California NanoSystems Institute Research Articles

Fluxionality of Catalytic Clusters: When It Matters and How to Address It

Viewpoint pubs.acs.org/acscatalysis Fluxionality of Catalytic Clusters: When It Matters and How to Address It Huanchen Zhai † and Anastassia N. Alexandrova* ,†,‡ Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States California NanoSystems Institute, Los Angeles, California 90095, United States 1. INTRODUCTION Small clusters secured at a given size, for example, via deposition on surfaces of semiconductors, can be remarkable catalysts. In the so-called “non-scalable” regime, where every atom and every electron counts in catalyst tuning, 1−4 the opportunities for design are vast and intellectually attractive. At the same time, these systems are incredibly complex to characterize. In particular, in the nonscalable regime, clusters have shapes that are far from being idealized cuts out of the bulk, especially in the presence of adsorbates (reactants, intermediates, products of the reaction) and the support. Instead, cluster shapes can be highly diverse and hardly ever obey our intuition, which is uncomfortably weak in this case. One problem then is to identify the most stable structure, the global minimum. Many efficient Global Optimization (GO) algorithms, including Generic Algorithm (GA), 5−8 Particle Swarm Optimization (PSO), 9,10 Simulated Annealing (SA), 11 and Basin Hopping (BH) 12,13 have been shown to be successfully applied to small cluster systems, when combined with different level ab initio electronic structure methods. In addition, the GO algorithms can be further accelerated by using potential energy surface fitting techniques 14−16 or empirical potentials, 17,18 where the latter can be particularly useful for significantly larger clusters. 19 However, even if the global minimum is found, just the global minimum may tell only part of the story. Potential energy surfaces of clusters are typically rich in low- energy local minima. Many of these isomers are energetically accessible at the elevated temperatures of catalysis, to the degree that thermodynamic equilibration is kinetically possible. For example, the gas-phase Pt 8 cluster has ca. 30 distinct isomers (local minima) within the vicinity of the global minimum that can be populated at 700 K. 14 Of course, it is possible that some isomers are protected kinetically by high barriers, especially when the supporting surface provides strong and selective interactions with certain isomers. Regardless, several isomers should be suspected to be present in the catalytic system. This calls for a statistical ensemble representation of the catalyst. Furthermore, the most stable isomer may not be the most catalytically active. After all, it is intuitive that less-stable species are more likely to be reactive. For example, consider catalytic Au clusters versus stable and inert bulk Au. Thus, if there exists a relationship between the catalytic efficiency of a cluster isomer and its relative stability, then it is more likely to be inversely proportional than otherwise. In summary, even if the global minimum of a cluster is found, the utility of this isomer alone in describing size- specific catalytic activities is likely limited. A cartoon illustration of this point is shown in Figure 1. © 2017 American Chemical Society Figure 1. Conditions of catalysis (A) do not imply a single rigid cluster isomer facilitating a single catalytic event in vacuum (B), but instead, realistic coverage, temperature T, pressure p, access to many cluster isomers (% in C indicating probabilities for occurrences), and fluxionality all have an influence on catalyst activity. Thus, a statistical ensemble representation of the catalyst isomers under catalytic thermal conditions is necessary. The situation is further complicated by the fact that isomers may interconvert from one to another under the influence of increased temperature and because of the changing amount and chemical nature of adsorbates 20,21 (for example, reactants versus reaction intermediates). This phenomenon is called fluxionality, and it is the topic of the present article. From our point of view, the most difficult question is that of the interdependence and the interaction between the catalyzed reaction and cluster isomer interconversion. Clusters covered with reactants may have a different preferred shape or an ensemble of shapes than those covered with reaction intermediates or products. However, does it mean that the cluster rearranges in the course of the reaction step, that is, part of the reaction coordinate? Alternatively, does it mean that the clusters interconvert from one to another within the given free- energy well (say that of the reactants) and, once a particularly catalytic isomer forms in this process of equilibration, the reaction proceeds with a very small barrier? If the latter is the case, then, once the next reaction intermediate is formed, the clusters may again re-equilibrate in the new free-energy well. The generally longer lifetime in the wells should allow for this. At the moment, there is a controversy and a general lack of clarity on this question. How can we begin thinking about it? Received: November 15, 2016 Published: January 27, 2017 DOI: 10.1021/acscatal.6b03243 ACS Catal. 2017, 7, 1905−1911

Inside Back Cover: Infinite Polyiodide Chains in the Pyrroloperylene–Iodine Complex: Insights into the Starch–Iodine and Perylene–Iodine Complexes (Angew. Chem. Int. Ed. 28/2016)

Inside Back Cover: Infinite Polyiodide Chains in the Pyrroloperylene–Iodine Complex: Insights into the Starch–Iodine and Perylene–Iodine Complexes (Angew. Chem. Int. Ed. 28/2016)

New Technique Greatly Enhances Digital Microscopy Images

Optik & PhotonikVolume 11, Issue 1 p. 12-12 Research & TechnologyFree Access New Technique Greatly Enhances Digital Microscopy Images Researchers from the California NanoSystems Institute at UCLA have created a new technique that greatly enhances digital microscopy images First published: 18 February 2016 https://doi.org/10.1002/opph.201690008AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue1February 2016Pages 12-12 ReferencesRelatedInformation

AEG-1 activates Wnt/PCP signaling to promote metastasis in tongue squamous cell carcinoma

Despite advances in therapy, survival among patients with locally advanced squamous cell carcinoma of tongue (TSCC) and cervical lymph node metastasis remains dismal. Here, we estimated the functional effect of AEG-1 on TSCC metastasis and explored the molecular mechanism by which AEG-1 stimulates epithelial-mesenchymal transition (EMT). We initially found that AEG-1 mRNA levels were much higher in metastatic TSCC than in non-metastatic TSCC and that AEG-1 expression strongly correlates with EMT status. Receiver operating characteristic analysis showed that the combined AEG-1 and EMT statuses are predictive of the survival rate among TSCC patients. In addition, AEG-1 knockdown inhibited EMT in cultured TSCC cell lines and in a xenograft-mouse model. Recombinant AEG-1 activated Wnt/PCP-Rho signaling, and its stimulatory effects on TSCC cell invasiveness and EMT were reversed by an anti-Wnt5a neutralizing antibody or by inhibition of Rac1 or ROCK. These results highlight the critical stimulatory effect of AEG-1 on cancer cell invasiveness and EMT and indicate that AEG-1 may be a useful prognostic biomarker for TSCC patients.

Applications of Plasmon Energy Expansion Thermometry

1. Center for Electron Microscopy and Microanalysis, University of Southern California, Los Angeles, CA, USA. 2. Department of Physics and Astronomy & California NanoSystems Institute, University of California, Los Angeles, CA, USA. 3. Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA 4. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.

Reply to “Comment on ‘Three-dimensional imaging of a phase object from a single sample orientation using an optical laser’ ”

Chien-Chun Chen,1 Huaidong Jiang,2 Lu Rong,1 Sara Salha,1 Rui Xu,1 Thomas G. Mason,1,3 and Jianwei Miao1 1Department of Physics & Astronomy and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA 2State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People’s Republic of China 3Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA (Received 25 September 2012; published 13 December 2012)

Development of Pharmaceutically Adapted Mesoporous Silica Nanoparticles Platform.

ADVERTISEMENT RETURN TO ISSUEGuest CommentaryNEXTDevelopment of Pharmaceutically Adapted Mesoporous Silica Nanoparticles PlatformHuan Meng†, Min Xue‡, Jeffrey I. Zink*‡§, and Andre E. Nel*†§View Author Information† § †Division of NanoMedicine, Department of Medicine, ‡Department of Chemistry & Biochemistry, and §California NanoSystems Institute, University of California, Los Angeles, United States*E-mail: [email protected] (A.E.N.); [email protected] (J.I.Z.).Cite this: J. Phys. Chem. Lett. 2012, 3, 3, 358–359Publication Date (Web):February 2, 2012Publication History Received6 January 2012Accepted12 January 2012Published online2 February 2012Published inissue 2 February 2012https://doi.org/10.1021/jz300021xCopyright © 2012 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1431Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (159 KB) Get e-AlertsSUBJECTS:Drug delivery,Electron paramagnetic resonance spectroscopy,Genetics,Nanoparticles,Tumors Get e-Alerts

Nanomaterials in the Environment: From Materials to High-Throughput Screening to Organisms

One of the challenges in the field of nanotechnology is environmental health and safety (EHS), including consideration of the properties of engineered nanomaterials (ENMs) that could pose dangers to the environment. Progress in the field of nanomaterial development and nanotoxicology was presented at the International Conference on the Environmental Implications of Nanotechnology at the California NanoSystems Institute (CNSI) on the UCLA campus on May 11-14, 2010. This event was cohosted by the University of California Center for the Environmental Implications of Nanotechnology (UC CEIN) and the Center for the Environmental Implications of NanoTechnology (CEINT) based at Duke University. Participants included scientists and scholars from various backgrounds, including chemistry, biology, engineering, nanomaterial science, toxicology, ecology, mathematics, sociology, and policy makers. The topics of discussion included safety evaluation of ENMs from an environmental perspective, nanotoxicology, ecotoxicology, safe design of ENMs, environmental risk assessment, public perception of nanotechnology, application of ENMs in consumer products, and many more. The UC CEIN presented data on their predictive toxicological approach to the assessment of ENM libraries, which were designed and synthesized to develop an understanding of the material properties that could lead to hazard generation at the cellular and organismal levels in the environment. This article will focus on the first metal oxide ENM library that was introduced to harmonize research activities in the UC CEIN, with particular emphasis on the safety assessment of ZnO on cells and organisms. Methods of decreasing the observed toxic effects will also be discussed as an integral component of the UC CEIN's activity in developing safer nanomaterials to lessen their environmental impacts.

Profile: Patrick Soon-Shiong

Dr Patrick Soon-Shiong is the Executive Director of the UCLA Wireless Health Institute, and Professor of Microbiology, Immunology, Molecular Genetics and Bioengineering at UCLA. He is a fellow of both the American College of Surgeons and the Royal College of Physicians and Surgeons of Canada. He serves on the Board of Directors for the National Institute of Transplantation, the Technology Council for the Center for Cancer Nanotechnology Excellence at Northwestern University, which is part of the National Cancer Institute's (NCI) five-year initiative for nanotechnology in cancer research. He serves on the RAND Health Board of Advisors and the President's Council at RAND, the Board of Trustees for the Saint John's Health Center, the Advisory Board of the California NanoSystems Institute at UCLA, the Advisory Board for the Institute for Technology Advancement (ITA) at UCLA School of Engineering, the Board of Councillors of the USC Viterbi School of Engineering, and the Arizona Commerce Authority Board. He is a founding board member of the Dossia Foundation, a non-profit consortium of large employers (Wal-Mart, AT&T, BP America, Intel, Pitney Bowes, Cardinal Health, Sanofi-Aventis, Applied Materials, and Vanguard) that seek to enhance consumer engagement in their own healthcare through use of personal health records. In 2009, he was appointed by Attorney General Cuomo to the board of FAIR Health, a new not-for-profit entity to facilitate nationwide reform of consumer reimbursement for out of network healthcare charges.

Introducing, OncoTarget

// Weiling He 1, 2, ‡ , Di Xu 3, ‡ , Zhuo Wang 1, ‡ , Xianhong Xiang 4, ‡ , Bing Tang 2 , Shuhua Li 1 , Minzhi Hou 1 , Yang Zhang 5 , Jie-Fu Chen 6 , Millicent Lin 6 , Liantang Wang 1 , Shuang Hou 6 , Hsian-Rong Tseng 6 , Ming Kuang 7, * , Zun-fu Ke 1, * 1 Department of Pathology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Province Guangdong, P.R. China 2 Department of Gastrointestinal Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Province Guangdong, P.R. China 3 Department of Thoracic Surgery, The Central Hospital of Wuhan, Jiang'an District, Wuhan, Hubei Province 430014, P.R. China 4 Department of Interventional Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Province Guangdong, P.R. China 5 Biomedical Engineering, University of Texas at El Paso, El Paso, Texas 79968, United States 6 Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging (CIMI), California NanoSystems Institute (CNSI), University of California, Los Angeles, California 90095-1770, United States 7 Department of Hepatobiliary Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Province Guangdong, P.R. China ‡ These authors have contributed equally to this work *Correspondence to: Ming Kuang, e-mail: kuangminda@hotmail.com Zun-fu Ke, e-mail: kezunfu@126.com Keywords: nanomaterials, microfluidics, circulating tumor cell, lung cancer, diagnostics Received: December 06, 2015 Accepted: March 06, 2016 Published: March 23, 2016 ABSTRACT Circulating tumor cells (CTC) shows great prospect to realize precision medicine in cancer patients. We developed the NanoVelcro Chip integrating three functional mechanisms. NanoVelcro CTC capture efficiency was tested in advanced NSCLC. Further, ALK-rearrangement status was examined through fluorescent in situ hybridization in CTCs enriched by NanoVelcro. NanoVelcro system showed higher CTC-capture efficiency than CellSearch in advanced NSCLC. CTC counts obtained by both methods were positively correlated (r=0.45, p<0.05). Further, CTC counts enriched by NanoVelcro correlated to the pTNM stage but CellSearch. All ALK-positive patients had 3 or more ALK-rearranged CTC per mL of blood. Less than 3 ALK-rearranged CTC was detected in ALK-negative patients. NanoVelcro can detect the ALK–rearranged status with consistent sensitivity and specificity compared to biopsy test. Furthermore, the ALK-rearranged CTC ratio correlated to the pTNM stage in ALK-positive patients. Following up with CTC enumeration by NanoVelcro and CellSearch observed their variations in reflecting clinical response of crizotinib treatment. NanoVelcro provides a sensitive method for CTC counts and characterization in advanced NSCLC. ALK-rearrangement can be detected in CTCs collected from advanced NSCLC patients by NanoVelcro, facilitating diagnostic test and prognosis analysis, most importantly offering one noninvasive method for real-time monitoring of treatment reaction.

Honeycomb Carbon: A Review of Graphene

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTHoneycomb Carbon: A Review of GrapheneMatthew J. Allen†, Vincent C. Tung‡, and Richard B. Kaner*†‡View Author Information Department of Chemistry and Biochemistry and California NanoSystems Institute, and Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095†Department of Chemistry and Biochemistry and California NanoSystems Institute.‡Department of Materials Science and Engineering and California NanoSystems Institute.Cite this: Chem. Rev. 2010, 110, 1, 132–145Publication Date (Web):July 17, 2009Publication History Received20 February 2009Published online17 July 2009Published inissue 13 January 2010https://doi.org/10.1021/cr900070dCopyright © 2009 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views82732Altmetric-Citations5464LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (3 MB) Get e-AlertsSUBJECTS:Anode materials,Carbon,Deposition,Layers,Two dimensional materials Get e-Alerts

Improvement of Photoluminescent and Photovoltaic Properties of Poly(thienylene vinylene) by Carboxylate Substitution

Department of Materials Science and Engineering & CaliforniaNanosystems Institute, University of California at Los Angeles,Los Angeles, California 90095Received April 17, 2009Revised Manuscript Received May 27, 2009Conjugated polymers have been a popular research field inthepastthreedecadessincethediscoveryofconductingpolymersin 1977,

Addressing Diversity in STEM Education: Authenticity and Integration

AbstractThis talk will reflect on the challenges of designing educational opportunities that broaden diversity in the ranks of future scientists and engineers. The speaker, who is Education Director at the California Nanosystems Institute (CNSI) at the University of California, Santa Barbara, will report on the design and evaluation of a program that integrates academic, career and social components to engage a community of undergraduates, graduate mentors and research faculty at UCSB. The program builds on key practices such as academic mentorship, community networking and early undergraduate research. Evaluation of this program, Expanding Pathways to Science, Engineering and Mathematics (EPSEM) indicates that it has been successful in recruiting and retaining students from under-represented (URM) groups into science, technology, engineering and math disciplines (STEM disciplines).

Silicatein and the Translation of its Molecular Mechanism of Biosilicification into Low Temperature Nanomaterial Synthesis

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTSilicatein and the Translation of its Molecular Mechanism of Biosilicification into Low Temperature Nanomaterial SynthesisRichard L. Brutchey† and Daniel E. Morse*‡View Author Information Institute for Collaborative Biotechnologies, California NanoSystems Institute, the Materials Research Laboratory, and the Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California 93106, and Department of Chemistry, University of Southern California, Los Angeles, California 90089* Corresponding author: e-mail, [email protected]†University of Southern California.‡University of California, Santa Barbara.Cite this: Chem. Rev. 2008, 108, 11, 4915–4934Publication Date (Web):September 5, 2008Publication History Received3 December 2007Published online5 September 2008Published inissue 12 November 2008https://doi.org/10.1021/cr078256bCopyright © 2008 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views4912Altmetric-Citations208LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (5 MB) Get e-AlertsSUBJECTS:Hydrolysis,Monomers,Oxides,Peptides and proteins,Silica Get e-Alerts

Acoustics of a large immersive environment, The Allosphere

The Allosphere is a new audio/visual immersion space for the California Nanosystems Institute at The University of California, Santa Barbara, used for both scientific and performing-arts studies. This three-story sphere with central-axis catwalk permits an unusually large experiential region. The huge perforated-metal visual-projection sphere, with its principle listening locations centered inside the sphere, introduces multiple considerations and compromises, especially since the ideal acoustical environment is anechoic. Video projection requires opaque light reflectivity of the concave projection surface, while audio solicits extreme sound transmissibility of the screen plus full-range sound absorptivity outside the sphere. The design requires high-fidelity spatialization of a large number of simulated sound sources over a large region near the core, and support of vector-based amplitude panning, Ambisonic playback, and wave-field synthesis. This paper discusses considerations that both conform to, and lie outside of, traditional acoustical analysis methodologies, and briefly reviews the electroacoustic systems design.