High-coverage characterization and discovery of molecular markers for quality control of natural fragrant plant extracts using UPLC-HRMS-based untargeted metabolomics.

The chemical components of natural fragrant plant extracts are of high complexity, and the strategies for quality control (QC) and further discovery of fragrance mechanisms still need to be further investigated. This study integrated the strategies and methods of untargeted metabolomics and chemometrics and statistical modeling to attain the goal. The techniques of reversed-phase and HILIC analysis of ultra-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS) were simultaneously used to collect data in both positive and negative ion modes.

Study on the correlation and difference of qualitative information among three types of UPLC-HRMS and potential generalization in metabolites annotation.

The variation of qualitative information among different types of mainstream hyphenated instruments of ultra-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC-HRMS) makes data sharing and standardization, and further comparison of results consistency in metabolite annotation not easy to attain. In this work, a quantitative study of correlation and difference was first achieved to systematically investigate the variation of retention time (t), precursor ion (MS), and product fragment ions (MS) generated by three typical UPLC-HRMS instruments commonly used in metabolomics area. In terms of the findings of systematic and correlated variation of t, MS, and MS between different instruments, a computational strategy for integrated metabolite annotation was proposed to reduce the influence of differential ions, which made full use of the characteristic (common) and non-common fragments for scoring assessment.

Method comparison of sample pretreatment and discovery of differential compositions of natural flavors and fragrances for quality analysis by using chemometric tools.

Natural flavors and fragrances or their extracts have been widely used in a large variety of areas, including food, cosmetic, and tobacco industrial processes, among others. The compositions and intrinsic attributes of flavors and fragrances were related to many factors, such as species, geographical origin, planting environment, storage condition, processing method, and so on. This not only increased the difficulty in analyzing the product quality of flavors and fragrances, but also challenged the idea of "quality-by-design (QbD)".

[Histopathological study on the healing of orthodontic implant-bone interface adjacent to extraction].

Objective: Osseointegration of orthodontic microscrew implant is influenced by tooth extraction. This study aims to evaluate the safety margin of the osseointegration of orthodontic implants by investigating the healing process of the implant-bone interface through histopathological studies and quantitative determination.

Methods: Twelve male beagles were selected and randomly divided into four groups.

Bone remodeling at microscrew interface near extraction site in the beagle dog mandible-histologic and immunohistochemical analyses.

Unlabelled: Extraction is often used as part of orthodontic therapy, and good control of anchorage is a key step after extraction. Although microscrews can be implanted close to the extraction site in order to achieve orthodontic support, the efficiency of bone remodeling at the implant-bone interface near the extraction region is dubious.

Objective: The purpose of this study was to investigate bone remodeling of the bone-microscrew interface near the tooth extraction site, in the absence of loading.

Synthesis and biodistribution of a new (99m) Tc-oxo complex with deoxyglucose dithiocarbamate for tumor imaging.

The deoxyglucose dithiocarbamate (DGDTC) was radiolabeled with (99m) Tc(V)-glucoheptonate (GH), for the potential use as radiopharmaceuticals for tumor imaging. For labeling, (99m) TcO-DGDTC was prepared by ligand-exchange reaction with (99m) Tc-GH. The radiochemical purity of the (99m) TcO-DGDTC complex was over 90% by thin-layer chromatography and high-performance liquid chromatography, without any notable decomposition at room temperature over a period of 6 h.