A retina made in a laboratory in Japan could pave the way for treatments for human eye diseases, including some forms of blindness.

Created by coaxing mouse embryonic stem cells into a precise three-dimensional assembly, the 'retina in a dish' is by far and away the most complex biological tissue engineered yet, scientists say.

"There's nothing like it," says Robin Ali, a human molecular geneticist at the Institute of Ophthalmology in London who was not involved in the study. "When I received the manuscript, I was stunned, I really was. I never thought I'd see the day where you have recapitulation of development in a dish."

If the technique, published today in Nature (This article is reproduced with permission from the magazine Nature. The article was first published on April 6, 2011. - TA note), can be adapted to human cells and proved safe for transplantation -- which will take years -- it could offer an unlimited well of tissue to replace damaged retinas. More immediately, the synthetic retinal tissue could help scientists in the study of eye disease and in identifying therapies.

The work may also guide the assembly of other organs and tissues, says Bruce Conklin, a stem-cell biologist at the Gladstone Institute of Cardiovascular Disease in San Francisco, who was not involved in the work. "I think it really reveals a larger discovery that's coming upon all of us: that these cells have instructions that allow them to self-organize."

Cocktail recipe

In hindsight, previous work had suggested that, given the right cues, stem cells could form eye tissue spontaneously, Ali says. A cocktail of genes is enough to induce frog embryos to form form eyes on other parts of their body, and human embryonic stem cells in a Petri dish can be coaxed into making the pigmented cells that support the retina, sheets of cells that resemble lenses and light-sensing retinal cells themselves.

However, the eye structure created by Yoshiki Sasai at the RIKEN Center for Developmental Biology in Kobe and his team is much more complex.

The optic cup is brandy-snifter-shaped organ that has two distinct cell layers. The outer layer -- that nearest to the brain -- is made up of pigmented retinal cells that provide nutrients and support the retina. The inner layer is the retina itself, and contains several types of light-sensitive neuron, ganglion cells that conduct light information to the brain, and supporting glial cells.

To make this organ in a dish, Sasai's team grew mouse embryonic stem cells in a nutrient soup containing proteins that pushed stem cells to transform into retinal cells. The team also added a protein gel to support the cells. "It's a bandage to the tissue. Without that, cells tend to fall apart," Sasai says.

At first, the stem cells formed blobs of early retinal cells. Then, over the next week, the blobs grew and began to form a structure, seen early in eye development, called an optic vesicle. Just as it would in an embryo, the laboratory-made optic vesicle folded in on itself over the next two days to form an optic cup, with its characteristic brandy-snifter shape, double layer and the appropriate cells.

Even though the optic cups look and develop like the real thing, "there may be differences between the synthetic retina and what happens normally," Ali says.

Sasai's team has not yet tested whether the optic cups can sense light or transmit impulses to the mouse brain. "That's what we are now trying," he says. However, previous studies have suggested that embryonic retinas can be transplanted into adult rodents, so Sasai is hopeful.

Sasai, Ali and others expect that human retinas, which develop similarly to those of mice, could eventually be created in the lab. "In terms of regenerative medicine, we have to go beyond mouse cells. We have to make human retinal tissue from human embryonic stem cells and investigation is under way," Sasai says.

The eyes have it

Synthetic human retinas could provide a source of cells to treat conditions such as retinitis pigmentosa, in which the retina's light-sensing cells atrophy, eventually leading to blindness. In 2006, Ali's team found that retinal cells from newborn mice work when transplanted into older mice. Synthetic retinas, he says, "provide a much more attractive, more practical source of cells".

David Gamm, a stem-cell biologist at the University of Wisconsin, Madison, says that transplanting entire layers of eye tissue, rather than individual retinal cells, could help people with widespread retinal damage. But, he adds, diseases such as late-stage glaucoma, in which the wiring between the retina and brain is damaged, will be much tougher to fix.

When and whether such therapies will make it to patients is impossible to predict. However, in the nearer term, synthetic retinas will be useful for unpicking the molecular defects behind eye diseases, and finding treatments for them, Sasai says. Retinas created from reprogrammed stem cells from patients with eye diseases could, for instance, be used to screen drugs or test gene therapies, Ali says.

Robert Lanza, chief scientific officer of the biotechnology company Advanced Cell Technology, based in Santa Monica, California, says the paper has implications far beyond treating and modeling eye diseases. The research shows that embryonic stem cells, given the right physical and chemical surroundings, can spontaneously transform into intricate tissues. "Stem cells are smart," Lanza says. "This is just the tip of the iceberg. Hopefully it's the beginning of an important new phase of stem-cell research."

Source: ScientificAmerican

Con le lenti a contatto non si correggono più solo i difetti della vista o il colore degli occhi, ma si effettuano diagnosi e... si leggono i risultati in realtà aumentata.

Se fissando negli occhi una bella fanciulla (o un bel fanciullo) doveste scorgere circuiti integrati e telecamere non spaventatevi: non state per baciare un cyborg, ma probabilmente qualcuno che indossa le lenti a contatto intelligenti, un dispositivo di nuova concezione a metà strada tra la medicina e i...videogames.
Queste singolari lenti sono infatti dotate di una serie di sensori in grado misurare il livello glicemico e la pressione dell’occhio in pazienti affetti da diabete o glaucoma ma anche di proiettare immagini direttamente sulla retina di chi le indossa creando un vero e proprio display biologico che può essere utilizzato in applicazioni di realtà aumentata.

Lacrime... dolci

L’idea non viene dal set di Star Trek ma da Babak Parviz, un ricercatore della Washington University di Seattle, che già nel 2008 aveva creato il primo prototipo di lente intelligente, o smart lens, installando un microscopico led rosso su un materiale trasparente bio compatibile. Utilizzando la stessa tecnologia ha costruito, qualche anno dopo, la prima lente a contatto in grado di indicare a un diabetico il livello di glicemia. Il dispositivo contiene un minuscolo sensore elettronico e misura in modo continuo e senza bisogno di aghi o prelievi, il livello di glucosio delle lacrime che corrisponde perfettamente a quello del sangue. Una serie di led, impercettibili quando sono spenti, visualizza l’informazione direttamente sull’occhio dell’utilizzatore che in questo modo può dosare in modo più preciso i farmaci per tenere sotto controllo la malattia. Fantascienza? No, realtà.

Occhio alla pressione

Lo scorso settembre Sensimed, uno spin-off dell’Istituto Federale Svizzero per la Tecnologia, ha lanciato la prima versione commerciale di smart lens: serve per tenere sotto controllo il glaucoma, una malattia che provoca un aumento della pressione all’interno del bulbo oculare e che può danneggiare, se non opportunamente curata, il nervo ottico e la vista.
Le super lenti misurano costantemente la curvatura dell’occhio, direttamente correlata con la pressione che c’è al suo interno, e trasmettono l’informazione via radio a un dispositivo portatile indossato dal paziente.
La smart lens è alimentata dal campo elettromagnetico generato da una piccola antenna attaccata con un cerotto al volto del paziente. Funziona insomma come le etichette antifurto dei supermercati che sono alimentate dal campo elettromagnetico delle antenne poste all’uscita. Una volta indossate, chi le porta presenta una qualche somiglianza con Robocop: "una lente colorata potrebbe ovviare al problema" spiegano i ricercatori della Sensimed, "ma in questo momento non è la nostra priorità".

Fonte: Focus.it

De o luna de zile, mi-am facut un obicei in a consuma in fiecare seara cate o rodie. Aproape a devenit o dependenta. Imi place la nebunie gustul acrisor al bobitelor, dar recunosc ca ai nevoie de multa rabdare pentru a savura bob cu bob esenta de rodie. Insa, din punctul meu de vedere, o consumatoare impatimita de fructe, merita sa experimentezi. Atentie! Nu purta haine albe sau pe cele la care tii mult pentru ca gustoasele bobite mai „zboara“ si pot pata. Bineinteles, aceste mici accidente nu pot umbri nici pe departe multitudinea de beneficii pe care le aduce consumul de rodii. Informeaza-te si pune in cosul cu alimente doar pe cele care merita cu adevarat.

Multe vitamine si antioxidanti

Incununata de multe ori cu titluri ca „Super fruct“, „Fructul anului“ sau „Fructul lunii“, rodia are rol de ingredient pentru bauturi, inghetata sau mancaruri in multe tari. O singura rodie pe zi asigura 40% din doza zilnica recomandata de vitamina C pentru adulti, este bogata in acid folic si vitaminele A si E. Acest fruct contine de 3 ori mai multi antioxidanti decat vinul rosu sau ceaiul verde. In mod natural, rodia creste in zone ca Afganistan, Pakistan, Iran, Himalaya, nordul Indiei, dar se cultiva si in zonele mediteraneeana, caucaziana, Asia, Malayezia, Spania, California, Arizona etc. Acest fapt este excelent pentru ca astfel au acces la fructe cat mai multi oameni. Sezonul rodiilor este toamna, in lunile septembrie-noiembrie, deci este anotimpul perfect pentru a face cure cu rodii. Efectele sale? Insiram o pleiada de efecte benefice ale consumului de rodii: are efecte anti-imbatranire, lupta impotriva aparitiei unor maladii ca Alzheimer, cancer, boli de inima, artrite si chiar protejeaza creierul fatului. Este recomandat ca si femeile gravide sa consume suc de rodii deoarece protejeaza creierul micutilor de eventualele afectiuni ce pot aparea din cauza proastei oxigenari sau a circulatiei sangelui necorespunzatoare, a demonstrat un studiu realizat de catre Universitatea de Medicina St. Louis din Washington. Alte proprietati medicale: se foloseste impotriva diareei, reduce febra (in unele cazuri), radacina este folosita pentru combaterea parazitilor intestinali (tenia), dar doar la indicatia medicului. De asemenea, sucul de rodie mai are efecte benefice asupra fertilitatii, in mentinerea tensiunii arteriale la cote normale, lupta impotriva cancerului de prostata, a osteoartritei si a hemoroizilor.

Pro suc de rodie

Specialistii in preventie recomanda sucul proaspat de rodii pentru calitatile sale extraordinare. O echipa de cercetatori americani a prezentat acum 2 ani, cu prilejul unui congres al cardiologilor, un studiu despre sucul de rodii. Cativa pacienti cu boli de inima care luau medicamente pentru reducerea colesterolului au baut timp de 3 luni suc de rodii (150 ml). Iar altii o bautura fara extract de rodii. Primii si-au imbunatatit circulatia sangelui, iar starea celor care au consumat un suc oarecare s-a inrautatit. Cercetatorii au tinut sa precizeze ca sucul de rodii nu este un substitut pentru dieta si exercitii fizice. Datorita nivelului crescut de antioxidanti, nu doar persoanele bolnave pot consuma suc de rodii. S-a observat ca sucul de rodii previne formarea placilor oxidate de colesterol rau (LDL) care duce la artrite si reduce cu 30% formarea acestui tip de placi in cazuri de ateroscleroza (un studiu pe 19 pacienti).

Chiar si in cosmetice...

Celebrul dermatolog Dr. Murad, cunoscut in toata lumea pentru produsele anti-aging, a descoperit ca extractele de rodie fac minuni si pentru piele. Fructul mai contine si acid elagic care este un puternic combatant al radicalilor liberi si are efecte anti-cancerigene, anti-mutagene, anti-virale, anti-carcinogene si ajuta la depigmentarea petelor cauzate de arsuri solare. Astfel au aparut cosmeticele anti-imbatranire si suplimentele alimentare pe baza de rodii. Si marile companii nu s-au oprit aici. Exista si un parfum cu note de rodie (Pomegranate Noir de la Jo Malone).

Un Craciun savuros!

Pentru ca Sarbatorile de iarna ne bat la usa, iar la romani aceste momente sunt sinonime cu multa mancare si multi musafiri este cazul sa-i impresionezi placut. Noi iti propunem un desert usor si sanatos, care e gata rapid. Pana si Mos Craciun va fi incantat sa-l savureze...

Desert cu rodie si zmeura

Ingrediente: 135 g jeleu de zmeura; 60 ml apa fiarta; o lingura de zahar; 480 ml vin rosu dulce; 100 g boabe proaspete de rodie; 100 g zmeura proaspata; frisca (de preferat din smantana); frunze de busuioc.

Mod de preparare: Jeleul se taie bucati si se pune alaturi de zahar si apa intr-un bol la microunde timp de 1 minut.  Se adauga vinul si se mixeaza. Fructele se impart in 4 sau 6 portii si se pun in pahare. Se lasa la frigider 3 ore. Cat timp stau la frigider, acopera gura paharelor cu o folie de aluminiu sau celofan. Inainte de a se servi, se adauga frisca din smantana si se pun frunzulitele de busuioc. Cantitati pentru 4, 6 portii. Timp de preparare: 10’. Pofta buna!

Sursa: csid.ro

Rodia (Punica granatum) este un arbore mic sau arbust foios de înăltime până la 5–8 m. În fapt, termenul de rodie reprezintă fructul, iar planta se numeste rodiu sau rodier.

Frunzele sunt dispuse opus sau altern, sunt lucioase, înguste-alungite, întregi, au 3–7 cm în lungime si 2 cm în lătime. Florile sunt rosii-deschis, 3 cm în diametru, cu patru sau cinci petale (adesea mai multe la plantele cultivate). Fructul are dimensiune mai mare decât portocala si mai mic decât grapefruit-ul, 7–12 cm în diametru cu o formă hexagonală rotunjită, are o coajă rosie groasă si în jur de 600 seminte, prezentând placentatie parietală. Semintele si pulpa ce le înconjoară, numită fruct fals, sunt comestibile. Unele soiuri au pulpa de culoare violet.

Rodierul este o plantă rezistentă la secetă, si poate fi cultivată în regiuni uscate cu climă mediteraneană (cu ierni ploioase) sau în regiuni cu veri ploioase. În regiunile mai umede, rodierii riscă putrezirea rădăcinilor din cauza unor boli datorate unor ciuperci. Sunt plante tolerante la înghet moderat, până la −10 °C.

După desfacerea rodiei prin tăierea cu cutitul, fructele false se separă de coajă si de structurile interne de sustinere. Separarea fructelor false rosii poate fi simplificată prin efectuarea acestei actiuni într-un vas cu apă, unde fructele false se depun pe fund, iar structurile de sustinere plutesc. Întreaga sământă se consumă crudă, desi se doreste doar partea cărnoasă din exteriorul ei. Gustul diferă în functie de soiul de rodie si de nivelul de coacere. Poate fi foarte dulce sau foarte acru, dar în majoritatea cazurilor este undeva la mijloc, care este un gust caracteristic, asezonat cu note de tanin. Rodia bună de mâncat, mai putin taninată, este cea care are coaja usor stearsă, ca si cum ar fi fost frecată de perete, cu urme albe, nu de un rosu puternic. Cele foarte rosii sunt foarte acre, putând fi folosite în salate.

Sucul de rodie este o băutură populară în Orientul Mijlociu, si este folosit si în bucătăriile traditionale iraniană si indiană; în Statele Unite ale Americii a început să fie comercializat pe scară largă în 2002. Concentratul de rodie este folosit si în bucătăria siriană. Siropul de rodii este îngrosat si îndulcit cu suc de rodie; este folosit si în cocktailuri. Înainte de răspândirea rosiilor în Orientul Mijlociu, rodia este folosită în multe mâncăruri persane; poate fi găsită încă în unele retete traditionale cum ar fi fesenjan (un sos gros din nuci si suc de rodie, de regulă servit cu carne de rată sau altă pasăre si orez) si ash-e anar (supă de rodie).

Sursa: wikipedia.org

In an interesting feat of nanoscale engineering, researchers at Lund University in Sweden and the University of New South Wales have made the first nanowire transistor featuring a concentric metal 'wrap-gate' that sits horizontally on a silicon substrate.

Two remarkable aspects of their design are the simplicity of the fabrication and the unique ability to tune the length of the wrap-gate via a single wet-etch step, notes Associate Professor Adam Micolich, an ARC Future Fellow in the Nanoelectronics Group in the UNSW School of Physics.

Packing ever higher densities of transistors into a microchip comes at a hefty price – the reduced overlap between the semiconductor channel through which the current flows and the metal gate makes it harder to switch the current on and off.

This drove the development of the ‘Fin Field-Effect Transistor’, or FinFET, where the silicon either side of the channel is etched away to create a raised mesa structure. This allows the gate to fold down around the sides of the channel, improving the switching without increasing the chip space needed by the device. Even better control can be obtained by wrapping the gate all the way around the channel. But getting metal underneath the channel without compromising the device can be a formidable task using conventional ‘top-down’ silicon microfabrication techniques.

This has led to significant interest in self-assembled nanowires for computing applications (see D.K. Ferry, doi: 10.1126/science.1154446). These tiny semiconductor needles, around 50 nm in diameter and up to several microns in length, are grown using chemical vapour deposition and stand vertically on a semiconductor substrate, making it possible to deposit an insulator and gate metal around the nanowire’s entire outer surface.

Although these coated nanowires can be made into fully-functioning transistors in the vertical orientation, the process to achieve this is very involved. And in many cases, it is more desirable to have the nanowire transistor lying flat on the substrate, as with conventional silicon transistors. This poses an interesting challenge for nanotechnologists: Is it possible to make nanowire transistors with an all-around metal ‘wrap-gate’ that lay flat on a semiconductor substrate?

In work published this week in Nano Letters [Storm et al. doi:10.1021/nl104403g], the team not only demonstrate the first such horizontal wrap-gate nanowire transistors, but they demonstrate that they can be made using a remarkably simple process that allows them to precisely set the wrap-gate’s length using a single wet-etch step, without any need for further lithography.

Their approach exploits the etchant solution’s ability to undercut the resist and etch along the nanowire, producing gates that range in length from slightly less than the contact separation to as low as 100 nm, simply by tuning the etchant concentration. The resulting devices have excellent electrical performance and can be produced reliably with high yield.

Beyond being a significant advance in nanofabrication techniques, these devices open interesting new avenues for fundamental research.

The wrap-gated nanowires are ideal for studies of one-dimensional quantum transport in semiconductors, where remarkable phenomena such as electron crystallization and spin-charge separation may be observed. Additionally, the strong gate-channel coupling combined with an exposed gold wrap-gate surface offers interesting potential for sensing applications by utilising the established chemistry for binding antibodies and other polypeptides to gold surfaces.

Source: PhysOrg

Un ricercatore svizzero è riuscito a mettere in relazione i mutamenti climatici con i cicli di ascesa e declino delle civiltà antiche. È tutto scritto negli alberi. Basta avere abbastanza legno a disposizione. 

La storia delle civiltà antiche non si studia solo sui manoscritti e negli scavi archeologici, ma anche leggendo… gli alberi. Un gruppo di scienziati svizzeri ha analizzato oltre 9.000 manufatti in legno degli ultimi 2.500 anni ed è riuscito a stabilire un collegamento tra l’ascesa e il declino delle popolazioni europee e gli improvvisi mutamenti climatici che hanno caratterizzato le diverse epoche.
I periodi con estati calde e umide hanno coinciso con prosperità e pace, mentre quelli secchi e instabili hanno accompagnato sconvolgimenti politici e guerre. Ma come può tutto questo essere scritto nel legno?

Anelli di storia

Ulf Buntgen, un paleoclimatologo dello Swiss Federal Research Institute for Forest, Snow and Landscape, ha studiato l’influenza del clima sulla crescita degli alberi dell’Europa Centrale negli ultimi due secoli e in particolare la formazione degli anelli di crescita. Ha scoperto che negli anni più floridi, quando acqua e terra sono più ricche di sostanze nutritive, gli alberi crescono con anelli grandi e dai bordi ben definiti. Al contrario, negli anni di siccità, gli anelli sono più stretti e fitti.
I ricercatori hanno poi utilizzato queste informazioni per studiare gli anelli di crescita presenti nei manufatti d’epoca e in alcuni alberi fossilizzati. Hanno potuto così ricostruire in modo molto preciso la cronologia climatica degli ultimi 2500 anni. "Le estati più umide e calde hanno coinciso con i periodi di massimo splendore dell’epoca romana e medievale, mentre la maggior instabilità climatica degli anni tra il 250 e il 600 d.C. ha accompagnato il declino dell’Impero, le sollevazioni popolari e le migrazioni" spiega il ricercatore alla BBC. E in effetti nel III secolo Roma ha dovuto fronteggiare, oltre a un periodo di grande siccità e carestia, le invasioni barbariche e una pesante crisi economica in molte province della Gallia.
Lo studio di Buntgen non si limita ad aprire la strada a un nuovo modo di studiare la storia, ma permette di costruire modelli in grado di spiegare gli effetti delle mutazioni climatiche su società ed economia.

Fonte: Focus.it

A Stanford research team uses glowing nanopillars to give biologists, neurologists and other researchers a deeper, more precise look into living cells.

As words go, evanescent doesn't see enough use. It is an artful term whose beauty belies its true meaning: fleeting or dying out quickly. James Dean was evanescent. The last rays of a sunset are evanescent. All that evanesces, however, is not lost, as a team of Stanford researchers demonstrated in a recent article in Proceedings of the National Academy of Sciences. In fact, in the right hands, evanescence can have a lasting effect.

The Stanford team – led by chemist Bianxiao Cui and engineer Yi Cui (no relation), with scholars Chong Xie and Lindsey Hanson – have created a cellular research platform that uses nanopillars that glow in such a way as to allow biologists, neurologists and other researchers a deeper, more precise look into living cells.

"This novel system of illumination is very precise," said Bianxiao Cui, the study's senior author and assistant professor of chemistry at Stanford. "The nanopillar structures themselves offer many advantages that make this development particularly promising for the study of human cells."

Longstanding challenges

To comprehend the potential of this breakthrough, it is helpful to understand the challenges to earlier forms of molecular imaging, which shine light directly on the subject area rather than using backlighting, as in this approach.

Scientists hoping for better, smaller molecular imaging have for years been handcuffed by a physical limitation on how small an area they could focus on – an area known as the observation volume. The minimum observation volume has long been limited to the wavelength of visible light, about 400 nanometers. Individual molecules, even long proteins common in biology and medicine, are much smaller than 400 nanometers.

This is where evanescence comes in. The Stanford team has successfully employed quartz nanopillars that glow just enough to provide light to see by, but weak enough to punch below the 400-nanometer barrier. The field of light surrounding the glowing nanopillars – known as the "evanescence wave" – dies out within about 150 nanometers of the pillar. Voilà – a light source smaller than the wavelength of light. The Stanford researchers estimate that they have shrunk the observation volume to one-tenth the size of previous methods.
Particular promise

The Stanford nanopillar imaging technique is particularly promising in cellular studies for several reasons. First, it is non-invasive – it does not harm the cell that is being observed, a downfall of some earlier technologies. For instance, a living neuron can be cultured on the platform and observed over long periods of time.

Second, the nanopillars essentially pin the cells in place. This is promising for the study of neurons in particular, which tend to move over time due to the repeated firing and relaxation necessary for study.

Lastly, and perhaps most importantly, the Stanford team found that by modifying the chemistry on the surface of the nanopillars they could attract specific molecules they want to observe. In essence they can handpick molecules to study even within the crowded and complex environment of a human cell.

"We know that proteins and their antibodies attract each other," said Bianxiao Cui. "We coat the pillars with antibodies and the proteins we want to look at are drawn right to the light source – like prima donnas to the limelight."

Setting the scene

To create their nanopillars, the Stanford team members begin with a sheet of quartz, which they spray with fine dots of gold in a scattershot pattern – Jackson Pollock-style. They then etch the quartz using a corrosive gas. The gold dots shield the quartz directly below from the etching process, leaving behind tall, thin pillars of quartz.

A scanning electron microscope image of a cell grown over and interacting with nanopillars. Arrows indicate three nanopillars.

The researchers can control the height of the nanopillars by adjusting the amount of time the etching gas is in contact with the quartz and the diameter of the nanopillars by varying the size of the gold dots. Once the etching process is complete and the pillars are created, they add a layer of platinum to the flat expanse of quartz at the base of the pillars.
The setting is something out of a futuristic John Ford film – Monument Valley rendered in quartz crystal. All that is missing is a stagecoach and John Wayne. In this world, a wide desert of platinum stretches to the horizon, interrupted on occasion by transparent spikes of crystalline quartz that rise several hundred nanometers from the valley floor.

The Stanford researchers then shine a light from below their creation. The opaque platinum blocks most of the light, but a small amount travels up through the nanopillars, which glow against the dark field of platinum.

"The nanopillars look a bit like tiny light sabers," said Yi Cui, associate professor of materials science and engineering at Stanford, "but they provide just the right amount of light to allow scientists to do some pretty amazing stuff – like looking at individual molecules."

The team has created an exceptional platform for culturing and observing human cells. The platinum is biologically inert and the cells grow over and closely adhere to the nanopillars. The glowing spires then meet with fluorescent molecules within the living cell, causing the molecules to glow – providing the researchers just the light they need to peer inside the cells.

"So, not only have we found a way to illuminate volumes one-tenth as small as previous methods – letting us look at smaller and smaller structures – but we can also pick and choose which molecules we want to observe," said Yi Cui. "This could prove just the sort of transformative technology that researchers in biology, neurology, medicine and other areas need to take the next leap forward in their research."

Source: PhysOrg

Mahjong is a game that originated in China, commonly played by four players (with some three-player variations found in Korea and Japan). The four player table version should not be confused with the popular western single player (tile matching) computer game (Mahjong solitaire) which is a recent invention and completely different from the table game. Mahjong is a game of skill, strategy and calculation and involves a certain degree of chance. In Asia, mahjong is also popularly played as a gambling game (though it may just as easily be played recreationally).

The game is played with a set of 136 tiles based on Chinese characters and symbols, although some regional variations use a different number of tiles. In most variations, each player begins by receiving thirteen tiles. In turn players draw and discard tiles until they complete a legal hand using the fourteenth drawn tile to form four groups (melds) and a pair (head). There are fairly standard rules about how a piece is drawn, stolen from another player (melded), the use of basic (numbered tiles) and honours (winds and dragons), the kinds of melds, and the order of dealing and play. However there are many regional variations in the rules; in addition, the scoring system, the minimum hand necessary to win varies significantly based on the local rules being used.