154 research outputs found
The plastidial retrograde signal methyl erythritol cyclopyrophosphate is a regulator of salicylic acid and jasmonic acid crosstalk.
The exquisite harmony between hormones and their corresponding signaling pathways is central to prioritizing plant responses to simultaneous and/or successive environmental trepidations. The crosstalk between jasmonic acid (JA) and salicylic acid (SA) is an established effective mechanism that optimizes and tailors plant adaptive responses. However, the underlying regulatory modules of this crosstalk are largely unknown. Global transcriptomic analyses of mutant plants (ceh1) with elevated levels of the stress-induced plastidial retrograde signaling metabolite 2-C-methyl-D-erythritol cyclopyrophosphate (MEcPP) revealed robustly induced JA marker genes, expected to be suppressed by the presence of constitutively high SA levels in the mutant background. Analyses of a range of genotypes with varying SA and MEcPP levels established the selective role of MEcPP-mediated signal(s) in induction of JA-responsive genes in the presence of elevated SA. Metabolic profiling revealed the presence of high levels of the JA precursor 12-oxo-phytodienoic acid (OPDA), but near wild type levels of JA in the ceh1 mutant plants. Analyses of coronatine-insensitive 1 (coi1)/ceh1 double mutant plants confirmed that the MEcPP-mediated induction is JA receptor COI1 dependent, potentially through elevated OPDA. These findings identify MEcPP as a previously unrecognized central regulatory module that induces JA-responsive genes in the presence of high SA, thereby staging a multifaceted plant response within the environmental context
Emotional abuse and depressive symptoms among the adolescents: the mediation effect of social anxiety and the moderation effect of physical activity
BackgroundChildhood maltreatment has been identified as a risk factor for depressive symptoms. Social anxiety is closely associated with depression. Physical activity has been regarded as an underlying protective factor. Little is known about the complex relations among these factors in Chinese middle school students. This study aimed to explore whether social anxiety mediated the association between childhood maltreatment and depressive symptoms and investigate whether physical activity moderated the indirect or direct effect of the mediation model.MethodsA total of 1,570 middle school students were recruited and measured for childhood maltreatment (measured by Childhood Trauma Questionnaire—Short Form Chinese version), social anxiety (as the mediator, measured by the Chinese simplified version of Social Anxiety Scale for Adolescents), depressive symptoms (measured by the Chinese version of Depression Anxiety Stress Scales-21), physical activity (as the moderator), and covariates such as age, sex, and nationality. The proposed relationships were tested using mediation and moderated mediation models.ResultsEmotional abuse was directly associated with depression, and the association between emotional abuse and depression was partially mediated by social anxiety. The associations between emotional abuse with depression and with social anxiety were moderated by physical activity.ConclusionThis study revealed the mediating role of social anxiety and the moderating role of physical activity between emotional abuse and depression, which emphasizes the potential benefits of sufficient physical activity to reduce social anxiety and depressive symptoms, and more intervention studies should be conducted to explore the direct influence of sufficient physical activity in the future
Design and experiments of an automatic pipe winding machine
To solve the time-consuming and laborious problem of manual winding and unwinding water pipes by field workers during irrigation or pesticide spraying in agricultural production, an automatic pipe winding machine for winding and unwinding water pipes was designed. The guiding mechanism, pipe winding mechanism, and pipe arrangement mechanism of the pipe winding machine are designed, and the automatic deviation correction control method of pipe arrangement based on PID and the constant tension control method of pipe winding and unwinding is put forward, and the control system of the automatic pipe winding machine is developed. By making a prototype of an automatic pipe winding machine, the effects of pipe winding and unwinding and the constant tension control of the automatic winding machine are tested and analyzed. The test results show that under the condition of 4.0 km/h speed, the maximum angle error of the automatic pipe winding machine is 3.32°, the average absolute error is 0.95°, and the water pipes are arranged neatly and tightly. The maximum relative error of the water pipe tension is 9.3%, and the maximum relative error under the 0~4.0 km/h velocity step variable condition is 16.3%. The speed of the pipe winding and unwinding can adapt to the change of the vehicle’s speed automatically, and the tension of the pipe is within a reasonable range. The performance of the pipe arrangement and pipe coiling of the automatic pipe winding machine can meet the operating requirements
Anti-inflammatory effects of enzymatic hydrolysates of velvet antler in RAW 264.7 cells in vitro and zebrafish model
Enzymatic hydrolysis has been successfully used for the extraction of numerous biologically active components from a wide variety of natural sources. In the present study, velvet antler was subjected to the extraction process using Alcalase protease. We analyzed bioactive components, such as uronic acid, sulfated-glycosaminoglycans (sulfated-GAGs), and sialic acid, present in the velvet antler Alcalase hydrolysate (VAAH) and assessed their anti-inflammatory effects in zebrafish as well as in vitro using cell lines. VAAH mainly contained uronic acid (78.22 mg/g) and sulfated-GAGs (50.47 mg/g), while the amount of sialic acid was negligible (5.55 mg/g). VAAH inhibited the production of nitric oxide (NO) by lipopolysaccharide (LPS)-induced cells in a dosedependent manner and the inhibitory effect of VAAH on NO production was higher than that of hot water extracts. VAAH treatment also reduced the expression of inflammatory mediators such as nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, we evaluated anti-inflammatory effects of VAAH using LPS-stimulated zebrafish. Treatment with LPS significantly increased cell death, NO, and reactive oxygen species (ROS) levels in zebrafish. Notably, VAAH significantly inhibited the extent of LPS-stimulated cell death and generation of NO and ROS in zebrafish. These results suggest that VAAH alleviated inflammation and cell death by inhibiting the generation of ROS induced by LPS treatment. Thus, VAAH could be used as a potential natural remedy with a trong anti-inflammatory effect. Taken together, we believe that based on our present results, enzymatic hydrolysis of velvet antler may be an effective process to make antler products acceptable as elements of health foods and nutraceutical components with increased biological activity
Current understanding of CTLA-4: from mechanism to autoimmune diseases
Autoimmune diseases (ADs) are characterized by the production of autoreactive lymphocytes, immune responses to self-antigens, and inflammation in related tissues and organs. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is majorly expressed in activated T cells and works as a critical regulator in the inflammatory response. In this review, we first describe the structure, expression, and how the signaling pathways of CTLA-4 participate in reducing effector T-cell activity and enhancing the immunomodulatory ability of regulatory T (Treg) cells to reduce immune response, maintain immune homeostasis, and maintain autoimmune silence. We then focused on the correlation between CTLA-4 and different ADs and how this molecule regulates the immune activity of the diseases and inhibits the onset, progression, and pathology of various ADs. Finally, we summarized the current progress of CTLA-4 as a therapeutic target for various ADs
The aging lung: microenvironment, mechanisms, and diseases
With the development of global social economy and the deepening of the aging population, diseases related to aging have received increasing attention. The pathogenesis of many respiratory diseases remains unclear, and lung aging is an independent risk factor for respiratory diseases. The aging mechanism of the lung may be involved in the occurrence and development of respiratory diseases. Aging-induced immune, oxidative stress, inflammation, and telomere changes can directly induce and promote the occurrence and development of lung aging. Meanwhile, the occurrence of lung aging also further aggravates the immune stress and inflammatory response of respiratory diseases; the two mutually affect each other and promote the development of respiratory diseases. Explaining the mechanism and treatment direction of these respiratory diseases from the perspective of lung aging will be a new idea and research field. This review summarizes the changes in pulmonary microenvironment, metabolic mechanisms, and the progression of respiratory diseases associated with aging
Spread of Streptococcus suis Sequence Type 7, China
Streptococcus suis sequence type (ST) 7 has been spreading throughout China. To determine events associated with its emergence, we tested 114 isolates. In all 106 ST7 strains responsible for human outbreaks and sporadic infections, the tetracycline-resistance gene, tetM, was detected on the conjugative transposon Tn916. Horizontal transmission of tetM is suspected
Mapping blue-ice areas in Antarctica using ETM+ and MODIS data
AbstractBlue-ice areas (BIAs) and their geographical distribution in Antarctica were mapped using Landsat-7 ETM+ images with 15 m spatial resolution obtained during the 1999–2003 austral summers and covering the area north of 82.5° S, and a snow grain-size image of the MODIS-based Mosaic of Antarctica (MOA) dataset with 125 m grid spacing acquired during the 2003/04 austral summer from 82.5°S to the South Pole. A map of BIAs was created with algorithms of thresholds based on band ratio and reflectance for ETM+ data and thresholds based on snow grain size for the MOA dataset. The underlying principle is that blue ice can be separated from snow or rock by their spectral discrepancies and by different grain sizes of snow and ice. We estimate the total area of BIAs in Antarctica during the data acquisition period is 234 549 km2, or 1.67% of the area of the continent. Blue ice is scattered widely over the continent but is generally located in coastal or mountainous regions. The BIA dataset presented in this study is the first map covering the entire Antarctic continent sourced solely from ETM+ and MODIS data. This dataset can potentially benefit other studies in glaciology, meteorology, climatology and paleoclimate, meteorite collection and airstrip site selection.</jats:p
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