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1.
Physiol Plant ; 176(4): e14388, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38946634

RESUMEN

Plants can experience a variety of environmental stresses that significantly impact their fitness and survival. Additionally, biotic stress can harm agriculture, leading to reduced crop yields and economic losses worldwide. As a result, plants have developed defense strategies to combat potential invaders. These strategies involve regulating redox homeostasis. Several studies have documented the positive role of plant antioxidants, including Ascorbate (Asc), under biotic stress conditions. Asc is a multifaceted antioxidant that scavenges ROS, acts as a co-factor for different enzymes, regulates gene expression, and facilitates iron transport. However, little attention has been given to Asc and its transport, regulatory effects, interplay with phytohormones, and involvement in defense processes under biotic stress. Asc interacts with other components of the redox system and phytohormones to activate various defense responses that reduce the growth of plant pathogens and promote plant growth and development under biotic stress conditions. Scientific reports indicate that Asc can significantly contribute to plant resistance against biotic stress through mutual interactions with components of the redox and hormonal systems. This review focuses on the role of Asc in enhancing plant resistance against pathogens. Further research is necessary to gain a more comprehensive understanding of the molecular and cellular regulatory processes involved.


Asunto(s)
Ácido Ascórbico , Reguladores del Crecimiento de las Plantas , Plantas , Estrés Fisiológico , Reguladores del Crecimiento de las Plantas/metabolismo , Ácido Ascórbico/metabolismo , Plantas/metabolismo , Plantas/inmunología , Antioxidantes/metabolismo , Oxidación-Reducción , Regulación de la Expresión Génica de las Plantas , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/microbiología
2.
Proc Natl Acad Sci U S A ; 121(28): e2400737121, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38968127

RESUMEN

In recent years, the exploration of genome three-dimensional (3D) conformation has yielded profound insights into the regulation of gene expression and cellular functions in both animals and plants. While animals exhibit a characteristic genome topology defined by topologically associating domains (TADs), plants display similar features with a more diverse conformation across species. Employing advanced high-throughput sequencing and microscopy techniques, we investigated the landscape of 26 histone modifications and RNA polymerase II distribution in tomato (Solanum lycopersicum). Our study unveiled a rich and nuanced epigenetic landscape, shedding light on distinct chromatin states associated with heterochromatin formation and gene silencing. Moreover, we elucidated the intricate interplay between these chromatin states and the overall topology of the genome. Employing a genetic approach, we delved into the role of the histone modification H3K9ac in genome topology. Notably, our investigation revealed that the ectopic deposition of this chromatin mark triggered a reorganization of the 3D chromatin structure, defining different TAD-like borders. Our work emphasizes the critical role of H3K9ac in shaping the topology of the tomato genome, providing valuable insights into the epigenetic landscape of this agriculturally significant crop species.


Asunto(s)
Epigenoma , Histonas , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Histonas/metabolismo , Histonas/genética , Epigénesis Genética , Genoma de Planta , Cromatina/metabolismo , Cromatina/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Heterocromatina/metabolismo , Heterocromatina/genética , Código de Histonas/genética
4.
Polymers (Basel) ; 16(11)2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38891480

RESUMEN

BACKGROUND: Sealing the peri-implant tissue is a determining factor for long-term implant survival. In the transmucosal region, the cervical fraction of the prosthetic crown is in contact with these tissues, so mucointegration will also be influenced by the biomaterial used for the prosthetic restoration. This study aims to compare the tissue response generated by definitive restorative materials and polymeric materials from a histological point of view. METHODS: This study performed an observational prospective cohort study in which biopsies of the peri-implant mucosa were taken after placement of implant-supported prosthetic restorations made of different materials (zirconium oxide, lithium disilicate, and PMMA). RESULTS: A statistically significant difference was observed in the increase in the thickness of the non-keratinized epithelium when comparing the definitive materials (zirconium oxide/lithium disilicate) vs. the provisional material (PMMA) and in the number of collagen fibers when comparing zirconium oxide and lithium disilicate. CONCLUSIONS: This study found that zirconia is the material that presents the most adequate biological response of peri-implant tissues. It shows a lower intensity of inflammatory cellular content, a total normality in the number of collagen fibers (the arrangement of the fibers is normal in 90% of the cases), and vascular proliferation of connective tissue in 83% of the cases. These parameters make it a material with a predictable response. Similarly, only the following slight statistically significant differences between the definitive and provisional materials are observed, indicating that the biological response generated by the provisional material (PMMA) is not very different from that obtained with the placement of the definitive restoration.

6.
Schizophr Res ; 270: 260-272, 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38944972

RESUMEN

BACKGROUND: It is known that the immune system is dysregulated in schizophrenia, having a state similar to chronic neuroinflammation. The origin of this process is unknown, but it is known that T and B lymphocytes, which are components of the adaptive immune system, play an important role in the pathogenic mechanisms of schizophrenia. METHODS: We analysed the membrane of PBMCs from patients diagnosed with schizophrenia through proteomic analysis (n = 5 schizophrenia and n = 5 control). We found the presence of the Kv1.3 voltage-gated potassium channel and its auxiliary subunit ß1 (KCNAB1) and ß2 (KCNAB2). From a sample of 90 participants, we carried out a study on lymphocytes with whole-cell patch-clamp experiments (n = 7 schizophrenia and n = 5 control), western blot (n = 40 schizophrenia and n = 40 control) and confocal microscopy to evaluate the presence and function of different channels. Kv in both cells. RESULTS: We demonstrated the overexpression of Kv1.1, Kv1.2, Kv1.3, Kv1.6, Kv4.2, Kv4.3 and Kv7.2 channels in PBMCs from patients with schizophrenia. This study represents a groundbreaking exploration, as it involves an electrophysiological analysis performed on T and B lymphocytes from patients diagnosed of schizophrenia compared to healthy participants. We observed that B lymphocytes exhibited an increase in output current along with greater peak current amplitude and voltage conductance curves among patients with schizophrenia compared with healthy controls. CONCLUSIONS: This study showed the importance of the B lymphocyte in schizophrenia. We know that the immune system is altered in schizophrenia, but the physiological mechanisms of this system are not very well known. We suggest that the B lymphocyte may be relevant in the pathophysiology of schizophrenia and that it should be investigated in more depth, opening a new field of knowledge and possibilities for new treatments combining antipsychotics and immunomodulators. The limitation is that all participants received antipsychotic medication, which may have influenced the differences observed between patients and controls. This implies that more studies need to be done where the groups can be separated according to the antipsychotic drug.

7.
Food Chem Toxicol ; 191: 114845, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38945390

RESUMEN

Real-life pollution usually involves simultaneous co-exposure to different chemicals. Metals and drugs are frequently and abundantly released into the environment, where they interact and bioaccumulate. Few studies analyze potential interactions between metals and pharmaceuticals in these mixtures, although their joint effects cannot be inferred from their individual properties. We have previously demonstrated that the mixture (PC) of the metals Cd and Hg, the metalloid As and the pharmaceuticals diclofenac (DCF) and flumequine (FLQ) impairs hepatic proteostasis. To gain a deeper vision of how PC affects mouse liver homeostasis, we evaluated here the effects of PC exposure upon some biochemical and morphometric parameters, and on the transcriptional profiles of selected group of genes. We found that exposure to PC caused oxidative damage that exceeded the antioxidant capacity of cells. The excessive oxidative stress response resulted in an overabundance of reducing equivalents, which hindered the metabolism and transport of metabolites, including cholesterol and bile acids, between organs. These processes have been linked to metabolic and inflammatory disorders, cancer, and neurodegenerative diseases. Therefore, our findings suggest that unintended exposure to mixtures of environmental pollutants may underlie the etiology of many human diseases. Fortunately, we also found that a diet enriched with selenium mitigated the harmful effects of this combination of toxicants.

8.
J Clin Med ; 13(11)2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38893029

RESUMEN

Introduction: This report investigates late-stage internal derangement (ID) of the temporomandibular joint (TMJ) with the aim of establishing a more effective and personalized treatment protocol to improve patients' quality of life (QoL). Material and methods: A consensus was reached among maxillofacial surgeons specializing in LSID, based on a literature research and collective expert experience following the Delphi method. Consensus was considered to be achieved when a response received at least 80% of votes. Results: Four expert groups were established, respectively, focusing on diagnosis, minimally invasive surgery (MIS), open surgery and joint replacement. A comprehensive approach to late-stage ID of the TMJ requires a consensus report. This underscores the need for a personalized treatment plan, considering the variability in clinical presentations and progression of this pathology. Our recommendations aim to optimize clinical outcomes and enhance patient QoL.

9.
Diagnostics (Basel) ; 14(11)2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38893669

RESUMEN

BACKGROUND: Parkinson's disease (PD) is an advancing neurodegenerative disorder characterized by spinal anomalies and muscular weakness, which may restrict daily functional capacities. A gender-focused examination of these effects could provide valuable insights into customized rehabilitation strategies for both sexes. PURPOSE: This study investigates the influence of spinal alignment on lower-limb function during the sit-to-stand (STS) movement in patients with Parkinson's disease compared to healthy individuals. METHODS: A cross-sectional study was conducted with 43 consecutive patients with PD (25 males and 18 females; average age 73.7 ± 7.1 years) and 42 healthy controls (22 males and 20 females; average age 69.8 ± 6.0 years). Assessments included the International Physical Activity Questionnaire (IPAQ), Hoehn and Yahr staging, and measurements of vertical deviations from several spinal landmarks. Lower-limb muscle power during the STS task was evaluated using the Muscle Quality Index (MQI). RESULTS: Both absolute (Watts) and relative (Watts/Kg) muscle power in the lower limbs were notably decreased in the PD group compared to the control group. Within the PD cohort, muscle power showed a negative relationship with age and a positive association with the degree of lumbar lordosis (PL-L3). Importantly, gender-specific analysis revealed that male patients with PD had significantly higher lower-limb muscle power compared to female patients with PD, highlighting the need for gender-tailored therapeutic approaches. CONCLUSIONS: The findings suggest that preserving lumbar lordosis is crucial for maintaining effective lower-limb muscle biomechanics in individuals with Parkinson's disease.

10.
Biopolymers ; : e23585, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847141

RESUMEN

The pollution caused by petroleum-derived plastic materials has become a major environmental problem that has encouraged the development of new compostable and environmentally friendly materials for food packaging based on biomodified polymers with household residues. This study aims to design, synthesize, and characterize a biobased polymeric microstructure film from polyvinyl alcohol and chitosan reinforced with holocellulose from spent coffee grounds for food-sustainable packaging. Chemical isolation with a chlorite-based solution was performed to obtain the reinforced holocellulose from the spent coffee ground, and the solvent casting method was used to obtain the films to study. Physicochemical and microscopic characterizations were conducted to identify and select the best formulations using a simplex-centroid design analysis. The response surface methodology results indicate that the new packaging material obtained with equal amounts of polymers and reinforced material (1:1:1) possesses the appropriate barrier properties and microstructural character to prevent water attack and hydrophobic behavior and thus could be used as an alternative for food packaging materials.

12.
Nucleic Acids Res ; 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38850156

RESUMEN

Alu elements are non-autonomous Short INterspersed Elements (SINEs) derived from the 7SL RNA gene that are present at over one million copies in human genomic DNA. Alu mobilizes by a mechanism known as retrotransposition, which requires the Long INterspersed Element-1 (LINE-1) ORF2-encoded protein (ORF2p). Here, we demonstrate that HeLa strains differ in their capacity to support Alu retrotransposition. Human Alu elements retrotranspose efficiently in HeLa-HA and HeLa-CCL2 (Alu-permissive) strains, but not in HeLa-JVM or HeLa-H1 (Alu-nonpermissive) strains. A similar pattern of retrotransposition was observed for other 7SL RNA-derived SINEs and tRNA-derived SINEs. In contrast, mammalian LINE-1s, a zebrafish LINE, a human SINE-VNTR-Alu (SVA) element, and an L1 ORF1-containing mRNA can retrotranspose in all four HeLa strains. Using an in vitro reverse transcriptase-based assay, we show that Alu RNAs associate with ORF2p and are converted into cDNAs in both Alu-permissive and Alu-nonpermissive HeLa strains, suggesting that 7SL- and tRNA-derived SINEs use strategies to 'hijack' L1 ORF2p that are distinct from those used by SVA elements and ORF1-containing mRNAs. These data further suggest ORF2p associates with the Alu RNA poly(A) tract in both Alu-permissive and Alu-nonpermissive HeLa strains, but that Alu retrotransposition is blocked after this critical step in Alu-nonpermissive HeLa strains.

14.
Scand J Psychol ; 2024 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-38824420

RESUMEN

INTRODUCTION: This study explores how empowering human resource management (HRM) practices based on structural empowerment (access to opportunities, resources, support, and information) affect both personal initiative and job satisfaction of service employees through individual-level factors (psychological empowerment). METHODS: We conducted a cross-sectional survey study and collected 439 valid responses from service employees in Spain. The hypotheses were tested using structural equation modeling (SEM) with confidence intervals based on 10,000 resamples (i.e., bootstrapping technique). RESULTS: Our results showed that psychological empowerment partially mediated the relationship between structural empowerment and job satisfaction. It also fully mediated the relationship between structural empowerment and personal initiative at work. CONCLUSION: These findings emphasize the importance of HRM practices that can empower employees as key determinants of job satisfaction and personal initiative at service companies. Furthermore, a structural empowerment approach is a valid theoretical framework for studying and understanding employees' affective evaluations of work and, more specifically, their personal initiative.

15.
Artículo en Inglés | MEDLINE | ID: mdl-38897897

RESUMEN

OBJECTIVE: To evaluate the effect of selective decontamination of the digestive tract (SDD) on hospital-acquired infections (HAIs) in patients with acute burn injury requiring admission to a Burns Unit (BU). DESIGN: Retrospective before-and-after cohort study, between January 2017 and June 2023. SDD was implemented in March 2019, dividing patients into two groups. SETTING: Four-bed BU, in a referral University Hospital in Spain. PATIENTS: All the patients admitted during the study period were eligible for analysis. Patients who died or were discharged within 48hours of admission, and patients with an estimated survival less than 10% not considered for full escalation of therapy were excluded. INTERVENTION: SDD comprised the administration of a 4-day course of an intravenous antibiotic, and an oral suspension and oral topical paste of non-absorbable antibiotics during the stay in the BU. MAIN VARIABLE OF INTEREST: Incidence of HAIs during the stay in the BU. SECONDARY OUTCOMES: incidence of specific types of infections by site (bacteremia, pneumonia, skin and soft tissue infection) and microorganism (Gram-positive, Gram-negative, fungi), and safety endpoints. RESULTS: We analyzed 72 patients: 27 did not receive SDD, and 45 received SDD. The number of patients who developed HAIs were 21 (77.8%) and 21 (46.7%) in the non-SDD and the SDD groups, respectively (p=0.009). The number of hospital-acquired infectious episodes were 2.52 (1.21-3.82) and 1.13 (0.54-1.73), respectively (p=0.029). CONCLUSIONS: SDD was associated with a reduced incidence of bacterial HAIs and a decrease in the number of infectious episodes per patient.

16.
Artículo en Inglés | MEDLINE | ID: mdl-38940985

RESUMEN

PURPOSE: To investigate the patient reported outcomes (PROs) of patients undergoing hip arthroscopy (HA) for femeroacetabular impingement syndrome (FAIS), a condition where irregular bone growth in the hip joint leads to friction and pain during movement, who have worker's compensation (WC) or no-fault insurance (NF) versus commercial insurance (CI) at both 2 year and 5 year follow-up. METHODS: This was a single center, single surgeon, retrospective analysis performed between August 2007 and May 2023 of consecutive patients that underwent HA, a minimally invasive surgical procedure used to diagnose and treat problems inside the hip joint through small incisions, for FAIS. Patients were divided into two cohorts-those with WC/NF and those with commercial insurance (CI). Patient reported outcomes (PROs), which included modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS), were collected preoperatively, as well as at least 2-year postoperatively. Additionally, other clinically relevant outcomes variables including prevalence of revision surgery and conversion to total hip arthroplasty were recorded. RESULTS: Three hundred and forty three patients met inclusion criteria. There were 32 patients in the WC/NF cohort and 311 patients in the commercial cohort. When controlling for age, sex, and Body Mass Index (BMI), WC/NF status was associated with lower mHHS at both 2 year (ß = - 8.190, p < 0.01, R2 = 0.092) and 5 year follow-up (ß = - 16.60, p < 0.01, R2 = 0.179) and NAHS at 5 year follow up (ß = - 13.462, p = 0.03, R2 = 0.148). The WC/NF cohort had a lower rate of achieving Substantial Clinical Benefit (SCB) for mHHS at 2-years follow-up (66.7% vs. 84.1%, p = 0.02).The rate of revision hip arthroscopy was significantly higher in the worker's compensation/no fault cohort than the commercial insurance cohort (15.6% vs. 3.5%, p < 0.01). The rate of conversion to total hip arthroplasty (THA) in the WC/NF cohort was not significantly different than the rate of conversion to THA in the commercial insurance cohort (0.0% vs. 3.2%, p = 0.30). CONCLUSION: Patients with WC/NF insurance may expect a significant improvement from baseline mHHS and NAHS following HA for FAIS at short-term follow-up. However, this improvement may not be as durable as those experienced by patients with CI. Additionally, WC/NF patients should be counseled that they have a higher risk of undergoing revision hip arthroscopy than similar CI patients. LEVEL OF EVIDENCE: III, Retrospective Comparative Prognostic Investigation.

17.
Respir Res ; 25(1): 260, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38926693

RESUMEN

BACKGROUND: The PI*S variant is one of the most prevalent mutations within alpha-1 antitrypsin deficiency (AATD). The risk of developing AATD-related lung disease in individuals with the PI*SS genotype is poorly defined despite its substantial prevalence. Our study aimed to characterize this genotype and its risk for lung disease and compare it with the PI*ZZ and PI*SZ genotypes using data from the European Alpha-1 antitrypsin Deficiency Research Collaboration international registry. METHOD: Demographic, clinical, functional, and quality of life (QoL) parameters were assessed to compare the PI*SS characteristics with the PI*SZ and PI*ZZ controls. A propensity score with 1:3 nearest-neighbour matching was performed for the most important confounding variables. RESULTS: The study included 1007 individuals, with PI*SS (n = 56; 5.6%), PI*ZZ (n = 578; 57.4%) and PI*SZ (n = 373; 37.0%). The PI*SS population consisted of 58.9% men, with a mean age of 59.2 years and a mean FEV1(% predicted) of 83.4%. Compared to PI*ZZ individuals they had less frequent lung disease (71.4% vs. 82.2%, p = 0.037), COPD (41.4% vs. 60%, p = 0.002), and emphysema (23.2% vs. 51.9%, p < 0.001) and better preserved lung function, fewer exacerbations, lower level of dyspnoea, and better QoL. In contrast, no significant differences were found in the prevalence of lung diseases between PI*SS and PI*SZ, or lung function parameters, exacerbations, dyspnoea, or QoL. CONCLUSIONS: We found that, as expected, the risk of lung disease associated with the PI*SS genotype is significantly lower compared with PI*ZZ, but does not differ from that observed in PI*SZ individuals, despite having higher serum AAT levels. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (ID: NCT04180319).


Asunto(s)
Genotipo , Deficiencia de alfa 1-Antitripsina , alfa 1-Antitripsina , Humanos , Masculino , Femenino , Persona de Mediana Edad , alfa 1-Antitripsina/genética , Deficiencia de alfa 1-Antitripsina/genética , Deficiencia de alfa 1-Antitripsina/epidemiología , Deficiencia de alfa 1-Antitripsina/diagnóstico , Anciano , Enfermedades Pulmonares/genética , Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/diagnóstico , Factores de Riesgo , Sistema de Registros , Calidad de Vida
18.
Animals (Basel) ; 14(12)2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38929451

RESUMEN

Fasciolosis is an important economic disease of livestock. There is a global interest in the development of protective vaccines since the current anthelmintic therapy is no longer sustainable. A better knowledge of the host-parasite interaction is needed to design effective vaccines. To date, few studies have evaluated host-parasite interaction by comparing infected and reinfected animals. The present study evaluates the microscopical hepatic lesions in sheep infected and reinfected with Fasciola hepatica during the acute and chronic stages of infection. The histopathological study revealed the presence of necrotizing foci (NF1) associated with larvae migration during the early stages of infection in the primoinfected (PI) and reinfected (RI) groups. In the late stages of infection of the PI group and at the early and late stages of infection in the RI groups, extensive necrotizing/hemorrhagic foci (NF2) were found in the vicinity of enlarged bile ducts, some containing adult flukes, suggesting parasites may have caused NF2 while feeding. The immunohistochemical study revealed an increase in Foxp3+ T cells in both PI and RI groups with respect to the UC group and in the infiltrates adjacent to NF1 in the RI groups with respect to the PI group, suggesting the F. hepatica induce Foxp3 T cell expansion to facilitate parasite survival. In addition, in both the PI and RI groups, and during acute and chronic stages of the infection, a poor expression of iNOS was found accompanied by a strong expression of CD163, suggesting a marked M2 activation of macrophages in the hepatic lesions, which may be related with healing processes, and it also may facilitate parasite survival. The main differences between PI and RI animals were the more severe infiltration of eosinophils and Foxp3+ T cells, whereas RI did not modify M2 activation of macrophages which occurs since the early stages of primoinfection.

19.
Saudi J Biol Sci ; 31(6): 104000, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38706720

RESUMEN

Fluorescence is used in various biological assays due to its high sensitivity, versatility, and precision. In recent years, studies using medicinal plant extracts have increased. However, fluorescence-based assays could be biased by plant metabolites autofluorescence. To address this issue, this study investigated the interference caused by methanolic extracts and chloroform fractions of three medicinal plants in three fluorescence-based assays on gastric cancer stem cells(CSC): resazurin reduction, confocal microscopy, and flow cytometry. CSC were isolated based on CD44 surface marker, incubated with methanolic extracts and chloroform fractions of Buddleja incana, Dracontium spruceanum, Piper aduncum. Resazurin assay evidenced that CSC exposed to extracts and fractions from the three plants showed significant differences in relative fluorescence units (RFU) levels (p < 0.001) compared to the unexposed groups after a 3-hour incubation. In addition, DMSO-treated CSC exposed to extracts and fractions had significantly lower fluorescence levels than living ones, but higher than extracts and fractions without cells. In confocal microscopy, cancer stem cells exposed to extracts and fractions of B. incana and P. aduncum were observed in the same emission spectra of the CSC markers. In flow cytometry, CSC exposed to extracts and fractions without any fluorescent dyes were detected in the double positive quadrants for CSC markers (CD44+/CD133 + ). Among the three plants, D. spruceanum exhibited the least interference. These results show that methanolic extracts and chloroform fractions contain autofluorescent metabolites that interfere with fluorescence-based assays. These results highlight the importance of a prior evaluation for possible fluorescence interference to avoid interpretation biases in fluorescence assays.

20.
Materials (Basel) ; 17(9)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38730767

RESUMEN

Zirconia-reinforced lithium silicate (ZLS) is utilized as a material for prosthetic tooth crowns, offering enhanced strength compared to other dental glass-ceramics. In this study, we investigate a commercial ZLS material, provided in a fully crystallized form. We examine the effects of an optional post-processing heat treatment on micro-contact damage using controlled indentation tests simulating the primary modes of contact during chewing: axial and sliding. Our findings indicate that the heat treatment does not affect mechanical properties such as the elastic modulus, hardness and indentation fracture toughness. However, it does enhance the resistance to contact damage by fracture and chipping in both axial and sliding modes, as well as the resistance to crack initiation measured from sliding tests. This improvement is attributed to the refinement of the flaw population achieved through the heat treatment. The results are analysed using principles of contact and fracture mechanics theory, discussing their significance in prosthetic dentistry.

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