Diffraction (X-ray, neutron and electron) and electron cryo-microscopy are powerful methods to determine three-dimensional macromolecular structures, which are required to understand biological processes and to develop new therapeutics against diseases. The overall structure-solution workflow is similar for these techniques, but nuances exist because the properties of the reduced experimental data are different. Software tools for structure determination should therefore be tailored for each method. Phenix is a comprehensive software package for macromolecular structure determination that handles data from any of these techniques. Tasks performed with Phenix include data-quality assessment, map improvement, model building, the validation/rebuilding/refinement cycle and deposition. Each tool caters to the type of experimental data. The design of Phenix emphasizes the automation of procedures, where possible, to minimize repetitive and time-consuming manual tasks, while default parameters are chosen to encourage best practice. A graphical user interface provides access to many command-line features of Phenix and streamlines the transition between programs, project tracking and re-running of previous tasks.

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Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix

비만아 부모의 돌봄 경험: q 방법론

High-density microfluidic chips contain plumbing networks with thousands of micromechanical valves and hundreds of individually addressable chambers. These fluidic devices are analogous to electronic integrated circuits fabricated using large scale integration (LSI). A component of these networks is the fluidic multiplexor, which is a combinatorial array of binary valve patterns that exponentially increases the processing power of a network by allowing complex fluid manipulations with a minimal number of inputs. These integrated microfluidic networks can be used to construct a variety of highly complex microfluidic devices, for example the microfluidic analog of a comparator array, and a microfluidic memory storage device resembling electronic random access memories.

https://science.sciencemag.org/content/sci/298/5593/580.full.pdf

Microfluidic large scale integration

We survey progress over the past 25 years in the development of microscale devices for pumping fluids. We attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropump for a particular application. Reciprocating displacement micropumps have been the subject of extensive research in both academia and the private sector and have been produced with a wide range of actuators, valve configurations and materials. Aperiodic displacement micropumps based on mechanisms such as localized phase change have been shown to be suitable for specialized applications. Electroosmotic micropumps exhibit favorable scaling and are promising for a variety of applications requiring high flow rates and pressures. Dynamic micropumps based on electrohydrodynamic and magnetohydrodynamic effects have also been developed. Much progress has been made, but with micropumps suitable for important applications still not available, this remains a fertile area for future research.

https://microfluidics.stanford.edu/Publications/Micropumps_Cooling/Laser%20Review%20of%20Micropumps%20in%20JMM.pdf

A review of micropumps

Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.

X-Ray Diffraction

Microcomponents are increasingly applied in industrial products, e.g. smallest gears, springs or the watch industry. Apart from their small dimensions, such components are characterized by a high contour accuracy. Industry requires the tolerances to be in the µm range. Measurement of lateral dimensions in the mm range with submicrometer accuracy and precision, however, results in high requirements on measurement technology. The relevance of this problem is illustrated by the fact that the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) has launched the Collaborative Research Center 1159 on 'New Strategies of Measurement and Inspection for the Production of Microsystems and Nanostructures'. The Institut fur Mikrostrukturtechnik, Karlsruhe (Institute of Microstructure Technology, Karlsruhe), produces microstructures by means of the LIG(A) technique (German acronym for lithography, electrodeposition, molding). Presently, a coordinate measurement machine equipped with an optical fiber probe to measure these microstructures is being tested. This paper will particularly focus on the precision and accuracy of the machine. The rules of measurement system analysis will be applied for this purpose. Following the elimination of the systematic error, reproducibility of deep-etch x-ray lithography will be highlighted using the LIGA production of gold gears as an example.

Metrology study of high precision mm parts made by the deep x-ray lithography (LIGA) technique

The $5p$ photoemission spectrum of atomic europium has been analyzed using high-resolution photoelectron spectroscopy. In contrast to the expected simple multiplet structure of a ${5p}^{\ensuremath{-}1}{4f}^{7}{(}^{8}S)$ configuration with six main lines, the observed Eu $5p$ photoemission shows a very complex spectrum. Configuration-interaction calculations reveal that the $5p$ core hole gives rise to a near degeneracy of the valence subshells in the final ionic states, so that the main multiplet structure of the spectrum can only be described by a strong mixture of the configurations ${6s}^{2},$ $6s5d,$ ${5d}^{2},$ and ${6p}^{2}.$ This mixing also results in a strong broadening of the lines at higher binding energy.

Core-hole-induced degeneracy of the valence subshells in the 5p photoemission of atomic europium

The invention relates to a phase shifting device (42') for stabilizing radially or azimuthally polarized laser radiation within a laser resonator (40') that comprises a polarizer device (42') for generating radially or azimuthally polarized laser radiation (3a, 3b). The phase shifting device (42') is designed to generate a phase difference (Δφ) ranging from about 30° to about 330°, preferably from about 70° to about 290°, especially preferably from about 160° to about 200°, particularly a phase difference (Δφ) of about 180° per revolution in the laser resonator (40') while having an axial symmetry. The invention further relates to a laser resonator (40') comprising such a phase shifting device (42').

Phase shifting device, and laser resonator for generating radially or azimuthally polarized laser radiation

Shake-up satellites accompanying the inner shell ionization of alkali atoms

DNQ-Novolak based photoresists are applied in many fields of microstructure technology. A common feature of such resist structures (>10 micrometer) described in the literature is a concave profile with the narrowest part at approximately 2/3 of the resist height. By newly including effects of residual solvent concentration, the simulation program accurately describes characteristic resist profiles for AZ4562 between 10 and 100 micrometer resist thickness. The program calculates the vertical distribution of the residual solvent concentration by modeling the evaporation during prebake as a three step process: diffusion of solvent within the resist film to the surface, a transfer to the ambient air described by a phase equilibrium and a transport away from the surface described by convection. Required parameters of the model have been obtained by fitting measured evaporation rates as function of time with the prebake temperature as a parameter to calculated ones. Resist exposure is simulated in vertical and one lateral dimension using the well known Dill's theory with ABC-parameters for DNQ resists. The development process is described by percolation theory where the residual solvent concentration increases the percolation parameter and therefore the local development rate. This paper describes details of the mathematical models used, demonstrates good agreement between experimentally observed profiles and simulated ones and shows that the influence of process parameters such as prebake temperature or time on resist profiles can be accurately simulated.

Joachim Schulz

Papers

Metrology study of high precision mm parts made by the deep x-ray lithography (LIGA) technique

Core-hole-induced degeneracy of the valence subshells in the 5p photoemission of atomic europium

Phase shifting device, and laser resonator for generating radially or azimuthally polarized laser radiation

Shake-up satellites accompanying the inner shell ionization of alkali atoms

Simulation of structure profiles in optical lithography of thick DNQ-novolak-based photoresists