We experimentally study the formation of surface patterns in grafted hydrogel films of nanometer-to-micrometer thickness during imbibition-driven swelling followed by evaporation-driven shrinking. Creases are known to form at the hydrogel surface during swelling; the wavelength of the creasing pattern is proportional to the initial thickness of the hydrogel film with a logarithmic correction that depends on microscopic properties of the hydrogel. We find that, although the characteristic wavelength of the pattern is determined during swelling, the surface morphology can be significantly influenced by evaporation-induced shrinking.
View Article and Find Full Text PDFWhen microscopic droplets are placed between fibers held at a fixed angle, the droplets spontaneously move toward the apex of the fibers. The speed of the droplet motion increases both with the angle between the fibers and the distance the droplet spans across the fibers. The speed of these droplets can be described by a simple scaling relationship.
View Article and Find Full Text PDFUnlabelled: Delirium is a heterogeneous and detrimental mental condition often seen in older, hospitalized patients and is currently hard to predict. In this study, we leverage large-scale, real- world data using the electronic health records (EHR) to identify two cohorts comprised of 7,492 UCSF patients and 19,417 UC health system patients (excluding UCSF patients) with an inpatient delirium diagnosis and the same number of propensity score-matched control patients without delirium. We found significant associations between comorbidities or laboratory test values and an inpatient delirium diagnosis which were validated independently.
View Article and Find Full Text PDFBackground: Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak.
View Article and Find Full Text PDFThe association of tuberculosis and type 2 diabetes mellitus has been a recognized re-emerging challenge in management of the convergence of the two epidemics. Though much of the literature has studied this association, there is less knowledge in the field of genetic diversities that might occur in strains infecting tuberculosis patients with and without diabetes. Our study focused on determining the extent of diversity of genotypes of in both these categories of patients.
View Article and Find Full Text PDFObjectives: To compare disease burden in refugee/asylee, non-refugee immigrant, and US-born patients in the largest safety net clinic in San Francisco, California.
Methods: This is a retrospective chart review including 343 refugee/asylee, 450 immigrant, and 202 US-born patients in a San Francisco clinic from January 2014 to December 2017. Using electronic medical records, we compared prevalence of several diseases by immigration status.
Background: Urinary tract infections (UTIs) cause significant disease and economic burden. Uncomplicated UTIs (uUTIs) occur in otherwise healthy individuals without underlying structural abnormalities, with uropathogenic (UPEC) accounting for 80% of cases. With recent transitions in healthcare toward virtual visits, data on multidrug resistance (MDR) (resistant to ≥3 antibiotic classes) by care setting are needed to inform empiric treatment decision making.
View Article and Find Full Text PDFLaryngoscope Investig Otolaryngol
April 2023
Objective: Limited data exists regarding otolaryngological (ENT) disease in refugees and we aim to characterize its prevalence.
Methods: This is a retrospective descriptive chart review of adult US-born, immigrant, and refugee patients receiving care at a primary care clinic between 2014 and 2017. We report the prevalence of ENT disease by immigration status.
Objective: To determine whether inequities in COVID-19 infection and hospitalization differ from those for common medical conditions: influenza, appendicitis, and all-cause hospitalization.
Design: Retrospective study based on electronic health records of three healthcare systems in San Francisco (university, public, and community) examining (1) racial/ethnic distribution in cases and hospitalization among patients with diagnosed COVID-19 (March-August 2020) and patients with diagnosed influenza, diagnosed appendicitis, or all-cause hospitalization (August 2017-March 2020), and (2) sociodemographic predictors of hospitalization among those with diagnosed COVID-19 and influenza.
Results: Patients 18 years or older with diagnosed COVID-19 ( = 3934), diagnosed influenza ( = 5932), diagnosed appendicitis ( = 1235), or all-cause hospitalization ( = 62,707) were included in the study.
Eur Phys J E Soft Matter
March 2023
Freestanding thin polymer films with high molecular weights exhibit an anomalous decrease in the glass-transition temperature with film thickness. Specifically, in such materials, the measured glass-transition temperature evolves in an affine way with the film thickness, with a slope that weakly depends on the molecular weight. De Gennes proposed a sliding mechanism as the hypothetical dominant relaxation process in these systems, where stress kinks could propagate in a reptation-like fashion through so-called bridges, i.
View Article and Find Full Text PDFThe dispersive spreading of microscopic particles in shear flows is influenced both by advection and thermal motion. At the nanoscale, interactions between such particles and their confining boundaries become unavoidable. We address the roles of electrostatic repulsion and absorption on the spatial distribution and dispersion of charged nanoparticles in near-surface shear flows, observed under evanescent illumination.
View Article and Find Full Text PDFObjectives: First, to determine whether using a single-question subjective hearing screen vs gold standard audiometric evaluation is effective for hearing loss screening in refugees and asylees. Second, to understand the clinical pathways for hearing loss diagnosis and treatment.
Study Design: This is a case series with chart review from January 2014 to December 2017.
Different contact regimes between a spherical lens and a periodically patterned substrate are observed, when they are pressed against each other. Top contact occurs when only the highest substrate sections touch the lens, whereas mixed contact implies that both the highest and the lowest substrate sections come into contact with the lens. In this paper, we study how the pattern density of the substrate, along with its physical properties and those of the lens, determine the transition from top contact to mixed contact.
View Article and Find Full Text PDFPolymerization-induced self-assembly (PISA) is exploited to design hydrogen-bonded poly(stearyl methacrylate)-poly(benzyl methacrylate) [PSMA-PBzMA] worm gels in -dodecane. Using a carboxylic acid-based RAFT agent facilitates hydrogen bonding between neighboring worms to produce much stronger physical gels than those prepared using the analogous methyl ester-based RAFT agent. Moreover, tuning the proportion of these two types of end-groups on the PSMA chains enables the storage modulus (') of a 20% w/w worm gel to be tuned from ∼4.
View Article and Find Full Text PDFBackground: Women are more likely to present with genitourinary complaints immediately after exposure to interpersonal violence, but little is known about the long-term effects of violence on women's urologic health, including their susceptibility to bladder pain and infections.
Objective: To determine whether lifetime interpersonal violence exposure and current posttraumatic stress disorder (PTSD) symptoms are associated with the prevalence or severity of painful bladder symptoms and a greater lifetime history of antibiotic-treated urinary tract infections in community-dwelling midlife and older women.
Study Design: We examined the cross-sectional data from a multiethnic cohort of community-dwelling women aged 40 to 80 years enrolled in a northern California integrated healthcare system.
Background: The prevalence of infections caused by extended-spectrum beta-lactamase producing Escherichia coli (ESBL-E. coli) is increasing worldwide, but the setting in which this increase is occurring is not well defined. We compared trends and risk factors for ESBL-E.
View Article and Find Full Text PDFBackground: Urinary tract infection (UTI) accounts for a substantial portion of outpatient visits and antibiotic prescriptions in the United States. Few studies have considered sociodemographic factors including low socioeconomic status (SES)-which may increase residential crowding, inappropriate antibiotic prescribing, or comorbidities-as UTI or multidrug-resistant (MDR) UTI risk factors.
Methods: We used 2015-2017 electronic health record data from 2 California health care systems to assess whether 3 sociodemographic factors-use of Medicaid, use of an interpreter, and census tract-level deprivation-were associated with overall UTI or MDR UTI.
It is nearly impossible to separate two interleaved phonebooks by pulling their spines. The very slight force exerted by the outer sheets of the assembly is amplified as the exponential of the square of the number of sheets, meaning that even a small number of sheets can create a highly resistant system. We present a systematic and detailed study of the influences of the normal external force and the geometrical parameters of the booklets on the assembly strength.
View Article and Find Full Text PDFThe spontaneous migration of droplets on conical fibers is studied experimentally by depositing silicone oil droplets onto conical glass fibers. Their motion is recorded using optical microscopy and analyzed to extract the relevant geometrical parameters of the system. The speed of the droplet can be predicted as a function of geometry and the fluid properties using a simple theoretical model, which balances viscous dissipation against the surface tension driving force.
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