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1.
Front Neurol ; 15: 1423956, 2024.
Article in English | MEDLINE | ID: mdl-38988601

ABSTRACT

Purpose: How cortical functional reorganization occurs after hearing loss in preschool children with congenital sensorineural hearing loss (CSNHL) is poorly understood. Therefore, we used resting-state functional MRI (rs-fMRI) to explore the characteristics of cortical reorganization in these patents. Methods: Sixty-three preschool children with CSNHL and 32 healthy controls (HCs) were recruited, and the Categories of Auditory Performance (CAP) scores were determined at the 6-month follow-up after cochlear implantation (CI). First, rs-fMRI data were preprocessed, and amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were calculated. Second, whole-brain functional connectivity (FC) analysis was performed using bilateral primary auditory cortex as seed points. Finally, Spearman correlation analysis was performed between the differential ALFF, ReHo and FC values and the CAP score. Results: ALFF analysis showed that preschool children with CSNHL had lower ALFF values in the bilateral prefrontal cortex and superior temporal gyrus than HCs, but higher ALFF values in the bilateral thalamus and calcarine gyrus. And correlation analysis showed that some abnormal brain regions were weak negatively correlated with CAP score (p < 0.05). The ReHo values in the bilateral superior temporal gyrus, part of the prefrontal cortex and left insular gyrus were lower, whereas ReHo values in the bilateral thalamus, right caudate nucleus and right precentral gyrus were higher, in children with CSNHL than HCs. However, there was no correlation between ReHo values and the CAP scores (p < 0.05). Using primary auditory cortex (PAC) as seed-based FC further analysis revealed enhanced FC in the visual cortex, proprioceptive cortex and motor cortex. And there were weak negative correlations between the FC values in the bilateral superior temporal gyrus, occipital lobe, left postcentral gyrus and right thalamus were weakly negatively correlated and the CAP score (p < 0.05). Conclusion: After auditory deprivation in preschool children with CSNHL, the local functions of auditory cortex, visual cortex, prefrontal cortex and somatic motor cortex are changed, and the prefrontal cortex plays a regulatory role in this process. There is functional reorganization or compensation between children's hearing and these areas, which may not be conducive to auditory language recovery after CI in deaf children.

2.
Sch Psychol ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38934898

ABSTRACT

The increase in social media mental health (MH) campaigns provides an opportunity to improve awareness and attitudes toward MH. However, racial disparities remain in these social media campaigns. Black youth who participated in MH social media campaigns reported lower levels of improvement in stigma and help-seeking than their White peers. We employed a youth participatory action research (YPAR) process to expand on a previous community-wide MH social media campaign (A. Thompson et al., 2021), focusing on a Central Midwest community. We studied Black adolescents' perceptions of MH stigma and help-seeking to determine essential features of a culturally responsive MH social media campaign for Black youth. With a lead youth-research collaborator, the research team designed the following two-staged study. The first stage consisted of four semistructured focus group interviews (FGIs) (N = 20), analyzed by using a rapid analysis strategy to obtain results for the development of the campaign. In the second stage, using YPAR's iterative and action-based process, five youth researchers collaborated with the research team on the campaign's design. Following the two stages, the researcher's thematic analysis resulted in three themes: (a) broadening horizons for campaign designers and MH professionals; (b) considering mistrust of schools and school personnel; and (c) diverse experiences, sustainability, and accessibility in a campaign. Findings indicated that while culturally responsive social media campaigns to promote MH can be designed, mistrust of adults in schools is likely to hinder the impact of such campaigns. Implications for school psychology practice and research are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

3.
Neuroscience ; 551: 254-261, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-38848776

ABSTRACT

N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) are brain metabolites involved in some key neuronal functions within the brain, such as cognitive function. The aim of this study was to investigate whether Parkinson's disease (PD) with different cognitive status induces regional brain metabolite differences. 38 diagnosed PD patients, including 18 PD patients with normal cognitive (PDN), 20 PD subjects with cognitive impairment (PDMCI) and 25 healthy controls (HC) participated in this study. All subjects underwent a single-voxel proton MR spectroscopy (1H-MRS) on a 3T scanner. 1H-MRS were obtained from bilateral PCC, left thalamus and PFC regions in all subjects, respectively. Region-specific cerebral metabolic alterations existed in PD patients with different cognitive status. PDMCI patients showed a significant reduction of NAA, Cho and tCr in the PCC and left thalamus, compared to healthy controls; whereas lower levels of NAA and Cho in thalamus were found in PDN patients. Moreover, Cho and tCr levels were positively correlated with MMSE scores. Both NAA and tCr in PCC levels were positively correlated with MMSE and MoCA scores. The combination of thalamic and PCC metabolites showed a 75.6% accuracy in distinguishing PDMCI patients from PDN patients. This study provides preliminary evidence that thalamic, PCC and PFC neurometabolic alterations occur in PD patients with cognition decline. Findings of this study indicate that NAA and tCr abnormalities in PCC and thalamus might be used as a biomarker to track cognitive decline in Parkinson's disease in clinical settings.


Subject(s)
Aspartic Acid , Choline , Cognitive Dysfunction , Creatine , Parkinson Disease , Humans , Parkinson Disease/metabolism , Parkinson Disease/diagnostic imaging , Male , Female , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/diagnostic imaging , Creatine/metabolism , Choline/metabolism , Middle Aged , Aged , Aspartic Acid/analogs & derivatives , Aspartic Acid/metabolism , Proton Magnetic Resonance Spectroscopy , Thalamus/metabolism , Thalamus/diagnostic imaging , Brain/metabolism , Brain/diagnostic imaging , Neuropsychological Tests
4.
Angew Chem Int Ed Engl ; : e202401782, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38818649

ABSTRACT

gem-Diborylalkanes are highly valuable building blocks in organic synthesis and pharmaceutical chemistry due to their ability to participate in multi-step cross-coupling transformations, allowing for the rapid generation of molecular complexity. While progress has been made in their synthetic metholodology, the construction of ß-tertiary and C(sp3)-rich gem-diborylalkanes remains a synthetic challenge due to substrate limitations and steric hindrance issues. An approach is presented that utilizes synergistic photoredox and copper catalysis to achieve efficient C(sp3)-C(sp3) cross-coupling of alkyl N-hydroxyphthalimide esters, which can easily be obtained from alkyl carboxylic acids, with diborylmethyl species, providing a series of C(sp3)-rich gem-diborylalkanes with 1°, 2°, and even 3° ß positions. Furthermore, this approach can also be applied to complex medicinal compounds and natural products, offering rapid access to molecular complexity and late-stage functionalization of C(sp3)-rich drug candidates. Mechanistic experiments revealed that diborylmethyl Cu(I) species participated in both the photoredox process and the key C(sp3)-C(sp3) bond-forming step.

5.
Int J Biol Macromol ; 251: 126411, 2023 Aug 19.
Article in English | MEDLINE | ID: mdl-37598819

ABSTRACT

Our previous study found that 1-octen-3-ol fumigation treatment could effectively induce the resistance of peach fruit diseases. However, 1-octen-3-ol is a liquid fumigant, which is not conducive to storage and application. Herein, the gel of 1 % agar compound with 1 % curdlan was used as a novel material for covering 1-octen-3-ol. The interaction of agar and curdlan was promoted by adding 1-octen-3-ol, leading to a higher thermostability compared to single-component antibacterial gels. Moreover, 1-octen-3-ol resulted in changes in the internal structure and mechanical properties of gel to form a pore-like structure, which is beneficial to the retention and release of 1-octen-3-ol. Additionally, the 2 % agar gel containing 1-octen-3-ol had the best inhibitory effect on the mycelial growth of Monilinia fructicola and Rhizopus stolonifer in vitro, and the compound hydrogel of 1 % agar and 1 % curdlan with 1-octen-3-ol could most effectively inhibit brown rot and soft rot caused by these two pathogens in vivo. Overall, the data indicated that the novel 1-octen-3-ol-loaded agar/curdlan hydrogels could effectively retain and release 1-octen-3-ol, and induce the resistance of peach fruit diseases.

6.
Sci Rep ; 13(1): 14241, 2023 08 30.
Article in English | MEDLINE | ID: mdl-37648724

ABSTRACT

Few comparative studies have assessed metabolic brain changes in cognitive impairment among neurodegenerative disorders, and the posterior cingulate cortex (PCC) is a metabolically active brain region with high involvement in multiple cognitive processes. Therefore, in this study, metabolic abnormalities of the PCC were compared in patients with mild cognitive impairment (MCI) due to Parkinson's disease (PD) or Alzheimer's disease (AD), as examined by proton magnetic resonance spectroscopy (1H-MRS). Thirty-eight patients with idiopathic PD, including 20 with mild cognitive impairment (PDMCI) and 18 with normal cognitive function (PDN), 18 patients with probable mild cognitive impairment (ADMCI), and 25 healthy elderly controls (HCs) were recruited and underwent PCC 1H-MRS scans. Compared with HCs, patients with PDMCI exhibited significantly reduced concentrations of N-acetyl aspartate (NAA), total NAA (tNAA), choline (Cho), glutathione (GSH), glutamate + glutamine (Glx) and total creatine (tCr), while ADMCI cases exhibited significantly elevated levels of myo-inositol (Ins) and Ins/tCr ratio, as well as reduced NAA/Ins ratio. No significant metabolic changes were detected in PDN subjects. Compared with ADMCI, reduced NAA, Ins and tCr concentrations were detected in PDMCI. Besides, ROC curve analysis revealed that tCr concentration could differentiate PDMCI from PDN with an AUC of 0.71, and NAA/Ins ratio could differentiate patients with MCI from controls with normal cognitive function with an AUC of 0.74. Patients with PDMCI and ADMCI exhibited distinct PCC metabolic 1H-MRS profiles. The findings suggested cognitively normal PD patients with low NAA and tCr in the PCC might be at risk of preclinical PDMCI, and Ins and/or NAA/MI ratio in the PCC should be reconsidered a possible biomarker of preclinical MCI in clinical practice. So, comparing PCC's 1H-MRS profiles of cognitive impairment among neurodegenerative illnesses may provide useful information for better defining the disease process and elucidate possible treatment mechanisms.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Parkinson Disease , Aged , Humans , Parkinson Disease/complications , Gyrus Cinguli/diagnostic imaging , Cognitive Dysfunction/etiology , Creatine , Glutathione , Receptors, Antigen, T-Cell
7.
Int J Parasitol ; 53(10): 545-554, 2023 09.
Article in English | MEDLINE | ID: mdl-37150475

ABSTRACT

The horse genotype is one of three common Cryptosporidium spp. in equine animals and has been identified in some human cases. The species status of Cryptosporidium horse genotype remains unclear due to the lack of extensive morphological, biological, and genetic data. In the present study, we have conducted biological and whole genome sequence analyses of an isolate of the genotype from hedgehogs and proposed to name it Cryptosporidium equi n. sp. to reflect its common occurrence in equine animals. Oocysts of C. equi measured 5.12 ± 0.36 µm × 4.46 ± 0.21 µm with a shape index of 1.15 ± 0.08 (n = 50). Cryptosporidium equi was infectious to 3-week-old four-toed hedgehogs (Atelerix albiventris) and mice, with a prepatent period of 2-9 days and a patent period of 30-40 days in hedgehogs. It was not infectious to rats and rabbits. Phylogenetic analyses of small subunit rRNA, 70 kDa heat shock protein, actin, 60 kDa glycoprotein and 100 other orthologous genes revealed that C. equi is genetically distinct from other known Cryptosporidium species and genotypes. The sequence identity between C. equi and Cryptosporidium parvum genomes is 97.9%. Compared with C. parvum, C. equi has lost two MEDLE genes and one insulinase-like protease gene and gained one SKSR gene. In addition, 60 genes have highly divergent sequences (sequence differences ≥ 5.0%), including those encoding mucin-like glycoproteins, insulinase-like peptidases, and MEDLE and SKSR proteins. The genetic uniqueness of C. equi supports its increasing host range and the naming of it as a valid Cryptosporidium species. This is the first known use of whole genome sequence data in delineating new Cryptosporidium species.


Subject(s)
Cryptosporidiidae , Cryptosporidiosis , Cryptosporidium , Insulysin , Animals , Horses , Mice , Rats , Humans , Rabbits , Cryptosporidium/genetics , Phylogeny , Hedgehogs , Insulysin/genetics , Genotype , Feces
8.
Cell Death Dis ; 14(3): 179, 2023 03 06.
Article in English | MEDLINE | ID: mdl-36872411

ABSTRACT

Cholesterol metabolism plays a critical role in the progression of hepatocellular carcinoma (HCC), but it is not clear how cholesterol metabolism is regulated. The tubulin beta class I genes (TUBBs) are associated with the prognosis of many different cancers. To confirm the function of TUBBs in HCC, the Kaplan-Meier method and Cox analyses were performed using TCGA and GSE14520 datasets. A higher expression of TUBB2B is an independent prognostic factor for shorter over survival in HCC patients. Deletion of TUBB2B in hepatocytes inhibits proliferation and promotes tumor cell apoptosis, while over-expression of TUBB2B has the opposite function. This result was confirmed in a mouse xenograft tumor model. Mechanistically, TUBB2B induces the expression of CYP27A1, an enzyme responsible for the conversion of cholesterol to 27-hydroxycholesterol, which leads to the up-regulation of cholesterol and the progression of HCC. In addition, TUBB2B regulates CYP27A1 via human hepatocyte nuclear factor 4alpha (HNF4A). These findings indicated that TUBB2B functions as an oncogene in HCC, and plays a role in promoting cell proliferation and anti-apoptosis through targeting HNF4A/CYP27A1/cholesterol.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Humans , Mice , Apoptosis , Cholestanetriol 26-Monooxygenase , Cytochrome P-450 Enzyme System , Disease Models, Animal , Hepatocyte Nuclear Factor 4 , Hepatocytes , Oncogenes , Tubulin
9.
Crit Rev Food Sci Nutr ; : 1-14, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36876514

ABSTRACT

Lipopeptides, a class of compounds consisting of a peptide ring and a fatty acid chain, are secondary metabolites produced by Bacillus spp. As their hydrophilic and oleophilic properties, lipopeptides are widely used in food, medicine, environment and other industrial or agricultural fields. Compared with artificial synthetic surfactants, microbial lipopeptides have the advantages of low toxicity, high efficiency and versatility, resulting in urgent market demand and broad development prospect of lipopeptides. However, due to the complex metabolic network and precursor requirements of synthesis, the specific and strict synthesis pathway, and the coexistence of multiple homologous substances, the production of lipopeptides by microorganisms has the problems of high cost and low production efficiency, limiting the mass production of lipopeptides and large-scale application in industry. This review summarizes the types of Bacillus-produced lipopeptides and their biosynthetic pathways, introduces the versatility of lipopeptides, and describes the methods to improve the production of lipopeptides, including genetic engineering and optimization of fermentation conditions.

10.
J Prosthodont ; 32(5): 111-117, 2023 Jun.
Article in English | MEDLINE | ID: mdl-35848886

ABSTRACT

PURPOSE: To compare the accuracies of three intraoral scanners for shade determination function in vitro, and to preliminarily investigate the shade-matching characteristics of the three intraoral scanners. MATERIALS AND METHODS: The shade of the middle third region of each shade tab on the Vita Classical A1-D4 shade guide (VC) was measured with a spectrophotometer (Vita Easyshade V, VE) and three intraoral scanners, including CEREC Omnicam (OM), 3Shape TRIOS 3 (T3), and TRIOS 4 (T4). A conversion table between VC values and CIELAB values was established from the database of VE to analyze the trueness. The reproducibility of the instruments was then compared by repeating the measurements five times. RESULTS: The mean color difference for each instrument was highest in the OM, followed by the T4, and lowest in the T3 and VE, respectively. The L* and a* value for OM, and the b* value for T4, were significantly different from those for VE (p <0.05). The reproducibility of the instrument was highest in the VE (Fleiss' kappa: 0.95), followed by the T3 (Fleiss' kappa: 0.89), T4 (Fleiss' kappa: 0.87), and OM (Fleiss' kappa: 0.78). CONCLUSIONS: Of the three intraoral scanners, the trueness was best on the T3. The reproducibility of all the instruments was excellent.


Subject(s)
Prosthesis Coloring , Research Design , Reproducibility of Results , Spectrophotometry , Color
11.
Article in English | MEDLINE | ID: mdl-36212956

ABSTRACT

Objective: This study aimed to investigate the clinical effect of ultrasound-guided transradial catheterization (TRC) for ICU patients with shock. Methods: 120 shock patients registered in the ICU of our hospital from January 2019 to June 2022 were selected for prospective study. The control group (60 patients) were treated with palpation-guided TRC. The observation group was treated with ultrasound-guided TRC and was divided into the internal puncture group (internal TRC) and external puncture group (external TRC), with 30 cases in each. The first attempt success rate, total success rate, operation duration, complication, measurement of radial artery, and VAS scores were compared in these groups. Results: The success rate was higher in the observation group than in the control group (P < 0.05), and higher in the internal puncture group than in the external puncture group (P < 0.05). The first attempt success rate was significantly higher in the observation group than in the control group (P < 0.05), with no significant difference in between (P > 0.05). The number of attempts and operation duration were lower in the observation group than in the control group (P < 0.05), with significantly more operation duration in the internal puncture group than in the external puncture group (P < 0.05) and no significant difference in the number of attempts (both P > 0.05). The complication rate was significantly lower in the observation group than in the control group (P < 0.05) and there was no significant difference in between (P > 0.05). The radial artery diameter, cross-sectional area, and depth from the skin in the observation group were larger than those in the control group (P < 0.05) and there was no significant difference in between (P > 0.05). At 1, 6, 24, and 48 h after the surgery, the observation group showed lower VAS scores than the control group (P < 0.05). Conclusion: The ultrasound-guided TRC reduced the number of attempts, the complication rates, and the operation duration. For patients with shock, if Doppler ultrasound cannot detect blood flow, the success rate in the observation group was higher than that in the control group, and its advantage is worthy of promotion in severe patients.

12.
J Food Sci ; 87(10): 4569-4579, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36065890

ABSTRACT

To overcome defects of polyvinyl alcohol (PVA) and expand its applications in food preservation, PVA/Ag@SiO2 nanocomposite films were prepared using the solution intercalation film-casting method. Transmission electron microscopy, X-ray diffraction, and UV-visible absorption spectra were applied to confirm the synthesis of the nanoparticles (NPs). Effects of Ag@SiO2 NPs on physicochemical characteristics of films like viscosity, swelling ratio, tensile strength, elongation at break, as well as antibacterial activity were also evaluated. Results indicate that Ag@SiO2 NPs could be synthesized successfully, and the increasing concentration of Ag@SiO2 NPs led to the decrease in viscosity and the swelling ratio of the PVA/Ag@SiO2 NPs nanocomposite films. PVA/Ag@SiO2 nanocomposite films exhibited increased tensile strength and strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The films had higher antibacterial activity toward E. coli compared with S. aureus. Beef patties were applied to verify the practicality of PVA/Ag@SiO2 films. PVA/Ag@SiO2 NPs nanocomposite films act as an active food packaging system showing great potential in retaining food safety and prolonging the shelf-life of packaged foods. PRACTICAL APPLICATION: During the storage of fresh meat, the microbial count on the meat surface increased with increasing storage time; meat proteins could be broken down by microorganisms, causing the tissue structure to be destroyed, leading to loose muscle fibers and loss of nutrient-containing juices. In this paper, by improving the PVA film, a new antibacterial membrane was prepared, which can be used for fresh meat sold in supermarkets, as a lining at the bottom of the meat or directly covering the meat. The method can significantly decrease the number of microorganisms and extend the shelf-life of fresh meat.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Nanoparticles , Animals , Cattle , Polyvinyl Alcohol/chemistry , Staphylococcus aureus , Escherichia coli , Silicon Dioxide/chemistry , Silver/pharmacology , Silver/chemistry , Nanoparticles/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Meat Proteins
13.
J Phys Chem B ; 126(16): 3082-3089, 2022 04 28.
Article in English | MEDLINE | ID: mdl-35417159

ABSTRACT

The design of new aggregation-induced emission luminogens (AIEgens) has aroused continuous attention. The relationship between structure and performance plays an important role in guiding such efforts. In this contribution, two R-D-A- and R-D-π-A-type AIEgens were facilely designed and synthesized, that is, DPE-PTZ-CN and DPE-PTZ-PCN, with diphenylethylene as the twisted rotor structure (R), phenothiazine as electron-donor (D), and the (aryl) cyano group as electron-acceptor (A) fragments. Both luminophores were endowed with typical AIE properties, while their αAIE (PL intensity ratio of AIEgen in a mixed solution with water fraction (fw) = 90 vol % to that with fw = 0) were quite different. The αAIE for DPE-PTZ-CN was as high as 41, but it was only 3 for DPE-PTZ-PCN, in which the π-bridge (aryl linker) was introduced between its D and A groups. In addition, the push-pull electronic effect endowed both molecules with the feature of intramolecular charge transfer (ICT). The solvatochromism effect observed in solutions with different polarities confirmed the existence of the ICT process. The theoretical calculation and single crystal structure analysis revealed that the electronic structure and molecular conformation characteristics had a decisive influence on the differences in photophysical behaviors.


Subject(s)
Fluorescent Dyes , Electronics , Fluorescent Dyes/chemistry , Molecular Conformation
14.
J Adv Prosthodont ; 14(1): 1-11, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35284056

ABSTRACT

PURPOSE: The maximum width between the mesial and distal labial transitional line angles, described as "esthetic width" herein, could significantly influence the visual perception of the teeth and smile. This study aimed to conduct biometric research on esthetic width and to explore whether regular distribution exists in the esthetic width of human teeth. MATERIALS AND METHODS: A total of 4,264 maxillary and mandibular anterior teeth were measured using the Geomagic studio software program. The proportions of maxillary to mandibular homonymous teeth and proportions between the adjacent teeth were calculated. Bilateral symmetry and the correlation between the esthetic and mesiodistal widths were both accounted for during the measurement procedures. RESULTS: The mean esthetic widths were 6.773 ± 0.518 mm and 4.329 ± 0.331 mm for maxillary and mandibular central incisors, respectively, 5.451 ± 0.487 mm and 5.008 ± 0.351 mm for maxillary and mandibular lateral incisors, respectively, and 3.340 ± 0.353 mm and 5.958 ± 0.415 mm for maxillary and mandibular canines, respectively. Except for the mandibular canines, no significant difference in esthetic width was found among homonymous teeth from the same jaw. A high linear correlation was found between the esthetic and mesiodistal widths of the same tooth, except for the maxillary canines. Esthetic width proportions among different tooth categories showed some regular patterns, which were similar to those of the mesiodistal width. CONCLUSION: Esthetic width is regularly distributed among the teeth in the Chinese population. This could provide an important reference for anterior dental restorations and dimension recovery in esthetic reconstruction of anterior teeth.

15.
Odontology ; 110(4): 759-768, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35212853

ABSTRACT

To compare the accuracy of visual and instrumental methods for tooth-color matching based on three attributes in the Munsell color system and to investigate the characteristics of intraoral scanners for tooth-color matching. Shades of the cervical, middle, and incisal third region of 130 maxillary anterior teeth were matched visually by an experienced prosthodontist (EP) using Vita classical A1-D4 (VC) and Vita System 3D-Master (V3D) shade guides, and digitally by a spectrophotometer (Vita Easyshade V, VE) and two intraoral scanners (3Shape TRIOS 3, T3; TRIOS 4, T4). VE was used as a reference. The reproducibility of the three test groups was examined by repeating the measurements in triplicate. The overall trueness of the three test groups (from high to low) was T3 > EP > T4 for VC values (p < 0.01), and T3, EP > T4 (p < 0.01) for V3D. The trueness of T3 in incisal regions was lower than cervical and middle regions. When hue or lightness was correct, the mismatched chroma in test groups was smaller than VE (p < 0.01). The repeatability of EP was the poorest (p < 0.01). The color-matching trueness of T3 was higher than EP and T4. The reproducibility of intraoral scanners was better than visual methodology.


Subject(s)
Prosthesis Coloring , Tooth , Color , Reproducibility of Results , Spectrophotometry
16.
Chemistry ; 28(24): e202200480, 2022 Apr 27.
Article in English | MEDLINE | ID: mdl-35179269

ABSTRACT

Defunctionalization of readily available feedstocks to provide alkenes for the synthesis of multifunctional molecules represents an extremely useful process in organic synthesis. Herein, we describe a transition metal-free, simple and efficient strategy to access alkyl 1,2-bis(boronate esters) via regio- and diastereoselective diboration of secondary and tertiary alkyl halides (Br, Cl, I), tosylates, and alcohols. Control experiments demonstrated that the key to this high reactivity and selectivity is the addition of a combination of potassium iodide and N,N-dimethylacetamide (DMA). The practicality and industrial potential of this transformation are demonstrated by its operational simplicity, wide functional group tolerance, and the late-stage modification of complex molecules. From a drug discovery perspective, this synthetic method offers control of the position of diversification and diastereoselectivity in complex ring scaffolds, which would be especially useful in a lead optimization program.


Subject(s)
Inorganic Chemicals , Transition Elements , Alcohols , Alkenes , Chemistry Techniques, Synthetic , Esters
17.
Food Microbiol ; 101: 103891, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34579851

ABSTRACT

In recent years, more attention has been paid to the application of cold plasma (CP) in eliminating foodborne pathogenic bacteria. This work investigated CP effects on inactivation kinetics and cell envelopes of Listeria monocytogenes (L. monocytogenes) and Salmonella Enteritidis (S. Enteritidis). Bacterial suspensions were treated with dielectric barrier discharge atmospheric CP at 75 kV for different treatment time. Three regression models were tested for estimating inactivation kinetics. Reactive species generated in plasma, the appearance and integrity of bacterial cells, the activity and secondary structure of enzymes in the cell envelope, and molecular docking, were measured for evaluating the envelope damages. Results indicated that Log-linear model was suitable for L. monocytogenes and the Weibull model was suitable for S. Enteritidis. S. Enteritidis was more sensitive to short-lived reactive species (such as OH radicals) in plasma than L. monocytogenes, and the cell envelope of S. Enteritidis was more severely damaged (the increased membrane permeability and leakage of intracellular substances) after plasma treatment. Interestingly, compared with S. Enteritidis, the decrease in the activity of enzymes existing in the cell envelope of L. monocytogenes did not contribute significantly to the death of bacteria. Molecular docking further suggested that the decrease in the enzyme activity might be due to the modification of the enzyme, by the interaction between reactive species in plasma (H2O2) and amino acid residues of the enzyme through the hydrogen bond.


Subject(s)
Cell Membrane , Cold Temperature , Listeria monocytogenes , Plasma Gases , Salmonella enteritidis , Cell Membrane/drug effects , Hydrogen Peroxide , Kinetics , Listeria monocytogenes/drug effects , Molecular Docking Simulation , Plasma Gases/pharmacology , Salmonella enteritidis/drug effects
18.
Chemistry ; 28(3): e202103866, 2022 Jan 13.
Article in English | MEDLINE | ID: mdl-34713940

ABSTRACT

A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2 neop2 ), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.


Subject(s)
Esters , Sulfones
19.
Chem Commun (Camb) ; 58(3): 395-398, 2022 Jan 04.
Article in English | MEDLINE | ID: mdl-34901977

ABSTRACT

A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds of a cyclic sulfone via Cu-free or Cu-mediated processes generates the corresponding sulfinate salts, which can be further derivatised to provide sulfonyl-containing boronate esters, such as sulfones and sulfonyl fluorides.

20.
Foods ; 10(12)2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34945530

ABSTRACT

This study aimed to investigate effects of plasma-activated solution (PAS) on the cell biology of Staphylococcus aureus and qualities of fresh lettuce leaves. PAS was prepared by dielectric barrier discharge plasma and incubated with S. aureus for 10-30 min or with lettuces for 10 min. Effects on cell biology were evaluated with microscopic images, cell integrity, and chemical modification of cellular components. Effects on lettuce quality were estimated with the viable microbial counts, color, contents of vitamin C and chlorophyll, and surface integrity. PAS reduced S. aureus population by 4.95-log and resulted in increased cell membrane leakage. It also resulted in increased contents of reactive oxygen species in cells, C=O bonds in peptidoglycan, and 8-hydroxydeoxyguanosine content in cellular DNA, and reduced ratios of unsaturated/saturated fatty acids in the cell membrane. PAS treatment reduced bacterial load on fresh lettuce and had no negative effects on the quality. Data suggest that PAS can be used for the disinfection of ready-to-eat fresh vegetables.

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