Microbial acceleration of aerobic pyrite oxidation at circumneutral pH

Pyrite (FeS₂ ) is the most abundant sulfide mineral on Earth and represents a significant reservoir of reduced iron and sulfur both today and in the geologic past. In modern environments, oxidative transformations of pyrite and other metal sulfides play a key role in terrestrial element partitioning with broad impacts to contaminant mobility and the formation of acid mine drainage systems. Although the role of aerobic micro-organisms in pyrite oxidation under acidic-pH conditions is well known, to date there is very little known about the capacity for aerobic micro-organisms to oxidize pyrite at circumneutral pH. Here, we describe two enrichment cultures, obtained from pyrite-bearing subsurface sediments, that were capable of sustained cell growth linked to pyrite oxidation and sulfate generation at neutral pH. The cultures were dominated by two Rhizobiales species (Bradyrhizobium sp. and Mesorhizobium sp.) and a Ralstonia species. Shotgun metagenomic sequencing and genome reconstruction indicated the presence of Fe and S oxidation pathways in these organisms, and the presence of a complete Calvin-Benson-Bassham CO₂ fixation system in the Bradyrhizobium sp. Oxidation of pyrite resulted in thin (30-50 nm) coatings of amorphous Fe(III) oxide on the pyrite surface, with no other secondary Fe or S phases detected by electron microscopy or X-ray absorption spectroscopy. Rates of microbial pyrite oxidation were approximately one order of magnitude higher than abiotic rates. These results demonstrate the ability of aerobic microbial activity to accelerate pyrite oxidation and expand the potential contribution of micro-organisms to continental sulfide mineral weathering around the time of the Great Oxidation Event to include neutral-pH environments. In addition, our findings have direct implications for the geochemistry of modern sedimentary environments, including stimulation of the early stages of acid mine drainage formation and mobilization of pyrite-associated metals.

Modulation of CD11c+ lung dendritic cells in respect to TGF-β in experimental pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a deadly, progressive lung disease with very few treatment options till now. Bleomycin-induced pulmonary fibrosis (BIPF) is a commonly used mice model in IPF research. TGF-β1 has been shown to play a key role in pulmonary fibrosis (PF). Dendritic cell (DC) acts as a bridge between innate and adaptive immune systems. The coexistence of chronic inflammation sustained by mature DCs with fibrosis suggests that inflammatory phenomenon has key importance in the pathogenesis of pulmonary fibrosis. Here, we investigated the modulation of DCs phenotypic maturation, accumulation in lung tissue, and expression of other lung DC subsets in respect to TGF-β in PF. First, we established BIPF model in mice and blocked TGF-β expression by the use of inhibitor SB431542. Accumulation of lung CD11c+ DCs is significantly higher in both inflammatory and fibrotic phases of the disease but that percentages got reduced in the absence of TGF-β. TGF-β initiates up-regulation of costimulatory molecules CD86 and CD80 in the inflammatory phases of the disease but not so at fibrotic stage. Expression of lung DC subset CD11c+CD103+ is significantly increased in inflammatory phase and also in fibrotic phase of BIPF. Blocking of TGF-β causes decreased expression of CD11c+CD103+ DCs. Another important lung DC subset CD11c+CD11b+ expression is suppressed by the absence of TGF-β after bleomycin administration. CD11c+CD103+ DCs might have anti-inflammatory as well as anti-fibrotic nature in PF. All these data demonstrate differential modulation of CD11c+ lung DCs by TGF-β in experimental PF.

Superconducting gap structure in the electron doped BiS2-based superconductor

The influence of electron doping on semimetallic SrFBiS₂ has been investigated by means of resistivity, zero and transverse  -  field (ZF/TF) muon spin relaxation/rotation (μSR) experiments. SrFBiS₂ is semimetallic in its normal state and small amounts of La doping results in bulk superconductivity at 2.8 K, at ambient pressure. The temperature dependence of the superfluid density as determined by TF-μSR can be best modelled by an isotropic s  -  wave type superconducting gap. We have estimated the magnetic penetration depth [Formula: see text] nm, superconducting carrier density [Formula: see text] carriers m^-3 and effective-mass enhancement m ^*  =  1.558 m _e. Additionally, there is no clear sign of the occurrence of spontaneous internal magnetic fields below [Formula: see text], which implies that the superconducting state in this material can not be categorized by the broken time-reversal symmetry which is in agreement with the previous theoretical prediction.

Kondo lattice heavy fermion behavior in CeRh2Ga2

The physical properties of an intermetallic compound CeRh₂Ga₂ have been investigated by magnetic susceptibility [Formula: see text], isothermal magnetization M(H), heat capacity [Formula: see text], electrical resistivity [Formula: see text], thermal conductivity [Formula: see text] and thermopower S(T) measurements. CeRh₂Ga₂ is found to crystallize with CaBe₂Ge₂-type primitive tetragonal structure (space group P4/nmm). No evidence of long range magnetic order is seen down to 1.8 K. The [Formula: see text] data show paramagnetic behavior with an effective moment [Formula: see text]/Ce indicating Ce³⁺ valence state of Ce ions. The [Formula: see text] data exhibit Kondo lattice behavior with a metallic ground state. The low-T [Formula: see text] data yield an enhanced Sommerfeld coefficient [Formula: see text] mJ/mol K² characterizing CeRh₂Ga₂ as a moderate heavy fermion system. The high-T [Formula: see text] and [Formula: see text] show an anomaly near 255 K, reflecting a phase transition. The [Formula: see text] suggests phonon dominated thermal transport with considerably higher values of Lorenz number L(T) compared to the theoretical Sommerfeld value L ₀.

Interface phonon modes in the [AlN/GaN]20 and [Al0.35Ga0.65N/Al0.55Ga0.45N]20 2D multi-quantum well structures

The observation of interface (IF) phonon modes in the recorded Raman spectra of c-plane oriented [AlN/GaN]₂₀ and [Al_0.35Ga_0.65N/Al_0.55Ga_0.45N]₂₀ multi-quantum well (MQW) structures grown via plasma assisted molecular beam epitaxy is reported. The nominal shift in the IF phonon mode of E₁ symmetry for [Al_0.35Ga_0.65N/Al_0.55Ga_0.45N]₂₀ compared to that of the [AlN/GaN]₂₀ MQW structure is understood on the basis of change in dielectric constants (ε_m) of the surrounding medium. The presence of buffer layers in [Al_0.35Ga_0.65N/Al_0.55Ga_0.45N]₂₀ MQW over a sapphire substrate is also understood by characterizing the IF phonon mode of A₁ symmetry. The observed IF phonon modes in the spectra are attributed to the relaxation of Raman selection rules away from the Brillouin zone centre because of the breakdown of the translational symmetry of surface potential due to the presence of the periodic interfaces and surface modulations in the superlattice structures of MQWs. The corresponding required edge lengths (L) of 2D plates, for the observation of the breakdown of the surface potential, are computed from the simulated dispersion relation curve of IF modes. The integral multiples of uniformly distributed platelets, originated due to the horizontal uneven irregularities on the surface of superlattices, are matched with the calculated L values.

miR-216b suppresses breast cancer growth and metastasis by targeting SDCBP

Breast cancer is the most deadly cancer among women and the second leading cause of cancer death worldwide. Treatment effectiveness is complicated with tumor invasiveness/drug resistance. To tailor treatments more effectively to individual patients, it is important to define tumor growth and metastasis at molecular levels. SDCBP is highly overexpressed and associated with a strikingly poor prognosis in breast cancer. However the post transcriptional regulation of SDCBP overexpression remains to be an unexplored area. Our study reveals that miR-216b directly regulates SDCBP expression by binding to its 3'UTR region. miR-216b is a tumor suppressive miRNA and it is underexpressed during metastatic breast cancer. Consequently, overexpression of miR-216b resulted in decreased proliferation, migration and invasion in BC cell lines by modulating the expression of SDCBP. Inhibition of miR-216b divergent the tumor suppressive role by inducing the growth proliferation, migration and invasion in vitro. There is therefore a negative correlation between the expression of miR-216b and its target gene SDCBP in the BC tissue samples as well as cell lines. Simultaneous expression of miR-216b and SDCBP rescued the growth, migration and invasion effect suggesting that tumor suppressive action of miR-216b may be directly mediated by SDCBP. In summary, the study identifies miR-216b as a regulator of SDCBP expression in breast cancer which can potentially be targeted for developing newer therapies for the effective treatment of this killer disease.

Outcome Analysis of Fernandez Osteotomy in Malunited Extra-Articular Fractures of Distal Radius

Deformity of wrist is very common after mal union of extra articular fractures over distal end of Radius. It causes limitation of movements too in different directions with or without pain. Deformity may be treated by different types of corrective osteotomy. We treated cases of this type of malunion with Fernandez osteotomy. This study is to observe the amount of correction and recovery of functional status in patients with malunited distal radius fractures treated with Fernandez osteotomy. This is a prospective study. We treated 10 cases of malunited radius with Fernandez osteotomy from February 2013 to October 2014 in the Departments of Orthopaedics, Medical College and Hospital, Kolkata, India. There were six males and four females with mean age of thirty years (with range from twenty to forty years. Indications for surgical intervention include pain and functional deficit severe enough to interfere significantly with daily activities. Radius is exposed through distal dorsal radial incision and radial osteotomy done two and half centimetre proximal to the wrist joint and after achieving correction; gap is filled with iliac bone graft and fixed with contoured distal radius T-plate. Follow up was for an average one year and three months. Results were excellent in one, satisfactory in four cases, good in four cases and bad in one case. Fernandez osteotomy is valuable option for correction of malunited distal radius fracture especially in young demanding patients.

Complexation thermodynamics of diglycolamide with f-elements: solvent extraction and density functional theory analysis

Optimized complexes of Lu³⁺ with TMDGA in 1 : 1, 1 : 2 and 1 : 3 stoichiometric ratios and plots of theoretically calculated stepwise binding energy.

YnfA , a SMR family efflux pump is abundant in Escherichia coli isolates from urinary infection

A quantitative study was undertaken to determine the expression level of different efflux pumps in multi-drug-resistant (MDR) Escherichia coli isolates from urinary infection. We have determined the presence of different efflux pumps and measured the expression level of tolC, mdfA, norE and ynfA genes among 48 isolates by quantitative real-time PCR. The expression level of tolC and ynfA was constantly high and observed among 75-80% of isolates, whereas mdfA and norE were expressed occasionally. Our findings suggest that ynfA, a new SMR efflux pump gene family member increases the antibiotics' resistance in E. coli.