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1.
Pestic Biochem Physiol ; 202: 105915, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38879296

ABSTRACT

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is activated by infections of bacteria, fungi, viruses and parasites and mediated cellular and humoral immune responses. In the pea aphid Acyrthosiphon pisum little is known about the function of JAK/STAT signaling in its immune system. In this study, we first showed that expression of genes in the JAK/STAT signaling, including the receptors Domeless1/2, Janus kinase (JAK) and transcriptional factor Stat92E, is up-regulated upon bacteria Escherichia coli and Staphylococcus aureus and fungus Beauveria bassiana infections. After knockdown of expression of these genes by means of dsRNA injection, the aphids harbored more bacteria and suffered more death after infected with E. coli and S. aureus, but showed no significant change after B. bassiana infection. Our study suggests the JAK/STAT signaling contributes to the defense against bacterial infection in the pea aphid.


Subject(s)
Aphids , Janus Kinases , STAT Transcription Factors , Signal Transduction , Animals , Janus Kinases/metabolism , STAT Transcription Factors/metabolism , Staphylococcus aureus/physiology , Escherichia coli , Insect Proteins/metabolism , Insect Proteins/genetics , Beauveria/physiology
2.
Animals (Basel) ; 14(11)2024 May 25.
Article in English | MEDLINE | ID: mdl-38891610

ABSTRACT

An experiment was conducted to evaluate the effects of increasing the dose of a novel consensus bacterial 6-phytase variant expressed in Trichoderma reesei (PhyG) in broilers fed complex diets highly deficient in minerals, dig AA, and energy. Diets were a nutrient-adequate control (PC); a nutrient-reduced control (NC) formulated with a reduction in available P (avP) by 0.199%, Ca by 0.21%, crude protein by 0.72-1.03%, dig Lys by 0.064-0.084%, Na by 0.047%, and ME by 87.8 kcal/kg, respectively; and NC supplemented with PhyG at 500, 1000, and 2000 FTU/kg feed. BW was decreased and FCR increased in the NC vs. PC, while the PhyG treatments were similar to the PC. Carcass yield and bone ash were also maintained with PhyG supplementation. Phytase provided economic benefit on a feed cost per kg of weight basis for 1 to 35 d; the cost reductions equated to USD 0.006, 0.016, and 0.02/kg BWG at 500, 1000, and 2000 FTU/kg. In conclusion, this trial demonstrated that supplementation with a novel consensus phytase variant in diets highly deficient in minerals, dig AA, and energy maintained growth performance and provided economic benefit, with production benefits being maximized at inclusion levels of 2000 FTU/kg.

3.
Acad Radiol ; 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38902111

ABSTRACT

RATIONALE AND OBJECTIVES: It is critical to predict early recurrence (ER) after percutaneous thermal ablation (PTA) for hepatocellular carcinoma (HCC). We aimed to develop and validate a delta-radiomics nomogram based on multi-phase contrast-enhanced magnetic resonance imaging (MRI) to preoperatively predict ER of HCC after PTA. MATERIALS AND METHODS: We retrospectively enrolled 164 patients with HCC and divided them into training, temporal validation, and other-scanner validation cohorts (n = 110, 29, and 25, respectively). The volumes of interest of the intratumoral and/or peritumoral regions were delineated on preoperative multi-phase MR images. Original radiomics features were extracted from each phase, and delta-radiomics features were calculated. Logistic regression was used to train the corresponding radiomics models. The clinical and radiological characteristics were evaluated and combined to establish a clinical-radiological model. A fusion model comprising the best radiomics scores and clinical-radiological risk factors was constructed and presented as a nomogram. The performance of each model was evaluated and recurrence-free survival (RFS) was assessed. RESULTS: Child-Pugh grade B, high-risk tumor location, and an incomplete/absent tumor capsule were independent predictors of ER. The optimal radiomics model comprised 12 delta-radiomics features with areas under the curve (AUCs) of 0.834, 0.795, and 0.769 in the training, temporal validation, and other-scanner validation cohorts, respectively. The nomogram showed the best predictive performance with AUCs as 0.893, 0.854, and 0.827 in the three datasets. There was a statistically significant difference in RFS between the risk groups calculated using the delta-radiomics model and nomogram. CONCLUSIONS: The nomogram combined with the delta-radiomic score and clinical-radiological risk factors could non-invasively predict ER of HCC after PTA.

4.
Acc Chem Res ; 57(11): 1595-1607, 2024 06 04.
Article in English | MEDLINE | ID: mdl-38759211

ABSTRACT

High-precision neuromodulation plays a pivotal role in elucidating fundamental principles of neuroscience and treating specific neurological disorders. Optical neuromodulation, enabled by spatial resolution defined by the diffraction limit at the submicrometer scale, is a general strategy to achieve such precision. Optogenetics offers single-neuron spatial resolution with cellular specificity, whereas the requirement of genetic transfection hinders its clinical application. Direct photothermal modulation, an alternative nongenetic optical approach, often associates a large temperature increase with the risk of thermal damage to surrounding tissues.Photoacoustic (also called optoacoustic) neural stimulation is an emerging technology for neural stimulation with the following key features demonstrated. First, the photoacoustic approach demonstrated high efficacy without the need for genetic modification. The generated pulsed ultrasound upon ns laser pulses with energy ranging from a few µJ to tens of µJ is sufficient to activate wild-type neurons. Second, the photoacoustic approach provides sub-100-µm spatial precision. It overcomes the fundamental wave diffraction limit of ultrasound by harnessing the localized ultrasound field generated through light absorption. A spatial precision of 400 µm has been achieved in rodent brains using a fiber-based photoacoustic emitter. Single-cell stimulation in neuronal cultures in vitro and in brain slices ex vivo is achieved using tapered fiber-based photoacoustic emitters. This precision is 10 to 100 times better than that for piezo-based low-frequency ultrasound and is essential to pinpoint a specific region or cell population in a living brain. Third, compared to direct photothermal stimulation via temperature increase, photoacoustic stimulation requires 40 times less laser energy dose to evoke neuron activities and is associated with a minimal temperature increase of less than 1 °C, preventing potential thermal damage to neurons. Fourth, photoacoustics is a versatile approach and can be designed in various platforms aiming at specific applications. Our team has shown the design of fiber-based photoacoustic emitters, photoacoustic nanotransducers, soft biocompatible photoacoustic films, and soft photoacoustic lenses. Since they interact with neurons through ultrasound without the need for direct contact, photoacoustic enables noninvasive transcranial and dura-penetrating brain stimulation without compromising high precision.In this Account, we will first review the basic principles of photoacoustic and discuss the key design elements of PA transducers for neural modulation guided by the principle. We will also highlight how these design goals were achieved from a materials chemistry perspective. The design of different PA interfaces, their unique capability, and their applications in neural systems will be reviewed. In the end, we will discuss the remaining challenges and future perspectives for this technology.


Subject(s)
Neurons , Photoacoustic Techniques , Photoacoustic Techniques/methods , Animals , Humans , Optogenetics/methods , Brain/diagnostic imaging
5.
Langmuir ; 40(22): 11401-11410, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38767862

ABSTRACT

To functionalize interfaces with supported biomembranes and membrane proteins, the challenge is to build stabilized and supported systems that mimic the native lipid microenvironment. Our objective is to control substrate-to-biomembrane spacing and the tethering chemistry so proteoliposomes can be fused and conjugated without perturbation of membrane protein function. Furthermore, the substrates need to exhibit low protein and antibody nonspecific binding to use these systems in assays. We have employed protein orthogonal coupling schemes in concert with multiarm poly(ethylene glycol) (PEG) technology to build supported biomembranes on microspheres. The lipid bilayer structures and tailored substrates of the microsphere-supported biomembranes were analyzed via flow cytometry, confocal fluorescence, and super-resolution imaging microscopy, and the lateral fluidity was quantified using fluorescence recovery after photobleaching (FRAP) techniques. Under these conditions, the 4-arm-PEG20,000-NH2 based configuration gave the most desirable tethering system based on lateral diffusivity and coverage.


Subject(s)
Lipid Bilayers , Polyethylene Glycols , Polyethylene Glycols/chemistry , Lipid Bilayers/chemistry , Microspheres , Fluorescence Recovery After Photobleaching , Polymers/chemistry
6.
Biomed Pharmacother ; 175: 116724, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38761424

ABSTRACT

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become one of the most prevalent liver diseases worldwide, and its occurrence is strongly associated with obesity, insulin resistance (IR), genetics, and metabolic stress. Ranging from simple fatty liver to metabolic dysfunction-associated steatohepatitis (MASH), even to severe complications such as liver fibrosis and advanced cirrhosis or hepatocellular carcinoma, the underlying mechanisms of MASLD progression are complex and involve multiple cellular mediators and related signaling pathways. Pattern recognition receptors (PRRs) from the innate immune system, including Toll-like receptors (TLRs), C-type lectin receptors (CLRs), NOD-like receptors (NLRs), RIG-like receptors (RLRs), and DNA receptors, have been demonstrated to potentially contribute to the pathogenesis for MASLD. Their signaling pathways can induce inflammation, mediate oxidative stress, and affect the gut microbiota balance, ultimately resulting in hepatic steatosis, inflammatory injury and fibrosis. Here we review the available literature regarding the involvement of PRR-associated signals in the pathogenic and clinical features of MASLD, in vitro and in animal models of MASLD. We also discuss the emerging targets from PRRs for drug developments that involved agent therapies intended to arrest or reverse disease progression, thus enabling the refinement of therapeutic targets that can accelerate drug development.


Subject(s)
Receptors, Pattern Recognition , Humans , Animals , Receptors, Pattern Recognition/metabolism , Fatty Liver/metabolism , Signal Transduction , Immunity, Innate
7.
BMC Chem ; 18(1): 97, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38715128

ABSTRACT

Modification of marketed drugs is an important way to develop drugs because its safety and clinical applicability. Oxygen-nitrogen heterocycles are a class of important active substances discovered in the process of new drug development. Dolutegravir, an HIV drug with a nitrogen-oxygen heterocycle structure, has the potential ability to inhibit cell survival. In order to find and explore novel anti-tumor drugs, new dolutegravir derivatives bearing different 1,2,3-triazole moieties were prepared via click reactions. In vitro biological experiments performed in several lung cancer cell lines suggested that these novel compounds displayed potent anti-tumor ability. Especially, the compound 9e with a substituent of 2-methyl-3-nitrophenyl and the compound 9p with a substituent of 3-trifluoromethylphenyl were effective against PC-9 cell line with IC50 values of 3.83 and 3.17 µM, respectively. Moreover, compounds 9e and 9p were effective against H460 and A549 cells. Further studies suggested that compounds 9e and 9p could induce cancer cell apoptosis in PC-9 and H460, inhibit cancer cell proliferation, change the cell cycle, and increase the level of reactive oxygen species (ROS) which further induce tumor cell apoptosis. In addition, compounds 9e and 9p increased LC3 protein expression which was the key regulator in autophagy signaling pathway in PC-9 cells. Compound 9e also showed low toxicity against normal cells, and could be regarded as an interesting lead compound for further structure optimization.

8.
Chemistry ; 30(27): e202304118, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38433408

ABSTRACT

New chiral ligands could be obtained by introducing proline moieties and imidazoline moieties to binaphthyl skeletons. The chiral ligands exhibited balanced rigidity and flexibility which could allow the change of the conformations during the reactions on one hand, and could provide sufficient asymmetric induction on the other. The proline moiety could act as a linker connecting the binaphthyl skeletons and the imidazoline moieties as well as a coordinating group for the central metal, and the electronic and steric properties of the imidazoline groups could be carefully fine-tuned by the use of different substituents. In the presence of Cu(II) catalyst bearing such chiral ligands, aza-Friedel-Crafts reaction of 1-naphthols and electron-rich phenols with isatin-derived ketimines provided the desired products with good to excellent yields and up to 99 % ee. The reactions showed good scalability, and excellent ee could still be obtained when the reaction was carried out in gram-scale.

9.
Front Oncol ; 14: 1276526, 2024.
Article in English | MEDLINE | ID: mdl-38482209

ABSTRACT

Objectives: This study aimed to create and validate a radiomics nomogram for non-invasive preoperative Ki-67 expression level prediction in patients with bladder cancer (BCa) using contrast-enhanced CT radiomics features. Methods: A retrospective analysis of 135 patients was conducted, 79 of whom had high levels of Ki-67 expression and 56 of whom had low levels. For the dimensionality reduction analysis, the best features were chosen using the least absolute shrinkage selection operator and one-way analysis of variance. Then, a radiomics nomogram was created using multiple logistic regression analysis based on radiomics features and clinical independent risk factors. The performance of the model was assessed using the Akaike information criterion (AIC) value, the area under the curve (AUC) value, accuracy, sensitivity, and specificity. The clinical usefulness of the model was assessed using decision curve analysis (DCA). Results: Finally, to establish a radiomics nomogram, the best 5 features were chosen and integrated with the independent clinical risk factors (T stage) and Rad-score. This radiomics nomogram demonstrated significant correction and discriminating performance in both the training and validation sets, with an AUC of 0.836 and 0.887, respectively. This radiomics nomogram had the lowest AIC value (AIC = 103.16), which was considered to be the best model. When compared to clinical factor model and radiomics signature, DCA demonstrated the more value of the radiomics nomogram. Conclusion: Enhanced CT-based radiomics nomogram can better predict Ki-67 expression in BCa patients and can be used for prognosis assessment and clinical decision making.

10.
Mol Psychiatry ; 2024 Feb 21.
Article in English | MEDLINE | ID: mdl-38383769

ABSTRACT

CD33 is a transmembrane receptor expressed on cells of myeloid lineage and regulates innate immunity. CD33 is a risk factor for Alzheimer's disease (AD) and targeting CD33 has been a promising strategy drug development. However, the mechanism of CD33's action is poorly understood. Here we investigate the mechanism of anti-CD33 antibody HuM195 (Lintuzumab) and its single-chain variable fragment (scFv) and examine their therapeutic potential. Treatment with HuM195 full-length antibody or its scFv increased phagocytosis of ß-amyloid 42 (Aß42) in human microglia and monocytes. This activation of phagocytosis was driven by internalization and degradation of CD33, thereby downregulating its inhibitory signal. HumM195 transiently induced CD33 phosphorylation and its signaling via receptor dimerization. However, this signaling decayed with degradation of CD33. scFv binding to CD33 leads to a degradation of CD33 without detection of the CD33 dimerization and signaling. Moreover, we found that treatments with either HuM195 or scFv promotes the secretion of IL33, a cytokine implicated in microglia reprogramming. Importantly, recombinant IL33 potentiates the uptake of Aß42 in monocytes. Collectively, our findings provide unanticipated mechanistic insight into the role of CD33 signaling in both monocytes and microglia and define a molecular basis for the development of CD33-based therapy of AD.

11.
J Med Chem ; 67(5): 3542-3570, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38381650

ABSTRACT

GPR84 is a putative medium-chain fatty acid receptor that is implicated in regulation of inflammation and fibrogenesis. Studies have indicated that GPR84 agonists may have therapeutic potential in diseases such as Alzheimer's disease, atherosclerosis, and cancer, but there is a lack of quality tool compounds to explore this potential. The fatty acid analogue LY237 (4a) is the most potent GPR84 agonist disclosed to date but has unfavorable physicochemical properties. We here present a SAR study of 4a. Several highly potent agonists were identified with EC50 down to 28 pM, and with SAR generally in excellent agreement with structure-based modeling. Proper incorporation of rings and polar groups resulted in the identification of TUG-2099 (4s) and TUG-2208 (42a), both highly potent GPR84 agonists with lowered lipophilicity and good to excellent solubility, in vitro permeability, and microsomal stability, which will be valuable tools for exploring the pharmacology and therapeutic prospects of GPR84.


Subject(s)
Inflammation , Receptors, G-Protein-Coupled , Humans , Receptors, G-Protein-Coupled/metabolism , Inflammation/metabolism , Fatty Acids/metabolism , Structure-Activity Relationship
12.
Front Psychol ; 15: 1232312, 2024.
Article in English | MEDLINE | ID: mdl-38414876

ABSTRACT

Objective: Mind wandering is a common phenomenon among athletes during training and competition, and can lead to poor performance. We attempt to clarify which personality type is more prone to mind wandering and the role of trait anxiety between them. Methods: Six hundred and eighty-one athletes participated in this cross sectional study. Participants completed the Athlete Mind Wandering Scale, The Chinese adjectives scale of Big-Five factor personality short scale version and Pre-Competition Emotion Scale-Trait questionnaires. The survey data was tested for common method biases, Pearson correlation analysis, and structural equation model by SPSS 25.0 and Mplus 7.0. Results: Common method biases can be accepted in this study. (1) Athletes' neuroticism was significantly and positively correlated with trait anxiety and mind wandering, respectively, athletes' extraversion, agreeableness, conscientiousness, and openness were significantly and negatively correlated with trait anxiety and mind wandering respectively; the athletes' trait anxiety was significantly and positively correlated with mind wandering; (2) By constructing mediating models, the direct effects of athletes' extraversion, agreeableness, conscientiousness, neuroticism, and openness on mind wandering were insignificant. The mediating effect of athletes' trait anxiety between the five personalities and mind wandering was significant. Conclusion: Trait anxiety in athletes plays a fully mediating role between the relationship of personality and mind wandering. Athletes' extraversion, agreeableness, conscientiousness, neuroticism, and openness can all have an impact on mind wandering through the mediating role of trait anxiety. Athletes can use the mediating role of trait anxiety to intervene the frequency of mind wandering.

13.
Int J Biol Macromol ; 263(Pt 2): 130362, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38395287

ABSTRACT

In this study, anthocyanin from Garcinia mangostana shell extract (Mse) was used as pH indicator to prepare intelligent carboxymethyl cellulose (CMC) based composite films. The structure and properties of the CMC-based composite films were characterized and discussed in detail. Results showed that the CMC-based composite films with Mse had excellent mechanical, antibacterial and antioxidant abilities. Especially, the carboxymethyl cellulose/corn starch/Garcinia mangostana shell extract (CMC/Cst/Mse) composite film had best mechanical properties (20.62 MPa, 4.06 % EB), lowest water vapor permeability (1.80 × 10-12 g·cm/(cm2·s·Pa)), excellent ultraviolet (UV) blocking performance, and the best antibacterial and antioxidant abilities. The pH sensitivity of composite films which had Mse obviously changed with time when the fish freshness was monitored at 25 °C. Given the good pH sensitivity of the composite films, it had significant potential for application of intelligent packaging film as a food packaging material to indicate the freshness of fish.


Subject(s)
Antioxidants , Garcinia mangostana , Animals , Antioxidants/chemistry , Anthocyanins/pharmacology , Carboxymethylcellulose Sodium/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Food Packaging/methods , Plant Extracts/pharmacology
14.
Nat Methods ; 21(2): 342-352, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38191931

ABSTRACT

Simultaneous spatial mapping of the activity of multiple enzymes in a living system can elucidate their functions in health and disease. However, methods based on monitoring fluorescent substrates are limited. Here, we report the development of nitrile (C≡N)-tagged enzyme activity reporters, named nitrile chameleons, for the peak shift between substrate and product. To image these reporters in real time, we developed a laser-scanning mid-infrared photothermal imaging system capable of imaging the enzymatic substrates and products at a resolution of 300 nm. We show that when combined, these tools can map the activity distribution of different enzymes and measure their relative catalytic efficiency in living systems such as cancer cells, Caenorhabditis elegans, and brain tissues, and can be used to directly visualize caspase-phosphatase interactions during apoptosis. Our method is generally applicable to a broad category of enzymes and will enable new analyses of enzymes in their native context.


Subject(s)
Diagnostic Imaging , Nitriles , Coloring Agents
15.
Int J Biol Macromol ; 254(Pt 3): 128082, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37972838

ABSTRACT

This study investigated the effect of varying magnetic field intensities (ranging from 0 to 10 mT) on the quality characteristics of dough with 40 % potato pulp substitution (DPP). The results indicated that the DPP fermented with a 4 mT magnetic field exhibited a significant enhancement in the combination of water and substrate, thereby elevating the viscoelastic properties of DPP through reinforcing the stability of gluten network. Meanwhile, DPP treated with a 4 mT magnetic field exhibited the highest amount of disulfide bonds (11.64 µmol SS/g sample). This is accompanied by a prominent cross-linkage structure, as evidenced by SDS-PAGE and CLSM. Notably, the application of a magnetic field substantially augments the dough's capacity to retain gas during fermentation. In addition, the application of magnetic field significantly increased the wet gluten content (20.85 %, P < 0.05) in DPP, which improved tensile properties and an acceptable color profile. The introduction of a magnetic field induces gluten aggregation, which in turn results in heightened particle size distribution and ζ-potential values. In conclusion, this study emphasize the potential of magnetic field technology as a viable method to enhance the overall quality attributes of dough enriched with potato pulp substitution.


Subject(s)
Glutens , Solanum tuberosum , Glutens/chemistry , Flour , Bread
16.
Poult Sci ; 102(12): 103131, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37926013

ABSTRACT

The effect of applying an energy and nutrient matrix to a wheat-corn-soybean meal-based diet supplemented with a novel consensus bacterial 6-phytase variant (PhyG) and xylanase-ß-glucanase on growth performance, bone mineralization, carcass weights, feed costs, and carbon footprint was evaluated. A randomized complete block design (3,300 Ross 308 mixed-sex birds; 60 pens, 12 pens per treatment) tested 5 treatments: 1) a positive control diet (PC), containing 0.92, 0.84, 0.71% Ca and 0.43, 0.38, 0.30% digestible P during 1 to 10, 11 to 21, and 22 to 32 d of age, respectively; 2) a negative control reduced in Ca, digestible P, digestible AA, ME, and Na by phase based on the PhyG dosing regimen (NC1); 3) NC1 supplemented with PhyG at 2,000, 1,500, and 1,000 FTU/kg by phase (NC1+PhyG); 4) as NC1 but additionally reduced in ME (NC2); and 5) NC2 supplemented with PhyG as in 3) plus 1,220 U/kg of xylanase and 152 U/kg of ß-glucanase (NC2+PhyG+XB). Final (d 32) BW, overall (0-32 d of age) ADFI, FCR, d 10 and 32 tibia ash and carcass part weights were reduced or impaired (P < 0.05) in NC1 and NC2 vs. PC (d 32 BW -477 g/bird (23.4%) and -422 g/bird (20.7%), respectively). Growth performance (all measures, all phases) was improved and tibia ash (at 10 and 32 d of age), total carcass thigh, breast and leg weights were increased (P < 0.05) in NC1+PhyG vs. NC1, and NC2+PhyG+XB vs. NC2. Overall growth performance outcomes in NC1+PhyG and NC2+PhyG+XB were not different (P > 0.05) from the PC. Total feed cost and carbon footprint per kilogram BW gain (BWG) were reduced (P < 0.05) vs. PC in NC2+PhyG+XB [-0.052 € and -376 g CO2 eq./kg BWG, respectively] and NC1+PhyG [-0.038 € and -260 g CO2 eq./kg BWG, respectively]. The results validated the nutrient matrices in the test diets and highlighted a potential feed cost and environmental sustainability benefit which was greatest when the enzymes were applied in combination.


Subject(s)
6-Phytase , Animals , Zea mays , Triticum , Glycine max , Carbon Dioxide/pharmacology , Flour , Chickens , Dietary Supplements , Diet/veterinary , Nutrients , Animal Feed/analysis , Animal Nutritional Physiological Phenomena , Digestion
17.
J Org Chem ; 88(21): 14928-14944, 2023 Nov 03.
Article in English | MEDLINE | ID: mdl-37874252

ABSTRACT

This paper describes the design and application of new binaphthyl-proline-based chiral ligands bearing imidazoline functional groups. These chiral ligands incorporate the advantages of both the binaphthyl and proline skeletons, they are featured with regulatable electronic and steric properties for the imidazoline functional groups, and form chiral complexes with different metal salts such as cuprous acetate. In the presence of an appropriate amount of a chiral catalyst, enantioselective conjugate addition of 4-hydroxycoumarin or related nucleophiles to different ß,γ-unsaturated α-ketoesters proceeded readily, giving the desired products in high yield (up to 99%) and excellent enantiomeric excess (up to 99%).

18.
J Org Chem ; 88(20): 14345-14350, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37791977

ABSTRACT

The copper(II)-catalyzed enantioselective aza-Friedel-Crafts reaction of indoles with isatin-derived N-Boc-ketimines was developed by using tunable chiral O-N-N tridentate ligands derived from BINOL and proline. In general, the reaction afforded chiral 3-indolyl-3-aminooxindoles under mild conditions in high yields (83-97%) with excellent ee (69-99%).

19.
Sci Adv ; 9(43): eadi2181, 2023 Oct 27.
Article in English | MEDLINE | ID: mdl-37889965

ABSTRACT

Stimulated Raman scattering (SRS) microscopy has shown enormous potential in revealing molecular structures, dynamics, and couplings in complex systems. However, the sensitivity of SRS is fundamentally limited to the millimolar level due to shot noise and the small modulation depth. To overcome this barrier, we revisit SRS from the perspective of energy deposition. The SRS process pumps molecules to their vibrationally excited states. The subsequent relaxation heats up the surroundings and induces refractive index changes. By probing the refractive index changes with a laser beam, we introduce stimulated Raman photothermal (SRP) microscopy, where a >500-fold boost of modulation depth is achieved. The versatile applications of SRP microscopy on viral particles, cells, and tissues are demonstrated. SRP microscopy opens a way to perform vibrational spectroscopic imaging with ultrahigh sensitivity.

20.
Appl Microbiol Biotechnol ; 107(22): 6937-6947, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37704770

ABSTRACT

The rapid and efficient consumption of carbon and nitrogen sources by brewer's yeast is critical for the fermentation process in the brewing industry. The comparison of the growth characterizations of typical ale and lager yeast, as well as their consumption preference to carbon and nitrogen sources were investigated in this study. Results showed that the ale strain grew faster and had a more extended stationary phase than the lager strain. However, the lager strain was more tolerant to the stressful environment in the later stage of fermentation. Meanwhile, the ale and lager yeast strains possessed varying preferences for metabolizing the specific fermentable sugar or free amino acid involved in the wort medium. The lager strain had a strong capacity to synthesize the extracellular invertase required for hydrolyzing sucrose as well as a strong capability to metabolize glucose and fructose. Furthermore, the lager strain had an advantage in consuming Lys, Arg, Val, and Phe, whereas the ale strain had a higher assimilation rate in consuming Tyr. These findings provide valuable insights into selecting the appropriate brewer's yeast strain based on the wort components for the industrial fermentation process. KEY POINTS: • The lager strain is more tolerant to the stressful environment. • The lager strain has the great capability to synthesize the extracellular invertase. • The assimilation efficiency of free amino acid varies between ale and lager.

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