Hepatic artery pseudoaneurysm caused by chronic pancreatitis: Case report and literature review.

RATIONALE: Visceral artery pseudoaneurysm is a rare complication of chronic pancreatitis (CP), all pancreatic or peripancreatic arteries have been reported to be involved, while hepatic artery is less common. PATIENT CONCERNS: This case report illustrated a 42-year-old man with CP who developed right hepatic artery pseudoaneurysm (HAP), and finally he was treated with intravascular embolization. DIAGNOSES: The patient suffered from HAP due to acute attack of CP. INTERVENTIONS: The pseudoaneurysm located in a fine branch of right hepatic artery was embolized. OUTCOMES: The HAP of the patient was cured. He had no recurrent bloody stool or abdominal pain. The symptoms gradually relieved. CONCLUSION: Herein, we report a patient with CP who developed right HAP causing infected hematoma, gastrointestinal bleeding, and obstructive jaundice, and a literature review is also presented. HAP caused by CP is a rare disease in the clinic, but rupture of pseudoaneurysm is fatal. Careful evaluation, early detection, and prompt treatment should be performed when the patient is admitted and followed up.

Modeling multimedia fate and health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the coastal regions of the Bohai and Yellow Seas.

Using an improved multimedia fate model, this study simulated the spatial distributions, partitioning behaviors, and mass exchanges of PAH16 (16 species with priority by the USEPA) in multiple environmental compartments in the coastal regions of the Bohai and Yellow Seas, Northern China. The model predictions generally matched well with the measured results, as the deviations of most points were within one order of magnitude in the air, freshwater, and 3 soil compartments. The estimated concentrations of ΣPAH16 in the northern part were higher than those in the southern part, which was consistent with the emissions of each part. Approximately 97.6% of the ΣPAH16 mass was distributed in soils; therefore, soils served as the dominant sink of PAH16. The estimated net flux of ΣPAH16 from air to soil ranged from 0.4 to 10.7 mg/m2/year (an average of 3.2 mg/m2/year), and the estimated flux of deposition from air to soil fell in the range of 0.4-10.8 mg/m2/year (an average of 3.2 mg/m2/year), which served as the dominant process at the air-soil interface. The estimated net flux of ΣPAH16 from air to freshwater ranged from -15.3 to 9.4 mg/m2/year (an average of -0.3 mg/m2/year), and the reversed volatilization flux from freshwater to air ranged from 0.01 to 21.1 mg/m2/year (an average of 3.7 mg/m2/year). This situation indicated notable spatial variations and volatilization as the main process affecting the direction of net flux at the air-freshwater interface. Deterministic risk assessment and probabilistic risk assessment were conducted. The overall health risks of the studied regions were acceptable, while the excess lifetime cancer risk (ELCR) by air inhalation was greater than that by soil ingestion. CAPSULE: Multimedia fate model-predicted distributions and compositions of PAH16 in different compartments, compartmental exchange fluxes and directions, and deterministic and probabilistic ELCR via different exposure pathways were assessed.

Dual polymeric prodrug co-assembled nanoparticles with precise ratiometric co-delivery of cisplatin and metformin for lung cancer chemoimmunotherapy.

The combination therapy of cisplatin (CDDP) and metformin (MET) is a clinical strategy to enhance therapeutic outcomes in lung cancer. However, the efficacy of this combination is limited due to the asynchronous pharmacokinetic behavior of CDDP and MET, used as free drugs. Therefore, in this work, hyaluronic acid-cisplatin/polystyrene-polymetformin (HA-CDDP/PMet) dual-prodrug co-assembled nanoparticles were developed, with precise ratiometric co-delivery of CDDP and MET for chemo-immunotherapy against lung cancer. The HA-CDDP/PMet NPs showed a spherical morphology with an average particle size of 166.5 nm and a zeta potential of -17.4 mV at an HA-CDDP and PMet mass ratio of 1/1. The content of CDDP and MET in HA-CDDP/PMet NPs was 3.7% and 15.2%, respectively. In vitro antitumor effects of CDDP and MET resulted in an improved synergistic action on proliferation inhibition and apoptosis induction on Lewis lung cancer cells. Moreover, in vivo by co-delivered HA-CDDP/PMet NPs into tumor cells, with an excellent intracellular CDDP and MET cleavage. These nanoparticles exhibited significantly increased tumor accumulation and tumor growth inhibition and prolonged animal overall survival in Lewis lung cancer bearing mice without nephrotoxicity, excess of free drugs and homo-prodrugs. The synergistic effect of MET and CDDP in HA-CDDP/PMet NPs resulted in up-regulation of the cleaved poly(ADP)-ribose polymerase (PARP) protein to induce tumor cell apoptosis, and down-regulation of the excision repair cross-complementation group 1 (ERCC1) protein level to decrease the resistance to CDDP. The synergistic effect of MET and CDDP in HA-CDDP/PMet NPs also resulted in induction of the adenosine monophosphate (AMP)-activated protein kinase-α (AMPK-α) pathway and inhibition of the mammalian target of rapamycin (mTOR), finally exerting a chemotherapeutic effect and modulating a potent immunotherapeutic function with an increase in CD4+ and CD8+ T cells, a concomitant decrease in regulatory T (Treg) cells, and an increased expression of the cytokines IFN-γ and TNF-α. Therefore, the immunochemotherapy using CDDP and MET mediated by this dual prodrug co-assembled nano-platform might provide a promising treatment strategy against lung cancer.

Tumor Microenvironment-Triggered Charge Reversal Polymetformin-Based Nanosystem Co-Delivered Doxorubicin and IL-12 Cytokine Gene for Chemo-Gene Combination Therapy on Metastatic Breast Cancer.

Cancer metastasis is the leading cause of high mortality and disease recurrence in breast cancer. In this study, a novel tumor microenvironment charge reversal polymetformin (PMet)-based nanosystem co-delivering doxorubicin (DOX) and plasmid encoding IL-12 gene (pIL-12) was developed for chemo-gene combination therapy on metastatic breast cancer. Cationic PMet was readily self-assembled into micelles for DOX physical encapsulation and pIL-12 complexation, and a hyaluronidase-sensitive thiolated hyaluronic acid (HA-SH) was then collaboratively assembled to the pIL-12/DOX-PMet micelleplexes, abbreviated as HA/pIL-12/DOX-PMet. DOX/pIL-12 loaded in HA/pIL-12/DOX-PMet micelleplexes presented prolonged circulation in blood, efficient accumulation in tumors, and internalization in tumor cells via CD44 receptor-mediated tumor specific-targeting, and DOX/pIL-12 was co-released in endo/lysosomes tumor microenvironment followed by HAase-triggered HA-SH deshielding from HA/pIL-12/DOX-PMet micelleplexes. Moreover, HA/PMet micelleplexes displayed excellent pIL-12 transfection and IL-12 expression in tumors of 4T1 tumor-bearing mice. Importantly, HA/pIL-12/DOX-PMet micelleplexes synergistically enhanced the NK cells and tumor infiltrated cytotoxic T lymphocytes and modulated the polarization from protumor M2 macrophages to activated antitumor M1 macrophages, with concomitant decreasing of the immunosuppressive regulatory T (Treg) cells, accompanied by an increase in the cytokines expression of IL-12, IFN-γ and TNF-α, consequently showing an improved antitumor and antimetastasis activity in 4T1 breast cancer lung metastasis mice model. In conclusion, the tumor microenvironment charge reversal HA/PMet nanosystem holds great promise for DOX/pIL-12 co-delivery and exploitation in chemo-gene combination therapy on metastatic breast cancer.

Codelivered Chemotherapeutic Doxorubicin via a Dual-Functional Immunostimulatory Polymeric Prodrug for Breast Cancer Immunochemotherapy.

Immunochemotherapy is viewed as a promising approach for cancer therapy via combination treatment with immune-modulating drugs and chemotherapeutic drugs. A novel dual-functional immunostimulatory polymeric prodrug carrier PEG2k-Fmoc-1-MT was developed for simultaneously delivering 1-methyl tryptophan (1-MT) of an indoleamine 2,3-dioxygenase (IDO) inhibitor and chemotherapeutic doxorubicin (DOX) for breast cancer immunochemotherapy. DOX/PEG2k-Fmoc-1-MT micelles were more effective in cell proliferation inhibition and apoptosis induction in 4T1 cells. PEG2k-Fmoc-1-MT prodrug micelles presented enhanced inhibition ability of IDO with decreased kynurenine production and increased the proliferation in dose-dependent manners of effector CD4+ and CD8+ T cells. DOX/PEG2k-Fmoc-1-MT micelles exhibited prolonged blood circulation time and superior accumulation of DOX and 1-MT in tumors compared to that of DOX and 1-MT solutions. A significantly enhanced immune response of the DOX/PEG2k-Fmoc-1-MT micelles was observed with the decreasing tryptophan/kynurenine ratio in blood and tumor tissue, promoting effector CD4+ and CD8+ T cells while reducing regulatory T cell (Tregs) expression. Meanwhile, the coreleased DOX-triggered immunogenic cell death action combined with the cleaved 1-MT promoted the related cytokine secretion of tumor necrosis factor-α, interleukin-2, and interferon-γ, further facilitating the T cell-mediated immune responses. More importantly, the DOX-loaded micelles led to a significantly improved inhibition on tumor growth and prolonged animal survival rate in a 4T1 murine breast cancer model. In conclusion, DOX codelivered by a PEG2k-Fmoc-1-MT immunostimulatory polymeric prodrug showed a maximum immunochemotherapy efficacy against breast cancer.

Occurrence, source, and risk assessment of atmospheric parent polycyclic aromatic hydrocarbons in the coastal cities of the Bohai and Yellow Seas, China.

Parent polycyclic aromatic hydrocarbons (PPAHs) in the ambient air of the coastal cities near the Bohai and Yellow Seas were measured over a full year. The range and geometric average of total PPAH29 (29 species) were 5.16-1.22 × 103 and 118 ng/m3, respectively, with 77 ±â€¯14% in a gaseous phase. The 16 priority components accounted for 90 ±â€¯4% of the total mass concentration. The incremental life cancer risk (ILCR) via inhalation exposure to the PPAHs (3.17 × 10-4) was underestimated by 80%, as only the priority PPAHs were considered. The air concentrations of PPAHs in the Bohai Sea area were generally higher (p < 0.01) than those in the Yellow Sea area. A significant increase (p < 0.01) in the levels of PPAHs and large fractions of high molecular weight (HMW) components were observed in winter. Absorption by particulate organic carbon dominated in gas-particle partitioning of the PPAHs, and the seasonal variations in gas-particle partitioning of the low and moderate molecular weight compounds were more noticeable relative to the HMW species. In summer, significantly higher concentrations of PPAHs were found in the daytime than during nighttime, while the opposite case occurred in winter (p < 0.05). The positive matrix factorization (PMF) results indicated greater contributions of coal and biomass combustion to the PPAH emissions in the coastal cities of the Bohai Sea area compared with the Yellow Sea area. The burning of coal and biomass served as the main source of PPAHs in winter, while traffic exhaust was the dominant source in other seasons. The potential source contribution function (PSCF) revealed the important impacts of the external inputs on the local PPAHs via air mass transport. The contributions of the resolved emission sources to the ILCR were clearly different from those of the mass concentrations, indicating the necessity for source-oriented risk assessments.

Effects of temperature on the emission of particulate matter, polycyclic aromatic hydrocarbons, and polybrominated diphenyl ethers from the thermal treatment of printed wiring boards.

The effects of temperature on the emission of pollutants during the thermal treatment of electronic waste have rarely been investigated. The emission of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and polybrominated diphenyl ethers (PBDEs) from the thermal treatment of printed wiring boards was investigated over a temperature range of 320-600 °C. The emission factors (EFs) were determined to be within 1.6-7.6 g/kg, 2.23-11.9 µg/g, and 0.9-5.5 µg/g, respectively. High temperatures increased the formation of PAHs and CO, but decreased the emission of PBDEs, PM, and organic carbon. A temperature of 480 °C was determined to be optimal. Low-molecular-weight components were the dominant PAH species. The compositional profiles of PBDEs were clearly observed to vary with the temperature. Small particles (< 2.1 µm) that were more affected by temperature were dominant in PM, particle-bound PAHs, and PBDEs at all temperatures. High temperature increased the EFs of gaseous PAHs but had no remarkable effect on those of particulate PAHs. The freshly emitted PAHs primarily existed in the particulate phase at low temperatures, while the gaseous phase PAHs became prevailing at ≥ 520 °C. The particulate PBDEs were more susceptible to temperature and overwhelmingly dominant over the entire temperature range considered.

Characteristics and human inhalation exposure of ionic per- and polyfluoroalkyl substances (PFASs) in PM10 of cities around the Bohai Sea: Diurnal variation and effects of heating activity.

Atmospheric PM10 (particulate matter with aerodynamic diameter <10 µm) samples were collected in the cities along the Bohai Sea Rim during heating and non-heating periods, and ionic per- and polyfluoroalkyl species (PFASs) in the PM10 were measured. The total concentration of ionic PFASs ranged from 21.8 to 87.0 pg/m3, and the mean concentration of ionic PFASs during the day (42.6 pg/m3) was slightly higher than that at night (35.1 pg/m3). Generally, diurnal variations in the levels of ionic PFASs were consistent with those in the PM10 concentrations. Perfluorooctanoic acid (PFOA, 23.5-33.7%), perfluoropentanoic acid (PFPeA, 28.3-39.9%) and perfluorobutyric acid (PFBA, 17.1-20.1%) accounted for the dominant compositional contributions. Significant positive correlations (p < 0.05) between the main components of PFASs and O3 implied that oxidative degradation (O3 served as the main oxidant) in the period of non-heating may affect the short-chain PFASs. The clustering analysis of a 72-h backward trajectory indicated that cross-provincial transport contributed to ionic PFASs at the sampling sites. Compared with ingestion via daily diet, the inhalation of PM10 exhibited an insignificant contribution to the estimated average daily intakes (ADIs) of PFASs by different age groups. In addition, the calculated hazard ratios (HRs) for the non-cancer respiratory risk, based on the air concentrations of PFOA and perfluorooctane sulfonate (PFOS), also manifested lower non-cancer risk through inhalation exposure. CAPSULE: The effects of heating and non-heating activity and diurnal variation on the concentrations of PFASs, dominated by PFOA, PFPeA, and PFBA in PM10, were determined, and atmospheric trans-provincial input served as an important source.

Co-Delivery of Paclitaxel by a Capsaicin Prodrug Micelle Facilitating for Combination Therapy on Breast Cancer.

Poor anticancer ability, serious adverse reaction, and drug resistance against paclitaxel (PTX) have limited its clinical applications. When a mouse breast carcinoma cell line (4T1) was treated with both PTX and capsaicin (CAP), there was a synergistic anti-proliferative effect demonstrated with a combination index of 0.28. Therefore, a novel polyethylene glycol-derivatized CAP (PEG-Fmoc-CAP2) polymeric prodrug micellar carrier was developed and further encapsulated with PTX for antitumor combination treatment. The PEG-Fmoc-CAP2 polymeric micelles co-delivered with PTX achieved a 62.3% fraction of apoptotic cells in comparison to 45.4% fraction of apoptotic cells to that upon treatment with PTX alone. Comparable CAP amounts were found in the cell lysate treatment with PEG-Fmoc-CAP2-conjugated micelles to that of free CAP-treated 4T1 cells after 12 h treatment. Pharmacokinetic and biodistribution studies showed that the micelles possessed much longer circulation time in blood and preferential tumor tissue accumulation compared to the Taxol solution. Importantly, PTX/CAP-loaded micelles exhibited superior in vivo antitumor activity on the inhibition rate of tumor growth than other treatments (70.5% tumor growth reduction in PTX/CAP micelle-treated mice vs 57.8, 43.3, and 23.8% of tumor growth inhibition rate in PTX/PEG-Fmoc-OA2 micelles, Taxol, and PEG-Fmoc-CAP2 micelle-treated mice, respectively). Thus, the dual-functional PEG-Fmoc-CAP2 polymeric prodrug micelles are a promising co-delivery nanosystem for achieving synergistic antitumor efficacy of PTX and CAP.

Emission factors of particulate matter, CO and CO2 in the pyrolytic processing of typical electronic wastes.

A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes (E-wastes), including printed wiring boards (PWBs) and plastic casings. The generated particulate matter (PM) of different particle sizes, carbon monoxide (CO) and carbon dioxide (CO2) were determined, and the corresponding emission factors (EFs) were estimated. Finer particles with particle sizes of 0.4-2.1 µm accounted for 78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings, respectively, and the corresponding EFs were 9.68 ±â€¯4.81 and 18.49 ±â€¯7.2 g/kg, respectively. The EFs of CO and CO2 from PWBs and plastic casings were 55.9 ±â€¯26.9 and 1182 ±â€¯439 g/kg, and 133.6 ±â€¯34.6 and 2827 ±â€¯276 g/kg, respectively. Compared with other emission sources, such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher, especially for PM. There were significant positive correlations (p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO2, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons (PAHs); however, the same result was not observed for plastic casings.

Multifunctionalized Micelles Facilitate Intracellular Doxorubicin Delivery for Reversing Multidrug Resistance of Breast Cancer.

Intracellular doxorubicin (DOX) pumping out of cells through the P-glycoprotein (P-gp) transporter leads to the reduction of intracellular DOX levels and induces multidrug resistance (MDR). A hyaluronic acid-deoxycholic acid-histidine and Pluronic F127 (PF127) mixed micellar system, named HA-DOCA-His-PF micelles, functionalized with active targeted endocytosis mediated via CD44 receptor, intracellular triggered DOX release under endosome-pH, and combined with PF127-mediated P-gp efflux inhibition was developed for sufficient intracellular DOX delivery and MDR reversion. The DOX/HA-DOCA-His-PF drug-loaded micelles displayed endosomal pH-mediated self-assembly/disassembly characteristics, triggered DOX release under an endosomal (pH 5.5) environment, and demonstrated enhanced cytotoxicity and superior MDR reversion performance against drug-resistant MCF-7/Adr tumor cells. Importantly, superior antitumor activity of DOX/HA-DOCA-His-PF micelles was presented on the growth inhibition of MCF-7/Adr tumor cells, by further inhibiting the P-gp activity on intracellular DOX efflux through the depletion of intracellular adenosine triphosphate content. This multifunctional micellar system could be facilitated by the intracellular DOX delivery for reversing MDR of breast cancer.

Emission behaviors of nitro- and oxy-polycyclic aromatic hydrocarbons during pyrolytic disposal of electronic wastes.

Emission factors (EFs) of polycyclic aromatic hydrocarbon (PAH) derivatives (12 nitro-PAHs and 4 oxy-PAHs) during the pyrolysis of two types of electronic waste (E-waste) were measured. Compositional profile, particle size distribution, gas-particle partitioning, correlations with precursor species and influences of pyrolytic temperature were investigated. The derivative products were dominated by oxy-PAHs. The averaged EFs of oxy-PAHs were 3.37 ±â€¯4.10 µg/g and 32.6 ±â€¯18.1 µg/g for PWBs and plastic casings, respectively, and those of nitro-PAHs were 85.7 ±â€¯92.4 ng/g and 83.3 ±â€¯69.7 ng/g, respectively. Most EFs of derivative species significantly correlated with their corresponding parent PAHs (p < 0.05), except a few cases, indicating formation of derivatives via related reactions of parent species. Most nitro-PAHs occurred in fine particles with the size < 2.1 µm, and oxy-PAHs were prevailing in fine particles with the size between 0.4 µm and 2.1 µm. Proportions of oxy-PAHs in particulate phase, especially those with higher molecular weight, were noticeably greater than those of the corresponding parent species. Below 480 °C, there was no evident difference in the EFs of PAH derivatives, while the EFs noticeably increased from 520 °C. With the increasing temperature, the majority of oxy-PAHs still occurred on finer particles, while the contribution of coarser particles tended to increase.

Characteristics and oxidative potential of atmospheric PM2.5 in Beijing: Source apportionment and seasonal variation.

PM2.5 (particulate matter with the aerodynamic diameter Dp < 2.5 µm) was hypothesized to generate reactive oxygen species (ROS) and induce oxidative stress associated with inflammation and cardiovascular diseases. In the current study, PM2.5 concentrations, water-soluble ions and elements, carbonaceous components and ROS activity characterized by the dithiothreitol (DTT) assay were determined for the PM2.5 samples collected in Beijing, China, over a whole year. Source apportionments of PM2.5 and DTT activity were also performed. The mean ±â€¯standard deviation of PM2.5, DTTm (mass-normalized DTT activity) and DTTv (volume-normalized DTT activity) were 113.8 ±â€¯62.7 µg·m-3, 0.13 ±â€¯0.10 nmol·µg-1·min-1 and 12.26 ±â€¯6.82 nmol·m-3·min-1, respectively. The seasonal averages of DTTm and DTTv exhibited peak values during the local summer. Organic carbon (OC), NO3-, SO42-, NH4+ and elemental carbon (EC) were the dominant components in the constituents tested. Higher concentrations of carbonaceous components occurred in autumn and winter compared with spring and summer. Based on the positive matrix factorization model (PMF), the simulation results of source apportionment for PM2.5 in Beijing, obtained using the annual data, identified the main categories as follows: dust, coal combustion, secondary sulfate and industrial emissions, vehicle emissions and secondary nitrates. Most detected constituents exhibited significantly positive correlations with DTTv (p < 0.01). The results corresponding to multiple linear regression (MLR) between DTTv activity and source contribution to PM2.5 manifested the sensitivity sequence of DTTv activity for the resolved sources as vehicle emissions > secondary sulfate and industrial emissions > coal combustion > dust. CAPSULE: Based on a descending sequence of relative contribution, the diagnostic sources of DTTv activity in PM2.5 from Beijing included primarily vehicle emissions, secondary sulfates and industrial emissions, coal combustion, and dust.

Characteristics of perfluoroalkyl acids in atmospheric PM10 from the coastal cities of the Bohai and Yellow Seas, Northern China.

The concentration distributions, compositional profiles and seasonal variations of 17 perfluoroalkyl acids (PFAAs) in PM10 (particles with aerodynamic diameters < 10 µm) were determined in seven coastal cities of the Bohai and Yellow Seas. The detection rates of perfluorooctanoic acid (PFOA) and short-chain components (perfluoroalkyl carboxylic acids (PFCAs) with ≤7 carbon atoms and perfluoroalkane sulfonic acids (PFSAs) with ≤5 carbon atoms) were much higher than those of other long-chain PFAA species. The annual average concentration of total PFAAs in PM10 ranged from 23.6 pg/m3 to 94.5 pg/m3 for the sampling cities. The monthly mean concentrations of PFAAs in PM10 in some sampling cities reached a peak value in winter, while no significant seasonal differences presented in other cities. High concentrations of PFAAs in the northern cities generally occurred during the local heating period (from November to March). Generally, the dominant components of PFAAs were PFOA and perfluorobutyric acid (PFBA). Some significantly positive correlations (p < 0.01) between the 10 dominant components were revealed in the sampling cities, which implied similar sources and fate behaviors. Based on the simulated 72-hr backward trajectory tracking of air masses, the clustering results demonstrated the sampling cities were affected mainly by the atmospheric transport in sequence from the northwest, the southwest and the open seas, and many transport trajectories of air masses passed by the local fluorine chemical manufacturers in Liaoning, Shandong, Jiangsu, and Hubei Provinces. The estimated average daily intake (ADI) corresponding to the residents in different age groups indicated insignificant contributions to PFOA and perfluorooctane sulfonate (PFOS) exposures by inhalation of PM10 compared to ingestion by daily diet, while the higher ADI of PFOA than the reported levels for adults should be a concern. The calculated hazard ratios (HR) exhibited low noncancer risks by inhalation exposure to PFOA and PFOS in PM10.

Emission characteristics of polycyclic aromatic hydrocarbons from pyrolytic processing during dismantling of electronic wastes.

Two typical types of electronic waste (E-waste) were selected to investigate the emission characteristics of polycyclic aromatic hydrocarbons (PAHs) during pyrolytic processing, including emission factor, compositional profile, size distribution and gas-particle partitioning. The mean emission factors (EFs) of total PAHs were measured to be 2.77 ±â€¯1.41 µg/g and 23.65 ±â€¯14.52 µg/g for printed wiring boards and plastic casings, respectively, lower than those for coal combustion and biomass burning. Low molecular weight species were predominant in exhaust fumes, with overwhelming amounts of naphthalene (NAP) and phenanthrene (PHE) in the gaseous phase and particulate phase, respectively. The particle-size distribution exhibited the largest enrichment of total PAHs in finer particles less than 2.1 µm. Similarly, the distributions of individual species were dominated by finer particles. Most freshly emitted PAHs were liable to exist in particulate phase relative to gaseous phase. Based on the benzo[a]pyrene equivalent carcinogenic power, PAHs in particulate phase may have much stronger toxicity compared with those present in gaseous phase. The gas-particle partitioning behaviors of freshly emitted PAHs from pyrolytic processing of E-wastes were mainly regulated by absorption rather than adsorption, and the gas-particle partitioning did not reach equilibrium.

Oxidative potential of ambient PM2.5 in the coastal cities of the Bohai Sea, northern China: Seasonal variation and source apportionment.

Emissions of air pollutants from primary and secondary sources in China are considerably higher than those in developed countries, and exposure to air pollution is main risk of public health. Identifying specific particulate matter (PM) compositions and sources are essential for policy makers to propose effective control measures for pollutant emissions. Ambient PM2.5 samples covered a whole year were collected from three coastal cities of the Bohai Sea. Oxidative potential (OP) was selected as the indicator to characterize associated PM compositions and sources most responsible for adverse impacts on human health. Positive matrix factorization (PMF) and multiple linear regression (MLR) were employed to estimate correlations of PM2.5 sources with OP. The volume- and mass-based dithiothreitol (DTTv and DTTm) activities of PM2.5 were significantly higher in local winter or autumn (p < 0.01). Spatial and seasonal variations in DTTv and DTTm were much larger than mass concentrations of PM2.5, indicated specific chemical components are responsible for PM2.5 derived OP. Strong correlations (r > 0.700, p < 0.01) were found between DTT activity and water-soluble organic carbon (WSOC) and some transition metals. Using PMF, source fractions of PM2.5 were resolved as secondary source, traffic source, biomass burning, sea spray and urban dust, industry, coal combustion, and mineral dust. Further quantified by MLR, coal combustion, biomass burning, secondary sources, industry, and traffic source were dominant contributors to the water-soluble DTTv activity. Our results also suggested large differences in seasonal contributions of different sources to DTTv variability. A higher contribution of DTTv was derived from coal combustion during the local heating period. Secondary sources exhibited a greater fraction of DTTv in summer, when there was stronger solar radiation. Traffic sources exhibited a prevailing contribution in summer, and industry contributed larger proportions in spring and winter. Future abatement priority of air pollution should reduce the sources contributing to OP of PM2.5.

PBDE emission from E-wastes during the pyrolytic process: Emission factor, compositional profile, size distribution, and gas-particle partitioning.

Polybrominated diphenyl ether (PBDE) pollution in E-waste recycling areas has garnered great concern by scientists, the government and the public. In the current study, two typical kinds of E-wastes (printed wiring boards and plastic casings of household or office appliances) were selected to investigate the emission behaviors of individual PBDEs during the pyrolysis process. Emission factors (EFs), compositional profile, particle size distribution and gas-particle partitioning of PBDEs were explored. The mean EF values of the total PBDEs were determined at 8.1 ±â€¯4.6 µg/g and 10.4 ±â€¯11.3 µg/g for printed wiring boards and plastic casings, respectively. Significantly positive correlations were observed between EFs and original addition contents of PBDEs. BDE209 was the most abundant in the E-waste materials, while lowly brominated and highly brominated components (excluding BDE209) were predominant in the exhaust fumes. The distribution of total PBDEs on different particle sizes was characterized by a concentration of finer particles with an aerodynamic diameter between 0.4 µm and 2.1 µm and followed by less than 0.4 µm. Similarly, the distribution of individual species was dominated by finer particles. Most of the freshly emitted PBDEs (via pyrolysis) were liable to exist in the particulate phase with respect to the gaseous phase, particularly for finer particles. In addition, a linear relationship between the partitioning coefficient (KP) and the subcooled liquid vapor pressure (PL0) of the different components indicated non-equilibrium gas-particle partitioning during the pyrolysis process and suggested that absorption by particulate organic carbon, rather than surface adsorption, governed gas-particle partitioning.

[Effects of a comprehensive intervention program on simple obesity of children in kindergarten].

OBJECTIVE: The purpose of the study was to explore a comprehensive management program for the obese children in kindergarten. The program should be scientific, rational, suitable for kindergarten, and easy to apply. Child care workers, parents, and child health care doctors participated in the program to help obese children establish a scientific life style through their daily life, to control their weight and to maintain their physical and mental health. METHODS: The theories of behavior science, nutriology and kinematics were applied to make the weight control of obese children in kindergarten quantified and relatively standardized. Children were divided into three groups, intervened obese children, non-intervened obese children and normal children. Data such as weight, height, and body mass index (BMI) were observed to assess the effect of weight control and define whether it affects the linear gain of children's height. RESULTS: The recovery rate of intervened obese group, non-intervened group was 62.5% and 5.3%, respectively. The general effective rate was 91.7% and 15.8%, respectively. The weight gain of intervened group was 4.15 kg lower than that of non-intervened group. The BMI of intervened group significantly decreased by 2.9 as compared to the non-intervened group. The height gain of intervened group was similar to that of normal group. Parents and health care workers' realization of children obesity and their corresponding actions, the behaviors of obese children at home and in kindergarten were changed toward the direction beneficial to weight control. CONCLUSION: The implementation of the comprehensive intervention program for obesity in children, which involved obese children, child care worker, parents, and child care doctors alleviated the obesity level of those obese children without affecting their normal height gain. The program was safe and effective. Through the comprehensive intervention, the obese children could establish good habits during the sensitive period.