Transition Zone Research Articles

Utilization of graphene oxide for enhancing the heavy metal immobilization of limestone calcined clay cement containing ferronickel slag

This study investigates the use of graphene oxide (GO) into limestone calcined clay cement (LC3) to enhance the immobilization of heavy metal ions from ferronickel slag. Various macro- and micro-characterization techniques, including compressive strength, toxicity characteristic leaching procedure, heat of hydration, X-ray diffraction (XRD), thermogravimetric analysis/derivative thermogravimetry (TGA/DTG), and scanning electron microscopy (SEM), were employed to evaluate the effectiveness of GO on the solidification/stabilization technique. The results reveal that incorporating GO increased the compressive strength of LC3 mortars at both 7 d and 28 d. Additionally, the use of GO improved the immobilization of heavy metal ions, reducing leaching concentrations of Cr and Mn by 20% and 30% at 28 d, respectively. Isothermal calorimetry, TGA/DTG, XRD, and SEM analyses further elucidated the accelerated hydration, mineral crystal phase changes, denser microstructure, and improved interfacial transition zone of GO-modified LC3 mixtures. The study provides the potential of integrating nanotechnology into LC3 cement for environmentally sustainable waste management strategies.

Effect of the structure and volume fraction of nanophase on the mechanical properties of (FeNi)86B14 amorphous nanocrystalline alloys

The influence of precipitated nanophases on the mechanical properties of Fe-based amorphous nanocrystalline alloys is an urgent issue to be explored. Two amorphous nanocrystalline alloys, i.e., (Fe0.9Ni0.1)86B14 and (Fe0.7Ni0.3)86B14 containing nanophase of the body-centered cubic and face-centered cubic structures, respectively, were selected to investigate the effect of the structure and volume fraction of nanophase on their mechanical properties. The results of nanoindentation experiments and the calculation of the volume and size of the shear transition zone reveal that the two alloys show different mechanical properties. When the volume fraction of the nanophase in (Fe0.9Ni0.1)86B14 is larger than 50%, the elastic modulus is increased suddenly and the volume and size of the shear transition zone is decreased dramatically, while no dramatic change occurs in (Fe0.7Ni0.3)86B14. Moreover, it was found by using molecular dynamics simulations that the main reason for these abnormal mechanical properties is the change of cluster type in the system due to the incorporation of nanophases with different structures.

Estimation of phloem conductance at tree level in young, middle-aged and old-aged Scots pine trees growing in different climatic conditions in boreal forests.

In forests, a significant proportion of the carbon fixed by trees during photosynthesis is transported belowground along the conducting phloem, so variations in phloem anatomy can lead to variations in transport capacity. Phloem conductance at tree level (Ktree) is also affected by tree height. Both the phloem anatomy and the tree size change during ontogeny, and also differ under different environmental conditions. The goal of our work was to identify the main drivers of variation in Ktree in Scots pine trees growing in natural boreal forests. We conducted a phloem anatomical study and calculated Ktree in trees of three age groups growing in different climatic conditions along a latitudinal gradient from south to north. We found that Ktree was maintained at the same level in actively growing pine trees (25-80-years-old) but increased in old-aged trees (180-190-years-old), possibly reflecting the shift in source-sink relationships of aboveground and belowground parts of trees. Trees of the same age group growing in different climatic conditions demonstrated similar values of Ktree due to coordinated changes in the phloem anatomy and the tree height. In general, the negative influence of tree height on Ktree is offset by the positive influence of phloem width (or trunk diameter) and sieve cell diameter. The exception was young trees growing in the transition zone of the northern taiga subzone to the tundra, where Ktree was the highest in its age group and even exceeded Ktree of middle-aged trees.

A Reconstruction of May–June Mean Temperature since 1775 for Conchos River Basin, Chihuahua, Mexico, Using Tree-Ring Width

Currently there are several precipitation reconstructions for northern Mexico; however, there is a lack of temperature reconstructions to understand past climate change, the impact on ecosystems and societies, etc. The central region of Chihuahua is located in a transition zone between the Sierra Madre Occidental and the Great Northern Plain, characterized by extreme temperatures and marked seasonal variability. The objectives of this study were (1) to generate a climatic association between variables from reanalysis models and the earlywood series for the center of Chihuahua, (2) to generate a reconstruction of mean temperature, (3) to determine extreme events, and (4) to identify the influence of ocean–atmosphere phenomena. Chronologies were downloaded from the International Tree-Ring Data Bank and climate information from the NLDAS-2 and ClimateNA reanalysis models. The response function was performed using climate models and regional dendrochronological series. A reconstruction of mean temperature was generated, and extreme periods were identified. The representativeness of the reconstruction was evaluated through spatial correlation, and low-frequency events were determined through multitaper spectral analysis and wavelet analysis. The influence of ocean–atmosphere phenomena on temperature reconstruction was analyzed using Pearson correlation, and the influence of ENSO was examined through wavelet coherence analysis. Highly significant correlations were found for maximum, minimum, and mean temperature, as well as for precipitation and relative humidity, before and after the growth year. However, the seasonal period with the highest correlation was found from May to June for mean temperature, which was used to generate the reconstruction from 1775 to 2022. The most extreme periods were 1775, 1801, 1805, 1860, 1892–1894, 1951, 1953–1954, and 2011–2012. Spectral analysis showed significant frequencies of 56.53 and 2.09 years, and wavelet analysis from 0 to 2 years from 1970 to 1980, from 8 to 11 years from 1890 to 1910, and from 30 to 70 years from 1860 to 2022. A significant association was found with the Multivariate ENSO Index phenomenon (r = 0.40; p = 0.009) and Pacific Decadal Oscillation (r = −0.38; p = 0.000). Regarding the ENSO phenomenon, an antiphase association of r = −0.34; p = 0.000 was found, with significant periods of 1 to 4 years from 1770 to 1800, 1845 to 1850, and 1860 to 1900, with periods of 6 to 10 years from 1875 to 1920, and from 6 to 8 years from 1990 to 2000. This study allowed a reconstruction of mean temperature through reanalysis data, as well as a historical characterization of temperature for central Chihuahua beyond the observed records.

Utilization of recycled fine aggregate in ultra-high performance concrete: Mechanical strength, microstructure and environment impacts

Recycled aggregate derived from construction and demolition (C&D) waste offers new opportunities for the construction industry due to the shortage of natural aggregate. This study presents the feasibility of utilizing recycled fine aggregate (RFA) in ultra-high performance concrete (UHPC) to alleviate autogenous shrinkage, mitigate environmental effects, and further improve mechanical strengths. Three types of RFA with different particle sizes (0–0.6 mm, 0.6–1.18 mm, and 1.18–2.36 mm) are pre-saturated and then used as substitutes for quartz sand in UHPC. The influences of pre-saturated RFA on the workability, internal relative humidity, autogenous shrinkage, compressive strength, resistance to chloride ion penetration, and microstructure of UHPC are investigated. Experimental results showed that, compared to the plain UHPC, incorporation of 20 % RFA with particle size of 1.18–2.36 mm provides efficient internal curing, maintaining a higher internal relative humidity, and thus reducing autogenous shrinkage by 78.5 % at the age of 7 days. The compressive strengths of the UHPC containing 20 % RFA with particle size of 1.18–2.36 mm shows 7.1 % increase at the ages of 28 days. While it has a negligible effect on the fluidity and resistance to chloride penetration. The underlying mechanisms for the enhancement of properties involve the improved hydration degree of UHPC due to internal curing, which optimizes the structure of the interface transition zone and reduces the number of large pores. Furthermore, the sustainability analysis indicated that the use of RFA in UHPC exhibits 7.0 % lower carbon emissions and 7.8 % lower energy consumption, respectively. This study successfully proposes an effective approach for mitigating the autogenous shrinkage of UHPC without sacrificing strengths.

Study on the mechanical properties of recycled brick coarse aggregate concrete based on finite element modeling

In recent years, the use of recycled materials in concrete production has garnered significant attention due to their environmental and economic benefits. To promote the application of recycled aggregates, this study focuses on investigating the utilization of Recycled Brick Coarse Aggregate (RBCA) as a substitute for natural aggregate. This paper presents the development of stochastic convex polygonal RBCA through the utilization of a custom-programmed algorithm and proposes a finite element model designed to simulate the behavior of RBCA concrete under compression and splitting tensile. Numerical simulations were conducted to investigate the effects of brick aggregate Replacement Rate (RR) and porosity on the compressive and splitting tensile properties of RBCA concrete. A strong correlation was found between the Concrete Damage Plasticity (CDP) model developed in this study and experimental results, indicating high reliability. The results indicate that the replacement rate of brick aggregates has a more significant impact on the compressive strength than on the splitting tensile strength of concrete. Furthermore, the distribution of coarse aggregates and pores has a minor influence on the mechanical properties and ultimate failure mode of RBCA concrete but significantly affects the crack distribution pattern. The sequence of damage initiation in RBCA concrete was found to be: pores, old Interfacial Transition Zone (ITZ), old mortar, new ITZ, new mortar, RBCA, and Natural Coarse Aggregate (NCA). These findings contribute to a comprehensive understanding of RBCA's performance and offer valuable insights for optimizing its behavior.

Retrospective Study of Multimodality Imaging Features of Chondroblastoma

Abstract Purpose To evaluate the multimodality imaging features of chondroblastoma. Materials and Methods Retrospective analysis of imaging features of 52 cases of histopathologically proven chondroblastoma from 2010 to 2022 was performed. Radiographs were evaluated for lesion site, location, morphology, margins, matrix mineralization, cortical breach, periosteal reaction, eccentricity, and subarticular extension. Appearance on T1, T2 weighted and post-contrast T1 was evaluated on MRI, with analysis of peritumoral edema and joint effusion. Results Mean patient age was 18 years (10–57 years) with male preponderance (M = 39; F = 13). 75% (n = 39) cases involved an unfused skeleton and 25% (n = 13) affected a mature skeleton. Appendicular skeleton was involved in 88.5% (n = 46) cases and axial skeleton was involved in 11.5% (n = 6) cases with all cases involving epiphysis/epiphyseal equivalent. Radiographically, all cases were well-defined geographic osteolytic lesions with a narrow zone of transition, thin sclerotic rim and lobulated [56% (n = 29)] or smooth [44% (n = 23)] margins. Matrix calcification appreciable in 62% (n = 32) cases was ‘fluffy/smudgy’. Chondroblastoma appeared isointense (83%, n = 43) on T1 MRI with characteristically low signal and hyperintense foci within (67%, n = 35) on T2-weighted images and post-contrast enhancement [heterogeneous lobular (88%, n = 46) or septal pattern (12%, n = 6)] with all barring three lesions showing perilesional edema. None of the cases of chondroblastoma in our study developed metastasis till last follow-up (mean: 71 months). Conclusion Chondroblastoma has distinctive imaging appearance and is often unlike majority other cartilaginous benign lesions due to characteristic low T2 signal on MRI and associated exuberant perilesional edema.

Spatiotemporal Evolution and Coupling Analysis of Human Footprints and Habitat Quality: Evidence of 21 Consecutive Years in China

Assessing the spatiotemporal evolution characteristics of habitat quality, human footprint, and coupling coordination between two systems in continuous cycles and on national scales is of great significance to maintaining biodiversity and sustainable development. This study took China as an example, based on land-use data from 2000 to 2020, using the Integrated Valuation of Ecosystem Services and Tradeoffs—Habitat Quality (InVEST-HQ) model and the human footprint framework, coupling trend analysis methods such as Theil–Sen Median Analysis, Mann–Kendall Test, and Grid Transition Matrix (GTM) Method and combining the four-quadrant model and the coupling coordination degree model (CCDM) to reveal the spatiotemporal evolution characteristics of habitat quality, human footprint, and CCDM in China for 21 consecutive years and the response relationship between the two systems of habitat quality and human footprint. The results show that the land cover change area from 2000 to 2020 accounted for 4.2% of the total area. Both habitat quality and human footprints exhibit apparent spatial heterogeneity along the “Hu Line” and generally fall into two evolutionary stages: “degradation–improvement”. The proportions of degradation and improvement were 14.37% and 8.36%, respectively, and the mutation point was in the year 2013; the average human footprint increased by 16.75%, and the increased and decreased area proportions were 63.40% and 21.53%, respectively. The mutation occurred in 2014. The right side of the “Hu Line” primarily hosts areas with high values of the coordinated coupling index of human footprints and habitat quality systems. The four quadrants generally have the following characteristics: “quadrant IV on the right is dominant, quadrants II and III on the left are dominant, and quadrant I is located in the transition zone of the ‘Hu Line’”. The coupling coordination degree (CCD) and human footprints have a weak, nonlinear “inverted U-shaped” relationship. This study provides compelling evidence for the spatiotemporal evolution and coupling relationship between habitat quality and human footprint in China, provides scientific decision-making support for biodiversity protection and sustainable economic development, and maintains the bottom line of ecological security for a beautiful China.

Measurement of T1ρ dispersion with compressed sensing and magnetization prepared radial balanced steady-state free precessionin spontaneous human osteoarthritis.

To assess the potential for accelerating continuous-wave (CW) T1ρ dispersion measurement with compressed sensing approach via studying the effect that the data reduction has on the ability to detect differences between intact and degenerated articular cartilage with different spin-lock amplitudes and to assess quantitative bias due to acceleration. Osteochondral plugs (n = 27, 4 mm diameter) from femur (n = 14) and tibia (n = 13) regions from human cadaver knee joints were obtained from commercial biobank (Science Care, USA) under Ethical permission 134/2015. MRI of specimens was performed at 9.4T with magnetization prepared radial balanced SSFP (bSSFP) readout sequence, and the CWT1ρ relaxation time maps were computed from the measured data. The relaxation time maps were evaluated in the cartilage zones for different acceleration factors. For reference, Osteoarthritis Research Society International (OARSI) grading and biomechanical measurements were performed and correlated with the MRI findings. Four-fold acceleration of CWT1ρ dispersion measurement by compressed sensing approach was feasible without meaningful loss in the sensitivity to osteoarthritic (OA) changes within the articular cartilage. Differences were significant between intact and OA groups in the superficial and transitional zones, and CWT1ρ correlated moderately with the reference measurements (0.3 < r < 0.7). CWT1ρ was able to differentiate between intact and OA cartilage even with four-fold acceleration. This indicates that acceleration of CWT1ρ dispersion measurement by compressed sensing approach is feasible with negligible loss in the sensitivity to osteoarthritic changes in articular cartilage.

Cross-border perception of Bayising (Pansheng 板升) among government officials in Ming China

The Mongol Yuan dynasty in China officially came to an end in 1368 with the withdrawal of the Mongols from the capital city Daidu (Beijing) and their retreat to the steppes. Nevertheless, a protracted series of military campaigns and conflicts between the Ming court and the Eastern Mongols, Oirat Mongols, and various other Mongol tribes continued for about 200 years. This article examines the discourse surrounding Bayising, where a group of Chinese people settled on Mongolian territory and served the Mongols during the mid-16th and early-17th centuries. The primary population of Bayising consisted of Chinese individuals who had either fled from China or were captives taken by the Mongols from China in border raids. Bayising embodies a unique interaction between China and nomadic communities in a transitional zone between the steppe and agricultural land, where conventional trading and tribute systems encountered difficulties in establishment. After the signing of the 1571 peace treaty, Bayising gradually receded from the focus of the Ming court. Through an analysis of historical documents and records, this article unveils the perspectives held by Ming officials regarding Bayising. Additionally, it probes into how these perspectives influenced Ming China’s foreign relations and national security policies concerning the Mongols. The emergence of Bayising was rooted in a distinctive historical context. Moreover, Bayising played an important role not only in shaping Sino-Mongol relations but also in facilitating cooperation between nomadic and agricultural communities in the absence of official trade channels. Neither repatriation nor military intervention proved to offer fundamental solutions to the Bayising issue in the ongoing confrontation between the Mongols and the Ming court. However, the establishment of normalised and stabilised trade, facilitated by a mutually beneficial peace treaty, emerged as a definitive solution that ultimately benefited both parties. This intricate interplay between geopolitical dynamics and cultural exchanges underscores the complexity of historical narratives, emphasizing the enduring impact of the Ming officials’ perception of the Mongols on regional stability and economic prosperity.

Interface reconstruction of MXene-Ti3C2 doped CeO2 nanorods for remarked photocatalytic ammonia synthesis

Prospective photocatalytic ammonia synthesis process has received more attentions but quite challenging with the low visible light utilization and weak N2 molecule absorption ability around the photocatalysts. Herein, interface reconstruction of MXene-Ti3C2/CeO2 composites with high-concentration active sites through the carbon-doped process are presented firstly, and obvious transition zones with the three-phase reaction interface are formed in the as-prepared catalysts. The optimal co-doped sample demonstrates an excellent photo response in the visible light region, the strongest chemisorption activity and the most active sites. Moreover, much more in-situ extra oxygen defects are also produced under light irradiation. It is expected that the double decorated catalyst shows a remarked ammonia production rate of above 0.76 mmol gcal−1·h−1 under visible-light illumination and a higher apparent quantum efficiency of 1.08 % at 420 nm, which is one of the most completive properties for the photocatalytic N2 fixation at present.

Fracture mechanical properties and interfacial characteristics of engineered cementitious composites containing coarse aggregate

Engineered cementitious composites (ECC) have significantly high deformability, but their application in the field of engineered crack prevention is severely limited by their high shrinkage and high cost. To address this issue, a safer and more economical ECC was designed in this paper by adding coarse aggregate (CA) into the ECC matrix (i.e., ECC-CA). Then, experimental studies on the fracture properties of ECC-CA were carried out from both macroscopic and microscopic perspectives, by considering four CA mass contents and three CA particle sizes. The results show that ECC-CA maintains good mechanical properties and deformation capacity as ECC. Its crack mouth opening displacement corresponding to the largest particle size (13–17 mm) and the largest mass content (30 %) is equivalent to 47.8 % of that of ECC, which is about 40 times higher than that of conventional concrete. Further, the interfacial transition zone characteristics between each phase medium and matrix were analyzed in ECC-CA for the purpose of clarifying the crack initiation and evolution trends, elucidating the influence of CA on the fracture mechanism of ECC-CA (i.e., fiber cage effect) based on both macroscopic performance and microscopic characteristics.

Ultrasonic wave characteristics in multiscale cementitious materials at different stages of hydration

Monitoring the microstructural change in cementitious materials during hydration is an essential but challenging task. Therefore, a non-invasive and sophisticated technique is warranted to understand the microscopic behaviour of the multiphase cementitious materials (where the length scale of the constituents varies from centimeters to micrometers) in different stages of hydration. Due to exothermic hydration reactions, different hydration products start to evolve with individual mechanical properties. In concrete, an interface transition zone (ITZ) appears between the aggregate surface and paste matrix, which influences the overall properties of concrete material. In the present research, 1) several wave characteristics, such as wave velocity, energy distribution, and signal phase are found out using Ultrasonic Pulse Velocity (UPV), Wavelet Packet Energy (WPE) and Hilbert Transform (HT) methods, to monitor the hydration mechanism (1d-28d) in cement-based materials with two levels of heterogeneities (cement paste and concrete, representing microscale and mesoscale, respectively). Also, the unique nonlinear behaviour is studied in the frequency domain using the promising Sideband Energy Ratio (SER) and Sideband Peak Count Index (SPC-I) methods. 2) Numerical simulations are carried out to understand the wave interaction in the developing microstructure. A discretized microstructure of cement shows microscopic details of each phase at any instant of hydration (e.g., formation stage and after complete maturity level). The experimental and numerical investigations on the characteristics of the nonlinear ultrasonic wave propagation show the impact of microstructural development of multi-scale cementitious materials during hydration.

Colposcopically Directed Biopsy Before Ablative Treatment Versus Direct Ablative Treatment in Patients With Cervical Oncogenic HPV.

In the past, the standard of care for women with abnormal cervical cytology has been the performance of colposcopically guided biopsy, followed by conization or large loop excision of the transition zone (LLETZ) where biopsy revealed pre-cancerous or cancerous areas. More straightforward protocols are emerging which advocate performing LLETZ in all women with highly suspicious cytology, suspicious colposcopic impression, or the presence of high-risk oncogenic human papilloma virus (HPV) strains in their cervical swabs. This, theoretically, would reduce the rate of false-negative diagnoses, but at the price of overtreating a significant number of healthy women. We retrospectively analyzed cervical cancer screening protocols in two large cohorts of women with high-risk HPV. The study compared outcomes between patients undergoing a colposcopically directed biopsy before LLETZ (n=683) and those proceeding directly to LLETZ without a biopsy (n=136). The primary focus was to assess whether intervening biopsies would reduce unnecessary ablative procedures without compromising the detection of high-grade lesions. The biopsy group had a high false-negative rate, with several high-grade lesions (CIN3) and a case of invasive cancer initially underdiagnosed. Conversely, the direct-to-LLETZ approach, while ensuring no high-grade lesions were missed, led to overtreatment of lower grade lesions. These findings raise concern about the reliance on biopsy results for treatment decisions. Neither protocol was entirely satisfactory, although the more aggressive one avoided the potentially life-threatening consequence of false-negative results. Further research is mandatory to accurately diagnose all cases requiring aggressive treatment, without subjecting healthy women to ablative treatments they do not need.

The Future of Coastal Navigation Safety in Egypt: Improving the Reliability of Electronic Charts

Abstract This paper investigates the integrity and reliability of electronic navigation charts (ENCs) used for maritime navigation along the Egyptian coast. Comprehensive assessments were conducted, focusing on critical stretches including the Suez Canal, Strait of Jubal, Aqaba Gulf entrance, and Hurghada Port access channels. The findings expose alarming accuracy gaps in these vital yet confined transit zones, with Category of Zone of Confidence (CATZOC) classification results indicating positional uncertainties exceeding five hundred meters. Such imprecision severely erodes navigational safety buffers for ships amidst intense traffic volumes. Meanwhile, proximity to delicate coral ecosystems and coastal communities raises the stakes for averting accidents. Responding to these urgent threats, promising initiatives are already underway between Egyptian agencies and international hydrographic bodies to systematically address ENC deficiencies through new surveys and data enhancements. Mandatory functionality checks, crew training, and compliance enforcement will also optimize the utilization of existing ECDIS installations. Sustained investments to upgrade this core informational infrastructure will help align the country's navigational framework with best practices for protecting life, property, and the environment. A multifaceted strategy tackling both human and technical dimensions across ships, ports, and shoreside administrators is essential for eliminating needless risk. Strengthening ENC integrity will provide Egyptian-flagged and visiting vessels with greater situational assurance when transiting confined waterways, while preventing devastating shipping accidents that could damage fragile marine ecosystems.

Effect of modifiers on the properties of bamboo scraps/magnesium oxychloride composites under dry-wet cycling environments

Bamboo scraps/magnesium oxychloride composites (BS/MOC) is a new low-carbon and eco-friendly building material, which is composed of magnesium oxychloride cement (MOC) as the matrix and bamboo scraps as the reinforcing materials. However, the poor strength and durability of BS/MOC under special environmental conditions seriously restrict its application range. To solve the above problems, citric acid (CA), D-gluconic acid sodium salt (GS), and styrene-acrylate emulsion (SAE) were used as modifiers to improve BS/MOC properties. The effect of modifier addition on the mechanical strength and durability of BS/MOC was investigated under dry-wet cycling environments. The phase composition, microstructure, pore structure, and Clˉ concentration of BS/MOC were characterized by XRD, TGA, SEM, MIP, and ICS-600. The results showed that CA and GS improved the interface adhesion between bamboo scraps and MOC matrix, and both inhibited the hydration reaction of the residual MgO and the hydrolysis of phase 5 crystals, resulting in good mechanical properties and microstructural stability of BS/MOC under dry-wet cycles. GS outperformed CA in refining pore structure, improving mechanical properties and durability of BS/MOC under identical dry-wet cycles. Conversely, the addition of SAE increased initial defects and interfacial transition zones in the BS/MOC matrix, and increased the total porosity and the harmful pores content, which negatively affected the mechanical properties and durability of BS/MOC.

A prospective evaluation of the prostate microbiome in malignant and benign tissue using transperineal biopsy

AbstractBackgroundThe link between the prostate microbiome and prostate cancer remains unclear. Few studies have analyzed the microbiota of prostate tissue, and these have been limited by potential contamination by transrectal biopsy. Transperineal prostate biopsy offers an alternative and avoids fecal cross‐contamination. We aim to characterize the prostate microbiome using transperineal biopsy.MethodsPatients with clinical suspicion for prostate cancer who were to undergo transperineal prostate biopsy with magnetic resonance imaging (MRI) fusion guidance were prospectively enrolled from 2022 to 2023. Patients were excluded if they had Prostate Imaging Reporting and Data System lesions with scores ≤ 3, a history of prostate biopsy within 1 year, a history of prostate cancer, or antibiotic use within 30 days of biopsy. Tissue was collected from the MRI target lesions and nonneoplastic transitional zone. Bacteria were identified using 16S ribosomal RNA gene sequencing.ResultsAcross the 42 patients, 76% were found to have prostate cancer. Beta diversity indices differed significantly between the perineum, voided urine, and prostate tissue. There were no beta diversity differences between cancerous or benign tissue, or between pre‐ and postbiopsy urines. There appear to be unique genera more abundant in cancerous versus benign tissue. There were no differences in alpha diversity indices relative to clinical findings including cancer status, grade, and risk group.ConclusionsWe demonstrate a rigorous method to better characterize the prostate microbiome using transperineal biopsy and to limit contamination. These findings provide a framework for future large‐scale studies of the microbiome of prostate cancer.

Optimization of the SAGD Preheating for the Athabasca Oil Sands Reservoir with a Water Transition Zone

Optimization of the SAGD Preheating for the Athabasca Oil Sands Reservoir with a Water Transition Zone

Cleaner Production of Cementitious Materials Containing Bioaggregates Based on Mussel Shells: A Review

This text provides a bibliographic review on bioaggregates obtained from mussel shells and similar materials, evaluating the main properties altered with the use of this type of recycled aggregate in cementitious materials. The bibliographic analysis highlights the main problems and challenges of using bioaggregates related to the presence of organic impurities and chlorides and due to the lamellar and flat shape of the grains, which impair adhesion in the transition zone. The advantages of mussel shell bioaggregates include their limestone-based chemical composition, properties that are inert and compatible with the application, and a specific mass close to conventional aggregates. Regarding their use in cementitious materials, in general, there is a reduction in workability and an increase in incorporated air, porosity, and water absorption, resulting in a reduction in compressive strength. However, it is observed that lower replacement levels make it possible to use bioaggregates, especially fine aggregates, in cementitious materials for different applications, such as structural concrete, coating mortar, and sealing systems. The positive points are related to the promotion of thermal insulation and the reduction in density, which allow for various uses for cementitious materials with bioaggregates, such as lightweight concrete, permeable concrete, and thermal and acoustic insulation mortars. It is concluded that the use of bioaggregates in concrete and mortars is viable, but the need for more experimental work to solve the main problems encountered, such as high water absorption and low compressive strength, is highlighted.

Micromechanical and chemical characteristics of interfacial transition zone in alkali-activated slag concrete containing lightweight iron-rich aggregates

This study explored the time-varying alkali-activation effects of the lightweight aggregates (LWA) on the interfacial transition zone (ITZ) of the alkali-activated slag concrete with different curing ages, molar ratios, and alkali concentrations from 28 to 300 d. The improved micromechanical performance of the ITZ at 28 d stemmed from the early-age internal curing effect of the porous LWA. However, the post-28 d internal curing effect diminished, with the alkali-activation dominating the performance of the ITZ from 28 to 300 d. Although alkali-activated cement possessed early strength characteristics, the deconvolved phase results illustrated that alkali activation persisted in the ITZ between the LWA and cement from 28 to 300 d, leading to a high proportion of calcium silica aluminate hydrate. As a marker, Fe from the lightweight iron-rich aggregates mitigated into the alkali-activated cement, demonstrating the alkali-activated reaction between the LWA and alkali-activated slag matrix. Molecular dynamics simulations further characterized that the low content of Fe did not decrease the overall strength of the ITZ. The interfacial interaction energy revealed the alkali-activation between the LWA and cement compensated for the weakening of mechanical properties caused by Fe ions on the ITZ.