Characteristics Of Retention Research Articles

Aerobic bacteria induced biomineralization: effects of nutrient and calcium content on the nanostructure and chemical composition of simulated cement mixture

During the past two decades, aerobic bacteria induced biomineralization has gained popularity for autonomous sealing of cracks in concrete structures due to its environmentally friendly characteristics of carbon retention. However, the mechanism of the biomineralization induced by aerobic bacteria for concrete crack sealing is still unclear due to the complex chemistry of cement matrix. Also, as the main nutrient for bacterial growth, the effect of yeast extract (YE) on biomineralization should be properly evaluated. For the first time, this study investigates the effects of YE and calcium content on the development of nanostructure and chemical composition of cement matrix during the biomineralization process induced by aerobic bacteria Bacillus cohnii. The effects of calcium content were realized by constructing a simulated cement mixture consisting of calcium hydroxide and synthesised C-S-H with different C/S ratios. The effects of YE content were evaluated by the addition of different amounts of YE into simulated cement mixture with different C/S ratios. Results suggest that 10g/l of YE can cause a high pH value of 10 and an unsuccessful growth of bacteria in simulated cement mixture with C/S ratios 0.6 and 0.8. Upon increasing the YE from 10 g/l to 20 g/l, the pH reduced from 10 to 9 and the bacteria was successfully grown. Higher amounts of bicarbonate ions can cause an enhanced decalcification of synthesised C-S-H rather than calcium hydroxide. The aerobic bacteria Bacillus cohnii showed superior performance on calcium absorption and calcite precipitation, being a promising way for practical concrete crack sealing.

Ecosystem services in the Yangtze River Basin and their trade-offs/synergies relationships in response to climate change

Abstract The Yangtze River Basin is an important ecological security barrier with significant economic status, but it is greatly affected by climate change. Therefore, we investigated the spatio-temporal evolution characteristics of annual ecosystem service (net primary production (NPP), water conservation and soil retention), their interrelationships and responses to climate change in the Yangtze River Basin from 2001 to 2020. The annual NPP, soil retention and water conservation were 511 gC m−2, 632 t and 272 mm, respectively and they all increased over 2001–2020 though this varied in both time and space. The capacities of soil retention and water conservation did not increase, and even gradually decreased for first 10 years (2001–2010), most likely due to the subsequent effects of the catastrophic flood of Yangtze River occurred in 1998. There are tradeoffs between NPP and soil retention/water conservation in the west Sichaun Province, which is different from the rest of the Yangtze River Basin where synergistic relationships dominate. Precipitation is the dominate climatic influencing factor on the ecosystem service trends found in the Yangtze River Basin. The concept of ecosystem services is being incorporated into decision-making and management, this study is critical to guide regional effective resource utilization, ecosystem management decisions and feasible policies.

LNMR analysis of the retention of different guar gum structure in sandstone: Based on a new characterization method

The adsorption and retention damage of guar gum to reservoirs are important factors affecting the effectiveness of hydraulic fracturing. Accurately understanding and evaluating the adsorption and retention of guar gum can better support the research of low-damage fracturing fluid. However, previous indoor evaluation methods have some limitations in studying the adsorption and retention characteristics of guar gum. The analysis object of low-field nuclear magnetic resonance (LNMR) is water rather than guar gum, which cannot achieve visualization of guar gum retention. In addition, Ordinary guar gum (GG), hydroxypropyl guar gum (HPG), and carboxymethyl guar gum (CMG) are commonly used in the hydraulic fracturing of sandstone gas reservoirs, but there are very few studies that focus on the differences in the adsorption and retention damage of the three guar gums from a microscopic perspective. In this study, a new characterization method for evaluating the retention of polymer in fracturing fluid based on the principles and properties of LNMR was proposed. This method can quantitatively evaluate the amount of guar gum adsorption retention and achieve a visual evaluation of the adsorption and retention of guar gum in cores. The aggregation characteristics of guar gum in porous media can be reflected. The dynamic retention process of GG, HPG, and CMG in sandstone cores was directly characterized through this method. The aggregation and entanglement characteristics of the three types of guar gum in sandstone were analyzed from the structure of guar gum. The experimental results show that the difference in molecular weight and modified groups of guar gum has an impact on its adsorption and retention. The molecular chain after the gel-breaking of GG was longer due to the large molecular weight. Long chains and intramolecular hydrogen bonds caused a larger curling degree of GG molecules. The entanglement degree of guar gum increased due to the introduction of non-ionic long-chain hydroxypropyl. The introduction of anionic carboxymethyl made CMG molecules more stretched due to electrostatic repulsion. The median particle size of the gel breaking liquid of GG was 10.65 μm, HPG was 8.8 μm, and CMG was 5.88 μm. A larger molecular particle size after guar gum gel breaking would aggravate the retention in sandstone porous media. After 150 min of displacement, the adsorption and retention amount of GG in the core was 4.59 mg/g, HPG was 4.17 mg/g, and CMG was 3.86 mg/g. The compactness of aggregates formed by guar gum in the core was HPG > GG > CMG. The gas flooding can relieve the adsorption and retention of guar gum. The higher the degree of entanglement of guar gum molecules, the more difficult to remove them from the core. The flowback degree of gas flooding of GG was 10.2%, HPG was 6.8%, and CMG was 21.9%. This research provides an experimental strategy for the microscopic evaluation of polymer adsorption and retention in rock porous media. The research results provide a deep understanding of the microscopic characteristics of guar gum adsorption and retention from the perspective of guar gum structure, which has some significance for guiding the optimization of fracturing fluid and the study of low-damage fracturing fluid.

Insight into the role of chitosan in rapid recovery and re-stabilization of disintegrated aerobic granular sludge

The disintegration and instability of aerobic granular sludge (AGS) systems during long-term operation pose significant challenges to its practical implementation, and rapid recovery strategies for disintegrated AGS are gaining more attention. In this study, the recovery and re-stabilization of disintegrated AGS was investigated by adding chitosan to a sequencing batch reactor and simultaneously adjusting the pH to slightly acidic condition. Within 7 days, chitosan addition under slight acidity led to the re-aggregation of disintegrated granules, increasing the average particle size from 166.4 μm to 485.9 μm. Notably, sludge volume indexes at 5 min (SVI5) and 30 min (SVI30) decreased remarkably from 404.6 mL/g and 215.1 mL/g (SVI30/SVI5 = 0.53) to 49.1 mL/g and 47.6 mL/g (SVI30/SVI5 = 0.97), respectively. Subsequent operation for 43 days successfully re-stabilized previous collapsed AGS system, resulting in an average particle size of 750.2 μm. These mature and re-stabilized granules exhibited characteristics of large particle size, excellent settleability, compact structure, and high biomass retention. Furthermore, chitosan facilitated the recovery of COD and nitrogen removal performances within 17–23 days of operation. It effectively facilitated the rapid aggregation of disintegrated granules by charge neutralization and bridging effects under a slightly acidic environment. Moreover, the precipitated chitosan acted as carriers, promoting the adhesion of microorganisms once pH control was discontinued. The results of batch tests and microbial community analysis confirmed that chitosan addition increased sludge retention time, enriching slow-growing microorganisms and enhancing the stability and pollutant removal efficiency of the AGS system.

Characteristics of sodium and water retention in rats with nephrotic syndrome induced by puromycin aminonucleoside

IntroductionNephrotic syndrome (NS) is characterized by renal sodium and water retention. The mechanisms are not fully elucidated.MethodsThe NS rat model was established by single intraperitoneal injection of 100 mg/kg puromycin aminonucleoside (PAN). The plasma electrolyte level and urinary sodium excretion were monitored dynamically. The changes of some sodium transporters, including epithelial Na+ channel (ENaC), Na+/H+ exchanger 3 (NHE3), Na+-K+-2Cl− cotransporter 2 (NKCC2) and Na+-Cl− cotransporter (NCC) in renal cortex at different time points and the level of peripheral circulation factors were detected.ResultsThe urinary sodium excretion of the model group increased significantly on the first day, then decreased compared with the control group, and there was no significant difference between the model group and the control group on the 12th day. The changes of peripheral circulation factors were not obvious. Some sodium transporters in renal cortex increased in varying degrees, while NKCC2 decreased significantly compared with the control group.ConclusionsThe occurrence of NS edema may not be related to the angiotensin system. The decrease of urinary sodium excretion is independent of the development of albuminuria. During the 18 days of observation, it can be divided into three stages: sodium retention, sodium compensation, and simple water retention. The mechanism is related to the increased expression of α-ENaC, γ-ENaC, NHE3 and NCC in a certain period of time, the compensatory decrease of NKCC2 expression and the continuous increase of aquaporin 2 (AQP2) expression.

Characteristics of water retention, nutrient storage, and biomass production across alpine grassland soils in the Qilian Mountains

Climate change has impaired the tightly-interlinked soil functions of grasslands, including water retention, biomass production, and carbon and nutrient storage. Limited knowledge of these functions' characteristics, influencing factors, and interrelationships hinders effective soil management. A field survey combined with regional data across alpine grasslands in the Qilian Mountains revealed that the soil water-holding capacity, measured by saturated water content, maximum water absorption, and field capacity, was strongest in alpine wet meadow (AWM), followed by alpine steppe (AS), alpine meadow (AM), and alpine meadow steppe (AMS), and lowest in alpine desert (AD). Soil bulk density and organic matter content (SOM) were key factors affecting water retention. The 0–50 cm storage of organic carbon and total nitrogen was the largest in AWM, about 2–3 times those in AD, with their concentrations significantly varied between soil layers, except for AWM. Conversely, total phosphorus and total potassium storage, with minimal concentration differences between layers, was highest in AD. Regression analysis showed that pH, soil water, and bulk density accounted for 24%–91% of organic carbon variance, and SOM explained over 98% of total nitrogen. Except for clay content, the effects of the mentioned factors on total potassium were mainly in surface layers (0–20 cm), whereas their effects on total phosphorus were smaller. Total biomass followed the pattern: AM>AWM > AMS > AS>AD. Aboveground biomass relied primarily on subsurface (20–50 cm) SOM and surface soil saturated water, while belowground biomass largely depended on subsurface total phosphorus and field capacity. Overall, soil functions exhibited gradient changes along the grassland sequence. Regional synergies suggest that soils in alpine meadows, the largest grassland type in the study area, can deliver multiple benefits concerning primary productivity and water‑carbon storage. This study can provide insight for assessing soil functions of grasslands in areas affected by permafrost and seasonal frost.

Deciphering the spatiotemporal trade-offs and synergies between ecosystem services and their socio-ecological drivers in the plain river network area

Understanding changes in ecosystem services (ESs) and quantitatively identifying the drivers that influence these changes are essential for achieving sustainable ecosystem development. In this study, multiple data sources and techniques, including meteorological data, land use/cover data, soil data, the InVEST model, and ArcGIS, were used to analyze the spatiotemporal variation characteristics of carbon storage, habitat quality, soil retention, water yield, and crop product supply in Xinghua City from 2000 to 2015. Additionally, we explored the causes of these changes and the interrelationships among these ESs. The results showed that: (1) During the study period, carbon storage and habitat quality declined, water yield fluctuated and increased, and soil retention had small interannual variations. The supply capacity of crop products first increased rapidly and then stabilized. (2) ESs were influenced by multiple drivers, with altitude having the strongest explanatory power for habitat quality and soil retention, and food production having the strongest explanatory power for crop product supply. (3) Relationships between different ESs were variable and changed over time. This study could enrich the understanding of spatial and temporal changes and drivers of ESs in the plain river network area, which has important implications for future land use planning and sustainable development of ESs.

Structure and Lithium Insertion in Oxides of Molybdenum

Oxides MoOx of molybdenum have a rich structural chemistry arising from the accommodation of oxygen deficiency as MoO3 is reduced, and varied redox behavior arising from the ability of Mo to take on several different oxidation states. We have reviewed MoO3, MoO2, and all the reduced Mo oxides with intermediate compositions for their performance as Li-ion battery electrode materials. These reduced oxides are perhaps the most structurally diverse in the field of energy storage materials, taking on structures ranging from ones with crystallographic shear to bronze-like structures and distorted rutile. Crystal structure can have a significant impact on the performance of battery materials, which makes the reduced Mo oxides a promising domain of study. Electrochemical studies of these oxides from as early as 1971 to as recently as 2022 have been compiled, and characteristics of capacity, capacity retention, and rate performance have been compared. We found that certain oxides indeed display promising and highly reversible capacities for Li+ storage. Typical redox voltages for Mo oxides lie in a regime that hinders maximizing energy density when they are paired with higher-voltage cathodes or lower-voltage anodes. The possibility of decreasing the redox voltage in the future will expand the promise of these materials, while offering an alternative to more critical elements such as Nb. Figure 1

Study on synthesis of environmentally-friendly polymer dust suppressant based on graft modification

In order to solve the dust problem caused by coal accumulation in the coal yard, a novel environmentally-friendly polymer dust suppressant was synthesized by graft copolymerization using sodium alginate (SA) and sodium carboxymethyl cellulose (CMC) as raw materials. Single factor experiments were carried out to determine the optimal synthesis conditions of SA-CMC, taking the viscosity and surface tension as the performance indicators. Under the optimal formulation, the viscosity was 80 mPa·s and the surface tension was 36.541 mN/m. Aiming to optimize the wetting property and resistance to evaporation of SA-CMC, the SA-CMC was combined with the water retention agent CMCS and the surfactant SDBS to obtain the composite dust suppressant (SA-CMC/CMCS). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to analyze the reaction process. Scanning electron microscope (SEM) was used to characterize the micro-structures of the cured layer on the coal dust surface after the dust suppressant spraying. The product performance test results showed that the dust suppressant had the characteristics of water absorption and water retention. The dust suppressant was sprayed on the surface of the coal dust to form a cured layer with high compressive strength, the bearing pressure of the cured layer was 43 N, and the dust suppression rate was as high as 99% under the strong wind (12 m/s) erosion conditions. Compared with water, the dust suppressant prepared in this paper has a better protection effect on coal dust and other forms of dust.

Characteristics of recurrent acute urinary retention in BPH patients in the United States: Retrospective analysis of US-based insurance claims database.

The objective of this study is to analyze characteristics of recurrent acute urinary retention (AUR) in patients with benign prostatic hyperplasia (BPH), utilizing a population based data set. Also, we sought to report on how AUR was treated, specifically regarding the need and length of catheterization and types of procedures utilized for mitigation. A retrospective observational cohort study was performed using Optum's deidentified Clinformatics® Data Mart Database. We compared twogroups, BPH patients with AUR (n = 180,737) and BPH patients without AUR (n = 1,139,760) from January 1, 2003 to December 31, 2017. Also, we analyzed the factors affecting the development of multiple episodes of AUR through age-adjusted multivariate analysis. In contrast to the 47.7% of patients who had a single AUR episode, 33.5% of AUR patients developed 3 or more subsequent episodes of retention. For age matched patients, the risks of additional episodes of retention increase significantly with older age, Caucasian race, diabetes, neurologic conditions, or low income. Overall, the rate of BPH surgery in AUR patients over the study period decreased and the most common procedure was transurethral resection of the prostate. Risk factors for multiple episodes of AUR included age (60 and older), Caucasian race, lower income socioeconomic status, diabetes, and neurological disorders. Patients with a high probability of developing recurrent episodes of AUR are recommended to receive preemptive BPH medication before such AUR occurrences. Also, more expeditious surgical treatment should be considered rather than temporary catheterization when AUR occurs.

Study on the safety characteristics of molten corium in-vessel retention of annular fuel core

In the process of reactor severe accidents, maintaining the integrity of reactor pressure vessel to achieve IVR (In-Vessel Retention) of molten corium plays an important role in accidents mitigation and suppression. The ERVC (External Reactor Vessel Cooling) is an important technology to realize IVR. As a new economical annular fuel, the increase of zirconium content and power density in the core may threaten the integrity of lower head under severe accidents. In this paper, the IVRASA (In-Vessel Retention Analysis code in Severe Accident) is used to analyze the heat transfer characteristics of lower head molten pool corresponding to annular fuel core. The components of two-layer and three-layer configurations of molten pool are determined based on the geometric structures of annular fuel and verified heavy metal layer model. In terms of the integrity of lower head, the power density of the annular fuel core can be increased to about 110%.

Study on the blood flow characteristics of venous needle retention with different super-hydrophobic surface structures

A venous retention needle, as an implanted device, is very likely to cause thrombosis. In view of the thrombosis phenomenon caused by retention needles, this paper compares the influence of different superhydrophobic surface retentions on blood flow. Compared with other superhydrophobic bulges, the fluid velocity of the four-prism bulge is the highest (0.08 m/s), and the vorticity and shear force of the hemispherical bulge are higher. A large number of vortices can inhibit thrombosis better. The tire vortices generated in the superhydrophobic convex grooves are important vortices to inhibit thrombosis. The enhancement and development of the tire vortex weakens the resistance near the wall of the needle and reduces the probability of platelet aggregation. The superhydrophobic surface structure studied in this paper can not only provide guidance for the design of venous retention needles with better performance but also provide corresponding technical support for the development of human implantation devices.Graphical

Structure and lithium insertion in oxides of molybdenum

Oxides of molybdenum, MoOx, have a rich structural chemistry arising from the accommodation of oxygen deficiency as MoO3 is reduced and varied redox behavior arising from the ability of Mo to take on several different oxidation states. We review MoO3, MoO2, and all the reduced Mo oxides with intermediate compositions for their performance as Li-ion battery electrode materials. These reduced oxides are perhaps the most structurally diverse in the field of energy storage materials, taking on structures ranging from ones with crystallographic shear to bronze-like structures and distorted rutile. The crystal structure can have a significant impact on the performance of battery materials, which makes the reduced Mo oxides a promising domain of study. Electrochemical studies of these oxides from as early as 1971 to as recently as 2022 are compiled, and characteristics of capacity, capacity retention, and rate performance are compared. We find that certain oxides indeed display promising and highly reversible capacities for Li+ storage. Typical redox voltages for Mo oxides lie in a regime that hinders maximizing energy density when they are paired with higher-voltage cathodes or lower-voltage anodes. The possibility of decreasing the redox voltage in the future will expand the promise of these materials while offering an alternative to more critical elements such as Nb.

The radiological prognostic factors of transcatheter arterial chemoembolization to hepatocellular carcinoma

Transcatheter arterial chemoembolization (TACE) is the recommended treatment modality for intermediate stage hepatocellular carcinoma (HCC). The aim of this study was to determine the HCC radiological characteristics associated with prognosis of patients with intermediate stage HCC receiving TACE. Patients with HCC BCLC stage B from January 2005 to December 2009 were collected. According to mRECIST criteria, patients with complete response and partial response were assigned to the objective response (OR) group, while those with stable disease and progressive disease were assigned to the nonobjective response (non-OR) group. Among a total of 128 enrolled patients, there were 66 (51.6%) and 62 (48.4%) patients in the OR group and non-OR group, respectively. The clinical parameters in the two groups were similar, although HCC size was smaller in the OR group. Logistic analysis found combined radiological characteristics including complete lipiodol retention, tumor feeding artery blockage, and no residual tumor blush were significant correlated with achievement of OR (odds ratio 2.46, 95% CI 1.08–5.61, P = .032). However, no radiological characteristics had significant strength to predict overall survival. Patients with OR after TACE had significantly longer survival time than those with non-OR. Combined characteristics of complete lipiodol retention, tumor feeding artery blockage, and no residual tumor blush had a positive impact on OR in TACE. In patients receiving TACE, those who achieved OR had a better overall survival.

Oral Glucose-Responsive Nanocarrier System for Management of Diabetes

Background: The regulation of postprandial blood glucose concentration in a diabetic person is a toilsome task by the conventional approaches. The continuous monitoring and subcutaneous injection of insulin are always imperative for diabetes management. To overcome the hurdle associated with the conventional system, a glucose-responsive nanoparticle (NP)-based approach was developed for oral insulin administration. The objective of the work is the formulation and characterization of a nanocarrier-based bio-responsive, self-regulated oral insulin drug delivery system. Methods: The mannose ligand-conjugated NPs were prepared by the inotropic gelation method in which insulin and glucose oxidase enclosed alginate nanocarrier cross-linked by tripolyphosphate. The prepared NPs were filled into the enteric-coated capsule and their release profile was determined at different pH and glucose concentrations. NPs were characterized by size distribution, % drug entrapment, enzyme activity, and in vivo and in vitro drug release studies. Results: The average size, surface potential, % drug entrapment of optimized NPs were 245.52 ± 3.37 nm, 22.12 ± 2.13, and 76.15±1.3%, respectively. The release of insulin from optimized NPs (GOx-ALG-MCNPs) (98.56±0.06%) occurs only at higher sugar concentrations (? 400 mg/dL) and prevents the release at low sugar concentrations (< 100 mg/dL). The enteric capsule shell protected the formulation to the gastric environment upon oral administration and directed them into the intestine. Mucoadhesion characteristics of NPs prolonged intestinal retention to make them available for cellular uptake. Glucose sensitivity and glucose-dependent effect on different pH environments study revealed that NPs released the drug only at higher concentrations of sugar solution while inhibiting the release at normal and lower sugar concentrations. Besides, compared to other prepared formulations, the GOx-ALG-MCNPs displayed controlled insulin release in response to glucose concentration. Conclusions: An important finding of GOx-ALG-MCNPs is auto-regulating, glucose-responsive behavior imparting a significantly controlled lowering of blood glucose in an animal model. The findings reveal that the developed glucose-responsive NPs may prove to be a potential strategy for oral insulin delivery. J Endocrinol Metab. 2022;12(4-5):146-160 doi: https://doi.org/10.14740/jem747

Should Anthropic Ridges Framed as Foredunes Be Considered Real Dunes?

Aeolian features framed as foredunes worldwide, whose classification faces challenges to separate wave-formed from aeolian ridges, are relevant to the context of anthropic control. An example of this kind of morphology, previously classified as foredunes, is arranged along Brazil’s northeastern coast, and the pertinence of its classification as such or even as truly developed dunes was examined. To contribute to the debate on this issue, detailed geomorphological mapping was carried out through UAV and LIDAR surveys, in addition to the multitemporal study of satellite images and aerial photographs. Ground penetration radar sections, trenches, and particle size analysis were also conducted. Although the obliquity of wind direction to the coastline, this study’s main bedform of focus shows coast-parallel positioning conditioned by the exogenous vegetation previously inserted about 70 m from the high tide line. This morphology showed practically no migration for over 15 years; however, the wind breaks through the vegetation barrier and develops depositional lobes and V-shaped low crests protruding into the mainland. GPR sections reveal cross-strata sets with a high dip angle in only two aeolian sequences, one preceding exogenous vegetation introduction and the other in a contemporary layer, amidst the dominance of horizontal to sub-horizontal strata. The sediments are characteristically aeolian, with cross-strata and morphology resembling incipient protodunes and a few stretches at the lee slope highlighting characteristics of retention or precipitation dunes. There was little similarity to the foredunes compared to the other occurrences along the equatorial northeast coast; there was also an inconsistency in the correlation between the cross-strata and the morphological stage. In addition, the disconnection between the aeolian dynamics and morphogenetic process also differentiates it from regional foredunes. This morphology, therefore, presents aspects that are not characteristic of the classification of foredunes or the naturally formed dunes in the region and thus demands a classification to emphasize the anthropogenic character.

Retaining an Upper Bound for the Capillary Retention of Two-Phase Flow in Porous Media

At the sub-meter scale, capillary retention occurs when two immiscible phases flow across two heterogeneous media. It happens in the upstream medium, and the phase retained depends on the heterogeneity order and the system wettability. This phenomenon has a major impact on the oil recovery and hence requires comprehension. The analysis of the spatial variation in the phase saturation along the flowing domain is well established. However, the literature lacks the general characteristics of capillary retention caused by such variation at various flowing conditions. The continuum model for the flow of two immiscible phases in porous media at steady-state conditions is examined. The analysis is limited to the medium with a single discontinuity in rock properties. In this examination, the characteristics of the capillary retention upstream of the discontinuity are the primary consideration. Three retention regions related to the flow regime are identified: two plateaus and a transition zone occurring, in general, at intermediate capillary number. The width and location of the transition depend on the fractional flow. The crucial finding is related to the identification of an upper bound for the capillary retention and its dependency on the capillary variable ratio and the form of the Leverett J-curve. Two J-models are investigated, and it is shown that, for a given capillary variable ratio, the upper bound depends on the level of flatness of the J-curve at intermediate saturations. Potential implications of the current analysis to reservoir characterization are also discussed.Article HighlightsThree retention regions related to the ow regime are identified: two plateaus and a transition zone occurring at intermediate capillary numbers. The width and position of the transition depend on the fractional flow.An upper bound for the capillary retention is derived and its dependency on the heterogeneity ratio and the form of the Leverett-J curve is discussed..Potential implication to reservoir characterization: In the case of steeper Leverett-J curves with low to moderate random heterogeneity ratios, the upper bound is minimal regardless of the various lithologies and their congurations. In such conditions, the upper bound can be used to assert the insignicance of the eld-scale capillary retention.

Bacterial biofilm microenvironment responsive copper-doped zinc peroxide nanocomposites for enhancing chemodynamic therapy

Dental plaque, a kind of natural biofilm, has attracted much attention because of its role in caries and periodontal disease. The pathogenicity of the dominant bacterial species of S. mutans is based on the formation of extracellular polysaccharides (EPS) and its survival in acidic environments. In addition, the formed plaque biofilm has the characteristics of water insolubility, retention, and low membrane permeability. This is why there are no effective antibiotics orother ways to treat dental caries. Chemodynamic therapy (CDT) is an ideal therapeutic modality with biofilm microenvironment as stimulus. In this paper, a unique nanocomposite, ZnO2-Cu@RB NPs, has been prepared which is composed of copper-doped zinc peroxide nanoparticles (ZnO2-Cu NPs) and antibacterial agent Rose Bengal (RB). It can quickly (<10 min) and efficiently kill S. mutans (greater than 8.0 log10 CFU mL−1) in acidic biofilm via the in situ enhanced CDT, and significantly reduce the demineralization of apatite. ZnO2-Cu@RB NPs can also weaken the acid production of S. mutans and inhibit the formation of EPS. More significantly, excellent therapeutic efficacy against S. mutans in the rat model was observed. Our findings reveal the great potential of metal peroxide nanoparticles as a new strategy for combating biofilm-related diseases.

Teeth Eruption Disorders: A Critical Review.

Dental eruption refers to the vertical displacement of a tooth from its initial non-functional towards its functional position. Tooth eruption disorders may be expressed in various clinical conditions, which may be grouped as “primary retention” and “secondary retention”. The purpose of this article is to review the literature and the clinical parameters of the various conditions related to tooth eruption disorders. Materials and Methods: The search strategy of this critical review included keywords in combination with MeSH terms in Medline, Scopus, and Cochrane Library until February 2022 and only in English. Results: “Primary Failure of Eruption” (PFE) occurs during the eruption process and includes clinical characteristics of both primary and secondary retention, which make diagnosis difficult. PFE is distinguished by Types I and II. In Type I, the defect in the eruption process occurs in all the relative teeth at the same time, whilst in Type II, the clinical expressions vary in multiple quadrants of the mouth, and the second molars erupt more. The variability of the PFE’s clinical spectrum seems to be connected to a genetic origin. The differential diagnosis among single ankylosis, secondary retention, and PFE is based on the occlusal relationship between the upper and the lower teeth distally, most commonly the first molar, which has not yet fully erupted. The treatment approach depends on many factors and combines surgical and orthodontic techniques.

Abstract 231: Patient, Operator, And Procedural Characteristics Of Guidewire Retention As A Complication Of Vascular Catheter Insertion

Introduction: Guidewire retention after intravascular catheter insertion is considered a “never event.” Prior reports attribute this complication to various characteristics including uncooperative patients, operator inexperience, off-hour or emergent insertion, and underutilization of ultrasound guidance. In this descriptive analysis of consecutive events, we assessed the frequency of patient, operator, and procedural factors in guidewire retention. Methods: All consecutive incidents of guidewire retention across 10 hospitals within the Cleveland Clinic Health System in Ohio from August 2007 to October 2015 were prospectively identified and retrospectively analyzed. Data were manually obtained from the electronic medical records and reviewed for potential contributing factors for guidewire retention including patient, operator, and procedural characteristics. Results: A total of 24 guidewire retention events were identified. Overall, the median age was 74 years, 58% were males, and the median body mass index was 26.5 kg/m 2 . A total of 12 (50%) individuals were sedated during the procedure. Most incidents (10 [42%]) occurred in internal jugular venous access sites. The majority of cases (13 [54%]) were performed or supervised by an attending. Among all cases, 3 (12%) were performed by first-year trainees, 7 (29%) by residents, 3 (12%) by fellows, and 4 (17%) by certified nurse practitioners. Overall, 16 (67%) events occurred during regular working hours (8AM - 5PM). In total, 22 (92%) guidewires were inserted non-emergently, with 2 (8%) during a cardiac arrest. Ultrasound guidance was used in all but 1 case. Conclusion: Guidewire retention can occur even in the presence of optimal patient, operator, and procedural circumstances, highlighting the need for constant awareness of this risk. Efforts to eliminate this important complication will require attention to issues surrounding the technical performance of the procedure.