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pengertian solar cells

Why and How To Choose a Professional Solar Panel Installer

Renewable Energy Centre specialise in solar energy and renewable energy,

Bark-Scoring Tools To Repair Tree Grafts - US Forest Service

G rafted seed orchards of Douglas-fir are often subject to tree losses caused by delayed graft incompatibility. When the stock and scion (the grafted branch) are incompatible, the stock and scion wall off the foreign cells with a separation zone of dead, suberized (corky) tissue. The separation zone is termed “brownline.” This response occurs along the entire interface in the bark cells of both the stock and scion. This type of graft failure is the product of the defense mechanisms of each tree. The same process enables trees to wall off invading insects and disease organisms or to cover physical wounds with an impervious or protective covering. If a graft becomes incompatible several years after grafting, seed production will be lost and genetic variability will be decreased. A number of years will be required to replace the incompatible grafts. Improving the long-term survival and performance of established grafts is difficult.

7 Useful Tips to Opt For Solar Pool Heating Services

Do you have a pool in your very own backyard? Is it a tough task for you or you don’t have time to maintain and clean the pool area? If yes, then opt for the best pool maintenance firm in Melbourne. It is important that you hire a firm, which is reliable, reputable and affordable. This article provides you some immensely useful tips to hire the best professionals for this purpose.

Cardiac Stem Cell Therapy and the Promise of Heart Regeneration

Perspective Cardiac Stem Cell Therapy and the Promise of Heart Regeneration Jessica C. Garbern1 and Richard T. Lee2,* 1Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA Stem Cell Institute, the Brigham Regenerative Medicine Center and the Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA *Correspondence: rlee@partners.org http://dx.doi.org/10.1016/j.stem.2013.05.008 2Harvard Stem cell therapy for cardiac disease is an exciting but highly controversial research area. Strategies such as cell transplantation and reprogramming have demonstrated both intriguing and sobering results. Yet as clinical trials proceed, our incomplete understanding of stem cell behavior is made evident by numerous unresolved matters, such as the mechanisms of cardiomyocyte turnover or the optimal therapeutic strategies to achieve clinical efficacy. In this Perspective, we consider how cardiac stem cell biology has led us into clinical trials, and we suggest that achieving true cardiac regeneration in patients may ultimately require resolution of critical controversies in experimental cardiac regeneration. Introduction The race is on: throughout the world, basic and clinical investigators want to be the first to identify new approaches to regenerate cardiac tissue and to prove the effects of these therapies in patients with heart disease. Despite substantial progress in treating many types of heart disease, the worldwide heart failure burden will remain enormous through this century. The potential of stem cells and the scope of the heart failure problem have fueled a stampede to be the first to achieve human heart regeneration. Cell transplantation approaches are attractive given their...

Stem cell therapy is helping horses with tendon and ... - Vet-Stem

Ultrasound is used to precisely guide the injection of adipose-derived stem cells into the suspensory ligament. The still-developing technology of stem cell therapy, which uses unspecified cells from the horse’s body, has the potential to help racehorses heal sounder than ever before. A tendon is a bundle of elastic fibers, mostly made of collagen, that attaches muscle to bone and helps move the skeleton. Ligaments are similar but attach bone to bone and provide stability. When a horse bows a tendon, it tears the fibers at a certain point of the tendon (the location results in a name, such as high or low bow), weakening it significantly. When the tendon begins to knit back together, it is significantly hampered by lack of blood flow. Blood provides several healing mechanisms, including adult stem cells, which are able to convert themselves into specific types of cells the body needs to heal itself (in this case, tendon cells). If the tendon does not get enough help, it eventually develops scar tissue, which weakens the tendon because it is nonelastic and haphazardly knitted together. The injury takes a long time to heal – a typical racetrack cure was pinfiring or blistering, followed by six months to a year of turnout. If a horse was brought back to the track and the tendon had mostly healed with scar tissue, the weakened tendon could give way and the injury recur.

Stem Cell Treatments For Cerebral Palsy Factsheet For - UCLA ...

STEM CELLS AND CEREBRAL PALSY Cerebral palsy (CP) is an umbrella term which includes several forms and levels of nonprogressive brain-related injury, which cause limitations in muscle control, movement and mobility (known as neuromotor impairment) and other symptoms that lead to physical disability. CP is caused by many factors, and can include infection before birth, premature birth and lack of oxygen around the time of birth. It is thought that the major common feature in CP is a lack of blood and oxygen to the brain during fetal development and/or delivery, known as a hypoxic-ischemic insult. The cells most vulnerable to this hypoxic-ischemic insult are oligodendrocytes, the support cells that wrap nerve cells (or neurons) with a protective white fat called myelin, hence the term white matter of the brain. Because of this myelin, neurons can send electrical signals efficiently throughout the body. Once oligodendrocytes die, the neurons are no longer protected and they eventually die. If myelin could be replaced before neurons die, neurons could be spared and motor impairments could be lessened. For this reason, scientists are investigating whether lost oligodendrocytes can be replaced with stem cells. Stem cells are unspecialized cells which can become specialized cells such as brain cells, heart cells or muscle cells. The process of developing into a specialized cell is known as differentiation. Stem cells can also multiply over and over again, a process known as proliferation. During the process of proliferation the stem cell either remains unspecialized or, under the right condition, can become a specialized cell such as a brain cell. Replacing neurons themselves would be like trying to rewire a giant switchboard with tens of thousands of ports but no labels, where improper connections could lead to pain. It is for this reason that the aim of many cell transplantation strategies now being tested is to replace lost oligodendrocytes rather than to make and successfully connect new neurons. Recent decades have seen advances in our knowledge of how to study and use stem cells. It is expected we will develop ways to transplant stem cells into damaged tissues to treat and cure injury and diseases like CP. From Mice to Humans...

Patient Handbook on Stem Cell Therapies - A Closer Look at Stem ...

W e have all heard about the extraordinary promise that stem cell research holds for the treatment of a wide range of diseases and conditions. However, there is a lot of work still needed to take this research and turn it into safe and effective treatments. The International Society for Stem Cell Research (ISSCR) is very concerned that stem cell therapies are being sold around the world before they have been proven safe and effective. Stem cell therapies are nearly all new and experimental. In these early stages, they may not work, and there may be downsides. Make sure you understand what to look out for before considering a stem cell therapy. Remember, most medical discoveries are based on years of research performed at universities and companies. There is a long process that shows first in laboratory studies and then in clinical research that something is safe and will work. Like a new drug, stem cell therapies must be assessed and meet certain standards before receiving approval from national regulatory bodies to be used to treat people. What does this really mean for you as a patient, doctor, friend or family member? Below we hope to answer some of your questions on stem cells and stem cell therapies and give you the resources you and your doctor need to make the best decisions possible for treatment. The ISSCR is a non-profit professional stem cell research organization with a commitment to ensure the promise of stem cell research is delivered to patients in a safe, effective and fair manner.

Stem cell therapy in a caprine model of osteoarthritis - Wiley Online ...

Stem Cell Therapy in a Caprine Model of Osteoarthritis J. Mary Murphy,1 David J. Fink,1 Ernst B. Hunziker,2 and Frank P. Barry1 Objective. To explore the role that implanted mesenchymal stem cells may play in tissue repair or regeneration of the injured joint, by delivery of an autologous preparation of stem cells to caprine knee joints following induction of osteoarthritis (OA). Methods. Adult stem cells were isolated from caprine bone marrow, expanded in culture, and transduced to express green fluorescent protein. OA was induced unilaterally in the knee joint of donor animals by complete excision of the medial meniscus and resection of the anterior cruciate ligament. After 6 weeks, a single dose of 10 million autologous cells suspended in a dilute solution of sodium hyaluronan was delivered to the injured knee by direct intraarticular injection. Control animals received sodium hyaluronan alone. Results. In cell-treated joints, there was evidence of marked regeneration of the medial meniscus, and implanted cells were detected in the newly formed tissue. Degeneration of the articular cartilage, osteophytic remodeling, and subchondral sclerosis were reduced in cell-treated joints compared with joints treated with vehicle alone without cells. There was no evidence of repair of the ligament in any of the joints. Conclusion. Local delivery of adult mesenchymal stem cells to injured joints stimulates regeneration of meniscal tissue and retards the progressive destruction normally seen in this model of OA.

Study shows stem cell therapy using a patient's own bone marrow ...

TIME study mirrors Late TIME trial in confirming autologous stem cells obtained from bone marrow are safe but do not further improve the recovery of heart function following a heart attack MINNEAPOLIS, MN – November 6, 2012 – Administering autologous stem cells obtained from bone marrow either 3 or 7 days following a heart attack did not improve heart function six months later, reports a new clinical trial supported by the National Institutes of Health. The results of this trial, called TIME (Transplantation In Myocardial Infarction Evaluation), were presented by Jay Traverse, MD of the Minneapolis Heart Institute Foundation Tuesday, Nov. 6, at the 2012 Scientific Sessions of the American Heart Association in Los Angeles. The results of this trial mirror a previous, related study (LateTIME) which found that autologous bone marrow stem cell therapy given 2-3 weeks after a heart attack did not improve cardiac recovery. Both TIME and LateTIME were carried out by the Cardiovascular Cell Therapy Research Network (CCTRN), sponsored by the NIH’s National Heart, Lung, and Blood Institute. “The data presented by TIME do much to advance stem cell therapy research,” said Jay Traverse, MD of the Minneapolis Heart Institute Foundation and Principal Investigator of this study. “While this study did not provide a demonstrated cardiac benefit after six months, we still learned a great deal. Together, TIME and Late TIME have shown that stem cell therapy is safe, and they have set a baseline in terms of quantity of stem cells, type of stem cells, and severity of heart attack.” TIME enrolled 120 volunteers (avg. age 57) between July 2008 and February 2011; the participants all had moderate to severe impairment in their left ventricle and had undergone coronary stent placement as treatment for the heart attack. The participants were randomly assigned to one of four groups: day 3 stem cell, day 3 placebo (inactive cells), day 7 stem cell, or day 7 placebo. The CCTRN researchers developed a method of processing and purifying the stem cells from the bone marrow of each volunteer to ensure everyone received a uniform dose (150 million stem cells)...

Overestimated global warming over the past 20 years

G lobal mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade (95% confidence interval)1. This rate of warming is significantly slower than that simulated by the climate models participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). To illustrate this, we considered trends in global mean surface temperature computed from 117 simulations of the climate by 37 CMIP5 models (see Supplementary Information). These models generally simulate natural variability — including that associated with the El Niño–Southern Oscillation and explosive volcanic eruptions — as well as estimate the combined response of climate to changes in greenhouse gas concentrations, aerosol abundance (of sulphate, black carbon and organic carbon, for example), ozone concentrations (tropospheric and stratospheric), land use (for example, deforestation) and solar variability. By averaging simulated temperatures only at locations where corresponding observations exist, we find an average simulated rise in global mean surface temperature of 0.30 ± 0.02 °C per decade (using 95% confidence intervals on the model average). The observed rate of warming given above is less than half of this simulated rate, and only a few simulations provide warming trends within the range of observational uncertainty (Fig. 1a). The inconsistency between observed and simulated global warming is even more striking for temperature trends computed over the past fifteen years (1998–2012). For this period, the observed trend of 0.05 ± 0.08 °C per decade is more than four times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade (Fig. 1b). It is worth noting that the observed trend over this period — not significantly...

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