Topical nitroglycerin in the management of anal fissure: an explosive outcome!

Anal sphincter spasm is a common finding in patients with anal fissure disease. It is postulated that spasm impedes mucosal blood flow and impairs healing. Topical nitroglycerin (NTG), a nitric oxide donor compound, has been shown to cause relaxation of the anal sphincter and may have treatment efficacy in the management of anal fissure. The purpose of this study was to assess the usefulness of NTG for anal fissure. We performed a retrospective review of patients with anal fissure treated with various concentrations of topical NTG ointments over an 18-month period ending July 1997. Of the 81 patients studied, 44 (54%) were male. There were 42 acute and 39 chronic fissures. NTG preparations included 1 per cent isosorbide (n = 37), 0.2 per cent NTG (n = 38), and 0.5 per cent NTG (n = 6). Healing with NTG therapy occurred in 29 acute (69%) and 21 chronic fissure (54%) patients. There was no difference in the incidence of healing of acute or chronic fissure between the various NTG treatment preparation groups. When acute and chronic fissure therapy was subdivided by time of NTG treatment (immediate versus post-conservative therapy failure (PCF)), 14 (74%) of acute PCF and 5 (42%) of chronic PCF patients healed. We conclude that no single formula was superior. When patients were subdivided into a PCF group, NTG therapy demonstrated a significant salvage rate, thus avoiding surgery.     

Ribosomal proteins neighboring 23 S rRNA nucleotides 803-811 within the 50 S subunit

We report the synthesis of a radioactive, photolabile oligodeoxyribonucleotide probe and its exploitation in identifying 50 S ribosomal subunit components neighboring its target site, nucleotides 803-811 in 23 S rRNA. Photolysis of the complex formed between the probe and 50 S subunits leads to site-specific probe photoincorporation into proteins L15, L17, and L20, labeled to greater extents, and L13 and L21, labeled to lesser extents. Portions of each of these proteins thus lie within 23 A of nucleotide U803. These results lead us to conclude that nucleotides 803-811 fall on the side of the L13-L17-L20-L21 protein cluster [Walleczek et al. (1988) EMBO J. 7, 3571-3576] that points from the back of the 50 S particle toward the peptidyl transferase center within the 50 S subunit. Such placement is consistent with the observation that an oligoDNA probe directed to nucleotides 803-811 decreases P-site binding of tRNA [Hill et al. (1990) Biochim. Biophys. Acta 1050, 45-50].     

Design and synthesis of a tetrahydropyran-based inhibitor of mammalian ribonucleotide reductase

A tetrahydropyran-based inhibitor (2) of mammalian ribonucleotide reductase (mRR) has been designed and synthesized based on the heptapeptide, N-AcFTLDADF (1), corresponding to the C-terminus of the R2 subunit of mRR. Inhibition studies revealed that 2 is indeed a competent inhibitor, albeit less potent than 1.     

Wide bandwidth time-domain electromagnetic sensor for metal targetclassification

A portable, wide bandwidth, time-domain electromagnetic sensor system has been developed and used extensively to measure the eddy current time-decay response of a wide variety of metal targets. The sensor has demonstrated the ability to measure metal target decay times starting approximately 3 to 5 μs after the transmitter current is turned off and target decay time constants as short as 1.4 μs. The sensor has demonstrated the potential for detecting very low-metal content mines due to the void they create in some types of electrically lossy soils. The development of the sensor is described in detail, and time-decay data are shown for a variety of metal targets, including low metal antitank and antipersonnel mines     

Differential effects of positive and negative reinforcement on two psychoanalytic character types.

Attempted to replicate the study of C. Noblin, E. Timmons, and H. Kael which related verbal conditioning to performance on the blacky test. It was found that acquisition and extinction procedures affected oral ss in a direction opposite to their effect on anal ss. The effects of mechanical as well as personal reinforcement were studied in the verbal conditioning of 16 oral and 16 anal male undergraduates. The acquisition and extinction differences between oral and anal scoring types were not obtained with either personal or mechanical reinforcement. Differences between the 2 studies and their effects upon the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CMOS gigabit-per-second switching

An analysis and experimental results for a 600-Mb/s 1.2-μm CMOS space switch chip are provided. The high bit rate is achieved with a tree architecture, which is relatively insensitive to on-chip stray capacitance. Computer simulations indicate that bit rates in excess of 1 Gb/s are achievable with 1-μm CMOS and circuit/layout optimization. An obstacle to achieving high bit rate is crosstalk, which is primarily caused by chip packaging and not by the chip itself. Even the best discrete packaging technologies result in excessive crosstalk when 32 outputs switch simultaneously at 600 Mb/s. Tolerable crosstalk was achieved by limiting outputs to two per power supply pin. A major increase in bit rate can be obtained by switching bytes (8 b parallel) of information. This requires on-chip information storage and reclocking to maintain synchronization between the eight parallel bits. Experiments with a second-generation synchronous switch chip have demonstrated switching at 311 MB/s, which corresponds to an STS-48 rate of 2.488 Gb/s     

Mining Frequent Generalized Itemsets and Generalized Association Rules Without Redundancy

This paper presents some new algorithms to efficiently mine max frequent generalized itemsets （g-itemsets） and essential generalized association rules （g-rules）. These are compact and general representations for all frequent patterns and all strong association rules in the generalized environment. Our results fill an important gap among algorithms for frequent patterns and association rules by combining two concepts. First, generalized itemsets employ a taxonomy of items, rather than a flat list of items. This produces more natural frequent itemsets and associations such as （meat, milk） instead of （beef, milk）, （chicken, milk）, etc. Second, compact representations of frequent itemsets and strong rules, whose result size is exponentially smaller, can solve a standard dilemma in mining patterns： with small threshold values for support and confidence, the user is overwhelmed by the extraordinary number of identified patterns and associations; but with large threshold values, some interesting patterns and associations fail to be identified. Our algorithms can also expand those max frequent g-itemsets and essential g-rules into the much larger set of ordinary frequent g-itemsets and strong g-rules. While that expansion is not recommended in most practical cases, we do so in order to present a comparison with existing algorithms that only handle ordinary frequent g-itemsets. In this case, the new algorithm is shown to be thousands, and in some cases millions, of the time faster than previous algorithms. Further, the new algorithm succeeds in analyzing deeper taxonomies, with the depths of seven or more. Experimental results for previous algorithms limited themselves to taxonomies with depth at most three or four. In each of the two problems, a straightforward lattice-based approach is briefly discussed and then a classificationbased algorithm is developed. In particular, the two classification-based algorithms are MFGI_class for mining max frequent g-itemsets and EGR_class for mining essential g-rules. The classification-based algorithms are featured with conceptual classification trees and dynamic generation and pruning algorithms.     

Back Corona and Relaxation Time

Where the resistivity of a precipitated layer of dust exceeds a value in the neighborhood of 108 ?m, the phenomenon of back corona generally occurs. The fact that this is not always the case, however, shows that the phenomenon is not perfectly understood. In 1965, the author introduced to the theory the additional factor of the dielectric constant. This had the effect of making relaxation time the fundamental parameter of back corona, rather than resistivity alone. As a result, it is shown that back corona probably depends on conditions in the gas as well as in the dust.     

New resinous ricinoleic polyol for urethane reactions

A new resinous polyol has been described based on a fusion reaction of Epon Resin 829 with Bisphenol A and further esterification with ricinoleic acid. This was based on a modified short oil alkyd cook reaction with unsaturated fatty acids following previously employed techniques. The method was modified by reaction with ricinoleic acid, a 12-hydroxy oleic acid, the main fatty acid component of castor oil. The resinous polyol derived from this technology is designated Ester 597. Ester 597 was further reacted with a series of urethane prepolymers based on castor oil. A two-component formula based on this study was used to prepare a two-can epoxy-urethane coating system that may have coatings potential as a marine coating and as a maintenance coating for industrial use.