64 research outputs found

    POLYETHERSULFONE COMPOSITE MEMBRANE BLENDED WITH CELLULOSE FIBRILS

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    Polyethersulfone (PES) is a common material used for ultrafiltration (UF) membranes, which has good chemical resistance, high mechanical properties, and wide temperature tolerances. The hydrophobic property of the PES membrane seriously limits its application. Cellulose fibrils are composed of micro-sized and nano-sized elements, which have high hydrophilicity, strength, and biodegradation. A composite membrane was prepared by the phase inversion induced by an immersion process. The characteristics of the composite membrane were investigated with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). The pure water flux of the composite membrane increased dramatically with the increase of cellulose firbils. Mean pore size and porosity were significantly increased. Both mechanical properties and hydrophilicity were enhanced due to the addition of the cellulose firbils

    Pulmonary alveolar type I cell population consists of two distinct subtypes that differ in cell fate.

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    Pulmonary alveolar type I (AT1) cells cover more than 95% of alveolar surface and are essential for the air-blood barrier function of lungs. AT1 cells have been shown to retain developmental plasticity during alveolar regeneration. However, the development and heterogeneity of AT1 cells remain largely unknown. Here, we conducted a single-cell RNA-seq analysis to characterize postnatal AT1 cell development and identified insulin-like growth factor-binding protein 2 (Igfbp2) as a genetic marker specifically expressed in postnatal AT1 cells. The portion of AT1 cells expressing Igfbp2 increases during alveologenesis and in post pneumonectomy (PNX) newly formed alveoli. We found that the adult AT1 cell population contains both Hopx+Igfbp2+ and Hopx+Igfbp2- AT1 cells, which have distinct cell fates during alveolar regeneration. Using an Igfbp2-CreER mouse model, we demonstrate that Hopx+Igfbp2+ AT1 cells represent terminally differentiated AT1 cells that are not able to transdifferentiate into AT2 cells during post-PNX alveolar regeneration. Our study provides tools and insights that will guide future investigations into the molecular and cellular mechanism or mechanisms underlying AT1 cell fate during lung development and regeneration

    Impact of dietary manganese on intestinal barrier and inflammatory response in broilers challenged with Salmonella Typhimurium

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    Growing concern for public health and food safety has prompted a special interest in developing nutritional strategies for removing waterborne and foodborne pathogens, including Salmonella. Strong links between manganese (Mn) and intestinal barrier or immune function hint that dietary Mn supplementation is likely to be a promising approach to limit the loads of pathogens in broilers. Here, we provide evidence that Salmonella Typhimurium (S. Typhimurium, 4 × 108 CFUs) challenge-induced intestinal injury along with systemic Mn redistribution in broilers. Further examining of the effect of dietary Mn treatments (a basal diet plus additional 0, 40, or 100 mg Mn/kg for corresponding to Mn-deficient, control, or Mn-surfeit diet, respectively) on intestinal barrier and inflammation status of broilers infected with S. Typhimurium revealed that birds fed the control and Mn-surfeit diets exhibited improved intestinal tight junctions and microbiota composition. Even without Salmonella infection, dietary Mn deficiency alone increased intestinal permeability by impairing intestinal tight junctions. In addition, when fed the control and Mn-surfeit diets, birds showed decreased Salmonella burdens in cecal content and spleen, with a concomitant increase in inflammatory cytokine levels in spleen. Furthermore, the dietary Mn-supplementation-mediated induction of cytokine production was probably associated with the nuclear factor kappa-B (NF-κB)/hydrogen peroxide (H2O2) pathway, as judged by the enhanced manganese superoxide dismutase activity and the increased H2O2 level in mitochondria, together with the increased mRNA level of NF-κB in spleen. Ingenuity-pathway analysis indicated that acute-phase response pathways, T helper type 1 pathway, and dendritic cell maturation were significantly activated by the dietary Mn supplementation. Our data suggest that dietary Mn supplementation could enhance intestinal barrier and splenic inflammatory response to fight against Salmonella infection in broilers

    The performance of mixture refrigerant R134a/R152a in a novel gas engine-driven heat pump system

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    In the present article, a novel gas engine-driven heat pump (GEHP) which could independently provide heating, cooling, and hot water for the buildings with its autonomous power supply system was presented, and the cooling performance characteristics of GEHP using mixture refrigerant R134a/R152a were investigated experimentally. The thermophysical properties and flammability of this proposed mixture refrigerant were analyzed and experimented to approve that it could be used safely in GEHP. The experimental results indicated that the cooling capacity, waste heat recovered from cylinder jacket and exhaust gas, gas engine energy consumption, and compressor power increased with the increase of the gas engine speeds and evaporator water inlet flow rate, but changed in a small range with the increase of the evaporator water inlet temperature except cooling capacity. The generator power remained about 4.90 kW in different operating conditions. Furthermore, the coefficient of performance (COP) and the primary energy ratio (PER) of GEHP also increased with the increase of the evaporator water inlet flow rate and temperature, but decreased with the increase of gas engine speeds. Finally, maximum COP and PER with mixture refrigerant R134a/R152a has been estimated with 8.88 and 1.69 in the aforementioned conditions.The National Natural Science Foundation of China (Grant No. 51076112 and 51276124) and the Science and Technology Project of Tiajin City (Grant No. 12ZCDGGX49400).http://www.tandfonline.com/loi/ljge20hb2016Mechanical and Aeronautical Engineerin

    Anti-thrombotic effect of combination of low molecular heparin and Xueshuantong after replantation of amputated finger

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    Purpose: To study the effects of low molecular heparin combined with Xueshuantong in preventing thrombosis after replantation of amputated finger.Methods: The treatment group (38 patients) was given 4500 IU of low molecular heparin sodium i.h. (hypodermic injection), q.d.(once daily), with 200 mL of 150 mg Xueshuantong injection and 5 % glucose injection, i.v.d. (intravenous drip), b.i.d. (twice daily). The control group received low molecular heparin sodium at 4500 IU i.h., q.d. alone. Treatment was for 3 days. Thereafter, D-dimer, fibrinogen, hemoglobin, platelets, prothrombin time (PT) and blood coagulation of patients in the 2 groups before and after treatment were compared. Differences in vasospasm, vascular thrombosis, finger necrosis, therapeutic effects and adverse reactions in patients in the 2 groups after treatment were recorded.Results: There were significant improvements in fibrinogen, platelet, PT levels, and blood coagulation time after treatment, with improvements better in the treatment group than in the control group (p < 0.05). Vasospasm cases (3) were lower in the treatment group than in the control group (8, p < 0.05), while vascular thrombosis and finger necrosis in both groups were comparable. Therapeutic effects and recovery were better in the treatment group than in the control group (p < 0.05).Conclusion: Combined injection of Xueshuantong and low molecular heparin exerts antithrombotic effects after replantation of amputated finger, improves coagulation function, and reduces incidence of vasospasm. It has better therapeutic effects than low molecular heparin, and it seems safe.Keywords: Xueshuantong, Low molecular heparin, Replantation, Amputated finger, Thrombosi

    Implementing a high-efficiency similarity analysis approach for firmware code.

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    The rapid expansion of the open-source community has shortened the software development cycle, but the spread of vulnerabilities has been accelerated, especially in the field of the Internet of Things. In recent years, the frequency of attacks against connected devices is increasing exponentially; thus, the vulnerabilities are more serious in nature. The state-of-the-art firmware security inspection technologies, such as methods based on machine learning and graph theory, find similar applications depending on the known vulnerabilities but cannot do anything without detailed information about the vulnerabilities. Moreover, model training, which is necessary for the machine learning technologies, requires a significant amount of time and data, resulting in low efficiency and poor extensibility. Aiming at the above shortcomings, a high-efficiency similarity analysis approach for firmware code is proposed in this study. First, the function control flow features and data flow features are extracted from the functions of the firmware and of the vulnerabilities, and the features are used to calculate the SimHash of the functions. The mass storage and fast query capabilities of the SimHash are implemented by the pigeonhole principle. Second, the similarity function pairs are analyzed in detail within and among the basic blocks. Within the basic blocks, the symbolic execution is used to generate the basic block semantic information, and the constraint solver is used to determine the semantic equivalence. Among the basic blocks, the local control flow graphs are analyzed to obtain their similarity. Then, we implemented a prototype and present the evaluation. The evaluation results demonstrate that the proposed approach can implement large-scale firmware function similarity analysis. It can also get the location of the real-world firmware patch without vulnerability function information. Finally, we compare our method with existing methods. The comparison results demonstrate that our method is more efficient and accurate than the Gemini and StagedMethod. More than 90% of the firmware functions can be indexed within 0.1 s, while the search time of 100,000 firmware functions is less than 2 s

    Test of Broken Suspender Specimen and Equivalent Static Calculation Method for Half-Through and Through Concrete-Filled Steel Tubular Arch Bridges

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    In response to the frequent collapse of main girders caused by the breakage of suspenders on half-through and through arch bridges, a test specimen has been designed and fabricated with a through concrete-filled steel tube (CFST) arch bridge as the engineering background. A new electromagnetic disconnect trigger is employed to realize the rapid suspender breakage in the test specimen. Dynamic response tests of the residual structure of the arch bridge after suspender failures employing the test specimen have been carried out. A finite element model accounting for the suspender breakage dynamic process has been constructed by implementing ANSYS/LS-DYNA, and the results of the test and finite element analysis are compared. In order to simplify the dynamic response calculation process of the residual structure after hanger failures, the dynamic coefficient is introduced, and an equivalent static calculation method (ESCM) considering the dynamic effect of the suspender fracture is presented. Eleven kinds of CFST standard arch bridges with different spans are constructed, the static and dynamic effects of the standard arch bridge with various dynamic coefficients are compared, and then their corresponding dynamic coefficients for various suspender fractures are determined. The obtained results reveal that the proposed electromagnetic suspender breakage trigger can realize the hanger fracturing within 0.1 s, which accurately simulates the fracture process of an actual bridge suspender, and the influence on the value of the dynamic coefficient can be ignored when the duration for suspender fracture is less than or equal to 0.15 s. The influence of suspender fracture on the displacement and stress of the longitudinal beam is more notable than those of the arch rib. In particular, the long suspender breakage has the highest influence on the displacement and stress of the longitudinal beam and arch rib. The fracture of the second short suspender has a remarkable impact on the suspender force of the adjacent hanger. When the ESCM is utilized to assess the mechanical behavior of the half-through and through CFST arch bridge, the dynamic coefficients of the longitudinal beam (suspender) were evaluated to be, conservatively, 1.8 (1.8) and 1.8 (1.7), respectively

    Test of Broken Suspender Specimen and Equivalent Static Calculation Method for Half-Through and Through Concrete-Filled Steel Tubular Arch Bridges

    No full text
    In response to the frequent collapse of main girders caused by the breakage of suspenders on half-through and through arch bridges, a test specimen has been designed and fabricated with a through concrete-filled steel tube (CFST) arch bridge as the engineering background. A new electromagnetic disconnect trigger is employed to realize the rapid suspender breakage in the test specimen. Dynamic response tests of the residual structure of the arch bridge after suspender failures employing the test specimen have been carried out. A finite element model accounting for the suspender breakage dynamic process has been constructed by implementing ANSYS/LS-DYNA, and the results of the test and finite element analysis are compared. In order to simplify the dynamic response calculation process of the residual structure after hanger failures, the dynamic coefficient is introduced, and an equivalent static calculation method (ESCM) considering the dynamic effect of the suspender fracture is presented. Eleven kinds of CFST standard arch bridges with different spans are constructed, the static and dynamic effects of the standard arch bridge with various dynamic coefficients are compared, and then their corresponding dynamic coefficients for various suspender fractures are determined. The obtained results reveal that the proposed electromagnetic suspender breakage trigger can realize the hanger fracturing within 0.1 s, which accurately simulates the fracture process of an actual bridge suspender, and the influence on the value of the dynamic coefficient can be ignored when the duration for suspender fracture is less than or equal to 0.15 s. The influence of suspender fracture on the displacement and stress of the longitudinal beam is more notable than those of the arch rib. In particular, the long suspender breakage has the highest influence on the displacement and stress of the longitudinal beam and arch rib. The fracture of the second short suspender has a remarkable impact on the suspender force of the adjacent hanger. When the ESCM is utilized to assess the mechanical behavior of the half-through and through CFST arch bridge, the dynamic coefficients of the longitudinal beam (suspender) were evaluated to be, conservatively, 1.8 (1.8) and 1.8 (1.7), respectively
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