TiO2/AgO composites by one step photo reduction technique as electron transport layers (ETL) for dye-sensitized solar cells

Dye-sensitized solar cell's electron transport layer is responsible for transporting photo-generated electrons to the outer circuit. Utilizing localized surface plasmon resonance (SPR), light absorption could be enhanced to a greater degree, which can drive dye molecules to excited state more effectively than far-field light. In this work, TiO₂ nanoparticles were prepared by solvothermal method, and Ag nanoparticles were decorated over TiO₂ surface through photodeposition method. XRD data of the TiO₂ sample exhibits anatase phase and in the Ag nanoparticle decorated TiO₂ sample, peaks corresponding to (111) planes of Ag was observed. UV-Vis absorption analysis of the TiO₂ and Ag decorated TiO₂ samples showed absorption in the UV region for the TiO_2, and the SPR effect was detected for the Ag deposited TiO₂ samples. Ag nanoparticles decorated over TiO₂ was observed to be spherical in shape through the images from transmission electron microscope. Presence of both Ag and AgO in the prepared sample was revealed through the data from X-ray photoelectron spectroscopy. The prepared material was used as photoanodes in the construction of the DSSCs, and their performance was evaluated.

Recent advances in electrochemical sensor developments for detecting emerging pollutant in water environment

In the latest times, considerable studies have been performed closer to detecting emerging pollutant such as paracetamol in wastewater. Electrochemical sensor developments have recently started to determine in fewer concentrations effectively. The detection of paracetamol using standard protocols corresponding to electroanalytical techniques has a greater impact noticed in directing the detecting process toward biosensors. Non-enzymatic sensors are the peak of all electro analysis approaches. Functionalized materials, such as metal oxide nanoparticles, conducting polymers, and carbon-based materials for electrode surface functionalization have been used to create a fortification for distributing passive enzyme-free biosensors. Synergic effects are possible by enhancing loading capacity and mass transfer of reactants for attaining high analytical sensitivity using a variety of nanomaterials with large surface areas. The main focus of this study is to address the prevailing issues in the identification of paracetamol with the tasks in the non-enzymatic sensors field, followed by the useful methods of electro analysis studies.

Enabling Taguchi method with grey relational analysis to optimize the parameters of TiO2/ZnO heat transfer nanofluid for heat pipe application

Our previous work demonstrated that the TiO2/ZnO (1:1) nanocomposite suspended in ethylene glycol with CTAB (0.5 ml) as surfactant exhibits better heat transfer property than TiO2 and ZnO nanofluid. As an extension, the influence of parameters such as wt.% of ZnO Nps in TiO2/ZnO nanocomposite (0 wt.%, 25 wt.%, 50 wt.%, and 100 wt.%), the quantity of CTAB (250 μl, 500 μl, 750 μl, and 1000 μl) and vol.% of TiO2/ZnO nanocomposite (1 vol.%, 2 vol.%, 4 vol.%, and 8 vol.%) are analyzed through Taguchi design constructed with L16 orthogonal array is emphasized in the present work. As per the Taguchi design, the responses such as viscosity, thermal conductivity, and normalized height % for the set of input parameters are evaluated. Besides, the multiple responses are graded employing Grey relational analysis and the optimum set of parameters to achieve the preparation of the best nanofluid is identified as 25 wt.% ZnO, 1 vol.% nanocomposite and 500 μl CTAB which display viscosity of 0.043 Pa.s, thermal conductivity of 0.35 Wm−1 K−1, and normalized height % as 1%. Further, the optimal TiO2/ZnO nanofluid is used as working fluid in heat pipe and compared its results with ethylene glycol. From the calculated thermal resistance and heat transfer coefficient values, the TiO2/ZnO nanofluid outperforms the base fluid in a significant manner.

Enhancement of ultrasound assisted aqueous extraction of polyphenols from waste fruit peel using dimethyl sulfoxide as surfactant: Assessment of kinetic models

Pomegranate peel, a major waste from the food processing industries containing biologically active compounds, could be converted into value-added products having medicinal properties. Present study deals with the ultrasound-assisted surfactant, namely dimethyl sulfoxide (DMSO) aided polyphenolics extraction from pomegranate peel waste using double distilled water (DDW) as a solvent. Maximum total yield of extraction and total polyphenolic content (TPC) were found respectively to be 43.58 ± 1.0 and 49.55 ± 0.8%, at optimized sonication parameters viz. temperature 50 °C, power density 1.2 W/mL and time 40 min followed by surfactant aided extraction under optimum conditions 0.6% DMSO, 50 °C and 150 rpm for 90 min. Kinetic models were developed to determine the polyphenolics concentration and validated. GC-MS analysis of the extract revealed 22 phenolic compounds. Thus, the acquired results have ensured the significance of ultrasound pre-treated surfactant aided extraction of polyphenolic compounds and this process can be developed for commercial production.

Enhanced photocatalysis and anticancer activity of green hydrothermal synthesized Ag@TiO2 nanoparticles

Titanium dioxide (TiO₂) nanoparticles (NPs) have been doped with varying amounts (0.005, 0.010 and 0.015 M) of silver nanoparticles (Ag NPs) using hydrothermal method. Further, in this work, a green approach was followed for the formation of Ag@TiO₂ NPs using Aloe vera gel as a capping and reducing agent. The structural property confirmed the presence of anatase phase TiO₂. Increased peak intensity was observed while increasing the Ag concentration. Further, the morphological and optical properties have been studied, which confirmed the effective photocatalytic behavior of the prepared Ag@TiO₂ NPs. The photocatalytic performance of Ag@TiO₂ has been considered for the degradation of picric acid in the visible light region. The concentration at 0.010 M of the prepared Ag@TiO₂ has achieved higher photocatalytic performance within 50 min, which could be attributed to its morphological behavior. Similarly, anticancer activity against lung cancer cell lines (A549) was also determined. The Ag@TiO₂ NPs generated a large quantity of reactive oxygen species (ROS), resulting in complete cancer cell growth suppression after their systemic in vitro administration. Ag@TiO₂ NPs was adsorbed visible light that leads to an enhanced anticancer sensitivity by killing and inhibiting cancer cell reproduction through cell viability assay test. It was clear that 0.015 M of Ag@TiO₂ NPs were highly effective against human lung cancer cell lines and showed increased production of ROS in cancer cell lines due to the medicinal behavior of the Aloe vera gel.

Thermo-chemo-sonic pre-digestion of waste activated sludge for yeast cultivation to extract lipids for biodiesel production

The low cost biosynthesis of microbial lipids are an efficient feedstock to replace plant based oil for biodiesel production. The present study objective is to explore the effect of thermo-chemo-sonic pre-digestion of municipal Waste Activated Sludge (WAS) to cultivate oleaginous L. starkeyi MTCC-1400 as a model organism to produce high yield biomass and lipid. Higher Suspended Solids (SS) reduction (20 and 15.71%) and Chemical Oxygen Demand (COD) solubilization (27.6 and 22.3%) were achieved at a Specific Energy (SE) input of 5569 kJ/kg for WAS digested with NaOH and KOH, respectively. The maximum biomass of 17.52 g L^-1 and lipid 64.3% dwt were attained in NaOH pre-digested sample. The analyzed lipid profile exhibited high content of palmitic acid (45.6%) and oleic acid (38.7%) which are more suitable for biofuel production. Thus, these results strongly motivate the use of pre-digested WAS as an efficient and economical substrate for biodiesel production.

Biomass production of multipopulation microalgae in open air pond for biofuel potential

Biodiesel gains attention as it is made from renewable resources and has considerable environmental benefits. The present investigation has focused on large scale cultivation of multipopulation microalgae in open air pond using natural sea water without any additional nutritive supplements for low cost biomass production as a possible source of biofuel in large scale. Open air algal pond attained average chlorophyll concentration of 11.01 µg/L with the maximum of 43.65 µg/L as well as a higher lipid concentration of 18% (w/w) with lipid content 9.3 mg/L on the 10th day of the culture; and maximum biomass of 0.36 g/L on the 7th day of the culture. Composition analysis of fatty acid methyl ester (FAME) was performed by gas chromatography and mass spectrometry (GCMS). Multipopulation of algal biomass had 18% of total lipid content with 55% of total saturated fatty acids (SFA), 35.3% of monounsaturated fatty acids (MUFA) and 9.7% of polyunsaturated fatty acids (PUFA), revealing a potential source of biofuel production at low cost.

Thermal performance of ethylene glycol based nanofluids in an electronic heat sink

Heat transfer in electronic devices such as micro processors and power converters is much essential to keep these devices cool for the better functioning of the systems. Air cooled heat sinks are not able to remove the high heat flux produced by the today's electronic components. Liquids work better than air in removing heat. Thermal conductivity which is the most essential property of any heat transfer fluid can be enhanced by adding nano scale solid particles which possess higher thermal conductivity than the liquids. In this work the convective heat transfer and pressure drop characteristics of the water/ethylene glycol mixture based nanofluids consisting of Al2O3, CuO nanoparticles with a volume concentration of 0.1% are studied experimentally in a rectangular channel heat sink. The nano particles are characterized using Scanning Electron Microscope and the nannofluids are prepared by using an ultrasonic vibrator and Sodium Lauryl Salt surfactant. The experimental results showed that nanofluids of 0.1% volume concentration give higher convective heat transfer coefficient values than the plain water/ethylene glycol mixture which is prepared in the volume ratio of 70:30. There is no much penalty in the pressure drop values due to the inclusion of nano particles in the water/ethylene glycol mixture.

Ethyl 7-oxo-3,5-diphenyl-1,4-diazepane-2-carboxyl-ate

The title compound, C₂₀H₂₂N₂O₃, crystallizes with two independent mol­ecules in the asymmetric unit. In both mol­ecules, the diazepane rings adopt chair conformations. The mean planes of the diazepane rings in the two molecules form dihedral angles of 71.6 (4)/40.3 (5) and 75.9 (5)/58.6 (7)° with the neighbouring benzene rings. The carbonyl-group O atoms deviate significantly from the diazepane rings, by 0.685 (14) and 0.498 (13) Å. The eth­oxy­carbonyl groups show conformational difference between two mol­ecules, as reflected in the orientation of the carbonyl O atoms and the C—C—O—C torsion angle of −179.0 (2)° in one mol­ecule and 73.2 (2)° in the other. In one molecule there is a short N—H⋯O contact that generates an S(5) ring motif. In the crystal, N—H⋯O inter­actions generate R₂²(8) graph-set motifs and C—H⋯O inter­actions generate R₂²(10) and R₂²(14) graph-set motifs. C—H⋯π inter­actions also occur.

Ethyl 2-(7-oxo-3,5-diphenyl-1,4-diazepan-2-yl)acetate

In the title compound, C21H24N2O3, the diazepane ring adopts a chair conformation. The central diazepane ring forms dihedral angles 67.80 (7) and 72.29 (5)° with the two benzene rings. The ethoxycarbonyl group is disordered over two conformations with site-occupancy factors of 0.643 (5) and 0.357 (5). In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generateR22(8) loops.

Neuroprotective potential of ethanolic extract of Pseudarthria viscida (L) Wight and Arn against beta-amyloid(25-35)-induced amnesia in mice

The neuroprotective potential of ethanolic extract of roots of Pseudarthria viscida (L) Wight and Arn (EEPV) was investigated against beta-amyloid(25-35)-induced amnesia in mice which is a suitable animal model for Alzheimer's disease (AD). The senile plaques of beta-amyloid (Abeta) are major constituents accumulated during the progression of AD as a potent neurotoxicant. In our investigation, intracerebroventricular injection of Abeta(25-35) in mice induced the neurodegeneration, exhibited the increased time of escape latency in behavioral pattern using water maze and decreased the levels of antioxidants namley superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and vitamin C with elevated level of acetylcholinesterase enzyme (AChE). The neuroprotective potential of EEPV was determined by behavioral pattern using water maze and biochemical parameters such as SOD, CAT and GPx and vitamin C content as well as AChE. Mice were treated with EEPV at 200 and 400 mg/kg doses for 21 days. Except control, all animals received a single injection of neurotoxicant Abeta(25-35) on 14th day. In behavioural assessment, treatment with ethanolic extract improved the cognitive function in the water maze and attenuated the elevated levels of AChE with increase in antioxidant enzymes, indicating the neuroprotection with increased levels of vitamin C. These findings suggest that ethanolic extract of P. viscida exerts anti-amnesiac effects and enhances cognitive function.

3,5-Bis(Phenylmethylene)-1-(N-arylmaleamoyl)-4-piperidones: A Novel Group of Cytotoxic Agents

A series of novel 3,5-bis(phenylmethylene)-1-(N-arylmaleamoyl)-4-piperidones 3 have been synthesized which displayed potent cytotoxicity towards human Molt 4/C8 and CEM T-lymphocytes as well as murine P388 and L1210 leukemic cells. In contrast, the related N-arylmaleamic acids 4 possessed little or no cytotoxicity in these four screens. Molecular modeling revealed certain interplanar and bond angles and interatomic distances which were perceived to contribute to the observed bioactivity as well as providing suggestions for future structural modifications of the piperidones 3. Evaluation of representative compounds in series 3 and 4 on the activity of human N-myristoyltransferase revealed that, at the maximum concentration utilized, namely 250 microM, only weak inhibiting properties were displayed by some of the compounds in series 4. Various members of series 3 and 4 were well tolerated in mice.

Cytotoxic and Topographical Properties of 6-Arylidene-2-dimethylaminomethylcyclohexanone Hydrochlorides and Related Compounds

A number of 2-arylidenecyclohexanones (1a-h) were converted into the corresponding Mannich bases (2a-h) and (3a,f). Evaluation against murine L1210 cells as well as human Molt 4/C8 and CEM T-lymphocytes revealed the marked cytotoxicity of the Mannich bases and also the fact that almost invariably these compounds were more potent than the precursor enones (1a-h). Further evaluation of most of the Mannich bases towards a panel of nearly 60 human tumour cell lines confirmed their utility as potent cytotoxins. In this assay, the compounds showed growth-inhibiting properties greater than the anticancer alkylator melphalan. QSAR studies revealed that in some cell lines compounds possessing small electron-attracting aryl substituents showed the greatest potencies. Molecular modeling and X-ray crystallography demonstrated that various interatomic distances and torsion angles correlated with cytotoxicity. A representative compound (2a) demonstrated weak inhibiting properties towards human N-myristoyltransferase and stimulated a tyrosine protein kinase. A single dose of 100 mg/kg of most of the compounds did not prove to be lethal in mice.

Cytotoxic mannich bases of 1-arylidene-2-tetralones

Various 1-arylidene-2-tetralones 1 had been shown previously to possess moderate cytotoxic properties unaccompanied by murine toxicity. The objective of the present investigation was to undertake different molecular modifications of representative members of series 1 with a view to discerning those structural features leading to increased potencies. All compounds were evaluated using human Molt 4/C8 and CEM T-lymphocytes as well as murine P388 and L1210 leukemic cells. The Mannich bases 2, 4, 5 and 7 possessed increased potencies compared to the corresponding unsaturated ketones 1 and in general were potent cytotoxics having IC50 values in the 0.2-10 microM range. QSAR using the cytotoxicity data for 2a-e suggested that potency was positively correlated with the size of the substituents in the arylidene aryl ring. Compounds 2a-f were evaluated using a panel of approximately 53 human tumour cell lines and, when all cell lines were considered, were more potent than the reference drug melphalan. In particular, marked antileukemic activity was displayed. Molecular modeling was utilized in order to evaluate whether the shapes of the different compounds contributed to the varying potencies observed. Representative compounds demonstrated minimal or no inhibiting properties towards human N-myristoyltransferase (NMT) and did not bind to calf thymus DNA. This study has revealed a number of unique lead molecules as candidate anti-neoplastic agents serving as prototypes for future development.

An unusual case of patella dislocation

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Recent developments in microbial inulinases. Its production, properties, and industrial applications

Microbial inulinases are an important class of industrial enzymes that have gained much attention recently. Inulinases can be produced by a host of microorganisms, including fungi, yeast, and bacteria. Among them, however, Aspergillus sp. (filamentous fungus) and Kluyveromyces sp. (diploid yeast) are apparently the preferred choices for commercial applications. Among various substrates (carbon source) employed for their production, inulin-containing plant materials offer advantages in comparison to pure substrates. Although submerged fermentation has been universally used as the technique of fermentation, attempts are being made to develop solid-state fermentation technology also. Inulinases catalyze the hydrolysis of inulin to D-fructose (fructose syrup), which has gained an important place in human diets today. In addition, inulinases are finding other newer applications. This article reviews more recent developments, especially those made in the past decade, on microbial inulinases--its production using various microorganisms and substrates. It also describes the characteristics of various forms of inulinases produced as well as their applications.

Purification and characterization of glucoamylase produced by Aspergillus niger in solid state fermentation

Glucoamylases produced by Aspergillus niger grown on wheat brain in solid cultures were purified. Four different forms, GA I, GA I', GA II and GA III, were found having apparent molecular weights of 112,000, 104,000, and 74,000 and 61,000 Da respectively. The enzymes are glycoproteins with a carbohydrate content of 16%, and optimal activity at 60 degrees C and pH 4.4. Activity was strongly inhibited by Hg2+ while Mn2+ and Fe2+ were stimulatory. The Km values for the degradation of starch and maltose were 3.5 and 7.8 mg ml-1, respectively.

Pulmonary cavitatory tuberculosis in children

This study was undertaken to analyse children with pulmonary cavitatory tuberculosis which is a rare and infectious condition. The pretreatment characteristics, course and response to three different anti-tuberculous regimes in 27 children with cavitary pulmonary lesions registered at the TB Clinic, Institute of Child Health, are described. Male:Female ratio was 1.2:4. Thirty per cent of affected children were below 3 years of age and had predominant lower lobe involvement whereas in older children the upper lobes were affected. Eighty five per cent of children had definite history of contact with an adult with tuberculosis. Tuberculin test was positive in 70% of children. Cavitary lesion were observed in the right lung in 66% of cases. Follow up and surveillance was carried out in 23 children who completed the anti tuberculous treatment. Regimes with isoniazid, rifampicin, pyrazinamide and streptomycin were given to different groups. Response and compliance was also monitored. Eleven out of 23 children had persistence of radiological lesions even after completion of 9 months of therapy. Inclusion of streptomycin with 2 or 3 bactericidal drugs in the intensive phase showed a better response.