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Gig economy has attracted people’s attention and aroused a widely discussion in recent years. Online gig economy market plays an important role in gig economy due to its unique characteristics, which provides more conveniences and availabilities to workers. In 2020, COVID-19 influenced the whole world in many aspects, where not only the people’s health is in danger, but also the world economy is retailed. On this occasion, we investigate the relationship between gig online economy and COVID-19 by Online Labour Index (OLI) and VAR model. OLI tracks the number of online projects and works in different countries and various occupations. On this basis, the study chooses two occupations, Professional services and Software development and technology, to analyse precisely and specifically. The original hypothesis is that COVID-19 is supposed to have a positive effect on online gig economy since it provides a contactless working environment. However, the study shows that COVID-19 do not have an obvious impact on these two occupations, and people are supposed to find other influence factors out of this result to poromote markets’ further development from various aspects.

BackgroundA subset of patients require a tracheostomy as respiratory support in a severe state after cardiac surgery. There are limited data to assess the predictors for requiring postoperative tracheostomy (POT) in cardiac surgical patients.MethodsThe records of adult patients who underwent cardiac surgery from 2016 to 2019 at our institution were reviewed. Univariable analysis was used to assess the possible risk factors for POT. Then multivariable logistic regression analysis was performed to identify independent predictors. A predictive scoring model was established with predictor assigned scores derived from each regression coefficient divided by the smallest one. The area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test were used to evaluate the discrimination and calibration of the risk score, respectively.ResultsA total of 5,323 cardiac surgical patients were included, with 128 (2.4%) patients treated with tracheostomy after cardiac surgery. Patients with POT had a higher frequency of readmission to the intensive care unit (ICU), longer stay, and higher mortality (p < 0.001). Mixed valve surgery and coronary artery bypass grafting (CABG), aortic surgery, renal insufficiency, diabetes mellitus, chronic obstructive pulmonary disease (COPD), pulmonary edema, age >60 years, and emergent surgery were independent predictors. A 9-point risk score was generated based on the multivariable model, showing good discrimination [the concordance index (c-index): 0.837] and was well-calibrated.ConclusionsWe established and verified a predictive scoring model for POT in patients who underwent cardiac surgery. The scoring model was conducive to risk stratification and may provide meaningful information for clinical decision-making.

Background: Postoperative pneumonia (POP) is a frequent complication following cardiac surgery, related to increased morbidity, mortality and healthcare costs. The objectives of this study were to investigate the risk factors associated with POP in adults undergoing elective cardiac surgery and to develop and validate nomogram models.Methods: We conducted a multicenter retrospective study in four cardiac centers in China. Adults operated with elective open-heart surgery from 2016 to 2020 were included. Patients were randomly allocated to training and validation sets by 7:3 ratio. Demographics, comorbidities, laboratory data, surgical factors, and postoperative outcomes were collected and analyzed. Risk factors for POP were identified by univariate and multivariate analysis. Nomograms were constructed based on the multivariate logistic regression models and were evaluated with calibration, discrimination and decision curve analysis.Results: A total of 13,380 patients meeting the criteria were included and POP developed in 882 patients (6.6%). The mortality was 2.0%, but it increased significantly in patients with POP (25.1 vs. 0.4%, P < 0.001). Using preoperative and intraoperative variables, we constructed a full nomogram model based on ten independent risk factors and a preoperative nomogram model based on eight preoperative factors. Both nomograms demonstrated good calibration, discrimination, and were well validated. The decision curves indicated significant clinical usefulness. Finally, four risk intervals were defined for better clinical application.Conclusions: We developed and validated two nomogram models for POP following elective cardiac surgery using preoperative and intraoperative factors, which may be helpful for individualized risk evaluation and prevention decisions.

CD4+T cell-mediated acute rejection remains a major factor that affects the early survival of transplanted organs post-transplantation. Here, we reveal that nuclear receptor subfamily 4 Group A member 1 (Nr4A1) was upregulated during cardiac allograft rejection and that the increased Nr4A1 was primarily localized in intragraft-infiltrating CD4+T cells. Nr4A1 acts as a transcription factor with an important role in CD4+T cell apoptosis, differentiation and T cell dysfunction, which indicates that Nr4A1 may play a critical role in transplant rejection. Cytosporone B (Csn-B) is a naturally occurring agonist of Nr4A1, and the role of Csn-B in the physiological process of cardiac rejection is poorly defined. This study constructed an acute rejection model of abdominal heterotopic cardiac transplantation in mice and investigated whether Csn-B could attenuate acute transplant rejection by modulating the CD4+T lymphocyte response. The results showed that Csn-B prolonged murine cardiac allograft survival and reduced inflammation in allografts. Subsequently, it was confirmed that Csn-B functions by inducing non-Treg apoptosis and promoting Treg cell differentiation. Finally, we also confirmed that Csn-B attenuates acute rejection by directly targeting Nr4A1 in CD4+T cells. Our data suggest that Csn-B is a promising novel therapeutic approach for acute cardiac allograft rejection.

Since the 1950s，plastics have been widely used and the manufacture of plastics has grown rapidly because of its wide usage and cheapness. However, too many plastic products bring a lot of pressure on the environment. Not only on the land, but also in the ocean, plastic waste can be seen pervasively. Without implementing effective measures, the environment system will be damaged and our life will be affected. We address the problem of providing a maximum level of single-use or disposable plastic product waste that can be mitigated. Also we evaluated the impact for achieving the level. We divide the plan into three phases. Firstly, we find influence factors and establish models to estimate the maximum levels of single-use or disposable plastic product waste that can be mitigated safely. Next, based on our models, we calculate the minimal level of the single-use or disposable plastic product waste and discuss the impacts for achieving the level. In the next phase, we give ideas on the equity issues in this global problem as well as our solutions.

Objective— Thoracic aortic aneurysm and dissection (TAAD) are severe vascular conditions. Dysfunctional transforming growth factor-β (TGF-β) signaling in vascular smooth muscle cells and elevated angiotensin II (AngII) levels are implicated in the development of TAAD. In this study, we investigated whether these 2 factors lead to TAAD in a mouse model and explored the possibility of using microRNA-21 ( miR-21 ) for the treatment of TAAD. Approach and Results— TAAD was developed in Smad3 (mothers against decapentaplegic homolog 3) heterozygous (S3 +/− ) mice infused with AngII. We found that p-ERK (phosphorylated extracellular regulated protein kinases)– and p-JNK (phosphorylated c-Jun N-terminal kinase)–associated miR-21 was higher in TAAD lesions. We hypothesize that downregulation of miR-21 mitigate TAAD formation. However, Smad3 +/− :miR-21 −/− (S3 +/− 21 −/− ) mice exhibited conspicuous TAAD formation after AngII infusion. The vascular wall was dilated, and aortic rupture occurred within 23 days during AngII infusion. We then examined canonical and noncanonical TGF-β signaling and found that miR-21 knockout in S3 +/− mice increased SMAD7 and suppressed canonical TGF-β signaling. Vascular smooth muscle cells lacking TGF-β signals tended to switch from a contractile to a synthetic phenotype. The silencing of Smad7 with lentivirus prevented AngII-induced TAAD formation in S3 +/− 21 −/− mice. Conclusions— Our study demonstrated that miR-21 knockout exacerbated AngII-induced TAAD formation in mice, which was associated with TGF-β signaling dysfunction. Therapeutic strategies targeting TAAD should consider unexpected side effects associated with alterations in TGF-β signaling.

Background This study sought to establish a new model of high-flow pulmonary hypertension (PH) in mice. This model may be useful for studies seeking to reduce the pulmonary vascular resistance and delay the development of PH caused by congenital heart disease. Materials and methods The right pulmonary artery was ligated via a right posterolateral thoracotomy. Pulmonary hemodynamics was evaluated by right heart catheterization immediately after ligation and at 2, 4, 8, and 12 wk postoperatively. The right ventricle (RV) and the left ventricle (LV) with septum (S) were weighed to calculate the RV/(LV + S) ratio as an index of right ventricular hypertrophy. Morphologic changes in the left lungs were analyzed, and percentages of muscularized pulmonary vessels were assessed by hematoxylin and eosin, elastica van Gieson and alpha-smooth muscle actin staining. All the study data were compared with data from a model of PH generated by hypoxic stimulation. Results A pulmonary hypertensive state was successfully induced by 2 wk after surgery. However, the morphologic analysis demonstrated that pulmonary vascular muscularization, as evaluated using right ventricular systolic pressure and RV/(LV + S), was not significantly increased until 4 wk postoperatively. When mice from the new model and the hypoxic model were compared, no significant differences were observed in any of the evaluated indices. Conclusions High-flow PH can be induced within 4 wk after ligation of the right pulmonary artery, which is easily performed in mice. Such mice can be used as a model of high-flow PH.

Background MicroRNAs (miRNAs) are integral for maintaining immune homeostasis and self-tolerance. The influence of miRNAs on T-cell differentiation and plasticity are critical in the development of chronic rejection of transplanted hearts. In this study, we sought to determine whether the knockout of miR-155 affects the development of cardiac allograft vasculopathy (CAV) in a murine model. Methods miRNA microarray and quantitative polymerase chain reaction (qPCR) analyses were performed for allograft neointimal lesion samples in chronic rejection. A model of heterotopic murine heart transplantation (bm12 to miR-155 +/+ or miR-155 –/– mice) was then used to analyze allograft survival, histology, mRNA expression and T-cell sub-populations in spleens. The accelerated experiments were performed by intraperitoneal injection of either recombinant interleukin-17A or phosphate-buffered saline (PBS) after heart transplantation. For the competitive transfer experiments, CD4 + splenocytes from wild-type (WT) or miR-155 –/– mice were mixed and injected into Rag1 –/– mice, and cardiac transplantation was performed after 24 hours. The differentiation of T-helper subsets (Th1/Th17/iTreg) was investigated in vitro. Results miR-155 –/– mice showed resistance to cardiac rejection along with weakened T-cell–mediated inflammation, especially for Th17 cells. Recombinant IL-17A could restore this relieved injury. The competitive experiments implied that miR-155 plays a vital role in the stability of the Th17 phenotype. In vitro, we also demonstrated that miR-155 –/– mice exhibit a defect in Th17 differentiation. Conclusions miR-155 regulates Th1/Th17-related inflammation in chronic cardiac rejection and may be a potential therapeutic target to attenuate cardiac allograft rejection. Despite advancements in immunosuppressive therapy, the immunologic mechanisms responsible for allograft rejection remain an important issue for both clinicians and researchers. Allograft rejection is a T-cell–dependent phenomenon and is critically dependent on inflammation mediated by CD4 + Th subsets, including Th1, Th2, Th17, Th9 and regulatory T (Treg) cells.

Background The arteriovenous fistula ( AVF ) is the preferred hemodialysis access for patients with chronic kidney disease. Chronic kidney disease can increase neointima formation, which greatly contributes to AVF failure by an unknown mechanism. Our study aimed to determine the role of nucleotide‐binding oligomerization domain‐like receptor protein 3 ( NLRP 3) in neointima formation induced by experimental AVF s in the presence of chronic kidney disease. Methods and Results From our findings, NLRP 3 was upregulated in the intimal lesions of AVF s in both uremic mice and patients. Smooth muscle–specific knockout NLRP 3 mice exhibited markedly decreased neointima formation in the outflow vein of AVF s. Compared with primary vascular smooth muscle cells isolated from control mice, those isolated from smooth muscle–specific knockout NLRP 3 mice showed compromised proliferation, migration, phenotypic switching, and a weakened ability to activate mononuclear macrophages. To identify how NLRP 3 functions, several small‐molecule inhibitors were used. The results showed that NLRP 3 regulates smooth muscle cell proliferation and migration through Smad2/3 phosphorylation rather than through caspase‐1/interleukin‐1 signaling. Unexpectedly, the selective NLRP 3‐inflammasome inhibitor MCC 950 also repressed Smad2/3 phosphorylation and relieved chronic kidney disease–promoted AVF failure independent of macrophages. Conclusions Our findings suggest that NLRP 3 in vascular smooth muscle cells may play a crucial role in uremia‐associated AVF failure and may be a promising therapeutic target for the treatment of AVF failure.

Background/Aims: Cardiac fibrosis is the primary cause of deteriorated cardiac function in various cardiovascular diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are critical regulators of myocardial fibrosis. Specifically, many studies have reported that miR-150 is downregulated in cardiovascular diseases, such as acute myocardial infarction (AMI), myocardial hypertrophy and myocardial fibrosis. However, the exact role of miR-150 in these pathological processes remains unknown. Methods: We used the transverse aortic constriction (TAC) mouse model to study the role of miR-150 in cardiac fibrosis induced by pressure overload. After the TAC operation, qRT-PCR was used to measure the expression profiles of miR-150 in left ventricle tissues and populations of primary heart cell types. Then, we used both miR-150 knockout mice and wild type (WT) mice in the TAC model. Changes in cardiac function and pathology were measured using transthoracic echocardiography and pathological analysis, respectively. Furthermore, we predicted the target of miR-150 in cardiac fibroblasts (CFs) and completed in vitro CF transfection experiments using miR-150 analogs and siRNA corresponding to the predicted target. Results: We observed decreased expression levels of miR-150 in hearts suffering pressure overload, and these levels decreased more sharply in CFs than in cardiomyocytes. In addition, the degrees of cardiac function deterioration and cardiac fibrosis in miR-150-/- mice were more severe than were those in WT mice. By transfecting CFs with an miR-150 analog in vitro, we observed that miR-150 inhibited cardiac fibroblast activation. We predicted that the transcription factor c-Myb was the target of miR-150 in CFs. Transfecting CFs with c-Myb siRNA eliminated the effects of an miR-150 inhibitor, which promoted CF activation. Conclusion: These findings reveal that miR-150 acts as a pivotal regulator of pressure overload-induced cardiac fibrosis by regulating c-Myb.

Background Severe cardiac hypertrophy can lead to cardiac remodeling and even heart failure in the end, which is a leading cause of cardiovascular disease–related mortality worldwide. A disintegrin and metalloprotease‐22 ( ADAM 22), a member of the transmembrane and secreted metalloendopeptidase family, participates in many biological processes, including those in the cardiovascular system. However, there is no explicit information on whether ADAM 22 can regulate the process of cardiac hypertrophy; the effects that ADAM 22 exerts in cardiac hypertrophy remain elusive. Methods and Results We observed significantly increased ADAM 22 expression in failing hearts from patients with dilated cardiomyopathy and hypertrophic cardiomyopathy; the same trend was observed in mice induced by transaortic constriction and in neonatal rat cardiomyocytes treated by angiotensin II . Therefore, we constructed both cardiac‐specific ADAM 22 overexpression and knockout mice. At 4 weeks after transaortic constriction, cardiac‐specific ADAM 22 knockout, by the CRISPR/Cas9 (clustered regularly interspaced palindromic repeat (CRISPR)–Cas9) system, deteriorated the severity of cardiac hypertrophy in mice, whereas cardiac‐specific ADAM 22 overexpression mitigated the degrees of cardiac hypertrophy in mice. Similarly, altered ADAM 22 expression modulated the angiotensin II –mediated cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. After screening several signaling pathways, we found ADAM 22 played a role in inhibition of protein kinase B ( AKT ) activation. Under the cardiac‐specific ADAM 22 knockout background, AKT activation was enhanced in transaortic constriction–induced mice and angiotensin II –stimulated neonatal rat cardiomyocytes, with a severe degree of cardiac hypertrophy. Treatment of a specific AKT inhibitor attenuated the transaortic constriction–enhanced AKT activation and cardiac hypertrophy in mice. Conclusions The findings demonstrated that ADAM 22 negatively regulates the AKT activation and the process of cardiac hypertrophy and may provide new insights into the pathobiological features of cardiac hypertrophy.

Graft arteriosclerosis (GA) is the leading cause of late cardiac allograft dysfunction. The innate immune system plays a major role in GA, paprticularly Toll-like receptor 4 (TLR4) signaling. Here we characterized the role of TLR4 and its antagonist TAK-242 in a mouse model of GA. BALB/c (H-2d) donor aortas were transplanted into C57BL/6 (H-2b) recipients, and the mice received intraperitoneal injection of 3 or 10 mg/kg of TAK-242 or vehicle every other day for 1, 2, 4, 6, 8 and 12 weeks. With TAK-242 administration, intimal hyperplasia initially appeared at 2 weeks after transplantation, and TAK-242 postponed the progression of neointimal formation in allogeneic aortic grafts. TAK-242 treatment reduced CD68+ macrophage accumulation in the allografts, reduced the levels of ly-6Chi monocytes in peripheral blood, bone marrow and spleen, and downregulated proinflammatory cytokine and chemokine levels. Ex vivo we observed that TAK-242 could improve the graft microenvironment by interfering the Tck/Mφ IL12p70 and IFNγ axis, reducing CCL2-mediated migration of vascular smooth cells.

Transforming growth factor-beta (TGF-β) plays a significant role in the pathogenesis of the intimal hyperplasia of transplant arteriosclerosis (TA). The aim of this study was to evaluate the efficacy of an oral inhibitor of TGF-β receptor I kinase (SD-208) on the development of TA.BALB/c (H-2(d)) donor aortas were transplanted into C57BL/6 (H-2(b)) recipients, and the mice then received different doses (40 or 60 mg/kg) of SD-208 or control vehicle by daily gavage for 8 weeks. The grafts were analyzed by histology and morphometry at 1, 2, 4, 6 and 8 weeks after transplantation. The effects of TGF-β and SD-208 on neointimal smooth muscle-like cell (SMLC) and vascular smooth muscle cell (VSMC) proliferation and migration were evaluated, and the expression levels of Smad3, P-Smad3, connective tissue growth factor (CTGF) and collagen I were determined by in vitro experiments.The intimal hyperplasia of the SD-208-treated group was significantly reduced compared with the vehicle-treated control group (32% and 48% reduction for 40 mg/kg and 60 mg/kg SD-208 compared with the controls, respectively [n = 5], p0.05). SD-208 reduced SMLC proliferation and the production of intimal collagen by 21% and 75%, respectively, in the grafts. SD-208 also abolished the promoting effect of TGF-β on SMLC proliferation and migration but did not affect TGF-β inhibition of VSMCs in vitro. CTGF, a protein downstream of TGF-β, was downregulated with the inhibition of Smad3 phosphorylation by SD-208, both in vitro and in vivo. Moreover, we found that the endogenous Smad3 in SMLCs was upregulated from 2 weeks after transplantation and was 64% higher than in VSMCs at 8 weeks.These results demonstrate that SD-208 can effectively reduce the formation of intimal hyperplasia of TA in the murine aortic allograft model.

Background Sepsis occurs when an infection triggers deranged inflammatory responses. There exists no efficacious treatment for this condition. The transcriptional repressor B-cell Lymphoma 6 (BCL6) is known to act as an inhibitor of macrophage-mediated inflammatory responses. FX1, a novel specific BCL6 BTB inhibitor, is able to attenuate activity of B cell-like diffuse large B cell lymphoma (ABC-DLBCL). Nevertheless, the effect of FX1 in inflammatory responses and sepsis remains unknown. Objectives Here, we explored the effect and potential mechanisms of FX1 on the regulation of LPS-induced inflammatory responses in murine sepsis. Method Mice models of LPS-induced sepsis were monitored for survival rate following FX1 administration. ELISA was used to assess how FX1 administration affected pro-inflammatory cytokines present in macrophages exposed to LPS and in the serum of mice sepsis models. Flow cytometric analysis, Western blot and qRT-PCR were performed to evaluate differences in macrophages immune responses after FX1 pre-treatment. Finally, the affinity of BCL6 binding to downstream target genes was checked by ChIP. Results The survival rate of mice models of LPS-induced sepsis was improved in following FX1 administration. FX1 decreased the production of inflammatory cytokines, attenuated macrophage infiltration activities and reduced monocytes chemotaxis activities, all of which suggest that FX1 exert anti-inflammatory effects. Mechanistically, FX1 may enhance the affinity of BCL6 binding to downstream target pro-inflammatory genes. Conclusions These findings illustrated the anti-inflammatory properties and potential mechanisms of FX1 in sepsis caused by LPS. FX1 could potentially become a new immunosuppressive and anti-inflammatory drug candidate in sepsis therapy.

Objective Arteriovenous fistula (AVF) suffers from a high number of failures caused by insufficient outward remodeling and venous neointimal hyperplasia formation. The aim was to investigate the exact mechanism by which microRNA-155 (miR-155) in the outflow vein of AVF is regulated. Methods AVFs between the branch of the jugular vein and carotid artery in an end-to-end manner were created in C57BL/6 and miR-155−/− mice with a C57BL/6 background. The venous segments were harvested at day 7, 14, 21, and 28, and the AVFs were analyzed histologically and at a messenger RNA level using real-time quantitative polymerase chain reactions. The outflow vein of AVF and the normal great saphenous vein, collected from patients with chronic kidney disease and coronary artery bypass surgery, were analyzed by histologic and molecular biologic approaches. Results Venous neointimal hyperplasia is significantly alleviated in miR-155−/− mice, and the expression of several chemokines and cytokines in the vessel wall, including regulated on activation, normal T-cell expressed and secreted factor (RANTES), monocyte chemoattractant protein 1, and vascular endothelial growth factor, was inhibited. miR-155 promoted the RANTES expression of smooth muscle-like cells, which in turn facilitated cell proliferation and extracellular matrix production. Conclusions miR-155 enhances venous neointima formation through the autocrine and paracrine effects of smooth muscle-like cell-derived RANTES in a nuclear factor κB-dependent manner during the entire AVF process, especially at the advanced stage.

Objective— Smooth muscle–like cells are major cell components of transplant arteriosclerosis lesions. This study investigated the origin of the smooth muscle–like cells, the mechanisms responsible for their accumulation in the neointima, and the factors that drive these processes. Approach and Results— A murine aortic transplantation model was established by transplanting miR-155 −/− bone marrow cells into miR-155 +/+ mice. MicroRNA-155 was found to play a functional role in the transplant arteriosclerosis. Moreover, we found that the nonbone marrow–derived progenitor cells with markers of both early differentiated smooth muscles and stem cells in the allograft adventitia were smooth muscle progenitor cells. Purified smooth muscle progenitor cells expressed a mature smooth muscle cell marker when induced by platelet-derived growth factor-BB in vitro. In vivo, these cells could migrate into the intima from the adventitia and could contribute to the neointimal hyperplasia. The loss of microRNA-155 in bone marrow–derived cells decreased the concentration gradient of monocyte chemoattractant protein 1 between the intima and the adventitia of the allografts, which reduced the migration of smooth muscle progenitor cells from the adventitia into the neointima. Conclusions— This study demonstrated that microRNA-155 promoted the directional migration of smooth muscle progenitor cells from the adventitia by regulating the monocyte chemoattractant protein 1 concentration gradient, which aggravated transplant arteriosclerosis.

Background— MicroRNAs (miRs) and inflammatory monocytes participate in many cardiac pathophysiological processes including acute myocardial infarction (AMI). Recently, we observed that miR-150 is downregulated in injured mouse plasma after AMI as well as in human infarcted monocytes. However, the precise functional role of miR-150 in response to AMI remains unknown. Methods and Results— In a mouse model of AMI and in human subjects with AMI, we found that miR-150 expression was reduced in monocytes. In vitro studies showed that ectopic expression of miR-150 markedly reduced monocyte migration and proinflammatory cytokine production, whereas blockade of miR-150 had opposing effects. In vivo studies showed that overexpression of miR-150 in mice resulted in improved cardiac function, reduced myocardial infarction size, inhibition of apoptosis, and reduced inflammatory Ly-6C high monocyte invasion levels after AMI. Wild-type mice transplanted with miR-150 null (−/−) bone marrow cells could reverse this protective effect. Mechanistic studies demonstrated that miR-150 inhibited the expression of chemokine receptor 4 (CXCR4), thereby promoting monocyte migration. Conclusions— Our findings indicate that miR-150 acts as a critical regulator of monocyte cell migration and production of proinflammatory cytokines, leading to cardioprotective effects against AMI-induced injury. Thus, miR-150 may be a suitable target for therapeutic intervention in the setting of ischemic heart disease.