ACS Chemistry for Life

Boom in fracking for oil and gas recovery sparks new technology
Chemical & Engineering News

C&EN Senior Business Editor Melody M. Bomgardner explains that fracking or hydraulic fracturing involves pumping massive amounts of grainy substances, called proppants, down oil or natural gas wells. Proppants enable production from rock formations 10,000 or 20,000 feet below the surface. To access the oil and gas in these deposits, they need to be fractured open with a mixture of fluid and proppants pumped down wells under high pressure. The grains literally prop up the fissures in these rocks so that oil and gas can flow to the surface. The article describes development of a new genre of proppants to meet the needs of today’s drillers. For wells that reach more than a mile down, drillers may need 10 million to 20 million pounds of proppants to get oil or natural gas flowing.

New Saudi Arabias of solar energy: Himalaya Mountains, Andes, Antarctica
Environmental Science & Technology

Kotaro Kawajiri and colleagues explain that the potential for generating electricity with renewable solar energy depends heavily on geographic location. Arid and semi-arid areas with plenty of sunshine long have been recognized as good solar sites. However, the scientists point out that, as a result of the limited data available for critical weather-related conditions on a global scale, gaps still exist in knowledge about the best geographical locations for producing solar energy. To expand that knowledge, they used one established technique, which takes into account the effects of temperature on the output of solar cells, to estimate global solar energy potential using the data that are available. They found that many cold regions at high elevations receive a lot of sunlight – so much so that their potential for producing power from the sun is even higher than in some desert areas. Kawajiri and colleagues found, for instance, that the Himalayas, which include Mt. Everest, could be an ideal locale for solar fields that generate electricity for the fast-expanding economy of the People’s Republic of China.

From the ancient Amazonian Indians: A modern weapon against global warming
Environmental Science & Technology

Kelli Roberts and colleagues report that “biochar” – a material that the Amazonian Indians used to enhance soil fertility centuries ago – is charcoal produced by heating wood, grass, cornstalks or other organic matter in the absence of oxygen. The heat drives off gases that can be collected and burned to produce energy. It leaves behind charcoal rich in carbon. Mass production of biochar could capture and sock away carbon that otherwise would wind up in the atmosphere as carbon dioxide, the main greenhouse gas. The study involved a “life-cycle analysis” of biochar production, a comprehensive cradle-to-grave look at its potential in fighting global climate change and all the possible consequences of using the material. It concludes that several biochar production systems have the potential for being an economically viable way of sequestering carbon – permanently storing it – while producing it.

Getting plants to rid themselves of pesticide residues
Journal of Agricultural and Food Chemistry

Jing Quan Yu and colleagues have discovered that a type of natural plant hormone — brassinosteroids (BRs) — applied to crops, can help plants eliminate residues of certain pesticides. Farmers worldwide use about 2.5 million tons of pesticides each year. The scientists treated cucumber plants with one type of BR then treated the plants with various pesticides, including chloropyrifos (CPF), a broad-spectrum commercial insecticide. BR significantly reduced their toxicity and residues in the plants, they say. BRs may be “promising, environmentally friendly, natural substances suitable for wide application to reduce the risks of human and environmental exposure to pesticides,” the scientists note. The substances do not appear to be harmful to people or other animals, they add.

School classroom air may be more polluted with ultrafine particles than outdoor air
Environmental Science & Technology

Lidia Morawska and colleagues are reporting that the air in some school classrooms may contain higher levels of extremely small particles of pollutants – easily inhaled deep into the lungs – than polluted outdoor air. Evidence suggests that airborne ultrafine particles can be toxic when inhaled into the lungs. Much of the scientific research, however, has focused on outdoor sources of these invisible particles, but little research has been done on indoor sources, and even less on ultrafine particles in school classrooms. In an effort to fill those gaps in knowledge, the scientists studied levels of ultrafine particles in 3 elementary school classrooms in Brisbane, Australia. The highest levels of ultrafine particle levels occurred during art activities such as gluing, painting and drawing when indoor levels were several times higher than outdoor levels. There also were significant increases in ultrafine particle levels when detergents were used for cleaning.

Improving China’s acid rain control strategy
Environmental Science & Technology

Lei Duan and colleagues are reporting the first evidence that China’s sharp focus on reducing widespread damage to soil by acid rain by restricting sulfur dioxide air pollution may have an unexpected consequence: Gains from that pollution control program will be largely offset by increases in nitrogen emissions, which the country’s current policy largely overlooks. China is trying to stop soil acidification by reducing sulfur dioxide pollution from electric power plant smokestacks. China is striving for a 10 percent reduction in sulfur dioxide emissions by 2010, a policy that seems to have had only a limited impact so far, the researchers say. However, China has paid little attention to pollution from nitrogen oxides, which also contribute to acid rain and soil contamination. The scientists’ analysis found that the benefits of sulfur dioxide reductions will almost be offset by increased nitrogen emissions. To control this problem, “China needs a multipollutant control strategy that integrates measures to reduce sulfur, nitrogen, and particulate matter,” the article notes.

Glacial melting may release pollutants in the environment
Environmental Science & Technology

Those pristine-looking Alpine glaciers now melting as global warming sets in may explain the mysterious increase in persistent organic pollutants in sediment from certain lakes since the 1990s, despite decreased use of those compounds in pesticides, electric equipment, paints and other products. In the study, Christian Bogdal and colleagues focused on organic pollutants in sediment from a model body of water – glacier-fed Lake Oberaar in the Bernese Alps, Switzerland – testing for the persistent organic pollutants, including dioxins, PCBs, organochlorine pesticides and synthetic musk fragrances. They found that while contamination decreased to low levels in the 1980s and 1990s due to tougher regulations and improvements in products, since the late 1990s flow of all of these pollutants into the lake has increased sharply. Currently, the flow of organochlorines into the lake is similar to or even higher than in the 1960s and 1970s, the report states. The study attributed the most recent spike in the flow of pollutants into Lake Oberaar to the accelerated release of organic chemicals from melting Alpine glaciers, where contaminants were deposited earlier and preserved over decades.

An inexpensive “dipstick” test for pesticides in foods
Analytical Chemistry

John Brennan and colleagues are reporting the development of a fast, inexpensive “dipstick” test to identify small amounts of pesticides that may exist in foods and beverages. Their paper-strip test is more practical than conventional pesticide tests, producing results in minutes rather than hours by means of an easy-to-read color-change, they say. They cite a growing need for cheaper, more convenient, and more eco-friendly tests for pesticides, particularly in the food industry. The scientists describe the development of a new paper-based test strip that changes color shades depending on the amount of pesticide present. In laboratory studies using food and beverage samples intentionally contaminated with common pesticides, the test strips accurately identified minute amounts of pesticides. The test strips, which produced results in less than 5 minutes, could be particularly useful in developing countries or remote areas that may lack access to expensive testing equipment and electricity, they note.

New material for air cleaner filters that captures flu viruses
Biomacromolecules

Xuebing Li, Peixing Wu and colleagues are reporting development of a new material for the fiber in face masks, air conditioning filters and air cleaning filters that captures influenza viruses before they can get into people’s eyes, noses and mouths and cause infection. In an average year, influenza kills almost 300,000 people and sickens millions more worldwide. The constant emergence of new strains of virus that shrug off vaccines and anti-influenza medications has led to an urgent need for new ways of battling this modern-day scourge. So Li, Wu and colleagues sought a new approach, using a substance termed chitosan made from ground shrimp shells. The scientists combined chitosan with substances that the flu virus attaches to in order to infect cells. They found this new version of chitosan, ideal for attaching to fibers of face masks and air filters, was highly effective in capturing flu virus.

Advance toward a breath test to diagnose multiple sclerosis
ACS Chemical Neuroscience

Hossam Haick and colleagues are reporting the development and successful tests in humans of a sensor array that can diagnose multiple sclerosis (MS) from exhaled breath, an advance that they describe as a landmark in the long search for a fast, inexpensive and non-invasive test for MS – the most common neurological disease in young adults. Currently, doctors diagnose MS based on its characteristic symptoms, which include muscle spasms, numbness, coordination problems and slurred speech. Common tools for confirming the diagnosis and making informed decisions on treatment are magnetic resonance imaging (MRI) of the brain, or a lumbar puncture or “spinal tap” to analyze the fluid that bathes the brain and spinal cord. But MRI scans are costly, and lumbar punctures are invasive. To overcome these obstacles, the researchers have identified volatile organic compounds that can be associated with MS from exhaled breath, and developed a new sensor array that can diagnose MS. Using the developed sensors, the researchers carried out a proof-of-concept clinical study on 34 MS patients and 17 healthy volunteers and found that the developed sensors are just as accurate as a spinal tap but without the pain or the risk of side effects.

A better imaging agent for heart disease and breast cancer
Journal of the American Chemical Society

Taeghwan Hyeon, Seung Hong Choi, and colleagues are reporting development of a process for producing large quantities of tantalum oxide nanoparticles, a much-needed new imaging agent for computed tomography (CT) scans in heart disease, breast cancer and other diseases, and the first evidence that the material is safe for clinical use. Today’s imaging agents have many disadvantages. They don’t stay in the body for very long, for instance, limiting the types of images that physicians can obtain. Nanoparticles have been developed as imaging agents, but they have been made of either gold (very expensive) or bismuth (toxic). The researchers describe development and successful initial tests of large batches of tantalum oxide nanoparticles that exhibited “remarkable performances” in imaging tests of the heart, lymph nodes, kidneys, and other structures in laboratory rats, which are stand-ins for humans in such research. Regarding safety, they say, “The nanoparticles did not affect normal functioning of organs.”

New test shows promise for detecting warning signs of joint replacement failure
Molecular Pharmaceutics

A new test shows promise for detecting the early stages of a major cause of failure in joint replacement implants, so that patients can be treated and perhaps avoid additional surgery. Dong Wang and colleagues at University of Nebraska Medical Center and the Hospital for Special Surgery of New York explain that wear and tear in a joint replacement can create tiny bits of debris that cause local inflammation and lead to bone loss, eventually making the implant loose. Treatment usually comes too late, since it’s difficult to detect the problem in its early stages. To provide an early diagnostic tool for implant failure, the researchers developed a polymer-based system for imaging the inflammation that is associated with the wear debris. Their tests of the imaging agent in mouse bone suggest that it can help them detect the early stages of bone loss that might cause a joint implant to become loose. They also found that they could tether a powerful anti-inflammatory drug to the polymeric system, offering a way to treat inflammation and bone loss in these early stages of wear.

Toward a vaccine for methamphetamine abuse
Journal of the American Chemical Society

Kim Janda and colleagues are reporting development of three promising formulations that could be used in a vaccine to treat methamphetamine addiction – one of the most serious drug abuse problems in the U.S. Methamphetamine use and addiction cost the U.S. more than $23 billion annually due to medical and law enforcement expenses, as well as lost productivity. The drug, also called “meth” or “crystal meth,” can cause a variety of problems including cardiovascular damage and death. Meth is highly addictive, and users in conventional behavioral treatment programs often relapse. Previously tested meth vaccines either are not effective or are very expensive. To overcome these challenges, the researchers made and tested new vaccine formulations that could potentially be effective for long periods, which would drive down costs and help prevent relapse.

Natural protection against radiation
ACS Medicinal Chemistry Letters

In the midst of ongoing concerns about radiation exposure from the Fukushima nuclear power plant in Japan, scientists are reporting that a substance similar to resveratrol – an antioxidant found in red wine, grapes and nuts – could protect against radiation sickness. Michael Epperly, Kazunori Koide and colleagues explain that radiation exposure, either from accidents (like recent events in Japan) or from radiation therapy for cancer, can make people sick or die. The U.S. Food and Drug Administration is currently evaluating a drug for its ability to protect against radiation sickness, but it is difficult to make in large amounts, and the drug has side-effects that prevent its use for cancer patients. To overcome these disadvantages, the researchers studied whether resveratrol – a natural and healthful antioxidant found in many foods – could protect against radiation injuries. They found that resveratrol protected cells in flasks but did not protect mice (stand-ins for humans in the laboratory) from radiation damage. However, the similar natural product called acetyl resveratrol did protect the irradiated mice, and can be produced easily in large quantities and given orally. The authors caution that it has not yet been determined whether acetyl resveratrol is effective when orally administered.

Artificial leaf could debut new era of “fast-food energy”
Chemical & Engineering News

Technology for making an “artificial leaf” holds the potential for opening an era of “fast-food energy,” in which people generate their own electricity at home with low-cost equipment perfect for the 3 billion people living in developing countries and even home-owners in the United States. C&EN Senior Correspondent Stephen K. Ritter describes research on electrofuels, made by using energy from the sun and renewable ingredients like water and carbon dioxide, reported at a gathering of experts sponsored by the U.S. Department of Energy’s Advanced Research Projects Agency (ARPA-E). Created in 2009 by the American Recovery & Reinvestment Act, ARPA-E is funding electrofuels research, with the goal of developing technologies that improve on nature’s approach – photosynthesis. The artificial leaf, made of inexpensive materials, is one of the electrofuels technologies, which breaks down ordinary water into the oxygen and hydrogen that can power an electricity-producing fuel cell. Just drop the credit-card-sized device into a bucket of water and expose it to sunlight. With the cost-conscious technology, one door-sized solar cell and three gallons of water could produce a day’s worth of electricity for a typical American home.

Cotton fabric cleans itself when exposed to ordinary sunlight
ACS Applied Materials & Interfaces

Scientists are reporting development of a new cotton fabric that does clean itself of stains and bacteria when exposed to ordinary sunlight. Mingce Long and Deyong Wu say their fabric uses a coating made from a compound of titanium dioxide, the white material used in everything from white paint to foods to sunscreen lotions, and nitrogen. Titanium dioxide breaks down dirt and kills microbes when exposed to some types of light. It already has found uses in self-cleaning windows, kitchen and bathroom tiles, odor-free socks and other products. Self-cleaning cotton fabrics have been made in the past, the authors note, but they self-clean thoroughly only when exposed to ultraviolet rays. They show that fabric coated with the material removes an orange dye stain when exposed to sunlight.