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Using impact test to study cushioning and energy absorption of sports mouthguard of different thickness, material and combination.According to the thickness, material and combination, the mouthguards were divided into 7 groups with 6 testing pieces in each group. A pendulum device was used to apply impact energy to the mouthguard and dentition model, and the magnitude of the impact energy was measured by changing the release height of the pendulum. The force sensor and the laser vibrometer were respectively connected to the data acquisition and signal analyzer to obtain the incident speed, rebound speed, maximum collision force, collision start time and collision end time of the hammer head. Collision time, energy absorption and energy absorption ratio of the mouthguard were calculated, which reflected different mouthguard cushioning and energy absorption characteristics. One-way analysis of variance and t test in SPSS 22.0 software package was used to analyze the difference between different groups.No matter what type of mouthguard was worn by the dentition model, the impact force was significantly reduced than without mouthguards. At the same height, there was significant difference between the average maximum collision force and the average collision time among soft mouthguards with thicknesses of 2, 3, 4, and 5 mm(P0.05); among which the average maximum collision force of the 5 mm was the smallest and the average collision time was the shortest. There was no significant difference in the average energy absorption and the average energy absorption ratio among these 4 groups. There was significant difference in the average maximum collision force, average collision time, average energy absorption and average energy absorption ratio between the two groups of mouthguards with the same thickness of splints and different materials(P0.05). Among them, the average maximum impact force of the 4 mm soft mouthguard was smaller and the average collision time was longer.Wearing sports mouthguard can reduce the risk of tooth fracture during collision. Soft mouthguard has the best cushioning performance and it is positively related to thickness. Locally strengthening hard materials can enhance energy absorption and provide better protection.

Highly selective recognition of acidic amino acids, such as glutamic acid and aspartic acid, by a positively charged calixpyridinium is reported. The complexation behavior of the calixpyridinium host towards a dipeptide containing the glutamic acid residue and a glutamic acid metabolite is also described.

Based on the theory of ecological resources recycling, the effects of matrix quality, surface treatment method, soaking time, age after treatment and fluosilicate cation on hardening cement based materials were investigated by using the byproduct of phosphate fertilizer production namely fluosilicate as the surface treatment agent of cement-based materials and changing different surface treatments. The results showed that the permeation capacity of surface hardener solution , the wear resistance and surface hardness of cement-based materials were significantly improved by the treatments of surface sanding and oven drying. Both surface spraying and submerging methods can promptly increase the hardening effect by more than 20%, manifesting as the rapid improvement of wear resistance in 1 day and the maintenance of that in 7 days. The effective spraying amount and soaking time were 100g/m2-200g/m2 and 6 h, respectively. The fluosilicate surface hardener exhibited better hardening effect than the silicate surface hardener for those matrix materials with different quality, especially for the matrix materials with low compactness. The magnesium fluosilicate displayed the best hardening effect. Besides, the mechanism of fluosilicate and silicate surface hardeners were discussed and compared. The results show that the fluosilicate surface hardener produced crystals and colloids by reacting with cement hydrates to fill the void and improve the compactness, other than the silicate surface hardener which produced calcium silicates by reacting with cement hydrates. As a result, the hardness and wear resistance of cement-based materials are improved, but also the probability of a potential alkali-aggregate reaction is substantially reduced.

A high performance polycarboxylate superplasticizer (PCE) was successfully synthesized by a polymerization reaction among acrylic acid (AA), maleic anhydride (MA) and isopentenyl polyethylene glycol (IPEG) through redox initiation system. The composition and amounts of initiation system, and the ratio of monomers were investigated respectively. The proportion of IPGE: MA: AA: sodium methallyl sulfonate (SMAS): ammonium persulfate (APS): ascorbic acid (ASA) was determined as 1: 3: 1.5: 0.3: 0.015: 0.012. Moreover, the effect of polymerization temperature on PCE’s cement paste fluidity was studied. The results showed that the cement pastes mixed with PCE synthesized at 10°C, 20°C and 30°C respectively exhibited better fluidity performances than that mixed with common PCE. The Fourier Transform Infrared Spectroscopy (FTIR) measurements were used for the structural characterization. The results confirmed the occurrence of polymerization reaction and the ideal structure. Furthermore, the application performances of PCE synthesized through redox initiation system in mortar and concrete were tested. The results showed that the water reducing rate of PCE in mortar and the slump performances of PCE in concrete were better than those of the common commercial PCEs. This synthesis method presents the great research value and application prospect for the PCE preparation in concrete engineering.

In this work, cationic macrocyclic calixpyridinium was employed as a new strategy to condense DNA. Moreover, the degradation of DNA by DNase I could lead to the calixpyridinium-DNA supramolecular aggregates being dissipated. Therefore, the present system is potentially applicable as the targeted drug delivery model at DNase I-overexpressed sites.

In this work, a new type of RNA amphiphilic polymeric assembly was constructed by macrocycle-based supramolecular interactions, in which calixpyridinium was employed as the macrocyclic host. Benefitting from the probable electrostatic interactions between the pyridine cations in calixpyridinium and the phosphate anions in RNA, and the probable charge-transfer interactions between the electron-deficient pyridine cations in calixpyridinium and the electron-rich base pairs in RNA, this amphiphilic polymeric assembly could occur at a very low concentration. This polymeric assembly had superior stability and exhibited multistimuli responsiveness. The effective binding of RNA to calixpyridinium could lead to a pKa shift of the acidic methylene bridges in calixpyridinium. The RNase A-triggered disassembly of the aggregates and release of the loaded drugs suggested that this polymeric assembly was potentially applicable as a targeted drug delivery material particularly at the tissue where RNase A was overexpressed.

A novel 17β-estradiol molecularly imprinted polymer was grafted onto the surface of initiator-immobilized silica by surface-initiated atom transfer radical polymerization. The resulting molecularly imprinted polymer was characterized by elemental analysis and thermogravimetric analysis. The binding property of molecularly imprinted polymer for 17β-estradiol was also studied with both static and dynamic methods. The results showed that the molecularly imprinted polymer possessed excellent recognition capacity for 17β-estradiol (180.65 mg/g at 298 K), and also exhibited outstanding selectivity for 17β-estradiol over the other competitive compounds (such as testosterone and progesterone). Then, the determination of trace 17β-estradiol in beef samples was successfully developed by using molecularly imprinted polymer solid-phase extraction coupled with high-performance liquid chromatography. The limit of detection was 0.25 ng/mL, and the amount of 17β-estradiol in beef samples was detected at 2.83 ng/g. This work proposed a sensitive, rapid, reliable, and convenient approach for the determination of trace 17β-estradiol in complicated beef samples.

We have successfully constructed a supramolecular assembly based on the anionic recognition of calixpyridinium for the first time employing native biocompatible polysaccharide hyaluronan as the guest, which showed hyaluronidase-responsive disassembly and temperature-responsive morphological conversion from a nanosphere to a nanosquare upon increasing the temperature.

Environmental exposure to heavy metals has been linked to a wide range of human health hazards. We detected the levels of 15 metals in urine samples from 500 representative sub-samples in an ongoing occupational cohort study (Jinchang Cohort) to directly evaluate metal exposure levels. Fifteen metals, namely As, Ba, Be, Cd, Cs, Cr, Co, Cu, Pb, Mn, Ni, Se, Tl, U, and Zn, were detected by inductively coupled plasma quadruple mass spectrometry. The results showed that median creatinine adjustment and geometric mean urinary metal levels were higher in the heavy metal-exposed group, except Se and Zn, than other reported general or occupational populations. Further studies should address the effects of heavy metals on human health.

The silylating agent 3-methacryloxypropyl trimethoxysilane (MPS) was grafted on the surface of silica gel particles, then the molecular imprinting was carried out by using isoprocarb as template, methylacrylic acid (MAA) as functional monomer and ethylene glycol diglycidyl ether (EGDE) as crosslinker in the ethanol solution, and then the surface-molecular imprinted materials of isoprocarb (MIP-PMAA-MPS-SiO2) was obtained. The binding properties of MIP-PMAA-MPS-SiO2 for isoprocarb were studied with both static and dynamic methods. The experiment results showed that MIP-PMAA-MPS-SiO2 had specific recognition selectivity and excellent binding selectivity for the template molecule. In respect to the reference substance tsumacide and carbaryl, its selectivity coefficient for isoprocarb was 6.73 and 8.95, respectively. The relative selectivity coefficient was 4.43. After the Scatchard analysis, Qmax (the apparent maximum binding amount) values were calculated to be 229.6 and 116.7 mg g−1, respectively, and the dissociation constant (Kd) values were calculated to be 1428.6 and 476.2 mg L−1, respectively. Besides, the spiked recovery in rape samples experiment showed that imprinted material of MIP-PMAA-MPS-SiO2 can enrich and separate for trace amounts of isoprocarb, and it was also easy to be used repeatedly.

The main purpose of this study was to prepare a novel in situ gel system for nasal delivery of MF and study its efficacy on allergic rhinitis model. An ion-activated in situ gel was developed and characterized with gellan gum as a carrier. The system was stable kept at 40+/-2 degrees C for 6 months, and the micrographic results showed that in situ gel was safety without mucosa irritation when given at 20 microg once daily for 1 month to rats with allergic rhinitis. MF in gellan gum produced obviously effect on allergic rhinitis at the doses of 20 microg/body following intranasal administration, and the efficacy was significantly superior to that of the common suspension (P

To study the association between metal exposure and risk of diabetes and prediabetes among Chinese workers exposed to metals.We used data obtained from the baseline survey of the Jinchang Cohort Study of workers in Jinchang Industry, the largest nickel production company in China. A total of 42,122 workers ⋝20 years of age were included in the study. A standardized, structured questionnaire was used to collect epidemiological information. Physical examinations and laboratory tests were conducted to evaluate the health status of the participants and to measure various biomarkers including blood sugar, lipids, and urinary metal concentrations. Logistic regression was used to study the association between occupational groups categorized according to the measured metal levels (office workers, low-level; mining/production workers, mid-level; and smelting/refining workers, high-level) and risk of diabetes and prediabetes.The overall prevalence of diabetes and prediabetes was 7.5% and 16.8%, respectively. The adjusted odds ratios for diabetes among mining/production workers and smelting/refining workers compared to office workers were 1.5 (95% CI: 1.3, 1.7) and 3.8 (95% CI: 3.4, 4.3), respectively. No association was observed between these occupational groups and prediabetes in this study.Occupations associated with higher levels of metal exposure were associated with an increased risk of diabetes in this cohort. More studies are needed to confirm this observed association.

To describe the baseline data of cancers in the Jinchang Cohort, this paper examined trends in cancer mortality among adults investigated in Jinchang, Gansu province from 2001 to 2010.Mortality data were collected from company departments through administrative documents, death certificates, etc. Trend analyses of cancer mortality were performed on the basis of 925 cancer deaths between 2001 and 2010.The crude mortality rate of cancer continuously increased from 161.86 per 100,000 in 2001 to 315.32 per 100,000 in 2010, with an average increase of 7.69% per year in the Jinchang Cohort (16.41% in females compared to 6.04% in males), but the age-standardized mortality rate increased only in females. Thirteen leading cancers accounted for 92.10% of all cancer deaths. The five leading causes of cancer mortality in males were lung, gastric, liver, esophageal, and colorectal cancer, whereas those in females were lung, liver, gastric, breast, and esophageal cancer.The overall cancer mortality rate increased from 2001 to 2010 in the Jinchang Cohort, with greater rate of increase in females than in males. Lung, breast, and gastric cancer, in that order, were the leading causes of increased cancer mortality in females.

Statement of problem Selective laser melting (SLM) is a new technique for fabricating dental restorations, but the metal–ceramic bond strength of the restorations after multiple firings must be considered because adequate bond strength is a clinical requirement for long-term performance. Purpose The purpose of this study was to investigate the effects of repeated firing on the metal–ceramic bond strength of an SLM Co-Cr alloy. Material and methods Thirty-six SLM-fabricated (Group SLM) and conventional lost wax cast (Group Cast) Co-Cr metal bars were prepared. Eighteen bars from each group were molded into dimensions of 25×3×0.5 mm, following International Organization for Standardization (ISO) standard 9693:2012. In the center of each bar, a 1.1-mm thickness of porcelain was fused onto an 8×3-mm rectangular area. In each group, specimens were divided into 3 subgroups based on the number of firing cycles (3, 5, 7) for the veneering process. Metal-ceramic bond strength, fracture mode analysis, and area fraction of adherence porcelain (AFAP) of each subgroup was evaluated with a 3-point bend test and by measuring the Si content of specimens with scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). The results were statistically analyzed first with the Shapiro-Wilk test, where a P value of .364 was considered normally distributed, and then with the Student t test to determine significant differences (α=.05). Results Student t test results showed no statistical differences between the metal-ceramic bond strength of SLM and that of conventionally cast groups after firing 3, 5, and 7 times ( P >.05). However, after SEM/EDS analyses, the SLM group showed significantly more porcelain adherence than that of the control group ( P Conclusions The SLM group showed superior metal-ceramic bond strength that exceeded ISO 9691:1999 (E) requirements at all firing periods. Also, the bond showed better behavior in terms of AFAP than the conventional cast group, especially after 5 or 7 firings.

The prevalence of metabolic syndrome (MS) was investigated in Chinese nickel-exposed workers. A total of 35 104 subjects were enrolled in this study. The age-adjusted prevalence of MS, BMI⋝25, diabetes, hypertension, and abnormal lipid was 13.9%, 29.5%, 12.8%, 27.5%, and 47.1%, respectively. The prevalence of BMI⋝25, hyperglycemia, and hypertension increased with the age of males and females, and was higher in males than in females (37.1% vs 21.5%, 15.9% vs 12.1%, 35.0% vs 24.3%, 54.3% vs 40.4%).

To understand the epidemiological trend on the number of influenza-like cases and to explore the feasibility of early warning systems of influenza in Gansu province.Based on data from the influenza sentinel surveillance program, a sequence chart was used to analyze the epidemiological trend on the number of influenza-like illness (ILI) cases. Both control chart and mobile percentile method were used to select the threshold of premium alert for the ILI of sentinel surveillance program. Warning effects were assessed by statistical model.The prevalence of influenza were both low in 2007 and 2008. Alert thresholds for ILI of Sentinel surveillance was built. The thresholds were higher alert in winter, but lower in summer. Both Seasonal Exponential Smoothing Model and Multiplicative Seasonal ARMA Model (1, 1, 1) (0, 1, 0) were used to dynamically predict the weekly percentage of outpatient visits for influenza-like illness (ILI%) of 2011. The concordance rates (predicted = actual) were 100% for both of them. According to the RMSE values, the dynamically predicted effect of the seasonal exponential smoothing model was superior to ARIMA.Dynamic prediction on the number of influenza-like cases could reflect the epidemiological trend of influenza in Gansu province, but with some limitations.

Continued rapid evolution of the influenza A virus is responsible for annual epidemics and occasional pandemics in the Shanghai area. In the present study, the representative strains of A/H1N1 and A/H3N2 influenza viruses isolated in the Shanghai area from 2005 to 2008 were antigenically and genetically characterized. The antigenic cartography method was carried out to visualize the hemagglutination-inhibition data. Antigenic differences were detected between circulating A/H1N1 strains isolated from 2005 to 2006 and the epidemic A/H1N1 strains isolated in 2008, which were found to be associated with the amino acid substitution K140E in HA1. The present vaccine strain A/Brisbane/59/2007 is considered to be capable of providing sufficient immunity against most of the circulating A/H1N1 viruses isolated in 2008 from the Shanghai population. The study showed that there were significant antigenic differences between the epidemic A/H3N2 strains isolated in 2007 and 2008, suggesting that antigenic drift had occurred in the A/H3N2 strains isolated in 2008. The P194L mutation was thought to be responsible for the antigenic evolution of influenza A/H3N2 viruses isolated from Shanghai in 2008. Evidence of antigenic drift suggests that the influenza A/H3N2 vaccine component needs to be updated.

The purpose of this cross-sectional study was to evaluate the quality of life (QOL) of coal dust workers without pneumoconiosis in mainland China. Three hundred five coal dust workers and 200 non-dust workers without pneumoconiosis from five coal mines in Shanxi province were enrolled in this study. The Chinese World Health Organization Quality of Life-brief version (WHOQOL-BREF) questionnaire was used. Socio-demographic, working, and health factors were also collected. Multiple stepwise regression analysis was used to identify significant factors related to the four domain scores of WHOQOL-BREF. All functional domains of the Chinese WHOQOL-BREF were significantly worse in coal dust workers compared to non-dust workers except for psychological health. For the physical domain of QOL, educational level, working hours, and work danger were the significant factors. In the psychological domain, types of job, welfare satisfaction, work danger, hobbies, smoking, one-child family, and marital status were the predictive factors. Working hours, welfare satisfaction, educational level, and birthplace were the predictive factors for the social domain of QOL. Finally, the predictors for the environmental domain of QOL were types of job, working hours, welfare satisfaction, work danger, self-reported social status, smoking, and drinking. Coal dust workers without pneumoconiosis had worse QOL than non-dust workers but their subjective feelings were positive. There were four distinct models for the various domains of QOL. Corresponding health policies could be developed to improve their QOL.

Conditionally replicative adenovirus (CRAd) mediated tumor specific gene therapy based on transcriptional control is considered a new direction for the treatment of cancer. Our previous studies showed that an HS4 insulator increased the alpha-fetoprotein (AFP) promoter-driven expression in the context of an adenovirus (Ad) vector, while retaining the highly specific gene expression in hepatoma cells in vitro and in vivo. In this study, we constructed two HS4-AFP promoter based CRAd vectors (Ad.HS4.AFP.E1a/TRAIL and Ad.HS4.AFP.E1a) with and without the expression cassette of TNF-related apoptosis-inducing ligand (TRAIL). The TRAIL-expressing virus vector, Ad.HS4.AFP.E1a/TRAIL, exhibited more obvious oncolytic effect than Ad.HS4.AFP.E1a in both high-AFP-producing HCC cell lines (Hep3B and HUH7) and a low-AFP-producing HCC cell line (PLC/PRF/5) examined, indicating endogenous TRAIL over-expression increased CRAd potency. The enhanced hepatoma cell death was mainly mediated through apoptotic mechanism, as evidenced by the activation of caspase-3, binding of annexin V and inhibition by caspase inhibitor z-vad-fmk. In s.c. xenograft of low-AFP-producing PLC/PRF/5 hepatoma model, the administration of Ad.HS4.AFP.E1a/TRAIL resulted in a more potent oncolytic effect compared with the same dose of Ad.HS4.AFP.E1a 28 days after virus exposure. This study demonstrated that the TRAIL in the context of a CRAd vector was able to increase the oncolytic activity in low-AFP-producing HCC cells in vitro and in vivo. Considering that oncolytic viruses destroy tumor cells expressing low levels of the tumor marker is a clinical concern, TRAIL might be a useful tool to improve the efficacy of these vectors.

We have constructed a new capsid-modified adenovirus (Ad) vector that specifically replicates in tumor cells and expresses TNF-related apoptosis-inducing ligand (TRAIL). The Ad capsid contains short-shafted fibers derived from Ad serotype 35, which allow for efficient infection of malignant tumor cells, and largely avoids innate toxicity after intravenous application. Replication-dependent homologous recombination in Ad genomes was used to achieve tumor-specific expression of Ad E1a (to mediate viral replication) and TRAIL (to mediate apoptosis and enhance release of progeny virus from infected cells). We demonstrated that our oncolytic vector (Ad5/35.IR-E1A/TRAIL) induced apoptosis in human tumor cell lines derived from colorectal, lung, prostate, and liver cancer. Both in vitro and in vivo tumor models showed efficient intratumoral spread of this vector. In a model for metastatic colon cancer, tail vein infusion of Ad5/35.IR-E1A/TRAIL resulted in elimination of preestablished liver metastases. Intravenous injection of this vector caused a transient elevation of serum glutamic pyruvic transaminase in tumor-bearing mice, which we attributed to factors released from apoptotic tumor cells. Liver histology analyzed at day 14 after virus injection did not show signs of hepatocellular damage. This new oncolytic vector represents a potentially efficient means for gene therapy of metastatic cancer.