Magnetization Reversal in Two-dimensional Ensemble of Nanoparticles with Positional Defects

We study relaxation behaviour in the two-dimensional assembly of magnetic nanoparticles (MNPs) with aligned anisotropy axes and positional defects. The anisotropy axes orientation and disorder strength is changed by varying $\alpha$ and $\Delta$, respectively. The magnetization decay does not depend on the aspect ratio $A^{}_r$ of the system and $\Delta$ for small dipolar interaction strength $h^{}_d=0.2$. Remarkably, the magnetization decays rapidly for considerable $h^{}_d$ with negligible $\Delta$ and $A_r=1.0$. The dipolar interaction of enough strength promotes antiferromagnetic coupling in square ensembles of MNPs. There is a prolonged magnetization decay for large $\Delta$ because of enhancement in ferromagnetic coupling. Notably, magnetization relaxes slowly for $\alpha<\alpha^\star$ even with moderate $h^{}_d$ and a significant $A^{}_r$. Interestingly, the slowing down of the magnetic relaxation shifts to a lower $\alpha^{\star}$ with $h^{}_d=1.0$. The magnetization ceases to relax for $\alpha\leq60^\circ$ and $h^{}_d\leq0.6$ due to large shape anisotropy with $A^{}_r=400.0$. Remarkably, a majority of the magnetic moment reverses its direction by $180^\circ$ for $\alpha>60^\circ$ and large $h^{}_d$, resulting in the negative magnetization. The effective N\'eel relaxation time $\tau^{}_N$ also depends strongly on these parameters. $\tau^{}_N$ depends weakly on $\alpha$ and $\Delta$ for $h^{}_d\leq0.2$, irrespective of $A^{}_r$. On the other hand, $\tau^{}_N$ decreases with $\alpha$ for significant $h^{}_d$ provided $\alpha$ is greater than $45^\circ$ because of antiferromagnetic coupling dominance. In a highly anisotropic system, there is an enhancement in $\tau^{}_N$ with $\alpha$ ($\leq30^\circ$) even with moderate $h^{}_d$. While for $\alpha>30^\circ$, $\tau^{}_N$ decreases with $\alpha$. These observations are useful in novel materials, spintronics based applications, etc.Comment: 22 pages, 8 figure

Thrombocytopenia in pregnancy

Background: Thrombocytopenia in pregnancy is defined as platelet count of less than 150,000/µl. It may be inherited or idiopathic, acute or chronic in onset, either primary or associated with other disorders. Gestational thrombocytopenia is the most common type which is diagnosed usually in the last trimester. When there is severe thrombocytopenia, it is usually pathological in origin. The goal of this study was to identify thrombocytopenia in early stages of pregnancy and evaluate the risk factors involved. Aim was the evaluation of thrombocytopenia in pregnancy.Methods: This was a prospective observational study conducted in the Obstetrics and Gynecology Department of a tertiary care centre from 1st January 2020 to 31st December 2020. Data was collected and analyzed by SPSS version 17.Results: In the current study, 71.1% of cases were mild thrombocytopenia and 64.4% were picked up in the third trimester. Out of the 90 cases taken, 64% of the cases were due to the most common cause i.e., gestational thrombocytopenia. The second most common cause of thrombocytopenia was pregnancy induced hypertension which accounted for 18% of the total number of cases. Symptomatic thrombocytopenia of moderate and severe degree was seen in cases of PIH and ITP. 37.5% of the cases had underlying hypertension.Conclusions: Timely identification and management of the cause of thrombocytopenia is crucial in the antenatal group of women. Although it is an incidental finding in most cases, when there is an underlying cause, severity of thrombocytopenia increases tremendously and has dire consequences. Every pregnant woman should undergo complete blood count examination once in each trimester to avoid maternal and fetal complications

Levels of interluekin-6 and its correlation with maternal outcome in patients of gestational diabetes mellitus

Background: Gestational diabetes mellitus (GDM) is a glucose tolerance disorder that occurs or is diagnosed for the first time during pregnancy. Objective was to see the levels of interluekin-6 and its correlation with maternal outcome in patients of gestational diabetes mellitus.Methods: The source of data for the study is the antenatal patients attending the Outpatient Department or admitted in “Upper India Sugar Exchange Maternity Hospital”, Department of Obstetrics and Gynaecology, G.S.V.M. Medical College, Kanpur. This study was a prospective study done on 120 patients.Results: Most patients in the study group belonged to the age group 20-24 years followed by age group 25-29 years. Level of interleukin-6 was significantly raised in gestational diabetes mellitus patients compared to non-gestational diabetes mellitus. 13.19% patients of GDM had PROM, which was only 6.5% in non GDM patients. 25.79% patients of GDM had preterm, which was only 12.8% in non GDM patients. 5.16% patients of GDM had polyhydramnios, which was only 2.64% in non GDM patients. 17.20% patients of GDM had IUGR, which was only 10.31% in non GDM patients.Conclusions: Gestational diabetes is associated with various maternal complications i.e. preeclampsia, preterm, PROM, IUGR, polyhydramnios, increased operative morbidity, development of type 2 DM

Spontaneous rupture of splenic artery aneurysm in pregnancy: an autopsy-based case report

Splenic artery aneurysm (SAA) is an infrequent form of vascular disease that has a significant potential for rupture, resulting in life-threatening intraperitoneal hemorrhage commonly during pregnancy. The incidence of splenic artery aneurysms has been estimated between 0.01% and 0.98%. We describe a case of sudden death of a 36 years old full term, primigravida female. During autopsy we found ruptured splenic artery aneurysm about 2.0 cm in diameter near hilum with intraperitoneal hemorrhage. It is important to be alert about the possibility of SAA in pregnant women for its early diagnosis, as the chance of it getting ruptured during pregnancy is high with high maternal and fetal mortality rates

Commonly Utilized Non Vascularised Bone Grafts in Maxillofacial Reconstruction

Surgical defects created secondary to oncological resection are often debilitating for patients, both functionally and esthetically. Meticulous surgical planning and intricate knowledge of the vital anatomical structures are essential for understanding the biology of reconstruction in the craniofacial skeleton. Unlike reconstructive procedures in other areas where the functional components may be given priority, reconstruction of the face requires a delicate balance between the esthetic and functional units. Despite new developments, autogenous grafts have frequently remained a reliable alternative that withstood the test of time. Non-vascularized bone grafts are often a subset of autogenous grafts, where the graft solely depends on the recipient’s vascularity and is indicated in defect sizes of less than 6 cm