Search

Background: Tongue squamous cell carcinoma (TSCC) is one of the most widespread cancers in oral cancer, but the current treatment outcome for TSCC is unsatisfactory. Apigenin has been shown to have antitumor effects in various tumors. However, the potential role of Apigenin (API) in TSCC has not been proven yet. Methods: The effects of API on the proliferation and migration ability of SCC-9 cells were measured by CCK8 assay and wound-healing assay. RNA-seq was executed to ensure differentially expressed genes (DEGs) in SCC-9 cells after API treatment. Then, combined with the gene expression data and relevant individual information of TSCC samples acquired from The Cancer Genome Atlas (TCGA), an API-related model was built through Lasso regression and multivariate Cox regression. Receiver operating characteristic (ROC) curve and a nomogram and calibration curve were created to forecast patient outcomes to improve the clinical suitability of the API-related signature. The relationships between the two risk groups and function enrichment, immune infiltration characteristics, and drug susceptibility were analyzed. Furthermore, RNA-seq was performed to verify the expression of API-related genes in SCC-9 cells. Results: We demonstrated that API could weaken the malignant behavior of SCC-9 cells and availably established the 7-API-related gene model to forecast the prognosis of TSCC patients, which was performed to divide TSCC patients into different risk groups, with risk scores working as an independent factor for participating TSCC related death. Besides, we confirmed that the model could be applied to assess prognostic status, tumor immune cell infiltration, and drug susceptibility. Moreover, TSCC cells treated with API, compared to the control group, have higher levels of TMEM213 and GPR158, and lower levels of CASP14 and ITGA5. Conclusions: Our research suggested the inhibition effect of API on TSCC cells and provided a substantial foundation for the next study into the links between API-related genes and related functions in TSCC patients.

Background: The standard treatment for advanced unresectable non-small cell lung cancer (NSCLC) is concurrent chemoradiotherapy. However, many poor Karnofsky score or elderly patients cannot tolerate it due to heir serious side effects. For patients who cannot tolerate concurrent chemoradiotherapy, conventional treatment is sequential chemoradiotherapy or radiotherapy alone. But the median survival time of sequential chemoradiotherapy and radiotherapy alone is 11-16 months. In order to improve curative effect, radiotherapy, as an important treatment method, has been tried, innovated and improved continuously. The goal of this trial is to evaluate feasibility and safety of isotoxic hypofractionated radiotherapy in patients with NSCLC. Methods: This is a phase Ⅱ open-label multi-center two-step non-randomised Trial. In the first stage, 12 patients will be included in the trial with radiotherapy of 3Gy per fraction. If more than 3 patients have serious side effects of radiotherapy, the trial will be terminated. Otherwise, the second phase will continue, and the total number of participants will be 30. All patients eventually will be followed up for 5 years. The primary endpoint is the safety of isotoxic hypofractionated radiotherapy. The secondary outcomes are time to progression (TTP), progression free survival (PFS), overall survival (OS), local control (LC). Discussion: In clinical practice, the local control rate of conventional fractionated radiotherapy for NSCLC is very low. We hope that this trial can verify the safety of isotoxic hypofractionated radiotherapy. Trial Registration: NCT03606291, REGISTERED JULY, 30, 2018.

Covalent DNA–protein cross-links are toxic DNA lesions that interfere with essential biological processes, which can cause serious biological consequences, such as genomic instability and protein misexpression. 5-Formyluracil (5fU) as an important modification in DNA, which is mainly from oxidative damage, exists in a variety of cells and tissues. We have reported that 5fU mediated DNA–protein conjugates could exist in human cells [Zhou et al. CCS Chem. 2 (2020) 54–63]. We now aimed to explore its potential biological effects in vitro and in vivo. In this paper, we firstly reported that 5fU intermediated DNA–peptide or DNA–protein conjugates (both were called DPCs) could inhibit different polymerases bypass or cause mutations. Then we further investigated the functional impacts caused by 5fU-mediated DPCs, which appeared in different gene expression components [in the promoter sequence or 5′-untranslated regions (UTR)]. These results together may contribute to a broader understanding of DNA–protein interactions as well as the biological functions associated with 5fU.

Natural chemical modifications of nucleic acids play a vital role in life processes. Compared to other epigenetic modifications, there are multiple ways to quantify the methylated derivatives of cytosine. However, simple and convenient methods for detecting and quantifying thymine derivatives are scarce because they are found in tiny quantities in biological systems. Additionally, exploring easy ways to detect these derivatives can also throw light on their biological significance. This manuscript reports a novel strategy to quantify 5-formyluracil (5fU) and 5-hydroxymethyluracil (5hmU). Differences between modified and unmodified bases are accumulated and amplified by arranging phi29 DNA polymerase to repeat through a circular template labeled thymidine. In combination with real-time quantitative rolling circle amplification (RCA), low-abundance thymine oxides can be quantified precisely. The global levels of 5fU and 5hmU were analyzed in different biological samples, using only 40 ng of sample input on a laboratory real-time PCR instrument. The reported strategy was executed hassle-free and, in principle, can be extended to design methods for detecting other epigenetic modifications in nucleotides that are rare in biological systems.

5-Formyluracil (5fU) is a vital DNA marker that is widely distributed in the cells of organisms. A unique feature of 5fU is the possession of a potentially reactive aldehyde group in its structure ...

The rapid discovery of two-dimensional (2D) van der Waals (vdW) quantum materials has led to heterostructures that integrate diverse quantum functionalities such as topological phases, magnetism, and superconductivity. In this context, the epitaxial synthesis of vdW heterostructures with well-controlled interfaces is an attractive route towards wafer-scale platforms for systematically exploring fundamental properties and fashioning proof-of-concept devices. Here, we use molecular beam epitaxy to synthesize a vdW heterostructure that interfaces two material systems of contemporary interest: a 2D ferromagnet (1T-CrTe

Albeit with low content, 5-formyluracil has been an important modification in genomic DNA. 5-formyluracil was found to be widely distributed among living bodies. Due to the equilibrium of keto-enol form, 5-formyluracil could be base-paired with guanine, thus inducing mutations in DNA. The highly reactive aldehyde group of 5-formyluracil could also cross-link with proteins nearby, preventing gene replication and expression. In certain cancerous tissues, the content of 5-formyluracil was found to be higher than the normal tissues adjacent to the tumor, and 5-formyluracil might be an important potential epigenetic mark. Nevertheless, the lack of a higher resolution sequencing technique has hampered the studies of 5-formyluracil. We adjusted the base-pairing of 5-formyluracil during the PCR amplification by changing the pH. Hence, we adopted the Alkaline Modulated 5-formyluracil Sequencing (AMfU-Seq), a single-base resolution analysis method, to profile 5-formyluracil at the genome scale. We analyzed the distribution of 5-formyluracil in the human thyroid carcinoma cells using AMfU-Seq. This technique can be used in the future investigations of 5-formyluracil.

The crystal symmetry of a material dictates the type of topological band structures it may host, and therefore symmetry is the guiding principle to find topological materials. Here we introduce an alternative guiding principle, which we call 'quasi-symmetry'. This is the situation where a Hamiltonian has an exact symmetry at lower-order that is broken by higher-order perturbation terms. This enforces finite but parametrically small gaps at some low-symmetry points in momentum space. Untethered from the restraints of symmetry, quasi-symmetries eliminate the need for fine-tuning as they enforce that sources of large Berry curvature will occur at arbitrary chemical potentials. We demonstrate that a quasi-symmetry in the semi-metal CoSi stabilizes gaps below 2 meV over a large near-degenerate plane that can be measured in the quantum oscillation spectrum. The application of in-plane strain breaks the crystal symmetry and gaps the degenerate point, observable by new magnetic breakdown orbits. The quasi-symmetry, however, does not depend on spatial symmetries and hence transmission remains fully coherent. These results demonstrate a class of topological materials with increased resilience to perturbations such as strain-induced crystalline symmetry breaking, which may lead to robust topological applications as well as unexpected topology beyond the usual space group classifications., Nat. Phys. (2022)

Background: The emergence of immune checkpoint inhibitors has greatly changed the treatment outcome of advanced malignant tumors. The basic medication for patients with advanced solid tumors may affect the efficacy of immunotherapy. The use of proton pump inhibitors may change the acidic environment and inhibit intestinal flora, thereby affecting the efficacy of immunotherapy. To clarify the correlation between PPI administration and the prognosis of solid cancer patients treated with ICI, we conducted a meta-analysis.Method: Before February 12th, 2021, PubMed, Cochrane Library, Web of Science and EMBASE databases were used to search for eligible documents. The association of PPI administration with overall survival (OS) and progression-free survival (PFS), hazard ratio (HR) and 95% confidence interval (CI) were determined.Results: This study included 10 studies, a total of 4072 patients with solid cancer who received ICI treatment. Overall, the PPI administered with OS (HR=1.31 (1.11-1.52), P = 0.001) deteriorate significantly associated. In the subgroup analysis based on cancer type, PPI administration was associated with worsening of PFS in NSCLC, and better results of PFS in melanoma patients. In addition, between 30 days before the occurrence of ICI and 30 days after the occurrence of ICI, PPI administration may reduce the efficacy of ICI. Conclusion: Patients with solid cancer receiving ICI should use PPI with caution. However, only poor statistical results are observed on the OS, and further verification is still essential. This study was registered in PROSPERO with registration number CRD42021243707.

Two compounds with nitrobenzene-derived caging groups were designed and synthesized for cells and tissues imaging. After 350 nm irradiation, the two reagents can realize highly efficient fluorescence turn on with large Stokes shift. As for the two probes can bare out a common functional group of aldehyde group under UV irradiation, it may be used for detection of cysteine, DNA methylation in a spatiotemporal method with selectivity. The idea of design and synthesis might be used in other modified reagents for controlling biological function with light.

Nucleic acids contain a variety of different base modifications, such as decoration at the fifth position of cytosine, which is one of the most important epigenetic modifications. Nucleic acid epigenetics mediate a wide variety of biological processes, including embryonic development and gene regulation, genomic imprinting, differentiation, and X-chromosome inactivation. Furthermore, the modification level can be aberrantly expressed in distinct sets of tissue that can indicate different tumor onsets and canceration. Thus, the analysis of modified nucleobases may contribute to the understanding of epigenetic modification-related biological processes and the correlation of modified nucleobase patterns with disease states for clinical diagnosis and treatment. In addition to 5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxycytosine are found in organisms at a low content but are nevertheless extremely important chemical modifications, and 5-hydroxyuracil and 5-formyluracil compounds are also present. 5-Formyluracil is found in bacteriophages, prokaryotes, and mammalian cells. The 5-formyluracil content is higher in certain cancer tissues than in the normal tissues adjacent to the tumor. The content of 5-formyluracil in different cell tissues may have cell type specificity. With the continuous use of chemical tools, new detection technologies have greatly advanced the research on natural pyrimidine modifications. These modifications dynamically regulate the gene expression in eukaryotes and prokaryotes and provide mechanistic insights into the occurrence of diseases. Natural pyrimidine modifications act not only as intermediates for DNA demethylation or oxidative damage products but also as modulators of gene expression. Therefore, the development of more effective chemical tools will help us better understand the dynamic changes of natural pyrimidine modifications in vivo. In this Account, we summarize the recent advanced techniques for the detection of 5-formylpyrimidine (5-formylcytosine and 5-formyluracil) and highlight their great potential as biomarkers in biomedical applications. Focusing on the great urgency for the detection of epigenetic modifications, our group developed a series of methods for the qualitative and quantitative analysis of 5-formylpyrimidine in the past few years, aiming at facilitating the accurate detection and mapping of these epigenetic modifications. By the construction of probes, 5-formylpyrimidine can be selectively labeled. Using mass spectrometry, the epigenetic modifications can be quantified. Upon treatment under specific conditions, 5-formylcytosine can be recognized at single-base resolution. With this Account, we anticipate providing chemical and biological researchers with some insight to unlock the complex mechanism involved in 5-formylpyrimidine-related biological processes and stimulate more collaborative research interests from the different fields of materials, biological, medicine, and chemistry to promote the translational research of epigenetics in tumor diagnosis and treatment.

Small-molecule-based G4 isolation from genomic DNA has enabled the identification of a total of 51 446 PQSs (potential G-quadruplex sites). Incubating cells with PDP for 3 h to 72 h resulted in the differential expression of a variety of genes, indicating a potential function of G4s in gene regulation.

The rapid discovery of two-dimensional (2D) van der Waals (vdW) quantum materials has led to heterostructures that integrate diverse quantum functionalities such as topological phases, magnetism, and superconductivity. In this context, the epitaxial synthesis of vdW heterostructures with well-controlled interfaces is an attractive route towards wafer-scale platforms for systematically exploring fundamental properties and fashioning proof-of-concept devices. Here, we use molecular beam epitaxy to synthesize a vdW heterostructure that interfaces two material systems of contemporary interest: a 2D ferromagnet (1T-CrTe2) and a topological semimetal (ZrTe2). We find that one unit-cell (u.c.) thick 1T-CrTe2 grown epitaxially on ZrTe2 is a 2D ferromagnet with a clear anomalous Hall effect. In thicker samples (12 u.c. thick CrTe2), the anomalous Hall effect has characteristics that may arise from real-space Berry curvature. Finally, in ultrathin CrTe2 (3 u.c. thickness), we demonstrate current-driven magnetization switching in a full vdW topological semimetal/2D ferromagnet heterostructure device., Comment: Includes new data (ST-FMR) and calculations (spin Hall conductivity)

Summary Chemical modifications to nucleobases have a great influence on various cellular processes, by making gene regulation more complex, thus indicating their profound impact on aspects of heredity, growth, and disease. Here, we provide the first genome-wide map of 5-formyluracil (5fU) in living tissues and evaluate the potential roles for 5fU in genomics. We show that an azido derivative of (2-benzimidazolyl)acetonitrile has high selectivity for enriching 5fU-containing genomic DNA. The results have demonstrated the feasibility of using this method to determine the genome-wide distribution of 5fU. Intriguingly, most 5fU sites were found in intergenic regions and introns. Also, distribution of 5fU in human thyroid carcinoma tissues is positively correlated with binding sites of POLR2A protein, which indicates that 5fU may distributed around POLR2A-binding sites., Graphical Abstract, Highlights • The derivative of (2-benzimidazolyl)acetonitrile (azi-BIAN) can selectivity label 5fU • Azi-BIAN can selectively label and pull down 5fU in the genome for NGS • The first genome-wide map of 5fU in mammalian genomic DNA • 5fU is highly enriched at intergenic regions and introns, Chemistry; Genetics; Molecular Genetics

In organisms 5-formyluracil (5fU), which is known as a vital natural nucleobase, is widely present. Despite the recent development of sensor designs for organic fluorescent molecules for selective targeting applications, biocompatible and easily operated probe designs that are based on natural nucleobase modifications have rarely been reported. Here, we introduce the idea of 5fU as a multifunctional building block to facilitate the design and synthetic development of biosensors. The azide group was derived from the sugar of a nucleoside, which can be further used in the selective binding of cells or organelles through click chemistry with alkynyl-modified targeting groups. The aldehyde group of 5fU can react with different chemicals to generate environmentally sensitive nucleobases that have obvious characteristics, which precious reactants cannot achieve for selective fluorogenic switch-on detection of a specific target. We first synthesized 5fU analogues that had aggregation-induced emission properties, and then we used triphenylphosphonium as a mitochondria-targeting group to selectively image mitochondria in cancer cells and mouse embryonic stem cells. Additionally, the reagents exhibit a high selectivity for reaction with 5fU, which means that the method can also be used for the detection of 5fU. Combining the two characteristics, the idea of 5fU as a multifunctional building block in biosensor designs may potentially be applicable in 5fU site-specific microenvironment detection in future research.

5-Formylcytosine (5fC) is known as one of the key players in the process of active DNA demethylation and displays essential epigenetic functions in mammals. In spite of the blooming development of whole genome sequencing methods for this modified cytosine base, the easily operated gene specific-loci detection of 5fC has rarely been reported. Herein, we present a compound-mediated analysis of the content and site of 5fC by the polymerase chain reaction (PCR) assay. The molecule, namely azi-BP, which can selectively label 5fC and form a huge group through a click chemistry reaction, hindering the amplification activity of Taq DNA polymerase, acts as a “roadblock” and enables the quantitative analysis of 5fC by quantitative polymerase chain reaction (qPCR). The existence of 5fC in several fragment-specific genomic DNAs of mouse embryonic stem cells (mESCs) was successfully demonstrated using this method. In addition, the gene fragment containing 5fC can be easily biotinylated and enriched after labeling with azi-BP. Moreover, after azi-BP incorporation, the loss of the exocyclic 4-amino group of 5fC leads to C-to-T conversion and subsequent pairing with adenine (A) in the PCR, which can accurately identify 5fC sites at single-base resolution by site-specific mutation. Azi-BP shows high selectivity to 5fC among all modified pyrimidine bases, revealing that this compound-mediated assay can be applied for content and single-base resolution analysis for gene specific-loci of 5fC.

The curved composite box girder with corrugated steel webs (CBG with CSWs) shows a more complex performance compared to a straight one due to the coupled flexural-torsional effect caused by its curvature. However, the relevant studies on it were limited. In this paper, considering the shear lag effect of the flanges, the shear deformation of the steel webs, and the coupled flexural-torsional effect, the natural frequencies of the curved CBGs with CSWs were derived using the energy variation method and Hamilton principle. Free vibration experiments were conducted on three simply-supported curved CBGs with CSWs. Numerical analysis was performed using ANSYS software. According to the parametric analysis, the torsional kinetic energy and the additional effect of the restrained torsion have little effect on the natural frequencies in the flexural-torsional vibration, while they significantly affect the flexural mode component. The natural frequencies decrease with the increase of λ (the ratio of calculation span to the radius of the curved axis). When λ ≤ 0.5, the reduction is smaller than 5%, but larger than 10% when λ > 0.7. The span presents an insignificant influence on the fundamental frequency if λ remains constant. Based on the analytical and experimental researches, a simple-to-use equation was proposed to calculate the fundamental frequency of the curved CBGs with CSWs.

Correction for ‘Small-molecule-based human genome G4 profiling reveals potential gene regulation activity’ by Weiwu Zeng et al., Chem. Commun., 2019, 55, 2269–2272, DOI: 10.1039/C8CC10052G.

The identification of hydroxylmethyl- and formylpyrimidines in genomic DNA was a landmark event in epigenetics. Numerous laboratories in related fields are investigating the biology of these and other nucleic acid modifications. However, limitations in the ability to detect and synthesize appropriate modifications are an impediment. Herein, we explored a remarkable development in the selective detection of 5-formyluracil in both single-stranded and double-stranded DNA under mild conditions. The “switch-on” specificity towards 5-formyluracil enabled a high signal-to-noise ratio in qualitatively and quantitatively detecting materials containing 5-formyluracil, which is not affected by the presence of abasic sites and 5-formylcytosine, the modified cytosine counterpart of 5-formyluracil. In summary, the innoxiousness, convenience, and cost-efficiency of the 5-formyluracil phosphoramidite synthetic routine would promote the understanding of the epigenetic role of this natural thymidine modification.

Simultaneous fluorogenic switch-on detection and single-base resolution analysis of 5fC through yielding an intramolecular cyclization nucleobase has been presented., 5-Formylcytosine (5fC), which plays an important role in epigenetic functions, has received widespread attention in many related fields. Here, we demonstrate a new design for both the fluorogenic switch-on detection and single-base resolution analysis of 5fC through selectively reacting a reagent with 5fC to yield an intramolecular cyclization nucleobase. The generated product, bearing a similar benzothiazole-iminocoumarin scaffold, is highly fluorescent and enables us to qualitatively and quantitatively detect 5fC moieties in γ-irradiated calf thymus DNA. Additionally, losing the exocyclic 4-amino group in 5fC causes the incorporation of dATP through base pairing with the generated nucleobase during polymerase extension, which helped us to analyze the 5fC sites in both single- and double-stranded oligonucleotides. Our Sanger and Illumina sequencing results show great potential in single-base resolution analysis of 5fC. It is hopeful that a similar design may be used for more detection targets.

Biotinylated o-phenylenediamine directly tethered to naphthalimide can both enrich and fluorogenically label 5-formyluracil in DNA under physiological conditions., Recently, the detection of natural thymine modified 5-formyluracil has attracted widespread attention. Herein, we introduce a new insight into designing reagents for both the selective biotin enrichment and fluorogenic labelling of 5-formyluracil in DNA. Biotinylated o-phenylenediamine directly tethered to naphthalimide can switch on 5-formyluracil, under physiological conditions, which can then be used in cell imaging after exposure to γ-irradiation. In addition, its labelling property caused the polymerase extension to stop in the 5-formyluracil site, which gave us more information than the fluorescence did itself. The idea of detecting 5-formyluracil might be used in the synthesis of other modified diaminofluoresceins.

G-quadruplexes, one of the most significant secondary structure of nucleic acid, are formed by stacking G quartets, which received broad interests due to their involvement in telomere function, gene transcription and recombination. As for ligand, better selectivity for G-quadruplex against other DNA or RNA structures and higher ability to stabilize G-quadruplex are necessary. In addition, developing a new probe to recognize G-quadruplex is desired for utilizing G-quadruplex structure to relevant biological processes. In this study, we report a Cy5 labelled ligand (named PDP-Cy5) developed as a near-infrared fluorescent ligand for G-quadruplexes both in DNA and RNA. The results indicated that PDP-Cy5 selectively induced the formation of intramolecular G-quadruplexes with strong binding affinity. Furthermore, this Cy5 labelled ligand can effectively stabilize G-quadruplexes. Moreover, the direct visualization of G-quadruplexes in gel, even on cell level is realized by using PDP-Cy5.

A naphthalimide hydroxylamine probe has been designed and synthesized to selectively label the whole natural aldehydes present in DNAs including 5-formylcytosine, 5-formyluracil, and abasic sites. The fluorescence characteristics of the generated nucleosides have been examined in detail, and the reaction activities of hydroxylamine, amine groups toward aldehydes in DNA have been discussed with others, which will be a vital reference for designing chemicals for selective labeling of DNAs.

5-Formyluracil (5fU) based probes were designed and synthesized to detect Al3+ ions in vitro and in biological systems. These probes were synthesised using furan-2-carbohydrazide (fr) and 5fU derivatives. We also selectively labelled 5-formyluracil in DNA with the help of Al3+.

An azide and hydrazine tethered to a naphthalimide analogue was created to selectively react with 5-formyluracil in one system and fluorogenically label 5-formylcytosine in another system. A biotin group was also introduced by copper-free click chemistry through selective labelling of the aldehyde present in 5-formylpyrimidine.

We demonstrated electron transfer across the FeSe/STO interface and showed its dominant role in Tc enhancement in this system., The exact mechanism responsible for the significant enhancement of the superconducting transition temperature (Tc) of monolayer iron selenide (FeSe) films on SrTiO3 (STO) over that of bulk FeSe is an open issue. We present the results of a coordinated study of electrical transport, low temperature electron energy-loss spectroscopy (EELS), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) measurements on FeSe/STO films of different thicknesses. HAADF-STEM imaging together with EELS mapping across the FeSe/STO interface shows direct evidence of electrons transferred from STO to the FeSe layer. The transferred electrons were found to accumulate within the first two atomic layers of the FeSe films near the STO substrate. An additional Se layer is also resolved to reside between the FeSe film and the TiOx-terminated STO substrate. Our transport results found that a positive backgate applied from STO is particularly effective in enhancing Tc of the films while minimally changing the carrier density. This increase in Tc is due to the positive backgate that “pulls” the transferred electrons in FeSe films closer to the interface and thus enhances their coupling to interfacial phonons and also the electron-electron interaction within FeSe films.

Nucleic acids can be sequenced by a chemical procedure that partially damages the nucleotide positions at their base repetition. Many methods have been reported for the selective recognition of guanine. The accurate identification of guanine in both single and double regions of DNA and RNA remains a challenging task. Herein, we present a new, non-toxic and simple method for the selective recognition of guanine in both DNA and RNA sequences via ammonium persulfate modification. This strategy can be further successfully applied to the detection of 5-methylcytosine by using PCR.

A conserved guanine-rich sequence could be a new target for anti–hepatitis C virus drug development., G-quadruplex (G4) is one of the most important secondary structures in nucleic acids. Until recently, G4 RNAs have not been reported in any ribovirus, such as the hepatitis C virus. Our bioinformatics analysis reveals highly conserved guanine-rich consensus sequences within the core gene of hepatitis C despite the high genetic variability of this ribovirus; we further show using various methods that such consensus sequences can fold into unimolecular G4 RNA structures, both in vitro and under physiological conditions. Furthermore, we provide direct evidences that small molecules specifically targeting G4 can stabilize this structure to reduce RNA replication and inhibit protein translation of intracellular hepatitis C. Ultimately, the stabilization of G4 RNA in the genome of hepatitis C represents a promising new strategy for anti–hepatitis C drug development.

DNA methylation is a significant epigenetic modification of the genome that is involved in regulating many cellular processes. An increasing number of human diseases have been discovered to be associated with aberrant DNA methylation, and aberrant DNA methylation has been deemed to be a potential biomarker for diseases such as cancers. A safe, nontoxic, and sensitive method for accurate detection of 5-methylcytosine in genomic DNA is extremely useful for early diagnosis and therapy of cancers. In this paper, we established a novel system to detect 5-methylcytosine, which is based on bisulfite treatment, asymmetric PCR, and specific DNA damaging reagents. Our method could be used for identifying the loci of 5mC in genomic DNA and detecting the DNA methylation levels in tissues as well.

This study aims to observe and discuss the curative and side effects of three different fractionation regimen of three-dimensional conformable radiotherapy (3DCRT) for esophageal cancer. A total of 169 untreated patients of esophageal cancer were randomized into three groups: groups A (conventional group, 2.0 Gy per time), B (2.5 Gy group, 2 Gy per time), and C (3.0 Gy group, 3.0 Gy per time), respectively. Groups A, B, and C are similar in terms of partial response (P = 0.35). However, the three groups had no significant differences in terms of the complete response (P = 0.63). The three-year survival rate of group B was higher than those of the other two groups, and the difference was significant (P = 0.047). For the three-year local control rate, that of group B was also higher than those of groups A and C, but the difference was not significant (P = 0.067). The incidence rate of 3 level esophagitis and bronchitis was highest in group C (P = 0.023 and P = 0.064). The 3 level tardive radioactive esophagitis in group C was higher than those in other two groups (P = 0.037 and P = 0.04). The incidence rate of the 3 level advanced lung reaction was also the highest in the three groups (P = 0.041). The effect is better and the side effect is tolerable for the 2.5 Gy per fraction, 5 times per week; thus, it can be used clinically for 3DCRT for esophageal carcinoma.

With angle-resolved photoemission spectroscopy, gap opening is resolved at up to room temperature in the Dirac surface states of molecular beam epitaxy grown Cr-doped Bi2Se3 topological insulator films, which, however, show no long-range ferromagnetic order down to 1.5 K. The gap size is found decreasing with increasing electron-doping level. Scanning tunneling microscopy and first-principles calculations demonstrate that substitutional Cr atoms aggregate into superparamagnetic multimers in the Bi2Se3 matrix, which contribute to the observed chemical-potential-dependent gap opening in the Dirac surface states without long-range ferromagnetic order.

In the chapter, we review two proto-type models of topological insulators, namely the Bernevig-Hughes-Zhang model for HgTe quantum wells and the four band model for Bi 2 Se 3 family of materials. Based on these two simple models, we discuss helical edge/surface states of topological insulators, as well as their exotic physical properties, including total angular momentum, spin and orbital textures, topological stability, and topological response of the surface states. Moreover, we summarize the basic principle to search for topological insulators from these two models and discuss the related topological materials.

Mucoepidermoid carcinoma (MEC) is typically located in the salivary, lacrimal, and tracheobronchial glands and rarely presents in the esophagus. MEC is commonly characterized by squamous cells, mucus-secreting cells, and intermediate cells. This report presents the case of a 57-years-old male with a three months history of cough and shortness of breath. Computer tomography (CT) scans revealed a tumor locating in the left hilar. The histological report was squamous carcinoma. After three circles of chemotherapy, the patient complained of dysphagia. The electronic gastroscope showed a protrusion which 30-34 cm from the incisors. The tumor was histopathologically determined to be MEC of esophagus. The patient refused to surgery and concurrent chemoradiotheray; so, radiotherapy and sequential chemotherapy were performed, and after one year of follow up, the disease of esophagus recurrence; the patient was died of hemorrhage of esophagus for tumor progression. The literatures of MEC are also reviewed in this study.