[Study of the effect of different methods on the removal of calcium hydroxide in root canal by micro-computed tomography in vivo].

PURPOSE: To establish molar root canal model with micro-computed tomography (Micro-CT) and evaluate the removal efficiency of calcium hydroxide by different methods. METHODS: Eight molar teeth (24 root canals) extracted from the Department of General Dentistry, Shanghai Ninth People's Hospital from October 2023 to February 2024 were collected. Root canal preparation was instrumented by M3 according to standard root canal treatment procedures, then calcium hydroxide was injected into the root canal. One week later, the samples were randomly divided into 3 groups according to different irrigation methods(n=8): lateral opening syringe group, ultrasonic group and sonic vibration group. Micro-CT was used to reconstruct the root canal system before and after irrigation, and independent root canals were marked with different colors. The root canals were divided into upper root segment, middle root segment and apex segment. The volume of calcium hydroxide in each canal was calculated, and the clearance rate of calcium hydroxide was compared among the groups. SPSS 19.0 software package was used for statistical analysis. RESULTS: None of the three methods could completely remove calcium hydroxide from the root canal. When sodium hypochlorite was used as the flushing solution, the removal effect of ultrasonic group and sonic vibration group was significantly better than that of lateral opening syringe group(P＜0.05). The removal efficiency of calcium hydroxide by ultrasonic group and sonic vibration group was similar, and the difference was not statistically significant(P＞0.05). The removal rate of calcium hydroxide in apical segment was low. CONCLUSIONS: Micro-CT can reconstruct the molar root canal model efficiently for evaluating the removal effect of calcium hydroxide. The removal efficiency of calcium hydroxide in ultrasonic group and sonic vibration group is similar, and both are better than that in lateral syringe group.

Comparative Study on Chemical Constituents of Ginseng Flowers with Four Consecutive Cultivation Age.

The harvest period of cultivated ginseng is generally 4-6 years. Ginseng flowers (GFs), the nonmedicinal parts, are usually removed every autumn, in which components are generally believed to stay unchanged with the increasing cultivation age. Recently, few documents were reported on the variation of volatile organic compounds (VOCs) and other components about ginseng flowers. This study had an insight into the variation of the chemical constituents with the cultivation ages through the comparison of the volatile organic compounds, gross ginsenosides, crude polysaccharide, and gross proteins of ginseng flowers from 3-, 4-, 5-, and 6-yr-old (GF3, GF4, GF5, and GF6) which were conducted by headspace solid-phase microextraction-gas chromatography-triple quadrupole mass spectrometry (HS-SPME-GC-QQQ/MS) and spectroscopic analysis combined with multivariate statistical analysis, including one-way ANOVA analysis and T test. The results indicated that the crude polysaccharide contents raised significantly depending on cultivation age except 6-yr-old, whereas the gross ginsenosides and the gross protein content were indistinctive. According to the peak intensity of determined VOCs, the contents of most differential compounds arranged in an order from high to low are GF3, GF4, GF5, and GF6, such as the compounds 2-15, 17-19, 22, and 25-26, therefore, they can be inferred that they are important markers to identify the age of GFs. 461 common differential compounds were gained and 26 common volatile organic compounds were identified with RSI >800 and RI and RIx no more than 30, including alcohols (such as 11, 12, and 15), sesquiterpenes (such as 2, 3, and 4), esters (such as 1 and 26), naphthalene and naphthol (such as 7 and 20), which had potential effects on curing Alzheimer's disease, inflammatory diseases, and prostate cancer based on network pharmacology analysis. This paper firstly revealed the variation rules of constitutions of GFs, which may provide a reference for the harvest and making rational application.

miR-522 facilitates the prosperities of endometrial carcinoma cells by directly binding to monoamine oxidase B.

It is well known that microRNAs (miRNAs) are crucial regulatory factors in tumorigenesis, as tumor suppressors or cancer-promoting factors. However, the study of endometrial carcinoma relevance in miR-522 is rare, indicating an undefined molecular mechanism for its role. Therefore, we performed this study to examine the role of miR-522 on the biological behaviors of endometrial carcinoma. In this work, we found that miR-522 was highly expressed in endometrial carcinoma and negatively regulated monoamine oxidase B (MAOB) expression. They also have the opposite effect on prognosis of endometrial carcinoma patients. More importantly, miR-522 could decreased MAOB expression by binding to MAOB with a putative site, thereby promoting cell proliferation, migration, and invasion through in vitro functional analyses, including MTT assay, wound-healing and transwell invasion experiments. Upregulation of MAOB rescued the impacts of miR-522 mimic on cell behaviors. In conclusion, our observations demonstrated that miR-522 accelerated the progression of endometrial carcinoma by inhibiting MAOB, which might lead to a novel therapeutic therapy for endometrial carcinoma.

[Effect of catalase on marginal microleakage of resin restoration after external bleaching].

PURPOSE: To investigate the effect of catalase on marginal microleakage of resin restoration after external tooth bleaching with 10% carbamide peroxide. METHODS: Forty extracted human premolars, both intact and health, were randomly divided into 4 groups: group 1, direct composite resin filling without bleaching; group 2, composite resin filling immediately after external bleaching; group 3, immersed in artificial saliva for 3 weeks after external bleaching ,then filling with composite resin; group 4 ,cavity treated with catalase after external bleaching and then filled with composite resin. After 2000 thermal cycles, the teeth were immersed in 2% methylene blue for 24 hours, then the microleakage of interface of resin restorations was observed under stereomicroscope. The data were analysed with SPSS17.0 software package. RESULTS: Group 1 displayed the least amount of microleakage, while group 2 showed the greatest amount of microleakage, group 3 behaved similarly as group 2, having great amount of microleakage, with no significant difference (P>0.05); the microleakage of group 4 decreased significantly (P<0.05) compared to group 2. CONCLUSIONS: The microleakage increases significantly after external bleaching with 10% carbamide peroxide, then decreases if cavities are treated with catalase, but delay filling can not improve microleakage effectively.

FeCl3-catalyzed stereoselective construction of spirooxindole tetrahydroquinolines via tandem 1,5-hydride transfer/ring closure.

An efficient FeCl(3)-catalyzed stereoselective intramolecular tandem 1,5-hydride transfer/ring closure reaction was developed. The method allows for the formation of structurally diverse spirooxindole tetrahydroquinolines in high yields (up to 98%) with good to excellent levels of diastereoselectivity (up to 99:1 dr). The catalytic enantioselective variant of this process was also investigated preliminarily with a chiral BINOL-derived phosphoric acid.

[Advance in research on endocardial fiborelastosis].

Endocardial fiborelastosis (EFE) is a common infantile myocardiosis. The pathogenesis of EFE may be associated with viral infection, genetic factors, immune factors and endocardial dysplasia. The fundamental pathological changes of EFE include hyperplasia of endocardium elastic fibers and collagen fibers. Acute EFE is a frequent type. Clinical manifestations of EFE are non-specific and children with EFE mainly present with congestive heart failure. Echocardiography is very helpful to the diagnosis of EFE. It is necessary to differentiate EFE from pneumonia complicated by acute congestive heart failure, viral myocarditis and anomalous origin of the left coronary artery. Treatment is meant to control symptoms of congestive heart failure. Patients who respond well to digitalis and have good medication compliance have a favorable prognosis.

Highly efficient and stereoselective construction of dispiro-[oxazolidine-2-thione]bisoxindoles and dispiro[imidazolidine-2-thione]bisoxindoles.

An efficient and stereoselective reaction between 3-isothiocyanato oxindoles and isatins/isatinimines has been developed to afford structurally diverse dispiro[oxazolidine-2-thione]bisoxindoles and dispiro[imidazolidine-2-thione]bisoxindoles in excellent results under mild conditions. The potential of asymmetric induction by means of a chiral auxiliary was explored. The isomers are separable, and products could be isolated as single diastereomers by column chromatography. Further synthetic transformations of the reaction product were also successfully realized.

Diastereo- and enantioselective conjugate addition of 3-substituted oxindoles to nitroolefins catalyzed by a chiral Ni(OAc)2-diamine complex under mild conditions.

A simple catalyst system assembled from an enantiomerically pure diamine ligand and Ni(OAc)(2) efficiently generates chiral metal enolates derived from 3-substituted oxindoles bearing an N-1 carbonyl group. The enolates smoothly undergo diastereo- and enantioselective conjugate addition to a wide range of nitroolefins under mild reaction conditions, furnishing 3,3-disubstituted oxindole products bearing two vicinal quaternary/tertiary stereocenters in 74-95% yields and 60:40 to 99:1 dr, 71-97% ee.

[Clinical analysis of 68 cases of childhood dilated cardiomyopathy].

OBJECTIVE: To study the ECG features in children with dilated cardiomyopathy (DCM), and related factors for the occurrence of arrhythmia secondary to DCM. METHODS: Data from 68 children with DCM from January 1998 to March 2011 were studied. The children were classified into three groups: severe arrhythmia (n=42), non-severe arrhythmia (n=20) and non-arrhythmia (n=6). Left ventricular end diastolic diameter (LVED), left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were compared. RESULTS: Abnormal ECG results were found in all of the 68 children with DCM. Sinus tachycardia (91%) and ectopic pulsatile (86%) were common. LVED in the severe arrhythmia group (74±6 mm) was greater than that in the non-severe arrhythmia group (65±4 mm; P<0.05) and non-arrhythmia group (61±3 mm; P<0.05). LVED in the non-severe arrhythmia group was also greater than that in the non-arrhythmia group (P<0.05). LVEF and LVFS in the severe arrhythmia group were (30±11)% and (22±4)%, respectively, which were lower than those in the non-severe arrhythmia groupï¼»(37±12)% and (28±5)%, respectivelyï¼½and non-arrhythmia groupï¼»(45±9)% and (34±7)%, respectivelyï¼½(P<0.05). There were also significant differences in the LVEF and LVFS between the non-severe arrhythmia and non-arrhythmia groups (P<0.05). CONCLUSIONS: The common abnormal ECG findings are sinus tachycardia and ectopic pulsatile in children with DCM. Arrhythmia is one of the main clinical manifestations of DCM. The occurrence of arrhythmia is associated with the left ventricular size and heart function.

[Studies and application of flow injection chemiluminescence in analytical chemistry].

At present, flow-injection chemiluminescence is of high sensitivity, fast analysis, low cost, wide linear response range, and simplified operation for trace analysis, and makes a feature of fast development and wide application. As a trace analysis method, it is infiltrated in diverse areas. The principle and characteristics of flow-injection chemiluminescence were expounded, and the chemiluminescence systems were introduced in detail in the present article. The research developments, which were mainly about drug analysis, environment monitoring and life sciences examination, were summarized, at home and abroad. The application situations of the method were briefed from aspects of determination of sample, the reaction medium, chemiluminescence systems, the linearity range, and the detection limit. Finally, the author proposed suggestions in view of this method to address the ongoing problems, and prospected broad application of flowing injection chemiluminescence in drug analysis, immunoassay, mineralogical analysis, environment monitoring, clinical medicine and life sciences.

[Voice fatigue test analysis in secondary school teachers].

OBJECTIVE: To investigate the status of voice fatigue and throat disease in the secondary school teachers in Urumqi. METHODS: This study included 11 689 teachers from 109 secondary schools offered by Teaching and Researching Center of Urumqi as the second-stage random sampling. Among them, 3217 teachers were selected to carry out voice fatigue test and routine examination of throat. For those with abnormal routine inspection results, the stroboscopic laryngoscopy were added. RESULTS: The failure rate difference of 3217 secondary school teachers voice fatigue tests during different periods had statistical significance (F = 202.653, P < 0.05). The failure rate difference of voice fatigue test among different throat diseases groups had statistical significance (F = 9.516, P < 0.05). There was statistical significance in failure rates of the voice fatigue tests between 908 cases of disease group and 2309 cases of normal group among different genders and periods (P < 0.05). Female teachers had higher failure rates than male teachers in voice fatigue tests. High failure rates appeared when high volume required for male and female teachers in voice fatigue tests. There was statistical significance in mean value sound pressure level (MVSPL) and mean value fundamental frequency (MVF0) of the voice fatigue tests between different gender and periods (P < 0.05). Male teachers had higher MVSPL than female teachers, female teachers had higher MVF0 than male teachers. There was statistical significance in failure rates of the voice fatigue tests among teachers from different tribes in different periods (P < 0.05). The Uighur had the highest failure rate, while Han had the lowest. Make further pairwise comparisons, failure rates difference of the Han and the Uighur in the voice fatigue tests during different periods had statistical significance. Comparison among other tribes had no statistical significance (P > 0.05). CONCLUSIONS: Voice fatigue is common in secondary school teachers. Female teachers tend to get voice fatigue more easily, when required high volume, the voice fatigue is more serious. Uighurs teachers have highest degree of voice fatigue.

[Fluorescence research on reaction mechanism of nucleic acid with small organic molecules].

The interaction mechanism of nucleic acid with small organic molecules plays an important role in the recognition of the structure and function of nucleic acids, which can also reveal the biological function of nucleic acids and the mechanism of some drugs. Research on the interaction between nucleic acid and small organic molecules plays an important part in simulating the life process and exploring the essence of life. In the present article, detailed description of the fluorescence spectroscopy research methods used in this field is presented. The fluorescence quenching types of the interaction between nucleic acid and small organic molecules (including dyes and drugs) are discussed. There are many factors influencing the fluorescence quenching type, including the temperature, the rate constant of bimolecular quenching process, the fluorescence lifetime, changes of the absorption spectra and so on. So according to different affecting factors, the fluorescence quenching type can be determined based on corresponding theories. Many different kinds of calculation methods are also summarized, including the calculations of the binding constant, the distance between fluorescence donor and receptor, the interaction force type and the binding mode of nucleic acid with small organic molecules. Furthermore, the formation constant of nucleic acid with small organic molecules is studied with different binding numbers. These conclusions have guiding significance for studying the interaction between nucleic acid and small organic molecules. These results can also provide guidance for the development of new nucleic acid probe, and the design of new drug molecules, of which nucleic acid is the important target.

Spectroscopic studies on the interaction of a water-soluble cationic porphyrin with proteins.

The interaction of a water-soluble cationic porphyrin, meso-tetrakis (4-N,N,N-trimethylanilinium) porphyrin (TMAP), with two proteins, bovine serum albumin (BSA) and human serum albumin (HSA), was studied by UV-vis absorption spectroscopy, fluorescence spectroscopy, fluorescence anisotropy and synchronous fluorescence spectroscopy at neutral aqueous solutions. Free base TMAP bound to proteins as monomers and no aggregation was observed. The binding of TMAP quenched the fluorescence of the protein. On the contrary, the fluorescence of TMAP was enhanced and the fluorescence anisotropy increased due to the binding. The direct static binding mechanism could account for the quenching by TMAP and the binding constants were calculated. TMAP showed a higher quenching efficiency and binding constant of HSA than BSA. The binding of TMAP had no obvious effect on the molecular conformation of the protein. There was only one binding site for TMAP and it was located on the surface of the protein molecule. Electrostatic force played an important role in the binding due to the opposite charges on porphyrin and the proteins.

[Clinical observation on acupuncture combined with medicine for treatment of infantile febrile convulsion].

OBJECTIVE: To explore an effective therapy for treatment of infantile febrile convulsion. METHODS: Seventy infants of febrile convulsion were randomly divided into two groups, a combined acupuncture and drug group (n = 36) were treated with Xingnao Kaiqiao needling method with Shuigou (GV 26) selected as main combined with intramuscular injection of luminal and intravenous perfusion of diazepam; and a drug group (n = 34) treated with simple intramuscular injection of luminal and intravenous perfusion of diazepam. Their therapeutic effects, the time of inducing the stopping convulsion, and the recurrence rate were investigated. RESULTS: The total effective rate was 86.1% in the combined acupuncture and drug group, better than 79.4% in the drug group (P<0.05), and the time of inducing the stopping convulsion in the combined acupuncture and drug group was shorter than that in the drug group (P<0.01), and the recurrence rate in the combined group was lower than that in the drug group (P<0.05). CONCLUSION: Acupuncture combined with intramuscular injection of luminal and intravenous perfusion of diazepam is an effective and safe method for febrile convulsion.