Are algorithmically controlled gig workers deeply burned out? An empirical study on employee work engagement.

BACKGROUND: With the emergence of the gig economy as a new economic form, the influence of algorithmic technology control on gig workers' perceptions and engagement has become a topic of academic concern. This study explores the emotional impact of perceived algorithmic control on gig workers and how it affects their work engagement. METHODS: This study takes gig workers as the research object to build a structural equation model. Based on the background of gig economy and the Job Demands-Resources model, this paper constructs a mechanism model of the influence of perceived algorithmic control on the work engagement of gig workers. The research data in this paper are collected by questionnaire, and the research hypothesis is tested by the SEM structural model. RESULTS: The gig workers in this study believed that perceived algorithmic control positively affects employee work engagement. In addition, burnout was positively correlated with employee work engagement. Burnout played a partial mediating role in the relationship between perceived algorithmic control and employee work engagement. And flow experience played a moderating role through the indirect effect of burnout on employees' work engagement. CONCLUSION: Perceived algorithmic control causes burnout among gig workers, but strong algorithmic technology support provides them with rich work resources that can help them meet their work needs. That is, the gig workers may still demonstrate a high level of work engagement even if they experience burnout symptoms.

[An epidemiological investigation of chronic kidney disease in children with hearing disorder in Hunan province, China].

OBJECTIVE: To investigate the prevalence of chronic kidney disease (CKD) among the children with hearing disorder in Hunan province, China. METHODS: In this cross-sectional study, the multi-stage cluster sampling method was used to select 1 500 children as subjects. Questionnaire surveys, physical examinations, and laboratory examinations were performed on the spot. RESULTS: Among the 1 500 children, 1 459 with complete data were included in analysis. Among the 1 459 children, 43 had CKD, with a prevalence rate of 2.95%. The <7 years group had a significantly higher prevalence rate than the 7-14 years group [5.8% (35/604) vs 0.9% (8/855); P<0.05]. Among the 43 children with CKD, 31 (72%) had proteinuria, 27 (63%) had hematuria, and 11 (26%) had a decreased glomerular filtration rate. Among the 43 children with CKD, stage 1, 2, 3a, 3b, 4, and 5 CKD accounted for 30% (13 cases), 44% (19 cases), 12% (5 cases), 7% (3 cases), 7% (3 cases), and 0% (0 case) respectively. The prevalence rate of CKD increased with the severity of hearing disorder (P<0.01). CONCLUSIONS: The prevalence rate of CKD is higher among the children with hearing disorder in Hunan province. Most children have early-stage CKD. CKD is commonly seen in preschool children. Severity of hearing disorder is associated with the prevalence of CKD.

[Effect of dexmedetomidine postconditioning on myocardial ischemia-reperfusion injury and inflammatory response in diabetic rats].

OBJECTIVE: To investigate the effect of dexmedetomidine postconditioning in alleviating myocardial ischemia-reperfusion (IR) injury and inflammation in diabetic mellitus rats. METHODS: Thirty normal male Sprauge Dawley (SD) rats were randomly allocated into 3 groups (n=10), namely the sham-operated group, IR group, and dexmedetomidine postconditioning (DP) group. Similarly, another thirty diabetic SD rats were also randomly allocated into diabetic sham (DM-S) group, diabetic IR (DM-IR) group and diabetic dexmedetomidine postconditioning (DM-DP) group. The mean arterial pressure (MAP), heart rate (HR) and the rate pressure product (RPP) were recorded at baseline, after 30 min of ischemia, and at 30 and 120 min during reperfusion. Myocardial infarct size was analyzed by TTC double staining method, and plasma levels of CTnI, TNF-a, IL-6, IL-10 and IL-1ß were measured at 120 min of reperfusion. RESULTS: Compared with those in the sham-operated group, normal and diabetic rats in IR and DP groups showed significantly lowered MAP, HR, and RPP and increased levels of plasma CTnI, TNF-a, IL-6, IL-10 and IL-1ß levels after 30 min of ischemia and at 30 min and 120 min of reperfusion (P<0.05). Compared with those in the IR group, the normal rats in DP group showed decreased MAP, HR, and RPP at 30 min of ischemia and at 30 min of reperfusion, which increased at 120 min of reperfusion (P<0.05); the infarct size and plasma CTnI, TNF-a, IL-6 and IL-1ß levels were decreased while IL-10 was increased in DP group (P<0.05). Compared with those in DP group, the rats in DM-DP group showed similar MAP, HR and RPP (P>0.05) but significantly increased infarct size and plasma CTnI, TNF-a, IL-6 and IL-1ß levels (P<0.05). CONCLUSION: Dexmedetomidine postconditioning may produce a cardioprotective effect against myocardial IR injury in normal rats by alleviating inflammation, but can not reduce the release of inflammatory mediators in diabetic rats to improve myocardial infarction.

[Effect of high concentration glucose on the expression of ALDH2 in cardiac fibroblasts of rats].

OBJECTIVE: To observe whether acetaldehyde dehydrogenase 2 (ALDH2) is expressed in cardiac fibroblasts and investigate the change of ALDH2 in cardiac fibroblasts when cultured with high concentration of glucose. METHODS: Cultured cardiac fibroblasts were randomly divided into four groups:normal control group (5.5 mmol/L glucose), Alda-1 (the agonist of ALDH2, 20µmol/L) group, high glucose group (30 mmol/L glucose) and high glucose + Alda-1 group. Cardiac fibroblasts were identified by immunofluore-scence technique. Cell prolifera-tion was detected by MTT method after treated with drugs for 48 hours. mRNA and protein expressions of ALDH2 were determined by RT-PCR and Western blot, aimed to ensure whether ALDH2 was expressed in cardiac fibroblasts. The changes of ALDH2 protein expression in cardiac fibroblasts were tested by Western blot. RESULTS: RT-PCR and Western blot results revealed that ALDH2 was expressed in cardiac fibroblasts. Compared with normal control group, cardiac fibroblasts proliferation was increased (P < 0.05), while the protein expression of ALDH2 was reduced (P < 0.05) in high glucose group. When treated with Alda-1, the proliferation of cardiac fibroblasts was decreased (P < 0.01), while the protein expression of ALDH2 was increased (P < 0.05) in high glucose group. CONCLUSIONS: ALDH2 was expressed in cardiac fi-broblasts. Alda-1, the agonist of ALDH2 enhanced the expression of ALDH2 and inhibited the proliferation of cardiac fibroblasts when cultured with high concentration of glucose.

Effects of dexmedetomidine postconditioning on myocardial ischemia and the role of the PI3K/Akt-dependent signaling pathway in reperfusion injury.

The present study aimed to determine whether post-ischemic treatment with dexmedetomidine (DEX) protected the heart against acute myocardial ischemia/reperfusion (I/R)­induced injury in rats. The phosphatidylinositol­3 kinase/protein kinase B(PI3K/Akt)­dependent signaling pathway was also investigated. Male Sprague Dawley rats (n=64) were subjected to ligation of the left anterior descending artery (LAD), which produced ischemia for 25 min, followed by reperfusion. Following LAD ligation, rats were treated with DEX (5, 10 and 20 µg/kg) or underwent post­ischemic conditioning, which included three cycles of ischemic insult. In order to determine the role of the PI3K/Akt signaling pathway, wortmannin (Wort), a PI3K inhibitor, was used to treat a group of rats that had also been treated with DEX (20 µg/kg). Post­reperfusion, lactate dehydrogenase (LDH), cardiac troponin I (cTnI), creatine kinase isoenzymes (CK­MB), superoxide dismutase (SOD) and malondialdehyde (MDA) serum levels were measured using an ultraviolet spectrophotometer. The protein expression levels of phosphorylated (p)­Akt, Ser9­p­glycogen synthase kinase­3ß (p­GSK­3ß) and cleaved caspase­3 were detected in heart tissue by western blotting. The mRNA expression levels of B­cell lymphoma 2 (Bcl­2) and Bcl­2­associated X protein (Bax) were detected using reverse transcription­polymerase chain reaction. At the end of the experiment, the hearts were removed and perfused in an isolated perfusion heart apparatus with Evans blue (1%) in order to determine the non­ischemic areas. The risk and infarct areas of the heart were not dyed. As expected, I/R induced myocardial infarction, as determined by the increased serum levels of cTnI, CK­MB and MDA, and the decreased levels of SOD. Post­ischemic treatment with DEX increased the expression levels of p­Akt and p­GSK­3ß, whereas caspase­3 expression was reduced following DEX treatment compared with in the I/R group. Compared with the I/R group, the ratio of Bcl­2/Bax at the mRNA level was elevated in the DEX and ischemic post­conditioning groups, whereas the expression levels of Bax were decreased. Conversely, the effects of DEX were attenuated by Wort. These results indicated that, similar to post­ischemic conditioning, post­ischemic treatment with DEX protects the heart against I/R via the PI3K/Akt­dependent signaling pathway, possibly by activating GSK­3ß.

[Value of endobronchial ultrasound-transbronchial needle aspiration biopsy for diagnosis of PET-CT positive mediastinal lymph nodes].

OBJECTIVE: To evaluate the clinical value of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) biopsy for diagnosis of PET-CT positive mediastinal lymph nodes. METHODS: One hundred and twenty-six patients with lung cancer undergoing both PET-CT scanning and EBUS-TBNA biopsy in the First Affiliated Hospital of Guanzhou Medical College from July 2008 to August 2010 were included in this study. There were 89 male and 37 female patients with a mean age of 56.3 years (range 34 to 81 years). (18)FDG-PET was considered positive in mediastinal nodes if the PET-CT reported hypermetabolic activity consistent with malignant disease (standardized uptake value > 2.5). All of the patients were clinically followed up. RESULTS: Among the 126 patients, 185 stations of lymph nodes were punctured. The mean diameter of the nodes was 13.6 mm and the range was 6 - 23 mm. There were no procedural complications. The diagnostic accuracy, sensitivity, and specificity of EBUS-TBNA were 95.7%, 95.7%, and 100%, respectively. CONCLUSIONS: EBUS-TBNA is a minimally invasive, highly effective and accurate, practical and safe procedure for diagnosis of PET-CT positive mediastinal lymph nodes.

[Single lung transplantation for emphysema: analysis of 6 cases].

OBJECTIVE: To review the experience with the management of single lung transplantation for emphysema. METHODS: Between January 2003 and August 2006, single lung transplantation was performed in 6 patients for emphysema with cold low potassium solution flushing. A triple-drug regimen was adopted using steroids, mycophenolate mofetil and tacrolimus as the maintenance immunosuppressants. Chest radiograph score, oxygenation index, and pulmonary arterial pressure of the patients in early after the transplantation were reviewed. RESULTS: All the 6 patients survived for over 30 days after the operation, and 4 of them remained alive with good quality-of-life. Four patients recovered from acute rejection successfully after methylprednisolone pulse therapy for 3 days. One patient underwent reoperation for hemorrhage in the thoracic cavity and finally recovered; spontaneous pneumothorax of the autologous lungs occurred in two patients, who underwent reoperation but finally died 74 days and 77 days after the transplantation, respectively. CONCLUSION: Single lung transplantation is effective for end-stage emphysema. Carefully selected recipients and comprehensive design of the surgical procedures are critical to successful lung transplantation.

[Injection of activated carbon nanoparticles for guiding lymphadenectomy during minimal invasive surgery in lung cancer].

OBJECTIVE: To evaluate the clinical value of activated carbon nanoparticles for guiding lymphadenectomy in lung cancer. METHODS: Fourty-two lung cancer patients were divided into two groups: the control group (22 cases) and experiment group (20 cases) who received activated carbon nanoparticles injection around the tumor either by endoscopic injection or intraoperative subserosal injection. The number of dissected lymph node, black-stained lymph node, positive lymph node and the side effect of the procedure were analyzed, respectively. RESULTS: No severe complication was observed in the experiment group. The operative time was not prolonged significantly in the experiment group either. However, the number of average lymph nodes dissected in the experiment group (25.5) was significantly more than that in the control group (14.6) (P <0.01). CONCLUSION: Local injection of activated carbon nanoparticles around the tumor during surgical exploration is effective, safe and easy to do for guiding lymphadenectomy in lung cancer patient.

[Effect of JAK/STAT pathway activation on high glucose-induced transdifferentiation in renal proximal tubular epithelial cells].

OBJECTIVE: To evaluate the effect of JAK/STAT signaling pathway activation on the transdifferentiation and secretion of transforming growth factor-beta1 (TGF-beta1) induced by high glucose in renal proximal tubular epithelial cells. METHODS: Human kidney cells (HKC) were cultured and then divided into four groups: low glucose (LG) group, high glucose (HG) group, high mannitol (LG + M) group, and HG + AG490 group. Immunoprecipitation and Western blot analysis were used to determine the expression of tryosine phosphorylated Janus kinase 2 ( p-JAK2). The protein expressions of STAT1, STAT3, p-STAT1, and p-STAT3 and the expressions of alpha-SMA and E-Cadherin were observed by Western blot. The contents of TGF-B1, fibronectin and type I collagen in the supernatants of the cultured HKC were detected by enzyme-linked immunosorbent assay (ELISA). The expression of TGF-beta1 mRNA was measured by reverse transcription and polymerase chain reaction (RT-PCR). RESULTS: Compared with LG group, the expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta1, mRNA were significantly increased in HG group from 6 to 72 hours. Meanwhile, the contents of TGF-beta1 and collagen I in the supernatants and the expression of alpha-SMA increased and the expression of E-Cadherin decreased. The expressions of JAK2, p-STAT1, p-STAT3, and TGF-beta mRNA as well as the levels of TGF-beta1 and collagen I in the supernatant s in HG + AG490 group were significantly lower than in the HG group. The expressions of alpha-SMA and E-Cadherin were also decreased in HG + AG490 group. CONCLUSION: Activation of JAK/STAT signaling pathway may be involved in the high glucose-induced transdifferentiation and overproduction of TGF-beta1, and ECM proteins in HKCs.

[Treatment and timing of re-operation for postoperative recurrence of spontaneous pneumothorax].

OBJECTIVE: To investigate the treatment for postoperative recurrence of spontaneous pneumothorax, the feasibility of re-operation, indications and the results. METHOD: The clinical and follow-up data of 28 cases of postoperative recurrence from 485 patients who underwent operations for spontaneous pneumothorax from Jan, 1994 to Jan, 2005 were retrospectively reviewed. RESULTS: One case was observed without any invasive therapy, 12 cases underwent closed pleural drainage and 15 cases received reoperation. All of the patients had the lungs reexpanded sufficiently, with comorbidities in 2 cases, one of which was pleural effusion, the other was prolonged leakage after surgery. No death occurred. The operation time was 80 - 315 (115 +/- 43) min, and the bleeding volume was 50 - 350 (115 +/- 54) ml. The time of chest tube drainage was 1 - 7 (4 +/- 2) d, and the time of hospital stay was 7 - 18 (11 +/- 5) d. The follow-up of the 28 cases ranged from 1 to 107 months (median 55.4) without recurrence. CONCLUSIONS: The findings on lung high rate CT (HRCT) are the most important factors in deciding treatments of postoperative recurrence of pneumothorax. If it is the first recurrence, and there is no evident bullae on HRCT, conservative therapy should be considered, especially for the recurrence within two years postoperation. If the first recurrence occurs after surgery, especially within 2 years, and the bullae is invisible on HRCT, adhesion is the choice without significant adverse effect. If the recurrence occurred twice and more, bullae is found on HRCT, adhesion hampered lung reexpansion, or pleural drainage alone could not work, re-operation should be performed.

[The management of the contralateral lungs in four cases with single allograft lung transplantation].

OBJECTIVE: To report the management of the contralateral lungs in 4 cases with single allograft lung transplantation. METHODS: Four cases receiving lung transplantation were analyzed respectively. One presented with bilateral multiple lung cysts and three with chronic obstructive pulmonary disease (COPD) with bilateral bullae. In the case with bilateral multiple cysts, the contralateral lung remained untreated after operation. For the contralateral lungs in the three cases with COPD, one remained untreated, one received lung volume reduction surgery (LVRS) immediately after lung transplantation, and one received LVRS 47 days after lung transplantation. RESULTS: Three patients recovered after operation, and 2 of them survived more than 18 months. One patient with delayed contralateral LVRS died 74 days after lung transplantation. CONCLUSIONS: For advanced stage COPD with bilateral bullae, contralateral LVRS may be performed immediately after single lung transplantation. In patient with bilateral cysts only, the resection of the contralateral cysts may be avoided if there is no severe infection.