691 research outputs found
Dynamic convergent shock compression initiated by return current in high-intensity laser solid interactions
We investigate the dynamics of convergent shock compression in the solid wire
targets irradiated by an ultra-fast relativistic laser pulse. Our
Particle-in-Cell (PIC) simulations and coupled hydrodynamic simulations reveal
that the compression process is initiated by both magnetic pressure and surface
ablation associated with a strong transient surface return current with the
density in the order of 1e17 A/m^2 and a lifetime of 100 fs. The results show
that the dominant compression mechanism is governed by the plasma ,
i.e., the ratio of the thermal pressure to magnetic pressure. For small radii
and low atomic number Z wire targets, the magnetic pressure is the dominant
shock compression mechanism. As the target radius and atomic number Z increase,
the surface ablation pressure is the main mechanism to generate convergent
shocks based on the scaling law. Furthermore, the indirect experimental
indication of the shocked hydrogen compression is provided by measuring the
evolution of plasma expansion diameter via optical shadowgraphy. This work
could offer a novel platform to generate extremely high pressures exceeding
Gbar to study high-pressure physics using femtosecond J-level laser pulses,
offering an alternative to the nanosecond kJ laser pulse-initiated and pulse
power Z-pinch compression methods
Nuevos datos cronoestratigráficos de la Fm. Marismas (Bajo Guadalquivir)
La Formación Marismas forma la parte superior del relleno sedimentario del sector SW de la cuenca del Guadalquivir. Los datos previos sobre el sondeo Lebrija, indicaban que la parte más alta de esta formación tenía edades de hasta 9.6 kyr BP y en la parte inferior eran cercanas o fuera del rango del radiocarbono, pero posterior a la reversión
Brunhes-Matuyama. En este trabajo se aportan 17 nuevas dataciones realizadas mediante racemización de aminoácidos en valvas de ostrácodos en este mismo sondeo, con el fin de
completar la cronología y el modelo de edad de la parte superior e inferior de la Fm Marismas. El resultado indica que el tramo situado por debajo del metro 56, arroja edades
que oscilan entre 164685±14110 y 202830±30255, que se correlacionan con los estadios isotópicos marinos MIS 6-7 del Pleistoceno medio, edad sensiblemente más baja a las inferidas para esta formación en otros puntos de la Cuenca del bajo GuadalquivirEste trabajo se ha realizado dentro del proyecto Guadaltyc (Impacto del clima y la tectónica en el registro sedimentario de la Cuenca del Guadalquivir, (CGL2012-30875).Peer Reviewe
Machine learning based prediction of squamous cell carcinoma in ex vivo confocal laser scanning microscopy
Image classification with convolutional neural networks (CNN) offers an unprecedented opportunity to medical imaging. Regulatory agencies in the USA and Europe have already cleared numerous deep learning/machine learning based medical devices and algorithms. While the field of radiology is on the forefront of artificial intelligence (AI) revolution, conventional pathology, which commonly relies on examination of tissue samples on a glass slide, is falling behind in leveraging this technology. On the other hand, ex vivo confocal laser scanning microscopy (ex vivo CLSM), owing to its digital workflow features, has a high potential to benefit from integrating AI tools into the assessment and decision-making process. Aim of this work was to explore a preliminary application of CNN in digitally stained ex vivo CLSM images of cutaneous squamous cell carcinoma (cSCC) for automated detection of tumor tissue. Thirty-four freshly excised tissue samples were prospectively collected and examined immediately after resection. After the histologically confirmed ex vivo CLSM diagnosis, the tumor tissue was annotated for segmentation by experts, in order to train the MobileNet CNN. The model was then trained and evaluated using cross validation. The overall sensitivity and specificity of the deep neural network for detecting cSCC and tumor free areas on ex vivo CLSM slides compared to expert evaluation were 0.76 and 0.91, respectively. The area under the ROC curve was equal to 0.90 and the area under the precision-recall curve was 0.85. The results demonstrate a high potential of deep learning models to detect cSCC regions on digitally stained ex vivo CLSM slides and to distinguish them from tumor-free skin
Bringing value to the chemical industry from capture, storage and use of CO2: A dynamic LCA of formic acid production
Low carbon options for the chemical industry include switching from fossil to renewable energy, adopting new low-carbon production processes, along with retrofitting current plants with carbon capture for ulterior use (CCU technologies) or storage (CCS). In this paper, we combine a dynamic Life Cycle Assessment (d-LCA) with economic analysis to explore a potential transition to low-carbon manufacture of formic acid. We propose new methods to enable early technical, environmental and economic assessment of formic acid manufacture by electrochemical reduction of CO2 (CCU), and compare this production route to the conventional synthesis pathways and to storing CO2 in geological storage (CCS). Both CCU and CCS reduce carbon emissions in particular scenarios, although the uncertainty in results suggests that further research and scale-up validation are needed to clarify the relative emission reduction compared to conventional process pathways. There are trade-offs between resource security, cost and emissions between CCU and CCS systems. As expected, the CCS technology yields greater reductions in CO2 emissions than the CCU scenarios and the conventional processes. However, compared to CCS systems, CCU has better economic potential and lower fossil consumption, especially when powered by renewable electricity. The integration of renewable energy in the chemical industry has an important climate mitigation role, especially for processes with high electrical and thermal energy demands.The authors are grateful for the funding of the Spanish Ministry of Economy and Competitiveness through the Projects CTM2016-76176-C2-1-R (AEI/FEDER, UE) and CTQ2016-76231-C2-1-R (AEI/FEDER, UE). The UCL team would like to acknowledge funding from the UK Natural Environment Research Council through the project Comparative assessment and region-specific optimisation of GGR, NERC Reference: NE/P019900/1. Rubén Aldaco thanks the Ministry of Sciences, Innovation and Universities of Spanish Government for their financial support via the research fellowship Salvador de Madariaga Program (PRX18/00027)
Usefulness of analysis of cerebrospinal fluid for the diagnosis of neurotransmitters and pterin defects and glucose and folate transport deficiencies across blood brain barrier
Med Clin (Barc). 2006 Jun 17;127(3):81-5.
[Usefulness of analysis of cerebrospinal fluid for the diagnosis of neurotransmitters and pterin defects and glucose and folate transport deficiencies across blood brain barrier]
[Article in Spanish]
Ormazabal A, García Cazorla A, Pérez Dueñas B, Pineda M, Ruiz A, López Laso E, García Silva M, Carilho I, Barbot C, Cormand B, Ribases M, Moller L, Fernández Alvarez E, Campistol J, Artuch R.
Hospital Sant Joan de Déu, Esplugues, Barcelona, España.
Abstract
BACKGROUND AND OBJECTIVE: In the last few years, it has been described inborn errors of neurotransmitter and pterin metabolism and defects in folate and glucose transport across blood brain barrier. All these defects are classified as rare diseases and needs cerebrospinal fluid (CSF) sample analysis for diagnosis. Our aim was to evaluate the results of the application of a CSF analysis protocol in a pediatric population from Spain and Portugal presenting with neurological disorders of unknown origin.
PATIENTS AND METHOD: We studied CSF samples from and 283 patients with neurological disorders of unknown origin and 127 controls. Neurotransmitters were analysed by HPLC with electrochemical detection, and pterins and 5-methyltetrahydrofolate were determined by HPLC with fluorescence detection.
RESULTS: We diagnosed 3 patients with tyrosine hidroxylase deficiency, 2 with dopa responsive dystonia, 14 with GTP-ciclohydrolase deficiency, 2 with glucose transport deficiency and 43 with cerebral folate deficiency.
CONCLUSIONS: This study allowed us to diagnose new patients, and more importantly, the establishment in all of them of a pharmacological or nutritional treatment. The most frequent defect found was CSF 5-methyltetrahydrofolate deficiency, which was present in different groups of patients.
PMID: 16827996 [PubMed - indexed for MEDLINE
Synthetic Conjugates of Ursodeoxycholic Acid Inhibit Cystogenesis in Experimental Models of Polycystic Liver Disease
Altres ajuts: Suported by IKERBASQUE, Basque foundation for Science (M.J. Perugorria and J.M. Banales), Spain; "Junta de Castilla y Leon" (J.J.G. Marin: SA06P17); "Diputación Foral Gipuzkoa" (J.M. Banales: DFG15/010, DFG16/004; M.J. Perugorria: DFG18/114, DFG19/081), BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD to J.M. Banales), Department of Health of the Basque Country (J.M. Banales: 2017111010; M.J. Perugorria: 2019111024), and Euskadi RIS3 (J.M. Banales: 2016222001, 2017222014, and 2018222029; 2019222054); La Caixa Scientific Foundation (J.M. Banales: HR17-00601); "Fundación Científica de la Asociación Española Contra el Cáncer" (AECC Scientific Foundation, to J.M. Banales and J.J.G. Marin); and "Centro Internacional sobre el Envejecimiento", Spain (J.J.G. Marin: OLD-HEPAMARKER, 0348-CIE-6-E). A. Santos-Laso by the Basque Government (PRE_2018_2_0195), and Pui Y. Lee-Law by the European Association for the Study of the Liver (EASL; Sheila Sherlock Award). Basque Government (F.P. Cossío: IT-324-07). I. Rivilla had a postdoctoral contract from the Donostia International Physics Center.Background and Aims: Polycystic liver diseases (PLDs) are genetic disorders characterized by progressive development of symptomatic biliary cysts. Current surgical and pharmacological approaches are ineffective, and liver transplantation represents the only curative option. Ursodeoxycholic acid (UDCA) and histone deacetylase 6 inhibitors (HDAC6is) have arisen as promising therapeutic strategies, but with partial benefits. Approach and Results: Here, we tested an approach based on the design, synthesis, and validation of a family of UDCA synthetic conjugates with selective HDAC6i capacity (UDCA-HDAC6i). Four UDCA-HDAC6i conjugates presented selective HDAC6i activity, UDCA-HDAC6i #1 being the most promising candidate. UDCA orientation within the UDCA-HDAC6i structure was determinant for HDAC6i activity and selectivity. Treatment of polycystic rats with UDCA-HDAC6i #1 reduced their hepatomegaly and cystogenesis, increased UDCA concentration, and inhibited HDAC6 activity in liver. In cystic cholangiocytes UDCA-HDAC6i #1 restored primary cilium length and exhibited potent antiproliferative activity. UDCA-HDAC6i #1 was actively transported into cells through BA and organic cation transporters. Conclusions: These UDCA-HDAC6i conjugates open a therapeutic avenue for PLDs
A Single Nucleotide Polymorphism in the RASGRF2 Gene Is Associated with Alcoholic Liver Cirrhosis in Men
Background
Genetic polymorphisms in the RAS gene family are associated with different diseases, which may include alcohol-related disorders. Previous studies showed an association of the allelic variant rs26907 in RASGRF2 gene with higher alcohol intake. Additionally, the rs61764370 polymorphism in the KRAS gene is located in a binding site for the let-7 micro-RNA family, which is potentially involved in alcohol-induced inflammation. Therefore, this study was designed to explore the association between these two polymorphisms and susceptibility to alcoholism or alcoholic liver disease (ALD).
Methods
We enrolled 301 male alcoholic patients and 156 healthy male volunteers in this study. Polymorphisms were genotyped by using TaqMan® PCR assays for allelic discrimination. Allelic and genotypic frequencies were compared between the two groups. Logistic regression analysis was performed to analyze the inheritance model.
Results
The A allele of the RASGRF2 polymorphism (rs26907) was significantly more prevalent among alcoholic patients with cirrhosis (23.2%) compared to alcoholic patients without ALD (14.2%). This difference remained significant in the group of patients with alcohol dependence (28.8% vs. 14.3%) but not in those with alcohol abuse (15.1% vs. 14.4%). Multivariable logistic regression analysis showed that the A allele of this polymorphism (AA or GA genotype) was associated with alcoholic cirrhosis both in the total group of alcoholics (odds ratio [OR]: 2.33, 95% confidence interval [CI]: 1.32–4.11; P = 0.002) and in the group of patients with alcohol dependence (OR: 3.1, 95% CI: 1.50–6.20; P = 0.001). Allelic distributions of the KRAS polymorphism (rs61764370) did not differ between the groups.
Conclusions
To our knowledge, this genetic association study represents the first to show an association of the RASGRF2 G>A (rs26907) polymorphism with ALD in men, particularly in the subgroup of patients with AD. The findings suggest the potential relevance of the RAS gene family in alcoholism and ALD
Food loss and waste metrics: a proposed nutritional cost footprint linking linear programming and life cycle assessment
Purpose: The main purpose of this article is to assess the nutritional and economic efficiency of food loss and waste (FLW) along the supply of 13 food categories included in the Spanish food basket by means of the definition of a new method which combines two indexes.
Methods: The nutrient-rich foods index and the economic food loss and waste (EFLW) index were combined by means of linear programming to obtain the nutritional cost footprint (NCF) indicator under a life cycle perspective. The functional unit used was the daily supply of food for a Spanish citizen in year 2015.
Results and discussion: Results showed that vegetables and cereals were the food categories most affected by the inefficiencies in the food supply chain under a nutritional perspective, being agricultural production and household consumption the main stages in which the nutritional content of food is lost or wasted. Moreover, according to the NCF index, vegetables represented 27% of total nutritional-economic wastage throughout the entire Spanish agri-food chain. They are followed by fruits, which add up to 19%. Hence, specific food waste management strategies should be established for these specific products and supply stages. Finally, the sensitivity analysis performed highlighted that results were mostly independent from the importance attributed to either nutritional or economic variables.
Conclusions: The methodology described in this study proposes an indicator quantifying the nutritional-economic cost of different food categories in the Spanish food basket. This NCF indicator makes it possible to define reduction strategies to promote the use of food waste fractions for waste-to-energy valorization approaches or the extraction of different types of pharmacological, chemical, or cosmetic compounds.The authors are grateful for the funding of the Spanish Ministry of Economy and Competitiveness through the Ceres-Procom: Food production and consumption strategies for climate change mitigation (CTM2016-76176-C2-1-R) (AEI/FEDER, UE)
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