The Majorana fermion, which is its own antiparticle and obeys non-Abelian statistics, plays a critical role in topological quantum computing. It can be realized as a bound state at zero energy, ...called a Majorana zero mode (MZM), in the vortex core of a topological superconductor, or at the ends of a nanowire when both superconductivity and strong spin orbital coupling are present. A MZM can be detected as a zero-bias conductance peak (ZBCP) in tunneling spectroscopy. However, in practice, clean and robust MZMs have not been realized in the vortices of a superconductor because of contamination from impurity states or other closely packed Caroli–de Gennes-Matricon (CdGM) states, which hampers further manipulations of MZMs. Here, using scanning tunneling spectroscopy, we show that a ZBCP well separated from the other discrete CdGM states exists ubiquitously in the cores of free vortices in the defect-free regions of(Li0.84Fe0.16)OHFeSe, which has a superconducting transition temperature of 42 K. Moreover, a Dirac-cone-type surface state is observed by angle-resolved photoemission spectroscopy, and its topological nature is confirmed by band calculations. The observed ZBCP can naturally be attributed to a MZM arising from the chiral topological surface state of a bulk superconductor. Thus,(Li0.84Fe0.16)OHFeSeprovides an ideal platform for studying MZMs and topological quantum computing.
The role of surgery compared with reirradiation in the primary treatment of patients with resectable, locally recurrent nasopharyngeal carcinoma (NPC) who have previously received radiotherapy is a ...matter of debate. In this trial, we compared the efficacy and safety outcomes of salvage endoscopic surgery versus intensity-modulated radiotherapy (IMRT) in patients with resectable locally recurrent NPC.
This multicentre, open-label, randomised, controlled, phase 3 trial was done in three hospitals in southern China. We included patients aged 18–70 years with a Karnofsky Performance Status score of at least 70 who were histopathologically diagnosed with undifferentiated or differentiated, non-keratinising, locally recurrent NPC with tumours confined to the nasopharyngeal cavity, the post-naris or nasal septum, the superficial parapharyngeal space, or the base wall of the sphenoid sinus. Eligible patients were randomly assigned (1:1) to receive either endoscopic nasopharyngectomy (ENPG group) or IMRT (IMRT group). Randomisation was done manually using a computer-generated random number code and patients were stratified by treatment centre. Treatment group assignment was not masked. The primary endpoint was overall survival, compared between the groups at 3 years. Efficacy analyses were done by intention to treat. Safety analysis was done in patients who received treatment according to the treatment they actually received. This trial was prospectively registered at the Chinese Clinical Trial Registry, ChiCTR-TRC-11001573, and is currently in follow-up.
Between Sept 30, 2011, and Jan 16, 2017, 200 eligible patients were randomly assigned to receive either ENPG (n=100) or IMRT (n=100). At a median follow-up of 56·0 months (IQR 42·0–69·0), 74 patients had died (29 29% of 100 patients in the ENPG group and 45 45% of 100 patients in the IMRT group). The 3-year overall survival was 85·8% (95% CI 78·9–92·7) in the ENPG group and 68·0% (58·6–77·4) in the IMRT group (hazard ratio 0·47, 95% CI 0·29–0·76; p=0·0015). The most common grade 3 or worse radiation-related late adverse event was pharyngeal mucositis (in five 5% of 99 patients who underwent ENPG and 26 26% of 101 patients who underwent IMRT). Five 5% of the 99 patients who underwent ENPG and 20 20% of the 101 patients who underwent IMRT died due to late toxic effects specific to radiotherapy; attribution to previous radiotherapy or trial radiotherapy is unclear due to the long-term nature of radiation-related toxicity.
Endoscopic surgery significantly improved overall survival compared with IMRT in patients with resectable locally recurrent NPC. These results suggest that ENPG could be considered as the standard treatment option for this patient population, although long-term follow-up is needed to further determine the efficacy and toxicity of this strategy.
Sun Yat-sen University Clinical Research 5010 Program
Autophagy participates in the progression of hepatocellular carcinoma (HCC) and the resistance of HCC cells to sorafenib. We investigated the feasibility of sensitising HCC cells to sorafenib by ...modulating miR-541-initiated microRNA-autophagy axis.
Gain- and loss-of-function assays were performed to evaluate the effects of miR-541 on the malignant properties and autophagy of human HCC cells. Autophagy was quantified by western blotting of LC3, transmission electron microscopy analyses and confocal microscopy scanning of mRFP-GFP-LC3 reporter construct. Luciferase reporter assays were conducted to confirm the targets of miR-541. HCC xenograft tumours were established to analyse the role of miR-541 in sorafenib-induced lethality.
The expression of miR-541 was downregulated in human HCC tissues and was associated with malignant clinicopathologic phenotypes, recurrence and survival of patients with HCC. miR-541 inhibited the growth, metastasis and autophagy of HCC cells both in vitro and in vivo. Prediction software and luciferase reporter assays identified autophagy-related gene 2A (ATG2A) and Ras-related protein Rab-1B (RAB1B) as the direct targets of miR-541. Consistent with the effects of the miR-541 mimic, inhibition of ATG2A or RAB1B suppressed the malignant phenotypes and autophagy of HCC cells. Furthermore, siATG2A and siRAB1B partially reversed the enhancement of the malignant properties and autophagy in HCC cells mediated by the miR-541 inhibitor. More interestingly, higher miR-541 expression predicted a better response to sorafenib treatment, and the combination of miR-541 and sorafenib further suppressed the growth of HCC cells in vivo compared with the single treatment.
Dysregulation of miR-541-ATG2A/RAB1B axis plays a critical role in patients' responses to sorafenib treatment. Manipulation of this axis might benefit survival of patients with HCC, especially in the context of the highly pursued strategies to eliminate drug resistance.
We present optical and near-infrared stellar polarization observations toward the dark filamentary clouds associated with IC5146. The data allow us to investigate the dust properties (this paper) and ...the magnetic field structure (Paper II). A total of 2022 background stars were detected in the Rc, , H, and/or K bands to mag. The ratio of the polarization percentage at different wavelengths provides an estimate of , the wavelength of the peak polarization, which is an indicator of the small-size cutoff of the grain size distribution. The grain size distribution seems to significantly change at mag, where both the average and dispersion of decrease. In addition, we found m for mag, which is larger than the ∼0.55 m in the general interstellar medium (ISM), suggesting that grain growth has already started in low-AV regions. Our data also reveal that polarization efficiency ( ) decreases with AV as a power law in the Rc, , and K bands with indices of −0.71 0.10, −1.23 0.10, and −0.53 0.09. However, H-band data show a power index change; the PE varies with AV steeply (index of −0.95 0.30) when mag, but softly (index of −0.25 0.06) for greater AV values. The soft decay of PE in high-AV regions is consistent with the radiative alignment torque model, suggesting that our data trace the magnetic field to mag. Furthermore, the breakpoint found in the H band is similar to that for AV, where we found the dispersion significantly decreased. Therefore, the flat PE-AV in high-AV regions implies that the power-index changes result from additional grain growth.
The IC 5146 cloud is a nearby star-forming region in Cygnus, consisting of molecular gas filaments in a variety of evolutionary stages. We used optical and near-infrared polarization data toward the ...IC 5146 cloud, reported in the first paper of this series, to reveal the magnetic fields in this cloud. Using the newly released Gaia data, we found that the IC 5146 cloud may contain two separate clouds: a first cloud, including the densest main filament at a distance of ∼600 pc, and a second cloud, associated with the Cocoon Nebula at a distance of ∼800 pc. The spatially averaged H-band polarization map revealed a well-ordered magnetic field morphology, with the polarization segments perpendicular to the main filament but parallel to the nearby subfilaments, consistent with models assuming that the magnetic field is regulating cloud evolution. We estimated the magnetic field strength using the Davis-Chandrasekhar-Fermi method and found that the magnetic field strength scales with volume density with a power-law index of ∼0.5 in the density range from to 3000 cm−3, which indicates an anisotropic cloud contraction with a preferred direction along the magnetic field. In addition, the mass-to-flux ratio of the cloud gradually changes from subcritical to supercritical from the cloud envelope to the deep regions. These features are consistent with strong magnetic field star formation models and suggest that the magnetic field is important in regulating the evolution of the IC 5146 cloud.
Abstract
We present spatial and kinematic correlation between the young stellar population and the cloud clumps in the Ophiuchus star-forming region. The stellar sample consists of known young ...objects at various evolutionary stages, taken from the literature, some of which are diagnosed with Gaia EDR3 parallax and proper-motion measurements. The molecular gas is traced by the 850
μ
m Submillimetre Common-User Bolometer Array-2 image, reaching ∼2.3 mJy beam
−1
, the deepest so far for the region, stacked from the James Clerk Maxwell Telescope/Transient program aiming to detect submillimeter outburst events. Our analysis indicates that the more evolved sources, namely the class II and III young stars, are located further away from clouds than class I and flat-spectrum sources that have ample circumstellar matter and are closely associated with natal clouds. Particularly the class II and III population is found to exhibit a structured spatial distribution indicative of passage of shock fronts from the nearby Sco–Cen OB association thereby compressing clouds to trigger star formation, with the latest starbirth episode occurring now in the densest cloud filaments. The young stars at all evolutionary stages share similar kinematics. This suggests that the stellar patterns trace the relics of parental cloud filaments that now have been dispersed.
Conversion of levulinic acid to valuable chemicals: a review Xu, Wen‐Ping; Chen, Xue‐Fang; Guo, Hai‐Jun ...
Journal of chemical technology and biotechnology (1986),
November 2021, 2021-11-00, 20211101, Letnik:
96, Številka:
11
Journal Article
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•This study estimated aboveground and net aboveground biomass on sparse shrub communities with large surface fluctuations.•This study provides the most suitable RGB algorithm for ...calculating vegetation coverage in sandy areas.•The relationship between vegetation coverage and aboveground biomass of shrub communities in Mu Us sandy land was study.studied.
Accurate detection of vegetation cover and biomass of shrub communities in sandy area is beneficial for evaluating ecosystem, improving remote sensing models, and assessing the accuracy of remote sensing. Unmanned aerial vehicles (UAVs) have replaced traditional measurement methods in biomass and fraction of vegetation coverage (FVC) detection owing to the high spatial resolution of their imagery, their high positioning accuracy, and their ease of use. The existing methods of detecting biomass via UAVs, however, are not suitable for surface fluctuations, dwarf shrubs, and herbs. Futhermore, the method of calculating FVC using UAV RGB images has not yet been tested in sandy areas. To accurately extract FVC data, aboveground biomass (ABS) and net aboveground biomass (NABS) of shrub communities in the desert regions, UAV RGB images of 87 sample plots in the Mu Us sandy land were collected and used to obtain the FVC and biomass information via the object-based classification method, single shrub canopy biomass model and vegetation index-based method. The results are as follows: (1) the method of calculating ABS and NABS based on shrub canopy width extraction can be used in desert shrub communities, and results show that the ABS and NABS of vegetation communities increases from 15 to 800 g/m2 and 10–250 g/m2, respectively, in the Mu Us sandy land; and (2) the lowest value of ABS (NABS) appeared in the mobile sandy dunes and the highest value appeared in the semi-fixed sandy dunes; (3) under fixed thresholds conditions, the FVC can be extracted accurately using the excess green method, visible atmospherically resistant index, vegetative index, green red vegetation index and red green blue vegetation index (RGBVI); and (4) the correlation between the FVC calculated by the five RGB vegetation indexes and NABS in this study is greater than that between FVC and ABS (e.g. R2NABS - RGBVI = 0.734, R2ABS - RGBVI = 0.666), and the FVC calculated by RGBVI can be used to estimate NABS in the Mu Us sandy land. This study will provide new insights for field investigations of the ABS, NABS, and FVC in sandy areas.
Acute kidney injury (AKI) is a common clinical problem, characterized by a sudden loss of renal function, a high risk of death, and the eventual development of renal fibrosis and renal failure. ...Cordyceps cicadae is a traditional Chinese medicine with the potential function of kidney protection. We analyze two sputum extracts, a water extract (WCC), and an ethanol extract (ECC), to assess the potential of treating AKI in an animal model of kidney injury induced by cisplatin. A nephrotoxic mouse model was first established by intraperitoneal injection of cisplatin. Subsequently, WCC and ECC were orally administered in these mice. The results show that WCC and ECC significantly alleviated cisplatin-induced AKI renal histological changes, serum creatinine (CRE) and blood urea nitrogen (BUN) production, and the levels of NO, TNF-α, IL-1β, and IL-6. The levels of malondialdehyde (MDA) and glutathione (GSH) were suppressed by administration of WCC and ECC. However, WCC treatment prevented these changes significantly better than ECC treatment. In addition, Western blot data showed that WCC attenuated the cisplatin-induced protein expression of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS), as well as inhibiting nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) activation in the kidney tissues. Furthermore, WCC greatly inhibited the expression of Toll-like receptor 4 (TLR4) and cisplatin-induced NF-κB activation, as well as dramatically increasing the production of antioxidative enzymes (i.e., superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1)), silent information regulator T1 (Sirt1), and p-AMP-activated protein kinase (AMPK) in the kidney tissues. In addition, we found that WCC increased the expression levels of the autophagy-related proteins LC3B and Beclin-1; proapoptotic proteins, including cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP) 1; and organic anion transporters 1 (OAT1) and 3 (OAT3) in the kidney tissues. Finally, WCC, ECC, and two bioactive compounds—adenosine and N6-(2-hydroxyethyl) adenosine (HEA)—inhibited the production of nitrite oxide (NO) and intracellular reactive oxygen species (ROS) triggered by lipopolysaccharide- (LPS-) stimulated RAW264.7 macrophages in vitro. Collectively, WCC could provide a potential therapeutic candidate for the prevention of cisplatin-induced kidney injury through the inhibition of oxidative stress and inflammation.
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