UV/Ozone treatment to reduce metal-graphene contact resistance

We report reduced contact resistance of single-layer graphene devices by using ultraviolet ozone (UVO) treatment to modify the metal/graphene contact interface. The devices were fabricated from mechanically transferred, chemical vapor deposition (CVD) grown, single layer graphene. UVO treatment of graphene in the contact regions as defined by photolithography and prior to metal deposition was found to reduce interface contamination originating from incomplete removal of poly(methyl methacrylate) (PMMA) and photoresist. Our control experiment shows that exposure times up to 10 minutes did not introduce significant disorder in the graphene as characterized by Raman spectroscopy. By using the described approach, contact resistance of less than 200 {\Omega} {\mu}m was achieved, while not significantly altering the electrical properties of the graphene channel region of devices.Comment: 17 pages, 5 figure

Strengthening and microbial regulation mechanism of Bacillus on purification device for grass carp culture wastewater

Aquaculture wastewater (AW) poses a threat to natural aquatic environments. Microecological agents are widely used to regulate and purify AW, with Bacillus being the most common. To evaluate the AW purification effect of adding Bacillus subtilis and Bacillus licheniformis to an AW treatment device, we constructed an experimental device including a small grass carp culture pond and three groups of cuboid reactors. The effects of adding the two strains to the AW treatment reactor on the AW purification effect and the microbiota compositions in the AW and packing surface biofilm were analyzed via high-throughput sequencing of the 16S rRNA gene. Our results showed that adding Bacillus bacteria to reactors improved the total nitrogen (TN) removal efficiency and reduced the chemical oxygen demand (COD). Adding both the B. subtillis and B. licheniformis preparations significantly increased the abundance of Firmicutes in the water microbiota of the reactor at the middle and end stages of the experiment. The addition of Bacillus changed the microbiota composition in the water and packing surface biofilm and significantly increased the abundance of Bacillus at the middle and later stages of the experiment. Therefore, the addition of Bacillus improved the TN removal efficiency in the AW grass carp treatment reactors and significantly reduced the COD in the AW by increasing the abundance of Bacillus and changing the microbiota composition in the system. We provide an effective way for improving the purification capacity of biofilm reactor

Reversing tumor stemness via orally targeted nanoparticles achieves efficient colon cancer treatment

The acquisition of stemness in colorectal cancer (CRC) attributed to the recurrence and metastasis in CRC treatment. Therefore, targeting the stemness of CRC forms a basis for the development of novel therapeutic approaches. However, the pain and systemic side effect from long-term of venipuncture injection remain great challenges to neoplastic treatment. Here, we introduce an oral drug delivery system for sustained release of BMI-1 inhibitor (PTC209) that reverse the stemness of CRC to over-come these obstacles. In this system, nanoparticles modified with hyaluronic acid (HA) showed high-affinity to CD44 / CD168 overexpressed-CRC cells, and efficiently targeted to tumor site in a metastatic orthotropic colon cancer mouse model by oral administration. Significantly, the observed tumor growth inhibition is accompanied by decreased expression of stemness markers in the tumor tissues. Furthermore, HA-NPs-PTC209 also significantly prevented metastasis to the gastrointestinal system, while failing to exhibit acute side effects. In summary, we have developed an orally active, easily synthesized nanomedicine that shows promise for the treatment of colon cancer

Suppression of Tumor Energy Supply by Liposomal Nanoparticle-Mediated Inhibition of Aerobic Glycolysis

Aerobic glycolysis enables cancer cells to rapidly take up nutrients (e.g., nucleotides, amino acids, and lipids) and incorporate them into the biomass needed to produce a new cell. In contrast to existing chemotherapy/radiotherapy strategies, inhibiting aerobic glycolysis to limit the adenosine 5′-triphosphate (ATP) yield is a highly efficient approach for suppressing tumor cell proliferation. However, most, if not all, current inhibitors of aerobic glycolysis cause significant adverse effects because of their nonspecific delivery and distribution to nondiseased organs, low bioavailability, and a narrow therapeutic window. New strategies to enhance the biosafety and efficacy of these inhibitors are needed for moving them into clinical applications. To address this need, we developed a liposomal nanocarrier functionalized with a well-validated tumor-targeting peptide to specifically deliver the aerobic glycolysis inhibitor 3-bromopyruvate (3-BP) into the tumor tissue. The nanoparticles effectively targeted tumors after systemic administration into tumor-bearing mice and suppressed tumor growth by locally releasing 3-BP to inhibit the ATP production of the tumor cells. No overt side effects were observed in the major organs. This report demonstrates the potential utility of the nanoparticle-enabled delivery of an aerobic glycolysis inhibitor as an anticancer therapeutic agent

Parameter estimation for nonergodic Ornstein-Uhlenbeck process driven by the weighted fractional Brownian motion

Abstract In this paper, we consider the nonergodic Ornstein-Uhlenbeck process X 0 = 0 , d X t = θ X t d t + d B t a , b , t ≥ 0 , $$X_{0}=0, \quad\quad dX_{t}=\theta X_{t} \,dt+dB_{t}^{a,b},\quad t\geq0,$$ driven by the weighted fractional Brownian motion B t a , b $B_{t}^{a,b}$ with parameter a and b. Our goal is to estimate the unknown parameter θ > 0 $\theta>0$ based on the discrete observations of the process. We construct two estimators θ ˆ n $\hat{\theta}_{n}$ and θ ˇ n $\check{\theta}_{n}$ of θ and show their strong consistency and the rate consistency