electrophysiological heterogeneity. This variability was significantly reduced by patch clamp of RA-iPSC-CMs in situ as a monolayer (iPSC-ML). A novel method of electrical stimulation was developed to facilitate recording from iPSC-MLs via In situ Monolayer Patch clamp of Acutely Stimulated iPSC-CMs (IMPASC). Using IMPASC, > 95% of iPSC-MLs could be paced at a 1 Hz. In contrast to isolated RA-iPSC-CMs, 100% of RA-iPSC-MLs responded to UCL1684, with APD50 being prolonged by 16.0 ± 2.0 ms (p < 0.0001; n = 12). These data demonstrate that in conjunction with IMPASC, RA-iPSC-MLs represent an improved model for the study of ISK. IMPASC may be of wider value in the study of other ion channels that are inconsistently expressed in isolated iPSC-CMs and in pharmacological studies.