Atmospheric forcing dominates winter Barents-Kara sea ice variability on interannual to decadal time scales.

The last two decades have seen a dramatic decline and strong year-to-year variability in Arctic winter sea ice, especially in the Barents-Kara Sea (BKS), changes that have been linked to extreme midlatitude weather and climate. It has been suggested that these changes in winter sea ice arise largely from a combined effect of oceanic and atmospheric processes, but the relative importance of these processes is not well established. Here, we explore the role of atmospheric circulation patterns on BKS winter sea ice variability and trends using observations and climate model simulations. We find that BKS winter sea ice variability is primarily driven by a strong anticyclonic anomaly over the region, which explains more than 50% of the interannual variability in BKS sea-ice concentration (SIC). Recent intensification of the anticyclonic anomaly has warmed and moistened the lower atmosphere in the BKS by poleward transport of moist-static energy and local processes, resulting in an increase in downwelling longwave radiation. Our results demonstrate that the observed BKS winter sea-ice variability is primarily driven by atmospheric, rather than oceanic, processes and suggest a persistent role of atmospheric forcing in future Arctic winter sea ice loss.

Preparation and application of fluorescent monoclonal antibodies recognizing goat CD4+CD25+ regulatory T cells.

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats. KEY POINTS: • A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs. • C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity. • The frequency of Treg cells was positively correlated with the viral load during orf virus infection.

Two populations of self-maintaining monocyte-independent macrophages exist in adult epididymis and testis.

Macrophages are the principal immune cells of the epididymis and testis, but their origins, heterogeneity, development, and maintenance are not well understood. Here, we describe distinct populations of epididymal and testicular macrophages that display an organ-specific cellular identity. Combining in vivo fate-mapping, chimeric and parabiotic mouse models with in-depth cellular analyses, we found that CD64hiMHCIIlo and CD64loMHCIIhi macrophage populations of epididymis and testis arise sequentially from yolk sac erythro-myeloid progenitors, embryonic hematopoiesis, and nascent neonatal monocytes. While monocytes were the major developmental source of both epididymal and testicular macrophages, both populations self-maintain in the steady-state independent of bone marrow hematopoietic precursors. However, after radiation-induced macrophage ablation or during infection, bone marrow-derived circulating monocytes are recruited to the epididymis and testis, giving rise to inflammatory macrophages that promote tissue damage. These results define the layered ontogeny, maintenance and inflammatory response of macrophage populations in the male reproductive organs.

The suppression of hyperlipid diet-induced ferroptosis of vascular smooth muscle cells protests against atherosclerosis independent of p53/SCL7A11/GPX4 axis.

Ferroptosis as a novel programmed cell death that involves metabolic dysfunction due to iron-dependent excessive lipid peroxidation has been implicated in atherosclerosis (AS) development characterized by disrupted lipid metabolism, but the atherogenic role of ferroptosis in vascular smooth muscle cells (VSMCs), which are principal components of atherosclerotic plaque fibrous cap, remains unclear. The aim of this study was to determine the effects of ferroptosis on AS induced by lipid overload, and the effects of that on VSMCs ferroptosis. We found intraperitoneal injection of Fer-1, a ferroptosis inhibitor, ameliorated obviously high-fat diet-induced high plasma levels of triglycerides, total cholesterol, low-density lipoprotein, glucose and atherosclerotic lesions in ApoE-/- mice. Moreover, in vivo and in vitro, Fer-1 reduced the iron accumulation of atherosclerotic lesions through affecting the expression of TFR1, FTH, and FTL in VSMCs. Interestingly, Fer-1 did augment nuclear factor E2-related factor 2/ferroptosis suppressor protein 1 to enhance endogenous resistance to lipid peroxidation, but not classic p53/SCL7A11/GPX4. Those observations indicated inhibition of VSMCs ferroptosis can improve AS lesions independent of p53/SLC7A11/GPX4, which preliminarily revealed the potential mechanism of ferroptosis in aortic VSMCs on AS and provided new therapeutic strategies and targets for AS.

Convergent Adaptation of Ootheca Formation as a Reproductive Strategy in Polyneoptera.

Insects have evolved numerous adaptations and colonized diverse terrestrial environments. Several polyneopterans, including dictyopterans (cockroaches and mantids) and locusts, have developed oothecae, but little is known about the molecular mechanism, physiological function, and evolutionary significance of ootheca formation. Here, we demonstrate that the cockroach asymmetric colleterial glands produce vitellogenins, proline-rich protein, and glycine-rich protein as major ootheca structural proteins (OSPs) that undergo sclerotization and melanization for ootheca formation through the cooperative protocatechuic acid pathway and dopachrome and dopaminechrome subpathway. Functionally, OSP sclerotization and melanization prevent eggs from losing water at warm and dry conditions, and thus effectively maintain embryo viability. Dictyopterans and locusts convergently evolved vitellogenins, apolipoprotein D, and laminins as OSPs, whereas within Dictyoptera, cockroaches and mantids independently developed glycine-rich protein and fibroins as OSPs. Highlighting the ecological-evolutionary importance, convergent ootheca formation represents a successful reproductive strategy in Polyneoptera that promoted the radiation and establishment of cockroaches, mantids, and locusts.

Gut microbiota regulate migration of lymphocytes from gut to lung.

The community of microorganisms known as gut microbiota that lives in the intestine confers significant health benefits on its host, primarily in the form of immunological homeostasis regulation. Gut microbiota not only can shape immune responses in the gut but also in other organs. This review focus on the gut-lung axis. Aberrant gut microbiota development is associated with greater lung disease susceptibility and respiratory disease induced by a variety of pathogenic bacteria. They are known to cause changes in gut microbiota. Recent research has found that immune cells in the intestine migrate to distant lung to exert anti-infective effects. Moreover, evidence indicates that the gut microbiota and their metabolites influence intestinal immune cells. Therefore, we suspect that intestine-derived immune cells may play a significant role against pulmonary pathogenic infections by receiving instructions from gut microbiota.

Natural ocean iron fertilization and climate variability over geological periods.

Marine primary producers are largely dependent on and shape the Earth's climate, although their relationship with climate varies over space and time. The growth of phytoplankton and associated marine primary productivity in most of the modern global ocean is limited by the supply of nutrients, including the micronutrient iron. The addition of iron via episodic and frequent events drives the biological carbon pump and promotes the sequestration of atmospheric carbon dioxide (CO2 ) into the ocean. However, the dependence between iron and marine primary producers adaptively changes over different geological periods due to the variation in global climate and environment. In this review, we examined the role and importance of iron in modulating marine primary production during some specific geological periods, that is, the Great Oxidation Event (GOE) during the Huronian glaciation, the Snowball Earth Event during the Cryogenian, the glacial-interglacial cycles during the Pleistocene, and the period from the last glacial maximum to the late Holocene. Only the change trend of iron bioavailability and climate in the glacial-interglacial cycles is consistent with the Iron Hypothesis. During the GOE and the Snowball Earth periods, although the bioavailability of iron in the ocean and the climate changed dramatically, the changing trend of many factors contradicted the Iron Hypothesis. By detangling the relationship among marine primary productivity, iron availability and oceanic environments in different geological periods, this review can offer some new insights for evaluating the impact of ocean iron fertilization on removing CO2 from the atmosphere and regulating the climate.

Egfr signaling promotes juvenile hormone biosynthesis in the German cockroach.

BACKGROUND: In insects, an interplay between the activities of distinct hormones, such as juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulates the progression through numerous life history hallmarks. As a crucial endocrine factor, JH is mainly synthesized in the corpora allata (CA) to regulate multiple physiological and developmental processes, including molting, metamorphosis, and reproduction. During the last century, significant progress has been achieved in elucidating the JH signal transduction pathway, while less progress has been made in dissecting the regulatory mechanism of JH biosynthesis. Previous work has shown that receptor tyrosine kinase (RTK) signaling regulates hormone biosynthesis in both insects and mammals. Here, we performed a systematic RNA interference (RNAi) screening to identify RTKs involved in regulating JH biosynthesis in the CA of adult Blattella germanica females. RESULTS: We found that the epidermal growth factor receptor (Egfr) is required for promoting JH biosynthesis in the CA of adult females. The Egf ligands Vein and Spitz activate Egfr, followed by Ras/Raf/ERK signaling, and finally activation of the downstream transcription factor Pointed (Pnt). Importantly, Pnt induces the transcriptional expression of two key enzyme-encoding genes in the JH biosynthesis pathway: juvenile hormone acid methyltransferase (JHAMT) and methyl farnesoate epoxidase (CYP15A1). Dual-luciferase reporter assay shows that Pnt is able to activate a promoter region of Jhamt. In addition, electrophoretic mobility shift assay confirms that Pnt directly binds to the - 941~ - 886 nt region of the Jhamt promoter. CONCLUSIONS: This study reveals the detailed molecular mechanism of Egfr signaling in promoting JH biosynthesis in the German cockroach, shedding light on the intricate regulation of JH biosynthesis during insect development.

Time-resolved fluorescence microspheres-antibody-penicillin-binding protein assisted construction of immunochromatographic assay for sensitive detection of 22 ß-lactams in milk.

A sensitive immunochromatographic assay (ICA) using time-resolved fluorescence microspheres (TRFMs) coupled with an indirect-labeling mode was developed for simultaneously determining 22 kinds of ß-lactams in milk samples. The TRFMs labeled anti-receptor monoclonal antibodies (mAbs) conjugated to penicillin-binding proteins (PBPs) as ternary TRFMs-mAb-PBPs (TMP) nanoscaffolds provide excellent solubility, brightness, and stability. Thanks to the fact that they not only fully expose the binding sites of PBPs, thereby enhancing the biological affinity of PBPs towards the target, but also generated superb fluorescence signals, the versatile TMP manifested unique possibilities as efficient probes for ICA with remarkable enhancement in sensitivity in ß-lactams screening. The results showed that the standard curves of the 22 varying ß-lactams displayed linearity in their respective concentration ranges (R2 > 0.98), with the cutoff values of 1-100 ng/mL. The constructed TMP-ICA was successfully applied to the analysis of real milk, with consistent results compared with liquid chromatography-tandem mass spectrometry (LC-MS), providing an effective method for sensing ß-lactams in food matrices.

A New Efficient Multi-Object Detection and Size Calculation for Blended Tobacco Shreds Using an Improved YOLOv7 Network and LWC Algorithm.

Detection of the four tobacco shred varieties and the subsequent unbroken tobacco shred rate are the primary tasks in cigarette inspection lines. It is especially critical to identify both single and overlapped tobacco shreds at one time, that is, fast blended tobacco shred detection based on multiple targets. However, it is difficult to classify tiny single tobacco shreds with complex morphological characteristics, not to mention classifying tobacco shreds with 24 types of overlap, posing significant difficulties for machine vision-based blended tobacco shred multi-object detection and unbroken tobacco shred rate calculation tasks. This study focuses on the two challenges of identifying blended tobacco shreds and calculating the unbroken tobacco shred rate. In this paper, a new multi-object detection model is developed for blended tobacco shred images based on an improved YOLOv7-tiny model. YOLOv7-tiny is used as the multi-object detection network's mainframe. A lightweight Resnet19 is used as the model backbone. The original SPPCSPC and coupled detection head are replaced with a new spatial pyramid SPPFCSPC and a decoupled joint detection head, respectively. An algorithm for two-dimensional size calculation of blended tobacco shreds (LWC) is also proposed, which is applied to blended tobacco shred object detection images to obtain independent tobacco shred objects and calculate the unbroken tobacco shred rate. The experimental results showed that the final detection precision, mAP@.5, mAP@.5:.95, and testing time were 0.883, 0.932, 0.795, and 4.12 ms, respectively. The average length and width detection accuracy of the blended tobacco shred samples were -1.7% and 13.2%, respectively. The model achieved high multi-object detection accuracy and 2D size calculation accuracy, which also conformed to the manual inspection process in the field. This study provides a new efficient implementation method for multi-object detection and size calculation of blended tobacco shreds in cigarette quality inspection lines and a new approach for other similar blended image multi-object detection tasks.

Focus on ferroptosis, pyroptosis, apoptosis and autophagy of vascular endothelial cells to the strategic targets for the treatment of atherosclerosis.

Vascular endothelial cells (VECs), which are lined up in the inner surface of blood vessels, are in direct contact with the metabolite-related endogenous danger signals in the circulatory system. Moreover, VECs death impairs vasodilation and increases endothelium-dependent permeability, which is strongly correlated with the development of atherosclerosis (AS). Among several forms of cell death, regulatory death of endothelial cells frequently occurs in AS, mainly including ferroptosis, pyroptosis, apoptosis and autophagy. In this review, we summarize regulatory factors and signaling mechanisms of regulatory death in endothelial cells, discussing their effects in the context of the atherosclerotic procession.

The automatic parameter-exploration with a machine-learning-like approach: Powering the evolutionary modeling on the origin of life.

The origin of life involved complicated evolutionary processes. Computer modeling is a promising way to reveal relevant mechanisms. However, due to the limitation of our knowledge on prebiotic chemistry, it is usually difficult to justify parameter-setting for the modeling. Thus, typically, the studies were conducted in a reverse way: the parameter-space was explored to find those parameter values "supporting" a hypothetical scene (that is, leaving the parameter-justification a later job when sufficient knowledge is available). Exploring the parameter-space manually is an arduous job (especially when the modeling becomes complicated) and additionally, difficult to characterize as regular "Methods" in a paper. Here we show that a machine-learning-like approach may be adopted, automatically optimizing the parameters. With this efficient parameter-exploring approach, the evolutionary modeling on the origin of life would become much more powerful. In particular, based on this, it is expected that more near-reality (complex) models could be introduced, and thereby theoretical research would be more tightly associated with experimental investigation in this field-hopefully leading to significant steps forward in respect to our understanding on the origin of life.

A bioinspired, electroactive colorable and additive manufactured photonic artificial muscle.

Structural coloration in biomimetic nanostructures has remarkable application potential in vivid display devices, but their color change effect is still insufficiently competitive towards biology. Inspired by the feather color change of a hummingbird, a new methodology for coloration is proposed. A structure-colorable flexural artificial muscle (FlexAM) is developed by integrating a view-angle dependent photonic diffraction grating pattern and voltage-actuated dielectric elastomers as an electroactive entity via laminated object additive manufacturing. A multi-physics model is developed which guides the FlexAM to harness the view-angle dependence for the new coloration strategy. The electro-mechanochromic performances are experimentally characterized to verify the prediction of the multi-physics model. An ultrafast coloration in the FlexAM with an advancing figure-of-merit at a color-shift rate of 2.814 nm ms-1 is realized, in addition to an excellent fatigue resistance up to 10 000 cycles. A photonic display with arrayed FlexAM elements is designed, which can be used to display numbers and letters. The current research offers an advanced artificial muscle towards active photonic and visible strain sensing.

Heparin-free after 3000 IU heparin loaded in veno-venous ECMO supported acute respiratory failure patients with hemorrhage risk: a novel anti-coagulation strategy.

BACKGROUND: The anti-coagulation protocol of patients with hemorrhage risk primary disease who need extracorporeal membrane oxygenation (ECMO) supported is controversial. This study evaluated the feasibility of a new anti-coagulation strategy, that is heparin-free after 3000 IU heparin loaded in veno-venous ECMO (VV ECMO) supported acute respiratory failure patients with hemorrhage risk. METHODS: A retrospective study was performed in a series of hemorrhage risk patients supported with VV ECMO at the First Affiliated Hospital of Zhengzhou University, between June 2012 to Sept 2020. A total of 70 patients received a low heparin bolus of 3000 units for cannulation but without subsequent, ongoing heparin administration. Patients were divided into survival (n = 25) and non-survival group (n = 45). Data of coagulation, hemolysis and membrane lung function were calculated and analyzed. The complications of patients were recorded. Finally, the binary Logistic regression was conducted. RESULTS: The longest heparin-free time was 216 h, and the mean heparin-free time was 102 h. Compared with survivors, the non-survivors were showed higher baseline SOFA score and lower platelet counts in 0.5 h, 24 h, 48 h and 96 h after ECMO applied. However, there was no significant differences between survivors and non-survivors in ACT, APTT, INR, D-dimer, fibrinogen, LDH, blood flow rate, Δp and Ppost-MLO2 (all p < 0.05) of all different time point. Moreover, only the baseline SOFA score was significantly associated with mortality (p < 0.001, OR(95%CI): 2.754 (1.486-5.103)) while the baseline levels of ACT, APTT, INR, platelet, D-dimer, fibrinogen and LDH have no association with mortality. The percentage of thrombosis complications was 54.3% (38/70) including 3 oxygenator changed but there was no significant difference of complications in survival and non-survival groups (p > 0.05). CONCLUSIONS: The anticoagulation protocol that no heparin after a 3000 units heparin bolus in VV ECMO supported acute respiratory failure patients with hemorrhage risk is feasible.

The Identification of ECG Signals Using Wavelet Transform and WOA-PNN.

Electrocardiogram (ECG) signal identification technology is rapidly replacing traditional fingerprint, face, iris and other recognition technologies, avoiding the vulnerability of traditional recognition technologies. This paper proposes an ECG signal identification method based on the wavelet transform algorithm and the probabilistic neural network by whale optimization algorithm (WOA-PNN). Firstly, Q, R and S waves are detected by wavelet transform, and the P and T waves are detected by local windowed wavelet transform. The characteristic values are constructed by the detected time points, and the ECG data dimension is smaller than that of the non-reference detection. Secondly, combined with the probabilistic neural network, the mean impact value algorithm is used to screen the characteristic values, the characteristic values with low influence are eliminated, and the input and complexity of the model are simplified. Finally, a WOA-PNN combined classification method is proposed to intelligently optimize the hyper parameters in the probabilistic neural network algorithm to improve the model accuracy. According to the simulation verification on three databases, ECG-ID, MIT-BIH Normal Sinus Rhythm and MIT-BIH Arrhythmia, the identification accuracy of a single ECG cycle is 96.97%, and the identification accuracy of three ECG cycles is 99.43%.

The Identification of ECG Signals Using WT-UKF and IPSO-SVM.

The biometric identification method is a current research hotspot in the pattern recognition field. Due to the advantages of electrocardiogram (ECG) signals, which are difficult to replicate and easy to obtain, ECG-based identity identification has become a new direction in biometric recognition research. In order to improve the accuracy of ECG signal identification, this paper proposes an ECG identification method based on a multi-scale wavelet transform combined with the unscented Kalman filter (WT-UKF) algorithm and the improved particle swarm optimization-support vector machine (IPSO-SVM). First, the WT-UKF algorithm can effectively eliminate the noise components and preserve the characteristics of ECG signals when denoising the ECG data. Then, the wavelet positioning method is used to detect the feature points of the denoised signals, and the obtained feature points are combined with multiple feature vectors to characterize the ECG signals, thus reducing the data dimension in identity identification. Finally, SVM is used for ECG signal identification, and the improved particle swarm optimization (IPSO) algorithm is used for parameter optimization in SVM. According to the analysis of simulation experiments, compared with the traditional WT denoising, the WT-UKF method proposed in this paper improves the accuracy of feature point detection and increases the final recognition rate by 1.5%. The highest recognition accuracy of a single individual in the entire ECG identification system achieves 100%, and the average recognition accuracy can reach 95.17%.

Immune Cells in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a complex and serious cardiopulmonary disease; it is characterised by increased pulmonary arterial pressure and pulmonary vascular remodelling accompanied by disordered endothelial and smooth muscle cell proliferation within pulmonary arterioles and arteries. Although recent reports have suggested that dysregulated immunity and inflammation are key players in PAH pathogenesis, their roles in PAH progression remain unclear. Intriguingly, altered host immune cell distribution, number, and polarisation within the lung arterial vasculature have been linked to disease development. This review mainly focusses on the roles of different immune cells in PAH and discusses the underlying mechanisms.

The origin of biological homochirality along with the origin of life.

How homochirality concerning biopolymers (DNA/RNA/proteins) could have originally occurred (i.e., arisen from a non-life chemical world, which tended to be chirality-symmetric) is a long-standing scientific puzzle. For many years, people have focused on exploring plausible physic-chemical mechanisms that may have led to prebiotic environments biased to one chiral type of monomers (e.g., D-nucleotides against L-nucleotides; L-amino-acids against D-amino-acids)-which should have then assembled into corresponding polymers with homochirality, but as yet have achieved no convincing advance. Here we show, by computer simulation-with a model based on the RNA world scenario, that the biased-chirality may have been established at polymer level instead, just deriving from a racemic mixture of monomers (i.e., equally with the two chiral types). In other words, the results suggest that the homochirality may have originated along with the advent of biopolymers during the origin of life, rather than somehow at the level of monomers before the origin of life.

Phylogenetic analysis of classical swine fever virus isolates from China.

Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is a severe disease that causes huge economic losses in the swine industry worldwide. In China, CSF has been under control due to extensive vaccination since 1954. However, there are still sporadic CSF outbreaks in China. Here, we isolated 27 CSFV strains from three Chinese provinces (Shaanxi, Gansu, and Ningxia) from 2011 to 2018. Phylogenetic analysis based on the full-length envelope glycoprotein E2 coding region revealed that 25 out of 27 CSFV isolates clustered within subgroups 2.1 and 2.2, while two strains from Gansu belonged to subgroup 1.1. The sequence identity among these 27 isolates varied from 79.3% to 99.8% (nucleotides) and from 83.1% to 99.7% (amino acids). Further analysis based on the E2 amino acid sequences showed that these new isolates have consistent amino acid substitutions, including R31K and N34S.

Prognostic dynamic nomogram integrated with metabolic acidosis for in-hospital mortality and organ malperfusion in acute type B aortic dissection patients undergoing thoracic endovascular aortic repair.

BACKGROUND: Organ malperfusion is a lethal complication in acute type B aortic dissection (ATBAD). The aim of present study is to develop a nomogram integrated with metabolic acidosis to predict in-hospital mortality and organ malperfusion in patients with ATBAD undergoing thoracic endovascular aortic repair (TEVAR). METHODS: The nomogram was derived from a retrospectively study of 286 ATBAD patients who underwent TEVAR from 2010 to 2017 at a single medical center. Model performance was evaluated from discrimination and calibration capacities, as well as clinical effectiveness. The results were validated using a prospective study on 77 patients from 2018 to 2019 at the same center. RESULTS: In the multivariate analysis of the derivation cohort, the independent predictors of in-hospital mortality and organ malperfusion identified were base excess, maximum aortic diameter ≥ 5.5 cm, renal dysfunction, D-dimer level ≥ 5.44 µg/mL and albumin amount ≤ 30 g/L. The penalized model was internally validated by bootstrapping and showed excellent discriminatory (bias-corrected c-statistic, 0.85) and calibration capacities (Hosmer-Lemeshow P value, 0.471; Brier Score, 0.072; Calibration intercept, - 0.02; Slope, 0.98). After being applied to the external validation cohort, the model yielded a c-statistic of 0.86 and Brier Score of 0.097. The model had high negative predictive values (0.93-0.94) and moderate positive predictive values (0.60-0.71) for in-hospital mortality and organ malperfusion in both cohorts. CONCLUSIONS: A predictive nomogram combined with base excess has been established that can be used to identify high risk ATBAD patients of developing in-hospital mortality or organ malperfusion when undergoing TEVAR.