By matching infrared-selected, massive young stellar objects (MYSOs) and compact H ii regions in the Red MSX Source survey to massive clumps found in the submillimetre ATLASGAL (APEX Telescope Large ...Area Survey of the Galaxy) survey, we have identified ∼1000 embedded young massive stars between 280° < ℓ < 350° and 10° < ℓ < 60° with | b | < 1
$_{.}^{\circ}$
5. Combined with an existing sample of radio-selected methanol masers and compact H ii regions, the result is a catalogue of ∼1700 massive stars embedded within ∼1300 clumps located across the inner Galaxy, containing three observationally distinct subsamples, methanol-maser, MYSO and H ii-region associations, covering the most important tracers of massive star formation, thought to represent key stages of evolution. We find that massive star formation is strongly correlated with the regions of highest column density in spherical, centrally condensed clumps. We find no significant differences between the three samples in clump structure or the relative location of the embedded stars, which suggests that the structure of a clump is set before the onset of star formation, and changes little as the embedded object evolves towards the main sequence. There is a strong linear correlation between clump mass and bolometric luminosity, with the most massive stars forming in the most massive clumps. We find that the MYSO and H ii-region subsamples are likely to cover a similar range of evolutionary stages and that the majority are near the end of their main accretion phase. We find few infrared-bright MYSOs associated with the most massive clumps, probably due to very short pre-main-sequence lifetimes in the most luminous sources.
Abstract
Low dimensional quantum magnets are interesting because of the emerging collective behavior arising from strong quantum fluctuations. The one-dimensional (1D)
S
= 1/2 Heisenberg ...antiferromagnet is a paradigmatic example, whose low-energy excitations, known as spinons, carry fractional spin
S
= 1/2. These fractional modes can be reconfined by the application of a staggered magnetic field. Even though considerable progress has been made in the theoretical understanding of such magnets, experimental realizations of this low-dimensional physics are relatively rare. This is particularly true for rare-earth-based magnets because of the large effective spin anisotropy induced by the combination of strong spin–orbit coupling and crystal field splitting. Here, we demonstrate that the rare-earth perovskite YbAlO
3
provides a realization of a quantum spin
S
= 1/2 chain material exhibiting both quantum critical Tomonaga–Luttinger liquid behavior and spinon confinement–deconfinement transitions in different regions of magnetic field–temperature phase diagram.
Understanding the microscopic processes affecting the bulk thermal conductivity is crucial to develop more efficient thermoelectric materials. PbTe is currently one of the leading thermoelectric ...materials, largely thanks to its low thermal conductivity. However, the origin of this low thermal conductivity in a simple rocksalt structure has so far been elusive. Using a combination of inelastic neutron scattering measurements and first-principles computations of the phonons, we identify a strong anharmonic coupling between the ferroelectric transverse optic mode and the longitudinal acoustic modes in PbTe. This interaction extends over a large portion of reciprocal space, and directly affects the heat-carrying longitudinal acoustic phonons. The longitudinal acoustic-transverse optic anharmonic coupling is likely to play a central role in explaining the low thermal conductivity of PbTe. The present results provide a microscopic picture of why many good thermoelectric materials are found near a lattice instability of the ferroelectric type.
Objectives
To assess the cost‐effectiveness of uterine artery embolisation (UAE) and myomectomy for women with symptomatic uterine fibroids wishing to avoid hysterectomy.
Design
Economic evaluation ...alongside the FEMME randomised controlled trial.
Setting
29 UK hospitals.
Population
Premenopausal women who had symptomatic uterine fibroids amenable to UAE or myomectomy wishing to avoid hysterectomy. 254 women were randomised to UAE (127) and myomectomy (127).
Methods
A within‐trial cost–utility analysis was conducted from the perspective of the UK NHS.
Main outcome measures
Quality‐adjusted life years (QALYs) measured using the EuroQoL EQ‐5D‐3L, combined with costs to estimate cost‐effectiveness over 2 and 4 years of follow‐up.
Results
Over a 2‐year time horizon, UAE was associated with higher mean costs (difference £645; 95% CI −1381 to 2580) and lower QALYs (difference −0.09; 95% CI −0.11 to −0.04) when compared with myomectomy. Similar results were observed over the 4‐year time horizon. Thus, UAE was dominated by myomectomy. Results of the sensitivity analyses were consistent with the base case results for both years. Over 2 years, UAE was associated with higher costs (difference £456; 95% CI −1823 to 3164) and lower QALYs (difference −0.06; 95% CI −0.11 to −0.02).
Conclusions
Myomectomy is a cost‐effective option for the treatment of uterine fibroids. The differences in costs and QALYs are small. Women should be fully informed and have the option to choose between the two procedures.
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Fully informed women with uterine fibroids should have a choice between uterine artery embolisation or myomectomy.
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Fully informed women with uterine fibroids should have a choice between uterine artery embolisation or myomectomy.
Radio continuum observations using the Australia telescope compact array at 5.5, 9.0, 17.0 and 22.8 GHz have detected free–free emission associated with 45 of 49 massive young stellar objects and ...H ii regions. Of these, 26 sources are classified as ionized jets (12 of which are candidates), 2 as ambiguous jets or disc winds, 1 as a disc-wind, 14 as H ii regions and 2 were unable to be categorized. Classification as ionized jets is based upon morphology, radio flux and spectral index, in conjunction with previous observational results at other wavelengths. Radio luminosity and momentum are found to scale with bolometric luminosity in the same way as low-mass jets, indicating a common mechanism for jet production across all masses. In 13 of the jets, we see associated non-thermal/optically thin lobes resulting from shocks either internal to the jet and/or at working surfaces. 10 jets display non-thermal (synchrotron emission) spectra in their lobes, with an average spectral index of α = −0.55 consistent with Fermi acceleration in shocks. This shows that magnetic fields are present, in agreement with models of jet formation incorporating magnetic fields. Since the production of collimated radio jets is associated with accretion processes, the results presented in this paper support the picture of disc-mediated accretion for the formation of massive stars with an upper limit on the jet phase lasting approximately 6.5 × 104 yr. Typical mass-loss rates in the jet are found to be 1.4 × 10−5 M⊙ yr−1 with associated momentum rates of the order of (1–2) × 10−2 M⊙ km s−1 yr−1.
Background
Vasomotor symptoms (VMSs) are the hallmarks of menopause, occurring in approximately 75% of postmenopausal women in the UK, and are severe in 25%.
Objectives
To identify which treatments ...are most clinically effective for the relief of VMSs for women in natural menopause without hysterectomy.
Search strategy
English publications in MEDLINE, Embase, and The Cochrane Library up to 13 January 2015 were searched.
Selection criteria
Randomised controlled trials (RCTs) of treatments for women with a uterus for the outcomes of frequency of VMSs (up to 26 weeks), vaginal bleeding, and discontinuation.
Data collection and analysis
Bayesian network meta‐analysis (NMA) using mean ratios (MRs) and odd ratios (ORs).
Main results
Across the three networks, 47 RCTs of 16 treatment classes (n = 8326 women) were included. When compared with placebo, transdermal estradiol and progestogen (O+P) had the highest probability of being the most effective treatment for VMS relief (69.8%; MR 0.23; 95% credible interval, 95% CrI 0.09–0.57), whereas oral O+P was ranked lower than transdermal O+P, although oral and transdermal O+P were no different for this outcome (MR 2.23; 95% CrI 0.7–7.1). Isoflavones and black cohosh were more effective than placebo, although not significantly better than O+P. Not only were selective serotonin reuptake inhibitors (SSRIs) or serotonin‐norepinephrine reuptake inhibitors (SNRIs) found to be ineffective in relieving VMSs, but they also had significantly higher odds of discontinuation than placebo. Limited data were available for bleeding, therefore no conclusions could be made.
Conclusion
For women who have not undergone hysterectomy, transdermal O+P was the most effective treatment for VMS relief.
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Which treatment best relieves menopause flushes? Results from the #NICE guideline network meta‐analysis.
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Which treatment best relieves menopause flushes? Results from the #NICE guideline network meta‐analysis.
Uterine fibroids cause heavy prolonged bleeding, pain, pressure symptoms and subfertility. The traditional method of treatment has been surgery as medical therapies have not proven effective. Uterine ...artery embolization has been reported to be an effective and safe alternative to treat fibroids in women not desiring future fertility. There is a significant body of evidence that is based on case controlled studies and case reports. This is an update of the review previously published in 2012.
To review the benefits and risks of uterine artery embolization (UAE) versus other medical or surgical interventions for symptomatic uterine fibroids.
We searched sources including the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and trial registries. The search was last conducted in April 2014. We contacted authors of eligible randomised controlled trials to request unpublished data.
Randomised controlled trials (RCTs) of UAE versus any medical or surgical therapy for symptomatic uterine fibroids. The primary outcomes of the review were patient satisfaction and live birth rate (among women seeking live birth).
Two of the authors (AS and JKG) independently selected studies, assessed quality and extracted data. Evidence quality was assessed using GRADE methods.
Seven RCTs with 793 women were included in this review. Three trials compared UAE with abdominal hysterectomy, two trials compared UAE with myomectomy, and two trials compared UAE with either type of surgery (53 hysterectomies and 62 myomectomies).With regard to patient satisfaction rates, our findings were consistent with satisfaction rates being up to 41% lower or up to 48% higher with UAE compared to surgery within 24 months of having the procedure (odds ratio (OR) 0.94; 95% confidence interval (CI) 0.59 to 1.48, 6 trials, 640 women, I(2) = 5%, moderate quality evidence). Findings were also inconclusive at five years of follow-up (OR 0.90; 95% CI 0.45 to 1.80, 2 trials, 295 women, I(2) = 0%, moderate quality evidence). There was some indication that UAE may be associated with less favourable fertility outcomes than myomectomy, but it was very low quality evidence from a subgroup of a single study and should be regarded with extreme caution (live birth: OR 0.26; 95% CI 0.08 to 0.84; pregnancy: OR 0.29; 95% CI 0.10 to 0.85, 1 study, 66 women).Similarly, for several safety outcomes our findings showed evidence of a substantially higher risk of adverse events in either arm or of no difference between the groups. This applied to intra-procedural complications (OR 0.91; 95% CI 0.42 to 1.97, 4 trials, 452 women, I(2) = 40%, low quality evidence), major complications within one year (OR 0.65; 95% CI 0.33 to 1.26, 5 trials, 611 women, I(2) = 4%, moderate quality evidence) and major complications within five years (OR 0.56; CI 0.27 to 1.18, 2 trials, 268 women). However, the rate of minor complications within one year was higher in the UAE group (OR 1.99; CI 1.41 to 2.81, 6 trials, 735 women, I(2) = 0%, moderate quality evidence) and two trials found a higher minor complication rate in the UAE group at up to five years (OR 2.93; CI 1.73 to 4.93, 2 trials, 268 women).UAE was associated with a higher rate of further surgical interventions (re-interventions within 2 years: OR 3.72; 95% CI 2.28 to 6.04, 6 trials, 732 women, I(2) = 45%, moderate quality evidence; within 5 years: OR 5.79; 95% CI 2.65 to 12.65, 2 trials, 289 women, I(2) = 65%). If we assumed that 7% of women will require further surgery within two years of hysterectomy or myomectomy, between 15% and 32% will require further surgery within two years of UAE.The evidence suggested that women in the UAE group were less likely to require a blood transfusion than women receiving surgery (OR 0.07; 95% CI 0.01 to 0.52, 2 trials, 277 women, I(2) = 0%). UAE was also associated with a shorter procedural time (two studies), shorter length of hospital stay (seven studies) and faster resumption of usual activities (six studies) in all studies that measured these outcomes; however, most of these data could not be pooled due to heterogeneity between the studies.The quality of the evidence varied, and was very low for live birth, moderate for satisfaction ratings, and moderate for most safety outcomes. The main limitations in the evidence were serious imprecision due to wide confidence intervals, failure to clearly report methods, and lack of blinding for subjective outcomes.
When we compared patient satisfaction rates at up to two years following UAE versus surgery (myomectomy or hysterectomy) our findings are that there is no evidence of a difference between the interventions. Findings at five year follow-up were similarly inconclusive. There was very low quality evidence to suggest that myomectomy may be associated with better fertility outcomes than UAE, but this information was only available from a selected subgroup in one small trial.We found no clear evidence of a difference between UAE and surgery in the risk of major complications, but UAE was associated with a higher rate of minor complications and an increased likelihood of requiring surgical intervention within two to five years of the initial procedure. If we assume that 7% of women will require further surgery within two years of hysterectomy or myomectomy, between 15% and 32% will require further surgery within two years of UAE. This increase in the surgical re-intervention rate may balance out any initial cost advantage of UAE. Thus although UAE is a safe, minimally invasive alternative to surgery, patient selection and counselling are paramount due to the much higher risk of requiring further surgical intervention.
Uterine fibroids, the most common type of tumor among women of reproductive age, are associated with heavy menstrual bleeding, abdominal discomfort, subfertility, and a reduced quality of life. For ...women who wish to preserve their uterus and who have not had a response to medical treatment, myomectomy and uterine-artery embolization are therapeutic options.
We conducted a multicenter, randomized, open-label trial to evaluate myomectomy, as compared with uterine-artery embolization, in women who had symptomatic uterine fibroids and did not want to undergo hysterectomy. Procedural options included open abdominal, laparoscopic, or hysteroscopic myomectomy. The primary outcome was fibroid-related quality of life, as assessed by the score on the health-related quality-of-life domain of the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire (scores range from 0 to 100, with higher scores indicating a better quality of life) at 2 years; adjustment was made for the baseline score.
A total of 254 women, recruited at 29 hospitals in the United Kingdom, were randomly assigned: 127 to the myomectomy group (of whom 105 underwent myomectomy) and 127 to the uterine-artery embolization group (of whom 98 underwent embolization). Data on the primary outcome were available for 206 women (81%). In the intention-to-treat analysis, the mean (±SD) score on the health-related quality-of-life domain of the UFS-QOL questionnaire at 2 years was 84.6±21.5 in the myomectomy group and 80.0±22.0 in the uterine-artery embolization group (mean adjusted difference with complete case analysis, 8.0 points; 95% confidence interval CI, 1.8 to 14.1; P = 0.01; mean adjusted difference with missing responses imputed, 6.5 points; 95% CI, 1.1 to 11.9). Perioperative and postoperative complications from all initial procedures, irrespective of adherence to the assigned procedure, occurred in 29% of the women in the myomectomy group and in 24% of the women in the uterine-artery embolization group.
Among women with symptomatic uterine fibroids, those who underwent myomectomy had a better fibroid-related quality of life at 2 years than those who underwent uterine-artery embolization. (Funded by the National Institute for Health Research Health Technology Assessment program; FEMME Current Controlled Trials number, ISRCTN70772394.).
Low dimensional quantum magnets are interesting because of the emerging collective behavior arising from strong quantum fluctuations. The one-dimensional (1D) S = 1/2 Heisenberg antiferromagnet is a ...paradigmatic example, whose low-energy excitations, known as spinons, carry fractional spin S = 1/2. These fractional modes can be reconfined by the application of a staggered magnetic field. Even though considerable progress has been made in the theoretical understanding of such magnets, experimental realizations of this low-dimensional physics are relatively rare. This is particularly true for rare-earth-based magnets because of the large effective spin anisotropy induced by the combination of strong spin-orbit coupling and crystal field splitting. Here, we demonstrate that the rare-earth perovskite YbAlO
provides a realization of a quantum spin S = 1/2 chain material exhibiting both quantum critical Tomonaga-Luttinger liquid behavior and spinon confinement-deconfinement transitions in different regions of magnetic field-temperature phase diagram.
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