Comparison of the effect of different medicaments on surface reproduction of two commercially available Polyvinyl Siloxane impression materials: an Invitro Study

Objective:To determine the effect of different retraction cord medicaments on surface detail reproduction of polyvinyl siloxane impression materials and compare this effect on any two brands of commercially available polyvinyl siloxane impression materials. Material and methods: Four stainless steel dies were made according to ADA specification no.19. Three dies were treated with aluminium chloride (5%), ferric sulphate (13.3%) and epinephrine (0.1%) while the fourth one was left untreated to serve as control. Two impression materials (Dentsply and 3M ESPE) were used. Results: All the three medicaments adversely affected the surface detail reproduction of both the brands of the polyvinyl siloxane impression materials. These effects were statistically significant as compared to untreated control. The impressions of 3M ESPE brand have shown better surface detail reproduction as compared to Dentsply impression material. Conclusion: Surface detail reproduction of the polyvinyl siloxane impression materials is adversely affected by the retraction cord medicaments. The presence of moisture or any traces of the medicaments should be removed from the tooth surface to provide a dry field for the correct reproduction of the surface detail of these material

Tribological characterization of eco-designed aluminium hybrid metal matrix composites

47-57In present experimental investigation, wear characteristics of Al 7075-T6/Eggshell/SiC/Al2O3 hybrid composites (Al 7075-T6 as base metal with eggshell particles wt. % 0.5, 1and 1.5, average particle size ~ 60 µm, SiC particles wt. % 1, 1.5 and 2, average particle size ~ 65 µm and Al2O3 particles wt. % 1.5, 2 and 2.5, average particle size ~90 µm) synthesized through electromagnetic stir casting route have been studied at various specimen temperatures under dry and lubricated test conditions. Wear investigations have been conducted on pin-on-disk rotary tribometer at a constant load of 20 N for a sliding speed of 2m/s and sliding distance of 2 km. Tribological attributes of synthesized composites have been evaluated as the function of reinforcements content and mechanical stirring time, as per the design of experiment according to Taguchi L9 orthogonal array. Experimental study has shown that at 30 ºC pin temperature under dry wear condition, among the developed hybrid composites, specimen S8 demonstrated a maximum relative decrease of 60% in wear loss while with lubrication the wear loss has been relatively decreased by 89% as compared to the base metal (specimen S0). At elevated pin temperature of 70 ºC under dry wear condition, the hybrid composite specimen S8 exhibited maximum relative reduction of 82% in wear loss whereas under lubricated condition the wear loss has been relatively reduced by 82% in comparison of their unreinforced counterpart (specimen S0). With exceedingly augmented tribological attributes, the current study strongly rationalizes high temperature wear resistant applications of synthesized aluminium hybrid composites with a total reinforcement weight percentage of 4.5% only (specimen S8).

Effect of integrated nutrient management on sequential productivity, economics and nutrient uptake of rice (Oryza sativa) - potato (Solanum tuberosum) cropping sequence

A field experiment was conducted at Banaras Hindu University, Varanasi, Uttar Pradesh during 2010-12 to evaluate the effect of nine different combinations of integrated plant nutrient supply including 3 different type of composts prepared from carpet waste generated in huge amount from carpet industry, farmyard manure and compared with the recommended dose of NPK (120:60:60 kg/ha) through inorganic fertilizer on productivity, economics, energetic, nutrient uptake and soil health of rice (Oryza sativa L.) - potato (Solanum tuberosum L.) cropping sequence. Bioinoculants such as cellulose decomposers (Trichoderma viride, Pleurotus sajor), P-solubilizing microbes (Bacillus polymyxa) and free living N-fixers (Azotobacter spp), essential nutrients, i.e. S and Zn were used as compost culture to hasten the composting process and improve the quality of the composts. The results indicated that net energy return (260 033.2 Rupees/ha), rice grain equivalent yield and nutrient uptake was significantly (P < 0.05) higher under recommended dose of NPK compared to the rest of the treatments but statistically similar with 75% RN through inorganic fertilizer and 25% N through carpet waste + cow dung slurry + Pleurotus sajor + Azotobacter + PSB + Trichoderma + enriched with S and Zn (251 886 Rupees/ha). The soil fertility status was found to be significantly improved due to application of various composts compared to sole application of 100% NPK inorganic fertilizer. Thus, substitution of chemical Nfertilizer to the tune of 25% nitrogen through carpet waste + cow dung slurry + Pleurotus sajor + Azotobacter + PSB + Trichoderma + Enrichment with S and Zn increased productivity and profitability in rice-potato cropping sequence with better soil health on long term basis

Use of different coloured ovitraps in the surveillance of Aedes mosquitoes in an arid-urban area of western Rajasthan, India

Background & objectives: In the absence of any commercially available dengue vaccine or antiviral therapy, controlling the primary mosquito vector, Aedes aegypti, is currently the only means to prevent dengue outbreaks. Ovitraps are being employed as a sensitive method for detecting the presence of Ae. aegypti. Size, colour, material, paddle and use of oviposition attractant have been reported as important factors influencing the efficacy of ovitraps. Methods: For the study of coloured ovitraps baited with grass infusion, 24 households were randomly selected in a locality and five ovitraps/premises were installed. Weekly ovitrap surveys were conducted during the study for four times. Ovitrap data were analyzed on the basis of its location, day-wise percent positivity, presence of eggs laid and inference of different ovitrap parameters were drawn. Results: Grass infusion, used in the ovitraps has highest attractiveness on Day 6 in comparison to other days. Percent positivity of different coloured ovitraps revealed that red coloured ovitraps have highest positivity (92.7%), followed by black and orange (91.7% each), green (76.3%) and transparent (45.8%). The individual colour-wise ovitrap positivity revealed that the highest ovitrap positivity on Day 1 was recorded for black colour (21.8%), which on D2 and D3, in case of red colour (37.5 and 26%). However, on D4, D5 and D6 highest number of positive ovitraps was recorded in orange coloured (12.5, 21.9 and 31.3%, respectively) and on D7 highest number of positive ovitraps were recorded in transparent (21.9%), followed by green coloured ovitrap (20.8%). The overall location-wise ovitraps positivity revealed that highest positivity was recorded among the ovitraps installed inside bathrooms (92.0%), followed by bedrooms (85.0%), lobby (66.7%) and stores (48.3%). Interpretation & conclusion: The study revealed that for immediate detection of the presence of gravid females in a particular locality during epidemics, the black coloured ovitraps may be useful, however, in normal situations for surveillance of the vector species, the orange coloured ovitraps might be more suitable. Bathrooms were found to be the highest positive location for pitching ovitraps

Machinability Characterization of Ecodesigned Hybrid Aluminium Composites

Machinability is expressed as the ease with which a material can undergo machining operations with gratifying surface finish and persistent material removal rate. In general, alumiAnium composites are observed to be difficult to machine due to infusion of hard reinforcement particles into metal matrix. In present study, machinability attributes of Al7075-T6/ Eggshell/SiC/Al2O3composites (Al7075-T6 as matrix material infused with three reinforcement materials: eggshell particles with average particle size ~ 60 µm; wt. % 0.5, 1and 1.5, Silicon Carbide particles with average particle size ~ 65 µm; wt. % 1, 1.5 and 2, and Aluminium Oxide particles with averageparticle size ~90 µm; wt. % 1.5, 2 and 2.5,) synthesized through electromagnetic stir casting route, have been investigated with fixed machining parameters (Cutting speed : 6 m/min, Depth of cut: 1mm, Feed rate: 0.3 mm/second and Test duration: 30 seconds). With enhanced mechanical attributes, the machinability of synthesized aluminium composites was realized to remain uninfluenced in terms of proportionate material removal rate (material removal rate of specimen S8: 0.0040g/sec and of specimen S0: 0.0043g/sec) and comparable surface roughness (average surface roughness of specimen S8: 1.02 μm and of specimen S0: 1.15μm). Disposal of eggshells has been listed worldwide as one of the worst environmental problems, hence eggshell powder has been used as one of the reinforcement in order to synthesize ecodesigned hybrid aluminium composites

Machinability Characterization of Ecodesigned Hybrid Aluminium Composites

252-257Machinability is expressed as the ease with which a material can undergo machining operations with gratifying surface finish and persistent material removal rate. In general, alumiAnium composites are observed to be difficult to machine due to infusion of hard reinforcement particles into metal matrix. In present study, machinability attributes of Al7075-T6/ Eggshell/SiC/Al2O3composites (Al7075-T6 as matrix material infused with three reinforcement materials: eggshell particles with average particle size ~ 60 µm; wt. % 0.5, 1and 1.5, Silicon Carbide particles with average particle size ~ 65 µm; wt. % 1, 1.5 and 2, and Aluminium Oxide particles with averageparticle size ~90 µm; wt. % 1.5, 2 and 2.5,) synthesized through electromagnetic stir casting route, have been investigated with fixed machining parameters (Cutting speed : 6 m/min, Depth of cut: 1mm, Feed rate: 0.3 mm/second and Test duration: 30 seconds). With enhanced mechanical attributes, the machinability of synthesized aluminium composites was realized to remain uninfluenced in terms of proportionate material removal rate (material removal rate of specimen S8: 0.0040g/sec and of specimen S0: 0.0043g/sec) and comparable surface roughness (average surface roughness of specimen S8: 1.02 μm and of specimen S0: 1.15μm). Disposal of eggshells has been listed worldwide as one of the worst environmental problems, hence eggshell powder has been used as one of the reinforcement in order to synthesize ecodesigned hybrid aluminium composites

Squamous cell carcinoma in the anophthalmic socket-a series of 4 cases with HPV-16 profiling

To present the clinical and histological features of squamous cell carcinoma (SCC) in the anophthalmic socket in four adult patients, and to determine the presence of human papillomavirus infection (HPV).Retrospective case series of four adult patients with SCC of the anophthalmic socket. P16 immunohistochemistry and HPV testing was carried out in all cases. The authors report clinical findings, histopathology, management and outcomes for all four\ua0patients with conjunctival SCC. Previously reported cases of conjunctival SCC in anophthalmic sockets were reviewed.Four adult patients presented with eyelid lumps, discharge or change in prosthesis fit. Common examination findings included papillomatous changes, eyelid masses and epithelial changes. Three out of the four cases (75%) were positive for p16 by immunohistochemistry and the same cases positive for HPV-16 DNA. All patients received cryotherapy, topical or intralesional chemotherapy. Two patients proceeded to exenteration for control of invasive disease.To the authors' knowledge, this is the largest series of SCC in the anophthalmic socket with comprehensive annotation of HPV status. Although socket conjunctiva is protected from environmental radiation, there is still a risk of neoplastic transformation in this tissue, thus patient education and regular checking of sockets by ophthalmologists should be undertaken as a preventative measure. The potential role of HPV in these tumours warrants further investigation

Control of the growth of human breast cancer cells in culture by manipulation of arachidonate metabolism

<p>Abstract</p> <p>Background</p> <p>Arachidonate metabolites are important regulators of human breast cancer cells. Production of bioactive lipids are frequently initiated by the enzyme phospholipase A2 which releases arachidonic acid (AA) that is rapidly metabolized by cyclooxygenases (COX) or lipoxygenases (LO) to other highly potent lipids.</p> <p>Methods</p> <p>In this study we screened a number of inhibitors which blocked specific pathways of AA metabolism for their antiproliferative activity on MCF-7 wild type and MCF-7 ADR drug resistant breast cancer cells. The toxicity of these inhibitors was further tested on human bone marrow cell proliferation.</p> <p>Results</p> <p>Inhibitors of LO pathways (specifically the 5-LO pathway) were most effective in blocking proliferation. Inhibitors of platelet activating factor, a byproduct of arachidonate release, were also effective antiproliferative agents. Curcumin, an inhibitor of both COX and LO pathways of eicosanoid metabolism, was 12-fold more effective in blocking proliferation of the MCF-7 ADR^scells compared to MCF-7 wild type (WT) cells. These inhibitors that effectively blocked the proliferation of breast cancer cells showed varying degrees of toxicity to cultures of human bone marrow cells. We observed greater toxicity to bone marrow cells with inhibitors that interfere with the utilization of AA in contrast to those which block utilization of its downstream metabolites. MK-591, MK-886, PCA-4248, and AA-861 blocked proliferation of breast cancer cells but showed no toxicity to bone marrow cells.</p> <p>Conclusion</p> <p>These inhibitors were effective in blocking the proliferation of breast cancer cells and may be potentially useful in human breast cancer therapy.</p