Design and structure-activity relationships of ether-linked alkylides: Hybrids of 3-O-descladinosyl macrolides and quinolone motifs.

Ketolides (3-keto) such as TE-802 and acylides (3-O-acyl) like TEA0929 are ineffective against constitutively resistant pathogens harboring erythromycin ribosomal methylation (erm) genes. Following our previous work on alkylides (3-O-alkyl), we explored the structure-activity relationships of hybrids combining (R/S) 3-descladinosyl erythromycin with 6/7-quinolone motifs, featuring extended ether-linked spacers, with a focus on their efficacy against pathogens bearing constitutive erm gene resistance. Optimized compounds 17a and 31f not only reinstated efficacy against inducibly resistant pathogens but also demonstrated significantly augmented activities against constitutively resistant strains of Streptococcus pneumoniae and Streptococcus pyogenes, which are typically refractory to existing C-3 modified macrolides.

Chemical compositions and source apportionment of PM during clear and hazy days: Seasonal changes and impacts of Youth Olympic Games.

Seasonal changes in chemical compositions and source apportionment of PM during clear and hazy days help to develop effective control policy, but limited information is available in megacity Nanjing. In this study, 102 PM samples were collected during clear and hazy days from 4 seasons in 2014-2015. Their chemical compositions (organic and elemental carbon, 8 water-soluble ions, and 22 inorganic elements) were determined, which were used for PM source apportionment using the PMF model.

Novel Method for in Situ Monitoring of Organophosphorus Flame Retardants in Waters.

Widespread use of organophosphorus flame retardants (OPFRs) and their ubiquity in water results in the need for a robust and reliable monitoring technique to better understand their fate and environmental impact. In situ passive sampling using the diffusive gradients in thin-films (DGT) technique provides time-integrated data and is developed for measuring OPFRs here. Ultrasonic extraction of binding gels in methanol provided reliable recoveries for all tested OPFRs.

In situ measurement of perfluoroalkyl substances in aquatic systems using diffusive gradients in thin-films technique.

To better understand the environmental impact of ubiquitous perfluoroalkyl substances (PFASs) in waters, reliable and robust measurement techniques are needed. As one of the most widely used passive sampling approaches, diffusive gradients in thin-films (DGT) is not only easy to handle but also provides time-weighted analyte concentrations. Based on DGT with XAD18 as a binding agent, we developed a new methodology to measure two frequently detected PFASs in surface waters and wastewaters, i.

Food influence on lead relative bioavailability in contaminated soils: Mechanisms and health implications.

To determine the effects of dietary constituents on soil Pb oral bioavailability, Pb relative bioavailability (RBA) in 3 soils contaminated by zinc smelting (ZS), wire-rope production (WR), and metal mining (MM) was measured under fasted and fed states with 9 foods. Under fasted state, Pb-RBA was 84.4 ± 10.

Cellular responses of normal (HL-7702) and cancerous (HepG2) hepatic cells to dust extract exposure.

Cancerous human liver cell line has been used to test the hepatic toxicity of indoor dust, showing its organic extract decreases cell viability. However, little is known about its impact on normal human liver cell line. In the present study, we compared the cellular responses between carcinoma cell line (HepG2) and normal cell line (HL-7702) after exposing to 10-640 μg/100 μL organic dust extract for 24 h.

Physical and chemical characteristics of PM and its toxicity to human bronchial cells BEAS-2B in the winter and summer.

With the increasing occurrence of haze during the summer, the physicochemical characteristics and toxicity differences in PM in different seasons are of great concern. Hangzhou is located in an area that has a subtropical monsoon climate where the humidity is very high during both the summer and winter. However, there are limited studies on the seasonal differences in PM in these weather conditions.

Impact of particle size on distribution and human exposure of flame retardants in indoor dust.

The effect of dust particle size on the distribution and bioaccessibility of flame retardants (FRs) in indoor dust remains unclear. In this study, we analyzed 20 FRs (including 6 organophosphate flame retardants (OPFRs), 8 polybrominated diphenyl ethers (PBDEs), 4 novel brominated flame retardants (NBFRs), and 2 dechlorane plus (DPs)) in composite dust samples from offices, public microenvironments (PME), and cars in Nanjing, China. Each composite sample (one per microenvironment) was separated into 6 size fractions (F1-F6: 200-2000µm, 150-200µm, 100-150µm, 63-100µm, 43-63µm, and <43µm).

Effects of organophosphorus flame retardant TDCPP on normal human corneal epithelial cells: Implications for human health.

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is one of the most detected organophosphorus flame retardants (OPFRs) in the environment, especially in indoor dust. Continuous daily exposure to TDCPP-containing dust may adversely impact human cornea. However, its detrimental effects on human corneal epithelium are largely unknown.

Effects of novel brominated flame retardant TBPH and its metabolite TBMEHP on human vascular endothelial cells: Implication for human health risks.

As a replacement for polybrominated diphenyl ethers, bis-(2-ethylhexyl) tetrabromophthalate (TBPH) is widely used as a novel flame retardant and has been detected in many environmental matrix including human blood. TBPH can be metabolized into mono-(2-ethyhexyl) tetrabromophthalate (TBMEHP) by carboxylesterase. However, their adverse effects on human vascular endothelium and their potential impacts on human cardiovascular disease are unknown.

Lead relative bioavailability in soils based on different endpoints of a mouse model.

Mouse is an acceptable animal model to measure lead (Pb) relative bioavailability (RBA) in contaminated soils; however, there is a lack of comparisons among Pb-RBA measurements based on different endpoints and dosing approaches. In this study, 12 soils (47.8-8123mg Pbkg) were assessed for Pb-RBA using Pb accumulation in mouse liver, kidneys, and/or femur following a 10-d steady state soil dose via diet, with 6 soils being measured using mouse bioassays with area under the mouse blood Pb concentration time curve (AUC) following a single gavaged dose as the endpoint.

Influence of pollution control on lead inhalation bioaccessibility in PM2.5: A case study of 2014 Youth Olympic Games in Nanjing.

Pollution controls were implemented to improve the air quality for the 2014 Youth Olympic Games (YOG) in Nanjing. To investigate the influence of pollution control on Pb inhalation bioaccessibility in PM2.5, samples were collected before, during, and after YOG.

Molecular mechanisms of dust-induced toxicity in human corneal epithelial cells: Water and organic extract of office and house dust.

Human corneal epithelial (HCE) cells are continually exposed to dust in the air, which may cause corneal epithelium damage. Both water and organic soluble contaminants in dust may contribute to cytotoxicity in HCE cells, however, the associated toxicity mechanisms are not fully elucidated. In this study, indoor dust from residential houses and commercial offices in Nanjing, China was collected and the effects of organic and water soluble fraction of dust on primary HCE cells were examined.

Advances in in vitro methods to evaluate oral bioaccessibility of PAHs and PBDEs in environmental matrices.

Cleanup goals for sites contaminated with persistent organic pollutants (POPs) are often established based on total contaminant concentrations. However, mounting evidence suggests that understanding contaminant bioavailability in soils is necessary for accurate assessment of contaminant exposure to humans via oral ingestion pathway. Animal-based in vivo tests have been used to assess contaminant bioavailability in soils; however, due to ethical issues and cost, it is desirable to use in vitro assays as alternatives.

Mechanisms of housedust-induced toxicity in primary human corneal epithelial cells: Oxidative stress, proinflammatory response and mitochondrial dysfunction.

Human cornea is highly susceptible to damage by dust. Continued daily exposure to housedust has been associated with increasing risks of corneal injury, however, the underlying mechanism has not been elucidated. In this study, a composite housedust sample was tested for its cytotoxicity on primary human corneal epithelial (PHCE) cells, which were exposed to dust at 5-320μg/100μL for 24h.

In vitro bioaccessibility and in vivo relative bioavailability in 12 contaminated soils: Method comparison and method development.

Previous studies have established in vivo-in vitro correlations (IVIVC) between arsenic (As) relative bioavailability (RBA) and bioaccessibility in contaminated soils. However, their ability to predict As-RBA in soils outside the models is unclear. In this study, As bioaccessibility and As-RBA in 12 As-contaminated soils (22.

Toxic metals in children's toys and jewelry: coupling bioaccessibility with risk assessment.

A total of 45 children's toys and jewelry were tested for total and bioaccessible metal concentrations. Total As, Cd, Sb, Cr, Ni, and Pb concentrations were 0.22-19, 0.

In vivo bioavailability and in vitro bioaccessibility of perfluorooctanoic acid (PFOA) in food matrices: correlation analysis and method development.

Food is a major source of human exposure to perfluorooctanoic acid (PFOA), however, PFOA bioavailability in food has not been studied. An in vivo mouse model and three in vitro methods (unified BARGE method, UBM; physiologically based extraction test, PBET; and in vitro digestion method, IVD) were used to determine the relative bioavailability and bioaccessibility of PFOA in the presence of 17 foods. PFOA was mixed with foods of different nutritional compositions and fed to mice over a 7-d period.

Activated charcoal based diffusive gradients in thin films for in situ monitoring of bisphenols in waters.

Widespread use of bisphenols (BPs) in our daily life results in their elevated concentrations in waters and the need to study their environmental impact, which demands reliable and robust measurement techniques. Diffusive gradients in thin films (DGT) is an in situ passive sampling approach which provides time-integrated data. In this study we developed a new methodology, based on DGT with activated charcoal (AC) as a binding agent, for measuring three BPs (BPA, BPB, and BPF) which incorporated and tested its performance characteristics.

Tenax as sorption sink for in vitro bioaccessibility measurement of polycyclic aromatic hydrocarbons in soils.

Physiologically based in vitro methods have been developed to measure bioaccessibility of organic contaminants in soils. However, bioaccessibility of hydrophobic organic contaminants (HOCs) can be underestimated by in vitro tests if gastrointestinal (GI) solution fails to provide sufficient sorption sink for HOCs. To circumvent this drawback, Tenax was included in GI solution as sorption sink to trap mobilized HOCs and maintain the desorption gradient between soil and GI solution.

High Phosphorylation Status of AKT/mTOR Signal in DESI2-Reduced Pancreatic Ductal Adenocarcinoma.

Desumoylating isopeptidase 2 (DESI2) is a recently identified protein with unclear functions. In this study, a total of 132 tissue samples of pancreatic ductal adenocarcinoma and 73 samples of pancreatic normal tissues were explored to assess DESI2 expression and its implications to AKT/mTOR signal. Immunohistochemistry showed DESI2 expression is significantly decreased in cancer tissues versus normal tissues, presenting lowest level in poorly differentiated cancer.

Assessment of in vitro lead bioaccessibility in house dust and its relationship to in vivo lead relative bioavailability.

House dust samples containing 25-738 mg of Pb kg(-1) from 15 cities in China were assessed for in vitro Pb bioaccessibility and in vivo Pb relative bioavailability. On the basis of stable Pb isotope ratios, the Pb in dust samples mainly originated from coal combustion. Lead bioaccessibility was determined using gastric (GP) and intestinal phase (IP) of solubility bioaccessibility research consortium (SBRC), in vitro gastrointestinal (IVG), Deutsches Institut für Normunge.

Effects of storage temperature and duration on release of antimony and bisphenol A from polyethylene terephthalate drinking water bottles of China.

We investigated effects of storage temperature and duration on release of antimony (Sb) and bisphenol A (BPA) from 16 brands of polyethylene terephthalate (PET) drinking water bottles in China. After 1-week storage, Sb release increased from 1.88-8.

[Application of EMD and SPA algorithm in the detection of benzoyl peroxide addition in flour by spectroscopy].

In order to improve the accuracy of spectroscopy analysis and reduce the modeling wavelength numbers, empirical mode decomposition (EMD) and successive projections algorithm (SPA) were applied together in the measurement of benzoyl peroxide (BPO) additive amount in flour by near infrared spectroscopy. Spectra of flour samples into which BPO were added were collected. Firstly, EMD was implemented to eliminate the noise of original spectra, and then SPA was employed to select the characteristic wavelengths.