Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
1.
J Environ Sci (China) ; 149: 535-550, 2025 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39181665

RESUMO

Li6ZnO4 was chemically modified by nickel addition, in order to develop different compositions of the solid solution Li6Zn1-xNixO4. These materials were evaluated bifunctionally; analyzing their CO2 capture performances, as well as on their catalytic properties for H2 production via dry reforming of methane (DRM). The crystal structures of Li6Zn1-xNixO4 solid solution samples were determined through X-ray diffraction, which confirmed the integration of nickel ions up to a concentration around 20 mol%, meanwhile beyond this value, a secondary phase was detected. These results were supported by XPS and TEM analyses. Then, dynamic and isothermal thermogravimetric analyses of CO2 capture revealed that Li6Zn1-xNixO4 solid solution samples exhibited good CO2 chemisorption efficiencies, similarly to the pristine Li6ZnO4 chemisorption trends observed. Moreover, a kinetic analysis of CO2 isothermal chemisorptions, using the Avrami-Erofeev model, evidenced an increment of the constant rates as a function of the Ni content. Since Ni2+ ions incorporation did not reduce the CO2 capture efficiency and kinetics, the catalytic properties of these materials were evaluated in the DRM process. Results demonstrated that nickel ions favored hydrogen (H2) production over the pristine Li6ZnO4 phase, despite a second H2 production reaction was determined, methane decomposition. Thereby, Li6Zn1-xNixO4 ceramics can be employed as bifunctional materials.


Assuntos
Dióxido de Carbono , Hidrogênio , Metano , Hidrogênio/química , Metano/química , Dióxido de Carbono/química , Níquel/química , Catálise , Modelos Químicos
2.
Lancet Reg Health Am ; 38: 100863, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39258234

RESUMO

Background: Adrenocortical tumours (ACT) in children are part of the Li-Fraumeni cancer spectrum and are frequently associated with a germline TP53 pathogenic variant. TP53 p.R337H is highly prevalent in the south and southeast of Brazil and predisposes to ACT with low penetrance. Thus, we aimed to investigate whether genetic variants exist which are associated with an increased risk of developing ACT in TP53 p.R337H carrier children. Methods: A genetic association study was conducted in trios of children (14 girls, 7 boys) from southern Brazil carriers of TP53 p.R337H with (n = 18) or without (n = 3) ACT and their parents, one of whom also carries this pathogenic variant (discovery cohort). Results were confirmed in a validation cohort of TP53 p.R337H carriers with (n = 90; 68 girls, 22 boys) or without ACT (n = 302; 165 women, 137 men). Findings: We analysed genomic data from whole exome sequencing of blood DNA from the trios. Using deep learning algorithms, according to a model where the affected child inherits from the non-carrier parent variant(s) increasing the risk of developing ACT, we found a significantly enriched representation of non-coding variants in genes involved in the cyclic AMP (cAMP) pathway known to be involved in adrenocortical tumorigenesis. One among those variants (rs2278986 in the SCARB1 gene) was confirmed to be significantly enriched in the validation cohort of TP53 p.R337H carriers with ACT compared to carriers without ACT (OR 1.858; 95% CI 1.146, 3.042, p = 0.01). Interpretation: Profiling of the variant rs2278986 is a candidate for future confirmation and possible use as a tool for ACT risk stratification in TP53 p.R337H carriers. Funding: Centre National de la Recherche Scientifique (CNRS), Behring Foundation, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).

3.
AME Case Rep ; 8: 76, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39091538

RESUMO

Background: Li-Fraumeni syndrome (LFS) is a rare hereditary disorder caused by mutations in the tumor protein p53 (TP53). It causes a predisposition for the development of multiple malignancies, primarily including breast cancers, sarcomas, and central nervous system tumors. There are a few cases reported in the literature of patients with LFS presenting with an epidermal growth factor receptor (EGFR) mutated lung cancer. Still, it has been suggested that there may be an association between the TP53 pathogenic variant and lung cancer with EGFR mutation in somatic cells. Case Description: A 47-year-old non-smoker woman with LFS with a history of multiple tumors, including bilateral breast cancer, pecoma, and sarcoma. In one of her computed tomography, a lesion in the lingula of the lung was detected. It was biopsied, which diagnosed lung adenocarcinoma, and genetic studies detected an EGFR exon 19 deletion. She was treated with a left inferior lobectomy, followed by pemetrexed and cisplatin. Conclusions: The association between TP53 and lung cancer with EGFR mutation has been suggested in case reports. Studies in lung cancer cell lines have shown a link between TP53 mutation and EGFR overexpression. Nonetheless, as more cases are reported, further research is needed to comprehend the interrelation between these two pathologies and the risk posed by LFS to the emergence of EGFR-mutated lung cancer.

4.
Eur Radiol ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39075300

RESUMO

OBJECTIVES: Li-Fraumeni syndrome (LFS) is a cancer syndrome associated with early-onset neoplasias. The use of whole-body magnetic resonance imaging (WBMRI) is recommended for regular cancer screening, however, evidence supporting the benefits in asymptomatic LFS patients is limited. This study aims to assess the clinical utility of WBMRI in germline TP53 mutation carriers at baseline and follow-up. MATERIALS AND METHODS: We systematically searched PubMed, Cochrane, and Embase databases for studies evaluating WBMRI as an early detection method for tumor screening in patients with LFS. We pooled the prevalence of the included variables along with their corresponding 95% confidence intervals (CIs). Statistical analyses were performed using R software, version 4.3.1. RESULTS: From 1687 results, 11 comprising 703 patients (359 females (51%); with a median age of 32 years (IQR 1-74)) were included. An estimated detection rate of 31% (95% CI: 0.28, 0.34) for any suspicious lesions was found in asymptomatic TP53 carriers who underwent baseline WBMRI. A total of 277 lesions requiring clinical follow-up were identified in 215 patients. Cancer was confirmed in 46 lesions across 39 individuals. The estimated cancer diagnosis rate among suspicious lesions was 18% (95% CI: 0.13, 0.25). WBMRI detected 41 of the 46 cancers at an early-disease stage, with an overall detection rate of 6% (95% CI: 0.05, 0.08). The incidence rate was 2% per patient round of WBMRI (95% CI: 0.01, 0.04), including baseline and follow-up. CONCLUSION: This meta-analysis provides evidence that surveillance with WBMRI is effective in detecting cancers in asymptomatic patients with LFS. CLINICAL RELEVANCE STATEMENT: Our study demonstrates that whole-body MRI is an effective tool for early cancer detection in asymptomatic Li-Fraumeni Syndrome patients, highlighting its importance in surveillance protocols to improve diagnosis and treatment outcomes. KEY POINTS: Current evidence for whole-body MRI screening of asymptomatic Li-Fraumeni Syndrome (LFS) patients remains scarce. Whole-body MRI identified 41 out of 46 cancers at an early stage, achieving an overall detection rate of 6%. Whole-body MRI surveillance is a valuable method for detecting cancers in asymptomatic LFS patients.

5.
Sci Rep ; 14(1): 17187, 2024 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-39060302

RESUMO

Germline TP53 pathogenic variants can lead to a cancer susceptibility syndrome known as Li-Fraumeni (LFS). Variants affecting its activity can drive tumorigenesis altering p53 pathways and their identification is crucial for assessing individual risk. This study explored the functional impact of TP53 missense variants on its transcription factor activity. We selected seven TP53 missense variants (c.129G > C, c.320A > G, c.417G > T, c.460G > A, c,522G > T, c.589G > A and c.997C > T) identified in Brazilian families at-risk for LFS. Variants were created through site-directed mutagenesis and transfected into SK-OV-3 cells to assess their transcription activation capabilities. Variants K139N and V197M displayed significantly reduced transactivation activity in a TP53-dependent luciferase reporter assay. Additionally, K139N negatively impacted CDKN1A and MDM2 expression and had a limited effect on GADD45A and PMAIP1 upon irradiation-induced DNA damage. Variant V197M demonstrated functional impact in all target genes evaluated and loss of Ser15 phosphorylation. K139N and V197M variants presented a reduction of p21 levels after irradiation. Our data show that K139N and V197M negatively impact p53 functions, supporting their classification as pathogenic variants. This underscores the significance of conducting functional studies on germline TP53 missense variants classified as variants of uncertain significance to ensure proper management of LFS-related cancer risks.


Assuntos
Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Síndrome de Li-Fraumeni , Mutação de Sentido Incorreto , Proteína Supressora de Tumor p53 , Síndrome de Li-Fraumeni/genética , Humanos , Proteína Supressora de Tumor p53/genética , Brasil , Proteínas Proto-Oncogênicas c-mdm2/genética , Feminino , Inibidor de Quinase Dependente de Ciclina p21/genética , Masculino , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Ativação Transcricional/genética , Proteínas GADD45
6.
Genes (Basel) ; 15(7)2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39062707

RESUMO

Despite the high prevalence of TP53 pathogenic variants (PV) carriers in the South and Southeast regions of Brazil, germline genetic testing for hereditary breast cancer (HBC) is not available in the Brazilian public health system, and the prevalence of Li-Fraumeni syndrome (LFS) is not well established in other regions of Brazil. We assessed the occurrence of TP53 p.R337H carriers among women treated for breast cancer (BC) between January 2021 and January 2022 at public hospitals of Brasilia, DF, Brazil. A total of 180 patients who met at least one of the NCCN criteria for HBC underwent germline testing; 44.4% performed out-of-pocket germline multigene panel testing, and 55.6% were tested for the p.R337H variant by allelic discrimination PCR. The median age at BC diagnosis was 43.5 years, 93% had invasive ductal carcinoma, 50% had estrogen receptor-positive/HER2 negative tumors, and 41% and 11% were diagnosed respectively at stage III and IV. Two patients (1.11%) harbored the p.R337H variant, and cascade family testing identified 20 additional carriers. The TP53 p.R337H detection rate was lower than that reported in other studies from south/southeast Brazil. Nonetheless, identifying TP53 PV carriers through genetic testing in the Brazilian public health system could guide cancer treatment and prevention.


Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Proteína Supressora de Tumor p53 , Humanos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/epidemiologia , Brasil/epidemiologia , Adulto , Proteína Supressora de Tumor p53/genética , Pessoa de Meia-Idade , Testes Genéticos/métodos , Saúde Pública , Síndrome de Li-Fraumeni/genética , Síndrome de Li-Fraumeni/epidemiologia , Idoso
7.
Toxics ; 12(3)2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38535909

RESUMO

The aim of this study was to evaluate the acute lethality and chronic sublethal effects of lithium (Li) on Rhinella arenarum tadpoles as model organisms. First a 96 h toxicity assay was performed by exposing tadpoles to Li concentrations from 44.08 to 412.5 mg L-1 to estimate the mortality, and lethal and sublethal effects. Another bioassay was carried out by exposing tadpoles to two environmentally relevant Li concentrations (2.5 and 20 mg L-1) for one and two weeks. The sublethal effects of Li on tadpoles were evaluated by analyzing biochemical, genotoxic, and physiological biomarkers. The mortality in Li-exposed tadpoles increased over time. The median lethal concentration (LC50) ranged from 319.52 (281.21-363.05) mg L-1 at 48 h to 66.92 (52.76-84.89) mg L-1 at 96 h. Exposure to Li at 2.5 and 20 mg L-1 induced alterations in enzymes related to detoxification, antioxidant, and hepatic mechanisms, endocrine disruption of thyroid hormones, genotoxicity, and effects on the physiology of the heart and gastrointestinal systems. Tadpoles exposed to the highest concentration in the chronic bioassay (20 mg L-1 Li), which is the concentration commonly recorded in Li mining sites, showed significant mortality after one week of exposure. These results warn about the high ecotoxicological risk of Li as a contaminant of emerging concern for amphibians.

8.
Heliyon ; 10(2): e24645, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38304793

RESUMO

Carbon capture, utilization, and storage (CCUS) technology offer promising solution to mitigate the threatening consequences of large-scale anthropogenic greenhouse gas emissions. Within this context, this report investigates the influence of NiO deposition on the Li4SiO4 surface during the CO2 capture process and its catalytic behavior in hydrogen production via dry methane reforming. Results demonstrate that the NiO impregnation method modifies microstructural features of Li4SiO4, which positively impact the CO2 capture properties of the material. In particular, the NiO-Li4SiO4 sample captured twice as much CO2 as the pristine Li4SiO4 material, 6.8 and 3.4 mmol of CO2 per gram of ceramic at 675 and 650 °C, respectively. Additionally, the catalytic results reveal that NiO-Li4SiO4 yields a substantial hydrogen production (up to 55 %) when tested in the dry methane reforming reaction. Importantly, this conversion remains stable after 2.5 h of reaction and is selective for hydrogen production. This study highlights the potential of Li4SiO4 both a support and a captor for a sorption-enhanced dry reforming of methane. To the best of our knowledge, this is the first report showcasing the effectiveness of Li4SiO4 as an active support for Ni-based catalysis in the dry reforming of methane. These findings provide valuable insights into the development of this composite as a dual-functional material for carbon dioxide capture and conversion.

9.
Hered Cancer Clin Pract ; 22(1): 1, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238849

RESUMO

BACKGROUND: Li-Fraumeni syndrome (LFS) is an autosomal dominant hereditary cancer syndrome caused by pathogenic variants in the gene TP53. This gene codes for the P53 protein, a crucial player in genomic stability, which functions as a tumor suppressor gene. Individuals with LFS frequently develop multiple primary tumors at a young age, such as soft tissue sarcomas, breast cancer, and brain tumors. CASE PRESENTATION: A 38 years-old female with a history of femur osteosarcoma, ductal carcinoma of the breast, high-grade breast sarcoma, pleomorphic sarcoma of the left upper limb, infiltrating lobular carcinoma of the breast, gastric adenocarcinoma, leiomyosarcoma of the right upper limb, and high-grade pleomorphic renal sarcoma. Complete molecular sequencing of the TP53 gene showed c.586 C > T (p.R196X) in exon 6, which is a nonsense mutation that produces a shorter and malfunctioning P53. Family history includes advanced father's age at the time of conception (75 years), which has been associated with an increased risk of de novo germline mutations. The patient had seven paternal half-siblings with no cancer history. The patient received multiple treatments including surgery, systemic therapy, and radiotherapy, but died at the age of 38. CONCLUSIONS: Advanced paternal age is a risk factor to consider when hereditary cancer syndrome is suspected. Early detection of hereditary cancer syndromes and their multi-disciplinary surveillance and treatment is important to improve clinical outcomes for these patients. Further investigation of the relationship between the pathogenic variant of TP53 and its phenotype may guide the stratification of surveillance and treatment.

10.
Int J Mol Sci ; 24(20)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37894716

RESUMO

In southern and southeastern Brazil, the TP53 founder variant c.1010G>A (R337H) has been previously documented with a prevalence of 0.3% within the general population and linked to a heightened incidence of lung adenocarcinomas (LUADs). In the present investigation, we cover clinical and molecular characterizations of lung cancer patients from the Brazilian Li-Fraumeni Syndrome Study (BLISS) database. Among the 175 diagnosed malignant neoplasms, 28 (16%) were classified as LUADs, predominantly occurring in females (68%), aged above 50 years, and never-smokers (78.6%). Significantly, LUADs manifested as the initial clinical presentation of Li-Fraumeni Syndrome in 78.6% of cases. Molecular profiling was available for 20 patients, with 14 (70%) revealing EGFR family alterations. In total, 23 alterations in cancer driver genes were identified, comprising 7 actionable mutations and 4 linked to resistance against systemic treatments. In conclusion, the carriers of TP53 R337H demonstrate a predisposition to LUAD development. Furthermore, our results indicate that environmental pollution potentially impacts the carcinogenesis of lung tumors in the carriers of TP53 R337H.


Assuntos
Adenocarcinoma de Pulmão , Síndrome de Li-Fraumeni , Neoplasias Pulmonares , Feminino , Humanos , Idoso , Síndrome de Li-Fraumeni/genética , Brasil/epidemiologia , Proteína Supressora de Tumor p53/genética , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Carcinogênese , Adenocarcinoma de Pulmão/genética , Células Germinativas/patologia
11.
Clin Transl Oncol ; 25(9): 2627-2633, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37133731

RESUMO

Li-Fraumeni syndrome is caused by heterozygous germline pathogenic variants in the TP53 gene. It involves a high risk of a variety of malignant tumors in childhood and adulthood, the main ones being premenopausal breast cancer, soft tissue sarcomas and osteosarcomas, central nervous system tumors, and adrenocortical carcinomas. The variability of the associated clinical manifestations, which do not always fit the classic criteria of Li-Fraumeni syndrome, has led the concept of SLF to extend to a more overarching cancer predisposition syndrome, termed hereditable TP53-related cancer syndrome (hTP53rc). However, prospective studies are needed to assess genotype-phenotype characteristics, as well as to evaluate and validate risk-adjusted recommendations. This guideline aims to establish the basis for interpreting pathogenic variants in the TP53 gene and provide recommendations for effective screening and prevention of associated cancers in carrier individuals.


Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Neoplasias Ósseas , Síndrome de Li-Fraumeni , Humanos , Síndrome de Li-Fraumeni/genética , Proteína Supressora de Tumor p53/genética , Carcinoma Adrenocortical/genética , Mutação em Linhagem Germinativa , Neoplasias do Córtex Suprarrenal/genética , Predisposição Genética para Doença
12.
Nanomaterials (Basel) ; 13(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36616107

RESUMO

The fabrication of NiO films by different routes is important to extend and improve their applications as hole-transporting layers in organic and inorganic optoelectronic devices. Here, an automated ultrasonic pyrolysis spray method was used to fabricate NiO and Li-doped NiO thin films using nickel acetylacetonate and lithium acetate dihydrate as metal precursor and dimethylformamide as solvent. The effect of the amount of lithium in the precursor solution on the structural, morphological, optical, and electrical properties were studied. XRD results reveal that all the samples are polycrystalline with cubic structure and crystallite sizes in the range of 21 to 25 nm, without any clear trend with the Li doping level. AFM analysis shows that the crystallites form round-shaped aggregates and all the films have low roughness. The optical transmittance of the films reaches values of 60% to 77% with tendency upward as Li content is increased. The electrical study shows that the films are p-type, with the carrier concentration, resistivity, and carrier mobility depending on the lithium doping. NiO:Li (10%) films were successfully incorporated into inorganic light emitting diodes together with Mn-doped ZnS and ZnO:Al films, all deposited on ITO by the same ultrasonic spray pyrolysis technique.

13.
J Med Case Rep ; 16(1): 468, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36529791

RESUMO

BACKGROUND: Leiomyosarcoma is a rare malignant tumor of smooth muscle origin and represents 10-20% of all soft tissue sarcomas. Primary colon and rectal sarcomas constitute < 0.1% of all large bowel malignancies. In Li-Fraumeni syndrome, sarcomas are the second most frequent cancer (25%). Li-Fraumeni syndrome is a genetic disease with a familial predisposition to multiple malignant neoplasms. This syndrome has an autosomal dominant pattern of inheritance and high penetrance characterized by germline TP53 mutations. Patients with a history of cancer who do not meet all the "classic" criteria for Li-Fraumeni syndrome are considered to have Li-Fraumeni-like syndrome. To the best of our knowledge, this article is the first report of a patient with rectal leiomyosarcoma as the initial phenotypic manifestation of Li-Fraumeni-like syndrome. The authors also present a literature review. CASE PRESENTATION: A 67-year-old Brazilian woman underwent anterior rectosigmoidectomy and panhysterectomy secondary to rectal leiomyosarcoma. She subsequently developed carcinomatosis and died 2 years after the operation. Her family medical history consisted of a daughter who died at 32 years of age from breast cancer, a granddaughter diagnosed with adrenocortical carcinoma at 6 years of age and two siblings who died from prostate cancer. A genetic study was carried out to identify a pathogenic variant of Li-Fraumeni syndrome. In the DNA extracted from the peripheral blood leukocyte, restriction fragment length polymorphism was analyzed to search for mutations in the TP53 gene. The DNA sequencing identified the germline pathogenic variant p. R337H heterozygous in exon 10 of TP53. The patient was classified as having Li-Fraumeni-like syndrome. CONCLUSION: In patients with rectal leiomyosarcoma, it is advisable to investigate the family history of cancer and perform genetic studies to screen for Li-Fraumeni syndrome.


Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Leiomiossarcoma , Síndrome de Li-Fraumeni , Neoplasias Pélvicas , Neoplasias Retais , Masculino , Feminino , Humanos , Criança , Idoso , Síndrome de Li-Fraumeni/complicações , Síndrome de Li-Fraumeni/diagnóstico , Síndrome de Li-Fraumeni/genética , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/genética , Leiomiossarcoma/cirurgia , Proteína Supressora de Tumor p53/genética , Neoplasias Retais/diagnóstico , Neoplasias Retais/genética , Neoplasias Retais/cirurgia , Neoplasias do Córtex Suprarrenal/complicações , Neoplasias do Córtex Suprarrenal/genética , Predisposição Genética para Doença
14.
ACS Appl Mater Interfaces ; 14(41): 47262-47271, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36205921

RESUMO

First-principles calculations within DFT have been performed to investigate the use of a recently synthesized form of silicene, the dumbbell (DB) silicene as an anode material for Li-ion batteries (LiBs). The energetically most stable geometries for Li adsorption on DB silicene were investigated, and the energy barriers for Li-ion diffusion among the possible stable adsorption sites were calculated. We found that DB silicene can be lithiated up to a ratio of 1.05 Li per Si atom, resulting in a high storage capacity of 1002 mA h g-1 and an average open-circuit potential of 0.38 V, which makes DB silicene suitable for applications as an anode in LiBs. The energy barrier for Li-ion diffusion was calculated to be as low as 0.19 eV, suggesting that the Li ions can easily diffuse on the entire DB silicene surface, decreasing the time for the charge/discharge process of the LiBs. Our detailed investigations show that the most stable form of two-dimensional silicon has characteristic features suitable for application in high-performance LiBs.

15.
Genes (Basel) ; 13(10)2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36292694

RESUMO

Frantz tumors or solid pseudopapillary pancreatic neoplasm (SPN) are rare exocrine neoplasms that carry a favorable prognosis; they represent up to 3% of all tumors located in the region of the pancreas and have specific age and gender predispositions. In recent years, the rising curve of diagnosis is entitled to the evolution and access of diagnostic imaging. In this paper, we have retrospectively reviewed and described the clinical course of 40 patients with SPN from three institutions in Brazil, who had their diagnosis between 2005 and 2020, and analyzed the clinicopathological, genetic, and surgical aspects of these individuals. In accordance with the literature, most patients were women, 60% with unspecified symptoms at diagnosis, with tumors mainly located in the body and tail of the pancreas, of whom 70% underwent a distal pancreatectomy with sparing splenectomy as a standard procedure, and none of the cases have experienced recurrence to date. Surgery still remains the mainstay of treatment given the low metastatic potential, but more conservative approaches as observed in this cohort are evolving to become the standard of care. Herein, we present an in-depth analysis of cases focusing on the latest literature and report some of the smallest tumor cases in the literature. To our knowledge, this is the first report evaluating germline genetic testing and presenting a case of detected Li-Fraumeni syndrome.


Assuntos
Neoplasias Pancreáticas , Humanos , Feminino , Masculino , Brasil , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/diagnóstico , Estudos Retrospectivos , Pancreatectomia/métodos , Pâncreas/patologia
16.
Materials (Basel) ; 15(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36234094

RESUMO

A facile and versatile process to produce lithium metasilicate (Li2SiO3) from non-conventional silicon sources (two different sand sources from the central area of México) was developed. The synthesis protocol based on a solid-state reaction followed by a hydrothermal treatment resulted in highly pure lithium metasilicate, as corroborated by XRD, SEM-EDS, and XPS analysis. Furthermore, lithium metasilicate was used as a heterogeneous catalyst for biodiesel production from soybean oil, where conversion yields were compared according to the silicon source used (based on chemical purity, stability, and yield efficiency). The best performing metasilicate material displayed a maximum of 95.5% of biodiesel conversion under the following conditions: 180 min, 60 °C, 5% catalyst (wt./wt., catalyst-to-oil), and 18:1 (methanol:oil). This contribution opens up alternatives for the production of lithium metasilicate using non-conventional precursors and its use as an alternative catalyst in biodiesel production, displaying better chemical stability against humidity than conventional heterogeneous catalysts.

17.
Sensors (Basel) ; 22(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36080844

RESUMO

In the last few years, the growing demand for electric vehicles (EVs) in the transportation sector has contributed to the increased use of electric rechargeable batteries. At present, lithium-ion (Li-ion) batteries are the most commonly used in electric vehicles. Although once their storage capacity has dropped to below 80-70% it is no longer possible to use these batteries in EVs, it is feasible to use them in second-life applications as stationary energy storage systems. The purpose of this study is to present an embedded system that allows a Nissan® LEAF Li-ion battery to communicate with an Ingecon® Sun Storage 1Play inverter, for control and monitoring purposes. The prototype was developed using an Arduino® microcontroller and a graphical user interface (GUI) on LabVIEW®. The experimental tests have allowed us to determine the feasibility of using Li-ion battery packs (BPs) coming from the automotive sector with an inverter with no need for a prior disassembly and rebuilding process. Furthermore, this research presents a programming and hardware methodology for the development of the embedded systems focused on second-life electric vehicle Li-ion batteries. One second-life battery pack coming from a Nissan® Leaf and aged under real driving conditions was integrated into a residential microgrid serving as an energy storage system (ESS).

18.
Biomolecules ; 12(5)2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35625568

RESUMO

TP53 gene mutation is the most common genetic alteration in human malignant tumors and is mainly responsible for Li-Fraumeni syndrome. Among the several cancers related to this syndrome, breast cancer (BC) is the most common. The TP53 p.R337H germline pathogenic variant is highly prevalent in Brazil's South and Southeast regions, accounting for 0.3% of the general population. We investigated the prevalence of TP53 germline pathogenic variants in a cohort of 83 BC patients from the Midwest Brazilian region. All patients met the clinical criteria for hereditary breast and ovarian cancer syndrome (HBOC) and were negative for BRCA1 and BRCA2 mutations. Moreover, 40 index patients fulfilled HBOC and the Li-Fraumeni-like (LFL) syndromes criteria. The samples were tested using next generation sequencing for TP53. Three patients harbored TP53 missense pathogenic variants (p.Arg248Gln, p.Arg337His, and p.Arg337Cys), confirmed by Sanger sequencing. One (1.2%) patient showed a large TP53 deletion (exons 2-11), which was also confirmed. The p.R337H variant was detected in only one patient. In conclusion, four (4.8%) early-onset breast cancer patients fulfilling the HBOC and LFL syndromes presented TP53 pathogenic variants, confirming the relevance of genetic tests in this group of patients. In contrast to other Brazilian regions, TP53 p.R337H variant appeared with low prevalence.


Assuntos
Neoplasias da Mama , Síndrome de Li-Fraumeni , Neoplasias Ovarianas , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Síndrome de Li-Fraumeni/epidemiologia , Síndrome de Li-Fraumeni/genética , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Síndrome , Proteína Supressora de Tumor p53/genética
19.
Front Oncol ; 12: 836937, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35371985

RESUMO

Breast cancer (BC) is the most prevalent malignancy in women with Li-Fraumeni syndrome (LFS). The literature on BC in LFS is limited due to its rarity worldwide. A TP53 founder pathogenic variant (c.1010G>A; p.R337H) is responsible for the higher prevalence of this syndrome among women of Brazilian ancestry. Purpose: The aim of the study was to describe the BC phenotype expressed by Brazilian female LFS carriers and compare the data between p.R337H and other TP53 germline pathogenic/likely pathogenic variants (non-p.R337H carriers). Methods: We searched for cases of TP53 germline pathogenic/likely pathogenic variant carriers affected by BC included between 2015 and 2020 in the BLiSS (Brazilian Li-Fraumeni Study) registry at the Sírio-Libanês Hospital. Results: Among 163 adult female carriers from the registry, 91 (56%) had received a BC diagnosis, including 72 p.R337H carriers. BC was the first cancer diagnosed in 90% of cases. Early onset BC (age ≤45 years) was diagnosed in 78.2% of cases (11.5% <31 years; 66.7% 31-45 years; 21.8% >45 years). The median age of BC diagnosis for p.R337H carriers was 39.5 years (range 20-69 years) compared to 34 years (range 21-63 years) for non-p.R337H carriers (p = 0.009). In total, 104 breast tumors were observed in 87 women. Bilateral BC was observed in 29.3% of cases. Histology was available for 96 tumors, comprising 69 invasive breast carcinomas, which were mostly invasive ductal carcinomas (95.6%), 25 ductal in situ carcinomas and 2 soft-tissue sarcomas. Overall, 90.5% of invasive breast carcinomas were hormone receptor (HR)-positive, 39.5% were human epidermal growth factor receptor 2 (HER2)-positive, and 32.8% showed HR and HER2 co-expression. In addition, 55.4% of patients opted for contralateral prophylactic mastectomy after a first BC diagnosis. There were no significant differences in the risk of developing contralateral BC or in the immunohistochemical profile between p.R337H and non-p.R337H groups. Conclusions: The expressed phenotype of p.R337H is similar to that of other TP53 pathogenic/likely pathogenic variants, except for an average older age at the onset of disease; however, this is still younger than the general population.

20.
J Phys Condens Matter ; 34(24)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35358960

RESUMO

We investigated by first principle calculations the adsorption of Liq(q= -1, 0 or +1) on a silicene single layer. Pristine and three different defective silicene configurations with and without Li doping were studied: single vacancy (SV), double vacancy (DV) and Stone-Wales (STW). Structural studies and the adsorption energies of various sites were obtained and compared in order to understand the stability of the Li on the surface. Moreover, electronic structure and charge density difference analysis were performed before and after adsorption at the most stables sites, which showed the presence of a magnetic moment in the undoped SV system, the displacement of the Fermi level produced by Li doping and a charge transfer from Li to the surface. Additionally, quantum capacity (QC) and charge density studies were performed on these systems. This analysis showed that the generation of defects and doping improves the QC of silicene in positive bias, because of the existence of 3p orbital in the zone of the defect. Consequently, the innovative calculations performed in this work of charged lithium doping on silicene can be used for future comparison with experimental studies of this Li-ion battery anode material candidate.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA