Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 560
Filtrar
1.
Chemosphere ; 274: 129704, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33529946

RESUMO

Research on the environmental impact of plastics, especially on the effect of microplastics (MPs), has become a priority issue in recent years, mainly in terrestrial ecosystems where there is a lack of studies. This work aims to assess the impact of two types of polyethylene MPs, white microbeads (W) and fluorescent blue microbeads (FB), and their interactions with two contaminants, ibuprofen (Ib) and simazine (Sz), on different organisms. A set of bioassays for Vibrio fischeri, Caenorhabditis elegans and Lactuca sativa was carried out, which helped to establish the ecotoxicological impact of those pollutants. C. elegans showed the least sensitivity, while V. fischeri and L. sativa showed a high toxicological response to MPs alone. We found that W and FB induced an inhibition of 27% and 5.79%, respectively, in V. fischeri, and the growth inhibition rates were near 70% in L. sativa for both MPs. MPs exhibited a potential role as contaminant vectors in V. fischeri since the inhibition caused by W-Ib or W-Sz complexes was near 39%. The W-Sz complex significantly reduced leaf development in L. sativa, and a reduction of 30% in seed germination was detected when the complex FB-Sz was tested. This study reveals the importance of designing a complete set of analyses with organisms from different trophic levels, considering the great variability in the effects of MPs and the high number of relevant factors.

2.
Diagn Cytopathol ; 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33600080

RESUMO

BACKGROUND: The Paris system (TPS) for Reporting Urinary Cytology provides a standardized reporting system whose main focus is the diagnosis of high-grade urothelial carcinoma (HGUC). We conducted a study to see the impact of The Paris System on our cytologic diagnoses with associated histology. MATERIALS AND METHODS: We reviewed our pathology database regarding urinary specimens in the year before implementation of The Paris System and the year after. We gathered the data regarding cytologic diagnosis and concurrent/subsequent histology. RESULTS: Over a 1-year period from 2016-2017, 486 urine cytology specimens were identified before implementation of The Paris System and diagnosed as follows: 83% benign/negative, 10% atypical, 2% suspicious, 5% HGUC, 0.2% low grade urothelial neoplasm (LGUN), and 0.2% unsatisfactory. Over a next 1-year period from 2017 to 2018, 602 specimens used TPS and diagnosed as follows: 85% negative for HGUC, 6% atypical, 3% suspicious, 4% HGUC, 0.17% LGUN, and 2% unsatisfactory. Although, not listed as a standardized category in The Paris System, our institution used "Negative for high-grade, cannot rule out low-grade urothelial neoplasm (NHL)" as a subcategory of Negative for HGUC. 4% of the cases fell into this category. Focusing on the Atypical category before TPS, histology was available in 15/49 (31%) cases. Of these, 40% had HGUC. Regarding the Atypical category after TPS, histology was available in 21/36 (58%) cases. Of these, 52% were HGUC. For the NHL category, concurrent histology was available in 13/26 (50%) cases. Of these, 67% were low grade urothelial neoplasms. CONCLUSION: Our study showed that TPS lowered the rate of Atypical from 10% to 6%. After the implementation of TPS, Atypical corresponded to a higher rate of high-grade urothelial carcinoma. Also, the NHL subcategory had a high positive predictive value for diagnosing low grade urothelial neoplasms.

3.
Pediatr Res ; 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469179

RESUMO

The COVID-19 pandemic will leave an indelible mark on the careers of current medical trainees. Given the disruptions to medical education, economic impact on institutions, and the uncertainties around future job prospects, trainees are facing unprecedented challenges. This situation is especially concerning for futures of pediatric physician-scientist trainees, where concerns regarding maintaining the pipeline were well documented prior to the emergence of COVID-19. In this Perspectives article, we leverage the unique expertise of our workgroup to address concerns of physician-scientist trainees and to provide suggestions on how to navigate career trajectories in the post-COVID-19 era. We identified and addressed four major areas of concern: lack of in-person conferences and the associated decrease access to mentors and networking activities, decreased academic productivity, diminished job prospects, and mental health challenges. We also suggest actions for trainees, mentors and educational leaders, and institutions to help support trainees during the pandemic, with a goal of maintaining the pediatric physician-scientist pipeline.

4.
Viruses ; 13(1)2021 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-33477376

RESUMO

Quinacrine (Qx), a molecule used as an antimalarial, has shown anticancer, antiprion, and antiviral activity. The most relevant antiviral activities of Qx are related to its ability to raise pH in acidic organelles, diminishing viral enzymatic activity for viral cell entry, and its ability to bind to viral DNA and RNA. Moreover, Qx has been used as an immunomodulator in cutaneous lupus erythematosus and various rheumatological diseases, by inhibiting phospholipase A2 modulating the Th1/Th2 response. The aim of this study was to evaluate the potential antiviral effect of Qx against denominated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Vero E6 cells. The cytotoxicity of Qx in Vero E6 cells was determined by the MTT assay. Afterwards, Vero E6 cells were infected with SARS-CoV-2 at different multiplicities of infections (MOIs) of 0.1 and 0.01 in the presence of Qx (0-30 µM) to determinate the half maximal effective concentration (EC50). After 48 h, the effect of Qx against SARS-CoV-2 was assessed by viral cytotoxicity and viral copy numbers, the last were determined by digital real-time RT-PCR (ddRT-PCR). Additionally, electron and confocal microscopy of Vero E6 cells infected and treated with Qx was studied. Our data show that Qx reduces SARS-CoV-2 virus replication and virus cytotoxicity, apparently by inhibition of viral ensemble, as observed by ultrastructural images, suggesting that Qx could be a potential drug for further clinical studies against coronavirus disease 2019 (COVID-19) infection.


Assuntos
Antivirais/farmacologia , Quinacrina/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Chlorocebus aethiops , Microscopia Eletrônica de Transmissão , Células Vero , Carga Viral/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos
5.
Stroke ; 52(1): 284-293, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33349013

RESUMO

BACKGROUND AND PURPOSE: Perinatal stroke is a common cause of life-long neurobehavioral compromise. Mesenchymal stromal cells (MSCs) and EPO (erythropoietin) have each demonstrated short-term benefit with delayed administration after stroke, and combination therapy may provide the most benefit. The purpose of this study is to determine the long-term histological and functional efficacy of enhanced, intranasal stem cell therapy (MSC preexposed to EPO) compared with standard MSC or multidose systemic EPO. METHODS: Transient middle cerebral artery occlusion or sham surgery was performed in postnatal day (P) 10 Sprague-Dawley rats, who were treated with single-dose intranasal MSC, MSC preexposed to EPO (MSC/EPO), multidose systemic EPO (EPO3; 1000 u/kg per dose×3 every 72 hours), or cell-conditioned media on P13 (day 3 [P13-P19] for EPO), or on P17 (day 7 [P17-P23] for EPO). At 2 months of age, animals underwent novel object recognition, cylinder rearing, and open field testing to assess recognition memory, sensorimotor function, and anxiety in adulthood. RESULTS: MSC, MSC/EPO, and EPO3 improved brain volume when administered at 3 or 7 days after middle cerebral artery occlusion. MSC/EPO also enhanced long-term recognition memory with either day 3 or day 7 treatment, but EPO3 had the most long-term benefit, improving recognition memory and exploratory behavior and reducing anxiety. CONCLUSIONS: These data suggest that single-dose MSC/EPO and multidose systemic EPO improve long-term neurobehavioral outcomes even when administration is delayed, although EPO was the most effective treatment overall. It is possible that EPO represents a final common pathway for improved long-term repair, although the specific mechanisms remain to be determined.

6.
Bioconjug Chem ; 32(1): 88-93, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33356163

RESUMO

Herein we describe a method to orthogonally remove on-DNA N-Cbz, N-Alloc, N-Allyl, O-Bn, and O-Allyl protecting groups in the presence of other common protecting groups to afford free amines and carboxylic acids, respectively. The developed method uses NaBH4 as the source of hydrogen in the presence of Pd(OAc)2 under DNA aqueous conditions. In addition, under the developed conditions we were able to successfully hydrogenate triple and double bonds to totally saturated compounds. Furthermore, we introduce a new alternative procedure to reduce azides and aromatic nitro compounds to primary amines.

7.
Entropy (Basel) ; 22(12)2020 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-33279925

RESUMO

As training Deep Neural Networks (DNNs) becomes more expensive, the interest in protecting the ownership of the models with watermarking techniques increases. Uchida et al. proposed a digital watermarking algorithm that embeds the secret message into the model coefficients. However, despite its appeal, in this paper, we show that its efficacy can be compromised by the optimization algorithm being used. In particular, we found through a theoretical analysis that, as opposed to Stochastic Gradient Descent (SGD), the update direction given by Adam optimization strongly depends on the sign of a combination of columns of the projection matrix used for watermarking. Consequently, as observed in the empirical results, this makes the coefficients move in unison giving rise to heavily spiked weight distributions that can be easily detected by adversaries. As a way to solve this problem, we propose a new method called Block-Orthonormal Projections (BOP) that allows one to combine watermarking with Adam optimization with a minor impact on the detectability of the watermark and an increased robustness.

8.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1142101

RESUMO

Resumen: El Cáncer de Cuello Uterino (CCU) es un problema de Salud pública a nivel mundial. Su indiscutible asociación con el Virus del papiloma humano (HPV) hace necesario su estudio. El objetivo de este trabajo, es conocer la prevalencia de los diferentes genotipos de HPV, en lesiones pre invasoras de alto grado de malignidad (HSIL) y/o cáncer de cuello uterino. Material y Métodos: Todas las Mujeres que fueron derivadas a pol de TGI del H Clínicas entre enero del 2011 y diciembre de 2012, por un PAP sospechoso de lesión y en las que se confirmó luego un HSIL o cáncer cervical fueron tipificadas. Se recabaron datos de edad, tipo de lesión y genotipificación. La extracción de ADN viral se realizó a partir de muestras cervico vaginales conservadas en medio de transporte comercial (Sacace) mediante el kit QIAamp DNA Mini Kit (QIAGEN). Se buscaron 14 genotipos de alto riesgo. Resultados: Se tipificaron 75 pacientes, 19 con CCU y 56 con HSIL. El HPV 16 fue el más prevalente en un 61,5 % para las infecciones únicas y en un casi 100 % para las múltiples y un 60% para el total de las lesiones, seguido en prevalencia por los HPV 31,33 y 45. El HPV 18 fue muy poco prevalente. Conclusiones: En esta muestra, la prevalencia del HPV 16 está acorde con las publicaciones nacionales siendo el más frecuente. El HPV 18 tiene muy baja prevalencia siendo 2 casos en 75, siempre en infecciones múltiples.


Summary: Cervical Cancer (CC) is a public health problem worldwide. Its indisputable association with the Human Papilloma Virus (HPV) makes its study necessary. The objective of this work is to know the prevalence of the different HPV genotypes, in pre-invasive high-grade malignant lesions (HSIL) and / or cervical cancer. Material and Methods: All women who were referred to Low genital tract service in the Hospital de Clinicas between January 2011 and December 2012, for a PAP suspected of injury and in which HSIL or cervical cancer was later confirmed were typified. Data on age, type of lesion and genotyping were collected. The viral DNA extraction was carried out from cervico-vaginal samples preserved in commercial transport medium (Sacace) using the QIAamp DNA Mini Kit (QIAGEN). 14 high-risk genotypes were searched. Results: 75 patients were typified, 19 with CCU and 56 with HSIL. HPV 16 was the most prevalent in 61.5% for single infections and almost 100% for multiple infections and 60% for all lesions, followed in prevalence by HPV 31,33 and 45. The HPV 18 was very rare. Conclusions: In this sample, the prevalence of HPV 16 is in accordance with national publications, being the most frequent. HPV 18 has a very low prevalence, being 2 cases in 75, always in multiple infections.


Resumo: O câncer cervical é um problema de saúde pública em todo o mundo. E um câncer com uma ligação comprovada com o vírus do papiloma humano. O objetivo é conhecer a prevalência dos diferentes genótipos do HPV em mulheres que apresentam neoplasias pré-invasivas de alto grau e câncer de colo do útero, que foram tratadas e diagnosticadas no Hospital de Clínicas entre janeiro de 2011 e dezembro de 2012. Material e Métodos: o estudo foi realizado em 75 pacientes do Hospital de Clinicas, com diagnóstico histológico de Câncer Cervical e lesões intraepiteliais de alto grau para as quais foi realizado o tipageme do HPV alto risco. Resultados: 75 pacientes foram tipificados, 19 com CCU e 56 com HSIL. O HPV 16 foi o mais prevalente em 61,5% para infecções únicas e quase 100% para infecções múltiplas e 60% para todas as lesões, seguido em prevalência pelo HPV 31,33 e 45. O HPV 18 era muito raro. Conclusões: Nesta amostra, a prevalência do HPV 16 está de acordo com as publicações nacionais, sendo a mais frequente. O HPV 18 tem prevalência muito baixa, sendo 2 casos em 75, sempre em infecções múltiplas.

9.
Rev. esp. drogodepend ; 45(4): 85-116, oct.-dic. 2020. tab
Artigo em Espanhol | IBECS-Express | IBECS | ID: ibc-ET6-1733

RESUMO

OBJETIVO: Identificar factores asociados al consumo de riesgo y abusivo de alcohol en estudiantes de primero de medicina de la Universidad del País Vasco. MATERIALES Y MÉTODO: Estudio observacional, descriptivo y transversal realizado en una muestra de 225 estudiantes (77,8% mujeres) mediante un cuestionario anónimo autoadministrado. Se ha realizado un análisis bivariado y se han construido modelos de regresión logística con tres variables dependientes: borracheras, consumos intensivos (CIA) y consumos de riesgo (CR) de alcohol en el último mes. RESULTADOS: El 46,0% de los estudiantes se había emborrachado en el último mes, el 48,3% era bebedor de riesgo y el 67,2% había realizado consumos intensivos de alcohol. En el modelo final son factores de protección: iniciarse en el consumo de alcohol a los 16 años o más tarde (borracheras OR = 0,409, CIA OR = 0,307, CR OR = 0,233) y vivir con los padres u otros familiares para emborracharse en el último mes (OR = 0,336). Son factores de riesgo: que el mejor amigo/a se haya emborrachado en el mes previo (borracheras OR=6,245, CIA OR=4,438, CR OR = 4,616); ser hombre para las borracheras (OR=2,884) y el CIA (OR = 3,588) y ser mujer para el CR (OR = 4,047); unas altas expectativas para el CIA (OR = 2,660) y el CR (OR = 4,572) y que todos o la mayoría de los amigos/as y compañeros/as se hayan emborrachado (OR = 2,367) o que el mejor amigo/a haya consumido alcohol en el último mes (OR = 10,287) para las borracheras en el mes previo. CONCLUSIONES: Los CR y CIA en el último mes son frecuentes. Las expectativas positivas asociadas al alcohol son moderadamente elevadas y se relacionan fundamentalmente con el estado emocional. Retrasar la edad de inicio es el principal factor de protección, mientras que las borracheras recientes del mejor amigo/a y las altas expectativas positivas asociadas al alcohol son los principales y más consistentes factores de riesgo


OBJECTIVE: To identify factors associated with the risk of abuse of alcohol consumption in first year medical students at the Basque Country University. MATERIALS AND METHOD: An observational, descriptive and cross-sectional study was carried out in a sample of 225 students (77.8% women) using a self-administered anonymous questionnaire. A bivariate analysis was carried out and logistic regression models were constructed with three dependent variables: drunkenness, binge drinking (BD) and risk of consumption (RC) of alcohol in the last month. RESULTS: 46.0% of the students had got drunk in the last month, 48.3% were risk drinkers and 67.2% had been binge drinking. In the final model the protective factors were: start drinking alcohol at 16 years or later (drunkenness OR = 0.409, BD OR = 0.307, RC OR = 0.233) and live with the parents or other relatives for drunkenness in the last month (OR = 0.336). The following are risk factors: that the best friend has got drunk in the previous month (drunkenness OR = 6.245, BD OR=4.438, CR OR = 4.616); being male for drunkenness (OR = 2,884) and CIA (OR = 3,588) and being woman for the CR (OR = 4,047); high expectations for the CIA (OR = 2,660) and the CR (OR = 4,572) and that all or most of the friends and peers have got drunk (OR=2.367) or that the best friend has consumed alcohol in the last month (OR = 10.287) for drunkenness in the previous month. CONCLUSIONS: CR and CIA in the last month are frequent. The positive expectations associated with alcohol are moderately high and are fundamentally related with the emotional state. Delaying the age of onset is the main protective factor, while recent drunkenness of the best friend and the high positive expectations associated with alcohol are the main and most consistent risk factors

10.
Exp Parasitol ; 220: 108033, 2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33166530

RESUMO

Infection with Leishmania infantum causes the disease visceral leishmaniasis (VL), which is a serious clinical and veterinary problem. The drugs used to treat canine leishmaniasis (CanL) do not cause complete parasite clearance; they can be toxic, and emerging drug resistance in parasite populations limits their clinical utility. Therefore, in this study we have evaluated the toxicity and efficacy of joint treatment with a 1:1 mixture of sodium stibogluconate-NIV (SSG-NIV, 10 mg Sbv/day) and paromomycin-NIV (PMM-NIV, 10 mg PMM/kg/day), given intravenously daily for seven days from day 270 post-infection, to nine-month-old female beagle dogs (n = 6) experimentally infected with Leishmania infantum. Treatment significantly improved the clinical symptoms of VL infection in all the treated dogs, reduced parasite burdens in lymph nodes and bone marrow, and all symptomatic treated dogs, were asymptomatic at 90 days post-treatment. Treatment was associated with a progressive and significant decrease in specific IgG anti-Leishmania antibodies using parasite soluble antigen (p < 0.01) or rK39 (p < 0.01) as the target antigen. In addition, all dogs were classified as parasite negative based on Leishmania nested PCR and quantitative real time PCR tests and as well as an inability to culture of promastigote parasites from lymph nodes and bone marrow tissue samples taken at day 90 post-treatment. However, treatment did not cure the dogs as parasites were detected at 10 months post-treatment, indicating that a different dosing regimen is required to cause long term cure or prevent relapse.

11.
QJM ; 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33151302

RESUMO

BACKGROUND: B-lines have been associated with adverse clinical outcomes in patients with heart failure (HF) when found at hospital discharge or during outpatient visits. Whether lung unltrasound (LUS) assessed B-lines may predict in-hospital mortality in patients with acute HF is still undetermined. AIM: To evaluate the association between B-lines on admission and in-hospital mortality among patients admitted with acute HF. METHODS: Hand-held LUS was used to examine patients with acute HF. LUS was performed in 8 chest zones with a pocket ultrasound device and analyzed offline. The association between B-lines and in-hospital mortality was assessed using Cox regression models. RESULTS: We included 62 patients with median age 56 years, 69.4% men, and median left ventricle ejection fraction 25%. The sum of B-lines ranged from 0 to 53 (median 6.5). An optimal ROC-determined cut-off of ≥ 19 B-lines demonstrated a sensitivity of 57% and a specificity of 86% (AUC 0.788) for in-hospital mortality. The incremental prognostic value of LUS when compared with lung crackles or peripheral edema by integrated discrimination improvement was 12.96% (95% CI: 7.0, 18.8, p = 0.02). Patients with ≥19 B-lines had a four-fold higher risk of in-hospital mortality (HR 4.38; 95% CI: 1.37, 13.95, p < 0.01). CONCLUSION: In patients admitted with acute HF, point-of-care LUS measurements of pulmonary congestion (B-lines) are associated with in-hospital mortality.

12.
J Orthop Res ; 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33146417

RESUMO

In total ankle arthroplasty, the interaction at the joint between implant and bone is driven by a complex loading environment. Unfortunately, little is known about the loads at the ankle during daily activities since earlier attempts use two- or three-dimensional models to explore simplified joint mechanics. Our goal was to develop a framework to calculate multi-axial loads at the joint during simulated level walking following total ankle arthroplasty. To accomplish this, we combined robotic simulations of level walking at one-quarter bodyweight in three cadaveric foot and ankle specimens with musculoskeletal modeling to calculate the multi-axial forces and moments at the ankle during the stance phase. The peak compressive forces calculated were between 720 and 873 N occurring around 77%-80% of stance. The peak moment, which was the internal moment for all specimens, was between 6.1 and 11.6 N m and occurred between 72% and 88% of the stance phase. The peak moment did not necessarily occur with the peak force. The ankle joint loads calculated in this study correspond well to previous attempts in the literature; however, our robotic simulator and framework provide an opportunity to resolve the resultant three-dimensional forces and moments as others have not in previous studies. The framework may be useful to calculate ankle joint loads in cadaveric specimens as the first step in evaluating bone-implant interactions in total ankle replacement using specimen specific inputs. This approach also provides a unique opportunity to evaluate changes in joint loads and kinematics following surgical interventions of the foot and ankle.

13.
PLoS One ; 15(11): e0242889, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253280

RESUMO

All 4 dengue viruses (DENV) cause sporadic outbreaks of human disease in the Rio Grande Valley along the US-Mexico border. In addition, West Nile virus (WNV) is enzootic in most border communities, and is the only arbovirus known to cause human disease in the El Paso, Texas community. In an effort to determine if DENV were also endemic in the El Paso community, a serosurvey was conducted among mothers at the time of delivery of their babies in selected hospitals. Cord-blood plasma samples obtained from mothers were tested for DENV antibody by an enzyme-linked immuno-sorbent assay (ELISA), plaque reduction neutralization test (PRNT) and a multiplex microsphere immunoassay. All DENV antibody positive plasma samples were also tested for WNV antibody by the same assays to consider the possibility that DENV antibody positive samples reflected WNV cross reactive antibody. The results indicated that 0.74% (11/1,472) of the mothers had a previous DENV infection and that 3.3% (48/1,472) had a previous WNV infection. Of these mothers, 0.20% (3/1,472) had antibody to both DENV and WNV as evidence of infection by both viruses. The results indicated that 0.2% (3/1472) of the mothers were positive for antibody to only WNV envelope, thus suggesting an undetermined flavivirus infection. Although 6 of the 11 DENV antibody positive mothers did not have a history of travel to a DENV endemic country, the findings of this survey provided further evidence of local transmission of WNV and suggested the possibility of focal autochthonous transmission of DENV in the El Paso community.

14.
J Avian Med Surg ; 34(3): 217-228, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33099974

RESUMO

The application and evaluation of highly efficient chromatographic techniques with tandem mass spectrometry for the detection and quantitation of 108 pesticides and metabolites, some considered persistent organic pollutants, was performed in muscle samples obtained from 25 birds of prey belonging to the families Accipitridae, Falconidae, and Strigidae presented dead in 2013 to Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat, in Madrid, Spain. Pesticides with prohibited use were detected at high concentrations in the muscle samples analyzed. Based on its high sensitivity to detect pesticides in muscle, the described chromatographic techniques with tandem mass spectrometry should be considered an alternative testing methodology to those commonly used for routine application in ecotoxicological forensic research.

15.
J Orthop Res ; 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33030768

RESUMO

Finite element (FE) models to evaluate the burden placed on the interaction between total ankle arthroplasty (TAA) implants and the bone often rely on peak axial forces. However, the loading environment of the ankle is complex, and it is unclear whether peak axial forces represent a challenging scenario for the interaction between the implant and the bone. Our goal was to determine how the loads and the design of the fixation of the tibial component of TAA impact the interaction between the implant and the bone. To this end, we developed a framework that integrated robotic cadaveric simulations to determine the ankle kinematics, musculoskeletal models to determine the ankle joint loads, and FE models to evaluate the interaction between TAA and the bone. We compared the bone-implant micromotion and the risk of bone failure of three common fixation designs for the tibial component of TAA: spikes, a stem, and a keel. We found that the most critical conditions for the interaction between the implant and the bone were dependent on the specimen and the fixation design, but always involved submaximal forces and large moments. We also found that while the fixation design influenced the distribution and the peak value of bone-implant micromotion, the amount of bone at risk of failure was specimen dependent. To account for the most critical conditions for the interaction between the implant and the bone, our results support simulating multiple specimens under complex loading profiles that include multiaxial moments and span entire activity cycles.

16.
Toxicol Sci ; 178(2): 338-346, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32946573

RESUMO

In artisanal and small-scale gold mining, occupational exposure to mercury (Hg) vapor is related to harmful effects on several organs, including the kidneys. We previously reported significantly increased levels of Hg in blood and urine despite normal kidney function in individuals from Colombia occupationally exposed to Hg compared with those nonexposed. We evaluated the contribution of 4 genetic variants in key genes encoding the transporters solute carrier (SLC; rs4149170 and rs4149182) and ATP-binding cassette(ABC; rs1202169 and rs1885301) in the pathogenesis of nephrotoxicity due to Hg exposure in these groups. Regression analysis was performed to determine the association between the blood- and urine-Hg concentration with SLC and ABC polymorphisms in 281 Colombian individuals (160 exposed and 121 nonexposed to Hg). We found an enrichment of ABCB1 rs1202169-T allele in the exposed group (p = .011; OR= 2.05; 95% CI = 1.18-3.58) compared with the nonexposure group. We also found that carriers of SLC22A8 rs4149182-G and ABCB1 rs1202169-T alleles had a higher urinary clearance rate of Hg than noncarriers (ß = 0.13, p = .04), whereas carriers of SLC22A6 rs4149170-A and ABCB1 rs1202169-C alleles showed abnormal levels of estimated glomerular filtration rate (ß = -84.96, p = .040) and beta-2-microglobulin (ß = 743.38, p < .001). Our results suggest that ABCB1 rs1202169 and its interaction with SLC22A8 rs4149182 and SLC22A6 rs4149170 could mitigate Hg nephrotoxicity by controlling the renal proximal tubule cell accumulation of inorganic Hg. This will be useful to estimate the risk of kidney toxicity associated to Hg and the genetic selection to aid adaptation to Hg-rich environments.

17.
Expert Rev Respir Med ; : 1-13, 2020 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-32902367

RESUMO

INTRODUCTION: The exponential growth of SARS-CoV-2 virus transmission during the first months of 2020 has placed substantial pressure on most health systems around the world. The complications derived from the novel coronavirus disease (COVID-19) vary due to comorbidities, sex and age, with more than 50% of the patients requiring some level of intensive care developing acute respiratory distress syndrome (ARDS). The authors carried out an extensive and comprehensive literature review on SARS-CoV-2 infection, the clinical, pathological, and radiological presentation as well as the current treatment strategies. AREAS COVERED: Various complications caused by SARS-CoV-2 infection have been identified, the most lethal being the acute respiratory distress syndrome, caused most likely by the presence of severe immune cell response and the concomitant alveolus inflammation. The new treatment strategies are updated, and the analysis of the physiopathology is included in this review. EXPERT OPINION: ARDS is one of the most frequent complications in patients with COVID-19. Information regarding the etiology and physiopathology are still unfolding and for the prevention and amelioration, good clinical management, adequate ventilatory support and the use of systemic corticoids seem to be the most efficient way to reduce mortality and to reduce hospital lengths.

19.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 76(Pt 1): 108-121, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32831246

RESUMO

The structures of xSrO-(100 - x)TeO2 (x = 5, 7.5, 8.5 and 10 mol.%) glass, anti-glass and crystalline samples were studied by high-energy X-ray diffraction (HEXRD), reverse Monte Carlo (RMC) simulations, atomic pair distribution function analysis and Fullprof Rietveld refinement. The atomic pair distributions show the first peak at 1.90 Šdue to the Te-O equatorial bonds and the Te-O peak is asymmetrical due to the range of Te-O bond lengths in glass, anti-glass and crystalline samples. The short-range structural properties of glasses such as Te-O bond lengths, Te-O speciation, Te-Te distances and O-Te-O bond angle distributions were determined by RMC simulations. The average Te-O coordination number (NTe-O) for 5SrO-95TeO2 glass is 3.93 which decreases to 3.59 on increasing the SrO concentration to 10 mol.%. The changes in NTe-O revealed that the glass network predominantly contains TeO4 units with a small amount of TeO3 units and there is a structural transformation TeO4 → TeO3 with an increase in SrO concentration. The O-Te-O bond angle distributions have a peak at 79° and reveal that the Oequatorial-Te-Oequatorial bonds are the most abundant linkages in the tellurite network. Two glass samples containing 7.5 and 8.5 mol.% of SrO were annealed at 350°C for 1 h to produce anti-glass phases; they were further annealed at 450°C for 4 h to transform them into crystalline phases. The anti-glass samples are disordered cubic SrTe5O11 and the disordered monoclinic SrTeO3 phases, whereas the crystalline samples contain monoclinic SrTeO3 and the orthorhombic TeO2 phases. The unit-cell parameters of the anti-glass and crystalline structures were determined by Fullprof Rietveld refinement. Thermal studies found that the glass transition temperature increases with an increase in SrO mol.% and the results on the short-range structure of glasses from Raman spectroscopy are in agreement with the RMC findings.

20.
Sci Total Environ ; 747: 141114, 2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-32771780

RESUMO

Peru has one of the fastest-growing economies in Latin America, but there are concerns regarding how long this can be sustained. Negative environmental impacts are increasing due to the pressures of a growing urban population and competition for natural resources. This study explores stakeholder perceptions linked to nexus governance in the context of integrated management of natural resources, particularly water, and the environmental, socio-economic and governance challenges constraining the achievement of UN Sustainable Development Goals (SDGs). Our analysis focused on the urban and rural areas associated with the city of Arequipa, an economically dynamic region subject to extreme levels of water stress. Face-to-face interviews with key informants were conducted to identify mechanisms that have enhanced successful multi-sectoral collaboration, and to assess challenges in promoting sustainable economic development. A workshop prioritised the identified challenges and an online survey was then used to assess stakeholder interest in and influence over nexus governance of water with other natural resources. Stakeholder mapping revealed a complex network of actors involved in nexus governance, where successful collaboration could be promoted through formal and informal mechanisms, including exemplar policies and initiatives across sectors and actors. Shared visions between stakeholders were identified as well as contradictory priorities relating to the sustainable management of natural resources. A key finding that emerged was the need to promote adaptation in water and land management (SDG 6) due to perceived impacts of extreme climate events (SDG 13), urban population growth (SDG 11), and increased sectoral water demands. This situation in combination with poor governance and lack of planning has exposed the vulnerability of Arequipa water supply system to future shocks. Urgent action will be needed to raise stakeholder awareness, strengthen governance and enforcement, and agree on a collective vision for integrated land and water planning if the SDGs are to be achieved.


Assuntos
Desenvolvimento Sustentável , Água , Conservação dos Recursos Naturais , Peru , Abastecimento de Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA