High adsorption selectivity of activated carbon and carbon molecular sieve boosting CO_(2)/N_(2) and CH_(4)/N_(2) separation

Flue gas and coal bed methane are two important sources of greenhouse gases.Pressure swing adsorption process has a wide range of application in the field of gas separation,and the selection of adsorbent is crucial.In this regard,in order to assess the better adsorbent for separating CO_(2) from flue gas and CH_(4) from coal bed methane,adsorption isotherms of CO_(2),CH_(4) and N_(2) on activated carbon and carbon molecular sieve are measured at 303.15,318.15 and 333.15 K,and up to 250 kPa.The experimental data fit better with Langmuir 2 compared to Langmuir 3 and Langmuir-Freundlich models,and Clausius-Clapeyron equation was used to calculate the isosteric heat.Both the order of the adsorbed amount and the adsorption heat on the two adsorbents are CO_(2)>CH_(4)>N_(2).The adsorption kinetics are calculated by the pseudo-first kinetic model,and the order of adsorption rates on activated carbon is N_(2)-CH_(4)>CO_(2),while on carbon molecular sieve,it is CO_(2)-N_(2)>CH_(4).It is shown that relative molecular mass and adsorption heat are the primary effect on kinetics for activated carbon,while kinetic diameter is the main resistance factor for carbon molecular sieve.Moreover,the adsorption selectivity of CH_(4)/N_(2) and CO_(2)/N_(2) were estimated with the ideal adsorption solution theory,and carbon molecular sieve performed best at 318.15 K for both CO_(2) and CH_(4) separation.The study suggested that activated carbon is a better choice for separating flue gas and carbon molecular sieve can be a strong candidate for separating coal bed methane.

Intestinal dysbiosis exacerbates the pathogenesis of psoriasis-like phenotype through changes in fatty acid metabolism

The intestinal microbiota has been associated with host immunity as well as psoriasis;however,the mechanism of intestinal microbiota regulating psoriasis needs to be demonstrated systematically.Here,we sought to examine its role and mechanism of action in the pathogenesis of psoriasis.We found that the severity of psoriasis-like skin phenotype was accompanied by changes in the composition of the intestinal microbiota.We performed co-housing and fecal microbial transplantation(FMT)experiments using the K14-VEGF transgenic mouse model of psoriasis and demonstrated that the transfer of intestinal microbiota from mice with severe psoriasis-like skin phenotype exacerbated psoriasiform skin inflammation in mice with mild symptoms,including increasing the infiltration and differentiation of Th17,and increased the abundance of Prevotella,while decreasing that of Parabacteroides distasonis,in the colon.These alterations affected fatty acid metabolism,increasing the abundance of oleic and stearic acids.Meanwhile,gentamicin treatment significantly reduced the abundance of Prevotella and alleviated the psoriasis-like symptoms in both K14-VEGF mice and imiquimod(IMQ)-induced psoriasis-like mice.Indeed,administration of oleic and stearic acids exacerbated psoriasis-like symptoms and increased Th17 and monocyte-derived dendritic cell infiltration in the skin lesion areas in vivo,as well as increased the secretion of IL-23 by stimulating DCs in vitro.At last,we found that,treatment of PDE-4 inhibitor alleviated psoriasis-like phenotype of K14-VEGF mice accompanied by the recovery of intestinal microbiota,including the decrease of Prevotella and increase of Parabacteroides distasonis.Overall,our findings reveal that the intestinal microbiota modulates host metabolism and psoriasis-like skin inflammation in mice,suggesting a new target for the clinical diagnosis and treatment of psoriasis.

Known-key distinguishers on type-1 Feistel scheme and near-collision attacks on its hashing modes

We present some known-key distinguishers for a type-1 Feistel scheme with a permutation as the round function. To be more specific, the 29-round known-key truncated differential distinguishers are given for the 256-bit type-1 Feistel scheme with an SP （substitution-permutation） round function by using the rebound attack, where the S-boxes have perfect differential and linear properties and the linear diffusion layer has a maximum branch number. For two 128-bit versions, the distinguishers can be applied on 25- round structures. Based on these distinguishers, we construct near-collision attacks on these schemes with MMO （Matyas- Meyer-Oseas） and MP （Miyaguchi-Preneel） hashing modes, and propose the 26-round and 22-round near-collision attacks for two 256-bit schemes and two 128-bit schemes, respectively. We apply the near-collision attack on MAME and obtain a 26-round near-collision attack. Using the algebraic degree and some integral properties, we prove the correctness of the 31-round known-key integral distinguisher proposed by Sasaki et al. We show that if the round function is a permutation, the integral distinguisher is suitable for a type-1 Feistel scheme of any size.