Due to scheduled maintenance work on our servers, there may be short service disruptions on this website between 11:00 and 12:00 CEST on March 28th.
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (2,952)

Search Parameters:
Keywords = structured cavities

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
22 pages, 24061 KB  
Case Report
Different Approaches to the Treatment of Radicular and Related Cysts Associated with Nasal Mucosa in the Maxilla: A Case Series
by Ömer Uranbey, Kamil Nelke, Furkan Diri, Burcu Gürsoytrak, Füruzan Kaçar Döger, Lale Okumuş, Agata Małyszek, Maciej Janeczek, Filip Kulewicz and Maciej Dobrzyński
J. Clin. Med. 2026, 15(6), 2411; https://doi.org/10.3390/jcm15062411 - 21 Mar 2026
Viewed by 142
Abstract
Radicular cysts (RCs) represent the most frequent inflammatory cystic lesions of the jaw, typically arising from non-vital teeth. While standard management via enucleation is well-documented, complex cases involving the anterior maxilla present significant surgical challenges due to their proximity to the nasal cavity [...] Read more.
Radicular cysts (RCs) represent the most frequent inflammatory cystic lesions of the jaw, typically arising from non-vital teeth. While standard management via enucleation is well-documented, complex cases involving the anterior maxilla present significant surgical challenges due to their proximity to the nasal cavity floor (NCF) and the maxillary sinus floor (MSF). This report provides a comprehensive revision of a clinical case series involving seven patients (ages 17–50) treated with multimodal surgical and regenerative protocols. The patients were stratified into five distinct anatomical risk groups (A–E) based on the integrity of the bony boundaries and the presence of oronasal communications. The treatment strategies combined meticulous cyst enucleation with advanced regenerative techniques, including platelet-rich fibrin (PRF), allogeneic and xenograft bone substitutes, and local flaps such as the buccal fat pad (BFP). The results across all seven cases demonstrated favorable clinical and radiographic outcomes, with no instances of oronasal fistula formation or recurrence during follow-up periods ranging from 12 months to three years. This report emphasizes the necessity of structured anatomical stratification and multimodal planning to ensure scientific precision and surgical predictability in the management of complex maxillary lesions. The differences between approaches towards the nasal cavity and maxillary sinus have to be highlighted. Further studies with larger cohorts are warranted to evaluate the long-term outcomes of different treatment modalities. Full article
(This article belongs to the Section Dentistry, Oral Surgery and Oral Medicine)
Show Figures

Figure 1

15 pages, 3888 KB  
Article
Ultra-Miniaturized, High-Q Embedded Loaded Coaxial Substrate Integrated Waveguide Filter
by Nawaf R. Almuqati, Gokhan Ariturk and Hjalti H. Sigmarsson
Electronics 2026, 15(6), 1310; https://doi.org/10.3390/electronics15061310 - 20 Mar 2026
Viewed by 160
Abstract
This paper presents an ultra-miniaturized and high-quality factor embedded loaded coaxial substrate integrated waveguide (ELCSIW) filter. Integrating a substrate-integrated coaxial resonator with a capacitively loaded air cavity achieves a 99% reduction in size compared to a conventional SIW cavity. Incorporating an air gap [...] Read more.
This paper presents an ultra-miniaturized and high-quality factor embedded loaded coaxial substrate integrated waveguide (ELCSIW) filter. Integrating a substrate-integrated coaxial resonator with a capacitively loaded air cavity achieves a 99% reduction in size compared to a conventional SIW cavity. Incorporating an air gap in the capacitive loading structure significantly enhances the resonator’s quality factor. A comprehensive analysis of the miniaturization factor and quality factor in relation to cavity structure dimensions is performed. Guidelines for fabricating the highly loaded cavity are presented. To demonstrate the benefits of this technique, a two-pole band-pass filter with a 6.3% bandwidth at 1.1 GHz is designed, fabricated, and measured. The overall footprint of the filter is 10.5 mm × 20.5 mm, which is comparable to 0.07 λg× 0.14 λg. The measured insertion loss is 0.54 dB, and the upper band is spurious-free up to 7 times the resonant frequency. The exceptional performance and compactness of the loaded coaxial substrate integrated waveguide cavities highlight their immense potential for compact advanced wireless systems. Full article
(This article belongs to the Section Microwave and Wireless Communications)
Show Figures

Figure 1

8 pages, 754 KB  
Case Report
Gossypiboma Following Cesarean Section Presenting as Bilateral Abdominal Abscesses: A Case Report
by Bogdan-Mihnea Ciuntu, Irina Mihaela Abdulan, Dumitrel Băiceanu, Mihaela Corlade-Andrei, Sorin Nicolae Peiu, Raluca Dragomir, Gheorghe Balan, Andrea Ludușanu, Radu Valentin Averescu and Dan Andronic
J. Clin. Med. 2026, 15(6), 2377; https://doi.org/10.3390/jcm15062377 - 20 Mar 2026
Viewed by 154
Abstract
Background: Gossypiboma is an uncommon postoperative complication caused by the retention of surgical materials, most frequently sponges, and is associated with substantial morbidity and medicolegal consequences. Despite a reduction in reported incidence, diagnosis remains challenging due to its nonspecific clinical presentation. Case [...] Read more.
Background: Gossypiboma is an uncommon postoperative complication caused by the retention of surgical materials, most frequently sponges, and is associated with substantial morbidity and medicolegal consequences. Despite a reduction in reported incidence, diagnosis remains challenging due to its nonspecific clinical presentation. Case Presentation: We present the case of a 36-year-old woman who presented with a one-week history of throbbing abdominal pain in the umbilical and left lumbar regions, associated with fetid leukorrhea. Her medical history included an appendectomy, a recent cesarean section performed two months prior, and pregnancy-induced hypertension. Initial computed tomography revealed bilateral subcutaneous and intra-abdominal collections with air bubbles and hyperdense linear structures, raising suspicion of abdominal abscesses. Gynecological evaluation excluded pelvic inflammatory pathology. Exploratory laparotomy identified bilateral pseudotumoral masses with complex adhesions involving intestinal loops and omentum, without evidence of gynecologic infection, prompting transfer to a tertiary care center. Repeat imaging confirmed bilateral flank abscesses. Surgical reintervention revealed retained surgical sponges within both abscess cavities, which were successfully removed, followed by evacuation, lavage, and drainage. Postoperative evolution was favorable under broad-spectrum antibiotic therapy, with complete clinical and biological recovery. Conclusions: This case highlights the diagnostic challenge of gossypiboma, particularly when mimicking intra-abdominal abscesses or adhesion syndromes. A high index of suspicion is required in patients with prior surgical history and atypical postoperative presentations, as early recognition and prompt surgical management are essential to reduce morbidity and medicolegal consequences. Full article
(This article belongs to the Section General Surgery)
Show Figures

Figure 1

24 pages, 11367 KB  
Article
Potential Activity of 6-Pentyl-α-pyrone as an Antiviral for Bovine Coronavirus
by Luca Del Sorbo, Rosa Giugliano, Clementina Acconcia, Maria Michela Salvatore, Alessia Staropoli, Violetta Iris Vasinioti, Maria Stella Lucente, Paolo Capozza, Francesco Vinale, Annamaria Pratelli, Luigi Russo, Rosa Iacovino and Filomena Fiorito
Pathogens 2026, 15(3), 332; https://doi.org/10.3390/pathogens15030332 - 20 Mar 2026
Viewed by 161
Abstract
During infection in vitro with the strain 438/06 of bovine coronavirus (BCoV), a β-coronavirus similar to severe acute respiratory syndrome (SARS) CoV-2, treatment with 6-pentyl-α-pyrone (6PP), a fungal metabolite obtained from Trichoderma atroviride, was recently shown to influence viral load by reducing [...] Read more.
During infection in vitro with the strain 438/06 of bovine coronavirus (BCoV), a β-coronavirus similar to severe acute respiratory syndrome (SARS) CoV-2, treatment with 6-pentyl-α-pyrone (6PP), a fungal metabolite obtained from Trichoderma atroviride, was recently shown to influence viral load by reducing viral entry. Herein, the ability of 6PP to counteract the BCoV infection was further investigated both in vitro and in silico. Following the BCoV (strain 282/23) infection in bovine (MDBK) cells, the 6PP in co-treatment increased cell viability, reduced morphological signs of cell death, and significantly inhibited viral yield, by lessening the expression of the viral spike (S) protein, as well as the gene transcription of the viral nucleocapsid (NP) protein. In addition, a noticeable down-regulation in the expression of aryl hydrocarbon receptor (AhR) signaling, a strategic modulator of CoVs infection, was found. Molecular docking studies were performed to evaluate the potential interaction between 6PP and AhR involved in the BCoV infection. The docking 3D structural model showed that 6PP fits into a binding pocket positioned between the PASB and TAD domains of bovine AhR (bAhR), where the ligand is stabilized through hydrophobic interactions. In addition, the obtained computational data strongly suggest that the bAhR binding mechanism of 6PP is principally mediated by a well-conserved hydrophobic cavity playing a key role in the modulation of the receptor functions. Overall, our findings showed an antiviral action of 6PP versus BCoV infection in vitro and in silico. Full article
(This article belongs to the Special Issue Emerging/Re-Emerging Viruses and Antiviral Drug Design)
Show Figures

Figure 1

16 pages, 7376 KB  
Article
A Temperature Measurement and System Identification Method for Confined Cavity Explosions Based on an Improved Type C Thermocouple Sensor
by Zhaoxiang Niu, Jijun Zhang, Deqian Kong, Hongchuan Jiang and Meng Kou
Sensors 2026, 26(6), 1948; https://doi.org/10.3390/s26061948 - 20 Mar 2026
Viewed by 131
Abstract
This paper proposes a temperature measurement and system identification method for confined cavity explosions based on an improved type C thermocouple sensor. On the one hand, to address the extreme conditions caused by high-speed fragments and intense shock waves in an enclosed explosive [...] Read more.
This paper proposes a temperature measurement and system identification method for confined cavity explosions based on an improved type C thermocouple sensor. On the one hand, to address the extreme conditions caused by high-speed fragments and intense shock waves in an enclosed explosive environment, a thermocouple probe structure employing alloy strips of different widths with an alumina insulating layer in between is designed. By optimizing the strip width, the contact issues arising from edge-cutting burrs are effectively suppressed, thereby significantly enhancing the electrical insulation performance and overall reliability of the sensor. Additionally, a wedge-shaped alumina ceramic piece is designed to secure the thermocouple probe, further improving its structural stability under impact conditions. On the other hand, to tackle the highly nonlinear and multi-field coupled characteristics of the post-explosion temperature field, a system identification method based on the least square method is proposed. This method constructs a polynomial function in terms of radial distance and time variables, enabling effective reconstruction of the temperature field from limited measurement points. It provides a useful reference for understanding of the temperature distribution in confined cavity explosions and supports improved estimation of the temperature field. Finally, experimental results demonstrate that the improved sensor exhibits good survivability and measurement reliability under extreme explosive conditions. Meanwhile, the reconstructed temperature field model shows high fitting accuracy and good capability for describing the temperature distribution, confirming the effectiveness of the proposed identification method. Full article
(This article belongs to the Section Electronic Sensors)
Show Figures

Figure 1

17 pages, 1414 KB  
Article
Long-Term Clinical Consequences of Severe Oral Mucositis in Survivors of Lip, Oral Cavity, and Pharynx Cancer Versus Leukemia: A Propensity-Score-Matched Comparative Cohort Study Using Real-World Data
by Poolakkad S. Satheeshkumar, Venu Gopalakrishnan, Joel B. Epstein and Roberto Pili
Med. Sci. 2026, 14(1), 142; https://doi.org/10.3390/medsci14010142 - 18 Mar 2026
Viewed by 138
Abstract
Background/Objectives: Severe oral mucositis is widely viewed as a transient toxicity of antineoplastic therapy. Whether its long-term consequences differ between cancers that directly damage the upper aerodigestive tract (cancers of the lip, oral cavity, pharynx [CLOP]) and systemic hematologic malignancies is unknown. The [...] Read more.
Background/Objectives: Severe oral mucositis is widely viewed as a transient toxicity of antineoplastic therapy. Whether its long-term consequences differ between cancers that directly damage the upper aerodigestive tract (cancers of the lip, oral cavity, pharynx [CLOP]) and systemic hematologic malignancies is unknown. The aim of this study was to compare lifetime risks of mortality, dysphagia, malnutrition, respiratory disease, and cardiovascular disease in propensity-score-matched survivors of CLOP cancer versus leukemia with and without a history of ulcerative oral mucositis. Methods: Population-based retrospective cohort study using the TriNetX US Collaborative Network (90 healthcare organizations, >110 million patients). We identified 80,526 adults with a personal history of CLOP cancer (ICD-10-CM Z85.81) and 43,684 with leukemia (Z85.6) from 2005 to 2024. Cohorts were stratified by presence/absence of severe oral mucositis (K12.31 or K12.33 at any time). Separate 1:1 propensity-score matching was performed within each cancer type on age, sex, race/ethnicity, hypertension, diabetes, BMI, ECOG status, and external causes of morbidity. Exposures included documented severe (ulcerative) oral mucositis. Main outcomes and measures were all-cause mortality and incident dysphagia, malnutrition, respiratory disease (J00–J99), influenza/pneumonia (J09–J18), and circulatory disease (I00–I99) after the index date. Results: After 1:1 matching, 4181 CLOP patients with mucositis were compared with 4181 without, and 2508 leukemia patients with mucositis were compared with 2508 without. In CLOP survivors, mucositis was associated with markedly higher lifetime mortality (adjusted HR 1.94, 95% CI 1.87–2.01), dysphagia (HR 3.42, 95% CI 3.28–3.57), malnutrition (HR 2.81, 95% CI 2.66–2.97), any respiratory disease (HR 1.68, 95% CI 1.63–1.73), and influenza/pneumonia (HR 1.79, 95% CI 1.72–1.86). In leukemia survivors, mucositis conferred only modest or null excess risk (mortality HR 1.12, 95% CI 1.05–1.19; dysphagia HR 1.18, 95% CI 1.07–1.30; malnutrition HR 1.24, 95% CI 1.12–1.37; any respiratory disease HR 1.09, 95% CI 1.03–1.15). Conclusions and Relevance: Severe oral mucositis is a powerful, durable prognostic determinant in cancers of the upper aerodigestive tract, where it identifies patients associated with elevated lifelong risk of swallowing dysfunction, aspiration-related lung disease, malnutrition, and premature death. The markedly attenuated effect in leukemia survivors suggests that direct high-dose radiation-induced structural damage to the pharynx and oral cavity—rather than systemic immunosuppression or chemotherapy intensity alone—is the dominant mechanism. Full article
(This article belongs to the Special Issue Feature Papers in Section “Cancer and Cancer-Related Research”)
Show Figures

Figure 1

31 pages, 3741 KB  
Review
Hollow Graphitic Nanoshells as a Material for Ion Batteries
by Maria Hasan, Alicja Bachmatiuk, Gražyna Simha Martynková, Karla Čech Barabaszová and Mark H. Rümmeli
Materials 2026, 19(6), 1187; https://doi.org/10.3390/ma19061187 - 18 Mar 2026
Viewed by 243
Abstract
Hollow graphitic nanoshells (HGSs) are widely investigated as battery materials because their conductive shells and internal voids can simultaneously influence ion transport, electron percolation, and mechanical stress accommodation. Yet, the field remains largely morphology-driven, with performance often attributed generically to “hollowness” rather than [...] Read more.
Hollow graphitic nanoshells (HGSs) are widely investigated as battery materials because their conductive shells and internal voids can simultaneously influence ion transport, electron percolation, and mechanical stress accommodation. Yet, the field remains largely morphology-driven, with performance often attributed generically to “hollowness” rather than to structural parameters. This review examines HGSs from a parameter-oriented perspective. It highlights key structural features, including graphitization degree, shell thickness, cavity size, pore architecture, and defect or dopant chemistry. These features collectively shape electrochemical behavior. We discuss how these features influence transport kinetics, interphase stability, volumetric efficiency, and mechanical resilience across insertion, metal anode, multivalent, solid-state, and halogen chemistries. Major synthesis approaches, including hard-templated, soft-templated, self-templated, and biomass-derived routes, are evaluated based on the structural control they provide and the influence of synthesis conditions on shell architecture, graphitic ordering, and pore structure. Special attention is given to how these structural features develop during processing and how they affect ion accessibility, conductivity, and stability. Finally, we outline a shift toward quantitative, parameter-driven engineering supported by operando diagnostics, electrode-level modeling, and standardized reporting. HGSs will only achieve practical relevance when structural optimization extends beyond particle morphology to transport uniformity, interfacial stability, network connectivity, and life-cycle responsibility. Full article
(This article belongs to the Section Energy Materials)
Show Figures

Graphical abstract

23 pages, 614 KB  
Review
Bioactive Hydrogels and Scaffolds for Oral Mucosal Regeneration After Oral Squamous Cell Carcinoma Therapy: A Comprehensive Review
by Alina Ormenisan, Andreea Bors, Liana Beresescu, Despina Luciana Bereczki-Temistocle and Gabriela Felicia Beresescu
Medicina 2026, 62(3), 558; https://doi.org/10.3390/medicina62030558 - 17 Mar 2026
Viewed by 257
Abstract
Oral squamous cell carcinoma (OSCC) therapy frequently produces acute and chronic injury to the oral mucosa, including surgical lining defects and radiochemotherapy-associated oral mucositis (OM). Beyond pain and ulceration, these injuries compromise nutrition, speech, oral hygiene, and feasibility of dental/implant rehabilitation, and may [...] Read more.
Oral squamous cell carcinoma (OSCC) therapy frequently produces acute and chronic injury to the oral mucosa, including surgical lining defects and radiochemotherapy-associated oral mucositis (OM). Beyond pain and ulceration, these injuries compromise nutrition, speech, oral hygiene, and feasibility of dental/implant rehabilitation, and may disrupt oncologic treatment delivery. The oral cavity imposes stringent constraints on regenerative biomaterials—continuous salivary flow, high microbial load, and repeated mechanical shear—such that clinical success depends on reliable mucoadhesion/wet adhesion, barrier function, mechanical compliance, and safe, spatially confined bioactivity. This PRISMA-informed evidence-mapped structured narrative review provides an evidence map and structured qualitative synthesis of hydrogel and scaffold platforms relevant to post-OSCC care, spanning clinically used mucoadhesive barrier formulations through emerging wet-adhesive multifunctional patches, acellular matrices, and tissue-engineered oral mucosa (TEOM) constructs. Clinically, the strongest evidence base remains barrier-forming gels and liquids that reduce OM pain and improve oral function during active therapy, establishing performance benchmarks for intraoral retention and patient-reported benefit. Preclinical studies are rapidly expanding toward multifunctional designs that integrate antimicrobial, anti-inflammatory, pro-epithelialization, and pro-angiogenic cues. However, a pervasive limitation is the inconsistent use of OSCC-relevant models (e.g., irradiated/xerostomic tissue beds), standardized functional endpoints (e.g., oral intake, durability under mastication, and neurosensory outcomes), and explicit oncologic safety evaluation, which severely compromises translational validity. For reconstructive applications, dermal matrices and early TEOM reports suggest feasibility for selected defects, but controlled comparative trials and scalable manufacturing pathways remain limited. Translational priorities include oncologic-by-design bioactivity (time-limited, locally confined cues), clinically anchored outcome reporting, and quality-by-design manufacturing aligned with device/combination/advanced-therapy regulatory requirements. Full article
(This article belongs to the Special Issue Regenerative Dentistry: A New Paradigm in Oral Health Care)
Show Figures

Figure 1

35 pages, 28279 KB  
Article
Return of Experience in the Commissioning of the New CLS LINAC Injector
by Frédéric Le Pimpec, Ward A. Wurtz, Johannes M. Vogt, Xavier Stragier, Tylor Sové, Jon Stampe, Sheldon Smith, Benjamen Smith, David Schneberger, Xiaofeng Shen, Bryan Schreiner, Brian Schneider, Shervin Saadat, Alex Rosset, Melissa A. Ratzlaff, Chelsea-Lea Randall, Emma Paulson, Alexander Nikolaichuk, Eduardo Nebot del Busto, Tyler Morhart, Thomas McKeith, Karen McKeith, Andrew McCormick, Linda Lin, Rukma Shree Kotha, Iaroslav Kolmakov, Emilio Heredia, Julia Doucette-Garr, Joshua Erikson, Brock Dube, Shawn Carriere, John Campbell, Michael Bree, Grant Bilbrough, Duane Bergstrom, Denis Beauregard, Tonia Batten, Cameron Baribeau, Johannes Hottenbacher, Peter Biegun, Benjamin Bromberger, Kai Dunkel, Marc Grewe, Björn Keune, Wolfgang Korte, Anja Kraemer, Christian Piel and Anne Vanselowadd Show full author list remove Hide full author list
Instruments 2026, 10(1), 17; https://doi.org/10.3390/instruments10010017 - 16 Mar 2026
Viewed by 220
Abstract
After approximately 60 years of service, the 2856 MHz LINAC injector, of the Canadian Light Source (CLS), has been retired to make space for a new 3000.24 MHz LINAC injector, the frequency of which is a multiple of the 500.04 MHz CESR-B-type superconductive [...] Read more.
After approximately 60 years of service, the 2856 MHz LINAC injector, of the Canadian Light Source (CLS), has been retired to make space for a new 3000.24 MHz LINAC injector, the frequency of which is a multiple of the 500.04 MHz CESR-B-type superconductive radio frequency cavity used in the CLS storage ring. The new CLS LINAC injector has been designed and built by RI Research Instruments GmbH. The design is based on their robust S-band RF traveling-wave accelerating structures technology already serving other laboratories in the USA, Australia, Taiwan, Switzerland, and Sweden. In order to reduce cost and optimize space, the CLS has replaced its six accelerating RF structures, each 3.05 m long, delivering a 250 MeV electron beam with three 5.26 m long accelerating structures that will deliver the same beam energy. In order to do so, one RF structure is powered by one klystron modulator, and the last two RF structures receive their RF power from a second klystron modulator that passes through a SLED system. The SLED system multiplies the peak power by a factor of 5 to 6 and is then equally split to power each structure. We are reporting on the issues encountered during the commissioning of this new injector, on how we have tackled them and where the injector, compared to its technical specification, is standing today. Full article
(This article belongs to the Section Particle Detectors and Accelerators)
Show Figures

Figure 1

34 pages, 32077 KB  
Review
Rational Design of Hollow Nanostructures: Engineering the Cavity Microenvironment for Advanced Electrocatalysis
by Yong-Gang Sun, Xin Wang, Jian Xiong, Yi-Han Zhang, Jin-Yi Ding, Bo Peng, Yuan Gu, Yi-Cong Xie, Kang-Lin Zhang, Mao Yuan and Xi-Jie Lin
Nanomaterials 2026, 16(6), 360; https://doi.org/10.3390/nano16060360 - 15 Mar 2026
Viewed by 340
Abstract
Hollow nanostructures have emerged as a pivotal class of nanomaterials in electrocatalysis, offering intrinsic advantages such as high surface-to-volume ratios, reduced density, and economical utilization of precious metals. However, the prevailing research paradigm has predominantly focused on the external shell characteristics while overlooking [...] Read more.
Hollow nanostructures have emerged as a pivotal class of nanomaterials in electrocatalysis, offering intrinsic advantages such as high surface-to-volume ratios, reduced density, and economical utilization of precious metals. However, the prevailing research paradigm has predominantly focused on the external shell characteristics while overlooking the decisive role of the interior cavity microenvironment. This review introduces a novel conceptual framework that positions the rational engineering of the cavity microenvironment—encompassing mass transport dynamics, localized electronic structure modulation, active site exposure, and structural stability—as a unified design principle for next-generation electrocatalysts. We systematically elucidate how precise control over cavity geometry, composition, and interfacial properties can optimize electrocatalytic performance for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions. By correlating microenvironmental parameters with catalytic metrics, we establish structure–property–performance relationships and highlight recent breakthroughs. Finally, we outline future challenges in achieving atomic-level precision in cavity design, understanding dynamic evolution under operating conditions, and scaling up synthesis for industrial applications. Full article
Show Figures

Figure 1

13 pages, 2522 KB  
Article
Cavitand-Mediated Photodimerization of Chalcones: The Effect of Supramolecular Influences and Temperature on Reaction Selectivity
by Joydip Chatterjee, Mahesh Pattabiraman, Debajit Chakraborty, Aleksander L. Wysocki and Frank Kovacs
Molecules 2026, 31(6), 983; https://doi.org/10.3390/molecules31060983 - 15 Mar 2026
Viewed by 211
Abstract
The photocycloaddition (PCA) of chalcones represents an important reaction pathway for accessing substituted cyclobutanes, which is a molecular framework with utility in synthetic chemistry, materials science, and medicine. In the past, our group has demonstrated the utility of the large cavity of γ-CD [...] Read more.
The photocycloaddition (PCA) of chalcones represents an important reaction pathway for accessing substituted cyclobutanes, which is a molecular framework with utility in synthetic chemistry, materials science, and medicine. In the past, our group has demonstrated the utility of the large cavity of γ-CD as a container for encapsulating two photo reactants for directing the PCA of several classes of aryl alkenes with high stereo- and regioselectivity: the cavitand-mediated photodimerization (CMP) approach. The CMP of chalcones reported in this work further demonstrates the effectiveness of this approach as high yields of dimers were observed in the photoreactions, while they were non-reactive in the solid state and yielded only the isomerization product in homogeneous media. The γ-CD CMP of chalcones yielded predominantly dimerized products in very good to high yields (>70%), composed of a mixture of three dimers in different proportions with syn HH as the major product. Computational analysis of the ground state complex structures revealed a strong correlation between the stability of the complex and predominance of the stereoisomer in the mixture. Further insights were deduced from temperature-dependence studies, which showed a shift in dimer selectivity tending towards a single stereoisomer. Full article
(This article belongs to the Special Issue Recent Advances in Supramolecular and Surface Photochemistry)
Show Figures

Figure 1

35 pages, 9007 KB  
Article
Thermal Symmetry Breakdown in Finned Natural Convection Cavities: Band-Resolved Nusselt Statistics and Multivariate Analysis Across Conductivity Ratios
by Saleh A. Bawazeer and Mohammad S. Alsoufi
Symmetry 2026, 18(3), 496; https://doi.org/10.3390/sym18030496 - 13 Mar 2026
Viewed by 215
Abstract
This study investigates the breakdown of thermal symmetry in finned square cavities under natural convection, focusing on how the fin-to-fluid conductivity ratio governs heat-transfer redistribution and localization. A band-resolved statistical framework is employed to analyze hot- and cold-wall Nusselt number responses across conductivity [...] Read more.
This study investigates the breakdown of thermal symmetry in finned square cavities under natural convection, focusing on how the fin-to-fluid conductivity ratio governs heat-transfer redistribution and localization. A band-resolved statistical framework is employed to analyze hot- and cold-wall Nusselt number responses across conductivity ratios (kr) ranging from symmetric to highly contrasting conditions. At kr=1, the cavity exhibits a fully symmetric conduction–convection regime with complete wall-to-wall coupling and a unified thermal response. Increasing the conductivity ratio to kr=10 introduces a transitional regime marked by mild but systematic asymmetry, with convective activity beginning to favor the cold wall. At kr=100, the system undergoes a structural transition to a strongly asymmetric state, characterized by attenuation of hot-wall convection and sustained cold-wall dominance. Under extreme ratio (kr=1000), convective heat transfer becomes highly localized at the cold wall, forming a directional thermal pathway. Joint Gaussian envelopes, regression scaling, principal component analysis, and Hotelling separation collectively demonstrate that symmetry breakdown proceeds through distinct, statistically separable stages, rather than emerging as a gradual shift in mean heat-transfer intensity. The results establish cold-wall localization as the governing physical mechanism and provide a unified framework for controlling convective heat transfer in fin-assisted natural-convection systems. Full article
(This article belongs to the Section Physics)
Show Figures

Figure 1

18 pages, 3684 KB  
Article
Effect of Geometric Parameters in the Seal Clearance on the Modal Characteristics of Pump-Turbine Runner
by Xue Zhao, Yu Tian, Ran Tao, Lingjiu Zhou and Zhengwei Wang
Water 2026, 18(6), 671; https://doi.org/10.3390/w18060671 - 13 Mar 2026
Viewed by 151
Abstract
The runner of a pump turbine features a relatively flat structural configuration. The clearance cavities formed between the upper crown, lower band, and surrounding stationary components play a critical role in its dynamic behavior and operational stability. Consequently, a detailed modal analysis of [...] Read more.
The runner of a pump turbine features a relatively flat structural configuration. The clearance cavities formed between the upper crown, lower band, and surrounding stationary components play a critical role in its dynamic behavior and operational stability. Consequently, a detailed modal analysis of the runner is essential to ensure safe and stable operation. In this study, an acoustic–structure coupling method is adopted to investigate the wet modal characteristics of the pump-turbine runner, explicitly accounting for the added mass effect induced by the fluid in the external flow passages. By systematically varying the geometric parameters of the upper crown clearance cavity, the influence of seal clearance dimensions on the runner’s modal characteristics is examined. The results demonstrate that the radial clearance and the axial height of the seal cavity are the most influential parameters, reducing natural frequencies by up to 15.85% and 16.93%, respectively. The pitch of the seal teeth shows a secondary yet notable effect, inducing a frequency variation of 13.73%. In contrast, local labyrinth seal parameters, such as the number of teeth and tooth width, have a comparatively limited effect. This study provides practical guidance for vibration risk prediction, anti-resonance design, and operational stability assessment of high-head, large-capacity turbine runners by revealing the quantitative relationship between geometric parameters and modal frequencies. Full article
(This article belongs to the Section Hydraulics and Hydrodynamics)
Show Figures

Figure 1

23 pages, 17130 KB  
Article
Dolmens in a Land of Caves: The Azurrague Pre-Historic Monument (Ourém—Central Portugal)
by Alexandra Figueiredo and Cláudio Monteiro
Humans 2026, 6(1), 9; https://doi.org/10.3390/humans6010009 - 12 Mar 2026
Viewed by 170
Abstract
The article presents the preliminary data from the excavation of the Azurrague 1 Dolmen (Ourém), carried out within the MEDICE II project, highlighting the importance of its location in a karstic landscape marked by a strong tradition of funerary cults in natural cavities. [...] Read more.
The article presents the preliminary data from the excavation of the Azurrague 1 Dolmen (Ourém), carried out within the MEDICE II project, highlighting the importance of its location in a karstic landscape marked by a strong tradition of funerary cults in natural cavities. The dolmen structure features a heptagonal chamber and a short passage, with ritual deposits that include macrolithic tools, polished axes, ceramics, and human remains dated between the beginning of the Late Neolithic and the Middle Chalcolithic. The data indicates practices of secondary burial, continuity of regional lithic traditions, and a symbolic integration between exogenous architectural forms and endogenous ritual content established in caves. The proximity to caves with contemporary chronologies, such as Lapa da Furada, reinforces the coexistence of differentiated yet interconnected ritual spaces. Analogies with the Rego da Murta Megalithic Complex, caves and other sites in the Alto Nabão region support the hypothesis of a hybrid, long-lasting cultural system in which megalithic monumentalization is associated with ancestral symbolic practices. Full article
Show Figures

Figure 1

15 pages, 10540 KB  
Article
Piezoelectric Thin-Film Actuator for Dynamic Tuning of Micro-Optical Cavities
by Dehua Tan, Pengfei Li, Xuyang Zhou, Qingxiong Xiao, Chaohui Wu, Qixuan Zhu, Miao Lei, Ting Li and Qianbo Lu
Micromachines 2026, 17(3), 345; https://doi.org/10.3390/mi17030345 - 12 Mar 2026
Viewed by 231
Abstract
In micro-opto-electro-mechanical systems (MOEMS), the micro-optical cavity plays a pivotal role. As performance requirements for MOEMS devices continue to rise, these cavities must achieve higher performance levels while simultaneously reducing their physical footprint. However, existing high-precision micro-optical cavities face challenges such as high [...] Read more.
In micro-opto-electro-mechanical systems (MOEMS), the micro-optical cavity plays a pivotal role. As performance requirements for MOEMS devices continue to rise, these cavities must achieve higher performance levels while simultaneously reducing their physical footprint. However, existing high-precision micro-optical cavities face challenges such as high process sensitivity and conflicting trade-offs between dynamic range and precision. To address these issues, piezoelectric thin-film actuators present a viable solution due to their high precision, stroke flexibility, electromagnetic interference resistance, and structural scalability. This study proposes a piezoelectric thin-film actuator based on the d33 mode. The device adopts an island-circular structure that integrates a lead zirconate titanate (PZT) piezoelectric film with metal electrodes. By employing particle swarm optimization (PSO) to enhance displacement output and anti-gravity capabilities, the actuator achieves displacement outputs below 100 nm within a compact form factor while maintaining nanometer-level resolution. Simulation and experimental results confirm a first-order natural frequency of approximately 5.8 kHz, along with a reasonable linear displacement response across a 4–6 V drive voltage range. Furthermore, the device demonstrates functionality within a Fabry–Pérot (F-P) microcavity system, enabling active optical path length modulation through precise cavity tuning. This research provides an effective approach to enhancing the dynamic performance and process compatibility of micro-optical cavity devices, advancing the development of next-generation MOEMS systems. Full article
Show Figures

Figure 1

Back to TopTop