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1.
Molecules ; 25(8)2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32316570

RESUMO

The ratio of substrate to catalyst (S/C) is a prime target for the application of asymmetric production of enantiomerically enriched intermediates by whole-cell biocatalyst. In the present study, an attractive increase in S/C was achieved in a natural deep-eutectic solvent (NADES) containing reaction system under microaerobic condition for high production of (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol ((S)-3,5-BTPE) with Candida tropicalis 104. In PBS buffer (0.2 M, pH 8.0) at 200 rpm and 30 °C, 79.5 g (Dry Cell Weight, DCW)/L C. tropicalis 104 maintained the same yield of 73.7% for the bioreduction of 3,5-bis(trifluoromethyl)acetophenone (BTAP) under an oxygen-deficient environment compared with oxygen-sufficient conditions, while substrate load increased 4.0-fold (from 50 mM to 200 mM). Furthermore, when choline chloride:trehalose (ChCl:T, 1:1 molar ratio) was introduced into the reaction system for its versatility of increasing cell membrane permeability and declining BTAP cytotoxicity to biocatalyst, the yields were further increased to 86.2% under 200 mM BTAP, or 72.9% at 300 mM BTAP. After the optimization of various reaction parameters involved in the bioreduction, and the amount of biocatalyst and maltose co-substrate remained 79.5 g (DCW)/L and 50 g/L, the S/C for the reduction elevated 6.3 times (3.8 mM/g versus 0.6 mM/g). By altering the respiratory pattern of the whole-cell biocatalyst and exploiting the ChCl:T-containing reaction system, the developed strategy exhibits an attractive potential for enhancing catalytic efficiency of whole-cell-mediated reduction, and provides valuable insight for the development of whole-cell catalysis.


Assuntos
Aerobiose , Fermentação , Álcool Feniletílico/metabolismo , Solventes , Anaerobiose , Candida tropicalis/metabolismo , Catálise , Estrutura Molecular , Oxigênio/metabolismo , Álcool Feniletílico/química , Solventes/química
2.
Front Psychiatry ; 15: 1427486, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39211541

RESUMO

Background: In the aftermath of bereavement, our research explores the subtleties of Prolonged Grief Disorder (PGD), focusing particularly on its correlation with suicidal behaviors and their variation across genders. This study seeks to elucidate the impact of gender on these behaviors among individuals suffering from PGD, thereby enhancing our understanding and facilitating the development of tailored therapeutic interventions. Methods: By November 24th, 2023, we had rigorously reviewed key databases such as PubMed, Web of Science, Cochrane Library, PsycINFO, and Embase. Independently, two researchers conducted detailed interviews and filled out questionnaires with participants to gather demographic information and record instances of prolonged grief disorder. The study also meticulously tracked occurrences of suicidal ideation, suicide attempts, suicide deaths, and self-injury among the participants. Results: The findings indicate that 22.34% of males reported suicidal ideation (95% CI: 21.33-23.35), a figure that rises to 26.84% among females (95% CI: 25.99-27.69). Notably, 12.11% of males attempted suicide (95% CI: 11.49-12.72), marginally surpassing the 9.60% observed in females (95% CI: 9.17-10.04). More striking disparities were observed in suicide deaths, with rates for males at 3.66% (95% CI: 3.32-4.00) compared to a notably higher 7.12% for females (95% CI: 6.44-7.81). Furthermore, the incidence of self-injury was lower among males, at 2.48% (95% CI: 2.03-2.94), than in females, who reported a rate of 5.09% (95% CI: 4.69-5.49). These patterns underscore the critical need for gender-specific interventions aimed at reducing these significant disparities. Conclusion: This study distinctly underscores the profound impact of gender on the manifestation of suicidal behaviors in individuals afflicted with prolonged grief disorder. It reveals that females are more prone to suicidal ideation, self-injury, and suicide deaths, while males predominantly exhibit a higher incidence of suicide attempts and risk-taking behaviors. These unmediated trends highlight the necessity for gender-specific clinical interventions tailored to address particular behaviors and modify prevalent patterns that typically resist conventional approaches. Systematic review registration: PROSPERO (york.ac.uk), identifier CRD42023480035.

3.
Nanoscale ; 9(37): 14215-14228, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-28914318

RESUMO

Piezoelectric composite (p-NC) made of a polymeric matrix and piezoelectric nanoparticles with conductive additives is an attractive material for many applications. As the matrix of p-NC is made of viscoelastic materials, both elastic and viscous characteristics of the matrix are expected to contribute to the piezoelectric response of p-NC. However, there is limited understanding of how viscoelasticity influences the piezoelectric performance of p-NC. Here we combined analytical and numerical analyses with experimental studies to investigate effects of viscoelasticity on piezoelectric performance of p-NC. The viscoelastic properties of synthesized p-NCs were controlled by changing the ratio between monomer and cross-linker of the polymer matrix. We found good agreement between our analytical models and experimental results for both quasi-static and dynamic loadings. It is found that, under quasi-static loading conditions, the piezoelectric coefficients (d33) of the specimen with the lowest Young's modulus (∼0.45 MPa at 5% strain) were ∼120 pC N-1, while the one with the highest Young's modulus (∼1.3 MPa at 5% strain) were ∼62 pC N-1. The results suggest that softer matrices enhance the energy harvesting performance because they can result in larger deformation for a given load. Moreover, from our theoretical analysis and experiments under dynamic loading conditions, we found the viscous modulus of a matrix is also important for piezoelectric performance. For instance, at 40 Hz and 50 Hz the storage moduli of the softest specimen were ∼0.625 MPa and ∼0.485 MPa, while the loss moduli were ∼0.108 MPa and ∼0.151 MPa, respectively. As piezocomposites with less viscous loss can transfer mechanical energy to piezoelectric particles more efficiently, the dynamic piezoelectric coefficient (d'33) measured at 40 Hz (∼53 pC N-1) was larger than that at 50 Hz (∼47 pC N-1) though it has a larger storage modulus. As an application of our findings, we fabricated 3D piezo-shells with different viscoelastic properties and compared the charging time. The results showed a good agreement with the predicted trend that the composition with the smallest elastic and viscous moduli showed the fastest charging rate. Our findings can open new opportunities for optimizing the performance of polymer-based multifunctional materials by harnessing viscoelasticity.

4.
Nat Commun ; 8(1): 589, 2017 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-28928431

RESUMO

Cachexia, characterized by muscle wasting, is a major contributor to cancer-related mortality. However, the key cachexins that mediate cancer-induced muscle wasting remain elusive. Here, we show that tumor-released extracellular Hsp70 and Hsp90 are responsible for tumor's capacity to induce muscle wasting. We detected high-level constitutive release of Hsp70 and Hsp90 associated with extracellular vesicles (EVs) from diverse cachexia-inducing tumor cells, resulting in elevated serum levels in mice. Neutralizing extracellular Hsp70/90 or silencing Hsp70/90 expression in tumor cells abrogates tumor-induced muscle catabolism and wasting in cultured myotubes and in mice. Conversely, administration of recombinant Hsp70 and Hsp90 recapitulates the catabolic effects of tumor. In addition, tumor-released Hsp70/90-expressing EVs are necessary and sufficient for tumor-induced muscle wasting. Further, Hsp70 and Hsp90 induce muscle catabolism by activating TLR4, and are responsible for elevation of circulating cytokines. These findings identify tumor-released circulating Hsp70 and Hsp90 as key cachexins causing muscle wasting in mice.Cachexia affects many cancer patients causing weight loss and increasing mortality. Here, the authors identify extracellular Hsp70 and Hsp90, either in soluble form or secreted as part of exosomes from tumor cells, to be responsible for tumor induction of cachexia.


Assuntos
Caquexia/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Músculo Esquelético/metabolismo , Neoplasias/complicações , Receptor 4 Toll-Like/metabolismo , Animais , Caquexia/etiologia , Caquexia/genética , Linhagem Celular Tumoral , Vesículas Extracelulares/genética , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP90/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mioblastos/metabolismo , Receptor 4 Toll-Like/genética
5.
Autophagy ; 10(9): 1522-34, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24988326

RESUMO

AMP-activated protein kinase α1 knockout (prkaa1(-/-)) mice manifest splenomegaly and anemia. The underlying molecular mechanisms, however, remain to be established. In this study, we tested the hypothesis that defective autophagy-dependent mitochondrial clearance in prkaa1(-/-) mice exacerbates oxidative stress, thereby enhancing erythrocyte destruction. The levels of ULK1 phosphorylation, autophagical flux, mitochondrial contents, and reactive oxygen species (ROS) were examined in human erythroleukemia cell line, K562 cells, as well as prkaa1(-/-) mouse embryonic fibroblasts and erythrocytes. Deletion of Prkaa1 resulted in the inhibition of ULK1 phosphorylation at Ser555, prevented the formation of ULK1 and BECN1- PtdIns3K complexes, and reduced autophagy capacity. The suppression of autophagy was associated with enhanced damaged mitochondrial accumulation and ROS production. Compared with wild-type (WT) mice, prkaa1(-/-) mice exhibited a shortened erythrocyte life span, hemolytic destruction of erythrocytes, splenomegaly, and anemia, all of which were alleviated by the administration of either rapamycin to activate autophagy or Mito-tempol, a mitochondria-targeted antioxidant, to scavenge mitochondrial ROS. Furthermore, transplantation of WT bone marrow into prkaa1(-/-) mice restored mitochondrial removal, reduced intracellular ROS levels, and normalized hematologic parameters and spleen size. Conversely, transplantation of prkaa1 (-/-) bone marrow into WT mice recapitulated the prkaa1(-/-) mouse phenotypes. We conclude that PRKAA1-dependent autophagy-mediated clearance of damaged mitochondria is required for erythrocyte maturation and homeostasis.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/genética , Eritrócitos/citologia , Eritrócitos/metabolismo , Mitocôndrias/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Antioxidantes/farmacologia , Autofagia/efeitos dos fármacos , Linhagem Celular , Humanos , Camundongos , Camundongos Knockout , Mitocôndrias/genética , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
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