Dichotomous dynamics of magnetic monopole fluids.

A recent advance in the study of emergent magnetic monopoles was the discovery that monopole motion is restricted to dynamical fractal trajectories [J. N. Hallén et al., Science 378, 1218 (2022)], thus explaining the characteristics of magnetic monopole noise spectra [R. Dusad et al., Nature 571, 234 (2019); A. M. Samarakoon et al., Proc. Natl. Acad. Sci. U.S.A. 119, e2117453119 (2022)]. Here, we apply this novel theory to explore the dynamics of field-driven monopole currents, finding them composed of two quite distinct transport processes: initially swift fractal rearrangements of local monopole configurations followed by conventional monopole diffusion. This theory also predicts a characteristic frequency dependence of the dissipative loss angle for AC field-driven currents. To explore these novel perspectives on monopole transport, we introduce simultaneous monopole current control and measurement techniques using SQUID-based monopole current sensors. For the canonical material Dy2Ti2O7, we measure [Formula: see text], the time dependence of magnetic flux threading the sample when a net monopole current [Formula: see text] is generated by applying an external magnetic field [Formula: see text] These experiments find a sharp dichotomy of monopole currents, separated by their distinct relaxation time constants before and after t ~[Formula: see text] from monopole current initiation. Application of sinusoidal magnetic fields [Formula: see text] generates oscillating monopole currents whose loss angle [Formula: see text] exhibits a characteristic transition at frequency [Formula: see text] over the same temperature range. Finally, the magnetic noise power is also dichotomic, diminishing sharply after t ~[Formula: see text]. This complex phenomenology represents an unprecedented form of dynamical heterogeneity generated by the interplay of fractionalization and local spin configurational symmetry.

Structural correlates of survival in progressive supranuclear palsy.

INTRODUCTION: Many studies of the Richardson's syndrome phenotype of progressive supranuclear palsy (PSP) have elucidated regions of progressive atrophy and neural correlates of clinical severity. However, the neural correlates of survival and how these differ according to variant phenotypes are poorly understood. We set out to identify structural changes that predict severity and survival from scanning date to death. METHODS: Structural magnetic resonance imaging data from 112 deceased people with clinically defined 'probable' or 'possible' PSP were analysed. Neuroanatomical regions of interest volumes, thickness and area were correlated with 'temporal stage', defined as the ratio of time from symptom onset to death, time from scan to death ('survival from scan'), and in a subset of patients, clinical severity, adjusting for age and total intracranial volume. Forty-nine participants had post mortem confirmation of the diagnosis. RESULTS: Using T1-weighted magnetic resonance imaging, we confirmed the midbrain, and bilateral cortical structural correlates of contemporary disease severity. Atrophy of the striatum, cerebellum and frontotemporal cortex correlate with temporal stage and survival from scan, even after adjusting for severity. Subcortical structure-survival relationships were stronger in Richardson's syndrome than variant phenotypes. CONCLUSIONS: Although the duration of PSP varies widely between people, an individual's progress from disease onset to death (their temporal stage) reflects atrophy in striatal, cerebellar and frontotemporal cortical regions. Our findings suggest magnetic resonance imaging may contribute to prognostication and stratification of patients with heterogenous clinical trajectories and clarify the processes that confer mortality risk in PSP.

Cross-protection and cross-feeding between Klebsiella pneumoniae and Acinetobacter baumannii promotes their co-existence.

Acinetobacter baumannii and Klebsiella pneumoniae are opportunistic pathogens frequently co-isolated from polymicrobial infections. The infections where these pathogens co-exist can be more severe and recalcitrant to therapy than infections caused by either species alone, however there is a lack of knowledge on their potential synergistic interactions. In this study we characterise the genomes of A. baumannii and K. pneumoniae strains co-isolated from a single human lung infection. We examine various aspects of their interactions through transcriptomic, phenomic and phenotypic assays that form a basis for understanding their effects on antimicrobial resistance and virulence during co-infection. Using co-culturing and analyses of secreted metabolites, we discover the ability of K. pneumoniae to cross-feed A. baumannii by-products of sugar fermentation. Minimum inhibitory concentration testing of mono- and co-cultures reveals the ability for A. baumannii to cross-protect K. pneumoniae against the cephalosporin, cefotaxime. Our study demonstrates distinct syntrophic interactions occur between A. baumannii and K. pneumoniae, helping to elucidate the basis for their co-existence in polymicrobial infections.

Hospitalisations of children and adults with Hypoplastic Left Heart Syndrome in Texas from 2009 to 2019.

INTRODUCTION: Hypoplastic Left Heart Syndrome accounts for a significant proportion of CHD morbidity and mortality, despite improvements in care and improved survival. This study evaluates number of, reasons for, and trends in discharges of patients with hypoplastic left heart syndrome over 11 years in Texas. METHODS: The Texas Inpatient Discharge Dataset Public Use File captures almost all discharges in Texas and was reviewed from 2009 to 2019. Discharges of patients ≥5 years of age and diagnosis codes for Hypoplastic Left Heart Syndrome were included. The admitting and principle diagnoses were categorised and all discharges were evaluated for procedures performed. Descriptive and univariate statistical analyses were performed. RESULTS: A total of 1024 discharges were identified with a 16.9% annual increase over the study period. Median length of stay was 4 [IQR: 2-8] and there were 17 (1.7%) in-hospital mortalities with no differences across age groups. Seven (17.1%) discharges of patients 25+ years were uninsured, higher than other age groups (p < 0.001). The most common admitting diagnosis was CHD and 224 (21.9%) of discharges included a procedure, including 23 heart transplants. Discharges occurred from 67 different hospitals with 4 (6.0%) representing 71.4% of all discharges. CONCLUSIONS: Discharges of Hypoplastic Left Heart Syndrome have increased rapidly, particularly in the older age groups and were spread over a large number of hospitals. Further work is needed to understand the interplay between Hypoplastic Left Heart Syndrome and other conditions and care experiences that occur within the general population, which will become more common as this population ages and grows.

Defects in DNA double-strand break repair resensitize antibiotic-resistant Escherichia coli to multiple bactericidal antibiotics.

Antibiotic resistance is becoming increasingly prevalent amongst bacterial pathogens and there is an urgent need to develop new types of antibiotics with novel modes of action. One promising strategy is to develop resistance-breaker compounds, which inhibit resistance mechanisms and thus resensitize bacteria to existing antibiotics. In the current study, we identify bacterial DNA double-strand break repair as a promising target for the development of resistance-breaking co-therapies. We examined genetic variants of Escherichia coli that combined antibiotic-resistance determinants with DNA repair defects. We observed that defects in the double-strand break repair pathway led to significant resensitization toward five bactericidal antibiotics representing different functional classes. Effects ranged from partial to full resensitization. For ciprofloxacin and nitrofurantoin, sensitization manifested as a reduction in the minimum inhibitory concentration. For kanamycin and trimethoprim, sensitivity manifested through increased rates of killing at high antibiotic concentrations. For ampicillin, repair defects dramatically reduced antibiotic tolerance. Ciprofloxacin, nitrofurantoin, and trimethoprim induce the promutagenic SOS response. Disruption of double-strand break repair strongly dampened the induction of SOS by these antibiotics. Our findings suggest that if break-repair inhibitors can be developed they could resensitize antibiotic-resistant bacteria to multiple classes of existing antibiotics and may suppress the development of de novo antibiotic-resistance mutations.

You can't be what you can't see: A systematic website review of Geriatrics Online-Visibility at US medical schools.

BACKGROUND: Graduating US medical students must build strong skills in caring for older adults, necessitated by shifting population demographics. Little is known, however, about current medical student exposure to geriatrics on a national scale. This systematic website review characterizes geriatrics opportunities at US medical schools, seen through the lens of publicly available information online. METHODS: Reviewers searched for 18 online Geriatrics Elements, in the domains of Information Prevalence, Geriatrics Environment, and Geriatrics Education, for all 191 US medical schools accredited as of January 2020. Latent Class Analysis was used to classify schools according to their publicly visible geriatrics opportunities. RESULTS: Schools had a median of 7 Geriatrics Elements identified online [IQR 4-10]. Optional geriatrics clinical activity was the most prevalent (76%), while fewer than half of all schools had online evidence of required geriatrics clinical activity (45%). A profile of the three groups of schools identified by Latent Class Analysis, termed Geriatrics Online-Visibility groups (High n = 39, 20%; Medium n = 90, 47%; Low n = 62, 32%), is presented. Online evidence of geriatrics-specific funding was the greatest distinguishing factor among the groups. CONCLUSIONS: Examining US medical school websites collectively and comparatively across Geriatrics Online-Visibility groups can ground discussions of geriatrics education in current national data. Though many school websites present optional geriatrics activities, far fewer specify geriatrics requirements. High Geriatrics Online-Visibility schools present an array of both optional and required geriatrics opportunities on their websites, but this cohort comprises only 20% of schools. Recommended next steps are proposed to guide schools inspired to enhance their Geriatrics Online-Visibility.

Inhibitors of bacterial RNA polymerase transcription complex.

A series of hybrid compounds that incorporated anthranilic acid with activated 1H-indoles through a glyoxylamide linker were designed to target bacterial RNA polymerase holoenzyme formation using computational docking. Synthesis, in vitro transcription inhibition assays, and biological testing of the hybrids identified a range of potent anti-transcription inhibitors with activity against a range of pathogenic bacteria with MICs as low as 3.1 µM. A structure activity relationship study identified the key structural components necessary for inhibition of both bacterial growth and transcription. Correlation of in vitro transcription inhibition activity with in vivo mechanism of action was established using fluorescence microscopy and resistance passaging using Gram-positive bacteria showed no resistance development over 30 days. Furthermore, no toxicity was observed from the compounds in a wax moth larvae model, establishing a platform for the development of a series of new antibacterial drugs with an established mode of action.

Delving into defence: identifying the Pseudomonas protegens Pf-5 gene suite involved in defence against secreted products of fungal, oomycete and bacterial rhizosphere competitors.

Competitive behaviours of plant growth promoting rhizobacteria (PGPR) are integral to their ability to colonize and persist on plant roots and outcompete phytopathogenic fungi, oomycetes and bacteria. PGPR engage in a range of antagonistic behaviours that have been studied in detail, such as the production and secretion of compounds inhibitory to other microbes. In contrast, their defensive activities that enable them to tolerate exposure to inhibitory compounds produced by their neighbours are less well understood. In this study, the genes involved in the Pseudomonas protegens Pf-5 response to metabolites from eight diverse rhizosphere competitor organisms, Fusarium oxysporum, Rhizoctonia solani, Gaeumannomyces graminis var. tritici, Pythium spinosum, Bacillus subtilis QST713, Pseudomonas sp. Q2-87, Streptomyces griseus and Streptomyces bikiniensis subspecies bikiniensi, were examined. Proximity induced excreted metabolite responses were confirmed for Pf-5 with all partner organisms through HPLC before culturing a dense Pf-5 transposon mutant library adjacent to each of these microbes. This was followed by transposon-directed insertion site sequencing (TraDIS), which identified genes that influence Pf-5 fitness during these competitive interactions. A set of 148 genes was identified that were associated with increased fitness during competition, including cell surface modification, electron transport, nucleotide metabolism, as well as regulatory genes. In addition, 51 genes were identified for which loss of function resulted in fitness gains during competition. These included genes involved in flagella biosynthesis and cell division. Considerable overlap was observed in the set of genes observed to provide a fitness benefit during competition with all eight test organisms, indicating commonalities in the competitive response to phylogenetically diverse micro-organisms and providing new insight into competitive processes likely to take place in the rhizosphere.

Molecular basis for RNA polymerase-dependent transcription complex recycling by the helicase-like motor protein HelD.

In bacteria, transcription complexes stalled on DNA represent a major source of roadblocks for the DNA replication machinery that must be removed in order to prevent damaging collisions. Gram-positive bacteria contain a transcription factor HelD that is able to remove and recycle stalled complexes, but it was not known how it performed this function. Here, using single particle cryo-electron microscopy, we have determined the structures of Bacillus subtilis RNA polymerase (RNAP) elongation and HelD complexes, enabling analysis of the conformational changes that occur in RNAP driven by HelD interaction. HelD has a 2-armed structure which penetrates deep into the primary and secondary channels of RNA polymerase. One arm removes nucleic acids from the active site, and the other induces a large conformational change in the primary channel leading to removal and recycling of the stalled polymerase, representing a novel mechanism for recycling transcription complexes in bacteria.

Access to Care for Older Adults: An Insurmountable Flight of Stairs?

Inability to climb stairs safely can lead older adults to miss desired medical appointments. To facilitate adequate access to routine medical care for older adults, affordable transportation assistance up and down stairs should be available. J Am Geriatr Soc 67:663-664, 2019.

Use of Genome Engineering to Create Patient Specific MLL Translocations in Primary Human Hematopoietic Stem and Progenitor Cells.

One of the challenging questions in cancer biology is how a normal cell transforms into a cancer cell. There is strong evidence that specific chromosomal translocations are a key element in this transformation process. Our studies focus on understanding the developmental mechanism by which a normal stem or progenitor cell transforms into leukemia. Here we used engineered nucleases to induce simultaneous specific double strand breaks in the MLL gene and two different known translocation partners (AF4 and AF9), which resulted in specific chromosomal translocations in K562 cells as well as primary hematopoietic stem and progenitor cells (HSPCs). The initiation of a specific MLL translocation in a small number of HSPCs likely mimics the leukemia-initiating event that occurs in patients. In our studies, the creation of specific MLL translocations in CD34+ cells was not sufficient to transform cells in vitro. Rather, a variety of fates was observed for translocation positive cells including cell loss over time, a transient proliferative advantage followed by loss of the clone, or a persistent proliferative advantage. These studies highlight the application of genome engineering tools in primary human HSPCs to induce and prospectively study the consequences of initiating translocation events in leukemia pathogenesis.

Adapalene gel, 0.1%, as maintenance therapy for acne vulgaris: a randomized, controlled, investigator-blind follow-up of a recent combination study.

OBJECTIVE: To assess the maintenance effect of adapalene gel, 0.1%, relative to gel vehicle in subjects successfully treated in a previous 12-week study of adapalene-doxycycline, 100 mg, combination therapy. DESIGN: Multicenter, investigator-blind, randomized, controlled study. SETTING: Thirty-four US centers. SUBJECTS: A total of 253 subjects with severe acne vulgaris who showed at least moderate improvement from baseline (50% improvement from baseline) when treated with either adapalene plus doxycycline or doxycycline plus gel vehicle in a previous 12-week study. INTERVENTIONS: Subjects were randomized to receive adapalene gel, 0.1%, or gel vehicle once daily for 16 weeks. MAIN OUTCOME MEASURES: Efficacy and safety criteria included maintenance rate (subjects maintaining at least 50% improvement in lesion counts from previous therapy), lesion counts (total, inflammatory, and noninflammatory), global severity assessment, cutaneous tolerability, and adverse events. RESULTS: Adapalene maintenance therapy resulted in significantly larger maintenance rates (75% vs 54%; P<.001) and significantly lower lesion counts (total [P = .005], inflammatory [P = .01], and noninflammatory [P = .02]) compared with gel vehicle. Adapalene was safe and well tolerated in this study. Conclusion This study demonstrates a clinical benefit of continued treatment with adapalene gel, 0.1%, as a maintenance therapy for acne.

Volume-targeted ventilation and arterial carbon dioxide in neonates.

OBJECTIVES: To review the arterial carbon dioxide tensions (PaCO(2)) in newborn infants ventilated using synchronized intermittent mandatory ventilation (SIMV) in volume guarantee mode (using the Dräger Babylog 8000+) with a unit policy targeting tidal volumes of approximately 4 mL/kg. METHODS: Data on ventilator settings and arterial PaCO(2) levels were collected on all arterial blood gases (ABG; n = 288) from 50 neonates (<33 weeks gestational age) ventilated using the Dräger Babylog 8000+ ventilator (Dräger Medizintechnik GmbH, Lübeck, Germany) in SIMV plus volume guarantee mode. Data were analysed for all blood gases done on the entire cohort in the first 48 h of life and a subanalysis was done on the first gas for each infant (n = 38) ventilated using volume guarantee from admission to the nursery. The number of ABG showing severe hypocapnoea (PaCO(2) < 25 mmHg) and/or severe hypercapnoea (PaCO(2) > 65 mmHg) were determined. RESULTS: The mean (SD) PaCO(2) during the first 48 h was 46.6 (9.0) mmHg. The mean (SD) PaCO(2) on the first blood gas of those infants commenced on volume guarantee from admission was 45.1 (12.5) mmHg. Severe hypo- or hypercapnoea occurred in 8% of infants at the time of their first blood gas measurement, and in <4% of blood gas measurements in the first 48 h. CONCLUSIONS: Infants ventilated with volume guarantee ventilation targeting approximately 4 mL/kg (range: 2.9-5.1) have acceptable PaCO(2) levels at the first blood gas measurement and during the first 48 h of life; and avoid severe hypo- or hypercapnoea over 90% of the time.

Combination therapy with adapalene gel 0.1% and doxycycline for severe acne vulgaris: a multicenter, investigator-blind, randomized, controlled study.

BACKGROUND: Combination therapy with a topical retinoid and an antibiotic is recognized as a rational and effective approach for the treatment of acne vulgaris. Adapalene, a naphthoic acid derivative with anti-inflammatory and receptor-selective retinoid properties, is safe and well tolerated. While the combination of adapalene with oral or topical antibiotics has been shown to deliver a superior and faster response than an antibiotic alone, the clinical benefits of a combination of adapalene and doxycycline, the most frequently prescribed oral antibiotic for acne in the United States, have yet to be evaluated. OBJECTIVE AND METHODS: In a 12-week study, the efficacy and safety of the combination of adapalene gel 0.1% with doxycycline was compared with doxycycline alone for the treatment of severe acne. Subjects were randomized to receive doxycycline once daily in the morning and either adapalene or vehicle once daily in the evening. RESULTS: At Week 12, the combination adapalene-doxycycline was significantly superior to doxycycline alone for change from baseline in total (p<0.001), inflammatory (p=0.02), and noninflammatory (p<0.001) lesions. Significant differences in total lesions were observed as early as Week 4 (p=0.04). Both treatments were well tolerated, and no serious adverse events were reported. CONCLUSIONS: The study demonstrates that the combination of adapalene and an oral antibiotic provides a superior and faster benefit than antibiotic therapy alone and should be considered at the initiation of treatment.