[Effect of changes in posterior tibial slope on the mid-term clinical outcomes of Oxford unicompartmental knee arthroplasty].

Objective: To investigate the impact of changes in the posterior tibial slope (PTS) in Oxford unicompartmental knee arthroplasty (OUKA) on the mid-term clinical outcomes of postoperative patients. Methods: This study was a follow-up study. The data of 135 patients (150 knees) who underwent OUKA at the China-Japan Friendship Hospital from January 2012 to January 2013 were analyzed retrospectively. The patients were followed-up for at least ten years. According to the changes in PTS of the medial tibial plateau before and after surgery, patients were divided into three groups: group A (PTS decreased by more than 5°), group B (PTS changed by 5° or less), and group C (PTS increased by more than 5°). The Knee Society Clinical Score (KSS-C), Knee Society Functional Score (KSS-F), Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and knee range of motion (ROM) among the three groups were compared at the last follow-up. Results: Prior to the final follow-up assessment, six patients expired, and an additional nine patients were lost to follow-up. A total of 120 patients (135 knees) were enrolled in this study (30 males and 90 females). The mean age was (66.29±8.62) years, and the follow-up time was (10.54±0.72) years. Group A consisted of 32 patients (34 knees), group B comprised 77 patients (90 knees), and group C included 11 patients (11 knees). One knee in group A suffered prosthesis loosening, and two knees in group C experienced postoperative bearing dislocation, one knee encountered bearing fragmentation. The incidence of postoperative complications differed significantly among the three groups (P<0.05). The preoperative OKS was (33.91±6.59) points, KSS-F was (43.46±8.99) points, KSS-C was (41.05±5.70) points and ROM was 115.23°±13.53°; after the surgery, they changed to (18.82±7.01) points, (81.51±7.34) points, (82.64±7.94) points, and 119.07°±8.62°, respectively, and all the differences were statistically significant (all P<0.001). In terms of postoperative outcomes, group A had an OKS of (21.44±8.46) points and a FJS of (63.83±11.40) points, group B had an OKS of (17.07±5.81) points and a FJS of (70.49±12.45) points, group C had an OKS of (25.09±5.07) points and a FJS score of (59.48±10.09) points; the differences among the three groups were all statistically significant (all P<0.05), but there were no significant differences in the postoperative KSS scores and ROM among the three groups (all P>0.05). Conclusions: After OUKA, better mid-term clinical outcomes are achieved when ΔPTS is<5°. Although the recommended central value for PTS in OUKA is 7° according to Oxford, it should be individualized, and it is recommended to consider the preoperative angle, with a change of less than 5° before and after surgery.

[Correlational between the gap contact force and the degree of lower limb alignment correction in Oxford mobile bearing unicompartmental knee arthroplasty].

Objective: To study the correlation between joint contact force and postoperative lower extremity alignment in Oxford unicompartmental knee arthroplasty (OUKA) and provide reference data for predicting the lower extremity alignment after OUKA. Methods: It was a retrospective case series study. A total of 78 patients (92 knees) who underwent OUKA surgery from January 2020 to January 2022 in the Department of Orthopedics and Joint Surgery of China-Japan Friendship Hospital were included in this study, including 29 males and 49 females, aged (68.8±6.9) years. A custom-designed force sensor was used to measure gap contact force in the medial gap of OUKA. The patients were divided into groups according to the varus degree of lower limb alignment after operation. Relationship between the gap contact force and the alignment of the lower limbs after operation was analyzed with Pearson correlation analysis, and the gap contact force was compared between patients with different lower limbs alignment correcting results. Results: The mean contact force measured during the operation at 0° of knee extension was 81.7 N±57.8 N, and it was 96.1 N±54.5 N at 20° of knee flexion. The average postoperative knee varus angle was 2.9°±2.7°. The gap contact force at the 0° and 20° positions of the knee joint was negatively correlated with the varus degree of the postoperative lower limb alignment (r=-0.493, -0.331, both P<0.001). The distribution of gap contact force at 0° was different in each group, the contact force [M (Q1, Q3)] of the neutral position group(n=24) was 117.4 N (31.7 N, 233.0 N), and it was 63.7 N (11.3 N, 209.0 N), 31.5 N (8.3 N, 87.7 N) in the mild varus group (n=51) and the significant varus group (n=17), respectively, and the difference was statistically significant (P<0.001); while at 20°, only the difference between the significant varus group and the neutral position group was statistically significant (P=0.040). The gap contact force of the alignment satisfactory group at 0° and 20° was greater than those in the significant varus group (both P<0.05). The gap contact force measured at 0° and 20° was significantly greater in patients with preoperative significant flexion deformity than in patients without flexion deformity (or mild flexion deformity) (both P<0.05). Conclusions: OUKA gap contact force is related to the degree of lower limb alignment correction after the operation. In patients with well-corrected lower limb alignment after surgery, the median intraoperative knee joint gap contact force at 0° and 20° is 117.4 N and 92.5 N, respectively.

[Clinical results of medial mobile bearing unicompartmental knee arthroplasty using kinematic alignment technique with at least 5-years follow-up].

Objective: To evaluate the mid-term results of kinematic alignment technique in Oxford mobile bearing unicompartmental knee arthroplasty (OUKA). Methods: The clinical data of first 98 knees OUKA performed from June 2015 to January 2017 using kinematic alignment technique with at least 5-year follow-up were retrospectively analyzed, including 28 knees in 24 males and 70 knees in 62 females. The mean surgical age was (68.4±8.0) years. The clinical data of patients before operation and at the last follow-up were recorded and compared. The knee Hospital for Special Surgery (HSS) score, visual analogue scale (VAS) of pain, range of motion, surgical complications and radiological assessment were analyzed to evaluate the efficacy of kinematic alignment technique in OUKA. Results: The mean follow-up was (70.9±5.9) months (60-81 months). The mean operation time was (56.4±9.1) minutes. There was no conversion to total knee replacement, no collateral ligament injury and no fracture in operation. The postoperative hospital stay was (5.8±1.9) days. Postoperative hemoglobin drop was (12.7±5.5) g/L. There was no blood transfusion. No patient died during perioperative period. No serious adverse events related to surgery occurred after operation, such as pulmonary embolism, fat embolism, cardio-cerebrovascular accident, etc. No revision, bearing dislocation, periprosthetic joint infection, prosthesis aseptic loosening, contralateral compartment arthritis progression occurred at final follow-up. Three patients reported persistent unexplained knee pain. Afther the operation, the HSS score increased from 59.1±8.2 to 91.8±5.6 after the operation, the range of motion increased from 122.4°±10.0° to 125.6°±7.1°, and the VAS score decreased from 6.9±0.8 to 1.6±1.2 (all P<0.05). Radiological assessment showed that 92.9%(91/98) implant positions were ideal and 7 knees were outliers. The mean HKAA was 173.3°±3.7° before surgery and it was 177.2°±3.0° after surgery (P=0.038). The mean A angle of femur varus/valgus angle was 2.0°±2.8° (-11°-13°), and the mean B angle of femur flexion/extension angle was 4.8°±3.4°(0°-17°). The mean tibia valgus/valgus angle E angle was 1.0°±1.9°(-4°-9°), and the mean F angle was 6.7°±2.3°(1°-12°). The mean postoperative prosthesis distance was (4.29±2.46)mm(2-7 mm). Conclusions: It's demonstrated that the kinematic alignment technique follows the design principle of OUKA, has satisfactory mid-term results. The radiological assessment of the prosthesis is acceptable.

[Exploration on appropriate fetal weight of twin pregnancies at different gestational weeks and pregnancy complications and outcomes].

Objective: To explore the appropriate fetal weight of twin pregnancies at different gestational weeks and the association with pregnancy complications and outcomes. Methods: Fetal weight at different gestational weeks and related pregnancy complications and outcomes from 1 225 twin pregnancies, who gave birth at Peking University First Hospital from January 2004 to December 2020, were analyzed in this study, including hypertensive disorders in pregnancy, gestational diabetes mellitus (GDM), fetal growth restriction (FGR), fetal distress, preterm birth and neonatal asphyxia. The appropriate fetal weight of twin pregnancies at different gestational weeks were analysed based on the information from 616 twin pregnancies without complications (except preterm birth), and were expressed as P10~P90. The chi-square test was used to compare the risk of pregnancy complications and adverse outcomes in large for gestational age (LGA), appropriate for gestational age (AGA) and small for gestational age (SGA) twin pregnancies and the difference in incidence of pregnancy complications and adverse outcomes in different years. Results: The appropriate fetal weights of normal twin pregnancies at 28 to 37 weeks and 38-40 weeks of gestation were 910-1 255 g, 996-1 518 g, 1 105-1 785 g, 1 295-1 825 g, 1 336-2 000 g, 1 754-2 321 g, 1 842-2 591 g, 1 913-2 615 g, 2 150-2 847 g, 2 350-3 130 g and 2 450-3 250 g, respectively. The incidences of hypertensive disorders in pregnancy, FGR, fetal distress and neonatal asphyxia related to SGA twin pregnancies were significantly higher than AGA twin pregnancies (all P<0.05). The incidence of GDM in twin pregnant from 2017 to 2020 was higher than that from 2004 to 2009 or from 2010 to 2016, but the incidence of fetal distress and neonatal asphyxia were lower than those from 2010 to 2016, and the differences were statistically significant (all P<0.05). Conclusions: The appropriate weights of twin fetuses at different gestational weeks are different from singleton. The incidence of pregnancy complications and adverse outcomes in AGA fetuses is significantly lower than that in SGA fetuses under the specific weight standard for twin fetuses, which could provide a practical basis for clinical management of twin pregnancy.

[Comparison of four-coagulation-tests values in normal pregnant women during early and late pregnancy and the influence of age].

Objective: To explore and compare the reference ranges of four coagulation tests in normal pregnant women during early and late pregnancy and the influence of age. Methods: Values of four coagulation tests from 4 974 pregnant women, who gave single birth at Peking University First Hospital, Obstetrics and Gynecology Hospital of Fudan University, West China Second University Hospital, Peking University Third Hospital and Shengjing Hospital of China Medical University from February 2017 to July 2020, were measured and analyzed in this study, including prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and thrombin time (TT). The four normal reference ranges of coagulation during early and late pregnancy phases were expressed as P2.5-P97.5. The difference of two pregnancy phases was compared by non-parametric test of two related samples. And the difference between pregnant women of advanced and non-advanced age in the same pregnancy phase was compared by independent sample non-parametric test. Chi-square test was used to compare the incidence of pregnancy complications in different coagulation reference ranges. Results: The reference ranges of PT of normal pregnant women's early and late pregnancy were 10.0-13.9 s and 9.6-12.3 s, the reference ranges of APTT were 22.6-35.3 s and 22.4-30.9 s, the reference ranges of Fib were 2.4-5.0 g/L and 3.0-5.7 g/L, the reference ranges of TT were 12.0-19.0 s and 11.5-18.4 s. Compared with early pregnancy, PT, APTT and TT shortened significantly, while the Fib significantly increased in late pregnancy (all P<0.001). PT, APTT and TT of advanced and non-advanced age pregnant women were significantly different (all P<0.01). Compared with the ranges of non-pregnant population, more pregnant women were included in the normal pregnant reference ranges of PT in early pregnancy and APTT in the early and late pregnancy, while the incidence of pregnancy complications had no significant differences (all P>0.05). The incidence of fetal distress was higher and the incidence of preterm birth was lower in the reference range of PT in late pregnancy. The incidence of gestational diabetes mellitus was higher in the early and late gestational Fib reference ranges, and the incidence of hypertensive disorders in pregnancy was higher in the late gestational Fib reference range (all P<0.05). Conclusions: The coagulation function of pregnant women increases significantly with the growth of pregnancy, and there is a significant difference between advanced significantly and non-advanced age pregnant women. The recommended ranges of normal pregnant women's early and late pregnancy PT are 10.0-13.9 s and 9.6-12.3 s, the recommended ranges of APTT are 22.6-35.3 s and 22.4-30.9 s, the recommended ranges of TT are 12.0-19.0 s and 11.5-18.4 s. The appropriate ranges of normal pregnant women's early and late pregnancy Fib still need further exploration.

[The association of posterior tibial slope changes between joint gap contact force and the range of motion in Oxford mobile bearing unicompartmental knee arthroplasty].

Objective: To investigate the correlation between the change of posterior tibial slope (PTS) after unicompartmental knee arthroplasty (UKA) and the contact force at the end stage of knee flexion and extension, as well as the postoperative range of motion. Methods: The data of 38 cases (46 knees) of UKAs undertaken in China-Japan Friendship Hospital from June 2020 to June 2021 were analyzed in this study. A custom-designed force sensor was used to measure gap contact force in the medial gap of UKA. The correlations between each two of the three factors-the change of PTS (∆PTS), the gap contact force of full extension and deep flexion and the range of knee motion were analyzed. Results: Totally of 38 patients (46 knees) were enrolled, including 14 males and 24 females, aged (69.1±7.4) years, with an average follow-up of (11.2±3.7) months. The average gap contact force was (88.3±40.6)N, the adjusted contact force of the full extension gap was 81.7%±33.8%, while that of the deep flexion gap was 55.6%±31.0%. At the last follow-up, the fixed flexion degree[M(Q1, Q3)] was 0°(0°, 3°), which was significantly lower than the preoperative value of 0°(0°, 5°) (P<0.05); the postoperative max flexion degree was 115.9°±16.4°, it was increased when compared with the preoperative value of 112.0°±16.8° (P<0.05); and the postoperative PTS was 8.3°±2.7°, and there was no significant difference with the preoperative value (8.6°±2.1°,P>0.05). There was a positive correlation between ∆PTS and both the contact force of full extension gap and the fixed flexion degree (r=0.334 and 0.317, P<0.05). Besides, there was a negative correlation between ∆PTS and the contact force of the deep flexion gap (r=-0.397, P<0.05). However, the correlations between these two factors and the max flexion degree were not significant (P>0.05). Conclusions: The reduction of PTS in UKA would reduce the contact force of the full extension gap, as well as the postoperative fixed flexion deformity. Besides, it could increase the contact force of the deep flexion gap, but would not influence the max flexion degree of the knee postoperatively.

[Effect of glucose on Akt2 mRNA and methylation level and the association between early-pregnancy Akt2 mRNA level in peripheral blood and pre-pregnancy BMI and GDM].

Objective: To explore the effect of glucose on Akt2 gene methylation and mRNA level in the trophoblast cell line HTR8/SVneo and the association between first-trimester Akt2 mRNA level in peripheral blood and pre-pregnancy body mass index (BMI) and gestational diabetes mellitus (GDM). Methods: The cell model of intrauterine hyperglycemia in pregnant women with GDM was established, and divided into 5 groups based on the different glucose concentrations (2.5, 5.0, 10.0, 25.0, and 40.0 mmol/L). The mRNA levels of Akt2 gene were detected by real-time quantitative PCR, and the methylation levels of Akt2 gene promoter region were detected by mass spectrometry. According to pre-pregnancy BMI and diagnosis of GDM, 60 pregnant women who had given birth at Peking University First Hospital during December 2014 to July 2016 were classified into overweight non-GDM group, overweight GDM group, obese non-GDM group and obese GDM group. Real-time quantitative PCR analyses were used to detect the levels of Akt2 mRNA in first-trimester peripheral blood of the 4 groups. Results: (1) Level of Akt2 mRNA significantly rose with the glucose concentration of medium increased, showing concentration dependency (all P<0.05). Compared with the 25.0 mmol/L group, the following methylation levels changed significantly (all P<0.05): cytosine-phosphate-guanine (CpG) 10, CpG23, and CpG24.5 of Akt2 gene promoter region in the 5.0 mmol/L group, CpG23 and CpG24.5 in the 2.5 mmol/L group, and CpG10 in the 10.0 mmol/L group. Compared with the 5.0 mmol/L group, CpG10 in the 40.0 mmol/L group showed methylation change (P<0.05). (2) Compared with the overweight non-GDM group [1.04(0.90~1.26)], overweight GDM group [2.10(1.85~2.28)] and obese GDM group [1.68(0.82~2.43)] all had higher Akt2 mRNA levels and the differences were statistically significant (all P<0.05). Compared to obese GDM group [1.68(0.82~2.43)], the level of Akt2 mRNA was higher in overweight GDM group [2.10(1.85~2.28)] and lower in obese non-GDM group [1.00(0.71~2.17)], but the differences were not statistically significant (all P>0.05). Conclusions: Glucose might affect Akt2 mRNA level by changing the methylation of Akt2 gene promoter region, and the change might appear in the first trimester of pregnant women with GDM, especially for women with lower pre-pregnancy BMI.

[Efficacy and safety of compound betamethasone cocktail therapy in primary unilateral unicompartmental knee arthroplasty].

Objective: To evaluate the efficacy and safety of an intraoperative betamethasone periarticular injection in patients undergoing primary unicompartmental knee arthroplasty (UKA). Methods: Seventy patients with knee anteromedial osteoarthritis who underwent the primary unilateral UKA in China-Japan Friendship Hospital from July 2017 to October 2018 were randomized into two groups with random number table. In the group A, an analgesic mixture of morphine, ropivacaine, epinephrine, ketorolac and betamethasone was infiltrated intraoperatively into the soft tissue. While in the group B, a same volume of mixture without betamethasone was injected alternatively. The visual analogue scale (VAS) of pain and analgesic consumption were evaluated to compare the effectiveness of pain control between the two groups. In addition, maximal flexion of the knee andinitial time of the straight leg raising were monitored. Complications were assessed too. The data were compared with independent-sample t test. Results: No significant differences in VAS score was found between the groups at 6 h and 12 h after the operation (t=-1.154, -1.108, both P>0.05), but the pain level and analgesic consumption were significantly lower in the group A from 18 h to 72 h post operation (t=-2.959, -2.808, -2.080, -2.519, -3.378, -3.237, all P<0.05). The maximal flexion in group A was significantly higher than that in the group B from 1 d to 3 d (t=2.985, 4.575, 4.013, all P<0.05). The straight leg raising ability and incidence of complications were similar between the groups (χ(2)=0.141, 0.000, both P>0.05). Conclusions: The cocktail analgesics injection containing small dose of betamethasone during UKA can provide effective acute pain control early after the surgery, which is conducive to knee joint function, and it does not increase the incidence of postoperative complications.

[Present situation on non-invasive assessment of liver fibrosis/cirrhosis].

Patients with chronic liver disease often have varying degrees of hepatic fibrosis, and further exacerbations can lead to cirrhosis and even hepatocellular carcinoma. Liver biopsy is the gold standard for the diagnosis of liver fibrosis/cirrhosis, but there are still many limitations. In recent years, non-invasive assessments for liver fibrosis/cirrhosis have gained rapid development. Of these techniques, two different approaches have been validated in clinical practice: imaging methods based on the measurement of liver stiffness, and biological methods based on the serum biomarkers. The two different approaches can complement each other. Current non-invasive assessments for liver fibrosis/cirrhosis tend to be reliable for the detection of advanced fibrosis and cirrhosis, but often lack to distinguish the different early stage of liver fibrosis. Further improving the accuracy of non-invasive assessments might play an important role for clinical management of liver diseases.

Wavelength modulation technique-based photoacoustic spectroscopy for multipoint gas sensing.

A multipoint gas sensing scheme based on photoacoustic spectroscopy was proposed. Multiple photoacoustic spectroscopy (PAS) gas cells (resonant frequency f0=5.0 kHz) were connected in series for the multipoint gas sensing with wavelength modulation technique. The PAS signal was excited by modulating the tunable distributed feedback laser diode wavelength at f0/2 using a changing driving current. The gas concentration of each gas cell was obtained by the PAS signal, which was demodulated by the lock-in amplifier. A multipoint PAS experiment to detect the water vapor at 1368.597 nm was implemented to verify the scheme we presented. With the three PAS gas cells, the linear response to the water vapor concentration of our sensors achieved 0.9978, 0.99591, and 0.99617, and their minimum detection limits were 479, 662, and 630 ppb, respectively.

[Influence of tibial component slope on short-term clinical outcome for Oxford unicompartmental knee arthroplasty].

Objective: To investigate the effects of tibial component slope change after microplasty (MP) Oxford unicompartmental knee arthroplasty (UKA) on short-term clinical outcome. Methods: A total of 116 patients(128 UKAs)underwent UKA in Department of Orthopaedic Surgery of China-Japan Friendship Hospital between January 2014 and December 2015 were retrospectively reviewed. Totally 100 patients (108 UKAs) were finally included in the study. There were 31 males and 69 females, aging from 47 to 90 years (mean 67.2 years). The mean height was (161.9±8.4) cm and the mean body mass index (BMI) was (26.2±3.3) kg/m(2). The posterior tibial slope (PTS) at preoperative and postoperative were measured on the lateral radiograph. The postoperative PTS were divided into five groups (<3°, 3° to 5°, 5° to 7°, 7° to 9° and>9°). The Oxford Knee Score (OKS) was recorded. Pearson correlation analysis, ANOVA and t test were used to analyze data. Results: All operations were successfully accomplished and there were no transfusion, infection, thrombus and other complications. There was 1 patient accepted revision because of bearing dislocation. Compared to preoperative, the PTS decreased (6.5°±2.2° vs.9.6°±3.4°) postoperative, there was statistical difference (t=9.053, P<0.01). Only 3 patients were beyond the recommended range (2° to 12°). A total of 82 patients (86 UKAs) were followed up. The follow-up time was 1 to 2.9 years (mean 2 years). The OKS was 43.0±4.1 (mean 31 to 48). The PTS increased in 12 patients (12 UKAs) postoperative, the mean OKS was 40.5±5.2. The PTS decreased in 70 patients (74 UKAs), the mean OKS was 43.4±3.8. There were significant difference in OKS (t=2.347, P=0.021). There were no significant difference in OKS between the five groups. There were positive correlation between postoperative PTS and preoperative PTS (r=0.201, 95%CI: 0.001 to 0.396, P=0.037), there were no correlations between postoperative PTS and hight and BMI. There were negative correlations between OKS and postoperative PTS (r=-0.255, 95%CI: -0.063 to -0.427, P=0.018) and PTS change (r=-0.292, 95%CI: -0.08 to -0.475, P<0.01). Conclusions: Satisfying PTS can be obtained by use of Oxford MP instrumentation. The clinical outcome of the postoperative PTS decreased was relatively better. Too large posterior slope of the tibial implant should be avoided.

[Individual difference of coronal bowing of femur and its influence on the lower limbs alignment after the total knee arthroplasty].

Objective: To disclose the correlation between the femur bowing angle(FBA) and vulgas correction angle(VCA), anlysys its influence on the total knee arthroplasty and the lower limbs alignment. Methods: From Janurary 2013 to December 2015, 699 patients who had received total knee arthroplasty(TKA)were collected in the Department of Joint Surgery, China-Japan Friendship. The FBA, VCA, offset of the proximal femur, the lengh of the femur, the neck shaft angle of the femur of the eligible cases from the long leg X-ray were measured.All the data were analysed for the following steps: the FBA's mean value and characteristics of distributation of all the cases; the VCA's mean value and characteristics of distributation of all the cases; correlations between the VCA and the other parameters; divide all the cases into four groups based on the value of FBA : group A(FBA<-3°, 29), group B(-3°≤FBA≤0°, 255), group C(0°3°, 236)and then plan to cut the distal femur with 5° and 6°, respectively. The percent of ideal alignmental outcome's percentage of every group were compared. Results: The mean Value of the FBA is -7.1--12.1(1.4±2.4)°; the mean Value of the VCA is 2.5--11.9(6.5±1.3)°. The correlation index between VCA and FBA, the neck shaft angle of the femur , offset of the hip joint, the lengh of the femur is 0.72, -0.26, 0.45 and -0.08, perspectively. The theoretical ideal alignment percentage of the 5 degree-valgus-bone cut and 6 degree-valgus-bone cut in every group is group A: 89.7% and 66.5%; group B: 93.7% and 95.7%; group C: 71.9% and 94.6%; group D: 21.2% and 50.8%, respectively. Conclusion: The cases whose femur bowing angles are outliers are common in daily medical practice, so the vulgas correction angles need be ajusted for its significant correlation with FBA. 5 degree-valgus-bone cut or 6 degree-valgus-bone cut could not get the ideal alignment some times.

[Study on the health effect of the occupational stress in aircrew].

Objective: To explore the relationship between occupational stress and physiological and biochemical indexes, to research the health effect of the occupational stress in aircrew. Methods: 450 aircrews were conducted with the OSI-R questionnaire survey, examine the level of blood pressure, blood routine, ALT and UA. Results: The concentration of HB was positively related with task conflict and entertainment and leisure (ß=0.262 and 0.106, both P<0.05) , while heavy task, task discomfort and psychological stress reactions were negatively related with HB (ß=-0.163, -0.102, and -0.137, all P<0.05) ; task conflict and self-care were positively related with RBC (ß=0.221 and 0.159, both P<0.01) , heavy task, psychological stress reactions and social support were negatively related with RBC (ß=-0.157, -0.119, and -0.113, all P<0.05) ; task ambiguity and self-care had a positive relationship with ALT (ß=0.144 and 0.159, both P<0.01) while heavy task, psychological stress reactions and social support had a negative relationship with ALT (ß=-0.176, -0.096, and -0.102, all P<0.05) ; self-care was positively related with SBP (ß=0.170, P<0.01) , task discomfort, interpersonal stress reactions and social support were negatively related with SBP (ß=-0.093, -0.103, and -0.111, all P<0.05) ; while self-care was positively related with DBP (ß=0.139, P<0.01) , social support was negatively related with DBP (ß=-0.114, P<0.05) . Conclusion: Occupational stress of the aircrew is significantly related with blood pressure, RBC, ALT and UA, occupational stress can make effects on the health of aircrew.

[Correlation between job burnout and salivary cortisol concentration in employees].

OBJECTIVE: To investigate the correlation between job burnout and salivary cortisol concentration. METHODS: In September 2014, a cross-sectional survey was used to perform a questionnaire survey for 237 employees in a solar photovoltaic company. Meanwhile, saliva was collected through chewing with a tube for saliva collection, and enzyme-linked immunosorbent assay was used to measure salivary cortisol concentration. RESULTS: The salivary cortisol concentration showed no significant differences between employees with different ages, working years, educational backgrounds, and shifts(P>0.05). The salivary cortisol concentration was positively correlated with the scores of emotional exhaustion, depersonalization, and job burnout(r=0.182, 0.229, and 0.222, P<0.05). The employees with emotional exhaustion, depersonalization, and job burnout had significantly higher salivary cortisol concentrations than those without emotional exhaustion, depersonalization, and job burnout(80.22±13.34 µg/L vs 75.86±14.75 µg/L, t=2.029, P<0.05; 80.69±12.99 µg/L vs 75.27±14.89 µg/L, t=2.607, P<0.05; 80.06±12.63 µg/L vs 72.76±16.04 µg/L, t=3.248, P<0.05). The stepwise regression analysis showed that salivary cortisol concentration was mainly influenced by depersonalization. CONCLUSION: Job burnout is correlated with salivary cortisol concentration, and can be used as an objective assessment index for job burnout.

[Correlation between occupational stress and salivary cortisol concentration in employees].

OBJECTIVE: To investigate the influence of occupational stress on salivary cortisol concentration in employees. METHODS: In September 2014, occupational stress evaluation was performed for 186 employees in a solar photovoltaic company, and enzyme-linked immunosorbent assay was used to measure the salivary cortisol concentration. RESULTS: The salivary cortisol concentration showed no significant differences between groups with different demographic features(P>0.05). The group with a high score of job control had a significantly lower salivary cortisol concentration than that with a low score(74.62±15.34 µg/L vs 79.95±12.99 µg/L, P<0.05). The groups with high scores of job danger and job responsibility and burden had significantly higher salivary cortisol concentrations than those with low scores(80.29±9.45 µg/L vs 75.60±16.41, P<0.05; 80.94±10.87 µg/L vs 74.05±16.35 µg/L, P<0.05). The salivary cortisol concentration was positively correlated with the scores of job danger and job responsibility and burden(r=0.176 and 0.252, P<0.05) and negatively correlated with the score of job control(r=-0.208, P<0.05). CONCLUSION: Salivary cortisol concentration is positively correlated with occupational stress and increases with the increasing degree of occupational stress, and can be used as an objective biomarker for the identification and evaluation of occupational stress.

[Correlation between job burnout and salivary immunoglobulin G in employees].

OBJECTIVE: To investigate the influence of job burnout on salivary immunoglobulin G(IgG) concentration in employees. METHODS: In September 2014, evaluation of job burnout was performed for 186 employees in a solar photovoltaic company, and enzyme-linked immunosorbent assay was used to measure salivary IgG concentration. RESULTS: The employees with over 20 working years had a significantly higher salivary IgG concentration than those with ≤15 working years(53.80±8.22 µg/ml vs 49.93±7.97 µg/ml, P<0.05). The employees with long-day shifts had a significantly higher salivary IgG concentration than those with day-night shifts (54.98±7.62 µg/ml vs 51.85±7.94 µg/ml, P<0.05). The employees with depersonalization had a significantly lower salivary IgG concentration than those without depersonalization(50.69±9.89 vs 53.19±6.54, P<0.05). The salivary IgG concentration was negatively correlated with the scores of emotional exhaustion, depersonalization, and job burnout (r=-0.194, -0.152, and -0.210, all P<0.05). CONCLUSION: Job burnout is negatively correlated with salivary IgG concentration, which tends to decrease with the increasing severity of job burnout. Therefore, salivary IgG can be used as a biomarker for the identification and evaluation of job burnout.

[Association between occupational stress and electrocardiographic abnormalities in employees].

OBJECTIVE: To investigate the influence of occupational stress on electrocardiographic features in employees. METHODS: In September 2014, a total of 186 employees in a solar photovoltaic company underwent the evaluation of occupational stress, and the changes in electrocardiographic findings were recorded. RESULTS: The abnormal rate of electrocardiographic findings showed significant differences between different age groups(P<0.05), and the employees older than 50 years had the highest abnormal rate(34.0%). Among the study subjects aged 41-50 years, those with a high score of job responsibility and burden had a higher abnormal rate of electrocardiographic findings than those with a low score(24.3% vs 6.3%); among the study subjects older than 50 years, those with a high risk level had a higher abnormal rate of electrocardiographic findings than those with a low risk level(50.0% vs 22.6%). Among the study subjects older than 50 years, those with a high score of mental health had a significantly lower abnormal rate of electrocardiographic findings than those with a low score (8.3% vs 55.2%, P<0.05); the employees with high scores of physical complaint and daily stress had a higher abnormal rate of electrocardiographic findings than those with low scores of physical complaint and daily stress (52.2% vs 20.0%, P<0.05; 50.0% vs 22.6%, P<0.05). The unconditional multivariate logistic stepwise regression analysis showed that old age was the risk factor for the high abnormal rate of electrocardiographic findings (OR= 1.076, P=0.013), and that mental health was the protective factor for the abnormal rate of electrocardiographic findings(OR=0.356, P=0.017). CONCLUSION: Occupational stress is the risk factor for abnormal electrocardiographic findings, and the abnormal rate of electrocardiographic findings tends to increase with the increasing severity of occupational stress.

Myofibroblastic transformation of rat hepatic stellate cells: the role of Notch signaling and epithelial-mesenchymal transition regulation.

OBJECTIVE: The development of liver fibrosis has been shown to be associated with the transition of quiescent hepatic stellate cells (HSCs) into myofibroblastic HSCs, and the Notch signaling system has been shown to be activated in this process. The Notch signaling pathway is also known to regulate epithelial-mesenchymal transition (EMT). MATERIALS AND METHODS: In the current study, quiescent HSCs were examined for expression of EMT markers, and experiments were performed to determine whether these markers change as quiescent HSCs transition into myofibroblastic HSCs and whether the process is modulated by Notch signaling. To promote myofibroblastic transition under experimental conditions, enzymatic perfusion and density gradient centrifugation were used to isolate rat HSCs, which were then cultured. A γ-secretase inhibitor was used to inhibit Notch signaling pathway activity in primary rat HSCs. RESULTS: Upregulated expression of myofibroblastic markers was observed, but expression of quiescent HSC markers and epithelial markers was downregulated during the transition of HSC in vitro. Data indicate that expression of the classical EMT marker; i.e., E-cadherin, was decreased and that of N-cadherin and snail 1 increased. Notch 2 and Notch 3 receptors and Hey2 and HeyL target genes expression increased significantly as quiescent HSCs transitioned into myofibroblastic HSCs. When Notch signaling was blocked, however, the myofibroblastic transition of HSCs reverted, and epithelial marker expression was restored. CONCLUSIONS: Thus, targeting Notch signaling may provide new insights into the mechanism of HSC transition and may offer a possible therapeutic target for the treatment of hepatic injury.

Porous tantalum rods for treating osteonecrosis of the femoral head.

This study evaluated the outcomes of using porous tantalum rods for the treatment of osteonecrosis of the femoral head (ONFH). We performed core decompression and inserted porous tantalum implants in 149 patients (168 consecutive hips) with ONFH. Hips had large (65), medium (64), or small (39) lesions; 63 lesions were lateral, 68 were central, and 35 were medial. Conversion to total hip arthroplasty (THA) was the end point of this survey. A total of 130 cases (138 hips) were followed. The mean follow-up time was 38.46 ± 5.76 months; 43 hips (31%) were converted to or needed THA. Of the 43 hips requiring THA, 33 had large lesions, including 1 medial, 3 central, and 29 lateral lesions; 9 had medium, lateral lesions, and 1 hip had a small, lateral lesion. Bone grafting was used in 59 hips, with 3 hips failing; 40 of 79 hips without bone grafts failed. The sum distances between the tops of the rods and the lateral lesion boundaries (SDTL, mm) were measured in anteroposterior and lateral radiographs. In the failure and spared groups, the average SDTLs were 7.65 ± 2.759 and 0.83 ± 2.286 mm, respectively. The survival of porous tantalum rods used for treating early-stage ONFH was affected by the size and location of the lesion, whether or not a bone graft was used, as well as the distance between top of the rod and the lateral boundary of the lesion.

Label-free and reagentless electrochemical detection of PCR fragments using self-assembled quinone derivative monolayer: application to Mycobacterium tuberculosis.

We report a signal-on, label-free and reagentless electrochemical DNA biosensor, based on a mixed self-assembled monolayer of thiolated hydroxynaphthoquinone and thiolated oligonucleotide. Electrochemical changes resulting from hybridization were evidenced with oligonucleotide targets (as models), as well as with polymerase chain reaction (PCR) products related to different lineages of Mycobacterium tuberculosis strains. With pure oligonucleotides, this system achieves high sensitivity (∼300 pM of DNA target, i.e. 30 fmol in a 100 µL sample) and excellent selectivity, allowing to detect a single mismatch on a sequence of 20 bases. With PCR products, current changes are specific to the bacterial strain from which the PCR fragment is produced. In addition, the sensor response is of the signal-on type, giving a positive signal change upon hybridization, and therefore does not suffer from false positive responses due to non-specific adsorption of DNA.