Clear Solution Research Articles

Converting Tretinoin into Ionic Liquids for Improving Aqueous Solubility and Permeability across Skin.

The aim of this study is to convert tretinoin (Tr), an active pharmaceutical ingredient (API), into ionic liquid for improving aqueous solubility and permeability of Tr in transdermal drug delivery applications. Three ionic liquids of Tr (TrILs) were synthesized through neutralization reactions, which were characterized to confirm the compositions and ionic interactions. The in vitro drug release studies and skin penetration tests were carried out to assess the performance of formulations containing TrILs. The TrIL formed by choline and Tr at the molar ratio of 2:1 (2[Ch][Tr]), was found to have prominent solubility, stability as well as permeability. In contrast with the insoluble Tr, 2[Ch][Tr] presented as clear and transparent aqueous solution even after diluted to 14%. The aqueous solution of 2[Ch][Tr] demonstrated better permeation effect, of which the solution with 20% of 2[Ch][Tr] showed the optimal delivery efficiency in both epidermis (2.09 ± 0.18‰) and dermis (3.31 ± 0.48‰), realizing the improvement on the permeability of API. Meanwhile, TrILs can be easily fabricated as o/w emulsions as transdermal formulation. The emulsions are also able to improve the skin permeability of Tr, though the enhanced effect is inferior to TrILs solutions. Ionic liquid technology can be used to improve solubility and permeability of Tr, providing a high potential strategy for the development of topical formulations and the desired transdermal application of drugs.

Quantitative analysis of solid and liquid contents in reactive crystallization by in-situ Raman with support vector regression

Quantitative analysis of crystallization processes remains challenging due to the complicated relationships among the multiple phases and their spectra. In this work, in situ Raman spectroscopy was chosen to quantitatively analyze the solution concentration and suspension density simultaneously in a crystallization process. A model based on support vector regression (SVR) was developed to separate the information of solution and solid from the Raman spectra. The simultaneous correlations of the spectra with solution concentration and suspension density were achieved and the results were evaluated. It demonstrated that the SVR-based method proposed in this work gave satisfactory fitting and prediction performance. Furthermore, the model was validated in the reactive crystallization of the ternary NaHCO3-Na2CO3-H2O system. It suggested that baseline removal is not necessary when using this model. The effect of bubbles should be included for the clear solution but could be neglected in solid suspensions. The results of this work provide a simple and rapid option for the quantitative analysis of crystallization processes and similar suspension systems.

New insights into the DPSIR model: Revealing the dynamic feedback mechanism and efficiency of ecological civilization construction in China

Managing ecosystems is considered a “wicked problem” without clear solutions due to the limited understanding of complex ecosystems and social dynamics. In this study, a method based on the Driving forces–Pressures–State–Impacts–Responses (DPSIR) framework was developed to reveal the Ecological Civilization Construction (ECC) together with structural equation modeling (SEM), panel data model (PDM), coupling and coordination degree (CCD) model, and data envelopment analysis (DEA). The SEM reveals that component Responses as exogenous variables can better explain the DPSIR framework nexuses than Driving forces, indicating that environmental protection measures taken by Chinese government played a dominant role in ECC. ECC indexes (ECCI) of 30 Chinese provinces were 18–87% higher in 2019 than 2012, and the PDM demonstrates that temperature, precipitation, and GDP can explain about 87.2% of ECCI variation among 30 provinces. About 12–40% increase in CCD within the DPSIR framework were detected in 30 Chinese provinces in 2019 compared to 2012. The DEA suggests that China's ECC's average comprehensive and technical efficiencies were only 0.62 and 0.77 in 2019, respectively. Meanwhile, these results show that ECC remains to be strengthened and coordinated. Implications on ECC were proposed for some provinces. Overall, this study proposes a Response-driven pathway named RDPSI can explain the achievements and limitation factors in China's ECC. Also, our results emphasize the importance of integrating science and technology, policy formulation, and precise implementation to achieve sustainable development.

Research on College English Classroom Teaching Model Based on Adaptive Genetic Algorithm

While college English teaching is steadily changing from static knowledge transfer to dynamic language ability development, classroom activities centered on language application are becoming more and more important in cultivating students' language application ability. In recent years, education has been paid more and more attention, the scale of university education has gradually expanded, the professional categories have become more and more complete, the curriculum has become larger and larger, and the number of students has grown by leaps and bounds. The teaching resources (teachers, classrooms, teaching equipment, etc.) and the workload of English teachers are increasing. In order to effectively improve the efficiency of college English teaching, the paper proposes to apply genetic algorithms to the actual English course scheduling problem in colleges, taking into account all the various hardware and software constraints and the expected course scheduling goals, so as to provide a clear and concise solution to the course scheduling problem plan (parallel search for optimal scheduling) and the design and coding structure of each genetic operator. Furthermore, this study creates a genetic algorithm-based English social platform and examines the design aspects of dynamic teaching models and classroom activities of college English students in the context of this paper.

Robustness analysis of Adaptive Model Predictive Control for uncertain non-linear dynamic systems using s-gap metric concepts

Robustness analysis of adaptive control systems, when operating in a certain domain, has been a gulf during the past decades. This problem is more complicated in the case of non-linear dynamic systems including un-modelled dynamics as unstructured uncertainty. To find a clear solution for this famous and interesting problem, limitations and effects of controller operation on performance of on-line model identification procedure (and vice versa) must be determined. In this paper, as the main novelty, we show that it needs some developments and new concepts in robust control theory as the s-gap metric, generalized stability margin (GSM) and modifications on the gain bound calculation. These achievements help us to present an on-line identification method with its convergence proof in sense of the s-gap metric and a relation between GSM and identifier convergence area. Therefore, consideration of GSM in Adaptive Model Predictive Control (AMPC) cost function concludes a systematic solution relating controller robustness and adaptivity, clearly. To this aim, a linear matrix inequality (LMI) representation for GSM constraint is suggested. Also, the stability of AMPC on a certain operating domain is guaranteed in sense of the s-gap metric and GSM. All of these help to determine the attraction area of closed loop system and we show that there exists a trade-off between each two cases of the attraction area size, convergence area size and robustness of closed loop control system. Finally, simulations and experimental results imply on correctness of the proposed method.

Room-Temperature Persistent Luminescence in Metal Halide Perovskite Nanocrystals for Solar-Driven CO 2 Bioreduction

Room-Temperature Persistent Luminescence in Metal Halide Perovskite Nanocrystals for Solar-Driven CO ₂ Bioreduction

An Enhanced LC-MS-MS Technique for Distinguishing Δ8- and Δ9-Tetrahydrocannabinol Isomers in Blood and Urine Specimens.

Among the abundance of cannabinoids identified in cannabis, the active parent drug, Δ9-tetrahydrocannabinol (Δ9-THC), and its oxidized metabolite, 11-nor-9-carboxy-Δ9-THC (Δ9-THCCOOH), are attractive analytical targets to detect cannabis use. More recently, confirmation of these analytes may be hindered by a related interfering compound. Forensic toxicology laboratories attribute this phenomenon to an increase in cases containing Δ8-tetrahydrocannabinol (Δ8-THC) and 11-nor-9-carboxy-Δ8-THC (Δ8-THCCOOH). It is technically challenging to chromatographically resolve and accurately quantify Δ8- and Δ9-THC and THCCOOH in toxicology specimens due to their structural resemblance. This study describes a validated method to resolve and quantify active Δ8-THC and Δ9-THC in blood while qualitatively confirming the inactive metabolites Δ8-THCCOOH and Δ9-THCCOOH in blood and urine. Analytes are extracted and concentrated by solid-phase extraction and analyzed by liquid chromatography--electrospray ionization tandem mass spectrometry, which is amenable to modern toxicology laboratory routine workflows. This procedure offers a clear solution to untangling mixtures of these isomers, particularly in cases where Δ8-THC and its metabolite are the sole or dominant form.

A Hypothesis on How the Azolla Symbiosis Mitigates Nitrous Oxide Based on In Silico Analyses

Nitrous oxide is a long-lived greenhouse gas that exists for 114 years in the atmosphere and is 298-fold more potent than carbon dioxide in its global warming potential. Two recent studies showcased the utility of Azolla plants for a lesser footprint in nitrous oxide production from urea and other supplements to the irrigated ecosystem, which mandates exploration since there is still no clear solution to nitrous oxide in paddy fields or in other ecosystems. Here, we propose a solution based on the evolution of a single cytochrome oxidase subunit II protein (WP_013192178.1) from the cyanobiont Trichormus azollae that we hypothesize to be able to quench nitrous oxide. First, we draw attention to a domain in the candidate protein that is emerging as a sensory periplasmic Y_Y_Y domain that is inferred to bind nitrous oxide. Secondly, we draw the phylogeny of the candidate protein showcasing the poor bootstrap support of its position in the wider clade showcasing its deviation from the core function. Thirdly, we show that the NtcA protein, the apical N-effecting transcription factor, can putatively bind to a promoter sequence of the gene coding for the candidate protein (WP_013192178.1), suggesting a function associated with heterocysts and N-metabolism. Our fourth point involves a string of histidines at the C-terminal extremity of the WP_013192178.1 protein that is missing on all other T. azollae cytochrome oxidase subunit II counterparts, suggesting that such histidines are perhaps involved in forming a Cu center. As the fifth point, we showcase a unique glycine-183 in a lengthy linker region containing multiple glycines that is absent in all proximal Nostocales cyanobacteria, which we predict to be a DNA binding residue. We propose a mechanism of action for the WP_013192178.1 protein based on our in silico analyses. In total, we hypothesize the incomplete and rapid conversion of a likely heterocystous cytochrome oxidase subunit II protein to an emerging nitrous oxide sensing/quenching subunit based on bioinformatics analyses and past literature, which can have repercussions to climate change and consequently, future human life.

Clouding and thermodynamic behavior of the triton X-100 + metformin hydrochloride drug mixture: Investigation of the impacts of potassium salts

The cloud point (CP) of aqueous triton X-100 (TX-100) and metformin hydrochloride (MNH) mixture was investigated in the attendance of various inorganic salts (KCl, KHSO4, K2SO4, and K3PO4) media. TX-100 concentration for CP measurement was chosen well above the critical micelle concentration value of TX-100. The values of CP decrease as the electrolyte’s concentration raises, turning the clear solution cloudy. The reason of the reducing CP is the enhanced aggregation. Thermodynamic variables of the clouding process (standard free energy (ΔG0c), standard enthalpy (ΔH0c), and standard entropy (ΔSco)) were determined at CP. The Gibbs free energy (ΔG0c) values were positive but dropped as the additive (inorganic electrolytes) concentrations increased. This result demonstrated that the TX-100 + MNH mixture's phase partition was thermodynamically unfavoured, and the percentage of its non-spontaneity reduced as the electrolytes concentration enhanced. The values of enthalpy (ΔH0c) and entropy (ΔSco) for the phase separation were achieved negative at lower electrolyte concentrations and positive at higher contents. The ΔH0c and ΔSco values suggest that hydrophobic and electrostatic interactions are the primary forces amongst TX-100 and MNH. Here, the intrinsic enthalpy gain (ΔH0*c) and the compensation temperature (Tc) are as well computed and explained.

Irrigation Solutions and Antibiotic Powders: Should I Use Them in Primary and Revision Total Joint Arthroplasty?

BackgroundThe prevention and treatment of periprosthetic joint infection is of utmost importance to orthopedic surgeons. Irrigation solutions have become a popular additive to the prevention and treatment armamentarium. MethodsThis symposium summarizes the mechanism of action, basic science, and clinical research to date on the use of irrigation solutions. The four most commonly used irrigation solutions, povidone iodine, chlorhexidine, hydrogen peroxide, and acetic acid, are discussed. In addition, the role of antibiotic powers is reviewed. ResultsEach solution has its risks and benefits that must be weighed by the surgeon. There is no clear irrigation solution that is superior. The role of additive antibiotic powder (vancomycin) remains controversial. ConclusionMore rigorous prospective clinical trials are needed to determine the optimal irrigation solution for the prevention and treatment of periprosthetic joint infection.

Compatibility and Physical Properties of Dexamethasone-Ondansetron Intravenous Admixture.

Purpose: This work aimed at evaluating the impact of different concentrations and final volumes on the compatibility and physical properties of dexamethasone-ondansetron intravenous (IV) admixture. Methods: The IV admixture of dexamethasone-ondansetron was prepared at different concentrations using normal saline solution as solvent. The final volume of the IV admixture was prepared at 50 and 100 ml. Turbidity was measured as an indicator of physical compatibility of the IV admixture of dexamethasone-ondansetron using UV-visible spectrophotometer and the pH of the IV admixture was measured on day 0, 7,14, and, 21 as an index of chemical stability. Also, the particle size and potential molecular interactions of the admixtures were determined using particle size analyzer and Fourier Transform infrared spectrometry analysis, respectively. Additionally, the effect of preservatives on the IV admixture was also evaluated. Results: Precipitation was observed for mixtures with amounts of dexamethasone and ondansetron exceeding 8 and 16 mg, respectively, in a final volume of 50 ml. For all mixtures with final volume of 100 ml, clear solutions void of any precipitates were observed. The pH of the solution had no effect on the precipitation of the dexamethasone-ondansetron during storage up to 21 days. Analyses of the precipitate formed revealed the presence of molecular interactions between dexamethasone and ondansetron. The benzyl alcohol used as a preservative affected the compatibility of the IV admixture compatibility. Conclusion: Thus, for the preparation of clear, physically compatible normal saline solutions of dexamethasone-ondansetron IV admixture, the maximum amounts of the respective drugs should not exceed 8 and 16 mg in total volume of 50 ml or 20 and 16 mg in a final volume of 100 ml.

Design of a DFS to Manage Big Data in Distance Education Environments

Information technologies have invaded every aspect of our lives. Distance education was also affected by this phase and became an accepted model of education. The evolution of education into a digital platform has also brought unexpected problems, such as the increase in internet usage, the need for new software and devices that can connect to the Internet. Perhaps the most important of these problems is the management of the large amounts of data generated when all training activities are conducted remotely. Over the past decade, studies have provided important information about the quality of training and the benefits of distance learning. However, Big Data in distance education has been studied only to a limited extent, and to date no clear single solution has been found. In this study, a Distributed File Systems (DFS) is proposed and implemented to manage big data in distance education. The implemented ecosystem mainly contains the elements Dynamic Link Library (DLL), Windows Service Routines and distributed data nodes. DLL codes are required to connect Learning Management System (LMS) with the developed system. 67.72% of the files in the distance education system have small file size (<=16 MB) and 53.10% of the files are smaller than 1 MB. Therefore, a dedicated Big Data management platform was needed to manage and archive small file sizes. The proposed system was designed with a dynamic block structure to address this shortcoming. A serverless architecture has been chosen and implemented to make the platform more robust. Moreover, the developed platform also has compression and encryption features. According to system statistics, each written file was read 8.47 times, and for video archive files, this value was 20.95. In this way, a framework was developed in the Write Once Read Many architecture. A comprehensive performance analysis study was conducted using the operating system, NoSQL, RDBMS and Hadoop. Thus, for file sizes 1 MB and 50 MB, the developed system achieves a response time of 0.95 ms and 22.35 ms, respectively, while Hadoop, a popular DFS, has 4.01 ms and 47.88 ms, respectively.

Distal Radioulnar Achilles Allograft Interposition Arthroplasty: Does It Solve the Problem of Persistent Pain?

Pain and instability following distal ulnar resection for distal radioulnar joint (DRUJ) arthritis is a problem without a clear solution. We investigated the outcomes of DRUJ interposition arthroplasty for the management of symptomatic radioulnar convergence. A retrospective review was performed for all patients who underwent Achilles tendon allograft interposition arthroplasty following the failure of distal ulna resection between October 2009 and January 2015. Records were reviewed for demographics, comorbidities, surgical history, pre- and postoperative pain, range of motion, grip strength, and complications. Radiographs and computed tomography scans were evaluated for distal radioulnar instability, distal ulnar absorption, ulnar scalloping, radioulnar convergence, and allograft subluxation. Reconstructive failure was defined as the presence of moderate-to-severe persistent distal radioulnar pain, instability with radiographic evidence of radioulnar convergence or allograft subluxation on radiographs or computed tomography scans, or the need for revision arthroplasty procedure. Ten patients met the inclusion criteria. The mean age was 49 ± 10 years. The average follow-up after interposition arthroplasty was 76 ± 23 months. The preoperative means of grip strength, arc of pronosupination, flexion, and extension were similar after surgery. The mean arc of pronosupination improved by 26.5°, and the wrist flexion-extension arc in patients without arthrodesis improved by 22.6°. The grip strength increased by 1.7 kg. Seven of 10 patients had continued symptoms of pain and instability related to symptomatic allograft subluxation and/or radioulnar convergence. Five patients underwent revision surgery; the mean time to revision was 26 months. Mid- to long-term follow-up of patients after salvage allograft interposition arthroplasty of the DRUJ resulted in minimal functional improvement in terms of arc of motion and grip strength. Persistent radioulnar pain was common, with half of the patients requiring revision operations following allograft interposition. Given this high failure rate, alternative procedures should be considered for the management of chronic pain and instability of the DRUJ. Therapeutic V.

Performance of 113Sn/113mIn Generator Prototype based on Zirconium Oxide for Radiotracer Applications in Industry

This paper describes the results of the research of 113Sn/113m radioisotope generator at the Centre for Applied Nuclear Science and Technology - National Nuclear Energy Agency with the aim of making radioisotope generator for radiotracer applications in industry. This research discussed the need of short half-life radiotracer for several material phases such as oil, water, gas and solid. Based on desired physical properties of half life, radiation type and energy, 113mIn radioisotope was selected. Thus, the performance of 113Sn/113mIn generator prototype based on zirconium oxide was determined for this purpose. The final product specification in the form of 113mInCl3 is clear solution, pH 2 with obtained yield of 95 %, radionuclide purity of 95 % and radiochemical purity of 95 %.

REKAYASA TABLET EFFERVESCENT DARI TOMAT DAN DAUN KELOR DENGAN PERBEDAAN RASIO ASAM DAN BASA

This study aimed to produce the best formulation in the manufacture of effervescent derived from tomatoes and Moringa leaves with different acid-base ratio treatments. Tomato and Moringa leaves were converted into powdered extracts to be formulated with citric acid, sodium bicarbonate, PVP, mannitol, and aspartame. The ratios of citric acid and sodium bicarbonate as treatments were 3:5, 4:5, and 5:5. The results showed that the formulation with an acid:base ratio (5:5) had the potential to be developed and refined before being commercialized. This formulation was chosen because it has the sensory profile with a sweet, slightly sour and fresh taste profile, the lowest Moringa leaf aroma, the color of the clear solution was slightly green and slightly orange. This formulation was made from a composition of 12.5% tomato extract powder, 7.5% Moringa leaf extract powder, 34% citric acid, 34% sodium bicarbonate, 7.5% mannitol, 3% PVP, and 1.5% aspartame. Tablet was carried out in a room with a temperature of 18℃ with a RH of 45-58%.

A Strong and Rigid Coordination Adaptable Network that Can Be Reprocessed and Recycled at Mild Conditions

A Strong and Rigid Coordination Adaptable Network that Can Be Reprocessed and Recycled at Mild Conditions

Effect of various factors on rosmarinic acid content of water mint (Mentha aquatica)

Water mint (Mentha aquatica) is well-known as a popular herbal plant in Viet Nam. Rosmarinic acid (RA) is a phenolic compound found in many genus of Mentha and has numerous biological activities. Its applications are wide from the food industry to cosmetics. The purpose of this study was to evaluate the effects of different plant parts, drying, various solvent to sample ratios (1:20, 1:30, 1:40, 1:50, 1:60, and 1:70 (w/v)) and extraction temperature (30, 50, 70, and 90°C) on RA content of water mint. Ground materials of fresh and dried leaves, fresh and dried whole plants (each for 1 g) were extracted with water. The extraction was performed on magnetic stirrer. The extract was passed through filter paper retaining the clear solution for the quantitative and RA analysis. RA content was determined by using a spectrophotometer. The dried whole plants, a solvent to sample ratio of 1:50 (w/v), extraction temperature of 70°C, and extraction time of 30 minutes were the best conditions for RA content from water mint.

EMI shielding leadless package solution for automotive

As components get closer together and more devices are integrated into a package, electromagnetic interference (EMI) is one of the most common concerns to be addressed. EMI shielding is not a new topic and its technology has widely been applied to consumer/communication products. However, mainstream products for the automotive market have no clear solution yet. Although leadframe packages, such as Microleadframe® (MLF®)/QFN, are extremely popular for automotive, it is hard to apply EMI technology at the package level because the leads are exposed at the side.In this paper, EMI shielding technology that can be applied to leadframe packages has been studied with the routable MLF (rtMLF®) package. A package structure and layout that give full EMI shielding coverage including the leads is proposed. The shield effectiveness was compared by simulation tests between MLF and RtMLF packages. Also, actual samples were manufactured that confirmed the process and revealed no abnormalities in the conformal shield layer.

Hierarchical MFI Zeolite Catalysts: How to Determine Their Textural Properties?-A Comparative Study

It is important to elucidate the role of the surface areas and pore volumes of hierarchical zeolites to understand their behavior as catalysts. Micro-and mesopore surface areas and volumes of the hierarchical MFI (Mobil Five zeolites) were assessed following several methods: (i) N2 adsorption at 77 K using classical and corrected t-plot analyses methods, (ii) pre-adsorption of n-nonane was followed by the study of the N2 adsorption at 77 K, and (iii) non-local-density functional theory (NLDFT) analysis using either the N2 adsorption method at 77 K or the Ar adsorption method at 87 K. In order to assess the viability of each method, a set of hierarchical MFI-type zeolites was prepared by different approaches: alkaline treatment (desilication), synthesis in clear solution (nanocrystals), synthesis in the presence of bifunctional organic surfactant (nanosheets), and micelle-templating assisted alkaline treatment. NLDFT methods could not be used to accurately determine the micro-and mesopore surface areas, as larger surface areas compared to those obtained using the BET equation were obtained. This overestimation is even more pronounced with Ar at 87 K. Results from the classical t-plot analysis performed under conditions of N2 adsorption at 77 K for mechanical mixtures of MFI and MCM-41 revealed the underestimation of the micropore volumes and the overestimation of the mesopore surface areas. Corrections were provided for t-plot analysis. The results obtained using the corrected t-plot method were in good agreement with the results obtained using the NLDFT method in the presence of Ar at 87 K during the calculation of the micro-and mesopore volumes of hierarchical MFI-type zeolites. Micropore and mesopore surface areas calculated by the corrected t-plot method were in good agreement with those calculated using the n-nonane pre-adsorption method for the hierarchical MFI-type zeolites characterized by the presence of large zeolite domains. The NLDFT method, in the presence of Ar, can be used to assess the micro-and mesopore volumes of the hierarchical zeolites at 87 K. However, it cannot be used to determine the surface areas. The corrected t-plot method can be used to efficiently calculate both the volumes and surface areas.

Monitoring and Understanding Urban Transformation: A Mixed Method Approach

Cities must address many challenges including air quality, climate change and the health and wellbeing of communities. Public authorities and developers increasingly look to improve these through the implementation of interventions and innovations, such as low traffic neighbourhoods, deep housing retrofits and green infrastructure. Monitoring the impacts of interventions is essential to determine the success of such projects and to build evidence for broader urban transformation. In this paper we present a mixed-method cross-disciplinary approach that brings together cutting edge atmospheric and data science, measurements of activity in public spaces and novel methods to assess wellbeing-promoting behaviours. The Manchester Urban Observatory focuses on living areas that have a high density of inter-related systems, which require observation, understanding and intervention at multiple levels. This must be completed in line with urban planning goals as well as a clear and succinct data solution that allows robust scientific conclusions to be made and viewed in real time. Delivery of such a monitoring strategy is not trivial and is time, resource and expertise heavy. This paper discusses the methods employed by the Manchester Urban Observatory to monitor the effectiveness off interventions implemented within cities and effective communication strategies with local communities.