Heat capacity and magnetoresistance in Dy(Co,Si)2 compounds

Magnetocaloric effect and magnetoresistance have been studied in Dy(Co1-xSix)2 [x=0, 0.075 and 0.15] compounds. Magnetocaloric effect has been calculated in terms of adiabatic temperatue change (Delta Tad) as well as isothermal magnetic entropy change (Delta SM) using the heat capacity data. The maximum values of DeltaSM and DeltaTad for DyCo2 are found to be 11.4 JKg-1K-1 and 5.4 K, respectively. Both DSM and DTad decrease with Si concentration, reaching a value of 5.4 JKg-1K-1 and 3 K, respectively for x=0.15. The maximum magnetoresistance is found to about 32% in DyCo2, which decreases with increase in Si. These variations are explained on the basis of itinerant electron metamagnetism occurring in these compounds.Comment: Total 8 pages of text and figure

Multiple magnetic transitions and magnetocaloric effect in Gd1-xSmxMn2Ge2 compounds

Magnetic and magnetocaloric properties of polycrystalline samples of Gd1-xSmxMn2Ge2 have been studied. All the compounds except GdMn2Ge2 show re-entrant ferromagnetic behavior. Multiple magnetic transitions observed in these compounds are explained on the basis of the temperature dependences of the exchange strengths of the rare earth and Mn sublattices. Magnetocaloric effect is found to be positive at the re-entrant ferromagnetic transition, whereas it is negative at the antiferro-ferromagnetic transition. In SmMn2Ge2, the magnetic entropy change associated with the re-entrant transition is found to decrease with field, which is attributed to the admixture effect of the crystal field levels. The isothermal magnetic entropy change is found to decrease with increase in Sm concentration.Comment:

Heat capacity and magnetocaloric effect in polycrystalline Gd1-xSmxMn2Si2

We report the magnetocaloric effect in terms of isothermal magnetic entropy change as well as adiabatic temperature change, calculated using the heat capacity data. Using the zero field heat capacity data, the magnetic contribution to the heat capacity has been estimated. The variations in the magnetocaloric behavior have been explained on the basis of the magnetic structure of these compounds. The refrigerant capacities have also been calculated for these compounds

Morphometric study of acromion process in scapula of north Indian population

Background: In scapula, the acromion process projects forwards almost at right angle from the lateral end of spine. Morphometry of the acromion process is an important factor in contributing to impingement syndrome of the shoulder joint.Methods: The study was performed at Department of Anatomy, PGIMS Rohtak on 50 pairs of human scapula, out of which 30 were males and 20 were females. The various parameters like length, width, thickness, coraco-acromial distance, acromio-glenoid distance and types of acromion process were recorded using vernier calipers. These parameters were compared in both sexes on both the sides.Results: Type-II Acromion i.e. Curved type was found to be most predominant. Statistically significant difference was noted in all the five parameters between males and females except Acromio-glenoid distance on right side.Conclusions: Knowledge of the morphometric parameters of acromion process is important for Orthopaedicians, Anthropologists and Anatomists

A study on morphometry of coracoid process of scapula in north Indian population

Background: Coracoid process is a part of scapula and plays an important role in shoulder function. It arises from the antero-lateral aspect of the scapula. The aim of our study is to record the various morphometric parameters of the coracoid process.Methods: The study was performed on 50 pairs of human scapula of known sex in Department of Anatomy at PGIMS Rohtak. The parameters recorded were length, breadth, thickness, height and types of coraco-glenoid space by using vernier calipers. These parameters were compared in both sexes on both the sides.Results: Type I (round bracket) coraco-glenoid space was found to be predominant. Statistically significant difference was noted in all four parameters between males and females except in thickness on right side. Though all the four parameters have higher values on right side in comparison to left side but the difference was statistically insignificant.Conclusions: The study provides valuable information regarding the role of these parameters in etiology of subcoracoid impingement syndrome which will be helpful in its management to the surgeons

Magnetic, magnetocaloric and magnetotransport properties of RSn_{1+x}Ge_{1-x} compounds (R=Gd, Tb, Er; x=0.1)

We have studied the magnetic, magnetocaloric and magnetotransport properties of RSn1+xGe1-x(R=Gd, Tb, Er; x=0.1) series by means of magnetization, heat capacity and resistivity measurements. It has been found that all the compounds crystallize in the orthorhombic crystal structure described by the centrosymmetric space group Cmcm (No. 63). The magnetic susceptibility and heat capacity data suggest that all the compounds are antiferromagnetic. Large negative values of {\theta}p in case of GdSn1.1Ge0.9 and TbSn1.1Ge0.9 indicate that strong antiferromagnetic interactions are involved, which is also reflected in the magnetization isotherms. On the other hand ErSn1.1Ge0.9 shows weak antiferromagnetic interaction. The heat capacity data have been analyzed by fitting the temperature dependence and the values of {\theta}D and {\gamma} have been estimated. Among these three compounds, ErSn1.1Ge0.9 shows considerable magnetic entropy change of 9.5 J/kg K and an adiabatic temperature change of 3.2 K for a field of 50 kOe. The resistivity data in different temperature regimes have been analyzed and the dominant contributions have been identified. All the compounds show small but positive magnetoresistance.Comment: 23 pages,11 figure

Follicular Adenomatoid Odontogenic Tumor in Mandible: A Rare Case Report

Adenomatoid odontogenic tumor (AOT) is a relatively rare, benign, hamartomatous, and cystic odontogenic neoplasm that was first described more than a century ago. The lesion still continues to intrigue experts with its varied histomorphology and controversies regarding its development. The present article describes a case of cystic AOT with an unusual histomorphology associated with an impacted 44 in a 21‑year‑old male.Keywords: Adenomatoid odontogenic tumors, Cystic neoplasms, Odontogenic hamartomas, Odontogenic tumor

Intractable Hiccups and a Posterior Fossa Arteriovenous Malformation: A Case Report

A 29-year-old man is presented who developed intractable hiccups following a subarachnoid hemorrhage from a posterior fossa dural arteriovenous malformation (AVM). The hiccups persisted even after various treatments had been attempted, and the AVM had been excised surgically. The hiccups stopped after a bilateral phrenic nerve section was performed. This report reviews the central causes and mechanisms of hiccups and emphasizes the importance of selective vertebral angiography in demonstrating posterior fossa AVM

CISPLATIN NEPHROTOXICITY AND HYDRATION PROTOCOLS

Objective : Ahmed Usman, Heeranand Keswani, Suresh Nagdev, Ghulam Haider, Tehseen Khursheed, Anis Malik, Kasif Jafferi To evaluate the nephrotoxicity of cisplatiri in cancer patients, using different protocols of hydration. Study Design : Randomized controlled trial. Patients & Methods : This study was conducted between 1st June to 30th November 2004. Ninetynine patients with normal renal function were enrolled in the study and randomly assigned into the 3 study groups, each group having 33patients. In group 1 hydration was done with saline (2 liter) alone, in group 2 with saline (2 liter) and furosemide (40mg) and in group 3 with saline (2 liter) and mannitol (100ml). All 3group patients were given cisplatin infusion 100 mg/m2 over 1 hour and the cycles repeated every 21-28 days. Twenty four hour creatinine clearance was measured before and after 6th day of the chemotherapy in all patients. Results: For the first cycle of chemotherapy the 24-hour urinary creatinine clearance before chemotherapy for saline group was 95.54+/- 15.27, for saline and furosemide group 98.43+/ - 13.44 and for saline and mannitol group 97.45+/ - 14.05 ml/ min and after 6th day of cisplatin infusion was 77.4+/-14.59 for saline group, 86.06+/-11.9 for saline and furosemide group and 82.29+/- 13.64 for saline and mannitol group. The reduction in creatinine clearance was less with saline and furosemide group (12.6%) as compared to saline and mannitol group (15.6%) and saline alone (18.9%) which is statistically significant. Each patient in these 3 study groups received many courses of cisplaiiri and showed the similar pattern. Conclusions : Hydration with saline and furosemide isless nephrotoxic than other protocols with cisplatin infusion

Effect of Ge substitution for Si on the anomalous magnetocaloric and magnetoresistance properties of GdMn2Si2 compounds

The effect of Ge substitution on the magnetization, heat capacity, magnetocaloric effect and magnetoresistance of GdMn2Si2-xGex (x=0, 1, and 2) compounds has been studied. The magnetic transition associated with the Gd ordering is found to change from second order to first order on Ge substitution. Magnetic contributions to the total heat capacity and the entropy have been estimated. Magnetocaloric effect has been calculated in terms of adiabatic temperature change (deltaTad) as well as isothermal magnetic entropy change (deltaSM) using the heat capacity data. The temperature dependence of the magnetocaloric effect in all the three compounds have shown broad peaks. The maximum values of deltaSM and deltaTad for GdMn2Ge2 are found to be 5.9 J/kgK and 1.2 K, respectively. The magnetoresistance is found to be very large and positive with a maximum value of about 22% in the case of GdMn2Ge2. In the other two compounds also, the magnetoresistance is predominantly positive, except in the vicinity of the Gd ordering temperature. The anomalous nature of the magnetocaloric effect and the magnetoresistance has been attributed to the canted magnetic structure of these compounds