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1.
J Org Chem ; 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39094225

RESUMO

Oxetane has been extensively studied for its applications in medicinal chemistry and as a reactive intermediate in synthesis. Experiments report a Cu-catalyzed [2 + 2] photocycloaddition of acetone and norbornene to oxetane, which is proposed to deviate from the conventional Paternò-Büchi reaction. However, its mechanism at the atomic level is not clear. In this study, we used a combination of multistate complete active space second-order perturbation theory (MS-CASPT2) and density functional theory to systematically investigate the reaction mechanism and elucidate the factors contributing to the diastereomeric selectivity. Initially, the formation of the TpCu(Norb) complex is achieved by strong interaction between tris(pyrazolyl)borate Cu(I) (TpCu) and norbornene in the ground state (S0). Upon photoexcitation, TpCu(Norb) eventually decays to the T1 state, in which TpCu(Norb) attacks acetone to initiate subsequent reactions and produces final endo- or exo-oxetane products. All these reactions initially involve the C-C bond formation in the T1 state thereto leading to a ring-opening intermediate. This intermediate then undergoes a nonradiative transition to the S0 state, producing a five-membered ring intermediate, from which the C-O bond is formed, leading to the experimentally dominant exo-product. In contrast, the endo-oxetane formation requires a rearrangement process after the C-C bond is formed because of the large steric effects. As a consequence, the different reaction pathways generating exo- and endo-products exhibit large differences in the free-energy barriers, which results in a diastereomeric selectivity observed experimentally. Additionally, the nonradiative transition is found to play an important role in facilitating these reaction steps. The present computational study provides valuable mechanistic insights into Cu-catalyzed photocycloaddition reactions.

2.
J Cardiothorac Surg ; 19(1): 478, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39090722

RESUMO

BACKGROUND: Combining pemetrexed with bevacizumab may have some potential in improving the efficacy in patients with non-small-cell lung cancer (NSCLC), and this meta-analysis aims to explore the impact of pemetrexed addition to bevacizumab on treatment efficacy for NSCLC. METHODS: PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched, and we included randomized controlled trials (RCTs) assessing the effect of pemetrexed addition to bevacizumab on treatment efficacy in patients with NSCLC. Overall survival and progression-free survival were included in this meta-analysis. RESULTS: Four RCTs were finally included in the meta-analysis. Overall, compared with bevacizumab for NSCLC, pemetrexed addition showed significantly improved overall survival (hazard ratio [HR] = 0.87; 95% confidence interval [CI] = 0.76 to 0.99; P = 0.03), survival rate (odd ratio [OR] = 1.41; 95% CI = 1.06 to 1.86; P = 0.02), progression-free survival (HR = 0.63; 95% CI = 0.55 to 0.72; P < 0.00001) and progression-free survival rate (OR = 1.92; 95% CI = 1.38 to 2.67; P < 0.00001), but led to the increase in grade ≥ 3 adverse events (OR = 2.15; 95% CI = 1.62 to 2.84; P < 0.00001). CONCLUSIONS: Pemetrexed addition may be effective to improve treatment efficacy for NSCLC compared to bevacizumab treatment.


Assuntos
Bevacizumab , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Pemetrexede , Pemetrexede/uso terapêutico , Pemetrexede/administração & dosagem , Humanos , Bevacizumab/uso terapêutico , Bevacizumab/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Aesthetic Plast Surg ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048770

RESUMO

BACKGROUND: Lip filler injection is one of the most common minimally invasive cosmetic procedures involving the face; however, vascular complications are not uncommon. The aim of this study was to investigate the anatomy of the superior labial artery (SLA) and provide precise topographic information for dermal filler injection into the lips. METHODS: Computed tomography (CT) scans of 52 cadaveric heads injected with lead oxide were obtained. We then used Mimics software to construct 3D images of the SLA described by a coordinate system based on the bilateral external auditory canal and the left orbit. This study aimed to classify the SLA in the Han Chinese population, measure its diameter at specific points, and determine the thickness of the lip at those points. Ultimately, we utilized a thermal imaging technique to illustrate the course and depth of the SLA within the lip. The objective of this study was to provide safe guidance for clinical injections. RESULTS: In this study, the SLA was successfully identified in all cadavers. The mean overall diameter of the superior labial arteries was 1.36 ± 0.28 mm. The superior labial artery showed a general course from deep to shallow with an average depth of 5.68 ± 1.68 mm from the oral commissure to the midline. CONCLUSIONS: There are anatomical differences in the superior labial arteries among Chinese people. Furthermore, 3D CT images can digitally elucidate the exact positions of the superior labial artery via a coordinate system, improving the safety of upper lip filler injections in clinical settings. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

4.
J Am Chem Soc ; 146(29): 20494-20499, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39001838

RESUMO

The photochemistry of nitrous acid (HONO), encompassing dissociation into OH and NO as well as the reverse association reaction, plays a pivotal role in atmospheric chemistry. Here, we report the direct observation of nitrosyl-O-hydroxide (HOON) in the photochemistry of HONO, employing matrix-isolation IR and UV-vis spectroscopy. Despite a barrier of approximately 30 kJ/mol, HOON undergoes spontaneous rearrangement to the more stable HONO isomer through quantum mechanical tunneling, with a half-life of 28 min at 4 K. Kinetic isotope effects and instanton theory calculations reveal that the tunneling process involves the concerted motion of the NO moiety (65.2%) and the hydrogen atom (32.3%). Our findings underscore the significance of HOON as a key intermediate in the photolytic dissociation-association cycle of HONO at low temperatures.

5.
Adv Physiol Educ ; 48(3): 603-608, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39042766

RESUMO

Cohort scheduling intentionally places students in the same sections of several classes (e.g., biology, algebra, and writing) with a consistent peer group and is typically done for small groups (<30 students) to enable better interaction among students. The goal of this study was to compare cohort scheduling to traditional scheduling methods among freshmen in a physiology-related program. Outcomes included retention to the university and major, semester grades, and institutional integration and perceived group cohesion. Incoming freshmen (n = 209) were randomized into control (n = 43; scheduled with traditional methods) and intervention (n = 166; coenrolled in first-year seminar course, biology, and medical terminology) groups. Outcomes were collected via surveys or requested from the university registrar. There was no significant difference in the likelihood of retention to the university or major and no differences between groups in pass/fail rates for the first-year seminar or biology courses. At the end of the semester, there were no differences between groups in Perceived Cohesion for Small Groups (P = 0.102) or the Institutional Integration Scale (P = 0.357). However, the intervention group scored higher on the Institutional Integration Scale's subscales related to social integration and faculty. Cohort scheduling did not impact retention to the university or major but improved secondary outcomes related to retention, specifically social integration and student perceptions of faculty.NEW & NOTEWORTHY Compared with traditional scheduling methods, cohort scheduling freshman in physiology programs does not improve retention but improves students' social integration and perceptions of faculty.


Assuntos
Fisiologia , Humanos , Fisiologia/educação , Feminino , Masculino , Desempenho Acadêmico , Docentes , Exercício Físico/fisiologia , Adulto Jovem , Universidades , Estudantes/psicologia , Estudos de Coortes
6.
Perioper Med (Lond) ; 13(1): 84, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39054562

RESUMO

BACKGROUND: With the popularization of robotic surgical systems in the field of surgery, robotic gastric cancer surgery has also been fully applied and promoted in China. The Chinese Guidelines for Robotic Gastric Cancer Surgery was published in the Chinese Journal of General Surgery in August 2021. METHODS: We have made a detailed interpretation of the process of robotic gastric cancer surgery regarding the indications, contraindications, perioperative preparation, surgical steps, complication, and postoperative management based on the recommendations of China's Guidelines for Robotic Gastric Cancer Surgery and supplemented by other surgical guidelines, consensus, and single-center experience. RESULTS: Twenty experiences of perioperative clinical management of robotic gastric cancer surgery were described in detail. CONCLUSION: We hope to bring some clinical reference values to the front-line clinicians in treating robotic gastric cancer surgery. TRIAL REGISTRATION: The guidelines were registered on the International Practice Guideline Registration Platform ( http://www.guidelines-registry.cn ) (registration number: IPGRP-2020CN199).

7.
Int J Pharm ; 662: 124472, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39013532

RESUMO

Adequate stabilization is essential for marketed protein-based biopharmaceutical formulations to withstand the various stresses that can be exerted during the pre- and post-manufacturing processes. Therefore, a suitable choice of excipient is a significant step in the manufacturing of such delicate products. Histidine, an essential amino acid, has been extensively used in protein-based biopharmaceutical formulations. The physicochemical properties of histidine are unique among amino acids and could afford multifaceted benefits to protein-based biopharmaceutical formulations. With a pKa of approximately 6.0 at the side chain, histidine has been primarily used as a buffering agent, especially for pH 5.5-6.5. Additionally, histidine exhibited several affirmative properties similar to those of carbohydrates (e.g., sucrose and trehalose) and could therefore be considered to be an alternative approach to established protein-based formulation strategies. The current review describes the general physicochemical properties of histidine, lists all commercial histidine-containing protein-based biopharmaceutical products, and discusses a brief outline of the existing research focused on the versatile applications of histidine, which can act as a buffering agent, stabilizer, cryo-/lyo-protectant, antioxidant, viscosity reducer, and solubilizing agent. The interaction between histidine and proteins in protein-based biopharmaceutical formulations, such as the Donnan effect during diafiltration of monoclonal antibody solutions and the degradation of polysorbates in histidine buffer, has also been discussed. As the first review of histidine in protein biopharmaceuticals, it helps to deepen our understanding of the opportunities and challenges associated with histidine as an excipient for protein-based biopharmaceutical formulations.

8.
Chem Commun (Camb) ; 60(59): 7574-7577, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38952177

RESUMO

Presented herein is a series of chain compounds based on pre-designed heterometallic aluminum-lanthanide (Al-Ln) Al4Ln4 molecular rings. Their photoluminescence quantum yield (PLQY) with Eu3+ (30.41%) and Tb3+ (41.44%) is at a high level among the clusters containing four Ln ions. This study significantly extends the family of Al-Ln heterometallic clusters and demonstrates the synergistic effect of heterometallic ions in enhancing their properties.

9.
J Phys Chem A ; 128(28): 5516-5524, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38954640

RESUMO

Machine learning is capable of effectively predicting the potential energies of molecules in the presence of high-quality data sets. Its application in the construction of ground- and excited-state potential energy surfaces is attractive to accelerate nonadiabatic molecular dynamics simulations of photochemical reactions. Because of the huge computational cost of excited-state electronic structure calculations, the construction of a high-quality data set becomes a bottleneck. In the present work, we first built two data sets. One was obtained from surface hopping dynamics simulations at the semiempirical OM2/MRCI level. Another was extracted from the dynamics trajectories at the CASSCF level, which was reported previously. The ground- and excited-state potential energy surfaces of ethylene-bridged azobenzene at the CASSCF computational level were constructed based on the former low-level data set. Although non-neural network machine learning methods can achieve good or modest performance during the training process, only neural network models provide reliable predictions on the latter external test data set. The BPNN and SchNet combined with the Δ-ML scheme and the force term in the loss functions are recommended for dynamics simulations. Then, we performed excited-state dynamics simulations of the photoisomerization of ethylene-bridged azobenzene on machine learning potential energy surfaces. Compared with the lifetimes of the first excited state (S1) estimated at different computational levels, our results on the E isomer are in good agreement with the high-level estimation. However, the overestimation of the Z isomer is unimproved. It suggests that smaller errors during the training process do not necessarily translate to more accurate predictions on high-level potential energies or better performance on nonadiabatic dynamics simulations, at least in the present case.

10.
Chem Commun (Camb) ; 60(59): 7638-7641, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38963238

RESUMO

The versatile reactivity of isothiocyanate intermediates enabled the diversity-oriented synthesis (DOS) of N-heterocycles in a DNA-compatible manner. We first reported a mild in situ conversion of DNA-conjugated amines to isothiocyanates. Subsequently, a set of diverse transformations was successfully developed to construct 2-thioxo-quinazolinones, 1,2,4-thiadiazoles, and 2-imino thiazolines. Finally, the feasibility of these approaches in constructing DELs was further demonstrated through enzymatic ligation and mock pool preparation. This study demonstrated the advantages of combining in situ conversion strategies with DOS, which effectively broadened the chemical and structural diversity of DELs.


Assuntos
DNA , Compostos Heterocíclicos , Isotiocianatos , Isotiocianatos/química , DNA/química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Estrutura Molecular , Aminas/química , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/síntese química
11.
J Phys Chem Lett ; 15(28): 7244-7253, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38976358

RESUMO

Conical intersections (CIs) are pivotal in many photochemical processes. Traditional quantum chemistry methods, such as the state-average multiconfigurational methods, face computational hurdles in solving the electronic Schrödinger equation within the active space on classical computers. While quantum computing offers a potential solution, its feasibility in studying CIs, particularly on real quantum hardware, remains largely unexplored. Here, we present the first successful realization of a hybrid quantum-classical state-average complete active space self-consistent field method based on the variational quantum eigensolver (VQE-SA-CASSCF) on a superconducting quantum processor. This approach is applied to investigate CIs in two prototypical systems─ethylene (C2H4) and triatomic hydrogen (H3). We illustrate that VQE-SA-CASSCF, coupled with ongoing hardware and algorithmic enhancements, can lead to a correct description of CIs on existing quantum devices. These results lay the groundwork for exploring the potential of quantum computing to study CIs in more complex systems in the future.

12.
Dev Psychobiol ; 66(6): e22525, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38988125

RESUMO

Motor experiences shape cognitive development in infancy, with the prone position being one such crucial motor experience in the first 6 months of life. Although the motor benefits of the prone position are well-documented, its influence on early cognitive abilities remains insufficiently explored. This study quantified the relationship between prone motor skills and motor-based problem-solving abilities in 48 full-term and preterm infants aged 3-6 months. Prone skills were assessed using the Alberta Infant Motor Scale's prone domain. The Assessment of Problem-Solving in Play was utilized to measure motor-based problem-solving by observing how motor actions were used to solve toys. Advanced prone motor skills were correlated with an increase in sophisticated exploration skills and a concurrent decline in lower order exploration skills in all infants, with correlations being stronger in preterm infants. Notably, a 1-point increase in prone skills was associated with a 1.3-point increase in total motor-based problem-solving abilities in all infants. Our findings provide preliminary evidence for the contribution of prone play to cognitive development in infants, prompting considerations for assessment and intervention strategies. Further research is needed to ascertain if the delayed acquisition of prone motor skills is indicative of poor early problem-solving abilities in preterm infants.


Assuntos
Desenvolvimento Infantil , Recém-Nascido Prematuro , Destreza Motora , Resolução de Problemas , Humanos , Resolução de Problemas/fisiologia , Destreza Motora/fisiologia , Recém-Nascido Prematuro/fisiologia , Masculino , Feminino , Decúbito Ventral/fisiologia , Desenvolvimento Infantil/fisiologia , Lactente , Recém-Nascido
13.
J Am Chem Soc ; 146(28): 19547-19554, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38976802

RESUMO

We simulated hot-electron relaxation in black phosphorus using the nonadiabatic molecular dynamics (NA-MD) approach with a non-Condon effect in momentum space beyond the harmonic approximation. By comparing simulations at the Γ point in a large supercell with those using a few k-points in a smaller supercell─while maintaining the same number of electronic states within the same energy range, we demonstrate that both setups yield remarkably consistent energy relaxation times, regardless of the initial state energy. This consistency arises from the complementary effects of supercell size in real space and the number of k-points in the reciprocal space. This finding confirms that simulations at a single k-point in large size supercells are an effective approximation for NA-MD with a non-Condon effect. This approach offers significant advantages for complex photophysics, such as intervalley scattering and indirect bandgap charge recombination, and is particularly suitable for large systems without the need for a harmonic approximation.

14.
Nat Chem Biol ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039255

RESUMO

The phosphoinositide 3-kinase (PI3K)-Akt axis is one of the most frequently activated pathways and is demonstrated as a therapeutic target in Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated colorectal cancer (CRC). Targeting the PI3K-Akt pathway has been a challenging undertaking through the decades. Here we unveiled an essential role of E3 ligase SMAD ubiquitylation regulatory factor 1 (Smurf1)-mediated phosphoinositide-dependent protein kinase 1 (PDK1) neddylation in PI3K-Akt signaling and tumorigenesis. Upon growth factor stimulation, Smurf1 immediately triggers PDK1 neddylation and the poly-neural precursor cell expressed developmentally downregulated protein 8 (poly-Nedd8) chains recruit methyltransferase SET domain bifurcated histone lysine methyltransferase 1 (SETDB1). The cytoplasmic complex of PDK1 assembled with Smurf1 and SETDB1 (cCOMPASS) consisting of PDK1, Smurf1 and SETDB1 directs Akt membrane attachment and T308 phosphorylation. Smurf1 deficiency dramatically reduces CRC tumorigenesis in a genetic mouse model. Furthermore, we developed a highly selective Smurf1 degrader, Smurf1-antagonizing repressor of tumor 1, which exhibits efficient PDK1-Akt blockade and potent tumor suppression alone or combined with PDK1 inhibitor in KRAS-mutated CRC. The findings presented here unveil previously unrecognized roles of PDK1 neddylation and offer a potential strategy for targeting the PI3K-Akt pathway and KRAS mutant cancer therapy.

15.
Dis Model Mech ; 2024 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-38973385

RESUMO

Despite advancements in treatment, approximately 25% of breast cancer patients experience long-term skeletal muscle wasting (SMW), which limits mobility, reduces drug tolerance and adversely impacts survival. By understanding the underlying molecular mechanisms of SMW, we may develop new strategies to alleviate this condition and improve the lives of breast cancer patients. Chemokines are small soluble factors that regulate homing of immune cells to tissues during inflammation. In breast cancers, overexpression of the C-C chemokine ligand 2 (CCL2) correlates with unfavorable prognosis. Elevated levels of CCL2 in peripheral blood indicate possible systemic effects of this chemokine in breast cancer patients. Here, we investigated the role of CCL2 signaling on SMW in a tumor and non-tumor context. In vitro, increasing concentrations of CCL2 inhibits myoblast and myotube function through C-C chemokine receptor 2 (CCR2) dependent mechanisms involving JNK, SMAD3 and AMPK signaling. In healthy mice, delivery of recombinant CCL2 protein promotes SMW in a dose dependent manner. In vivo knockdown of breast tumor derived CCL2 partially protects against SMW. Overall, chronic, upregulated CCL2/CCR2 signaling positively regulates SMW, with implications on therapeutic targeting.

16.
Heliyon ; 10(12): e33061, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38988542

RESUMO

Transcatheter aortic valve implantation (TAVI) was originally devised as a treatment for patients with aortic stenosis (AS). It has since emerged as a beneficial alternative to surgical aortic valve replacement (SAVR), extending its reach to a broader array of patients. Our objective was to illustrate the developmental trends and focus areas in TAVI research. We sourced a total of 11,480 research papers on TAVI, published between 1994 and 2022, from the Web of Science Core Collection (WoSCC) database. We conducted a bibliometric analysis of these publications, generating cooperation maps, performing co-citation analysis of journals and references, and carrying out a cluster analysis of keywords. Our findings indicate that TAVI research grapples with numerous clinical challenges. We created knowledge maps that highlight contributing countries/institutions, authors, journals with high publication and citation rates, and notable references in this domain. North America and Europe have been at the forefront of research within the TAVI field. The institutions and authors from these regions exert significant influence in this area of study. Beginning in 2009, China has progressively expanded its research on TAVI over the past two decades. We anticipate that future research will increasingly focus on three key areas: implementation scope, lifelong management, outcomes and predicting the risk of TAVI. Research on TAVI is flourishing. Cooperation among different countries and institutions in this field must be strengthened in the future, especially for developing counties.

17.
Br J Cancer ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39026081

RESUMO

BACKGROUND: Studies have shown that hepatitis B virus (HBV)-associated B-cell non-Hodgkin lymphoma (NHL) constitutes a unique subgroup with distinct clinical features. It still leaves open the question of whether the integration of HBV DNA into the B-cell genome is a causal mechanism in the development of lymphoma. METHODS: Using the hybridisation capture-based next generation sequencing and RNA sequencing, we characterised the HBV integration pattern in 45 HBV-associated B-cell NHL tumour tissues. RESULTS: A total of 354 HBV integration sites were identified in 13 (28.9%) samples, indicating the relatively low integration frequency in B-cell NHLs. High plasma HBV DNA loads were not associated with the existence of HBV integration. The insertion sites distributed randomly across all the lymphoma genome without any preferential hotspot neither at the chromosomal level nor at the genetic level. Intriguingly, most HBV integrations were nonclonal in B-cell NHLs, implying that they did not confer a survival advantage. Analysis of the paired diagnosis-relapse samples showed the unstable status of HBV integrations during disease progression. Furthermore, transcriptomic analysis revealed the limited biological impact of HBV integration. CONCLUSION: Our study provides an unbiased HBV integration map in B-cell NHLs, revealing the insignificant role of HBV DNA integration in B-cell lymphomagenesis.

18.
Oncol Rep ; 52(3)2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38963043

RESUMO

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that there appeared to be two instances of overlapping data panels comparing between the cell migration and invasion assay data shown in Figs. 4 and 6 on p. 143 and 145, respectively, such that data which were intended to represent the results from differently performed experiments had apparently been derived from the same original sources. In addition, the authors themselves realized that incorrect western blotting data for Snail protein in Fig. 10A on p. 147 had been included in the figure.  The authors were able to re­examine their original data files, and realized that the affected data panels in these figures had inadvertently been incorporated into them incorrectly. The revised versions of Figs. 4, 6, and 10, featuring the correct data for the 'NC / Control' panels in Fig. 4B and C and the 'siRNA2 / ATP 12 h' panels in Fig. 4A and B, a replacement data panel for the 'siRNA1 / Control' experiment in Fig. 6, and the correct western blotting data for Snail protein in Fig. 10A (together with a revised histogram for the MCF7 cell line relating to Fig. 10A) are shown on the next three pages. The authors wish to emphasize that the errors made in compiling these figures did not affect the overall conclusions reported in the paper, and they are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this corrigendum. All the authors agree to the publication of this corrigendum, and also apologize to the readership for any inconvenience caused. [Oncology Reports 39: 138­150, 2018; DOI: 10.3892/or.2017.6081].

19.
Nat Commun ; 15(1): 5792, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987247

RESUMO

The construction of a large-scale quantum internet requires quantum repeaters containing multiple entangled photon sources with identical wavelengths. Semiconductor quantum dots can generate entangled photon pairs deterministically with high fidelity. However, realizing wavelength-matched quantum-dot entangled photon sources faces two difficulties: the non-uniformity of emission wavelength and exciton fine-structure splitting induced fidelity reduction. Typically, these two factors are not independently tunable, making it challenging to achieve simultaneous improvement. In this work, we demonstrate wavelength-tunable entangled photon sources based on droplet-etched GaAs quantum dots through the combined use of AC and quantum-confined Stark effects. The emission wavelength can be tuned by ~1 meV while preserving an entanglement fidelity f exceeding 0.955(1) in the entire tuning range. Based on this hybrid tuning scheme, we finally demonstrate multiple wavelength-matched entangled photon sources with f > 0.919(3), paving the way towards robust and scalable on-demand entangled photon sources for quantum internet and integrated quantum optical circuits.

20.
Angew Chem Int Ed Engl ; : e202411576, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38984566

RESUMO

Mechanically interlocked molecules, such as rotaxanes, have drawn significant attention within supramolecular chemistry. Although a variety of macrocycles have been thoroughly explored in rotaxane synthesis, metal-organic macrocycles remain relatively under-investigated. Aluminum molecular rings, with their inner cavities and numerous binding sites, present a promising option for constructing rotaxanes. Here, we introduce an innovative "ring-donor···axle-acceptor" motif utilizing Al8 molecular rings, enabling the stepwise assembly of molecules, complexes, and polymers through tailored coordination chemistry. This novel approach can not only be applied to macrocycle-based systems like catenanes but also enhance specific functionalities progressively.

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