[Analysis on risk factors of screen time among Chinese primary and middle school students in 12 provinces]

OBJECTIVE

To investigate the characteristics of screen time and its risk factors in Chinese primary and middle school students.

METHODS

During April 2012 and June 2012, according to the geographical distribution, the stratified random cluster sampling method was used to select 4 provinces from eastern, central and western China, respectively. The convenience sampling method was used to select 2 primary and middle schools from urban, 2 primary and middle schools from rural in each province. In each school, all grades were included, and 2 classes were selected in each grade. A total of 51 866 students or parents were selected as study participants, and 43 771 questionnaires were valid. Information on demographics, academic performance, screen time (TV, computer and cellphone) at weekdays and weekends and the prevalence of the high screen time were compared, multivariate logistic regression was used to analyze the association between screen time >2 h/d and potential influential factors.

RESULTS

The percentage of students with screen time >2 h/d at weekdays and weekends were 16.2% (7 082/43 771) and 41.5% (18 141/43 771) (χ(2)=6 280.14, P<0.001), respectively. The distribution of P50 (P25-P75) for screen time at weekdays and weekends were 0.9(0.4-1.6) and 1.8(1.0-3.0) (Z=-131.26, P<0.001), respectively. The results of multinomial logistic regression analysis showed that, at weekdays, subjects characterized as primary school students, boys, urban area, living in western area and sufficient vigorous physical activity ≤2 d/w had higher risk for screen time >2 h/d than those characterized as elementary school students, girls, rural area, living in eastern area and sufficient vigorous physical activity >3 d/w, odds ratio were 2.01, 1.54, 1.21, 1.09, and 1.07, respectively (P<0.05 for all); subjects characterized as a normal or worse self rating academic performance had higher risk for screen time >2 h/d than those characterized as a good self rating academic performance, odds ratioes were 1.24 and 1.73, respectively (P<0.05 for all); subjects characterized as paternal education level as elementary school, middle school, high school or secondary school had higher risk for screen time >2 h/d than those characterized as paternal education level as college school or high, odds ratioes were 1.41, 1.47 and 1.52, respectively (P<0.05 for all); subjects characterized as maternal education level as elementary school, middle school and high school or secondary school had higher risk for screen time >2 h/d than those characterized as maternal education level as college, odds ratioes were 1.40, 1.52 and 1.47, respectively (P<0.05 for all). At weekends, subjects characterized as primary school students, boys, urban area and sufficient vigorous physical activity ≤2 d/w had higher risk for screen time >2 h/d than those characterized as elementary school students, girls, rural area and sufficient vigorous physical activity >3 d/w, odds ratioes were 2.11, 1.51, 1.20 and 1.05, respectively (P<0.05 for all). At weekends, subjects characterized as a normal or worse self rating academic performance had higher risk for screen time >2 h/d than those characterized as a good self rating academic performance, odds ratioes were 1.09 and 1.26, respectively (P<0.05 for all); subjects characterized as paternal education level as elementary school, middle school, high school or secondary school had higher risk for screen time >2 h/d than those characterized as paternal education level as college school or high, odds ratioes were 1.29, 1.30 and 1.19, respectively (P<0.05 for all); subjects characterized as maternal education level as elementary school, middle school had higher risk for screen time >2 h/d than those characterized as maternal education level as college school or high, odds ratioes were 1.19 and 1.16 and, respectively (P<0.05 for all).

CONCLUSION

The prevalence of screen time >2 h/d is high; screen time at weekdays is longer than weekends, and there are significant differences among different sexes, urban or rural areas, living areas, self rating academic performance, parents education levels and physical activity groups.

The influence of positive selection and trans-species evolution on DPB diversity in the golden snub-nosed monkeys (Rhinopithecus roxellana)

Genetic variation plays a significant role in the adaptive potential of the endangered species. The variation at major histocompatibility complex (MHC) genes can offer valuable information on selective pressure related to natural selection and environmental adaptation, particularly the ability of a host to continuously resist evolving parasites. Thus, the genetic polymorphism on exon 2 of the MHC DPB1 gene in the golden snub-nosed monkeys (Rhinopithecus roxellana) was specifically analyzed. The results show that the 6 Rhro-DPB1 alleles identified from 87 individuals exhibit positive selection and trans-species polymorphism. The results also imply that although the populations of the species have experienced dramatic reduction and severe habitat fragmentation in recent Chinese history, balancing selection still maintains relatively consistent, with moderate DPB1 polymorphism. Thus, the study provides valuable information and evidence in developing effective strategies and tactics for genetic health and population size expansion of the species. It also offers strong genetic background for further studies on other primate species, particularly those in Rhinopithecus-a further endeavor that would result in fully understanding the MHC genetic information of the Asian colobines.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

Robust Control Design of Uncertain Mechanical Systems: A Fuzzy Approach

We first investigate the fundamental properties of the mechanical system as related to the control design. Then a new robust control is proposed for mechanical systems with fuzzy uncertainty. Fuzzy set theory is used to describe the uncertainty in the mechanical system. The desirable system performance is deterministic. The proposed control is deterministic and is not the usual if-then rules-based. The resulting controlled system is uniformly bounded and uniformly ultimately bounded proved via the Lyapunov minimax approach. The resulting control design is systematic and is able to render the deterministic performance. A mechanical system is chosen for demonstration.

[Value of R2(*) in evaluating the biological behavior of primary hepatocellular carcinoma]

OBJECTIVE

To investigate the correlation between R2(*) value of enhanced T2 star-weighted angiography (ESWAN) sequence and primary hepatocellular carcinoma infiltration and tumor thrombus, and investigate the biological behavior of HCC.

METHODS

A total of 221 cases of patients' imaging data with MRI examination(including ESWAN sequence) diagnosed as primary HCC were retrospectively analyzed.All the patients were collected from January 2014 to September 2015 in the First Affiliated Hospital of Dalian Medical University.The differences of R2(*) values in different MR types of HCC were analyzed.All patients were divided into infiltration group and non-infiltration group, tumor thrombus group and non-tumor thrombus group, the R2(*) values of the paired groups were compared.The diagnostic efficiency of R2(*) in HCC infiltration and tumor thrombus were evaluated by ROC curve, and to find out the threshold values.

RESULTS

The MR types of 221 patients included 90 cases of nodular type, 62 cases of massive type, 69 cases of diffuse type.70 patients had tumor thrombus.The R2(*) values of different MR types were (21.82±8.52), (24.17±8.84)and (34.45±11.73) Hz, respectively.There was no statistically significant difference between the nodular and the massive types (P=0.144), while the difference between the nodular and diffuse type, the massive and diffuse types were statistically significant(P=0.000). The R2(*) values of infiltration group and non-infiltration group were (34.45±11.73) and (22.78±8.70) Hz , the R2(*) values of tumor thrombus group and non-tumor thrombus group were (31.20±12.17) and (24.21±9.90) Hz, the difference also had statistically significant(t=7.397 and 4.534, P=0.000 and 0.000). The AUC of R2(*) values for infiltration and tumor thrombus were 0.804, 0.681. R2(*) ≥24.68 Hz was the threshold value to diagnose the infiltration and tumor thrombus.

CONCLUSION

R2(*) value can be used as a MR non-enhancement quantitative index to evaluate the biological behavior of HCC.

Monocyte cell membrane-derived nanoghosts for targeted cancer therapy

Core-shell type 'nanoghosts' were synthesized with a drug-loaded biodegradable PLGA core and a monocyte cell membrane-derived shell. The nanoghosts were monodisperse with an average size <200 nm, and showed good serum stability for 120 h. Doxorubicin-loaded nanoghosts showed greater cellular uptake and cytotoxicity compared to non-coated nanoparticle controls in metastatic MCF-7 breast cancer cell lines.

Induced membrane technique for the treatment of bone defects due to post-traumatic osteomyelitis

Objectives

Induced membrane technique is a relatively new technique in the reconstruction of large bone defects. It involves the implantation of polymethylmethacrylate (PMMA) cement in the bone defects to induce the formation of membranes after radical debridement and reconstruction of bone defects using an autologous cancellous bone graft in a span of four to eight weeks. The purpose of this study was to explore the clinical outcomes of the induced membrane technique for the treatment of post-traumatic osteomyelitis in 32 patients.

Methods

A total of 32 cases of post-traumatic osteomyelitis were admitted to our department between August 2011 and October 2012. This retrospective study included 22 men and ten women, with a mean age of 40 years (19 to 70). Within this group there were 20 tibias and 12 femurs with a mean defect of 5 cm (1.5 to 12.5). Antibiotic-loaded PMMA cement was inserted into the defects after radical debridement. After approximately eight weeks, the defects were implanted with bone graft.

Results

The patients were followed for 27.5 months (24 to 32). Radiographic bone union occurred at six months for 26 cases (81%) and clinical healing occurred in 29 cases (90%) at ten months. A total of six cases had a second debridement before bone grafting because of recurrence of infection and one patient required a third debridement. No cases of osteomyelitis had recurred at the time of the last follow-up visit.

Conclusion

The induced membrane technique for the treatment of post-traumatic osteomyelitis is a simple, reliable method, with good early results. However, there are many challenges in determining the scope of the debridement, type of limb fixation and source of bone graft to be used.

Cite this article: Dr Z. Xie. Induced membrane technique for the treatment of bone defects due to post-traumatic osteomyelitis. Bone Joint Res 2016;5:101–105. DOI: 10.1302/2046-3758.53.2000487.

Subnanometer Two-Dimensional Graphene Oxide Channels for Ultrafast Gas Sieving

Two-dimensional (2D) materials with atomic thickness and extraordinary physicochemical properties exhibit unique mass transport behaviors, enabling them as emerging nanobuilding blocks for separation membranes. Engineering 2D materials into membrane with subnanometer apertures for precise molecular sieving remains a great challenge. Here, we report rational-designing external forces to precisely manipulate nanoarchitecture of graphene oxide (GO)-assembled 2D channels with interlayer height of ∼0.4 nm for fast transporting and selective sieving gases. The external forces are synergistic to direct the GO nanosheets stacking so as to realize delicate size-tailoring of in-plane slit-like pores and plane-to-plane interlayer-galleries. The 2D channels endow GO membrane with excellent molecular-sieving characteristics that offer 2-3 orders of magnitude higher H2 permeability and 3-fold enhancement in H2/CO2 selectivity compared with commercial membranes. Formation mechanism of 2D channels is proposed on the basis of the driving forces, nanostructures, and transport behaviors.

Optogenetic dissection of ictal propagation in the hippocampal-entorhinal cortex structures

Temporal lobe epilepsy (TLE) is one of the most common drug-resistant forms of epilepsy in adults and usually originates in the hippocampal formations. However, both the network mechanisms that support the seizure spread and the exact directions of ictal propagation remain largely unknown. Here we report the dissection of ictal propagation in the hippocampal-entorhinal cortex (HP-EC) structures using optogenetic methods in multiple brain regions of a kainic acid-induced model of TLE in VGAT-ChR2 transgenic mice. We perform highly temporally precise cross-area analyses of epileptic neuronal networks and find a feed-forward propagation pathway of ictal discharges from the dentate gyrus/hilus (DGH) to the medial entorhinal cortex, instead of a re-entrant loop. We also demonstrate that activating DGH GABAergic interneurons can significantly inhibit the spread of ictal seizures and largely rescue behavioural deficits in kainate-exposed animals. These findings may shed light on future therapeutic treatments of TLE.

Effects of Ang Ⅱ perfusion on transmural heterogeneous of Cx43 in acute myocardial ischemia reperfusion

OBJECTIVE

To observe the effects of angiotensin Ⅱ(Ang Ⅱ) perfusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion (MIR), and investigate the role of rennin-angiotensin system in malignant ventricular arrhythmia induced by MIR.

METHODS

Twenty rabbits were randomly divided into MIR group (n = 10) and Ang Ⅱ group (n = 10). MIR model was produced with traditional ligation and opening of the anterior descending coronary artery in all animal. The hearts in vitro in the MIR group and the Ang Ⅱ group were perfused with simply improved Tyrode's solution and containing Ang Ⅱ Tyrode's solution respectively. 90% monophasic action potential repolarization duration, transmural dispersion of repolarization, Cx43 protein (Cx43-pro) and mRNA (Cx43-Cq) expression in subepicardial, midmyocardial and subendocardial myocardium were measured in both groups. The greatest differences of Cx43-pro and Cx43-Cq among three myocardial layers were calculated and shown with ΔCx43-pro and ΔCx43-Cq respectively.

RESULTS

After Ang Ⅱ perfusion, 90% monophasic action potential repolarization duration among three myocardial layer were significantly prolonged (P < 0.05 and P < 0.01), and transmural dispersion of repolarization also significantly increased compared with the MIR group (P < 0.05). Compare with the MIR group, three myocardial Cx43-pro and Cx43-Cq expression in the Ang Ⅱ group were significantly decreased (P < 0.05 and P < 0.01), but ΔCx43-pro and ΔCx43-Cq were significant increased.

CONCLUSIONS

Renin-angiotensin system increases transmural heterogeneity of Cx43 expression in the rabbit model with MIR by Ang Ⅱ, and enlarge transmural dispersion of repolarization among three myocardial layers of left ventricular which induces malignant ventricular arrhythmia.

De novo assembly and characterization of Gleditsia sinensis transcriptome and subsequent gene identification and SSR mining

Gleditsia sinensis is a Chinese native deciduous tree with a high economic and medicinal value. However, there is limited knowledge on the molecular processes responsible for the medical properties of this species owing to lack of bioinformatic resources such as available whole-genome sequences. In the present study, RNA sequencing data were used to analyze the transcriptome of G. sinensis, and a series of bioinformatic tools was used to explore the main genes involved in important molecular processes. A total of 75.57 million paired-end reads, with a length of 101 bp, were acquired from G. sinensis. Using the assembly tool Trinity, 233,751 transcripts were discovered. Among these, 85,795 were identified as unique transcripts and 59,326 unique transcripts were found to contain coding regions. Gene ontology analysis identified 27,637 unique transcripts that were clustered into 56 functional groups. Genes involved in flavonoid and terpenoid backbone biosynthesis and those encoding transcription factors were further analyzed. Sequence analysis revealed four putative G. sinensis chalcone isomerase genes (GsCHI) encoding the enzymes for flavonoid biosynthesis. GsCHI1 was found to be phylogenetically related to the chalcone isomerase of the family Leguminosae, and its transcript levels in different tissues were higher than those of GsCHI2, GsCHI3, and GsCHI4. Furthermore, 15,014 simple sequence repeat (SSR) markers were discovered in the transcript library, and 5170 primers were generated for the SSR loci. The genetic and genomic information presented in this study will be helpful for future studies on gene discovery and molecular processes in G. sinensis.

Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel

Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm(-2). Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm(-2) of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment.

Effects of exogenous protease supplementation on endogenous trypsin activity and gene expression in broilers

Two hundred and forty one-day-old male broiler chickens (Ross-308) were fed corn-soybean basal diets with 0, 40, 80, or 160 mg/kg of an acid protease preparation from 1 to 42 days of age, in order to investigate the effects of an exogenous enzyme on growth performance, pancreatic trypsin activity and mRNA expression. Average daily gain (ADG) was greatest in the 160-mg/kg treatment group at 1-21 days, which was significantly higher than that in the control. After 42 days, average daily feed intake (ADFI) and ADG had significantly increased in the 80- and 160-mg/kg treatments (P < 0.05), with the 80-mg/kg treatment group having the highest ADFI and ADG values. The feed conversion ratio was not affected. Dietary acid protease at 80 and 160 mg/kg significantly decreased trypsin activity in the pancreas (relative to the control group) by 35.71 and 47.29%, respectively (P < 0.05). After 42 days, trypsin mRNA expression in the pancreas had significantly decreased by 19.5% in the 80-mg/kg treatment group relative to the control (P < 0.05). After 21 and 42 days, the diet supplemented with 160 mg/kg acid protease significantly decreased pancreatic trypsin mRNA by 19.6 and 37.7%, respectively, compared to the control. There were the 40-mg/kg treatment group and the control. Our results suggest that the amount of acid protease in the diet significantly affects trypsin activity and mRNA expression in broilers.

Maternal pre-pregnancy BMI and adverse pregnancy outcomes among Chinese women: Results from the C-ABCS

The aim of this study was to investigate associations between pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes among Chinese pregnant women. A prospective population-based cohort study was performed using data collected as part of the China-Anhui Birth Cohort Study or C-ABCS. A total of 13,121 pregnant women who received the first prenatal visit were enrolled from November 2008 to October 2010. Logistic regression analysis was used to calculate associations between pre-pregnancy BMI and pregnancy outcomes. Results indicated that the increased pre-pregnancy BMI was associated with a number of adverse pregnancy outcomes such as hypertensive disorder (adjusted relative risk (ARR) 2.3, 95% confidence interval [CI] 1.5-3.6), gestational diabetes (ARR 3.5, 95% CI 2.3-5.2), caesarean delivery (ARR 2.0, 95% CI 1.6-2.4), and medically indicated preterm delivery (ARR 1.8, 95% CI 1.1-2.9). Women with pre-pregnancy BMI above the normal range pose an increased risk of adverse pregnancy outcomes.

Nanoimprinted Patterned Pillar Substrates for Surface-Enhanced Raman Scattering Applications

A pragmatic method to deposit silver nanoparticles on polydopamine-coated nanoimprinted pillars for use as surface-enhanced Raman scattering (SERS) substrates was developed. Pillar arrays consisting of poly(methyl methacrylate) (PMMA) that ranged in diameter from 300 to 500 nm were fabricated using nanoimprint lithography. The arrays had periodicities from 0.6 to 4.0 μm. A polydopamine layer was coated on the pillars in order to facilitate the reduction of silver ions to create silver nucleation sites during the electroless deposition of sliver nanoparticles. The size and density of silver nanoparticles were controlled by adjusting the growth time for the optimization of the SERS performance. The size of the surface-adhered nanoparticles ranged between 75 and 175 nm, and the average particle density was ∼30 particles per μm(2). These functionalized arrays had a high sensitivity and excellent signal reproducibility for the SERS-based detection of 4-methoxybenzoic acid. The substrates were also able to allow the SERS-based differentiation of three types of bacteriophages (λ, T3, and T7).