Significant enhancement in the cold emission characteristics of chemically synthesized super-hydrophobic zinc oxide rods by nickel doping.

The current article presents a huge enhancement in the field emission characteristics of zinc oxide (ZnO) micro/nanorods by nickel doping. The synthesis of pure and nickel-doped zinc oxide (ZnO) micro/nanorods was done by a simple low-temperature chemical method. Both the as-prepared pure and doped samples were analyzed by X-ray diffraction and electron microscopy to confirm the proper phase formation and the developed microstructure. UV-vis transmittance spectra helped in determining the band gap of the samples. Fourier-Transform Infrared Spectroscopy (FTIR) spectra showed the different bonds present in the sample, whereas X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of nickel in the doped sample. Photoluminescence (PL) spectra showed that after doping, the band-to-band transition was affected, whereas defect-induced transition had increased significantly. After the nickel doping, contact angle measurement revealed a significant decrease in the sample's surface energy, leading to a remarkably high water contact angle (within the superhydrophobic region). Simulation through ANSYS suggested that the doped sample has the potential to function as an efficient cold emitter, which was also verified experimentally. The cold emission characteristics of the doped sample showed a significant improvement, with the turn-on field (corresponding to J = 1 µA cm-2) reduced from 5.34 to 2.84 V µm-1. The enhancement factor for the doped sample reached 3426, approximately 1.5 times higher compared to pure ZnO. Efforts have been made to explain the results, given the favorable band bending as well as the increased number of effective emission sites.

Therapeutic Prospects in Preeclampsia - A Mini-Review.

BACKGROUND: Preeclapmsia (PE) is characterized by early onset symptoms such as elevated blood pressure, proteinuria and edema in the pregnant woman, and may result in seizures in the affected female. Currently, there are no therapeutic drugs available to treat this condition, but there are interventions to regulate the symptoms based on the gestational period of the fetus, although the largely favored option is delivery of the fetus and placenta. OBJECTIVE: A search for biomolecules associated with PE was conducted so as to identify diagnostic markers and therapeutic leads. RESULTS: The literature search resulted in the identification of biomolecules such as Corin and Placental Protein 13 (PP13), among others that are associated with PE. Thereby, giving an insight into the various mechanistic pathways involved in the causation of PE. However, it is also evident that PE cannot be solely attributed to any single mechanism but is due to an interplay of different factors that have led to the development of this disease condition. CONCLUSION: The identified biomarkers would ultimately help in understanding this complex disease and perhaps lead to the discovery of potential effective molecular targets for clinical trials, thereby providing a valuable therapeutic option for affected pregnant women.

1D-2D hybrids as efficient optoelectronic materials: a study on graphitic carbon nitride nanosheets wrapped with zinc oxide rods.

Zinc oxide (ZnO) nanorods (NRs) wrapped with graphitic carbon nitride (GCN) nanosheet (NS) hybrids have been synthesized by a simple chemical process. The as-prepared samples are characterized by X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, Fourier transformed infrared spectroscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The images obtained from the transmission electron microscopic study and the existence of C-N stretching modes as observed from Fourier transform infrared spectroscopy confirm the successful attachment of GCN NSs onto the ZnO NRs. It is seen that hybrid samples show broad photoluminescence (PL) emission with enhanced defect related emission along with a quenching effect due to the charge transfer mechanism. The results have been explained by taking into consideration the three different types of electron transitions occurring within the type-II band structure of the hybrid samples. Moreover a study on the conductivity of the samples is carried out under dark conditions and also under ultraviolet (UV) light irradiation. It is observed that the hybrid samples show significantly improved conductivity under both dark and UV irradiated conditions. The absorbance of the samples in the UV range shows better conductivity under UV conditions as compared to dark conditions.

Graphene-Anchored p-Type CuBO2 Nanocrystals for a Transparent Cold Cathode.

CuBO2 nanostructures were synthesized by employing a low-cost hydrothermal technique to combine into the CuBO2-RGO nanocomposite for the first time using chemically prepared graphene sheets. The nanohybrid samples were characterized for structural information using X-ray diffraction (XRD) that revealed the proper crystalline phase formation of CuBO2 unaltered by composite formation with graphene. Raman spectroscopic studies were employed to confirm the presence of graphene. A morphological study with field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) suggested the proper wrapping of RGO sheets over CuBO2 nanocubes. Moreover, the close proximity of lattice planes of CuBO2 and RGO to each other was observed in high-resolution TEM studies that were correlated with the Raman spectroscopic studies. Finally, the samples were characterized to study the field emission (FE) properties of the same using a laboratory-made high-vacuum field-emission setup. Finite-element-based theoretical simulation studies were carried out to explain and compare the field emission properties with the experimental results. The FE properties of the composite samples were found to be tuned by the nature of wrapping the RGO sheets over the CuBO2 nanocubes, which was typically dependent upon the spiky morphology of the nanocubes.

Testicular gametogenic and steroidogenic activities in chlorpyrifos insecticide-treated rats: a correlation study with testicular oxidative stress and role of antioxidant enzyme defence systems in Sprague-Dawley rats.

The present works examined an adverse effect of chlorpyrifos insecticide on testes and lipid peroxidation at low doses (5 mg-10 mg kg(-1) body weight) and the role of antioxidant enzymes systems at higher doses (20-30 mg kg(-1) body weight) in albino rats. At low doses, reduction in plasma levels of testosterone and FSH and LH hormones along with the significant shrinkage of seminiferous tubules and gametogenic changes in germ cells were noticed. But these changes were restored with the revival of serum testosterone, FSH and LH along with regression of testis at higher doses. Similarly, level of testicular lipid peroxidation was elevated, whereas levels of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and steroidogenic enzymes activities (Δ(5) , 3ß-hydroxysteroid dehydrogenase and 17ß-hydroxysteroid dehydrogenase) were reduced significantly at low doses. But, rat testes showed a significant decrease in lipid peroxidation and concomitant increase in antioxidant enzymes and steroidogenic enzymes activities at higher doses. Results showed that at higher doses of chlorpyrifos treatments, rat testes were shown to trigger their natural defence mechanism which became operative possibly through corrective measure of synthesis of antioxidant defence enzymes and steroidogenic enzymes and pituitary gonadotrophins hormone feedback mechanisms.

Absence of Phlebotomus argentipes Ann & Brun. (Diptera: Psychodidae) the vector of Indian kala-azar from Kamrup district, Assam.

In the past Assam was devastated by epidemics of Kala-azar. However, inspite of resurgence of this disease in Bihar and neighbouring areas Assam has remained untouched by this disease since the mid 1950s so far. The study undertaken in Kamrup district, sought to provide an entomological explanation for Assam's present freedom from Kala-azar. Sandfly collections were made in 15 villages. Three different methods were used; namely hand collections by aspirator and torch, sticky traps and examination of soft parts of cattle in the villages for mating swarms. 1049 sandflies were collected which did not include any specimens of P. argentipes. The vector of Indian Kala-azar has either been eliminated by continuous insecticide spraying in this high P. falciparum, and chloroquine resistance area or reduced to such low levels of prevalence that routine sampling methods are unable to reveal its presence. The implications of this finding are discussed in relation to Kala-azar control in India, in general.

The effect of topical isoprenaline on psoriatic skin.

Twelve patients with psoriasis were treated by the topical application of 0.1% isoprenaline sulphate ointment for 10 days. Topical white vaseline was used as a control in three patients with psoriasis. The mean glycogen level was found to be decreased significantly (from 120 +/- s.d. 40 to 58 +/- s.d. 26 mg/100 g of wet weight of involved skin) after topical application of 0.1 isoprenaline sulphate and the scaling also disappeared. Topical application of white vaseline did not produce any significant change in glycogen levels or scaling. The changes after isoprenaline application may have been due to an increase in the ratio of cyclic AMP/cyclic GMP which inhibited cell turnover and increased glycogenolysis.