Search

Objective: The present study investigated the predictive diseases progression value of preoperative fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with local advanced cervical cancer (LACC). Methods: In total, 267 patients [median age 58 (range: 27–85) years old] with LACC underwent 18F-FDG PET/CT prior to any treatment. The maximum standardized uptake values (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesion and metastatic lymph nodes were measured on PET/CT and correlated with clinicopathological features and progression-free survival (PFS). Results: The median follow-up was 36.52 (range: 3.09–61.29) months. During the observation period, 80 (30.0%) patients exhibited disease progression. Univariate analysis showed that FIGO stage, concurrent chemoradiotherapy (CRT), serum level of carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC-Ag), primary tumor MTV (pMTV) and TLG (pTLG), lymph nodes SUVmax (nSUVmax) and TLG (nTLG), and total metabolic activity (sMTV, sTLG) were associated with PFS. nSUVmax ≥ 5.29, CEA ≥ 7.11 ng/ml and deficiency of concurrent CRT were independent risk factor for PFS (p = 0.006, p = 0.008, p = 0.014). The 3-year PFS for patients with high nSUVmax were 42.2% compared to 56.3% for low nSUVmax values. Conclusion: Pretreatment cervical and lymph nodes metabolic parameters were associated with PFS in patients with LACC. [ABSTRACT FROM AUTHOR]

As an advanced amorphous material, sp3 amorphous carbon exhibits exceptional mechanical, thermal and optical properties, but it cannot be synthesized by using traditional processes such as fast cooling liquid carbon and an efficient strategy to tune its structure and properties is thus lacking. Here we show that the structures and physical properties of sp3 amorphous carbon can be modified by changing the concentration of carbon pentagons and hexagons in the fullerene precursor from the topological transition point of view. A highly transparent, nearly pure sp3−hybridized bulk amorphous carbon, which inherits more hexagonal-diamond structural feature, was synthesized from C70 at high pressure and high temperature. This amorphous carbon shows more hexagonal-diamond-like clusters, stronger short/medium-range structural order, and significantly enhanced thermal conductivity (36.3 ± 2.2 W m−1 K−1) and higher hardness (109.8 ± 5.6 GPa) compared to that synthesized from C60. Our work thus provides a valid strategy to modify the microstructure of amorphous solids for desirable properties. sp3 amorphous carbon exhibits exceptional mechanical, thermal, and optical properties, but cannot be synthesized using traditional processes. Here authors report a nearly pure sp3−hybridized amorphous carbon synthesized from C70 which shows more short/medium-range order and enhanced thermal conductivity compared to C60. [ABSTRACT FROM AUTHOR]

Amorphous materials inherit short- and medium-range order from the corresponding crystal and thus preserve some of its properties while still exhibiting novel properties1,2. Due to its important applications in technology, amorphous carbon with sp2 or mixed sp2–sp3 hybridization has been explored and prepared3,4, but synthesis of bulk amorphous carbon with sp3 concentration close to 100% remains a challenge. Such materials inherit the short-/medium-range order of diamond and should also inherit its superior properties5. Here, we successfully synthesized millimetre-sized samples—with volumes 103–104 times as large as produced in earlier studies—of transparent, nearly pure sp3 amorphous carbon by heating fullerenes at pressures close to the cage collapse boundary. The material synthesized consists of many randomly oriented clusters with diamond-like short-/medium-range order and possesses the highest hardness (101.9 ± 2.3 GPa), elastic modulus (1,182 ± 40 GPa) and thermal conductivity (26.0 ± 1.3 W m−1 K−1) observed in any known amorphous material. It also exhibits optical bandgaps tunable from 1.85 eV to 2.79 eV. These discoveries contribute to our knowledge about advanced amorphous materials and the synthesis of bulk amorphous materials by high-pressure and high-temperature techniques and may enable new applications for amorphous solids.Preparing amorphous phases of carbon with mostly sp3 bonding in bulk is challenging, but macroscopic samples that are nearly pure sp3 are synthesized here by heating fullerenes at high pressure. [ABSTRACT FROM AUTHOR]

The Insight-Hard X-ray Modulation Telescope (Insight-HXMT) is a broadband X-ray and γ-ray (1-3000 keV) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope (HE). The main detector plane of HE comprises 18 NaI(Tl)/CsI(Na) phoswich detectors, where NaI(Tl) is used as the primary detector to measure ~ 20–250 keV photons incident from the field of view (FOV) defined by collimators, and CsI(Na) is used as the active shielding detector to NaI(Tl) by pulse shape discrimination. Additionally, CsI(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV, i.e. 1.1°×5.7° (15 units), 5.7°×5.7° (2 units), and blocked (1 unit). Therefore, the combined FOV of HE is approximately 5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 keV. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the dead-time is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20–250 keV band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 MeV band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments. [ABSTRACT FROM AUTHOR]

As the fourth most essential nutrient element, sulfur plays an important role in plant growth and development, but limited information is available regarding sulfur and its bioavailability after the restoration of degraded wetlands. A field experiment was conducted on three different mixed-vegetation types and planting densities to investigate the effects of vegetation type and density on sulfur and arylsulfatase in mangrove surface soils at the Jinjiang estuary in China. The total sulfur (TS), H2O-S, absorbed-S, available sulfur (AS) and arylsulfatase contents in soils 2 and 3 years after restoration were measured, and the sulfur availability index (SAI) was calculated. The results indicated that vegetation type and planting density significantly affected the TS and bioavailability of soil sulfur, and higher TS, H2O-S, absorbed-S, AS and arylsulfatase contents appeared at LQT 1.0 × 1.0 m (1918 mg/kg, 137 mg/kg, 387 mg/kg, 960 mg/kg and 38 μg*g−1*h−1, respectively). Furthermore, the bioavailability of sulfur increased after restoration from the second to third year. Arylsulfatase was significantly correlated with AS (p < 0.05) and highly correlated with soil organic matter (SOM) (p < 0.01), but no significant correlations were observed among arylsulfatase, SOM and TS. No sulfur fertilizer was required for mangrove plants during restoration in this study area. [ABSTRACT FROM AUTHOR]

Purpose: Non-medical use of prescription opioids, especially among adolescents, has been substantially increased in recent years. However, the neuromechanism remains largely unexplored. In the present study, we aimed to investigate the brain metabolic changes in adolescent rats following chronic escalating morphine administration using positron emission tomography (PET).Procedures: 2-Deoxy-2-[18F]Fluoro-D-glucose ([18F]FDG) microPET imaging was performed, and statistical parametric mapping (SPM) was used for image analysis. Glucose transporter 3 (Glut-3), dopamine D2 receptor (D2R), and Mμ-opioid receptor (μ-OR) were used for immunostaining analysis.Results: Cerebral glucose metabolism was increased in the corpus callosum (CC) and right retrosplenial dysgranular cortex (rRSD), while it was decreased in the right ventral pallidum (rVP). The expressions of Glut-3, D2R, and μ-OR were increased in CC and rRSD, while they were decreased in rVP. Furthermore, glucose metabolism and Glut-3 expression were positively correlated with the expressions of D2R or μ-OR in CC, rRSD, and rVP.Conclusions: [18F]FDG microPET brain imaging study in combination with immunohistological investigation revealed that CC, rRSD, and rVP were specifically involved in opioid dependence in adolescents. Our findings provided valuable insights into the neuromechanism of adolescent addiction of prescription opioids and might have important implications for the development of prevention and intervention approaches. [ABSTRACT FROM AUTHOR]