194 research outputs found
PUFFIN: A Path-Unifying Feed-Forward Interfaced Network for Vapor Pressure Prediction
Accurately predicting vapor pressure is vital for various industrial and
environmental applications. However, obtaining accurate measurements for all
compounds of interest is not possible due to the resource and labor intensity
of experiments. The demand for resources and labor further multiplies when a
temperature-dependent relationship for predicting vapor pressure is desired. In
this paper, we propose PUFFIN (Path-Unifying Feed-Forward Interfaced Network),
a machine learning framework that combines transfer learning with a new
inductive bias node inspired by domain knowledge (the Antoine equation) to
improve vapor pressure prediction. By leveraging inductive bias and transfer
learning using graph embeddings, PUFFIN outperforms alternative strategies that
do not use inductive bias or that use generic descriptors of compounds. The
framework's incorporation of domain-specific knowledge to overcome the
limitation of poor data availability shows its potential for broader
applications in chemical compound analysis, including the prediction of other
physicochemical properties. Importantly, our proposed machine learning
framework is partially interpretable, because the inductive Antoine node yields
network-derived Antoine equation coefficients. It would then be possible to
directly incorporate the obtained analytical expression in process design
software for better prediction and control of processes occurring in industry
and the environment
Effect of the Ages of Parasitoid and Host Eggs on Telenomus podisi (Hymenoptera: Platygastridae) Parasitism.
This study investigates the influence of parasitoid age and egg age of the hosts Euschistus heros (Fabricius) and Dichelops melacanthus (Dallas) on parasitism of Telenomus podisi Ashmead. Six separate bioassays were conducted: parasitism on eggs of E. heros (bioassay 1) and D. melacanthus (bioassay 2) by T. podisi females of different age (1, 5, and 10 days old); parasitism by T. podisi on eggs of different age (1, 2, 3, 4, and 5 days of embryonic development) of the hosts E. heros (bioassay 3) and D. melacanthus (bioassay 4); preference of T. podisi females for eggs at different embryonic developmental stages (eggs of 1, 2, 3, 4, and 5 days) of the hosts E. heros (bioassay 5) and D. melacanthus (bioassay 6). The age of T. podisi females and their hosts affected parasitism on both E. heros and D. melacanthus eggs. Overall, the parasitism rate was higher in older than younger parasitoids, independent of the tested host species, and host eggs between 1 and 3 days old were similarly parasitized. Thus, in T. podisi mass rearing facilities, it is recommended to use older adults (5 to 10 days old) as mother wasps to increase parasitism on the offered eggs. In addition, when hosts are completely absent in the field, or climatic conditions are unfavorable for release, mass-reared adults can be kept in the laboratory (25°C) for up to 10 days for later release in the field without any impairment of their subsequent parasitism performance
Magnetic nanoparticles covered by or entrapped in lipid bilayers: Advances towards dual cancer therapy
In this work, both aqueous magnetoliposomes (magnetic nanoparticles entrapped in liposomes) and solid magnetoliposomes (a cluster of particles covered by a lipid bilayer) have been developed, containing either nickel/silica core/shell nanoparticles, nickel ferrite or manganese ferrite nanoparticles, with diameters below 150 nm, suitable for biomedical applications. Moreover, both aqueous (AMLs) and solid (SMLs) magnetoliposomes show a superparamagnetic behavior, the SMLs exhibiting a high saturation magnetization.Financial support by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013 and UID/QUI/00686/2016 is acknowledged. A.R.O Rodrigues thanks the FCT for SFRH/BD/90949/2012 PhD grant and funding to MAP-Fis Doctoral Program.info:eu-repo/semantics/publishedVersio
Magnetic liposomes based on nickel ferrite nanoparticles as nanocarriers for new potential antitumor compounds
Guided transport of biologically active molecules (most of them toxic and with systemic side
effects) to target specific sites in human body has been a focus of research in therapeutics in
the past years. Magnetoliposomes (liposomes entrapping magnetic nanoparticles) are of large
importance, as they can overcome many pharmacokinetics problems and can be guided and
localized to the therapeutic site of interest by external magnetic field gradients [1,2]. In this
work, nickel ferrite nanoparticles (NPs) with size distribution of 11±5 nm were obtained.
Synthesized NPs show superparamagnetic behaviour at room temperature (magnetic
squareness of 7.2×10-5 and coercivity field of 12 Oe), being suitable for biological applications.
These NPs were either entrapped in liposomes, originating aqueous magnetoliposomes
(AMLs), or covered with a lipid bilayer, forming dry magnetoliposomes (DMLs), the last ones
prepared by a new promising route. Recently, AMLs and DMLs containing nickel-based
nanoparticles were successfully prepared and characterized [3]. A potential antitumor
compound [4] was successfully incorporated into the lipid bilayer of magnetoliposomes. DMLs
structure was evaluated by FRET (Förster Resonance Energy Transfer) measurements
between the fluorescent-labeled lipids NBD-C12-HPC (donor) included in the second lipid layer
and rhodamine B DOPE (acceptor) in the first lipid layer. A FRET efficiency of 23% was
calculated, with a corresponding donor-acceptor distance (r) of 3.11 nm, confirming DMLs
structure. Preliminary assays of the non-specific interactions of both types of magnetoliposomes
with biological membranes (modeled by giant unilamellar vesicles, GUVs) were performed,
keeping in mind future applications of drug delivery using this type of magnetic systems.
Membrane fusion between magnetoliposomes and GUVs was confirmed by FRET.FCT - Fundação para a Ciência e a Tecnologia, PEst-C/FIS/UI0607/2013 (F-COMP-01-0124-FEDER-022711
Magnetoliposomes based on manganese ferrite/gold nanoparticles for applications in cancer therapy
In this work, different types of magnetic/plasmonic MnFe2O4/Au nanoparticles were prepared, including core-shell and decorated nanoparticles. The structural, spectroscopic and magnetic properties were evaluated. The nanoparticles were covered with a lipid bilayer or entrapped in liposomes.POPH-QREN; FCT Strategic Funding to CF-UM-UP (UID/FIS/04650/2013); FCT Strategic Funding to CQUM (UID/QUI/00686/2016); FCT PhD Grant SFRH/BD/90949/2012info:eu-repo/semantics/publishedVersio
Development of multifunctional liposomes containing magnetic/plasmonic MnFe2O4/Au core/shell nanoparticles
Multifunctional liposomes containing manganese ferrite/gold core/shell nanoparticles were developed. These magnetic/plasmonic nanoparticles were covered by a lipid bilayer or entrapped in liposomes, which form solid or aqueous magnetoliposomes as nanocarriers for simultaneous chemotherapy and phototherapy. The core/shell nanoparticles were characterized by UV/Visible absorption, X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Superconducting Quantum Interference Device (SQUID). The magnetoliposomes were characterized by Dynamic Light Scattering (DLS) and TEM. Fluorescence-based techniques (FRET, steady-state emission, and anisotropy) investigated the incorporation of a potential anti-tumor drug (a thienopyridine derivative) in these nanosystems. The core/shell nanoparticles exhibit sizes of 25 ± 2 nm (from TEM), a plasmonic absorption band (λmax = 550 nm), and keep magnetic character. XRD measurements allowed for the estimation of 13.3 nm diameter for manganese ferrite core and 11.7 nm due to the gold shell. Aqueous magnetoliposomes, with hydrodynamic diameters of 152 ± 18 nm, interact with model membranes by fusion and are able to transport the anti-tumor compound in the lipid membrane, with a high encapsulation efficiency (EE (%) = 98.4 ± 0.8). Solid magnetoliposomes exhibit hydrodynamic diameters around 140 nm and also carry successfully the anticancer drug (with EE (%) = 91.2 ± 5.2), while also being promising as agents for phototherapy. The developed multifunctional liposomes can be promising as therapeutic agents for combined chemo/phototherapy.European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the
framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013) and CQUM (UID/QUI/00686/2016) and
through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by the
European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. The APC was also
funded by FCT. A.R.O.R. acknowledges FCT for a research grant under UID/FIS/04650/2013 funding.info:eu-repo/semantics/publishedVersio
Magnetic liposomes containing calcium ferrite nanoparticles for breast cancer therapy
In this work, calcium ferrite nanoparticles were prepared and characterized. The structural and magnetic properties of the nanoparticles were evaluated by XRD, TEM and SQUID. The synthesized nanoparticles were either entrapped in liposomes, originating aqueous magnetoliposomes (AMLs), or covered with a lipid bilayer, forming solid magnetoliposomes (SMLs). Magnetoliposomes present average diameters around 150 nm, suitable for biomedical applications.
The magnetoliposomes were loaded with new potential anticancer drugs, thienopyridine derivatives, with a strong antitumor activity against breast cancer cells.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013) and of CQUM (UID/QUI/00686/2013). FCT, POPH-QREN and FSE are acknowledged for the PhD grants of A. R. O. Rodrigues (SFRH/BD/90949/2012) and V. A. Machado (SFRH/BD/77373/2011) and for financial support to MAP-Fis Joint Doctoral Programme.info:eu-repo/semantics/publishedVersio
Magnetic/plasmonic liposomes as nanocarriers for novel antitumor tricyclic lactones against non-small cell lung cancer
In this work, MnFe2O4/Au core/shell nanoparticles (NPs) and MnFe2O4 NPs decorated with Au NPs
were synthesized and the structural, spectroscopic and magnetic properties evaluated. The prepared
NPs were covered with a lipid bilayer, forming solid magnetoliposomes (SMLs). The heating capabilities of the nanosystems were assessed through the fluorescence quenching of Nile Red (incorporated in the lipid bilayer of the SMLs) under irradiation.UIDB/04650/2020; PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020
Magnetoliposomes containing multicore nanoparticles and a new antitumor thienopyridine compound with potential application in chemo/thermotherapy
Multicore magnetic nanoparticles of manganese ferrite were prepared using carboxymethyl dextran as an agglutinating compound or by an innovative method using melamine as a cross-coupling agent. The nanoparticles prepared using melamine exhibited a flower-shape structure, a saturation magnetization of 6.16 emu/g and good capabilities for magnetic hyperthermia, with a specific absorption rate (SAR) of 0.14 W/g. Magnetoliposome-like structures containing the multicore nanoparticles were prepared, and their bilayer structure was confirmed by FRET (Förster Resonance Energy Transfer) assays. The nanosystems exhibited sizes in the range of 250–400 nm and a low polydispersity index. A new antitumor thienopyridine derivative, 7-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]thieno[3,2-b]pyridine, active against HeLa (cervical carcinoma), MCF-7 (breast adenocarcinoma), NCI-H460 (non-small-cell lung carcino-ma) and HepG2 (hepatocellular carcinoma) cell lines, was loaded in these nanocarriers, obtaining a high encapsulation efficiency of 98% ± 2.6%. The results indicate that the new magnetoliposomes can be suitable for dual cancer therapy (combined magnetic hyperthermia and chemotherapy).This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UIDB/04650/2020) and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by the European Fund of Regional Development (FEDER), COMPETE2020, and Portugal2020. J.M.R. acknowledges FCT, ESF (European Social Fund—North Portugal Regional Operational Program) and HCOP (Human Capital Operational Program) for a PhD grant (SFRH/BD/115844/2016)
Development of thermo-and pH-sensitive liposomal magnetic carriers for new potential antitumor thienopyridine derivatives
The development of stimuli-sensitive drug delivery systems is a very attractive area of current research in cancer therapy. The deep knowledge on the microenvironment of tumors has supported the progress of nanosystems’ ability for controlled and local fusion as well as drug release. Temperature and pH are two of the most promising triggers in the development of sensitive formulations to improve the efficacy of anticancer agents. Herein, magnetic liposomes with fusogenic sensitivity to pH and temperature were developed aiming at dual cancer therapy (by chemotherapy and magnetic hyperthermia). Magnetic nanoparticles of mixed calcium/manganese ferrite were synthesized by co-precipitation with citrate and by sol–gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy in transmission mode (STEM), and superconducting quantum interference device (SQUID). The citrate-stabilized nanoparticles showed a small-sized population (around 8 nm, determined by XRD) and suitable magnetic properties, with a low coercivity and high saturation magnetization (~54 emu/g). The nanoparticles were incorporated into liposomes of dipalmitoylphosphatidylcholine/cholesteryl hemisuccinate (DPPC:CHEMS) and of the same components with a PEGylated lipid (DPPC:CHEMS:DSPE-PEG), resulting in magnetoliposomes with sizes around 100 nm. Dynamic light scattering (DLS) and electrophoretic light scattering (ELS) measurements were performed to investigate the pH-sensitivity of the magnetoliposomes’ fusogenic ability. Two new antitumor thienopyridine derivatives were efficiently encapsulated in the magnetic liposomes and the drug delivery capability of the loaded nanosystems was evaluated, under different pH and temperature conditions.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UIDB/04650/2020) and through the research project PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by the European Fund of Regional Development (FEDER), COMPETE2020, and Portugal 2020. J.M.R. acknowledges FCT, ESF (European Social Fund—North Portugal Regional Operational Program) and HCOP (Human Capital Operational Program) for a PhD grant (SFRH/BD/115844/2016)
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