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1.
Cell ; 186(18): 3845-3861.e24, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37591240

RESUMO

Dopaminergic projections regulate various brain functions and are implicated in many neuropsychiatric disorders. There are two anatomically and functionally distinct dopaminergic projections connecting the midbrain to striatum: nigrostriatal, which controls movement, and mesolimbic, which regulates motivation. However, how these discrete dopaminergic synaptic connections are established is unknown. Through an unbiased search, we identify that two groups of antagonistic TGF-ß family members, bone morphogenetic protein (BMP)6/BMP2 and transforming growth factor (TGF)-ß2, regulate dopaminergic synapse development of nigrostriatal and mesolimbic neurons, respectively. Projection-preferential expression of their receptors contributes to specific synapse development. Downstream, Smad1 and Smad2 are specifically activated and required for dopaminergic synapse development and function in nigrostriatal vs. mesolimbic projections. Remarkably, Smad1 mutant mice show motor defects, whereas Smad2 mutant mice show lack of motivation. These results uncover the molecular logic underlying the proper establishment of functionally segregated dopaminergic synapses and may provide strategies to treat relevant, projection-specific disease symptoms by targeting specific BMPs/TGF-ß and/or Smads.


Assuntos
Corpo Estriado , Dopamina , Animais , Camundongos , Mesencéfalo , Motivação , Movimento , Sinapses
2.
EMBO J ; 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39322757

RESUMO

Enzymatic parameters are classically determined in vitro, under conditions that are far from those encountered in cells, casting doubt on their physiological relevance. We developed a generic approach combining tools from synthetic and systems biology to measure enzymatic parameters in vivo. In the context of a synthetic carotenoid pathway in Saccharomyces cerevisiae, we focused on a phytoene synthase and three phytoene desaturases, which are difficult to study in vitro. We designed, built, and analyzed a collection of yeast strains mimicking substantial variations in substrate concentration by strategically manipulating the expression of geranyl-geranyl pyrophosphate (GGPP) synthase. We successfully determined in vivo Michaelis-Menten parameters (KM, Vmax, and kcat) for GGPP-converting phytoene synthase from absolute metabolomics, fluxomics and proteomics data, highlighting differences between in vivo and in vitro parameters. Leveraging the versatility of the same set of strains, we then extracted enzymatic parameters for two of the three phytoene desaturases. Our approach demonstrates the feasibility of assessing enzymatic parameters directly in vivo, providing a novel perspective on the kinetic characteristics of enzymes in real cellular conditions.

3.
EMBO J ; 43(9): 1843-1869, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38565948

RESUMO

The RNA-silencing effector ARGONAUTE10 influences cell fate in plant shoot and floral meristems. ARGONAUTE10 also accumulates in the root apical meristem (RAM), yet its function(s) therein remain elusive. Here, we show that ARGONAUTE10 is expressed in the root cell initials where it controls overall RAM activity and length. ARGONAUTE10 is also expressed in the stele, where post-transcriptional regulation confines it to the root tip's pro-vascular region. There, variations in ARGONAUTE10 levels modulate metaxylem-vs-protoxylem specification. Both ARGONAUTE10 functions entail its selective, high-affinity binding to mobile miR165/166 transcribed in the neighboring endodermis. ARGONAUTE10-bound miR165/166 is degraded, likely via SMALL-RNA-DEGRADING-NUCLEASES1/2, thus reducing miR165/166 ability to silence, via ARGONAUTE1, the transcripts of cell fate-influencing transcription factors. These include PHABULOSA (PHB), which controls meristem activity in the initials and xylem differentiation in the pro-vasculature. During early germination, PHB transcription increases while dynamic, spatially-restricted transcriptional and post-transcriptional mechanisms reduce and confine ARGONAUTE10 accumulation to the provascular cells surrounding the newly-forming xylem axis. Adequate miR165/166 concentrations are thereby channeled along the ARGONAUTE10-deficient yet ARGONAUTE1-proficient axis. Consequently, inversely-correlated miR165/166 and PHB gradients form preferentially along the axis despite ubiquitous PHB transcription and widespread miR165/166 delivery inside the whole vascular cylinder.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas Argonautas , Regulação da Expressão Gênica de Plantas , Meristema , MicroRNAs , Raízes de Plantas , Xilema , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , MicroRNAs/metabolismo , MicroRNAs/genética , Meristema/metabolismo , Meristema/crescimento & desenvolvimento , Meristema/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Argonautas/metabolismo , Proteínas Argonautas/genética , Xilema/metabolismo , Xilema/crescimento & desenvolvimento , Xilema/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética
4.
EMBO J ; 41(10): e109782, 2022 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-35437807

RESUMO

The innate immune receptor RIG-I provides a first line of defense against viral infections. Viral RNAs are recognized by RIG-I's C-terminal domain (CTD), but the RNA must engage the helicase domain to release the signaling CARD (Caspase Activation and Recruitment Domain) domains from their autoinhibitory CARD2:Hel2i interactions. Because the helicase itself lacks RNA specificity, mechanisms to proofread RNAs entering the helicase domain must exist. Although such mechanisms would be crucial in preventing aberrant immune responses by non-specific RNAs, they remain largely uncharacterized to date. This study reveals a previously unknown proofreading mechanism through which RIG-I ensures that the helicase engages RNAs explicitly recognized by the CTD. A crucial part of this mechanism involves the intrinsically disordered CARDs-Helicase Linker (CHL), which connects the CARDs to the helicase subdomain Hel1. CHL uses its negatively charged regions to antagonize incoming RNAs electrostatically. In addition to this RNA gating function, CHL is essential for stabilization of the CARD2:Hel2i interface. Overall, we uncover that the CHL and CARD2:Hel2i interface work together to establish a tunable gating mechanism that allows CTD-chosen RNAs to bind the helicase domain, while at the same time blocking non-specific RNAs. These findings also indicate that CHL could represent a novel target for RIG-I-based therapeutics.


Assuntos
RNA Helicases DEAD-box , RNA de Cadeia Dupla , Proteína DEAD-box 58/genética , Proteína DEAD-box 58/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , DNA Helicases/metabolismo , Imunidade Inata , Estrutura Terciária de Proteína , RNA Viral/genética
5.
Proc Natl Acad Sci U S A ; 120(26): e2219272120, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37307436

RESUMO

Four years after the EAT-Lancet landmark report, worldwide movements call for action to reorient food systems to healthy diets that respect planetary boundaries. Since dietary habits are inherently local and personal, any shift toward healthy and sustainable diets going against this identity will have an uphill road. Therefore, research should address the tension between the local and global nature of the biophysical (health, environment) and social dimensions (culture, economy). Advancing the food system transformation to healthy, sustainable diets transcends the personal control of engaging consumers. The challenge for science is to scale-up, to become more interdisciplinary, and to engage with policymakers and food system actors. This will provide the evidential basis to shift from the current narrative of price, convenience, and taste to one of health, sustainability, and equity. The breaches of planetary boundaries and the environmental and health costs of the food system can no longer be considered externalities. However, conflicting interests and traditions frustrate effective changes in the human-made food system. Public and private stakeholders must embrace social inclusiveness and include the role and accountability of all food system actors from the microlevel to the macrolevel. To achieve this food transformation, a new "social contract," led by governments, is needed to redefine the economic and regulatory power balance between consumers and (inter)national food system actors.


Assuntos
Dieta , Nível de Saúde , Humanos , Alimentos , Biofísica , Governo
6.
Proc Natl Acad Sci U S A ; 120(42): e2307354120, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37812695

RESUMO

Entrainment of dry air into clouds strongly influences cloud optical and precipitation properties and the response of clouds to aerosol perturbations. The response of cloud droplet size distributions to entrainment-mixing is examined in the Pi convection-cloud chamber that creates a turbulent, steady-state cloud. The experiments are conducted by injecting dry air with temperature (Te) and flow rate (Qe) through a flange in the top boundary, into the otherwise well-mixed cloud, to mimic the entrainment-mixing process. Due to the large-scale circulation, the downwind region is directly affected by entrained dry air, whereas the upwind region is representative of the background conditions. Droplet concentration (Cn) and liquid water content (L) decrease in the downwind region, but the difference in the mean diameter of droplets (Dm) is small. The shape of cloud droplet size distributions relative to the injection point is unchanged, to within statistical uncertainty, resulting in a signature of inhomogeneous mixing, as expected for droplet evaporation times small compared to mixing time scales. As Te and Qe of entrained air increase, however, Cn, L, and Dm of the whole cloud system decrease, resulting in a signature of homogeneous mixing. The apparent contradiction is understood as the cloud microphysical responses to entrainment and mixing differing on local and global scales: locally inhomogeneous and globally homogeneous. This implies that global versus local sampling of clouds can lead to seemingly contradictory results for mixing, which informs the long-standing debate about the microphysical response to entrainment and the parameterization of this process for coarse-resolution models.

7.
Proc Natl Acad Sci U S A ; 120(46): e2303640120, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37943837

RESUMO

The COVID-19 pandemic struck societies directly and indirectly, not just challenging population health but disrupting many aspects of life. Different effects of the spreading virus-and the measures to fight it-are reported and discussed in different scientific fora, with hard-to-compare methods and metrics from different traditions. While the pandemic struck some groups more than others, it is difficult to assess the comprehensive impact on social inequalities. This paper gauges social inequalities using individual-level administrative data for Sweden's entire population. We describe and analyze the relative risks for different social groups in four dimensions-gender, education, income, and world region of birth-to experience three types of COVID-19 incidence, as well as six additional negative life outcomes that reflect general health, access to medical care, and economic strain. During the pandemic, the overall population faced severe morbidity and mortality from COVID-19 and saw higher all-cause mortality, income losses and unemployment risks, as well as reduced access to medical care. These burdens fell more heavily on individuals with low income or education and on immigrants. Although these vulnerable groups experienced larger absolute risks of suffering the direct and indirect consequences of the pandemic, the relative risks in pandemic years (2020 and 2021) were conspicuously similar to those in prepandemic years (2016 to 2019).


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Suécia/epidemiologia , Risco , Classe Social
8.
Brief Bioinform ; 24(1)2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36642412

RESUMO

Machine learning-based scoring functions (MLSFs) have become a very favorable alternative to classical scoring functions because of their potential superior screening performance. However, the information of negative data used to construct MLSFs was rarely reported in the literature, and meanwhile the putative inactive molecules recorded in existing databases usually have obvious bias from active molecules. Here we proposed an easy-to-use method named AMLSF that combines active learning using negative molecular selection strategies with MLSF, which can iteratively improve the quality of inactive sets and thus reduce the false positive rate of virtual screening. We chose energy auxiliary terms learning as the MLSF and validated our method on eight targets in the diverse subset of DUD-E. For each target, we screened the IterBioScreen database by AMLSF and compared the screening results with those of the four control models. The results illustrate that the number of active molecules in the top 1000 molecules identified by AMLSF was significantly higher than those identified by the control models. In addition, the free energy calculation results for the top 10 molecules screened out by the AMLSF, null model and control models based on DUD-E also proved that more active molecules can be identified, and the false positive rate can be reduced by AMLSF.


Assuntos
Proteínas , Proteínas/metabolismo , Bases de Dados Factuais , Ligantes , Simulação de Acoplamento Molecular , Ligação Proteica
9.
Annu Rev Psychol ; 75: 495-526, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-37585666

RESUMO

Research in cultural psychology over the last three decades has revealed the profound influence of culture on cognitive, emotional, and motivational processes shaping individuals into active agents. This article aims to show cultural psychology's promise in three key steps. First, we review four notable cultural dimensions believed to underlie cultural variations: independent versus interdependent self, individualism versus collectivism, tightness versus looseness of social norms, and relational mobility. Second, we examine how ecology and geography shape human activities and give rise to organized systems of cultural practices and meanings, called eco-cultural complexes. In turn, the eco-cultural complex of each zone is instrumental in shaping a wide range of psychological processes, revealing a psychological diversity that extends beyond the scope of the current East-West literature. Finally, we examine some of the non-Western cultural zones present today, including Arab, East Asian, Latin American, and South Asian zones, and discuss how they may have contributed, to varying degrees, to the formation of the contemporary Western cultural zone.


Assuntos
Emoções , Motivação , Humanos , Normas Sociais
10.
Proc Natl Acad Sci U S A ; 119(13): e2118244119, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35312365

RESUMO

SignificanceTo date, researchers and practitioners have focused on the academic challenges of underrepresented ethnic groups in the United States. In comparison, Asians have received limited attention, as they are commonly assumed to excel across all educational stages. Six large studies challenge this assumption by revealing that East Asians (but not South Asians) underperform in US law schools and business schools. This is not because East Asians are less academically motivated or less proficient in English but because their low verbal assertiveness is culturally incongruent with the assertiveness prized by US law and business schools. Online classes (via Zoom) mitigated East Asians' underperformance in courses emphasizing assertiveness and class participation. Educators should reexamine pedagogical practices to create a culturally inclusive classroom.


Assuntos
Assertividade , Instituições Acadêmicas , Povo Asiático , Escolaridade , Etnicidade , Humanos , Estados Unidos
11.
Neurogenetics ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38967831

RESUMO

The debate surrounding nature versus nurture remains a central question in neuroscience, psychology, and in psychiatry, holding implications for both aging processes and the etiology of mental illness. Epigenetics can serve as a bridge between genetic predisposition and environmental influences, thus offering a potential avenue for addressing these questions. Epigenetic clocks, in particular, offer a theoretical framework for measuring biological age based on DNA methylation signatures, enabling the identification of disparities between biological and chronological age. This structured review seeks to consolidate current knowledge regarding the relationship between mental disorders and epigenetic age within the brain. Through a comprehensive literature search encompassing databases such as EBSCO, PubMed, and ClinicalTrials.gov, relevant studies were identified and analyzed. Studies that met inclusion criteria were scrutinized, focusing on those with large sample sizes, analyses of both brain tissue and blood samples, investigation of frontal cortex markers, and a specific emphasis on schizophrenia and depressive disorders. Our review revealed a paucity of significant findings, yet notable insights emerged from studies meeting specific criteria. Studies characterized by extensive sample sizes, analysis of brain tissue and blood samples, assessment of frontal cortex markers, and a focus on schizophrenia and depressive disorders yielded particularly noteworthy results. Despite the limited number of significant findings, these studies shed light on the complex interplay between epigenetic aging and mental illness. While the current body of literature on epigenetic aging in mental disorders presents limited significant findings, it underscores the importance of further research in this area. Future studies should prioritize large sample sizes, comprehensive analyses of brain tissue and blood samples, exploration of specific brain regions such as the frontal cortex, and a focus on key mental disorders. Such endeavors will contribute to a deeper understanding of the relationship between epigenetic aging and mental illness, potentially informing novel diagnostic and therapeutic approaches.

12.
Neurobiol Dis ; 201: 106655, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39218360

RESUMO

BACKGROUND: This study aims to identify distinct microbial and functional biomarkers characteristic of body-first or brain-first subtypes of Parkinson's disease (PD). This could illuminate the unique pathogenic mechanisms within these subtypes. METHODS: In this cross-sectional study, we classified 36 well-characterized PD patients into body-first, brain-first, or undetermined subtypes based on the presence of premotor REM sleep behavior disorder (RBD) and cardiac meta-iodobenzylguanidine (MIBG) uptake. We then conducted an in-depth shotgun metagenomic analysis of the gut microbiome for each subtype and compared the results with those from age- and sex-matched healthy controls. RESULTS: Significant differences were found in the gut microbiome of body-first PD patients (n = 15) compared to both brain-first PD patients (n = 9) and healthy controls. The gut microbiome in body-first PD showed a distinct profile, characterized by an increased presence of Escherichia coli and Akkermansia muciniphila, and a decreased abundance of short-chain fatty acid-producing commensal bacteria. These shifts were accompanied by a higher abundance of microbial genes associated with curli protein biosynthesis and a lower abundance of genes involved in putrescine and spermidine biosynthesis. Furthermore, the combined use of premotor RBD and MIBG criteria was more strongly correlated with these microbiome differences than the use of each criterion independently. CONCLUSIONS: Our findings highlight the significant role of dysbiotic and pathogenic gut microbial alterations in body-first PD, supporting the body-first versus brain-first hypothesis. These insights not only reinforce the gut microbiome's potential as a therapeutic target in PD but also suggest the possibility of developing subtype-specific treatment strategies.

13.
Am J Epidemiol ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38957978

RESUMO

The 1918-20 influenza pandemic devastated Alaska's Indigenous populations. We report on quantitative analyses of pandemic deaths due to pneumonia and influenza (P&I) using information from Alaska death certificates dating between 1915 and 1921 (n=7,147). Goals include a reassessment of pandemic death numbers, analysis of P&I deaths beyond 1919, estimates of excess mortality patterns overall and by age using intercensal population estimates based on Alaska's demographic history, and comparisons between Alaska Native (AN) and non-AN residents. Results indicate that ANs experienced 83% of all P&I deaths and 87% of all-cause excess deaths during the pandemic. AN mortality was 8.1 times higher than non-AN mortality. Analyses also uncovered previously unknown mortality peaks in 1920. Both subpopulations showed characteristically high mortality of young adults, possibly due to imprinting with the 1889-90 pandemic virus, but their age-specific mortality patterns were different: non-AN mortality declined after age 25-29 and stayed relatively low for the elderly, while AN mortality increased after age 25-29, peaked at age 40-44, and remained high up to age 64. This suggests a relative lack of exposure to H1-type viruses pre-1889 among AN persons. In contrast, non-AN persons, often temporary residents, may have gained immunity before moving to Alaska.

14.
Am J Transplant ; 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39197591

RESUMO

Ischemia-reperfusion is an unavoidable step of organ transplantation. Development of therapeutics for lung injury during transplantation has proved challenging; understanding lung injury from human data at the single-cell resolution is required to accelerate the development of therapeutics. Donor lung biopsies from 6 human lung transplant cases were collected at the end of cold preservation and 2-hour reperfusion and underwent single-cell RNA sequencing. Donor and recipient origin of cells from the reperfusion timepoint were deconvolved. Gene expression profiles were: (1) compared between each donor cell type between timepoints and (2) compared between donor and recipient cells. Inflammatory responses from donor lung macrophages were found after reperfusion with upregulation of multiple cytokines and chemokines, especially IL-1ß and IL-1α. Significant inflammatory responses were found in alveolar epithelial cells (featured by CXCL8) and lung endothelial cells (featured by IL-6 upregulation). Different inflammatory responses were noted between donor and recipient monocytes and CD8+ T cells. The inflammatory signals and differences between donor and recipient cells observed provide insight into the cellular and molecular mechanisms of ischemia-reperfusion induced lung injury. Further investigations may lead to the development of novel targeted therapeutics.

15.
J Clin Immunol ; 45(1): 3, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39264459

RESUMO

LRBA deficiency is an inborn error of immunity defined by autoimmunity, lymphoproliferation, recurrent infections, cytopenia, and inflammatory bowel disease. Despite recent advances in managing this disease with targeted biologic therapy, haematopoietic stem cell transplant (HSCT) remains the only cure. However, great variability exists between protocols used to transplant patients with LRBA deficiency. We describe a cohort of seven patients with LRBA deficiency who underwent HSCT using a myeloablative, reduced toxicity regime of fludarabine, treosulfan, and thiotepa at two transplantation centres from 2016 to 2019. Data were collected both retrospectively and prospectively, measuring time to engraftment, infectious complications, incidence of graft versus host disease, and post-transplantation chimerism. Six of seven patients survived transplantation, and four of six surviving patients achieving treatment-free survival. We thus recommend that HSCT with fludarabine, treosulfan, and thiotepa-based conditioning be considered in patients with LRBA deficiency.


Assuntos
Bussulfano , Transplante de Células-Tronco Hematopoéticas , Tiotepa , Condicionamento Pré-Transplante , Vidarabina , Vidarabina/análogos & derivados , Vidarabina/uso terapêutico , Humanos , Transplante de Células-Tronco Hematopoéticas/métodos , Bussulfano/análogos & derivados , Bussulfano/uso terapêutico , Condicionamento Pré-Transplante/métodos , Tiotepa/uso terapêutico , Masculino , Feminino , Lactente , Pré-Escolar , Doença Enxerto-Hospedeiro/etiologia , Criança , Estudos Retrospectivos , Resultado do Tratamento , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/terapia
16.
J Comput Chem ; 45(11): 804-819, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38135467

RESUMO

The inability of p-block elements to participate in π-backbonding restricts them from activating small molecules like CO, H2 , and so forth. However, the development of the main group metallomimetics became a new pathway, where the main-group elements like boron can bind and activate small molecules like CO and H2 . The concept of the frustrated Lewis pair, Boron-Boron multiple bonds, and borylene are previously illustrated. Some of these reported classes of boron species can mimic the jobs of the metal complexes. Hence, we have theoretically studied the binding of CO/N2 molecules at B-center of elusive species like sila/germa boryne stabilized by donor base ligands (cAAC)BE(Me)(L), where E  Si, L  cAACMe , NHCMe , PMe3 , E  Ge, L  cAACMe and (NHCMe )BE(Me)(cAACMe )). The substitutional analogues of (cAACR )BSiR1 (cAAC) and E  P, L  cAACMe ) have been studied by density functional theory (DFT), natural bond orbital, QTAIM calculations and energy decomposition analysis (EDA) coupled with natural orbital for chemical valence (NOCV) analyses. The computed bond dissociation energy and inner stability analyses by the EDA-NOCV method showed that the CO molecule can bind at the B-center of the above-mentioned species due to stronger σ-donor ability while binding of N2 has been theoretically predicted to be weak. The energy barrier for the CO binding is estimated to be 13-14 kcal/mol by transition state calculation. The change of partial triple bond character to single bond nature of the BSi bond and the bending of CBSi bond angle of sila-boryne species are the reason for the activation energy. Our study reveals the ability of such species to bind and activate the CO molecule to mimic the transition metal-containing complexes. We have additionally shown that binding of Fe(CO)4 and Ni(CO)3 is feasible at Si-center after binding of CO at the B-center.

17.
Small ; 20(11): e2306615, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37932020

RESUMO

Aqueous zinc-ion batteries (AZIBs) are considered to be a rising star in the large-scale energy storage area because of their low cost and environmental friendliness properties. However, the limited electrochemical performance of the cathode and severe zinc dendrite of the anode severely hinder the practical application of AZIBs. Herein, a novel 3D interconnected VS2 ⊥V4 C3 Tx heterostructure material is prepared via one-step solvothermal method. Morphological and structural characterizations show that VS2 nanosheets are uniformly and dispersedly distributed on the surface of the V4 C3 MXene substrate, which can effectively suppress volume change of the VS2 . Owing to the open heterostructure along with the high conductivity of V4 C3 MXene, the VS2 ⊥V4 C3 Tx cathode shows a high specific capacity of 273.9 mAh g-1 at 1 A g-1 and an excellent rate capability of 143.2 mAh g-1 at 20 A g-1 . The V4 C3 MXene can also effectively suppress zinc dendrite growth when used as protective layer for the Zn anode, making the V4 C3 Tx @Zn symmetric cell with a stable voltage profile for ≈1700 h. Benefitting from the synergistic modification effect of V4 C3 MXene on both the cathode and anode, the VS2 ⊥V4 C3 Tx ||V4 C3 Tx @Zn battery exhibits a long cycling lifespan of 5000 cycles with a capacity of 157.1 mAh g-1 at 5A g-1 .

18.
Small ; 20(27): e2309901, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38299768

RESUMO

Metal sulfides are promising anode materials for sodium-ion batteries (SIBs) due to their structural diversity and high theoretical capacity, but the severe capacity decay and inferior rate capability caused by poor structural stability and sluggish kinetics impede their practical applications. Herein, a cobalt-doped amorphous VS4 wrapped by reduced graphene oxide (i.e., Co0.5-VS4/rGO) is developed through a Co-induced defect engineering strategy to boost the kinetics performances. The as-prepared Co0.5-VS4/rGO demonstrates excellent rate capacities over 10 A g-1 and superior cycling stability at 5 A g-1 over 1600 cycles, which is attributed to the defects formed by Co doping, the formed amorphous structure and the robust rGO substrate. The great features of Co0.5-VS4/rGO anode are further confirmed in sodium-ion capacitors when the active carbon cathode is used. Additionally, the relationships between metal doping, the derived defects, the amorphous structure, and the sodium storage of VS4 are uncovered. This work provides deep insights into preparing amorphous functional materials and also probes the potential applications of metal sulfide-based electrode materials for advanced batteries.

19.
Small ; : e2402935, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38809078

RESUMO

Antimony selenosulfide (Sb2(S,Se)3) has recently emerged as a promising light-absorbing material, attributed to its tunable photovoltaic properties, low toxicity, and robust environmental stability. However, despite these advantages, the current record efficiency for Sb2(S,Se)3 solar cells significantly lags behind their Shockley-Queisser limit, especially when compared to other well-established chalcogenide-based thin-film solar cells, such as CdTe and Cu(In,Ga)Se2. This underperformance primarily arises from the formation of unfavorable defects, predominately located at deep energy levels, which act as recombination centers, thereby limiting the potential for performance enhancement in Sb2(S,Se)3 solar cells. Specifically, deep-level defects, such as sulfur vacancy (VS), have a lower formation energy, leading to severe non-radiative recombination and compromising device performance. To address this challenge, thioacetamide (TA), a sulfur-containing additive is introduced, into the precursor solution for the hydrothermal deposition of Sb2(S,Se)3. This results indicate that the incorporation of TA helps in passivating deep-level defects such as sulfur vacancies and in suppressing the formation of large voids within the Sb2(S,Se)3 absorber. Consequently, Sb2(S,Se)3 solar cells, with reduced carrier recombination and improved film quality, achieved a power conversion efficiency of 9.04%, with notable improvements in open-circuit voltage and fill factor. This work provides deeper insights into the passivation of deep-level donor-like VS defects through the incorporation of a sulfur-containing additive, highlighting pathways to enhance the photovoltaic performance of Sb2(S,Se)3 solar cells.

20.
J Pediatr ; 274: 114154, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38897379

RESUMO

OBJECTIVE: To examine the biomarkers of pharyngoesophageal swallowing during oral feeding sessions in infants undergoing pH-impedance testing and determine whether swallow frequencies are distinct between oral-fed and partially oral-fed infants. STUDY DESIGN: One oral feeding session was performed in 40 infants during pH-impedance studies and measurements included swallowing frequency, multiple swallow rate, air and liquid swallow rates, esophageal swallow clearance time, and gastroesophageal reflux (GER) characteristics. Linear and mixed statistical models were applied to examine the swallowing markers and outcomes. RESULTS: Infants (30.2 ± 4.4 weeks' birth gestation) were evaluated at 41.2 ± 0.4 weeks' postmenstrual age. Overall, 10 675 swallows were analyzed during the oral feeding sessions (19.3 ± 5.4 minutes per infant) and GER events were noted (2.5 ± 0.3 per study). Twenty-four-hour acid reflux index (ARI) was 9.5 ± 2.0%. Differences were noted in oral-fed and partially oral-fed infants for volume consumption (P < .01), consumption rate (P < .01), and length of hospital stay in days (P < .01). Infants with ARI >7% had greater frequency of swallows (P = .01). The oral-fed group had greater ARI (12.7 ± 3.3%, P = .05). CONCLUSIONS: Oropharyngeal swallowing regulatory characteristics decrease over the feeding duration and were different between ARI >7% vs ≤7%. Although GER is less in infants who are partially oral-fed, the neonates with increased acid exposure achieved greater oral intakes and shorter hospitalizations, despite the presence of comorbidities. Pharyngoesophageal stimulation as during consistent feeding or GER events can activate peristaltic responses and rhythms, which may be contributory to the findings.

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