Root uptake and shoot accumulation of cadmium by lettuce at various Cd:Zn ratios in nutrient solution.

Cadmium (Cd) is toxic to animals and humans after it accumulates over decades in the kidney cortex. Food crops grown in Cd-contaminated soils are the primary sources of excessive Cd entry into humans. Although plant available Zn concentration in soil is an important factor which can greatly reduce Cd uptake by plant roots and its translocation into the edible parts, Cd:Zn ratio is suggested to be a more important factor in comparison with Zn concentration alone in determining Cd uptake by plants. In the present study, the physiological mechanisms of Cd absorption by roots and its translocation to leaves of lettuce (Lactuca sativa L.) at various Cd:Zn ratios in the rooting media were investigated. For this purpose, seedlings of hydroponically-grown lettuce were exposed to combinations of four Zn (0, 12.5, 50 and 100µM) and four Cd (0, 0.5, 1 and 10µM) concentrations providing different ratios of Cd:Zn. At each level of Cd, decreasing the Cd:Zn ratio by increasing Zn concentration in the nutrient solution caused significant reduction of root symplastic Cd and also reduced Cd loading into the xylem and Cd transport to and accumulation in leaves. The highest root symplastic Cd (1087mg/kg-1 Dry Weight [DW]) and shoot Cd concentrations (64mg/kg-1 DW) were observed at the highest Cd:Zn ratio of = 0.8 (Zn = 12.5, Cd = 10). At the Cd:Zn ratios of ≤ 0.01, shoot Cd concentration was less than the Detection Limit (< 0.02mg/kg DW). Decreasing Cd:Zn ratio in nutrient solution was accompanied with significant increase in root apoplastic Cd and decrease in the root symplastic Cd. According to the obtained results, at the Cd:Zn ratio equal to 0.01 and less, Cd concentration in lettuce shoots decreased to < 0.02mg/kg.

Witches'-Broom Disease of Lime Affects Seed Germination and Seedling Growth But Is Not Seed Transmissible.

Witches'-broom disease of lime (WBDL), caused by 'Candidatus Phytoplasma aurantifolia', has devastated many Mexican lime orchards and is currently a threat to lime production in neighboring provinces of southern Iran. Several reports have suggested transmission and spread of WBDL phytoplasma through the seed of infected plants. In the present study, claims of seed transmission of this phytoplasma were examined. Fruit were collected from infected trees in the infested areas of Minab (Hormozgan Province) and from symptomless trees in noninfested areas. Lime seed from symptomless and witches'-broom-affected trees were sown in separate beds in an insect-proof screenhouse and the resulting seedlings were examined for phytoplasmal infection. Leaf, stem, and root samples were collected from both groups of seedlings every 3 months for 2 years and tested for WBDL phytoplasma using direct and nested polymerase chain reaction (PCR). Repeated PCR tests on the seedlings did not reveal the presence of phytoplasmal DNA. Likewise, symptoms of the disease were not observed on these seedlings after 2 years. PCR assays detected the phytoplasma in coats of some seed from infected trees; however, no excised embryos were positive for the phytoplasma. All positive PCR results were confirmed by restriction fragment length polymorphism assay. One-year-old seedlings derived from seed of noninfected plants appeared more vigorous in terms of height, number of leaves, and fresh weight of shoot compared with those from infected trees. The germination percentage, mean daily germination, peak value, and germination value were significantly higher for seed of fruit from noninfected trees and seed from fruit on asymptomatic branches of infected trees than those from fruit on symptomatic branches of infected trees.

Tumour-necrosis factor-A polymorphisms and gastric cancer risk: a meta-analysis.

Inflammation is one of the early phases in the development of gastric cancer. Therefore, several studies have examined the association of polymorphisms in tumour-necrosis factor-A gene (TNF-A) with gastric cancer risk. This meta-analysis reviews and summarises published evidence for these associations. Searching several databases yielded 24 independent studies that reported on the associations between TNF-A polymorphisms and gastric cancer risk. We analysed available data for the most commonly investigated polymorphisms: TNF-A -308G>A (23 studies), TNF-A -238G>A (9 studies), and TNF-A -857C>T (5 studies). Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in the random-effects model using the DerSimonian-Laird method. Q-statistic and I(2)-statistic were calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects. The overall ORs (95% CIs) for AG and AA genotypes vs GG genotype for TNF-A -308 were 1.09 (0.94-1.27) and 1.49 (1.11-1.99), respectively. For TNF-A -238, the corresponding ORs (95% CIs) were 1.05 (0.84-1.33) and 1.25 (0.30-5.26), respectively. The overall ORs (95% CIs) for CT and TT genotypes (vs CC) for TNF-A -857 were 1.06 (0.89-1.27) and 1.57 (0.91-2.70), respectively. The statistically significant association between TNF-A -308GG and gastric cancer was limited to western populations. This association showed little heterogeneity (I(2)=0) and remained consistently strong when analyses were limited to anatomic and histologic subtypes of gastric cancer, or limited to studies in which genotype frequencies were in Hardy-Weinberg equilibrium, or limited to larger studies. These same subgroup analyses did not change results associated with other polymorphisms. In conclusion, TNF-A -308AA genotype was associated with a statistically significant increased risk of gastric cancer, whereas other studied polymorphisms were not. The association between TNF-A -857TT genotype and gastric cancer was near significant, and may become significant if more studies are published.

Equilibrium and kinetic adsorption study of a cationic dye by a natural adsorbent--silkworm pupa.

In this work the use of silkworm pupa, which is the waste of silk spinning industries has been investigated as an adsorbent for the removal of C.I. Basic Blue 41. The amino acid nature of the pupa provided a reasonable capability for dye removal. Equilibrium adsorption isotherms and kinetics were investigated. The adsorption equilibrium data were analyzed by using various adsorption isotherm models and the results have shown that adsorption behavior of the dye could be described reasonably well by either Langmuir or Freundlich models. The characteristic parameters for each isotherm have been determined. The monolayer adsorption capacity was determined to be 555 mg/g. Kinetic studies indicated that the adsorption follows pseudo-second-order kinetics with a rate constant of 0.0434 and 0.0572 g/min mg for initial dye concentration of 200 mg/l at 20 and 40 degrees C, respectively. Kinetic studies showed that film diffusion and intra-particle diffusion were simultaneously operating during the adsorption process. The rate constant for intra-particle diffusion was estimated to be 1.985 mg/g min(0.5).

Calorimetric and binding dissections of HSA upon interaction with bilirubin.

The interactions between bilirubin and human serum albumin (HSA) were studied by isothermal titration calorimetry (ITC) and UV-vis spectrophotometry at 27 degrees C in 100 mM phosphate buffer pH 7.4 containing 1 mM EDTA. The biphasic shape of the HSA-bilirubin binding curve depicted the existence of two bilirubin binding sets on the HSA structure which had distinct binding interactions. Each binding set contained one or more bilirubin binding site. The first binding set at subdomain IIA included one binding site and had a more hydrophobic microenvironment than the other two binding sites in the second bilirubin binding set (subdomain IIIA). With our method of analysis, the calculated dissociation constant of the first binding site is 1.28 x 10(-6) M and 4.80 x 10(-4) M for the second and third binding sites. Here, the typical Boltzmann's equation was used with a new approach to calculate the dissociation constants as well as the standard free energy changes for the HSA-bilirubin interactions. Interestingly, our calculations obtained using the Wyman binding potential theory confirmed that our analysis method had been correct (especially for the second binding phase). The molar extinction coefficient determined for the first bound bilirubin molecule depicted that the bilirubin molecules (in low concentrations) should interact with the nonpolar microenvironment of the first high affinity binding site. Binding of the bilirubin molecules to the first binding site was endothermic (deltaH > 0) and occurred through the large increase in the binding entropy established when the hydrophobic bilirubin molecules escaped from their surrounding polar water molecules and into the hydrophobic medium of the first binding site. On the other hand, the calculated molar extinction coefficient illustrated that the microenvironment of the second binding set (especially for the third binding site) was less hydrophobic than the first one but still more hydrophobic than the buffer medium. The binding of the third bilirubin molecule to the HSA molecule was established more through exothermic (electrostatic) interactions.

A short-impulse UWB BPSK transmitter for large-scale neural recording implants.

In this paper, a short-impulse ultra-wide band (UWB) transmitter is introduced to enable large-scale neural recordings within miniature brain implants including thousands of channels. The proposed impulse radio UWB transmitter uses a BPSK modulation scheme, the carrier signal of which uses only two delayed impulses to encode the transmitted signal. The proposed UWB transmitter has been implemented into a CMOS 180 nm technology. It occupies 300 µm × 230 µm, and consumes only 6.7 pJ/bit from a 1.8-V supply. Experimental results show that the transmitter has a bandwidth of 2.6 GHz to 5.6 GHz and achieves a maximum data rate of 800 Mbps, which outperforms existing low-power UWB transmitters for similar applications.

Corona discharge ionization of paracetamol molecule: peak assignment.

Ionization of paracetamol was investigated using ion mobility spectrometry equipped with a corona discharge ionization source. The measurements were performed in the positive ion mode and three peaks were observed in the ion mobility spectrum. Experimental evidence and theoretical calculations were used to correlate the peaks to related ionic species of paracetamol. Two peaks were attributed to protonated isomers of paracetamol and the other peak was attributed to paracetamol fragment ions formed by dissociation of the N-C bond after protonation of the nitrogen atom. It was observed that three sites of paracetamol compete for protonation and their relative intensities, depending on the sample concentration. The ratio of ion products could be predicted from the internal proton affinity of the protonation sites at each concentration.

Changes in N-terminal pro-B-type natriuretic peptide and incidence of diabetes: The Multi-Ethnic Study of Atherosclerosis (MESA).

AIMS: This study looked at whether the inverse association of circulating N-terminal pro-B-type natriuretic peptide (NT-proBNP) with incident diabetes is modified by changes in NT-proBNP (ΔNT-proBNP) levels. METHODS: Plasma NT-proBNP was assayed at baseline and 3.2 years later (visit 3) in the Multi-Ethnic Study of Atherosclerosis (MESA). ΔNT-proBNP was calculated as NT-proBNP visit3-NT-proBNP baseline. A Poisson distribution was fitted to determine the incidence density of diabetes, adjusted for age, race, gender, educational attainment, antihypertensive medication, total intentional exercise and plasma IL-6 levels. In the primary analysis (n=3236 without diabetes up to visit 3, followed for a mean of 6.3 years), incidence density was regressed for the following categories of baseline NT-proBNP: (1)<54.4 pg/mL; (2) 54.4-85.9 pg/mL; and (3) 86-54.2 pg/mL. This was crossed with categories of ΔNT-proBNP as medians (ranges): (1) -6.2 (-131-11.7) pg/mL; (2) 19.8 (11.8-30.1) pg/mL; (3) 44.0 (30.2-67.9) pg/mL; and (4) 111.2 (68.0-3749.9) pg/mL. RESULTS: The incidence density of diabetes followed a U-shaped association across categories of ΔNT-proBNP within categories of baseline NT-proBNP after adjusting for other covariates (P=0.02). At each level of baseline NT-proBNP, the incidence density of diabetes was lowest for small-to-moderate increases in NT-proBNP. CONCLUSION: This analysis suggests that NT-proBNP has a biphasic association with diabetes in which the risk of incident diabetes decreases within a 'physiological range' of ΔNT-proBNP, and plateaus or increases as NT-proBNP concentrations increase, probably in response to pathophysiological conditions leading to high levels of NT-proBNP.

Serological Study on Cytomegalovirus and Toxoplasma Gondii in Thalassemia Major Patients of Yazd, Iran.

BACKGROUND: Beta-thalassemia patients receive blood products from blood transfusion centers repeatedly. Blood transfusion can transmit Cytomegalovirus (CMV) and Toxoplasma gondii. The aim of this study was serological evaluation of these two infectious agents in thalassemia patients. MATERIALS AND METHODS: In a cross-sectional study, the enzyme-linked immunosorbent assay (ELISA) testing was performed to detect IgM and IgG antibodies against CMV and Toxoplasma gondii in 96 thalassemia patients (under 18 years) and 144 healthy people. Data were analyzed by SPSS software and Chi-square test. RESULTS: A significant difference was observed in CMVIgM antibody levels between test groups in women (p<0.05). The prevalence of CMV IgM, CMV IgG, Toxo-IgG, and Toxo IgM antibodies in thalassemia patients were 5.2%, 95.9%, 16%, and 0%, respectively. CONCLUSION: In all thalassemia patients, Cytomegalovirus IgG is higher than healthy people. In addition, CMV IgM antibodies are higher in female patients. Antibody screening (IgM) on blood products for detecting Cytomegalovirus is necessary, but for Toxoplasma gondii is not necessary in the Yazd transfusion center.

BER performance of implant-to-air high-speed UWB data communications for neural recording systems.

Implant-to-air ultra-wideband communication systems are interesting for neural recording systems due to their low power consumption and high data-rates. In this paper we investigate the performance of an implant-to-air wireless link using a realistic model of the biological channel for neural recording systems. We propose an optimized fifth-derivative Gaussian pulse as a transmitted waveform for different modulations: binary phase shift keying (BPSK), on-off keying (OOK) and differential phase shift keying (DPSK). Monitoring of neural responses with high resolution in the brain requires a high data rate link as the number of electrodes is increased. Each electrode needs a data rate around 800 kb/s to support its neural channel. As we target more than 512 electrodes, we require a data link higher than 400 Mbps.

Flexible sixteen monopole antenna array for microwave breast cancer detection.

Radar based microwave imaging (MI) has been widely studied for breast cancer detection in recent times. Sensing dielectric property differences of tissues over a wide frequency band has been made possible by ultra-wideband (UWB) techniques. In this paper, a flexible, compact monopole antenna on a 100 µm Kapton polyimide is designed, using a high frequency structure simulator (HFSS), to be in contact with biological breast tissues over the 2-5GHz frequency range. The antenna parameters are optimized to obtain a good impedance match over the required frequency range. The designed antenna size is 18mm × 18mm. Further, a flexible conformal 4×4 ultra-wideband antenna array, in a format similar to that of a bra, was developed for a radar-based breast cancer detection system.

Association of endothelial and oxidative stress with metabolic syndrome and subclinical atherosclerosis: multi-ethnic study of atherosclerosis.

BACKGROUND/OBJECTIVES: A cluster of metabolic abnormalities termed metabolic syndrome (MetS) is associated with vascular endothelial dysfunction and oxidative internal milieu. We examined whether the association of MetS with subclinical atherosclerosis is explained by biomarkers of endothelial damage and oxidative stress. SUBJECTS/METHODS: Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based study of 45- to 84-year-old individuals of four US ethnicities without clinical cardiovascular disease. A random sample of 997 MESA participants had data on the following biomarkers: von Willebrand factor, soluble intercellular adhesion molecule-1 (sICAM-1), CD40 ligand (CD40L), soluble thrombomodulin, E-selectin and oxidized LDL (oxLDL). We examined whether the associations of MetS with B-mode ultrasound-defined common and internal carotid intimal-medial thickness (IMT) and coronary artery calcium (CAC) measured using computerized tomography were explained by the biomarkers using multiple regression methods. RESULTS: MetS was associated with higher levels of each of the biomarkers (P<0.001, CD40L-suggestive association P=0.004), with greater IMT (P<0.001), and with greater extent of CAC in those in whom CAC was detectable (P=0.01). The association of MetS with measures of subclinical atherosclerosis remained unchanged after adjustment for the biomarkers. After adjusting for MetS, oxLDL was suggestively associated with greater prevalence of detectable CAC (P=0.005) and thicker internal carotid IMT (P=0.002), whereas sICAM-1 was significantly associated with greater prevalence of detectable CAC (P=0.001). CONCLUSIONS: The association of MetS with subclinical atherosclerosis was independent of its association with biomarkers of endothelial damage and oxidative stress, suggesting that metabolic abnormalities and oxidative endothelial damage may lead to atherosclerotic disease through distinct mechanisms.