Perioperative Management of a Patient With Left Ventricular Free Wall Rupture After Myocardial Infarction: A Rare Case Scenario

Myocardial infarction (MI) is typically followed by numerous lethal complications. One such complication is left ventricular free wall rupture (LVFWR). We present the case of a middle-aged hypertensive patient who had a history of unstable angina for seven days. He presented to the emergency room with chest pain, dyspnea, and unstable vital parameters. Clinical signs, electrocardiography, and echocardiography raised the suspicion of left ventricular free wall rupture with ST-segment elevation inferior wall and lateral wall MI. As a result, the patient received aggressive resuscitative measures. Later, he underwent surgical repair for cardiac rupture via cardiopulmonary bypass. Finally, the patient was discharged from the hospital on the 10^th postoperative day. The window period from the onset of cardiac wall rupture to patient admission to the operating room is crucial. This case report highlights that a high index of suspicion for left ventricle free wall rupture should be considered for a patient presenting with MI and cardiogenic shock. Timely diagnosis and quick surgical intervention can deter complications and save the patient.

Annihilation and Control of Chiral Domain Walls with Magnetic Fields

The control of domain walls is central to nearly all magnetic technologies, particularly for information storage and spintronics. Creative attempts to increase storage density need to overcome volatility due to thermal fluctuations of nanoscopic domains and heating limitations. Topological defects, such as solitons, skyrmions, and merons, may be much less susceptible to fluctuations, owing to topological constraints, while also being controllable with low current densities. Here, we present the first evidence for soliton/soliton and soliton/antisoliton domain walls in the hexagonal chiral magnet Mn_1/3NbS₂ that respond asymmetrically to magnetic fields and exhibit pair-annihilation. This is important because it suggests the possibility of controlling the occurrence of soliton pairs and the use of small fields or small currents to control nanoscopic magnetic domains. Specifically, our data suggest that either soliton/soliton or soliton/antisoliton pairs can be stabilized by tuning the balance between intrinsic exchange interactions and long-range magnetostatics in restricted geometries.

Prevalence of myocardial bridge in angiographic population-A study from rural part of western India

Introduction:

Intramural course of coronary artery is known as myocardial bridge (MB). Its prevalence is highly variable. Very few studies have been conducted in India, mostly from southern state and that too covering urban population. There are no studies from western India. In this study we aimed to estimate the prevalence of MB in coronary angiogram from rural part of western India.

Methods and Results:

A total of 4,438 patients underwent coronary angiography for various indications during the study period of 69 months. Mean age of the study population was 53.6 ± 11.2 years. MB was found in 212 (4.77%) of patients, predominantly in males. Unstable angina was the most common presentation among males (28.7%), whereas chronic stable angina was being the most common presentation among females (22.6%). Majority of MBs were seen in left anterior descending artery in its mid part (61%). Mean diameter compression of the affected segment was 32.6% ± 11.8%, with no significant difference seen among males and females or between mid and distal left anterior descending artery.

Conclusion:

Our study showed the prevalence of MB similar to other Indian studies. Left anterior descending artery was most common artery involved. Mean compression was not statistically significant among either sex.

Electronic structure and lattice dynamics of Ba2CuTeO6 single crystals

The electronic structure and lattice dynamics of Ba₂CuTeO₆ single crystals were investigated through spectroscopic ellipsometry and Raman scattering measurements.

Successive spin orderings of tungstate-bridged Li2Ni(WO4)2 of spin 1

Magnetic, thermodynamic, and dielectric properties of Li2Ni(WO4)2 of S  =  1 system have been studied using magnetic susceptibility, specific heat, and dielectric constant measurements. The magnetic orderings can be identified in three stages, including a short range magnetic ordering indicated by the rounded χ(T) peak with maximum at  ∼20 K, and signatures of two successful antiferromagnetic long range orderings near T(N1) ~ 18 K and T(N2) ~ 13 K revealed by the d(χ(T)) /d(T) peaks. The successive long range magnetic orderings are related to the quasi triangular symmetry breaking in the ac- and bc-planes and to the change of the dielectric constant, suggesting the presence of spin-phonon coupling. The specific heat and magnetic entropy analysis for Li2Ni(WO4)2 shows the existence of a significant low dimensional magnetic correlations at high temperature and confirms the long range three-dimensional (3D) behavior of magnetic orderings below T(N1) and T(N2).

Right ventricular thickness as predictor of global myocardial performance in systemic sclerosis: A Doppler tissue imaging study

BACKGROUND

Cardiopulmonary involvement in systemic sclerosis (SSc) is a poor prognostic factor, due to pulmonary hypertension and right ventricular dysfunction. We assessed the echocardiographic parameters of right ventricular (RV) function in SSc and correlated echocardiographic findings to clinical features of the disease.

METHODS

Thirty patients with SSc (cases) and 30 healthy, age-matched subjects (controls) were studied. Echocardiography, including tissue Doppler imaging, was used to evaluate cardiac function.

RESULTS

Pulmonary hypertension could be documented in only 5 cases by Doppler echo, using Bernoulli principle. RV diastolic function was significantly deranged in cases. RV systolic function and left ventricle (LV) diastolic function were also significantly deranged in the cases. RV thickness was increased in patients with SSc. There were no significant differences in the echocardiographic variables between diffuse and limited subtypes of SSc. Myocardial performance index (MPI) of both ventricles were increased in cases. We could demonstrate RV thickness as the single most important predictor of MPI of both ventricles with sensitivity of 82% and specificity of 72% for RV-MPI and 63% for LV-MPI. Diastolic function was not found to be affected by disease duration or Rodnan skin score.

CONCLUSION

Patients with SSc exhibit abnormal RV and LV diastolic functions as well as abnormal RV systolic function. RV wall thickness was found to be simple and the single best predictor of global myocardial performance. RV dysfunction may be a response to intermittent pulmonary arterial hypertension, lung parenchymal involvement, or secondary to LV diastolic dysfunction in SSc.

Development of a ferromagnetic component in the superconducting state of Fe-excess Fe1.12Te(1-x)Sex by electronic charge redistribution

The general picture established so far for the links between superconductivity and magnetic ordering in iron chalcogenide Fe_1+y(Te_1-xSe_x) is that the substitution of Se for Te directly drives the system from the antiferromagnetic end into the superconducting regime. Here, we report on the observation of a ferromagnetic component that developed together with the superconducting transition in Fe-excess Fe_1.12Te_1-xSe_x crystals using neutron and x-ray diffractions, resistivity, magnetic susceptibility and magnetization measurements. The superconducting transition is accompanied by a negative thermal expansion of the crystalline unit cell and an electronic charge redistribution, where a small portion of the electronic charge flows from around the Fe sites toward the Te/Se sites. First-principles calculations show consistent results, revealing that the excess Fe ions play a more significant role in affecting the magnetic property in the superconducting state than in the normal state and the occurrence of an electronic charge redistribution through the superconducting transition.

Crystal growth and magnetic ordering of Na2Ni2TeO6 with honeycomb layers and Na2Cu2TeO6 with Cu spin dimers

We report on the crystal growth and magnetic property studies of layered Na₂Ni₂TeO₆ and Na₂Cu₂TeO₆. The former has a honeycomb layer composed of NiO₆ octahedra and the latter is composed of paired CuO₄ plaquettes connected through TeO₆ octahedra.

Spin polarization and quantum spins in Au nanoparticles

The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(H_a) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(H_a) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization M_P on particle size. The M_P(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter.

Spin, charge and lattice couplings in Cu-deficient oxysulphide BiOCu0.94S

The electrical and magnetic properties of slightly Cu-deficient BiOCu(0.94)S are investigated using neutron diffraction, ac magnetic susceptibility, magnetization and electrical resistivity measurements. The Cu spins order in a ferromagnetic arrangement below T(C) = 250 K. An antiferromagnetic component develops below 180 K when the crystalline unit cell experiences a sharp thermal contraction upon cooling, resulting in a canted ferromagnetic spin arrangement at low temperatures. In the magnetically ordered state the electrical transport can be described using three-dimensional variable range hopping conduction. An applied magnetic field can effectively reduce the hopping barrier. Spin-charge couplings are clearly revealed when the resistivity departs from the hopping conduction and begins to increase with increasing temperatures above 250 K where the Cu spins become disordered.

Synthesis and characterization of FeNi/polymer nanocomposites

Alloyed spherical FeNi-polymer nanocomposites were prepared via wet chemical method using hydrazine as a reducing agent and polymers (PVP and PEG) as reducing and stabilizing agent. Structural studies performed using XRD and TEM shows uniform dispersion of fine FeNi nanocrystallites in nanocomposite particles. The size and thermal stability of FeNi-polymer nanocomposite particles prepared under same reaction condition was found to be dependent on the type and the molecular weight of the polymer used. However, the magnetic properties of nanocomposite particles were not influenced by the polymers. The study highlights subtle differences in using polymers during the synthesis of alloyed nanocomposite particles.

Short range magnetic correlations induced by La substitution in Ho(1-x)La(x)Mn(2)O(5)

Magnetic susceptibility, x-ray diffraction, neutron diffraction and Raman scattering measurements are employed to study the effects of La substitution on the magnetic properties of multiferroic HoMn(2)O(5). 9% and 18% La-substituted compounds crystallize into the same orthorhombic Pbam symmetry as the parent compound. The magnetic responses to an ac driving magnetic field between 40 and 140 K are greatly enhanced by 18% La substitution. The neutron magnetic diffraction patterns reveal the development of short range magnetic correlations below 140 K. In addition, two Raman peaks and a series of new x-ray diffraction peaks suddenly develop below this temperature. Incommensurate long range antiferromagnetic order appears below 38 K. Magnetic frustration could be the main mechanism governing the present observations.