Photophysical Properties of S = 5/2 Zigzag-1D (2-Bromoethylammonium)3MnBr5 Antiferromagnet

It has been challenging to design multifunctional lead-free organic-inorganic hybrid halides that can exhibit fascinating magnetic and photoluminescence properties since the dimensionality of the compounds has a contrasting impact on them. In this context, our newly synthesized compound (2-bromoethylammonium)3MnBr5 (BEAMBr) crystallizes in the monoclinic C2/c space group with corner-sharing zigzag 1D chains of MnBr6 distorted octahedra. Intriguingly, it exhibits a long-range antiferromagnetic ordering at low temperature (∼2.5 K) along with a typical low-dimensional broad magnetic susceptibility hump. The magnetic properties modeled by the exact diagonalization approach indicate strong intrachain and weak interchain interactions with J1 = -50.1 K, J2 = -13.0 K, and J' = -1.25 K, respectively, suggesting excellent one-dimensionality. In addition, BEAMBr displays orange-red emission with a photoluminescence quantum yield of 15.2%. Interestingly, electron-phonon coupling was observed in this soft distorted compound with coupling strength γLO = 128.3 meV, confirmed from the analysis of temperature-dependent emission line width broadening and Raman spectra.

High-pressure synthesis and magnetic properties of tetragonal R2BaCuO5 (R = Sm and Eu)

We report the experimental discovery of a new structural phase of well-known orthorhombic R ₂BaCuO₅ (R = Sm and Eu), exhibiting a tetragonal crystal structure with space group P4∕mbm. The high-pressure tetragonal phase is isostructural with the brown phase R ₂BaCuO₅ (R = La, Pr, and Nd). In this structure, the Cu ions form an isolated square planar environment, contrary to the orthorhombic phase, where the Cu ions are located in a distorted square pyramid. Magnetization and specific heat measurements reveal the long-range antiferromagnetic order of the Cu²⁺ and/or Sm³⁺ moments for the Sm-sample, with the magnetic specific heat accounting for only 35% of the magnetic entropy. Interestingly, the Eu-sample remains paramagnetic down to the lowest temperature. The high Curie-Weiss temperature of -140 K and magnetic entropy of 3% of the expected value indicates that the system is highly frustrated. We estimated the isothermal entropy change and investigated the magnetocaloric effect for Eu₂BaCuO₅, and the maximum entropy change detected at a field of 70 kOe at 3 K reaches 5.6 J kg^-1K^-1.

Halogen Bond Induced Structural and Photophysical Properties Modification in Organic-Inorganic Hybrid Manganese Halides

The role of halogen bonding in organic-inorganic hybrid (OIH) halides was seldom investigated despite its potential to enhance the stability of the compound. In this context, we have synthesized (2-methylbenzimidazolium)MnCl₃(H₂O)·H₂O (compound 1) crystallizing in a monoclinic space group P2₁/c with a 1D infinite chain of edge shared Mn octahedra. In contrast, the chloro-substituted derivative (5-chloro-2-methylbenzimidazolium)₂MnCl₄ (compound 2) exhibits 0D Mn tetrahedra with a triclinic P1̅ structure. This structural modification from 1D Mn octahedra to 0D Mn tetrahedra involves a unique type-II halogen bonding between organic chlorine (C-Cl) and inorganic chloride (Cl-Mn) ions. Compound 1 exhibits red emission, whereas compound 2 demonstrates dual-band emission, resulting from energy transfer from the organic amine to Mn centers. To rationalize this interesting modulation in structure and photophysical properties, the role of halogen bonding is explored in terms of quantitative electron density analysis and intermolecular interaction energies.

Elucidating Structure-Property Correlation in Perovskitoid and Antiperovskite Piperidinium Manganese Chloride

In the world of semiconductors, organic-inorganic hybrid (OIH) halide perovskite is a new paradigm. Recently, a zealous effort has been made to design new lead-free perovskite-like OIH halides, such as perovskitoids and antiperovskites, for optoelectronic applications. In this context, we have synthesized a perovskitoid compound (Piperidinium)MnCl₃ (compound 1) crystallizing in an orthorhombic structure with infinite one-dimensional (1D) chains of MnCl₆ octahedra. Interestingly, this compound shows switchable dielectric property governed by an order-disorder structural transition. By controlling the stoichiometry of piperidine, we have synthesized an antiperovskite (Piperidinium)₃Cl[MnCl₄] (compound 2), the inverse analogue of a perovskite, consisting of zero-dimensional (0D) MnCl₄ tetrahedra. This type of organic-inorganic hybrid antiperovskite halide is unique and scarce. Such a dissimilarity in lattice dimensionality and Mn²⁺ ion coordination ensues fascinating photophysical and magnetic properties. Compound 1 exhibits red emission with a photoluminescence quantum yield (PLQY) of ∼28%. On the other hand, the 0D antiperovskite compound 2 displays green emission with a higher PLQY of 54.5%, thanks to the confinement effect. In addition, the dimensionality of the compounds plays a vital role in the exchange interaction. As a result, compound 1 shows an antiferromagnetic ground state, whereas compound 2 is paramagnetic down to 1.8 K. This emerging structure-property relationship in OIH manganese halides will set the platform for designing new perovskites and antiperovskites.

Electron-Phonon Coupling Mediated Self-Trapped-Exciton Emission and Internal Quantum Confinement in Highly Luminescent Zero-Dimensional (Guanidinium)6Mn3X12 (X = Cl and Br)

We report a large Stokes shift and broad emission band in a Mn-based organic-inorganic hybrid halide, (guanidinium)₆Mn₃Br₁₂ [GuMBr], consisting of trimeric units of distorted MnBr₆ octahedra representing a zero-dimensional compound with a liquid like crystalline lattice. Analysis of the photoluminescence (PL) line width and Raman spectra reveals the effects of electron-phonon coupling, suggestive of the formation of Frenkel-like bound excitons. These bound excitons, regarded as the self-trapped excitons (STEs), account for the large Stokes shift and broad emission band. The excited-state dynamics was studied using femtosecond transient absorption spectroscopy, which confirms the STE emission. Further, this compound is highly emissive with a PL quantum yield of ∼50%. With chloride ion incorporation, we observe enhancement of the emissive properties and attribute it to the effects of intrinsic quantum confinement. Localized electronic states in flat bands lining the gap and their strong coupling with phonons are confirmed with first-principles calculations.

Spin-glass behavior in Li3NiCuBiO6: a two-dimensional distorted honeycomb-lattice

We report a detailed experimental study on the structural and magnetic properties of Li₃NiCuBiO₆by means of various characterization techniques. It crystallizes into a monoclinic crystal structure composed of a layered magnetic honeycomb lattice along thec-axis. The existence of glassy state below 4 K is indicated by dc and ac susceptibility measurements. Magnetic contribution to the total heat capacity also peaks around the freezing temperature, and its linear temperature dependence backs our claim of a glassy state in the compound. The calculated magnetic entropy unveils that only ∼26% of the total entropy is released for the system (S=3/2), and a tremendous amount of spin entropy is still retained in the system. Further, analysis of the frequency-dependent freezing temperature with the help of power law confirms the presence of a spin glass state. Moreover, the appearance of magnetic memory and relaxation effect below freezing temperature manifest the development of the system via a large number of intermediate metastable states. All these measurements confirm the spin-glass behavior of the compound. We consider the presence of different magnetic atoms in honeycomb lattice as the main driving factor for the spin-glass ground state.

Zero-Dimensional (Piperidinium)2MnBr4: Ring Puckering-Induced Isostructural Transition and Strong Electron-Phonon Coupling-Mediated Self-Trapped Exciton Emission

We report on the synthesis, structure, and photophysical properties of a lead-free organic-inorganic hybrid halide, (Piperidinium)₂MnBr₄ (PipMBr). It crystallizes in a monoclinic P2₁/n structure, with isolated MnBr₄ tetrahedra representing a zero-dimensional compound. It undergoes a reversible isostructural transition at 422/417 K in the heating/cooling cycle owing to the hydrogen-bonding rearrangement mediated by ring puckering of piperidinium cations. This compound exhibits green emission with a photoluminescence quantum yield of 51%. Interestingly, strong electron-longitudinal optical phonon coupling with γ_LO of 237 meV is evidenced from the broadening of the temperature-dependent emission linewidth and the Raman spectrum. Such strong electron-phonon coupling and a relatively low Debye temperature (137 K) suggest the self-trapped exciton emission in this compound.

Chromatin Accessibility Analysis from Fresh and Cryopreserved Human Ovarian Follicles

Understanding how gene regulatory elements influence ovarian follicle development has important implications in clinically relevant settings. This includes understanding decreased fertility with age and understanding the short-lived graft function commonly observed after ovarian tissue cryopreservation and subsequent autologous transplantation as a fertility preservation treatment. The Assay for Transposase Accessible Chromatin by sequencing (ATAC-seq) is a powerful tool to identify distal and proximal regulatory elements important for activity-dependent gene regulation and hormonal and environmental responses such as those involved in germ cell maturation and human fertility. Original ATAC protocols were optimized for fresh cells, a major barrier to implementing this technique for clinical tissue samples which are more often than not frozen and stored. While recent advances have improved data obtained from stored samples, this technique has yet to be applied to human ovarian follicles, perhaps due to the difficulty in isolating follicles in sufficient quantities from stored clinical samples. Further, it remains unknown whether the process of cryopreservation affects the quality of the data obtained from ovarian follicles. Here, we generate ATAC-seq data sets from matched fresh and cryopreserved human ovarian follicles. We find that data obtained from cryopreserved samples are of reduced quality but consistent with data obtained from fresh samples, suggesting that the act of cryopreservation does not significantly affect biological interpretation of chromatin accessibility data. Our study encourages the use of this method to uncover the role of chromatin regulation in a number of clinical settings with the ultimate goal of improving fertility.

Krüppel-like factor-4 and Krüppel-like factor-2 are important regulators of joint tissue cells and protect against tissue destruction and inflammation in osteoarthritis

OBJECTIVES

Analysing expression patterns of Krüppel-like factor (KLF) transcription factors in normal and osteoarthritis (OA) human cartilage, and determining functions and mechanisms of KLF4 and KLF2 in joint homoeostasis and OA pathogenesis.

METHODS

Experimental approaches included human joint tissues cells, transgenic mice and mouse OA model with viral KLF4 gene delivery to demonstrate therapeutic benefit in structure and pain improvement. Mechanistic studies applied global gene expression analysis and chromatin immunoprecipitation sequencing (ChIP-seq).

RESULTS

Several KLF genes were significantly decreased in OA cartilage. Among them, KLF4 and KLF2 were strong inducers of cartilage collagen genes and Proteoglycan-4. Cartilage-specific deletion of Klf2 in mature mice aggravated severity of experimental OA. Transduction of human chondrocytes with Adenovirus (Ad) expressing KLF4 or KLF2 enhanced expression of major cartilage extracellular matrix (ECM) genes and SRY-box transcription factor-9, and suppressed mediators of inflammation and ECM-degrading enzymes. Ad-KLF4 and Ad-KLF2 enhanced similar protective functions in meniscus cells and synoviocytes, and promoted chondrocytic differentiation of human mesenchymal stem cells. Viral KLF4 delivery into mouse knees reduced severity of OA-associated changes in cartilage, meniscus and synovium, and improved pain behaviours. ChIP-seq analysis suggested that KLF4 directly bound cartilage signature genes. Ras-related protein-1 signalling was the most enriched pathway in KLF4-transduced cells, and its signalling axis was involved in upregulating cartilage ECM genes by KLF4 and KLF2.

CONCLUSIONS

KLF4 and KLF2 may be central transcription factors that increase protective and regenerative functions in joint tissue cells, suggesting that KLF gene transfer or molecules upregulating KLFs are therapeutic candidates for OA.

ATRX promotes heterochromatin formation to protect cells from G-quadruplex DNA-mediated stress

ATRX is a tumor suppressor that has been associated with protection from DNA replication stress, purportedly through resolution of difficult-to-replicate G-quadruplex (G4) DNA structures. While several studies demonstrate that loss of ATRX sensitizes cells to chemical stabilizers of G4 structures, the molecular function of ATRX at G4 regions during replication remains unknown. Here, we demonstrate that ATRX associates with a number of the MCM replication complex subunits and that loss of ATRX leads to G4 structure accumulation at newly synthesized DNA. We show that both the helicase domain of ATRX and its H3.3 chaperone function are required to protect cells from G4-induced replicative stress. Furthermore, these activities are upstream of heterochromatin formation mediated by the histone methyltransferase, ESET, which is the critical molecular event that protects cells from G4-mediated stress. In support, tumors carrying mutations in either ATRX or ESET show increased mutation burden at G4-enriched DNA sequences. Overall, our study provides new insights into mechanisms by which ATRX promotes genome stability with important implications for understanding impacts of its loss on human disease.

ATRX is a chromatin remodeling protein, which loss has been associated to replication stress, DNA damage, and DNA repair failures that drive genome instability. Here the authors reveal that ATRX protects genomic integrity at G4-containing regions by maintaining these regions in a closed heterochromatic state.

The CdTiO3/BaTiO3 superlattice interface from first principles

The oxide interface has been studied extensively in the past decades and exhibits different physical properties from the constituent bulks. Using first-principles electronic structure calculations, we investigated the interface of CdTiO₃/BaTiO₃ (CTO/BTO) superlattice with ferroelectric BaTiO₃. In this case, the conduction bands of CdTiO₃ are composed of Cd-5s orbitals with low electron effective mass and nondegenerate dispersion, and thus expected to have high mobility. We predicted a controllable conductivity at the interface, and further analyzed how the polarization direction and strength affect the conductivity. We also explored the relationship between two components: thickness and polarization. Intriguingly, the total polarization in CTO/BTO might be even larger than that of ferroelectric bulk BaTiO₃. Therefore, we found a way to maximize the superlattice polarization by increasing the fraction of the CdTiO₃ layers, based on the interesting dependence of the total polarization and CTO/BTO ratio.

Differential contribution of p300 and CBP to regulatory element acetylation in mESCs

Background

The transcription coactivators CREB binding protein (CBP) and p300 are highly homologous acetyltransferases that mediate histone 3 lysine 27 acetylation (H3K27ac) at regulatory elements such as enhancers and promoters. Although in most cases, CBP and p300 are considered to be functionally identical, both proteins are indispensable for development and there is evidence of tissue-specific nonredundancy. However, characterization of chromatin and transcription states regulated by each protein is lacking.

Results

In this study we analyze the individual contribution of p300 and CBP to the H3K27ac landscape, chromatin accessibility, and transcription in mouse embryonic stem cells (mESC). We demonstrate that p300 is the predominant H3K27 acetyltransferase in mESCs and that loss of acetylation in p300KD mESCs is more pronounced at enhancers compared to promoters. While loss of either CBP or p300 has little effect on the open state of chromatin, we observe that distinct gene sets are transcriptionally dysregulated upon depletion of p300 or CBP. Transcriptional dysregulation is generally correlated with dysregulation of promoter acetylation upon depletion of p300 (but not CBP) and appears to be relatively independent of dysregulated enhancer acetylation. Interestingly, both our transcriptional and genomic analyses demonstrate that targets of the p53 pathway are stabilized upon depletion of p300, suggesting an unappreciated view of the relationship between p300 and p53 in mESCs.

Conclusions

This genomic study sheds light on distinct functions of two important transcriptional regulators in the context of a developmentally relevant cell type. Given the links to both developmental disorders and cancer, we believe that our study may promote new ways of thinking about how these proteins function in settings that lead to disease.

Genome-Wide Association Study of Apparent Treatment-Resistant Hypertension in the CHARGE Consortium: The CHARGE Pharmacogenetics Working Group

BACKGROUND

Only a handful of genetic discovery efforts in apparent treatment-resistant hypertension (aTRH) have been described.

METHODS

We conducted a case-control genome-wide association study of aTRH among persons treated for hypertension, using data from 10 cohorts of European ancestry (EA) and 5 cohorts of African ancestry (AA). Cases were treated with 3 different antihypertensive medication classes and had blood pressure (BP) above goal (systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg) or 4 or more medication classes regardless of BP control (nEA = 931, nAA = 228). Both a normotensive control group and a treatment-responsive control group were considered in separate analyses. Normotensive controls were untreated (nEA = 14,210, nAA = 2,480) and had systolic BP/diastolic BP < 140/90 mm Hg. Treatment-responsive controls (nEA = 5,266, nAA = 1,817) had BP at goal (<140/90 mm Hg), while treated with one antihypertensive medication class. Individual cohorts used logistic regression with adjustment for age, sex, study site, and principal components for ancestry to examine the association of single-nucleotide polymorphisms with case-control status. Inverse variance-weighted fixed-effects meta-analyses were carried out using METAL.

RESULTS

The known hypertension locus, CASZ1, was a top finding among EAs (P = 1.1 × 10-8) and in the race-combined analysis (P = 1.5 × 10-9) using the normotensive control group (rs12046278, odds ratio = 0.71 (95% confidence interval: 0.6-0.8)). Single-nucleotide polymorphisms in this locus were robustly replicated in the Million Veterans Program (MVP) study in consideration of a treatment-responsive control group. There were no statistically significant findings for the discovery analyses including treatment-responsive controls.

CONCLUSION

This genomic discovery effort for aTRH identified CASZ1 as an aTRH risk locus.

Ursolic acid modulates MMPs, collagen-I, α-SMA, and TGF-β expression in isoproterenol-induced myocardial infarction in rats

In the present study, the modulatory effect of ursolic acid (UA) on cardiac fibrosis and mitochondrial and lysosomal enzymes activity in isoproterenol-induced myocardial infarction (MI) in rats were examined. Isoproterenol hydrochloride (ISO; 85 mg/kg body weight) was administered subcutaneously for first two consecutive days. ISO-induced MI in rats significantly decreased the activities of mitochondrial tricarboxylic acid cycle enzymes and respiratory chain enzymes while increased the activities of lysosomal glycohydrolases and cathepsins. The expression of matrix metalloproteinase 2 (MMP-2), MMP-9, collagen type I, α-smooth muscle actin (α-SMA), and transforming growth factor-β (TGF-β) were upregulated in ISO-induced MI in rats. UA administration to rats showed increased activities of mitochondrial tricarboxylic acid cycle enzymes and respiratory chain enzymes and decreased activities of lysosomal glycohydrolases and cathepsins in ISO-induced rats. Furthermore, expression of MMP-2, MMP-9, collagen type I, α-SMA, and TGF-β downregulated in UA-administered rats. Thus, our results demonstrate that UA has an anti-fibrotic effect and attenuates the mitochondrial and lysosomal dysfunction in ISO-induced MI in rats.

Synthesis, Structure, and Physical Properties of the Polar Magnet DyCrWO6

It has recently been reported that the ordered aeschynite-type polar ( Pna2₁) magnets RFeWO₆ (R = Eu, Tb, Dy, Y) exhibit type II multiferroic properties below T_N ∼ 15-18 K. Herein, we report a comprehensive investigation of the isostructural oxide DyCrWO₆ and compare the results with those of DyFeWO₆. The cation-ordered oxide DyCrWO₆ crystallizes in the same polar orthorhombic structure and undergoes antiferromagnetic ordering at T_N = 25 K. Contrary to DyFeWO₆, only a very weak dielectric anomaly and magnetodielectric effects are observed at the Néel temperature and, more importantly, there is no induced polarization at T_N. Furthermore, analysis of the low-temperature neutron diffraction data reveals a collinear arrangement of Cr spins but a noncollinear Dy-spin configuration due to single-ion anisotropy. We suggest that the collinear arrangement of Cr spins may be responsible for the absence of electric polarization in DyCrWO₆. A temperature-induced magnetization reversal and magnetocaloric effects are observed at low temperatures.

Coexistence of long-range cycloidal order and spin-cluster glass state in the multiferroic BaYFeO4

We report the presence of spin glass state below the cycloidal spin ordering in the multiferroic BaYFeO₄. This compound is known to crystallize in an orthorhombic structure with a centrosymmetric space group Pnma and exhibits two successive antiferromagnetic phase transitions. Upon cooling, it undergoes a spin density wave (SDW)-like antiferromagnetic ordering at T _N1 ~ 48 K and a cycloidal ordering at T _N2 ~ 35 K. Using dc magnetic memory effect and magnetization relaxation studies, we have shown that this oxide undergoes a reentrant spin glass transition below T ^* ~ 17 K. Our analysis suggests the presence of spin clusters in the glassy state. The coexistence of spin-cluster glass and long-range cycloidal ordered states results in an exchange bias effect at 2 K. The origin of the glassy state has been attributed to freezing of some Fe³⁺ moments, which do not participate in the long-range ordering.

New rare earth hafnium oxynitride perovskites with photocatalytic activity in water oxidation and reduction

RHfO₂N perovskites with R = La, Nd, and Sm represent the first examples of quaternary hafnium oxynitrides and are active as photocatalysts in the overall water splitting reaction.

Abstract 2453: Chromatin remodeling genes are frequently somatically altered in cervical carcinomas

Introduction: Cervical cancer is responsible for 15% of all deaths due to cancer in women worldwide. There is a need to identify somatic mutations driving this cancer in order to facilitate development of novel therapeutic strategies.

Experimental procedures: We analyzed whole exome sequencing data from 430 cervical carcinomas. The data were derived from a combination of our previously published work (Ojesina et al. Nature 2014; Chung et al, Int J Cancer 2015), and publicly available data generated by the Cancer Genome Atlas (TCGA). The Mutect2.0 and MutSig2CV algorithms were used to identify somatic mutations and significantly mutated genes (SMGs) respectively. Copy number alterations were analyzed using the GISTIC algorithm.

Findings: Based on MutSig2CV false discovery rate threshold of 0.1, we identified MLL3 (19%) and MLL2 (13%) as novel significantly mutated genes (SMGs) in cervical cancer. In addition, other chromatin modifying genes including EP300 (12%) and ARID1A (7%) were confirmed as SMGs. Further investigation of genes that did not meet the threshold revealed that 228 of 430 (53%) of cervical tumors harbored at least one somatic mutation in a chromatin modifying gene. These include genes in the myeloid/lymphoid or mixed-lineage leukemia (MLL) family (28%), lysine (K)-specific demethylase (KDM) family (23%), AT rich interactive domain (ARID) family (13%), SWI/SNF related, matrix associated, actin dependent regulator of chromatin (SMARC) family (8%) and histone cluster 1 (HIST1) family (4%).

Conclusions: We have demonstrated that a majority of cervical cancers harbor somatic mutations in chromatin remodeling genes. This novel finding was facilitated by the larger sample size derived from combining multiple datasets, and may have diagnostic and therapeutic implications in cervical cancer.

Citation Format: Akinyemi Ojesina, Aishwarya Sundaresan, Vinodh Srinivasasainagendra, Hemant Tiwari, Warner Huh. Chromatin remodeling genes are frequently somatically altered in cervical carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2453. doi:10.1158/1538-7445.AM2017-2453

Quantification of phenolics in Syzygium cumini seed and their modulatory role on tertiary butyl-hydrogen peroxide-induced oxidative stress in H9c2 cell lines and key enzymes in cardioprotection

The study quantified the major phenolics in different fractions of Syzygium cumini seeds and evaluated their cardioprotective efficacy. Gallic acid, ellagic acid, cinnamic acid, quercetin, syringic acid and ferulic acid were the major polyphenols present in different fractions of Syzygium cumini seeds. The cardioprotective effect of Syzygium cumini seed fractions in modulating angiotensin converting enzyme (ACE), HMG-CoA reductase, LDL oxidation and tertiary butyl hydrogen peroxide (TBHP) induced oxidative stress in H9c2 cardiac cell lines were investigated. Syzygium cumini effectively attenuated the cellular oxidative stress in H9c2 cardiomyoblasts. These fractions possessed inhibitory potential against ACE, HMG-CoA reductase and LDL oxidation. Molecular docking studies of the predominant polyphenols with ACE and HMG-CoA proteins revealed the binding interactions of these compounds, thus confirming their modulation of activity. The present study demonstrated the cardioprotective efficacy of Syzygium cumini seed fractions which can be attributed to the presence of phenolic acids and flavonoids.

Migration of mitochondrial DNA in the nuclear genome of colorectal adenocarcinoma

Background

Colorectal adenocarcinomas are characterized by abnormal mitochondrial DNA (mtDNA) copy number and genomic instability, but a molecular interaction between mitochondrial and nuclear genome remains unknown. Here we report the discovery of increased copies of nuclear mtDNA (NUMT) in colorectal adenocarcinomas, which supports link between mtDNA and genomic instability in the nucleus. We name this phenomenon of nuclear occurrence of mitochondrial component as numtogenesis. We provide a description of NUMT abundance and distribution in tumor versus matched blood-derived normal genomes.

Methods

Whole-genome sequence data were obtained for colon adenocarcinoma and rectum adenocarcinoma patients participating in The Cancer Genome Atlas, via the Cancer Genomics Hub, using the GeneTorrent file acquisition tool. Data were analyzed to determine NUMT proportion and distribution on a genome-wide scale. A NUMT suppressor gene was identified by comparing numtogenesis in other organisms.

Results

Our study reveals that colorectal adenocarcinoma genomes, on average, contains up to 4.2-fold more somatic NUMTs than matched normal genomes. Women colorectal tumors contained more NUMT than men. NUMT abundance in tumor predicted parallel abundance in blood. NUMT abundance positively correlated with GC content and gene density. Increased numtogenesis was observed with higher mortality. We identified YME1L1, a human homolog of yeast YME1 (yeast mitochondrial DNA escape 1) to be frequently mutated in colorectal tumors. YME1L1 was also mutated in tumors derived from other tissues. We show that inactivation of YME1L1 results in increased transfer of mtDNA in the nuclear genome.

Conclusions

Our study demonstrates increased somatic transfer of mtDNA in colorectal tumors. Our study also reveals sex-based differences in frequency of NUMT occurrence and that NUMT in blood reflects NUMT in tumors, suggesting NUMT may be used as a biomarker for tumorigenesis. We identify YME1L1 as the first NUMT suppressor gene in human and demonstrate that inactivation of YME1L1 induces migration of mtDNA to the nuclear genome. Our study reveals that numtogenesis plays an important role in the development of cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0420-6) contains supplementary material, which is available to authorized users.

Synthetically tuned structural variations in CePdxGe2−x(x = 0.21, 0.32, 0.69) towards diverse physical properties

Three structural variations of CePd_xGe_2−xwith versatile properties were synthesized by varying the Pd : Ge ratio.

Is CH3NH3PbI3 Polar?

In view of the continued controversy concerning the polar/nonpolar nature of the hybrid perovskite system, CH3NH3PbI3, we report the first investigation of a time-resolved pump-probe measurement of the second harmonic generation efficiency as well as using its more traditional form as a sensitive probe of the absence/presence of the center of inversion in the system both in its excited and ground states, respectively. Our results clearly show that SHG efficiency, if nonzero, is below the limit of detection, strongly indicative of a nonpolar or centrosymmetric structure. Our results on the same samples, based on temperature dependent single crystal X-ray diffraction and P-E loop measurements, are entirely consistent with the above conclusion of a centrosymmetric structure for this compound in all three phases, namely the high temperature cubic phase, the intermediate temperature tetragonal phase and the low temperature orthorhombic phase. It is important to note that all our experimental probes are volume averaging and performed on bulk materials, suggesting that basic material properties of CH3NH3PbI3 are consistent with a centrosymmetric, nonpolar structure.

Influence of natural and synthetic antioxidants on the degradation of Soybean oil at frying temperature

The effect of several natural and synthetic antioxidants to retard the formation of polar compounds and thermo-oxidation at prolonged frying temperatures was studied. Antioxidants, including butyl hydroxyl toluene (BHT), ter-butyl hydroxyquinone (TBHQ), α- and γ-tocopherols, tocopherol mixture (α, β, γ and δ), sesamol, β-sitosterol, β-sitostanol, γ-oryzanol, curcumin, rosemary extract and sucrose acetate isobutyrate (SAIB) were tested in refined soybean oil without added any additives recovered from refinery. Rosemary extract and SAIB were showed a considerable effect on both polar compound formation and secondary oxidation. These compounds increased the oxidative stability of oil for more than 30 % compared to conventional synthetic antioxidants. Oils treated with SAIB showed higher color retention after 6 h heating compared to the oils added with BHT, TBHQ and tocopherols. Curcumin, sesamol and γ-oryzanol showed higher antioxidant potential compared to other antioxidants. Preliminary results obtained from this study have clearly demonstrated that SAIB and rosemary extracts are more commercially viable antioxidants to increase the stability of frying oils.

Observation of Room Temperature Ferromagnetism in InN Nanostructures

The room temperature ferromagnetic behavior of InN nanostructures grown by molecular beam epitaxy (MBE) is explored by means of magnetization measurements. The saturation magnetization and remanent magnetization are found to be strongly dependent on the size of the nanostructures. This suggests that the ferromagnetism is essentially confined to the surface of the nanostructures due to the possible defects. Raman spectroscopy shows the existence of indium vacancies which could be the source of ferromagnetic ordering in InN nanostructures.

Influence of rare earth doping on the structural and electro-magnetic properties of SmFeAsO0.7F0.3 iron pnictide

The effect of Gd and Ce doping on the structural and transport properties of the (Sm,RE)FeAsO_0.7F_0.3 superconductor.

Rare earth (RE – Ce, Gd) modified Nd1−xRExFeAsO0.7F0.3 superconductor with enhanced magneto-transport properties

The influence of rare earth (RE – Ce, Gd) doping at the Nd site in the NdFeAsO_0.7F_0.3 superconductor wherein Ce and Gd have ionic radii in the order Ce > Nd > Gd is investigated.

Enhanced thermal oxidation stability of reduced graphene oxide by nitrogen doping

Nitrogen-doped reduced graphene oxide (N-doped RGO) samples with a high level of doping, up to 13 wt. %, have been prepared by annealing graphene oxide under a flow of pure ammonia. The presence of nitrogen within the structure of RGO induces a remarkable increase in the thermal stability against oxidation by air. The thermal stability is closely related with the temperature of synthesis and the nitrogen content. The combustion reaction of nitrogen in different coordination environments (pyridinic, pyrrolic, and graphitic) is analyzed against a graphene fragment (undoped) from a thermodynamic point of view. In agreement with the experimental observations, the combustion of undoped graphene turns out to be more spontaneous than when nitrogen atoms are present.

The absence of ferroelectric polarization in layered and rock-salt ordered NaLnMnWO6 (Ln = La, Nd, Tb) perovskites

Time dependence of current in response to the first and second negative electric field pulses indicating the absence of ferroelectricity in NaNdMnWO₆.

Effect of co-substitution of nitrogen and fluorine in BaTiO3 on ferroelectricity and other properties

BaTiO3, with both nitrogen and fluorine substituted for oxygen, has been prepared and the properties of the doped material with the composition BaTiO2:8N0:1F0:1 have been studied. The color of the sample changes to light green on doping, accompanying a broad visible absorption band with its edge at 2.5 eV. The first-order ferroelectric transition changes to a broad transition on doping along with a decrease in the dielectric constant. We have examined the local structure, electronic structure and polar lattice dynamical properties of N and F co-substituted BaTiO3 using first-principles density functional theory-based calculations and derived the mechanism of the diffuse ferroelectric transition observed here with a broad peak in the temperature-dependent dielectric response. The calculated Born charges clearly reveal a strong disparity in the interaction of N, O and F with Ti: N being the most ferro-active, with a highly anomalous charge, and F being the least active, with an almost nominal charge. This originates from an electronic structure in which the top-most valence band is constituted of the 2p states of N, while the electronic states of F lie deep in the energy band, resulting in a local structure with short covalent Ti–N and long ionic Ti–F bonds. Disorder in these hetero ferro-active anions leads to a relaxor-like diffuse phase transition and a reduction in polarization. Calculations confirm the reduction of 0.65 eV in the bandgap of BaTiO3, which changes from indirect to direct type.

In vitro synergistic activity of diketopiperazines alone and in combination with amphotericin B or clotrimazole against Candida albicans

The synergistic anticandidal activity of three diketopiperazines [cyclo-(L-Pro-L-Leu) (1), cyclo-(D-Pro-L-Leu) (2), and cyclo-(D-Pro-L-Tyr) (3)] purified from a Bacillus sp. N strain associated with entomopathogenic nematode Rhabditis (Oscheius) in combination with amphotericin B and clotrimazole was investigated using the macrodilution method. The minimum inhibitory concentration and minimum fungicidal concentration of the diketopiperazines was compared with that of the standard antibiotics. The synergistic anticandidal activities of diketopiperazines with amphotericin B or clotrimazole were assessed using the checkerboard and time-kill methods. The results of the present study showed that the combined effects of diketopiperazines with amphotericin B or clotrimazole predominantly recorded synergistic (<0.5). Time-kill study showed that the growth of the Candida was completely attenuated after 12-24 h of treatment with 50:50 ratios of diketopiperazines and antibiotics. These results suggest that diketopiperazines combined with antibiotics may be microbiologically beneficial and not antagonistic. These findings have potential implications in delaying the development of resistance as the anticandidal effect is achieved with lower concentrations of both drugs (diketopiperazines and antibiotics). The cytotoxicity of diketopiperazines was also tested against two normal human cell lines (L231 lung epithelial and FS normal fibroblast) and no cytotoxicity was recorded for diketopiperazines up to 200 μg/mL. The in vitro synergistic activity of diketopiperazines with antibiotics against Candida albicans is reported here for the first time.

Multiferroic and Magnetoelectric Oxides: The Emerging Scenario

Multiferroics were considered to be rare because magnetism and ferroelectricity require entirely different criteria for the materials. Several multiferroic oxides have, however, been discovered in the past few years by virtue of novel operating mechanisms, the most effective one being ferroelectricity driven by magnetism itself. Many such oxides where the magnetic and electric order parameters interact also exhibit magnetoelectric or magnetodielectric properties. In this Perspective, properties of manganites, ferrites, and other monophasic multiferroic oxides with spin-induced electric polarization are described. Multiferroic properties arising from charge ordering are examined. The present status of BiMnO3, which is an unusual example of a ferromagnetic-ferroelectric, is presented. Recent findings suggest that it is likely that many more multiferroic and magnetoelectric oxide materials exhibiting magnetically induced ferroelectricity will be found in the future.

Inhibitory effect of Terminalia chebula Retz. fruit extracts on digestive enzyme related to diabetes and oxidative stress

Terminalia chebula fruit extracts were prepared sequentially with hexane, ethyl acetate, methanol and methanol-water (70:30) and tested for their α-glucosidase inhibitory and antioxidant potential. The study resulted in the formulation of an extract with high α-glucosidase inhibitory potential (IC(50) 0.19 ± 0.03 µg mL(-1)) enriched with hydrolysable tannins. Also, each of the extract was chemically characterized by reversed-phase high-performance liquid chromatography on the basis of their marker compounds chebulagic acid, chebulinic acid and corilagin in order to give explanation to the significant activity shown by the extracts. The antioxidant potential of the highly active extract was evaluated in the cellular level also using superoxide dismutase, glutathione S-transferase and induced oxidative stress assays. The results indicated the possibility of using the extract as a nutraceutical health supplement in the management of type 2 diabetes.

Near-room-temperature colossal magnetodielectricity and multiglass properties in partially disordered La2NiMnO6

We report magnetic, dielectric, and magnetodielectric responses of the pure monoclinic bulk phase of partially disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this compound is an intrinsically multiglass system with a large magnetodielectric coupling (8%-20%) over a wide range of temperatures (150-300 K). Specifically, our results establish a unique way to obtain colossal magnetodielectricity, independent of any striction effects, by engineering the asymmetric hopping contribution to the dielectric constant via the tuning of the relative-spin orientations between neighboring magnetic ions in a transition-metal oxide system. We discuss the role of antisite (Ni-Mn) disorder in emergence of these unusual properties.

Mössbauer spectroscopic study of spin reorientation in Mn-substituted yttrium orthoferrite

The first-order spin-reorientation transition in the Mn-substituted yttrium orthoferrites, YFe(1-x)Mn(x)O(3) (x = 0.1, 0.15 and 0.2), has been investigated using (57)Fe Mössbauer spectroscopy. Owing to its large anisotropy, substitution of Mn(3+) ions in YFeO(3) induces a spin-reorientation transition from the low-temperature antiferromagnetic state to a high-temperature weak ferromagnetic state. With increasing x, the spin-reorientation transition temperature (T(SR)) increases whereas the Néel temperature (T(N)) decreases. Analysis of the Mössbauer spectra unambiguously confirms the occurrence of spin reorientation relative to crystal axes. At a given temperature, the mean hyperfine field decreases with the increasing Mn concentration. The variation of canting angle with temperature for YFe(0.85)Mn(0.15)O(3) has been estimated.