New One-Generator Quasi-cyclic Codes over GF(7)

Let [n,k,d] _q codes be linear codes of length n, dimension k, and minimum Hamming distance d over GF(q). In this paper, seventeen new codes are constructed, which improve the known lower bounds on minimum distance.     

New Quasi-cyclic Degenerate Linear Codes over GF(8)

Let [n, k, d] _q code be a linear code of length n, dimension k, and minimum Hamming distance d over GF(q). One of the most important problems in coding theory is to construct codes with best possible minimum distances. Recently, quasi-cyclic (QC) codes were proved to contain many such codes. In this paper, twenty-five new codes over GF(8) are constructed, which improve the best known lower bounds on minimum distance.     

Monte Carlo-aided dosimetry of a new high dose-rate brachytherapy source

In this article we introduce a new high-intensity 192Ir source design for use in a recently reengineered microSelectron-HDR remote afterloading device for high dose-rate (HDR) brachytherapy. The maximum rigid length and outer diameter of the new source are reduced to 4.95 and 0.90 mm, respectively, compared to 5.50 and 1.10 mm for the previous source design introduced in 1991. In addition, a smaller diameter and more flexible steel cable are used, allowing the source cable to negotiate smaller diameter catheters or more tortuously curved catheters. Using Monte Carlo photon transport simulation, the complete two-dimensional (2-D) dose-rate distribution is calculated over the 0.1-7 cm distance range and are presented both as conventional 2-D Cartesian lookup tables and in the formalism recommended by the American Association of Physicists in Medicine Task Group 43 (TG-43) Report. The dose distribution of this source is very similar to that of its predecessor, except near the source tip and in the shadow of the cable assembly, where differences of 5%-8% are apparent. The accuracy of various methods for extrapolating beyond the tubulated anisotropy functions to short distances is evaluated. It is demonstrated that linear extrapolation from the anisotropy functions defined by TG-43 accurately (+/- 2%) estimates dose rate at short and long distances lying outside the radial distance range of the original measured data from which the anisotropy and radial dose functions were derived. In contrast, the algorithm used on the vendor's planning system results in large calculation errors at distances less than 5 mm.     

New Minimum Distance Bounds for Linear Codes over GF(9)

Thirty-one new linear codes over GF(9) are constructed, and the nonexistence of thirty codes is proved.     

Late complications in patients having undergone a gastric resection

A total of 37 patients who had undergone partial gastrectomy for duodenal or gastric ulcers, were investigated. The postoperative periods ranged from 5 to 28 years. All the patients were subjected to comprehensive clinical and neurologic examinations. The content of vitamin B12 and folic acid in the blood serum was studied by radioimmunoassay in 29 gastrectomized patients, hematological parameters (hemoglobin, serum iron, red blood cell morphology, proteinogram) were estimated in 19 patients. The mean content of vitamin B12 in the blood serum of patients was lower than in normal subjects. The mean level of folic acid in the blood of patients was also lower than in the control, however, this difference was insignificant. Nine patients had subnormal content of vitamin B12, eight of them showed manifest neurologic complications, such as myelopathy and polyneuropathy. Only 3 patients had subnormal content of folic acid in the blood serum. Weakly pronounced anemic syndrome was detected only in 2 out of 19 patients. The role of vitamin B12 deficiency in the development of neurologic symptoms has been considered.     

Determination of film thickness and refractive index of films and substrates by means of angular modulation in reflection

A method has been developed for determining the refractive index of films and substrates and film thicknesses by exact measurements of the angular positions of extrema in the reflectance curves representing the variation of the reflectance with angle of incidence. The use of the angular modulation technique provides great accuracy and does not require knowledge of the magnitude of the reflectance. The method is applied to Si-SiO₂ systems and to glass surfaces.     

Reduction of Listeria monocytogenes on frankfurters treated with lactic acid solutions of various temperatures

United States regulations require ready-to-eat meat and poultry processors to control Listeria monocytogenes using interventions which may include antimicrobials that reduce post-processing contamination by at least 1 log-cycle; if the treatment achieves ≥2 log reductions, the plant is subject to less frequent microbial testing. Lactic acid (LA) may be useful as a post-lethality intervention and its antimicrobial properties may increase with temperature of application. The aim of this study was to evaluate the effect of LA solution concentration and temperature on L. monocytogenes counts of inoculated frankfurters and to identify parameters (concentration, temperature, and time) that achieve 1 and 2 log-unit immediate reductions. Frankfurters were surface-inoculated with a 10-strain mixture of L. monocytogenes (4.4 ± 0.1 log CFU/cm²) and then immersed in distilled water or LA solutions (0–3%) of 4, 25, 40, or 55 °C for 0–120 s. A regression equation for L. monocytogenes reduction included significant (P < 0.05) effects by the terms of concentration, time, temperature, and the interaction of concentration and temperature; other tested parameters (other interactions, quadratic and cubic terms), within the experimental range examined, did not affect (P ≥ 0.05) the extent of reduction. Results indicated that the effectiveness of LA against L. monocytogenes, in addition to concentration, increased with solution temperature (in the range of 0.6–2.8 log CFU/cm²). The developed equation may allow processors to vary conditions of treatment with LA to achieve a 1 or 2 log-unit reduction of the pathogen and comply with United States regulations.     

The nonexistence of some five-dimensional quaternary linear codes

Let n₄(k, d) be the smallest integer n, such that a quaternary linear [n, k, d; 4]-code exists. It is proved that n₄ (5, 20)=30, n₄(5, 42)⩾59, n₄(5, 45)⩾63, n₄(5, 64)⩾88, n₄(5, 80)=109, n₄(5, 140)⩾189, n₄(5, 143)⩾193, n₄ (5, 168)⩾226, n₄(5, 180)⩾242, n₄(5, 183)⩾246, n₄(5, 187)=251     

Non-invasive electrogastrography. Part 2. Human electrogastrogram

The physiologic stress of various dental procedures (dental examination, dental prophylaxis, restoration, root canal therapy, and tooth extraction) was measured in 50 nonsmoking healthy men between the ages of 18 and 55 years (mean 34.6 years, range 21 to 53 years) with a salivary cortisol assay. Expectorated saliva was collected at four time points: 10 minutes before the start of the procedure, 15 minutes after the patient was seated, at the end of the procedure, and 1 hour after the completion of the procedure. Of the 196 samples included for analysis, mean cortisol values ranged from 0.1 to 3.8 micrograms/dl with a recovery of 100% +/- 8.4%. The mean cortisol value for the extraction group (1.09 +/- 0.42 microgram/dl) was significantly different (p < 0.05) from the mean values of the examination (0.46 +/- 0.10 microgram/dl), prophylaxis (0.64 +/- 0.64 microgram/dl), root canal (0.49 +/- 0.07 microgram/dl), and restorative (0.60 +/- 0.04 microgram/dl) groups as determined by the Duncan's multiple range test. Cortisol levels decreased from the initial reading to the end of the procedure by about 15% for patients undergoing an examination, root canal, and restorative procedure. Cortisol levels at the end of the procedure were elevated in the prophylaxis (55%) and extraction (148%) groups compared with the baseline cortisol recording. A minority of patients in the prophylaxis group had elevated cortisol levels throughout dental treatment, whereas cortisol levels were elevated during treatment in 80% of patients undergoing extraction. These data suggest that the adrenal stress response associated with tooth extraction(s) is greater than that associated with other routine dental procedures.     

Liver resections and operations in portal hypertension viewed via the experience of our practice]

After listing the indications for liver resection, the operative technique used is discussed with a special reference to an original modification implemented in practice. The case material is made of 52 liver resections and 6 lobectomies with a favourable outcome. In one lobectomy with subtotal proximal resection jejunogastroplasty is performed, supplemented by isolated antireflux anisoperistaltically interposed invagination esophagojejunostomy, duplicated by suturing its two portions. Application of catheter, inserted into the recanalized umbilical vein, is described under the heading of locoregional chemotherapy. In carcinomas involving the confluence of hepatic ducts a variant of Rodney Smith's operation is used while in hepatocholedochus resection plastic repair is done over Kerr drainage. In portal hypertension, after discussing the various methods existing, attention is called to the indirect shunts: splenectomy with omentoreno- and omentoparietopexy, Charsky and fenestration of Glisson's capsule using electric knife and argon with omentohepato- and hepatoparietopexy, as well as implantation of the recanalized v. umbilicalis into m. rectus abdominis dexter. In 15 cases operated on by parenchyma stimulating procedures, survivorship ranging from 3 to 26 years is achieved. For the purpose of prophylaxis against cholangiohepatitis and cirrhosis the following operations are performed: 68 papillotomies and plastic repairs over balloon catheter, passed through the choledochus and papilla, using an electric knife, 12 choledochoduodenostomies type "frog mouth", and 11 deperitonizations-desympathizations with a successful cure being attained.