Resonant scanning is critical to high speed and in vivo imaging in many applications of laser scanning microscopy. However, resonant scanning suffers from well-known image artifacts due to scanner ...jitter, limiting adoption of high-speed imaging technologies. Here, we introduce a real-time, inexpensive and all electrical method to suppress jitter more than an order of magnitude below the diffraction limit that can be applied to most existing microscope systems with no software changes. By phase-locking imaging to the resonant scanner period, we demonstrate an 86% reduction in pixel jitter, a 15% improvement in point spread function with resonant scanning and show that this approach enables two widely used models of resonant scanners to achieve comparable accuracy to galvanometer scanners running two orders of magnitude slower. Finally, we demonstrate the versatility of this method by retrofitting a commercial two photon microscope and show that this approach enables significant quantitative and qualitative improvements in biological imaging.
Significance: Two-photon and confocal microscopy can obtain high frame rates; however, mosaic imaging of large tissue specimens remains time-consuming and inefficient, with higher imaging rates ...leading to a larger fraction of time wasted translating between imaging locations. Strip scanning obtains faster mosaic imaging rates by translating a specimen at constant velocity through a line scanner at the expense of more complex stitching and geometric distortion due to the difficulty of translating at completely constant velocity.
Aim: We aim to develop an approach to mosaic imaging that can obtain higher accuracy and faster imaging rates while reducing computational complexity.
Approach: We introduce an approach based on scanner-synchronous position sampling that enables subwavelength accurate imaging of specimens moving at a nonuniform velocity, eliminating distortion.
Results: We demonstrate that this approach increases mosaic imaging rates while reducing computational complexity, retaining high SNR, and retaining geometric accuracy.
Conclusions: Scanner synchronous strip scanning enables accurate, high-speed mosaic imaging of large specimens by reducing acquisition and processing time.
With recent results demonstrating imaging using low coherence interferometry to detect multiply scattered light, signal attenuation and imaging resolution remains to be an open question. To address ...this, we present detailed modeling results of light propagation in the multiply scattered low-coherence interferometry (ms/LCI) configuration. Analytical and Monte Carlo models are used to assess the theoretical resolution and contrast of the system, and to explore the effect of media anisotropy on imaging parameters. Imaging resolution and depth penetration are found to depend on the fraction of photons scattered into a narrow range of forward scattering angles rather than the overall media anisotropy.
The experimental evidence and characterization of "vibrational resonance" in a bistable vertical cavity laser are reported. The system is driven by two periodic forcings, with frequencies differing ...by several orders and studied in the case of both symmetrical and asymmetrical quasipotentials. The phenomenon shows up in the dynamics of the polarized laser emission as a resonance in the low-frequency response and signal-to-noise ratio, depending on the amplitude of an applied high-frequency modulation. The possibility to use the phenomenon for low-level detection is experimentally demonstrated.
The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m a.s.l.). The detector was in particular sensitive to intermediate mass ...magnetic monopoles, with masses 10
5
GeV <M
M
< 10
12
GeV. From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3×10
-15
cm
-2
s
-1
sr
-1
for downgoing fast intermediate mass monopoles was established at the 90% C.L.
The SLIM experiment at the Chacaltaya high altitude laboratory was sensitive to nuclearites and Q-balls which could be present in the cosmic radiation as possible Dark Matter components. It was ...sensitive also to strangelets, i.e. small lumps of Strange Quark Matter predicted at such altitudes by various phenomenological models. The analysis of 427 m
2
of Nuclear Track Detectors exposed for 4.22 years showed no candidate event. New upper limits on the flux of downgoing nuclearites and Q-balls at the 90% C.L. were established. The null result also restricts models for strangelets propagation through the Earth atmosphere.
The CNGS neutrino beam Giacomelli, G
Journal of physics. Conference series,
06/2008, Letnik:
116, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CERN to Gran Sasso Neutrino beam (CNGS) was commissioned at CERN in early August 2006 and was first sent at low intensity to Gran Sasso on August 17, 2006. The Borexino, LVD and OPERA detectors ...continued the commissioning of their detectors and started taking data with practically no dead time. The CNGS operated smoothly with good quality. In a short time the 3 detectors collected several hundred events with clean time distributions
IMPORTANCE: Nonmelanoma skin cancers (NMSCs) are primarily diagnosed through paraffin section histologic analysis of skin biopsy specimens that requires days to weeks before a formal diagnosis is ...reported. Two-photon fluorescence microscopy (TPFM) has the potential for point-of-care diagnosis of NMSC and other dermatologic conditions, which could enable same-visit diagnosis and treatment. OBJECTIVE: To demonstrate that TPFM imaging of NMSC can occur within minutes of obtaining biopsies and provide similar histological features to those of conventional histology and evaluate TPFM diagnostic performance with respect to conventional histology. DESIGN, SETTING, AND PARTICIPANTS: This comparative effectiveness pilot study examined 29 freshly excised biopsies from confirmed NMSC lesions in patients presenting for treatment. Biopsies underwent imaging immediately with TPFM on site at Rochester Dermatologic Surgery (Victor, New York) between October 2019 and August 2021. The imaged biopsies were subsequently submitted for paraffin histology to produce coregistered images. Twelve of these coregistered image pairs (41.4%) were used as a training set. Fifteen (51.7%) were used in a masked evaluation by a board-certified dermatopathologist. Two (6.9%) were excluded from the study before evaluation because they could not be coregistered. MAIN OUTCOMES AND MEASURES: Sensitivity, specificity, and accuracy of TPFM for NMSC biopsies were evaluated compared with conventional histology. RESULTS: Fourteen of the 15 biopsy specimens (93.3%) in the evaluation set were identically diagnosed with TPFM and paraffin histology. The TPFM had 100% sensitivity (95% CI, 48%-100%), 100% specificity (95% CI, 69%-100%), and 100% accuracy (95% CI, 78%-100%) for basal cell carcinoma diagnosis. For squamous cell carcinoma diagnosis, TPFM had 89% sensitivity (95% CI, 52%-100), 100% specificity (95% CI, 54%-100%), and 93% accuracy (95% CI, 68%-100%). For overall NMSC diagnosis, TPFM had a 93% sensitivity (95% CI, 66%-100%), 100% specificity (95% CI, 3%-100%), and 93% accuracy (95% CI, 68%-100%). Examination of the 1 discordant pair revealed mismatched imaging planes as the source of error. CONCLUSIONS AND RELEVANCE: The results of this comparative effectiveness pilot study suggest that TPFM captures histological characteristics of NMSC that are present in conventional histology, which reveals its potential as a rapid, point-of-care diagnostic alternative that does not need extensive sample preparation or retraining for image evaluation. Further validation of TPFM imaging performed for a larger cohort is needed to fully evaluate its diagnostic accuracy and potential effect within the field.
In the present study, total and partial charge changing cross-sections of 300A MeV Fe26+ ion beam in aluminum target were measured by a new system of analysis installed with the Leica QWin Plus ...software. The CR39 nuclear track detectors were used to identify the incident charged particles and their fragments. The CR39 detectors just before and just after the target were calibrated and found to have the same charge response and the charge resolution, which were 0.19e and 0.20e, respectively. The response points were fitted with a polynomial of degree one and all the points are within the limits of experimental errors. The value of total charge changing cross-section was calculated to be stot=(1663+/-236) mb. To determine the partial charge changing cross-sections for DZ=-23,-22,...,-1, number of events corresponding to each fragment were determined from multiple Gaussian fitting of diameter distributions within 95.5% confidence levels and the numbers of incident and survived beam ions were counted within 99.7% confidence levels. Charge pick-up cross-section for DZ=+1 was calculated and is (92+/-6) mb.
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