Selection Experiments Research Articles

Identification of Macrocyclic Peptide Families from Combinatorial Libraries Containing Noncanonical Amino Acids Using Cheminformatics and Bioinformatics Inspired Clustering.

In the past decade, macrocyclic peptides gained increasing interest as a new therapeutic modality to tackle intracellular and extracellular therapeutic targets that had been previously classified as "undruggable". Several technological advances have made discovering macrocyclic peptides against these targets possible: 1) the inclusion of noncanonical amino acids (NCAAs) into mRNA display, 2) increased availability of next generation sequencing (NGS), and 3) improvements in rapid peptide synthesis platforms. This type of directed-evolution based screening can produce large numbers of potential hit sequences given that DNA sequencing is the functional output of this platform. The current standard for selecting hit peptides from these selections for downstream follow-up relies on the frequency counting and sorting of unique peptide sequences which can result in the generation of false negatives due to technical reasons including low translation efficiency or other experimental factors. To overcome our inability to detect weakly enriched peptide sequences among our large data sets, we wanted to develop a clustering method that would enable the identification of peptide families. Unfortunately, utilizing traditional clustering algorithms, such as ClustalW, is not possible for this technology due to the incorporation of NCAAs in these libraries. Therefore, we developed a new atomistic clustering method with a Pairwise Aligned Peptide (PAP) chemical similarity metric to perform sequence alignments and identify macrocyclic peptide families. With this method, low enriched peptides, including isolated sequences (singletons), can now be clustered into families providing a comprehensive analysis of NGS data resulting from macrocycle discovery selections. Additionally, upon identification of a hit peptide with the desired activity, this clustering algorithm can be used to identify derivatives from the initial data set for structure-activity relationship (SAR) analysis without requiring additional selection experiments.

Computational biogeographic distribution of the fall armyworm (Spodoptera frugiperda J.E. Smith) moth in eastern Africa

The fall armyworm (FAW), Spodoptera frugiperda J.E. Smith, has caused massive maize losses since its attack on the African continent in 2016, particularly in east Africa. In this study, we predicted the spatial distribution (established habitat) of FAW in five east African countries viz., Kenya, Tanzania, Rwanda, Uganda, and Ethiopia. We used FAW occurrence observations for three years i.e., 2018, 2019, and 2020, the maximum entropy (MaxEnt) model, and bioclimatic, land surface temperature (LST), solar radiation, wind speed, elevation, and landscape structure data (i.e., land use and land cover and maize harvested area) as explanatory variables. The explanatory variables were used as inputs into a variable selection experiment to select the least correlated ones that were then used to predict FAW establishment, i.e., suitability areas (very low suitability – very high suitability). The shared socio-economic pathways, SSP2-4.5 and SSP5-8.5 for the years 2030 and 2050 were used to predict the effect of future climate scenarios on FAW establishment. The results demonstrated that FAW establishment areas in eastern Africa were based on the model strength and true performance (area under the curve: AUC = 0.87), but not randomly. Moreover, ∼27% of eastern Africa is currently at risk of FAW establishment. Predicted FAW risk areas are expected to increase to ∼29% (using each of the SSP2-4.5 and SSP5-8.5 scenarios) in the year 2030, and to ∼38% (using SSP2-4.5) and ∼35% (using SSP5-8.5) in the year 2050 climate scenarios. The LULC, particularly croplands and maize harvested area, together with temperature and precipitation bioclimatic variables provided the highest permutation importance in determining the occurrence and establishment of the pest in eastern Africa. Specifically, the study revealed that FAW was sensitive to isothermality (Bio3) rather than being sensitive to a single temperature value in the year. FAW preference ranges of temperature, precipitation, elevation, and maize harvested area were observed, implying the establishment of a once exotic pest in critical maize production regions in eastern Africa. It is recommended that future studies should thus embed the present study's modeling results into a dynamic platform that provides near-real-time predictions of FAW spatial occurrence and risk at the farm scale.

Using machine learning to realize genetic site screening and genomic prediction of productive traits in pigs.

Genomic prediction, which is based on solving linear mixed-model (LMM) equations, is the most popular method for predicting breeding values or phenotypic performance for economic traits in livestock. With the need to further improve the performance of genomic prediction, nonlinear methods have been considered as an alternative and promising approach. The excellent ability to predict phenotypes in animal husbandry has been demonstrated by machine learning (ML) approaches, which have been rapidly developed. To investigate the feasibility and reliability of implementing genomic prediction using nonlinear models, the performances of genomic predictions for pig productive traits using the linear genomic selection model and nonlinear machine learning models were compared. Then, to reduce the high-dimensional features of genome sequence data, different machine learning algorithms, including the random forest (RF), support vector machine (SVM), extreme gradient boosting (XGBoost) and convolutional neural network (CNN) algorithms, were used to perform genomic feature selection as well as genomic prediction on reduced feature genome data. All of the analyses were processed on two real pig datasets: the published PIC pig dataset and a dataset comprising data from a national pig nucleus herd in Chifeng, North China. Overall, the accuracies of predicted phenotypic performance for traits T1, T2, T3 and T5 in the PIC dataset and average daily gain (ADG) in the Chifeng dataset were higher using the ML methods than the LMM method, while those for trait T4 in the PIC dataset and total number of piglets born (TNB) in the Chifeng dataset were slightly lower using the ML methods than the LMM method. Among all the different ML algorithms, SVM was the most appropriate for genomic prediction. For the genomic feature selection experiment, the most stable and most accurate results across different algorithms were achieved using XGBoost in combination with the SVM algorithm. Through feature selection, the number of genomic markers can be reduced to 1 in 20, while the predictive performance on some traits can even be improved compared to using the full genome data. Finally, we developed a new tool that can be used to execute combined XGBoost and SVM algorithms to realize genomic feature selection and phenotypic prediction.

Women Experts and Gender Bias in Political Media.

Widely held gender stereotypes present obstacles for women experts, who are generally evaluated less positively than equally qualified men across a range of fields. While audiences may view women as better equipped to handle certain feminine-stereotyped issues, Role Congruency Theory suggests that expert authority in politics may be incongruent with traditional feminine gender roles, leading to a subsequent backlash. Building upon the latter theory, I hypothesize that when cued to consider the expertise of a news source, the (in)congruence of gender-stereotyped roles will activate gender biases which increase the gap in evaluations and trust of women and men. Using selection experiments, I assess the relationship between domain-relevant expertise and gender biases across a range of gender-stereotyped issues. I find that women experts are rewarded less for additional expertise and punished more severely for a lack of expertise, exacerbating gender-based biases relative to the control. I find that this pattern is consistent across both masculine- and feminine-stereotyped issues, including issues that disproportionately impact women, such as women's health care and the gender wage gap. The addition of competing partisan cues, however, overwhelms the influence of gender. The normative implications suggest women in the media often face an uphill battle to advocate for their interests on key issues that affect them even when they may have more direct relevant experience in addition to their qualifications.

Improved selectivity of molecularly imprinted polymers based on the synergistic action of hydrogen bond and electrostatic interaction.

Based on the synergistic action of hydrogen bond and electrostatic interaction, provided by methacrylic acid and 2-aminoethyl ester hydrochloride (FM2), respectively, novel molecularly imprinted polymers (SA-MIPs) were designed to improve its selective recognition ability. Diclofenac sodium (DFC) was chosen as the template molecule of this study. The interaction and their recognition sites between two functional monomers and templates were confirmed by nuclear magnetic resonance hydrogen spectroscopy. Because of the synergistic action of hydrogen bond and electrostatic interaction, the imprinting factor (IF) of SA-MIPs (IF = 2.26) is superior to the corresponding monofunctional monomer imprinting materials (IF = 1.52, 1.20) and the materials using two functional monomers with an only single type of interaction (IF = 1.54, 1.75). The results of selective adsorption experiments indicate that the selective recognition ability of SA-MIPs is significantly better than that of the other four MIPs, and the difference in selectivity coefficient for methyl orange is the largest between SA-MIPs and the MIPs only using FM2, which is about 70 times. In addition, x-ray photoelectron spectroscopy was used to verify the interaction between SA-MIPs and the template. This work and its explanation of the interaction mechanism at the molecular level will be helpful for the rational design of novel MIPs with higher selectivity. Besides, SA-MIPs have good adsorption performance (37.75 mg/g) for DFC in aqueous solutions, which could be used as potential adsorption materials for the effective removal of DFC in the aquatic environment.

Up-regulation of resident chromosomal fosB gene expression: a novel mechanism of acquired fosfomycin resistance in MRSA.

This study investigated fosfomycin susceptibility and mechanisms of resistance in a collection of 99 Staphylococcus aureus isolated from cases of hospital-acquired pneumonia, previously collected from a multicentre survey carried out in Italy. Fosfomycin susceptibility was tested by reference agar dilution. Bioinformatic and gene expression analysis, mutant selection experiments and WGS were executed to characterize fosfomycin resistance mechanisms. Fosfomycin resistance rates were 0% (0 of 35) among MSSA and 22% (14 of 64) among MRSA, with no evidence of clonal expansion. Resistance mechanisms were putatively identified in 8 of the 14 resistant strains, including: (i) chromosomal mutations causing loss of function of the UhpT transporter; (ii) overexpression of the gene encoding the Tet38 efflux pump; and (iii) overexpression of a fosB gene encoding a fosfomycin-inactivating enzyme, which was found to be resident in the chromosome of several S. aureus lineages but not always associated with fosfomycin resistance. The latter mechanism, which had not been previously described and was confirmed by results of in vitro mutant selection experiments, was associated in two cases with transposition of an IS1182 element upstream of the chromosomal fosB gene, apparently providing an additional promoter. This study showed that some S. aureus clonal lineages carry a resident chromosomal fosB gene and can evolve to fosfomycin resistance by overexpression of this gene.

Host Size Selection in the Ectoparasite Tachaea chinensis (Isopoda: Corallanidae) under Laboratory Conditions.

Tachaea chinensis is a temporary ectoparasite infesting freshwater shrimps and prawns in eastern Asia. This study investigated the host size selection by T. chinensis across common freshwater shrimps under laboratory conditions. A total of 70 isopods were allowed to select between host shrimps of different size and different species in pairwise selection experiments. In treatments involving different sizes of the same host species, T. chinensis tended to select the medium host option in all of the four treatments. Similarly, T. chinensis demonstrated greater preference towards medium host (90%) when provided with mixed host options (medium Palaemon paucidens vs small Neocaridina spp.). However, despite the increase in the infestation proportion on medium Neocaridina spp., the isopod significantly selected the small P. paucidens when provided with a choice between medium Neocaridina spp. and small P. paucidens. In manca stage (1 day after hatch) T. chinensis treatment, the isopods showed no specific preference between large and medium Neocaridina spp. These results suggest that T. chinensis is likely to show size specificity according to the developmental stage, a size specificity that ultimately ensures adequate space for isopods' growth while maintaining a minimum risk of predation.

Genomic Evolution in Pseudomonas fluorescens as a Result of Gradual Temperature Changes

As climate change continues to affect global temperatures, organisms will need to not only adapt but evolve to survive the changing climate conditions. Temperature selection experiments were performed on Pseudomonas fluorescens to select for growth at lower temperatures. The P. fluorescens temperature selection experiment selected for cells that can grow at a new minimum temperature which is over 20˚C lower than the optimal growth temperature (25-30˚C). Previous experiments established the low end of P. fluorescens’s growth temperature as 4˚C. The genomes of the newly selected and reference strains of P. fluorescens were sent for sequencing, and the results showed differences in protein sequence between the two strains. This experiment is a model for evolution as a result of gradual temperature change (similar to climate change) over generations, and the resulting genomic changes recorded show which protein families could evolve as an organism adapts to a gradually changing temperature.

Embryo survival and fertility differ in lines divergently selected for birth weight homogeneity in mice.

The selection of animals for lower environment sensitivity around the optimum trait value can also provide benefits in productivity and welfare. A divergent selection experiment for birth weight environmental variability in mice was successfully conducted over 17 generations. Animals from low variability selected line (L-line) were more robust by having a higher litter size and survival at weaning in a common breeding environment, than those from high variability line (H-line). The objective of this study was to analyze the differences between those divergently selected lines for embryo and fetal survival and for fertility and prolificacy rate. To study embryo survival and ovulation rate, a total of 98 females (34 H-line and 50 L-line) were studied in four generations of the divergent experiment. To analyze fetal survival and fertility rate, 378 female mice (138 H-line and 240 L-line) in 10 generations or the divergent experiment were studied. Ultrasound scans were performed at day 14 of gestation to establish the number of total fetal and the embryo absorptions. Mortality was addressed as the difference between litter size at birth and the number of fetuses at 14 days of gestation. The number of pregnant females in the first 3 days after mating was used to measure fertility. A linear model was also fitted to analyze embryo mortality, litter size, and the number of embryos at 14 days of gestation. A categorical model was then used to study fertility, including line, generation, and its interaction as effects. Despite the fact that there were no significant differences in the ovulation rate, litter size at birth was significantly higher in the L-line than in the H-line (9.82 vs. 8.36 pups, p < 0.001). Moreover, embryo mortality was significantly lower in the L-line than in the H-line (1.39 vs. 2.87 fetuses, p < 0.001). L-line females were more fertile (53.49% vs. 23.26% for the H-line). According to these results, the line selected for low environmental variance would be preferable for robustness and animal welfare.

Provenance of multi-stage volcanic ash recorded in the Late Carboniferous coal in the Jungar Coalfield, North China, and their contribution to the enrichment of critical metals in the coal

The origins of partings within the Late Carboniferous No. 6 coal in the Jungar Coalfield, North China, and their relationship to the enrichment of critical metals in the coal, is poorly understood. This study combines UPb ages and LuHf isotope data of zircon, whole-rock geochemistry, LA–ICP–MS elemental mapping, and selective chemical extraction experiments to investigate the provenance of the partings and the occurrence mode of critical metals in the partings collected from the exploration area in the northwest of the Jungar Coalfield. It was found that the zircons in the kaolinite-dominant partings yielded a single age group of ca. 300 Ma at the latest Carboniferous (Gzhelian), indicating that the partings are alteration products of air-fall volcanic ash (tonsteins). The zircons are characterized by negative εHf(t) values and a continental arc tectonic setting, suggesting a genetic connection between the volcanic ash and the Late Paleozoic continental arc that existed in the Inner Mongolia Paleo-Uplift, related to the southward subduction of the Paleo-Asian oceanic plate beneath the northern margin of the North China Block. During the devitrification of volcanic glasses to kaolinite in the mires, the incompatible elements, such as Nb, Ta, Zr, Hf, and rare earth elements (REEs and Y, REY), preserved in the volcanic glasses were leached out as they are incompatible with the crystal lattice of kaolinite. Niobium and Ta, similar to Ti in ionic radii, were preferentially incorporated into fine-grained Ti oxides as reprecipitated products in the alteration process of volcanic ash. The enrichment of Nb, Ta, and Ti in organic matter in the tonsteins suggests that they have some mobility during alteration of volcanic ash and could be, to some extent, transported into the enclosing peats. Zirconium, Hf, and REY were fixed by organic matter admixed with the volcanic ash after their deposition in the mires. Meanwhile, they could also be transported into the enclosing peats, as no secondary minerals formed could substantially retain them. Although Li and Ga were able to be incorporated into the crystal lattice of kaolinite during their crystallization, they could also be transported into the enclosing peats due to their fluid-mobile nature. Both the leaching of a voluminous amount of volcanic ash contacting with the peats and the input of the volcanic ash as an admixture into the peats contributed to the enrichment of critical metals in the Late Carboniferous coal in the Jungar Coalfield.

Experimental test of the influence of light availability on the evolution of eye size and behaviour in Daphnia.

There exists extensive variation in eye size. Much work has provided a connection between light availability and differences in eye size across taxa. Experimental tests of the role of the light environment on the evolution of eye size are lacking. Here, we performed a selection experiment that examined the influence of light availability on shifts in eye size and the connection between eye size and phototactic (anti-predator) behaviour in Daphnia. We set-up replicate experimental populations of Daphnia, repeatedly evaluated phenotypic shifts in eye size during the ~50-day experiment, and performed a common garden experiment at the end of the experiment to test for evolutionary shifts in eye size and behaviour. Our phenotypic analyses showed that eye size rapidly diverged between the light treatments; relative eye size was consistently larger in the low versus high light treatments. Selection on eye size was also modified by variation in density as increases in Daphnia density favoured a larger eye. However, we did not observe differences in eye size between the light treatments following two generations of common garden rearing at the end of the experiment. We instead observed strong shifts in anti-predator behaviour. Daphnia from the low light treatment exhibited decreased phototactic responses to light. Our results show that decreased light relaxes selection on anti-predator behaviour. Such trends provide new insights into selection on eye size and behaviour.

&lt;i&gt;Apis mellifera&lt;/i&gt; L. Stock Varied in Apple Pollen Foraging Preference

Apis mellifera L. colonies were evaluated to explore the apple foraging preference for effective pollination. In 2017, colony G2 showed highest preference for apple pollen loads (18.78%), while L3 recorded lowest apple pollen load (9.89%). On the basis of preference, queens from H2, L3, and G2 were produced to raise progenies for further multiplication and evaluation in 2018 and similar selection experiment was conducted in 2019 and 2020. In 2020 significant number of foragers were conditioned to apple flowers from the colony selected during the year 2019, thus indicating that A. mellifera strains multiplied from the colony showing higher apple pollen foraging preference was carried over to next generation and can be exploited to produce progenies to improve pollen hoarding trait with the help of continuous selection and breeding process.

Cr(VI) anion-imprinted polymer synthesized on mesoporous silicon via synergistic action of bifunctional monomers for precise identification and separation of Cr(VI) from aqueous solution by fixed-bed adsorption.

The novel Cr(VI) anion-imprinted polymer (Cr(VI)-IIP) was prepared by a surface imprinting technique with bifunctional monomers pre-assembly system based on mesoporous silicon (SBA-15). The synthesized Cr(VI)-IIP was characterized by Fourier transmission infrared spectra (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray powder diffractometer, N2 adsorption-desorption and thermogravimetric analysis (TGA), proving to be with a highly ordered mesoporous structure, as well as favorable thermal stability. The saturated adsorption amount was 96.32 mg/g, which was 2.7 times higher than that of non-imprinted polymer (NIP). Kinetic experiments showed that the adsorption equilibrium state was obtained within 70 min. In addition, in the selectivity experiments, Cr(VI)-IIP exhibited strong specific recognition ability for Cr(VI) and could realize the separation of Cr(VI) and Cr(III) from an aqueous solution. The dynamic adsorption experiments exhibited that the dynamic adsorption efficiency of Cr(VI)-IIP was as high as 71.57%. Meanwhile, the dynamic regeneration experiments showed that the adsorption amount of Cr(VI)-IIP did not decrease significantly after repeating for five times. All of the findings suggested that Cr(VI)-IIP could achieve precise identification as well as efficient separation of Cr(VI) from aqueous solution.

DEL-Dock: Molecular Docking-Enabled Modeling of DNA-Encoded Libraries.

DNA-encoded library (DEL) technology has enabled significant advances in hit identification by enabling efficient testing of combinatorially generated molecular libraries. DEL screens measure protein binding affinity though sequencing reads of molecules tagged with unique DNA barcodes that survive a series of selection experiments. Computational models have been deployed to learn the latent binding affinities that are correlated to the sequenced count data; however, this correlation is often obfuscated by various sources of noise introduced in its complicated data-generation process. In order to denoise DEL count data and screen for molecules with good binding affinity, computational models require the correct assumptions in their modeling structure to capture the correct signals underlying the data. Recent advances in DEL models have focused on probabilistic formulations of count data, but existing approaches have thus far been limited to only utilizing 2-D molecule-level representations. We introduce a new paradigm, DEL-Dock, that combines ligand-based descriptors with 3-D spatial information from docked protein-ligand complexes. 3-D spatial information allows our model to learn over the actual binding modality rather than using only structure-based information of the ligand. We show that our model is capable of effectively denoising DEL count data to predict molecule enrichment scores that are better correlated with experimental binding affinity measurements compared to prior works. Moreover, by learning over a collection of docked poses we demonstrate that our model, trained only on DEL data, implicitly learns to perform good docking pose selection without requiring external supervision from expensive-to-source protein crystal structures.

Acceleration of indirect detection 195Pt solid-state NMR experiments by sideband selective excitation or alternative indirect sampling schemes

The measurement of the of chemical shift (CS) tensors via solid-state NMR (ssNMR) spectroscopy has proven to be a powerful probe of structure for organic molecules, biomolecules, and inorganic materials. However, when measuring the NMR spectra of heavy spin-1/2 isotopes the chemical shift anisotropy (CSA) is commonly on the order of thousands of parts per million, which makes acquisition of NMR spectra difficult due to the low NMR sensitivity imposed by the breadth of the signals and challenges in uniformly exciting the NMR spectrum. We have recently shown that complete 195Pt NMR spectra could be rapidly measured by using 195Pt saturation or excitation selective long pulses (SLP) with multiple rotor-cycle durations and RF fields less than 50 kHz into 1H{195Pt} or 1H-31P{195Pt} PE S-RESPDOR, TONE D-HMQC-4, J-resolved, and J-HMQC pulse sequences. The SLP only provide signal or dephasing when they are applied on resonance with a spinning sideband. The magic angle spinning 195Pt NMR spectrum is reconstructed in the sideband selective NMR experiments by acquiring 1D NMR spectra at variable 195Pt pulse offsets. In this work, we present a detailed investigation of the specific pulse conditions required for the ideal performance of sideband selective experiments. Sideband selective experiments are shown to be able to accurately reproduce MAS NMR spectra with minimal distortions of relative sideband intensities. It is also demonstrated that a 195Pt NMR spectrum indirectly detected with HMQC can be rapidly obtained by acquiring a single rotor cycle of indirect dimension evolution points. We dub this method One Rotor Cycle of Acquisition (ORCA) HMQC. Sideband selective experiments and ORCA HMQC experiments are shown to provide a one order of magnitude improvement in experiment times as compared to conventional wideline HMQC experiments.

Evolution Under Dietary Restriction Increases Reproduction at the Cost of Decreased Somatic Growth.

Dietary restriction (DR) is cited as the most reliable means of extending life span in a wide range of taxa, yet the evolutionary basis of the DR effect on life span remains unclear. The resource reallocation hypothesis proposes that the longevity-extending response of DR is adaptive and stems from the reallocation of resources from reproduction to somatic maintenance under food-limited conditions. However, if DR continues for multiple generations, such a response becomes maladaptive, and genotypes with higher fecundity should be selectively favored over genotypes with longer longevity. To test this prediction, we exposed replicate populations of the rotifer Brachionus dorcas, a model organism for aging and experimental evolution studies, to DR and ad-libitum (AL) diets for 100 days. During the selection experiment, AL-selected populations showed higher growth rates and mictic ratios than DR-selected populations. After approximately 27 asexual generations of selection, populations with a DR selection history had a higher net reproductive rate but lower body volume and ingestion rate in the absence of survival costs than populations with an AL selection history when they were assayed on an AL diet. Our results are inconsistent with the prediction that evolution on sustained DR increases reproduction and reduces life span, and show for the first time that sustained DR selects for clones with higher energy investment in reproduction but lower investment in somatic growth.

Experimental and theoretical investigation on enhanced selective recognition of methamphetamine by customized adsorbent

Development of a superior water pretreatment for monitoring the psychoactive substances in urban is requisite. Herein, a novel adsorbent with selective adsorption capacity for methamphetamine (MAMP) has been successfully designed through deep eutectic solvents (DES) as a modifier was used to regulate magnetic reduced graphene oxide/ZIF-67 (MGZ) composites. The DES, named as Choline chloride/Levulinic acid (LA), with high affinity towards MAMP, was screened by density functional theory (DFT). The DESs regulated MGZ to synthesize DES/MGZ, and the adsorption performances of diverse DES/MGZ were investigated by contrast experiment. The selective adsorption performances were investigated by selective experiment with multiple compounds. The MAMP adsorption amount of LA/MGZ was 365.96 μg g−1, and enhanced 82.98% than MGZ (200.67 μg g−1). The characteristic of pH-dependent occurred on the MAMP adsorption by LA/MGZ was attributed to the exfoliation of highly oxidized debris promote H-bonding and π-π interactions between LA/MGZ and MAMP. Theoretical calculations in combination with characterization analyses illustrated the efficient recognition of LA toward MAMP was mainly dependent on the H-bonding interactions between carboxyl groups of LA and the -NH of MAMP, as well as the electron transfer from MAMP to levulinic acid. The proposed strategy in this work for designing DESs as a modifier to regulate the carrier materials based on DFT calculations to improve the selective adsorption ability would inspire more ideas in efficient water environmental treatment.

Biomimetic Dual-Layer Imprinted UiO-66-Based Basswood Membranes for Ibuprofen Recognition and Separation

MOF/basswood-based nanocomposite molecularly imprinted membranes had been smoothly compounded on the surface of three-dimensional (3D) basswood materials. Metal–organic framework (MOF) UiO-66-based particles were uniformly encapsulated onto the 3D basswood membranes (BMs) by pretreating basswood with sodium hydroxide (NaOH). The polydopamine (PDA)-based imprinting structure was initially prepared on the as-obtained UiO-66-modified basswood at the first time. A sol–gel imprinting course was then implemented to gain the biomimetic double-layer imprinting based on MOFs grown in situ on BMs (BD-MOF/BMs). Importantly, ibuprofen (IBP) was used as the template molecule throughout the whole dual-imprinted process. Therefore, the sandwich-like double-imprinted layers of IBP could be finally constructed in the BD-MOF/BMs. Abundant IBP-imprinted sites had been obtained in BD-MOF/BMs based on the in situ growth of UiO-66 and dual-imprinted processes, in which the as-prepared BD-MOF/BMs showed particularly high rebinding capacity (120.6 mg g–1) and fast adsorption kinetics. Moreover, the as-prepared PDA-modified surface was not only employed for the first IBP-imprinted layers but also applied to the further construction of the subsequent imprinting sites of IBP; the as-obtained permselectivity coefficients of BD-MOF/BMs were all more than 4.8 based on the selective separation experiments. The stability of the membrane was continuously assessed using dynamic permeation. Finally, the aforementioned experimental results and the approach to environmental protection synthesis demonstrate that our method of BD-MOF/BM synthesis holds significant promise for use in a variety of fields, including selective separation, the chemical industry, the environment, and others.

A Novel Sulfonamide, Molecularly Imprinted, Upconversion Fluorescence Probe Prepared by Pickering Emulsion Polymerization and Its Adsorption and Optical Sensing Performance.

A novel, molecularly imprinted, upconversion fluorescence probe (UCNP@MIFP) for sulfonamide sensing was fabricated by Pickering emulsion polymerization using UCNP@SiO2 particles as the stabilizer and sulfamethazine/sulfamerazine as the co-templates. The synthesis conditions of the UCNP@MIFP were optimized, and the synthesized probe was characterized by scanning electron microscopy, Fourier transform infrared spectrometer, thermogravimetric analyzer, and fluorescence spectrometer. The UCNP@MIFPs showed a good adsorption capacity and a fast kinetic feature for the template. The selectivity experiment revealed that the UCNP@MIFP has a broad-spectrum molecular recognition capability. Good linear relationships were obtained over the concentration range of 1-10 ng/mL for sulfamerazine, sulfamethazine, sulfathiazole, and sulfafurazole, with low limits of detection in the range of 1.37-2.35 ng/mL. The prepared UCNP@MIFP has the potential to detect four sulfonamide residues in food and environmental water.

Abstract 412: Drug combination screen identifies pemigatinib, an FGFR inhibitor, as a mechanism to overcome KRASG12C inhibitor resistance in lung cancer

Abstract Background: Lung cancer is one of the most common tumors, accounting for approximately 1.8 million deaths worldwide in 2020. KRAS is a frequently mutated oncogene, with mutations reported in roughly 20-25% of non-small cell lung cancer cases. Specifically, KRAS mutations at amino acid 12, resulting in a glycine to cysteine (G12C) substitution, occur in approximately 13% and 3% of lung and colon cancers, respectively, and less frequently in other solid tumors. Recently, the development of covalent KRASG12C inhibitors has shown meaningful anticancer activity in patients. However, many patients with KRASG12C do not respond and/or develop resistance to single-agent treatment. Here we investigate combination therapies that may overcome resistance and broaden patient response to KRASG12C inhibitors. Methods: In vitro preclinical KRASG12C models including lung and colon cancer cell lines were treated with a panel of small molecule and covalent KRASG12C inhibitors. The activity of single-agent versus combination treatments was measured in cell viability assays, and screen hits were validated by in vitro mechanism of action studies. Results: A curated set of 152 compounds was used in combination with screen monitoring cell-viability assays across 12 KRAS mutant lung and colon cancer cell lines. Compounds tested included kinase inhibitors targeting oncogenic signaling pathways, epigenetics modifiers, regulators of apoptosis, chemotherapeutics, and other anticancer agents. The screen identified synergy between covalent KRASG12C and several other inhibitors including those for FGFR, EGFR, and SHP2. Notably, pemigatinib, a potent and selective FGFR1-3 inhibitor, had a significantly high Bliss synergy score. Selectivity and siRNA knockdown experiments were performed to identify the specific FGFR isoform involved in synergistic anticancer activity. Inhibition of FGFR1 activity was shown to be essential, whereas an FGFR2-3 specific inhibitor demonstrated only modest activity in combination with KRASG12C inhibitors. Additionally, FGFR1 knockdown combined with KRASG12C inhibition resulted in increased drug sensitivity; in contrast, knockdown of other FGFR family members did not demonstrate similar increase in sensitivity to KRASG12C inhibition. Conclusions: Cell-viability combination screening identified strong synergy between KRASG12C covalent inhibitors and the FGFR1-3 inhibitor pemigatinib in KRASG12C cancer cell lines. The synergistic effect of pemigatinib and KRASG12C inhibition was notably strongest in mesenchymal cancer cell lines. This effect was further validated in in vitro selectivity and siRNA studies. Together, our results support pemigatinib as a promising agent for combination therapy with KRAS inhibitors in lung cancer. Citation Format: Angela Abdollahi, Margaret Favata, Darlise DiMatteo, Sean Schuette, Erika Boarder, Mark Rupar, Ricardo Macarron, Aidan Gilmartin, Hui Wang, Alejandro Amador-Arjona. Drug combination screen identifies pemigatinib, an FGFR inhibitor, as a mechanism to overcome KRASG12C inhibitor resistance in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 412.