Stillbirths in China: a nationwide survey

Objective

To estimate a stillbirth rate at 24 or more gestational weeks in 2015–2016 and to explore potentially preventable causes in China.

Design

A multi‐centre cross‐sectional study.

Setting

Ninety‐six hospitals distributed in 24 (of 34) provinces in China.

Population

A total of 75 132 births at 24 completed weeks of gestation or more.

Methods

COX Proportional Hazard Models were performed to examine risk factors for antepartum and intrapartum stillbirths. Population attributable risk percentage was calculated for major risk factors. Correspondence analysis was used to explore region‐specific risk factors for stillbirths.

Main outcome measures

Stillbirth rate and risk factors for stillbirth.

Results

A total of 75 132 births including 949 stillbirths were used for the final analysis, giving a weighted stillbirth rate of 13.2 per 1000 births (95% CI 7.9–18.5). Small for gestational age (SGA) and pre‐eclampsia/eclampsia increased antepartum stillbirths by 26.2% and 11.7%, respectively. Fetal anomalies increased antepartum and intrapartum stillbirths by 17.9% and 7.4%, respectively. Overall, 31.4% of all stillbirths were potentially preventable. Advanced maternal age, pre‐pregnant obesity, chronic hypertension and diabetes mellitus were important risk factors in East China; low education and SGA were major risk factors in Northwest, Southwest, Northeast and South China; and pre‐eclampsia/eclampsia and intrapartum complications were significant risk factors in Central China.

Conclusions

The prevalence of stillbirth was 13.2 per 1000 births in China in 2015–2016. Nearly one‐third of all stillbirths may be preventable. Strategies based on regional characteristics should be considered to reduce further the burden of stillbirths in China.

Tweetable abstract

The stillbirth rate was 13.2 per 1000 births in China in 2015–2016 and nearly one‐third of all stillbirths may be preventable.

The stillbirth rate was 13.2 per 1000 births in China in 2015–2016 and nearly one‐third of all stillbirths may be preventable.

[Down-regulation of SIRT1 and PGC-1α expression caused by hyperoxia induces mitochondrial dysfunction in human alveolar epithelial cells]

Objective To investigate SIRT1-PGC-1α signaling pathway-mediated effect of hyperoxia on mitochondrial function in A549 human alveolar epithelial cells and its possible mechanism. Methods Human alveolar epithelial cells in logarithmic growth phase were randomly divided into control group and hyperoxia group. The control group was cultured in a 37DegreesCelsius, 50 mL/L CO₂ saturated humidity incubator, and the hyperoxia group was treated with 950 mL/L O₂. Following 24-hour culture, Mito SOX^TM staining was used to detect the level of mitochondrial reactive oxygen species (Mito-ROS) and JC-1 staining to detect the mitochondrial membrane potential. Real-time quantitative PCR was performed to detect the mitochondrial DNA content and the mRNA levels of SIRT1, PGC-1α, nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), and Western blotting to detect the protein levels of SIRT1, PGC-1α, NRF1 and TFAM. Results Compared with the control group, the Mito-ROS of the hyperoxia group increased significantly, while the membrane potential decreased obviously; the mitochondrial DNA content of the hyperoxia group went down, and the mRNA and protein expression of SIRT1, PGC-1α, NRF1 and TFAM dropped. Conclusion Hyperoxia induces mitochondrial dysfunction in human alveolar epithelial cells by inhibiting the expression of SIRT1 and PGC-1α.

Prognostic Impact of the Number of Examined Lymph Nodes in Stage II Colorectal Adenocarcinoma: A Retrospective Study

BACKGROUND

Evaluation of lymph node status is critical in colorectal carcinoma (CRC) treatment. However, as patients with node involvement may be incorrectly classified into earlier stages if the examined lymph node (ELN) number is too small and escape adjuvant therapy, especially for stage II CRC. The aims of this study were to assess the impact of the ELN on the survival of patients with stage II colorectal cancer and to determine the optimal number.

METHODS

Data from the US Surveillance, Epidemiology, and End Results (SEER) database on stage II resected CRC (1988-2013) were extracted for mathematical modeling as ELN was available since 1988. Relationship between ELN count and stage migration and disease-specific survival was analyzed by using multivariable models. The series of the mean positive LNs, odds ratios (ORs), and hazard ratios (HRs) were fitted with a LOWESS (Locally Weighted Scatterplot Smoothing) smoother, and the structural break points were determined by the Chow test. An independent cohort of cases from 2014 was retrieved for validation in 5-year disease-specific survival (DSS).

RESULTS

An increased ELN count was associated with a higher possibility of metastasis LN detection (OR 1.010, CI 1.009-1.011, p < 0.001) and better DSS in LN negative patients (OR 0.976, CI 0.975-0.977, p < 0.001). The cut-off point analysis showed a threshold ELN count of 21 nodes (HR 0.692, CI 0.667-0.719, p < 0.001) and was validated with significantly better DSS in the SEER 2009 cohort CRC (OR 0.657, CI 0.522-0.827, p < 0.001). The cut-off value of the ELN count in site-specific surgeries was analyzed as 20 nodes in the right hemicolectomy (HR 0.674, CI 0.638-0.713, p < 0.001), 19 nodes in left hemicolectomy (HR 0.691, CI 0.639-0.749, p < 0.001), and 20 nodes in rectal resection patients (HR 0.671, CI 0.604-0.746, p < 0.001), respectively.

CONCLUSIONS

A higher number of ELNs are associated with more-accurate node staging and better prognosis in stage II CRCs. We recommend that at least 21 lymph nodes be examined for accurate diagnosis of stage II colorectal cancer.

Light-controllable metasurface for microwave wavefront manipulation

Applying multiple physical fields to artificial manipulate electromagnetic waves is a highly stirring research. In this paper, we creatively combine light control with microwave scattering, realizing an optically coding metasurface for beam deflection based on anomalous reflection. A photoresistor and a voltage-driven module are connected to control each row of PIN-diode-loaded unit cells, endowing the reflection phase of the elements with a strong dependence on light. Owing to the high sensitivity of photoresistor, the digital element state "0" or "1" can be switched effectively via light variation sensed by the photoresistor. By modulating the light signal, the arrangement of digital elements can be reprogrammed, generating the specific scattering field. Therefore, the electromagnetic field can be determined by the spatial distribution of light, which induces the connect with the optical information and microwave field. The simulated and experimental results demonstrate the feasibility of our design. This light-steering approach provides a dimension for electromagnetic wave modulation.

Adaptation of Rice to the Nordic Climate Yields Potential for Rice Cultivation at Most Northerly Site and the Organic Production of Low-Arsenic and High-Protein Rice

There is an urgent demand for low-arsenic rice in the global market, particularly for consumption by small children. Soils in Uppsala, Sweden, contain low concentrations of arsenic (As). We hypothesize that if certain japonica paddy rice varieties can adapt to the cold climate and long day length in Uppsala and produce normal grains, such a variety could be used for organic production of low-arsenic rice for safe rice consumption. A japonica paddy rice variety, "Heijing 5," can be cultivated in Uppsala, Sweden, after several years' adaptation, provided that the rice plants are kept under a simple plastic cover when the temperature is below 10°C. Uppsala-adapted "Heijing 5" has a low concentration of 0.1 mg per kg and high protein content of 12.6% per dry weight in brown rice grain, meaning that it thus complies with all dietary requirements determined by the EU and other countries for small children. The high protein content is particularly good for small children in terms of nutrition. Theoretically, Uppsala-adapted "Heijing 5" can produce a yield of around 5100 kg per ha, and it has a potential for organic production. In addition, we speculate that cultivation of paddy rice can remove nitrogen and phosphorus from Swedish river water and reduce nutrient loads to the Baltic Sea and associated algae blooms.

Using β-ocimene to increase the artemisinin content in juvenile plants of Artemisia annua L

OBJECTIVE

The anti-malarial drug, artemisinin, is harvested from the leaves of adult Artemisia annua L. plants. As its concentration in juvenile plants is very low, the present study aimed to assess if the airborne signaling molecule, β-ocimene, could be used to enhance artemisinin accumulation in juvenile A. annua plants.

RESULTS

Application of exogenous β-ocimene increased artemisinin accumulation in A. annua. Treatment with 10 µM β-ocimene for 4 days resulted in juvenile plants accumulating artemisinin contents of up to 25 mg/g (2.5%) of dry weight. The expression levels of key genes encoding enzymes involved in both precursor biosynthetic pathways and artemisinin biosynthetic pathways induced by β-ocimene were upregulated. Glandular secretory trichome (GST) size and density increased by 49.2% and 38.2%, respectively, along with the upregulation of genes associated with GST development.

CONCLUSION

β-ocimene enhances artemisinin accumulation in juvenile A. annua plants by modulating artemisinin biosynthetic pathways and GST development.

A141 ENDOSCOPIST PROCEDURAL VOLUME AND COLONOSCOPY OUTCOMES: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

In addition to monitoring adverse events (AEs) and post-colonoscopy colorectal cancers (PCCRC), several indicators are used to assess the overall quality of colonoscopy performance, including adenoma detection rate (ADR) and cecal intubation rate (CIR). It is unclear whether there is an association between an endoscopist’s annual colonoscopy volumes and ADR, CIR, AEs or PCCRC.

Aims

We performed a systematic review and meta-analysis to determine whether there is an association between annual colonoscopy volume and colonoscopy quality indicators, or between annual volume and colonoscopy outcomes.

Methods

A comprehensive electronic search was performed through March of 2019 for any studies assessing the potential association between annual colonoscopy volume and outcomes, or quality indicators, including ADR, CIR, AEs or PCCRC. Pooled odds ratios (OR) were calculated using DerSimonian and Laird random effects models. Subgroup and sensitivity analyses were also performed to assess for any potential methodological or clinical factors associated with outcomes. These included dividing procedural volume into total procedures or screening procedures performed.

Results

Out of an initial 9,235 studies, 27 were included in our systematic review, representing 11,276,244 colonoscopies performed by over 530 endoscopists. There was no association between procedural volume and ADR (OR 1.00, 95% confidence intervals, CI, 0.98 to 1.02 per additional 100 annual total colonoscopy procedures performed by an endoscopist). CIR was improved with each additional 100 annual colonoscopy procedures (OR 1.17, 95% CI 1.08 to 1.28). There was a trend toward decreased overall adverse events per additional 100 annual procedures that did not meet significance (OR 0.95, 95% CI 0.90 to 1.00), although there was a decreased incidence of colonic perforations with increasing colonoscopy volume. Figure 1 - Forest plots demonstrating the odds of A) detecting an adenoma, B) intubating the cecum, and C) incurring an overall or specific adverse event, per additional 100 annual procedures, for total and screening procedures.

Conclusions

In this meta-analysis, higher annual colonoscopy volumes correlated with higher CIR, but not with ADR or PCCRC. Trends toward lower AE rates were also demonstrated with higher volumes. All studies included in this review examined endoscopists performing above respective recommended minimum volume thresholds for their health region. Thus, data are lacking on endoscopists performing very low numbers or very high numbers of colonoscopies annually. Future studies should focus on measuring colonoscopy quality metrics and outcomes among these extreme performers to more clearly determine associations between annual volume and colonoscopy outcomes.

Funding Agencies

Alberta Health Services Digestive Health Strategic Care Network

Preoperative mechanical bowel preparation with oral antibiotics reduces surgical site infection after elective colorectal surgery for malignancies: results of a propensity matching analysis

BACKGROUND

Surgical site infections (SSIs) are a major postoperative complication after colorectal surgery. Current study aims to evaluate prophylactic function of oral antibiotic (OA) intake in combination with mechanical bowel preparation (MBP) relative to MBP alone with respect to postoperative SSI incidence.

METHODS

A retrospective analysis of eligible patients was conducted using the databases of the Gastrointestinal Surgery Centre, Third Affiliated Hospital of Sun Yat-sen University from 2011 to 2017. Data pertaining to postoperative hospital stay length, expenses, SSI incidence, anastomotic fistula incidence, and rates of other complications were extracted and compared. A propensity analysis was conducted to minimize bias associated with demographic characteristics. Subgroup analyses were performed to further explore protective effects of OA in different surgical sites.

RESULTS

The combination of OAs and MBP was related to a significant decrease in the incidence of overall SSIs, superficial SSI, and hospitalization expenses. The MBP + OA modality was particularly beneficial for patients undergoing left-side colon or rectum resections, with clear prophylactic efficacy. The combination of MPB + OA did not exhibit significant prophylactic efficacy in patients undergoing right hemi-colon resection. Age, surgical duration, and application of OA were all independent factors associated with the occurrence of SSIs.

CONCLUSION

These results suggest that the combination of OA + MBP should be recommended for patients undergoing elective colorectal surgery, particularly for operations on the left side of the colon or rectum.

TRIAL REGISTRATION

NCT04258098. Retrospectively registered.

The Changes of Twist1 Pathway in Pulmonary Microvascular Permeability in a Newborn Rat Model of Hyperoxia-Induced Acute Lung Injury

Background: Bronchopulmonary dysplasia (BPD) is a chronic lung disease in preterm infants, which is characterized by alveolar and vascular dysplasia and increased vascular permeability. Hyperoxia is a critical factor in the pathogenesis of BPD, hyperoxia-induced acute lung injury (HALI) model has similar pathological manifestations as human BPD, therefore, may provide insight into the pathogenesis of human BPD. Studies have shown that Twist1 regulates pulmonary vascular permeability of LPS-induced lung injury through the Ang-Tie2 pathway. However, the effect of Twist1 pathway on vascular permeability in HALI has not been reported. Methods: We randomly exposed newborn rats to the room air or hyperoxia for 14 days. Lung histopathology, immunofluorescence, vascular permeability, mRNA and protein expression was assessed on day 1,7,14. Results: Our results verified that hyperoxia caused alveolar and vascular developmental disorders and increased pulmonary vascular permeability, which was consistent with previous findings. In hyperoxia-exposed rat lungs, the expressions of Twist1, Ang1, Tie1, Tie2, and pTie2 were significantly reduced, whereas the expression of Ang2 was significantly increased. Next, we observed a significant down-regulation of the Akt/Foxo1 pathway. Conclusion: In HALI, the pulmonary microvascular permeability was increased, accompanied by changes in Twist1-Tie2 pathway which combined to Angs, and downregulation of Tie1 and Akt/Foxo1 pathway.

Arabidopsis ZUOTIN RELATED FACTOR1 Proteins Are Required for Proper Embryonic and Post-Embryonic Root Development

The H2A/UBIQUITIN-binding proteins AtZRF1a/b have been reported as key regulators involved in multiple processes of Arabidopsis plant growth and development. Yet, the cellular and molecular mechanisms underlying the mutant phenotype remain largely elusive. Here we show that loss-of-function of AtZRF1a/b causes defective root elongation and deformed root apical meristem organization in seedlings. The premature termination of the primary root in the atzrf1a;atzrf1b double mutant is associated with an advanced onset of endoreduplication and subsequent consumption of reservoir stem cells. Cytological analyses using cell type-specific markers and florescent dyes indicate that AtZRF1a/b are involved in maintenance of proper cell layer organization, determinacy of cell identity, and establishment of auxin gradient and maximum at the root tip. During embryogenesis AtZRF1a/b act dominantly in regulating the maintenance of ground tissue initial cells and production of lateral root cap. Lastly, quantitative real-time polymerase chain reaction analysis shows mis-expression of some key genes involved in regulating cell patterning, cell proliferation and/or hormone pathways. Our results provide important insight into AtZRF1a/b function in cell fate determinacy and in establishment and maintenance of proper stem cell reservoir during embryonic and post-embryonic root development.

[Association between edentulism and cognition among people aged 50 and over]

Objective: To investigate the association between edentulism and cognition in people aged 50 and over in China. Methods: Cross-sectional data was collected from the first wave of World Health Organization Study on global AGEing and adult health in China, among people aged 50 and over in China. A comprehensive cognitive test was used to assess cognitive functions, including verbal recall (VR), verbal fluency (VF), forward digit span (FDS) and backward digit span (BDS) among the subjects. Association between edentulism and cognition was examined by a two-level (individual level and community level) linear model. Results: A total of 12 843 individuals aged 50 years and over were included for analysis, with an average age of (63.0±9.3) years. The overall prevalence of edentulism was 11.0%. The edentulous adults had lower mean scores of VR (4.55), VF (10.88), FDS (6.25), BDS (2.96) and overall cognition (49.15) (P<0.001). Edentulism was negatively associated with VR (β=-0.216, 95%CI: -0.370 - -0.062), FDS (β=-0.186, 95%CI: -0.293 - -0.078) and overall cognition (β=-1.703, 95%CI: -3.025 - -0.381) after adjusted for age, sex, residence, education level, marital status, household income, co-morbidity of chronic conditions, BMI, smoking and drinking alcohol. Conclusion: Edentulism was related with lower cognition level in people aged 50 and over in China.

[Association between daily sedentary time and frailty among people aged 50 years and over]

Objective: To investigate the association between daily sedentary time and frailty among people aged 50 years and over. Methods: Cross-sectional data was collected from the first wave of World Health Organization Study on global AGEing and adult health in China. A two-level (individual level and community level) logistic model was performed to identify the association between daily sedentary time and frailty. The dose-response relationship between them was analyzed by restrictive cubic spline curve. Results: A total of 13 175 individuals aged 50 years and over were included for analysis. A positive association between daily sedentary time and frailty was noticed, both in urban (OR=1.22, 95%CI: 1.17-1.27) or rural areas (OR=1.11, 95%CI: 1.05-1.18) under study. The dose-response curve showed that daily sedentary time and frailty might present an approximate linear relationship. Conclusion: Results from this study showed significant association exsited between daily sedentary time and frailty, approximately with a linear dose-response relationship.

[Association between frailty and sleep duration among people aged 50 years and over]

Objective: To investigate the association between sleep duration and frailty among people aged 50 years and over. Methods: Cross-sectional data was collected from the first wave of World Health Organization Study on global AGEing and adult health in China. Frailty index was constructed on the proportion of deficits, out of the 40 variables. A two-level (individual level and community level) linear model was performed to identify the related factors on frailty. All the models were stratified by age, gender, residence (urban/rural). Restricted cubic spline was performed to graphically evaluate the dose-response association between self-reported sleep duration and frailty. Results: A total of 13 175 individuals aged 50 years and over participated in this study. Without adjusting on any confounding factors, shorter or longer sleep duration significantly increased the risk of weakness compared with normal sleep time (OR=2.05, 95%CI: 1.71-2.44; OR=1.35, 95%CI: 1.12-1.63). After adjusting for confounding factors such as gender, age, residence, education, family assets, vegetable, smoking, drinking and physical activity, a positive association between short sleep duration and frailty was noticed compared with normal sleep time (aOR=1.60, 95%CI: 1.27-2.01). The results of stratified analysis on sex, age and urban and rural areas showed that, after adjusting for gender, age, residence, education level, family assets, intake of vegetables and fruits, smoking, drinking and physical activity, only shorter sleep duration was positively correlated with the risk of weakness. In addition, among people aged 65 years and over, adjusted for confounding factors, the risk of weakness increased by 91%, compared with normal sleep time (aOR=1.91, 95%CI: 1.46-2.49). The dose-response curve also showed that the sleep duration and frailty present an approximate "U" shaped relationship. Conclusion: Short sleep duration might be associated with frailty.

[Association between low handgrip strength and air pollution among people aged 50 years and over]

Objective: To examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and handgrip strength among people aged 50 and over. Methods: Data were from the first wave of World Health Organization Study on global AGEing and adult health in China. Ambient annual concentration of PM(2.5) was estimated by using the satellite data we also investigated the use of fuels and chimneys as indoor air pollution. A two-level (individual level and community level) linear model was applied to examine the association between long-term exposure to ambient PM(2.5) combined with indoor air pollution and the handgrip strength. Results: A total of 13 175 individuals aged 50 years and over were included for analysis. The handgrip strength was (26.67±0.54) kg. Ambient PM(2.5) was found to be significantly associated with the risk of decreased handgrip strength. Outdoor PM(2.5) concentration was negatively correlated with handgrip strength (β=-0.23, 95%CI: -0.31 - -0.14) decrease in handgrip strength after adjusting for gender, age, residence, education, household assets, intake of vegetables and fruits, smoking and drinking, physical activity. In rural area, compared to those who used solid fuel, use of clean fuel increased (β=1.41, 95%CI: 0.36-2.46) handgrip strength. But in urban area, we did not find any statistically significant association between the use of clean fuel and handgrip strength (β=0.19, 95%CI: -0.95-1.32). Conclusion: This study found that long-term exposure to ambient PM(2.5) combined with indoor air pollution was significantly associated with low handgrip strength among people aged 50 years and over, this suggested that ambient PM(2.5) might serve as one of the risk factors for low physical function seen in the people aged 50 years and over.

[Project profile: Study on global AGEing and adult health in China]

With accelerating and rapid ageing in China, there is an urgent need to collect reliable, valid and cross-nationally comparable data on health in the elderly to provide basis for richer and empirical analysis on the changing health over one's life course and compression of morbidity. To meet the demands of this growing special population, planning and preparing on related social protection mechanisms (health and pension systems) should also based on evidence-based decision-making process. Based on long-term follow-up, large scale cohort study is indispensible for the etiology of common chronic diseases and disabling conditions. This study aims to introduce the background, project objectives, contents, baseline characteristics, strength and weakness as well as prospect, related to the Study on global AGEing and adult health in China.

The Molecular Mechanism of Sirt1 Signaling Pathway in Brain Injury of Newborn Rats Exposed to Hyperoxia

The aim of the study was to investigate the changes in the reactive oxygen species (ROS), Sirt1, p53 and acetylated p53 in brain tissue of newborn rats exposed to hyperoxia to clarify the role of Sirt1 signaling pathway in brain injury. Neonate rats were randomly divided into normoxic group and hyperoxic group. Rats in the normoxic group were exposed to room air while the rats in the hyperoxic group were put in a hyperoxic chamber (80 ± 5% oxygen) for 1 to 14 d. Data, including weight growth, the water content of brain tissue, hematoxyline and eosin (H&E) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (Tunel) stain, ROS expression, the relative expression of Sirt1 mRNA and p53 mRNA, and the protein relative expression of Sirt1, p53 and acetylated p53 were analyzed at 1, 7 and 14 d after exposure. A reduced body weight and increased water content were observed in the brain tissue of hyperoxic group compared to normoxic group. HE staining and Tunel staining of brain tissue suggested that cell damaged after hyperoxic exposure. RT-PCR and Western blot results showed that the expression of Sirt1 in the hyperoxic group was lower than that in the normoxic group while the expression of p53 was higher than that in the normoxic group. In addition, Western blot data indicated acetylated p53 expression was higher in the hyperoxic group. Hyperoxic exposure can lead to brain injury in newborn Sprague-Dawley (SD) rats. These events might be regulated by the Sirt1 pathway, which downregulated the deacetylation of p53.

Genome-wide analysis of sulfotransferase genes and their responses to abiotic stresses in Chinese cabbage (Brassica rapa L.)

Sulfotransferases (SOTs; EC 2.8.2.-), which are widespread from prokaryotes to eukaryotes, constitute a multi-protein family that plays crucial roles in plant growth, development and stress adaptation. However, this family has not been systemically investigated in Brassica rapa. Here, a genome-wide systemic analysis of SOT genes in B. rapa subsp. pekinensis, a globally cultivated vegetable, were conducted. We identified 56 SOT genes from the whole B. rapa genome using Arabidopsis SOT sequences as queries and classified them into nine groups, rather than the eight groups of previous research. 56 B. rapa SOT genes (BraSOTs) were distributed on all 10 chromosomes except for chromosome 5. Of these, 27 BraSOTs were distributed in seven clusters on five chromosomes (ChrA01, ChrA02, Chr03, ChrA07, and Chr09). Among the BraSOT proteins, 48 had only one SOT_1 domain and 6 had two, while 2 had one SOT_3 domain. Additionally, 47 BraSOT proteins contained only known SOT domains. The remaining nine proteins, five in group-VIII and two in group-IX, contained additional transmembrane domains. Specific motif regions I and IV for 3′-phosphoadenosine 5′-phosphosulfate binding were found in 41 BraSOT proteins. Introns were present in only 18 BraSOT genes, and all seven BraSOT genes in groups VIII and IX had more than three introns. To identify crucial SOTs mediating the response to abiotic stress in B. rapa, expression changes in 56 BraSOT genes were determined by quantitative RT-PCR after drought, salinity, and ABA treatments, and some BraSOT genes were associated with NaCl, drought and ABA stress, e.g. Bra017370, Bra009300, Bra027880.

Liquid metal metasurface for flexible beam-steering

In this paper, we propose a reconfigurable metasurface based on liquid metal for flexible beam-steering. The Gallium alloy with low melting temperature (about 30°C) is employed for easy structure reconfiguration. By designing specific dimension of cavity, we make the liquid metal in it easily form into desired sizes, to generate distinct phase responses. Two metasurface elements with four phase responses are designed, simulated and measured. Based on the above elements, various scattering fields can be realized within our design. We present four schemes to achieve single- and dual-beam fields with different beam-deflecting angles. The measured results show great agreement with the simulations, validating our design. In addition, every two columns of the metasurface are grouped into a single composite form, which promises a customizable combination for metasurface pattern. Compared to the previous reconfigurable works for metasurfaces, the method via liquid metal possess lower cost, easier fabrication, and will further enrich the manipulation method for metasurfaces.

Evolution and conservation of polycomb repressive complex 1 core components and putative associated factors in the green lineage

Background

Polycomb group (PcG) proteins play important roles in animal and plant development and stress response. Polycomb repressive complex 1 (PRC1) and PRC2 are the key epigenetic regulators of gene expression, and are involved in almost all developmental stages. PRC1 catalyzes H2A monoubiquitination resulting in transcriptional silencing or activation. The PRC1 components in the green lineage were identified and evolution and conservation was analyzed by bioinformatics techniques. RING Finger Protein 1 (RING1), B lymphoma Mo-MLV insertion region 1 homolog (BMI1), Like Heterochromatin Protein 1 (LHP1) and Embryonic Flower 1 (EMF1) are the PRC1 core components and Vernalization 1 (VRN1), VP1/ABI3-Like 1/2/3 (VAL1/2/3), Alfin-like 1–7 (AL1–7), Inhibitor of growth 1/2 (ING1/2), and Early Bolting in Short Days (EBS) / Short Life (SHL) are the associated factors.

Results

Each PRC1 subunit possesses special domain organizations, such as RING and the ring finger and WD40-associated ubiquitin-like (RAWUL) domains for RING1 and BMI1, chromatin organization modifier (CHROMO) and chromo shadow (ChSh) domains for LHP1, one or two B3 DNA binding domain(s) for VRN1, B3 and zf-CW domains for VAL1/2/3, Alfin and Plant HomeoDomain (PHD) domains for AL1–7, ING and PHD domains for ING1/2, Bromoadjacent homology (BAT) and PHD domains for EBS/SHL. Six new motifs are uncovered in EMF1.

The PRC1 core components RING1 and BMI1, and the associated factors VAL1/2/3, AL1–7, ING1/2, and EBS/SHL exist from alga to higher plants, whereas LHP1 only occurs in higher plants. EMF1 and VRN1 are present only in eudicots. PRC1 components undergo duplication in the plant evolution. Most of plants carry the homologous core component LHP1, the associated factor EMF1, and several homologs in RING1, BMI1, VRN1, AL1–7, ING1/2/3, and EBS/SHL. Cabbage, cotton, poplar, orange and maize often exhibit more gene copies than other species. Domain organization analysis shows that duplicated gene functions may be of diverse.

Conclusions

The PRC1 core components RING1 and BMI1, and the associated factors VAL1/2/3, AL1–7, ING1/2, and EBS/SHL originate from algae. The core component LHP1 is from moss and the associated factors EMF1 and VRN1 are from dicotyledon. PRC1 components are of functional redundancy and diversity in evolution.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5905-9) contains supplementary material, which is available to authorized users.

Sodium chloride primes JA-independent defense against Spodoptera litura (Fabricius) larvae in Arabidopsis thaliana

Priming for better defense performance is an important strategy in acclimation to the ever-changing environment. In the present study, defense priming induced by sodium chloride at the seedling stage significantly increased the expression of defense gene VSP2, the content of total glucosinolates and the level of the reactive oxygen species in mature Arabidopsis thaliana plants after transferred into the stress-free environment. The previously primed plants could effectively resist the feeding of Spodoptera litura (Fabricius) larvae. Salt-priming enhanced defense of Arabidopsis plants in the absence of either MYC2 or AOS, which encodes a critical transcription factor in JA-signaling and an important enzyme in JA biosynthesis, respectively. Our results supported the JA-independent defense primed by sodium chloride, as well as the elevated ROS and glucosinolate level in primed plants. In addition, the feasibility of using mild salt-priming to improve crop performance in field was proposed.

Importance of inpatient hypoglycaemia: impact, prediction and prevention

Hypoglycaemia is a key barrier to achieving euglycaemic control in people who are hospitalized. Inpatient hypoglycaemia has been linked to adverse clinical outcomes, including mortality and longer stay in hospital. A number of studies have applied mathematical tools and statistical models to predict inpatient hypoglycaemia and identify factors that may result in hypoglycaemic events. Several different approaches have been tested to prevent inpatient hypoglycaemia. These can be categorized as human intervention, computerized methods or application of medical devices. In this review we provide an overview of the epidemiology of inpatient hypoglycaemia and its impact on patients and hospitals. We also discuss the existing methodology used to predict inpatient hypoglycaemia and the limited number of trials performed to prevent inpatient hypoglycaemia. The review highlights the urgent need for evidence-based methods to reduce inpatient hypoglycaemia.

Genome-wide analysis and stress-responsive expression of CCCH zinc finger family genes in Brassica rapa

BACKGROUND

Ubiquitous CCCH nucleic acid-binding motif is found in a wide-variety of organisms. CCCH genes are involved in plant developmental processes and biotic and abiotic stress responses. Brassica rapa is a vital economic crop and classical model plant of polyploidy evolution, but the functions of CCCH genes in B. rapa are unclear.

RESULTS

In this study, 103 CCCH genes in B. rapa were identified. A comparative analysis of the chromosomal position, gene structure, domain organization and duplication event between B. rapa and Arabidopsis thaliana were performed. Results showed that CCCH genes could be divided into 18 subfamilies, and segmental duplication might mainly contribute to this family expansion. C-X_7/8-C-X₅-C₃-H was the most commonly found motif, but some novel CCCH motifs were also found, along with some loses of typical CCCH motifs widespread in other plant species. The multifarious gene structures and domain organizations implicated functional diversity of CCCH genes in B. rapa. Evidence also suggested functional redundancy in at least one subfamily due to high conservation between members. Finally, the expression profiles of subfamily-IX genes indicated that they are likely involved in various stress responses.

CONCLUSION

This study provides the first genome-wide characterization of the CCCH genes in B. rapa. The results suggest that B. rapa CCCH genes are likely functionally divergent, but mostly involved in plant development and stress response. These results are expected to facilitate future functional characterization of this potential RNA-binding protein family in Brassica crops.

[Subjective well-being feelings and related factors in people aged 50 years or older in Shanghai: Based on Day Reconstruction Method]

Objective: To evaluate the subjective well-being feelings of people aged ≥50 years in Shanghai by using the Day Reconstruction Method (DRM) and explore the related factors. Methods: A cross-sectional survey was conducted from October 2009 to June 2010 among people aged ≥50 years selected through multistage random cluster sampling in Shanghai. DRM was used to assess participants' subjective well-being by net effect and U-index. Univariate and multivariate linear regression models were used to explore the related factors. Results: A total of 8 075 participants were included, with average age of 63.1 years. The mean net effect value was 1.24 (95%CI:1.15-1.33), and the mean U-index was 1.55% (95%CI:1.10%-1.99%). After adjusted for demographic factors, univariate liner regression model indicated that age, education level, marital status, family wealth, residence, self-rated health status, WHODAS score and prevalence of chronic disease were associated with subjective well-being, and multivariate liner regression model indicated that higher WHODAS score was associated with lower net effect value (P<0.05). Conclusion: The subjective well-being feelings of people aged ≥50 years in Shanghai might be associated with age, education level, marital status, family wealth, residence, self-rated health status and WHODAS score. Enhanced social support and appropriate social security system might facilitate the improvement of the subjective well-being of the elderly.