Ultra-low Concentration of Cellulose Nanofibers (CNFs) for Enhanced Nucleation and Yield of ZnO Nanoparticles.

Cellulose nanofibers (CNFs) were used in aqueous synthesis protocols for zinc oxide (ZnO) to affect the formation of the ZnO particles. Different concentrations of CNFs were evaluated in two different synthesis protocols producing distinctly different ZnO morphologies (flowers and sea urchins) as either dominantly oxygen- or zinc-terminated particles. The CNF effects on the ZnO formation were investigated by implementing a heat-treatment method at 400 °C that fully removed the cellulose material without affecting the ZnO particles made in the presence of CNFs. The inorganic phase formations were monitored by extracting samples during the enforced precipitations to observe changes in the ZnO morphologies. A decrease in the size of the ZnO particles could be observed for all synthesis protocols, already occurring at small additions of CNFs. At as low as 0.1 g/L CNFs, the particle size decreased by 50% for the flower-shaped particles and 45% for the sea-urchin-shaped particles. The formation of smaller particles was accompanied by increased yield by 13 and 15% due to the CNFs' ability to enhance the nucleation, resulting in greater mass of ZnO divided among a larger number of particles. The enhanced nucleation could also be verified as useful for preventing secondary morphologies from forming, which grew on the firstly precipitated particles. The suppression of secondary growths' was due to the more rapid inorganic phase formation during the early phases of the reactions and the faster consumption of dissolved salts, leaving smaller amounts of metal salts present at later stages of the reactions. The findings show that using cellulose to guide inorganic nanoparticle growth can be predicted as an emerging field in the preparation of functional inorganic micro/nanoparticles. The observations are highly relevant in any industrial setting for the large-scale and resource-efficient production of ZnO.

Screening, cloning, enzymatic properties of a novel thermostable cellulase enzyme, and its potential application on water hyacinth utilization.

Cellulose is the cheapest, natural, renewable organic substance that is used as a carbon source in various fields. Water hyacinth, an aquatic plant rich in cellulose, is often used as a raw material in fuel production. However, natural cellulase can be hardly used in industrial production on account of its low thermal stability and activity. In this study, a metagenomic library was constructed. Then, a new cellulase gene, cel1029, was screened by Congo red staining and expressed in the prokaryotic system. Enzymatic properties of Cel1029 were explored, including optimum temperature and pH, thermal and pH stability, and tolerance against organic solvents, metal ions, and salt solutions. Finally, its ability of degrading water hyacinth was identified and evaluated. Cel1029 displayed high homology with endoglucanase in the glycoside hydrolase family 5 (GH5) and had high stability across a broad temperature range. More than 86% of its enzymatic activities were retained between 4 and 60 °C after 24 h of incubation. Single-factor analysis and orthogonal design were further conducted to determine the optimal conditions for the highest reducing sugar yield of water hyacinth. Interestingly, Cel1029 efficiently transformed water hyacinth with a reducing sugar yield of 430.39 mg/g in 22 h. These findings may open the door for significant industrial applications of a novel GH5 cellulase (NCBI Reference Sequence: MK051001, Cel1029) and help identify more efficient methods to degrade cellulose-rich plants.

Regional-level risk factors for severe hand-foot-and-mouth disease: an ecological study from mainland China.

BACKGROUND: Severe hand-foot-and-mouth disease (HFMD) is a life-threatening contagious disease among young children and infants. Although enterovirus A71 has been well acknowledged to be the dominant cause of severe HFMD, there still remain other unidentified risk factors for severe HFMD. Previous studies mainly focused on identifying the individual-level risk factors from a clinical perspective, while rare studies aimed to clarify the association between regional-level risk factors and severe HFMD, which may be more important from a public health perspective. METHODS: We retrieved the clinical HFMD counts between 2008 and 2014 from the Chinese Center for Disease Control and Prevention, which were used to calculated the case-severity rate in 143 prefectural-level cities in mainland China. For each of those 143 cities, we further obtained city-specific characteristics from the China City Statistical Yearbook (social and economic variables) and the national meteorological monitoring system (meteorological variables). A Poisson regression model was then used to estimate the associations between city-specific characteristics (reduced by the principal component analysis to avoid multicollinearity) and the case-severity rate of HFMD. The above analysis was further stratified by age and gender to examine potential modifying effects and vulnerable sub-populations. RESULTS: We found that the case-severity rate of HFMD varied dramatically between cities, ranging from 0 to 8.09%. Cities with high case-severity rates were mainly clustered in Central China. By relating the case-severity rate to city-specific characteristics, we found that both the principal component characterized by a high level of social and economic development (RR = 0.823, 95%CI 0.739, 0.916) and another that characterized by warm and humid climate (RR = 0.771, 95%CI 0.619, 0.960) were negatively associated with the case-severity rate of HFMD. These estimations were consistent across age and gender sub-populations. CONCLUSION: Except for the type of infected pathogen, the case-severity rate of HFMD was closely related to city development and meteorological factor. These findings suggest that social and environmental factors may also play an important role in the progress of severe HFMD.

Self-powered portable melt electrospinning for in situ wound dressing.

BACKGROUND: Electrospun (e-spun) nanofibers for wound dressing have attracted wide attention due to its large specific surface area, large porosity and breathability. Compared with solution electrospinning (e-spinning), melt e-spinning is more bio-friendly without toxic solvent participation, which provides the possibility of in situ e-spinning on wounds directly. However, previously reported melt e-spinning devices were usually bulky and cumbersome due to their necessary heating unit, and different components were separated to avoid electrostatic interference. RESULTS: In this article, we report on a self-powered hand-held melt e-spinning gun which can work without any external power supply (outdoors). The problem of electrostatic interference for this integrated device was solved by using a special high heat transfer insulation unit. The apparatus is easy and safe to operate by a single hand due to its small volume (24 × 6 × 13 cm3) and light weight (about 450 g). Some biodegradable polymers, for example, polycaprolactone (PCL) fibers were successful e-spun onto wounds directly by using this dressing gun. CONCLUSIONS: PCL fibrous membrane has good biocompatibility and can be in situ electrospun to wound surface as a wound dressing by the portable melt e-spinning gun. Besides wound dressing, this hand-held melt e-spinning gun may be used in 3D printing and experimental teaching demonstration aids.

Short-term effects of rainfall on childhood hand, foot and mouth disease and related spatial heterogeneity: evidence from 143 cities in mainland China.

BACKGROUND: Numerous studies have demonstrated the potential association between rainfall and hand, foot and mouth disease (HFMD), but the results are inconsistent. This study aimed to quantify the relationship between rainfall and HFMD based on a multicity study and explore the potential sources of spatial heterogeneity. METHODS: We retrieved the daily counts of childhood HFMD and the meteorological variables of the 143 cities in mainland China between 2009 and 2014. A common time series regression model was applied to quantify the association between rainfall and HFMD for each of the 143 cities. Then, we adopted the meta-regression model to pool the city-specific estimates and explore the sources of heterogeneity by incorporating city-specific characteristics. RESULTS: The overall pooled estimation suggested a nonlinear exposure-response relationship between rainfall and HFMD. Once rainfall exceeded 15 mm, the HFMD risk stopped increasing linearly and began to plateau with the excessive risk ratio (ERR) peaking at 21 mm of rainfall (ERR = 3.46, 95% CI: 2.05, 4.88). We also found significant heterogeneity in the rainfall-HFMD relationships (I2 = 52.75%, P < 0.001). By incorporating the city-specific characteristics into the meta-regression model, temperature and student density can explain a substantial proportion of spatial heterogeneity with I2 statistics that decreased by 5.29 and 6.80% at most, respectively. CONCLUSIONS: Our findings verified the nonlinear association between rainfall and HFMD. The rainfall-HFMD relationship also varies depending on locations. Therefore, the estimation of the rain-HFMD relationship of one location should not be generalized to another location.

Comparisons between mild and severe cases of hand, foot and mouth disease in temporal trends: a comparative time series study from mainland China.

BACKGROUND: Over recent decades, hand, foot and mouth disease (HFMD) has emerged as a serious public health threat in the Asia-Pacific region because of its high rates of severe complications. Understanding the differences and similarities between mild and severe cases can be helpful in the control of HFMD. In this study, we compared the two types of HFMD cases in their temporal trends. METHODS: We retrieved the daily series of disease counts of mild and severe HFMD cases reported in mainland China in the period of 2009-2014. We applied a quasi-Poisson regression model to decompose each series into the long-term linear trend, periodic variations, and short-term fluctuations, and then we compared each component between two series separately. RESULTS: A total of 11,101,860 clinical HFMD cases together with 115,596 severe cases were included into this analysis. We found a biennial increase of 24.46 % (95 % CI: 22.80-26.14 %) for the baseline of disease incidence of mild cases, whereas a biennial decrease of 8.80 % (95 % CI: 7.26-10.31 %) was seen for that of severe cases. The periodic variations of both two series could be characterized by a mixture of biennial, annual, semi-annual and eight-monthly cycles. However, compared to the mild cases, we found the severe cases vary more widely for the biennial and annual cycle, and started its annual epidemic earlier. We also found the short-term fluctuations between two series were still significantly correlated at the current day with a correlation coefficient of 0.46 (95 % CI: 0.43-0.49). CONCLUSIONS: We found some noticeable differences and also similarities between the daily series of mild and severe HFMD cases at different time scales. Our findings can help us to deepen the understanding of the transmission of different types of HFMD cases, and also provide evidences for the planning of the associated disease control strategies.

[Abundances and Morphology Patterns of Microplastics Under Different Land Use Types on the Loess Plateau].

As an emerging pollutant to the environment, microplastics have received widespread attention worldwide. The Loess Plateau, as one of the major agricultural production areas in China, has various land use types, but how the abundance and morphological patterns of microplastics differ among soils under different land use types remains unclear. In this study, we collected soils from three different land use types:croplands, apple orchards, and landfills in the Wangdonggou Catchment. Microplastics were separated and extracted using a modified density centrifugation method, and the abundance, composition, and morphological characteristics of the soil were analyzed and characterized using a laser infrared imaging system. The results showed that the average abundance of microplastics in the Wangdonggou Catchment was 4715 n·kg-1, mainly composed of PET, PU, and alkyd varnish(ALK), respectively accounting for 30.39%, 29.58%, and 8.42%. More than 80% of the microplastics were fragmented, and more than 60% of the microplastics were of a size ≤ 50 µm. The average abundance of microplastics varied significantly among land use types:cropland soil (7550 n·kg-1)>apple orchard soil (3440 n·kg-1)>landfill soil (2283 n·kg-1). The average area, width, height, eccentricity, circularity, and other morphological characteristics of microplastics in apple orchard soil were significantly different from those in the cropland and landfill soil.

Introduction to biodegradable polylactic acid ureteral stent application for treatment of ureteral war injury.

OBJECTIVE: • To study the operability and effectiveness of a biodegradable ureteral stent for clinical treatment of ureteral war injury using a canine model. MATERIALS AND METHODS: • A device was designed and employed to generate firearm fragment wounds in unilateral ureters (on randomly chosen sides) of nine beagles (Group A). The wounded ureters were then debrided and sutured. • Intravenous pyelography (IVP) and radioactive renography were performed 40, 80 and 120 days postoperatively. In Group B, firearm fragment wounds were made to the bilateral ureters in nine beagles. A polylactic acid stent was placed unilaterally (on a randomly chosen side) whereas the ureter on the other side was debrided and sutured without stenting. • Both IVP and radioactive renography were performed 40, 80 and 120 days postoperatively. The operability and effectiveness of the biodegradable ureteral stent were studied thereafter. RESULTS: • In Group A, hydronephrosis and hydroureter occurred and worsened postoperatively on the wounded sides in all nine beagles. The ratio of the renal partial concentration indices (RPCI) between the kidneys (unwounded side : wounded side) increased. • The ratio of the kidney washout half-time between the kidneys (unwounded side : wounded side) decreased. In Group B, neither hydronephrosis nor hydroureter was found postoperatively in the stented ureters but both occurred in the unstented ureters in all nine beagles. • The ratio of RPCI between kidneys (stented side : unstented side) increased whereas the kidney washout half-time ratio between the stented and unstented sides decreased. Differences were significant. CONCLUSION: • In Group A, the new canine model for firearm fragment wounds was tested and proved to be operable and effective. In Group B, hydronephrosis and hydroureter were effectively prevented in ureters by biodegradable stent placement compared with the non-stented ureters where hydronephrosis and hydroureter occurred. The renal concentration capacity was effectively protected and the half-time of kidney washout was shortened.

Controlling the Poly(ε-caprolactone) Degradation to Maintain the Stemness and Function of Adipose-Derived Mesenchymal Stem Cells in Vascular Regeneration Application.

Biodegradable poly(ε-caprolactone) (PCL) scaffolds with adipose-derived mesenchymal stem cells (ADSCs) have been used in vascular regeneration studies. An evaluation method of the effect of PCL degradation products (DP) on the viability, stemness, and differentiation capacities of ADSCs is established. ADSCs are cultured in medium containing different concentrations of PCL DP before evaluating the effect of PCL DP on the cell apoptosis and proliferation, cell surface antigens, adipogenic and osteogenic differentiation capacities, and capacities to differentiate into endothelial cells and smooth muscle cells. The results demonstrate that PCL DP exceed 0.05 mg mL-1 may change the stemness and differentiation capacities of ADSCs. Therefore, to control the proper concentration of PCL DP is essential for ADSCs in vascular regeneration application.

Challenges of Misdiagnosis and Suboptimal Treatment of Persistent Idiopathic Facial Pain and Atypical Odontalgia: A Retrospective Multi-Centric Cross-Sectional Investigation.

PURPOSE: To explore the challenges faced in the diagnosis and treatment of atypical odontalgia (AO) and other persistent idiopathic facial pain (PIFP). PATIENTS AND METHODS: This retrospective multi-centric cross-sectional study utilized clinical information (eg, clinical manifestations, history of consultations and treatments prior to correct diagnoses) from patients' medical records. Their economic parameters were also extracted from medical insurance databases. Each variable collected was statistically analyzed. Differences of variables between AO and other PIFP were statistically tested. RESULTS: A total of 394 patients were included in this study. On average, the diagnostic delay was 34.8±14.2 months, a median of 7 consultations were performed prior to a correct diagnosis, and 5 ineffective prescriptions were issued. Patients with AO suffered from longer diagnostic delays than patients with other PIFP (38.4±14.3 months vs 31.6±13.4 months) and were more likely to receive invasive dental treatments (73.3% vs 4.3%). The median total cost of treatment for a single patient before correct diagnosis was 8506.3 yuan. Patients with AO spent more than patients with other PIFP (10,146.5 Yuan vs 3864.0 Yuan). CONCLUSION: Patients with PIFP were frequently misdiagnosed and the length of diagnostic delay was observed to be long. Ineffective medications, unwarranted procedures, and unnecessary economic burden were imposed on the patients. Patients with AO are in a worse situation than patients with other PIFP. As significantly urgent and unsatisfactory results of misdiagnosis of PIFP have been reported in our study, more attention should be paid on the research and education in this field.

An alternative comprehensive index to quantify the interactive effect of temperature and relative humidity on hand, foot and mouth disease: A two-stage time series study including 143 cities in mainland China.

BACKGROUND: Comprehensive indices have been used to quantify the interactive effect of temperature and humidity on hand, foot and mouth disease (HFMD). The majority of them reflect how weather feels to humans. In this study, we propose an alternative index aiming to reflect the impacts of weather on HFMD and compare its performance with that of previous indices. METHODS: We proposed an index defined as the product of temperature and a weight parameter raised to the rescaled relative humidity, denoted by THIa. We then compared its model fit and heterogeneity with those of previous indices (including the humidex, heat index and temperature) by a multicity two-stage time series analysis. We first built a common distributed lag nonlinear model to estimate the associations between different indices and HFMD for each city separately. We then pooled the city-specific estimates and compared the average model fit (measured by the QAIC) and heterogeneity (measured by I2) among the different indices. RESULTS: We included the time series of HFMD and meteorological variables from 143 cities in mainland China from 2009 to 2014. By varying the weight parameter of THIa, the results suggested that 100% relative humidity can amplify the effects of temperature on HFMD 1.6-fold compared to 50% relative humidity. By comparing different candidate indices, THIa performed the best in terms of the average of the model fits (QAIC = 9449.37), followed by humidex, heat index and temperature. In addition, the estimated exposure-response curves between THIa and HFMD were consistent across climate regions with minimum heterogeneity (I2 = 65.90), whereas the others varied across climate regions. CONCLUSIONS: This study proposed an alternative comprehensive index to characterize the interactive effects of temperature and humidity on HFMD. In addition, the results also imply that previous human-based indices might not be sufficient to reflect the complicated associations between weather and HFMD.

The temporal characteristics of the lag-response relationship and related key time points between ambient temperature and hand, foot and mouth disease: A multicity study from mainland China.

BACKGROUND: Previous studies have thoroughly elucidated the exposure-response relationship between ambient temperature and hand, foot, and mouth disease (HFMD), whereas very little concern has been to the lag-response relationship and related key time points. OBJECTIVES: We aimed to clarify the temporal characteristics of the lag-response relationship between ambient temperature and HFMD and how they may vary spatially. METHODS: We retrieved the daily time series of meteorological variables and HFMD counts for 143 cities in mainland China between 2009 and 2014. We estimated the city-specific lag-response curve between ambient temperature and HFMD and related key time points by applying common distributed lag nonlinear models (DLNM) and Monte Carlo simulation methods. Then, we pooled the city-specific estimates by performing a meta-regression with the city-specific characteristics as meta-predictors to explain the potential spatial heterogeneity. RESULTS: We found a robust lag pattern between temperature and HFMD for different levels of temperatures. The temporal change of risk obtained its maximum value on the current day but dropped sharply thereafter and then rebounded to a secondary peak, which implied the presence of a harvesting effect. By contrast, the estimation of key time points showed substantial heterogeneity, especially at high temperature (the I2 statistics ranged from 47% to 80%). With one unit increase in the geographic index, the secondary peak would arrive 0.37 (0.02, 0.71) days later. With one unit increase in the economic index and climatic index, the duration time of the lag-response curve would be lengthened by 0.36 (0.1, 0.62) and 0.92 (0.54, 1.29) days, respectively. CONCLUSION: Our study examined the lag pattern and spatial heterogeneity of the lag-response relationship between temperature and HFMD. Those findings gave us new insights into the complex association and the related mechanisms between weather and HFMD and important information for weather-based disease early warning systems.

Epidemiology of Hand, Foot, and Mouth Disease Before and After the Introduction of Enterovirus 71 Vaccines in Chengdu, China, 2009-2018.

BACKGROUND: Hand, foot, and mouth disease (HFMD) has posed a serious threat to children's health. Three inactivated monovalent enterovirus 71 (EV71) vaccines are proved to be highly efficacious in phase III clinical trials and are now available in China. METHODS: We analyzed the citywide surveillance data on HFMD cases in Chengdu during 2009-2018, and estimated cumulative first-dose EV71 vaccination coverage among children eligible to EV71 vaccination after August 2016 in Chengdu. Time series susceptible-infected-recovered model was developed to analyze basic reproduction number and herd immunity threshold of HFMD. Overall and serotype-specific HFMD incidences and severity risks were compared before and after the EV71 vaccination. RESULTS: Among 3 laboratory-identified serotype categories, i.e. EV71, coxsackievirus A16 (CV-A16), and other enteroviruses, the major serotype attributed to HFMD has been changing across years. The cumulative first-dose EV71 vaccination coverage rate was estimated as 60.8% during the study period in Chengdu. By contrast, herd immunity threshold for EV71-related HFMD was 94.0%. After introduction of EV71 vaccines, the overall incidence of HFMD increased 60.8%, mainly driven by 173.7% and 11.8% increased in HFMD caused by other enteroviruses and CV-A16, respectively, which offset a significant reduction in the incidence of HFMD caused by EV71. The overall case-severity risk decreased from 1.4% to 0.3%, with significantly declined presented in all serotype categories. CONCLUSIONS: The incidence and severity of EV71-related HFMD decreased following implementation of EV71 vaccination. Developing multivalent vaccines and strengthening laboratory-based surveillance could further decline burden of HFMD.

The spatial heterogeneity of the associations between relative humidity and pediatric hand, foot and mouth disease: Evidence from a nation-wide multicity study from mainland China.

BACKGROUND: Hand, foot, and mouth disease (HFMD) remains a serious health threat to young children in East and Southeast Asia. The humidity is crucial for the survival of enterovirus, but the evidence of the humidity-HFMD association is inconsistent. In this study we investigated the spatial heterogeneity of humidity-HFMD associations and related effect modifiers. METHODS: We retrieved the daily surveillance data of childhood HFMD counts and meteorological variables from 143 cities in mainland China between 2009 and 2014 and then adopted a three-stage time series analysis. We first fitted a common distributed lag nonlinear model (DLNM) for each of the 143 cities separately to obtain the city-specific estimates of humidity-HFMD association. Then, we pooled the city-specific estimates through multivariate meta-regression with city-level characteristics as potential effect modifiers to study the reasons for heterogeneity. Finally, we applied a region-specific analysis to verify our findings and to better visualize our results. RESULTS: We found that the overall pooled humidity-HFMD relationship was shown as an approximately U-shaped curve with substantial spatial heterogeneity (I2 = 77.8%). Taking the reference relative humidity as 70%, the minimum relative risk (RR) was obtained at 45% with a value of 0.83 (0.79, 0.87), while the maximum RR was found to be at both 20% and over 85% separately with a value of 1.10 (1.05, 1.15). The spatial heterogeneity can be well explained by the climatic, social characteristics and terrains among cities. The modification effects can be roughly classified into two types, including change in the overall slope and the shape of the curve. CONCLUSIONS: Due to substantial spatial heterogeneity, caution should be taken when interpreting the weather-HFMD association in a single-site study and to avoid generalizing its findings to another site. Our study also implied the existence of interactions among meteorological factors given that climatic factors can modify the weather-HFMD association.

The modification effect of the diurnal temperature range on the exposure-response relationship between temperature and pediatric hand, foot and mouth disease.

BACKGROUND: Growing evidence suggests that the diurnal temperature range (DTR) could modify the temperature-disease relationship for those environmentally-related infectious diseases. However, there is a lack of evidence on the hand, foot and mouth disease (HFMD). In this study, we thoroughly examined this hypothesis via a nationwide study. METHOD: We collected the daily time series of HFMD cases and meteorological factors of 143 cities in mainland China from 2009 to 2014. For each city, we calculated the arithmetic average of the meteorological factors as a proxy for the climatic differences. We then performed two-stage time series analyses for four different climatic regions. Specifically, a distributed lag nonlinear model was applied to estimate the temperature-HFMD relationship for each city, and then a multivariate meta-regression was implemented to examine whether the DTR could explain the potential heterogeneity as an effect modifier. In addition, we compared the modification effect of the DTR with those of other climatic factors. RESULT: We found a significant modification effect of DTR on the temperature-HFMD relationship in the moderate-temperature region. Besides, the modification effect was only observed at hot temperatures. Comparing the maximum temperature (32.2 °C) to the median temperature (11.9 °C), the risk ratio was 1.60 (1.33, 1.92) when DTR was in the 10th percentile (6.8 °C) and 0.81 (0.69, 0.96) when the DTR was in the 90th percentile (11.8 °C). By comparing DTR with other climatic variables, we found that the DTR had the best performance in improving the model fit (ΔQAIC= 10.1) and reducing the heterogeneity (ΔI2 = 3.1%) in the multivariate meta-regression. CONCLUSION: Our findings verified that DTR can modify the temperature-HFMD relationship. Besides, our findings also implied that DTR could be used as a proxy variable to comprehensively reflect the modification effects of multiple climatic factors.

In situ melt electrospun polycaprolactone/Fe3O4 nanofibers for magnetic hyperthermia.

Magnetic fibrous membrane used to generate heat under the alternating magnetic field (AMF) has attracted wide attention due to their application in magnetic hyperthermia. However, there is not magnetic fibrous membrane prepared by melt electrospinning (e-spinning) which is a solvent-free, bio-friendly technology. In this work, polycaprolactone (PCL)/Fe3O4 fiber membrane was prepared by melt e-spinning and using homemade self-powered portable melt e-spinning apparatus. The hand-held melt e-spinning apparatus has a weight of about 450 g and a precise size of 24 cm in length, 6 cm in thickness and 13 cm in height, which is more portable for widely using in the medical field. The PCL/Fe3O4 composite fibers with diameters of 4-17 µm, are very uniform. In addition, the magnetic composite fiber membrane has excellent heating efficiency and thermal cycling characteristics. The results indicated that self-powered portable melt e-spinning apparatus and PCL/Fe3O4 fiber membrane may provide an attractive way for hyperthermia therapy.

Wireless piezoelectric devices based on electrospun PVDF/BaTiO3 NW nanocomposite fibers for human motion monitoring.

Real-time personalized motion monitoring and analysis are important for human health. Thus, to satisfy the needs in this area and the ever-increasing demand for wearable electronics, we design and develop a wireless piezoelectric device consisting of a piezoelectric pressure sensor based on electrospun PVDF/BaTiO3 nanowire (NW) nanocomposite fibers and a wireless circuit system integrated with a data conversion control module, a signal acquisition and amplification module, and a Bluetooth module. Finally, real-time piezoelectric signals of human motion can be displayed by an App on an Android mobile phone for wireless monitoring and analysis. This wireless piezoelectric device is proven to be sensitive to human motion such as squatting up and down, walking, and running. The results indicate that our wireless piezoelectric device has potential applications in wearable medical electronics, particularly in the fields of rehabilitation and sports medicine.

The exposure-response relationship between temperature and childhood hand, foot and mouth disease: A multicity study from mainland China.

BACKGROUND: Hand, foot and mouth disease (HFMD) is a rising public health issue in the Asia-Pacific region. Numerous studies have tried to quantify the relationship between meteorological variables and HFMD but with inconsistent results, in particular for temperature. We aimed to characterize the relationship between temperature and HFMD in various locations and to investigate the potential heterogeneity. METHODS: We retrieved the daily series of childhood HFMD counts (aged 0-12 years) and meteorological variables for each of 143 cities in mainland China in the period 2009-2014. We fitted a common distributed lag nonlinear model allowing for over dispersion to each of the cities to obtain the city-specific estimates of temperature-HFMD relationship. Then we pooled the city-specific estimates through multivariate meta-regression with city-level characteristics as potential effect modifiers. RESULTS: We found that the overall pooled temperature-HFMD relationship was shown as an approximately inverted V shape curve, peaking at the 91th percentile of temperature with a risk ratio of 1.30 (95% CI: 1.23-1.37) compared to its 50th percentile. We found that 68.5% of the variations of city-specific estimates was attributable to heterogeneity. We identified rainfall and altitude as the two main effect modifiers. CONCLUSIONS: We found a nonlinear relationship between temperature and HFMD. The temperature-HFMD relationship varies depending on geographic and climatic conditions. The findings can help us deepen the understanding of weather-HFMD relationship and provide evidences for related public health decisions.

Tissue engineering of ureteral grafts by seeding urothelial differentiated hADSCs onto biodegradable ureteral scaffolds.

The study is aimed to evaluate the differentiation potential of human adipose-derived stem cells (hADSCs) into urothelial lineage, and to assess possibility of constructing ureteral grafts using the differentiated hADSCs and a novel polylactic acid (PLA)/collagen scaffolds. HADSCs were indirectly cocultured with urothelial cells in a transwell coculture system for urothelial differentiation. After 14 days coculturing, differentiation was evaluated by detecting urothelial lineage markers (cytokeratin-18 and uroplakin 2) in mRNA and protein level. Then the differentiated hADSCs were seeded onto PLA/collagen ureteral scaffolds and cultured in vitro for 1 week. The biocompatibility of the scaffolds was tested by scanning electron microscopy (SEM) and MTT analysis. At last, the cell/scafflod grafts were subcutaneously implanted into 4-week-old female athymic mice for 14 days. The results demonstrated that the hADSCs could be efficiently induced into urothelial lineage by indirect coculture. The differentiated cells seeded onto the PLA/collagen ureteral scaffolds survived up to 7 days and maintained proliferation in vitro, which indicated that the scaffolds displayed good biocompatibility. In vivo study showed that the differentiated cells in the grafts survived, formed multiple layers on the scaffolds and expressed urothelial lineage markers. In conclusion, hADSCs may serve as an alternative cell resource in cell-based tissue engineering for ureteral reconstruction. These cells could be employed to construct a model of ureteral engineering grafts and be effectively applied in vivo, which could be a new strategy on ureteral replacement with applicable potential in clinical research.

A surface-modified biodegradable urethral scaffold seeded with urethral epithelial cells.

BACKGROUND: Efficient cell adhesion and proliferation is a central issue in cell-based tissue engineering, which offers great promise for repair of urethral defects or strictures. This study evaluated the adhesion and growth of rabbit uroepithelium on a surface-modified three-dimensional poly-L-lactic acid (PLLA) scaffold. METHODS: Urethral mucosa were harvested from male New Zealand rabbits and the urothelium were dissociated and then cultured. Immunocytochemistry on cultured uroepithelium for pancytokeratin and uroplakin II and TE-7 confirmed pure populations. After in vitro proliferation, cells were seeded onto a surface-modified urethral scaffold with non-knitted filaments. The morphology and viability of the cells were examined by immunohistochemical and fluorescence staining. Inverted and scanning microscopes were used to document cell growth and adhesion. RESULTS: Three to five days after primary culture, the uroepithelial cells gradually became confluent, assuming a cobblestone pattern. The filaments of the urethral scaffold had excellent biocompatibility and allowed growth of the uroepithelium, without affecting viability. The uroepithelial cells adhered to and grew well on the scaffold. After 3 - 7 days, the cells grew vigorously and meshes of the scaffold were full of uroepitheliums. CONCLUSIONS: The surface-modified urethral scaffold with non-knitted filaments allows the growth of uroepithelium and can serve as a carrier for the tissue engineering of urethra.