Towards interpretable machine learning for observational quantification of soil heavy metal concentrations under environmental constraints.

Monitoring heavy metal concentrations in soils is central to assessing agricultural production safety. Satellite observations permit inferring concentrations from spectrum, thereby contributing to the prevention and control of soil heavy metal pollution. However, heavy metals exhibit weak spectral responses, particularly at low and medium concentrations, and are predominantly influenced by other soil components. Machine learning (ML)-driven modelling can produce predictions but lacks interpretability. Here, we present an interpretable ML framework for concentration quantification modelling and investigated the contributions of spectral and environmental factors-pH and organic carbon-to the estimation of metals with multiple concentration gradients, as analysed through SHAP (SHapley Additive exPlanations) data derived from four learning-based scenarios. The results indicated that scenarios SHC (spectral, pH, and organic carbon) and SH (spectral and pH) were the most optimal for chromium (Cr) [RPD = 1.42, Adj R2 = 0.62], and cadmium (Cd) [RPD = 1.80, Adj R2 = 0.80]. Under environmental constraints, the spectral predictability for Cr and Cd was improved by 67 % and 87 %, respectively. We concluded that interpretable modelling, utilising both spectral and soil environmental factors, holds significant potential for estimating heavy metals across concentration gradients. It is recommended that samples with higher organic carbon content and lower pH be selected to enhance Cr and Cd predictions. An advanced grasp of interpretable predictions facilitates earlier warning of heavy metal contamination and guides the formulation of robust sampling strategies.

99mTc-3PRGD2 SPECT/CT Imaging for Diagnosing Lymph Node Metastasis of Primary Malignant Lung Tumors.

OBJECTIVE: To evaluate 99mtechnetium-three polyethylene glycol spacers-arginine-glycine-aspartic acid (99mTc-3PRGD2) single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging for diagnosing lymph node metastasis of primary malignant lung neoplasms. MATERIALS AND METHODS: We prospectively enrolled 26 patients with primary malignant lung tumors who underwent 99mTc-3PRGD2 SPECT/CT and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT imaging. Both imaging methods were analyzed in qualitative (visual dichotomous and 5-point grades for lymph nodes and lung tumors, respectively) and semi-quantitative (maximum tissue-to-background radioactive count) manners for the lymph nodes and lung tumors. The performance of the differentiation of lymph nodes with and without metastasis was determined at the per-lymph node station and per-patient levels using histopathological results as the reference standard. RESULTS: Total 42 stations had metastatic lymph nodes and 136 stations had benign lymph nodes. The differences between metastatic and benign lymph nodes in the visual qualitative and semiquantitative analyses of 99mTc-3PRGD2 SPECT/CT and 18F-FDG PET/CT were statistically significant (all P < 0.001). The area under the receiver operating characteristic curve (AUC) in the semi-quantitative analysis of 99mTc-3PRGD2 SPECT/CT was 0.908 (95% confidence interval [CI], 0.851-0.966), and the sensitivity, specificity, positive predictive value, and negative predictive value were 0.86 (36/42), 0.88 (120/136), 0.69 (36/52), and 0.95 (120/126), respectively. Among the 26 patients (including two patients each with two lung tumors), 15 had pathologically confirmed lymph node metastasis. The difference between primary lung lesions in patients with and without lymph node metastasis was statistically significant only in the semi-quantitative analysis of 99mTc-3PRGD2 SPECT/CT (P = 0.007), with an AUC of 0.807 (95% CI, 0.641-0.974). CONCLUSION: 99mTc-3PRGD2 SPECT/CT imaging may notably perform in the direct diagnosis of lymph node metastasis of primary malignant lung tumors and indirectly predict the presence of lymph node metastasis through uptake in the primary lesions.

Patient Brain Organoids Identify a Link between the 16p11.2 Copy Number Variant and the RBFOX1 Gene.

Copy number variants (CNVs) that delete or duplicate 30 genes within the 16p11.2 genomic region give rise to a range of neurodevelopmental phenotypes with high penetrance in humans. Despite the identification of this small region, the mechanisms by which 16p11.2 CNVs lead to disease are unclear. Relevant models, such as human cortical organoids (hCOs), are needed to understand the human-specific mechanisms of neurodevelopmental disease. We generated hCOs from 17 patients and controls, profiling 167,958 cells with single-cell RNA-sequencing analysis, which revealed neuronal-specific differential expression of genes outside the 16p11.2 region that are related to cell-cell adhesion, neuronal projection growth, and neurodevelopmental disorders. Furthermore, 16p11.2 deletion syndrome organoids exhibited reduced mRNA and protein levels of RBFOX1, a gene that can also harbor CNVs linked to neurodevelopmental phenotypes. We found that the genes previously shown to be regulated by RBFOX1 are also perturbed in organoids from patients with the 16p11.2 deletion syndrome and thus identified a novel link between independent CNVs associated with neuronal development and autism. Overall, this work suggests convergent signaling, which indicates the possibility of a common therapeutic mechanism across multiple rare neuronal diseases.

Association of Screen Time with Anxiety and Depressive Symptoms in College Students During COVID-19 Outbreak in Shanghai: Mediation Role of Sleep Quality.

The study aimed to investigate the associations between different types of screen time (ST) and anxiety and depressive symptoms in college students during the Coronavirus disease 2019 (COVID-19) outbreak in Shanghai, China; the potential mediation role of sleep quality was also examined. A total of 1,550 college students completed an online survey in May 2022. ST, Self-rating Anxiety Scale (SAS) score, Self-rating Depression Scale (SDS) score, Pittsburgh Sleep Quality Index (PSQI) score, and physical activity were self-reported. Multiple linear regression and mediation analysis were conducted. The results showed that more time spent in TV/movie viewing (>2 h/day) and recreational reading (>1 h/day) was associated with higher levels of anxiety, while more time spent in online social media (>2 h/day) was associated with a higher level of depressive symptoms. In contrast, time spent in online social media (1-2 h/day) was associated with a lower level of anxiety. Meanwhile, recreational reading (2-3 h/day) had a significant indirect effect on anxiety and depressive symptoms through sleep quality. During the COVID-19 outbreak, the associations of ST with anxiety and depressive symptoms varied by the type of screen viewing in college students. The associations of slightly excessive time spent on recreational reading with higher levels of anxiety and depressive symptoms were partially mediated by sleep quality.

Improvement in Mechanical Properties of Al2024 Alloy Using Mechanical Working and Heat Treatment.

Extrusion speed has a significant influence on the extrusion temperature, microstructure and mechanical properties of the material in the repetitive continuous extrusion forming (RCEF) process. In this work, the mechanical properties of Al2024 were improved by adjusting the speed (with a general range of 2-10 rpm) of repetitive continuous extrusion and applying subsequent heat treatment. During the RCEF process, an increase in the extrusion speed from 4 to 8 rpm was found to increase the extrusion temperature and then enhance the solid solution function. The grain size was affected by the combined effect of deformation speed and its induced temperature. A high-strength Al2024 (ultimate tensile strength of 497.6 MPa) with good elongation (12.93%) was obtained by increasing the extrusion speed and conducting solid solution and artificial aging treatments. The main strengthening mechanisms could be attributed to finer grain size and a larger amount of S (Al2CuMg) precipitates.

Diagnostic value of dynamic 18F-FDG PET/CT imaging in non-small cell lung cancer and FDG hypermetabolic lymph nodes.

Background: We aimed to investigate the diagnostic value of dynamic 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography-computed tomography in non-small cell lung cancer and fluoro-D-glucose hypermetabolic lymph nodes. Methods: Patients who made an active appointment for positron emission tomography-computed tomography were randomly enrolled by referring to previous imaging data and clinical information. Finally, 34 histopathologically confirmed non-small cell lung cancers (18 adenocarcinoma and 16 squamous cell carcinoma cases) were prospectively studied using dynamic and static 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography-computed tomography imaging (the diagnostic study has not yet been registered on a clinical trial platform). In dynamic positron emission tomography images, a volume of interest, defined by the thoracic aorta, was selected for estimating the arterial input function. Patlak and irreversible two-tissue compartment model analyses were performed based on the pixel points to obtain first-order characteristic kinetic parameters for each lesion and hypermetabolic lymph node. The first-order characteristic kinetic parameters were obtained based on the basic data of dynamic positron emission tomography images in the corresponding model and the lesion delineation of region-of-interest based on computed tomography images, such as V_Median (the median gray intensity of V), k3_Entropy, VB_Entropy, K1_Uniformity, and ki_Uniformity. The first-order characteristic kinetic parameters were also modeled by logistic regression for the differential diagnosis of non-small cell lung cancer and hypermetabolic lymph nodes. Maximum and mean standard uptake values (SUVmax and SUVmean, respectively) were obtained from static positron emission tomography images. The diagnostic efficacy of the parameters was evaluated using the receiver operating characteristic curve and the DeLong test. Results: There was a significant difference in the V_Median values of adenocarcinoma and squamous cell carcinoma. The regression models for K1, k3, and V provided good predictions of adenocarcinoma and squamous cell carcinoma typology. Significant differences were observed in k3_Entropy, VB_Entropy, K1_Uniformity, and ki_Uniformity between benign and malignant lymph nodes. The regression model of Ki, VB, and k3 could make a good prediction for identifying benign and malignant lymph nodes. Conclusions: Dynamic 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography-computed tomography imaging showed high diagnostic value in the staging of non-small cell lung cancer and fluoro-D-glucose hypermetabolic lymph nodes, and can be of great use in non-small cell lung cancer lymph node staging and surgical decision-making.

Synthesis of Unprecedented α/ß-Alternate (1→4)-Glucans via Stereoselective Iterative Glycosylation.

Glucans are major biomaterials on the earth, with α-(1→4)-glucans (i. e., amylose) and ß-(1→4)-glucans (i. e., cellulose) being the most abundant ones, which are relevant to energy storage and structural function, respectively. Interestingly, (1→4)-glucans with alternate α/ß-linkages, namely herewith amycellulose, have never been disclosed in nature. Here we report a robust glycosylation protocol for the stereoselective construction of the 1,2-cis-α- and 1,2-trans-ß-glucosidic linkages, which employs an optimal combination of glycosyl N-phenyltrifluoroacetimidates as donors, TMSNTf2 as promoter, CH2 Cl2 /nitrile or CH2 Cl2 /THF as solvents. A broad substrate scope has been demonstrated by coupling five imidate donors with eight glycosyl acceptors, in which most of the glycosylations lead to high yield and exclusively 1,2-cis-α- or 1,2-trans-ß-selectivity. Applying this glycosylation protocol and with an iterative manner, the unprecedented α/ß-alternate (1→4)-glucans up to a 16-mer have been synthesized. Differently from amylose, that adopts a compact helicoidal arrangement, the synthetic amycellulose features an extended ribbon-like conformation, comparable to the extended shape of cellulose.

Identification of miR-192 target genes in porcine endometrial epithelial cells based on miRNA pull-down.

INTRODUCTION: MicroRNAs (miRNAs)-a class of small endogenous non-coding RNAs-are widely involved in post-transcriptional gene regulation of numerous physiological processes. High-throughput sequencing revealed that the miR-192 expression level appeared to be significantly higher in the blood exosomes of sows at early gestation than that in non-pregnant sows. Furthermore, miR-192 was hypothesized to have a regulatory role in embryo implantation; however, the target genes involved in exerting the regulatory function of miR-192 required further elucidation. METHODS: In the present study, potential target genes of miR-192 in porcine endometrial epithelial cells (PEECs) were identified through biotin-labeled miRNA pull-down; functional and pathway enrichment analysis was performed via gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. Bioinformatic analyses were concurrently used to predict the potential target genes associated with sow embryo implantation. In addition, double luciferase reporter vectors, reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and Western blot were performed to verify the targeting and regulatory roles of the abovementioned target genes. RESULTS: A total of 1688 differentially expressed mRNAs were identified via miRNA pull-down. Through RT-qPCR, the accuracy of the sequencing data was verified. In the bioinformatics analysis, potential target genes of miR-192 appeared to form a dense inter-regulatory network and regulated multiple signaling pathways, such as metabolic pathways and the PI3K-Akt, MAPKs, and mTOR signaling pathways, that are relevant to the mammalian embryo implantation process. In addition, CSK (C-terminal Src kinase) and YY1 (Yin-Yang-1) were predicted to be potential candidates, and we validated that miR-192 directly targets and suppresses the expression of the CSK and YY1 genes. CONCLUSION: We screened 1688 potential target genes of miR-192 were screened, and CSK and YY1 were identified as miR-192 target genes. The outcomes of the present study provide novel insights into the regulatory mechanism of porcine embryo implantation and the identification of miRNA target genes.

Retrieval of Leaf Chlorophyll Contents (LCCs) in Litchi Based on Fractional Order Derivatives and VCPA-GA-ML Algorithms.

The accurate estimation of leaf chlorophyll content (LCC) is a significant foundation in assessing litchi photosynthetic activity and possible nutrient status. Hyperspectral remote sensing data have been widely used in agricultural quantitative monitoring research for the non-destructive assessment of LCC. Variable selection approaches are crucial for analyzing high-dimensional datasets due to the high danger of overfitting, time-intensiveness, or substantial computational requirements. In this study, the performance of five machine learning regression algorithms (MLRAs) was investigated based on the hyperspectral fractional order derivative (FOD) reflection of 298 leaves together with the variable combination population analysis (VCPA)-genetic algorithm (GA) hybrid strategy in estimating the LCC of Litchi. The results showed that the correlation coefficient (r) between the 0.8-order derivative spectrum and LCC had the highest correlation coefficients (r = 0.9179, p < 0.01). The VCPA-GA hybrid strategy fully utilizes VCPA and GA while compensating for their limitations based on a large number of variables. Moreover, the model was developed using the selected 14 sensitive bands from 0.8-order hyperspectral reflectance data with the lowest root mean square error in prediction (RMSEP = 5.04 µg·cm-2). Compared with the five MLRAs, validation results confirmed that the ridge regression (RR) algorithm derived from the 0.2 order was the most effective for estimating the LCC with the coefficient of determination (R2 = 0.88), mean absolute error (MAE = 3.40 µg·cm-2), root mean square error (RMSE = 4.23 µg·cm-2), and ratio of performance to inter-quartile distance (RPIQ = 3.59). This study indicates that a hybrid variable selection strategy (VCPA-GA) and MLRAs are very effective in retrieving the LCC through hyperspectral reflectance at the leaf scale. The proposed methods could further provide some scientific basis for the hyperspectral remote sensing band setting of different platforms, such as an unmanned aerial vehicle (UAV) and satellite.

Coupled retrieval of heavy metal nickel concentration in agricultural soil from spaceborne hyperspectral imagery.

Widespread soil contamination endangers public health and undermines global attempts to achieve the United Nations Sustainable Development Goals. Due to the lack of relevant studies and low precision of spaceborne spectroscopy, estimating soil heavy metal concentrations is challenging. In this study, we developed a coupled retrieval to qualify the heavy metal nickel (Ni) concentration in agricultural soil from spaceborne hyperspectral imagery. The retrieval couples spectral feature extraction from multi-scale discrete wavelet transform (DWT) and dimension reduction (DR), optimal band combination algorithm to five machine learning retrieval models using tree-based ensemble learning, neural network-based, and kernel-based. The comparison between the retrievals and Ni measurements shows that the DWT combined with t-distributed stochastic neighbor embedding (tSNE) coupled extreme gradient boosting (XGboost) retrieval model exhibited the best prediction for the validation dataset. Moreover, due to the integration of six statistical indicators of model performance and the fitted slope of the regression line, the retrieval framework can produce more robust and accurate predictions than those that rely on correlation coefficients. The demonstrated potential of spaceborne hyperspectral remote sensing to provide accurate quantitative measurements of soil heavy metal concentrations will serve as a reference for agricultural plot applications worldwide.

Chelator Iminodisuccinic Acid Regulates Reactive Oxygen Species Accumulation and Improves Maize (Zea mays L.) Seed Germination under Pb Stress.

To explore the effects of iminodisuccinic acid (a chelating agent) on maize (Zea mays L.) seed germination under lead (Pb) stress, we comparatively analyzed the effects of applying different concentrations of iminodisuccinic acid (0, 5, 20, and 100 mmol·dm-3) and combined an addition of exogenous substances regulating reactive oxygen species production on maize seed germination, seedling growth, H2O2 content, NADPH oxidase activity, and antioxidant enzyme activities under Pb-stressed and Pb-free conditions. Iminodisuccinic acid (100 mmol·dm-3) significantly delayed seed germination under normal germination conditions and alleviated the inhibitory effects of Pb stress (20 mmol·dm-3) on seed germination. Under normal conditions (without Pb stress), the iminodisuccinic acid-induced inhibition of seed germination was enhanced by treatment with dimethylthiourea (a specific scavenger of reactive oxygen species) or diphenyleneiodonium chloride (a specific inhibitor of NADPH oxidase), but diminished by treatment with H2O2, CaCl2, diethyldithiocarbamic acid (a specific inhibitor of superoxide dismutase), or aminotriazole (a specific inhibitor of catalase). Under Pb stress, iminodisuccinic acid partially eliminated the excessive H2O2 accumulation, improved superoxide dismutase and catalase activity, and weakened the high NADPH oxidase activity. In addition, Ca2+ chelation may be essential for maintaining the reactive oxygen species' balance and improving seed germination and seedling growth by iminodisuccinic acid supplementation in maize under Pb stress. The proposed iminodisuccinic acid supplementation-based method improved maize seed germination in Pb-polluted soil.

Chiral DNA Nanotubes Self-Assembled from Building Blocks with Tailorable Curvature and Twist.

DNA nanotubes with prescribed geometry could allow for nanomaterial organization with designed optical or electrical function. As one of the dominating driving forces for DNA nanotube assembly, intrinsic curvature and twist of building blocks can be induced by bending deformation and twisting deformation. However, it is still unknown that how bending and twisting design on nanoscale building blocks affects the geometry of DNA tubes with micrometer length. Here, through targeted base pair deletion or insertion, the amount of bending deformation in building blocks is modulated by length gradient and the amount of twisting deformation is modulated by average twist density. This work systematically explores the independent effect and synergistic effect of two types of deformation on tube geometry, including diameter, chirality, and helical angles, via a streptavidin-labeling technique. The design rules enable the construction of DNA nanotubes with prescribed chirality and tailored diameters.

Novel Biphasically and Reversibly Transparent Phase Change Material to Solve the Thermal Issues in Transparent Electronics.

Highly integrated transparent electronic systems are experiencing significant thermal bottlenecks due to the rapid growth of transparent electronics and the lack of suitable transparent thermal management solutions. Therefore, transparent thermal management materials are highly desirable in modern transparent electronics. Based on the phase change properties of polyethylene glycol (PEG) and the encapsulable properties of epoxy resin (EP), we synthesize a biphasically and reversibly transparent PEG/EP composite for thermal energy storage (TPE-TES). Energy-driven structural rearrangements in cross-linked networks are responsible for the high transparency with practical thickness. According to SEM and TEM investigations, PEG and EP achieve submicron phase dispersion, while TPE-TES forms a smooth and continuous surface that suppresses diffuse reflections and contributes to improved visible light penetration. The unique combination of phase change and optical transparency gives TPE-TES the ability to regulate thermal storage, rapid temperature change, and spatial temperature uniformity of transparent electronics. Due to its flexibility, stability, and processability, TPE-TES is also suitable and ideal as thin surface coating films or thick transparent flexible substrates for a wide range of applications in the integration of electronic devices.

Transcriptome analysis reveals that long noncoding RNAs contribute to developmental differences between medium-sized ovarian follicles of Meishan and Duroc sows.

Ovulation rate is an extremely important factor affecting litter size in sows. It differs greatly among pig breeds with different genetic backgrounds. Long non-coding RNAs (lncRNAs) can regulate follicle development, granulosa cell growth, and hormone secretion, which in turn can affect sow litter size. In this study, we identified 3554 lncRNAs and 25,491 mRNAs in M2 follicles of Meishan and Duroc sows. The lncRNA sequence and open reading frame lengths were shorter than mRNAs, and lncRNAs had fewer exons, were less abundant, and more conserved than protein-coding RNAs. Furthermore, 201 lncRNAs were differentially expressed (DE) between breeds, and quantitative trait loci analysis of DE lncRNAs were performed. A total of 127 DE lncRNAs were identified in 119 reproduction trait-related loci. In addition, the potential target genes of lncRNAs in cis or trans configurations were predicted. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that some potential target genes were involved in follicular development and hormone secretion-related biological processes or pathways, such as progesterone biosynthetic process, estrogen metabolic process, ovarian steroidogenesis, and PI3K-Akt signaling pathway. Furthermore, we also screened 19 differentially expressed lncRNAs in the PI3K-Akt signaling pathway as candidates. This study provides new insights into the roles of lncRNAs in follicular growth and development in pigs.

Identification of differentially expressed miRNAs in serum extracellular vesicles (EVs) of Kazakh sheep at early pregnancy.

MiRNAs-containing extracellular vesicles (EVs) possess the unique function of mediating intercellular communication and participating in many biological processes such as post-transcriptional gene regulation of embryo implantation and placental development. In the present study, Illumina small-RNA sequencing was used to identify differentially expressed (DE) miRNAs in serum EVs of pregnant (P) and non-pregnant (NP) Kazakh sheep at Day 17 from mating. The specifically and differentially expressed miRNAs at early pregnancy in sheep were verified by using RT-PCR. The target genes of DE miRNAs were predicted by bioinformatics software, and the functional and pathway enrichment analysis was performed on Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) terms. A total of 562 miRNAs (210 novel miRNAs) were identified by sequencing, of which 57 miRNAs were differentially expressed, 49 were up-regulated, 8 were down-regulated and 22 novel miRNAs were specifically expressed in the pregnant sheep. Eight highly expressed known miRNA (miR-378-3p, miR-320-3p, miR-22-3p, let-7b, miR-423-3p, miR-221, miR-296-3p, miR-147-3p) in pregnant group were down-regulated in the control group. miRNAs-containing pregnancy-related terms and regulatory pathways regulation were enriched using both GO and KEGG analyses. Moreover, we also envisioned a miRNA-mRNA interaction network to understand the function of miRNAs involved in the early pregnancy serum regulatory network. The results of RT-PCR verification confirmed the reliability of small-RNA sequencing. Among them, miR-22-3p and miR-378-3p were significantly differentially expressed (DE) between pregnant sheep and non-pregnant group (p <  0.01). The site at which oar-miR-22-3p binds MAPK3 was determined with a dual-luciferase system. This is the first integrated analysis of the expression profiles of EV-miRNAs and their targets during early pregnancy in ewes. These data identify key miRNAs that influence the implantation of sheep in the early stage of pregnancy, and provide theoretical basis for further molecular regulatory mechanisms research.

Neuronal defects in a human cellular model of 22q11.2 deletion syndrome.

22q11.2 deletion syndrome (22q11DS) is a highly penetrant and common genetic cause of neuropsychiatric disease. Here we generated induced pluripotent stem cells from 15 individuals with 22q11DS and 15 control individuals and differentiated them into three-dimensional (3D) cerebral cortical organoids. Transcriptional profiling across 100 days showed high reliability of differentiation and revealed changes in neuronal excitability-related genes. Using electrophysiology and live imaging, we identified defects in spontaneous neuronal activity and calcium signaling in both organoid- and 2D-derived cortical neurons. The calcium deficit was related to resting membrane potential changes that led to abnormal inactivation of voltage-gated calcium channels. Heterozygous loss of DGCR8 recapitulated the excitability and calcium phenotypes and its overexpression rescued these defects. Moreover, the 22q11DS calcium abnormality could also be restored by application of antipsychotics. Taken together, our study illustrates how stem cell derived models can be used to uncover and rescue cellular phenotypes associated with genetic forms of neuropsychiatric disease.

Identification of circular RNAs in the ovarian follicles of Meishan and Duroc sows during the follicular phase.

Circular RNAs (circRNAs) are a newly discovered class of endogenous non-coding RNAs that play an important role in growth and development by regulating gene expression and participating in a variety of biological processes. However, the role of circRNAs in porcine follicles remains unclear. Therefore, this study examined middle-sized ovarian follicles obtained from Meishan and Duroc sows at day 4 of the follicular phase. High-throughput RNA sequencing (RNA-seq) was utilized to construct circRNAs, and differential expression was identified. The findings were validated using reverse transcription PCR (RT-PCR) and DNA sequencing, GO and KEGG analyses were performed, and potential miRNA targets were identified. The RNA-seq identified a total of 15,866 circRNAs, with 244 differentially expressed in the Meishan relative to the Duroc (111 up-regulated and 133 down-regulated). The RT-PCR finding confirmed the RNA-seq results, and quantitative real-time PCR (qPCR) analysis examining a subset of the circRNAs showed that they are resistant to RNase R digestion. Bioinformatics analysis (GO and KEGG) showed that the host genes associated with the differentially expressed circRNAs are involved in reproduction and follicular development signaling pathways. Furthermore, many of the circRNAs were found to interact with miRNAs that are associated with follicular development. This study presents a new perspective for studying circRNAs and provides a valuable resource for further examination into the potential roles of circRNAs in porcine follicular development.

Structure-Activity Relationship Evaluation of Wasp Toxin ß-PMTX Leads to Analogs with Superior Activity for Human Neuronal Sodium Channels.

Beta-pompilidotoxin (ß-PMTX) is a 13-amino acid wasp venom peptide that activates human neuronal sodium channel NaV1.1 with weak activity (40% activation at 3.3 µM of ß-PMTX). Through rational design of ß-PMTX analogs, we have identified peptides with significantly improved activity on human NaV1.1 (1170% activation at 3.3 µM of peptide 18). The underlying structure-activity relationship suggests importance of charge interactions (from residue Lys-3) and lipophilic interactions (from residue Phe-7 and Ser-11). Three top-ranked analogs showed parallel activity improvement for other neuronal sodium channels (human NaV1.2/1.3/1.6/1.7) but not muscular subtypes (NaV1.4/1.5). Finally, we found that analog 16 could partially rescue the pharmacological block imposed by NaV1.1/1.3 selective inhibitor ICA-121431 in cultured mouse cortical GABAergic neurons, demonstrating an activating effect of this peptide on native neuronal sodium channels and its potential utility as a neuropharmacological tool.

Investigating the Therapeutic Mechanism of Cannabidiol in a Human Induced Pluripotent Stem Cell (iPSC)-Based Model of Dravet Syndrome.

Dravet syndrome is an infantile epileptic encephalopathy primarily caused by loss-of-function variants of the gene SCN1A Standard treatment regimens have very limited efficacy to combat the life-threatening seizures in Dravet syndrome or the behavioral-cognitive comorbidities of the disease. Recently there has been encouraging progress in developing new treatments for this disorder. One of the clinical advances is cannabidiol (CBD), a compound naturally found in cannabis and shown to further reduce convulsive seizures in patients when used together with existing drug regimens. Like many other natural products, the exact therapeutic mechanism of CBD remains undefined. Previously we have established a human cellular model of Dravet syndrome by differentiating patient-derived induced pluripotent stem cells (iPSCs) into telencephalic inhibitory and excitatory neurons. Here we have applied this model to investigate the antiepileptic mechanism(s) of CBD at the cellular level. We first determined the effect of escalating the concentrations of CBD on neuronal excitability, using primary culture of rat cortical neurons. We found modulatory effects on excitability at submicromolar concentrations and toxic effects at high concentrations (15 µM). We then tested CBD at 50 nM, a concentration that corresponds to the estimated human clinical exposure, in telencephalic neurons derived from a patient iPSC line and control cell line H9. This 50 nM of CBD increased the excitability of inhibitory neurons but decreased the excitability of excitatory neurons, without changing the amplitude of sodium currents in either cell type. Our findings suggest a cell type-dependent mechanism for the therapeutic action of CBD in Dravet syndrome that is independent of sodium channel activity.