Measurement of the Isolated Nuclear Two-Photon Decay in

The nuclear two-photon or double-gamma (2γ) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the 2γ decay rate in the low-energy regime below the electron-positron pair-creation threshold, we combined the isochronous mode of a storage ring with Schottky resonant cavities. The newly developed technique can be applied to isomers with excitation energies down to ∼100 keV and half-lives as short as ∼10 ms. The half-life for the 2γ decay of the first-excited 0^{+} state in bare ^{72}Ge ions was determined to be 23.9(6) ms, which strongly deviates from expectations.

Study of wave motion on the emergence of veering, locking, and coupling in periodic composite panels.

This research proposes the effect of micropolar-Cosserat (MC) parameters (length-scale parameters and Cosserat shear modulus) on the dispersion characteristics of propagating wave modes in periodic composite panels (PCPs). These inbuilt parameters are due to the assumption of the length-scale boundary conditions that allow for capturing the micro-rotational (MR) wave mode along with the flexural ones. A significant contribution of this study is the transformation of the two-dimensional (2-D) periodic composite problem into a series of one-dimensional (1-D) ones using the MC continuum theory. The analysis employs the transfer matrix method in the framework of the state-space approach to investigate periodic systems in the eigenvalue domain. Additionally, Bloch-Floquet's periodic boundary conditions (PBCs) are applied to the unit cell to ensure the periodicity of the system. The main innovation lies in observing veering, locking, and coupling phenomena, which occur due to alterations in lamina orientation and MC parameters. Moreover, the presence of inbuilt parameters renders the dispersion characteristics highly sensitive to even minor coefficient variations, with a mere 1% change significantly impacting eigenmode fluctuations. The sudden bandgap (BG) disappearing nature could be used to identify the accurate value of the coefficient for designing and analyzing PCPs.

Bands renormalization and superconductivity in the strongly correlated Hubbard model using composite operators method.

We use the composite operator method (COM) to analyze the strongly correlated repulsive Hubbard model, investigating the effect of nearest-neighbor hoppings up to fourth order on a square lattice. We consider two sets of self-consistent equations, one enforcing the Pauli principle and the other imposing charge-charge, spin-spin, and pair-pair correlations using a decoupling scheme developed by Roth (1969Phys. Rev.184451-9). We extract three distinct solutions from these equations: COM1 and COM2 by imposing the Pauli principle and one from Roth decoupling. An overview of the method studying the validity of particle-hole symmetry and the Luttinger theorem for each solution is presented. Additionally, we extend the initial basis to study superconductivity, concluding that it is induced by the Van Hove singularity. Finally, we include higher-order hoppings using realistic estimates for tight binding parameters and compare our results with ARPES measurements on cuprates.

Low temperature Raman spectroscopic study of anharmonic and spin-phonon coupled quasi-two dimensional rare earth based francisites.

Mineral francisites Cu3Bi(SeO3)2O2Cl are unique compounds with interesting quasi two-dimensional structure along with fascinating magnetic properties. The magnetic properties can be fine-tuned when non-magnetic Bi is replaced by a suitable rare earth (RE) metal. It is because of the inclusion of additional magnetic sub-centre RE apart from Cu. Temperature dependent Raman spectroscopy measurements in RE based francisites [Cu3RE(SeO3)2O2Cl, shortly RECufr] were performed in the range of 11 K-295 K. Among the three studied RECufr (LaCufr, NdCufr, and DyCufr) compounds, the properties of phonon vibration vary from moderate (in DyCufr) to weak (in LaCufr) spin phonon coupled and the absence of spin phonon coupling (SPC) (i.e. strictly anharmonic in nature) was observed in NdCufr and the reason for this observation has been provided. More specifically, two Raman-active phonons soften below the antiferromagnetic ordering temperature ofTN≈ 39 K in DyCufr compound, indicating the existence of moderate SPC. This trend of phonon vibration is correlated with magnetic properties, particularly field induced metamagnetic transition (MMT). Strong MMT enabled DyCufr develops SPC, while weak MMT enabled NdCufr is unable to develop SPC.

The virtual multiple sclerosis patient.

Multiple sclerosis (MS) diagnosis typically involves assessing clinical symptoms, MRI findings, and ruling out alternative explanations. While myelin damage broadly affects conduction speeds, traditional tests focus on specific white-matter tracts, which may not reflect overall impairment accurately. In this study, we integrate diffusion tensor immaging (DTI) and magnetoencephalography (MEG) data into individualized virtual brain models to estimate conduction velocities for MS patients and controls. Using Bayesian inference, we demonstrated a causal link between empirical spectral changes and inferred slower conduction velocities in patients. Remarkably, these velocities proved superior predictors of clinical disability compared to structural damage. Our findings underscore a nuanced relationship between conduction delays and large-scale brain dynamics, suggesting that individualized velocity alterations at the whole-brain level contribute causatively to clinical outcomes in MS.

Negative magnetization and magnetic ordering of rare earth and transition metal sublattices in NdFe0.5Cr0.5O3.

We investigate the effect of alloying at the 3dtransition metal site of a rare-earth-transition metal oxide, by considering NdFe0.5Cr0.5O3mixed perovskite with two equal and random distribution of 3d ions, Cr and Fe, interacting with an early 4f rare earth ion, Nd. Employing temperature- and field- dependent magnetization measurements, temperature-dependent x-ray diffraction, neutron powder diffraction, and Raman spectroscopy, we characterize its structural and magnetic properties. Our study reveals bipolar magnetic switching (arising from negative magnetization) and magnetocaloric effect which underline the potential of the studied mixed perovskite in device application. The neutron diffraction study shows the absence of spin reorientation transition over the entire temperature range of 1.5-320 K, although both parent compounds exhibit spin orientation transition. We discuss the microscopic origin of this curious behavior. The neutron diffraction results also reveal the ordering of Nd spins at an unusually high temperature of about 40 K, which is corroborated by Raman measurements.

Two-component nematic superconductivity in 4Hb-TaS2.

Most superconductors have an isotropic, single component order parameter and are well described by the standard (BCS) theory for superconductivity. Unconventional, multiple-component superconductors are exceptionally rare and are much less understood. Here, we combine scanning tunneling microscopy and angle-resolved macroscopic transport for studying the candidate chiral superconductor, 4Hb-TaS2. We reveal quasi-periodic one-dimensional modulations in the tunneling conductance accompanied by two-fold symmetric superconducting critical field. The strong modulation of the in-plane critical field, Hc2, points to a nematic, unconventional order parameter. However, the imaged vortex core is isotropic at low temperatures. We suggest a model that reconciles this apparent discrepancy and takes into account previously observed spontaneous time-reversal symmetry breaking at low temperatures. The model describes a competition between a dominating chiral superconducting order parameter and a nematic one. The latter emerges close to the normal phase. Our results strongly support the existence of two-component superconductivity in 4Hb-TaS2 and can provide valuable insights into other systems with coexistent charge order and superconductivity.

Survivin siRNA increases sensitivity of primary cultures of ovarian cancer cells to paclitaxel

Purpose. This aim of this study was to use ovarian cancer cells shed in ascitic fluid to establish primary cultures and subsequently use it to detect drug resistance to paclitaxel. Survivin siRNA was used to down regulate survivin expression and effect on paclitaxel resistance was also evaluated. Methodology. Ascitic fluid along with corresponding primary tumor tissue was collected from twenty untreated epithelial ovarian cancer patients. Ten primary cultures were established from ascites obtained from untreated ovarian cancer patients in MCDB 105 and M199 medium (ratio 1:1). Knockdown of survivin was done using siRNA and sensitivity to paclitaxel was evaluated by MTT assay. Results. Grape-like clusters of ovarian cancer cells present in ascites attached and gave a characteristic cobble stone appearance. Treatment with survivin siRNA resulted in a fivefold decrease in survivin expression in primary cultures. Survivin siRNA treatment significantly increased the sensitivity of the primary ovarian cancer cell cultures to paclitaxel. Conclusion. Ascitic cancer cells reflect the molecular profile of tumor and can be used to diagnose resistance to chemotherapy. This study also establishes that high survivin expression is also responsible for resistance to paclitaxel (AU)

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Actividad Antimicrobianade Cuminum cyminum L / Antimicrobial Activity of Cuminum cyminum L

El comino (Cuminum cyminum) es un ingrediente habitual en la comida india. Ha sido usado desde hace mucho tiempo en la medicina tradicional para curar la diarrea, dispepsia y trastornos gástricos, así como agente antiséptico. Estudios realizados en nuestro laboratorio han mostrado que el comino tiene una potente actividad antimicrobiana sobre diversas especies de bacterias y hongos, tanto patógenas como no patógenas. Los estudios químicos realizados indican que la mayor parte de esta actividad antimicrobiana es debida al cuminaldehido [p-isopropil benzaldehido] presente en el fruto desecado de esta planta. Los estudios de concentración mínima inhibitoria (CMI) con el cuminaldehido aislado (comparado con el cuminaldehido patrón) indican que es efectivo sobre diferentes microorganismos, incluyendo cepas de bacterias, levaduras y hongos (AU)