#How metallic alloys reorganize during microscale laser melting processes: Elements of successful connections High-power lasers that can selectively cut
Researchers investigating the feasibility of 3d printed implant materials often turn to magnesium-aluminum (Mg-Al) alloys
tough and biocompatible. Recently, the A*STAR team demonstrated that laser surface melting of these alloys enhances their corrosion resistance as a result of a notable enhancement in the surface concentration of aluminum.
It is difficult, however, to make the link between the initial alloy composition and the final product after laser processing,
as many complex interactions occur in the cloudlike plume of laser-generated vapor particles. Guan and her team designed a new experimental setup that can quantify
which molten alloy elements are ejected into the laser plume. They positioned a thin silicon substrate perpendicular to a Mg-Al-based alloy a few millimeters from the laser firing point.
Laser pulses then generated a plume that deposited onto the silicon surface. When the researchers used a scanning electron microscope (SEM) to examine the deposits,
they saw clear evidence of a phase explosion--a mixture of liquid and vaporized particles thrown out by the laser impact.
the population of Al ions rises in the middle of the near-field region close to the laser firing point.
Guan notes that the site-specific analytical capabilities of this technique should give researchers finer control over selective surface vaporization of alloying elements for enhanced, high-tech applications."
"Our chemical analysis of the transport rates and distribution of vaporized species in the plume offers improved understanding of critical laser processes, including those used in additive manufacturing,
#Double blast to ward off pneumonia: Dry powder inhaler formulation Despite advances in vaccination and antimicrobial therapy, community-acquired pneumonia remains a leading cause of morbidity and mortality, even in highly developed countries.
Desmond Heng, Reginald Tan and co-workers at the A*STAR Institute of Chemical and Engineering sciences have developed now a dry powder inhalation formulation to treat bacterial infections associated with this disease1.
Community-acquired pneumonia, a type of lung inflammation contracted outside of a hospital or nursing-home setting, is caused most often by infections with bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus.
The condition affects people of all ages but is particularly prevalent among infants, the elderly and patients with chronic obstructive pulmonary disease.
The formulation developed by the team contains two important ingredients: ciprofloxacin hydrochloride (CIP), an antibiotic commonly used to eliminate pathogenic bacteria,
"Our follow-up microbial assays show that a concentration as low as one microgram per milliliter is enough to inhibit three of the bacteria known to cause this type of pneumonia.""
""We found that it is feasible to package the CIP-BP dry powder in an inhaler that can treat bacterial infections associated with community-acquired pneumonia,
The delivery of CIP and BP via dry powder inhalers may become a novel and useful strategy for treating patients with community-acquired pneumonia a
#Smallest world record has ndless possibilitiesfor bionanotechnology Scientists from the University of Leeds have taken a crucial step forward in bionanotechnology a field that uses biology to develop new tools for science technology and medicine.
demonstrates how stable'lipid membranes'--the thin'skin'that surrounds all biological cells--can be applied to synthetic surfaces.
Importantly, the new technique can use these lipid membranes to'draw'--akin to using them like a biological ink--with a resolution of 6 nanometres (6 billionths of a meter
and promises the ability to position functional biological molecules--such as those involved in taste, smell,
"said Professor Steve Evans, from the School of Physics and Astronomy at the University of Leeds and a co-author of the paper.
In the study, the researchers used something called Atomic force microscopy (AFM), which is an imaging process that has a resolution down to only a fraction of a nanometer
and works by scanning an object with a miniscule mechanical probe. AFM however, is more than just an imaging tool
and can be used to manipulate materials in order to create nanostructures and to'draw'substances onto nano-sized regions.
The latter is called'nanolithography 'and was used the technique by Evans and his team in this research. The ability to controllably'write
'and'position'lipid membrane fragments with such high precision was achieved by George Heath, a Phd student from the School of Physics and Astronomy at the University of Leeds and the lead author of the research paper.
Heath said:""The method is much like the inking of a pen. However, instead of writing with fluid ink, we allow the lipid molecules--the ink--to dry on the tip first.
which is the natural environment for lipid membranes. Previously, other research teams have focused on writing with lipids in air
and to aid our understanding of a range of diseases, "explained Evans. Aside from biological applications,
this area of research could revolutionise renewable energy production. Working in collaboration with researchers at the University of Sheffield,
Evans and his team have all of the membrane proteins required to construct a fully working mimic of the way plants capture sunlight.
the researchers will be able to arbitrarily swap out the biological units and replace them with synthetic components to create a new generation of solar cells.
Evans concludes:""This is part of the emerging field of synthetic biology, whereby engineering principles are being applied to biological parts
--whether it is for energy capture, or to create artificial noses for the early detection of disease
or simply to advise you that the milk in your fridge has gone off.""The possibilities are endless. l
#Laser comb system maps 3-D surfaces remotely for manufacturing, forensics Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a laser-based imaging system that creates high-definition 3d maps of surfaces from as far away as 10.5 meters.
The method may be useful in diverse fields including precision machining and assembly as well as in forensics.
NIST's 3d mapping system combines a form of laser detection and ranging (LADAR) which is sensitive enough to detect weak reflected light with the ranging accuracy made possible by frequency combs as previously demonstrated at NIST.
--which is safe for the eyes at the instrument's infrared wavelength--NIST's 3d mapping system scans a target object point by point across a grid measuring the distance to each point.
The system uses the distance data to make a 3d image of about 1 million pixels in less than 8. 5 minutes at the current scanning rate.
NIST researchers demonstrated the range by scanning footprints in soil vegetation such as cactus (imaging individual spines) and complex mechanical devices such as a piston for a motorcycle.
The NIST system is similar to optical coherence tomography for example but can operate much farther away from the target
and is detected by a sensor. In the NIST LADAR system the laser sweeps continuously across a band of frequencies.
and analyzed by digital signal processing to generate time delay data which is used to calculate the distance.
Finally the system uses real-time fast processing digital electronics to produce fully calibrated 3d megapixel images.
#Universal Ebola drug target identified by researchers University of Utah biochemists have reported a new drug discovery tool against the Ebola virus.
that displays a functionally critical region of the virus that is universally conserved in all known species of Ebola.
The University of Utah (U of U) work which was funded by the National institutes of health, was conducted by a large collaborative team led by Debra Eckert,
Ph d.,(research assistant professor of biochemistry) and Michael Kay, M d.,Ph d.,(professor of biochemistry). Key contributions to this work were provided by Dr. John Dye's laboratory at the U s army Medical Research Institute of Infectious diseases (USAMRIID), the lab of Christopher P. Hill, D. Phil.
professor and co-chair of the U of U Department of Biochemistry, and a group led by Brett Welch, Ph d. at Navigen, Inc.,a Salt lake city pharmaceutical discovery and development company.
Navigen has licensed exclusive rights to the technology from the U of U and is currently screening for drugs against the target.)
initiating infection. Importantly, the researchers were able to demonstrate this peptide target is suitable for use in high-throughput drug screens.
These kinds of screens allow rapid identification of potential new drugs from billions of possible candidates.
Current experimental drugs generally target only one of Ebola's five species."The current growing epidemic demonstrates the need for effective broad-range Ebola virus therapies,
"says Dr. Tracy R. Clinton, lead author on the study.""Importantly, viral sequence information from the epidemic reveals rapid changes in the viral genome,
while our target sequence remains the same. Therefore, our target will enable the discovery of drugs with the potential to treat any future epidemic,
even if new Ebola virus strains emerge.""Ebola is a lethal virus that causes severe hemorrhagic fever with a 50 percent to 90 percent mortality rate.
There are five known species of the virus. Outbreaks have been occurring with increasing frequency in recent years,
and potential bioterror exposures is an urgent global health need. There are no approved anti-Ebola agents,
"Although the current push of clinical trials will hopefully lead to an effective treatment for the Zaire species causing the present epidemic,
or new Ebola species. Development of a broadly acting therapy is an important long-term goal that would allow cost-effective stockpiling of a universal Ebola treatment."
and less expensive to produce compared to the current most promising approach, antibodies. The Utah group has developed previously highly potent and broadly acting D-peptide inhibitors of HIV entry, currently in preclinical studies,
and is now adapting this approach to Ebola using the mimics developed in this study. In collaboration with Navigen
U of U and Navigen are now seeking additional funding to optimize these inhibitors and advance them into clinical trials in humans s
#New lab-on-a-chip could revolutionize early diagnosis of cancer Scientists have been laboring to detect cancer and a host of other diseases in people using promising new biomarkers called exosomes.
Indeed Popular Science magazine named exosome-based cancer diagnostics one of the 20 breakthroughs that will shape the world this year.
Exosomes could lead to less invasive earlier detection of cancer and sharply boost patients'odds of survival.
Exosomes are minuscule membrane vesicles --or sacs--released from most if not all cell types including cancer cells said Yong Zeng assistant professor of chemistry at the University of Kansas. First described in the mid-'80s they were thought once to be'cell dust
'or trash bags containing unwanted cellular contents. However in the past decade scientists realized that exosomes play important roles in many biological functions through capsuling
and delivering molecular messages in the form of nucleic acids and proteins from the donor cells to affect the functions of nearby or distant cells.
While the average piece of paper is about 100000 nanometers thick exosomes run just 30 to 150 nanometers in size.
which is a key setback in clinical development of exosomal biomarkers. Now Zeng and colleagues from the University of Kansas Medical center and KU Cancer Center have published just a breakthrough paper in the Royal Society of Chemistry journal describing their invention of a miniaturized biomedical testing device for exosomes.
Dubbed the lab-on-a-chip the device promises faster result times reduced costs minimal sample demands and better sensitivity of analysis when compared with the conventional bench-top instruments now used to examine the tiny biomarkers.
A lab-on-a-chip shrinks the pipettes test tubes and analysis instruments of a modern chemistry lab onto a microchip-sized wafer Zeng said.
Also referred to as'microfluidics'technology it was inspired by revolutionary semiconductor electronics and has been under intensive development since the 1990s.
Essentially it allows precise manipulation of minuscule fluid volumes down to one trillionth of a liter
or less to carry out multiple laboratory functions such as sample purification running of chemical and biological reactions and analytical measurement.
Zeng and his fellow researchers have developed the lab-on-a-chip for early detection of lung cancer--the number-one cancer killer in the U s. Today lung cancer is detected mostly with an invasive biopsy after tumors are larger than 3 centimeters in diameter and even
metastatic according to the KU researcher. Using the lab-on-a-chip lung cancer could be detected much earlier using only a small drop of a patient's blood.
Most lung cancers are diagnosed first based on symptoms which indicate that the normal lung functions have been damaged already Zeng said.
Unlike some cancer types such as breast or colon cancer no widely accepted screening tool has been available for detecting early-stage lung cancers.
Diagnosis of lung cancer requires removing a piece of tissue from the lung for molecular examination.
Tumor biopsy is often impossible for early cancer diagnosis as the developing tumor is too small to see by the current imaging tools.
In contrast our blood-based test is minimally invasive inexpensive and more sensitive thus suitable for large population screening to detect early-stage tumors.
Zeng said the prototype lab-on-a-chip is made of a widely used silicone rubber called polydimethylsiloxane and uses a technique called on-chip immunoisolation.
We used magnetic beads of 3 micrometers in diameter to pull down the exosomes in plasma samples Zeng said.
In order to avoid other interfering species present in plasma the bead surface was modified chemically with an antibody that recognizes
and binds with a specific target protein--for example a protein receptor--present on the exosome membrane.
The plasma containing magnetic beads then flows through the microchannels on the diagnostic chip in which the beads can be collected readily using a magnet to extract circulating exosomes from the plasma.
Beyond lung cancer Zeng said the lab-on-a-chip could be used to detect a range of potentially deadly forms of cancer.
Our technique provides a general platform to detecting tumor-derived exosomes for cancer diagnosis he said.
In addition to lung cancer we've also tested for ovarian cancer in this work. In theory it should be applicable to other types of cancer.
Our long-term goal is to translate this technology into clinical investigation of the pathological implication of exosomes in tumor development.
Such knowledge would help develop better predictive biomarkers and more efficient targeted therapy to improve the clinical outcome.
Story Source: The above story is provided based on materials by University of Kansas. Note: Materials may be edited for content and length.
Journal Reference e
#Live and let-7: microrna plays surprising role in cell survival Researchers at the University of California San diego School of medicine have identified a microrna molecule as a surprisingly crucial player in managing cell survival and growth.
The findings published in the October 7 issue of Cell Metabolism underscore the emerging recognition that non-coding RNAS small molecules that are translated not into working proteins help regulate basic cellular processes
and may be key to developing new drugs and therapies. Specifically principal investigator Albert R. La Spada MD Phd professor of cellular and molecular medicine chief of the Division of Genetics in the Department of Pediatrics and associate director of the Institute for Genomic medicine
at UC San diego and colleagues found that a microrna known as let-7 controls autophagy through the amino acid sensing pathway which has emerged as the most potent activator of mtorc1 complex activity.
Autophagy is a fundamental process used by cells to degrade unnecessary components in times of starvation releasing energy stores that help promote cell survival.
Cells have adapted further autophagy for other purposes as well including recycling dysfunctional components immune response to pathogen invasion surveillance against cancer
and maintenance of protein and organelle control in the central nervous system. MTORC1 is a critical protein complex that regulates energy consumption
and growth in cells. he ability of let-7 alone to activate autophagy in this way was totally unknown
and is very surprisingsaid La Spada. s let-7 is known to be a tumor suppressor its ability to activate autophagy could be a major component of its anti-tumor forming activitythough La Spada noted that autophagy may also contrarily promote tumor progression
by supporting the altered metabolism of growing cancers. With let-7 revealed to be a master regulator of metabolism helping to modulate anabolic growth (the creation of new molecules in cells) with catabolic destruction (the breakdown of molecules in cells) researchers say the overall picture
of how cells function becomes more fine-tuned but also more complicated. he fact that let-7 is opposing the action of the amino acid sensing pathway provides a glimpse into the complex pathway regulation at work in the cell with micrornas emerging as important factors for cells to maintain metabolic set points
and overall homeostasis or a healthy equilibrium. he therapeutic potential of let-7 remains to be explored.
La Spada said he and colleagues have shown that a lentivirus encoding let-7 injected into mouse neurons promotes the autophagic turnover of toxic misfolded proteins associated with neurodegenerative disease. e also demonstrate that treatment with anti-let-7 can block autophagy
and that this has physiological consequences (weight gain) in mice. It is possible that modulation of let-7 could be pursued for therapeutic application using very carefully targeted delivery systems
but further work will be necessary to see if this is practically possible. tory Source: The above story is provided based on materials by University of California San diego Health Sciences.
Note: Materials may be edited for content and length. Journal Reference g
#Small molecule jams the switch to prevent inflammatory cell death Walter and Eliza Hall Institute scientists have discovered a small molecule that blocks a form of cell death that triggers inflammation opening the door for potential new treatments for inflammatory disease such as rheumatoid arthritis Crohn's disease
and psoriasis. The researchers made the discovery while investigating how a protein called MLKL kills cells in a process known as necroptosis.
Their findings were published today in the journal Proceedings of the National Academy of Sciences. Necroptosis is discovered a recently cell death pathway linked to immune disorders.
It is a vital process in which cells undergo programmed death while warning the immune system that something has gone wrong such as during viral infection.
However when necroptosis is activated inappropriately it can promote inflammation and the development of inflammatory disease. Dr Joanne Hildebrand Ms Maria Tanzer Dr James Murphy Associate professor John Silke and colleagues studied how MLKL changes shape to trigger cell death.
MLKL is the final protein in the cell death pathway but it needs to be activated before it can kill the cell Dr Hildebrand said.
Understanding how it becomes active can help uncover new ways to treat disease. Dr Hildebrand said the research team found that a particular part of the protein became'unlatched
'when activated allowing it to attach to the cell membrane and trigger cell death. It's like flicking a molecular switch she said.
We showed that when the switch can't be turned on'MLKL doesn't become active
and necroptosis is prevented. Ms Tanzer said the team tested a range of small molecules to see
if any could stop the switching on of MLKL and had identified one that prevented MLKL from becoming active.
Dr Murphy said institute scientists would now embark on a collaborative project with Catalyst Therapeutics to develop a potent new drug based on the small molecule identified in the study.
and improve treatments for inflammatory disease e
#Anorexia/bulimia: Bacterial protein implicated Eating disorders (ED) such as anorexia nervosa bulimia and binge eating disorder affect approximately 5-10%of the general population
but the biological mechanisms involved are unknown. Researchers at Inserm Unit 1073 Nutrition inflammation and dysfunction of the gut-brain axis (Inserm/University of Rouen) have demonstrated the involvement of a protein produced by some intestinal bacteria that may be the source of these disorders.
Antibodies produced by the body against this protein also react with the main satiety hormone
which is similar in structure. According to the researchers it may ultimately be possible to correct this mechanism that causes variations in food intake.
These results are published in the journal Translational Psychiatry in the online issue of 7 october 2014.
Anorexia nervosa bulimia and binge eating disorder are all eating disorders (ED) . If the less well defined and atypical forms are included ED affect 15-20%of the population particularly adolescents and young adults.
Despite various psychiatric genetic and neurobiological studies the molecular mechanism responsible for these disorders remains mysterious.
The common characteristic of the different forms of ED is dysregulation of food intake which is decreased
Sergueï Fetissov's team in Inserm Joint Research Unit 1073 Nutrition inflammation and dysfunction of the gut-brain axis (Inserm/University of Rouen) led by Pierre Déchelotte studies the relationships
Where this protein is present antibodies are produced against it by the body. These will also bind to the satiety hormone because of its structural homology to Clpb
The sensation of satiety is reached (anorexia) or not reached (bulimia or overeating). Moreover the bacterial protein itself seems to have anorexigenic properties.
Food intake and level of antibodies against melanotropin in the 1st group of mice which were given mutant E coli bacteria (not producing Clpb) did not change.
In contrast antibody level and food intake did vary in the 2nd group of animals which received E coli producing Clpb protein.
The likely involvement of this bacterial protein in disordered eating behaviour in humans was established by analysing data from 60 patients.
Plasma levels of antibodies to Clpb and melanotropin were higher in these patients. Furthermore their immunological response determined the development of eating disorders in the direction of anorexia or bulimia.
These data thus confirm the involvement of the bacterial protein in the regulation of appetite and open up new perspectives for the diagnosis and specific treatment of eating disorders.
Correcting the action of the protein mimicking the satiety hormonewe are presently working to develop a blood test based on detection of the bacterial protein Clpb.
If we are successful in this we will be able to establish specific and individualised treatments for eating disorders say Pierre Déchelotte and Sergueï Fetissov authors of this study.
According to our initial observations it would indeed be possible to neutralise this bacterial protein using specific antibodies without affecting the satiety hormone they conclude.
#New pathway discovered regulating autoimmune diseases The main function of the immune system is to protect against diseases and infections.
which can result in diseases such as multiple sclerosis type 1 diabetes lupus or rheumatoid arthritis. There are currently no existing cures for these diseases.
Now in a new study by researchers at Brigham and Women's Hospital (BWH) a potential treatment maybe on the horizon.
and food protects against autoimmune diseases by altering the immune response and turning destructive cells into protective cells.
The molecule is also able to reverse disease progression by restoring damaged tissue caused by the autoimmunity process.
and restore tissue integrity by activating stem cells said Abdallah Elkhal Phd BWH Division of Transplant Surgery and Transplantation Surgery Research Laboratory senior study author.
and may serve for the development of novel therapeutics. The study is published online October 7 2014 in Nature Communications.
The scientists performed preclinical trials using experimental autoimmune encephalomyelitis a preclinical model for human multiple sclerosis.
or chronic inflammation by regulating how immune cells called CD4+T cells differentiate. Mice receiving CD4+T cells along with NAD+present had delayed a significant onset of disease as well as a less severe form
therefore demonstrating the molecule's protective properties. This is a universal molecule that can potentially treat
not only autoimmune diseases but other acute or chronic conditions such as allergy chronic obstructive pulmonary disease sepsis and immunodeficiency said Stefan G. Tullius MD Phd BWH Chief of Transplant Surgery
and Director of Transplantation Surgery Research lead study author. Moreover the researchers demonstrated that NAD+can restore tissue integrity
which may benefit patients that have advanced tissue damage caused by autoimmune diseases. In terms of next steps Elkhal notes that the lab is currently testing additional pathways and the clinical potential of NAD+.
Thus we hope that its potential as a powerful therapeutic agent for the treatment of autoimmune diseases will facilitate its use in future clinical trials.
The above story is provided based on materials by Brigham and Women's Hospital. Note: Materials may be edited for content and length.
Dynamic encryption keeps secrets Professor Lars Ramkilde Knudsen from DTU Compute has invented a new way to encrypt telephone conversations that makes it very difficult to'eavesdrop'.
This is a brief definition of dynamic encryption, the brainchild of Professor Lars Ramkilde Knudsen from DTU.
Together with telecommunications businessman Kaj Juul-Pedersen, he established the company Dencrypt, which sells dynamic encryption to businesses
so they can safely exchange confidential information over the telephone.""Today, all telephone conversations are encrypted --i e. converted into gibberish
--but they are encrypted not all the way from phone to phone, and if a third party has access to one of the telephone masts through which the call passes,
they can listen in, "explains Lars Ramkilde Knudsen.""And even if the conversation is encrypted--in principle--it is still possible to decrypt it provided you have sufficient computer power,
"he says. This is in no small part due to the fact that the vast majority of telecommunications operators use the same encryption algorithm--the so-called AES,
the outcome of a competition launched by the US government in 1997.""This is where my invention comes in,
It expands the AES algorithm with several layers which are never the same. Dynamic encryption"When my phone calls you up, it selects a system on
Technically speaking, it adds more components to the known algorithm. The next time I call you,
The clever thing about it is that your phone can decrypt the information without knowing which system you have chosen.
and encryption method--and both are thrown away by the phone after each call and replaced by a new combination--the conversation is extremely difficult to decrypt
budgets and secret plans using phone tapping, for example. In the USA alone, the phenomenon costs businesses around USD 100 billion every year according to a 2014 report on the subject by security firm Mcafee.
Dencrypt currently has six employees in addition to co-owner and founder Lars Ramkilde Knudsen who still works for DTU Compute.
If everything goes according to plan, the product will be ready for sale on 24 october 2014 4
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