[Association of arsenic with unexplained recurrent spontaneous abortion: a case-control study]

Objective: To explore the association of arsenic with unexplained recurrent spontaneous abortion (URSA). Methods: A case-control study was conducted to select URSA patients who were admitted to the Beijing Maternal and Child Health Care Hospital affiliated to Capital Medical University from April to October 2018 as a case group. Women who had a normal pregnancy in the Family Planning Department of the hospital but volunteered to have an abortion were selected as a control group. The case and control group were paired in a 1: 1 ratio. The inclusion criteria of the case group were patients with newly diagnosed recurrent spontaneous abortion who had clinically confirmed more than 2 spontaneous abortions and had 20 weeks prior to pregnancy, excluding patients with recurrent spontaneous abortion caused by abnormal blood coagulation (anti-phospholipid antibody positive), abnormal physiological anatomy (B-ultrasound), abnormal immune factors (anti-nuclear antibody positive, anti-cardiolipin antibody, etc.), genetic chromosomal abnormalities (karyotype analysis) and pathogenic microbial infection. The control group was matched according to the age of the case group (±3 years old) and the gestational age (±2 weeks) to exclude adverse pregnancy outcomes such as stillbirth, congenital malformation, premature delivery and low birth weight infants. A total of 192 subjects were included. Questionnaires were used to collect information of all subjects, and 12 ml of peripheral venous blood was collected to detect blood arsenic levels. Blood arsenic levels were divided into low concentration group (<1.00 μg/L), medium concentration group (1.00-1.50 μg/L) and high concentration group (>1.50 μg/L). The multivariate conditional logistic regression was performed to analyze the relationship between blood arsenic exposure and URSA and explore the influencing factors of blood Arsenic. Results: The geometric mean values of blood arsenic level in the cases group and control group were 1.68 (1.50-1.86) μg/L and 1.26 (1.17-1.37) μg/L, respectively. The blood arsenic level in the case group was significantly higher than that in the control group (P<0.05). The results of multivariate conditional logistic regression analysis showed that after adjusting for tobacco exposure during pregnancy, pre-pregnancy body mass index and the effects of residential decoration in past five years, the risk of URSA was higher in the high-concentration group compared with the low-concentration group (OR=2.56, 95%CI:1.06-6.24). Conclusion: Blood arsenic may increase the risk of URSA in women of childbearing age.

Optic Nerve Crush Induces Changes of Hydrogen Sulfide Synthases Expression in the Rat Retina

OBJECTIVES

To investigate the expression changes of the hydrogen sulfide synthases cystathionine γ-lyase （CSE）, cystathionine β-synthase （CBS）, and 3-mercaptopyruvate sulfurtransferase （3-MST）, after optic nerve crush （ONC） in rat the retina.

METHODS

The rat model of ONC was established. Rats were divided into normal control, ONC, and sham control groups. Histopathologic changes in retina, the number of retinal ganglion cells （RGC） and retinal thickness of inner part （RTIP） were measured. The changes of CSE, CBS and 3-MST mRNA expression were detected with quantitative real-time PCR.

RESULTS

The retinal histostructure was normal in normal controls and with minor changes in sham controls, respectively. Compared with sham group, significant retina damages were found in the ONC group： a time-dependent reduction of RGC number and RTIP. Expressions of CSE, CBS and 3-MST mRNA in rat retina were detected in normal control. Compared with normal controls, the expressions of CSE, CBS and 3-MST mRNA did not show any significant changes in the sham controls. Compared with sham controls, CBS mRNA expressions showed a time-dependent increase at 3 d, 7 d and 14 d after crush in the ONC group; CSE mRNA expressions increased to the peak at 3 d and then slightly reduced at 14 d after crush; 3-MST mRNA expressions showed the trend of increase at 3 d and 7 d and then enhanced remarkably at 14 d after crush.

CONCLUSIONS

Hydrogen sulfide synthases CSE, CBS and 3-MST expressions were up-regulated in rat retina following ONC, which may cause an increase in local endogenous hydrogen sulfide production in the retina and a compensatory protective effect.

Efficient high-power dual-wavelength lime-green Nd:YVO4 lasers

An efficient high-power dual-wavelength lime-green Nd:YVO₄ self-Raman laser is inventively developed by using two different lithium triborate (LBO) crystals. The first and second LBO crystals are employed to generate the 559 nm lime and 532 nm green lasers, respectively. The temperature of the first LBO crystal is fixed at the optimal phase matching, whereas the temperature of the second LBO crystal is tuned to flexibly control the relative strengths between the 532 and 559 nm waves. When the temperature of the second LBO crystal is set for the maximal total output power, the 532 and 559 nm output powers, respectively, are 7.1 and 2.9 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 31.6%. When the temperature is controlled for the balanced output, the 532 and 559 nm powers, respectively, are 4.3 and 4.2 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 26.9%.

Microstructures and Photodegradation Performance toward Methylene Orange of Sputtering-Assisted Decoration of ZnFe₂O₄ Crystallites onto TiO₂ Nanorods

In this study, TiO₂⁻ZnFe₂O₄ (ZFO) core-shell nanorods with various ZFO crystallite thicknesses were synthesized through sputtering-deposited ZFO thin films onto the surfaces of TiO₂ nanorods. By coupling the ZFO narrow bandgap oxide with TiO₂, an enhanced photodegradation efficiency of methylene orange under irradiation was achieved. Structural analyses revealed that ZFO crystallites fully covered the surfaces of the TiO₂ nanorods. The sputtering-deposited ZFO crystallites on the head region of the composite nanorods were markedly thicker than those covering the lateral region of the composite nanorods. The coverage of ZFO crystallites on the TiO₂ nanorods led to an improved light harvesting, a decrease in the hole⁻electron recombination rate, as well as the enhanced photodegradation activity of the TiO₂⁻ZFO heterostructures under irradiation. The optimized ZFO thickness on the head region of the composite nanorods was approximately 43 nm on average and that at the lateral region of the composite nanorods was 15 nm, which exhibited superior photodegradation ability to methylene orange and retained a stable photodegradation efficiency of approximately 97% after cycling tests. The results herein demonstrate that sputtering deposition of ZFO crystallite with tunable thickness is a promising approach to designing TiO₂⁻ZFO composite nanorods with various ZFO coverage sizes and to adjust their photodegradation ability toward organic dyes.

Efficient high-power continuous-wave lasers at green-lime-yellow wavelengths by using a Nd:YVO4 self-Raman crystal

Efficient high-power continuous-wave Nd:YVO₄ visible lasers at versatile wavelengths of 532 (green), 559 (lime), and 588 nm (yellow) are demonstrated to be achieved by using the identical cavity mirrors and gain medium. A dichroic coating is deposited on one end surface of the gain medium to gather the backward green-yellow emission. The green, lime, and yellow outputs are individually optimized by using different phase-matched lithium triborate (LBO) crystals for second harmonic generation (SHG) of the fundamental field, sum frequency generation (SFG) of the fundamental and the stimulated Raman fields, and SHG of the stimulated Raman field, respectively. At a pump power of 31.6 W, the output powers at 532, 559, and 588 nm can be up to 6.8, 5.4, and 3.1 W. The high efficient and compact Nd:YVO₄ lasers at green-lime-yellow wavelengths can be potentially beneficial to future applications in retinal photocoagulation.

[Cause and control of non-sampling error in China National Human Biomonitoring Program]

The size of the non-sampling error is directly related to the accuracy and reliability of the sampling survey result. This paper studied the non-sampling errors generated during the sampling process of the China National Human Biomonitoring Program(CNBP), mainly including the sampling frame error, non-response error and measurement error. The program reduced the influence of the non-sampling error on the quality of the survey effectively by scientifically designing the sampling scheme and questionnaire, strengthening investigator trainings and standardizing the data review, which could be used to provide reference for the control of non-sampling errors in public health monitoring projects in China.

Role of HMGB1 in Post-traumatic Endoplasmic Reticulum Stress in Rat Lung Tissues

OBJECTIVES

To explore the role of high mobility group B1 （HMGB1） protein in the post-traumatic endoplasmic reticulum stress （ERS） in rat lung tissues.

METHODS

The rat model of acute lung injury was established by crushing the hind limbs of rats with standard weight. The first experiment was to divide rats into postural control group and crush groups （6 h, 18 h and 30 h after crushing）. The second experiment was to divide rats into postural control group, 18 h crush group, HMGB1 inhibitor sodium butyrate （SB） group and 18 h crush+SB group. The protein expression changes of HMGB1 and ERS- related proteins （GRP78, caspase-12, CHOP and IRE1α） in rat lung tissues were detected with Western blotting. Meanwhile, the pathological changes of rat lungs were observed by HE stain.

RESULTS

Compared with the postural control group, the expression levels of ERS-related proteins （GRP78, caspase-12, CHOP and IRE1α） and HMGB1 protein in rat lung tissues by crushing the hind limbs of rats were obviously increased. The protein levels reduced at 30 h after crushing but were still higher than those of postural control group and obvious pathological changes of acute lung injury were observed simultaneously in rats. Compared with the 18 h crush group, the expression levels of the ERS-related proteins and HMGB1 protein in rat lung tissues were attenuated in 18 h crush+SB group, and the pathological changes of rat lung injury began to alleviate.

CONCLUSIONS

HMGB1-ERS pathway activated by traumatic stress can lead to acute lung injury in rats.

[The relationship between IL-4 and trace elements in patients with allergic rhinitis of hui and han populations in Ningxia]

Objective: To examine the relationship between trace elements and IL-4 in patients with allergic rhinitis(AR).Method:According to the inclusion and exclusion criteria, a total of 260 cases in AR group(130 hui cases, 130 han cases),and 260 cases in normal control group(130 hui cases, 130 han cases) were recruited in this study. The concentrations of IL-4 were detected by enzyme linked immunosorbent assay(ELISA), the contents of Zn, Mn, Ni, Se and Fe were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES), and the correlation between the trace elements and IL-4 were also analyzed.Result:IL-4 levels in serum of both hui and han AR patients were higher than those in control group(P <0.05). Contents of serum Zn and Se in hui AR patients were lower than those in control group(P <0.05), Ni content was higher than that in control group(P <0.05);Zn level in serum of han AR cases was lower than that in control group,Ni content was higher than that in control group (P <0.05).The serum IL-4 level in AR group was positively correlated with Ni(P <0.01,r=0.671), and negatively correlated with Zn(P <0.01, r=-0.819).Conclusion:We demonstrated that there are significant correlations between IL-4 and Zn,Ni in the serum of patients with AR in Ningxia hui and han population. It indicates that trace elements are involved in the occurrence and development of AR, and may as a therauptic target of AR.

Flexible modulation of electronic and magnetic properties of zigzag H-MoS2 nanoribbons by crack defects

The effects of crack defects on electronic and magnetic properties of zigzag MoS₂ nanoribbons are investigated systematically by first-principles calculations based on spin-polarized density functional theory. We find that not only the electronic and spin transport ability of zigzag MoS₂ nanoribbons can be enhanced significantly by the armchair crack defects, but also their magnetism could be modulated flexibly by crack defects. Our study suggests that the introduction of crack defect is a feasible way to modulate the electronic and magnetic properties of zigzag MoS₂ nanoribbons. We further propose that the crack defects may also provide a useful tool for improving the performance of devices.

Blunt Traumatic Cardiac Rupture Presenting as Massive Haemothorax

Cardiac rupture following blunt thoracic trauma in motor vehicle crash generally causes death at scene, and is rarely diagnosed preoperatively. However, early emergency thoracotomy in the emergency department (ED) or operating room might reduce the mortality but the benefit is still controversial. A haemodynamically unstable 28-year-old woman following motor vehicle crash was detected to have right haemothorax on chest X-ray. Thoracic computed tomography (CT) revealed additional lung contusions and multiple bone fractures. She developed cardiac arrest during open thoracotomy and had restored spontaneous circulation after open-chest cardiopulmonary resuscitation (CPR). This report highlights that CT scan in haemodynamically unstable patients could delay surgical control of the injury. Open-chest CPR can be life-saving for blunt chest injury developing cardiac arrest. (Hong Kong j.emerg.med. 2015;22:320-323)

[Microdeletion and Mutation of Y Chromosome in Full Sibling Identification]

OBJECTIVES

To explore the identification method of full sibling between two males with microdeletion and mutation of Y chromosome.

METHODS

DNA were extracted from two samples. The type testing of Y-STR and autosomal STR were performed. Full sibling between two individuals was calculated by IBS, ITO and discriminant functions methods.

RESULTS

There were 2 loci mutations existed in 33 Y-STR loci and one of the two samples had 19 loci deletions. The IBS of two samples was 53 and greater than the threshold which was 42; FSI was 1.36×10¹⁶ and far greater than 19. The discriminant function of full sibling-unrelated individual D_FS2 was greater than D_R2, which meant the two individuals tend to be full sibling.

CONCLUSIONS

The methods of IBS, ITO and discriminant functions of full sibling-unrelated individual can be used comprehensively to provide more reliable expert opinion in microdeletion and mutation of Y chromosome in full sibling identification.

MicroRNA-30a Inhibits Colorectal Cancer Metastasis Through Down-Regulation of Type I Insulin-Like Growth Factor Receptor

BACKGROUND

miR-30a expression is down-regulated and regulates tumor suppressors in various cancers.

AIM

We investigated the mechanisms underlying the biological role of miR-30a in CRC.

METHODS

MicroRNA, mRNA, and protein expression were analyzed by quantitative real-time PCR and Western blot. The migration and invasion abilities of CRC were determined by wound healing assay, and trans-well migration and invasion. A luciferase reporter assay was used to confirm the targets of miR-30a.

RESULTS

miR-30a expression was significantly down-regulated in CRC tissues and in CRC tissue with lymph node metastasis compared to CRC tissue without metastasis. Overexpression of miR-30a suppressed migration and invasion through insulin-like growth factor 1 receptor (IGF1R) in CRC cells. miR-30a suppresses IGF1R protein expression and inhibits β-catenin or p-AKT and increases E-cadherin expression. The IGF1R expression level is also up-regulated in CRC tumors and inversely correlated with miR-30a in CRC specimens.

CONCLUSIONS

miR-30a functions as a tumor-suppressive miRNA, which may provide a therapeutic strategy for metastasis of CRC.

[Progress of molecular subtypes of colorectal cancer]

Colorectal cancer is one of the leading causes of morbidity and mortality around the world. Although the staging and classification systems, such as tumor/node/metastasis (TNM) staging, are widely used in clinic, there are some limitations. For example, the patients with the same pathological type, TNM stage and treatment regimen show a completely different prognosis and outcome. In the present, molecular subtyping was concerned for a more precise and accurate staging of colorectal cancer. Herein, we reviewed the literature of the molecular subtypes of colorectal cancer in the past decades. The clinical significance of various molecular subtyping systems was evaluated and compared. It will provide reference for the precision medicine of colorectal cancer in the future.

Passivity-based control framework for task-space bilateral teleoperation with parametric uncertainty over unreliable networks

Bilateral teleoperation systems developed in joint-space or in task-space without taking into account parameter uncertainties and unreliable communication have limited practical applications. In order to ensure stability, improve tracking performance, and enhance applicability, a novel task-space control framework for bilateral teleoperation with kinematic/dynamic uncertainties and time delays/packet losses is studied. In this paper, we have demonstrated that with the proposed control algorithms, the teleoperation system is stable and position tracking is guaranteed when the system is subjected to parametric uncertainties and communication delays. With the transformation of scattering variables, a packet modulation, called Passivity-Based Packet Modulation (PBPM), is proposed to cope with data losses, incurred in transmission of data over unreliable network. Moreover, numerical simulations and experiments are also presented to validate the efficiency of the developed control framework for task-space bilateral teleoperation.

SPECTRAL CORRECTION FACTORS FOR CONVENTIONAL NEUTRON DOSE METERS USED IN HIGH-ENERGY NEUTRON ENVIRONMENTS-IMPROVED AND EXTENDED RESULTS BASED ON A COMPLETE SURVEY OF ALL NEUTRON SPECTRA IN IAEA-TRS-403

This paper presents improved and extended results of our previous study on corrections for conventional neutron dose meters used in environments with high-energy neutrons (En > 10 MeV). Conventional moderated-type neutron dose meters tend to underestimate the dose contribution of high-energy neutrons because of the opposite trends of dose conversion coefficients and detection efficiencies as the neutron energy increases. A practical correction scheme was proposed based on analysis of hundreds of neutron spectra in the IAEA-TRS-403 report. By comparing 252Cf-calibrated dose responses with reference values derived from fluence-to-dose conversion coefficients, this study provides recommendations for neutron field characterization and the corresponding dose correction factors. Further sensitivity studies confirm the appropriateness of the proposed scheme and indicate that (1) the spectral correction factors are nearly independent of the selection of three commonly used calibration sources: 252Cf, 241Am-Be and 239Pu-Be; (2) the derived correction factors for Bonner spheres of various sizes (6"-9") are similar in trend and (3) practical high-energy neutron indexes based on measurements can be established to facilitate the application of these correction factors in workplaces.

[A Study on the establishment of immune thrombocytopenia model induced by anti-platelet GPⅠbα antibodies]

Objective: To establish primary immune thrombocytopenia (ITP) animal model induced by anti-platelet membrane glycoprotein GPⅠbα antibodies AN51 and R300. Methods: Twenty guinea pigs (6-8 week) were divided into 4 groups. Five guinea pigs in each group were intravenously injected with different doses of AN51 (0.05, 0.1, 0.2 μg/g) and 0.2 μg/g IgG as control. The whole blood was collected from inner angular venous plexus. Platelets number was determined by an automated cell counter and Swiss-Jim method. Then, the similar protocol was used to establish ITP nude mice model by intraperitoneal injection of different concentrations of anti-platelet GPⅠbα antibody R300, respectively. Results: ①Five minutes after intravenous injection of AN51 at 0.05, 0.1 and 0.2 μg/g, the platelet counts of guinea pigs reduced about 0-5%, 50%-60% and 70%-80% compared to the control group, respectively. The difference was statistically significant (P<0.01) . ②Six hours after intraperitoneal injection of R300 at 0.05, 0.1, 0.2 μg/g, the platelet counts of nude mice decreased about 20%-30%, 60%-70% and 80%-90% compared to the control group, respectively. The difference was statistically significant (P<0.01) . The nude mice, injected 0.2 μg/g R300 once a day for 2 weeks, showed typical ITP clinical manifestations including large number of petechiaes or ecchymoses on limbs, head and abdomen. Conclusion: AN51 at 0.2 μg/g and R300 at 0.2 μg/g could establish stable ITP model in guinea pigs and nude mice respectively.

First-principles study on structural, thermal, mechanical and dynamic stability of T'-MoS2

Using first-principles density functional theory calculations, we investigate the structure, stability, optical modes and electronic band gap of a distorted tetragonal MoS₂ monolayer (T'-MoS₂). Our simulated scanning tunnel microscopy (STM) images of T'-MoS₂ are dramatically similar to those STM images which were identified as K _x (H₂O) _y MoS₂ from a previous experimental study. This similarity suggests that T'-MoS₂ might have already been experimentally observed, but due to being unexpected was misidentified. Furthermore, we verify the stability of T'-MoS₂ from the thermal, mechanical and dynamic aspects, by ab initio molecular dynamics simulation, elastic constants evaluation and phonon band structure calculation based on density functional perturbation theory, respectively. In addition, we calculate the eigenfrequencies and eigenvectors of the optical modes of T'-MoS₂ at [Formula: see text] point and distinguish their Raman and infrared activity by pointing out their irreducible representations using group theory. At the same time, we compare the Raman modes of T'-MoS₂ with those of H-MoS₂ and T-MoS₂. Our results provide useful guidance for further experimental identification and characterization of T'-MoS₂.

High levels of glucose promote the activation of hepatic stellate cells via the p38-mitogen-activated protein kinase signal pathway

The relationship between the p38-mitogen-activated protein kinase (p38-MAPK) signal pathway and high glucose-induced hepatic stellate cell (HSC) activation was investigated in this study. Sixty human HSC samples were randomly selected and used in the control (cultured normally), high-glucose (cultured in the presence of high glucose), and blocking (cultured under high-glucose conditions in the presence of the p38-MAPK inhibitor, SB203580) groups. The cells were incubated for 120 h and subsequently analyzed for morphological changes by inverted microscopy and for a-smooth muscle actin (a-SMA) expression (to determine the degree of HSC activation) by the method of streptavidin-biotin complex and western blot. Phospho-p38-MAPK protein expression was analyzed by western blotting. a-SMA and phospho-p38-MAPK expression was significantly upregulated in HSCs cultured under high-glucose conditions, compared to the HSCs cultured normally (P < 0.01). On the other hand, phospho-p38-MAPK and a-SMA protein levels were significantly lower in the blocking group compared to the high-glucose group (P < 0.01). Based on these results, we concluded that high-glucose levels induce HSC activation mediated by phospho-p38-MAPK. Therefore, blocking the p38-MAPK signal pathway could inhibit this effect.

[Effects of HPA and NF-E2 related factor on smoking related laryngeal squamous cell carcinoma]

Objective:To further explore the prognostic effects of Heparanase(HPA) and NF-E2 related factor (NRF2) on smoking related laryngeal squamous cell carcinoma,we detect the expression of HPA and NRF2 on smoking related laryngeal squamous cell carcinoma patients.Method:Continuously collected 84 patients with laryngeal squamous cell carcinoma in the Ningde Hospital from 2014 to 2015.All patients were divided into three groups according to smoking index:group A (severe smoking patients with laryngeal carcinoma 30 cases),group B(mild to moderate smokers 20 cases) and group C (no smoking in laryngeal carcinoma patients with 34 cases).Antioxidative indices in serum and the expression of HPA and NRF2 in three groups of patients were detected, and to explore their relationship with prognosis and clinical staging of patients.Result:The HPA and NRF2 were highly expressed in the cancer tissues of patients with stage Ⅲ-Ⅳ,while the expression of HPA and NRF2 in patients with stage Ⅰ-Ⅱ was low. The expression level of NRF2 in group A was significantly higher than that of group Band group C(P <0.05) as well as the NRF2 expression levels in higher stage patients with laryngeal cancer were higher than those of low stages.The expression of HPA and NRF2 is related to the pathological stage in laryngeal squamous cell carcinoma patients(P <0.05).Conclusion:Compared with non smoking patients, severe smoking patients with laryngeal cancer will face more severe oxidative stress. The expression of HPA and NRF2 in laryngeal squamous cell carcinoma patients is related to the pathological stage.

SNP at miR-483-5p-binding site in the 3'-untranslated region of the BSG gene is associated with susceptibility to esophageal cancer in a Chinese population

The aim of this study was to investigate the association between a functional variant of the basigin (BSG) gene, caused by a polymorphism (rs11473) at the miR-483-5p binding site, and the risk of esophageal squamous cell carcinoma (ESCC) in the Chinese population. The rs11473 polymorphism was genotyped in 624 esophageal cancer patients and 636 cancer-free age- and gender-matched controls using polymerase chain reaction restriction and direct sequencing. The functional variants resulting from the BSG rs11473 SNP were investigated using a luciferase activity assay and validated by immunoblotting. We discovered that ESCC patients carrying the rs11473 AA genotype or A allele were at a significantly higher risk of esophageal cancer [odds ratio (OR) = 1.560, 95% confidence interval  (CI) = 1.031-2.358, P = 0.037; OR = 1.231, 95%CI = 1.038-1.459, P = 0.017, respectively] than those carrying the GG genotype and G allele. Moreover, the rs11473 polymorphism modifies the binding of miR-483- 5p to basigin, as well as the basigin protein levels in esophageal cancer patients. Our data suggested that the rs11473 polymorphism at the miR- 483-5p binding site in the 3'-UTR of basigin gene may play a key role in the development of esophageal cancer in a Chinese population.

[Physical activity level and its influence factors among residents in one suburb district of Beijing]

OBJECTIVE

To study the physical activity level and its influence factors among residents in one suburb of Beijing, so as to provide specific interventions for different people in different circumstances and to provide reference for health relevant policy-making in the future.

METHODS

In the study, 7 319 subjects aged 18 years or above were involved. The self-designed questionnaires based on Health Belief Model (HBM) had acceptable validity and reliability. The physical activity levels were calculated to classify sufficient or insufficient amount by a thousand-step equivalent greater than or equal to 6 or 10. Multiple variable Logistic regression was used to explore the influence factors of the physical activity among the residents.

RESULTS

The residents' median amount of physical activity in the suburb district of Beijing were 9.1 thousand-step equivalent with quartile of (3.8, 20.4). The percentages of the thousand-step equivalent greater than or equal to 6 or 10 were 63.7% and 47.7%, respectively. The median amounts of physical activity from work or household chores, transportation and recreation physical activities were 4.0, 1.0, 0.0 and the components of the total amount of physical activity from those were 61.7%, 18.3% and 20.1%, respectively. There were 8.6% residents whose life did notinvolve moderate or vigorous intensity activities. By using factor analysis, five factors were extracted from the scale based on the HBM; These factors together contributed to 63.7% of the sum of the squared loadings. The differences of physical activity levels on education level, age, gender, self-efficacy, cues, subjective and objective barriers were statistically significant (P<0.05).Those who were female, with older age, lower education level, higher self-efficacy, fewer cues, fewer subjective and objective barriers preferred to do more physical activities.

CONCLUSION

The physical activity levels among the residents in the suburb district of Beijing are moderate and high, and most amount of physical activities from work or household chores. Those who are male and whose ages are from 18 to 29 years and whose education levels are of university or above should be focused on intervention. Specific interventions should be developed for different people in different situations; More attention should be paid to improve the residents' self-efficacy and reduce the subjective and objective barriers of physical activity, and we also should actively advocate people to have more leisure exercise so as to improve the physical activity level among all residents.