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1.
Cureus ; 16(7): e65520, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39188486

RESUMO

Atrial-esophageal fistulas are rare and potentially fatal complications that can occur from radiofrequency ablation for the treatment of atrial fibrillation. Due to the proximity of the right atrium to the esophagus, thermal injuries can involuntarily lead to connections between the heart and esophagus. In this case study, a 67-year-old male developed an atrial-esophageal fistula following atrial fibrillation ablation. After discharge, the patient first presented with melena with a range of complications including aspiration, fever, atrial fibrillation, and neurological symptoms. The fistula was repaired promptly after diagnosis requiring meticulous planning by the anesthesia and surgical teams. The major consideration from anesthesiology was providing adequate oxygenation during one-lung ventilation via continuous positive airway pressure on the non-dependent lung. This case also highlights the need for recognizing and managing potential complications associated with catheter ablation procedures. A thorough understanding of these rare but critical events is essential for optimizing patient outcomes and minimizing mortality rates, and physicians and healthcare professionals must remain vigilant regarding such complications.

2.
Micron ; 186: 103689, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39116575

RESUMO

Achieving high-quality cross sections is essential for accurate analysis of multilayer coatings. One method of performing such cross sections is focused ion beam, where sample protection from ion damage in the form of protective layers applied by FEBID and FIBID methods is used. Due to the lack of comparative summaries of different layers applied by these methods, especially in the context of cross-sectional analysis and elemental analysis of the cross-section, it was decided to address the effect of the protective layer on the reliability of EDS analysis. This study compares the effectiveness of platinum and carbon protective layers in creating cross sections for W/Hf/W samples. The effect of protective layers on elemental mapping and elemental analysis accuracy was evaluated. This study highlights the importance of protective layer selection in providing reliable EDS analysis of cross sections.

3.
Endocr Pract ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39127111

RESUMO

BACKGROUND: We examined the association of objective measures of cardiometabolic risk with progression to a high-risk for advanced fibrosis in patients with MASLD at initially low- and indeterminate-risk for advanced fibrosis. METHODS: We performed a retrospective cohort study of primary care patients with MASLD between 2012 and 2021. We evaluated patients with MASLD and low- or indeterminate-risk Fibrosis-4 Index (FIB-4) scores and followed them until the outcome of a high-risk FIB-4 (>2.67), or the end of the study period. Exposures of interest were body mass index (BMI), systolic blood pressure (SBP), hemoglobin A1c, cholesterol, estimated glomerular filtration rate (eGFR), and smoking status. Variables were categorized by the threshold for primary care therapy intensification. Unadjusted and adjusted Cox regression models were developed for the outcome of time to a high-risk FIB-4 value. RESULTS: The cohort included 1,347 patients with a mean follow-up of 3.6 years (SD 2.7). Of the cohort, 258 (19%) had a subsequent FIB-4 > 2.67. In the fully adjusted Cox regression models, mean SBP > 150 mm Hg (1.57; 95%CI 1.02-2.41) and eGFR < 59 ml/min (HR 2.78; 95%CI 2.17-3.58) were associated with an increased hazard of a high-risk FIB-4, while receiving a statin prescription (HR 0.51; 95%CI 0.39-0.66) was associated with a lower risk. CONCLUSIONS: Nearly 1 in 5 primary care patients with MASLD transitioned to a high-risk FIB-4 score during 3.6 years of follow-up, and uncontrolled blood pressure and reduced kidney function were associated with an increased hazard of a FIB-4 at high-risk for advanced fibrosis.

4.
Hepatol Res ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39134448

RESUMO

AIM: Liver fibrosis, heralding the potential progression to cirrhosis and hepatocellular carcinoma (HCC), compromises patient survival and augments post-hepatectomy recurrence. This study examined the detrimental effects of liver fibrosis on the antitumor functions of liver natural killer (NK) cells and the interleukin-33 (IL-33) signaling pathway. METHODS: Our investigation, anchored in both human physiologies using living and deceased donor livers and the carbon tetrachloride (CCl4)-induced mouse fibrosis model, aimed to show a troubling interface between liver fibrosis and weakened hepatic immunity. RESULTS: The Fibrosis-4 (FIB-4) index emerged as a salient, non-invasive prognostic marker, and its elevation correlated with reduced survival and heightened recurrence after HCC surgery even after propensity matching (n = 385). We established a strong correlation between liver fibrosis and liver NK cell dysfunction by developing a method for extracting liver NK cells from the liver graft perfusate. Furthermore, liver fibrosis ostensibly disrupted chemokines and promoted IL-33 expression, impeding liver NK cell antitumor activities, as evidenced in mouse models. Intriguingly, our results implicated IL-33 in diminishing the antitumor responses of NK cells. This interrelation, consistent across both mouse and human studies, coincides with clinical data suggesting that liver fibrosis predisposes patients to an increased risk of HCC recurrence. CONCLUSION: Our study revealed a critical relationship between liver fibrosis and compromised tumor immunity, emphasizing the potential interference of IL-33 with NK cell function. These insights advocate for advanced immunostimulatory therapies targeting cytokines, such as IL-33, aiming to bolster the hepatic immune response against HCC in the context of liver fibrosis.

5.
ACS Appl Mater Interfaces ; 16(32): 42034-42048, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39102531

RESUMO

Solid-state batteries promise higher energy density and improved safety compared with lithium-ion batteries. However, electro-chemomechanical instabilities at the solid electrolyte interface with the cathode and the anode hinder their large scale implementation. Here, we focus on resolving electro-chemo-mechanical instability mechanisms and their onset conditions between a state-of-the-art cathode, LiNi0.6Mn0.2Co0.2O2 (NMC622), and the garnet Li7La3Zr2O12 (LLZO) solid electrolyte. We used thin-film NMC622 on LLZO pellets to place the interfacial region within the detection depth of the X-ray characterization techniques. The experimental probes of the near-interface region included in operando X-ray absorption spectroscopy and ex situ focused ion beam scanning electron microscopy. Electrochemical degradation was not observable during cycling at room temperature with 4.3 V versus Li/Li+ charge voltage cutoff, or with stepwise potentiostatic hold up to 4.1 V versus Li/Li+. In contrast, secondary phases including reduced transition metal species (Ni2+, Co2+) were found after cycling up to 4.3 V versus Li/Li+ at 80 °C and during potentiostatic hold at 4.3 V versus Li/Li+ (Ni2+). Intergranular cracks between NMC622 grains and delamination at the NMC622|LLZO interface occurred readily after the first charge. These interface reaction products and mechanical failure lowered the capacity and cell efficiency due to partial loss of the NMC622 phase, partial loss of contact at the interface, and a higher polarization resistance. Electrochemical instability between delithiated NMC622 and LLZO could be mitigated by using a low charge voltage cutoff or cycling at lower temperature. Ways to engineer the mechanical properties to avoid crack deflection and delamination at the interface are also discussed for enhancing mechanical stability.

6.
Int J Mol Sci ; 25(15)2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39125914

RESUMO

Multiple drug resistance (MDR) has gained pronounced attention among Enterobacterales. The transfer of multiple antimicrobial resistance genes, frequently carried on conjugative incompatibility F (IncF) plasmids and facilitating interspecies resistance transmission, has been linked to Salmonella spp. and E. coli in broilers. In Egypt, the growing resistance is exacerbated by the limited clinical efficacy of many antimicrobials. In this study, IncF groups were screened and characterized in drug-resistant Salmonella spp. and E. coli isolated from broilers. The antimicrobial resistance profile, PCR-based replicon typing of bacterial isolates pre- and post-plasmid curing, and IncF replicon allele sequence typing were investigated. Five isolates of E. coli (5/31; 16.13%) and Salmonella spp. (5/36; 13.89%) were pan-susceptible to the examined antimicrobial agents, and 85.07% of tested isolates were MDR and extensively drug-resistant (XDR). Twelve MDR and XDR E. coli and Salmonella spp. isolates were examined for the existence of IncF replicons (FII, FIA, and FIB). They shared resistance to ampicillin, ampicillin/sulbactam, amoxicillin/clavulanate, doxycycline, cefotaxime, and colistin. All isolates carried from one to two IncF replicons. The FII-FIA-FIB+ and FII-FIA+FIB- were the predominant replicon patterns. FIB was the most frequently detected replicon after plasmid curing. Three XDR E. coli isolates that were resistant to 12-14 antimicrobials carried a newly FIB replicon allele with four nucleotide substitutions: C99→A, G112→T, C113→T, and G114→A. These findings suggest that broilers are a significant reservoir of IncF replicons with highly divergent IncF-FIB plasmid incompatibility groups circulating among XDR Enterobacterales. Supporting these data with additional comprehensive epidemiological studies involving replicons other than the IncF can provide insights for implementing efficient policies to prevent the spreading of new replicons to humans.


Assuntos
Alelos , Galinhas , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli , Escherichia coli , Plasmídeos , Doenças das Aves Domésticas , Replicon , Animais , Galinhas/microbiologia , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Replicon/genética , Farmacorresistência Bacteriana Múltipla/genética , Plasmídeos/genética , Doenças das Aves Domésticas/microbiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Salmonella/genética , Salmonella/efeitos dos fármacos
7.
Cereb Cortex ; 34(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39106175

RESUMO

Functional and structural studies investigating macroscopic connectivity in the human cerebral cortex suggest that high-order associative regions exhibit greater connectivity compared to primary ones. However, the synaptic organization of these brain regions remains unexplored. In the present work, we conducted volume electron microscopy to investigate the synaptic organization of the human brain obtained at autopsy. Specifically, we examined layer III of Brodmann areas 17, 3b, and 4, as representative areas of primary visual, somatosensorial, and motor cortex. Additionally, we conducted comparative analyses with our previous datasets of layer III from temporopolar and anterior cingulate associative cortical regions (Brodmann areas 24, 38, and 21). 9,690 synaptic junctions were 3D reconstructed, showing that certain synaptic characteristics are specific to particular regions. The number of synapses per volume, the proportion of the postsynaptic targets, and the synaptic size may distinguish one region from another, regardless of whether they are associative or primary cortex. By contrast, other synaptic characteristics were common to all analyzed regions, such as the proportion of excitatory and inhibitory synapses, their shapes, their spatial distribution, and a higher proportion of synapses located on dendritic spines. The present results provide further insights into the synaptic organization of the human cerebral cortex.


Assuntos
Córtex Cerebral , Sinapses , Microscopia Eletrônica de Volume , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Cerebral/ultraestrutura , Espinhas Dendríticas/ultraestrutura , Imageamento Tridimensional/métodos , Sinapses/ultraestrutura
8.
F1000Res ; 13: 280, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39099607

RESUMO

Background: The level of liver fibrosis is the basis for the treatment of chronic hepatitis B (CHB), and it is necessary to adapt non-invasive liver fibrosis modalities. We aimed to investigate the use of M2BPGi as a single or combined diagnostic modality for liver fibrosis in CHB patients through a stepwise diagnostic analysis. Methods: Cross-sectional data were taken from patients between October 2021 and August 2022. Demographic data, blood profile, liver function, and liver stiffness were measured in CHB patients over 18 years old, willing to take part in the research, and had complete data. APRI, FIB-4, and AAR were calculated using the well-known formulas. Serum M2BPGi-levels were converted into a cut-off index (COI). The patients were divided into low-risk (LR) and high-risk fibrosis (HR) groups. A cut-off for each predictor variable to differentiate between the LR and HR groups was determined. The obtained cut-off was assessed for its association with the grouping of liver elastography results. Models to diagnose the liver stiffness measurement (LSM) ≥8 kPa were created and compared through multivariate and ROC analyses. Results: The number of patients that met the inclusion and exclusion criteria was 143 (HR = 65, LR = 78). The cut-off for diagnosing LSM ≥8kPa was 0.311, 0.742, 0.635, and 1.434 for APRI, FIB-4, AAR, and M2BPGi, respectively. This cut-off was significantly associated with the results of the HR and LR groupings. A multivariate analysis found that FIB4, AAR, and M2BPGi added significantly to the model. Statistically, the most optimal use of M2BPGi was combined with FIB-4, with an AUC of 0.835. Conclusions: The optimal cut-off of M2BPGi for diagnosing high-risk liver fibrosis in this study was 1.434. M2BPGi should be used with FIB-4 as a diagnostic tool for diagnosing liver fibrosis, especially in the absence of a liver biopsy or elastography.


Assuntos
Antígenos de Neoplasias , Hepatite B Crônica , Cirrose Hepática , Humanos , Hepatite B Crônica/complicações , Hepatite B Crônica/sangue , Hepatite B Crônica/diagnóstico , Cirrose Hepática/diagnóstico , Cirrose Hepática/sangue , Cirrose Hepática/patologia , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Estudos Transversais , Antígenos de Neoplasias/sangue , Técnicas de Imagem por Elasticidade , Glicosilação , Biomarcadores/sangue , Glicoproteínas de Membrana/sangue , Curva ROC
9.
Ann Med Surg (Lond) ; 86(7): 3841-3846, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38989210

RESUMO

Background: Hepatitis B (HBV) and hepatitis C viruses (HCV) are significant causes of liver disease worldwide. Liver fibrosis (LF) is a complication of chronic liver damage caused by HBV and HCV due to our limited knowledge comparing the diagnostic performance of platelet to aspartate aminotransferase ratio index (APRI) and fibrosis-4 (FIB-4) index with fibroscan. Methods: This study evaluated liver damage in HBV and HCV using APRI, FIB-4, and fibroscan indices. This retrospective cohort descriptive-analytical study was conducted on patients with HBV and HCV. This study uses laboratory results and imaging to investigate liver damage in chronic HBV and HCV patients. APRI and FIB-4 were computed based on laboratory results. Results: A total of 185 patients (82 hepatitis B and 103 hepatitis C) were included in the study. Thirteen patients had liver cirrhosis. There was no statistically significant difference between the fibroscan results in the two groups (P=0.99). The HBV group's mean APRI and FIB-4 were lower than HCV, but no significant difference was observed (P>0.05). Our results in HBV and HCV patients showed that APRI and FIB-4 accomplished well anticipating cirrhosis with an area under the receiver operating characteristic curve (AUC) of 0.771-0.845 and 0.871-0.910, respectively. Conclusion: Fibroscan is a powerful tool superior to APRI and FIB-4 in predicting LF and cirrhosis. Nevertheless, APRI and FIB-4 are inexpensive and non-invasive indicators with acceptable efficacy in predicting advanced fibrosis or cirrhosis. However, these two measures are not reliable in low-grade fibrosis.

10.
Diagnostics (Basel) ; 14(13)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-39001207

RESUMO

Background and aims: The enhanced liver fibrosis (ELF) score is a blood test that combines three markers linked to liver fibrosis. The utility of the ELF score has been demonstrated primarily in Western countries, but whether it is useful in areas with a high number of elderly people suffering from chronic liver disease has yet to be determined. Methods: This is a prospective study that included 373 consecutive patients who underwent a liver biopsy and had their ELF score measured on the same day. The diagnostic accuracy of the ELF score for liver fibrosis and the effect of age on the ELF score were investigated. Results: The median (interquartile) ELF scores in F0, F1, F2, F3, and F4 are 8.7 (8.2-9.2), 9.3 (8.8-10.0), 10.1 (9.4-10.7), 10.7 (9.9-11.2), and 12.0 (11.2-12.7), respectively. ELF scores increased with increasing liver fibrosis stage (p < 0.001). The diagnostic accuracy of the ELF score and FIB-4 for significant fibrosis (F2-4) and advanced fibrosis (F3-4) was comparable, but the ELF score had a higher diagnostic accuracy for cirrhosis (F4) than FIB-4. When patients were stratified by age of 60 years, the median ELF score did not differ by age in F2, F3, and F4. However, the median FIB-4 increased in patients with ≥60 years compared to those with <60 years in all fibrosis stages. Conclusions: ELF score has high diagnostic accuracy for liver fibrosis, regardless of age, and it could be used as a primary screening method.

11.
Liver Int ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016540

RESUMO

BACKGROUND AND AIMS: Adaptive immunity is gaining a significant role in progression of metabolic dysfunction-associated steatotic liver disease (MASLD). B-cell activity can be assessed by serum-free light chains (sFLCs) k and λ levels. The objective of the present investigation is to examine the utility of sFLCs as non-invasive biomarkers for the stratification of MASLD. METHODS: We enrolled a consecutive cohort from an outpatient liver unit. Diagnosis of metabolic dysfunction-associated steatohepatitis (MASH) was made with liver biopsy according to current guidelines. Compensated advanced chronic liver disease (cACLD) and clinically significant portal hypertension (CSPH) were defined according to Baveno VII criteria. sFLCs were measured by turbidimetry using an immunoassay. RESULTS: We evaluated 254 patients, 162/254 (63.8%) were male. Median age was 54 years old, and the median body mass index was 28.4 kg/m2. A total of 157/254 (61.8%) subjects underwent liver biopsy: 88 had histological diagnosis of MASH, 89 were considered as simple metabolic dysfunction-associated steatotic liver (MASL) and 77/254 (30.3%) patients with compensated metabolic dysfunction-associated cirrhosis. By using Baveno VII criteria, 101/254 (39.7%) patients had cACLD; among them, 45/101 (44.5%) had CSPH. Patients with cACLD showed higher sFLC levels compared with patients without cACLD (p < .01), and patients with CSPH showed higher sFLC levels than patients without CSPH (p < .01). At multivariable analysis, sFLCs were associated with cACLD (p < .05) independently from γ-globulins and other known dysmetabolic risk factors. κFLC was associated with CSPH (p < .05) independently from γ-globulins and other known dysmetabolic risk factors. CONCLUSION: sFLCs could be a simple biomarker for stratification of cACLD in MASLD patients.

12.
Intern Med J ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078091

RESUMO

BACKGROUND: Long specialist outpatient waiting lists are a source of clinical risk. Triage assignment is based on subjective assessment of referrals and fails to account for dynamic changes in disease status while patients await clinical review. AIMS: To pilot an innovative triage method using a trifold approach to conduct noninvasive assessment of fibrosis and to determine the feasibility of reflex hepatitis C virus (HCV) polymerase chain reaction (PCR) testing. METHODS: A total of 1006 patients awaiting an initial liver clinic appointment at a tertiary Australian hospital were sent a short message service (SMS) requesting a blood test be completed. The first 60 patients received an SMS only, and the subsequent 946 patients also received a phone call from a Liver Care Guide (LCG), a nonclinician employed to increase patient engagement. Liver fibrosis assessment through noninvasive testing was performed using an aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB4) score. Patients with an APRI ≥1, FIB4 ≥3.25 or positive HCV PCR were retriaged to Category 1. RESULTS: Four hundred ninety (49%) patients completed testing and 40 (4%) were triaged to Category 1. Subanalyses demonstrated increased response rates with LCG input (P = 0.012). Retriaged patients had been on the waitlist for a median of 216 days, exceeding initial category recommendations. CONCLUSION: This study successfully implemented a semiautomated strategy that prioritises patients with probable advanced liver disease or active HCV, demonstrating enhanced patient engagement with LCG support. It highlights the burden of patients referred for specialist care and the need for innovative strategies for monitoring and objective risk stratification.

13.
JGH Open ; 8(7): e70010, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39055237

RESUMO

Background and Aim: We conducted a study using the Fibrosis-3 (FIB-3) index, which is the established age-independent index of fibrosis in nonviral liver disease and addresses the limitations of the FIB-4 index in older age group, to assess the liver fibrosis risk among diverse demographic groups in the general population. Methods: We analyzed 31 327 individuals who underwent health examinations between 2013 and 2020 and investigated the distribution of the FIB-3 index by age group. In addition, we examined the age distribution of the FIB-3 index stratified by background factors, such as sex, body mass index (BMI), alcohol consumption habits, and the presence or absence of fatty liver. Results: In terms of age-specific distribution, the FIB-3 index remained below 1.5 in >90% of cases until the age of 50 years but exceeded 1.5 beyond the age of 50 years, in approximately 30% among those aged 70 years. Notably, the FIB-3 index above 31 years old was significantly higher in men than in women. Among the different BMI categories, individuals with BMI < 18.5 exhibited the highest prevalence of fibrosis. Habitual drinkers had a higher proportion with FIB-3. index ≥1.5, and some had FIB-3 index ≥2.5, raising the suspicion of advanced hepatic fibrosis. No distinct association was identified between the FIB-3 index and the presence of fatty liver. Conclusions: The FIB-3 index was useful for identifying cases of advancing hepatic fibrosis in a health checkup population. Liver fibrosis progresses with age in the general population, especially among men, those with low BMI, and habitual drinkers.

14.
Materials (Basel) ; 17(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38998308

RESUMO

Molten salts have been used as heat transfer fluids since the middle of the 20th century. More recently, molten chloride salts have been studied for use in concentrated solar power plants or molten salt reactors. However, none of the materials studied to date has been able to withstand this highly corrosive environment without controlling the salt's redox potential. The alumina-forming alloy was a promising option, as it has not yet been widely studied. To investigate this possibility, two iron-based alumina-forming alloys were corroded in NaCl-MgCl2 eutectic at 600 °C for 500 h after being pre-oxidised to grow a protective layer of α-alumina on each alloy. A salt purification protocol based on salt electrolysis was implemented to ensure comparable and reproducible results. During immersion, alumina was transformed into MgAl2O4, as shown by FIB-SEM observation. Inter and intragranular corrosion were observed, with the formation of MgAl2O4 in the corroded zones. The nature of the oxides was explained by the predominance diagram. Intragranular corrosion was 2 µm deep, and intergranular corrosion 10 µm deep. Alumina formed at the bottom of the intergranular corrosion zones. The depth of intergranular corrosion is consistent with O diffusion control at the grain boundary.

15.
Clin Biochem ; 131-132: 110789, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38977211

RESUMO

INTRODUCTION: Quick and simple parameters are needed to predict mortality in patients with idiopathic pulmonary fibrosis (IPF). In this way, risky patients will have the opportunity to receive early and effective treatment. In this study, we examined whether the Fibrosis-4 index (FIB-4) and systemic immune inflammation index (SII) are associated with mortality in IPF patients. MATERIALS AND METHODS: The study was designed retrospectively. 100 patients diagnosed with IPF were included in the study. Variables between living patients and deceased patients were examined. RESULTS: Out of a total of 100 patients, 67 were divided into the surviving group and 33 into the non-surviving group. In multivariate analysis, high FIB-4 and SII values were significantly associated with an increased risk of death. CONCLUSION: FIB-4 and SII are parameters that can predict mortality in IPF patients. In this way, IPF patients with high mortality risk will be identified earlier and more effective methods will be used in follow-up and treatment.

16.
J Struct Biol X ; 9: 100102, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38962493

RESUMO

Microcrystal electron diffraction (MicroED) has emerged as a powerful technique for unraveling molecular structures from microcrystals too small for X-ray diffraction. However, a significant hurdle arises with plate-like crystals that consistently orient themselves flat on the electron microscopy grid. If the normal of the plate correlates with the axes of the crystal lattice, the crystal orientations accessible for measurement are restricted because the crystal cannot be arbitrarily rotated. This limits the information that can be acquired, resulting in a missing cone of information. We recently introduced a novel crystallization strategy called suspended drop crystallization and proposed that crystals in a suspended drop could effectively address the challenge of preferred crystal orientation. Here we demonstrate the success of the suspended drop approach in eliminating the missing cone in two samples that crystallize as thin plates: bovine liver catalase and the SARS­CoV­2 main protease (Mpro). This innovative solution proves indispensable for crystals exhibiting systematic preferred orientations, unlocking new possibilities for structure determination by MicroED.

17.
Acta Biomater ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38992411

RESUMO

Collagen-based hydrogels are commonly used in mechanobiology to mimic the extracellular matrix. A quantitative analysis of the influence of collagen concentration and properties on the structure and mechanics of the hydrogels is essential for tailored design adjustments for specific in vitro conditions. We combined focused ion beam scanning electron microscopy and rheology to provide a detailed quantitative atlas of the mechanical and nanoscale three-dimensional structural alterations that occur when manipulating different hydrogel's physicochemistry. Moreover, we study the effects of such alterations on the phenotype of breast cancer cells and their mechanical interactions with the extracellular matrix. Regardless of the microenvironment's pore size, porosity or mechanical properties, cancer cells are able to reach a stable mesenchymal-like morphology. Additionally, employing 3D traction force microscopy, a positive correlation between cellular tractions and ECM mechanics is observed up to a critical threshold, beyond which tractions plateau. This suggests that cancer cells in a stable mesenchymal state calibrate their mechanical interactions with the ECM to keep their migration and invasiveness capacities unaltered. STATEMENT OF SIGNIFICANCE: The paper presents a thorough study on the mechanical microenvironment in breast cancer cells during their interaction with collagen based hydrogels of different compositions. The hydrogels' microstructure were obtained using state-of-the-art 3D microscopy, namely focused ion beam-scanning electron microscope (FIB-SEM). FIB-SEM was originally applied in this work to reconstruct complex fibered collagen microstructures within the nanometer range, to obtain key microarchitectural parameters. The mechanical microenvironment of cells was recovered using Traction Force Microscopy (TFM). The obtained results suggest that cells calibrate tractions such that they depend on mechanical, microstructural and physicochemical characteristics of the hydrogels, hence revealing a steric hindrance. We hypothesize that cancer cells studied in this paper tune their mechanical state to keep their migration and invasiveness capacities unaltered.

18.
BMC Med ; 22(1): 278, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956533

RESUMO

BACKGROUND: APRI and FIB-4 scores are used to exclude clinically significant fibrosis (defined as stage ≥ F2) in patients with chronic viral hepatitis. However, the cut-offs for these scores (generated by Youden indices) vary between different patient cohorts. This study aimed to evaluate whether serum dithiothreitol-oxidizing capacity (DOC), i.e., a surrogate test of quiescin sulfhydryl oxidase-1, which is a matrix remodeling enzyme, could be used to non-invasively identify significant fibrosis in patients with various chronic liver diseases (CLDs). METHODS: Diagnostic performance of DOC was compared with APRI and FIB-4 for identifying significant fibrosis. ROC curve analyses were undertaken in: a) two chronic hepatitis B (CHB) cohorts, independently established from hospitals in Wenzhou (n = 208) and Hefei (n = 120); b) a MASLD cohort from Wenzhou hospital (n = 122); and c) a cohort with multiple CLD etiologies (except CHB and MASLD; n = 102), which was identified from patients in both hospitals. Cut-offs were calculated using the Youden index. All CLD patients (n = 552) were then stratified by age for ROC curve analyses and cut-off calculations. RESULTS: Stratified by CLD etiology or age, ROC curve analyses consistently showed that the DOC test was superior to APRI and FIB-4 for discriminating between clinically significant fibrosis and no fibrosis, when APRI and FIB-4 showed poor/modest diagnostic performance (P < 0.05, P < 0.01 and P < 0.001 in 3, 1 and 3 cohort comparisons, respectively). Conversely, the DOC test was equivalent to APRI and FIB-4 when all tests showed moderate/adequate diagnostic performances (P > 0.05 in 11 cohort comparisons). DOC had a significant advantage over APRI or FIB-4 scores for establishing a uniform cut-off independently of age and CLD etiology (coefficients of variation of DOC, APRI and FIB-4 cut-offs were 1.7%, 22.9% and 47.6% in cohorts stratified by CLD etiology, 2.0%, 26.7% and 29.5% in cohorts stratified by age, respectively). The uniform cut-off was 2.13, yielded from all patients examined. Surprisingly, the uniform cut-off was the same as the DOC upper limit of normal with a specificity of 99%, estimated from 275 healthy control individuals. Hence, the uniform cut-off should possess a high negative predictive value for excluding significant fibrosis in primary care settings. A high DOC cut-off with 97.5% specificity could be used for detecting significant fibrosis (≥ F2) with an acceptable positive predictive value (87.1%). CONCLUSIONS: This proof-of-concept study suggests that the DOC test may efficiently rule out and rule in significant liver fibrosis, thereby reducing the numbers of unnecessary liver biopsies. Moreover, the DOC test may be helpful for clinicians to exclude significant liver fibrosis in the general population.


Assuntos
Biomarcadores , Ditiotreitol , Cirrose Hepática , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/sangue , Masculino , Pessoa de Meia-Idade , Biomarcadores/sangue , Feminino , Adulto , Idoso , Oxirredução , Curva ROC , Estudos de Coortes , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/sangue , Estudo de Prova de Conceito
19.
Nano Lett ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950105

RESUMO

Molybdenum disulfide (MoS2) is one of the most intriguing two-dimensional materials, and moreover, its single atomic defects can significantly alter the properties. These defects can be both imaged and engineered using spherical and chromatic aberration-corrected high-resolution transmission electron microscopy (CC/CS-corrected HRTEM). In a few-layer stack, several atoms are vertically aligned in one atomic column. Therefore, it is challenging to determine the positions of missing atoms and the damage cross-section, particularly in the not directly accessible middle layers. In this study, we introduce a technique for extracting subtle intensity differences in CC/CS-corrected HRTEM images. By exploiting the crystal structure of the material, our method discerns chalcogen vacancies even in the middle layer of trilayer MoS2. We found that in trilayer MoS2 the middle layer's damage cross-section is about ten times lower than that in the monolayer. Our findings could be essential for the application of few-layer MoS2 in nanodevices.

20.
Nanotechnology ; 35(41)2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39008956

RESUMO

Due to its capacity to achieve nanometre-scale machining and lithography, a focused ion beam (FIB) is an extended tool for semiconductor device fabrication and development, in particular, for diamond-based devices. However, some technological steps are still not fully optimized for its use. Indeed, ion implantation seems to affect the crystalline structure and electrical properties of diamond. For this study, a boron-doped ([B] ∼ 1017atoms·cm-3) diamond layer grown by chemical vapour deposition was irradiated using Ga+by FIB, with 1 nA current and 5, 20, and 30 keV of acceleration voltage. The Ga+implanted diamond layer has been analysed through cathodoluminescence (CL) and scanning transmission electron microscopy (STEM)-related techniques. The beam penetration depth has been simulated by Monte Carlo calculations of both Ga+(FIB) and e-(CL) beams at different energies. The comparative CL analysis of the layer as-grown and after implantation revealed peaks related to defects, such as A band, H3 centre, and defects present in the green band region. The STEM studies for the 30 keV implanted sample showed that the diamond lattice is affected by the damage, evidencing amorphisation in the layer with a sp2/sp3ratio of 1.37, estimated by electron energy loss spectroscopy. Therefore, this study highlights the effects of the Ga+implantation on the optical and structural characteristics of diamond, using different methods.

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