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)". This work proposed an integrated strategy for precise discovery of differential compounds among different classes and subsequent quality analysis of complex samples through flavors and fragrances used in tobacco industry as examples. Three pretreatment methods were first inspected to effectively characterize the sample compositions, including direct injection (DI), thermal desorption (TD), and stir bar sorptive extraction (SBSE)-TD, coupled with gas chromatography-mass spectrometry (GC-MS) analysis to obtain characteristic information of samples of flavors and fragrances. Then, principal component analysis (PCA) was applied to discover the relation and difference between chromatographic fingerprints and peak table data once significant components were recognized in a holistic manner. Model population analysis (MPA) was then used to quantitatively extract the characteristic chemicals representing the quality differences among different classes of samples. Some differential marker compounds were discovered for difference analysis, including benzyl alcohol, latin acid, l-menthol acid, decanoic acid ethyl ester, vanillin, trans-o-coumaric acid, benzyl benzoate, and so on. Furthermore, partial least squares-discriminant analysis (PLS-DA) and support vector machine (SVM) were respectively applied to construct multivariate models for evaluation of quality differences and variations. It was found that the accuracy attains to 100% for sample classification. With the help of optimal sample pretreatment technique and chemometric methods, the strategy for quality analysis and difference discovery proposed in this work can be widely delivered to more areas of complex plants with good interpretability and high accuracy.

[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. An orthodontic microscrew was implanted beside the tooth extraction area. Animals were killed in 1, 3, 8, and, 12 weeks to investigate tissue response. Histomorphological observation and bone implant contact ratio (BIC) tests were performed at different healing time after implantation. RESULTS: A new bone was formed on the implant-bone interface of the control group. Bone resorptions were also detected in the experimental group 3 weeks after implantation. The BIC level of the control groups increased during the first 8 weeks; no change was observed anymore after the 8th week. On the other hand, the BIC value in the experimental group decreased in the first 3 weeks. It then increased rapidly and reached its peak of 80.08% in the 8th week. No significant difference wa s found between the experimental and control groups in the first 3 weeks. After the 3rd week, the BIC value of the experimental group (44.35%) was lower than that of the control group (55.46%) (P < 0.01). CONCLUSION: The healing process after implantation was influenced by tooth extraction. Bone resorption was detected at an early stage. However, vigorous bone remodeling was observed subsequently.

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. MATERIAL AND METHODS: Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses. RESULTS: Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-ß) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (P<0.05). Subsequently, the expression levels of Cbfa1, OC and TGF-ß were found to increase significantly, and active osteogenesis was observed. CONCLUSIONS: During week 1, inflammatory reaction is a major concern at the bone-microscrew interface near the extraction site. However, with healing, the influence of extraction on the remodeling of bone surrounding the microscrews decreases, thus facilitating successful treatment.

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

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. MATERIAL AND METHODS: Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses. RESULTS: Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-β) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (P<0.05). Subsequently, the expression levels of Cbfa1, OC and TGF-β were found to increase significantly, and active osteogenesis was observed. CONCLUSIONS: During week 1, inflammatory reaction is a major concern at the bone-microscrew interface near the extraction site. However, with healing, the influence of extraction on the remodeling of bone surrounding the microscrews decreases, thus facilitating successful treatment. .

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. Its partition coefficient indicated that it was a hydrophilic complex. The ligand-exchange reaction occured at neutral condition and under 100 °C for 15 min to achieve high radiochemical purity. In vitro cell studies showed there was an increase in the uptake of (99m) TcO-DGDTC as a function of incubation time and the cellular uptake of (99m) TcO-DGDTC was possibly mediated by way of a d-glucose mechanism. The biodistribution of (99m) TcO-DGDTC in mice bearing S 180 tumor showed that the complex accumulated in the tumor with good uptake and excellent retention. As compared with other reported (99m) Tc radiolabeled glucose derivatives, (99m) TcO-DGDTC showed the highest tumor uptake and good tumor/muscle ratios. The tumor/muscle ratio of (99m) TcO-DGDTC uptake was higher than that of [(18) F] FDG uptake. Single photon emission computed tomography (SPECT) image studies showed there was a visible accumulation in tumor sites, suggesting (99m) TcO-DGDTC would be a promising candidate for tumor imaging.