Transformation Rate Research Articles

The silicon isotopic compositions of silica sinters in Xizang, China: Implications for paleo-geothermal activities since 0.5 Ma B.P.

The diagenetic sequence from opal-A to opal-CT has been observed in geothermal systems worldwide. Xizang, a unique geothermal region in the world, has experienced several large-scale geothermal activities since 0.5 million years ago. The Targejia and Gulu geothermal systems were investigated in this study. The time for transformation from opal-A to opal-CT varies, indicating that the rates of silica phase transformation depend on specific conditions; however, their silicon isotopic compositions are not significantly different, ranging from −1.0‰ to −0.3‰ in Targejia and from −1.1‰ to −0.1‰ in Gulu. Additionally, silica sinters undergo varying degrees of diagenesis, as supported by different time periods and varying degrees of ordering. The δ30Si values of different phases, opal-A and opal-CT, also did not significantly change, ranging from −1.1‰ to −0.3‰ for opal-A and from −1.0‰ to −0.1‰ for opal-CT. Due to the lower dissolution rates of sediments, high aluminum content, and reduced reactivity of silica sinters, the δ30Si values of silica sinters are less susceptible to secondary modifications, and the initial information after the silica sinters formation is well preserved. Hence, the isotopic signatures of silica sinters reflect various depositional environments and can be used to reconstruct paleo-geothermal activity. The narrow range and slightly negative isotopic values of silica sinters suggest that large-scale high-temperature geothermal activity has occurred in different regions since 0.5 Ma. The diagenesis of silica sinters may have been influenced by postlarge-scale high-temperature geothermal activity. Such large-scale, high-temperature and long-term natural eruptions in geothermal fields are typically associated with magmatic activity, possibly caused by crustal remelting processes.

Determination of phase transformation kinetics under magnetic fields: Modeling based on magnetization and application in a Fe-1 wt.%Cu alloy

A phase transformation model based on magnetization is proposed in this paper, which accurately tracks the change in the phase transformation volume fraction with time/temperature f-T/t by analyzing phase transformation magnetization curves under a magnetic field. This allows for the determination of kinetic parameters related to the nucleation and growth processes such as the phase transformation rate df/dt-T/t and Avrami exponent n, enabling quantitative analysis of phase transformation kinetics under magnetic field effects. Additionally, the phase transformation magnetization under a magnetic field can be accurately fitted by combining the volume fraction calculation model with the Johnson–Mehl–Avrami equation, thus also obtaining the kinetics parameters. The aforementioned two models are applied to study the isothermal and isokinetic transformations of austenite (γ) to ferrite (α) in Fe-1 wt. %Cu alloys, demonstrating the effects of external conditions through variations in kinetic parameters.

Benign extra skeletal chondroma of the tongue in a 16-year-old female

Chondromas are tumors that result from chondroid differentiation most frequently occurring in areas where chondrocytes are present. Rarely, they can present in soft tissues, such as the tongue. This case report will review the extra skeletal chondroma found on the posterior tongue of an asymptomatic 16-year-old female. Discussed within this case report will include the importance of histopathological analysis in distinguishing enchondroma versus chondrosarcoma and review the malignant transformation rate. Additionally, it will compare the trends of chondromas found in the oral cavity that have been previously published. This case will highlight the importance of recognizing chondromas in unusual places, such as the origin of soft tissues, and emphasize the importance of early diagnosis, surgical intervention and providing optimal outcomes for young patients.

Digitalization of Legal Transformation on Judicial Review in the Constitutional Court

Efficient, affordable, and uncomplicated justice poses a complex dilemma within the Indonesian judicial system. However, applying technological advancements to assessing legal regulations can resolve this issue. This research aims to examine the necessity and implementation of digitalization in the Constitutional Court's judicial review process. This research utilized a normative legal approach, characterized by its prescriptive and applied nature, to examine the development and implementation of digitalization in the justice systems of the European Union, the United States, and the United Kingdom through comparative studies. The research results show that: first, technology in the Constitutional Court's judicial review process can most effectively promote openness and clarity in the decision-making procedure. However, there remain several areas in which the Constitutional Court must further refine itself to attain digital status, as inconsistencies persist in its practical rulings. Consequently, the Constitutional Court must increase the rate of digital transformation in its judicial review operations. Second, numerous other nations, including the European Union, the United Kingdom, and the United States, have observed the implementation of technological advancements, leading to enhanced transparency and accessibility in their justice systems. Thirdly, to overcome the challenges above, we must apply the fundamental principles of good judicial governance, procedural law at the Constitutional Court, the paperless principle, and the contactless service principle when developing digital transformation for future judicial review at the Court. This will enable us to achieve transparency and accessibility in the Constitutional Court's judicial system.

Advancements in Genetic Enhancement: CRISPR/Cas-Mediated Genome Editing in Leguminous Crops

Legumes play a crucial role in human nutrition and sustainable agriculture due to their high protein content and health-promoting phytochemicals. To accelerate genetic gain in yield, stress resilience, and nutritional quality, extensive efforts are underway. Recent advancements in genomic resources have paved the way for the application of cutting-edge breeding technologies like genomic selection and genome editing in legume crops. This review focuses on the latest advancements in CRISPR/Cas9-based gene editing technology, specifically tailored for improving traits in legume crops. While successful gene-editing methods have been established for crops like soybean, cowpea, and chickpea, challenges remain, particularly in overcoming the recalcitrance of certain legumes to gene transfer and regeneration in vitro. Strategies to enhance transformation and regeneration rates through modifications in culture methods and DNA delivery are discussed. Despite the potential benefits of gene editing in legume breeding, regulatory barriers pose significant challenges. A comparison of regulatory environments in different regions sheds light on the importance of favourable regulations and public acceptance for realizing CRISPR's potential in enhancing global food security. Additionally, leguminous crops are vital for their nutritional properties, nitrogen-fixing abilities, and contribution to sustainable agriculture. Traditional breeding methods focused on increasing yield, while recent advancements in genome editing techniques, notably CRISPR-Cas technology, have revolutionized the improvement of agronomic traits in legumes. This chapter provides insights into the application of genome editing tools for enhancing traits such as stress tolerance, yield, and seed content in grain legumes. Furthermore, it discusses the challenges and prospects associated with enhancing grain legumes using molecular breeding techniques. Genome editing has been successfully employed in diverse legumes, including model species like Medicago and widely cultivated crops such as soybean and chickpea, offering exciting opportunities for enhancing agronomic characteristics.

#1803 Is class II lupus nephritis as benign as one thinks?

Abstract Background and Aims The classification of Lupus Nephritis (LN) plays a pivotal role in determining prognosis and guiding treatment, aligning with ISN/RPS recommendations. KDIGO and EULAR advocate for immunosuppression in cases of proliferative LN (Class III/IV) and Class V with nephrotic syndrome, while “non-proliferative” instances (Class I and II) are advised conservative care. In a contrasting approach, GLOSEN recommends immunosuppression for Class II if persistent proteinuria exceeds 1g. ISN/RPS suggests incorporating activity and chronicity indexes to further refine the classification of LN. Concerns surrounding immunosuppression in LN Class II arise from its favorable long-term kidney survival and potential drug toxicity. However, the need for caution is underscored by a 30–50% class transformation rate. Limited research comparing the long-term prognosis of treated and untreated patients exists due to the gradual progression of the disease. The use of Activity (NIH-A) and Chronicity (NIH-C) indexes, particularly in the context of protocol biopsies, offers an opportunity to reassess the perceived benign nature of LN Class II. Method In this single-center investigation, patients diagnosed with LN belonging to Class II or II+V from 1999 to 2021 were examined. Biopsies were classified according to ISN/RPS criteria and evaluated using the NIH-A and NIH-C Indexes. Patients previously diagnosed with Class III/IV LN and those experiencing class transformation to a proliferative class were excluded. We present the findings in a descriptive manner. Results Sixteen patients, with a median age of 38.5 (12 female), were included. Histological findings from the initial biopsies revealed a NIH-A of 0, with NIH-C exceeding 0 in 31% (5/16) cases. Six patients exhibited Class II plus V, with varying NIH-C scores. The primary contributors to NIH-C in the initial biopsies were tubular atrophy and interstitial fibrosis. Ten patients underwent a second biopsy after an average time lapse of 39 months (7-101). The decision for most second biopsies was based on clinical judgment rather than a standardized protocol. One patient initially diagnosed with Class II+V displayed Class II on the second biopsy, and vice versa. In 70% of patients the NIH-C increased, primarily driven by glomerulosclerosis. The rise in NIH-C scores was observed in 3/6 patients with Class II+V and in all 4 patients with isolated Class II. Most patients received mycophenolate, and 3 were treated with low-dose prednisolone. The clinical and histologic characteristics of the 10 patients who underwent a second biopsy are outlined in Tables 1 and 2. Conclusion Our limited, biased study raises questions rather than providing definitive evidence. The consistent NIH-C rise challenges Class II LN perceived benign nature. It is plausible that not all LN Class II cases are equivalent and histological variances, such as mesangial proliferation, or its focal or diffuse distribution impact outcomes. Histological variations and treatment impact on LN Class II warrant further investigation.

Experimental and Modelling Research on the Effect of Prior Ferrite on Bainitic Transformation in Medium-Carbon Bainitic Steel

In this study, we investigate the impact of prior ferrite on the bainite transformation kinetics and microstructure of medium-carbon steel interrupted by an intercritical annealing (IAA) process. It was found that the incubation time and completion time decreased from 687 s and 6018 s to 20 s and 4680 s, with the volume fraction of ferrite increasing from 9.5% to 28.6%, while the maximum transformation rate increased from 00271 μm/s to 0.0436 μm/s. The ferrite/austenite interface is introduced, and the nucleation sites are increased to accelerate the subsequent bainite transformation due to the formation of prior ferrite. However, there is a competitive relationship between the number and activation energy of bainite nucleation. According to the experimental results and theoretical calculations, the activation energy of the bainite transformation in the medium-carbon bainite steel decreases gradually with an increase in the volume fraction of prior ferrite.

The coupling transformation process of biodegradation and pyrolysis for Dananhu low-rank coal

The study presented a novel approach for coupling biodegradation and pyrolysis to transform low-rank coal. In the first stage, four kinds of bacteria, Planomicrobium huatugouensis (P. huatugouensis), Sphingomonas polyaromaticivorans (S. polyaromaticivorans), Pseudomonas putida (P. putida), and Bacillus subtilis subsp. subtilis (B. subtilis subsp. subtilis), were used to transform the Dananhu low-rank coal. After the first stage, the coal that has not been biodegraded (residual coal) undergoes the second stage of pyrolytic transformation, which is carried out by a thermogravimetric analyzer combined with Fourier-transform infrared spectrometry (TG-FTIR). The results showed that the maximum coupling transformation rate of biodegradation and pyrolysis could reach 73.95%, which was 21.88% higher than the thermal transformation rate of Dananhu low-rank coal and 27.37% higher than the optimal microbial transformation rate. This indicated that coupling transformation could significantly improve the utilization rate of Dananhu low-rank coal. In the stage of biodegradation transformation, bacteria destroyed the carboxyl groups, ether bonds, and other oxygen-containing functional groups in Dananhu low-rank coal, converting the large molecules of coal into liquid molecules, meanwhile, the compact coal structure became loose, and the residual coal was also pyrolyzed easily than Dananhu low-rank coal. During the pyrolysis process, a large number of fatty chains, carboxyl groups, oxy groups, and hydroxy groups were decomposed to produce lots of gas-phase products. The pyrolysis products showed an increase in the release of CO and CH4, and an increase in the proportion of aliphatic hydrocarbons in the volatiles. The high efficiency of coupling transformation is due to the combination of the advantages of the two technologies, which is achieving the green and energy-efficient utilization of low-rank coal.

Formulation of Feeds Intended For Livestock of Cyprinus Carpio in the Vakinankaratra Region, Madagascar

In order to promote the nourishment of carp in farming, four foods have been created from traditional raw materials and containing different quantities of locally produced banana flour 3%, 6%, 10%. We tested these foods which contain 36% crude proteins and 8% lipids on carp fry with an initial weight of 9g. After 50 days of experiment, the final weights of the fish fluctuated between 121.53g and 122.45g depending on the treatments used. The food containing 10% banana flour and the control food showed the highest growth and food transformation rates, with specific growth rates (SGR) of 5.18%/d and 5.14% /d as well as a conversion rate of 1.17 and 1.15 while the food with 6% banana flour obtained a SGR of 5.15 and a conversion index (CI) of 1.15 while that the food with 3% obtained a SGR of 5.14 and a CI of 1.16. Thanks to this test, we were able to observe the impact of bananas on the premature development of tilapia. We will continue to study the use of local agri-food by-products and waste in feeding this fish.

Two-Dimensional Customer Segmentation for Digital Custom Coupon Issuance Approach

With the improvement of large information and profound learning innovation, enormous information and profound learning innovation have likewise been applied to the showcasing field, which was a piece of business organization. Client agitate the board is one of the main areas of promoting. In this paper, we proposed a technique to forestall client beat and increment buy transformation rate by giving tweaked rebate coupons to clients with high stir rate in light of huge information continuously. In the wake of sectioning client portions with two-layered fragment examination, a continuous beat rate assessment model in light of clickstream information was created for each portion. From that point onward, we gave tweaked coupons to our clients. At last, we tried the transformation rate and deals development. A two-layered group investigation based stir rate assessment joined with a proposal framework was viewed as essentially more helpful than the particular straightforward models. Utilizing this proposed model, it is feasible to increment deals via consequently assessing the client's stir likelihood and shopping penchant without the weight of showcasing costs in the web based shopping center

Effect of Mo and Cr on the Microstructure and Properties of Low-Alloy Wear-Resistant Steels.

Low-alloy wear-resistant steel often requires the addition of trace alloy elements to enhance its performance while also considering the cost-effectiveness of production. In order to comparatively analyze the strengthening mechanisms of Mo and Cr elements and further explore economically feasible production processes, we designed two types of low-alloy wear-resistant steels, based on C-Mn series wear-resistant steels, with individually added Mo and Cr elements, comparing and investigating the roles of the alloying elements Mo and Cr in low-alloy wear-resistant steels. Utilizing JMatPro software to calculate Continuous Cooling Transformation (CCT) curves, conducting thermal simulation quenching experiments using a Gleeble-3800 thermal simulator, and employing equipment such as a metallographic microscope, transmission electron microscope, and tensile testing machine, this study comparatively investigated the influence of Mo and Cr on the microstructural transformation and mechanical properties of low-alloy wear-resistant steels under different cooling rates. The results indicate that the addition of the Mo element in low-alloy wear-resistant steel can effectively suppress the transformation of ferrite and pearlite, reduce the martensitic transformation temperature, and lower the critical cooling rate for complete martensitic transformation, thereby promoting martensitic transformation. Adding Cr elements can reduce the austenite transformation zone, decrease the rate of austenite formation, and promote the occurrence of low-temperature phase transformation. Additionally, Mo has a better effect on improving the toughness of low-temperature impact, and Cr has a more significant improvement in strength and hardness. The critical cooling rates of C-Mn-Mo steel and C-Mn-Cr steel for complete martensitic transition are 13 °C/s and 24 °C/s, respectively. With the increase in the cooling rate, the martensitic tissues of the two experimental steels gradually refined, and the characteristics of the slats gradually appeared. In comparison, the C-Mn-Mo steel displays a higher dislocation density, accompanied by dislocation entanglement phenomena, and contains a small amount of residual austenite, while granular ε-carbides are clearly precipitated in the C-Mn-Cr steel. The C-Mn-Mo steel achieves its best performance at a cooling rate of 25 °C/s, whereas the C-Mn-Cr steel only needs to increase the cooling rate to 35 °C/s to attain a similar comprehensive performance to the C-Mn-Mo steel.

Malignant Transformation of Dysplastic Vocal Fold Lesions

The reported rates of malignant transformation of dysplastic laryngeal lesions are highly variable, as is time to malignant degeneration. To evaluate the rate of and time to malignant transformation of dysplastic laryngeal lesions based on the World Health Organization (WHO) dysplasia classification system. PubMed, MEDLINE, Embase, CINAHL, CENTRAL, and Cochrane Reviews were searched from the date of database inception to June 8, 2023. English-language articles assessing the rate of malignant transformation using the 2005 WHO dysplasia classification system were included in this systematic review and meta-analysis. The study was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data extraction was performed by 2 independent investigators. Study quality was assessed using a validated quality tool. When possible, data were pooled using random-effects meta-analysis. The primary outcome measure was the malignant transformation rate in each laryngeal dysplasia category. Secondary outcome measure was the time interval over which malignant transformation had occurred. A total of 5585 records were screened, 61 full texts were assessed, and 18 retrospective cohort studies with 3243 participants were included in the final review. The weighted pooled mean malignant transformation rates of mildly, moderately, and severely dysplastic lesions were 10.9%, 23.3%, and 30.5%, respectively. Malignant transformation rate of nondysplastic laryngeal lesions was 4.5%. Moderately and severely dysplastic lesions had significantly higher odds of malignant transformation compared with mildly dysplastic lesions (moderate: odds ratio [OR], 2.90 [95% CI, 2.06-4.09]; I2 = 0%; severe: OR, 3.42 [95% CI, 2.11-5.52]; I2 = 40%). Lesions without dysplasia had a significantly lower odds of malignant transformation compared with lesions with mild dysplasia (OR, 0.48; 95% CI, 0.28-0.81; I2 = 0%). The overall mean time to malignant transformation was 28.8 months (range, 22.0-35.6 months) for all dysplasia grades. This systematic review and meta-analysis found that the rate of malignant transformation increased with the grade of laryngeal dysplasia. Moderately dysplastic lesions were more likely to undergo malignant degeneration compared with mildly dysplastic lesions.

Role of amelogenin phosphorylation in regulating dental enamel formation

Amelogenin (AMELX), the predominant matrix protein in enamel formation, contains a singular phosphorylation site at Serine 16 (S16) that greatly enhances AMELX's capacity to stabilize amorphous calcium phosphate (ACP) and inhibit its transformation to apatitic enamel crystals. To explore the potential role of AMELX phosphorylation in vivo, we developed a knock-in (KI) mouse model in which AMELX phosphorylation is prevented by substituting S16 with Ala (A). As anticipated, AMELXS16A KI mice displayed a severe phenotype characterized by weak hypoplastic enamel, absence of enamel rods, extensive ectopic calcifications, a greater rate of ACP transformation to apatitic crystals, and progressive cell pathology in enamel-forming cells (ameloblasts). In the present investigation, our focus was on understanding the mechanisms of action of phosphorylated AMELX in amelogenesis. We have hypothesized that the absence of AMELX phosphorylation would result in a loss of controlled mineralization during the secretory stage of amelogenesis, leading to an enhanced rate of enamel mineralization that causes enamel acidification due to excessive proton release. To test these hypotheses, we employed microcomputed tomography (µCT), colorimetric pH assessment, and Fourier Transform Infrared (FTIR) microspectroscopy of apical portions of mandibular incisors from 8-week old wildtype (WT) and KI mice. As hypothesized, µCT analyses demonstrated significantly higher rates of enamel mineral densification in KI mice during the secretory stage compared to the WT. Despite a greater rate of enamel densification, maximal KI enamel thickness increased at a significantly lower rate than that of the WT during the secretory stage of amelogenesis, reaching a thickness in mid-maturation that is approximately half that of the WT. pH assessments revealed a lower pH in secretory enamel in KI compared to WT mice, as hypothesized. FTIR findings further demonstrated that KI enamel is comprised of significantly greater amounts of acid phosphate compared to the WT, consistent with our pH assessments. Furthermore, FTIR microspectroscopy indicated a significantly higher mineral-to-organic ratio in KI enamel, as supported by µCT findings. Collectively, our current findings demonstrate that phosphorylated AMELX plays crucial mechanistic roles in regulating the rate of enamel mineral formation, and in maintaining physico-chemical homeostasis and the enamel growth pattern during early stages of amelogenesis.

Quantum Dichotomies and Coherent Thermodynamics beyond First-Order Asymptotics

We address the problem of exact and approximate transformation of quantum dichotomies in the asymptotic regime, i.e., the existence of a quantum channel E mapping ρ1⊗n into ρ2⊗Rnn with an error ϵn (measured by trace distance) and σ1⊗n into σ2⊗Rnn exactly, for a large number n. We derive second-order asymptotic expressions for the optimal transformation rate Rn in the small-, moderate-, and large-deviation error regimes, as well as the zero-error regime, for an arbitrary pair (ρ1,σ1) of initial states and a commuting pair (ρ2,σ2) of final states. We also prove that for σ1 and σ2 given by thermal Gibbs states, the derived optimal transformation rates in the first three regimes can be attained by thermal operations. This allows us, for the first time, to study the second-order asymptotics of thermodynamic state interconversion with fully general initial states that may have coherence between different energy eigenspaces. Thus, we discuss the optimal performance of thermodynamic protocols with coherent inputs and describe three novel resonance phenomena allowing one to significantly reduce transformation errors induced by finite-size effects. What is more, our result on quantum dichotomies can also be used to obtain, up to second-order asymptotic terms, optimal conversion rates between pure bipartite entangled states under local operations and classical communication. Published by the American Physical Society 2024

Effect of surfactants on the degree of polydispersity of a suspension of polystyrene latex spheres

The problem of satisfying the needs of the domestic market of the Russian Federation for creating domestic particle size standard reference materials in liquids to ensure uniformity in measurements of the granulometric composition of aerosols and powdery substances is considered. It is known that, under various conditions, monodisperse suspensions of polystyrene latex spheres can be synthesized, both monodisperse and polydisperse samples being obtainable. The effect of the composition and solubility of surfactants in a styrene-based water emulsion on the particle size of suspensions obtained as a result of emulsion polymerization, and their polydispersity, has been investigated. The metrological characteristics of polystyrene suspensions based on sodium, potassium, and lithium laureths synthesized in this study were determined using dynamic light scattering and laser diffraction techniques. It has been found that the size and degree of polydispersity of particles in suspensions based on lauric acid salts is primarily influenced by the solubility of the surfactant and the surface tension of the interfacial layer formed between styrene and water at the time of particle formation. The effect of the rate of reaction, as well as the concentration of surfactants, on the size and polydispersity of the synthesized particles, has been studied. It has been found that when potassium persulfate is used as the initiator in the reaction, particle size distributions are monodisperse for suspensions based on sodium or potassium laureate. The polydispersity degree of lithium laureate-based suspensions is approximately 1.5 to 2 times higher compared to other suspension samples. When azoisobutyronitrile is used as an initiator, all suspensions samples are monodisperse. It has been experimentally determined that the achievement of monodisperse samples is due to the polymer-monomer particle formation time, which is comparable to the monomer transformation rate. The results obtained will be utilized in the development and establishment of particle size standard reference materials for storage and reproduction of particle size values within a liquid medium.

Seawater intrusion effects on nitrogen cycling in the regulated Nakdong River Estuary, South Korea

Research on the impact of seawater intrusion on nitrogen (N) cycling in coastal estuarine ecosystems is crucial; however, there is still a lack of relevant research conducted under in-situ field conditions. The effects of elevated salinity on N cycling processes and microbiomes were examined in situ seawater intrusion experiments conducted from 2019 to 2021 in the Nakdong River Estuary (South Korea), where an estuarine dam regulates tidal hydrodynamics. After the opening of the Nakdong Estuary Dam (seawater intrusion event), the density difference between seawater and freshwater resulted in varying degrees of seawater trapping at topographically deep stations. Bottom-water oxygen conditions had been altered in normoxia, hypoxia, and weak hypoxia due to the different degrees of seawater trapping in 2019, 2020, and 2021, respectively. Denitrification mostly dominated the nitrate (NO3-) reduction process, except in 2020 after seawater intrusion. However, denitrification rates decreased because of reduced coupled nitrification after seawater intrusion due to the dissolved oxygen limitation in 2020. Dissimilatory nitrate reduction to ammonium (DNRA) rates immediately increased after seawater intrusion in 2020, replacing denitrification as the dominant pathway in the NO3- reduction process. The enhanced DNRA rate was mainly due to the abundant organic matter associated with seawater invasion and more reducing environment (maybe sulfide enhancement effects) under high seawater-trapping conditions. Denitrification increased in 2021 after seawater intrusion during weak hypoxia; however, DNRA did not change. Small seawater intrusion in 2019 caused no seawater trapping and overall normoxic condition, though a slight shift from denitrification to DNRA was observed. Metagenomic analysis revealed a decrease in overall denitrification-associated genes in response to seawater intrusion in 2019 and 2020, while DNRA-associated gene abundance increased. In 2021 after seawater intrusion, microbial gene abundance associated with denitrification increased, while that of DNRA did not change significantly. These changes in gene abundance align mostly with alterations in nitrogen transformation rates. In summary, ecological change effects in N cycling after the dam opening (N retention or release, that is, eutrophication deterioration or mitigation) depend on the degree of seawater intrusion and the underlying freshwater conditions, which constitute the extent of seawater-trapping.

Lithology-driven soil properties control of N2O production by ammonia oxidizers in subtropical forest soils

Lithology can strongly influence soil's physical and chemical properties, significantly affecting soil nitrogen (N) transformation rates. Ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and complete ammonia oxidizers (comammox Nitrospira) constitute the major producers of soil nitrous oxide (N2O), but the importance of different lithology on their relative contributions still poorly understood, especially in terms of newly discovered and widespread comammox. To address this knowledge gap, three nitrification inhibitors, acetylene (ammonia oxidizers inhibitor), 1-octyne (AOB inhibitor) and 3,4-dimethylpyrazole phosphate (DMPP) (both AOB and comammox inhibitor), were used to selectively inhibit the activity of different ammonia oxidation groups in order to discriminate their respective roles in N2O production in forest soils developed on different lithologies (limestone and clastic rock). The results showed that AOB dominated N2O production (63.5 ± 3.3 %) in limestone soils with ammonium amendment, followed by AOA (34.5 ± 7.6 %), while comammox contributed 1 % of total N2O production with N2O yield of 0.03 ± 0.04 %. Higher N2O production by AOB in limestone soils is associated with higher soil pH, exchangeable calcium/magnesium and lower short-range order iron/aluminum minerals. However, the N2O yield by comammox (0.12 ± 0.12 %) in clastic rock soils was comparable to that by AOA (0.15 ± 0.14 %) and AOB (0.20 ± 0.13 %). Based on the results of the correlation analysis, comammox in the clastic rock soils produce greater amounts of N2O is closely related to the higher soil organic carbon and available phosphorus. The present study provided evidence that the lithology-driven soil properties markedly affect the N2O production from different ammonia oxidizers.

The effect of retained austenite on rolling/sliding contact fatigue of high carbon steel

Rolling contact fatigue (RCF) is significantly influenced by retained austenite (RA). To study the impact of the RA on fatigue life and pit formation, a high carbon steel was tested with three different RA levels ranging from 5 % to 23 % (volume fraction). The variations of the RA with respect to the number of cycles and along the depth were inspected by X-ray diffraction (XRD) technique. The microstructures before and after RCF were characterized by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The majority of RA was transformed into martensite at an early stage (before 3 × 104 cycles) in both surface and subsurface. And the remaining small fraction of RA was transformed during the rest of the testing life, with a final content lower than 5 %. As the depth increased, the rate of RA transformation decreased. The specimen with the highest RA level of 23 % showed the shortest life. The longest RCF life was seen in the specimen with a medium RA level of 15 % due to the formation of the well-developed hardened layer, which helps resisting the pit formation. Based on these observations, it was suggested that a medium level of RA is beneficial for the improvement of the RCF life of the present high carbon steel. The combined effect of the hardness and the RA acts together on resistance to pit formation.

Enhanced deformation-induced FCC-HCP transformation of a metastable high-entropy alloy induced by a smaller grain size

This study reports the grain-size-dependent deformation-induced face-centered cubic (FCC)–hexagonal close-packed (HCP) transformation behavior of Fe49.5Mn30Co10Cr10C0.2Ti0.1V0.1Mo0.1 (at. %) high-entropy alloy in the medium grain size range (10–20 μm), their mechanical properties, and deformation mechanisms. The materials annealed at 900 °C for 1 h (A900-1) and 10 h (A900-10) showed a fully FCC, recrystallized microstructure with a larger grain size in the latter owing to grain growth during annealing. The A900-1 sample exhibited a larger strength–ductility balance and a higher strain hardening rate than the A900-10 sample. The A900-1 sample, with a larger number of grain boundary nucleation sites of the deformation-induced HCP phase, exhibited a higher HCP transformation rate than the A900-10 sample in the early stage of deformation below 10 % strain, whereas both materials showed similar HCP transformation rates at strain levels higher than 30 %. The emission of deformation-induced HCP plates in both neighboring grains from the same grain boundary (A900-1) and the activation of the deformation-induced HCP phase in a single grain and only dislocations in the neighboring grains (A900-10) suggest the importance of grain boundary stress in the observed phenomena. The observed additional mechanisms other than dislocation slip and deformation-induced HCP phase, that is, reverse FCC-HCP transformation, HCP {101‾2} twinning, and kink banding, could contribute to deformation accommodation and stress relaxation, thereby leading to the excellent ductility of the investigated materials.

Transformation of 6:6 PFPiA in the gut of Xenopus laevis: Synergistic effects of CYP450 enzymes and gut microflora

As a frequently detected per- and polyfluoroalkyl substance in the environment, 6:6 perfluoroalkylhypophosphinic acid (6:6 PFPiA) is vulnerable to transformation in the liver of organisms, but the transformation in gut is still unclear. This study investigates the molecular mechanisms of 6:6 PFPiA transformation in the gut of Xenopus laevis upon a 28-day exposure in water. Before Day 16, a notable correlation (p = 0.03) was observed between the transformation product (PFHxPA) and cytochrome P450 (CYP450) enzyme concentration in gut. This suggests that CYP450 enzymes played an important role in the transformation of 6:6 PFPiA in the gut, which was verified by an in vitro incubation with gut tissues, and supported by the molecular docking results of 6:6 PFPiA binding with CYP450 enzymes. From the day 16, the CYP450 concentration in gut decreased by 31.3 % due to the damage caused by 6:6 PFPiA, leading to a decrease in the transformation capacity in gut, but the transformation rate was stronger than in liver. This was in contrast with the in vitro experiment, where transformation was stronger in liver. In the mean time, the abundance of Bacteroidota in gut increased, which released hydrolytic enzyme and then could participate in the transformation as well. This study reveals the potential of the gut in metabolizing environmental pollutants, and provides profound insights into the potential health risks caused by 6:6 PFPiA in organisms.