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Understanding the link between post-acquisition resource reconfiguration and technology out-licensing.
No full textWe develop a novel framework to explain how the unique properties of out-licensing enable R&D reconfiguration in the context of technology acquisitions. Out-licensing is an attractive R&D strategy following acquisitions as it expands opportunities for resource reconfiguration to outside the organization by using external partners while at the same time allowing firms to continue to benefit from the technology, both financially and strategically. We also propose that the positive relationship between technology acquisitions and out-licensing is weaker when firms cannot determine the full value potential of their R&D due to uncertainty or when they have high availability of short-term financial slack resources. Using a sample of bio-pharmaceutical firms, the result of a 2SLS fixed-effect regression that accounts for the potential endogeneity of technology acquisitions provides support for our theoretical framework
A microstructure-based constitutive model for pearlite.
No full textFully pearlitic eutectoid steels have an excellent compromise of mechanical
strength and ductility and are widely used for rails, prestressing tendons and high-
strength wires. These excellent mechanical properties are a consequence of their
particular nanocomposite structure combining thin cementite lamellae (~12% volume
fraction) with ferritic lamellae. This complex substructure entails a complex
microstructural and property evolution with applied strain that is difficult to model.
In this work, a microstructure-based constitutive model for pearlite accounting
for both the elastoplastic behaviour and the damage evolution is presented. The
original formulation, valid for mesoscopic scales, considers the behaviour of ferrite
and cementite separately, assuming that strengthening occurs through the
mechanisms acting in ferrite. For its application in macro-scale systems such as wire
drawing, a multi-colony homogenization strategy has been applied. For damage, a
Continuum Damage Mechanics approach adapted to the features of pearlite has been
adopted with the coupling of damage to the mechanical response. The model has
been implemented for use in finite element simulations and has been calibrated using
experimental data of tensile and torsion tests. Subsequently, the model has been
validated, confirming its predictive capabilities across various aspects, including the
mechanical response under different stress states, the build-up of internal stresses and
the evolution of the microstructure with deformation.Los aceros eutectoides totalmente perlíticos presentan un excelente
compromiso de resistencia mecánica y ductilidad, y se utilizan ampliamente para raíles,
cables de pretensado y alambres de alta resistencia. Estas excelentes propiedades
mecánicas son consecuencia de su particular estructura nanocompuesta que combina
finas láminas de cementita (~12% de fracción volumétrica) con láminas ferríticas.
Esta compleja subestructura conlleva una compleja evolución microestructural y de
propiedades con la deformación aplicada que resulta difícil de modelizar.
En este trabajo, se presenta un modelo constitutivo basado en la
microestructura de la perlita que considera tanto el comportamiento elastoplástico
como la evolución del daño. La formulación original, válida para escalas
mesoscópicas, contempla el comportamiento de la ferrita y la cementita por separado,
asumiendo que el endurecimiento se produce a través de los mecanismos que actúan
en la ferrita. Para su aplicación en sistemas macroscópicos, como el trefilado de
alambres, se ha aplicado una estrategia de homogeneización multi-colonia. En cuanto
al daño, se ha adoptado un enfoque de la Mecánica del Daño Continuo adaptado a
las características de la perlita, con el acoplamiento del daño a la respuesta mecánica.
El modelo se ha implementado para su uso en simulaciones de elementos finitos y se
ha sometido a un proceso de calibración utilizando datos experimentales de ensayos
de tracción y torsión. Posteriormente, se ha validado el modelo, confirmando su
capacidad predictiva en varios aspectos, incluyendo la respuesta mecánica bajo
diferentes estados de tensión, la acumulación de tensiones internas y la evolución de
la microestructura con la deformación
Mutagenicity and genotoxicity assessment of the emerging mycotoxin Versicolorin A, an Aflatoxin B1 precursor
No full textAflatoxin B1 (AFB1) is the most potent natural carcinogen among mycotoxins. Versicolorin A (VerA) is a pre-
cursor of AFB1 biosynthesis and is structurally related to the latter. Although VerA has already been identified as a genotoxin, data on the toxicity of VerA are still scarce, especially at low concentrations. The SOS/umu and
miniaturised version of the Ames test in Salmonella Typhimurium strains used in the present study shows that
VerA induces point mutations. This effect, like AFB1, depends primarily on metabolic activation of VerA. VerA
also induced chromosomal damage in metabolically competent intestinal cells (IPEC-1) detected by the micro-
nucleus assay. Furthermore, results from the standard and enzyme-modified comet assay confirmed the VerA-
mediated DNA damage, and we observed that DNA repair pathways were activated upon exposure to VerA, as
indicated by the phosphorylation and/or relocation of relevant DNA-repair biomarkers (γH2AX and 53BP1/
FANCD2, respectively). In conclusion, VerA induces DNA damage without affecting cell viability at concentra-
tions as low as 0.03 μM, highlighting the danger associated with VerA exposure and calling for more research on the carcinogenicity of this emerging food contaminant
Magnetic resonance volumetric quantification of vestibular endolymphatic hydrops in patients with unilateral definite meniere’s disease using 3D inversion recovery with real reconstruction (3D-REAL-IR) sequence
No full textBackground: The 3D-REAL-IR MRI sequence allows for an in vivo visualization of endolymphatic hydrops. Qualitative assessment methods of the severity of vestibular and cochlear
hydrops are the most commonly used. Methods: A quantitative volumetric measurement of vestibular EH in patients with definite unilateral Ménière’s disease using the 3D-REAL-IR sequence and the
calculation of the endolymphatic ratio (ELR) was intended. Results: Volumetric calculations of the
vestibules, vestibular endolymph and vestibular ELR are performed in 96 patients with unilateral
Ménière’s disease and correlated with classic qualitative grading scales. Conclusions: Quantitative volumetric measurement of vestibular hydrops using the 3D-REAL-IR sequence is feasible
and reproducible in daily clinical practice. Vestibular ELR values exceeding 60% defined radiologically significant vestibular hydrops, while values below 30% defined radiologically non-significant
vestibular hydrops
Tratamiento preventivo de la bacteriemia asociada a catéter venoso central tunelizado en pacientes en hemodiálisis
No full textEn este estudio sobre la monitorización de pacientes en hemodiálisis con catéteres venosos centrales se concluye que el cultivo cuantitativo de sangre intracatéter es efectivo para detectar colonización crítica por estafilococos coagulas negativa pudiendo prevenir la progresión a bacteriemia relacionada con el catéter. Se encontró que el tratamiento anticipado con sellado antibiótico, particularmente con combinaciones de heparina y daptomicina o teicoplanina, redujo significativamente el riesgo de recolonización y bacteriemia relacionada con el catéter. Además, no se observaron aumentos significativos en eventos adversos o disfunciones del catéter en pacientes tratados con sellado antibiótico en comparación con los tratados solo con heparina
Metabolic dysfunction–associated fatty liver disease (MAFLD): an update of the recent advances in pharmacological treatment
No full textMetabolic dysfunction-associated fatty liver disease (MAFLD) is nowadays considered the liver manifestation of metabolic syndrome. Its prevalence is increasing worldwide in parallel to the epidemic of diabetes and obesity. MAFLD includes a wide spectrum of liver injury including simple steatosis and non-alcoholic steatohepatitis (NASH) that may lead to serious complications such as liver cirrhosis and liver cancer. The complexity of its pathophysiology and the intricate mechanisms underlying disease progression explains the huge variety of molecules targeting diverse biological mechanisms that have been tested in preclinical and clinical settings in the last two decades. Thanks to the large number of clinical trials of the last few years, most of them still ongoing, the pharmacotherapy scenario of MAFLD is rapidly evolving. The three major components of MAFLD, steatosis, inflammation, and fibrosis seem to be safely targeted with different agents at least in a large proportion of patients. Likely, in the next few years more than one drug will be approved for the treatment of MAFLD at different disease stages. The aim of this review is to synthesize the characteristics and the results of the most advanced clinical trials for the treatment of NASH to evaluate the recent advances of pharmacotherapy in this disease
The effects of COVID-19 lockdown on the sleep quality of children
No full textIntroduction: The COVID-19 lockdown has caused important changes in children's routines, especially in terms of nutrition, physical activity, screen time, social activity, and school time. Regarding these changes, recent studies show that the COVID-19 lockdown is associated with higher levels of anxiety and depression in children. The objective of this study was to assess changes in sleep quality in Spanish children during the lockdown decreed by the Spanish government between March and June 2020.
Methodology: We compared the BEAR (bedtime, excessive daytime sleepiness, awakening during the night, and regularity and duration of sleep) scores of 478 participants (median age = 7.5 years; 48% girls) in the SENDO project during the periods before, during, and after lockdown. The questionnaires were filled out by one of the parents. We used hierarchical models with two levels of clustering to account for the intra-cluster correlation between siblings. The interaction of time with a set of a priori selected variables was assessed by introducing the interaction term into the model and calculating the likelihood ratio test.
Results: The mean scores in the BEAR questionnaire referred to the periods before, during, and after lockdown were 0.52 (sd 1.25), 1.43 (sd 1.99), and 1.07 (sd 1.55), respectively. These findings indicate a deterioration in sleep quality during the period of confinement. Parental level of education was found to be an effect modifier (p for interaction = 0.004). Children whose parents had higher education (university graduates or higher) showed a smaller worsening than those without.
Conclusion: Our study shows that the COVID-19 lockdown was associated with a significant worsening of sleep quality. Moreover, although the end of the lockdown brought about a slight improvement, mean scores on the BEAR scale remained significantly higher than before the lockdown, suggesting that the consequences for sleep quality could persist over time. This worsening was higher in children whose parents had lower educational degrees. Helping children maintain healthy sleeping habits despite the circumstances and providing early psychological support when needed is important to prevent negative psycho-physical symptoms due to lockdown that could persist over the years
Bariatric surgery is associated with alcohol-related liver disease and psychiatric disorders associated with AUD
No full textBackground/Aims Bariatric surgery can increase the risk of addictive disorders and nutritional deficiencies. The aim of this study was to evaluate the association between bariatric surgery and alcohol use disorder (AUD), alcohol-related liver disease (ALD), and psychiatric disorders associated with AUD. The impact of vitamin D deficiency in these associations was also investigated.Methods A cross-sectional study was performed using the National Inpatient Sample database and its ICD-9 codes information. Diagnostic and comorbidity data from hospital discharges were obtained from patients with bariatric surgery and other abdominal surgeries between 2005 and 2015. The two groups were then compared for alcohol-related outcomes after propensity-score matching.Results The final study cohort included 537,757 patients with bariatric surgery and 537,757 with other abdominal surgeries. The bariatric surgery group had an increased risk of AUD [odds ratio (OR): 1.90; 95% CI: 1.85-1.95], ALD [OR: 1.29; 95% CI: 1.22-1.37], cirrhosis [OR, 1.39; 95% CI: 1.37-1.42], and psychiatric disorders associated with AUD [OR, 3.59; 95% CI: 3.37-3.84]. Vitamin D deficiency did not impact in the association between bariatric surgery and AUD, ALD, or psychiatric disorders associated with AUD.Conclusions Bariatric surgery is associated with an increased prevalence of AUD, ALD, and psychiatric disorders associated with AUD. These associations appear to be independent from vitamin D deficiency
Study of the processing conditions for stainless steel additive manufacturing using femtosecond laser
Get PDFThe use of ultrashort-pulsed (USP) lasers in Additive Manufacturing (AM) enables the processing of different materials and has the potential to reduce the sizes and shapes manufactured with this technology. This work confirms that USP lasers are a viable alternative for Laser Powder Bed Fusion (LPBF) when higher precision is required to manufacture certain critical parts. Promising results were obtained using tailored and own-produced stainless steel powder particles, manufacturing consistent square layers with a series of optimized processing parameters. The critical role of processing parameters is confirmed when using this type of lasers, as a slight deviation of any of them results in an absence of melting. For the first time, melting has been achieved at low pulse repetition (500 kHz) and using low average laser power values (0.5-1 W), by generating heat accumulation at reduced scanning speeds. This opens up the possibility of further reducing the minimum size of parts when using USP lasers for AM