One-step System Research Articles

Bacteria-laden microgels as autonomous three-dimensional environments for stem cell engineering.

A one-step microfluidic system is developed in this study which enables the encapsulation of stem cells and genetically engineered non-pathogenic bacteria into a so-called three-dimensional (3D) pearl lace–like microgel of alginate with high level of monodispersity and cell viability. The alginate-based microgel constitutes living materials that control stem cell differentiation in either an autonomous or heteronomous manner. The bacteria (Lactococcus lactis) encapsulated within the construct surface display adhesion fragments (III7-10 fragment of human fibronectin) for integrin binding while secreting growth factors (recombinant human bone morphogenetic protein-2) to induce osteogenic differentiation of human bone marrow–derived mesenchymal stem cells. We concentrate on interlinked pearl lace microgels that enabled us to prototype a low-cost 3D bioprinting platform with highly tunable properties.

Do emigrants’ remittances cause Dutch disease? A developing countries case study

Although the positive socio-economic effects of remittances for recipient countries in the short term are unmistakable, inflows of remittances may at the same time exert adverse effects on the trade competitiveness of an economy, by appreciating the real exchange rate. This phenomenon is characterised as an instance of the ‘Dutch disease’ – the negative impact of windfall revenue inflows on the competitiveness of other tradable sectors and hence on overall economic growth. While the real effect of workers’ remittances on real exchange rates in a recipient economy is still a controversial issue, several studies have analysed evidence for the existence of the ‘Dutch disease’ phenomenon in various sets of countries. The main objective of this study is to examine whether remittance flows have had any adverse effect on the international trade competitiveness of a selected group of developing countries during the period from 1995 to 2014. Using a one-step system Generalised Method of Moments specification within a simultaneous equation approach, it shows that remittance flows depreciate the real exchange rate at their levels and that the lagged value of remittances create the Dutch disease for this country group. In addition, we confirm that while trade openness and world real interest rates contribute to a depreciation in real exchange rates, gross domestic product per capita and net Official Development Aid inflows tend to appreciate real exchange rates. A policy implication is that trade liberalisation policies that lower tariff rates on capital imports and new export-oriented incentive programmes should be accompanied by measures designed to prevent appreciation in the real exchange rate: steps in this direction such as recent macroeconomic and prudential capital flow management initiatives are briefly referenced.JEL Codes: F20, F21, F22, F23

Grafting Methyl Methacrylate onto Silk via Emulsion Graft Copolymerization Using a Diethylzinc Complex Initiator

Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator to monomer ratio. Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TGA), and scanning electron microscopy (SEC) techniques were used to characterize the structure, thermal stability, and surface morphology of the obtained product, respectively. Grafting of MMA onto silk increased the thermal stability of silk. The FTIR spectrum and SEM images provided further evidence that MMA has been successfully grafted onto the silk fiber. A peak ascribed to the C=O stretching vibration of MMA was detected in the FTIR spectrum of grafted silk fiber, which was not present in the spectrum of pure silk fiber. Moreover, the SEM images illustrated the increase in diameter and surface roughness of grafted silk compared with pure silk. Lastly, the dyeing performance of the modified silk was significantly increased.

171 Effect of progesterone and prolactin on the developmental competence of bovine oocytes during the terminal phase of in vitro maturation

To date, considerable progress has been achieved in in vitro production (IVP) technologies in cattle; however, developmental potentials of oocytes matured in vitro remain low compared with in vivo-matured oocytes. Thus, a better understanding of different aspects of oocyte maturation may allow us to increase the embryo development rate. Our study was aimed to assess the effects of progesterone (P4) and prolactin (PRL) on the bovine oocyte developmental competence. Bovine cumulus-enclosed oocytes (CEO) were matured using either one-step or two-step maturation conditions. For the one-step protocol, CEO were cultured for 24h in TCM-199 supplemented with 10% fetal calf serum (FCS), 10μg mL−1 porcine FSH, and 10μg mL−1 ovine LH (standard medium). For the two-step procedure, CEO were first cultured for 16h in the standard medium (n=1263) and then transferred to 1 of 3 experimental media and cultured for additional 8h in either absence or presence of either P4 (50 ng mL−1) or bovine PRL (50ng mL−1). The 3 media tested in the two-step maturation were (1) TCM-199 containing 10% FCS (group 1), (2) TCM-199 containing 3mg mL−1 BSA (group 2), or (3) Fert-TALP medium supplemented with 6mg mL−1 BSA (group 3). Fert-TALP was selected because it can potentially be used throughout maturation and fertilization. Following in vitro maturation, all oocytes underwent an IVF/in vitro culture procedure as described previously (Singina et al. 2014 Reprod. Fertil. Devel. 26, 154). The embryo development was evaluated at Days 2 and 7 for cleavage and blastocyst rates. In addition, obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using 4′,6-diamidino-2-phenylindole (DAPI) and TUNEL staining. The data from 4 to 5 replicates (113-159 oocytes per treatment) were analysed by ANOVA. For oocytes matured for 24h in the one-step culture, the cleavage rate, blastocyst rate, total cell number, and apoptotic nuclei per blastocyst were 66.1±1.1, 23.7±2.0, 71.4±9.1, and 4.8±1.2%, respectively. For the two-step culture, the cleavage rate did not differ from that of the one-step culture system, ranging from 64.8 to 76.5%. Also, no effects of the two-step systems were observed on total cell number (63.0-78.8) or the proportion of apoptotic nuclei (3.3-5.3%) at the blastocyst stage. The culture of CEO in group 1 (without the supplements) had a reduced blastocyst rate (17.4±0.4%; P<0.05) compared with the standard one-step maturation group, and the addition of P4 (but not PRL) improved the blastocyst yield (P<0.05). Furthermore, when P4 (but not PRL) was added to group 2 and group 3 media, blastocyst rates increased significantly (32.9±3.1 and 32.8±2.7%, respectively) compared with those of the one-step group (P<0.05), but did not differ from those of untreated groups 2 and 3 (26.2±2.7 and 30.0±3.0%, respectively). Our data indicate that P4 supplementation during the terminal phase of two-step IVM can enhance the developmental competence of bovine oocytes and that the nature of this effect depends on the composition of IVM medium, whereas no effect of PRL supplementation was observed. The study was supported by RFBR (No. 17-29-08035).

Impact of oil and gas prices shocks on banks’ deposits in an oil and gas-rich economy

PurposeThe purpose of this paper is to investigate and compare the impact of oil and gas prices changes on bank deposits at the aggregate as well as at the level of commercial and Islamic banks in Qatar over the period 2000–2016.Design/methodology/approachUsing the BankScope Database as well as bank-level balance sheet and financial statements data, the authors use one-step system GMM dynamic model to examine and compare the association between oil and gas prices changes with bank deposits in Qatar. The authors also test hypotheses of direct and indirect impacts of oil and gas prices changes on bank deposits.FindingsThe results indicate that oil and gas prices changes have a direct impact on deposits of banks at the aggregate level in Qatar. However, the authors find that oil and gas price changes significantly affect deposits of Qatari commercial banks directly prompting enhanced lending by banks and the consequent business activities in the economy, while their impact on the deposits of Qatari Islamic banks is indirect, i.e. the impact is permeated through the macroeconomic and institutional characteristics of the country that are reinforced by the growing expectations and commercial sentiment of the country. The authors find that significant association between oil price changes and deposit growth during the global financial crisis 2008 has been distorted. However, the authors find that there was a sharp rise in the deposits of Islamic banks during the period of global financial crisis.Practical implicationsThe results of this study necessitate policy measures that can counter the effects of changes in oil and gas prices on the effectiveness of bank deposits.Originality/valueIt is widely recognized that oil and gas prices and the level of production are of great importance to the economic development of oil and gas exporting countries. So far, however, no econometric study has been reported in the literature which analyses and compares the impact of oil and gas prices changes on bank deposits of commercial and Islamic banks and also at the aggregate level in any of the oil-exporting economies. Thus, this study provides the first empirical evidence on distinct direct and indirect channels through which oil and gas prices changes may affect bank deposits.

Additivity of nonlinear tree crown width models: Aggregated and disaggregated model structures using nonlinear simultaneous equations

A tree crown is a mass of foliage and significantly correlated to biomass and growth of other parts of a tree. Crown width (CW) is defined as an average of two crown diameters perpendicular to each other, obtained from measurements of four crown radii (crown components). The CW is often used as a covariate predictor in various forest models and therefore, its accurate estimate can be useful for forest management. Although various CW models have been developed so far, all of them lack a detailed investigation of the additivity properties of crown components and inherent correlations among the components and total CW. This study compared three alternative procedures of developing the systems of CW models: nonlinear simultaneous equations (NSE), disaggregated model structure with both one-step proportional weighting system (DMS&OSPWS), and two-step proportional weighting system, and aggregated model structure with one constraint on the total CW. Other two commonly used additivity methods: adjustment in proportion and ordinary least square with separating regression were also evaluated. The comparisons were based on the analyses of data obtained from 2207 trees of Mongolianoak (Quercus mongolica Fisch.) on 116 permanent sample plots located in northern China. Results showed that each method ensured a summation of crown components equal to twice as much as the total CW. The NSE better accounted for the inherent correlations among the crown components and total CW. Out of the model structures evaluated, DMS&OSPWS provided the best performance. This article emphasized more on the methodology and it was expected that the method could be applied by other researchers to develop similar systems of the CW models for other species as well.

Comprehensive Analysis of System Calibration between Optical Camera and Range Finder

This paper describes the comprehensive analysis of system calibration between an optical camera and a range finder. The results suggest guidelines for accurate and efficient system calibration enabling high-quality data fusion. First, self-calibration procedures were carried out using a testbed designed for both the optical camera and range finder. The interior orientation parameters of the utilized sensors were precisely computed. Afterwards, 92 system calibration experiments were carried out according to different approaches and data configurations. For comparison of the various experimental results, two measures, namely the matching rate of fusion data and the standard deviation of relative orientation parameters derived after system calibration procedures, were considered. Among the 92 experimental cases, the best result (the matching rate of 99.08%) was shown for the use of the one-step system calibration method and six datasets from multiple columns. Also, the root mean square values of the residuals after the self- and system calibrations were less than 0.8 and 0.6 pixels, respectively. In an overall evaluation, it was confirmed that the one-step system calibration method using four or more datasets provided more stable and accurate relative orientation parameters and data fusion results than the other cases.

Impact of oil and gas price shocks on the non-performing loans of banks in an oil and gas-rich economy

PurposeThe purpose of this paper is to examine and compare the impact of oil and gas prices shocks on the non-performing loans (NPLs) of banks at the aggregate as well as at the level of commercial and Islamic banks in Qatar over the period 2000-2016.Design/methodology/approachUsing the West Texas Intermediate Database, BankScope Database, World Bank’s World Development Indicators Database, and International Monetary Fund Database, the authors use a one-step system generalized method of moments dynamic model to examine and compare the association between oil and gas prices shocks with NPLs in Qatari banks. The authors also test the hypotheses of direct and indirect impacts of oil price shocks and gas price shocks on bank NPLs.FindingsThe results indicate that oil price shocks and gas price shocks do not have directly affect NPLs of Qatari banks at the aggregate level, while they have indirect effects that are channeled through the country-specific macroeconomic and institutional factors. The authors find that oil and gas prices shocks affect NPLs of Qatari Islamic banks directly through extended oil and gas-related cash flows, while their impact on the NPLs of Qatari commercial banks is indirect. In other words, Islamic banks in Qatar greatly benefits from increased cash flow caused by the rise in the oil and gas prices, which make their NPLs, much lower than that in commercial banks. Better capital cushion, better managerial efficiency, better risk management, and liquidity management systems should be used by the Islamic banks in Qatar to expand their customer base. The authors also find that positive fiscal stance of the government reduces the NPLs in both commercial and Islamic banks.Practical implicationsThe results of this study necessitate policy measures that can counter the effects of changes in oil and gas prices on the growth of bank NPLs.Originality/valueIt is widely recognized that oil and gas prices and the level of production are of great importance to the economic development of oil and gas-exporting countries. So far, however, no econometric study has been reported in the literature which analyses and compares the impact of oil and gas prices shocks on the NPLs of commercial and Islamic banks and also at the aggregate level in any of the oil economies. Thus, this study provides the first empirical evidence on distinct direct and indirect channels through which oil and gas prices shocks may affect bank NPLs.

Effect of two-step and one-step surface conditioning of glass ceramic on adhesion strength of orthodontic bracket and effect of thermo-cycling on adhesion strength.

The adhesion strength of orthodontic brackets bonded to dental glass ceramics was evaluated after ceramic surface was treated with two-step and one-step surface conditioning systems, and subjecting to thermo-cycling. A total of forty specimens were fabricated from silica based glass ceramic (lithium disilicate) by duplicating the buccal surface of maxillary first premolar. The specimens were randomly assigned to two experimental groups (n = 20), group one specimens were treated with two-step surface conditioning system (IPS ceramic etching gel™ and Monobond plus™) and group two specimens were treated with one-step surface conditioning system (Monobond etch and prime™). The surface roughness of the specimens after treatment with two-step and one-step surface conditioning system was measured using non-contact surface profilometer. Ten randomly selected specimens from each group were subjected to thermo-cycling and the remaining ten served as baseline. The shear bond strength of the specimens was measured using universal material testing machine. The adhesive remnant index score was calculated, and the results of surface roughness and bond strength were tabulated and subjected to analysis of variance and post hoc tukey's test at a significance level of p < 0.05. The results of the study showed that the specimens treated with two-step conditioning system had higher surface roughness and bond strength than one-step conditioning system. The majority of the specimens treated with both two-step and one-step conditioned specimens showed adhesive failure after subjecting thermo-cycling. Traditional two-step conditioning provides better bond strength. The clinical importance of the study is that, the silane promoted adhesion significantly reduces on exposure to thermo-cycling.

Inequality and Economic Growth in Indonesia in The 2000’s

The income inequality in Indonesia reached the highest level during the decentralization era and suspected to be the cause of the slowdown of the economic growth in the last five years to 2015. This paper investigates whether increasing inequality had a positive or negative impact on economic growth in Indonesia. Using dynamic panel and applying Generalized Method of Moments (GMM) estimator, the result concluded that there is a significant positive relationship between income inequality and economic growth. However, this study cannot draw a definite conclusion about the association for the different classes (bottom, middle, and top level) since only one-step system GMM is significant. Based on the result, it implies that the government should be more careful in regulating the inequality policy and understand more about the right mechanism of inequality and economy growth.DOI: 10.15408/sjie.v7i2.6177

A Simple and Rapid Gene Disruption Strategy in Mycobacterium abscessus: On the Design and Application of Glycopeptidolipid Mutants.

Little is known about the disease-causing genetic determinants that are used by Mycobacterium abscessus, increasingly acknowledged as an important emerging pathogen, notably in cystic fibrosis. The presence or absence of surface exposed glycopeptidolipids (GPL) conditions the smooth (S) or rough (R) M. abscessus subsp. abscessus (M. abscessus) variants, respectively, which are characterized by distinct infective programs. However, only a handful of successful gene knock-out and conditional mutants have been reported in M. abscessus, testifying that genetic manipulation of this mycobacterium is difficult. To facilitate gene disruption and generation of conditional mutants in M. abscessus, we have designed a one-step single cross-over system that allows the rapid and simple generation of such mutants. Cloning of as small as 300 bp of the target gene allows for efficient homologous recombination to occur without additional exogenous recombination-promoting factors. The presence of tdTomato on the plasmids allows easily sifting out the large background of mutants spontaneously resistant to antibiotics. Using this strategy in the S genetic background and the target gene mmpL4a, necessary for GPL synthesis and transport, nearly 100% of red fluorescent clones exhibited a rough morphotype and lost GPL on the surface, suggesting that most red fluorescent colonies obtained after transformation incorporated the plasmid through homologous recombination into the chromosome. This system was further exploited to generate another strain with reduced GPL levels to explore how the presence of these cell wall-associated glycolipids influences M. abscessus hydrophobicity as well as virulence in the zebrafish model of infection. This mutant exhibited a more pronounced killing phenotype in zebrafish embryos compared to its S progenitor and this effect correlated with the production of abscesses in the central nervous system. Overall, these results suggest that the near-complete absence of GPL on the bacterial surface is a necessary condition for optimal pathogenesis of this mycobacterium. They also suggest that GPL content affects hydrophobicity of M. abscessus, potentially altering the aerosol transmission, which is of particular importance from an epidemiological and clinical perspective.

The evaluation of surface sealants' effect on the color stability of Nano-hybrid composite after polishing with One-Step system (in-vitro).

BackgroundThe clinical use of composite resins has increased substantially over the past few years due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. An alternative for preventing or reducing composite discoloration is using of composite surface sealant. The purpose of this study was to determine the effect of surface sealant on color-stability of Nano-hybrid composites after polishing with one-step system.Material and Methods56 disk-shaped specimens (10*2 mm) of a Nano-hybrid composite resin (VOCO,Cuxhaven,Germany) were prepared. The specimens were randomly divided in to 2 groups of 28 specimens each. The surfaces of specimens were polished with One-step system (Dimanto,VOCO,Germany ). one group of specimens assigned as control group and received no more surface treatment .surface sealant (PermaSeal,Ultradent,USA) was applied on the surface of specimens of the other group as experimental group .specimens were stored in Ringer’s solution for 24 hours at 37oC. The specimens were subjected to artificial aging with thermocycling method between coffee solution at 55°C and Ringer’s solution at 5°C for 3000 cycles. CIE L*a*b color coordinates were established using a spectrophotometer for each specimen. Statistical significance was set at p<0.05.ResultsAfter aging in both groups, color changing was significantly different (p<0.05) and clinically unacceptable (ΔE> 3.3) and there was no significant difference between the two groups in ΔE.ConclusionsSurface sealant was not effective in improving color stability. Key words:Surface-penetrating Sealant, Color Stability, Nano-hybrid composites.

Research Article One-Step RT-qPCR assay for detection and quantification of equine infectious anemia virus &lt;em&gt;in-vitro&lt;/em&gt;

Equine infectious anemia virus (EIAV) infection often results in an initial febrile response, followed by recurrent cycles of the disease and finally, a prolonged asymptomatic period. These variations in clinical signs are due to a number of factors, including virus strain, equid species and differences in susceptibility among animals. As a consequence of the close relation between viral strain and disease, studies about in-vitro replication and fitness of EIAV in macrophages, which are the target cells of the virus, depend on accurate measurement of viral load throughout the infection period. We developed a method to quantify EIAV in-vitro using a one-step RT-qPCR system from a control RNA synthesized for this purpose. Designed primers amplified a 520 base pair fragment from the gag gene region that was inserted into a pGEM-T Easy Vector plasmid and propagated in Escherichia coli DH5-α.The bacteria with the construct were propagated and sufficient quantities of the template DNA were produced. The RNA was synthesized in-vitro from the plasmid linearization product and was used for standardization of a one-step RT-qPCR system with a minimum detection limit of 10 to 15 molecules. The efficiency of the reaction was 101%, with r2 equal to 0.997. This new method can be used for the determination of virus titer in EIAV replication studies in-vitro.

The evaluation of surface sealants' effect on the surface roughness of Nano-hybrid composite after polishing with One-Step system (in-vitro).

BackgroundThe clinical use of composite resins has increased substantially due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. Use of surface sealants is recommended to improve surface smoothness of composite restorations. The aim of this study was to evaluate the effect of surface sealants on the surface roughness of nano-hybrid composite after polishing with One-Step system.Material and MethodsUsing a silicon mold, 56 specimens of 10 mm diameter and 2 mm height were prepared from Grandio nano-hybrid composite (Voco, Cuxhaven, Germany) with A2 shade. Specimens were randomly divided in 2 groups. The surface of specimens were polished with VOCO One-step system. One group of specimens assigned as control group and received no more surface treatment. Surface sealant PermaSeal (Ultradent, USA) was applied on the surface of specimens of the other group as experimental group. Specimens were stored in Ringer’s solution at 37°C for 24 hours. The specimens were subjected to artificial accelerated aging with thermocycling method (3000 cycles, between 5 and 55°C) and then 100000 cycles of tooth brushing. A Profilometer was used to measuring the surface roughness of specimens before and after aging procedures.ResultsThe surface roughness changes of control group were significant before and after aging (P<0.05). The mean final surface roughness of control group was unacceptable clinically while it was acceptable in experimental group.ConclusionsThe use of surface sealants on nano-hybrid composite causes noticeable reduces in surface roughness of composite. Key words:Surface-penetrating sealant, surface roughness, nano-hybrid, composites, one-step polishing.

Use of "Surface Analyzer" to evaluate the Effect of Two Polishing Systems on Surface Texture of Four Newer Composites.

Composites polymerized with a clear matrix on the surface will leave a resin-rich surface layer that is easily abraded in the oral environment, exposing unpolished, rough, inorganic filler material. The purpose of this study was to evaluate the polishing effect of two different polishing systems: One-step (PoGo) system and Sof-Lex (multistep) system on four different resin composites: Synergy D6, Clearfil APX Esthetics, Filtek Z 350 XT, Ceram X Mono. After polishing, the specimens were analyzed for average surface roughness using a two-dimensional surface profilometer.How to cite this article: Garg S, Goel M, Verma S, Mahajan N, Kaul B, Garg V. Use of “Surface Analyzer” to evaluate the Effect of Two Polishing Systems on Surface Texture of Four Newer Composites. Int J Clin Pediatr Dent 2018;11(4):266-270.

Removal of tetrachloroethene from polluted air by activated sludge

ABSTRACT A one-step technological system containing activated sludge fed with synthetic domestic wastewater was applied to treat waste air polluted with tetrachloroethene (PCE). In the first stage of the experiment, air passed through a bioscrubber; in the second and third stages, it passed through the bioreactor containing activated sludge and bacteria immobilised in oak chips. These bacteria are active in PCE biodegradation. Process efficiency in the final stage of the experiment was high; the elimination capacity was 0.23 g m−3 h−1 with the PCE mass loading rate of 0.58 g m−3 h−1. It has been shown that in the activated sludge bioreactor, bacteria adapted to PCE biodegradation and the wood chips protected microorganisms from the toxic effects of pollution. The dominant strains of bacteria immobilised in wood chips have been identified. Most of them were Gram-negative rods – Pseudomonas aeruginosa, Pseudomonas putida, Ralstonia pickettii and Ochrobactrum anthropii. Only one strain was Gram-positive and of cylindrical shape. The results of the study indicate the potential of immobilised bacteria capable of degrading chlorinated aliphatic hydrocarbons for the air and wastewater treatment. The low cost of the treatment process is an advantage.

One-Step Synthesis of N-Heterocyclic Compounds from Carbohydrates over Tungsten-Based Catalysts

A one-step reaction system has been developed to convert glucose and other renewable carbohydrates into important N-heterocyclic compounds in ammonia solution. Under optimal conditions, 2-methyl pyrazine (MP) and 4(5)-methyl imidazole (MI) were produced within 15 min with combined yields of around 40%. While the formation of 4(5)-MI was identified as a non-catalytic process, the yield of 2-MP was highly influenced by the presence of catalysts. In particular, nearly three-fold yield enhancement of 2-MP was achieved over several tungsten-based catalysts. Control experiments, isotope-labelling tests, ESI-MS, and NMR analysis revealed that the formation of 2-MP follows a fragmentation mechanism, while small tungsten clusters such as [HW2O7]- and [W4O13]2- were the catalytically active species facilitating both glucose fragmentation and the subsequent cyclization reaction to generate pyrazine rings. The work exemplifies the possibility of sustainable production of important N-containing, heterocyclic chemicals...

Comparison between one-step self-etch adhesive and along with additional hydrophobic layer in the retention of giomer at non-carious cervical lesion

The purpose of the present study was to assess the giomer retention following application of one step self etch adhesive and one-step self-etch adhesive plus an extra hydrophobic adhesive layer in non-carious cervical lesion. Twenty four participants having bilateral cervical lesion at the maxillary premolars teeth were selected. Following cleaning of the cervical lesions, 24 left premolar teeth were restored with giomer by using the one-step self-etch system (Group A) and 24 right premolar teeth were restored with giomer by using one-step self-etching plus extra hydrophobic adhesive layer (Group B). Participants were recalled at 6 and 15 months for evaluating the clinical outcome. The results showed that at 15 months, 18 giomer restorations in Group A and 21 in Group B were intact inside the cavity and no significant difference was found between the two groups. It can be concluded that giomer restoration used with one-step self- etching plus additional adhesive layer slightly improved the retention of the material.

Stability of carbohydrate production in continuous microalgal cultivation under nitrogen limitation: effect of irradiation regime and intensity on Tetradesmus obliquus

In this work, the effect of nitrogen limitation on Tetradesmus (Scenedesmus) obliquus cultivation was evaluated in a continuous system operated at steady-state to assess the carbohydrate productivity in a single step. Under continuous irradiance (150 and 650 μmol photons m−2 s−1), with an optimized nitrogen limitation in the reactor inlet stream, a carbohydrate fraction of 45% was achieved, with a remarkable productivity of 0.80 g L−1 day−1. Under simulated day-night irradiation, a cyclic steady state was obtained, as a result of alternating light and dark conditions, with an average carbohydrate production of 0.71 and 0.30 g L−1 day−1 (summer and winter, respectively), with a biomass productivity reduced due to the photoperiod. The uptake of nutrient by the cell appeared to be regulated by the light regime, which determines the carbohydrate accumulation as well. Accordingly, it was possible to obtain a stable carbohydrate production in one-step continuous system with day-night and seasonal irradiation by properly managing the nitrogen inlet.

One-Step Printable Perovskite Films Fabricated under Ambient Conditions for Efficient and Reproducible Solar Cells.

Despite the potential of roll-to-roll processing for the fabrication of perovskite films, the realization of highly efficient and reproducible perovskite solar cells (PeSCs) through continuous coating techniques and low-temperature processing is still challenging. Here, we demonstrate that efficient and reliable CH3NH3PbI3 (MAPbI3) films fabricated by a printing process can be achieved through synergetic effects of binary processing additives, N-cyclohexyl-2-pyrrolidone (CHP) and dimethyl sulfoxide (DMSO). Notably, these perovskite films are deposited from premixed perovskite solutions for facile one-step processing under a room-temperature and ambient atmosphere. The CHP molecules result in the uniform and homogeneous perovskite films even in the one-step slot-die system, which originate from the high boiling point and low vapor pressure of CHP. Meanwhile, the DMSO molecules facilitate the growth of perovskite grains by forming intermediate states with the perovskite precursor molecules. Consequently, fully printed PeSC based on the binary additive system exhibits a high PCE of 12.56% with a high reproducibility.