Associations between organophosphate esters and bone mineral density in adults in the United States: 2011-2018 NHANES.

BACKGROUND: Organophosphate esters (OPEs) are used extensively as flame retardants and plasticizers. Laboratory studies have shown that OPEs exhibit osteotoxicity by inhibiting osteoblast differentiation; however, little is known about how OPEs exposure is associated with bone health in humans. OBJECTIVES: We conducted a cross-sectional study to investigate the association between OPEs exposure and bone mineral density (BMD) in adults in the United States using data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES). METHODS: Multivariate linear regression models were used to assess the association between concentrations of individual OPE metabolites and BMDs. We also used the Bayesian kernel machine regression (BKMR) and quantile g-computation (qgcomp) models to estimate joint associations between OPE mixture exposure and BMDs. All the analyses were stratified according to gender. RESULTS: A total of 3546 participants (median age, 40 years [IQR, 30-50 years]; 50.11% male) were included in this study. Five urinary OPE metabolites with a detection rate of > 50% were analyzed. After adjusting for the potential confounders, OPE metabolite concentrations were associated with decreased total-body BMD and lumbar spine BMD in males, although some associations only reached significance for bis(1-chloro-2-propyl) phosphate (BCPP), dibutyl phosphate (DBUP), and bis(2-chloroethyl) phosphate (BCEP) (ß = -0.013, 95% CI: -0.026, -0.001 for BCPP and total-body BMD; ß = -0.022, 95% CI: -0.043, -0.0001 for DBUP and lumbar spine BMD; ß=-0.018, 95% CI: -0.034, -0.002 for BCEP and lumbar spine BMD). OPE mixture exposure was also inversely associated with BMD in males, as demonstrated in the BMKR and qgcomp models. CONCLUSIONS: This study provides preliminary evidence that urinary OPE metabolite concentrations are inversely associated with BMD. The results also suggested that males were more vulnerable than females. However, further studies are required to confirm these findings.

Theoretical study on electrocatalytic carbon dioxide reduction over copper with copper-based layered double hydroxides.

The conversion of CO2 into valuable fuels and multi-carbon chemical substances by electrical energy is an effective strategy to solve environmental problems by using renewable energy sources. In this work, the density functional theory (DFT) method is used to reveal the electrocatalytic mechanism of CO2 reduction reaction (CO2RR) over the surface of CuAl-Cl-layered double hydroxides (LDHs) with Cu monoatoms (Cu@CuAl-Cl-LDH), Cu2 diatoms (Cu2@CuAl-Cl-LDH), orthotetrahedral Cu4 clusters (Td-Cu4@CuAl-Cl-LDH) and planar Cu4 clusters (Pl-Cu4@CuAl-Cl-LDH). The active sites, density of states, adsorption energy, charge density difference and free energy are calculated. The results show that CO2RR over all the above five catalysts can generate C2 products. Pl-Cu4@CuAl-Cl-LDH tends to generate C2H5OH, while the remaining four structures all tend to produce C2H4. Cuδ+ favors CO2RR, and Td-Cu4@CuAl-Cl-LDH with a larger positively charged area at the active site has the better electrocatalytic performance among the calculated systems with a maximum step height of 0.78 eV. The selectivity of the products C2H4 and C2H5OH depends on the dehydration of the intermediate *C2H2O to *C2H3O or *CCH; if the dehydration produces *CCH intermediate, the final product is C2H4, and if no dehydration occurs, C2H5OH is produced. This work provides theoretical information and guidance for further rational design of efficient CO2RR catalysts for energy saving and emission reduction.

A DFT study on methanol decomposition over single atom Pt/CeO2 catalysts: the effect of the position of Pt.

Pt/CeO2 catalysts exhibit excellent catalytic performance for the methanol dehydrogenation (MD) reaction. In this work, MD reactions on three systems of Pt1/CeO2(110)), Pt7/CeO2(110), and Pt1/Ce1-xO2(110) are investigated via density functional theory (DFT) calculations. The CH3OH adsorption, electronic structure of the catalyst, and mechanism of methanol decomposition (MD) are systematically calculated. The results reveal that the d-band center of the Pt atom moves away from the Fermi level in the order of Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110), and the order of the activity of the MD reaction is Pt1/CeO2(110) < Pt7/CeO2(110) < Pt1/Ce1-xO2(110). The results of the microkinetic dynamics simulation verify that only Pt1/Ce1-xO2(110) is conducive to the decomposition of methanol at low temperatures (373 K), and the products CO and H2 are easily dissociated from the catalyst surface. This work uncovers that both the small size and the Ce vacancy substituted sites of Pt favor the performance of the Pt/CeO2 catalyst, and provides theoretical guidance for the construction and design of efficient metal-support catalysts for the MD reaction.

Role of sirtuins in metabolic disease-related renal injury.

Poor control of metabolic diseases induces kidney injury, resulting in microalbuminuria, renal insufficiency and, ultimately, chronic kidney disease. The potential pathogenetic mechanisms of renal injury caused by metabolic diseases remain unclear. Tubular cells and podocytes of the kidney show high expression of histone deacetylases known as sirtuins (SIRT1-7). Available evidence has shown that SIRTs participate in pathogenic processes of renal disorders caused by metabolic diseases. The present review addresses the regulatory roles of SIRTs and their implications for the initiation and development of kidney damage due to metabolic diseases. SIRTs are commonly dysregulated in renal disorders induced by metabolic diseases such as hypertensive nephropathy and diabetic nephropathy. This dysregulation is associated with disease progression. Previous literature has also suggested that abnormal expression of SIRTs affects cellular biology, such as oxidative stress, metabolism, inflammation, and apoptosis of renal cells, resulting in the promotion of invasive diseases. This literature reviews the research progress made in understanding the roles of dysregulated SIRTs in the pathogenesis of metabolic disease-related kidney disorders and describes the potential of SIRTs serve as biomarkers for early screening and diagnosis of these diseases and as therapeutic targets for their treatment.

Automated deep-learning system in the assessment of MRI-visible prostate cancer: comparison of advanced zoomed diffusion-weighted imaging and conventional technique.

BACKGROUND: Deep-learning-based computer-aided diagnosis (DL-CAD) systems using MRI for prostate cancer (PCa) detection have demonstrated good performance. Nevertheless, DL-CAD systems are vulnerable to high heterogeneities in DWI, which can interfere with DL-CAD assessments and impair performance. This study aims to compare PCa detection of DL-CAD between zoomed-field-of-view echo-planar DWI (z-DWI) and full-field-of-view DWI (f-DWI) and find the risk factors affecting DL-CAD diagnostic efficiency. METHODS: This retrospective study enrolled 354 consecutive participants who underwent MRI including T2WI, f-DWI, and z-DWI because of clinically suspected PCa. A DL-CAD was used to compare the performance of f-DWI and z-DWI both on a patient level and lesion level. We used the area under the curve (AUC) of receiver operating characteristics analysis and alternative free-response receiver operating characteristics analysis to compare the performances of DL-CAD using f- DWI and z-DWI. The risk factors affecting the DL-CAD were analyzed using logistic regression analyses. P values less than 0.05 were considered statistically significant. RESULTS: DL-CAD with z-DWI had a significantly better overall accuracy than that with f-DWI both on patient level and lesion level (AUCpatient: 0.89 vs. 0.86; AUClesion: 0.86 vs. 0.76; P < .001). The contrast-to-noise ratio (CNR) of lesions in DWI was an independent risk factor of false positives (odds ratio [OR] = 1.12; P < .001). Rectal susceptibility artifacts, lesion diameter, and apparent diffusion coefficients (ADC) were independent risk factors of both false positives (ORrectal susceptibility artifact = 5.46; ORdiameter, = 1.12; ORADC = 0.998; all P < .001) and false negatives (ORrectal susceptibility artifact = 3.31; ORdiameter = 0.82; ORADC = 1.007; all P ≤ .03) of DL-CAD. CONCLUSIONS: Z-DWI has potential to improve the detection performance of a prostate MRI based DL-CAD. TRIAL REGISTRATION: ChiCTR, NO. ChiCTR2100041834 . Registered 7 January 2021.

The sirtuin family in health and disease.

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

Bioinformatic Analysis Identifying PSMB 1/2/3/4/6/8/9/10 as Prognostic Indicators in Clear Cell Renal Cell Carcinoma.

Renal cancer incidence has been increasing across the world, clear cell renal cell carcinoma (ccRCC) represents the major subtype of renal cancer. The proteasome is involved in onset, metabolism and survival of tumor and has been recognized as a therapeutic target for various malignancies, while the role of ß subunits of proteasome, PSMB gene family, in ccRCC has not been fully unveiled. Herein we investigated the expression and the prognostic role of PSMBs in ccRCC by analyzing a series of databases, including ONCOMINE, UALCAN, cBioPortal, STRING, GEPIA, GO and KEGG. Over-expressions of PSMB1/2/4/7/8/9/10 mRNA were found in ccRCC tissues compared to normal tissues, transcriptional levels of PSMB2/3/4/6/8/9/10 were significantly positively associated with patients' individual cancer stages and grades. Similar or higher levels of proteins encoded by PSMB1/2/3/7/8/9/10 were observed in tumor tissues compared to normal renal tissues. Further, high mRNA levels of PSMB1/2/3/4/6/10 were correlated with shorter overall survival in univariate analysis. Taken together, the results of our analysis implied that overexpression of PSMB1/2/3/4/6/8/9/10 were indicative of worse prognosis of ccRCC. However, further researches were required to validate our findings.

Surveillance on schistosomiasis in five provincial-level administrative divisions of the People's Republic of China in the post-elimination era.

BACKGROUND: The People's Republic of China (P. R. China) has made significant progress on schistosomiasis control. Among the 12 provincial-level administrative divisions (PLADs) with schistosomiasis endemic in P. R. China, Guangdong, Shanghai, Fujian, Guangxi and Zhejiang PLADs (following as five PLADs) had successively eliminated schistosomiasis during 1985-1995. However, consolidation of the schistosomiasis elimination in these five PLADs remains challenging. In the current study, we sought to understand the epidemic situation in these post-elimination areas and their surveillance capabilities on schistosomiasis. METHODS: Annual data reflecting the interventions and surveillance on human beings, cattle and snails based on county level from 2005 to 2016 were collected through the national schistosomiasis reporting system and the data were analyzed to understand the epidemic status of schistosomiasis in the five PLADs. A standardized score sheet was designed to assess the surveillance capacity for schistosomiasis of selected disease control agencies in five PLADs and ten counties. Assessment on surveillance capacity including schistosomiasis diagnostic skills, identification of snails' living and infection status and knowledge about schistosomiasis and its control were made. Descriptive analysis was used to analyze the epidemic status and evaluation results on surveillance capacities. RESULTS: The assessments showed that no local cases in humans and cattle or infected snail were found in these five PLADs since 2005. However, from 2005 to 2016, a total of 221 imported cases were detected in Zhejiang, Shanghai and Fujian, and 11.98 hm2 of new snail habitats were found in Zhejiang, Shanghai and Guangxi. In addition, snail infestation reoccurred in 247.55 hm2 of former snail habitats since 2011. For the surveillance capacity assessment, the accuracy rate of IHA and MHT were 100 and 89.3%, respectively. All participants could judge the living status of snails accurately and 98.1% on the infection status of snails. The accuracy rate of the questionnaire survey was 98.0%. CONCLUSIONS: Elimination of schistosomiasis was consolidated successfully in five PLADs of P. R. China due to effective and strong post-elimination surveillance. Comprehensive consolidation strategies should be focused on the elimination of residual snails and the prevention of imported infection sources to consolidate the achievements of schistosomiasis control.

Preventive treatment with ginsenoside Rb1 ameliorates monocrotaline-induced pulmonary arterial hypertension in rats and involves store-operated calcium entry inhibition.

CONTEXT: Ginsenoside Rb1, the main active ingredient of ginseng, exhibits ex vivo depression of store-operated calcium entry (SOCE) and related vasoconstriction in pulmonary arteries derived from pulmonary hypertension (PH) rats. However, the in vivo effects of ginsenoside Rb1 on PH remain unclear. OBJECTIVE: This study explored the possibility of using ginsenoside Rb1 as an in vivo preventive medication for type I PH, i.e., pulmonary arterial hypertension (PAH), and potential mechanisms involving SOCE. MATERIALS AND METHODS: Male Sprague-Dawley rats (170-180 g) were randomly divided into Control, MCT, and MCT + Rb1 groups (n = 20). Control rats received only saline injection. Rats in the MCT + Rb1 and MCT groups were intraperitoneally administered single doses of 50 mg/kg monocrotaline (MCT) combined with 30 mg/kg/day ginsenoside Rb1 or equivalent volumes of saline for 21 consecutive days. Subsequently, comprehensive parameters related to SOCE, vascular tone, histological changes and hemodynamics were measured. RESULTS: Ginsenoside Rb1 reduced MCT-induced STIM1, TRPC1, and TRPC4 expression by 35.00, 31.96, and 32.24%, respectively, at the protein level. SOCE-related calcium entry and pulmonary artery contraction decreased by 162.6 nM and 71.72%. The mean pulmonary artery pressure, right ventricle systolic pressure, and right ventricular mass index decreased by 19.5 mmHg, 21.6 mmHg, and 39.50%. The wall thickness/radius ratios decreased by 14.67 and 17.65%, and the lumen area/total area ratios increased by 18.55 and 15.60% in intrapulmonary vessels with 51-100 and 101-150 µm o.d. CONCLUSION: Ginsenoside Rb1, a promising candidate for PH prevention, inhibited SOCE and related pulmonary vasoconstriction, and relieved MCT-induced PAH in rats.

The Undervalued Effects of Polychlorinated Biphenyl Exposure on Breast Cancer.

The incidence of breast cancer across the world has been on the rise in recent decades. Because identified risk factors can only explain a relatively small portion of the cases, environmental exposure to organic pollutants is suspected to play a role in breast cancer etiology. Polychlorinated biphenyls (PCBs) are among the most abundant pollutants, and the impact of their exposure on breast cancer risk has been extensively studied in recent decades. However, the results of most epidemiologic studies do not support an association between PCB exposure and breast cancer risk. We hypothesized that the effects of PCBs on breast cancer might have been undervalued for reasons such as insufficient recognition of the confounding effects of several factors and lack of attention on the innate heterogeneity of PCB mixtures or breast cancer. After reviewing the evidence in the existing literature, we concluded that early life exposure, known risk factors of breast cancer, and impact of exposure to other pollutants are the main sources of confounding effects and have potentially masked the associations between PCBs and breast cancer. Because PCBs are mixtures of congeners with varied properties, and because breast cancers of different subtypes are etiologically distinct diseases, the absence of stratified subgroup analysis on individual PCBs and patients with specific biological subtypes and insufficient attention paid to the results of these subgroup analyses may result in an underestimation of the correlations between PCBs and breast cancer. In future studies, these factors must be taken into consideration when exploring the effect of PCB exposure on breast cancer risk.

Neoadjuvant endocrine therapy: A potential strategy for ER-positive breast cancer.

A potential strategy for patients with estrogen receptor (ER)-positive breast cancer is necessary to replace neoadjuvant chemotherapy which has limited benefit. Neoadjuvant endocrine therapy (NAE) has been indicated to be a favorable alternate approach to downstage large or locally advanced breast cancer in ER-positive, human epidermal growth factor receptor 2 (HER2)-negative (ER+/HER2-) patients, especially postmenopausal women. Previous studies have demonstrated the efficacy of various endocrine agents in NAE. Aromatase inhibitors (AIs) have proven superiority over tamoxifen as a suitable choice to optimize treatment efficacy. Fulvestrant was recently reported as an effective agent, similar to AIs. Furthermore, the addition of targeted agents exerts synergistic antiproliferative effects with endocrine agents and rapidly improves response rates in both endocrine sensitive and resistant tumors. The neoadjuvant platform provides a unique opportunity to define the appropriate strategy and address the mechanisms of endocrine resistance. In addition, the predictive value of biomarkers and genomic assays in NAE is under investigation to evaluate individual effects and validate biomarker-based strategies. In this review, we discuss the most relevant evidence on the potential of NAE for ER+ breast cancer. The current understanding also offers new insights into the identification of the optimal settings and valuable predictive tools of NAE to guide clinical treatment decisions and achieve beneficial therapeutic effects.

Prognostic value of preoperative hyponatremia in patients with epithelial ovarian cancer.

Hyponatremia is an emerging issue in cancer patients. However, few studies have explored the prognostic value of preoperative hyponatremia in epithelial ovarian cancer (EOC) patients. We conducted a retrospective study of women diagnosed with EOC at Shengjing Hospital from 2011 to 2015. Preoperative serum sodium levels were measured and classified as normal (136-145 mmol/L) or hyponatremic (≤135 mmol/L) according to the average/most recent measurements of this biomarker. Multivariable Cox proportional hazard regression models were applied to determine the adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for the association of preoperative hyponatremia with progression-free survival (PFS) and overall survival (OS). We identified 607 EOC patients meeting the inclusion criteria with a median age of 51 years (inter-quartile range: 47-59 years). The median follow-up duration was 3.1 years (inter-quartile range: 2.2-4.2). The recurrence and mortality rates were 56.8% (345/607) and 38.4% (233/607), respectively. Among the patients, 81 (13.3%) were observed as hyponatremic. Preoperative hyponatremia was associated with poorer PFS (HR=1.51; 95%CI=1.07-2.15) as well as OS (HR=1.47; 95%CI=1.03-2.11) after adjusting for potential confounders. Notably, results were in line with the main findings only when using the most recent serum sodium levels before treatment, with corresponding HRs of 1.58 (95%CI=1.12-2.23) for PFS and 1.45 (95%CI=1.02-2.07) for OS. Preoperative hyponatremia is an independent prognostic factor of EOC. Further studies are warranted to confirm our findings as well as to determine whether correction of preoperative hyponatremia may alter clinical outcomes in these patients.

Prognostic Influence of the Time Interval between Surgery and Chemotherapy in Epithelial Ovarian Cancer.

The influence of time to chemotherapy (TTC) on recurrence and survival among epithelial ovarian cancer (EOC) patients still remains unknown. This single center retrospective cohort study was conducted on 489 EOC patients who underwent surgery followed by taxane- plus platinum-based chemotherapy in the Shengjing Hospital of China Medical University between 2011 and 2015. The Multivariate cox proportional regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for progression-free survival (PFS) and overall survival (OS) after adjustment for potential confounders. The median follow-up duration was 2.97 years (inter-quartile range from 2.11 to 4.13 years). The recurrence and mortality rate of the all patients was 50.9% (249/489) and 43.6% (213/489), respectively. Having comorbidity, residual disease, ascites, and advanced FIGO stage (III-IV) was associated worse PFS and OS of EOC patients. Compared to TTC less than 14 days, delayed TTC (more than 28 days) was associated with a worse PFS (HR=1.36; 95%CI: 0.96-1.92) and OS (HR=1.38; 95%CI: 0.95-2.00). Notably, in EOC patients with advanced stage, delayed TTC (more than 28 days) was associated with worse PFS (HR=1.51; 95%CI: 1.02-2.24) and OS (HR=1.53; 95%CI: 1.01-2.32) when comparing to TTC less than 14 days. In conclusion, delayed TTC was associated with higher rates of EOC recurrence and survival among these patients with advanced stage. The findings of the present study may provide evidence for gynecologist as well as these ovarian cancer patients to make further decision for the treatment.

ABO Blood Type Has No Impact on Survival in Patients with Epithelial Ovarian Cancer.

Evidence for an association between ABO blood type and epithelial ovarian cancer (EOC) survival has so far been limited and conflictive. This study applied a retrospective cohort and included 627 EOC patients diagnosed at Shengjing Hospital of China Medical University between 2011 and 2015. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) between the ABO blood type and progression-free survival (PFS) and overall survival (OS) of EOC patients were assessed using multivariable Cox proportional regression models. The median follow-up duration was 2.97 years (inter-quartile range from 2.11 to 4.13 years). The recurrence and mortality rates were 41.5% (260/627) and 37.0% (232/627), respectively. Possessing a comorbidity, residual disease, ascites, and advanced FIGO stage (III/IV) were associated with worse PFS and OS of EOC patients. The distribution of blood types O, A, B, and AB among patients was 27.4%, 31.3%, 33.2%, and 8.1%, respectively. Compared with blood type O, none of the blood types (A, B, and AB) were significantly associated with PFS or OS. However, in the stratified analyses, we found borderline significant results for PFS with blood type AB (HR = 0.56, 95% CI = 0.31-1.01) compared with blood type O. No significant differences were observed for blood type A when compared with all non-A blood type cases. This study does not support an association between ABO blood type and EOC survival. Further prospective cohort studies are warranted to confirm our findings.

[Characterization of cadmium uptake kinetics in cadmium pollution-safe rice material.] / æ°´ç¨»é•‰å®‰å ¨ææ–™çš„é•‰å¸æ”¶åŠ¨åŠ›å­¦ç‰¹å¾.

The characteristics of cadmium (Cd) uptake kinetics in a pollution-safe rice variety of D62B were studied in a hydroponic experiment under different Cd levels and stress time, with a common variety Luhui17 as the control. The results showed that Cd uptake in root of D62B was significantly lower than that of Luhui17 under different stress times. The differences in Cd uptake of the two rice varieties increased with the extension of absorption time. Total Cd amount of Luhui17 was 1.3 times as much as that of D62B when the absorption time was 72 h. Meanwhile, the Cd uptake kinetic of the two varieties accorded to Michaelis-Menten equation, and little difference in Michaelis constants (Km) was observed in the two varieties. However, the maximum uptake rate (Vmax) of Luhui17 was 2 times as much as that of D62B. Once the stress time was more than 48 h, the transfer coefficients of D62B was lower than that of Luhui17, and the Cd distribution ratio in root of D62B was much higher, indicating that D62B had greater accumulation ability in root compared with Luhui17. In conclusion, the Cd uptake and transfer ability of D62B were lower than those of Luhui17.

Age and Sex Effects on the Active Stiffness of Vastus Intermedius under Isometric Contraction.

Previously, a novel technique was proposed to quantify the relationship between the muscle stiffness and its nonfatigue contraction intensity. The method extended the measured range of isometric contraction to 100% maximum voluntary contraction (MVC) using an ultrasonic shear wave measurement setup. Yet, it has not been revealed how this relationship could be affected by factors like age or sex. To clarify these questions, vastus intermedius (VI) stiffness of 40 healthy subjects was assessed under 11 step levels of isometric contraction. The subjects were divided into four groups: young males, young females, elderly males, and elderly females (n = 10 for each). In a relaxed state, no significant difference was observed between the male and female subjects (p = 0.156) nor between the young and elderly subjects (p = 0.221). However, when performing isometric contraction, the VI stiffness of males was found to be significantly higher than that of females at the same level (p < 0.001), and that of the young was higher than the elderly (p < 0.001). Meanwhile, for two knee joint angles used, the stiffness measured at a 90° knee joint angle was always significantly larger than that measured at 60° (p < 0.001). Recognizing the active muscle stiffness of VI contributes to body stability, and these results may provide insight into the age and sex bias in musculoskeletal studies, such as those on fall risks.

Assessment of scoliotic deformity using spinous processes: comparison of different analysis methods of an ultrasonographic system.

OBJECTIVE: The purpose of this study was to evaluate the performance of 5 analysis methods in quantifying scoliotic deformity, using the spatial positions of SP tips acquired by a custom-developed ultrasound-based system, with different curve fitting methods and angle metrics in terms of their correlation with Cobb angle, test-retest reliability, vulnerability to digitization errors, and accuracy of identifying end vertebrae and convexity direction. METHODS: Three spinal column dry bone specimens were randomly configured to 30 different scoliotic deformities. Raw spatial data of the SP tips were processed by the following 3 methods: (1) fifth-order polynomial fitting, (2) locally weighted polynomial regression (LOESS) with smoothing parameter (α) = .25, and (3) LOESS with α = .4. Angle between the 2 tangents along the spinal curve with the most positive and negative slopes (ie, posterior deformity angle) and summation of the angles formed by every 2 lines joining 3 neighboring SPs between the end vertebrae (ie, accumulating angle) were computed to quantify scoliotic deformity. Their performances were compared in terms of their correlation with Cobb angle, test-retest reliability, vulnerability to digitization errors, and accuracy of identifying end vertebrae. RESULTS: Posterior deformity angle calculated from the spinal curve constructed by LOESS with α = .4 excelled in every aspect of the comparison (ie, Cobb angle, test-retest reliability, vulnerability to digitization errors, and accuracy of identifying end vertebrae and convexity direction), making it the method of choice of those tested for processing the spatial data of the SP tips in this ultrasonography study using dry bone specimens. CONCLUSIONS: The ultrasound-based system and the LOESS (0.4)-posterior deformity angle method developed for this study offer a viable technology for quantifying scoliotic deformity in a reliable and radiation-free manner. However, further validation using scoliosis subjects is needed before they can be used to quantify spinal deformity in the clinical setting.

Quantifying the passive stretching response of human tibialis anterior muscle using shear wave elastography.

BACKGROUND: Quantifying passive stretching responses of individual muscles helps the diagnosis of muscle disorders and aids the evaluation of surgical/rehabilitation treatments. Utilizing an animal model, we demonstrated that shear elastic modulus measured by supersonic shear wave elastography increases linearly with passive muscle force. This study aimed to use this state-of-the-art technology to study the relationship between shear elastic modulus and ankle dorsi-plantarflexion angle of resting tibialis anterior muscles and extract physiologically meaningful parameters from the elasticity-angle curve to better quantify passive stretching responses. METHODS: Elasticity measurements were made at resting tibialis anterior of 20 healthy subjects with the ankle positioned from 50° plantarflexion to up to 15° dorsiflexion at every 5° for two cycles. Elasticity-angle data was curve-fitted by optimizing slack angle, slack elasticity, and rate of increase in elasticity within a piecewise exponential model. FINDINGS: Elasticity-angle data of all subjects were well fitted by the piecewise exponential model with coefficients of determination ranging between 0.973 and 0.995. Mean (SD) of slack angle, slack elasticity, and rate of increase in elasticity were 10.9° (6.3°), 5.8 (1.9) kPa, and 0.0347 (0.0082) respectively. Intraclass correlation coefficients of each parameter were 0.852, 0.942, and 0.936 respectively, indicating excellent test-retest reliability. INTERPRETATION: This study demonstrated the feasibility of using supersonic shear wave elastography to quantify passive stretching characteristics of individual muscle and provided preliminary normative values of slack angle, slack elasticity, and rate of increase in elasticity for human tibialis anterior muscles. Future studies will investigate diagnostic values of these parameters in clinical applications.

[Analysis of influential factors for job burnout among managers in a joint venture in Guangzhou, China].

OBJECTIVE: To investigate the influential factors for job burnout among the managerial staff in a Sino-Japanese joint venture automobile manufacturer in Guangzhou, China. METHODS: A total of 288 managers in a Sino-Japanese joint venture automobile manufacturer were surveyed using the Occupational Stress Indicator, Maslach Burnout Inventory (MBI), Eysenck Personality Questionnaire, Simplified Coping Style Questionnaire, and Social Support Rating Scale. RESULTS: On the depersonalization dimension, the male managers had significantly higher scores than the female managers. The scores of emotion exhaustion and depersonalization of MBI showed significant differences among the managers with different levels of occupational stress. The path analysis showed that occupational stress, neuroticism, and psychoticism had negative effects on emotion exhaustion, while job satisfaction and utilization of social support had direct positive effects on emotion exhaustion. Occupational stress, psychoticism, and passive coping style had direct negative effects on depersonalization, while job satisfaction, objective support, and utilization of social support had positive effects on depersonalization. Job satisfaction and active coping style had positive effects on sense of personal accomplishment, while passive coping style had a negative effect on sense of personal accomplishment. Personality exerted its effect on social support through coping style and thus on job satisfaction and job burnout. CONCLUSION: Male managers have a greater propensity to depersonalization than their female counterparts. High occupational stress is a risk factor for job burnout. Personality, social support, and coping style are influential factors for job burnout.

Relationship between shear elastic modulus and passive muscle force: an ex-vivo study.

As muscle is stretched, it reacts with increasing passive resistance. This passive force component is important for normal muscle function. Unfortunately, direct measurement of passive muscle force is still beyond the current state-of-the-art. This study aimed to investigate the feasibility of using Supersonic shear wave elastography (SSWE) to indirectly measure passive muscle force. Sixteen gastronomies pars externus and 16 tibialis anterior muscles were dissected from 10 fresh roaster chickens. For each muscle specimen, the proximal bone-tendon junction was kept intact with its tibia or femur clamped in a fixture. Calibration weights (0-400 g in 25 g per increment) were applied to the distal tendon via a pulley system and muscle elasticity was measured simultaneously using SSWE. The measurements were repeated for 3 cycles. The elasticity-load relationship of each tested muscle for each loading cycle was analyzed by fitting a least-squares regression line to the data. Test-retest reliability was evaluated using intraclass correlation coefficient (ICC). Results demonstrated that the relationships between SSWE elasticity and passive muscle force were highly linear for all the tested muscles with coefficients of determination ranging between 0.971 and 0.999. ICCs were 0.996 and 0.985, respectively, for the slope and y-intercept parameters of the regression lines, indicating excellent reliability. These findings indicate that SSWE, when carefully applied, can be a highly reliable technique for muscle elasticity measurements. The linear relationship between SSWE elasticity and passive muscle force identified in the present study demonstrated that SSWE may be used as an indirect measure of passive muscle force.