Infrared absorption spectroscopy enabling direct access to vibrational fingerprints of the molecular structure is a powerful method for functional studies of bio-molecules. Although the intrinsic ...absorption cross-sections of IR active modes of proteins are nearly 10 orders of magnitude larger than the corresponding Raman cross-sections, they are still small compared to that of fluorescencelabel based methods. Here, we developed a new tool based on collective excitation of plasmonic nanoantenna arrays and demonstrated direct detection of vibrational signatures of single protein monolayers. We first tailored the geometry of individual nanoantennas to form resonant structures that match the molecular vibrational modes. The tailored nanoantennas are then arranged in such a way that their in-phase dipolar coupling leads to a collective excitation of the ensemble with strongly enhanced near fields. The combined collective and individual plasmonic responses of the antenna array play a critical role in attaining signal enhancement factors of 10⁴-10⁵. We achieved measurement of the vibrational spectra of proteins at zeptomole levels for the entire array, corresponding to only 145 molecules per antenna. The near-field nature of the plasmonic enhancement of the absorption signals is demonstrated with progressive loading of the nanoantennas with varying protein film thicknesses. Finally, an advanced model based on nonequilibrium Green's function formalism is introduced, which explains the observed Fano-type absorption line-shapes and tuning of the absorption strengths with the antenna resonance.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Exploring the utility of robots in exposure studies Feld-Cook, Elisabeth; Shome, Rahul; Zaleski, Rosemary T ...
Journal of exposure science & environmental epidemiology,
07/2021, Volume:
31, Issue:
4
Journal Article
Peer reviewed
Open access
Obtaining valid, reliable quantitative exposure data can be a significant challenge for industrial hygienists, exposure scientists, and other health science professionals. In this proof-of-concept ...study, a robotic platform was programmed to perform a simple task as a plausible alternative to human subjects in exposure studies for generating exposure data. The use of robots offers several advantages over the use of humans. Research can be completed more efficiently and there is no need to recruit, screen, or train volunteers. In addition, robots can perform tasks repeatedly without getting tired allowing for collection of an unlimited number of measurements using different chemicals to assess exposure impacts from formulation changes and new product development. The use of robots also eliminates concerns with intentional human exposures while removing health research ethics review requirements which are time consuming. In this study, a humanoid robot was programmed to paint drywall, while volatile organic compounds were measured in air for comparison to model estimates. The measured air concentrations generally agreed with more advanced exposure model estimates. These findings suggest that robots have potential as a methodology for generating exposure measurements relevant to human activities, but without using human subjects.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We report on a mid-infrared photothermal spectroscopy system with a near-infrared fiber probe laser and a tunable quantum cascade pump laser. Photothermal spectra of a 6 μm-thick 4-octyl-4
...-cyanobiphenyl liquid crystal sample are measured with a signal-to-baseline contrast above 10
. As both the peak photothermal signal and the corresponding baseline increase linearly with probe power, the signal-to-baseline contrast converges to an asymptotic limit for a given pump power. This limit is independent of the probe power and characterizes the best contrast achievable for the system. This enables sensitive quantitative spectral characterization of linear infrared absorption features directly from photothermal spectroscopy measurements.
Objective To assess the long-term ovarian function and fertility after heterotopic autotransplantion of frozen–thawed ovarian tissue in cancer patients. Design Prospective clinical case series. ...Setting Academic medical center Patient(s) Four young cancer patients who completed cancer treatment. Intervention(s) Cryopreserved ovarian tissue (2000–2002) was thawed and transplanted to the heterotopic site (between the rectus muscle and fascia) between 2002 and 2005. Main Outcome Measure(s) 1 Serial blood tests (FSH, LH, estradiol, progesterone, testosterone) and ultrasound examinations. 2 Oocyte retrieval and in vitro fertilization. Result(s) The hormonal profiles were consistent with the postmenopausal level before transplantation. The return of the ovarian function was evidenced by hormonal profiles between 12 and 20 weeks after transplantation. Three patients underwent a second transplantation, as restored ovarian function lasted only 3 to 5 months. After the second transplantation, long-term ovarian function (lasting for 15–41 months) was established in all three patients. Six oocytes (one GV, four MI, one MII) were retrieved from the grafts. Three MI oocytes were developed to full maturity in vitro. Four MII oocytes were fertilized and developed to the cleavage stage embryos (up to six-cell). Conclusion(s) Autotransplantation of frozen–thawed ovarian tissue to a heterotopic site restored long-term ovarian function (for >40 months), and showed a potential to restore fertility in cancer patients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Unlike the genomes of many mammals that have a single NK-lysin gene, the cattle genome contains a family of four genes, one of which is expressed preferentially in the lung. In this study, we ...compared the expression of the four bovine NK-lysin genes in healthy animals to animals challenged with pathogens known to be associated with bovine respiratory disease (BRD) using transcriptome sequencing (RNA-seq). The expression of several NK-lysins, especially NK2C, was elevated in challenged relative to control animals. The effects of synthetic peptides corresponding to functional region helices 2 and 3 of each gene product were tested on both model membranes and bio-membranes. Circular dichroism spectroscopy indicated that these peptides adopted a more helical secondary structure upon binding to an anionic model membrane and liposome leakage assays suggested that these peptides disrupt membranes. Bacterial killing assays further confirmed the antimicrobial effects of these peptides on BRD-associated bacteria, including both Pasteurella multocida and Mannhemia haemolytica and an ultrastructural examination of NK-lysin-treated P. multocida cells by transmission electron microscopy revealed the lysis of target membranes. These studies demonstrate that the expanded bovine NK-lysin gene family is potentially important in host defense against pathogens involved in bovine respiratory disease.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In a previous study, we have shown that human neural stem cells (hNSCs) transplanted in brain of mouse intracerebral hemorrhage (ICH) stroke model selectively migrate to the ICH lesion and induce ...behavioral recovery. However, low survival rate of grafted hNSCs in the brain precludes long-term therapeutic effect. We hypothesized that hNSCs overexpressing Akt1 transplanted into the lesion site could provide long-term improved survival of hNSCs, and behavioral recovery in mouse ICH model. F3 hNSC was genetically modified with a mouse Akt1 gene using a retroviral vector. F3 hNSCs expressing Akt1 were found to be highly resistant to H(2)O(2)-induced cytotoxicity in vitro. Following transplantation in ICH mouse brain, F3.Akt1 hNSCs induced behavioral improvement and significantly increased cell survival (50-100% increase) at 2 and 8 weeks post-transplantation as compared to parental F3 hNSCs. Brain transplantation of hNSCs overexpressing Akt1 in ICH animals provided functional recovery, and survival and differentiation of grafted hNSCs. These results indicate that the F3.Akt1 human NSCs should be a great value as a cellular source for the cellular therapy in animal models of human neurological disorders including ICH.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Soil Transmitted Helminths (STH) infect over 1.5 billion people globally and are associated with anemia and stunting, resulting in an annual toll of 1.9 million Disability-Adjusted Life Years ...(DALYs). School-based deworming (SBD), via mass drug administration (MDA) campaigns with albendazole or mebendazole, has been recommended by the World Health Organization to reduce levels of morbidity due to STH in endemic areas. DeWorm3 is a cluster-randomized trial, conducted in three study sites in Benin, India, and Malawi, designed to assess the feasibility of interrupting STH transmission with community-wide MDA as a potential strategy to replace SBD. This analysis examines data from the DeWorm3 trial to quantify discrepancies between school-level reporting of SBD and gold standard individual-level survey reporting of SBD.
Population-weighted averages of school-level SBD calculated at the cluster level were compared to aggregated individual-level SBD estimates to produce a Mean Squared Error (MSE) estimate for each study site. In order to estimate individual-level SBD coverage, these MSE values were applied to SBD estimates from the control arm of the DeWorm3 trial, where only school-level reporting of SBD coverage had been collected. In each study site, SBD coverage in the school-level datasets was substantially higher than that obtained from individual-level datasets, indicating possible overestimation of school-level SBD coverage. When applying observed MSE to project expected coverages in the control arm, SBD coverage dropped from 89.1% to 70.5% (p-value < 0.001) in Benin, from 97.7% to 84.5% (p-value < 0.001) in India, and from 41.5% to 37.5% (p-value < 0.001) in Malawi.
These estimates indicate that school-level SBD reporting is likely to significantly overestimate program coverage. These findings suggest that current SBD coverage estimates derived from school-based program data may substantially overestimate true pediatric deworming coverage within targeted communities.
NCT03014167.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
The characteristics of human parainfluenza virus type 4 (hPIV4) infection are not thoroughly understood. We therefore clarified the characteristics of hPIV4 in Korea.
Method
From January ...2013 to December 2017, children admitted with respiratory tract infection at the Department of Pediatrics in Chung‐Ang University Hospital were enrolled in the study. Nasopharyngeal aspirate specimens were obtained from patients and tested for hPIV types by multiplex reverse transcription polymerase chain reaction. We retrospectively reviewed subject medical records, focusing on epidemiological and clinical characteristics.
Results
Of the 12 423 NPA specimens, 8,406 were positive by multiplex reverse transcription polymerase chain reaction for nine respiratory viruses, and 1,018 were positive for one of the four types of hPIV: 1,018 specimens led to the detection of 1,029 hPIVs; 3ss (31.3%) were positive for hPIV1, 120 (11.7%) were positive for hPIV2, 356 (34.6%) were positive for hPIV3, and 231 (22.4%) were positive for hPIV4. Of the hPIV‐positive patients, the mean age was 2.3 years (range, 0.1–12.7 years), 225 (97.4%) had no underlying disease, and 178 (77.1%) had a fever with a duration of 4.1 ± 2.3 days and a peak temperature of 39.0 ± 0.7 ℃. The most common diagnosis in hPIV4 infection was pneumonia (44.2%), followed by bronchiolitis (26.0%) and upper respiratory tract infection (24.3%). Only 2.2% of patients were diagnosed with croup. Although the most prevalent overall type of hPIV was hPIV3, hPIV4 generally caused acute respiratory tract infection in summer and early fall in an irregular annual pattern.
Conclusions
Human parainfluenza virus type 4 is an important common pathogen of respiratory tract infections in pediatric patients in Korea.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We report a novel nonlinear mid-infrared vibrational spectroscopy regime where multiple bifurcations and signal enhancement are observed in the photothermal spectrum of a 6 μm-thick layer of ...4-octyl-4′-cyanobiphenyl (8CB) liquid crystal. For increasing pump power values, the nonlinear evolution of the photothermal spectrum is studied in 8CB samples initially in the crystalline and smectic-A phase and their non-equilibrium transitions are characterized with pump-probe thermal lens spectroscopy. The nonlinear photothermal phenomena can be explained by the nucleation of localized non-equilibrium transitions that leads to the formation of bubbles, which modify the thermal lensing behavior. Analysis of the multiple bifurcations reveals a universal critical exponent for these non-equilibrium dynamics that can be linked to mean field theory. We report for the first time simultaneous measurement of the photothermal signal amplitude and phase behavior in the nonlinear regime. Due to the signal enhancement and spectral narrowing observed, nonlinear photothermal behavior shows promise for improvement in sensitivity and signal contrast in mid-infrared, attractive for sample characterization in the mid-infrared.
Mid-infrared nonlinear photothermal spectroscopy with multiple bifurcations is demonstrated on liquid crystals across multiple phase transitions.
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