Structural and physical properties of Ni1-xVxalloys around and away from quantum critical point

We investigate the room temperature structure (global and local), temperature dependent magnetic and transport behaviour of Ni1-xVx(0⩽x⩽0.13) alloys. Our Energy Dispersive Analysis of x-rays results show that the prepared compositions are stoichiometric. With increase in V doping, the compounds exhibit a quantum phase transition aroundxc= 0.12, where the ferromagnetic phase is suppressed. Our results show that all the compounds stabilize in face centred cubic structure at RT and the lattice parameter shows unusual behaviour close toxc. The magnetic and heat capacity studies show signature of Griffiths phase on either side ofxc. From 25 K to the lowest collected temperature, we observe a linear T dependence of resistivity atx = 0.1 and aroundxc, which is separated by a Fermi-liquid region aroundx = 0.106. This suggests that the origin of the transport behaviour is different around the quantum critical point and away from it. Our Ni K-edge x-ray Absorption Spectroscopy results show that there is a significant reduction in the first coordination number around Ni central atom on doping. Further, with doping, there is distortion in the first coordination shell around Ni. This suggests, with V doping, the local structure around Ni is different from the global structure as obtained from the x-ray Diffraction results. Interestingly, with doping, we observe a direct connection between the extent of distortion at RT and the magnetic disorder obtained at 2 K. We believe our results will motivate the scientific community to further study the interplay between the structural disorder and quantum fluctuations with temperature at the local level.

Anxiolytic potential of resveratrol and rufinamide combination by modulating GABA-ergic transmission: insights from experiments, molecular docking and dynamics simulations

Resveratrol is a polyphenolic phytocompound known to possess anxiolytic-like effects but its impact on central gammaaminobutyric acid (GABA) modulation has never been explored. The purpose of this study was to analyze the anxiolytic-like effects of resveratrol alone and in combination with rufinamide, an antiepileptic drug which has never been studied for its anxiolytic potential. The BALB/c mice were tested in a battery of behavior testing after administration of resveratrol (50 mg/kg) and rufinamide (50 mg/kg) alone and in combination. Moreover, molecular docking studies were also carried out to understand the interaction of resveratrol and rufinamide with GABA aminotransferase, GABA receptor and GABA-A transporter type 1. Resveratrol alone exerted notable anxiolytic-like effects and improved outcomes in few experiments but rufinamide alone did not yield any beneficial outcomes. However, the animal co-administered with resveratrol and rufinamide behaved exceptionally well (p<0.05) and preferred open, illuminated and exposed areas of open field, light/dark and elevated plus maze. Further, these animals showed reduced anxiety towards anxiogenic stimuli i.e. holes and marbles in hole board and marble bury tests, respectively. Resveratrol and rufinamide showed moderate to strong binding affinities with GABA proteins, indicating the potential to treat anxiety-like neurological disorders. Moreover, resveratrol and rufinamide were analyzed using molecular docking to determine their interaction with GABA receptors, transporters, and transaminase. The results suggest that their anxiolytic-like effects may be due to inhibiting GABA reuptake transporter 1 protein, leading to increased synaptic levels of GABA neurotransmitter, as seen in stable molecular dynamics results with the 7SK2 GABA transporter protein.

Pachydermoperiostosis with Hearing Loss

A 21-year-old unmarried man, born of a non-consanguineous marriage, presented to the dermatology department with progressive thickening of the facial skin and eyelids, plus increased folds over his forehead for the last 5 months. He also complained of progressive enlargement of his hands and feet, with intermittent joint pains in his wrists, elbows, and ankles, along with occasional abdominal pain. He had a hearing loss and increased sweating. (SKINmed. 2022;20:311-313).

Structural correlations in the enhancement of ferroelectric property of Sr doped BaTiO3

The effect of Sr doping in BaTiO3(BTO) with nominal compositions Ba0.80Sr0.20TiO3(BSTO) have been explored on its structural, lattice vibration, dielectric, ferroelectric and electrocaloric properties. The temperature dependent dielectric results elucidate the enhancement in dielectric constant and exhibit three frequency independent transitions around 335, 250 and 185 K, which are related to different structural transitions. All these transitions occur at lower temperature as compared with pristine BTO, however; remnant electric polarization (Pr) of BSTO is much higher than in BTO. The value ofPris ∼5μC cm-2at room temperature and the maximumPr∼ 8μC cm-2is observed at tetragonal to orthorhombic and orthorhombic to rhombohedral transitions. The electro-caloric effect shows the maximum adiabatic change in temperature ΔT∼ 0.24 K at cubic to tetragonal transition. The temperature dependent synchrotron x-ray diffraction and Raman results show correlations betweenPr, crystal structure and lattice vibrations. Our results demonstrate the enhancement in ferroelectric properties of BTO with Sr doping. The origin of the enhancement in ferroelectric property is also discussed in correlations with the appearance of superlattice peak around room temperature due to TiO6octahedral distortion. These enhanced properties would be useful to design lead free high quality ferroelectric and piezoelectric materials.

Electronic properties in itinerant ferromagnet SrRu1-x Ti x O3

Here, we study the electrical transport and specific heat in 4d based ferromagnetic material SrRuO₃ and its Ti substituted SrRu_1-x Ti _x O₃ series (x ⩽ 0.7). The SrRuO₃ is a metal and shows itinerant ferromagnetism with transition temperature T _c ∼ 160 K. The nonmagnetic Ti⁴⁺ (3d ⁰) substitution would not only weaken the active Ru-O-Ru channel but is also expected to tune the electronic density and electron correlation effect. A metal to insulator transition has been observed around x ∼ 0.4. The nature of charge transport in paramagnetic-metallic state (x ⩽ 0.4) and in insulating state (x > 0.4) follows modified Mott's variable range hopping model. In ferromagnetic-metallic state, resistivity shows a T ² dependence below T _c which though modifies to T ^3/2 dependence at low temperature. In Ti substituted samples, temperature range for T ^3/2 dependence extends to higher temperature. Interestingly, this T ^3/2 dependence dominates in whole ferromagnetic regime in presence of magnetic field. This evolution of electronic transport behavior can be explained within the framework of Fermi liquid theory and electron-magnon scattering mechanism. The negative magnetoresistance exhibits a hysteresis and a crossover between negative and positive value with magnetic field which is connected with magnetic behavior in series. The decreasing electronic coefficient of specific heat with x supports the increasing insulating behavior in present series. We calculate a high Kadowaki-Woods ratio (x ⩽ 0.3) for SrRuO₃ which increases with substitution concentration. This signifies an increasing electronic correlation effect with substitution concentration.

High pressure study of magnetocaloric effect in Ho3Co and Tb3Co

The magnetocaloric effect of intermetallic compounds of Tb3Co and Ho3Co is studied under high pressures up to ∼1 GPa using pressure dependent dc magnetisation and specific heat measurements at ambient conditions. The magnetic entropy change (-ΔSM) obtained from magnetisation data and adiabatic change in temperature (ΔTad) determined from zero-field specific heat and magnetisation data are found to be nearly identical within error limits with those deduced from purely field dependent specific heat experiments. With increasing hydrostatic pressure to ∼1 GPa, the -ΔSMand ΔTad, both show a significant enhancement of about 37% and 13%, respectively for 9 T field change in case of Tb3Co. On the other hand, Ho3Co exhibits a decrease of about 8% in both -ΔSMand ΔTadwith increasing pressure. The refrigerant capacity (RC) also increases from 650 J kg-1to 847 J kg-1in the case of Tb3Co and it goes down from 665 J kg-1to 615 J kg-1for Ho3Co for an increase of pressure to 1 GPa. With increasing pressure, the peak widths of both -ΔSMand ΔTadincrease in case of Tb3Co, although the increase is more in -ΔSM. However, such noticeable changes in peak widths with pressure were not observed in Ho3Co. At ambient pressure, peak of -ΔSM(-ΔSMpk) scales with(H/TN)2/3for both the compounds, consistent with the prediction of mean field theory (MFT) for second order magnetic transition. However, deviation from MFT was noticed at high pressures as-ΔSMpkwas found to scale with(H/TN)3/4instead of(H/TN)2/3for both the alloys. Further, normalised -ΔSMcurves for different ΔHand pressures collapse on a single universal curve in both the compounds thereby indicating that the second order magnetic transition persists even up to ∼1 GPa pressure.

Effect of Tb substitution in naturally layered LaMn2Si2: magnetic, magnetocaloric, magnetoresistance and neutron diffraction study

Evolution of physical and magnetic properties of La rich La_1-x Tb _x Mn₂Si₂ (x  =  0, 0.1 and 0.225) compounds is studied using temperature and field dependent dc magnetization, electrical transport, and heat capacity measurements. LaMn₂Si₂ undergoes a paramagnetic to antiferromagnetic ordering at T _N ~ 400 K and a long range ferromagnetic ordering below T _C ~ 308 K. However, the substitution of Tb at La site results in the contraction of unit cell as well as decrease in the Mn-Mn spacing, which leads to an additional antiferromagnetic phase below T _N ~ 87 K and 257 K for La_0.9Tb_0.1Mn₂Si₂ and La_0.775Tb_0.225Mn₂Si₂, respectively. Using magnetization isotherm results, we have constructed an H-T phase diagram for x  =  0.225 and have found the coexistence of this additional antiferromagnetic phase with ferromagnetic phase. The phase coexistence at x ~ 0.225 is further analysed using magnetoresistance (MR) and magnetocaloric effect (MCE) studies and a reasonable correlation is established between MCE and MR. In order to analyse the nature of the magnetic transition at T _C, a universal master curve is constructed by rescaling the magnetic entropy curves. Low temperature neutron diffraction measurements performed on the polycrystalline samples revealed a canted ferromagnetic structure for x ~ 0.1 and a canted antiferromagnetic structure for x ~ 0.225.

High pressure study of magnetic properties of Tb3Co

The magnetic properties of rare earth rich intermetallic compound, Tb₃Co, were studied under external pressures up to  ∼1.21 GPa. The application of external pressure results in a decrease of the transition temperatures, [Formula: see text] (paramagnetic to modulated antiferromagnetic) by about 6 K, and the order to order transition that coincides with a glass transition at 72 K by about 15 K, respectively. The low temperature drop in the zero-field cooled magnetisation signifying the strengthening of spin-orbit coupling remains more or less unaffected (shifts only by 3 K) by the external pressures but significant changes in the magnetic behaviour were observed above 40 K. The overall long range non-collinear magnetic order coexisting with glassy behaviour (below 72 K) is sustained even at  ∼1.07 GPa pressure. The rate of decay of [Formula: see text] (d[Formula: see text]) is found to be linear with  -7.2 K GPa^-1 up to  ∼0.9 GPa and then it deviates from linearity. The magnetic relaxations and memory effects studied under different measurement protocols confirm the presence of glassiness right up to the highest pressure, although the glassy behaviour is weakened to some extent with increasing pressure as reflected by faster relaxations.

Magnetic glassy behaviour coupled with long range non-collinear magnetic order in Tb3Co

Detailed and systematic study of rare earth rich intermetallic compound Tb₃Co, using dc magnetisation, neutron powder diffraction, and linear and non-linear ac-susceptibilities, shows the presence of an unexpected magnetic glassy state along with complex non-collinear or modulated antiferromagnetic (AFM) order. Our neutron diffraction study shows that the magnetic structure remains more or less the same except for a decrease in moment values in the temperature range of 2 K-70 K and rules out any phase transition around 30 K. However, it reveals sharp changes in structural parameters around 30 K, which indicates strong spin-lattice coupling and change in strength. It appears to be mainly responsible for the observed increase in ZFC magnetisation on warming around 30 K. Another important unexpected result of this study is the strong frequency dispersion in linear and non-linear (higher order harmonics) ac-susceptibilities below [Formula: see text] K. The analysis in terms of various spin glass theoretical formulisms and even stronger frequency dispersion in non-linear susceptibilities provides evidence for the presence of a spin glass like state in Tb₃Co. The final picture that emerges out of this study is that a spin glass like state coexists with the long range modulated AFM order below 72 K.

Scalable Synthesis of Hide Substance-Chitosan-Hydroxyapatite: Novel Biocomposite from Industrial Wastes and Its Efficiency in Dye Removal

A novel porous polymer-inorganic hybrid biocomposite with various functional groups (hide substance/chitosan/hydroxyapatite) has been synthesized in simple, economic, and scalable process utilizing leather industry solid waste and seafood industry waste composed with hydroxyapatite. Physicochemical characterization of the material reveals formation of composites with homogenous distribution of the constituents in the material matrix. The composite is hard and porous (with 0.1632 cm3/g slit-shaped mesopores and micropores) having particle sizes 40-80 μm and a Brunauer-Emmett-Teller surface area of 55.54 m2/g. The material is polycrystalline in nature with a fair amount of amorphous substance and less hydrophilic in character than constituent polymers. The dye removal efficiency of the material has been tested with two model dyes, namely, methylene blue (MB) (cationic/basic dye) and sunset yellow (SY) (anionic/acid dye). Optimum adsorptions of 3.8 mg MB (pH 12, RT ≈ 27 °C) and 168 mg of SY (pH 3, RT ≈ 27 °C) have been found per gram of the composite material. Langmuir isotherm and pseudo second order rate models have been found to be the best-fit models to explain the equilibrium isotherm and kinetics of the adsorption process for both the dyes. However, higher and faster adsorption of SY in comparison with MB indicated higher binding efficiency of the material toward the acidic dye. Desorption of dyes from the dye-adsorbed material was studied using a suitable eluent of appropriate pH and recycling for five times showed without loss of efficiency. The prepared composite showed very high dye removal efficiency toward four different commercially used dyes (496 mg/g of Orange-NR, 477 mg/g of Red-VLN, 488 mg/g of Blue-113 dye, and 274 mg/g of Green-PbS dye) from their individual and cocktail solutions. It was also efficient to decolorize dye-bearing tannery exhaust bath. Hence, waste materials generated during industrial processes could be efficiently used for the decontamination of colored wastewater produced by various industries.

Mucocutaneous Manifestations in Patients with Chronic Kidney Disease: A Cross-sectional Study

Background:

Chronic kidney disease (CKD)-associated mucocutaneous manifestations significantly impair the quality of life but often remain understudied. They may also vary across regions, socioeconomic and nutritional status, and racial differences.

Objectives:

To study the patterns of mucocutaneous disorders and their prevalence in CKD patients irrespective of clinical stage or dialysis status.

Materials and Methods:

122 (M:F = 77:45) patients aged 21‒85 (Mean ± SD = 57.5 ± 14.0) years having CKD for 3 month to 5 years were studied for mucocutaneous manifestations. Fifty (41%) patients were on hemodialysis for 1‒42 months. Detailed medical history, clinical and mucocutaneous examination, and lab investigations were performed. KOH mounts, skin biopsy, Gram's and Giemsa staining, bacterial or fungal cultures were performed as required.

Results:

Xerosis in 93 (76.2%), skin pallor in 61 (50%), pruritus in 57 (46.7%), pigmentation in 47 (38.5%), and purpura in 18 (14.8%) patients were the major dermatoses. Bullous lesions and perforating folliculitis occurred in 3 (2.5%) patients each. Major nail abnormalities were pallor (in 35.2%), absent lunula (in 23.8%), nail discoloration (in 18%), and “half-and-half nails” in 16.4% patients, respectively. Hair abnormalities included sparse scalp and body hairs (in 35.2% and 13.1%, respectively) and lusterless hair in 12.3% patients. Coated tongue (in 14.8%), xerostomia (in 12.3%), and macroglossia with teeth indention (in 7.4%) patients were the mucosal manifestations.

Conclusions:

Xerosis, pruritus, skin pallor/pigmentary changes, nail pallor, absent lunula, nail discoloration, sparse hairs, coated tongue, xerostomia, macroglossia, and infections were the most common mucocutaneous manifestations in the studied patients irrespective of hemodialysis status. Cold and dry climates might be additional aggravators for xerosis/pruritus. Lifelong follow-up may be needed to reduce the morbidity associated with CKD/hemodialysis specific dermatoses appearing over a period.

Clinicoepidemiologic Features of Chronic Urticaria in Patients with versus without Subclinical Helicobacter pylori Infection: A Cross-Sectional Study of 150 Patients

BACKGROUND

The Helicobacter pylori infection is linked to chronic urticaria in nearly 60% of patients. We studied clinicoepidemiologic features in patients with chronic urticaria with and without H. pylori infection.

METHODS

Endoscopic antral biopsy for the rapid urease test (RUT) and histopathology, and serum IgG ELISA for H. pylori infection were performed in 150 patients (male:female ratio 1:2.4) of chronic urticaria aged 18-68 years. Clinicoepidemiologic features including age, gender, age of onset and duration, frequency and distribution of wheals, urticaria severity score, and systemic symptoms were analyzed in patients with and without H. pylori. The results of serum IgG ELISA for H. pylori were compared with 106 age- and gender-matched healthy adult controls.

RESULTS

The RUT in 84 patients (56%), histopathology in 76 patients (50.6%), and H. pylori IgG ELISA in 94 patients (62.6%) were positive. H. pylori IgG ELISA was positive only in 35 (33%) controls, suggesting that chronic urticaria patients were more likely to have asymptomatic H. pylori infection than normal controls. Although not statistically significant, patients with H. pylori had a higher mean urticaria severity score, number of urticaria/angioedema episodes per year, and involvement of more body sites, particularly the scalp, palms, and soles. The constitutional or gastrointestinal symptoms were statistically higher in patients with H. pylori infection than those without it.

CONCLUSION

A subset of chronic urticaria patients appears to have asymptomatic H. pylori infection. However, its implications in chronicity, recurrences, the severity of urticaria, other systemic manifestations, and management remains conjectural in view of 33% of controls also having positive H. pylori ELISA and the endemicity of infection in developing countries.

Evaluation of Serum Vitamin D Levels in Patients with Systemic Sclerosis and Healthy Controls: Results of a Pilot Study

Background

The anti-inflammatory, immunomodulatory, and anti-proliferative effects of vitamin D in pathogenesis of autoimmune diseases have been highlighted in recent years but implications of vitamin D deficiency in systemic sclerosis (SSc) remain understudied.

Objectives

To evaluate serum vitamin D levels in SSc patients and matched controls.

Materials and Methods

Serum vitamin D levels were estimated in 38 (M:F 5:33) patients aged 23-70 years of untreated SSc and age and gender matched healthy controls. Clinical and investigative evaluation for skin sclerosis by modified Rodnan skin score (mRSS), presence of digital ulcers, Raynaud's phenomenon, type of auto-antibodies, systemic involvement, and serum vitamin D levels were performed. Serum vitamin D levels were defined as normal (30-100 ng/ml), insufficient (10-30 ng/ml), and deficient (<10 ng/ml).

Results

Serum vitamin D levels (median ± IQR) were 19.5 ± 77.8 ng/ml in 38 patients and 100 ± 31.3 ng/ml in controls each. Vitamin D deficiency in 13 (34.2%) and insufficiency in 10 (26.3%) patients were identified. Only 2 (5.3%) controls had vitamin D insufficiency and the difference was statistically significant (P = 0.001). An inverse relationship was observed between mRSS and serum vitamin D levels.

Conclusions

Patients with SSc have significantly lower serum vitamin D levels than healthy controls. Serum vitamin D levels do not correlate well with age, gender, disease duration or its variants, type of auto antibodies, presence of digital ulceration, or systemic involvement but has inverse correlation with skin sclerosis. Better-designed studies will perhaps resolve issues of potential benefits of vitamin D supplementation in modification of disease activity or severity in SSc.

Temperature and impurity effect on parallel field magnetoconductance of bulk insulating topological insulator (Bi1-x Sb x )2Te3

We have performed a systematic parallel field magnetotransport studies of (Bi_1-x Sb _x )₂Te₃ to understand the temperature and impurity effect on the interference of bulk conductance on the surface states of highly insulating topologically insulating compound Bi₂Te₃. The compound exhibits a weak antilocalization effect (WAL) at low temperature and low magnetic field. WAL weakens and a weak localization effect is observed to be developed in the compound with the increase in temperature due to the creation of topologically trivial 2D electron gas states. Strong interlayer interference and coupling of bulk carriers with surface states are observed at low temperature. A similar temperature effect is observed for all concentrations of Sb. Topologically protected surface states enhance with the increase in Sb contents up to x  =  0.3; however, a further increase in Sb concentration leads to a decrease in surface states. The data has been analysed via the generalised Altshuler and Aronov model for parallel field transport anticipating weak antilocalization and interlayer interference.

Case Report: Histoplasmosis in Himachal Pradesh (India): An Emerging Endemic Focus

We describe four cases of histoplasmosis indigenous to Himachal Pradesh (India) that will be of considerable public health interest. A 48-year-old human immunodeficiency virus (HIV)-negative man with cervical and mediastinal lymphadenopathy, hepatosplenomegaly, adrenal mass, and bone marrow involvement was treated as disseminated tuberculosis without benefit. Progressive disseminated histoplasmosis was diagnosed from the fungus in smears from adrenal mass. Another 37-year-old HIV-positive man was on treatment of suspected pulmonary tuberculosis. He developed numerous erythema nodosum leprosum-like mucocutanous lesions accompanied by fever, generalized lymphadenopathy, and weight loss. Pulmonary histoplasmosis with cutaneous dissemination was diagnosed when skin lesions showed the fungus in smears, histopathology, and mycologic culture. Both were successfully treated with amphotericin B/itraconazole. Third patient, a 46-year-old HIV-negative man, had oropharyngeal lesions, cervical lymphadenopathy, intermittent fever, hepatosplenomegaly, and deteriorating general health. Progressive disseminated oropharyngeal histoplasmosis was diagnosed from the fungus in smears and mycologic cultures from oropharyngeal lesions and cervical lymph node aspirates. He died despite initiating treatment with oral itraconazole. Another 32-year-old man 3 months after roadside trauma developed a large ulcer with exuberant granulation tissue over left thigh without evidence of immunosuppression/systemic involvement. He was treated successfully with surgical excision of ulcer under amphotericin B/itraconazole coverage as primary cutaneous histoplasmosis confirmed pathologically and mycologically. A clinical suspicion remains paramount for early diagnosis of histoplasmosis particularly in a nonendemic area. Most importantly, with such diverse clinical presentation and therapeutic outcome selection of an appropriate and customized treatment schedule is a discretion the treating clinicians need to make.

Patch testing and cross sensitivity study of adverse cutaneous drug reactions due to anticonvulsants: A preliminary report

AIM

To evaluate the utility of patch test and cross-sensitivity patterns in patients with adverse cutaneous drug reactions (ACDR) from common anticonvulsants.

METHODS

Twenty-four (M:F = 13:11) patients aged 18-75 years with ACDR from anticonvulsants were patch tested 3-27 mo after complete recovery using carbamazepine, phenytoin, phenobarbitone, lamotrigine, and sodium valproate in 10%, 20% and 30% conc. in pet. after informed consent. Positive reactions persisting on D3 and D4 were considered significant.

RESULTS

Clinical patterns were exanthematous drug rash with or without systemic involvement (DRESS) in 18 (75%), Stevens-Johnsons syndrome/toxic epidermal necrolysis (SJS/TEN) overlap and TEN in 2 (8.3%) patients each, SJS and lichenoid drug eruption in 1 (4.2%) patient each, respectively. The implicated drugs were phenytoin in 14 (58.3%), carbamazepine in 9 (37.5%), phenobarbitone in 2 (8.3%), and lamotrigine in 1 (4.7%) patients, respectively. Twelve (50%) patients elicited positive reactions to implicated drugs; carbamazepine in 6 (50%), phenytoin alone in 4 (33.3%), phenobarbitone alone in 1 (8.3%), and both phenytoin and phenobarbitone in 1 (8.33%) patients, respectively. Cross-reactions occurred in 11 (92%) patients. Six patients with carbamazepine positive patch test reaction showed cross sensitivity with phenobarbitone, sodium valproate and/or lamotrigine. Three (75%) patients among positive phenytoin patch test reactions had cross reactions with phenobarbitone, lamotrigine, and/or valproate.

CONCLUSION

Carbamazepine remains the commonest anticonvulsant causing ACDRs and cross-reactions with other anticonvulsants are possible. Drug patch testing appears useful in DRESS for drug imputability and cross-reactions established clinically.

Knowledge, attitude, and perception of disease among persons living with human immunodeficiency virus/acquired immuno deficiency syndrome: A study from a tertiary care center in North India

Background:

Although modification of behavioral practices among human immunodeficiency virus (HIV)-affected patients is important in decreasing HIV disease transmission, the knowledge, attitude, and perception studies about HIV infection rarely include persons living with HIV/acquired immuno deficiency syndrome (AIDS).

Aims:

To assess knowledge, attitude, and perceptions of persons living with HIV/AIDS for the disease and other epidemiological aspects.

Materials and Methods:

One-hundred and fifty consecutive persons living with HIV/AIDS were enrolled for this questionnaire-based cross-sectional, descriptive study.

Results:

These 150 patients comprised 93 men and 57 women, aged between 14 and 78 (mean 37.13) years. The majority, 112 (74.67%) patients were between 20 and 50 years of age and 116 (77.3%) patients were either illiterate or high-school dropouts. Drivers, laborers, and self-employed comprised 69 (74.2%) patients among affected males. Only 129 (86%) respondents had heard about HIV/AIDS and knew about its heterosexual transmission. Ninety-eight (65.3%) respondents were aware of disease transmission from infected blood or needle pricks. Interestingly, 106 (70.7%) respondents were aware of the importance of using condom in preventing disease transmission. Television/radio was the most common sources of information for 135 (90%) patients. Nearly, 69% respondents disfavored disclosing their disease to friends/colleagues fearing stigmatization.

Conclusions:

Information, education, and communication activities are imperative to educate persons living with HIV/AIDS about life-long nature of the disease, modes of its transmission, and significance of preventive measures to bridge the gaps in their knowledge. While improvement in individual economic status, education, and health services remains highly desirable, mass media can play a pivotal role in creating awareness among masses.

Profile of Rheumatological Manifestations in Leprosy in a Tertiary Care Hospital from Himachal Pradesh

The rheumatological manifestations of leprosy occur singly or in varying combinations, particularly during lepra reactions. Despite being third most common, these remain under diagnosed and under reported. This study has been carried out to study the spectrum of rheumatological manifestations in leprosy patients. One hundred consecutive patients of leprosy presenting during January to December 2013 were studied for rheumatological manifestations. Complete hemogram, serum biochemistry, urinalysis, rheumatoid factor, ASO titer, C-reactive protein, ANA, and x-rays for hands, feet, chest and involved joints were performed. These 100 (M:F 66:34) patients aged between 16-80 years had indeterminate (2 patients), TT (4 patients), BT (26 patients), BB (2 patients), and LL leprosy (32 patients). 27 patients had rheumatological manifestations; arthritis involving large or small joints in 23 patients being the commonest. 7 of 24 patients in type-1 lepra reaction had enthesitis in 3 patients and oligoarthritis in 4 patients. Rheumatoid arthritis-like polyarthritis was noted in 19 patients with type-2 reaction. Tenosynovitis, dactylitis, bony changes were also noted. Except for one case, these features were present in patients having lepra reactions. Rheumatoid factor in 14, ANA in 15, C-reactive protein in 45 cases was positive. ASO was positive 34 cases. Symmetrical polyarthritis involving small joints of hands and feet, oligoarthritis, enthesitis and dactylitis are common in leprosy particularly with borderline leprosy, type-2 lepra reaction especially in the presence of positive RAfactor.

Knowledge, attitude, and perception of disease among persons living with human immunodeficiency virus/acquired immuno deficiency syndrome: A study from a tertiary care center in North India

BACKGROUND

Although modification of behavioral practices among human immunodeficiency virus (HIV)-affected patients is important in decreasing HIV disease transmission, the knowledge, attitude, and perception studies about HIV infection rarely include persons living with HIV/acquired immuno deficiency syndrome (AIDS).

AIMS

To assess knowledge, attitude, and perceptions of persons living with HIV/AIDS for the disease and other epidemiological aspects.

MATERIALS AND METHODS

One-hundred and fifty consecutive persons living with HIV/AIDS were enrolled for this questionnaire-based cross-sectional, descriptive study.

RESULTS

These 150 patients comprised 93 men and 57 women, aged between 14 and 78 (mean 37.13) years. The majority, 112 (74.67%) patients were between 20 and 50 years of age and 116 (77.3%) patients were either illiterate or high-school dropouts. Drivers, laborers, and self-employed comprised 69 (74.2%) patients among affected males. Only 129 (86%) respondents had heard about HIV/AIDS and knew about its heterosexual transmission. Ninety-eight (65.3%) respondents were aware of disease transmission from infected blood or needle pricks. Interestingly, 106 (70.7%) respondents were aware of the importance of using condom in preventing disease transmission. Television/radio was the most common sources of information for 135 (90%) patients. Nearly, 69% respondents disfavored disclosing their disease to friends/colleagues fearing stigmatization.

CONCLUSIONS

Information, education, and communication activities are imperative to educate persons living with HIV/AIDS about life-long nature of the disease, modes of its transmission, and significance of preventive measures to bridge the gaps in their knowledge. While improvement in individual economic status, education, and health services remains highly desirable, mass media can play a pivotal role in creating awareness among masses.

Violaceous Maculopapular Rash in a Newborn: Congenital Rubella Syndrome

Congenital rubella syndrome involves a configuration of systemic and cutaneous manifestations in a neonate due to in utero infection caused by the rubella virus. The case of a preterm neonate with blueberry muffin lesions and classical as well as rare systemic features of congenital rubella syndrome is reported.

Note: Inverted heat pulse method to measure heat capacity during cooling: A counterpart of conventional quasi-adiabatic heat pulse method

A simple method to extract known amount of heat from a sample within a given time interval has been proposed. Using this method, which we call inverted heat pulse (IHP) method, absolute values of heat capacity (C(P)) during cooling can be measured in a manner similar to conventional quasi-adiabatic heat pulse method of measuring C(P) during warming. Absolute accuracy of the measured C(P) using IHP method is found to be better than 2% in the temperature range 100-300 K. Applicability of this method to a broad and hysteretic first order transition is tested by measuring C(P) of Rh doped FePt sample, which shows a antiferromagnetic to ferromagnetic first order transition with a transition width of ∼35 K and hysteresis of ∼6 K. The peak value of the measured C(P) using IHP during cooling as well as entropy change calculated from measured data is found to be in good agreement with that measured during warming using conventional quasi-adiabatic heat pulse method.

Temperature evolution of magnetic and transport behavior in 5d Mott insulator Sr₂IrO₄: significance of magneto-structural coupling

We have investigated the temperature evolution of magnetism and its interrelation with structural parameters in the perovskite-based layered compound Sr2IrO4, which is believed to be a J(eff) = 1/2 Mott insulator. The structural distortion plays an important role in this material and induces a weak ferromagnetism in an otherwise antiferromagnetically ordered magnetic state with a transition temperature around 240 K. Interestingly, at low temperatures, below around 100 K, a change in the magnetic moment has been observed. Temperature dependent x-ray diffraction measurements show that sudden changes in structural parameters around 100 K are responsible for this. Resistivity measurements show insulating behavior throughout the temperature range across the magnetic phase transition. The electronic transport can be described with Mott's two-dimensional variable range hopping (VRH) mechanism, however, three different temperature ranges are found for VRH, which is a result of varying the localization length with temperature. A negative magnetoresistance (MR) has been observed at all temperatures in contrast to positive behavior generally observed in strongly spin-orbit coupled materials. The quadratic field dependence of MR implies the relevance of a quantum interference effect.

Idiopathic hypereosinophilic syndrome: a rare cause of erythroderma

BACKGROUND

Idiopathic hypereosinophilic syndrome (HES) is a rare and potentially lethal disorder characterized by persistently elevated eosinophil counts without any underlying causes. Two variants, the myeloproliferative and lymphocytic hypereosinophilic syndrome, have been identified. The symptoms are variable and related to the organs involved (cardiovascular system, skin, central and peripheral nervous system, gastrointestinal tract, eyes). Skin lesions can be the dominating and/or presenting symptom in about 50% of patients.

MAIN OBSERVATIONS

We describe a 54-year-old man with a 12-year history of skin lesions, clinically consistent with psoriasis and psoriatic erythroderma. The patient was treated with methotrexate with no response. He experienced intense pruritus, dry/coarse skin and palmoplantar hyperkeratosis. Histopathology showed spongiotic dermatitis with no epidermotropism. Inflammatory infiltrates in upper dermis consisted predominantly of lymphocytes and eosinophils. Peripheral and tissue eosinophilia, immunophenotyping, and results of FIP1L1-PDGFRA gene analysis were suggestive of lymphocytic HES. The patient was treated with hydroxycarbamide (1 g/day), prednisolone (40 mg/day) and antihistamines with improvement.

CONCLUSIONS

HES requires early treatment to prevent severe damage of targeted organs. The pleomorphic dermatological manifestations may delay the diagnosis. This case shows the importance of wide differential diagnosis of erythroderma. In this article we discuss the diagnostic criteria, the recommended work-up and management of idiopathic hypereosinophilic syndrome variants.

Low temperature high magnetic field 57Fe Mössbauer study of kinetic arrest in Ta doped HfFe2

Low temperature high magnetic field (57)Fe Mössbauer measurements were carried out on the inter-metallic compound Hf0.77Ta0.23Fe2 by following novel paths in H-T space. The ferromagnetic (FM) fraction at 5 K and zero magnetic field is shown to depend on the cooling field, i.e., the higher the field is, the higher the FM fraction is. Mössbauer spectra collected in the presence of a 4 T magnetic field show that the antiferromagnetic (AFM) spins are canted with respect to the applied magnetic field and hence contribute to the total bulk magnetization in this compound. The data also show an induced magnetic moment even at the 2a site of the AFM phase. Mössbauer spectra collected using the CHUF (cooling and heating in un-equal magnetic fields) protocol show a reentrant transition when the sample is cooled in zero field and measured during warming in 4 T, showing the FM state as the equilibrium state. This work is the first microscopic experimental evidence for the de-vitrification of the kinetically arrested magnetic state.

Enhancement of the ferromagnetic metallic phase fraction by extrinsic disorder in phase separated La(5/8-y)Pr(y)Ca(3/8)MnO3 (y = 0.45) thin film

Our study shows that extrinsic disorder plays a decisive role in shaping inhomogeneities at large length scales in phase separated systems. Epitaxial La5/8-yPryCa3/8MnO3 (y = 0.45) thin films grown on SrTiO3, LaAlO3 and NdGaO3 substrates exhibited comparable biaxial strain while showing markedly dissimilar extrinsic disorder. Compressively strained film on LaAlO3 is found to be free from extrinsic disorder and has a robust insulating phase with small phase separation while film grown on SrTiO3 shows huge extrinsic disorder due to the strain relaxation process which invokes phase separation at a large length scale that is sufficient to cross the percolation threshold and cause a metal-insulator transition.

Concentration dependence in kinetic arrest of the first-order magnetic transition in Ta doped HfFe2

Magnetic behavior of the pseudo-binary alloy Hf(1-x)Ta(x)Fe(2) has been studied, for which the zero-field ferromagnetic (FM) to antiferromagnetic (AFM) transition temperature is tuned near to T = 0 K. Our studies show that such composition lies around x = 0.230. Detailed magnetization studies on x = 0.225, 0.230 and 0.235 show thermomagnetic irreversibility at low temperature due to kinetic arrest of the first-order AFM-FM transition. All three compositions studied show a reentrant transition in the zero-field-cooled warming curve and non-monotonic variation of the upper critical field. The region in H-T space where these features of kinetic arrest manifest themselves increases with increasing Ta concentration.

Spin-valve-like magnetoresistance in Mn2NiGa at room temperature

Spin valves have revolutionized the field of magnetic recording and memory devices. Spin valves are generally realized in thin film heterostructures, where two ferromagnetic (FM) layers are separated by a nonmagnetic conducting layer. Here, we demonstrate spin-valve-like magnetoresistance at room temperature in a bulk ferrimagnetic material that exhibits a magnetic shape memory effect. The origin of this unexpected behavior in Mn(2)NiGa has been investigated by neutron diffraction, magnetization, and ab initio theoretical calculations. The refinement of the neutron diffraction pattern shows the presence of antisite disorder where about 13% of the Ga sites are occupied by Mn atoms. On the basis of the magnetic structure obtained from neutron diffraction and theoretical calculations, we establish that these antisite defects cause the formation of FM nanoclusters with parallel alignment of Mn spin moments in a Mn(2)NiGa bulk lattice that has antiparallel Mn spin moments. The direction of the Mn moments in the soft FM cluster reverses with the external magnetic field. This causes a rotation or tilt in the antiparallel Mn moments at the cluster-lattice interface resulting in the observed asymmetry in magnetoresistance.

Influence of local structure on magnetic properties of layered cobaltites PrBaCo2O(5+δ), δ > 0.5

The effect of local structure on the magnetic and transport properties of the layered perovskites has been investigated. The samples PrBaCo(2)O(5+δ), (δ = 0.80 and 0.67) crystallize in the same 112 type tetragonal structure but have different magnetic ground states. Extended x-ray absorption fine structure (EXAFS) spectroscopy has been employed to explain the changes in magnetic interactions based on the rotation and tilting of CoO polyhedra in these oxygen-rich double perovskites.

The metal-insulator transition in nanocrystalline Pr0.67Ca0.33MnO3: the correlation between supercooling and kinetic arrest

The transition and hysteresis widths of a disorder broadened first order magnetic transition vary in H-T space which influences the co-existing phase fraction at low temperature arising due to kinetic arrest of the first order transition. We explored the role of change in the relative width of the supercooling/superheating band and kinetic arrest band for a ferromagnetic metallic to antiferromagnetic insulating transition. It is shown that for a correlated kinetic arrest and supercooling bands, the topology of the devitrification curves (or transformation across the (H(K),T(K)) band during warming) changes with the change in the relative width of these two bands. In addition to this, for a broader kinetic arrest band, the transformation temperature across the superheating band under constant H now depends on the arrested phase fraction. These predictions have been tested on nanocrystalline Pr(0.67)Ca(0.33)MnO(3), which is known to show a large variation in hysteresis width in H-T space. This is the first report where correlation between the kinetic arrest band and the supercooling band has been shown experimentally, in contrast to the universal observation of anticorrelation reported so far.

First-order antiferro-ferromagnetic transition in Fe(49)(Rh(0.93)Pd(0.07))(51) under simultaneous application of magnetic field and external pressure

A magnetic field-pressure-temperature (H-P-T) phase diagram for first-order antiferromagnetic (AFM) to ferromagnetic (FM) transitions in Fe(49)(Rh(0.93)Pd(0.07))(51) has been constructed using resistivity measurements under simultaneous application of magnetic field (up to 8 T) and pressure (up to 20 kbar). The temperature dependence of resistivity (ρ-T) shows that the width of the transition and the extent of hysteresis decreases with pressure and increases with magnetic field. By exploiting opposing trends of dT(N)/dP and dT(N)/dH (where T(N) is the first-order transition temperature), the relative effects of temperature, magnetic field and pressure on disorder-broadened first-order transitions has been studied. For this, a set of H and P values are chosen for which T(N)(H(1),P(1)) = T(N)(H(2),P(2)). Measurements for such combinations of H and P show that the temperature dependence of resistivity is similar, i.e. the broadening (in temperature) of transition as well as the extent of hysteresis remains independent of H and P. Isothermal magnetoresistance measurements under various constant pressures show that even though the critical field required for AFM-FM transition depends on applied pressure, the extent of hysteresis as well as transition width (in magnetic field) remains constant with varying pressure.

A change from second- to first-order transition in (La(1-x)Eu(x))0.67Ca0.33MnO3 (0 ≤ x ≤ 0.2)

A detailed investigation of the paramagnetic to ferromagnetic transition in (La(1-x)Eu(x))(0.67)Ca(0.33)MnO(3) having small Eu(3+)-content (0 ≤ x ≤ 0.2) has been carried out through resistivity and magnetization measurements. X-ray diffraction patterns of the compounds reveal a single phase (La(1-x)Eu(x))(0.67)Ca(0.33)MnO(3) (0 ≤ x ≤ 0.2) of an orthorhombic crystal structure after annealing the precursor at 800 °C for 2 h in air. With increasing Eu(3+)-content, the second-order transition (at x = 0 and 0.1) changes to first-order at x = 0.2. The experimental results demonstrate thermomagnetic irreversibility of the transition for x = 0.2 composition. This arises between the supercooling and superheating regimes where both the ferromagnetic and paramagnetic phases coexist.

Effect of strain on the phase separation and devitrification of the magnetic glass state in thin films of La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.45)

We present our study of the effect of substrate induced strain on La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.45) thin films grown on LaAlO(3), NdGaO(3) and SrTiO(3) substrates that show large scale phase separation. It is observed that unstrained films grown on NdGaO(3) behave quite similarly to bulk material but the strained films grown on SrTiO(3) show melting of the insulating phase to the metallic phase at low temperatures. However, the large scale phase separation and metastable glass-like state is observed in all the films despite differences in substrate induced strain. The measurements of resistivity as a function of temperature under a cooling and heating in unequal field (CHUF) protocol elucidate the presence of a glass-like metastable phase generated due to kinetic arrest of the first order transformation in all the films. Like structural glasses, these magnetic glass-like phases show evidence of devitrification of the arrested charge order antiferromagnetic insulator (CO-AFI) phase to the equilibrium ferromagnetic metallic (FMM) phase with isothermal increase of magnetic field and/or iso-field warming. These measurements also clearly show the equilibrium ground state of this system to be FMM and the metastable glass-like phase to be AFI phase.

Field dependence of temperature induced irreversible transformations of magnetic phases in Pr(0.5)Ca(0.5)Mn(0.975)Al(0.025)O(3) crystalline oxide

Glass-like arrest has recently been reported in various magnetic materials. As in structural glasses, the kinetics of a first order transformation is arrested while retaining the higher entropy phase as a non-ergodic state. We show visual mesoscopic evidence of the irreversible transformation of the arrested antiferromagnetic-insulating phase in Pr(0.5)Ca(0.5)Mn(0.975)Al(0.025)O(3) to its equilibrium ferromagnetic-metallic phase with an isothermal increase of magnetic field, similar to its iso-field transformation on warming. The magnetic field dependence of the non-equilibrium to equilibrium transformation temperature is shown to be governed by Le Chatelier's principle.

Magnetoresistance studies on RPd(2)Si (R = Tb, Dy, Lu) compounds

Magnetoresistance studies on RPd(2)Si (R = Tb, Dy and Lu) compounds show large negative magnetoresistance (MR) in TbPd(2)Si and DyPd(2)Si near the magnetic ordering temperature. Positive MR at low temperature in the ferromagnetic Dy compound is shown to arise from the orbital contribution (the Lorentz force effect). As a consequence, a deviation from the linear relation between MR and isothermal entropy change (i.e. the magnetocaloric effect) is observed. In the case of the Tb compound, anomalous magnetoresistance behavior is observed at 3 K, where the resistivity is found to be different before and after magnetic field cycling. These results suggest complex magnetic behavior in TbPd(2)Si.

Photo-induced insulator-metal transition probed by Raman spectroscopy

Strongly correlated electron systems give an opportunity to manipulate charge, orbital, magnetic and structural phases of matter. Here we show that the insulating phase where charges are localized can be delocalized through photo-excitation which, in turn changes the structure locally, inducing an orthorhombic to rhombohedral phase transition. The I-M transition was witnessed for La(1-x)Sr(x)MnO(3) compounds in Raman spectra and photo-induced conduction simultaneously. A simple continuous argon ion laser source was used for optical excitation. The photon energy was 2.53 eV and the power can be chosen anywhere between 5 and 45 mW. Our studies clearly bring out the role of local disorder in the form of Jahn-Teller distortion in the localization of electrons.