42 research outputs found

    Inhalation of electronic cigarettes slightly affects lung function and inflammation in mice

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    Electronic cigarettes have become increasingly popular, but the results of previous studies on electronic cigarette exposure in animals have been equivocal. This study aimed to evaluate the effects of electronic cigarette smoke (ECS) and cigarette smoke (CS) on lung function and pulmonary inflammation in mice to investigate whether electronic cigarettes are safer when compared to cigarettes. 32 specific pathogen-free BALB/c male mice were randomly grouped and exposed to fresh air (control), mint-flavored ECS (ECS1, 6 mg/kg), cheese-flavored ECS (ECS2, 6 mg/kg), and CS (6 mg/kg). After 3 weeks exposure to ECS or CS, we measured lung function (PIF and Penh) and blood oxygen saturation. The levels of TNF-α and IL-6 in the bronchoalveolar lavage fluid (BALF) and serum were measured using ELISA. HE staining was performed to observe the pathological changes in the lung tissues. The levels of IL-6 in BALF and serum, and TNF-α in BALF, were elevated similarly in the ECS and CS groups compared to the control group. Significant elevation was observed in serum TNF-α levels in the CS group. The total count of cells in BALF were increased after ECS1 exposure and CS exposure. PIF and oxygen saturation decreased, and Penh increased markedly in the CS group but not in the ECS groups. Compared with the ECS groups, mice in the CS group had widened lung tissue septa and increased inflammatory cell infiltration. However, we did not detect significant differences between mint-flavored and cheese-flavored e-cigarettes in our study. Overall, our findings suggested that both ECS and CS impair lung function and histopathology while promoting inflammation. In contrast, ECS has a less negative impact than CS

    Fabrication and characterization of Ge–Sb–Se–I glasses and fibers

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    International audienceChalcogenide glasses of the Ge20Sb5Se75−x I x (x = 0, 5, 10, 15, 20 at.%) system were prepared. This study was performed to examine some Ge–Sb–Se–I glass physical and optical properties, the structural evolution of the glass network, and the optical properties of the infrared glass fibers based on our previous studies. The variation process of the glass physical properties, such as transition temperature, glass density, and refractive index, was investigated from the glass of Ge20Sb5Se75 to the Ge20Sb5Se75−x I x glass series. The structural evolutions of these glasses were examined by Raman spectroscopy. The Ge20Sb5Se55I20 composition was selected for the preparation of the IR fiber. The Ge20Sb5Se55I20 glass was purified through distillation, and the intensity of the impurity absorption peaks caused by Ge–O, H2O, and Se–H was reduced or eliminated in the purified glasses. Then, Ge20Sb5Se55I20 chalcogenide glass fiber for mid-infrared transmission was fabricated using high-purity materials. The transmission loss of the Ge20Sb5Se55I20 fiber was greatly reduced compared with that of the Ge20Sb5Se75 glass fiber. The lowest losses obtained were 3.5 dB/m at 3.3 μm for Ge20Sb5Se75I20 fiber, which was remarkably improved compared with 48 dB/m of the unpurified Ge20Sb5Se75 fiber

    Information Retrieval and Filtering Using the Riemannian SVD

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    I am very grateful to my wife, Alice, and my son, George, for their love, patience and understanding, and without their full support, the completion of this work would not have been possible. Finally, many thanks go to my parents for their unfailing love and for believing I would succeed even at my most doubtful moments

    Demand Response Transit Scheduling Research Based on Urban and Rural Transportation Station Optimization

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    To reduce the operating cost and running time of demand responsive transit between urban and rural areas, a DBSCAN K-means (DK-means) clustering algorithm, which is based on the density-based spatial clustering of applications with noise (DBSCAN) and K-means clustering algorithm, was proposed to cluster pre-processing and station optimization for passenger reservation demand and to design a new variable-route demand responsive transit service system that can promote urban–rural integration. Firstly, after preprocessing the reservation demand through DBSCAN clustering algorithm, K-means clustering algorithm was used to divide fixed sites and alternative sites. Then, a bus scheduling model was established, and a genetic simulated annealing algorithm was proposed to solve the model. Finally, the feasibility of the model was validated in the northern area of Yongcheng City, Henan Province, China. The results show that the optimized bus scheduling reduced the operating cost and running time by 9.5% and 9.0%, respectively, compared with those of the regional flexible bus, and 4.5% and 5.1%, respectively, compared with those of the variable-route demand response transit after K-means clustering for passenger preprocessing

    Heat Integration for Phenols and Ammonia Recovery Process of Coal Gasification Wastewater Considering Optimization of Process Parameters

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    A heat integration optimization method that considers the changes in process parameters is proposed to find the global optimal process scheme for a coal chemical company’s phenols and ammonia recovery process. The phenols and ammonia recovery process is simulated by Aspen Plus, and a programming method for heat exchanger networks synthesis that can simultaneously optimize process parameters and heat integration is constructed by Matlab. Taking the total annual cost as the objective function, the following process parameters are optimized: the hot feed temperature and cold/hot feed ratio of sour water stripper, the temperature of three-step partial condensation system, the feed temperature and column pressure of both solvent distillation column and solvent stripper. The result shows that, compared with the heat integration process under original process parameters, the new heat integration process saves 14.3% energy consumption and reduces the total annual cost by about 15.1%. The new heat integration process provides guidance for the optimization of the phenols and ammonia recovery process. The proposed heat integration optimization method based on changing process parameters is an effective and practical tool that offers good application prospects

    Experimental investigation on the surface humidity of fabric during the process of dynamic moisture liberation

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    Purpose: In this study, a novel dynamic testing method was established to measure the moisture variation of fabric surface during the process of moisture liberation in simulated windy condition. The paper aims to discuss these issues Design/methodology/approach: In this method, the samples were rotating during the test process so as to simulate the external windy environment. Effects of simulated wind speed, moisture regains and fabric materials on the surface moisture of fabric were investigated. Findings: Experimental results showed that the surface moisture presented a trapezoidal moisture liberation curve, it increased at first, then kept stable for a while, and decreased finally with the increase of time. It took longer time for the fabric to complete the liberation process when the moisture regain of the fabric increased or the simulated wind speed decreased. The fiber materials of the fabric affected the time for the moisture liberation process under a specific windy condition. Practical implications: This study will benefit the designing and development of clothing such as sportswear. Originality/value: A dynamic testing method was proposed to characterize the surface humidity of textiles under simulated windy conditions

    When does a freemium business model lead to high performance? — A qualitative comparative analysis based on fuzzy Sets

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    Existing research has neglected to explain why freemium business models lead to differentiated performance or what accounts for the difference in their revenue models. This study investigates how the configuration effect of freemium business models promotes performance and explores the different ways through which freemium business models, their dynamic capabilities, and environmental uncertainty interact to achieve high performance. The fuzzy set qualitative comparative analysis (fsQCA) approach was used to test the conceptual model with data from 45 freemium business model apps. From empirical evidence on the relationship between freemium business models, dynamic capabilities, and environmental uncertainty, the study finds that (1) bundled and fragmented freemium business models are fundamental performance drivers. However, they work only in combination with dynamic capabilities and environmental uncertainty. Moreover, the bundled and fragmented freemium business models have complementary rather than substitution relationships. (2) For companies with bundled and fragmented freemium business models, high sensing and seizing capabilities are critical to achieving high performance. A high bundled freemium business model, high sensing capability, and a lack of fragmented freemium business models and seizing capability can lead to high performance, regardless of reconfiguration capabilities and environmental uncertainty. (3) Under high environmental uncertainty, offering fragmented freemium business models with or without a bundled freemium business model will lead to high performance if they have high sensing, seizing, and reconfiguring capabilities. This study can provide systematic decision support for achieving high performance through freemium business models and the configuration of dynamic capabilities under environmental uncertainty

    Image_2_Case report: Different clinical manifestations of the rare Loeffler endocarditis.TIF

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    BackgroundLoeffler endocarditis is a rare and fatal disease, which is prone to be misdiagnosed, owing to its various clinical manifestations. Consequently, an early identification of Loeffler endocarditis and its effective treatment are crucial steps to be undertaken for good prognosis.Case presentationThis report describes two cases of Loeffler endocarditis with different etiologies and clinical manifestations. Case 1 was caused by idiopathic eosinophilia and presented with a thrombus involving the tricuspid valve and right ventricular inflow tract (RVIT). The patient suffered from recurrent syncope following activity. After the patient underwent tricuspid valve replacement and thrombectomy, he took oral prednisone and warfarin for 2 years, consequent to which he discontinued both drugs. However, the disease recurred 6 months later, this time manifesting as edema of both legs. Echocardiography showed that a thrombus had reappeared in the RVIT. Thus, oral prednisone and warfarin therapy was readministered. Three months later, the thrombus had dissolved. Low-dose prednisone maintenance therapy was provided long term. Case 2 involved a patient who presented with recurrent fever, tightness in the chest, and asthma, and whose condition could not be confirmed, despite multiple local hospitalizations. In our hospital, echocardiography revealed biventricular apical thrombi. After comprehensive examinations, the final diagnosis was eosinophilic granulomatosis polyangiitis (EGPA) involving multiple organs, including the heart (Loeffler endocarditis), lungs, and kidneys. After administration of corticosteroid, anticoagulant, and immunosuppressive agents along with drugs to improve cardiac function, the patient's symptoms improved significantly.ConclusionIn Loeffler endocarditis due to idiopathic eosinophilia, long-term corticosteroid use may be required. Diverse and non-specific symptoms cause Loeffler endocarditis to be easily misdiagnosed. So, when a patient shows a persistent elevation of the eosinophil count with non-specific myocardial damage, the possibility of this disease, should always be considered. Furthermore, even when an invasive clinical procedure such as endomyocardial biopsy (EMB) is not available or acceptable, corticosteroids should be administered promptly to bring the eosinophil count back to the normal range, thereby halting the progression of disease and reducing patient mortality.</p

    Image_1_Case report: Different clinical manifestations of the rare Loeffler endocarditis.TIF

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    BackgroundLoeffler endocarditis is a rare and fatal disease, which is prone to be misdiagnosed, owing to its various clinical manifestations. Consequently, an early identification of Loeffler endocarditis and its effective treatment are crucial steps to be undertaken for good prognosis.Case presentationThis report describes two cases of Loeffler endocarditis with different etiologies and clinical manifestations. Case 1 was caused by idiopathic eosinophilia and presented with a thrombus involving the tricuspid valve and right ventricular inflow tract (RVIT). The patient suffered from recurrent syncope following activity. After the patient underwent tricuspid valve replacement and thrombectomy, he took oral prednisone and warfarin for 2 years, consequent to which he discontinued both drugs. However, the disease recurred 6 months later, this time manifesting as edema of both legs. Echocardiography showed that a thrombus had reappeared in the RVIT. Thus, oral prednisone and warfarin therapy was readministered. Three months later, the thrombus had dissolved. Low-dose prednisone maintenance therapy was provided long term. Case 2 involved a patient who presented with recurrent fever, tightness in the chest, and asthma, and whose condition could not be confirmed, despite multiple local hospitalizations. In our hospital, echocardiography revealed biventricular apical thrombi. After comprehensive examinations, the final diagnosis was eosinophilic granulomatosis polyangiitis (EGPA) involving multiple organs, including the heart (Loeffler endocarditis), lungs, and kidneys. After administration of corticosteroid, anticoagulant, and immunosuppressive agents along with drugs to improve cardiac function, the patient's symptoms improved significantly.ConclusionIn Loeffler endocarditis due to idiopathic eosinophilia, long-term corticosteroid use may be required. Diverse and non-specific symptoms cause Loeffler endocarditis to be easily misdiagnosed. So, when a patient shows a persistent elevation of the eosinophil count with non-specific myocardial damage, the possibility of this disease, should always be considered. Furthermore, even when an invasive clinical procedure such as endomyocardial biopsy (EMB) is not available or acceptable, corticosteroids should be administered promptly to bring the eosinophil count back to the normal range, thereby halting the progression of disease and reducing patient mortality.</p
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