Bio-orthogonal chemistry-based method for fluorescent labelling of ribosomal RNA in live mammalian cells

A bio-orthogonal chemistry-based approach for fluorescent labelling of ribosomal RNA is described.

Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay

We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse β decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the inverted hierarchy.

[Correlation between fetal borderline ventriculomegaly and chromosomal abnormalities]

Objective: To assess the association between fetal borderline ventriculomegaly (VM) diagnosed by prenatal ultrasound and chromosomal abnormality. Methods: Sonographic manifestation and chromosome of 129 cases with borderline VM diagnosed by prenatal sonography were analyzed retrospectively. All subjects were divided into 3 groups, 80 cases (62.0%, 80/129) in isolated VM (IVM) group, 27 cases (20.9%, 27/129) of VM with no additional structural abnormality group (including ultrasonic soft marker, abnormal volume of amniotic fluid and fetal growth restriction) and 22 cases (17.1%, 22/129) of VM with structural abnormality. Furthermore, the IVM group was sub-grouped according to fetal sex, lesion position and degree of expansion. The results of chromosome detection in different sub-group were analyzed statistically. Results: (1) Overall situation: in 129 enrolled cases of borderline VM, 8 cases of chromosomal abnormality were detected by CMA and the positive detection rate was 6.2% (8/129) , of which 2 cases were abnormal karyotype and 6 cases were pathologic copy number variation (p-CNV) . (2) The results of fetal chromosomal abnormalities detected in 3 groups: there were no case of abnormal karyotype and 4 cases of p-CNV in IVM group, the detection rate of chromosome abnormalities was 5.0% (4/80) . One case of abnormal karyotype and 2 cases of p-CNV in VM with no additional structural abnormality group, the detection rate was 11.1% (3/27) . One case of abnormal karyotype and no case of p-CNV in VM with structural abnormality group, the detection rate was 4.5% (1/22) . There were no significant difference among 3 groups (all P>0.05) . Conclusions: The risk of chromosomal abnormaliy increases in fetus with borderline VM. When the fetal VM is found by ultrasound, it is necessary to perform comprehensive scanning and regular follow-up. Fetal chromosomes examination is recommended.

[Analysis of copy number variation by CMA in fetus with increased nuchal translucency]

Objective: To investigated the clinical value of chromosomal microarray analysis (CMA) in fetuses with increased nuchal translucency (NT) . Methods: Totally 101 cases out of 19 261 singleton fetuses who underwent the first trimester (11-13⁺⁶ weeks) ultrasound examination from January 2015 to June 2017 at First Affiliated Hospital of Sun Yat-sen University were diagnosed with NT ≥2.5 mm and underwent invasive prenatal test for fetal karyotype and CMA. According to the combination of other ultrasound abnormalities, the cases were divided into isolated group (67.3%, 68/101) and complicated group (32.7%, 33/101) . In addition, the cases were divided into 5 groups according to the thickness of NT, 2.5-2.9 mm (borderline thickening; 16.8%, 17/101) , 3.0-3.4 mm (33.7%, 34/101) , 3.5-4.4 mm (16.8%, 17/101) , 4.5-5.4 mm (15.8%, 16/101) , and ≥5.5 mm (16.8%, 17/101) . Chi square test was used to detect the different rates of other combined ultrasound abnormalities and abnormal chromosome between 5 groups. Results: The median thickness of NT was 3.4 mm (2.5-8.5 mm) . And 32 cases (31.7%, 32/101) had abnormal karyotype. There was a significant difference in the frequency of abnormal karyotype between the isolated and the complicated group (20.6% vs 54.5%, P<0.01) . Among 69 cases (68.3%, 69/101) of normal karyotype, 3 cases (4.3%, 3/69) were detected with pathogenic copy number variation (CNV) by CMA. Thirty-five cases with chromosomal abnormalities (include abnormal karyotype and pathogenic CNV) , there was a significant difference in the frequency of chromosomal abnormalities between the isolated and the complicated group (23.5% vs 57.6%, P=0.001) . The median age of pregnant women in 5 groups was 35 years (24-39 years) , 33 years (23-46 years) , 31 years (21-46 years) , 33 years (21-41 years) and 35 years (21-43 years) . The rates of chromosomal abnormalities increased with the increase of NT thickness. There was significant difference in the incidence of associated chromosomal abnormalities among 5 groups (P<0.05) . Comparative analysis within the 5 groups, the incidence of associated chromosomal abnormalities between NT 2.5-2.9 mm and ≥5.5 mm was significantly different (P=0.005) , while the differences between the other groups were not significant (P>0.05) . Conclusions: There is a high risk of fetal chromosomal abnormalities in borderline NT thickening (2.5-2.9 mm) at advanced maternal age, but the pathogenic CNV is not detected. Chromosomal microdeletion or microduplication could be further detected in the NT thickening (≥3.0 mm) fetuses with normal karyotype by chromosome microarray analysis, while the positive rate is relatively low, and the variants of unknown significance might be detected.

Increased CD4+CD25-Foxp3+ T cells in Chinese systemic lupus erythematosus: correlate with disease activity and organ involvement

Objective

The increment of CD4+CD25−Foxp3+T cells has been reported in systemic lupus erythematosus (SLE) patients. However, the exact identity of this T cell subset is still unclear. Thus, we analyzed CD4+CD25−Foxp3+T cells and Treg cells (CD4+CD25+Foxp3+ T cells) in a large sample of Chinese SLE patients in different disease states.

Methods

A total of 280 SLE patients and 38 healthy volunteers were enrolled, which included 21 patients with untreated new-onset lupus (UNOL), 13 patients with drug withdrawal more than 6 months and 246 patients with treatments. Phenotypic and functional analysis of peripheral blood CD4+CD25−Foxp3+ T cells and Treg cells were performed by flow cytometry. The correlation of CD4+CD25−Foxp3+T cells and Treg cells with disease activity, clinical indicators and organ involvement were analyzed.

Results

CD4+CD25−Foxp3+ T cells and Treg cells were significantly increased in SLE patients and showed significantly positive correlations with disease activity. CD4+CD25−Foxp3+ T cells were significantly increased in patients with skin and hematologic involvement as well as arthritis. Diverse changes between CD4+CD25−Foxp3+ T cells and Treg cells when faced with different medications, especially HCQ and MMF. CD4+CD25−Foxp3+ T cells expressed more IFN-γ and less CTLA-4 than CD4+CD25+Foxp3+ T cells, which were similar to CD4+CD25+Foxp3− T cells, and expressed similar IL-17, ICOS and Helios to CD4+CD25+Foxp3+ T cells. The synthesis capacity of IL-10 of CD4+CD25−Foxp3+ T cells and the expression of GITR on CD4+CD25−Foxp3+ T cells were between CD4+CD25+Foxp3+ and CD4+CD25+Foxp3− T cells.

Conclusions

Our results indicate that increased CD4+CD25−Foxp3+ T cells in lupus patients, which combined the features of suppression and pro-inflammatory, may serve as a biomarker for disease activity and organ involvement in SLE.

Cohort Profile: The Chongqing Cancer Cohort Study (CCCS) of the Urban Population in Southwest China

Purpose: Urbanization is causing an increasingly negative effect on public health in China. This study was established to examine the associations between socio-economic and environmental exposures and the potential impact of gene-environment interactions and cancer risk of urban population in Chongqing, China. Participants: The cohort was established in Beibei District of Chongqing in southwest China. Between March 2016 and December 2016, we enrolled 57,332 adults who were 40-69 years of age, and collected baseline data on demographic information, socio-economic status, lifestyle, family and personal disease histories through face-to-face interviews using a standardized questionnaire. Regular follow-up including face-to-face interviews will take place every 5 years. Findings to date: Ninety-nine percent (56658/57332) of the participants completed the baseline assessment. The eligible participants had a mean age of 54.8 years, and 51.42% were females. Nearly three-fifths of participants having a normal BMI (18.5 to 23.9 kg/m2) and one-third being overweight (24.0 to 27.9 kg/m2). Among males, 29.58% were smokers and 21.08% were alcohol users. Among females, 1.49% were smokers and 1.66% were alcohol users. Among all participants, 7.03% of males and 9.08% of females reported their family history of cancer. Future plans: The relationships of modifiable risk factors with the cancer risk will be analyzed. Meanwhile, participants will be closely tracked to minimize loss to follow-up. We plan to construct a risk prediction model on cancer and verify the prediction model by genome-wide association studies (GWAS). The successful completion of this cohort study will allow for better targeting of cancer screening to those at highest risk in urban population of China and provide clinicians and policymakers with a practical predication rule.

Spectral Evidence for Emergent Order in Ba_{1-x}Na_{x}Fe_{2}As_{2}

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

Impact of UVA pre-radiation on UVC disinfection performance: Inactivation, repair and mechanism study

Ultraviolet (UV) light emission diode (LED), which is mercury free and theoretically more energy efficient, has now become an alternative to conventional UV lamps in water disinfection industry. In this research, the disinfection performance of a novel sequential process, UVA_365nm LED followed by UVC_265nm LED (UVA-UVC), was evaluated. The results revealed that the responses of different bacterial strains to UVA-UVC varied. Coupled with appropriate dosages of UVC, a 20 min UVA pre-radiation provided higher inactivations (log inactivation) of E. coli ATCC 11229, 15597 and 700891 by 1.2, 1.4 and 1.2 times, respectively than the sum of inactivations by UVA alone and UVC alone. On the contrary, the inactivation of E. coli ATCC 25922, the most UVC sensitive strain, decreased from 3 log to 1.8 log after UVA pre-radiation. A 30 min UVA pre-radiation did not affect the photo repair capacity of the four strains (n = 23, p > 0.1), but their dark repair ability was significantly inhibited (n = 14, p < 0.05). Mechanism study was conducted for two representative strains, E. coli ATCC 15597 and 25922 to understand the observed effect. The hypothesis that UVA pre-radiation promoted the yield of reactive oxygen species (ROS) was rejected. ELISA results indicated that 18% more cyclobutane pyrimidine dimers (CPD) were formed in E. coli ATCC 15597 with UVA pre-radiation (n = 3, p < 0.01), however, the CPD levels of E. coli ATCC 25922 was the same with or without UVA pre-radiation (n = 3, p > 0.01). Considering the results of both dark repair and CPD formation, it was concluded that the increased UV sensitivity of E. coli 15597 was originated from the increased CPD. For E. coli ATCC 25922, the enhanced UV resistance was attributed to the strain's adoption of a survival strategy, translesion DNA synthesis (TLS), when triggered by UVA pre-radiation. The study on UmuD protein, which is a key protein during TLS, confirmed this hypothesis.

Hemoglobin A1c predicts hemorrhagic transformation and poor outcomes after acute anterior stroke

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a major complication of acute ischaemic stroke that is potentially related to clinical deterioration. The objective of this study was to assess whether chronic hyperglycemia is a predictive factor of HT in patients with acute anterior stroke.

METHODS

Patients with acute anterior stroke were included in this study. Hemoglobin A1c (HbA1c) was measured in the morning after hospitalization. HT was detected by computed tomography scans or gradient echo magnetic resonance imaging performed 4 (±2) days after onset. Univariate and multivariate logistic regression analyses were used to assess the risks for HT and short-term outcomes.

RESULTS

Of the 426 patients included, 93 (21.8%) had HT: 61 (14.3%) presented with hemorrhagic infarction and 32 (7.5%) presented with parenchymal hematoma. A total of 54 patients received thrombolytic treatment and 18 (33.3%) were found to have HT. In the multivariate analysis, HbA1c [odds ratio (OR), 1.294; 95% confidence interval (CI), 1.097-1.528], infarction size (OR, 3.358; 95% CI, 1.748-6.449) and thrombolytic therapy (OR, 3.469; 95% CI, 1.757-6.847) were predictors of HT. The predictive effect of HbA1c on HT was still observed in both groups when patients were stratified according to the levels of fasting blood glucose. HbA1c was found to be a predictor of poor outcomes in the multilogistic regression analysis (OR, 1.482; 95% CI, 1.228-1.788).

CONCLUSIONS

Higher HbA1c was independently related to HT and poor neurological outcomes in patients with ischaemic stroke. These findings have significant implications for the treatment of diabetes and glucose management in patients with diabetes mellitus and/or acute ischaemic stroke.

Multiscale prediction of acoustic properties for glass wools: Computational study and experimental validation

This work is concerned with the multiscale prediction of the transport and sound absorption properties associated with industrial glass wool samples. In the first step, an experimental characterization is performed on various products using optical granulometry and porosity measurements. A morphological analysis, based on scanning electron imaging, is further conducted to identify the probability density functions associated with the fiber angular orientation. The key morphological characterization parameters of the microstructure, which serve as input parameters of the model, include the porosity, the weighted volume diameter accounting for both lengths and diameters of the analyzed fibers (and therefore the specific surface area of the random fibrous material), and the preferred out-of-plane fiber orientation generated by the manufacturing process. A computational framework is subsequently proposed and allows for the reconstruction of an equivalent fibrous network. A fully stochastic microstructural model, parameterized by the probability laws inferred from the database, is also proposed herein. Multiscale simulations are carried out to estimate transport properties and sound absorption. With no adjustable parameter, the results accounting for ten different samples obtained with various processing parameters are finally compared with the experimental data and used to assess the relevance of the reconstruction procedures and the multiscale computations.

Projections for the changes in growing season length of tree-ring formation on the Tibetan Plateau based on CMIP5 model simulations

The response of the growing season to the ongoing global warming has gained considerable attention. In particular, how and to which extent the growing season will change during this century is essential information for the Tibetan Plateau, where the observed warming trend has exceeded the global mean. In this study, the 1960-2014 mean length of the tree-ring growing season (LOS) on the Tibetan Plateau was derived from results of the Vaganov-Shashkin oscilloscope tree growth model, based on 20 composite study sites and more than 3000 trees. Bootstrap and partial correlations were used to evaluate the most significant climate factors determining the LOS in the study region. Based on this relationship, we predicted the future variability of the LOS under three emission scenarios (Representative Concentration Pathways (RCP) 2.6, 6.0, and 8.5, representing different concentrations of greenhouse gasses) derived from 17 Earth system models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The averaged LOS on the Tibetan Plateau is 103 days during the period 1960-2014, and April-September minimum temperature is the strongest factor controlling the LOS. We detected a general increase in the LOS over the twenty-first century under all the three selected scenarios. By the middle of this century, LOS will extend by about 3 to 4 weeks under the RCPs 2.6 and 6.0, and by more than 1 month (37 days) under the RCP 8.5, relative to the baseline period 1960-2014. From the middle to the end of the twenty-first century, LOS will further extend by about 3 to 4 weeks under the RCPs 6.0 and 8.5, respectively. Under the RCP 2.6 scenario, however, the extension reaches a plateau at around 2050 and about 2 weeks LOS extension. In total, we found an average rate of 2.1, 3.6, and 5.0 days decade^-1 for the LOS extension from 2015 to 2100 under the RCPs 2.6, 6.0, and 8.5, respectively. However, such estimated LOS extensions may be offset by other ecological factors that were not included into the growth model. The estimated lengthening of the growing season could substantially affect carbon sequestration and forest productivity on the Tibetan Plateau.

A pilot serosurvey of Babesia microti in Chinese blood donors

BACKGROUND AND OBJECTIVES

Babesia spp. are tick-borne, intraerythrocytic protozoan parasites, several of which are transfusion-transmissible. Transfusion-transmitted babesiosis poses serious risk to a diverse patient population, including neonates, patients aged >50 years, the asplenic and the immunocompromised that are over-represented among transfusion recipients. Despite reports of B. microti and B. venatorum in People's Republic of China (PRC), no surveillance of blood donors for Babesia has previously been undertaken. We sought to determine the rates of B. microti seroreactivity in a sample of blood donors in the PRC.

MATERIALS AND METHODS

A pilot serosurvey was conducted of community blood donors (n = 1000) who donated July-August 2016 at Mudanjiang Blood Center (Heilongjiang Province) using indirect fluorescent antibody testing for antibodies against B. microti. The slides were prepared using B. microti-infected hamster blood. Samples that were initially positive to a titre of 64 were subjected to repeat IFA testing. Final seroreactivity was based on repeat reactivity to ≥64.

RESULTS

A total of 1000 individual donor samples were evaluated, comprising 888 whole blood and 112 platelet donations. Thirteen of 1000 (1·3%) donors were seroreactive for B. microti [8 (0·8%) and five (0·05%) at titres of 64 and 128, respectively].

CONCLUSION

Our preliminary findings support the need for expanded Babesia surveillance in Chinese blood donors, replete with molecular evaluation, to evaluate the risk to the blood supply.

Metal-to-Ligand Charge-Transfer-based Visual Detection of Alkaline Phosphatase Activity

The ability to directly detect alkaline phosphatase (ALP) activity in undiluted serum samples is of great importance for clinical diagnosis. In this work, we report the use of the distinctive metal-to-ligand charge-transfer (MLCT) absorption properties of the Cu(BCA)₂⁺ (BCA = bicinchoninic acid) reporter for the visual detection of ALP activity. In the presence of ALP, the substrate ascorbic acid 2-phosphate (AAP) can be enzymatically hydrolyzed to release ascorbic acid (AA), which in turn reduces Cu²⁺ to Cu⁺. Subsequently, the complexation of Cu⁺ with the BCA ligand generates the chromogenic Cu(BCA)₂⁺ reporter, accompanied by a color change of colorless-to-purple of the solution with a sharp absorption band at 562 nm. The underlying MLCT-based mechanism has been demonstrated on the basis of density functional theory (DFT) calculations. Needless of any sequential multistep operations and elaborately designed colorimetric probe, the proposed MLCT-based method allows for a fast and sensitive visual detection of ALP activity within a broad linear range of 20 - 200 mU mL^-1 (R² = 0.999), with a detection limit of 1.25 mU mL^-1. The results also indicate that it is highly selective and has great potential for the screening of ALP inhibitors in drug discovery. More importantly, it shows a good analytical performance for the direct detection of the endogenous ALP levels of undiluted human serum samples. Owing to the prominent simplicity and practicability, it is reasonable to conclude that the proposed MLCT-based method has a high application prospect in clinical diagnosis.

Inverse association between plasma homocysteine concentrations and type 2 diabetes mellitus among a middle-aged and elderly Chinese population

BACKGROUND AND AIMS

Plasma homocysteine concentrations have been reported to be associated with type 2 diabetes mellitus (T2DM) with controversial findings. The aim of the present study was to investigate the association between plasma homocysteine concentrations and T2DM.

METHODS AND RESULTS

A cross-sectional study including 19,085 eligible participants derived from the Dongfeng-Tongji cohort was conducted. Plasma homocysteine concentrations were measured by Abbott Architect i2000 Automatic analyzer and T2DM was defined according to American Diabetes Association criteria. Logistic regression model was used to explore the association between plasma homocysteine concentrations and T2DM. The prevalence of T2DM was 19.0% in the whole population (mean age 62.9 years), 21.8% in males, and 17.1% in females. In the multivariable logistic regression analyses, compared with those in the lowest quintile, the OR (95% CI) of T2DM was 1.05 (0.92-1.21), 0.99 (0.86-1.14), 0.90 (0.78-1.05), and 0.77 (0.66-0.90) for quintile 2 to quintile 5 of homocysteine concentrations after adjustment for potential confounders (P for trend < 0.0001). Homocysteine concentrations were associated with decreased T2DM prevalence risk (OR = 0.88 per SD increase of homocysteine concentration; 95% CI: 0.84-0.93). A significant interaction between homocysteine concentrations and drinking status on T2DM prevalence risk was observed (P for interaction = 0.03). The inverse association of plasma homocysteine concentrations with T2DM prevalence risk was observed in non-drinkers but not in current drinkers.

CONCLUSION

Plasma homocysteine concentrations were inversely correlated with T2DM among a middle-aged and elderly Chinese population.

Associations between daily cooking duration and the prevalence of diabetes and prediabetes in a middle-aged and elderly Chinese population: A cross-sectional study

Experimental and epidemiological studies indicated that ambient air pollution was positively associated with diabetes. Few studies investigated the associations between household air pollution, for example, daily cooking duration and diabetes or prediabetes. We conducted a cross-sectional study to investigate the associations of daily cooking duration with the prevalence of diabetes and prediabetes among a middle-aged and elderly population. A total of 26 089 individuals (11 250 males and 14 839 females) derived from the Dongfeng-Tongji cohort study were included. Daily cooking duration was assessed by questionnaire. Diabetes and prediabetes were identified according to the criterion of American Diabetes Association. No significant association was observed between daily cooking duration and the prevalence risk of diabetes (odds ratio[OR] = 0.97, 95% confidence interval[CI]: [0.81-1.16], P for trend = .74); however, longer daily cooking duration was associated with higher prevalence risk of prediabetes (OR = 1.26, 95% CI: 1.07-1.47; P for trend = .003) and hyperglycemia (OR = 1.21, 95% CI: 1.05-1.41; P for trend = .005). Our study suggested that daily cooking duration was not associated with diabetes but with higher prevalence risk of prediabetes/hyperglycemia in a middle-aged and elderly Chinese population.