Measurement of radioactivity in soils of Karamjal and Harbaria mangrove forest of Sundarbans for establishment of radiological database

This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.

Inequality of handwashing practice using antimicrobial agents in Bangladesh: a household level analyses

OBJECTIVES

About 2.3 billion individuals worldwide are still deprived of the amenity of handwashing with antimicrobial agents. The progress of handwashing with antimicrobial agents in Bangladesh is relatively slower than in many developing countries. The objective of this study was to capture the inequality of the prevalence of handwashing with antimicrobial agents and to identify the factors that are potentially contributing to socio-economic inequalities of handwashing practice in Bangladesh.

STUDY DESIGN

Cross-sectional study.

METHODS

The present study used the nationally representative cross-sectional data from the latest Bangladesh Demographic and Health Survey (BDHS) 2017-18. A total of 19,457 households were included in the analysis of this study. A regression-based decomposition method was applied to assess the socio-economic contributors of inequality.

RESULTS

This study showed that only 38% of Bangladeshi households wash their hands with antimicrobial agents while a pro-rich socio-economic inequality was observed. Household's wealth index was responsible for about 46% of the overall inequality of handwashing with antimicrobial agents while the type of place for handwashing variable contributed 38% of total inequalities. Hygienic toilet facilities (12%) and exposure to mass media (7.4%) are other determinants of total inequalities of handwashing with antimicrobial agents.

CONCLUSIONS

Despite recent declines in attributable mortality, handwashing with antimicrobial agents remains an important determinant of public health problems in many developing countries like Bangladesh. The regular programs aimed at promoting best hand hygiene practices and ensuring the availability of the necessary infrastructure at the community level will be important measures to eliminate this inequality at the population level.

Validation of mobile Decision Support System for scheduling age-appropriate immunizations

Background

The prevalence of missed opportunities for immunization among children is estimated to be 32.2%. The introduction of new vaccines in EPI schedule and lack of training of frontline health workers (FHWs) on the guidelines for number and spacing of doses and manual construction of vaccine schedules based on a child's age deteriorates efficiencies of FHWs, especially in forecasting catch-up schedules. We have designed and tested the validity of an innovative Decision Support System Application Programming Interface (DSS-API) which will automatically generate an age-appropriate immunization schedule for a child.

Methods

Using a multi-country setting approach, DSS was deployed in six immunization facilities of Pakistan and Bangladesh between July 2019 to April 2020. Details of all visiting children were recorded in database. Information on date of birth and past immunization history was used by the DSS-API to determine an individualized age-appropriate immunization schedule. These schedules were compared to the gold standard's outputs calculated by an immunization expert.

Results

A total of 6,241 vaccination events were recorded from all the sites. Using area under the curve, the calculated sensitivity of DSS to determine age-appropriate immunization schedule was found between 99-100% for the individual EPI vaccines, while the specificity of the DSS algorithm was found between 98-100%.

Conclusions

DSS is a feasible feature that can be incorporated in Digital Immunization Registries to accurately schedule routine and catch-up immunizations and can effectively reduce Missed Opportunities for Immunizations by assisting FHWs through automatic construction of immunization schedules.

Key messages

DSS-API is a unique application that can improve process efficiencies of frontline health workers by automatic generation of accurate age-appropriate catch-up vaccine schedules. DSS has the potential to reduce missed opportunities for immunization (MOI) and improve immunization coverage and timeliness among children aged under 2 years.

Ferromagnetic resonance studies of strain tuned Bi:YIG films

Bismuth-doped Yttrium iron garnet (Bi:YIG) thin films known for large magneto-optical activity with low losses still need to get probed for its magnetization dynamics. We demonstrate a controlled tuning of magnetocrystalline anisotropy in Bi-doped Y₃Fe₅O₁₂ (Bi:YIG) films of high crystalline quality using growth induced epitaxial strain on [1 1 1]-oriented Gd₃Ga₅O₁₂ (GGG) substrate. We optimize a growth protocol to get thick highly-strained epitaxial films showing large magneto-crystalline anisotropy, compare to thin films prepared using a different protocol. Ferromagnetic resonance measurements establish a linear dependence of the out-of-plane uniaxial anisotropy on the strain induced rhombohedral distortion of Bi:YIG lattice. Interestingly, the enhancement in the magnetoelastic constant due to an optimum substitution of Bi³⁺ ions with strong spin orbit coupling does not strongly affect the precessional damping (∼[Formula: see text]). Large magneto-optical activity, reasonably low damping, large magnetocrystalline anisotropy and large magnetoelastic coupling in Bi:YIG are the properties that may help Bi:YIG emerge as a possible material for photo-magnonics and other spintronics applications.

Thermal transport studies on charge density wave materials LaPt2Si2 and PrPt2Si2

We measured the thermal properties of polycrystalline samples of LaPt₂Si₂ and PrPt₂Si₂ using thermopower (S) along with thermal conductivity (κ) in the temperature range 10 K-300 K. Significant anomalies related to charge density waves (CDW) around 112 K and 88 K respectively have been observed in [Formula: see text] in both systems. Analysis of thermopower by a two band model suggests that the observations are consistent with a reduction of electron charge density. A change in slope accompanied by a drop in the value of thermal conductivity has been observed around T _CDW in case of LaPt₂Si₂. Analysis of thermal conductivity of this material suggests that the CDW mainly affects electronic contribution to thermal transport. Only a slight change of slope has been detected in temperature dependent thermal conductivity in the case of PrPt₂Si₂ around T _CDW, while its resistivity shows a clear anomaly which shows that electronic part of thermal conductivity is mainly influenced by the CDW in this case also. It is interesting to note that the lattice contribution to thermal conductivity remains unaffected by the CDWs in both materials.

Kondo effect with tunable spin-orbit interaction in LaTiO3/CeTiO3/SrTiO3 heterostructure

We have fabricated epitaxial films of CeTiO₃ (CTO) on (0 0 1) oriented SrTiO₃ (STO) substrates, which exhibit highly insulating and diamagnetic properties. X-ray photoelectron spectroscopy was used to establish the 3+  valence state of the Ce and Ti ions. Furthermore, we have also fabricated δ (CTO) doped LaTiO₃ (LTO)/SrTiO₃ thin films which exhibit variety of interesting properties including Kondo effect and spin-orbit interaction (SOI) at low temperatures. The SOI shows a non-monotonic behaviour as the thickness of the CTO layer is increased and is reflected in the value of characteristic SOI field ([Formula: see text]) obtained from weak anti-localization fitting. The maximum value of [Formula: see text] is 1.00 T for δ layer thickness of 6 u.c. This non-monotonic behaviour of SOI is attributed to the strong screening of the confining potential at the interface. The screening effect is enhanced by the CTO layer thickness and the dielectric constant of STO which increases at low temperatures. Due to the strong screening, electrons confined at the interface are spread deeper into the STO bulk where it starts to populate the Ti [Formula: see text] subbands; consequently the Fermi level crosses over from [Formula: see text] to the [Formula: see text] subbands. At the crossover region of [Formula: see text] where there is orbital mixing, SOI goes through a maximum.

Superconducting and charge density wave transition in single crystalline LaPt2Si2

We present results of our comprehensive studies on single crystalline LaPt₂Si₂. Pronounced anomaly in electrical resistivity and heat capacity confirms the bulk nature of superconductivity (SC) and charge density wave (CDW) transition in the single crystals. While the charge density wave transition temperature is lower, the superconducting transition temperature is higher in single crystal compared to the polycrystalline sample. This result confirms the competing nature of CDW and SC. Another important finding is the anomalous temperature dependence of upper critical field H _C2(T). We also report the anisotropy in the transport and magnetic measurements of the single crystal.

Coexistence of superconductivity and a charge density wave in LaPt2(Si1-x Ge x )2 (0 ⩽ x ⩽ 0.5)

Interplay between a charge density wave (CDW) and superconductivity in LaPt2(Si1-x Ge x )2 has been studied by electrical transport and magnetic measurements. LaPt2Si2 crystallizes in CaBe2Ge2 type structure which shows a first order structural phase transition from tetragonal to orthorhombic accompanied by a CDW transition at 112 K and superconducting transition at around 1.22 K as confirmed by temperature dependence of resistivity and magnetic measurements. For 2[Formula: see text] doping of germanium, while the CDW temperature T CDW decreases, the superconducting transition temperature T C shows an increase. T CDW increases for 5[Formula: see text] doping of germanium and the superconducting transition decreases. These findings demonstrate the competing nature of a CDW and superconductivity.

Valence fluctuation and magnetic ordering in EuNi2(P(1-x)Ge(x))2 single crystals

Unusual phases and phase transitions are seen at the magnetic-nonmagnetic boundary in Ce-, Eu- and Yb-based compounds. EuNi2P2 is a very unusual valence fluctuating Eu system, because at low temperatures the Eu valence stays close to 2.5 instead of approaching an integer value. The Eu valence, and thus the magnetic property in this system, can be tuned by Ge substitution in the P site as EuNi2Ge2 is known to exhibit the antiferromagnetc (AFM) ordering of divalent Eu moments with T(N)=30K. We have grown EuNi2(P(1-x)Ge(x))2 (0.0≤ x ≤0.5)) single crystals and studied their magnetic, thermodynamic and transport properties. Increasing Ge doping to x  >  0.4 results in a well-defined AFM ordered state with T(N)=12K for x  =  0.5. Moreover, the reduced value of magnetic entropy for x  =  0.5 at T(N) suggests the presence of valance fluctuation/the Kondo effect in this compound. Interestingly, the specific heat exhibits an enhanced Sommerfeld coefficient upon Ge doping. Subsequently, electronic structure calculations lead to a non-integral valence in EuNi2P2 but a stable divalent Eu state in EuNi2Ge2, which is in good agreement with the experimental results.

Congenital dermoid inclusion cyst over the anterior fontanelle: report of two cases

Congenital dermoid inclusion cyst over the anterior fontanelle (CDIC) is an uncommon cystic lesion. It is a benign and curative lesion. In these two cases a soft, cystic mass located over the anterior fontanelle. The cyst had no intracranial extension and was easily excised intact. The clinical and image findings of the cysts were described and compared with the usual dermoids. Many different types of lesions over the children's skull exist and some are commonly diagnosed in daily practice. Congenital dermoid inclusion cyst over the anterior fontanelle (CDIC) is a rare and benign lesion.Pulse Vol.7 January-December 2014 p.42-45

Muon spin relaxation study on itinerant ferromagnet CeCrGe₃ and the effect of Ti substitution on magnetism of CeCrGe₃

A Muon spin relaxation (µSR) study has been performed on the Kondo lattice heavy fermion itinerant ferromagnet CeCrGe3. Recent investigations of bulk properties have revealed a long-range ordering of Cr moments at Tc = 70 K in this compound. Our µSR investigation between 1.2 K and 125 K confirm the bulk magnetic order which is marked by a loss in initial asymmetry below 70 K accompanied with a sharp increase in the muon depolarization rate. Field dependent µSR spectra show that the internal field at the muon site is higher than 0.25 T apparently due to the ferromagnetic nature of ordering. The effect of Ti substitution on the magnetism in CeCrGe3 is presented. A systematic study has been made on polycrystalline CeCr(1-x)Ti(x)Ge3 (0 ⩽ x ⩽ 1) using magnetic susceptibility χ(T), isothermal magnetization M(H), specific heat C(T) and electrical resistivity ρ(T) measurements which clearly reveal that the substitution of Ti for Cr in CeCrGe3 strongly influences the exchange interaction and ferromagnetic ordering of Cr moments. The Cr moment ordering temperature is suppressed gradually with increasing Ti concentration up to x = 0.50 showing Tc = 7 K beyond which Ce moment ordering starts to dominate and a crossover between Cr and Ce moment ordering is observed with a Ce moment ordering Tc = 14 K for x = 1.0. The Kondo lattice behavior is evident from temperature dependence of ρ(T) in all CeCr(1-x)Ti(x)Ge3 samples.

Heavy fermion and Kondo lattice behavior in the itinerant ferromagnet CeCrGe3

Physical properties of polycrystalline CeCrGe3 and LaCrGe3 have been investigated by x-ray absorption spectroscopy, magnetic susceptibility χ(T), isothermal magnetization M(H), electrical resistivity ρ(T), specific heat C(T) and thermoelectric power S(T) measurements. These compounds are found to crystallize in the hexagonal perovskite structure (space group P63/mmc), as previously reported. The ρ(T), χ(T) and C(T) data confirm the bulk ferromagnetic ordering of itinerant Cr moments in LaCrGe3 and CeCrGe3 with TC = 90 K and 70 K respectively. In addition, a weak anomaly is also observed near 3 K in the C(T) data of CeCrGe3. The T dependences of ρ and finite values of Sommerfeld coefficient γ obtained from the specific heat measurements confirm that both the compounds are of metallic character. Further, the T dependence of ρ of CeCrGe3 reflects a Kondo lattice behavior. An enhanced γ of 130 mJ mol(-1) K(-2) together with the Kondo lattice behavior inferred from the ρ(T) establish CeCrGe3 as a moderate heavy fermion compound with a quasi-particle mass renormalization factor of ∼45.

Purification of glucoamylase fromAspergillus terreus

Glucoamylase from a rice bran culture ofAspergillus terreus was purified by chromatography on DEAE-cellulose and concanavatin A-Sepharose. A homogenous monomer resulted after SDS-PAGE electrophoresis. The enzyme was a glycoprotein, molecular weight, 86,000 with 7.5% (w/w) carbohydrate content.

A temperature dependent tunneling study of the spin density wave gap in EuFe2As2 single crystals

We report temperature dependent scanning tunneling microscopy and spectroscopy measurements on single crystals of EuFe2As2 in the 15-292 K temperature range. The in situ cleaved crystals show atomic terraces with homogeneous tunnel spectra that correlate well with the spin density wave (SDW) transition at a temperature, TSDW ≈ 186 K. Above TSDW the local tunnel spectra show a small depression in the density of states (DOS) near the Fermi energy (EF). The gap becomes more pronounced upon entering the SDW state with a gap value ∼90 meV at 15 K. However, the zero bias conductance remains finite down to 15 K indicating a finite DOS at the EF in the SDW phase. Furthermore, no noticeable change is observed in the DOS at the antiferromagnetic ordering transition of Eu(2+) moments at 19 K.

Enhancement of reproductive performances of Gangetic leaffish, Nandus nandus through up regulation of serum Ca²⁺ concentration, improved morphological alteration of liver and ovary with dietary polyunsaturated fatty acids

Incorporation of polyunsaturated fatty acids (PUFAs) as biofunctional compounds with feed is an effective way for gonadal maturation without any hazardous effects on animal health, and thus it is possible to save the vulnerable species from the danger of extinction. In the present study sperm quality, level of Ca(2+) concentration in serum, histological structure of the liver and developmental stages of ovary of an endangered fish species, Nandus nandus were investigated for the confirmation of the positive effects of PUFAs in reproduction and gonadal maturation. Fishes were collected from Brahmaputra River, Mymensingh, Bangladesh. Treated group was fed 1% squid extracted phospholipid supplemented diet that was mixed with silver carp fish muscle where as controlled group was fed the same except phospholipid. For histology of liver and gonads, samples were dehydrated, cleaned and infiltrated, embedded in paraffin wax and sectioned. After that, the samples were stained with hematoxylin and eosin. The photomicrographs of the stained samples were taken by using light microscope. In comparison with the control group, treated group exhibited higher gonadal maturation which resulted in spontaneous spawning. Treated female demonstrated advanced gonadal developmental stages in comparison with the controlled female during different months. During spawning season, lipid granules and normal morphological alteration were observed in case of treated fish liver, whereas less lipid granules with more histological alteration of liver were observed in control group. Serum Ca(2+) concentration in treated female was found significantly higher (P < 0.01) in contrast to the controlled female during the breeding season which was an indicator of the augment of estrogen secretion during ovarian maturation. Better sperm quality, early maturation of oocytes, less histological alteration of liver hepatocytes and spontaneous spawning performances of PUFA-treated fish were as a result of the efficiency of PUFAs in enhancing maturation. The experiment suggests that supplementation of dietary PUFAs improve the spawning performances of fish.

Reentrant superconductivity in Eu(Fe(1-x)Ir(x))2As2

The interplay between superconductivity and Eu(2+) magnetic ordering in Eu(Fe1-xIrx)2As2 is studied by means of electrical transport and magnetic measurements. For the near optimally doped sample Eu(Fe0.86Ir0.14)2As2, we witnessed two distinct transitions: a superconducting transition below 22.6 K which is followed by a resistivity reentrance caused by the ordering of the Eu(2+) moments. Further, the low field magnetization measurements show a prominent diamagnetic signal due to superconductivity, which is remarkable in the presence of a large-moment magnetically ordered system. The electronic structure for 12.5% Ir doped EuFe1.75Ir0.25As2 is investigated along with the parent compound EuFe2As2. As compared to EuFe2As2, the doped compound has an effectively lower value of density of states throughout the energy scale with a more extended bandwidth and stronger hybridization involving Ir. Shifting of the Fermi energy and a change in band filling in EuFe1.75Ir0.25As2 with respect to the pure compound indicate electron doping in the system.

Complex magnetic order in Pr₂Pd₃Ge₅: a single crystal study

We have investigated the magnetic and electronic transport properties of single crystal Pr(2)Pd(3)Ge(5) grown by the Czochralski method. Complex magnetic behaviour (multiple magnetic transitions) is clearly seen in this compound from the magnetic susceptibility χ(T), isothermal magnetization M(H) and electrical resistivity ρ(T) data. For the magnetic field applied along the crystallographic c-axis (H ‖ [001]) the χ(T) data exhibit two sharp transitions at 6.9 and 6.3 K and a broad hump near 8 K. Four anomalies at 8.0, 7.3, 6.2 and 4.9 K are observed for the magnetic field along both a- and b-directions (H ‖ [100] and H ‖ [010]). Further, the ordered state χ(T) presents a large anisotropy with an easy axis along the c-axis. The presence of magnetocrystalline anisotropy is also inferred from the isothermal M(H) data. The M(H) data measured at 1.9 K for H ‖ [001] exhibit a step-like increase due to field-induced metamagnetic transitions at [Formula: see text] T and [Formula: see text] T. For H ‖ [100] and H ‖ [010] sharp step-like field-induced metamagnetic transitions occur at [Formula: see text] T and [Formula: see text] T which are accompanied by a weak S-shaped spin-flop metamagnetic transition at [Formula: see text] T. We have extracted the H-T phase diagram from the M(H) data collected at different temperatures in the magnetically ordered state which shows the existence of three magnetic phases below T(N) for H ‖ [100] and H ‖ [010], and two magnetic phases for H ‖ [001]. A sharp transition due to the onset of long range antiferromagnetic order is also seen in the ρ(T) data which also exhibit anisotropic behaviour. The observation of an upturn near T(N) in the ρ(T) data suggests the formation of a super-zone gap and hence the existence of incommensurate magnetic structure. Further, in the ordered state, the ρ(T) data present a gap in the excitation spectrum of magnons with a characteristic energy gap Δ ∼ 0.23 meV.

Magnetic behavior of Eu(3)Ni(4)Ga(4): antiferromagnetic order and large magnetoresistance

The results of the magnetic susceptibility, isothermal magnetization, heat capacity, electrical resistivity and magnetoresistance measurements on polycrystalline Eu(3)Ni(4)Ga(4) are presented. Eu(3)Ni(4)Ga(4) forms in Na(3)Pt(4)Ge(4)-type cubic crystal structure (space group [Formula: see text]). The temperature dependence of the magnetic susceptibility of Eu(3)Ni(4)Ga(4) confirms the divalent state (Eu(2+)) of Eu ions with an effective magnetic moment μ(eff) = 7.98 μ(B). At low fields, e.g. at 0.01 T, a magnetic phase transition to an antiferromagnetically ordered state occurs at T(N) = 10.9 K, which is further confirmed by the temperature dependence of the heat capacity and electrical resistivity. The field dependence of isothermal magnetization at 2 K reveals the presence of two field induced metamagnetic transitions at H(c1) and H(c2) = 0.55 and 1.2 T, respectively and a polarized phase above H(PO) = 1.7 T. The reduced jump in the heat capacity at the transition temperature, ΔC|(T(N)) = 13.48 J/mol-Eu K would indicate an amplitude modulated (AM) antiferromagnetic structure. An interesting feature is that a large negative magnetoresistance, MR = [ρ(H) - ρ(0)]/ρ(0), is observed in the vicinity of magnetic transition even up to 2T(N). Similar large magnetoresistance has been observed in the paramagnetic state in some Gd and Eu based alloys and has been attributed to the magneto-polaronic effect.

Doping dependent evolution of magnetism and superconductivity in Eu(1-x)K(x)Fe2As2 (x = 0-1) and temperature dependence of the lower critical field H(c1)

We have synthesized polycrystalline samples of Eu(1-x)K(x)Fe2As2 (x = 0-1) and carried out systematic characterization using x-ray diffraction, ac and dc magnetic susceptibility, and electrical resistivity measurements. A clear signature of the coexistence of a superconducting transition (T(c) = 5.5 K) with spin density wave (SDW) ordering is observed in our underdoped sample with x = 0.15. The SDW transition disappears completely for the x = 0.3 sample and superconductivity arises below 20 K. The superconducting transition temperature Tc increases with increase in the K content and a maximum Tc = 33 K is reached for x = 0.5, beyond which it decreases again. The doping dependent Tx phase diagram is extracted from the magnetic and electrical transport data. It is found that magnetic ordering of Eu moments coexists with the superconductivity up to x = 0.6. The isothermal magnetization data taken at 2 K for the doped samples suggest the 2+ valence state of the Eu ions. We also present the temperature dependence of the lower critical field H(c1) of the superconducting polycrystalline samples. The values of H(c1)(0) obtained for x = 0.3, 0.5, and 0.7 after taking the demagnetization factor into account are 202, 330, and 212 Oe, respectively. The London penetration depth λ(T) calculated from the lower critical field does not show exponential dependence at low temperature, as would be expected for a fully gapped clean s-wave superconductor. In contrast, it shows a T2 power law feature up to T = 0.3Tc, as observed in Ba(1-x)K(x)Fe2As2 and BaFe(2-x)Co(x)As2.

Signatures of spin-glass behaviour in PrIr2B2 and heavy fermion behaviour in PrIr2B2C

The magnetic and transport properties of PrIr(2)B(2) and PrIr(2)B(2)C have been investigated by dc and ac magnetic susceptibility, specific heat, electrical resistivity and magnetoresistance measurements. PrIr(2)B(2) forms in CaRh(2)B(2)-type orthorhombic crystal structure (space group Fddd). At low fields the dc magnetic susceptibility of PrIr(2)B(2) exhibits a sharp anomaly near 46 K which is followed by an abrupt increase below 10 K with a peak at 6 K, and split-up in ZFC and FC data below 46 K. In contrast, the specific heat exhibits only a broad Schottky type hump near 9 K which indicates that there is no long range magnetic order in this compound. The thermo-remanent magnetization is found to decay very slowly with a mean relaxation time τ = 3917 s. An ac magnetic susceptibility measurement also observes two sharp anomalies; the peak positions strongly depend on the frequency and shift towards high temperature with an increase in frequency, obeying the Vogel-Fulcher law as expected for a canonical spin-glass system. The two spin-glass transitions occur at freezing temperatures T(f1) = 36 K and T(f2) = 3.5 K with shifts in the freezing temperatures per decade of frequency δT(f1) = 0.044 and δT(f2) = 0.09. An analysis of the frequency dependence of the transition temperature with critical slowing down, τ(max)/τ(0) = [(T(f)-T(SG))/T(SG)](-zν), gives τ(0) = 10(-7) s and exponent zν = 8, and the Vogel-Fulcher law gives an activation energy of 84 K for T(f1) and 27.5 K for T(f2). While zν = 8 is typical for spin-glass system, the characteristic relaxation time τ(0) = 10(-7) s is very large and comparable to that of superspin-glass systems. An addition of C in PrIr(2)B(2) leads to PrIr(2)B(2)C which forms in LuNi(2)B(2)C-type tetragonal structure (space group I4/mmm) and remains paramagnetic down to 2 K. The specific heat data show a broad Schottky type anomaly, which could be fairly reproduced with CEF analysis which suggests that the ground state is a CEF-split singlet and the first excited state singlet is situated 15 K above the ground state. The Sommerfeld coefficient γ∼300 mJ mol(-1) K(-2) of PrIr(2)B(2)C is very high and reflects a heavy fermion behaviour in this compound. We believe that the heavy fermion state in PrIr(2)B(2)C has its origin in low lying crystal field excitations as has been observed in PrRh(2)B(2)C.

Suppression of quadrupolar order on Si doping in YbRu(2)(Ge(1 - x)Si(x))(2)

We have investigated the magnetic properties of polycrystalline Y bRu(2)(Ge(1 - x)Si(x))(2) samples using magnetic susceptibility, electrical resistivity, and specific heat measurements. All the results indicate that the Yb ions in Y bRu(2)(Ge(1 - x)Si(x))(2) are in a stable trivalent state. The antiferromagnetic ordering shifts to lower temperature with increasing Si concentration (x). The weak Kondo-like resistivity minimum observed in the resistivity data for x = 0 shifts toward lower temperature with an increase in the Si content and finally disappears. The most dramatic observation is the complete suppression of the quadrupolar ordering in Y bRu(2)Ge(2) (T(Q) = 10 K) even for 2% Si doping.

(11)B and (195)Pt NMR study of heavy-fermion compound CePt(2)B(2)C

We report (11)B and (195)Pt NMR Knight shift K and spin-lattice relaxation rate 1/T(1) in CePt(2)B(2)C in the range 4-315 K. The quadrupolar coupling constant, ν(Q) for boron nuclei is 790 ± 10 kHz. The change of hyperfine field, H(hf), is observed below 30 K in the K versus susceptibility, χ, plot. The calculated value of H(hf) at the (11)B ((195)Pt) is 0.156 (6.86) kOe/μ(B) in the range 30-300 K and ∼0 (0.22) kOe/μ(B) below 30 K. The 1/T(1) versus T curve shows some exotic behavior. The Ce 4f spin contribution to the nuclear relaxation rate (1/T(1f)) in each case is obtained by subtracting the T(1K)(-1) estimated from its La analog, i.e. LaPt(2)B(2)C. In the case of (11)B resonance, in the temperature range of 300-100 K, (1/T(1f)) is independent of T, suggesting a Curie-Weiss behavior of the imaginary part of the dynamic susceptibility. It then shows a slow but continuous increment in the range 100-70 K, indicating a signature of the development of short-range magnetic correlation among the Ce 4f spins. Below 70 K, this enhancement of 1/T(1f) is completely suppressed and it decreases sharply, indicating a suppression of the effect of magnetic correlation, due to the dominance of the Kondo effect over the RKKY interaction. 1/T(1f), follows ∼T(α), with an exponent α∼0.7 in the range 4-30 K for (195)Pt and in the range 8-30 K for (11)B resonance. This is a characteristics of a non-Fermi-liquid like behavior. However, in the case of (11)B, there is again a clear change in the slope of the 1/T(1f) versus T curve below 8 K, with the value of α = 1.0, as if the behavior of the conduction electrons approaches towards a Fermi liquid, when probed near the (11)B site.

Superconductivity and magnetism in K-doped EuFe(2)As(2)

Superconductivity is found in 50% K-doped EuFe(2)As(2) samples below 33 K. Our results from electrical resistivity, magnetic susceptibility and (57)Fe and (151)Eu Mössbauer spectroscopy provide clear evidence that the ordering of the Fe moments observed at 190 K in undoped EuFe(2)As(2) is completely suppressed in our 50% K-doped sample; thus there is no coexistence of the Fe magnetic order and the superconducting state. However, short range ordering of the Eu moments coexists with the superconducting state below 15 K. A bump in the susceptibility well below T(c) as well as the broadening of the Fe Mössbauer line below 27 K evidence an interplay between the Eu magnetism and the superconducting state.

YbNiB(4): a Kondo lattice with low-dimensional antiferromagnetic fluctuations

We have grown single crystals of YbNiB(4) using a Ni(60)B(40) flux and determined the magnetic properties of this compound by means of magnetic susceptibility, specific heat and electrical resistivity measurement. Yb ions in YbNiB(4) are in a trivalent state and present a transition from a paramagnetic state to an antiferromagnetic (AF) state at T(N1) = 5.4 K and a further transition towards a second AF state at T(N2) = 4.0 K. Kondo type behavior in the resistivity and an enhanced Sommerfeld coefficient γ = 100 mJ mol(-1) K(-2) provide evidence for a significant Kondo interaction. A broad maximum in χ(T) at around 8 K, well above T(N1), suggests low-dimensional antiferromagnetic correlations. Both mechanisms lead to strong fluctuation in an extended temperature range above T(N1), up to the characteristic energy of this system, which was estimated to be T(4f) = 16 K from an analysis of the entropy.

Photoemission insight into heavy-fermion behavior in YbRh2Si2

As shown by angle-resolved photoemission (PE), hybridization of bulk Yb 4f(2+) states with a shallow-lying valence band of the same symmetry leads in YbRh2Si2 to dispersion of a 4f PE signal in the region of the Kondo resonance with a Fermi-energy crossing close to Gamma[over ]. Additionally, renormalization of the valence state results in the formation of a heavy band that disperses parallel to the 4f originating signal. The symmetry and character of the states are probed by circular dichroism and the photon-energy dependence of the PE cross sections.

Evaluation of stentangioplasty in university cardiac center

In this ongoing prospective study conducted in University Cardiac Center, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from July 2004 to January 2006. Fifty (50) patients (mean age 56+/-7.2 years) underwent stentangioplasty were evaluated. The study group of 50 patients consisted of 42 (84%) men and 08 (16%) women. The aim of this study was to evaluate in-hospital success, failure and complications during the procedures. About risk factors 19(38%) had hypertension, 13(26%) were smoker, 11(22%) suffered from diabetes mellitus, 05(10%) had family history of ischaemic heart disease. Average left ventricular ejection fraction was 54+/-7. Target vessel percutaneous coronary angioplasty (PTCA) were done in 61 vessel, intracoronary stent implanted in 58 vessels, direct stenting were done in 35 cases, failed PTCA were in 03(6%) cases and two had dissection. The native vessels had a mean reference diameter of 2.91 mm and their luminal diameter increased significantly after percutaneous coronary intervention (PCI). All the patients were discharged by one to three days of the procedure with improvement of their clinical condition. In conclusion, intracoronary stent deployment in coronary artery stenosis following balloon angioplasty is a valid and beneficial strategy with good in-hospital results.

Doppler evaluation of left to right shunt (Qp/Qs) in patients with isolated ventricular septal defect (Vsd)

A prospective observational study was carried out in the department of cardiology, Bangabandhu Sheikh Mujib Medical University (BSMMU) in collaboration with the department of cardiology, Combined Military Hospital (CMH), Dhaka from January 2000 to October 2001. All the patients were clinically evaluated. ECG & Doppler echocardiography were done.All the patients underwent cardiac catheterization. Complex congenital heart disease & cyanotic heart disease patients were excluded from the study. Doppler estimated pulmonary to systemic blood flow ratio (Qp/Qs) was done by conventional (velocity time integral method) method. In cardiac catheterization Qp/Qs ratio derived from oximetric data which has become a well established part of clinical practice. Doppler derived Qp/Qs were compared with catheter derived Qp/Qs. 30 patients with VSD were included. In those patients Doppler derived Qp/Qs ranged from maximum 4.5 to minimum 1.10. Mean (+/-SD) was 1.88+/-0.86 In patients with VSD mean (+/-SD) Qp/Qs at catheterization was 1.80+/-0.80. Qp/Qs ranged from maximum 4.10 to minimum 1.1 In those patients the correlation coefficient for invasively determined Qp/Qs versus Doppler estimated Qp/Qs was .92 (standard error of estimate [SEE] = 0.19) & the line of regression passed close to the origin. The results of this study demonstrate that The Doppler technique allows the noninvasive evaluation of Qp/Qs with a high degree of accuracy & allows determination of the stage of VSD by the consecutive assessment of shunt magnititude.

Development of NaCl-tolerant strain in Chrysanthemum morifolium Ramat. through in vitro mutagenesis

One NaCl-tolerant chrysanthemum (Chrysanthemum morifolium Ramat.) variant (E2) has been developed in a stable form through IN VITRO mutagenesis using ethylmethane sulfonate (EMS) as the chemical mutagen. Salt tolerance was evaluated by the capacity of the plant to maintain both flower quality and yield under stress conditions. Enhanced tolerance of the E2 variant has been attributed to the increased activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), and dehydroascorbate reductase (DHAR), and, to a lesser extent of membrane damage than NaCl-treated control plants. Isoform analysis revealed that an increase in total SOD activity in the E2 variant was solely due to significant activation of the Cu/Zn isoform. Elevated levels of carotenoids and ascorbate in E2 leaves have been reflected in their higher free radical scavenging capacity (RSC) expressed in terms of DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging ability. Data reflect that a proper balance between enzymatic and non-enzymatic defence systems is required for combating salinity stress in chrysanthemum. Better performance of the E2 progeny under same salinity stress condition, even in the second year, confirms the genetic stability of the salt-tolerance character. On the whole, the E2 variant, developed through 0.025 % EMS treatment, might be considered as a NaCl-tolerant strain showing positive characters towards NaCl stress.

Energy dispersion of 4f-derived emissions in photoelectron spectra of the heavy-fermion compound YbIr2Si2

Angle-resolved photoemission spectra of the heavy-fermion system YbIr(2)Si(2) are reported that reveal strong momentum (k) dependent splittings of the 4f(13) bulk and surface emissions around the expected intersection points of the 4f final states with valence bands in the Brillouin zone. The obtained dispersion is explained in terms of a simplified periodic Anderson model by a k dependence of the electron hopping matrix element disregarding clearly interpretation in terms of a single-impurity model.

Intrathoracic migration of a humeral orthopedic pin

Intrathoracic migration of orthopedic fixation pins occurs infrequently but can have dire consequences if not recognized. Described herein is the case of an orthopedic pin that migrated from the proximal humerus into lung parenchyma. After preoperative computed tomography and fluoroscopy, the pin was removed via thoracotomy.

Depressed mothers' touching increases infants' positive affect and attention in still-face interactions

The effects of depressed mothers' touching on their infants' behavior were investigated during the still-face situation. 48 depressed and nondepressed mothers and their 3-month-old infants were randomly assigned to control and experimental conditions. 4 successive 90-sec periods were implemented: (A) normal play, (B) still-face-no-touch, (C) still-face-with-touch, and (A) normal play. Depressed and nondepressed mothers were instructed and shown how to provide touch for their infants during the still-face-with-touch period. Different affective and attentive responses of the infants of depressed versus the infants of nondepressed mothers were observed. Infants of depressed mothers showed more positive affect (smiles and vocalizations) and gazed more at their mothers' hands during the still-face-with-touch period than the infants of nondepressed mothers, who grimaced, cried, and gazed away from their mothers' faces more often. The results suggest that by providing touch stimulation for their infants, the depressed mothers can increase infant positive affect and attention and, in this way, compensate for negative effects often resulting from their typical lack of affectivity (flat facial and vocal expressions) during interactions.

The health effects of ionizing radiation: a survey of local health officials in New England and New York

The purpose of the study is to determine the educational needs of public health officials concerning their knowledge, attitude, beliefs, and practices with specific reference to ionizing radiation. The public health directors or designates, working in health departments whose jurisdictions fall within a 60-mile radius of the 14 operating nuclear power plants in the New York-New England region, were studied. A review of the literature indicates that historically there appears to have been a limited effort to conduct such a needs assessment in the United States. A questionnaire was developed to measure the public health directors' knowledge, attitudes, and practice. The instrument was mailed in the summer of 1992 to all public officials listed in the National Directory of Local Health Departments. Knowledge, attitude, and practice questions were analyzed in terms of frequency of correct, incorrect, and don't know responses. The data presented convey the message that there should be public input into the risk assessment of nuclear plants and that local health departments should inform the public about the health risks posed by nuclear plants in their locality. The authors recommend that an appropriate Federal agency sponsor a national survey and that States should establish a training program on the health effects of ionizing radiation for local public health officials.