Strukturanalytische Untersuchungen an Folgeprodukten aus Sulfonamiden. V. Infrarotspektroskopische und thermoanalytische Untersuchungen an polymorphen Modifikationen von N-substituierten S-Methyl-N′-tosyl-isothioharnstoffen

Structure-Analytical Investigations of Consecutive Products of Sulphonamides. V. Infrared Spectroscopic and Thermoanalytical Studies of Polymorphic Modifications of N-Substituted S-Methyl-N′-tosyl-isothioureas Four compounds ( 1d, 1e, 1h, 1p ) out of twelve N-substituted S-methyl-N′-tosylisothioureas were shown to form polymorphic modifications. Attempts were made to isolate each single specimen and to characterize it by means of differential scanning calorimetry and infrared spectroscopy. The results clearly revealed that both different hydrogen bonding and conformational effects are responsible for the formation of the polymorphic species. With the help of ¹⁵N labeled compounds the presence of the sulphonylimino structure in any modification was proved. The v(NH) and δ_s(SO₂) band positions are used to divide the polymorphs into two groups A and B.     

Oxyntomodulin: a cAMP-dependent stimulus of rat parietal cell function via the receptor for glucagon-like peptide-1 (7-36)NH2

Six patients with hepatocellular carcinoma were subjected to percutaneous microwave coagulation therapy (PMCT) by ultrasonic guiding. The size of the main tumor in the present cases was limited to not more than 2 cm. From 18 to 48 days after PMCT, each patient was subjected to surgery and pathological examination. By macroscopic observation, the PMCT area including both non-tumor and tumor regions looked yellowish white, and the boundary was clearly recognized. In the histological examination, the coagulation area surrounded by fibrous capsule was found, and deletion of nuclei and changes in stainability were observed in the marginal region. These changes indicated obvious coagulation necrosis, but the changes became less intense toward the center in the area, and in some portions, the tissue was indistinguishable from viable cells by light microscopy. In 2 cases out of the 6, part of the tumor remained outside the coagulation area. Since only the area determined by the microwave electrode is coagulated to cause necrosis on PMCT, sufficient safety margin should be required.     

Training birth attendants in the Sahel

A small-scale training programme for birth attendants in a remote area of Burkina Faso was evaluated two years after it had been started. The evaluation methods included interviews with trained birth attendants and the analysis of health service statistics and survey data. The findings showed that the programme had been moderately successful in imparting knowledge and overcoming cultural inhibitions about assisted deliveries. However, the effectiveness of the programme was severely curtailed by structural deficits in the health system, especially lack of skilled staff, supervision and transport. In deprived areas such as the Sahel, it is probably the health centre, the hospital and the referral system that should be the first priority for improvement, rather than grass-roots practices.     

Kontrollierte enzymatische Proteinhydrolyse im Bereich niedriger pH-Werte

Zusammenfassung Es wird eine Methode zur kontrollierten enzymatischen Hydrolyse von Proteinen im pH-Bereich 1,5–3,5 beschrieben. Bei konstantem pH-Wert (pH-stat) kann die bei der Hydrolyse der Peptid-bindung verbrauchte Menge an Säure zur Berechnung des Hydrolysegrades eines vorgegebenen Proteinsubstrates verwendet werden. Die berechneten Hydrolysewerte stimmen gut mit den aus der Zahl der freigesetzten Aminogruppen bestimmten überein. Die Untersuchungen werden mit Rinderserumalbumin als Modellprotein durchgeführt.

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Controlled enzymatic hydrolysis of proteins at low pH values 1. Experiments with bovine serum albumin

Summary A method for the controlled enzymatic hydrolysis of proteins in the pH range 1.5–3.5 is described. The hydrolysis of the peptide bond at a constant pH value (pH-stat) can be followed by the consumption of acid. This value is used for calculating the degree of protein hydrolysis. The degree of hydrolysis is in good accordance with the number of amino groups liberated during the course of hydrolysis. These experiments are carried out using bovine serum albumin as the substrate.

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Herrn Dr. Roland Vogel zum 65. Geburtstag gewidmet     

Bulk Synchronous Parallel Algorithms for the External Memory Model

Abstract. Blockwise access to data is a central theme in the design of efficient external memory (EM) algorithms. A second important issue, when more than one disk is present, is fully parallel disk I/ O. In this paper we present a simple, deterministic simulation technique which transforms certain Bulk Synchronous Parallel (BSP) algorithms into efficient parallel EM algorithms. It optimizes blockwise data access and parallel disk I/ O and, at the same time, utilizes multiple processors connected via a communication network or shared memory. We obtain new improved parallel EM algorithms for a large number of problems including sorting, permutation, matrix transpose, several geometric and GIS problems including three-dimensional convex hulls (two-dimensional Voronoi diagrams), and various graph problems. We show that certain parallel algorithms known for the BSP model can be used to obtain EM algorithms that meet well known I /O complexity lower bounds for various problems, including sorting.     

Parallel ROLAP Data Cube Construction on Shared-Nothing Multiprocessors

The pre-computation of data cubes is critical to improving the response time of On-Line Analytical Processing (OLAP) systems and can be instrumental in accelerating data mining tasks in large data warehouses. In order to meet the need for improved performance created by growing data sizes, parallel solutions for generating the data cube are becoming increasingly important. This paper presents a parallel method for generating data cubes on a shared-nothing multiprocessor. Since no (expensive) shared disk is required, our method can be used on low cost Beowulf style clusters consisting of standard PCs with local disks connected via a data switch. Our approach uses a ROLAP representation of the data cube where views are stored as relational tables. This allows for tight integration with current relational database technology.We have implemented our parallel shared-nothing data cube generation method and evaluated it on a PC cluster, exploring relative speedup, local vs. global schedule trees, data skew, cardinality of dimensions, data dimensionality, and balance tradeoffs. For an input data set of 2,000,000 rows (72 Megabytes), our parallel data cube generation method achieves close to optimal speedup; generating a full data cube of 227 million rows (5.6 Gigabytes) on a 16 processors cluster in under 6 minutes. For an input data set of 10,000,000 rows (360 Megabytes), our parallel method, running on a 16 processor PC cluster, created a data cube consisting of 846 million rows (21.7 Gigabytes) in under 47 minutes.     

Computational geometry algorithms for the systolic screen

Adigitized plane Π of sizeM is a rectangular √M × √M array of integer lattice points called pixels. A √M × √M mesh-of-processors in which each processorP _ij represents pixel (i,j) is a natural architecture to store and manipulate images in Π; such a parallel architecture is called asystolic screen. In this paper we consider a variety of computational-geometry problems on images in a digitized plane, and present optimal algorithms for solving these problems on a systolic screen. In particular, we presentO(√M)-time algorithms for determining all contours of an image; constructing all rectilinear convex hulls of an image (peeling); solving the parallel and perspective visibility problem forn disjoint digitized images; and constructing the Voronoi diagram ofn planar objects represented by disjoint images, for a large class of object types (e.g., points, line segments, circles, ellipses, and polygons of constant size) and distance functions (e.g., allL _p metrics). These algorithms implyO(√M)-time solutions to a number of other geometric problems: e.g., rectangular visibility, separability, detection of pseudo-star-shapedness, and optical clustering. One of the proposed techniques also leads to a new parallel algorithm for determining all longest common subsequences of two words.     

Folgeprodukte aus Sulfonamiden. VI. Darstellung und Cyclisierung von N-Allyl-N′-arylsulfonyl-thioharnstoffen

Consecutive Products of Sulphonamides. VI. Synthesis and Cyclization of N-Allyl-N′-arylsulphonyl-thioureas N-Allyl-N′-arylsulphonyl-thioureas 3a–e are synthesized by addition reaction of substituted arensulphonamides 2a–e and allylisothiocyanate 1 . The thioureas 3a–e react with hydrogen bromide in acetic acid or bromine in chloroform to 2-(arylsulphonylimino)-5-methyl-(or bromomethyl)thiazolidines 8a-j . The mechanism of reaction and the structures are discussed by means of i.r., m.s. and ¹H-n.m.r. data.