Coupling simulation of pipeline nodes - Storage tank linkage in urban high-density built-up areas using optimization model

Climate change and urbanization contribute to the increased frequency of short-duration intense rainstorms. Traditional solutions often involve multiple scenarios for cost-effectiveness comparison, neglecting the rationality of placement conditions. The effective coupling and coordination of the location, number, size, and cost of storage tanks are crucial to addressing this issue. A three-phase approach is proposed to enhance the dynamic link between drainage pipeline and storage tanks in urban high-density built-up areas, integrating Python language, SWMM, the Elitist Non-Dominated Sorting Genetic Algorithm (NSGA-III), and the Analytic Hierarchy Process (AHP) methods. In the first stage, each node within the pipeline network is considered as a potential storage tank location. In the second stage, factors such as the length and diameter of the upstream connecting pipeline, as well as the suitability of the storage tank location, are assessed. In the third stage, the length and diameter of the downstream connecting pipeline node are evaluated. The results show that the 90 overflow nodes (overflow time >0.5h) have been cleared using the three-phase approach with a 50a (duration = 3h) return period as the rainfall scenario, which meets the flooding limitations. After the completion of the three-phase method configuration, the total overflow and SS loads were reduced by 96.45% and 49.30%, respectively, compared to the status quo conditions. These two indicators have decreased by 48.16 and 9.05%, respectively, compared to the first phase (the traditional method of only replacing all overflow nodes with storage tanks). The proposed framework enables decision-makers to evaluate the acceptability and reliability of the optimal management plan, taking into account their preferences and uncertainties.

Nonlinear differential equations and their application to evaluating the integrated impacts of multiple parameters on the biochemical safety of drinking water

The present study aimed to narrow such gaps by applying nonlinear differential equations to biostability in drinking water. Biostability results from the integrated dynamics of nutrients and disinfectants. The linear dynamics of biostability have been well studied, while there remain knowledge gaps concerning nonlinear effects. The nonlinear effects are explained by phase plots for specific scenarios in a drinking water system, including continuous nutrient release, flush exchange with the adjacent environment, periodic pulse disinfection, and periodic biofilm development. The main conclusions are, (1) The correlations between the microbial community and nutrients go through phases of linear, nonlinear, and chaotic dynamics. Disinfection breaks the chaotic phase and returns the system to the linear phase, increasing the microbial growth potential. (2) Post-disinfection after multiple microbial peaks produced via metabolism can increase disinfection efficiency and decrease the risks associated with disinfectant byproduct risks. This can provide guidelines for optimizing the disinfection strategy, according to the long-term water safety target or a short management. Limited disinfection and ultimate disinfection may be more effective and have low chemical risk, facing longer stagnant conditions. (3) Periodic biofilm formation and biofilm detachment increase the possibility of uncertainty in the chaotic phase. For future study, nonlinear differential equation models can accordingly be applied at the molecular and ecological levels to further explore more nonlinear regulation mechanisms.

Hydrodynamic behavior of freshwater-saltwater mixing zone in the context of subsurface physical barriers

The seawater intrusion (SWI) process lasts for decades in real world, thus the research on dynamic process of SWI is essential. The freshwater-saltwater mixing zone plays a crucial role in governing the groundwater movement and the solute transport in coastal aquifers. To date, there has been a lack of research on the hydrodynamic behavior of the mixing zone in the presence of subsurface physical barriers. In this work, we employed laboratory experiments and numerical simulations to investigate the dynamics of the mixing zone, comparing scenarios with and without subsurface physical barriers. The findings indicate that the construction of a subsurface physical barrier will not immediately slow down the seawater intrusion velocity and change the salinity distribution of mixing zone. The block effect of subsurface physical barriers with different heights or bottom opening sizes became apparent only when the wedge toe approached the physical barriers. The widening effect of increasing longitudinal dispersivity on the mixing zone width was more pronounced during the dynamic process compared to the steady state. Furthermore, the widening effect of increasing longitudinal dispersivity on the mixing zone was more significant compared to transverse dispersivity in both the SWI and subsurface dam scenarios throughout the intrusion process. However, in the cutoff wall scenarios, the widening effect of increasing transverse dispersivity became more obvious during the later intrusion period. Our conclusions provide a reference for the groundwater management in coastal aquifers. According to the current seawater intrusion situation, the local water bureau can predict the seawater intrusion velocity and the temporal changes of mixing zone after the construction of physical barriers.

Dynamic changes in resilience among family caregivers in the face of healthcare challenges: A scoping review

BACKGROUND

Resilience as a dynamic concept has already been described through various longitudinal studies. To better understand the changes in the resilience of caregivers over the course of care-providing, however, a scoping review can provide a clearer picture of their resilience process which, in turn, can be used to improve caregivers' well-being.

OBJECTIVES

To provide a comprehensive overview of dynamic change in the resilience of caregivers while caring for the family to enhance understanding and potential for future research.

METHODS

Following the methodological framework of Arksey and O'Malley, this scoping review was conducted using the Preferred Reporting Items for Systematic Reviews and the Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist. Five electronic databases were searched for research published in English between January 2012 and May 2022, after which a manual search was performed. Key terms related to resilience and caregivers in longitudinal studies were included and screened for. Identified trajectories of patterns in resilience and factors associated with resilience process were categorized using content analysis.

RESULTS

In total, 24 longitudinal studies met the eligibility criteria. Conceptually, our findings demonstrate three modes of change following healthcare challenges, each of which varies substantially. Methodologically, the results reveal three subcategories of assessment tools that can be used to impact caregivers' resilience when confronted with significant healthcare challenges. Consequentially, personal traits and environmental resources interacting with the resilience process will then lead to various outcomes in their resilience, including stability, growth, or decline.

CONCLUSION

This review describes the change patterns of the resilience process, assessment instruments, and associated factors to offer a dynamic perspective for the investigation and intervention of psychological resilience. Major gaps nonetheless remain for future research regarding an operationalizing dynamic change in resilience.

Phototriggered structures: Latest advances in biomedical applications

Non-invasive control of the drug molecules accessibility is a key issue in improving diagnostic and therapeutic procedures. Some studies have explored the spatiotemporal control by light as a peripheral stimulus. Phototriggered drug delivery systems (PTDDSs) have received interest in the past decade among biological researchers due to their capability the control drug release. To this end, a wide range of phototrigger molecular structures participated in the DDSs to serve additional efficiency and a high-conversion release of active fragments under light irradiation. Up to now, several categories of PTDDSs have been extended to upgrade the performance of controlled delivery of therapeutic agents based on well-known phototrigger molecular structures like o-nitrobenzyl, coumarinyl, anthracenyl, quinolinyl, o-hydroxycinnamate and hydroxyphenacyl, where either of one endows an exclusive feature and distinct mechanistic approach. This review conveys the design, photochemical properties and essential mechanism of the most important phototriggered structures for the release of single and dual (similar or different) active molecules that have the ability to quickly reason of the large variety of dynamic biological phenomena for biomedical applications like photo-regulated drug release, synergistic outcomes, real-time monitoring, and biocompatibility potential.

Adsorption of glycine at the anatase TiO2/water interface: Effects of Ca2+ ions

Adsorption reactions of amino acids (AAs) on TiO₂ nanoparticles (NPs) play an important role in the available nutrients in soils and sediments. The pH effects on glycine adsorption have been studied, but little is known about its coadsorption with Ca²⁺ at the molecular level. Combined attenuated total reflectance Fourier transform infrared (ATR-FTIR) flow-cell measurements and density functional theory (DFT) calculations were used to determine the surface complex and corresponding dynamic adsorption/desorption processes. The structures of glycine adsorbed onto TiO₂ were closely associated with its dissolved species in the solution phase. The presence of Ca²⁺ exerted different influences on glycine adsorption within pH 4-11, thus affecting its migration rate in soils and sediments. The mononuclear bidentate complex at pH 4-7, involving the COO^- moiety of zwitterionic glycine, remained unchanged in the absence and presence of Ca²⁺. At pH 11, the mononuclear bidentate complex with deprotonated NH₂ can be removed from the TiO₂ surface upon coadsorption with Ca²⁺. The bonding strength of glycine on TiO₂ was much weaker than that of the Ca-bridged ternary surface complexation. Glycine adsorption was inhibited at pH 4 but was enhanced at pH 7 and 11.

Underestimated permafrost degradation: Improving the TTOP model based on soil thermal conductivity

Under the continuing influence of global warming, resolving the inconsistency of permafrost degradation rates and quantifying the spatial distribution characteristics are critical for high-altitude water cycle processes. The dynamics of permafrost degradation are mainly manifested in soil temperature, which can be measured with high accuracy and high temporal resolution. This study considered the influence of soil thermal conductivity (K) by periodic land surface temperature (LST), improved the static output of the temperature at the top of permafrost (TTOP) model, and verified the reliability of the TTOP model improvement by the Kappa coefficient. The results showed that from 2000 to 2020, the extent of dynamically simulated permafrost was 5.42 × 105 km2 less than that of static simulated permafrost, and the linear degradation rate doubled. The degraded permafrost showed an increasing degradation from southeast to northwest. Among them, the degradation in the Nujiang River and the Changjiang River north of the Nyainqentanglha Mountain has exacerbated the permafrost degradation in the hinterland of the Qiangtang Plateau. Based on the AWI-CM-1-1-MR LST from CMIP6, SSP126 to SSP585 dynamic simulation results of permafrost indicate that the extent will decrease by 11.35 % by 2100. Overall, the extent and rate of permafrost degradation, considering high spatiotemporal resolution, were twice as fast as expected. Our results will inform policymakers with a more accurate spatiotemporal distribution of frozen soil types in high-altitude regions and characteristics of permafrost degradation within the watershed.

Semi-supervised echo state network with temporal-spatial graph regularization for dynamic soft sensor modeling of industrial processes

Echo state network (ESN) has been successfully applied to industrial soft sensor field because of its strong nonlinear and dynamic modeling capability. Nevertheless, the traditional ESN is intrinsically a supervised learning technique, which only depends on labeled samples, but omits a large number of unlabeled samples. In order to eliminate this limitation, this work proposes a semi-supervised ESN method assisted by a temporal-spatial graph regularization (TSG-SSESN) for constructing soft sensor model with all the available samples. Firstly, the traditional supervised ESN is enhanced to construct the semi-supervised ESN (SSESN) model by integrating both unlabeled and labeled samples in the reservoir computing procedure. The SSESN computes the reservoir states under high sampling rate for better process dynamic information mining. Furthermore, the SSESN's output optimization objective is modified by applying the local adjacency graph of all training samples as a regularization term. Especially, in view of the dynamic data characteristic, a temporal-spatial graph is constructed by considering both the temporal relationship and the spatial distances. The applications to a debutanizer column process and a wastewater treatment plant demonstrate that the TSG-SSESN model can build much smoother model and has better generalization capability than the basic ESN models in terms of soft sensor prediction results.

New insight for the diffusion-resupply kinetics of Cr(VI) in contaminated soil using DGT/DIFS

Chromium (Cr) is a widespread pollutant with high toxicity and mobility. However, the diffusion-resupply kinetics of Cr(VI) between the solid phase and solution in the soils remain unclear. Here, we quantified the contributions of the soil solution and solid phase to the diffusion-resupply process of Cr(VI) in the contaminated soils using the diffusive gradients in thin-films (DGT) and DGT-induced fluxes in soils model. Based on the solution extraction result, Cr(VI) was the main available Cr species in the contaminated soils. Comparing the two diffusion-resupply stages of the kinetic process, the potential hazards due to the resupply from the solid phase can reach 10.71-50.66 %, although the soil solution accounted for the largest proportion of the effective concentration of Cr(VI) (49.34-89.29 %), which was ignored in the traditional equilibrium method. The kinetic parameters can be used to interpret the dynamic process. The resupply ability of the solid phase was closely related to the response time (T_c). The longer T_c was consistent with the low desorption constant, indicating a kinetic limitation. The magnitude of the resupply from the solid phase was related to labile pool size of Cr(VI) and soil organic carbon content. This study established a new quantification method for assessing diffusion-resupply kinetics of Cr(VI) in the soil， indicating the underestimation of Cr(VI) risk based on the use of traditional equilibrium methods. Our data provided a scientific basis for ecological risk assessment, pollution prevention, surface- and groundwater control, and environmental governance in areas with Cr contaminated soil.

Effects of biowaste-derived biochar on the dynamic behavior of cadmium fractions in soils

As a commonly used amendment to soil contaminated by heavy metals, biochar has attracted great attention and has been applied for decades due to the benefits to the soil. However, the effects of biochar on the dynamic behavior of soil properties and metal fractions are still unclear. Here, we used two biochars, derived from biowastes (reed and bamboo willow), to treat two cadmium (Cd)-contaminated soils, S1 (loamy sand) and S2 (sandy loam), and determined the dynamic effects. The incubation experiments were designed to investigate the effects of biochar on the dynamic behavior of soil pH, dissolved organic matter (DOM), bioavailable Cd, and the transformation of Cd fractions for 270 days. The results showed that the soil pH, DOM, and bioavailable Cd initially increased and then decreased with incubation time, and the soil pH and DOM were higher, but bioavailable Cd content was lower than the original value. The transformation of the metal fractions changed dynamically, and the exchangeable fraction of Cd decreased with incubation time. Furthermore, the correlation results showed that the DOM can directly control the redistribution of Cd fractions, while soil pH can control it indirectly by regulating the DOM. This study highlighted that biochar can affect soil pH and DOM, redistribute Cd fractions, decrease bioavailable Cd content, and lower the potential risk of heavy metals. This study suggests ways to immobilize heavy metals in contaminated soils using biochar.

Migration and distribution of cadmium in aquatic environment: The important role of natural biofilms

For a better understanding of the migration process of trace metals in aquatic environment with multiple phases, dynamic processes of Cd reaching quasi-equilibrium among different phases, including water, natural biofilms and surficial sediments, were investigated, using microcosmic simulating systems. The processes of the re-equilibrium of Cd after a supplement of Cd and after an adjustment of solution pH were also investigated. The results showed both the migration of Cd from water to the solid materials, and the accumulation of Cd in the solid materials. (Modified) pseudo-second-order kinetic model can be used to simulate such processes. However, Cd content in biofilms and sediments varied in different ways: Cd in biofilms increased rapidly at first, then decreased, and finally approached constancy, while Cd in sediments increased slowly and continuously. The more the Cd was added in the water, the higher the Cd contents in solid phases, and the quicker the Cd accumulation and decrease process would be. The decrease of solution pH promoted the release of adsorbed Cd from the solid phases, especially from biofilms, while the increase of pH stimulated the migration of Cd to the solids. Therefore, as an indicator and temporary reservoir of trace metals in water, which respond rapidly to the variation of trace metal concentration in water, biofilms play a role in indicating and buffering the variation of trace metals in water. Although the response of sediments to the variation of metal concentration in water is very slow, most trace metals migrate to sediments eventually, thus sediments play a role as a more stable and massive reservoir for trace metals in water.

Dynamic construction of gut microbiota may influence allergic diseases of infants in Southwest China

Background

Gut microbes have been suggested as the possible targets in the management of allergic diseases. However, the way in which these microbes influence allergic diseases remain unclear. Forty-seven full-term newborns were selected from a 1000-infant birth cohort. Among them were 23 allergic infants, whereas 24 infants were healthy without allergic symptoms at 1 year of age. Two hundred and sixty-four fecal samples were collected at 7 time points following their birth. These fecal samples were microbiologically analyzed using 16S rRNA gene sequencing. The dynamic processes involved in gut microbiota diversity and composition in the tested infants were constructed.

Results

Healthy infants demonstrated more statistical differences in longitudinal changes in the alpha diversity of their microbiota at the time points compared with day 0 (meconium) than did allergic infants. Analysis of beta diversity showed that the fecal microbiota of days 0 and 2 comprised different communities in healthy infants, and that there were three separate communities in the fecal microbiota of day 0 of the healthy infants, those of day 2 of the healthy infants, and those of days 0–2 of the allergic infants. The relative abundance of dominant gut microbiota at phylum level varied at different time points in the healthy and diseased groups. Bifidobacterium, Escherichia-Shigella, Streptococcus, Clostridium_sensu_stricto_1, Akkermansia and Erysipelatoclostridium were significantly different between the healthy and diseased groups at a different time points.

Conclusion

The dynamic construction processes of gut microbiota during early life might be associated with the occurrence of long-term allergic diseases, with the first month following birth potentially being the most critical.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1489-4) contains supplementary material, which is available to authorized users.

A donepezil/cyclodextrin complexation orodispersible film: Effect of cyclodextrin on taste-masking based on dynamic process and in vivo drug absorption

The aim of this study was to develop a palatable donepezil (DP) orodispersible film (ODF) to facilitate the swallowing process and investigate the effect of cyclodextrin on taste-masking based on dynamic process and in vivo drug absorption. Complexation of DP with hydroxypropyl-β-cyclodextrin (HP-β-CD) was applied to mask the bitter taste then the prepared complexes were incorporated into ODF using solvent casting method. The taste-masking efficiency was evaluated by e-tongue; meanwhile the pharmacokinetic behavior of DP/HP-β-CD ODF was investigated by in vivo study. Results showed the optimized film was more palatable than donepezil hydrochloride (DH) film and was bioequivalent with DH. The molecular mechanism was revealed by phase solubility study, Fourier-transform infrared spectrometer (FT-IR), Differential scanning calorimeter (DSC), X-ray diffraction (XRD) and molecular modeling. Taste-masking was attributed to the formation of DP/HP-β-CD which was due to moderate interaction between DP and HP-β-CD. The stability of DP/HP-β-CD was decreased because of the acid environment in stomach, which facilitated the absorption of DP. These results extended our understanding about the application of cyclodextrin complexation and provided guidance for the design of ODF especially for drugs with disgusting taste.

Fault detection and diagnosis based on particle filters combined with interactive multiple-model estimation in dynamic process systems

A new approach to fault detection and diagnosis (FDD) is developed for nonlinear stochastic dynamic process systems in this paper. It is called PFs-IMM, which combines particle filters (PFs) and the interactive multiple model (IMM) estimation. In this method, a multiple-model estimation scheme is first formulated to describe the complex process system poorly represented by a single model. The IMM algorithm can deal with abrupt changes in the behavior of operating processes. The residuals of the multiple models are examined for the likelihood of each model. A decision rule is employed to adaptively determine which model is the most appropriate one at each time step. Then based on IMM, a set of PFs run in parallel is used to estimate the states and the reconciled measurements even when the operating mode changes. Each of the PFs utilizes a particular mode to derive the estimation of the state variables as well as the reconciliation of the measured variables based on the probabilistic weighting scheme. From the multiple filters, the interaction among PFs allows the fusing of dynamic estimates. To achieve higher sensitivity to faults and more robustness to disturbances and noises, a new fault index function is developed for FDD. The proposed PFs-IMM approach provides an integrated framework. It can estimate the current operational or faulty mode of the system and derive the overall state estimation and the measurement reconciliation as well. The simulation solutions to the problems are obtained to demonstrate the effectiveness of the proposed method in highly nonlinear dynamic processes.

Characterizing Protein Dynamics with NMR R 1ρ Relaxation Experiments

The measurement of R_1ρ , the longitudinal relaxation rate constant in the rotating frame, is one of the few available methods to characterize the μs-ms functional dynamics of biomolecules. Here, we focus on ¹⁵N R_1ρ experiments for protein NH groups. We present protocols for both on- and off-resonance ¹⁵N R_1ρ measurements needed for relaxation dispersion studies, and describe the data analysis for extracting kinetic and thermodynamic parameters characterizing the motional processes.

Electrochemical assay for continuous monitoring of dynamic DNA methylation process

A simple electrochemical strategy is reported for continuous monitoring of dynamic DNA methylation process over time. An electrochemical sensor was prepared by co-assembling of DNA probe and 6-mercapto-1-hexanol onto a gold electrode. The top of the DNA probe was labeled with 6-ferrocenylhexanethiol modified gold nanoparticle. The charge density between the C•G base pair was verified to be slightly reduced by DNA methylation, and could be further decelerated by ~ 25% upon co-locating a Br group onto methylated cytosine (mC). Therefore, in the presence of NaIO₄/LiBr, the progressively methylated DNA on the sensor showed a clearly decreasing current over methylation time. The dynamic DNA methylation process was indicated continuously from the current decrease ratio, with a limit of detection of 0.0372µM. The strategy is convenient, cost-effective, and enable continuous profiling methylation process without distortion. Besides, the strategy was successfully applied for the studies on inhibitor screening and flanking sequence preference of DNA methyltransferase 3a. The results show that the activity of DNA methyltransferase 3a can be mildly inhibited by epigallocatechin gallate, and varies towards different flanking sequence with an order of 5'-CCGG-3' < 5'-CGCG-3' < 5'-CGCA-3'.

The dynamic process of adherence to a renal therapeutic regimen: perspectives of patients undergoing continuous ambulatory peritoneal dialysis

BACKGROUND

The nature of end-stage renal disease and the need for continuous ambulatory peritoneal dialysis require patients to manage various aspects of the disease, its symptoms and treatment. After attending a training programme, patients are expected to adhere to the renal therapeutic regimen and manage their disease with the knowledge and skills learned. While patients are the stakeholders of their health and related behaviour, their perceptions of adherence and how they adhere to their renal therapeutic regimen remains unexplored.

AIMS

To understand adherence from patients' perspectives and to describe changes in adherence to a therapeutic regimen among patients undergoing continuous ambulatory peritoneal dialysis.

DESIGN

This study used a mixed methods design with two phases - a survey in phase I and semi-structured interviews in phase II. This paper presents phase II of the study.

SETTINGS

The study was conducted at a renal unit of an acute hospital in Hong Kong.

PARTICIPANTS

Based on the phase I survey results, maximum variation sampling was employed to purposively recruit 36 participants of different genders (18 males, 18 females), ages (35-76 years), and lengths of dialysis experience (11-103 months) for the phase II interviews.

METHODS

Data were collected by tape-recorded semi-structured interviews. Content analysis was employed to analyse the transcribed data. Data collection and analysis were conducted simultaneously.

FINDINGS

Adherence was a dynamic process with three stages. At the stage of initial adherence, participants attempted to follow instructions but found that strict persistent adherence was impossible. After the first 2-6 months of dialysis, participants entered the stage of subsequent adherence, when they adopted selective adherence through experimenting, monitoring and making continuous adjustments. The stage of long-term adherence commenced after 3-5 years of dialysis, when participants were able to assimilate the modified therapeutic regimen into everyday life.

CONCLUSIONS

The process of adherence was dynamic as there were fluctuations at each stage of the participants' adherence. With reference to each stage identified, nursing interventions can be developed to help patients achieve smooth transition throughout all the stages.