Search Results (872)

Superior-type iron formations (IFs) represent a globally significant source of iron ore; yet, their origin remains a subject of ongoing debate. Early models proposed a continental weathering source for the iron, whereas later interpretations—mainly supported by positive europium (Eu) anomalies—favored a hydrothermal source. However, the hydrothermal model largely relies on REE systematics, and whether iron and REEs in Superior-type IFs share the same source remains uncertain. As iron isotopes directly trace the sources and fractionation history of iron, a spatial co-variation between Fe isotopes and Eu anomalies would shed new light on the iron source issue of IFs. In this study, we present new Fe isotope and REE data from the drill core WILDD004 at Wilgena Hill and integrate them with reported data for two additional drill cores: HKDD4 (Hawks Nest) and GWDD1 (Giffen Well). All three cores are stratigraphically equivalent to the Wilgena Hill Jaspilite Formation but span a lateral distance of ~100 km across the Gawler Craton, South Australia. While the Hawks Nest and Giffen Well samples exhibit both positive Eu anomalies and elevated δ⁵⁶Fe values, the Wilgena Hill samples show positive yet smaller Eu/Eu* (1.17–2.41) and negative δ⁵⁶Fe values (−0.60‰ to −1.63‰). The consistent presence of Eu anomalies and the systematic spatial correlation between δ⁵⁶Fe and Eu/Eu* across all three locations provide direct, Fe-based geochemical evidence for a hydrothermal source of iron in this Superior-type IF. Full article

Cobalt is an essential trace element involved in key biological processes. It serves most notably as a component of vitamin B₁₂ (cobalamin) and a regulator of erythropoiesis. While cobalt deficiency can lead to disorders such as megaloblastic anemia, excess cobalt poses toxicological risks to the thyroid, cardiovascular, and hematopoietic systems. In recent years, cobalt ions (Co²⁺) have gained attention for their ability to mimic hypoxia and promote angiogenesis. This represents a crucial mechanism for tissue regeneration. Cobalt mediates this effect mainly by stabilizing hypoxia-inducible factor 1α (HIF-1α) under normoxic conditions, thereby upregulating angiogenic genes, including VEGF, FGF, and EPO. Experimental studies—from cell culture to animal models—have demonstrated cobalt-induced enhancement of endothelial proliferation, migration, and microvascular formation. Emerging evidence also indicates that Co²⁺-stimulated macrophages secrete integrin-β1-rich exosomes. These exosomes enhance endothelial motility and tubulogenesis independently of VEGF. Furthermore, cobalt-modified biomaterials have been developed to deliver cobalt ions in a controlled manner. Examples include cobalt-doped β-tricalcium phosphate or bioactive glasses. These materials support both angiogenesis and osteogenesis.This review summarizes current findings on cobalt’s role in angiogenesis. The emphasis is on its potential in cobalt-based biomaterials for tissue engineering and regenerative medicine. Full article

The report of the first room-temperature, ambient-pressure superconductivity in copper-doped lead apatite Pb_10−xCu_x(PO₄)₆O has attracted lots of attention. However, subsequent studies revealed the presence of numerous impurity phases in the polycrystalline sample, and the sharp superconducting-like transition is not due to a superconducting transition but most likely due to a reduction in resistivity caused by the first-order structural phase transition of Cu₂S at around 385 K from the β phase at high temperature to the γ phase at low temperature. Before now, only bulk measurements have been performed on a Pb_10−xCu_x(PO₄)₆O powder sample, which could be affected by the impurity phases, masking the intrinsic properties of Pb_10−xCu_x(PO₄)₆O. In this study, ³¹P and ^63/65Cu nuclear magnetic resonance (NMR) measurements have been performed on a Pb_10−xCu_x(PO₄)₆O powder sample to investigate its physical properties from a microscopic point of view. Our NMR data evidence the non-magnetic insulating nature of Pb_10−xCu_x(PO₄)₆O without any trace of electron correlation effects. Furthermore, the ^63/65Cu NMR results suggest that no copper or very little copper is substituted for Pb in Pb₁₀(PO₄)₆O prepared by sintering Pb₂SO₅ and Cu₃P. Full article

Indonesia’s dependence on fossil fuel exports, particularly coal and crude oil, presents a dual challenge: sustaining economic growth while addressing rising CO₂ emissions. Despite significant attention to domestic energy consumption, the environmental implications of export activities remain underexplored. This study examines the dynamic relationship between energy exports, crude oil prices, and CO₂ emissions in Indonesia using a Vector Autoregressive (VAR) model with annual data from 2002 to 2022. The analysis incorporates Impulse Response Functions (IRFs) and Forecast Error Variance Decomposition (FEVD) to trace short- and long-term interactions among variables. Findings reveal that coal exports are strongly persistent and positively linked to past emission levels, while oil exports respond negatively to both coal and emission shocks—suggesting internal trade-offs. CO₂ emissions are primarily self-driven yet increasingly influenced by oil export fluctuations over time. Crude oil prices, in contrast, have limited impact on domestic emissions. This study contributes a novel export-based perspective to Indonesia’s emission profile and demonstrates the value of dynamic modeling in policy analysis. Results underscore the importance of integrated strategies that balance trade objectives with climate commitments, offering evidence-based insights for refining Indonesia’s nationally determined contributions (NDCs) and sustainable energy policies. Full article

Subsurface drainage and biochar application are conventional measures for improving saline–alkali soils. However, their combined effects on the fate of nitrogen (N) fertilizers remain unclear. This study investigated the combined effects of subsurface drainage and biochar amendment on the fate of nitrogen (N) in coastal saline–alkali soils, where these conventional remediation measures’ combined impacts on fertilizer N dynamics remain seldom studied. Using ¹⁵N-labeled urea tracing in an alfalfa–soil system, we examined how different drainage spacings (0, 6, 12, and 18 m) and biochar application rates (5, 10, and 15 t/ha) influenced N distribution patterns. Results demonstrated decreasing in drainage spacing and increasing in biochar application; these treatments enhanced ¹⁵N use efficiency on three harvested crops. Drainage showed more sustained effects than biochar. Notably, the combination of 6 m drainage spacing with 15 t/ha biochar application achieved optimal performance of ¹⁵N use, showing N utilization efficiency of 46.0% that significantly compared with most other treatments (p < 0.05). ¹⁵N mass balance analysis revealed that the plant absorption, the soil residual and the loss of applied N accounted for 21.6–46.0%, 38.6–67.5% and 8.5–18.1%, respectively. These findings provide important insights for optimizing nitrogen management in coastal saline–alkali agriculture, demonstrating that strategic integration of subsurface drainage (6 m spacing) with biochar amendment (15 t/ha) can maximize N use efficiency, although potential N losses warrant consideration in field applications. Full article

Be stars are characterized by the presence of a circumstellar Keplerian disk formed from material ejected from the rapidly rotating stellar surface. This article presents recent observational and theoretical progress on two central aspects of this phenomenon: the mechanisms driving mass loss, and the fate of the ejected material. Using simultaneous TESS photometry and ground-based spectroscopy, we examine the short-term variability associated with discrete mass ejection events, or “flickers”, and review strong evidence linking them to pulsational activity near the stellar surface. Complementary 3D hydrodynamic simulations reproduce key observational signatures and establish that disk formation requires compact and asymmetric ejection sites with sufficient angular momentum to overcome re-accretion. In systems with binary companions, new high-resolution simulations resolve the outer disk for the first time and identify five dynamically distinct regions, including a circumsecondary disk and a circumbinary spiral outflow. Together, these results provide a coherent framework that traces the full life cycle of disk material from pulsation-driven ejection near the stellar surface to its final destination, whether re-accreted by the companion or lost from the system entirely. Full article

Since 1957, the near-Earth population of trackable space objects has grown in number to over 36,000. Of these 36,000+ trackable objects now in low Earth orbit, just a few thousand are working spacecraft. The rest are Earth-orbiting objects which are no longer operational and are considered to be space junk. Because this junk can no longer receive maneuvering commands from its Earth-based owners, the survivability of other spacecraft traveling through or operating in Earth orbit can be jeopardized by the impacts of any number of pieces of this space junk, whose origins can usually be traced back to defunct satellites. As a result, a major design parameter for Earth-orbiting spacecraft is the possibility of such high-speed impacts and the damage they can cause. Furthermore, several private companies are now launching several thousand spacecraft into Earth orbit, many of which are satellites built for communication purposes. Other satellites have been launched to expand the reach of the World Wide Web and to provide better tools for disaster management. Two questions quickly become evident, namely, what is the beneficial purpose of these large satellite constellations, and what are some of the deleterious consequences of their proliferation? Numerous topics related to space debris will be discussed in this paper, including issues in space law that concern the growing problem of orbital debris. In the end, several areas of concern will be noted that are vital to the continuing presence of humans in near-Earth space and must be addressed as the near-Earth orbital environment becomes more congested and space traffic management becomes more difficult. Full article

Rationalist thought and positivism, as observed in various Eastern societies, led to significant upheavals in Turkish society concerning entrenched beliefs about the relationship between humanity and the world. These upheavals can be traced through the modernization efforts of the Tanzimat (Reorganization) period (between 1839 and 1896, the period of modernization and renewal in the Ottoman Empire). Although the initial generation of writers and poets during this period did not overtly renounce their connections to tradition, by the onset of the 20th century, a critical perspective towards traditional and religious content in both poetry and novels became evident. In its formative stages, Turkish socialist novels, which evolved under the influence of Russian socialism, were shaped by the classical Marxist interpretation of religion. Consequently, the socialist realist Turkish novel developed a more original character and distanced itself from stereotypical judgments. Kemal Tahir, who occupies a significant role in the realm of Turkish socialist novels, offers insights into the position and function of faith within society, as he transitioned from the classical Marxist paradigm towards a more original understanding. This study investigates the alterations in religious approaches during the Westernization process within Turkish literature and assesses the reflections of this transformation in the novels of Kemal Tahir (1910–1973), one of the preeminent figures of the socialist realist Turkish novel. Full article

Zinc is an essential trace element involved in diverse physiological processes in humans. Zinc deficiency is common in patients with chronic kidney disease (CKD), including those undergoing hemodialysis. This narrative review synthesizes both experimental and clinical findings on zinc status in CKD patients. Literature was primarily retrieved from PubMed using the keywords “zinc” AND (“CKD” OR “hemodialysis”) AND at least one of the following: “cardiovascular disease (CVD)”, “vascular calcification”, “anemia”, “blood pressure”, OR “infection”. In vitro, studies have shown that zinc suppressed phosphate-induced vascular calcification while zinc deficiency directly promoted calcification. Clinically, serum zinc levels were positively correlated with calcification propensity in patients with CKD. In vivo zinc deficiency has been implicated in elevated blood pressure, Moreover, zinc supplementation enhanced erythropoiesis and improved responsiveness to erythropoiesis-stimulating agents in both animal models and humans. We recently reported that low serum zinc levels are associated with increased mortality in hemodialysis patients with hypoalbuminemia. Previous randomized controlled trials (RCTs) suggest a daily dose of approximately 45 mg of zinc for 2 months mitigates inflammation, oxidative stress, and malnutrition in patients undergoing hemodialysis. Emerging evidence suggests that vascular calcification, hypertension, and renal anemia are newly recognized features of zinc deficiency and are established risk factors for CKD progression, CVD, and mortality. However, the impact of zinc supplementation on these clinical outcomes remains inconclusive. Further RCTs are required to establish zinc supplementation as an effective therapeutic strategy for improving various outcomes in patients with CKD including hemodialysis. Full article

Geothermal systems play a crucial role in understanding Earth’s heat dynamics. The Yunkai Uplift in southern China exemplifies a geothermally rich region characterized by ancient lithologies and high heat flow. This study investigates the geochemical characteristics of geothermal waters in the Yunkai Uplift. Both geothermal and non-thermal water samples were collected along the Xinyi–Lianjiang (XL) Fault Zone and the Cenxi–Luchuan (CL) Fault Zone flanking the core of the Yunkai Mountains. Analytical techniques were applied to examine major ions, trace elements, and dissolved CO₂ and H₂, as well as isotopic characteristics of O, H, Sr, C, and He in water samples, allowing for an investigation of geothermal reservoir temperatures, circulation depths, and mixing processes. The findings indicate that most geothermal waters are influenced by water–rock interactions primarily dominated by granites. The region’s diverse lithologies, change from ancient Caledonian granites and medium–high-grade metamorphic rocks in the central hinterland (XL Fault Zone) to low-grade metamorphic rocks and sedimentary rocks in the western margin (CL Fault Zone). The chemical compositions of geothermal waters are influenced through mixing contacts between diverse rocks of varying ages, leading to distinct geochemical characteristics. Notably, δ¹³C_CO2 values reveal that while some samples exhibit significant contributions from metamorphic CO₂ sources, others are characterized by organic CO₂ origins. Regional heat flow results from the upwelling of mantle magma, supplemented by radioactive heat generated from crustal granites. Isotopic evidence from δ²H and δ¹⁸O indicates that the geothermal waters originate from atmospheric sources, recharged by precipitation in the northern Yunkai Mountains. After infiltrating to specific depths, meteoric waters are heated to temperatures ranging from about 76.4 °C to 178.5 °C before ascending through the XL and CL Fault Zones under buoyancy forces. During their upward migration, geothermal waters undergo significant mixing with cold groundwater (54–92%) in shallow strata. As part of the western boundary of the Yunkai Uplift, the CL Fault Zone may extend deeper into the crust or even interact with the upper mantle but exhibits weaker hydrothermal activities than the XL Fault Zone. The XL Fault Zone, however, is enriched with highly heat-generating granites, is subjected more to both the thermal and mechanical influences of upwelling mantle magma, resulting in a higher heat flow and tension effect, and is more conducive to the formation of geothermal waters. Our findings underscore the role of geotectonic processes, lithological variation, and fault zone activity in shaping the genesis and evolution of geothermal waters in the Yunkai Uplift. Full article

This paper explores how the interpretations of the phrase “tian you qi zhong 天誘其衷” in the Zuozhuan 左傳 (The Zuo Commentary) have changed over time. These changes reflect early Confucian perspectives on the relationship between Heaven and humanity. By examining the polysemous terms (you 誘 and zhong 衷) and by comparing transmitted texts with excavated manuscripts (e.g., Guodian 郭店, Shangbo 上博, and Tsinghua corpora), the paper demonstrates a vital dilemma in early Chinese philosophy: whether Heaven endows moral qualities or simply awakens the innate dispositions of human beings. The paper traces the moralization of tian 天 (Heaven) from the Shang 商 dynasty’s theocentric worldview to the Zhou’s 周 focus on ethical responsibility, showing how the Zuozhuan bridges archaic religious beliefs and emerging Confucian humanism. Traditional commentaries read tian you qi zhong as Heaven “bestowing goodness” or “guiding moral intention,” while the manuscript evidence suggests that the phrase actually meant Heaven “descending its heart or will” to attune human affairs to the cosmos. Han exegetes redefined the term you as pedagogical guidance due to Confucianism’s growing emphasis on self-cultivation. By contextualizing the phrase at a larger backdrop of discussions of the Mandate of Heaven (tianming 天命) and moral cultivation, the study contends that early Confucians transformed tian from a deity figure to a moral principle dwelling in the human capacity, integrating religious reverence and ethical emancipation. This interdisciplinary approach studies ongoing scholarly discussions on the interrelationship between religion, ethics, and philosophy in early China. Full article

Osteoarthritis (OA) is a prevalent and disabling joint disorder characterized by progressive cartilage degradation, subchondral bone changes, synovial inflammation, and chronic pain. While traditionally attributed to mechanical and age-related factors, increasing attention has been directed toward the role of nutritional components in disease modulation. This article critically examines the emerging role of three essential trace elements, zinc, copper, and selenium, in the pathophysiology of OA. These micronutrients are fundamental to antioxidant defense, immune modulation, and extracellular matrix (ECM) integrity. Altered systemic or local levels of zinc, copper, and selenium have been associated with oxidative stress, inflammation, and dysregulated cartilage metabolism in OA. Drawing on clinical studies, in vivo and in vitro experimental models, and population-based data, we synthesize evidence on trace element status in OA patients, mechanistic pathways, and therapeutic potential, including emerging nanomedicine strategies that enhance the targeted delivery and therapeutic efficacy of trace elements in joint tissues. This review highlights the need for integrated trace element profiling in OA research and clinical care and supports the exploration of targeted nutritional interventions in OA prevention and management. Full article

Effective postoperative pain management remains a major clinical challenge in spinal surgery, with poorly controlled pain affecting up to 50% of patients and contributing to delayed mobilization, prolonged hospitalization, and risk of chronic postsurgical pain. This review synthesizes current and emerging strategies in postoperative spinal pain management, tracing the evolution from opioid-centric paradigms to individualized, multimodal approaches. Multimodal analgesia (MMA) has become the cornerstone of contemporary care, combining pharmacologic agents, such as non-steroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and gabapentinoids, with regional anesthesia techniques, including erector spinae plane blocks and liposomal bupivacaine. Adjunctive nonpharmacologic modalities like early mobilization, cognitive behavioral therapy, and mindfulness-based interventions further optimize recovery and address the biopsychosocial dimensions of pain. For patients with refractory pain, neuromodulation techniques such as spinal cord and peripheral nerve stimulation offer promising results. Advances in artificial intelligence (AI), biomarker discovery, and nanotechnology are poised to enhance personalized pain protocols through predictive modeling and targeted drug delivery. Enhanced recovery after surgery protocols, which integrate many of these strategies, have been shown to reduce opioid use, hospital length of stay, and complication rates. Nevertheless, variability in implementation and the need for individualized protocols remain key challenges. Future directions include AI-guided analytics, regenerative therapies, and expanded research on long-term functional outcomes. This review provides an evidence-based framework for pain control following spinal surgery, emphasizing integration of multimodal and innovative approaches tailored to diverse patient populations. Full article

The aim of this study was to test the Implicit Prosody Hypothesis using a reading corpus, i.e., a text without experimental manipulation labelled with eye-tracking parameters. For this purpose, a bilingual Croatian–English reading corpus was analysed. In prosodic terms, Croatian and English are at the opposite ends of the spectrum: English is considered a time-framed language, while Croatian is a syllable-framed language. This difference served as a kind of experimental control in this study on natural reading. The results show that readers’ eyes lingered more on stressed syllables than on the arrangement of stressed and unstressed syllables for both languages. This is especially pronounced for English, a language with greater differences in the duration of stressed and unstressed syllables. This study provides indirect evidence in favour of the Implicit Prosody Hypothesis, i.e., the idea that readers are guided by their inner voice with its suprasegmental features when reading silently. The differences between the languages can be traced back to the typological differences in stress in English and Croatian. Full article

Amelanotic melanocytic nevi of the oral cavity are uncommon lesions that often present a diagnostic challenge for clinicians, primarily due to their nonspecific clinical appearance and the broad spectrum of possible differential diagnoses. These lesions can mimic a variety of benign and malignant conditions, requiring precise histopathological confirmation. The primary objective of this article is to present a comprehensive case report—tracing the course from initial presentation through diagnostic workup to final diagnosis—and to provide an overview of the current literature on oral amelanotic melanocytic nevi. We report the case of a 27-year-old female who presented with a small, exophytic mass located in the anterior mandibular gingival region. The lesion was asymptomatic and lacked pigmentation, adding to the diagnostic uncertainty. A range of differential diagnoses was considered, including pyogenic granuloma, peripheral ossifying fibroma, and squamous cell carcinoma. Due to the lesion’s limited size and accessibility, an excisional biopsy was performed under local anesthesia. Histopathological examination revealed an amelanotic melanocytic nevus, a rare variant characterized by the absence of melanin pigment, further complicating the clinical impression. The diagnosis was confirmed through immunohistochemical staining, which demonstrated melanocytic markers consistent with a nevus. The patient was followed up with for six months postoperatively, with no evidence of recurrence or malignant transformation. This case highlights the critical role of biopsy in achieving a definitive diagnosis, especially in lesions with atypical clinical presentations. It also underscores the importance of considering amelanotic melanocytic nevi in the differential diagnosis of nonpigmented oral lesions, as well as maintaining vigilance regarding the rare possibility of amelanotic melanoma. Full article