A novel off-line multi-dimensional high-speed countercurrent chromatography strategy for preparative separation of bioactive neolignan isomers from Piper betle. L.

Separation and purification of naturally occurring isomers from herbs are still challenging. High-speed counter-current chromatography (HSCCC) has been applied to isolate natural products. In this study, an off-line multi-dimensional high-speed counter-current chromatography (multi-D HSCCC) strategy was developed utilizing the in situ concentration technique with online storage recycling elution to rapidly separate bioactive isomeric neolignans from chloroform-partitioned samples of the plant Piper betle L.

Bulk and single-cell alternative splicing analyses reveal roles of TRA2B in myogenic differentiation.

Alternative splicing (AS) disruption has been linked to disorders of muscle development, as well as muscular atrophy. However, the precise changes in AS patterns that occur during myogenesis are not well understood. Here, we employed isoform long-reads RNA-seq (Iso-seq) and single-cell RNA-seq (scRNA-seq) to investigate the AS landscape during myogenesis.

The ubiquitin specific protease 7 stabilizes HPV16E7 to promote HPV-mediated carcinogenesis.

Human papillomavirus (HPV) encoded E7 oncoprotein plays an important role in supporting the viral productive cycle and inducing cancer phenotypes. The ability of E7 to exercise these functions, partly, depends upon its steady-state level. HPV manipulates the host de-ubiquitination pathway to maintain the stability of its viral proteins.

Interaction between Human Papillomavirus-Encoded E6 Protein and AurB Induces Cell Immortalization and Proliferation-A Potential Target of Intervention.

The human papillomavirus E6 and E7 oncoproteins interact with a different subset of host proteins, leading to dysregulation of the apoptotic, cell cycle, and signaling pathways. In this study, we identified, for the first time, that Aurora kinase B (AurB) is a interacting partner of E6. We systematically characterized the AurB-E6 complex formation and its consequences in carcinogenesis using a series of and cell-based assays.

Acetylenic spiroketal enol ethers from and their synergistic antibacterial effects on methicillin-resistant .

Synergistic bioassay-guided isolation of the extracts of L, which belongs to the family Asteraceae, afforded two acetylenic spiroketal enol ethers, namely rupesdiynes A () and B (). Their structures were determined based on spectroscopic analysis and experimental and calculated ECD investigations. The two compounds exhibited synergistic activity and were able to reduce the minimum inhibitory concentration (MIC) of oxacillin four-fold, with a fractional inhibitory concentration index (FICI) of 0.

E6-Encoded by Cancer-Causing Human Papillomavirus Interacts with Aurora Kinase A To Promote HPV-Mediated Carcinogenesis.

The expression of human papillomavirus (HPV) oncoproteins perturbed multiple cellular events of the host cells, leading to the formation of cancer phenotypes. Our current and previous studies indicated that Aurora kinase A (AurA), a mitotic regulator that is often aberrantly expressed in human cancers, is preferentially bound to E6-encoded by cancer-causing HPV. AurA is believed to be important for the proliferation and survival of HPV-positive cells.

Review of the Standard and Advanced Screening, Staging Systems and Treatment Modalities for Cervical Cancer.

Cancer arising from the uterine cervix is the fourth most common cause of cancer death among women worldwide. Almost 90% of cervical cancer mortality has occurred in low- and middle-income countries. One of the major aetiologies contributing to cervical cancer is the persistent infection by the cancer-causing types of the human papillomavirus.

Neolignans from Have Synergistic Activity against Antibiotic-Resistant .

A phytochemical investigation of an extract of the leaves of , guided by a synergistic antibacterial screen, led to the isolation and structural elucidation of 10 new neolignans, Pibeneolignan A-J (-), together with 11 known compounds. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic data, single-crystal X-ray diffraction analysis, and experimental and calculated ECD investigations. Compounds and are new naturally occurring neolignan skeletons, based on the cyclohept-2-ene-1,4-dione framework.

The Phytochemistry and Pharmacology of Hypericum.

Hypericum L. is a genus of the family Hypericaceae within the dicotyledones. The constituents of Hypericum species are valued for their important biological properties.

Theoretically designed two-dimensional γ-CO as an effective gas separation membrane for hydrogen purification.

A high-performance gas separation membrane for hydrogen (H) purification is still highly desirable for the sustainable development of our society. Based on the structure of γ-graphyne, we theoretically designed the two-dimensional nanomaterials γ-CX (X = O, S or Se) with intrinsic pores that may be suitable for gas separation. By first-principles calculations, we obtained the geometric structures of γ-CX, and confirmed that γ-CO and γ-CS are stable at room temperature.

Mechanical, Electronic, and Magnetic Properties of NiX (X = Cl, Br, I) Layers.

Since the recent experimental discovery of the CrI and CrGeTe monolayers, van der Waals (vdW) layered transition metal compounds have been recognized as promising candidates to realize 2D ferromagnetic (FM) semiconductors. However, until now, only limited compounds have been proposed to be ferromagnetic semiconductors. Here, on the basis of first-principles calculations, we report that the monolayer, Janus monolayer, and bilayer of NiX (X = Cl, Br, I) are intrinsic 2D FM semiconductors.

Confinement boosts CO oxidation on an Ni atom embedded inside boron nitride nanotubes.

To date, most studies of heterogeneous catalysis have focused on metal particles supported on the surface of substrates. However, studies of the catalytic properties of metallic nanoparticles supported on the interior surface of nanotubes are rare. Using first-principles calculations based on density functional theory, we have studied the CO oxidation on a single nickel atom confined in a nitrogen vacancy on the inside surface of boron nitride nanotubes (BNNT).

[Changes of serum anti-schistosome antibody levels in schistosomiasis japonica patients after treatment].

Objective: To investigate the changes of serum anti-schistosome antibody titers in schistosomiasis japonica patients after treatment, in order to provide the evidence for formulating the schistosomiasis surveillance program in marshland and lake regions.

Methods: Upon prospective cohort study, the stool examination positive schistosomiasis patients and blood examination positive suspected patients (the titer was more than 1:80, including 1:80) were selected as the research objects in Jiangling County in 2014, and they received the 2-day praziquantel therapy. Half year, one year and two years after the treatment, their blood samples and fecal samples were collected for IHA anti-schistosome antibody detections and schistosome egg and miracidium detections.

[Effect of two-level community-based health education pattern on schistosomiasis control].

Objective: To implement a two-level community-based health education pattern of schistosomiasis in residents of endemic areas in marshland and lake regions, so as to explore the suitable pattern of health education under hypo-endemic situation.

Methods: Two schistosomiasis endemic villages in Jiangling County, Hubei Province were collected as study areas, and among which, one village was treated as an intervention group, where the two-level community-based health education pattern as well as regular control measures was implemented; the other village was a control group, where only regular control measures were implemented. The awareness rates on schistosomiasis control, the rates of correct behavior and the compliance rates of examination, treatment and chemotherapy of the two groups before and after the intervention were compared.

Ar plasma irradiation improved optical and electrical properties of TiO₂/Ag/TiO₂ multilayer thin film.

Embedding a thin metal layer between two thin dielectric or semiconductor layers [dielectric/metal/dielectric (DMD)] leads to a kind of transparent electrode that is promising as a substitute for the currently widely applied indium tin oxide electrode. However, the optical and electrical properties of DMD still wait for further improvement. In this study, Ar plasma irradiation (API) was, for the first time to our knowledge, applied to improve the optical and electrical properties of a TiO2/Ag/TiO2 electrode that was fabricated by electron-beam evaporation of TiO2 and electric-resistance heating of high purity Ag under vacuum.

[Effect of Parasep® feces centrifuge tube method on detecting schistosome eggs].

Objective: To evaluate the effect of the Parasep® feces centrifuge tube method on detecting schistosome eggs.

Methods: A total of 803 residents aged from 6-65 years were selected in 2 schistosomiasis endemic villages, Jiangling County, Hubei Province, and their stool samples were collected and detected parallelly by the Kato-Katz technique, nylon silk egg hatching method, and Parasep® feces centrifuge tube method at the same time.

Results: Among the 803 people, 15 cases were found of schistosome egg positive, and the positive rate was 1.

A promising monolayer membrane for oxygen separation from harmful gases: nitrogen-substituted polyphenylene.

We theoretically demonstrate that N-substitutional doping dramatically reduces the diffusion barrier for oxygen passing through the pores of polyphenylene, leading to a massive enhancement in O2 selectivity over various harmful gases with excellent permeance at appropriate temperatures for O2 across an N-doped polyphenylene in a unit cell.

Theoretical study of CO oxidation on cationic, neutral, and anionic AuM dimers (M = Pd and Ag).

The CO and O2 adsorption as well as CO oxidation on cationic, neutral, and anionic AuM dimers (M = Pd, Ag) are studied by density functional calculations. Our results show that CO and O2 are adsorbed more stably on AuPd dimers than on AuAg dimers with corresponding charge state. O2 is favorable to be adsorbed on Pd atom in AuPd(+), AuPd and AuPd(-) dimers.

A B-C-N hybrid porous sheet: an efficient metal-free visible-light absorption material.

The polyphenylene network, known as porous graphene, is one of the most important and widely studied two-dimensional materials. As a potential candidate for photocatalysis and photovoltaic energy generation, its application has been limited by the low photocatalytic activity in the visible-light region. State-of-the-art hybrid density functional theory investigations are presented to show that an analogous B-C-N porous sheet outperforms the pristine polyphenylene network with significantly enhanced visible-light absorption.

Boron-substituted graphyne as a versatile material with high storage capacities of Li and H2: a multiscale theoretical study.

Based on density functional theory (DFT), first-principles molecular dynamics (MD), and the grand canonical ensemble Monte Carlo (GCMC) method, we investigated the boron substitution in aromatic rings of graphyne in terms of geometric and electronic structures as well as its bifunctional application including Li and H2 storage. The calculated binding energies of B-doped graphyne (BG) are significantly enhanced at two adsorptive sites compared to pristine graphyne, leading to high lithiation potentials of 2.7 V in 6Li@1BG, and even higher with 3.

Two-Dimensional Hexagonal Transition-Metal Oxide for Spintronics.

Two-dimensional materials have been the hot subject of studies due to their great potential in applications. However, their applications in spintronics have been blocked by the difficulty in producing ordered spin structures in 2D structures. Here we demonstrated that the ultrathin films of recently experimentally realized wurtzite MnO can automatically transform into a stable graphitic structure with ordered spin arrangement via density functional calculation, and the stability of graphitic structure can be enhanced by external strain.

The strain effect on colossal oxygen ionic conductivity in nanoscale zirconia electrolytes: a first-principles-based study.

Density functional theory calculations and first-principles molecular dynamics (MD) simulations have been performed to examine the strain effect on the colossal oxygen ionic conductivity in selected sandwich structures of zirconia electrolytes. For the KTaO(3)/YSZ/KTaO(3) sandwich structure with 9.7% lattice mismatch, transition state calculations indicate that the strain effect changes the oxygen migration pathways from straight line into zigzag form and reduces the energy barrier by 0.

Tunable band gap and hydrogen adsorption property of a two-dimensional porous polymer by nitrogen substitution.

After substitution of carbon by nitrogen, the electronic structures of the porous graphene have been studied by the density functional theory calculations. The N substitutional site without hydrogen passivation leads to a tunable energy gap of the two-dimensional porous polymer, depending on the number of N atoms in a unit cell. Moreover, the increasing number of N in an aromatic ring enhances the binding energies between hydrogen molecules and pre-adsorbed Li atoms from 1H(2) to 3H(2).

Two-dimensional organometallic porous sheets with possible high-temperature ferromagnetism.

With the rapid development of modern nanotechnology, molecular self-assembly has become an important method to fabricate new functional devices, and to provide an arena for theoretical material designs. In this paper, we propose that freestanding two-dimensional organometallic porous sheets (PSs), which can be formed by molecular self-assembly on metal surfaces, are ideal low-dimensional magnetic materials with room-temperature ferromagnetism. Through comprehensive first-principles calculations, we show that the freestanding organometallic sheets, which are assembled by transition metals (TMs) (Mn and V) and benzene molecules, favor ferromagnetic coupling with strong exchange interactions.