Simple Stability Research Articles

General design method for ultralong optical path length multipass matrix cells.

For what we believe to be the first time, we propose a general design method for ultralong optical path length (OPL) multipass matrix cells (MMCs) based on the multicycle mode of two-sided field mirrors. Based on the classical Pickett Bradley White cell (PBWC), the design idea of the dual-circulation mode based on two-sided field mirrors is described in detail, with the example of the MMC based on the PBWC-PBWC. Its simple design method and optical stability analysis are given. The other three MMCs based on the dual-circulation mode using the PBWC and Bernstein Herzberg White cell (BHWC) are given. Furthermore, we propose a general design method for ultralong OPL MMCs with multicycle mode by adding cyclic elements. The OPL of the MMCs designed via this method can reach the order of kilometers or even tens of kilometers. To verify the effectiveness of the design method, a CH4 detection system with an MMC based on PBWC-PBWC-PBWC was constructed. The OPL of the MMC is 1,138 m. Allan deviation analysis reveals that the minimum detection limit of methane is 367 ppt. The design method proposed in this paper provides a new idea for the design of multipass cells (MPCs), and the new MMCs have great potential application value in the field of high-precision trace gas monitoring.

Simplified Physical Stability Assessment of Chilean Mine Waste Storage Facilities Using GIS and AI: Application in the Antofagasta Region

Simplified Physical Stability Assessment of Chilean Mine Waste Storage Facilities Using GIS and AI: Application in the Antofagasta Region

Descriptor for electro-oxidation of glycerol with high-efficiency bifunctional Cu-Nx single atom catalyst and coupled with hydrogen evolution/carbon dioxide reduction.

Electrochemical glycerol oxidation reaction (GOR) presents a promising approach for converting excess glycerol (GLY) into high-value-added products. However, the complex mechanism and the challenge of achieving selectivity for diverse products make GOR difficult to address in both experimental and theoretical studies. In this work, three nitrogen-doped graphene-supported copper single-atom catalysts (CuNx@Gra SACs, x=2-4) were selected as the model system due to their simple structure, excellent conductivity and high structural stability. Density functional theory (DFT) calculations were employed to gain deeper insight into the catalytic mechanism. The DFT results revealed that both CuN2@Gra and CuN3@Gra follow the same optimal pathway, leading to the formation of formic acid as a key product. The GOR activity and selectivity of CuNx@Gra catalysts follow the trend CuN3@Gra>CuN2@Gra>CuN4@Gra. Subsequent microkinetic analysis, based co on the DFT-derived energetics, confirmed this predicted activity sequence. The GOR activity determined by the limiting potential (UL) is correlate well with changes in the adsorption free energy (ΔGGLY*), the d-band centers of axial dz2 orbitals (εdz2) and integrated crystal orbital Hamilton population (ICOHP). Notably, the simple descriptor ΔGGLY* exhibits a good linear correlation with the free energies of other adsorbates, clarifying the conversion relationships between reaction intermediates and simplifying the understanding of reaction complexity. Moreover, computational results indicate that CuN2@Gra and CuN3@Gra systems can serve as both anode catalysts (for GOR) and cathode catalysts (CO2 reduction for CuN2@Gra and H2 evolution for CuN3@Gra). This study offers insights for designing efficient electrocatalysts, enhancing GLY utilization.

New simplified stability analysis method of structuralized cemented slopes

New simplified stability analysis method of structuralized cemented slopes

Simplified Seismic Stability Analysis of Piled Inhomogeneous Soil Slopes

Simplified Seismic Stability Analysis of Piled Inhomogeneous Soil Slopes

An Efficient pH Detector for Water Contamination Based on Mach–Zehnder Interferometer Application

This paper presents a pH sensor with a Mach–Zehnder Interferometer (MZI) that operates in solutions of 4.0, 7.0, and 10.0. The sensor device consists of two tapered sections with dimensions of 1 mm/1 mm/1 mm for down-taper, waist-length, and up-taper, respectively, with a separation of 10 mm. The diameter of the waist is 40 μm. This work includes the experimental evaluation of an MZI fiber optic pH sensor at 1559 nm, where 1559 nm represents a specific wavelength chosen for its optimal sensitivity in evaluating the sensor pH detection performance. It is not the central wavelength of the optical fiber, but one of the minimal values selected to enhance the interaction between the evanescent field and the sample, ensuring the reliable detection of pH variations. These sensor dimensions and the functionalized solution of multi-walled carbon nanotubes (MWCNTs) increase the detection of pH in dyes used in the textile industry. Alizarin is a strong anionic red dye that is part of the anthraquinone dye group. The experimental results demonstrated effective detection of pH levels in water contamination involving dye. This development could resolve the problem with Alizarin. The simple fabrication, low cost, and stability of the optical response make this sensor relevant for pH measurements in water contamination.

Stability Assessment through HPTLC for Concurrent Assessment of Azelnidipine and Telmisartan in Mass and Integrated Tablet Drug Formulation

This study aims to estimate the stability assessment through HPTLC for the concurrent assessment of (±)3-(1-diphenylmethylazetidin-3-yl)5-isopropyl-2-amino-1,4-dihydro-6-methyl-4-(3-nitrophenyl)-3,5-pyridine dicarboxylate (Azelnidipine) and 2-[4-[[4-methyl-6-(1-methylbenzimidazol-2-yl)-2-propylbenzimidazol-1-yl]methyl] phenyl]benzoic acid (Telmisartan) in combined tablet formulation, a new HPTLC approach devised and validated that is simple, quick, precise, selective, and accurate stability suggesting. The adsorbent phase used is previously coated with a silica pack on TLC aluminum plates with 60F-254 using Chloroform: Ethyl acetate (5:5 v/v) of a total of 10 ml as the mobile phase. Both Azelnidipine (Rf 0.70) and Telmisartan (Rf 0.17), at 254 nm, densitometric scanning was performed in the reflectance absorptivity mode. In the linearity range of 1-6 μg/ml for Azelnidipine and 5-30 μg/ml for Telmisartan, the calibration graph demonstrated satisfactory linearity with r2 = 0.9967 and 0.9966, respectively. Azelnidipine and Telmisartan percentage assays were discovered to be 98.87 and 100.17. The percent RSD for intraday AZL and TLM experiments was 0.0184 and 0.0068. The percent RSD for AZL and TLM interday trials was discovered as 0.0126 and 0.0068. The LOD for AZL and TLM was discovered as 910 ng/mark and 4570 ng/mark. AZL and TLM were discovered to have LOQs of 2763 ng/mark and 13850 ng/mark, respectively. According to the ICH guidelines, drugs were exposed to acidic, basic, oxidative, photo, and heat-activated degradation. The medication degrades in acidic, basic, oxidative and heat environments but not in light or neutral environments (water). This procedure can be used to efficiently isolate the drug substance from its degradation products and this is used to indicate strength and stability.. KEYWORDS :Azelnidipine, Telmisartan, HPTLC, UV-visible spectroscopy, Validation, Stability studies.

(Invited) All-Solid-State Photoelectric Conversion Cells Employing the Combination of Metal Nanoparticle and p-Type Semiconductors for Plasmon-Induced Charge Separation

Metal nanoparticles, such as gold and silver nanoparticles, can localize light energy to the nanospace near the particle surface by localized surface plasmon resonance (LSPR) under light irradiation at resonant wavelengths. In addition, by controlling parameters, such as shape and size of the metallic nanoparticles, it is possible to control the light absorption properties at any wavelength in the range from visible to near-infrared. Therefore, LSPR of metal nanoparticles is attracting attention as a technology for effective use of sunlight. When metal nanoparticles combined with semiconductors are irradiated with light at resonant wavelengths, charge is transferred from the metal nanoparticles to the semiconductors. This is called plasmon-induced charge separation (PICS) (Fig. 1(a)), and is expected to be applied to photoelectric conversion, photocatalysis, and sensing using light in the visible to near-infrared region.Conventionally, the semiconductors to be combined are mainly n-type such as TiO2. In conventional systems, a positive charge is generated on the metal nanoparticle side, causing oxidative dissolution into the electrolyte, so the only practical options for metal nanoparticles were Au (or Ag with improved stability). In the case of all-solid-state systems that do not use an electrolyte, the counter electrode must be made of a material with a low work function, such as Al or In, which has an ohmic contact at the interface with the n-type semiconductor, resulting in air oxidation and low long-term device stability (Fig. 1(c)) [1].In this study, we fabricated all-solid-state cells using p-type semiconductors as the semiconductor combined with metal nanoparticles (ITO/metal nanoparticles/p-type semiconductor/Au) (Fig. 1(d)). In this system, it was found that Ag and Cu can also be used as metal species because negative charges are generated on the metal nanoparticle side (Fig. 1(b)). In addition, Au, which makes ohmic contact with p-type semiconductors, could be used as the counter electrode, which dramatically improves the long-term stability of the device in air [2].The all-solid-state photovoltaic cells composed of p-type semiconductors and metal nanoparticles realized in this study is expected to be applied as a cost-effective solar cell with a simple structure and high stability, as well as in various other applications, such as sensing and photocatalytic systems.[1] Y. Takahashi, T. Tatsuma, Appl. Phys. Lett., 99, 182110(1 – 3) (2011).[2] Y. Takahashi, Y. Yamadori, T. Murayama, S. Shingo, S. Yamada, in preparation. Figure 1

Dynamic mRNA Stability Buffer Transcriptional Activation During Neuronal Differentiation and Is Regulated by SAMD4A.

Neurons are exceptionally sensitive to oxidative stress, which is the basis for many neurodegenerative disease pathophysiologies. The posttranscriptional basis for neuronal differentiation and behavior is not well characterized. The steady-state levels of mRNA are outcomes of an interplay between RNA transcription and decay. However, the correlation between mRNA transcription, translation, and stability remains elusive. We utilized a SH-SY5Y-based neural differentiation model that is widely used to study neurodegenerative diseases. After neuronal differentiation, we observed enhanced sensitivity of mature neurons to mitochondrial stresses and ferroptosis induction. We employed a newly developed simplified mRNA stability profiling technique to explore the role of mRNA stability in SH-SY5Y neuronal differentiation model. Transcriptome-wide mRNA stability analysis revealed neural-specific RNA stability kinetics. Our analysis revealed that mRNA stability could either exert the buffering effect on gene products or change in the same direction as transcription. Importantly, we observed that changes in mRNA stability corrected over or under transcription of mRNAs to maintain mRNA translation dynamics. Furthermore, we conducted integrative analysis of our mRNA stability data set, and a published CRISPR-i screen focused on neuronal oxidative stress responses. Our analysis unveiled novel neuronal stress response genes that were not evident at the transcriptional or translational levels. SEPHS2 emerged as an important neuronal stress regulator based on this integrative analysis. Motif analysis unveiled SAMD4A as a major regulator of the dynamic changes in mRNA stability observed during differentiation. Knockdown of SAMD4A impaired neuronal differentiation and influenced the response to oxidative stress. Mechanistically, SAMD4A was found to alter the stability of several mRNAs. The novel insights into the interplay between mRNA stability and cellular behaviors provide a foundation for understanding neurodevelopmental processes and neurodegenerative disorders and highlight dynamic mRNA stability as an important layer of gene expression.

Therapeutic effect of Micro-Implant Anchorage in orthodontics.

Micro implant anchorage (MIA), as a new orthodontic treatment technique, has the characteristics of simple operation, light trauma, and high stability, and has been widely used in clinical practice. This study compared the therapeutic effects of MIA and the traditional straight wire appliance (SWA) in orthodontic practice. Clinical data of 119 patients who underwent orthodontic treatment in Yulin First Hospital from January 2022 to January 2023 were retrospectively analyzed. According to the treatment records, 61 patients received MIA orthodontic treatment (MIA group), and 58 patients received traditional straight wire appliance (SWA) orthodontic treatment (SWA group). Treatment effect, periodontal index, and levels of osteoprotegerin (OPG), interleukin-6 (IL6) and high-sensitivity C-reactive protein (hsCRP) of the two groups were compared. The total efficacy of MIA group was significantly higher than that of SWA group (P<0.05). After the treatment, bleeding index (BI), plaque index (PLI), probing depth (PD) and looseness in the MIA group were significantly lower than those in the SWA group (P<0.05). After the treatment, levels of OPG were significantly higher, while IL6 and hsCRP levels were significantly lower in the MIA compared to the SWA group (P<0.05). MIA was associated with significantly lower complication rate compared to the SWA (P<0.05). Compared with SWA, MIA is associated with better orthodontic effect. This mode of treatment can increase OPG levels, reduce inflammation, and lower the risk of complications.

Stability Indicating RP-HPLC Method For Simultaneous Estimation of Efonidipine Hydrochloride Ethanolate and Metoprolol Succinate

A simple, precise, robustness, and accurate Stability Indicating RP-HPLC method has been developed and validated for the simultaneous assay of Efonidipine hydrochloride Ethanolate and metoprolol succinate in synthetic mixture. Isocratic RP-HPLC method was developed on Zodiac CN, (250 mm × 4.6 mm, 5μ) column using mobile phase as 20 mM Ammonium acetate: ACN (40:60) at a flow rate of 1.0 ml/min and the detection was carried out at 225 nm using photodiode array detector. Forced degradation study was carried out by oxidation, hydrolysis, photolysis, and heating the drug. The method was found to be linear in the concentration range of 5µg/ml- 500 µg/ml with correlation coefficient of 0.999 for Efonidipine hydrochloride Ethanolate and 6.25–625

Conformal SnO2 and NiOx charge transport layers for pragmatic air-processed perovskite solar cells

The industrialization of perovskite (PVK) solar cells (PSCs) necessitates simple manufacturing, cheapness, nontoxicity, high efficiency, and stability. We report an air-processed lead halide PSCs with cheap, nontoxic, stable NiOx and SnO2 as the hole and electron transport layers separately, to meet all the above commercial requests. By preparing the NiOx (water-dispersible) and SnO2 (oil-dispersible) quantum dots (QDs) with good conductivity and energy band matched well with that of PVK, we fabricate inverted PSCs (ITO/NiOx/PVK/SnO2/Ag) with efficiency up to 20.1/14.6% for active areas of 0.0707/1 cm2, under 1 sun simulated illumination with enhanced UV light ratio. The UV-light resistant PSCs reported here will impel their application in the high altitude areas with strong UV light. Importantly, the monodisperse size and dominant (110) plane of SnO2 QDs achieved by controlling the solvothermal parameters, realize the conformal deposition and defect prevention of SnO2, respectively, thus improving the PSC efficiency and stability.

Home blood pressure stability score is associated with better cardiovascular prognosis: data from the nationwide prospective J-HOP study.

A home blood pressure (BP)-centered strategy is emerging as the optimal approach to achieve adequate BP control in individuals with hypertension, but a simple cardiovascular risk score based on home BP level and variability is lacking. This study used prospective data from the Japan Morning Surge-Home Blood Pressure (J-HOP) extended study to develop a simple home BP stability score for the prediction of cardiovascular risk. The J-HOP extended study included 4070 participants (mean age 64.9 years) who measured home BP three times in the morning and evening for 14 days at baseline. During the mean 6.3-year follow-up, there were 260 cardiovascular events. A home BP stability score was calculated based on the average of morning and evening systolic BP (SBP; MEave), and three home BP variability metrics: average real variability (average absolute difference between successive measurements); average peak (average of the highest three SBP values for each individual), and time in therapeutic range (proportion of time spent with MEave home SBP 100-135 mmHg). There was a curvilinear association between the home BP stability score and the risk of cardiovascular events. Compared with individuals in the optimal home SBP stability score group (9-10 points), those in the very high-risk group (0 points) had significantly higher cardiovascular event risk during follow-up (adjusted hazard ratio 3.97, 95% confidence interval 2.22-7.09; p < 0.001), independent of age, sex, medication, cardiovascular risk factors, and office BP. These data show the potential for a simple home BP-based score to predict cardiovascular event risk in people with hypertension.

Development of a flexible strain sensor for monitoring human activities based on 3D MXene microspheres and 1D CNTs

Resistive strain sensors, which possess simple preparation, stability, and reliability features, are particularly advantageous compared to other sensor types. Here, a flexible resistance sensor designed to monitor human activities is assembled using designed three-dimensional (3D) MXene microspheres (FM@MXene) and one-dimensional (1D) CNTs in a polydimethylsiloxane (PDMS) system. The sensor exhibits a sensitivity of 5.59 and a response time of ∼330 ms, with reasonable good durability (> 200 cycles).

Spectrophotometric Assessment of Pyrocatechol Drug Employing Oxidative Coupling Reaction with 4-amino antipyrine as a Model of Pharmaceutical Compounds .

A rapid, simple, sensitive, and higher stability spectrophotometric method was developed the determine that it is stable Pyrocatechol drug in pure and pharmaceutical preparations. The method is based on an oxidative coupling reaction among Pyrocatechol drug and 4-amino antipyrine (4AAP) in the presence of potassium iodate (KIO3) in an acid medium to form a color complex that stable violet dye and a maximum absorption at 505 nm. The best optimum conditions and other analytical factors have been evaluated. A calibration curve of absorbance of several concentrations that obey the law of Beer-Lambert over the range concentration of pyrocatechol drug 10 to 100 mg/L, with (LoD =1.2*10-4 mg/L), (LoQ=3.4*10-4 mg/L), The relative standard deviations RSD% of the proposed methods were less than 0.68%). In contrast, recovery average and determination parameters are 99.9%. The method was used successfully for the determination of drugs in a pharmaceutical preparation with the best accuracy and precision. At range about 99.1 to 100.2% with RSD less than 0.3%. The analytical result for the estimation of the pure drug is presented together with the use of the proposed process for the analysis of some commercial pharmaceuticals. The data compare favorably with those of official and reported ways.

An investigation of Z-scheme homojunction BiVO4 photocatalysts for efficient green removal of ammonia nitrogen

With in-depth research on photocatalytic pollution removal, homojunction semiconductors stand out for their simple structure and stability. However, their similar energy levels result in lower photocatalytic activity compared to heterojunctions, limiting their applications in photocatalysis. Therefore, in this study, homojunction BiVO4 photocatalysts with staggered energy level structures were prepared by compositing crystalline facet-modified BiVO4 with oxygen vacancy-modified BiVO4 and used for the removal of ammonia nitrogen from water. The homojunction BiVO4 photocatalysts were successfully prepared, and the good photocatalytic performance of OBVV-2 was confirmed by several characterizations and tests, with the ammonia nitrogen removal rate of 84.3 % under visible light, of which 93.6 % was converted into harmless N2. The Z-scheme transfer mechanism was illustrated by radical capture experiments, and the repeated cycling experiments demonstrated that the homojunction photocatalysts have excellent stability. In conclusion, this study confirmed that the Z-scheme homojunction BiVO4 (OBVV-2) photocatalyst has good potential for application and provides a homojunction solution for efficient and green ammonia nitrogen removal.

Ratiometric fluorescence sensing and discrimination of tetracycline analogs by using coumarin-embedded Eu-MOF nanosensor

As widely used antibiotics, tetracycline residues exist in food and environmental media, which pose certain hidden dangers and negative effects on public health. Therefore, the sensing and discrimination of tetracycline analogs (TCs) have great significance for improving food safety and preventing environmental pollution. Herein, a 7-hydroxycoumarin-3-carboxylic acid-embedded Eu-MOF (HC@Eu-MOF) material was constructed and then developed for the detection of TCs. Upon addition of TCs, the synthesized sensor displays opposite fluorescence changes at two different wavelengths due to the simultaneous presence of the inner filter effect (IFE) and the antenna effect (AE), and achieves a stable ratio signal response within 90 s. In addition, six important tetracycline analogs, including chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TC), metacycline (MC), doxycycline (DC) and demeclocycline (DMC) can be discriminated with 100 % accuracy through the principal component analysis even in extremely complicated mixtures. Further, a smartphone-assisted portable device was applied for visual sensing of TCs. The as-developed platform possessed the characteristics of simple synthesis, fast response, high sensitivity, and high stability, which further lays a further foundation for the on-site visual detection and discrimination of TCs in real samples.

Optimal milling cutter helix selection for period doubling chatter suppression

In high speed milling, interrupted cutting conditions can lead to period doubling chatter vibrations. While many studies have already confirmed that the use of helical tools can effectively shrink or remove these regions of unstable cutting, none of them has provided clear guidance to select the minimum helix that completely cancels the period doubling lobes. This study addresses this gap by introducing a novel analytical formula for a critical tool helix pitch: if the helix pitch is below the critical flip depth of cut of the straight helix cutter multiplied by π, the flip lobes will totally vanish. This rule is not only valuable for chatter-free process planning purposes, but it also establishes exact limit below which the fast and simple zeroth order stability algorithm can provide exact stability boundaries for helical tools. The effectiveness of the formula is numerically corroborated over three different milling scenarios: thin wall milling, slender tool and machine tool structure chatter cases. Finally, the findings are validated through experimental cutting tests.

Simple dynamic stability indicators for characterising and supporting the diagnosis of patients suffering from severe bilateral vestibulopathy

Simple dynamic stability indicators for characterising and supporting the diagnosis of patients suffering from severe bilateral vestibulopathy

Jovian Vortex Hunter: A Citizen Science Project to Study Jupiter’s Vortices

The Jovian atmosphere contains a wide diversity of vortices, which have a large range of sizes, colors, and forms in different dynamical regimes. The formation processes for these vortices are poorly understood, and aside from a few known, long-lived ovals, such as the Great Red Spot and Oval BA, vortex stability and their temporal evolution are currently largely unknown. In this study, we use JunoCam data and a citizen science project on Zooniverse to derive a catalog of vortices, some with repeated observations, from 2018 May to 2021 September, and we analyze their associated properties, such as size, location, and color. We find that different-colored vortices (binned as white, red, brown, and dark) follow vastly different distributions in terms of their sizes and where they are found on the planet. We employ a simplified stability criterion using these vortices as a proxy, to derive a minimum Rossby deformation length for the planet of ∼1800 km. We find that this value of L d is largely constant throughout the atmosphere and does not have an appreciable meridional gradient.