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1.
Chemphyschem ; 25(11): e202300472, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38487944

ABSTRACT

Catalysts with V2O5, WO3 and V2O5-WO3 dispersed over TiO2 were synthesized using sol-gel technique and thoroughly characterized by various techniques. The catalysts were evaluated for degradation of ortho-dichloro benzene (o-DCB) in air/helium, a representative probe molecule for polychlorinated dibenzo-para-dioxin and polychlorinated dibenzofuran by employing in situ Fourier-transform infrared spectroscopy (FT-IR spectroscopy). Different intermediate species formed on the surface of the TiO2 supported catalysts through of interaction of sorbate molecules with the lattice and/or gaseous oxygen were investigated in detail. Analysis of vibrational bands, observed during sorption of o-DCB and o-DCB-air mixture as a function of temperature over these catalysts, delineated the role of surface intermediate species such as phenolate, enolates, maleates, carboxylates, carbonates in mineralization of o-DCB. Nature and stability of intermediate species, found to be different over these catalysts, were able to elucidate the catalytic activity trend.

2.
Anim Biotechnol ; 34(7): 3187-3205, 2023 Dec.
Article in English | MEDLINE | ID: mdl-35713100

ABSTRACT

Continuous improvement in the living standards of developing countries, calls for an urgent need of high quality meat and dairy products. The farm animals have a micro-ecosystem in gastro-intestinal tract, comprising of a wide variety of flora and fauna which converts roughages and agricultural byproducts as well as nutrient rich concentrate sources into the useful products such as volatile fatty acids and microbial crude proteins. The microbial diversity changes according to composition of the feed, host species/breed and host's individual genetic makeup. From culture methods to next-generation sequencing technologies, the knowledge has emerged a lot to know-how of microbial world viz. their identification, enzymatic activities and metabolites which are the keys of ruminant's successful existence. The structural composition of ruminal community revealed through metagenomics can be elaborated by metatranscriptomics and metabolomics through deciphering their functional role in metabolism and their responses to the external and internal stimuli. These highly sophisticated analytical tools have made possible to correlate the differences in the feed efficiency, nutrients utilization and methane emissions to their rumen microbiome. The comprehensively understood rumen microbiome will enhance the knowledge in the fields of animal nutrition, biotechnology and climatology through deciphering the significance of each and every domain of residing microbial entity. The present review undertakes the recent investigations regarding rumen multi-omics viz. taxonomic and functional potential of microbial populations, host-diet-microbiome interactions and correlation with metabolic dynamics.


Subject(s)
Microbiota , Rumen , Animals , Rumen/metabolism , Farms , Multiomics , Diet/veterinary , Animal Feed
3.
Trop Anim Health Prod ; 53(2): 291, 2021 Apr 28.
Article in English | MEDLINE | ID: mdl-33909188

ABSTRACT

The objective of this study was to evaluate the effects of synbiotic formulation of Cichorium intybus root powder (C) with Lactobacillus acidophilus NCDC15 (LA) and Lactobacillus reuteri BFE7 (LR) on growth performance in Murrah buffalo calves via monitoring selective gut health indices. Twenty-four Murrah buffalo calves of 5-7 days old and 33 ± 2.0 kg of body weight were distributed randomly into three groups adopting complete randomized design (CRD) as follows: (1) group I served as control (CON) provided with a basal diet alone; (2) group II supplemented with synbiotic formulation of 200 mL L. acidophilus NCDC15 fermented milk with 8 g of Cichorium intybus root powder (LAC) along with basal diet; (3) group III supplemented with synbiotic formulation of 200 mL L. reuteri BFE7 fermented milk with 8 g of Cichorium intybus root powder (LRC) along with basal diet. The final body weight (BW), average dry matter intake (DMI) and structural body measurements were significantly increased (P < 0.05) in LAC and LRC groups by synbiotic as compared to the CON. No effect was registered on apparent nutrient digestibility coefficient of various nutrients in supplemented groups. Faecal score was reduced by the supplementation of synbiotic being lowest in LRC followed by LAC and CON. Calves supplemented synbiotic showed lower (P < 0.05) faecal pH and ammonia with a concomitant increase in faecal lactate levels and faecal short chain fatty acids (SCFA) as compared to control. The faecal Lactobacillus and Bifidobacterium population was increased (P < 0.05) in synbiotic fed groups as compared to control. Additionally, coliform and clostridia count was decreased (P < 0.05) in treatment groups compared to CON. Overall, it may be concluded that synbiotic supplementation was effective in improving the growth performance in Murrah buffalo calves via altering selective gut health indices.


Subject(s)
Cichorium intybus , Limosilactobacillus reuteri , Synbiotics , Animal Feed/analysis , Animals , Buffaloes , Diet/veterinary , Lactobacillus acidophilus , Powders
4.
Inorg Chem ; 59(17): 12659-12671, 2020 Sep 08.
Article in English | MEDLINE | ID: mdl-32845617

ABSTRACT

The dominant intensity of parity-forbidden intra-4f transitions of europium(III) over O → Eu charge-transfer band (CTB) intensity is against common perceptions, yet this trend is observed in many germanate hosts and has not been rationalized so far. In search of a plausible explanation for this unusual trend, present work reports an experimental and theoretical investigations in conjunction on two sibling germanate host, namely, Y2GeO5 and Y2Ge2O7 having dopant Eu3+ in their respective YO7 polyhedra. Whereas for Y2GeO5:Eu3+, the CTB is more intense than the intra-4f transitions in the excitation spectrum, in the case of Y2Ge2O7:Eu3+, the relative intensities of CTB and intra-4f transitions are reversed. Comparative structural analysis reveals that Eu3+ present in YO7 of Y2GeO5 has a greater number of tetra-coordinated oxygen (Otetra) and yttrium atom as first and second neighbors, respectively (Eu3+-Otetra-Y3+ linkages). Conversely, in Y2Ge2O7 host, the Eu3+ ion mostly has tricoordinated oxygen (Otri) as its nearest neighbor and germanium ions next to Otri (Eu3+-Otri-Ge4+ linkage). Theoretical calculations reveal that while Y2GeO5:Eu has Otetra(4Y) dominating at the Fermi level and the 4f state of Eu3+ remains inert toward mixing, in Y2Ge2O7:Eu, the Fermi level has major contribution from Otri(2Y + 1Ge) with significant mixing with 4f states of Eu. The dominant control of Eu3+-Otri-Ge4+ linkages in geometrical and electronic structure of Y2Ge2O7:Eu owing to the GeO4 surrounding has been attributed to relative poor intensity of O → Eu CTB. Siege of Eu3+ by GeO4 and subsequent occurrence of Eu3+-Otri-Ge4+ linkages play a dual role: First, it induces electronic rigidity to hinder excitation of electron at bridging (Otri) oxygen by highly charged small Ge4+ cation; second, the covalent character in Eu-O bond is achieved by intermixing of Eu's 4f and Otri 2p orbital which facilitates relaxing of the parity-selection rule thus enhancing the probability of intra-4f transitions. The inferences drawn remain valid when extrapolated to other inorganic oxides having EuOx polyhedra surrounded by covalent units like PO4, SiO4, etc. and have a prevailing number of low-coordinated oxygen atoms and highly charged small cation in the first and second coordination shells, respectively. The optical basicity concept is also found to endorse our explanation. These remarkable generic inferences will pave the rational way for designing efficient phosphors for solid-state lighting.

5.
Med J Armed Forces India ; 75(4): 444-449, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31719740

ABSTRACT

BACKGROUND: Among the multitudinous etiologies of pancreatitis, primary hyperparathyroidism (PHPT) is rarely associated with pancreatitis. However, the cause and effect relationship between the two still evokes controversy. We aimed to study and characterize the nature of pancreatic disease in PHPT. METHODS: A retrospective single-center study was carried out in North India over a period of 1 year (June 2015 to May 2016). All patients with pancreatitis were included. In patients with high calcium levels, Intact Parathyroid Hormone (iPTH) by Radioimmunoassay (RIA) and an Technetium 99m Sestamibi scintigraphy (MIBI-Tc-99m) scan were performed. RESULTS: During the study period, 70 patients with pancreatitis were admitted to our hospital (53 with acute pancreatitis [AP] and 17 with chronic pancreatitis [CP]). Of them, 5 patients (9.4%) were detected to have PHPT. The mean age of patients was 30.4 years (20-49 years) with 3 males and 2 females, including 1 pregnant female (29th week of gestation). Contrast enhanced computed tomography (CECT) abdomen was performed in 4 cases (excluding 1 pregnant patient) with mean Computed tomography severity index (CTSI) of 4.7 (2-8). Four patients were detected to have increased uptake in one of the parathyroid glands, and the fifth patient had an ectopic parathyroid uptake in the mediastinum. All the resected samples were identified as parathyroid adenoma on histology. The patients were followed up for 1 year with no reported recurrence of symptoms. CONCLUSION: The data suggest an association between pancreatitis (both acute and chronic) and hypercalcemia due to PHPT. A high calcium value during AP or CP should always draw suspicion and warrants corresponding investigations in search of endocrine or malignant cause.

6.
Acta Neurochir (Wien) ; 160(4): 793-800, 2018 04.
Article in English | MEDLINE | ID: mdl-29188366

ABSTRACT

INTRODUCTION: The neutrophil-lymphocyte count ratio (NLCR) is an established prognostic marker for renal, lung and colorectal carcinomas and has been suggested to be predictive of histological grade and outcome in adult intracranial tumours. The purpose of this study was to determine whether a correlation of the pre-operative neutrophil count (NC) and NLCR with the final histological grade exists in paediatric intracranial tumours. METHODS: A retrospective analysis was undertaken at a single centre. Patients less than 18 years old at the time of surgery who underwent tumour-related procedures from 2006 to 2015 were included. Patients with recurrent tumours, previous bone marrow transplant and metastases were excluded. Pre-operative full blood counts (FBC), collected before the diagnosis of intracranial pathology and before administration of steroids, were matched with histological diagnosis for each patient. Post-operative FBC was also recorded, together with survival data where applicable. RESULTS: A total of 116 patients (74 male, 42 female; mean age, 8 ± 0.9 years) with a diagnosis of primary intracranial tumours had pre-operative FBC that could be matched to final histological grade. Pre-operative NC and NLCR were higher with increasing grade of tumour: grade 1 (NC 4.29 109/l, NLCR 2.26), grade 2 (NC 4.59 109/l, NLCR 2.38), grade 3 (NC 5.67 109/l, NLCR 2.72) and grade 4 (NC 6.59 109/l, NLCR 3.31). Patients with WHO grade 1 and 2 tumours pooled together had a lower NC (4.37 95% CI ± 0.67 109/l) compared to WHO grade 3 and 4 patients (6.41 95% CI ± 0.99 109/l, p = 0.0013). The NLCR was lower in grade 1 and 2 tumours (2.29 ± 0.59) (compared to grade 3 and 4 tumours; 3.20 ± 0.76) but this did not reach significance (p = 0.069). The subgroup of patients with pilocytic astrocytoma had a significantly lower NC when compared to patients with high-grade tumours (p = 0.005). Medulloblastoma and supratentorial PNET subgroups had significantly higher NC compared to the low-grade group (p = 0.033, p = 0.002). Post-operative NC was significantly higher in the high-grade tumours (p = 0.034), but no difference was observed for NLCR (p = 0.28). CONCLUSIONS: No evidence exists to support the correlation of pre-operative NC or NLCR to histological diagnosis in paediatric intracranial tumours. Our results indicate that a higher pre-operative NC/NLCR correlates with a higher histological grade of tumour. This suggests that immunological mechanisms may be involved in the pathogenesis of paediatric brain tumours, and a further prospective study is required to substantiate and expand these findings.


Subject(s)
Astrocytoma/blood , Brain Neoplasms/blood , Cerebellar Neoplasms/blood , Medulloblastoma/blood , Neoplasm Recurrence, Local/blood , Adolescent , Astrocytoma/epidemiology , Astrocytoma/pathology , Brain Neoplasms/epidemiology , Brain Neoplasms/pathology , Cerebellar Neoplasms/epidemiology , Cerebellar Neoplasms/pathology , Child , Child, Preschool , Female , Humans , Leukocyte Count , Male , Medulloblastoma/epidemiology , Medulloblastoma/pathology , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/pathology
7.
J Anim Physiol Anim Nutr (Berl) ; 102(3): 679-689, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29493022

ABSTRACT

A study of 120 days was undertaken to ascertain the effect of mannan-oligosaccharides (MOS) and Lactobacillus acidophilus supplementation on growth performance, nutrient utilization and faecal characteristics in Murrah buffalo calves. Twenty Murrah buffalo calves of 5-7 days old and 31 ± 2.0 kg of body weight (BW) were randomly assigned into four groups. Group I served as the control (CON) in which only basal diet (concentrate mixture and green fodder) was provided, without any supplementation. Mannan-oligosaccharides at 4 g/calf/day were supplemented as prebiotic to Group II (PRE), whereas Group III (PRO) received Lactobacillus acidophilus in the form of fermented milk as probiotic at 200 ml/calf/day having 108  CFU/ml and Group IV (SYN) was supplemented with both MOS and Lactobacillus acidophilus as synbiotic at similar dose. Final BW (kg), dry matter intake, average daily gain, feed conversion efficiency and structural growth measurements were improved (p < .05) in the treatment groups compared to control. Digestibility of neutral detergent fibre was higher (p < .05) in SYN followed by PRE and PRO than control. The faecal lactobacilli and bifidobacterium population was higher (p < .05) in all the supplemented groups with a concomitant reduction in faecal coliform count as compared to control. Faecal ammonia, lactate and pH were also altered favourably (p < .05) in all the supplemented groups as compared to CON. The faecal volatile fatty acids were higher (p < .05) in PRE, PRO and SYN group than CON. The incorporation of MOS and Lactobacillus acidophilus in diet either individually or in combination as synbiotic has the potential to improve the performance and faecal characteristics in Murrah buffalo calves; however, the observed responses among the treatment groups were more evident in the synbiotic fed group compared to individual supplementation of MOS and Lactobacillus acidophilus.


Subject(s)
Buffaloes/physiology , Dietary Supplements , Feces/chemistry , Lactobacillus acidophilus , Mannans/chemistry , Animal Feed/analysis , Animal Nutritional Physiological Phenomena , Animals , Diet/veterinary , Digestion , Fermentation , Milk , Probiotics
8.
Phys Chem Chem Phys ; 18(32): 22160-7, 2016 Aug 10.
Article in English | MEDLINE | ID: mdl-27445041

ABSTRACT

Defects in planar and vertically oriented nanographitic structures (NGSs) synthesized by plasma enhanced chemical vapor deposition (PECVD) have been investigated using Raman and X-ray photoelectron spectroscopy. While Raman spectra reveal the dominance of vacancy and boundary type defects respectively in vertical and planar NGSs, XPS provides additional information on vacancy related defect peaks in the C 1s spectrum, which originate from non-conjugated carbon atoms in the hexagonal lattice. Although an excellent correlation prevails between these two techniques, our results show that estimation of surface defects by XPS is more accurate than Raman analysis. Nuances of these techniques are discussed in the context of assessing defects in nanographitic structures.

9.
J Nanosci Nanotechnol ; 15(4): 2804-9, 2015 Apr.
Article in English | MEDLINE | ID: mdl-26353496

ABSTRACT

1D nanostructures of ZnO, Zn0.95Co0.05O and Zn0.85Co0.05Li0.10 were synthesized by a solvothermal chemical method with and without using oleic acid as a stabilizer. We report a very interesting observation of both room temperature ferromagnetism and photoluminescence properties along with development of different morphological transformation of these nanostructures on doping Co and Li in ZnO in the presence and absence of oleic acid. Zn0.95Co0.05O sample prepared in the presence of oleic acid showed increased saturation magnetization value (~ 4.1 emu/g and) compared to Zn0.95Co0.05O prepared without oleic acid (~ 1.1 emu/g). In both the cases it is observed that Li incorporation further enhances the room temperature ferromagnetic (RTFM) behavior and saturation magnetization values (~ 6 emu/g) of luminescent Zn0.95Co0.05 nanostructures. These results are significant, as the luminescent 1 D RTFM materials will have implications in photo magnetic devices like magneto-optical switches and sensors.


Subject(s)
Cobalt/chemistry , Lithium/chemistry , Nanostructures/chemistry , Zinc Oxide/chemistry , Luminescent Agents/chemistry , Nanotechnology , Particle Size , X-Ray Diffraction
10.
Pharmacogenomics J ; 14(3): 263-71, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24165757

ABSTRACT

Cytochrome P450 enzymes (CYPs) and flavin-containing monooxygenases (FMOs) likely have a role in the oxidation of intermediate metabolites of busulfan (Bu). In vitro studies to investigate the involvement of these enzymes are cumbersome because of the volatile nature of the intermediate metabolite tetrahydrothiophene (THT) and the lack of sensitive quantitation methods. This study explored the association between the CYP2C9, CYP2C19, CYP2B6 and FMO3 genotypes and sulfolane (Su, a water soluble metabolite of Bu) plasma levels in children undergoing hematopoietic stem cell transplantation (HSCT). The relationship between these genotypes and the effectiveness of myeloablative conditioning was also analyzed. Sixty-six children receiving an intravenous Bu-based myeloablative conditioning regimen were genotyped for common functional variant alleles in CYP2C9 (*2 and *3), CYP2C19 (*2 and *17), FMO3 (rs2266780, rs2266782 and rs1736557) and CYP2B6 (*5 and *9). The plasma levels of Bu and its metabolite Su were measured after the ninth Bu dose in a subset of 44 patients for whom plasma samples were available. The ratio of Bu to Su was considered the metabolic ratio (MR) and was compared across the genotype groups. Higher MRs were observed in CYP2C9*2 and *3 allele carriers (mean±s.d.: 7.8±3.6 in carriers vs 4.4±2.2 in non-carriers; P=0.003). An increased incidence of graft failure was observed among patients with an MR>5 compared with those with MR values <5 (20% vs 0%; P=0.02). In contrast, a significantly higher incidence of relapse and graft failure (evaluated as event-free survival) was observed in patients with malignant disease who carried CYP2B6 alleles with reduced function on both chromosomes compared with carriers of at least one normal allele (100% vs 40%; P=0.0001). These results suggest that CYP2C9 has a role in the oxidation reactions of THT and indicate that it may be possible to predict the efficacy of Bu-based myeloablative conditioning before HSCT on the basis of CYP genotypes and Bu MRs.


Subject(s)
Antineoplastic Agents, Alkylating/therapeutic use , Busulfan/therapeutic use , Cytochrome P-450 Enzyme System/genetics , Hematopoietic Stem Cell Transplantation , Polymorphism, Genetic , Thiophenes/metabolism , Transplantation Conditioning , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male
11.
Opt Lett ; 39(11): 3086-9, 2014 Jun 01.
Article in English | MEDLINE | ID: mdl-24875983

ABSTRACT

This Letter reports on nanomechanical and optical properties of yttrium thin films deposited on an Si (100) wafer. Elemental depth profiling by a secondary ion mass spectrometer revealed absence of formation of yttrium hydride, both on the surface and beneath. The optical properties were investigated by spectroscopic ellipsometry, and the refractive indices extracted after suitable modeling were found to be 2.51 at 546 nm. Hardness and elastic modulus of these films were found to be 7 and 142 GPa, respectively. These studies indicate that yttrium thin films are suitable for x-ray mirrors, photocathode emitters in e-beam lithography, electron microscopes, and free-electron lasers.

12.
Phys Chem Chem Phys ; 16(48): 27065-73, 2014 Dec 28.
Article in English | MEDLINE | ID: mdl-25383891

ABSTRACT

To investigate the variation in the radiation stability of ceria with microstructure under the electronic excitation regime, ceria samples sintered under different conditions were irradiated with high energy 100 MeV Ag ions. The ceria nanopowders were synthesized and sintered at 800 °C (S800), 1000 °C (S1000) and 1300 °C (S1300), respectively. The samples with widely varying grain size, densities and microstructure were obtained. The pristine and irradiated samples were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). None of the samples amorphized up to the highest fluence of 1 × 10(14) ions per cm(2) employed in this study. XRD and Raman studies showed that the sample with lowest grain size suffered maximum damage while the sample with largest grain size was most stable and showed little change in crystallinity. Raman spectroscopy indicated the enhanced formation of Ce(3+) and related defects in the sample with larger grain size after irradiation. The most intriguing result was the absence of Ce(3+)-related defects in the sample with lowest grain size which actually showed maximum damage upon irradiation. The XPS studies on S800 and S1300 provided concrete evidence for the presence of Ce(3+) and oxygen ion vacancies in S1300. The grain boundaries and grain size dependent stability have been discussed.

14.
Med J Armed Forces India ; 70(3): 230-6, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25378775

ABSTRACT

BACKGROUND: Contrast enhanced ultrasound (CEUS) has recently gained widespread acceptance as an adjunct to conventional grey scale ultrasound. The present pilot study was undertaken to evaluate the efficacy of this technique in characterisation of hepatic focal lesions. METHODS: Adult patients who had at least one focal liver lesion underwent ultrasound evaluation in regular and contrast mode before and after intravenous administration of sulphur hexafluoride. The diagnoses were confirmed by comparison with a reference standard (multidetector CT), response to treatment or pathological correlation. RESULTS: The rate of correct diagnosis for unenhanced ultrasound was 54%, CEUS was 72% and multidetector CT (MDCT) was 92%. A comparison of unenhanced ultrasound versus CEUS using the McNemar test yielded a p value of 0.0704 (>0.05). However, comparison of CEUS versus MDCT using the McNemar test yielded a p value of 0.0265 (<0.05). Additionally, comparison of unenhanced ultrasound versus MDCT using the McNemar test yielded a p value of <0.0001. CONCLUSION: CEUS increases diagnostic efficacy over unenhanced ultrasound but does not have any significant advantages over MDCT. Currently it may be used as a problem solving tool in atypical haemangiomas, echogenic focal liver lesions, contrast sensitivity and to avoid multiple studies utilising ionising radiation.

15.
Br J Neurosurg ; 27(4): 413-8, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23281683

ABSTRACT

PURPOSE: To know the occurrence and distribution of Pilomyxoid Astrocytomas amongst tumours previously diagnosed histologically as Pilocytic Astrocytoma and to assess the clinical impact of this new entity. METHODS: Retrospective Diagnostic review of all cases histologically diagnosed as WHO Grade I Astrocytoma at a single Neurosurgical unit between 1990 and 2003. RESULTS: Of a total of 91 cases identified, 9 were found to have Pilomyxoid histology. Of these, 8 were children (mean age 3.33 years) and 1 adult. 6 tumours were hypothalamochiasmatic in location. The clinical course of Pilomyxoid tumours was aggressive marked by maturation, multiple recurrences and disease control was rarely achieved with single treatment modality as opposed to typical pilocytics. The overall survival of the pilomyxoid group was not statistically different from the pilocytic tumours. CONCLUSIONS: Encompassing all age-groups and locations, Pilomyxoid Astrocytomas constitute about 10% of all tumours previously diagnosed as Pilocytic Astrocytoma. Nearly two-thirds are hypothalamo-chiasmatic in location. Knowledge of this entity is essential for appropriate aggressive treatment and follow-up.


Subject(s)
Astrocytoma/pathology , Hypothalamic Neoplasms/pathology , Mucus , Optic Nerve Neoplasms/pathology , Adolescent , Adult , Aged , Astrocytoma/classification , Astrocytoma/epidemiology , Astrocytoma/mortality , Child , Child, Preschool , Female , Humans , Hypothalamic Neoplasms/epidemiology , Hypothalamic Neoplasms/mortality , Incidence , Infant , Magnetic Resonance Imaging , Male , Middle Aged , Neoplasm Grading , Neoplasm Recurrence, Local , Neoplasm Staging , Optic Nerve Neoplasms/epidemiology , Optic Nerve Neoplasms/mortality , Retrospective Studies , Young Adult
16.
Nano Lett ; 12(6): 3025-30, 2012 Jun 13.
Article in English | MEDLINE | ID: mdl-22545916

ABSTRACT

The development of methods to economically synthesize single wire structured multiferroic systems with room temperature spin-charge coupling is expected to be important for building next-generation multifunctional devices with ultralow power consumption. We demonstrate the fabrication of a single nanowire multiferroic system, a new geometry, exhibiting room temperature magnetodielectric coupling. A coaxial nanotube/nanowire heterostructure of barium titanate (BaTiO(3), BTO) and cobalt (Co) has been synthesized using a template-assisted method. Room temperature ferromagnetism and ferroelectricity were exhibited by this coaxial system, indicating the coexistence of more than one ferroic interaction in this composite system.


Subject(s)
Barium Compounds/chemistry , Crystallization/methods , Nanotubes, Carbon/chemistry , Titanium/chemistry , Barium Compounds/radiation effects , Electric Impedance , Magnetic Fields , Materials Testing , Nanotubes, Carbon/radiation effects , Titanium/radiation effects
17.
J Mech Behav Biomed Mater ; 138: 105582, 2023 02.
Article in English | MEDLINE | ID: mdl-36459704

ABSTRACT

Ankle-foot orthotics need ideal specification of being light-weight, high strength, tough, stiff, and durable. Reinforced polypropylene (PP) composites with enhanced mechanical properties are the most favorable materials being used in this field, but still, it is challenging to achieve balanced blend of strength and toughness in the composites. The present study thus aims to achieve the challenging task of simultaneous improvement in stiffness and toughness in reinforced PP composites exploring the synergistic reinforcement effect of glass fibers (GFs) and nano silica (SiO2) as multiscale fillers and ethylene propylene diene monomer (EPDM) as impact modifier. EPDM is used as toughness modifier, addressing the brittle behavior, but at the cost of the strength of the polymer. Combined use of micro and nanofillers as reinforcement in toughened polypropylene provides a potential approach to balance the strength while maintaining the toughness. GFs could offer high strength and nanofillers offer ductile fracture to the material. PP, PP/GF, PP/EPDM/GF composites and PP/EPDM/GF/SiO2 nanocomposites are fabricated through melt blending technique and are characterized through SEM, mechanical evaluation, nanoindentation and dynamic mechanical analysis. Mechanical properties are evaluated in accordance with ASTM standards. PP/EPDM/GF/SiO2 nanocomposites exhibits remarkable enhancement in Tensile strength, tensile modulus, impact strength and percent elongation at break by 49 MPa (55% increase over PP), 2450 MPa (145% increase), 145 J/m (13% increase) and 156% (160% increase) respectively. The exceptional improvement in reduced modulus and hardness reveals good interfacial properties. Loss factor decrement reveals elastic behavior of nanocomposites suitable for thermoforming of nanocomposites for orthotic device fabrication.


Subject(s)
Nanocomposites , Silicon Dioxide , Polypropylenes , Materials Testing , Ethylenes
18.
Dalton Trans ; 52(4): 1036-1051, 2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36602081

ABSTRACT

Herein, using in situ generated solvated electrons in the reaction media, a highly time-efficient, one-pot green approach has been employed to synthesize palladium (Pd) nanoparticles (NPs) coated with a molecular assembly of α-cyclodextrin (α-CD). The appearance of a shoulder peak at 280 nm in the UV-Vis absorption spectra indicated the formation of Pd NPs, which was further confirmed from their cubic phase XRD pattern. The nanomorphology varied considerably as a function of the dose rate, wherein sphere-shaped NPs (average size ∼ 7.6 nm) were formed in the case of high dose rate electron-beam assisted synthesis, while nanoflakes self-assembled to form nanoflower-shaped morphologies in a γ-ray mediated approach involving a low dose rate. The formation kinetics of NPs was investigated by pulse radiolysis which revealed the formation of Pd-based transients by the solvated electron-induced reaction. Importantly, no interference of α-CD was observed in the kinetics of the transient species, rather it played the role of a morphology directing agent in addition to a biocompatible stabilizing agent. The catalytic studies revealed that the morphology of the NPs has a significant effect on the reduction efficiency of 4-nitrophenol to 4-aminophenol. Another important highlight of this work is the demonstration of the morphology-dependent anticancer efficacy of Pd NPs against lung and brain cancer cells. Notably, flower-shaped Pd NPs exhibited significantly higher cancer cell killing as compared to spherical NPs, while being less toxic towards normal lung fibroblasts. Nonetheless, these findings show the promising potential of Pd NPs in anticancer treatment.


Subject(s)
Cyclodextrins , Metal Nanoparticles , Palladium , Electrons , Catalysis
19.
Analyst ; 137(3): 760-4, 2012 Feb 07.
Article in English | MEDLINE | ID: mdl-22171323

ABSTRACT

Lead metal ions are of great concern and the monitoring of their concentration in the environment has become extremely important. In the present study, a new inorganic-organic hybrid assay of Ag nanorods (AgNR)-Rhodamine 6G (R6G) was developed for the sensitive and selective determination of Pb(2+) ions in aqueous solutions. To the best of our knowledge there is almost no literature on the use of silver nanorod sensors for determination of lead ions in aqueous solutions. The sensor is developed by the coating of R6G on the surface of AgNRs. The sensing is based on the photoluminescence of R6G. The sensor was rapid as the measurements were carried out within 3 min of addition of the test solution to the AgNR-R6G hybrid. Moreover, the system showed excellent stability at tested concentration levels of Pb(2+) ions. The naked eye detection of the colour was possible with 1 mg L(-1) of Pb(2+) ions. The present method has a detection limit of 50 µg L(-1) of Pb(2+) (for a signal/noise (S/N) ratio > 3). The selectivity toward Pb(2+) ions against other metal ions was improved using chelating agents. The proposed method was validated by analysis using different techniques.

20.
Med Mycol ; 49(2): 167-71, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20718608

ABSTRACT

Studies on Pneumocystis jirovecii dihydropteroate synthase (DHPS) genotypes among non-HIV immunocompromised patients from developing countries are rare. In the present prospective investigation, 24 (11.8%) cases were found to be positive for Pneumocystis jirovecii out of 203 non-HIV patients with a clinical suspicion of Pneumocystis pneumonia (PCP). Dihydropteroate synthase (DHPS) genotype 1 (Thr55+Pro57) was noted in 95.8% P. jirovecii isolates in the present study in contrast to only 4.1% of patients with DHPS genotype 4 (Thr55Ala + Pro57Ser).


Subject(s)
Dihydropteroate Synthase/genetics , Immunocompromised Host , Pneumocystis carinii/enzymology , Pneumonia, Pneumocystis/microbiology , Adolescent , Adult , Amino Acid Substitution/genetics , Child , Child, Preschool , Female , Genotype , Hospitals , Humans , Infant , Male , Middle Aged , Pneumocystis carinii/genetics , Pneumocystis carinii/isolation & purification , Prospective Studies , Young Adult
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