897 research outputs found
Increased expression of NADP malic enzyme in the guard cells of \u3ci\u3eArabidopsis\u3c/i\u3e plants
Plants lose their water as transpiration by stomatal opening, which is governed by guard cells surrounding the stomata. Influx of ions such as K+, Cl-, from neighboring cells into guard cells, and malate synthesis within guard cells increases turgor pressure opening the stomata. Stomata close when K+ and Cl- efflux out, and the cytosolic isoform of NADP ME convert malate to pyruvate. We hypothesize that stomatal closure can be controlled by increased NADP ME activity in guard cells. More than one of the homozygous transgenic Arabidopsis plants that are transformed with a guard cell promoter driving expression of maize NADP ME have been obtained by herbicide screening. Molecular studies have confirmed presence of the transgene in these transformants. Enzyme assays shows higher ME activity in these transformants, indicating an active form of maize ME. Such transgenic plants would help to determine effects of increased ME activity on plant water loss
Tunnelling Characteristics of Stone-Wales Defects in Monolayers of Sn and Group-V Elements
Topological defects in ultrathin layers are often formed during synthesis and
processing, thereby, strongly influencing their electronic properties . In this
paper, we investigate the role of Stone-Wales (SW) defects in modifying the
electronic properties of the monolayers of Sn and group-V elements. The
calculated results find the electronic properties of stanene (monolayer of Sn
atoms) to be strongly dependent on the concentration of SW-defects e.g.,
defective stanene has nearly zero band gap (~ 0.03 eV) for the defect
concentration of 2.2 x 10^13 cm^-2 which opens up to 0.2 eV for the defect
concentration of 3.7 x 10^13 cm^-2. In contrast, SW-defects appear to induce
conduction states in the semiconducting monolayers of group-V elements. These
conduction states act as channels for electron tunnelling, and the calculated
tunnelling characteristics show the highest differential conductance for the
negative bias with the asymmetric current-voltage characteristics. On the other
hand, the highest differential conductance was found for the positive bias in
stanene. Simulated STM topographical images of stanene and group-V monolayers
show distinctly different features in terms of their cross-sectional views and
distance-height profiles which can serve as fingerprints to identify the
topological defects in the monolayers of group-IV and group-V elements in
experiments.Comment: 18 pages, 5 figures, 1 tabl
Screening of plastic degrading bacteria from dumped soil area
Plastic wastes accumulating in the environment are posing an ever increasing ecological threat. Plastics that are biodegradable can be considered environment friendly, they have an increasing range of potential application and are driven by the growing use of plastics in packaging. In this study, the biodegradation of polythene bag was analyzed 1 month of incubation in liquid culture method. Microbial counts in the degrading materials were recorded up to 0.0278×109 per gram for total heterotrophic bacteria. The microbial species found associated with the degrading materials were identified as two Gram positive and five Gram negative bacteria. The microbial species associated with the polythene materials were identified as Bacillus subtilis, Bacillus amylolyticus, Arthobacter defluvii. The efficacy of microbes in the degradation of plastics were analyzed in liquid (shaker) culture method, among the bacteria Bacillus amylolyticus degrades plastic more in 1 month (30% weight loss/month) period compared to others and lowest degradation rate was observed in case of Bacillus subtilis (20% weight loss/month). This work reveals that Bacillus amylolyticus posses greater potential to degrade plastics when compared with other bacteria
Comparison of three clinical and three ultrasonic equations in predicting fetal birth weight
Background: Antenatal assessment of fetal weight is important part in the management decisions during labour, thereby improving perinatal outcome. There are a large number of clinical methods and ultrasonic formulae for predicting fetal birth weight (EBW) with varying degrees of accuracy. This study was an attempt to compare the accuracy of three clinical and three ultrasonic methods in Indian population. The method with highest accuracy can be used in high and low resource setting in a country like ours with diverse resource settings.Methods: This was a prospective non randomized cohort study done on 100 antenatal patients in PGIMER, Dr. RML Hospital; New Delhi from Nov 2011 to Jan 2013 EBW (Expected Birth Weight) was calculated applying the 6 formulae three clinical and three ultrasonic and statistical analysis done after delivery comparing with ABW (Actual Birth Weight).Results: Accuracy in all ABW within 10% of ABW was 94 % with Johnson's method, 92 %with Dares method and 62 % with obstetrical equation. It was 100% with Hadlock 2 equation, 96% with Shepherd's and 86% with Warsoff equation Sensitivity for IUGR i.e. wt <2.5 kg was low in clinical methods, highest was only 46.2% with Johnsons. In ultrasonic methods all the three equations had 100% sensitivity making ultrasound the preferred modality in diagnosing macrosomia.Conclusions: The major finding of this study is that clinical estimation of fetal weight is as accurate as ultrasonographic method of estimation within normal range of birth weight Ultrasonographic methods was statistically more accurate with smaller mean errors and more within 10% of actual birth weight. Johnson formula gave most accuracy in clinical methods Ultrasound should be used to confirm clinical methods if IUGR or Macrosomia is suspected. No single method should be used if EBW is a part of decision but two or more methods should be combined
Knowledge and attitude regarding epidural analgesia among expectant mothers
Background: Pain relief is an important issue for women in labour. Epidural analgesia provides safe and effective pain relief. But It has not been fully accepted and is not routinely practiced in most of the centres in developing countries despite of many advantages of this technique. Therefore, this study has been conducted with an objective to assess the knowledge and attitude regarding epidural analgesia among expectant mothers.Methods: A descriptive study was conducted on 60 expectant mothers visiting antenatal OPD at DMC & Hospital, Ludhiana selected by convenience sampling technique. Knowledge assessed by using a structured questionnaire and attitude assessed by 3 point likert scale regarding epidural analgesia. Analysis was done using both descriptive and inferential statistics.Results: The findings of the study revealed that 46.7% expectant mothers had below average level of knowledge, 35% had average level of knowledge and 18.3% had good level of knowledge. 96.7 % had positive attitude and only 3.3 % had negative attitude towards epidural analgesia. Correlation between knowledge with attitude was to be significant (r=0.609; p=0.000).Conclusions: Thus, the study concluded that most of women had below average level of knowledge and but they showed positive attitude regarding epidural analgesia.
Solar light-facilitated oxytetracycline removal from the aqueous phase utilizing a H2O2/ZnWO4/CaO catalytic system
A CaO-supported ZnWO4 nanocomposite (ZnWO4/CaO) was successfully synthesized using a novel hydrothermal method and was characterized by scanning electron microscopy (SEM), tunnelling electron microscopy (TEM), X-ray diffraction (XRD), electron diffraction X-ray (EDX), Fourier transform infrared spectroscopy (FTIR) and UV–visible (UV–vis) spectral analysis. The ZnWO4/CaO composites exhibited rod-like morphologies with variable lengths from 45 nm to 147 nm and diameters from 26 nm to 36 nm. The catalytic efficiency of the synthesized ZnWO4/CaO composites was displayed for the photodegradation of oxytetracycline (OTC) antibiotic from the aqueous phase. The synergistic degradation of OTC was investigated in the presence of H2O2 and ZnWO4/CaO. The rate of photodegradation followed pseudo-first-order kinetics. The antibiotic removal was strongly influenced by the catalyst loading, H2O2 concentration, pH and OTC concentration. Using a solar/H2O2/ZnWO4/CaO catalytic system, 85% COD removal was attained for OTC degradation in 210 min. The oxidative degradation occurred through hydroxyl radicals. The prepared nanocomposites possessed high recyclability and were easily separated from the aqueous solution by a simple sedimentation process
Treatment of clavicle fracture using wise lock clavicle hook plate and wise lock superior anterior clavicle plate
Background: Clavicle fracture is common in adults associated with high non-union rate and post-operative complications. The aim of this prospective study was to reduce the postoperative complications in clavicle fracture (Type 15-A2 and 15-B1) by using wise lock plates (manufactured by Auxein Medical Private Limited).Methods: In this prospective study of 25 patients (11 patients had 15-A2 fracture, 14 patients had 15-B1 fracture) recruited with one year follows up period followed by physical exercises after one month of the surgery. The fractures were treated with two different plates: 3.5 mm wise lock clavicle hook plate and 3.5 mm wise lock superior anterior clavicle plate. X-ray was used to check the union, non-union. Functional outcome of the patients were assessed by the visual analogue scale (VAS) score at post-operative follow up at 4 weeks, 12 weeks, 6 months and 1 year.Results: Postoperative outcome was good with none of the patients showing non-union or delay in the union of fracture site. The encountered complication registered were residual pain which was mild (4 cases), and hypoesthesia (2 cases).Conclusions: Osteosynthesis of clavicle fracture with 3.5 mm diameter locking plates attributed as superior, anterior and hook plating system showed excellent results with low rate of complications
Correction to: Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst
Correction to: Bulletin of Chemical Reaction Engineering & Catalysis (2018), 13 (2): 227-235 (doi:10.9767/bcrec.13.2.1307.227-235)An error appeared in Corresponding Author in a paper entitled “Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst” published in Bulletin of Chemical Reaction Engineering & Catalysis. The Corresponding Author is corrected to be:* Corresponding Authors. Tel: +919415268192. Email: [email protected] (R. Prasad) Tel: +917505072607. Email: [email protected] (D. Yadav)——————The original article can be found online at: https://doi.org/10.9767/bcrec.13.2.1307.227-235——————Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).How to Cite: Singh, P., Yadav, D., Thakur, P., Pandey, J., Prasad, R. (2020). Correction to: Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 15 (2): 603-603 (doi:10.9767/bcrec.15.2.7659.603-603)Permalink/DOI: https://doi.org/10.9767/bcrec.15.2.7659.603-60
Studies on H2-Assisted Liquefied Petroleum Gas Reduction of NO over Ag/Al2O3 Catalyst
Hydrocarbon-Selective catalytic reduction (HC-SCR) is one of the potential methods to remove NOx emissions from diesel engine, lean burn petrol engines and natural gas engines exhaust. Ag/Al2O3 is a good catalyst for HC-SCR of NOx under lean-burn conditions. Further, addition of small amount of H2 is effective for enhancing HC-SCR activity. This effect is unique to silver and to specific Ag/support combinations, namely, Ag/γ-Al2O3. Various HC reductants, such as: octane, decane, dodecane and propane, have been reported in the literatures. Only a single study on LPG as a reductant over Cu-ZSM catalyst was reported. There was no work reported on H2 assisted LPG over Ag/Al2O3 catalyst. Thus, this gap in the literature is filled with the present investigation of NO reduction over 2 wt.% Ag/Al2O3 catalyst using LPG reductant. The fresh and used catalyst was characterized by various techniques like low temperature N2-adsorption, XRD, XPS and SEM. There was practically no change in the characteristics of the fresh and used catalyst. Two different reductants of CO and LPG were compared for SCR of NO over the catalyst without and with H2-assisted. The experiments were performed in a fixed bed tubular flow reactor under the following conditions: 100mg catalyst; 0.13% NO, 2.5% LPG/CO, 1% H2, 10% O2, rest Ar; total flow rate 60 mL/min; temperature ambient 400 oC and pressure 1 atm. Around 100% conversion of NO was achieved using LPG reductant. Light off temperature of NO reduction significantly reduced by H2assisted LPG reductant. The maximum conversion of NO with CO was limited to 35.15% at temperature of 224 oC and above. Whereas, 97.79 % NO conversion was achieved at 365 oC with LPG reductant. While, the maximum conversions with H2-LPG and H2-CO reductants were 100 and 99.46% at 117 and 220 oC, respectively. Therefore, H2-LPG-SCR of NOx over 2 wt.% Ag/Al2O3 catalyst system can be used to get 100% reduction at low temperature.
Two Dimensional Allotropes of Arsenene with Wide Range of High and Anisotropic Carrier Mobility
Considering the rapid development of experimental techniques for fabricating
2D materials in recent years, various monolayers are expected to be
experimentally realized in the near future. Motivated by the recent research
activities focused on the honeycomb arsenene monolayers, stability and carrier
mobility of non-honeycomb and porous allotropic arsenene are determined using
first principles calculations. In addition to five honeycomb structures of
arsenene, a total of eight other structures are considered in this study. An
extensive analysis comprising energetics, phonon spectra and mechanical
properties confirms that these structures are energetically and dynamically
stable. All these structures are semiconductors with a broad range of band gap
varying from ~1 eV to ~2.5 eV. Significantly, these monolayer allotropes
possess anisotropic carrier mobilities as high as several hundred
cm^{2}V^{-1}s^{-1} which is comparable with the well-known 2D materials such as
black phosphorene and monolayer MoS_{2}. Combining such broad band gaps and
superior carrier mobilities, these monolayer allotropes can be promising
candidates for the superior performance of the next generation nanoscale
devices. We further explore these monolayer allotropes for photocatalytic water
splitting and find that arsenene monolayers have potential for usage as visible
light driven photocatalytic water splitting.Comment: 31 pages, 8 figures, 3 table
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