Nuclear Pyruvate Kinase M2 Functional Study in Cancer Cells

Cancer cells take more glucose to provide energy and phosphoryl intermediates for cancer progression. Meanwhile, energy-provider function of mitochondria in cancer cells is disrupted. This phenomenon is so-called Warburg effect, which is discovered over eighty years ago. The detail mechanisms for Warburg effect are not well defined. How glycolytic enzymes contribute to cancer progression is not well known. PKM2 is a glycolytic enzyme dominantly localized in the cytosol, catalyzing the production of ATP from PEP. In this study, we discovered that there were more nuclear PKM2 expressed in highly proliferative cancer cells. The nuclear PKM2 levels are correlated with cell proliferation rates. According to our microarry analyses, MEK5 gene was upregulated in PKM2 overexpression cells. Our studies showed that PKM2 regulated MEK5 gene transcription to promote cell proliferation. Moreover, nuclear PKM2 phosphorylated Stat3 at Y705 site using PEP as a phosphoryl group donor to regulate MEK5 gene transcription. Our study also showed that double phosphorylated p68 RNA helicase at Y593/595 interacted with PKM2 at its FBP binding site. Under the stimulation of growth factors, p68 interacted with PKM2 to promote the conversion from tetrameraic to dimeric form so as to regulate its protein kinase activity. Overexpression PKM2 in less aggressive cancer cells induced the formation of multinuclei by regulating Cdc14A gene transcription. Overall, this study presents a step forward in understanding the Warburg effect

Hg 0 capture over MoS2 nanosheets containing adsorbent: effects of temperature, space velocity, and other gas species

Fossil fuel burning is the largest anthropogenic source of mercury emission, which is expected to be the first industrial sector to be addressed under Minamata Convention. In this research, the preliminary investigation has been carried out to understand the effects of temperature, space velocity, and SO2 and O2 on Hg0 capture over MoS2 nanosheets containing elemental mercury adsorbent. The adsorbent exhibited excellent performance in the removal of Hg0 at a low temperature below 125°C (particularly at 50°C) with a space velocity below 9.0×104 ml/(h·g). It was found that the presence of O2 had positive effect on Hg0 removal whilst SO2 had slightly negative effect on mercury capture at low temperature, such as 50°C. However, such negative effect became negligible when O2 co-existed with SO2 in the simulated flue gas. The research provided fundamental information for further development of the 2D graphene-like MoS2 nanosheets containing adsorbent for mercury capture

Phase interrogation SPR sensing based on white light polarized interference for wide dynamic detection range

A phase surface plasmon resonance (SPR) sensing technology based on white light polarized interference in common-path geometry is reported. A halogen lamp is used as the excitation source of the SPR sensor. The fixed optical path difference (OPD) between p- and s-polarized light is introduced by a birefringence crystal to produce sinusoidal spectral interference fringes. The SPR phase is accurately extracted from the interference fringes using a novel iterative parameter-scanning cross-correlation algorithm. The dynamic detection range is expanded by tracking the best SPR wavelength, which is identified using a window Fourier algorithm. The experimental results show that the sensitivity of this SPR system was 1.3 × 10−7 RIU, and the dynamic detection range was 0.029 RIU. This sensor, not only simple to implement and cost efficient, requires no modulators

High-throughput imaging surface plasmon resonance biosensing based on ultrafast two-point spectral-dip tracking scheme

Wavelength interrogation surface plasmon resonance imaging (λSPRi) has potential in detecting 2-dimensional (2D) sensor array sites, but the resonance wavelength imaging rate limits the application of detecting biomolecular binding process in real time. In this paper, we have successfully demonstrated an ultrafast λSPRi biosensor system. The key feature is a two-point tracking algorithm that drives the liquid crystal tunable filter (LCTF) to achieve fast-tracking of the resonance wavelength movement caused by the binding of target molecules with the probe molecules on the sensing surface. The resonance wavelength measurement time is within 0.25s. To date, this is the fastest speed ever reported in λSPRi. Experiment results show that the sensitivity and dynamic are 2.4 × 10−6 RIU and 4.6 × 10−2 RIU, respectively. In addition, we have also demonstrated that the system has the capability of performing fast high-throughput detection of biomolecular interactions, which confirms that this fast real-time detecting approach is most suitable for high-throughput and label-free biosensing applications

Ultra-small carbon nanospheres (< 50 nm) of uniform tunable sizes by a convenient catalytic emulsion polymerization strategy: superior supercapacitive and sorption performances

Porous carbon nanospheres have received enormous attention for various applications. Though there are several elegant strategies existing for the synthesis of relatively large carbon nanospheres (> ca. 100 nm), the synthesis of carbon nanospheres with well-defined tunable ultra-small sizes (< 50 nm) has often been challenging while such ultra-small nanospheres are much more valuable. A novel, convenient, and scalable catalytic emulsion polymerization technique is demonstrated in this paper for highly efficient synthesis of ultra-small carbon nanospheres with uniform tunable sizes in the range of 11–38 nm. In this strategy, a simple change of the emulsion polymerization recipe renders a convenient yet efficient tuning of the size of the carbon nanospheres. In particular, activated carbon nanospheres (A-CNS21 of average size of 21 nm) obtained by carbonization in the presence of KOH as the chemical activation agent is featured with very high surface area (2,360 m2/g) and the desired hierarchical macro-/meso-/micropore structures resulting from nanosphere packing/aggregation. A-CNS21 is demonstrated to have superior high-rate supercapacitive performances and outstanding sorption capacities towards volatile organic compounds (VOCs), H2, and CO2, which are comparable to or even better than the best results reported to date in these applications. To the best of our knowledge, this is the first synthesis of ultrasmall carbon nanospheres with uniform tunable sizes and superior performances for these applications by the emulsion polymerization strategy

Structural defects in 2D MoS2 nanosheets and their roles in the adsorption of airborne elemental mercury

In this research, ab initio calculations and experimental approach were adopted to reveal the mechanism of Hg0 adsorption on MoS2 nanosheets that contain various types of defects. The ab initio calculation showed that, among different structural defects, S vacancies (Vs) in the MoS2 nanosheets exhibited outstanding potential to strongly adsorb Hg0. The MoS2 material was then prepared in a controlled manner under conditions, such as temperature, concentration of precursors, etc., that were determined by adopting the new method developed in this study. Characterisation confirmed that the MoS2 material is of graphene-like layered structure with abundant structural defects. The integrated dynamic and steady state (IDSS) testing demonstrated that the Vs-rich nanosheets showed excellent Hg0 adsorption capability. In addition, ab initial calculation on charge density difference, PDOS, and adsorption pathways revealed that the adsorption of Hg0 on the Vs-rich MoS2 surface is non-activated chemisorption

Xue-Jie-San restricts ferroptosis in Crohn’s disease via inhibiting FGL1/NF-κB/STAT3 positive feedback loop

Crohn’s disease (CD) is an incurable inflammatory bowel disease due to unclear etiology and pathogenesis. Accumulating evidences have shown the harmful role of ferroptosis in CD onset and development. Additionally, fibrinogen-like protein 1 (FGL1) has been verified to be a potential therapeutic target of CD. Xue-Jie-San (XJS) is an effective prescription for treating CD. However, its therapeutic mechanism has not been fully elucidated. This study aimed to determine whether XJS alleviating CD via regulating ferroptosis and FGL1 expression. A colitis rat model was induced by 2,4,6-trinitrobenzene sulfonic acid and treated with XJS. The disease activity indices of the colitis rats were scored. Histopathological damage was assessed using HE staining. ELISA was performed to examine inflammatory cytokines. Transmission electron microscopy was utilized to observe ultrastructure changes in intestinal epithelial cells (IECs). Iron load was evaluated by examining iron concentrations, the expressions of FPN, FTH and FTL. Lipid peroxidation was investigated through detecting the levels of ROS, 4-HNE, MDA and PTGS2. Furthermore, the SLC7A11/GSH/GPX4 antioxidant system and FGL1/NF-κB/STAT3 signaling pathway were examined. The results showed that colitis was dramatically ameliorated in the XJS-treated rats as evidenced by relief of clinical symptoms and histopathological damages, downregulation of pro-inflammatory cytokines IL-6, IL-17 and TNF-α, and upregulation of anti-inflammatory cytokine IL-10. Furthermore, XJS administration led to ferroptosis inhibition in IECs by reducing iron overload and lipid peroxidation. Mechanistically, XJS enhanced the SLC7A11/GSH/GPX4 antioxidant system negatively regulated by the FGL1/NF-κB/STAT3 positive feedback loop. In conclusion, XJS might restrain ferroptosis in IECs to ameliorate experimental colitis by inhibition of FGL1/NF-κB/STAT3 positive feedback loop

Interdigitated Back‐Contacted Carbon Nanotube–Silicon Solar Cells

Carbon/silicon heterojunctions provide a new perspective for silicon solar cells and in particular those made from carbon nanotubes (CNTs) have already achieved industrial-level power conversion efficiency and device size when using organic passivation and a back-junction design. However, the current state of the art device geometry for silicon photovoltaics is the interdigitated back contact (IBC) cell and this has yet to be demonstrated for CNT/Si solar cells due to the complexity of fabricating the required patterns. Herein, IBC-CNT solar cells are demonstrated via the simple spin coating of a conductive hole-selective passivating film and the evaporation of buried silicon oxide/magnesium electron-selective contacts for both polarities. The CNT coverage area fraction (fCNT) and the gap between the two polarities are optimized to minimize electrical shading loss and ensure high photocarrier collection. Large-area (4.76 cm2) highly efficient (17.53%) IBC-CNT solar cells with a Voc of 651 mV and Jsc of 40.56 mA cm−2 are demonstrated and are prepared with one alignment step for the CNT/Si contact, and photolithographic-free and room-temperature processes. These performance parameters are among the best for solution-processed dopant-free IBC schemes and indicate the feasibility of using low-dimensional carbon materials in IBC solar cells