Compact atom source using fiber-based pulsed laser ablation

We designed, demonstrated, and characterized an atom source based on fiber-based pulsed laser ablation. By using commercially available miniature lens system for focusing nanosecond pulsed laser of up to 225~$\mu$J delivered through a multimode fiber of 105~$\mu$m core, we successfully ablate a SrTiO$_3$ target and generate a jet of neutral strontium atoms, though our method can be applied to other transparent ablation targets containing materials under concern. Our device endures 6\,000 cycles of pulse delivery and irradiation without noticeable damage on the fiber facets and lenses. The generated strontium beam is characterized with spectroscopic method and is revealed to exhibit the transverse temperature of 800~K and longitudinal velocity of 2\,300~m/s, which are typical of pulsed-laser-ablation-based atom source. The number of atoms generated by a single ablation pulse is estimated to be $2\times 10^5$. Our device provides a compact, cryo-compatible fiber-pigtailed atom source with minimized device footprints and reduced complexity of vacuum systems to further promote the developments of cold-atom experiments. It may also find interesting applications in atomic and molecular sciences.Comment: 4 pages, 3 figure

Optimization temperature sensitivity using the optically detected magnetic resonance spectrum of a nitrogen-vacancy center ensemble

Temperature sensing with nitrogen vacancy (NV) centers using quantum techniques is very promising and further development is expected. Recently, the optically detected magnetic resonance (ODMR) spectrum of a high-density ensemble of the NV centers was reproduced with noise parameters [inhomogeneous magnetic field, inhomogeneous strain (electric field) distribution, and homogeneous broadening] of the NV center ensemble. In this study, we use ODMR to estimate the noise parameters of the NV centers in several diamonds. These parameters strongly depend on the spin concentration. This knowledge is then applied to theoretically predict the temperature sensitivity. Using the diffraction-limited volume of 0.1 micron^3, which is the typical limit in confocal microscopy, the optimal sensitivity is estimated to be around 0.76 mK/Hz^(1/2) with an NV center concentration of 5.0e10^17/cm^3. This sensitivity is much higher than previously reported sensitivities, demonstrating the excellent potential of temperature sensing with NV centers.Comment: 17 pages, 4 figures, 1 tabl

Investigation by Imaging Mass Spectrometry of Biomarker Candidates for Aging in the Hair Cortex

BACKGROUND: Human hair is one of the essential components that define appearance and is a useful source of samples for non-invasive biomonitoring. We describe a novel application of imaging mass spectrometry (IMS) of hair biomolecules for advanced molecular characterization and a better understanding of hair aging. As a cosmetic and biomedical application, molecules whose levels in hair altered with aging were comprehensively investigated. METHODS: Human hair was collected from 15 young (20±5 years old) and 15 older (50±5 years old) volunteers. Matrix-free laser desorption/ionization IMS was used to visualize molecular distribution in the hair sections. Hair-specific ions displaying a significant difference in the intensities between the 2 age groups were extracted as candidate markers for aging. Tissue localization of the molecules and alterations in their levels in the cortex and medulla in the young and old groups were determined. RESULTS: Among the 31 molecules detected specifically in hair sections, 2--one at m/z 153.00, tentatively assigned to be dihydrouracil, and the other at m/z 207.04, identified to be 3,4-dihydroxymandelic acid (DHMA)--exhibited a higher signal intensity in the young group than in the old, and 1 molecule at m/z 164.00, presumed to be O-phosphoethanolamine, displayed a higher intensity in the old group. Among the 3, putative O-phosphoethanolamine showed a cortex-specific distribution. The 3 molecules in cortex presented the same pattern of alteration in signal intensity with aging, whereas those in medulla did not exhibit significant alteration. CONCLUSION: Three molecules whose levels in hair altered with age were extracted. While they are all possible markers for aging, putative dihydrouracil and DHMA, are also suspected to play a role in maintaining hair properties and could be targets for cosmetic supplementation. Mapping of ion localization in hair by IMS is a powerful method to extract biomolecules in specified regions and determine their tissue distribution

Association of exposure level to passive smoking with hypertension among lifetime nonsmokers in Japan : a cross-sectional study

Brief exposure to passive smoking immediately elevates blood pressure. However, little is known about the association between exposure to passive smoking and chronic hypertension. We aimed to examine this association in a cross-sectional study, after controlling multiple potential confounders. Participants included 32,098 lifetime nonsmokers (7,216 men and 24,882 women) enrolled in the Japan Multi-Institutional Collaborative Cohort Study. Passive smoking was assessed using a self-administered questionnaire. The single question about exposure to passive smoking had five response options: “sometimes or almost never,” “almost every day, 2 hours/day or less,” “almost every day, 2 to 4 hours/day,” “almost every day, 4 to 6 hours/day,” and “almost every day, 6 hours/day or longer.” Hypertension was defined as any of the following: systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medication. Multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for hypertension were estimated by exposure level to passive smoking using unconditional logistic regression models. The multivariate-adjusted OR for hypertension in those exposed almost every day was 1.11 (95% CI: 1.03–1.20) compared with those exposed sometimes or almost never. The OR for a 1-hour per day increase in exposure was 1.03 (95% CI: 1.01–1.06, P for trend = .006). This association was stronger in men than in women; the ORs were 1.08 (95% CI: 1.01–1.15, P for trend = .036) and 1.03 (95% CI: 1.00–1.05, P for trend = .055), respectively. Our findings suggest importance of tobacco smoke control for preventing hypertension

Sedentary Time and All-Cause Mortality

BACKGROUND: This study aimed to determine the association between sedentary time and mortality with regard to leisure‐time physical activity with or without cardiometabolic diseases such as hypertension, dyslipidemia, and diabetes mellitus. METHODS AND RESULTS: Using data from the J‐MICC (Japan Multi‐Institutional Collaborative Cohort) Study, 64 456 participants (29 022 men, 35 434 women) were analyzed. Hazard ratios (HRs) and 95% CIs were used to characterize the relative risk of all‐cause mortality to evaluate its association with sedentary time (categorical variables: <5, 5 to <7, 7 to <9, ≥9 h/d and 2‐hour increments in exposure) according to the self‐reported hypertension, dyslipidemia, and diabetes mellitus using a Cox proportional hazards model. A total of 2257 participants died during 7.7 years of follow‐up. The corresponding HRs for each 2‐hour increment in sedentary time among participants with all factors, no factors, hypertension, dyslipidemia, and diabetes mellitus were 1.153 (95% CI, 1.114–1.194), 1.125 (95% CI, 1.074–1.179), 1.202 (95% CI, 1.129–1.279), 1.176 (95% CI, 1.087–1.273), and 1.272 (95% CI, 1.159–1.396), respectively. Furthermore, when analyzed according to the combined different factors (hypertension, dyslipidemia, and diabetes mellitus), HRs increased with each additional factor, and participants reporting all 3 conditions had the highest HR of 1.417 (95% CI, 1.162–1.728) independently of leisure‐time metabolic equivalents. CONCLUSIONS: The association between sedentary time and increased mortality is stronger among patients with hypertension, dyslipidemia, and diabetes mellitus regardless of leisure‐time physical activity in a large Japanese population