29 research outputs found
Ratiometric electrochemical detection of Pd•••π interactions:application towards electrochemical molecular logic gates
<p>The widespread and large scale use of platinum group metals, especially palladium, in a wide variety of industrial applications has seen their levels in wastewater streams, roadside dust and even pharmaceuticals significantly rise over recent years. Due to the possible environmental damage and potential health risk this may cause, there is now substantial demand for inexpensive, efficient and robust methods for the detection of palladium. Based upon self-immolative linker technologies, we have designed and synthesised a number of allyl ether-functionalised electrochemical probes to determine the optimum probe structure required to deliver a ratiometric electrochemical detection method capable of achieving a limit of detection of <1 mg/mL within 20 min through the use of disposable screen-printed carbon electrodes. Combined with an enzymatic assay, this method was then used to achieve a proof-of-principle ratiometric electrochemical molecular logic gate.</p
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Ratiometric electrochemical detection of alkaline phosphatase
A novel ferrocene-derived substrate for the ratiometric electrochemical detection of alkaline phosphatase (ALP) was designed and synthesised. It was demonstrated to be an excellent electrochemical substrate for the ALP-labelled enzyme-linked immunosorbent assay (ELISA). This journal is</p
Multi-disciplinary design optimization of transonic fan blade design using analytical target cascading
Analytical Target Cascading (ATC), a multilayer multidisciplinary design optimization (MDO) formulation employed on a transonic fan design problem. This paper demonstrates the ATC solution process including the specific way of initializing the problem and handling system level and discipline level targets. High-fidelity analysis tools for aerodynamics, structure and dynamics disciplines have been used. A multi-level parameterization of the fan blade is considered for reducing the number of design variables. The overall objective is the transonic fan efficiency improvement under structure and dynamics constraints. This design approach is applied to the redesign of the NASA Rotor 67. The overall study explores the key points of implementation of ATC on transonic fan design practical problem.</jats:p
A Transmuted Modified Power-Generated Family of Distributions with Practice on Submodels in Insurance and Reliability
In this article, we propose a new transmuted modified power-generalized family of distributions constructed from the transmuted-generated and modified power-generated families. The proposed approach is flexible and provides a tradeoff between the two baseline families. For a prime study, we identify the main characteristics of the new transmuted modified power family, such as the asymptotic results, quantile function, series representation, and the various kinds of moment measures. By using the exponential distribution as the baseline, a new three-parameter lifetime distribution is constructed. The associated probability functions (density and hazard rate) are flexible and have a variety of asymmetric shapes, which make them attractive for statistical purposes. In particular, for the related probability density function, reversed-J, unimodal, and right-skewed shapes are observed. Measures relating to risk theory are also computed, such as the value at risk and the expected shortfall. By using both simulation analysis and the maximum likelihood approach, the estimation of the model parameters is evaluated. The effectiveness of the proposed model is demonstrated by two real-world cases (one in insurance and the other in reliability), and we show that it yields better fits when compared to other extended models connected to the exponential model
Ratiometric electrochemical detection of Pd•••π interactions: application towards electrochemical molecular logic gates
Green bio-assisted synthesis, characterization and biological evaluation of biocompatible ZnO NPs synthesized from different tissues of milk thistle (Silybum marianum)
The purpose of the current study was green synthesis of ZnO-nanoparticles (NPs) from different tissues of Silybum marianum (L.) Gaernt. (i.e., seeds, wild plant, in vitro derived plantlets and callus cultures) followed by extensive characterization and evaluation of their biological potency. ZnO-NPs thus synthesized were subjected to characterization using standard techniques such as XRD, FTIR and SEM. Thermal stability of synthesized NPs was also evaluated using thermo-gravimetric analysis. Highly stable crystalline NPs with size ranging between 30.8 and 46.0 nm were obtained from different tissues of S. marianum. These NPs have revealed a wide range of biological applications showing antioxidant, moderate α-amylase inhibitor, antibacterial and cytotoxic potencies. The highest antibacterial activity (20 ± 0.98 mm) was shown by seed extract-mediated ZnO NPs against Staphylococcus aureus (ATCC-6538). Seed extract-mediated ZnO NPs also showed the most potent antioxidant activity (27.7 ± 0.9 µgAAE/mg, 23.8 ± 0.7 µgAAE/mg and 12.7 ± 1.9% total antioxidant capacity (TAC), total reducing power (TRP) and DPPH-free radical scavenging assay (FRSA), respectively). All of the synthesized ZnO NPs also showed cytotoxic activity against the hepato-cellular carcinoma (HepG2) human cells. Interestingly, these ZnO NPs were also highly biocompatible, as evidenced by the brine shrimp lethality and human red blood cells hemolytic assays. Among all of the NPs synthesized and used, the effect of seed extract-mediated NPs was found to be most promising for future applications
Green Bio-Assisted Synthesis, Characterization and Biological Evaluation of Biocompatible ZnO NPs Synthesized from Different Tissues of Milk Thistle (Silybum marianum)
The purpose of the current study was green synthesis of ZnO-nanoparticles (NPs) from different tissues of Silybum marianum (L.) Gaernt. (i.e., seeds, wild plant, in vitro derived plantlets and callus cultures) followed by extensive characterization and evaluation of their biological potency. ZnO-NPs thus synthesized were subjected to characterization using standard techniques such as XRD, FTIR and SEM. Thermal stability of synthesized NPs was also evaluated using thermo-gravimetric analysis. Highly stable crystalline NPs with size ranging between 30.8 and 46.0 nm were obtained from different tissues of S. marianum. These NPs have revealed a wide range of biological applications showing antioxidant, moderate α-amylase inhibitor, antibacterial and cytotoxic potencies. The highest antibacterial activity (20 ± 0.98 mm) was shown by seed extract-mediated ZnO NPs against Staphylococcus aureus (ATCC-6538). Seed extract-mediated ZnO NPs also showed the most potent antioxidant activity (27.7 ± 0.9 µgAAE/mg, 23.8 ± 0.7 µgAAE/mg and 12.7 ± 1.9% total antioxidant capacity (TAC), total reducing power (TRP) and DPPH-free radical scavenging assay (FRSA), respectively). All of the synthesized ZnO NPs also showed cytotoxic activity against the hepato-cellular carcinoma (HepG2) human cells. Interestingly, these ZnO NPs were also highly biocompatible, as evidenced by the brine shrimp lethality and human red blood cells hemolytic assays. Among all of the NPs synthesized and used, the effect of seed extract-mediated NPs was found to be most promising for future applications.</jats:p
Acute performance of a novel restorative transcatheter aortic valve: preclinical results
Aims: The Xeltis aortic valve leaflets are made from a bioabsorbable supramolecular polymer that guides the tissue to restoring itself. It is mounted on a self-expanding nitinol frame that includes three feelers and a native leaflet clipping mechanism. We sought to investigate the acute valve performance in a preclinical setting. Methods and results: In 33 sheep, 26 mm Xeltis aortic valves were transapically implanted in a 23 mm native annulus. Aortography (analysable, n = 28) and echocardiography (analysable, n = 20) images were acquired immediately after implantation of the Xeltis aortic valve to assess the acute device performance. On echocardiography, transvalvular peak pressure gradient (PG) was 7.4 (IQR: 6.0-8.9) mmHg, mean PG was 4.0 (IQR: 3.0-5.0) mmHg, and effective orifice area was 2.2 (IQR: 1.6-2.5) cm(2). Trace (n = 6), mild (n = 2) and no (n = 12) transvalvular aortic regurgitation (AR) were seen. Likewise, no paravalvular AR was detected in 7 cases, whereas trace, mild and moderate were seen in 7, 5 and 1 cases, respectively. On quantitative videodensitometric AR (VD-AR) assessment, a median value of 6% (IQR: 1-12%) of AR was seen. Three cases had a VD-AR superior to 17%, which has a prognostic significance. Out of these three cases, two had echocardiographic assessment available, which showed mild and moderate paravalvular regurgitation due to inadequate leaflet clipping. Conclusions: In a transapical ovine model, the novel restorative transcatheter aortic valve with bioabsorbable leaflets demonstrated good haemodynamic performance comparable to commercially available devices. The highly porous polymeric leaflets demonstrated good competence immediately after implantation with no cases having > mild transvalvular A
