Efficient Delivery with Mobile Agents
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Beyond Leaderboards: Tokenomics of Agentic Small Language Model Ensembles
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97 MATHEMATICS AND COMPUTING↗
Quantitative Literature Review (QLR): Did the Agent Read the Paper or Memorize It?
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97 MATHEMATICS AND COMPUTING↗
Porous Polymers as Universal Reversal Agents for Heparin Anticoagulants through an Inclusion–Sequestration Mechanism
Heparins are widely used anticoagulants for surgical procedures and extracorporeal therapies. However, all of them have bleeding risks. Protamine sulfate, the only clinically approved antidote for unfractionated heparin (UFH), has adverse effects. Moreover, protamine can only partially neutralize low-molecular-weight heparins (LMWHs) and is not effective for fondaparinux. In this report an inclusion–sequestration strategy for efficient neutralization of heparin anticoagulants by cationic porous supramolecular organic frameworks (SOFs) and porous organic polymers (POPs) is reported. Isothermal titration calorimetric and fluorescence experiments show strong binding affinities of these porous polymers toward heparins, whereas dynamic light scattering and zeta potential analysis confirm that the heparin sequences are adsorbed into the interior of the porous hosts. Activated partial thromboplastin time, anti-FXa, and thromboelastography assays indicate that their neutralization efficacies are higher than or as high as that of protamine for UFH and generally superior to protamine for LMWHs and fondaparinux, which is further confirmed by tail-transection model in mice and ex vivo aPTT or anti-FXa analysis in rats. Acute toxicity evaluations reveal that one of the SOFs displays outstanding biocompatibility. This work suggests that porous polymers can supply safe and rapid reversal of clinically used heparins, as protamine surrogates, providing an improved approach for their neutralization.
36 MATERIALS SCIENCE↗
Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents**
Abstract The acetonitrile‐solvated [(MeCN)Ni(C 2 F 5 ) 3 ] − was prepared in order to compare and contrast its reactivity with the known [(MeCN)Ni(CF 3 ) 3 ] − towards organic electrophiles. Both [(MeCN)Ni(CF 3 ) 3 ] − and [(MeCN)Ni(C 2 F 5 ) 3 ] − successfully react with aryl iodonium and diazonium salts as well as alkynyl iodonium salts to give fluoroalkylated organic products. Electrochemical analysis of [(MeCN)Ni II (C 2 F 5 ) 3 ] − suggests that, upon electro‐oxidation to [(MeCN) n Ni III (C 2 F 5 ) 3 ], reductive homolysis of a perfluoroethyl radical occurs, with the concomitant formation of [(MeCN) 2 Ni II (C 2 F 5 ) 2 ]. Catalytic C−H trifluoromethylations of electron‐rich arenes were successfully achieved using either [(MeCN)Ni(CF 3 ) 3 ] − or the related [Ni(CF 3 ) 4 ] 2− . Stoichiometric reactions of the solvated nickel complexes reveal that “ligandless” nickel is exceptionally capable of serving as reservoir of CF 3 groups under catalytically relevant conditions.
Shreiber, Scott T.↗
Solvated Nickel Complexes as Stoichiometric and Catalytic Perfluoroalkylation Agents**
The acetonitrile-solvated [(MeCN)Ni(C 2 F 5 ) 3 ] - was prepared in order to compare and contrast its reactivity with the known [(MeCN)Ni(CF 3 ) 3 ] - towards organic electrophiles. Both [(MeCN)Ni(CF 3 ) 3 ] - and [(MeCN)Ni(C 2 F 5 ) 3 ] - successfully react with aryl iodonium and diazonium salts as well as alkynyl iodonium salts to give fluoroalkylated organic products. Electrochemical analysis of [(MeCN)Ni II (C 2 F 5 ) 3 ] - suggests that, upon electro-oxidation to [(MeCN) n Ni III (C 2 F 5 ) 3 ], reductive homolysis of a perfluoroethyl radical occurs, with the concomitant formation of [(MeCN) 2 Ni II (C 2 F 5 ) 2 ]. Catalytic C-H trifluoromethylations of electron-rich arenes were successfully achieved using either [(MeCN)Ni(CF 3 ) 3 ] - or the related [Ni(CF 3 ) 4 ] 2- . Stoichiometric reactions of the solvated nickel complexes reveal that “ligandless” nickel is exceptionally capable of serving as reservoir of CF 3 groups under catalytically relevant conditions.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Thorium Bis‐Salophen Trimers as Anion Detectors and Binding Agents
Bis‐salophen ligands are the condensation product of a tetramine and a salicylaldehyde derivative. They feature two binding sites, both of which are tetradentate with mixed O/N donor atoms. Reaction with the ligand precursor and thorium nitrate tetrahydrate forms a 3:3 metal‐to‐ligand trimer with a ΔΔΔ‐chirality confirmed by X‐ray crystallography of a racemic single crystal. The structure has a pore in the center of the triangular structure measuring 6.22 Å at its narrowest point. This compound is air‐ and water‐stable as well as soluble in organic solvents. Here, this compound was screened with a series of tetrabutyl ammonium halide salts, and tetrabutylammonium (TBA) chloride showed the strongest binding to the complex. After the addition of 2 equivalents of TBACl, the complex and salt precipitate out of solution.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
In Vitro Metabolism and Stability of the Actinide Chelating Agent 3,4,3-LI(1,2-HOPO)
We report that the hydroxypyridinonate ligand 3,4,3-LI(1,2-HOPO) is currently under development for radionuclide chelation therapy. The preclinical characterization of this highly promising ligand comprised the evaluation of its in vitro properties, including microsomal, plasma, and gastrointestinal fluid stability, cytochrome P450 inhibition, plasma protein binding, and intestinal absorption using the Caco-2 cell line. When mixed with active human liver microsomes, no loss of parent compound was observed after 60 minutes, indicating compound stability in the presence of liver microsomal P450. At the tested concentrations, 3,4,3-LI(1,2-HOPO) did not significantly influence the activities of any of the cytochromal isoforms screened. Thus, 3,4,3-LI(1,2-HOPO) is unlikely to cause drug-drug interactions by inhibiting the metabolic clearance of co-administered drugs metabolized by these enzymes. Plasma protein binding assays revealed that the compound is protein-bound in dogs and less extensively in rats and humans. In the plasma stability study, the compound was stable after 1 h at 37°C in mouse, rat, dog, and human plasma samples. Finally, a bi-directional permeability assay demonstrated that 3,4,3-LI(1,2-HOPO) is not permeable across the Caco-2 monolayer, highlighting the need to further evaluate the effects of various compounds with known permeability enhancement properties on the permeability of the ligand in future studies.
60 APPLIED LIFE SCIENCES↗
Enhanced detection of paramagnetic fluorine-19 magnetic resonance imaging agents using zero echo time sequence and compressed sensing
Fluorine-19 ( 19 F) magnetic resonance imaging (MRI) is an emerging technique offering specific detection of labeled cells in vivo. Lengthy acquisition times and modest signal-to-noise ratio (SNR) makes three-dimensional spin-density–weighted 19 F imaging challenging. Recent advances in tracer paramagnetic metallo-perfluorocarbon (MPFC) nanoemulsion probes have shown multifold SNR improvements due to an accelerated 19 F T 1 relaxation rate and a commensurate gain in imaging speed and averages. However, 19 F T 2 -reduction and increased linewidth limit the amount of metal additive in MPFC probes, thus constraining the ultimate SNR. To overcome these barriers, we describe a compressed sampling (CS) scheme, implemented using a “zero” echo time (ZTE) sequence, with data reconstructed via a sparsity-promoting algorithm. Our CS-ZTE scheme acquires k-space data using an undersampled spherical radial pattern and signal averaging. Image reconstruction employs off-the-shelf sparse solvers to solve a joint total variation and -norm regularized least square problem. To evaluate CS-ZTE, we performed simulations and acquired 19 F MRI data at 11.7 T in phantoms and mice receiving MPFC-labeled dendritic cells. For MPFC-labeled cells in vivo, we show SNR gains of ~6.3 × with 8-fold undersampling. We show that this enhancement is due to three mechanisms including undersampling and commensurate increase in signal averaging in a fixed scan time, denoising attributes from the CS algorithm, and paramagnetic reduction of T 1 . Importantly, 19 F image intensity analyses yield accurate estimates of absolute quantification of 19 F spins. Overall, the CS-ZTE method using MPFC probes achieves ultrafast imaging, a substantial boost in detection sensitivity, accurate 19 F spin quantification, and minimal image artifacts.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Treatment of refractory oral lichen planus using direct antiviral agents in a patient with chronic hepatitis C: A case report
Abstract Oral lichen planus (OLP) is a chronic inflammatory and immunologically mediated mucocutaneous disease with a high prevalence in hepatitis C virus (HCV)‐infected patients. Interferon (IFN)‐free direct‐acting antiviral drugs (DAA) have been recommended for the treatment of patients with extrahepatic manifestations of HCV infection. Herein, we present the case of a 65‐year‐old woman who was diagnosed with OLP and chronic hepatitis C. She received DAA treatment with sofosbuvir (SOF) and ribavirin (RBA) at 75 years of age, which led to partial disappearance of the OLP and complete eradication of HCV. Thus, the patient was effectively treated without any major side effects.
Harada, Koji↗
Role of Selenium in CdZnTeSe as a Defect Engineering Agent
Cadmium zinc telluride (CdZnTe) with 10 atomic % Zn has been the material of choice for room-temperature semiconductor compact X- and gamma-ray detector applications for over three decades. Despite its commercial success as the most desirable room-temperature semiconductor radiation detection material, CdZnTe (CZT) suffers from a lack of compositional homogeneity on both the micro- and macroscales and the presence of high concentrations of performance-limiting defects such as subgrain boundary networks (dislocation walls) and secondary phases (Te-rich inclusions). Random distributions of these defects in the CZT matrix result in the spatial inhomogeneity of the material’s charge-transport properties. The recently discovered quaternary Cd x Zn 1-x Te 1-y Se y (CZTS) has experienced remarkable advances in its material properties, with highly reduced defects and higher compositional homogeneity. This book chapter focuses on the presence of performance-limiting defects in CZT that have thus far hindered the yield and cost of high-quality detectors and restricted their widespread deployment for a variety of potential applications, particularly for their use as large-volume gamma detectors, where the demands on material perfection are significantly greater. This chapter also provides an overview of the recent developments in the quaternary material CZTS, particularly the effects of selenium (Se) in the CZTS matrix on the defect engineering of the quaternary alloy material and the advancement of CZTS as a potential next-generation detector operable at room temperature.
Roy, Utpal N.↗
Novel anti-cancer agents: design, synthesis, biological activity, molecular docking, and MD simulations of 2, 3, 4, 5-tetrahydro-1H-pyrido-[4,3-b]indole derivatives
In the previous research, our group designed and synthesized 2,3,4,5-tetrahydro-1H-pyrido-[4,3-b] indoles, which showed high anti-tumor activity. In this study, a series of novel 2,3,4,5-tetrahydro-1H-pyrido-[4,3-b] indole derivatives were designed by introducing an alkyl or aralkyl and a sulfonyl group, which are considered as the pharmacophores of some antitumor drugs based on the combination principles, and synthesized. The antiproliferative activity of all the target compounds were evaluated against Hela, A549, HepG2, and MCF-7 cell lines using the MTT assay in vitro. The results were represented by IC{sub 50} values. All compounds showed moderate to excellent antiproliferative activity with IC{sub 50} values between 0 μM and 100 μM against cancer cells. The proliferations of Hela, A549, HepG2, and MCF-7 cell lines were inhibited in a dose-dependent manner, and the cytolytic activity was markedly inhibited at the same time. The IC{sub 50} values of intermediate 3 inhibited against Hela, A549, HepG2, and MCF-7 cell lines were 52.75, 50.30, 60.31, and 54.39 μM, respectively, which were higher than the new compounds that we expected. The compounds 4a–4d bearing sulfonyl, substituted by electron donating group, showed moderate to significant antiproliferative activity, in which compound 4c was the best with the IC{sub 50} values of 13.71, 9.42, 15.06, and 14.77 μM, and these results suggested that the introduction of sulfonyl could increase the antiproliferative activity of 2,3,4,5-tetrahydro-1H-pyrido-[4,3-b]indole. Compounds 4e–4g bearing alkyl, phenyl, and arylated alkyl produced good antiproliferative activity and the IC{sub 50} value of 4g was lower than 30 μM. The target compounds were more potent against A549 compared to the other three cell lines. Molecular docking studies revealed the binding orientations of all the synthesized compounds in the active site of c-Met. Moreover, molecular dynamics simulations have been performed to evaluate the binding stabilities between the synthesized compounds and their receptors.
60 APPLIED LIFE SCIENCES↗
Syntheses and in silico pharmacokinetic predictions of glycosylhydrazinyl-pyrazolo[1,5-c]pyrimidines and pyrazolo[1,5-c]triazolo[4,3-a]pyrimidines as anti-proliferative agents
New glycosylhydrazinyl-pyrazolo[1,5-c]pyrimidines were synthesized by the reaction of respective 5-aryl-7-hydrazino-2-phenylpyrazolo[1,5-c]pyrimidines (1a-d) with glucose, galactose, and xylose in ethanol. Their glycopyranosyl structures were reasoned to be in chair conformations and each have hydrazine moiety in the β-configuration. Also, pyrazolo[1,5-c]triazolo[4,3-a]pyrimidines derivatives were synthesized by the reaction of 1a-d with benzoic acid in the presence of phosphorousoxy chloride or by the reaction with benzaldehyde derivatives followed by cyclization in the presence of bromine. All structures of the compounds were confirmed from their IR, {sup 1}H, {sup 13}C, DPET-135°, {sup 1}H-{sup 1}H COSY, {sup 1}H-{sup 13}C HMQC, {sup 13}C-{sup 1}H HMBC spectra and microanalysis. The synthesized compounds showed inhibition of proliferation of MCF-7 human breast cancer cells with IC{sub 50} values ranging from 0.56 to 8.86 µg/ml. Some of the most active compounds showed acceptable predicted pharmacokinetics and drug-likeness properties. .
60 APPLIED LIFE SCIENCES↗
Structure-activity relationships of novel dithiocarbamates containing α,β-unsaturated ketone fragment as potent anticancer agents
Based on the structure of novel lead compound 8 discovered by our group, systematic structural modification was carried out. A series of compound 8’s derivatives were synthesized and evaluated for their activities against human non-small cell lung cancer cell line H460. Among them, twelve compounds showed significant proliferation inhibition activities with IC{sub 50} values <1 μM and compound 12r was the most potent one. Further study on compound 12r revealed that it has significant inhibitory effect on the growth of eight kinds of cancer cell lines with IC{sub 50} values <1 μM. Especially for cell lines A375 and HCT116, the IC{sub 50} values of 12r achieved 63 nM and 66 nM, respectively. Meanwhile, our research results also revealed the following structure-activity relationships: (a) different substitutions on the benzene ring or heteroaromatic rings greatly effect on the activity; (b) the presence of α,β-unsaturated ketone fragment is favorable for the activity; (c) the receptor cavity binding with amine moiety might be a relatively small hydrophobic cavity. These results will be valuable for the further development of this novel kind of dithiocarbamates.
60 APPLIED LIFE SCIENCES↗
Synthesis and biological evaluation of novel disulfides incorporating 1,3,4-thiadiazole scaffold as promising antitumor agents
In the present study, fourteen 2,5-disubstituted 1,3,4-thiadiazole derivatives containing disulfide group were prepared. The resulting compounds 7a–7n were identified by IR, NMR, MS, and elemental analysis. Their antiproliferative properties in vitro were studied employing standard CCK-8 assay against SMMC-7721, MCF-7, and A549 lines. Bioassay indicated that some compounds showed stronger antitumor effects than reference drugs PX-12 and 5-fluorouracil. Among these screened compounds, compound 7h showed excellent biological activities in inhibiting SMMC-7721 cell proliferation with IC{sub 50} at 1.93 ± 0.08 μM. Compounds 7k and 7i manifested highly effective growth inhibitory activity versus MCF-7 cells, with IC{sub 50} at 3.04 ± 0.09 and 3.54 ± 0.17 μM, respectively. For A549 cells, compound 7m was found to have the highest antitumor potency with IC{sub 50} at 3.67 ± 0.13 μM.
60 APPLIED LIFE SCIENCES↗