A clone of elusive parents: gonadotroph adenoma-female type

A 69-year-old woman presented with visual disturbance. Perimetry testing revealed a bitemporal hemianopia. Brain MRI demonstrated a 2.2-cm gadolinium-enhancing pituitary mass. Previously she had been treated for hypothyroidism, hypertension, and dyslipidemia. She had hyperprolactinemia. Endoscopic transsphenoidal debulking improved her visual field defects. Histology showed a chromophobic adenoma. Electron microscopy showed elongated, polar cells with long, slender processes. The small uniform secretory granules were peripherally disposed, collecting heavily within cell processes. Based on electron microscopical characteristics the tumor is consistent with an ACTH-negative female gonadotroph adenoma. The parent cell of this rare variant of a pituitary adenoma is yet unknown.

Diffusion of chlorin-p6 across phosphatidyl choline liposome bilayer probed by second harmonic generation

We have investigated the diffusion of the photosensitizer Chlorin-p(6) (Cp(6)) across a egg lecithin lipid bilayer at different pH by the Second Harmonic Generation (SHG) method. Cp(6) has three ionizable carboxylic acid groups, and consequently, neutral and several ionic forms of Cp(6) are expected to be present in the pH range 3-8. The absorption spectra of Cp(6) get considerably modified in the presence of liposomes as the pH is decreased indicating that the drug liposome binding is pH dependent. The first pK(a) of interconversion (D-C) has been identified at pH ~7.0 by fluorescence measurement in an earlier work. In this work, the second pK(a) of interconversion (C-B) has been identified at pH ~4.8 by the hyper-Rayleigh scattering method. At acidic pH (3, 4, and 5), where species A, B, and C are dominant, the addition of liposomes to a Cp(6) solution generates an instantaneous rise (less than 1 s) in the second harmonic (SH) signal followed by decays whose time constants ranged from ten to hundreds of seconds. The instantaneous rise is attributed to the adsorption of Cp(6) to the outer lipid bilayer, and the decay is attributed to the diffusion of the neutral and charged (A and B) species of the drug. The observed fast and slow time constants for diffusion in the pH range 3-5 are attributed to the neutral (A) and ionic form (B) of Cp(6), respectively. At pH 6, the intensity of the generated SH signals on the addition of liposome reduced, and at physiological pH, it was too weak to be detected. These results are consistent with previous studies that show that the interaction between Cp(6) and egg-PC liposomes is pH dependent. At lower pH due to the presence of the hydrophobic species (A and B) of Cp(6), its interaction with liposomes is strong, and at higher pH, the abundance of the negatively charged hydrophilic species (C and D) decreases the interaction with the like charged liposomes. We have also studied the effect of increasing the bilayer rigidity by decreasing the temperature of the medium or by incorporating 50 mol % cholesterol in the lipid bilayer and observed that lowering of temperature has more profound effect on the diffusion rates. The characteristics of the SH signal changed significantly when liposomes incorporating 50 mol % cholesterol were used at a low (3 °C) temperature. Under these conditions, the SH signal consisted of an instantaneous (<1s) followed by a slower rise (10-90s), and then, it decayed on a much longer time scale. This slow rise of the SH signal at pH 3 and 4 may be attributed to the temperature dependent adsorption of the anionic species (B) of Cp(6) with the liposomes. Further investigations are required in order to understand clearly the pH dependent diffusion of this drug across lipid bilayers.

Particle-yield modification in jetlike azimuthal dihadron correlations in Pb-Pb collisions at √s(NN)=2.76 TeV

The yield of charged particles associated with high-p(t) trigger particles (8<p(t)<15 GeV/c) is measured with the ALICE detector in Pb-Pb collisions at √s(NN)=2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jetlike correlation peaks in azimuthal dihadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta p(t)>3 GeV/c on the away side drops to about 60% of that observed in pp collisions, while on the near side a moderate enhancement of 20%-30% is found.

Clinical utility of pharmacogenetic biomarkers in cardiovascular therapeutics: a challenge for clinical implementation

In the past decade, significant strides have been made in the area of cardiovascular pharmacogenomic research, with the discovery of associations between certain genotypes and drug-response phenotypes. While the motivations for personalized and predictive medicine are promising for patient care and support a model of health system efficiency, the implementation of pharmacogenomics for cardiovascular therapeutics on a population scale faces substantial challenges. The greatest obstacle to clinical implementation of cardiovascular pharmacogenetics may be the lack of both reproducibility and agreement about the validity and utility of the findings. In this review, we present the scientific evidence in the literature for diagnostic variants for the US FDA-labeled cardiovascular therapies, namely CYP2C19 and clopidogrel, CYP2C9/VKORC1 and warfarin, and CYP2D6/ADRB1 and β-blockers. We also discuss the effect of HMGCR/LDLR in decreasing the effectiveness of low-density lipoprotein cholesterol with statin therapy, the SLCO1B1 genotype and simvastatin myotoxicity, and ADRB1/ADD1 for antihypertensive response.

J/ψ polarization in pp collisions at √s=7 TeV

The ALICE Collaboration has studied J/ψ production in pp collisions at √s=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λ(θ) and λ(φ) were obtained. The study was performed in the kinematic region 2.5<y<4, 2<p(t)<8 GeV/c, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Measurements of higher order flow harmonics in Au+Au collisions at √s(NN)=200 GeV

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse

We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.

Gossypiboma presented as abdominal lump seven years after open cholecystectomy

Gossypiboma is very rare in clinical practice. Despite its clinical importance, it carries some medico legal implications. We report a case of gossypiboma in a 54 years old female who presented with pain and a slowly growing lump in the abdomen 7 years after open cholecystectomy. Computed tomography (CT) scan of the abdomen showed a mass with enhanced internal septae and a radio-opaque marker within it, raising the suspicion of a foreign body. She underwent excision of the mass along with a segment of densely adherent transverse colon. Post-operative recovery was uneventful and the patient was well at 19-month follow up.

Gaucher disease

A 14 months old boy of consanguineous parent presented with hepatosplenomegaly with delayed mile stones of development. He is till unable to walk. He was moderately anemic. Moderately wasted and stunted. Neurological examination was normal except subnormal intelligence. This subnormal intelligence and delayed milestone possibly may be due to secondary effect of growth retardation. Musculo-skeletal system examination revealed no abnormality. Diagnosis was supported by typical bone involvement in X-ray film (Thin cortex in Limb bone) and Gaucher cell in the splenic aspiration. There are three sub-types Type I: Non neuropathic form. Type II: Acute neuropathic form. Type III: Chronic neuropathic form. However, some cases do not fit precisely into one of these categories. All forms of Gaucher disease are autosomal recessively inherited. So, this patient more or less correlates with Gaucher disease type I. Treatment option for type I and III include medicine and enzyme replacement therapy, which is usually very effective.

In vitro initiated sperm forward motility in caput spermatozoa: weak and transient

Testicular spermatozoa during journey through epididymis acquire forward motility, which is essential for fertility. To understand the biochemistry of sperm motility initiation, various initiation media have been developed that permitted high level of motility induction (55-60%) in the immature caput-spermatozoa in presence of activating principles: theophylline, bicarbonate and epididymal plasma (EP) when analysed microscopically. Here, we show for the first time using caprine model that stability and quality of in vitro-induced motility in the caput spermatozoa is insignificant in contrast to naturally induced motility in mature cauda spermatozoa. In vitro-induced motility of the immature spermatozoa was lost completely upon the removal of these activators by centrifugation. Selective withdrawal of either EP or HCO(3) by dilution retains 50-60% of the in vitro-induced motility. Spectrophotometric analysis revealed that in vitro-induced vertical motility in immature spermatozoa is too little when compared to mature spermatozoa. In in vitro-initiated caput spermatozoa, cyclic adenosine monophosphate level becomes doubled but lesser than cauda spermatozoa. This revelation concludes that scientific knowledge generated over the years on the basis of in vitro initiation method is insignificant and needs improvisation to delineate biochemical regulation of sperm motility which in turn has remarkable potential in wide biological fields, especially in infertility treatment.

Ultrafast dynamics of excitons in semiconductor quantum dots on a plasmonically active nano-structured silver film

The excited state dynamics of core-shell type semiconductor quantum dots (QDs) of various sizes in close contact with a plasmonically active silver thin film has been demonstrated by using picosecond resolved fluorescence spectroscopy. The non-radiative energy transfer from the QDs to the metal surface is found to be of Förster resonance energy transfer (FRET) type rather than the widely expected nano-surface energy transfer (NSET) type. The slower rate of energy transfer processes compared to that of the electron transfer from the excited QDs to an organic molecule benzoquinone reveals an insignificant possibility of charge migration from the QDs to the metallic film.

Electrical Contacts to Polycrystalline B Doped Diamond Films

B doped diamond films were synthesized by microwave plasma CVD and electrical contacts were fabricated by R F sputtering. Rc was obtained for Pt, Ni, TaSi2, and Al asdeposited contacts at room temperature. Pt gave the minimum Rc and Al gave the maximum Rc of the metals investigated on films containing a carrier concentration of 5 × 1018/cm3. The minimum Rc, 8.6 × 10−4 Ω cm 2, was obtained on heavily B doped diamond films with a carrier concentration of 2.7 × 1020/cm3. After nnealing at 400 °C, the Rc of Pt contacts on B doped diamond films with a resistivity of 2×104 Ω1 cm decreased by approximately one order of magnitude.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

We have measured the azimuthal anisotropy of π⁰ production for 1<p(T)<18  GeV/c for Au+Au collisions at sqrt((s)NN)=200  GeV. The observed anisotropy shows a gradual decrease for 3≲p(T)≲7-10  GeV/c, but remains positive beyond 10  GeV/c. The magnitude of this anisotropy is underpredicted, up to at least ∼10  GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

An effective immunotherapy regimen for VGKC antibody-positive limbic encephalitis

BACKGROUND

Voltage-gated potassium channel antibody-positive limbic encephalitis (VGKC+LE) frequently improves with immunotherapy, although the optimum regimen is unknown. The effectiveness of a combination immunomodulatory regimen was tested in consecutive VGKC+LE patients.

METHODS

This was an open-label prospective study of nine VGKC+LE patients. All patients had plasma exchange (50 ml/kg), intravenous immunoglobulin (2 g/kg) and intravenous methylprednisolone (1 g×3), followed by maintenance oral prednisolone (1 mg/kg/day). Mycophenolate (2 g/day) was used in the first three patients. Assessments included serial clinical, cognitive, brain MRI and VGKC antibody testing.

RESULTS

Within 1 week, seizures and hyponatraemia remitted in all affected patients. Cognitive function improved in all patients within 3 months. MRI appearances improved substantially within 9 months, with remission of inflammation in the majority of patients. All achieved immunological remission with normal VGKC antibody titres within 1-4 months. Major adverse events of therapy included one septicaemia and one thrombosis on plasma exchange and one death from sepsis after incidental bowel surgery. One patient remains in remission after 40 months of follow up, 26 months after being off all treatment.

CONCLUSIONS

Our immunotherapy regimen was effective for the treatment of the clinical, cognitive and immunological features of VGKC+LE. Radiological improvement was seen in the majority. Pending randomised controlled trials, this regimen is proposed for the treatment of VGKC+LE.

Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200 GeV

Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200  GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions.

Transition in yield and azimuthal shape modification in dihadron correlations in relativistic heavy ion collisions

Hard-scattered parton probes produced in collisions of large nuclei indicate large partonic energy loss, possibly with collective produced-medium response to the lost energy. We present measurements of π^{0} trigger particles at transverse momenta p{T}{t}=4-12  GeV/c and associated charged hadrons (p{T}{a}=0.5-7  GeV/c) vs relative azimuthal angle Δϕ in Au+Au and p+p collisions at sqrt[s{NN}]=200  GeV. The Au+Au distribution at low p{T}{a}, whose shape has been interpreted as a medium effect, is modified for p{T}{t}<7  GeV/c. At higher p{T}{t}, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p{T}{a}, which quantitatively challenges some medium response models. The associated yield of hadrons opposing the trigger particle in Au+Au relative to p+p (I{AA}) is suppressed at high p{T} (I{AA}≈0.35-0.5), but less than for inclusive suppression (R{AA}≈0.2).

CT and MRI appearance of solitary parapelvic neurofibroma of the kidney

We report an extremely rare case of a renal parapelvic neurofibroma. The mass was an incidental finding on an abdominal CT scan of an asymptomatic 59-year-old male with hepatitis C. Subsequent MRI demonstrated a complex mass occupying the left renal sinus that had mass effect on the pelvicalyceal system. The patient underwent left radical nephrectomy, and histological and immunohistochemical findings confirmed the lesion to be a neurofibroma. Given that similar imaging features have been reported previously in four additional cases, we suggest that it may be possible to include this entity in the pre-operative differential diagnosis.

Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature

The production of e+ e- pairs for m(e+ e-)<0.3 GeV/c2 and 1<p(T)<5 GeV/c is measured in p+p and Au+Au collisions at square root(S(NN))=200 GeV. An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central Au+Au collisions, the excess of the direct photon yield over p+p is exponential in transverse momentum, with an inverse slope T=221+/-19(stat)+/-19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) approximately 300-600 MeV at times of approximately 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at approximately 170 MeV.

Spatial distribution and r-DNA second internal transcribed spacer characterization of Anopheles dirus (Diptera: Culicidae) complex species in north-east India

The identity and distribution of the prevalent member species of the Anopheles dirus complex mosquitoes in the north-eastern region of India was investigated in a cross-sectional study. We altogether collected 267 individuals of An. dirus s.l. from 27 forested/forest fringed locations spread across the seven north-eastern states, identified the species using a ribosomal DNA (r-DNA) second internal transcribed spacer (ITS2) based allele specific polymerase chain reaction (ASPCR) method and sequenced the ITS2 locus in a sub set of mosquitoes. An. baimaii was identified as the main, almost exclusive (266/267), species of the Dirus complex throughout the north-east India with no intraspecific variation in the 479 base pair long ITS2 sequences in 59 of the 60 individuals sequenced. Ribosomal DNA of one individual from Assam state did not amplify in the ASPCR, possessed 786 base pair long ITS2 sequence and showed 99.7% similarity with the sequence of An. dirus species D (An. baimaii) from Yunnan province of China, later referred to as species X of the Dirus complex. These observations suggest the presence of another, possibly the new, species of the Dirus complex, sympatric with An. baimaii, in Assam warranting investigations on its distribution, biology and role in human malaria transmission in north-east India.

Charged Kaon interferometric probes of space-time evolution in Au+Au collisions at sqrt[S(NN)]=200 GeV

Bose-Einstein correlations of charged kaons are used to probe Au+Au collisions at sqrt[S(NN)]=200 GeV and are compared to charged pion probes, which have a larger hadronic scattering cross section. Three-dimensional Gaussian source radii are extracted, along with a one-dimensional kaon emission source function. The centrality dependences of the three Gaussian radii are well described by a single linear function of N(part)1/3 with a zero intercept. Imaging analysis shows a deviation from a Gaussian tail at r greater than or approximately equal to 10 fm, although the bulk emission at lower radius is well described by a Gaussian. The presence of a non-Gaussian tail in the kaon source reaffirms that the particle emission region in a heavy-ion collision is extended, and that similar measurements with pions are not solely due to the decay of long-lived resonances.

Silicon dioxide embedded germanium nanocrystals grown using molecular beam epitaxy for floating gate memory devices

SiO2/Ge nanocrystals/SiO2 trilayer memory structure has been fabricated by oxidizing and subsequent annealing of self assembled SiGe nanoislands grown by molecular beam epitaxy. The optical and charge storage characteristics of trilayer structures have been studied through Raman spectroscopy and capacitance-voltage measurements, respectively. An anti-clockwise hysteresis in the C-V characteristics indicated the net electron trapping in the floating gate containing Ge nanocrystals. Frequency dependent measurements of device characteristics indicate that neither interface defects nor deep traps are dominant for the charging or discharging processes of nanocrystal floating gates.

Light induced toxicity of merocyanine 540-silica nanoparticle complex

The electrostatic binding between the negatively charged lipophilic dye Merocyanine 540 and silica nanoparticles having 3-amino propyl groups at the surface has been characterized using absorption and fluorescence spectroscopy. The binding of the dye with the nanoparticle resulted in significant changes in its absorption spectra. Further the fluorescence intensity and lifetime gets enhanced by more than an order of magnitude. The results obtained suggest that this is due to the reduced photoisomerization rate of the dye bound to the nanoparticle. Consistent with the expectation that a reduction in the photoisomerization rate should enhance the singlet oxygen yield of the dye via intersystem crossing, the light induced toxicity of the dye-nanoparticle complex (tested with MCF cells) was observed to be higher compared to the free dye.

Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|<0.35 in p+p collisions at square root of s=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range 2<pT<7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D-->e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub.

Gluon-spin contribution to the proton spin from the double-helicity asymmetry in inclusive pi0 production in polarized p+p collisions at [sqrt]s=200 GeV

The double helicity asymmetry in neutral pion production for pT=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DeltaG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of micro2=4 GeV2 a next to leading order QCD analysis gives DeltaG[0.02,0.3]=0.2, with a constraint of -0.7<DeltaG[0.02,0.3]<0.5 at Deltachi2=9 (approximately 3sigma) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the DeltaG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.