Two‐dimensional (2D) materials are highly sensitive to substrates, interfaces, and the surrounding environments. Suspended 2D materials are free from substrate‐induced effects, thus an ideal approach ...to study their intrinsic properties. However, it is very challenging to prepare large‐area suspended 2D materials with high efficiency. Here we report a universal method, based on pretreatments of densely patterned hole array substrates with either oxygen‐plasma or gold film deposition, to prepare large‐area suspended mono‐ and few‐layer 2D materials. Multiple structural, optical, and electrical characterization tools were used to fully evaluate the improved performance of various suspended 2D layers. Some of these observations reported in this study are: (1) Observation of a new Raman low frequency mode for the suspended MoS2; (2) Significantly stronger photoluminescence (PL) and second harmonic generation (SHG) signals of suspended WSe2, which enables the study of new optical transition processes; (3) The low energy electron diffraction pattern on suspended MoS2 also exhibits much sharper spots than that on the supported area; and (4) The mobility of suspended graphene device approaches 300 000 cm2 V−1 s−1, which is desirable to explore the intrinsic properties of graphene. This work provides an innovative and efficient route for fabricating suspended 2D materials, and we expect that it can be broadly used for studying intrinsic properties of 2D materials and in applications of hybrid active nanophotonic and electronic devices.
A new efficient method to fabricate high‐quality and large‐area suspended two‐dimensional (2D) materials is developed. The superior properties of suspended samples over supported ones are proved by Raman spectra, photoluminescence spectra, second harmonic generation, low energy electron microscopy as well as mobility characterization. This work could facilitate the studies of the intrinsic properties of 2D materials and the applications of active 2D nano devices.
Ampelopsideae J. Wen & Z.L. Nie is a small-sized tribe of Vitaceae Juss., including ca. 47 species from four genera showing a disjunct distribution worldwide across all the continents except ...Antarctica. There are numerous species from the tribe that are commonly used as medicinal plants with immune-modulating, antimicrobial, and anti-hypertensive properties. The tribe is usually recognized into three clades, i.e., Ampelopsis Michx., Nekemias Raf., and the Southern Hemisphere clade. However, the relationships of the three clades differ greatly between the nuclear and the plastid topologies. There has been limited exploration of the chloroplast phylogenetic relationships within Ampelopsideae, and studies on the chloroplast genome structure of this tribe are only available for a few individuals. In this study, we aimed to investigate the evolutionary characteristics of plastid genomes of the tribe, including their genome structure and evolutionary insights.
We sequenced, assembled, and annotated plastid genomes of 36 species from the tribe and related taxa in the family. Three main clades were recognized within Ampelopsideae, corresponding to Ampelopsis, Nekemias, and the Southern Hemisphere lineage, respectively, and all with 100% bootstrap supports. The genome sequences and content of the tribe are highly conserved. However, comparative analyses suggested that the plastomes of Nekemias demonstrate a contraction in the large single copy region and an expansion in the inverted repeat region, and possess a high number of forward and palindromic repeat sequences distinct from both Ampelopsis and the Southern Hemisphere taxa.
Our results highlighted plastome variations in genome length, expansion or contraction of the inverted repeat region, codon usage bias, and repeat sequences, are corresponding to the three lineages of the tribe, which probably faced with different environmental selection pressures and evolutionary history. This study provides valuable insights into understanding the evolutionary patterns of plastid genomes within the Ampelopsideae of Vitaceae.
Transcriptional intermediary factor 1 gamma (TIF1γ) may play either a potential tumor‐suppressor or ‐promoter role in cancer. Here we report on a critical role of TIF1γ in the progression of ...hepatocellular carcinoma (HCC). Reduced expression of TIF1γ was detected in HCC, especially in advanced HCC tissues, compared to adjacent noncancerous tissues. HCC patients with low TIF1γ expression had shorter overall survival times and higher recurrence rates than those with high TIF1γ expression. Reduced TIF1γ expression was an independent and significant risk factor for recurrence and survival after curative resection. In HCC cells, TIF1γ played a dual role: It promoted tumor growth in early‐stage HCC, but not in advanced‐stage HCC, whereas it inhibited invasion and metastasis in both early‐ and advanced‐stage HCC. Mechanistically, we confirmed that TIF1γ inhibited transforming growth factor‐β/ Drosophila mothers against decapentaplegic protein (TGF‐β/Smad) signaling through monoubiquitination of Smad4 and suppressed the formation of Smad2/3/4 complex in HCC cells. TGF‐β‐inducing cytostasis and metastasis were both inhibited by TIF1γ in HCC. We further proved that TIF1γ suppressed cyotstasis‐related TGF‐β/Smad downstream c‐myc down‐regulation, as well as p21/cip1 and p15/ink4b up‐regulation in early‐stage HCC. Meanwhile, TGF‐β inducible epithelial‐mesenchymal transition and TGF‐β/Smad downstream metastatic cascades, including phosphatase and tensin homolog deleted on chromosome ten down‐regulation, chemokine (CXC motif) receptor 4 and matrix metalloproteinase 1 induction, and epidermal growth factor receptor– and protein kinase B–signaling transactivation, were inhibited by TIF1γ. In addition, we found that the down‐regulation of TIF1γ in HCC was caused by hypermethylation of CpG islands in the TIF1γ promoter, and demonstrated that the combination of TIF1γ and phosphorylated Smad2 was a more powerful predictor of poor prognosis. Conclusion: TIF1γ regulates tumor growth and metastasis through inhibition of TGF‐β/Smad signaling and may serve as a novel prognostic biomarker in HCC. (Hepatology 2014;60:1620–1636)
Panax notoginseng is a medicinally important Chinese herb with a long history of cultivation and clinical application. The planting area is mainly distributed in Wenshan Prefecture, where the quality ...and safety of P. notoginseng have been threatened by high concentration of arsenic (As) from the soil. The roles of phosphate (Pi) transporters involved in Pi acquisition and arsenate (AsV) tolerance were still unclear in this species.
In this study, two open reading frames (ORFs) of PnPht1;1 and PnPht1;2 separated from P. notoginseng were cloned based on RNA-seq, which encoded 527 and 541 amino acids, respectively. The results of relative expression levels showed that both genes responded to the Pi deficiency or As exposure, and were highly upregulated. Heterologous expression in Saccharomyces cerevisiae MB192 revealed that PnPht1;1 and PnPht1;2 performed optimally in complementing the yeast Pi-transport defect, particularly in PnPht1;2. Cells expressing PnPht1;2 had a stronger AsV tolerance than PnPht1;1-expressing cells, and accumulated less As in cells under a high-Pi concentration. Combining with the result of plasma membrane localization, these data confirmed that transporters PnPht1;1 and PnPht1;2 were putative high-affinity H
/H
PO
symporters, mediating the uptake of Pi and AsV.
PnPht1;1 and PnPht1;2 encoded functional plasma membrane-localized transporter proteins that mediated a putative high-affinity Pi/H
symport activity. Expression of PnPht1;1 or PnPht1;2 in mutant strains could enhance the uptake of Pi and AsV, that is probably responsible for the As accumulation in the roots of P. notoginseng.
In this letter, we propose a novel Non-Line-of-Sight (NLOS) identification and error-mitigation method for dynamic object positioning and ultra-wideband (UWB) ranging. By utilizing inverse estimation ...on known Anchor Points (APs) and improved robust unscented Kalman filter (IRUKF), while fusing Gyroscope and Accelerometer data, the proposed technology identifies and compensates for NLOS occlusions between tag and APs, reducing positioning errors. The approach has been verified through simulation and experiment, with identification precision of 97.02%. After mitigating errors, substantial error reductions of 91.80% and 98.90% were observed in LOS and NLOS situations, respectively. Moreover, the developed IRUKF effectively minimizes mislocalization by 50.48% in harsh scenarios.
Typically, in the manufacturing of GH4169 superalloy forgings, the multi-process hot forming that consists of pre-deformation, heat treatment and final deformation is required. This study focuses on ...the microstructural evolution throughout hot working processes. Considering that δ phase can promote nucleation and limit the growth of grains, a process route was designed, including pre-deformation, aging treatment (AT) to precipitate sufficient δ phases, high temperature holding (HTH) to uniformly heat the forging, and final deformation. The results show that the uneven strain distribution after pre-deformation has a significant impact on the subsequent refinement of the grain microstructure due to the complex coupling relationship between the evolution of the δ phase and recrystallization behavior. After the final deformation, the fine-grain microstructure with short rod-like δ phases as boundaries is easy to form in the region with a large strain of the pre-forging. However, necklace-like mixed grain microstructure is formed in the region with a small strain of the pre-forging. In addition, when the microstructure before final deformation consists of mixed grains, dynamic recrystallization (DRX) nucleation behavior preferentially depends on kernel average misorientation (KAM) values. A large KAM can promote the formation of DRX nuclei. When the KAM values are close, a smaller average grain size of mixed-grain microstructure is more conductive to promote the DRX nucleation. Finally, the interaction mechanisms between δ phase and DRX nucleation are revealed.
Endothelial cells (ECs) and bone marrow stromal cells (BMSCs) play crucial roles in supporting hematopoiesis and hematopoietic regeneration. However, whether ECs are a source of BMSCs remains ...unclear. Here, we evaluate the contribution of endothelial-to-mesenchymal transition to BMSC generation in postnatal mice. Single-cell RNA sequencing identifies ECs expressing BMSC markers Prrx1 and Lepr; however, this could not be validated using Prrx1-Cre and Lepr-Cre transgenic mice. Additionally, only a minority of BMSCs are marked by EC lineage tracing models using Cdh5-rtTA-tetO-Cre or Tek-CreERT2. Moreover, Cdh5
BMSCs and Tek
BMSCs show distinct spatial distributions and characteristic mesenchymal markers, suggestive of their origination from different progenitors rather than CDH5
TEK
ECs. Furthermore, myeloablation induced by 5-fluorouracil treatment does not increase Cdh5
BMSCs. Our findings indicate that ECs hardly convert to BMSCs during homeostasis and myeloablation-induced hematopoietic regeneration, highlighting the importance of using appropriate genetic models and conducting careful data interpretation in studies concerning endothelial-to-mesenchymal transition.
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•Bimetallic HZSM-5 was used to catalyze pine pyrolysis assisted with calcium formate.•MAHs production was promoted and PAHs formation was inhibited remarkably.•The maximum MAHs yield ...was 12.79 wt% with Mg-Mo co-modified HZSM-5.•Mg-Mo co-modified HZSM-5 possessed better anti-deactivation performance than HZSM-5.
An efficient process was developed to selectively produce monocyclic aromatic hydrocarbons (MAHs) from ex-situ catalytic fast pyrolysis (CFP) of pine assisted with calcium formate (CF) over bimetal-modified HZSM-5. Mo and another metal (Mg, Ga or Zn) were used to modify the HZSM-5, and the as-synthesized bimetal-modified HZSM-5 catalysts were utilized for both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale CFP tests with CF as a hydrogen donor to selectively obtain MAHs. The results revealed that the presence of CF and Mg-Mo modified HZSM-5 (0.5Mg1Mo/HZ) exhibited excellent capability for MAHs production with tiny generation of polycyclic aromatic hydrocarbons (PAHs). The maximum MAHs yield attained 12.79 wt% at 650 °C from Py-GC/MS with the CF-to-pine (CF-to-PN) ratio of 3 and catalyst-to-pine (CA-to-PN) ratio of 11, and became 9.67 wt% from lab-scale device with CF-to-PN and CA-to-PN ratios of 0.5 and 4, respectively. In addition, compared with HZSM-5, 0.5Mg1Mo/HZ possessed better anti-deactivation ability.
Coxsackievirus A5 (CV-A5) is a re-emerging enterovirus that causes hand, foot, and mouth disease in children under five years of age. CV-A5-M14-611 is a mouse-adapted strain that can infect orally ...and lead to the death of 14-day-old mice. Here, recombinants based on CV-A5-M14-611 were constructed carrying three reporter genes in different lengths. Smaller fluorescent marker proteins, light, oxygen, voltage sensing (iLOV), and nano luciferase (Nluc) were proven to be able to express efficiently in vitro. However, the recombinant with the largest insertion of the red fluorescence protein gene (DsRed) was not rescued. The construction strategy of reporter viruses was to insert the foreign genes between the C-terminus of VP1 and the N-terminus of 2A genes and to add a 2A protease cleavage domain at both ends of the insertions. The iLOV-tagged or Nluc-tagged recombinants, CV-A5-iLOV or CV-A5-Nluc, exhibited a high capacity for viral replication, genetic stability in cells and pathogenicity in mice. They were used to establish a rapid, inexpensive and convenient neutralizing antibody assay and greatly facilitated virus neutralizing antibody titration. Living imaging was performed on mice with CV-A5-Nluc, which exhibited specific bioluminescence in virus-disseminated organs, while fluorescence induced by CV-A5-iLOV was weakly detected. The reporter-gene-tagged CV-A5 can be used to study the infection and mechanisms of CV-A5 pathogenicity in a mouse model. They can also be used to establish rapid and sensitive assays for detecting neutralizing antibodies.
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