Determination of surface dose rate of indigenous (32)P patch brachytherapy source by experimental and Monte Carlo methods

Isotope production and Application Division of Bhabha Atomic Research Center developed (32)P patch sources for treatment of superficial tumors. Surface dose rate of a newly developed (32)P patch source of nominal diameter 25 mm was measured experimentally using standard extrapolation ionization chamber and Gafchromic EBT film. Monte Carlo model of the (32)P patch source along with the extrapolation chamber was also developed to estimate the surface dose rates from these sources. The surface dose rates to tissue (cGy/min) measured using extrapolation chamber and radiochromic films are 82.03±4.18 (k=2) and 79.13±2.53 (k=2) respectively. The two values of the surface dose rates measured using the two independent experimental methods are in good agreement to each other within a variation of 3.5%. The surface dose rate to tissue (cGy/min) estimated using the MCNP Monte Carlo code works out to be 77.78±1.16 (k=2). The maximum deviation between the surface dose rates to tissue obtained by Monte Carlo and the extrapolation chamber method is 5.2% whereas the difference between the surface dose rates obtained by radiochromic film measurement and the Monte Carlo simulation is 1.7%. The three values of the surface dose rates of the (32)P patch source obtained by three independent methods are in good agreement to one another within the uncertainties associated with their measurements and calculation. This work has demonstrated that MCNP based electron transport simulations are accurate enough for determining the dosimetry parameters of the indigenously developed (32)P patch sources for contact brachytherapy applications.

Studies on the growth and characterization of a non linear optical crystal: 3 Hydroxy Pyridinium Tartrate Mono Hydrate (3HPTMH)

Single crystals of 3 Hydroxy Pyridinium Tartrate Mono Hydrate (3HPTMH) was synthesised and successfully grown in mixed solvent of ethanol and water by slow evaporation technique at room temperature. 3HPTMH belongs to the orthorhombic crystal system with space group P212121. The lattice parameters of 3HPTMH are a=7.4597(2)Å, b=8.7012(3)Å, c=17.8786(5)Å, V=1160.47(6)Å(3), obtained by single crystal X ray diffraction studies. Hyperpolarizability and HOMO-LUMO analysis were performed for grown crystal using DFT calculations using Gaussian 03 software. Functional groups were identified by FT-IR studies. The lower cut-off wavelength of the 3HPTMH has been identified by UV-Vis study. The thermal behavior has been studied by thermal gravimetric analysis and differential thermal analysis. The powder second harmonic generation efficiency of 3HPTMH was compared with KDP.

Synthesis, characterization, biological evaluation and docking studies of macrocyclic binuclear manganese(II) complexes containing 3,5-dinitrobenzoyl pendant arms

A series of bis(phenoxo) bridged binuclear manganese(II) complexes of the type [Mn2L(1-3)](ClO4)2 (1-3) containing 3,5-dinitrobenzoyl pendant-arms have been synthesized by cyclocondensation of 2,6-diformyl-4-R-phenols (where R=CH3, C(CH3)3 or Br) with 2,2'-3,5-dinitrobenzoyliminodi(ethylamine) trihydrochloride in the presence of manganese(II) perchlorate. The IR spectra of complexes indicate the presence of uncoordinated perchlorate anions. The UV-Vis spectra of complexes suggest the distorted octahedral geometry around manganese(II) nuclei. The EPR spectra of Mn(II) complexes show a broad signal with g value 2.03-2.04, which is characteristic for octahedral high spin Mn(2+) complex. The observed room temperature magnetic moment values of the Mn(II) complexes (5.60-5.62B.M.) are less than the normal value (5.92B.M.), indicating weak antiferromagnetic coupling interaction between the two metal ions. Electrochemical studies of the complexes show two distinct quasi-reversible one electron transfer processes in the cathodic (E(1)pc=-0.73 to -0.76V, E(2)pc=-1.30 to -1.36V), and anodic (E(1)pa=1.02-1.11V, E(2)pa=1.32-1.79V) potential regions. Antibacterial efficacy of complexes have been screened against four Gram (-ve) and two Gram (+ve) bacterial strains. The DNA interaction studies suggest that these complexes bind with CT-DNA by intercalation, giving the binding affinity in the order 1>2>3. All the complexes display significant cleavage activity against circular plasmid pBR322 DNA. Docking simulation was performed to insert complexes into the crystal structure of EGFR tyrosine kinase and B-DNA at active site to determine the probable binding mode.

Crystal structure of N'-[(E)-(4-chloro-phen-yl)(phen-yl)methyl-idene]-4-methyl-benzene-sulfono-hydrazide

The title compound, C20H17ClN2O2S, was obtained by a condensation reaction between 4-chloro-benzo-phenone and tosyl hydrazide. The plane of the methyl-substituted benzene ring forms dihedral angles of 20.12 (12) and 78.43 (13)° with those of the chlorine-substituted benzene ring and the benzene ring, respectively, with the last two rings forming a dihedral angle of 67.81 (13)°. The chlorine substituent was also found to be 0.868 (2):0.132 (2) disordered over these two rings. In the crystal, mol-ecules are linked through pairs of N-H⋯O hydrogen bonds, giving centrosymmetric cyclic dimers [graph set R 2 (2)(8)], which are linked by weak C-H⋯O and C-H⋯Cl inter-actions into a chain structure which extends along the a-axis direction.

Modification of human islet preparation: an effective approach to improve graft outcome after islet transplantation?

Revascularisation of transplanted islets is an essential prerequisite for graft survival and function. However, current islet isolation procedures deprive the islets of endothelial tubulets. This may have a detrimental effect on the revascularisation process of islets following transplantation. We hypothesise that modification of the isolation procedure that preserves islet endothelial vessels may improve the islet revascularisation process following transplantation. Here, we present a modified islet isolation method by which a substantial amount of endothelial cells still attached to the islets could be preserved. The islets with preserved endothelial cells isolated by this method were revascularised within 3 days, not observed in islets isolated by standard methods. Further, we observed that grafts of islets isolated by standard methods had more patches of dead tissue than islet grafts obtained by the modified method, indicating that attached endothelial cells may play an important role in the islet revascularisation process and potentially help to improve the transplantation outcome.

Outcomes for adults with type 1 diabetes referred with severe hypoglycaemia and/or referred for islet transplantation to a specialist hypoglycaemia service

Islet transplantation alone (ITA) is indicated for patients with type 1 diabetes (T1D) with disabling severe hypoglycaemia (SH) despite optimised medical therapy. We examined outcomes for patients referred to an islet transplant unit with recurrent SH. Retrospective case note audit of 45 patients with ≥1 SH per year who were referred to our ITA unit between 2009-2012; 36 patients attended follow-up appointments. The cohort was 52.8% male, mean (± SD) age 43.9 (± 11.4) years, and duration of diabetes 26.5 (± 12.9) years. Baseline HbA1c was 8.3% (± 1.7) (67.2 mmol/mol), median (IQR) frequency of SH was 6.0 (2.0-24.0) per/patient/year and 83.3% had impaired awareness of hypoglycaemia (IAH). 80.6% of patients were referred from other secondary diabetes services, 22.2% had completed structured education, and 30.6% were using continuous subcutaneous insulin infusion (CSII). Seventeen patients were optimised with conventional therapy; SH reduced from 2.0 (1.5-9.0) to 0.0 (0.0-0.5) episodes/patient/year; p<0.001, and there was concurrent improvement in HbA1c (8.1-7.7%; 65.0 vs. 60.7 mmol/mol; p=0.072). Ten patients were listed for transplantation as they were not optimised despite structured education, CSII, and continuous glucose monitoring (CGM). The remaining 9 had a reduction in SH [7.0 (4.8-40.5) to 4.0 (2.5-6.3) episodes/patient/year; p=0.058] and either left the service (n=5) or are still being optimised (n=4). In conclusion, 47.2% of patients presenting with problematic hypoglycaemia resolved with optimal medical therapy, with a further 25% achieving clinically relevant improvement, however 27.8% required transplantation despite access to all therapies. Provision of expertise in hypoglycaemia management is essential to focus limited transplant resources on those who need it most.

Portomesenteric venous gas: A late complication of pneumatosis intestinalis

BACKGROUND

The pneumatosis intestinalis is an entity with multiple aetiologies and may be associated with a fatal outcome when present on plain radiographs. When associated with the presence of portomesenteric venous gas (PMVG) it is typically the result of bowel ischaemia.

METHODS AND RESULTS

We are presenting a case of a 43 year old male who presented with a two days history of haematemesis, generalised abdominal pain and distension. Computed tomography (CT) scan revealed a gross amount of air within the portal venous system and small bowel dilatation to the level of distal ileum was also seen with associated pneumatosis intestinalis. Emergency laparotomy was conducted which demonstrated a simple band adhesion resulting in bowel ischaemia. The patient was making a good post-operative recovery complicated only by sub-therapeutic treatment of schizophrenia.

CONCLUSION

The presence of gas within the portal venous system and PI in adults can indicate severe life-threatening disease. This requires early surgical intervention in those patients with a clinical suspicion of bowel ischaemia, and with radiological signs. This may avoid significant mortality.

Crystal structure of (E)-N'-(4-chloro-benzyl-idene)-4-methyl-benzene-sulfono-hydrazide: a hexa-gonal polymorph

The title compound, C14H13ClN2O2S, crystallized in the enanti-omorphic defining hexa-gonal space group P61 [Flack parameter = -0.02 (7)]. The partially hydrated form of the same compound, crystallizing in the triclinic space group P-1, has been reported previously [Kia et al. (2009b). Acta Cryst. E65, o1119], as has the crystal structure of the bromo derivative, also crystallizing in the space group P-1 [Kia et al. (2009a). Acta Cryst. E65, o821]. The title mol-ecule is non-planar with the planes of the benzene rings being inclined to one another by 76.62 (13)°, and has an E conformation about the C=N bond. In the crystal, mol-ecules are linked via N-H⋯O hydrogen bonds forming 61 helical chains running along [001]. The chains are linked via C-H⋯O hydrogen bonds, C-H⋯π inter-actions and short Cl⋯O [3.015 (3) Å] inter-actions, forming a three-dimensional structure.

A detailed perceptive on the growth and characterization studies of para amino hippuric acid (PAHA) single crystals

Single crystals of para amino hippuric acid (PAHA) were grown by slow evaporation technique. The spectral and its structural properties of the crystals were studied by FT-IR, micro-Raman and factor group analysis. The optical transparency in the UV-Visible regions was found to be good for non-linear optics (NLO) applications. Thermogravimetric analysis (TGA) and Differential Thermal Analysis (DTA) showed that the compound decomposes beyond 300°C. The dielectric behavior of the compound predicts low dielectric loss at high frequency applied whereas in the case of mechanical behavior of the specimen hardness increases with increasing applied load. After certain weight increase, hardness gets saturated in the region of ≥110. Relative second harmonic efficiency of the compound is found to be 1.8 times greater than that of potassium di-phosphate reference.

Bioassay-guided isolation, identification and molecular ligand-target insight of lipoxygenase inhibitors from leaves of Anisomeles malabarica R.Br

Background:

Anisomeles malabarica R. Br. (Lamiaceae) is extensively used in traditional medicine in major parts of India for several medicinal purposes, including their use in rheumatism.

Materials and Methods:

The air-dried leaves of A. malabarica were extracted with ethanol, defatted with n-hexane and then successively partitioned into chloroform and n-butanol fractions. Bioassay-guided fractionation and purification of chloroform fraction from A. malabarica lead to the isolation of lipoxygenase (LOX) inhibitors. The structures of isolated compounds were elucidated by ultraviolet, infrared, ¹H nuclear magnetic resonance (NMR), ¹³C NMR and mass spectrometry spectroscopic techniques and assessed further by in vitro soybean lipoxygenase (sLOX) assay. In addition, the enzyme type inhibition was evaluated through molecular docking technique as a part of computational study.

Results:

The bioactive compounds 3, 4 dihydroxy benzoic acid (1) and 4’, 5, 7-trihydroxyflavone (2) were isolated from chloroform fraction of A. malabarica, whose bioactivity was observed to be dose-dependent compared to n-butanol fraction. Among the compounds, 3, 4 dihydroxy benzoic acid showed significant sLOX inhibitory activity with 74.04% ±2.6% followed by 4’, 5, 7-trihydroxyflavone (34.68% ±1.9%). The computational analysis of compounds showed their molecular interaction with important amino acid residues and nonheme iron atom in the catalytic site of LOX by enlightening their potential binding mode at molecular level.

Conclusions:

The LOX inhibitory constituents were identified from A. malabarica by means of bioassay-guided fractionation process. The results derived from in vitro and computational experiments confirm the potential of the isolated compounds and provide additional evidence for its traditional use in inflammatory disorders.

Antibacterial, DNA interaction and cytotoxic activities of pendant-armed polyamine macrocyclic dinuclear nickel(II) and copper(II) complexes

A series of dinuclear nickel(II) and copper(II) complexes (1-6) of hexaaza macrocycles of 2,6-diformyl-4-methylphenol with three different benzoyl pendant-arms, 2,2'-benzoyliminodi(ethylamine) trihydrochloride (L), 2,2'-4-nitrobenzoyliminodi(ethylamine) trihydrochloride (L') and 2,2'-3,5-dinitrobenzoyliminodi(ethylamine) trihydrochloride (L″) have been synthesized and characterized by spectral methods. The electrochemical studies of these complexes depict two irreversible one electron reduction processes around E(1)pc=-0.62 to -0.76 V and E(2)pc=-1.21 to -1.31, and nickel(II) complexes (1-3) exhibit two irreversible one electron oxidation processes around E(1)pa=1.08 to 1.14 V and E(2)pa=1.71 to 1.74 V. The room temperature magnetic moment values (μeff, 1.52-1.54 BM) indicate the presence of an antiferromagnetic interaction in the binuclear copper(II) complexes (4-6) which is also observed from the broad ESR spectra with a g value of 2.14-2.15. The synthesized complexes (1-6) were screened for their antibacterial activity. The results of DNA interaction studies indicate that the dinuclear complexes can bind to calf thymus DNA by intercalative mode and display efficient cleavage of plasmid DNA. Further, the cytotoxic activity of complexes 2, 5 and 6 on human liver adenocarcinoma (HepG2) cell line has been examined. Nuclear-chromatin cleavage has also been observed with PI staining and comet assays.

Investigations on the vibrational modes and non-linear optical properties of 4-Fluoro Chalcone crystal

Organic Nonlinear Optical (NLO) crystals of 4-fluorochalcone (4FC) were synthesized and grown by slow evaporation solution growth method. The grown crystals have been characterised by powder X-ray diffraction, factor group analysis, FTIR, FT-Raman, UV-Vis Spectroscopy, powder SHG and Vickers microhardness tests. Theoretical quantum chemical analysis were performed to determine the first order hyperpolarizability (β) and HOMO-LUMO analysis of the title compound were computed by GAUSSIAN 03 package.

UV-Specific (320-365 nm) Digital Camera Based On a 128×128 Focal Plane Array of GaN/AlGaN p-i-n Photodiodes

An ultraviolet-specific (320-365 nm) digital camera based on a 128×128 array of backside-illuminated GaN/AlGaN p-i-n photodiodes has been successfully developed. The diode structure consists of a base n-type layer of AlGaN (~23% Al) followed by undoped and then p-type GaN layers deposited by metal organic vapor phase epitaxy. Double-side polished sapphire wafers serve as transparent substrates. Standard photolithographic, etching, and metallization procedures were employed to fabricate the devices. The fully-processed photodiode array was hybridized to a silicon readout integrated circuit (ROIC) using In bump bonds for electrical contact. The UV camera was operated at room temperature at frame rates ranging from 15 to 240 Hz. A variety of UV scenes were successfully recorded with this configuration.

Solar-Blind AlGaN Heterostructure Photodiodes

A backside-illuminated solar-blind UV detector based on an AlGaN p-i-n heterostructure has been successfully synthesized, fabricated and tested. The p-i-n photodiode structure consists of a 1.0 μm n-type Al0.64Ga0.36N:Si layer grown by MOVPE onto a low temperature AlN buffer layer on a polished sapphire substrate. On top of this base layer is a 0.2 μm undoped Al0.47Ga0.53N active layer and a 0.5 μm p-type Al0.47Ga0.53N:Mg top layer. Square mesas of area A = 4 × 10−4 cm2 were obtained by reactive ion etching using BCl3. The solar-blind photodiode exhibits a very narrow UV spectral responsivity band peaked at 273 nm with a FWHM = 21 nm. Maximum responsivity R = 0.051 A/W at 273 nm, corresponding to an internal quantum efficiency of 27%. R0A values up to 8 × 107Ω-cm2 were obtained, corresponding to D* = 3.5 × 1012 cm Hz1/2W−1 at 273 nm.

Fabrication and operation of a two-dimensional ion-trap lattice on a high-voltage microchip

Microfabricated ion traps are a major advancement towards scalable quantum computing with trapped ions. The development of more versatile ion-trap designs, in which tailored arrays of ions are positioned in two dimensions above a microfabricated surface, will lead to applications in fields as varied as quantum simulation, metrology and atom-ion interactions. Current surface ion traps often have low trap depths and high heating rates, because of the size of the voltages that can be applied to them, limiting the fidelity of quantum gates. Here we report on a fabrication process that allows for the application of very high voltages to microfabricated devices in general and use this advance to fabricate a two-dimensional ion-trap lattice on a microchip. Our microfabricated architecture allows for reliable trapping of two-dimensional ion lattices, long ion lifetimes, rudimentary shuttling between lattice sites and the ability to deterministically introduce defects into the ion lattice.

In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC50= 90 μg/ml), superoxide radical scavenging assay (IC50= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC50= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC50= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC50= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.

Prevalence and etiology of subclinical mastitis among buffaloes (Bubalus bubalus) in Namakkal, India

Milk samples from 206 apparently healthy buffaloes of marginal farmers maintained under the prevailing field conditions were screened for Subclinical Mastitis (SCM) to determine its prevalence and etiology by White Side Test (WST), California Mastitis Test (CMT), Somatic Cell Count (SCC) and Bacteriological examination. 26.20% of animals were positive for SCM in SCC and bacteriological examination. Prevalence in graded Murrah buffaloes were found to be higher compared to graded Surti and Non-descript breeds. The prevalence of SCM was highest in above 6th stage of lactation. Single quarter infection (51.85%) was more common compared to multiple quarter infection. Hind (83.34%) and left side (57.41%) quarters were more prone to SCM. The indirect tests such as WST and CMT were found to be closely agreement with SCC and bacteriological examination. Due to their efficacious, easy to perform and interpret, these tests can effectively be employed to detect SCM under field conditions. Somatic cell count of = 3,00,000/mL of milk was regarded as the upper limit for normal buffaloes. The SCC of = 3,00,000/mL of milk with positive bacterial growth were used to diagnose SCM in the present study. Staphylococcus sp. 25 (46.30%) was the most common pathogens isolated from SCM followed by Streptococcus sp. 11 (20.37%) and E. coli 06 (11.11%) of the 54 bacterial isolates. Monobacterial and mixed bacterial infections were observed in 47 (87.04%) and 7 (12.96%) cases respectively.