Using titanium plate or meshplate for chest wall reconstruction: report of 6 cases and literature review

Titanium plate has been widely used in several surgical fields, such as craniofacial reconstruction and orthopedic prosthesis. This prosthesis has been proved not only with good biocompatibility and mechanical strength, but also with light weight and low radiological interference. From October 1991 to May 1995, 6 patients underwent thoracic cage reconstruction with titanium plate in our hospital. They included 5 females and 1 male, with ages ranging from 26 to 62 years. Four of them suffered from primary chest wall tumors (2 desmoid tumors, a chondrosarcoma, and 1 hemangioma), one had a recurrent chest wall tumor from breast carcinoma, and one had thoracic hypoplasia. The thoracic cage defect ranged from 5 x 6 cm to 10 x 15 cm, and 1 to 3 titanium plates were used for the reconstruction. No paradoxical movement or other prosthesis-related complications have occurred during the follow-up period. We conclude that titanium plate is a good material for thoracic cage reconstruction.     

Structure of the cyclin-dependent kinase inhibitor p19Ink4d

In cancer, the biochemical pathways that are dominated by the two tumour-suppressor proteins, p53 and Rb, are the most frequently disrupted. Cyclin D-dependent kinases phosphorylate Rb to control its activity and they are, in turn, specifically inhibited by the Ink4 family of cyclin-dependent kinase inhibitors (CDKIs) which cause arrest at the G1 phase of the cell cycle. Mutations in Rb, cyclin D1, its catalytic subunit Cdk4, and the CDKI p16Ink4a, which alter the protein or its level of expression, are all strongly implicated in cancer. This suggests that the Rb 'pathway' is of particular importance. Here we report the structure of the p19Ink4d protein, determined by NMR spectroscopy. The structure indicates that most mutations to the p16Ink4a gene, which result in loss of function, are due to incorrectly folded and/or insoluble proteins. We propose a model for the interaction of Ink4 proteins with D-type cyclin-Cdk4/6 complexes that might provide a basis for the design of therapeutics against cancer. The sequences of the Ink4 family of CDKIs are highly conserved     

Clinical and microbiological characteristics of Flavobacterium indologenes infections associated with indwelling devices

Clinical infections caused by Flavobacterium indologenes have never been documented. Thirteen isolates derived from seven patients with indwelling device-associated F. indologenes infections were identified from 1 April through 30 November 1995. The antimicrobial susceptibilities to 20 antimicrobial agents of the isolates, the cellular fatty acid chromatograms for the isolates, and the random amplified polymorphic DNA (RAPD) patterns generated by arbitrarily primed PCR of the isolates were studied. The antibiotypes and RAPD patterns differed among the isolates recovered from different patients. However, both antibiotypes and RAPD patterns were identical among the five isolates from one patient with multiple episodes of central venous catheter-associated bacteremia within a 1.5-month period and between the two isolates from another patient suffering from two episodes of catheter-related bacteriuria at an interval of 14 days. It is documented that the recurrent infections in each of these two patients were caused by a single F. indologenes clone, respectively. Identical antibiotypes and RAPD patterns were also demonstrated between two isolates from a patient with ventilator-associated pneumonia, one recovered from an endotracheal aspirate and the other derived from a blood specimen 10 days later, indicating the invasive nature of F. indologenes. Two cellular fatty acid chromatograms were identified among these isolates. All of the isolates showed in vitro resistance to cephalothin, cefotaxime, ceftriaxone, moxalactam, aztreonam, aminoglycosides, erythromycin, clindamycin, vancomycin, and teicoplanin. F. indologenes should be included as an etiologic agent of infections associated with the use of indwelling devices.     

Testing consistency of vapor-liquid equilibrium data in P-T-X space

A systematic method of calculating and presenting the results of consistency tests is given and illustrated on the methane-ethane system in the space of ?140 to 60°F and 100 to 700 psia. The results indicate incompatibility of error levels between isobars and isotherms. Also, different arrangements of terms in the thermodynamic differential equations were sometimes found to produce different levels of inconsistency for the same space. Results are analyzed and discussed.     

Suboptimal controls that maximize the probability of entering a target manifold

A suboptimal control scheme is developed for a linear time-dependent process subject to additive random disiturbances. An open-loop control law is chosen from a one-parameter class to optimize the tradeoff between control energy expenditure and the probability of entering a given target set. The computation is done by means of a digital computer simulation.     

An approximate minimal time closed-loop controller for processes with bounded control amplitudes and rates

This paper presents a method for designing an approximate minimal time closed-loop controller for linear systems with bounded control amplitudes and rates. The method is based on obtaining an approximate functional expression (explicitly in terms of the state variables) that describes the minimal time isochrones of the system. This expression is obtained by a series of least-squares fits to the computed system states on the various isochrones. The computation of the system states on the isochrones and the determination of the approximate expressions are achieved off-line. For on-line operation, it is only required to store a limited number of coefficients of the approximate expressions, and to compute the closed-loop control function by some algebraic manipulation. Consequently, the on-line computer storage requirement as well as the on-line computation requirement is relatively small. Thus, the method is feasible for high-order practical systems. To evaluate its usefulness in applications, the scheme is used to design a fourth-order Ranger Block III Attitude Control System. The results are compared to those obtained by applying the minimal time open-loop control.     

The shape parameter in the Gaussian function II

This is a continuation of our former study, Luh [1], of the shape parameter $\beta$ contained in Gaussian $e^{?\beta |x{|}^2}$, $x\in R^n$. Instead of using the error bound presented by Madych and Nelson [2], here we adopt an improved error bound constructed by Luh to evaluate the influence of $\beta$ on error estimates. This results in a new set of criteria for the optimal choice of $\beta$ and much sharper error estimates for Gaussian interpolation. What is important is that the notorious ill-conditioning of Gaussian interpolation can be greatly relieved because in this approach the fill distance need not be very small.     

Using hotspot analysis to establish non-equidistant cooling channels automatically

ABSTRACT

In the injection molding (IM) process, the primary factor that affects product quality and production cycle time is the position of cooling channels; thus, this study has proposed a non-equidistant cooling channel (CC). This was calculated based on the heat difference of the plastic product after filling. In any part of the surface with high temperature, channels (center) were constructed close to the product, whereby the affected area was relatively small. Conversely, channels (center) were built far from the product in parts with low temperature, with the affected area being relatively large. This study applied this idea and used a self-designed application programming interface (API) to automatically establish the paths of non-equidistant cooling channels. The proposed cooling channels were input to Moldflow, after being compared with conventional and conformal channels, the proposed channel successfully reduced the maximum average temperature and temperature differences, thereby effectively enhancing the cooling efficiency and product quality.     

Equivalent hyperboloid (ellipsoid) and its application

Analogous to the equivalent paraboloid, the equivalent hyperboloid (ellipsoid) for dual quadratic surface reflector antennas is derived. The condition that the equivalent reflector is center fed is also derived. The numerical example shows that a reflector geometry that satisfies this center fed condition is a good initial antenna geometry to design a shaped dual reflector antenna     

High quality interpoly dielectrics deposited on thenitrided-polysilicon for nonvolatile memory devices

High quality interpoly dielectrics have been fabricated by using NH₃ and N₂O nitridation on polysilicon and deposition of tetra-ethyl-ortho-silicate (TEOS) oxide with N₂O annealing. The surface roughness of polysilicon is improved and the value of weak bonds is reduced due to nitrogen incorporation at the interface, which improves the integrity of interpoly dielectrics. The improvements include a higher barrier height, breakdown strength, and charge-to-breakdown, and a lower leakage current and charge trapping rate than counterparts. It is found that this method can simultaneously improve both charge-to-breakdown (up to 20 C/cm² ) and electric breakdown field (up to 17 MV/cm)