Characterization of Thin p-on-p Radiation Detectors with Active Edges

Active edge p-on-p silicon pixel detectors with thickness of 100 $\mu$m were fabricated on 150 mm Float zone silicon wafers at VTT. By combining measured results and TCAD simulations, a detailed study of electric field distributions and charge collection performances as a function of applied voltage in a p-on-p detector was carried out. A comparison with the results of a more conventional active edge p-on-n pixel sensor is presented. The results from 3D spatial mapping show that at pixel-to-edge distances less than 100 $\mu$m the sensitive volume is extended to the physical edge of the detector when the applied voltage is above full depletion. The results from a spectroscopic measurement demonstrate a good functionality of the edge pixels. The interpixel isolation above full depletion and the breakdown voltage were found to be equal to the p-on-n sensor while lower charge collection was observed in the p-on-p pixel sensor below 80 V. Simulations indicated this to be partly a result of a more favourable weighting field in the p-on-n sensor and partly of lower hole lifetimes in the p-bulk.Comment: 23 pages, 16 figures, 1 tabl

Leveling Up Hydrogels:Hybrid Systems in Tissue Engineering

Hydrogels can mimic several features of the cell native microenvironment and have been widely used as synthetic extracellular matrices (ECMs) in tissue engineering and regenerative medicine (TERM). However, some applications have specifications that hydrogels cannot efficiently fulfill on their own. Incorporating reinforcing structures like fibrous scaffolds or particles into hydrogels, as hybrid systems, is a promising strategy to improve their functionality. We describe recent advances in the fabrication and application of these hybrid systems, where structural properties and stimuli responsiveness of hydrogels are enhanced while their ECM-like features are preserved. Furthermore, we discuss how these systems can contribute to the development of more complex tissue engineered structures in the rapidly evolving field of TERM

Orbital contribution to the magnetic properties of nanowires: Is the orbital polarization ansatz justified?

We show that considerable orbital magnetic moments and magneto-crystalline anisotropy energies are obtained for a Fe monatomic wire described in a tight-binding method with intra-atomic electronic interactions treated in a full Hartree Fock (HF) decoupling scheme. Even-though the use of the orbital polarization ansatz with simplified Hamiltonians leads to fairly good results when the spin magnetization is saturated this is not the case of unsaturated systems. We conclude that the full HF scheme is necessary to investigate low dimensional systems

Engineering modular half-antibody conjugated nanoparticles for targeting CD44v6-expressing cancer cells

Gastric cancer (GC) remains a major cause of death worldwide mainly because of the late detection in advanced stage. Recently, we proposed CD44v6 as a relevant marker for early detection of GC, opening new avenues for GC-targeted theranostics. Here, we designed a modular nanoscale system that selectively targets CD44v6-expressing GC cells by the site-oriented conjugation of a new-engineered CD44v6 half-antibody fragment to maleimide-modified polystyrene nanoparticles (PNPs) via an efficient bioorthogonal thiol-Michael addition click chemistry. PNPs with optimal particle size (200 nm) for crossing a developed biomimetic CD44v6-associated GC stromal model were further modified with a heterobifunctional maleimide crosslinker and click conjugated to the novel CD44v6 half-antibody fragment, obtained by chemical reduction of full antibody, without affecting its bioactivity. Collectively, our results confirmed the specific targeting ability of CD44v6-PNPs to CD44v6-expressing cells (1.65-fold higher than controls), highlighting the potential of CD44v6 half-antibody conjugated nanoparticles as promising and clinically relevant tools for the early diagnosis and therapy of GC. Additionally, the rational design of our nanoscale system may be explored for the development of several other nanotechnology-based disease-targeted approaches.This work was supported by Norte Portugal Regional Operational Programme (NORTE2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF) projects Norte-01-0145-FEDER-000012 and NORTE-07-0124-FEDER-000029, through COMPETE 2020-Operational Programme for Competitiveness and Internationalization (POCI) Portugal 2020 and Portuguese Foundation for Science and Technology (FCT) in the framework of the projects POCI-01-0145-FEDER-007274, POCI-01-0145-FEDER-016390, and PTDC/CTMNAN/120958/2010, B.N.L. doctoral grant (SFRH/BD/87400/2012) and postdoctoral grant (PTDC/MEC-GIN/29232/2017). R.F.P. was supported by Institute of Network Bioengineering for Healthy Aging (0245_IBEROS_1_E)

Cell-instructive pectin hydrogels crosslinked via thiol-norbornene photo-click chemistry for skin tissue engineering

Cell-instructive hydrogels are attractive for skin repair and regeneration, serving as interactive matrices to promote cell adhesion, cell-driven remodeling and de novo deposition of extracellular matrix compo nents. This paper describes the synthesis and photocrosslinking of cell-instructive pectin hydrogels using cell-degradable peptide crosslinkers and integrin-specific adhesive ligands. Protease-degradable hydro gels obtained by photoinitiated thiol-norbornene click chemistry are rapidly formed in the presence of dermal fibroblasts, exhibit tunable properties and are capable of modulating the behavior of embedded cells, including the cell spreading, hydrogel contraction and secretion of matrix metalloproteases. Keratinocytes seeded on top of fibroblast-loaded hydrogels are able to adhere and form a compact and dense layer of epidermis, mimicking the architecture of the native skin. Thiol-ene photocrosslinkable pec tin hydrogels support the in vitro formation of full-thickness skin and are thus a highly promising plat form for skin tissue engineering applications, including wound healing and in vitro testing modinfo:eu-repo/semantics/publishedVersio

The Use of Instantaneous Phase for Improving Saft Images

6 páginas, 3 figuras. Proceedings of the 2013 International Congress on Ultrasonics (ICU 2013). 2-5 may 2013, SingaporeIn the SAFT technique (Synthetic Aperture Focusing Technique) each element operates in pulse-echo mode, requiring only on e transmit/receive channel. The generated beam pattern can present grating lobes, even if the pitc h is half wavelength, which are related to image quality. By considering the instantaneous phase of the signals detected by each transducer, it is possible to estimate if the signal used in the delay-and-sum algorithm, for each combination of array element and image pixel, is due to a reflector or if it is noise, improving the contrast and reducing the grating lobes effects.The authors would like to thank the financial support from FAPESP (2010/02240-0, 2010/16400- 0), Capes and CNPq as well as the government of Spain (CICYT - DPI 2010 19376).Peer reviewe

A Fast Alternative to Soft Lithography for the Fabrication of Organ-on-a-Chip Elastomeric-Based Devices and Microactuators

Organ-on-a-chip technology promises to revolutionize how pre-clinical human trials are conducted. Engineering an in vitro environment that mimics the functionality and architecture of human physiology is essential toward building better platforms for drug development and personalized medicine. However, the complex nature of these devices requires specialized, time consuming, and expensive fabrication methodologies. Alternatives that reduce design-to-prototype time are needed, in order to fulfill the potential of these devices. Here, a streamlined approach is proposed for the fabrication of organ-on-a-chip devices with incorporated microactuators, by using an adaptation of xurography. This method can generate multilayered, membrane-integrated biochips in a matter of hours, using low-cost benchtop equipment. These devices are capable of withstanding considerable pressure without delamination. Furthermore, this method is suitable for the integration of flexible membranes, required for organ-on-a-chip applications, such as mechanical actuation or the establishment of biological barrier function. The devices are compatible with cell culture applications and present no cytotoxic effects or observable alterations on cellular homeostasis. This fabrication method can rapidly generate organ-on-a-chip prototypes for a fraction of cost and time, in comparison to conventional soft lithography, constituting an interesting alternative to the current fabrication methods.C.O. and P.L.G. contributed equally to this work as co‐senior authors. This work was supported by Fundação para a Ciência e Tecnologia (FCT) and Doctoral Programme on Cellular and Molecular Biotechnology Applied to Health Sciences (BiotechHealth Programme; ref. PD/00016/2012), by Programa Operacional Potencial Humano (POPH), and SkinChip project (PTDC/BBB‐BIO/1889/2014). The work has been also financed by: 1) Fundo Europeu de Desenvolvimento (FEDER) Regional funds through the COMPETE 2020 – Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI‐01‐0145‐FEDER‐007274), 3DChroMe (PTDC/BTM‐TEC/30164/2017); Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) for projects NORTE‐01‐0145‐FEDER‐000029 and DOCnet (NORTE‐01‐0145‐FEDER‐000003). D.A.F. acknowledges FCT for his support through a FCT/BiotechHealth PhD Programme grant, ref. PD/BD/105976/2014. J.P.C. acknowledges funding from the European Structural and Investment funds through the Compete Programme (Grant #: LISBOA‐01‐0145‐FEDER‐016405) and from National funds through FCT (SAICTPAC/0019/2015) via the research project POINT4PAC, and FCT funding through INESC MN (Unidade ID 5367). The authors would also like to thank: Jorge Ferreira (Chromosome Instability Group, i3S/IBMC) for granting access to the plasma cleaner equipment and for the insightful scientific support; i3S Scientific Platform (Biointerfaces and Nanotechnology core facility, i3S/INEB), member of the national infrastructure PPBI – Portuguese Platform of Bioimaging (PPBI‐POCI‐01‐0145‐FEDER‐022122), in particular Maria Lázaro for support and access to the SP5 confocal microscope; Aureliana Sousa (Biofabrication Group at i3S/INEB) for scientific support and discussion; Dina Leitão (Centro Hospitalar e Universitário São João) for providing access to the normal gastric mucosa specimens; Celso Reis for kindly providing the antibody against Mucin‐1. C.O. and P.L.G. contributed equally to this work as co-senior authors. This work was supported by Funda??o para a Ci?ncia e Tecnologia (FCT) and Doctoral Programme on Cellular and Molecular Biotechnology Applied to?Health Sciences (BiotechHealth Programme; ref.?PD/00016/2012),?by Programa Operacional Potencial Humano (POPH), and SkinChip project (PTDC/BBB-BIO/1889/2014). The work has been also financed by: 1) Fundo Europeu de Desenvolvimento (FEDER) Regional funds through the COMPETE 2020 ? Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT/Minist?rio da Ci?ncia, Tecnologia e Inova??o in the framework of the projects ?Institute for Research and Innovation in Health Sciences? (POCI-01-0145-FEDER-007274), 3DChroMe (PTDC/BTM-TEC/30164/2017); Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) for projects NORTE-01-0145-FEDER-000029 and DOCnet (NORTE-01-0145-FEDER-000003). D.A.F. acknowledges FCT for his support through a FCT/BiotechHealth PhD Programme grant, ref. PD/BD/105976/2014. J.P.C. acknowledges funding from the European Structural and Investment funds through the Compete Programme (Grant #: LISBOA-01-0145-FEDER-016405) and from National funds through FCT (SAICTPAC/0019/2015) via the research project POINT4PAC, and FCT funding through INESC MN (Unidade ID 5367). The authors would also like to thank: Jorge Ferreira (Chromosome Instability Group, i3S/IBMC) for granting access to the plasma cleaner equipment and for the insightful scientific support; i3S Scientific Platform (Biointerfaces and Nanotechnology core facility, i3S/INEB), member of the national infrastructure PPBI ? Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122), in particular Maria L?zaro for support and access to the SP5 confocal microscope; Aureliana Sousa (Biofabrication Group at i3S/INEB) for scientific support and discussion; Dina Leit?o (Centro Hospitalar e Universit?rio S?o Jo?o) for providing access to the normal gastric mucosa specimens; Celso Reis for kindly providing the antibody against Mucin-1

Patients' recollections of experiences in the intensive care unit may affect their quality of life

INTRODUCTION: We wished to obtain the experiences felt by patients during their ICU stay using an original questionnaire and to correlate the memories of those experiences with health-related quality of life (HR-QOL). METHODS: We conducted a prospective study in 10 Portuguese intensive care units (ICUs). Six months after ICU discharge, an original questionnaire on experiences of patients during their ICU stay, the recollection questionnaire, was delivered. HR-QOL was evaluated simultaneously, with the EQ-5D questionnaire. Between 1 September 2002 and 31 March 2003 1433 adult patients were admitted. ICU and hospital mortalities were 21% and 28%, respectively. Six months after ICU discharge, 464 patients completed the recollection questionnaire. RESULTS: Thirty-eight percent of the patients stated they did not remember any moment of their ICU stay. The ICU environment was described as friendly and calm by 93% of the patients. Sleep was described as being good and enough by 73%. The experiences reported as being more stressful were tracheal tube aspiration (81%), nose tube (75%), family worries (71%) and pain (64%). Of respondents, 51% experienced dreams and nightmares during their ICU stay; of these, 14% stated that those dreams and nightmares disturb their present daily life and they exhibit a worse HR-QOL. Forty-one percent of patients reported current sleep disturbances, 38% difficulties in concentrating in current daily activities and 36% difficulties in remembering recent events. More than half of the patients reported more fatigue than before the ICU stay. Multiple and linear regression analysis showed that older age, longer ICU stay, higher Simplified Acute Physiology Score II, non-scheduled surgery and multiple trauma diagnostic categories, present sleep disturbances, daily disturbances by dreams and nightmares, difficulties in concentrating and difficulties in remembering recent events were independent predictors of worse HR-QOL. Multicollinearity analysis showed that, with the exception of the correlation between admission diagnostic categories and length of ICU stay (0.47), all other correlations between the independent variables and coefficient estimates included in the regression models were weak (below 0.30). CONCLUSION: This study suggests that neuropsychological consequences of critical illness, in particular the recollection of ICU experiences, may influence subsequent HR-QOL