Abstract
As a novel X-ray focusing technology, lobster-eye micropore optics (MPO) feature both a wide observing field of view and true imaging capability, promising sky monitoring with significantly ...improved sensitivity and spatial resolution in soft X-rays. Since first proposed by Angel, the optics have been extensively studied, developed and trialed over the past decades. In this Letter, we report on the first-light results from a flight experiment of the Lobster Eye Imager for Astronomy, a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission. The piggyback imager, launched in 2022 July, has a mostly unvignetted field of view of 18.°6 × 18.°6. Its spatial resolution is in the range of 4′–7′ in FWHM and the focal spot effective area is 2–3 cm
2
, both showing only mild fluctuations across the field of view. We present images of the Galactic center region, Sco X-1, and the diffuse Cygnus Loop nebular taken in snapshot observations over 0.5–4 keV. These are truly wide-field X-ray images of celestial bodies observed, for the first time, by a focusing imaging telescope. Initial analyses of the in-flight data show excellent agreement between the observed images and the on-ground calibration and simulations. The instrument and its characterization are briefly described, as well as the flight experiment. The results provide a solid basis for the development of the present and proposed wide-field X-ray missions using lobster-eye MPO.
Dapsone is an important medication for the treatment of leprosy, but a life-threatening drug hypersensitivity syndrome develops in some patients. In this report from China, an
HLA-B
locus is ...identified as a strong genetic risk factor for the syndrome.
Dapsone (4-4′-sulfonyldianiline), which was first synthesized in 1908,
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is both an antibiotic and an antiinflammatory agent. Dapsone alone or in combination with other drugs has been used for the prevention and treatment of infectious diseases (e.g., leprosy, malaria, and actinomycetoma, as well as
Pneumocystis jirovecii
pneumonia in persons with human immunodeficiency virus HIV infection) and chronic inflammatory diseases characterized by the infiltration of neutrophils or eosinophils (e.g., dermatitis herpetiformis, linear IgA dermatosis, subcorneal pustular dermatosis, and erythema elevatum diutinum).
2
,
3
About 0.5 to 3.6% of persons treated with dapsone have a drug hypersensitivity syndrome,
3
–
5
which was first described by . . .
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Three thiadiazole derivatives with different substituent groups, 2-(benzylthio)-5-methyl-1,3,4-thiadiazole(BMT), 2-(benzylthio)-5-(butylthio)-1,3,4-thiadiazole(BBT), and ...5-(benzylthio)-1,3,4-thiadiazole-2-thiol(BTT), were synthesized and studied as the corrosion inhibitors for N80 carbon steel in CO2-saturated oilfield produced water. It is found that the synthesized thiadiazole derivatives could effectively inhibit the corrosion of N80 carbon steel by chemisorption. The corrosion inhibition performance of the organic compounds is in the order: BTT > BBT > BMT. The theoretical calculations indicate that the tautomeric transformation from thiol-BTT to thione-BTT may be responsible for the high inhibition performance of BTT.
First experimental proof of a clear and strong dependence of the standard phase scintillation index (σφ) derived using Global Positioning System measurements on the ionospheric plasma flow around the ...noon sector of polar ionosphere is presented. σφ shows a strong linear dependence on the plasma drift speed measured by the Super Dual Auroral Radar Network radars, whereas the amplitude scintillation index (S4) does not. This observed dependence can be explained as a consequence of Fresnel frequency dependence of the relative drift and the used constant cutoff frequency (0.1 Hz) to detrend the data for obtaining standard σφ. The lack of dependence of S4 on the drift speed possibly eliminates the plasma instability mechanism(s) involved as a cause of the dependence. These observations further confirm that the standard phase scintillation index is much more sensitive to plasma flow; therefore, utmost care must be taken when identifying phase scintillation (diffractive phase variations) from refractive (deterministic) phase variations, especially in the polar region where the ionospheric plasma drift is much larger than in equatorial and midlatitude regions.
Key Points
A clear strong linear dependence of phase scintillation index on the plasma drift speed around noon sector of the polar ionosphere is presented
Observed dependence can be very possibly explained by the dependence of the shifted Fresnel frequency from the relative drift
Amplifies the importance of using dynamic cutoff frequency in detrending the phase of GPS signal in the polar region
Magnetic flux transfer events (FTEs) are signatures of unsteady magnetic reconnection, often observed at planetary magnetopauses. Their generation mechanism, a key ingredient determining how they ...regulate the transfer of solar wind energy into magnetospheres, is still largely unknown. We report THEMIS spacecraft observations on 2007‐06‐14 of an FTE generated by multiple X‐line reconnection at the dayside magnetopause. The evidence consists of (1) two oppositely‐directed ion jets converging toward the FTE that was slowly moving southward, (2) the cross‐section of the FTE core being elongated along the magnetopause normal, probably squeezed by the oppositely‐directed jets, and (3) bidirectional field‐aligned fluxes of energetic electrons in the magnetosheath, indicating reconnection on both sides of the FTE. The observations agree well with a global magnetohydrodynamic model of the FTE generation under large geomagnetic dipole tilt, which implies the efficiency of magnetic flux transport into the magnetotail being lower for larger dipole tilt.
Aims
This study aimed to explore potential drug targets of Streptococcus suis at the system level.
Methods and Results
A homologous protein mapping method was used in the construction of a ...protein–protein interaction (PPI) network of S. suis, which presented 1147 non‐redundant interaction pairs among 286 proteins. The parameters of PPI networks were calculated and showed scale‐free network properties. In all, 41 possibly essential proteins identified from 47 highly connected proteins were selected as potential drug target candidates. Of these proteins, 30 were already regarded as drug targets in other bacterial species. Six transporters with high connections to other functional proteins were identified as probably not essential but important functional proteins. Afterward, the subnetwork centred with cell division protein FtsZ was used in confirming the PPI network through bacterial two‐hybrid analysis.
Conclusions
The predicted PPI network covers 13·04% of the proteome in S. suis. The selected 41 potential drug target candidates are conserved between S. suis and several model bacteria.
Significance and Impact of the Study
The predictions included proteins known to be drug targets, and a verifying experiment confirmed the reliability of predicted interactions. This work is the first to present systematic computational PPI data for S. suis and provides potential drug targets, which are valuable in exploring novel anti‐streptococcus drugs.
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.
High-β_{θe} (a ratio of the electron thermal pressure to the poloidal magnetic pressure) steady-state long-pulse plasmas with steep central electron temperature gradient are achieved in the ...Experimental Advanced Superconducting Tokamak. An intrinsic current is observed to be modulated by turbulence driven by the electron temperature gradient. This turbulent current is generated in the countercurrent direction and can reach a maximum ratio of 25% of the bootstrap current. Gyrokinetic simulations and experimental observations indicate that the turbulence is the electron temperature gradient mode (ETG). The dominant mechanism for the turbulent current generation is due to the divergence of ETG-driven residual flux of current. Good agreement has been found between experiments and theory for the critical value of the electron temperature gradient triggering ETG and for the level of the turbulent current. The maximum values of turbulent current and electron temperature gradient lead to the destabilization of an m/n=1/1 kink mode, which by counteraction reduces the turbulence level (m and n are the poloidal and toroidal mode number, respectively). These observations suggest that the self-regulation system including turbulence, turbulent current, and kink mode is a contributing mechanism for sustaining the steady-state long-pulse high-β_{θe} regime.
A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or ...precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.
The genus Chaetomium fungi are considered to be a rich source of novel and bioactive secondary metabolites of great importance. Up till now, a variety of more than 200 secondary metabolites belonging ...to diverse structural types of chaetoglobosins, epipolythiodioxopiperazines, azaphilones, xanthones, anthraquinones, chromones, depsidones, terpenoids, and steroids have been discovered. Most of these fungal metabolites exhibited antitumor, cytotoxic, antimalarial, enzyme inhibitory, antibiotic, and other activities. This review covers the extraction, structure elucidation, structural diversity, and biological activities of natural products isolated from about 30 fungi associated with marine- and terrestrial- origins, and highlights some bioactive compounds as well as their mechanisms of action and structure-activity relationships.
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