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1.
Sci Total Environ ; 873: 162402, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36841404

ABSTRACT

It has been shown that vegetal species constitute an alternative natural source for the biosynthesis of new nanomaterials. Thus, aiming to expand knowledge about the potential use of plants in the fabrication of metallic nanomaterials, we aimed to synthesize silver nanoparticles (AgNPs) from phyto-formulation (PF) of ten commonly used medicinal plants. Our results demonstrate the formation of spherical, stable, polycrystalline AgNPs with a diameter of 8.42 nm to 18.40 nm, whose biosynthesis confirmation was performed via UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM)-energy dispersive X-ray spectroscopy (EDS) mapping, high-resolution transmission electron microscopy (HR-TEM), dynamic light scattering (DLS), and zeta potential studies. Furthermore, we demonstrated that the biosynthesized AgNPs showed larvicidal activity against Aedes aegypti and Anopheles stephensi larvae, with the histopathology findings from the fourth instar larval stage validating such larvicidal toxicity. The histological examinations showed severe degradation of the larvae's hindgut, epithelial cells, midgut, and cortical area. However, the PF extract and the biosynthesized AgNPs showed high ecotoxicity in Danio rerio larvae exposed to different concentrations. The treatments induced changes in hatchability percentage, animal growth, and heartbeat. Therefore, despite supporting the potential of PF (from ten plant species) as a raw material source for AgNPs biosynthesis, our study also sheds light on its ecotoxicological potential, suggesting that more comprehensive assessments of the ecotoxicity of biosynthesized would be performed before its application in different sectors.


Subject(s)
Culex , Insecticides , Metal Nanoparticles , Plants, Medicinal , Animals , Metal Nanoparticles/toxicity , Metal Nanoparticles/chemistry , Silver/chemistry , Spectroscopy, Fourier Transform Infrared , Plant Extracts/chemistry , Larva/metabolism , Plant Leaves/chemistry , Insecticides/metabolism
2.
Materwiss Werksttech ; 53(1): 119-127, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35465100

ABSTRACT

Challenges in the development of carbon fibre and graphene reinforced composite polylactic acid material is reserved in this research. A screw extrusion process is used to blend the carbon fibre particle (1 wt.%) and graphene (1 wt.%) with poly lactic acid pellets (98 wt.%) to extrude and draw a continuous composite poly lactic acid wire. The size of the wire drawn is 1.75 mm and it is found uniform in shape. Through electron microscope, the dispersion of carbon fibre and graphene in the polylactic acid material is confirmed with good bonding. Subsequently, the presence of carbon fibre and graphene reinforcement in polylactic acid material is confirmed through the x-ray diffraction peaks. The composite polylactic acid material developed through screw extrusion is to build a mechanical test sample. The strength of composite polylactic acid material is 31 MPa and 3D printed composite polylactic acid material is 63 MPa. The density of the composite material is found increased in 3D printed material than the raw polylactic acid material. With valid mechanical and thermal properties of composite polylactic acid material, a commercial product is developed. An autoclavable COVID -19 face shield is designed and developed through Fused filament fabrication 3D printer and the same was implemented.

3.
Technol Health Care ; 29(6): 1339-1353, 2021.
Article in English | MEDLINE | ID: mdl-34092680

ABSTRACT

BACKGROUND: Soccer is one of the world's most successful sports with several players. Quality player's activity management is a tough job for administrators to consider in the Internet of Things (IoT) platform. Candidates need to predict the position, intensity, and path of the shot to look back on their results and determine the stronger against low shot and blocker capacities. OBJECTIVE: In this paper, the IoT-assisted wearable device for activity prediction (IoT-WAP) model has been proposed for predicting the activity of soccer players. METHOD: The accelerometer built wearable devices formulates the impacts of multiple target attempts from the prevailing foot activity model that reflect a soccer player's characteristics. The deep learning technique is developed to predict players' various actions for identifying multiple targets from the differentiated input data compared to conventional strategies. The Artificial Neural Network determines a football athlete's total abilities based on football activities like transfer, kick, run, sprint, and dribbling. RESULTS: The experimental results show that the suggested system has been validated from football datasets and enhances the accuracy ratio of 97.63%, a sensitivity ratio of 96.32%, and a specificity ratio of 93.33% to predict soccer players' various activities.


Subject(s)
Athletic Performance , Internet of Things , Soccer , Wearable Electronic Devices , Humans
4.
J Hosp Infect ; 112: 87-91, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33812940

ABSTRACT

To determine the variation in practices on meticillin-resistant Staphylococcus aureus (MRSA) surveillance and management of MRSA-colonized patients amongst 17 acute healthcare facilities in Singapore, the Ministry of Health convened a sharing session with Infection Prevention and Control Leads. All hospitals practised close to universal MRSA entry swabbing in keeping with national policy. There were, however, major variations in the response to both positive and negative surveillance swabs across facilities including the role of routine antiseptic bathing and MRSA decolonization. Most undertaking decolonization considered its role to be in 'bioburden reduction' rather than longer-term clearance.


Subject(s)
Anti-Infective Agents, Local , Cross Infection , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Baths , Carrier State/prevention & control , Cross Infection/prevention & control , Hospitals , Humans , Infection Control , Singapore , Staphylococcal Infections/prevention & control
5.
Eur Phys J Plus ; 136(1): 116, 2021.
Article in English | MEDLINE | ID: mdl-33500872

ABSTRACT

ABSTRACT: A sequence of Bi2O3 varying barium-zincborate (BZX) glasses with the chemical composition (60-x) B2O3-20ZnO-20BaCO3-xBi2O3-0.5Dy2O3 (where x = 0, 5, 10, 15, 20, 25, and 30 in wt%) is fabricated by melt-quenching method. The fabricated samples were examined for the variation in physical, structural, elastic, and radiation-shielding properties with the Bi2O3 concentration. The structural and compositional evaluations are done using XRD and FTIR spectra. The BZX matrixes consist of the trigonal-planar and tetrahedral groups of borates, BiO3 and BiO6 units of Bi2O3, and the non-bridging oxygen in general. The average single-bond strength values substantiate the increasing ionic nature of the BZX glasses. The variation in the density and molar volume of the BZX series discussed in terms of various structural and elastic properties. The glass-coded BZ15 was found to be the best candidate for the sound-resistant applications based on the atomic packing fraction and the acoustic impedance studies. With MCNP5 simulation, the mass attenuation coefficient (MAC) values of all the samples were calculated and compared with a theoretical approach using the XCOM program. As the amount of Bi2O3 increases, the linear attenuation coefficient (LAC) increases with it at all energies. The LAC values varied between 0.2805 and 0.5269 cm-1 for the investigated glasses at 0.81 MeV. BZ30 glass is the more effective shield due to the highest MAC and LAC values.

6.
Mar Pollut Bull ; 158: 111443, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32753221

ABSTRACT

The present study was performed to analyze the bioaccumulation of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes in the crab Scylla serrata from different regions of Tuticorin, Southeast Coast of India. The study area consists of Threspuram and Harbour Beach which were polluted environments due to the discharge of industrial effluents and domestic sewage into them. Punnakayal, which is a low-polluted environment where the in-situ culture of S. serrata is carried out by local fish farmers, was selected as well. The results revealed that the level of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes were significantly high in the crabs collected from Threspuram and Harbour Beach compared to the crabs collected from Punnakayal. This study indicates that crabs from polluted environments have significant heavy metals bioaccumulation which leads to elevated antioxidants and metabolic enzyme levels. This implies that the crabs are under oxidative and metabolic stress.


Subject(s)
Brachyura , Metals, Heavy , Water Pollutants, Chemical/analysis , Animals , Antioxidants , Bioaccumulation , India
8.
J Hosp Infect ; 102(3): 267-276, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30529703

ABSTRACT

BACKGROUND: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. AIM: To determine the time-trend of SSI rates in surveillance networks. METHODS: SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. FINDINGS: Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. CONCLUSION: In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.


Subject(s)
Epidemiological Monitoring , Infection Control/methods , International Cooperation , Surgical Wound Infection/epidemiology , Surgical Wound Infection/prevention & control , Asia/epidemiology , Australia/epidemiology , Europe/epidemiology , Humans , Incidence , Retrospective Studies
9.
Article in English | MEDLINE | ID: mdl-30564309

ABSTRACT

Background: Endoscopy related infections represent an important threat for healthcare systems worldwide. Recent outbreaks of infections with multidrug resistant micro-organisms have highlighted the problems of contaminated endoscopes. Endoscopes at highest risk for contamination have intricate mechanisms, multiple internal channels and narrow lumens that are especially problematic to clean. In light of raised awareness about the necessity for meticulous reprocessing of all types of endoscopes, a call for international collaboration is needed. An overview is presented on current practices for endoscope reprocessing in facilities worldwide. Method: An electronic survey was developed and disseminated by the International Society for Antimicrobials and Chemotherapy. The survey consisted of 50 questions aimed at assessing the reprocessing of flexible endoscopes internationally. It covered three core elements: stakeholder involvement, assessment of perceived risks, and reprocessing process. Results: The survey received a total of 165 completed responses from 39 countries. It is evident that most facilities, 82% (n = 136), have a standard operating procedure. There is, however a lot of variation within the flexible endoscope reprocessing practices observed. The need for regular training and education of reprocessing practitioners were identified by 50% (n = 83) of the respondents as main concerns that need to be addressed in order to increase patient safety in endoscope reprocessing procedures. Conclusion: This international survey on current flexible endoscope reprocessing identified a large variation for reprocessing practices among different health care facilities/countries. A standardised education and training programme with a competency assessment is essential to prevent reprocessing lapses and improve patient safety.


Subject(s)
Endoscopes/microbiology , Endoscopy/education , Endoscopy/standards , Equipment Contamination , Cross Infection/prevention & control , Disinfection/standards , Endoscopy/adverse effects , Endoscopy/economics , Humans , Infection Control/methods , Quality Assurance, Health Care , Risk Factors
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 204: 537-547, 2018 Nov 05.
Article in English | MEDLINE | ID: mdl-29975916

ABSTRACT

In the present work, the structural and optical properties of borotellurite glasses co-doped with Dy3+ ions and Ag nanoparticles were investigated. From HR-TEM analysis, the average Ag nanoparticle diameter was calculated as 13.7 ±â€¯1 nm. The negative sign of the bonding parameter explored the ionic nature of metal-ligand (DyO) bonds. The emission spectra exhibited three emission bands in blue, yellow and red regions corresponding to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions, respectively. The Yellow/Blue (Y/B) ratio of optimal BTD0.5A glass was found to be 1.881 and this low Y/B ratio indicated the fact that Dy3+ ions were located in higher symmetrical ligand environment. The CCT values are found to vary from 3717 to 3800 K and hence the present glasses may emit cool white light when excited with UV lamp. The radiative parameters were calculated for all the emission transitions by using JO theory. The decay curves are found to show non-exponential behavior for all the studied glasses. The obtained results were discussed in detail and compared with similar reported glasses.

11.
Spectrochim Acta A Mol Biomol Spectrosc ; 193: 422-431, 2018 Mar 15.
Article in English | MEDLINE | ID: mdl-29277073

ABSTRACT

A new series of Dy3+ doped (30-x)B2O3+30TeO2+20CaCO3+10ZnO+10ZnF2+xDy2O3 (x=0.01, 0.1, 0.5, 1, 2 and 3 in wt%) Zinc calcium tellurofluoroborate glasses were prepared and their structural, luminescence and excited state dynamics have been studied and reported. The structural properties have been characterized through XRD and FTIR studies to confirm the amorphous nature and to explore the presence of fundamental stretching vibrations. The bonding parameters (δ and ß), optical band gap, Urbach's energy, oscillator strengths and Judd-Ofelt (JO) intensity parameters were calculated from the absorption spectra. The JO intensity parameters and the Y/B intensity ratio values have been used to explore the nature of the bonding and asymmetry around the Dy-ligand field environment. The luminescence properties of the present Dy3+ doped glasses have been analyzed through luminescence excited state dynamics and radiative properties such as transition probability (A), stimulated emission cross-section (σPE) branching ratio (ß) and radiative lifetime (τR) values. The combination of dominant blue (4F9/2→6H15/2) and yellow (4F9/2→6H13/2) emissions generates white light emission in the CIE chromaticity diagram thus suggests that the present Dy3+ doped glasses are suitable for white light applications. The lifetime of the 4F9/2 excited state is found to decrease with the increase in Dy3+ ion content and the concentration quenching of the Dy3+ ions emission could be ascribed due to the resonant energy transfer and cross-relaxation processes. The non-exponential behavior of the decay curves has been analyzed with Inokuti-Hirayama model and the interaction between the Dy3+ ions is of electric dipole-dipole in nature.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 185: 139-148, 2017 Oct 05.
Article in English | MEDLINE | ID: mdl-28558322

ABSTRACT

A new series of Sm3+ doped alkaliborate glasses have been prepared by melt quenching technique and their structural and spectroscopic properties were analysed employing XRD, FTIR, optical absorption, photoluminescence and decay spectral measurements in order to explore their suitability for photonic applications. The amorphous nature have been confirmed through XRD analysis and the FTIR spectra reveal the presence of fundamental stretching and bending vibrations of the borate networks in the prepared glasses. From the absorption peak positions, bonding parameter (δ) values were calculated to examine the nature of the metal-ligand bond. The optical band gap (Eopt) corresponds to the direct and indirect allowed transitions and the Urbach energies (ΔE) were calculated from the absorption spectra to understand the electronic band structure of the studied glasses. The Judd-Ofelt (JO) intensity parameters Ωλ (λ=2, 4 and 6) were determined to explore the symmetry of the ligand environment around the Sm3+ ions in the studied glasses. The luminescence spectra exhibit four emission bands in the visible region due to the 4G5/2→6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions. The radiative parameters such as transition probability (A), stimulated emission cross-section (σPE), branching ratios (ßR) and radiative lifetime (τR) have been determined from the luminescence spectra using JO theory to ensure the suitability of the studied glasses for optoelectronic applications. The luminescence spectra were characterized through CIE 1931 chromaticity diagram to examine the dominant emission color of the studied glasses. The lifetime values of the Sm3+ doped studied glasses pertaining to the 4G5/2 excited level have been determined through decay curve measurements and the non-exponential decay curves were fitted to the Inokuti-Hirayama model to analyze the energy transfer mechanism between the nearby Sm3+ ions. The obtained results were discussed and compared with the similar reported glasses.

13.
J Fluoresc ; 26(6): 2281-2294, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27604297

ABSTRACT

The effect of electronegativity and ion size of the modifier cations have been analyzed through a new series of Dy3+ doped telluroborate glasses prepared by melt quenching technique with the composition of 30TeO2 + 29.5B2O3 + 20MO + 20MF2 + 0.5Dy2O3 (where M = Ba2+, Sr2+, Zn2+, Cd2+ and Pb2+). The various stretching and bending vibrational modes of borate and tellurite network have been identified through FTIR spectral measurements. The conversion of BO3 units into BO4 units increases NBOs in the glass network and the same is confirmed through FTIR spectra. The nephelauxetic ratio ([Formula: see text]) and bonding parameter (δ) value reveals that the Dy-O bond in prepared glasses possesses ionic nature. JO intensity parameters (Ω2, Ω4 and Ω6) of the present glasses follow the trend Ω2 > Ω4 > Ω6 uniformly in all the prepared glasses. Radiative parameters like transition probability (A), stimulated emission cross section[Formula: see text], branching ratio (ßR) values have been predicted from the absorption spectra of Dy3+ ions using JO theory. Among the prepared glasses TBZnD glass posses a better CIE 1931 colour chromaticity coordinates (0.33, 0.39) and CCT value (5019 K). Decay profile of 4F9/2 state of the Dy3+ ion exhibits non-exponential nature due to the interaction between Dy3+-Dy3+ ions. The nature of interaction between Dy3+-Dy3+ ions has been analyzed through Inokuti-Hirayama model and the best fit of S = 6 indicates that the dipole-dipole interaction is responsible for the energy transfer between Dy3+-Dy3+ ions. The glass containing Zn2+ ions posses encouraging results such as higher Y/B intensity ratio, stimulated emission cross section and higher branching ratio (4F9/2 â†’ 6H13/2). Thus the present study identified the Zn2+ ions as a better modifier ion to develop the Dy3+ doped glasses for various photonic applications.

14.
Eur Rev Med Pharmacol Sci ; 19(10): 1895-9, 2015 May.
Article in English | MEDLINE | ID: mdl-26044237

ABSTRACT

OBJECTIVE: Sea urchin gonad is considered as a highly prized delicacy in several countries. It is also rich in valuable bioactive compounds including polyunsaturated fatty acids (PUFAs) and ß-carotene. This study was undertaken to examine the antimicrobial properties of the ovary extract from sea urchin Diadema setosum against selected Gram-negative and Gram-positive bacteria. MATERIALS AND METHODS: The ovary extract was obtained using two different solvents such as methanol and chloroform. The obtained extract was used to examine its potential antimicrobial properties against the following 11 bacterial species using the disc diffusion method: Gram-negative bacteria (Salmonella typhi, Salmonella typhimurium, Shigella flexneri, Pseudomonas aeruginosa, Aeromonas hydrophila, Acinetobacter sp, Citrobacter freundii and Klebsiella pneumonia) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus epidermidis and Staphylococcus aureus). The activity was measured in terms of zone of inhibition (mm). RESULTS: The methanol extract exhibited a higher zone of inhibition against all the bacteria taken for examination. Whereas, the ovary extract obtained by chloroform did not show any antimicrobial activity against S. typhi, S. epidermidis, C. freundii and K. pneumonia. The results indicated that the ovary extract obtained by methanol extracts are capable of inhibiting the growth of pathogenic microbes taken for analysis. Moreover, the result indicates the presence of antimicrobial agents in sea urchin ovary. CONCLUSIONS: The study suggests that the ovary extract of D. setosum may be a potential source of antimicrobial agent for pathogenic microorganisms.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/isolation & purification , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Ovary , Tissue Extracts/administration & dosage , Animals , Female , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/growth & development , Humans , Sea Urchins
15.
Acta Chir Belg ; 115: 15-9, 2015.
Article in English | MEDLINE | ID: mdl-26021786

ABSTRACT

BACKGROUND: Parastomal hernia is a frequent complication after stoma formation. The objective of this prospective study was to find long-term outcome of prophylactic mesh placement in the pre-peritoneal space in order to prevent parastomal hernia. METHODS: Patients undergoing elective formation of permanent stoma were included in the study. A polypropylene mesh was placed in the pre-peritoneal space without any anchoring stitches and bowel was taken out through a central circular hole made in the mesh. These patients were followed up for 5 years-by clinical examination and CT scan when needed. RESULTS: A total of 42 patients were included in the study. These patients were followed up for a median period of 60 months (range 32-100 months). Twelve patients died before the 5-year follow up due to causes unrelated to stoma. As two patients were unable to be contacted, 28 patients remained in the long-term follow up. Three cases of parastomal hernia were detected after 5 years. None of these patients required repairing of the parastomal hernia. However, a previous study conducted 3 years ago found 4 cases of parastomal hernia that was treated by resiting the stomas. Therefore the total number of parastomal hernia detected in our series is 7 (incidence 25%). CONCLUSIONS: Putting a pre-peritoneal polypropylene mesh is an easy, quick and inexpensive method, and easy to learn. The outcome is better than creating stomas without mesh, but further studies are needed to explore potential benefits of different types of mesh and their methods of positioning and anchoring.


Subject(s)
Enterostomy/adverse effects , Hernia, Abdominal/prevention & control , Surgical Mesh , Surgical Stomas/adverse effects , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Hernia, Abdominal/diagnosis , Hernia, Abdominal/etiology , Humans , Male , Middle Aged , Peritoneum , Polypropylenes , Prospective Studies , Time Factors , Treatment Outcome
16.
Acta Chir Belg ; 115(1): 15-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-27384891

ABSTRACT

BACKGROUND: Parastomal hernia is a frequent complication after stoma formation. The objective of this prospective study was to find long-term outcome of prophylactic mesh placement in the pre-peritoneal space in order to prevent parastomal hernia. METHODS: Patients undergoing elective formation of permanent stoma were included in the study. A polypropylene mesh was placed in the pre-peritoneal space without any anchoring stitches and bowel was taken out through a central circular hole made in the mesh. These patients were followed up for 5 years-by clinical examination and CT scan when needed. RESULTS: A total of 42 patients were included in the study. These patients were followed up for a median period of 60 months (range 32-100 months). Twelve patients died before the 5-year follow up due to causes unrelated to stoma. As two patients were unable to be contacted, 28 patients remained in the long-term follow up. Three cases of parastomal hernia were detected after 5 years. None of these patients required repairing of the parastomal hernia. However, a previous study conducted 3 years ago found 4 cases of parastomal hernia that was treated by resiting the stomas. Therefore the total number of parastomal hernia detected in our series is 7 (incidence 25%). CONCLUSION: Putting a pre-peritoneal polypropylene mesh is an easy, quick and inexpensive method, and easy to learn. The outcome is better than creating stomas without mesh, but further studies are needed to explore potential benefits of different types of mesh and their methods of positioning and anchoring.


Subject(s)
Hernia, Abdominal/prevention & control , Surgical Mesh/statistics & numerical data , Surgical Stomas/adverse effects , Adult , Age Distribution , Aged , Aged, 80 and over , Cohort Studies , Female , Follow-Up Studies , Hernia, Abdominal/epidemiology , Hernia, Abdominal/etiology , Humans , Incidence , Kaplan-Meier Estimate , Male , Middle Aged , Peritoneal Cavity/surgery , Polypropylenes , Primary Prevention/methods , Prospective Studies , Reoperation , Risk Assessment , Sex Distribution , Time Factors , Treatment Outcome
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt C: 1684-97, 2015 Feb 05.
Article in English | MEDLINE | ID: mdl-25459733

ABSTRACT

A new series of white light emitting Dy(3+) doped Lead tellurofluoroborate glasses have been prepared and their spectroscopic and energy transfer behavior were explored through analyzing XRD, FTIR, Raman, SEM, EDAX, optical absorption, photoluminescence and lifetime measurements. The fundamental stretching of the various borate and tellurite networks were identified using FTIR and Raman spectral analysis. The bonding parameter studies reveal the ionic nature of the DyO bond in the present glasses. The Judd-Ofelt (JO) intensity parameters determined from the absorption spectra have been used to investigate the nature of bonding and symmetry orientation of the Dy-ligand field environment. The luminescence intensity increases with increasing Dy(3+) ion concentration up to 0.5wt%, beyond that luminescence quenching is observed. The JO parameters have been used to determine the transition probability (A), stimulated emission cross-section (σP(E)), radiative lifetime (τR) and branching ratios (ßR) for the different emission transitions from the (4)F9/2 excited level. The higher σP(E) and ßR values of the (4)F9/2→(6)H15/2 and (4)F9/2→(6)H13/2 transitions suggest the possible laser action in the visible region. The Y/B ratio, CIE chromaticity color coordinates (x, y) and Color correlated temperature (CCT) were also estimated from the luminescence spectra for different concentration as well as pumping wavelengths. The x, y chromaticity color coordinates fall within the white light region and the white light can be tuned by varying the excitation wavelengths. The lifetime of the (4)F9/2 excited state were measured and is found to decrease with increasing Dy(3+) ion content. The non-exponential behavior is predominant in higher Dy(3+) ion content glasses and is due to the efficient energy transfer between Dy(3+)Dy(3+) ions. The decay curves were fitted to the Inokuti-Hirayama (IH) model to understand the nature of energy transfer. Among the prepared glasses, 0.5DPTFB glass possesses higher A,ßR,σP(E),η values and is suggested for lasers and WLED applications.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 135: 1090-8, 2015 Jan 25.
Article in English | MEDLINE | ID: mdl-25173526

ABSTRACT

Er(3+) doped Barium tellurofluoroborate glasses (BTFBxE) with the chemical composition (30-x)TeO2+30B2O3+20BaO+20BaF+xEr2O3 (where x=0.01, 0.05, 0.1, 0.5, 1.0 and 2.0 in wt%) were prepared following the melt quenching technique. The different vibrational modes of borates and tellurites in the prepared glasses were explored through FTIR and Raman spectra. The optical absorption spectra have been used to determine the ionic/covalent nature of the metal-ligand bond in the prepared glasses with the help of Nephelauxetic ratio (ß) and bonding parameter (δ) studies. The optical band gap of direct and indirect allowed transitions were determined from Tauc's plot and the variations of band gap energy with structural arrangements were discussed. The Urbach energy values were determined and the relatively lower values of the Urbach's energy reveal the minimal degree of disorderness in the prepared glasses. The oscillator strengths (fexp and fcal) and Judd-Ofelt (JO) intensity parameters (Ω2, Ω4 and Ω6) were calculated with the application of JO theory and the trends of the JO intensity parameters are found to be Ω2>Ω6>Ω4 for all the prepared glasses with a minimum variation in Ω2 intensity parameter values. A bright green emission was observed from the (2)H11/2+(4)S3/2→ (4)I15/2 transition and the radiative properties such as transition probability (A), stimulated emission cross-section (σP(E)), branching ratio (ßr) and radiative lifetime (τ) were calculated using the JO parameters. The suitability of the prepared glasses for the fabrication of photonic devices were also discussed and reported in the present work.


Subject(s)
Barium/chemistry , Borates/chemistry , Erbium/chemistry , Luminescence , Glass , Optical Phenomena , Spectroscopy, Fourier Transform Infrared , Spectroscopy, Near-Infrared , Spectrum Analysis, Raman , Thermodynamics , X-Ray Diffraction
19.
Article in English | MEDLINE | ID: mdl-25004904

ABSTRACT

Phytohaemagglutinin (PHA) is a lectin obtained from Phaseolus vulgaris (red kidney beans), that acts as a mitogen in human leucocyte culture and is commercially available from Gibco. This PHA (Gibco) was found to be very expensive, hence other inexpensive sources that can be used in all kinds of cytogenetics labs (rich and poor), were attempted. One such successful attempt was PHA extract from seeds of P.vulgaris. This paper details the methodology of extraction and application of PHA from seeds of P.vulgaris. Attempts has been made to identify the chemical and physical properties of the products in the extract, analyzed by various spectroscopic and analytical techniques. The analysis clearly indicates that the product from Phaseolus seeds extract was found to be similar to the commercially available PHA (Gibco) in the cytogenetic study of human leucocyte cultures. The present study enforces the possible utility of the plant extract directly for human leucocyte cultures.


Subject(s)
Cytogenetic Analysis/methods , Phaseolus/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Seeds/chemistry , Cataract/genetics , Cells, Cultured , Chromatography, Thin Layer , Chromosome Aberrations , Diabetes Mellitus, Type 2/genetics , Humans , Leukocytes/drug effects , Magnetic Resonance Spectroscopy , Phytohemagglutinins , Plant Extracts/analysis , Spectrophotometry, Ultraviolet
20.
Eur Rev Med Pharmacol Sci ; 18(12): 1694-7, 2014.
Article in English | MEDLINE | ID: mdl-24992608

ABSTRACT

BACKGROUND: Although the Chilaiditi sign correctly underestimates the radiological presence of air-under-the-diaphragm, in few cases it has lead to delays in the diagnosis of underlying pneumoperitoneum. In this article we report the case of a young lady presenting with acute pancreatitis and radiographic findings of "left-sided" Chilaiditi sign with underlying a large gastric perforation. CASE REPORT: A 35 year old Caucasian female presented to the Emergency Department with a twenty-four hour history of severe epigastric pain radiating into her back. Stable observations, mildly raised white cell count, increased amylase and subdiaphragmatic radiolucency were interpreted as acute pancreatitis with Chilaiditi sign and treated accordingly. Twenty-four hours later the deterioration of the clinical conditions required a CT scan and an emergency laparotomy that lead to the diagnosis of a large gastric perforation. However, after several days she died of a disseminated intravascular coagulation in the Intensive Care Unit. CONCLUSIONS: In our case the young age of the patient and lack of underlying comorbidities initially compensated the severity of the perforation until it became evident from the absent resolution of the pancreatitis. Bearing this in mind, radiological appearances similar to Chilaiditi sign with significant symptoms or signs should be investigated with a CT scan in order to reach promptly a correct diagnosis.


Subject(s)
Pancreatitis/diagnostic imaging , Stomach Rupture/diagnostic imaging , Abdominal Pain/diagnostic imaging , Adult , Female , Humans , Radiography
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