In the news Sugar lights up cancers for magnetic resonance imaging Magnetic resonance imaging (MRI) can de- tect cancers by imaging the consumption of sugar, using a technique developed by sci- entists at University College London (UCL) [1]. Glucose chemical exchange saturation transfer (glucoCEST) is based on tumors Fig. 1. Tumors use large quantities of glucose to sustain their growth. By injecting normal, unlabeled sugar, UCL scientists have detected its accumulation in tumors using magnetic resonance imaging (MRI). (Credit: UCL). Fig. 2. Glucose uptake varies within tumors, as demonstrated using the technique using magnetic resonance imaging (MRI) developed by scientists at UCL. ‘‘Hot’’ regions at the edge of the tumor show increased uptake compared with ‘‘cold’’ central regions. The technique could be used in the future to determine the best therapies to give to individual patients. (Credit: UCL). http://dx.doi.org/10.1016/j.trac.2013.07.004 Trends in Analytical chemistry 50 (2013) iii–viii Contents lists available at SciVerse ScienceDirect Trends in Analytical chemistry journal homepage: www.elsevier.com/locate/trac
Transcript
Trends in Analytical chemistry 50 (2013) iii–viii
Contents lists available at SciVerse ScienceDirect
Trends in Analytical chemistry
journal homepage: www.elsevier .com/locate / t rac
In the news
Sugar lights up cancers for magnetic resonance imaging
Magnetic resonance imaging (MRI) can de-tect cancers by imaging the consumption of
Fig. 1. Tumors use large quantities of glucose to sustain thmagnetic resonance imaging (MRI). (Credit: UCL).
Fig. 2. Glucose uptake varies within tumors, as demonstrathe edge of the tumor show increased uptake compared windividual patients. (Credit: UCL).
http://dx.doi.org/10.1016/j.trac.2013.07.004
sugar, using a technique developed by sci-entists at University College London (UCL) [1].
eir growth. By injecting normal, unlabeled sugar, UCL scie
ted using the technique using magnetic resonance imagingith ‘‘cold’’ central regions. The technique could be used in
Glucose chemical exchange saturationtransfer (glucoCEST) is based on tumors
ntists have detected its accumulation in tumors using
(MRI) developed by scientists at UCL. ‘‘Hot’’ regions atthe future to determine the best therapies to give to
6. Nanoporous anodic aluminumoxide for chemical sensing andbiosensorsby A. Santos, T. Kumeria and D. LosicTrends Anal. Chem. 44 (2013) 25.
consuming much more glucose than nor-mal, healthy tissues in order to sustain theirgrowth. The researchers found that sensi-tizing an MRI scanner to glucose uptakecaused tumors to appear as bright imageson MRI scans of mice. Trials are now underway to detect glucose in human cancers.
‘‘GlucoCEST uses radio waves to mag-netically label glucose in the body,’’ saidlead researcher Simon Walker-Samuel, UCLCentre for Advanced Biomedical Imaging(CABI). ‘‘This can then be detected in tumorsusing conventional MRI techniques. Themethod uses an injection of normal sugarand could offer a cheap, safe alternative toexisting methods for detecting tumors,which require the injection of radioactivematerial.’’
‘‘In the future, patients could potentiallybe scanned in local hospitals, rather thanbeing referred to specialist medical centers,’’said Professor Mark Lythgoe, Director of CABIand one of the authors of the study.
‘‘Our cross-disciplinary research could al-low vulnerable patient groups, such as preg-nant women and young children, to be scannedmore regularly, without the risks associatedwith a dose of radiation,’’ said Professor XavierGolay, another author of the study:
‘‘We have developed a new state-of-the-art imaging technique to visualize and tomap the location of tumors that will hope-
Fig. 3. Staphylococcus aureus bacteria (P
fully enable us to assess the efficacy of novelcancer therapies,’’ added Walker-Samuel.
Contact:Simon Walker-SamuelCentre for Advanced Biomedical ImagingUniversity College London, UKE-mail: simon.walkersamuel@ucl. ac.uk
Reference[1] S. Walker-Samuel et al., Nature Med. (2013) (DOI:
10.1038/nm.3252).
FTIR follows bacterial infection
Using infrared light and artificial in-telligence, a method can predict diseaseprogression following Staphylococcus aureusinfection, according to scientists from theUniversity of Veterinary Medicine, Vienna(Vetmeduni Vienna).
The researchers developed a techniquefor rapid, reliable distinction betweenstrains that can cause chronic infections andthose that cannot.
S. aureus is common in nature and fre-quently colonizes the skin and the upperrespiratory tract of humans. A healthy im-mune system can fight the microorganism,but, once the immune system is weakened,the pathogen can spread and lead to life-threatening diseases of the lungs, the heartand other organs. S. aureus also produces
hoto: Grunert/Vetmeduni Vienna).
7. Analytical and bioanalytical appli-cations of carbon dotsby J.C.G. Esteves da Silva and H.M.R.GoncalvesTrends Anal. Chem. 30 (2011) 1327.
8. Novel applications of molecularly-imprinted polymers in samplepreparationby Y. Hu, J. Pan, K. Zhang, H. Lian andG. LiTrends Anal. Chem. 43 (2013) 37.
9. Analysis of emerging contaminantsin foodby M.I. Farré and D. BarcelóTrends Anal. Chem. 43 (2013) 240.
10. Trends in quality in the analyticallaboratory II. Analytical methodvalidation and quality assuranceby I. Taverniers, M. De Loose and E.Van BockstaeleTrends Anal. Chem. 23 (2004) 240.
*January to March 2013, extractedfrom SciVerse Scopus, 18 July 2013
toxins in foods and can cause serious foodpoisoning. In cattle, S. aureus frequentlycauses inflammation of the udders, so it isalso of great interest in veterinary medicine.
S. aureus comes in many different forms,which help it evade the immune system.Aggressive types of S. aureus form capsulesand multiply rapidly but are also quickly
Fig. 4. BZP crystals under a light microscope.
In the news / Trends in Analytical chemistry 50 (2013) iii–viii v
recognized by the immune system. Capsule-free forms are better able to survive withincells and are less well recognized by theimmune system. In other words, they ‘‘hideand seek’’ before they attack, so they aremore likely to cause chronic infections thatare harder to treat. Recent studies suggestthat, in the course of adapting to its host(human or animal), S. aureus undergoes aform of microevolution, during which it lo-ses its capsule. The capsule-free formevades the host immune system and caneven survive antibiotic treatment.
S. aureus was previously detected byspecific antibodies that are not commer-cially available and have to be produced inanimal experiments. Tom Grunert and col-leagues at Vetmeduni developed a methodby which the capsules can quickly andclearly be distinguished from one anotherwithout using antibodies. The techniquerelies on Fourier transform infrared spec-troscopy (FTIR). IR light is shone on themicroorganisms to be tested and the re-sulting spectral data are input into a su-pervised self-learning system – an artificialneuronal network (ANN), which uses thedata to work out the type of capsule.
‘‘With the new method we can routinelytest patient samples with a success rate ofup to 99%,’’ said Grunert.
‘‘In principle, germs have two choiceswhen they infect a host: attack or hide – intechnical terms virulence or persistence,’’explained Monika Ehling-Schulz, head ofGrunert’s institute. ‘‘If they attack, they riskdestroying the host and consequentlythemselves, whereas, if they hide, they maybe outcompeted by others.
‘‘A detailed knowledge of the mechan-isms of virulence and persistence and theway bacteria switch between them will helpus to develop novel and more effectivetherapies,’’ she said.
Contact:Professor Monika Ehling-SchulzUnit of Functional MicrobiologyUniversity of Veterinary MedicineVienna, AustriaTel.: +43 664 60257-6397E-mail: monika.ehling-schulz@vet medu-ni.ac.at
Reference[1] T. Grunert, M. Wenning, M.S. Barbagelata, M.
Fricker, D.O. Sordellii, F.R. Buzzola, M. Ehling-Schulz, J. Clin. Microbiol. 51 (2013) 2261.
Microcrystalline test for ‘legal highs’
A method to detect ‘‘legal highs’’ is in-corporated in a United Nations (UN) manualfor use by drug-analysis laboratories allover the world [1], following developmentat the University of Lincoln, UK.
The recent World Drug Report from theUN Office on Drugs and Crime (UNODC) saidnew synthetic substances are constantlybeing spread via the Internet. The UK is thelargest market for legal highs in the Eur-opean Union, and, with new substancesconstantly being identified, governmentsacross the world are struggling to keep ontop of regulation.
A research group from the School of LifeSciences at Lincoln is at the forefront of re-search in this area, having developedmethods for quick, conclusive analysis oflegal highs. They have also published anumber of papers that have made an impactin the field.
The method in the UNODC manual de-scribes a microcrystalline test for the ana-lysis of benzylpiperazine (BZP), a moderndesigner drug often used as a substitute for‘‘ecstasy’’. Microcrystalline tests are quick,simple chemical tests that require only asmall amount of sample and a microscopeto observe the resulting crystals. The test isa simple reaction, whereby small crystalsare formed between a drug sample and areagent, specifically chosen to react withthe suspected drug.
The microcrystalline test was used suc-cessfully for decades to aid analysis ofseized samples of suspected drugs of abuse,but it was abandoned in favor of more so-phisticated analyticalinstruments. However, at the University ofLincoln, Leonie Elie investigated micro-crystalline testing to improve the techniqueand modernize it. The research group pub-lished microcrystalline tests for three rela-tively new substances and legal highs,including mephedrone, MDAI and BZP.
‘‘In microcrystalline testing you compareshapes of crystals obtained from unknownsubstances to those developed with knownstandards,’’ said Elie. ‘‘Forensic scientistshave been using this technique with con-fidence for many decades but the knowl-edge is lost when it doesn’t get passed on tothe newer generations.
‘‘Unfortunately, nowadays most drug-ana-lysis labs seem to prefer using instrumentaltechniques rather than relying on empiricalmethods, like microcrystalline testing.’’
‘‘With our modernizing approach, wecan continue to show how reliable thisseemingly simple method is,’’ she said.
‘‘One of the problems with this work isthat, by their very nature, doing anythingwith the very small crystals is a real chal-lenge,’’ said Mark Baron of the University ofLincoln. ‘‘You can only see them through amicroscope and have little specific data,other than, when there is a drug present,you can see unique crystals forming to in-dicate that particular drug.’’
Contact:Leonie ElieSchool of Life SciencesUniversity of Lincoln, UKTel.: +44 01522 88 6855E-mail: [email protected]
Reference[1] United Nations Office for Drugs and Crime,
Recommended Methods for the Identificationand Analysis of Piperazines in Seized Materials,United Nations, New York, USA, 2013, p. 17.
Mercury levels set to increase
Future increases in ocean mercury levels arelikely to be greater than anticipated, ac-
Fig. 5. Speed at which a drop of mercury released into the atmosphere (top row), soil (middle), or ocean (bottom)finds its way to the soil (green), ocean (blue), or atmosphere (yellow), over time (left to right). It can takehundreds of years for the mercury to be locked away in the deep ocean or minerals. (Image courtesy of HelenAmos, Harvard University).
vi In the news / Trends in Analytical chemistry 50 (2013) iii–viii
cording to environmental researchers atHarvard University, USA, who publishedevidence that significant reductions inmercury emissions will be necessary just tostabilize current levels of the toxic elementin the environment [1].
So much mercury persists in surface re-servoirs (soil, air, and water) from pastpollution, going back thousands of years,that it will continue to persist in the oceanand accumulate in fish for decades to cen-turies, they report.
‘‘It’s easier said than done, but we’readvocating for aggressive reductions, andsooner rather than later,’’ says Helen Amos,lead author of the study.
The Atmospheric Chemistry ModelingGroup at the Harvard School of Engineeringand Applied Sciences (SEAS) has been col-lecting historical data on mercury emissionsas far back as 2000 BC and building newenvironmental models of mercury cyclingthat capture the interactions between at-mosphere, oceans and land.
Their model reveals that most of themercury emitted to the environment endsup in the ocean within a few decades andremains there for centuries to millennia.
These days, emissions are mainly from coal-fired power plants and gold mining. Throwninto the air, rained down onto lakes, ab-sorbed into the soil, or carried by rivers,mercury eventually finds its way to the sea.In aquatic ecosystems, microbes convert itto methylmercury, the organic compoundthat accumulates in fish, finds its way to ourdinner plates, and has been associated withneurological and cardiovascular damage.
It is generally assumed that mercurypollution began with the Industrial Revolu-tion. However, humans have been releasingmercury into the environment for thou-sands of years. Past research has found itstored in peat in Europe and in layers ofsediment at the bottoms of lakes in SouthAmerica. The ancient Greeks and Chineseused mercury as a pigment; pots of quick-silver have been found in tombs dating toabout 2000 BC; and the Assyrians arethought to have used both quicksilver andcinnabar (the bright red ore in which mer-cury naturally occurs) as early as 1900 BC.In 1570 AD, Spanish colonists in Central andSouth America were using mercury to ex-tract silver; and, 300 years later, mercuryagain featured in the California gold rush.
The environment naturally releases andcycles a certain amount of mercury, blastingit out of rock with each volcanic eruption,but the new model developed at Harvarddemonstrates that humans have been, andcontinue to be, responsible for the majorityof the mercury currently found in theatmosphere, the soil and oceans.
The new model quantifies the impact ofhistorical emissions deduced from archae-ological and anthropological research intoartisanal and industrial techniques, and, forthe first time, couples seven different en-vironmental systems into one coherentmodel.
‘‘This model is built on the best availablescience, and what it’s showing us is that, ifwe want to reduce the amount of mercuryin the environment, it’s not enough simplyto stabilize the amount that we’re emit-ting,’’ said Amos. ‘‘We would need to reduceit dramatically.’’
Specific findings include the following:� anthropogenic emissions have increased
the amount of mercury in the atmo-sphere, surface ocean, and deep ocean byfactors of 7.5, 5.9, and 2.1, respectively,compared to natural conditions;� 60% of the mercury currently being de-
posited in the atmosphere comes fromlegacy mercury, released by humans inthe past, which continues to cyclethroughout the environment. Only 13%of current mercury deposition is naturalin origin. The remaining 27% comes fromanthropogenic emissions; and,� at least half of the current anthropogenic
mercury content of the surface oceanoriginated before 1950.
Contact:Helen AmosDepartment of Earth and Planetary SciencesHarvard UniversityCambridge, MA, USAE-mail: [email protected]
Global Biogeochem. Cycles (2013) (DOI: 10.1002/gbc.20040).
Monitoring improves the River Danube
Monitoring is in place to activate an alertsystem when the concentrations of pollu-tants in the River Danube exceed thethreshold set by the European Union (EU)Water Framework Directive, which enteredinto force in 2000.
There are 19 countries in the catchmentarea of the River Danube. A lot of inadequatelytreated wastewater used to find its way to theRiver Danube, so putting at risk the drinkingwater supply for millions of people. It also led
Fig. 6. River Danube (Image credits: elebe Español, Austria).
Fig. 7. The encephalin receptor (grey) threads through the cell membrane. The structure of the free encephalinin the complex with the rhodium atom (orange) is highlighted in green. (�Florian Wieberneit, BiomolecularNMR).
In the news / Trends in Analytical chemistry 50 (2013) iii–viii vii
to problems for irrigation, industry, fishing andtourism.
In 2009, scientists introduced a compu-terized tool for the national water autho-rities, as an outcome of an EU-fundedproject, called SOCOPSE.
‘‘The tool was designed for the en-vironmental management of not only of theRiver Danube, but also all the rivers inEurope,’’ said Jaroslav Slobodnik, co-ordinator of the River Danube case study. ‘‘Itprovides a set of recommendations for wa-ter managers on how to remove pollution,alongside an estimate of the associated costand a time horizon.’’
The project tool sets the basis of the RiverBasin Management Plan, designed to ensurethat all waters of the basin reach goodquality by 2015. It also helps authoritiescontrol the most prevalent polluting sub-stances. The main pollutants monitored inthe River Danube under the project in-cluded heavy metals, such as cadmium andmercury, DEHP plasticizer, detergents con-taining nonylphenols and disinfectantsmade of tributyltin compounds.
‘‘Since the Water Framework Directiveentered into force, we can have a kind of aprofile of the River Danube every six years,’’said Slobodnik. ‘‘We go by ship from Ger-many to the Black Sea, collecting the watersamples and analyzing them for all possibleparameters.’’
The first survey was done in 2001, thesecond in 2007. The third large scale riversurvey was due to be done last month(September 2013).
‘‘In 2007, we already concluded that thequality of the water of the River Danubewas generally improved. And I hope thatthis trend has been maintained,’’ he said.
Some experts believe that the improvementin the quality of the water of the River Da-nube is due mainly to the economic down-turn.
‘‘In the lower River Danube and its maintributaries, there is now less heavy metalpollution, fewer emissions from petro-chemical industry and lower loads of or-ganic pollution and nutrients fromagriculture,’’ stated engineer Liviu Popescu,member of the Regional Council of GlobalWater Partnership for Central and Eastern
European Region, a non-governmental or-ganization based in Stockholm, Sweden.
‘‘In the upper River Danube, the heavyrainfall in the past two years led to dilutionof the concentrations of the chemicalwaste,’’ he told youris.com.
To maintain the sustainability of theRiver Danube, he suggested more efficientuse of pesticides in agriculture and invest-ment to upgrade wastewater-treatmentplants (WWTPs) or to build new ones, asrequired.
It was possible to identify the structure ofan encephalin in solution and to track itsinteraction with an opioid receptor in detailto provide a new, precise starting point forthe development of drugs meant to combatspecific types of pain, following research byan interdisciplinary team of biochemistsand inorganic chemists at Ruhr-UniversitätBochum (RUB), Germany [1].
Encephalin is a peptide, made up ofamino acids. Because it is very flexible insolution, researchers find it difficult to‘‘grasp’’ it for structural analysis. RUB che-mists deployed the trick of introducing acomplex into the encephalin. Subsequently,they analyzed the structure of the metal-peptide complex by means of nuclear
viii In the news / Trends in Analytical chemistry 50 (2013) iii–viii
magnetic resonance (NMR). With boundrhodium, it was possible to study the en-cephalin much more extensively than everbefore. Using computer simulation, the re-searchers then calculated how to optimizeintegration of the specific structure of theencephalin, as identified by NMR spectro-scopy, into the established three-dimen-sional structure of the receptor.
‘‘All of a sudden – some 40 years after en-cephalins were discovered – we begin to un-derstand on a nuclear level how thesemessengers bind to their receptors,’’ saidProfessor Nils Metzler-Nolte. ‘‘Our researchshows that, by deploying metal complexes thatdo not occur in nature, we help to solve ques-tions in the field of medicine that have longremained unanswered,’’ adds Professor Ra-phael Stoll.
The research was supported by the Ger-man Research Foundation (DFG). It has itsroots in the collaboration between theteams of Prof. Nolte and Prof. Stoll andProfessor Richard H. Fish of the LawrenceBerkeley National Laboratory in California,USA. Last year, the team demonstrated forthe first time how metal complexes can bedeployed in structural analysis.
Contact:Prof. Dr. Nils Metzler-NolteRuhr-Universität BochumGermanyTel.: +49 (0)234 32 24153E-mail: [email protected]
Reference[1] F. Wieberneit, A. Korste, B. Albada, N. Metzler-
Nolte, R. Stoll, Dalton Trans. 42 (2013) 9799.
Fig. 8. (A) In this W-INK prototype, the chip appears blankethanol, however, it reveals new markings. (B) Because allpotential to be used to differentiate between liquids of an
W-INK wins R&D 100 Award
A device that can instantly identify un-known liquids based on their surface ten-sion was selected to receive a 2013 R&D 100Award from R&D Magazine.
Invented in 2011 by materials scientistsand applied physicists at the Harvard Schoolof Engineering and Applied Sciences (SEAS)and the Wyss Institute for Biologically In-spired Engineering at Harvard, Cambridge,MA, USA, the Watermark Ink (W-INK) de-vice offers a cheap, fast, and portable way toperform quality-control tests and detect li-quid contaminants.
W-INK fits in the palm of a hand andrequires no power source. It exploits thechemical and optical properties of preciselynanostructured materials to distinguish li-quids by their surface tension.
‘‘Visual colorimetric indicators, suchas pH paper or pregnancy tests, have en-joyed wide commercial success becausethey are inexpensive and exceptionally easyto use,’’ said Professor Joanna Aizenberg.‘‘Our W-INK technology greatly expandsupon this concept because it can detect anyliquids through cleverly-designed, chemi-cally-encoded opals that reveal easy-to-recognize, macroscopically-distinct struc-tural color patterns upon liquid wicking.’’
Prof. Aizenberg envisions a broad rangeof industrial and consumer applications –for example:� detecting toxins in a chemical spill;� testing alcohol levels or the quality of
gasoline, sugar or caffeine; or,� the creation of simple teaching sets and
toys.The project was a collaboration between
Prof. Aizenberg and Professor Marko Lonar.
in the air. When dipped in varying concentrations ofliquids exhibit a surface tension, this indicator has they type. (Image courtesy of Ian Burgess).
This is the second year running that Ai-zenberg’s team has won an R&D 100 Award.In 2012, her research group was recognizedfor their invention of an extremely low-friction material, called SLIPS, for ‘‘slippery,liquid-infused porous surfaces.’’ Inspired bythe pitcher plant, SLIPS resists liquid, ice,and dirt and could be incorporated into awide range of products, from medical de-vices to refrigerators.
‘‘These R&D 100 Awards are a testamentto the role of bold scientific thinking andapplied research in solving everyday chal-lenges – in the case of W-INK, improvingquality control and security,’’ said ProfessorCherry A. Murray, Dean of Harvard SEAS.‘‘The W-INK technology draws on insightsfrom chemistry, materials science, optics,self-assembly, and nanotechnology tocreate a deceptively simple chip with thepotential to make a really big impact.’’
The W-INK concept relies on a preciselyfabricated material called an inverse opal, alayered glass structure with an internalnetwork of ordered, interconnected airpores. The W-INK device changes colorwhen it encounters a liquid with a parti-cular surface tension. A single chip can reactdifferently to a wide range of substances. Itis also sensitive enough to distinguish be-tween two very closely related liquids.
‘‘It is fantastic to see Joanna and herteam acknowledged yet again for theirmastery of bioinspired design,’’ said WyssFounding Director Donald Ingber, who isalso a Professor of Bioengineering at Har-vard SEAS. ‘‘The iridescent light effects ofinverse opals are found throughout nature,from butterfly wings to oyster shells – andW-INK harnesses these design principles inan entirely new, innovative way with im-mediate relevance to society.’’
Winners of the R&D 100 Awards will berecognized at a ceremony next month (No-vember 2013).
Contact:Professor Joanna AizenbergHarvard School of Engineering and AppliedSciences (SEAS)Cambridge, MA, USATel.: +1 (617) 495-3558E-mail: [email protected]
Reference[1] Ian B. Burgess et al., Proc. SPIE 8632 (2tsaven
