Typical Modification Research Articles

Identification of Six N7-Methylguanosine-Related miRNA Signatures to Predict the Overall Survival and Immune Landscape of Triple-Negative Breast Cancer through In Silico Analysis.

Triple-negative breast cancer (TNBC) is a widely prevalent breast cancer, with a mortality rate of up to 25%. TNBC has a lower survival rate, and the significance of N7-methylguanosine (m7G) modification in TNBC remains unclear. Thus, this study is aimed at investigating m7G-related miRNAs in TNBC patients through in silico analysis. In our research, RNA sequencing and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. The miRNAs targeting typical m7G modification regulators Methyltransferase-like 1 (METTL1) and WD repeat domain 4 (WDR4) were predicted on the TargetScan website. A miRNA risk model was built, and its prognostic value was evaluated by R soft packages. Single-sample gene set enrichment analysis was used to assess immune infiltration, and further expression of immune checkpoints was investigated. As a result, miR-421, miR-5001-3p, miR-4326, miR-1915-3p, miR-3177-5p, and miR-4505 were identified to create the risk model. A nomogram consisting of the stage N and risk model predicted overall survival effectively among TNBC patients. Treg and TIL were shown to be strongly linked to the risk model, and the high-risk group had higher levels of four immune checkpoints expression (CD28, CTLA-4, ICOS, and TNFRSF9). A risk model consisting of m7G-related miRNAs was constructed. The findings of the current study could be used as a prognostic biomarker and can provide a novel immunotherapy insight for TNBC patients.

Polyacrylic acid ultra‐thin films: Influence of cross‐linking structure via hyperthermal hydrogen‐induced cross‐linking

AbstractThe facile technology of hyperthermal hydrogen‐induced cross‐linking (HHIC) has recently been employed to efficiently cross‐link the typical surface modification material of poly acrylic acid (PAA) on polymer substrates, such as polylactic acid substrates, parylene C substrates and hydrophobic polypropylene substrates. This paper systematically studied the HHIC induced self‐cross‐linking of PAA without polymer substrates. It was found that the H was cleaved not only from the CH, but also from the surface functional group COOH, evidenced by both X‐ray photoelectron spectroscopy (XPS) measurement and the water contact angle test. We explained the self‐cross‐linking process as a result of both CC bonding and COOC bonding. Meanwhile, it was also found that PAA on different substrates can also be cross‐linked by secondary electron generated by X‐ray radiation during XPS analysis, which could be the main reason for wide variations of different reported XPS results.

Recent Advances of Doping and Surface Modifying Carbon Nitride with Characterization Techniques

As a non-metallic organic semiconductor photocatalyst, graphitic carbon nitride (g–C3N4, CN) has become a research hotspot due to its excellent performance in organic degradation, CO2 reduction and water splitting to produce hydrogen. However, the high recombination rate of electron-hole pairs, low specific surface area and weak light absorption of bulk CN synthesized by the traditional one-step thermal polymerization method seriously restrict its photocatalytic performance and practical application. To enhance the photocatalytic performance of CN, doping and surface modification strategies are usually employed to tune the band gap of carbon nitride and improve the separation of carriers. In this paper, the research progress of different methods to modify CN in recent years is introduced, and the mechanisms of improving the photocatalytic performance are mainly analyzed. Typical modification methods are mainly divided into metal doping, non-metal doping, co-doping and surface-functionalized modification. Some characterization methods that can analyze the doping state and surface modification are also discussed as examples. Finally, the difficulties that need to be addressed through modified CN photocatalysts and the directions for future research are pointed out.

Developing fine-tuned metal–organic frameworks for photocatalytic treatment of wastewater: A review

The environmental pollution is still one of the most serious problems facing mankind today, it is of great significance to develop novel wastewater treatment processes. Photocatalysis is regarded as one of the most promising techniques for wastewater treatment. Lately, there is a strong increase in the number of reports on the synthesis and applications of MOF-based photocatalysts. In this review, the typical modification strategies of MOFs for improving photocatalytic activities are summarized, such as optimization of preparation method, surface modification, doping metal ions, loading quantum dots as well as constructing the heterojunction. The main purposes of these modification strategies are to broaden the light absorption range of MOFs and increase the separation efficiency of photogenerated electron-hole pairs. Advantages and disadvantages of each modification strategy are also analyzed. Meanwhile, the applications of MOFs-based photocatalyst in wastewater treatment are briefly discussed, including reduction of metal ions, degradation of organic pollutants and inactivation of bacteria. More importantly, the challenges and outlooks about MOFs-based photocatalyst are proposed. In short, it is hoped that this review can provide some meaningful references for designing MOFs-based photocatalyst in future research.

Analysis of glycan ratio of Chinese hamster ovary cell-cetuximab antigen-binding segment via rapid enzyme digestion with endo-β-N-acetylglucosaminidase F

西妥昔单抗具有较复杂的糖基化修饰,在抗原结合片段(Fab)和可结晶片段(Fc)的重链上都含有2个N-糖基化位点,其中Fab段的糖基化最为复杂,要研究清楚该位点的糖基化修饰,开发专一性切糖技术和稳定的聚糖比例分析方法是当前迫切需要解决的难题。以中国仓鼠卵巢(CHO)细胞表达的西妥昔单抗为研究对象,使用β-N-乙酰氨基葡萄糖苷酶(Endo F2)开发了一种快速Fab段聚糖释放的方法,利用超高效液相色谱-高分辨质谱(UPLC-HRMS)进行了定性和聚糖比例分析。第一步对抗体原液进行非变性酶切,抗体原液经超纯水稀释后,加入糖苷酶Endo F2进行酶切,通过质谱对质量数的解析,结果表明Endo F2酶切时间5 min, Fab段的聚糖就能完全切除,而Fc段的聚糖不受影响,实现了快速酶切,而且切糖具有很好的专一性。第二步对Fab段聚糖进行比例分析,将释放的聚糖经对氨基苯甲酰胺(2-AB)荧光标记后使用超高效液相色谱联用荧光检测器(FLR)进行检测,在亲水作用色谱(HILIC)柱上得到良好的分离并可以进行稳定地聚糖比例分析。3次独立试验结果表明,酶切后的质谱图基本一致,且聚糖的比例结果也基本一致,表明Endo F2酶切方法和聚糖比例分析方法都具有较好的稳定性和可靠性。此外,通过测定来自两个不同工艺生产的样品,数据显示两者的糖谱上具有非常明显的差异,表明利用开发的方法可以实现对抗体生产工艺进行监测研究,对抗体生产工艺的评估具有非常重要的意义。

Nano-electrocrystals in pharmaceutical drug delivery

In this review that explained applications of nano-electrocrystals as a drug delivery., Nanocrystals that are used to deliver medicinal drugs have gained importance in recent decades as a result of the development in nanomedicine where the resulting vesicle, which has a watery core surrounded by a hydrophobic membrane, can be loaded with a variety of hydrophobic or hydrophilic molecules for therapeutic purposes. Liposomes are usually synthesized with naturally occurring phospholipids, mainly phosphatidylcholine. Cholesterol is often included in the preparation to adjust film stiffness and increase its stability. The molecular load is induced by formation of liposomes in aqueous solution, solvent exchange mechanisms, or pH gradient methods. Different molecules can also be chemically coupled to the surface of the liposome to alter the recognition properties. One typical modification is the coupling of polyethylene glycol (PEG) to the vesicle surface. The hydrophilic polymer prevents identification by macrophages and reduces filtration. Size, surface charge, and bilayer fluidity also alter the conduction kinetics of liposomes. The liposomes diffuse from the bloodstream into the interstitial space near the target site. Since the cell membrane itself is composed of phospholipids, liposomes can fuse directly with the membrane and release the charge into the cytosol, or they may enter the cell through phagocytosis or other active transport pathways.

Transcriptome-wide profiling of N 6-methyladenosine via a selective chemical labeling method.

Studies of chemical modifications on RNA have ushered in the field of epitranscriptomics. N 6-Methyladenosine (m6A) is the most typical RNA modification and is indispensable for basic biological processes. This study presents a chemical pulldown method (m6A-ORL-Seq) for transcriptome-wide profiling of m6A. Moreover, chemical labeling results in a specific reverse transcription (RT) truncation signature. This study has identified four thousand high-confidence m6A sites at single-base resolution in the human transcriptome. Unlike previously reported methods based on m6A-antibody or m6A-sensitive enzymes, the antibody/enzyme-free chemical method provides a new perspective for single-base m6A detection at the transcriptome level.

Transformation of Selected Fusarium Toxins and Their Masked Forms during Malting of Various Cultivars of Wheat.

This study investigated the impact of malting of six wheat cultivars inoculated with Fusarium culmorum on the dynamics of content changes of selected Fusarium toxins. The grains of all the tested cultivars showed a high content of deoxynivalenol (DON), zearalenone (ZEN), and their derivatives, whereas nivalenol (NIV) and its glucoside were found only in the Legenda cultivar. Our experiments confirmed that the malting process of wheat grain enables the secondary growth of Fusarium, and mycotoxin biosynthesis. The levels of toxins in malt were few-fold higher than those in grain; an especially high increase was noted in the case of ZEN and its sulfate as the optimal temperature and pH conditions for the biosynthesis of these toxins by the pathogen are similar to those used in the grain malting process. This is the first paper reporting that during the malting process, biosynthesis of ZEN sulfate occurs, instead of glycosylation, which is a typical modification of mycotoxins by plant detoxication enzymes.

High-Temperature Surface Oxide Growth Kinetics of Al–Si–Zr Bulk Alloys and Ribbons

A typical modification technique of the functional properties of Al–Si based alloys is the addition of some third element in trace level. In the present work, ternary Al–Si–Zr bulk and ribbon alloys have been prepared. The kinetics of high-temperature surface oxidation has been studied by thermogravimetric method. It was found that at the start of the experiment the chemical reaction velocity is rate-controlling while for longer times the (oxygen) diffusion is the rate-controlling process. Activation energy of the two stages of oxidation has been obtained. Additional studies such as thermochemical analysis, optical and electron microscopy, and microhardness tests have been done.

Demonstrating Apparently Inconspicuous but Sensitive Impacts on the Rollover Failure of Lithium-Ion Batteries at a High Voltage.

Layered oxides, such as Li[Ni0.5Co0.2Mn0.3]O2 (NCM523), are promising cathode materials for operation at a high voltage, i.e., high-energy lithium-ion batteries. The instability-reasoned transition metal dissolution remains a major challenge, which initiates electrode cross-talk, alteration of the solid electrolyte interphase, and enhanced Li-metal dendrite formation at the graphite anode, consequently leading to rollover failure. In this work, relevant impacts on this failure mechanism are highlighted. For example, a conventional coating of NCM523 with aluminum oxide as a typical high-voltage modification improves kinetic aspects but can only postpone the rollover failure to later charge/discharge cycles. Interestingly, a similar effect on the rollover failure is observed merely after modification of the cell formation protocol, i.e., the first cycles. Further influences of specific test protocols are highlighted and show that the rollover failure even disappears at C-rates above 2C, which can be attributed to a more homogeneous distribution of Li-metal dendrite formation. It is worth noting that a variation of anode porosity can reveal similar effects, as, e.g., variations in anode processing also impact Li dendrite distribution and the appearance of rollover failure. Overall, the rollover failure is a valid but complex phenomenon, which sensitively depends on apparently inconspicuous parameters and should not be disregarded.

Polyurethane-based polymer electrolytes for lithium Batteries: Advances and perspectives

Polymer electrolytes (PEs) have been widely regarded as an effective approach to eliminate most of the potential safety hazards encountered in traditional liquid electrolytes for lithium batteries (LBs). Substantial research efforts have been devoted to exploiting excellent performance PE systems, including poly(ethylene oxide) (PEO), polyurethane (PU), polysiloxane (PS), polyvinylidene fluoride (PVDF) and polycarbonate (PC)-based PEs. Among them, PU-based PEs have attracted increasing interests due to their flexibility of structure manipulation, excellent mechanical strength, facile modification, high thermal and electrochemical stability. However, to date, separated and detailed reviews on the progress of PU-based PEs are rarely reported. In this review, we comprehensively summarize the key progress on PU-based PEs from the perspective of flexible structure design strategies, basic electrochemical/mechanical properties, typical modification methods, specific functions, and their potential applications in LBs. Furthermore, synthesis routes of PUs and perspectives of PU-based PEs are also discussed. It is believed that this review will be of great guiding significance for exploiting high performance PU-based PEs for next-generation LBs.

LSTMCNNsucc: A Bidirectional LSTM and CNN-Based Deep Learning Method for Predicting Lysine Succinylation Sites.

Lysine succinylation is a typical protein post-translational modification and plays a crucial role of regulation in the cellular process. Identifying succinylation sites is fundamental to explore its functions. Although many computational methods were developed to deal with this challenge, few considered semantic relationship between residues. We combined long short-term memory (LSTM) and convolutional neural network (CNN) into a deep learning method for predicting succinylation site. The proposed method obtained a Matthews correlation coefficient of 0.2508 on the independent test, outperforming state of the art methods. We also performed the enrichment analysis of succinylation proteins. The results showed that functions of succinylation were conserved across species but differed to a certain extent with species. On basis of the proposed method, we developed a user-friendly web server for predicting succinylation sites.

Efficient and Stable Perovskite Solar Cells Using Bathocuproine Bilateral-Modified Perovskite Layers.

Surface modification engineering is an effective method to improve the crystallinity and passivate the perovskite interface and grain boundary, which can improve the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). The typical interface modification method is usually introduced at the interface of the perovskite/hole transport layer (HTL) or perovskite/electron transport layer (ETL) through coordination of the groups in the material with the perovskite. In this work, the n-type semiconductor bathocuproine (BCP) including the pyridine nitrogen bond was modified at the interfaces of perovskite/HTL or perovskite/ETL to improve perovskite crystallinity and interface contact properties. The better crystallinity and superior interface contact properties are obtained using BCP unilateral modification, which obviously increases the PCEs of PSCs. The BCP bilateral modification at both perovskite/ETL and perovskite/HTL interfaces can further improve the crystallinity with fewer defects and superior contact properties, which show the largest Voc (1.14 V) and fill factors (FF 77.1%) compared to PSCs with BCP unilateral modification. PSCs with BCP bilateral modification obtained 20.6% PCEs, which is greatly higher than that (17.5%) of the original PSCs. The stability of PSCs with BCP bilateral modification can be greatly improved due to the better crystal quality and hydrophobic property of the interfaces. The results demonstrated that the n-type BCP material can efficiently modify both perovskite/HTL and perovskite/ETL interfaces beyond its semiconductor type, which can greatly improve the PCEs and stability of PSCs because BCP modification can passivate interfaces, improve interface contact and hydrophobic properties, promote crystallinity of the perovskite layer with fewer defects, and block carrier recombination at both interfaces.

Review of Functional Treatments for Modified Wood

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.

An HEVC steganalytic approach against motion vector modification using local optimality in candidate list

Abstract Current research of video steganalysis is mainly oriented to H.264 or even earlier formats. As the H.265/HEVC standard is becoming more and more popular, there have been steganographic methods specifically designed for HEVC videos. Previous steganalytic methods are no longer effective due to the new features of HEVC. The advanced motion vector prediction technique employed by HEVC provides a new way for motion vector (MV) modification, utilizing the index of the candidate MV list. Such modification cannot be detected by previous steganalytic methods because the value of MV is not changed. To solve this problem, we proposed a new steganalytic strategy employing not only the local optimality of MV but also the local optimality in the candidate list. Combining the two types of local optimality, a 40-dimensional feature set is designed. Extensive experiments are carried out to evaluate the effectiveness of the proposed feature set. It is shown that compared with three current steganalyzers, our approach improves the performance against typical MV modification methods under various settings. In particular, our approach significantly boosts the detection accuracy of the index modification method that is exclusive to HEVC videos. To our best knowledge, this is the first work of video steganalytic method exploiting the new features of HEVC format.

Triboelectric Nanogenerators: Advances in Nanostructures for High‐Performance Triboelectric Nanogenerators (Adv. Mater. Technol. 3/2021)

In article number 2000916, Jun Chen and co-workers present a systematic review on recent approaches utilized to modify triboelectric surfaces with nanostructure patterns for advanced triboelectric nanogenerators (TENGs). As a typical physical modification strategy for TENGs, micro-/nano-arrays can increase the output voltage and current of TENGs significantly through increasing the contact area of the paired triboelectric surfaces.

Nucleolar rDNA folds into condensed foci with a specific combination of epigenetic marks

Arabidopsis thaliana 45S ribosomal genes (rDNA) are located in tandem arrays called nucleolus organizing regions on the termini of chromosomes 2 and 4 (NOR2 and NOR4) and encode rRNA, a crucial structural element of the ribosome. The current model of rDNA organization suggests that inactive rRNA genes accumulate in the condensed chromocenters in the nucleus and at the nucleolar periphery, while the nucleolus delineates active genes. We challenge the perspective that all intranucleolar rDNA is active by showing that a subset of nucleolar rDNA assembles into condensed foci marked by H3.1 and H3.3 histones that also contain the repressive H3K9me2 histone mark. By using plant lines containing a low number of rDNA copies, we further found that the condensed foci relate to the folding of rDNA, which appears to be a common mechanism of rDNA regulation inside the nucleolus. The H3K9me2 histone mark found in condensed foci represents a typical modification of bulk inactive rDNA, as we show by genome-wide approaches, similar to the H2A.W histone variant. The euchromatin histone marks H3K27me3 and H3K4me3, in contrast, do not colocalize with nucleolar foci and their overall levels in the nucleolus are very low. We further demonstrate that the rDNA promoter is an important regulatory region of the rDNA, where the distribution of histone variants and histone modifications are modulated in response to rDNA activity.

A self-healing coating based on facile pH-responsive nanocontainers for corrosion protection of magnesium alloy

• Mesoporous silica core@layered double hydroxide shell nanocontainers were obtained. • The preparation process is facile, low cost and environmentally-friendly. • The acidic-responsive feature of the nanocontainers was demonstrated. • The corrosion protection of nanocontainers-embedded coating is enhanced remarkably. • The corrosion protection mechanism of nanocontainers-embedded coating is proposed. The preparation of pH-responsive nanocontainers by typical silane modification of the mesoporous silica nanoparticle (MSN) surface is usually high-cost, complex, and time-consuming, which remains a great challenge for effective corrosion protection of magnesium alloy. Here, a new strategy to construct pH-responsive nanocontainers (MSN-MBT@LDH) is demonstrated. The nanocontainers consist of corrosion inhibitor (2-mercaptobenzothiazole, MBT) loaded MSN core and layered double hydroxide (LDH) nanosheet shell serving as gatekeepers. The successful loading of MBT and encapsulation by LDH nanosheets were confirmed by a series of characterization such as scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (STEM-EDS) and N 2 adsorption/desorption isotherms. The pH-responsive feature of the nanocontainers was demonstrated by determination of the MBT concentration in buffer solutions with different pH values. A smart corrosion protection system on Mg alloy is obtained by incorporating the synthesized nanocontainers into a self-assembled nanophase particle (SNAP) coating. The electrochemical tests and visual observations show that the hybrid coating has the best barrier properties and robustness in corrosion protection in NaCl corrosive solutions in comparison with the control coatings. The present method simplifies the synthesis processes of nanocontainers and eliminates the potential detrimental effect of excess gatekeepers on the coating. The findings provide new insights into the preparation of scalable nanocontainers. The self-healing coatings are expected to have widespread applications for corrosion protection of Mg alloy and other metals.

First-principles study of structural, electronic and magnetic properties of A-site-ordered quadruple perovskite LaMn3Rh4O12

The introduction of magnetic ions at A-site is a typical modification in traditional ABO3 perovskite materials to achieve the target physical properties. Here, the impact of Mn3+ incorporation on the magnetic coupling and electronic structures of A-site-ordered quadruple perovskite LaMn3Rh4O12 was investigated using spin-polarized first-principles calculations. Our calculations demonstrate that LaMn3Rh4O12 is antiferromagnetic with G-type antiferromagnetic coupling within Mn sublattice and nonmagnetic Rh, which is quite different from the diamagnetic host perovskite LaRhO3. The electronic structure analyses reveal that the formal oxidation state of B-site Rh is +3 with 4d6 electronic configuration and it splits into t2g and eg orbitals (t2g6eg0) in low-spin state, indicating that Rh has no contribution to the magnetic properties and the introduced Mn3+ at the A′-site drives the ordered antiparallel spins coupling. Moreover, LaMn3Rh4O12 exhibits semiconducting behavior and the chemical valence is La3+Mn3+3Rh3+4O2-12. Our study provides an alternative method for beneficial modification of traditional ABO3 perovskites by introducing A-site magnetic ions.

An anomalous foveal OCT-sign after posterior capsule rupture in cataract surgery: Complicated cataract surgery maculopathy.

To report a series of novel optical coherence tomography (SD-OCT) foveal abnormalities, that we called "T-sign," that were noticed after a complicated cataract surgery with posterior capsule rupture and vitreous loss. Retrospective case series of persistent foveal changes that incurred after anteroposterior vitreo-foveal traction secondary to phacoemulsification in presence of posterior capsule rupture. The study included three eyes of three patients that incurred in complicated cataract surgery and intraoperative vitreo-foveal traction. During 8-month follow-up period peculiar abnormalities in fundus examination and in OCT scans were reported in all cases. Phacoemulsification in presence of posterior capsule rupture could induce a vitreo-foveal strain that could be transmitted to the cone outer segment tips (COST line) and inner-outer segment (IS/OS) junction. This focal stress is liable for "T-sign," a persistent SD-OCT abnormality that induce a visual impairment and a slight metamorphopsia in the fixation point. All over the world, more than 9.5 million cataract surgeries are completed each year.1 During surgery, many intraoperative complications could occur, and capsule rupture with vitreous loss is a frequent event. Phacoemulsification in presence of a wide posterior capsule rupture and vitreo-macular adhesion could induce a typical modification of the foveal structure and a permanent visual impairment.