An entirely enclosed scanning tunnelling microscope capable of being fully immersed in liquid helium

We present an ultrahigh-vacuum (UHV)-sealed high-stability scanning tunnelling microscope (STM) that can be entirely immersed in liquid helium and readily used in a commercial Dewar or superconducting magnet. The STM head features a horizontal microscanner that can become standalone and ultrastable when the coarse approach inertial motor retracts. Low voltage is enough to operate the STM even at low temperature owing to the powerful motor. It is housed in a tubular chamber of 49 mm outer diameter, which can be pumped via a detachable valve (DV), UHV-sealed and remain sealed after the DV is removed. The entire so-sealed chamber can then be inserted into liquid helium, where in situ sample cleavage is done via vacuum bellow. This allows sample cleavage and STM measurements to take place in better UHV with higher cooling power. Quality atomic resolution images of graphite and charge density wave on 1T-TiSe₂ taken in ambient and 14 K conditions, respectively, are presented.

Effect of peer support on diabetes distress: a cluster randomized controlled trial

AIM

To investigate whether peer support would reduce diabetes distress and improve glycaemic control when added to usual diabetes education among adults with Type 2 diabetes in China.

METHODS

We conducted a cluster randomized trial involving 400 adults with Type 2 diabetes from eight communities in Nanjing. All participants received usual education for an average of 2 h each month from physicians, certified diabetes educators, dieticians, psychologists and podiatric nurses. Peer support was led by trained peer leaders and included diabetes knowledge- and skills-sharing at least once a month, as well as peer-to-peer communication. The primary outcome was diabetes distress measured using the Diabetes Distress Scale at 12 months. Secondary outcomes included fasting plasma glucose, 2-h postprandial glucose and HbA_1c concentration. Outcome data were collected from all participants at baseline, 6 months and 12 months.

RESULTS

From 2012 to 2013, there were 200 participants in each study arm at baseline. Compared with the usual education arm, the peer support with usual education arm had greater reductions in regimen-related distress (1.4 ± 0.6 vs 1.2 ± 0.4; P=0.004) and total distress (1.3 ± 0.4 vs 1.2 ± 0.3; P=0.038) at 6 months. At 12 months, the scores for emotional burden (1.2 ± 0.3 vs 1.4 ± 0.6; P=0.002), physician-related distress (1.1 ± 0.3 vs 1.3 ± 0.4; P=0.001) and total scores (1.2 ± 0.3 vs 1.3 ± 0.4; P=0.002) were significantly lower in the peer support with usual education arm than in the usual education arm. Fasting plasma glucose levels were lower in the peer support with usual education arm than in the usual education arm at 6 months (7.5 ± 1.95 vs 8.0 ± 2.2; P=0.044) and 12 months (7.0 ± 2.3 vs 7.6 ± 1.5; P=0.008).

CONCLUSIONS

Beyond the benefits of usual education, peer support was effective in reducing diabetes distress for Type 2 diabetes mellitus. (Clinical Trials Registry no: NCT02119572).

Combining the randomized response technique and the network scale-up method to estimate the female sex worker population size: an exploratory study

OBJECTIVES

Recall bias, barrier effects, transmission error, and response bias affecting the network scale-up method (NSUM) led the Joint United Nations Programme on HIV/AIDS and the World Health Organization to designate NSUM as a developing method for estimating the size of high-risk populations in 2010. The method has subsequently been adjusted for three of these biases. The present study, therefore, aimed to explore the combination of the randomized response technique (RRT) and NSUM to adjust the last remaining bias.

STUDY DESIGN

RRT was used in an NSUM survey to estimate the population proportion of female sex workers (FSWs) in Taiyuan, China, in 2012.

METHODS

Multiplier method estimates and national-level estimates of the population proportion of FSWs were used as criteria to assess the aforementioned results.

RESULTS

Successful interviews were completed with 96.4% of the respondents selected for the NSUM survey. The NSUM estimate fell within the range of the national-level estimates of the population proportion of FSWs in Asia and was close to the estimate yielded by the multiplier method.

CONCLUSIONS

In the present study, the combination of RRT and NSUM obtained a high response rate and produced a reliable estimate of the size of a high-risk population.

[Correlation of Genetic Polymorphism, Alcoholic Beverage Type and Ethanol Metabolism]

OBJECTIVES

To explore the effects of ADH1B and ALDH2 gene polymorphism and type of alcoholic beverage on ethanol metabolism, to provide data support for cases involving the interpretation of ethanol metabolism or back calculation of blood ethanol concentration in forensic practice.

METHODS

A total of 81 volunteers were selected. The genotypes of ADH1B, ADH1C and ALDH2 were obtained by a multiplex SNaPshot genotyping method. Each subject was administered with 1.0 g/kg of alcohol. About 1 mL venous blood was collected before and after the alcohol consumption at 30 min, 45 min, 1 h, 1.5 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h and 8 h, respectively. The concentrations of ethanol and acetaldehyde in blood were determined by headspace gas chromatography. The peak times of blood ethanol concentration （T_max）, the peak mass concentrations of ethanol （C_max）, the area under curve （AUC） of ethanol （AUC_ethanol）, AUC_acetaldehyde and ethanol elimination rates （_β） were calculated. In order to eliminate the influence of ADH1C, the ADH1C*1/*1 carriers were grouped based on the genotype of ADH1B and ALDH2. The data of each group were evaluated by one-way analysis of variance and pairwise comparison tests were performed by least significant difference method. The gene interactions were evaluated by two-way analysis of variance. Each parameter of three kinds of alcoholic beverage （white wine, red wine and beer） among groups was analysed by variance analysis with randomized block design.

RESULTS

There were no differences in the value of T_max and C_max between the groups with different ADH1B and ALDH2 genotype. The differences in the values of AUC_ethanol, _β and AUC_acetaldehyde among some groups carrying different ADH1B and ALDH2 genotype had statistical significance, while no significant difference was observed in these parameters when one individual taking same dose of different alcoholic beverage type.

CONCLUSIONS

The ethanol metabolism is associated with the related gene polymorphism, which is barely affected by alcoholic beverage type.

Interpreting carbapenem susceptibility testing results for Pseudomonas aeruginosa

OBJECTIVES

Carbapenems are among the most powerful antipseudomonal agents. Limited data is available on drug susceptibility testing by routine methods (disc diffusion and Etest) for meropenem and doripenem. We aimed to compare the in vitro activity of imipenem, meropenem, and doripenem against Pseudomonas aeruginosa.

METHODS

A total of 311 P. aeruginosa strains isolated from respiratory specimens in 170 patients who developed ventilator-associated pneumonia in two intensive care units were collected over a period of 31 months. The susceptibility of these isolates to imipenem, meropenem, and doripenem were determined by Etest and disc diffusion method.

RESULTS

Considering either all isolates or only the first isolates recovered per patient (311 and 170 respectively), the susceptibility rate for doripenem was higher than that for meropenem and imipenem. When MICs determined by Etest were converted into interpretative categories (S, I, R) using French (CA-SFM) guidelines, a poor correlation was observed for meropenem and doripenem. The percentages of correlation with the disc diffusion method were 90.6% and 89.7% for imipenem, 80.5% and 82.6% for meropenem, and 80.5% and 73.3% for doripenem, for the first isolates and all isolates, respectively. The rate of minor errors was as high as 17.7% and 16.1% for meropenem and 17.7% and 25.7% for doripenem for the first isolates and all isolates, respectively.

CONCLUSION

The accuracy of disc diffusion using CA-SFM guidelines appears unsatisfactory for all three carbapenems justifying guideline update for P. aeruginosa and carbapenems.

A new locus regulating MICALL2 expression was identified for association with executive inhibition in children with attention deficit hyperactivity disorder

Impaired executive inhibition is a core deficit of attention deficit hyperactivity disorder (ADHD), which is a common childhood-onset psychiatric disorder with high heritability. In this study, we performed a two-stage genome-wide association study of executive inhibition in ADHD in Han Chinese. We used the Stroop color-word interference test to evaluate executive inhibition. After quality control, 780 samples with phenotype and covariate data were included in the discovery stage, whereas 922 samples were included in the replication stage. We identified one new significant locus at 7p22.3 for the Stroop word interference time (rs11514810, P=3.42E-09 for discovery, P=0.01176 for replication and combined P=5.249E-09). Regulatory feature analysis and expression quantitative trait loci (eQTL) data showed that this locus contributes to MICALL2 expression in the human brain. Most genes in the network interacting with MICALL2 were associated with psychiatric disorders. Furthermore, hyperactive-impulsive-like behavior was induced by reducing the expression of the zebrafish gene that is homologous to MICALL2, which could be rescued by tomoxetine (atomoxetine), a clinical medication for ADHD. Our results suggested that MICALL2 is a new susceptibility gene for executive inhibition deficiency related to hyperactive-impulsive behavior in ADHD, further emphasizing the possible role of neurodevelopmental genes in the pathogenic mechanism of ADHD.

[Analysis of the factors associated with the long-term curative effect and prognosis of primary vaginal carcinoma]

Objective: To investigate the clinical factors that affect the prognosis of patients with primary vaginal cancer. Methods: Clinical data of 118 primary vaginal cancer patients with pathological diagnosis and clinical follow-up data from the Department of Gynecology of Liaoning Cancer Hospital & Institute from 1999 to 2014 were collected and retrospectively analyzed. The relationship of prognosis and factors including age, history of hysterectomy, pathological types, International Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, tumor location and therapeutic methods were analyzed, respectively. Results: The median survival time of the 118 patients was 93 months. The survival rates of 1, 3, 5, 10 and 15-year were 89.7%, 68.1%, 60.4%, 37.3% and 19.0%, respectively.The results of univariate analysis showed that the FIGO stage, pathological types, tumor size, therapeutic methods and tumor location were related to the prognosis of patients with primary vaginal cancer (all P<0.05), while the patients' age, history of hysterectomy were not (all P>0.05). The results of Cox multivariate regression analysis indicated that FIGO stage (P=0.008), tumor location (P=0.001) and therapeutic methods (P=0.007) were independent prognostic factors of the patients with primary vaginal cancer. Conclusions: Prognostic factorsofpatients with primary vaginal cancer include FIGO stage, pathological types, tumor size, therapeutic methods and tumor location. Among them, therapeutic methods and tumor location are the independent prognostic factors.

Design, synthesis and biological activities of new brassinosteroid analogues with a phenyl group in the side chain

We have prepared and studied a series of new brassinosteroid derivatives with a p-substituted phenyl group in the side chain. To obtain the best comparison between molecular docking and biological activities both types of brassinosteroids were synthesized; 6-ketones, 10 examples, and B-lactones, 8 examples. The phenyl group was introduced into the steroid skeleton by Horner-Wadsworth-Emmons. The docking studies were carried out using AutoDock Vina 1.05. Plant biological activities were established using different brassinosteroid bioassays in comparison with natural brassinosteroids. Differences in the production of the plant hormone ethylene were also observed in etiolated pea seedlings after treatment with new brassinosteroids. The most active compounds were lactone 8f and 6-oxo derivatives 8c and 9c, their biological activities were comparable or even better than naturally occurring brassinolide. Finally the cytotoxicity of the new derivatives was studied using human normal and cancer cell lines.

Development of an empirical model to predict malaria outbreaks based on monthly case reports and climate variables in Hefei, China, 1990-2011

Malaria remains a significant public health concern in developing countries. Drivers of malaria transmission vary across different geographical regions. Climatic variables are major risk factor in seasonal and secular patterns of P. vivax malaria transmission along Anhui province. The study aims to forecast malaria outbreaks using empirical model developed in Hefei, China. Data on the monthly numbers of notified malaria cases and climatic factors were obtained for the period of January 1st 1990 to December 31st 2011 from the Hefei CDC and Anhui Institute of Meteorological Sciences, respectively. Two logistic regression models with time series seasonal decomposition were used to explore the impact of climatic and seasonal factors on malaria outbreaks. Sensitivity and specificity statistics were used for evaluating the predictive power. The results showed that relative humidity (OR = 1.171, 95% CI = 1.090-1.257), sunshine (OR = 1.076, 95% CI = 1.043-1.110) and barometric pressure (OR = 1.051, 95% CI = 1.003-1.100) were significantly associated with malaria outbreaks after adjustment for seasonality in Hefei area. The validation analyses indicated the overall agreement of 70.42% (sensitivity: 70.52%; specificity: 70.30%). The research suggested that the empirical model developed based on disease surveillance and climatic conditions may have applications in malaria control and prevention activities.

Identification of Functional Genetic Polymorphisms at IL-10 Promoter Region and their Association with Risk of Ischemic Stroke in Chinese Han Population

BACKGROUND

Pleiotropic cytokine interleukin-10 (IL-10) has been suggested as modifying risk for atherosclerosis. Promoter region genetic polymorphism of IL-10 gene is known to be associated with the level of IL-10 production. Through these effects, they might be involved with the ischemic stroke (IS). Our aim was to assess the nature of the functional polymorphisms in IL-10 promoter and any links with IS in Chinese Han population.

METHODS

The IL-10 -1082 G>A, -819 C>T and -592 C>A functional polymorphisms were determined by TaqMan SNP Genotyping assays in 1296 subjects (648 IS patients diagnosed by CTs or/and magnetic resonance imaging (MRI) and 648 normal healthy controls from Chinese Han Population). Multivariate logistic regression analysis was used to show the association between the IL-10 genotypes and the IS events.

RESULTS

We found that the CC genotype of -819 C>T was more common in controls than IS subjects (P<0.05, corrected for multiple testing) in the Han population. CC carriage may be associated with the decreased risk of IS in the Han ethnic group (OR 0.65, 95% CI 0.43-0.97). In addition, the CC genotype in -592 C>A and GG genotype in -1082 G>A are all extremely low in Chinese Han cases and controls.

CONCLUSIONS

The G allele frequency at the -1082 promoter region of IL-10 was rare in Chinese Han population which are diffierent from American/European populations.. IL-10 -819 C>T may be an independent protective factor for IS in the Chinese Han population.

Dietary vitamin C intake and the risk of hip fracture: a dose-response meta-analysis

The meta-analysis suggested that dietary vitamin C was statistically inversely associated with the risk of hip fracture (overall OR = 0.73, 95% CI = 0.55-0.97, I ² = 69.1%) and with the increase of 50 mg/day vitamin C intake, the risk of hip fracture will reduce by 5% (OR = 0.95, 95% CI 0.91-1.00, P = 0.05).

INTRODUCTION

Previous studies had inconsistent findings regarding the association between vitamin C intake and the risk of hip fracture. Therefore, we conducted a meta-analysis to evaluate the association of dietary vitamin C intake and the risk of hip fracture.

METHODS

Relevant studies were identified by searching PubMed, Embase, and Web of Science up to December 2016. Additional articles were identified from reviewing the reference lists of relevant articles. The summary relative risks (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by random effects model. Funnel plot and Egger's test were used to test publication bias.

RESULTS

The total six articles containing 7908 controls and 2899 cases of hip fracture were included in this meta-analysis. By comparing the highest versus the lowest categories of vitamin C intake, we found that dietary vitamin C was statistically correlated with the risk of hip fracture [overall OR = 0.73, 95% CI = 0.55-0.97, I ² = 69.1%]. A linear dose-response association showed that the increase with vitamin C intake of 50 mg/day statistically reduced by 5% (OR = 0.95, 95% CI 0.91-1.00, P = 0.05) the risk of hip fracture.

CONCLUSIONS

In conclusion, the results of current meta-analysis strongly support that increasing dietary vitamin C intake can decrease the risk of hip fracture. In order to verify the association of vitamin C intake and hip fracture risk, further well-designed largely randomized controlled trials (RCTs) are needed.

Transcatheter aortic valve replacement with balloon-expandable valve : Analysis of initial experience in China

Background

Transcatheter aortic valve replacement (TAVR) is widely applied for the treatment of severe aortic stenosis (AS) in developed countries; however, in China, it is still in the early stage of utilization. On the basis of previous studies, this work explored the feasibility of TAVR in patients with severe AS in China and analyzed the cause of death in four cases.

Methods

This retrospective study included 20 patients who had severe AS and underwent TAVR with a balloon-expandable system (Edwards SAPIEN XT) in our hospital from January 2011 to June 2016. The valve and heart functions of 16 survivors before and after the TAVR procedure were compared. TAVR endpoints, device success, and adverse events were assessed according to the definitions of the Valve Academic Research Consortium-2 (VARC-2).

Results

There were 13 male and seven female patients aged 65–81 years (average, 73.15) who underwent TAVR. The TAVR approach was transfemoral in 19 patients and transapical in one patient. Four patients died (two of coronary artery occlusion and two of aortic annulus rupture) during the TAVR procedure or shortly after; six patients had mild paravalvular leakage, and the rest of the patients showed a significant improvement in cardiac function. During the follow-up period (2–62 months), one patient died of lung cancer 13 months after the TAVR procedure.

Conclusion

TAVR with a balloon-expandable system is safe and effective and can be used for patients with severe AS in China. It requires careful patient selection and preoperative assessment so as to reduce the 30-day postoperative mortality rate.

Note: A highly symmetrical piezoelectric motor with self-matching friction and large output force

We present a new stacked TunaDrive motor with two intact piezoelectric stacks being spring-clamped by a pair of parallel highly polished zirconia ceramic rods. Compared with the earlier version we presented with five stacks, it has a simpler and more compact structure and is much easier to build. Although the usage of piezoelectric material is cut by ∼35%, the motor can still provide a large output force of ∼1.92 N, which is nearly the same as that of the earlier version. The simple and symmetrical structure, high rigidity, and large output force make the new motor an ideal tool for coarse approach with nanometer precision.

Correlation of quantitative parameters of magnetic resonance perfusion-weighted imaging with vascular endothelial growth factor, microvessel density and hypoxia-inducible factor-1α in nasopharyngeal carcinoma: Evaluation on radiosensitivity study

OBJECTIVES

To investigate the correlation of parameters of magnetic resonance perfusion-weighted imaging (MR-PWI) with the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α) and microvessel density (MVD) in nasopharyngeal carcinoma (NPC) so as to explore the value of predicting radiosensitivity.

DESIGN

A prospective study.

SETTING

Department of Head-and-neck radiotherapy in Hunan Cancer Hospital.

PARTICIPANTS

Ninety-four patients of NPC were included between December 2013 and December 2014.

MAIN OUTCOME MEASURES

The expression of VEGF, MVD and HIF-1α was studied by immunohistochemistry, and magnetic resonance perfusion-weighted imaging (MR-PWI) was performed before and after undergoing radiotherapy (20 Gy dose). Parameters of MR-PWI, volume of primary tumour and rate of tumour remission were measured and calculated. Patients with primary local tumour were then divided into completely response group (CR group) and partially response group (non-CR group) according to tumour regression condition. Relevant parameters were analysed by Spearman, and diagnostic efficiency of radiosensitivity was analysed by receiver operating characteristic curve (ROC).

RESULTS

The expression of VEGF was positively correlated with MVD (r = .322,P < .05), but the expression of HIF-1α was no significant correlations with VEGF and MVD. The expression VEGF was in positive correlation with fractional plasma volume (fpv) (r = .339, P = .05) before radiotherapy. There was a significant difference in the quantitative parameters of MR-PWI between CR group and non-CR group during the course of radiotherapy and at the end of radiotherapy treatment. The change of blood reflux constant (Δkep20) and extravascular extracellular space volume fraction (ΔVe20) before and after treatment was positively correlated with primary local tumour remission condition after 3 month treatment; Δkep and ΔVe were negatively correlated with primary local tumour remission condition after 3 months. Tumour regression rate was only positively correlated with Ve and the average volume of primary tumour after 2 week treatment (V1). ROC curve showed that R20 ≥ 65.69%, and was considered as a threshold to predict primary local tumour remission, with a sensitivity of 0.84 and specificity of 0.69, and area under the curve was 0.819 (P = .000).

CONCLUSIONS

The parameters of MR-PWI with the expression of VEGF, HIF-1α and MVD could be guidance for predicting radiosensitivity in NPC.

Impact of graft preservation solutions for liver transplantation on early cytokine release and postoperative organ dysfunctions. A pilot study

INTRODUCTION

During liver transplantation, graft ischemia-reperfusion injury leads to a systemic inflammatory response producing postoperative organ dysfunctions. The aim of this observational and prospective study was to compare the impact of Solution de conservation des organes et tissus (SCOT) 15 and University of Wisconsin (UW) preservation solutions on early cytokine release, postreperfusion syndrome and postoperative organ dysfunctions.

METHODS

Thirty-seven liver transplantations were included: 21 in UW Group and 16 in SCOT 15 group. Five cytokines were measured in systemic blood after anesthetic induction, 30minutes after unclamping portal vein and on postoperative day 1.

RESULTS

Following unclamping portal vein, cytokines were released in systemic circulation. Systemic cytokine concentrations were higher in UW than in SCOT 15 group: Interleukin-10, Interleukine-6. In SCOT 15 group, significant reduction of postreperfusion syndrome incidence and acute kidney injury were observed. Alanine and aspartate aminotransferase peak concentrations were higher in SCOT 15 group than in UW group. However, from postoperative day 1 to day 10, aminotransferase returned to normal values and did not differ between groups.

CONCLUSIONS

Compared to UW, SCOT 15 decreases systemic cytokine release resulting from graft ischemia-reperfusion injury and reduces incidence of postreperfusion syndrome and postoperative renal failure.

Miscellanea Dependent generalized functional linear models

This paper considers testing for no effect of functional covariates on response variables in multivariate regression. We use generalized estimating equations to determine the underlying parameters and establish their joint asymptotic normality. This is then used to test the significance of the effect of predictors on the vector of response variables. Simulations demonstrate the importance of considering existing correlation structures in the data. To explore the effect of treating genetic data as a function, we perform a simulation study using gene sequencing data and find that the performance of our test is comparable to that of another popular method used in sequencing studies. We present simulations to explore the behaviour of our test under varying sample size, cluster size and dimension of the parameter to be estimated, and an application where we are able to confirm known associations between nicotine dependence and neuronal nicotinic acetylcholine receptor subunit genes.

[The combined effects of family history of cardiovascular disease and overweight on ischemic stroke incidence among the Mongolian population]

Objective: To investigate the cumulative effect of family history of cardiovascular disease(CVD)and overweight on ischemic stroke events in the Mongolian population. Methods: Study participants were recruited from 32 villages from May 2002 to August 2012 in Kezuohou Banner(county)and Naiman Banner in Inner Mongolia, China. Among 3 457 Mongolian people aged ≥20 years old living in these villages, 2 589 were selected to participate in this study. None of the participants had chronic kidney disease, malignant tumor, thyroid disease or adrenalopathy, or acute infectious disease. The 2 589 participants were followed for a mean of 9.2 years. Six participants were lost to follow up, resulting in a follow-up rate of 99.8%. Information collected included demographic characteristics, lifestyle risk factors, alcohol consumption, cigarette smoking, history of disease, family history of CVD, and physical examination. Ischemic stroke incidence information was collected during follow-up. All participants were categorized into four subgroups according to family history of CVD and overweight status. Cox proportional hazards models were used to estimate the hazard ratios(HR)and 95% CI of ischemic stroke events among subgroups, compared with the subgroup with no family history of CVD and body mass index(BMI)<24 kg/m²(the reference group). Results: Among 2 589 participants, 76 ischemic stroke events occurred after follow-up, and 8 were excluded because of lack of key data. Finally, 2 581 participants were included in the analysis, and the incidence density was 323/100 000 person-years. The cumulative incidence rates of ischemic stroke were 2.48%, 1.86%, 6.67% and 9.00% in the no family history of CVD and BMI <24 kg/m², no family history of CVD and BMI ≥24 kg/m², family history of CVD and BMI <24 kg/m² and family history of CVD and BMI ≥ 24 kg/m² subgroups, respectively. Using the Cox proportional hazards model, after further adjustment for age, gender, smoking, drinking, FPG, hypertension, total cholesterol, triglycerides, and heart rate, the risk of ischemic stroke in the subgroup with a family history of CVD and BMI ≥24 kg/m² was higher than the reference group(HR: 2.61, 95% CI: 1.16-5.87). However, the risk of ischemic stroke in other two groups was not statistically significant compared with the reference group. The HR(95% CI)values in the no family history of CVD and BMI ≥24 kg/m²and family history of CVD and BMI <24 kg/m² subgroups were 1.18(0.5- 2.39)and 1.27(0.67- 2.42), respectively. Conclusion: In the Mongolian population, a family history of CVD and coexistent overweight may increase the risk of ischemic stroke events, suggesting that in people with family history of cardiovascular disease, weight control is conducive to the prevention of ischemic stroke.

Simulation of ECM with Silk and Chitosan Nanocomposite Materials

Extracellular matrix (ECM) is a system used to model the design of biomaterial matrices for tissue regeneration. Various biomaterial systems have been developed to mimic the composition or microstructure of the ECM. However, emulating multiple facets of the ECM in these systems remains a challenge. Here, a new strategy is reported which addresses this need by using silk fibroin and chitosan (CS) nanocomposite materials. Silk fibroin was first assembled into ECM-mimetic nanofibers in water and then blended with CS to introduce the nanostructural cues. Then the ratios of silk fibroin and CS were optimized to imitate the protein and glycosaminoglycan compositions. These biomaterial scaffolds had suitable compositions, hierarchical nano-to-micro structures, and appropriate mechanical properties to promote cell proliferation in vitro, and vascularization and tissue regeneration in vivo. Compared to previous silk-based scaffolds, these scaffolds achieved improvements in biocompatibility, suggesting promising applications in the future in tissue regeneration.

Hypertrophic cardiomyopathy and left ventricular hypertrophy in hypertensive heart disease with mildly reduced or preserved ejection fraction: insight from altered mechanics and native T1 mapping

AIM

To explore the relationship between extracellular volume (ECV), native T1, and systolic strain in hypertrophic cardiomyopathy (HCM) and hypertensive patients with left ventricular hypertrophy (HTN LVH) with mildly reduced or preserved ejection fraction.

MATERIALS AND METHODS

T1 mapping was performed in 45 patients with late gadolinium enhancement positive (LGE+) HCM (mean age, 53±6 years), 11 patients with LGE- (LGE-) HCM (mean age, 56±5 years), and 20 patients with HTN LVH (mean age, 55±6 years) on at 3 T magnetic resonance imaging (MRI) using the modified look-locker inversion-recovery (MOLLI) pulse sequence. Mean T1 value, ECV and circumferential strain parameters were determined for each patient.

RESULTS

Overall, the HCM patients had higher native T1 values (1242.92±68.94) and ECV (0.31±0.05) in comparison to those of the HTN LVH patients (1197±46.80, 0.27±0.04; p<0.05). In the subgroup analysis, the HCM LGE+ patients had the highest native T1 values among the three groups. The HCM LGE+ patients had higher ECV than the LGE- patients. HCM LGE- patients had higher ECV than HTN LVH patients (p<0.05). Peak systolic circumferential strain and early diastolic strain rates were reduced in the HCM LGE+ patients in comparison to the HCM LGE- and HTN LVH patients (p<0.05). Reduced peak systolic and early diastolic circumferential strain rates were associated with increased levels of ECV and native T1 values among all the patients.

CONCLUSION

HCM LGE+ patients had higher native T1 values, higher ECV, and an associated reduction in early diastolic strain rates and peak systolic circumferential strains when compared to the HCM LGE- and HTN LVH patients with mildly reduced or preserved ejection fraction.

[Impacts of early metoprolol intervention on connexin 43 and phosphorylated connexin 43 expression in rabbits with experimental myocardial infarction]

Objective: To investigate the early intervention effects of metoprolol on connexin 43(Cx43) and phosphorylated Cx43 (p-Cx43) expression in rabbits with post myocardial infarction. Methods: A total of 24 adult male New Zealand white rabbits were divided into sham group (n=6), early treatment group(n=6), routine treatment group(n=6), and myocardial infarction group(n=6) with a randomized block design blocked by weight. Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation. Rabbits in sham group received similar surgical procedure without LAD ligation. Metoprolol (12.5 mg/kg dissolved in 2 ml distilled water) was applied to rabbits in early treatment group and routine treatment group per gavage immediately after recovery from anesthesia and at 24 hours after myocardial infarction, respectively, then treated daily for 40 days. Rabbits in sham group and myocardial infarction group received 2 ml distilled water per gavage daily for 40 days. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) level were detected by automatic biochemistry analyzer after 6 hours in all rabbits. Ventricular fibrillation threshold (VFT) was measured in vivo by bipolar pacing electrodes at 40 days. Cx43 and p-Cx43 distribution in ventricular tissue was detected by immunofluorescence analyses. Cx43 and p-Cx43 protein level in ventricular tissue was determined by Western blot. Results: (1) Plasma LDH ((851.7±85.9)U/L vs. (332.3±39.6)U/L, P<0.01) and CK ((1 192.7±105.3)U/L vs. (462.3±65.6)U/L, P<0.01) were significantly higher in myocardial infarction group than in sham group (both P<0.01). (2) VFT was significantly lower in myocardial infarction group than that in sham group ((470.0±91.0) beats per minute vs. (683.3±60.9) beats per minute, P<0.05), and VFT was significantly higher in early treatment group ((633.3±43.2) beats per minute) and routine treatment group ((645.0±30.8) beats per minute) than in the myocardial infarction group (both P<0.05). (3) Immunofluorescence analyses showed that Cx43 was mainly localized in the intercalated disk, which was perpendicular to the cell long axis with linear arrangement, and less lateral distribution in sham group, early treatment group and routine treatment group, which was significantly different as the case in the myocardial infarction group. The expression of p-Cx43 in myocardial infarction group was less than in sham group, which was significantly upregulated in in early treatment group and routine treatment group when compared with myocardial infarction group, and expression of p-Cx43 was significantly higher in early treatment group than in routine treatment group. (4)The p-Cx43/Cx43 ratio of protein was significantly lower in myocardial infarction group than in sham group (0.165±0.011 vs. 0.363±0.046, P<0.05), and significantly higher in early treatment group (0.720±0.063) and routine treatment group (0.364±0.030) than in myocardial infarction group (both P<0.05), and this ratio was significantly higher in early treatment group than in routine treatment group (P<0.05). Conclusion: Metoprolol treatment, especially the early metoprolol treatment (within 24 hours after LAD ligation), could significantly improve VFT by ameliorating the distribution and dephosphorylation of myocardial Cx43 in rabbits with experimental myocardial infarction.

Modelling metaldehyde in catchments: a River Thames case-study

The application of metaldehyde to agricultural catchment areas to control slugs and snails has caused severe problems for drinking water supply in recent years. In the River Thames catchment, metaldehyde has been detected at levels well above the EU and UK drinking water standards of 0.1 μg l^-1 at many sites across the catchment between 2008 and 2015. Metaldehyde is applied in autumn and winter, leading to its increased concentrations in surface waters. It is shown that a process-based hydro-biogeochemical transport model (INCA-contaminants) can be used to simulate metaldehyde transport in catchments from areas of application to the aquatic environment. Simulations indicate that high concentrations in the river system are a direct consequence of excessive application rates. A simple application control strategy for metaldehyde in the Thames catchment based on model results is presented.

Simultaneous esophagectomy and off-pump coronary artery bypass grafting: a practicable approach with good survival

Surgery continues to be the mainstay of esophageal cancer treatment. However, it is a big challenge for the surgical treatment of patients with both esophageal cancer and coronary artery disease (CAD). We reported, here, the first case series of esophageal cancer patients treated with simultaneous esophagectomy and off-pump coronary artery bypass grafting (CABG). From August 2010 to August 2012, 2154 esophageal or esophageal gastric junction (EGJ) cancer patients underwent surgical treatment in Tangdu Hospital, Xi'an, China. Among them, six patients with esophageal or EGJ esophageal gastric junction cancer complicated with CAD were given simultaneous esophagectomy and off-pump CABG, and were followed up until August 2014. Four patients were operated through left lateral thoracotomy and two patients were operated through median sternotomy plus upper midline laparotomy. All the patients survived the operation well and the postoperative morbidity rate was 67% (one anastomosis leakage, three cardiac arrhythmias). There was no postoperative mortality. The mean follow-up time was 34.5 ± 7.8 months (range, 24-46 months). One patient died 36 months later due to tumor recurrence and all the other patients survived until the time to follow up. Simultaneous esophagectomy and off-pump CABG approach might be a safe and effective procedure with good survival in selected patients with both esophageal cancer and CAD.

Fate and transport of polychlorinated biphenyls (PCBs) in the River Thames catchment - Insights from a coupled multimedia fate and hydrobiogeochemical transport model

The fate of persistent organic pollutants (POPs) in riverine environments is strongly influenced by hydrology (including flooding) and fluxes of sediments and organic carbon. Coupling multimedia fate models (MMFMs) and hydrobiogeochemical transport models offers unique opportunities for understanding the environmental behaviour of POPs. While MMFMs are widely used for simulating the fate and transport of legacy and emerging pollutants, they use greatly simplified representations of climate, hydrology and biogeochemical processes. Using additional information about weather, river flows and water chemistry in hydrobiogeochemical transport models can lead to new insights about POP behaviour in rivers. As most riverine POPs are associated with suspended sediments (SS) or dissolved organic carbon (DOC), coupled models simulating SS and DOC can provide additional insights about POPs behaviour. Coupled simulations of river flow, DOC, SS and POP dynamics offer the possibility of improved predictions of contaminant fate and fluxes by leveraging the additional information in routine water quality time series. Here, we present an application of a daily time step dynamic coupled multimedia fate and hydrobiogeochemical transport model (The Integrated Catchment (INCA) Contaminants model) to simulate the behaviour of selected PCB congeners in the River Thames (UK). This is a follow-up to an earlier study where a Level III fugacity model was used to simulate PCB behaviour in the Thames. While coupled models are more complex to apply, we show that they can lead to much better representation of POPs dynamics. The present study shows the importance of accurate sediment and organic carbon simulations to successfully predict riverine PCB transport. Furthermore, it demonstrates the important impact of short-term weather variation on PCB movement through the environment. Specifically, it shows the consequences of the severe flooding, which occurred in early 2014 on sediment PCB concentrations in the River Thames.

New Insights Into Cellular Stress Responses to Environmental Metal Toxicants

Exposures to metal toxicants in the environment disrupt normal physiological functions and have been linked to the development of a myriad of human diseases. While the molecular and cellular mechanisms underlying metal toxicities remain to be fully understood, it is well appreciated that metal toxicants induce cellular stresses and that how cells respond to the stresses plays an important role in metal toxicity. In this review, we focus on how metal exposures induce stresses in the endoplasmic reticulum (ER) to elicit the unfolded protein response (UPR). We document the emerging evidence that induction of ER stress and UPR in the development of human diseases is associated with metal exposures. We also discuss the role of the interplay between ER stress and oxidative stress in metal toxicity. Finally, we review recent advances in functional genomics approaches and discuss how applications of these new tools could help elucidate the molecular mechanisms underlying cellular stresses induced by environmental metal toxicants.

Modeling Alkaline Phosphatase Inactivation in Bovine Milk During High-Temperature Short-Time Pasteurization

Alkaline phosphatase (AP) is used as the indicator enzyme for proper pasteurization of bovine milk. Predictive modeling of AP inactivation during high-temperature short-time (HTST) pasteurization would support regulations; thus ensuring the safety of heat treated milk. Activation energy (Ea) of AP in milk was measured experimentally using the capillary tube method, and Ea was found to be 429252 J/mol. The Ea was used to develop a nonlinear model to describe the thermal inactivation of milk in a small-scale HTST pasteurizer with a plate heat exchanger. Integrated pasteurization effect (PE) was obtained at different holding temperatures (62–72°C) and holding times (3–25 s), by converting times at different temperatures in various sections of the pasteurizer to the equivalent time at the reference temperature (72°C). A nonlinear function was developed to relate the log(% residual AP activity) to PE. The r2 varied from 0.7488 to 0.8311. The validation trial indicated that the model could predict AP activity accurately for the% residual AP activity >1%.

AAV-mediated transduction and targeting of retinal bipolar cells with improved mGluR6 promoters in rodents and primates

Adeno-associated virus (AAV) vectors have been a powerful gene delivery vehicle to the retina for basic research and gene therapy. For many of these applications, achieving cell type-specific targeting and high transduction efficiency is desired. Recently, there has been increasing interest in AAV-mediated gene targeting to specific retinal bipolar cell types. A 200-bp enhancer in combination with a basal SV40 promoter has been commonly used to target transgenes into ON-type bipolar cells. In the current study, we searched for additional cis-regulatory elements in the mGluR6 gene for improving AAV-mediated transduction efficiency into retinal bipolar cells. Our results showed that the combination of the endogenous mGluR6 promoter with additional enhancers in the introns of the mGluR6 gene markedly enhanced AAV transduction efficiency as well as made the targeting more selective for rod bipolar cells in mice. Furthermore, the AAV vectors with the improved promoter could target to ON bipolar cells with robust transduction efficiency in the parafovea and the far peripheral retina of marmoset monkeys. The improved mGluR6 promoter constructs could provide a valuable tool for genetic manipulation in rod bipolar cells in mice and facilitate clinical applications for ON bipolar cell-based gene therapies.

[Application of Postmortem Biochemistry in Forensic Diagnosis of Diabetic Ketoacidosis]

Diabetic ketoacidosis is a serious complication results from the high blood levels of glucose and ketone in diabetes mellitus patients that cause metabolic overbalance. An analysis of postmortem biochemical indexes is needed in such cases without specific signs of the routine forensic medicine examination. Postmortem biochemistry is a kind of examinations that collecting the body fluids of the corpses to determine the metabolic state of their life time to estimate the cause of death. This paper reviews the basic features and signs of the forensic medicine examination in the dead cases of diabetic ketoacidosis, and emphatically analyzes the postmortem biochemical indexes of diabetic ketoacidosis, and summarizes new ideas of forensic medicine diagnosis in diabetic ketoacidosis death.

Epigenetically mediated spontaneous reduction of NFAT1 expression causes imbalanced metabolic activities of articular chondrocytes in aged mice

OBJECTIVE

Abnormal metabolic activities of chondrocytes may cause articular cartilage (AC) degradation, but key transcription factors regulating metabolic activities in AC of aging individuals remain unknown. This study aimed to investigate the role of transcription factor NFAT1 in regulating the expression of anabolic and catabolic molecules in AC of aged mice.

METHODS

The hip, knee, and shoulder joints of BALB/c mice were harvested at 6, 12, 15, 18, and 24 months of age for histopathological and immunohistochemical (IHC) analyses. Total RNA was isolated from AC for gene expression. Genomic DNA and chromatin were prepared from AC for methylated DNA immunoprecipitation (MeDIP) and chromatin immunoprecipitation (ChIP) assays.

RESULTS

NFAT1 expression in AC of mice was significantly decreased after 12 months of age, which was associated with reduced proteoglycan staining, decreased expression of chondrocyte markers, and increased expression of interleukin-1β. Forced Nfat1 expression in chondrocytes from aged mice significantly reversed the abnormal metabolic activities. ChIP assays confirmed that NFAT1 bound to the promoter of the Acan, Col2a1, Col9a1, Col11a1, Il1b, Mmp13 and Tnfa genes in articular chondrocytes of aged mice. ChIP and MeDIP assays revealed that reduced NFAT1 expression in AC of aged mice was regulated by epigenetic histone methylation at the promoter region and was correlated with increased DNA methylation at introns 1 and 10 of the Nfat1 gene.

CONCLUSION

NFAT1 is a transcriptional regulator of multiple anabolic and catabolic genes in AC of aged mice. Epigenetically mediated reduction of NFAT1 expression causes imbalanced metabolic activities of articular chondrocytes in aged mice.

High frequency of mitochondrial DNA mutations in HIV-infected treatment-experienced individuals

OBJECTIVES

We recently observed a decrease in deoxyribonucleotide (dNTP) pools in HIV-infected individuals on antiretroviral therapy (ART). Alterations in dNTPs result in mutations in mitochondrial DNA (mtDNA) in cell culture and animal models. Therefore, we investigated whether ART is associated with mitochondrial genome sequence variation in peripheral blood mononuclear cells (PBMCs) of HIV-infected treatment-experienced individuals.

METHODS

In this substudy of a case-control study, 71 participants were included: 22 'cases', who were HIV-infected treatment-experienced patients with mitochondrial toxicity, 25 HIV-infected treatment-experienced patients without mitochondrial toxicity, and 24 HIV-uninfected controls. Total DNA was extracted from PBMCs and purified polymerase chain reaction (PCR) products were subjected to third-generation sequencing using the PacBio Single Molecule Real-Time (SMRT) sequencing technology. The sequences were aligned against the revised Cambridge reference sequence for human mitochondrial DNA (NC_012920.1) for detection of variants.

RESULTS

We identified a total of 123 novel variants, 39 of them in the coding region. HIV-infected treatment-experienced patients with and without toxicity had significantly higher average numbers of mitochondrial variants per participant than HIV-uninfected controls. We observed a higher burden of mtDNA large-scale deletions in HIV-infected treatment-experienced patients with toxicity compared with HIV-uninfected controls (P = 0.02). The frequency of mtDNA molecules containing a common deletion (mt.δ4977) was higher in HIV-infected treatment-experienced patients with toxicity compared with HIV-uninfected controls (P = 0.06). There was no statistically significant difference in mtDNA variants between HIV-infected treatment-experienced patients with and without toxicity.

CONCLUSIONS

The frequency of mtDNA variants (mutations and large-scale deletions) was higher in HIV-infected treatment-experienced patients with or without ART-induced toxicity than in uninfected controls.

Bioactive Natural Protein-Hydroxyapatite Nanocarriers for Optimizing Osteogenic Differentiation of Mesenchymal Stem Cells

Improving the controlled release of bioactive growth factors to regulate cell behavior and tissue regeneration remains a need in tissue engineering and regenerative medicine. Inorganic and polymeric nanoparticles have been extensively fabricated as bioactive biomaterials with enhanced biocompatibility and effective carriers of therapeutic agents, however, challenges remain such as the achievement of high loading capacity and sustained release, and the bioactivity preservation of growth factors. Here, a multilayered, silk coated hydroxyapatite (HA) nanocarrier with drug loading-release capacity superior to pure silk or HA nanoparticles was developed. Bone morphogenetic protein-2 (BMP-2) was bound to the silk coatings with a high binding efficiency of 99.6%, significantly higher than that in silk or the HA nanoparticles alone. The release of BMP-2 was sustained in vitro over a period of 21 days without burst release. Compared with BMP-2 loaded silk or HA particles, bone mesenchymal stem cells (BMSCs) showed improved proliferation and osteogenesis when cultured with the BMP-2 loaded composite nanocarriers. Therefore, these silk-HA composite nanoparticles present a useful approach to designing bioactive nanocarrier systems with enhanced functions for bone tissue regeneration needs.

Patterns of Growth and Decline in Lung Function in Persistent Childhood Asthma

BACKGROUND

Tracking longitudinal measurements of growth and decline in lung function in patients with persistent childhood asthma may reveal links between asthma and subsequent chronic airflow obstruction.

METHODS

We classified children with asthma according to four characteristic patterns of lung-function growth and decline on the basis of graphs showing forced expiratory volume in 1 second (FEV1), representing spirometric measurements performed from childhood into adulthood. Risk factors associated with abnormal patterns were also examined. To define normal values, we used FEV1 values from participants in the National Health and Nutrition Examination Survey who did not have asthma.

RESULTS

Of the 684 study participants, 170 (25%) had a normal pattern of lung-function growth without early decline, and 514 (75%) had abnormal patterns: 176 (26%) had reduced growth and an early decline, 160 (23%) had reduced growth only, and 178 (26%) had normal growth and an early decline. Lower baseline values for FEV1, smaller bronchodilator response, airway hyperresponsiveness at baseline, and male sex were associated with reduced growth (P<0.001 for all comparisons). At the last spirometric measurement (mean [±SD] age, 26.0±1.8 years), 73 participants (11%) met Global Initiative for Chronic Obstructive Lung Disease spirometric criteria for lung-function impairment that was consistent with chronic obstructive pulmonary disease (COPD); these participants were more likely to have a reduced pattern of growth than a normal pattern (18% vs. 3%, P<0.001).

CONCLUSIONS

Childhood impairment of lung function and male sex were the most significant predictors of abnormal longitudinal patterns of lung-function growth and decline. Children with persistent asthma and reduced growth of lung function are at increased risk for fixed airflow obstruction and possibly COPD in early adulthood. (Funded by the Parker B. Francis Foundation and others; ClinicalTrials.gov number, NCT00000575.).

First Measurement of Electron Neutrino Appearance in NOvA

We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

[Cortical auditory evoked potentials in congenital hearing impaired children with cochlear implants]

OBJECTIVE

By investigating the auditory cortical evoked potential in congenital hearing impaired children with cochlear implants, the association between central auditory development and the age of implantation was studied.

METHODS

P1-N1-P2 were recorded in 110 profound hearing impaired children, aged from 12 to 80 months old and being implanted with cochlear implants before the age of 5 years. Their implant using time ranged from just at the switch-on to 48 months. The stimuli were /m/, /t/, /g/, presented at 65 dB SPL in sound field. The presence rate of each wave was obtained and the relationship between P1 latency and implant age, the time of speech processor switch-on were analyzed.

RESULTS

The presence rate of P1, N1 and P2 was 66.4%, 15.5% and 12.7%, respectively. The presence of P1 was significantly higher than that of N1(χ(2)=228.542, P=0.00)and P2(χ(2)=257.438, P=0.00). There was no significant difference of P1 presence rate elicited by /m/, /t/ and /g/(64.1%, 66.9% and 68.3%, χ(2)=0.589, P=0.75). There existed no significant difference either among P1 latency(P=0.22)or amplitude(P=0.09) elicited by /m/, /t/ and /g/. There was significant difference between the implant age before and after 42-month-old regarding the proportion that entered the age-appropriate normal P1 latency range(P=0.02). No significant difference was found among groups of implant using time of 1, 2, 3 and 4 years in aspect of the proportion that entered the age-appropriate normal P1 latency range(P=1.00).

CONCLUSIONS

Compared with implanted after the age of 42-month-old children with prelingual hearing impairment younger than 5 years old, the ones implanted before 42-month-old have more chance for normal development for central auditory system. Once implanted before 42-month-old, the cortical auditory system restored its normal development as early as 1 year after implantation.