Injection Volume Research Articles

Jet injection through microneedles for large volume subcutaneous delivery

Subcutaneous (SC) drug delivery offers several advantages over intravenous (IV) delivery including: self-administration, improved patient experience, and reduced treatment costs. Unfortunately, each SC delivery is currently limited to ∼ 2.25 mL with IV administration required when the delivery volume exceeds this value. In this work, we explore a new technique for large volume subcutaneous drug delivery that uses microneedles to break through the epidermis then forms the liquid drug into many small jets that penetrate past the ends of the microneedles and into the subcutaneous (or muscle) tissue. By performing multiple simultaneous injections, this delivery approach avoids the volume limitations of SC delivery, and thus may be able to greatly increase the volume we can deliver to this space. Here, we present a novel multi-jet prototype that forms seven simultaneous jets through 30G needles that have been shortened to have an exposed length of just ∼ 1mm. The jet speed, shape, and volume of jets formed through these microneedles are measured to assess the consistency of jet production through the microneedles. We then perform jet injections of volumes up to 3.9 mL into ex vivo porcine tissue. The results demonstrate the successful delivery (>95 %) of 3.9 mL in just 0.3 s using jet injection performed through microneedles. This volume is almost double the maximum volume of current autoinjectors and the perceived limit for subcutaneous injection (2.25 mL). We also find that jet speeds of 70 m/s and below do not achieve complete delivery of 3.9 mL with our prototype system, and that the addition of microneedles leads to more consistent large volume delivery than equivalent needle-free injections. These results demonstrate the promise of multi-jet injection through microneedles to accommodate volumes much greater than current autoinjectors, and thus potentially allow patient self-administration in many more delivery applications.

THE INDUSTRIAL IMPORTANCE OF TECHNOLOGY TRANSFER FOR ANALYTICAL METHOD DEVELOPMENT AND VALIDATION–APPLICATION TO VILAZODONE HYDROCHLORIDE DOSAGE FORM

Objective: The research aims to create a fast, economical, and efficient tech transfer method for analyzing bulk materials and pharmaceutical dosage forms. Methods: The analysis was performed using an Acquity UPLC BEH C18 analytical column (130 Å, 1.7 µm, 3 mm x 100 mm) with detection of the analyte at 238 nm. The mobile phase flow rate was optimized at 0.3 ml/min, and an injection volume of 0.5 µl** was used. The isocratic mobile phase consisted of a blend of buffer (0.1% OPA) and acetonitrile at a ratio of 40:60% v/v. Results: All validation parameters of the analytical method were acceptable. The analyte eluted at 3.08 min with satisfactory theoretical plates and a tailing factor. The recovery of the analyte was 99-100%, and the method's precision was 0.59 and 0.72% RSD. The technique showed no interference, indicating specificity. The linearity was demonstrated over the 20-60 µg/ml range, with a regression coefficient of 0.999. Conclusion: The developed method is cost-effective, specific with minimal interference, and time-saving. It also reduces solvent consumption for quality control analysis of vilazodone hydrochloride samples. The method demonstrates good linearity, robustness, and accuracy.

Interwell channeling and sealing technology in Changqing CCUS block

Abstract In the Changqing Oilfield’s CCUS (Carbon Capture, Utilization, and Storage) project, a novel fracture-based inter-well gas migration sealing technology was developed to address the challenges of reduced production and even shutdown of oil and water wells due to inter-well migration. This was particularly crucial in the context of low fracture pressure-bearing capacity below 40 MPa, the absence of precedents in inter-well gas migration sealing techniques, and the difficulty in accurately estimating the fracture communication volume. The technology is grounded in multi-segment plug water blocking techniques, utilizing geological and well-network data to simulate the gas volume within fractures, thereby determining the precise quantity of plugging agent required. To meet the long-term sealing needs, the technology not only incorporates corrosion-resistant gel in the multi-segment plugs but also integrates water-dispersive cement slurry and CO2 corrosion-resistant cement slurry to enhance the durability of the seal. The injection parameters were optimized based on the pressure-bearing characteristics of the formation to prevent pressure leakage. Field tests indicated that the injection pressure increased by 4 MPa after the application of this technology. Despite the occurrence of gas migration during the plugging process, the close approximation between the designed injection volume of 350 cubic meters and the actual required volume of 326 cubic meters suggests that the technique could achieve its intended effectiveness with further adjustments. This technology provides new insights for handling similar inter-well migration issues in CCUS projects and serves as a reference for other similar endeavors.

Optimizing CO2 Hydrate Sequestration in Subsea Sediments through Cold Seawater Pre-Injection

Carbon sequestration technology offers a solution to mitigate excessive carbon dioxide emissions and sustainable development in the future. This study proposes a method for subsea carbon sequestration through the injection of cold seawater to promote CO2 hydrate formation. Using a self-developed simulator, we modeled and calculated the long-term sequestration process. The study focuses on analyzing the thermal regulation of the seabed following cold seawater injection, the multiphysical field evolution during CO2 injection and long-term sequestration, and the impact of seawater injection volumes on sequestration outcomes. The feasibility and leakage risks of this method were evaluated on a 100,000-year timescale. Results indicate that the injection of cold seawater significantly improves the pressure–temperature conditions of subsea sediments, facilitating early hydrate formation and markedly increasing the initial CO2 hydrate formation rate. Consequently, the distribution pattern of hydrate saturation changes, forming a double-layer hydrate shell. Over the long term, while cold seawater injection does not significantly reduce CO2 leakage, it does increase the safety margin between the hydrate layer and the seabed, enhancing the safety coefficient for long-term CO2 hydrate sequestration. Through detailed analysis of the behavior of CO2 components during sequestration, this study provides new theoretical insights into subsea CO2 hydrate storage.

Feasibility Theory and Practice of CO2-EOR in High CO2-Content Near-saturated Edge-bottom Water Reservoir

Abstract CO2-EOR technology for low-permeability tight oil and gas reservoir is in the ascendant, and CO2-EOR technology for old oilfields has not been paid enough attention, but the implementation scale has great potential, and the expected effect and implementation conditions are good. The feasibility of CO2-EOR technology in the ultra-high water cut stage of high CO2 content, near saturation pressure and edge-bottom water reservoir was studied theoretically, and the field implementation effect was tracked and evaluated. Via petrophysics, reservoir engineering, and site case analysis, a relatively comprehensive reservoir numerical model was developed, clarifying the impact of periodic gas injection volume, gas injection rate, soak time and liquid production rate on the production effect of CO2 huff and puff were clarified. The key injection-production parameters of CO2 huff and puff test wells were designed, and the feasibility study progress of CO2-EOR in near-saturated edge-bottom water reservoirs with high CO2 content was summarized. The theoretical research shows that the change rules of gas-water dual-drive, CO2 water control and oil increase in the process of CO2 huff and puff in high CO2 near-saturated edge and bottom water reservoirs, and reveals the synergistic mechanism of CO2 huff and puff to suppress water and increase energy. The tracking evaluation shows that the sweep condition of CO2 after huff and puff in the test well is complex, the storage ratio is in the range of 40%-70%, the stage oil increase is in the range of 700t-3000t, and the optimized oil increase and oil change rate can reach 2.7t/t. Based on the comprehensive theory and practice, it is considered that CO2-EOR has good potential for high CO2 near-saturated edge and bottom water reservoirs under fine control. This study has guiding and reference significance for CO2-EOR technology and application in similar oilfields at home and abroad.

Development and Application of a Chelating Acid for Water Injection Wells of Chang 6 Reservoir of An-Sai Oilfield

Abstract Ansai oilfield is a typical low permeability, low pressure, low yield and serious heterogeneity oilfield. Chang 6 play of Triassic YanChang Formation is a typical ultra-low permeability reservoir. The average porosity of the reservoir is 10 % ~ 14 %, and the average permeability is (0.2 ~ 4.0) × 10−3 μm2. The absolute content of clay minerals in the reservoir is relatively high, with an average content of 18.61 %. The main components are kaolinite, chlorite, illite and illite/montmorillonite interlayer. Due to the reservoir blockage caused by scaling, water sensitivity and formation particle migration in the process of water injection, high injection pressure and under injection wells is increasing dramatically. In view of the above challenges, a fit-for-purpose acid, which contains organic acids and chelating agents, was developed for injection pressure reduction and injection enhancement. It has the characteristics of strong dissolution, good retarding and corrosion inhibition performance. Corrosion rate is 0.5632 g / (m2·h) for J55 steel in 24h, and the core permeability increases by 74.57 % after acid flooding. It has been applied in field test of 3 wells in Chang 6 layer of Ansai oilfield since March 2024. The average daily injection volume increased by 37.87 %, and the validity period was more than 180 days.

Technology and Research on Improving Oil Recovery by Volume Fracturing with Phase Change Permeability in Ultra-low Permeability Reservoirs

Abstract The conventional water injection development production wells in ultra-low permeability reservoirs have low efficiency, low production and low liquid content, and poor economic benefits. Traditional water drive development techniques are difficult to adapt to the requirements of economically effective development in ultra-low permeability reservoirs. Therefore, it is urgent to adjust development ideas and transform water injection development methods. A major development experiment was carried out in the Y284 area of Huaqing Oilfield to transform the water injection development method. Based on the mechanism of reverse osmosis flooding in oil recovery wells, this article uses dynamic monitoring technologies such as downhole microseismic to achieve three-dimensional reservoir transformation, and establishes a large-scale fracturing technology of “collaborative permeability flooding, volume fracturing, and multi-stage temporary plugging” for reverse osmosis wells in ultra-low permeability reservoirs. Research has shown that large-scale fracturing technology for water injection wells can improve single well oil recovery speed by increasing the complexity of fracture networks. The important factors affecting the effectiveness of water injection wells include reservoir properties, fracturing transformation scale, cumulative water injection volume, remaining oil distribution, and heterogeneity of aquifers. At the same time, the construction parameters of large-scale volume fracturing for water injection wells, namely 140-170m, are quantitatively determined based on the actual situation of the mining field ³ The amount of sand added, a sand ratio of 17-22%, and a large displacement of 8-10m3/min, 1400-2000m ³ The amount of liquid entering the ground can most effectively achieve the conditions for reservoir transformation. The conclusion is that large-scale fracturing technology for conversion wells provides technical support for volume fracturing and optimization design of fracturing parameters for low production wells in ultra-low permeability reservoirs, and can provide guidance and reference for the efficient development of other similar ultra-low permeability reservoirs.

Experimental studies on penetration process of high-speed water-jet into ballistic gelatin

To reveal the penetration mechanism and present the penetration characteristics of high-speed micro-jet with injection volume larger than 0.3mL into soft tissue, the present study conducted experimental research on high-speed water-jet penetration into ballistic gelatin. The free jet dynamics of an air-powered needle-free injector that can emit up to 1.27mL of liquid at once and the penetration dynamics were visualized to reveal the details of the penetration process. In the early unstable stage, the jet is emitted in the form of pulses, and the first jet pulse can rapidly generate an initial slender channel in gelatin in a very short time. In the subsequent stable stage, energy input produces dispersion and further increases the penetration depth slowly. Changing the driving pressure by the power source mainly changes the penetration depth increment by dispersion; while changing the nozzle diameter mainly affects the penetration depth in the initial stage. The central position of the dispersion area in the injection direction was firstly defined in the present work and it was found that an approximate linear relationship between this position and the maximum penetration depth exits for different nozzle diameters and driving pressures when injecting the same liquid dose. These research results can provide a basis for a thorough understanding of the penetration characteristics of high-speed micro-jet with injection volume larger than 0.3mL into soft tissue, as well as the design and operation of the air-powered needle-free injector.

Research on oil well production analysis based on long-term slow-release tracer

Abstract Downhole monitoring the production profile is crucial for the development of oil and gas reservoirs. Currently, the commonly methods for monitoring the production profile include logging tools and using tracer monitoring. The tracer monitoring method is more popular in oil field operations due to its wide applicability, simple process, low cost, low risk, and long monitoring time. However, compared to traditional logging tool monitoring methods, tracer monitoring has drawbacks such as data lag, difficulty in downhole installation, and unstable long-term effects. Bohai Oilfield has developed a new type of solid tracer and solved the problem of downhole installation by improving the structure of the downhole screen tube. This tracer uses polymer material as the skeleton. After entering the designated position, the internal tracer can slowly diffuse into the solvent through the pores in the skeleton, achieving slow release and long-term monitoring of the production profile of the oil well. In 2023, this new type was first applied in the D6 well in Bohai Sea, and a half month stable production stage liquid production profile was obtained through sampling. The monitoring results showed that: (1) Solid slow-release tracer monitoring technology can continuously obtain production layer information in complex environments and can be used for short-term rapid water exploration and long-term water production monitoring, identifying water breakthrough time and main water breakthrough location, (2) The distance between water injection well and D6 production wells is small, and the water injection volume in the injection wells is large. The tracer monitoring results show that there is a certain degree of water flooding in all 6 sections of each test layer, (3) The first test layer is the main liquid production section, the first and sixth test layers are the main oil production sections, and the first and second test layers are the main water production sections. The research results can determine the oil and water production situation of each section of oil well, identify the water breakthrough time and water outlet position, and provide a basis for the next development adjustment.

Particle-in-cell simulations of pulsar magnetospheres: Transition between electrosphere and force-free regimes

Aims. Global particle-in-cell (PIC) simulations of pulsar magnetospheres are performed with volume-, surface-, and pair-production-based plasma injection schemes to systematically investigate the transition between electrosphere and force-free pulsar magnetospheric regimes. Methods. We present a new extension of the PIC code OSIRIS that can be used to model pulsar magnetospheres with a two-dimensional axisymmetric spherical grid. The subalgorithms of the code and thorough benchmarks are presented in detail, including a new first-order current deposition scheme that conserves charge to machine precision. Results. We show that all plasma injection schemes produce a range of magnetospheric regimes. Active solutions can be obtained with surface and volume injection schemes when using artificially large plasma-injection rates, and with pair-production-based plasma injection for sufficiently large separation between kinematic and pair-production energy scales.

Improving transient gene expression and agroinfiltration‐based transformation effectiveness in Indonesian orchid Phalaenopsis amabilis (L.) Blume

Transient gene expression is an approach used to study transient genes across various species, with infiltration by Agrobacterium tumefaciens (agroinfiltration) being a commonly used method. Agroinfiltration offers a simple and effective means of delivering transgenes into the plant genome. An alternative method for enhancing the quality and productivity of orchids as ornamental plants is genetic modification through agroinfiltration. Although Agrobacterium‐mediated genetic transformation by immersion has been used on the Phalaenopsis amabilis (L.) Blume species of orchid, transformation efficiency using the immersion technique remains relatively low and the method itself is challenging due to its requirement for aseptic handling. The application of agroinfiltration in P. amabilis has not previously been reported. This study investigates the impact of the injection site, acetosyringone concentration, bacterial density (OD600), and injection volume to determine the optimum conditions for agroinfiltration on P. amabilis. The results demonstrated that injection site had a noticeably distinct impact on transformation effectiveness, with the abaxial position of the leaf being the optimal site for Agrobacterium culture suspension injection. While adjustments in acetosyringone concentration, bacterial density (OD600), and injection volume did not significantly affect transformation efficiency, they did influence the peak time of GFP fluorescence. Acetosyringone at a concentration of 200 µM, an OD600 of 1.0 for Agrobacterium culture, and an injection volume of 500 µL effectively accelerated GFP expression duration.

Oxidative stress causes liver injury via the damage of redox system and the apoptosis induced by mitochondria of broiler

The aim of this study was conducted to explore the effects of oxidative stress on the redox system, mitochondrial function, and apoptosis in liver of broilers. 144 one-day-old male Ross-308 broilers from the same batch had been prepared in advance and were divided into 3 treatments: normal control group (without intraperitoneal injection), normal saline group (intraperitoneal injection of normal saline), and hydrogen peroxide (H2O2) group (intraperitoneal injection of H2O2) with 6 replicates of 8 chickens each. The experimental period was 42 days. The injection volumes were 1.0 mL/kg of Ross-308 broiler body weight. On the 42nd day of the experimental period, two Ross-308 broilers were randomly selected from each cage, a total of 36 broilers were stunned by electric shock and slaughtered to collect liver samples. The results showed that compared with the non-injection group and the injection of saline group, H2O2 exposure elevated the relative weight of liver and the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum of Ross-308 broilers (p < 0.05). Meanwhile, compared with the non-injection group and the injection of saline group, the H2O2 exposure increased the levels of reactive oxygen species (ROS), MDA, lipid peroxide (LPO) and protein carbonyl, decreased the activities of total superoxide dismutase (T-SOD), catalase (CAT), total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) (p < 0.05). Compared with the non-injection group and the injection of saline group, the H2O2 exposure caused microvesicular steatosis and mitochondrial vacuolisation in the liver tissues of broilers. Additionally, after H2O2 exposure, the levels of nuclear factor erythroid 2–related factor 2 (Nrf2) positive cells were reduced and the relative percentage of hepatocyte apoptosis were increased in the liver tissues of broilers (p < 0.05). The conclusion of this study is that the oxidative stress induced by intraperitoneal injection of H2O2 could induce excessive production of ROS in broiler liver, which damage the antioxidant status and mitochondrial function of liver cells, leading to cell apoptosis. HIGHLIGHTS Oxidative stress can cause severe damage to the liver of broilers. Oxidative stress can mainly damage liver antioxidant function Oxidative stress can induce cell apoptosis by damaging mitochondria in the liver of broilers

Investment attractiveness of agricultural enterprises as a factor in ensuring their competitiveness

Purpose - the study of theoretical and practical aspects of investment attractiveness of agricultural enterprises in Kazakhstan based on the analysis of the volume of attracted investments in the agro-industrial complex. Methods - research, descriptive and analytical types of strategies are used in combination with methods of formalization, abstraction, statistical processing and visualization of data. Results - in the authors' opinion, despite the fact that the agrarian sector is economically and socially significant for the rural areas of the republic, it remains unattractive for investors. Investment in the agrarian sector and the growth of investment projects in the agro-industrial complex are constrained by the acute shortage of financial resources, underdeveloped material, technical and technological base, and low effective demand of the population. Investments form the production potential and determine the competitive position of regions. The article considers the problems that hinder the increase in investment activity. The role of the state in the management of investment processes is revealed. The factors hindering the inflow of investment and measures to increase the volume of financial injections into agriculture are shown. Conclusions - creation of favorable investment climate in agro-industrial production and activation of investment activity of economic entities is one of the most urgent tasks of agro-industrial complex development. Based on the realities of the economic situation in the agricultural sector, it is necessary to mobilize its internal reserves, the formation of an effective market infrastructure, the growth of solvency of agricultural producers, the strengthening of state support. Only in this case the conditions for investment attractiveness will be formed and the degree of saturation of the food market of the country with the products of own production will increase, the possibility of renewal of fixed assets of the industry will appear.

Determination of deoxynivalenol and metabolites in maize samples by LC-MS/MS

In Vietnam, the regulation QCVN 8-1:2011/BYT has been issued to control mycotoxin content in food products. However, there are currently no regulations or studies on their derivatives and metabolites. Deoxynivalenol-3-glucoside (D3G) and two acetylated derivatives of deoxynivalenol (DON), namely 15-acetyldeoxynivalenol (15-AcDON) and 3- acetyldeoxynivalenol (3-AcDON), have been frequently detected in naturally contaminated grains such as wheat, barley, and corn. This study developed and applied a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine deoxynivalenol (DON) and its metabolites, including deoxynivalenol-3-glucoside (D3G), 3- acetyldeoxynivalenol (3-AcDON), and 15-acetyldeoxynivalenol (15-AcDON) in maize. The instrumental conditions comprised a C18 HSS SB (150 mm &amp;times; 2.1 mm &amp;times; 1.7 &amp;micro;m) column for separation and an MS/MS detector in positive and negative electrospray ionization (ESI) source, employing multi-reactive ion monitoring mode, with an injection volume of 2 &amp;micro;L. The method has been fully validated and meets the performance requirements of AOAC, demonstrating high specificity. The linearity range was established from 100 &amp;micro;g/kg to 1000 &amp;micro;g/kg, with a method detection limit (MDL) of 30 &amp;micro;g/kg. The repeatability and recovery rates were determined to be between 1.45% to 4.31% and 90% to 110%, respectively. The validated method was applied to analyze 50 maize samples. Deoxynivalenol (DON) was detected in 10 samples (20%), while deoxynivalenol-3-glucoside (D3G), 3- acetyldeoxynivalenol (3-AcDON), and 15-acetyldeoxynivalenol (15-AcDON) were not detected in any of the samples.

Simultaneous determination of acid carnosic and carnosol in rosemary-containing foods by high-performance liquid chromatography with photodiode array detection (HPLC–PDA)

The research was conducted to develop and validate a simultaneous quantification method for acid carnosic (CA) and carnosol (CAR) in rosemary-containing foods using highperformance liquid chromatography coupled with photodiode array detection (HPLC&amp;ndash;PDA), with a simple and fast sample processing procedure. Analytical samples were extracted using a methanol&amp;ndash;phosphoric acid mixture (99.5:0.5, v/v) at room temperature for 20 minutes. The chromatographic conditions were as follows: Sunfire C18 column (4.6 mm x 250 mm; 5 &amp;micro;m), mobile phase consisting of 0.1% phosphoric acid &amp;ndash; acetonitrile (40:60, v/v), flow rate of 1 mL/min, injection volume of 10 &amp;micro;L, detection at 230 nm. The method was validated according to the Association of Official Analytical Chemists (AOAC) criteria. The results showed that the method had good specificity, and the standard curves of acid carnosic and carnosol were linear in the concentration range of 2.5 &amp;ndash; 200 &amp;micro;g/mL. The limits of detection (LOD) for acid carnosic and carnosol were 0.3 &amp;micro;g/mL and 0.25 &amp;micro;g/mL, respectively. The limits of quantification (LOQ) for acid carnosic and carnosol were 1 &amp;micro;g/mL and 0.75 &amp;micro;g/mL, respectively. The recovery rates were in the range of 98.8 &amp;ndash; 100.6% (acid carnosic) and 97.5 &amp;ndash; 102.2% (carnosol). Repeatability and internal reproducibility met the requirements of AOAC. The method was applied to evaluate the acid carnosic and carnosol levels in 20 food samples collected from the market, such as rosemary leaf powder, dried rosemary leaves, rosemary herbal tea,...

Large scale screening and quantification of micropollutants in fish from the coastal waters of Cochin, India: Analytical method development and health risk assessment

Urban estuarine and coastal water receive several micropollutants through industrial and agricultural influxes. The bioaccumulation of these micropollutants in fish and their entry into the coastal population's food chain raises significant food safety concerns. Hence, a comprehensive analytical method was developed for ultra-trace level quantification of 345 micropollutants in fish. The optimized sample preparation method could extract compounds suitable for both GC–MS/MS and LC-MS/MS analysis simultaneously. The target list of contaminants included 278 agricultural pesticides and also 102 endocrine disruptors covering polyaromatic hydrocarbons, polychlorinated biphenyls, organochlorines, and endocrine-disrupting pesticides. The GC–MS/MS with large volume injection (LVI) technique, and LC-MS/MS operating in MRM mode, achieved an LOQ of <2.00 ng/g for most of the analytes. The extraction strategy involved tri-phase partitioning between water, acidified acetonitrile, and hexane, followed by salting out. Dispersive solid phase cleanup (dSPE) with C18, Z-Sep+, CaCl2, and MgSO4 was able to reduce the matrix influence, and the method achieved satisfactory recovery in the range of 70.0–120.0 % for all the target analytes. The repeatability and reproducibility relative standard deviation values of the measured analytes were <20.0 %, and the Horwitz ratio values were well below 2. The method was used to accurately measure the target micropollutants in fish from the Cochin estuary, the highly urbanized portion of the Vembanad Lake, and an important Ramsar site. At least one or more of the 41 different micropollutants were identified and quantified in about 90.7 % of the 108 samples analyzed. The importance of large-scale screening and trace-level quantification methods in environmental monitoring and risk assessment is underscored by the results. The risk assessment showed a moderate risk of exposure to the nearby coastal population through the food chain.

Analysis of Total Microcystins using LC-MS/MS: Method Improvements and Sample Applications

Microcystin variants (MCs), including microcystin-LR (MC-LR) and related variants, are produced by cyanobacteria and are regulated due to their potential health risks. Current methods for MC analysis predominantly employ LC-MS/MS, limited by the availability of reference materials necessary for quantification. As an alternative method for total MC quantification, the analysis of 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB), formed by oxidation of the common ADDA structure in MCs, offers economic and practical advantages by avoiding the need for multiple MC reference materials. This method allows total MC quantification across various matrices, independent of specific MC variants. In this study, we evaluated the utility of MMPB-d3 as a surrogate to assess recovery rates throughout the processes critical for MMPB quantification. Comparative analysis with 4-phenylbutyric acid (4-PB) highlighted the stability of MMPB-d3 under oxidative conditions, which is critical for its application as a surrogate or internal standard. The oxidation process was optimized to achieve consistent recovery rates, averaging 101%, ensuring reliable conversion of MCs to MMPB for subsequent analysis. The limit of quantification (LOQ) has been improved due to the large volume injection of up to 0.1 µg/L. Comparison of MMPB concentrations from field samples with conventional LC-MS/MS results showed a significant correlation (r = 0.80, p &lt; 0.005), but with variations in the absolute concentrations. Calculations using a formulation model with MMPB concentrations allowed us to estimate total MC levels, demonstrating the potential of the proposed method to complement existing target measurement techniques.

A sustainable RP-HPLC method for concurrent estimation of capecitabine and celecoxib in liposomal formulation: Greenness and whiteness appraisal.

Liposomes have been reported for combination therapy due to their ability to carry both hydrophilic and lipophilic drugs together. The current investigation aims to develop a novel, eco-friendly, and sustainable reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous quantification of capecitabine and celecoxib co-encapsulated in liposomes. The method reported herein uses a C18 column (4.6 × 250 mm2, 5 μm) and a mobile phase consisting of water, and acetonitrile/methanol in a ratio of 60:40, containing 0.1% formic acid in both the phases. The flow rate is maintained at 1 mL/min, with an injection volume of 10 μL in the gradient mode. Detection is set at λmax = 240 nm for capecitabine and 252 nm for celecoxib. The developed liposomes are mono-disperse with a surface potential of -6.93 mV. The average size of the liposomes is 142 nm. The percentage entrapment efficiency for capecitabine is 52.39 ± 0.94%, and for celecoxib, it is 77.13 ± 0.74%. The Analytical Greenness Metric of 0.61 and Analytical Eco-Scale Score of 75 signify the greenness of the developed method. Also, the Red-Green-Blue model shows excellent whiteness, with a score of 83.2. Thus, the developed method offers a reliable, accurate, precise, buffer-free, and environment-friendly RP-HPLC approach for the simultaneous analysis of capecitabine and celecoxib co-encapsulated in liposomes.

New exploration on the goaf inerting with hidden fire source under CO2 injection volume of adsorption compensation

To strengthen the rationality of the design of CO2 injection volume in goaf, a framework is proposed to study goaf inerting characteristics with hidden fire sources under CO2 injection volume of adsorption compensation. The zone of hidden fire source is determined by similar simulation experiment of coal spontaneous combustion on a working face of coal mine. The range of injection volume without adsorption is calculated theoretically. A three-dimensional initial flow field model of coal spontaneous combustion is established combined with field measurement. The error of oxidation zone width is 3.64 %, which verifies the reliability of model. The influence of injection volume on the inerting effect in goaf is studied, and optimal injection volume without adsorption is 1000 m3/h. Based on the relationship between adsorption capacity and temperature, a quantization model of injection volume with adsorption compensation is established. The maximum dissipation ratio is then proposed. The optimal injection volume after adsorption compensation is calculated. The results show that intermittent injection of gaseous CO2 is recommended under simulated conditions. The maximum dissipation ratio is 1/4, and the CO2 injection volume compensated by adsorption is 1333 m3/h. The research results can provide theoretical guidance for the optimization of CO2 inerting parameters in goaf.

Effects on upper masonry structures caused by double-line parallel shield cutting group pile construction

The effects on the upper masonry structure and the construction parameters of shield cutting piles were studied during shield construction, focusing on a shield interval of Zhengzhou Metro Line 5. The study utilized the actual engineering case of left and right double-lane shields superimposed on cutting cement soil group pile composite foundations beneath masonry structures. Findings revealed that masonry structures within approximately 30 m (5.0 times the tunnel diameter) were impacted before and after shield cut pile construction, resulting in deflection and twisting deformations of houses along the central axes of the left and right tunnel lines. Implementation of “clay shock” grouting outside the shield shell, radial grouting through small conduits, shield tail synchronous grouting, and secondary reinforcement grouting effectively mitigated the disturbance caused by shield construction to the ground. When shield cut piles passed beneath masonry structures, pressure on the soil chamber, total thrust, and cutterhead speed were consistently controlled. Furthermore, the cutterhead torque was appropriately reduced, and slurry injection volume increased, contributing to better control of house settlement.