News Article | May 19, 2017
Fifty years ago, physicists in the US established a new laboratory and with it a new approach to carrying out frontier research in high-energy physics. Il y a cinquante ans, des physiciens ont créé aux États-Unis un nouveau laboratoire, et dans la foulée une nouvelle manière de mener des recherches de pointe en physique des hautes énergies. Appelé initialement National Accelerator Laboratory et rebaptisé Fermilab quelques années plus tard, le laboratoire a eu comme première grande installation un accélérateur de 200 GeV, lequel a ouvert la voie au collisionneur Tevatron et aux grandes découvertes telles que celle du quark t. Aujourd’hui, le Fermilab se consacre principalement aux études à la frontière des hautes intensités et à la compréhension des propriétés des neutrinos, perpétuant ainsi les rêves d’exploration et de découverte de son premier directeur, Robert Wilson. In 1960, two high-energy physics laboratories were competing for scientific discoveries. The first was Brookhaven National Laboratory on Long Island in New York, US, with its 33 GeV Alternating Gradient Synchrotron (AGS). The second was CERN in Switzerland, with its 28 GeV Proton Synchrotron (PS). That year, the US Atomic Energy Commission (AEC) received several proposals to boost the country’s research programme focusing on the construction of new accelerators with energies between 100–1000 GeV. A joint panel of president Kennedy’s Presidential Science Advisory Committee and the AEC’s General Advisory Committee was formed to consider the submissions, chaired by Harvard physicist and Manhattan Project veteran Norman Ramsey. By May 1963, the panel had decided to have Ernest Lawrence’s Radiation Laboratory in Berkeley, California, design a several-hundred GeV accelerator. The result was a 200 GeV synchrotron costing approximately $340 million. When Cornell physicist Robert Rathbun Wilson, a student of Lawrence’s who also worked on the Manhattan Project, saw Berkeley’s plans he considered them too conservative, unimaginative and too expensive. Wilson, being a modest yet proud man, thought he could design a better accelerator for less money and let his thoughts be known. By September 1965, Wilson had proposed an alternative, innovative, less costly (approximately $250 million) design for the 200 GeV accelerator to the AEC. The Joint Committee on Atomic Energy, the congressional body responsible for AEC projects and budgets, approved of his plan. During this period, coinciding with the Vietnam war, the US Congress hoped to contain costs. Yet physicists hoped to make breakthrough discoveries, and thought it important to appeal to national interests. The discovery of the Ω– particle at Brookhaven in 1964 led high-energy physicists to conclude that “an accelerator ‘in the range of 200–1000 BeV’ would ‘certainly be crucial’ in exploring the ‘detailed dynamics of this strong SU(3) symmetrical interaction’.” Simultaneously, physicists were expressing frustration with the geographic situation of US high-energy physics facilities. East and West Coast laboratories like Lawrence Berkeley Laboratory and Brookhaven did not offer sufficient opportunity for the nation’s experimental physicists to pursue their research. Managed by regional boards, the programmes at these two labs were directed by and accessible to physicists from nearby universities. Without substantial federal support, other major research universities struggled to compete with these regional laboratories. Against this backdrop arose a major movement to accommodate physicists in the centre of the country and offer more equal access. Columbia University experimental physicist Leon Lederman championed “the truly national laboratory” that would allow any qualifying proposal to be conducted at a national, rather than a regional, facility. In 1965, a consortium of major US research universities, Universities Research Association (URA), Inc., was established to manage and operate the 200 GeV accelerator laboratory for the AEC (and its successor agencies the Energy Research and Development Administration (ERDA) and the Department of Energy (DOE)) and address the need for a more national laboratory. Ramsey was president of URA for most of the period 1966 to 1981. Following a nationwide competition organised by the National Academy of Sciences, in December 1966 a 6800 acre site in Weston, Illinois, around 50 km west of Chicago, was selected. Another suburban Chicago site, north of Weston in affluent South Barrington, had withdrawn when local residents “feared that the influx of physicists would ‘disturb the moral fibre of their community’”. Robert Wilson was selected to direct the new 200 GeV accelerator, named the National Accelerator Laboratory (NAL). Wilson asked Edwin Goldwasser, an experimental physicist from the University of Illinois, Urbana-Champaign, and member of Ramsey’s panel, to be his deputy director and the pair set up temporary offices in Oak Brook, Illinois, on 15 June 1967. They began to recruit physicists from around the country to staff the new facility and design the 200 GeV accelerator, also attracting personnel from Chicago and its suburbs. President Lyndon Johnson signed the bill authorising funding for the National Accelerator Laboratory on 21 November 1967. It wasn’t easy to recruit scientific staff to the new laboratory in open cornfields and farmland with few cultural amenities. That picture lies in stark contrast to today, with the lab encircled by suburban sprawl encouraged by highway construction and development of a high-tech corridor with neighbours including Bell Labs/AT&T and Amoco. Wilson encouraged people to join him in his challenge, promising higher energy and more experimental capability than originally planned. He and his wife, Jane, imbued the new laboratory with enthusiasm and hospitality, just as they had experienced in the isolated setting of wartime-era Los Alamos while Wilson carried out his work on the Manhattan Project. Wilson and Goldwasser worked on the social conscience of the laboratory and in March 1968, a time of racial unrest in the US, they released a policy statement on human rights. They intended to: “seek the achievement of its scientific goals within a framework of equal employment opportunity and of a deep dedication to the fundamental tenets of human rights and dignity…The formation of the Laboratory shall be a positive force…toward open housing…[and] make a real contribution toward providing employment opportunities for minority groups…Special opportunity must be provided to the educationally deprived…to exploit their inherent potential to contribute to and to benefit from the development of our Laboratory. Prejudice has no place in the pursuit of knowledge…It is essential that the Laboratory provide an environment in which both its staff and its visitors can live and work with pride and dignity. In any conflict between technical expediency and human rights we shall stand firmly on the side of human rights. This stand is taken because of, rather than in spite of, a dedication to science.” Wilson and Goldwasser brought inner-city youth out to the suburbs for employment, training them for many technical jobs. Congress supported this effort and was pleased to recognise it during the civil-rights movement of the late 1960s. Its affirmative spirit endures today. When asked by a congressional committee authorising funding for NAL in April 1969 about the value of the research to be conducted at NAL, and if it would contribute to national defence, Wilson famously answered: “It has only to do with the respect with which we regard one another, the dignity of men, our love of culture…It has to do with, are we good painters, good sculptors, great poets? I mean all the things we really venerate and honour in our country and are patriotic about. It has nothing to do directly with defending our country except to help make it worth defending.” Wilson, who had promised to complete his project on time and under budget, perceived of the new laboratory as a beautiful, harmonious whole. He felt that science, technology, and art are importantly connected, and brought a graphic artist, Angela Gonzales, with him from Cornell to give the laboratory site and its publications a distinctive aesthetic. He had his engineers work with a Berkeley colleague, William Brobeck, and an architectural-engineering group, DUSAF, to make designs and cost estimates for early submissions to the AEC, in time for their submissions to the congressional committees that controlled NAL’s budget. Wilson appreciated frugality and minimal design, but also tried to leave room for improvements and innovation. He thought design should be ongoing, with changes implemented as they are demonstrated, before they became conservative. There were many decisions to be made in creating the laboratory Wilson envisioned. Many had to be modified, but this was part of his approach: “I came to understand that a poor decision was usually better than no decision at all, for if a necessary decision was not made, then the whole effort would just wallow – and, after all, a bad decision could be corrected later on,” he wrote in 1987. An example was the magnets in the Main Ring, the first name of the 200 GeV synchrotron accelerator, which had to be redesigned as did the plans for the layout of the experimental areas. Even the design of the distinctive Central Laboratory building, constructed after the accelerator achieved its design energy and renamed Robert Rathbun Wilson Hall in 1980, had to have certain adjustments from its initial concepts. Wilson said that “a building does not have to be ugly to be inexpensive” and he orchestrated a competition among his selected architects to create the final design of this visually striking structure. To save money he set up competitions between contractors so that the fastest to finish a satisfactory project were rewarded with more jobs. Consequently, the Main Ring was completed on time by 30 March 1972 and under the $250 million budget. NAL was dedicated and renamed Fermilab on 11 May 1974. Experimentalists from Europe and Asia flocked to propose research at the new frontier facility in the US, forging larger collaborations with American colleagues. Its forefront position and philosophy attracted the top physicists of the world, with Russian physicists making news working on the first approved experiment at Fermilab in the height of the Cold War. Congress was pleased and the scientists were overjoyed with more experimental areas than originally planned and with higher energy, as the magnets were improved to attain 400 GeV and 500 GeV within two years. The higher energy in a fixed-target accelerator complex allowed more innovative experiments, in particular enabling the discovery of the bottom quark in 1977 (see "Revisiting the b revolution"). Fermilab’s early intellectual environment was influenced by theoretical physicists Robert Serber, Sam Trieman, J D Jackson and Ben Lee, who later brought Chris Quigg and Bill Bardeen, who in turn invited many distinguished visitors to add to the creative milieu of the laboratory. Already on Wilson’s mind was a colliding-beams accelerator he called an “energy doubler”, which would employ superconductivity, and he had established working groups to study the idea. But Wilson encountered budget conflicts with the AEC’s successor, the new Department of Energy, which led to his resignation in 1978. He joined the faculties of the University of Chicago and Columbia University briefly before returning to Cornell in 1982. Fermilab’s future was destined to move forward with Wilson’s ideas of superconducting-magnet technology, and a new director was sought. Lederman, who was spokesperson of the Fermilab study that discovered the bottom quark, accepted the position in late 1978 and immediately set out to win support for Wilson’s energy doubler. An accomplished scientific spokesman, Lederman achieved the necessary funding by 1979 and promoted the energy-enhancing idea of introducing an antiproton source to the accelerator complex to enable proton–antiproton collisions. Experts from Brookhaven and CERN, as well as the former USSR, shared ideas with Fermilab physicists to bring superconducting-magnet technology to fruition at Fermilab. Under the leadership of Helen Edwards, Richard Lundy, Rich Orr and Alvin Tollestrup, the Main Ring evolved into the energy doubler/saver in 1983 with a new ring of superconducting magnets installed below the early Main Ring magnets. This led to a trailblazing era during which Fermilab’s accelerator complex, now called the Tevatron, would lead the world in high-energy physics experiments. By 1985 the Tevatron had achieved 800 GeV in fixed-target experiments and 1.6 TeV in colliding-beam experiments, and by the time of its closure in 2011 it had reached 1.96 TeV in the centre of mass – just shy of its original goal of 2 TeV. Theory also thrived at Fermilab in this period. Lederman had brought James Bjorken to Fermilab’s theoretical physics group in 1980 and a theoretical astrophysics group founded by Rocky Kolb and Michael Turner was added to Fermilab’s research division in 1983 to address research at the intersection of particle physics and cosmology. Lederman also expanded the laboratory’s mission to include science education, offering programmes to local high-school students and teachers, and in 1980 opened the first children’s centre for employees of any DOE facility. He founded the Illinois Mathematics and Science Academy in 1985 and the Chicago Teachers Academy for Mathematics and Science in 1990, and the Lederman Science Education Center on the Fermilab site is named after him. Lederman also reached out to many regions including Latin America and partnered with businesses to support the lab’s research and encourage technology transfer. The latter included Wilson’s early Fermilab initiative of neutron therapy for certain cancers, which later would see Fermilab build the 70–250 MeV proton synchrotron for the Loma Linda Medical Center in California. Scientifically, the target in this period was the top quark. Fermilab and CERN had planned for a decade to detect the elusive top, with Fermilab deploying two large international experimental teams at the Tevatron – CDF (founded by Tollestrup) and DZero (founded by Paul Grannis) – from 1976 to 1995. In 1988 Lederman shared the Nobel prize for the discovery of the muon neutrino at Brookhaven 25 years previously, and in 1989 he stepped down as Fermilab director and joined the faculty of the University of Chicago and later the Illinois Institute of Technology. Lederman was succeeded by John Peoples, a machine builder and Fermilab experimentalist since 1970, and leader of the Fermilab antiproton source from 1981 to 1985. Peoples had his hands full not only with Fermilab and its research programme but also with the Superconducting Super Collider (SSC) laboratory in Texas. In 1993 the SSC was cancelled and Peoples was asked by the DOE to close down the project and its many contracts. The only person to direct two national laboratories at the same time, Peoples successfully managed both tasks and returned to Fermilab to see the discovery of the top quark in 1995. He had also launched the luminosity-enhancing upgrade to the Tevatron, the Main Injector, in 1999. Peoples stepped down as laboratory director that summer and became director of the Sloan Digital Sky Survey (SDSS) – Fermilab’s first astrophysics experiment. He later directed the Dark Energy Survey and in 2010 he retired, continuing to serve as director emeritus of the laboratory. In 1999, experimentalist and former Fermilab user Michael Witherell of the University of California at Santa Barbara became Fermilab’s fourth director. Ongoing fixed-target and colliding-beam experiments continued under Witherell, as did the SDSS and the Pierre Auger cosmic ray experiments, and the neutrino programme with the Main Injector. Mirroring the spirt of US–European competition of the 1960s, this period saw CERN begin construction of the Large Hadron Collider (LHC) to search for the Higgs boson at a lower energy than the cancelled SSC. Accordingly, the luminosity of the Tevatron became a priority, as did discussions about a possible future international linear collider. After launching the Neutrinos at the Main Injector (NuMI) research programme, including sending the underground particle beam off-site to the MINOS detector in Minnesota, Witherell returned to Santa Barbara in 2005 and in 2016 he became director of the Lawrence Berkeley Laboratory. Physicist Piermaria Oddone from Lawrence Berkeley Laboratory became Fermilab’s fifth director in 2005. He pursued the renewal of the Tevatron in order to exploit the intensity frontier and explore new physics with a plan called “Project X”, part of the “Proton Improvement Plan”. Yet the last decade has been a challenging time for Fermilab, with budget cuts, reductions in staff and a redefinition of its mission. The CDF and DZero collaborations continued their search for the Higgs boson, narrowing the region where it could exist, but the more energetic LHC always had the upper hand. In the aftermath of the global economic crisis of 2008, as the LHC approached switch-on, Oddone oversaw the shutdown of the Tevatron in 2011. A Remote Operations Center in Wilson Hall and a special US Observer agreement allowed Fermilab physicists to co-operate with CERN on LHC research and participate in the CMS experiment. The Higgs boson was duly discovered at CERN in 2012 and Oddone retired the following year. Under its sixth director, former Fermilab user and director of TRIUMF laboratory in Vancouver, Nigel Lockyer, Fermilab now looks ahead to shine once more through continued exploration of the intensity frontier and understanding the properties of neutrinos. In the next few years, Fermilab’s Long-Baseline Neutrino Facility (LBNF) will send neutrinos to the underground DUNE experiment 1300 km away in South Dakota, prototype detectors for which are currently being built at CERN. Meanwhile, Fermilab’s Short-Baseline Neutrino programme has just taken delivery of the 760 tonne cryostat for its ICARUS experiment after its recent refurbishment at CERN (see "Search for sterile neutrinos triples up"), while a major experiment called Muon g-2 is about to take its first results. This suite of experiments, with co-operation with CERN and other international labs, puts Fermilab at the leading edge of the intensity frontier and continues Wilson’s dreams of exploration and discovery.
Zhao B.,University of Illinois at Chicago |
Duan V.,Illinois Mathematics and Science Academy |
Yau S.S.-T.,Tsinghua University
Journal of Theoretical Biology | Year: 2011
A novel clustering method is proposed to classify genes or genomes. This method uses a natural representation of genomic data by binary indicator sequences of each nucleotide (adenine (A), cytosine (C), guanine (G), and thymine (T)). Afterwards, the discrete Fourier transform is applied to these indicator sequences to calculate spectra of the nucleotides. Mathematical moments are calculated for each of these spectra to create a multidimensional vector in a Euclidean space for each gene or genome sequence. Thus, each gene or genome sequence is realized as a geometric point in the Euclidean space. Finally, pairwise Euclidean distances between these points (i.e. genome sequences) are calculated to cluster the gene or genome sequences. This method is applied to three sets of data. The first is 34 strains of coronavirus genomic data, the second is 118 of the known strains of Human rhinovirus (HRV), and the third is 30 bacteria genomes. The distance matrices are computed based on the three sets, showing the distances from each point to the others. We used the complete linkage clustering algorithm to build phylogenetic trees to indicate how the distances among these sequence correspond to the evolutionary relationship among these sequences. This genome representation provides a powerful and efficient method to classify genomes and is much faster than the widely acknowledged multiple sequence alignment method. © 2011 Elsevier Ltd.
Mundle S.D.,Janssen Services LLC. |
Mundle S.D.,Illinois Mathematics and Science Academy |
Marathe A.S.,Rush University Medical Center |
Chelladurai M.,Janssen Services LLC.
Critical Reviews in Oncology/Hematology | Year: 2013
A phenomenon of serum tumor biomarker surge or flare that ensues shortly after initiating cancer therapy and that may precede the actual therapeutic response-related decline is poorly understood and remains under-appreciated. However, it may have a significant clinical implication as it could be misinterpreted in clinical practice as therapeutic failure and lead to a premature discontinuation of potentially effective therapy. Therefore, in the present study, attempts have been made to understand the behavior of this phenomenon with respect to a reported median incidence, duration, and its relationship to clinical response. The results of these analyses suggest a significantly lower incidence of this phenomenon with carcinoembryonic antigen (CEA) as determined in colorectal cancer and prostate specific antigen (PSA) in prostate cancer as compared to the other biomarkers studied (p=0.006). Furthermore, regardless of the type of biomarker or the extent of its incidence, a therapy-related initial surge appears to correlate with eventual response to therapy. Although, the biologic significance of this phenomenon is currently elusive, two distinct hypothesis-generating cases with CEA and alpha-fetoprotein (AFP) are presented that, if supported by further research, would provide insights into the role of a biomarker surge in overall tumor growth control by cancer therapy. © 2012 Elsevier Ireland Ltd.
Wu J.,Fermi National Accelerator Laboratory |
Shi Y.,Illinois Mathematics and Science Academy |
Zhu D.,Illinois Mathematics and Science Academy
Journal of Instrumentation | Year: 2012
A low-power time-to-digital convertor (TDC) for an application inside a vacuum has been implemented based on the Wave Union TDC scheme in a low-cost field-programmable gate array (FPGA) device. Bench top tests have shown that a time measurement resolution better than 30 ps (standard deviation of time differences between two channels) is achieved. Special firmware design practices are taken to reduce power consumption. The measurements indicate that with 32 channels fitting in the FPGA device, the power consumption on the FPGA core voltage is approximately 9.3 mW/channel and the total power consumption including both core and I/O banks is less than 27 mW/channel. © 2012 IOP Publishing Ltd and SISSA.
Ramanathan M.,Argonne National Laboratory |
Skudlarek G.,Argonne National Laboratory |
Wang H.H.,Illinois Mathematics and Science Academy |
Darling S.B.,Argonne National Laboratory
Nanotechnology | Year: 2010
Palladium has been extensively studied as a material for hydrogen sensors because of the simplicity of its reversible resistance change when exposed to hydrogen gas. Various palladium films and nanostructures have been used, and different responses have been observed with these diverse morphologies. In some cases, such as with nanowires, the resistance will decrease, whereas in others, such as with thick films, the resistance will increase. Each of these mechanisms has been explored for several palladium structures, but the crossover between them has not been systematically investigated. Here we report on a study aimed at deciphering the nanostructure-property relationships of ultrathin palladium films used as hydrogen gas sensors. The crossover in these films is observed at a thickness of ∼ 5nm. Ramifications for future sensor developments are discussed. © 2010 IOP Publishing Ltd.
Kalinich A.O.,Illinois Mathematics and Science Academy
Information Processing Letters | Year: 2012
Partially-ordered set games, also called poset games, are a class of two-player combinatorial games. The playing field consists of a set of elements, some of which are greater than other elements. Two players take turns removing an element and all elements greater than it, and whoever takes the last element wins. Examples of poset games include Nim and Chomp. We investigate the complexity of computing which player of a poset game has a winning strategy. We give an inductive procedure that modifies poset games to change the nim-value which informally captures the winning strategies in the game. For a generic poset game G, we describe an efficient method for constructing a game ¬G such that the first player has a winning strategy if and only if the second player has a winning strategy on G. This solves the long-standing problem of whether this construction can be done efficiently. This construction also allows us to reduce the class of Boolean formulas to poset games, establishing a lower bound on the complexity of poset games. © 2011 Elsevier B.V. All rights reserved.
Getman R.B.,Northwestern University |
Miller J.H.,Illinois Mathematics and Science Academy |
Wang K.,Illinois Mathematics and Science Academy |
Snurr R.Q.,Northwestern University
Journal of Physical Chemistry C | Year: 2011
Metal-organic frameworks (MOFs) are permanently porous solids, which are promising hydrogen storage materials. However, the maximum H2 adsorption energies in MOFs are only around 10 Kj·mol-1, leading to small adsorption capacities at ambient temperature. In this work we use ab initio calculations and grand canonical Monte Carlo (GCMC) simulations to explore metal alkoxide functionalization for improving H2 storage in IRMOF-1, IRMOF-10, IRMOF-16, UiO-68, and UMCM-150. We examine functionalization with lithium, magnesium, manganese, nickel, and copper alkoxides. We show that lithium and magnesium alkoxides physically bind H2 and manganese, nickel, and copper alkoxides chemically bind H2. H2 binding energies calculated with quantum mechanics are -10, -22, -20, -78, and -84 Kj·mol-1, respectively, for the first hydrogen molecule. Of these, lithium and manganese alkoxides bind H2 too weakly to enhance adsorption at ambient temperature, even at 100 bar. Owing to the strong binding energies, Ni and Cu exhibit high uptake at low pressure, but metal alkoxide sites saturate at pressures as low as 1 bar. They thus exhibit poor deliverable capacities [wt % (100 bar) - wt % (2 bar)]. Magnesium alkoxide exhibits low uptake at low pressure and high uptake at high pressure and is a promising functional group for enhanced ambient-temperature hydrogen storage in all MOFs studied. © 2010 American Chemical Society.
Acosta A.M.,Northwestern University |
Dewald H.A.,Illinois Mathematics and Science Academy |
Dewald J.P.A.,Northwestern University
Journal of Rehabilitation Research and Development | Year: 2011
Robotic systems currently used in upper-limb rehabilitation following stroke rely on some form of visual feedback as part of the intervention program. We evaluated the effect of a video game environment (air hockey) on reaching in stroke with various levels of arm support. We used the Arm Coordination Training 3D system to provide variable arm support and to control the hockey stick. We instructed seven subjects to reach to one of three targets covering the workspace of the impaired arm during the reaching task and to reach as far as possible while playing the video game. The results from this study showed that across subjects, support levels, and targets, the reaching distances achieved with the reaching task were greater than those covered with the video game. This held even after further restricting the mapped workspace of the arm to the area most affected by the flexion synergy (effectively forcing subjects to fight the synergy to reach the hockey puck). The results from this study highlight the importance of designing video games that include specific reaching targets in the workspace compromised by the expression of the flexion synergy. Such video games would also adapt the target location online as a subject's success rate increases.
Anjur S.S.,Illinois Mathematics and Science Academy
American Journal of Physiology - Advances in Physiology Education | Year: 2011
Student test score percentages in the Physiology and Disease (PAD) course at the Illinois Mathematics and Science Academy, a high school for students of the state of Illinois gifted in math and science, were studied over a period of 5 yr. Inquiry-based laboratory experiences in the course were slowly converted during this time from partly student centered and mostly teacher led to completely student centered beginning in fall 2008. Quarterly analysis of the effect of increased inquiry upon average weekly report submissions of 400 students over 4 yr showed a significant improvement in submission (P > 0.0002) between quarters 1 and 2 and also improvement from year to year between the academic years of 2006/2007 and 2009/2010 (P > 0.0001). A comparison of student test score percentages from 346 students in 4 major tests showed a significant increase (P > 0.0125) beginning in the academic year of 2008/2009, when the conversion of all laboratories in the course from partly student centered to completely student centered was concluded compared with scores over the 2 yr from 2006/2007 up to this point. There was also a significant difference (P > 00001) in test score percentages between the individual tests themselves over the 4 yr studied. Taking the study a step further, the 35 students registered in the two PAD classes offered in the fall 2010 semester were divided in each of their classes into student-centered and teacher-centered groups, with the former designing all their experiments and the latter following instructions from the teacher. Student score percentages on specific test questions from the four major tests that focused on transfer of student understanding were compared between these two groups. There was a significant improvement (P > 0.012) when students designed their own laboratories (student-centered group) compared with doing what the teacher asked (teacher-centered group). There was also a significant difference between these student score percentages among the individual tests (P > 0.0001). These data suggest that an increase in student-centered experiments may lead to a corresponding increase in test performance on questions involving student transfer. © 2011 The American Physiological Society.
Lee J.,Illinois Mathematics and Science Academy |
Gupta S.,University of Illinois at Chicago |
Huang J.-S.,University of Illinois at Chicago |
Jayathilaka L.P.,University of Illinois at Chicago |
Lee B.-S.,University of Illinois at Chicago
Analytical Biochemistry | Year: 2013
A strategy using reversed-phase high-performance liquid chromatography (HPLC), thin layer chromatography (TLC), mass spectrometry (MS), nuclear magnetic resonance (NMR), chemical synthesis, and MTT (3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide) cell viability assay to identify allicin as the active anticancer compound in aqueous garlic extract (AGE) is described. Changing the pH of AGE from 7.0 to 5.0 eliminated interfering molecules and enabled a clean HPLC separation of the constituents in AGE. MTT assay of the HPLC fractions identified an active fraction. Further analysis by TLC, MS, and NMR verified the active HPLC fraction as allicin. Chemically synthesized allicin was used to provide further confirmation. The results clearly identify the active compound in AGE as allicin. © 2013 Elsevier Inc. All rights reserved.