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1.
Nature ; 627(8005): 754-758, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38093004

RESUMEN

Shock-breakout emission is light that arises when a shockwave, generated by the core-collapse explosion of a massive star, passes through its outer envelope. Hitherto, the earliest detection of such a signal was at several hours after the explosion1, although a few others had been reported2-7. The temporal evolution of early light curves should provide insights into the shock propagation, including explosion asymmetry and environment in the vicinity, but this has been hampered by the lack of multiwavelength observations. Here we report the instant multiband observations of a type II supernova (SN 2023ixf) in the galaxy M101 (at a distance of 6.85 ± 0.15 Mpc; ref. 8), beginning at about 1.4 h after the explosion. The exploding star was a red supergiant with a radius of about 440 solar radii. The light curves evolved rapidly, on timescales of 1-2 h, and appeared unusually fainter and redder than predicted by the models9-11 within the first few hours, which we attribute to an optically thick dust shell before it was disrupted by the shockwave. We infer that the breakout and perhaps the distribution of the surrounding dust were not spherically symmetric.

2.
Plant J ; 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-39387436

RESUMEN

Radish (Raphanus sativus L.) is one of the most important root vegetable crops worldwide. However, gene function exploration and germplasm innovation still face tremendous challenges due to its extremely low transformation efficiency. Here, an economic and highly efficient genetic transformation method for radish was explored by Agrobacterium rhizogenes-mediated transformation with the help of combining special developmental regulator (DR) genes and the visual identification reporter. Firstly, the RUBY gene, a betalain biosynthesis system, could result in a visual red-violet color used as a convenient and effective reporter for monitoring transgenic hairy roots screening of radish. However, the hairy roots-to-shoots conversion system of radish still stands as a barrier to the obtainment of whole transgenic plants, although different hormone combinations and various culture conditions were tried. Following, two DR genes including Wuschel2 (Wus2) and isopentenyl transferase (ipt), as well as their combination Wus2-ipt were introduced for the shoot regeneration capacity improvement. The results showed that the transgenic shoots could be directly generated without externally supplying any hormones in the presence of a Wus2-ipt combination. Then, Wus2-ipt along with the RUBY reporter was employed to establish an efficient genetic transformation system of radish. Moreover, this system was applied in generating gene-edited radish plants and the phytoene desaturase (RsPDS) gene was effectively knockout through albino phenotype observation and sequencing analysis. These findings have the potential to be widely applied in genetic transformation and genome-editing genetic improvement of other vegetable species.

3.
RNA ; 29(6): 777-789, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36810234

RESUMEN

N6-methyladenosine (m6A) in mRNA regulates almost every stage in the mRNA life cycle, and the development of methodologies for the high-throughput detection of methylated sites in mRNA using m6A-specific methylated RNA immunoprecipitation with next-generation sequencing (MeRIPSeq) or m6A individual-nucleotide-resolution cross-linking and immunoprecipitation (miCLIP) have revolutionized the m6A research field. Both of these methods are based on immunoprecipitation of fragmented mRNA. However, it is well documented that antibodies often have nonspecific activities, thus verification of identified m6A sites using an antibody-independent method would be highly desirable. We mapped and quantified the m6A site in the chicken ß-actin zipcode based on the data from chicken embryo MeRIPSeq results and our RNA-Epimodification Detection and Base-Recognition (RedBaron) antibody-independent assay. We also demonstrated that methylation of this site in the ß-actin zipcode enhances ZBP1 binding in vitro, while methylation of a nearby adenosine abolishes binding. This suggests that m6A may play a role in regulating localized translation of ß-actin mRNA, and the ability of m6A to enhance or inhibit a reader protein's RNA binding highlights the importance of m6A detection at nucleotide resolution.


Asunto(s)
Actinas , Pollos , Animales , Embrión de Pollo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Actinas/genética , Pollos/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , ARN/metabolismo , Anticuerpos , Nucleótidos/metabolismo
4.
Mol Psychiatry ; 2024 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-39394455

RESUMEN

Antidepressants are among the most extensively prescribed psychotropic drugs worldwide. Discontinuation induced withdrawal symptoms have been reported for almost all antidepressants. The incidence of antidepressant withdrawal syndrome (AWS) and other characteristics remain unknown. We searched the PubMed, Embase, PsycINFO, MEDLINE, CINAHL, and Cochrane Central Register of Controlled Trials databases from inception to December 31, 2023. Randomized double-blinded trials, longitudinal or cross-sectional studies that reported the incidence and other characteristics of antidepressant withdrawal symptoms were included. The pooled incidence of AWS was calculated by a random effects model. We included 35 studies, of which 2 studies just provided incidence of specific withdrawal symptoms, and 4 studies only described other characteristics. The pooled incidence of AWS from all available studies was 42.9%, from 11 RCTs was 44.4%, in studies in which the treatment duration was mostly 8-12 weeks, which usually appear within 2 weeks, and were generally measured for <4 weeks. The incidence in selective serotonin-norepinephrine reuptake inhibitors was the lowest (29.7%), followed by selective serotonin reuptake inhibitors (45.6%) and tricyclic antidepressants (59.7%), without significant differences (p = 0.221). Treatment duration showed a dose-response to the incidence of AWS (6-12 W: 35.1%, 12-24 W: 42.7%, >24 W: 51.4%). The half-life did not show such a simple dose-dependent relationship. The pooled estimate was robust regardless whether withdrawal symptoms were measured in RCTs or observational studies (including face-to-face and online survey studies). Tapering the dose reduced the incidence of AWS compared with abrupt stoppage (34.5% vs 42.5%), without a significant difference (p = 0.484). Risk factors for withdrawal symptoms included being female, younger, experiencing adverse effects early in treatment, taking higher doses or longer duration of medication, abrupt cessation of drugs, and those with a lower clearance of drugs or with serotonin 1A receptor gene variation. The findings suggest the incidence of AWS are common and some clinical characteristics and risk factors which can help clinicians identify who is at greater risk of experiencing AWS. Discontinuation studies on long-term antidepressant users with long follow-up periods are required in the future.

5.
J Am Chem Soc ; 146(5): 3396-3404, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38266485

RESUMEN

Covalent organic frameworks (COFs), with the features of flexible structure regulation and easy introduction of functional groups, have aroused broad interest in the field of photocatalysis. However, due to the low light absorption intensity, low photoelectron conversion efficiency, and lack of suitable active sites, it remains a great challenge to achieve efficient photocatalytic aerobic oxidation reactions. Herein, based on reticular chemistry, we rationally designed a series of three-motif molecular junction type COFs, which formed dual photosensitizer coupled redox molecular junctions containing multifunctional COF photocatalysts. Significantly, due to the strong light adsorption ability of dual photosensitizer units and integrated oxidation and reduction features, the PY-BT COF exhibited the highest activity for photocatalytic aerobic oxidation. Especially, it achieved a photocatalytic benzylamine conversion efficiency of 99.9% in 2.5 h, which is much higher than that of the two-motif molecular junctions with only one photosensitizer or redox unit lacking COFs. The mechanism of selective aerobic oxidation was studied through comprehensive experiments and density functional theory calculations. The results showed that the photoinduced electron transfer occurred from PY and then through triphenylamine to BT. Furthermore, the thermodynamics energy for benzylamine oxidation on PY-BT COF was much lower than that for others, which confirmed the synergistic effect of dual photosensitizer coupled redox molecular junction COFs. This work provided a new strategy for the design of functional COFs with three-motif molecular junctions and also represented a new insight into the multifunctional COFs for organic catalytic reactions.

6.
J Am Chem Soc ; 146(37): 25832-25840, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39231362

RESUMEN

The connectivity (valency) of building blocks for constructing 3D covalent organic frameworks (COFs) has long been limited to 4, 6, 8, and 12. Developing a higher connectivity remains a great challenge in the field of COF structural design. Herein, this work reports a hierarchical expansion strategy for making 16-connected building blocks to construct 3D COFs with sqc topology. The [16 + 2] construction achieved by condensation between a 16-connected carbazolyl dicyanobenzene-based building block (CzTPN) and linear diamino linkers (BD or Bpy) affords two 3D COFs (named CzBD COF and CzBpy COF). Furthermore, attributed to the well-organized donor-acceptor (D-A) heterojunction, the Ni chelated CzBpy COF (Ni@CzBpy COF) exhibits excellent performance for photoredox/Ni dual catalytic C(sp3)-C(sp2) cross-coupling of alkyltrifluoroborates with aryl halides, achieving a maximum 98% conversion and 94% yield for various substrates. This work developed the first case of high-connectivity COFs bearing 16-connected units, which is the highest connectivity reported until now, and achieved efficient photocatalysis applications, thus greatly enriching the possibilities of COFs.

7.
Oncologist ; 29(7): e941-e948, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38557816

RESUMEN

OBJECTIVE: Unsafe opioid-related practices can lead to abuse, diversion, and accidental overdoses. In this study, we aimed to describe the patterns and beliefs regarding the storage, disposal, and use of opioids among Chinese patients with cancer in their home settings, which remain unclear. METHODS: A multicenter cross-sectional survey was conducted in Hubei Province from October 2022 to June 2023. We collected information on the storage, disposal, and use of opioids among cancer pain inpatients in the oncology department. Logistic regression was used to estimate the factors associated with unsafe disposal and use of opioids. RESULTS: The survey included 221 patients with a median age of 62 years. Only 3.2% stored their opioids under lock and key, and 49.8% were unaware of proper disposal methods. Nearly one-fifth (19.5%) reported having received information on the safe storage (14.0%) and/or disposal (10.0%) of opioids. A total of 44.3% reported unsafe use by sharing (1.8%), losing (4.1%), or taking opioids at a higher dose than prescribed (42.5%). Patients who did not receive information on the safe disposal of opioids (OR = 4.57, P = .0423), had a history of alcohol use (OR = 1.91, P = .0399), and used opioids other than morphine (OR = 2.31, P = .0461) had higher odds of unsafe disposal practices. Individuals with an associate degree/bachelor's degree or above were less likely to dispose of (OR = 0.36, P = .0261) and use (OR = 0.31, P = .0127) opioids unsafely. CONCLUSION: A significant proportion of Chinese patients with cancer exhibit unsafe practices in the storage, disposal, and use of opioids. The study highlights an urgent need for implementing routine education programs and drug "take-back" initiatives to improve opioid-related practices.


Asunto(s)
Analgésicos Opioides , Neoplasias , Humanos , Estudios Transversales , Masculino , Analgésicos Opioides/efectos adversos , Analgésicos Opioides/uso terapéutico , Femenino , Persona de Mediana Edad , China/epidemiología , Anciano , Neoplasias/epidemiología , Neoplasias/tratamiento farmacológico , Dolor en Cáncer/tratamiento farmacológico , Adulto , Almacenaje de Medicamentos/normas , Almacenaje de Medicamentos/métodos , Encuestas y Cuestionarios
8.
Anal Chem ; 96(29): 11845-11852, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38976499

RESUMEN

Integration of optical components into microfluidic devices can enhance particle manipulations, separations, and analyses. We present a method to fabricate microscale diffractive lenses composed of aperiodically spaced concentric rings milled into a thin metal film to precisely position optical tweezers within microfluidic channels. Integrated thin-film microlenses perform the laser focusing required to generate sufficient optical forces to trap particles without significant off-device beam manipulation. Moreover, the ability to trap particles with unfocused laser light allows multiple optical traps to be powered simultaneously by a single input laser. We have optically trapped polystyrene particles with diameters of 0.5, 1, 2, and 4 µm over microlenses fabricated in chromium and gold films. Optical forces generated by these microlenses captured particles traveling at fluid velocities up to 64 µm/s. Quantitative trapping experiments with particles in microfluidic flow demonstrate size-based differential trapping of neutrally buoyant particles where larger particles required a stronger trapping force. The optical forces on these particles are identical to traditional optical traps, but the addition of a continuous viscous drag force from the microfluidic flow introduces tunable size selectivity across a range of laser powers and fluid velocities.

9.
Small ; 20(23): e2309134, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38150666

RESUMEN

Almost all colloidal quantum dots (QDs) exhibit undesired photoluminescence (PL) blinking, which poses a significant obstacle to their use in numerous luminescence applications. An in-depth study of the blinking behavior, along with the associated mechanisms, can provide critical opportunities for fabricating high-quality QDs for diverse applications. Here the blinking of a large series of colloidal QDs is investigated with different surface ligands, particle sizes, shell thicknesses, and compositions. It is found that the blinking behavior of single alloyed CdSe/ZnS QDs with a shell thickness of up to 2 nm undergoes an irreversible conversion from Auger-blinking to band-edge carrier blinking (BC-blinking). Contrastingly, single perovskite QDs with particle sizes smaller than their Bohr diameters exhibit reversible conversion between BC-blinking and more pronounced Auger-blinking. Changes in the effective trapping sites under different excitation conditions are found to be responsible for the blinking type conversions. Additionally, changes in shell thickness and particle size of QDs have a significant effect on the blinking type conversions due to altered wavefunction overlap between excitons and effective trapping sites. This study elucidates the discrepancies in the blinking behavior of various QD samples observed in previous reports and provides deeper understanding of the mechanisms underlying diverse types of blinking.

10.
HIV Med ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39221521

RESUMEN

OBJECTIVE: Our objective was to evaluate the trajectory of immunology in patients with HIV with different baseline CD4 T-cell count strata after antiretroviral therapy (ART) under long-term viral suppression. METHODS: This was a sub-analysis focused on patients with virological suppression for at least 5 years after ART. Data were obtained from the Yunnan HIV cohort in China. Patients were categorized according to prespecified baseline CD4 T-cell counts. The trajectories of CD4 T-cell count, CD8 T-cell count, and CD4/CD8 ratio changing over time were fitted using a B-spline regression model. The Cox proportional hazards regression model was used to assess the association of baseline CD4 T-cell count with the risk of both immunological responder (IR) and CD4/CD8 ratio normalization. RESULTS: A total of 2618 patients with a median follow-up of 7.25 years (interquartile range [IQR] 5.92-8.75) were included. Over a period of 12 years, the mean CD4 T-cell count remained above 500 cells/µL in all groups. The mean CD4/CD8 ratio was solely normalized in patients whose baseline CD4 T-cell counts were above 350 cells/µL. Patients with higher baseline CD4 T-cell counts showed higher risks of both IR and CD4/CD8 ratio normalization than those with the lowest (all p trend <0.001). A higher baseline CD4 T-cell count predicted a shorter time for both IR and CD4/CD8 ratio normalization. CONCLUSIONS: Long-term, sustained viral suppression may not be able to fully normalize immunological functions in patients with HIV. A high baseline CD4 T-cell count benefits IR and CD4/CD8 ratio normalization.

11.
Exp Dermatol ; 33(1): e15011, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38284208

RESUMEN

Psoriasis is an immune-mediated inflammatory disease commonly accompanied by various metabolic disorders. It is widely known that biologics could affect the metabolic status and comorbidities in psoriasis patients, however, the effects of biologics on metabolism in psoriasis patients remain poorly understood. The aim of this study was to elucidate the characteristic changes of metabolic profiling in psoriasis vulgaris (PsV) patients before and after applying biologics. Plasma samples were collected from a retrospective cohort of 43 PsV patients. Non-targeted metabolomics analyses were performed using liquid chromatography-mass spectrometry (LC-MS) to compare the metabolic profiles before and after applying adalimumab (ADA) or ixekizumab (IXE) for 4 weeks. Additionally, correlation analyses were conducted to investigate the associations between metabolite expression levels and clinical characteristics. The biologics significantly affected the metabolic profiles of PsV patients especially in glycerophospholipids (GPs). First, phosphatidylcholine (PC), unsaturated lysophosphatidylcholine (LPC), unsaturated lysophosphatidic acid (LPA) and unsaturated lysophosphatidylethanolamine (LPE) were significantly up-regulated, whereas phosphatidylethanolamine (PE), saturated LPC, saturated LPA and saturated LPE were predominantly down-regulated after biologic treatment. What is more, the changes in PE and LPA were mainly observed after applying IXE instead of ADA. Second, we also found GPs including PC, unsaturated LPC, unsaturated LPA and unsaturated LPE were primarily negatively correlated with disease severity, whereas, PE, saturated LPC, saturated LPA and saturated LPE displayed inverse correlations. Biologics could affect GP metabolism and facilitate the transition of metabolic status from a pro-inflammatory to an anti-inflammatory phenotype in PsV patients.


Asunto(s)
Productos Biológicos , Psoriasis , Humanos , Estudios Retrospectivos , Psoriasis/tratamiento farmacológico , Adalimumab/uso terapéutico , Fosfatidilcolinas , Productos Biológicos/uso terapéutico
12.
Exp Eye Res ; 244: 109936, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38763351

RESUMEN

Non-infectious uveitis is an intraocular autoimmune disease mainly characterized by immune dysregulation of the eye, which may cause blindness if not well treated. Interleukin 10 (IL-10) is a potent cytokine with multiple immunoregulatory functions. However, it's in vivo activity is unstable owing to its inherent protein instability and short plasma half-life. Therefore, our previous research tried to establish IL-10-overexpressing MSC-sEVs (sEVs-IL10) using lentiviral transfection. While this approach indeed improved drug delivery, it also suffered from tedious procedures and limited loading efficiency. Accordingly, we constructed a novel MSC-sEVs-based delivery system for IL-10 (IL-10@sEVs) by sonication. The obtained formulation (IL-10@sEVs) had relatively higher loading efficiency and exerted a more profound immunomodulatory effect than sEVs-IL10 in vitro. Furthermore, IL-10@sEVs had significant therapeutic effects in a mouse model of experimental autoimmune uveitis (EAU) by decreasing the percentage of Th17 cells, increasing regulatory T cells in the eye, and draining lymph nodes. In summary, sonication outperforms conventional transfection methods for loading IL-10 into MSC-sEVs.


Asunto(s)
Enfermedades Autoinmunes , Vesículas Extracelulares , Interleucina-10 , Uveítis , Animales , Femenino , Ratones , Enfermedades Autoinmunes/tratamiento farmacológico , Modelos Animales de Enfermedad , Sistemas de Liberación de Medicamentos , Interleucina-10/genética , Ratones Endogámicos C57BL , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Transfección , Uveítis/tratamiento farmacológico
13.
J Rheumatol ; 51(7): 678-681, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38490673

RESUMEN

OBJECTIVE: To determine the minimal important change (MIC) and meaningful change value (MCV) of the Disease Activity Index for Psoriatic Arthritis (DAPSA) and the effect size (ES) of DAPSA. METHODS: This was a retrospective cohort study, recruiting 106 patients who agreed to participate in the research from the Department of Dermatology, Xiangya Hospital, between November 1, 2019, and April 1, 2023. An anchor-based method using linear regression analyses was used to determine the MICs and MCVs of the DAPSA. The anchor question assessed whether the patient's well-being had changed since their previous visit, employing a 5-point Likert scale that ranged from "much improved" to "much deteriorated." RESULTS: The overall MIC value was 8.4 (95% CI 0.01-16.75). The MIC improvement was 9.5 (95% CI 0.89-18.14) and MIC deterioration was 1.1 (95% CI -9.81 to 12.05). The overall MCV was 10.5 (95% CI 4.34-16.72). MCV improvement was 11.4 (95% CI 5.95-16.95) and MCV deterioration was 1.1 (95% CI -9.81 to 12.05). The ES was 0.6. CONCLUSION: A change in DAPSA of 8.4 is indicative of an MIC, offering physicians an additional means to contextualize the patient's perception of disease activity during treatment, and a change in DAPSA of 10.5 is likely to be regarded as MCV. These values can enhance the utility of DAPSA in psoriatic arthritis clinical trials.


Asunto(s)
Artritis Psoriásica , Índice de Severidad de la Enfermedad , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Artritis Psoriásica/diagnóstico , China , Pueblos del Este de Asia , Estudios Longitudinales , Diferencia Mínima Clínicamente Importante , Estudios Retrospectivos
14.
Eur J Neurol ; : e16431, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39104135

RESUMEN

BACKGROUND AND PURPOSE: Considering the reliance of serum uric acid (SUA) levels on renal clearance function, its role in stroke outcomes remains controversial. This study investigated the association of renal function-normalized SUA (SUA to serum creatinine ratio, SUA/SCr), a novel renal function index, with the 1-year outcomes in patients with acute ischemic stroke (AIS). METHODS: This is a prospective, multicenter observational study. Renal function-normalized SUA levels were determined by calculating the ratio of SUA to SCr. One-year outcomes included stroke recurrence, all-cause mortality, and poor prognosis. Multivariable Cox regression analyses and restriction cubic splines for curve fitting were used to evaluate SUA/SCr's association with 1-year stroke outcomes. RESULTS: Among 2294 enrolled patients, after adjustment for potential confounders, multivariable Cox regression analyses showed that each one-unit increase in SUA/SCr corresponded to a 19% decrease in 1-year stroke recurrence in patients with AIS. SUA/SCr was analyzed as a continuous variable and categorized into quartiles (Q1-Q4). Compared with the Q1 reference group, Q2, Q3, and Q4 showed significantly lower 1-year stroke recurrence risks. The trend test indicated significant differences in the 1-year stroke recurrence trend from Q1 to Q4. In these patients, SUA/SCr did not show a significant association with poor prognosis or all-cause mortality. Curve fitting revealed SUA/SCr had a negative but nonlinear association with 1-year stroke recurrence. CONCLUSIONS: In patients with AIS, low SUA/SCr may be an independent risk factor for 1-year stroke recurrence. Changes in SUA/SCr had no significant impact on 1-year poor prognosis and all-cause mortality.

15.
Mol Breed ; 44(10): 64, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39301413

RESUMEN

Cotton is a widely planted commercial crop in the world. Enhancing fiber yield and quality is a long-term goal for cotton breeders. Our previous work has demonstrated that fine promotion of auxin biosynthesis in ovule epidermis, by overexpressing FBP7pro::iaaM, has a significant improvement on lint yield and fiber fineness. Lately, transgenic cottons overexpressing GhROP6 variants modify mature fiber length by controlling GhPIN3a-mediated polar auxin transport in ovules. Here, this study showed that all these GhROP6-related cottons displayed unsatisfactory agronomic performance in field conditions. Yet extra auxin supply could promote their fiber development, suggesting inadequate auxin supply in the ovules. Thus, these cottons were integrated with enhanced auxin synthesis by crossing with FBP7pro::iaaM cotton. All the transgene-stacked cottons exhibited synergetic effects on cotton yield (seedcotton yield, lint yield, and lint percentage) and quality (length, strength, and micronaire). Notably, comparing to the FBP7pro::iaaM background, the transgene-stacked cotton co-expressing FBP7pro::iaaM and CA-ghrop6 (constitutively active GhROP6) exhibited a 12.6% increase in seedcotton yield and a 19.0% increase in lint yield over a three-year field trial, and simultaneously resulted in further improvement on fiber length, strength, and micronaire. Collectively, our data provide a potential strategy for genetic improvement on cotton fiber yield and quality. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01500-w.

16.
J Phys Chem A ; 128(8): 1511-1522, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38362878

RESUMEN

Tetrafluoropropyne (C3F4) is a potential dielectric in various electrical insulating equipment to replace the most potent industrial greenhouse gas, sulfur hexafluoride. Atmospheric oxidation of C3F4 by OH radicals in the presence of molecular O2 has been investigated theoretically in order to clarify the lifetime and degradation products at mechanistic and kinetic aspects. Energetic minimum-energy pathways for the C3F4 + OH/O2 reactions were calculated in detail using various theoretical methods including density functional M06-2X and CCSD for geometries, CBS-QB3, CCSD(T), and multireference RS2 with extrapolation to the complete basis-set limit for energies. It has been demonstrated that the C3F4 + OH reaction takes place via the bifurcated C-O addition/elimination routes leading to CF3C(OH)═CF and CF3C═C(OH)F radical adducts, where the latter is more preferable in view of the difference in barrier heights (1.3 vs 0.3 kcal/mol), followed by H-migration, HF-elimination, and C-C and C-F bond fission. The atmospheric lifetime of C3F4 was estimated to be about 13 days, which is indicative of a very short-lived substance in the atmosphere. Further degradation of the energy-rich C3F4OH* intermediates by O2 takes place spontaneously in view of the successive barrier-free and highly exothermic pathways, producing a variety of fluorinated acids, anhydrides, biacetyls, and regenerating OH radicals. For comparison, the reactions of C3H4, CF3CCH, and CH3CCF with OH radicals were examined to clarify the F-substitution effect. It is revealed that the reactivity of fluoropropynes could be either reduced by CF3 or enhanced by atomic F attached to the acetylenic carbon. The present work provides a fundamental understanding of the reactions of fluoroalkynes with OH/O2. The use of C3F4 as a promising eco-friendly gaseous dielectric alternative to SF6 has been supported.

17.
Acta Pharmacol Sin ; 45(7): 1520-1529, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38519646

RESUMEN

Parkin (PARK2) deficiency is frequently observed in various cancers and potentially promotes tumor progression. Here, we showed that Parkin expression is downregulated in liver cancer tissues, which correlates with poor patient survival. Parkin deficiency in liver cancer cells promotes migration and metastasis as well as changes in EMT and metastasis markers. A negative correlation exists between TMEFF1 and Parkin expression in liver cancer cells and tumor tissues. Parkin deficiency leads to upregulation of TMEFF1 which promotes migration and metastasis. TMEFF1 transcription is activated by Parkin-induced endogenous TGF-ß production and subsequent phosphorylation of Smad2/3 and its binding to TMEFF1 promotor. TGF-ß inhibitor and TMEFF1 knockdown can reverse shParkin-induced cell migration and changes of EMT markers. Parkin interacts with and promotes the ubiquitin-dependent degradation of HIF-1α/HIF-1ß and p53, which accounts for the suppression of TGF-ß production. Our data have revealed that Parkin deficiency in cancer leads to the activation of the TGF-ß/Smad2/3 pathway, resulting in the expression of TMEFF1 which promotes cell migration, EMT, and metastasis in liver cancer cells.


Asunto(s)
Movimiento Celular , Neoplasias Hepáticas , Proteína Smad2 , Proteína smad3 , Factor de Crecimiento Transformador beta , Ubiquitina-Proteína Ligasas , Humanos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Línea Celular Tumoral , Transducción de Señal , Activación Transcripcional , Animales , Transición Epitelial-Mesenquimal , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Metástasis de la Neoplasia , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/genética , Ratones Desnudos , Ratones
18.
Environ Res ; 245: 117959, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38123047

RESUMEN

Lake eutrophication mitigation measures have been implemented by ecological water diversion, however, the responses of carbon cycle to the human-derived hydrologic process still remains unclear. With a famous river-to-lake water diversion activity at eutrophic Lake Taihu, we attempted to fill the knowledge gap with integrative field measurements (2011-2017) of gas carbon (CO2 and CH4) flux, including CO2-equivalent, and dissolved carbon (DOC and DIC) at water-receiving zone and reference zone. Overall, results showed the artificial water diversion activity increased gas carbon emissions. At water-receiving zone, total gas carbon (expressed as CO2-equivalent) emissions increased significantly due to the occurring of water diversion, with CO2 flux increasing from 9.31 ± 16.28 to 18.16 ± 12.96 mmol C m-2 d-1. Meanwhile, CH4 emissions at water-receiving zone (0.06 ± 0.05 mmol C m-2 d-1) was double of that at reference zone. Water diversion decreased DOC but increased DIC especially at inflowing river mouth. Temporal variability of carbon emissions and dissolved carbon were linked to water temperature, chlorophyll a, and nutrient, but less or negligible dependency on these environment variables were found with diversion occurring. Water diversion may increase gas carbon production via stimulating DOC mineralization with nutrient enrichment, which potentially contribute to increasing carbon emissions and decreasing DOC at the same time and the significant correlation between CO2 flux and CH4 flux. Our study provided new insights into carbon biogeochemical processes, which may help to predict carbon fate under hydrologic changes of lakes.


Asunto(s)
Lagos , Agua , Humanos , Carbono , Dióxido de Carbono/análisis , Clorofila A , China , Metano/análisis
19.
J Chem Phys ; 160(17)2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38748025

RESUMEN

Determining the correlation between the size of a single quantum dot (QD) and its photoluminescence (PL) properties is a challenging task. In the study, we determine the size of each QD by measuring its absorption cross section, which allows for accurate investigation of size-dependent PL blinking mechanisms and volume scaling of the biexciton Auger recombination at the single-particle level. A significant correlation between the blinking mechanism and QD size is observed under low excitation conditions. When the QD size is smaller than their Bohr diameter, single CsPbI3 perovskite QDs tend to exhibit BC-blinking, whereas they tend to exhibit Auger-blinking when the QD size exceeds their Bohr diameter. In addition, by extracting bright-state photons from the PL intensity trajectories, the effects of QD charging and surface defects on the biexcitons are effectively reduced. This allows for a more accurate measurement of the volume scaling of biexciton Auger recombination in weakly confined CsPbI3 perovskite QDs at the single-dot level, revealing a superlinear volume scaling (τXX,Auger ∝ σ1.96).

20.
BMC Geriatr ; 24(1): 284, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38532326

RESUMEN

BACKGROUND: Dyadic coping resources have been considered a potential explanatory mechanism of spousal interdependence in health, but the mediation of spousal collaboration for the relationship between self-rated health and depressive symptoms has yet to be examined. This study aimed to investigate the within- (actor effect) and between-partner effects of self-rated health on depressive symptoms in community-dwelling older couples facing physical functioning limitations and to examine the role of spousal collaboration in mediating the actor and cross-partner effects of self-rated health on depressive symptoms. METHOD: Data from 185 community-dwelling older Chinese married couples were analyzed using the actor-partner interdependence mediation model (APIMeM). Couples were interviewed through trained research assistants using the 5-item common dyadic coping subscale of the Dyadic Coping Inventory (DCI), the Visual Analog Scale (VAS) of the QoL questionnaire EQ-5D and the Patient Health Questionnaire-9 (PHQ-9). RESULTS: Husbands' self-rated health had an actor effect on their own depressive symptoms and a partner effect on their wives' depressive symptoms. Wives' self-rated health had an actor effect on their own depressive symptoms. The actor effects between self-rated health and depressive symptoms were partially mediated by their own perception of spousal collaboration. Furthermore, husbands' self-rated health not only affects wives' depressive symptoms directly but also indirectly by influencing wives' perceptions of spousal collaboration. DISCUSSION: The findings from this study underscored the importance of viewing couples' coping processes from a dyadic and gender-specific perspective, since more (perceived) collaborative efforts have beneficial effects on both partners' mental health outcomes.


Asunto(s)
Depresión , Calidad de Vida , Humanos , Depresión/psicología , Esposos/psicología , Encuestas y Cuestionarios , China
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