VirGrapher: a graph-based viral identifier for long sequences from metagenomes.

Viruses are the most abundant biological entities on earth and are important components of microbial communities. A metagenome contains all microorganisms from an environmental sample. Correctly identifying viruses from these mixed sequences is critical in viral analyses. It is common to identify long viral sequences, which has already been passed thought pipelines of assembly and binning. Existing deep learning-based methods divide these long sequences into short subsequences and identify them separately. This makes the relationships between them be omitted, leading to poor performance on identifying long viral sequences. In this paper, VirGrapher is proposed to improve the identification performance of long viral sequences by constructing relationships among short subsequences from long ones. VirGrapher see a long sequence as a graph and uses a Graph Convolutional Network (GCN) model to learn multilayer connections between nodes from sequences after a GCN-based node embedding model. VirGrapher achieves a better AUC value and accuracy on validation set, which is better than three benchmark methods.

Establishment and Validation of Risk Prediction Model for Postpartum Hemorrhage for Pregnant Women ≥35 Years of Age in Natural Delivery.

Context: After the age of 35, women's fertility and physical function gradually decline, and this can significantly increase the risks of postpartum hemorrhage (PPH) after delivery. Sufficient exploration of prenatal indicators of PPH for older pregnant women are still lacking. Objective: The study intended to examine the factors influencing postpartum hemorrhage (PPH) in natural delivery for pregnant women ≥35 years of age and to establish a reliable risk-prediction model. Design: The research team performed a retrospective study. Setting: The study took place at Suzhou Ninth People's Hospital in Suzhou, Jiangsu Province, China. Participants: Participants were 351 pregnant women who had undergone a prenatal examination and vaginal delivery at the hospital between January 2019 and October 2022. Groups: The research team divided participants into two groups: (1) a PPH group, with 52 participants who experienced PPH, and (2) a non-PPH group, with 299 participants who had no PPH. Outcome Measures: The research team: (1) conducted single-factor analysis of the two groups' demographic and clinical characteristics; (2) performed multivariate logistic regression analysis to find the factors influencing PPH; (3) built a risk-prediction model based on the results; and (4) analyzed the model's identification ability, proofreading ability, and clinical applicability using a goodness-of-fit test, a receiver operating characteristic (ROC) curve, a calibration curve, and a decision curve. The team used the SPSS 22.0 and R software for statistical analysis. Results: The incidence of PPH was 14.81%, for the 52 out of 351 participants. The PPH group's age (P < .001), rate of pregnancy-induced hypertension (P = .008), length of the third stage of labor (P = .001), and newborn's birth weight (P < .001) were significantly greater and its FIB before delivery was significantly lower than those of the non-PPH group. The high expression of fibrinogen (FIB) before delivery indicates it may be a protective factor against PPH. The multivariate analysis indicated that a greater age (P = .013), pregnancy-induced hypertension (P = .002), a low FIB level (P < .001), a long third stage of labor (P = .012), and a low birth weight for the newborn (P = .006) were all significantly related to PPH. The research team validated the risk-prediction model, which indicated that the model had good recognition ability (AUC = 0.873). The optimal critical value was 34%, and the sensitivity and specificity were 0.869 and 0.826, respectively. In the comparison of the PPH value that the model predicted and the participants' actual PPH incidence (U = -0.006, Brier = 0.089), the deviation of the model wasn't statistically significant (χ2 = 5.964, P = .651). The analysis of the decision curve found that the net benefits for pregnant women ≥35 years of age were higher than those of the other two extreme curves, showing that the model was clinically effective. Conclusions: The PPH risk-prediction model for vaginal delivery for pregnant women ≥35 years of age showed that a greater age, pregnancy-induced hypertension, a lower prelabor FIB, a longer third stage of labor, and a higher birth weight for the newborn were significantly related to the incidence of PPH and that its use could be clinically helpful.

Vascular Endothelial Growth Factor Mediates the Sprouted Axonogenesis of Breast Cancer in Rat.

Nerve infiltration into the tumor is a common feature of the tumor microenvironment. The mechanisms of axonogenesis in breast cancer remain unclear. We hypothesized that vascular endothelial growth factor (VEGF), as well as nerve growth factor (NGF), is involved in the axonogenesis of breast cancer. A N-methyl-N-nitrosourea (MNU)-induced rat model of breast cancer was used to explore the presence of axonogenesis in breast tumor and the involvement of VEGF, as well as NGF, in the axonogenesis of breast tumor. Nerve infiltration into the tumor was found in MNU-induced rat model of breast cancer including the sensory and sympathetic nerve fibers. Nerve density was increased following the growth of tumor. The sensory neurons innervating the thoracic and abdominal mammary tumors peaked at T5 to T6 and L1 to L2 dorsal root ganglions, respectively. Either VEGF receptor inhibitor or antibody against VEGF receptor 2, as well as NGF receptor inhibitor, apparently decreased both the nerve density and vascular density of breast tumor. The reduced nerve density was correlated with the decreased vascular density induced by these treatments. In cultured dorsal root ganglion neurons, phosphatidylinositol 3 (PI3K)/Akt, extracellular signal-regulated protein kinase (ERK), and p38 inhibitors significantly attenuated VEGF-induced neurite elongation. These findings provide direct evidence that VEGF, as well as NGF, may control the axonogenesis of breast cancer.

Target Characterization of Kaempferol against Myocardial Infarction Using Novel In Silico Docking and DARTS Prediction Strategy.

Target identification is a crucial process for advancing natural products and drug leads development, which is often the most challenging and time-consuming step. However, the putative biological targets of natural products obtained from traditional prediction studies are also informatively redundant. Thus, how to precisely identify the target of natural products is still one of the major challenges. Given the shortcomings of current target identification methodologies, herein, a novel in silico docking and DARTS prediction strategy was proposed. Concretely, the possible molecular weight was detected by DARTS method through examining the protected band in SDS-PAGE. Then, the potential targets were obtained from screening and identification through the PharmMapper Server and TargetHunter method. In addition, the candidate target Src was further validated by surface plasmon resonance assay, and the anti-apoptosis effects of kaempferol against myocardial infarction were further confirmed by in vitro and in vivo assays. Collectively, these results demonstrated that the integrated strategy could efficiently characterize the targets, which may shed a new light on target identification of natural products.

Alkaline aided thermophiles pretreatment of waste activated sludge to increase short chain fatty acids production: Microbial community evolution by alkaline on hydrolysis and fermentation.

Adding alkaline into an anaerobic waste activated sludge (WAS) fermentation with thermophilic bacteria pretreatment could efficiently improve short-chain fatty acids (SCFAs) accumulation to 3550 ± 120 mg COD/L. The acidification rate in combined test was 21.2%, while that was 15.6% and 10.7% in sole thermophilic bacteria pretreatment and control tests respectively. Four distinct groups of microbes could be identified with noticeable shifts using the combined pretreatments, and tremendous effects were analyzed on organic content especially of the soluble proteins and SCFAs concentrations. Particularly, alkaline addition would significantly change the functional microbial structures, including the decrease of Caloramator with the function of thermophilic proteolytic and the increase of Acidobacteria TM7 and Petrimonas sp. The results above suggested that alkaline addition could decrease the hydrolytic substances consume by thermotolerance bacteria and final improve SCFAs accumulation in fermentation process.

In Situ Detection and Imaging of PFOS in Mouse Kidney by Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry.

Perfluorooctanesulfonic acid (PFOS) is an emerging environmental organic pollutant that has been widely used in daily life products in the last century. Numerous studies showed that the accumulation of PFOS in human through food chain would lead to various disease. However, there is currently no report about its in situ localization in the tissue. In present study, we aimed to develop a reproductive and less-cost method to quantitatively detect and determine the spatial distribution of PFOS in mouse kidney by matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) with a commercially available matrix. α-Cyano-4-hydroxycinnamic acid (CHCA) matrix was optimized for PFOS detection in MALDI-IMS analysis. Compared to other organic matrices, CHCA used in negative ion mode showed less background interference and enhanced MS signal intensity and high spatial resolution (80 µm) for PFOS analysis. The use of a CHCA matrix with an autospray system led to successful identification of the PFOS ion signals on the perfusion kidney tissue. The detection limit was at the µg/mL level, with direct visualization from a MS image. The developed method with the optimized parameters was successfully employed to obtain the PFOS spatial distribution in the kidney collected from mice after the PFOS exposure for 14 days. PFOS was mainly distributed in the kidney cortex region, which was consistent with the histological analysis results. Taken together, a rapid, economic, and efficient method was developed for PFOS detection by MALDI-IMS using a CHCA matrix. Mapping the distribution of PFOS by MALDI-IMS with a CHCA matrix provides an innovative approach for the analysis of environmental pollutants in animal or human tissues.

Integration of Metabolomics and Lipidomics Reveals Metabolic Mechanisms of Triclosan-Induced Toxicity in Human Hepatocytes.

Triclosan (TCS), an extensively used antimicrobial agent, has raised considerable concern due to its hepatocarcinogenic potential. However, previous hepatotoxicity studies primarily focused on the activation of specific intracellular receptors, the underlying mechanisms still warrant further investigation at the metabolic level. Herein, we applied metabolomics in combination with lipidomics to unveil TCS-related metabolic responses in human normal and cancerous hepatocytes. Endogenous and exogenous metabolites were analyzed for the identification of metabolic biomarkers and biotransformation products. In L02 normal cells, TCS exposure induced the up-regulation of purine metabolism and amino acid metabolism, caused lipid accumulation, and disturbed energy metabolism. These metabolic disorders in turn enhanced the overproduction of reactive oxygen species (ROS), leading to the alteration of antioxidant enzyme activities, down-regulation of endogenous antioxidants, and peroxidation of lipids. TCS-induced oxidative stress is thus considered to be one crucial factor for hepatotoxicity. However, in HepG2 cancer cells, TCS underwent fast detoxification through phase II metabolism, accompanied by the enhancement of energy metabolism and elevation of antioxidant defense system, which contributed to the potential effects of TCS on human hepatocellular carcinoma development. These different responses of metabolism between normal and cancerous hepatocytes provide novel and robust perspectives for revealing the mechanisms of TCS-triggered hepatotoxicity.

Oral administration of curcumin attenuates visceral hyperalgesia through inhibiting phosphorylation of TRPV1 in rat model of ulcerative colitis.

Background Curcumin has been reported to have anti-inflammatory and anti-nociceptive effects. The present study was designed to explore the potential therapeutic effects of curcumin on visceral hyperalgesia and inflammation in a rat model of ulcerative colitis. We observed the effects of orally administered curcumin on the disease activity index, histological change in colon, colorectal distension-induced abdominal withdrawal reflex, the expression of transient receptor potential vanilloid 1 (TRPV1) and phosphorylated TRPV1 in dextran sulfate sodium-induced colitis rats. In addition, a HEK293 cell line stably expressing human TRPV1 (hTRPV1) was used to examine the effects of curcumin on the change in membrane expression of TRPV1 induced by phorbol myristate acetate (a protein kinase C activator). Results Repeated oral administration of curcumin inhibited the increase in abdominal withdrawal reflex score induced by dextran sulfate sodium without affecting dextran sulfate sodium-induced histological change of colon and the disease activity index. A significant increase in colonic expression of TRPV1 and pTRPV1 was observed in dextran sulfate sodium-treated rats and this was reversed by oral administration of curcumin. TRPV1 expression in L6-S1 dorsal root ganglion was increased in the small- to medium-sized isolectin B4-positive non-peptidergic and calcitonin gene-related peptide-positive peptidergic neurons in dextran sulfate sodium-treated rats and oral administration of curcumin mitigated such changes. In the HEK293 cell line stably expressing hTRPV1, curcumin (1, 3 µm) inhibited phorbol myristate acetate-induced upregulation of membrane TRPV1. Conclusion Oral administration of curcumin alleviates visceral hyperalgesia in dextran sulfate sodium-induced colitis rats. The anti-hyperalgesic effect is partially through downregulating the colonic expression and phosphorylation of TRPV1 on the afferent fibers projected from peptidergic and non-peptidergic nociceptive neurons of dorsal root ganglion.

Persistent Organic Pollutants as Risk Factors for Obesity and Diabetes.

PURPOSE OF REVIEW: The rising prevalence of obesity and diabetes cannot be fully explained by known risk factors, such as unhealthy diet, a sedentary lifestyle, and family history. This review summarizes the available studies linking persistent organic pollutants (POPs) to obesity and diabetes and discusses plausible underlying mechanisms. RECENT FINDINGS: Increasing evidence suggest that POPs may act as obesogens and diabetogens to promote the development of obesity and diabetes and induce metabolic dysfunction. POPs are synthesized chemicals and are used widely in our daily life. These chemicals are resistant to degradation in chemical or biological processes, which enable them to exist in the environment persistently and to be bio-accumulated in animal and human tissue through the food chain. Increasingly, epidemiologic studies suggest a positive association between POPs and risk of developing diabetes. Understanding the relationship of POPs with obesity and diabetes may shed light on preventive strategies for obesity and diabetes.

Saline-induced changes of epicuticular waxy layer on the Puccinellia tenuiflora and Oryza sativa leave surfaces.

BACKGROUND: The epicuticular waxy layer of plant leaves enhances the extreme environmental stress tolerance. However, the relationship between waxy layer and saline tolerance was not established well. The epicuticular waxy layer of rice (Oryza sativa L.) was studied under the NaHCO3 stresses. In addition, strong saline tolerance Puccinellia tenuiflora was chosen for comparative studies. RESULTS: Scanning electron microscope (SEM) images showed that there were significant changes in waxy morphologies of the rice epicuticular surfaces, while no remarkable changes in those of P. tenuiflora epicuticular surfaces. The NaHCO3-induced morphological changes of the rice epicuticular surfaces appeared as enlarged silica cells, swollen corns-shapes and leaked salt columns under high stress. Energy dispersive X-ray (EDX) spectroscopic profiles supported that the changes were caused by significant increment and localization of [Na(+)] and [Cl(-)] in the shoot. Atomic absorption spectra showed that [Na(+)]shoot/[Na(+)]root for P. tenuiflora maintained stable as the saline stress increased, but that for rice increased significantly. CONCLUSION: In rice, NaHCO3 stress induced localization and accumulation of [Na(+)] and [Cl(-)] appeared as the enlarged silica cells (MSC), the swollen corns (S-C), and the leaked columns (C), while no significant changes in P. tenuiflora.

Optimized culture condition for enhancing lytic performance of waste activated sludge by Geobacillus sp. G1.

Hydrolysis is known as the rate-limiting step during waste activated sludge (WAS) digestion. The optimization of the culture conditions of Geobacillus sp. G1 for enhancing WAS hydrolysis was conducted in this study with uniform design and response surface methodology. Taking the lysis rate of Escherichia coli as the response, the Plackett-Burman design was used to screen the most important variables. Experimental results showed that the maximum predicted lysis rate of E. coli was 50.9% for 4 h treatment time with concentrations of skim milk, NaCl and NH4SO4 at 10.78, 4.36 and 11.28 g/L, respectively. The optimized dosage ratio of Geobacillus sp. G1 to WAS was 35%:65% (VG1:VWAS). Under this condition, soluble protein was increased to 695 mg chemical oxygen demand (COD)/L, which was 5.0 times higher than that obtained in the control (140 mg COD/L). The corresponding protease activity reached 1.1 Eu/mL. Scanning electron microscopy showed that abundant cells were apparently lysed with treatment of Geobacillus sp. G1.

Acceleration of the ocean warming from 1961 to 2022 unveiled by large-ensemble reanalyses.

Long-term changes in ocean heat content (OHC) represent a fundamental global warming indicator and are mostly caused by anthropogenic climate-altering gas emissions. OHC increases heavily threaten the marine environment, therefore, reconstructing OHC before the well-instrumented period (i.e., before the Argo floats deployment in the mid-2000s) is crucial to understanding the multi-decadal climate change in the ocean. Here, we shed light on ocean warming and its uncertainty for the 1961-2022 period through a large ensemble reanalysis system that spans the major sources of uncertainties. Results indicate a 62-year warming of 0.43 ± 0.08 W m-2, and a statistically significant acceleration rate equal to 0.15 ± 0.04 W m-2 dec-1, locally peaking at high latitudes. The 11.6% of the global ocean area reaches the maximum yearly OHC in 2022, almost doubling any previous year. At the regional scale, major OHC uncertainty is found in the Tropics; at the global scale, the uncertainty represents about 40% and 15% of the OHC variability, respectively before and after the mid-2000s. The uncertainty of regional trends is mostly affected by observation calibration (especially at high latitudes), and sea surface temperature data uncertainty (especially at low latitudes).

Insights into pollution characteristics and human health risks of plasticizer phthalate esters in shellfish species.

The ubiquitous application of phthalate esters (PAEs) as plasticizers contributes to high levels of marine pollution, yet the contamination patterns of PAEs in various shellfish species remain unknown. The objective of this research is to provide the first information on the pollution characteristics of 16 PAEs in different shellfish species from the Pearl River Delta (PRD), South China, and associated health risks. Among the 16 analyzed PAEs, 13 were identified in the shellfish, with total PAE concentrations ranging from 23.07 to 3794.08 ng/g dw (mean = 514.35 ng/g dw). The PAE pollution levels in the five shellfish species were as follows: Ostreidae (mean = 1064.12 ng/g dw) > Mytilus edulis (mean = 509.88 ng/g dw) > Babylonia areolate (mean = 458.14 ng/g dw) > Mactra chinensis (mean = 378.90 ng/g dw) > Haliotis diversicolor (mean = 335.28 ng/g dw). Dimethyl phthalate (DMP, mean = 69.85 ng/g dw), diisobutyl phthalate (DIBP, mean = 41.39 ng/g dw), dibutyl phthalate (DBP, mean = 130.91 ng/g dw), and di(2-ethylhexyl) phthalate (DEHP, mean = 226.23 ng/g dw) were the most abundant congeners. Notably, DEHP constituted the most predominant fraction (43.98 %) of the 13 PAEs detected in all shellfish from the PRD. Principal component analysis indicated that industrial and domestic emissions served as main sources for the PAE pollution in shellfish from the PRD. It was estimated that the daily intake of PAEs via shellfish consumption among adults and children ranged from 0.004 to 1.27 µg/kgbw/day, without obvious non-cancer risks (< 0.034), but the cancer risks raised some alarm (2.0 × 10-9-1.4 × 10-5). These findings highlight the necessity of focusing on marine environmental pollutants and emphasize the importance of ongoing monitoring of PAE contamination in seafood.

Systematic evaluation and review of Germany renewable energy research: A bibliometric study from 2008 to 2023.

Research purpose: This study aims to outline the fundamental status of the German academic community's research in the field of renewable energy and to foster collaboration between China and Germany in this area. Research methods: This study examines documents published by German scholars from 2008 to 2023, which are part of the "Web of Science (WOS) Core Collection" database and related to renewable energy issues, using the bibliometric visualization tool CiteSpace 6.2.R6. Research conclusions: The study examines the co-occurrence and burst of keywords, changes in publication volume, international collaboration networks, research institution collaboration networks, and researcher collaboration networks. It concluded that: (1) German academic research in the field of renewable energy can be divided into three phases: nascent (2008-2014), surge (2015-2021), and decline (2022-2023). (2) The Helmholtz Association and Reinhard Madlener, among other prominent institutions and academicians, are responsible for the close cooperation among personnel and institutions, the significant leading effect, and the emphasis on cutting-edge topics. Research in this field notably focuses on cutting-edge issues like life cycle assessment and developing countries. The study observes a transition in research concentration from macro to micro perspectives. In the context of a global collective response to climate change, the analysis of the German academic community's overall situation will enhance the collaboration between the two countries in the field of renewable energy research.

Electrical stress and acid orange 7 synergistically clear the blockage of electron flow in the methanogenesis of low-strength wastewater.

Energy recovery from low-strength wastewater through anaerobic methanogenesis is constrained by limited substrate availability. The development of efficient methanogenic communities is critical but challenging. Here we develop a strategy to acclimate methanogenic communities using conductive carrier (CC), electrical stress (ES), and Acid Orange 7 (AO7) in a modified biofilter. The synergistic integration of CC, ES, and AO7 precipitated a remarkable 72-fold surge in methane production rate compared to the baseline. This increase was attributed to an altered methanogenic community function, independent of the continuous presence of AO7 and ES. AO7 acted as an external electron acceptor, accelerating acetogenesis from fermentation intermediates, restructuring the bacterial community, and enriching electroactive bacteria (EAB). Meanwhile, CC and ES orchestrated the assembly of the archaeal community and promoted electrotrophic methanogens, enhancing acetotrophic methanogenesis electron flow via a mechanism distinct from direct electrochemical interactions. The collective application of CC, ES, and AO7 effectively mitigated electron flow impediments in low-strength wastewater methanogenesis, achieving an additional 34% electron recovery from the substrate. This study proposes a new method of amending anaerobic digestion systems with conductive materials to advance wastewater treatment, sustainability, and energy self-sufficiency.

A colorimetric/electrochemical microfluidic biosensor using target-triggered DNA hydrogels for organophosphorus detection.

Organophosphorus compounds are widely distributed and highly toxic to the environment and living organisms. The current detection of organophosphorus compounds is based on a single-mode method, which makes it challenging to achieve good portability, accuracy, and sensitivity simultaneously. This study designed a multifunctional microfluidic chip to develop a dual-mode biosensor employing a DNA hydrogel as a carrier and aptamers as recognition probes for the colorimetric/electrochemical detection of malathion, an organophosphorus compound. The biosensor balanced portability and stability by combining a microfluidic chip and target-triggered DNA hydrogel-sensing technologies. Moreover, the biosensor based on target-triggered DNA hydrogel modified microfluidic developed in this study exhibited a dual-mode response to malathion, providing both colorimetric and electrochemical signals. The colorimetric mode enables rapid visualization and qualitative detection and, when combined with a smartphone, allows on-site quantitative analysis with a detection limit of 56 nM. The electrochemical mode offers a broad linear range (0.01-3000 µM) and high sensitivity (a limit of detection of 5 nM). The two modes could validate each other and improve the accuracy of detection. The colorimetric/electrochemical dual-mode biosensor based on target-triggered DNA hydrogel modified microfluidic chip offers a portable, simple, accurate, and sensitive strategy for detecting harmful environmental and food substances.

Oxysophoridine inhibits oxidative stress and inflammation in hepatic fibrosis via regulating Nrf2 and NF-κB pathways.

BACKGROUND: Hepatic fibrosis (HF) runs through multiple stages of liver diseases and promotes these diseases progression. Oxysophoridine (OSR), derived from Sophora alopecuroides l., is a bioactive alkaloid that has been reported to antagonize alcoholic hepatic injury. However, whether OSR suppresses HF and the mechanisms involved in Nrf2 remain unknown. PURPOSE: Since the dysregulation of inflammation and oxidative stress is responsible for the excessive accumulation of extracellular matrix (ECM) and fibrosis in the liver. We hypothesized that OSR may attenuate HF by inhibiting inflammation and oxidative stress through activating Nrf2 signaling. METHODS: In this study, we employed LPS-stimulated HSC-T6 cells, RAW264.7 cells, and a CCl4-induced C57BL/6 mouse fibrotic model to evaluate its suppressing inflammation and oxidative stress, as well as fibrosis. RESULTS: The result showed that OSR significantly reduced α-SMA and TGF-ß1 at a low dose of 10 µM in vitro and at a dose of 50 mg/kg in vivo, which is comparable to Silymarin, the only Chinese herbal active ingredient that has been marketed for anti-liver fibrosis. Moreover, OSR effectively suppressed the expression of iNOS at a dose of 10 µM and COX-2 at a dose of 40 µM, respectively. Furthermore, OSR demonstrated inhibitory effects on the IL-1ß, IL-6, and TNF-α in vitro and almost extinguished cytokine storm in vivo. OSR exhibited antioxidative effects by reducing MDA and increasing GSH, thereby protecting the cell membrane against oxidative damage and reducing LDH release. Moreover, OSR effectively upregulated the protein levels of Nrf2, HO-1, and p62, but decreased p-NF-κB p65, p-IκBα, and Keap1. Alternatively, mechanisms involved in Nrf2 were verified by siNrf2 interference, siNrf2 interference revealed that the anti-fibrotic effect of OSR was attributed to its activation of Nrf2. CONCLUSION: The present study provided an effective candidate for HF involved in both activation of Nrf2 and blockage of NF-κB, which has not been reported in the published work. The present study provides new insights for the identification of novel drug development for HF.

Acute effect of ambient air pollution on stroke mortality in the China air pollution and health effects study.

BACKGROUND AND PURPOSE: There have been no multicity studies on the acute effects of air pollution on stroke mortality in China. This study was undertaken to examine the associations between daily stroke mortality and outdoor air pollution (particulate matter <10 µm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide) in 8 Chinese cities. METHODS: We used Poisson regression models with natural spline-smoothing functions to adjust for long-term and seasonal trends, as well as other time-varying covariates. We applied 2-stage Bayesian hierarchical statistical models to estimate city-specific and national average associations of air pollution with daily stroke mortality. RESULTS: Air pollution was associated with daily stroke mortality in 8 Chinese cities. In the combined analysis, an increase of 10 µg/m(3) of 2-day moving average concentrations of particulate matter <10 µm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide corresponded to 0.54% (95% posterior intervals, 0.28-0.81), 0.88% (95% posterior intervals, 0.54-1.22), and 1.47% (95% posterior intervals, 0.88-2.06) increase of stroke mortality, respectively. The concentration-response curves indicated linear nonthreshold associations between air pollution and risk of stroke mortality. CONCLUSIONS: To our knowledge, this is the first multicity study in China, or even in other developing countries, to report the acute effect of air pollution on stroke mortality. Our results contribute to very limited data on the effect of air pollution on stroke for high-exposure settings typical in developing countries.

Load-insensitive temperature sensor based on azobenzene-chloroform-solution-filled microstructured optical fiber.

A solid-core microstructured optical fiber is infiltrated with the Dispersed Yellow 7 and chloroform mixture solution, resulting in the appearance of several transmission dips with different temperature and axial load responses. The temperature- and load-dependent spectral characteristics of these dips have been investigated and the experimental results indicate that they are pretty temperature-sensitive, but insensitive to the variation of applied axial load. Such a compact fiber-optic device with electric perturbation immunity could be employed for load-insensitive temperature sensing with high sensitivity.

Fiber in-line Mach-Zehnder interferometer based on near-elliptical core photonic crystal fiber for temperature and strain sensing.

A fiber in-line Mach-Zehnder interferometer is fabricated by selectively filling liquid into one air hole of the innermost layer of a photonic crystal fiber (PCF). The refractive index of the liquid is so close to that of the background silica in the wavelength range of 1300-1600 nm that the two-mode PCF evolves into multimode PCF with an elliptically shaped core. Due to the different propagation constants, interference can occur between the fundamental mode and higher-order modes of the liquid-filled PCF. Such a device is applied in temperature and strain measurements with high sensitivities of 16.49 nm/°C and -14.595 nm/N, respectively.