Mini-robotelul va fi introdus în stomacul pacientului prin gura, cu ajutorul unui endoscop. Robotelul este dotat cu o penseta, pe care o foloseste pentru a prinde tesuturile canceroase, si cu un cârlig, cu care le va taia si cu care va coagula sângele.
Cu ajutorul unei camere atasate endoscopului, chirurgul va putea urmari tot ce se petrece în stomac pe un monitor, controlând bratele robotelului de la distanta.
"Miscarile pe care le poate efectua un om sunt foarte mari, iar daca doresti sa efectuezi miscari foarte fine, îti va tremura mâna. Cu ajutorul robotilor putem efectua miscari extrem de fine, fara a mai avea problema tremuratului", explica enterologul Lawrence Ho, unul dintre cercetatorii de la Spitalul Universitar National din Singapore care au proiectat robotelul.
Profesorul Ho afirma ca noua inventie a fost deja folosita pe 5 pacienti din India si Hong Kong, eliminând cu succes cancerul la stomac. Operatiile au durat mult mai putin decât cele efectuate fara robotel, nu au lasat cicatrici pe abdomenul pacientilor, prezentând totodata un risc mai mic de infectie.
Cancerul de stomac este foarte raspândit în Asia de Est, fiind una dintre principalele cauze ale deceselor.
Cercetatorii au format o companie în luna octombrie a anului trecut si doresc sa lanseze pe piata robotelul în maxim 3 ani.
The 8,400 panel, 2 megawatt solar array spans the space of six soccer fields, and it was finished in time to start feeding power to the grid before the clock strikes 2012. To prove the solar array’s everyday worth, the airport has installed a real time statistics ticker in the airport lobby so passengers can see how much energy it is creating and how much carbon dioxide is being diverted from the atmosphere.
Construction on the array was completed in just eight weeks — it was started this past October — and was built through a partnership between Düsseldorf International and a subsidiary of the city’s public services, Grünwerke GmbH. “A PV plant of this magnitude within the safety parameters of one of the country’s largest passenger airports reflects a new way of thinking about renewable energies, and we welcome it as another contribution of our city in the service of environment,” said Dirk Elbers, Düsseldorf’s mayor.
The solar array is the largest ground-mounted system located within the security zone of a German Airport but it isn’t the Düsseldorf Airport’s first foray into renewable energy. “Solar energy is not the only source of renewable energy at DUS. We also employ combined heat and power technology in a block heating station, and keep carbon dioxide emissions even lower this way,” noted Christoph Blume, CEO of DUS. The new solar array will create enough power to run 600 four person homes every year.
America şi Eurasia se vor uni la Polul Nord (VIDEO).
„Grandiosul eveniment” geologic se va produce probabil peste 50-200 milioane ani.
Scoarta terestra este într-o continua miscare, dinamica sa fiind puternic influentata de activitatea placilor tectonice. Acest fenomen geologic a dat nastere dorsalei atlantice, pe care s-a format Islanda.
Geologii cred ca, peste milioane de ani, aceste placi tectonice aflate în miscare vor duce în cele din urma la unirea tuturor continentelor.
Fenomenul a creat, în trecutul îndepartat al planetei, mai multe supercontinente precum Nuna, format acum 1, 8 miliarde ani; Rodinia, cu o vechime aproximativa de 1 miliard ani, si cel mai recent, celebrul Pangeea, un supercontinent existent în urma cu 300 milioane ani.
Noul supercontinent al viitorului a fost botezat deja de geologi cu numele de Amasia si se va forma prin contopirea continentului asiatic cu cele americane. Modelul estimativ calculat de geologii americani sustine ca Africa si Australia se vor uni si ele în cele din urma cu Amasia, doar Antarctica ramânând izolata si pe viitor.
Predictia oamenilor de stiinta se bazeaza în principal pe analizarea detaliata a informatiilor legate de de orientarea magnetica a rocilor de pe Terra.
"Rocile vechi s-au format fie prin racirea lavei, fie prin solidificarea straturilor de sedimente. Dupa aceste momente, rocile au ramas într-o orientare magnetica specifica momentulului respectiv, care indica foarte precis latitudinea. Am descoperit astfel ca, dupa ce fiecare supercontinent s-a format, acesta a suferit o serie de rotatii înapoi-înainte, fata de axa stabila a Ecuatorului. Astfel am descoperit ca fiecare supercontinent succesiv, fie el Nuna, Rodinia sau Pangeea, s-a format orientat fiind la 90 de grade fata de predecesorul sau. Studiile ulterioare au demonstrat de asemenea ca supercontinentele s-au format în aceleasi parti ale globului sau în parti alternative ale planetei", declara Ross Mitchell, geolog din cadrul Universitatii Yale.
For NASA researchers, pixels are much more – they are precious data that help us understand where we came from, where we've been, and where we're going.
At NASA's Ames Research Center, Moffett Field, Calif., computer scientists have made a giant leap forward to pull as much information from imperfect static images as possible. With their advancement in image processing algorithms, the legacy data from the Apollo Metric Camera onboard Apollo 15, 16 and 17 can be transformed into an informative and immersive 3D mosaic map of a large and scientifically interesting part of the moon.
Mosaic of the near side of the moon as taken by the Clementine star trackers. The images were taken on March 15, 1994. Credit: NASA
The "Apollo Zone" Digital Image Mosaic (DIM) and Digital Terrain Model (DTM) maps cover about 18 percent of the lunar surface at a resolution of 98 feet (30 meters) per pixel. The maps are the result of three years of work by the Intelligent Robotics Group (IRG) at NASA Ames, and are available to view through the NASA Lunar Mapping and Modeling Portal (LMMP) and Google Moon feature in Google Earth.
"The main challenge of the Apollo Zone project was that we had very old data – scans, not captured in digital format," said Ara Nefian, a senior scientist with the IRG and Carnegie Mellon University-Silicon Valley. "They were taken with the technology we had over 40 years ago with imprecise camera positions, orientations and exposure time by today’s standards."
Left: A normal one-camera image of the lunar surface. Right: A composite Apollo Zone image showing the best details from multiple photographs. Credit: NASA/Google Earth
The researchers overcame the challenge by developing new computer vision algorithms to automatically generate the 2D and 3D maps. Algorithms are sets of computer code that create a procedure for how to handle certain set processes. For example, part of the 2D imaging algorithms align many images taken from various positions with various exposure times into one seamless image mosaic. In the mosaic, areas in shadows, which show up as patches of dark or black pixels are automatically replaced by lighter gray pixels. These show more well-lit detail from other images of the same area to create a more detailed map.
"The key innovation that we made was to create a fully automatic image mosaicking and terrain modeling software system for orbital imagery," said Terry Fong, director of IRG. "We have since released this software in several open-source libraries including Ames Stereo Pipeline, Neo-Geography Toolkit and NASA Vision Workbench."
Lunar imagery of varying coverage and resolution has been released for general use for some time. In 2009, the IRG helped Google develop "Moon in Google Earth", an interactive, 3D atlas of the moon. With "Moon in Google Earth", users can explore a virtual moonscape, including imagery captured by the Apollo, Clementine and Lunar Orbiter missions.
The Apollo Zone project uses imagery recently scanned at NASA's Johnson Space Center in Houston, Texas, by a team from Arizona State University. The source images themselves are large – 20,000 pixels by 20,000 pixels, and the IRG aligned and processed more than 4,000 of them. To process the maps, they used Ames' Pleiades supercomputer.
The initial goal of the project was to build large-scale image mosaics and terrain maps to support future lunar exploration. However, the project's progress will have long-lasting technological impacts on many targets of future exploration.
"The algorithms are very complex, so they don't yet necessarily apply to things like real time robotics, but they are extremely precise and accurate," said Nefian. "It's a robust technological solution to deal with insufficient data, and qualities like this make it superb for future exploration, such as a reconnaissance or mapping mission to a Near Earth Object."
The color on this map represents the terrain elevation in the Apollo Zone mapped area. Credit: NASA/Google Earth
Near Earth Objects, or "NEOs" are comets and asteroids that have been attracted by the gravity of nearby planets into orbits in Earth's neighborhood. NEOs are often small and irregular, which makes their paths hard to predict. With these algorithms, even imperfect imagery of a NEO could be transformed into detailed 3D maps to help researchers better understand the shape of it, and how it might travel while in our neighborhood.
In the future, the team plans to expand the use of their algorithms to include imagery taken at angles, rather than just straight down at the surface. A technique called photoclinometry – or "shape from shading" – allows 3D terrain to be reconstructed from a single 2D image by comparing how surfaces sloping toward the sun appear brighter than areas that slope away from it. Also, the team will study imagery not just as pictures, but as physical models that give information about all the factors affect how the final image is depicted.
"As NASA continues to build technologies that will enable future robotic and human exploration, our researchers are looking for new and clever ways to get more out of the data we capture," said Victoria Friedensen, Joint Robotic Precursor Activities manager of the Human Exploration Operations Mission Directorate at NASA Headquarters. "This technology is going to have great benefit for us as we take the next steps."
Vi ricordate la storia dei neutrini che viaggiano più veloci della luce? L'aveva scoperto l'esperimento Opera, presso i Laboratori nazionali del Gran Sasso dell' Istituto nazionale di fisica nucleare. Be', secondo quanto rivela Science in un articolo pubblicato online, questi risultati sarebbero frutto di un errore. Un errore dovuto a un cavo agganciato male. Con buona pace di Albert Einstein: nulla potrebbe superare in velocità i cari vecchi fotoni. La notizia deve ancora essere confermata ufficialmente, ma il giornalista Edwin Cartlidge avrebbe avuto una soffiata da una fonte vicina all'esperimento.
Quando lo scorso settembre i ricercatori di Opera avevano annunciato lo straordinario risultato, molti scienziati si erano detti scettici e avevano ipotizzato che ci fossero degli errori. Quei 60 nanosecondi di anticipo che i neutrini impiegavano per attraversare la distanza che separa il Cern di Ginevra dai laboratori del Gran Sasso convincevano poco. " Questa discrepanza", scrive Science: " sembra venire da una cattiva connessione tra la fibra ottica che collega il ricevitore Gps usato per correggere il tempo di volo dei neutrini e una scheda in un computer". Il ritardo causato da questo malfunzionamento sarebbe stato sottratto al tempo di volo totale e potrebbe spiegare l'arrivo anticipato.
Einstein allora può dormire sonni tranquilli? Si attende una conferma ufficiale (e nuovi dati per confermare questa ipotesi). Certo sarebbe un bel buco nell'acqua, ma la scienza va avanti anche con gli errori.
Tratamentul se bazeaza pe un compus chimic nou, necunoscut stiintei pâna acum.
În zilele noastre, ciroza ficatului este considerata o boala incurabila. Acum, cercetatorii din Tomsk si Novosibirsk anunta ca noul medicament pe care l-au creat produce efecte miraculoase în rândul pacientilor ce sufera de aceasta afectiune. Oamenii de stiinta lucreaza la crearea acestui tratament de mai bine de 10 ani, iar acum au obtinut primele rezultate. Efectele specifice ale medicamentului au fost confirmate în cadrul experimentelor, iar testele de toxicologie au confirmat ca acesta nu produce efecte secundare, anunta profesorul Gleb Zuzkov.
"Experimentele efectuate pe animale au aratat ca substanta prezinta o înalta eficienta hepa-protectoare atunci când este folosit pentru diferite afectiuni cronice ale ficatului, inclusiv în primele faze ale cirozei. Mai mult, desi este un ferment pe baza de proteine, nu are niciun efect toxic", a declarat Zuzkov.
Cercetatorii au conceput medicamentul folosind anumite tehnici din domeniul nanotehnologiei pentru a facilita regenerarea tesutului ficatului prin stimularea celulelor stem existente în corpul pacientului.
"Medicamentul conceput de noi nu se aseamana cu niciun alt medicament existent sau cu vreunul aflat astazi în faza de concepere. Nicio alta substanta descrisa în literatura stiintifica nu are un asemenea efect pronuntat asupra celulelor progenitor si asupra mecanismelor de reglare a acestora", sustine profesorul Zuzkov.
Medicamentul-minune se afla acum în faza de teste pre-clinice, specialistii estimând ca va fi disponibil publicului în aproximativ 5 ani, dupa încheierea tuturor testelor si formalitatilor legale.
Now a Danish chemist has pioneered a novel way to battle multidrug resistant bacteria. By tweaking a well known psychoactive drug he revitalizes worn-out drugs like sulpha and penicillin.
Chemist Jorn Bolstad Christensen of the University of Copenhagen has just patented the use of schizophrenia medication Thioridazin in boosting the effect of antibiotics. Christensen is an associate professor at the Department of Chemistry, University of Copenhagen, and in the lab he started investigating how the schizophrenia drug might bother bacteria but not humans.
"Thioridazin blocks the capacity of bacteria to cleanse themselves of antibiotics. We knew that before starting. But I wanted to remove the action of the drug in the brain so that mortally ill tuberculosis patients wouldn't have to contend with psychoactive effects as a part of their cure," explains Christensen, who none the less had to come to terms with a much bigger threat as well.
Bacteria such as those responsible for tuberculosis, staphylococcus and enterococcus get rid of antibiotics using their so called efflux-pump. A mechanism which simply pumps the active substance out of the cell before it has an opportunity to do harm. A substance which blocks the pump should ensure that any antibiotic stays inside the bacteria long enough to kill it. There's just one tiny problem. Human cells have efflux pumps as well. And we wouldn't want these blocked.
"The task was to find a substance that will kill bacteria, but not the patients taking the cure. Thioridazin was a good candidate because it's been in use for decades. We could be pretty certain that it wouldn't have any serious side effects," says professor Christensen, who predicts testing the new drug in humans within just a year, as it's already been approved for other medical uses.
Though the risk of blocking the efflux pump of human cells appeared minimal Professor Christensen still needed to minimize the psychoactive effects of the drug. This was where his chemical expertise became indispensable. Chemically Thioridazin consists of two half molecules which are perfect mirror images. One of these mirror- or isomeric forms affects the brain less than the other, so the question was whether bacteria would know the difference.
Doctors and researchers Jette Kristiansen and Oliver Hendricks of Southern University Denmark who are co-holders of the patent have conducted microbiological trials proving that the efflux pump of bacteria stayed blocked regardless of which isomer was used. These results open up a brand new method for combating problems of multidrug resistance.
A research team at the Max Planck Institute of Biophysics in Frankfurt am Main has developed a molecular light switch that makes it possible to control cells more accurately than ever before. The combination switch consists of two different light-sensitive membrane proteins – one for on, the other for off. The method used by the scientists to connect the two components can be used with different protein variants, making it highly versatile.
Optogenetics is a new field of research that aims to control cells using light. To this end, scientists avail of light-sensitive proteins that occur naturally in the cell walls of certain algae and bacteria. They introduce genes with the building instructions for these membrane proteins into the DNA of target cells. Depending on which proteins they use, they can fit cells with on and off switches that react to light of different wavelengths.
For accurate control, it is important that the cell function can be switched off and on equally well. This was exactly the problem until now: when the genes are introduced separately, the cell produces different numbers of copies of each protein and one type ends up dominating.
A group of scientists headed by Ernst Bamberg at the Max Planck Institute of Biophysics has now developed a solution that is both elegant and versatile: they have located the genes for the on and off proteins on the same portion of DNA, along with an additional gene containing the assembly instructions for a connection piece. This interposed protein links the two switch proteins and anchors them firmly in the cell membrane. “In this way, we can ensure that the on and off switches are built into the cell wall side by side, and always in a ratio of 1:1. This allows us to control the cell with great accuracy”, explains Ernst Bamberg.
The combination light switch conceived by the researchers consists of the membrane proteins channelrhodopsin-2 and halorhodopsin. Channelrhodopsin-2 originally comes from the single-celled green alga Chlamydomonas reinhardtii. It reacts to blue light by making the cell wall permeable to positively charged ions. The resulting influx of ions triggers a nerve impulse that activates the cell. Halorhodopsin, isolated by scientists from the bacterium Natromonas pharaonis, has the opposite effect: when the cell is illuminated with orange light, it allows negatively charged ions in, suppressing nerve impulses.
Since channelrhodopsin-2 and halorhodopsin react to light of different wavelengths, together they comprise a useful tool for switching cells on and off at will. The scientists have shown that the method they used to connect the two molecules is also suitable for use with other proteins. “By linking different proteins as required, we will be able to control cells with much greater accuracy in future”, affirms Bamberg.
Colpire le cellule tumorali senza danneggiare i tessuti sani che li circondano. Č questa una delle strategie più promettenti per combattere il cancro, ma raggiungere i bersagli non sempre risulta facile. Infatti, per fare questo lavoro ci vuole un robot ad altissima precisione, come quello sviluppato dall'equipe di ricercatori del Wyss Institute di Harvard. Ma dentro non ci sono nanochip o sensori, perché è un raffinato origami fatto di dna.
Tutti i particolari sono stati pubblicati in uno studio su Science, dove l'equipe coordinata dal biofisico Shawn Douglas spiega i passaggi necessari a costruire l'origami. Il primo passo consiste nell'elaborazione computerizzata della struttura molecolare. Grazie al software Cadnano, i ricercatori sono in grado di progettare e assemblare filamenti di dna affinché assumano forme e conformazioni ben precise.
Nel caso dell'origami di Douglas, la struttura è stata modellata come una tasca di 35 nanometri (milionesimi di millimetro) al cui interno sono immagazzinati dei farmaci antitumorali. In aggiunta, gli scienziati hanno dotato l'origami di due sensori molecolari capaci di riconoscere le cellule cancerose. Come spiega Scientific American, si tratta di due veri e propri inneschi che rispondono alla presenza di tessuti malati aprendo il serbatoio del nanorobot.
In pratica l'origami è in grado di attaccare solo i bersagli che interagiscono con i sensori, mentre risparmia le cellule sane trattenendo al suo interno i farmaci troppo aggressivi. Finora il nanorobot dell'equipe americana è stato messo alla prova solo in laboratorio: Douglas ha testato i filamenti di dna su vari campioni formati sia da cellule umane sane che di natura tumorale. Ebbene, dopo tre giorni di incubazione, il 50% dei bersagli nocivi era stato distrutto senza ripercussioni per quelli innocui.
Ora all'equipe americana non resta che perfezionare l'origami e testarlo in sistemi più complessi. “ Il prossimo passo consiste nel progettare nanorobot a base di dna capaci di resistere all'interno degli organismi viventi”, sostiene Jřrgen Kjems, nanotecnologo della Aarhus University che non ha partecipato all'esperimento. “ Una volta raggiunto questo obiettivo, gli scienziati potranno sviluppare nuove terapie efficaci per animali ed esseri umani”.
Site-ul permite schimbul de informatii care ajuta la socializare si la crearea unor noi prietenii. Cu toate acestea, cerceratorii au descoperit ca, în loc sa creeze noi legaturi, persoanele care au un nivel scazut de respect pentru sine tind sa se plânga prea mult prin intermediul retelelor de socializare si sa devina antipatice.
Oamenii de stiinta de la Universitatea Waterloo au elaborat un studiu pentru a observa felul în care lipsa respectului de sine poate afecta modul în care oamenii îsi exprima sentimentele.
Într-o prima etapa a studiului, voluntarii au fost întrebati ce parere au despre Facebook. Persoanele care se desconsiderau au marturisit ca reteaua de socializare reprezinta un mijloc sigur de a interactiona cu alti oameni si care reduce riscul aparitiei situatiilor incomode.
Apoi, voluntarii au fost rugati sa spuna care au fost ultimele lor statusuri postate pe profilul de Facebook. Pentru a le analiza, specialistii au creat un grup de control format din alti utilizatori ai retelei sociale care au fost pusi sa spuna cât de mult i-ar placea pe oamenii care le-au scris.
Rezultatele au aratat ca cei care se desconsidera sunt mai pesimisti, iar cei din jur îi percep drept antipatici. De asemenea, s-a constatat ca, atunci când cei care au un nivel scazut al stimei de sine posteaza statusuri pozitive, tind sa acumuleze mai multe remarci de la prietenii lor (cei care îi cunosc si în lumea reala) pe Facebook . Pe de alta parte, atunci când persoanele cu o parere buna despre sine posteaza un status pesimist, ei vor primi mai multe raspunsuri de la cunostintele de pe Facebook, din cauza faptului ca remarcile negative sunt, pentru acestia, evenimente rare.
La fel ca multe alte probleme în viata, postarea de comentarii pe Facebook este o actiune ce se poate complica. Desi oamenii care se desconsidera se pot simti în siguranta atunci când "se destainuie" pe Facebook, comentariile nu ajuta întotdeauna la îmbunatatirea perceptiei de sine, pentru ca pe Facebook, spre deosebire de viata reala, atunci când indivizii simt ca ar avea de comentat negativ la adresa cuiva, prefera de multe ori sa se abtina si, astfel, nu ofera celor cu o stima de sine scazuta niciun element util, niciun indiciu care sa arate acestora ca oamenii s-au saturat de negativismul lor.
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