Significant Extension Research Articles

Properties of generalized polyhedral convex multifunctions

This paper presents a study of generalized polyhedral convexity under basic operations on multifunctions. We address the preservation of generalized polyhedral convexity under sums and compositions of multifunctions, the domains and ranges of generalized polyhedral convex multifunctions, and the direct and inverse images of sets under such mappings. Then we explore the class of optimal value functions defined by a generalized polyhedral convex objective function and a generalized polyhedral convex constrained mapping. The new results provide a framework for representing the relative interior of the graph of a generalized polyhedral convex multifunction in terms of the relative interiors of its domain and mapping values in locally convex topological vector spaces. Among the new results in this paper is a significant extension of a result by Bonnans and Shapiro on the domain of generalized polyhedral convex multifunctions from Banach spaces to locally convex topological vector spaces.

Alteration in sB7-H4 Serum Levels and Placental Biomarker Expression after Therapeutic Plasma Exchange in Early-Onset Preeclampsia Patients

Therapeutic plasma exchange (TPE) is a widely used treatment for numerous diseases including pregnancy-related conditions. Our prior study on 20 early-onset preeclampsia patients undergoing TPE revealed a significant extension in pregnancy duration and reduced serum levels of sFlt-1, sFlt-1/PlGF, and sEndoglin. Here, we investigated the impact of TPE on serum sB7-H4, an immunological checkpoint molecule, and placental proteins (Flt-1, Eng, B7-H4, iNOS, TNF-α) in TPE-treated early-onset preeclampsia patients (N = 12, 23 + 2–28 + 5 weeks), conventionally treated counterparts (N = 12, 23 + 5–30 weeks), and gestational age-matched controls (N = 8, 22 + 4–31 + 6 weeks). Immunoblotting, ELISA, and co-immunohistochemistry were used for biomarker analysis, including placental inflammation factors (iNOS, TNF-α). The results showed that TPE extended pregnancy by a median of 6.5 days in this cohort of early-onset preeclampsia. Serum sB7-H4, sFlt-1, and sEndoglin levels decreased, along with reduced expression of their membrane-bound proteins in placental tissue upon TPE treatment. Moreover, TPE-treated patients displayed reduced placental inflammation compared to preeclampsia patients receiving standard-of-care treatment. In conclusion, TPE may improve pregnancy outcomes in early-onset preeclampsia by lowering circulating levels of sB7-H4, sFlt-1, and sEndoglin, as well as reducing placental inflammation. This translational approach holds promise for enhancing placental function and extending gestation in high-risk pregnancies including very preterm PE or HELLP cases.

Enhanced Antimicrobial and Degradable Properties of Silver Nanoparticles‐Reinforced Chitosan‐Indian Gooseberry Films for Sustainable Food Packaging

AbstractThis study focuses on creating a biodegradable film composed of chitosan, Indian Gooseberry (IG) extract, and silver nanoparticles (AgNPs), designed to enhance antimicrobial properties and improve food preservation. The presence of AgNPs and IG extract not only dramatically exhibits 99% efficiency in the antimicrobial activity against Staphylococcus aureus (ATCC 6538P), but also achieves this within a remarkably short time interval of ≈20 min. This potent antimicrobial action is attributed to the synergistic effect between the bioactive compounds in the IG extract and the nanoscale silver particles, which together create a highly hostile environment for microbial growth. Moreover, this synergy contributes to 313.94% water vapor transmittance rate and the complete biodegradability of the composite film (93.42% at the end of the second month), ensuring that it leaves no harmful residues in the environment post‐use. The reinforced film exhibits improved hydrophobicity (55.43%), which is crucial for protecting food products from moisture and extending their shelf life. Specifically, the film has been tested as a packaging material for bread, showing a significant extension in shelf life by effectively preventing mold growth and retaining freshness for an extended period (14 days).

Unraveling the ion transport through top and wall coated polyelectrolyte membrane pores

Polyelectrolyte-based nanofiltration membranes are obtained through a layer-by-layer sequential deposition of oppositely charged polyelectrolytes (PEs) onto a porous support structure. The resulting polyelectrolyte membrane offers tailored salt rejections for nanofiltration applications. However, little is known about the exact location of the deposited PEs on top or inside a membrane pore. Also, scarce information is available on the contribution of the different potential PE locations that affect the salt rejection of the overall membrane. Hence, research challenges, such as the influence of (a) an adsorbed PE layer inside the support membrane or (b) the bridging of the original pores and the position of the bridging layer, can only be unraveled through rigorous simulations. We present a significant extension of our previously published model into a two-dimensional modeling framework pEnPEnS (pressure p driven transport through n electrolyte layers En, n polyelectrolyte layers PEn, and the support structure S) capable of addressing the selective layer additionally formed on the walls of the support capillary structure. The model solves a set of two-dimensional nonlinear Extended Nernst-Planck-Poisson and Navier-Stokes-Brinkman equations, enabling the prediction of ionic rejections from the top coating, wall coating, and a PE bridging forming inside the capillary. The proposed model framework systematically identifies and quantifies the influence of the capillary coating beneath the top layer on NaCl rejection and addresses the challenge of improving rejection rates. The model reveals that PEs deposited inside the support structure contribute significantly to NaCl rejection. It enables the predictions of differences in the rejection rates depending on the location of the PE coating, the diameter of the support capillary, and the transmembrane pressure. The model gives insight into PE bridging forming inside the support capillary and explains how its position and fixed charge density change ion rejection rates. As such, the model unravels insightful details on the rejection characteristics of coated capillaries, making it a powerful tool for designing polyelectrolyte membranes.

Efficacy of dexmedetomidine as an adjuvant in transverse abdominal plane blocks for cesarean section pain management: A systematic review and meta-analysis

Postoperative pain management is a key component of care for women undergoing cesarean section. Although the use of dexmedetomidine (DMD) as an adjuvant to local anesthetics in transverse abdominal plane (TAP) blocks has been investigated, its conclusive evidence on its efficacy and safety remains unclear. A standardized data extraction form, under the guidance of the PRISMA protocol, was devised for selecting relevant studies across eight databases, without restrictions on the publication period. In most of the eight studies reviewed, the group receiving DMD demonstrated a significant extension of the duration of analgesia compared to the control group [mean difference (MD) = -3.37 hours, 95% confidence interval (CI) = -6.10 to -0.65 hours, Z = 2.43, P = 0.02]. The DMD group also showed a significant decrease in Visual Analogue Scale pain scores (MD = -1.38, 95% CI = -2.52 to -0.24, Z = 2.37, P = 0.02) in comparison to the control group. Nevertheless, significant heterogeneity was observed across the studies, potentially due to differences in study design, patient demographics, and dosing protocols, among other factors. The results of this meta-analysis indicate that DMD could be an effective adjuvant to local anesthetics in TAP blocks, potentially improving postoperative pain management and decreasing the need for additional analgesia. Nevertheless, the considerable heterogeneity among the studies warrants cautious interpretation of these results.

A boost or a redundancy? on the value of combination of androgen receptor signal inhibitor and PARP inhibitor for advanced prostate cancer

AbstractPoly (ADP-ribose) polymerase (PARP) inhibitor (PARPi), as a novel endocrine therapy, has been investigated in patients with metastatic castration-resistant prostate cancer (mCRPC) in recent years. Multiple large-scale clinical trials have consistently demonstrated that various PARP inhibitors, including olaparib, rucaparib, niraparib, and talazoparib, confer longer radiographic progression-free survival (rPFS) compared to new hormonal agents (NHA) in mCRPC patients with homologous recombination deficiency (HRD). Moreover, the incidence of grade 3 and above adverse events did not significantly increase. Additionally, when combined with androgen receptor signaling inhibitors (ARSI), olaparib, niraparib, and talazoparib have shown significant extension of rPFS but also an increased occurrence of serious adverse events in HRD-positive patients. Only PROpel yielded positive results among the homologous recombination repair (HRR) mutation negative population. Therefore, it remains uncertain whether ARSI-PARPi combination therapy should be considered as first-line treatment for mCRPC patients without HRR mutations. In this review article, we aim to elucidate the necessity and feasibility of combination therapy versus monotherapy specifically within the HRR mutant population while exploring its potential applicability to other non-HRR mutant subtypes. Furthermore, we conducted a comprehensive search on registered clinical trials at present to summarize the research progress of PARP inhibitors in prostate cancer patients at different disease stages.

A fossil pinnate palm leaf (Arecaceae, subfam. Arecoideae) from Island Lagoon, in the arid zone of South Australia

ABSTRACT Fossil pinnate palm leaves (Arecaceae, subfam. Arecoideae) are described from the Eocene or Miocene Island Lagoon fossil site near Woomera in the arid zone of South Australia. These leaves are described as a new species, Phoenicites insula-lacuna and shown to share morphological similarities to the extant genus Archontophoenix (subtr. Archontophoenicinae), endemic to eastern Australia. This fossil record constitutes a significant temporal and geographic range extension for Archontophoenicinae and likely Archontophoenix. The presence in Australia of Archontophoenicinae as early as the Eocene or more likely Miocene, is in accordance with molecular analyses that propose dispersal of this clade into Australia from New Guinea, with subsequent dispersal from Australia to New Caledonia and divergence of the Archontophoenix and Chambeyronia lineages during this interval of time. Previously reported co-occurring myrtaceous woody fruits from Island Lagoon and proximal-coeval silcrete floras previously referred to Angophora, Callistemon, Eucalyptus, Melaleuca and fossils of other sclerophyllous taxa such as Banksia are consistent with this palm being part of a landscape mosaic with riparian rainforest that included mesic plants growing within wider sclerophyllous forest or woodland vegetation comparable to the eastern coastal zone of modern-day Australia and the modern range of Archontophoenix.

Multireference calculations on bond dissociation and biradical polycyclic aromatic hydrocarbons as guidance for fractional occupation number weighted density analysis in DFT calculations

This study explores open-shell biradical and polyradical molecular compounds based on extended multireference (MR) methods (MR-configuration interaction with singles and doubles (CISD) and MR-averaged quadratic coupled cluster (AQCC) approach) using the numbers of unpaired densities NU. These results were used to guide the analysis of the fractional occupation number weighted density (FOD) calculated within the finite temperature (FT) density functional theory (DFT) approach. As critical test examples, the dissociation of carbon–carbon (CC) single, double and triple bonds and a benchmark set of polycyclic aromatic hydrocarbons (PAHs) have been chosen. By examining single, double, and triple bond dissociations, we demonstrate the utility and accuracy but also limitations of the FOD analysis for describing these dissociation processes. In significant extension of previous work (Phys Chem Chem Phys 25: 27380–27393), the assessment of FOD applications for different classes of DFT functionals was performed examining the range-separated functionals ωB97XD, ωB97M-V, CAM-B3LYP, LC-ωPBE, and MN12-SX, the hybrid (M06-2X) functional and the double hybrid (B2P-LYP) functional. In all cases, strong correlations between NFOD and NU values are found. The major task was to develop a new linear regression formula for range-separated functionals allowing a convenient determination of the optimal electronic temperature Tel for the FT-DFT calculation. We also established an optimal temperature for the semiempirical extended tight-binding GFN2-xTB method. These findings significantly broaden the applicability of FOD analysis across various DFT functionals and semiempirical methods.

Reserve capacity and vertical extension potential in steel framed buildings

Reusing existing buildings is key in transitioning to a circular economy and meeting associated decarbonisation targets. Many adaptive reuse strategies, including vertical extensions, result in increased loads that are required to be resisted by reserve structural capacity and/or strengthening. Previous work identifies structural underutilisation within existing buildings and suggests numerous sources of this. However, understanding of associated contributions to reserve capacity and how this influences a building’s ability to be extended is limited. To address this, 11 scenarios, each modelling a different source of underutilisation, have been developed and applied in the design and reappraisal of 11,252 hypothetical steel framed office buildings. An average reserve capacity of 10% is found in optimal Eurocode designs, rising to around 20% for British Standards and over 30% in the conservative or defensive application of Eurocodes. Office to residential conversions are shown to unlock an average reserve capacity of more than 20%. Across the 11 scenarios, between 9% and 89% of considered cases are shown to be extendable without the need for strengthening. This demonstrates potentially significant extension potential within steel framed buildings, but that this varies with frame configuration, design/appraisal approach, and the extension’s use and structural material.

Stochasticity in Dietary Restriction-Mediated Lifespan Outcomes in Drosophila.

Dietary restriction (DR) is widely considered to be one of the most potent approaches to extend healthy lifespan across various species, yet it has become increasingly apparent that DR-mediated longevity is influenced by biological and non-biological factors. We propose that current priorities in the field should include understanding the relative contributions of these factors to elucidate the mechanisms underlying the beneficial effects of DR. Our work conducted in two laboratories, represents an attempt to unify DR protocols in Drosophila and to investigate the stochastic effects of DR. Across 64 pairs of survival data (DR/ad libitum, or AL), we find that DR does not universally extend lifespan. Specifically, we observed that DR conferred a significant lifespan extension in only 26.7% (17/64) of pairs. Our pooled data show that the overall lifespan difference between DR and AL groups is statistically significant, but the median lifespan increase under DR (7.1%) is small. The effects of DR were overshadowed by stochastic factors and genotype. Future research efforts directed toward gaining a comprehensive understanding of DR-dependent mechanisms should focus on unraveling the interactions between genetic and environmental factors. This is essential for developing personalized healthspan-extending interventions and optimizing dietary recommendations for individual genetic profiles.

Twenty-eight new and significant departmental reptile records for Paraguay

Twenty-eight new distribution records are reported for twenty-seven species of Paraguayan reptiles. Ten of these species are considered threatened at the national level (6 EN, 2 VU, 2 DD). Nineteen new departmental records are documented: Phrynops hilarii (Chelidae) in Misiones department; Homonota marthae, Phyllopezus przewalskii (Phyllodactylidae), Philodryas baroni and P. psammophidea (Colubridae) in Presidente Hayes department; Teius oculatus (Teiidae), Cercosaura schreibersii (Gymnophthalmidae), Ophiodes intermedius (Diploglossidae), Amphisbaena mertensii (Amphisbaenidae), Boiruna maculata and Philodryas aestiva (Colubridae) in Caazapá department; Amphisbaena alba (Amphisbaenidae) in Caaguazú and Cordillera departments; Bothrops moojeni (Viperidae), Eunectes notaeus (Boidae), Helicops leopardinus and Hydrodynastes gigas (Colubridae) in Guairá department; Apostolepis dimidiata, Atractus paraguayensis and Mussurana bicolor (Colubridae) in Itapúa department; and Epicrates crassus (Boidae) and Phalotris nigirilatus (Colubridae) in Concepción department. Significant range extensions of threatened or poorly-known species are also documented: The known distribution of the Endangered Salvator duseni (Teiidae) is extended 128.5 km to the east within Canindeyú department; that of the Vulnerable Boa occidentalis is extended 109.2 km to the southwest within Boquerón department; that of the Vulnerable Epicrates alvarezi (Boidae) is extended 136.6 km to the west within Boquerón department and 172.4 km to the northeast into Alto Paraguay department; that of Caiman yacare (Alligatoridae) is extended 132 km west within Boquerón department to the northern reaches of the Pilcomayo River. We also document an additional specimen of the rare Philodryas agassizii (Colubridae) and confirmation of the occurrence of the disputed form Phalotris “punctatus” in Paraguay.

User experience of neighbourhood greenspace and perceived impact on health and wellbeing: the case of an urban extension to a ‘Healthy New Town’ in England

ABSTRACT Recognising the provision of public greenspace in urban areas as a key tool to supporting health and wellbeing, the UK government has committed to ensuring that, by 2043, all citizens can reach greenspace within 15 minutes from their homes. However, it is increasingly acknowledged that simply providing access to greenspace may not be enough to ensure that positive benefits are realised. Characteristics including their accessibility, size, aesthetics, features, condition and safety can all distinguish between greenspaces that encourage visitation and those that are uninviting. This paper reports a neighbourhood-level study of the residential development of Kingsmere, which forms a significant urban extension to Bicester, England, and was developed as part of the government-funded ‘Healthy New Town’ programme. A cross-sectional survey, including follow-up interviews, was conducted to investigate residents’ use of different types of greenspace, satisfaction, and the perceived impact on personal health and wellbeing. Findings reveal that the provision of a variety of greenspaces within a 15-20-minute walk of homes has been effective in terms of use and satisfaction but that attention to access within sites, perceived safety, cleanliness and maintenance are important factors that could encourage greater use and enhance user satisfaction.

Optimising resource-constrained fleet selective maintenance with asynchronous maintenance breaks

This paper offers a novel and significant extension of the Fleet Selective Maintenance Problem (FSMP) by considering asynchronous maintenance breaks and resource-constrained maintenance planning. This constitutes a significant shift from the conventional focus on synchronous breaks for the FSMP formulated to plan maintenance for fleets of mission-critical systems. This paper establishes a theoretical link between the Selective Maintenance Problem (SMP) and the Resource Constrained Project Scheduling Problem (RCPSP). The proposed FSMP formulation for asynchronous breaks is more general and versatile in adapting to a broad spectrum of operational constraints and resource scarcities. Numerical experiments are conducted that highlights the trade-offs between the timing and quality levels of maintenance activities and the consumption of resources that maintenance planners can make to obtain the best system performance for the budget and maintenance windows available.

Stochasticity in Dietary Restriction-Mediated Lifespan Outcomes in Drosophila.

Dietary restriction (DR) is widely considered to be one of the most potent approaches to extend healthy lifespan across various species, yet it has become increasingly apparent that DR-mediated longevity is influenced by biological and non-biological factors. We propose that current priorities in the field should include understanding the relative contributions of these factors to elucidate the mechanisms underlying the beneficial effects of DR. Our work conducted in two laboratories, represents an attempt to unify DR protocols in Drosophila and to investigate the stochastic effects of DR. Across 64 pairs of survival data (DR/ad libitum, or AL), we find that DR does not universally extend lifespan. Specifically, we observed that DR conferred a significant lifespan extension in only 26.7% (17/64) of pairs. Our pooled data show that the overall lifespan difference between DR and AL groups is statistically significant, but the median lifespan increase under DR (7.1%) is small. The effects of DR were overshadowed by stochastic factors and genotype. Future research efforts directed toward gaining a comprehensive understanding of DR-dependent mechanisms should focus on unraveling the interactions between genetic and environmental factors. This is essential for developing personalized healthspan-extending interventions and optimizing dietary recommendations for individual genetic profiles.

Spatiotemporal dynamics and transformation of the Parana State coastline: A 34-year analysis using RS, GIS, and machine learning

The coastal zone is a critical and vibrant area within coastal cities. Analyzing the changes in the coastal zone of Parana State helps determine the spatiotemporal evolution patterns and driving forces of this region, providing guidance for resource protection and utilization. This study employs remote sensing (RS), Geographic Information System (GIS), and Machine Learning techniques, using Landsat data sets with eight distinct scenes from 1990 to 2024, to extract and analyze the coastline. Specifically, methodologies such as Shoreline Extraction, the Coastline Diversity Index (CDI), and the Coastline Utilization Index (CUI) were applied to assess the coastline's characteristics. The spatiotemporal characteristics of the coastline development in Parana are meticulously examined to ensure accuracy. The findings reveal that: 1) Over the past 34 years, the coastline of Parana State has shown a consistent increasing trend. Natural coastlines have been declining by 45% annually, while artificial coastlines have been increasing by approximately 55% annually. 2) The nature of the shoreline is transitioning from natural to sea-reclamation, engineering-enhanced, and degraded forest. 3) The coastline changes have occurred in three phases: The Built-up Land phase, the Port Petrochemical phase, and the Reducing Coastal Erosion phase. Significant shoreline extension is observed near both biological and ecological coasts. 4) The primary factors influencing the coastline alterations in Parana State include natural forces, human activities, and regional policies. These insights into the spatiotemporal dynamics of the Parana coastline can inform better coastal management and conservation strategies.

A multifunctional targeted nano-delivery system with radiosensitization and immune activation in glioblastoma

Glioblastoma (GBM), the most common primary brain malignancy in adults, is notoriously difficult to treat due to several factors: tendency to be radiation resistant, the presence of the blood brain barrier (BBB) which limits drug delivery and immune-privileged status which hampers effective immune responses. Traditionally, high-dose irradiation (8 Gy) is known to effectively enhance anti-tumor immune responses, but its application is limited by the risk of severe brain damage. Currently, conventional dose segmentation (2 Gy) is the standard radiotherapy method, which does not fully exploit the potential of high-dose irradiation for immune activation. The hypothesis of our study posits that instead of directly applying high doses of radiation, which is risky, a strategy could be developed to harness the immune-stimulating benefits of high-dose irradiation indirectly. This involves using nanoparticles to enhance antigen presentation and immune responses in a safer manner. Angiopep-2 (A2) was proved a satisfactory BBB and brain targeting and Dbait is a small molecule that hijack DNA double strand break damage (DSB) repair proteins to make cancer cells more sensitive to radiation. In view of that, the following two nanoparticles were designed to combine immunity of GBM, radiation resistance and BBB innovatively. One is cationic liposome nanoparticle interacting with Dbait (A2-CL/Dbait NPs) for radiosensitization effect; the other is PLGA-PEG-Mal nanoparticle conjugated with OX40 antibody (A2-PLGA-PEG-Mal/anti-OX40 NPs) for tumor-derived protein antigens capture and optimistic immunoregulatory effect of anti-OX40 (which is known to enhance the activation and proliferation T cells). Both types of nanoparticles showed favorable targeting and low toxicity in experimental models. Specifically, the combination of A2-CL/Dbait NPs and A2-PLGA-PEG-Mal/anti-OX40 NPs led to a significant extension in the survival time and a significant tumor shrinkage of mice with GBM. The study demonstrates that combining these innovative nanoparticles with conventional radiotherapy can effectively address key challenges in GBM treatment. It represents a significant step toward more effective and safer therapeutic options for GBM patients.

Overview of damage to beryllium limiters by unmitigated disruptions and runaway electrons in the JET tokamak with metal walls

Abstract The Joint European Torus (JET) fusion reactor was upgraded to the metallic wall configuration in 2011 which consisted of bulk beryllium (Be) tiles in the main chamber and bulk tungsten (W) and W-coated CFC tiles in the divertor [1]. During each campaign, a series of wall damages were observed; on the upper dump plates (UDP) positioned to the top part of the vessel walls and on the inner wall - mainly affecting the inner wall guard limiters (IWGL). In both cases, it was concluded that the causes of these damages were unmitigated plasma disruptions. In the case of JET with the metallic wall configuration, most of these plasma disruptions were intentionally provoked. The overall objective was to study the behaviour of these phenomena, in order to assess their impact on the wall, improve understanding of morphological material changes, and – based on that - to develop, implement and test mitigation techniques for their prospective use on ITER. The current results bring additional information on the effects of the unmitigated plasma disruptions on the UDPs and are a significant extension of work presented in [2] where the scale of the damage after three operational campaigns on the Be top limiters of JET was highlighted. In addition, new data is presented on the damaging effect that the high energetic runaway electrons had on the Be IWGL in JET.

Exploiting the Potential of Iridium(III) bis-Nitrone Complexes as Phosphorogenic Bifunctional Reagents for Phototheranostics.

Cross-linking strategies have found wide applications in chemical biology, enabling the labeling of biomolecules and monitoring of protein-protein interactions. Nitrone exhibits remarkable versatility and applicability in bioorthogonal labeling due to its high reactivity with strained alkynes via the strain-promoted alkyne-nitrone cycloaddition (SPANC) reaction. In this work, four cyclometalated iridium(III) polypyridine complexes functionalized with two nitrone units were designed as novel phosphorogenic bioorthogonal reagents for bioimaging and phototherapeutics. The complexes showed efficient emission quenching, which is attributed to an efficient nonradiative decay pathway via the low-lying T1/S0 minimum energy crossing point (MECP), as revealed by computational studies. However, the complexes displayed significant emission enhancement and lifetime extension upon reaction with (1R,8S,9s)-bicyclo[6.1.0]non-4-yne (BCN) derivatives. In particular, they showed a remarkably higher reaction rate toward a bis-cyclooctyne derivative (bis-BCN) compared with its monomeric counterpart (mono-BCN). Live-cell imaging and (photo)cytotoxicity studies revealed higher photocytotoxicity in bis-BCN-pretreated cells, which is ascribed to the enhanced singlet oxygen (1O2) photosensitization resulting from the elimination of the nitrone-associated quenching pathway. Importantly, the cross-linking properties and enhanced reactivity of the complexes make them highly promising candidates for the development of hydrogels and stapled/cyclized peptides, offering intriguing photophysical, photochemical, and biological properties. Notably, a nanosized hydrogel (2-gel) demonstrated potential as a drug delivery system, while a stapled peptide (2-bis-pDIKK) exhibited p53-Mdm2 inhibitory activity related to apoptosis and a cyclized peptide (2-bis-RGD) showed cancer selectivity.

Micro- and macro-scale fracture behaviour of brittle rocks: Comparison between the conventional Brazilian test and the advanced universal snap-back indirect tensile test (AUSBIT)

Post-peak behaviour is crucial for the estimation of rock mass fracturing in cave mining operations where hard rocks can exhibit class-II or snap-back response when subjected to loading. Despite the rapid development of research into class-II rocks under compression, the corresponding behaviour in tensile tests has rarely been investigated, which is critical considering the complexity of rock mass fracturing under various stress states. The post-peak response of brittle rocks involves abrupt micro-fracturing, leading to brittle macro-scale behaviour. Controlling the fracture process using the Advanced Universal Snap-Back Indirect Tensile test (AUSBIT) allowed the acquisition of the complete macro-scale class-II behaviour in the post-peak regime, facilitating the use of advanced techniques for insights into both micro and macro-scale fracture. In this study, the AUSBIT tests with digital image correlation (DIC) and acoustic emission (AE) instrumentation were conducted to analyse the progressive failure in Calca granite and Gosford sandstone specimens. Post-test observations of the fracture surfaces were performed using a scanning electron microscope (SEM). From a macroscale viewpoint, the lateral strain control in AUSBIT enabled controlled cracking with significant lateral strain extension prior to failure accompanied by gradual energy dissipation and higher rates of AE activity as smaller magnitudes of energy are being released by each AE hit or microcrack compared to conventional Brazilian tests. The stable microcrack propagation was also identified from SEM observations with more uniform profiles of microcracks and less debris observed in AUSBIT specimens. These findings were more significant in Calca granite, which verified its extreme class-II behaviour while also demonstrating the efficiency of AUSBIT in controlling the violent failure of high-strength brittle rocks commonly encountered in deep mining projects, leading to the acquisition of more accurate material behaviour in terms of micro and macro-scale post-peak features which was unattainable from conventional indirect tensile tests.

Generalized strong locality inequality for multi-star-shaped quantum networks

The interest in quantum network correlations has surged, as Bell inequalities originating from a single source fall short of capturing the intricate many-body correlations within generic quantum networks. The introduction of a 3-grade m-star quantum network, a natural extension of star-shaped networks, features a hierarchy of nodes including A, m stars B 1, …, B m centered around A, and m stars C1j,…,Cmj centered around each B j , and m + m 2 independent sources. The strong locality of this network has been explored, assuming that each party possesses only two observables. In this paper, we put forward a significant extension to the strong locality of 3-grade m-star quantum networks. Specifically, each C j k performs n dichotomic measurements, while A and each B j conduct 2 n−1 dichotomic measurements. We establish a generalized strong locality inequality that holds for any value of n, and subsequently conduct a thorough analysis to determine the optimal quantum violation of established inequality. Through specific examples, we confirm the feasibility of achieving the optimal quantum violation of the generalized strong locality inequality for any n. We notice that for n > 3, a single copy of a two-qubit entangled state may not be sufficient to reveal the non-strong locality, whereas utilizing multiple copies can trigger this property.