Contrast agent-free sonoporation: The use of an ultrasonic standing wave microfluidic system for the delivery of pharmaceutical agents     

Carugo D  Ankrett DN  Glynne-Jones P  Capretto L  Boltryk RJ  Zhang X  Townsend PA  Hill M 《Biomicrofluidics》2011,5(4):44108-4410815

Sonoporation is a useful biophysical mechanism for facilitating the transmembrane delivery of therapeutic agents from the extracellular to the intracellular milieu. Conventionally, sonoporation is carried out in the presence of ultrasound contrast agents, which are known to greatly enhance transient poration of biological cell membranes. However, in vivo contrast agents have been observed to induce capillary rupture and haemorrhage due to endothelial cell damage and to greatly increase the potential for cell lysis in vitro. Here, we demonstrate sonoporation of cardiac myoblasts in the absence of contrast agent (CA-free sonoporation) using a low-cost ultrasound-microfluidic device. Within this device an ultrasonic standing wave was generated, allowing control over the position of the cells and the strength of the acoustic radiation forces. Real-time single-cell analysis and retrospective post-sonication analysis of insonated cardiac myoblasts showed that CA-free sonoporation induced transmembrane transfer of fluorescent probes (CMFDA and FITC-dextran) and that different mechanisms potentially contribute to membrane poration in the presence of an ultrasonic wave. Additionally, to the best of our knowledge, we have shown for the first time that sonoporation induces increased cell cytotoxicity as a consequence of CA-free ultrasound-facilitated uptake of pharmaceutical agents (doxorubicin, luteolin, and apigenin). The US-microfluidic device designed here provides an in vitro alternative to expensive and controversial in vivo models used for early stage drug discovery, and drug delivery programs and toxicity measurements.  相似文献   

The effects of teacher support,parental monitoring,motivation and self-efficacy on academic performance over time     

Affuso  Gaetana  Zannone  Anna  Esposito  Concetta  Pannone  Maddalena  Miranda  Maria Concetta  De Angelis  Grazia  Aquilar  Serena  Dragone  Mirella  Bacchini  Dario 《European Journal of Psychology of Education - EJPE》2023,38(1):1-23

European Journal of Psychology of Education - This study aimed to investigate the contribution of teacher support and parental monitoring to academic performance over three years, testing the...  相似文献   

Sliding mode optimal control for linear systems     

Michael Basin  Pablo Rodriguez-Ramirez  Antonella Ferrara  Dario Calderon-Alvarez 《Journal of The Franklin Institute》2012,349(4):1350-1363

This paper addresses the optimal control problem for a linear system with respect to a Bolza–Meyer criterion with a non-quadratic non-integral term. The optimal solution is obtained as a sliding mode control, whereas the conventional linear feedback control fails to provide a causal solution. Performance of the obtained optimal controller is verified in the illustrative example against the conventional LQ regulator that is optimal for the quadratic Bolza–Meyer criterion. The simulation results confirm an advantage in favor of the designed sliding mode control.  相似文献   

Self‐Concepts,Self‐Esteem,and Academic Achievement of Minority and Majority North American Elementary School Children          下载免费PDF全文

Dario Cvencek  Stephanie A. Fryberg  Rebecca Covarrubias  Andrew N. Meltzoff 《Child development》2018,89(4):1099-1109

Minority and majority elementary school students from a Native American reservation (N = 188; K–fifth grade; 5‐ to 10‐year‐olds) completed tests of academic self‐concepts and self‐esteem. School grades, attendance, and classroom behavior were collected. Both minority and majority students exhibited positive self‐esteem. Minority students demonstrated lower academic self‐concepts and lower achievement than majority students. Two age‐related patterns emerged. First, minority students had lower academic achievement than majority students, and this effect was stronger in older (Grades 3–5) than in younger (Grades K–2) students. Second, children's actual achievement was related to their academic self‐concepts for older students but more strongly linked to self‐esteem in younger students. The authors offer a developmental account connecting students’ developing self‐representations to their school achievement.  相似文献   

Puberty Predicts Approach But Not Avoidance on the Iowa Gambling Task in a Multinational Sample          下载免费PDF全文

Grace Icenogle  Laurence Steinberg  Thomas M. Olino  Elizabeth P. Shulman  Jason Chein  Liane P. Alampay  Suha M. Al‐Hassan  Hanan M. S. Takash  Dario Bacchini  Lei Chang  Nandita Chaudhary  Laura Di Giunta  Kenneth A. Dodge  Kostas A. Fanti  Jennifer E. Lansford  Patrick S. Malone  Paul Oburu  Concetta Pastorelli  Ann T. Skinner  Emma Sorbring  Sombat Tapanya  Liliana M. Uribe Tirado 《Child development》2017,88(5):1598-1614

According to the dual systems model of adolescent risk taking, sensation seeking and impulse control follow different developmental trajectories across adolescence and are governed by two different brain systems. The authors tested whether different underlying processes also drive age differences in reward approach and cost avoidance. Using a modified Iowa Gambling Task in a multinational, cross‐sectional sample of 3,234 adolescents (ages 9–17; M = 12.87, SD = 2.36), pubertal maturation, but not age, predicted reward approach, mediated through higher sensation seeking. In contrast, age, but not pubertal maturation, predicted increased cost avoidance, mediated through greater impulse control. These findings add to evidence that adolescent behavior is best understood as the product of two interacting, but independently developing, brain systems.  相似文献   

Splitting and projection: drawing on psychodynamics in educational psychology practice     

Dario W. Pellegrini 《Educational Psychology in Practice》2010,26(3):251-260

This paper reflects the author’s journey into an area of psychology which is not dominant in Educational Psychology discourse, namely psychodynamic psychology. Two psychodynamic mechanisms, namely splitting and projection are explained, and then the author describes and critiques how these mechanisms have proved useful in his practice. Two case studies are presented to illustrate how a reflective stance guided by psychodynamic concepts was fruitful in analysing and, sometimes, removing emotional obstacles in the author’s practice. Finally a hypothesis is formulated to explain the apparent lack of educational psychologists’ interest in psychodynamic psychology.  相似文献   

Integrating best evidence into patient care: a process facilitated by a seamless integration with informatics tools     

Nunzia B Giuse  Annette M Williams  Dario A Giuse 《Journal of the Medical Library Association》2010,98(3):220-222

The Vanderbilt University paper discusses how the Eskind Biomedical Library at Vanderbilt University Medical Center transitioned from a simplistic approach that linked resources to the institutional electronic medical record system, StarPanel, to a value-added service that is designed to deliver highly relevant information. Clinical teams formulate complex patient-specific questions via an evidence-based medicine literature request basket linked to individual patient records. The paper transitions into discussing how the StarPanel approach acted as a springboard for two additional projects that use highly trained knowledge management librarians with informatics expertise to integrate evidence into both order sets and a patient portal, tlibrednaV@htlaeHyM.The Vanderbilt University Eskind Biomedical Library (EBL) has a long history of integrating evidence into clinical teams. More recently it has adapted this expertise into a more scalable approach that allows the integration of evidence into existing medical informatics tools. This paper discusses the institution''s experiences in integrating librarian-filtered evidence into informatics tools and processes, using several examples to illustrate how its knowledge management (KM) team has proactively embedded evidence provision services into the clinical care environment.  相似文献   

Microfluidic carbon-blackened polydimethylsiloxane device with reduced ultra violet background fluorescence for simultaneous two-color ultra violet/visible-laser induced fluorescence detection in single cell analysis     

Galla L  Greif D  Regtmeier J  Anselmetti D 《Biomicrofluidics》2012,6(1):14104-1410410

In single cell analysis (SCA), individual cell-specific properties and inhomogeneous cellular responses are being investigated that is not subjected to ensemble-averaging or heterogeneous cell population effects. For proteomic single cell analysis, ultra-sensitive and reproducible separation and detection techniques are essential. Microfluidic devices combined with UV laser induced fluorescence (UV-LIF) detection have been proposed to fulfill these requirements. Here, we report on a novel microfluidic chip fabrication procedure that combines straightforward production of polydimethylsiloxane (PDMS) chips with a reduced UV fluorescence background (83%-reduction) by using PDMS droplets with carbon black pigments (CBP) as additives. The CBP-droplet is placed at the point of detection, whereas the rest of the chip remains transparent, ensuring full optical control of the chip. We systematically studied the relation of the UV background fluorescence at CBP to PDMS ratios (varying from 1:10 to 1:1000) for different UV laser powers. Using a CBP/PDMS ratio of 1:20, detection of a 100 nM tryptophan solution (S/N = 3.5) was possible, providing a theoretical limit of detection of 86 nM (with S/N = 3). Via simultaneous two color UV/VIS-LIF detection, we were able to demonstrate the electrophoretic separation of an analyte mixture of 500 nM tryptophan (UV) and 5 nM fluorescein (VIS) within 30 s. As an application, two color LIF detection was also used for the electrophoretic separation of the protein content from a GFP-labeled single Spodoptera frugiperda (Sf9) insect cell. Thereby just one single peak could be measured in the visible spectral range that could be correlated with one single peak among others in the ultraviolet spectra. This indicates an identification of the labeled protein γ-PKC and envisions a further feasible identification of more than one single protein in the future.  相似文献   

Distributed model reference adaptive containment control of heterogeneous multi-agent systems with unknown uncertainties and directed topologies     

Dario Giuseppe Lui  Alberto Petrillo  Stefania Santini 《Journal of The Franklin Institute》2021,358(1):737-756

In this paper, the containment control problem of heterogeneous uncertain high-order linear Multi-Agent Systems (MASs) is addressed and solved via a novel fully-Distributed Model Reference Adaptive Control (DMRAC) approach, where each follower computes its adaptive control action on the basis of local measurements, information shared with neighbors (within the communication range) and the matching errors w.r.t. its own reference model, without requiring any previous knowledge of the global directed communication topology structure. The approach inherits the robustness of the direct model reference adaptive control (MRAC) scheme and allows all agents converging towards the convex hull spanned by leaders while fulfilling at the same time local additional performance requirements at single-agent level, such as prescribed settling time, overshoot, etc. The asymptotic stability of the whole closed-loop network is analytically derived by exploiting the Lyapunov theory and the Barbalat lemma, hence proving that each follower converges to the convex hull spanned by the leaders, as well as the boundedness of the adaptive gains. Extensive numerical analysis for heterogeneous MAS composed of stable, unstable and oscillating agent dynamics are presented to validate the theoretical framework and to confirm the effectiveness of the proposed approach.  相似文献   

Identification of histological threshold concepts in health sciences curricula: Students' perception     

Miguel A. Martin-Piedra  Salvador Saavedra-Casado  Antonio Santisteban-Espejo  Fernando Campos  Jesus Chato-Astrain  Oscar Dario Garcia-Garcia  David Sanchez-Porras  Juan de Dios Luna del Castillo  Ismael Angel Rodriguez  Antonio Campos 《Anatomical sciences education》2023,16(1):171-182

Students' metacognitive skills and perceptions are considered important variables for high-quality learning. In this study, students' perceptions were used to identify histological threshold concepts (integrative, irreversible, transformative, and troublesome) in three health sciences curricula. A specific questionnaire was developed and validated to characterize students' perceptions of histological threshold concepts. A sample of 410 undergraduate students enrolled in the dentistry, medicine, and pharmacy degree programs participated in the study. Concepts assessed in the study were clustered to ten categories (factors) by exploratory and confirmatory factor analysis. Concepts linked to tissue organization and tissue functional states received the highest scores from students in all degree programs, suggesting that the process of learning histology requires the integration of both static concepts related to the constituent elements of tissues and dynamic concepts such as stem cells as a tissue renewal substrate, or the euplasic, proplasic and retroplasic states of tissues. The complexity of integrating static and dynamic concepts may pose a challenging barrier to the comprehension of histology. In addition, several differences were detected among the students in different degree programs. Dentistry students more often perceived morphostructural concepts as threshold concepts, whereas medical students highlighted concepts related to two-dimensional microscopic identification. Lastly, pharmacy students identified concepts related to tissue general activity as critical for the comprehension and learning of histology. The identification of threshold concepts through students' perceptions is potentially useful to improve the teaching and learning process in health sciences curricula.  相似文献