Exploration of making removable partial denture by digital technology / 中华口腔医学杂志

To explore the digital manufacturing process of distal extension removable partial denture. From November 2021 to December 2022, 12 patients (7 males and 5 females) with free-ending situation were selected from the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University. Three-dimensional model of the relationship between alveolar ridge and jaw position was obtained by intraoral scanning technique. After routine design, manufacturing and try-in of metal framework for removable partial denture, the metal framework was located in the mouth and scanned again to obtain the composite model of dentition, alveolar ridge and metal framework. The free-end modified model is obtained by merging the digital model of free-end alveolar ridge with the virtual model with the metal framework. The three-dimensional model of artificial dentition, and base plate was designed on the free-end modified model, and the resin model were made by digital milling technology. The removable partial denture was made by accurately positioning the artificial dentition and base plate, bonding metal framework with injection resin, grinding and polishing the artificial dentition and resin base. Compared with the design data after clinical trial, the results showed that there was an error of 0.4-1.0 mm and an error of 0.03-0.10 mm in the connection between the resin base of artificial dentition and the connecting rod of the in-place bolt and the connection between artificial dentition and resin base. After denturen delivery, only 2 patients needed grinding adjustment in follow-up visit due to tenderness, and the rest patients did not find any discomfort. The digital fabrication process of removable partial denture used in this study can basically solve the problems of digital fabrication of free-end modified model and assembly of artificial dentition with resin base and metal framework.

Characteristics of heart rate variability in patients with vestibular migraine / 中华耳鼻咽喉头颈外科杂志

Objective: To analyze the characteristics of heart rate variability (HRV) in patients with vestibular migraine (VM) and to explore its possible mechanism. Methods: Forty-eight patients with VM [17 males and 31 females, age (36.2±9.2) years], 44 patients with migraine [15 males and 29 females, age (34.4±9.0) years], and 30 patients with health check-ups during the same period [12 males and 18 females, age (34.6±6.5) years old] were selected as study subjects. Ambulatory ECG monitoring was performed in all subjects, and the HRV characteristics of each group were analyzed from both daytime and nighttime time phases. Time domain parameters were analyzed: standard deviation of normal to normal (SDNN), root mean square of successive differences (RMSSD), and percentage of normal to normal intervals differing by more than 50 ms (pNN50). The parameters in the frequency domain were analyzed: high frequency power (HF), low frequency power (LF), and the ratio of low frequency to high frequency power (LF/HF). Statistical analysis of the data was performed using SPSS 26.0 software. Results: At night, RMSSD (F=6.694) and HF (F=9.434) were lower in the VM and migraine groups compared to the control group, while LF/HF (F=16.049) and LF (F=9.434) were elevated compared to the control group, with statistically significant differences (P<0.05 or P<0.01), while LF was significantly elevated in the VM group compared to the migraine group, with a statistically significant (P<0.05). On the daytime measurements, mainly LF was elevated in the vestibular migraine group compared with the control group, while RMSSD was decreased compared with the control group, with statistically significant differences (P<0.05). Conclusion: Autonomic dysfunction characterized by sympathetic hyperfunction and vagal hypofunction is present in VM patients and is more pronounced at night. In addition, the degree of autonomic dysfunction may be more pronounced in VM patients than in migraine patients.

Influence of dental restorative material properties on bond interface reliability: a finite element analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Varieties of restorative materials are widely used in dentistry. The aim of this study is to explore the influence of different dental restorative materials on bond interface reliability.</p><p><b>METHODS</b>A two-dimensional finite element analysis method was adopted to simulate the shear-bond efficacy test. The influence of elastic modulus and Poisson's ratio were investigated separately. Several dental restorative materials including resins, metals, and ceramics were analyzed in this study.</p><p><b>RESULTS</b>The deformation and peak equivalent stress level of the dentin-adhesive interface rose sharply following a decrease in the elasticity of restorative materials, especially those with a low elastic modulus range. The influence of the Poisson's coefficient was not significant. Ceramics and gold alloy were preferred to resin composite in restorations bearing extensive shear load during service.</p><p><b>CONCLUSIONS</b>Restorative materials with an elastic modulus similar to that of teeth are not always the best clinical choice. This research provides a helpful guide for the application of different restorative materials in clinical practice.</p>

Chemical constituents from the roots of Angelica polymorpha Maxim / 药学学报

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.

A new naphthaquinone derivative from Pyrola calliantha H. Andres / 药学学报

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.

Effect of surface treatment on the bonding of silicone elastomer to acrylic resin / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of surface treatments on the bonding of silicone elastomer to acrylic resin.</p><p><b>METHODS</b>Ninety acrylic resin specimens were randomly divided into 9 groups which were assigned to 9 different surface treatments: finished by 80-, 240-, 400-, 600-, 800-, 1000-, 1500-grit silicon carbide paper under running water, or polished or sandblasted. Roughness of the specimen surface was tested in each group, and the microstructure was observed with scanning electron microscopy (SEM). ZY-1 silicone elastomer, ZA-1 primer and acrylic resin specimens were prepared. Shear bond strength were tested and failure modes were assessed for all specimens.</p><p><b>RESULTS</b>The roughness of all 9 groups showed significant difference (P < 0.05). The sandblasted group showed the highest roughness [(2.97 + or - 0.48) microm], the 1500-grit silicon carbide paper finished group showed the lowest roughness [(0.21 + or - 0.14) microm]. The sandblasted groups showed the lowest bonding strength [(0.98 + or - 0.11) MPa] (P < 0.05) while the 600-grit silicon carbide paper finished group showed the highest strength [(2.13 + or - 0.14) MPa].</p><p><b>CONCLUSIONS</b>Over high surface roughness does not improve the shear bond strength between silicone elastomer and acrylic resin. Treatment of acrylic resin surface with 600-grit silicon carbide paper can increase the shear bond strength between silicone elastomer and acrylic resin.</p>

Determination of icaritin in rat plasma by HPLC-MS/MS / 药学学报

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.

Application of multislice helical computed tomography in maxillofacial distraction osteogenesis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To develop the method and investigate the value of the application of multislice helical computed tomography (CT) in the maxillofacial distraction osteogenesis.</p><p><b>METHODS</b>Twelve cases of maxillofacial distraction osteogenesis (3 in zygoma, 2 in maxilla, and 7 in mandible) were scanned by the multislice helical CT, then the reconstruction of three dimensional and fault image and the relative measurement were carried out to study the effect of distraction and osteogenesis.</p><p><b>RESULTS</b>The three dimensional image provided clear and high resolution stereoscopic view that the effect of distraction osteogenesis could be evaluated easily and exactly. The fault image could be set up in private computer by Mimics and the measurements, such as distance, thickness and density, could be performed as expected. The effect of 12 cases was satisfied, and the average distracted distance was 16.73 mm.</p><p><b>CONCLUSION</b>Basing on multislice helical CT scanning, the high resolution image reconstruction and relative measurement data could be obtained which could meet the need of clear and direct observation. Its application in the maxillofacial distraction osteogenesis is expecting and promising.</p>

Effect of Candida albicans growth on silicone elastomer containing nano-TiO2 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the antibacterial effect against Candida albicans of the A-2186 silicone elastomer containing nano-TiO2 in vitro.</p><p><b>METHODS</b>Antibacterial agent of nano-TiO2 was added into A-2186 silicone elastomer with incorporating percentages of 0.5%, 1.0%, 1.5%, and 2.0% (W/W). There was no nano-TiO2 in the control group. The antibacterial effect of the A-2186 silicone elastomer was determined using the film contact method with lighting and without lighting.</p><p><b>RESULTS</b>Either with lighting or without lighting, there were significances between the experiment groups and the control group (P < 0.05). When the incorporating percent was 2.0%, the inhibitory effect was the best among the experiment groups. Without lighting, the inhibitory rate was 53.7% and with lighting, the inhibitory rate was 85.9%.</p><p><b>CONCLUSIONS</b>The A-2186 silicone elastomer containing nano-TiO2 has antibacterial properties against Candida albicans, which enhances with increases of nano-TiO2 percent in the material. With the same incorporating percentage, the antibacterial effect with lighting is better than that without lighting.</p>

Studies on bioassay-guided anti-inflammatory fraction in bark of Albizia julibrissin combined determination with LC-MS-MS / 中国中药杂志

<p><b>OBJECTIVE</b>To search the anti-inflammatory fraction of Albizia julibrissin.</p><p><b>METHOD</b>Inflammatory model of Kunming mice ear edema induced by croton oil and determination combined with the LC-MS-MS-guided fractionation and isolation were used.</p><p><b>RESULT</b>The n-butanol fraction (AJ-B) obtained from the ethanolic extract of the Cortex albiziae was the major active fraction. The lignan glycosides fraction (AJ-B-1), which was further isolated from AJ-B, showed significant anti-inflammatory activity and exhibited dose-dependent relationship in the dose of 5 to 20 mg x kg(-1).</p><p><b>CONCLUSION</b>The method of bioassay-guided fractionation and isolation combined with the LC-MS-MS determination may be of benefit to the logical studies on the bioactive fractions or constituents of traditional Chinese materia medica.</p>

Antidepressant-like effects of the ethanolic extract of Xiaobuxin-Tang, a traditional Chinese herbal prescription in animal models of depression / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Xiaobuxin-Tang, a traditional Chinese herbal prescription recorded in a silk scroll unearthed from Mogao Caves of Dunhuang has been indicated that it can remit depressive disorder. The present study was designed to investigate its antidepressant effects in various animal depression models.</p><p><b>METHODS</b>Xiaobuxin-Tang was extracted by 70% alcohol, and then three behavioral despair models and 5-Hydroxytryptophan (HTP)-induced head twitch response model were adopted to assess the antidepressant effects of the ethanolic extract of Xiaobuxin-Tang with the study on spontaneous motor activity. Groups of mice and rats received oral treatment with Xiaobuxin-Tang (150 - 1200 mg/kg) only once acutely in all tests. The duration of immobility was measured during the last 4 minutes of the 6-minutes test period in mice forced swimming test, rats forced swimming test and mice tail suspension test. In 5-HTP-induced head twitch response, the mice were intraperitoneally administered with 120 mg/kg of L-5-HTP, and then the cumulative number of head twitches was counted in 20 minutes. Spontaneous motor activities of mice were recorded automatically in 10 minutes by VIDEOMEX-V image analytic system.</p><p><b>RESULTS</b>The extract at doses of 300 mg/kg (p.o.) and 600 mg/kg (p.o.) significantly decreased the duration of immobility time in a dose dependent manner in mice forced swimming test; also, the extract at dose of 1200 mg/kg (p.o.) significantly decreased the duration of immobility time in rat forced swimming test. Furthermore, the extract at a dose of 600 mg/kg had the same effect in mice tail suspension test. Meanwhile, the extract at the effective doses for behavioral despair models, had no effect on spontaneous motor activity in mice. The extract (300 - 1200 mg/kg, p.o.) also increased the accumulative number of the 5-HTP-induced head twitch response in mice in 20 minutes.</p><p><b>CONCLUSION</b>Our results suggested that the ethanolic extract of Xiaobuxin-Tang exerts antidepressant-like effect.</p>

Chemical constituents of Ligularia duciformis / 药学学报

Ligularia duciformis is a plant of the Ligularia genus (Compositae) which has been reported to have therapeutic effects of treating diseases such as bronchitis and coughing. In order to find out the bioactive components, the 85% ethanol extract of the root and rhizome of L. duciformis was treated by solvents extraction and column chromatography on silica gel and Sephadex LH-20. Six compounds were obtained from the ethyl acetate fraction and identified as 3-methoxy-4-hydroxyphenylpropyl caffeate (I), 6beta, 8beta-dihydroxyeremophil-7 (11)-en-12, 8alpha-olide (II), 6beta, 8alpha-dihydroxyeremophil-7 (11)-en-12, 8beta-olide (III), 6beta-hydroxyeremophil-7 (11)-en-12, 8alpha-olide (IV), stigmasterol (V) and beta-daucosterol (VI) by analysis of their physic-chemical constants and spectral data. Compound I is a new compound and compounds II - V were isolated from L. duciformis for the first time. The antitussive effect of the compounds is under evaluation.

Segmental reconstruction of maxillary defects by arced distraction osteogenesis of zygoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the possibility of segmental maxillary regeneration by arced distraction osteogenesis of zygoma.</p><p><b>METHODS</b>The distraction of zygoma with the internal arced devices was performed in 2 dogs to simulate the reconstruction of maxillary defect. The zygoma was distracted about 12 mm, and the process of new bone formation was studied by histology and scanning electron microscopy.</p><p><b>RESULTS</b>The transport disk was distracted about 12 mm around the arc. After 8 weeks of consolidation, the density of new bone was close to that of normal bone.</p><p><b>CONCLUSIONS</b>The segmental maxillary regeneration by arced distraction osteogenesis of zygoma is possible.</p>

Study on chemical constituents of bark of Paeonia suffruticosa / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of the bark of Paeonia suffruticosa.</p><p><b>METHOD</b>The 95% ethanol extract was re-extracted with EtOAc, and then separated and purified by column chromatography using silica gel, Sephadex LH -20 and RP-18 as packing materials. The structures were identified on the basis of spectral analysis and physico-chemical characters.</p><p><b>RESULT</b>Six compounds were isolated and identified as (+)-catechin (1), paeonidanin (2), paeoniflorigenone (3), 2, 5-dihydroxy-4-methoxyacetophenone (4), paeonol (5), gallic acid (6).</p><p><b>CONCLUSION</b>The compound 1 was isolsted from the genus Paeonia for the first time. The compounds 2, 3 were isolated from this plant for the first time.</p>

Chemical constituents of Knoxia valerianoides / 药学学报

<p><b>AIM</b>To study the chemical constituents of Knoxia valerianoides Thorel et Pitard.</p><p><b>METHODS</b>Chromatographic methods were used for the isolation and purification. Structures were elucidated on the basis of chemical analysis and spectroscopic data.</p><p><b>RESULTS</b>Three anthraguinones were isolated from K. valerianoides and identified as 1, 3, 5-trihydroxy-2-methyl-6-methoxyl-anthraguinone (kaoxiadin, I), 1, 3, 6-trihydroxy-5-ethoxylmethyl-anthraguinone (II) and 1, 3-dihydroxy-2-methylanthraguinone (rubiadin, III).</p><p><b>CONCLUSION</b>Compound II is a new anthraguinone constituent.</p>

Studies on the chemical constituents in seeds of Atriplex centralasiatica / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents in seeds of Atriplex centralasiatica.</p><p><b>METHOD</b>The chemical components were isolated by solvents extractions and column chromatography. The chemical structures were identified on the basis of physicochemical constants and spectral data.</p><p><b>RESULT</b>Six compounds were isolated and identified as isorhamnetin(I), tricin(II), querecetin-7-O-alpha-L-rhamnoside(III), isoorientin(IV), beta-sitosterol(V), beta-daucosterlo(VI).</p><p><b>CONCLUSION</b>Compound I, II, III, IV are isolated from genus Atriplex for the first time.</p>

Rapid identification of the isomeric impurity in raw drug of cefepime dihydrochloride by liquid chromatography-tandem mass spectrometry / 药学学报

<p><b>AIM</b>To establish a sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of isomeric impurity in raw drug material of cefepime dihydrochloride.</p><p><b>METHODS</b>The HPLC separation experiments were performed on a reversed phase C18 column, with acetonitrile-10 mmol x L(-1) ammonium acetate (5:95) as mobile phase (a flow rate of 0.8 mL x min(-1)). The analytes were determined by electrospray ionization tandem mass spectrometry in positive mode. The chromatogram and mass spectra of cefepime dihydrocloride and its isomeric impurity were obtained by LC-MS/MS.</p><p><b>RESULTS</b>The method can be used for the separation and identification of cefepime dihychrocloride and its isomeric impurity, of which the retention times were 15.28 min and 9.18 min, respectively. Based on the MS/MS spectra of their molecular ions, the different fragmentation pathways of cefepime dihydrocloride and its isomeric impurity were compared and proposed.</p><p><b>CONCLUSION</b>The method was rapid, sensitive and specific. It can be used for the identification of the isomeric purity in raw drug material of cefepime dihydrochloride.</p>

The chemical constituents of Knoxia valerianoides / 药学学报

<p><b>AIM</b>To study chemical constituents of Knoxia valerianoides Thorel et Pitard.</p><p><b>METHODS</b>Chromatographic methods were used for the isolation and purification. Structures was elucidated on the basis of chemical analysis and spectroscopic data.</p><p><b>RESULTS</b>Two anthraquinone were isolated from Knoxia valerianoides Thorel et Pitard and identified as 1,3,5-trihydroxy-2-ethoxymethyl-6-methoxyl-anthraquinone (I) and 1,3-dihydroxy-2-ethoxymethyl-anthraquinone (II).</p><p><b>CONCLUSION</b>The compound I was found to be a novel anthraquinone constituent and II was isolated from Knoxia valerianoides Thorel et Pitard for the first time.</p>

Construction of three-dimensional finite element model of human edentulous maxilla and cranial skeleton / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To develop an effective and feasible method to construct three-dimensional finite element model of the whole edentulous maxilla and cranial skeleton.</p><p><b>METHODS</b>Based on three-dimensional computer aided design model which was constructed by multi-slices helical CT scanning data of a male's head in specialized software, three-dimensional finite element model of edentulous maxillary and cranial skeleton was established; the stresses distribution in maxilla was investigated under occlusal load with computer simulated a complete overdenture.</p><p><b>RESULTS</b>The three-dimensional finite element model of edentulous maxilla and cranial skeleton had favorite similarity in geometry, the distributions of stresses in maxilla and the wall of maxillary sinus could be clearly observed.</p><p><b>CONCLUSIONS</b>The study verifies that this three-dimensional finite element modeling method is feasible and effective.</p>

Studies on the chemical constitutents in herb of Verbena officinalis / 中国中药杂志

<p><b>OBJECTIVE</b>To isolate and identify the chemical constituents from Verbena officinalis.</p><p><b>METHOD</b>The compounds were isolated by means of chromatography and the structures were determined on the basis of physical and spectral analysis.</p><p><b>RESULT</b>Four compounds were isolated and identified as apigenin (I), 4'-hydroxywogonin (II), verbenalin (III) and hastatoside (IV).</p><p><b>CONCLUSION</b>Compounds I and II were obtained from the genus for the first time.</p>