Aberrant DNA methyltransferase 1 expression in clear cell renal cell carcinoma development and progression

Objective: To better understand the contribution of dysregulated DNA methyltransferase 1(DNMT1) expression to the progression and biology of clear cell renal cell carcinoma(ccRCC).Methods: We examined the differences in the expression of DNMT1 in 89 ccRCC and 22 normal tissue samples by immunohistochemistry. In addition, changes in cell viability, apoptosis, colony formation and invading ability of ccRCC cell lines(786-0 and Caki-1) were assessed after transfection with DNMT1 siRNA.Results: We found DNMT1 protein was significantly higher expressed in ccRCC than that of in no-tumor tissues(56.2% and 27.3%, respectively, P=0.018). The expression of DNMT1 was strongly associated with ccRCC tumor size, tumor pathology stage, histological grading, lymph node metastasis, vascular invasion, recurrence and prognosis. Moreover, knockdown of DNMT1 expression significantly inhibited ccRCC cell viability, induced apoptosis, decreased colony formation and invading ability.Conclusions: Expression of DNMT1 protein is increased in ccRCC tissues, and DNMT1 expression is associated with poor prognosis of patients. Experiments in vitro further showed DNMT1 played an essential role in proliferation and invasion of renal cancer cells. Moreover, targeting this enzyme could be a promising strategy for treating ccRCC, as evidenced by inhibited cell viability, increased apoptosis, decreased colony formation and invading ability.

Recycle of Wastewater from Lead-Zinc Sulfide Ore Flo-tation Process by Ozone/BAC Technology

Lead-zinc sulphide ore contains lead sulphide (galena), and zinc sulphide (sphalerite). In the first flotation stage, galena is rendered hydrophobic with an organic collector such as xanthate, while sphalerite is kept from floating by depressants, and in the second flotation stage, activator was used to activated zinc flotation. Since the organic regent used are different in the two flotation stage, wastewater from the second zinc flotation stage can’t be directly recycled to the first lead flotation stage. Wastewater from flotation process for concentrating lead-zinc sulphide ore often containing organic compounds such as diethyldithiocarbamate(DDTC), xanthate, terpenic oil(2# oil) and thionocarbamate esters (Z-200), are environmentally hazardous. Their removal from contaminated water and the reuse of the water is one of the main challenges facing lead-zinc sulphide ore processing plants. In this study, synthetic wastewater containing DDTC, xanthate, 2# oil and Z-200 at concentrations ranging from 21 to 42 mg/L was fed into an Ozone/Biological activated carbon (BAC) reactor. Analyses of the effluent indicated a chemical oxygen demand (COD) removal over 86.21% and Total organic carbon (TOC) removal over 90.00% were achieved under Hydraulic retention time (HRT) of 4h and O3 feeding concentration of 33.3mg/L. The effluent was further recycled to the lab scale lead concentrating process and no significant difference was found in compare with fresh water. Furthermore, lead-zinc sulphide mineral concentrating process was carried out at lab scale. The produced wastewater was treated by Ozone/BAC reactor at O3 feeding concentration of 16.7mg/L and HRT of 4h. The effluent analysis showed that TOC removal was 74.58%. This effluent was recycled to the lab scale lead-zinc sulphide mineral concentrating process and the recovery of lead was not affected. The results showed that by using Ozone/BAC technology, the lead-zinc sulphide mineral processing wastewater could be recycled.

Survey on Path-Dependent PDEs

In this paper,the authors provide a brief introduction of the path-dependent partial differential equations(PDEs for short)in the space of continuous paths,where the path derivatives are in the Dupire(rather than Fréchet)sense.They present the connections between Wiener expectation,backward stochastic differential equations(BSDEs for short)and path-dependent PDEs.They also consider the well-posedness of path-dependent PDEs,including classical solutions,Sobolev solutions and viscosity solutions.

A strong law of large numbers under sublinear expectations

We consider a sequence of independent and identically distributed(i.i.d.)random variables{ξ_(k)}under a sublinear expectation E=sup_(P∈Θ).We first give a new proof to the fact that,under each P∈Θ,any cluster point of the empirical averages.Next,we consider sublinear expectations on a Polish space,and show that for each constantμ∈[μ,μ^(-)],there exists a probability P_(μ)∈Θsuch thatlim_(n→∞)ξ_(n)=μ,P_(μ-a.s.,(0.1))supposing thatΘis weakly compact and.Under the same conditions,we obtain a generalization of(0.1)in the product space with replaced by.Here is a Borel measurable function on,.Finally,we characterize the triviality of the tail-algebra of the i.i.d.random variables under a sublinear expectation.

Gradient estimates for nonlinear diffusion semigroups by coupling methods

In this paper, we obtain gradient estimates for certain nonlinear partial differential equations by coupling methods. First, we derive uniform gradient estimates for certain semi-linear PDEs based on the coupling method introduced by Wang in 2011 and the theory of backward SDEs. Then we generalize Wang's coupling to the G-expectation space and obtain gradient estimates for nonlinear diffusion semigroups, which correspond to the solutions of certain fully nonlinear PDEs.

非线性期望下的Stein方法

Stein方法是正态逼近的常用方法.本文介绍非线性期望下Stein方法的基本框架,以及如何利用Stein方法给出非线性期望下中心极限定理和大数定律的收敛速度.

Stein’s method for the law of large numbers under sublinear expectations

Peng,S.[6]proved the law of large numbers under a sublinear expectation.In this paper,we give its error estimates by Stein’s method.