Early and late long--term effects of vasectomy on Zn,Cd, and Cu levels in prostatic fluid and serum

Aim: To evaluate the early and late long-term effects of vasectomy on the serum and prostatic fluid trace elements.Methods: In 37 vasectomized and 25 non-vasectomized (control) men, the Zn, Cd and Cu levels in the serum andprostatic fluid were measured by means of inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Re-suits: No significant difference was found in the prostatic Zn, Cd and Cu levels between the vasectomized and controlgroup. The Zn level in the semm were significantly lower in the vasectomized men than in the controls (11.04 and 13.54 umol/L, respectively; P < 0.05), while the serum Cd and Cu levels were not significantly different between thetwo groups. Conclusion: Vasectomy may decrease the serum, but not the prostatic Zn levels. Its pathophysiologicalsignificance is worthy of further investigation.

The Study of Deposition Parameters, Properties for PVD Ti_xN and Cr_xN Coatings Using a Closed Field Unbalanced Magnetron Sputter Ion Plating System

Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different hard coatings, have been chosen to study the coating process parameters for the CFUBMSIP system. In this paper, the process parameters, such as substrate temperature, substrate bias and OEM control, have been carefully examined to achieve hard and wear-resistance coatings with good adhesion. The coating structure and orientation were found to change according to the coating parameters. The Rockwell test and Scratch test were carried out to examine the coating adhesion; pin-on-disc testing was used to estimate the wear-resistant; micro-hardness was also used to determine coating hardness. HSS drill testing has been carried out to study the general properties of the coating for cutting tool application. A combination of process parameters can be selected to achieve good performance for the TiN and CrN coatings.

Preliminary Clinical Study on Perforating Prosthokeratoplasty

Purpose: To observe the effects of perforating prosthokeratoplasty on patients with leucoma who failed in keratoplasty or were not suitable for keratoplasty, and improved their vision.Methods:Five cases with leucoma (4 with chemical burn and 1 with blast) received Yakimenko Style keratoprosthesis implantation. Preoperative examination showed the visual acuity in 4 of the 5 cases was light perception, and that of the other one was FC/20 crm.The light orientation in 3 patients was definite, and that in the other two was indefinite.Results: The vision improved in 4 of 5 patients in the follow-up period of 9 months to 3 years. Their visual acuity showed 0.09 to 0.8. And there was no change of vision in the other 1 case.Conclutions :Prosthokeratoplasty is the first choice for rehabilitation of the blind that have leucoma but are not suitable for or failed in penetrating keratoplasty.

SINGLE-PERIOD TWO-PRODUCT INVENTORY MODEL WITH SUBSTITUTION:SOLUTION AND PROPERTIES

In this paper, we study a single-period two-product inventory model with stochastic demands and downward substitution. The optimal order quantities are presented and some properties are provided. Comparing with newsboy model, we prove that both the profit and the fill rate can be improved by using the substitution policy.

Entropy,Periodicity,and Graphs with Zero Euler Characteristic

Let G be a graph which contains exactly one simple closed curve.We prove that a continuous map f:G→G has zero topological entropy if and only if there exist at most k■[(Edg(G)+End(G)+ 3)/2]different odd numbers n_1,...,n_k such that Per(f)is contained in ∪_i^k=1 ∪_j~∞=0 n_i2~j,where Edg(G) is the number of edges of G and End(G)is the number of end points of G.

GROUP-BUYING ONLINE AUCTION AND OPTIMAL INVENTORY POLICY IN UNCERTAIN MARKET

In this paper we consider a group-buying online auction (GBA) model for a monopolistic manufacturer selling novel products in the uncertain market. Firstly, we introduce the bidder's dominant strategy, after which we optimize the GBA price curve and the production volume together. Finally, we compare the GBA with the traditional posted pricing mechanism and find that the GBA is highly probable to be advantageous over the posted pricing mechanism in some appropriate market environments.

A CONSTRAINED OPTIMIZATION APPROACH FOR LCP

In this paper, LCP is converted to an equivalent nonsmooth nonlinear equation system H(x,y) = 0 by using the famous NCP function-Fischer-Burmeister function. Note that some equations in H(x, y) = 0 are nonsmooth and nonlinear hence difficult to solve while the others are linear hence easy to solve. Then we further convert the nonlinear equation system H(x, y) = 0 to an optimization problem with linear equality constraints. After that we study the conditions under which the K-T points of the optimization problem are the solutions of the original LCP and propose a method to solve the optimization problem. In this algorithm, the search direction is obtained by solving a strict convex programming at each iterative point, However, our algorithm is essentially different from traditional SQP method. The global convergence of the method is proved under mild conditions. In addition, we can prove that the algorithm is convergent superlinearly under the conditions: M is P0 matrix and the limit point is a strict complementarity solution of LCP. Preliminary numerical experiments are reported with this method.