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Sökning: WFRF:(Meehan M) > (2020-2024)

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3.
  • Balliu, Enkeleda, PhD student, et al. (författare)
  • High-efficiency radiation-balanced Yb-doped silica fiber laser with 200-mW output
  • 2024
  • Ingår i: Optics Letters. - : Optica Publishing Group. - 0146-9592 .- 1539-4794. ; 49:8, s. 2021-2024
  • Tidskriftsartikel (refereegranskat)abstract
    • The focus of this study was the development of a second generation of fiber lasers internally cooled by anti-Stokes fluorescence. The laser consisted of a length of a single-mode fiber spliced to fiber Bragg gratings to form the optical resonator. The fiber was single-moded at the pump (1040 nm) and signal (1064 nm) wavelengths. Its core was heavily doped with Yb, in the initial form of CaF2 nanoparticles, and co-doped with Al to reduce quenching and improve the cooling efficiency. After optimizing the fiber length (4.1 m) and output-coupler reflectivity (3.3%), the fiber laser exhibited a threshold of 160 mW, an optical efficiency of 56.8%, and a radiation-balanced output power (no net heat generation) of 192 mW. On all three metrics, this performance is significantly better than the only previously reported radiation-balanced fiber laser, which is even more meaningful given that the small size of the single-mode fiber core (7.8-µm diameter). At the maximum output power (∼2 W), the average fiber temperature was still barely above room temperature (428 mK). This work demonstrates that with anti-Stokes pumping, it is possible to induce significant gain and energy storage in a small-core Yb-doped fiber while keeping the fiber cool. 
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4.
  • Frey, B. N., et al. (författare)
  • Cooling Yb-Doped Silica Fibers and Fiber Lasers with Anti-Stokes Pumping
  • 2023
  • Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. - 9781510659797
  • Konferensbidrag (refereegranskat)abstract
    • Optical cooling in Yb-doped silica fibers using anti-Stokes fluorescence has become a subject of great interest in the fiber laser community. This paper provides an update on the development of silica fibers designed specifically to enhance their cooling properties. This growing list includes a new, nearly single-mode fiber with a borophosphosilicate core that produced –65 mK of cooling with only 260 mW of 1040-nm pump power. The silica compositions that have now been successfully cooled at atmospheric pressure by anti-Stokes fluorescence by our team include aluminosilicate, aluminofluorosilicate, borophosphosilicate, and aluminosilicate doped with one of three different alkali-earth nanoparticles (Ba, Sr, and Ca). By fitting the measured temperature dependence of the cooled fiber on pump power, two key parameters that control the degree of cooling are inferred, namely the critical quenching concentration and the absorptive loss due to impurities. The inferred values compiled for the fibers that cooled indicate that the extracted heat is highest when the Yb concentration is 2 wt.% or more (to maximize heat extraction), the Al concentration is ~0.8 wt.% or greater (to reduce quenching), and the absorptive loss is below approximately 15 dB/km, and ideally below 5 dB/km (to minimize heating due to pump absorption). Only two of the reported fibers, an LaF3-doped and an LuF3-doped nanoparticle fiber, did not cool, because their Yb and Al concentrations were not sufficiently high. This analysis shows that through careful composition control (especially the Al and Yb concentrations) and minimization of the OH contamination, a new generation of Yb-doped silica fibers is emerging with higher Yb concentrations, greater resistance to quenching, and lower residual loss than commercial Yb-doped fibers. They can be expected to have a significant impact not only on optically cooled devices but also on a much broader range of fiber lasers and amplifiers. 
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5.
  • Martinello, K. A., et al. (författare)
  • Hypothermia is not therapeutic in a neonatal piglet model of inflammation-sensitized hypoxia-ischemia
  • 2022
  • Ingår i: Pediatric Research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 91:6, s. 1416-1427
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Perinatal inflammation combined with hypoxia-ischemia (HO exacerbates injury in the developing brain. Therapeutic hypothermia (HT) is standard care for neonatal encephalopathy; however, its benefit in inflammation-sensitized HI (IS-HI) is unknown. METHODS: Twelve newborn piglets received a 2 mu g/kg bolus and 1 mu g/kg/h infusion over 52 h of Escherichia coli lipopolysaccharide (LPS). HI was induced 4 h after LPS bolus. After HI, piglets were randomized to HT (33.5 degrees C 1-25 h after HI, n = 6) or normothermia (NT, n = 6). Amplitude-integrated electroencephalogram (aEEG) was recorded and magnetic resonance spectroscopy (MRS) was acquired at 24 and 48 h. At 48 h, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive brain cell death, microglial activation/proliferation, astrogliosis, and cleaved caspase-3 (CC3) were quantified. Hematology and plasma cytokines were serially measured. RESULTS: Two HT piglets died. aEEG recovery, thalamic and white matter MRS lactate/N-acetylaspartate, and TUNEL-positive cell death were similar between groups. HT increased microglial activation in the caudate, but had no other effect on glial activation/ proliferation. HT reduced CC3 overall. HT suppressed platelet count and attenuated leukocytosis. Cytokine profile was unchanged by HT. CONCLUSIONS: We did not observe protection with HT in this piglet IS-HI model based on aEEG, MRS, and immunohistochemistry. immunosuppressive effects of HT and countering neuroinflammation by LPS may contribute to the observed lack of HT efficacy. Other immunomodulatory strategies may be more effective in IS-HI.
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6.
  • Munshi, Pashna N., et al. (författare)
  • Age no bar : A CIBMTR analysis of elderly patients undergoing autologous hematopoietic cell transplantation for multiple myeloma
  • 2020
  • Ingår i: Cancer. - : WILEY. - 0008-543X .- 1097-0142. ; 126:23, s. 5077-5087
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Upfront autologous hematopoietic stem cell transplantation (AHCT) remains an important therapy in the management of patients with multiple myeloma (MM), a disease of older adults. Methods The authors investigated the outcomes of AHCT in patients with MM who were aged >= 70 years. The Center for International Blood and Marrow Transplant Research (CIBMTR) database registered 15,999 patients with MM in the United States within 12 months of diagnosis during 2013 through 2017; a total of 2092 patients were aged >= 70 years. Nonrecurrence mortality (NRM), disease recurrence and/or progression (relapse; REL), progression-free survival (PFS), and overall survival (OS) were modeled using Cox proportional hazards models with age at transplantation as the main effect. Because of the large sample size, aPvalue <.01 was considered to be statistically significant a priori. Results An increase in AHCT was noted in 2017 (28%) compared with 2013 (15%) among patients aged >= 70 years. Although approximately 82% of patients received melphalan (Mel) at a dose of 200 mg/m(2)overall, 58% of the patients aged >= 70 years received Mel at a dose of 140 mg/m(2). On multivariate analysis, patients aged >= 70 years demonstrated no difference with regard to NRM (hazard ratio [HR] 1.3; 99% confidence interval [99% CI], 1-1.7 [P = .06]), REL (HR, 1.03; 99% CI, 0.9-1.1 [P = 0.6]), PFS (HR, 1.06; 99% CI, 1-1.2 [P = 0.2]), and OS (HR, 1.2; 99% CI, 1-1.4 [P = .02]) compared with the reference group (those aged 60-69 years). In patients aged >= 70 years, Mel administered at a dose of 140 mg/m(2)was found to be associated with worse outcomes compared with Mel administered at a dose of 200 mg/m(2), including day 100 NRM (1% [95% CI, 1%-2%] vs 0% [95% CI, 0%-1%];P = .003]), 2-year PFS (64% [95% CI, 60%-67%] vs 69% [95% CI, 66%-73%];P = .003), and 2-year OS (85% [95% CI, 82%-87%] vs 89% [95% CI, 86%-91%];P = .01]), likely representing frailty. Conclusions The results of the current study demonstrated that AHCT remains an effective consolidation therapy among patients with MM across all age groups.
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7.
  • Pace, Ryan M., et al. (författare)
  • Variation in human milk composition is related to differences in milk and infant fecal microbial communities
  • 2021
  • Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 9:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Previously published data from our group and others demonstrate that human milk oligosaccharide (HMOs), as well as milk and infant fecal microbial profiles, vary by geography. However, little is known about the geographical variation of other milk-borne factors, such as lactose and protein, as well as the associations among these factors and microbial community structures in milk and infant feces. Here, we characterized and contrasted concentrations of milk-borne lactose, protein, and HMOs, and examined their associations with milk and infant fecal microbiomes in samples collected in 11 geographically diverse sites. Although geographical site was strongly associated with milk and infant fecal microbiomes, both sample types assorted into a smaller number of community state types based on shared microbial profiles. Similar to HMOs, concentrations of lactose and protein also varied by geography. Concentrations of HMOs, lactose, and protein were associated with differences in the microbial community structures of milk and infant feces and in the abundance of specific taxa. Taken together, these data suggest that the composition of human milk, even when produced by relatively healthy women, differs based on geographical boundaries and that concentrations of HMOs, lactose, and protein in milk are related to variation in milk and infant fecal microbial communities.
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8.
  • Balliu, Enkeleda, PhD student, et al. (författare)
  • Improved Closed-Loop Slow-Light Temperature Sensor With Millidegree Resolution for Laser Cooling
  • 2023
  • Ingår i: Proceedings - 28th International Conference on Optical Fiber Sensors, OFS 2023. - : Optica Publishing Group.
  • Konferensbidrag (refereegranskat)abstract
    • For applications such as laser cooling of doped fibers, where it is critical to measure accurately the temperature of a cooled fiber that is very close to room temperature, it is paramount to develop a reliable, very short (mm) fiber temperature sensor with millikelvin resolution and very little drift. We report a second generation of a unique slow-light fiber Bragg grating (FBG) temperature sensor that meets these stringent requirements. Experiments and modeling establish that its temperature response depends only on well-known material constants of the silica FBG and the response of the probe laser's wavelength controller. The response is independent of the linewidth of the slow-light resonance, hence different FBGs and/or resonances have the exact same response. Examples of measured cooling in optically pumped Yb-doped fibers show that more reliable thermal contact with the cooled fiber is obtained by wrapping the FBG and the cooled fiber. 
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9.
  • Dhakal, Binod, et al. (författare)
  • Hematopoietic cell transplantation utilization and outcomes for primary plasma cell leukemia in the current era
  • 2020
  • Ingår i: Leukemia. - : SPRINGERNATURE. - 0887-6924 .- 1476-5551. ; 34:12, s. 3338-3347
  • Tidskriftsartikel (refereegranskat)abstract
    • The outcomes of patients with primary plasma cell leukemia (pPCL) after undergoing hematopoietic cell transplantation (HCT) in the novel agent era are unknown. We report outcomes of 348 patients with pPCL receiving autologous (auto-) HCT (n = 277) and allogeneic (allo-) HCT (n = 71) between 2008 and 2015. Median age was 60 years and 56 years for auto- and allo-HCT respectively. For auto-HCT, the 4-year outcomes were: non-relapse mortality (NRM) 7% (4-11%), relapse (REL) 76% (69-82%), progression-free survival (PFS) 17% (13-23%), and overall survival (OS) 28% (22-35%). Karnofsky performance status (KPS) > 90 and >= very good partial response (VGPR) predicted superior OS in multi-variate analysis for auto-HCT. For allo-HCT, the 4-year outcomes were: NRM 12% (5-21%), REL 69% (56-81%), PFS 19% (10-31%), and OS 31% (19-44%). Compared with prior CIBMTR pPCL patients (1995-2006), inferior survival was noted in the current cohort (3-year OS, 39% vs. 38% in allo-HCT, and 62% vs. 35% in auto-HCT) respectively. However, we noted an increased HCT utilization, from 12% (7-21%) in 1995 to 46% (34-64%) in 2009 using SEER data (available till 2009). Despite modern induction translating to higher proportion receiving HCT, the outcomes remain poor in pPCL patients, mainly derived by high relapse rates post-HCT.
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10.
  • Tabor, J. B., et al. (författare)
  • Role of biomarkers and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion: a systematic review
  • 2023
  • Ingår i: British Journal of Sports Medicine. - 0306-3674. ; 57:12
  • Forskningsöversikt (refereegranskat)abstract
    • ObjectiveDetermine the role of fluid-based biomarkers, advanced neuroimaging, genetic testing and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion (SRC). DesignSystematic review. Data sourcesSearches of seven databases from 1 January 2001 through 24 March 2022 using keywords and index terms relevant to concussion, sports and neurobiological recovery. Separate reviews were conducted for studies involving neuroimaging, fluid biomarkers, genetic testing and emerging technologies. A standardised method and data extraction tool was used to document the study design, population, methodology and results. Reviewers also rated the risk of bias and quality of each study. Eligibility criteria for selecting studiesStudies were included if they: (1) were published in English; (2) represented original research; (3) involved human research; (4) pertained only to SRC; (5) included data involving neuroimaging (including electrophysiological testing), fluid biomarkers or genetic testing or other advanced technologies used to assess neurobiological recovery after SRC; (6) had a minimum of one data collection point within 6 months post-SRC; and (7) contained a minimum sample size of 10 participants. ResultsA total of 205 studies met inclusion criteria, including 81 neuroimaging, 50 fluid biomarkers, 5 genetic testing, 73 advanced technologies studies (4 studies overlapped two separate domains). Numerous studies have demonstrated the ability of neuroimaging and fluid-based biomarkers to detect the acute effects of concussion and to track neurobiological recovery after injury. Recent studies have also reported on the diagnostic and prognostic performance of emerging technologies in the assessment of SRC. In sum, the available evidence reinforces the theory that physiological recovery may persist beyond clinical recovery after SRC. The potential role of genetic testing remains unclear based on limited research. ConclusionsAdvanced neuroimaging, fluid-based biomarkers, genetic testing and emerging technologies are valuable research tools for the study of SRC, but there is not sufficient evidence to recommend their use in clinical practice. PROSPERO registration numberCRD42020164558.
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