Insight into the Manipulation Mechanism of Polymorphic Transformation by Polymers: A Case of Cimetidine.

PURPOSE: Employing polymer additives is an effective strategy to realize the manipulation of polymorphic transformation. However, the manipulation mechanism is still not clear, which limit the precise selection of polymeric excipients and the development of pharmaceutical formulations. METHODS: The solubility of cimetidine (CIM) in acetonitrile/water mixtures were measured. And the polymorphic transformation from CIM form A to form B with the addition of different polymers was monitored by Raman spectroscopy. Furthermore, the manipulation effect of polymers was determined based on the results of experiments and molecular simulations. RESULTS: The solubility of form A is consistently higher than that of form B, which indicate that form B is the thermodynamically stable form within the examined temperature range. The presence of polyvinylpyrrolidone (PVP) of a shorter chain length could have a stronger inhibitory effect on the phase transformation process of metastable form, whereas polyethylene glycol (PEG) had almost no impact. The nucleation kinetics experiments and molecular dynamic simulation results showed that only PVP molecules could significantly decrease the nucleation rate of CIM, due to the ability of reducing solute molecular diffusion and solute-solute molecular interaction. A combination of crystal growth rate measurements and calculations of the interaction energies between PVP and the crystal faces of CIM indicate that smaller molecular weight PVP can suppress crystal growth more effectively. CONCLUSION: PVP K16-18 has more impact on the stabilization of CIM form A and inhibition of the phase transformation process. The manipulation mechanism of polymer additives in the polymorphic transformation of CIM was proposed.

A Study on the Aesthetic Parameters and Proportions of the External Contour for Minimally Invasive Facial Injection.

OBJECTIVE: The aim of this study was to further guide the diagnosis and treatment programs for clinical facial contouring with injectable fillers by studying the facial contour parameters and proportion preferences consistent with Asian aesthetics. METHODS: A total of 89 subjects (42 males and 47 females aged 20-60 years) who met the inclusion criteria were enrolled in this study. The subjects were grouped by age, sex, and external contour attractiveness score, and the external contour aesthetic parameters and proportions of the subjects in different groups were measured and analysed. RESULTS: The upper facial breadth and lower facial breadth decreased with age, with significant differences between the 50-60-year age group and other age groups (P < 0.01). The nasomental angle showed a decreasing trend with age, with significant differences between the 40-49-year age group and the 20-29-year and 30-39-year age groups (P < 0.05). Males and females were significantly different in calva height, total head height, lower facial height, and calva height to total head height ratio (P < 0.05). With increasing age, the external contour attractiveness scores of males and females both showed decreasing trends, with significant differences between the 50-60-year age group and other age groups (P < 0.05). CONCLUSION: The calva height and the cranioauricular angle have a significant impact on external contour attractiveness. In general, temporal depression, cheek sagging, lateral cheek depression, and an ill-defined mandibular border will occur due to ageing, collagen loss, ligament laxity and sagging, and soft tissue atrophy and sagging, reducing the attractiveness of the external contour. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The outcome of sutured wounds compared with tissue adhesive for paediatric wound closure: A meta-analysis.

A meta-analysis investigation was executed to measure the outcome of sutured wounds (SWs) compared with tissue adhesive (TA) for paediatric wound closure (PWC). A comprehensive literature inspection till February 2023 was applied and 2018 interrelated investigations were reviewed. The 18 chosen investigations enclosed 1697 children with PWC in the chosen investigations' starting point, 977 of them were utilising SWs, and 906 were utilising TA. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to compute the value of the effect of SWs compared with TA for PWC by the dichotomous approaches and a fixed or random model. SWs had significantly higher wound cosmetic (WC) scores (mean deviation [MD], 1.70; 95% CI, 0.57-2.84, P = .003), lower wound dehiscence (WD) (OR 0.60; 95% CI, 0.06-0.43, P < .001), and lower cost (MD, -10.22; 95% CI, -10.94 to -9.50, P < .001) compared with those with TA in PWC. No significant difference was found between children utilising SWs and TA in wound infection (WI) (OR, 0.45; 95% CI, 0.15-1.30, P = .14) with no heterogeneity (I2 = 0%) in PWC. SWs had significantly higher WC scores, lower WD, and lower cost, yet, no significant difference was found in WI compared with those with TA in PWC. However, care must be exercised when dealing with its values because of the low sample size of some of the nominated investigations and the low number of selected investigations for the meta-analysis.

Rapid Determination of Cellulose and Hemicellulose Contents in Corn Stover Using Near-Infrared Spectroscopy Combined with Wavelength Selection.

The contents of cellulose and hemicellulose (C and H) in corn stover (CS) have an important influence on its biochemical transformation and utilization. To rapidly detect the C and H contents in CS by near-infrared spectroscopy (NIRS), the characteristic wavelength selection algorithms of backward partial least squares (BIPLS), competitive adaptive reweighted sampling (CARS), BIPLS combined with CARS, BIPLS combined with a genetic simulated annealing algorithm (GSA), and CARS combined with a GSA were used to select the wavelength variables (WVs) for C and H, and the corresponding regression correction models were established. The results showed that five wavelength selection algorithms could effectively eliminate irrelevant redundant WVs, and their modeling performance was significantly superior to that of the full spectrum. Through comparison and analysis, it was found that CARS combined with GSA had the best comprehensive performance; the predictive root mean squared errors of the C and H regression model were 0.786% and 0.893%, and the residual predictive deviations were 3.815 and 12.435, respectively. The wavelength selection algorithm could effectively improve the accuracy of the quantitative analysis of C and H contents in CS by NIRS, providing theoretical support for the research and development of related online detection equipment.

Rapid detection of cellulose and hemicellulose contents of corn stover based on near-infrared spectroscopy combined with chemometrics.

The feasibility of near-infrared spectroscopy (NIRS) combined with chemometrics for the rapid detection of the cellulose and hemicellulose contents in corn stover is discussed. Competitive adaptive reweighted sampling (CARS) and genetic simulated annealing algorithm (GSA) were combined (CARS-GSA) to select the characteristic wavelengths of cellulose and hemicellulose and to reduce the dimensionality and multicollinearity of the NIRS data. The whole spectra contained 1845 wavelength variables. After CARS-GSA optimization, the number of characteristic wavelengths of cellulose (hemicellulose) was reduced to 152 (260), accounting for 8.24% (14.09%) of all wavelengths. The coefficients of determination of the regression models for predicting the cellulose and hemicellulose contents were 0.968 and 0.996, the root mean square errors of prediction (RMSEPs) were 0.683 and 0.648, and the residual predictive deviations (RPDs) were 5.213 and 16.499, respectively. The RMSEP of the cellulose and hemicellulose regression models was 0.152 and 0.190 lower for CARS-GSA than for the full-spectrum, and the RPD was increased by 0.949 and 3.47, respectively. The results showed that the CARS-GSA model substantially reduced the number of characteristic wavelengths and significantly improved the predictive ability of the regression model.

The immunogenic reaction and bone defect repair function of ε-poly-L-lysine (EPL)-coated nanoscale PCL/HA scaffold in rabbit calvarial bone defect.

Tissue engineering is a promising strategy for bone tissue defect reconstruction. Immunogenic reaction, which was induced by scaffolds degradation or contaminating microorganism, influence cellular activity, compromise the efficiency of tissue engineering, or eventually lead to the failure of regeneration. Inhibiting excessive immune response through modulating scaffold is critical important to promote tissue regeneration. Our previous study showed that ε-poly-L-lysine (EPL)-coated nanoscale polycaprolactone/hydroxyapatite (EPL/PCL/HA) composite scaffold has enhanced antibacterial and osteogenic properties in vitro. However, the bone defect repair function and immunogenic reaction of EPL/PCL/HA scaffolds in vivo remains unclear. In the present study, three nanoscale scaffolds (EPL/PCL/HA, PCL and PCL/HA) were transplanted into rabbit paraspinal muscle pouches, and T helper type 1 (Th1), T helper type 2 (Th2), T helper type 17 (Th17), and macrophage infiltration were analyzed after 1 week and 2 weeks to detect their immunogenic reaction. Then, the different scaffolds were transplanted into rabbit calvarial bone defect to compare the bone defect repair capacities. The results showed that EPL/PCL/HA composite scaffolds decreased pro-inflammatory Th1, Th17, and type I macrophage infiltration from 1 to 2 weeks, and increased anti-inflammatory Th2 infiltration into the regenerated area at 2 weeks in vivo, when compared to PCL and PCL/HA. In addition, EPL/PCL/HA showed an enhanced bone repair capacity compared to PCL and PCL/HA when transplanted into rabbit calvarial bone defects at both 4 and 8 weeks. Hence, our results suggest that EPL could regulate the immunogenic reaction and promote bone defect repair function of PCL/HA, which is a promising agent for tissue engineering scaffold modulation.

Oxygen Plasma Technology-Assisted Preparation of Three-Dimensional Reduced Graphene Oxide/Polypyrrole/Strontium Composite Scaffold for Repair of Bone Defects Caused by Osteoporosis.

Repairs of bone defects caused by osteoporosis have always relied on bone tissue engineering. However, the preparation of composite tissue engineering scaffolds with a three-dimensional (3D) macroporous structure poses huge challenges in achieving osteoconduction and osteoinduction for repairing bone defects caused by osteoporosis. In the current study, a three-dimensional macroporous (150-300 µm) reduced graphene oxide/polypyrrole composite scaffold modified by strontium (Sr) (3D rGO/PPY/Sr) was successfully prepared using the oxygen plasma technology-assisted method, which is simple, safe, and inexpensive. The findings of the MTT assay and AO/EB fluorescence double staining showed that 3D rGO/PPY/Sr has a good biocompatibility and effectively promoted MC3T3-E1 cell proliferation. Furthermore, the ALP assay and alizarin red staining showed that 3D rGO/PPY/Sr increased the expression levels of ALP activity and the formation of calcified nodules. The desirable biocompatibility, osteoconduction, and osteoinduction abilities, assure that the 3D macroporous rGO/PPY/Sr composite scaffold offers promising potential for use in the repair of bone defects caused by osteoporosis in bone tissue engineering.

Preparation of mPEG-b-PLA/TM-2 Micelle Lyophilized Products by Mixed Lyoprotectors and Antitumor Effect In Vivo.

The objective of this study was to encapsulate the poorly water-soluble drug TM-2 into polymer micelles using mPEG2k-b-PLA2.4k to increase its aqueous solubility and improve its therapeutic effect for liver cancer. Furthermore, in order to achieve long-term storage, the micelle solution was successfully freeze-dried. This study theoretically clarified the possibility of enhancing the water solubility of TM-2 using mPEG2k-b-PLA2.4k micelles as well as the protective effects of mixed lyoprotectants. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were performed, which showed that the drug has a good affinity with the polymer (χ = 0.489) according to Flory-Huggins theory and that lyoprotectants reduced the crystallinity of PEG in mPEG2k-b-PLA2.4k and played a space-protective role in the lyophilization process. In vivo experiments showed that micellization could improve the drug bioavailability and give a high therapeutic effect with a tumor inhibition rate of 84.5% under the tolerated dose.

Toxicity Reduction and Efficacy Promotion of Doxorubicin in the Treatment of Breast Tumors Assisted by Enhanced Oral Absorption of Curcumin-Loaded Lipid-Polyester Mixed Nanoparticles.

Curcumin (CUR), a polyphenol derived from turmeric, exhibits anticancer and anti-inflammatory properties. However, it has poor water solubility, stability, and oral bioavailability. To overcome these limitations, lipid-polyester mixed nanoparticles (NPs) embedded in enteric polymer-EudragitL100-55(Eu) were formulated (CUR-NPs-Eu). NPs composed of mPEG-b-PCL have a hybrid core made up of middle chain triglyceride (MCT) and poly(ε-caprolactone) (PCL) for enhancing drug loading. The CUR-NPs with MCT content of 10% had a particle size of 121.2 ± 16.8 nm, ζ potential of -16.25 ± 1.38 mV, drug loading of 9.8%, and encapsulation efficiency of 87.4%. The transport of the CUR-NPs-Eu across Caco-2 monolayers is enhanced compared with CUR alone (1.98 ± 0.94 × 10-6 of curcumin versus 55.43 ± 6.06 × 10-6 cm/s of curcumin-loaded NPs) because of the non-disassociated nanostructure during absorption. The absolute bioavailability of CUR-NPs-Eu was 7.14%, which was drastically improved from 1.08% of the CUR suspension (CUR-Sus). Therefore, in the xenograft 4T1 tumor-bearing mice, increased drug accumulation in heart and tumor was noticed because of enhanced oral bioavailability of CUR. The chemosensitizing effect of CUR was attributed to its NF-κB reduction effect (148 ± 11.83 of DOX alone versus 104 ± 8.71 of combined therapy, ng/g tissue). The cardioprotective effect of CUR was associated with maintenance of cardiac antioxidant enzyme activity and down-regulation of NF-κB. This study provided a partial illustration of the mechanisms of chemosensitizing and cardioprotective effects of CUR utilizing the oral availability promotion effect brought by the NPs-Eu formulation. And these results further demonstrated that the capability of this NPs-Eu system in oral delivery of poorly soluble and poorly permeable drugs.

Acute and subchronic toxicity of Ag+-laden liposomes on Daphnia magna: the effect of encapsulation.

The toxic effects of various substances on Daphnia magna (D. magna) observed through traditional waterborne uptake may involve alterations to the nutritional quality of the contaminated algae and culture media. It is essential to find an alternative delivery method that will not affect the nutritional quality of D. magna's diet in order to elucidate the mechanisms of dietary metal toxicity. Therefore, this study examined the application of liposome encapsulation on the dietary toxicity of D. magna. Ag+-laden liposomes were prepared and the Ag encapsulation efficiency and inhibition effect on algae growth were examined. Then, acute and 14-day subchronic studies were performed to examine the effect of Ag+-laden liposomes on D. magna. The EC50 for the 24 h immobilization test was 10.59 µg/L for Ag+-laden liposomes and 3.07 µg/L for Ag+. In terms of subchronic effects, the estimated ECx values under the Ag+-laden liposome condition were always higher than the direct exposure condition. Furthermore, the bioaccumulation of Ag+-laden liposomes was about 1.68 times lower than direct exposure. Generally, Ag+-laden liposomes produced less efficient toxicity than direct exposure, e.g., lower D. magna mortality, production of more neonates, higher intrinsic rate of natural increase (rm), earlier time to first brood, and higher enzyme activities.

The cotton XLIM protein (GhXLIM6) is required for fiber development via maintaining dynamic F-actin cytoskeleton and modulating cellulose biosynthesis.

LIM domain proteins are cysteine-rich proteins, and are often considered as actin bundlers and transcription factors in plants. However, the roles of XLIM proteins in plants (especially in cotton) remain unexplored in detail so far. In this study, we identified a cotton XLIM protein (GhXLIM6) that is preferentially expressed in cotton fiber during whole elongation stage and early secondary cell wall (SCW) synthesis stage. The GhXLIM6-silenced transgenic cotton produces shorter fibers with thinner cell walls, compared with wild-type (WT). GhXLIM6 protein could directly bind F-actin and promote actin polymerization both in vitro and in vivo. It also acts as a transcription factor to suppress GhKNL1 expression through binding the PAL-box element of GhKNL1 promoter, and subsequently regulate the expression of CesA genes related to cellulose biosynthesis and deposition in SCWs of cotton fibers. The cellulose content in fibers of GhXLIM6RNAi cotton is lower than that in WT. Taken together, these data reveal the dual roles of GhXLIM6 in fiber development. On one hand, GhXLIM6 functions in fiber elongation through binding to F-actin to maintain the dynamic F-actin cytoskeleton. On the other hand, GhXLIM6 fine-tunes fiber SCW formation, probably through directly suppressing transcription of GhKNL1 to promote cellulose biosynthesis.

Space-confined pyrolysis for fabrication of peacods-like Fe3O4@C-Ni nanostructures for catalysis and protein adsorption.

A unique nanostructure of Fe3O4 nanoparticles (NPs)-in/carbon layer/out-Ni NPs was developed and proved to be an efficient catalyst and protein adsorbent. This kind of nanostructure was formed through a space-confined pyrolysis procedure using polydopamine-Ni2+ coated Fe-NTA nanowires as the precursor. A N-doped carbon interlayer derived from polydopamine (PDA) supported a large amount of Ni NPs and entrapped well-defined Fe3O4 NPs, which were obtained through reduction of Ni2+, Fe3+ by carbonized NTA groups and a PDA layer. The contributions of the unique configuration along with the high density of Ni NPs in Fe3O4@C-Ni are significant for improving catalysis and protein adsorption performance, which is expected to be a promising alternative to other conventional catalysts and protein adsorbents. Due to the unique novel nanostructure, this nanocomposite possesses a wide range of applications, not only for catalytic reactions but also for other inhomogeneous reactions.

Nano-Crystalline Sandwich Formed in Polylactic Acid Fibers.

Fibers have traditionally been made through melt or solution processes from macromolecules. Most of these fibers have crystalline domains where the segregation of different crystalline features is extremely difficult due to the statistical nature of the formation and growth of these domains. A fibrous nano-crystalline sandwich is reported where distinctly different crystalline regions are formed in layers along the continuous fiber direction during the spinning process and locked in place. This approach employs side-by-side bicomponent nanofiber electrospinning where the components are the enantiomeric pair of poly(l-lactic acid) and poly(d-lactic acid). The formation of the poly(lactic acid) (PLA) stereo-complexes at the junction interphase of the two components is demonstrated through diffusion, which subsequently crystallize into continuous sandwich domains. The stereo-complex crystalline core in the fiber possesses a melting point 50 °C higher than, and properties substantially different from, the regular PLAs at the fringe areas of the fiber. This nano-crystalline sandwich fiber structure can be scaled to the micrometers in a commercial bicomponent process.

Co-delivery of paclitaxel and gemcitabine by methoxy poly(ethylene glycol)-poly(lactide-coglycolide)-polypeptide nanoparticles for effective breast cancer therapy.

Traditional chemotherapeutic drugs have shown limited clinical curative effects in antitumor therapy. The application of multidrug combination and adjuvant-drug carriers is a feasible strategy to overcome the limitations while minimizing the dosage of single drug and acquiring the synergistic effects in tumor therapy. However, the systemic toxicity, drug resistance, and tumor recurrence are still unavoidable. Here we develop core-shell nanoparticles (NPs) to encapsulate paclitaxel (PTX) and gemcitabine (GEM) for breast cancer therapy. We find that the NPs could encapsulate PTX and GEM, with an encapsulation efficiency of 96.3 and 95.13%, respectively. Moreover, the drug loading of these NPs is 2.71% (PTX) and 2.64% (GEM). Notably, the co-delivery of GEM and PTX performs enhanced anticancer effect compared with the PTX alone or GEM alone therapy at the same concentration, which indicates a synergistic effect. Moreover, encapsulation of PTX and GEM by methoxy poly(ethylene glycol)-poly(lactide-coglycolide) also shows enhanced anticancer effects (81.5% tumor inhibition) and reduced systemic toxicity in vivo compared with free drugs (65% tumor inhibition). Together with those results, co-delivery of PTX and GEM by methoxy poly(ethylene glycol)-poly(lactide-coglycolide) might have important potencies in clinical applications for breast cancer therapy.

Novel Magnetic Cross-Linked Cellulase Aggregates with a Potential Application in Lignocellulosic Biomass Bioconversion.

The utilization of renewable biomass resources to produce high-value chemicals by enzymatic processes is beneficial for alternative energy production, due to the accelerating depletion of fossil fuels. As immobilization techniques can improve enzyme stability and reusability, a novel magnetic cross-linked cellulase aggregate has been developed and applied for biomass bioconversion. The crosslinked aggregates could purify and immobilize enzymes in a single operation, and could then be combined with magnetic nanoparticles (MNPs), which provides easy separation of the materials. The immobilized cellulase showed a better activity at a wider temperature range and pH values than that of the free cellulase. After six cycles of consecutive reuse, the immobilized cellulase performed successful magnetic separation and retained 74% of its initial activity when carboxylmethyl cellulose (CMC) was used as the model substrate. Furthermore, the structure and morphology of the immobilized cellulase were studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Moreover, the immobilized cellulase was shown to hydrolyze bamboo biomass with a yield of 21%, and was re-used in biomass conversion up to four cycles with 38% activity retention, which indicated that the immobilized enzyme has good potential for biomass applications.

Incorporation of VSV-G produces fusogenic plasma membrane vesicles capable of efficient transfer of bioactive macromolecules and mitochondria.

The objective of this study was to determine if plasma membrane vesicles (PMVs) could be exploited for efficient transfer of macro-biomolecules and mitochondria. PMVs were derived from mechanical extrusion, and made fusogenic (fPMVs) by incorporating the glycoprotein G of vesicular stomatitis virus (VSV-G). Confocal microscopy examination revealed that cytoplasmic proteins and mitochondria were enclosed in PMVs as evidenced by tracing with cytoplasmically localized and mitochondria-targeted EGFP, respectively. However, no fluorescence signal was detected in PMVs from cells whose nucleus was labeled with an EGFP-tagged histone H2B. Consistently, qRT-PCR measurement showed that mRNA, miRNA and mitochondrial DNA decreased slightly; while nuclear DNA was not measureable. Further, Western blot analysis revealed that cytoplasmic and membrane-bound proteins fell inconspicuously while nuclear proteins were barely detecsle. In addition, fPMVs carrying cytoplamic DsRed proteins transduced about ~40 % of recipient cells. The transfer of protein was further confirmed by using the inducible Cre/loxP system. Mitochondria transfer was found in about 20 % recipient cells after incubation with fPMVs for 5 h. To verify the functionalities of transferred mitochondria, mitochodria-deficient HeLa cells (Rho0) were generated and cultivated with fPMVs. Cell enumeration demonstrated that adding fPMVs into culture media stimulated Rho0 cell growth by 100 % as compared to the control. Lastly, MitoTracker and JC-1 staining showed that transferred mitochondria maintained normal shape and membrane potential in Rho0 cells. This study established a time-saving and efficient approach to delivering proteins and mitochondria by using fPMVs, which would be helpful for finding a cure to mitochondria-associated diseases. Graphical abstract Schematic of the delivery of macro-biomolecules and organelles by fPMVs. VSV-G-expressing cells were extruded through a 3 µm polycarbonate membrane filter to generate fusogenic plasma membrane vesicles (fPMVs), which contain bioactive molecules and organelles but not the nucleus. fPMVs can be endocytosed by target cells, while the cargo is released due to low-pH induced membrane fusion. These nucleus-free fPMVs are efficient at delivery of cytoplasmic proteins and mitochondria, leading to recovery of mitochondrial biogenesis and proliferative ability in mitochondria-deficient cells.

Lipase-catalyzed synthesis of azido-functionalized aliphatic polyesters towards acid-degradable amphiphilic graft copolymers.

A series of novel aliphatic polyesters with azido functional groups were synthesized via the direct lipase-catalyzed polycondensation of dialkyl diester, diol and 2-azido-1,3-propanediol (azido glycerol) using immobilized lipase B from Candida antarctica (CALB). The effects of polymerization conditions including reaction time, temperature, enzyme amount, substrates and monomer feed ratio on the molecular weights of the products were studied. The polyesters with pendant azido groups were characterized by (1)H NMR, (13)C NMR, 2D NMR, FTIR, GPC and DSC. Alkyne end-functionalized poly(ethylene glycol) containing a cleavable acetal group was then grafted onto the polyester backbone by copper-catalyzed azide-alkyne cycloaddition (CuAAC, click chemistry). Using fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM), these amphiphilic graft copolymers were found to readily self-assemble into nanosized micelles in aqueous solution with critical micelle concentrations between 0.70 and 1.97 mg L(-1), and micelle sizes from 20-70 nm. The degradation of these polymers under acidic conditions was investigated by GPC and (1)H NMR spectroscopy. Cell cytotoxicity tests indicated that the micelles had no apparent cytotoxicity to Bel-7402 cells, suggesting their potential as carriers for controlled drug delivery.

A 3-dimensional finite element analysis of the restoration of the maxillary canine with a complex zirconia post system.

STATEMENT OF PROBLEM: Zirconia posts exhibit high strength and toughness, but reliable bonding with the resin core is difficult to attain. The use of a ferrule has been found to improve stress distribution in the root of endodontically treated teeth. PURPOSE: The purpose of this finite element analysis study was to measure the stress distribution in the post-core system and root structure of a maxillary canine. MATERIAL AND METHODS: A right maxillary canine was embedded and subjected to a micro-computed tomography scan. Three-dimensional dynamic scan data were then transformed, and a finite element model of 4 dentin ferrule heights was designed with zirconia posts and heat-pressed glass ceramics for a complete crown restoration. Von Mises stresses were determined by applying a 300 N static load to the middle of the lingual surface of the crown. RESULTS: When the ferrule height increased from 0 to 3 mm, the maximum von Mises stress of the zirconia post decreased from 196 to 149 MPa, and that on the zirconia post-dentin interface decreased from 174 to 132 MPa. The maximum von Mises stress decreased from 39.8 to 32.5 MPa in the apical root and from 59.5 to 49.9 MPa in the mid-root when the ferrule height increased from 0 to 3 mm. CONCLUSIONS: Increased ferrule height is associated with reduced von Mises stress in the zirconia post and the post-dentin interface, with an apparent shift of von Mises stress to the root cervical area from the mid-root and the apex.

A comprehensive review of the botany, phytochemistry, pharmacology, and toxicology of Murrayae Folium et Cacumen.

Ethnopharmacological relevance: Murrayae Folium et Cacumen (MFC) is a plant considered to be a traditional Chinese medicine with culinary value as well. The dry leaves and twigs of Murraya paniculata and M. exotica are used to treat stomach aches, rheumatism, toothaches, swelling, and insect and snake bites. They are also used to prepare spicy chicken dishes. Aim of the review: This review comprehensively summarizes the available information on the botanical characterization, phytochemistry, pharmacological activities, pharmacodynamics, pharmacokinetics, and toxicity of MFC. Methods: Relevant scientific literature up to August 2023 was included in the study. Chinese and English studies on MFC were collected from databases, including PubMed, Elsevier, Web of Science, Springer, Science Direct, Wiley, ACS, and CNKI (Chinese). Doctoral and Master's dissertations were also included. Results: In total, 720 compounds have been identified and reported in the literature, including flavonoids, coumarins, alkaloids, sterols, phenylpropenols, organic acids, spirocyclopentenones, and volatile oils. Flavonoids and coumarins are the two most important bioactive compounds responsible for these pharmacological activities. MFC has anti-inflammatory, anti-bacterial, anti-microbial, anti-diabetic, anti-tumor, anti-oxidant, anti-depressant, potential anti-Alzheimer's disease, chondroprotective, and analgesic properties. The pharmacological effects include interrupting the STAT3/NF-κB/COX-2 and EGFR signaling pathways, downregulating EpCAM expression, inhibiting NF-κB and ERK signals, inhibiting the EP/cAMP/PKA signaling pathway and miR-29a/Wnt/ß-catenin signaling activity, and upregulating Foxo3a expression. Conclusion: This review demonstrates that the chemical constituents, pharmacological activities, pharmacodynamics, pharmacokinetics, and toxicity of MFC support its use in traditional Chinese botanical medicines. MFC contains a wide range of chemical compounds. Flavonoids and coumarins promote strong pharmacological activity and, are low-toxicity natural phytomedicines that are widely used in medicine, food, ornamentation, and cosmetics, making MFC a promising compound for development and use in the treatment of several medical conditions.

Preparation of surface molecularly imprinted polymers with Fe3O4/ZIF-8 as carrier for detection of Dimethoate in cabbage.

In this study, molecularly imprinted polymers (MIPs) were prepared for the specific recognition of organophosphorus pesticides and a rapid, efficient and simple method was established for the detection of dimethoate (DIT) in food samples. Fe3O4 magnetic nanoparticles were synthesized by co-precipitation, and Fe3O4/ZIF-8 complexes were prepared by a modified in-situ polymerization method, and then magnetic molecularly imprinted polymers (MMIPs) were prepared and synthetic route was optimized by applying density functional theory (DFT). The morphological characterization showed that the MMIPs were coarse porous spheres with an average particle size of 50 nm. The synthesized materials are highly selective for the organophosphorus pesticide dimethoate with an adsorption capacity of 461.50 mg·g-1 and are effective resistance to matrix effects. A novel method for the determination of DIT in cabbage was developed using the prepared MMIPs in combination with HPLC. The practical results showed that the method can meet the requirements for the determination of DIT in cabbage with recoveries of 85.6-121.1 % and detection limits of 0.033 µg·kg-1.