Transboundary health impacts of transported global air pollution and international trade.

Millions of people die every year from diseases caused by exposure to outdoor air pollution. Some studies have estimated premature mortality related to local sources of air pollution, but local air quality can also be affected by atmospheric transport of pollution from distant sources. International trade is contributing to the globalization of emission and pollution as a result of the production of goods (and their associated emissions) in one region for consumption in another region. The effects of international trade on air pollutant emissions, air quality and health have been investigated regionally, but a combined, global assessment of the health impacts related to international trade and the transport of atmospheric air pollution is lacking. Here we combine four global models to estimate premature mortality caused by fine particulate matter (PM2.5) pollution as a result of atmospheric transport and the production and consumption of goods and services in different world regions. We find that, of the 3.45 million premature deaths related to PM2.5 pollution in 2007 worldwide, about 12 per cent (411,100 deaths) were related to air pollutants emitted in a region of the world other than that in which the death occurred, and about 22 per cent (762,400 deaths) were associated with goods and services produced in one region for consumption in another. For example, PM2.5 pollution produced in China in 2007 is linked to more than 64,800 premature deaths in regions other than China, including more than 3,100 premature deaths in western Europe and the USA; on the other hand, consumption in western Europe and the USA is linked to more than 108,600 premature deaths in China. Our results reveal that the transboundary health impacts of PM2.5 pollution associated with international trade are greater than those associated with long-distance atmospheric pollutant transport.

Change of motifs in C. elegans reveals developmental principle of neural network.

Revealing the organizing principles of developing neural networks is a difficult but significant task in neuroscience. As a creature with a rather compact and well-studied neural network, C. elegans is an ideal subject for neuroscience study. However, the researches on its developing neural network remain challenging. The changes in specific properties of neural network across development may uncover part of its principles. Motif is a typical structure property that can be well applied to various complex networks. Here, we study the motif changes in C. elegans neural network across development. By counting the occurrence number of all three-node subgraph motif structures in its neural network at different stages of C. elegans development, along with those in corresponding random networks, we determine which of these structures are motifs for C. elegans, finding out the regular changes of motifs during its development. Combined with the potential function of these subgraph motifs and synaptic information, we gain insight into the organizing principle of neural network during development, which may increase our understanding of neuroscience and inspire the construction of artificial neural network.

Discovery of triterpenoids as potent dual inhibitors of pancreatic lipase and human carboxylesterase 1.

Pancreatic lipase (PL) is a well-known key target for the prevention and treatment of obesity. Human carboxylesterase 1A (hCES1A) has become an important target for the treatment of hyperlipidaemia. Thus, the discovery of potent dual-target inhibitors based on PL and hCES1A hold great potential for the development of remedies for treating related metabolic diseases. In this study, a series of natural triterpenoids were collected and the inhibitory effects of these triterpenoids on PL and hCES1A were determined using fluorescence-based biochemical assays. It was found that oleanolic acid (OA) and ursolic acid (UA) have the excellent inhibitory effects against PL and hCES1A, and highly selectivity over hCES2A. Subsequently, a number of compounds based on the OA and UA skeletons were synthesised and evaluated. Structure-activity relationship (SAR) analysis of these compounds revealed that the acetyl group at the C-3 site of UA (compound 41) was very essential for both PL and hCES1A inhibition, with IC50 of 0.75 µM and 0.014 µM, respectively. In addition, compound 39 with 2-enol and 3-ketal moiety of OA also has strong inhibitory effects against both PL and hCES1A, with IC50 of 2.13 µM and 0.055 µM, respectively. Furthermore, compound 39 and 41 exhibited good selectivity over other human serine hydrolases including hCES2A, butyrylcholinesterase (BChE) and dipeptidyl peptidase IV (DPP-IV). Inhibitory kinetics and molecular docking studies demonstrated that both compounds 39 and 41 were effective mixed inhibitors of PL, while competitive inhibitors of hCES1A. Further investigations demonstrated that both compounds 39 and 41 could inhibit adipocyte adipogenesis induced by mouse preadipocytes. Collectively, we found two triterpenoid derivatives with strong inhibitory ability on both PL and hCES1A, which can be served as promising lead compounds for the development of more potent dual-target inhibitors targeting on PL and hCES1A.

Spike signal transmission between modules and the predictability of spike activity in modular neuronal networks.

Modularity is a common feature of the nervous system across species and scales. Although it has been qualitatively investigated in network science, very little is known about how it affects spike signal transmission in neuronal networks at the mesoscopic level. Here, a neuronal network model is built to simulate dynamic interactions among different modules of neuronal networks. This neuronal network model follows the organizational principle of modular structure. The neurons can generate spikes like biological neurons, and changes in the strength of synaptic connections conform to the STDP learning rule. Based on this neuronal network model, we first quantitatively studied whether and to what extent the connectivity within and between modules can affect spike signal transmission, and found that spike signal transmission heavily depends on the connectivity between modules, but has little to do with the connectivity within modules. More importantly, we further found that the spike activity of a module can be predicted according to the spike activities of its adjacent modules through building a resting-state functional connectivity matrix.

Controlling the organization and stretchability of poly(3-butylthiophene) spherulites.

In this work, we report a simple strategy to readily prepare poly(3-butylthiophene) (P3BT) films with patterned spherulites by brushing the P3BT film surface and annealing the film with carbon disulfide (CS2) vapor. The spherulites nucleated preferentially at the mechanically scratched areas over the unscratched region of the film. The ridge (formed at the side of the scratch) hinders the diffusion of the P3BT molecules, promoting the aggregation and nucleation of P3BT along the ridge to form spherulites upon the CS2 vapor-annealing. The sizes of the ridge and the scratch have no effect on the nucleation and crystallization of the patterned spherulites. We evaluated the crack formation of the P3BT films with patterned spherulites in response to mechanical stretching along different directions. When the stretching direction was parallel to the scratching direction, cracks appeared preferentially at the boundary between the ordered spherulites. In contrast, cracks occurred first at the boundary of stochastic nucleated spherulites located away from the patterned spherulites, when the stretching direction was perpendicular to the scratching direction. The patterned spherulites with regulated mechanical properties may find applications in the design and fabrication of stretchable organic optoelectronic devices with enhanced stability and durability.

Realizing Dendrite-Free Lithium Deposition with a Composite Separator.

A dendrite-free Li deposition strategy is developed with a composite separator of MnCO3 coated porous polypropylene. Mn2+ ions are preferentially reduced to form Mn nanoparticles on Li anodes, which helped to reduce the nucleation overpotential and achieve a dendrite-free deposition of Li bulky grains. When MnCO3 contacts the Li metal anode directly, an in situ artificial solid electrolyte interphase passivating layer was created from the reaction of Li metal, MnCO3 and liquid electrolyte. Li metal anodes show significantly improved stability for more than 2000 h of plating/stripping in Li||Li symmetric cells. The homemade ultrathin Li films on Cu foils (Li@Cu), obtained by electrochemical Li deposition with PP/MnCO3 separators, give enhanced cycling stability in LFP||Li@Cu cells. Combined with gel polymer electrolyte, the cycling stability of quasi-solid-state LFP||Li@Cu was further improved. This strategy for dendrite-free deposition via a composite separator provides a low-cost but efficient choice for alkaline metal batteries.

Analysis of reflux as the aetiology of laryngeal dysplasia progression through a matched case-control study.

OBJECTIVES: Laryngeal dysplasia (LD) is a precancerous lesion of the larynx. In this study, the laryngeal tissue of patients with laryngeal dysplasia was taken as the research object, and the aetiology of reflux was analysed. METHOD: Patients with laryngeal dysplasia after surgery were selected as our subjects. The levels of pepsin, enterokinase and bilirubin in laryngeal tissue samples of the two groups were detected by immunohistochemical method. RESULTS: The OR values (95% CI) of pepsin, enterokinase and bilirubin were 0.67 (0.19-2.36), 0.80 (0.22-2.98) and 1.33 (0.30-5.96), respectively, in the univariate analysis. Besides, in the multivariate analysis, the OR values (95% CI) of pepsin, enterokinase and bilirubin were 0.57 (0.14-2.30), 0.73 (0.18-2.92) and 1.40 (0.30-6.53), respectively. CONCLUSION: Larger sample size should be applied to prospective studies on whether reflux is a risk factor for laryngeal cancer.

Investigation on the Copolymer Electrolyte of Poly(1,3-dioxolane-co-formaldehyde).

A series of copolymers are prepared via cationic ring-opening polymerization with 1,3-dioxolane (DOL) and trioxymethylene (TOM) as monomers. The crystallization behaviors of the copolymers can be suppressed by adjusting the ratio of DOL/TOM. With LiBF4 as a source for a BF3 initiator, copolymer electrolytes (CPEs) can be prepared in situ inside cells without needing nonelectrolyte catalysts or initiators. The ionic conductivities and Li+ diffusion coefficients ( D Li + ) of the CPEs increase with a decreasing DOL/TOM ratio in a certain range. The CPE with a DOL/TOM ratio of 8/2 has the highest ionic conductivity as well as D Li + and shows excellent interfacial compatibility with lithium (Li) metal anodes. Li-Li symmetric cells can be uniformly plated/stripped for more than 1200 h. Furthermore, LiFePO4 -Li cells with 8/2-CPE display stable cycling performance for over 400 cycles. This strategy is a promising approach for the preparation of high-performance polymer electrolytes and is sure to promote their application in Li metal batteries.

Mapping the binding site of the P2X receptor antagonist PPADS reveals the importance of orthosteric site charge and the cysteine-rich head region.

ATP is the native agonist for cell-surface ligand-gated P2X receptor (P2XR) cation channels. The seven mammalian subunits (P2X1-7) form homo- and heterotrimeric P2XRs having significant physiological and pathophysiological roles. Pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) is an effective antagonist at most mammalian P2XRs. Lys-249 in the extracellular domain of P2XR has previously been shown to contribute to PPADS action. To map this antagonist site, we generated human P2X1R cysteine substitutions within a circle centered at Lys-249 (with a radius of 13 Å equal to the length of PPADS). We hypothesized that cysteine substitutions of residues involved in PPADS binding would (i) reduce cysteine accessibility (measured by MTSEA-biotinylation), (ii) exhibit altered PPADS affinity, and (iii) quench the fluorescence of cysteine residues modified with MTS-TAMRA. Of the 26 residues tested, these criteria were met by only four (Lys-70, Asp-170, Lys-190, and Lys-249), defining the antagonist site, validating molecular docking results, and thereby providing the first experimentally supported model of PPADS binding. This binding site overlapped with the ATP-binding site, indicating that PPADS sterically blocks agonist access. Moreover, PPADS induced a conformational change at the cysteine-rich head (CRH) region adjacent to the orthosteric ATP-binding pocket. The importance of this movement was confirmed by demonstrating that substitution introducing positive charge present in the CRH of the hP2X1R causes PPADS sensitivity at the normally insensitive rat P2X4R. This study provides a template for developing P2XR subtype selectivity based on the differences among the mammalian subunits around the orthosteric P2XR-binding site and the CRH.

SNORD89 promotes stemness phenotype of ovarian cancer cells by regulating Notch1-c-Myc pathway.

BACKGROUND: Ovarian cancer is the leading cause of death in gynecological cancer. Cancer stem cells (CSCs) contribute to the occurrence, progression and resistance. Small nucleolar RNAs (SnoRNAs), a class of small molecule non-coding RNA, involve in the cancer cell stemness and tumorigenesis. METHODS: In this study, we screened out SNORNAs related to ovarian patient's prognosis by analyzing the data of 379 cases of ovarian cancer patients in the TCGA database, and analyzed the difference of SNORNAs expression between OVCAR-3 (OV) sphere-forming (OS) cells and OV cells. After overexpression or knockdown SNORD89, the expression of Nanog, CD44, and CD133 was measured by qRT-PCR or flow cytometry analysis in OV, CAOV-3 (CA) and OS cells, respectively. CCK-8 assays, plate clone formation assay and soft agar colony formation assay were carried out to evaluate the changes of cell proliferation and self-renewal ability. Scratch migration assay and trans-well invasion analysis were used for assessing the changes of migration and invasion ability. RESULTS: High expression of SNORD89 indicates the poor prognosis of ovarian cancer patients and was associated with patients' age, therapy outcome. SNORD89 highly expressed in ovarian cancer stem cells. The overexpression of SNORD89 resulted in the increased stemness markers, S phase cell cycle, cell proliferation, invasion and migration ability in OV and CA cells. Conversely, these phenomena were reversed after SNORD89 silencing in OS cells. Further, we found that SNORD89 could upregulate c-Myc and Notch1 expression in mRNA and protein levels. SNORD89 deteriorates the prognosis of ovarian cancer patients by regulating Notch1-c-Myc pathway to promote cell stemness and acts as an oncogene in ovarian tumorigenesis. Consequently, SNORD89 can be a novel prognostic biomarker and therapeutic target for ovarian cancer.

Lactic acid induces lactate transport and glycolysis/OXPHOS interconversion in glioblastoma.

The Warburg effect is a dominant phenotype of most tumor cells. Recent reports have shown that the Warburg effect can be reprogrammed by the tumor microenvironment. Lactic acidosis and glucose deprivation are the common adverse microenvironments in solid tumor. The metabolic reprogramming induced by lactic acid and glucose deprivation remains to be elucidated in glioblastoma. Here, we show that, under glucose deprivation, lactic acid can preserve high ATP levels and resist cell death in U251 cells. At the same time, we find that MCT1 and MCT4 are significantly highly expressed. The metabolic regulation factor HIF-1α decreased and C-MYC increased. Nuclear respiratory factor 1 (NRF1) and oxidative phosphorylation (OXPHOS)-related proteins (NDUFB8, ND1) are all distinctly increased. Therefore, lactic acid can induce lactate transport and convert the dominant Warburg effect to OXPHOS. Through bioinformatics analysis, the high expression of HIF-1α, MCT1 or MCT4 indicate a poor prognosis in glioblastoma. In addition, in glioblastoma tissue, HIF-1α, MCT4 and LDH are highly expressed in the interior region, and their expression is decreased in the lateral region. MCT1 can not be detected in the interior region and is highly expressed in the lateral region. Hence, different regions of glioblastoma have diverse energy metabolic pathways. Glycolysis occurs mainly in the interior region and OXPHOS in the lateral region. In general, lactic acid can induce regional energy metabolic reprogramming and assist tumor cells to adapt and resist adverse microenvironments. This study provides new ideas for furthering understanding of the metabolic features of glioblastoma. It may promote the development of new therapeutic strategies in GBM.

Duck enteritis virus activates CaMKKß-AMPK to trigger autophagy in duck embryo fibroblast cells via increased cytosolic calcium.

BACKGROUND: The results of our previous study showed that impaired cellular energy metabolism contributes to duck enteritis virus-induced autophagy via the 5`-adenosine monophosphate-activated protein kinase (AMPK)/tuberous sclerosis complex 2/mammalian target of rapamycin pathway in duck embryo fibroblast (DEF) cells. However, it remains unknown whether any other underlying mechanisms of AMPK activation are involved in autophagy induction. METHODS: The activity of CaMKKß and AMPK in DEF cells infected with DEV were evaluated.The Effect of inhibitory activity of CaMKKß on DEV-induced autophagy was investigated. In addtion to, the cytosolic calcium level in DEF cells infected with DEV were evaluated.The Effect of inhibitory cytosolic calcium level on DEV-induced autophagy was investigated. RESULTS: In this study, duck enteritis virus (DEV) infection activated CaMKKß and its substrate molecule AMPK at 36, 48, and 60 h post-infection (hpi). STO-609, a CaMKKß inhibitor, or CaMKKß siRNA significantly inhibited the activation of DEV to AMPK, LC3I to LC3II transformation, and GFP-LC3 puncta distribution. In addition, inhibition of CaMKKß activity also significantly reduced progeny DEV titer and gB protein expression. Besides, cytosolic calcium (Ca2+) was higher in DEV-infected cells than mock controls at 36, 48, and 60 hpi, respectively. Treatment of DEV-infected cells with 1,2-Bis (2-aminophenoxy) ethane-N, N, N', N-tetraacetic acid (BAPTA-AM) significantly reduced intracellular Ca2+ ion concentrations, as well as CaMKKß and AMPK activities, and subsequent autophagy, in addition to viral protein synthesis and viral titer. CONCLUSIONS: These results showed that elevated [Ca2+]cyto-mediated activation of CaMKKß managed the activation of AMPK, which then positively regulated autophagy, thereby providing further insight into DEV-host interactions.

Comparative genetic analysis and pathological characteristics of goose parvovirus isolated in Heilongjiang, China.

BACKGROUND: Goose parvovirus (GPV) causes acute enteritis, hepatitis, myocarditis and high morbidity and mortality in geese and ducks. GPV H strain was isolated from a Heilongjiang goose farm where the geese were showing signs of hemorrhage in the brain, liver, and intestinal tract. In this study, we explored the genetic diversity among waterfowl parvovirus isolates and the pathological characteristics of GPV H in Shaoxing ducklings. METHODS: The complete capsid protein (VP) and non-structural (NS) sequences of the isolated H strain were sequenced, and phylogenetic trees of VP and NS were constructed in MEGA version 5.05 using the neighbor-joining method. Three-day-old Shaoxing ducklings were inoculated with GPV and were euthanized at 1, 2, 4, 6, and 8 days post-inoculation (PI), and their organs were removed and collected. The organs of 6-day PI ducklings were fixed in formalin, embedded in paraffin, sectioned for histology, stained with HE and analyzed for pathological lesions. The distribution of the GPV H strain in the tissues of the inoculated ducklings was detected using the polymerase chain reaction (PCR) method. RESULTS: Genetic analysis of the NS and VP genes indicated that the H strain was closely related to strains circulating in China during 1999-2014, and the nucleic acid identity of those strains was 98%-99%. Classical symptoms were observed in the inoculated ducklings. GPV remained in many tissues and replicated in a majority of the tissues, leading to histopathological lesions in four tissues. CONCLUSIONS: We first reported the distribution and histopathological lesions of a Chinese strain of GPV in infected shaoxing ducklings. This H strain was moderate pathogenic for Shaoxing ducklings.

Effects of ultrasonication on the interfacial interactions between poly(3-hexylthiophene) and graphene oxide.

The interactions between poly(3-hexylthiophene) (P3HT) and graphene oxide (GO) have endowed the P3HT/GO composite with excellent properties. Controlling these interactions is important to improve the performance of P3HT-based devices. In this work, ultrasonication was used to regulate the nanostructures of P3HTs (high Mw and low Mw), and further strongly affected the interactions between P3HTs and GO. Atomic force microscopy (AFM), UV-vis absorption spectroscopy, Raman spectroscopy, and grazing incidence X-ray diffraction (GIXRD) were used to study the effects of ultrasonication on the interfacial interactions between P3HTs and GO. With prolonged ultrasonication time, the molecular order of high Mw P3HT nanofibers increased, but that of low Mw P3HT nanofibers decreased. Molecular order is a crucial factor affecting the interfacial interactions between P3HTs and GO, and the amounts of P3HT nanofibers absorbed onto the GO surface increased with the decreased molecular order of the nanofibers. After absorption, the overall molecular order of P3HT/GO composite nanofibers was determined by the nanofibers absorbed onto the GO surface and the nanofibers nucleated by GO. Compared with the molecular order of the nanofibers before absorption, the overall molecular order of the composites with high Mw P3HT increased, but that of composites with low Mw P3HT decreased. These findings can help to understand and modulate the interactions between P3HT nanofibers and GO to provide more information in the field of interfacial engineering of conjugated polymers in polymer-based devices.

Sonocrystallization of poly(3-hexylthiophene) in a marginal solvent.

The application of ultrasonication to P3HT in anisole can dramatically affect the crystallization of P3HT. The ultrasonication conditions were modulated by varying the ultrasonication time, ultrasonication power and ultrasonication temperature. Ultrasonicating at the dissolution temperature (85 °C) causes the concentration of the P3HT solution to fluctuate. When fixing the ultrasonication power at 100 W and ultrasonication time at 3 min, for P3HT crystallized in solution at 16 °C, the crystallization kinetics of ultrasonicated P3HT is slower than that of pristine P3HT. The nanofiber aggregation density and crystallinity of ultrasonicated P3HT are lower than those of pristine P3HT, and the nanofiber aggregation size is larger. For P3HT crystallized in solution at 20 °C, the crystallization kinetics, nanofiber morphology and crystallinity of ultrasonicated P3HT are similar to those of pristine P3HT. For P3HT crystallized in solution at 26 °C, the crystallization kinetics of ultrasonicated P3HT is faster than that of pristine P3HT, the nanofiber aggregation size is larger, and the crystallinity is higher. Fixing the crystallization temperature at 16 °C and varying the ultrasonication time and ultrasonication power can effectively modulate the crystallization kinetics of P3HT. When the P3HT solution is ultrasonicated at the crystallization temperature (16 °C), in addition to fluctuations in the concentration, ultrasonication promotes the disentanglement of P3HT chains. The combination of the two effects of ultrasonication is more beneficial for the crystallization of P3HT when solvophobic forces exist in a marginal solvent.

A novel endoscopic surgery for dysphagia after stroke.

BACKGROUND: Dysphagia is a common complication in stroke patients, which severely affects quality of life. This study aimed to evaluate the effectiveness and safety of temperature-controlled plasma radiofrequency (coblation)-assisted endoscopic cricopharyngeal myotomy (CAECPM) for the treatment sustained (>6 months) dysphagia in stroke patients. METHODS: This retrospective case-control study included a total of 24 stroke patients with sustained dysphagia, who were either treated with transcervical cricopharyngeal myotomy (CPM) (n = 16) or CAECPM (n = 12). The patients' swallowing function was evaluated by the Chinese version of the swallow quality-of-life questionnaire (CSWAL-QOL), and dysphagia and aspiration was evaluated using the videofluoroscopic swallowing study (VFSS) swallowing (VFSS-SWAL) score and VSSF aspiration (VFSS-ASPI) score. In each patient, esophageal pressure and complications were also recorded. RESULTS: The CSWAL-QOL score was increased and the VFSS-SWAL and VFSS-ASPI scores were reduced after CAECPM treatment. The upper esophageal sphincter pressure was significantly reduced after CAECPM. Only 1 of 12 (8.3%) patients had subcutaneous and mediastinal emphysema, and 2 patients had gastric regurgitation. CONCLUSION: This exploratory study demonstrates that CAECPM is worth further investigation for dysphagia after stroke. CAECPM may be an effective and safe treatment for sustained dysphagia in stroke patients. Larges and prospective studies are required to validate these results.

1,2,3,4-Bis(p-methylbenzylidene sorbitol) accelerates crystallization and improves hole mobility of poly(3-hexylthiophene).

The addition of 1,2,3,4-bis(p-methylbenzylidene sorbitol) (MDBS) does not change the nucleation mechanism or the crystal form of poly(3-hexylthiophene) (P3HT), but its presence increases the crystallization temperature (T c) of P3HT, decreases the crystallization half-time (t 1/2) and accelerates P3HT crystallization, which indicates that MDBS is an effective nucleating agent for P3HT. An acceleration of P3HT crystallization by the addition of MDBS decreases the crystalline size and crystallinity of P3HT, and enhances the connectivity between ordered regions of P3HT, leading to the hole mobility rising from 1.99 × 10(-6) to 7.57 × 10(-5) cm(2) V(-1)s(-1) in P3HT:PCBM blend based hole-only devices with sandwich configurations. Our results suggest that accelerating P3HT crystallization by adding a nucleating agent might be an important factor to improve the hole mobility and balance the electron and hole mobility in a photovoltaic blend.

Revealing the hidden health costs embodied in Chinese exports.

China emits a considerable amount of air pollutants when producing goods for export. Previous efforts have emphasized the magnitude of export-related emissions; however, their health consequences on the Chinese population have not been quantified. Here, we present an interdisciplinary study to estimate the health impact of export-related air pollution. The results show that export-related emissions elevated the annual mean population weighted PM2.5 by 8.3 µg/m(3) (15% of the total) in 2007, causing 157,000 deaths and accounting for 12% of the total mortality attributable to PM2.5-related air pollution. Compared to the eastern coastal provinces, the inner regions experience much larger export-related health losses relative to their economic production gains, owing to huge inter-regional disparities in export structures and technology levels. A shift away from emission-intensive production structure and export patterns, especially in inner regions, could significantly help improve national exports while alleviating the inter-regional cost-benefit inequality. Our results provide the first quantification of health consequences from air pollution related to Chinese exports. The proposed policy recommendations, based on health burden, economic production gains, and emission analysis, would be helpful to develop more sustainable and effective national and regional export strategies.

Endoscopic upper airway evaluation in obstructive sleep apnea: Mueller's maneuver versus simulation of snoring.

PURPOSE: This study aimed to compare fiberoptic nasopharyngoscopy during Mueller's maneuver (FNMM) with fiberoptic nasopharyngoscopy with simulation of snoring (FNSS) for upper airway (UA) assessment in patients with obstructive sleep apnea and hypopnea syndrome. We also investigated the relationship between daytime endoscopic examinations and nocturnal pressure measurements. METHODS: We conducted a prospective, case-series study at Peking Union Medical College Hospital. All patients were evaluated by daytime FNMM and FNSS. The retropalatal and retroglossal regions were continuously video recorded during quiet breathing, FNMM, and FNSS. We calculated the narrowing rate and determined the level of obstruction and pattern of collapse (lateral, anterior-posterior, or concentric). Patients also underwent nocturnal pressure measurements to identify obstruction sites. RESULTS: Ninety-two patients were enrolled. FNMM and FNSS detected retropalatal obstruction in every case. Fifty-six and 38 patients had retroglossal obstruction detected by FNMM and FNSS, respectively. There was diagnostic agreement between FNMM and FNSS in 72 patients when diagnosing retroglossal obstruction, but the patterns of collapse were different using each technique. Pressure measurements showed that lower apnea and hypopnea index (AHI) and the proportion of lower AHI were significantly lower in the isolated retropalatal obstruction group than in the combined obstruction group diagnosed with either FNMM or FNSS (p < 0.01). CONCLUSIONS: Daytime FNMM and FNSS are reliable for evaluating the level of obstruction and pattern of UA collapse, and correlate with sleep study findings. FNSS may provide some different information regarding patterns of collapse and retroglossal obstruction from FNMM. Both techniques are helpful for determining surgical strategies.

Development of database of real-world diesel vehicle emission factors for China.

A database of real-world diesel vehicle emission factors, based on type and technology, has been developed following tests on more than 300 diesel vehicles in China using a portable emission measurement system. The database provides better understanding of diesel vehicle emissions under actual driving conditions. We found that although new regulations have reduced real-world emission levels of diesel trucks and buses significantly for most pollutants in China, NOx emissions have been inadequately controlled by the current standards, especially for diesel buses, because of bad driving conditions in the real world. We also compared the emission factors in the database with those calculated by emission factor models and used in inventory studies. The emission factors derived from COPERT (Computer Programmer to calculate Emissions from Road Transport) and MOBILE may both underestimate real emission factors, whereas the updated COPERT and PART5 (Highway Vehicle Particulate Emission Modeling Software) models may overestimate emission factors in China. Real-world measurement results and emission factors used in recent emission inventory studies are inconsistent, which has led to inaccurate estimates of emissions from diesel trucks and buses over recent years. This suggests that emission factors derived from European or US-based models will not truly represent real-world emissions in China. Therefore, it is useful and necessary to conduct systematic real-world measurements of vehicle emissions in China in order to obtain the optimum inputs for emission inventory models.