David Kirkpatrick

July 12, 2010

Latest advance in nanoscience research

News like this is important because a lot of the science of nanotechnology is so new it’s essentially a high-wire act without a net. Working to set some baselines in nanoscience help to improve the entire field.

The release:

University of Toronto chemists make breakthrough in nanoscience research

TORONTO, ON – A team of scientists led by Eugenia Kumacheva of the Department of Chemistry at the University of Toronto has discovered a way to predict the organization of nanoparticles in larger forms by treating them much the same as ensembles of molecules formed from standard chemical reactions.

“Currently, no model exists describing the organization of nanoparticles,” says Kumacheva. “Our work paves the way for the prediction of the properties of nanoparticle ensembles and for the development of new design rules for such structures.”

The focus of nanoscience is gradually shifting from the synthesis of individual nanoparticles to their organization in larger structures. In order to use nanoparticle ensembles in functional devices such as memory storage devices or optical waveguides, it is important to achieve control of their structure.

According to the researchers’ observations, the self-organization of nanoparticles is an efficient strategy for producing nanostructures with complex, hierarchical architectures. “The past decade has witnessed great progress in nanoscience – particularly nanoparticle self-assembly – yet the quantitative prediction of the architecture of nanoparticle ensembles and of the kinetics of their formation remains a challenge,” she continues. “We report on the remarkable similarity between the self-assembly of metal nanoparticles and chemical reactions leading to the formation of polymer molecules. The nanoparticles act as multifunctional single units, which form reversible, noncovalent bonds at specific bond angles and organize themselves into a highly ordered polymer.”

“We developed a new approach that enables a quantitative prediction of the architecture of linear, branched, and cyclic self-assembled nanostructures, their aggregation numbers and size distribution, and the formation of structural isomers.”

Kumacheva was joined in the research by postdoctoral fellows Kun Liu, Nana Zhao and Wei Li, and former doctoral student Zhihong Nie, along with Professor Michael Rubinstein of the University of North Carolina. As polymer chemists, the team took an unconventional look at nanoparticle organization.

“We treated them as molecules, not particles, which in a process resembling a polymerization reaction, organize themselves into polymer-like assemblies,” says Kumacheva. “Using this analogy, we used the theory of polymerization and predicted the architecture of the so-called ‘molecules’ and also found other, unexpected features that can find interesting applications.”

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The findings were published in a report titled “Step-Growth Polymerization of Inorganic Nanoparticles” in the July 9 issue of Science. The research was funded with support from an NSERC Discovery Grant from the Natural Sciences and Engineering Research Council of Canada and Canada Research Chair funding.

February 26, 2010

Wii helps in stroke recovery

I have solar and nanotechnology release two-fers pretty often since both of those technologies pump out a lot of news. This is bit more rare — a Nintendo Wii two-fer. Here’s the first, and below you can find the second.

The release:

Wii™ video games may help stroke patients improve motor function

Abstract LB P4
Note: The Abstract will be presented at 5:30 p.m. CT

Study highlights:

  • The use of virtual reality Wii™ game technology holds the promise as a safe and feasible way to help patients recovering from stroke improve their motor function.
  • Researchers said it’s too early to recommend it as standard stroke rehabilitative therapy.

American Stroke Association meeting report:
SAN ANTONIO, Feb. 25, 2010 — Virtual reality game technology using Wii™ may help recovering stroke patients improve their motor function, according to research presented as a late breaking poster at the American Stroke Association’s International Stroke Conference 2010.

The study found the virtual reality gaming system was safe and feasible strategy to improve motor function after stroke.

“This is the first randomized clinical study showing that virtual reality using Wii™ gaming technology is feasible and safe and is potentially effective in enhancing motor function following a stroke, but our study results need to be confirmed in a major clinical trial,” said Gustavo Saposnik, M.D., M.Sc., director of the Stroke Outcomes Research Unit at the Li Ka Shing Institute, St. Michael’s Hospital and lead investigator of the study carried out at the Toronto Rehabilitation Institute at the University of Toronto, Canada.

The pilot study focused on movements with survivors’ impaired arms to help both fine (small muscle) and gross (large muscle) motor function.

Twenty survivors (average age 61) of mild to moderate ischemic or hemorrhagic strokes were randomized to playing recreational games (cards or Jenga, a block stacking and balancing game) or Wii™ tennis and Wii™ Cooking Mama, which uses movements that simulate cutting a potato, peeling an onion, slicing meat and shredding cheese.

Both groups received an intensive program of eight sessions, about 60 minutes each over two weeks, initiated about two months following a stroke.

The study found no adverse effects in the Wii™ group, reflecting safety. There was only one reported side effect in the recreational therapy group: nausea or dizziness. The Wii™ group used the technology for about 364 minutes in total session time, reflecting its feasibility. The recreational therapy group’s total time was 388 minutes.

“The beauty of virtual reality is that it applies the concept of repetitive tasks, high-intensity tasks and task-specific activities, that activates special neurons (called ‘mirror neuron system’) involved in mechanisms of cortical reorganization (brain plasticity),” Saposnik said.  “Effective rehabilitation calls for applying these principles.”

Researchers found significant motor improvement in speed and extent of recovery with the Wii™ technology.

“Basically, we found that patients in the Wii™ group achieved a better motor function, both fine and gross, manifested by improvement in speed and grip strength,” Saposnik said. “But it is too early to recommend this approach generally. A larger, randomized study is needed and is underway.”

Wii™ is a virtual reality video gaming system using wireless controllers that interact with the user. A motion detection system allows patients their actions on a television screen with nearly real time sensory feedback.

Co-authors are Mark Bayley, M.D.; Muhammad Mamdani, Pharm.D.; Donna Cheung, O.T.; Kevin Thorpe, Mmath; Judith Hall, M.;Sc.; William McIlroy, Ph.D.; Jacqueline Willems; Robert Teasell, M.D.; and Leonardo G. Cohen, M.D.; for the Stroke Outcome Research Canada (SORCan) Working Group. Author disclosures are on the abstract.

The Effectiveness of Virtual Reality Using Wii Gaming Technology in Stroke Rehabilitation (EVREST) Study was funded by a grant from the Heart and Stroke Foundation (HSFO) and the Ontario Stroke System (OSS) in Canada.

Click here to download audio clips offering perspective on this research from American Stroke Association spokesperson, Pamela Duncan, Ph.D., PT, FAPTA, Professor and Bette Busch Maniscalico Research Fellow, Division of Physical Therapy, Department of Community and Family Medicine; Senior Fellow Duke Center for Clinical Health Policy Research, Duke University, Durham, N.C.

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Statements and conclusions of study authors that are presented at American Heart Association/American Stroke Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing science content. Revenues from pharmaceutical and device corporations are available atwww.americanheart.org/corporatefunding.

December 7, 2008

Stem cell transplantation news

The release from today:

Research Explores the Effects of Stem Cell Source and Patient Age on Stem Cell Transplantation Outcomes

SAN FRANCISCO, Dec. 7 /PRNewswire-USNewswire/ — Two studies examining the effects of stem cell source and patient age on stem cell transplantation outcomes will be explored at a press conference taking place on Sunday, December 7, at 8:00 a.m., during the 50th Annual Meeting of the American Society of Hematology in San Francisco, CA. Preliminary results from a study examining a specialized technique for increasing the presence of stem cells in cord blood for transplantation will also be shared during the press conference.

“For years, stem cell transplants have been a standard treatment option for many blood cancers and other hematologic conditions,” said Armand Keating, MD, moderator of the press conference and Director, Division of Hematology, and Professor of Medicine at the University of Toronto, Ontario, Canada. “The results of these studies add to the growing body of knowledge about the best regimens available to help produce durable responses and prolonged survival in many groups of patients.”

Blood cancers – leukemia, lymphoma, and myeloma – are typically treated with a combination of treatments including chemotherapy, biological therapy, radiation therapy, and stem cell transplantation. Stem cell transplantation is the process by which blood stem cells are collected from a donor, or from the patient prior to chemotherapy, and then infused into the patient after treatment. The transplanted stem cells travel to the bone marrow and begin to produce new blood cells, replacing those that are destroyed as a side effect of chemotherapy. Stem cell transplants are categorized by the source of the stem cells (bone marrow, peripheral blood, or cord blood) and by their origin – autologous (from the patient) or allogeneic (from a donor).

Effect of Stem Cell Source on Transplant Outcomes in Adults With Acute Leukemia: A Comparison of Unrelated Bone Marrow, Peripheral Blood, and Cord Blood [Abstract #151]

Mary Eapen, MBBS, the Center for International Blood and Marrow Transplantation along with the European Group for Blood and Marrow Transplantation and the New York Blood Center

In the absence of a matched sibling donor, the first choice for stem cell transplantation for patients with acute leukemia is an unrelated adult donor whose tissue type matches that of the patient. However, when such a donor is not available, the researchers of this study found that mismatched unrelated cord blood transplants were a suitable alternative to mismatched bone marrow or peripheral blood transplants because cord blood is readily available, making it an ideal option when transplantation is needed urgently.

For successful transplantation, bone marrow and peripheral blood donors are examined for genetic compatibility with the patient by comparing their human leukocyte antigens (HLAs). Current estimates from the National Marrow Donor Program donor registry suggest that the probability of finding a matched unrelated adult donor is relatively low (51 percent for Caucasians, 30 percent for Hispanics, 20 percent for Asians, and 17 percent for African Americans).

Cord blood donated to public cord blood banks can be an alternative source of stem cells for patients who need a transplant but cannot find a matched adult donor. The matching requirements for cord blood are not as strict as for bone marrow or peripheral blood because cord blood cells are immunologically immature and therefore more tolerant to mismatching.

The purpose of this study was to determine the efficacy of three types of stem cell sources: bone marrow, peripheral blood, and cord blood. Study results were based on an analysis of the outcomes of 1,240 adults with acute leukemia (707 patients with acute myeloid leukemia and 533 patients with acute lymphocytic leukemia) from 2002 to 2006. Of those patients who received a bone marrow stem cell transplant, 243 were matched at eight out of eight possible HLA loci and 111 were matched at seven HLA loci. In those receiving a peripheral blood stem cell transplant, 518 were matched at eight HLA loci and 210 at seven HLA loci. In those receiving cord blood transplants, 28 were matched at five or six HLA loci and 110 matched at four HLA loci.

The study found that there were fewer transplant-related deaths for matched peripheral blood and bone marrow transplants (27 percent and 26 percent, respectively) than as for mismatched peripheral blood, bone marrow, and cord blood transplants (42 percent, 37 percent, and 41 percent, respectively). Leukemia-free survival (LFS) and overall survival (OS) were highest after transplantation of matched peripheral blood (LFS: 43 percent; OS: 45 percent) and bone marrow (LFS: 46 percent; OS: 48 percent). These rates were lower after transplantation of mismatched peripheral blood (LFS: 33 percent; OS: 36 percent), bone marrow (LFS: 34 percent; OS: 38 percent), and cord blood (LFS: 33 percent; OS: 35 percent). Importantly, rates of transplant-related deaths, leukemia-free survival, and overall survival for the three types of mismatched transplants were similar even though cord blood transplants were mismatched at more HLA loci.

Notch-Mediated Expansion of Human Cord Blood Progenitor Cells Results in Rapid Myeloid Reconstitution in Vivo Following Myeloablative Cord Blood Transplantation

  [Abstract #212]
  Colleen Delaney, MD, Fred Hutchinson Cancer Research Center, Seattle, WA

This phase I study found that cord blood that is cultured to increase the number of CD34+ stem cells prior to transplantation helped to decrease the time to engraftment in patients with acute myeloid leukemia.

Cord blood is a valuable source of hematopoietic stem cells as it has a higher concentration of these cells than is normally found in adult blood. However, as only a small quantity of blood can typically be obtained from an umbilical cord, resulting in fewer available stem cells for transplantation, researchers have been investigating novel methods to expand the number of stem cells available from cord blood to help increase the success rates of cord blood stem cell transplants.

The objective of this study is to evaluate the safety and potential efficacy of giving increased numbers of cord blood progenitor cells that have been generated through a novel methodology whereby CD34+ cord blood progenitor cells are cultured prior to infusion to rapidly multiply in order to decrease the time required for the transplanted cells to engraft and begin production of healthy blood cells.

A total of six patients with acute myeloid leukemia were treated with a transplantation- preparation regimen of cytoxan (120 mg/kg), fludarabine (75 mg/m^2), and TBI (1320 cGy), followed one day later by an infusion of one unit of non-cultured cord blood and one unit of cord blood that had been CD34+ enriched and cultured for 16 days. The non-cultured unit was given to provide long-term repopulating stem cells that had not been previously manipulated, while the goal of the expanded unit was to provide cells capable of rapid myeloid recovery.

To achieve best results, cord blood units that most closely genetically matched the patient were selected for transfusion. All non-cultured cord blood stem cells were matched for four out of six alleles for each patient. For the cultured cord blood cells, two patients received a five-out-of-six allele match and four patients received a four-out-of-six allele match. There was an average CD34+ increase of 160 (range 41 to 382), meaning that for every one CD34+ cell, there were 160 CD34+ cells after the culture, with an average total nucleated cell fold increase of 660 (range 146 to 1496). A control group of 17 patients underwent an identical transplant regimen, but received two non-cultured cord blood units.

A relatively rapid engraftment time, averaging 14 days, was observed in the six patients in the experimental group compared with 25 days for the patients in the control group. The contribution of the expanded and non-cultured cord blood cells was determined by a DNA-based assay beginning seven days following the transplant. In the five patients with early engraftment, the engrafted cells present at day seven were derived almost entirely from the cultured unit. Persistent contribution to engraftment from the cultured cells was noted in two patients. One patient had persistent contribution from the cultured cells through 280 days post-transplant that was no longer noticeable at one year, and the second patient continued to demonstrate contribution from the cultured cells at 180 days post-transplant. One patient died on day 462 from a rare complication of myelitis (inflammation of the spinal cord) caused by the varicella-zoster virus, while all other patients were still in remission.

Non-Myeloablative Hematopoietic Stem Cell Transplantation in Older Patients With AML and MDS: Results From the Center for International Blood and Marrow Transplant Research (CIBMTR) [Abstract #346]

Sergio Giralt, MD, The University of Texas M. D. Anderson Cancer Center, Houston, TX

This study found that the outcomes of adults over the age of 65 undergoing allogeneic stem cell transplantation for the treatment of acute myeloid leukemia and myelodysplastic syndromes were similar to younger adults even after adjusting for multiple risk factors. The researchers concluded that age alone should not be a limiting factor for proceeding to allogeneic stem cell transplantation in these patients.

While stem cell transplantation remains one of the best treatment options for increasing overall survival and a possible cure for patients with acute myeloid leukemia and myelodysplastic syndromes, transplants generally are not given to patients over the age of 65 because of concerns about extreme toxicity and poor outcomes. Over the past few years, non-myeloablative transplants that require smaller and safer doses of chemotherapy and radiation have allowed stem cell transplants to be conducted in older individuals or other patients considered too weak to withstand conventional stem cell treatment regimens.

To better study age as a predictor of outcome in patients receiving stem cell transplants, data from the Center for International Blood and Marrow Transplant Research (CIBMTR) on 565 patients with acute myeloid leukemia and 551 patients with myelodysplastic syndromes were retrospectively analyzed for transplant-related mortality, engraftment, incidence of acute and chronic graft-versus-host disease, leukemia-free survival, and overall survival. Outcome data gathered from 1995 to 2005 were stratified into four groups by patient age for comparison: ages 40 to 54, 54 to 59, 60 to 64, and 65 and older.

The analysis found that there was no statistically significant difference in transplant-related mortality across age groups, and no overall difference in the occurrence of acute graft-versus-host disease (31-35 percent at 100 days) or chronic graft-versus-host disease (36-53 percent at two years). Rates of relapse were similar across all age groups (29-30 percent at three years). Additionally, no statistically significant impact of age was found for transplant-related mortality, leukemia-free survival, or overall survival. Type of disease and disease status at transplant were significant risk factors for leukemia-free survival and overall survival at one year and for transplant-related mortality and relapse at two years. Patients’ general health and degree of tissue-type match between recipient and donor were also significant at two years for nearly all outcomes.

American Society of Hematology 50th Annual Meeting

The study authors and press program moderator will be available for interviews after the press conference or by telephone. Additional press briefings will take place throughout the meeting on combating blood clots, therapeutic strategies for platelet disorders, treatment advances in leukemia and lymphoma, and advances in screening and treatment for sickle cell disease.

The American Society of Hematology (www.hematology.org) is the world’s largest professional society concerned with the causes and treatment of blood disorders. Its mission is to further the understanding, diagnosis, treatment, and prevention of disorders affecting blood, bone marrow, and the immunologic, hemostatic, and vascular systems, by promoting research, clinical care, education, training, and advocacy in hematology. In September, ASH launched Blood: The Vital Connection (www.bloodthevitalconnection.org), a credible online resource addressing bleeding and clotting disorders, anemia, and cancer. It provides hematologist-approved information about these common blood conditions including risk factors, preventive measures, and treatment options. A cornerstone of this public awareness campaign is a new documentary by award-winning filmmaker Joseph Lovett called “Blood Detectives,” which will air on the Discovery Health cable network on December 19, 2008, at 7:00 p.m. ET/PT and again at 12:00 midnight. The show focuses on hematologists as they work to unravel medical mysteries and save lives.

Source: American Society of Hematology
   

Web Site:  http://www.bloodthevitalconnection.org/

September 30, 2008

Got a sticky problem? Get distracted

Looks like distractions may be a good thing.

The release:

Eureka! How distractions facilitate creative problem-solving

How many times have you spent hours slaving over an impossible problem, only to take a break and then easily solve the problem, sometimes within minutes of looking at it again? Although this is actually a common phenomenon, up until now the way that this occurs has been unclear. But new research in the September issue of Psychological Science, a journal of the Association for Psychological Science, demonstrates the answer is more complex than simply having an “Aha!” moment.

The new research, led in part by Kellogg School of Management Professor Adam Galinsky, suggests that unconscious thought results in creative problem-solving via a two-step process.

According to Galinsky and fellow psychologists Chen-Bo Zhong from the University of Toronto and Ap Dijkstererhuis of Radboud University Nijmegen, distractions may be helpful in coming up with creative solutions to a certain problem, but must be followed by a period of conscious thought to ensure that we are aware of those solutions and can apply them. Likewise, while distractions are more useful in solving difficult problems, it may be better to stay focused on finding the solution when confronted with easier problems.

The researchers conducted two experiments to test their idea. In the first experiment, 94 subjects participated in a Remote-Association Test (RAT), which tests for creativity. In this test, participants were presented with three words (a triad) and were asked to come up with a fourth word that is linked with all three words. For example, if presented with the words cheese, sky and ocean, the correct answer would be blue (blue cheese, blue sky, blue ocean). Subjects were shown nine very difficult triads (but were instructed not to solve them yet) and were then divided into groups. For five minutes following the RAT, participants were either concentrating on the triads they had just seen (the conscious thought group) or engaging in a test completely unrelated to the RAT (the unconscious thought group). Following the five-minute interval, all of the subjects participated in a lexical decision test. During this test, subjects were shown sequences of letters and had to indicate as quickly as possible if the sequences were English words or not. The sequences presented included answers to the RAT triads, random words and non-words. Finally, subjects were again shown the RAT items and had to write down their answers.

The second experiment involved 36 subjects and had a similar set up to the previous experiment, although the RAT triads presented were much easier to solve compared to those in the first experiment.

The results showed that in the first experiment, during the lexical decision test, members of the unconscious thought group had much faster responses to letter sequences which were answers to RAT items, compared to the conscious thought group. However, when it came time to solve the RAT problems, both groups had similar results. In the second experiment (using an easier set of RAT triads), the conscious thought group had more correct RAT answers compared to the unconscious thought group, but there was no difference in response time during the lexical decision test.

“Conscious thought is better at making linear, analytic decisions, but unconscious thought is especially effective at solving complex problems,” said Galinsky and his co-authors. “Unconscious activation may provide inspirational sparks underlying the ‘Aha!’ moment that eventually leads to important discoveries.”

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September 22, 2008

Photo of an extrasolar planet?

Filed under: Media, Science — Tags: , , , — David Kirkpatrick @ 12:56 pm

From KurzweilAI.net — Did University of Toronto astronomers capture an image of an extrasolar planet? You be the judge.

A Maybe Planet, Orbiting Its Maybe Sun
New York Times, Sep. 18, 2008

Astronomers from the University of Toronto have published a picture of what they say might be the first image of a planet orbiting another Sunlike star, about 30 billion miles away from the star, inexplicably.


(Gemini Observatory)
 
Read Original Article>>

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