[Automated cephalometric landmark identification and location based on convolutional neural network]

Objective: To develop an automated landmark location system applicable to the case of landmark missing. Methods: Four and eighty-one lateral cephalograms, which contained 240 males and 241 females, with an average age of (24.5±5.6) years, taken from January 2015 to January 2021 in the Department of Orthodontics, Capital Medical University School of Stomatology, and met the inclusion criteria were collected. Five postgraduate orthodontic students were the annotators to manually locate 61 possible landmarks in 481 lateral cephalograms. Two assistant professors in the department as reviewers performed calibration. Two professors as arbitrators, made final decision. Data sets were established (341 were used as training set, 40 as validation set, and 100 as test set). In this paper, an automatic landmarks identification and location model based on convolutional neural networks (CNN), CephaNET, was developed. The model was trained by feeding the original image into the feature extraction module and convolutional pose machine (CPM) module to locate landmarks with high accuracy using deep supervision. Training set was enhanced to 1 684 images by histogram equalization, cropping, and adjustment of brightness. The model was trained to compare the Gaussian heat maps output from the network with the set threshold to identify landmark missing cases. Test set of 100 lateral cephalograms was used to test the accuracy of the model. The evaluation criteria used were success detection rate of missing landmark, mean radial error (MRE) and success detection rate (SDR) in the range of 2.0, 2.5, 3.0, 3.5 and 4.0 mm. Results: The model identified and located 61 commonly used landmarks in 0.13 seconds on average. It had an average accuracy of 93.5% in identifying missing landmarks. The MRE of our testing set was (1.19±0.91) mm. SDR of 2.0, 2.5, 3.0, 3.5 and 4.0 mm were 85.4%, 90.2%, 93.5%, 95.4%, 97.0% respectively. Conclusions: The model proposed in this paper could adapt to the absence of landmark in lateral cephalograms and locate 61 commonly used landmarks with high accuracy to meet the requirements of different cephalometric analysis methods.

[Early identification and influencing factors of post-traumatic stress disorder in high-stress rescue workers]

Objective: To explore the risk intensity and related influencing factors of post-traumatic stress disorder (PTSD) among high-stress rescue workers, and to provide effective tools for the risk assessment of PTSD in military rescue workers. Method: From June to August 2022, cluster sampling was used to select the high-stress rescue personnel of an Army department as the survey subjects. The acute Stress reaction (ASD) scale and PTSD checklist were used to evaluate the risk of PTSD in military rescue personnel. Multivariate logistic regression were used to analyze the influencing factors of PTSD. Results: The age of 4 460 subjects was (24.38±4.072) years old, including 4 396 males (98.6%). The positive rate of initial screening for ASD was 2.85% (127/4 460). The positive rate of PTSD was 0.67% (30/4 460). Multivariate logistic regression model analysis showed that female, older age, recent trauma exposure history, passive smoking and alcohol consumption were at higher risk of ASD, the values of OR (95%CI) were 4.183 (1.819-9.618), 6.278 (1.363-28.912), 3.094 (1.500-6.379), 2.059 (1.298-3.267) and 2.607 (1.614-4.211), respectively; Lower education level was associated with lower risk of ASD, OR (95%CI) was 0.593 (0.359-0.978); People who are older, thinner, have a history of mental illness, and drink alcohol were at higher risk for PTSD, the values of OR (95%CI) were 20.144 (2.459-165.043), 10.287 (2.218-47.700), 91.104 (8.592-965.980) and 2.866 (1.144-7.180), respectively. Conclusion: Gender, age, education level, passive smoking, alcohol consumption, past history of mental illness and body mass index may be related to the potential risk of PTSD in rescue workers,passive smoking, alcohol consumption, and weight controlling should be focused on to reduce potential risks of PTSD.

Bone marrow mesenchymal stem cell-derived exosomal microRNAs target PI3K/Akt signaling pathway to promote the activation of fibroblasts

BACKGROUND

Fibroblast plays a major role in tendon-bone healing. Exosomes derived from bone marrow mesenchymal stem cells (BMSCs) can activate fibroblasts and promote tendon-bone healing via the contained microRNAs (miRNAs). However, the underlying mechanism is not comprehensively understood. Herein, this study aimed to identify overlapped BMSC-derived exosomal miRNAs in three GSE datasets, and to verify their effects as well as mechanisms on fibroblasts.

AIM

To identify overlapped BMSC-derived exosomal miRNAs in three GSE datasets and verify their effects as well as mechanisms on fibroblasts.

METHODS

BMSC-derived exosomal miRNAs data (GSE71241, GSE153752, and GSE85341) were downloaded from the Gene Expression Omnibus (GEO) database. The candidate miRNAs were obtained by the intersection of three data sets. TargetScan was used to predict potential target genes for the candidate miRNAs. Functional and pathway analyses were conducted using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively, by processing data with the Metascape. Highly interconnected genes in the protein-protein interaction (PPI) network were analyzed using Cytoscape software. Bromodeoxyuridine, wound healing assay, collagen contraction assay and the expression of COL I and α-smooth muscle actin positive were applied to investigate the cell proliferation, migration and collagen synthesis. Quantitative real-time reverse transcription polymerase chain reaction was applied to determine the cell fibroblastic, tenogenic, and chondrogenic potential.

RESULTS

Bioinformatics analyses found two BMSC-derived exosomal miRNAs, has-miR-144-3p and has-miR-23b-3p, were overlapped in three GSE datasets. PPI network analysis and functional enrichment analyses in the GO and KEGG databases indicated that both miRNAs regulated the PI3K/Akt signaling pathway by targeting phosphatase and tensin homolog (PTEN). In vitro experiments confirmed that miR-144-3p and miR-23b-3p stimulated proliferation, migration and collagen synthesis of NIH3T3 fibroblasts. Interfering with PTEN affected the phosphorylation of Akt and thus activated fibroblasts. Inhibition of PTEN also promoted the fibroblastic, tenogenic, and chondrogenic potential of NIH3T3 fibroblasts.

CONCLUSION

BMSC-derived exosomes promote fibroblast activation possibly through the PTEN and PI3K/Akt signaling pathways, which may serve as potential targets to further promote tendon-bone healing.

[Study on static parameters of internal nasal valve in 3-dimensional model of nasal cavity space]

Objective: To identify the internal nasal valve (INV) and to evaluate its key parameters in the established 3D models of nasal cavity space via Mimics from CT images, in order to provide evidence for quantitative diagnosis of nasal valve compromise. Methods: A total of 32 Han adults without nasal diseases who underwent maxillofacial CT test in Shanghai Ninth People's Hospital from January 2015 to December 2018 were retrospectively recruited, including 16 males and 16 females, with the age ranged from 20 to 80 years (50% age<50 years old). Maxillofacial CT images were used to create 3D model of nasal cavity space. The INV was identified and the following parameters were measured: the angle between the INV and the nasal bone (θ_INV-B), unilateral cross-sectional area of the INV (A_INV-R, A_INV-L), total cross-sectional area of the INV (A_INV), unilateral height of the INV (H_INV-R, H_INV-L), unilateral nasal valve angle (α_INV-R, α_INV-L), and the sum of nasal valve angle (α_INV). The A_INV in our study was compared with the results of the previously adopted planes (Plane_C, perpendicular to the hard palate and Plane_B, plane perpendicular to the nasal bone). The parameters above were compared among genders, age and race groups. SPSS 26 and GraphPad Prism 9 software were used for statistical analysis and mapping of data. Results: The A_INV in our study was (214.87±52.94) mm², which was significantly less than that of Plane_C (254.97±47.80) mm² and Plane_B (226.07±57.36) mm². The measured parameters were as follows: θ_INV-B was (82.07±7.06)°; A_INV-R was (112.66±31.39) mm²; A_INV-L was (102.21±27.14) mm²; A_INV was (214.87±52.94) mm²; H_INV-R was (24.87±4.62) mm; H_INV-L was (24.35±4.86) mm; α_INV-R was (20.48±2.99)°; α_INV-L was (19.65±3.82)°; α_INV was (40.13±6.24)°. The A_INV-R was larger than A_INV-L (t=2.33, P<0.05); The H_INV, A_INV-R, A_INV-L and A_INV of males were more than those of females (t value was 5.77, 3.21, 2.91 and 3.52, respectively, all P<0.01). The A_INV of the young group (<50 years) was larger than that of the old group (t=2.83, P<0.01); The θ_INV-B was different between the Han people and the Caucasian (t=2.92,P<0.01). The α_INV of the Han people was larger than that of Caucasians (Z=-6.92, P<0.01), but the H_INV was smaller (Z=-3.89, P<0.01). Conclusion: The A_INV carried out in 3D models of nasal cavity space is significantly smaller than that obtained by the previous methods of CT evaluation. INV static parameters differ among genders, age and race groups.

Comment on “Outcomes of different minimally invasive surgical treatments for vertebral compression fractures: An observational study”

Recently we read the article entitled “Outcomes of different minimally invasive surgical treatments for vertebral compression fractures: An observational study”. This was an observational study that reviewed the safety and efficacy of different cement augmentation modalities for vertebral compression fractures under osteoporotic condition. Overall, this is a valuable study that can provide a reference for clinical practice. On the other hand, we also noticed some points in the article and are willing to share our views. Further studies with a higher level of evidence can add more knowledge regarding relevant concerns.

Exosomes derived from inflammatory myoblasts promote M1 polarization and break the balance of myoblast proliferation/differentiation

BACKGROUND

Acute muscle injuries are one of the most common injuries in sports. Severely injured muscles are prone to re-injury due to fibrotic scar formation caused by prolonged inflammation. How to regulate inflammation and suppress fibrosis is the focus of promoting muscle healing. Recent studies have found that myoblasts and macrophages play important roles in the inflammatory phase following muscle injury; however, the crosstalk between these two types of cells in the inflammatory environment, particularly the exosome-related mechanisms, had not been well studied.

AIM

To evaluate the effects of exosomes from inflammatory C2C12 myoblasts (IF-C2C12-Exos) on macrophage polarization and myoblast proliferation/differentiation.

METHODS

A model of inflammation was established in vitro by lipopolysaccharide stimulation of myoblasts. C2C12-Exos were isolated and purified from the supernatant of myoblasts by gradient centrifugation. Multiple methods were used to identify the exosomes. Gradient concentrations of IF-C2C12-Exos were added to normal macrophages and myoblasts. PKH67 fluorescence tracing was used to identify the interaction between exosomes and cells. Microscopic morphology, Giemsa stain, and immunofluorescence were carried out for histological analysis. Additionally, ELISA assays, flow cytometry, and western blot were conducted to analyze molecular changes. Moreover, myogenic proliferation was assessed by the BrdU test, scratch assay, and CCK-8 assay.

RESULTS

We found that the PKH-67-marked C2C12-Exos can be endocytosed by both macrophages and myoblasts. IF-C2C12-Exos induced M1 macrophage polarization and suppressed the M2 phenotype in vitro. In addition, these exosomes also stimulated the inflammatory reactions of macrophages. Furthermore, we demonstrated that IF-C2C12-Exos disrupted the balance of myoblast proliferation/differentiation, leading to enhanced proliferation and suppressed fibrogenic/myogenic differentiation.

CONCLUSION

IF-C2C12-Exos can induce M1 polarization, resulting in a sustained and aggravated inflammatory environment that impairs myoblast differentiation, and leads to enhanced myogenic proliferation. These results demonstrate why prolonged inflammation occurs after acute muscle injury and provide a new target for the regulation of muscle regeneration.

[Value of ATP synthase C subunit in predicting cardiac function and outcomes of sepsis]

Objective: To investigate the value of serum mitochondrial ATP synthase C subunit level in the evaluation of cardiac functional status and prognosis in patients with sepsis. Methods: A total of 165 sepsis patients admitted to the Emergency Intensive Care Unit (EICU) of the First Affiliated Hospital of Wenzhou Medical University from January 1, 2017 to December 31, 2018 were included, there were 103 males (62.4%) and 62 females (37.6%) with an age of (63±14) years. Human ATP synthase lipid binding protein (ATP5G1) ELISA kit was used to detect the level of serum ATP synthase C subunit within 24 h after admission to EICU, and compared with that in 45 healthy subjects. Clinical data of patients were collected and divided into groups according to different left ventricular ejection fraction (LVEF) and clinical outcomes. The differences in clinical indicators among each group were compared to evaluate the value of serum ATP synthase C subunit level in the evaluation of cardiac functional state and prognosis of patients with sepsis, and the independent risk factors for cardiac functional state and prognosis of patients with sepsis were analyzed. Results: Compared with the control group, the level of serum ATP synthase C subunit in the sepsis group was higher ((116±62) μg/L vs (77±34) μg/L, P<0.001). Compared with normal cardiac function group, the level of serum ATP synthase C subunit in septic cardiac dysfunction group was higher (P<0.001). Compared with the survival group, the level of serum ATP synthase C subunit in the death group was higher (P<0.05). The receiver operating curve (ROC) was drawn to analyze the value of ATP synthase C subunit, creatine kinase isoenzyme (CK-MB), B-type natriuretic peptide (BNP), troponin I (cTnI), left atrial end diastolic diameter, left ventricular end systolic diameter, left ventricular end diastolic volume, left ventricular end systolic volume in evaluating the cardiac function in patients with sepsis, and the area under the curve (AUC) was 0.928, 0.661, 0.837, 0.814, 0.703, 0.831, 0.794 and 0.765, respectively. The cut-off value, sensitivity and specificity of ATP synthase C subunit in it was 139.44 ng/L, 100% and 75.2%, respectively. ROC was drawn to analyze the prognostic value of age, urea nitrogen (BUN), ATP synthase C subunit, APACHEⅡ score and SAPSⅡ score in patients with sepsis, and the AUC was 0.719, 0.772, 0.656, 0.868 and 0.884, respectively. The cut-off value, sensitivity and specificity of ATP synthase C subunit in it was 131.24 ng/L, 61.9% and 68.7%, respectively. Logistic regression analysis showed that age, BUN, ATP synthase C subunit, cardiac dysfunction, APACHEⅡ score and SAPS Ⅱ score were independent risk factors for the prognosis of patients with sepsis. Conclusion: The level of serum ATP synthase C subunit is closely related to cardiac dysfunction in patients with sepsis, and can effectively predict the prognosis of patients with sepsis.

Effects of subacute ruminal acidosis on colon epithelial morphological structure, permeability, and expression of key tight junction proteins in dairy goats

The hindgut epithelial barrier plays an important role in maintaining absorption and immune homeostasis in ruminants. However, little information is available on changes in colon epithelial barrier structure and function following grain-induced subacute ruminal acidosis (SARA). The objective of this study was to investigate the effects of grain-induced SARA on colon epithelial morphological structure, permeability, and gene expression involved in epithelial barrier function. Twelve mid-lactating (136 ± 2 d in milk; milk yield = 1.68 ± 0.15 kg/d) Saanen dairy goats with 62.13 ± 4.76 kg of body weight were randomly divided into either the control (CON) treatment (n = 6) or SARA treatment (n = 6). The CON goats were fed a basal diet with a nonfiber carbohydrates to neutral detergent fiber ratio of 1.15 for 60 d. The SARA goats were fed 4 diets with increasing nonfiber carbohydrates to neutral detergent fiber ratio at 1.15, 1.49, 2.12, and 2.66 to induce SARA, with each diet (referred to as period) being fed for 15 d, including 12 d for adaptation and 3 d for sampling. Continuous ruminal pH recordings were used to diagnose the severity of SARA. Additionally, colonic tissues were collected to evaluate the epithelial morphological structure, permeability, and expression of tight junction proteins using transmission electron microscopy, Ussing chamber, quantitative real-time PCR, and Western blotting. Profound disruption in the colonic epithelium was mainly manifested as the electron density of tight junctions decreased, intercellular space widened, and mitochondria swelled in SARA goats. Colon epithelial short-circuit current, tissue conductance, and the mucosal-to-serosal flux of fluorescein isothiocyanate-dextran 4 kDa were increased and potential difference was decreased in SARA goats compared with CON goats. Subacute ruminal acidosis increased mRNA and protein expression levels of CLDN1 and OCLN in the colonic epithelium. Overall, the data of the present study demonstrate that SARA can impair the barrier function of the colonic epithelium at both structural and functional levels, which is associated with severe epithelial structural damage and increased permeability and changes in the expression of tight junction proteins.

[A preliminary study on establishment of the Core Occupational Stress Scale (COSS) norms for manufacturing and medical workers in China]

Objective: To establish the Core Occupational Stress Scale (COSS) norm values for manufacturing and medical workers. Methods: A total of 10 316 manufacturing workers of 20 companies from 7 provincial capital cities and 5 031 medical workers of 19 hospitals from 4 provincial capital cities were investigated using a stratified sampling method. Questionnaire information including occupational stress was collected. Norms of mean, percentile and T scores were calculated for COSS total and sub-dimension scores by different demographic characteristics. Based on the normal distribution, cut points of x¯+0.5s, x¯+s, x¯+1.5s of COSS total scores were calculated to classify the degree of occupational stress. Results: The COSS total scores were (45.48±8.16) and (45.71±8.46). The 50th percentiles were both 46, and T score ranges were (15-92) and (16-91), respectively, for manufacturing and medical workers. When the total score was<50, 50-53, 54-57, and >57 for manufacturing worker, or<50, 50-54, 55-58, and >58 for medical workers, occupational stress would be classified into none, mild, moderate, and severe levels. Conclusion: Compatible with the national condition of China, as well as the principles of psychological measurement, these norm values for manufacturing and medical workers could provide theoretical support and practical guideline on occupational mental health promotion.

[Development of the Core Occupational Stress Scale for occupational populations in China]

Objective: To develop the Core Occupational Stress Scale (COSS) for key occupational populations, and to assess the reliability and validity of COSS in China. Methods: According to the literature review, in-depth interview and expert evaluation, the item pool of COSS was established. A total of 20 981 employees (3 703 employees from 2018 and 17 178 employees from 2019) of manufacturing, medical, and traffic polices, etc. from Beijing, Tianjin, Shanghai, Chongqing, Jiangsu, Shandong, Zhejiang, Hunan, Guangdong and Hubei were investigated using convenient sampling of those participating in general or occupational health examination of the day. Item differential test and exploratory factor analysis (EFA) were used to screen items from the item pool; confirmatory factor analysis (CFA) was used to test structure validity; criterion and convergent validity were tested by Pearson correlation. Cronbach's α coefficient was used to test the reliability of the scale. Results: The EFA suggested a four-factor structure for a 17-item version of COSS, which were social support, organization and reward, demand and effort, and control. It explained 62.06% of the total variance and factor loadings ranged from 0.447 to 0.918. The CFA confirmed the hypothesized four-factor model (GFI=0.904, CFI=0.912, RMSEA=0.079). The COSS scores were positively correlated with burnout, depressive symptoms, and effort-reward imbalance scores with r ranging from 0.357 to 0.567 (P<0.05). The total COSS and each dimension of Cronbach's α coefficients were 0.772-0.896. Conclusions: The COSS has good reliability and validity and can be used as an occupation stress assessment for occupational populations in China.

[The mediating role of psychological capital between occupational stress and suicidal ideation]

Objective: To analyze the mediating effect of psychological capital (PsyCap) between occupational stress and suicidal ideation. Methods: In September 2017, stratified-cluster sampling method was adopted to select employees of an electronic manufacturing service industry as respondents for a questionnaire survey in Jiangsu province. The demographic characteristics of employees were collected. A total of 2 465 employees were investigated, and 2 216 valid questionnaires were collected. The level of occupational stress and PsyCap was assessed by the Effort-Reward Imbalance Scale(ERI)and PsyCap Questionnaire. Results: The age of 2 216 employees was (28.70±5.26) years old, including 1 230 males (55.5%). The scores of occupational stress on effort, reward and over-commitment were (3.08±0.63), (3.73±0.60) and (2.51±0.68), respectively. The average ERI index (ratio of effort to return) was (0.88±0.39). The total score of PsyCap was (86.62±15.23). The detection rate of suicidal ideation within two weeks was 13.9% (309/2 216). The average score of effort and over-commitment and the ERI index were positively correlated with the number of suicidal ideation detected within two weeks, with correlation coefficients about 0.081, 0.141 and 0.164, respectively. The average score of reward and total score of PsyCap were negatively correlated with the number of suicidal ideation detected within two weeks, with correlation coefficients about -0.206 and -0.228, respectively. The mediating effect results showed that PsyCap had mediating effect on the effort, reward, over-commitment and suicidal ideation of occupational stress respectively, with mediating effect values of -0.087 (95%CI: -0.018,-0.019), -0.299 (95%CI: -0.428,-0.200) and 0.096 (95%CI: 0.0394, -0.170). The mediating effect percentages were 9.43%, 17.92%, and 9.54%, respectively. Conclusion: PsyCap has a mediating effect between effort, reward, over-commitment of occupational stress and suicidal ideation.

[Lymphocyte activation gene 3 expression on T lymphocyte cell subsets in patients with myelodysplastic syndrome]

Objective: To investigate the expression of Lymphocyte activation gene 3 (LAG3) in myelodysplastic syndromes (MDS) patients. Methods: A total of 16 MDS patients newly diagnosed in Hematology Department of Tianjin Medical University were enrolled from January to November 2019. The healthy control (HC) group includes 16 cases of healthy adults. The expression levels of LAG3 on CD8(+)T cells, CD4(+)T cells and regulatory T cells (Treg) in MDS patients and healthy controls were detected by flow cytometry. Results: A total of 16 patients with MDS were included, including 5 males and 11 females, with a median age of 56 (18-80) years old. HC group includes 16 healthy adults, 8 men and 8 women, with a median age of 40 (17-69) years. There was no statistically significant difference in gender and age composition between the two groups (both P>0.05). The expression of LAG3 on CD8(+)T cells in MDS patients (74.45%±22.31%) was significantly higher than that in HC group (58.78%±14.82%, P<0.05). The LAG3 expression on Treg in MDS patients (64.91%±10.32%) were significantly higher than that of HC group (49.09%±13.58%, P<0.05). There was no statistical difference in LAG3 expression on CD4(+)T cells between the two groups. Conclusion: The expression of LAG3 on CD8(+)T cells and Treg increases in MDS patients than that of healthy people.

[An investigation on professional performance of optometric refraction in spectacles stores in Anyang city of Henan Province]

Objective: To investigate the methods of optometric refraction adopted for adolescents in spectacles stores in Anyang city of Henan Province and the professional performance of optometric refraction. Methods: Cross-sectional study. Maps and yellow pages were used to collect the information of 131 spectacles stores in Anyang city. A questionnaire was used to investigate spectacles stores that had optometry equipment and can provide refraction prescription and spectacles in this city. The questionnaire covered (1) the process of optometric refraction, including whether cycloplegic refraction was conducted for adolescents and children if it was their first-time optometry and the type of cycloplegics,and (2) the opticians' knowledge on optometric refraction for adolescents and children, such as necessity of cycloplegic refraction for adolescents and children and age cut-offs. According to whether they used a comprehensive refractometer, the optometry methods were divided into conventional optometry and medical optometry. Results: Of 131 spectacles stores in Anyang city, 127 were enrolled. A total of 127 questionnaires were distributed and returned with an effective rate of 100%. Conventional optometric refraction was performed in 53 stores (41.73%), and medical optometric refraction was performed in 74 stores (58.27%). Cycloplegic refraction was conducted in only 4 spectacles stores (3.15%) for adolescents and children upon their first-time optometry. The fogging method of refraction was adopted in 31 stores (24.41%), while optometric refraction was directly conducted in 92 stores (72.44%) without controlling accommodation. As for the use of cycloplegia at initial optometric refraction of children, cycloplegia was objected to in 4 stores,and thought to be no need in 28 stores including 6 stores in which the fogging method was used to replace cycloplegia. In 68 stores, cycloplegia was performed if wanted, or children could go to a hospital for it. In 12 stores, the use of cycloplegics was determined by children's vision and diopters. In 5 stores, children were suggested to go to a hospital for cycloplegic refraction. Cycloplegic refraction was required in only 4 stores. As to the age cut-offs of cycloplegic refraction, 6 years old, 12 years old, and 18 years old were considered as the boundary in 7 stores, 33 stores, and 9 stores, respectively.In 11 stores, age was only considered for amblyopia and hyperopia, and in 67 stores, it was not realized. Conclusions: Cycloplegic refraction was found to be conducted for adolescents and children in only 3% of the spectacles stores in Anyang city. Moreover, most of the spectacles store opticians did not support to use cycloplegia before optometric refraction for adolescents and children and lacked knowledge on the age cut-offs of cycloplegic refraction.Standardized training of cycloplegic refraction should be further strengthened. (Chin J Ophthalmol, 2019, 55: 576-581).

Relationship between hospital or surgeon volume and outcomes in joint arthroplasty: protocol for a suite of systematic reviews and dose-response meta-analyses

INTRODUCTION

Joint arthroplasty is a particularly complex orthopaedic surgical procedure performed on joints, including the hip, knee, shoulder, ankle, elbow, wrist and even digit joints. Increasing evidence from volume-outcomes research supports the finding that patients undergoing joint arthroplasty in high-volume hospitals or by high-volume surgeons achieve better outcomes, and minimum case load requirements have been established in some areas. However, the relationships between hospital/surgeon volume and outcomes in patients undergoing arthroplasty are not fully understood. Furthermore, whether elective arthroplasty should be restricted to high-volume hospitals or surgeons remains in dispute, and little is known regarding where the thresholds should be set for different types of joint arthroplasties.

METHODS AND ANALYSES

This is a protocol for a suite of systematic reviews and dose-response meta-analyses, which will be amended and updated in conjunction with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. Electronic databases, including PubMed and Embase, will be searched for observational studies examining the relationship between the hospital or surgeon volume and clinical outcomes in adult patients undergoing primary or revision of joint arthroplasty. We will use records management software for study selection and a predefined standardised file for data extraction and management. Quality will be assessed using the Newcastle-Ottawa Scale, and the meta-analysis, subgroup analysis and sensitivity analysis will be performed using Stata statistical software. Once the volume-outcome relationships are established, we will examine the potential non-linear relationships between hospital/surgeon volume and outcomes and detect whether thresholds or turning points exist.

ETHICS AND DISSEMINATION

Ethical approval is not required, because these studies are based on aggregated published data. The results of this suite of systematic reviews and meta-analyses will be submitted to peer-reviewed journals for publication.

PROSPERO REGISTRATION NUMBER

CRD42017056639.

The change of volatile compounds of two kinds of vinasse-cured ducks during processing

Vinasse-cured duck was processed by boiling, salting, and vinasse-dry-curing or vinasse-wet-curing. Volatile compounds, moisture contents, reducing sugars, and thiobarbituric acid reactive substances (TBARS) values during processing were determined. Reducing sugars decreased during boiling and increased after vinasse-curing. TBARS values increased throughout the processing. The volatiles of ducks during processing and vinasse-curing agents (dry vinasse and vinasse sauce) were 125 compounds. The first principal component (PC1) belonged to the flavor of cooked duck, whereas the second principal component (PC2) represented the flavor of yellow rice wine. The 66.49 and 29.61% of typical aroma of vinasse-dry-cured product were from dry vinasse and lipid oxidation, respectively, whereas the 75.58 and 21.89% of aroma of vinasse-wet-cured product were from vinasse sauce and lipid oxidation, respectively. Lipid oxidation products increased after boiling, whereas salting promoted their release. Compared with vinasse-wet-cured duck, vinasse-dry-cured product presented richer aroma of lipid oxidation and weaker flavor of vinasse-curing agents. Besides, protein denaturation which was caused by ethanol could influence the retention and release of flavor. In conclusion, two kinds of vinasse-curing methods influenced the characteristic volatiles of products and their generation during processing.

In situ preservation of the inferior parathyroid gland during central neck dissection for papillary thyroid carcinoma

BACKGROUND

Postoperative hypocalcaemia due to dysfunction of the parathyroid glands is the most common complication after total thyroidectomy plus central neck dissection (CND). There is a lack of surgical techniques described to help preserve the inferior parathyroid gland in situ during CND. The objective of this study was to introduce the 'TBP layer' (layer of thymus-blood vessel-inferior parathyroid gland) concept for preserving the inferior parathyroid gland in situ during CND, and to evaluate its effectiveness.

METHODS

The study group included patients with primary papillary thyroid cancer who underwent total thyroidectomy with CND using the new surgical concept between January and December 2014. The control group included sex- and age-matched patients who underwent conventional total thyroidectomy with CND between January 2012 and December 2013. The proportion of inferior parathyroid glands preserved in situ and postoperative hypoparathyroidism rates in the two groups were compared.

RESULTS

There were 181 patients in the study group and 306 in the control group. There were no significant differences between the groups in tumour size, multifocality, extrathyroidal extension, and number of harvested and metastatic central lymph nodes. The rate of inferior parathyroid gland preservation in situ was significantly improved from 37·9 to 76·3 per cent on the left side (P < 0·001), and from 52·0 to 77·9 per cent on the right side (P < 0·001), in the study group compared with the control group. The incidence of transient hypoparathyroidism decreased significantly from 35·0 to 7·2 per cent (P < 0·001).

CONCLUSION

Applying the proposed surgical concept improved the rate of inferior parathyroid gland preservation in situ and decreased the incidence of transient postoperative hypoparathyroidism.

[Effects of Wnt3a on osteogenic differentiation of dental pulp stem cells]

Objective: To investigate the effect of Wnt3a on osteogenic differentiation of human dental pulp stem cells (DPSC). Methods: DPSCs were subjected to different concentrations of Wnt3a (0, 5, 20, 50 and 100 μg/L) and at seven days after culture the alkaline phosphatase (ALP) activity was tested. Mineralized nodule formation was examined by alizarin red staining. Osteogenic-related gene expression of bone sialoprotein (BSP), osteocalcin (OCN), collagen type Ⅰ (COL-Ⅰ), Runt-related transcription factor-2 (RUNX2) was examined by quantitative real-time PCR (qPCR). Results: After seven days of induction by DPSC, Wnt3a protein could inhibit the ALP activity (concentration 0: 1.076±0.203, 5 μg/L: 0.828±0.118, 20 μg/L: 0.505±0.044, 50 μg/L: 0.499±0.038, 100 μg/L: 0.483±0.060). The expression of OCN in 5 μg/L Wnt3a group (0.092±0.005) was lower than that in culture medium (0.858±0.190)(P<0.05). Alizarin red staining showed that 5 μg/L Wnt3a had no mineralization induction effect on DPSC. Conclusions: Wnt3a could inhibit osteogenic differentiation of dental pulp stem cells.

[Efficacy for artery chemoembolization combined with radiofrequency ablation in the treatment of advanced non-small cell lung cancer]

OBJECTIVE

To investigate efficacy and safety of artery chemoembolization combined with radiofrequency ablation for advanced non-small cell lung cancer.

METHODS

A total of 138 cases of Sichuan Cancer Hospital of patients with advanced non-small cell lung cancer were retrospectively analyzed from January 2011 to November 2014.All cases were divided into three groups, 61 cases were treated by artery chemoembolization (ACB group), 43 cases were treated by artery chemoembolization combined with radiofrequency ablation (Joint group), 34 cases were treated by radiofrequency ablation (RFA group). Recent efficiency, overall survival time, adverse reactions and complications of three groups were analyzed. The risk factors related to survival time of 138 patients were analyzed.

RESULTS

The recent efficiency of ACB group, Joint group and RFA group were 73.8%(45/61), 93.0%(40/43), 85.3%(29/34), respectively, and the difference was statistically significant (χ(2)=18.499, P=0.005). 1, 2, 3-year survival rates of Joint group were 90.7%(39/43), 58.1%(25/43), 20.9%(9/43), respectively that were better than ACB group(57.4%(35/61), 24.6%(15/61), 11.5%(7/61)) and RFA group(58.8%(20/34), 32.4%(11/34), 11.8%(4/34)), (χ(2) value were respectively 8.242 and 4.934, P values were 0.004 and 0.026). Chemotherapy side effects and complications of ablation were of no significant difference (P>0.05). Chemotherapy side effects and complications of ablation were of no significant difference (P>0.05). The number of tumors, tumor size, TNM staging, eastern cooperative oncology group (ECOG) score were independent risk factors which impact on survival time for non-small cell lung cancer. The artery chemoembolization combined with radiofrequency ablation treatment can improve survival time of patients with advanced non-small cell lung cancer.

CONCLUSION

Artery chemoembolization combined with radiofrequency ablation is a safe, effective, minimally-invasive treatment for advanced non-small cell lung cancer.

Carrier-Multiplication-Induced Structural Change during Ultrafast Carrier Relaxation and Nonthermal Phase Transition in Semiconductors

While being extensively studied as an important physical process to alter exciton population in nanostructures at the fs time scale, carrier multiplication has not been considered seriously as a major mechanism for phase transition. Real-time time-dependent density functional theory study of Ge_{2}Sb_{2}Te_{5} reveals that carrier multiplication can induce an ultrafast phase transition in the solid state despite that the lattice remains cold. The results also unify the experimental findings in other semiconductors for which the explanation remains to be the 30-year old phenomenological plasma annealing model.

Nickel oxide nanoparticles induced pulmonary fibrosis via TGF-β1 activation in rats

Nano nickel oxide (NiO), widely used in industry, has recently been discovered to have pulmonary toxicity. However, no subchronic exposure studies about nano NiO-induced pulmonary fibrosis have been reported. The objective of this study was to investigate pulmonary fibrosis induced by nano NiO and its potential mechanism in rats. Male Wistar rats ( n = 40, 200–240 g) were randomized into control group, nano NiO groups (0.015, 0.06, and 0.24 mg/kg), and micro NiO group (0.024 mg/kg). All rats were killed to collect lung tissue after intratracheal instillation of NiO particles twice a week for 6 weeks. To identify pulmonary fibrosis, Masson trichrome staining, hydroxyproline content, and collagen protein expression were performed. The results showed widespread lung fibrotic injury in histological examination and increased content of hydroxyproline, collagen types I and III in rat lung tissue exposed to nano NiO. To explore the potential pulmonary fibrosis mechanism, transforming growth factor beta 1 (TGF- β1) content was measured by enzyme-linked immunosorbent assay, and the messenger RNA expression of key indicators was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The TGF- β1 content was increased in nano NiO exposure groups, as well as the upregulated gene expression of TGF- β1, Smad2, Smad4, matrix metalloproteinase, and tissue inhibitor of metalloproteinase. The findings indicated that nano NiO could induce pulmonary fibrosis, which may be related to TGF- β1 activation.

[Accuracy and reliability of three-dimensional craniofacial cone-beam CT superimposition method based on voxel registration]

OBJECTIVE

To set up a three-dimensional(3D)craniofacial cone-beam CT(CBCT)superimposition method based on voxel registration, and evaluate the accuracy and reliability of different reference superimposition areas.

METHODS

CBCT scans were taken on a dry skull for three times with a time-interval of two weeks, and CBCT scans were taken on ten adult volunteers twice with a time-interval of one month. The 3D superimposition based on voxel registration was set up by means of Analyze 12.0. The bilateral-zygomatic bone and anterior cranial base were selected as different reference areas for voxel overlapping. The 3D overlapping images were output into Geomagic Qualify 2013, and the surface distances on different craniofacial regions were measured. Three operators repeated three times of these superimposition and measurement. SPSS 19.0 were used to analyze the accuracy and reliability.

RESULTS

When bilateral-zygomatic bone used as superimposition reference, the mean surface distance range of dry skull were from 0.035 to 0.064 mm, and volunteers from 0.099 to 0.182 mm. When the anterior cranial base used as superimposition reference, the mean surface distance range of dry skull were from 0.038 to 0.071 mm, and volunteers from 0.127 to 0.218 mm. All these mean values were less than the CBCT voxel size 0.25 mm(P<0.05), and got sub-pixel precision. No significant difference was found between the different operators at different times(P>0.05).

CONCLUSIONS

This study showed the high accuracy and reliability of 3D CBCT superimposition based on voxel registration, either the anterior cranial base or the bilateral-zygomatic bone as reference. This method could be used for evaluating 3D craniofacial treatment effects.

[Diagnosis and treatment of ocular hypertension]

Ocular hypertension is popular among people, with a prevalence of 3% to 10% in those older than 40 years old. Without proper intervention, over 10% of the patients with ocular hypertension would develop glaucoma in the following 5 to 10 years. Glaucoma has become one of the leading causes of blindness all over the world, which makes it essential for us to pay enough attention to the prevention and treatment of ocular hypertension. However, it is not cost-effective to treat all the patients with ocular hypertension. Certain side effects may also be caused with long-term medical treatment. Therefore, it is of great importance for ophthalmologists to identify the right time and use appropriate therapeutic methods. To introduce the knowledge of ocular hypertension, the definition, epidemiology, diagnosis, risk factors and treatment of ocular hypertension are reviewed in this article. (Chin J Ophthalmol, 2016, 52: 542-546).

Role of interleukin-6 polymorphisms in the development of allergic rhinitis

The aim of this study was to investigate the role played by the IL-6 rs1800795 (-174G/C) and rs1800796 (-572G>C) polymorphisms in the susceptibility to allergic rhinitis in a Chinese population. A total of 265 patients with allergic rhinitis and 265 controls from our hospital were enrolled in this study. The IL-6 rs1800795 and rs1800796 polymorphisms were genotyped by polymerase chain reaction coupled with restriction fragment length polymorphism. The results of the χ(2) statistical analysis revealed significant differences in the allele frequencies of IL-6 rs1800795 between patients with allergic rhinitis and controls (χ(2) = 4.52, P = 0.03). Multivariate logistic regression analyses revealed that individuals with the C allele of IL-6 rs1800795 were susceptible to increased risk of allergic rhinitis, compared to those expressing the G allele (adjusted OR = 1.31; 95%CI = 1.01-1.68). In conclusion, the results of our study indicated that the IL-6 rs1800795 polymorphism was associated with an increased risk of allergic rhinitis.

Phytoremediation of soils contaminated with phenanthrene and cadmium by growing willow (Salix × aureo-pendula CL 'j1011')

To assess the phytoremediation potential of an autochthonous willow (Salix × aureo-pendula CL 'J1011') for phenanthrene (PHE)-contaminated soils and PHE-cadmium (PHE-Cd) co-contaminated soils, we conducted field experiments in the lower reaches of the Yangtze River, China. Ethylenediaminetetraacetic acid (EDTA) and ethyl lactate were tested for individual and combined effects on the phytoremediation efficiency. For PHE-contaminated soils, willow plus ethyl lactate resulted in significant removal of PHE from soils after 45 days, and the PHE concentration in the shoots was significantly higher with than without ethyl lactate. For PHE-Cd co-contaminated soils, both willow plus EDTA and willow plus EDTA and ethyl lactate led to a significant decrease in the concentrations of PHE and Cd in the soils after 45 days, whereas willow alone did not. The PHE and Cd concentrations in the willow shoots were significantly enhanced in the presence of EDTA alone and with ethyl lactate, except for the PHE concentration in stems with EDTA alone. Under the same treatment, the presence of Cd had no significant influence on the PHE removal from soils. The results indicate the feasibility of using this willow together with both EDTA and ethyl lactate for the simultaneous removal of PHE and Cd from soils.

Rumex acetosa L. induces vasorelaxation in rat aorta via activation of PI3-kinase/Akt- AND Ca(2+)-eNOS-NO signaling in endothelial cells

Rumex acetosa L. (RA) (Polygonaceae) is an important traditional Chinese medicine (TCM) commonly used in clinic for a long history in China and the aerial parts of RA has a wide variety of pharmacological actions such as diuretic, anti-hypertensive, anti-oxidative, and anti-cancer effects. However, the mechanisms involved are to be defined. The purpose of the present study was to evaluate the vasorelaxant effect and define the mechanism of action of the ethanol extract of Rumex acetosa L. (ERA) in rat aorta. ERA was examined for its vascular relaxant effect in isolated phenylephrine-precontracted rat thoracic aorta and its acute effects on arterial blood pressure. In addition, the roles of the nitric oxide synthase (NOS)-nitric oxide (NO) signaling in the ERA-induced effects were tested in human umbilical vein endothelial cells (HUVECs). The phosphorylation levels of Akt and eNOS were assessed by Western blot analysis in the cultured HUVECs. ERA induced endothelium-dependent vasorelaxation. The ERA-induced vasorelaxation was abolished by L-NAME (an NOS inhibitor) or ODQ (a sGC inhibitor), but not by indomethacin. Inhibition of PI3-kinase/Akt signaling pathway markedly reduced the ERA-induced vasorelaxation. In HUVECs, ERA increased NO formation in a dose-dependent manner, which was inhibited by L-NAME and by removing extracellular Ca(2+). In addition, ERA promoted phosphorylation of Akt and eNOS, which was prevented by wortmannin and LY294002, indicating that ERA induces eNOS phosphorylation through the PI3-kinase/Akt pathway. Further, in anesthetized rats, intravenously administered ERA decreased arterial blood pressure in a dose-dependent manner through an activation of the NOS-NO system. In summary, the ERA- induced vasorelaxation was dependent on endothelial integrity and NO production, and was mediated by activation of both the endothelial PI3-kinase/Akt- and Ca(2+)-eNOS-NO signaling and muscular NO-sGC-cGMP signaling.

Theory of oxygen-boron vacancy defect in cubic boron nitride: a diamond NV⁻ isoelectronic center

A color center in c-BN which is isoelectronic to diamond NV⁻ is predicted based on first-principles electronic structure calculations using the Heyd-Scuseria-Ernzerhof hybrid functional. The defect consists of a substitutional oxygen and an adjacent boron vacancy (O(N)-V(B)). We find that the O(N)-V(B) center is optically accessible with a zero-phonon line of about 1.6 eV. The O(N)-V(B) center also shares much of the characteristics of the GC-2 center often observed in c-BN. A prominent vibronic coupling peak is predicted to be around 55 meV, which is in excellent agreement with the characteristic phonon frequency (56 meV) observed in the luminescence spectra of the GC-2 center.

Carbon kagome lattice and orbital-frustration-induced metal-insulator transition for optoelectronics

A three-dimensional elemental carbon kagome lattice, made of only fourfold-coordinated carbon atoms, is proposed based on first-principles calculations. Despite the existence of 60° bond angles in the triangle rings, widely perceived to be energetically unfavorable, the carbon kagome lattice is found to display exceptional stability comparable to that of C(60). The system allows us to study the effects of triangular frustration on the electronic properties of realistic solids, and it demonstrates a metal-insulator transition from that of graphene to a direct gap semiconductor in the visible blue region. By minimizing s-p orbital hybridization, which is an intrinsic property of carbon, not only the band edge states become nearly purely frustrated p states, but also the band structure is qualitatively different from any known bulk elemental semiconductors. For example, the optical properties are similar to those of direct-gap semiconductors GaN and ZnO, whereas the effective masses are comparable to or smaller than those of Si.

Cardiovascular effects of ethanol extract of Rubus chingii Hu (Rosaceae) in rats: an in vivo and in vitro approach

Rubus chingii Hu (Rosaceae) is an important traditional Chinese medicine that has been used to improve function of the kidney and treat excessive polyuria. However, the effects of Rubus chingii on the cardiovascular system and its pharmacological mechanisms of action have not been studied. The aim of the present study was to evaluate the cardiovascular effects of ethanol extract of Rubus chingii (ERC) in rats. The changes in systolic blood pressure and heart rate of rats and vascular tone of aortic rings in in vitro were measured using pressure transducer and force transducer, respectively, connected to a multichannel recording system. ERC decreased systolic blood pressure and heart rate in a concentration-dependent manner. ERC induced vasorelaxation in a concentration-dependent manner. The ERC-induced vasorelaxation was not observed in the absence of the endothelium. The vasorelaxant effect of ERC was significantly attenuated by inhibition of endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC), or Ca(2+) entry from extracellular sources with L-NAME, ODQ, diltiazem, or extracellular Ca(2+) depletion, respectively. Similarly, an inhibition of Akt with wortmannin attenuated the ERC-induced vasorelaxation. Modulators of the store-operated Ca(2+) entry, thapsigargin, Gd(3+), and 2-aminoethyl diphenylborinate markedly attenuated the ERC-induced vasorelaxation. Furthermore, 4-aminopyridine an inhibitor of voltage-dependent K(+) (KV) channel, significantly attenuated the ERC-induced vasorelaxation. However, tetraethylammonium and glibenclamide, had no significant effect on the ERC-induced vasorelaxation. Indomethacin, atropine, and propranolol had no effects on the ERC-induced vasorelaxation. The present study demonstrates that ERC induces vasorelaxation via endothelium-dependent two-step signaling: an activation of the Ca(2+)-eNOS-NO signaling in the endothelial cells and then subsequent stimulation of the NO-sGC-cGMP-KV channel signaling in the vascular smooth muscle cells. The Akt-eNOS pathway is also suggested to be involved in this relaxation. Also, the findings suggest that the ERC-induced vasorelaxation is closely related to the hypotensive action of the agent.

Antialcoholic liver activity of whey fermented by Lactobacillus casei isolated from koumiss

Whey fermented liquid (WFL) was studied for its hepatoprotective effects by using chronic alcohol-induced mice. Whey fermented liquid, prepared by inoculating whey with 4% (vol/vol) Lactobacillus casei and then incubating at 41°C for 8h, was used to orally treat alcohol-induced mice at 3 dosages for 5 wk. Ethanol consumption significantly reduced the activity of superoxide dismutase and glutathione peroxidase, while lowering glutathione content and increasing levels of aspartate aminotransferase, alanine aminotransferase, total triglyceride, malondialdehyde, and cytochrome P450 2E1. Treatment with WFL significantly attenuated the increased levels of alanine aminotransferase, aspartate aminotransferase, triglyceride, and cytochrome P450 2E1, while decreasing superoxide dismutase, glutathione peroxidase, malondialdehyde, and glutathione levels. Pathological changes in the livers of mice who had ingested alcohol were improved by the administration of WFL. These results suggest that WFL may exert a protective effect against alcoholic liver disease by increasing antioxidant activity, which supports the use of WFL as an antialcoholic liver disease treatment.

Outcomes of laryngectomy in elderly patients with laryngeal carcinoma

Laryngeal carcinoma is a common tumor of the head and neck region. This study aimed to examine the outcomes of laryngectomy in elderly patients with laryngeal carcinoma. One-hundred twenty-two patients (male, 117; female, 5) aged 60 years or older (range, 60-94 years) who underwent laryngectomy between 1996 and 2010 were included. All patients were diagnosed with squamous cell carcinoma of the larynx, and 95 patients (77.9%) had additional concurrent diseases. Tumors were staged according to the TNM categories of the American Joint Committee on Cancer 2002 criteria; there were 16 stage-I, 24 stage-II, 52 stage-III, and 30 stage-IV cases. With regard to treatment modalities, 10 patients underwent transoral laser laryngectomy, 25 underwent partial laryngectomy, and 87 underwent total laryngectomy. When necessary, neck dissection was performed according to the Dalian criteria set in 2004 (a Chinese standard). Of the 122 cases, there were 114 cases of grade I (93.4%), 5 cases of grade II, and 3 cases of grade III (pharyngeal fistula in 2 cases recovered after 2 weeks of care) wound healing. No significant differences were observed in the occurrence or severity of comorbidities. The 1-, 3-, and 5-year actuarial survival rates were 97.5% (119/122), 84.4% (92/109), and 68.4% (67/98), respectively. Age alone should not be used to determine treatment options for elderly patients with squamous cell carcinoma. Presuming that careful pre-treatment evaluations are performed, laryngectomy is a key method for elderly patients with laryngeal carcinoma.

Toll-like receptor 3 polymorphism is not associated with neovascular age-related macular degeneration and polypoidal choroidal vasculopathy in the Chinese

Toll-like receptor 3 (TLR3) variants in mainland northern Chinese patients with polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (nAMD) were investigated. The complete genes of TLR3, including all exons and the promoter region, were assessed using direct sequencing technology of 284 unrelated mainland northern Chinese individuals: 96 nAMD patients, 92 PCV patients, and 96 controls. Six single nucleotide polymorphisms were identified: rs5743303, rs5743305, rs5743312, rs3775291, rs3775290, and rs6830345. The distribution of TLR3 genotypes for nAMD and PCV was not significantly different compared with normal controls. This study indicates that the TLR3 gene polymorphism is not associated with nAMD and PCV in northern Chinese patients.

Universal primers for amplification of the complete mitochondrial control region in marine fish species

Through multiple alignment analysis of mitochondrial tRNA-Thr and tRNA-Phe sequences from 161 fishes, new universal primers specially targeting the entire mitochondrial control region were designed. This new primer set successfully amplified the expected PCR products from various kinds of marine fish species, belonging to various families, and the amplified segments were confirmed to be the control region by sequencing. These primers provide a useful tool to study the control region diversity in economically important fish species, the possible mechanism of control region evolution, and the functions of the conserved motifs in the control region.

Fermi-level tuning of epitaxial Sb2Te3 thin films on graphene by regulating intrinsic defects and substrate transfer doping

High-quality Sb2Te3 films are obtained by molecular beam epitaxy on a graphene substrate and investigated by in situ scanning tunneling microscopy and spectroscopy. Intrinsic defects responsible for the natural p-type conductivity of Sb2Te3 are identified to be the Sb vacancies and Sb(Te) antisites in agreement with first-principles calculations. By minimizing defect densities, coupled with a transfer doping by the graphene substrate, the Fermi level of Sb2Te3 thin films can be tuned over the entire range of the bulk band gap. This establishes the necessary condition to explore topological insulator behaviors near the Dirac point.

Association of CYP2C19*3 gene polymorphism with breast cancer in Chinese women

Cytochrome P450 (CYP) 2C19 metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids, which significantly promote proliferation of cancer cells in vitro and in vivo. We looked for a possible association between human CYP2C19*3 gene polymorphism and breast cancer in the Chinese Han population. In a Chinese Han case-control study of breast cancer patients (N = 600) and age- and gender-matched healthy controls (N = 600), we investigated polymorphism in the CYP2C19 gene by PCR-RFLP analysis. The CYP2C19*3 AG + AA genotype was significantly more prevalent in breast cancer patients than in control subjects (6.67 vs 3.00%; P = 0.003). The odds ratio for carriers of AG + AA genotype for breast cancer was 2.31 (95% confidence interval = 1.27-4.43). Among patients, estrogen receptor, tumor size, histologic grade, presence of primary lymphonode metastases, progesterone receptor positivity, and age at diagnosis were not found to be significantly associated with CYP2C19*3 genotypes (all P > 0.05). We conclude that the CYP2C19*3 gene polymorphism is associated with breast cancer risk in Chinese Han women.

Antioxidant micronutrients improve intrinsic and UV-induced apoptosis of human lymphocytes particularly in elderly people

OBJECTIVE

Aging and oxidative stress may lead to enhanced cellular damage and programmed cell death. To study the association of intrinsic apoptosis with age and the effect of antioxidant supplementation on intrinsic and UV-induced apoptosis in children, young and elderly people.

METHODS

The study was a 2 months, double-blind, randomized trial. Three age groups were studied: children, young adults and elderly people. A total of 274 healthy subjects were allocated to a group supplemented with moderate amounts of retinol, β-carotene, α-tocopherol, ascorbic acid and selenium or placebo. Plasma oxidative stress parameters were detected and apoptosis of lymphocytes was evaluated with TUNEL staining.

RESULTS

At baseline, percentages of intrinsic apoptosis were 13.8% and 11.1% in elderly and young people, respectively, both significantly higher than children (6.3%). A decrease of 1.7% and 2.3% in intrinsic apoptosis of lymphocytes was found in the supplemented groups of young and elderly people compared with their control groups (all p values <0.001), but no significant decrease in children. Moreover, percentages UV-induced apoptosis significantly decreased by 1.4%, 1.9% and 3.1% in children, young and elderly people, respectively, compared with control groups after the trial. There were considerable increments in concentrations of plasma β-carotene, retinol, tocopherol, ascorbic acid and selenium in all three treated groups after the supplementation.

CONCLUSIONS

Young and elderly people have a higher intrinsic apoptosis than children, which was improved by antioxidant supplementation. UV-induced damage was attenuated by the supplementation in all three age groups.

Dynamic Jahn-Teller effect in the NV(-) center in diamond

The negatively charged nitrogen-vacancy (NV(-)) center in diamond is considered to be one of the most promising solid state systems for quantum information applications. Excited states of the NV(-) center play a center role in the proposed applications. Using a combination of first-principles calculations and vibronic interaction model analysis, we establish the presence of a dynamic Jahn-Teller effect in the (3)E excited state. The calculated temperature-dependent dephasing rate for the zero phonon line as well as the splitting of the first two vibronic states are in good agreement with experiment.

Hole-mediated hydrogen spillover mechanism in metal-organic frameworks

Hydrogen spillover on carbon-based systems has been proposed as a viable alternative for room-temperature storage. Given the strength of the C-H bonds, however, it is unclear if spillover indeed takes place in such materials. We performed a first-principles study of H spillover on IRMOF-1. Spillover becomes thermodynamically stable only at high H coverage with a calculated Gibbs free energy of -14  kJ/mol at ambient condition. In general, however, spillover may not proceed due to high-energy states at lower H coverage. We propose that hole doping can substantially lower the energies as well as barriers to enable spillover at ambient conditions.