Visualizing individual molecules with chemical recognition is a longstanding target in catalysis, molecular nanotechnology and biotechnology. Molecular vibrations provide a valuable 'fingerprint' for ...such identification. Vibrational spectroscopy based on tip-enhanced Raman scattering allows us to access the spectral signals of molecular species very efficiently via the strong localized plasmonic fields produced at the tip apex. However, the best spatial resolution of the tip-enhanced Raman scattering imaging is still limited to 3-15 nanometres, which is not adequate for resolving a single molecule chemically. Here we demonstrate Raman spectral imaging with spatial resolution below one nanometre, resolving the inner structure and surface configuration of a single molecule. This is achieved by spectrally matching the resonance of the nanocavity plasmon to the molecular vibronic transitions, particularly the downward transition responsible for the emission of Raman photons. This matching is made possible by the extremely precise tuning capability provided by scanning tunnelling microscopy. Experimental evidence suggests that the highly confined and broadband nature of the nanocavity plasmon field in the tunnelling gap is essential for ultrahigh-resolution imaging through the generation of an efficient double-resonance enhancement for both Raman excitation and Raman emission. Our technique not only allows for chemical imaging at the single-molecule level, but also offers a new way to study the optical processes and photochemistry of a single molecule.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Spiral arms shown by different components may not be spatially coincident, which can constrain formation mechanisms of spiral structure in a galaxy. We reassess the spiral arm tangency directions in ...the Milky Way through identifying the bump features in the longitude plots of survey data for infrared stars, radio recombination lines (RRLs), star formation sites, CO, high-density regions in clouds, and H i. The bump peaks are taken as indications for arm tangencies, which are close to the real density peaks near the spiral arm tangency point but often have ∼1° offset to the interior of spiral arms. The arm tangencies identified from the longitude plots for RRLs, H ii regions, methanol masers, CO, high-density gas regions, and H i gas appear nearly the same Galactic longitude, and therefore there is no obvious offset for spiral arms traced by different gas components. However, we find obvious displacements of 1
$_{.}^{\circ}$
3–5
$_{.}^{\circ}$
8 of gaseous bump peaks from the directions of the maximum density of old stars near the tangencies of the Scutum–Centaurus Arm, the northern part of the Near 3 kpc Arm, and maybe also the Sagittarius Arm. The offsets between the density peaks of gas and old stars for spiral arms are comparable with the arm widths, which is consistent with expectations for quasi-stationary density wave in our Galaxy.
Control of the radiative properties of functional molecules near metals is a key issue in nano-optics, and is particularly important in the fields of energy transfer and light manipulation at the ...nanoscale and the development of plasmonic devices. Despite the various vibronic transitions (S1 (vvariant prime) arrow right S0 (v)) available for frequency tuning of fluorescence, the molecular emissions near metals reported to date have been subject to Kasha's rule, with radiative decay from the lowest excited state (S1 (0)) (refs 6-10). Here, we show resonant hot electroluminescence arising directly from higher vibronic levels of the singlet excited state (S1 (vvariant prime > 0)) for porphyrin molecules confined inside a nanocavity in a scanning tunnelling microscope, by spectrally tuning the frequency of plasmons. We also demonstrate the generation of unexpected upconversion electroluminescence. These observations suggest that the local nanocavity plasmons behave like a strong coherent optical source with tunable energy, and can be used to actively control the radiative channels of molecular emitters by means of intense resonance enhancement of both excitation and emission.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Summary
We investigated the secular trends of the incidence and hospitalization cost of hip fracture in Tangshan, China. The incidence of hip fracture and the hospitalization cost were both ...increasing during the observation period.
Introduction
The present study aimed to determine sex-, age-, and fracture type-specific incidence and annual changes in hip fractures in Tangshan, China, between 2007 and 2018.
Methods
We analyzed annual hip fracture incidence using urban hospital data during 2007–2018 and calculated incidence rate/100,000 person years in each age group and sex. We assessed annual changes in incidence among people aged >60 years using linear-by-linear association tests and evaluated hospitalization costs with the Kruskal–Wallis test.
Results
During the study period, we observed an increasing proportion of hip fractures in people >60 years old from 14.2 to 22.79%. Crude hip fracture incidence increased markedly from 140.87 to 306.56/100,000 in women (
p
< 0.01) and from 124.83 to 167.19/100,000 in men (
p
< 0.01) in the age group >60 years. Type-specific analysis indicated significantly increased trends in incidence of cervical and trochanteric fractures among women and cervical fracture among men (
p
< 0.01). In people aged 36–60 years, the trend of hip fracture increased significantly in both sexes. The total and cervical-to-trochanteric ratio in men increased, with significant upward trends (
p
< 0.01). The proportion of cervical fracture was higher than that for trochanteric fracture in women, with stable levels from 2007 to 2018. Hospitalization costs for cervical and trochanteric fractures increased by 51.91% and 53.20%, respectively, during 2011–2018.
Conclusion
Tangshan will have an increasing burden on health care resources attributable to a considerable rise in hip fracture incidence and the older population. Further investigation of risk factors and subsequent implementation of effective measures to prevent hip fracture are needed.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This study evaluated maintenance treatment with niraparib, a potent inhibitor of poly(ADP-ribose) polymerase 1/2, in patients with platinum-sensitive recurrent ovarian cancer.
In this phase III, ...double-blind, placebo-controlled study conducted at 30 centers in China, adults with platinum-sensitive recurrent ovarian cancer who had responded to their most recent platinum-containing chemotherapy were randomized 2 : 1 to receive oral niraparib (300 mg/day) or matched placebo until disease progression or unacceptable toxicity (NCT03705156). Following a protocol amendment, patients with a bodyweight <77 kg or a platelet count <150 × 103/μl received 200 mg/day, and all other patients 300 mg/day, as an individualized starting dose (ISD). Randomization was carried out by an interactive web response system and stratified by BRCA mutation, time to recurrence following penultimate chemotherapy, and response to most recent chemotherapy. The primary endpoint was progression-free survival (PFS) assessed by blinded independent central review.
Between 26 September 2017 and 2 February 2019, 265 patients were randomized to receive niraparib (n = 177) or placebo (n = 88); 249 patients received an ISD (300 mg, n = 14; 200 mg, n = 235) as per protocol. In the intention-to-treat population, median PFS was significantly longer for patients receiving niraparib versus placebo: 18.3 95% confidence interval (CI), 10.9-not evaluable versus 5.4 (95% CI, 3.7-5.7) months hazard ratio (HR) = 0.32; 95% CI, 0.23-0.45; P < 0.0001, and a similar PFS benefit was observed in patients receiving an ISD, regardless of BRCA mutation status. Grade ≥3 treatment-emergent adverse events occurred in 50.8% and 19.3% of patients who received niraparib and placebo, respectively; the most common events were neutrophil count decreased (20.3% versus 8.0%) and anemia (14.7% versus 2.3%).
Niraparib maintenance treatment reduced the risk of disease progression or death by 68% and prolonged PFS compared to placebo in patients with platinum-sensitive recurrent ovarian cancer. Individualized niraparib dosing is effective and safe and should be considered standard practice in this setting.
•Chinese patients with platinum-sensitive recurrent ovarian cancer received maintenance niraparib (n = 177) or placebo (n = 88).•Median PFS was longer for niraparib versus placebo: 18.3 versus 5.4 months (HR = 0.32; 95% CI, 0.23-0.45; P < 0.0001).•Niraparib had a similar PFS benefit for 249 patients receiving individualized dosing based on bodyweight and platelet count.•Grade ≥3 treatment-emergent adverse events occurred in 50.8% and 19.3% of patients who received niraparib and placebo, respectively.•In the niraparib group, Grade ≥3 platelet count decreased/thrombocytopenia occurred in 11.3% of patients.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Context.
The astrometric satellite
Gaia
is expected to significantly increase our knowledge as to the properties of the Milky Way. The
Gaia
Early Data Release 3 (EDR3) provides the most precise ...parallaxes for many OB stars, which can be used to delineate the Galactic spiral structure.
Aims.
We investigate the local spiral structure with the largest sample of spectroscopically confirmed young OB stars available to date, and we compare it with what was traced by the parallax measurements of masers.
Methods.
A sample consisting of three different groups of massive young stars, including O–B2 stars, O–B0 stars and O-type stars with parallax accuracies better than 10% was compiled and used in our analysis.
Results.
The local spiral structures in all four Galactic quadrants within ≈5 kpc of the Sun are clearly delineated in detail. The revealed Galactic spiral pattern outlines a clear sketch of nearby spiral arms, especially in the third and fourth quadrants where the maser parallax data are still absent. These O-type stars densify and extend the spiral structure constructed by using the Very Long Baseline Interferometry maser data alone. The clumped distribution of O-type stars also indicates that the Galaxy spiral structure is inhomogeneous.
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FMFMET, NUK, UL, UM, UPUK
A thermal power plant is an energy conversion system consisting of boilers, turbines, generators and their auxiliary machines respectively. It is a complex multivariable system associated with severe ...nonlinearity, uncertainties and multivariable couplings. These characters will be more evident when the system is working at a higher level energy conversion capacity. In many cases, it is almost impossible to build a mathematical model of the system using conventional analytic methods. The paper presents our recent work in modeling of a 1000 MW ultra supercritical once-through boiler unit of a power plant. Using on-site measurement data, two different structures of neural networks are employed to model the thermal power plant unit. The method is compared with the typical recursive least squares (RLSs) method, which obviously demonstrated the merit of efficiency of the neural networks in modeling of the 1000 MW ultra supercritical unit.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK
Context. The spiral structure of our Milky Way Galaxy is not yet known. HII regions and giant molecular clouds are the most prominent spiral tracers. Models with 2-4 arms have been proposed to ...outline the structure of our Galaxy. Aims. Recently, new data of spiral tracers covering a larger region of the Galactic disk have been published. We wish to outline the spiral structure of the Milky way using all tracer data. Methods. We collected the spiral tracer data of our Milky Way from the literature, namely, HII regions and giant molecular clouds (GMCs). With weighting factors based on the excitation parameters of HII regions or the masses of GMCs, we fitted the distribution of these tracers with models of two, three, four spiral-arms or polynomial spiral arms. The distances of tracers, if not available from stellar or direct measurements, were estimated kinetically from the standard rotation curve of Brand & Blitz (1993, A&A, 275, 67) with R0 = 8.5 kpc, and $\Theta_0$ = 220 km s-1 or the newly fitted rotation curves with R0 = 8.0 kpc and $\Theta_0$ = 220 km s-1 or R0 = 8.4 kpc and $\Theta_0$ = 254 km s-1. Results. We found that the two-arm logarithmic model cannot fit the data in many regions. The three- and the four-arm logarithmic models are able to connect most tracers. However, at least two observed tangential directions cannot be matched by the three- or four-arm model. We composed a polynomial spiral arm model, which can not only fit the tracer distribution but also match observed tangential directions. Using new rotation curves with R0 = 8.0 kpc and $\Theta_0$ = 220 km s-1 and R0 = 8.4 kpc and $\Theta_0$ = 254 km s-1 for the estimation of kinematic distances, we found that the distribution of HII regions and GMCs can fit the models well, although the results do not change significantly compared to the parameters with the standard R0 and $\Theta_0$.
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The spiral structure in the solar neighborhood is an important issue in astronomy. In the past few years, there has been significant progress in observation. The distances for a large number of good ...spiral tracers, i.e., giant molecular clouds, high-mass star-formation region masers, HII regions, O-type stars, and young open clusters, have been accurately estimated, making it possible to depict the detailed properties of nearby spiral arms. In this work, we first give an overview about the research status for the Galaxy’s spiral structure based on different types of tracers. Then the objects with distance uncertainties better than 15% and <0.5 kpc are collected and combined together to depict the spiral structure in the solar neighborhood. Five segments related with the Perseus, Local, Sagittarius-Carina, Scutum-Centaurus, and Norma arms are traced. With the large dataset, the parameters of the nearby arm segments are fitted and updated. Besides the dominant spiral arms, some substructures probably related to arm spurs or feathers are also noticed and discussed.
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