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1.
JAMA Health Forum ; 5(8): e241801, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39093586

RESUMO

This Viewpoint describes the need for more health care organizations to include disability accessibility information on their websites and to improve physical access for patients with disabilities.


Assuntos
Acesso à Internet , Humanos , Acesso à Informação , Disparidades em Assistência à Saúde
2.
bioRxiv ; 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38948703

RESUMO

Background: Metabolic remodeling is a hallmark of the failing heart. Oncometabolic stress during cancer increases the activity and abundance of the ATP-dependent citrate lyase (ACL, Acly ), which promotes histone acetylation and cardiac adaptation. ACL is critical for the de novo synthesis of lipids, but how these metabolic alterations contribute to cardiac structural and functional changes remains unclear. Methods: We utilized human heart tissue samples from healthy donor hearts and patients with hypertrophic cardiomyopathy. Further, we used CRISPR/Cas9 gene editing to inactivate Acly in cardiomyocytes of MyH6-Cas9 mice. In vivo, positron emission tomography and ex vivo stable isotope tracer labeling were used to quantify metabolic flux changes in response to the loss of ACL. We conducted a multi-omics analysis using RNA-sequencing and mass spectrometry-based metabolomics and proteomics. Experimental data were integrated into computational modeling using the metabolic network CardioNet to identify significantly dysregulated metabolic processes at a systems level. Results: Here, we show that in mice, ACL drives metabolic adaptation in the heart to sustain contractile function, histone acetylation, and lipid modulation. Notably, we show that loss of ACL increases glucose oxidation while maintaining fatty acid oxidation. Ex vivo isotope tracing experiments revealed a reduced efflux of glucose-derived citrate from the mitochondria into the cytosol, confirming that citrate is required for reductive metabolism in the heart. We demonstrate that YAP inactivation facilitates ACL deficiency. Computational flux analysis and integrative multi-omics analysis indicate that loss of ACL induces alternative isocitrate dehydrogenase 1 flux to compensate. Conclusions: This study mechanistically delineates how cardiac metabolism compensates for suppressed citrate metabolism in response to ACL loss and uncovers metabolic vulnerabilities in the heart.

3.
bioRxiv ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39005369

RESUMO

Accurate quantification of tau binding from 18 F-PI-2620 PET requires kinetic modeling and an input function. Here, we implemented a non-invasive Image-derived input function (IDIF) derived using the state-of-the-art total-body uEXPLORER PET/CT scanner to quantify tau binding and tracer delivery rate from 18 F-PI-2620 in the brain. Additionally, we explored the impact of scan duration on the quantification of kinetic parameters. Total-body PET dynamic data from 15 elderly participants were acquired. Time-activity curves from the grey matter regions of interest (ROIs) were fitted to the two-tissue compartmental model (2TCM) using a subject-specific IDIF derived from the descending aorta. ROI-specific kinetic parameters were estimated for different scan durations ranging from 10 to 90 minutes. Logan graphical analysis was also used to estimate the total distribution volume (V T ). Differences in kinetic parameters were observed between ROIs, including significant reduction in tracer delivery rate (K 1 ) in the medial temporal lobe. All kinetic parameters remained relatively stable after the 60-minute scan window across all ROIs, with K 1 showing high stability after 30 minutes of scan duration. Excellent correlation was observed between V T estimated using 2TCM and Logan plot analysis. This study demonstrated the utility of IDIF with total-body PET in investigating 18 F-PI-2620 kinetics in the brain.

4.
Oecologia ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009889

RESUMO

Intense disturbances such as hurricanes may drastically affect ecosystems, producing both acute and long-term changes along coastlines. By disrupting human activities (e.g., fishing), hurricanes can provide an opportunity to quantify the effects of these activities on coastal ecosystems. We performed predator-exclusion experiments on oyster reefs in 2016, one-year before a category-4 hurricane ("Harvey") and again in 2018 one-year post-hurricane where the storm made landfall. Additionally, we examined 8 years (2011-2018) of fisheries-independent data to gauge how fishing pressure and fish populations were affected by the storm in three locations that varied in storm impacts. In the month following Hurricane Harvey, fishing effort dropped by 90% in the area with wind and flooding damage, and predatory fish species commonly targeted by anglers were 300% more abundant than the year prior to the hurricane. The locations without damage to fishing infrastructure did not experience declines in fishing pressure or changes in fish abundance, regardless of flooding disturbance. Reef fish and invertebrate communities directly affected by the storm were significantly different after the hurricane and were ~ 30% more diverse. With low fishing pressure, sportfish CPUE were 1.7-6.9 × higher immediately after the hurricane. Intermediate consumers, such as crabs that prey on oysters, were 45% less abundant and 10% smaller. These results indicate that hurricanes can temporarily disrupt human-ecosystem linkages and reconstitute top-down control by sportfish in estuarine food webs. Disturbance events that interrupt or weaken those interactions may yield indirect ecological benefits and provide insights into the effects of human activities on food webs.

5.
Genet Med ; : 101212, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39011769

RESUMO

INTRODUCTION: Klinefelter syndrome (KS), a sex chromosome aneuploidy, is associated with a 47,XXY chromosomal complement and is diagnosed in ∼1:600 live male births. Individuals with a 46,XX cell line in addition to 47,XXY are less common with a limited number of published case reports. METHODOLOGY: To better understand the implications of a 47,XXY/46,XX karyotype, we conducted a retrospective, multi-center analysis of the cytogenetic findings and associated clinical records of 34 patients diagnosed with this SCA across 14 institutions. RESULTS: Presence of the XX cell line ranged from 5-98% in patient specimens. Phenotypes also exhibited significant heterogeneity with some reporting a single reason for referral and others presenting with a constellation of symptoms, including ambiguous genitalia and ovotestes. Ovotestes were present in 12% of individuals in this cohort, who had a significantly higher percentage of XX cells. Notably, two patients were assigned female sex at birth DISCUSSION: These findings highlight the variability of the clinical phenotypes associated with this SCA as well as the challenges of clinical management for this population. Karyotype or FISH analysis, which offer single-cell resolution, rather than chromosomal microarray or molecular testing, is the ideal test strategy in these instances as mosaicism can occur at low levels.

6.
Cureus ; 16(6): e63315, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38947138

RESUMO

Severe aortic stenosis (AS) significantly elevates cardiovascular risk, predisposing patients to high-degree atrioventricular (AV) block and life-threatening tachyarrhythmias, including torsades de pointes (TdP). This case report presents a patient with severe AS who developed high-degree AV block and, subsequently, TdP, highlighting the interplay between bradycardia and mechanisms that trigger ventricular tachycardias. The case underscores the importance of identifying and managing these risk factors to improve patient outcomes.

7.
J Med Chem ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949959

RESUMO

HDAC8 plays crucial roles in biological processes, from gene regulation to cell motility, making it a highly desirable target for therapeutic intervention. HDAC8 also has deacetylase-independent activity which cannot be blocked by a conventional inhibitor. In this study, we report the discovery of YX862, a highly potent and selective hydrazide-based HDAC8-proteolysis targeting chimera (PROTAC) degrader. The selectivity is achieved through rational design of the warhead to spare HDAC3 activity from the previous HDAC3/8 dual degrader YX968. We demonstrate that the degradation of HDAC8 by YX862 increases acetylation levels of its nonhistone substrates such as SMC3 without significantly triggering histone PTM, supporting HDAC8's major role in nonhistone PTM regulation. YX862 exhibits promising on-target antiproliferative activity against DLBCL cells with higher potency than the HDAC8 selective inhibitor PCI-34051. As a selective HDAC8 degrader that avoids pan-HDAC inhibition, YX862 represents a valuable tool for exploring the biological and therapeutic potential of HDAC8.

8.
J Clin Virol ; 174: 105705, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39002309

RESUMO

BACKGROUND: Epstein-Barr Virus (EBV) is associated with lung disease in immunocompromised patients, particularly transplant recipients. EBV DNA testing of lower respiratory tract specimens may have diagnostic utility. METHODS: This was a retrospective, observational study of all patients with bronchoalveolar lavage (BAL) fluids submitted for EBV qPCR testing from February 2016 to June 2022 at the Stanford Clinical Virology Laboratory. RESULTS: There were 140 patients that underwent 251 EBV qPCR BAL tests (median 1; range 1 - 10). These patients had a mean age of 15.9 years (standard deviation, 15.1 years) and 50 % were female. Transplant recipients accounted for 67.1 % (94/140) of patients, including 67.0 % (63/94) solid organ transplant (SOT) and 33.0 % (31/94) hematopoietic cell transplant. Diagnostic testing was performed more commonly than surveillance testing [57.0 % (143/251) v. 43.0 % (108/251)]; 96.2 % (104/108) of surveillance samples were from lung transplant recipients. Excluding internal control failures, 34.7 % (83/239) of BAL had detectable EBV DNA, encompassing a wide range of viral loads (median=3.03 log10 IU/mL, range 1.44 to 6.06). Overall agreement of EBV DNA in BAL compared to plasma was 74.1 % [117/158; 95 % confidence interval (CI): 66.5 % to 80.7 %], with a kappa coefficient of 0.44 (95 % CI: 0.30 to 0.57). Only 20.1 % (48/239) of results were discussed in a subsequent clinical note, and one result (0.4 %; 1/239) changed clinical management. CONCLUSIONS: EBV qPCR testing on BAL offers limited clinical impact. Additional biomarkers are required to improve the diagnosis of EBV-associated lung diseases.

9.
iScience ; 27(7): 110187, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38989451

RESUMO

Intratumoral heterogeneity is common in cancer, particularly in sarcomas like undifferentiated pleomorphic sarcoma (UPS), where individual cells demonstrate a high degree of cytogenic diversity. Previous studies showed that a small subset of cells within UPS, known as the metastatic clone (MC), as responsible for metastasis. Using a CRISPR-based genomic screen in-vivo, we identified the COMPASS complex member Setd1a as a key regulator maintaining the metastatic phenotype of the MC in murine UPS. Depletion of Setd1a inhibited metastasis development in the MC. Transcriptome and chromatin sequencing revealed COMPASS complex target genes in UPS, such as Cxcl10, downregulated in the MC. Deleting Cxcl10 in non-MC cells increased their metastatic potential. Treating mice with human UPS xenografts with a COMPASS complex inhibitor suppressed metastasis without affecting tumor growth in the primary tumor. Our data identified an epigenetic program in a subpopulation of sarcoma cells that maintains metastatic potential.

11.
JAMA Oncol ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949926

RESUMO

Importance: Prostate-specific membrane antigen (PSMA) demonstrates overexpression in prostate cancer and correlates with tumor aggressiveness. PSMA positron emission tomography (PET) is superior to conventional imaging for the metastatic staging of prostate cancer per current research but studies of second-generation PSMA PET radioligands for locoregional staging are limited. Objective: To determine the accuracy of fluorine-18 PSMA-1007 PET/computed tomography (18F-PSMA-1007 PET/CT) compared to multiparametric magnetic resonance imaging (MRI) in the primary locoregional staging of intermediate-risk and high-risk prostate cancers. Design, Setting, and Participants: The Next Generation Trial was a phase 2 prospective validating paired cohort study assessing the accuracy of 18F-PSMA-1007 PET/CT and MRI for locoregional staging of prostate cancer, with results of histopathologic examination as the reference standard comparator. Radiologists, nuclear medicine physicians, and pathologists were blinded to preoperative clinical, pathology, and imaging data. Patients underwent all imaging studies and radical prostatectomies at 2 tertiary care hospitals in Alberta, Canada. Eligible participants included men with intermediate-risk or high-risk prostate cancer who consented to radical prostatectomy. Participants who underwent radical prostatectomy were included in the final analysis. Patients were recruited between March 2022 and June 2023, and data analysis occurred between July 2023 and December 2023. Exposures: All participants underwent both 18F-PSMA-1007 PET/CT and MRI within 2 weeks of one another and before radical prostatectomy. Main Outcomes and Measures: The primary outcome was the correct identification of the prostate cancer tumor stage by each imaging test. The secondary outcomes were correct identification of the dominant nodule, laterality, extracapsular extension, and seminal vesical invasion. Results: Of 150 eligible men with prostate cancer, 134 patients ultimately underwent radical prostatectomy (mean [SD] age at prostatectomy, 62.0 [5.7] years). PSMA PET was superior to MRI for the accurate identification of the final pathological tumor stage (61 [45%] vs 38 [28%]; P = .003). PSMA PET was also superior to MRI for the correct identification of the dominant nodule (126 [94%] vs 112 [83%]; P = .01), laterality (86 [64%] vs 60 [44%]; P = .001), and extracapsular extension (100 [75%] vs 84 [63%]; P = .01), but not for seminal vesicle invasion (122 [91%] vs 115 [85%]; P = .07). Conclusions and Relevance: In this phase 2 prospective validating paired cohort study, 18F-PSMA-1007 PET/CT was superior to MRI for the locoregional staging of prostate cancer. These findings support PSMA PET in the preoperative workflow of intermediate-risk and high-risk tumors.

12.
PLoS One ; 19(7): e0307848, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39038023

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0273945.].

13.
PLoS One ; 19(7): e0305300, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39052659

RESUMO

IMPORTANCE: The COVID-19 pandemic has led to 775 million documented cases and over 7 million deaths worldwide as of March 2024 and is an ongoing health crisis. To limit viral spread within households and in the community, public health officials have recommended self-isolation, self-quarantine of exposed household contacts, and mask use. Yet, risk of household transmission (HHT) may be underestimated due to low frequency of sampling, and risk factors for HHT are not well understood. OBJECTIVES: To estimate the secondary attack rate of SARS-CoV-2 within households and to define the risk factors for new infections in household members who are in close contact with the index case. DESIGN, SETTING, AND PARTICIPANTS: In this prospective cohort study, from March 2020-December 2021 we enrolled 60 households with index cases who tested positive for SARS-CoV-2. All household contacts and index cases were tested daily for SARS-CoV-2 via reverse transcription polymerase chain reaction (RT-PCR) using self-collected anterior nares specimens. Households were followed until all study participants in the household tested negative for SARS-CoV-2 for seven consecutive days. We collected sex, age, race/ethnicity, comorbidities, and relationship to index case for secondary contacts, household level characteristics including primary income, household density, and square feet per person on property. We compared the sociodemographic variables between COVID-19 positive and negative household members and between households where secondary transmission did and did not occur. MAIN OUTCOMES AND MEASURES: Daily anterior nares swabs were tested for SARS-CoV-2 using RT-PCR, in order to assess duration of nasal shedding of SARS-CoV-2, as well as risk of transmission to secondary household contacts. RESULTS: Of the 163 participants in this study, 84 (51.5%) were women; median age (IQR) was 36.0 (17.0-54.0) years of age; 78 (47.8%) were white and 48 (29.5%) were Hispanic/LatinX. Of the fifty households with household contacts, at least one secondary case occurred in twenty-six households (52.0%) and forty-five household contacts (43.7%) were infected. Secondary attack rate was lowest among children of index cases (6/23, 26.1%). Modified Poisson regression identified that the risk of transmission to household contacts increases significantly with age (Risk ratio for each increase in years of age = 1.01, 95% CI = 1.00-1.02). Mixed effects regression models identified that participants with chronic diseases, such as asthma, diabetes, cancer, or cardiac disease, had higher Cts at baseline when compared to participants without chronic diseases (6.62, 95% CI: 1.46-11.77, p = 0.02) and show a slower rate of increase in Ct over time (-0.43, 95% CI: -0.77 to -0.09, p = 0.02). CONCLUSIONS AND RELEVANCE: This study suggests that HHT represents a key source of community-based infection of SARS-CoV-2. Allocation of resources for contact investigations and prevention interventions should focus on the individuals at highest risk of infection in households, especially those with higher density homes.


Assuntos
COVID-19 , Características da Família , SARS-CoV-2 , Eliminação de Partículas Virais , Humanos , COVID-19/transmissão , COVID-19/epidemiologia , COVID-19/virologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , SARS-CoV-2/isolamento & purificação , Estudos Prospectivos , Adolescente , Criança , Adulto Jovem , Fatores de Risco , Pré-Escolar , Idoso
14.
Eur Heart J Suppl ; 26(Suppl 3): iii75-iii78, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39055596

RESUMO

The Philippine Society of Hypertension (PSH) took part again in the annual May Measurement Month 2021 (MMM21) blood pressure (BP) campaign to raise awareness of hypertension. The MMM standard protocol designed by the MMM coordinating centre was used during screening. These included the collection of basic data on demography, lifestyle, and environmental factors. Standardized sitting BP measurements were taken three times, using automated BP apparatus and were either entered via MMM21 app, MMM@Home, and Google Forms or recorded on paper and transferred to Excel spreadsheets by PSH encoders. Hypertension was defined either as systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg or on antihypertensive medication. A total of 59 655 participated through opportunistic convenience sampling. After multiple imputation, a total of 26 813 (44.9%) participants were identified as having hypertension. Of these, 14 449 (53.9%) were aware and 12 978 (48.4%) were on antihypertensive medication. Of those who were treated, 5644 (43.5%) had controlled BP (<140/90 mmHg) and 7334 (56.5%) were uncontrolled. These latest local data showed that BP awareness is still low with BP control achieved in less than half of treated patients. Continued collaboration is needed to improve BP screening programmes in the country.

15.
Nature ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048817

RESUMO

Dysregulated transcription due to disruption in histone lysine methylation dynamics is an established contributor to tumorigenesis1,2. However, whether analogous pathologic epigenetic mechanisms act directly on the ribosome to advance oncogenesis is unclear. Here we find that trimethylation of the core ribosomal protein L40 (rpL40) at lysine 22 (rpL40K22me3) by the lysine methyltransferase SMYD5 regulates mRNA translation output to promote malignant progression of gastric adenocarcinoma (GAC) with lethal peritoneal ascites. A biochemical-proteomics strategy identifies the monoubiquitin fusion protein partner rpL40 (ref. 3) as the principal physiological substrate of SMYD5 across diverse samples. Inhibiting the SMYD5-rpL40K22me3 axis in GAC cell lines reprogrammes protein synthesis to attenuate oncogenic gene expression signatures. SMYD5 and rpL40K22me3 are upregulated in samples from patients with GAC and negatively correlate with clinical outcomes. SMYD5 ablation in vivo in familial and sporadic mouse models of malignant GAC blocks metastatic disease, including peritoneal carcinomatosis. Suppressing SMYD5 methylation of rpL40 inhibits human cancer cell and patient-derived GAC xenograft growth and renders them hypersensitive to inhibitors of PI3K and mTOR. Finally, combining SMYD5 depletion with PI3K-mTOR inhibition and chimeric antigen receptor T cell administration cures an otherwise lethal in vivo mouse model of aggressive GAC-derived peritoneal carcinomatosis. Together, our work uncovers a ribosome-based epigenetic mechanism that facilitates the evolution of malignant GAC and proposes SMYD5 targeting as part of a potential combination therapy to treat this cancer.

16.
Am J Public Health ; : e1-e10, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39024534

RESUMO

Objectives. To determine mortality risk among those recently released from a Minnesota jail or prison. Methods. Using linked prison, jail, and death records, our retrospective cohort study followed 99 065 people who were released from Minnesota jails and prisons between March 1, 2020, and December 31, 2021. We explored differences between jail and prison exposures regarding mortality using standardized mortality ratios. Results. Adjusting for age and gender, we estimated that the rate of overdose death for people released from jail was 15.5 times that of the Minnesota general population. Overdose death rates for people released from prison were even higher at 28.3 times the rate of the Minnesota general population. Conclusions. Drug overdose was the leading cause of death for people reentering their communities from both jail and prison in Minnesota-with opioids being the leading cause of overdoses. Overdose death relative to the general population was double the estimates from earlier studies among people leaving prison. Providing seamless access to medications for opioid use disorder during and after incarceration is important to lower the risk of death following release. (Am J Public Health. Published online ahead of print July 18, 2024:e1-e10. https://doi.org/10.2105/AJPH.2024.307723).

17.
Cell Rep Methods ; 4(7): 100815, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38986612

RESUMO

The ability of cells to sense and respond to mechanical forces is critical in many physiological and pathological processes. However, determining the mechanisms by which forces affect protein function inside cells remains challenging. Motivated by in vitro demonstrations of fluorescent proteins (FPs) undergoing reversible mechanical switching of fluorescence, we investigated whether force-sensitive changes in FP function could be visualized in cells. Guided by a computational model of FP mechanical switching, we develop a formalism for its detection in Förster resonance energy transfer (FRET)-based biosensors and demonstrate its occurrence in cellulo within a synthetic actin crosslinker and the mechanical linker protein vinculin. We find that in cellulo mechanical switching is reversible and altered by manipulation of cell force generation, external stiffness, and force-sensitive bond dynamics of the biosensor. This work describes a framework for assessing FP mechanical stability and provides a means of probing force-sensitive protein function inside cells.


Assuntos
Técnicas Biossensoriais , Transferência Ressonante de Energia de Fluorescência , Proteínas Luminescentes , Transferência Ressonante de Energia de Fluorescência/métodos , Proteínas Luminescentes/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/química , Técnicas Biossensoriais/métodos , Humanos , Vinculina/metabolismo , Vinculina/química , Actinas/metabolismo , Actinas/química , Fenômenos Biomecânicos
18.
Adv Cancer Res ; 161: 191-221, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39032950

RESUMO

Prostate cancer, one of the most frequently diagnosed cancers in men, leads to significant mortality worldwide. Its study is important due to the complexity and diversity in its progression, highlighting the urgent need for improved therapeutic strategies. This chapter probes into the genetic and epigenetic factors influencing prostate cancer progression, underscoring the importance of understanding the disease's molecular fundamentals for the development of targeted therapies. It specifically reviews the role of key genetic mutations in genes such as Androgen Receptor, TP53, SPOP, FOXA1 and PTEN which are crucial for the disease onset and a progression. Furthermore, it examines the impact of epigenetic modifications, including DNA methylation and histone modification, which contribute to the cancer's progression by affecting gene expression and cellular behavior. Further, in this chapter we delve into the underlying signaling mechanism, the advancements in targeting genetic and epigenetic alterations in prostate cancer. These findings have revealed promising targets for therapeutic advancements, aiming to understand and identify promising avenues for future therapies. This chapter improves our current understanding of prostate cancer genetic and epigenetic landscape, emphasizing the necessity of advancing our knowledge to refine and expand treatment options for prostate cancer patients.


Assuntos
Epigênese Genética , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Epigênese Genética/genética , Metilação de DNA/genética , Regulação Neoplásica da Expressão Gênica
19.
Adv Mater ; : e2405736, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39036822

RESUMO

Frontal ring-opening metathesis polymerization (FROMP) presents an energy-efficient approach to produce high-performance polymers, typically utilizing norbornene derivatives from Diels-Alder reactions. This study broadens the monomer repertoire for FROMP, incorporating the cycloaddition product of biosourced furan compounds and benzyne, namely 1,4-dihydro-1,4-epoxynaphthalene (HEN) derivatives. A computational screening of Diels-Alder products is conducted, selecting products with resistance to retro-Diels-Alder but also sufficient ring strain to facilitate FROMP. The experiments reveal that varying substituents both modulate the FROMP kinetics and enable the creation of thermoplastic materials characterized by different thermomechanical properties. Moreover, HEN-based crosslinkers are designed to enhance the resulting thermomechanical properties at high temperatures (>200 °C). The versatility of such materials is demonstrated through direct ink writing (DIW) to rapidly produce 3D structures without the need for printed supports. This research significantly extends the range of monomers suitable for FROMP, furthering efficient production of high-performance polymeric materials.

20.
Alcohol ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39033967

RESUMO

Our laboratory has previously shown that chronic ethanol exposure elicits enhanced working memory performance in female, but not male, adult Sprague-Dawley rats, indicative of a fundamental sex difference in cortical plasticity. Recent studies have furthermore revealed that females display markedly reduced HCN-mediated channel activity in inhibitory Martinotti interneurons after chronic ethanol exposure that is similarly not observed in males. From these observations we hypothesized that alcohol elicits facilitated working memory performance via down-regulation of these channels' activity specifically within interneurons. To test this hypothesis, we employed a Pol-II compatible shRNA expression system to elicit targeted knockdown of HCN channel activity in these cells, and measured performance on a delayed Non-Match-to-Sample (NMS) T-maze test to gauge effects on working memory performance. A significant baseline enhancement of working memory performance with HCN channel knockdown was observed, indicative of a critical role for interneuron-expressed HCNs in maintaining optimal cortical network activity during cognitively-demanding tasks. Consistent with previous observations, ethanol exposure resulted in enhanced NMS T-maze performance, however elevated working memory performance was observed in both scram- and hcn-shRNA infected groups after alcohol administration. We therefore conclude that interneuron-expressed HCN channels, despite representing a minor population of total cortical HCN expression, contribute substantially to maintaining working memory processes. Downregulated HCN channel activity, though, does not alone appear sufficient to manifest alcohol-induced enhancement of working memory performance observed in female rats during acute withdrawal.

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