News Article | June 22, 2017
At EPFL, researchers challenge a fundamental law and discover that more electromagnetic energy can be stored in wave-guiding systems than previously thought. The discovery has implications in telecommunications. Working around the fundamental law, they conceived resonant and wave-guiding systems capable of storing energy over a prolonged period while keeping a broad bandwidth. Their trick was to create asymmetric resonant or wave-guiding systems using magnetic fields. The study, which has just been published in Science, was led by Kosmas Tsakmakidis, first at the University of Ottawa and then at EPFL's Bionanophotonic Systems Laboratory run by Hatice Altug, where the researcher is now doing post-doctoral research. This breakthrough could have a major impact on many fields in engineering and physics. The number of potential applications is close to infinite, with telecommunications, optical detection systems and broadband energy harvesting representing just a few examples. Resonant and wave-guiding systems are present in the vast majority of optical and electronic systems. Their role is to temporarily store energy in the form of electromagnetic waves and then release them. For more than 100 hundred years, these systems were held back by a limitation that was considered to be fundamental: the length of time a wave could be stored was inversely proportional to its bandwidth. This relationship was interpreted to mean that it was impossible to store large amounts of data in resonant or wave-guiding systems over a long period of time because increasing the bandwidth meant decreasing the storage time and quality of storage. This law was first formulated by K. S. Johnson in 1914, at Western Electric Company (the forerunner of Bell Telephone Laboratories). He introduced the concept of the Q factor, according to which a resonator can either store energy for a long time or have a broad bandwidth, but not both at the same time. Increasing the storage time meant decreasing the bandwidth, and vice versa. A small bandwidth means a limited range of frequencies (or 'colors') and therefore a limited amount of data. Until now, this concept had never been challenged. Physicists and engineers had always built resonant systems -- like those to produce lasers, make electronic circuits and conduct medical diagnoses -- with this constraint in mind. But that limitation is now a thing of the past. The researchers came up with a hybrid resonant / wave-guiding system made of a magneto-optic material that, when a magnetic field is applied, is able to stop the wave and store it for a prolonged period, thereby accumulating large amounts of energy. Then when the magnetic field is switched off, the trapped pulse is released. With such asymmetric and non-reciprocal systems, it was possible to store a wave for a very long period of time while also maintaining a large bandwidth. The conventional time-bandwidth limit was even beaten by a factor of 1,000. The scientists further showed that, theoretically, there is no upper ceiling to this limit at all in these asymmetric (non-reciprocal) systems. "It was a moment of revelation when we discovered that these new structures did not feature any time-bandwidth restriction at all. These systems are unlike what we have all been accustomed to for decades, and possibly hundreds of years», says Tsakmakidis, the study's lead author. "Their superior wave-storage capacity performance could really be an enabler for a range of exciting applications in diverse contemporary and more traditional fields of research." Hatice Altug adds. One possible application is in the design of extremely quick and efficient all-optical buffers in telecommunication networks. The role of the buffers is to temporarily store data arriving in the form of light through optical fibers. By slowing the mass of data, it is easier to process. Up to now, the storage quality had been limited.+ With this new technique, it should be possible to improve the process and store large bandwidths of data for prolonged times. Other potential applications include on-chip spectroscopy, broadband light harvesting and energy storage, and broadband optical camouflaging ("invisibility cloaking"). "The reported breakthrough is completely fundamental -- we're giving researchers a new tool. And the number of applications is limited only by one's imagination," sums up Tsakmakidis. Source: Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering Kosmas Tsakmakidis, lead author, former researcher at the University of Ottawa and currently an EPFL Fellow in EPFL's Bionanophotonic Systems Laboratory Linfang Shen and collaborators, Institute of Space Science and Technology, Nanchang University, Nanchang, China and State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou, China Prof. Robert Boyd and collaborators, University of Ottawa Prof. Hatice Altug, director of EPFL's Bionanophotonic Systems Laboratory Prof. Alexandre Vakakis, University of Illinois at Urbana-Champaign
News Article | August 14, 2017
EAST LANSING, Mich. - Seemingly indestructible Varroa mites have decimated honeybee populations and are a primary cause of colony collapse disorder, or CCD. Michigan State University scientists have found genetic holes in the pests' armor that could potentially reduce or eliminate the marauding invaders. The team's results, published in the current issue of Insect Science, have identified four genes critical for survival and two that directly affect reproduction. "The Varroa mite is the worst threat to honeybee health worldwide," said Zachary Huang, MSU entomologist. "They have developed resistance to many pesticides, so it's urgent that we explore and target these genes to develop better control methods." The mite sucks the blood of honeybees and transmits deadly viruses. Its lifecycle consists of two phases: one where they feed on adult bees, called the phoretic phase, and a reproductive phase that takes place within a sealed honeycomb cell, where the mites lay eggs on a developing bee larva. Having the double-whammy of eating bees and spreading disease makes Varroa mites the number-one suspect of honeybee population declines worldwide. Controlling pests like Varroa mites succeeds by either eliminating them or reducing their ability to reproduce. The team used RNA interference to identify the key genes, which could achieve these outcomes. They injected the mites with double-stranded RNA, or dsRNA. Interfering reduces transcription of a specific gene, the first step of making a gene, a piece of DNA, into a protein. This process, also known as "gene knockdown," has been successful in reducing the mating success and the number of eggs produced by cattle ticks, which threaten cows and other livestock around the world. Using this approach, the team identified two genes that caused high mortality in Varroa mites - Da and Pros26S. In fact, Da killed more than 96 percent of mites. They also identified four genes - RpL8, RpL11, RpP0 and RpS13 - that control reproduction. Earlier research has shown that a combination of dsRNAs can be fed to bees at the colony level. Varroa mites absorb the "genetic cocktail" via bee blood and their population was reduced. Future research will explore whether a single-gene approach can be scaled up and achieve the same effect at a colony-wide setting. Using a single gene with a known mechanism will be more cost effective and safe to the honeybees. The results may have applications beyond honeybees, too. "It's worth noting that Da reduced reproduction in species of mosquitoes and Drosophila," Huang said. "Future research could help not only protect honeybees, but also reduce disease-carrying mosquitoes or crop-damaging pests." Additional MSU researchers contributing to this study include Guowu Bian and Zhiyong Xi. Xianbing Xie, with Nanchang University (China), also was part of this paper. This study was supported by the Almond Board of California, the Foundation for the Preservation of Honey Bees, the National Honey Board, MSU's Project GREEEN, Michigan Beekeepers Association, National Natural Science Foundation of China, General Project of Jiangxi Provincial Department of Education and a fellowship from the China Scholarship Council. Michigan State University has been working to advance the common good in uncommon ways for more than 150 years. One of the top research universities in the world, MSU focuses its vast resources on creating solutions to some of the world's most pressing challenges, while providing life-changing opportunities to a diverse and inclusive academic community through more than 200 programs of study in 17 degree-granting colleges. For MSU news on the Web, go to MSUToday. Follow MSU News on Twitter at twitter.com/MSUnews.
News Article | August 14, 2017
ROCHESTER, Minn. -- Mayo Clinic researchers have identified a new cause of treatment resistance in prostate cancer. Their discovery also suggests ways to improve prostate cancer therapy. The findings appear in Nature Medicine. In the publication, the authors explain the role of mutations within the SPOP gene on the development of resistance to one class of drugs. SPOP mutations are the most frequent genetic changes seen in primary prostate cancer. These mutations play a central role in the development of resistance to drugs called BET-inhibitors. BET, bromodomain and extra-terminal domain, inhibitors are drugs that prevent the action of BET proteins. These proteins help guide the abnormal growth of cancer cells. As a therapy, BET-inhibitors are promising, but drug resistance often develops, says Haojie Huang, Ph.D., senior author and a molecular biologist within Mayo Clinic's Center for Biomedical Discovery. Prostate cancer is among the most diagnosed malignancies in the United States. It is also the third leading cause of cancer death in American men, according to the American Cancer Society. Because of this, says Dr. Huang, improving treatments for prostate cancer is an important public health goal. In the publication, the authors report SPOP mutations stabilize BET proteins against the action of BET-inhibitors. By this action, the mutations also promote cancer cell proliferation, invasion and survival. "These findings have important implications for prostate cancer treatment, because SPOP mutation or elevated BET protein expression can now be used as biomarkers to improve outcome of BET inhibitor-oriented therapy of prostate cancer with SPOP mutation or BET protein overexpression," says Dr. Huang. Mutations in the SPOP gene can then be used to guide administration of anti-cancer drugs in patients with prostate cancer: The Nature Medicine publication presents four major discoveries: In addition to Dr. Huang, other authors from Mayo Clinic are: Authors from Fudan University, Nanchang University, Xinhua Hospital at Shanghai Jiao Tong University Medical School, and Second Military Medical University in China are listed in the publication. The authors report no conflicts of interest. Funding for this work was provided by the National Institutes of Health, the U.S. Department of Defense, the National Natural Science Foundation of China, and the National Key Research and Development Plan of China -- Precision Medicine Project. Mayo Clinic is a nonprofit organization committed to clinical practice, education and research, providing expert, comprehensive care to everyone who needs healing. For more information, visit mayoclinic.org/about-mayo-clinic or newsnetwork.mayoclinic.org.
News Article | August 15, 2017
Scientists have discovered a group of genes critical to the survival and reproduction of Varroa mites, the chief enemy of honey bees. The genes could be targeted to control or eliminate the mites. Seemingly indestructible Varroa mites have decimated honey bee populations and are a primary cause of colony collapse disorder, or CCD. “The Varroa mite is the worst threat to honey bee health worldwide,” says Zachary Huang, Michigan State University entomologist. “They have developed resistance to many pesticides, so it’s urgent that we explore and target these genes to develop better control methods.” The mite sucks the blood of honey bees and transmits deadly viruses. Its lifecycle consists of two phases: one where they feed on adult bees, called the phoretic phase, and a reproductive phase that takes place within a sealed honeycomb cell, where the mites lay eggs on a developing bee larva. Having the double-whammy of eating bees and spreading disease makes Varroa mites the number-one suspect of honey bee population declines worldwide. Controlling pests like Varroa mites succeeds by either eliminating them or reducing their ability to reproduce. The team used RNA interference to identify the key genes, which could achieve these outcomes. They injected the mites with double-stranded RNA, or dsRNA. Interfering reduces transcription of a specific gene, the first step of making a gene, a piece of DNA, into a protein. This process, also known as “gene knockdown,” has been successful in reducing the mating success and the number of eggs produced by cattle ticks, which threaten cows and other livestock around the world. Using this approach, the team identified two genes that caused high mortality in Varroa mites—Da and Pros26S. In fact, Da killed more than 96 percent of mites. They also identified four genes—RpL8, RpL11, RpP0, and RpS13—that control reproduction. Earlier research has shown that a combination of dsRNAs can be fed to bees at the colony level. Varroa mites absorb the “genetic cocktail” via bee blood and their population was reduced. Future research will explore whether a single-gene approach can be scaled up and achieve the same effect at a colony-wide setting. Using a single gene with a known mechanism will be more cost effective and safe to the honey bees. The results may have applications beyond honey bees, too. “It’s worth noting that Da reduced reproduction in species of mosquitoes and Drosophila,” Huang says. “Future research could help not only protect honey bees, but also reduce disease-carrying mosquitoes or crop-damaging pests.” Additional researchers contributing to this study are from Michigan State University and Nanchang University, China. The Almond Board of California, the Foundation for the Preservation of Honey Bees, the National Honey Board, MSU’s Project GREEEN, the Michigan Beekeepers Association, the National Natural Science Foundation of China, the General Project of Jiangxi Provincial Department of Education, and a fellowship from the China Scholarship Council provided funding for the work.
Fang X.,Nanchang University
International Journal of Neuroscience | Year: 2016
Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative diseases with pathophysiology that may be related to the gastrointestinal tract. It is well established that tissue barriers maintain homeostasis and health. Furthermore, gut microbiota may have an impact on brain activity through the gut-microbiota–brain axis under both physiological and pathological conditions. In this review, we highlight the current knowledge regarding the role of gut microbiota and tissue barriers in PD and ALS. To our knowledge, this is the first review of the key issues involving both the altered gut microbiota and impaired tissue barriers in the pathophysiology of PD and ALS. © 2015 Taylor & Francis.
Deng X.-F.,Nanchang University
Astrophysical Journal | Year: 2010
From theMain galaxy sample of the Sloan Digital Sky Survey Data Release 7, I construct two volume-limited samples with luminosities -20.5 ≤ M r ≤ -18.5 and -22.5≤ Mr ≤-20.5, respectively, to explore the environmental dependence of the star formation rate (SFR) and the specific star formation rate (SSFR) at fixed morphology. It is found that in these two volume-limited samples, galaxies in the lowest density regime preferentially have higher SFR and SSFR than galaxies in the densest regime. I divide each volume-limited Main galaxy sample into two distinct populations, the early type and the late type, and observe that the environmental dependence of the SFR and SSFR of galaxies remains true at fixed morphology: the SFR and SSFR of galaxies in the densest regime is still preferentially lower than that of the ones in the lowest density regime with the same morphological type. I also note that the environmental dependence of the SFR and SSFR of late-type galaxies is stronger than that of early-type galaxies. © 2010. The American Astronomical Society. All rights reserved.
Hu B.,Nanchang University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013
In this paper we discuss a new way to derive neutrino mixing patterns, which originates from the idea proposed in a recent article by Hernandez and Smirnov. Its applications to various cases are discussed. We first present the complete set of possible mixing patterns for the minimal case where unbroken residual symmetries of the Majorana neutrino and left-handed charged-lepton mass matrices obey some general assumptions that are also satisfied by many models based on discrete symmetries. We find that they are either well-known mixing patterns or phenomenologically disfavored ones. It shows clearly that, for full-mixing matrices to fit the mixing data with small or negligible corrections, it is necessary to go beyond the minimal scenario. We present an explicit formalism for a rather general nonminimal case. Some applications and phenomenological implications are discussed. Several new mixing patterns are derived. © 2013 American Physical Society.
Peng X.,Nanchang University
Journal of molecular and cellular cardiology | Year: 2013
FAT10 is a new member of the ubiquitin-like protein family with yet-to-be defined biological functions in the heart. Our objective was to determine the role of FAT10 in the heart. FAT10 is expressed in the normal human and murine hearts, as detected by qPCR and Western blotting. Expression of FAT10 is increased in the heart at the border zone of myocardial infarction and in cultured neonatal rat cardiac myocytes (NRCM) subjected to hypoxia/reoxygenation (H/R) stress. Lentiviral-mediated overexpression of FAT10 in NRCM reduced p53 (TP53) and its target miR-34a levels, while BCL2 level, a target of miR-34a, was increased and BAX level, a pro-apoptotic protein, was reduced. These changes were associated with reduced apoptosis, detected by FACS analysis of annexin-V expression and TUNEL assay, in response to H/R injury. Knock down of FAT10 by shRNA targeting had the opposite effects. Likewise, lentiviral mediated expression of miR-34a was associated with reduced BCL2 and increased BAX levels in NRCM and also reversed changes in BCL-2 and BAX levels observed upon over-expression of FAT10. Treatment of NRCM with proteasome inhibitor MG132 increased p53 and miR-34a levels and reduced BLC2/BAX ratio. These changes were not reversed upon over-expression of FAT10. Thus, FAT10 is upregulated in the heart and NRCM in response to H/R stress, which protects cardiac myocytes against apoptosis. The anti-apoptotic effects of FAT10 are associated with suppression of p53, probably through fatylation and proteasomal degradation, reduced miR-34a expression, and a shift in the BCL2/BAX proteins against apoptosis. Thus, FAT10 is a cardioprotective protein. Copyright © 2013 Elsevier Ltd. All rights reserved.
Nanchang University | Date: 2013-12-24
The present invention provides a treating method for a solution containing rare earth, wherein the method comprising: (1) performing a fine-grained clay adsorption on the solution containing rare earth with fine-grained clay, the conditions of the fine-grained clay adsorption allow that solution adsorbed by said fine-grained clay contains rare earth with a concentration calculated by rare earth oxides not higher than 1 mg/L; (2) performing a coarse-grained clay adsorption on the solution adsorbed by said fine-grained clay with coarse-grained clay, the conditions of coarse-grained clay adsorption allow that solution adsorbed by said coarse-grained clay contains rare earth with a concentration calculated by rare earth oxides not higher than 0.5 mg/L; the grain diameter of at least 90% of said fine-grained clay particles is smaller than the grain diameter of said coarse-grained clay particles, and the grain diameter of said fine-grained clay is within a range of 1-250 m, and the grain diameter of said coarse-grained clay is within a range of 150-1,000 m; and (3) desorbing rare earth from said fine-grained clay undergone the fine-grained clay adsorption and said coarse-grained clay undergone the coarse-grained clay adsorption. The rare earth may be effectively recycled by applying the above method.
Nanchang University | Date: 2016-07-05
A device for producing semi-solid slurry, including a height adjustment mechanism, a position adjustment mechanism, a melt protection mechanism, a support mechanism, a revolving pipe, guide mechanisms, thermally-adapted elastic supports, a driving mechanism of the revolving pipe, and a cooling module. The height adjustment mechanism is a box structure including an upper casing and a lower casing. The position adjustment mechanism includes a stationary rail and a moving rail support, and the stationary rail is fixed on the upper casing of the height adjustment mechanism. The melt protection mechanism includes a seal box including a base plate fixed on the moving rail support. The support mechanism includes a main support frame and an angle adjustment bracket, the main support frame is fixed on the base plate of the seal box, and the angle adjustment bracket is mounted on the main support frame.