Magnetic-field induced melting of long-range magnetic order akin to Kitaev insulators in the metallic compound Tb5Si3.

There have been constant efforts to find 'exotic' quantum spin-liquid (QSL) materials. Some of the transition metal insulators dominated by the direction-dependent anisotropic exchange interaction ('Kitaev model' for honeycomb network of magnetic ions) are considered to be promising cases for the same. In such Kitaev insulators, QSL is achieved from the zero-field antiferromagnetic state by the application of magnetic-field, suppressing other exchange interactions responsible for magnetic order. Here, we show that the features attributable to long-range magnetic ordering of the intermetallic compound, Tb5Si3, (TN= 69 K), containing honey-comb network of Tb ions, are completely suppressed by a critical applied field,Hcr, in heat-capacity and magnetization data, mimicking the behavior of Kitaev physics candidates. The neutron diffraction patterns as a function ofHreveal that it is an incommensurate magnetic structure that gets suppressed, showing peaks arising from multiple wave vectors beyondHcr. Increasing magnetic entropy as a function ofHwith a peak in the magnetically ordered state is in support of some kind of magnetic disorder in a narrow field range afterHcr. Such a high-field behavior for a metallic heavy rare-earth system to our knowledge has not been reported in the past and therefore is intriguing.

Surface water temperature impacts on coastal wetland denitrification: Implications for river reconnection.

Louisiana, located in the southeast United States, is home to 40% of the continental US's coastal wetlands yet accounts for 80% of the nation's coastal wetland loss. This loss is generally attributed to decreased sediment supply, hydrologic alteration from levees, channelization, subsidence, sea-level rise, and wave and tidal induced marsh edge erosion. The Mid-Barataria Sediment Diversion is a US $1.3 billion coastal restoration project that will divert up to 2100 m3 s-1 of sediment-laden Mississippi River water directly into Barataria Basin. The influx of colder, nutrient-rich, springtime river water could negatively impact water quality of the receiving basin. We quantified the effects of colder, surface water temperature on the nitrate (NO3-) reduction rate in vegetated marsh and open water bay sediments. Colder water limited NO3- removal processes averaging 17.1 mg N m-2 d-1 in the range of 5-14 °C, before increasing almost 3-fold in the 20 °C treatments at 50.6 mg N m-2 d-1. Low N removal rates, especially near the project inflow where temperatures will be coldest will favor transport of NO3- further into Barataria Basin where eutrophic conditions could become expressed. These results will inform coastal managers around the world of the potential ecosystem response to coastal restoration aimed at river reconnection where colder waters enter warmer, shallow basins.

Towards reliable diagnostics of prostate cancer via breath.

Early detection of cancer is a key ingredient for saving many lives. Unfortunately, cancers of the urogenital system are difficult to detect at early stage. The existing noninvasive diagnostics of prostate cancer (PCa) suffer from low accuracy (< 70%) even at advanced stages. In an attempt to improve the accuracy, a small breath study of 63 volunteers representing three groups: (1) of 19 healthy, (2) 28 with PCa, (3) with 8 kidney cancer (KC) and 8 bladder cancer (BC) was performed. Ultrabroadband mid-infrared Fourier absorption spectroscopy revealed eight spectral ranges (SRs) that differentiate the groups. The resulting accuracies of supervised analyses exceeded 95% for four SRs in distinguishing (1) vs (2), three for (1) vs (3) and four SRs for (1) vs (2) + (3). The SRs were then attributed to volatile metabolites. Their origin and involvement in urogenital carcinogenesis are discussed.

Two simultaneous eumycetomas in different sites of same patient with discharge of black and white grains - First case in India.

Simultaneous double mycetoma is a rare presentation. Worldwide only three to four cases are found in literature. Here we report such an unusual case, to the best of our knowledge first documented case from India, where a 60 years old male farmer presented with double eumycetoma in different sites of same limb with discharge of black and white grains, which conventionally diagnosed as Madurella grisea from foot and Acremonium falciformi from buttock respectively.

Fate of particle-bound polycyclic aromatic hydrocarbons in the river-influenced continental margin of the northern Gulf of Mexico.

This study utilizes suspended particles and seafloor sediments collected from the northern Gulf of Mexico (GOM) continental margin to study the fate, transport, residence times and accumulation rates of particle-bound polycyclic aromatic hydrocarbons (PAHs). Total particulate-PAHs and particulate organic carbon (POC) varied between 0.9 and 7.0 ng/L, and 4-131 µg/L, respectively. Particulate-PAHs were positively correlated with POC, while both particulate-PAHs and POC were negatively correlated with salinity (P-value < 0.05). These results show that the river-derived particle influx and associated POC are important vectors for transport and fate of particulate-PAHs in the river-dominated northern GOM continental ecosystems. The composition of underlying seafloor sediment-PAHs were not correlated to the water column particulate-PAHs, which is attributed to re-mineralization, sediment resuspension/redistribution and different timescales of comparison. The 210Pb-derived residence time of particles and associated particulate-PAHs in water column varied between 2 and 39 days. Residence times of particulate-PAHs were significantly correlated with seafloor sediment-PAHs accumulation rates, shorter water column residence times leading to higher PAHs accumulation rates.

Increased progesterone receptor A expression in labouring human myometrium is associated with decreased promoter occupancy by the histone demethylase JARID1A.

Progesterone regulates female reproductive function predominantly through two nuclear progesterone receptors (PRs), PR-A and PR-B. During human parturition myometrial PR expression is altered to favour PR-A, which activates pro-labour genes. We have previously identified histone H3 lysine 4 trimethylation (H3K4me3) as an activator of myometrial PR-A expression at labour. To further elucidate the mechanisms regulating PR isoform expression in the human uterus at labour, we have (i) determined the methylation profile of the cytosine-guanine dinucleotides (CpG) island in the promoter region of the PR gene and (ii) identified the histone-modifying enzymes that target the H3K4me3 mark at the PR promoters in term and preterm human myometrial tissues obtained before and after labour onset. Bisulphite sequencing showed that despite overall low levels of PR CpG island methylation, there was a significant decrease in methylated CpGs with labour in both preterm (P < 0.05) and term (P < 0.01) groups downstream of the PR-B transcription start site. This methylation change was not associated with altered PR-B expression, but may contribute to the increase in PR-A expression with labour. Chromatin immunoprecipitation revealed that the histone methyltransferase, SET and MYND domain-containing protein 3 (SMYD3), bound to the PR gene at significantly higher levels at the PR-A promoter compared with the PR-B promoter (P < 0.010), with no labour-associated changes observed. The H3K4 demethylase, Jumonji AT-rich interactive domain 1A (JARID1A), also bound to the PR-A, but not to the PR-B promoter prior to term labour, and decreased significantly at the onset of labour (P = 0.014), providing a mechanism for the previously reported increase in H3K4me3 level and PR-A expression with labour. Our studies suggest that epigenetic changes mediated by JARID1A, SMYD3 and DNA methylation may be responsible, at least in part, for the functional progesterone withdrawal that precipitates human labour.

Unexplained antepartum stillbirth: a consequence of placental aging?

Unexplained antepartum stillbirth is a major obstetric health problem. Data demonstrate a rapid rise in risk per 1000 continuing pregnancies as gestation advances beyond 40 weeks. We review the evidence that such stillbirths are a consequence of aging related changes in the late gestation placenta. We suggest that the relatively small number of continuing pregnancies after 40 completed weeks means that negative effects of genes that produce aging affect so few pregnancies that polymorphisms in genes that produce these effects are retained in the population. Aging related changes likely represent a consequence of the damaging effects of oxidative stress, increased by cigarette smoking counteracted by the mitigating effects of oxidative defence pathways. The aging related changes are likely downstream from nutrient sensing units such as mTOR and include effects on production of telomerase and consequent shortening of telomere length. The late gestation changes occur in the context of increasing fetal growth and nutrient supply demands that can produce the rapid development of a mismatch between placental supply and fetal need resulting in fetal demise. Premature aging may also play an important role in antepartum stillbirth occurring earlier in pregnancy, especially in the context of growth restriction.

The endogenous retroviral envelope protein syncytin-1 inhibits LPS/PHA-stimulated cytokine responses in human blood and is sorted into placental exosomes.

OBJECTIVES: To examine whether syncytin-1 has immune regulatory functions and is carried by human placental exosomes. Further, to examine whether corticotropin-releasing hormone (CRH) can induce the production of syncytin-1. STUDY DESIGN: Human placental exosomes were isolated from placental explant, primary trophoblast and BeWo cell cultures. The presence of exosomes was confirmed by transmission electron microscopy and western blotting. Exosomal protein was probed with 3 separate antibodies targeting syncytin-1. Syncytin-1 immunosuppression was tested, using either a syncytin-1 recombinant ectodomain protein or a synthetic peptide with the human syncytin-1 immunosuppressive domain sequence, in an in vitro human blood culture system immune challenged with LPS or PHA. The inhibition of cytokine production by syncytin-1 was determined by ELISA of TNF-α, IFN-γ and CXCL10. BeWo cells were stimulated with CRH or vehicle for 24 h. mRNA and Protein was extracted from the cells for real-time PCR and western blotting analysis while exosomes were extracted from conditioned media for analysis by western blotting. RESULTS: Protein expression of syncytin-1 was detected in exosomes isolated from placental explants, primary trophoblast and BeWo cell cultures. Syncytin-1 recombinant ectodomain was also shown to inhibit the production of the Th1 cytokines TNF-α and IFN-γ as well as the chemokine, CXCL10 in human blood cells. Finally, this study showed that syncytin-1 can be stimulated by CRH. CONCLUSIONS: The presence of syncytin-1 in placental exosomes provides a mechanism for syncytin-1 to reach and interact with target cells of the maternal immune system and represents a novel mechanism of endogenous retroviral mediated immunosuppression that may be relevant for maternal immune tolerance.

Factors affecting cytotrophoblast cell viability and differentiation: Evidence of a link between syncytialisation and apoptosis.

A relationship between cytotrophoblast differentiation (syncytialisation) and apoptosis is hypothesised to exist, but has not been clearly determined. To address this, we explored the effects of cAMP, an inducer of syncytialisation, on human choriocarcinoma cell differentiation and viability under three different culture conditions related to diverse survival status: no serum, 10% fetal calf serum or 10% charcoal-stripped fetal calf serum. 8-Br-cAMP increased BeWo cell viability in culture media without serum, but viability was decreased in a dose- and time-dependent manner when serum was present. The appearance of apoptotic nuclei fragments were only observed when BeWo cells were cultured in media containing serum combined with 8-Br-cAMP treatment. In addition, the ratio of FasL to Fas expression following treatment with 8-Br-cAMP increased by 20-fold in 10% charcoal-stripped fetal calf serum media and 65-fold 10% fetal calf serum media, and activation of caspase-3 also required media with serum. The markers of syncytialisation (syncytin 1 expression and human chorionic gonadotropin secretion) were induced significantly by 8-Br-cAMP, and were higher in 10% fetal calf serum media than in 10% charcoal-stripped fetal calf serum media, than in the absence of serum. Syncytia formation was stimulated by 8-Br-cAMP and this required serum in the media. We now show that factors contained within serum are necessary for cAMP-stimulated cytotrophoblast differentiation, that syncytialisation involves apoptotic events, and that a lack of serum based factors could switch the cellular program away from differentiation.

G-1-activated membrane estrogen receptors mediate increased contractility of the human myometrium.

Estrogens are key mediators of increased uterine contractility at labor. We sought to determine whether membrane-associated estrogen receptors, such as the recently described seven-transmembrane receptor G protein-coupled receptor 30 (GPR30), mediated some of this effect. Using human myometrium obtained at term cesarean section before or after the onset of labor, we demonstrated the presence of GPR30 mRNA and protein using quantitative RT-PCR and Western blotting. GPR30 receptor was localized to the cell membrane and often colocalized with calveolin-1. Using the specific estrogen membrane receptor agonist G-1 and myometrial explants, we showed that membrane receptor activation led to phosphorylation of MAPK and the actin-modifying small heat shock protein 27. Using myometrial strips incubated with G-1 or vehicle we demonstrated that estrogen membrane receptor activation increased the myometrial contractile response to oxytocin. These data suggest that activation of the plasma membrane estrogen receptor GPR30 likely participates in the physiology of the human myometrium during pregnancy and identifies it as a potential target to modify uterine activity.

Estrogen increases smooth muscle expression of alpha2C-adrenoceptors and cold-induced constriction of cutaneous arteries.

Raynaud's phenomenon, which is characterized by intense cold-induced constriction of cutaneous arteries, is more common in women compared with men. Cold-induced constriction is mediated in part by enhanced activity of alpha(2C)-adrenoceptors (alpha(2C)-ARs) located on vascular smooth muscle cells (VSMs). Experiments were therefore performed to determine whether 17beta-estradiol regulates alpha(2C)-AR expression and function in cutaneous VSMs. 17beta-Estradiol (0.01-10 nmol/l) increased expression of the alpha(2C)-AR protein and the activity of the alpha(2C)-AR gene promoter in human cultured dermal VSMs, which was assessed following transient transfection of the cells with a promoter-reporter construct. The effect of 17beta-estradiol was associated with increased accumulation of cAMP and activation of the cAMP-responsive Rap2 GTP-binding protein. Transient transfection of VSMs with a dominant-negative mutant of Rap2 inhibited the 17beta-estradiol-induced activation of the alpha(2C)-AR gene promoter, whereas a constitutively active mutant of Rap2 increased alpha(2C)-AR promoter activity. The effects of 17beta-estradiol were inhibited by the estrogen receptor (ER) antagonist, ICI-182780 (1 micromol/l), and were mimicked by a cell-impermeable form of the hormone (estrogen:BSA) or by the selective ER-alpha receptor agonist 4,4',4'''-(4-propyl-[(1)H]-pyrazole-1,3,5-triyl)tris-phenol (PPT; 10 nmol/l) or the selective ER-beta receptor agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN; 10 nmol/l). Therefore, 17beta-estradiol increased expression of alpha(2C)-ARs by interacting with cell surface receptors to cause a cAMP/Rap2-dependent increase in alpha(2C)-AR transcription. In mouse tail arteries, 17beta-estradiol (10 nmol/l) increased alpha(2C)-AR expression and selectively increased the cold-induced amplification of alpha(2)-AR constriction, which is mediated by alpha(2C)-ARs. An estrogen-dependent increase in expression of cold-sensitive alpha(2C)-ARs may contribute to the increased activity of cold-induced vasoconstriction under estrogen-replete conditions.

Oscillatory magnetic anisotropy in one-dimensional atomic wires.

One-dimensional Co atomic wires grown on Pt(997) have been investigated by x-ray magnetic circular dichroism. Strong changes of the magnetic properties are observed as the system evolves from 1D- to 2D-like. The easy axis of magnetization, the magnetic anisotropy energy, and the coercive field oscillate as a function of the transverse width of the wires, in agreement with theoretical predictions for 1D metal systems.

Finite temperature magnetism in Gd: evidence against a Stoner behavior.

The temperature dependence of the rare-earth valence bands has been regarded as a realization of the Stoner behavior. The exchange splitting of the electronic states appears to scale as the magnetic order parameter for T

Ferromagnetism in one-dimensional monatomic metal chains.

Two-dimensional systems, such as ultrathin epitaxial films and superlattices, display magnetic properties distinct from bulk materials. A challenging aim of current research in magnetism is to explore structures of still lower dimensionality. As the dimensionality of a physical system is reduced, magnetic ordering tends to decrease as fluctuations become relatively more important. Spin lattice models predict that an infinite one-dimensional linear chain with short-range magnetic interactions spontaneously breaks up into segments with different orientation of the magnetization, thereby prohibiting long-range ferromagnetic order at a finite temperature. These models, however, do not take into account kinetic barriers to reaching equilibrium or interactions with the substrates that support the one-dimensional nanostructures. Here we demonstrate the existence of both short- and long-range ferromagnetic order for one-dimensional monatomic chains of Co constructed on a Pt substrate. We find evidence that the monatomic chains consist of thermally fluctuating segments of ferromagnetically coupled atoms which, below a threshold temperature, evolve into a ferromagnetic long-range-ordered state owing to the presence of anisotropy barriers. The Co chains are characterized by large localized orbital moments and correspondingly large magnetic anisotropy energies compared to two-dimensional films and bulk Co.

Antimicrobial activity of Alstonia macrophylla: a folklore of bay islands.

The methanolic crude and methanol-aqueous extract of Alstonia macrophylla leaves and n-butanol part of the crude extract showed antimicrobial activity against various strains of Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus faecalis, Escherichia coli, Proteus mirabilis, Trichophyton rubrum, Trichophyton mentagrophytes var. mentagrophytes and Microsporum gypseum. The minimum inhibitory concentration (MIC) values ranges from 64 to 1000 microg/ml for bacteria and 32-128 mg/ml for dermatophytes. However, the strains of Pseudomonas aeruginosa, Klebsiella sp. and Vibrio cholerae showed resistance against in vitro treatment of the extracts up to 2000 microg/ml concentration, while the two yeast species were resistant even at 128 mg/ml concentration. The stem bark extract prepared similarly was found to be less active compared to the leaves. Phytochemical study indicates that the crude extract contains tannins, flavonoids, saponins, sterols, triterpene and reducing sugars. Further fractionation and purification of n-butanol part of the extract showed the presence of beta-sitosterol, ursolic acid, beta-sitosterol glucoside and a mixture of minor compounds only detected in TLC.

Antibacterial activity of Bergenia ciliata rhizome.

The methanol extract of Bergenia ciliata (tested at 200--1000 microg/disc) showed a wide spectrum of concentration-dependent antibacterial activity.

Electronic band structure of Gd: a consistent description.

The dispersion of the Gd (5d6s)-valence bands has been investigated by means of spin- and angle-resolved photoemission. The spin analysis of various spectral features shows that their weak dispersion and unusual broadening is due to the photoelectron lifetime rather than to correlation induced band narrowing as previously proposed. These results resolve a long-standing discrepancy between theoretical and experimental descriptions of the rare earth band structure.

Evaluation of anti-inflammatory potential of Bergenia ciliata Sternb. rhizome extract in rats.

The methanol extract of the rhizome of Bergenia ciliata Sternb. (Saxifragaceae) has been evaluated for anti-inflammatory potential using two acute rat models (carrageenan- and serotonin (5-HT)-induced rat paw oedema) and a chronic rat model (cotton pouch-induced granuloma). Phenylbutazone (100 mg kg(-1)), a non-steroidal anti-inflammatory agent, was used as a standard. The methanol extract (100, 200 or 300 mg kg(-1)) exhibited significant (P < 0.05) anti-inflammatory activity in all the animal models. At 300 mg kg(-1) the methanol extract exhibited maximum inhibition of 32.4+/-2.89% in carrageenan-induced rat paw oedema while the standard showed an inhibition of 44.1+/-2.7% after 3 h of drug treatment. In the serotonin-induced rat paw oedema model, 300 mg kg(-1) methanol extract suppressed oedema by 45.33+/-2.09%, whereas the standard produced an inhibition of 53.5+/-4.3%. In the cotton pouch granuloma model the methanol extract inhibited significantly (P < 0.001) the granuloma weight in a dose-dependent manner. In this model, 300 mg kg(-1) extract produced a maximum inhibition of 31.4+/-1.09% in granuloma weight compared with 41.1+/-1.32% reduction in granuloma weight for the standard. The methanol extract of B. ciliata exhibited significant anti-inflammatory potential at the dose levels examined.

Study on the diuretic activity of Strychnos potatorum Linn. seed extract in albino rats.

Methanol extract of Strychnos potatorum Linn. seeds (SPSE) was evaluated for its diuretic activity in Wistar albino rats. The SPSE was administered at the graded doses of 200, 400, and 600 mg/kg body weight. The parameters which were taken into account during the experimental on each rat were: total urine volume (corrected for water intake during the test period), body weight before and after the experiment, and the concentration of sodium, potassium, and chloride ions in urine. The total urine volumes of the SPSE (600 mg/kg)-treated rats were evaluated nearly two and half fold then compared with the control (saline treated) group. Excretion of cations (sodium and potassium ions) and anions (chloride ions) also increased significantly with respect to the control group. The diuretic effect was comparable with that of the standard drug Furosemide. The increase of cations in the urine on treatment with Strychnospotatorum seed extract (SPSE) was dose-dependent. This effect supports the use of the Strychnos potatorum seeds as a diuretic in folk remedies.