Current Views of the Structure of the Mammalian Mitochondrial Ribosome

Mammalian mitochondria synthesize polypeptides crucial for energy generation using ribosomes with a number of unique features. These ribosomes are very protein rich and have very truncated ribosomal RNAs. The bulk of the mammalian mitochondrial ribosome is composed of proteins, only about half of which are homologs of ribosomal proteins found in other translational systems. A number of distinctive features are found in these ribosomes. Among these is a gate-like structure that allows entrance of the primarily leaderless mRNAs that characterize this system. The exit tunnel of the large subunit is also quite unusual and includes a site in which the nascent peptide is visible to solvent prior to the normal exit site. Further, this region of the mitochondrial ribosome is dominated by ribosomal proteins rather than rRNA and is involved in the interaction of the ribosome with the inner membrane where all of the translation products are ultimately located. The proteins of the mitochondrial ribosome appear to play a number of important roles in the cell in addition to their function in protein biosynthesis, including roles in apoptosis and in cell cycle control.     

Molecular Genetics of Conjunctival Melanoma and Prognostic Value of TERT Promoter Mutation Analysis

The aim of this study was exploration of the genetic background of conjunctival melanoma (CM) and correlation with recurrent and metastatic disease. Twenty-eight CM from the Rotterdam Ocular Melanoma Study group were collected and DNA was isolated from the formalin-fixed paraffin embedded tissue. Targeted next-generation sequencing was performed using a panel covering GNAQ, GNA11, EIF1AX, BAP1, BRAF, NRAS, c-KIT, PTEN, SF3B1, and TERT genes. Recurrences and metastasis were present in eight (29%) and nine (32%) CM cases, respectively. TERT promoter mutations were most common (54%), but BRAF (46%), NRAS (21%), BAP1 (18%), PTEN (14%), c-KIT (7%), and SF3B1 (4%) mutations were also observed. No mutations in GNAQ, GNA11, and EIF1AX were found. None of the mutations was significantly associated with recurrent disease. Presence of a TERT promoter mutation was associated with metastatic disease (p-value = 0.008). Based on our molecular findings, CM comprises a separate entity within melanoma, although there are overlapping molecular features with uveal melanoma, such as the presence of BAP1 and SF3B1 mutations. This warrants careful interpretation of molecular data, in the light of clinical findings. About three quarter of CM contain drug-targetable mutations, and TERT promoter mutations are correlated to metastatic disease in CM.     

Electrochemical and spectroscopic characterization of a Benzo[c]cinnoline electrografted platinum surface

In this work, a platinum surface was modified with benzo[c]cinnoline (BCC) to get new insight into the metal modification area. By potential scanning from + 0.4 V to - 0.8 V, the diazotized BCC was reduced electrochemically and grafted onto the platinum electrode surface to form benzo[c]cinnoline modified platinum electrode (Pt-BCC). Electrochemical reduction of benzo[c]cinnoline diazonium salt on the electrode surface yielded a relatively stable organic film. The introduction of BCC molecules onto the platinum surface was verified by cyclic voltammetry, electrochemical impedance spectroscopy, Raman spectroscopy and ellipsometry. The stability and the potential range of the Pt-BCC electrode were also studied.     

An intelligent system for multivariate statistical process monitoring and diagnosis

A knowledge-based system (KBS) was designed for automated system identification, process monitoring, and diagnosis of sensor faults. The real-time KBS consists of a supervisory system using G2 KBS development software linked with external statistical modules for system identification and sensor fault diagnosis. The various statistical techniques were prototyped in MATLAB, converted to ANSI C code, and linked with the G2 Standard Interface. The KBS automatically performs all operations of data collection, identification, monitoring, and sensor fault diagnosis with little or no input from the user. Navigation throughout the KBS is via menu buttons on each user-accessible screen. Selected process variables are displayed on charts showing the history of the variables over a period of time. Multivariate statistical tests and contribution plots are also shown graphically. The KBS was evaluated using simulation studies with a polymerization reactor through a nonlinear dynamic model. Both normal operation conditions as well as conditions of process disturbances were observed to evaluate the KBS performance. Specific user-defined disturbances were added to the simulation, and the KBS correctly diagnosed both process and sensor faults when present.     

Dyeing of poly(lactic acid) fibres with synthesised novel heterocyclic disazo disperse dyes

Poly(lactic acid) (PLA) is the first melt‐processable, renewable, sustainable and biodegradable natural‐based synthetic fibre. It has a broad range of uses and combines ecological advantages with outstanding performance in textiles. PLA fibre, as an aliphatic polyester, can be dyed with disperse dyes. Apart from the limited number of commercial disperse dyes, disperse dye exhaustion on PLA is generally lower than that on  poly(ethylene terephthalate) (PET). In this study, new heterocyclic disazo disperse dyes, substituted with methyl, nitro and chloro groups at their ortho‐, meta‐ and para‐ positions, synthesised in our previous study, were applied to PLA and PET fibres to examine their dyeing performance, and colour fastness and dye exhaustion properties. Different shades of yellow, orange, reddish brown and brown were obtained. Most of the synthesised novel heterocyclic disazo disperse dyes exhibited good build‐up properties with high K/S levels on both fibres. Para‐ bonding substituent provided higher K/S values than meta‐ and ortho‐ positions for –NO₂ and –Cl substituents for both fibres. Overall, the most synthesised novel heterocyclic disazo disperse dyes in this study exhibited good build‐up properties with high K/S, exhaustion and wet fastness levels on both PLA and PET fibres.      

Capturing Preservice Chemistry Teachers’ Visual Representations of Redox Reactions through Storyboards

This study aimed to identify preservice chemistry teachers’ understanding of redox reactions at the submicroscopic level and how they make connections to macroscopic level. Twenty‐five preservice chemistry teachers first viewed a video of a redox reaction happening between a zinc wire and a copper(II) sulfate solution, then they reflected on their macroscopic observations, and generated storyboards (a sequence of drawings) representing this reaction at the submicroscopic level. Both the reflections and the storyboards were coded, and the categories reflecting the participants’ levels of understanding were determined. Results showed that the participants usually identified the macroscopic evidences, but they had conceptual difficulties in interpreting and representing evidences at the submicroscopic level. Few participants indicated a scientific or a moderate understanding of redox reactions, whereas the majority exhibited either weak or alternative understanding of redox reactions.     

Integration of simulation modeling and computer aided production management in computer integrated enterprise

Designing efficient and integrated manufacturing systems is the first step in attaining computer integrated enterprises (CIE). Integration of planning and implementation phases of manufacturing is essential for taking full advantage of the CIE. In order to design reliable and efficient manufacturing systems, the designers must consider the impacts of planning decisions made by computer aided production management (CAPM) modules on implementations held in manufacturing cells.

This paper focuses on two issues. The first issue is importance and necessity of integrating CAPM modules with manufacturing cells. The second issue includes major features of the object-oriented approach and their relevance to our objective of modeling a design framework which focuses on integration of CAPM modules and simulation models which emulate the manufacturing cells in the CIE environment.     

浅谈面向对象分析的基础教学

针对一个业务应用实例进行介绍,从而引入软件工程、面向对象分析的基本概念、优点和表示方法,并向读者展现如何在程序设计课程中开展面向对象分析与设计的基础教学。