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1.
Heliyon ; 9(4): e14637, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37025788

ABSTRACT

Despite possessing attractive features such as autotrophic growth on minimal media, industrial applications of cyanobacteria are hindered by a lack of genetic manipulative tools. There are two important features that are important for an effective manipulation: a vector which can carry the gene, and an induction system activated through external stimuli, giving us control over the expression. In this study, we describe the construction of an improved RSF1010-based vector as well as a temperature-inducible RNA thermometer. RSF1010 is a well-studied incompatibility group Q (IncQ) vector, capable of replication in most Gram negative, and some Gram positive bacteria. Our designed vector, named pSM201v, can be used as an expression vector in some Gram positive and a wide range of Gram negative bacteria including cyanobacteria. An induction system activated via physical external stimuli such as temperature, allows precise control of overexpression. pSM201v addresses several drawbacks of the RSF1010 plasmid; it has a reduced backbone size of 5189 bp compared to 8684 bp of the original plasmid, which provides more space for cloning and transfer of cargo DNA into the host organism. The mobilization function, required for plasmid transfer into several cyanobacterial strains, is reduced to a 99 bp region, as a result that mobilization of this plasmid is no longer linked to the plasmid replication. The RNA thermometer, named DTT1, is based on a RNA hairpin strategy that prevents expression of downstream genes at temperatures below 30 °C. Such RNA elements are expected to find applications in biotechnology to economically control gene expression in a scalable manner.

2.
Int J Obstet Anesth ; 49: 103236, 2022 02.
Article in English | MEDLINE | ID: mdl-34840019

ABSTRACT

BACKGROUND: We present the care of 17 consecutive pregnant patients who required mechanical ventilation for Coronavirus Disease 2019 (COVID-19) pneumonia at a quaternary referral center in the United States. We retrospectively describe the management of these patients, maternal and fetal outcomes, as well as the feasibility of prone positioning and delivery. METHODS: Between March 2020 and June 2021, all pregnant and postpartum patients who were mechanically ventilated for COVID-19 pneumonia were identified. Details of their management including prone positioning, maternal and neonatal outcomes, and complications were noted. RESULTS: Seventeen pregnant patients required mechanical ventilation for COVID-19. Thirteen patients received prone positioning, with a total of 49 prone sessions. One patient required extracorporeal membrane oxygenation. All patients in this series survived until at least discharge. Nine patients delivered while mechanically ventilated, and all neonates survived, subsequently testing negative for SARS-CoV-2. There was one spontaneous abortion. Four emergent cesarean deliveries were prompted by refractory maternal hypoxemia or non-reassuring fetal heart rate after maternal intubation. CONCLUSIONS: Overall, maternal and neonatal survival were favorable even in the setting of severe COVID-19 pneumonia requiring mechanical ventilation. Prone positioning was well tolerated although the impact of prone positioning or fetal delivery on maternal oxygenation and ventilation are unclear.


Subject(s)
COVID-19 , Female , Humans , Infant, Newborn , Pregnancy , Prone Position , Referral and Consultation , Respiration, Artificial , Retrospective Studies , SARS-CoV-2 , United States
3.
Biometals ; 34(6): 1217-1235, 2021 12.
Article in English | MEDLINE | ID: mdl-34398357

ABSTRACT

Copper (Cu) and its alloys are prospective materials in fighting covid-19 virus and several microbial pandemics, due to its excellent antiviral as well as antimicrobial properties. Even though many studies have proved that copper and its alloys exhibit antiviral properties, this research arena requires further research attention. Several studies conducted on copper and its alloys have proven that copper-based alloys possess excellent potential in controlling the spread of infectious diseases. Moreover, recent studies indicate that these alloys can effectively inactivate the covid-19 virus. In view of this, the present article reviews the importance of copper and its alloys in reducing the spread and infection of covid-19, which is a global pandemic. The electronic databases such as ScienceDirect, Web of Science and PubMed were searched for identifying relevant studies in the present review article. The review starts with a brief description on the history of copper usage in medicine followed by the effect of copper content in human body and antiviral mechanisms of copper against covid-19. The subsequent sections describe the distinctive copper based material systems such as alloys, nanomaterials and coating technologies in combating the spread of covid-19. Overall, copper based materials can be propitiously used as part of preventive and therapeutic strategies in the fight against covid-19 virus.


Subject(s)
Alloys/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19 Drug Treatment , Copper/chemistry , Animals , Anti-Infective Agents, Local , Disinfection , Humans , Metal Nanoparticles/chemistry , Nanostructures/chemistry , Pandemics , SARS-CoV-2
4.
Int J Biol Macromol ; 185: 644-653, 2021 Aug 31.
Article in English | MEDLINE | ID: mdl-34217741

ABSTRACT

Highly specific graphene-DNA interactions have been at the forefront of graphene-based sensor design for various analytes, including DNA itself. However, in addition to its detection, DNA also needs to be characterized according to its size and concentration in a sample, which is an additional analytical step. Designing a highly sensitive and selective DNA sensing and characterization platform is, thus, of great interest. The present study demonstrates that a bio-derived, naturally fluorescent protein C-phycoerythrin (CPE) - graphene oxide (GO) bio-composite can be used to detect dsDNA in nanomolar quantities efficiently via fluorescent "turn off/on" mechanism. Interaction with GO temporarily quenches CPE fluorescence in a dose-dependent manner. Analytical characterization indicates an indirect charge transfer with a corresponding loss of crystalline GO structure. The fluorescence is regained with the addition of DNA, while other biomolecules do not pose any hinderance in the detection process. The extent of regain is DNA length dependent, and the corresponding calibration curve successfully quantifies the size of an unknown DNA. The incubation time for detection is ~3-5 min. The bio-composite platform also works successfully in a complex biomolecule matrix and cell lysate. However, the presence of serum albumin poses a hinderance in the serum sample. Particle size analysis proves that CPE displacement from GO surface by the incoming DNA is the reason for the 'turn on' response, and that the sensing process is exclusive to dsDNA. This new platform could be an exciting and rapid DNA sensing and characterization tool.


Subject(s)
DNA/analysis , Graphite/chemistry , Phycoerythrin/chemistry , Protein C/chemistry , Biosensing Techniques , Dynamic Light Scattering , Fluorescence , Particle Size , X-Ray Diffraction
7.
Br J Anaesth ; 122(6): 751-759, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30916034

ABSTRACT

BACKGROUND: Gestational changes in coagulation factor concentrations include elevations in fibrinogen, Factor VIII, and von Willebrand factor (vWF). We hypothesised that blood samples from term pregnant (TP) subjects are less prone to coagulation disturbances from haemodilution compared with those from non-pregnant (NP) females. METHODS: Blood samples were collected from 15 NP and 15 TP subjects. In vitro haemodilution with normal saline was assessed by modified Clauss fibrinogen assay, factor activity, flow-chamber assay, and thromboelastometry. The impact of human fibrinogen concentrate (hFC), cryoprecipitate, and vWF/Factor VIII (FVIII) concentrate replacement in diluted TP and NP blood was compared. Thrombin generation and activated protein C sensitivity were assessed. RESULTS: TP blood contained twice the concentrations of fibrinogen, FVIII, and vWF relative to NP blood (P<0.0001). Platelet thrombus formation (PTF) under flow was reduced by 99.2% and 69.2% in diluted NP and TP blood, respectively. Platelet thrombus formation was partially restored by adding vWF/FVIII, but not hFC or cryoprecipitate. Fibrin clot firmness approached the threshold of 10 mm in diluted NP blood, and clot firmness was effectively restored by hFC, but not by vWF/FVIII. In the presence of thrombomodulin, peak thrombin generation was decreased by 86.7% in NP plasma, but by 31.8% in TP plasma (P<0.0001 vs NP plasma), indicating reduced activated protein C sensitivity in TP plasma. Both elevated FVIII and haemodilution contributed to activated protein C insensitivity. CONCLUSIONS: Our in vitro model showed relative resistance of TP blood to dilutional coagulation changes with respect to platelet adhesion, fibrin polymerisation, and thrombin generation. Careful therapeutic monitoring for different pro-haemostatic agents in pregnant women is warranted.


Subject(s)
Blood Coagulation Disorders/blood , Blood Coagulation Factors/analysis , Hemodilution/adverse effects , Pregnancy Complications, Hematologic/blood , Adult , Blood Coagulation Disorders/etiology , Blood Specimen Collection/methods , Drug Monitoring/methods , Factor VIII/analysis , Female , Fibrinogen/analysis , Humans , Pregnancy , Pregnancy Complications, Hematologic/etiology , Protein C/analysis , Thrombelastography/methods , Thrombin/biosynthesis , Young Adult , von Willebrand Factor/analysis
8.
ACS Omega ; 3(10): 12562-12574, 2018 Oct 31.
Article in English | MEDLINE | ID: mdl-30411010

ABSTRACT

The current study evaluates antidiabetic, anticoagulant, and antiplatelet activity of novel benzimidazole-containing quinolinyl oxadiazoles. These derivatives are synthesized and characterized using spectroscopy (FT-IR, 1H NMR, and mass spectroscopy) and single-crystal X-ray diffraction methods. The inhibitory effects of these compounds were evaluated by the α-glucosidase inhibitory assay and shows the activity in the range of IC50 = 0.66 ± 0.05 to 3.79 ± 0.46 µg/mL. In addition, molecular docking studies revealed that benzimidazole-containing quinolinyl oxadiazoles can correctly dock into the target receptor protein of the human intestinal α-glucosidase, while their bioavailability/drug-likeness was predicted to be acceptable but requires further optimization. On the other hand, compound 8a and 8d showed anticoagulant activity as they enhanced the clotting time from control 180-410 and 180-390 s, respectively, in platelet rich plasma and 230-460 and 230-545 s in platelet poor plasma. Furthermore, only 8a showed antiplatelet activity by inhibiting epinephrine-induced platelet aggregation, and the observed aggregation inhibition was found to be 93.4%. Compounds 8a-f show nontoxic properties because of the non-hydrolyzing properties in the RBC cells. In addition, 8a and 8d show anti-edema and anti-hemorrhagic properties in the experimental mice. These findings reveal that benzimidazole-containing quinolinyl oxadiazoles act as α-glucosidase inhibitors to develop novel therapeutics for treating type-II diabetes mellitus and can act as lead molecules in drug discovery as potential antidiabetic and antithrombotic agents.

9.
Bioresour Technol ; 244(Pt 2): 1216-1226, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28552566

ABSTRACT

Microalgae, due to various environmental stresses, constantly tune their cellular mechanisms to cope with them. The accumulation of the stress metabolites is closely related to the changes occurring in their metabolic pathways. The biosynthesis of metabolites can be triggered by a number of abiotic stresses like temperature, salinity, UV- radiation and nutrient deprivation. Although, microalgae have been considered as an alternative sustainable source for nutraceutical products like pigments and omega-3 polyunsaturated fatty acids (PUFAs) to cater the requirement of emerging human population but inadequate biomass generation makes the process economically impractical. The stress metabolism for carotenoid regulation in green algae is a 2-step metabolism. There are a few major stresses which can influence the formation of phycobiliprotein in cyanobacteria. This review would primarily focus on the cellular level changes under stress conditions and their corresponding effects on lipids (including omega-3 PUFAs), pigments and polymers.


Subject(s)
Metabolic Networks and Pathways , Microalgae , Biomass , Chlorophyta , Lipids
11.
PLoS One ; 11(12): e0167702, 2016.
Article in English | MEDLINE | ID: mdl-27942031

ABSTRACT

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat-Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011-14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.


Subject(s)
Databases, Genetic , Disease Resistance , Triticum/genetics , Ascomycota/pathogenicity , India , Quantitative Trait Loci , Triticum/classification , Triticum/immunology , Triticum/microbiology
12.
Bioresour Technol ; 218: 1178-86, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27472494

ABSTRACT

The eicosapentaenoic acid rich marine eustigmatophyte Nannochloropsis oceanica was grown in wastewaters sampled from four different industries (i.e. pesticides industry, pharmaceutical industry, activated sludge treatment plant of municipality sewage and petroleum (oil) industry). Under the wastewater based growth conditions used in this study, the biomass productivity ranged from 21.78±0.87 to 27.78±0.22mgL(-1)d(-1) in relation to freeze dried biomass, while the lipid productivity varied between 5.59±0.02 and 6.81±0.04mgL(-1)d(-1). Although comparatively higher biomass, lipid and EPA productivity was observed in Conway medium, the %EPA content was similarly observed in pesticides industry and municipal effluents. The results highlight the possibility of selectively using wastewater as a growth medium, demonstrating the elevated eicosapentaenoic acid content and biodiesel properties, that complies with the European standards for biodiesel.


Subject(s)
Biofuels/microbiology , Biomass , Eicosapentaenoic Acid/chemistry , Microalgae/chemistry , Wastewater/microbiology , Microalgae/growth & development , Sewage/chemistry , Stramenopiles/chemistry , Stramenopiles/growth & development
13.
Br J Anaesth ; 116(6): 811-21, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27099154

ABSTRACT

BACKGROUND: Awake craniotomy (AC) is performed for the resection of brain tumours in close proximity to areas of eloquent brain function to maximize reduction of tumour mass and minimize neurological injury. This study compares the efficacy and safety of dexmedetomidine vs propofol-remifentanil-based conscious sedation, during AC for supratentorial tumour resection. METHODS: Prospective, randomized, controlled trial including 50 adult patients undergoing AC who were randomly assigned to a dexmedetomidine (DEX group, n=25) or propofol-remifentanil group (P-R group, n=25). The primary outcome was the ability to perform intraoperative brain mapping assessed on a numeric rating scale (NRS). Secondary outcome was the efficacy of sedation measured by the modified Observer's Assessment of Alertness/Sedation (OAA/S) scale. Other outcome measures including haemodynamic and respiratory variables, pain, sedation and anxiety scores, adverse events, and patient satisfaction were also compared. RESULTS: There were no differences between DEX and P-R groups regarding the ability to perform intraoperative brain mapping [mean NRS score (95% CI): 10.0 (9.9-10.0) vs 9.7 (9.5-10.0), P=0.13] and level of sedation during mapping [mean OAA/S score (95% CI): 4.1 (3.5-4.7) vs 4.3 (3.9-4.7), P=0.51], respectively. Respiratory adverse events were more frequent in the P-R group (20 vs 0%, P=0.021). Heart rate was significantly lower in the DEX group across time (P<0.001); however, the need for treatment of bradycardia was not different between groups. CONCLUSIONS: Quality of intraoperative brain mapping and efficacy of sedation with dexmedetomidine were similar to propofol-remifentanil during AC for supratentorial tumour resection. Dexmedetomidine was associated with fewer respiratory adverse events. CLINICAL TRIAL REGISTRATION: NCT01545297.


Subject(s)
Conscious Sedation/methods , Craniotomy/methods , Dexmedetomidine , Hypnotics and Sedatives , Piperidines , Propofol , Adult , Aged , Aged, 80 and over , Brain Mapping , Conscious Sedation/adverse effects , Dexmedetomidine/adverse effects , Double-Blind Method , Female , Hemodynamics/drug effects , Humans , Hypnotics and Sedatives/adverse effects , Male , Middle Aged , Patient Satisfaction , Piperidines/adverse effects , Propofol/adverse effects , Prospective Studies , Remifentanil , Respiratory Mechanics/drug effects , Supratentorial Neoplasms/surgery , Wakefulness
14.
Environ Health Prev Med ; 21(4): 248-57, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26943650

ABSTRACT

OBJECTIVES: This study was done to determine the risk factors, management practices and awareness about diarrhoea. METHODS: It was a cross sectional study done in a semi urban and rural areas of South Canara district of India in February 2013. A total of 167 households (575 study population) chosen systematic randomly were visited and one adult member in each house was interviewed. The houses were also inspected to assess the living conditions. RESULTS: Mean age of study population was 31.1 ± 20.2 years. The period prevalence of diarrhoea was 69 (12 %). Commonest associated symptoms in cases of diarrhoea were fever 30 (43.4 %) followed by abdominal cramps 29 (42 %). Nearly half of the cases with diarrhoea 34 (49.3 %) did not take any medications. Commonest treatment taken was allopathic medicines 26 (37.8 %) followed by home remedies 8 (22.9 %). Age ≤10 years (p < 0.001) was associated with risk of developing diarrhoea using binary logistic regression analysis. Among the 167 participants, awareness level about the disease was poor among 16 (9.6 %) and moderate among 149 (89.2 % participants). Awareness level was more among females (p = 0.001) and literate participants (p = 0.013). One hundred and sixteen (69.5 %) participants were not aware of any sign or symptom of dehydration other than loose stools. Majority of the participants 138 (82.6 %) preferred home remedies as the initial management of diarrhoea. Misconception about fluid restriction in diarrhoea was stated by 12(7.2 %) participants. CONCLUSION: Public education program on proper feeding and management practices is required to address the various issues identified and for containment of diarrhoea cases in future.


Subject(s)
Diarrhea/epidemiology , Diarrhea/therapy , Health Knowledge, Attitudes, Practice , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Cross-Sectional Studies , Diarrhea/etiology , Diarrhea/psychology , Female , Fluid Therapy/psychology , Fluid Therapy/statistics & numerical data , Humans , India/epidemiology , Infant , Infant, Newborn , Male , Middle Aged , Prevalence , Risk Factors , Young Adult
15.
J Matern Fetal Neonatal Med ; 29(13): 2077-82, 2016.
Article in English | MEDLINE | ID: mdl-26333286

ABSTRACT

OBJECTIVES: To assess the plasma markers of endothelial dysfunction: VonWillebrand factor (vWF), Platelet derived microparticles (PMPs), and Endothelin-1 (ET-1) in various types of hypertensive disorders of pregnancy and correlate with the pregnancy outcome. METHODS: Plasma levels of vWF, PMPs and ET-1 were analyzed by ELISA kits in gestational hypertension (GH), late onset preeclampsia (LOPE), early onset preeclampsia (EOPE), eclampsia (E) and control pregnant women (CPW) during third trimester. The gestational age at the time of delivery (GA) and birthweight (BW) of the baby also were measured. RESULTS: The GA and the BW of the baby were found to be significantly lower in EOPE and eclampsia compared to CPW, GH and LOPE. The circulating levels of markers of endothelial dysfunction: vWF, PMPs and ET-1 were significantly higher in EOPE and Eclampsia compared to CPW, GH. Also a negative correlation was observed between vWF levels with pregnancy outcome; GA and BW. CONCLUSIONS: A generalized endothelial dysfunction and poor birth outcomes were observed in hypertensive disorders of pregnancy. There is a spectrum of biochemical derangements related to endothelial dysfunction in GH, EOPE, LOPE and E in that order.


Subject(s)
Biomarkers/blood , Endothelium, Vascular/physiopathology , Hypertension, Pregnancy-Induced/blood , Vascular Diseases/blood , Adult , Birth Weight , Case-Control Studies , Female , Gestational Age , Humans , Hypertension, Pregnancy-Induced/physiopathology , India , Infant, Newborn , Pilot Projects , Pregnancy , Pregnancy Outcome , Vascular Diseases/physiopathology , Young Adult
16.
Mater Sci Eng C Mater Biol Appl ; 58: 36-43, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26478284

ABSTRACT

A novel green source was opted to synthesize silver nanoparticles using dried roasted Coffea arabica seed extract. Bio-reduction of silver was complete when the mixture (AgNO3+extract) changed its color from light to dark brown. UV-vis spectroscopy result showed maximum adsorption at 459 nm, which represents the characteristic surface plasmon resonance of nanosilver. X-ray crystal analysis showed that the silver nanoparticles are highly crystalline and exhibit a cubic, face centered lattice with characteristic (111), (200), (220) and (311) orientations. Particles exhibit spherical and ellipsoidal shaped structures as observed from TEM. Composition analysis obtained from SEM-EDXA confirmed the presence of elemental signature of silver. FTIR results recorded a downward shift of absorption bands between 800-1500 cm(-1) indicting the formation of silver nanoparticles. The mean particle size investigated using DLS was found to be in between 20-30 nm respectively. Anti-bacterial activity of silver nanoparticles on E. coli and S. aureus demonstrated diminished bacterial growth with the development of well-defined inhibition zones.


Subject(s)
Anti-Bacterial Agents/chemistry , Coffea/chemistry , Green Chemistry Technology/methods , Metal Nanoparticles/chemistry , Plant Extracts/chemistry , Seeds/chemistry , Silver/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Plant Extracts/pharmacology , Silver/pharmacology , Spectrophotometry, Ultraviolet
17.
J Nanosci Nanotechnol ; 15(5): 3522-9, 2015 May.
Article in English | MEDLINE | ID: mdl-26504972

ABSTRACT

Passive autocatalytic recombiner (PAR) is one of the most suitable devices for mitigation of hydrogen, generated in nuclear power plant under accidental conditions. For this purpose we report development of stainless steel wire gauze supported Pt-Ru nanoparticles as catalysts. Simultaneous electroless deposition has been employed for the synthesis of the catalysts. Pt-Ru based bimetallic catalysts were characterized for their rate of coating kinetics, noble metal loading, phase purity by XRD and surface morphology by SEM, TEM and elemental analysis by SIMS. Developed catalysts were found to be active for efficient recombination of hydrogen and oxygen in air as well as in presence of various prospective poisons like CO2, CH4, CO and relative humidity. Pt-Ru based bimetallic catalyst with 0.9% loading was found to be active for CO poisoning up to 400 ppm of CO.

18.
Bioresour Technol ; 197: 363-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26344244

ABSTRACT

Nutrients are the deciding factors in the biological production of bioactive compounds. Various growth media like BG11, Zarrouk's and Chu's 10 were studied for carotenoid production in Synechocystis sp. CCNM 2501. Maximum carotenoid content (dry weight basis) was found in Zarrouk's medium (ZM, 7.99mgg(-1)) followed by BG11 (5.13mgg(-1)). Echinenone content was 4 times higher in ZM (3.81mgg(-1)) as compared to BG11 (0.95mgg(-1)) and Chu's 10 (0.77mgg(-1)). Being an economical medium, BG11 was selected for carotenoid production. Further, increase in salinity from 0 to 0.2M in BG11 medium increases total carotenoid content from 5.82 to 7.05mgg(-1) and later it declines to 6.23mgg(-1) (1M). 3 times more ß-carotene is produced at 1M salinity as compared to control BG11. The variation in carotenoid composition with change in nutrients/salinity can be a good strategy to enhance certain targeted carotenoids.


Subject(s)
Carotenoids/biosynthesis , Culture Media , Salinity , Synechocystis/metabolism , beta Carotene/biosynthesis , Carotenoids/analysis , Synechocystis/chemistry , beta Carotene/analysis
19.
Phys Chem Chem Phys ; 17(10): 6896-904, 2015 Mar 14.
Article in English | MEDLINE | ID: mdl-25673368

ABSTRACT

A stable photocatalyst, CdS dispersed on zeolite with Pd as both the dopant and the co-catalyst, has been developed. Enhancement of photocatalytic activity for hydrogen generation is observed for CdS when doped with palladium and dispersed on NaY-zeolite (CdPdS-Z). A further increase in the photocatalytic activity of CdPdS-Z is observed when palladium is added as a co-catalyst (Pd-CdPdS-Z). Cd0.95Pd0.05S-Z is synthesized via a facile soft chemical route and the Pd co-catalyst is loaded onto the composite using a wet impregnation method. This composite catalyst exists as two phases consisting of CdPdS and zeolite and CdPdS exists as a highly dispersed phase on zeolite as revealed by TEM studies. The Pd doped CdS-zeolite composite exhibits increased visible light absorption indicating the alteration of the band structure of CdS as a result of doping. Time resolved fluorescence studies reveal that the lifetime of the charge carriers is higher in the composites than in pure CdS. A detailed characterization using XRD, Raman and X-ray photoelectron spectroscopy indicates that Pd has substituted for Cd in the CdS lattice and Pd exists in the Pd(2+) oxidation state. Solid state MAS NMR studies indicate that an interaction exists between CdS (or CdPdS) and zeolite at the interface and Cd selectively interacts with Al of the zeolite framework. The photocatalytic activity of the Pd-CdPdS-Z catalyst remains unchanged with repeated cycles. Characterization of the used catalyst indicates that it is stable under the present experimental conditions. The enhanced photocatalytic activity of Pd-CdPdS-Z is attributed to the enhanced visible light absorption arising due to Pd doping and increased lifetime of the photogenerated charge carriers assisted by zeolite and the Pd co-catalyst. This study highlights the multiple roles played by palladium in enhancing the photocatalytic activity of the CdS-zeolite composite.

20.
Prev Vet Med ; 116(1-2): 203-8, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-24910425

ABSTRACT

The existence of unowned, free-roaming dogs capable of maintaining adequate body condition without direct human oversight has serious implications for disease control and animal welfare, including reducing effective vaccination coverage against rabies through limiting access for vaccination, and absolving humans from the responsibility of providing adequate care for a domesticated species. Mark-recapture methods previously used to estimate the fraction of unowned dogs in free-roaming populations have limitations, particularly when most of the dogs are owned. We used participatory methods, described as Participatory Rural Appraisal (PRA), as a novel alternative to mark-recapture methods in two villages in Bali, Indonesia. PRA was implemented at the banjar (or sub-village)-level to obtain consensus on the food sources of the free-roaming dogs. Specific methods included semi-structured discussion, visualisation tools and ranking. The PRA results agreed with the preceding household surveys and direct observations, designed to evaluate the same variables, and confirmed that a population of unowned, free-roaming dogs in sufficiently good condition to be sustained independently of direct human support was unlikely to exist.


Subject(s)
Animal Welfare , Community-Based Participatory Research/methods , Dog Diseases/prevention & control , Health Status , Ownership , Animals , Dogs , Humans , Indonesia
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