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1.
Org Lett ; 26(14): 2811-2816, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38227838

RESUMEN

Herein we have developed a highly practical and efficient one-step coupling protocol for the synthesis of chiral spiro diphosphine ligands, especially for the oxa-spiro diphosphine ligands O-SDP, which showed excellent reactivity and diastereoselectivity in the asymmetric hydrogenation of a key intermediate of Sacubitril. It should be noted that the one-step coupling protocol could be operated on a kilogram scale, and the resulting ruthenium catalyst of O-SDP could hydrogenate the key intermediate of Sacubitril on an industrial scale.

2.
J Org Chem ; 89(1): 527-533, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38095905

RESUMEN

Transition metal catalysts with a million turnovers and excellent selectivity are rarely reported but are crucial for the industrial manufacture of optical pure pharmaceuticals, natural products, and fine chemicals. In this paper, we report an unprecedented aninoic Ir-f-phamidol catalyst for asymmetric hydrogenation of γ-amino ketones followed by stereoselective cyclization for construction of valuable chiral 2-aryl-pyrrolidine pharmacophores. The Ir-f-phamidol catalyst showed up to 1,000,000 TON and >99% ee, as well as excellent tolerance of substrates and protecting groups, providing various chiral amino alcohol intermediates. Upon optimization of the conditions, the stereoselective cyclization reaction was highly smooth and efficient (quantitative conversions, 92 to >99% ee). Finally, this solution was applied in the preparation of high-value chiral entities containing such chiral 2-aryl-pyrrolidine pharmacophores.

3.
PeerJ ; 11: e15704, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37483959

RESUMEN

Volunteers played an important role throughout the COVID-19 pandemic. This study investigated the characteristics of perceived stress, psychological resilience and work engagement among 910 Chinese volunteers of different ages in the first month of pandemic in Gansu province, China. The present study tested the correlations between perceived stress and work engagement, the mediating role of psychological resilience in the relationship and the differences among age groups. The results of this study showed that work engagement and psychological resilience increased with the age of the volunteers. Work engagement and resilience levels were higher in middle adulthood than in early adulthood. As predicted, perceived stress negatively predicted work engagement. A mediation analysis showed that psychological resilience partially explained the correlations between perceived stress and work engagement. Specifically, the mediating effect of psychological resilience in early adulthood was significant, but not in middle adulthood. Overall, this study demonstrates that work engagement increased with age and was negatively predicted by perceived stress, showing these factors were important for volunteers' work during COVID-19. Further, for those in early adulthood, psychological resilience mediated this relationship-highlighting another age difference among volunteers during COVID-19.


Asunto(s)
COVID-19 , Estrés Laboral , Resiliencia Psicológica , Adulto , Humanos , Persona de Mediana Edad , Pandemias , Voluntarios , Compromiso Laboral , Adulto Joven
4.
Nat Commun ; 14(1): 3718, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37349291

RESUMEN

Developing catalysts with both useful enantioselectivities and million turnover numbers (TONs) for asymmetric hydrogenation of ketones is attractive for industrial production of high-value bioactive chiral entities but remains a challenging. Herein, we report an ultra-efficient anionic Ir-catalyst integrated with the concept of multidentate ligation for asymmetric hydrogenation of ketones. Biocatalysis-like efficacy of up to 99% ee (enantiomeric excess), 13,425,000 TON (turnover number) and 224 s-1 TOF (turnover frequency) were documented for benchmark acetophenone. Up to 1,000,000 TON and 99% ee were achieved for challenging pyridyl alkyl ketone where at most 10,000 TONs are previously reported. The anionic Ir-catalyst showed a novel preferred ONa/MH instead of NNa/MH bifunctional mechanism. A selective industrial route to enantiopure nicotine has been established using this anionic Ir-catalyst for the key asymmetric hydrogenation step at 500 kg batch scale, providing 40 tons scale of product.


Asunto(s)
Cetonas , Nicotina , Catálisis , Biocatálisis , Hidrogenación
5.
Sci Rep ; 12(1): 18896, 2022 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-36344573

RESUMEN

People more accurately remember faces of their own racial group compared to faces of other racial groups; this phenomenon is called the other-race effect. To date, numerous researchers have devoted themselves to exploring the reasons for this other-race effect, and they have posited several theoretical explanations. One integrated explanation is the categorization-individuation model, which addresses two primary ways (categorization and individuation) of racial face processing and emphasizes the emergence of these two ways during the encoding stage. Learning-recognition and racial categorization tasks are two classical tasks used to explore racial face processing. Event-related potentials can facilitate investigation of the encoding differences of own- and other-race faces under these two typical task demands. Unfortunately, to date, results have been mixed. In the current study, we investigated whether categorization and individuation differ for own- and other-race faces during the encoding stage by using racial categorization and learning-recognition tasks. We found that task demands not only influence the encoding of racial faces, but also have a more profound effect in the encoding stage of recognition tasks for other-race faces. More specifically, own-race faces demonstrate deeper structural encoding than other-race faces, with less attentional involvement. Moreover, recognitions tasks might ask for more individual-level encoding, requiring more attentional resources in the early stage that may be maintained until relatively late stages. Our results provide some evidence concerning task selection for future racial face studies and establish a groundwork for a unified interpretation of racial face encoding.


Asunto(s)
Reconocimiento Facial , Población Blanca , Humanos , Reconocimiento en Psicología , Potenciales Evocados , Grupos Raciales , Reconocimiento Visual de Modelos
6.
Mol Neurobiol ; 59(11): 6652-6665, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35982279

RESUMEN

Pamiparib is a poly ADP-ribose polymerase (PARP) inhibitor used in clinical studies, which can penetrate the blood-brain barrier efficiently. At present, there are few studies on its effect on vertebrate neurodevelopment. In this study, we exposed zebrafish embryos to 1, 2 and 3 µM of Pamiparib from 6 to 72 h post-fertilisation (hpf). Results showed that pamiparib can specifically induce cerebral haemorrhage, brain atrophy and movement disorders in fish larvae. In addition, pamiparib exposure leads to downregulation of acetylcholinesterase (AChE) and adenosine triphosphate (ATPase) activities, and upregulation of oxidative stress which then leads to apoptosis and disrupts the gene expression involved in the neurodevelopment, neurotransmitter pathways and Parkinson's disease (PD) like symptoms. Meanwhile, astaxanthin can partially rescue neurodevelopmental defects by downregulating oxidative stress. After exposure to pamiparib, the Notch signalling is downregulated, and the use of an activator of Notch signalling can partially rescue neurodevelopmental toxicity. Therefore, our research indicates that pamiparib may induce zebrafish neurotoxicity by downregulating Notch signalling and provides a reference for the potential neurotoxicity of pamiparib during embryonic development.


Asunto(s)
Embrión no Mamífero , Pez Cebra , Acetilcolinesterasa/metabolismo , Adenosina Difosfato Ribosa/metabolismo , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Hemorragia Cerebral/metabolismo , Embrión no Mamífero/metabolismo , Fluorenos , Larva , Estrés Oxidativo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Pez Cebra/metabolismo
7.
Skin Res Technol ; 27(5): 789-796, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33651469

RESUMEN

BACKGROUND: This study used laser speckle contrast imaging (LSCI) to evaluate the difference in blood perfusion between hypertrophic scars and keloids. MATERIALS AND METHODS: A total of 30 keloids, 21 early hypertrophic scars, 20 proliferative hypertrophic scars, 20 regressive hypertrophic scars, and 20 mature hypertrophic scars were enrolled into this study. Vancouver Scar Scale (VSS) was assessed by a plastic surgeon. LSCI was used to evaluate perfusion of the whole (W), marginal (M), central (C) regions, and surrounding normal skin of the scars, and ratios (M/N, C/N) were calculated. RESULTS: The perfusion of the marginal region in the keloid was significantly higher than that of the central region. Nevertheless, there was no significant difference in perfusion between the central and marginal regions in the early, proliferative, regressive, and mature hypertrophic scars. The degree of perfusion and perfusion ratio in the marginal region of keloid was similar to that of proliferative hypertrophic scars, and the degree of perfusion and perfusion ratio in central region of keloid group was similar to that of early and regressive hypertrophic scars. CONCLUSIONS: The difference in perfusion distribution in keloids and hypertrophic scars may provide ideas for their identification. LSCI may be a useful method for differentiating between keloids and hypertrophic scars.


Asunto(s)
Cicatriz Hipertrófica , Queloide , Cicatriz Hipertrófica/diagnóstico por imagen , Cicatriz Hipertrófica/patología , Humanos , Queloide/diagnóstico por imagen , Queloide/patología , Imágenes de Contraste de Punto Láser , Perfusión
8.
Nat Commun ; 5: 4531, 2014 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-25072163

RESUMEN

Inert octahedral chiral-at-metal complexes are an emerging class of asymmetric catalysts that exploit the globular, rigid nature and stereochemical options of octahedral compounds. While the central transition metal serves as a structural anchorpoint and provides metal centrochirality, catalysis is mediated through the organic ligand sphere, thereby merging the branches of transition metal catalysis and organocatalysis. Here we report the development of inert octahedral 3-aminopyrazolato iridium(III) complexes as novel chiral Brønsted base catalysts and demonstrate their merit with applications to highly effective asymmetric sulfa-Michael and aza-Henry reactions, permitting catalyst loadings down to 0.02 and 0.25 mol%, respectively. The observed high stereocontrol can be rationalized by a bifunctional mode of action in which the iridium catalyst, after the initial proton transfer, controls a ternary complex through defined hydrogen bonding interactions. This work reveals the potential of octahedral metal complexes as chiral scaffolds for the design of high-performance asymmetric catalysts.

9.
Tumour Biol ; 35(4): 3597-603, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24310503

RESUMEN

Many studies have examined the association between APE1 Asp148Glu (rs3136820) polymorphism gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. PubMed and CNKI databases were searched for case-control studies published up to October 2013. Data were extracted, and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 14 studies, comprising 4,165 lung cancer cases and 5,438 controls were included. Overall, for Glu carriers (Asp/Glu + Glu/Glu) versus wild-type homozygotes (Asp/Asp), the pooled OR was 1.05 (95% CI = 0.96-1.15 P = 0.000 for heterogeneity); for Glu/Glu versus Asp/Asp, the pooled OR was 1.07 (95% CI = 0.95-1.21 P = 0.007 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were not found among Asians or Caucasians. This updated meta-analysis suggests that the APE1 Asp148Glu polymorphisms are not associated with lung cancer risk among Asians or Caucasians.


Asunto(s)
ADN-(Sitio Apurínico o Apirimidínico) Liasa/genética , Predisposición Genética a la Enfermedad , Neoplasias Pulmonares/genética , Polimorfismo Genético , Humanos , Neoplasias Pulmonares/etiología , Sesgo de Publicación , Factores de Riesgo
10.
Dalton Trans ; 42(16): 5623-6, 2013 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-23503568

RESUMEN

(R)-4-(alkylthiomethyl)-5,5-dimethyl-2-(2'-hydroxyphenyl)-2-oxazolines are demonstrated to be highly suitable chiral auxiliaries for the two-step conversion of the half-sandwich complex [Ru(η(6)-C6H6)(bpy)Cl]Cl, bpy = 2,2'-bipyridine, into Δ-configured ruthenium polypyridyl complexes. The tailored thioether substituent at the oxazoline ring is essential for this conversion and not only promotes the removal of the benzene moiety but also controls the absolute metal-centered configuration. Applied to osmium, this strategy resulted in the first highly asymmetric synthesis of Δ-[Os(bpy)3](PF6)2.

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