Symmetry-adapted cluster and symmetry-adapted cluster-configuration interaction method in the polarizable continuum model: Theory of the solvent effect on the electronic excitation of molecules in solution
Cammi R.,University of Parma |
Fukuda R.,Japan Institute for Molecular Science |
Fukuda R.,Japan Science and Technology Agency |
Ehara M.,Japan Institute for Molecular Science |
And 3 more authors.
Journal of Chemical Physics | Year: 2010
In this paper we present the theory and implementation of the symmetry-adapted cluster (SAC) and symmetry-adapted cluster-configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-specific approach, the advantage of which over the linear-response approach has been shown. The single-point energy calculation and its analytical energy derivatives are presented and implemented, where the free-energy and its derivatives are evaluated because of the presence of solute-solvent interactions. We have applied this method to s-trans-acrolein and metylenecyclopropene of their electronic excitation in solution. The molecular geometries in the ground and excited states were optimized in vacuum and in solution, and both the vertical and adiabatic excitations were studied. The PCM-SAC/SAC-CI reproduced the known trend of the solvent effect on the vertical excitation energies but the shift values were underestimated. The excited state geometry in planar and nonplanar conformations was investigated. The importance of using state-specific methods was shown for the solvent effect on the optimized geometry in the excited state. The mechanism of the solvent effect is discussed in terms of the Mulliken charges and electronic dipole moment. © 2010 American Institute of Physics.
Lee K.,SongDo Techno Park 7 50 Songdo Dong |
Pi K.,Venture Institute
Biochemistry (Moscow) | Year: 2010
We report the acid tolerance response and changes in the level of protein expression of probiotic Lactobacillus reuteri subjected to transient (1.5 h) acid stress at pH 3.0. Sixteen acid-responsive proteins were identified by peptide mass fingerprinting including members of five broad functional categories: metabolism, transcription/translation, DNA replica- tion/repair, transport and binding proteins, and pH homeostasis and stress responses. This work can provide some new and relevant information on the inducible mechanisms underlying the capacity of probiotic L. reuteri to tolerate acid stress. © Pleiades Publishing, Ltd., 2010.
Hasegawa J.-Y.,Kyoto University |
Hasegawa J.-Y.,Venture Institute |
Hasegawa J.-Y.,Japan Institute for Molecular Science |
Hasegawa J.-Y.,Hokkaido University |
And 3 more authors.
Journal of Chemical Theory and Computation | Year: 2012
Electronic excitations of chromophores in proteins and solutions are associated with the electronic response of the molecular environment. The underlying interactions are important origins of solvatochromism. We performed large-scale configuration interaction singles (CIS) calculations (up to 1000 atoms) for retinal chromophores in proteins and methanol solution, in which one-electron processes (polarization and charge-transfer effects of the environment) are included. The present approach also improved the electrostatic potential, as compared to that described by a molecular mechanics (MM) force field. The CIS results were combined with the symmetry adapted cluster (SAC)-CI result using our own N-layer integrated molecular orbital molecular mechanics (ONIOM) method. As compared to the MM description, the CIS reduces the calculated excitation energy by 0.1-0.3 eV and also improves the relative excitation energies among retinal proteins. We applied our localized molecular orbital (LMO) transformation scheme to analyze the CI wave functions. The result clarified the contributions of the amino acids. In bacteriorhodopsin, Tyr185 contributes intermolecular CT excitations. The radial distribution of amino acids contributions to the CI wave function was also analyzed. The results of the analysis are useful not only for understanding the molecular interactions and the role of amino acids in color tuning, but also for providing insight into the structure of the excited-state wave function for the molecular environment. An excitation-energy decomposition analysis also supported the results of the excited-state wave functions. © 2012 American Chemical Society.
Lee D.-H.,Gwangju Institute of Science and Technology |
Joo J.-Y.,Venture Institute |
Lee S.-K.,Gwangju Institute of Science and Technology
Optics Express | Year: 2015
This paper presents a model of blue laser diode (LD)-based white lighting coupled with a yellow YAG phosphor, for use in the proper design and fabrication of phosphor in automotive headlamps. First, the sample consisted of an LD, collecting lens, and phosphor was prepared that matches the model. The light distribution of the LD and the phosphor were modeled to investigate an effect of the surface topography and phosphor particle properties on the laser-driven white lighting systems by using the commercially available optical design software. Based on the proposed model, the integral spectrum distribution and the color coordinates were discussed. © 2015 Optical Society of America.
News Article | July 3, 2014
Unless you live in a cave, you’ll have noticed that Brazil is currently welcoming the FIFA World Cup 2014. For some reason I was expecting it would result in a news slowdown and well, I couldn’t have been more mistaken. Not only did this giant event bring its fair share of tech-related announcements, but startups also kept on working and closing new deals. Here are the news you can’t miss among all the noise: Let’s start with some interesting news bits from the World Cup itself. As we reported, each game has resulted in a huge amount of social chatter all around the world, with both Twitter and Facebook reaching records and expecting new heights over the next couple of weeks. Football aside, the mega-event has also been putting science in the spotlight, with coaches and referees relying on innovations such as goal-line technology, smart watches and wearable speed sensors to make fact-based decisions. Still, innovation hasn’t been getting as much attention as some of us wished. Indeed, controversy emerged on day one around the competition’s first kick. The fact that it was made by a person with paralysis using a mind-controlled exoskeleton was apparently not enough to grant it more than a few seconds air time. Here what you might have missed: As you can see, they are not completely self-explanatory, which might be one of several reasons why TV channels barely mentioned them during live coverage. Still, it would have been nice to hear more on the ongoing work behind them – the Walk Again Project, led by Brazilian neuroscientist Miguel Nicolelis from Duke University. It wasn’t the only controversy around the World Cup, whose tremendous cost spurred numerous protests in Brazil over the last few months. This discontent also echoed online, when hackers took down the event’s official site for a few hours on June 20. While there is no doubt that many Brazilians have more pressing needs than new stadiums, it still had a very positive impact for some of them. According to Airbnb, its platform reached a whole new scale with the event: Interestingly, some of Airbnb’s newest hosts are favela (slum) residents who discovered the wonders of the ‘sharing economy’ by renting out rooms to foreign tourists who couldn’t afford overpriced hotels – or were attracted by the breathtaking views you can get from the hills. Google made so many moves in Latin America this month that it deserves its own chapter. To begin with, it announced that it would finally pull the plug on Orkut, its first social network. As you may remember, Orkut was built ten years ago as a ‘20% project’ by a Google engineer named Orkut Büyükkökten. Although it never quite took off in most countries, it gained tremendous popularity in India and Brazil, where it took years for Facebook to steal its crown. It eventually did in early 2012, and Orkut entered a slow and steady decline, accelerated by Google’s indecisiveness. Considering its small number of active users left, the shutdown has been seen as somewhat of a non-event in most of the world. However, the reaction was different and more emotional in Brazil, where users took to… Twitter to share fond memories of their first social network. [Blogger Bianca Müller: “My birthplace on the Internet was Orkut.”] As for Orkut Büyükkökten, we recently learned that he was working on his next venture, Hello, a “one-of-a-kind community of users who celebrate friendship, imagination, self-expression, and authentic engagement in a safe environment.” Some of the other announcements made by Google this month were related to the World Cup, such as the addition of the event’s 12 host stadiums to its Street View service, following earlier updates to Google Transit and Google Indoor Maps. It is also worth mentioning that Google has been conducting a unique initiative to showcase Brazil’s World Cup through its now famous doodles. As Brazilian magazine explained in an interesting post (in Portuguese), a team of 4 doodlers even flew to Brazil to get closer to the action and create unique animated drawings. Unfortunately, they got briefly caught in controversy when one of its drawing wrongly attributed an Argentine province to Chile. However, the company was prompt to apologize and correct the error. Still in Brazil, Google recently conducted LTE tests in the state of Piaui as part of Project Loon, its initiative to provide balloon-powered Internet access. As we reported, Google was able to propel its high-altitude balloons into the air and connect a local school to the Internet for the very first time. The company also released its TV dongle Chromecast in the country, Estadão’s tech blog Link reported. The device is now available in several stores for R$199 (around $90 USD). Google is working on partnerships to expand its local content offering, currently limited to a popular kids’ show. Google also had news for Spanish-speaking countries, which accounted for 11 of the 12 new countries in which it recently rolled out Google Play’s bookstore. In addition to the Netherlands, the service is now available in Bolivia, Colombia, Costa Rica, Dominican Republic, Ecuador, El Salvador, Honduras, Nicaragua, Panama, Paraguay and Uruguay. A new job posting spotted by Link revealed that Apple was looking for a Brazilian engineer to “join the team that teaches Siri how to understand and speak new languages,” hinting at an upcoming release in Brazilian Portuguese. The company received mixed news regarding its iPhone brand, with Mexican company iFone winning a lawsuit against the country’s telcos for unauthorized use. On the other hand, a Brazilian judge confirmed that Apple could keep on using the “iPhone” brand in Brazil. Amazon is said to be negotiating with Brazilian manufacturers to start producing Kindle e-readers, Kindle Fire and its smartphone in the country, Blue Bus reported. This would represent a R$200 million investment (around $90.5 million USD). Telefónica introduced its mobile network Tuenti in Mexico, with a focus on young, connected users. Tuenti started out in Spain as a social network, before turning mostly into a niche pre-paid mobile operator following its acquisition by Telefónica. The service attracted around 200,000 clients in Spain, tech blog Hemerotek reported. Pinterest announced it would open an office in Brazil later this year, Telecompaper reported. According to Brazilian newspaper Folha de São Paulo, the social network has been working on hiring a team of 3 to 4 local employees. Starbucks’ clients in Mexico will soon be able to pay for their drinks through their smartphone,. Indeed, Mexico is about to become the 4th country in which the coffee chain rolls out its loyalty app, CNN Expansión reported. Still in Mexico, Sony launched its Video Unlimited movie service, giving customers in the country the ability to rent or purchase movie titles though the PlayStation Store, HD Report informed. Lastly, some companies included Latin American countries in recent global rollouts. PayPal expanded into 10 new countries, including Paraguay, Pulso Social reported. Line extended sales of its user-created stickers service Creators Market into 9 countries including Brazil. As for Microsoft-owned Yammer, its Web and mobile platforms now support Spanish and Portuguese, among other languages. Gone! released a new iOS app that lets users connect with potential buyers sell stuff they want “gone”, TechCrunch reported. As the app description page warns, the service is only available to invited users in SF and Austin (where Gone graduated from TechStars). However, it will be interesting to see whether it expands elsewhere in the future, considering that its founders are Argentine entrepreneurs. LATAMup’s startup map platform is now available in 6 cities: Buenos Aires, where its beta testing took place, as well as Bogotá, Lima, Rio de Janeiro, Santiago and São Paulo. Just like Represent.la, on which it is based, LATAMup’s maps let users locate key members of the local tech ecosystem, from accelerators and incubators to startups and co-working spaces. In Latin America, its main competitor is Startupmap.la, which fulfills the same mission. Brazilian fashion discovery startup Dujour launched a new e-commerce feature named Shop The Look to let users find similar items available to purchase in partner online stores. As you may remember, we previously listed Dujour as one of 12 Latin American startups to look out for in 2014. Mexican mobile point of sale company Sr. Pago launched an innovative product called Sr. Pago Card System. According to the company, it is “the first service in the Americas that combines a smartphone chip credit card reader with a debit card that can be reloaded with payments accepted through the card reader.” In practical terms, it means that small business owners could collect payments through a Sr. Pago terminal, and spend their earnings as they please with their connected debit card. “While the Sr. Pago card is available to consumers and small businesses in Mexico with traditional bank accounts, we see the greatest opportunity for impacting the underserved population in Mexico,” said Antonio Flores Aldama, CTO & COO of Sr. Pago. “This segment comprises approximately 61% of the population (more than 73 million people) whose payment and spending transactions are mostly cash based.” Argentine 3D printing company Trimaker partnered with Staples to commercialize its T-Element model in its home country. In addition, clients will be able to go to one of Staples’ stores in Buenos Aires to print 3D objects. Fellow Argentine startup Satellogic announced the successful launch (literally) of its third imaging nanosatellite, TechCrunch reported. Quoting the article: “The company was founded by CEO Emiliano Kargieman, who previously founded Core Security Technologies and came up with the vision for Satellogic while attending Singularity University in 2010. Describing existing satellite technology as “archaic,” Kargieman said he wants to launch a network of hundreds of satellites in Low Earth orbit that will allow customers to get “an image of any place on Earth in high-resolution and in real-time.” Brazilian commercial automation solution provider Bematech bought ERP software development company Unum, Exame reported. The deal carries an initial value of R$30 million ($13.6 million USD), which could followed by an additional R$10 million ($4.5 million USD) payment if certain goals are reached. Danish daily deal aggregator Bownty acquired Spanish competitor Yunait for an undisclosed amount, TechCrunch reported. In addition to the UK, Yunait operates in Southern Europe and in Latin America, which should help Bownty expand its international reach. CNN Expansión.com reported that its parent company Grupo Expansión was set to be acquired by investment fund Southern Cross pending on approval from Mexico’s antitrust commission. Grupo Expansión is a multi-platform publisher whose properties include 17 magazines and 11 websites. The deal would put an end to Time Inc.’s 9-year ownership of the company, but not to Grupo Expansión’s exploitation of Time media brands. European food ordering platform Delivery Hero acquired its Latin American counterpart PedidosYa, following a confidential partnership in place since 2013, the company announced on its blog. Originally from Uruguay, PedidosYa had expanded to Argentina Brazil, Chile, Colombia, Mexico, Peru, Puerto Rico and Venezuela. It had received funding from Atomico and Kaszek Ventures. Meanwhile, Rocket Internet’s food delivery service Foodpanda bought its Ecuadorian counterpart DeliYami, Gründerszene reported. Operating in Latin America under the HelloFood brand, Foodpanda was already present in Argentina, Brazil, Chile, Colombia, Mexico and Peru. In an interesting turn of events, Shoes4you is back from the dead. As you may remember, we wrote a post-mortem story about the company’s decision to close shop one year ago. However, it is now back online with a new owner, virtual shopping site MuccaShop, and a new business model. Instead of a Brazilian Shoedazzle, the site now operates as a traditional online retailer for third-party accessories – women’s shoes of course, but also jewelry and bags. Brazilian online advertising startup Adtrade was bought by French online marketing agency ESV Digital, LAVCA reported. The value of the transaction was not disclosed. Latino YouTube network MiTú raised $10 million in new funding round led by Upfront Ventures, with participation from previous backers, Recode reported. According to Crunchbase, “MiTú is one of the largest media brands dedicated to Latino content, with over 40 million subscribers and 400 million monthly video views, and covers topics from heath and food to pop culture. Founded in 2012, MiTú will use the latest funding to expand its presence in Los Angeles and Mexico City and build out engineering and sales efforts.” Event management startup Ingresse raised R$10 million ($4.5 million USD) in new funding, Startupi reported. The series B round was led by led by e.Bricks Early Stage, with participation from DGF Investimentos and Qualcomm. Wine e-commerce platform Evino raised R$10 million ($4.5 million USD) from a private investor who chose to remain anonymous, Startupi reported. In addition, co-founder Marcos Leal revealed that the company had previously received R$2 million ($908k USD) in funding from Project A Ventures. Start-Up Chile’s alum Review Trackers raised a $2 million investment round, the government-supported program reported. The funding round was led by Milwaukee’s CSA Partners, with investments from American Family Ventures, Jeff Rusinow, and SymphonyAlpha Ventures. Brazilian discount club Piggme raised R$ 3,2 million ($1.44 million USD) from Haya Investimentos, whose founder Marcelo Hayashi will join the company as Chief Strategy Officer, Startupi reported. Argentine company builder Quasar Ventures launched a new venture called Rodati.com with a $1 million investment. Participants include Quasar itself as well as NXTP Labs, Richmond Global and a group of angel investors based in both the USA and Latin America (disclosure: NXTP Labs is an investor in my startup, MonoLibre). According to its founders, Rodati is an Internet company that seeks to simplify the new car buying experience in Latin America. Miami-based venue recommendation startup Posto7 raised $925k in seed funding from NXTP Labs and other investors in New York City, San Francisco, Brazil and Miami, TechCocktail reported. The company recently graduated from NXTP Labs as part of its 6th acceleration batch (Disclosure: so did my startup). Argentine startup BitPagos raised a seed round of $600k led by Pantera Capital, Tim Draper, Barry Silbert, Boost Bitcoin Fund, Amasia and others, Venture Capital Dispatch reported. The company lets hotels accept bookings paid either in dollars or with bitcoins to bypass Argentina’s currency hurdles. Spanish development outsourcing platform Yeeply raised €320k ($437k USD) from various sources. According to Pulso Social, the Plug & Play Spain alum plans to use this funding to grow its freelancing community in Latin America. Colombian online pharmacy Pidefarma.com raised investment from Axon Partners Group, Pulso Social reported. The Wayra Colombia alum plans to use this funding to boost its growth and expand into other countries. Brazilian mobile content company Movile and Brazilian-American accelerator 21212 co-invested an undisclosed amount in personalized playlist generator Superplayer. The startup hopes to boost use of its mobile apps following the investment. Corporate education company Inbep received investment from Altivia Ventures, Startupi reported. It previously received funding from an angel investor and a personal investment from Altivia Ventures’ founder Cassio Spina. Miami-based mobile wallet solution Waleteros won this year GeekTank’s competition, the Miami Herald’s blog Starting Gate reported. As journalist Nancy Dahlberg noted, “Waleteros targets the 5 million Hispanics in the United States who are unbanked or underbanked, many of whom deal with check cashing stores now.” Latino-focused initiative Manos Accelerator announced the list of companies that would join its Silicon Valley-based program, Pulso Social reported. While US-based companies accounted for half of the applications, 4 of the 7 selected startups come from Latin American countries. Government-backed initiative Startup Brasil had to amend its list of partner accelerators, Startupi reported. The program took to its blog to announce that Pipa would replace Papaya Ventures, which apparently “interrupted its activities” (see our previous post mentioning both accelerators). The Multilateral Investment Fund (FOMIN in its Spanish acronym) approved a $2 million equity investment in Venture Innovation Fund II. The fund will be managed by Venture Partners, LP, founders of the Venture Institute accelerator in Mexico City, and support up to 14 early-stage startups. Newsgames are on the rise in Latin America, with more and more media outlets having a stab at creating innovative formats. A couple of weeks ago, Argentine fact-checking platform Chequeado launched Chequeate, a trivia quiz game available on its website and as an Android app, Infotechnology reported. As for Brazilian newspaper Folha de São Paulo, it unveiled a newsgame called ‘O Mundo da Copa’ to let readers (and football fans) learn more about “World Cup’s world”. A new platform was also born to keep up with this surge: Newsgame Vault, an online directory of newsgames. It was created in Brazil by Mario Lima Cavalcanti, editor of website for Brazilian online journos ‘Jornalistas da Web’. However, its perspective is global and it features projects from all around the world. Argentina’s National Communications Commission asked ISPs to block access to The Pirate Bay, newspaper La Nación reported. The controversial measure is part of an ongoing lawsuit filed by the Argentinian Chamber of Phonogram & Videogram Producers (CAPIF in its Spanish acronym). In retaliation, its website was temporarily hacked… and turned “into a fully functioning and blockade-circumventing Pirate Bay proxy,” TorrentFreak reported. Mexico’s National Council for Science and Technology (CONACYT in its Spanish acronym) distanced itself from a sexist lecture given during the 5th edition of Campus Party that took place in Zapopan a few days ago, while issuing an apology and reinstating its support for gender equality. The event organizer Movistar Campus Party also apologized while removing all references to the talk, titled “Como hackear al sexo femenino” (which roughly translates as “How to hack females”). Many voices had expressed outrage at this incident, but also at a company’s appalling decision to hire a ‘booth babe’ and place a giant QR code on her buttocks. In less depressing news, San Francisco is setting up a new structure called LatinSF to attract Latin American companies, SFGate reported. It is similar to ChinaSF, which brought 47 Chinese companies to the city so far. According to SFGate, San Francisco’s Office of Economic and Workforce Development is “in the “final stages” of hiring the head of the LatinSF operation and is rounding up $100,000 from private donors to match the city’s contribution, seems all set to go.” Puerto Rico unveiled a project nicknamed ‘Gigabit Island.’ It consists of a $17 million investment to create an ultra-high-speed Internet network to serve its tech sector. The announcement was made during the island’s annual Tech Summit event, which also featured a hackathon focused on public services. According to its promoters, the new network will reach the same speed of one gigabyte per second as Google Fiber’s pilot project in Kansas City. Cuban authorities declared interest in attracting foreign investment in a series of sectors, including electronics, the Latin American Herald Tribune reported. However, it remains to be seen which companies could be keen to invest in a country which recently clamped down on Wi-Fi networks. In a long-planned visit on the island, Google’s executive chairman Eric Schmidt “promoted the virtues of a free and open Internet”, independent Cuban media outlet 14ymedio reported.