bluuebunny/crossref_metadata_2025 huggingface dataset:
A simulation study on different STDP models concerning localized gamma oscillations
Authors: Hauser Florian , Knoblauch Andreas , Palm Günther
Published: January 2023

Gamma oscillations are a prominent feature in experimental as well as theoretical descriptions of brain activity. One of the network models which has the capability to generate such oscillations is what we call a local cell assembly (CA), i.e. a group of neighboring neurons which are strongly interconnected in an excitatory manner. Postulated by experimenters and extensively used in theoretical studies, these local networks seem to be a good candidate for investigating the impact of biological constraints given by models of spike-timing-dependent plasticity (STDP) on local gamma oscillating structures in the mammalian brain. Therefore we fi*tted a two-compartment neuron model with AMPA- and NMDA-receptor mediated synaptic currents to desired properties of a local CA, meaning pattern completion and after-activity. We simulated 100 recurrently connected neurons with fi*xed axonal transmission delays. In addition, every neuron receives Poissonian spikes from 1000 input cells *firing at low background rate. During simulation the network is stimulated every second by increasing the input rate 10-fold for 35 msec. As a quality measure for keeping or even enhancing the properties of the network, we counted the relative amount of synapses with increased synaptic strengths with reference to the initial values. Three phenomenological STDP models (Song et al., Nature Neuroscience, 3, 2000; Pfi*ster and Gerstner, The J. of Neuroscience, 26, 2006; Clopath et al., Nature Neuroscience, 13, 2010) were implemented. Model-specifi*c parameters were varied in ranges determined by experimental measurements. We conclude that more recent STDP models which take into account frequency-dependent terms lead to a higher probability of strengthening synapses in a local CA (larger LTP region). This corresponds to experimental observations that long-term potentiation (LTP) outweighs long-term depression (LTD) in high-frequency pairing protocols. Furthermore, our simulations show that short axonal transmission delays clearly enlarge the LTP region of STDP parameter space.
The Army of One (Sample): the Characteristics of Sampling-based Probabilistic Neural Representations
Authors: Berkes Pietro , Turner Richard , Fiser Jozsef
Published: January 2023

There is growing evidence that humans and animals represent the uncertainty associated with sensory stimuli and utilize this uncertainty during planning and decision making in a statistically optimal way. Recently, a nonparametric framework for representing probabilistic information has been proposed whereby neural activity encodes samples from the distribution over external variables. Although such sample-based probabilistic representations have strong empirical and theoretical support, two major issues need to be clarified before they can be considered as viable candidate theories of cortical computation. First, in a fluctuating natural environment, can neural dynamics provide sufficient samples to accurately estimate a stimulus? Second, can such a code support accurate learning over biologically plausible time-scales? Although it is well known that sampling is statistically optimal if the number of samples is unlimited, biological constraints mean that estimation and learning in the cortex must be supported by a relatively small number of possibly dependent samples. We explored these issues in a cue combination task by comparing a neural circuit that employed a sampling-based representation to an optimal estimator. For static stimuli, we found that a single sample is sufficient to obtain an estimator with less than twice the optimal variance, and that performance improves with the inverse square root of the number of samples. For dynamic stimuli, with linear-Gaussian evolution, we found that the efficiency of the estimation improves significantly as temporal information stabilizes the estimate, and because sampling does not require a burn-in phase. Finally, we found that using a single sample, the dynamic model can accurately learn the parameters of the input neural populations up to a general scaling factor, which disappears for modest sample size. These results suggest that sample-based representations can support estimation and learning using a relatively small number of samples and are therefore highly feasible alternatives for performing probabilistic cortical computations.
The Attentional Routing Circuit: Receptive Field Modulation Through Nonlinear Dendritic Interactions
Authors: Bobier Bruce , Stewart Terrence , Eliasmith Chris
Published: January 2023

We present a model of attentional routing called the Attentional Routing Circuit (ARC) that extends an existing model of spiking neurons with dendritic nonlinearities. Specifically, we employ the Poirazi et al. (2003) pyramidal neuron in a population coding framework. ARC demonstrates that the dendritic nonlinearities can be exploited to result in selective routing, with a decrease in the number of cells needed by a factor of ~5 as compared with a linear dendrite model.Routing of attended information occurs through the modulation of feedforward visual signals by a cortical control signal specifying the location and size of the attended target. The model is fully specified in spiking single cells. Our approach differs from past work on shifter circuits by having more efficient control, and using a more biologically detailed substrate. Our approach differs from existing models that use gain fields by providing precise hypotheses about how the control signals are generated and distributed in a hierarchical model in spiking neurons. Further, the model accounts for numerous experimental findings regarding the timing, strength and extent of attentional modulation in ventral stream areas, and the perceived contrast enhancement of attended stimuli.To further demonstrate the plausibility of ARC, it is applied to the attention experiments of Womelsdorf et al. (2008) and tested in detail. For the simulations, the model has only two free parameters that influence its ability to match the experimental data, and without fitting, we show that it can account for the experimental observations of changes in receptive field (RF) gain and position with attention in macaques. In sum, the model provides an explanation of RF modulation as well as testable predictions about nonlinear cortical dendrites and attentional changes of receptive field properties.
Hierarchical inference of disparity
Authors: Tosic Ivana , Olshausen Bruno
Published: January 2023

Disparity selective cells in V1 respond to the correlated receptive fields of the left and right retinae, which do not necessarily correspond to the same object in the 3D scene, i.e., these cells respond equally to both false and correct stereo matches. On the other hand, neurons in the extrastriate visual area V2 show much stronger responses to correct visual matches [Bakin et al, 2000]. This indicates that a part of the stereo correspondence problem is solved during disparity processing in these two areas. However, the mechanisms employed by the brain to accomplish this task are not yet understood. Existing computational models are mostly based on cooperative computations in V1 [Marr and Poggio 1976, Read and Cumming 2007], without exploiting the potential benefits of the hierarchical structure between V1 and V2. Here we propose a two-layer graphical model for disparity estimation from stereo. The lower layer matches the linear responses of neurons with Gabor receptive fields across images. Nodes in the upper layer infer a sparse code of the disparity map and act as priors that help disambiguate false from correct matches. When learned on natural disparity maps, the receptive fields of the sparse code converge to oriented depth edges, which is consistent with the electrophysiological studies in macaque [von der Heydt et al, 2000]. Moreover, when such a code is used for depth inference in our two layer model, the resulting disparity map for the Tsukuba stereo pair [middlebury database] has 40% less false matches than the solution given by the first layer. Our model offers a demonstration of the hierarchical disparity computation, leading to testable predictions about V1-V2 interactions.
Cdon suppresses vascular smooth muscle calcification via repression of the Wnt/Runx2 Axis
Authors: Ahn Byeong-Yun , Jeong Yideul , Kim Sunghee , Zhang Yan , Kim Su Woo , Leem Young-Eun , Kang Jong-Sun
Published: January 2023

Osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs) is a risk factor associated with vascular diseases. Wnt signaling is one of the major mechanisms implicated in the osteogenic conversion of VSMCs. Since Cdon has a negative effect on Wnt signaling in distinct cellular processes, we sought to investigate the role of Cdon in vascular calcification. The expression of Cdon was significantly downregulated in VSMCs of the aortas of patients with atherosclerosis and aortic stenosis. Consistently, calcification models, including vitamin D3 (VD3)-injected mice and VSMCs cultured with calcifying media, exhibited reduced Cdon expression. Cdon ablation mice (cKO) exhibited exacerbated aortic stiffness and calcification in response to VD3 compared to the controls. Cdon depletion induced the osteogenic conversion of VSMCs accompanied by cellular senescence. The Cdon-deficient aortas showed a significant alteration in gene expression related to cell proliferation and differentiation together with Wnt signaling regulators. Consistently, Cdon depletion or overexpression in VSMCs elevated or attenuated Wnt-reporter activities, respectively. The deletion mutant of the second immunoglobulin domain (Ig2) in the Cdon ectodomain failed to suppress Wnt signaling and osteogenic conversion of VSMCs. Furthermore, treatment with purified recombinant proteins of the entire ectodomain or Ig2 domain of Cdon displayed suppressive effects on Wnt signaling and VSMC calcification. Our results demonstrate a protective role of Cdon in VSMC calcification by suppressing Wnt signaling. The Ig2 domain of Cdon has the potential as a therapeutic tool to prevent vascular calcification.
Hsa_circ_0021727 (circ-CD44) promotes ESCC progression by targeting miR-23b-5p to activate the TAB1/NFκB pathway
Authors: Meng Fan , Zhang Xiaokang , Wang Yanting , Lin Jie , Tang Yulin , Zhang Guisheng , Qiu Binqiang , Zeng Xingdu , Liu Weiyou , He Xin
Published: January 2023

Esophageal squamous cell carcinoma (ESCC) is characterized by high morbidity and mortality. Circular RNAs (circRNAs) play an important role in tumor progression. We discovered an aberrantly expressed circRNA (hsa_circ_0021727) in patients with ESCC. However, the mechanism of action of hsa_circ_0021727 in tumors is unclear. The present study aimed to investigate the biological role of hsa_circ_0021727 and its mechanism in ESCC progression. We screened for the expression of hsa_circ_0021727 in ESCC patients. Patients with ESCC with high expression of hsa_circ_0021727 had shorter survival than those with low expression. Hsa_circ_0021727 promoted the proliferation, invasion, and migration of ESCC cells. However, miR-23b-5p inhibited this ability of hsa_circ_0021727. MiR-23b-5p acts by targeting TAK1-binding protein 1 (TAB1). Upregulation of TAB1 can activate the nuclear factor kappa B (NFκB) pathway. Hsa_circ_0021727 promoted ESCC progression by activating TAB1/NFκB pathway by sponging miR-23b-5p. In addition, in vivo experiments also confirmed that hsa_circ_0021727 could promote the proliferation, invasion, and migration of ESCC cells. In short, hsa_circ_0021727 promotes ESCC progression by targeting miR-23b-5p to activate the TAB1/NFκB pathway. These findings might provide potential targets to treat ESCC.
Dynamics of the fcc-to-bcc phase transition in single-crystalline PdCu alloy nanoparticles
Authors: Jiang Yingying , Duchamp Martial , Ang Shi Jun , Yan Hongwei , Tan Teck Leong , Mirsaidov Utkur
Published: January 2023

Two most common crystal structures in metals and metal alloys are body-centered cubic (bcc) and face-centered cubic (fcc) structures. The phase transitions between these structures play an important role in the production of durable and functional metal alloys. Despite their technological significance, the details of such phase transitions are largely unknown because of the challenges associated with probing these processes. Here, we describe the nanoscopic details of an fcc-to-bcc phase transition in PdCu alloy nanoparticles (NPs) using in situ heating transmission electron microscopy. Our observations reveal that the bcc phase always nucleates from the edge of the fcc NP, and then propagates across the NP by forming a distinct few-atoms-wide coherent bcc–fcc interface. Notably, this interface acts as an intermediate precursor phase for the nucleation of a bcc phase. These insights into the fcc-to-bcc phase transition are important for understanding solid − solid phase transitions in general and can help to tailor the functional properties of metals and their alloys.
Disruption of mitochondrial dynamics triggers muscle inflammation through interorganellar contacts and mitochondrial DNA mislocation
Authors: Irazoki Andrea , Gordaliza-Alaguero Isabel , Frank Emma , Giakoumakis Nikolaos Nikiforos , Seco Jordi , Palacín Manuel , Gumà Anna , Sylow Lykke , Sebastián David , Zorzano Antonio
Published: January 2023

Some forms of mitochondrial dysfunction induce sterile inflammation through mitochondrial DNA recognition by intracellular DNA sensors. However, the involvement of mitochondrial dynamics in mitigating such processes and their impact on muscle fitness remain unaddressed. Here we report that opposite mitochondrial morphologies induce distinct inflammatory signatures, caused by differential activation of DNA sensors TLR9 or cGAS. In the context of mitochondrial fragmentation, we demonstrate that mitochondria-endosome contacts mediated by the endosomal protein Rab5C are required in TLR9 activation in cells. Skeletal muscle mitochondrial fragmentation promotes TLR9-dependent inflammation, muscle atrophy, reduced physical performance and enhanced IL6 response to exercise, which improved upon chronic anti-inflammatory treatment. Taken together, our data demonstrate that mitochondrial dynamics is key in preventing sterile inflammatory responses, which precede the development of muscle atrophy and impaired physical performance. Thus, we propose the targeting of mitochondrial dynamics as an approach to treating disorders characterized by chronic inflammation and mitochondrial dysfunction.
Conformational plasticity of NaK2K and TREK2 potassium channel selectivity filters
Authors: Matamoros Marcos , Ng Xue Wen , Brettmann Joshua B. , Piston David W. , Nichols Colin G.
Published: January 2023

The K+ channel selectivity filter (SF) is defined by TxGYG amino acid sequences that generate four identical K+ binding sites (S1-S4). Only two sites (S3, S4) are present in the non-selective bacterial NaK channel, but a four-site K+-selective SF is obtained by mutating the wild-type TVGDGN SF sequence to a canonical K+ channel TVGYGD sequence (NaK2K mutant). Using single molecule FRET (smFRET), we show that the SF of NaK2K, but not of non-selective NaK, is ion-dependent, with the constricted SF configuration stabilized in high K+ conditions. Patch-clamp electrophysiology and non-canonical fluorescent amino acid incorporation show that NaK2K selectivity is reduced by crosslinking to limit SF conformational movement. Finally, the eukaryotic K+ channel TREK2 SF exhibits essentially identical smFRET-reported ion-dependent conformations as in prokaryotic K+ channels. Our results establish the generality of K+-induced SF conformational stability across the K+ channel superfamily, and introduce an approach to study manipulation of channel selectivity.
Hospital crowdedness evaluation and in-hospital resource allocation based on image recognition technology
Authors: Deng Lijia , Cheng Fan , Gao Xiang , Yu Wenya , Shi Jianwei , Zhou Liang , Zhang Lulu , Li Meina , Wang Zhaoxin , Zhang Yu-Dong , Lv Yipeng
Published: January 2023

How to allocate the existing medical resources reasonably, alleviate hospital congestion and improve the patient experience are problems faced by all hospitals. At present, the combination of artificial intelligence and the medical field is mainly in the field of disease diagnosis, but lacks successful application in medical management. We distinguish each area of the emergency department by the division of medical links. In the spatial dimension, in this study, the waitlist number in real-time is got by processing videos using image recognition via a convolutional neural network. The congestion rate based on psychology and architecture is defined for measuring crowdedness. In the time dimension, diagnosis time and time-consuming after diagnosis are calculated from visit records. Factors related to congestion are analyzed. A total of 4717 visit records from the emergency department and 1130 videos from five areas are collected in the study. Of these, the waiting list of the pediatric waiting area is the largest, including 10,436 (person-time) people, and its average congestion rate is 2.75, which is the highest in all areas. The utilization rate of pharmacy is low, with an average of only 3.8 people using it at the one time. Its average congestion rate is only 0.16, and there is obvious space waste. It has been found that the length of diagnosis time and the length of time after diagnosis are related to age, the number of diagnoses and disease type. The most common disease type comes from respiratory problems, accounting for 54.3%. This emergency department has congestion and waste of medical resources. People can use artificial intelligence to investigate the congestion in hospitals effectively. Using artificial intelligence methods and traditional statistics methods can lead to better research on healthcare resource allocation issues in hospitals.
Response of woody vegetation to bush thinning on freehold farmlands in north-central Namibia
Authors: Nghikembua Matti T. , Marker Laurie L. , Brewer Bruce , Leinonen Arvo , Mehtätalo Lauri , Appiah Mark , Pappinen Ari
Published: January 2023

Bush encroachment affects much of the Namibian woodland landscape, causing significant loss of open savannah habitat and farm profits. Thinning of the trees/shrubs is recommended; however, research is required to identify the overall efficacy and effects of this method on the woodland habitat. We aimed to examine the effect of the thinning strategy applied on the vegetation structure of encroaching tree/shrub species, as well as the sighting lines of the habitat. Vegetation surveys were done on three freehold farms in north-central Namibia. The study utilised a combination of a blocked and split-plot study design: each block consisted of a pair of thinned and non-thinned plots with multiple subplots. Thinned plots had been manually thinned, with a post-thinning age of three years or more. Results revealed that tree/shrub abundance differed between species; thinned areas had the least abundance and overall species-treatment interactions were significant. Thinning caused a significant reduction in overall tree/shrub densities, settling within the recommended range for the area. Thinning also significantly reduced the average tree/shrub height, canopy area, medium-sized trees/shrubs, and increased sighting lines. This confirms a bush encroachment mitigation strategy that favours grass cover, and wildlife that rely on longer sighting lines for safety or when hunting.
Monitoring of plant-induced electrical signal of pepper plants (Capsicum annuum L.) according to urea fertilizer application
Authors: Kim Han Na , Seok Yeong Ju , Park Gyung Min , Vyavahare Govind , Park Jin Hee
Published: January 2023

Plant-induced electrical signals (PIES) can be non-destructively monitored by inserting electrodes into plant stems, which reflect plant nutrient and water uptake. The main objective of this study was to evaluate the growth of pepper plants with different urea applications (low fertilizer: N0, Control: N1, and high fertilizer: N2) in soil by monitoring PIES. The PIES value was found to be low in the low urea treatment group while the two times higher urea applied pepper had the highest PIES value. The nutritional content of the stem, leaves and soil did not correlate with PIES because of dilution effect by high biomass with high urea application, but principal component analysis showed that the PIES was positively associated with pepper biomass and soil EC. The high fertilizer did not affect chlorophyll and proline contents in pepper leaves. The assessment of plant growth by PIES has advantages because non-destructive, real time and remote monitoring is possible. Therefore, PIES monitoring of different plants grown under various cultivation environments is useful method to evaluate plant activity and growth.
Enzyme-independent catabolism of cysteine with pyridoxal-5′-phosphate
Authors: Mulay Prajakatta , Chen Cindy , Krishna Vijay
Published: January 2023

Pyridoxal-5′-phosphate (PLP) is a versatile cofactor that assists in different types of enzymatic reactions. PLP has also been reported to react with substrates and catalyze some of these reactions independent of enzymes. One such catalytic reaction is the breakdown of cysteine to produce hydrogen sulfide (H2S) in the presence of multivalent metal ions. However, the enzyme-independent catalytic activity of PLP in catabolizing cysteine in the absence of multivalent ions is unknown. In this study, we show that PLP reacts with cysteine to form a thiazolidine product, which is supported by quantum chemical calculations of the absorption spectrum. The reaction of PLP with cysteine is dependent on ionic strength and pH. The thiazolidine product slowly decomposes to produce H2S and the PLP regenerates to its active form with longer reaction times (> 24 h), suggesting that PLP can act as a catalyst. We propose an enzyme-independent plausible reaction mechanism for PLP catalyzed cysteine breakdown to produce H2S, which proceeds through the formation of thiazolidine ring intermediates that later hydrolyzes slowly to regenerate the PLP. This work demonstrates that PLP catalyzes cysteine breakdown in the absence of enzymes, base, and multivalent metal ions to produce H2S.
Transcriptional activity mediated by β-CATENIN and TCF/LEF family members is completely dispensable for survival and propagation of multiple human colorectal cancer cell lines
Authors: Fröhlich Janna , Rose Katja , Hecht Andreas
Published: January 2023

Unrestrained transcriptional activity of β-CATENIN and its binding partner TCF7L2 frequently underlies colorectal tumor initiation and is considered an obligatory oncogenic driver throughout intestinal carcinogenesis. Yet, theTCF7L2gene carries inactivating mutations in about 10% of colorectal tumors and is non-essential in colorectal cancer (CRC) cell lines. To determine whether CRC cells acquire TCF7L2-independence through cancer-specific compensation by other T-cell factor (TCF)/lymphoid enhancer-binding factor (LEF) family members, or rather lose addiction to β-CATENIN/TCF7L2-driven gene expression altogether, we generated multiple CRC cell lines entirely negative for TCF/LEF or β-CATENIN expression. Survival of these cells and the ability to propagate them demonstrate their complete β-CATENIN- and TCF/LEF-independence. Nonetheless, one β-CATENIN-deficient cell line eventually became senescent, and absence of TCF/LEF proteins and β-CATENIN consistently impaired CRC cell proliferation, reminiscent of mitogenic effects of WNT/β-CATENIN signaling in the healthy intestine. Despite this common phenotype, β-CATENIN-deficient cells exhibited highly cell-line-specific gene expression changes with little overlap between β-CATENIN- and TCF7L2-dependent transcriptomes. Apparently, β-CATENIN and TCF7L2 independently control sizeable fractions of their target genes. The observed divergence of β-CATENIN and TCF7L2 transcriptional programs, and the finding that neither β-CATENIN nor TCF/LEF activity is strictly required for CRC cell survival has important implications when evaluating these factors as potential drug targets.
Antiplasmodial activity, structure–activity relationship and studies on the action of novel benzimidazole derivatives
Authors: Escala Nerea , Pineda Laura M. , Ng Michelle G. , Coronado Lorena M. , Spadafora Carmenza , del Olmo Esther
Published: January 2023

Malaria cases and deaths keep being excessively high every year. Some inroads gained in the last two decades have been eroded especially due to the surge of resistance to most antimalarials. The search for new molecules that can replace the ones currently in use cannot stop. In this report, the synthesis of benzimidazole derivatives guided by structure–activity parameters is presented. Thirty-six molecules obtained are analyzed according to their activity against P. falciparum HB3 strain based on the type of substituent on rings A and B, their electron donor/withdrawing, as well as their dimension/spatial properties. There is a preference for electron donating groups on ring A, such as Me in position 5, or better, 5, 6-diMe. Ring B must be of the pyridine type such as picolinamide, other modifications are generally not favorable. Two molecules, 1 and 33 displayed antiplasmodial activity in the high nanomolar range against the chloroquine sensitive strain, with selectivity indexes above 10. Activity results of 1, 12 and 16 on a chloroquine resistance strain indicated an activity close to chloroquine for compound 1. Analysis of some of their effect on the parasites seem to suggest that 1 and 33 affect only the parasite and use a route other than interference with hemozoin biocrystallization, the route used by chloroquine and most antimalarials.
Specific AAV2/PHP.eB-mediated gene transduction of CA2 pyramidal cells via injection into the lateral ventricle
Authors: Okamoto Kazuki , Kamikubo Yuji , Yamauchi Kenta , Okamoto Shinichiro , Takahashi Megumu , Ishida Yoko , Koike Masato , Ikegaya Yuji , Sakurai Takashi , Hioki Hiroyuki
Published: January 2023

Given its limited accessibility, the CA2 area has been less investigated compared to other subregions of the hippocampus. While the development of transgenic mice expressing Cre recombinase in the CA2 has revealed unique features of this area, the use of mouse lines has several limitations, such as lack of specificity. Therefore, a specific gene delivery system is required. Here, we confirmed that the AAV-PHP.eB capsid preferably infected CA2 pyramidal cells following retro-orbital injection and demonstrated that the specificity was substantially higher after injection into the lateral ventricle. In addition, a tropism for the CA2 area was observed in organotypic slice cultures. Combined injection into the lateral ventricle and stereotaxic injection into the CA2 area specifically introduced the transgene into CA2 pyramidal cells, enabling us to perform targeted patch-clamp recordings and optogenetic manipulation. These results suggest that AAV-PHP.eB is a versatile tool for specific gene transduction in CA2 pyramidal cells.
New magneto-polaron resonances in a monolayer of a transition metal dichalcogenide
Authors: Trallero-Giner Carlos , Santiago-Pérez Darío G. , Fomin Vladimir M.
Published: January 2023

Transition metal dichalcogenide (TMD) semiconductors are two-dimensional materials with great potential for the future of nano-optics and nano-optoelectronics as well as the rich and exciting development of basic research. The influence of an external magnetic field on a TMD monolayer raises a new question: to unveil the behavior of the magneto-polaron resonances (MPRs) associated with the phonon symmetry inherent in the system. It is shown that the renormalized Landau energy levels are modified by the interplay of the long-range Pekar–Fröhlich (PF) and short-range deformation potential (DP) interactions. This leads to a new series of MPRs involving the optical phonons at the center of the Brillouin zone. The coupling of the two Landau levels with the LO and $$A_1$$

A
1

optical phonon modes provokes resonant splittings of double avoided-crossing levels giving rise to three excitation branches. This effect appears as bigger energy gaps at the anticrossing points in the renormalized Landau levels. To explore the interplay between the MPRs, the electron-phonon interactions (PF and DP) and the couplings between adjacent Landau levels, a full Green’s function treatment for the evaluation of the energy and its life-time broadening is developed. A generalization of the two-level approach is performed for the description of the new MPR branches. The obtained results are a guideline for the magneto-optical experiments in TMDs, where three MPR peaks should be observable.
Enhanced angiogenic properties of umbilical cord blood primed by OP9 stromal cells ameliorates neurological deficits in cerebral infarction mouse model
Authors: Yoshida Yasunori , Takeda Yuki , Yamahara Kenichi , Yamamoto Hanae , Takagi Toshinori , Kuramoto Yoji , Nakano-Doi Akiko , Nakagomi Takayuki , Soma Toshihiro , Matsuyama Tomohiro , Doe Nobutaka , Yoshimura Shinichi
Published: January 2023

Umbilical cord blood (UCB) transplantation shows proangiogenic effects and contributes to symptom amelioration in animal models of cerebral infarction. However, the effect of specific cell types within a heterogeneous UCB population are still controversial. OP9 is a stromal cell line used as feeder cells to promote the hematoendothelial differentiation of embryonic stem cells. Hence, we investigated the changes in angiogenic properties, underlying mechanisms, and impact on behavioral deficiencies caused by cerebral infarction in UCB co-cultured with OP9 for up to 24 h. In the network formation assay, only OP9 pre-conditioned UCB formed network structures. Single-cell RNA sequencing and flow cytometry analysis showed a prominent phenotypic shift toward M2 in the monocytic fraction of OP9 pre-conditioned UCB. Further, OP9 pre-conditioned UCB transplantation in mice models of cerebral infarction facilitated angiogenesis in the peri-infarct lesions and ameliorated the associated symptoms. In this study, we developed a strong, fast, and feasible method to augment the M2, tissue-protecting, pro-angiogenic features of UCB using OP9. The ameliorative effect of OP9-pre-conditioned UCB in vivo could be partly due to promotion of innate angiogenesis in peri-infarct lesions.
Identification of TP53 mutations in circulating tumour DNA in high grade serous ovarian carcinoma using next generation sequencing technologies
Authors: Calapre Leslie , Giardina Tindaro , Beasley Aaron B. , Reid Anna L. , Stewart Colin , Amanuel Benhur , Meniawy Tarek M. , Gray Elin S.
Published: January 2023

Plasma circulating tumour DNA (ctDNA) has been suggested to be a viable biomarker of response to treatment in patients with high grade serous ovarian carcinoma (HGSOC). TP53 mutations are present in more than 90% of HGSOCs but somatic variants are distributed across all exonic regions of the gene, requiring next generation sequencing (NGS) technologies for mutational analysis. In this study, we compared the suitability of the Accel (Swift) and Oncomine (ThermoFisher) panels for identification of TP53 mutations in ctDNA of HGSOC patients (N = 10). Only 6 patients (60%) were found to have TP53 mutations using the ACCEL panel but the addition of molecular tags in the Oncomine panel improved ctDNA detection with at least one mutation detected in all cases (100%). Orthogonal validation of the 14 somatic variants found by Oncomine, using droplet digital PCR, confirmed 79% (11/14) of the identified mutations. Overall, the Oncomine panel with unique molecular identifiers (UMI) appears more useful for ctDNA analysis in HGSOC.
Family income and cardiovascular disease risk in American adults
Authors: Minhas Abdul Mannan Khan , Jain Vardhmaan , Li Monica , Ariss Robert W. , Fudim Marat , Michos Erin D. , Virani Salim S. , Sperling Laurence , Mehta Anurag
Published: January 2023

Socioeconomic status is an overlooked risk factor for cardiovascular disease (CVD). Low family income is a measure of socioeconomic status and may portend greater CVD risk. Therefore, we assessed the association of family income with cardiovascular risk factor and disease burden in American adults. This retrospective analysis included data from participants aged ≥ 20 years from the National Health and Nutrition Examination Survey (NHANES) cycles between 2005 and 2018. Family income to poverty ratio (PIR) was calculated by dividing family (or individual) income by poverty guidelines specific to the survey year and used as a measure of socioeconomic status. The association of PIR with the presence of cardiovascular risk factors and CVD as well as cardiac mortality and all-cause mortality was examined. We included 35,932 unweighted participants corresponding to 207,073,472 weighted, nationally representative participants. Participants with lower PIR were often female and more likely to belong to race/ethnic minorities (non-Hispanic Black, Mexican American, other Hispanic). In addition, they were less likely to be married/living with a partner, to attain college graduation or higher, or to have health insurance. In adjusted analyses, the prevalence odds of diabetes mellitus, hypertension, coronary artery disease (CAD), congestive heart failure (CHF), and stroke largely decreased in a step-wise manner from highest (≥ 5) to lowest PIR (< 1). In adjusted analysis, we also noted a mostly dose-dependent association of PIR with the risk of all-cause and cardiac mortality during a mean 5.7 and 5.8 years of follow up, respectively. Our study demonstrates a largely dose-dependent association of PIR with hypertension, diabetes mellitus, CHF, CAD and stroke prevalence as well as incident all-cause mortality and cardiac mortality in a nationally representative sample of American adults. Public policy efforts should be directed to alleviate these disparities to help improve cardiovascular outcomes in vulnerable groups with low family income.
A deep network embedded with rough fuzzy discretization for OCT fundus image segmentation
Authors: Chen Qiong , Zeng Lirong , Lin Cong
Published: January 2023

The noise and redundant information are the main reasons for the performance bottleneck of medical image segmentation algorithms based on the deep learning. To this end, we propose a deep network embedded with rough fuzzy discretization (RFDDN) for OCT fundus image segmentation. Firstly, we establish the information decision table of OCT fundus image segmentation, and regard each category of segmentation region as a fuzzy set. Then, we use the fuzzy c-means clustering to get the membership degrees of pixels to each segmentation region. According to membership functions and the equivalence relation generated by the brightness attribute, we design the individual fitness function based on the rough fuzzy set, and use a genetic algorithm to search for the best breakpoints to discretize the features of OCT fundus images. Finally, we take the feature discretization based on the rough fuzzy set as the pre-module of the deep neural network, and introduce the deep supervised attention mechanism to obtain the important multi-scale information. We compare RFDDN with U-Net, ReLayNet, CE-Net, MultiResUNet, and ISCLNet on the two groups of 3D retinal OCT data. RFDDN is superior to the other five methods on all evaluation indicators. The results obtained by ISCLNet are the second only inferior to those obtained by RFDDN. DSC, sensitivity, and specificity of RFDDN are evenly 3.3%, 2.6%, and 7.1% higher than those of ISCLNet, respectively. HD95 and ASD of RFDDN are evenly 6.6% and 19.7% lower than those of ISCLNet, respectively. The experimental results show that our method can effectively eliminate the noise and redundant information in Oct fundus images, and greatly improve the accuracy of OCT fundus image segmentation while taking into account the interpretability and computational efficiency.
PEG–PLGA nanoparticles for encapsulating ciprofloxacin
Authors: Watcharadulyarat Natsorn , Rattanatayarom Monthira , Ruangsawasdi Nisarat , Patikarnmonthon Nisa
Published: January 2023

Antibiotic medications have been found to hinder the success of regenerative endodontic treatment due to the rapid degradation of the drug, and the acidic nature of ciprofloxacin (CIP) can be harmful to stem cells of the apical papilla (SCAPs), the cells responsible for regeneration. In this study, a nanocarrier system was used for controlled drug release for longer drug activity and less cytotoxicity to the cells. CIP was loaded in poly (ethylene glycol) methyl ether-block-poly (lactide-co-glycolide) (PEG–PLGA) nanoparticles (NPs) with an ion-pairing agent. The NPs demonstrated a monodispersed spherical morphology with a mean diameter of 120.7 ± 0.43 nm. The encapsulation efficiency of the CIP-loaded PEG–PLGA NPs was 63.26 ± 9.24%, and the loading content was 7.75 ± 1.13%. Sustained CIP release was achieved over 168 h and confirmed with theoretical kinetic models. Enhanced NP bactericidal activity was observed against Enterococcus faecalis. Additionally, CIP-loaded PEG–PLGA NPs had a low cytotoxic effect on SCAPs. These results suggest the use of a nanocarrier system to prolong the antibiotic activity, provide a sterile environment, and prevent reinfection by the bacteria remaining in the root canal during regenerative endodontic treatment.
Knowledge-based expedited parameter tuning of microwave passives by means of design requirement management and variable-resolution EM simulations
Authors: Koziel Slawomir , Pietrenko-Dabrowska Anna , Raef Ali Ghaffarlouy
Published: January 2023

The importance of numerical optimization techniques has been continually growing in the design of microwave components over the recent years. Although reasonable initial designs can be obtained using circuit theory tools, precise parameter tuning is still necessary to account for effects such as electromagnetic (EM) cross coupling or radiation losses. EM-driven design closure is most often realized using gradient-based procedures, which are generally reliable as long as the initial design is sufficiently close to the optimum one. Otherwise, the search process may end up in a local optimum that is of insufficient quality. Furthermore, simulation-based optimization incurs considerable computational expenses, which are often impractically high. This paper proposes a novel parameter tuning procedure, combining a recently reported design specification management scheme, and variable-resolution EM models. The former allows for iteration-based automated modification of the design goals to make them accessible in every step of the search process, thereby improving its immunity to poor starting points. The knowledge-based procedure for the adjustment of the simulation model fidelity is based on the convergence status of the algorithm and discrepancy between the current and the original performance specifications. Due to using lower-resolution EM simulations in early phase of the optimization run, considerable CPU savings can be achieved, which are up to 60 percent over the gradient-based search employing design specifications management and numerical derivatives. Meanwhile, as demonstrated using three microstrip circuits, the computational speedup is obtained without design quality degradation.
Polymer-derived SiOC reinforced with core–shell nanophase structure of ZrB2/ZrO2 for excellent and stable high-temperature microwave absorption (up to 900 °C)
Authors: Jia Yujun , Yang Ni , Xu Shaofan , Snyder Alexander D. , Patrick Jason F. , Kumar Rajan , Zhang Dajie , Xu Chengying
Published: January 2023

Microwave absorbing materials for high-temperature harsh environments are highly desirable for aerodynamically heated parts and engine combustion induced hot spots of aircrafts. This study reports ceramic composites with excellent and stable high-temperature microwave absorption in air, which are made of polymer-derived SiOC reinforced with core–shell nanophase structure of ZrB2/ZrO2. The fabricated ceramic composites have a crystallized t-ZrO2 interface between ZrB2 and SiOC domains. The ceramic composites exhibit stable dielectric properties, which are relatively insensitive to temperature change from room temperature to 900 °C. The return loss exceeds − 10 dB, especially between 28 and 40 GHz, at the elevated temperatures. The stable high-temperature electromagnetic (EM) absorption properties are attributed to the stable dielectric and electrical properties induced by the core–shell nanophase structure of ZrB2/ZrO2. Crystallized t-ZrO2 serve as nanoscale dielectric interfaces between ZrB2 and SiOC, which are favorable for EM wave introduction for enhancing polarization loss and absorption. Existence of t-ZrO2 interface also changes the temperature-dependent DC conductivity of ZrB2/SiOC ceramic composites when compared to that of ZrB2 and SiOC alone. Experimental results from thermomechanical, jet flow, thermal shock, and water vapor tests demonstrate that the developed ceramic composites have high stability in harsh environments, and can be used as high-temperature wide-band microwave absorbing structural materials.
Isocratic ion pair chromatography for estimation of novel combined inhalation therapy that blocks coronavirus replication in chronic asthmatic patients
Authors: Hammouda Mohammed E. A. , Salem Yomna A. , El-Ashry Saadia M. , El-Enin Mohamed A. Abu
Published: January 2023

A rapid and sensitive isocratic ion-pair chromatographic method was developed for the accurate analysis of ternary mixtures of formoterol, tiotropium, and ciclesonide in their novel combined inhalation that is widely used for the symptomatic treatment of patients with chronic obstructive disease. Analytical separation was performed using a C8 column and ion pair mobile phase composed of acetonitrile: acidified deionized water (55: 45% v/v) containing 0.025% sodium dodecyl sulfate. The pH was adjusted to 3.0 using orthophosphoric acid and eluted isocratically at 2.0 mL/min and 40 °C applying UV detection at 237 nm. The calibration ranges were found to be 0.3–9.0 µg/mL for formoterol, 0.45–13.5 µg/mL for tiotropium, and 10.0–300.0 µg/mL concerning ciclesonide. The proposed method exhibited good repeatability, accuracy, and sensitivity (R.S.D. < 2.0%). The approach is rapid (run time does not exceed 15 min) and achieves satisfactory resolution (resolution factors = 7.45 and 5.3 between formoterol and tiotropium and tiotropium and ciclesonide respectively). The sensitivity and the efficiency of the proposed method permit their successful estimation with a recovery percentage ± SD of 99.33% ± 0.43 for formoterol, 99.15% ± 0.60 for tiotropium, and 99.90% ± 0.41 for ciclesonide.
Dependence of column ozone on future ODSs and GHGs in the variability of 500-ensemble members
Authors: Akiyoshi Hideharu , Kadowaki Masanao , Yamashita Yousuke , Nagatomo Toshiharu
Published: January 2023

State-of-the-art chemistry–climate models (CCMs) have indicated that a future decrease in ozone-depleting substances (ODSs) combined with an increase in greenhouse gases (GHGs) would increase the column ozone amount in most regions except the tropics and Antarctic. However, large Arctic ozone losses have occurred at a frequency of approximately once per decade since the 1990s (1997, 2011 and 2020), despite the ODS concentration peaking in the mid-1990s. To understand this, CCMs were used to conduct 24 experiments with ODS and GHG concentrations set based on predicted values for future years; each experiment consisted of 500-member ensembles. The 50 ensemble members with the lowest column ozone in the mid- and high latitudes of the Northern Hemisphere showed a clear ODS dependence associated with low temperatures and a strong westerly zonal mean zonal wind. Even with high GHG concentrations, several ensemble members showed extremely low spring column ozone in the Arctic when ODS concentration remained above the 1980–1985 level. Hence, ODS concentrations should be reduced to avoid large ozone losses in the presence of a stable Arctic polar vortex. The average of the lowest 50 members indicates that GHG increase towards the end of the twenty-first century will not cause worse Arctic ozone depletion.
Ratiometric fluorescent semiconducting polymer dots for temperature sensing
Authors: He Shuyi , Wu Steven
Published: January 2023

A ratiometric fluorescent nanothermometer based on Pdots-Eu for monitoring temperature changes in vitro.
Single-tube one-step gel-based RT-RPA/PCR for highly sensitive molecular detection of HIV
Authors: Uno Naoki , Li Ziyue , Liu Changchun
Published: January 2023

Single-tube one-step gel-based RT-RPA/PCR platform for simple, rapid and highly sensitive molecular detection of HIV.
Determination of volatile components in cumin by microwave-assisted PDMS/GO/DES headspace solid phase extraction combined with GC-MS
Authors: Li Dandan , Jiang Xinxing , Zhang Yaxue , Xue Wenxia , Fu Jihong
Published: January 2023

A novel approach based on polydimethylsiloxane/graphene oxide/deep eutectic solvent (PDMS/GO/DES) sponge headspace solid phase extraction followed by GC-MS was successfully developed to determine the volatile components in cumin.
Recent advances in catalytic pnictogen bond forming reactionsviadehydrocoupling and hydrofunctionalization
Authors: Reuter Matthew B. , Seth Dennis M. , Javier-Jiménez Diego R. , Finfer Emma J. , Beretta Evan A. , Waterman Rory
Published: January 2023

The metal–pnictogen bond has rich and varied reactivity. The differences and similarities down the group and impacts on catalytic reactions with these elements is explored in this Feature.
The computational road to reactivity scales
Authors: Vahl Maike , Proppe Jonny
Published: January 2023

Reactivity scales are powerful research tools. This tutorial shows how to create and use them on the computer.
Tuning functionalized hexagonal boron nitride quantum dots for full visible-light fluorescence emission
Authors: Gao Yuan-Jun , Kwak Sang Kyu
Published: January 2023

DFT, TD-DFT and MS-CASPT2 studies reveal the tunable visible emission of functionalized hexagonal boron nitride quantum dots.
Near-UV excited multifunctional near-infrared phosphors for anti-counterfeiting and ratiometric thermometer applications
Authors: Ma Zhe , Liu Hongmin , Xie Siyuan , Zeng Qingguang , Guo Yue , Wen Dawei
Published: January 2023

Near-UV excitable near-infrared Ca2Sn2Al2O9:Cr3+,Si4+phosphors for anti-counterfeiting and high relative sensitivity (≥1%/K) in the temperature range of 25–125 °C, especially in bio-thermometry (25–50 °C) for luminescence ratiometric thermometers.
N-dopants optimize the utilization of spontaneously formed photocharges in organic solar cells
Authors: Tang Yabing , Zheng Hong , Zhou Xiaobo , Tang Zheng , Ma Wei , Yan Han
Published: January 2023

N-dopants optimize the utilization of spontaneously formed photocharges by reducing the exciton binding energy and segregating the counter charges in non-fullerene acceptors.
Amomum subulatum mitigates experimental thoracic radiation-induced lung injury by regulating antioxidant status and inflammatory responses
Authors: Drishya Sudarsanan , Dhanisha Suresh Sulekha , Raghukumar Paramu , Guruvayoorappan Chandrasekharan
Published: January 2023

Mechanism of action of MEAS in mitigating RILI.
Porous recyclable sponges with controllable and durable shape memory
Authors: Cao Jinfeng , Gui Cong , Feng Shengyu
Published: January 2023

A porous silicone sponge with exquisite structures, and controllable and durable shape memory property was designed and synthesized by a one pot click reaction.
Examining the effect of the crown ether, 18-crown-6, on lysozyme fibrillation
Authors: Basu Anirban
Published: January 2023

18-crown-6 retarded fibrillogenesis in lysozyme.
Efficient and bright green InP quantum dot light-emitting diodes enabled by a self-assembled dipole interface monolayer
Authors: Li Lufa , Luo Yaning , Wu Qianqian , Wang Lin , Jia Guohua , Chen Tao , Zhang Chengxi , Yang Xuyong
Published: January 2023

A self-assembled dipole interface monolayer is a possible strategy to obtain efficient and bright green InP quantum dot light-emitting diodes.