797 research outputs found
Carboplatin binding to a model protein in non-NaCl conditions to eliminate partial conversion to cisplatin, and the use of different criteria to choose the resolution limit
Hen egg white lysozyme (HEWL) co-crystallisation conditions of carboplatin
without sodium chloride (NaCl) have been utilised to eliminate partial
conversion of carboplatin to cisplatin observed previously. Tetragonal HEWL
crystals were successfully obtained in 65% MPD with 0.1M citric acid buffer at
pH 4.0 including DMSO. The X-ray diffraction data resolution to be used for the
model refinement was reviewed using several topical criteria together. The
CC1/2 criterion implemented in XDS led to data being significant to 2.0{\AA},
compared to the data only being able to be processed to 3.0{\AA} using the
Bruker software package (SAINT). Then using paired protein model refinements
and DPI values based on the FreeR value, the resolution limit was fine tuned to
be 2.3{\AA}. Interestingly this was compared with results from the EVAL
software package which gave a resolution limit of 2.2{\AA} solely using
crossing 2, but 2.8{\AA} based on the Rmerge values (60%). The
structural results showed that carboplatin bound to only the N{\delta} binding
site of His-15 one week after crystal growth, whereas five weeks after crystal
growth, two molecules of carboplatin are bound to the His-15 residue. In
summary several new results have emerged: - firstly non-NaCl conditions showed
a carboplatin molecule bound to His-15 of HEWL; secondly binding of one
molecule of carboplatin was seen after one week of crystal growth and two
molecules were bound after five weeks of crystal growth; and thirdly the use of
several criteria to determine the diffraction resolution limit led to the
successful use of data to higher resolution.Comment: 14 pages; submitted to Acta Cryst D Biological Crystallography
reference number tz504
Про що може розповісти стара фотографія?
Автор, зіставлячи написи на світлинах із фондів Ніжинського краєзнавчого музею імені Івана Спаського та біографічну інформацію з архівних й історіографічних джерел, встановлює особи зафіксованих зображень художників Олександра Беклемішева та Якова Голдблата, а також ніжинського професора Івана Турцевича, характеризуючи ступінь та характер їх взаємин.Автор, сопоставляя надписи на фотографиях из фондов Нежинского краеведческого музея имени Ивана Спасского и биографическую информацию из архивных и историографических источников, устанавливает особы зафиксированных изображений художников Александра Беклемишева и Якова Голдблата, а также нежинского профессора Ивана Турцевича, характеризуя степень и характер их взаимоотношений.An author, comparing inscriptions on pictures from the funds of the Nizhyn Regional Museum by Ivan Spas’kiy and biographic information from the archiv and historiography sources, sets person fixed at the pictures as peinterman Alexander Beklemishev, Jacob Goldblat and professor from Nizhyn Ivan Turtsevych, characterizing a degree and character of their mutual relations
Optimizing experimental parameters for the projection requirement in HAADF-STEM tomography
Tomographic reconstruction algorithms offer a means by which a tilt-series of transmission images can be combined to yield a three dimensional model of the specimen. Conventional reconstruction algorithms assume that the measured signal is a linear projection of some property, typically the density, of the material. Here we report the use of multislice simulations to investigate the extent to which this assumption is met in HAADF-STEM imaging. The use of simulations allows for a systematic survey of a range of materials and microscope parameters to inform optimal experimental design. Using this approach it is demonstrated that the imaging of amorphous materials is in good agreement with the projection assumption in most cases. Images of crystalline specimens taken along zone-axes are found to be poorly suited for conventional linear reconstruction algorithms due to channelling effects which produce enhanced intensities compared with off-axis images, and poor compliance with the projection requirement. Off-axis images are found to be suitable for reconstruction, though they do not strictly meet the linearity requirement in most cases. It is demonstrated that microscope parameters can be selected to yield improved compliance with the projection requirement
The effects of instructional focus and task type on pre-vocational learners’ ability in EFL oral interaction
Analyzing Empowerment Processes Among Cancer Patients in an Online Community: A Text Mining Approach
Morbidity and complications of bone grafting of the floor of the maxillary sinus for the placement of endosseous implants.
Placement of endosseous implants in the atrophic maxilla is often limited because of a lack of supporting bone. A technique to augment the floor of the maxillary sinus with autogenous bone graft seems to be a new reliable treatment modality. The morbidity and complication rate of augmentation of the maxillary sinus floor was studied in 75 patients. The sinus floor was augmented with iliac crest (n = 65, 128 sinuses, 276 implants), mandibular symphysis (n = 8, ten sinuses, 21 implants), or maxillary tuberosity grafts (n = 2, two sinuses, two implants). The width of the alveolar crest had to be reconstructed in 52 patients, while in the other 23 patients augmentation and implantation were performed simultaneously. Perforation of the sinus membrane occurred in 45 patients, but this did not predispose them to the development of sinusitis. Loss of bone particles and sequesters were observed in one (diabetic) patient only, in whom a mucosal dehiscence occurred. A second augmentation procedure was successful. Symptoms of transient sinusitis were observed in two of the seven patients with a predisposition for sinusitis. These symptoms were successfully treated with decongestants and antibiotics. One patient developed a purulent sinusitis which resolved after a nasal amrostomy. The bone volume was sufficient for insertion implants in all patients. Twenty of 299 patients (6.7%) in whom Brånemark implants had been inserted were lost to follow-up (mean, 32 months); no sinus pathology was observed. The patients received implant-supported overdentures (58 patients) or fixed bridges (17 patients) and experienced no complaints with regard to the grafts or implants. We conclude that the morbidity and complication rate of bone grafting of the floor of the maxillary sinus floor with autogenous bone is low.</p
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