Correlation between magnetic and micro-structural properties of low energy ion irradiated and un-irradiated Zn0.95Mn0.05O films

The emergence of strong ferromagnetism with significant reduction of antiferromagnetism by Ar ion irradiation induced micro-structural transformation of Mn ions.

Binary information propagation in circular magnetic nanodot arrays using strain induced magnetic anisotropy

Nanomagnetic logic has emerged as a potential replacement for traditional Complementary Metal Oxide Semiconductor (CMOS) based logic because of superior energy-efficiency (Salahuddin and Datta 2007 Appl. Phys. Lett. 90 093503, Cowburn and Welland 2000 Science 287 1466-68). One implementation of nanomagnetic logic employs shape-anisotropic (e.g. elliptical) ferromagnets (with two stable magnetization orientations) as binary switches that rely on dipole-dipole interaction to communicate binary information (Cowburn and Welland 2000 Science 287 1466-8, Csaba et al 2002 IEEE Trans. Nanotechnol. 1 209-13, Carlton et al 2008 Nano Lett. 8 4173-8, Atulasimha and Bandyopadhyay 2010 Appl. Phys. Lett. 97 173105, Roy et al 2011 Appl. Phys. Lett. 99 063108, Fashami et al 2011 Nanotechnology 22 155201, Tiercelin et al 2011 Appl. Phys. Lett. 99 , Alam et al 2010 IEEE Trans. Nanotechnol. 9 348-51 and Bhowmik et al 2013 Nat. Nanotechnol. 9 59-63). Normally, circular nanomagnets are incompatible with this approach since they lack distinct stable in-plane magnetization orientations to encode bits. However, circular magnetoelastic nanomagnets can be made bi-stable with a voltage induced anisotropic strain, which provides two significant advantages for nanomagnetic logic applications. First, the shape-anisotropy energy barrier is eliminated which reduces the amount of energy required to reorient the magnetization. Second, the in-plane size can be reduced (∼20 nm) which was previously not possible due to thermal stability issues. In circular magnetoelastic nanomagnets, a voltage induced strain stabilizes the magnetization even at this size overcoming the thermal stability issue. In this paper, we analytically demonstrate the feasibility of a binary 'logic wire' implemented with an array of circular nanomagnets that are clocked with voltage-induced strain applied by an underlying piezoelectric substrate. This leads to an energy-efficient logic paradigm orders of magnitude superior to existing CMOS-based logic that is scalable to dimensions substantially smaller than those for existing nanomagnetic logic approaches. The analytical approach is validated with experimental measurements conducted on dipole coupled Nickel (Ni) nanodots fabricated on a PMN-PT (Lead Magnesium Niobate-Lead Titanate) sample.

An Exploratory Statistical Analysis of the effect of Demographic risk factors on uterine Cervical squamous Intraepithelial Lesion

Pap Smear test (Pap test), a cytological screening test of the cervical squamous intraepithelial lesion (SIL) is a widely accepted screening technique for uterine cervical cancer (UCC). UCC is a major canter burden for Indian women. In this article, we present an in-depth exploratory analysis on various statistical relationships between the Pap test and a set of demographic risk factors, such as Age, Age at consummation of marriage [ACM], parity [PAR] etc. The data had been collected from the Calcutta Medical College Hospital (CMCH) on 308 subjects. Major statistical findings in this article include a possible Age dependent association between PAR and the SIL-status. It seems that a high value of parity at a relatively young age is an important risk factor for developing SIL in future. This finding may be useful in relating to overall female helath issues in developing and underdeveloped country-senario.

AMS (2000) Subject Classification: Primary 62-07, 62Pl0, 92C60, Secondary 92C50, 62F03, 62F10.

Super-giant magnetoresistance at room-temperature in copper nanowires due to magnetic field modulation of potential barrier heights at nanowire-contact interfaces

We have observed a super-giant (∼10 000 000%) negative magnetoresistance at 39 mT field in Cu nanowires contacted with Au contact pads. In these nanowires, potential barriers form at the two Cu/Au interfaces because of Cu oxidation that results in an ultrathin copper oxide layer forming between Cu and Au. Current flows when electrons tunnel through, and/or thermionically emit over, these barriers. A magnetic field applied transverse to the direction of current flow along the wire deflects electrons toward one edge of the wire because of the Lorentz force, causing electron accumulation at that edge and depletion at the other. This lowers the potential barrier at the accumulated edge and raises it at the depleted edge, causing a super-giant magnetoresistance at room temperature.

Molecular signature of extended spectrum β-lactamase producing Klebsiella pneumoniae isolated from bovine milk in eastern and north-eastern India

The present study reports on 23 extended spectrum β-lactamase producing Klebsiella pneumoniae (KP), isolated from milk samples (n=340) of healthy cows (n=129) and cows with subclinical (n=159) and clinical (n=52) mastitis, from three different states of India viz. West Bengal, Jharkhand and Mizoram. Seven of them were AmpC type β-lactamase producers, as well. The ESBL producing KP were significantly (P=0.006, χ2=10.04, df=2) and more frequently detected in milk samples of mastitic cows than healthy ones. The β-lactamase genes - blaCTX-M, blaTEM and blaSHV were detected in 19, 8 and 3 isolates, respectively. In all but one CTX-M positive isolates, the genetic platform - ISEcp1-blaCTX-M-orf477 was detected. Ten of the isolates carried plasmid mediated quinolone resistance gene - qnrS and 1 isolate possessed qnrB. Again 11 of them were found to have sulfonamide resistance gene - sul1 and 12 possessed class I integron. Sequencing of the class 1 integron revealed the presence of dfrA12/dfrA17 and aadA2/aadA5 gene cassettes conferring resistance to trimethoprim and aminoglycosides, respectively. All the isolates, characterized by enterobacterial repetitive intergenic consensus (ERIC) PCR, yielded distinct fingerprinting profile. However, most of the isolates from Jharkhand were clustered along with two isolates each from West Bengal and Mizoram indicating their clonal relatedness even though isolated from geographically different areas. Isolation of ESBL producing KP from bovine milk samples implies its public health significance; as such pathogens may enter the human food chain causing severe health hazards.

Impact Modification of Isotactic Polypropylene with Ethylene-Propylene Diene Monomer Rubber

The present work was done to improve the impact property of isotactic polypropylene (PP), especially at low temperatures, by incorporating ethylene propylene diene monomers (EPDM). This was done by ensuring compatibility between the two polymers with phase modifiers polyethylene grafted with maleic anhydride (PE-g-MA) and initiator dicumyl peroxide (DCP). In addition, attempts were also made to understand the fundamentals of impact toughening as well as fracture toughness, and to correlate the results with that of morphological evidences obtained from scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. Varying the ratios of all blend composition, mechanical properties were studied. It was observed that as the rubber fraction increased, the impact property as well as fracture toughness increased. All these tests also showed promising results when PE-g-MA was added, leading to more improvement in all the mechanical properties including increase in crystallite size. It had shown plasticization effect on the compositions, which could be further confirmed by differential scanning calorimetry (DSC) compared to the uncompatibilized ones. But when DCP was added, it behaved like an initiator which directly reacted with the PP matrix, decreasing the molecular weight of the blend with decreasing size of the crystallites.

Investigation of Fe doped ZnO thin films by X-ray absorption spectroscopy

XANES and EXAFS studies have been carried out on Fe doped ZnO thin films having different Fe doping concentration ranging from 1% to 10% and the observed ferromagnetism in the samples is explained in the light of XANES and EXAFS observations.

Molecular characterization and antibiotic susceptibility pattern of caprine Shiga toxin producing-Escherichia coli (STEC) isolates from India

The present study was conducted to detect the occurrence, serotype, genotype, phylogenetic relationship and antimicrobial resistance pattern of STEC from healthy goats of West Bengal, India. From the 125 faecal samples collected from healthy goats, 245 isolates were identified as Escherichia coli. The E. coli harbouring any gene for Shiga toxins (stx 1/stx 2) was detected in 36 (14.7%) of the 245 E. coli isolates. These STEC strains belonged to 22 different serogroups (O2, O5, O20, O21, O22, O25, O41, O44, O45, O60, O71, O76, O84, O85, O87, O91, O103, O112, O113, O120, O156, and O158) and three were untypeable. The stx 1 and stx 2 was detected in 26 (72.2%) and 21 (58.3%) of Shiga toxin producing-E. coli (STEC) isolates, respectively. Further, E. coli harbouring eaeA only (Enteropathogenic E. coli) and ehxA was detected in 22 (61.1%) and 28 (77.7%) isolates, respectively. Whereas the saa was present in 8 (22.2%) E. coli isolates. The subtyping of the 26 E. coli strains possessing stx 1 showed that 73.% (19/26) of these isolates were positive for stx 1C subtype. Of the 21 isolates with the stx 2 gene, 42.8% (9/21) were positive for stx 2C, and 38.1% (8/21) were positive for stx 2d gene. The phylogenetic analysis of STEC strains after RAPD reveals eight major clusters. However, no serogroup specific cluster was observed. Resistance was observed most frequently to erythromycin (80.5%), amikacin (52.7%), cephalothin (50%), kanamycin (41.6%), neomycin (36.1%) and gentamycin (36.1%) and less frequently to norfloxacin (2.7%), enrofloxacin (2.7%), and ciprofloxacin (2.7%). Multidrug resistance was observed in eleven STEC isolates.

Multifaceted core–shell nanoparticles: superparamagnetism and biocompatibility

A facile method for the synthesis of Ni_coreAg_shell and Ni_coreAu_shell nanoparticles with suitable surface modification for the latter has been demonstrated with potential applications.

Giant increase in the metal-enhanced fluorescence of organic molecules in nanoporous alumina templates and large molecule-specific red/blue-shift of the fluorescence peak

The fluorescence of organic fluorophore molecules is enhanced when they are placed in contact with certain metals (Al, Ag, Cu, Au, etc.) whose surface plasmon waves couple into the radiative modes of the molecules and increase the radiative efficiency. Here, we report a hitherto unknown size dependence of this metal-enhanced fluorescence (MEF) effect in the nanoscale. When the molecules are deposited in nanoporous anodic alumina films with exposed aluminum at the bottom of the pores, they form organic nanowires standing on aluminum nanoparticles whose plasmon waves have much larger amplitudes. This increases the MEF strongly, resulting in several orders of magnitude increase in the fluorescence intensity of the organic fluorophores. The increase in intensity shows an inverse superlinear dependence on nanowire diameter because the nanowires also act as plasmonic "waveguides" that concentrate the plasmons and increase the coupling of the plasmons with the radiative modes of the molecules. Furthermore, if the nanoporous template housing the nanowires has built-in electric fields due to space charges, a strong molecule-specific red- or blue-shift is induced in the fluorescence peak owing to a renormalization of the dipole moment of the molecule. This can be exploited to detect minute amounts of target molecules in a mixture using their optical signature (fluorescence) despite the presence of confounding background signals. It can result in a unique new technology for biosensing and chemical sensing.

Endometrial cancer in morbidly obese women: do racial disparities affect surgical or survival outcomes?

OBJECTIVE

Endometrial cancer mortality disproportionately affects black women and whether greater prevalence of obesity plays a role in this disparity is unknown. We examine the effect of race on post-surgical complications, length of stay, and mortality specifically in a morbidly obese population.

METHODS

Black and white women with endometrial cancer diagnosed from 1996 to 2012 were identified from the University Pathology Group database in Detroit, Michigan, and records were retrospectively reviewed to obtain clinicopathological, demographic, and surgical information. Analysis was limited to those with a body mass index of 40kg/m(2) or greater. Differences in the distribution of variables by race were assessed by chi-squared tests and t-tests. Kaplan-Meier and Cox regression analyses were performed to examine factors associated with mortality.

RESULTS

97 white and 89 black morbidly obese women were included in this analysis. Black women were more likely to have type II tumors (33.7% versus 15.5% of white women, p-value=0.003). Hypertension was more prevalent in black women (76.4% versus 58.8%, p-value=0.009), and they had longer hospital stays after surgery despite similar rates of open vs minimally invasive procedures and lymph node dissection (mean days=5.4) compared to whites (mean days=3.5, p-value=0.036). Wound infection was the most common complication (16.5% in whites and 14.4% in blacks, p-value=0.888). Blacks were more likely to suffer other complications, but overall the proportions did not differ by race. In univariate analyses, black women had higher risk of endometrial cancer-related death (p-value=0.090). No racial differences were noted in adjusted survival analyses.

CONCLUSION

A more complete investigation, incorporating socio-demographic factors, is warranted to understand the effects of morbid obesity and race on endometrial cancer.

A facile method for the synthesis of Co-core Au-shell nanohybrid

Heterostructured Co–Au core–shell nanoparticles have been synthesized by reducing AuCl₄⁻ ions on cobalt nanoparticles after a minor but effective modification of cobalt surface by an amine.

Transfusion of 28-day-old leucoreduced or non-leucoreduced stored red blood cells induces an inflammatory response in healthy dogs

BACKGROUND AND OBJECTIVES

Studies in mice suggest that rapid transfusions of red blood cells (RBCs), refrigerator stored for longer durations, induce a pro-inflammatory cytokine response. Studies in human neonates confirm these findings; however, to date, adult human studies have failed to replicate these findings. We used healthy research dogs to begin to examine the factors affecting the cytokine response to transfusion.

MATERIALS AND METHODS

In a prospective study, healthy dogs were randomized for two autologous packed RBC transfusions after 7 (i.e. 'fresh') and 28 (i.e. 'old') days of storage, or after 28 and 7 days of storage, with or without prestorage leucoreduction (LR).

RESULTS

No significant differences were observed between LR and non-LR transfusions for all circulating analytes measured following transfusion. A pro-inflammatory cytokine response, exemplified by monocyte chemoattractant protein-1, was observed 6 h after only old RBC transfusions, irrespective of infusion rate (P < 0·001). This response was accompanied by increased neutrophil counts (P < 0·001) and decreased platelet counts (P < 0·001).

CONCLUSION

In healthy dogs, old RBC transfusions induce inflammation, which is unaffected by infusion rate.