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1.
Neurosurg Focus ; 56(5): E11, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38691862

RESUMO

OBJECTIVE: In the treatment of skull base chordoma (SBC) surgery is considered the mainstay approach, and gross-total resection has an established relationship with progression-free survival (PFS) and overall survival (OS). However, the tumor's location often interferes with attempts at complete resection. In this case, surgery for maximal resection followed by high-dose radiotherapy has been demonstrated to be the standard treatment. In this context, various modalities are available, yet no consensus exists on the most effective. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of different radiotherapy modalities for SBC. METHODS: Following PRISMA guidelines, the authors systematically searched for the treatment of SBC with radiation modalities in the PubMed, Cochrane, Web of Science, and EMBASE databases. Outcomes assessed for each modality were as follows: OS, PFS, local control (LC), and complications. The random-effects model was adopted. A single-proportion analysis with 95% CI was used to measure the effects in single-arm analysis. For the comparative analysis, the OR with 95% CI was used to compare outcome treatment effects. Heterogeneity was assessed using I2 statistics, and statistical significance was defined as p < 0.05. RESULTS: A total of 32 studies comprising 3663 patients, with 2322 patients who were treated with radiotherapeutic modalities, were included. Regarding 5-year OS findings in each modality study, the findings were as follows: in photon fractionated radiotherapy, an estimated rate of 77% (69%-84%, 568 patients); in conventional fractionated radiotherapy, 76% (65%-87%, 517 cases); in proton-based + carbon ion-based radiotherapy, 85% (82%-88%, 622 cases); and in a comparative analysis of proton-based and carbon ion-based therapy, there was an OR of 1.2 (95% CI 0.59-2.43, 306 cases). Regarding the 5-year PFS estimate, the rates were as follows: 35% (26%-45%, 95 cases) for photon fractionated therapy; 35% (25%-45%, 85 cases) for stereotactic radiotherapy; 77% (50%-100%, 180 cases) for proton-based and carbon ion-based radiotherapy; and 74% (45%-100%, 102 cases) for proton-based radiotherapy. Regarding LC in periods of 3 and 5 years after proton- and carbon ion-based therapy, the overall estimated rates were 84% (78%-90%, 326 cases) and 75% (65%-85%, 448 cases), respectively. For proton-based radiotherapy and carbon ion-based therapy, the 5-year LC rates were 76% (67%-86%, 259 cases) and 75% (59%-91%, 189 cases), respectively. CONCLUSIONS: The analysis highlights the finding that particle-based modalities like proton beam radiotherapy and carbon ion radiotherapy are the most effective radiation therapies available for the treatment of SBC. Furthermore, it reinforces the idea that surgery followed by radiotherapy constitutes the standard treatment.


Assuntos
Cordoma , Neoplasias da Base do Crânio , Humanos , Neoplasias da Base do Crânio/radioterapia , Neoplasias da Base do Crânio/cirurgia , Cordoma/radioterapia , Cordoma/cirurgia , Resultado do Tratamento , Radiocirurgia/métodos
2.
J Gastrointest Cancer ; 55(2): 652-661, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38564116

RESUMO

BACKGROUND: Laparoscopy-assisted gastrectomy (LAG) is a well-established surgical technique in treating patients with early gastric cancer. However, the efficacy and safety of LAG versus open gastrectomy (OG) in patients with advanced gastric cancer (AGC) remains unclear. METHODS: We systematically searched PubMed, Embase, and Cochrane Library in June 2023 for RCTs comparing LAG versus OG in patients with AGC. We pooled risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI) for binary and continuous endpoints, respectively. We performed all statistical analyses using R software version 4.3.1 and a random-effects model. RESULTS: Nine RCTs comprising 3827 patients were included. There were no differences in terms of intraoperative complications (RR 1.14; 95% CI 0.72 to 1.82), number of retrieved lymph nodes (MD -0.54 lymph nodes; 95% CI -1.18 to 0.09), or mortality (RR 0.91; 95% CI 0.30 to 2.83). LAG was associated with a longer operative time (MD 49.28 minutes; 95% CI 30.88 to 67.69), lower intraoperative blood loss (MD -51.24 milliliters; 95% CI -81.41 to -21.06), shorter length of stay (MD -0.83 days; 95% CI -1.60 to -0.06), and higher incidence of pancreatic fistula (RR 2.44; 95% CI 1.08 to 5.50). Postoperatively, LAG was also superior to OG in reducing bleeding rates (RR 0.44; 95% CI 0.22 to 0.86) and time to first flatus (MD -0.27 days; 95% CI -0.47 to -0.07), with comparable results in anastomotic leakage, wound healing issues, major complications, time to ambulation, or time to first liquid intake. In the long-term analyses at 3 and 5 years, there were no significant differences between LAG and OG in terms of overall survival (RR 0.99; 95% CI 0.96 to 1.03) or relapse-free survival (RR 0.99; 95% CI 0.94 to 1.04). CONCLUSION: This meta-analysis of RCTs suggests that LAG may be an effective and safe alternative to OG for treating AGC; albeit, it may be associated with an increased risk for pancreatic fistula.


Assuntos
Gastrectomia , Laparoscopia , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/mortalidade , Gastrectomia/métodos , Gastrectomia/efeitos adversos , Laparoscopia/métodos , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Tempo de Internação/estatística & dados numéricos , Resultado do Tratamento , Perda Sanguínea Cirúrgica/estatística & dados numéricos
3.
Nucleic Acids Res ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619040

RESUMO

When preparing biomolecular structures for molecular dynamics simulations, pKa calculations are required to provide at least a representative protonation state at a given pH value. Neglecting this step and adopting the reference protonation states of the amino acid residues in water, often leads to wrong electrostatics and nonphysical simulations. Fortunately, several methods have been developed to prepare structures considering the protonation preference of residues in their specific environments (pKa values), and some are even available for online usage. In this work, we present the PypKa server, which allows users to run physics-based, as well as ML-accelerated methods suitable for larger systems, to obtain pKa values, isoelectric points, titration curves, and structures with representative pH-dependent protonation states compatible with commonly used force fields (AMBER, CHARMM, GROMOS). The user may upload a custom structure or submit an identifier code from PBD or UniProtKB. The results for over 200k structures taken from the Protein Data Bank and the AlphaFold DB have been precomputed, and their data can be retrieved without extra calculations. All this information can also be obtained from an application programming interface (API) facilitating its usage and integration into existing pipelines as well as other web services. The web server is available at pypka.org.

4.
Neurosurg Rev ; 47(1): 47, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38221545

RESUMO

BACKGROUND AND OBJECTIVES: High-grade gliomas (HGGs) are aggressive tumors of the central nervous system that cause significant morbidity and mortality. Despite advances in surgery and radiation therapy (RT), HGG still has a high incidence of recurrence and treatment failure. Intraoperative radiotherapy (IORT) has emerged as a promising therapeutic approach to achieve local tumor control while sparing normal brain tissue from radiation-induced damage. METHODS: A systematic review and meta-analysis were conducted following PRISMA guidelines to evaluate the use of IORT for HGG. Eligible studies were included based on specific criteria, and data were independently extracted. Outcomes of interest included complications, IORT failure, survival rates at 12 and 24 months, and mortality. RESULTS: Sixteen studies comprising 436 patients were included. The overall complication rate after IORT was 17%, with significant heterogeneity observed. The IORT failure rate was 77%, while the survival rates at 12 and 24 months were 74% and 24%, respectively. The mortality rate was 62%. CONCLUSION: This meta-analysis suggests that IORT may be a promising adjuvant treatment for selected patients with HGG. Despite the high rate of complications and treatment failures, the survival outcomes were comparable or even superior to conventional methods. However, the limitations of the study, such as the lack of a control group and small sample sizes, warrant further investigation through prospective randomized controlled trials to better understand the specific patient populations that may benefit most from IORT. However, the limitations of the study, such as the lack of a control group and small sample sizes, warrant further investigation. Notably, the ongoing RP3 trial (NCT02685605) is currently underway, with the aim of providing a more comprehensive understanding of IORT. Moreover, future research should focus on managing complications associated with IORT to improve its safety and efficacy in treating HGG.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/tratamento farmacológico , Estudos Prospectivos , Glioma/radioterapia , Glioma/cirurgia , Recidiva Local de Neoplasia , Radioterapia/efeitos adversos
5.
Ann Vasc Surg ; 102: 236-243, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37944897

RESUMO

INTRODUCTION/OBJECTIVE: Carotid stenosis (CS) is an important cause of ischemic stroke. Secondary prevention lies in performing a carotid endarterectomy (CEA) procedure, the recommended treatment in most cases. When 2 or more vascular regions are simultaneously affected by atherosclerosis, mainly the carotid arteries, coronary arteries, or limb arteries, a multivessel disease polyvascular disease (PVD) is present. This study aims to assess the potential role of PVD as a long-term predictor of major adverse cardiovascular events (MACE) and all-cause mortality in patients submitted to CEA. METHODS: From January 2012 to December 2021, patients submitted to CEA for carotid stenosis in a tertiary care and referral center were eligible from a prospective database. A posthoc survival analysis was performed using the Kaplan-Meier survival curve method. The primary outcome was the incidence of long-term MACE and all-cause mortality. Secondary outcomes included acute myocardial infarction (AMI), major adverse limb events (MALE), stroke, and acute heart failure (AHF). RESULTS: A total of 207 patients were enrolled, with a median follow-up of 63 months. The mean age was 70.4 ± 8.9, and 163 (78.7%) were male. There were 65 (31.4%) patients that had 2 arterial vascular territories affected, and 29 (14.0%) patients had PVD in 3 arterial beds. On multivariable analysis, both MACE and all-cause mortality had as independent risk factors age (aHR 1.039, P = 0.003; aHR 1.041, P = 0.019), chronic kidney disease (aHR 2.524, P = 0.003; aHR 3.377, P < 0.001) and PVD2 (aHR 3.381, P < 0.001; aHR 2.665, P = 0.013). PVD1 was only associated with MACE as a statistically significant risk factor (aHR 2.531, 1.439-4.450, P < 0.001). CONCLUSIONS: PVD in patients with cerebrovascular disease (CVD) was revealed to carry a 2-fold increased risk for all-cause mortality and MACE during long-term follow-up. PVD may be a simple yet valuable tool in predicting all-cause mortality, MACE, AMI, and MALE after CEA.


Assuntos
Estenose das Carótidas , Endarterectomia das Carótidas , Infarto do Miocárdio , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , Endarterectomia das Carótidas/efeitos adversos , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Resultado do Tratamento , Fatores de Risco , Infarto do Miocárdio/etiologia , Estudos Retrospectivos , Medição de Risco
6.
Mol Cell Proteomics ; 23(2): 100705, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38135118

RESUMO

The microbe-associated molecular pattern flg22 is recognized in a flagellin-sensitive 2-dependent manner in root tip cells. Here, we show a rapid and massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome in WT and a mutant deficient in heterotrimeric G-protein-coupled signaling. flg22-induced changes fall on proteins comprising a subset of this proteome, the heterotrimeric G protein interactome, and on highly-populated hubs of the immunity network. Approximately 95% of the phosphorylation changes in the heterotrimeric G-protein interactome depend, at least partially, on a functional G protein complex. One member of this interactome is ATBα, a substrate-recognition subunit of a protein phosphatase 2A complex and an interactor to Arabidopsis thaliana Regulator of G Signaling 1 protein (AtRGS1), a flg22-phosphorylated, 7-transmembrane spanning modulator of the nucleotide-binding state of the core G-protein complex. A null mutation of ATBα strongly increases basal endocytosis of AtRGS1. AtRGS1 steady-state protein level is lower in the atbα mutant in a proteasome-dependent manner. We propose that phosphorylation-dependent endocytosis of AtRGS1 is part of the mechanism to degrade AtRGS1, thus sustaining activation of the heterotrimeric G protein complex required for the regulation of system dynamics in innate immunity. The PP2A(ATBα) complex is a critical regulator of this signaling pathway.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas Heterotriméricas de Ligação ao GTP , Proteínas RGS , Arabidopsis/metabolismo , Fosforilação , Proteínas de Arabidopsis/metabolismo , Proteoma/metabolismo , Proteínas RGS/química , Proteínas RGS/genética , Proteínas RGS/metabolismo , Transdução de Sinais , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Flagelina/farmacologia , Flagelina/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo
7.
Vaccines (Basel) ; 11(10)2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37896969

RESUMO

Dogs with visceral leishmaniasis play a key role in the transmission cycle of Leishmania infantum to humans in the urban environment. There is a consensus regarding the importance of developing a vaccine to control this disease. Despite many efforts to develop a protective vaccine against CVL, the ones currently available, Leish-tec® and LetiFend®, have limited effectiveness. This is due, in part, to the complexity of the immune response of the naturally infected dogs against the parasite and the complexity of the parasite transmission cycle. Thus, strategies, such as the development of a transmission-blocking vaccines (TBVs) already being applied to other vector-borne diseases like malaria and dengue, would be an attractive alternative to control leishmaniasis. TBVs induce the production of antibodies in the vertebrate host, which can inhibit parasite development in the vector and/or interfere with aspects of vector biology, leading to an interruption of parasite transmission. To date, there are few TBV studies for CVL and other leishmaniasis forms. However, the few studies that exist show promising results, thus justifying the further development of this approach.

8.
Clin Breast Cancer ; 23(8): 835-846, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37806915

RESUMO

Vulvo-vaginal atrophy (VVA) or genitourinary syndrome of menopause (GSM) is a common condition among breast cancer (BC) patients, especially those undergoing antiestrogen therapy. Despite being an option in refractory cases, the safety of hormonal treatment remains uncertain in this population. The aim of this study was to review the safety and serum estrogen levels of hormonal therapy in patients with BC history presenting with VVA symptoms. Pubmed, Embase, and Cochrane were searched for studies comparing different hormonal treatment options for VVA in breast cancer survivors. Statistical analysis was performed using a random effects model and heterogeneity using Cochran's Q-statistic and the I2 index. We included 17 studies, of which 5 were randomized controlled trials (RCTs). Treatment modalities included in this study were topical vaginal estradiol and estriol preparations, vaginally applied testosterone, DHEA, and ospemifene. We found that, among patients treated with the estriol and estradiol preparations, there was an average increase of 7.67 pg/mL (SMD 7.67 pg/mL; 95% CI -1.00, 16.35; p < .001). Analysis of the testosterone group found temporary peaks of serum estradiol levels, but 1 study showed persistent elevation above normal postmenopausal levels. One study with prasterone revealed no elevation of serum estradiol concentration. One study with ospemifene demonstrated no increase in the risk of BC recurrence. In conclusion, among treatments available for BC survivors, low-dose vaginal estrogen showed the smallest changes in serum estradiol levels and had the most evidence, but safety remains unclear, especially for patients on aromatase inhibitors. Alternative treatments such as ospemifene need more data supporting safety and efficacy. These results suggest that concerns related to cancer recurrence should keep aiming for the lowest possible concentration.


Assuntos
Neoplasias da Mama , Sobreviventes de Câncer , Doenças Vaginais , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Recidiva Local de Neoplasia/patologia , Doenças Vaginais/patologia , Vagina/patologia , Estradiol , Sobreviventes , Testosterona/uso terapêutico , Estrogênios/uso terapêutico , Atrofia/tratamento farmacológico , Estriol/efeitos adversos
9.
J R Soc Interface ; 20(206): 20230266, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37700710

RESUMO

The smallest flying insects often have bristled wings resembling feathers or combs. We combined experiments and three-dimensional numerical simulations to investigate the trade-off between wing weight and drag generation. In experiments of bristled strips, a reduced physical model of the bristled wing, we found that the elasto-viscous number indicates when reconfiguration occurs in the bristles. Analysis of existing biological data suggested that bristled wings of miniature insects lie below the reconfiguration threshold, thus avoiding drag reduction. Numerical simulations of bristled strips showed that there exist optimal numbers of bristles that maximize the weighted drag when the additional volume due to the bristles is taken into account. We found a scaling relationship between the rescaled optimal numbers and the dimensionless bristle length. This result agrees qualitatively with and provides an upper bound for the bristled wing morphological data analysed in this study.


Assuntos
Insetos , Asas de Animais , Animais , Asas de Animais/anatomia & histologia
10.
Sci Adv ; 9(23): eadg8861, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37285435

RESUMO

Knots are the weakest link in surgical sutures, serving as mechanical ligatures between filaments. Exceeding their safe operational limits can cause fatal complications. The empirical nature of present guidelines calls for a predictive understanding of the mechanisms underlying knot strength. We identify the primary ingredients dictating the mechanics of surgical sliding knots, highlighting the previously overlooked but critical effect of plasticity and its interplay with friction. The characterization of surgeon-tied knots reveals the relevant ranges of tightness and geometric features. Using model experiments coupled with finite element simulations, we uncover a robust master curve for the target knot strength versus the tying pre-tension, number of throws, and frictional properties. These findings could find applications in the training of surgeons and robotic-assisted surgical devices.


Assuntos
Técnicas de Sutura , Suturas , Fricção , Resistência à Tração , Teste de Materiais
11.
Int J Mol Sci ; 24(10)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37240253

RESUMO

Brazil has a crucial role in global food security and biodiversity, boasting one of the largest agricultural areas and two globally vital biomes, the Amazon and the Atlantic Forest [...].


Assuntos
Ecossistema , Florestas , Brasil , Biodiversidade , Plantas/genética
12.
J Exp Biol ; 226(9)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37042277

RESUMO

The bodies of most swimming fishes are very flexible and deform as result of both external fluid dynamic forces and internal musculoskeletal forces. If fluid forces change, the body motion will also change unless the fish senses the change and alters its muscle activity to compensate. Lampreys and other fishes have mechanosensory cells in their spinal cords that allow them to sense how their body is bending. We hypothesized that lampreys (Petromyzon marinus) actively regulate body curvature to maintain a fairly constant swimming waveform even as swimming speed and fluid dynamic forces change. To test this hypothesis, we measured the steady swimming kinematics of lampreys swimming in normal water, and water in which the viscosity was increased by 10 or 20 times by adding methylcellulose. Increasing the viscosity over this range increases the drag coefficient, potentially increasing fluid forces up to 40%. Previous computational results suggested that if lampreys did not compensate for these forces, the swimming speed would drop by about 52%, the amplitude would drop by 39%, and posterior body curvature would increase by about 31%, while tail beat frequency would remain the same. Five juvenile sea lampreys were filmed swimming through still water, and midlines were digitized using standard techniques. Although swimming speed dropped by 44% from 1× to 10× viscosity, amplitude only decreased by 4%, and curvature increased by 7%, a much smaller change than the amount we estimated if there was no compensation. To examine the waveform overall, we performed a complex orthogonal decomposition and found that the first mode of the swimming waveform (the primary swimming pattern) did not change substantially, even at 20× viscosity. Thus, it appears that lampreys are compensating, at least partially, for the changes in viscosity, which in turn suggests that sensory feedback is involved in regulating the body waveform.


Assuntos
Lampreias , Petromyzon , Animais , Lampreias/fisiologia , Natação/fisiologia , Fenômenos Biomecânicos/fisiologia , Viscosidade , Peixes/fisiologia
13.
Ann Vasc Surg ; 94: 205-212, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36868457

RESUMO

BACKGROUND: R2CHA2DS2-VA score has been used to predict short and long-term outcomes in many cardiovascular diseases. This study aims to validate the R2CHA2DS2-VA score as a long-term major adverse cardiovascular events (MACE) predictor after carotid endarterectomy (CEA). Secondary outcomes were also assessed regarding the incidence of all-cause mortality, acute myocardial infarction (AMI), major adverse limb events (MALE), and acute heart failure (AHF). METHODS: From January 2012 to December 2021, patients (n = 205) from a Portuguese tertiary care and referral center that underwent CEA with regional anesthesia (RA) for carotid stenosis (CS) were selected from a previously collected prospective database, and a posthoc analysis was performed. Demographics and comorbidities were registered. Clinical adverse events were assessed 30 days after the procedure and in the subsequent long-term surveillance period. Statistical analysis was performed by the Kaplan-Meier method and Cox proportional hazards regression. RESULTS: Of the patients enrolled, 78.5% were males with a mean age of 70.44 ± 8.9 years. Higher scores of R2CHA2DS2-VA were associated with long-term MACE (adjusted hazard ratio (aHR) 1.390; 95% confidence interval (CI) 1.173-1.647); and mortality (aHR 1.295; 95% CI 1.08-1.545). CONCLUSIONS: This study demonstrated the potential of the R2CHA2DS2-VA score to predict long-term outcomes, such as AMI, AHF, MACE, and all-cause mortality, in a population of patients submitted to carotid endarterectomy.


Assuntos
Doenças Cardiovasculares , Estenose das Carótidas , Endarterectomia das Carótidas , Insuficiência Cardíaca , Infarto do Miocárdio , Acidente Vascular Cerebral , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Endarterectomia das Carótidas/efeitos adversos , Doenças Cardiovasculares/etiologia , Fatores de Risco , Resultado do Tratamento , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Infarto do Miocárdio/etiologia , Fatores de Risco de Doenças Cardíacas , Insuficiência Cardíaca/etiologia , Acidente Vascular Cerebral/etiologia , Medição de Risco , Estudos Retrospectivos
14.
Philos Trans A Math Phys Eng Sci ; 381(2244): 20220029, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36774950

RESUMO

We investigate the mechanics of bistable, hard-magnetic, elastic beams, combining experiments, finite-element modelling (FEM) and a reduced-order theory. The beam is made of a hard magneto-rheological elastomer, comprising two segments with antiparallel magnetization along the centreline, and is set into a bistable curved configuration by imposing an end-to-end shortening. Reversible snapping is possible between these two stable states. First, we experimentally characterize the critical field strength for the onset of snapping, at different levels of end-to-end shortening. Second, we perform three-dimensional FEM simulations using the Riks method to analyse high-order deformation modes during snapping. Third, we develop a reduced-order centreline-based beam theory to rationalize the observed magneto-elastic response. The theory and simulations are validated against experiments, with an excellent quantitative agreement. Finally, we consider the case of combined magnetic loading and poking force, examining how the applied field affects the bistability and quantifying the maximum load-bearing capacity. Our work provides a set of predictive tools for the rational design of one-dimensional, bistable, magneto-elastic structural elements. This article is part of the theme issue 'Probing and dynamics of shock sensitive shells'.

15.
Philos Trans A Math Phys Eng Sci ; 381(2244): 20220298, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36774961

RESUMO

The buckling of spherical shells is plagued by a strong sensitivity to imperfections. Traditionally, imperfect shells tend to be characterized empirically by the knockdown factor, the ratio between the measured buckling strength and the corresponding classic prediction for a perfect shell. Recently, it has been demonstrated that the knockdown factor of a shell containing a single imperfection can be predicted when there is detailed a priori knowledge of the defect geometry. Still, addressing the analogous problem for a shell containing many defects remains an open question. Here, we use finite element simulations, which we validate against precision experiments, to investigate hemispherical shells containing a well-defined distribution of imperfections. Our goal is to characterize the resulting knockdown factor statistics. First, we study the buckling of shells containing only two defects, uncovering non-trivial regimes of interactions that echo existing findings for cylindrical shells. Then, we construct statistical ensembles of imperfect shells, whose defect amplitudes are sampled from a lognormal distribution. We find that a 3-parameter Weibull distribution is an excellent description for the measured statistics of knockdown factors, suggesting that shell buckling can be regarded as an extreme-value statistics phenomenon. This article is part of the theme issue 'Probing and dynamics of shock sensitive shells'.

16.
J Cardiovasc Surg (Torino) ; 64(1): 48-57, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36168948

RESUMO

BACKGROUND: Aortoiliac peripheral artery disease may lead to disabling lower limb claudication or to lower limb chronic threatening ischemia, which is associated with increased short and long-term morbi-mortality. The red blood cell distribution width-coefficient of variation (RDW-CV) has been able to predict outcomes in other atherosclerotic diseases, such as myocardial infarction and stroke. The main objective of this study was to assess the predictive ability of perioperative RDW-CV in accurately predicting short and long-term major adverse cardiovascular events (MACE) and all-cause mortality in patients submitted to aortoiliac revascularization due to extensive aortoiliac atherosclerotic disease. METHODS: From 2013 to 2020, patients who underwent aortoiliac revascularization due to severe aortoiliac disease were included in a prospective cohort. Blood samples were taken preoperatively and the patient's demographics, comorbidities, and postoperative outcomes were assessed. A multivariate Cox regression model was used to adjust for confounding and assess the independent effect of these prognostic factors on the outcomes. RESULTS: The study group included 107 patients. Median follow-up was 57 (95% CI: 34.4-69.6) months. Preoperative RDW-CV was increased in thirty-eight patients (35.5%). Increased RDW-CV was associated with congestive heart failure - adjusted odds ratio of 5.043 (95% CI: 1.436-17.717, P=0.012). It could predict long-term occurrence of MACE (adjusted hazard ratio [aHR] 1.065, 95% CI: 1.014-1.118, P=0.011), all-cause mortality (aHR=1.069, 95% CI: 1.014-1.126, P=0.013), acute heart failure (AHF) (aHR=1.569, 95% CI: 1.179-2.088, P=0.002), and stroke (aHR=1.343, 95% CI: 1.044-1.727, P=0.022). CONCLUSIONS: RDW is a widely available and low-cost marker that was able to independently predict long-term AHF, stroke, MACE, and all-cause mortality in patients with extensive aortoiliac disease submitted to revascularization. This biomarker could help assess which patients would likely benefit from stricter follow-up in the long-term.


Assuntos
Insuficiência Cardíaca , Acidente Vascular Cerebral , Humanos , Prognóstico , Estudos Prospectivos , Índices de Eritrócitos , Acidente Vascular Cerebral/epidemiologia , Eritrócitos , Fatores de Risco
17.
Int J Pharm ; 631: 122468, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36503038

RESUMO

Ocular chemical burns are prevalent injuries that must have immediate and effective treatment to avoid complications. Aiming to improve bioavailability and efficacy, a poloxamer-based thermoresponsive in-situ gelling system containing hyaluronic acid and indomethacin was developed. Formulations with different polymeric proportions were screened through rheological measurements resulting in an optimized system (F2) with gelling temperature of 34.2 ± 0.11 °C. Its maximum viscosity varied from 77.33 mPa (25 °C) to 82.95 mPa (34 °C) following a non-Newtonian profile and a pH of 6.86 ± 0.01. No incompatibilities were found after infrared analysis. Polarized light microscopy and cryo-transmission electron microscopy have demonstrated micelles of nano-sized dimensions (21.86 nm) with indomethacin entrapped in the core, forming a polymeric network under heating. In vitro tests revealed a cumulative release of 59.75 ± 3.17 % up to 24 h under a sustained release profile. Results from HET-CAM assay indicated that F2 was well tolerated. Corneal wound healing was significantly faster in animals treated with F2 compared to a commercial formulation and an untreated group. These findings suggests that F2 could be an efficient system to delivery drugs into the ocular surface improving wound healing.


Assuntos
Queimaduras Químicas , Indometacina , Animais , Ácido Hialurônico , Queimaduras Químicas/tratamento farmacológico , Géis , Poloxâmero
18.
Metabolites ; 14(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38248828

RESUMO

Given the remarkable progress in global health and overall quality of life, the significant rise in life expectancy has become intertwined with the surging occurrence of neurodegenerative disorders (NDs). This emerging trend is poised to pose a substantial challenge to the fields of medicine and public health in the years ahead. In this context, Alzheimer's disease (AD) is regarded as an ND that causes recent memory loss, motor impairment and cognitive deficits. AD is the most common cause of dementia in the elderly and its development is linked to multifactorial interactions between the environment, genetics, aging and lifestyle. The pathological hallmarks in AD are the accumulation of ß-amyloid peptide (Aß), the hyperphosphorylation of tau protein, neurotoxic events and impaired glucose metabolism. Due to pharmacological limitations and in view of the prevailing glycemic hypometabolism, the ketogenic diet (KD) emerges as a promising non-pharmacological possibility for managing AD, an approach that has already demonstrated efficacy in addressing other disorders, notably epilepsy. The KD consists of a food regimen in which carbohydrate intake is discouraged at the expense of increased lipid consumption, inducing metabolic ketosis whereby the main source of energy becomes ketone bodies instead of glucose. Thus, under these dietary conditions, neuronal death via lack of energy would be decreased, inasmuch as the metabolism of lipids is not impaired in AD. In this way, the clinical picture of patients with AD would potentially improve via the slowing down of symptoms and delaying of the progression of the disease. Hence, this review aims to explore the rationale behind utilizing the KD in AD treatment while emphasizing the metabolic interplay between the KD and the improvement of AD indicators, drawing insights from both preclinical and clinical investigations. Via a comprehensive examination of the studies detailed in this review, it is evident that the KD emerges as a promising alternative for managing AD. Moreover, its efficacy is notably enhanced when dietary composition is modified, thereby opening up innovative avenues for decreasing the progression of AD.

19.
Hortic Res ; 9: uhac217, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36479580

RESUMO

Botrytis cinerea is responsible for the gray mold disease, severely affecting Vitis vinifera grapevine and hundreds of other economically important crops. However, many mechanisms of this fruit-pathogen interaction remain unknown. The combined analysis of the transcriptome and metabolome of green fruits infected with B. cinerea from susceptible and tolerant genotypes was never performed in any fleshy fruit, mostly because green fruits are widely accepted to be resistant to this fungus. In this work, peppercorn-sized fruits were infected in the field or mock-treated, and berries were collected at green (EL32) stage from a susceptible (Trincadeira) and a tolerant (Syrah) variety. RNAseq and GC-MS data suggested that Syrah exhibited a pre-activated/basal defense relying on specific signaling pathways, hormonal regulation, namely jasmonate and ethylene metabolisms, and linked to phenylpropanoid metabolism. In addition, putative defensive metabolites such as shikimic, ursolic/ oleanolic, and trans-4-hydroxy cinnamic acids, and epigallocatechin were more abundant in Syrah than Trincadeira before infection. On the other hand, Trincadeira underwent relevant metabolic reprogramming upon infection but was unable to contain disease progression. RNA-seq analysis of the fungus in planta revealed an opposite scenario with higher gene expression activity within B. cinerea during infection of the tolerant cultivar and less activity in infected Trincadeira berries. The results suggested an activated virulence state during interaction with the tolerant cultivar without visible disease symptoms. Together, this study brings novel insights related to early infection strategies of B. cinerea and the green berry defense against necrotrophic fungi.

20.
J. bras. nefrol ; 44(4): 533-542, Dec. 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1421922

RESUMO

Abstract Introduction: Kidney transplant (KT) recipients have a high risk for adverse outcomes from infections, such as COVID-19. Methods: We have retrospectively reviewed all KT recipients with documented COVID-19 between March 1, 2020, and March 15, 2021, and analyzed patients' characteristics, clinical course, treatment, and outcomes. Results: We identified 123 patients, 72% were male, with a mean age of 54.5±13.0 years. Twenty percent were asymptomatic, 7% had a nosocomial transmission, and 36% of the remainder required hospitalization. Almost all admitted patients received oxygen, 30% required invasive mechanical ventilation (IMV), more than a half had acute kidney injury, with 10% requiring dialysis, and 20% died. Incidence was comparable to that of the Portuguese population, but the mortality rate was almost four times higher (SMR of 3.768 (95% CI:1.723-7.154). Higher body mass index (OR 1.275, P=0.001), lower baseline graft function (OR 0.968, P=0.015), and nosocomial transmission (OR 13.836, P=0.019) were associated with oxygen demand, whereas female gender (OR 3.801, P=0.031) and lower baseline kidney graft function (OR 0.955, P=0.005), but not body mass index, were associated with IMV and/or death. Conclusion: Mortality rate in KT patients was higher than in the general population and lower baseline kidney function was the most consistent marker for adverse outcomes.


Resumo Introdução: Os receptores de transplante renal (TR) apresentam um alto risco para desfechos adversos de infecções, tais como a COVID-19. Métodos: Revisamos retrospectivamente todos os receptores de TR com COVID-19 documentada entre 1º de Março de 2020 e 15 de Março de 2021, e analisamos as características, curso clínico, tratamento e desfechos dos pacientes. Resultados: Identificamos 123 pacientes, 72% do sexo masculino, com uma média de idade de 54,5±13,0 anos. Vinte por cento eram assintomáticos, 7% apresentaram transmissão nosocomial, e 36% do restante necessitaram de internação. Quase todos os pacientes internados receberam oxigênio, 30% necessitaram de ventilação mecânica invasiva (VMI), mais da metade apresentou lesão renal aguda, com 10% necessitando de diálise, e 20% foram a óbito. A incidência foi comparável à da população portuguesa, mas a taxa de mortalidade foi quase quatro vezes superior (TMP de 3,768 (IC 95%: 1,723-7,154). Maior índice de massa corporal (OR 1,275; P=0,001), menor função do enxerto basal (OR 0,968; P=0,015), e transmissão nosocomial (OR 13,836; P=0,019) foram associados à demanda de oxigênio, enquanto sexo feminino (OR 3,801; P=0,031) e menor função do enxerto renal basal (OR 0,955; P=0,005), mas não índice de massa corporal, foram associados à VMI e/ou óbito. Conclusão: A taxa de mortalidade em pacientes com TR foi mais elevada do que na população em geral e a função renal basal mais baixa foi o marcador mais consistente para desfechos adversos.

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