Objective
This study was performed to examine serum microRNA-375 (miR-375) expression in patients with osteosarcoma and determine its diagnostic and prognostic value.
Methods
Serum samples were ...obtained from 95 patients with osteosarcoma and 95 healthy individuals. miR-375 expression was detected by real-time polymerase chain reaction. The associations of serum miR-375 expression with the patients’ clinicopathological characteristics and prognosis were then evaluated. Receiver operating characteristic curve analysis was performed to obtain the potential value of serum miR-375 as a biomarker for osteosarcoma diagnosis and chemosensitivity prediction.
Results
Serum miR-375 expression was significantly lower in patients with osteosarcoma than in healthy individuals. Low serum miR-375 levels were associated with advanced clinical stages, large tumor size, positive distant metastasis, and poor tumor response to preoperative chemotherapy. Receiver operating characteristic curve analysis illustrated that serum miR-375 could distinguish patients with osteosarcoma from healthy individuals and distinguish patients with a good pathologic response from those with a poor response. Multivariate analysis confirmed low serum miR-375 expression as a statistically significant independent unfavorable prognostic factor.
Conclusions
Serum miR-375 expression was downregulated in patients with osteosarcoma and might serve as a biomarker for its diagnosis, prognosis, and chemosensitivity prediction.
To solve the problem that it is difficult to extract the weak fault features of rolling bearing effectively under the interference of strong background noise，a method of extracting the weak fault ...features based on the combination of maximum second-order cyclostationary blind deconvolution （CYCBD） and envelope spectrum is proposed.Firstly，a reasonable cycle frequency set is set by the fault characteristic frequency，and CYCBD is used to reduce the noise of weak fault impulse signal with strong noise，so as to enhance the periodic impulse component in the signal.Then，the noise reduction signal is analyzed by Hilbert envelope spectrum to identify the fault characteristic frequency.The simulation and experimental results show that the method can effectively extract the weak fault features submerged by strong noise.
The heterogeneity and complexity of malaria involves political and natural environments, socioeconomic development, cross-border movement, and vector biology; factors that cannot be changed in a ...short time. This study aimed to assess the impact of economic growth and cross-border movement, toward elimination of malaria in Yunnan Province during its pre-elimination phase. Malaria data during 2011-2016 were extracted from 18 counties of Yunnan and from 7 villages, 11 displaced person camps of the Kachin Special Region II of Myanmar. Data of per-capita gross domestic product (GDP) were obtained from Yunnan Bureau of Statistics. Data were analyzed and mapped to determine spatiotemporal heterogeneity at county and village levels. There were a total 2,117 malaria cases with 85.2% imported cases; most imported cases came from Myanmar (78.5%). Along the demarcation line, malaria incidence rates in villages/camps in Myanmar were significantly higher than those of the neighboring villages in China. The spatial and temporal trends suggested that increasing per-capita GDP may have an indirect effect on the reduction of malaria cases when observed at macro level; however, malaria persists owing to complex, multi-faceted factors including poverty at individual level and cross-border movement of the workforce. In moving toward malaria elimination, despite economic growth, cooperative efforts with neighboring countries are critical to interrupt local transmission and prevent reintroduction of malaria via imported cases. Cross-border workers should be educated in preventive measures through effective behavior change communication, and investment is needed in active surveillance systems and novel diagnostic and treatment services during the elimination phase.
We explore both experimentally and theoretically the conductance and packing of molecular junctions based on oligo(phenyleneethynylene) (OPE) diamine wires, when a series of functional groups are ...incorporated into the wires. Using the scanning tunnelling microscopy break-junction (STM BJ) technique, we study these compounds in two environments (air and 1,2,4-trichlorobenzene) and explore different starting molecular concentrations. We show that the electrical conductance of the molecular junctions exhibits variations among different compounds, which are significant at standard concentrations but become unimportant when working at a low enough concentration. This shows that the main effect of the functional groups is to affect the packing of the molecular wires, rather than to modify their electrical properties. Our theoretical calculations consistently predict no significant changes in the conductance of the wires due to the electronic structure of the functional groups, although their ability to hinder ring rotations within the OPE backbone can lead to higher conductances at higher packing densities.
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IJS, KILJ, NUK, PNG, UL, UM
This paper studies the effect of trade policy uncertainty on firm‐level export volatility. Using data on Chinese exporters around China's WTO accession, we find that a reduction of trade policy ...uncertainty between China and the United States decreases the volatility of firm‐level export to the United States and increases the volatility of export to the rest of the world. In the aggregate firm level, this shock in trade policy uncertainty has no significant effect on the volatility of total export or the volatility of total sales. Our finding suggests a risk‐sharing effect among export destinations.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, ODKLJ, OILJ, PILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The wire‐like properties of four S‐(4‐{2‐4‐(2‐phenylethynyl)phenylethynyl}phenyl) thioacetate derivatives, PhC≡CC6H4C≡CC6H4SAc (1), H2NC6H4C≡CC6H4C≡CC6H4SAc (2), PhC≡CC6H2(OMe)2C≡CC6H4SAc (3) and ...AcSC6H4C≡CC6H4C≡CC6H4SAc (4) (Figure 1), all of which possess a high degree of conjugation along the oligo(phenyleneethynylene) (OPE) backbone, were investigated as self‐assembled monolayers (SAMs) on gold and platinum electrodes by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The redox probe Fe(CN)64− was used in both the CV and impedance experiments. The results indicate that the thiolates derived from thioacetate‐protected precursor molecules 1 and 2 form well‐ordered monolayers on a gold electrode, whereas SAMs derived from 3 and 4 exhibit randomly distributed pinholes. The electron tunnelling resistance and fractional coverage of SAMs of all four compounds were examined using electron tunnelling theory. The analysis of the results reveal that the well‐ordered SAMs of 1 and 2 exhibit higher charge‐transfer resistance in comparison to the defect‐ridden SAMs of 3 and 4. The additional steric bulk offered by the methoxy groups in 3 is likely to prevent efficient packing within the SAM, leading to a microelectrode behaviour, when assembled on a gold electrode surface. The protected dithiol derivative 4 probably binds to the surface through both terminal groups which prevents dense packing and leads to the formation of a monolayer with randomly distributed pinholes. Atomic force microscopy (AFM) was used to examine the morphology of the monolayers, and height images gave root‐mean‐square (RMS) roughness′s which are in agreement with the proposed SAM structures.
Monolayers of thiol‐terminated rigid rod wire‐like oligo(phenyleneethynylene)s assembled on electrodes show charge‐transfer properties which are dependent on their structure and terminal group.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Under the ongoing COVID-19 prevention and control measures in China, increasing the laboratory severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid testing capacity has become ...the top priority. Since the COVID-19 outbreak in Xinfadi market in Beijing in June 2020, large-scale screening of key populations has been carried out, challenging the nucleic acid testing capabilities of hospital laboratories. Therefore, within 48 hours, Peking University People's Hospital (PKUPH) transformed a non-nucleic acid testing laboratory into a SARS-CoV-2 nucleic acid testing laboratory. Based on the original structure of the building, we adapted measures to local conditions, sorted out a new testing process, and quickly started testing for COVID-19. The nucleic acid testing process has been optimized, including quality control, personal operating specifications, and the timeliness of the release of LIS results to form closed-loop management. This high-throughput COVID-19 testing optimization process provides a reference model for other countries that are fighting the epidemic.
The electrochemical CO2 reduction (ECDRR), as a key reaction in artificial photosynthesis to implement renewable energy conversion/storage, has been inhibited by the low efficiency and high costs of ...the electrocatalysts. Herein, we synthesize a fluorine‐doped carbon (FC) catalyst by pyrolyzing commercial BP 2000 with a fluorine source, enabling a highly selective CO2‐to‐CO conversion with a maximum Faradaic efficiency of 90 % at a low overpotential of 510 mV and a small Tafel slope of 81 mV dec−1, outcompeting current metal‐free catalysts. Moreover, the higher partial current density of CO and lower partial current density of H2 on FC relative to pristine carbon suggest an enhanced inherent activity towards ECDRR as well as a suppressed hydrogen evolution by fluorine doping. Fluorine doping activates the neighbor carbon atoms and facilitates the stabilization of the key intermediate COOH* on the fluorine‐doped carbon material, which are also blocked for competing hydrogen evolution, resulting in superior CO2‐to‐CO conversion.
Fluorine‐doped carbon synthesized by facile pyrolysis shows a 90 % CO Faradaic efficiency at 490 mV overpotential and a 81 mV dec−1 Tafel slope. Fluorine doping activates neighboring carbon atoms for stronger bonding adsorbed COOH* and suppresses the evolution of hydrogen. Enhanced solar‐driven neutral CO2 splitting is observed.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In vivo adhesions between cells and the extracellular matrix play a crucial role in cell differentiation, proliferation, and migration as well as tissue remodeling. Natural three-dimensional (3D) ...matrices, such as self-assembling matrices and Matrigel, have limitations in terms of their biomechanical properties. Here, we present a simple method to produce an acellular human amniotic matrix (AHAM) with preserved biomechanical properties and a favorable adhesion potential. On the stromal side of the AHAM, human foreskin fibroblasts (HFFs) attached and extended with bipolar spindle-shaped morphology proliferated to multilayer networks, invaded into the AHAM, and migrated in a straight line. Moreover, αV integrin, paxillin, and fibronectin were observed to colocalize after 24 h of HFF culture on the stromal side of the AHAM. Our results indicate that the AHAM may be an ideal candidate as a cell-matrix adhesion substrate to study cell adhesion and invasion as well as other functions in vitro under a tensile force that mimics the in vivo environment.
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DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
This paper develops a theoretical model to describe how exporting firms manage their inventory stocks in response to an exogenous trade policy uncertainty shock. Using firm‐level data from China ...Industrial Enterprise Database and China Customs Database on inventory and exports over the period around China's WTO accession, we show that a reduction in trade policy uncertainty significantly increased exporting firms' inventory holdings. The result was robust to various robustness checks. This effect was found to be stronger for private and foreign firms than state‐owned enterprises and mainly driven by firms from the coastal region. We also found that the reduction in trade policy uncertainty increased the frequency and the average volume of export transactions, and that this was the mechanism behind the effect. This paper helps to understand exporting firms' optimal inventory problem arising from trade‐policy uncertainty and shocks.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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