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1.
Adv Sci (Weinh) ; : e2409457, 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39401407

RESUMO

The transition metal-catalyzed direct coupling reactions involving electron-rich Fischer carbene species are largely underdeveloped and remain a big challenge. Here, a direct coupling reaction of azoles and azine N-oxides is reported with Fischer copper carbene species bearing an α-siloxy group i, which can be in situ generated from acylsilanes catalytically under photoirradiation and redox-neutral conditions. This coupling reaction between electron-rich α-siloxy Fischer Cu-carbene species with hard carbanion nucleophiles may undergo a bimetallic relay process, which is confirmed by the kinetic analysis and in situ NMR analysis. This reaction features mild conditions and remarkable heterocycle compatibility. Notably, this protocol tolerates a series of azole or azine N-oxide derivatives, including benzoxazole, benzothiazole, benzoimidazole, benzoisoxazole, oxazole, oxadiazole, triazolo[4,3-a]pyridine, purine, caffeine, pyridine N-oxide, quinoline N-oxide, pyrazine N-oxide, pyridazine N-oxide, etc. The synthetic value of this approach is demonstrated by the efficient synthesis of a histamine h4 receptor ligand and a marketed drug carbinoxamine.

2.
ACS Omega ; 9(39): 40920-40931, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39371971

RESUMO

Three supramolecular architectures, [Cu2(dpds)2(C5O5)2(H2O)4]·3H2O (1), [Cu(dpds)(C5O5)]·3H2O (2), and [Cu2(dpds)2(C5O5)2]·9H2O·C2H5OH (3) (dpds = 4,4'-dipyridyldisulfide and C5O5 2- (croconate) = dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione), have been synthesized and structurally characterized. Compound 1 contains two crystallographically independent Cu(II) ions, which are both distorted octahedral geometry with elongation along the croconate- and H2O-bound axial positions and bonded with two N atoms of two dpds, two O atoms of one C5O5 2-, and two H2O molecules. Two crystallographically independent dpds ligands, both adopting the bis-monodentate bridging mode, connect two Cu(II) ions to form a one-dimensional zigzag chain-like coordination polymer. In 2 and 3, there are two and three crystallographically independent Cu(II) ions, respectively, which are all distorted octahedral geometries with elongation along the croconate-bound axial positions six-coordinated and bonded with two N atoms of two dpds ligands in cis- or/and trans-forms and four O atoms of two C5O5 2- ligands. The dpds ligands in 2 and 3 all adopt the bis-monodentate bridging mode, and the C5O5 2- ligands act as bridging ligands with bridging bis-bidentate through three C5O5 2- oxygen atoms in 2 and bridging bis-bidentate through four adjacent C5O5 2- oxygen atoms in 3, respectively, linking the Cu(II) ions to generate a two-dimensional layered and a three-dimensional metal-organic framework, respectively. The structural diversity and dimensionality observed in 1-3 may be attributed to the cis- or/and trans-coordination sphere of Cu(II) centers with two dpds ligands and the coordination modes of croconate ligands. Thermal stability and in situ temperature-dependent structural variations of 1-3 have been verified by thermogravimetric analysis and powder X-ray diffraction measurements. Compounds 1 and 3 both exhibit water vapor capture behaviors with hysteresis isotherms.

3.
Environ Sci Technol ; 2024 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-39468881

RESUMO

Anaerobic ammonium oxidation (anammox) is efficient and cost-effective for treating high-strength ammonia wastewater, but the organics in wastewater will affect its stability. To address this challenge, it is crucial to gain a deep understanding of the inhibitory effects and mechanisms of organics stress on anammox bacteria. The review provided a comprehensive classification of organics and evaluated their specific effects on the anammox system according to their respective characteristics. Based on the micro to macro perspective, the "molecule-cell-ecology" inhibitory mechanism of organics on anammox bacteria was proposed. The molecular observation systematically summarized the binding process and action sites of organics with anammox bacteria. At the cellular observation, the mechanisms of organics effects on extracellular polymeric substances, membranes, and anammoxosome of anammox bacteria were also expounded. At the ecological observation, the dynamic changes in coexisting populations and their role in organics transformation were further discussed. Further revelations on response mechanisms and inhibition mitigation strategies were proposed to broaden the applicability of anammox systems for organic wastewater. This review offered a multidimensional understanding of the organics inhibitory mechanism of anammox bacteria and provided a theoretical foundation for anammox systems.

4.
J Biomed Sci ; 31(1): 88, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39237902

RESUMO

BACKGROUND: Dysregulation of vascular homeostasis can induce cardiovascular diseases and increase global mortality rates. Although lineage tracing studies have confirmed the pivotal role of modulated vascular smooth muscle cells (VSMCs) in the progression of pathological vascular remodeling, the underlying mechanisms are still unclear. METHODS: The expression of Tudor-SN was determined in VSMCs of artery stenosis, PDGF-BB-treated VSMCs and atherosclerotic plaque. Loss- and gain-of-function approaches were used to explore the role of Tudor-SN in the modulation of VSMCs phenotype both in vivo and in vitro. RESULTS: In this study, we demonstrate that Tudor-SN expression is significantly elevated in injury-induced arteries, atherosclerotic plaques, and PDGF-BB-stimulated VSMCs. Tudor-SN deficiency attenuates, but overexpression aggravates the synthetic phenotypic switching of VSMCs and pathological vascular remodeling. Loss of Tudor-SN also reduces atherosclerotic plaque formation and increases plaque stability. Mechanistically, PTEN, the major regulator of the MAPK and PI3K-AKT signaling pathways, plays a vital role in Tudor-SN-mediated regulation on proliferation and migration of VSMCs. Tudor-SN facilitates the polyubiquitination and degradation of PTEN via NEDD4-1, thus exacerbating vascular remodeling under pathological conditions. BpV (HOpic), a specific inhibitor of PTEN, not only counteracts the protective effect of Tudor-SN deficiency on proliferation and migration of VSMCs, but also abrogates the negative effect of carotid artery injury-induced vascular remodeling in mice. CONCLUSIONS: Our findings reveal that Tudor-SN deficiency significantly ameliorated pathological vascular remodeling by reducing NEDD4-1-dependent PTEN polyubiquitination, suggesting that Tudor-SN may be a novel target for preventing vascular diseases.


Assuntos
Ubiquitina-Proteína Ligases Nedd4 , PTEN Fosfo-Hidrolase , Ubiquitinação , Remodelação Vascular , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Ubiquitina-Proteína Ligases Nedd4/genética , Animais , Camundongos , PTEN Fosfo-Hidrolase/metabolismo , PTEN Fosfo-Hidrolase/genética , Músculo Liso Vascular/metabolismo , Masculino , Miócitos de Músculo Liso/metabolismo , Camundongos Endogâmicos C57BL
5.
J Hazard Mater ; 480: 135928, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39332254

RESUMO

Although soluble bio-accelerators have proven effective in mitigating Cr(VI) inhibition within denitrification system, issues persist in immobilizing bio-accelerators and making them slow-release for sustained regulation. In this study, a novel strategy was proposed to fabricate immobilized bio-accelerators with controlled structure, sustained release property by 3D printing technology. Notably, the sustained release of bio-accelerators from 3D-printed bio-accelerators (3DP-B) lasted for at least 144 h. Compared to control group, 3DP-B with basic components (3DP-BB) shortened the recovery time by 1.4 folds, and the COD and NO3--N removal efficiency was 36.5 % and 38.0 % higher than that of natural recovery. Correspondingly, the activity of key enzymes (nitrate reductase, nitrite reductase, nitric oxide reductase, and nitrous oxide reductase), electron transfer system activity and extracellular polymer substances of denitrification biofilm maintained at relatively high levels. Furthermore, introducing 60 mg·L-1 anthraquinone-2,6-disulfonate (AQDS) into the ink showed noticeable superiority on the bio-inhibition release over 1000 mg·L-1 AQDS. The released AQDS facilitated the electron transport capacity by 1.25 times compared with control group. The groundbreaking findings of this study could advance the development of 3D printing technology and utilization of bio-accelerators in the field of wastewater treatment.

6.
Org Lett ; 26(38): 8171-8176, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39297727

RESUMO

Here, we report the preparation of lactones via Ni-catalyzed alkene hydroxylarylation and sequential intramolecular lactonization with O2 as a green oxidant and oxygen source. The bulky 1,3-diketone ligand is crucial by enabling Ni-catalyzed hydroxylarylation of alkenes, providing numerous phthalide and furanone derivatives with high efficiency under mild conditions. The synthetic value of this methodology was further demonstrated by the efficient synthesis of typhaphthalide and a monoamine oxidase B inhibitor.

7.
Phys Rev Lett ; 133(3): 036202, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39094151

RESUMO

Ferroelectric hafnia-based thin films have attracted significant interest due to their compatibility with complementary metal-oxide-semiconductor technology (CMOS). Achieving and stabilizing the metastable ferroelectric phase in these films is crucial for their application in ferroelectric devices. Recent research efforts have concentrated on the stabilization of the ferroelectric phase in hafnia-based films and delving into the mechanisms responsible for this stability. In this study, we experimentally demonstrate that stabilization of the ferroelectric phase in Hf_{0.5}Zr_{0.5}O_{2} (HZO) can be controlled by the interfacial charge transfer and the associated hole doping of HZO. Using the meticulously engineered charge transfer between an La_{1-x}Sr_{x}MnO_{3} buffer layer with variable Sr concentration x and an HZO film, we find the optimal x=0.33 that provides the required hole doping of HZO to most efficiently stabilize its ferroelectric phase. Our theoretical modeling reveals that the competition of the hole distribution between the threefold and fourfold coordinated oxygen sites in HZO controls the enhancement or reduction of the ferroelectric phase. Our findings offer a novel strategy to stabilize the ferroelectric phase of hafnia-based films and provide new insights into the development of ferroelectric devices compatible with CMOS.

8.
Org Lett ; 26(35): 7436-7441, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39185945

RESUMO

Here, we report the development and application of a novel class of spirosilacycle-based diphosphine ligands (SPOSiPs). This type of diphosphine ligand could be readily prepared in two steps with high efficiency starting from enantiopure spirobiphenoxasilin-diol (SPOSiOL). According to the structural analysis of SPOSiP and its PdCl2 complex, SPOSiPs possess a flexible chiral pocket and feature a rigid configuration, a large dihedral angle, a long P-P distance, and a large P-M-P bite angle in their metal complexes. The potentials of SPOSiPs in asymmetric catalysis have also been preliminarily disclosed.

9.
Intellect Dev Disabil ; 62(4): 287-305, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39069302

RESUMO

This study used data from the National Longitudinal Transition Study 2012 (NLTS 2012) to explore the future goal aspirations of students with extensive support needs who participate in alternate assessments, compared to other students with extensive support needs and to students with other disabilities. We examined students' individualized education program (IEP)/transition planning meeting experiences and postschool goals in relation to their functional, communication, and self-advocacy skills, as well as their school/community support. Students with other disabilities held higher expectations than all students with extensive support needs for future participation in postsecondary education, employment, independent living, and financial independence. All students had higher postschool goal expectations than their parents. Implications for supporting students with extensive support needs and directions for future research and practice are discussed.


Assuntos
Objetivos , Estudantes , Humanos , Masculino , Feminino , Estudos Longitudinais , Adulto Jovem , Adolescente , Adulto , Aspirações Psicológicas , Deficiência Intelectual/reabilitação , Apoio Social , Educação Inclusiva , Emprego
10.
J Chem Inf Model ; 64(15): 6132-6146, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39078379

RESUMO

Staphylococcus aureus (S. aureus) is a major global health concern, causing various infections and presenting challenges due to antibiotic resistance. In particular, methicillin-resistant S. aureus, vancomycin-intermediate S. aureus (VISA), and vancomycin-resistant S. aureus pose significant obstacles in treating S. aureus infections. Therefore, the critical need for novel drugs to counter these resistant forms is pressing. Two-component systems (TCSs), integral to bacterial regulation, offer promising targets for disruption. In this study, a comprehensive approach, involving pharmacophore-based inhibitor screening, along with biochemical and biophysical analyses were conducted to identify, characterize, and validate potential inhibitors targeting the response regulator VraRC of S. aureus. The constructed pharmacophore model, Phar-VRPR-N3, demonstrated effectiveness in identifying a potent inhibitor, TST1N-224 (IC50 = 60.2 ± 4.0 µM), against the formation of the VraRC-DNA complex. Notably, TST1N-224 exhibited strong binding to VraRC (KD = 23.4 ± 1.2 µM) using a fast-on-fast-off binding mechanism. Additionally, NMR-based molecular modeling revealed that TST1N-224 predominantly interacts with the α9- and α10-helixes of the DNA-binding domain of VraR, where the interactive and functionally essential residues (N165, K180, S184, and R195) act as hotspots for structure-based inhibitor optimization. Furthermore, TST1N-224 evidently enhanced the susceptibility of VISA to both vancomycin and methicillin. Importantly, TST1N-224 distinguished by 1,2,5,6-tetrathiocane with the 3 and 8 positions modified with ethanesulfonates holds significant potential as a lead compound for the development of new antimicrobial agents.


Assuntos
Antibacterianos , Proteínas de Bactérias , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Staphylococcus aureus/efeitos dos fármacos , Descoberta de Drogas , Testes de Sensibilidade Microbiana , Avaliação Pré-Clínica de Medicamentos , Simulação de Acoplamento Molecular , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Modelos Moleculares , Farmacóforo
11.
J Med Internet Res ; 26: e53450, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39052335

RESUMO

BACKGROUND: Resilience is a protective factor in healthy aging, helping to maintain and recover physical and mental functions. The Resilience in Illness Model has proven effective in fostering resilience and well-being. Physical activity is crucial for older adults' independence and well-being, even as aging causes a progressive decline. Additionally, older adults face challenges such as spousal loss and physical disability, making preventive intervention strategies necessary. OBJECTIVE: This study aims to develop and evaluate a web-based program to enhance resilience, physical activity, and well-being among community-dwelling older adults. Additionally, we aim to gather feedback on the program's strengths and limitations. METHODS: A 4-week resilience-enhancing program was created, incorporating role-play and talk-in-interaction and focusing on 3 key skills: coping, control belief, and manageability. The program included scenarios such as becoming widowed and suffering a stroke, designed to engage older adults. A pilot test preceded the intervention. As a result of the COVID-19 pandemic, the program shifted from in-person to web-based sessions. A single-blind, parallel-group, randomized controlled trial was conducted. Participants aged over 65 years were recruited offline and randomly assigned to either an intervention or control group. A certified resilience practitioner delivered the program. Outcomes in resilience, physical activity, and well-being were self-assessed at baseline (T0), 4 weeks (T1), and 12 weeks (T2) after the program. A mixed methods approach was used to evaluate feedback. RESULTS: A web-based participatory program enhancing 3 skills-coping, control belief, and manageability for resilience-was well developed. Among 96 participants, 63 were randomized into the intervention group (n=31) and the control group (n=32). The mean age in the intervention group was 69.27 (SD 3.08) years and 74.84 (SD 6.23) years in the control group. Significant between-group differences at baseline were found in age (t45.6=-4.53, P<.001) and physical activity at baseline (t61=2.92, P=.005). No statistically significant between-group differences over time were observed in resilience (SE 7.49, 95% CI -10.74 to 18.61, P=.60), physical activity (SE 15.18, 95% CI -24.74 to 34.74, P=.74), and well-being (SE 3.74, 95% CI -2.68 to 11.98, P=.21) after controlling for baseline differences. The dropout rate was lower in the intervention group (2/31, 6%) compared with the control group (5/32, 16%). Moreover, 77% (24/31) of participants in the intervention group completed the entire program. Program feedback from the participants indicated high satisfaction with the web-based format and mentorship support. CONCLUSIONS: This study demonstrated that a web-based resilience-enhancing program is appropriate, acceptable, feasible, and engaging for community-dwelling older adults. The program garnered enthusiasm for its potential to optimize resilience, physical activity, and well-being, with mentorship playing a crucial role in its success. Future studies should aim to refine program content, engagement, and delivery methods to effectively promote healthy aging in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT05808491; https://clinicaltrials.gov/ct2/show/NCT05808491.


Assuntos
Exercício Físico , Resiliência Psicológica , Humanos , Idoso , Feminino , Exercício Físico/psicologia , Masculino , COVID-19/prevenção & controle , COVID-19/psicologia , Intervenção Baseada em Internet , Adaptação Psicológica , Idoso de 80 Anos ou mais , Internet , Método Simples-Cego
13.
Small ; 20(36): e2402314, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38708815

RESUMO

Topology serves as a blueprint for the construction of reticular structures such as metal-organic frameworks, especially for those based on building blocks with highly symmetrical shapes. However, it remains a challenge to predict the topology of the frameworks from less symmetrical units, because their corresponding vertex figures are largely deformed from the perfect geometries with no "default" net embedding. Furthermore, vertices involving flexible units may have multiple shape choices, and the competition among their designated topologies makes the structure prediction in large uncertainty. Herein, the deformation index is proposed to characterize the symmetry loss of the vertex figure by comparing it with its ideal geometry. The mathematical index is employed to predict the shapes of two in situ formed Co-based metalloligands (pseudo-tetrahedron and pseudo-square), which further dictate the framework topology (flu and scu) when they are joined with the [Zr6O8]-based cuboid units. The two frameworks with very similar constituents provide an ideal platform to investigate how the pore shapes and interconnectivity influence the gas separation. The net with cylindrical channels outperforms the other with discreate cages in C3H8/C2H6/CH4 separation, benefiting from the facile accessibility of its interaction sites to the guests imposed by the specific framework topology.

14.
Angew Chem Int Ed Engl ; 63(25): e202404732, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38605561

RESUMO

The catalytic access of silicon-stereogenic organosilanes remains a big challenge, and largely depends on the desymmetrization of the symmetric precursors with two identical substitutes attached to silicon atom. Here we report the construction of silicon-stereogenic organosilanes via catalytic kinetic resolution of racemic monohydrosilanes with good to excellent selectivity factors. Both Si-stereogenic dihydrobenzosiloles and Si-stereogenic monohydrosilanes could be efficiently accessed in one single operation via Rh-catalyzed enantioselective intramolecular hydrosilylation, employing (R,R)-Et-DuPhos as the optimal ligand. This catalytic protocol features mild conditions, a low catalyst loading (0.1 mol % [Rh(cod)Cl]2), high stereoinduction (S factor up to 152), and excellent scalability. Moreover, further derivatizations led to the efficient synthesis of uncommon middle-size (7- and 8-membered) Si-stereogenic silacycles. Preliminary mechanistic study indicates this reaction might undergo a modified Chalk-Harrod mechanism.

15.
Comput Struct Biotechnol J ; 23: 1477-1488, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38623562

RESUMO

Mycobacteria are causative agents of tuberculosis (TB), which is a global health concern. Drug-resistant TB strains are rapidly emerging, thereby necessitating the urgent development of new drugs. Two-component signal transduction systems (TCSs) are signaling pathways involved in the regulation of various bacterial behaviors and responses to environmental stimuli. Applying specific inhibitors of TCSs can disrupt bacterial signaling, growth, and virulence, and can help combat drug-resistant TB. We conducted a comprehensive pharmacophore-based inhibitor screening and biochemical and biophysical examinations to identify, characterize, and validate potential inhibitors targeting the response regulators PhoP and MtrA of mycobacteria. The constructed pharmacophore model Phar-PR-n4 identified effective inhibitors of formation of the PhoP-DNA complex: ST132 (IC50 = 29 ± 1.6 µM) and ST166 (IC50 = 18 ± 1.3 µM). ST166 (KD = 18.4 ± 4.3 µM) and ST132 (KD = 14.5 ± 0.1 µM) strongly targeted PhoP in a slow-on, slow-off manner. The inhibitory potency and binding affinity of ST166 and ST132 for MtrAC were comparable to those of PhoP. Structural analyses and molecular dynamics simulations revealed that ST166 and ST132 mainly interact with the α8-helix and C-terminal ß-hairpin of PhoP, with functionally essential residue hotspots for structure-based inhibitor optimization. Moreover, ST166 has in vitro antibacterial activity against Macrobacterium marinum. Thus, ST166, with its characteristic 1,2,5,6-tetrathiocane and terminal sulphonic groups, has excellent potential as a candidate for the development of novel antimicrobial agents to combat pathogenic mycobacteria.

16.
Org Lett ; 26(18): 3691-3696, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38662519

RESUMO

O-Acylhydroxylamine has been widely employed as an electrophilic amination reagent in transition-metal-catalyzed C-N coupling reactions, but its use as an electrophilic oxygen source has not been disclosed. Here, we report a Pd-catalyzed 1,2-oxyarylation of alkenes with O-acylhydroxylamines as an oxidant and an oxygen source for the first time. With simple amide as the monodentate directing group, this method features a broad substrate scope, good functional group tolerance, and mild conditions.

17.
Virus Res ; 344: 199359, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38521505

RESUMO

The heightened transmissibility and capacity of African swine fever virus (ASFV) induce fatal diseases in domestic pigs and wild boars, posing significant economic repercussions and global threats. Despite extensive research efforts, the development of potent vaccines or treatments for ASFV remains a persistent challenge. Recently, inhibiting the AsfvPolX, a key DNA repair enzyme, emerges as a feasible strategy to disrupt viral replication and control ASFV infections. In this study, a comprehensive approach involving pharmacophore-based inhibitor screening, coupled with biochemical and biophysical analyses, were implemented to identify, characterize, and validate potential inhibitors targeting AsfvPolX. The constructed pharmacophore model, Phar-PolX-S, demonstrated efficacy in identifying a potent inhibitor, D-132 (IC50 = 2.8 ± 0.2 µM), disrupting the formation of the AsfvPolX-DNA complex. Notably, D-132 exhibited strong binding to AsfvPolX (KD = 6.9 ± 2.2 µM) through a slow-on-fast-off binding mechanism. Employing molecular modeling, it was elucidated that D-132 predominantly binds in-between the palm and finger domains of AsfvPolX, with crucial residues (R42, N48, Q98, E100, F102, and F116) identified as hotspots for structure-based inhibitor optimization. Distinctively characterized by a 1,2,5,6-tetrathiocane with modifications at the 3 and 8 positions involving ethanesulfonates, D-132 holds considerable promise as a lead compound for the development of innovative agents to combat ASFV infections.


Assuntos
Vírus da Febre Suína Africana , Antivirais , DNA Polimerase Dirigida por DNA , Vírus da Febre Suína Africana/efeitos dos fármacos , Vírus da Febre Suína Africana/genética , Vírus da Febre Suína Africana/química , Animais , Antivirais/farmacologia , Antivirais/química , Febre Suína Africana/virologia , Suínos , Descoberta de Drogas , Replicação Viral/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ligação Proteica , Simulação de Acoplamento Molecular , DNA Viral/genética , Farmacóforo
18.
Angew Chem Int Ed Engl ; 63(20): e202402612, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38410071

RESUMO

The construction of silicon-stereogenic silanols via Pd-catalyzed intermolecular C-H alkenylation with the assistance of a commercially available L-pyroglutamic acid has been realized for the first time. Employing oxime ether as the directing group, silicon-stereogenic silanol derivatives could be readily prepared with excellent enantioselectivities, featuring a broad substrate scope and good functional group tolerance. Moreover, parallel kinetic resolution with unsymmetric substrates further highlighted the generality of this protocol. Mechanistic studies indicate that L-pyroglutamic acid could stabilize the Pd catalyst and provide excellent chiral induction. Preliminary computational studies unveil the origin of the enantioselectivity in the C-H bond activation step.

19.
Light Sci Appl ; 13(1): 51, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38374124

RESUMO

Harnessing optical supermode interaction to construct artificial photonic molecules has uncovered a series of fundamental optical phenomena analogous to atomic physics. Previously, the distinct energy levels and interactions in such two-level systems were provided by coupled microresonators. The reconfigurability is limited, as they often require delicate external field stimuli or mechanically altering the geometric factors. These highly specific approaches also limit potential applications. Here, we propose a versatile on-chip photonic molecule in a multimode microring, utilizing a flexible regulation methodology to dynamically control the existence and interaction strength of spatial modes. The transition between single/multi-mode states enables the "switched-off/on" functionality of the photonic molecule, supporting wider generalized applications scenarios. In particular, "switched-on" state shows flexible and multidimensional mode splitting control in aspects of both coupling strength and phase difference, equivalent to the a.c. and d.c. Stark effect. "Switched-off" state allows for perfect low-loss single-mode transition (Qi ~ 10 million) under an ultra-compact bend size (FSR ~ 115 GHz) in a foundry-based silicon microring. It breaks the stereotyped image of the FSR-Q factor trade-off, enabling ultra-wideband and high-resolution millimeter-wave photonic operations. Our demonstration provides a flexible and portable solution for the integrated photonic molecule system, extending its research scope from fundamental physics to real-world applications such as nonlinear optical signal processing and sixth-generation wireless communication.

20.
Am J Intellect Dev Disabil ; 129(2): 151-168, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38411244

RESUMO

Using National Longitudinal Transition Study 2012 data, this study explored parent and youth expectations in the areas of postsecondary education, employment, independent living, and financial independence. Compared to youth with other disabilities, youth with intellectual and developmental disabilities and their parents had much lower expectations for the four postschool goals, and parent expectations were much lower than youth's own expectations. Also, youth's race, along with their daily living skills and functional abilities, were positively associated with parent and youth expectations in several future goal areas. Our discussion highlights implications for improving the transition experiences of youth with intellectual and developmental disabilities.


Assuntos
Deficiência Intelectual , Motivação , Criança , Humanos , Adolescente , Objetivos , Deficiências do Desenvolvimento , Pais , Emprego
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