13CO(J=1-0) On-the-fly Mapping of the Giant HII Region NGC 604: Variation in Molecular Gas Density and Temperature due to Sequential Star Formation

We present 13CO(J=1-0) line emission observations with the Nobeyama 45-m telescope toward the giant HII region NGC 604 in the spiral galaxy M 33. We detected 13CO(J=1-0) line emission in 3 major giant molecular clouds (GMCs) labeled as GMC-A, B, and C beginning at the north. We derived two line intensity ratios, 13CO(J=1-0)/12CO(J =1-0), R13/12, and 12CO(J=3-2)/12CO(J =1-0), R31, for each GMC at an angular resolution of 25" (100 pc). Averaged values of R13/12 and R31 are 0.06 and 0.31 within the whole GMC-A, 0.11 and 0.67 within the whole GMC-B, and 0.05 and 0.36 within the whole GMC-C, respectively. In addition, we obtained R13/12=0.09\pm0.02 and R31=0.76\pm0.06 at the 12CO(J=1-0) peak position of the GMC-B. Under the Large Velocity Gradient approximation, we determined gas density of 2.8 \times10^3 cm^-3 and kinetic temperature of 33+9-5 K at the 12CO(J=1-0) peak position of the GMC-B. Moreover, we determined 2.5 \times10^3 cm^-3 and 25\pm2 K as averaged values within the whole GMC-B. We concluded that dense molecular gas is formed everywhere in the GMC-B because derived gas density not only at the peak position of the GMC but also averaged over the whole GMC exceeds 10^3 cm^-3. On the other hand, kinetic temperature averaged over the whole GM-B, 25 K, is significantly lower than that at the peak position, 33 K. This is because HII regions are lopsided to the northern part of the GMC-B, thus OB stars can heat only the northern part, including the 12CO(J=1-0) peak position, of this GMC.Comment: 16 pages, 7 figures, PASJ in pres

NRO M33 All Disk Survey of Giant Molecular Clouds (NRO MAGiC): I. HI to H_2 Transition

We present the results of the Nobeyama Radio Observatory (NRO) M33 All Disk (30'x30' or 7.3 kpc x 7.3 kpc) Survey of Giant Molecular Clouds (NRO MAGiC) based on 12CO (1-0) observations using the NRO 45-m telescope. The spatial resolution of the resultant map is 19".3, corresponding to 81 pc, which is sufficient to identify each Giant Molecular Cloud (GMC) in the disk. We found clumpy structures with a typical spatial scale of ~100 pc, corresponding to GMCs, and no diffuse, smoothly distributed component of molecular gas at this sensitivity. Closer inspection of the CO and HI maps suggests that not every CO emission is associated with local HI peaks, particularly in the inner portion of the disk (r < 2 kpc), although most of CO emission is located at the local HI peaks in the outer radii. We found that most uncovered GMCs are accompanied by massive star-forming regions, although the star formation rates (SFRs) vary widely from cloud to cloud. The azimuthally averaged H{\sc i} gas surface density exhibits a flat radial distribution. However, the CO radial distribution shows a significant enhancement within the central 1-2 kpc region, which is very similar to that of the SFR. We obtained a map of the molecular fraction, f_mol = Sigma_H_2/(Sigma_HI+Sigma_H_2, at a 100-pc resolution. This is the first f_mol map covering an entire galaxy with a GMC-scale resolution. We find that f_mol tends to be high near the center. The correlation between f_mol and gas surface density shows two distinct sequences. The presence of two correlation sequences can be explained by differences in metallicity, i.e., higher (~ 2-fold) metallicity in the central region (r< 1.5 kpc) than in the outer parts. Alternatively, differences in scale height can also account for the two sequences, i.e., increased scale height toward the outer disk.Comment: Accepted for publication in PASJ, See http://www.juen.ac.jp/lab/tosaki/paper/astro-ph/2011/tosaki2011.pdf for a version with full resolution figure

Upper limb muscle atrophy associated with in-hospital mortality and physical function impairments in mechanically ventilated critically ill adults : a two-center prospective observational study

Background: Lower limb muscle atrophy is often observed in critically ill patients. Although upper limb muscles can undergo atrophy, it remains unclear how this atrophy is associated with clinical outcomes. We hypothesized that this atrophy is associated with mortality and impairments in physical function. Methods: In this two-center prospective observational study, we included adult patients who were expected to require mechanical ventilation for > 48 h and remain in the intensive care unit (ICU) for > 5 days. We used ultrasound to evaluate the cross-sectional area of the biceps brachii on days 1, 3, 5, and 7 and upon ICU discharge along with assessment of physical functions. The primary outcome was the relationship between muscle atrophy ratio and in-hospital mortality on each measurement day, which was assessed using multivariate analysis. The secondary outcomes were the relationships between upper limb muscle atrophy and Medical Research Council (MRC) score, handgrip strength, ICU Mobility Scale (IMS) score, and Functional Status Score for the ICU (FSS-ICU). Results: Sixty-four patients (43 males; aged 70 ± 13 years) were enrolled. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was 27 (22–30), and in-hospital mortality occurred in 21 (33%) patients. The decreased cross-sectional area of the biceps brachii was not associated with in-hospital mortality on day 3 (p = 0.43) but was associated on days 5 (p = 0.01) and 7 (p < 0.01), which was confirmed after adjusting for sex, age, and APACHE II score. In 27 patients in whom physical functions were assessed, the decrease of the cross-sectional area of the biceps brachii was associated with MRC score (r = 0.47, p = 0.01), handgrip strength (r = 0.50, p = 0.01), and FSS-ICU (r = 0.56, p < 0.01), but not with IMS score (r = 0.35, p = 0.07) upon ICU discharge. Conclusions: Upper limb muscle atrophy was associated with in-hospital mortality and physical function impairments; thus, it is prudent to monitor it

Urinary Titin N-Fragment as a Biomarker of Muscle Atrophy, Intensive Care Unit-Acquired Weakness, and Possible Application for Post-Intensive Care Syndrome

Titin is a giant protein that functions as a molecular spring in sarcomeres. Titin interconnects the contraction of actin-containing thin filaments and myosin-containing thick filaments. Titin breaks down to form urinary titin N-fragments, which are measurable in urine. Urinary titin N-fragment was originally reported to be a useful biomarker in the diagnosis of muscle dystrophy. Recently, the urinary titin N-fragment has been increasingly gaining attention as a novel biomarker of muscle atrophy and intensive care unit-acquired weakness in critically ill patients, in whom titin loss is a possible pathophysiology. Furthermore, several studies have reported that the urinary titin N-fragment also reflected muscle atrophy and weakness in patients with chronic illnesses. It may be used to predict the risk of post-intensive care syndrome or to monitor patients’ condition after hospital discharge for better nutritional and rehabilitation management. We provide several tips on the use of this promising biomarker in post-intensive care syndrome

NRO M33 All-Disk Survey of Giant Molecular Clouds (NRO MAGiC): II. Dense Gas Formation within Giant Molecular Clouds in M33

We report the results of our observations of the 12CO (J=1-0) and 12CO (J=3-2) line emission of 74 major giant molecular clouds (GMCs) within the galactocentric distance of 5.1 kpc in the Local Group galaxy M33. The observations have been conducted as part of the Nobeyama Radio Observatory M33 All-disk survey of Giant Molecular Clouds project (NRO MAGiC). The spatial resolutions are 80 pc for 12CO (J=1-0) and 100 pc for 12CO (J=3-2). We detect 12CO (J=3-2) emission of 65 GMCs successfully. Furthermore, we find that the correlation between the surface density of the star formation rate, which is derived from a linear combination of Halpha and 24um emissions, and the 12CO (J=3-2) integrated intensity still holds at this scale. This result show that the star-forming activity is closely associated with warm and dense gases that are traced with the 12CO (J=3-2) line, even in the scale of GMCs. We also find that the GMCs with a high star-forming activity tend to show a high integrated intensity ratio (R3-2/1-0). Moreover, we also observe a mass-dependent trend of R3-2/1-0 for the GMCs with a low star-forming activity. From these results, we speculate that the R3-2/1-0 values of the GMCs with a low star-forming activity mainly depend on the dense gas fraction and not on the temperature, and therefore, the dense gas fraction increases with the mass of GMCs, at least in the GMCs with a low star-forming activity.Comment: 17 pages, 5 figures, Accepted for publication in PASJ, 2012, Vol. 64, No.

ALMA Observations toward the starburst dwarf galaxy NGC 5253: I. Molecular cloud properties and scaling relations

We present high-spatial-resolution (\sim 0\farcs2, or $\sim$3\,pc) CO(2--1) observations of the nearest young starburst dwarf galaxy, NGC\,5253, taken with the Atacama Large Millimeter/submillimeter Array. We have identified 118 molecular clouds with average values of 4.3\,pc in radius and 2.2\,\kms\, in velocity dispersion, which comprise the molecular cloud complexes observed previously with $\sim$100\,pc resolution. We derive for the first time in this galaxy the $I{\rm (CO)}$--$N$(H$_2$) conversion factor, $X$ = $4.1^{+5.9}_{-2.4}\times10^{20}$\,cm$^{-2}$(K\,\kms)$^{-1}$, based on the virial method. The line-width and mass-to-size relations of the resolved molecular clouds present an offset on average toward higher line-widths and masses with respect to quiescent regions in other nearby spiral galaxies and our Galaxy. The offset in the scaling relation reaches its maximum in regions close to the central starburst, where velocity dispersions are $\sim$ 0.5 dex higher and gas mass surface densities are as high as $\Sigma_{\rm H_2}$ = 10$^3$\,\Msol\,pc $^{-2}$. These central clouds are gravitationally bound despite the high internal pressure. A spatial comparison with star clusters found in the literature enables us to identify six clouds that are associated with young star clusters. Furthermore, the star formation efficiencies (SFEs) of some of these clouds exceed those found in star-cluster-forming clouds within our Galaxy. We conclude that once a super star cluster is formed, the parent molecular clouds are rapidly dispersed by the destructive stellar feedback, which results in such a high SFE in the central starburst of NGC\,5253.Comment: 18 pages, 11 figures, accepted to Ap

Urinary titin as a biomarker for muscle atrophy

Objective: Although skeletal muscle atrophy is common in critically ill patients, biomarkers associated with muscle atrophy have not been identified reliably. Titin is a spring-like protein found in muscles and has become a measurable biomarker for muscle breakdown. We hypothesized that urinary titin is useful for monitoring muscle atrophy in critically ill patients. Therefore, we investigated urinary titin level and its association with muscle atrophy in critically ill patients. Design: Two-center, prospective observational study Setting: Mixed medical/surgical intensive care unit (ICU) in Japan Patients: Nonsurgical adult patients who were expected to remain in ICU for >5 days Interventions: None Methods: Urine samples were collected on days 1, 2, 3, 5, and 7 of ICU admission. To assess muscle atrophy, rectus femoris cross-sectional area and diaphragm thickness were measured with ultrasound on days 1, 3, 5, and 7. Secondary outcomes included its relationship with ICU-acquired weakness (ICU-AW), ICU Mobility Scale (IMS), and ICU mortality. Measurements and Main Results: Fifty-six patients and 232 urinary titin measurements were included. Urinary titin (normal range: 1–3 pmol/mg Cr) was 27.9 (16.8–59.6), 47.6 (23.5–82.4), 46.6 (24.4–97.6), 38.4 (23.6–83.0), and 49.3 (27.4–92.6) pmol/mg Cr on days 1, 2, 3, 5, and 7, respectively. Cumulative urinary titin level was significantly associated with rectus femoris muscle atrophy on days 3–7 (p < 0.03), although urinary titin level was not associated with change in diaphragm thickness (p = 0.31–0.45). Furthermore, cumulative urinary titin level was associated with incidence of ICU-AW (p = 0.01) and ICU mortality (p = 0.02) but not with IMS (p = 0.18). Conclusions: In nonsurgical critically ill patients, urinary titin level increased 10–30 times compared with the normal level. The increased urinary titin level was associated with lower limb muscle atrophy, incidence of ICU-AW, and ICU mortality

Monitoring of muscle mass in critically ill patients : comparison of ultrasound and two bioelectrical impedance analysis devices

Background: Skeletal muscle atrophy commonly occurs in critically ill patients, and decreased muscle mass is associated with worse clinical outcomes. Muscle mass can be assessed using various tools, including ultrasound and bioelectrical impedance analysis (BIA). However, the effectiveness of muscle mass monitoring is unclear in critically ill patients. This study was conducted to compare ultrasound and BIA for the monitoring of muscle mass in critically ill patients. Methods: We recruited adult patients who were expected to undergo mechanical ventilation for > 48 h and to remain in the intensive care unit (ICU) for > 5 days. On days 1, 3, 5, 7, and 10, muscle mass was evaluated using an ultrasound and two BIA devices (Bioscan: Malton International, England; Physion: Nippon Shooter, Japan). The influence of fluid balance was also evaluated between each measurement day. Results: We analyzed 93 images in 21 patients. The age of the patients was 69 (interquartile range, IQR, 59–74) years, with 16 men and 5 women. The length of ICU stay was 11 days (IQR, 9–25 days). The muscle mass, monitored by ultrasound, decreased progressively by 9.2% (95% confidence interval (CI), 5.9–12.5%), 12.7% (95% CI, 9.3–16.1%), 18.2% (95% CI, 14.7–21.6%), and 21.8% (95% CI, 17.9–25.7%) on days 3, 5, 7, and 10 (p < 0.01), respectively, with no influence of fluid balance (r = 0.04, p = 0.74). The muscle mass did not decrease significantly in both the BIA devices (Bioscan, p = 0.14; Physion, p = 0.60), and an influence of fluid balance was observed (Bioscan, r = 0.37, p < 0.01; Physion, r = 0.51, p < 0.01). The muscle mass assessment at one point between ultrasound and BIA was moderately correlated (Bioscan, r = 0.51, p < 0.01; Physion, r = 0.37, p < 0.01), but the change of muscle mass in the same patient did not correlate between these two devices (Bioscan, r = − 0.05, p = 0.69; Physion, r = 0.23, p = 0.07). Conclusions: Ultrasound is suitable for sequential monitoring of muscle atrophy in critically ill patients. Monitoring by BIA should be carefully interpreted owing to the influence of fluid change