Acute myocardial infarction after inactivated COVID-19 vaccination: a case report and literature review.

A number of vaccines have been developed and deployed globally to restrain the spreading of the coronavirus disease 2019 (COVID-19). The adverse effect following vaccination is an important consideration. Acute myocardial infarction (AMI) is a kind of rare adverse event after COVID-19 vaccination. Herein, we present a case of an 83-year-old male who suffered cold sweat ten minutes after the first inactivated COVID-19 vaccination and AMI one day later. The emergency coronary angiography showed coronary thrombosis and underlying stenosis in his coronary artery. Type II Kounis syndrome might be a potential mechanism, which is manifested as coronary thrombosis secondary to allergic reactions in patients with underlying asymptomatic coronary heart disease. We also summarize the reported AMI cases post COVID-19 vaccination, as well as overview and discuss the proposed mechanisms of AMI after COVID-19 vaccination, thus providing insights for clinicians to be aware of the possibility of AMI following COVID-19 vaccination and potential underlying mechanisms.

Distribution and Speciation of Heavy Metal(loid)s in Soils under Multiple Preservative-Treated Wooden Trestles.

The widespread use of wood preservatives, such as chromated copper arsenate (CCA), alkaline copper quaternary (ACQ), and copper azole (CA), may cause environmental pollution problems. Comparative studies on the effect of CCA-, ACQ-, and CA-treated wood on soil contamination are rarely reported, and the behavior of soil metal(loid) speciation affected by preservatives has been poorly understood. Soils under the CCA-, ACQ-, and CA-treated boardwalks were collected to investigate metal(loid) distribution and speciation at the Jiuzhaigou World Natural Heritage site. The results showed that the maximum mean concentrations of Cr, As, and Cu were found in soils under the CCA, CCA, and CCA plus CA treatments and reached 133.60, 314.90, and 266.35 mg/kg, respectively. The Cr, As, and Cu contamination in soils within a depth of above 10 cm was high for all types of boardwalks and limited in the horizontal direction, not exceeding 0.5 m. Cr, As, and Cu in soils were mainly present as residual fractions in all profiles and increased with depth. The proportion of non-residual As in soil profiles under CCA- and CCA plus CA-treatment and exchangeable Cu in CA- and CCA plus CA-treatment were significantly higher than those in the profiles under the other preservative treatments. The distribution and migration of Cr, As, and Cu within soils were influenced by the preservative treatment of trestles, in-service time of trestles, soil properties (e.g., organic matter content), geological disasters (e.g., debris flow), and elemental geochemical behavior. With the CCA treatment for trestles successively replaced by ACQ and CA treatments, the types of contaminants were reduced from a complex of Cr, As, and Cu to a single type of Cu, achieving a reduction in total metal content, toxicity, mobility, and biological effectiveness, thus reducing environmental risks.

Short- and long-term impacts of the COVID-19 epidemic on urban PM2.5 variations: Evidence from a megacity, Chengdu.

As the new coronavirus pandemic enters its third year, its long-term impact on the urban environment cannot be ignored, especially in megacities with more than millions of people. Here, we analyzed the changes in the concentration levels, emission sources, temporal variations and holiday effects of ambient fine particulate matter (PM2.5) and its chemical components in the pre- and post-epidemic eras based on high-resolution, long time-series datasets of PM2.5 and its chemical components in Chengdu. In the post-epidemic era, the PM2.5 concentration in Chengdu decreased by 7.4%, with the components of PM2.5 decreasing to varying degrees. The positive matrix factorization (PMF) results indicated that the emissions from soil dust and industrial production were significantly lower during the COVID-19 lockdown period and post-epidemic era than those in the pre-epidemic era. In contrast, the contribution of secondary aerosols to PM2.5 during these two periods increased by 2.7% and 6.6%, respectively. Notably, we found that PM2.5 and its components substantially decreased on workdays and holidays in the post-epidemic era due to the reduced traffic volume and outdoor activities. This provides direct evidence that changes in the habitual behavior patterns of urban residents in the post-epidemic era could exert an evident positive impact on the urban environment. However, the higher PM2.5 concentration was observed due to the increased consumption of regular (As4S4, Xionghuang in Chinese) and "sulfur incense" during the Dragon Boat Festival holiday in the post-epidemic era. Finally, we examined the potential effects of sporadic COVID-19 outbreaks on the PM2.5 concentration in Chengdu, and there was no decrease in PM2.5 during two local COVID-19 outbreak events due to the strong influence of secondary pollution processes.

Breast myeloid sarcoma presenting as a palpable breast lump after allogeneic stem cell transplantation for acute myelomonocytic leukemia: a rare case report.

BACKGROUND: Myeloid sarcoma (MS) is a tumor secondary to myeloid leukemia that consists of immature granulocytes with or without mature granulocytes and is a rare extramedullary manifestation of acute myeloid leukemia (AML). CASE PRESENTATION: We report a case of a 34-year-old woman diagnosed with AML-M4 who achieved remission after chemotherapy and received allogeneic stem cell transplantation (allo-SCT) for consolidation. Her past medical history showed that she received bilateral breast implants 7 years ago. This patient underwent ultrasound examination of the breast and multiple bilateral breast nodules were revealed that were not considered by clinicians to be concerning. Several months later, the patient's bilateral nodules rapidly progressed to large palpable masses. Ultrasound-guided biopsy revealed diffuse infiltration of undifferentiated tumor cells and immunohistochemistry (IHC) indicated that the tumor was positive for myeloperoxidase (MPO), cluster of differentiation (CD) 34, CD43, CD68, CD117, and Ki67. The pathological diagnosis was extramedullary recurrence of AML as MS of breast. After the diagnosis, the patient received systemic chemotherapy and drugs containing cytarabine, azacitidine, and methotrexate. However, 1 year after achieving partial remission, the patient died from intracranial invasion of leukemia, brain herniation, and respiratory failure. CONCLUSION: It is necessary for the specialist to have a high suspicion index by careful inquiry of the patient's medical history if a patient presents at the breast clinic with a breast tumor as the chief complaint. Combining information from the patient's medical history with a tumor biopsy is critical for obtaining the correct diagnosis of the disease.

Circular RNA circWDR27 Promotes Papillary Thyroid Cancer Progression by Regulating miR-215-5p/TRIM44 Axis.

PURPOSE: This study was to explore the biological roles and underlying mechanism of circRNA WD repeat domain 27 (circWDR27). METHODS: The expression of circWDR27, microRNA-215-5p (miR-215-5p) and tripartite motif containing 44 (TRIM44) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays were employed to detect cell proliferation. Flow cytometry was used to determine cell apoptosis and cell cycle distribution. Cell migration and invasion abilities were examined by wound healing and transwell assays. The protein levels of matrix metalloproteinase 2 (MMP2), MMP9 and TRIM44 were analyzed by Western blot assay. The relationship between miR-215-5p and circWDR27 or TRIM44 was predicted by bioinformatics tools and confirmed using dual-luciferase reporter assay. Mouse xenograft model was established to examine the role of circWDR27 in vivo. RESULTS: CircWDR27 and TRIM44 were highly expressed while miR-215-5p was lowly expressed in PTC tissues and cells. Knockdown of circWDR27 suppressed cell proliferation and metastasis and induced cell cycle arrest and apoptosis in PTC cells. Moreover, miR-215-5p was a direct target of circWDR27, and its inhibition reversed the suppressive effect of circWDR27 knockdown on PTC cell progression. In addition, miR-215-5p directly targeted TRIM44, and miR-215-5p exerted its anti-cancer role in PTC cells by targeting TRIM44. Furthermore, circWDR27 positively regulated TRIM44 expression by sponging miR-215-5p. Importantly, knockdown of circWDR27 suppressed tumor growth in vivo by upregulating miR-215-5p and downregulating TRIM44. CONCLUSION: CircWDR27 accelerates PTC progression via regulating miR-215-5p/TRIM44 axis, providing a potential therapeutic target for PTC.

Heavy metal distribution in particle size fractions of floodplain soils from Dongchuan, Yunnan Province, Southwest China.

The heavy metal pollution level in soils is heavily affected by the soil particle size distribution. However, the heavy metal loss during particle size extraction and the effect of calcite on the heavy metals removal in terms of the particle size are unclear. In this study, the distribution of heavy metals (Cu, Cd, Cr, Co, Ni, Zn, Pb, U, and V) was determined in five particle fractions (> 2, 2-0.25, 0.25-0.02, 0.02-0.002, and < 0.002 mm) of two soil and one sediment samples collected from the floodplain of Dongchuan, Yunnan Province, Southwest China. The sampled floodplain soils were mainly composed of gravel and sand fractions (> 97%). The concentrations of all nine heavy metals in the sampled soils and sediment increase significantly with decreasing particle sizes. The maximal loss rate of Cd and Cu reaches 54% and 8.6%, respectively, which should be considered in the process of particle size fraction extraction in soils. The removal amount and removal rate of heavy metals in solution by pure calcite ranks in the order of Pb2+ > Cu2+ > Cr6+, while the removal rate of Pb (93.13%) is much higher than that of Cu (24.56%) and Cr (10.71%), which increase with the calcite particle size decreasing. The stabilization of carbonate minerals in soils is crucial for heavy metal pollution control in floodplain soils with high carbonate concentrations in Dongchuan, China.

Overexpression of CTRP9 attenuates the development of atherosclerosis in apolipoprotein E-deficient mice.

This study was aimed to explore the role of C1q/TNF-related protein 9 (CTRP9) on atherosclerotic lesion formation. A recombinant lentiviral vector carrying mouse CTRP9 (Lv-CTRP9) was injected intravenously into apolipoprotein E knockout (ApoE-/-) mice given a high-fat diet (HFD). CTRP9 overexpression substantially attenuated atherosclerotic lesion size of mice. The accumulation of macrophages and smooth muscle cells (SMCs) was significantly decreased in atherosclerotic regions with CTRP9 overexpression by immunohistochemical analysis. In addition, CTRP9 downregulated the expressions of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-α), two main proinflammatory cytokines in atherosclerosis. Furthermore, the autophagy level remarkably increased which was presented by microtubule-associated protein light chain 3B (LC3B) conversion and sequestosome 1 (SQSTM1/p62) degradation. Further study showed that CTRP9 increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased mammalian target of rapamycin (mTOR) phosphorylation in vivo. These observations reveal that CTRP9 exerts a protecting role in early atherosclerotic lesions and its anti-atherosclerotic effect is associated with autophagy induction through AMPK/mTOR signaling pathway.

SIRT3-KLF15 signaling ameliorates kidney injury induced by hypertension.

Renal fibrosis participates in the progression of hypertension-induced kidney injury. The effect of SIRT3, a member of the NAD+-dependent deacetylase family, in hypertensive nephropathy remains unclear. In this study, we found that SIRT3 was reduced after angiotensin II (AngII) treatment both in vivo and in vitro. Furthermore, SIRT3-knockout mice aggravated hypertension-induced renal dysfunction and renal fibrosis via chronic AngII infusion (2000 ng/kg per minute for 42 days). On the contrary, SIRT3-overexpression mice attenuated AngII-induced kidney injury compared with wild-type mice. Remarkably, a co-localization of SIRT3 and KLF15, a kidney-enriched nuclear transcription factor, led to SIRT3 directly deacetylating KLF15, followed by decreased expression of fibronectin and collagen type IV in cultured MPC-5 podocytes. In addition, honokiol (HKL), a major bioactive compound isolated from Magnolia officinalis (Houpo), suppressed AngII-induced renal fibrosis through activating SIRT3-KLF15 signaling. Taken together, our findings implicate that a novel SIRT3-KLF15 signaling may prevent kidney injury from hypertension and HKL can act as a SIRT3-KLF15 signaling activator to protect against hypertensive nephropathy.

Isoquercitrin protects against pulmonary hypertension via inhibiting PASMCs proliferation.

Pulmonary vascular remodelling is a common feature among the heterogeneous disorders that cause pulmonary arterial hypertension (PAH), and pulmonary arterial smooth muscle cells (PASMCs) proliferation impact the long-term prognosis of the patient. Isoquercitrin (IQC) is a flavonoid with anti-oxidative, anti-inflammatory and anti-proliferative activations. This study aimed to investigate whether IQC could prevent PASMCs proliferation and vascular remodelling in monocrotaline (MCT) induced PAH. Male Wistar rats were administered with Vehicle or 0.1% IQC maintain feed after MCT (40 mg/kg) injection. Haemodynamic changes, right ventricular hypertrophy and lung morphological features were assessed 3 weeks later. MCT-induced PAH, pulmonary vascular remodelling and PASMCs proliferation in Vehicle-treated rats. IQC reduced the right ventricle systolic pressure (RVSP), the ratio of RV/LV+S and the RV hypertrophy. IQC significantly alleviated the expression of proliferating cell nuclear antigen (PCNA), smooth muscle α-actin (α-SMA), and the percentage of fully muscularized small arterioles. In vitro studies, PASMCs were pretreated with IQC and stimulated with platelet-derived growth factor (PDGF)-BB (20 ng/mL). IQC suppressed PDGF-BB-induced PASMCs proliferation and caused G0/G1 phase cell cycle arrest. IQC downregulated the expression of Cyclin D1 and CDK4 as well as inhibited p27Kip1 degradation. Meanwhile, IQC negatively modulated PDGF-BB-induced phosphorylation of PDGF-Rß, Akt/GSK3ß and ERK1/2. IQC ameliorated MCT-induced pulmonary vascular remodelling via suppressing PASMCs proliferation and blocking PDGF-Rß signalling pathway.

Globular CTRP9 inhibits oxLDL-induced inflammatory response in RAW 264.7 macrophages via AMPK activation.

C1q-TNF-related protein-9 (CTRP9) is increasingly recognized as a promising cardioprotective adipocytokine, which regulates biological processes like vascular relaxation, proliferation, apoptosis, and inflammation. We recently showed that CTRP9 enhanced carotid plaque stability by reducing pro-inflammatory cytokines in macrophages. However, the underlying molecular mechanism of CTRP9 on anti-inflammatory response in macrophages still remains unclear. We demonstrated that globular CTRP9 (gCTRP9) significantly reduced oxidized low-density lipoprotein (oxLDL)-induced tumor necrosis factor alpha and monocyte chemoattractant protein 1 expression by suppressing nuclear factor-κB phosphorylation and nuclear translocation in RAW 264.7 macrophages. Treatment with gCTRP9 strikingly increased the level of phosphorylated adenosine monophosphate-activated protein kinase (AMPK). AMPK inhibitor abolished the anti-inflammatory effects of gCTRP9. Moreover, gCTRP9 increased the expression of adiponectin receptor 1 (AdipoR1). Downregulation of AdipoR1 by siRNA could abrogate the activation of AMPK and the anti-inflammatory effects of gCTRP9. These results suggested that gCTRP9 protected RAW 264.7 macrophages from oxLDL via AMPK activation in an AdipoR1 dependent fashion.

CTRP9 enhances carotid plaque stability by reducing pro-inflammatory cytokines in macrophages.

The aim of this study was to investigate whether C1q/TNF-related protein 9 (CTRP9) could stabilize the mature plaques by targeting macrophages in the apolipoprotein E knockout (ApoE KO) mice model. In vivo, the mice were subjected to high-fat diet and constrictive collars on the right carotid artery for eight weeks, a lentiviral vectors expressing CTRP9 (LV-CTRP9) or green fluorescence protein (LV-eGFP) as a control was intravenously injected into ApoE KO mice. Delivery of LV-CTRP9 resulted in low contents of macrophages and lipids, and high contents of collagen and vascular smooth muscle cells in the carotid mature plaques. In addition, CTRP9 also decreased pro-inflammatory cytokines in mature plaques. In vitro, RAW264.7 macrophages were pretreated with or without LV-CTRP9 transfection, and then stimulated with oxLDL (50 µg/mL). We found that the expression levels of tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) in the LV-CTRP9 group were significantly lower than those in the LV-eGFP group after exposure to oxLDL. The present data indicate that CTRP9 overexpression enhances the plaque stability in ApoE KO mice by reducing pro-inflammatory cytokines in macrophages. Our study suggests that the therapeutic approaches to enhance CTRP9 production could be valuable for plaque stabilization.

[Road traffic injuries in developing countries: research and action agenda]. / Traumatismos causados por el tránsito en países en desarrollo: agenda de investigación y de acción.

Road traffic injury (RTI) is the leading cause of death in persons aged 10-24 worldwide and accounts for about 15% of all male deaths. The burden of RTI is unevenly distributed amongst countries with over eighty-fold differences between the highest and lowest death rates. Thus the unequal risk of RTI occurring in the developing world, due to many reasons, including but not limited to rapid motorization and poor infrastructure, is a major global challenge. This editorial highlights a number of key issues that must inform programs designed to prevent RTI in the developing world, where the epidemic is all the more insidious. Firstly, road safety is a development issue; secondly, road traffic injury is a major health issue; thirdly, road traffic injuries can be prevented by the implementation of scientific measures; fourth, pre-hospital and hospital emergency care is needed; and fifth, research on RTI is neglected in low-income and middle-income countries. The repercussion of such progress to Peru is also discussed.

Web 2.0 and internet social networking: a new tool for disaster management?--lessons from Taiwan.

BACKGROUND: Internet social networking tools and the emerging web 2.0 technologies are providing a new way for web users and health workers in information sharing and knowledge dissemination. Based on the characters of immediate, two-way and large scale of impact, the internet social networking tools have been utilized as a solution in emergency response during disasters. This paper highlights the use of internet social networking in disaster emergency response and public health management of disasters by focusing on a case study of the typhoon Morakot disaster in Taiwan. DISCUSSION: In the case of typhoon disaster in Taiwan, internet social networking and mobile technology were found to be helpful for community residents, professional emergency rescuers, and government agencies in gathering and disseminating real-time information, regarding volunteer recruitment and relief supplies allocation. We noted that if internet tools are to be integrated in the development of emergency response system, the accessibility, accuracy, validity, feasibility, privacy and the scalability of itself should be carefully considered especially in the effort of applying it in resource poor settings. SUMMARY: This paper seeks to promote an internet-based emergency response system by integrating internet social networking and information communication technology into central government disaster management system. Web-based networking provides two-way communication which establishes a reliable and accessible tunnel for proximal and distal users in disaster preparedness and management.

Traumatismos causados por el tránsito en países en desarrollo: agenda de investigación y de acción / Road traffic injuries in developing countries: research and action agenda

Los traumatismos causados por el tránsito son la principal causa de muerte en personas de 10-24 años a nivel mundial y representan alrededor del 15% de todas las muertes en varones. La carga de enfermedad de los traumatismos causados por el tránsito está distribuida de manera desigual entre los países pues la tasa de mortalidad más alta es ochenta veces superior a las más baja. Existe una clara desigualdad en el riesgo de ocurrencia de traumatismos causados por el tránsito, siendo notoriamente mayor en los países en desarrollo. Esta desigualdad se constituye como un reto mundial importante y se debe, aunque no sean los únicos factores, a muchas razones, incluyendo la rápida motorización y la pobre infraestructura. Este artículo hace énfasis en varios aspectos fundamentales cuya finalidad es informar a los programas diseñados para prevenir los traumatismos causados por el tránsito en los países en desarrollo, donde esta situación está más extendida. En primer lugar, la seguridad vial es un tema de desarrollo; en segundo lugar, los traumatismos causados por el tránsito constituyen un problema importante para la salud; en tercer lugar, los traumatismos causados por el tránsito pueden ser prevenidos mediante la implementación de medidas científicas adecuadas; en cuarto lugar, es necesaria la atención de emergencias hospitalarias y prehospitalarias; y, finalmente, la investigación en los traumatismos causados por el tránsito está relegada en los países de ingresos bajos y medios. Se discute además la repercusión de estos avances para el Perú.

Road traffic injury (RTI) is the leading cause of death in persons aged 10-24 worldwide and accounts for about 15 per cent of all male deaths. The burden of RTI is unevenly distributed amongst countries with over eighty-fold differences between the highest and lowest death rates. Thus the unequal risk of RTI occurring in the developing world, due to many reasons, including but not limited to rapid motorization and poor infrastructure, is a major global challenge. This editorial highlights a number of key issues that must inform programs designed to prevent RTI in the developing world, where the epidemicis all the more insidious. Firstly, road safety is a development issue; secondly, road traffic injury is a major health issue; thirdly, road traffic injuries can be prevented by the implementation of scientific measures; fourthly, pre-hospital and hospital emergency care is needed; and fifthly, research on RTI is neglected in low-income and middle-income countries. The repercussion of such progress to Peru is also discussed.

[Research of morphology for the toothmark in pocket limb].

OBJECTIVE: The purpose of this study was to observe the morphological changes of toothmarks in pocket limbs and to explore the durative development of bitemarks. METHODS: Firstly a toothmark model was established by using a universal testing machine and a self-made incisor nod which was pressed particularly on pocket limbs. The changes of toothmarks were observed on alive and dead animals with time elapsing. The scopes of bruise and inden were analyzed by soft on digital photos. The depth data of inden were collected by three dimensional laser measurement. RESULTS: The changes in the alive group were faster than that in dead group. There was no obvious fadeaway of bruise during 24 h. The scopes of inden were decreased remarkably in 1 h, while the decrease slowed down in the following hours. CONCLUSION: The changes of indent are fast in pocket limb. It implies that bitemark evidence should be collected as fast as possible in cases.

[FTIR and XRD analysis of hydroxyapatite from fossil human and animal teeth in Jinsha Relict, Chengdu].

Diagenetic effect during burial on the hydroxyapatite in enamel and dentin from fossil human and animal teeth was examined, using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). For the enamel and dentin of all fossil teeth, XRD patterns exhibit bulge line and overlap between major reflections of hydroxyapatite, and the crystallinity of hydroxyapatite is low. For each infrared spectrum, H2O and OH(-) have distinct peaks of absorbance, and PO4(3-) and CO3(2-) ions have intensive infrared vibration modes at the fundamental wave numbers. The component of hydroxyapatite of all fossil teeth is similar to the modern biological hydroxyapatite. Furthermore, the index (PCI) which reflects the hydroxyapatite crystallinity of each sample ranges from 2.4 to 4.0 while the index (BPI) reflecting the amount of type B carbonate to phosphate indicates that the values of CO3(2-) content in hydroxyapatite are rather high, accordingly the crystallinity of all fossil hydroxyapatites are poor. It could be concluded that little alteration of hydroxyapatites from fossil human and animal teeth occurred in the process of diagenesis in Jinsha Relict, Chengdu, China.

[Cyclic fatigue of Vita mark II machinable ceramics under Hertzian's contact].

OBJECTIVE: To investigate the cyclic fatigue modes of Vita mark II machinable ceramics under Hertzian's contact. METHODS: Hertzian's contact technique (WC spheres r = 3.18 mm) was used to investigate the cyclic fatigue of Vita mark II machinable ceramic. All specimens were fatigued by cyclic loading in moist environment, furthermore, surviving strength was examined by three point test and morphology damage observation. RESULTS: In homogeneous Vita mark II machinable ceramics, two fatigue damage modes existed after cyclic loading with spheres under moist environment, including conventional tensile-driven cone cracking (brittle mode) and shear-driven microdamage accumulation (quasi-plastic mode). The latter generated radial cracks and deeply penetrating secondary cone crack. Initial strength degradation were caused by the cone cracks, subsequent and much more deleterious loss was caused by radial cracks. CONCLUSION: Cyclic fatigue modes of Vita mark II machinable ceramics includes brittle and quasi-plastic mode.

[A comparative study on cyclic and static fatigue of dental ceramic by means of Hertzian's contact].

OBJECTIVE: To compare the difference in strength degradation and morphology damage of brittle dental ceramic after static load and cyclic fatigue. METHODS: Hertzian's contact technique with a tungsten carbide sphere was used to investigate the response of feldspathic dental porcelain to static load and cyclic fatigue. All specimens were subjected to static or cyclic loading in moist environment. Furthermore the surviving strength of specimens was examined by the three-point test and the morphology damage was observed. Statistical analyses were performed with ANOVA and a P-value less than 0.05 was considered to be significant. RESULTS: Outer cone crack and associated strength degradation simultaneously occurred both after the first cyclic loading and static loading. Up to 1,000 cycles, the specimens showed inner cone cracks and strength degradation was aggravated. No significant difference in the strength degradation among all static loading specimens and no inner cone cracks occurred in static loading specimens. CONCLUSIONS: Both static and cyclic fatigue influence dental ceramic strength, but cyclic fatigue is more deleterious.