Application of Pulsating Vacuum Cleaning Technology to Medical Devices Cleaning

This study aims to solve existing problems in cleaning medical devices, such as the cumbersome loading of minimally invasive surgical instruments, the incomplete cleaning of instruments with complex structures, and the low cleaning efficiency of ordinary instruments. A pulsating vacuum cleaning machine was combined with ultrasonic cleaning and boiling cleaning technology to clean various complex medical devices through a pressure pulsating process (i.e., repetitive pump-out and pumpin until the cleaning results meet the cleaning standards for medical devices). The cleaning results of spay washing, ultrasound cleaning and pulsating vacuum cleaning were compared among four groups of medical devices, including silica gel hoses, chamber instruments, whole box of minimally invasive instruments and surgical instruments. The amount of protein residues was tested using the spectrophotometric method. The testing results revealed that the loading capacity of a pulsating vacuum cleaning machine is 3–4 times as much as that of an ordinary spray cleaning machine, without manual placement and connection operation required, which reduced the workload of pretreatment. The protein residue after cleaning meets the requirements of the YY/T0734 standard for the cleaning effect of medical devices. Pulsating vacuum cleaning technology has an overall better loading capacity, when compared to spay washing and ultrasound cleaning, and this can make up for the shortcomings of commonly used cleaning machines, such as the low cleaning efficiency and unsatisfactory cleaning results of medical devices with complex structures.

A method for determining stoichiometric coefficients using minors of a matrix

Spinel materials often have complex structures and as a result, balancing of reactions with these compounds by traditional methods become very time consuming. A method to calculate the stoichiometric coefficients for chemical reactions using first a modified matrix-inverse method and then an optimised method is proposed. Both methods are explored using linear algebra and the result demonstrated using a typical chromite reduction reaction.

A METHOD FOR DETERMINING STOICHIOMETRIC COEFFICIENTS USING MINORS OF A MATRIX

Spinel materials often have complex structures and as a result, balancing of reactions with these compounds by traditional methods become very time consuming. A method to calculate the stoichiometric coefficients for chemical reactions using first a modified matrix-inverse method and then an optimised method is proposed. Both methods are explored using linear algebra and the result demonstrated using a typical chromite reduction reaction.

Quo Vadis Nonlinear Optics? An Alternative and Simple Approach to Third Rank Tensors in Semiconductors

It is well understood that nonlinear optical (NLO) phenomena are deeply related to the material’s symmetry. Mathematically, the material symmetry can be described in terms of the nonzero parameters in the nonlinear susceptibility tensors. Generally, more complex structures involve more nonzero parameters in the tensor. The number of parameters increases rapidly if higher NLO orders are considered, complicating the physical analysis. Conventionally, these parameters are obtained via abstract symmetry analysis, e.g., group theory (GT). This work presents a novel theoretical analysis to approach the nonlinear tensor using the simplified bond hyperpolarizability model (SBHM) and compare it with GT. Our analysis is based on a light–matter interaction classical phenomenological physical framework. Rather than just looking at the symmetry of the crystal, the model applies physical considerations requiring fewer independent parameters in the tensor than GT. Such a simplification significantly improves the determination of the surface–bulk SHG contribution factors, which cannot be extracted from the experiment alone. We also show for the case of perovskite that the SHG contribution can be addressed solely from their surface dipoles with only one independent component in the tensor. Therefore, this work may open the path for a similar analysis in other complicated semiconductor surfaces and structures in the future, with potential applications to nanoscale surface characterization and real-time surface deposition monitoring.

Selective skeletal editing of polycyclic arenes using organophotoredox dearomative functionalization

Reactions that lead to destruction of aromatic ring systems often require harsh conditions and, thus, take place with poor selectivities. Selective partial dearomatization of fused arenes is even more challenging but it can be a strategic approach to creating versatile, complex polycyclic frameworks. Herein we describe a general organophotoredox approach for the chemo- and regioselective dearomatization of structurally diverse polycyclic aromatics, including quinolines, isoquinolines, quinoxalines, naphthalenes, anthracenes and phenanthrenes. The success of the new method for chemoselective oxidative rupture of aromatic moieties relies on precise manipulation of the electronic nature of the fused polycyclic arenes. Experimental and computational results show that the key to overcoming the intrinsic thermodynamic and kinetic unfavorability of the dearomatization process is an ultimate hydrogen atom transfer (HAT) step, which enables dearomatization to predominate over the otherwise favorable aromatization pathway. We show that this strategy can be applied to rapid synthesis of biologically valued targets and late-stage skeletal remodeling en route to complex structures.

A new method for determining stoichiometric coefficients using minors of a matrix

Spinel materials often have complex structures and as a result, balancing of reactions with these compounds by traditional methods become very time consuming. A method to calculate the stoichiometric coefficients for chemical reactions using first a modified matrix-inverse method and then an optimised method is proposed. Both methods are explored using linear algebra and the result demonstrated using a typical chromite reduction reaction.

11 Electrophotocatalysis

Electrocatalysis and photocatalysis have proven to be powerful strategies for molecular synthesis. Recently, methods that combine the power of light and electricity within a single catalyst have been reported. This area, termed electrophotocatalysis, offers new opportunities to promote challenging transformations. This chapter covers recent work in this area and demonstrates some of the possibilities offered by these approaches for rapidly constructing complex structures through the merger of electrochemical and photochemical energy.