Temperature, pressure, and duration impacts on the optimal stiffening of carbonates aged in diammonium phosphate solution.

Diammonium phosphate (DAP) has been proven effective in improving the stiffness of weak or acid-damaged carbonates, thereby preserving hydraulic fracture conductivity. The reaction between DAP and calcite in chalk formations primarily produces hydroxyapatite (HAP), which is stiffer than calcite. However, the optimal reaction outcomes vary greatly with factors such as DAP concentration and reaction conditions. This study investigated the DAP-calcite reaction duration, pressure, and temperature effects on the stiffness magnitude of soft Austin chalk. Also, the catalyst effect and depth of HAP formation were examined. The study involved the assessment of stiffness non-destructively (impulse hammering), mineralogy (XRD, SEM), and elemental composition (XRF). The study tested 15 different DAP-chalk reaction variations, where the pressure, temperature, aging time and catalyst addition were modified in each case. The samples' elastic stiffness distributions were then collected and compared to the pre-reaction ones. The results showed that the elastic stiffness increased in all treated samples, with an 181% maximum increase achieved after 72 h at 6.9 MPa and 75 °C. However, the pressure effect was minor compared to the temperature. The SEM images revealed different HAP morphology corresponding to different treatment conditions. Although the treated samples showed an increased intensity of phosphorus throughout the entire sample, the near-surface zone (4-6 mm) was the most affected, as inferred from the XRF elemental analysis. The study's findings can help optimize hydraulic fracturing operations in weak carbonate reservoirs, improving production rates and overall well performance.

Neuromodulatory effect of vardenafil on aluminium chloride/D-galactose induced Alzheimer's disease in rats: emphasis on amyloid-beta, p-tau, PI3K/Akt/p53 pathway, endoplasmic reticulum stress, and cellular senescence.

Dysregulation of protein homeostasis, proteostasis, is a distinctive hallmark of many neurodegenerative disorders and aging. Deleteriously, the accumulation of aberrant proteins in Alzheimer's disease (AD) is accompanied with a marked collapse in proteostasis network. The current study explored the potential therapeutic effect of vardenafil (VAR), a phosphodiesterase-5 inhibitor, in AlCl3/D-galactose (D-gal)-induced AD in rats and its possible underlying mechanisms. The impact of VAR treatment on neurobehavioral function, hippocampal tissue architecture, and the activity of the cholinergic system main enzymes were assessed utilizing VAR at doses of 0.3 mg/kg and 1 mg/kg. Additionally, the expression level of amyloid-beta and phosphorylated tau proteins in the hippocampus were figured out. Accordingly, VAR higher dose was selected to contemplate the possible underlying mechanisms. Intriguingly, VAR elevated the cyclic guanosine monophosphate level in the hippocampus and averted the repressed proteasome activity by AlCl3/D-gal; hence, VAR might alleviate the burden of toxic protein aggregates in AD. In addition, a substantial reduction in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with VAR treatment. Notably, VAR counteracted the AlCl3/D-gal-induced depletion of nuclear factor erythroid 2-related factor 2 level. Moreover, the anti-senescence activity of VAR was demonstrated via its ability to restore the balance of the redox circuit. The modulation of phosphatidylinositol-3-kinase/protein kinase B/p53 pathway and the reduction of nuclear factor kappa B level, the key regulator of senescence-associated secretory phenotype mediators release, with VAR treatment were also elucidated. Altogether, these findings insinuate the possible therapeutic benefits of VAR in AD management.

Erratum to "Effect of Eucalyptus globulus oil and Ricinus communis methanolic extract as potential natural molluscicides on the reproductive biology and some antioxidant enzymes of the land snail, Theba pisana" [Heliyon 8 (12) (December 2022) Article e12405].

[This corrects the article DOI: 10.1016/j.heliyon.2022.e12405.].

Roflumilast escalates α-synuclein aggregate degradation in rotenone-induced Parkinson's disease in rats: Modulation of the ubiquitin-proteasome system and endoplasmic reticulum stress.

Perturbation of the protein homeostasis circuit is one of the principal attributes associated with many neurodegenerative disorders, such as Parkinson's disease (PD). This study aimed to explore the neuroprotective effect of roflumilast (ROF), a phosphodiesterase-4 inhibitor, in a rotenone-induced rat model of PD and investigate the potential underlying mechanisms. Interestingly, ROF (1 mg/kg, p.o.) attenuated motor impairment, prevented brain lesions, and rescued the dopaminergic neurons in rotenone-treated rats. Furthermore, it reduced misfolded α-synuclein burden. ROF also promoted the midbrain cyclic adenosine monophosphate level, which subsequently enhanced the 26S proteasome activity and the expression of the 20S proteasome. ROF counteracted rotenone-induced endoplasmic reticulum stress, which was demonstrated by its impact on activating transcription factor 6, glucose-regulated protein 78, and C/EBP homologous protein levels. Moreover, ROF averted rotenone-induced oxidative stress, as evidenced by its effects on the levels of nuclear factor erythroid 2-related factor 2, heme oxygenase-1, reduced glutathione, and lipid peroxides with a significant anti-apoptotic activity. Collectively, this study implies repurposing of ROF as a novel neuroprotective drug owning to its ability to restore normal protein homeostasis.

The relationship between ankle dorsiflexion range of motion, frontal plane projection angle, and patellofemoral pain syndrome.

BACKGROUND: Ankle range of motion abnormalities have been often linked with alteration in knee kinematics leading to the development of patellofemoral pain syndrome (PFPS). Literature exploring the relationship between ankle dorsiflexion range of motion (DF ROM) and knee kinematics during functional tasks is scanty. This study aims to assess the relation between ankle DF ROM and frontal plane projection angle (FPPA), one of the knee kinematic variables, in individuals with and without PFPS during a step-down test. METHODS: This is a case-control study in which seventy PFPS patients and other 70 asymptomatic control subjects had their ankle DF ROM measured using an inclinometer with the knee flexed and extended. Their FPPA angles were measured using Kinovea software while doing the step-down test. RESULTS: When the two groups were compared, ankle DF ROM measured with the knee flexed was higher in the control group (33.15 ± 4.96) than in the PFPS group (30.20 ± 6.93) (p = 0.03). In both the PFPS group and the control group, the correlation between FPPA and ankle DF ROM with the knee flexed was statistically insignificant (p = 0.075 and 0.323 respectively). CONCLUSION: Decreased ankle DF ROM can be one of the contributing factors to the development of PFPS in the context of greater dynamic knee valgus.

Clinical outcomes in stump-preserving versus stump-sacrificing anterior cruciate ligament reconstruction; a randomized controlled study.

BACKGROUND: Anterior Cruciate ligament (ACL) reconstruction (ACLR) aims to restore the anatomy and function of the knee. Although stump preservation during ACLR could be technically challenging, it may improve the revascularization and proprioceptive function of the graft. In this study, we aimed to compare the functional outcome after ACLR with and without stump preservation. METHODS: One hundred and twenty patients with acutely torn ACL and with intact tibial stump were included in this study. Half of them (60 cases) underwent ACLR with stump preservation. The other half (60 cases) had ACLR after total resection of the tibial stump. One hundred and nine out of 120 cases completed their 2 year-follow-up period. All patients were assessed by Tegner activity, Lysholm, and objective International Knee Documentation Committee (IKDC) scores. The side-to-side difference regarding stability was assessed by KT-1000 instrumented Lachman and proprioceptive function was measured by Passive angle reproduction test. RESULTS: There was no statistically significant difference between both groups regarding Tegner activity, Lysholm, and IKDC scores. Knee stability measured by KT-1000 and complication rate also showed no significant difference. But there was a significant difference in proprioception favoring stump preservation. On the other hand, the operative time was significantly shorter with stump resection. There was no significant difference in the complications rate between both groups and there were no cases with stiffness in either group. CONCLUSION: Stump preservation ACLR is a safe technique that yields equivalent functional outcomes to standard ACLR. However; it provides better proprioception. It is more technically challenging, but in experienced hands; it is easily reproducible. TRIAL REGISTRATION: Registration number: NCT05364398 . 06/05/2022.

Volar locking plate fixation for distal radius fractures: did variable-angle plates make difference?

PURPOSE: Two different locking plate designs are now being used for volar plating of the distal radius fractures based on the freedom of screw direction; the fixed-angle, and the variable-angle (polyaxial) plates. We investigated the clinical and radiographic outcomes of both designs. METHODS: We reviewed 96 patients with 113 unstable distal radius fractures that were operated on with volar locking plates. The patients' mean age was 41 years. Fixed-angle volar locking plates were utilized in 65 fractures and variable-angle volar locking plates in 48 fractures through modified Henry approach or extended carpal tunnel approach. Full clinical and radiographic evaluation was done for all patients with a mean follow-up of 14 months. RESULTS: All patients had acceptable clinical and radiographic parameters. The overall functional results (Mayo score, Quick Disability of Arm, Shoulder, and Hand (Q-DASH) score, Range of motion (ROM), and grip strength) were in favor of the variable-angle plate. The radiographic parameters were better with the variable-angle group. The variable-angle group recorded less operative time but more mean image intensifier exposure time. There were two cases of flexor tendon rupture with the fixed-angle group. Fixation with the fixed-angle system needed K-wire augmentation more than the variable-angle group. There was a positive correlation between hand dominance and the final score. CONCLUSION: Distal radius volar locking plates yield satisfactory results comparable among different designs. In our series, the variable-angle system showed slightly better function and radiographic outcomes. Supplementary K-wires were needed more frequently with the fixed-angle system.

Finite element analysis modeling of plates versus intramedullary nails in closed comminuted midshaft tibial fractures.

BACKGROUND: Tibial shaft fractures are usually treated by interlocking nails or plates. The ideal implant choice depends on many variables. AIM: To assess the mechanical behavior of interlocking nails and plates in the treatment of closed comminuted midshaft fractures of the tibia using finite element analysis. MATERIAL AND METHODS: This is a prospective study of 50 patients with a mean age of 28.4 years with closed comminuted fractures of the midshaft of the tibia. Data evaluation was done by Finite element analysis (FEA). Fixation was revised in two cases. RESULTS: After load application, there were significant differences in both bending (P = 0.041) and strain percent (P = 0.017), reflecting that interlocking nails were superior to plates. There were also significant differences between titanium and stainless-steel materials in bending (p = 0.041) and strain percent (p = 0.017) after applying load, indicating that titanium was superior to stainless steel. CONCLUSION: Interlocking nails are superior to plates in treating midshaft tibial fractures. The use of blocking screws may be needed in interlocking nails depending on the pattern and extension of the fracture.

Lateral malleolar fractures Weber Type A and B: does percutaneous intramedullary screw confer a solid alternative to the traditional neutralization plate?

PURPOSE: To compare the clinical results, complication rates, and radiographic outcome between both methods of fixation of lateral malleolar fractures: lateral neutralization plates and intramedullary fully threaded screws. PATIENTS AND METHODS: This prospective case series study involved 73 patients with fractured lateral malleolus of type A, B according to Weber classification, to whom internal fixation was performed by either lateral plate and screws construct (Group A) or intramedullary screw (Group B). All patients were followed up for 12 months at least, with an average follow-up time of 12.7 months. RESULTS: There was no significant difference in the functional outcome score between both groups. The intramedullary screw group had a significantly shorter operative time and time to full union (P<0.001 and =0.006 respectively). There was a relatively higher accuracy of reduction with the plate fixation group, but it was statistically insignificant. There was a relatively fewer complication rate with the use of intramedullary screw fixation compared to plate fixation. CONCLUSION: The use of intramedullary fixation is a good alternative for plate fixation in low fibular fractures (Weber A and B). Although plate fixation provides an optimal anatomic reconstruction of the fractures, intramedullary fixation may have a lower risk of complications.

Effect of Eucalyptus globulus oil and Ricinus communis methanolic extract as potential natural molluscicides on the reproductive biology and some antioxidant enzymes of the land snail, Theba pisana.

This study was conducted to investigate the effects of Eucalyptus globulus oil and methanolic extract of Ricinus communis seeds on the reproductive biology of the land snail Theba pisana. For this purpose, the snails were exposed to different concentrations of these plant extracts for six weeks. Rates of oviposition, hatching percentages, reproductive hormones and the histological structures of the hermaphrodite gland were estimated. Antioxidant enzymes were also estimated. The obtained results revealed that all tested concentrations of both tested natural products exerted hazardous effects on exposed snails. The mean egg number/snail treated with 2% E. globulus and R. communis were significantly decreased to 22 and 14 eggs respectively compared to 79 eggs for control. The hatching rates were dramatically decreased with increasing concentrations of both products. 2% of R. communis extract caused highly significant decrease in the activities of CAT, SOD, GST and MDA antioxidant enzymes while the same concentration of Eucalyptus oil resulted in elevations of CAT and SOD activities and significantly decreased GST and MDA activities. Levels of reproductive hormones were greatly disrupted and the histological structures of hermaphrodite acini as well as various developmental stages of spermatogenesis and oogenesis of treated snails were strictly spoiled.

Machine Learning-Based Propped Fracture Conductivity Correlations of Several Shale Formations.

In hydraulic fracturing operations, small rounded particles called proppants are mixed and injected with fracture fluids into the targeted formation. The proppant particles hold the fracture open against formation closure stresses, providing a conduit for the reservoir fluid flow. The fracture's capacity to transport fluids is called fracture conductivity and is the product of proppant permeability and fracture width. Prediction of the propped fracture conductivity is essential for fracture design optimization. Several theoretical and few empirical models have been developed in the literature to estimate fracture conductivity, but these models either suffer from complexity, making them impractical, or accuracy due to data limitations. In this research, and for the first time, a machine learning approach was used to generate simple and accurate propped fracture conductivity correlations in unconventional gas shale formations. Around 350 consistent data points were collected from experiments on several important shale formations, namely, Marcellus, Barnett, Fayetteville, and Eagle Ford. Several machine learning models were utilized in this research, such as artificial neural network (ANN), fuzzy logic, and functional network. The ANN model provided the highest accuracy in fracture conductivity estimation with R 2 of 0.89 and 0.93 for training and testing data sets, respectively. We observed that a higher accuracy could be achieved by creating a correlation specific for each shale formation individually. Easily obtained input parameters were used to predict the fracture conductivity, namely, fracture orientation, closure stress, proppant mesh size, proppant load, static Young's modulus, static Poisson's ratio, and brittleness index. Exploratory data analysis showed that the features above are important where the closure stress is the most significant.

Data-Driven Acid Fracture Conductivity Correlations Honoring Different Mineralogy and Etching Patterns.

Acid-fracturing operations are mainly applied in tight carbonate formations to create a highly conductive path. Estimating the conductivity of a hydraulic fracture is essential for predicting the fractured well productivity. Several models were developed previously to estimate the conductivity of acid-fractured rocks. In this research, machine learning methods were applied to 560 acid fracture experimental datapoints to develop several conductivity correlations that honor the rock types and etching patterns. Developing one universal correlation often results in significant error. To develop conductivity correlations, various data preprocessing methods were applied to remove the outliers and failed experiments. Features that did not contribute to precise predictions were removed through regularization. A machine learning classifier was built to predict the etching pattern based on the input data. We generated a multivariate linear regression model and compared it with other models generated through ridge regression. In addition to that, artificial neural network-based model was proposed to predict the fracture conductivity of several carbonate rocks such as dolomite, chalk, and limestone. The performance of the developed models was assessed using well-known metrics such as precision, accuracy, mean squared error, recall, and correlation coefficients. Cross-validation was also employed to assure accuracy and avoid overfitting. The classifier accuracy was 93%, while the regression model resulted in a relatively high correlation coefficient.

Distribution, fate and histopathological effects of ethion insecticide on selected organs of the crayfish, Procambarus clarkii.

This study aims to investigate the fate and histopathological effects of ethion on selected organs of the crayfish, Procamabrus clarkii. Crayfish were exposed to 1 mg l(-1) (14)C-ethion and the concentrations of ethion and its possible degradation products were measured in water and different organs of the crayfish over both the exposure and recovery periods. Chromatographic analysis revealed that ethion was degraded into ethion monooxon, ethion dioxon, O,O-diethyl phosphorothioate, O-ethyl phosphorothioate and one unknown compound. At the end of exposure period, ethion was accumulated in different organs of the crayfish especially in the hepatopancreas and gills. Following the transfer of crayfish to clean water for seven days, the concentration of insecticide residues were decreased in both the hepatopancreas and gills suggesting that these organs play an important role in elimination of ethion. On the other hand, the exposure of the crayfish to » 96 h-LC(50) (0.36 mg l(-1)) of ethion caused extensive ultrastructural alterations to both hepatopancreas and gill epithelial cells. In the hepatopancreas, the most notable pathological features included vacuolation, degradation and distinct cell lysis. In the gill epithelium, the histopathological alterations included infiltration of hemocytes, cytoplasmic vacuolation and a decrease in the number of basal plasma membrane infoldings.

Tissue distribution and subcellular localization of trace metals in the pond snail Lymnaea stagnalis with special reference to the role of lysosomal granules in metal sequestration.

The present study was undertaken to elucidate the cellular mechanisms, which govern metal sequestration and detoxification in gastropods. For this purpose the pond snail, Lymnaea stagnalis was exposed to environmentally relevant concentrations of three species of metals (Al, Zn and Cd) for 30 days and the localization and fate of these metals were followed in different tissues of the snails. The measurement of relative distribution of metals between tissues revealed that the digestive gland and kidney account for most of the accumulated metals. Al and Cd (non-essential metals) were redistributed to the digestive gland, possibly because of the presence of specific binding entities in the digestive glands of the herein species. This study focuses on the role of intracellular metal-containing granules on metal sequestration. Three main types of granules were identified in the digestive gland cells namely small, green and yellow granules. The morphological examination and the progressive accumulation of elements within these granules revealed that they are developmental stages with the yellow granule being the mature one. The total number of these granules was found to be significantly increased upon exposure of the snails to Al only. This increase may be a response to the large amount of Al that is accumulated through feeding route of this grazing snail. X-ray microanalysis (XRMA) revealed that metals were localized in all three types of digestive gland granules. The increased amount of ligands (P and S) in the granules may give evidence for their role in metal sequestration. Levels of Al and P were positively correlated in the digestive gland granules. It is possible that aluminium is bound to phosphorus to render it insoluble and so to both immobilize it within the lysosome and to be excreted in a highly insoluble form. On the other hand, both Zn and Cd induced marked upregulation of S in mature (yellow) granules by 26- and 11-folds, respectively. The lysosomal codeposition of S and either Cd or Zn in the lysosomal granules in addition to the increase in RER cisternae may indicate that the exposure to these metals could induce metallothionein synthesis in the cells. The microscopical examinations in the present study revealed that metal detoxification from the digestive gland cells may occur via faeces or via basal exocytosis towards hemocytes dispersed by the connective tissue in the visceral mass. In the kidney, one type of granules, the excretory concretions, was identified in the nephrocytes. The significant increase in the number of these concretions in the snail L. stagnalis upon exposure to metals may give further evidence for their role in metal excretion.

Effect of orthosilicic acid on the accumulation of trace metals by the pond snail Lymnaea stagnalis.

Silicon (Si) has a marked affinity for aluminium (Al(III)), but not other trace metals such as cadmium (Cd(II)) and zinc (Zn(II)). Exogenous orthosilicic acid (Si(OH)(4)) ameliorates the toxicity of Al(III) to the pond snail Lymnaea stagnalis, but its mechanism of action is unclear. Here, studies were conducted to ascertain whether interaction between orthosilicic acid and Al(III) occurs in the water column to prevent Al(III) uptake, or in the tissues to reduce the toxicity of accumulated metal. Silicon did not reduce the accumulation of Al(III) by the digestive gland (the main "sink" for trace metals in L. stagnalis) following exposure of the snail for 30 days to 500 microg l(-1) added Al(III) and 13-fold molar excess of orthosilicic acid. However, Si concentrations correlated well with Al(III) levels in the digestive gland (R(2)=0.77), giving a ratio of 2.5:1 (Al(III):Si). Exposure to Zn(II) or Cd(II) and 13-fold molar excess of orthosilicic acid did not prevent uptake of these metals, or result in a correlation between metal and Si concentrations of the snail digestive gland. These data show that aquated orthosilicic acid does not prevent Al(III) accumulation by L. stagnalis. However, following exposure, the ratio of Al(III) to Si in the digestive gland is suggestive of the early formation of hydroxyaluminosilicates, probably proto-imogolites (2-3:1 Al(III):Si). Whether hydroxyaluminates are formed ex vivo in the water column and taken up by snails into the digestive gland, or formed in situ within the digestive gland remains to be established. Either way, orthosilicic acid clearly prevents the in vivo toxicity of Al(III) rather than reducing its uptake. Silicon appears to have an important role in the handling Al(III) by the pond snail which may also have wider relevance in understanding the role of Si in ameliorating Al(III) toxicity.

Aluminum-dependent regulation of intracellular silicon in the aquatic invertebrate Lymnaea stagnalis.

Silicon is essential for some plants, diatoms, and sponges but, in higher animals, its endogenous regulation has not been demonstrated. Silicate ions may be natural ligands for aluminum and here we show that, in the freshwater snail (Lymnaea stagnalis), intracellular silicon seems specifically up-regulated in response to sublethal aluminum exposure. X-ray microanalysis showed that exposure of snails to low levels of aluminum led to its accumulation in lysosomal granules, accompanied by marked up-regulation of silicon. Increased lysosomal levels of silicon were a specific response to aluminum because cadmium and zinc had no such effect. Furthermore, intra-lysosomal sulfur from metallothionein and other sulfur-containing ligands was increased after exposure to cadmium and zinc but not aluminum. To ensure that these findings indicated a specific in vivo response, and not ex vivo formation of hydroxy-aluminosilicates (HAS) from added aluminum (555 microg/liter) and water-borne silicon (43 microg/liter), two further studies were undertaken. In a ligand competition assay the lability of aluminum (527 microg/liter) was completely unaffected by the presence of silicon (46 microg/liter), suggesting the absence of HAS. In addition, exogenous silicon (6.5 mg/liter), added to the water column to promote formation of HAS, caused a decrease in lysosomal aluminum accumulation, showing that uptake of HAS would not explain the loading of aluminum into lysosomal granules. These findings, and arguments on the stability, lability, and kinetics of aluminum-silicate interactions, suggest that a silicon-specific mechanism exists for the in vivo detoxification of aluminum, which provides regulatory evidence of silicon in a multicellular organism.