The putative tumor suppressor gene on chromosome 5q for hepatocellular carcinoma is distinct from the MCC and APC genes

We have previously shown that the tumor suppressor gene for hepatocellular carcinoma (HCC) without cirrhosis may be located on chromosome 5q35-qter. In this study, we analyzed nine cases of primary HCC without cirrhosis using probes from the MCC and APC genes, which are in the region 5q21-22. None of the informative cases had allele loss detected by these probes, whereas the probe lambda MS8 for the region 5q35-qter showed allele loss in six out of six informative cases. The results confirm that the putative tumor suppressor gene for HCC without cirrhosis on chromosome 5q is distinct from the MCC and APC genes.     

Symbolic solution of the multiconductor transmission-line equationsfor lines containing shielded wires

The multiconductor transmission line equations that characterize crosstalk in a multiconductor transmission line containing a shielded wire are solved in symbolic form, that is, the resulting crosstalk voltages are determined in terms of symbols rather than numerical values. The resulting solutions show the frequency range for which the widely used, low-frequency, inductive-capacitive coupling model is a valid representation. The solution shows that the inductive-capacitive coupling model is an adequate characterization of crosstalk for lines that are electrically short and whose termination impedances do not differ substantially from the characteristic impedances of the lines that are involved. For lines whose termination impedances differ drastically from the line characteristic impedances, the inductive-capacitive coupling model is valid only for frequencies where the line is extremely short, electrically. For higher frequencies of excitation, the model may give predictions that are substantially below the true crosstalk even for frequencies where the line is electrically short     

Observations of slip patterns on the surface of fatigued gold using the scanning tunnelling microscope

Observations of fatigue-induced slip patterns on the surface of polycrystalline gold (+99.9%) using the scanning tunnelling microscope (STM) are presented. The samples were cycled in four-point bending between zero and 0.0025 strain for 250 and 2500 cycles. STM observations of the sample fatigued for 250 cycles revealed broad slip bands 0.38–0.69 m wide containing narrow slip bands 0.015–0.123 m wide and fine slip lines 0.006 m wide. The depth of these features are 20–57 nm for broad slip bands, 3–7 nm for narrow slip bands, and approximately 2–4 nm for fine slip lines. The sample fatigued for 2500 cycles showed similar values for the width of the slip bands and slip lines except that their depth was increased by a factor of between 2 and 4 times for the narrow slip bands and the fine slip lines. Apparent persistent slip bands (PSBs) spaced 2.4 m, 300–500 nm deep were also observed. These results demonstrate that STM is a significant new tool for observing and distinguishing various types of fatigue-induced surface slip patterns on suitably prepared samples. The vertical resolution obtained with STM is vastly superior to current SEM and TEM methods.     

On the formation of fatigue striations

Thin foils of an aluminium alloy containing the fracture surface were studied in the electron microscope. The fatigue striations were visible due to thickness contrast and bands of dislocations. Supplementary etch pit studies and stereographic measurements were carried out. In many cases the crack plane was close to (100) or (110). The mechanism of fatigue crack propagation is discussed in the light of the new evidence.     

Clutter return from vegetated areas

An analytical stochastic model to predict relevant statistical scattering features of electromagnetic waves propagating within vegetated environments is presented. The propagation phenomena are described by formulating the scattering associated with random permittivity fluctuations superimposed on a lossy deterministic background slab. The distorted wave Born approximation is employed to determine the backscattered power, and its temporal spectrum.     

Scale-up of lithium rechargeable batteries

Small-size lithium rechargeable cells in an envelope format were reported at the 20th International Power Sources Symposium [1,2]. This design offers the possibility of making cells using much lighter packing than cells with metal cans. The prismatic format allows good packing in rectangular boxes. Hence they offer the potential for high gravimetric and volumetric energy densities. The cells have now been developed to a size sufficient to form components of a large battery, built to power Army man-portable equipment. Lithium-ion cells have been manufactured using lithium cobalt oxide cathodes and other cathode materials are under investigation. Individual cells up to the 3 A h size have been successfully cycled, with further development possible. A 24 V battery has been constructed and its performance and prospects are described.     

Data security-bad code

A tutorial on viruses, worms, bacteria, and other computer diseases is presented. It describes how experts classify the various forms of malicious code at work today, the ways in which they hide and work their mischief, and a few of the infamous incidents-such as the attack on the Internet network, in the fall of 1988, of a worm program that devoured massive amounts of CPU time-that have gained international notoriety. Some of the basic forms of prevention and cure are discussed