Crosslinking of collagen gels by transglutaminase Orban, Janine M.; Wilson, Lorri B.; Kofroth, Jessica A. ...
Journal of biomedical materials research. Part A,
15 March 2004, Volume:
68A, Issue:
4
Journal Article
Recent years have seen a resurgence of interest in using virtual reality (VR) technology to benefit instruction, especially in physics and related subjects. As VR devices improve and become more ...widely available, there remains a number of unanswered questions regarding the impact of VR on student learning and how best to use this technology in the classroom. On the topic of electrostatics, for example, a large, controlled, randomized study performed by Smith et al. A controlled study of stereoscopic virtual reality in freshman electrostatics, "Proceedings of the 2017 Physics Education Research Conference, Cincinnati, OH," PER Conference series (2017), pp. 376-379, found that VR-based instruction had an overall negligible impact on student learning compared to videos or images. However, they did find a strong trend for students who reported frequent video game play to learn better from VR than other media. One possible interpretation of this result is that extended videogame play provides a kind of "training" that enables a student to learn more comfortably in the virtual environment. In the present work we consider if a VR training activity that is unrelated to electrostatics can help prepare students to learn electrostatics from subsequent VR instruction. We find that preliminary VR training leads to a small but statistically significant improvement in student performance on our electrostatics assessment. We also find that student reported game play is still correlated with higher scores on this metric.
Abstract
Background
Transcatheter edge-to-edge tricuspid valve repair (TTVR) is a novel treatment approach in heart failure patients with moderate-to-severe tricuspid regurgitation (TR) at ...prohibitive surgical risk.
Aim
The aim of this study was to investigate the mean tricuspid valve gradient (TVG) over time and compare patient characteristics and outcome of patients with a post-procedure TVG of >3 mmHg vs. ≤3 mmHg.
Methods
All patients who were treated between between March 2016 and October 2018 with TTVR were included in this analysis. Trans-thoracic echocardiographic assessment of TVG was performed pre-procedurally, pre-discharge, after 1, 6, and 12 month.
Results
We treated 145 consecutive patients with moderate-to-severe secondary TR with TTVR. Patients were treated with TTVR for severe TR alone (70 patients) or in combination with mitral valve repair for concomitant severe mitral regurgitation and severe or moderate-severe TR with significant annulus dilatation (75 patients). One clip was implanted in 17 (11.7%), 2 clips in 83 (57.2%), 3 clips in 40 (27.6%) and 4 clips in 4 patients (2.8%). Reduction of at least 1 degree of TR was achieved in 136 Patients (93.8%). The median baseline TVG of all patients was 1 mmHg Inter Quarter Range, IQR 1.0–1.4 mmHg. The median TVG – measured at post-procedural trans-thoracic echocardiogram pre-discharge – increased to 2 mmHg IQR, 1.6–3.0 mmHg and remained constant up to 12 month (2.0 mmHg IQR 1.0–2.0 mmHg).
Of these, twenty-five patients showed an elevated TVG >3 mmHg post-procedurally. Patients with TVG >3 mmHg were younger (73.1±11.0 vs. 77.5±9.2 years, p=0.038) and presented with lower levels of pro-BNP at baseline (median 2276 ng/l IQR, 906–5150 vs. 4182 ng/l 2310–8629, p=0.008) compared to patients with TVG ≤3mmHg. All other baseline characteristics were balanced. There were no differences in procedural success (TR reduction of ≥1 grade in 96% vs. 93.3%, p=0.946) and number of clips implanted (p=0.697). At one month follow-up there were no differences in NYHA class (NYHA class ≥3 in 24% vs. 30.8%, p=0.559), quality of life measured with the Minnesota Living With Heart Failure questionnaire (32.0±22.9 vs. 31.1±16.3, p=0.833), 6 minute walking distance (255.5±140.6 vs. 250.5±111.7 metre, p=0.872). The clinical endpoints 1-year mortality (HR 1.07; 95% CI 0.43–2.65, p=0.88) and the combined endpoint mortality and hospitalization for heart failure at one year (HR 1.07; 95% CI 0.46 to 2.48, p=0.88, see Figure) did not differ between patients with a TVG >3 mmHg vs. patients with a TVG ≤3mmHg.
Figure 1
Conclusion
TTVR results in a small increase in the tricuspid valve gradient, which remains constant up to one year. A small cohort of patients shows an elevated TVG higher than 3 mmHg after the procedure. This elevation has no impact on NYHA class at 1 month and the clinical endpoints mortality and hospitalization for heart failure at 1 year.
A new type of pH-responsive hydrogel surface with varying nanoparticle adsorptivities was fabricated to form a micro-patterned film. To increase its responsivity to environmental pH changes, we ...incorporated graphene oxide (GO) into a poly(methacrylic acid)-polyethylene glycol copolymer. Incorporating GO in the pH-responsive hydrogel significantly increased the adsorption-desorption responsivity of Ag nanoparticles on the gel surface. A pH oscillator in a closed reaction system composed of BrO3(-)-Fe(CN)6(4-)-SO3(2-) facilitated the self-oscillating adsorption-desorption of Ag nanoparticles on the GO-incorporated gel surface. The reversible adsorption-desorption of Ag nanoparticles on the patterned hydrogel surface in response to pH oscillations was determined using UV-visible spectroscopy in aqueous solution. The observed heterogeneous oscillations indicated that the adsorptivity of the gel surface can be reversibly changed on the patterned pH-responsive gel. This phenomenon is similar to various natural biological systems.
We present two-dimensional inviscid hydrodynamic simulations of a protoplanetary disk with an embedded planet, emphasizing the evolution of potential vorticity (the ratio of vorticity to density) and ...its dependence on numerical resolutions. By analyzing the structure of spiral shocks made by the planet, we show that progressive changes of the potential vorticity caused by spiral shocks ultimately lead to the excitation of a secondary instability. We also demonstrate that very high numerical resolution is required to both follow the potential vorticity changes and identify the location where the secondary instability is first excited. Low-resolution results are shown to give the wrong location. We establish the robustness of a secondary instability and its impact on the planet's torque. After the saturation of the instability, the disk shows large-scale nonaxisymmetry, causing the torque on the planet to oscillate with large amplitude. The impact of the oscillating torque on the protoplanet's migration remains to be investigated.
We present detailed characterization of laser-driven fusion and neutron production (
$\sim {10}^5$
/second) using 8 mJ, 40 fs laser pulses on a thin (<1 μm) D
_2$
O liquid sheet employing a ...measurement suite. At relativistic intensity (
$\sim 5\times {10}^{18}$
W/cm
^2$
) and high repetition rate (1 kHz), the system produces deuterium–deuterium (D-D) fusion, allowing for consistent neutron generation. Evidence of D-D fusion neutron production is verified by a measurement suite with three independent detection systems: an EJ-309 organic scintillator with pulse-shape discrimination, a
^3\mathrm{He}$
proportional counter and a set of 36 bubble detectors. Time-of-flight analysis of the scintillator data shows the energy of the produced neutrons to be consistent with 2.45 MeV. Particle-in-cell simulations using the WarpX code support significant neutron production from D-D fusion events in the laser–target interaction region. This high-repetition-rate laser-driven neutron source could provide a low-cost, on-demand test bed for radiation hardening and imaging applications.
Background: Tumour-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by vaccination with dendritic cells (DCs). However, clinical responses to DC-based vaccination have only been ...observed in a minority of patients with solid cancer. Combination with other treatment modalities such as chemotherapy may overcome immunoresistance of cancer cells. It has been shown previously that gemcitabine sensitises human pancreatic carcinoma cells against CTL-mediated lysis. Here, a murine pancreatic carcinoma model was used to investigate whether combination with gemcitabine increases therapeutic efficacy of DC-based vaccination. Methods: Bone marrow-derived DCs from C57BL/6 mice were loaded with UV-irradiated, syngeneic Panc02 carcinoma cells and were administered subcutaneously. For prophylactic vaccination, mice were vaccinated three times at weekly intervals prior to tumour challenge with Panc02 cells. Therapeutic vaccination was started when tumours formed a palpable nodule. Gemcitabine was administered intraperitoneally twice weekly. Results: Prophylactic DC-based vaccination completely prevented subcutaneous and orthotopic tumour development and induced immunological memory as well as tumour antigen-specific CTLs. In the subcutaneous tumour model, therapeutic DC-based vaccination was equally effective as gemcitabine (14% vs 17% survival at day 58 after tumour challenge; controls, 0%). Combination of the two strategies significantly increased survival of tumour-bearing mice (50% at day 58 after tumour challenge). DC-based vaccination also prevented death from pulmonary metastatisation after intravenous injection of Panc02 cells. Conclusion: DC-based immunotherapy may not only be successfully combined with gemcitabine for the treatment of advanced pancreatic carcinoma, but may also be effective in preventing local recurrence or metastatisation in tumour-free patients.
Filamentous fungi harbor the genetic potential for the biosynthesis of several secondary metabolites including various volatile organic compounds (VOCs). Nonetheless, under standard laboratory ...conditions, many of these VOCs are not formed. Furthermore, little is known about enzymes involved in the production of fungal VOCs. To tap these interesting topics, we developed an approach to identify enzymes putatively involved in the fungal VOC biosynthesis. In this chapter, we highlight different fungal cultivation methods and techniques for the extraction of VOCs, including a method that allows the noninvasive analysis of VOCs. In addition using terpene synthases as an example, it is depicted how enzymes putatively involved in VOC synthesis can be identified by means of bioinformatic approaches. Transcriptomic data of chosen genes combined with volatilome data obtained during different developmental stages is demonstrated as a powerful tool to identify enzymes putatively involved in fungal VOC biosynthesis. Especially with regard to subsequent enzyme characterization, this procedure is a target-oriented way to save time and efforts by considering only the most important enzymes.
Computational thinking" (CT) is still a relatively new term in the lexicon of learning objectives and science standards. The term was popularized in an essay by Wing, who said, "To reading, writing ...and arithmetic, we should add computational thinking to every child's analytical ability." Agreeing with this premise, in 2013 the authors of the Next Generation Science Standards (NGSS) included "mathematical and computational thinking" as one of eight essential science and engineering practices that K-12 teachers should strive to develop in their students. There is not yet widespread agreement on the precise definition or implementation of CT, and efforts to assess CT are still maturing, even as more states adopt K-12 computer science standards. In this article we will try to summarize what CT means for a typical introductory (i.e., high school or early college) physics class. This will include a discussion of the ways that instructors may already be incorporating elements of CT in their classes without knowing it.
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