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1.
Nature ; 631(8021): 544-548, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39020036

RESUMEN

A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.


Asunto(s)
Excipientes , Excipientes/química , Proteínas/química , Proteínas/metabolismo , Humanos , Estabilidad Proteica , Liofilización , Hidrogeles/química , Geles/química , Trehalosa/química
2.
Cell ; 154(4): 827-42, 2013 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-23953114

RESUMEN

The epidemic of heart failure has stimulated interest in understanding cardiac regeneration. Evidence has been reported supporting regeneration via transplantation of multiple cell types, as well as replication of postmitotic cardiomyocytes. In addition, the adult myocardium harbors endogenous c-kit(pos) cardiac stem cells (eCSCs), whose relevance for regeneration is controversial. Here, using different rodent models of diffuse myocardial damage causing acute heart failure, we show that eCSCs restore cardiac function by regenerating lost cardiomyocytes. Ablation of the eCSC abolishes regeneration and functional recovery. The regenerative process is completely restored by replacing the ablated eCSCs with the progeny of one eCSC. eCSCs recovered from the host and recloned retain their regenerative potential in vivo and in vitro. After regeneration, selective suicide of these exogenous CSCs and their progeny abolishes regeneration, severely impairing ventricular performance. These data show that c-kit(pos) eCSCs are necessary and sufficient for the regeneration and repair of myocardial damage.


Asunto(s)
Células Madre Adultas/trasplante , Insuficiencia Cardíaca/terapia , Miocitos Cardíacos/citología , Células Madre Adultas/metabolismo , Animales , Células de la Médula Ósea/metabolismo , Proteínas Fluorescentes Verdes/análisis , Corazón/fisiología , Insuficiencia Cardíaca/inducido químicamente , Humanos , Isoproterenol , Masculino , Ratones , Miocitos Cardíacos/química , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratas , Factor de Células Madre/metabolismo
3.
Mol Cell ; 77(6): 1350-1364.e6, 2020 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-31999955

RESUMEN

DNA methylation of enhancers is dynamic, cell-type specific, and vital for cell fate progression. However, current models inadequately define its role within the hierarchy of gene regulation. Analysis of independent datasets shows an unanticipated overlap between DNA methylation and chromatin accessibility at enhancers of steady-state stem cells, suggesting that these two opposing features might exist concurrently. To define their temporal relationship, we developed ATAC-Me, which probes accessibility and methylation from single DNA library preparations. We identified waves of accessibility occurring rapidly across thousands of myeloid enhancers in a monocyte-to-macrophage cell fate model. Prolonged methylation states were observed at a majority of these sites, while transcription of nearby genes tracked closely with accessibility. ATAC-Me uncovers a significant disconnect between chromatin accessibility, DNA methylation status, and gene activity. This unexpected observation highlights the value of ATAC-Me in constructing precise molecular timelines for understanding the role of DNA methylation in gene regulation.


Asunto(s)
Diferenciación Celular , Linaje de la Célula , Cromatina/genética , Metilación de ADN , Regulación del Desarrollo de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Secuencias Reguladoras de Ácidos Nucleicos , Sitios de Unión , Reprogramación Celular , Redes Reguladoras de Genes , Humanos , Macrófagos/citología , Macrófagos/metabolismo , Monocitos/citología , Monocitos/metabolismo
4.
Proc Natl Acad Sci U S A ; 121(16): e2318600121, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38588431

RESUMEN

Antibiotics are considered one of the most important contributions to clinical medicine in the last century. Due to the use and overuse of these drugs, there have been increasing frequencies of infections with resistant pathogens. One form of resistance, heteroresistance, is particularly problematic; pathogens appear sensitive to a drug by common susceptibility tests. However, upon exposure to the antibiotic, resistance rapidly ascends, and treatment fails. To quantitatively explore the processes contributing to the emergence and ascent of resistance during treatment and the waning of resistance following cessation of treatment, we develop two distinct mathematical and computer-simulation models of heteroresistance. In our analysis of the properties of these models, we consider the factors that determine the response to antibiotic-mediated selection. In one model, heteroresistance is progressive, with each resistant state sequentially generating a higher resistance level. In the other model, heteroresistance is non-progressive, with a susceptible population directly generating populations with different resistance levels. The conditions where resistance will ascend in the progressive model are narrower than those of the non-progressive model. The rates of reversion from the resistant to the sensitive states are critically dependent on the transition rates and the fitness cost of resistance. Our results demonstrate that the standard test used to identify heteroresistance is insufficient. The predictions of our models are consistent with empirical results. Our results demand a reevaluation of the definition and criteria employed to identify heteroresistance. We recommend that the definition of heteroresistance should include a consideration of the rate of return to susceptibility.


Asunto(s)
Antibacterianos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Dinámica Poblacional , Pruebas de Sensibilidad Microbiana
5.
PLoS Biol ; 21(9): e3002317, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37747887

RESUMEN

Translational control is critical for cell fate transitions during development, lineage specification, and tumorigenesis. Here, we show that the transcription factor double homeobox protein 4 (DUX4), and its previously characterized transcriptional program, broadly regulates translation to change the cellular proteome. DUX4 is a key regulator of zygotic genome activation in human embryos, whereas misexpression of DUX4 causes facioscapulohumeral muscular dystrophy (FSHD) and is associated with MHC-I suppression and immune evasion in cancer. We report that translation initiation and elongation factors are disrupted downstream of DUX4 expression in human myoblasts. Genome-wide translation profiling identified mRNAs susceptible to DUX4-induced translation inhibition, including those encoding antigen presentation factors and muscle lineage proteins, while DUX4-induced mRNAs were robustly translated. Endogenous expression of DUX4 in human FSHD myotubes and cancer cell lines also correlated with reduced protein synthesis and MHC-I presentation. Our findings reveal that DUX4 orchestrates cell state conversion by suppressing the cellular proteome while maintaining translation of DUX4-induced mRNAs to promote an early developmental program.


Asunto(s)
Proteínas de Homeodominio , Distrofia Muscular Facioescapulohumeral , Factores de Transcripción , Humanos , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular Facioescapulohumeral/genética , Distrofia Muscular Facioescapulohumeral/metabolismo , Proteoma/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
J Immunol ; 213(3): 317-327, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38905107

RESUMEN

Obesity is associated with increased morbidity and mortality during bacterial pneumonia. Cyclooxygenase-2 (COX-2) and PGE2 have been shown to be upregulated in patients who are obese. In this study, we investigated the role of obesity and PGE2 in bacterial pneumonia and how inhibition of PGE2 improves antibacterial functions of macrophages. C57BL/6J male and female mice were fed either a normal diet (ND) or high-fat diet (HFD) for 16 wk. After this time, animals were infected with Pseudomonas aeruginosa in the lung. In uninfected animals, alveolar macrophages were extracted for either RNA analysis or to be cultured ex vivo for functional analysis. HFD resulted in changes in immune cell numbers in both noninfected and infected animals. HFD animals had increased bacterial burden compared with ND animals; however, male HFD animals had higher bacterial burden compared with HFD females. Alveolar macrophages from HFD males had decreased ability to phagocytize and kill bacteria and were shown to have increased cyclooxygenase-2 and PGE2. Treating male, but not female, alveolar macrophages with PGE2 leads to increases in cAMP and decreased bacterial phagocytosis. Treatment with lumiracoxib-conjugated nanocarriers targeting alveolar macrophages improves bacterial phagocytosis and clearance in both ND and HFD male animals. Our study highlights that obesity leads to worse morbidity during bacterial pneumonia in male mice because of elevated PGE2. In addition, we uncover a sex difference in both obesity and infection, because females produce high basal PGE2 but because of a failure to signal via cAMP do not display impaired phagocytosis.


Asunto(s)
Dinoprostona , Macrófagos Alveolares , Ratones Endogámicos C57BL , Obesidad , Neumonía Bacteriana , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Regulación hacia Arriba , Animales , Femenino , Masculino , Macrófagos Alveolares/inmunología , Ratones , Dinoprostona/metabolismo , Pseudomonas aeruginosa/inmunología , Obesidad/inmunología , Infecciones por Pseudomonas/inmunología , Neumonía Bacteriana/inmunología , Regulación hacia Arriba/inmunología , Dieta Alta en Grasa/efectos adversos , Ciclooxigenasa 2/metabolismo , Fagocitosis/inmunología , Factores Sexuales
7.
Cell ; 146(6): 1029-41, 2011 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-21925323

RESUMEN

During germ cell and preimplantation development, mammalian cells undergo nearly complete reprogramming of DNA methylation patterns. We profiled the methylomes of human and chimp sperm as a basis for comparison to methylation patterns of ESCs. Although the majority of promoters escape methylation in both ESCs and sperm, the corresponding hypomethylated regions show substantial structural differences. Repeat elements are heavily methylated in both germ and somatic cells; however, retrotransposons from several subfamilies evade methylation more effectively during male germ cell development, whereas other subfamilies show the opposite trend. Comparing methylomes of human and chimp sperm revealed a subset of differentially methylated promoters and strikingly divergent methylation in retrotransposon subfamilies, with an evolutionary impact that is apparent in the underlying genomic sequence. Thus, the features that determine DNA methylation patterns differ between male germ cells and somatic cells, and elements of these features have diverged between humans and chimpanzees.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Pan troglodytes/genética , Animales , Centrómero/metabolismo , Células Madre Embrionarias/metabolismo , Genómica , Humanos , Masculino , Primates/genética , Regiones Promotoras Genéticas , Espermatozoides/metabolismo
9.
Nature ; 583(7816): 400-405, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32669695

RESUMEN

Mechanical interlocking of molecules (catenation) is a nontrivial challenge in modern synthetic chemistry and materials science1,2. One strategy to achieve catenation is the design of pre-annular molecules that are capable of both efficient cyclization and of pre-organizing another precursor to engage in subsequent interlocking3-9. This task is particularly difficult when the annular target is composed of a large ensemble of molecules, that is, when it is a supramolecular assembly. However, the construction of such unprecedented assemblies would enable the visualization of nontrivial nanotopologies through microscopy techniques, which would not only satisfy academic curiosity but also pave the way to the development of materials with nanotopology-derived properties. Here we report the synthesis of such a nanotopology using fibrous supramolecular assemblies with intrinsic curvature. Using a solvent-mixing strategy, we kinetically organized a molecule that can elongate into toroids with a radius of about 13 nanometres. Atomic force microscopy on the resulting nanoscale toroids revealed a high percentage of catenation, which is sufficient to yield 'nanolympiadane'10, a nanoscale catenane composed of five interlocked toroids. Spectroscopic and theoretical studies suggested that this unusually high degree of catenation stems from the secondary nucleation of the precursor molecules around the toroids. By modifying the self-assembly protocol to promote ring closure and secondary nucleation, a maximum catenation number of 22 was confirmed by atomic force microscopy.

10.
Hum Mol Genet ; 32(11): 1864-1874, 2023 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-36728804

RESUMEN

Human DUX4 and its mouse ortholog Dux are normally expressed in the early embryo-the 4-cell or 2-cell cleavage stage embryo, respectively-and activate a portion of the first wave of zygotic gene expression. DUX4 is epigenetically suppressed in nearly all somatic tissue, whereas facioscapulohumeral dystrophy (FSHD)-causing mutations result in its aberrant expression in skeletal muscle, transcriptional activation of the early embryonic program and subsequent muscle pathology. Although DUX4 and Dux both activate an early totipotent transcriptional program, divergence of their DNA binding domains limits the use of DUX4 expressed in mice as a preclinical model for FSHD. In this study, we identify the porcine DUXC messenger ribonucleic acid expressed in early development and show that both pig DUXC and human DUX4 robustly activate a highly similar early embryonic program in pig muscle cells. These results support further investigation of pig preclinical models for FSHD.


Asunto(s)
Distrofia Muscular Facioescapulohumeral , Humanos , Animales , Ratones , Porcinos , Distrofia Muscular Facioescapulohumeral/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Musculares/metabolismo , Músculo Esquelético/metabolismo
11.
Hum Mol Genet ; 32(5): 709-719, 2023 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-35899434

RESUMEN

Childhood socioeconomic position (SEP) is a major determinant of health and well-being across the entire life course. To effectively prevent and reduce health risks related to SEP, it is critical to better understand when and under what circumstances socioeconomic adversity shapes biological processes. DNA methylation (DNAm) is one such mechanism for how early life adversity 'gets under the skin'. In this study, we evaluated the dynamic relationship between SEP and DNAm across childhood using data from 946 mother-child pairs in the Avon Longitudinal Study of Parents and Children. We assessed six SEP indicators spanning financial, occupational and residential domains during very early childhood (ages 0-2), early childhood (ages 3-5) and middle childhood (ages 6-7). Epigenome-wide DNAm was measured at 412 956 cytosine-guanines (CpGs) from peripheral blood at age 7. Using an innovative two-stage structured life-course modeling approach, we tested three life-course hypotheses for how SEP shapes DNAm profiles-accumulation, sensitive period and mobility. We showed that changes in the socioeconomic environment were associated with the greatest differences in DNAm, and that middle childhood may be a potential sensitive period when socioeconomic instability is especially important in shaping DNAm. Top SEP-related DNAm CpGs were overrepresented in genes involved in pathways important for neural development, immune function and metabolic processes. Our findings highlight the importance of socioeconomic stability during childhood and if replicated, may emphasize the need for public programs to help children and families experiencing socioeconomic instability and other forms of socioeconomic adversity.


Asunto(s)
Metilación de ADN , Genoma , Niño , Humanos , Preescolar , Recién Nacido , Lactante , Estudios Longitudinales , Factores Socioeconómicos , Epigenoma , Epigénesis Genética
12.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-35042819

RESUMEN

Inspired by the intriguing adaptivity of natural life, such as squids and flowers, we propose a series of dynamic and responsive multifunctional devices based on multiscale structural design, which contain metal nanocoating layers overlaid with other micro-/nanoscale soft or rigid layers. Since the optical/photothermal properties of a metal nanocoating are thickness dependent, metal nanocoatings with different thicknesses were chosen to integrate with other structural design elements to achieve dynamic multistimuli responses. The resultant devices demonstrate 1) strain-regulated cracked and/or wrinkled topography with tunable light-scattering properties, 2) moisture/photothermal-responsive structural color coupled with wrinkled surface, and 3) mechanically controllable light-shielding properties attributed to the strain-dependent crack width of the nanocoating. These devices can adapt external stimuli, such as mechanical strain, moisture, light, and/or heat, into corresponding changes of optical signals, such as transparency, reflectance, and/or coloration. Therefore, these devices can be applied as multistimuli-responsive encryption devices, smart windows, moisture/photothermal-responsive dynamic optics, and smartphone app-assisted pressure-mapping sensors. All the devices exhibit high reversibility and rapid responsiveness. Thus, this hybrid system containing ultrathin metal nanocoatings holds a unique design flexibility and adaptivity and is promising for developing next-generation multifunctional devices with widespread application.

13.
J Proteome Res ; 23(7): 2542-2551, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38869849

RESUMEN

The application of innovative spatial proteomics techniques, such as those based upon matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technology, has the potential to impact research in the field of nephropathology. Notwithstanding, the possibility to apply this technology in more routine diagnostic contexts remains limited by the alternative fixatives employed by this ultraspecialized diagnostic field, where most nephropathology laboratories worldwide use bouin-fixed paraffin-embedded (BFPE) samples. Here, the feasibility of performing MALDI-MSI on BFPE renal tissue is explored, evaluating variability within the trypsin-digested proteome as a result of different preanalytical conditions and comparing them with the more standardized formalin-fixed paraffin-embedded (FFPE) counterparts. A large proportion of the features (270, 68.9%) was detected in both BFPE and FFPE renal samples, demonstrating only limited variability in signal intensity (10.22-10.06%). Samples processed with either fixative were able to discriminate the principal parenchyma regions along with diverse renal substructures, such as glomeruli, tubules, and vessels. This was observed when performing an additional "stress test", showing comparable results in both BFPE and FFPE samples when the distribution of several amyloid fingerprint proteins was mapped. These results suggest the utility of BFPE tissue specimens in MSI-based nephropathology research, further widening their application in this field.


Asunto(s)
Estudios de Factibilidad , Formaldehído , Riñón , Adhesión en Parafina , Proteómica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Fijación del Tejido , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Proteómica/métodos , Humanos , Riñón/química , Riñón/patología , Riñón/metabolismo , Formaldehído/química , Enfermedades Renales/patología , Enfermedades Renales/metabolismo , Enfermedades Renales/diagnóstico , Fijadores/química , Proteoma/análisis
14.
Clin Infect Dis ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38767234

RESUMEN

BACKGROUND: We aimed to test the hypothesis that development of metastatic infection represents a distinct clinical endpoint from death due to SAB. METHODS: We conducted a retrospective observational study of adults with SAB between 20/12/2019 and 23/08/2022 (n=464). Simple logistic regression, odds ratios, and z-scores were used to compare host, clinical and microbiologic features. RESULTS: Co-occurrence of attributable mortality and metastatic infection was infrequent. Charlson Comorbidity Index and age were strongly associated with attributable mortality, but not metastatic infection. We compared patients with fatal SAB (without clinically-apparent metastatic complications, 14·4% of cohort), metastatic SAB (without attributable mortality, 22·2%), neither complication (56·7%), and overlapping fatal/metastatic SAB (6·7%). Compared to SAB without complications, fatal SAB was specifically associated with older age and multi-morbidity. Metastatic SAB was specifically associated with community acquisition, persistent fever, persistent bacteraemia, and recurrence. Endocarditis was over-represented in the fatal/metastatic SAB overlap group, which shared patient characteristics with fatal SAB. In contrast to other (predominantly musculoskeletal) metastatic complications, endocarditis was associated with increased mortality, with death occurring in older multi-morbid patients later after SAB onset. CONCLUSIONS: Patients with SAB experience distinct clinical endpoints: (i) early death, associated with multi-morbidity and age; (ii) metastatic (predominantly musculoskeletal) SAB; (iii) endocarditis, associated with late death occurring in older people with multi-morbidity, and (iv) bacteraemia without complications. These distinctions could be important for selecting appropriate outcomes in clinical trials: different interventions might be required to reduce mortality vs. improve clinical response in patients with metastatic SAB.

15.
Small ; 20(22): e2308672, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38155506

RESUMEN

Layered 2D transition metal dichalcogenides (TMDs) have been suggested as efficient substitutes for Pt-group metal electrocatalysts in the hydrogen evolution reaction (HER). However, poor catalytic activities in neutral and alkaline electrolytes considerably hinder their practical applications. Furthermore, the weak adhesion between TMDs and electrodes often impedes long-term durability and thus requires a binder. Here, a universal platform is reported for robust dual-atom doped 2D electrocatalysts with superior HER performance over a wide pH range media. V:Co-ReS2 on a wafer scale is directly grown on oxidized Ti foil by a liquid-phase precursor-assisted approach and subsequently used as highly efficient electrocatalysts. The catalytic performance surpasses that of Pt group metals in a high current regime (≥ 100 mA cm-2) at pH ≥ 7, with a high durability of more than 70 h in all media at 200 mA cm-2. First-principles calculations reveal that V:Co dual doping in ReS2 significantly reduces the water dissociation barrier and simultaneously enables the material to achieve the thermoneutral Gibbs free energy for hydrogen adsorption.

16.
Acc Chem Res ; 56(9): 1031-1042, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-37068158

RESUMEN

There has been a recent surge of advances in biomolecular assays based on the measurement of discrete molecular targets as opposed to signals averaged across molecular ensembles. Many of these "digital" assay designs derive from now-mature technologies involving single-molecule imaging and microfluidics and provide an assortment of new modalities to quantify nucleic acids and proteins in biospecimens such as blood and tissue homogenates. A primary new benefit is the robust detection of trace analytes at attomolar to femtomolar concentrations for which many ensemble assays cannot distinguish signals above noise levels. In addition, multiple biomolecules can be differentiated within a mixture using optical barcodes, with much faster and simpler readouts compared with sequencing methods. In ideal digital assays, signals should, in theory, further represent absolute molecular counts, rather than relative levels, eliminating the need for calibration standards that are the mainstay of typical assays. Several digital assay platforms have now been commercialized but challenges hinder the adoption and diversification of these new formats, as there are broad needs to balance sensitivity and dynamic range of detection, increase analyte multiplexing, improve sample throughput, and reduce cost. Our lab and others have developed technologies to address these challenges by redesigning molecular probes and labels, improving molecular transport within detection focal volumes, and applying solution-based readout methods in flow.This Account describes the principles, formats, and design constraints of digital biomolecular assays that apply optical labels toward the goal of simple and routine target counting that may ultimately approach absolute readout standards. The primary challenges can be understood from fundamental concepts in thermodynamics and kinetics of association reactions, mass transport, and discrete statistics. Major advances include (1) new inorganic nanocrystal probes for more robust counting compared with dyes, (2) diverse molecular amplification tools that endow attachment of numerous labels to single targets, (3) specialized surfaces with patterned features for electromagnetic coupling to labels for signal amplification, (4) surface capture enhancement methods to concentrate targets through disruption of diffusion depletion zones, and (5) flow counting in which analytes are rapidly counted in solution without pull-down to a surface. Further progress and integration of these tools for biomolecular counting could improve the precision of laboratory measurements in life sciences research and benefit clinical diagnostic assays for low abundance biomarkers in limiting biospecimen volumes that are out of reach of traditional ensemble-level bioassays.


Asunto(s)
Ácidos Nucleicos , Proteínas , Colorantes , Microfluídica , Biomarcadores
17.
NMR Biomed ; : e5161, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38715469

RESUMEN

Achieving high-resolution and high signal-to-noise ratio (SNR) in vivo metabolic imaging via fast magnetic resonance spectroscopic imaging (MRSI) has been a longstanding challenge. This study combines the methods of relaxation enhancement (RE) and subspace imaging for the first time, enabling high-resolution and high-SNR in vivo MRSI of rodent brains at 9.4 T. Specifically, an RE-based chemical shift imaging sequence, which combines a frequency-selective pulse to excite only the metabolite frequencies with minimum perturbation of the water spins and a pair of adiabatic pulses to spatially localize the slice of interest, is designed and evaluated in vivo. This strategy effectively shortens the apparent T1 of metabolites, thereby increasing the SNR during relatively short repetition time ((TR) compared with acquisitions with only spatially selective wideband excitations, and does not require water suppression. The SNR was further enhanced via a state-of-the-art subspace reconstruction method. A novel subspace learning strategy tailored for 9.4 T and RE acquisitions is developed. In vivo, high-resolution (e.g., voxel size of 0.6 × 0.6 × 1.5 mm3) MRSI of both healthy mouse brains and a glioma-bearing mouse brain in 12.5 min has been demonstrated.

18.
Chemistry ; 30(25): e202400544, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38407499

RESUMEN

Light can be used to design stimuli-responsive systems. We induce transient changes in the assembly of a low molecular weight gelator solution using a merocyanine photoacid. Through our approach, reversible viscosity changes can be achieved via irradiation, delivering systems where flow can be controlled non-invasively on demand.

19.
Psychol Med ; : 1-8, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38818779

RESUMEN

BACKGROUND: Depression is a common mental health disorder that often starts during adolescence, with potentially important future consequences including 'Not in Education, Employment or Training' (NEET) status. METHODS: We took a structured life course modeling approach to examine how depressive symptoms during adolescence might be associated with later NEET status, using a high-quality longitudinal data resource. We considered four plausible life course models: (1) an early adolescent sensitive period model where depressive symptoms in early adolescence are more associated with later NEET status relative to exposure at other stages; (2) a mid adolescent sensitive period model where depressive symptoms during the transition from compulsory education to adult life might be more deleterious regarding NEET status; (3) a late adolescent sensitive period model, meaning that depressive symptoms around the time when most adults have completed their education and started their careers are the most strongly associated with NEET status; and (4) an accumulation of risk model which highlights the importance of chronicity of symptoms. RESULTS: Our analysis sample included participants with full information on NEET status (N = 3951), and the results supported the accumulation of risk model, showing that the odds of NEET increase by 1.015 (95% CI 1.012-1.019) for an increase of 1 unit in depression at any age between 11 and 24 years. CONCLUSIONS: Given the adverse implications of NEET status, our results emphasize the importance of supporting mental health during adolescence and early adulthood, as well as considering specific needs of young people with re-occurring depressed mood.

20.
Artículo en Inglés | MEDLINE | ID: mdl-38613494

RESUMEN

BACKGROUND: Adverse childhood experiences (ACEs) are well-established risk factors for self-harm and depression. However, despite their high comorbidity, there has been little focus on the impact of developmental timing and the duration of exposure to ACEs on co-occurring self-harm and depression. METHODS: Data were utilised from over 22,000 children and adolescents participating in three UK cohorts, followed up longitudinally for 14-18 years: the Avon Longitudinal Study of Parents and Children (ALSPAC), the Millennium Cohort Study (MCS) and the Environmental Risk (E-Risk) Longitudinal Twin Study. Multinomial logistic regression models estimated associations between each ACE type and a four-category outcome: no self-harm or depression, self-harm alone, depression alone and self-harm with co-occurring depression. A structured life course modelling approach was used to examine whether the accumulation (duration) of exposure to each ACE, or a critical period (timing of ACEs) had the strongest effects on self-harm and depression in adolescence. RESULTS: The majority of ACEs were associated with co-occurring self-harm and depression, with consistent findings across cohorts. The importance of timing and duration of ACEs differed across ACEs and across cohorts. For parental mental health problems, longer duration of exposure was strongly associated with co-occurring self-harm and depression in both ALSPAC (adjusted OR: 1.18, 95% CI: 1.10-1.25) and MCS (1.18, 1.11-1.26) cohorts. For other ACEs in ALSPAC, exposure in middle childhood was most strongly associated with co-occurring self-harm and depression, and ACE occurrence in early childhood and adolescence was more important in the MCS. CONCLUSIONS: Efforts to mitigate the impact of ACEs should start in early life with continued support throughout childhood, to prevent long-term exposure to ACEs contributing to risk of self-harm and depression in adolescence.

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