AUTHOREA
Log in Sign Up Browse Preprints
BROWSE LOG IN SIGN UP

Preprints

Explore 11,964 preprints on the Authorea Preprint Repository

A preprint on Authorea can be a complete scientific manuscript submitted to a journal, an essay, a whitepaper, or a blog post. Preprints on Authorea can contain datasets, code, figures, interactive visualizations and computational notebooks.
Read more about preprints.

Space-time dynamics in monitoring neotropical fish communities using eDNA metabarcodi...
Naiara Sales
Owen S. Wangensteen

Naiara Sales

and 7 more

February 05, 2020
The biodiverse Neotropical ecoregion remains insufficiently assessed, poorly managed, and threatened by unregulated human activities. Novel, rapid and cost-effective DNA-based approaches are valuable to improve understanding of the biological communities and for biomonitoring in remote areas. Here, we evaluate the potential of environmental DNA (eDNA) metabarcoding for assessing the structure and distribution of fish communities by analysing sediments and water from 11 locations along the Jequitinhonha River catchment (Brazil). Each site was sampled twice, before and after a major rain event in a five-week period and fish diversity was estimated using high-through-put sequencing of 12S rRNA amplicons. In total, 252 Molecular Operational Taxonomic Units (MOTUs) and 34 fish species were recovered, including endemic, introduced, and previously unrecorded species for this basin. Spatio-temporal variation of fish assemblages was detected, richness during the first campaign was nearly twice as high as in the second sampling round; though peaks of diversity were primarily associated with only four locations. No correlation between β-diversity and longitudinal distance or presence of dams was detected, but low species richness observed at sites located near dams indicates that these anthropogenic barriers might have an impact on local fish diversity. Unexpectedly high α-diversity levels recorded at the river mouth suggest that these sections should be further evaluated as putative “eDNA reservoirs” for rapid monitoring. By uncovering spatio-temporal changes, unrecorded biodiversity components, and putative anthropogenic impacts on fish assemblages, we further strengthen the potential of eDNA metabarcoding as a biomonitoring tool, especially in regions often neglected or difficult to access.
ASSESSMENT OF NOISE LEVELS IN SELECTED AREAS WITHIN AKURE, NIGERIA METROPOLIS USING A...
Olumuyiwa Aderinola
Titilayo Owolabi

Olumuyiwa Aderinola

and 1 more

February 05, 2020
The study examined the noise levels in selected areas within Akure Metropolis, Nigeria with a view to generate noise maps using ArcGIS which will help to identify high impact areas and support environmental management in the study area. Some selected areas within Akure metropolis were selected for this study namely; Oja-oba Market (commercial Land use), Ijoka (Residential land use), and the Federal University of Technology, Akure (Futa as an Educational Land Use). The digital sound level meter (IEC651 Type 2) was used to measure noise level in the morning (8:00am-9:00am), afternoon (1:00pm-2:00pm) and evening (4:00pm-5:00pm) for a period of 7days in each of the selected areas. The compiled data were imported into the ArcGIS 10.5 Software for analysis and geo-referencing whereby transforming the data and presenting it on noise contour maps. The study revealed that Sunday bus stop has the highest mean noise level with 64.3 decibel (A) while the lowest noise level was found in Olowookere street with 38.1 dB(A) for the Residential area. Ijomu recorded the highest noise level with 78.6 dB(A) and Erekesan market has the lowest noise level of 61.5 dB(A) for the commercial area. Finally, Northgate has the highest noise level, which recorded 76.3 dB(A) and the lowest noise level was recorded at Library area with 41.0 dB(A) for the Institutional area. 80% of the commercial area is exposed to the highest risk of noise pollution. The residential area was exposed to 18.7% noise pollution which makes the area suitable for housing. The institutional land use recorded 36.6% for total area exposed to noise pollution. This research has provided valuable information for decision makers as a guidance for noise pollution risk management and serve as a reference for future noise limit regulations to be executed in urban areas of Nigeria and other developing countries
The homo/heterodimers of plasma membrane sugar transporters CsSWEET1a and CsSWEET17 m...
Lina Yao
Changqing Ding

Lina Yao

and 6 more

February 05, 2020
Sugars will eventually be exported transporters (SWEET) are involved in plant biological processes. CsSWEET1a and CsSWEET17, were found to be induced by cold acclimation in Camellia sinensis. Particularly, CsSWEET17 was differentially alternatively spliced and its inclusion/exclusion ratio was higher in the cold-resistant cultivar than in the cold-susceptible cultivars. Both CsSWEET1a and CsSWEET17 were located in the plasma membrane, and their interaction was confirmed using yeast two-hybrid and biomolecular fluorescence complementation. The C-terminal of the CsSWEET17, which was different from AtSWEET17, did not affect its plasma membrane localization but promoted its sugar transport activities. Overexpression (OE) of CsSWEET1a and CsSWEET17 resulted in an increased uptake of sugars in Arabidopsis, affecting plant germination and growth. The leaf and seed size of CsSWEET17-OE lines were significantly bigger than wild-type. Moreover, OE of CsSWEET1a and CsSWEET17 significantly reduced the relative electrolyte leakage levels under cold stress. Compared with those in wild-type, the expressions of AtCWINV genes were suppressed in both CsSWEET1a-OE and CsSWEET17-OE lines, indicating the alteration of sugar contents in the cell wall of OE lines. Our results suggest that CsSWEET1a and CsSWEET17 form homo/heterodimers in the plasma membrane to import sugars into the cytoplasm, thereby regulating plant growth and cold tolerance.
Geo-Hazards Assessment of Borrow Pits Excavation on the Environment
Titilayo Owolabi
KAYODE HASSAN LASISI

Titilayo Owolabi

and 4 more

February 05, 2020
Geo-environmental hazards associated with abandoned borrow pits in Nigeria are on the rise and a major concern to citizens, environmentalists and governments. Several highway failure spots are directly linked to the action of erosion initiated by active or abandoned (inactive) borrow pits situated close to the roads. This study examines the negative environmental impacts of the continuous removal of soil from borrow pits in some areas of Ado Ekiti, Nigeria. Four borrow pits were selected; two active sites and two abandoned sites. At inception, topographical and 3-Dimensional maps of the borrow pits were drawn and modelled. The area of the borrow pits and the volume of overburden excavated soils were calculated. The soil over burden pressure at the average height of the borrow pits were measured. The active borrow pit sites were checked again after two months to know the difference in the volume of overburden removed in the pit for that period. The volume of soil removed from borrow pit 1 (Active site), 2 (Active site), 3(Abandoned) and 4 (Abandoned) are 37000 m3, 34000 m3, 114000 m3 and 81000 m3 respectively. Environmental assessment of the study area through photographs showed prevalence of landslides, erosion, flooding, vegetation removal and structural failure. The volume of soil overburden removed from the abandoned borrow pit is more than the volume extracted from the active sites, this significant change in the value of overburden removed causes significant change to the terrain of the borrow pit. Some measures were then suggested to curb the problem occurring from the uncontrolled and indiscriminate borrow pits excavation thereby improving environmental sustainability. This study serves as a basis for government to put in place laws that help protect the environment from indiscriminate mining of borrow pits.
Effectiveness of a care plan based on the Roy adaptation model for fatigue and activi...
hojjat sheikhbardsiri
mohammad mahdi doustmohammadi

hojjat sheikhbardsiri

and 2 more

February 05, 2020
Abstract Rationale, aims, and objectives: Cardiac failure is one of the most common chronic diseases with high rate of morbidity and mortality. Fatigue and decreased ability to perform daily activities are of the most common complications of this disease. The purpose of this study was to determine effect of care plan based on Roy adaptation model on fatigue and daily activities in patients with heart failure. Methods: This clinical trial was performed on 60 heart failure patients admitted in two educational hospitals supervised by the Kerman University of Medical Sciences in 2019. Sample was randomly assigned into two intervention and control groups. The intervention group received the care plan through a face to face and group training program in 6 sessions at one month. Interval followed by a follow-up period for 4 weeks later, while the control group only received the regular services from hospital. Fatigue level was calculated based on piper fatigue scale and daily activities were calculated by Barthes scale. Results: finding indicated there was a significant difference between the two groups control and intervention after the intervention. Result showed that the intervention group had significantly lower mean scores in fatigue and higher mean scores in daily activities compared to the control group after intervention P ≤ .05. There was significant relationship between fatigue and daily activities of life with frequency of hospitalization and duration of disease in both groups P ≤ .05. Conclusion: Implementation of Roy model based education program as a low-cost, effective, and non-aggressive nursing intervention can affect fatigue and improve the ability to perform daily activities in patients with heart failure.
Runoff sequence feature extraction and prediction using an enhanced sparse autoencode...
Lipeng Qian
LI Junfeng

Lipeng Qian

and 4 more

February 05, 2020
For the prediction of the runoff sequence, owing to the non-stationariness and randomness of the sequence, the prediction accuracy of extreme runoff is not enough. In this study, the sparse factor of the loss function in a sparse autoencoder was enhanced using the inverse method of simulated annealing (ESA), and the runoff of the Kenswat Station in the Manas River Basin in northern Xinjiang, China, at 9:00, 15:00, and 20:00 daily during June, July, and August in 1998–2000 was considered as the study sequence. When the initial values of the sparse factor β are 5, 10, 15, 20, and 25, the experiment is designed with 60, 70, 80, 90, and 100 neurons, respectively, in the hidden layer to explore the relationship between the output characteristics of the hidden layer and the original runoff sequence after the network is trained with various sparse factors and different numbers of neurons in the hidden layer. Meanwhile, the orthogonal experimental groups ESA1, ESA2, ESA3, ESA4, and ESA5 were designed to predict the daily average runoff in September 2000 and compared with the prediction results of the support vector machine (SVM) and the feed forward neural network (FFNN). The results indicate that after the ESA training, the output of the hidden layer consists a large number of features of the original runoff sequence, and the boundaries of these features can reflect the runoff series with large changes.Meanwhile, the prediction results of the orthogonal experiment group indicate that when the number of neurons in the hidden layer is 90 and β0 = 15, the ESA has the best prediction effect on the sequence. In particular, the fitting effect on the day of “swelling up” of the runoff is more satisfactory than those of SVM and FFNN. The results are significant, as they provide a guide for exploring the evolution of the runoff under drought and flood as well as for optimally dispatching and managing water resources.
ENHANCED REFRACTIVE INDEX SENSOR BASED ON ETCHED CORELESS FIBER
Noor Hamza
hanan tahar

Noor Hamza

and 2 more

February 05, 2020
A high sensitivity refractive index (RI) sensor based on a multimode interference arises from the self-imaging effect in single-mode–multimode–single-mode fiber structure was experimentally demonstrated. The sensor performance with different coreless fiber diameter (CLF) was examined to obtain an appropriate dimension of extreme evanescent fields. Various diameters of CLF of 100 and 50 μm with three different tune lengths 20, 25 and 30 mm were achieved by chemical etching technique based on hydrofluoric (HF) acid plunging. The sensor performance is recognized by determining the spectral shift from the transmission spectrum for different values of refractive indices. The highest sensor sensitivity of about 1012 nm/RIU was attained when the CLF diameter was 50 μm. This sensor offers an appropriate and economical technique for applications of RI measurement.
A Novel Approach for Optimal Allocation of Series FACTS Device for Transmission Line...
Md Sarwar
Anwar Siddiqui

Md Sarwar

and 1 more

February 05, 2020
In competitive environment of electricity market, management of congestion has become utmost important so that the benefits of competitive electricity market remains intact. In this paper, one such scheme has been proposed to manage congestion efficiently. This has been accomplished by implementing TCSC at its optimal location as well as at its optimal parameter setting. Line flow sensitivity factor has been proposed to find the optimal location of TCSC. The optimal parameter setting of TCSC is obtained using particle swarm optimization algorithm. The optimal location and parameter setting of TCSC thus obtained with proposed method are validated through implementation of TCSC based on its minimum installation cost. Two different penalty factors for violation of system constraints are introduced to manage the congestion efficiently. The proposed method is tested on IEEE 30-bus system and IEEE 118-bus system. A 33-bus Indian network has also been considered to analyze the effectiveness of the proposed methodology.
Extraction modeling, kinetics and thermodynamics of solvent extraction of Irvingia ga...
Chinedu Agu
Matthew Menkiti

Chinedu Agu

and 3 more

February 05, 2020
Temperature, time and particle size effects on Irvingia gabonensis kernel oil (IGKO) yield, as well as the kinetics and thermodynamics parameters were investigated. Highest oil yield of 68.80 % (by weight) was obtained at 55 °C, 150 min., and 0.5 mm. Evaluated physicochemical properties of IGKO indicated that viscosity, acidity, dielectric strength, flash and pour points were 19.37 mm2s-1, 5.18 mg KOHg-1, 25.83 KV, 285 °C, and 17 °C, respectively, suggesting its feasibility as transformer fluid upon further treatment. Of the pseudo second order (PSO) and hyperbolic kinetic models studied, the former gave better fit to the experimental data. ∆H, ∆S and ∆G values of IGKO extraction at 0.5 mm and 328 K were, 251.81 KJ/mol, 1.08 KJ/mol and -105.49 KJ/mol, respectively, indicating the endothermic, irreversible and spontaneous nature of the process. Kinetic model equations that describe the process were successfully developed for both models based on the process parameters.
Production of ecofriendly bio-lubricant samples from palm kernel oil using different...
Chinedu Agu
Samuel   Egbuna

Chinedu Agu

and 4 more

February 05, 2020
This work focused on the chemical synthesis and characterization of palm kernel oil (PKO) for bio-lubricant production using transesterification of palm kernel methyl ester (PKME) with trimethylolpropane (TMP) and epoxidation-esterification methods. The PKO was extracted using solvent extraction method. The physicochemical characteristics of the PKO and produced bio-lubricant samples were determined using standard methods. Fourier Transform Infrared (FTIR) spectrometry and Gas Chromatographic analyses, were respectively, used to determine the predominant functional groups and fatty acids of PKO and the produced bio-lubricant samples. At 55 °C, 150 min and 0.5 mm particle size, kernel oil yield was 49.82 % (by weight). The viscosities at 40 °C, 100 °C, viscosity index, pour and flash points of the bio-lubricants produced by transesterification of TMP (PKBLT) and epoxidation-esterification (PKBLE) methods, were [42.53 cSt, 10.65 cSt, 139, - 11 °C, 235 °C] and [44.69 cSt, 11.42 cSt, 132, - 12 °C, 240 °C], respectively. Time, mole ratio and temperature effects were the main factors that significantly influenced the transesterification and epoxidation processes. The obtained physicochemical properties of PKBLE and PKBLT samples showed conformity with ISO VG 32 standard, hence, their possible application as bio-lubricant basestock.
Disentangling Conditional Effects of Multiple Regime Shifts on Atlantic Cod Productiv...
Tommi Perälä
Jeffrey Hutchings

Tommi Perälä

and 2 more

February 05, 2020
Regime shifts are increasingly prevalent in the ecological literature. However, definitions vary, and many detection methods are subjective. Here, we employ an operationally objective means of identifying regime shifts, using a Bayesian online change-point detection algorithm able to simultaneously identify shifts in the mean and(or) variance of time series data. We detected multiple regime shifts in long-term (59-154 years) patterns of coastal Norwegian Atlantic cod (>70% decline) and putative drivers of cod productivity: North Atlantic Oscillation (NAO); sea-surface temperature; zooplankton abundance; fishing mortality (F). The consequences of an environmental or climate-related regime shift on cod productivity are accentuated when regime shifts coincide, fishing mortality is high, and populations are small. The analyses suggest that increasing F increasingly sensitized cod in the mid 1970s and late 1990s to regime shifts in NAO, zooplankton abundance, and water temperature. Our work underscores the necessity of accounting for human-induced mortality in RS analyses of marine ecosystems.
Phylogenetic relatedness determines the strength of stable coexistence mechanisms in...
Verónica Zepeda
Carlos Martorell

Verónica Zepeda

and 1 more

February 05, 2020
Evolutionary relatedness may hinder stable coexistence due to similar niches and non-linear responses to competition. The mechanisms driving stability may respond differently to phylogenetic distance. Related species may be synchronic (have similar demographic responses over time), affecting fluctuation-dependent mechanisms: the storage effect should destabilize coexistence, and relative non-linearity (RNL) should be stronger due to increased fluctuations in competition. We tested these hypotheses using invasion analysis based on a model parameterized for 19 plant species from a semiarid grassland. Coexistence stability increased with phylogenetic distance. Stabilization through fluctuation-independent niche differentiation was stronger between distant relatives as a result of weaker competition. Synchronicity was higher between relatives, having the expected effects on SE and RNL. RNL was also strong between distant species probably due to different non-linear responses. Phylogenetic distance became more important as more species interacted, suggesting that evolutionary relatedness may be decisive in species-rich communities.
Improving Passenger Safety in Cars Using Novel Radar Signal Processing
Hajar Abedifirouzjaei
George Shaker

Hajar Abedifirouzjaei

and 2 more

February 05, 2020
We present a novel radar signal processing technique to identify the presence or absence of a living body in a vehicle using a mm-wave frequency-modulated continuous-wave radar. Unlike traditional detection methods which are mostly based on constant false alarm rate (CFAR), our proposed method extracts and monitors the consistent Doppler effect of received signals from the radar antenna resulting from the consistent breathing of living bodies over time. The proposed method works in all types of cars without the need for threshold definition for tracking as well as no need for training. Hence, the algorithm is more robust, accurate and fast. We assess our proposed signal processing with two phantoms mimicking the breathing of children and with adults in the vehicle in various conditions. The system has been proven to be robust in extensive studies over the course of multiple months.
Variability Effects on MHD for Blasius and Sakiadis Flows in the Presence of Dufour a...
Onyekachukwu Oyem
Winifred Mutuku

Onyekachukwu Oyem

and 2 more

February 05, 2020
A study is considered to a steady, two-dimensional boundary layer flow of an incompressible MHD fluid for the Blasius and Sakiadis flows about a flat plate in the presence of thermo-diffusion (Dufour) and thermal-diffusion (Soret) effects for variable parameters. The governing partial differential equations are transformed into a system of nonlinear ordinary differential equations using similarity variables. The transformed systems are solved numerically by Runge-Kutta Gills method with shooting techniques. The variations of the flow velocity, temperature and concentration as well as the characteristics of heat and mass transfer are presented graphically with tabulated results. The numerical computations show that thermal boundary layer thickness is found to be increased with increasing values of Eckert number (Ec), Prandtl number (Pr) and local Grashof number (Gr_x) for both Blasius and Sakiadis flow. The Blasius flow elevates the thickness of the thermal boundary layer compared with the Sakiadis flow. The local magnetic field has shown that flow is retarded in the boundary layer but enhances temperature and concentration distributions.
The deposition characteristics of coupled lead ions and suspended silicon powders alo...
Bing Bai
Jiaxi Zhang

Bing Bai

and 3 more

February 05, 2020
The deposition characteristics of lead ions (Pb2+) in the presence of silicon powders (SPs) were investigated in water seepage in a long one-dimensional sand column experiment. The injected SPs possess a very wide particle-size distribution (PSD). The concentrations of deposited Pb2+ and SPs and the migration distance along the water flow direction were measured by sampling. The PSDs of the deposited SPs in different sections were obtained by laser diffraction after transport test completion, and microstructure photos were also acquired through metallographic microscopy. Test results show that the presence of SPs may promote or inhibit Pb2+ migration, which is closely related to the concentration of injected Pb2+, particle size and concentration of injected SPs, seepage velocity, and change in the absolute zeta potential in the surface charge. Larger SPs are first deposited within a relatively short distance from the injection surface of the sand column compared with smaller SPs. The median diameter of the deposited SPs near the injection end is larger than that of the injected SPs and gradually decreases with increasing distance, which represents a clear particle-separation characteristic due to the flowing water.
Tree diversity effect on fine root biomass: overyielding via density dependence rathe...
Weixian Zeng
Wenhua Xiang

Weixian Zeng

and 8 more

February 04, 2020
Complementarity in resource use leading to increased resource partitioning is the most commonly proposed mechanism for explaining the positive relationship between plant diversity and productivity. However, we still have a poor understanding of the relationship between plant diversity and root biomass. We used molecular method to identify tree species and to estimate the biomass of fine root (≤ 2 mm in diameter) for each tree species in soil cores sampled from the plots along a tree species gradient elaborated in subtropical forests. Our objectives were to examine whether spatial resource partitioning and symmetric proliferation are responsible for the relationship between aboveground tree species richness (SRA) and fine root biomass. We found that increasing SRA led to higher fine root biomass and a support for symmetric proliferation strategies, but this pattern only appeared in nutrient-rich upper soil layer. Structural equation modelling (SEM) indicated that stand density was the dominant factor to mediate SRA effects on fine root biomass. Specifically, fine root biomass depended on the SRA × stand density interaction, with lower biomass at lower density and low richness, and this effect disappeared in higher density forests. Overall, we found inconsistent support for the vertical niche partitioning, indicating that greater soil volume filling is not the reason for belowground overyielding pattern. Alternatively, density-dependent biotic interactions affecting tree recruitment are an important driver affecting productivity in diverse subtropical forests but the usual root distribution patterns in line with the resource partitioning hypothesis are unrealistic in contexts where soil nutrients are heterogeneously distributed.
A novel interfacial induced nucleation and accurate self-seeding via membrane assiste...
Wu Xiao
Zeman He

Wu Xiao

and 6 more

February 04, 2020
Accurate cooling crystallization is vitally important in the production of highly specialized fine chemicals and pharmaceutical engineering, etc. Herein, a novel hollow fiber membrane-assisted cooling crystallization (MACC) was developed to achieve precise nucleation and self-seeding process control. Poly-tetrafluoroethylene (PTFE) and polyethersulfone (PES) membrane with diverse interfacial induced nucleation and thermal conduction properties were introduced to accelerate the nucleation and then transfer the automatically detached crystal seed into the crystallizer. Polymeric membrane can dominate the nucleation kinetic and hinder the secondary nucleation, which was validated from the theoretical model and on-line detective experiments. The crystal product manufactured by MACC possessed better morphology, larger mean size (>1.35 mm), higher purity (>99.5 wt%) and narrower size distribution than the conventional cooling crystallization. Space-time process decoupling between nucleation and crystal growth can be realized via auto-screening uniform nuclei in the membrane modules and controllable growth in the crystallizer during MACC.
High temperature-responsive poplar lncRNAs modulate target gene expression by RNA int...
Yuepeng Song
Panfei Chen

Yuepeng Song

and 4 more

February 04, 2020
High temperature stress increasingly threatens plant development and survival. Long noncoding RNAs (lncRNAs) participate in plant stress responses, but their functions in the complex stress-responsive network remain elusive. Poplar is one of the most widely planted trees in the world and contributes to terrestrial ecological stability. In this study, we identified 261 high temperature-responsive lncRNAs in poplar (Populus simonii). These lncRNAs were predicted to target a total of 353 target genes of which 163 are cis-targets and 190 trans-targets. To determine the function of select heat-responsive lncRNAs, transient overexpressed and repressed lncRNA were implemented in poplar leaves and roots. As expected, the abundance of lncRNA target transcripts were altered. One such lncRNA TCONS_00202587 binds to upstream sequences of targets via its secondary structure and interfere with the target gene transcription. Another lncRNA TCONS_00260893 could enhance Ca2+ influx in response to high-temperature treatment by interfering with a specific variant/isoform of the target gene. Two lncRNA targets overexpressed experiment revealed heat tolerance in Arabidopsis. These results revealed lncRNAs could regulate their targets genes by acting as potential RNA scaffolds or through RNA interference pathway. It is indicated a new layers of highly complex RNA-based gene regulation in heat tolerance of perennial plants.
Exogenously-supplied trehalose protects photosystem II by promoting cyclic electron f...
Yin Luo
Dan He

Yin Luo

and 3 more

February 04, 2020
Trehalose protects and stabilizes the reaction center and improves photosystem II (PS II) activity. However, the underlying mechanism remains unknown. Cyclic electron flow is an important mechanism to protect PS II under stress. This study focused on the effects of exogenous trehalose on the activity of PS II, D1 protein content, the plastoquinone (PQ) pool, and ATP synthase activity in wheat seedlings under heat and drought stress to explore the relationship between trehalose and cyclic electron flow (CEF). Our experimental results indicated that heat and drought stress decreased the maximal photochemical efficiency of PS II (Fv/Fm) and the electron transport rate of PS II (EFR(II)), whereas the trehalose pretreatment improved photochemical efficiency and the electron transport rate of PS II. The trehalose pretreatment stimulated CEF under heat and drought stress. Furthermore, the proton gradient (ΔpH) across the thylakoid membrane and ATPase activity increased. The higher ΔpH and ATPase activity played a key role in protecting PS II under stress. Inhibition of the oxidized PQ pool caused by heat and drought stress was alleviated by the trehalose pretreatment. Thus, our results show that photoinhibition of heat and drought-stressed plants was alleviated by the trehalose pretreatment. Our findings further reveal that this effect was mediated by CEF and the PQ pool.
Immobilization of lipase onto metal-organic frameworks for enantioselective hydrolysi...
Xin Yuan
Yu Liu

Xin Yuan

and 5 more

February 04, 2020
Enzyme immobilization enhances the catalytic activity and stability of the enzyme, and also improves reusability. Metal organic frameworks (MOFs), which possess diversified structures and porosity, have been used as excellent carriers for enzyme immobilization. Pseudomonas fluorescens lipase (PFL) has been successfully immobilized onto MOFs by covalent cross-linking to obtain a series of immobilized lipase (PFL@MOFs). PFL@MOFs are used for catalytic enantioselective hydrolysis of 2-(4-hydroxyphenyl) propionic acid ethyl ester enantiomers (2-HPPAEE) in aqueous medium and transesterification of 4-methoxymandelic acid enantiomers (4-MMA) in organic medium. The experimental results indicated that PFL@Uio-66(Zr) exhibits excellent enzymatic catalysis performances and high enantioselectives. In addition, to increase catalytic activity and reusability, PFL is modified by the polyethylene glycol (PEG) to prepare PEG-modified lipase (PFL-PEG), then PFL-PEG is immobilized onto Uio-66(Zr) to prepare PFL-PEG@Uio-66(Zr), demonstrating better reusability and catalytic activity compared with PFL@Uio-66(Zr).
The effect of surface properties on the formation of Scenedesmus rubescens biofilm

February 04, 2020
A document by Vasiliki Tsavatopoulou, written on Authorea.
Mathematical modeling of volatile organic compounds removal over activated carbon
Yadollah Tavan
Hossein Bahmanyar

Yadollah Tavan

and 2 more

February 04, 2020
Removal of volatile organic compounds (VOC) from air is essential due to health issues. An industrial cyclic temperature swing adsorption (TSA) unit is investigated over activated carbon. The comparison of industrial data with that of model showed good agreement between them. The results showed that ethanol is more adsorbed on activated carbon than diethyl ether and outlet concentration of diethyl ether exceeds its inlet concentration due to its partial replacement by ethanol. Performance of the TSA unit is measured through calculating diethyl ether and ethanol recoveries. Moreover, an energy requirement is also added into the model and multi-objective optimization has been carried out. High model accuracy of 99.98 % is obtained for objectives indicating a good fitting. The suggested optimum variables wereduration of heating stepas 30min, duration of cooling stepas 20 min, regeneration flow rate of 400 kmol/h and humidity of 0.001 in air.
The effect of a specific protocol to shorten the decision-to-delivery interval for em...
Dittakarn Boriboonhirunsarn
Prasert Sunsaneevithayakul

Dittakarn Boriboonhirunsarn

and 2 more

February 04, 2020
Rationale, aims and objectives: In emergency cesarean section, time from decision to delivery should be within 30 minutes. This study aims to compare decision-to-delivery interval (DDI) in emergency cesarean section before and after the implementation of a specific care process improvement protocol (“code blue”). Methods: 300 women underwent emergency cesarean section were included. Study and comparison group were 150 women before and 150 women after “code blue” protocol implementation. Medical records were reviewed for clinical information. Timing of decision-to-delivery process was compared. Results: Maternal age, parity, and GA at delivery were comparable between the 2 groups. The most common indication was abnormal FHR in NICHD category III in both groups. Median DDI was significantly shorter in study than comparison group (22 vs. 52.5 minutes, p<0.001). In addition, median decision-to-room and decision-to incision intervals were also significantly shorter (8 vs. 25 minutes and 18 vs. 45 minutes, p<0.001, respectively). Women in study group had significantly higher rate of DDI ≤30 minutes than in comparison group (80% vs. 8%, p<0.001). Similar significant differences of each time interval and rate of DDI ≤30 minutes between the 2 groups were observed regardless of decision time. Only 5 (3.3%) of women in study group had DDI >75 minutes compared to 13 cases (25%) in comparison group (p<0.001). Pregnancy and neonatal outcomes were comparable between the 2 groups. Conclusion: The implementation of “code blue” protocol for emergency cesarean section results in significantly shorter DDI and other time intervals.
Engineering trienoic fatty acids into cottonseed oil improves low-temperature seed ge...
Lihong Gao
Wei Chen

Lihong Gao

and 14 more

February 04, 2020
Alpha-linolenic acid (ALA, 18:3∆9,12,15) and γ-linolenic acid (GLA, 18:3∆6,9,12) are important trienoic fatty acids which are beneficial for human health in their own right, or as precursors for the biosynthesis of long chain polyunsaturated fatty acids. ALA and GLA in seed oil are synthesized from linoleic acid (LA, 18:2∆9,12) by the microsomal ω-3 fatty acid desaturase (FAD3) and ∆6 desaturase (D6D), respectively. Cotton (Gossypium hirsutum L.) seed oil composition was modified by transforming with a FAD3 gene from Brassica napus and a D6D gene from Echium plantagineum, resulting in approximately 30% ALA and 20% GLA, respectively. The total oil content in transgenic seeds remained unaltered relative to parental seeds. Despite the use of a seed-specific promoter for transgene expression, low levels of GLA and increased levels of ALA were found in non-seed cotton tissues. At low temperature the germinating cottonseeds containing the linolenic acid isomers elongated faster than the untransformed controls. ALA-producing lines also showed higher photosynthetic rates at cooler temperature and better fibre quality compared to both untransformed controls and GLA-producing lines. The oxidative stability of the novel cottonseed oils was assessed, providing guidance for potential food, pharmaceutical and industrial applications of these oils.
← Previous 1 2 … 452 453 454 455 456 457 458 459 460 … 498 499 Next →
Authorea
  • Home
  • About
  • Product
  • Preprints
  • Pricing
  • Blog
  • Twitter
  • Help
  • Terms