Pathogenesis of Tobacco-Associated Lung Adenocarcinoma Is Closely Coupled with Changes in the Gut and Lung Microbiomes

Microbial dysbiosis has emerged as a modulator of oncogenesis and response to therapy, particularly in lung cancer. Here, we investigate the evolution of the gut and lung microbiomes following exposure to a tobacco carcinogen. We performed 16S rRNA-Seq of fecal and lung samples collected prior to and at several timepoints following (nicotine-specific nitrosamine ketone/NNK) exposure in Gprc5a^−/− mice that were previously shown to exhibit accelerated lung adenocarcinoma (LUAD) development following NNK exposure. We found significant progressive changes in human-relevant gut and lung microbiome members (e.g., Odoribacter, Alistipes, Akkermansia, and Ruminococus) that are closely associated with the phenotypic development of LUAD and immunotherapeutic response in human lung cancer patients. These changes were associated with decreased short-chain fatty acids (propionic acid and butyric acid) following exposure to NNK. We next sought to study the impact of Lcn2 expression, a bacterial growth inhibitor, given our previous findings on its protective role in LUAD development. Indeed, we found that the loss of Lcn2 was associated with widespread gut and lung microbiome changes at all timepoints, distinct from those observed in our Gprc5a^−/− mouse model, including a decrease in abundance and diversity. Our overall findings apprise novel cues implicating microbial phenotypes in the development of tobacco-associated LUAD.     

港口内运车辆作业轨迹异常检测

内运车是用于港口内部货物转运的车辆.如果在转运过程中缺乏监管,很容易造成偷货(将A货主的货转移至B货主堆位)、漏货(货物转运未经过计量设备)等行为,给港口带来严重的损失.为了有效杜绝这类情况的发生,提出轨迹真实状态序列提取方法并设计自适应有限状态机(Adaptive Finite State Machine,AFSM)...     

Green emitting β$\ubeta$-SiAlON:Eu2+ phosphors derived from chemically modified perhydropolysilazanes

We report the first synthesis of β-SiAlON:Eu²⁺ phosphors from single-source precursors, perhydropolysilazane (PHPS), chemically modified with Al(OCH(CH₃)₂)₃, and EuCl₂. The reactions occurring during the precursor synthesis and the subsequent thermal conversion of polymeric precursors into β-SiAlON:Eu²⁺ phosphors have been studied by a complementary set of analytical techniques, including infrared spectroscopy, gas chromatography–mass spectrometry, thermogravimetry–mass spectrometry, X-ray diffraction (XRD), photoluminescence spectroscopy, and scanning electron microscopy. It has been clearly established that Al(OCH(CH₃)₂)₃ immediately reacted with PHPS to afford N–Al bonds at room temperature, whereas N–Eu bond formation was suggested to proceed above 600°C accompanied by the elimination of HCl up to 1000°C in flowing N₂. The subsequent 1800°C-heat treatment for 1 h under an N₂ gas pressure at 980 kPa allowed converting the single-source precursors into fine-grained β-SiAlON:Eu²⁺ phosphors. XRD analysis revealed that the Al/Si of .09 was the critical atomic ratio in the precursor synthesis to afford single-phase β-SiAlON (z = .55). Moreover, Eu²⁺-doping was found to efficiently reduce the carbon impurity in the host β-SiAlON. The polymer-derived β-SiAlON:Eu²⁺ phosphors exhibited green emission under excitation at 460 nm and achieved the highest green emission intensity at the critical dopant Eu²⁺ concentration at 1.48 at%.     

组织学生参加化工原理课程竞赛的体会和思考

本文简单介绍了2010年北京地区普通高等学校巴斯夫杯化工原理课程竞赛的程序,详细介绍了参加竞赛对我校学生动手能力、团队合作精神、特别是相关课程学习兴趣的影响。参赛也发现了我校学生在本课程的学习和实验环节中存在提高的空间。     

Elimination of ƞ phase in WC–Co cemented carbides during laser powder bed fusion by powder coating compensation strategy

The formation of ƞ phase induced by the C-loss for the laser powder bed fusion (LPBF) of WC–Co cemented carbides largely deteriorates the fracture toughness. The current approach of mixing C additive into powder cannot mitigate the ƞ phase formation. This study proposed a new carbon compensation strategy of coating carbon resource on powder surface by fluidized bed chemical vapor deposition to address this issue. C nanoparticles and carbon nanotubes (CNTs) were selectively deposited on WC–Co powder to make uniform C- and CNTs-coated powders by tuning the deposition temperature. Compared with CNTs-coated powder and C–WC–Co powder mixtures, the C-coated powder was more effective in impeding the ƞ phase formation because it had higher reactivity and stronger dissolution ability to compensate the C-loss in the Co–W–C liquid. However, the single-carbon compensation was not enough to eliminate the ƞ phase due to the extreme nonequilibrium characteristics of LPBF, which required secondary heat treatment. The conventional heat treatment procedure of 1000°C for 3 h eliminated the ƞ phase for the C-coated powder but failed for the C–WC–12Co powder mixtures. Because of the absence of ƞ phase, the heat-treated sample made from C-coated powder exhibited the highest transverse rupture strength.     

建筑与结构设计之"合"——石上纯也与佐藤淳的合作访谈

现代建筑发展潮流中,日本建筑的设计风格独树一帜,新生代建筑师层出不穷,这离不开其独特的建筑文化环境,比如师承体系,与结构师之间的紧密合作等.此次访谈以建筑师与结构师的合作为主题,采访了石上纯也和佐藤淳两位先生,以了解和学习他们的工作模式.本文包括三部分:第一部分探讨合作模式,通过初期项目的讨论,阐述了双方合作开始的契机与发展,而海外项目中与当地事务所合作经验的对比,更显示出他们合作模式的独特性;第二部分探讨设计理念,通过两位老师在以往展览和建筑设计项目中关于自然的讨论,对场地的回应等,表达出他们彼此对建筑和结构设计理念的理解与思考;第三部分探讨对未来教育模式、新材料、新技术的建议与展望.