Comparison of organic and inorganic amendments for enhancing soil lead phytoextraction by wheat (Triticum aestivum L.)

Phytoextraction has received increasing attention as a promising, cost-effective alternative to conventional engineering-based remediation methods for metal contaminated soils. In order to enhance the phytoremediative ability of green plants chelating agents are commonly used. Our study aims to evaluate whether, citric acid (CA) or elemental sulfur (S) should be used as an alternative to the ethylene diamine tetraacetic acid (EDTA)for chemically enhanced phytoextraction. Results showed that EDTA was more efficient than CA and S in solubilizing lead (Pb) from the soil. The application of EDTA and S increased the shoot biomass of wheat. However, application of CA at higher rates (30 mmol kg(-1)) resulted in significantly lower wheat biomass. Photosynthesis and transpiration rates increased with EDTA and S application, whereas these parameters were decreased with the application of CA. Elemental sulfur was ineffective for enhancing the concentration of Pb in wheat shoots. Although CA did not increase the Pb solubility measured at the end of experiment, however, it was more effective than EDTA in enhancing the concentration of Pb in the shoots of Triticum aestivum L. It was assumed that increase in Mn concentration to toxic levels in soil with CA addition might have resulted in unusual Pb concentration in wheat plants. The results of the present study suggest that under the conditions used in this experiment, CA at the highest dose was the best amendment for enhanced phytoextraction of Pb using wheat compared to either EDTA or S.

Polymorphisms in the vitamin D receptor and the androgen receptor gene associated with the risk of urolithiasis

Transcriptional activity of the vitamin D receptor (VDR) gene is regulated by androgen receptor (AR) gene and both are associated with renal stone formation. We examined gene polymorphisms of VDR (PCR-RFLP) and AR (GeneScan analysis) in 125 stone formers and 150 controls from north India. Genotype Ff of Fok-I and Tt of Taq-I demonstrated significantly higher risk (P<0.001, OR=3.559 and P=0.019, 1.830 respectively). Variant f allele exhibited 1.7-folds higher risk. Ff of Fok-I and Aa of Apa-I gene polymorphism showed higher risk in males only. Mean CAG repeat was significantly higher in hypercalciuric patients as compared to normocalciuric (mean=21.62 ± 3.384 vs. 20.11 ± 3.182; P=0.034). Combined effects 1.8-folds higher risk in patients with Tt genotype of Taq-I and short CAG repeat. Thus, association of FokI and TaqI VDR gene polymorphisms suggest VDR as an important genetic marker for urolithiasis. Further, patients with combination of Tt of Taq-I and short CAG repeat were at higher risk for stone formation.

Amyand's hernia in infant: a rare entity

The chance of vermiform appendix lying with in a hernial sac is 1% or less and is known as Amyand's hernia and it is very rare in infant and neonate. Till date, only twenty cases had been reported in English literature. We are reporting a rare case of Amyand's hernia where appendix was present in right inguinal sac of non-obstructed inguinal hernia in a seven month old male infant during operation. The appendectomy was done along with right inguinal herniotomy. In most of the reported cases, appendix was inflamed or perforated, expect in one case where appendix was not inflamed but patient presented with inguinal hernia. This case is reported because of the rarity of Amyand's hernia in infant, the appendix was not inflamed, hernia was not obstructed, and whether in such types of cases appendix should be preserved or not.

On the growth and microstructure of carbon nanotubes grown by thermal chemical vapor deposition

Carbon nanotubes (CNTs) were deposited on various substrates namely untreated silicon and quartz, Fe-deposited silicon and quartz, HF-treated silicon, silicon nitride-deposited silicon, copper foil, and stainless steel mesh using thermal chemical vapor deposition technique. The optimum parameters for the growth and the microstructure of the synthesized CNTs on these substrates are described. The results show that the growth of CNTs is strongly influenced by the substrate used. Vertically aligned multi-walled CNTs were found on quartz, Fe-deposited silicon and quartz, untreated silicon, and on silicon nitride-deposited silicon substrates. On the other hand, spaghetti-type growth was observed on stainless steel mesh, and no CNT growth was observed on HF-treated silicon and copper. Silicon nitride-deposited silicon substrate proved to be a promising substrate for long vertically aligned CNTs of length 110-130 μm. We present a possible growth mechanism for vertically aligned and spaghetti-type growth of CNTs based on these results.

Biosorption of lead using immobilized Aeromonas hydrophila biomass in up flow column system: factorial design for process optimization

Free and immobilized biomass of Aeromonas hydrophila has been utilized for the removal of Pb(II) from aqueous solution. Fitness of Langmuir sorption model to the sorption data indicated the sorption was monolayer and uptake capacity of biomass was 163.9 and 138.88 mg/g for the free and immobilized biomass respectively. 85.38% Pb(II) removal was achieved at bed height of 19 cm and flow rate of 2 mL/min and BDST model was in a good agreement with the experimental results (r(2)>0.997). An attempt has been made to optimize the process conditions for the maximum removal using Central Composite Design with the help of Minitab 15 software and the result predicted by optimization plots was 88.27% which is close to the experimental data i.e. 85.38%. Sorption-desorption studies revealed that polysulfone immobilized biomass could reused up to 16 cycles and bed was completely exhaust after 33 cycles.

Electrical characteristics of PbSe nanoparticle/Si heterojunctions

I-V characteristics of PbSe nanoparticle/single crystal Si heterojunctions prepared by chemical bath deposition method show a rectifying behavior. With decrease in average PbSe grain size between 72 nm and 9 nm currents decrease for forward and reverse bias. C-V characteristics indicate that the junctions transform into that of a metal insulator semiconductor (MIS) as the PbSe nanoparticle size decreases from 72 nm to 9 nm. This insulator like behavior of the small PbSe nanoparticle films is attributed to the highly resistive grain boundaries. Cole-Cole plots demonstrate that on decrease of grain size, the grain boundary contribution increases and grain contribution to the overall impedance decreases. Frequency dependence of capacitance proves space charge polarization in larger grains, which recedes with decrease in average grain size proving insulator like behavior of small PbSe nanoparticles.

Biosorption of Pb(II) from water using biomass of Aeromonas hydrophila: central composite design for optimization of process variables

Biomass of Aeromonas hydrophila was successfully utilized for the removal of lead from aqueous solution. The effect of process variables such as pH, initial Pb(II) concentration, biomass dose and temperature on the uptake of lead were investigated using two level four factor (2(4)) full factorial central composite design with the help of MINITAB version 15 software. The predicted results thus obtained were found to be in good agreement (R(2)=98.6%) with the results obtained by performing experiments. The multiple regression analysis and analysis of variance (ANOVA) showed that the concentration has positive and temperature and biomass dose have negative whereas pH has curved relationship with the uptake of Pb(II). The maximum uptake of Pb(II) predicted by optimization plots was 122.18 mg/g at 20 degrees C, initial Pb(II) concentration of 259 mg/L, pH 5.0, temperature 20 degrees C and biomass dose 1.0 g. Langmuir isotherm model was applicable to sorption data and sorption capacity was found to be 163.3mg/g at 30 degrees C, pH 5.0 and Pb(II) concentration range 51.8-259 mg/L indicate that the biosorbent was better in comparison of the biosorbent reported in the literature. Dubinin-Radushkevich (D-R) isotherm model was also applied and it was found that sorption was chemisorption (E=12.98 kJ/mol). FT-IR studies indicate the involvement of various functional groups present on biomass surface in the sorption of Pb(II).

An unusual presentation of hydatid cyst in anterior abdominal wall

Hydatid disease is a parasitic infestation caused by the larval form of the cestode worm Echinococcus. The most commonly encountered form of the disease is visceral hydatid cyst caused by Echinococcus granulosus or dog tapeworm. Muscular involvement has been reported in only 3-4% cases. We are reporting this case because of its rarity, difficulty to diagnose clinically, dramatic response to medical treatment and to alert the reader of this rare infestation so that open biopsy will be avoided.

Survival update from a multicenter, randomized, phase III trial of vitespen versus observation as adjuvant therapy for renal cell carcinoma in patients at high risk of recurrence

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Background: Vitespen (formerly HSPPC-96) is a novel, autologous, heat shock protein (gp96)-peptide complex vaccine. The survival registry is investigating long-term efficacy of vitespen in renal cell carcinoma (RCC) patients at high risk for recurrence postnephrectomy. Methods: Eligible patients were enrolled and active in Antigenics’ C-100–12 phase III protocol, with a last survival status of alive at study end. Patients randomized in C-100–12 (1:1, vitespen vs. observation) had AJCC stage I (T1b), II (≥5 cm; Fuhrman grade 3/4), stage III, or stage IV (M0) RCC, ≥25% clear cells, ECOG performance score 0/1 and ≥7 g viable tumor tissue for vaccine production. The registry's primary objective is to assess OS. Registry patients are contacted every 6 (no recurrence) or 3 (upon recurrence) m, for a total of 3 y from final C-100–12 data cutoff. Results: Upon C-100–12 termination, 513 of 728 patients were eligible for follow-up. Currently, 306/513 (60%) patients are in the registry database; 207 patients are being contacted. The cohort of 306 patients is well balanced by C-100–12 randomization arm: (59.8% vitespen, 59.5% observation). Formal statistical analyses are in process. Descriptively, updated OS data show a favorable trend in the vitespen arm vs. observation in all analysis sets, especially among patients with earlier-stage disease (stage I/II high grade; n = 118) or at intermediate risk for recurrence (stage I/II high grade, III T1, T2, T3a, low grade; n = 184 ), with 13/125 (10.4%) vs. 21/115 (18.3%), and 18/184 (9.8%) vs. 33/178 (18.5%) deaths reported in the vitespen and observation arms, respectively. Conclusions: The registry provides an opportunity to confirm whether the emerging survival advantage demonstrated at the data cutoff for the C-100–12 trial improves with prolonged follow-up. Formal statistical analyses are ongoing; data available to date show continuing signals of clinical benefit associated with vitespen treatment in patients with better prognostic factors.

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Structural Modification in Carbon Nanotubes by Boron Incorporation

We have synthesized boron-incorporated carbon nanotubes (CNTs) by decomposition of ferrocene and xylene in a thermal chemical vapor deposition set up using boric acid as the boron source. Scanning and transmission electron microscopy studies of the synthesized CNT samples showed that there was deterioration in crystallinity and improvement in alignment of the CNTs as the boron content in precursor solution increased from 0% to 15%. Raman analysis of these samples showed a shift of ~7 cm(-1) in wave number to higher side and broadening of the G band with increasing boron concentration along with an increase in intensity of the G band. Furthermore, there was an increase in the intensity of the D band along with a decrease in its wave number position with increase in boron content. We speculate that these structural modifications in the morphology and microstructure of CNTs might be due to the charge transfer from boron to the graphite matrix, resulting in shortening of the carbon-carbon bonds.

Phase stabilization by rapid thermal annealing in amorphous hydrogenated silicon nitride film

We have studied the effect of rapid thermal annealing (RTA) in the context of phase evolution and stabilization in hydrogenated amorphous silicon nitride (a-SiN(x):H) thin films having different stoichiometries, deposited by an Hg-sensitized photo-CVD (chemical vapor deposition) technique. RTA-treated films showed substantial densification and increase in refractive index. Our studies indicate that a mere increase in flow of silicon (Si)-containing gas would not result in silicon-rich a-SiN(x):H films. We found that out-diffusion of hydrogen, upon RTA treatment, plays a vital role in the overall structural evolution of the host matrix. It is speculated that less incorporation of hydrogen in as-deposited films with moderate Si content helps in the stabilization of the silicon nitride (Si(3)N(4)) phase and may also enable unreacted Si atoms to cluster after RTA. These studies are of great interest in silicon photonics where the post-treatment of silicon-rich devices is essential.

Tailoring the nature of magnetic coupling of Fe-porphyrin molecules to ferromagnetic substrates

We demonstrate that an antiferromagnetic coupling between paramagnetic Fe-porphyrin molecules and ultrathin Co and Ni magnetic films on Cu(100) substrates can be established by an intermediate layer of atomic oxygen. The coupling energies have been determined from the temperature dependence of x-ray magnetic circular dichroism measurements. By density functional theory+U calculations the coupling mechanism is shown to be superexchange between the Fe center of the molecules and Co surface-atoms, mediated by oxygen.

Protective or pathogenic immune response to genital chlamydial infection in women--a possible role of cytokine secretion profile of cervical mucosal cells

Little is known about genital mucosal immune response to chlamydial infection in women with or without sequelae (Chlamydia positive women with or without fertility disorders as infertility and multiple spontaneous abortions). Cervical lymphocytes were stimulated with chlamydial EBs and cytokine secretion was determined by ELISA, RT-PCR and ELISPOT assays. Stimulated cervical cells from women with fertility disorders (FD) secrete significantly (P<0.05) higher levels of IL-1beta, IL-6, IL-8 and IL-10 and cells from fertile women secrete significantly higher levels of IL-12 and IFN-gamma compared to other groups. RT-PCR analysis showed similar results for IFN-gamma and IL-12. For IL-10 and IL-4, mRNA expression levels were significantly higher (P<0.05) in cells obtained from women with FD compared to other groups. Results for ELISPOT assay were similar as those of RT-PCR. The results suggest that cytokine secretion profile of cervical cells may decide whether infection does not hamper fertility or will develop fertility disorder.

Electron field emission from graphitic nanoflakes grown over vertically aligned carbon nanotubes

Single step growth of self-assembled graphitic nanoflakes (GNF) over carbon nanotubes (CNT) on iron coated silicon(100) substrates is reported. These nanostructures were grown by varying the deposition time in a microwave plasma enhanced chemical vapor deposition reactor using acetylene, hydrogen and argon as reactant gases. Scanning electron microscope (SEM) studies of the deposited carbon films revealed that with increase in deposition time from 3 minutes to 6 minutes, the surface topography of the films transformed from one dimensional cylindrical nanostructure to flat-shaped two-dimensional nanoflakes. Carbon film deposited for 5 minutes showed improved surface coverage as compared to films deposited for 6 minutes i.e., surface area of the CNT film covered with nanoflakes increased as compared to carbon film deposited for higher durations. Field emission studies of films deposited at 5 minutes and 6 minutes showed increase in turn-on field, required for electron emission, from 2.7 V/microm to 2.9 V/microm respectively. However, such a combination of one dimension carbon and two dimension carbon may prove useful in applications where high surface area films are required.

The mountain-lowland debate: deforestation and sediment transport in the upper Ganga catchment

The Himalaya-Gangetic Plain region is the iconic example of the debate about the impact on lowlands of upland land-use change. Some of the scientific aspects of this debate are revisited by using new techniques to examine the role of deforestation in erosion and river sediment transport. The approach is whole-of-catchment, combining a history of deforestation with a history of sediment sources from well before deforestation. It is shown that deforestation had some effect on one very large erosional event in 1970, in the Alaknanda subcatchment of the Upper Ganga catchment, but that both deforestation and its effects on erosion and sediment transport are far from uniform in the Himalaya. Large magnitude erosional events occur for purely natural reasons. The impact on the Gangetic Plain of erosion caused by natural events and land cover change remains uncertain.