Experiment and Computational Study on Pd-Catalyzed Methoxyiminoacyl-Directed γ-Alkoxylation of Alkylamides.

The direct alkoxylation of amides has been accomplished via methoxyiminoacyl (MIA)-mediated Pd-catalyzed C-H functionalization. A diverse array of alkylamide substrates is amenable to this protocol, providing γ-C(sp3)-alkoxylation of alkylamide derivatives with good to high efficiency. Two aspects of the research were completed to explore the reaction mechanism. On the one hand, the result of the kinetic isotopic effect experiment and control experiment indicated that reductive elimination is a rate-limiting step. On the other hand, density functional theory calculations demonstrated that a concerted Sn2 reductive elimination mechanism pathway is prior. Finally, the MIA group could be efficiently hydrogenated and protected in a one-pot procedure, which provides a short synthetic route to γ-methoxy amino acid derivatives.

Effects of three medical nutrition therapies on nutritional metabolism and intestinal flora in overweight/obese with polycystic ovary syndrome (PCOS): Study protocol for a randomised controlled trial.

BACKGROUND AND OBJECTIVES: Observational studies have shown that energy restriction could be beneficial for controlling bodyweight in patients with polycystic ovary syndrome (PCOS). We aim to compare the effects of a high-protein diet (HPD), a high-protein and high-dietary fiber diet (HPHFD), and a calorie-restricted diet (CRD) on metabolic health and gut microbiota in overweight/obese PCOS patients. METHODS AND STUDY DESIGN: We will enroll a total of 90 overweight/obese PCOS patients into this eight-week open-label randomised controlled trial. Participants will be randomly assigned to three groups: CRD group (energy coefficient 20 kcal/kg.day, water ≥1500 mL, 0.8-1.2 g/kg protein, carbohydrate energize 55-60%, and fat energize 25-30%), HDP group (energy coefficient 20 kcal/kg.day, water ≥1500 mL, and 1.5-2.0 g/kg protein) and HPHFD group (based on the high protein diet with 15 g more dietary fiber supplement). The primary outcome is body weight, body fat percentage, and lean body mass. The secondary outcomes will include changes in blood lipids, inflammation, glucose tolerance, blood pressure, and gut microbiota compositions. Between-group differences in adiposity measurements at baseline will be compared using one-way analysis of variance (ANOVA) or Kruskal-Wallis test when appropriate. Within-group difference after 8-week intervention will be compared using paired t-test or Wilcoxon signed rank test. Between-group differences in adiposity measurements after 8-week diet intervention will be compared using linear mixed model and ANCOVA. The gut microbiota will be analyzed using 16S amplicon sequencing and the sequencing data will be analyzed using the standardized QIIME2 piperline.

Application of robotics in stomatology.

The application of robots in oral treatment can not only reduce the work intensity of clinicians but also improve the accuracy of treatment. In this article, the application and research status of robots in stomatology are reviewed.

Complementary feeding and childhood adiposity in preschool-aged children in a large Chinese cohort.

OBJECTIVE: To examine the association between the timing and type of complementary feeding and childhood adiposity in Mainland China. STUDY DESIGN: During 1999-2009, 97 424 singletons were enrolled in the Jiaxing Birth Cohort, a population-based prospective cohort study in Southeast China. Of these children, 43 848 children provided complementary diet information and other anthropometric measurements at 1, 3, and 6 months of age and were followed up until 4-5 years of age. Obesity and overweight were identified as body mass index (BMI)-for-age z-score (SD) ≥2 and between 1 and 2, respectively. RESULTS: Among 40 510 children in the statistical analysis, 3.18% were overweight and 64.8% were fed complementary food before 3 months of age. Early introduction of complementary foods was associated with greater BMI z-score (P-trend < .001) and higher risk of overweight (P-trend = .033). Compared with introduction of complementary foods between 4-6 months of age, before 3 months of age of introduction was associated with 11% greater risk of overweight (OR 1.11, 95% CI 1.03-1.19). No significant association between timing of complementary feeding and obesity was observed. Fish liver oil was the major type of complementary food associated with adiposity. Early introduction of fish liver oil was associated with greater BMI z-score (P < .001) and greater risk of overweight (P-trend = .004). CONCLUSIONS: Early introduction of fish liver oil is associated with greater childhood BMI and risk of overweight in Chinese children at 4-5 years of age.

Qualitative and Quantitative Analysis of Lignan Constituents in Caulis Trachelospermi by HPLC-QTOF-MS and HPLC-UV.

A high-performance liquid chromatography coupled with quadrupole tandem time-of-flight mass (HPLC-QTOF-MS) and ultraviolet spectrometry (HPLC-UV) was established for simultaneous qualitative and quantitative analysis of the major chemical constituents in Caulis Trachelospermi, respectively. The analysis was performed on an Agilent Zorbax Eclipse Plus C18 column (4.6 mm×150 mm, 5 µm) using a binary gradient system of water and methanol, with ultraviolet absorption at 230 nm. Based on high-resolution ESI-MS/MS fragmentation behaviors of the reference standards, the characteristic cleavage patterns of lignano-9, 9'-lactones and lignano-8'-hydroxy-9, 9'-lactones were obtained. The results demonstrated that the characteristic fragmentation patterns are valuable for identifying and differentiating lignano-9,9'-lactones and lignano-8'-hydroxy-9,9'-lactones. As such, a total of 25 compounds in Caulis Trachelospermi were unambiguously or tentatively identified via comparisons with reference standards or literature. In addition, 14 dibenzylbutyrolatone lignans were simultaneously quantified in Caulis Trachelospermi by HPLC-UV method. The method is suitable for the qualitative and quantitative analyses of dibenzylbutyrolatone lignans in Caulis Trachelospermi.

Exclusive breastfeeding is inversely associated with risk of childhood overweight in a large Chinese cohort.

The association between breastfeeding status and childhood overweight is inconclusive. The aim of the present study was to investigate the relation between exclusive breastfeeding and childhood overweight risk in children 4-5 y of age in Southeast China. Among 97,424 children enrolled between 1999 and 2009 in the Jiaxing Birth Cohort, 42,550 of them were included in the final analysis with complete records on breastfeeding status and anthropometric measurements at 4-5 y of age (48-60 mo). Overweight and being at risk of overweight were identified as a body mass index (BMI)-for-age Z-score ≥ 2 and between 1 and 2, respectively. After 4-5 y of follow-up, 4845 (11.4%) children were identified as being at risk of overweight, and 1343 (3.16%) children were overweight. Adjusting for important child and maternal characteristics, longer duration of breastfeeding was associated with lower risk of childhood overweight (P-trend = 0.009) and being at risk of overweight (P-trend < 0.001). Children exclusively breastfed for 3-5 mo and ≥6 mo had 13% (RR = 0.87; 95% CI: 0.77, 0.99) and 27% (RR = 0.73; 95% CI: 0.56, 0.95) lower risk of becoming overweight compared with children exclusively breastfed for <1 mo, respectively. In boys, there were inverse associations of 3-5 mo (RR = 0.83; 95% CI: 0.71, 0.98) or ≥6 mo (RR = 0.65; 95% CI: 0.47, 0.91) of exclusive breastfeeding against becoming overweight, but there were no significant associations in girls (3-5 mo: RR = 0.96, 95% CI: 0.76, 1.22; ≥6 mo: RR = 0.92, 95% CI: 0.60, 1.41). In conclusion, the present findings suggest that longer duration of exclusive breastfeeding is associated with lower risk of becoming overweight in Chinese children.

Active components with inhibitory activities on IFN-γ/STAT1 and IL-6/STAT3 signaling pathways from Caulis Trachelospermi.

Initial investigation for new active herbal extract with inhibiting activity on JAK/STAT signaling pathway revealed that the extract of Caulis Trachelospermi, which was separated by 80% alcohol extraction and subsequent HP-20 macroporous resin column chromatography, was founded to strongly inhibit IFN-γ-induced STAT1-responsive luciferase activity (IFN-γ/STAT1) with IC50 value of 2.43 µg/mL as well as inhibiting IL-6-induced STAT3-responsive luciferase activity (IL-6/STAT3) with IC50 value of 1.38 µg/mL. Subsequent study on its active components led to the isolation and identification of two new dibenzylbutyrolactone lignans named 4-demethyltraxillaside (1) and nortrachelogenin 4-O-ß-D-glucopyranoside (2), together with six known compounds. The lignan compounds 1-4 together with other lignan compounds isolated in previous study were tested the activities on IFN-γ/STAT1 and IL-6/STAT3 pathways. The following result showed that the main components trachelogenin and arctigenin had corresponding activities on IFN-γ/STAT1 pathway with IC50 values of 3.14 µM and 9.46 µM as well as trachelogenin, arctigenin and matairesinol strongly inhibiting IL-6/STAT3 pathway with IC50 values of 3.63 µM, 6.47 µM and 2.92 µM, respectively.

Harmonizing international quality standards for Andrographis paniculata: A comparative analysis of content determination methods across pharmacopeias.

The quality standards for Andrographis paniculata, a widely used medicinal herb, exhibited significant variations across different pharmacopeias. In this study, we compared the HPLC content determination methods and total lactone content of A. paniculata samples from different regions, as specified in the Chinese (CP), United States (USP), European (EP), Thai (TP), and Indian pharmacopeias (IP), as well as the Hong Kong Chinese Materia Medica Standards (HK). We aimed to assess the differences and similarities among these pharmacopeias and harmonized international quality standards for A. paniculata. The analysis revealed variations in sample preparation, liquid chromatographic conditions, fingerprint profiles, and total lactone content among the different pharmacopeias. Specifically, the CP and HK methods exhibited superior sample preparation and chromatographic separation. Further comparing the content of 20 A. paniculata samples with the CP, USP, EP and HK methods showed consistent determinations for the same components, indicating similar detection capabilities. The discrepancies in total lactone content primarily stemmed from differences in the number and types of detected compounds. Moreover, the acceptance criteria exhibited a stringency in the order CP > HK > EP > USP. In conclusion, this comparison analysis of content determination in CP, USP, HK, EP, TP and IP provided a scientific foundation for the international standardization and trade regulations of A. paniculata. It also served as a valuable reference for the development of international quality standards for other medicinal herbs, facilitating the harmonization of global pharmaceutical standards.

[Chemical constituents from the roots of Angelica polymorpha Maxim].

Angelica polymorpha Maxim. is a plant of the Angelica genus (Umbelliferae). The root and stem of this plant is a folk medicine known to have the actions of relieving rheumatism and cold and subsiding swelling and pains. To investigate the chemical constituents in the root of A. polymorpha Maxim., seven compounds were isolated from an 80% ethanol extract by column chromatography. Their structures were elucidated according to the spectroscopic analysis. Compound 1 is a new sesquiterpene, named as bisabolactone. Its absolute configuration was determined by 1D NOESY and CD analysis. The others were identified as 5-hydroxymethylfurfural (2), hycandinic acid ester 1 (3), ferulic acid (4), isooxypeucedanin (5), noreugenin (6) and cimifugin (7). Compound 2 and 3 were isolated from this genus for the first time and compound 4 was isolated from this plant for the first time.

Novel Digital Mouth Preparation Technique for Fabricating Implant-Retained Removable Partial Dentures with Distal Extension: a Case Report.

Implant-retained removable partial dentures (RPDs) are commonly used to resolve the complications associated with traditional distal extension RPDs; however, this technology does not consider the necessity and importance of parallelism between the path of RPD insertion and the long axis of the implant. This clinical report presents a novel digital preparation technique that involves the preparation of parallel guiding planes on abutment teeth and implant insertion in the distal extension area using a computer-aided design and manufacturing template. This clinical case of implant-retained RPDs illustrates the fabrication and application of the digital template. Using this technique, the path of RPD insertion is parallel to the long axis of the implant. As a result, the components of the implant-retained RPD, including the abutment teeth, implants and attachments, can demonstrate greater longevity.

The use of calcium phosphate-based biomaterials in implant dentistry.

Since calcium phosphates (CaPs) were first proposed, a wide variety of formulations have been developed and continuously optimized, some of which (e.g. calcium phosphate cements, CPCs) have been successfully commercialized for clinical applications. These CaP-based biomaterials have been shown to be very attractive bone substitutes and efficient drug delivery vehicles across diverse biomedical applications. In this article, CaP biomaterials, principally CPCs, are addressed as alternatives/complements to autogenous bone for grafting in implant dentistry and as coating materials for enhancing the osteoinductivity of titanium implants, highlighting their performance benefits simultaneously as carriers for growth factors and as scaffolds for cell proliferation, differentiation and penetration. Different strategies for employing CaP biomaterials in dental implantology aim to ultimately reach the same goal, namely to enhance the osseointegration process for dental implants in the context of immediate loading and to augment the formation of surrounding bone to guarantee long-term success.

Characterization of Constituents with Potential Anti-Inflammatory Activity in Chinese Lonicera Species by UHPLC-HRMS Based Metabolite Profiling.

This study centered on detecting potentially anti-inflammatory active constituents in ethanolic extracts of Chinese Lonicera species by taking an UHPLC-HRMS-based metabolite profiling approach. Extracts from eight different Lonicera species were subjected to both UHPLC-HRMS analysis and to pharmacological testing in three different cellular inflammation-related assays. Compounds exhibiting high correlations in orthogonal projections to latent structures discriminant analysis (OPLS-DA) of pharmacological and MS data served as potentially activity-related candidates. Of these candidates, 65 were tentatively or unambiguously annotated. 7-Hydroxy-5,3',4',5'-tetramethoxyflavone and three bioflavonoids, as well as three C32- and one C34-acetylated polyhydroxy fatty acid, were isolated from Lonicera hypoglauca leaves for the first time, and their structures were fully or partially elucidated. Of the potentially active candidate compounds, 15 were subsequently subjected to pharmacological testing. Their activities could be experimentally verified in part, emphasizing the relevance of Lonicera species as a source of anti-inflammatory active constituents. However, some compounds also impaired the cell viability. Overall, the approach was found useful to narrow down the number of potentially bioactive constituents in the complex extracts investigated. In the future, the application of more refined concepts, such as extract prefractionation combined with bio-chemometrics, may help to further enhance the reliability of candidate selection.

Surgical treatment of a giant neurofibroma.

Neurofibromatosis type 1, an autosomal dominant inherited disease, presents pathologic symptoms of multiple systems, including neurofibromatosis, skeletal dysplasia, café-au-lait spots in skins, and so on. A 45-year-old man with neurofibromatosis type 1 was reported in this article. The patient presented a giant neurofibroma in his head and neck, dysplasia of skull, facial bones and spinal columns, and multiple café-au-lait spots in systematic skins. Satisfactory curative effects were obtained in this case after tumor resection and prosthesis implantation.

Allometry and Yield Stability of Cereals.

Crop plants grow, and then, they allocate resources to different structures, including seeds and fruits, which represent yield in most crops. We define the yield stability of a genotype as its ability to reduce the effects of temporal variation in resources and conditions on yield production, and we argue that yield stability can be understood in terms of two processes: (1) crop survival and growth (biomass production): the ability of the crop plants to survive and produce biomass under the range of conditions to which it is exposed and (2) the pattern of allocation of this biomass to yield across this range of conditions. Plant breeders and crop physiologists have focused on (1), but much less attention has been paid to (2). We hypothesize that (2) is primarily the result of reproductive allometry: the quantitative relationship between vegetative and reproductive biomass. Ecological theory and the allometric models we present predict a tradeoff between (a) the ability of a genotype to produce yield over a wide variety of conditions and (b) its ability to produce very high yields under optimal or near-optimal conditions. We reanalyze the data from two recent studies, and the results are consistent with this hypothesis. Yield stability in crops corresponds to bet-hedging in evolutionary ecological theory. It is the most appropriate strategy for smallholder farmers in developing countries, a group that comprises most of the farmers in the world. Researchers and crop breeders need to rethink their objectives if they want to develop optimal varieties for these farmers.

[A new naphthaquinone derivative from Pyrola calliantha H. Andres].

To investigate the chemical constituents of hemostatic extract of Pyrola calliantha H. Andres, the extract was subjected to chromatographic separation and purification. Along with some known compounds, a new naphthaquinone derivative was isolated and identified as 2-(1, 4-dihydro-2, 6-dimethyl-1, 4-dioxo-3-naphthalenyl)-3, 4, 5-trihydroxylbenzoic acid by physicochemical and spectroscopic analysis.

Distribution Dynamics and Roles of Starch in Non-photosynthetic Vegetative Organs of Santalum album Linn., a Hemiparasitic Tree.

Allocation dynamics of stored starch plays essential roles in the development and growth of trees. Previous studies focused on the dynamics and the characteristics of starch in autotrophic trees. However, although starch granules have been detected in the organs or tissues of some parasitic plants, studies on the allocation dynamics and roles of storage starch in them are limited. Therefore, we determined and estimated the allocation dynamics and roles of starch in Santalum album Linn., a hemiparasitic tree, using morphological and physiological methods. Our findings showed abundant starch in the stem and root of S. album at the early seedling stage. Although S. album seedlings attached to the host showed no significant changes in starch levels throughout the experiment, unattached and host-removed seedlings exhibited a gradual decrease in the starch content over time. When the starch content of unattached seedlings was less than 1%, they started to die. Starch accumulated to high levels in developing and active haustoria; however, starch levels were low in the inactive haustoria. The present study suggests that starch may provide energy to seedlings that have no host, allowing them to survive during the unattached phase, thus increasing their chance to attach to host roots by extending their survival duration. In addition, we speculate that storage starch is potentially involved in the development of haustoria and in the physiological processes of S. album related to the absorption and transportation of water and nutrients from its host.

The association between roofing material and head injuries during the 2008 Wenchuan earthquake in China.

STUDY OBJECTIVE: We analyze the spectrum of earthquake-related head injuries resulting in hospitalization and arising from the 2008 Wenchuan Earthquake in China. An additional objective is to assess injury patterns associated with 2 types of roofing structures found in this region of China. METHODS: This descriptive study included data on trauma patients at 8 hospitals in Jiangyou for the 14 days immediately after the earthquake. The patients were either from Jiangyou County, which experienced a modified Mercalli intensity level of VIII, or from Beichuan County (Mercalli intensity level of X). Of the 5,775 earthquake-related injuries, 1,484 (25.7%) involved the head and were classified into 4 categories. Seven injury mechanisms were also analyzed to determine the association with the 4 types of head injuries. RESULTS: Scalp injuries (43%) were the most common type of head injuries, followed by facial injuries, 482 (32%), intracranial injuries, 218 (15%), and skull fractures, 117 (8%). Differences in injury type and cause were apparent, with scalp injuries being more common (49%) in Jiangyou than in Beichuan (30%) and falling clay tiles contributing more (40%) to this injury in the former city than the latter (6%). In contrast, precast concrete plank roofing caused 20% of scalp injuries in Beichuan compared with 3% in Jiangyou. CONCLUSION: Scalp injuries were the most common head injury type. Falling clay roofing tiles and precast concrete plank roofs are important injury mechanisms, and their contribution may reflect differences in building construction.

[Determination of icaritin in rat plasma by HPLC-MS/MS].

The paper is to report the development of a high-performance liquid chromatographic/tandem mass spectrometry (HPLC-MS/MS) method for the determination of icaritin (ICT) in rat plasma. After precipitated with acetonitrile from the plasma, ICT was isolated chromatographically on a Dikma C18 column. The mobile phase consisted of acetonitrile-water-acetic acid (72 : 28 : 1.5, v/v/v). Electrospray ionization (ESI) source was applied and operated in the positive ion mode. Multiple reaction monitoring (MRM) mode with the transitions of m/z 387 --> m/z 313 and m/z 331 --> m/z 315 were used to quantify ICT and the internal standard, respectively. The linear calibration curve was obtained in the concentration range of 2.5-1,000 ng x mL(-1). The lower limit of quantification was 2.5 ng x mL(-1). The inter- and intra-day precision (RSD) were less than 9.63%, and the accuracy (relative error) was within +/-7.42%. The method was proved to be suitable for the pharmacokinetics of ICT, which offers advantages of high sensitivity and selectivity.

[FTIR spectroscopic studies of facial prosthetic adhesives].

According to the composition of the traditional facial prosthetic adhesives, most of adhesives can be classified into two categories: acrylic polymer-based adhesive and silicone-based adhesive. In previous studies, measurements of various mechanical bond strengths were carried out, whereas the functional groups of the adhesives were evaluated seldom during the adhesion. In the present study the analysis of two facial prosthetic adhesives (Epithane and Secure Adhesive) was carried out by using infrared spectroscopy. Two adhesives in the form of fluid or semisolid were submitted to FTIR spectroscopy, respectively. The results showed that water and ammonia residue volatilized during the solidification of Epithane, and absorption peak reduction of carbonyl was due to the volatilization of acetate vinyl from Secure Adhesive. Similar silicone functional groups both in the silicone-based adhesive and in silicone elastomer could be the key to higher bond strength between silicone elastomer and skin with silicone-based adhesive. The position, shape of main absorption peaks of three adhesives didn't change, which showing that their main chemicals and basic structures didn't change during solidification.

Novel glycidyl methacrylated dextran (Dex-GMA)/gelatin hydrogel scaffolds containing microspheres loaded with bone morphogenetic proteins: formulation and characteristics.

Novel thermomechanical hydrogel scaffolds containing our previously prepared microspheres loaded with bone morphogenetic proteins (BMP) were successfully generated by radical crosslinking and low dose gamma-irradiation from combination of two kind of biomaterials: glycidyl methacrylated dextran (Dex-GMA) and gelatin. The structure of those resulting smart hybrid hydrogels was evaluated by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) analyses, and as a function of the degree of Dex-GMA's substitution (DS), the proportion between Dex-GMA and gelatin, and the initial polyethyleneglycol (PEG) concentration used in the preparation of the hydrogels. The swelling and degradation properties and the temperature-sensitive drug release manner were determined by dynamic evaluation methods in vitro, and the gel content was also calculated. MIP analysis showed that by systematically altering the preparation parameters, the overall networks were clearly macroporous with pore sizes ranging from 5.6+/-4.2 to 37.7+/-13.7 microm. As expected, the pore size decreased as DS and initial PEG concentration increased, whereas the opposite was found for the gel content. Moreover, the porosity values ranged from 73.7+/-12.4% up to 89.6+/-6.3%. The SEM results also showed the inter-connective pores as well as microspheres encased into their porous structure of those hydrogels. The swelling and degradation properties of the resultant hydrogels varied according to the DS of Dex-GMA and initial PEG concentration, while the proportion between Dex-GMA and gelatin had no significant influence on those characterizations. By changing the composition ratio of the two precursors, the phase transition temperature (lower critical solution temperature, LSCT) of the hydrogel scaffolds could also be adjusted to be or near the body temperature, so BMP release from microsphere-hydrogel compounds could be accordingly controlled and the release period could be varied from 18 to more than 28 days. These results demonstrated that a novel temperature-sensitive and biodegradable Dex-GMA/gelatin scaffold containing microspheres loaded with BMP could be successfully developed from both dextran- and gelatin-based biomaterials, which could promisingly satisfy the need, desire, and expectation of both self-regulated drug delivery and tissue-engineering applications.