Droplet impact onto moving liquids

From rain drops landing on the ocean to inkjet printing, the impact of droplets onto moving liquid surfaces is a ubiquitous process in nature and in industry. A rich range of phenomena can arise. The behaviour depends on the inertia, the properties of the drops and the relative speeds in the impact zone. While the result ranges from tranquil coalescence to violent splashing, intermediate regimes also occur, including partial and complete bouncing and even 'surfing' of the droplet. These regimes are determined by the ratio of the drop and surface velocities and the liquid properties. A regime diagram can be constructed in which distinct dynamical regimes are clearly identified.This project was supported by the EPSRC (grant EP/H018913/1), the John Fell Oxford University Press Research Fund, and the Royal Society (through a University Research Fellowship and a Research Grant)

Manufacturing process of a brain aneurysm biomodel in PDMS using rapid prototyping

Cerebral aneurysm is an abnormal dilatation of the blood vessel into a saccular form. They can originate in congenital defects, weakening of the arterial wall with increasing age, atherosclerotic changes, trauma and infectious emboli. The in vivo experiments are an effective way of investigating the appearance, validating new practices and techniques, but beyond ethical issues, these types of experiments are expensive and have low reproducibility. Thus, to better understand the pathophysiological and geometric aspects of an aneurysm, it is important to fabricate in vitro models capable of improving existing endovascular treatments, developing and validating theoretical and computational models. Another difficulty is in the preoperative period of the non-ruptured cerebral aneurysm, known for the success of the skilled acts because there is an anatomical structure of the aneurysm as its current position. Although there are technologies that facilitate three-dimensional video visualization in the case of aneurysms with complex geometries the operative planning is still complicated, so the development of the real three-dimensional physical model becomes advantageous. In this work, the entire process of manufacturing an aneurysm biomodel using polydimethylsiloxane (PDMS) is disassembled by rapid prototyping technology. The manufactured biomodels are able to perform different hemodynamic studies, validate theoretical data, numerical simulations and assist in the preoperative planning.info:eu-repo/semantics/publishedVersio

Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2•−, generate Al superoxides [Al(O2•)](H2O5)]+ 2. Semireduced AlO2• radicals deplete mitochondrial Fe and promote generation of H2O2, O2 • − and OH•. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

Magnetic PDMS microparticles for biomedical and energy applications

Polydimethylsiloxane (PDMS) is one of the most widely used polymers in microfluidics. Furthermore, magnetic nanoparticles (MNPs), due their superior thermal properties, are also gaining a great interest among the industry and microfluidic scientific community. In this work, a technique based on a flow focusing principle was used to produce magnetic PDMS microparticles. A microvisualization system composed by digital video cameras and optical lenses was used to control and measure the size of the obtained microparticles. To the best of our knowledge, this is the first work that shows magnetic PDMS microparticles able to be used for both biomedical and energy applications.This work was supported by Fundação para a Ciência e a Tecnologia (FCT) under the strategic grants UID/EMS/04077/2019, UID/EEA/04436/2019 and UID/EMS/00532/2019. The authors are also grateful for the funding of FCT through the projects POCI-01-0145-FEDER-016861, POCI-01-0145-FEDER-028159, NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER-030171, funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER, and the PhD grant SFRH/BD/91192/2012. The authors also acknowledge to FCT for partially financing the research under the framework of the project UTAP-EXPL/CTE/0064/2017, financiado no âmbito do Projeto 5665 - Parcerias Internacionais de Ciência e Tecnologia, UT Austin Programme. Partial support from the Spanish Ministry of Science and Education (grant no. DPI2016-78887) and Junta de Extremadura (grants no. GR15014 and IB18005, partially financed by FEDER funds) are gratefully acknowledged too

Fast, flexible and low-cost multiphase blood analogue for biomedical and energy applications

During the last two decades, several kinds of particulate blood analogue fluids have been proposed, but none of those were able to mimic the multiphase effects of real blood. Hence, it is clear that it is crucial to develop a simple multiphase blood analogue to be used for in vitro experiments at both macro- and microscale level. To the best of our knowledge, the present work shows for the first time a straightforward and extremely stable blood analogue fluid able to mimic multiphase blood flow phenomena. The present work proposes a simple, low-cost and stable multiphase blood analogue with the ability to mimic microscale blood flow phenomena. The proposed analogue fluid is composed of Brij L4 surfactant micelles suspended in pure water and is extremely easy to be produced. To investigate the ability of this analogue to mimic microscale blood flow phenomena, flow visualizations were performed in a microchannel constriction. In vitro blood phenomena were compared with the measurements performed with the proposed analogue fluid. Additionally, rheological measurements of the multiphase blood analogue were acquired by means of a stress-controlled rheometer and compared with in vitro blood sample viscosity curves. Overall, the results indicate that it is possible to produce a stable particulate fluid with geometrical, mechanical and flow properties similar to in vitro blood. Hence, the proposed analogue has a great potential to be used in flow experiments from macro- to nanoscale levelsFundação para a Ciência e a Tecnologia (FCT) under the strategic grants UIDB/04077/2020, UIDB/04436/2020 and UIDB/00532/2020. The authors are also grateful for the funding of FCT through the projects NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER-030171 and POCI-01-0145-FEDER-016861 (PTDC/QEQ-FTT/4287/2014) funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER. The authors also acknowledge FCT for partially financing the research under the framework of the project UTAP-EXPL/CTE/0064/2017, financiado no âmbito do Projeto 5665—Parcerias Internacionais de Ciência e Tecnologia, UT Austin Programme. Partial support from the Spanish Ministry of Science and Education (grant no. DPI2016-78887) and Junta de Extremadura (grants no. GR15014 and IB18005, partially financed by FEDER funds) is gratefully acknowledged too

Increased inflammatory markers identified in the dorsolateral prefrontal cortex of individuals with schizophrenia

Upregulation of the immune response may be involved in the pathogenesis of schizophrenia with changes occurring in both peripheral blood and brain tissue. To date, microarray technology has provided a limited view of specific inflammatory transcripts in brain perhaps due to sensitivity issues. Here we used SOLiD Next Generation Sequencing to quantify neuroimmune mRNA expression levels in the dorsolateral prefrontal cortex of 20 individuals with schizophrenia and their matched controls. We detected 798 differentially regulated transcripts present in people with schizophrenia compared with controls. Ingenuity pathway analysis identified the inflammatory response as a key change. Using quantitative real-time PCR we confirmed the changes in candidate cytokines and immune modulators, including interleukin (IL)-6, IL-8, IL-1b and SERPINA3. The density of major histocompatibility complex-II-positive cells morphologically resembling microglia was significantly increased in schizophrenia and correlated with IL-1b expression. A group of individuals, most of whom had schizophrenia, were found to have increased inflammatory mRNA expression. In summary, we have demonstrated changes in an inflammatory response pathway that are present in 40% of people diagnosed with schizophrenia. This suggests that therapies aimed at immune system attenuation in schizophrenia may be of direct benefit in the brain

Urbanization and raptors : trends and research approaches

Urbanization presents a major global issue for the conservation and survival of many different species. With the increasing footprint of cities and intensification of our use of urban areas, wildlife faces extremely difficult challenges to live there. Understanding how species respond to urban processes and how to design urban landscapes that facilitate species’ presences are major emerging research and management priorities. Despite general negative responses to increasing urbanization, some animal taxa, both native and introduced, appear to benefit from urban environments by capitalizing on novel environments and abundant resources.1 Those that are common in urban systems display particular physical characteristics and ecological traits.2,3,4 They also frequently display a level of behavioral plasticity or tolerance, adjusting their behavior to interact with, and survive in, urban environments.5,6 Termed urban-adaptors,7 these species may exhibit altered spatial,8,9,10 foraging,11,12 and breeding behaviors,13 as detailed in chapter 2