There have been limited data on the risk of onward transmission from individuals with Omicron variant infections who return to work after a 5-day isolation.
To evaluate the risk of transmission from ...healthcare workers (HCWs) with Omicron variant who returned to work after a 5-day isolation and the viable-virus shedding kinetics.
This investigation was performed in a tertiary care hospital, Seoul, South Korea. In a secondary transmission study, we retrospectively reviewed the data of HCWs confirmed as COVID-19 from March 14th to April 3rd, 2022 in units with five or more COVID-19-infected HCWs per week. In the viral shedding kinetics study, HCWs with Omicron variant infection who agreed with daily saliva sampling were enrolled between February and March, 2022.
Of the 248 HCWs who were diagnosed with COVID-19 within 5 days of the return of an infected HCW, 18 (7%) had contact with the returned HCW within 1–5 days after their return. Of these, nine (4%) had an epidemiologic link other than with the returning HCW, and nine (4%) had contact with the returning HCW, without any other epidemiologic link. In the study of the kinetics of virus shedding (N = 32), the median time from symptom onset to negative conversion of viable virus was four days (95% confidence interval: 3–5).
Our data suggest that the residual risk of virus transmission after 5 days of isolation following diagnosis or symptom onset is low.
The ability to isolate and analyze rare circulating tumor cells (CTCs) has the potential to further our understanding of cancer metastasis and enhance the care of cancer patients. In this protocol, ...we describe the procedure for isolating rare CTCs from blood samples by using tumor antigen-independent microfluidic CTC-iChip technology. The CTC-iChip uses deterministic lateral displacement, inertial focusing and magnetophoresis to sort up to 10⁷ cells/s. By using two-stage magnetophoresis and depletion antibodies against leukocytes, we achieve 3.8-log depletion of white blood cells and a 97% yield of rare cells with a sample processing rate of 8 ml of whole blood/h. The CTC-iChip is compatible with standard cytopathological and RNA-based characterization methods. This protocol describes device production, assembly, blood sample preparation, system setup and the CTC isolation process. Sorting 8 ml of blood sample requires 2 h including setup time, and chip production requires 2-5 d.
Supramolecular hydrogels held together by non-covalent interactions such as electrostatics, hydrogen bonding, and hydrophobic forces are among the most promising soft material platforms for modern ...biomedical applications. By virtue of their inherent reversibility and dynamism, they respond well to environmental stimuli and biochemical cues and can dissipate mechanical energy effectively. These important features are well suited for cell culture, tissue engineering, on-demand controlled release of therapeutics, tissue adhesion, and molecular sensing and as artificial gel substitutes in organs (e.g., vitreous humour and synovial fluids), which are not easily achieved by permanently cross-linked covalent hydrogels. Consequently, supramolecular hydrogels have grown in popularity and have witnessed rapid development for biomedical applications in recent years. Through the numerous applications and exciting advances during the last five years discussed in this mini-review, we highlight how the supramolecular interactions enabling gel formation also translates to their bulk material properties and resulting biomedical applications. Owing to their versatility and ease of ‘bottom-up’ engineering from the molecular level, supramolecular hydrogels are poised to offer a wide range of biomedical solutions to modern societal problems, including but not limited to wound healing, development of artificial tissues, cell therapies, and anticancer treatment. Keywords: Physically-crosslinked hydrogels, Hydrophobic interactions, Hydrogen bonding, Ionic interactions, Inclusion complexes
•Micro-pillar testing carried out on CuCrZr with and without irradiation defects.•Intrinsic and extrinsic size effects obvious only in unirradiated CuCrZr.•Size-independent results obtained from ...smaller pillars following irradiation.•DBH and BKS models predict hardening using microstructural length-scales.
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The results of small-scale mechanical tests are convoluted by the so-called size effect, whereby materials appear stronger when the scale of the test is reduced to the order of microns or less. The dimensional range over which this occurs has been shown to be linked to a change in sample microstructure, such as the addition of defects induced by irradiation. To investigate this response, a CuCrZr alloy was subjected to proton irradiation and mechanically tested using micro compression of pillars with a range in size. It was found that irradiation defects dominate over the extrinsic size effect and the sensitivity to differences in precipitate microstructure was also somewhat reduced, suggesting that size-independent results could be obtained from much smaller test volumes in irradiated material compared to their non-irradiated counterparts. Finally, comparison was made between the increase in yield strength predicted by models and the experimentally measured values to establish the key parameters driving the strengthening behaviour.
In Coulomb drag, a current flowing in one conductor can induce a voltage across an adjacent conductor via the Coulomb interaction. The mechanisms yielding drag effects are not always understood, even ...though drag effects are sufficiently general to be seen in many low-dimensional systems. In this Letter, we observe Coulomb drag in a Coulomb-coupled double quantum dot and, through both experimental and theoretical arguments, identify cotunneling as essential to obtaining a correct qualitative understanding of the drag behavior.
The primary steps of photosynthesis rely on the generation, transport, and trapping of excitons in pigment-protein complexes (PPCs). Generically, PPCs possess highly structured vibrational spectra, ...combining many discrete intra-pigment modes and a quasi-continuous of protein modes, with vibrational and electronic couplings of comparable strength. The intricacy of the resulting vibronic dynamics poses significant challenges in establishing a quantitative connection between spectroscopic data and underlying microscopic models. Here we show how to address this challenge using numerically exact simulation methods by considering two model systems, namely the water-soluble chlorophyll-binding protein of cauliflower and the special pair of bacterial reaction centers. We demonstrate that the inclusion of the full multi-mode vibronic dynamics in numerical calculations of linear spectra leads to systematic and quantitatively significant corrections to electronic parameter estimation. These multi-mode vibronic effects are shown to be relevant in the longstanding discussion regarding the origin of long-lived oscillations in multidimensional nonlinear spectra.
Cyclical, high-dose testosterone administration, termed bipolar androgen therapy (BAT), can induce clinical responses and restore sensitivity to androgen signalling inhibition in patients with ...previously treated castration-resistant prostate cancer (PCa) (CRPC). This trial evaluated whether BAT is a safe and effective first-line hormonal therapy for patients with CRPC.
In cohort C of this single-centre, open-label, phase II, multi-cohort trial (RE-sensitizing with Supraphysiologic Testosterone to Overcome REsistance study), 29 patients with CRPC received first-line hormonal therapy with 400 mg of testosterone cypionate intramuscularly every 28 days concurrent with a luteinising hormone-releasing hormone agonist/antagonist. The primary end-point of the study was the PSA50 response rate to BAT treatment.
After treatment with BAT, four of 29 patients (14%; 95% confidence interval CI: 4–32%) experienced a PSA50 response. The median radiographic progression-free survival to BAT was 8.5 months (95% CI: 6.9–15.1) for patients with metastatic CRPC. After progression on BAT, 17 of 18 patients (94%; 95% CI: 73–100%) achieved a PSA50 response and 15 of 18 patients (83%; 95% CI: 59–96) achieved a PSA90 response on abiraterone or enzalutamide. Twelve of 15 patients (80%; 95% CI: 52–96) with metastatic CRPC remain on abiraterone or enzalutamide with a median duration of follow-up of 11.2 months.
As first-line hormonal treatment for CRPC, BAT was well tolerated and resulted in prolonged disease stabilisation. After progression on BAT, patients had favourable responses to second-generation androgen receptor–targeted therapy.
ClinicalTrials.gov NCT02090114
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•Prostate cancer (PCa) adapts to low testosterone by upregulating the androgen receptor (AR).•High AR is a therapeutic vulnerability to bipolar androgen therapy (BAT).•This is a trial of BAT as first-line hormonal therapy for patients with castration-resistant PCa (CRPC).•BAT produced prostate-specific antigen and objective responses in a subset of patients.•BAT appeared to sensitise CRPC to subsequent androgen ablative therapy.
While existing findings have established an increase in procrastination among students in higher education during COVID-19, they do not elucidate how COVID-19 has effected an increase in ...procrastination. Drawing upon previous findings and employing a life history framework, this paper proposed that the increase in procrastination may be attributed to the heightened levels of uncertainty in the pandemic. Additionally, this paper examined life history strategy as the psychological mechanism underlying the relation between uncertainty and procrastination. By collecting data across two school semesters in a university (
N
= 253), we found that uncertainty and procrastination did not differ between the semester where changes were abruptly imposed to stem the spread of COVID-19 and the following semester. Our findings also revealed that uncertainty predicted procrastination, and that life history strategy mediated the relation between uncertainty and procrastination. Specifically, uncertainty was associated with a faster life history strategy, which was positively associated with procrastination. By shedding light on the psychology behind the effect of uncertainty on procrastination, the findings of this paper hold important implications for the design of procrastination interventions for the uncertain climate during the pandemic and “the new normal” post COVID-19.
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