bluuebunny/crossref_metadata_2025 huggingface dataset:
Confinement-deconfinement transition due to spontaneous symmetry breaking in quantum Hall bilayers
Authors: Pikulin D. I. , Silvestrov P. G. , Hyart T.
Published: January 2016

Band-inverted electron-hole bilayers support quantum spin Hall insulator and exciton condensate phases. Interest in quantum spin Hall effect in these systems has recently put them in the spotlight. We investigate such a bilayer in an external magnetic field. We show that the interlayer correlations lead to formation of a helical quantum Hall exciton condensate state. Existence of the counterpropagating edge modes in this system results in formation of a ground state spin-texture not supporting gapless single-particle excitations. The charged edge excitations in a sufficiently narrow Hall bar are confined: a charge on one of the edges always gives rise to an opposite charge on the other edge. Magnetic field and gate voltages allow the control of a confinement-deconfinement transition of charged edge excitations, which can be probed with nonlocal conductance. Confinement-deconfinement transitions are of great interest, not least because of their possible significance in shedding light on the confinement problem of quarks.
Structures of the E. coli translating ribosome with SRP and its receptor and with the translocon
Authors: Jomaa Ahmad , Boehringer Daniel , Leibundgut Marc , Ban Nenad
Published: January 2016

Co-translational protein targeting to membranes is a universally conserved process. Central steps include cargo recognition by the signal recognition particle and handover to the Sec translocon. Here we present snapshots of key co-translational-targeting complexes solved by cryo-electron microscopy at near-atomic resolution, establishing the molecular contacts between the Escherichia coli translating ribosome, the signal recognition particle and the translocon. Our results reveal the conformational changes that regulate the latching of the signal sequence, the release of the heterodimeric domains of the signal recognition particle and its receptor, and the handover of the signal sequence to the translocon. We also observe that the signal recognition particle and the translocon insert-specific structural elements into the ribosomal tunnel to remodel it, possibly to sense nascent chains. Our work provides structural evidence for a conformational state of the signal recognition particle and its receptor primed for translocon binding to the ribosome–nascent chain complex.
Single-ion adsorption and switching in carbon nanotubes
Authors: Bushmaker Adam W. , Oklejas Vanessa , Walker Don , Hopkins Alan R. , Chen Jihan , Cronin Stephen B.
Published: January 2016

Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes, by the mechanism of ion potential-induced carrier depletion, which is supported by density functional and Landauer transport theory. Our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.
A novel mechanism for the biogenesis of outer membrane vesicles in Gram-negative bacteria
Authors: Roier Sandro , Zingl Franz G. , Cakar Fatih , Durakovic Sanel , Kohl Paul , Eichmann Thomas O. , Klug Lisa , Gadermaier Bernhard , Weinzerl Katharina , Prassl Ruth , Lass Achim , Daum Günther , Reidl Joachim , Feldman Mario F. , Schild Stefan
Published: January 2016

Bacterial outer membrane vesicles (OMVs) have important biological roles in pathogenesis and intercellular interactions, but a general mechanism of OMV formation is lacking. Here we show that the VacJ/Yrb ABC (ATP-binding cassette) transport system, a proposed phospholipid transporter, is involved in OMV formation. Deletion or repression of VacJ/Yrb increases OMV production in two distantly related Gram-negative bacteria, Haemophilus influenzae and Vibrio cholerae. Lipidome analyses demonstrate that OMVs from VacJ/Yrb-defective mutants in H. influenzae are enriched in phospholipids and certain fatty acids. Furthermore, we demonstrate that OMV production and regulation of the VacJ/Yrb ABC transport system respond to iron starvation. Our results suggest a new general mechanism of OMV biogenesis based on phospholipid accumulation in the outer leaflet of the outer membrane. This mechanism is highly conserved among Gram-negative bacteria, provides a means for regulation, can account for OMV formation under all growth conditions, and might have important pathophysiological roles in vivo.
Hepatic adenylate cyclase 3 is upregulated by Liraglutide and subsequently plays a protective role in insulin resistance and obesity
Authors: Liang Y , Li Z , Liang S , Li Y , Yang L , Lu M , Gu H F , Xia N
Published: January 2016

Objective:

Recent studies have demonstrated that adenylate cyclase 3 (AC3) has a protective role in obesity. This gene resides at the pathway with glucagon-like peptide (GLP)-1. Liraglutide is a GLP-1 analog and has independent glucose and body weight (BW)-reducing effects. In the present study, we aimed to examine whether hepatic AC3 activity was regulated by Liraglutide and to further understand the effect of AC3 in reduction of BW and insulin resistance.

Subjects:

The diabesity and obese mice were induced from db/db and C57BL/6 J mice, respectively, by high-fat diet. Liraglutide (0.1 mg kg−1 per 12 h) was given to the mice twice daily for 12 weeks. C57BL/6 J mice fed with chow diet and obese or diabesity mice treated with saline were used as the controls. Hepatic AC3 gene expression at mRNA and protein levels was analyzed with real-time reverse transcription-PCR and western blot. Fasting blood glucose and serum insulin levels were measured and followed insulin resistance index (HOMA-IR) was evaluated according to the homeostasis model assessment.

Results:

After administration of Liraglutide, BW and HOMA-IR in obese and diabesity mice were decreased, whereas hepatic AC3 mRNA and protein expression levels were upregulated. The AC3 gene expression was negatively correlated with BW, HOMA-IR and the area ratio of hepatic fat deposition in the liver.

Conclusions:

The present study thus provides the evidence that hepatic AC3 gene expression is upregulated by Liraglutide. The reduction of BW and improvement of insulin resistance with Liraglutide may be partially explained by AC3 activation.
Serum S-adenosylmethionine, but not methionine, increases in response to overfeeding in humans
Authors: Elshorbagy A K , Jernerén F , Samocha-Bonet D , Refsum H , Heilbronn L K
Published: January 2016

Background:

Plasma concentration of the methyl donor S-adenosylmethionine (SAM) is linearly associated with body mass index (BMI) and fat mass. As SAM is a high-energy compound and a sensor of cellular nutrient status, we hypothesized that SAM would increase with overfeeding.

Methods:

Forty normal to overweight men and women were overfed by 1250 kcal per day for 28 days.

Results:

Serum SAM increased from 106 to 130 nmol/l (P=0.006). In stratified analysis, only those with weight gain above the median (high-weight gainers; average weight gain 3.9±0.3 kg) had increased SAM (+42%, P=0.001), whereas low-weight gainers (weight gain 1.5±0.2 kg) did not (Pinteraction=0.018). Overfeeding did not alter serum concentrations of the SAM precursor, methionine or the products, S-adenosyl-homocysteine and homocysteine. The SAM/SAH (S-adenosylhomocysteine) ratio was unchanged in the total population, but increased in high-weight gainers (+52%, P=0.006, Pinteraction =0.005). Change in SAM correlated positively with change in weight (r=0.33, P=0.041) and fat mass (r=0.44, P=0.009), but not with change in protein intake or plasma methionine, glucose, insulin or low-density lipoprotein (LDL)-cholesterol.

Conclusion:

Overfeeding raised serum SAM in proportion to the fat mass gained. The increase in SAM may help stabilize methionine levels, and denotes a responsiveness of SAM to nutrient state in humans. The role of SAM in human energy metabolism deserves further attention.
Global effects of local food-production crises: a virtual water perspective
Authors: Tamea Stefania , Laio Francesco , Ridolfi Luca
Published: January 2016

By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008–09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.
Direct Synthesis of Multicolor Fluorescent Hollow Carbon Spheres Encapsulating Enriched Carbon Dots
Authors: Chen Qiao-Ling , Ji Wen-Qing , Chen Su
Published: January 2016

Multicolor fluorescent hollow carbon spheres (HCSs) are fabricated by an easy one-step route of in situ pyrolysis process with the use of natural scales and collagen powders as the precursor. The gas blow forming mechanism and photoluminescence (PL) emission mechanism of HCSs have been thoroughly discussed and proved that HCSs represent the first examples of three-dimensional multicolor fluorescent nanomaterials based on carbon dots (CDs). The HCSs encapsulate enriched carbon dots with high quantum yields (QYs) of 38% and thus are applied in inkjet printing and sensitized solar cells. This strategy offers a promising avenue for preparing multicolor fluorescent hollow carbon materials on an industrial scale.
Hunting for Monolayer Oxide Nanosheets and Their Architectures
Authors: Kim Hyung-Jun , Osada Minoru , Ebina Yasuo , Sugimoto Wataru , Tsukagoshi Kazuhito , Sasaki Takayoshi
Published: January 2016

In two-dimensional materials, thickness identification with a sufficient characterization range is essential to fundamental study and practical applications. Here, we report a universal optical method for rapid and reliable identification of single- to quindecuple-layers in oxide nanosheets (Ti0.87O2, Ca2Nb3O10, Ca2NaNb4O13). Because of their wide bandgap nature (Eg = ∼4 eV) and zero opacity, most oxide nanosheets exhibit a weak white-light contrast (<1.5%), which precludes optical identification. Through a systematic study of the optical reflectivity of Ti0.87O2 nanosheets on SiO2/Si substrates, we show that the use of thinner SiO2 (∼100 nm) offers optimum visualization conditions with a contrast of >5%; the contrast is a nonmonotonic function of wavelength and changes its sign at ≈550 nm; the nanosheets are brighter than the substrate at short wavelengths and darker at long ones. Such a nonmonotonic optical response is common to semiconducting oxide nanosheets, including Ca2Nb3O10 and Ca2NaNb4O13. The optical contrast differences between the substrates and nanosheets with different numbers of layers were collected, serving as a standard reference from which the number of layers can be determined by optical microscopy. Our method will facilitate the thickness-dependent study of various oxide nanosheets and their architectures, as well as expedite research toward practical applications.
Insights into the venom composition and evolution of an endoparasitoid wasp by combining proteomic and transcriptomic analyses
Authors: Yan Zhichao , Fang Qi , Wang Lei , Liu Jinding , Zhu Yu , Wang Fei , Li Fei , Werren John H. , Ye Gongyin
Published: January 2016

Parasitoid wasps are abundant and diverse hymenopteran insects that lay their eggs into the internal body (endoparasitoid) or on the external surface (ectoparasitoid) of their hosts. To make a more conducive environment for the wasps’ young, both ecto- and endoparasitoids inject venoms into the host to modulate host immunity, metabolism and development. Endoparasitoids have evolved from ectoparasitoids independently in different hymenopteran lineages.Pteromalus puparum, a pupal endoparasitoid of various butterflies, represents a relatively recent evolution of endoparasitism within pteromalids. Using a combination of transcriptomic and proteomic approaches, we have identified 70 putative venom proteins inP. puparum. Most of them show higher similarity to venom proteins from the related ectoparasitoidNasonia vitripennisthan from other more distantly related endoparasitoids. In addition, 13 venom proteins are similar to venoms of distantly related endoparasitoids but have no detectable venom matches inNasonia. These venom proteins may have a role in adaptation to endoparasitism. Overall, these results lay the groundwork for more detailed studies of venom function and adaptation to the endoparasitic lifestyle.
Growing sensitivity of maize to water scarcity under climate change
Authors: Meng Qingfeng , Chen Xinping , Lobell David B. , Cui Zhenling , Zhang Yi , Yang Haishun , Zhang Fusuo
Published: January 2016

Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.
Inhibition of Lysyl Oxidase and Lysyl Oxidase-Like Enzymes Has Tumour-Promoting and Tumour-Suppressing Roles in Experimental Prostate Cancer
Authors: Nilsson Maria , Adamo Hanibal , Bergh Anders , Halin Bergström Sofia
Published: January 2016

Lysyl oxidase (LOX) and LOX-like (LOXL) enzymes are key players in extracellular matrix deposition and maturation. LOX promote tumour progression and metastasis, but it may also have tumour-inhibitory effects. Here we show that orthotopic implantation of rat prostate AT-1 tumour cells increased LOX and LOXLs mRNA expressions in the tumour and in the surrounding non-malignant prostate tissue. Inhibition of LOX enzymes, using Beta-aminopropionitrile (BAPN), initiated before implantation of AT-1 cells, reduced tumour growth. Conversely, treatment that was started after the tumours were established resulted in unaffected or increased tumour growth. Moreover, treatment with BAPN did not suppress the formation of spontaneous lymph node metastases, or lung tumour burden, when tumour cells were injected intravenously. A temporal decrease in collagen fibre content, which is a target for LOX, was observed in tumours and in the tumour-adjacent prostate tissue. This may explain why early BAPN treatment is more effective in inhibiting tumour growth compared to treatment initiated later. Our data suggest that the enzymatic function of the LOX family is context-dependent, with both tumour-suppressing and tumour-promoting properties in prostate cancer. Further investigations are needed to understand the circumstances under which LOX inhibition may be used as a therapeutic target for cancer patients.
Glucose restriction induces transient G2 cell cycle arrest extending cellular chronological lifespan
Authors: Masuda Fumie , Ishii Mahiro , Mori Ayaka , Uehara Lisa , Yanagida Mitsuhiro , Takeda Kojiro , Saitoh Shigeaki
Published: January 2016

While glucose is the fundamental source of energy in most eukaryotes, it is not always abundantly available in natural environments, including within the human body. Eukaryotic cells are therefore thought to possess adaptive mechanisms to survive glucose-limited conditions, which remain unclear. Here, we report a novel mechanism regulating cell cycle progression in response to abrupt changes in extracellular glucose concentration. Upon reduction of glucose in the medium, wild-type fission yeast cells undergo transient arrest specifically at G2 phase. This cell cycle arrest is dependent on the Wee1 tyrosine kinase inhibiting the key cell cycle regulator, CDK1/Cdc2. Mutant cells lacking Wee1 are not arrested at G2 upon glucose limitation and lose viability faster than the wild-type cells under glucose-depleted quiescent conditions, suggesting that this cell cycle arrest is required for extension of chronological lifespan. Our findings indicate the presence of a novel cell cycle checkpoint monitoring glucose availability, which may be a good molecular target for cancer therapy.
High early life mortality in free-ranging dogs is largely influenced by humans
Authors: Paul Manabi , Sen Majumder Sreejani , Sau Shubhra , Nandi Anjan K. , Bhadra Anindita
Published: January 2016

Free-ranging dogs are a ubiquitous part of human habitations in many developing countries, leading a life of scavengers dependent on human wastes for survival. The effective management of free-ranging dogs calls for understanding of their population dynamics. Life expectancy at birth and early life mortality are important factors that shape life-histories of mammals. We carried out a five year-long census based study in seven locations of West Bengal, India, to understand the pattern of population growth and factors affecting early life mortality in free-ranging dogs. We observed high rates of mortality, with only ~19% of the 364 pups from 95 observed litters surviving till the reproductive age; 63% of total mortality being human influenced. While living near people increases resource availability for dogs, it also has deep adverse impacts on their population growth, making the dog-human relationship on streets highly complex.
Botulinum neurotoxin type-A enters a non-recycling pool of synaptic vesicles
Authors: Harper Callista B. , Papadopulos Andreas , Martin Sally , Matthews Daniel R. , Morgan Garry P. , Nguyen Tam H. , Wang Tong , Nair Deepak , Choquet Daniel , Meunier Frederic A.
Published: January 2016

Neuronal communication relies on synaptic vesicles undergoing regulated exocytosis and recycling for multiple rounds of fusion. Whether all synaptic vesicles have identical protein content has been challenged, suggesting that their recycling ability may differ greatly. Botulinum neurotoxin type-A (BoNT/A) is a highly potent neurotoxin that is internalized in synaptic vesicles at motor nerve terminals and induces flaccid paralysis. Recently, BoNT/A was also shown to undergo retrograde transport, suggesting it might enter a specific pool of synaptic vesicles with a retrograde trafficking fate. Using high-resolution microscopy techniques including electron microscopy and single molecule imaging, we found that the BoNT/A binding domain is internalized within a subset of vesicles that only partially co-localize with cholera toxin B-subunit and have markedly reduced VAMP2 immunoreactivity. Synaptic vesicles loaded with pHrodo-BoNT/A-Hc exhibited a significantly reduced ability to fuse with the plasma membrane in mouse hippocampal nerve terminals when compared with pHrodo-dextran-containing synaptic vesicles and pHrodo-labeled anti-GFP nanobodies bound to VAMP2-pHluorin or vGlut-pHluorin. Similar results were also obtained at the amphibian neuromuscular junction. These results reveal that BoNT/A is internalized in a subpopulation of synaptic vesicles that are not destined to recycle, highlighting the existence of significant molecular and functional heterogeneity between synaptic vesicles.
The Amino Acid Transporter JhI-21 Coevolves with Glutamate Receptors, Impacts NMJ Physiology and Influences Locomotor Activity in Drosophila Larvae
Authors: Ziegler Anna B. , Augustin Hrvoje , Clark Nathan L. , Berthelot-Grosjean Martine , Simonnet Mégane M. , Steinert Joern R. , Geillon Flore , Manière Gérard , Featherstone David E. , Grosjean Yael
Published: January 2016

Changes in synaptic physiology underlie neuronal network plasticity and behavioral phenomena, which are adjusted during development. TheDrosophilalarval glutamatergic neuromuscular junction (NMJ) represents a powerful synaptic model to investigate factors impacting these processes. Amino acids such as glutamate have been shown to regulateDrosophilaNMJ physiology by modulating the clustering of postsynaptic glutamate receptors and thereby regulating the strength of signal transmission from the motor neuron to the muscle cell. To identify amino acid transporters impacting glutmatergic signal transmission, we used Evolutionary Rate Covariation (ERC), a recently developed bioinformatic tool. Our screen identified ten proteins co-evolving with NMJ glutamate receptors. We selected one candidate transporter, the SLC7 (Solute Carrier) transporter family member JhI-21 (Juvenile hormone Inducible-21), which is expressed inDrosophilalarval motor neurons. We show that JhI-21 suppresses postsynaptic muscle glutamate receptor abundance and that JhI-21 expression in motor neurons regulates larval crawling behavior in a developmental stage-specific manner.
All-photonic drying and sintering process via flash white light combined with deep-UV and near-infrared irradiation for highly conductive copper nano-ink
Authors: Hwang Hyun-Jun , Oh Kyung-Hwan , Kim Hak-Sung
Published: January 2016

We developed an ultra-high speed photonic sintering method involving flash white light (FWL) combined with near infrared (NIR) and deep UV light irradiation to produce highly conductive copper nano-ink film. Flash white light irradiation energy and the power of NIR/deep UV were optimized to obtain high conductivity Cu films. Several microscopic and spectroscopic characterization techniques such as scanning electron microscopy (SEM), a x-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) spectroscopy were employed to characterize the Cu nano-films. Optimally sintered Cu nano-ink films produced using a deep UV-assisted flash white light sintering technique had the lowest resistivity (7.62 μΩ·cm), which was only 4.5-fold higher than that of bulk Cu film (1.68 μΩ•cm).
AMPK Suppresses Connexin43 Expression in the Bladder and Ameliorates Voiding Dysfunction in Cyclophosphamide-induced Mouse Cystitis
Authors: Zhang Xiling , Yao Jian , Gao Kun , Chi Yuan , Mitsui Takahiko , Ihara Tatsuya , Sawada Norifumi , Kamiyama Manabu , Fan Jianglin , Takeda Masayuki
Published: January 2016

Bladder voiding dysfunction is closely related to local oxidation, inflammation and enhanced channel activities. Given that the AMP-activated protein kinase (AMPK) has anti-oxidative, anti-inflammatory and channel-inhibiting properties, we examined whether and how AMPK affected bladder activity. AMPK activation in rat bladder smooth muscle cells (BSMCs) using three different AMPK agonists resulted in a decrease in connexin43 (Cx43) expression and function, which was associated with reduced CREB phosphorylation, Cx43 promoter activity and mRNA expression, but not Cx43 degradation. Downregulation of CREB with siRNA increased Cx43 expression. A functional analysis revealed that AMPK weakened BSMC contraction and bladder capacity. AMPK also counteracted the IL-1β- and TNFα-induced increase in Cx43 in BSMCs. In vivo administration of the AMPK agonist AICAR attenuated cyclophosphamide-initiated bladder oxidation, inflammation, Cx43 expression and voiding dysfunction. Further analysis comparing the responses of the wild-type (Cx43+/+) and heterozygous (Cx43+/−) Cx43 mice to cyclophosphamide revealed that the Cx43+/− mice retained a relatively normal micturition pattern compared to the Cx43+/+ mice. Taken together, our results indicate that AMPK inhibits Cx43 in BSMCs and improves bladder activity under pathological conditions. We propose that strategies that target AMPK can be developed as novel therapeutic approaches for treating bladder dysfunction.
Loss of CAR promotes migration and proliferation of HaCaT cells and accelerates wound healing in rats via Src-p38 MAPK pathway
Authors: Su Linlin , Fu Lanqing , Li Xiaodong , Zhang Yue , Li Zhenzhen , Wu Xue , Li Yan , Bai Xiaozhi , Hu Dahai
Published: January 2016

The coxsackie and adenovirus receptor (CAR) is a cell adhesion molecule mostly localized to cell-cell contacts in epithelial and endothelial cells. CAR is known to regulate tumor progression, however, its physiological role in keratinocyte migration and proliferation, two essential steps in re-epithelialization during wound healing, has less been investigated. Here we showed that CAR was predominantly expressed in the epidermis of human skin, CAR knockdown by RNAi significantly accelerated HaCaT cell migration and proliferation. In addition, knockdown of CAR in vitro increased p-Src, p-p38 and p-JNK protein levels; however, Src inhibitor PP2 prevented the increase of p-Src and p-p38 induced by CAR RNAi, but not p-JNK and decelerated cell migration and proliferation. More intriguingly, in vivo CAR RNAi on the skin area surrounding the wounds on rat back visually accelerated wound healing and re-epithelialization process, while treatment with PP2 or p38 inhibitor SB203580 obviously inhibited these effects. By contrast, overexpressing CAR in HaCaT cells significantly decelerated cell migration and proliferation. Above results demonstrate that suppression of CAR could accelerate HaCaT cell migration and proliferation and promote wound healing in rat skin, probably via Src-p38 MAPK pathway. CAR thus might serve as a novel therapeutic target for facilitating wound healing.
Insights into cationic ordering in Re-based double perovskite oxides
Authors: Lim Tae-Won , Kim Sung-Dae , Sung Kil-Dong , Rhyim Young-Mok , Jeen Hyungjeen , Yun Jondo , Kim Kwang-Ho , Song Ki-Myung , Lee Seongsu , Chung Sung-Yoon , Choi Minseok , Choi Si-Young
Published: January 2016

Cationic ordering in Sr2FeReO6 (SFRO) and Sr2CrReO6 (SCRO) is investigated using magnetic property measurement, atomic-scale imaging and first-principles calculations. We find that the nature of cationic ordering strongly depends on the host oxides, although they have the same crystal symmetry and chemical formula. Firstly, adding Re is effective to enhance the cationic ordering in SFRO, but makes it worse in SCRO. Secondly, the microscopic structure of antisite (AS) defects, associated with the level of cationic ordering, is also distinguishable; the AS defects in SFRO are clustered in the form of an antiphase-boundary-like feature, while they are randomly scattered in SCRO. Interestingly, we observe that the clustered AS defects deteriorate the ferromagnetism more than the scattered defects. Our findings elevate the importance of the AS defect configuration as well as the amount of defects in terms of magnetic property.
Essential role of proteasomes in maintaining self-renewal in neural progenitor cells
Authors: Zhao Yunhe , Liu Xueqin , He Zebin , Niu Xiaojie , Shi Weijun , Ding Jian M. , Zhang Li , Yuan Tifei , Li Ang , Yang Wulin , Lu Li
Published: January 2016

Protein turnover and homeostasis are regulated by the proteasomal system, which is critical for cell function and viability. Pluripotency of stem cells also relies on normal proteasomal activity that mitigates senescent phenotypes induced by intensive cell replications, as previously demonstrated in human bone marrow stromal cells. In this study, we investigated the role of proteasomes in self-renewal of neural progenitor cells (NPCs). Through bothin vivoandin vitroanalyses, we found that the expression of proteasomes was progressively decreased during aging. Likewise, proliferation and self-renewal of NPCs were also impaired in aged mice, suggesting that the down-regulation of proteasomes might be responsible for this senescent phenotype. Lowering proteasomal activity by loss-of-function manipulations mimicked the senescence of NPCs bothin vitroandin vivo; conversely, enhancing proteasomal activity restored and improved self-renewal in aged NPCs. These results collectively indicate that proteasomes work as a key regulator in promoting self-renewal of NPCs. This potentially provides a promising therapeutic target for age-dependent neurodegenerative diseases.
Phenotypic Characterization Analysis of Human Hepatocarcinoma by Urine Metabolomics Approach
Authors: Liang Qun , Liu Han , Wang Cong , Li Binbing
Published: January 2016

Hepatocarcinoma (HCC) is one of the deadliest cancers in the world and represents a significant disease burden. Better biomarkers are needed for early detection of HCC. Metabolomics was applied to urine samples obtained from HCC patients to discover noninvasive and reliable biomarkers for rapid diagnosis of HCC. Metabolic profiling was performed by LC-Q-TOF-MS in conjunction with multivariate data analysis, machine learning approaches, ingenuity pathway analysis and receiver-operating characteristic curves were used to select the metabolites which were used for the noninvasive diagnosis of HCC. Fifteen differential metabolites contributing to the complete separation of HCC patients from matched healthy controls were identified involving several key metabolic pathways. More importantly, five marker metabolites were effective for the diagnosis of human HCC, achieved a sensitivity of 96.5% and specificity of 83% respectively, could significantly increase the diagnostic performance of the metabolic biomarkers. Overall, these results illustrate the power of the metabolomics technology which has the potential as a non-invasive strategies and promising screening tool to evaluate the potential of the metabolites in the early diagnosis of HCC patients at high risk and provides new insight into pathophysiologic mechanisms.
Biofortified indica rice attains iron and zinc nutrition dietary targets in the field
Authors: Trijatmiko Kurniawan R. , Dueñas Conrado , Tsakirpaloglou Nikolaos , Torrizo Lina , Arines Felichi Mae , Adeva Cheryl , Balindong Jeanette , Oliva Norman , Sapasap Maria V. , Borrero Jaime , Rey Jessica , Francisco Perigio , Nelson Andy , Nakanishi Hiromi , Lombi Enzo , Tako Elad , Glahn Raymond P. , Stangoulis James , Chadha-Mohanty Prabhjit , Johnson Alexander A. T. , Tohme Joe , Barry Gerard , Slamet-Loedin Inez H.
Published: January 2016

More than two billion people are micronutrient deficient. Polished grains of popular rice varieties have concentration of approximately 2 μg g−1 iron (Fe) and 16 μg g−1 zinc (Zn). The HarvestPlus breeding programs for biofortified rice target 13 μg g−1 Fe and 28 μg g−1 Zn to reach approximately 30% of the estimated average requirement (EAR). Reports on engineering Fe content in rice have shown an increase up to 18 μg g−1 in glasshouse settings; in contrast, under field conditions, 4 μg g−1 was the highest reported concentration. Here, we report on selected transgenic events, field evaluated in two countries, showing 15 μg g−1 Fe and 45.7 μg g−1 Zn in polished grain. Rigorous selection was applied to 1,689 IR64 transgenic events for insert cleanliness and, trait and agronomic performances. Event NASFer-274 containing rice nicotianamine synthase (OsNAS2) and soybean ferritin (SferH-1) genes showed a single locus insertion without a yield penalty or altered grain quality. Endosperm Fe and Zn enrichment was visualized by X-ray fluorescence imaging. The Caco-2 cell assay indicated that Fe is bioavailable. No harmful heavy metals were detected in the grain. The trait remained stable in different genotype backgrounds.
A small molecule inhibitor of tropomyosin dissociates actin binding from tropomyosin-directed regulation of actin dynamics
Authors: Bonello Teresa T. , Janco Miro , Hook Jeff , Byun Alex , Appaduray Mark , Dedova Irina , Hitchcock-DeGregori Sarah , Hardeman Edna C. , Stehn Justine R. , Böcking Till , Gunning Peter W.
Published: January 2016

The tropomyosin family of proteins form end-to-end polymers along the actin filament. Tumour cells rely on specific tropomyosin-containing actin filament populations for growth and survival. To dissect out the role of tropomyosin in actin filament regulation we use the small molecule TR100 directed against the C terminus of the tropomyosin isoform Tpm3.1. TR100 nullifies the effect of Tpm3.1 on actin depolymerisation but surprisingly Tpm3.1 retains the capacity to bind F-actin in a cooperative manner. In vivo analysis also confirms that, in the presence of TR100, fluorescently tagged Tpm3.1 recovers normally into stress fibers. Assembling end-to-end along the actin filament is thereby not sufficient for tropomyosin to fulfil its function. Rather, regulation of F-actin stability by tropomyosin requires fidelity of information communicated at the barbed end of the actin filament. This distinction has significant implications for perturbing tropomyosin-dependent actin filament function in the context of anti-cancer drug development.
Blocking protein phosphatase 2A signaling prevents endothelial-to-mesenchymal transition and renal fibrosis: a peptide-based drug therapy
Authors: Deng Yuanjun , Guo Yanyan , Liu Ping , Zeng Rui , Ning Yong , Pei Guangchang , Li Yueqiang , Chen Meixue , Guo Shuiming , Li Xiaoqing , Han Min , Xu Gang
Published: January 2016

Endothelial-to-mesenchymal transition (EndMT) contributes to the emergence of fibroblasts and plays a significant role in renal interstitial fibrosis. Protein phosphatase 2A (PP2A) is a major serine/threonine protein phosphatase in eukaryotic cells and regulates many signaling pathways. However, the significance of PP2A in EndMT is poorly understood. In present study, the role of PP2A in EndMT was evaluated. We demonstrated that PP2A activated in endothelial cells (EC) during their EndMT phenotype acquisition and in the mouse model of obstructive nephropathy (i.e., UUO). Inhibition of PP2A activity by its specific inhibitor prevented EC undergoing EndMT. Importantly, PP2A activation was dependent on tyrosine nitration at 127 in the catalytic subunit of PP2A (PP2Ac). Our renal-protective strategy was to block tyrosine127 nitration to inhibit PP2A activation by using a mimic peptide derived from PP2Ac conjugating a cell penetrating peptide (CPP: TAT), termed TAT-Y127WT. Pretreatment withTAT-Y127WT was able to prevent TGF-β1-induced EndMT. Administration of the peptide to UUO mice significantly ameliorated renal EndMT level, with preserved density of peritubular capillaries and reduction in extracellular matrix deposition. Taken together, these results suggest that inhibiting PP2Ac nitration using a mimic peptide is a potential preventive strategy for EndMT in renal fibrosis.
Direct fabrication of 3D graphene on nanoporous anodic alumina by plasma-enhanced chemical vapor deposition
Authors: Zhan Hualin , Garrett David J. , Apollo Nicholas V. , Ganesan Kumaravelu , Lau Desmond , Prawer Steven , Cervenka Jiri
Published: January 2016

High surface area electrode materials are of interest for a wide range of potential applications such as super-capacitors and electrochemical cells. This paper describes a fabrication method of three-dimensional (3D) graphene conformally coated on nanoporous insulating substrate with uniform nanopore size. 3D graphene films were formed by controlled graphitization of diamond-like amorphous carbon precursor films, deposited by plasma-enhanced chemical vapour deposition (PECVD). Plasma-assisted graphitization was found to produce better quality graphene than a simple thermal graphitization process. The resulting 3D graphene/amorphous carbon/alumina structure has a very high surface area, good electrical conductivity and exhibits excellent chemically stability, providing a good material platform for electrochemical applications. Consequently very large electrochemical capacitance values, as high as 2.1 mF for a sample of 10 mm3, were achieved. The electrochemical capacitance of the material exhibits a dependence on bias voltage, a phenomenon observed by other groups when studying graphene quantum capacitance. The plasma-assisted graphitization, which dominates the graphitization process, is analyzed and discussed in detail.
Controlled growth of CH3NH3PbI3 nanowires in arrays of
open nanofluidic channels
Authors: Spina Massimo , Bonvin Eric , Sienkiewicz Andrzej , Náfrádi Bálint , Forró László , Horváth Endre
Published: January 2016

Spatial positioning of nanocrystal building blocks on a solid surface is a
prerequisite for assembling individual nanoparticles into functional devices. Here,
we report on the graphoepitaxial liquid-solid growth of nanowires of the
photovoltaic compound CH3NH3PbI3 in open
nanofluidic channels. The guided growth, visualized in real-time with a simple
optical microscope, undergoes through a metastable solvatomorph formation in polar
aprotic solvents. The presently discovered crystallization leads to the fabrication
of mm2-sized surfaces composed of perovskite nanowires having
controlled sizes, cross-sectional shapes, aspect ratios and orientation which have
not been achieved thus far by other deposition methods. The automation of this
general strategy paves the way towards fabrication of wafer-scale perovskite
nanowire thin films well-suited for various optoelectronic devices, e.g. solar
cells, lasers, light-emitting diodes and photodetectors.
Essential proteins and possible therapeutic targets of Wolbachia endosymbiont and development of FiloBase-a comprehensive drug target database for Lymphatic filariasis
Authors: Sharma Om Prakash , Kumar Muthuvel Suresh
Published: January 2016

Lymphatic filariasis (Lf) is one of the oldest and most debilitating tropical diseases. Millions of people are suffering from this prevalent disease. It is estimated to infect over 120 million people in at least 80 nations of the world through the tropical and subtropical regions. More than one billion people are in danger of getting affected with this life-threatening disease. Several studies were suggested its emerging limitations and resistance towards the available drugs and therapeutic targets for Lf. Therefore, better medicine and drug targets are in demand. We took an initiative to identify the essential proteins ofWolbachiaendosymbiont ofBrugia malayi, which are indispensable for their survival and non-homologous to human host proteins. In this current study, we have used proteome subtractive approach to screen the possible therapeutic targets forwBm. In addition, numerous literatures were mined in the hunt for potential drug targets, drugs, epitopes, crystal structures and expressed sequence tag (EST) sequences for filarial causing nematodes. Data obtained from our study were presented in a user friendly database named FiloBase. We hope that information stored in this database may be used for further research and drug development process against filariasis. URL:http://filobase.bicpu.edu.in.
Acute fluoxetine exposure alters crab anxiety-like behaviour, but not aggressiveness
Authors: Hamilton Trevor James , Kwan Garfield T. , Gallup Joshua , Tresguerres Martin
Published: January 2016

Aggression and responsiveness to noxious stimuli are adaptable traits that are ubiquitous throughout the animal kingdom. Like vertebrate animals, some invertebrates have been shown to exhibit anxiety-like behaviour and altered levels of aggression that are modulated by the neurotransmitter serotonin. To investigate whether this influence of serotonin is conserved in crabs and whether these behaviours are sensitive to human antidepressant drugs; the striped shore crab, Pachygrapsus crassipes, was studied using anxiety (light/dark test) and aggression (mirror test) paradigms. Crabs were individually exposed to acute doses of the selective serotonin reuptake inhibitor, fluoxetine (5 or 25 mg/L), commonly known as Prozac®, followed by behavioural testing. The high dose of fluoxetine significantly decreased anxiety-like behaviour but had no impact on mobility or aggression. These results suggest that anxiety-like behaviour is more sensitive to modulation of serotonin than is aggressiveness in the shore crab.
Development and Symbiosis Establishment in the Cnidarian Endosymbiosis Model Aiptasia sp.
Authors: Bucher Madeline , Wolfowicz Iliona , Voss Philipp A. , Hambleton Elizabeth A. , Guse Annika
Published: January 2016

Symbiosis between photosynthetic algae and heterotrophic organisms is widespread. One prominent example of high ecological relevance is the endosymbiosis between dinoflagellate algae of the genus Symbiodinium and reef-building corals, which typically acquire symbionts anew each generation during larval stages. The tropical sea anemone Aiptasia sp. is a laboratory model system for this endosymbiosis and, similar to corals, produces non-symbiotic larvae that establish symbiosis by phagocytosing Symbiodinium from the environment into the endoderm. Here we generate the first overview of Aiptasia embryogenesis and larval development and establish in situ hybridization to analyze expression patterns of key early developmental regulators. Next, we quantify morphological changes in developing larvae and find a substantial enlargement of the gastric cavity over time. Symbiont acquisition starts soon after mouth formation and symbionts occupy a major portion of the host cell in which they reside. During the first 14 days of development, infection efficiency remains constant while in contrast, localization of phagocytosed symbionts changes, indicating that the occurrence of functional phagocytosing cells may be developmentally regulated. Taken together, here we provide the essential framework to further develop Aiptasia as a model system for the analysis of symbiosis establishment in cnidarian larvae at the molecular level.
Experimental evidence for drought induced alternative stable states of soil moisture
Authors: Robinson David. A. , Jones Scott B. , Lebron Inma , Reinsch Sabine , Domínguez María T. , Smith Andrew R. , Jones Davey L. , Marshall Miles R. , Emmett Bridget A.
Published: January 2016

Ecosystems may exhibit alternative stable states (ASS) in response to environmental change. Modelling and observational data broadly support the theory of ASS, however evidence from manipulation experiments supporting this theory is limited. Here, we provide long-term manipulation and observation data supporting the existence of drought induced alternative stable soil moisture states (irreversible soil wetting) in upland Atlantic heath, dominated by Calluna vulgaris (L.) Hull. Manipulated repeated moderate summer drought and intense natural summer drought both lowered resilience resulting in shifts in soil moisture dynamics. The repeated moderate summer drought decreased winter soil moisture retention by ~10%. However, intense summer drought, superimposed on the experiment, that began in 2003 and peaked in 2005 caused an unexpected erosion of resilience and a shift to an ASS; both for the experimental drought manipulation and control plots, impairing the soil from rewetting in winter. Measurements outside plots, with vegetation removal, showed no evidence of moisture shifts. Further independent evidence supports our findings from historical soil moisture monitoring at a long-term upland hydrological observatory. The results herald the need for a new paradigm regarding our understanding of soil structure, hydraulics and climate interaction.
Mesenchymal stem cells maintain their defining stem cell characteristics after treatment with cisplatin
Authors: Nicolay Nils H. , Perez Ramon Lopez , Rühle Alexander , Trinh Thuy , Sisombath Sonevisay , Weber Klaus-Josef , Ho Anthony D. , Debus Jürgen , Saffrich Rainer , Huber Peter E.
Published: January 2016

Mesenchymal stem cells (MSCs) aid the regeneration of tissues damaged by treatment with cisplatin. However, the effects of this cytotoxic drug on the stem cells have been largely unknown. Here we demonstrate that human bone marrow-derived MSCs are relatively resistant to cisplatin treatment and show resistance levels comparable to these of differentiated fibroblasts. Cisplatin did not affect cellular morphology, adhesion or induction of apoptosis in MSCs. The potential for differentiation was preserved after exposure to cisplatin and established MSC surface markers were observed to be stably expressed irrespective of cisplatin treatment. Cytoskeletal rearrangements and high expression levels of individual heat shock proteins were detected in MSCs and may be partly responsible for the observed cisplatin resistance. The cisplatin-resistant phenotype of human MSCs supports the concept of further investigating these stem cells as a potential treatment option for cisplatin-induced tissue damage.
Automatic and objective oral cancer diagnosis by Raman spectroscopic detection of keratin with multivariate curve resolution analysis
Authors: Chen Po-Hsiung , Shimada Rintaro , Yabumoto Sohshi , Okajima Hajime , Ando Masahiro , Chang Chiou-Tzu , Lee Li-Tzu , Wong Yong-Kie , Chiou Arthur , Hamaguchi Hiro-o
Published: January 2016

We have developed an automatic and objective method for detecting human oral squamous cell carcinoma (OSCC) tissues with Raman microspectroscopy. We measure 196 independent Raman spectra from 196 different points of one oral tissue sample and globally analyze these spectra using a Multivariate Curve Resolution (MCR) analysis. Discrimination of OSCC tissues is automatically and objectively made by spectral matching comparison of the MCR decomposed Raman spectra and the standard Raman spectrum of keratin, a well-established molecular marker of OSCC. We use a total of 24 tissue samples, 10 OSCC and 10 normal tissues from the same 10 patients, 3 OSCC and 1 normal tissues from different patients. Following the newly developed protocol presented here, we have been able to detect OSCC tissues with 77 to 92% sensitivity (depending on how to define positivity) and 100% specificity. The present approach lends itself to a reliable clinical diagnosis of OSCC substantiated by the “molecular fingerprint” of keratin.