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Search Result for: study Technology and Health News
The particles of cobalt-chromium can cause DNA damage even if they do not come physically into contact with the cells.
The nano-particles manage to damage the DNA of cells protected by a barrier made up of cellular membranes, without physically entering into contact with the cell, but rather through a multitude of chemical signals.
This was found in a study coordinated at the Bristol Implant Research Center, proving that it brings out a new risk associated with nanotechnology, but also the opportunity to exploit this behavior in an innovative way.
Nano-particles are now widely used. In surgery, for example, are an integral part of prostheses and implants. The research conducted so far on the risks of nanoparticles, however, relates mainly to the effects of direct exposure, while very little is known about what can cause the indirect exposure. In the new study, researchers have wondered if a barrier device was able to protect cells from the effects of nano-particles consisting of chromium and cobalt in the tissues of the clothes and orthopedic implants. The researchers interposed a barrier between nanoparticles formed out of multilayer chromium-cobalt (in quantities thousands of times greater than those with whom we come in contact normally) and a culture of human fibroblasts (connective tissue cells).
Although nano-particles have not managed to cross the membrane, the fibroblasts had DNA mutations which were ten times more than the control fibroblasts. According to scholars, the effect is due to chemical signals between the cell membrane and fibroblasts. If the lines of communication between them are broken, the rate of DNA damage returned to normal.
This study researched killing cancer cells with nano-magnets, with the same principle as a microwave oven.
The study of nano-particles applied to biomedicine continues to give interesting results, as research is still in its infancy. Through their work, the chemists from the university of Cagliari are now investigating some of the possibilities opened by this field. One is to use magnetic particles to convey the drugs only to the diseased cells, the other is to drive up the tumor and then force them to oscillate under the control of a variable magnetic field, thereby heating the target cells, just like a microwave oven does with the water molecules contained in food.
This second mechanism exploits hyperthermia. It appears that cancer cells can be destroyed by beeing brought to a temperature of 42.5 degrees Celsius for about half an hour.
In order arrive at the place desired, the particles must be incorporated into liposomes, hollow microspheres formed by lipid bilayers (for which reason they are called "magneto-liposomes"), which are able to overcome the barrier of cells. They must have a diameter of about 20 nanometers. Larger could indeed block blood vessels, while smaller particles may be "eaten" by macrophage cells which are in charge with the elimination of foreign bodies.
Currently, the research team is working on the synthesis of particles and study of their structural and magnetic properties. Currently these are being built in oxide of iron or iron cobalt. The latter are more manoeuvrable, because their magnetic properties depend strongly on the direction along which the field is applied to (property known as magnetic anisotropy).
Can we act on stopping the process of infection, without the risk to develop strains resistant to antibiotics ?
Small molecules that interrupt the chemical signals by which bacteria communicates by blocking the process of infection have been identified. The discovery, published in Molecular Cell, as well as representing a new option in the treatment of infections, reduces the risk of growth of bacteria strains resistant to antibiotics.
Bacteria will exchange information with a system of intercellular communication, called quorum sensing, which allows them to perceive and respond to changes in density and to coordinate actions of the group. As soon as the conditions are favorable to population growth, for example if they are within a host, the bacteria sends chemical signals to molecules that bind to receptors inside: LuxR-type proteins or proteins of the type LuxN, located on membrane of each cell. In this way the infection proceeds without hitches. "
Blocking the communications of the enemy has always been a winning weapon. The researchers searched the key to succeeding, and found in an old acquaintance. In a previous study Bassler and colleagues had discovered that a class of molecules called lactose acilomoserina (AHL), is able to compete with the signals acting on LuxN proteins, preventing them from binding to the receptor. In the recent study, researchers have realized that the AHL can also bind to proteins of the LuxR type.
In this way was brought into light the AHL the ability to bind to both receptors, although the two proteins have two completely different structure and location mechanisms.
Cancer threatens the conservation of some wild species because it represents one of the top causes of death. This was also recently featured on the Discovery Channel.
Cancer affects some animals with the same effect as in human beings, and could be the cause of extinction of some wild species. The researchers say the Society of Preservation of Fauna and Flora of New York have found an increase in cancer cases in wild animals in recent years.
According to their findings, published in Nature Reviews Cancer, the species most affected are those at risk of extinction, like the Tasmanian devil, a small marsupial carnivore, already decimated in the late nineties by a rare form of transmissible cancer (the devil facial tumor).
The cause is unknown, but it has been shown that malignant cells are able to spread among the samples and through bites during fights. To save the species, biologists are now isolating infected animals in zoos or reserves.
Denise McAloose and Alisa Newton, authors of the study, have investigated the possible causes of cancer in different species, and have found a correlation between cancer and pollution. For example, for the living beluga in the estuary of the St. Lawrence River (Canada), a form of bowel cancer is the second leading cause of death. The culprit could be an organic compound (a polycyclic aromatic hydrocarbon that is found in oil, but also in municipal waste), already known to be carcinogenic for our species.
Small robots that walk on water like insects? The kitchen table, the walls of a room or the arms of an armchair that are self-cleaning? Two phenomena that Xiao Cheng Zeng, a professor of chemistry at University of Nebraska in Lincoln (USA), considers possible in the near future, and based on the same characteristic: super hidrofobia.
Thanks to the computational performance of the super computer of the Riken Institute in Japan, the researcher is able to reproduce the conditions that give the area the property is to "roll" away the drops of water.
In nature this phenomenon is observed on the bristles of caterpillars or on lotus flowers, and allows insects that often are seen on ponds slip skate on water. As the authors of the study reported the caterpillars or insects skaters get the super hydrophobia surface through a "two-tier" surface which means a waxy base on which there are microscopic structures like hair, often covered in turn by smaller "hair".
These gradients decrease the surface area in contact with the drop of water. The result is that the drop rolls instead of sliding, as it would be a hydrophobic surface.
Twenty years after the first partially successful attempt to cold fusion, a new experiment seems to have reopened the hopes of obtaining nuclear reactions at low energy (LENR low-energy nuclear reactions).
This was announced by a team of researchers led by Pamela Mosier-Boss of the Space and Naval Warfare Systems Center San Diego (California), with a study presented at the annual meeting of American Chemical Society, the first visible evidence of the production of neutrons, the particles subatomic whose presence demonstrates the atomic reaction occurred.
It was 1989 when Martin Fleischmann and Stanley Pons showed that it has obtained experimentally the Cold Fusion, arousing great outcry in the scientific community. Fusion is the reaction that takes place inside of stars, their source of energy, able to reproduce in the laboratory at room temperature this process would be an amazing achievement.
Further research then disappointed initial expectations: the rare attempts (for example, those of 2000 and 2002) to reproduce the results of 1989 and have not convinced the path of nuclear reaction at low energy has not proved viable as an alternative to "clean" nuclear fission, which is based on the common operation of nuclear power.
The use of an organic material has been put in place a structure capable of transmitting data at rates eight times higher than those of traditional devices .
The study of materials capable of transmitting data at ever higher speeds is the constant challenge of the technology of optical communications. The use of a new organic material, tested by a team of U.S. and European research coordinated by Ivan Biaggi of Lehigh University (United States), has enabled to achieve data transfers much higher than that obtained so far with traditional devices.
The novelty lies in the combination of structures in silicon with organic material, identified by the initials Ddmebt . This is essentially a kind of "nonlinear" device, able to change its molecular structure to the passage of light, making it propagate at high speed. To minimize interference with the passage of data, researchers have vaporized the organic material and the deposit left on the rails of silicon and in the spaces between them. In this way, explain the authors, the molecules are deposited "like snowflakes", forming a highly homogeneous plastic. It is precisely in the interstices between the rails of silicon, filled with new material, that the light passes at high speed, allowing you to transmit data up to 170 Gigabit per second (with the traditional structures, which consist only of silicon, you can reach a maximum speed around 20-30 Gigabit per second). Combining silicon with an architecture was needed to channel and confine the flow of light within very small spaces (the guide of silicon is separated by a few tens of nanometers).
The new devices can operate at 30 degrees above zero, rather than less than 70. This is the characteristic of the new generation of semiconductors, researched at the Italian Institute for the Physics of Matter (INFM-CNR), and in the Ludwig Maximilian University in Monaco of Bavaria and the ETH Zurich (the study).
Today there are two ways to record information on a medium: the electronic format, in which the binary language is the passage of electrons (the transistors) and magnetic (MRAM memory), more recently, in which the binary language is given by state of magnetization. To communicate these two systems could boost significantly the computational schemes, pending the distant quantum computer. Doubling the processing power and memory of a chip while maintaining the size, without the need to go in nano-scale (a scale, that is, a billionth of a meter) are just two of the technology that promises magnetic semiconductors suggest a near future.
These devices were made over ten years ago, but so far required temperatures far below zero to work. The problem now seems outdated as the known semiconductors gallium arsenide containing traces of manganese, a metal which has ferromagnetic properties at around 200 degrees below zero. To increase the temperature threshold, above which the ferromagnetic behavior disappears, the researchers deposited on a semiconductor film of iron - metal known for its magnetic properties - the thickness of a few nanometers.
Iron and manganese interacted so effectively that the new material, has a ferromagnetic behavior up to 30 degrees above zero, a jump of over a hundred degrees above the starting temperature.
This result is a technological response parallel to that of the race to miniaturization and the research was selected the American Physical Society as one of the most important published in Physical Review Letters
For the first time a gene was identified that allows the repair of damaged nerves in nematodes. The study is from Science Express.
A gene that can stimulate the growth of nerve cells was first identified by researchers at the University of Utah (USA), thanks to cutting-edge experimental techniques and a huge genetic screening on a nematode (cylindrical or worm).
The neurons, which in the embrio are able to regenerate, in adults have their capacity to "repair" reduced or absent. In other words, damage to the central nervous system (brain or spinal cord) and its consequences - paralysis, loss or reduction of cognitive faculties - are permanent.
"In the past molecules have been identified that can inhibit the growth of neurons in different organisms," says the coordinator of research Michael Bastiani, "but their removal in the laboratory had no effect. That is why we went to look for those genes that can stimulate rather than inhibit, the regeneration of nerve. "
Taking as a experimental model flat worms (Caenorhabditis elegans), biologists have searched for the genes that trigger the regrowth of motor (neurons that "command" voluntary muscles): in practice, with an experimental technique called RNA interference to "shut down ", one by one, 5000 on 20,000 genes in the DNA of worms (genes similar are also present in humans).
The analysis led to the identification of dlk-1, which appears to play a key role in the regeneration of nerve tissue, and three other genes responsible for the formation of axons (parts of the neuron that conduct electrical signal).
The researchers found that in nematodes, the gene dlk-1 not only triggers a chain of events known as "Map kinase" behind the growth of neurons, but also that their regeneration can be increased or decreased by stimulating the gene to produce amounts more or less high of the protein dlk-1.
The molecule slows the proliferation of tumor cells while giving the time needed to repair the damage to their DNA. The discovery, made by Italian researchers IEA, is published in Nature.
The secret of immortality of cancer stem cells - those that feed it and cause relapses because they're immune to chemotherapy - was unveiled. Their strength is the p21 protein that slows the proliferation, giving them the time needed to repair damage to DNA. In practice, it is as if these cells were able to rejuvenate indefinitely: no age, and thus do not die. By blocking the production of p21, however, you can make them vulnerable and hit the tumor at the root.
The research was conducted in the laboratories of the European Institute of Oncology (IFOM-IEO) in collaboration with the universities of Milan and Perugia, and was published this week in Nature.
The cells age and die because they accumulate damage and mistakes borne of DNA during cell divisions. To understand why this does not happen in a cancerous stem cell, the researchers observed what happens to a staminale "normal" when you alter one of the genes (oncogenes) that cause cancer (in this case, the acute myeloid leukemia).
The study revealed that oncogenes stimulate the activity of another gene, called p21, and thus the production of the corresponding protein, whose effect is to slow the proliferation. In essence, these cells have much more time to repair other damaged DNA, and remain young and active, immune to chemotherapy drugs because they recognize and affect only the cells in rapid proliferation.
The switch that turns off and on to command the superconducting property of the new device is a trivial electric field. In practice, what has been done by Andrea Ankle and colleagues at the University of Geneva in the first superconducting transistors. The operation, represents a milestone of applied physics and paves the way for the development of a new generation of microchips - and therefore computers - much faster than at present.
To understand how and why the device is considered so promising it must be from another discovery, made last year by the same group of university research in Switzerland and published in Science. In one study, physicists have created a single crystal in which two metal oxides (strontium titanate and lanthanum aluminate) are separated. Between these two materials, researchers have found a layer of free electrons (electronic cloud) and 0.3 Kelvin - that is just above absolute zero - traveling without any resistance. At that temperature, the crystal becomes a superconductor.
Scientists have now discovered how to turn off and turn on the superconductivity of this crystal at will, or modules, simply by applying an electric field to the point of contact between the two oxides. The result is a version of superconductive field effect transistors (FET) devices known in applied physics, able to switch from one state to a semiconductor insulator, and basic digital information in electronics (the fact that the current can pass or not is used as a binary 1-0 to store information).
As the field effect transistors is a semiconductor, however, it always has resistance to the passage of current. This means that the speed at which you can get the electrons when the device is "on" is limited which means heat develops beyond a certain limit. This side effect is damaging the transistor.
A superconducting transistor, however, can pass electrons (and record information) much more quickly, as it does not oppose any resistance to the passage of current and, therefore, not heat. There remains the problem of extremely low temperatures required for superconductivity. A limit that research is a long time trying to overcome.
By comparing DNA of healthy and cancerous tissue of a single person, there were discovered eight new mutations linked to the disease. The study in Nature
The complete genome of a person suffering from cancer was decoded for the first time. The comparison between the DNA of normal and cancerous tissue of a woman suffering from acute myeloid leukemia (AML) has identified ten mutations in the genome of cancer cells, including eight so far unknown, which would be linked to the disease. Researchers of the Washington University School of Medicine (USA), coordinated by Richard K. Wilson, presented their findings in Nature.
Scientists have taken a sample of tissue from normal skin and a tumor tissue from bone marrow to a patient suffering from AML - cancer that affects the bone marrow cells that produce red blood cells. Subsequently they have decoded the DNA of the two tissues, comparing all three billion bases of which the genomes were composed, to go back to differences in disease characteristics of the individual.
There were ten mutations identified, two already known, eight first ever linked to the disease. Of those, three were found in genes that normally can block the growth of tumors (for example in Ptprt, the tyrosine phosphatase gene, often altered in colon cancer). Four changes instead involved genes regulate the molecular pathways that promote tumor development - particularly in a family of genes, usually expressed in embryonic stem cells, which could stimulate cell renewal. A final disturbing deterioration instead of transporting drugs into the cell. According to scientists, these mutations have occurred one after another, each adding something new to the tumor.
The habitual consumption of alcohol reduces the size of brain mass. This suggests a study in Neurology magazine.
The more we drink, the more our brains will decrease. To suggest this is a report of Wellesley College, Massachusetts, published in the journal Archives of Neurology (a publication of Jama) and this week the American Academy of Neurology.
We know that the volume of the brain decreases with age (about 1.9 percent every ten years). This physiological reduction is accompanied by an increase in white matter lesions and both factors - reminiscent of the authors - are related to cognitive problems like memory.
While some scholars have suggested a possible positive effect of alcohol on reducing the normal volume of brain mass, this new study suggests just the opposite. Data was collected on a sample of over 1,800 individuals aged between 55 and 64 years, most consumers of alcohol or ex-drinkers, which carried out magnetic resonance (participants in the Framingham Offspring fall Study, a study of the cardiovascular problems started in 1971, for which it was collected information on weekly consumption of alcohol, sex, body mass index and other physiological parameters). The results show that there is a significant correlation between alcohol intake and reduction of brain volume, especially in women which usually consume less alcohol than men.
Npas4: This protein regulates the formation of inhibitory synapses between neurons.
The inhibitory activity of neurons is regulated by a particular switch. This is a protein involved in the formation and maintenance of synapses in regulating selectively switching the electrical signal between nerve cells. Its name is Npas4 and was discovered by researchers from the Children's Hospital in Boston this week to publish their study in Nature.
In particular, the protein in question is a transcription factor, that is a molecule that can activate or deactivate specific genes. Those which would be linked to Npas4 are more than 270. When the protein is produced in large quantities, we are seeing an increase in the number of inhibitory synapses on the surface of nerve cells.
But what induces the production of high levels of Npas4? According to the researchers this is a reaction to excitatory synaptic. "It is as if the same excitement triggers a program to rebalance the brain with inhibition," says Michael Greenberg, coordinator of the study, which continues: "The mice in which the protein is suppressed, in fact, have neurological problems: are anxious, hyperactive and more subject to seizures. " The discovery could help researchers in studying these disorders. Inhibition, in fact, plays an important role in brain development.
To isolate individual cells of the immune system and study the interaction in order to improve the treatment of cancer. At this will serve the new biosensor prototype developed under the project Cochise (Cell-On-CHIp bioSEnsor), supported by the European Union and coordinated by Roberto Guerrieri, professor of Electronics at the Faculty of Engineering, University of Bologna .
The biological approach used to treat cancer patients consisting of interferon, interleukin-2 or other factors stimulating the growth of different cell types and able to reinforce the natural defenses of the body. But these substances are not always well tolerated. An alternative approach is to identify the immune cells able to fight cancer, cultivate them in vitro and then re-introduce them in the body. But here the problem lies in identifying and in isolating the small number of cells that are selectively able to fight cancer.
The objective of the project Cochise (which is intended to last three years), is to develop a new class of biosensors capable of isolating cells (not more than 1 in 10 thousand) that are actually effective in fighting cancer cells . As the first objective was developed a prototype, used to demonstrate the possibility of controlling the flow of two individual cells and putting them in a display where you can study the interaction.
The mutation of the gene Alk would be responsible for inherited forms of cancer.
Neuroblastoma is a childhood cancer more widespread and aggressive: it attacks the autonomic nervous system during development, forming frequently in tumor masses or into the chest. A study, published in Nature and coordinated by the Children Hospital of Philadelphia (USA), indicates that mutations in the gene anaplastic lymphoma kinase (Alk) would be responsible for inherited forms of the disease.
The international group of researchers, including some of the Italian Institute for Cancer Research in Genoa, have collected genetic information of 20 families where the disease was presented in more than one occasion, by analyzing the DNA of 176 people ( of which 49 with neuroblastoma). Eight families, in which at least three individuals suffering from the disease were closely analyzed, possessed the changed Alk gene. The normal role of this gene, which expresses a transmembrane receptor, is not yet understood in depth but, according to previous studies, its alterations increase the risk of developing lymphoma or lung cancer.
The brain responds to stimuli, tactile and visual contradiction in delaying the processing of information that comes from the skin.
A fly is laying on the right elbow. Slight itching, moving vision towards the elbow, identification of the intruder and its position and, finally, blow. This reaction is not as instantaneous as you can imagine. Indeed, the brain seems to delay affixed aware of the tactile perception, as reported a study in Current Biology Group for Research in Cognitive Neuroscience (Grnc) in Barcelona.
The brain is often having to generate rapid responses integrating stimuli that produce information in contradiction: if, for example, the subject has crossed his arms and brings his right arm on the left side and left arm on the right side, his hands will be in a position that is reversed from the original location. In this case, the brain must be able to correctly integrate the information of the tactile stimulus (for example pinch) on the right hand, although the visual stimulus comes in fact from the left. To avoid mistakes the brain needs time to make a realignment of the information space of two different maps: that rof the body and one that covers everything else.
To understand how the mechanism works, researchers have assessed the response of 32 university students to a series of visual and tactile stimuli. Each student has been subjected to 600 tests. "First we asked participants to cross the arms, so that the position of hands was in conflict with the anatomical position" says Salvador Soto-Faraco, one of the authors of the study, "we have stimulated one of two hands." Few tenths of a second later, a small light (visual stimulus) I had left or right. Both the tactile stimuli that those visual products were in a totally random. In addition, the flash of light could be generated 60 or 200 milliseconds after the tactile stimulus. In order to assess whether the time elapsed between the two stimuli does influence or not the answer.
The asymmetry of the skull of flatfish is the result of a progressive adaptation of the species. A study in Nature
The bizarre anatomy of flatfish had surprised even Charles Darwin, which had not managed to find an explanation for the asymmetry of their skull. All adult in this family - including the sole, turbot, halibut - in fact, have both eyes on the top of the head. But in fossils of fish of their progenitors, this feature was absent. The mystery of the asimmetric skull is now being revealed by a study carried out by Matt Friedman, a researcher at the Committee on Evolutionary Biology and the University of Chicago and State Department of Geology at the Field Museum and published in Nature: in the Eocene era, about 50 million years ago, there were fish with intermediate characteristics.
The U.S. researcher says it is enough to review the collections of fossils preserved in museums in some European countries (Italy, France, Austria, United Kingdom) to be able to find two kinds primitive - Amphistium, described for the first time more than 200 years ago, and the Heteronectes, unknown until now - in which the eye migration is partial. "We discovered thus an intermediate stage of development of these species," said Friedman, "showing that the asymmetry of the head of the fish we know today is the result of a gradual natural evolution."
A study explains how a yeast cell becomes cancerous: the fault is a chromosomal translocation
An altering of the genome that causes cancer was finally detected and reproduced in the laboratory. The discovery, crucial for understanding the genesis and development of malignancies, is due to the geneticist Charles V. Bruschi, head of the Laboratory of Molecular Genetics of yeast, International Centre for Genetic Engineering and Biotechnology in Trieste (Icgeb) and coordinator of the Society of Italian scientific yeast (Zymi).
Together with his group, Bruschi has uncovered, that the so-called chromosomal translocation is at fault. The yeast cells, whose DNA was sequenced completely in 1996, are a good model because they possess many similarities with mammalian cells and are easily manipulated by genetic engineering. Thanks to technical Bit (Bridge-Induced Translocation), designed by Bruschi and Valentina Tosato in 2005, it was possible to artificially induce the translocation and demonstrate the crucial role of this phenomenon in the formation of cancer. "Although it has long been a correlation between the presence of chromosomal translocations and the appearance of cancer cells," explains Bruschi, "so far it was not clear whether a translocation was the origin of cancer or whether, instead, it was a consequence. This is because we see patients when the cancer has already formed and in the cells already exists a particular translocation. In practice, these observations are made when it is too late to establish a relationship of cause and effect. "
The ventral striatum, a part of the brain already known to be associated with rewards and unexpected stimuli, is the center of our desire for adventure. The research in Neuron.
A group of researchers from the Wellcome Trust Centre for Neuroimaging at the University College of London has identified the area of the brain directly linked to our desire for adventure. Or, more precisely, our propensity to live new experiences and to experience what we do not know.
For the study, published in Neuron, researchers have developed a test: the participants were presented a series of images associated with different sums of money put into a premium, and were asked to guess which of the sums was higher. Although the volunteers easily could identify the image associated with richer rewards, when it was introduced a new figure, all of them tended to choose the latter rather than those already known with secure profits. Through magnetic resonance imaging, neuroscientists have noticed that the area of the ventral Striatum (an area of the brain already known to be associated to receive a reward and unexpected stimuli) was particularly active when participants opted for the novelty.
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