Molecularly imprinted polymers (MIPs) have emerged as bespoke materials with versatile molecular applications. In this study, we propose a proof of concept for a methodology employing molecular ...dynamics (MD) simulations to guide the selection of functional monomers for curcuminoid binding in MIPs. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin are phenolic compounds widely employed as spices, pigments, additives, and therapeutic agents, representing the three main curcuminoids of interest. Through MD simulations, we investigated prepolymerization mixtures composed of various functional monomers, including acrylamide (ACA), acrylic acid (AA), methacrylic acid (MAA), and N-vinylpyrrolidone (NVP), with ethylene glycol dimethacrylate (EGDMA) as the cross-linker and acetonitrile as the solvent. Curcumin was selected as the template molecule due to its structural similarity to the other curcuminoids. Notably, the prepolymerization mixture containing NVP as the functional monomer demonstrated superior molecular recognition capabilities toward curcumin. This observation was supported by higher functional monomer molecules surrounding the template, a lower total nonbonded energy between the template and monomer, and a greater number of hydrogen bonds in the aggregate. These findings suggest a stronger affinity between the functional monomer NVP and the template. We synthesized, characterized, and conducted binding tests on the MIPs to validate the MD simulation results. The experimental binding tests confirmed that the MIP-NVP exhibited higher binding capacity. Consequently, based on MD simulations, our computational methodology effectively guided the selection of the functional monomer, leading to MIPs with binding capacity for curcuminoids. The outcomes of this study provide a valuable reference for the rational design of MIPs through MD simulations, facilitating the selection of components for MIPs. This computational approach holds the potential for extension to other templates, establishing a robust methodology for the rational design of MIPs.
This paper investigates the results of a Second Law analysis applied to a mobile air conditioning system (MACs) integrated with an internal heat exchanger (IHX) by considering R152a, R1234yf and ...R1234ze as low global warming potential (GWP) refrigerants and establishing R134a as baseline. System simulation is performed considering the maximum value of entropy generated in the IHX. The maximum entropy production occurs at an effectiveness of 66% for both R152a and R134a, whereas for the cases of R1234yf and R1234ze occurs at 55%. Sub-cooling and superheating effects are evaluated for each one of the cases. It is also found that the sub-cooling effect shows the greatest impact on the cycle efficiency. The results also show the influence of isentropic efficiency on relative exergy destruction, resulting that the most affected components are the compressor and the condenser for all of the refrigerants studied herein. It is also found that the most efficient operation of the system resulted to be when using the R1234ze refrigerant.
This paper presents a systematic approach to compute the angularity and the axiality indices for a Schönflies parallel manipulator. Angularity index may be considered as a measure of the sensitivity ...of the mobile platform to changes in rotation, while axiality index can be used to measure the sensitivity of the OP of the mobile platform to changes in translation. Since both indices were inspired by very fundamental concepts of classical kinematics (angular velocity vector and helicoidal velocity field), they offer a clear and simple physical meaning, which may be useful to the designer of parallel manipulators. Moreover, both dexterity indices do not require obtaining a dimensionally homogeneous Jacobian matrix, nor do they depend on having similar types of actuators in each manipulator's leg. Detailed numerical examples are given in order to illustrate the computation of the dexterity indices.
Polymers are part of our lives; scientists dedicated to polymer science design new materials thinking about more eco-friendly methodologies and satisfying people's needs. In most universities, ...polymer science is taught by academics associated with the traditional chemistry departments (organic, analytical, physical, and inorganic chemistry). In this article, we show how polymers are taught in a department specifically dedicated to this topic. We present the history of the Department of Polymers in the Faculty of Chemical Sciences at the University of Concepcion (the only department of this type in Chile). Initially, the Department of Polymers offered a few undergraduate and graduate courses; now, polymer science courses at the University of Concepcion have become an integral part of the curriculum for seven programs -- pedagogy in chemistry, biochemistry, bioengineering, civil engineering in materials, chemical analysis, chemistry, and civil engineering in chemistry. We discuss the influence of this department in the curricular design of these seven programs at the University of Concepcion. We offer a detailed description of the polymer-based courses incorporated into the curriculum of some programs, and we discuss how the numbers of graduate and undergraduate theses involving polymer science have increased at the Faculty of Chemical Sciences since the creation of the Department of Polymers in 1974.
Polymers are part of our lives; scientists dedicated to polymer science design new materials thinking about more eco-friendly methodologies and satisfying people’s needs. In most universities, ...polymer science is taught by academics associated with the traditional chemistry departments (organic, analytical, physical, and inorganic chemistry). In this article, we show how polymers are taught in a department specifically dedicated to this topic. We present the history of the Department of Polymers in the Faculty of Chemical Sciences at the University of Concepción (the only department of this type in Chile). Initially, the Department of Polymers offered a few undergraduate and graduate courses; now, polymer science courses at the University of Concepción have become an integral part of the curriculum for seven programspedagogy in chemistry, biochemistry, bioengineering, civil engineering in materials, chemical analysis, chemistry, and civil engineering in chemistry. We discuss the influence of this department in the curricular design of these seven programs at the University of Concepción. We offer a detailed description of the polymer-based courses incorporated into the curriculum of some programs, and we discuss how the numbers of graduate and undergraduate theses involving polymer science have increased at the Faculty of Chemical Sciences since the creation of the Department of Polymers in 1974.
This paper presents a systematic approach to formulate a closed-form solution of the forward displacement analysis for a Schönflies parallel manipulator. The effectiveness of the method relies upon ...the solution of only one polynomial equation in terms of just one of the involved variables. Once the roots of this polynomial are found, the remaining variables are readily determined from backward substitution. In addition, the proposed method works equally well for general geometries and for special geometries of the mobile platform and fixed platform of the manipulator. Finally, a fully detailed case study is reported.
Function generation with the RRRCR spatial linkage Cervantes-Sánchez, J. Jesús; Rico-Martínez, José M.; Pérez-Muñoz, Víctor H. ...
Mechanism and machine theory,
April 2014, 2014-04-00, 20140401, Letnik:
74
Journal Article
Rays and skates are fish with flattened, pancake-shaped bodies that frequent shallow water, where they often lie hidden under the sand. Some of the batoid species are characterized by a stinger with ...serrated edges, which is covered by a tegument made up of specialized cells that secrete toxins and enzymes with proteolytic activity. Stingray injuries to humans are common in warm coastal regions. In this report, we present a case of an injury due to the insertion of a barb from a Pacific cownose ray, Rhinoptera steindachneri
We assess the tissue complications due to the retention of the spine in the foot, the subsequent infection that caused tissue necrosis, and the reconstructive surgery performed. Based on previous experience, we highly recommend performing diagnostic procedures such as soft tissue radiographs and MRI to ensure the absence of the barb within the wound and thereby avoid further complications. Current textbook treatment is based on limited scientific studies, case reports, and successful clinical treatment of many victims.
Abstract
Background
Seasonal influenza infection may cause significant morbidity and mortality in transplant recipients. The purpose of this study was to assess the epidemiology of symptomatic ...influenza infection posttransplant and determine risk factors for severe disease.
Methods
Twenty centers in the United States, Canada, and Spain prospectively enrolled solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT) recipients with microbiologically confirmed influenza over 5 consecutive years (2010-2015). Demographics, microbiology data, and outcomes were collected. Serial nasopharyngeal swabs were collected at diagnosis and upto 28 days, and quantitative polymerase chain reaction for influenza A was performed.
Results
We enrolled 616 patients with confirmed influenza (477 SOT; 139 HSCT). Pneumonia at presentation was in 134 of 606 (22.1%) patients. Antiviral therapy was given to 94.1% for a median of 5 days (range, 1-42 days); 66.5% patients were hospitalized and 11.0% required intensive care unit (ICU) care. The receipt of vaccine in the same influenza season was associated with a decrease in disease severity as determined by the presence of pneumonia (odds ratio OR, 0.34 95% confidence interval {CI}, .21-.55, P < .001) and ICU admission (OR, 0.49 95% CI, .26-.90, P = .023). Similarly, early antiviral treatment (within 48 hours) was associated with improved outcomes. In patients with influenza A, pneumonia, ICU admission, and not being immunized were also associated with higher viral loads at presentation (P = .018, P = .008, and P = .024, respectively).
Conclusions
Annual influenza vaccination and early antiviral therapy are associated with a significant reduction in influenza-associated morbidity, and should be emphasized as strategies to improve outcomes of transplant recipients.
In this multicenter, multiyear, prospective, observational study of influenza infection in transplant recipients, we found that vaccination in the same season and early antiviral therapy are protective for lower respiratory tract infection and intensive care unit admission.
PDF
