Comments on the Interpretation of the Mechanism of Formation of Minor Products Accompanying the Catalytic Cracking of Cumene

The article “The Catalytic Cracking of Cumene” by Corma and Wojciechowski [11 discusses, among other things, mechanisms of formation of minor products accompanying dealkylation of isopro-pylbenzene. The mechanistic schemes advanced by the authors by artfully exhibited drawings seem to violate accepted principles of cationic reactions and ignore known facts of catalytic hydrocarbon conversions.     

Identification of naturally isolated Southern Louisiana's algal strains and the effect of higher CO2 content on fatty acid profiles for biodiesel production

BACKGROUND: Microalgae, with both high biomass productivity and oil content, are regarded as attractive candidates for the production of alternative biodiesel as well as for CO₂ biofixation. In the present study, four microalgal strains native to southeastern Louisiana's waters were isolated and identified to evaluate their potential for the production of biodiesel. Selected strains were identified through genomic DNA in sequencing of either 16S rRNA or 18S rRNA genes followed by lipid and fatty acid content characterization and quantification. RESULTS: High correlation was found with known nucleotide sequence identities at 98% with Sellaphora pupula, and 99% with Synechococcus sp., Chlorella sorokiniana, Scenedesmus abundans, and Chlorella vulgaris (control). The fatty acid profiles of these organisms changed when using 5% CO₂ aeration. Total fatty acids (TFA) decreased from 20.63 to 17.62, 54.83 to 24.4, and 29.82 to 23.99 g kg^?1 in Synechococcus sp., Sellaphora pupula and Chlorella sorokiniana, respectively. TFA increased from 14.14 to 31.49 and 15.14 to 47.52 g kg^?1 dry biomass in Scenedesmus abundans and Chlorella vulgaris (control), respectively. CONCLUSION: Chlorella sorokiniana, with a lower C18:3 and the highest biomass yield at 5% CO₂ aeration, was found to be the best candidate for biodiesel production. © 2012 Society of Chemical Industry     

服装在线社群特征对品牌忠诚度的影响研究

通过对服装在线社群特征的分析,引入社群认同为中介变量,构建服装在线社群特征、社群认同和品牌忠诚度之间的影响模型并提出假设.通过问卷调研,采用因子分析和回归分析探索服装在线社群特征、社群认同和品牌忠诚度之间的关系.研究结果显示,信息分享、感知价值、功能收益、共同意识都会通过社群认同正向影响品牌忠诚度,其影响重要程度为社群认同＞感知价值＞功能收益＞信息分享＞共同意识.研究结果为企业运营服装在线社群提供参考.     

Strategies To Design Selective Histone Deacetylase Inhibitors

This review classifies drug-design strategies successfully implemented in the development of histone deacetylase (HDAC) inhibitors, which have many applications including cancer treatment. Our focus is on especially demanded selective HDAC inhibitors and their structure-activity relationships in relation to corresponding protein structures. The main part of the paper is divided into six subsections each narrating how optimization of one of six structural features can influence inhibitor selectivity. It starts with the impact of the zinc binding group on selectivity, continues with the optimization of the linker placed in the substrate binding tunnel as well as the adjustment of the cap group interacting with the surface of the protein, and ends with the addition of groups targeting class-specific sub-pockets: the side-pocket-, lower-pocket- and foot-pocket-targeting groups. The review is rounded off with a conclusion and an outlook on the future of HDAC inhibitor design.     

The Adaptive Immune Landscape of the Colorectal Adenoma–Carcinoma Sequence

Background. The tumor immune microenvironment exerts a pivotal influence in tumor initiation and progression. The aim of this study was to analyze the immune context of sporadic and familial adenomatous polyposis (FAP) lesions along the colorectal adenoma–carcinoma sequence (ACS). Methods. We analyzed immune cell counts (CD3+, CD4+, CD8+, Foxp3+, and CD57+), tumor mutation burden (TMB), MHC-I expression and PD-L1 expression of 59 FAP and 74 sporadic colorectal lesions, encompassing adenomas with low-grade dysplasia (LGD) (30 FAP; 30 sporadic), adenomas with high-grade dysplasia (22 FAP; 30 sporadic), and invasive adenocarcinomas (7 FAP; 14 sporadic). Results. The sporadic colorectal ACS was characterized by (1) a stepwise decrease in immune cell counts, (2) an increase in TMB and MHC-I expression, and (3) a lower PD-L1 expression. In FAP lesions, we observed the same patterns, except for an increase in TMB along the ACS. FAP LGD lesions harbored lower Foxp3+ T cell counts than sporadic LGD lesions. A decrease in PD-L1 expression occurred earlier in FAP lesions compared to sporadic ones. Conclusions. The colorectal ACS is characterized by a progressive loss of adaptive immune infiltrate and by the establishment of a progressively immune cold microenvironment. These changes do not appear to be related with the loss of immunogenicity of tumor cells, or to the onset of an immunosuppressive tumor microenvironment.     

Dual Activity BLEG-1 from Bacillus lehensis G1 Revealed Structural Resemblance to B3 Metallo-β-Lactamase and Glyoxalase II: An Insight into Its Enzyme Promiscuity and Evolutionary Divergence

Metallo-β-lactamases (MBLs) are class B β-lactamases from the metallo-hydrolase-like MBL-fold superfamily which act on a broad range of β-lactam antibiotics. A previous study on BLEG-1 (formerly called Bleg1_2437), a hypothetical protein from Bacillus lehensis G1, revealed sequence similarity and activity to B3 subclass MBLs, despite its evolutionary divergence from these enzymes. Its relatedness to glyoxalase II (GLXII) raises the possibility of its enzymatic promiscuity and unique structural features compared to other MBLs and GLXIIs. This present study highlights that BLEG-1 possessed both MBL and GLXII activities with similar catalytic efficiencies. Its crystal structure revealed highly similar active site configuration to YcbL and GloB GLXIIs from Salmonella enterica, and L1 B3 MBL from Stenotrophomonas maltophilia. However, different from GLXIIs, BLEG-1 has an insertion of an active-site loop, forming a binding cavity similar to B3 MBL at the N-terminal region. We propose that BLEG-1 could possibly have evolved from GLXII and adopted MBL activity through this insertion.     

A log mining approach for process monitoring in SCADA

SCADA (supervisory control and data acquisition) systems are used for controlling and monitoring industrial processes. We propose a methodology to systematically identify potential process-related threats in SCADA. Process-related threats take place when an attacker gains user access rights and performs actions, which look legitimate, but which are intended to disrupt the SCADA process. To detect such threats, we propose a semi-automated approach of log processing. We conduct experiments on a real-life water treatment facility. A preliminary case study suggests that our approach is effective in detecting anomalous events that might alter the regular process workflow.     

Construction of discrete-time models for port-controlled Hamiltonian systems with applications

The issues of constructing a discrete-time model for Hamiltonian systems are in general different from those for dissipative systems. We propose an algorithm for constructing an approximate discrete-time model, which guarantees Hamiltonian conservation. We show that the algorithm also preserves, in a weaker sense, the losslessness property of a class of port-controlled Hamiltonian systems. An application of the algorithm to port-controlled Hamiltonian systems with quadratic Hamiltonian is presented, and we use this to solve the stabilization problem for this class of systems based on the approximate discrete-time model constructed using the proposed algorithm. We illustrate the usefulness of the algorithm in designing a discrete-time controller to stabilize the angular velocity of the dynamics of a rigid body.