Acid Methyl Research Articles

Identification of Urinary Metabolite Biomarkers of Type 2 Diabetes Nephropathy Using an Untargeted Metabolomic Approach.

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus (DM). To discover early stage biomarkers of DN, untargeted liquid chromatography-mass spectrometry-based metabolomic analysis was performed in urine samples from healthy subjects and patients with micro- or macroalbuminuria due to nondiabetic disease (macro), type 2 DM without microalbuminuria (T2DM), and type 2 DM with microalbuminuria (T2DM+micro). Levels of four metabolites were significantly different among groups, and they were quantified in a larger group of 267 urine samples. Two metabolites were also discovered and validated in targeted metabolic study of amino acids. For diagnosis of nephropathy, N1-methylguanosine had the highest area-under-the-curve (AUC) value of 0.75 when compared to those of valine (0.68), xanthosine (0.67), and 7-methyluric acid (0.69). After combining fasting blood glucose and diastolic blood pressure (DBP) with N1-methylguanosine, the AUC increased to 0.987. To distinguish between T2DM and T2DM+micro conditions, xanthosine and N1-methylguanosine have AUC value of 0.612 and 0.624, respectively. After adjustment of HbA1c and DBP, AUC values of xanthosine and N1-methylguanosine increased to 0.716 and 0.723, respectively, and could be used to predict the development of nephropathy in T2DM patients.

Electrode Design to Overcome Substrate Transparency Limitations for Highly Efficient 1 cm2 Mesoscopic Perovskite Solar Cells

Summary Fluorine-doped tin oxide glass substrate is typically used for state-of-the-art perovskite solar cells (PSCs). However, indium-doped tin oxide (ITO) is better due to higher transparency for a given conductivity, although it has lower tolerance to high-temperature processes required for the compact and mesoporous TiO2 layers. Here we overcome this challenge by developing and utilizing a new electrode design. We successfully demonstrate high-efficiency mesoscopic PSCs on annealed ITO substrates showing improved photocurrent without sacrificing fill factor. After further optimizations of cell geometry and substrate conductivity guided by simulation, a certified 19.63% efficiency is achieved on 1 cm2 for ITO-based mesoscopic PSC, which is the highest among PSCs prepared by gas quenching. This work is useful for providing design principles and methods for optimizing cell geometry, metal electrode design, and substrate conductivity requirements for large-area PSCs.

Xanthine urolithiasis: Inhibitors of xanthine crystallization.

ObjectiveTo identify in vitro inhibitors of xanthine crystallization that have potential for inhibiting the formation of xanthine crystals in urine and preventing the development of the renal calculi in patients with xanthinuria.MethodsThe formation of xanthine crystals in synthetic urine and the effects of 10 potential crystallization inhibitors were assessed using a kinetic turbidimetric system with a photometer. The maximum concentration tested for each compound was: 20 mg/L for 3-methylxanthine (3-MX); 40 mg/L for 7-methylxanthine (7-MX), 1-methylxanthine (1-MX), theobromine (TB), theophylline, paraxanthine, and caffeine; 45 mg/L for 1-methyluric acid; 80 mg/L for 1,3-dimethyluric acid; and 200 mg/L for hypoxanthine. Scanning electron microscopy was used to examine the morphology of the crystals formed when inhibitory effects were observed.ResultsOnly 7-MX, 3-MX, and 1-MX significantly inhibited xanthine crystallization at the tested concentrations. Mixtures of inhibitors had an additive effect rather than a synergistic effect on crystallization.ConclusionTwo of the inhibitors identified here—7-MX and 3-MX—are major metabolites of TB. In particular, after TB consumption, 20% is excreted in the urine as TB, 21.5% as 3-MX, and 36% as 7-MX. Thus, consumption of theobromine could protect patients with xanthinuria from the development of renal xanthine calculi. Clinical trials are necessary to demonstrate these effects in vivo.

Bifacial Modified Charge Transport Materials for Highly Efficient and Stable Inverted Perovskite Solar Cells.

Significant efforts have been devoted to enhancing both the performance and long-term stability of lead halide perovskite solar cells (PSCs) to promote their practical application. In this context, a self-assembled monolayer composed of a dye molecule is demonstrated for the first time to be efficient in passivating the surface of the hole transport layer, NiO x, in the p-i-n PSCs through multiple functions, including the minimization of energy-level offset, reducing surface trap states, and enhancing wetting between NiO x and perovskite layers coupled with increasing perovskite crystallinity. Consequently, the dye monolayer has sufficiently improved the hole extraction efficiency and suppressed the charge recombination, validated by steady and transient photoluminescence measurements and the electrochemical impedance analysis. Concurrently, a mixed layer of BaSnO3 nanoparticles and [6,6]-phenyl-C61-butyric acid methyl (PCBM) (barium stannate (BSO)/PCBM) was exploited as an efficient electron transport layer, resulting in superior electron transport properties and correspondingly excellent device stability. By incorporating these bifacial modifications, the device performance of the inverted PSC was propelled to 16.2%, compared with 14.0% for that without any interfacial and compositional engineering. Benefiting from the excellent crystallinity of the perovskite through dye passivation and the blocking of moisture, oxygen, and ion migration by using the hybrid BSO/PCBM layer, over 90% of the initial power conversion efficiency has been preserved for the device after exposure to ambient air for 650 h.

Morphological and molecular effects of phenolic extract from coconut kernel on human prostate cancer cell growth in vitro

Coconut is an indispensable ingredient in the diet and traditional medicine of individuals belonging to the Indian subcontinent. Coconut is of high nutritional value owing to the presence of all essential dietary components, viz, saturated fatty acids, arginine rich proteins, fibre and minor components like vitamin E, phytosterols, polyphenols and flavonoids. The polyphenolic content present in coconut kernel is of particular interest due to their numerous reported beneficial effects such as reduction of oxidative stress, combating cancer and in modulating anti-inflammatory pathways. Therefore, in the present study the cytotoxic effect of the polyphenol rich fraction from coconut kernel (CKf) was evaluated in human prostate cancer (DU-145) cells. Individual components present in CKf was determined by LC-MS analysis. It showed that CKf contained several bioactive molecules which have potential anticancer activity viz, coumaric acid, myristin, chlorogenic acid and triterpenoid methyl esters. The cytotoxic effect of CKf at various concentrations (2.5–20 μg/ml) on DU-145 was assessed using MTT assay, AO/EB staining, mitochondrial superoxide/ROS production and changes in intracellular calcium levels, 24 hrs post treatment. Changes in the cell morphology and nucleus were observed using Scanning Electron Microscopy and Confocal microscopy. ROS and mitochondrial superoxide levels was evaluated using DCHF-DA and MitoSOX staining respectively. The impact of ROS on changes in cellular calcium levels was also studied using Fura-2-AM. LDH leakage from C K f treated and control cells were observed colorimetrically. Further, PCR analysis was done to detect changes in mitochondria associated apoptotic gene expression. It was also observed that C K f treatment increased the expression of pro-apoptotic genes - Bax, Bid, Bak and p53 in a dose-dependent manner. Based on the above results, it can be concluded that C K f may be used as a part of a dietary regime for controlling the progression of prostate cancer.

High-Performance Inverted Polymer Solar Cells: Study and Analysis of Different Cathode Buffer Layers

The effect of different cathode buffer layers on the performance of inverted organic solar cells (OSCs) fabric-ated with {poly[[2,6’-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,3-b]dithiophene][3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno[3,4-b]thiophenediyl]] (PTB7-Th):[6,6]-phenyl-C71-butyric acid methyl} (PC70BM) as active blend layer is studied using device simulator Silvaco/ATLAS TCAD. The parameters used in the simulations were extracted in fabricated OSCs, using the metal-insulator-metal model, obtaining very good agreement between measured and simulated current density ( $J_{{\rm{SC}}}$ ), open-circuit voltage ( $V_{{\rm{OC}}}$ ), fill factor, and power conversion efficiency (PCE). The enhanced performance observed for devices where either 10 nm of poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene) (PFN), 0.6 nm of lithium fluoride (LiF) layer, or the combination of these two materials, was very well reproduced by simulation. Results indicate that the described procedure can be used to predict the behavior of new buffer layers in OSCs. The PCEs values obtained by simulation were 10.90%, 10.45%, 10.38%, 9.03%, and 7.60% for OSCs with cathode buffer layer consisting of the stack PFN/LiF, PFN, LiF/PFN, LiF and without cathode buffer layer, respectively, which agree well with measured values.

Developing a UV-Curable, Environmentally Benign and Degradable Elastomer for Soft Robotics

ABSTRACTThis paper introduces preliminary work on a UV-curable, environmentally benign and degradable elastomer, poly(glycerol sebacate itaconate), or PGSI, for use in soft robotics. A one-pot, solvent-free synthesis route using safe and inexpensive chemical reagents was developed to enable easy adoption into soft robotics labs. Material characterization of non-aged PGSI samples gave: ultimate tensile strength (UTS) ranging from 134 to 193 kPa with moduli ranging from 57 to 131 kPa and elongations at break ranging from 105 to 137 % (12 samples from 6 batches tested), and resilience values ranging from 73 to 82 % (3 samples from 3 batches tested). FTIR analysis showed a possible decrease in carbon-carbon double bonds after UV curing, evidencing a decrease in itaconic acid methylene groups from photoinitiated free radical cross-linking. NMR on the pre-polymer suggested incorporation of itaconic acid into the main polymer chain and evidence of heterogeneity of the polymer backbone resulting from glycerol bonding. An example molded soft pocket pneumatic actuator is created and briefly characterized. With further development, PGSI can be a degradable material to incorporate into temporary soft robots.

Orientation Regulation of Phenylethylammonium Cation Based 2D Perovskite Solar Cell with Efficiency Higher Than 11%

AbstractIncreasing the power conversion efficiency (PCE) of the two‐dimensional (2D) perovskite‐based solar cells (PVSCs) is really a challenge. Vertical orientation of the 2D perovskite film is an efficient strategy to elevate the PCE. In this work, vertically orientated highly crystalline 2D (PEA)2(MA)n–1PbnI3n+1 (PEA= phenylethylammonium, MA = methylammonium, n = 3, 4, 5) films are fabricated with the assistance of an ammonium thiocyanate (NH4SCN) additive by a one‐step spin‐coating method. Planar‐structured PVSCs with the device structure of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)/(PEA)2(MA)n–1PbnI3n+1/[6,6]‐phenyl‐C61‐butyric acid methyl ester/bahocuproine/Ag are fabricated. The PCE of the PVSCs is boosted from the original 0.56% (without NH4SCN) to 11.01% with the optimized NH4SCN addition at n = 5, which is among the highest PCE values for the low‐n (n < 10) 2D perovskite‐based PVSCs. The improved performance is attributed to the vertically orientated highly crystalline 2D perovskite thin films as well as the balanced electron/hole transportation. The humidity stability of this oriented 2D perovskite thin film is also confirmed by the almost unchanged X‐ray diffraction patterns after 28 d exposed to the moisture in a humidity‐controlled cabinet (Hr = 55 ± 5%). The unsealed device retains 78.5% of its original PCE after 160 h storage in air atmosphere with humidity of 55 ± 5%. The results provide an effective approach toward a highly efficient and stable PVSC for future commercialization.

New Strategy for Two‐Step Sequential Deposition: Incorporation of Hydrophilic Fullerene in Second Precursor for High‐Performance p‐i‐n Planar Perovskite Solar Cells

AbstractIn p‐i‐n planar perovskite solar cells (pero‐SCs) based on methylammonium lead iodide (MAPbI3) perovskite, high‐quality MAPbI3 film, perfect interfacial band alignment and efficient charge extracting ability are critical for high photovoltaic performance. In this work, a hydrophilic fullerene derivative [6,6]‐phenyl‐C61‐butyric acid‐(3,4,5‐tris(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)phenyl)methanol ester (PCBB‐OEG) is introduced as additive in the methylammonium iodide precursor solution in the preparation of MAPbI3 perovskite film by two‐step sequential deposition method, and obtained a top‐down gradient distribution with an ultrathin top layer of PCBB‐OEG. Meanwhile, a high‐quality perovskite film with high crystallinity, less trap‐states, and dense‐grained uniform morphology can well grow on both hydrophilic (poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonic acid)) and hydrophobic (polytriarylamine, PTAA) hole transport layers. When the PCBB‐OEG‐containing perovskite film (pero‐0.1) is prepared in a p‐i‐n planar pero‐SC with the configuration of ITO/PTAA/pero‐0.1/[6,6]‐phenyl‐C61‐butyric acid methyl ester/Al, the device delivers a promising power conversion efficiency (PCE) of 20.2% without hysteresis, which is one of the few PCE over 20% for the p‐i‐n planar pero‐SCs. Importantly, the pero‐0.1‐based device shows an excellent stability that can retain 98.4% of its initial PCE after being exposed for 300 h under ambient atmosphere with a high humidity, and the flexible pero‐SCs based on pero‐0.1 also demonstrate a promising PCE of 18.1%.

Photodegradation of azo dyes: photocatalyst and magnetic investigation of CoFe2O4–TiO2–Ag nanocomposites

In the first step, CoFe2O4 nanostructures were synthesized via a facile precipitation method without using any surfactant. The CoFe2O4-TiO2 nanocomposites were then prepared using the sol–gel method. The silver nanoparticles were produced by reducing silver nitrate (AgNO3) with sodium borohydride (NaBH4). By adding a reducing agent, CoFe2O4–TiO2–Ag was produced by a simple precipitation method. The prepared products were characterized by X-ray diffraction and scanning electron microscopy. The vibrating sample magnetometer shows the ferromagnetic property of ferrite nanostructures. The photocatalytic behavior of the CoFe2O4–TiO2–Ag nanocomposites was evaluated using the degradation of three dyes (acid violet, methyl orange, and acid blue) method ultraviolet light irradiation. The results showed a nanocomposite with an applicable magnetic and photocatalytic performance.

Insights into the Failure Mechanisms of Organic Photodetectors

AbstractThis work investigates in detail the reliability of poly(2,7‐carbazole‐alt‐4, 7‐dithienyl‐2,1,3‐benzothiadiazole):phenyl‐C61‐butyric acid methyl ester‐based organic photodiodes (OPDs) under visible light and air exposure. The current–voltage (I–V) characteristics of the state‐of‐the‐art OPDs are measured both at room and low temperature, before, during, and after ageing. While electrodes are only slightly impacted by ageing, the active layer is significantly damaged regardless the absence of UV light, leading to a major decrease in the responsivity. The combination of the thermally stimulated current and the I–V characteristics versus temperature (I–V–T) techniques along with the extensive use of the drift‐diffusion simulations all reveals that the observed degradation is the consequence of the generation of shallow traps (0.2 eV, NT = 1016 cm−3) that significantly reduce the charge carrier mobility. In contrast, deep traps (0.7 eV, NT = 7 × 1015 cm−3) are found to be present on freshly prepared samples and their concentration remains unchanged after ageing.

Methylation of Aliphatic and Aromatic Carboxylic Acids with Dimethyl Carbonate under the Influence of Manganese and Iron Carbonyls

The synthesis of methyl esters has been carried out via the reaction of aliphatic and aromatic carboxylic acids with dimethyl carbonate in the presence of manganese and iron carbonyls. The optimal ratio of catalyst and reagents and other conditions for the synthesis of methyl esters of carboxylic acids with high yield have been found.

An Improved Preparation of (R)-3-Aminobutanol, a Key Intermediate for the Synthesis of Dolutegravir Sodium

Background: Dolutegravir sodium is a HIV-1 integrase strand transfer inhibitor (INSTI) and in combination with other anti-retroviral agents, is recommended for the treatment of HIV-1 infection. Moreover, it is a second generation HIV integrase inhibitor designed to deliver potent antiviral activity. Originally, collaboration between Shionogi and Glaxo Smith Kline (GSK) led to dolutegravir sodium which is marketed under the trade name Tivicay®. Its synthesis involves the reaction of (R)-3-aminobutanol (1) with 3-benzyloxy-4-oxo-1-(2-oxoethyl)-1,4-dihydropyridine- 2,5-dicarboxylic acid 2-methyl ester. Later, the (R)-3-aminobutanol became a key intermediate for the synthesis of Dolutegravir sodium. Methods: In our method the (R)-3-aminobutanol is synthesized in a three/four-step synthetic protocol using 4-Hydroxy 2-butanone as starting material, initial formation of oxime with hydroxyl amine, followed by replacement of developed lithium aluminum hydride (LAH) for reduction of oxime using Raney ‘Ni’, which provided the enantiomeric mixture of 3-aminobutanol in about 85-90 % yield, which is more significant compared to earlier approach (yield: 70 %). Further the mixture was resolved with D-(-)-tartaic acid to obtain the R-isomer as an ester. The ester is then hydrolyzed with potassium carbonate in methanol to give pure (R)-3-amino butanol in 90 % yield and chiral purity was found to be 99.89 % by HPLC. Results: The present method is highly economical and eliminates the use of expensive catalysts. Moreover, the reaction conditions adopted in this process are mild and suitable for industrial applications and is further supported by our study with a large scale (up to 30 Kg) and the yields obtained are quite good. It is our claim that the present methodology is extremely useful for preparation of (R)-3-aminobutanol on commercial scale. Conclusion: We have developed a simple and efficient method for the synthesis of (R)-3- aminobutanol in industrial scale from 4-hydroxy-2-butanone. The process also involves the use of Raney Ni as an eco friendly reagent for the conversion of oxime to amine which is superior to reported LAH approach. Further, the process also uses an inexpensive D-(-)-tartaric acid as a chiral reagent. The developed method involves very cheap reagents, experimental procedures are highly convenient and the yields are impressive. Keywords: Dolutegravir sodium, (R)-3-aminobutanol, D-tartaric acid, resolution, Raney ‘Ni’, 4-hydroxy-2-butanone, chiral reagent.

Quantification of xanthine- and uric acid-related compounds in urine using a “dilute-and-shoot” technique coupling ultra-high-performance liquid chromatography and high-resolution Orbitrap mass spectrometry

Quantitative analysis of relevant metabolites in biofluids such as urine is often a tedious procedure, since it usually requires extraction, purification or preconcentration. For instance, in the analysis of methylxanthines in urine, a solid-phase extraction is often required. In the current work, a rapid and highly sensitive "dilute-and-shoot" method combining ultra-high-performance liquid chromatography and high-resolution mass spectrometry (UHPLC/HRMS) was validated for urinary determination of twelve analytes: uric acid, hypoxanthine, xanthine, 1-methyluric acid, 1,3-dimethyluric acid, 1-methylxanthine, 3-methylxanthine, 7-methylxanthine, theophylline, theobromine, paraxanthine and caffeine. These analytes are the major physiological metabolites of caffeine, theobromine or theophylline, or final products of purine catabolism. The separation was carried out on a core-shell Kinetek EVO C18 column coupled to a Q Exactive Orbitrap high-resolution mass spectrometer equipped with a heated electrospray ionization (HESI) probe, that operated both in positive and negative ionization modes. The twelve analytes eluted from between 1.5 and 10.5min. The lower limit of quantification (LLOQ) values ranged from 0.25 to 2.5ng/mL, and the calibration curves were linear from the LLOQ to 100ng/mL. The only pretreatment needed was to dilute each urine sample (typically to 1/500) with 0.1% formic acid solution, and then filter the diluted sample before injecting it into the UHPLC system. With this high dilution, there were no significant matrix effects, and the intra- and inter-day precision and accuracy values were acceptable (coefficients of variance and relative errors below 15%, except for the LLOQ, for which they were below 20%). Furthermore, the analysis of spiked urine samples with 25ng/mL of the target analytes showed excellent recoveries and precision levels for the twelve analytes. To our knowledge, there is no other published method that allows for the simultaneous determination of the concentrations of these twelve compounds, nor has a previously reported method been indicated to show such low LLOQ values as we have for the majority of the analytes. We expect our protocol to be useful for nutritional assessments, interventional studies, kidney stone research, and purine metabolism studies.

Enzymatic Tandem Approach to Knoevenagel Condensation of Acetaldehyde with Acidic Methylene Compounds in Organic Media

A tandem enzyme‐catalyzed Knoevenagel reaction with acetaldehyde is presented. A new protocol for the synthesis of the desired products through a tandem process based on the enzymatic hydrolysis and Knoevenagel reaction starting from acetaldehyde precursors is disclosed. The influence of the reaction conditions including organic solvent, enzyme type, and temperature on the reaction course was tested. Further, this protocol was extended by subsequent tandem chemoenzymatic transformations leading to epoxides.

Quantification of fatty acids in erythrocytes and plasma by fast gas chromatography.

As a result of the heterogeneous nature of lipid classes in complex biological matrices such as plasma and erythrocytes, it is imperative to have a robust and validated methodology for fatty acid quantification. The effective method presented here combines available methodology of fast gas chromatography and an improvement of the sample preparation methodology before injection into the gas chromatograph. This methodology ensures complete transesterification and quantification of total and individual fatty acids (and not only in relative amounts) by addition of internal standards. We considered sample preparation key, and we established the use of lysis buffer and ethanol for erythrocytes and plasma sample preparation, respectively. Fatty acid profile was determined by acid methylation and fast gas chromatography equipped with a flame ionization detector. The triacylglycerol 13:0, phosphatidylcholine 23:0, and methyl esters 21:0 were used as internal standards. Within the linearity of the calibration, the ratio of the peak area of each fatty acid over the peak area of the internal standard was constant (coefficient of variation≤2.5). Satisfactory repeatability <15% and intermediate reproducibility <15% were observed. Finally, this validated method was applied to a pre-clinical trial that investigated the impact of dietary fats on accretion of specific fatty acids in plasma and erythrocytes.

Air Dependence of Electrical Performance Parameters in Polymeric Organic Solar Cell

The manufacture under air environment of organic solar cells (OSC) has been the main attention of many research groups in the last years due to analyze and study the stability and degradation process of the photovoltaic devices. Recent advances in polymer-based organic solar cells have been possible due to different approaches such as design of new devices and synthesis of new materials such as small molecule and polymers with low band-gaps, control of the nanoscale morphology with additives, variation of the ratio of the donor/acceptor in the bulk heterojunction, application of thermal or solvent annealing process, among others [1-3]. For large area fabrication, most reports agree that the roll-to-roll process seems to be the most promising in the last years. However, the fabrication process is difficult to realize completely under N2 environment and it is well known that OSC under air environment degrade due to low-stability of some organic semiconductors when exposed under H2O and O2 environment. Tandem structures in combination with organic materials have been manufactured employing roll-to-roll process [4-7] which some of them are manufactured under air environment. The effects of exposing the samples to air environment during the fabrication process are not well studied, being necessary a more detailed analysis to indicate which the main effects that degraded the device. Results regarding the performance parameters of polymer OSCs under these conditions are not well known yet. In this scenario, we present the manufacture of OSCs partially under air environment and under N2 environment. The polymer used of low band-gap was poly[[4,8-bis[(2-ethylhexyl)-oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) in combination with [6,6]-phenyl-C71-butyric acid methyl (PC70BM) to get the blend layer. The device inverted structure was manufactured with the stack: indium tin oxide (ITO) / poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9–dioctylfluorene)] (PFN) / PTB7:PC70BM / vanadium oxide (V2O5) / silver (Ag) as is shown in Figure 1a. The PFN and the PTB7:PC70BM layers were prepared and deposited under N2 environment. Afterwards, two groups of solar cells were formed. The first group of samples was taken out of the glove box and exposed under air environment (60% relative humidity at 24 oC) for 10 min before depositing by thermal evaporation the V2O5 and Ag layers. While that the second group of samples were finished the fabrication completely under N2 environment. The last group was made to compare with the first group of samples. Electrical characterizations like current density–voltage were measured for both groups of inverted OSC samples under light conditions, which are shown in figure 1b. The basic parameters were extracted from J-V curves such as open circuit voltage, short-circuit current density, fill factor and power conversion efficiency. Results from the first group of cells was observed that the JSC was increased and Rs reduced due to the increment on conductivity of the active blend layer when the samples were exposed for 10 min under air environment before the metal contact deposition. Other electrical test were made such as incident photon-to-current efficiency and absorbance coefficient were obtained from the photovoltaic devices to understand the differences between the two groups of cells, as well as factors that limit the power conversion efficiency. The knowledge of this behavior is important for the fabrication, design and optimization of the OSC and to reduce the effects of manufacturing under air conditions during industrial process development in the transition from the laboratory to the large scale fabrication conditions.

Single-Crystal-like Perovskite for High-Performance Solar Cells Using the Effective Merged Annealing Method.

We report a simple, low cost, and quite effective method for achieving single-crystal-like CH3NH3PbI3 perovskite leading to a significant enhancement in the performance and stability of inverted planar perovskite solar cells (IPSCs). By employing a merged annealing method during the fabrication of an IPSC for preparing the perovskite CH3NH3PbI3 film, we remarkably increase the crystallinity of the CH3NH3PbI3 film and enhance the device performance and stability. An IPSC with the indium tin oxide/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/CH3NH3PbI3 (active layer)/[6,6]-phenyl-C61-butyric acid methyl ester/Al structure was fabricated using the merged annealing method and exhibited significantly enhanced performance with a high power conversion efficiency of 18.27% and a fill factor of 81.34%. Moreover, since two separate annealing processes are merged in the proposed annealing method, the fabrication step becomes much simpler and easier, leading to a reduction in fabrication costs.

Effective hot-air annealing for improving the performance of perovskite solar cells

We report a simple and effective method for improving the performance of CH3NH3PbI3−xClx perovskite solar cells. By employing a moisture pretreatment (MPT) and a novel hot-air annealing process (HAAP) for preparing the perovskite CH3NH3PbI3-xClx film, we could successfully enhance the crystallinity of the CH3NH3PbI3-xClx active layer and improve its photon collection properties. This led to a marked improvement in device performance. Solar cells with the structure indium tin oxide/poly(3,4-ethylenedioxythiophene) -poly(styrenesulfonate)/CH3NH3PbI3-xClx active layer/[6,6]-phenyl-C61-butyric acid methyl ester/Ca/Al and fabricated using the MPT process and the HAAP method showed significantly improved performance, including higher power conversion efficiency (PCE) and fill factor values than those of the device fabricated conventionally. The PCE increased from 9.05 to 11.87% when the MPT process was used and from 9.05 to 15.55% when both MPT and HAAP were used. Moreover, the HAAP device did not exhibit photocurrent hysteresis, which is always observed in the case of the conventionally fabricated solar cells owing to the charge traps resulting from the low quality of the perovskite film.

Chemical composition, antioxidant and antibacterial activities of Tamarix balansae J. Gay aerial parts

A previously undescribed phenolic sulphate ester, potassium 34-dihydroxy-3-methoxybenzoic acid methyl ester-5-sulphate (1), along with nine known flavonoids, kaempferol-3-O-potassium sulphate-4′,7-dimethyl ether (2), kaempferol-4′,7-dimethyl ether (3), rhamnocitrin-3-O-potassium sulphate (4), rhamnocitrin (5), kaempferol (6), quercetin (7), afzelin (8), quercetin-3-O-α-l-rhamnopyranoside (9) and luteolin-3′-O-potassium sulphate (10) were isolated from the aerial parts of Tamarix balansae. Structures elucidation was performed by comprehensive 1D and 2D NMR analyses, mass spectrometry and by comparison with literature data. The antibacterial assay against Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa bacteria showed a good activity for 2, 3, 7 and 9, with MICs ranging from 62.5 to 250 μg/mL. The abilities of these compounds to scavenge the DPPH were evaluated. Compounds 1, 7, 9 and 10 exhibited a good antiradical activity potential with IC50 values ranging from 3.0 to 115.5 μg/mL, compared with ascorbic acid (IC50 7.4 μg/mL) which was used as positive control.