MoS2 Hollow Multishelled Nanospheres Doped Fe Single Atoms Capable of Fast Phase Transformation for Fast-charging Na-ion Batteries.

Low Na+ and electron diffusion kinetics severely restrain the rate capability of MoS2 as anode for sodium-ion batteries (SIBs). Slow phase transitions between 2H and 1T, and from NaxMoS2 to Mo and Na2S as well as the volume change during cycling, induce a poor cycling stability. Herein, an original Fe single atom doped MoS2 hollow multishelled structure (HoMS) is designed for the first time to address the above challenges. The Fe single atom in MoS2 promotes the electron transfer, companying with shortened charge diffusion path from unique HoMS, thereby achieving excellent rate capability. The strong adsorption with Na+ and self-catalysis of Fe single atom facilitates the reversible conversion between 2H and 1T, and from NaxMoS2 to Mo and Na2S. Moreover, the buffering effect of HoMS on volume change during cycling improves the cyclic stability. Consequently, the Fe single atom doped MoS2 quadruple-shelled sphere exhibits a high specific capacity of 213.3 mAh g-1 at an ultrahigh current density of 30 A g-1, which is superior to previously-reported results. Even at 5 A g-1, 259.4 mAh g-1 (83.68 %) was reserved after 500 cycles. Such elaborate catalytic site decorated HoMS is also promising to realize other "fast-charging" high-energy-density rechargeable batteries.

Reversible Transformation and Distribution Determination of Diverse Pt Single-Atom Species.

In single-atom catalysts (SACs), the complexity of the support anchoring sites creates a vast diversity of single-atom species with varied coordination environments. To date, the quantitative distribution of these diverse single-atom species in a given SAC has remained elusive. Recently, CeO2-supported metal SACs have been extensively studied by modulating their local environments via numerous synthetic strategies. However, owing to the absence of a quantitative description, unraveling the site-specific reactivity and regulating their transformation remain challenging. Here, we show that two distinct Pt/CeO2 SACs can be reversibly generated by oxidative and nonoxidative dispersions, which contain varied Pt1On-Ceδ+ single-atom species despite similar Pt charge states and coordination numbers. By means of Raman spectroscopy and computational studies, we semiquantitatively reveal the distribution of diverse Pt1On-Ceδ+ species in each specific SACs. Remarkably, the minority species of Pt1O4-Ce3+-Ov accounting for only 14.2% affords the highest site-specific reactivity for low-temperature CO oxidation among the other abundant counterparts, i.e., Pt1O4-Ce4+ and Pt1O6-Ce4+. The second nearest oxygen vacancy (Ov) not only acts synergistically with the nearby active metal sites to lower the reaction barrier but also facilitates the dynamic transformation from six-coordinated to four-coordinated sites during cyclic nonoxidative and oxidative dispersions. This work elucidates the quantitative distribution and dynamic transformation of varied single-atom species in a given SAC, offering a more intrinsic descriptor and quantitative measure to depict the inhomogeneity of SACs.

Associations between air pollutants and risk of respiratory infection: patient-based bacterial culture in sputum.

Air pollution is a crucial risk factor for respiratory infection. However, the relationships between air pollution and respiratory infection based on pathogen detection are scarcely explored in the available literature. We detected respiratory infections through patient-based bacterial culture in sputum, obtained hourly data of all six pollutants (PM2.5, PM10, SO2, NO, CO, and O3) from four air quality monitoring stations, and assessed the relationships of air pollutants and respiratory bacterial infection and multi-drug-resistant bacteria. Air pollution remains a challenge for Mianyang, China, especially PM2.5 and PM10, and there are seasonal differences; pollution is the heaviest in winter and the lowest in summer. A total of 4237 pathogenic bacteria were detected, and the positive rate of multi-drug-resistant bacteria was 0.38%. Similar seasonal differences were found with respect to respiratory infection. In a single-pollutant model, all pollutants were significantly associated with respiratory bacterial infection, but only O3 was significantly associated with multi-drug-resistant bacteria. In multi-pollutant models (adjusted for one pollutant), the relationships of air pollutants with respiratory bacterial infection remained significant, while PM2.5, PM10, and O3 were significantly associated with the risk of infection with multi-drug-resistant bacteria. When adjusted for other five pollutants, only O3 was significantly associated with respiratory bacterial infection and the risk of infection with multi-drug-resistant bacteria, showing that O3 is an independent risk factor for respiratory bacterial infection and infection with multi-drug-resistant bacteria. In summary, this study highlights the adverse effects of air pollution on respiratory infection and the risk of infection with multi-drug-resistant bacteria, which may provide a basis for the formulation of environmental policy to prevent respiratory infections.

Evaluation of the GPS Precise Orbit and Clock Corrections from MADOCA Real-Time Products.

The Japanese Quasi-Zenith Satellite System (QZSS) is a regional navigation satellite system covering the entire Asia-Oceania region. Except for the standard satellite navigation signals, QZSS satellites also broadcast L6E augmentation signals with real time GNSS precise orbit every 30 s and clock messages every 1 s, which is very important and necessary for Real-Time precise point positioning (RTPPP) applications. In this paper, the MADOCA real-time services derived from L6E augmentation signals were evaluated for both accuracy and availability compared with IGS final products. To avoid the datum difference of GPS orbit between MADOCA real-time and IGS final products, the 7-parameters Helmert transformation was firstly used in this paper, and then the orbit was evaluated on radial, along, and cross-track directions. On the clock evaluation, the mean satellites clock errors were taken as reference clock error, and then the standard deviation (STD) was calculated for each satellite. Furthermore, the signal in space range errors (SISRE) were also summarized to evaluate the ranging-measurement accuracy. Seven-day evaluation results show that satellite orbit, clock errors, and the final SISRE errors range as being 1.8-3.9 cm, 0.04-0.15 ns (1.2-4.5 cm), and 5-10 cm, respectively. For the one-year long-term evaluation, daily SISRE errors in 2018 show consistent performance with that of seven days. Furthermore, the open source software RTKLIB was used to evaluate the kinematic PPP performance based on the MADOCA real-time products, and it shows that the daily positioning accuracy of the 20 globally distributed IGS stations can reach 4.9, 4.2, 11.7, and 12.1 cm in the east, north, up, and 3D directions, respectively. Hence, it is concluded that the current MADOCA real-time ephemeris products can provide orbit and clock products with SISRE on centimeters level with high interval, which could meet the demands of the RTPPP solution and serve real-time users who can access the MADOCA real-time products via L6E signal or internet.

Assessing Global Ionosphere TEC Maps with Satellite Altimetry and Ionospheric Radio Occultation Observations.

As global navigation satellite system (GNSS)stations are sparsely distributed in oceanic area, oceanic areas usually have lower precision than continental areas on a global ionosphere maps (GIM). On the other hand, space-borne observations like satellite altimetry (SA) and ionospheric radio occultation (IRO) have substantial dual-frequency observations in oceanic areas, which could be used for total electron content (TEC) retrieval. In this paper, the Jason-2 SA and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) IRO products were used to assess the precision of IGS GIM products. Both the systematic biases and scaling factors between the international GNSS service (IGS) GIM TEC and space-borne TEC were calculated, and the statistical results show that the biases and the scaling factors obviously vary under different temporal-spatial conditions. This analysis shows that these differences are variable with diurnal and latitude factors, that is, the differences in biases during the day time are higher than those during the night time, and larger biases are experienced at lower latitude areas than at high latitude areas. The results also show that in the southern hemisphere middle-high latitude area and some other central oceanic areas, the space-borne TEC values are even higher than GIM TEC values. As the precision of space-borne TEC should be evenly distributed around different areas on Earth, it can be explain that the TEC in these areas is undervalued by the current GIM model, and the space-borne SA and IRO techniques could be used as complementary observations to improve the accuracy and reliability of TEC values in these areas.

Soluble expression, purification, and characterization of active recombinant human tissue plasminogen activator by auto-induction in E. coli.

BACKGROUND: Human tissue plasminogen activator (tPA) belongs to the serine protease family. It converts plasminogen into plasmin and is used clinically to treat thrombosis. Human tPA is composed of 527 amino acids residues and contains 17 disulfide bonds. Escherichia coli has been used only rarely for the efficient production of recombinant tPA. However, the functional expression of full-length tPA that contains multiple disulfide bonds on an industrial scale remains challenging. Here, we describe the soluble expression and characterization of full-length tPA by auto-induction in E. coli. RESULTS: We achieved optimal levels of gene expression, minimized negative effects related to the production of heterologous proteins, and optimized cytoplasmic yields. Three different E. coli strains, BL21 (DE3), Rosetta, and Origami 2, could express tPA using an auto-induction mechanism. In addition, similar yields of recombinant protein were produced at temperatures of 33, 35, and 37°C. The E. coli strain origami 2 could increase disulfide bond formation in cytoplasmic tPA and produce purified soluble recombinant protein (~0.9 mg/l medium). The full-length tPA was monomeric in solution, and fibrin plate assays confirmed that the recombinant tPA displayed serine protease activity. CONCLUSIONS: This is the first report that describes the heterologous expression of correctly folded active full-length tPA. This could provide valuable information for using prokaryotic auto-induction expression systems to produce tPA at industrial and pharmaceutical levels without in vitro refolding during the production step.

Prevalence and species identification of trematode metacercariae in Qiqihar, Northeast China.

Fishborne trematode (FBT) is an important group of parasites that are endemic worldwide to a certain extent. However, despite the epidemiological significance, the species and phylogenetic evolution characteristics of FBT metacercariae have not been well studied. In this study, a total of 600 Pseudorasbora parva (P. parva) specimens were collected from Qiqihar, 61.8% (371/600) were found to be infected with trematode metacercariae. A total of three kinds of trematodes metacercariae were obtained, and they were identified as Clonorchis sinensis (C. sinensis), Metorchis orientalis (M. orientalis), and Metorchis taiwanensis (M. taiwanensis) by morphological and phylogenetic analysis with infection rates of 47.7% (286/600), 15.5% (93/600), and 23.7% (142/600), respectively. Meanwhile, a survey of the three trematodes metacercariae showed that the infection rate of C. sinensis metacercariae was the highest in September, up to 66% (66/100), and the lowest in June at 26% (26/100). The infection rate of M. orientalis metacercariae was the highest in October at 26% (26/100) and the lowest in June at 5% (5/100). The infection rate of M. taiwanensis metacercariae was at its peak in November at 36% (36/100) and the lowest in July at 15% (15/100). The co-infection of metacercariae of C. sinensis and M. taiwanensis was the most common and reached a peak in October, and their infection rate was higher in autumn than in summer. The peak of infection intensity of metacercariae for C. sinensis, M. orientalis, and M. taiwanensis were different: C. sinensis was 24/g in September, M. orientalis was 7/g in October, and M. taiwanensis was 10/g in November. From the above results, it was confirmed that three species of trematodes metacercaria played an important role in infection of second intermediate hosts in Qiqihar region. Studying the morphological characteristics and sequencing the ITS2 gene for a phylogenetic tree of them will be useful for future molecular evolution, biology, and ecology of trematode metacercariae.

Visceral Adiposity and Neutralizing Antibody Expression: An Adult-Based Cross-Sectional Study.

Purpose: Visceral adiposity is a significant risk factor for severe COVID-19. However, the impact of the Chinese visceral adiposity index (CVAI) on the efficacy of SARS-CoV-2 vaccines remains poorly understood. This study aims to explore the impact of CVAI on the production of neutralizing antibodies (NAb) in inactivated SARS-CoV-2 vaccines and the potential mechanism, thereby optimizing vaccination guidance. Methods: In this cross-sectional study, 206 health workers (completed two SARS-CoV-2 vaccination on February 8th and March 10th, 2021, respectively) were recruited. All baseline anthropometric parameters of the participants were collected, and venous blood samples were obtained 6 weeks later to measure peripheral innate immune cells, inflammatory cytokines, and NAb titers against SARS-CoV-2. CVAI were calculated according to the formula and divided participants into two groups depending on CVAI median. Results: The median NAb titer among healthcare workers was 12.94 AU/mL, with an efficacy of 87.86% for the SARS-CoV-2 vaccine. NAb titers were lower in the CVAI dysfunction group than in the CVAI reference group (median: 11.40 AU/mL vs 15.57 AU/mL), the hsCRP levels (median: 0.50 mg/L vs 0.30 mg/L) and peripheral monocyte count (mean: 0.47 × 109/L vs 0.42 × 109/L) in the CVAI dysfunction group were higher than in the CVAI reference group. Additionally, CVAI showed positive correlations with hsCRP, monocytes, lymphocytes, and B-lymphocytes, and a negative correlation with NAb titers. Conclusion: CVAI may inhibit SARS-CoV-2 neutralizing antibody expression through inducing immune dysfunction and chronic inflammation. Thus, more attention should be paid to the vaccination for high CVAI population to improve the effectiveness of vaccination, which could provide more robust support for COVID-19 epidemic prevention and control.

Purification, crystallization and preliminary X-ray crystallographic study of the tRNA pseudouridine synthase TruB from Streptococcus pneumoniae.

The RNA pseudouridine synthase TruB catalyses the isomerization of uridine to pseudouridine (Ψ) at residue 55 of elongator tRNAs. In order to better elucidate the functions of TruB in the formation of pseudouridine, the three-dimensional structure of full-length TruB was determined by X-ray crystallography. Here, the expression, purification, crystallization and preliminary crystallographic analysis of TruB from Streptococcus pneumoniae are reported. The crystal belonged to space group P2, with unit-cell parameters a = 37.65, b = 78.09, c = 56.33 Å, ß = 102.05°, and diffracted to a resolution of 1.7 Å. The crystal is most likely to contain one molecule in the asymmetric unit, with a VM value of 2.40 Å(3) Da(-1).

Cloning, purification, crystallization and preliminary X-ray studies of the putative transcriptional regulator SPD0280 from Streptococcus pneumoniae D39.

Streptococcus pneumoniae SPD0280 is a hypothetical protein that has been putatively identified as a transcriptional regulator. However, it has very low sequence identity to other well characterized transcriptional regulators. Determination of the three-dimensional structure may provide information for the characterization of proteins; therefore, it was decided to use X-ray diffraction analysis to learn more about this protein. Here, the expression, purification, crystallization and preliminary crystallographic analysis of SPD0280 from S. pneumoniae are reported. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 45.886, b = 66.785, c = 150.050 Å, and diffracted to a resolution of 2.5 Å. The crystals are likely to contain one molecule in the asymmetric unit, with a VM value of 2.06 Å(3) Da(-1).

Crystallization and preliminary X-ray crystallographic studies of DnaJ from Streptococcus pneumoniae.

DnaJ, cooperating with DnaK and GrpE, promotes the folding of unfolded hydrophobic polypeptides, dissociates protein complexes and translocates protein across membranes. Additionally, DnaJ from Streptococcus pneumoniae (SpDnaJ) is involved in the infectious disease process and is being developed as a potential vaccine to prevent bacterial infection. Here the expression, purification, crystallization and preliminary crystallographic analysis of SpDnaJ are reported. The crystals belong to space groups I222 or I212121 and the diffraction resolution is 3.0 Šwith unit-cell parameters a=47.68, b=104.45, c=234.57 Å. The crystal most likely contains one molecule in the asymmetric unit, with a VM value of 3.24 Å3 Da(-1) and a solvent content of 62.1%.

Urban particulate air pollution linked to dyslipidemia by modification innate immune cells.

Air particulate matter (PM) is an essential risk factor for lipid metabolism disorders. However, the underlying mechanism remains unclear. In this cross-sectional study, 216 healthcare workers were recruited to estimate the associations among the daily exposure dose (DED) of air PM, innate immune cells, and plasma lipid levels. All participants were divided into two groups according to the air particulate combined DED (DED-PMC). The peripheral white blood cell counts, lymphocyte counts, and monocyte counts and percentages were higher in the higher-exposure group (HEG) than in the lower-exposure group (LEG), whereas the percentage of natural-killer cells was lower in the HEG than in the LEG. The plasma concentrations of the total cholesterol, triglycerides, LDL-C, and apolipoprotein B were higher in the HEG than in the LEG, whereas the HDL-C and apolipoprotein A1 were lower in the HEG than in the LEG. A dose-effect analysis indicated that when the DED of the air PM increased, there were increased peripheral monocyte counts and percentages, a decreased NK cell percentage, elevated plasma concentrations of total cholesterol, triglycerides, LDL-C, and apolipoprotein B, and reduced plasma levels of HDL-C and apolipoprotein A1. In addition, the modification of the innate immune cells was accompanied by alterations in the plasma lipid levels in a dose-dependent manner. Mediation effect analysis suggested innate immune cells were the potential mediators for the associations among air PM exposure on abnormal lipid metabolism. These results indicated that chronic exposure to air PM may disturb lipid metabolism by altering the distribution of innate immune cells in the peripheral blood, ultimately advancing cardiovascular disease risk.

Side-to-side neurorrhaphy for high-level peripheral nerve injuries.

BACKGROUND: The results of peripheral nerve repair, especially for high-level peripheral nerve injuries, have been unsatisfactory. The method of side-to-side neurorrhaphy was developed in our laboratory from 1994 to 2002. This method involves suturing the injured nerve to a nearby donor nerve in a side-to-side manner. This study was performed to assess the clinical results of side-to-side neurorrhaphy in patients with high-level peripheral nerve injuries. METHODS: Twenty-five patients with various types of high-level peripheral nerve injuries who underwent side-to-side neurorrhaphy were studied. The British Medical Research Council (BMRC) scale was used to assess recovery of nerve function. RESULTS: Average follow-up duration was 3.2 years. Before surgery the patients had a nerve function of M0/S0 to M1/S1. After side-to-side neurorrhaphy, 7 patients had a score of M3/S4, 8 patients a score of M3/S3 and 10 patients a score of M2/S3. The total useful recovery rate (BMRC grade ≥3) was 60% for motor function and 100% for sensory function. Side-to-side neurorrhaphy did not result in any significant loss of donor nerve function. There was significant correlation between both the type of injury and the time interval between injury and surgery and motor nerve function. Age, gender and location of the injured nerve did not correlate with sensory or motor nerve function. CONCLUSION: Side-to-side neurorrhaphy appears to be promising as a feasible method for repair of high-level peripheral nerve injuries.

Increased body mass index linked to decreased neutralizing antibody titers of inactivated SARS-CoV-2 vaccine in healthcare workers.

Objective: Obesity is an important risk factor for COVID-19. However, whether obesity affects SARS-CoV-2 antibody production is unclear. This study aimed to identify the influence of obesity on neutralizing antibody production of an inactivated SARS-CoV-2 vaccine to better guide vaccination strategies. Methods: This cross-sectional study recruited a total of 239 healthcare workers (age, 21-50 years) from Suining Central Hospital during 22-23 April 2021. An electronic questionnaire on basic characteristics was completed by all participants. A general physical exam and fasting blood sampling by venipuncture were performed. Peripheral leukocyte counts and the ratios of leukocyte subsets, hepatorenal function, and the neutralizing antibody titers against SARS-CoV-2 were measured. Results: Among 239 healthcare workers, the participants with underweight, normal weight, overweight, and obesity accounted for 10.88%, 64.44%, 23.01%, and 1.67%, respectively. The highest peripheral monocyte counts were observed in the group with obesity, whereas the lowest were observed in the group with normal weight. Similar results were obtained with respect to percentage of peripheral monocytes. Participants with obesity had higher peripheral eosinophil counts and percentages than the other three groups. The median neutralizing antibody titer was 12.70 AU/mL, with 85.36% (n = 204) of participants were sufficiently protected against SARS-CoV-2. The lowest neutralizing antibody titers were observed in the group with obesity, whereas the highest were observed in the group that was underweight. Additionally, high BMI was significantly associated with high peripheral monocyte counts [B (95% CI) = 0.008 (0.002, 0.013)] and low neutralizing antibody titers [B (95% CI) = -1.934 (-3.663, -0.206)]. Conclusions: Obesity could induce chronic inflammation, and associated with lower neutralizing antibody titers against SARS-CoV-2 after inactivated SARS-CoV-2 vaccination.

The associations between air pollutant exposure and neutralizing antibody titers of an inactivated SARS-CoV-2 vaccine.

Air pollution is a critical risk factor for the prevalence of COVID-19. However, few studies have focused on whether air pollution affects the efficacy of the SARS-CoV-2 vaccine. To better guide the knowledge surrounding this vaccination, we conducted a cross-section study to identify the relationships between air pollutant exposure and plasma neutralizing antibody (NAb) titers of an inactivated SARS-CoV-2 vaccine (Vero cell, CoronaVac, SINOVΛC, China). We recruited 239 healthcare workers aged 21-50 years who worked at Suining Central Hospital. Of these, 207 were included in this study, depending on vaccination date. The data regarding air pollutants were collected to calculate individual daily exposure dose (DED). The geometric mean of all six pollutant DEDs was applied to estimate the combined toxic effects (DEDcomplex). Then, the participants were divided into two groups based on the mean value of DEDcomplex. The median plasma NAb titer was 12.81 AU/mL, with 85.99% vaccine efficacy in healthcare workers against SARS-CoV-2. In exposure group, observations included lower plasma NAb titers (median: 11.13 AU/mL vs. 14.56 AU/mL), more peripheral counts of white blood cells and monocytes (mean: 6.71 × 109/L vs. 6.29 × 109/L and 0.49 × 109/L vs. 0.40 × 109/L, respectively), and a higher peripheral monocyte ratio (7.38% vs. 6.50%) as compared to the reference group. In addition, elevated air pollutant DEDs were associated with decreased plasma NAb titers. To our knowledge, this study is the first to report the relationship between air pollutant exposure and plasma NAb titers of the SARS-CoV-2 vaccine. This suggests that long-term exposure to air pollutants may inhibit plasma NAb expression by inducing chronic inflammation. Therefore, to achieve early herd immunity and hopefully curb the COVID-19 epidemic, vaccinations should be administered promptly to those eligible, and environmental factors should be considered as well.

An MRI study of psoas major and abdominal large vessels with respect to the X/DLIF approach.

Extreme/direct lateral interbody fusion (X/DLIF) has been used to treat various lumbar diseases. However, it involves risks to injure the lumbar plexus and abdominal large vessels when it gains access to the lumbar spine via lateral approach that passes through the retroperitoneal fat and psoas major muscle. This study was aimed to determine the distribution of psoas major and abdominal large vessels at lumbar intervertebral spaces in order to select an appropriate X/DLIF approach to avoid nerve and large vessels injury. Magnetic resonance imaging scanning on lumbar intervertebral spaces was performed in 48 patients (24 males, 24 females, 54.2 years on average). According to Moro's method, lumbar intervertebral space was divided into six zones A, I, II, III, IV and P. Thickness of psoas major was measured and distribution of abdominal large vessels was surveyed at each zone. The results show vena cava migrate from the right of zone A to the right of zone I at L1/2-L4/5; abdominal aorta was located mostly to the left of zone A at L1/2-L3/4 and divided into bilateral iliac arteries at L4/5; Psoas major was tenuous and dorsal at L1/2 and L2/3, large and ventral at L3/4 and L4/5. Combined with the distribution of nerve roots reported by Moro, X/DLIF approach is safe via zones II-III at L1/2 and L2/3, and via zone II at L3/4. At L4/5, it is safe via zones I-II in left and via zone II in right side, respectively.

Functional reconstruction of ischemic contracture in the lower limb.

OBJECTIVE: To discuss the method of functional reconstruction of ischemic contracture in the lower limb and propose a classification protocol for ischemic contracture in the lower limb based on its severity and prognosis. METHODS: A total of 42 patients with ischemic contracture in the lower limb were included in this study. According to different types of disturbance and degrees of severity, surgical reconstructions consisting of nerve decompression, tendon lengthening or transfer, intrinsic foot muscle release and sural-tibial nerve anastomosis were performed in every patient. RESULTS: Postoperatively, all patients were able to walk on flat ground. Drop foot was corrected in 10 patients, and 5 patients still felt some difficulty during stair activity. Split Achilles tendon transfer to flexor hallucis longus tendon was performed in 12 patients, and their walking stability was improved. Seven patients accepted ipsilateral sural-tibial nerve anastomosis, and sensitivity recovery reached to S2 in 2 patients and S3 in 5 patients. CONCLUSIONS: Ischemic contracture in the lower limb is a devastating complication after lower limb trauma. The prevention of contracture is much more important than the treatment of an established contracture. Split Achilles tendon transfer to flexor hallucis longus tendon and sural-tibial nerve anastomosis, which was initially implemented by us, could improve the functional recovery of ischemic contracture in lower limbs, and thus provides a new alternative for functional reconstruction of ischemic contracture in the lower limb.

Particulate air pollution and respiratory Haemophilus influenzae infection in Mianyang, southwest China.

Particulate air pollution is correlated with many respiratory diseases. However, few studies have focused on the relationship between air particulate exposure and respiratory Heamophilus influenzae infection. Therefore, we detected respiratory Heamophilus influenzae infection by bacterial culture of sputum of patients, and we collected particulate air pollution data (including PM2.5 and PM10) from a national real-time urban air quality platform to analyze the relationship between particulate air pollution and respiratory Heamophilus influenzae infection. The mean concentrations of PM2.5 and PM10 were 37.58 µg/m3 and 58.44 µg/m3, respectively, showing particulate air pollution remains a severe issue in Mianyang. A total of 828 strains of Heamophilus influenzae were detected in sputum by bacterial culture. Multiple correspondence analysis suggested the heaviest particulate air pollution and the highest Heamophilus influenzae infection rates were all in winter, while the lowest particulate air pollution and the lowest Heamophilus influenzae infection rates were all in summer. In a single-pollutant model, each elevation of 10 µg/m3 of PM2.5, PM10, and PM2.5/10 (combined exposure level) increased the risk of respiratory Heamophilus influenzae infection by 34%, 23%, and 29%, respectively. Additionally, in the multiple-pollutant model, only PM2.5 was significantly associated with respiratory Heamophilus influenzae infection (B, 0.46; 95% confidence interval, 0.05-0.87), showing PM2.5 is an independent risk factor for respiratory Heamophilus influenzae infection. In summary, this study highlights air particulate exposure could increase the risk of respiratory Heamophilus influenzae infection, implying that stronger measures need to be taken to protect against respiratory infection induced by particulate air pollution.

Relations of blood lead levels to echocardiographic left ventricular structure and function in preschool children.

Lead (Pb) has been proved to exert adverse effect on human cardiovascular system. However, the cardiotoxicity of Pb on children is still unclear. The aim of this study was to evaluate left ventricular (LV) structure and function, by using echocardiographic indices, in order to elucidate the effect of Pb on low-grade inflammation related to left ventricle in healthy preschool children. We recruited a total of 486 preschool children, 310 from Guiyu (e-waste-exposed area) and 176 from Haojiang (reference area). Blood Pb levels, complete blood counts, and LV parameters were evaluated. Associations between blood Pb levels and LV parameters and peripheral leukocyte counts were analyzed using linear regression models. The median blood level of Pb and the counts of white blood cells (WBCs), monocytes, and neutrophils were higher in exposed group. In addition, the exposed group showed smaller left ventricle (including interventricular septum, LV posterior wall, and LV mass index) and impaired LV systolic function (including LV fractional shortening and LV ejection fraction) regardless gender. After adjustment for confounding factors, elevated blood Pb levels were significantly associated with higher counts of WBCs and neutrophils, and lower levels of LV parameters. Furthermore, counts of WBCs, monocytes, and neutrophils were negatively correlated with LV parameters. Taken together, smaller left ventricle and impaired systolic function were found in e-waste-exposed children and associated with chronic low-grade inflammation and elevated blood Pb levels. It indicates that the heart health of e-waste-exposed children is at risk due to the long-term environmental chemical insults.

Elevated levels of lead exposure and impact on the anti-inflammatory ability of oral sialic acids among preschool children in e-waste areas.

The oral health of preschool children in an electronic waste (e-waste) area is susceptible to lead (Pb) exposure increasing the risk of dental caries and causing periodontitis and other oral diseases. The aim of the present study is to investigate the relationship between chronic exposure to Pb and oral anti-inflammatory potential of preschool children. For this analysis, 574 preschool children from 2.5 to 6 years of age were recruited between November and December 2017, in which 357 preschool children were from Guiyu (n = 357), an e-waste-contaminated town, and 217 from Haojiang Shantou. We measured the levels of child blood Pb, salivary sialic acid, serum interleukin-6 (IL-6) and serum tumor necrosis factor-α (TNF-α), and investigated the prevalence of dental caries in deciduous teeth. The medians of blood Pb levels, serum IL-6 and TNF-α were significantly higher in the Guiyu children than in Haojiang children. Concomitantly, salivary sialic acids were lower in the Guiyu children [9.58 (3.97, 18.42) mg/dL] than in Haojiang [17.57 (5.95, 24.23) mg/dL]. Additionally, the prevalence of dental caries in deciduous teeth was significantly higher in the Guiyu children than in Haojiang (62.5% vs. 53.9%). Blood Pb levels were negatively correlated with salivary sialic acids, in which IL-6 played as a mediator of the association between blood Pb levels and saliva sialic acid concentrations according to the mediation model. To our knowledge, this is the first report on the potential association between chronic Pb exposure and the anti-inflammatory ability of oral sialic acids among preschool children. These results suggest that the chronic Pb exposure can reduce salivary sialic acid levels, attenuate oral anti-inflammatory potential and increase the potential risk of dental caries in deciduous teeth among preschool children in an e-waste site.