Investigación

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Researchers study genes of Chilean native yeasts to optimize wine fermentation

Researchers study genes of Chilean native yeasts to optimize wine fermentation

  • The Regular Fondecyt Project “Mapping underlying genetic variants in nitrogen assimilation in different natural yeasts” led by Dr Claudio Martínez, researcher at the Food Science and Technology Research Center of Universidad de Santiago, proposes a new wine fermentation method that will not depend on nitrogen levels in the must. The study will last until 2019 and it involves the participation of researchers at the Department of Food Science and Technology of Universidad de Santiago and foreign experts from the CNRS in Nice (France) and the Instituto de Agroquímica y Tecnología de Alimentos in Valencia (Spain).

Yeasts are essential for wine fermentation as they turn grape sugar into alcohol. However, current industrial yeasts do not guarantee the completion of the fermentation process, resulting in economic losses for the national wine-making industry.

“It is estimated that about 40 per cent of the fermentation processes are interrupted, with a very strong impact on the industry. If you interrupt the process, thousands of litres will not ferment, so you need to spend more money to complete the process by adding more yeast or nutrients. This affects the wine properties and the quality expected,” Dr Claudio Martínez, director of the Food Science and Technology Research Center of Universidad de Santiago (Cecta, in Spanish), said.

To solve this problem, Dr Martínez and researchers at Universidad de Santiago are currently conducting the Regular Fondecyt Project “Mapping underlying genetic variants in nitrogen assimilation in different natural yeasts,” that will last until 2019.

“For yeasts to develop and work well, the abundant presence of some nutrients, like nitrogen, is required. As some musts have low levels of nitrogen, yeasts there do not grow well and the resulting product is not good. We will study the genes of Chilean native yeasts and foreign yeasts, searching for the ones that allow the yeast to assimilate nitrogen without considering its levels, and ferment the must efficiently,” he explained.

The yeasts described have been collected by the researchers at Cecta during the past decade, what allowed obtaining the most complete yeast strain collection of the country. With this register and through a previous Fondef Project, the Cecta developed a yeast strain, Fermicru XL, which has already been patented and commercialized worldwide.

“This new study has the purpose of identifying the genes with the features previously described to genetically improve industrial yeasts, something that has not been done before in Chile. First, we will search for the genes with the features we want in native yeasts and then, we will enhance an industrial strain, without using transgenic techniques,” he said.

The project will have the collaboration of Dr Amparo Querol of the Instituto de Agroquímica y Tecnología de Alimentos (IATA), in Valencia, Spain and Dr Gianni Liti, of the National Center for Scientific Research, (CNRS, in French), in Nice, France. Both centers will work on the genetic enhancement of yeast and the development of procedures for genetic investigation. Besides, they will allow access to their own collections of yeast native strains.

“They have yeast strains that they have collected from all over the world, representing more than 70 per cent of the world’s genetic varieties of yeasts. This is a very important genetic source that we will have available when conducting our study,” he added.

Dr Angélica Ganga, professor at the Department of Food Science and Technology; Dr Francisco Cubillos, researcher at Cecta; Dr Álvaro Díaz, of Universidad Católica de Valparaíso; and Dr Cristián Araneda, of Universidad de Chile, will also be part of the research team.

“It is important to study native yeasts. We assume that they have adapted to some environmental factors, so their properties can be potential solutions for the industry. This opportunity to study them allows us to progress in solving some issues, to develop genetic enhancement, and if everything goes as expected, to patent future yeasts based on native strains of our country,” Dr Martínez concluded.

Translated by Marcela Contreras

 

Researcher at Universidad de Santiago developed a new immunotherapy for cancer

Researcher at Universidad de Santiago developed a new immunotherapy for cancer

  • The new therapy involves the development of a vaccine that provides the immune system with the tools needed to “attack” cancer cells, improving the antitumour response of the body. The therapy was announced to foreign media correspondents accredited in Chile.

  • The study is funded through a Fondecyt Project and it is at preclinical stage. It considers a significant decrease of more than 70% in the overall cost of therapies for this disease.
  • The leader of the project, Claudio Acuña, Dr in Biomedical Sciences, researcher, and Head of the Department of Biology of our University, gave us some details on this new technology, which is applying for a patent in USA with the support of Corfo.
  • Dr Acuña said: “We are generating a quite effective therapy for cancer through which we could make immunotherapy more available to people. We are doing this in a university which is known for its social responsibility signature. In this context, I would like to highlight the talent of my students involved in this project.”

 

In order to optimize cancer therapy and contribute to public health in our country, an innovative and significant treatment developed at Universidad de Santiago has recently been presented.

This project involves the development of a vaccine that will allow destroying cancer cells in the body by enhancing its immune response.

This scientific development- funded by the National Fund for Scientific and Technological Development, Fondecyt- considers a significant decrease of more than 70% in the overall costs of cancer therapies and it has shown an efficacy of 50%.

Dr Claudio Acuña, Head of the Department of Biology of Universidad de Santiago, is leading the project. “We want to have a vaccine available to protect us from the disease, just like in the vaccination process for measles and other diseases when we are children. In the case of cancer, our idea is to get people vaccinated so that they are able to eliminate cancer cell in their bodies, he said.”

Quality of life

According to the researcher, the project “Seeks to improve the quality of life of patients in the long term and generate a supplementary therapy to conventional treatments to resist cancer in a non-conventional way, which is currently treated with chemotherapy.”

“We have completed the preclinical stage (trials in living animals) which showed that the vaccine does protect from the disease. The next step is the clinical phase, in which it will be tested in human subjects. There was not any negative effect on animals, so we could extrapolate that there will be not any effect on patients,” he added.

“The ultimate goal is to generate a vaccine for people with cancer that will allow enhancing their immune response to tumours,” he said.

We are generating a quite effective therapy for cancer in which we could make immunotherapy more available to people. We are doing this in a university which is known for its social responsibility signature. In this context, I would like to highlight the talent of my students involved in this project,” the scientist said.

 

“We were able to make it because the University enables, favours and promotes these innovation processes, besides providing the confidence to conduct high-level research,” he added.

 

Dicyt project

Dr Acuña’s meeting with foreign media correspondents was in the context of the activities of a Dicyt Public Opinion Project of Universidad de Santiago, led by Gabriela Martínez Cuevas, professor at the Department of Journalism.

 

Professor Martínez highlighted the interest of Fundación Imagen de Chile in contributing to promote the significance of this study among a group of accredited correspondents in Chile.

“Due to the strategic partnership that we developed with Fundación Imagen de Chile last year in a similar project, we have been able to arrange the first of a series of conferences with foreign accredited correspondents, during 2015,” professor Martínez said.

“This body has the purpose of managing the “nation branding”, so we have joined efforts to strengthen our “U de Santiago brand” around the world through our scientists,” she added.

Gabriela Martínez, who is also Director of the Communications Department and the institutional radio station said: “Today, the interest of the international press for learning about this study led by Dr Claudio Acuña was evident, and he insisted on the importance of the contribution made by the young researchers that he is training.”

She said: “There were correspondents of all the agencies in Europe, China and Latin America. We expect to see how they inform the world about this new contribution made by our state and public University, which is committed to the country progress and gives solutions to urgent demands beyond our borders. This was specifically demonstrated with this cancer vaccine.”

The project- which is at its preclinical stage- is based on effects of Polymixin B. It has already shown its first results in lymphoma, melanoma and breast, with an effectiveness of almost 50%. Besides, it is worth to mention that this technology could decrease the cost of current traditional cancer therapies by up to 70%.

With the support of the Chilean Economic Development Agency (Corfo, in Spanish), this technology is in the patenting process both in Chile and USA, to then continue to the clinical stage and to exporting the treatment.

Fundación Imagen de Chile

According to its web page, Fundación Imagen de Chile is an autonomous institution funded by public resources, created in 2009, with the purpose of coordinating and organizing the efforts to promote the image of Chile abroad.

Its responsibility is to mange the “nation branding”, by coordinating the work of the main sectors that contribute to build this image, such as culture, sports, exportations, investments, tourism and international relations, among others. For this purpose, the foundation develops strategic partnerships with public and private agents to coordinate the image of the country and actively position the distinctive features of our identity.

Translated by Marcela Contreras

Researchers analyzed relationship between fish stress and losses in salmon farming industry

Researchers analyzed relationship between fish stress and losses in salmon farming industry

  • The study suggests that stress in fish may be causing economic losses for the country due to its impact on the production of salmon farming industry.

According to the Chilean Undersecretariat for Fishing and Aquaculture’s report of October 2015, exports last August reached 93 different countries, likes USA, Japan, Brazil, Rusia, China and others.

The importance of this strategic productive sector to Chile's economy, led Dr Claudio Acuña Castillo, Head of the Department of Biology and researcher at the Aquaculture Biotechnology Center (CBA, in Spanish) and his colleagues at Universidad de Santiago and other institutions, to conduct a literature review to understand the stress-generating mechanisms in fish, in comparison to mammals. 

The analysis entitled Neuroendocrine mechanisms for immune system regulation during stress in fish was published on the Fish and Shellfish Immunology journal. The article has had a high impact on the scientific community and has been cited in other scientific works, allowing to go deeper in an insufficiently studied subject. “It has contributed to understand some aspects of stress in fish and to help other researchers who are interested in the same subject,” Dr Acuña said.

According to the researcher, major causes of stress among farmed fish are overcrowding, relocation, vaccines and transitions between freshwater and saltwater. The latter process happens normally in nature, but in productive contexts, it causes stress and affects the immune system of fish.

Chronic stress and acute stress

When analyzing stress in fish, Dr Acuña emphasizes that we must consider that fish are not mammals, therefore, they have a different behavior. They have different regulation mechanisms, different anatomy and a lonely life, as they are not gregarious animals.

All living organisms need some stress to develop. “Chronic stress is dangerous and harmful. When it becomes permanent, it affects the immune system. However, acute stress is necessary and useful, as it contributes to decision-making in conflict situations,” he explained.

When stress becomes chronic, it can be perceived in different ways. “Fish show physiological and behavioral changes, aggressiveness, and, sometimes, loss of appetite and increased susceptibility to contagious diseases,” he said.

Impact on aquaculture production

According to Dr Acuña, “It is highly probable that stress in fish may be having an impact on the production losses of salmon farming industry. When stress is too much, fish become susceptible to sea lice, for example. So, when all the produced fish die, as it is happening now, maybe there are not only genetic causes but stress-related factors.”

The researcher is also very worried about the side effects of production losses: lack of jobs and unemployment. He thinks that, if we begin to understand the process, we will be able to provide solutions. 

Besides, Dr Acuña expects to reduce the stress effects in fish by using natural solutions, like plants or natural elements.

The article was also led by Dr Ricardo Fernández, researcher at the Faculty of Biological Sciences and the Faculty of Medicine of Universidad Andrés Bello. Dr Gino Nardocci, Dr Cristina Navarro and Dr Paula P. Cortes, of Universidad Andrés Bello, and Dr Mónica Imarai, Dr Margarita Montoya, Dr Beatriz Valenzuela and Dr Pablo Jara, researchers at the Faculty of Chemistry and Biology and the CBA of Universidad de Santiago, collaborated with the study.

Translated by Marcela Contreras

Researchers at Universidad de Santiago develop innovative LED communication device for underground mining operations

Researchers at Universidad de Santiago develop innovative LED communication device for underground mining operations

  • The system will allow sending text, audio and video messages over long distances and at high speeds in underground mining operations. The project is led by Dr Ismael Soto, director of the Getic Laboratory of the Department of Electrical Engineering, and Dr Carolina Lagos Aguirre, alternate director of the project.

 

 

The system consists of a new device about the size of a cell phone that will enable good communications in underground mining operations by sending text, audio and video messages over long distances and at high speeds. 

Tech-Lifim (communication technology through visible light in mining operations) is a LED light-based device that transmits and decodes data through light pulses. The project is one of the research works conducted by the Department of Electrical Engineering of Universidad de Santiago de Chile.

The study is being developed by the Getic Laboratory of Universidad de Santiago (which is focused on digital signal processing for wireless communications), led by Dr Ismael Soto and Dr Carolina Lagos Aguirre, with the participation of graduate and undergraduate students at the university.

Exploring new needs

The project was started in 2010, when links were established with the Chuquicamata Division (the largest open pit copper producer in the world) of de Chilean’s National Corporation of Copper (Codelco, in Spanish), with the purpose of conducting studies on copper mining. “We gathered information about their needs and one of the issues they mentioned was the lack of communication devices, particularly for underground mining operations,” Dr Lagos says. “They asked us to develop a device able to transmit data at high speed and under adverse conditions, like high temperature, high humidity, dust and smoke.”

The research team established a strategic partnership with the company Control & Logic and started to work on the device. For a year and a half, they have continued with the research work, performed some tests and given presentations in Chuquicamata. “The device can be placed on the workers’ helmets, on underground tunnels’ walls and on trucks, to guarantee a simultaneous communication,” she says.

Global impact

According to the researchers, the system, which is currently at the production stage, is very efficient and meets the workers’ safety requirements.

Universidad de Santiago de Chile has already filed a patent request in Chile for this product. The next step will be filing a request abroad, because of a global underground mining project led by Codelco that will be started in 2019, based on the systems being implemented in Chuquicamata now,” Dr Soto explains.

In this context, they have created a company supported by the Innovo Usach business incubator. “We have the goal of placing the product in the market and start its commercialization in January 2017. Although we have worked with Chuquicamata for now, the device will be available for everyone who needs it,” the researcher says.

Other studies

This communication device is an example of the many studies that this research team intends to conduct. “We are also developing a lighting system for underground mining operations that will be available in the years to come,” Dr Soto says.

Besides, the research team is working on other projects in collaboration with foreign institutions like Northumbria University (England), the Oil and Gas University of Ploiesti (Romania) and the University of Lorraine (France).

Translated by Marcela Contreras

Exploring possibilities for commercializing reconfigurated rice developed at the University

Exploring possibilities for commercializing reconfigurated rice developed at the University

The product, a particular type of rice, produced by a project of the Facultad Tecnológica in 2008, with the support of the Fundación para la Innovación Agrícola  (FIA), is in the process of obtaining its corresponding patent.

There was a high national and international impact in May 2008, because of this  new type of reconstituted rice obtained from by-products  of  the polishing process of this cereal, such as spikes, defective pieces, flour and others. The important finding is that it requires less time and only a quarter of water than the traditional rice usually used for cooking. It has also been developed with a variety of flavors, nutrients and fiber to make it competitive.


The leader of this project was Laura Almendares, researcher at the Department of Science and Food Technology, Facultad Tecnológica. She was supported by the Fundación para la Innovación Agrícola  and by  other researchers from the University and rice producers from Parral, in the Maule Region, and El Huique, in the O'Higgins Region.

Four years after this stage of research, Professor Almendares is now actively working in obtaining the corresponding patent for  her creation and in the generation of projects to achieve the commercialization of this innovative product.

In this context, the academic recently presented a paper in Brazil at the workshop "Potential and Qualities of Rice from the West Frontier area." This event brought together researchers, farmers and rice entrepreneurs from Santa Marta - where 80 percent of Brazil’s rice is produced- and   was organized by the Federal University of Pampa, with funding from the National Council for Scientific and National Development.

"With the support of Unipampa we generated contacts with businessmen with the aim of consolidating the business model of our rice, so that it can be produced industrially and enter the market" said the specialist Almendares on her visit to Brazil.

Efforts are also made in Chile. In this regard, this researcher of the Facultad Tecnológica explores different tools to market her product among consumers in a massive way, even at the Corfo level.

"It wasn’t easy because it’s unusual for a university to generate a patent for a product to be marketed (in a  massive way)", she said. However, she  recognizes that there is a large Chilean rice company interested in producing and distributing the rice created in the laboratories of our university. Thus, this kind of rice could be soon on Chilean and foreign supermarkets shelves.

Researcher of Faculty of Chemistry and Biology joints editorial board of renowned scientific journal

Researcher of Faculty of Chemistry and Biology joints editorial board of renowned scientific journal

  • In recognition of his extensive career in the area of electrochemistry, Dr. José Zagal, professor at the Department of Chemistry of Materials, was invited to be part of the editorial board of Electrochemistry Communications, an international journal with the higher impact index in its field.

Dr. José Zagal, professor at the Department of Chemistry of Materials of our university, was selected to be part of the editorial board of Electrochemistry Communications, the renowned scientific journal partnered with Elsevier that has the higher impact index in the field of electrochemistry.

In a conversation with UdeSantiago al Día, the academic said that he understood his inclusion in the board as “recognition of my work over many years; but most important, the recognition of a work that has mainly been done by a team.”

Professor Zagal has a vast experience in the scientific research field, particularly in the study of oxygen and reactivity. He started to work at Universidad de Santiago 40 years ago and he has kept on publishing specialized articles in his field of interest since then.

Besides, he has been part of editorial boards of different scientific journals, like the International Journal of Electrochemistry of Hindawi Publishing Corporation, since 2011 and the International Journal of Biotechnology & Biochemistry (IJBB), since 2012.

Zagal said that it is very important that both students and academics produce publications in their fields and get involved in different creative processes “to contribute not only to this University’s development but to all the country.”

“I think that it is necessary that students in any program should take part in creative and practical processes, that is to say, they should get involved in laboratory work since their first years at the university, so that they produce new knowledge that can reach most of the people through renowned publications,” he said.

“Publishing research results is essential. When you make public the work you do, your work becomes recognized in that field and, at the same time, you spread new knowledge,” he added.

For this reason, professor Zagal expects that his role at the Electrochemistry Communications’ editorial board means a contribution to the promotion of sciences and to the better positioning of Universidad de Santiago de Chile.

“You stay at this university because you love it and not for the money. Many researchers here might well be working at private sector companies, but they stay here because they feel a real bond with this institution,” he said.

“For the love that I have for this University, I expect that my inclusion in the editorial board will benefit the institution and will contribute to spread knowledge among society,” Dr. Zagal concluded.

Translated by Marcela Contreras

Solutions for optimizing wine making industry processes

Solutions for optimizing wine making industry processes

  • One of the most difficult procedures in the wine making industry around the world is cleaning and removing the remaining marc from the traditional fermentation vats. Through a project funded by Corfo’s Innova Chile, Dr. Lucio Cañete, together with professors Andrés Pérez de Arce and Héctor Barrera, of the Technological Faculty, are working on the design of devices to make this task easier, providing a solution both safe for workers and economical for the industry.


 
Andrés Pérez de Arce and Héctor Barrera, together with Dr. Lucio Cañete, the three of them professors at the Technological Faculty, are analyzing the technological viability of a device to solve one of the most complex problems for the wine industry: the cleaning of the traditional vats where the must is fermented.

Up to now, the fermentation process occurs in huge steel tanks that are filled up with crushed grape juice that stays there for a week or two, until the must is removed.

As the marc - the solid residue of seeds, skins, stalks and other impurities- remains in the tank, getting it clean before using it again is a problem for the industry, because it means that a worker has to go inside the vat through a lateral hatch, what puts his health at risk because of the toxic gas build-up in this dark and damp environment.

This is one of the most required works by the wine industry but with the least supply of workers due to the hostile work conditions; that is why companies usually offer additional bonuses to attract workers, but this is still not enough.

World problem

For this reason, Professors Lucio Cañete and Héctor Herrera, of the Department of Industrial Technologies, together with Professor Andrés Pérez de Arce, of the Department of Agrarian Management of the Technological Faculty, were awarded funds through Corfo’s InnovaChile for the project Extractor de Residuos Cohesivos Desde Medianas y Grandes Cubas Viníferas, code 13IDL1-25426 (Cohesive Residues Extractor for Medium and Large-sized Wine Making Tanks), in order to develop a device to solve this problem.

“The problem affects wine making not only at a domestic level, but worldwide,” Professor Cañete explained. Although some wine producers have vats than can be turned upside down to facilitate the removal of the marc, they are very expensive, so most companies use the traditional steel or concrete tanks.

After studying different possibilities, Professors Cañete, Barrera and Pérez de Arce decided to design a device to vacuum the marc without destroying it (as it is sometimes pressed again) and without needing a worker to enter the vat.

In a few days, the researchers should deliver the first progress report. They received the funding last April and it considers the creation of a test prototype; however, the researchers have already tested their proposal in wine producing companies.

A few weeks ago, they presented the idea in the conference of the Asociación Nacional de Ingenieros Agrónomos Enólogos de Chile (National Association of Oenologist- Agronomical Engineers of Chile), held in Molina. “We had a good response, because it is a real problem for the wine industry. Our solution seeks to reduce the workers’ health risk and to optimize the available time of the vats to make the most of the harvest time,” Professor Pérez de Arce said.

Today, the project is at an initial stage of development, testing the hypothesis to model the equipment and further creation of the prototype. The most advanced methods in this process are leading to ripper-vacuum cleaner-like and Archimedes’ screw-like solutions. In both cases, the device will be introduced in the tank through the hatch, but the worker would have the possibility of controlling it from the outside.


Translated by Marcela Contreras
 

Researchers at Universidad de Santiago find similarity between algae physiological functioning and human nervous system

Researchers at Universidad de Santiago find similarity between algae physiological functioning and human nervous system

  • Researchers at the Faculty of Chemistry and Biology of Universidad de Santiago discovered the existence of functional TRP ion channels in the marine alga Ulva Compressa that are similar to the ones present at the nervous system in mammals and humans. “At first, it was difficult to imagine that these channels could exist in a marine alga, especially when they exist in mammals but not in terrestrial plants,” Dr Alejandra Moenne, researcher at the Department of Biology, says.

 


TRP channels are cellular sensors that detect and respond to different environmental stimuli, like temperature changes, pain and taste, what makes them key to many physiological processes.

“At first, it was difficult to imagine that these channels could exist in a marine alga, especially when they exist in mammals but not in terrestrial plants,” Dr Alejandra Moenne, researcher at the Department of Biology, says.

“Before having these results, we found that copper stress activates voltage dependent calcium channels (VDCC) similar to the ones present at the central nervous system of mammals. So, how the activation of voltage dependent channels was possible? We thought that the activation of VDCC depended on the previous activation of TRP channels, something difficult to imagine in a marine alga,” the researcher explains.

These results mean a change in the way how the physiological functioning of marine algae - organisms that have been present on Earth for about a thousand million years- is understood. They were published by the journal Frontiers in Plant Science in the paper "Copper-induced activation of TRP channels promotes extra cellular calcium entry, activation of CaMs and CDPKs, copper entry and membrane depolarization in Ulva compressa.” 

The researcher explains that they not only found that “there are functional TRP channels that respond to copper but also that copper stress induces the release of amino acids and amino acid derived neurotransmitters similar to the ones released by human neurons. Even more, we have preliminary evidence that suggests that there is communication among different marine algae species through these molecules.”


Future research 

In terms of research and to give answers to the new questions, Dr Moenne says that she intends to apply for a Proyecto Anillo together with researchers Juan Pablo García-Huidobro (Universidad de Santiago), Claudio Sáez (Universidad de Playa Ancha) and Erasmo Macaya (Universidad de Concepción), in order to deepen the knowledge on the communication among green, red and brown marine algae.

“As algae release amino acids and neurotransmitters- and have TRP channels and voltage dependent channels- algae functioning would be more and more similar to neurons, but with a slower response in minutes or hours, instead of the milliseconds of the neurons response,” she explains.

The paper "Copper-induced activation of TRP channels promotes extra cellular calcium entry, activation of CaMs and CDPKs, copper entry and membrane depolarization in Ulva compressa" (that received the recognition of the Editor of the journal Frontiers in Planet Science) was written by the research team of this project: Melissa Gómez, Alberto González, Claudio Sáez, Bernardo Morales and Alejandra Moenne. It is available online at http://journal.frontiersin.org/article/10.3389/fpls.2015.00182/abstract 


Translated by Marcela Contreras

Researchers develop solar energy accumulator to dry agroproducts

Researchers develop solar energy accumulator to dry agroproducts

  • In order to reduce the effects of the day-night fluctuations of solar radiation, researchers at the Department of Chemical Engineering of Universidad de Santiago developed a low-cost accumulator that allows storing solar thermal energy and avoid interruptions of the drying processes of different agricultural products. The research team is led by Dr Alejandro Reyes and the study is called “Design and evaluation of a heat exchanger that uses paraffin wax and recycled materials as solar energy accumulator”.

 

Chile has high levels of solar radiation, particularly in the northern and central zones of the country. This makes our territory an ideal area for studying and developing new methods to use solar energy. 

In this context, Dr Alejandro Reyes published part of the results of his study in the Elsevier’s journal Energy Conversion and Management. The article is called “Design and evaluation of a heat exchanger that uses paraffin wax and recycled materials as solar energy accumulator.”

Through this study, Professor Reyes seeks to solve one of the biggest problems posed by solar thermal energy: its fluctuation between day and night. He has the goal of extending the use of solar energy to hours when it is not directly received.

Solar energy can be thermally or electrically stored in batteries, by means of photovoltaic panels. In thermal storage, solids or liquids can be heated and sensible heat is stored. However, Dr Reyes’ study is focused on the phase change, i.e., the use of a solid that melts when it is heated.

Paraffin wax

Paraffin wax, similar to the one used in candle making, was the best option for this study, as it remains solid below 56OC and, above this temperature, it changes to liquid.

The change in state of paraffin wax depends on energy input or output. “For a phase transition from solid to liquid, much energy is required, so we get it from the sun. And from liquid to solid, we need to take the energy inside out,” Professor Reyes explained.

In order to melt wax and transform it to liquid and accumulate energy, Dr Reyes designed a heat accumulator that works with low-cost materials, like soft drink cans. “We designed a device in which we put paraffin in a group of soft drink cans that we painted black. We put the cans inside a box, and we closed the upper face with a glass cover, facing the sun. The solar energy melts the wax and then a cold air flow is passed trough the cans and goes out as hot air,” he said.

However, this process has some drawbacks related to the low thermal conductivity of paraffin wax that makes more difficult sucking out the heat from the cans: when liquid paraffin wax starts getting solid inside the cans, the extraction of the energy remaining in the centre of the cans is very slow.

This problem was solved by embedding aluminium wool in the paraffin wax, doubling its thermal conductivity. Aluminium strips were also placed outside the cans to improve the energy transfer to the air.

Mathematical equations

Professor Reyes says that the empirical results are correlated with the models that they have been able to develop through mathematical equations.

“Evidently, if we build a device with more cans, the energy accumulation would be proportionally higher. We have another piece of equipment with 300 cans placed on the roof of the Department of Chemical Engineering that allows extending the drying process of agroproducts to up to five hours. We have the help of thesis students and experts in modelling and a piece of software that allows predicting the results of the equipment, based on its size and the environmental conditions,” he said.

Dr Reyes expects to replicate the energy accumulator and use it for different purposes. “On the roof, we have an accumulator made of cans, plus a standard solar panel, both connected to a dryer with a drying capacity of 25 kg of agricultural products. Up to date, we have dehydrated mushrooms, onion flakes, and sweet peppers, among others.”

As the process of drying agricultural products is slow, during the day the dryer uses the solar energy obtained through the solar panel, and then at night, when the solar radiation is null, the air for drying is heated in the energy accumulator and the drying time is extended to up to 5 additional hours.

“We seek to extend the drying process all night long, by using solar energy, in spite of the radiation fluctuations between day and night,” the researcher said.

Translated by Marcela Contreras

Researcher studies new nanotechnology-based method for detecting Hepatitis B

Researcher studies new nanotechnology-based method for detecting Hepatitis B

  • According to official statistics, in Chile there are 34,000 people infected by the HBV, which is transmitted through exposure to infectious blood or body fluids. Worldwide, 240 million people live with this disease. This is the reason why Dr Camilo García, professor at the Faculty of Chemistry and Biology of Universidad de Santiago de Chile, decided to study the feasibility of a more effective and economical method for detecting this disease, in the context of a Fondecyt Initiation project awarded in 2015.

Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) which affects the liver. It is transmitted through exposure to infectious blood or body fluids and it can cause both acute and chronic infections. Hepatitis B can be fatal and cannot be cured.

According to statistics provided by the World health Organization (WHO), 240 million people worldwide suffer from chronic Hepatitis B, which can develop into cirrhosis and liver cancer. In Chile, 34,000 people are infected by the HBV

In this context, and thanks to the funding provided by a Fondecyt Initiation project (11150434), Dr Camilo García, professor at the Faculty of Chemistry and Biology of Universidad de Santiago, seeks to develop a new method for detecting this disease.

Background

According to Dr García, he has an important reason for studying this disease. In Chile, there is a specific HBV genotype: genotype F.

“I decided to study Hepatitis B to explore a new field, because this is a terrible disease and the current detection methods are very expensive, in comparison to the one that we are studying. There is a type of Hepatitis B that has only been detected in Chilean people. So, it would be great to find a sensor that detects the strain that we want to identify,” he said.

“The human quality of the work team at the Faculty of Chemistry and Biology of Universidad de Santiago was another reason to conduct this study,” he added.

After completing the three-year project, he expects to have a new detection method that contributes to the patients’ well-being and comfort during medical procedures.

Methods

“We want to see if it is possible to develop Hepatitis B sensors based on electrochemiluminescence,” professor García explained.

Quantum dots –fluorescent nanoparticles- emit light when voltage is applied. This light signal can be absorbed by a DNA-binding molecule, like cationic porphyrins.

Dr García explains that the study will be based on the comparison between linear DNA sequences and molecular beacons for Hepatitis B virus to establish if the light signal is affected by the resonance, providing novel biosensors to detect the disease.

 

Translated By Marcela Contreras

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