Two polymorphs of tolazamide, N-[(azepan-1-ylamino)carbonyl]-4-methylbenzenesulfonamide, a sulfonylurea anti-diabetic drug, have different densities and molecular packings. Polymorph II converts into polymorph I in the solid state on heating or via recrystallization if solvent-assisted. The effect of pressure on the two forms and the possibility of a transformation to a denser form on compression have been studied.No phase transitions have been observed in either of the forms in a pentane-isopentane mixture (when no recrystallization is possible). Polymorph II recrystallized partly into a denser polymorph I in methanol at 0.1 GPa, but the transformation stopped at an early stage. Solid state DFT calculations of the two forms as well as conformational landscape investigation in the gas phase were used to rationalize this result. The anisotropic pressure-induced strain of the two polymorphs has been compared in relation to changes in the hydrogen bond geometry and the behavior of stacking interactions. † Electronic supplementary information (ESI) available: Information on tolazamide crystallization in methanol, low-temperature experiments, details of computational techniques and other data for tolazamide polymorphs: summary of the structural data at multiple pressures and temperatures; data on H-bonds and stacking interactions under pressure, parameters of the equations of state, and information on the strain ellipsoids; figures presenting the tolazamide molecule conformational landscape, conformational disorder in form II and pressure dependencies of tolazamide polymorphs' enthalpies. CCDC 1495203-1495210 and 1493069-1493078. For ESI and crystallographic data in CIF or other electronic format see

Despite recent progress in the field of video matting, neither public data sets nor even a generally accepted method of measuring quality has yet emerged. In this paper we present an online benchmark for video-matting methods. Using chroma keying and a reflection-aware stop-motion capturing procedure, we prepared 12 test sequences. Then, using subjective data, we performed extensive comparative analysis of different quality metrics. The goal of our benchmark is to enable better understanding of current progress in the field of video matting and to aid in developing new methods. Formally, matting is an inverse alpha-compositing problem: i.e., given pixel I, we want to find transparency value α ∈ [0; 1], foreground pixel F, and background pixel B so thatThe problem is ill posed yet solvable by considering the affinity of pixels in natural images. Matting of natural images is well studied, and according to [3], natural-image matting algorithms are continuously improving. Video matting is a relatively new research direction that arose recently as available processing power increased. Applied to video, matting has two special requirements: tolerance of sparse user input and temporal coherence of the resulting transparency values.Despite the rising interest, research in the field of video matting is still weakly organized. In fact, many developers estimate the quality of their methods by visual comparison [1,2,4].The two main challenges facing an effective comparison are preparation of the data set and choice of a quality metric. In this paper we address both challenges and describe a benchmark, available at http: //videomatting.com, that provides a comparison, two training sequences with ground-truth transparency, and multiple visualizations for convenient analysis of the comparison results.To prepare the data set (see Figure 1), we imposed four requirements on our test sequences: high quality for the ground-truth transparency, natural appearance, complexity, and diversity. To satisfy the first two requirements, we used two different techniques of foreground-object capture: namely, capture in front of a green screen and sequential photography (stop motion) against different backgrounds. Chroma keying enabled us to obtain alpha mattes of natural-looking objects with arbitrary motion. Nevertheless, this technique cannot guarantee that the alpha maps are natural, because it assumes the screen color is absent from the foreground object (see Figure 2). To get alpha maps that have a very natural appearance, we used the stop-motion method.We designed the following procedure to perform stop-motion capture: an object with a fuzzy edge sits on the platform in front of an LCD monitor. The object rotates in small, discrete steps along a predefined 3D trajectory, controlled by two servomotors connected to a computer. After each step, the digital camera in front of the setup captures the motionless object against a set of background images. At the end of the process, we remove the object, and the camera again captures all of the b...

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We report the crystal structure and crystallization conditions of a first hydrated form of metacetamol (a hemihydrate), C 8 H 9 NO 2 Á0.5H 2 O. It crystallizes from metacetamol-saturated 1:1 (v/v) water-ethanol solutions in a monoclinic structure (space group P2 1 /n) and contains eight metacetamol and four water molecules per unit cell. The conformations of the molecules are the same as in polymorph II of metacetamol, which ensures the formation of hydrogen-bonded dimers and R 2 2 (16) ring motifs in its crystal structure similar to those in polymorph II. Unlike in form II, however, these dimers in the hemihydrate are connected through water molecules into infinite hydrogen-bonded molecular chains. Different chains are linked to each other by metacetamol-water and metacetamol-metacetamol hydrogen bonds, the latter type being also present in polymorph I. The overall noncovalent network of the hemihydrate is well developed and several types of hydrogen bonds are responsible for its formation. research papers Acta Cryst. (2019). C75, 1465-1470 Zemtsova et al. A novel crystal form of metacetamol

Synthesis of (Azidomethyl)phenylboronic Acids. -Novel arylboronic acids (III) are synthesized and the calculations of their geometric and electronic structures are described. -(FEDOROV*, A. Y.; SHCHEPALOV, A. A.; BOL'SHAKOV, A. V.; SHAVYRIN, A. S.; KURSKII, Y. A.; FINET, J.-P.; ZELENTSOV, S. V.; Russ. Chem.

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