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Persistent pollution often occurs in North China in winter. The study of the sub-seasonal evolution characteristics of fine particles (PM2.5) can provide a theoretical basis for the prediction and prevention of persistent pollution. Based on the high-resolution gridded data of PM2.5 and NCEP/NCAR reanalysis, the sub-seasonal variation in PM2.5 in North China in winter and its dominant circulation patterns from 1960/61 to 2019/20 were analyzed. The results show that, in winter, PM2.5 in North China shows a dominant period of 10–20 days, and persistent heavy pollution occurs at the active phase of oscillation. Based on the PM2.5 quasi-biweekly oscillation (QBWO) events, the 850 hPa wave train can be classified into four categories. It was found that, during the active phase of PM2.5 QBWO, the wind speed is weak and humidity is high in the low-troposphere for all of the four event types, while the quasi-biweekly 850 hPa wave train and the track of geopotential height anomaly are significantly different. Based on the characteristics of circulation evolution, these four types of events can be named as eastward, split southward, southeastward, and merged event. The energy conversion between the basic flow and the quasi-biweekly disturbance, and the mean flow difference are responsible for the circulation diversity for different PM2.5 QBWO events. The above research results can provide a theoretical basis for pollutant prediction. [ABSTRACT FROM AUTHOR]

An international assessment of wetlands is important for quantifying the current state of development of international wetland structure and function. At present, the management department and public lack a comprehensive understanding of the ecological status of internationally important wetlands in China. Here, using annual ecological monitoring data and hierarchical analysis, an evaluation index system was constructed with water environment, biological environment, biodiversity, and disturbance pressure as influencing factors, and an evaluation of the ecological status of 63 wetlands of international importance (WOII) in China was carried out, it is helpful to formulate technical plans for the ecological management of wetlands of international importance (WOII). The results showed that the average ecological status score of these wetlands was 0.714 ± 0.075, and there were differences in this score between different regions. The ecological status of wetlands in northeastern and northern coastal areas were mostly evaluated as 'excellent' and 'good', while some wetlands in other areas of China were evaluated as 'poor'. The type and protection level of wetlands have an important impact on their ecological status. The ecological status of wetlands according to type were ranked swamp wetlands > coastal wetlands > river wetlands > lake wetlands, while those with national level protection were ranked higher than those with provincial level protection. The ecological status of WOII in China is generally good, but is adversely affected by human activities, alien species invasion, and other factors. Hence, there needs to be a focus on improving the protection and management mechanisms for WOII, promoting improvements in the ecological status of these wetlands, and transforming ecological product value. [ABSTRACT FROM AUTHOR]

In this study, the volatile organic compounds (VOCs) during the photochemical season in Hancheng City in 2020 were measured continuously and analyzed using models' simulation. The characteristics, emission sources, regional hotspots, effects on ozone (O3) production, and health risks of VOCs were investigated. The results of the study showed that the high ozone period in Hancheng was chiefly restricted by VOCs. Based on the abatement scenario modeling, it was clear that reducing VOCs and NOx in a 1:3 ratio is a feasible strategy to achieve the O3 emission standard. Source analysis and spatial heterogeneity characteristics of VOCs revealed that coking production is the largest contributor to VOCs, but solvent sources dominated ozone formation. Hence, VOC control focused mainly on localized areas along the Yellow River Basin and the chemical spraying industry. Besides, more than half of the average total formation rate of O3 formation was generated by the reaction of RO2 radicals with NO. The emission of key species, such as toluene, o-xylene, styrene, 1-butene, 1,2,3-trimethylbenzene, and m/p-xylene, further aggravated photochemical O3 pollution. Therefore, an active VOC species control policy is a significant means to lessen O3 contamination. [ABSTRACT FROM AUTHOR]

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Innate immune system such as Toll-like receptor 4 (TLR4) represents the first line of defense against infection. In addition to its pivotal role in host immunity, recent studies have suggested that TLR4 may play a broader role in mediating tissue inflammation and cell survival in response to noninfectious injury. We and other investigators have reported that cardiac TLR4 signaling is dynamically modulated in ischemic myocardium and that activation of TLR4 confers a survival benefit in the heart and in isolated cardiomyocytes. However, the signaling pathways leading to these effects are not completely understood. Here, we investigate the role of MyD88, an adaptor protein of TLR4 signaling, and inducible nitric oxide synthase (NOS2) in mediating TLR4-induced cardiomyocyte survival in an in vitro model of apoptosis. Serum deprivation induced a significant increase in the number of apoptotic cardiomyocytes as demonstrated by transferase-mediated dUTP nick-end labeling (TUNEL) assay, nuclear morphology, DNA laddering, and DNA-histone ELISA. Lipopolysaccharide (LPS), a TLR4 agonist, activated TLR4 signaling and led to significant reduction in apoptotic cardiomyocytes and improved cellular function of surviving cardiomyocytes with enhanced [Ca.sup.2+] transients and cell shortening. We found that both TLR4 and MyD88 are required for the LPS-induced beneficial effects as demonstrated by improved survival and function in wild-type but not in [TLR4.sup.-/-] or [MyD88.sup.-/-] cardiomyocytes. Moreover, genetic deletion or pharmacological inhibition of NOS2 abolished survival and functional rescue of cardiomyocytes treated with LPS. Taken together, these data suggest that TLR4 protects cardiomyocytes from stress-induced injury through MyD88- and NOS2-dependent mechanisms. signal transduction; cardiac; apoptosis; inducible nitric oxide synthase

Background: Whether patients with non-small cell lung cancer (NSCLC) with unexpected pleural dissemination (UPD) could get survival benefit from tumor resection remained controversial.Methods: Totally, 169 patients with NSCLC with UPD were included between 2012 and 2016. Patients were divided into the tumor resection and open-close group. Progression-free survival (PFS) and overall survival (OS) were compared with a log-rank test. The multivariable Cox analysis was applied to identify prognostic factors.Results: Sixty-five patients received open-close surgery and 104 patients underwent main tumor and visible pleural nodule resection. Tumor resection significantly prolonged OS (hazard ratio [HR]: 0.408, P < 0.001), local PFS (HR: 0.283, P < 0.001), regional PFS (HR: 0.506, P = 0.005), and distant metastasis (HR: 0.595, P = 0.032). Multivariable Cox analysis confirmed that surgical method was an independent prognostic factor for OS, local PFS and regional PFS, except distant metastasis. Subgroup analyses indicated that tumor resection could not improve OS in the patients who received targeted therapy (HR: 0.649, P = 0.382), however, tumor resection was beneficial for the patients who received adjuvant chemotherapy alone (HR: 0.322, P < 0.001). In the tumor resection group, lobectomy (HR: 0.960, P = 0.917) and systematic lymphadenectomy (HR: 1.512, P = 0.259) did not show survival benefit for OS.Conclusions: Main tumor and visible pleural nodule resection could improve prognosis in patients with UPD who could not receive adjuvant targeted therapy. Sublobar resection without systematic lymphadenectomy may be the optimal procedure. [ABSTRACT FROM AUTHOR]

Growing evidence supports that LKB1‐deficient KRAS‐driven lung tumors represent a unique therapeutic challenge, displaying strong cancer plasticity that promotes lineage conversion and drug resistance. Here we find that murine lung tumors from the KrasLSL‐G12D/+; Lkb1flox/flox (KL) model show strong plasticity, which associates with up‐regulation of stem cell pluripotency genes such as Nanog. Deletion of Nanog in KL model initiates a gastric differentiation program and promotes mucinous lung tumor growth. We find that NANOG is not expressed at a meaningful level in human lung adenocarcinoma (ADC), as well as in human lung invasive mucinous adenocarcinoma (IMA). Gastric differentiation involves activation of Notch signaling, and perturbation of Notch pathway by the γ‐secretase inhibitor LY‐411575 remarkably impairs mucinous tumor formation. In contrast to non‐mucinous tumors, mucinous tumors are resistant to phenformin treatment. Such therapeutic resistance could be overcome through combined treatments with LY‐411575 and phenformin. Overall, we uncover a previously unappreciated plasticity of LKB1‐deficient tumors and identify the Nanog‐Notch axis in regulating gastric differentiation, which holds important therapeutic implication for the treatment of mucinous lung cancer. Synopsis: This study reveals the plasticity of LKB1‐deficient tumors, and identifies the Nanog‐Notch axis in regulating gastric differentiation. Combinational treatment of γ‐secretase inhibitor LY‐411575 and phenformin effectively blocked invasive mucinous adenocarcinoma IMA formation. Invasive mucinous adenocarcinoma (IMA) was promoted by Nanog deficiency in the KrasLSL‐G12D/+; Lkb1flox/flox KL mouse model.Concurrent loss of NANOG and LKB1 was frequent in human lung IMA.Mucinous differentiation was inhibited by perturbation of the Notch pathway.IMA was insensitive to phenformin treatment.IMA formation was blocked by a combinational treatment of LY‐411575 and phenformin. [ABSTRACT FROM AUTHOR]

Enrofloxacin (ENR) is a synthetic fluoroquinolone antibiotic used for the treatment of infection in animals. The use of ENR has been strictly regulated because of its harmful effect on consumers of animal products. In this study the generation of polyclonal antibody (pAb) against ENR, the preparation of an immunoaffinity chromatography column and its potential application to the selective extraction of ENR residues from food samples were described. The produced pAb exhibited good sensitivity to ENR with an IC50value of 5.4 ng/mL. The cross-reactivity values of the antibody with ENR structurally related compounds were lower than 0.5%. An immunoaffinity column was constructed by coupling antibody covalently with chitosan microspheres. 0.8% NaOH/0.01 mol/L phosphate-buffered saline (PBS) (pH 7.4) and 85% methanol were selected as loading and eluting solution by careful optimization. Further characterization indicated that the binding capacity of the column for ENR was approximately 3780 ng/mL gel. The immunoaffinity columns were then challenged with ENR-fortified pork, and the recoveries of ENR were found to be in the range of 79.8–94.9%, demonstrating the feasibility of the prepared immunoaffinity column for sample clean-up in ENR residue determination. [ABSTRACT FROM AUTHOR]

Ultrafine electrospun polymer fibers, with their large specific surface areas, have not found wide applications partly because the fiber surfaces usually carry an insufficient quantity of active groups. The electrospinning and surface-grafting copolymerization of polystyrene fibrous membranes were carried out via the embedded radical initiator approach. The results from X-ray photoelectron spectroscopy show that the initiator added to the polystyrene dope was deliberately expelled onto the fiber surfaces. The microstructure and hydrophilicity of the grafted membranes were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, and water contact angle and water uptake capacity measurements. An increase in the initiator dosages led to decreases in the grafting rate, water uptake, and hydrophilicity of the grafted membranes; the opposite was true for increases in the neutralization of acrylic acid (AA). However, the grafting, water uptake, and hydrophilicity of the grafted membranes presented nonlinear relationships with the concentration of AA. The initiator emigration technique will provide a facile and feasible platform for the surface-grafting modification of electrospun membranes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

The article presents a study that investigated the effects of solution properties in terms of the residual acetyl group and high valence metal ion impurity of polyvinyl alcohol (PVA) fiber on electrospinning. The study showed the existence of physicochemical interaction besides concentration and molar mass factors in the solution viscosity. NMR spectra and DSC thermographs were used to determine the ability of devoid acetyl group of PVA to promote the physical gelation.

Abstract: To investigate the cellular mechanisms for altered cardiac function in senescence, we measured Ca2+ transients and Ca2+ sparks in ventricular cardiomyocytes from 6- to 24-month-old Fisher 344 (F344) rat hearts. The single channel properties of ryanodine receptors from adult and senescent hearts were also studied. In senescent myocytes, we observed a decreased peak [Ca2+]i amplitude and an increased time constant for decay (τ), both of which correlated with a reduced Ca2+ content of the sarcoplasmic reticulum (SR). Our studies also revealed that senescent cardiomyocytes had an increased frequency of Ca2+ sparks and a slight but statistically significant decrease in average amplitude, full-width-at-half-maximum (FWHM) and full-duration-at-half-maximum (FDHM). Single channel recordings of ryanodine receptors (RyR2) demonstrated that in aging hearts, the open probability (P o) of RyR2 was increased but the mean open time was shorter, providing a molecular correlate for the increased frequency of Ca2+ sparks and decreased size of sparks, respectively. Thus, modifications of normal RyR2 gating properties may play a role in the altered Ca2+ homeostasis observed in senescent myocytes. [Copyright &y& Elsevier]

Abstract: Objective: Diastolic dysfunction is a characteristic finding of the aged mammalian heart. Parvalbumin acts as a Ca2+ sink and enhances relaxation in skeletal muscle, and overexpression of parvalbumin in myocardium increased cardiac relaxation in vitro as well as in vivo. Therefore, the objective of this study is to test the hypothesis that in vivo gene transfer of parvalbumin will improve diastolic dysfunction in aged rat heart. Methods: We used adenovirus to transfer parvalbumin into two different rat models of aging: the Fischer 344 (F344) and the Fischer 344×Brown Norway F1 hybrid (F344×BN). Cardiac function was measured and compared after gene transfer. Results: In vivo overexpression of parvalbumin in both rat aging models had no effect on systolic parameters but reduced left ventricular diastolic pressure and the time course of pressure decline. Overexpression of parvalbumin also improved the force frequency relationship in senescent rats. Conclusion: In vivo overexpression of parvalbumin improves diastolic dysfunction in two rat models of senescence, and this effect is independent of the rat strain investigated. The results show promise that gene therapy of parvalbumin may address the impaired Ca2+ homeostasis and diastolic dysfunction without an increase in energy expenditure. [Copyright &y& Elsevier]