Experimental (FT-IR, FT-Raman, UV and NMR) and quantum chemical studies on molecular structure, spectroscopic analysis, NLO, NBO and reactivity descriptors of 3,5-Difluoroaniline

Comprehensive investigation of geometrical and electronic structure in ground as well as the first excited state of 3,5-Difluoroaniline (C6H5NF2) was carried out. The experimentally observed spectral data (FT-TR and FT-Raman) of the title compound was compared with the spectral data obtained by DFT/B3LYP method using 6-311++G(d,p) basis set. The molecular properties like dipole moment, polarizability, first static hyperpolarizability, molecular electrostatic potential surface (MEPs), and contour map were calculated to get a better insight of the properties of the title molecule. Natural bond orbital (NBO) analysis was applied to study stability of the molecule arising from charge delocalization. UV-Vis spectrum of the title compound was also recorded and the electronic properties, such as Frontier orbitals and band gap energies were measured by TD-DFT approach. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were presented. Global and local reactivity descriptors were computed to predict reactivity and reactive sites on the molecule. (1)H and (13)C NMR spectra by using gauge including atomic orbital (GIAO) method of studied compound were compared with experimental data obtained. Moreover, the thermodynamic properties were evaluated.

A combined approach for the enhancement and segmentation of mammograms using modified fuzzy C-means method in wavelet domain

In this paper, a combined approach for enhancement and segmentation of mammograms is proposed. In preprocessing stage, a contrast limited adaptive histogram equalization (CLAHE) method is applied to obtain the better contrast mammograms. After this, the proposed combined methods are applied. In the first step of the proposed approach, a two dimensional (2D) discrete wavelet transform (DWT) is applied to all the input images. In the second step, a proposed nonlinear complex diffusion based unsharp masking and crispening method is applied on the approximation coefficients of the wavelet transformed images to further highlight the abnormalities such as micro-calcifications, tumours, etc., to reduce the false positives (FPs). Thirdly, a modified fuzzy c-means (FCM) segmentation method is applied on the output of the second step. In the modified FCM method, the mutual information is proposed as a similarity measure in place of conventional Euclidian distance based dissimilarity measure for FCM segmentation. Finally, the inverse 2D-DWT is applied. The efficacy of the proposed unsharp masking and crispening method for image enhancement is evaluated in terms of signal-to-noise ratio (SNR) and that of the proposed segmentation method is evaluated in terms of random index (RI), global consistency error (GCE), and variation of information (VoI). The performance of the proposed segmentation approach is compared with the other commonly used segmentation approaches such as Otsu's thresholding, texture based, k-means, and FCM clustering as well as thresholding. From the obtained results, it is observed that the proposed segmentation approach performs better and takes lesser processing time in comparison to the standard FCM and other segmentation methods in consideration.

Intra oral periapical radiography - basics yet intrigue: A review

There had been a long standing requirement for dental students which would help them to understand the basic techniques for intraoral periapical radiographs. Intra oral periapical radiography is an adjunct to the clinical examination and provides useful information about the joint components. The periapical view shows the entire crown and root of the teeth which provides vital information to aid in the diagnosis of the most common dental diseases. This article highlights the basic principle, techniques, advantages and disadvantages of intraoral periapical radiography. DOI: http://dx.doi.org/10.3329/bjdre.v4i2.20255 Bangladesh Journal of Dental Research and Education Vol.4(2) 2014: 83-87

pH- and thermosensitive thin lipid layer coated mesoporous magnetic nanoassemblies as a dual drug delivery system towards thermochemotherapy of cancer

A new pH-sensitive and thermosensitive dual drug delivery system consisting of thin lipid layer encapsulated mesoporous magnetite nanoassemblies (MMNA) has been developed which can deliver two anticancer drugs simultaneously. The formulation of lipid layer used is 5:2:2:2 w/w, DPPC:cholesterol:DSPE-PEG2000:MMNA. The structure, morphology and magnetic properties of MMNA and lipid coated MMNA (LMMNA) were thoroughly characterized. This hybrid system was investigated for its ability to carry two anticancer drugs as well as its ability to provide heat under an alternating current magnetic field (ACMF). A very high loading efficiency of up to ∼81% of doxorubicin hydrochloride (DOX) with an ∼0.02 mg mg(-1) loading capacity and ∼60% of paclitaxel (TXL) with an ∼0.03 mg mg(-1) loading capacity are obtained with LMMNA. A sustained release of drug is observed over a period of 172 h, with better release, of ∼88:53% (DOX:TXL), at pH 4.3 compared to the ∼28:26% (DOX:TXL) in physiological conditions (pH 7.4). An enhanced release of ∼72 and ∼68% is recorded for DOX and TXL, respectively, during the first hour with the application of an ACMF (∼43°C). A greater in vitro cytotoxic effect is observed with the two drugs compared to them individually in HeLa, MCF-7 and HepG2 cancer cells. With the application of an ACMF for 10 min, the cell killing efficiency is improved substantially due to simultaneous thermo- and chemotherapy. Confocal microscopy confirms the internalization of drug loaded MMNA and LMMNA by cells and their morphological changes during thermochemotherapy.

Study of Schottky contact in binary and ternary hybrid CdSe quantum dot solar cells

Hybrid binary and ternary organic solar cell devices were fabricated from P3HT–PCBM with CdSe quantum dot materials.

Oral mucosal injury in oncology patients: perspectives on maturation of a field

In the past decade, there have been important strategic advances relative to pathobiological modeling as well as clinical management for oral mucositis caused by cancer therapies. Prior to the 1990s, research in this field was conducted by a relatively small number of basic and clinical investigators. Increasing interest among researchers and clinicians over the past twenty years has produced a synergistic outcome characterized by a number of key dynamics, including novel discovery models for pathobiology, increased experience in designing and conducting clinical trials, and creation of international collaborations among cancer care professionals who in turn have modeled clinical care paradigms based on state-of-the-science evidence. This maturation of the science and its clinical translation has positioned investigators and oncology providers to further accelerate both the foundational research and the clinical modeling for patient management in the years ahead. The stage is now set to further capitalize upon optimizing the interactions across this interface, with the goal of strategically enhancing management of patients with cancer at risk for this toxicity while reducing the cost of cancer care.

Non-specific sex-differential effect of DTP vaccination may partially explain the excess girl child mortality in Ballabgarh, India

OBJECTIVE

To test the hypothesis that a gender differential exists in the effect on child mortality of BCG, DTP, measles vaccine as administered under programme conditions in Ballabgarh HDSS area.

METHODS

All live births in 28 villages of Ballabgarh block in North India from 2006 to 2011 were followed until 31 December 2011 or 36 months of age whichever was earlier. The period of analysis was divided into four time periods based on eligibility for vaccines under the national immunisation schedule (BCG for tuberculosis, primary and booster doses of diphtheria-tetanus-pertussis and measles). Cox proportional hazards regression was used to assess the association between sex and risk of mortality by vaccination status using age as the timescale in survival analysis and adjusting for wealth index, access to health care, the presence of a health facility in the village, parental education, type of family, birth order of the child and year of birth.

RESULTS

702 deaths (332 boys and 370 girls) occurred among 12,142 children in the cohort in the 3 years of follow-up giving a cumulative mortality rate of 57.5 per 1000 live births with 35% excess girl child mortality. Age at vaccination for the four vaccines did not differ by sex. There was significant excess mortality among girls after immunisation with DTP, for both primary (HR 1.65; 95% CI:1.17-2.32) and DTPb (2.21; 1.24-3.93) vaccinations. No significant excess morality among girls was noted after exposure to BCG 1.06 (0.67-1.67) or measles 1.34 (0.85-2.12) vaccine.

CONCLUSION

This study supports the contention that DTP vaccination is partially responsible for higher mortality among girls in this study population.

Maxillary sinus tuberculosis: various presentations

Tuberculosis (TB) of the maxillary sinus is rare. We describe the clinical presentation, management and outcome in two human immunodeficiency virus (HIV) seronegative patients with histopathologically confirmed maxillary sinus TB. One of the patients who presented earlier in the course of the disease could be managed with antituberculosis treatment alone, while the other who presented late required surgical intervention as well.

Palm top plasma focus device as a portable pulsed neutron source

Development of a palm top plasma focus device generating (5.2 ± 0.8) × 10(4) neutrons∕pulse into 4π steradians with a pulse width of 15 ± 3 ns is reported for the first time. The weight of the system is less than 1.5 kg. The system comprises a compact capacitor bank, a triggered open air spark gap switch, and a sealed type miniature plasma focus tube. The setup is around 14 cm in diameter and 12.5 cm in length. The energy driver for the unit is a capacitor bank of four cylindrical commercially available electrolytic capacitors. Each capacitor is of 2 μF capacity, 4.5 cm in diameter, and 9.8 cm in length. The cost of each capacitor is less than US$ 10. The internal diameter and the effective length of the plasma focus unit are 2.9 cm and 5 cm, respectively. A DC to DC converter power supply powered by two rechargeable batteries charges the capacitor bank to the desired voltage and also provides a trigger pulse of -15 kV to the spark gap. The maximum energy of operation of the device is 100 J (8 μF, 5 kV, 59 kA) with deuterium gas filling pressure of 3 mbar. The neutrons have also been produced at energy as low as 36 J (3 kV) of operation. The neutron diagnostics are carried out with a bank of (3)He detectors and with a plastic scintillator detector. The device is portable, reusable, and can be operated for multiple shots with a single gas filling.

Multidrug resistance in cancer (review)

The development of resistance to anticancer agents during treatment is a major obstacle in the chemotherapy of cancer. Cells expressing high levels of the P-glycoprotein exhibit a multidrug resistance phenotype. The P-glycoprotein is a membrane phosphoprotein which serves as a drug efflux pump to reduce intracellular drug accumulation, and hence the cytotoxicity of anticancer drugs. Several studies have shown that protein kinase activators and inhibitors may modulate the biological activity of P-glycoprotein through covalent modification by phosphorylation. Most of these drugs may have additional mechanisms of action and may alter drug accumulation within multidrug resistant cells with or without their effects on phosphorylation of P-glycoprotein. In addition, transcriptional regulation of MDR 1 gene has been found to be regulated by protein kinase A type I and protein kinase C. Therefore, these kinases may be important candidates in studies of the reversal of multidrug resistance and hence in enhancing the efficacy of anticancer drugs.

Polyelectrolyte coated polymeric nanoparticles for controlled release of docetaxel

Polyelectrolyte coatings are effective means of minimizing the rate of release of small molecules from a nanoparticle system. The current investigation aim at developing biodegradable drug delivery carriers composed of three types of polymers viz poly(lactide-co-glycolic) acid [PLGA], poly(lactide-co-glycolic) acid-polyethylene imine [PLGA-PEI] and poly lactic acid [PLA]. The PLGA and PLGA-PEI nanoparticles were in the size range approximately 150 nm while PLA nanoparticles were approximately 80 nm in size respectively. The nanoparticles were found to encapsulate 66%, 62% and 65% of the hydrophobic drug, Docetaxel (DOCE) respectively. "Layer by Layer (LbL)" self assembly technique was then performed to coat these particles with polyelectrolyte thin films (PEs). DLS studies showed hydrodynamic diameter of 330 nm, 350 nm and 310 nm for the coated PLGA, PLGA-PEI and PLA nanoparticles respectively, while SEM and TEM studies demonstrated that after coating the particle sizes were approximately 200 nm for all the three nanoparticles. In vitro drug release studies demonstrated that at the end of 24 hours, about 83%, 90% and 88% of drug was released from uncoated PLA, PLGA-PEI and PLGA nanoparticles respectively. Using LbL coating, the same amount of the drug was found to be released in a sustained way for up to 7 days for PLGA and up to 6 days for PLGA-PEI and PLA nanoparticles. In vitro cytocompatibility studies were carried out with each system and the cell viability at end of 48 hours was found to be in the range of 70% to 100%. Current approach of sustained drug delivery can help in improving the therapeutic efficiency of the breast cancer drug, DOCE.