The seventh blind test of crystal structure prediction: structure generation methods.

A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems of varying complexity: a silicon and iodine-containing molecule, a copper coordination complex, a near-rigid molecule, a cocrystal, a polymorphic small agrochemical, a highly flexible polymorphic drug candidate, and a polymorphic morpholine salt. In this first of two parts focusing on structure generation methods, many crystal structure prediction (CSP) methods performed well for the small but flexible agrochemical compound, successfully reproducing the experimentally observed crystal structures, while few groups were successful for the systems of higher complexity. A powder X-ray diffraction (PXRD) assisted exercise demonstrated the use of CSP in successfully determining a crystal structure from a low-quality PXRD pattern.

A general force field by machine learning on experimental crystal structures. Calculations of intermolecular Gibbs energy with FlexCryst.

Machine learning was employed on the experimental crystal structures of the Cambridge Structural Database (CSD) to derive an intermolecular force field for all available types of atoms (general force field). The obtained pairwise interatomic potentials of the general force field allow for the fast and accurate calculation of intermolecular Gibbs energy. The approach is based on three postulates regarding Gibbs energy: the lattice energy must be below zero, the crystal structure must be a local minimum, and, if available, the experimental and the calculated lattice energy must coincide.

The impact of cryopreservation on the morphology of spermatozoa in men with oligoasthenoteratozoospermia.

The cryopreservation of ejaculate can reduce the viability, motility, and morphological characteristics of the spermatozoa of infertile men. Oligoasthenoteratozoospermia (OAT) is the most common cause of male subfertility. The aim of this study was to evaluate the morphological characteristics and viability of progressive motile sperm fraction before and after cryopreservation, and to determine whether cryopreservation of progressive motile sperm fraction is effective in eliminating morphologically abnormal sperm in men with OAT.

Effect of Pectins on Water Crystallization Pattern and Integrity of Cells During Freezing.

The ability of various pectin polysaccharides to modify the morphological structure of ice during the phase transitions from water to ice was studied. Pectins were isolated from Sosnowsky's hogweed Heracleum sosnowskyi Manden (heracleuman-N6HS), tansy Tanacetum vulgare L. (tanacetan-N7TVF), and Rauwolfia serpentina Benth callus (rauwolfian-N8RS).

Towards biobanking technologies for natural and bioengineered multicellular placental constructs.

Clinical application of a large variety of biomaterials is limited by the imperfections in storage technology. Perspective approaches utilizing low-temperature storage are especially challenging for multicellular structures, such as tissues, organs, and bioengineered constructs. Placenta, as a temporary organ, is a widely available unique biological material, being among the most promising sources of various cells and tissues for clinical and experimental use in regenerative medicine and tissue engineering.