Application of Midline Catheter in Patients with Oral Cavity Malignancies during Perioperative Period

Objective: The study aims to compare the application value of midline catheter and indwelling needle in patients with oral cavity malignancies during perioperative period. Methods: 146 patients with oral cavity malignancies admitted to our hospital from January 2019 to July 2021 were selected as the research subjects. 73 patients treated with midline catheters during the treatment were the experimental group, and another 73 patients were treated with indwelling needles as the control group. The indwelling time, total number of puncturing times, and incidence of adverse reactions of two catheterization methods were compared between the two groups. Meanwhile, each patient was investigated for treatment satisfaction. Result: The indwelling time was significantly longer in the experimental group than in the control group (P < 0.0001), and the total number of puncturing times in the experimental group was significantly lower than that in the control group (P < 0.0001). The incidence of adverse reactions in the experimental group (χ2 = 4.960, P = 0.0259) was significantly lower than that in the control group in terms of catheter occlusion (χ2 = 12.56, P = 0.0004), catheter detachment (χ2 = 8.46, P = 0.0036), drug extravasation (χ2 = 3.27, P = 0.0011), phlebitis (χ2 = 3.62, P = 0.0003), and bleeding from the puncture point (χ2 = 14.98, P = 0.0001). The satisfaction rate (χ2 = 33.45, P < 0.0001) and fundamental satisfaction rate (χ2 = 16.57, P < 0.0001) in the experimental group were significantly higher than those in the control group, while the dissatisfaction rate was significantly lower than that in the control group (χ2 = 11.38, P = 0.0007). The difference is statistically significant. Conclusion: Compared with indwelling needle, the application of midline catheters in patients with oral cavity malignancies during perioperative period can effectively reduce the number of puncturing times and the incidence of catheter-related adverse reactions, with a high satisfaction rate, which is worthy of clinical promotion and application.

Facile Fabrication of Conductive Paper-based Materials from Tunicate Cellulose Nanocrystals and Polydopamine-decorated Graphene Oxide

Conductive papers made from graphene and its derivatives are important for the development of electronic devices; however, elastomerbased matrices usually make it difficult for the conductive sheets to form continuous conductive networks. In this work, we used tunicate-derived cellulose nanocrystals(TCNC) instead of traditional elastomers as the matrix for polydopamine(PDA)-coated and reduced graphene oxide(GO) to prepare conductive paper, which, at a low concentration, were better for the formation of conductive networks from conductive sheets. It was found that the Young's modulus of the conductive paper produced via this strategy reached as high as 7 GPa. Meanwhile, owing to the partial reduction of GO during the polymerization of dopamine, the conductivity of the conductive paper reached as high as 1.3×10-5 S/cm when the PDA-coated GO content was 1 wt%, which was much higher than the conductivity of pure GO(～4.60×10-8 S/cm). This work provides a new strategy for preparing environmentally friendly conductive papers with good mechanical properties and low conductive filler content, which may be used to produce high-performance, low-cost electronic devices.

Recent advances of defect-induced spin and valley polarized states in graphene

Electrons in graphene have fourfold spin and valley degeneracies owing to the unique bipartite honeycomb lattice and an extremely weak spin-orbit coupling,which can support a series of broken symmetry states.Atomic-scale defects in graphene are expected to lift these degenerate degrees of freedom at the nanoscale,and hence,lead to rich quantum states,highlighting promising directions for spintronics and valleytronics.In this article,we mainly review the recent scanning tunneling microscopy(STM)advances on the spin and/or valley polarized states induced by an individual atomicscale defect in graphene,including a single-carbon vacancy,a nitrogen-atom dopant,and a hydrogen-atom chemisorption.Lastly,we give a perspective in this field.

Colossal structural distortion and interlayer-coupling suppression in a van der Waals crystal induced by atomic vacancies

The interlayer coupling in van der Waals(vdW)crystals has substantial effects on the performance of materials.However,an indepth understanding of the microscopic mechanism on the defect-modulated interlayer coupling is often elusive,owing partly to the challenge of atomic-scale characterization.Here we report the native Se-vacancies in a charge-density-wave metal 2HNbSe2,as well as their influence on the local atomic configurations and interlayer coupling.Our low-temperature scanning tunneling microscopy(STM)measurements,complemented by density functional theory calculations,indicate that the Sevacancies in few-layer NbSe2 can generate obvious atomic distortions due to the Jahn-Teller effect,thus breaking the rotational symmetry on the nanoscale.Moreover,these vacancies can locally generate an in-gap state in single-layer NbSe2,and more importantly,lead to a colossal suppression of interlayer coupling in the bilayer system.Our results provide clear structural and electronic fingerprints around the vacancies in vdW crystals,paving the way for developing functional vdW devices.

社交媒体使用提高学习绩效还是降低学习绩效?

在当今互联网时代,使用社交媒体已成为每个人学习、生活的一部分,社交媒体对学习绩效的影响正成为一个不可忽视的因素。然而,以往对社交媒体使用与学习绩效之间关系的研究结论仍存在一定分歧。为了探讨社交媒体使用能否提高学习绩效,本研究运用元分析方法考察了社交媒体使用对学习绩效的影响以及使用情境和研究方法的调节效应。基于对2011—2018年国际英文期刊35项实证研究的元分析,结果表明:社交媒体使用与学习绩效存在中等程度的正相关(ES=0.49);使用情境的调节效应检验发现,社交媒体类型、使用群体、应用平台和学科领域对社交媒体使用与学习绩效的关系具有调节作用;研究方法的调节效应检验发现,测量模型、数据属性和学习绩效指标对社交媒体使用与学习绩效的关系同样具有调节作用。

Washed microbiota transplantation vs.manual fecal microbiota transplantation:clinical findings,animal studies and in vitro screening

Fecal microbiota transplantation(FMT)by manual preparation has been applied to treat diseases for thousands of years.However,this method still endures safety risks and challenges the psychological endurance and acceptance of doctors,patients and donors.Population evidence showed the washed microbiota preparation with microfiltration based on an automatic purification system followed by repeated centrifugation plus suspension for three times significantly reduced FMT-related adverse events.This washing preparation makes delivering a precise dose of the enriched microbiota feasible,instead of using the weight of stool.Intraperitoneal injection in mice with the fecal microbiota supernatant obtained after repeated centrifugation plus suspension for three times induced less toxic reaction than that by the first centrifugation following the microfiltration.The toxic reactions that include death,the change in the level of peripheral white blood cells,and the proliferation of germinal center in secondary lymphoid follicles in spleen were noted.The metagenomic next-generation sequencing(NGS)indicated the increasing types and amount of viruses could be washed out during the washing process.Metabolomics analysis indicated metabolites with pro-inflammatory effects in the fecal microbiota supernatant such as leukotriene B4,corticosterone,and prostaglandin G2 could be removed by repeated washing.Near-infrared absorption spectroscopy could be served as a rapid detection method to control the quality of the washingprocess.In conclusion,this study for the first time provides evidence linking clinical findings and animal experiments to support that washed microbiota transplantation(WMT)is safer,more precise and more quality-controllable than the crude FMT by manual.

Research Advances of Ferroelectric Semiconductors of 2D Hybrid Perovskites toward Photoelectronic Applications

Ferroelectric materials, characterized by the switchable spontaneous polarization(Ps) through reversing the directions of external electric field, exhibit versatile physical attributes that have been extensively used for practical device applications. Two-dimensional(2D) organic-inorganic hybrid perovskites are recently emerging as a robust family of candidate ferroelectrics, termed ferroelectric semiconductors. In particular, the coexistence and/or coupling of ferroelectric polarization with their semiconducting properties enables new physical concepts, thus providing a potential platform for the development of new multifunctional optoelectronic devices. This review primarily describes the structural origin of symmetry breaking for generating ferroelectric orders in 2D hybrid perovskites, and then presents the combination of ferroelectric Ps with other semiconducting optoelectronic activities. Regarding the emergence of new photoelectric behaviors, the prospects for this 2D family of ferroelectric semiconductors are further discussed, along with their development tendency for the future photoelectronic device applications.

Dual-enzyme-propelled unbounded DNA walking nanomachine for intracellular imaging of lowly expressed microRNA

Despite the progress on the analysis of miRNA either in vitro or in vivo,intracellular imaging of lowly expressed microRNA remains a challenge.Here we develop a novel dual-enzyme-propelled DNA walking nanomachine,which is tailored to accomplish this mission.The nanomachine is constructed with nanoparticles-loaded DNA tracks,on which the targeted miRNA working as a single-foot DNA walker can move autonomously under the catalysis of two cooperative enzymes.Cleavage of the DNA tracks like a "burnt-bridge" mechanism is thereafter triggered,resulting in an amplified fluorescent signal.After the comprehensive study and optimization of the DNA nanomachine,miR-892b,a significantly down-regulated miRNA in breast cancer cells,is selected as a model target.Sensitivity detection in vitro is achieved with a superior detection limit of 4 pM.While being delivered into cells,the DNA nanomachine is available for the imaging of the lowly expressed microRNA,which is totally missing using the conventional fluorescence in situ hybridization (FISH) method.Up-regulation or down-regulation of the miRNA by exogenous regulatory factors can be also well evaluated.This DNA nanomachine provides a competitive approach for the analysis of miRNA,and has the potential to be extended to some other biomolecules.

An imported human case with the SARS-CoV-2 Omicron subvariant BA.2.75 in Yunnan Province,China

The Omicron variants spread rapidly worldwide after being initially detected in South Africa in November 2021.It showed increased transmissibility and immune evasion with far more amino acid mutations in the spike(S)protein than the previously circulating variants of concern(VOCs).Notably,on 15 July 2022,we monitored the first VOC/Omicron subvariant BA.2.75 in China from an imported case.Moreover,nowadays,this subvariant still is predominant in India.It has nine additional mutations in the S protein compared to BA.2,three of which(W152R,G446S,and R493Q reversion)might contribute to higher transmissibility and immune escape.This subvariant could cause wider spread and pose a threat to the global situation.Our timely reporting and continuous genomic analysis are essential to fully elucidate the characteristics of the subvariant BA.2.75 in the future.