Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 552
Filter
Add more filters

Publication year range
1.
Nucleic Acids Res ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38953168

ABSTRACT

Most DNA double-strand breaks (DSBs) are harmful to genome integrity. However, some forms of DSBs are essential to biological processes, such as meiotic recombination and V(D)J recombination. DSBs are also required for programmed DNA elimination (PDE) in ciliates and nematodes. In nematodes, the DSBs are healed with telomere addition. While telomere addition sites have been well characterized, little is known regarding the DSBs that fragment nematode chromosomes. Here, we used embryos from the human and pig parasitic nematode Ascaris to characterize the DSBs. Using END-seq, we demonstrate that DSBs are introduced before mitosis, followed by extensive end resection. The resection profile is unique for each break site, and the resection generates 3'-overhangs before the addition of neotelomeres. Interestingly, telomere healing occurs much more frequently on retained DSB ends than on eliminated ends. This biased repair of the DSB ends may be due to the sequestration of the eliminated DNA into micronuclei, preventing neotelomere formation at their ends. Additional DNA breaks occur within the eliminated DNA in both Ascaris and Parascaris, ensuring chromosomal breakage and providing a fail-safe mechanism for PDE. Overall, our data indicate that telomere healing of DSBs is specific to the break sites responsible for nematode PDE.

2.
Proc Natl Acad Sci U S A ; 119(38): e2209234119, 2022 09 20.
Article in English | MEDLINE | ID: mdl-36095214

ABSTRACT

The spatial and temporal patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and COVID-19 deaths in the United States are poorly understood. We show that variations in the cumulative reported cases and deaths by county, state, and date exemplify Taylor's law of fluctuation scaling. Specifically, on day 1 of each month from April 2020 through June 2021, each state's variance (across its counties) of cases is nearly proportional to its squared mean of cases. COVID-19 deaths behave similarly. The lower 99% of counts of cases and deaths across all counties are approximately lognormally distributed. Unexpectedly, the largest 1% of counts are approximately Pareto distributed, with a tail index that implies a finite mean and an infinite variance. We explain why the counts across the entire distribution conform to Taylor's law with exponent two using models and mathematics. The finding of infinite variance has practical consequences. Local jurisdictions (counties, states, and countries) that are planning for prevention and care of largely unvaccinated populations should anticipate the rare but extremely high counts of cases and deaths that occur in distributions with infinite variance. Jurisdictions should prepare collaborative responses across boundaries, because extremely high local counts of cases and deaths may vary beyond the resources of any local jurisdiction.


Subject(s)
COVID-19 , COVID-19/mortality , Humans , SARS-CoV-2/isolation & purification , United States/epidemiology
3.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Article in English | MEDLINE | ID: mdl-35131848

ABSTRACT

Across 11 studies involving six countries from four continents (n = 3,285), we extend insights from field investigations in conflict zones to offline and online surveys to show that personal spiritual formidability-the conviction and immaterial resources (values, strengths of beliefs, character) of a person to fight-is positively associated with the will to fight and sacrifice for others. The physical formidability of groups in conflict has long been promoted as the primary factor in human decisions to fight or flee in times of conflict. Here, studies in Spain, Iraq, Lebanon, Palestine, and Morocco reveal that personal spiritual formidability, a construct distinct from religiosity, is more strongly associated with the willingness to fight and make costly self-sacrifices for the group than physical formidability. A follow-on study among cadets of the US Air Force Academy further indicates that this effect is mediated by a stronger loyalty to the group, a finding replicated in a separate study with a European sample. The results demonstrate that personal spiritual formidability is a primary determinant of the will to fight across cultures, and this individual-level factor, propelled by loyal bonds made with others, disposes citizens and combatants to fight at great personal risk.


Subject(s)
Negotiating/psychology , Social Perception/psychology , Adolescent , Adult , Aged , Cross-Cultural Comparison , Female , Humans , Male , Middle Aged , Personnel Loyalty , Religion , Surveys and Questionnaires , Young Adult
4.
Proc Natl Acad Sci U S A ; 119(34): e2201541119, 2022 08 23.
Article in English | MEDLINE | ID: mdl-35943978

ABSTRACT

Whereas pathogen-specific T and B cells are a primary focus of interest during infectious disease, we have used COVID-19 to ask whether their emergence comes at a cost of broader B cell and T cell repertoire disruption. We applied a genomic DNA-based approach to concurrently study the immunoglobulin-heavy (IGH) and T cell receptor (TCR) ß and δ chain loci of 95 individuals. Our approach detected anticipated repertoire focusing for the IGH repertoire, including expansions of clusters of related sequences temporally aligned with SARS-CoV-2-specific seroconversion, and enrichment of some shared SARS-CoV-2-associated sequences. No significant age-related or disease severity-related deficiencies were noted for the IGH repertoire. By contrast, whereas focusing occurred at the TCRß and TCRδ loci, including some TCRß sequence-sharing, disruptive repertoire narrowing was almost entirely limited to many patients aged older than 50 y. By temporarily reducing T cell diversity and by risking expansions of nonbeneficial T cells, these traits may constitute an age-related risk factor for COVID-19, including a vulnerability to new variants for which T cells may provide key protection.


Subject(s)
Adaptive Immunity , COVID-19 , Immunoglobulin Heavy Chains , Receptors, Antigen, T-Cell, alpha-beta , Receptors, Antigen, T-Cell , SARS-CoV-2 , Adaptive Immunity/genetics , Aged , B-Lymphocytes/immunology , COVID-19/genetics , COVID-19/immunology , Genetic Loci , Humans , Immunoglobulin Heavy Chains/genetics , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell, alpha-beta/genetics , SARS-CoV-2/immunology , Seroconversion , T-Lymphocytes/immunology
5.
J Infect Dis ; 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39028664

ABSTRACT

Within a multi-state viral genomic surveillance program, we evaluated whether proportions of SARS-CoV-2 infections attributed to the JN.1 variant and to XBB-lineage variants (including HV.1 and EG.5) differed between inpatient and outpatient care settings during periods of cocirculation. Both JN.1 and HV.1 were less likely than EG.5 to account for infections among inpatients versus outpatients (aOR=0.60 [95% CI: 0.43-0.84; p=0.003] and aOR=0.35 [95% CI: 0.21-0.58; p<0.001], respectively). JN.1 and HV.1 variants may be associated with a lower risk of severe illness. The severity of COVID-19 may have attenuated as predominant circulating SARS-CoV-2 lineages shifted from EG.5 to HV.1 to JN.1.

6.
Biochem Soc Trans ; 52(3): 1045-1059, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38778769

ABSTRACT

Major advancements in human pluripotent stem cell (hPSC) technology over recent years have yielded valuable tools for cardiovascular research. Multi-cell type 3-dimensional (3D) cardiac models in particular, are providing complementary approaches to animal studies that are better representatives than simple 2-dimensional (2D) cultures of differentiated hPSCs. These human 3D cardiac models can be broadly divided into two categories; namely those generated through aggregating pre-differentiated cells and those that form self-organizing structures during their in vitro differentiation from hPSCs. These models can either replicate aspects of cardiac development or enable the examination of interactions among constituent cell types, with some of these models showing increased maturity compared with 2D systems. Both groups have already emerged as physiologically relevant pre-clinical platforms for studying heart disease mechanisms, exhibiting key functional attributes of the human heart. In this review, we describe the different cardiac organoid models derived from hPSCs, their generation methods, applications in cardiovascular disease research and use in drug screening. We also address their current limitations and challenges as pre-clinical testing platforms and propose potential improvements to enhance their efficacy in cardiac drug discovery.


Subject(s)
Pluripotent Stem Cells , Humans , Pluripotent Stem Cells/cytology , Cell Differentiation , Organoids/cytology , Animals , Heart/physiology , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , Drug Evaluation, Preclinical/methods , Cardiovascular Diseases/metabolism , Models, Cardiovascular
7.
Cytotherapy ; 2024 Apr 14.
Article in English | MEDLINE | ID: mdl-38703154

ABSTRACT

One of the challenges in Good Manufacturing Practice (GMP)-compliant human induced pluripotent stem cell (hiPSC) production is the validation of quality control (QC) tests specific for hiPSCs, which are required for GMP batch release. This study presents a comprehensive description of the validation process for hiPSC-specific GMP-compliant QC assays; more specifically, the validation of assays to assess the potential presence of residual episomal vectors (REVs), the expression of markers of the undifferentiated state and the directed differentiation potential of hiPSCs. Critical aspects and specific acceptance criteria were formulated in a validation plan prior to assay validation. Assay specificity, sensitivity and reproducibility were tested, and the equipment used for each assay was subjected to performance qualification. A minimum input of 20 000 cells (120 ng of genomic DNA) was defined for accurate determination of the presence of REVs. Furthermore, since vector loss in hiPSC lines is a passage-dependent process, we advocate screening for REVs between passages eight and 10, as testing at earlier passages might lead to unnecessary rejection of hiPSC lines. The cutoff value for assessment of markers of the undifferentiated state was set to the expression of at least three individual markers on at least 75% of the cells. When multi-color flow cytometry panels are used, a fluorescence minus one control is advised to ensure the control for fluorescent spread. For the assay to assess the directed differentiation potential, the detection limit was set to two of three positive lineage-specific markers for each of the three individual germ layers. All of our assays proved to be reproducible and specific. Our data demonstrate that our implemented analytical procedures are suitable as QC assays for the batch release of GMP-compliant hiPSCs.

8.
Phytopathology ; 114(7): 1657-1663, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38427606

ABSTRACT

This study provides the first report of a quantitative trait locus (QTL) in maize (Zea mays) for resistance to the southern root-knot nematode (SRKN) (Meloidogyne incognita). The SRKN can feed on the roots of maize in the U.S. Southern Coastal Plain region and can cause yield losses of 30% or more in heavily infested fields. Increases in SRKN density in the soil may reduce the yield for subsequently planted susceptible crops. The use of maize hybrids with resistance to SRKN could prevent an increase in SRKN density, yet no genetic regions have been identified that confer host resistance. In this study, a B73 (susceptible) × Ky21 (resistant) S5 recombinant inbred line (RIL) population was phenotyped for total number of eggs (TE) and root weight. This population had been genotyped using single-nucleotide polymorphisms (SNPs). By utilizing the SNP data with the phenotype data, a single QTL was identified on chromosome 5 that explained 15% of the phenotypic variation (PV) for the number of eggs and 11% of the PV for the number of eggs per gram of root (EGR). Plants that were homozygous for the Ky21 allele for the most associated marker PZA03172.3 had fewer eggs and fewer EGR than the plants that were homozygous or heterozygous for the B73 allele. Thus, the first QTL for SRKN resistance in maize has been identified and could be incorporated into maize hybrids.


Subject(s)
Chromosomes, Plant , Disease Resistance , Phenotype , Plant Diseases , Plant Roots , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Tylenchoidea , Zea mays , Zea mays/genetics , Zea mays/parasitology , Quantitative Trait Loci/genetics , Animals , Tylenchoidea/physiology , Plant Roots/parasitology , Plant Roots/genetics , Plant Diseases/parasitology , Plant Diseases/immunology , Plant Diseases/genetics , Chromosomes, Plant/genetics , Disease Resistance/genetics , Polymorphism, Single Nucleotide/genetics , Genotype , Chromosome Mapping
9.
Facial Plast Surg ; 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38232752

ABSTRACT

The use of doxycycline as a sclerosing agent is well-established. Given the clinical efficacy of doxycycline sclerosant therapy, we embarked upon a study to evaluate the efficacy of small-volume liquified doxycycline particularly in thick skinned rhinoplasty patients to promote re-adhesion of the nasal skin-soft tissue envelope (SSTE) thereby minimizing surgical dead space and enhancing surface contour, to improve the eventual outcome of surgery.We present two clinical case series using rhinodesis. All patients were treated with the same rhinodesis protocol that included conventional splinting and taping. The first series consisted of 102 consecutive primary rhinoplasties with medium to thick nasal skin treated via open rhinoplasty. Doxycycline solution at a concentration of 20 mg/mL was applied beneath the skin flap using a 14-gauge angiocath inserted through small gaps in the marginal suture line following closure, retained for 2 to 3 minutes, and then expressed from the dead space. Firm manual compression of the SSTE was maintained for at least 1 additional minute, and the splint was then applied. The second series consisted of 25 thick-skinned primary rhinoplasties that were also treated with open rhinoplasty using the same rhinodesis protocol. However, the second group was evaluated with serial postoperative ultrasonography to characterize the soft-tissue response to rhinodesis, particularly within the tip and supra-tip regions.Results revealed enhanced skin adherence in nearly all patients when compared to traditional taping and splinting alone. Ultrasonic examination demonstrated enhanced adherence of the subcutaneous tissue to the nasal framework and suggests that rhinodesis is effective at minimizing dead space in majority of thick-skinned rhinoplasty patients. No complications were observed. Doxycycline can be used easily and safely to seal the surgical dead space post-rhinoplasty and minimize degradation of nasal contour with excellent outcome.

10.
Mod Pathol ; 36(6): 100129, 2023 06.
Article in English | MEDLINE | ID: mdl-36931041

ABSTRACT

We examined the performance of deep learning models on the classification of thyroid fine-needle aspiration biopsies using microscope images captured in 2 ways: with a high-resolution scanner and with a mobile phone camera. Our training set consisted of images from 964 whole-slide images captured with a high-resolution scanner. Our test set consisted of 100 slides; 20 manually selected regions of interest (ROIs) from each slide were captured in 2 ways as mentioned above. Applying a baseline machine learning algorithm trained on scanner ROIs resulted in performance deterioration when applied to the smartphone ROIs (97.8% area under the receiver operating characteristic curve [AUC], CI = [95.4%, 100.0%] for scanner images vs 89.5% AUC, CI = [82.3%, 96.6%] for mobile images, P = .019). Preliminary analysis via histogram matching showed that the baseline model was overly sensitive to slight color variations in the images (specifically, to color differences between mobile and scanner images). Adding color augmentation during training reduces this sensitivity and narrows the performance gap between mobile and scanner images (97.6% AUC, CI = [95.0%, 100.0%] for scanner images vs 96.0% AUC, CI = [91.8%, 100.0%] for mobile images, P = .309), with both modalities on par with human pathologist performance (95.6% AUC, CI = [91.6%, 99.5%]) for malignancy prediction (P = .398 for pathologist vs scanner and P = .875 for pathologist vs mobile). For indeterminate cases (pathologist-assigned Bethesda category of 3, 4, or 5), color augmentations confer some improvement (88.3% AUC, CI = [73.7%, 100.0%] for the baseline model vs 96.2% AUC, CI = [90.9%, 100.0%] with color augmentations, P = .158). In addition, we found that our model's performance levels off after 15 ROIs, a promising indication that ROI data collection would not be time-consuming for our diagnostic system. Finally, we showed that the model has sensible Bethesda category (TBS) predictions (increasing risk malignancy rate with predicted TBS category, with 0% malignancy for predicted TBS 2 and 100% malignancy for TBS 6).


Subject(s)
Cytology , Thyroid Neoplasms , Humans , Smartphone , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/pathology , Machine Learning
11.
Stem Cells ; 40(7): 655-668, 2022 07 27.
Article in English | MEDLINE | ID: mdl-35429386

ABSTRACT

Electrical activity and intracellular Ca2+ transients are key features of cardiomyocytes. They can be measured using organic voltage- and Ca2+-sensitive dyes but their photostability and phototoxicity mean they are unsuitable for long-term measurements. Here, we investigated whether genetically encoded voltage and Ca2+ indicators (GEVIs and GECIs) delivered as modified mRNA (modRNA) into human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) would be accurate alternatives allowing measurements over long periods. These indicators were detected in hiPSC-CMs for up to 7 days after transfection and did not affect responses to proarrhythmic compounds. Furthermore, using the GEVI ASAP2f we observed action potential prolongation in long QT syndrome models, while the GECI jRCaMP1b facilitated the repeated evaluation of Ca2+ handling responses for various tyrosine kinase inhibitors. This study demonstrated that modRNAs encoding optogenetic constructs report cardiac physiology in hiPSC-CMs without toxicity or the need for stable integration, illustrating their value as alternatives to organic dyes or other gene delivery methods for expressing transgenes.


Subject(s)
Induced Pluripotent Stem Cells , Action Potentials/physiology , Calcium , Coloring Agents , Humans , Myocytes, Cardiac , Optogenetics , RNA, Messenger/genetics
12.
Article in English | MEDLINE | ID: mdl-37486824

ABSTRACT

Within the 16SrII phytoplasma group, subgroups A-X have been classified based on restriction fragment length polymorphism of their 16S rRNA gene, and two species have been described, namely 'Candidatus Phytoplasma aurantifolia' and 'Ca. Phytoplasma australasia'. Strains of 16SrII phytoplasmas are detected across a broad geographic range within Africa, Asia, Australia, Europe and North and South America. Historically, all members of the 16SrII group share ≥97.5 % nucleotide sequence identity of their 16S rRNA gene. In this study, we used whole genome sequences to identify the species boundaries within the 16SrII group. Whole genome analyses were done using 42 phytoplasma strains classified into seven 16SrII subgroups, five 16SrII taxa without official 16Sr subgroup classifications, and one 16SrXXV-A phytoplasma strain used as an outgroup taxon. Based on phylogenomic analyses as well as whole genome average nucleotide and average amino acid identity (ANI and AAI), eight distinct 16SrII taxa equivalent to species were identified, six of which are novel descriptions. Strains within the same species had ANI and AAI values of >97 %, and shared ≥80 % of their genomic segments based on the ANI analysis. Species also had distinct biological and/or ecological features. A 16SrII subgroup often represented a distinct species, e.g., the 16SrII-B subgroup members. Members classified within the 16SrII-A, 16SrII-D, and 16SrII-V subgroups as well as strains classified as sweet potato little leaf phytoplasmas fulfilled criteria to be included as members of a single species, but with subspecies-level relationships with each other. The 16SrXXV-A taxon was also described as a novel phytoplasma species and, based on criteria used for other bacterial families, provided evidence that it could be classified as a distinct genus from the 16SrII phytoplasmas. As more phytoplasma genome sequences become available, the classification system of these bacteria can be further refined at the genus, species, and subspecies taxonomic ranks.


Subject(s)
Phytoplasma , Humans , Phytoplasma/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Phylogeny , DNA, Bacterial/genetics , Base Composition , Bacterial Typing Techniques , Fatty Acids/chemistry
13.
Europace ; 25(6)2023 06 02.
Article in English | MEDLINE | ID: mdl-37369559

ABSTRACT

AIMS: SCN5A mutations are associated with various cardiac phenotypes, including long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), and cardiac conduction disease (CCD). Certain mutations, such as SCN5A-1795insD, lead to an overlap syndrome, with patients exhibiting both features of BrS/CCD [decreased sodium current (INa)] and LQT3 (increased late INa). The sodium channel blocker mexiletine may acutely decrease LQT3-associated late INa and chronically increase peak INa associated with SCN5A loss-of-function mutations. However, most studies have so far employed heterologous expression systems and high mexiletine concentrations. We here investigated the effects of a therapeutic dose of mexiletine on the mixed phenotype associated with the SCN5A-1795insD mutation in HEK293A cells and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS AND RESULTS: To assess only the chronic effects on trafficking, HEK293A cells transfected with wild-type (WT) SCN5A or SCN5A-1795insD were incubated for 48 h with 10 µm mexiletine followed by wash-out, which resulted in an increased peak INa for both SCN5A-WT and SCN5A-1795insD and an increased late INa for SCN5A-1795insD. Acute re-exposure of HEK293A cells to 10 µm mexiletine did not impact on peak INa but significantly decreased SCN5A-1795insD late INa. Chronic incubation of SCN5A-1795insD hiPSC-CMs with mexiletine followed by wash-out increased peak INa, action potential (AP) upstroke velocity, and AP duration. Acute re-exposure did not impact on peak INa or AP upstroke velocity, but significantly decreased AP duration. CONCLUSION: These findings demonstrate for the first time the therapeutic benefit of mexiletine in a human cardiomyocyte model of SCN5A overlap syndrome.


Subject(s)
Brugada Syndrome , Long QT Syndrome , Humans , Mexiletine/pharmacology , Cardiac Conduction System Disease , NAV1.5 Voltage-Gated Sodium Channel/genetics , NAV1.5 Voltage-Gated Sodium Channel/metabolism , Brugada Syndrome/genetics , Action Potentials , Myocytes, Cardiac
14.
J Immunol ; 206(8): 1966-1975, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33722878

ABSTRACT

Inflammation has long been associated with cancer initiation and progression; however, how inflammation causes immune suppression in the tumor microenvironment and resistance to immunotherapy is not well understood. In this study, we show that both innate proinflammatory cytokine IL-1α and immunotherapy-induced IL-1α make melanoma resistant to immunotherapy. In a mouse melanoma model, we found that tumor size was inversely correlated with response to immunotherapy. Large tumors had higher levels of IL-1α, Th2 cytokines, polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), and regulatory T cells but lower levels of IL-12, Th1 cytokines, and activated T cells. We found that therapy with adenovirus-encoded CD40L (rAd.CD40L) increased tumor levels of IL-1α and PMN-MDSCs. Blocking the IL-1 signaling pathway significantly decreased rAd.CD40L-induced PMN-MDSCs and their associated PD-L1 expression in the tumor microenvironment and enhanced tumor-specific immunity. Similarly, blocking the IL-1 signaling pathway improved the antimelanoma activity of anti-PD-L1 Ab therapy. Our study suggests that blocking the IL-1α signaling pathway may increase the efficacy of immunotherapies against melanoma.


Subject(s)
Drug Resistance, Neoplasm/immunology , Immune Checkpoint Inhibitors/therapeutic use , Immunotherapy/methods , Interleukin-1alpha/immunology , Melanoma, Experimental/therapy , Animals , Cell Line, Tumor , Cytokines/immunology , Cytokines/metabolism , Humans , Immune Checkpoint Inhibitors/immunology , Interleukin-1alpha/metabolism , Kaplan-Meier Estimate , Melanoma, Experimental/immunology , Mice, Inbred C57BL , Myeloid-Derived Suppressor Cells/immunology , Myeloid-Derived Suppressor Cells/metabolism , Neutrophils/immunology , Neutrophils/metabolism , Signal Transduction/drug effects , Signal Transduction/immunology , Tumor Microenvironment/drug effects , Tumor Microenvironment/immunology
15.
Res Nurs Health ; 46(1): 136-147, 2023 02.
Article in English | MEDLINE | ID: mdl-36504287

ABSTRACT

Brain fog is one symptom that has been underexplored in traumatic brain injury (TBI). We explored the cognitive and affective correlates of brain fog in people with symptomatic mild TBI (n = 15), moderate-to-severe TBI (n = 15), and a healthy control group (n = 16). Measures across the studies assessed "brain fog" (Mental Clutter Scale), objective cognition (Useful Field of View® and Cogstate Brief Battery®), post-concussive symptoms (Post-Concussion Symptom Scale), and depressive symptoms (Profile of Moods Scale). Brain fog was higher in symptomatic mild TBI and moderate-to-severe TBI compared with healthy controls. Greater brain fog corresponded to greater depressive symptoms in symptomatic mild TBI. Greater brain fog corresponded to poorer episodic memory and working memory in moderate-to-severe TBI. Brain fog appears to reflect challenges in recovery, including depressive symptoms and worse cognitive function. Screening for brain fog might be worthwhile in people with brain injuries.


Subject(s)
Brain Concussion , Brain Injuries, Traumatic , Brain Injuries , Humans , Brain Injuries, Traumatic/complications , Brain Concussion/complications , Brain Concussion/diagnosis , Cognition , Brain
16.
J Environ Manage ; 332: 117398, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36738721

ABSTRACT

Capturing CO2 has become increasingly important. However, wide industrial applications of conventional CO2 capture technologies are limited by their slow CO2 sorption and desorption kinetics. Accordingly, this research is designed to overcome the challenge by synthesizing mesoporous MgO nanoparticles (MgO-NPs) with a new method that uses PEG 1500 as a soft template. MgO surface structure is nonstoichiometric due to its distinctive shape; the abundant Lewis base sites provided by oxygen vacancies promote CO2 capture. Adding 2 wt % MgO-NPs to 20 wt % monoethanolamine (MEA) can increase the breakthrough time (the time with 90% CO2 capturing efficiency) by ∼3000% and can increase the CO2 absorption capacity within the breakthrough time by ∼3660%. The data suggest that MgO-NPs can accelerate the rate and increase CO2 desorption capacity by up to ∼8740% and ∼2290% at 90 °C, respectively. Also, the excellent stability of the system within 50 cycles is verified. These findings demonstrate a new strategy to innovate MEA absorbents currently widely used in commercial post-combustion CO2 capture plants.


Subject(s)
Carbon Dioxide , Magnesium Oxide , Carbon Dioxide/chemistry , Magnesium Oxide/chemistry , Lewis Bases , Ethanolamine/chemistry , Kinetics
17.
Cytometry A ; 101(10): 818-834, 2022 10.
Article in English | MEDLINE | ID: mdl-34128311

ABSTRACT

Assays based on Förster resonance energy transfer (FRET) can be used to study many processes in cell biology. Although this is most often done with microscopy for fluorescence detection, we report two ways to measure FRET in living cells by flow cytometry. Using a conventional flow cytometer and the "3-cube method" for intensity-based calculation of FRET efficiency, we measured the enzymatic activity of specific kinases in cells expressing a genetically-encoded reporter. For both AKT and protein kinase A, the method measured kinase activity in time-course, dose-response, and kinetic assays. Using the Cytek Aurora spectral flow cytometer, which applies linear unmixing to emission measured in multiple wavelength ranges, FRET from the same reporters was measured with greater single-cell precision, in real time and in the presence of other fluorophores. Results from gene-knockout studies suggested that spectral flow cytometry might enable the sorting of cells on the basis of FRET. The methods we present provide convenient and flexible options for using FRET with flow cytometry in studies of cell biology.


Subject(s)
Fluorescence Resonance Energy Transfer , Proto-Oncogene Proteins c-akt , Cyclic AMP-Dependent Protein Kinases/metabolism , Flow Cytometry/methods , Fluorescence Resonance Energy Transfer/methods , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism
18.
Arterioscler Thromb Vasc Biol ; 41(1): 220-233, 2021 01.
Article in English | MEDLINE | ID: mdl-33086870

ABSTRACT

OBJECTIVE: Previous studies have shown that deficiency of M-CSF (macrophage colony-stimulating factor; or CSF1 [colony stimulating factor 1]) dramatically reduces atherosclerosis in hyperlipidemic mice. We characterize the underlying mechanism and investigate the relevant sources of CSF1 in lesions. Approach and Results: We quantitatively assessed the effects of CSF1 deficiency on macrophage proliferation and apoptosis in atherosclerotic lesions. Staining of aortic lesions with markers of proliferation, Ki-67 and bromodeoxyuridine, revealed around 40% reduction in CSF1 heterozygous (Csf1+/-) as compared with WT (wild type; Csf1+/+) mice. Similarly, staining with a marker of apoptosis, activated caspase-3, revealed a 3-fold increase in apoptotic cells in Csf1+/- mice. Next, we determined the cellular sources of CSF1 contributing to lesion development. Cell-specific deletions of Csf1 in smooth muscle cells using SM22α-Cre (smooth muscle protein 22-alpha-Cre) reduced lesions by about 40%, and in endothelial cells, deletions with Cdh5-Cre (VE-cadherin-Cre) reduced lesions by about 30%. Macrophage-specific deletion with LysM-Cre (lysozyme M-Cre), on the other hand, did not significantly reduce lesions size. Transplantation of Csf1 null (Csf1-/-) mice bone marrow into Csf1+/+ mice reduced lesions by about 35%, suggesting that CSF1 from hematopoietic cells other than macrophages contributes to atherosclerosis. None of the cell-specific knockouts affected circulating CSF1 levels, and only the smooth muscle cell deletions had any effect on the percentage monocytes in the circulation. Also, Csf1+/- mice did not exhibit significant differences in Ly6Chigh/Ly6Clow monocytes as compared with Csf1+/+. CONCLUSIONS: CSF1 contributes to both macrophage proliferation and survival in lesions. Local CSF1 production by smooth muscle cell and endothelial cell rather than circulating CSF1 is the primary driver of macrophage expansion in atherosclerosis.


Subject(s)
Apoptosis , Atherosclerosis/metabolism , Cell Proliferation , Endothelial Cells/metabolism , Macrophage Colony-Stimulating Factor/metabolism , Macrophages/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Animals , Antigens, CD/genetics , Antigens, CD/metabolism , Aorta/metabolism , Aorta/pathology , Atherosclerosis/genetics , Atherosclerosis/pathology , Atherosclerosis/prevention & control , Cadherins/genetics , Cadherins/metabolism , Disease Models, Animal , Endothelial Cells/pathology , Female , Macrophage Colony-Stimulating Factor/deficiency , Macrophage Colony-Stimulating Factor/genetics , Macrophages/pathology , Male , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Muscle Proteins/genetics , Muscle Proteins/metabolism , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , Receptors, LDL/genetics , Receptors, LDL/metabolism , Signal Transduction
19.
J Fish Biol ; 101(5): 1361-1365, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35906859

ABSTRACT

The authors investigated left-right turning preferences of n = 260 juvenile European sea bass (Dicentrarchus labrax) reared in ambient conditions and ocean acidification (OA) conditions or in ambient conditions but tested in OA water. Groups of 10 individuals were observed alone in a circular tank, and individuals' left and right turning during free-swimming was quantified using trajectory data from the video. The authors showed that near-future OA levels do not affect the number of turns made, or behavioural lateralization (turning preference), in juvenile D. labrax tested in groups.


Subject(s)
Bass , Animals , Swimming , Carbon Dioxide , Hydrogen-Ion Concentration , Seawater
20.
J Environ Manage ; 313: 115026, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35405546

ABSTRACT

Carbon dioxide (CO2) emissions from fossil fuel combustion have been linked to increased average global temperatures, a global challenge for many decades. Mitigating CO2 concentration in the atmosphere is a priority for the protection of the environment. This is a comparison of the three main technological categories available for CO2 capture and storage. They include: oxy-fuel combustion, pre-combustion, and post-combustion. Each capture technology has inherent benefits and disadvantages in cost, implementation, and flexibility, but post-combustion CO2 capture has demonstrated the most promising results in typical power plant configurations. This paper presents a review of different post-combustion CO2 capture materials; solvents, membranes, and adsorbents, focusing on economical and environmentally safe low to high temperature solid adsorbents. Furthermore, the authors summarize the advantages and limitations of the materials investigated to provide insight into the challenges and opportunities currently facing the development of post-combustion CO2 capture technologies. The solid sorbents currently available for CO2 capture are also reviewed in detail, including physical and chemical properties, reactions, and current research efforts on improvement.


Subject(s)
Carbon Dioxide , Fossil Fuels , Adsorption , Carbon Dioxide/analysis , Power Plants , Temperature
SELECTION OF CITATIONS
SEARCH DETAIL