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1.
Plant Mol Biol ; 110(4-5): 365-384, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35648324

ABSTRACT

KEY MESSAGE: Heat stress (HS) under well-watered conditions was not detrimental to leaf photosynthesis or yield but modified the elevated CO2 response of photosynthesis and yield in two contrasting wheat cultivars. Climate change is increasing the frequency of extreme events such as heat waves, adversely affecting crop productivity. While positive impacts of elevated carbon dioxide (eCO2) on crop productivity are evident, the interactive effects of eCO2 and environmental stresses are still unclear. To investigate the interactive effects of elevated CO2 and heat stress (HS), we grew two contrasting wheat cultivars, early-maturing Scout and high-tillering Yitpi, under non-limiting water and nutrients at ambient (aCO2, 450 ppm) or elevated (eCO2, 650 ppm) CO2 and 22 °C in the glasshouse. Plants were exposed to two 3-day HS cycles at the vegetative (38.1 °C) and/or flowering (33.5 °C) stage. At aCO2, both wheat cultivars showed similar responses of photosynthesis and mesophyll conductance to temperature and produced similar grain yield. Relative to aCO2, eCO2 enhanced photosynthesis rate and reduced stomatal conductance and maximal carboxylation rate (Vcmax). During HS, high temperature stimulated photosynthesis at eCO2 in both cultivars, while eCO2 stimulated photosynthesis in Scout. Electron transport rate (Jmax) was unaffected by any treatment. eCO2 equally enhanced biomass and grain yield of both cultivars in control, but not HS, plants. HS reduced biomass and yield of Scout at eCO2. Yitpi, the cultivar with higher grain nitrogen, underwent a trade-off between grain yield and nitrogen. In conclusion, eCO2 improved photosynthesis of control and HS wheat, and improved biomass and grain yield of control plants only. Under well-watered conditions, HS was not detrimental to photosynthesis or growth but precluded a yield response to eCO2.


Subject(s)
Carbon Dioxide , Triticum , Biomass , Carbon Dioxide/pharmacology , Water , Photosynthesis/physiology , Heat-Shock Response , Edible Grain , Nitrogen/pharmacology
2.
Anal Chem ; 94(49): 17020-17030, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36414244

ABSTRACT

A novel electrochemical sensor was constructed based on an enzyme-mediated physiological reaction between neurotransmitter serotonin per-oxidation to reconstruct dual-molecule 4,4'-dimeric-serotonin self-assembled derivative, and the potential biomedical application of the multi-functional nano-platform was explored. Serotonin accelerated the catalytic activity to form a dual molecule at the C4 position and created phenolic radical-radical coupling intermediates in a peroxidase reaction system. Here, 4,4' dimeric-serotonin possessed the capability to recognize intermolecular interactions between amine groups. The excellent quenching effects on top of the gold surface electrode system archive logically inexpensive and straightforward analytical demands. In biochemical sensing analysis, the serotonin dimerization concept demonstrated a robust, low-cost, and highly sensitive immunosensor, presenting the potential of quantifying serotonin at point-of-care (POC) testing. The high-specificity serotonin electrochemical sensor had a limit of detection (LOD) of 0.9 nM in phosphate buffer and 1.4 nM in human serum samples and a linear range of 10 to 400 with a sensitivity of 2.0 × 10-2 nM. The bivalent 4,4'-dimer-serotonin interaction strategy provides a promising platform for serotonin biosensing with high specificity, sensitivity, selectivity, stability, and reproducibility. The self-assembling gold surface electrochemical system presents a new analytical method for explicitly detecting tiny neurotransmitter-responsive serotonin neuromolecules.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , Humans , Electrochemical Techniques/methods , Biosensing Techniques/methods , Serotonin/analysis , Reproducibility of Results , Immunoassay/methods , Gold/chemistry , Electrodes , Limit of Detection , Polymers , Neurotransmitter Agents/analysis , Metal Nanoparticles/chemistry
3.
Anal Bioanal Chem ; 414(10): 3205-3217, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34617153

ABSTRACT

Sensitive and selective determination of protein biomarkers with high accuracy often remains a great challenge due to their existence in the human body at an exceptionally low concentration level. Therefore, sensing mechanisms that are easy to use, simple, and capable of accurate quantification of analyte are still in development to detect biomarkers at a low concentration level. To meet this end, we demonstrated a methodology to detect thrombin in serum at low concentration levels using polypyrrole (PPy)-palladium (Pd)nanoparticle-based hybrid transducers using liposomes encapsulated redox marker as a label. The morphology of Ppy-Pd composites was characterized by scanning electron microscopy, and the hybrid structure provided excellent binding and detection platform for thrombin detection in both buffer and serum solutions. For quantitative measurement of thrombin in PBS and serum, the change in current was monitored using differential pulse voltammetry, and the calculated limit of quantification (LOQ) and limit of detection (LOD) for the linear segment (0.1-1000 nM of thrombin) were 1.1 pM and 0.3 pM, in serum, respectively. The sensors also exhibited good stability and excellent selectivity towards the detection of thrombin, and thus make it a strong candidate for adopting its sensing applications in biomarker detection technologies.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Nanocomposites , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Humans , Limit of Detection , Liposomes , Palladium/chemistry , Polymers/chemistry , Pyrroles/chemistry , Thrombin/chemistry
4.
J Exp Bot ; 72(8): 3235-3248, 2021 04 02.
Article in English | MEDLINE | ID: mdl-33484266

ABSTRACT

Optical films that alter light transmittance may reduce energy consumption in high-tech greenhouses, but their impact on crop physiology remains unclear. We compared the stomatal responses of Capsicum plants grown hydroponically under control glass (70% diffuse light) or the smart glass (SG) film ULR-80, which blocked >50% of short-wave radiation and ~9% of photosynthetically active radiation (PAR). SG had no significant effects on steady-state (gs) or maximal (gmax) stomatal conductance. In contrast, SG reduced stomatal pore size and sensitivity to exogenous abscisic acid (ABA), thereby increasing rates of leaf water loss, guard cell K+ and Cl- efflux, and Ca2+ influx. SG induced faster stomatal closing and opening rates on transition between low (100 µmol m-2 s-1) and high PAR (1500 µmol m-2 s-1), which compromised water use efficiency relative to control plants. The fraction of blue light (0% or 10%) did not affect gs in either treatment. Increased expression of stomatal closure and photoreceptor genes in epidermal peels of SG plants is consistent with fast stomatal responses to light changes. In conclusion, stomatal responses of Capsicum to SG were more affected by changes in light intensity than spectral quality, and re-engineering of the SG should maximize PAR transmission, and hence CO2 assimilation.


Subject(s)
Capsicum , Abscisic Acid , Light , Plant Leaves , Plant Stomata , Water
5.
Sens Actuators B Chem ; 329: 129214, 2021 Feb 15.
Article in English | MEDLINE | ID: mdl-36568647

ABSTRACT

This review reports the recent advances in surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) platforms for the diagnosis of infectious diseases. As observed through the recent infection outbreaks of COVID-19 worldwide, a timely diagnosis of the disease is critical for preventing the spread of a disease and to ensure epidemic preparedness. In this regard, an innovative point-of-care diagnostic method is essential. Recently, SERS-based assay platforms have received increasing attention in medical communities owing to their high sensitivity and multiplex detection capability. In contrast, LFAs provide a user-friendly and easily accessible sensing platform. Thus, the combination of LFAs with a SERS detection system provides a new diagnostic modality for accurate and rapid diagnoses of infectious diseases. In this context, we briefly discuss the recent application of LFA platforms for the POC diagnosis of SARS-CoV-2. Thereafter, we focus on the recent advances in SERS-based LFA platforms for the early diagnosis of infectious diseases and their applicability for the rapid diagnosis of SARS-CoV-2. Finally, the key issues that need to be addressed to accelerate the clinical translation of SERS-based LFA platforms from the research laboratory to the bedside are discussed.

6.
Mikrochim Acta ; 187(5): 277, 2020 04 20.
Article in English | MEDLINE | ID: mdl-32314063

ABSTRACT

MXene nanosheets of type Ti3C2Tx were modified with ß-hydroxybutyrate dehydrogenase and then used as a biosensor for amperometric sensing of ß-hydroxybutyrate. The MXene and the nanocomposite were characterized by X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The MXene has a layered structure and proved to be an excellent immobilization matrix providing good compatibility with the enzyme ß-hydroxybutyrate dehydrogenase. The MXene-based biosensor, best operated at a potential of - 0.35 V (vs. Ag/AgCl), displays a wide linear range (0.36 to 17.9 mM), a sensitivity of 0.480 µA mM-1 cm-2, and a low detection limit (45 µM). The biosensor was successfully applied to the determination of ß-hydroxybutyrate in (spiked) real serum samples. Graphical abstract Schematic representation of the synthesis and decoration of Mxene 2D sheets with ß-hydroxybutyrate dehydrogenase for the amperometric determination of ß-hydroxybutyric acid.


Subject(s)
3-Hydroxybutyric Acid/analysis , Carbon Compounds, Inorganic/chemistry , Hydroxybutyrate Dehydrogenase/chemistry , Nanocomposites/chemistry , Titanium/chemistry , 3-Hydroxybutyric Acid/metabolism , Biosensing Techniques , Electrochemical Techniques , Electrodes , Hydroxybutyrate Dehydrogenase/metabolism , Particle Size , Surface Properties
7.
Anal Chem ; 91(9): 5841-5849, 2019 05 07.
Article in English | MEDLINE | ID: mdl-30938982

ABSTRACT

Infectious pancreatic necrosis virus (IPNV) has been identified as a viral pathogen for many fish diseases that have become a huge hurdle for the growing fishing industry. Thus, in this work, we report a label-free impedance biosensor to quantify IPNV in real fish samples at point-of-care (POC) level. High specificity IPNV sensor with a detection limit of 2.69 TCID50/mL was achieved by conjugating IPNV antibodies to portable Au disk electrode chips using human heavy chain apoferritin (H-AFN) nanoprobes as a binding agent. H-AFN probes were bioengineered through PCR by incorporating pET-28b(+) resulting in 24 subunits of 6 × his-tag and protein-G units on its outer surface to increase the sensitivity of the IPNV detection. The biosensor surface modifications were characterized by differential pulse voltammetry (DPV) and EIS methods for each modification step. The proposed nanoprobe based sensor showed three-fold enhancement in charge transfer resistance toward IPNV detection in comparison with the traditional linker approach when measured in a group of similar virus molecules. The portable sensor exhibited a linear range of 100-10000 TCID50/mL and sensitivity of 5.40 × 10-4 TCID50/mL in real-fish samples. The performance of the proposed IPNV sensor was fully validated using an enzyme-linked immunosorbent assay (ELISA) technique with a sensitivity of 3.02 × 10-4 TCID50/mL. Results from H-AFN nanoprobe based IPNV sensor indicated high selectivity, sensitivity, and stability could be a promising platform for the detection of similar fish viruses and other biological molecules of interest.


Subject(s)
Apoferritins/chemistry , Biosensing Techniques/methods , Birnaviridae Infections/veterinary , Fish Diseases/diagnosis , Fishes/virology , Infectious pancreatic necrosis virus/isolation & purification , Nanoparticles/chemistry , Animals , Bioengineering , Birnaviridae Infections/diagnosis , Birnaviridae Infections/virology , Fish Diseases/virology
8.
J Exp Bot ; 70(21): 6447-6459, 2019 11 18.
Article in English | MEDLINE | ID: mdl-31504692

ABSTRACT

Hot days are becoming hotter and more frequent, threatening wheat yields worldwide. Developing wheat varieties ready for future climates calls for improved understanding of how elevated CO2 (eCO2) and heat stress (HS) interactively impact wheat yields. We grew a modern, high-yielding wheat cultivar (Scout) at ambient CO2 (aCO2, 419 µl l -1) or eCO2 (654 µl l-1) in a glasshouse maintained at 22/15 °C (day/night). Half of the plants were exposed to HS (40/24 °C) for 5 d at anthesis. In non-HS plants, eCO2 enhanced (+36%) CO2 assimilation rates (Asat) measured at growth CO2 despite down-regulation of photosynthetic capacity. HS reduced Asat (-42%) in aCO2- but not in eCO2-grown plants because eCO2 protected photosynthesis by increasing ribulose bisphosphate regeneration capacity and reducing photochemical damage under HS. eCO2 stimulated biomass (+35%) of all plants and grain yield (+30%) of non-HS plants only. Plant biomass initially decreased following HS but recovered at maturity due to late tillering. HS equally reduced grain yield (-40%) in aCO2- and eCO2-grown plants due to grain abortion and reduced grain filling. While eCO2 mitigated the negative impacts of HS at anthesis on wheat photosynthesis and biomass, grain yield was reduced by HS in both CO2 treatments.


Subject(s)
Carbon Dioxide/pharmacology , Edible Grain/growth & development , Heat-Shock Response/drug effects , Triticum/physiology , Acclimatization/drug effects , Biomass , Chlorophyll/metabolism , Edible Grain/drug effects , Fluorescence , Models, Biological , Photosynthesis/drug effects , Photosystem II Protein Complex/metabolism , Ribulose-Bisphosphate Carboxylase/metabolism , Temperature , Triticum/drug effects
9.
Inorg Chem ; 58(2): 1607-1620, 2019 Jan 22.
Article in English | MEDLINE | ID: mdl-30624909

ABSTRACT

We describe the synthesis and corresponding full characterization of the set of UiO-66 metal-organic frameworks (MOFs) with 1,4-benzenedicarboxylate (C6H4(COOH)2, hereafter H2BDC) and 1,4-naphthalenedicarboxylate (C10H6(COOH)2, hereafter H2NDC) mixed linkers with NDC contents of 0, 25, 50, and 100%. Their structural (powder X-ray diffraction, PXRD), adsorptive (N2, H2, and CO2), vibrational (IR/Raman), and thermal stability (thermogravimetric analysis, TGA) properties quantitatively correlate with the NDC content in the material. The UiO-66 phase topology is conserved at all relative fractions of BDC/NDC. The comparison between the synchrotron radiation PXRD and 77 K N2-adsorption isotherms obtained on the 50:50 BDC/NDC sample and on a mechanical mixture of the pure BDC and NDC samples univocally proves that in the mixed linkers of the MOFs the BDC and NDC linkers are shared in each MOF crystal, discarding the hypothesis of two independent phases, where each crystal contains only BDC or NDC linkers. The careful tuning of the NDC content opens a way for controlled alteration of the sorption properties of the resulting material as testified by the H2-adsorption experiments, showing that the relative ranking of the materials in H2 adsorption is different in different equilibrium-pressure ranges: at low pressures, 100NDC is the most efficient sample, while with increasing pressure, its relative performance progressively declines; at high pressures, the ranking follows the BDC content, reflecting the larger internal pore volume available in the MOFs with a higher fraction of smaller linkers. The H2-adsorption isotherms normalized by the sample Brunauer-Emmett-Teller specific surface area show, in the whole pressure range, that the surface-area-specific H2-adsorption capabilities in UiO-66 MOFs increase progressively with increasing NDC content. Density functional theory calculations, using the hybrid B3LYP exchange correlation functional and quadruple-ζ with four polarization functions (QZ4P) basis set, show that the interaction of H2 with the H2NDC linker results in an adsorption energy larger by about 15% with respect to that calculated for adsorption on the H2BDC linker.

11.
Sensors (Basel) ; 18(5)2018 Apr 24.
Article in English | MEDLINE | ID: mdl-29695134

ABSTRACT

Aflatoxin B1 (AFB1) is produced by the Aspergillus flavus and Aspergillus parasiticus group of fungi which is most hepatotoxic and hepatocarcinogenic and occurs as a contaminant in a variety of foods. AFB1 is mutagenic, teratogenic, and causes immunosuppression in animals and is mostly found in peanuts, corn, and food grains. Therefore, novel methodologies of sensitive and expedient strategy are often required to detect mycotoxins at the lowest level. Herein, we report an electrochemical impedance sensor that selectively detects AFB1 at the lowest level by utilizing polyaniline nanofibers (PANI) coated with gold (Au) nanoparticles composite based indium tin oxide (ITO) disk electrodes. The Au-PANI nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) spectroscopy, and electrochemical impedance spectroscopy (EIS). The composite electrode exhibited a 14-fold decrement in |Z|1Hz in comparison with the bare electrode. The Au-PANI acted as an effective sensing platform having high surface area, electrochemical conductivity, and biocompatibility which enabled greater loading deposits of capture antibodies. As a result, the presence of AFB1 was screened with high sensitivity and stability by monitoring the changes in impedance magnitude (|Z|) in the presence of a standard iron probe which was target specific and proportional to logarithmic AFB1 concentrations (CAFB1). The sensor exhibits a linear range 0.1 to 100 ng/mL with a detection limit (3) of 0.05 ng/mL and possesses good reproducibility and high selectivity against another fungal mycotoxin, Ochratoxin A (OTA). With regard to the practicability, the proposed sensor was successfully applied to spiked corn samples and proved excellent potential for AFB1 detection and development of point-of-care (POC) disease sensing applications.


Subject(s)
Electrodes , Aflatoxin B1 , Aniline Compounds , Biosensing Techniques , Electric Impedance , Electrochemical Techniques , Gold , Metal Nanoparticles , Nanofibers , Reproducibility of Results
12.
Inorg Chem ; 56(23): 14408-14425, 2017 Dec 04.
Article in English | MEDLINE | ID: mdl-28976176

ABSTRACT

We used Ni K-edge resonant-valence-to-core X-ray emission spectroscopy (RVtC-XES, also referred to as direct RIXS), an element-selective bulk-sensitive synchrotron-based technique, to investigate the electronic structure of the CPO-27-Ni metal-organic framework (MOF) upon molecular adsorption of significant molecular probes: H2O, CO, H2S, and NO. We compare RVtC-XES with UV-vis spectroscopy, and we show that the element selectivity of RVtC-XES is of strategic significance to observe the full set of d-d excitations in Ni2+, which are partially overshadowed by the low-energy π-π* transitions of the Ni ligands in standard diffuse-reflectance UV-vis experiments. Our combined RVtC-XES/UV-vis approach provides access to the whole set of d-d excitations, allowing us a complete discussion of the changes undergone by the electronic configuration of the Ni2+ sites hosted within the MOF upon molecular adsorption. The experimental data have been interpreted by multiplet ligand-field theory calculations based on Wannier orbitals. This study represents a step further in understanding the ability of the CPO-27-Ni MOFs in molecular sorption and separation applications.

13.
Plant Biotechnol J ; 14(7): 1589-603, 2016 07.
Article in English | MEDLINE | ID: mdl-26801007

ABSTRACT

Molecular changes elicited by plants in response to fungal attack and how this affects plant-pathogen interaction, including susceptibility or resistance, remain elusive. We studied the dynamics in root metabolism during compatible and incompatible interactions between chickpea and Fusarium oxysporum f. sp. ciceri (Foc), using quantitative label-free proteomics and NMR-based metabolomics. Results demonstrated differential expression of proteins and metabolites upon Foc inoculations in the resistant plants compared with the susceptible ones. Additionally, expression analysis of candidate genes supported the proteomic and metabolic variations in the chickpea roots upon Foc inoculation. In particular, we found that the resistant plants revealed significant increase in the carbon and nitrogen metabolism; generation of reactive oxygen species (ROS), lignification and phytoalexins. The levels of some of the pathogenesis-related proteins were significantly higher upon Foc inoculation in the resistant plant. Interestingly, results also exhibited the crucial role of altered Yang cycle, which contributed in different methylation reactions and unfolded protein response in the chickpea roots against Foc. Overall, the observed modulations in the metabolic flux as outcome of several orchestrated molecular events are determinant of plant's role in chickpea-Foc interactions.


Subject(s)
Cicer/microbiology , Fusarium/physiology , Metabolomics , Proteomics , Cicer/genetics , Cicer/metabolism , Disease Resistance , Host-Pathogen Interactions/genetics , Lignin/metabolism , Metabolic Networks and Pathways , Nuclear Magnetic Resonance, Biomolecular , Plant Roots/genetics , Plant Roots/metabolism , Reactive Oxygen Species/metabolism , Sesquiterpenes/metabolism , Phytoalexins
14.
J Am Chem Soc ; 137(10): 3466-9, 2015 Mar 18.
Article in English | MEDLINE | ID: mdl-25710124

ABSTRACT

An iron(II)-based metal-organic framework featuring coordinatively unsaturated redox-active metal cation sites, Fe2(dobdc) (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate), is shown to strongly bind nitric oxide at 298 K. Adsorption isotherms indicate an adsorption capacity greater than 16 wt %, corresponding to the adsorption of one NO molecule per iron center. Infrared, UV-vis, and Mössbauer spectroscopies, together with magnetic susceptibility data, confirm the strong binding is a result of electron transfer from the Fe(II) sites to form Fe(III)-NO(-) adducts. Consistent with these results, powder neutron diffraction experiments indicate that NO is bound to the iron centers of the framework with an Fe-NO separation of 1.77(1) Å and an Fe-N-O angle of 150.9(5)°. The nitric oxide-containing material, Fe2(NO)2(dobdc), steadily releases bound NO under humid conditions over the course of more than 10 days, suggesting it, and potential future iron(II)-based metal-organic frameworks, are good candidates for certain biomedical applications.


Subject(s)
Drug Liberation , Ferric Compounds/chemistry , Nitric Oxide/chemistry , Organometallic Compounds/chemistry , Adsorption , Models, Molecular , Molecular Conformation
15.
J Am Chem Soc ; 136(30): 10752-61, 2014 Jul 30.
Article in English | MEDLINE | ID: mdl-24999916

ABSTRACT

Six metal-organic frameworks of the M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) structure type are demonstrated to bind carbon monoxide reversibly and at high capacity. Infrared spectra indicate that, upon coordination of CO to the divalent metal cations lining the pores within these frameworks, the C-O stretching frequency is blue-shifted, consistent with nonclassical metal-CO interactions. Structure determinations reveal M-CO distances ranging from 2.09(2) Å for M = Ni to 2.49(1) Å for M = Zn and M-C-O angles ranging from 161.2(7)° for M = Mg to 176.9(6)° for M = Fe. Electronic structure calculations employing density functional theory (DFT) resulted in good agreement with the trends apparent in the infrared spectra and crystal structures. These results represent the first crystallographically characterized magnesium and zinc carbonyl compounds and the first high-spin manganese(II), iron(II), cobalt(II), and nickel(II) carbonyl species. Adsorption isotherms indicate reversible adsorption, with capacities for the Fe, Co, and Ni frameworks approaching one CO per metal cation site at 1 bar, corresponding to loadings as high as 6.0 mmol/g and 157 cm(3)/cm(3). The six frameworks display (negative) isosteric heats of CO adsorption ranging from 52.7 to 27.2 kJ/mol along the series Ni > Co > Fe > Mg > Mn > Zn, following the Irving-Williams stability order. The reversible CO binding suggests that these frameworks may be of utility for the separation of CO from various industrial gas mixtures, including CO/H2 and CO/N2. Selectivities determined from gas adsorption isotherm data using ideal adsorbed solution theory (IAST) over a range of gas compositions at 1 bar and 298 K indicate that all six M2(dobdc) frameworks could potentially be used as solid adsorbents to replace current cryogenic distillation technologies, with the choice of M dictating adsorbent regeneration energy and the level of purity of the resulting gases.

16.
Inorg Chem ; 53(18): 9509-15, 2014 Sep 15.
Article in English | MEDLINE | ID: mdl-25148242

ABSTRACT

A series of amine-functionalized mixed-linker metal-organic frameworks (MOFs) of idealized structural formula Zr6O4(OH)4(BDC)(6-6X)(ABDC)6X (where BDC = benzene-1,4-dicarboxylic acid, ABDC = 2-aminobenzene-1,4-dicarboxylic acid) has been prepared by solvothermal synthesis. The materials have been characterized by thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and Fourier transform infrared (FTIR) spectroscopy with the aim of elucidating the effect that varying the degrees of amine functionalization has on the stability (thermal and chemical) and porosity of the framework. This work includes the first application of ultraviolet-visible light (UV-vis) spectroscopy in the quantification of ABDC in mixed-linker MOFs.

17.
Acta Diabetol ; 61(7): 879-896, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38521818

ABSTRACT

AIMS: This study aims to develop an advanced model for the classification of Diabetic Macular Edema (DME) using deep learning techniques. Specifically, the objective is to introduce a novel architecture, SSCSAC-Net, that leverages self-supervised learning and category-selective attention mechanisms to improve the precision of DME classification. METHODS: The proposed SSCSAC-Net integrates self-supervised learning to effectively utilize unlabeled data for learning robust features related to DME. Additionally, it incorporates a category-specific attention mechanism and a domain-specific layer into the ResNet-152 base architecture. The model is trained using an ensemble of unsupervised and supervised learning techniques. Benchmark datasets are utilized for testing the model's performance, ensuring its robustness and generalizability across different data distributions. RESULTS: Evaluation of the SSCSAC-Net on multiple datasets demonstrates its superior performance compared to existing techniques. The model achieves high accuracy, precision, and recall rates, with an accuracy of 98.7%, precision of 98.6%, and recall of 98.8%. Furthermore, the incorporation of self-supervised learning reduces the dependency on extensive labeled data, making the solution more scalable and cost-effective. CONCLUSIONS: The proposed SSCSAC-Net represents a significant advancement in automated DME classification. By effectively using self-supervised learning and attention mechanisms, the model offers improved accuracy in identifying DME-related features within retinal images. Its robustness and generalizability across different datasets highlight its potential for clinical applications, providing a valuable tool for clinicians in diagnosing DME effectively.


Subject(s)
Deep Learning , Diabetic Retinopathy , Macular Edema , Humans , Macular Edema/classification , Macular Edema/diagnosis , Diabetic Retinopathy/classification , Diabetic Retinopathy/diagnosis , Supervised Machine Learning , Neural Networks, Computer
18.
Arthrosc Tech ; 13(4): 102911, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38690337

ABSTRACT

Lateral meniscus tears at the junction of the Wrisberg ligament and posterior horn are meniscocapsular injuries often seen with injury to the anterior cruciate ligament. Such lateral meniscus posterior horn lesions have been termed zip lesions. The lateral meniscus posterior horn is the major restraint for the pivot shift maneuver. Considering the morphology of condyles, lateral meniscus preservation and repair of unstable meniscocapsular posterior tear are needed to prevent future osteoarthritis. In this Technical Note, we aim to classify zip lesions of the posterior horn of the lateral meniscus. Zip lesions are located posteriorly and often are missed on magnetic resonance imaging and routine diagnostic arthroscopy. We recommend looking from the anteromedial portal and exploring the posterolateral compartment to identify hidden zip lesions, equivalent to medial-sided ramp lesions. We describe various all-inside techniques to repair these inaccessible tears.

19.
Arthrosc Tech ; 13(1): 102807, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38312875

ABSTRACT

The meniscus root is an attachment of the anterior and posterior horns of the meniscus onto the tibia, and its primary function is to prevent extrusion under axial load. Meniscus root tear constitutes 15% to 20% of meniscus tear. With the increased incidence of root tears being diagnosed commonly, many newer morphologic patterns of root tears have been detected, and the need to extend the conventional classification arises. At the same time, preserving the meniscus root necessitates novel techniques to repair this newer pattern. In this Technical Note, we describe the extended classification of root tears and arthroscopic repair techniques to achieve stable and secure fixation of meniscus roots.

20.
Chempluschem ; : e202400107, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38708570

ABSTRACT

Metal-organic frameworks (MOF) hold great promise for CO2 adsorption due to their high surface areas, tunable pore sizes, and the ability to modify their chemical properties to enhance CO2 affinity. MOFs tagged with functional groups either at linker or metal sites have shown improved CO2 uptake capacity and selectivity. This study focuses on investigating the potential of selective CO2 adsorption using amino functionalization of linker forming Ce-UiO-66. The physicochemical properties and characteristics of MOFs to determine the degree of amino functionalization and structural stability were examined using powder X-ray diffraction (PXRD), Fourier transformer infra-red (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and N2 porosimetry and specific surface area (BET). This work unveils a novel array of results on CO2, N2 and water vapour adsorption on Ce-UiO-66-NH2. The amino-functionalized Ce-UiO-66-NH2 shows 63 % higher CO2 uptake and 84 % higher CO2/N2 selectivity at 273 K and 1 bar over Ce-UiO-66. Ce-UiO-66-NH2 also shows excellent structural stability after gas and vapour sorption making Ce-UiO-66-NH2 potential adsorbent for CO2 capture.

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