Synthesis and characterization of magnetic bifunctional nano-catalyst for the production of biodiesel from Madhuca indica oil.

The reusable magnetic multimetal nano-catalyst (Fe3O4.Cs2O) was synthesized using co-precipitation and incipient wetness impregnation methods. It was used to esterify and transesterify Madhuca indica (M. indica) oil to produce biodiesel with methanol. The prepared catalyst, caesium oxide doped on the nano-magnetite core, was characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Further, the activity of the catalyst was investigated by subjecting it to a biodiesel reaction. To maximize biodiesel conversion, studies were carried out by varying the process variables like catalyst concentration, methanol-to-oil molar ratio, reaction temperature, and reaction time. A maximum conversion of 97.4% was obtained at the holding conditions of 18:1 methanol-to-oil ratio, 7 wt% catalyst loading, 65 °C reaction temperature, and 300 min reaction time. Moreover, the catalyst recyclability study showed that it could be recycled up to 12 cycles with a conversion of 90% and above. The biodiesel's fuel properties were analysed and found to be within the limits of ASTM D6751 standard.

Kinetic studies on the extraction of oil from a new feedstock (Chukrasia tabularis L. seed) for biodiesel production using a heterogeneous catalyst.

This study has identified a new feedstock Chukrasia tabularis L. (C. tabularis) seed for the production of biodiesel. Oil was extracted from the seeds with and without autoclave-assisted ultrasonic homogenization (AUH) pretreatment using different solvents. The solvent n-hexane with AUH pretreatment yielded a maximum oil yield of 32 wt%. The kinetics and thermodynamics of the extraction process were studied in a batch. The data showed that extraction followed first-order kinetics with a rate constant of 1.4 × 10-4 min-1, activation energy of 63.604 kJ mol-1 and pre-exponential factors of 66.66 × 104 s-1. The physiochemical properties of the oil were determined from which it was identified that C. tabularis oil has high free fatty acid (FFA) content, requiring a single-step esterification cum transesterification reaction to produce biodiesel economically. The modified aryl diazonium salt reduction process was used to synthesize a heterogeneous acid catalyst (HAC) from activated carbon precursor and was used to catalyze biodiesel reaction. Furthermore, HAC was characterized by different analytical techniques and it was found that it had an acid site density of 1.02 mmol g-1 and a specific surface area of 602 m2 g-1. The parameters affecting the biodiesel process were studied to obtain a maximum biodiesel conversion of 98.5% at 6 wt% catalyst loading, 15:1 methanol to oil molar ratio, 120 min reaction time, 70 ºC reaction temperature, and 500 rpm stirring rate. Reusability studies were performed which showed that HAC can be recycled up to five cycles with a conversion above 90% in the fifth cycle. Moreover, the fuel properties of biodiesel were determined using standard methods and were compared with ASTM D6751 and EN14241 standards.

Synthesis of Boron-Doped Zinc Oxide Nanosheets by Using Phyllanthus Emblica Leaf Extract: A Sustainable Environmental Applications.

The use of Phyllanthus emblica (gooseberry) leaf extract to synthesize Boron-doped zinc oxide nanosheets (B-doped ZnO-NSs) is deliberated in this article. Scanning electron microscopy (SEM) shows a network of synthesized nanosheets randomly aligned side by side in a B-doped ZnO (15 wt% B) sample. The thickness of B-doped ZnO-NSs is in the range of 20-80 nm. B-doped ZnO-NSs were tested against both gram-positive and gram-negative bacterial strains including Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli. Against gram-negative bacterium (K. pneumonia and E. coli), B-doped ZnO displays enhanced antibacterial activity with 26 and 24 mm of inhibition zone, respectively. The mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), mean free path (MFP), half-value layer (HVL), and tenth value layer (TVL) of B-doped ZnO were investigated as aspects linked to radiation shielding. These observations were carried out by using a PTW® electron detector and VARIAN® irradiation with 6 MeV electrons. The results of these experiments can be used to learn more about the radiation shielding properties of B-doped ZnO nanostructures.

Isolation, mass cultivation, and biodiesel production potential of marine microalgae identified from Bay of Bengal.

In this study, marine microalgae were isolated from the Bay of Bengal, and their biodiesel production potential was investigated. Five different strains of microalgae were identified, viz. Nannochloropsis salina (N. salina), Dunaliella salina (D. salina), Chaetoceros calcitrans (C. calcitrans), Tetraselmis chuii (T. chuii), and Euglena sanguinea (E. sanguinea). Further, these stains were mass cultivated in a 250-L bioreactor to assess their biomass production ability. At the end of the exponential phase, algal biomass was harvested for lipid extraction. The fatty acid profile and physico-chemical properties of the lipids were analyzed. It was observed that a maximum of 27.67wt% of lipid was obtained for N. salina followed by D. salina (22.58 wt%), E. sanguinea (21.88 wt%), T. chuii (20.15 wt%), and C. calcitrans (16.25 wt%). Subsequently, the extracted lipids were subjected to single-step esterification and transesterification process to produce biodiesel by using an acid catalyst. The different parameters influencing the reaction such as catalyst concentration, temperature, methanol to lipid molar ratio, and time were investigated. A maximum biodiesel yield of 97, 94, 96, 92, and 92 wt% were obtained for N. salina, D. salina, C. calcitrans, T. chuii, and E. sanguinea, respectively, at the favorable reaction conditions. The fuel properties of biodiesel were analyzed as per the standard protocol and compared with ASTM D6751 standard.

Role of cytochrome P450 genes of Trichoderma atroviride T23 on the resistance and degradation of dichlorvos.

The Trichoderma has been extensively used to degrade the xenobiotics. In the present study, thirty-nine open reading frames of cytochrome P450 genes from T. atroviride T23 genome was cloned and it was found to be distributed in 29 families under 21 clades. Among them, 21 cytochrome P450 genes were involved in the degradation of xenobiotics. The quantitative expression of P450 genes in the presence of dichlorvos at 24 h showed 7 different expression patterns in the presence of 100 µg/mL, 300 µg/mL, 500 µg/mL and 1000 µg/mL of dichlorvos. The relative expression of P450 genes belongs to the family of TaCyp548, TaCyp620, TaCyp52, TaCyp528, TaCyp504 were upregulated at least 1-fold compared to the control. Significantly, the deletion of TaCyp548-2 reduced the concentration of 2,2-dichloroethanol. Further, it was observed that TaCyp548-2 belongs to the ω-hydroxylase family was responsible for fatty acid oxidation and the production of acetic acid, propionic acid, isobutyric acid and dibutyric acid to convert the 2,2-dichloroethanol to 2,2-dichloroethanolacetate. This study evidenced the involvement of Trichoderma P450 genes on dichlorvos degradation as an environmentally significant Biological control agent for the sustainable agriculture.

Chitin derivatives of NAG and chitosan nanoparticles from marine disposal yards and their use for economically feasible fish feed development.

Globally, the disposal of shellfishery waste is a major challenge and causes a risk to the coastal region. For potential development in aquaculture, the use of safe supplements to improve fish production and health is important. Chitosan (CS) used as feed additives for several fish species that enhanced production and immunity. The present study was intended to assess the effect of feed additives N-acetyl-d-glucosamine (NAG) loaded chitosan nanoparticles (CSNPs) on productivity, survival rate, and protein conversion efficiency of Oreochromis niloticus (L.). This is the first report on the effect of CSNPs and NAG loaded CSNPs as feed additives enhanced growth performance and non-specific immunity of O. niloticus. CSNPs and NAG loaded CSNPs were synthesized and characterized by scanning and transmission electron microscope, FT-IR, X-ray diffraction, particle size distribution, and zeta sizer. Fish (15.30 ± 0.23 g) administered diets fortified with 0.0, 0.25, 0.5, 1.0, and 2.0 g CSNPs/kg feed loaded with NAG for 45 d. The diets containing 1.0 g/kg NAG loaded CSNPs enhanced specific growth rate, weight gain, survival rate, respiratory burst, and lysozyme activities of tilapia compared control group. The data shows biologically active CSNPs and NAG loaded CSNPs are potent antimicrobial agents against selected bacterial pathogens. In conclusion, the findings suggested that the dietary supplement containing NAG loaded CSNPs significantly increased immune-modulatory properties, growth performance, and enhanced their disease resistance of Nile tilapia.

Use of Nanocellulose extracted from grass for adsorption abatement of Ciprofloxacin and Diclofenac removal with phyto, and fish toxicity studies.

The present study deals with the adsorption of antibiotic Ciprofloxacin (CPXO) and anti-inflammatory agent Diclofenac (DCF) on Grass nanocellulose (GNC) extracted from Cyprus rotundas grass. The adsorbent GNC was characterised using various microscopic, elemental and spectroscopic analysis to monitor the physicochemical alterations of the surface before and after adsorption. The size of the converted nanocellulose was found to be 40-50 nm. The experimental measures influencing the adsorption of CPXO and DCF that were optimised are initial solution pH, GNC dosage, temperature and initial concentration of the adsorbate. Halsey isotherm model and pseudo-second order kinetic model agreed best with the experimental outcome for both the adsorbate. The maximum adsorption capacity of GNC were 227.223 and 192.307 mg/g for CPXO and DCF respectively. Phytotoxicity studies were performed using 6 different types of seeds to evaluate the effect of GNC treated effluent on plants. Similarly, acute fish toxicity on zebra fish analysis showed to have lesser mortality rate of the effluent after adsorption of CPXO and DCF on GNC.

Porcine versus bovine bioprosthetic valves in mitral position: does choice really matter?

BACKGROUND: Bioprosthetic valves are increasingly used for surgical mitral valve replacement (MVR). The long-term outcomes of bovine (BoMVR) vs porcine (PoMVR) remain an enigma regarding the durability. This study aims to examine the outcomes of BoMVR vs PoMVR. METHODS: A retrospective analysis of all bioprosthetic MVRs, with concomitant procedures, at a single tertiary referral institution from January 2005 to December 2008 was conducted. Procedures were classified as BoMVR or PoMVR. The age group was from 40 to 70 years. RESULTS: We identified 154 BoMVR patients and 120 PoMVR patients after matching the two groups with respect to age, sex, valve size and concomitant procedures. Kaplan-Meier survival analysis model was used for corresponding statistical analysis. Freedom from reoperation (all cause), freedom from non-structural valve deterioration, freedom from structural valve deterioration, freedom from heart failure and freedom from infective endocarditis were 96.4 ± 0.08, 97.1 ± 0.07, 96.4 ± 0.08%, 98.2 ± 0.07, and 98.6 ± 0.06% in PoMVR, respectively, and 92.6 ± 0.09, 91.6 ± 0.08, 90.6 ± 0.09, 94 ± 0.08, and 92.8 ± 0.08% in BoMVR groups, respectively, at the end of 10-year follow-up (mean follow up of 6.2 ± 2.3 years). Overall, 20 (12.9%) patients were lost to follow-up in the BoMVR and 15(12.5%) patients in the PoMVR groups for a global follow-up of 87.1%. CONCLUSIONS: For patients undergoing MVR with a bioprosthetic valve, the choice of PoMVR vs BoMVR favours more in favour of PoMVR as evidenced by the outcome results. Probably long-term follow-up with more patients might throw further light on the debatable topic.

Nano-sulfated zirconia catalyzed biodiesel production from tannery waste sheep fat.

This study makes use of tannery waste to produce biodiesel using a nano-sulfated zirconia catalyst (ferric-manganese-doped sulfated zirconia). It was through a modified wetness impregnation method that the catalyst was prepared which was then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The catalytic property of the synthesized catalyst was determined by using it to produce biodiesel from tannery waste sheep fat. A study was carried out to find the effect of the different parameters affecting the process. Optimized conditions of 15:1 methanol to fat molar ratio and catalytic loading of 8 wt% at 65 °C with a stirring rate of 400 rpm for a reaction duration of 300 min gave a maximum yield of 98.7 wt%. The performance of the catalyst during recycling was analyzed by conducting reusability study. The reused catalyst gives a maximum yield above 90 wt% up to five cycles with a catalyst recovery of 88 wt%. ASTM D6751 standard was used to compare the analyzed fuel properties of the biodiesel.

Conversion of a low value industrial waste into biodiesel using a catalyst derived from brewery waste: An activation and deactivation kinetic study.

In this study, biodiesel was produced by using a heterogeneous acid catalyst made from brewer's spent yeast (BSY). BSY was initially activated by phosphoric acid followed by carbonization in inert atmosphere and sulfonation process to prepare the catalyst. It is completely characterized using sophisticated instruments to determine its physical and chemical properties. Subsequently, the effectiveness of the catalyst was analyzed by subjecting it to sonochemical esterification of an industrial low value waste product, palm fatty acid distillate (PFAD). The reactions were performed in the presence of ultrasound at a constant frequency of 25 kHz. An optimum methyl ester conversion of 87.8% was achieved at 8 wt% of catalyst, 21:1 methanol to PFAD molar ratio, 65 °C and 180 min of reaction time. The catalyst displayed a high catalytic stability up to four cycles due to firm SO3H functional group attached onto the surface. Furthermore, a novel sonochemical kinetic model was proposed for surface esterification reaction on the catalyst. The reaction rate was found and it followed a pseudo-first-order reaction mechanism. Furthermore, a deactivation model was also proposed to account for the loss of activity upon catalyst reuse during sonochemical reaction.

Infected Teflon felt strip-paracardiac abscess after Dor's procedure.

Foreign material used for reconstructing or suturing the cardiac chambers carries the risk of infection. When such a scenario is encountered, it is better to be aggressive in removing the infected source surgically, as conservative management will most often result in recurrence. Herein, we present an unusual case of infected prosthetic material after cardiac surgery that was managed surgically. This case reminds us of the surgical principle of eradicating the source of infection, which should be given priority.

A rare presentation of intrapericardial hematoma 20 months post aortic valve replacement.

We report the successful treatment of a rare case of chronic intrapericardial hematoma which presented with congestive cardiac failure 20 months after aortic valve replacement surgery for severe calcific aortic stenosis. Chest roentgenograph demonstrated paracardiac mass over lower left ventricle border, left pleural effusion and pulmonary venous hypertension. An echocardiographic study demonstrated intrapericardial mass posterolateral to left ventricle compressing left ventricular cavity both during systole and diastole causing septum to bulge into right ventricle. Computed tomography showed a loculated pericardial mass in left heart margin, left pleural effusion, bilateral axillary and mediastinal lymphadenopathy. Surgical resection was planned to relieve the symptoms and to confirm the diagnosis of the mass. The mass was completely resected through left anterolateral thoracotomy and histopathology findings confirmed the diagnosis of hematoma with cystic degeneration. Postoperative course was uneventful, and his symptoms improved markedly.