Structural insights into the calcium-coupled zinc export of human ZnT1

Cellular zinc (Zn2+) homeostasis is essential to human health and is under tight regulations. Human zinc transporter 1 (hZnT1) is a plasma membrane-localized Zn2+ exporter belonging to the ZnT family, and its functional aberration is associated with multiple diseases. Here, we show that hZnT1 works as a Zn2+/Ca2+ exchanger. We determine the structure of hZnT1 using cryo-electron microscopy (cryo-EM) single particle analysis. hZnT1 adopts a homodimeric structure, and each subunit contains a transmembrane domain consisting of six transmembrane segments, a cytosolic domain, and an extracellular domain. The transmembrane region displays an outward-facing conformation. On the basis of structural and functional analysis, we propose a model for the hZnT1-mediated Zn2+/Ca2+ exchange. Together, these results facilitate our understanding of the biological functions of hZnT1 and provide a basis for further investigations of the ZnT family transporters.

Cord Blood Transplantation for Very Early-Onset Inflammatory Bowel Disease Caused by Interleukin-10 Receptor Deficiency

PURPOSE

Interleukin-10 receptor (IL-10R) deficiency can result in life-threatening very early-onset inflammatory bowel disease (VEO-IBD). Umbilical cord blood transplantation (UCBT) is a curative therapy for patients with IL-10R deficiency. This study aimed to investigate the efficacy of UCBT in treating IL-10R deficiency and develop a predictive model based on pre-transplant factors.

METHODS

Eighty patients with IL-10R deficiency who underwent UCBT between July 2015 and April 2023 were retrospectively analyzed. Cox proportional hazards regression and random survival forest were used to develop a predictive model.

RESULTS

Median age at transplant was 13.0 months (interquartile range [IQR], 8.8-25.3 months). With a median follow-up time of 29.4 months (IQR, 3.2-57.1 months), the overall survival (OS) rate was 65.0% (95% confidence interval [CI], 55.3%-76.3%). The engraftment rate was 85% (95% CI, 77%-93%). The cumulative incidences of acute and chronic graft-versus-host disease were 48.2% (95% CI, 37.1%-59.4%) and 12.2% (95% CI, 4.7%-19.8%), respectively. VEO-IBD-associated clinical symptoms were resolved in all survivors. The multivariate analysis showed that IL-6 and stool occult blood were independent prognostic risk factors. The multivariate Cox proportional hazards regression model with stool occult blood, length- or height-for-age Z-score, medical history of sepsis, and cord blood total nucleated cells showed good discrimination ability, with a bootstrap concordance index of 0.767-0.775 in predicting OS.

CONCLUSION

Better inflammation control before transplantation and higher cord blood total nucleated cell levels can improve patient prognosis. The nomogram can successfully predict OS in patients with IL-10R deficiency undergoing UCBT.

Differences in prenatal diagnosis rate of congenital anomalies associated with singletons and multiple births: An observational study of more than 1.9 million births in Zhejiang Province, eastern China, during 2012-2018

OBJECTIVE

To characterize differences in the prenatal detection of congenital anomalies (CAs) associated with singleton and multiple births.

METHODS

This observational study covered all births registered in the CA surveillance system in Zhejiang Province of China during 2012-2018. Differences in the incidence and characteristics between singletons and multiple births with CAs were tested. Multivariate logistic regression models were performed to explore the associations of prenatal detection rate of CAs with multiple births.

RESULTS

Totals of 49 872 singletons and 3324 multiple births with CAs were analyzed. The mean incidences of CA for single and multiple births were 27.12 and 54.42 per 1000 births, respectively. After adjustment for covariates, CAs associated with multiple births were less likely to be diagnosed prenatally (adjusted odds ratio [OR] 0.38, 95% confidence interval [CI] 0.34-0.43), as were congenital heart defects, congenital hydrocephalus, cleft lip with cleft palate, cleft lip without cleft palate, limb reduction defects, congenital diaphragmatic hernia, trisomy 21 syndrome, congenital malformation of the urinary system, and other chromosomal malformation, compared with singletons with CAs.

CONCLUSION

Multiple birth is associated with a significantly higher risk of CA, but a significantly lower prenatal diagnosis rate. Therefore, the healthcare of women with multiple pregnancy and their fetuses should be strengthened.

Enhanced Multiwavelength Response of Flexible Synaptic Transistors for Human Sunburned Skin Simulation and Neuromorphic Computation

In biological species, optogenetics and bioimaging work together to regulate the function of neurons. Similarly, the light-controlled artificial synaptic system not only enhances computational speed but also simulates complex synaptic functions. However, reported synaptic properties are mainly limited to mimicking simple biological functions and single-wavelength responses. Therefore, the development of flexible synaptic devices with multiwavelength optical signal response and multifunctional simulation remains a challenge. Here, flexible organic light-stimulated synaptic transistors (LSSTs) enabled by alumina oxide (AlOX ), with a simple fabrication process, are reported. By embedding AlOX nanoparticles, the excitons separation efficiency is improved, allowing for multiple wavelength responses. Optimized LSSTs can respond to multiple optical and electrical signals in a highly synaptic manner. Multiwavelength optical synaptic plasticity, electrical synaptic plasticity, sunburned skin simulation, learning efficiency model controlled by photoelectric cooperative stimulation, neural network computing, "deer" picture learning and memory functions are successfully proposed, which promote the development for future artificial intelligent systems. Furthermore, as prepared flexible transistors exhibit mechanical flexibility with bending radius down to 2.5 mm and improved photosynaptic plasticity, which facilitating development of neuromorphic computing and multifunction integration systems at the device-level.

DNA Nanoribbon-Assisted Intracellular Biosynthesis of Fluorescent Gold Nanoclusters for Cancer Cell Imaging

Metal nanoclusters (NCs) have emerged as a promising class of fluorescent probes for cellular imaging due to their high resistance to photobleaching and low toxicity. Nevertheless, their widespread use in clinical diagnosis is limited by their unstable intracellular fluorescence. In this study, we develop an intracellularly biosynthesized fluorescent probe, DNA nanoribbon-gold NCs (DNR/AuNCs), for long-term cellular tracking. Our results show that DNR/AuNCs exhibit a 4-fold enhancement of intracellular fluorescence intensity compared to free AuNCs. We also investigated the mechanism underlying the fluorescence enhancement of AuNCs by DNRs. Our findings suggest that the higher synthesis efficiency and stability of AuNCs in the lysosome may contribute to their fluorescence enhancement, which enables long-term (up to 15 days) fluorescence imaging of cancer cells (enhancement of ∼60 times compared to free AuNCs). Furthermore, we observe similar results with other metal NCs, confirming the generality of the DNR-assisted biosynthesis approach for preparing highly bright and stable fluorescent metal NCs for cancer cell imaging.

Design, Modeling, and Control of an Aurelia-Inspired Robot Based on SMA Artificial Muscles

This paper presented a flexible and easily fabricated untethered underwater robot inspired by Aurelia, which is named "Au-robot". The Au-robot is actuated by six radial fins made of shape memory alloy (SMA) artificial muscle modules, which can realize pulse jet propulsion motion. The thrust model of the Au-robot's underwater motion is developed and analyzed. To achieve a multimodal and smooth swimming transition for the Au-robot, a control method integrating a central pattern generator (CPG) and an adaptive regulation (AR) heating strategy is provided. The experimental results demonstrate that the Au-robot, with good bionic properties in structure and movement mode, can achieve a smooth transition from low-frequency swimming to high-frequency swimming with an average maximum instantaneous velocity of 12.61 cm/s. It shows that a robot designed and fabricated with artificial muscle can imitate biological structures and movement traits more realistically and has better motor performance.

Spatiotemporal, physiological and transcriptomic dynamics of wild jujube seedlings under saline conditions

Soil salinity is a major constraint limiting jujube production in China. Wild jujube (Ziziphus jujuba var. spinosa (Bunge) Hu ex H. F. Chow) is widely used as the rootstock of jujube (Z. jujuba) to overcome the saline conditions. To understand the adaptive mechanism in wild jujube under saline conditions, we combined spatiotemporal and physiological assessments with transcriptomic analysis on wild jujube seedlings undergoing various salt treatments. These salt treatments showed dose and duration effects on biomass, photosynthesis, (K+) and (Na+) accumulation. Salt treatments induced higher levels of salicylic acid in roots and leaves, whereas foliar abscisic acid was also elevated after 8 days. The number of differential expression genes increased with higher doses and also longer exposure of NaCl treatments, with concomitant changes in the enriched Gene Ontology terms that were indicative of altered physiological activities. Gene co-expression network analysis identified the core gene sets associated with salt-induced changes in leaves, stems and roots, respectively. The nitrogen transporters, potassium transporters and a few transcription factors belonging to WRKY/MYB/bHLH families were clustered as the hub genes responding to salt treatments, which were related to elevated nitrogen and K+/Na+. Ectopic overexpression of two WRKY transcription factor genes (ZjWRKY6 and ZjWRKY65) conferred stronger salt-tolerance in Arabidopsis thaliana transformants by enhancing the activities of antioxidant enzymes, decreasing malondialdehyde accumulation and maintaining K+/Na+ homeostasis. This study provided evidence about the spatiotemporal, physiological and transcriptomic dynamics of wild jujube during salt stress and identified potential genes for further research to improve salt tolerance in jujube.

Cytokinin-responsive MdTCP17 interacts with MdWOX11 to repress adventitious root primordium formation in apple rootstocks

Adventitious root (AR) formation plays an important role in vegetatively propagated plants. Cytokinin (CK) inhibits AR formation, but the molecular mechanisms driving this process remain unknown. In this study, we confirmed that CK content is related to AR formation and further revealed that a high auxin/CK ratio was beneficial to AR formation in apple (Malus domestica). A correlation between expression of CK-responsive TEOSINTE BRANCHED1, CYCLOIDEA, and PCF17 (MdTCP17) and AR formation in response to CK was identified, and overexpression of MdTCP17 in transgenic apple inhibited AR formation. Yeast two-hybrid, bimolecular fluorescence complementation, and co-immunoprecipitation assays revealed an interaction between MdTCP17 and WUSCHEL-RELATED HOMEOBOX11 (MdWOX11), and a significant correlation between the expression of MdWOX11 and AR ability. Overexpression of MdWOX11 promoted AR primordium formation in apple, while interference of MdWOX11 inhibited AR primordium production. Moreover, a positive correlation was found between MdWOX11 and LATERAL ORGAN BOUNDARIES DOMAIN29 (MdLBD29) expression, and yeast one-hybrid, dual luciferase reporter, and ChIP-qPCR assays verified the binding of MdWOX11 to the MdLBD29 promoter with a WOX-box element in the binding sequence. Furthermore, MdTCP17 reduced the binding of MdWOX11 and MdLBD29 promoters, and coexpression of MdTCP17 and MdWOX11 reduced MdLBD29 expression. Together, these results explain the function and molecular mechanism of MdTCP17-mediated CK inhibition of AR primordium formation, which could be used to improve apple rootstocks genetically.

Prognostic factors of childhood acute lymphoblastic leukemia with TCF3::PBX1 in CCCG-ALL-2015: A multicenter study

BACKGROUND

Contemporary risk-directed treatment has improved the outcome of patients with acute lymphoblastic leukemia (ALL) and TCF3::PBX1 fusion. In this study, the authors seek to identify prognostic factors that can be used to further improve outcome.

METHODS

The authors studied 384 patients with this genotype treated on Chinese Children's Cancer Group ALL-2015 protocol between January 1, 2015 and December 31, 2019. All patients provisionally received intensified chemotherapy in the intermediate-risk arm without prophylactic cranial irradiation; those with high minimal residual disease (MRD) ≥1% at day 46 (end) of remission induction were candidates for hematopoietic cell transplantation.

RESULTS

The overall 5-year event-free survival was 84.4% (95% confidence interval [CI], 80.6-88.3) and 5-year overall survival 88.9% (95% CI, 85.5-92.4). Independent factors associated with lower 5-year event-free survival were male sex (80.4%, [95% CI, 74.8-86.4] vs. 88.9%, [95% CI, 84.1-93.9] in female, p = .03) and positive day 46 MRD (≥0.01%) (62.1%, [95% CI, 44.2-87.4] vs. 87.1%, [95% CI, 83.4-90.9] in patients with negative MRD, p < .001). The presence of testicular leukemia at diagnosis (n = 10) was associated with particularly dismal 5-year event-free survival (33.3% [95% CI, 11.6-96.1] vs. 83.0% [95% CI, 77.5-88.9] in the other 192 male patients, p < .001) and was an independent risk factor (hazard ratio [HR], 5.7; [95% CI, 2.2-14.5], p < .001).

CONCLUSIONS

These data suggest that the presence of positive MRD after intensive remission induction and testicular leukemia at diagnosis are indicators for new molecular therapeutics or immunotherapy in patients with TCF3::PBX1 ALL.

Mycorrhizal symbiosis reprograms ion fluxes and fatty acid metabolism in wild jujube during salt stress

Chinese jujube (Ziziphus jujuba) is an important fruit tree in China, and soil salinity is the main constraint affecting jujube production. It is unclear how arbuscular mycorrhizal (AM) symbiosis supports jujube adaptation to salt stress. Herein, we performed comparative physiological, ion flux, fatty acid (FA) metabolomic, and transcriptomic analyses to examine the mechanism of AM jujube responding to salt stress. AM seedlings showed better performance during salt stress. AM symbiosis altered phytohormonal levels: indole-3-acetic acid and abscisic acid contents were significantly increased in AM roots and reduced by salt stress. Mycorrhizal colonization enhanced root H+ efflux and K+ influx, while inducing expression of plasma membrane-type ATPase 7 (ZjAHA7) and high-affinity K+ transporter 2 (ZjHAK2) in roots. High K+/Na+ homeostasis was maintained throughout salt exposure. FA content was elevated in AM leaves as well as roots, especially for palmitic acid, oleic acid, trans oleic acid, and linoleic acid, and similar effects were also observed in AM poplar (Populus. alba × Populus. glandulosa cv. 84K) and Medicago truncatula, indicating AM symbiosis elevating FA levels could be a conserved physiological effect. Gene co-expression network analyses uncovered a core gene set including 267 genes in roots associated with AM symbiosis and conserved transcriptional responses, for example, FA metabolism, phytohormone signal transduction, SNARE interaction in vesicular transport, and biotin metabolism. In contrast to widely up-regulated genes related to FA metabolism in AM roots, limited genes were affected in leaves. We propose a model of AM symbiosis-linked reprogramming of FA metabolism and provide a comprehensive insight into AM symbiosis with a woody species adaptation to salt stress.

An Indicator Measuring the Influence of the Online Public Food Environment: An Analytical Framework and Case Study

The online public food environment (OPFE) has had a considerable impact on people's lifestyles over the past decade; however, research on its exposure is sparse. The results of the existing research on the impact of the food environment on human health are inconsistent. In response to the lack of food elements in the definition of the food environment and the lack of a clear method to assess the health attributes and the impact degree of the food environment, we proposed a new analytical framework based on the latest disease burden research, combining the characteristics of China's current food environment, from the perspective of environmental science. We redefined the food environment and proposed that food and its physical space are two core elements of the food environment. Accordingly, we extracted four domains of characteristics to describe the basic components of the food environment. Using the sales records, we designed an approach by referring to the standard process of environmental health indicators, including the health attributes and the impact degree of the food environment, to measure the OPFE of takeaway food outlets. Further, we conducted a case study and extracted three domains of characteristics for more than 18,000 effective takeaway meals from 812 takeaway food outlets located in 10 administrative subdivisions in the Haidian District and Xicheng District of Beijing Municipality. The results showed that more than 60% of single meals sold by takeaway food outlets were considered as healthy, and only 15% of takeaway food outlets sold healthy meals exclusively. Additionally, there were significant differences in health effects among different types of food environments, and high-risk areas of different types of food environments can be spatially identified. Compared with the counting method in the availability of food environment, the proposed new approach can depict food environment characteristics not only in the macro-scale like the counting method but also in the meal-scale. The indicators could be useful for large-scale and long-term monitoring of food environmental changes due to their simple calculation and design depending on the food delivery platform.

Water Deficit Modulates the CO2 Fertilization Effect on Plant Gas Exchange and Leaf-Level Water Use Efficiency: A Meta-Analysis

Elevated atmospheric CO2 concentrations ([eCO2]) and soil water deficits significantly influence gas exchange in plant leaves, affecting the carbon-water cycle in terrestrial ecosystems. However, it remains unclear how the soil water deficit modulates the plant CO2 fertilization effect, especially for gas exchange and leaf-level water use efficiency (WUE). Here, we synthesized a comprehensive dataset including 554 observations from 54 individual studies and quantified the responses for leaf gas exchange induced by e[CO2] under water deficit. Moreover, we investigated the contribution of plant net photosynthesis rate (P n ) and transpiration rates (T r) toward WUE in water deficit conditions and e[CO2] using graphical vector analysis (GVA). In summary, e[CO2] significantly increased P n and WUE by 11.9 and 29.3% under well-watered conditions, respectively, whereas the interaction of water deficit and e[CO2] slightly decreased P n by 8.3%. Plants grown under light in an open environment were stimulated to a greater degree compared with plants grown under a lamp in a closed environment. Meanwhile, water deficit reduced P n by 40.5 and 37.8%, while increasing WUE by 24.5 and 21.5% under ambient CO2 concentration (a[CO2]) and e[CO2], respectively. The e[CO2]-induced stimulation of WUE was attributed to the common effect of P n and T r, whereas a water deficit induced increase in WUE was linked to the decrease in T r. These results suggested that water deficit lowered the stimulation of e[CO2] induced in plants. Therefore, fumigation conditions that closely mimic field conditions and multi-factorial experiments such as water availability are needed to predict the response of plants to future climate change.

Urban and air pollution: a multi-city study of long-term effects of urban landscape patterns on air quality trends

Most air pollution research has focused on assessing the urban landscape effects of pollutants in megacities, little is known about their associations in small- to mid-sized cities. Considering that the biggest urban growth is projected to occur in these smaller-scale cities, this empirical study identifies the key urban form determinants of decadal-long fine particulate matter (PM2.5) trends in all 626 Chinese cities at the county level and above. As the first study of its kind, this study comprehensively examines the urban form effects on air quality in cities of different population sizes, at different development levels, and in different spatial-autocorrelation positions. Results demonstrate that the urban form evolution has long-term effects on PM2.5 level, but the dominant factors shift over the urbanization stages: area metrics play a role in PM2.5 trends of small-sized cities at the early urban development stage, whereas aggregation metrics determine such trends mostly in mid-sized cities. For large cities exhibiting a higher degree of urbanization, the spatial connectedness of urban patches is positively associated with long-term PM2.5 level increases. We suggest that, depending on the city's developmental stage, different aspects of the urban form should be emphasized to achieve long-term clean air goals.

Rebound of self-lubricating compound drops

Drop impact on solid surfaces is encountered in numerous natural and technological processes. Although the impact of single-phase drops has been widely explored, the impact of compound drops has received little attention. Here, we demonstrate a self-lubrication mechanism for water-in-oil compound drops impacting on a solid surface. Unexpectedly, the core water drop rebounds from the surface below a threshold impact velocity, irrespective of the substrate wettability. This is interpreted as the result of lubrication from the oil shell that prevents contact between the water core and the solid surface. We combine side and bottom view high-speed imaging to demonstrate the correlation between the water core rebound and the oil layer stability. A theoretical model is developed to explain the observed effect of compound drop geometry. This work sets the ground for precise complex drop deposition, with a strong impact on two- and three-dimensional printing technologies and liquid separation.

Changes in maternal age and prevalence of congenital anomalies during the enactment of China's universal two-child policy (2013-2017) in Zhejiang Province, China: An observational study

BACKGROUND

China implemented a partial two-child policy (2013) followed by a universal two-child policy (2015), replacing the former one-child policy mandated by the government. The changes affect many aspects of China's population as well as maternal and infant health, but their potential impact on birth defects (BDs) remains unknown. In this study, we investigated the associations of these policy changes with BDs in Zhejiang Province, China.

METHODS AND FINDINGS

We used data from the BD surveillance system in Zhejiang Province, China, which covers 90 hospitals in 30 urban districts and rural counties, capturing one-third of the total births in this province. To fully consider the time interval between conception and delivery, we defined the one-child policy period as data from 2013 (births from October 2012 to September 2013), the partial two-child policy period as data from 2015 (births from October 2014 to September 2015), and the universal two-child policy period as data from 2017 (births from October 2016 to September 2017). Data from 2009 and 2011 were also used to show the changes in the proportion of births to women with advanced maternal age (35 years and older) prior to the policy changes. Main outcome measures were changes in the proportion of mothers with advanced maternal age, prevalence of BDs, rankings of BD subtypes by prevalence, prenatal diagnosis rate, and live birth rate of BDs over time. A total of 1,260,684 births (including live births, early fetal losses, stillbirths, and early neonatal deaths) were included in the analyses. Of these, 644,973 (51.16%) births were to women from urban areas, and 615,711 (48.84%) births were to women from rural areas. In total, 135,543 (10.75%) births were to women with advanced maternal age. The proportion increased by 85.68%, from 8.52% in 2013 to 15.82% in 2017. However, it had remained stable prior to policy changes. Overall, 23,095 BDs were identified over the policy changes (2013-2017). The prevalence of BDs during 2013, 2015, and 2017 was 245.95, 264.86, and 304.36 per 10,000 births, respectively. Trisomy 21 and other chromosomal defects increased in both risk and ranking from 2013 to 2017 (crude odds ratio [95% confidence interval] 2.13 [1.75-2.60], from ranking 10th to 5th, and 3.63 [2.84-4.69], from ranking 16th to 6th, respectively). The prenatal diagnosis rate increased by 3.63 (2.2-5.1) percentage points (P < 0.001), from 31.10% to 34.72%, and identification of BDs occurred 1.88 (1.81-1.95) weeks earlier (P < 0.001). The live birth rate for infants with BDs born before 28 gestational weeks increased from 1.29% to 11.45%. The major limitations of this observational study include an inability to establish causality and the possible existence of unknown confounding factors, some of which could contribute to BDs.

CONCLUSIONS

In this study, we observed significant increases in maternal age and the prevalence of total and age-related anomalies following China's new two-child policy. Increases in live birth rate for infants with BDs born before 28 gestational weeks suggest that healthcare for very preterm births with BDs may be warranted in the future, as well as updating the definition of perinatal period.

Cohort profile: the Lanxi Cohort study on obesity and obesity-related non-communicable diseases in China

PURPOSE

The Lanxi Cohort was established to systematically investigate the aetiology and interplay of body fat distribution and multiple factors with obesity and obesity-related non-communicable diseases in China.

PARTICIPANTS

The baseline investigation of the Lanxi Cohort study took place between June 2015 and August 2017 in Lanxi, Zhejiang Province, China. Permanent residents from one urban community and four rural villages were involved in this study. The baseline investigation included questionnaire survey, physical examination, dual-energy X-ray absorptiometry (DXA) scan, blood samples collection and traditional Chinese medicine (TCM) inquiry.

FINDINGS TO DATA

A total of 5132 participants, aged 18 to 80 years, were recruited at baseline; among them, 38.7% were men and 64.8% were from the urban area. The mean age was 53.04±12.77 years. The completion rates of physical examination, DXA scan, blood collection and TCM inquiry were 99.9%, 98.5%, 99.9% and 96.5%, respectively. The mean body mass index (BMI) was 23.42±3.20 kg/m² with 8.1% of the study population being obese (BMI ≥28 kg/m²). The crude prevalence of hypertension, diabetes and metabolic syndrome were 34.9%, 10.0% and 30.4%, respectively.

FUTURE PLANS

All participants will be monitored annually for cause-specific mortality and morbidity and hospital admission and will be followed up by in-person survey every 4 years. The baseline population is considered to expand in the future depending on the availability of funding support.

ETHICS APPROVAL

This study was approved by the Ethical Committee of the School of Public Health, Zhejiang University.

Associations of nicotine dependence and fat distribution in Chinese male adults: a cross-sectional study in Lanxi, China

INTRODUCTION

Previous studies have showed association between smoking and central fat distribution. However, the impact of smoking on whole body fat distribution, particularly peripheral fat distribution remains unclear.

METHODS

Nicotine dependence was assessed in a total of 1264 male adults aged 18-80 years using the Fagerström Test for Nicotine Dependence (FTND). Smoking status was categorised as non-smokers, former and current smokers with very low, low/moderate, or high FTND scores. Body fat distribution was determined using the dual energy X-ray absorptiometry and anthropometric measurements. Multivariable linear regression models were applied to examine the adjusted associations between body fat distribution and smoking in all participants, and its association with FTND scores in the current smokers.

RESULTS

Greater waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), trunk fat percentage (%TF), android fat percentage (%AF) and android-to-gynoid fat mass ratio (AOI); but lower legs fat percentage (%LegF), limb fat percentage (%LimbF) and gynoid fat percentage (%GF) were found in current smokers with high FTND scores compared with non-smokers. In current smokers aged 60 years or older, FTND scores had positive associations with WC, WHR, WHtR, %TF, %AF and AOI, and negative associations with %LegF, %LimbF and %GF.

CONCLUSIONS

Nicotine dependence was positively associated with central fat distribution and negatively associated with peripheral fat distribution in Chinese male adults, particularly in those older or heavy smokers, and these associations were independent from body mass index, which might be due to long exposure to smoking.

The interplay of climate, intervention and imported cases as determinants of the 2014 dengue outbreak in Guangzhou

Dengue is a fast spreading mosquito-borne disease that affects more than half of the population worldwide. An unprecedented outbreak happened in Guangzhou, China in 2014, which contributed 52 percent of all dengue cases that occurred in mainland China between 1990 and 2015. Our previous analysis, based on a deterministic model, concluded that the early timing of the first imported case that triggered local transmission and the excessive rainfall thereafter were the most important determinants of the large final epidemic size in 2014. However, the deterministic model did not allow us to explore the driving force of the early local transmission. Here, we expand the model to include stochastic elements and calculate the successful invasion rate of cases that entered Guangzhou at different times under different climate and intervention scenarios. The conclusion is that the higher number of imported cases in May and June was responsible for the early outbreak instead of climate. Although the excessive rainfall in 2014 did increase the success rate, this effect was offset by the low initial water level caused by interventions in late 2013. The success rate is strongly dependent on mosquito abundance during the recovery period of the imported case, since the first step of a successful invasion is infecting at least one local mosquito. The average final epidemic size of successful invasion decreases exponentially with introduction time, which means if an imported case in early summer initiates the infection process, the final number infected can be extremely large. Therefore, dengue outbreaks occurring in Thailand, Singapore, Malaysia and Vietnam in early summer merit greater attention, since the travel volumes between Guangzhou and these countries are large. As the climate changes, destroying mosquito breeding sites in Guangzhou can mitigate the detrimental effects of the probable increase in rainfall in spring and summer.

An unprecedented dengue outbreak occurred in Guangzhou, 2014, with 38,036 reported cases in contrast to 73,179 cases in all of mainland China from 1990 to 2015. In an earlier analysis using a deterministic model, we concluded the early timing of local transmission to be the most important determinant of this outbreak. Here we use a stochastic model to explore the reasons why the outbreak happened earlier in 2014. Our results identified the higher number of imported cases in May and June to be the most probable explanation. Based on the investigation of the determinants of success rate and final epidemic size, this work provides suggestions for reducing dengue outbreak potential and epidemic size in the future. More attention should be paid to imported case detection and vector control measures in early summer, because this is the time when successful invasion can result in high incidence of infection and the success rate of each imported case begins to rise. Destroying mosquito breeding sites can reduce the maximum water level of the system and attenuate the role played by climate. In addition, interventions within 10 days after the introduction of imported cases is still effective in preventing further transmission.