Pressure-Induced Enhanced Optical Absorption in Sulvanite Compound Cu3TaX4 (X = S, Se, and Te): An ab Initio Study

Ab initio study on the family of ternary copper chalcogenides Cu₃TaX₄ (X = S, Se, and Te) is performed to investigate the suitability of these compounds to applications as photovoltaic absorber materials. The density functional theory based full potential linearized augmented plane wave method (FP-LAPW method) is employed for computational purposes. The electronic structure and optical properties are determined including electron-electron interaction and spin-orbit coupling (SOC), within the generalized gradient approximation plus Hubbard U (GGA+U) and GGA+U+SOC approximation. The large optical band gaps of Cu₃TaS₄ and Cu₃TaSe₄ considered ineffective for absorber materials, and also the hole effective mass has been modulated through applied pressure. These materials show extreme resistance to external pressure, and are found to be stable up to a pressure range of 10 GPa, investigated using phonon dispersion calculations. The observed optical properties and the absorption coefficients within the visible-light spectrum make these compounds promising materials for photovoltaic applications. The calculated energy and optical band gaps are consistent with the available literature and are compared with the experimental results where available.

Electronic and thermoelectric properties of Nd-doped Ce-filled skutterudites

The electronic and thermoelectric properties of Nd-doped Ce-filled skutterudites (CeFe₄P₁₂, CeFe₄As₁₂, and CeOs₄P₁₂) were explored using full-potential linearized augmented plane waves (FP-LAPW). The exchange-correlation between the electrons was treated with the generalized gradient approximation of Perdew-Burke-Ernzerhof (PBE) and the Coulomb repulsion term (U) between the electrons for the highly correlated system was also considered. The energy band structures revealed the semiconducting nature with energy gaps of 0.42 eV, 0.25 eV and 0.22 eV for CeFe₄P₁₂, CeFe₄As₁₂, and CeOs₄P₁₂, respectively. The phonon dispersion curve displayed the forbidden gap between the optical and acoustic modes in CeFe₄P₁₂ and CeOs₄P₁₂. The analysis of n-type and p-type doping on pure alloys suggest enhanced thermoelectric behavior in p-type doping on pure alloys and hence the addition of Nd at the central cage atomic site generates flat and dense bands at E_F and also opens an optical band gap in doped CeOs₄P₁₂. Moreover, the Nd atom introduces strong phonon scattering and hence reduces the lattice thermal conductivity (K_L) substantially from 6.79 W m^-1 K^-1 to 3.47 W m^-1 K^-1 for CeFe₄P₁₂, 3.63 W m^-1 K^-1 to 1.97 W m^-1 K^-1 for CeFe₄As₁₂ and 6.43 W m^-1 K^-1 to 2.58 W m^-1 K^-1 for CeOs₄P₁₂ at room temperature. A considerably amplified figure of merit has been observed for the doped sample materials with the highest value of 0.72 at 800 K for doped CeFe₄P₁₂ with the highest Seebeck coefficient of 215.51 μV K^-1.

Investigation of mechanical, thermodynamical, dynamical and electronic properties of RuYAs (YCr and Fe) alloys

Investigation of structural, dynamical, mechanical, electronic and thermodynamic properties of RuYAs (Y= Cr and Fe) alloys have been performed from the first principle calculations. Among the three structural phases, 'α' phase is found to be energetically favorable for both the RuCrAs and RuFeAs compounds. The computed cohesive energies and phonon dispersion spectra indicate the structural and dynamical stabilities of both the compounds. Mechanical stability of these compounds are studied using elastic constants. The Pugh's ratio predicts RuFeAs to be more ductile than RuCrAs. The RuCrAs alloy, on the other hand, is found to be a stiffer, harder and highly rigid crystal with stronger bonding forces than the RuFeAs. Furthermore, the thermodynamical properties have also been estimated with respect to the temperature under different pressures using the quasi-harmonic Debye model. In order to account for the effect of the highly correlateddtransition elements in the system we incorporated the GGA +Uapproximations. Within the GGA +Uapproach, the electronic structure reveals the half-metallicity for both compounds, which follows the Slater-Pauling rule. The charge density and electron localized function reflect the covalent bonding among the constituent atoms. Bader analysis reveals that the charge transfer takes place from Cr/Fe to Ru and As atoms in both approximations. Both Raman and infrared active modes have been identified in the compounds.

Modulation of optical absorption in m-Fe1-xRuxS2 and exploring stability in new m-RuS2

A first-principle computational method has been used to investigate the effects of Ru dopants on the electronic and optical absorption properties of marcasite FeS2. In addition, we have also revealed a new marcasite phase in RuS2, unlike most studied pyrite structures. The new phase has fulfilled all the necessary criteria of structural stability and its practical existence. The transition pressure of 8 GPa drives the structural change from pyrite to orthorhombic phase in RuS2. From the thermodynamical calculation, we have reported the stability of new-phase under various ranges of applied pressure and temperature. Further, from the results of phonon dispersion calculated at Zero Point Energy, pyrite structure exhibits ground state stability and the marcasite phase has all modes of frequencies positive. The newly proposed phase is a semiconductor with a band gap comparable to its pyrite counterpart but vary in optical absorption by around 106 cm-1. The various Ru doped structures have also shown similar optical absorption spectra in the same order of magnitude. We have used crystal field theory to explain high optical absorption which is due to the involvement of different electronic states in formation of electronic and optical band gaps. Lӧwdin charge analysis is used over the customarily Mulliken charges to predict 89% of covalence in the compound. Our results indicate the importance of new phase to enhance the efficiency of photovoltaic materials for practical applications.

Half-metallicity in new Heusler alloys Mn2ScZ (Z = Si, Ge, Sn)

Study of half-metallicity has been performed in a new series of Mn₂ScZ (Z = Si, Ge and Sn) full Heusler alloys using density functional theory with the calculation and implementation of a Hubbard correction term (U). Volume optimization in magnetic and non-magnetic phases for both the Cu₂MnAl and Hg₂CuTi type structures was done to predict the stable ground state configuration. The stability was determined by calculating their formation energy as well as from elastic constants under ambient conditions. A half-metal is predicted for Mn₂ScSi and Mn₂ScGe with a narrow band gap in the minority spin whereas Mn₂ScSn shows a metallic nature. The magnetic moments of Mn and Sc are coupled in opposite directions with different strengths indicating that the ferrimagnetic order and the total magnetic moment per formula unit for half-metals follows the Slater Pauling rule. And a strong effect was shown by the size of the Z element in the electronic and magnetic properties.

Study of half-metallicity has been performed in a new series of Mn₂ScZ (Z = Si, Ge and Sn) full Heusler alloys using density functional theory with the calculation and implementation of a Hubbard correction term (U).

Amniotic fluid volume at presentation with early preterm prelabor rupture of membranes and association with severe neonatal respiratory morbidity

OBJECTIVE

Amniotic fluid volume (AFV) plays an important role in early fetal lung development, and oligohydramnios in early pregnancy is associated with pulmonary hypoplasia. The aim of this study was to evaluate the association between AFV at the time of presentation with early preterm prelabor rupture of membranes (PPROM) and severe neonatal respiratory morbidity and other adverse pregnancy outcomes.

METHODS

This was a retrospective study of all women with a singleton pregnancy, admitted to a single tertiary referral center between 2004 and 2014, for expectant management of PPROM at 20 + 0 to 28 + 6 weeks' gestation. The primary exposure was AFV at presentation, classified according to sonographic maximum vertical pocket (MVP) as: normal AFV (> 2 cm), oligohydramnios (≤ 2 cm and > 1 cm) or severe oligohydramnios (≤ 1 cm). The primary outcome was a composite variable of severe respiratory morbidity, defined as either of the following: (1) need for respiratory support in the form of mechanical ventilation using an endotracheal tube for ≥ 72 h and need for surfactant; or (2) bronchopulmonary dysplasia, defined as requirement for oxygen at postmenstrual age of 36 weeks or at the time of transfer to a Level-II facility. Adjusted odds ratios (aOR) and 95% CI for the primary and secondary outcomes were calculated for each AFV-at-presentation group (using normal AFV as the reference), adjusting for gestational age (GA) at PPROM, latency period, birth weight, mode of delivery and chorioamnionitis.

RESULTS

In total, 580 women were included, of whom 304 (52.4%) had normal AFV, 161 (27.8%) had oligohydramnios and 115 (19.8%) had severe oligohydramnios at presentation. The rates of severe respiratory morbidity were 16.1%, 26.7% and 45.2%, respectively. Compared with normal AFV at presentation, oligohydramnios (aOR, 3.27; 95% CI, 1.84-5.84) and severe oligohydramnios (aOR, 4.11; 95% CI, 2.26-7.56) at presentation were associated independently with severe respiratory morbidity. Other variables that were associated independently with the primary outcome were GA at PPROM (aOR, 0.54; 95% CI, 0.43-0.69), latency period (aOR, 0.94; 95% CI, 0.91-0.98) and Cesarean delivery (aOR, 2.01; 95% CI, 1.21-3.32).

CONCLUSIONS

In women with early PPROM, AFV at presentation, as assessed by the MVP on ultrasound examination, is associated independently with severe neonatal respiratory morbidity. This information may be taken into consideration when counseling women with early PPROM regarding neonatal outcome and management options. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Study of half metallicity, structural and mechanical properties in inverse Heusler alloy Mn2ZnSi(1-x)Ge x and a superlattice

The electronic and magnetic properties of Mn₂ZnSi_(1−x)Ge_x (x = 0.0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, and 1.0) inverse Heusler alloys and Mn₂ZnSi/Mn₂ZnGe superlattice have been investigated using first-principles calculations. All these alloys are stable in the fcc magnetic phase and satisfies the mechanical and thermal stability conditions as determined from the elastic constants and negative formation energy. The spin-polarized electronic band structures and the density of states indicate half-metallicity with 100% spin polarization at the Fermi energy level for x = 0.0, 0.125, 0.25, 0.50, and 1.0, with the integral values of the total magnetic moments per formula unit at their equilibrium lattice constants, following the Slater–Pauling rule. The electronic properties and the magnetic moments are mostly contributed by two Mn atoms and are coupled anti-parallel to each other, making them ferrimagnetic in nature. The presence of the half-metallic bandgap with an antiparallel alignment of Mn atoms makes these Heusler alloys a potential candidate for spintronic applications.

The electronic and magnetic properties of Mn₂ZnSi_(1−x)Ge_x (x = 0.0, 0.125, 0.25, 0.375, 0.5, 0.625, 0.75, 0.875, and 1.0) inverse Heusler alloys and Mn₂ZnSi/Mn₂ZnGe superlattice have been investigated using first-principles calculations.

Quercetin accelerated cutaneous wound healing in rats by increasing levels of VEGF and TGF-β1

Quercetin (3,3',4',5,7-penthydroxyflavone)-induced biological effects have been beneficial in various disease conditions. In this study, wound healing potential of quercetin was evaluated in a time-dependent manner in open excision wounds in adult Wistar rats. Experimentally-wounded rats were divided into two groups namely, control and quercetin-treated. Wounds were photographed and the area was measured on the day of wounding and on days 3, 7, 11 and 14 post-wounding. The granulation/healing tissue was collected on days 3, 7, 11 and 14 post-wounding for cytokine/growth factor measurements and histology/immunohistochemistry studies. There was significant time-dependent increase in wound closure in quercetin-treated rats. Vascular endothelial growth factor and transforming growth factor-β1 expressions were significantly upregulated in quercetin-treated rats, whereas tumor necrosis factor-α level was markedly reduced. Interleukin- 10 levels and CD31 stained vessels were markedly higher on day 3 and on day 7, respectively, in quercetin-treated rats. In H & E stained sections, quercetin-treated group showed less inflammatory cells, more fibroblast proliferation, increased microvessel density, better reepithelialization and more regular collagen deposition, as compared to control. The results suggest that topical application of quercetin promotes wound healing by effectively modulating the cytokines, growth factors and cells involved in inflammatory and proliferative phases of healing.

Microfluidic hydrothermal growth of ZnO nanowires over high aspect ratio microstructures

A hydrothermal synthesis of densely packed ZnO nanowires was realized in a confined space via forced circulation of the heated growth solution through microfluidic channels formed primarily by a set of high aspect ratio trenches in a Si substrate. A uniform and conformal seeding layer of ZnO was deposited to cover the entire surface of the trenches by means of atomic layer deposition (ALD). Densely packed ZnO nanowires were formed inside the trenches with particularly good coverage over the sidewalls, where they would not grow effectively through a conventional hydrothermal method. The strategy for controlled growth of densely packed ZnO nanowires over such high aspect ratio microstructures is deemed beneficial when these microstructures are employed as electrodes with high specific surface areas for devices such as supercapacitors or any other electrochemical devices.

Exogenous nitric oxide donor protects Artemisia annua from oxidative stress generated by boron and aluminium toxicity

Nitric oxide (NO) is an important signal molecule modulating the response of plants to environmental stress. Here we report the effects of boron (B) and aluminium (Al) contamination in soil, carried out with or without application of exogenous SNP (NO donor), on various plant processes in Artemisia annua, including changes in artemisinin content. The addition of B or Al to soil medium significantly reduced the yield and growth of plants and lowered the values of net photosynthetic rate, stomatal conductance, internal CO(2) concentration and total chlorophyll content. The follow-up treatment of NO donor favoured growth and improved the photosynthetic efficiency in stressed as well as non-stressed plants. Artemisinin content was enhanced by 24.6% and 43.8% at 1mmole of soil-applied B or Al. When SNP was applied at 2mmole concentration together with either 1mmole of B and/or Al, it further stimulated artemisinin biosynthesis compared to the control. Application of B+Al+SNP proved to be the best treatment combination for the artemisinin content in Artemisia annua leaves.

Constitutive expression of high-affinity sulfate transporter (HAST) gene in Indian mustard showed enhanced sulfur uptake and assimilation

Lycopersicon esculantum sulfate transporter gene (LeST 1.1) encodes a high-affinity sulfate transporter (HAST) located in root epidermis. In this study, the LeST 1.1 gene was constitutively expressed in Indian mustard (Brassica juncea cv. Pusa Jai Kisan). Transgenic as well as untransformed plants were grown in sulfur-insufficient (25 and 50 μM) and sulfur-sufficient (1,000 μM) conditions for 30 days. Two-fold increase was noticed in the sulfate uptake rate of transgenic plants grown in both sulfur-insufficient and -sufficient conditions as compared to untransformed plants. The transgenic B. juncea plants were able to accumulate higher biomass and showed improved sulfur status even in sulfur-insufficient conditions when compared with untransformed plants. Chlorophyll content, ATP sulfurylase activity and protein content were also higher in transgenic plants than untranformed plants under sulfur-insufficient conditions. Our results, thus, clearly indicate that constitutive expression of LeST 1.1 gene in B. juncea had led to enhanced capacity of sulfur uptake and assimilation even in sulfur-insufficient conditions. This approach can also be used in other crops to enhance their sulfate uptake and assimilation potential under S-insufficient conditions.

Microencapsulation: A promising technique for controlled drug delivery

MICROPARTICLES OFFER VARIOUS SIGNIFICANT ADVANTAGES AS DRUG DELIVERY SYSTEMS, INCLUDING: (i) an effective protection of the encapsulated active agent against (e.g. enzymatic) degradation, (ii) the possibility to accurately control the release rate of the incorporated drug over periods of hours to months, (iii) an easy administration (compared to alternative parenteral controlled release dosage forms, such as macro-sized implants), and (iv) Desired, pre-programmed drug release profiles can be provided which match the therapeutic needs of the patient. This article gives an overview on the general aspects and recent advances in drug-loaded microparticles to improve the efficiency of various medical treatments. An appropriately designed controlled release drug delivery system can be a foot ahead towards solving problems concerning to the targeting of drug to a specific organ or tissue, and controlling the rate of drug delivery to the target site. The development of oral controlled release systems has been a challenge to formulation scientist due to their inability to restrain and localize the system at targeted areas of gastrointestinal tract. Microparticulate drug delivery systems are an interesting and promising option when developing an oral controlled release system. The objective of this paper is to take a closer look at microparticles as drug delivery devices for increasing efficiency of drug delivery, improving the release profile and drug targeting. In order to appreciate the application possibilities of microcapsules in drug delivery, some fundamental aspects are briefly reviewed.

Common infectious agents prevalence in antiphospholipid syndrome

Antiphospholipid syndrome is characterized by thrombosis and pregnancy loss. Infections are generally associated with autoimmune diseases, but in the setting of antiphospholipid syndrome this link has been suggested as having a pathogenic role. In this study, 98 patients with antiphospholipid syndrome were screened for antibodies directed to several infectious agents. The main finding in this study is the significantly higher prevalence of IgM antibodies to toxoplasma and rubella. This novel finding suggests that these infections might be associated with antiphospholipid syndrome. As autoimmune diseases and, in particular, antiphospholipid syndrome are associated with infections, mainly the catastrophic type of the syndrome, this finding implies that a current infection with these agents, i.e. toxoplasma and rubella, might either be related to the pathogenesis of antiphospholipid syndrome or alternatively to its manifestations. Lupus (2009) 18, 1149—1153.

Neuropsychiatric lupus and infectious triggers

Infections can act as environmental triggers inducing or promoting systemic lupus erythematosus (SLE) in genetically predisposed individuals. The aim of the present study was to compare the titres of antibodies (Abs) to infectious agents with neuropsychiatric (NPSLE) clinical manifestations. The sera of 260 individuals (120 patients with SLE and 140 geographic controls) were evaluated for the titres of Epstein bar virus (EBV), cytomegalovirus (CMV), toxoplasma, rubella and syphilis Abs using the BioPlex 2200 Multiplexed Immunoassay method (BioRad) and by the ELISA method for Helicobacter pylori and Hepatitis B core Ag. All BioPlex 2200 kits used were in developmental stages. Data analysis was performed using SPSS 9.0 statistical analysis software (SPSS Inc., Chicago, IL, USA, 1999). Correlation analysis indicated that rubella IgM Ab titres were marginally, positively associated with psychosis ( P = 0.09). No other associations were detected between the 17 infectious Abs and five NP manifestations. When the positivity cut-off for anti-rubella IgM Abs was set at three standard deviations above normal, three positive subjects were identified: one patient with psychosis and one with depression, for a total NPSLE prevalence of 33.3%. On the contrary, the prevalence of NPSLE in the remaining subjects was 6.5%. Marginally significant correlations between elevated titres of rubella IgM Ab with psychosis and depression were found. Although this nearly 5-fold increase is not statistically significant, it appears that in a larger sample size, significance would be reached. This is the first study reported that examined the correlation of NPSLE manifestations with anti-infectious Abs.

Epstein Barr Virus and Cytomegalovirus in Autoimmune Diseases: Are They Truly Notorious? A Preliminary Report

To date, it is believed that the origin of autoimmune diseases is one of a multifactorial background. A genetic predisposition, an immune system malfunction or even backfire, hormonal regulation, and environmental factors all play important roles in the pathogenesis of autoimmune diseases. Among these environmental factors, the role of infection is known to be a major one. Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are considered to be notorious as they are consistently associated with multiple autoimmune diseases. A cohort of 1595 serum samples, of 23 different autoimmune disease groups, was screened for evidence of prior infection with EBV and CMV. All samples were screened for antibodies against EBV nuclear antigen-1 (IgG), EBV viral capsid antigen (IgG and IgM), EBV early antigen (IgG), EBV heterophile antibody, and CMV (IgG and IgM) antibodies using Bio-Rad's BioPlex 2200. A new association is proposed between EBV and polymyositis, as results show a significant increase in titers of various EBV target analytes when compared with healthy controls. Our results also support prior information suggesting the association between EBV and multiple autoimmune diseases, including SLE, antiphospholipid syndrome, rheumatoid arthritis, multiple sclerosis, pemphigus vulgaris, giant cell arthritis, Wegener's granulomatosis, and polyarteritis nodosa (PAN). Elevated CMV IgG titers were observed in sera of SLE patients. Our data support the theory that EBV is notoriously associated with many autoimmune diseases. CMV appears to be associated to autoimmune diseases as well, yet establishing this theory requires further investigation.

Oxidative stress and glucose levels in a population-based sample

OBJECTIVES

To examine the relationship between markers of oxidative status and glucose on a population basis.

STUDY DESIGN AND SETTING

We report here on a population-based sample of 1315 women and 981 men, aged 35-79 years, randomly selected from residents of Erie and Niagara Counties in western New York between 1996 and 1999. Thiobarbituric reactive substances (TBARS), erythrocyte glutathione (GSH) and plasma glutathione peroxidase (GSH-Px) were measured as markers of oxidative status. Study sample was categorized by quartiles of glucose, degree of abnormality of fasting glucose, and level of metabolic control in patients with diabetes.

RESULTS

Men and women in the uppermost quartiles of glucose had higher levels of TBARS (men: Quartile 4 = 1.55 +/- 0.03, Quartile 1 = 1.36 +/- 0.03, women: 1.49 +/- 0.02, 1.30 +/- 0.02 nmol/ml) and lower levels of GSH (men: Quartile 4 = 1.57 +/- 0.03, Quartile 1 = 1.69 +/- 0.03, women: 1.71 +/- 0.03, 1.97 +/- 0.0 mmol/l packed RBCs). In women, compared with normal fasting glucose, impaired fasting glucose was associated with higher levels of TBARS (1.29 +/- 0.01 vs. 1.84 +/- 0.04 nmol/ml), lower levels of GSH (1.85 +/- 0.02 vs. 1.76 +/- 0.05 mmol/l packed RBCs), and higher GSH-Px activity (618.94 +/- 2.64 vs. 644.77 +/- 8.90 IU/l). In women, abnormal fasting glucose was associated with higher levels of TBARS (1.84 +/- 0.04 nmol/ml), lower levels of GSH (1.68 +/- 0.06 mmol/l packed RBCs), and higher levels of GSH-Px (647.72 +/- 9.87 IU/l) than normal or impaired fasting glucose. In men, abnormal fasting glucose was associated with higher TBARS (1.76 +/- 0.04 vs. 1.37 +/- 0.07 nmol/ml), and lower GSH (1.62 +/- 0.05 vs. 2.78 +/- 0.02 mmol/l packed RBCs), than normal fasting glucose. Poor metabolic control was associated with higher TBARS (men: 2.07 +/- 0.08 vs. 1.33 +/- 0.14 nmol/l, women: 2.02 +/- 0.09 vs. 1.35 +/- 0.18 nmol/l) and GSH-Px activity (men: 654.34 +/- 13.45 vs. 599.86 +/- 24.76, women: 660.61 +/- 13.25 vs. 579.42 +/- 27.42 IU/l).

CONCLUSIONS

Glucose levels play a role in determining oxidative status in a population sample. The balance between oxidative and antioxidant processes appears to be sensitive to glucose levels with moderate elevations of glucose affecting the oxidative status.

Alcoholic beverage preference and characteristics of drinkers and nondrinkers in western New York (United States)

BACKGROUND AND AIM

Dietary and lifestyle characteristics may differ for drinkers of specific alcoholic beverages and nondrinkers which would have important implications for studies of alcohol and disease. Our aim in this study was to describe differences in dietary and lifestyle characteristics associated with alcoholic beverage preference in a population-based sample of healthy study participants.

METHODS AND RESULTS

Data were collected as part of a series of case-control studies of alcohol use, myocardial infarction, and lung, breast and prostate cancer in western New York from 1846 men and 1910 women aged 35 to 79, randomly selected from the general population of Erie and Niagara Counties. Beverage preference was defined for noncurrent vs current drinkers, and drinkers of beer, wine, liquor, and mixed beverages. Generalized linear models for continuous variables and Cochran-Mantel-Haenszel statistics for categorical variables were computed for the entire sample and stratified by gender. Participant characteristics differed by alcoholic beverage preference and drinking status. In general, wine drinkers had higher education and household incomes, lower prevalence of current smoking, higher intakes of dietary fiber, potassium, vitamin E, and total carotenoids, lower total fat intakes and higher amounts of fruits, vegetables, and grain products than consumers of other beverages. Conversely, beer and liquor drinkers had somewhat lower education and household incomes, higher rates of current smoking, higher energy and total fat intakes and consumed lower amounts of fruits, vegetables, and grain products. Finally, current nondrinkers were more likely to be older, less educated, have lower household incomes, and consume diets less consistent with dietary guidelines than current drinkers.

CONCLUSIONS

These results suggest that usual beverage preference may encompass other health-related behaviors and underline the importance of accurate exposure measurement and use of statistical methods to accommodate these interrelationships.

Correlates of markers of oxidative status in the general population

Oxidative stress has been implicated in the etiology of many chronic diseases, including cardiovascular disease. However, limited information exists on the factors that may influence oxidative status in the general population. In a random sample of the population of two counties in western New York, levels of several markers of oxidative status (i.e., thiobarbituric acid-reactive substances, erythrocyte glutathione, and glutathione peroxidase) were determined. A total of 894 men and 903 women aged 35-79 years were included in the study (1996-1999). In addition, a number of sociodemographic and lifestyle characteristics and cardiovascular disease risk factors were measured. Age, markers of glucose metabolism (e.g., plasma glucose level) and insulin resistance (e.g., serum triglycerides, high density lipoprotein cholesterol, body mass index), and postmenopausal status in women were associated with increased oxidative stress and reduced antioxidant potentials. Oxidative status and antioxidant potentials appear to be significantly associated with a number of major cardiovascular disease risk factors; most of them are linked to abnormalities in glucose and insulin metabolism.

Reconstitution of the B800 bacteriochlorophylls in the peripheral light harvesting complex B800-850 of rhodobacter sphaeroides 2.4.1 with BChl a and modified (bacterio-)chlorophylls

A method is described for reversibly removing bacteriochlorophyll from the B800-site of the B850-850 antenna complex from Rhodobacter sphaeroides. This method uses the oligosaccharidic detergent Triton BG-10, together with an incubation at pH 5.0. Reconstitution at the B800-site has been successfully achieved for a range of modified bacteriochlorophylls. Copyright 1998 Elsevier Science B.V. All rights reserved.

Effect of plant density on the yields of artemisinin and essential oil in Artemisia annua cropped under low input cost management in North-Central India

A field experiment was conducted on Artemisia annua L. during the winter-summer season of 1995-96 at Lucknow, located at 26.5 degrees N, 80.5 degrees E and 120 m above mean sea level, representing a semiarid-subtropical climate with hot summer and fairly cool winters to study the effect of varying plant densities on the yields of essential oil and artemisinin under the conditions of no interculture and fertilizer applications. Results showed that A. annua at the population density of 2.22 x 10(5) plants ha(-1) yielded 7.4 kg of artemisinin and 91 kg of essential oil. It was also observed that at the same oil yield level, the yield of artemisinin increased by 1.5-, 2-, and 2.5-fold when the plant densities increased by about 2-, 4-, and 8-fold. Correspondingly, the suppression of weeds occurred by about 33, 133, and 333%, respectively. The plant architecture and canopy structure produced in high density A. annua plots presumably favoured the synthesis and accumulation of artemisinin resulting in artemisinin-rich, mature plants. It is recommended that, under subtropical agroclimatic conditions of north Indian plains, the A. annua should be cultivated at very high plant densities such as 2.22 x 10(5) plants ha(-1) forgetting high artemisinin yields.

Zinc supplementation affects the activity patterns of rural Guatemalan infants

Zinc deficiency has been associated with growth deficits, reduced dietary intake and appetite, and has been hypothesized to result in reduced activity. This randomized, double-blind, placebo-controlled study examined whether 10 mg of oral zinc as zinc sulfate, given daily for up to 7 mo, affected activity patterns of 85 Guatemalan infants recruited at 6-9 mo of age. Infant activity was assessed by time sampling-observation method at 10-min intervals during a 12-h data collection period, at base line, 3 and 7 mo follow-up. Motor development and the percentage of time infants were observed in various positions (being carried, lying down, sitting, crawling, standing or walking) and engaged in various activities (eating, sleeping, resting, crying/whining or playing) were compared by treatment group. No differences in motor development were observed by treatment group. However, at follow-up 2 (after 7 mo of supplementation), zinc-supplemented infants were significantly more frequently observed sitting up compared with lying down, and were playing during 4.18 +/- 1.95% (P < 0.05) more observations than unsupplemented infants. They were also somewhat less likely to be observed crying or whining (P < 0.10) compared with those receiving the placebo. These effects are independent of other factors including infant age, motor development, sex, maternal education, family socioeconomic status and nutritional status at base line. Further research must be conducted to determine the long-term developmental importance of these differences in activity patterns associated with zinc supplementation in this setting.

The Accumulation Record from the GISP2 Core as an Indicator of Climate Change Throughout the Holocene

A depth-age scale and an accumulation history for the Holocene have been established on the Greenland Ice Sheet Project 2 (GISP2) deep core, providing the most continuously dated record of annual layer accumulation currently available. The depth-age scale was obtained with the use of various independent techniques to count annual layers in the core. An annual record of surface accumulation during the Holocene was obtained by correcting the observed layer thicknesses for flow-thinning. Fluctuations in accumulation provide a continuous and detailed record of climate variability over central Greenland during the Holocene. Climate events, including "Little Ice Age" type events, are examined.

Changes in Atmospheric Circulation and Ocean Ice Cover over the North Atlantic During the Last 41,000 Years

High-resolution, continuous multivariate chemical records from a central Greenland ice core provide a sensitive measure of climate change and chemical composition of the atmosphere over the last 41,000 years. These chemical series reveal a record of change in the relative size and intensity of the circulation system that transported air masses to Greenland [defined here as the polar circulation index (PCI)] and in the extent of ocean ice cover. Massive iceberg discharge events previously defined from the marine record are correlated with notable expansions of ocean ice cover and increases in PCI. During stadials without discharge events, ocean ice cover appears to reach some common maximum level. The massive aerosol loadings and dramatic variations in ocean ice cover documented in ice cores should be included in climate modeling.

Pleuroscopy in the diagnosis of pleural effusion using a fiberoptic bronchoscope

Forty patients with undiagnosed pleural effusions were investigated by pleuroscopy, using a fiberoptic bronchoscope. Pleural biopsies diagnostic of tuberculosis were obtained in 17 cases, and in 12 of these tubercle bacilli were cultured from the pleural fluid. Pleural biopsy at thoracoscopy is superior to the percutaneous intercostal route and for this purpose the fiberoptic bronchoscope is preferable to the rigid thoracoscope.

Skin penetration of minerals in psoriatics and guinea-pigs bathing in hypertonic salt solutions

Penetration of electrolytes through the human skin was measured in healthy volunteers and in psoriatic patients after bathing in the Dead-Sea or in simulated bath-salt solutions. Significant increases in the levels of serum Br, Rb, Ca and Zn were noticed only in the psoriatic patients after daily bathing in the Dead-Sea for a 4-week regimen. Guinea-pigs "bathed" in simulated Dead-Sea bath-salt solutions containing radionuclides of Ca, Mg, K and Br. Traces of each radionuclide were detected in the blood and in some internal organs after 60 minutes of bathing. The radionuclides showed a physiological pattern in their organ distribution. Even though the whole investigation was carried out in hypertonic solutions, there is a definite penetration of salts through healthy (human and guinea-pigs) and damaged (psoriatic) epidermis. This finding suggests that improvement of the psoriatic condition after bathing in the Dead-Sea, may be partly attributed (in addition to ultraviolet irradiation) to the minerals' effect on the psoriatic skin.

Massive rectal bleeding of colonic origin: localization of the bleeding site

Fourteen patients with massive colonic bleeding underwent preoperative evaluation including visceral angiography and/or colonoscopy. Segmental for subtotal colectomy was performed in each case. The freshly excised colonic specimen was opened and washed clean, and the mucosal surface was closely examined by manually compressing the specimen segment by segment in order to detect the minute bleeding site(s), which were then marked with a suture for histologic sectioning. This maneuver was successful in 13 instances. In 11 of these, histologic identification was made; seven were cases of vascular malformations, and four were cases of diverticular bleeding. In 5 of these 11 cases, colonoscopy and/or visceral angiography failed to localize the bleeding sites; four were cases of bleeding of diverticular origin. Of the two patients in whom histologic identification was not made despite suture identification, one underwent a second colonic resection in which bleeding sites were histologically identified; the bleeding was not caused by vascular malformations or diverticula. The method of examining the freshly excised specimen described is useful for accurate histologic identification of the cause of colonic bleeding, particularly for diverticular bleeding. The method is also useful for immediate assessment of adequacy and appropriateness of surgical resection.

Serum bromine levels in psoriasis

Serum bromine levels in psoriatic Danes increased 2- to 3-fold during a 4-week bathing course in the Dead Sea. This increase correlated well with the improvement in their clinical and psychic condition. Serum bromine levels in psoriatic Danes were somewhat lower than those in healthy subjects residing in Denmark, but the difference was not significant. Israelis working in the open air in the Dead Sea area (air bromine 20-fold higher than in Jerusalem) had higher bromine levels than psoriatic or healthy Israelis residing in Jerusalem or healthy Israelis working in air-conditioned rooms in the Dead Sea area (p less than 0.05), but those levels were still within the normal range. As our animal experimentation indicates that the skin is a major target organ for 82Br, applied either by bathing or as an aerosol, we conclude that the higher bromine levels noticed in the psoriatic Danes after their 4-week stay at the Dead Sea may be equally due to their contact with the bromine-containing aerosol and the high bromine level of the Dead Sea waters.

Antistriated muscle-antibodies during clinical dysreflexia: case report

The object of the following study is the research of an immunological mechanism related to the clinical dysreflexia found in tetraplegic patients. Dysreflexia is known to be associated with automatic mechanisms during bladder distention in patients with lesions about T5.

A new method in differential diagnosis of the liver: identification of liver pulsating activities by spectral analysis of radio-isotope counts during liver scan. Comparative studies by ultrasonography

Liver scanning with 99mCi 99Tc sulphur-colloid was practiced in 50 patients: 30 suffering from malignant tumors, 10 from hepatic cirrhosis and 10 from pyrexia of unknown origin. Liver radioactivity was recorded by a gamma-camera connected to a computer, 1 frame each 10 seconds for 15 minutes. The spectral analysis of the radioactivity counts taken in different region of interest, showed evidence of a periodic fluctuation, with a period value around 1 minute. Comparative ultrasonographic dynamic study showed evidence of the same phenomena in 16 examined patients. The period of pulsation was found different in each of the following groups: normal liver, cirrhotic, metastatic and infectious diseases.

Kidney and bladder pulsating activities during radioisotope renogram by computer data analysis

This is a report of a new method in which the mathematical study of radioactivity changes in the bladder and kidney shows evidence of pulsating and vibratory activities. This study was done during radioisotope renogram with 99mTc DTPA. Spectral analysis of the recorded activities, taken 50 frames/sec and 1 frame every 10 sec by a scintillation camera connected to a computer, shows evidence of pulsating and vibratory activities of the kidney and the bladder. Slow pulsations with a period from 1/2 to 2 1/2 min were identified. Infrasonoric vibrations, from 2 to 25 Hz were found in the kidney, in a full bladder and during micturition.