A handheld high-sensitivity micro-NMR CMOS platform with B-field stabilization for multi-type biological/chemical assays

We report a micro-nuclear magnetic resonance (NMR) system compatible with multi-type biological/chemical lab-on-a-chip assays. Unified in a handheld scale (dimension: 14 x 6 x 11 cm³, weight: 1.4 kg), the system is capable to detect<100 pM of Enterococcus faecalis derived DNA from a 2.5 μL sample. The key components are a portable magnet (0.46 T, 1.25 kg) for nucleus magnetization, a system PCB for I/O interface, an FPGA for system control, a current driver for trimming the magnetic (B) field, and a silicon chip fabricated in 0.18 μm CMOS. The latter, integrated with a current-mode vertical Hall sensor and a low-noise readout circuit, facilitates closed-loop B-field stabilization (2 mT → 0.15 mT), which otherwise fluctuates with temperature or sample displacement. Together with a dynamic-B-field transceiver with a planar coil for micro-NMR assay and thermal control, the system demonstrates: 1) selective biological target pinpointing; 2) protein state analysis; and 3) solvent-polymer dynamics, suitable for healthcare, food and colloidal applications, respectively. Compared to a commercial NMR-assay product (Bruker mq-20), this platform greatly reduces the sample consumption (120x), hardware volume (175x), and weight (96x)

Endometrial injury in women undergoing assisted reproductive techniques

ACKNOWLEDGEMENTS We would like to express our appreciation to Dra Abha Maheshwari for her important authorial contribution to the previous version of this review. We also acknowledge the important help provided by the Cochrane Menstrual Disorders and Subfertility Group team, specially by Marian Showell, Trials Search Co-ordinator; by Helen Nagels, Managing Editor; and by Prof. Cindy Farquhar, Co-ordinating Editor. Finally, we would like to express our gratitude to the following investigators, who provided essential information for the preparation of this review: TK Aleyamma, Erin F Wolff, Lukasz Polanski, Nava Dekel, Neeta Singh, Suleyman Guven and Tracy YeungPeer reviewedPublisher PD

TOFtracker: combination of time-of-flight and high-accuracy bidimensional tracking in a single gaseous detector

A 5-gap timing RPC equipped with patterned electrodes coupled to both charge-sensitive and timing circuits yields a time accuracy of 77 ps along with a position accuracy of 38 μm. These results were obtained by calculating the straight-line fit residuals to the positions provided by a 3-layer telescope made out of identical detectors, detecting almost perpendicular cosmic-ray muons. The device may be useful for particle identification by time-of-flight, where simultaneous measurements of trajectory and time are necessary

Pre-school science education in Portugal: teacher education and innovative practices

Assuming science education in the early years as the stepping stone for the development of scientific and technological literacy, a teacher training program was developed with six kindergarten teachers in Portugal. Its aim was to promote the (re)construction of their subject content and pedagogical knowledge leading to innovative practices, based on the characterization of their profile, shortcomings and practices. Learning through practice was considered the most effective means to promote change in kindergarten teachers’ curricular approaches to science, hence the development of practical activities focusing on children’s understanding and requiring their scientific knowledge and enquiry processes. These include a teacher’s guide (presenting its objectives, concepts and teaching, learning and assessment strategies), a theoretical framework (presenting the concepts, known misconceptions and research references) and also the necessary didactic resources. The paper details the results of the developed teacher training program as well of the validation process of the designed teaching strategies

Novos desafios societais no ensino das ciências e tecnologia: programa completo e resumos do V Seminário Ibero-Americano CTS e IX Seminário CTS

O papel e a importância da Ciência e da Tecnologia (C&T) nas sociedades modernas atuais é, especialmente desde o último quartel do Século XX, inquestionável, em particular para a coesão e desenvolvimento económico e social. Os argumentos teóricos e suas implicações práticas têm sido usados por muitos para reforçar a relevância da educação, nomeadamente a educação científica, para esse desenvolvimento. No entanto, o modo como tal pode ser atingido não é isento de controvérsias, pois continuam a proliferar propostas diferentes de organização curricular, de finalidades e objetivos da Educação em C&T, de estratégias, atividades e recursos a utilizar, de modelos de formação de professores e de avaliação de competências (Martins, Paixão e Vieira, em atas do III Seminário Ibérico CTS, 2004). Todavia, espera-se e exige-se que a educação permita a todos alcançar a mobilização de competências que sustentem tomada de posição e ou decisão em questões que compreendam relações entre a Ciência, a Tecnologia e a Sociedade. Estas interrelações têm sido o cerne da educação Ciência-Tecnologia-Sociedade (CTS). (...)publishe

A formação contínua de professores dos primeiros anos de escolaridade em Portugal: impactes no ensino experimental das ciências

A Ciência e a Tecnologia, especialmente nos últimos 200 anos, têm-se afirmado como o mais sólido empreendimento das sociedades modernas. Diversas decisões, nas suas diversas esferas, são baseadas e fundamentadas nos desenvolvimentos e produtos científicos e tecnológicos que têm contribuído visivelmente para a melhoria da qualidade de vida de muitos seres humanos. A escola tem procurado incorporar nos seus currículos vários desses desenvolvimentos e competências. Neste quadro, tem vindo a ganhar relevância a premência de uma educação em Ciências para todos, desde os primeiros anos de escolaridade, promotora de literacia científica assente em ideias que promovam um desenvolvimento pessoal e social dos alunos que lhes permitam participar responsável e criticamente na sociedade (Martins et al., 2006; Martins e Paixão, 2011; Osborne e Dillon, 2008; Vieira, Tenreiro-Vieira e Martins, 2011; Vieira e Tenreiro-Vieira, 2016). Todos os cidadãos devem dispor de conhecimentos em (bem como sobre e pelas) Ciências e Tecnologia, de modo a formar-se uma sociedade crítica, reflexiva e atenta a situações e dilemas que surgem das relações entre a Ciência e a Tecnologia e as atividades sociais, económicas e políticas (Martins e Paixão, 2011).publishe

New designsns of solar collectors for heterogeneous TiO2 photocatalytic processes

Solar hardware design for photocatalytic processes includes aspects of optics, geometry and reactor materials. Compound parabolic collectors (CPCs) have widely been used to promote heterogeneous and homogeneous photocatalytic reactions. In this work, different reflective surface (RS) materials (anodized aluminum with [MS] and without [R85] protective coating, soiled aluminum [R85s] and stainless steel [SS]) and geometries (flat [F], single piece-double parabola [SP] and two pieces-double parabola [DP]) were tested aiming the degradation of a recalcitrant organic compound, gatifloxacin (GAT), by using a heterogeneous TiO2 photocatalytic system. Firstly, the photonic flux entering the system was measured by 2-nitrobenzaldehyde actinometry, considering the different RSs. After that, the catalyst (TiO2-P25) was immobilized in the surface of a static mixer and axially inserted in the tubular borosilicate photoreactor. Finally, the efficiency of the heterogeneous photocatalytic system was evaluated for GAT removal from aqueous solution using the best photoreactor configuration.info:eu-repo/semantics/publishedVersio