scholarly journals Back-exchange of deuterium in neutron crystallography: characterization by IR spectroscopy

2017 ◽  
Vol 50 (2) ◽  
pp. 660-664 ◽  
Author(s):  
Ai Woon Yee ◽  
Matthew P. Blakeley ◽  
Martine Moulin ◽  
Michael Haertlein ◽  
Edward Mitchell ◽  
...  
Keyword(s):  
Quality Control ◽  
Ir Spectroscopy ◽  
Scattering Length ◽  
Systematic Method ◽  
Density Maps ◽  
Back Exchange ◽  
Central Facility ◽  
Neutron Crystallography

The application of IR spectroscopy to the characterization and quality control of samples used in neutron crystallography is described. While neutron crystallography is a growing field, the limited availability of neutron beamtime means that there may be a delay between crystallogenesis and data collection. Since essentially all neutron crystallographic work is carried out using D2O-based solvent buffers, a particular concern for these experiments is the possibility of H2O back-exchange across reservoir or capillary sealants. This may limit the quality of neutron scattering length density maps and of the associated analysis. Given the expense of central facility beamtime and the effort that goes into the production of suitably sized (usually perdeuterated) crystals, a systematic method of exploiting IR spectroscopy for the analysis of back-exchange phenomena in the reservoirs used for crystal growth is valuable. Examples are given in which the characterization of D2O/H2O back-exchange in transthyretin crystals is described.

scholarly journals Interface Refinement of Low-to-Medium Resolution Cryo-EM Complexes using HADDOCK2.4

2021 ◽  
Author(s):  
Tim Neijenhuis ◽  
Siri C. van Keulen ◽  
Alexandre M.J.J. Bonvin
Keyword(s):  
Protein Complexes ◽  
Protein Assemblies ◽  
Cellular Processes ◽  
Protein Interfaces ◽  
Density Maps ◽  
Medium Resolution ◽  
Wide Range ◽  
Multimeric Protein

A wide range of cellular processes require the formation of multimeric protein complexes. The rise of cryo-electron microscopy (cryo-EM) has enabled the structural characterization of these protein assemblies. The produced density maps can, however, still suffer from limited resolution, impeding the process of resolving structures at atomic resolution. In order to solve this issue, monomers can be fitted into low-to-medium resolution maps. Unfortunately, the produced models frequently contain atomic clashes at the protein-protein interfaces (PPIs) as intermolecular interactions are typically not considered during monomer fitting. Here, we present a refinement approach based on HADDOCK2.4 to remove intermolecular clashes and optimize PPIs. A dataset of 14 cryo-EM complexes was used to test eight protocols. The best performing protocol, consisting of a semi-flexible simulated annealing refinement with restraints on the centroids of the monomers, was able to decrease intermolecular atomic clashes by 98% without significantly deteriorating the quality of the cryo-EM density fit.

X-ray diffraction data of tibolone Δ4 isomer (isotibolone)

2009 ◽  
Vol 24 (4) ◽  
pp. 337-342 ◽  
Author(s):  
Selma Gutierrez Antonio ◽  
Fabio Furlan Ferreira ◽  
Gabriel Lima Barros Araujo ◽  
Jivaldo do Rosario Matos ◽  
Carlos de Oliveira Paiva-Santos
Keyword(s):  
Thermal Analysis ◽  
Quality Control ◽  
Ir Spectroscopy ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drug Products ◽  
Synchrotron Light ◽  
Major Degradation Product

Tibolone is used for hormone reposition of postmenopause women and isotibolone is considered the major degradation product of tibolone. Isotibolone can also be present in tibolone API raw materials due to some inadequate synthesis. Its presence is then necessary to be identified and quantified in the quality control of both API and drug products. In this work we present the indexing of an isotibolone X-ray diffraction pattern measured with synchrotron light (λ=1.2407 Å) in the transmission mode. The characterization of the isotibolone sample by IR spectroscopy, elemental analysis, and thermal analysis are also presented. The isotibolone crystallographic data are a=6.8066 Å, b=20.7350 Å, c=6.4489 Å, β=76.428°, V=884.75 Å3, and space group P21, ρo=1.187 g cm−3, Z=2.

Development and Application of Quality Control System for Highway Subgrade Construction

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Detection Method ◽  
System Development ◽  
Effective Control ◽  
Construction Process ◽  
Development Mode ◽  
The Road ◽  
Whole Process

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.

Construction Control As A Strategy For Improving The Quality Of Buildings And Structures

2020 ◽  
Keyword(s):  
Quality Control ◽  
Life Cycle ◽  
Construction Control ◽  
Construction Sites ◽  
Actual Problem ◽  
Construction Market ◽  
Construction Products ◽  
Underlying Causes ◽  
Required Quality

In construction production, the safety of constructing buildings and structures is achieved by ensuring the required quality as a result of systematic construction control based on the implementation of a complex of technical, economic and organizational measures at all stages of the object's life cycle. The article deals with the actual problem of improving the quality of construction products-buildings and structures in conjunction with the activities of construction control bodies. The article presents the advanced foreign and domestic experience of ensuring the quality control at the construction sites, providing for the prevention of the underlying causes of defects and increasing the interest of the contractors directly. On the basis of the analysis of the current situation with quality control at the construction market, ways to improve its efficiency by developing a unified system of technological implementation of relevant requirements for the quality of construction products, determining the rational number and business load of construction control engineers, as well as the active activities of self-regulatory organizations in this area are offered.

68. The resident experience in a large urban teaching setting: Results of the 2005-2006 resident exit survey, University of Torontos

2007 ◽  
Vol 30 (4) ◽  
pp. 66
Author(s):  
N. Tenn-Lyn ◽  
S. Verma ◽  
R. Zulla
Keyword(s):  
Quality Control ◽  
Residency Training ◽  
Royal College ◽  
Online Survey ◽  
Career Guidance ◽  
Training Programs ◽  
Program Planning ◽  
Educational Experience ◽  
Care Experience

We developed and implemented an annual online survey to administer to residents exiting residency training in order to (1) assess the quality of the residency experience and (2) identify areas of strength and areas requiring improvement. Long-term goals include program planning, policy-making and maintenance of quality control. Survey content was developed from an environmental scan, pre-existing survey instruments, examination of training criteria established by the CFPC and the CanMEDS criteria established by the RCPSC. The survey included evaluation benchmarks and satisfaction ratings of program director and faculty, preparation for certification and practice, quality of life, quality of education, and work environment. The response rate was 28%. Seventy-five percent of respondents were exiting from Royal College training programs. Results of descriptive statistics determined that the overall educational experience was rated highly, with 98.9% of respondents satisfied or very satisfied with their overall patient care experience. Ninety-six percent of respondents were satisfied or very satisfied with the overall quality of teaching. Preparation for practice was identified as needing improvement, with 26% and 34% of respondents giving an unsatisfactory rating to career guidance and assistance with finding employment, respectively. Although 80% of respondents reported receiving ongoing feedback and 84% discussed their evaluations with their supervisors, only 38% of evaluations were completed by the end of the rotation. The results indicate that residents are generally satisfied with their experiences during residency training, especially with their overall educational experience. Areas of improvement include preparation for practice and timeliness of evaluations. Further iterations of this survey are needed to refine the instrument, identify data trends and maintain quality control in residency training programs. Frank JR (ed.). The CanMEDS competency framework: better standards, better physicians, better care. Ottawa: The Royal College of Physicians and Surgeons of Canada, 2005. Merritt, Hawkins and Associates. Summary Report: 2003 Survey of final-year medical residents. http://www.merritthawkins.com/pdf/MHA2003residentsurv.pdf. Accessed May 1, 2006. Regnier K, Kopelow M, Lane D, Alden A. Accreditation for learning and change: Quality and improvement as the outcome. The Journal of Continuing Education in the Health Professions 2005; 25:174-182.

Physicochemical and bacteriological characterization of hospital effluents and their impact on the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Human Health ◽  
Fecal Coliforms ◽  
Chemical Pollution ◽  
Hospital Effluents ◽  
Biological Contaminants ◽  
Almost All ◽  
Direct Discharge ◽  
Significant Chemical

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.

Emerging Techniques for the Characterization of Nano-Mechanical Properties of Integrated Circuit Components

2008 ◽  
Author(s):  
Nicholas Randall ◽  
Rahul Premachandran Nair
Keyword(s):  
Mechanical Properties ◽  
Quality Control ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Manufacturing Process ◽  
Solder Bumps ◽  
Initial Work ◽  
Circuit Components ◽  
Materials Used

Abstract With the growing complexity of integrated circuits (IC) comes the issue of quality control during the manufacturing process. In order to avoid late realization of design flaws which could be very expensive, the characterization of the mechanical properties of the IC components needs to be carried out in a more efficient and standardized manner. The effects of changes in the manufacturing process and materials used on the functioning and reliability of the final device also need to be addressed. Initial work on accurately determining several key mechanical properties of bonding pads, solder bumps and coatings using a combination of different methods and equipment has been summarized.

System errors of manufacturers of medicines detected by conducting of state control in the area of circulation of medicines

2019 ◽  
Vol 2019 (5) ◽  
pp. 32-38
Author(s):  
Валентина Косенко ◽  
Valentina Kosenko ◽  
Алла Трапкова ◽  
Alla Trapkova ◽  
Светлана Тарасова ◽  
...  
Keyword(s):  
Quality Control ◽  
Quality Management ◽  
Management Systems ◽  
State Control ◽  
Quality Management Systems ◽  
Conducting State ◽  
Pharmaceutical Quality ◽  
State Quality ◽  
System Errors

The article conducts the analysis of system errors detected by Roszdravnadzor by conducting state quality control of circulating medicines, as well as weaknesses in pharmaceutical quality management systems of the manufacturers, that can influence the quality of manufactured drugs.

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