New insight into enhanced photocatalytic selectivity of g-C3N4 by nitrogen vacancy introduction: Experimental study and theoretical calculation.

Constructing photocatalyst with both high efficiency and selectivity is highly desired in water treatment process. However, it is difficult to realize the selectivity of photocatalysis due to the non-selective oxidative species produced in this process. Herein, for the first time, the photocatalytic selectivity was achieved on g-C3N4 (CN) through N vacancy introduction for effective removal of organic pollutants, and the mechanism of vacancy induced selectivity enhancement was studied. The nitrogen vacancy modified CN (VCN) showed enhanced photocatalytic activity and unique selectivity towards phenolic compounds with electron-donating group, whose kinetic constant for p-aminophenol (p-NH2) degradation was 5.95 times higher than that over CN. Moreover, VCN photocatalytic system also displayed similar selectivity in binary pollutant systems. Characteristics and theoretical calculation results confirmed the enhanced photocatalytic performance and selectivity of VCN was mainly attributed to the effect of N vacancy. On one hand, electron-deficient N vacancy enhanced the adsorption of the O2 and phenolic compounds, which promoted the production of O2•- and strengthened the photocatalytic surface reaction. On the other hand, the N vacancy preferred to adsorb the electron-donating groups of phenolic compounds, which resulted in their selective removal.

The application of standardized patients in the clinical practice teaching of occupation therapy / 中华医学教育探索杂志

Objective To explore the applications of standardized patients teaching method in clin-ical practice teaching effect for students majoring in rehabilitation therapy in the course of occupation therapy. Methods The 2013 classes of rehabilitation therapy specialty in our college were selected as the subjects of study in the two groups. Group 1 was taught by the traditional teaching method, while group 2 was taught by the standardized patients (SP) teaching method. After learning, we made an analysis of two groups through the form of theory questions, practical operation and the questionnaire to assess the teaching efficacy. Measurement data using two sample mean t-test after SPSS 13.0 software for statistical analysis. Results The scores of skills test and questionnaire in students taught by SP teaching method is signifi-cantly higher than those in students taught by traditional teaching method (P<0.05). In the theoretical exami-nation, the SP teaching group outperformed the traditional teaching group, but the difference was not statis-tically significant. Conclusion In occupation therapy application, SP teaching is superior to traditional teaching in improving students' ability of analysis and judgment, operation skill and communication level, which can be extended to other clinical courses of rehabilitation therapy.

The application of workshop teaching in practical operation of exercise therapy courses for reha-bilitation major students / 中华医学教育探索杂志

Objective To compare the differences in the practical operation of exercise therapy courses for rehabilitation major students between workshop teaching method and traditional teaching method, and to explore the teaching model and process of workshop teaching method. Methods We im-plemented traditional teaching method in 94 rehabilitation major students in grade 2012 from Xuzhou Medical University, while 96 students in grade 2013 were taught by workshop method, which is based on specific cases, combined with multi-angle evaluation methods and various treatment protocols, with the opti-mal therapeutic method carried out after learning different practical operations and comparing their indica-tions. Then we conducted course satisfaction survey and skills operation evaluation on students from both grades after the course, and the t test was performed with the use of SPSS 19.0. Results The survey showed that the satisfaction score was significantly higher in grade 2013 students with workshop teaching method (79.07±10.49), compared with that in grade 2012 students with traditional teaching method (72.59±13.56), and the difference was statistically significant (P<0.05); as for the skills operation evaluation, the average score was significantly higher in students from 2013 grade (95.04±2.98), compared with that in students from 2012 grade (92.33±1.97), and the difference was statistically significant (P<0.05). Conclusions The work-shop teaching method can significantly improve students' satisfaction for the practical course of exercise therapy while improving their operation abilities.

Wnt signaling promotes the differentiation of adipose mesenchymal stem cells into type II alveolar epithelial cells / 中国组织工程研究

BACKGROUND:Ability of adipose mesenchymal stem cels differentiating into type II alveolar epithelial cels and the regulating mechanism have not been fuly elucidated. OBJECTIVE:To study the ability of adipose mesenchymal stem cels differentiating into type II alveolar epithelial cels in vitro and the function of Wnt pathway in the regulation of differentiation. METHODS:Adipose mesenchymal stem cels were obtained from fat tissue of rats and identified by flow cytometry. The adipose mesenchymal stem cels were divided into control group, smal airway growth medium (SAGM) group and Wnt3a group. Control group was treated with normal DMEM medium; SAGM and Wnt3a groups were both treated with smal airway growth medium, and additionaly, the Wnt3a group was treated with Wnt3a, a Wnt signaling pathway agonist. After 10 days, quantitative RT-PCR and immunofluorescence detection were used to test the expression of surfactant proteins B, C, D, type II alveolar epithelial markers. Phosphorylatedβ-catenin and GSK-3β were detected using western blot after 5 and 10 days of induction. RESULTS AND CONCLUSION: Adipose mesenchymal stem cels with high purity could be successfuly isolated from the adipose tissue of rats, and expressed CD44 and CD29, but not CD11b and CD45. After SAGM treatment, protein and mRNA expressions of surfactant proteins B, C, D were al increased in adipose mesenchymal stem cels (P < 0.01), indicating the ability of adipose mesenchymal stem cels to be induced into type II epithelial cels. Surfactant proteins B, C, D expressions at protein and mRNA levels were significantly higher in the Wnt3a group than the SAGM group (P < 0.01). During the induction progress, the expression of phosphorylated β-catenin gradualy increased, but GSK-3βexpression gradualy decreased in the Wnt3a group (P < 0.01). These findings indicate that Wnt signaling pathways are involved in differentiation of adipose mesenchymal stem cels into type II alveolar epithelial cels.

Influence of enhanced patient education on the patients' knowledge and awareness of peripherally inserted central catheter / 中华临床营养杂志

Objective To explore the usefulness of enhanced patient education in increasing the patients' knowledge and awareness of peripherally inserted central catheter (PICC) protection.Methods Totally 200 patients with PICC in Neijiang First People's Hospital from June 2009 to June 2012 were divided into control group (odd numbers,conventional patient education,n =100) and observation group (even numbers,enhanced patient education,n =100) according to their admission numbers.The patients' knowledge and awareness of PICC protection were analyzed after treatment,and the incidences of adverse events and catheter indwelling time were also compared between these two groups.Results Compared with the control group,the observation group had significantly higher PICC protection knowledge rate (91％ vs.78％,P =0.001),awarehess rate (95％ vs.80％,P=0.011),lower incidence of adverse events (1％ vs.5％,P =0.034),and longer PICC indwelling time [(125.8 ± 10.6) d vs.(106.7 ±8.2) d,P =0.026].Conclusion Enhanced patient education can effectively enhance the patients' knowledge and awareness of PICC protection.

Investigation on the mechanisms for biocompatibility of chitosan using agarose/chitosan blended hydrogels as a model / 国际生物医学工程杂志

ObjectiveTo investigate the possible mechanisms for biocompatibility of chitosan material using agarose/chitosan blended hydrogels as a model.Methods A series of agarose/chitosan blended hydrogels with different chitosan content were prepared by the blending method.The chemical groups of the blended hydrogels were analyzed by the Fourier transform infrared (FTIR) spectroscopy.The blending compatibility between the agarose and chitosan was evaluated with the fluorescein-4-isothiocyanate (FITC) staining method.The charge of the blended hydrogels was determined by the zeta potential measurement.The adsorption of total fetal bovine serum (FBS) proteins and bovine serum albumin (BSA) on the blended hydrogels was measured by the bicinchoninic acid (BCA) method.The adsorption of fibronectin (FN) on the blended hydrogels was measured with ELISA.Cell culture experiment adopted human microvascular endothelial cell line (HMEC-1) as the model.The cytocompatibility was studied by evaluating adhesion,proliferation,and morphology of the cells on the blended hydrogels.Results Characteristic chemical groups of chitosan could be detected in the agarose/chitosan blended hydrogels.The chitosan had a good blending compatibility with the agarose.The amino groups of chitosan were uniformly distributed in the blended hydrogels.The blended hydrogels were strongly positively charged at acidic pH (pH 3.0),however,the zeta potentials of all the hydrogels were reduced to nearly 0 mV at neutral pH (pH 7.4).There were no significant differences in the adsorption of total FBS proteins and BSA between the blended hydrogel groups.However,the adsorption of FN on the hydrogels significantly increased with the increase of chitosan content.Cell culture experiment indicated that the cytocompatibihty of the blended hydrogels was significantly improved with the increase of chitosan content.The HMECs exhibited higher levels of adhesion,spreading,and proliferation on the hydrogels with higher chitosan content.ConclusionResults in this study indicated that the chitosan component preferentially adsorbed FN compared to the other serum proteins,leading to adhesion and spreading of the cells on the blended hydrogels.In contrast to prevailing views,it was found in the present study that the biocompatibility of chitosan did not relate to its positive charge.

Upregulated expression of IGF-2R is induced by hypoxia and serum deprivation in neonatal rat cardiomyocytes in vitro / 基础医学与临床

Objective To investigate the expression of insulin-like growth factor 2 receptor(IGF-2R)induced by hypoxia and serum deprivation(H/SD)in cultured neonatal rat cardiomyocytes in vitro.Methods Cultured neonatal rat cardiomyocytes were randomly divided into control group and H/SD group.Expression of IGF-2R mRNA was measured by RT-PCR and real time RT-PCR.Level of IGF-2R protein was measured by enzyme-linked immunosorbent assay(ELISA).Results Compared with control group,the expression of IGF-2R mRNA increased significantly (P ＜0.01)in cardiomyocytes cultured in H/SD condition for 12 h and 24 h,and IGF-2R protein was upregulated in cardiomyocytes cultured in H/SD condition for 24 h(P ＜0.05).Conclusion H/SD may induce IGF-2R expression,and IGF-2R may potentially explain the mechanism of cardiomyocyte damage induced by ischemia.

Adipose derived mesenchymal stem cell transplantation for Alzheimer's disease / 中国组织工程研究

Alzheimer's disease is an irreversible neurodegenerative disease characterized by progressive neuronal loss. To date, there has been no effective medicine or therapy for neurodegenerative disease. With development of stem cell technique and theory, neural stem cell transplantation has been found to be prospective in Alzheimer's disease treatment. However, it was challenged by the deficiency of autologous neural stem cell, which can bypass immunological barrier. Compared with neural stem cells, mesenchymal stem cells exhibit extensive resources, such as liver, bone marrow and adipose, and multiple differentiations into bone, muscle or adipose. Considering the easy access, the minor trauma to the patients, and the neuron differentiation potential of adipose derived mesenchymal stem cells (A-MSC), we hypothesize that A-MSC graft is a potential and innovative strategy for the treatment of Alzheimer's disease.

Preparation and evaluation of porous poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) hydroxyapatite composite scaffolds.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and PHBHHx-hydroxyapatite (HAP) composite scaffolds have been prepared by phase separation and subsequent sublimation of the solvent for bone tissue engineering. Scanning electron microscopy (SEM), porosity measurement, mechanical tests, and thermogravimertric analysis (TGA) are used to analyze the physical properties of the scaffolds. The biocompatibility and osteoconductivity are assessed by examining the morphology, proliferation, and differentiation of MC3T3-E1 osteoprogenitor cells seeded on the scaffolds. The PHBHHx-HAP composite scaffolds show better mechanical properties, biocompatibility, and osteoconductivity than the PHBHHx scaffolds. The results suggest that PHBHHx-HAP composite scaffolds can be employed as a promising candidate for bone reconstruction.

Thyoid calcifications patterns in sonography and its association with thyroid carcinoma / 中华超声影像学杂志

Objective To evaluate the significance of sonographically detected thyroid calcification in the diagnosis of thyroid carcinoma.Methods Five hundred and twenty-two patients with thyroid disease,including 119 with thyroid cancer,were included in the study.Each patient underwent preoperative,highresolution sonography to evaluate the thyroid gland for the presence of calcification.Calcifications were classified:type Ⅰ,microcalcification;type Ⅱ,coarse calcification;type Ⅲ,annular or"egg-shell"calcification;typeⅣ,calcified nodules within a cyst.Results The incidence of calcification and microcalcification was significantly higher in thyroid cancer than in benign nodules(P＜0.001).The appearance of microcalcifications was highly specific for malignancy with a sonographic specificity of 88%.The sensitivity was 60%,and the odds ratio(0R)was 11.28.The incidence of calcifications of type Ⅱ and type Ⅲ did not differ significantly between the benign and malignant groups.Calcifications of type Ⅳ were showed totally in benign groups.Patients younger than 45 years with calcified nodules constituted a highrisk group,with a OR of 11.33 versus 2.96 in patients older than 45 years with calcified nodules.In the group of solitary thyroid nodules,the incidence of cancer in the calcified nodules was higher than in the nodules without calcifications,with a OR of 20.48.Conclusions The detection of thyroid calcifications by sonography is diagnostically valuable,especially in eases involving a solitary nodule or a young person.The presence of calcifications in these cases should raise the suspicion of malignancy,especially microcalcification.

Mechanisms for biocompatibility of chitosan: A new viewpoint / 中国组织工程研究

OBJECTIVE:In recent years, chitosan has been widely used as tissue engineering scaffolds. In this paper we reviewed the research progress in chitosan biocompatibility and gave a hypothesison possible mechanism of interactions between cells and chitosan. A model system to test this hypothesis was also discussed. DATA SOURCES: Literatures about chitosan biocompatibility were retrieved with computer in Medline, Pubmed and Elsevier from January 1998 to December 2006 with the key words of."chitosan, biocompatibility, surface charge, cell adhesion" in English.STUDY SELECTION: Literatures about chitosan biocompatibility and interactions between chitosan and cells, especially the influence of chitosan charges on cell attachment, were included, whereas repeated experiments were excluded.DATA EXTRACTION: Totally 374 literatures were collected. Among which, 30 were admitted and reviewed.DATA SYNTHESIS: Many mammalian cells can adhere, spread and proliferate on chitosan materials. It is widely accepted that the biocompatibility of chitosan is due to the electrostatic attractive force between positively charged amino groups on chitosan chains and negatively charged cell membranes. However, the pKa value of chitosan amino groups is 6.2-6.8 and the positive charge of chitosan chains is largely decreased under physiological condition as a result of amino groups unprotonation. Thus whether the chitosan's biocompatibility is due to its positive charge remains doubtful and needs further study.CONCLUSION: Based on prior studies, we hypothesize that the positive charge of amino groups on chitosan chains might not be the major factor in biocompatibility of chitosan material. Agarose/chitosan blending hydrogels is supposed to be an appropriate model system to test this hypothesis.

Effects of the degree of deacetylation on the physicochemical properties and Schwann cell affinity of chitosan films.

Chitosan is a potential material for the preparation of nerve repair conduits. In order to find a better chitosan for the application in peripheral nerve regeneration, the effects of the degree of deacetylation (DD) on the physicochemical properties and Schwann cell affinity of chitosan films have been evaluated. Six kinds of chitosan samples with similar molecular weight, but various DD in a range from 70.1 to 95.6% were prepared from one stock chitosan material and fabricated into films. X-ray diffraction analysis showed that there were more crystalline regions in the higher DD chitosan films. Swelling and mechanical property measurements revealed that the swelling index of chitosan films decreased and their elastic modulus and tensile strength increased with the increase in DD. The adsorption amount of fibronectin and laminin on chitosan films was measured by means of enzyme-linked immunosorbent assay (ELISA). Culture of adult rat Schwann cells on the films showed that the chitosan films with higher DD provided better substrata for Schwann cell spreading and proliferation. In conclusion, DD of chitosan plays an important role in their physicochemical properties and affinity with Schwann cells. The results suggest that chitosan with a DD higher than 90% is considered as a promising material for application in peripheral nerve regeneration.

A LIF Mutation at The 29th Amino Acid Totally Abolished The Biological Functions / 生物化学与生物物理进展

Leukemia inhibitory factor (LIF) plays important roles in varieties of biological processes. This factor is highly conserved in mammalian animals and only one heterozygous LIF mutation was reported to cause the infertility of women. A LIF mutation was generated and the evidences were provided that the mutation of mature LIF at the 29th amino acid totally abolished its functions, including stimulation of STAT activation assayed by Luciferase reporter gene expression and EMSA experiments. In addition, the mutated LIF failed to inhibit the proliferation of M1 cells. The data indicated that the mutation of LIF did not have a dominant negative effect but lost the biological functions, suggesting that the 29th amino acid is critical for maintaining the activities of LIF.

Surface modification and characterization of chitosan film blended with poly-L-lysine.

Biodegradable nerve guidance conduits (NGCs) represent a promising alternative to current clinical nerve repair procedures. Chitosan, a natural polysaccharide that has excellent biocompatibility and biodegradability, can be used as a nerve conduit material. The purpose of this work was to study the nerve cell affinity of chitosan modified by blending with different content of poly-L-lysine. PC12 cells culture was used to evaluate the nerve cell affinity of the chitosan-poly-L-lysine composite materials. The results showed that composite materials had significantly improved nerve cell affinity compared to chitosan as indicated by increased attachment, differentiation, and growth of nerve cells. The improved nerve cell affinity might be due to both the increased surface charge and hydrophilicity of composite materials. Composite material with 3 wt% poly-L-lysine content (PL-3) is an even better material in nerve cell affinity than collagen, suggesting that poly-L-lysine-blended chitosan is a promising candidate material for nerve regeneration.

Study on chitosan and PHBHHx used as nerve regeneration conduit material / 生物医学工程学杂志

Both Chitosan and PHBHHx are natural, biodegradable biomedical materials. In this article, their ability to be made as nerve regeneration conduits are evaluated by studying their wettability, changes of the second structure of protein absorbed on their surface, growing status of fetal rat cerebral cortex nerve cells cultured on them, mechanical properties and ability to be processed later. The results indicate that both Chitosan and PHBHHx are promising nerve conduit materials.