Hasil untuk "nucl-ex"

Menampilkan 20 dari ~857244 hasil · dari arXiv, DOAJ, Semantic Scholar, CrossRef

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S2 Open Access 2017
Senolytic drugs target alveolar epithelial cell function and attenuate experimental lung fibrosis ex vivo

M. Lehmann, M. Korfei, K. Mutze et al.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with poor prognosis and limited therapeutic options. The incidence of IPF increases with age, and ageing-related mechanisms such as cellular senescence have been proposed as pathogenic drivers. The lung alveolar epithelium represents a major site of tissue injury in IPF and senescence of this cell population is probably detrimental to lung repair. However, the potential pathomechanisms of alveolar epithelial cell senescence and the impact of senolytic drugs on senescent lung cells and fibrosis remain unknown. Here we demonstrate that lung epithelial cells exhibit increased P16 and P21 expression as well as senescence-associated β-galactosidase activity in experimental and human lung fibrosis tissue and primary cells. Primary fibrotic mouse alveolar epithelial type (AT)II cells secreted increased amounts of senescence-associated secretory phenotype (SASP) factors in vitro, as analysed using quantitative PCR, mass spectrometry and ELISA. Importantly, pharmacological clearance of senescent cells by induction of apoptosis in fibrotic ATII cells or ex vivo three-dimensional lung tissue cultures reduced SASP factors and extracellular matrix markers, while increasing alveolar epithelial markers. These data indicate that alveolar epithelial cell senescence contributes to lung fibrosis development and that senolytic drugs may be a viable therapeutic option for IPF. Alveolar epithelial cell senescence occurs in IPF and senolytic treatment attenuates experimental lung fibrosis http://ow.ly/nFlz30bsmNm

322 sitasi en Medicine
S2 Open Access 2018
Ex-ante LCA of Emerging Technologies

Stefano Cucurachi, C. Giesen, J. Guinée

Abstract Life cycle assessment (LCA) is a method that has been applied on numerous different types of product systems. Most of these LCA studies concern full-market existing systems. In our common search for a more sustainable society, new technology systems are proposed of which the environmental sustainability still needs to be proven. These emerging technologies often only function at lab- or pilot-scale, and process data are also only available at these scales, and not at observed full-market scales. Performing LCAs of emerging technology systems poses challenges because relevant observations are lacking with regards to the projected final system, projected unit process data, projected characterization factors of new chemicals, etc. These challenges are increasingly recognized and addressed by the LCA community. In this contribution we discuss these challenges, with a special focus on ongoing research and recent developments.

280 sitasi en Business
S2 Open Access 2018
Reducing Ex Vivo Culture Improves the Antileukemic Activity of Chimeric Antigen Receptor (CAR) T Cells

S. Ghassemi, S. Nunez-Cruz, Roddy S. O’Connor et al.

The efficacy of CAR T-cell therapy depends on the engraftment and persistence of T cells following adoptive transfer. Limiting ex vivo culture time of CD19-specific CAR T cells during manufacturing yielded improved persistence and effector function in vivo. The success of chimeric antigen receptor (CAR)–mediated immunotherapy in acute lymphoblastic leukemia (ALL) highlights the potential of T-cell therapies with directed cytotoxicity against specific tumor antigens. The efficacy of CAR T-cell therapy depends on the engraftment and persistence of T cells following adoptive transfer. Most protocols for T-cell engineering routinely expand T cells ex vivo for 9 to 14 days. Because the potential for engraftment and persistence is related to the state of T-cell differentiation, we hypothesized that reducing the duration of ex vivo culture would limit differentiation and enhance the efficacy of CAR T-cell therapy. We demonstrated that T cells with a CAR-targeting CD19 (CART19) exhibited less differentiation and enhanced effector function in vitro when harvested from cultures at earlier (day 3 or 5) compared with later (day 9) timepoints. We then compared the therapeutic potential of early versus late harvested CART19 in a murine xenograft model of ALL and showed that the antileukemic activity inversely correlated with ex vivo culture time: day 3 harvested cells showed robust tumor control despite using a 6-fold lower dose of CART19, whereas day 9 cells failed to control leukemia at limited cell doses. We also demonstrated the feasibility of an abbreviated culture in a large-scale current good manufacturing practice–compliant process. Limiting the interval between T-cell isolation and CAR treatment is critical for patients with rapidly progressing disease. Generating CAR T cells in less time also improves potency, which is central to the effectiveness of these therapies. Cancer Immunol Res; 6(9); 1100–9. ©2018 AACR.

239 sitasi en Medicine
arXiv Open Access 2025
Quarkonia and Deconfined Quark-Gluon Matter in Heavy-Ion Collisions

A. Andronic, R. Arnaldi

In this report, we present an experimental overview of quarkonium results obtained in nucleus-nucleus collisions, with a focus on the data collected at the LHC. We discuss the current understanding of charmonium and bottomonium behavior in the deconfined medium produced in such collisions, comparing the various observables now accessible to state-of-the-art theoretical models. We also discuss the open points and how future heavy-ion experiments aim to clarify these aspects.

en nucl-ex, nucl-th
S2 Open Access 2018
A Phase I Clinical Trial with Ex Vivo Expanded Recipient Regulatory T cells in Living Donor Kidney Transplants

J. Mathew, Jessica H.-Voss, A. Lefever et al.

There is considerable interest in therapeutic transfer of regulatory T cells (Tregs) for controlling aberrant immune responses. Initial clinical trials have shown the safety of Tregs in hematopoietic stem cell transplant recipients and subjects with juvenile diabetes. Our hypothesis is that infusion(s) of Tregs may induce transplant tolerance thus avoiding long-term use of toxic immunosuppressive agents that cause increased morbidity/mortality. Towards testing our hypothesis, we conducted a phase I dose escalation safety trial infusing billions of ex vivo expanded recipient polyclonal Tregs into living donor kidney transplant recipients. Despite variability in recipient’s renal disease, our expansion protocol produced Tregs which met all release criteria, expressing >98% CD4+CD25+ with 80% FOXP3 expression with stable demethylation in the FOXP3 promoter. Functionally, expanded Tregs potently suppressed allogeneic responses and induced the generation of new Tregs in the recipient’s allo-responders in vitro. Within recipients, expanded Tregs amplified circulating Treg levels in a sustained manner. Clinically, all doses of Treg therapy tested were safe with no adverse infusion related side effects, infections or rejection events up to two years post-transplant. This study provides the necessary safety data to advance Treg cell therapy to phase II efficacy trials.

205 sitasi en Medicine
S2 Open Access 2018
3D microfluidic ex vivo culture of organotypic tumor spheroids to model immune checkpoint blockade.

A. Aref, M. Campisi, E. Ivanova et al.

Microfluidic culture has the potential to revolutionize cancer diagnosis and therapy. Indeed, several microdevices are being developed specifically for clinical use to test novel cancer therapeutics. To be effective, these platforms need to replicate the continuous interactions that exist between tumor cells and non-tumor cell elements of the tumor microenvironment through direct cell-cell or cell-matrix contact or by the secretion of signaling factors such as cytokines, chemokines and growth factors. Given the challenges of personalized or precision cancer therapy, especially with the advent of novel immunotherapies, a critical need exists for more sophisticated ex vivo diagnostic systems that recapitulate patient-specific tumor biology with the potential to predict response to immune-based therapies in real-time. Here, we present details of a method to screen for the response of patient tumors to immune checkpoint blockade therapy, first reported in Jenkins et al. Cancer Discovery, 2018, 8, 196-215, with updated evaluation of murine- and patient-derived organotypic tumor spheroids (MDOTS/PDOTS), including evaluation of the requirement for 3D microfluidic culture in MDOTS, demonstration of immune-checkpoint sensitivity of PDOTS, and expanded evaluation of tumor-immune interactions using RNA-sequencing to infer changes in the tumor-immune microenvironment. We also examine some potential improvements to current systems and discuss the challenges in translating such diagnostic assays to the clinic.

182 sitasi en Medicine, Chemistry
S2 Open Access 2018
Therapeutic effects of human mesenchymal stem cell microvesicles in an ex vivo perfused human lung injured with severe E. coli pneumonia

Jeonghyun Park, Seong-Ho Kim, Hyungsun Lim et al.

Background We previously reported that microvesicles (MVs) released by human mesenchymal stem cells (MSC) were as effective as the cells themselves in both Escherichia coli lipopolysaccharide and live bacteria-induced acute lung injury (ALI) mice models. However, it remained unclear whether the biological effect of MSC MV can be applied to human ALI. Methods In the current study, we tested the therapeutic effects of MSC MVs in a well-established ex vivo perfused human model of bacterial pneumonia. Using human donor lungs not used for transplantation, we instilled E. coli bacteria intrabronchially and, 1 hour later, administered MSC MVs into the perfusate as therapy. Results After 6 hours, instillation of E. coli bacteria caused influx of inflammatory cells, which resulted in significant inflammation, lung protein permeability and pulmonary oedema formation. Administration of MSC MV significantly increased alveolar fluid clearance and reduced protein permeability and numerically lowered the bacterial load in the injured alveolus. The beneficial effect on bacterial killing was more pronounced with pretreatment of MSCs with a Toll-like receptor 3 agonist, polyinosinic:polycytidylic acid (Poly (I:C)), prior to the isolation of MVs. Isolated human alveolar macrophages had increased antimicrobial activity with MSC MV treatment in vitro as well. Although oxygenation and lung compliance levels were similar between injury and treatment groups, administration of MSC MVs numerically decreased median pulmonary artery pressure at 6 hours. Conclusions In summary, MSC MVs increased alveolar fluid clearance and reduced lung protein permeability, and pretreatment with Poly (I:C) enhanced the antimicrobial activity of MVs in an ex vivo perfused human lung with severe bacteria pneumonia.

176 sitasi en Medicine
S2 Open Access 2020
Ex vivo cell-based CRISPR/Cas9 genome editing for therapeutic applications.

Yamin Li, Z. Glass, Mingqian Huang et al.

The recently developed CRISPR/Cas9 technology has revolutionized the genome engineering field. Since 2016, increasing number of studies regarding CRISPR therapeutics have entered clinical trials, most of which are focusing on the ex vivo genome editing. In this review, we highlight the ex vivo cell-based CRISPR/Cas9 genome editing for therapeutic applications. In these studies, CRISPR/Cas9 tools were used to edit cells in vitro and the successfully edited cells were considered as therapeutics, which can be introduced into patients to treat diseases. Considering a large number of previous reviews have been focused on the CRISPR/Cas9 delivery methods and materials, this review provides a different perspective, by mainly introducing the targeted conditions and design strategies for ex vivo CRISPR/Cas9 therapeutics. Brief descriptions of the history, functionality, and applications of CRISPR/Cas9 systems will be introduced first, followed by the design strategies and most significant results from previous research that used ex vivo CRISPR/Cas9 genome editing for the treatment of conditions or diseases. The last part of this review includes general information about the status of CRISPR/Cas9 therapeutics in clinical trials. We also discuss some of the challenges as well as the opportunities in this research area.

89 sitasi en Biology, Medicine
S2 Open Access 2019
Radiation Force as a Physical Mechanism for Ultrasonic Neurostimulation of the Ex Vivo Retina

Mike D. Menz, Patrick Ye, K. Firouzi et al.

Focused ultrasound has been shown to be effective at stimulating neurons in many animal models, both in vivo and ex vivo. Ultrasonic neuromodulation is the only noninvasive method of stimulation that could reach deep in the brain with high spatial-temporal resolution, and thus has potential for use in clinical applications and basic studies of the nervous system. Understanding the physical mechanism by which energy in a high acoustic frequency wave is delivered to stimulate neurons will be important to optimize this technology. We imaged the isolated salamander retina of either sex during ultrasonic stimuli that drive ganglion cell activity and observed micron scale displacements, consistent with radiation force, the nonlinear delivery of momentum by a propagating wave. We recorded ganglion cell spiking activity and changed the acoustic carrier frequency across a broad range (0.5–43 MHz), finding that increased stimulation occurs at higher acoustic frequencies, ruling out cavitation as an alternative possible mechanism. A quantitative radiation force model can explain retinal responses and could potentially explain previous in vivo results in the mouse, suggesting a new hypothesis to be tested in vivo. Finally, we found that neural activity was strongly modulated by the distance between the transducer and the electrode array showing the influence of standing waves on the response. We conclude that radiation force is the dominant physical mechanism underlying ultrasonic neurostimulation in the ex vivo retina and propose that the control of standing waves is a new potential method to modulate these effects. SIGNIFICANCE STATEMENT Ultrasonic neurostimulation is a promising noninvasive technology that has potential for both basic research and clinical applications. The mechanisms of ultrasonic neurostimulation are unknown, making it difficult to optimize in any given application. We studied the physical mechanism by which ultrasound is converted into an effective energy form to cause neurostimulation in the retina and find that ultrasound acts via radiation force leading to a mechanical displacement of tissue. We further show that standing waves have a strong modulatory effect on activity. Our quantitative model by which ultrasound generates radiation force and leads to neural activity will be important in optimizing ultrasonic neurostimulation across a wide range of applications.

120 sitasi en Materials Science, Medicine
S2 Open Access 2019
The Future of Ex-Ante LCA? Lessons Learned and Practical Recommendations

M. Buyle, A. Audenaert, P. Billen et al.

Every decision-oriented life cycle assessment (LCAs) entails, at least to some extent, a future-oriented feature. However, apart from the ex-ante LCAs, the majority of LCA studies are retrospective in nature and do not explicitly account for possible future effects. In this review a generic theoretical framework is proposed as a guideline for ex-ante LCA. This framework includes the entire technology life cycle, from the early design phase up to continuous improvements of mature technologies, including their market penetration. The compatibility with commonly applied system models yields an additional aspect of the framework. Practical methods and procedures are categorised, based on how they incorporate future-oriented features in LCA. The results indicate that most of the ex-ante LCAs focus on emerging technologies that have already gone through some research cycles within narrowly defined system boundaries. There is a lack of attention given to technologies that are at a very early development stage, when all options are still open and can be explored at a low cost. It is also acknowledged that technological learning impacts the financial and environmental performance of mature production systems. Once technologies are entering the market, shifts in market composition can lead to substantial changes in environmental performance.

120 sitasi en Economics
S2 Open Access 2019
Ex ante and ex post effects of hybrid index insurance in Bangladesh

R. Hill, Neha Kumar, N. Magnan et al.

This study assesses both the demand for and effectiveness of an index insurance product designed to help smallholder farmers in Bangladesh manage crop production risk during the monsoon season. Villages were randomized into either an insurance treatment or a comparison group, and discounts and rebates were randomly allocated across treatment villages to encourage insurance take-up and to allow for the estimation of the price-elasticity of insurance demand. Among those offered insurance, we find demand to be fairly price elastic, with discounts significantly more successful in stimulating demand than rebates. Purchasing insurance yields both ex ante risk management effects as well as ex post income effects on agricultural production practices. The risk management effects lead to an expansion of cultivated area with concomitant increases in agricultural input expenditures during the monsoon season. The income effects lead to more intensive rice production during the subsequent dry season, with more intensive use of both irrigation and fertilizers, resulting in higher yields and higher total rice production.

104 sitasi en Business, Medicine
S2 Open Access 2019
Ex situ collections and their potential for the restoration of extinct plants

T. Abeli, S. Dalrymple, S. Godefroid et al.

The alarming current and predicted species extinction rates have galvanized conservationists in their efforts to avoid future biodiversity losses, but for species extinct in the wild, few options exist. We posed the questions, can these species be restored, and, if so, what role can ex situ plant collections (i.e., botanic gardens, germplasm banks, herbaria) play in the recovery of plant genetic diversity? We reviewed the relevant literature to assess the feasibility of recovering lost plant genetic diversity with using ex situ material and the probability of survival of subsequent translocations. Thirteen attempts to recover species extinct in the wild were found, most of which used material preserved in botanic gardens (12) and seed banks (2). One case of a locally extirpated population was recovered from herbarium material. Eight (60%) of these cases were successful or partially successful translocations of the focal species or population; the other 5 failed or it was too early to determine the outcome. Limiting factors of the use of ex situ source material for the restoration of plant genetic diversity in the wild include the scarcity of source material, low viability and reduced longevity of the material, low genetic variation, lack of evolution (especially for material stored in germplasm banks and herbaria), and socioeconomic factors. However, modern collecting practices present opportunities for plant conservation, such as improved collecting protocols and improved cultivation and storage conditions. Our findings suggest that all types of ex situ collections may contribute effectively to plant species conservation if their use is informed by a thorough understanding of the aforementioned problems. We conclude that the recovery of plant species currently classified as extinct in the wild is not 100% successful, and the possibility of successful reintroduction should not be used to justify insufficient in situ conservation.

104 sitasi en Biology, Medicine
CrossRef Open Access 2022
Foreword

Editorial board

Making Archaeology Public. A View from the Mediterranean, Eastern Europe and Beyond
 The concept of Public Archaeology has profoundly changed since Mc Grimsey’s first formulation in the early 1970s, as it developed a solid conceptual and practical framework along the years that makes it now an independent branch of archaeology. However, in English-speaking and Northern European countries, the perception of archaeology as a common good was widely spread even before the actual formalization of Public Archaeology as a specific curriculum offered by several universities. Not surprisingly, such an earlier interest led to the development of a markedly North Europe-centric perspective on the topic, which keeps steering much of the current reflection on Public Archaeology despite the emergence of multiple and alternative standpoints on the matter, further deepening the great divide between the archaeologies of Northern and Southern European countries.

S2 Open Access 2018
Ex vivo diffusion MRI of the human brain: Technical challenges and recent advances

A. Roebroeck, K. Miller, M. Aggarwal

This review discusses ex vivo diffusion magnetic resonance imaging (dMRI) as an important research tool for neuroanatomical investigations and the validation of in vivo dMRI techniques, with a focus on the human brain. We review the challenges posed by the properties of post‐mortem tissue, and discuss state‐of‐the‐art tissue preparation methods and recent advances in pulse sequences and acquisition techniques to tackle these. We then review recent ex vivo dMRI studies of the human brain, highlighting the validation of white matter orientation estimates and the atlasing and mapping of large subcortical structures. We also give particular emphasis to the delineation of layered gray matter structure with ex vivo dMRI, as this application illustrates the strength of its mesoscale resolution over large fields of view. We end with a discussion and outlook on future and potential directions of the field.

126 sitasi en Computer Science, Medicine

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