[Strategies for demineralized dentin matrix protection and its research progress in dentin-resin bonding restoration].

Both pathological injuries and clinical iatrogenic operations can lead to dentin demineralization, forming demineralized dentin matrix (DDM). Dentin demineralization activates endogenous matrix metalloproteinase (MMP) and cysteine cathepsin (CC), and the mechanical properties of DDM decrease, so DDM is prone to lose its structural integrity under the action of enzymatic degradation and mechanical destruction, which in turn results in the reduction of clinical functional value of DDM in dentin-resin bonding restoration. The administrations of dentin collagen cross-linking reagents and MMP/CC inhibitors are effective strategies to protect DDM structural integrity and achieve its clinical functional value. A variety of chemically synthesized reagents and plant-derived extracts are capable of significantly improving the mechanical properties of DDM and enhancing its enzymatic tolerance. However, the cytotoxicity caused by chemically synthesized reagents and the tooth staining aroused by plant extracts have considerably affected their clinical applicability. Protecting dentin collagen while exerting antibacterial properties is a new direction for future DDM protective agent research. Accordingly, from the perspectives of cross-linking reagents, enzyme inhibitors and compounds which possess the dual proper ties, this review discusses the latest research progress in DDM protection, and looks into its application prospects in dentin-resin bonding, in an attempt to provide reference for the clinical promotion of DDM protection strategy.

[Clinical study of psychological changes and post traumatic stress disorder in elderly patients with hip fracture].

Objective: To explore the psychological state and affected factors of elderly patients with hip fractures. Methods: A retrospective analysis of 156 elderly hip fracture patients(>65 years) admitted to the Department of Orthopaedics, the First Affiliated Hospital of Harbin Medical University from January 2016 to August 2019 was performed. General and psychological information were collected by questionnaire.General information included age, gender, education, whether surgery, length of stay.SCL-90, a self-assessment scale, was chosen as the psychological test to analyzed the elderly hip fracture patients' psychological status during hospitalization and the norms of SCL-90 in Chinese which were established in 1986 were used as the control group. The prognostic factors were examined by univariate and multivariate analysis. Results: Somatization, interpersonal sensitivity, depression, anxiety, paranoid factor scores, and total scores of the elderly hip fracture patients were significantly higher than control group(all P=0.00).Univariate analysis and logistic regression analysis showed that non-surgery treatment and more than 10 days of hospitalization were independent prognostic factors that affected the psychological state of elderly hip fracture patients (all P=0.00). Conclusion: Elderly patients hospitalized with osteoporosis and hip fractures are prone to have negative emotional and psychological changes.The length of hospitalization and the choice of treatment can affect patients' psychological state, suggesting that effective psychological intervention is necessary.

Effect of transvaginal ultrasound on human chorionic villus cell apoptosis during pregnancy.

With the advancement of ultrasonic technology in recent years, sonography has become a common medical diagnostic tool, as it has elevated output sonic intensity and elongated exposure time. This study investigates the effect of ultrasound on human chorionic villus cell apoptosis during early pregnancy. Transvaginal ultrasound was performed for a total of 60 women who had undergone induced abortion at our hospital. They were randomly divided into the control, short ultrasound (10 min), and long ultrasound (20 min) groups (N = 20 each). Twenty-four hours after ultrasonic exposure, chorionic villus tissues were extracted during induced abortion, and were tested for cell apoptosis using flow cytometry. Bax and B cell lymphoma-2 (Bcl-2) protein levels were also quantified by immunohistochemistry. We found that the long ultrasound group had significantly higher cell apoptosis rates compared to the short ultrasound group, which in turn had higher rates compared to the control group (P < 0.05 in both cases). Bax protein levels were elevated in both the long and short ultrasound groups (P < 0.05). Bcl-2 proteins in two ultrasound groups, however, were downregulated as compared to those in the control group (P < 0.05). It is therefore possible that transvaginal sonography can potentiate the apoptosis of human chorionic villus cells by increasing the Bax/Bcl-2 protein ratio.

Stabilization of heavy metals in sludge ceramsite.

This paper attempts to investigate the stabilization behaviours of heavy metals in ceramsite made from wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS). Leaching tests were conducted to find out the effects of sintering temperature, (Fe(2)O(3) + CaO + MgO)/(SiO(2) + Al(2)O(3)) (defined as F/SA ratios), pH, and oxidative condition. Results show that sintering exhibits good binding capacity for Cd, Cr, Cu, and Pb in ceramsite and leaching contents of heavy metals will not change above 1000 degrees C. The main crystalline phases in ceramsite sintered at 1000 degrees C are kyanite, quartz, Na-Ca feldspars, sillimanite, and enstatite. The main compounds of heavy metals are crocoite, chrome oxide, cadmium silicate, and copper oxide. Leaching contents of Cd, Cu, and Pb increase as the F/SA ratios increase. Heavy metals in ceramsite with variation of F/SA ratios are also in same steady forms, which prove that stronger chemical bonds are formed between these heavy metals and the components. Leaching contents of heavy metals decrease as pH increases and increase as H(2)O(2) concentration increases. The results indicate that when subjected to rigorous leaching conditions, the crystalline structures still exhibit good chemical binding capacity for heavy metals. In conclusion, it is environmentally safe to use ceramsite in civil and construction fields.

Ceramsite obtained from water and wastewater sludge and its characteristics affected by (Fe(2)O(3)+CaO+MgO)/(SiO(2)+Al(2)O(3)).

To control and optimize the process for making ceramsite from wastewater treatment sludge (WWTS) and drinking-water treatment one (DWTS), the effect of mass ratios of (Fe(2)O(3)+CaO+MgO)/(SiO(2)+Al(2)O(3)) (defined as F/SA ratios); SiO(2):Al(2)O(3) and Fe(2)O(3):CaO:MgO (under the condition of fixed F/SA ratio) on the characteristics of ceramsite were investigated. It was found that the optimal F/SA ratios for making ceramsite range 0.175-0.45. Na-Ca feldspars and amorphous phases increase in ceramsite as F/SA ratios increase. Ceramsite with porous surfaces, expanded structures, and complex crystalline phases can be obtained at 0.27527.2:15.8 and Fe(2)O(3):CaO:MgO>6:3.5:1.8. Results indicate that F/SA ratios could be used as an important parameter to control the production process of ceramsite with desired physicochemical properties and resolve the disposal problems of residual sludges.

Ceramsite obtained from water and wastewater sludge and its characteristics affected by Fe2O3, CaO, and MgO.

To solve the disposal problems of residual sludges, wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS) were tested as components for producing ceramsite. Fe(2)O(3), CaO, and MgO were the major basic oxides in WWTS and DWTS, so their effect on characteristics of ceramsite was also investigated to optimize the process. Results show that WWTS and DWTS can be utilized for producing ceramsite with optimal contents of Fe(2)O(3), CaO, and MgO ranging 5-8%, 2.75-7%, and 1.6-4%, respectively. Ceramsite within the optimal Fe(2)O(3), CaO, and MgO contents ranges was characterized using thermal analysis, X-ray diffraction (XRD), morphological structures analyses, and compressive strength measurements. Higher strength ceramsite with more complex crystalline phases and fewer pores can be obtained at 6%

Effect of amended soil and hydraulic load on enhanced biological nitrogen removal in lab-scale SWIS.

To characterize the effect of amended soil on nitrogen removal in subsurface wastewater infiltration system (SWIS), culture, grass carbon, and zeolite were mixed to produce microbial inoculums, and then the optimal microbial inoculums, nutrient substance, cinder, and original soil were mixed to produce the soils through bioaugmentation. Results indicate that the microbial inoculums (culture+50% grass carbon+50% zeolite) and the amended soil (12.5% microbial inoculums+25% nutrient substrate+12.5% cinder+50% original soil) have the optimal biogenic stimulating properties, and the adsorption capacity of the amended soil are 1.216 mg-Pg(-1) and 0.495 mg-Ng(-1). The laboratory soil column experiment indicates that the efficient mode of nitrogen removal in lab-scale SWIS is adsorption-nitrification-denitrification and the nitrification/denitrification can be enhanced by the application of the amended soil. On average, the SWIS filled with amended soil converts 85% of ammonia nitrogen (NH(4)(+)-N) to NO(x)(-)-N and removes 49.8-60.6% of total nitrogen (TN), while the system filled with original soil removes 80% of NH(4)(+)-N and 31.3-43.2% of TN at 4-8 cm day(-1). Two systems are overloads at 10 cm day(-1). It is concluded that the microbial activities and nitrogen removal efficiencies are improved in SWIS after bioaugmentation.

Solidification and leaching behaviours of Cr6+ in sludge ceramsite.

Making lightweight ceramsite with sewage sludge is a new effective approach for disposal of sludge. However, there is a concern as to whether the heavy metals such as Cr6+ in sewage sludge can be solidified in ceramsite after sintering. The configuration of Cr6+ in ceramsite was analyzed by X-ray diffraction (XRD) and leaching tests were conducted to determine the effects of sintering temperature, pH and H2O2 concentration on the stabilization of Cr6+ in ceramsite. The results show that leaching of Cr6+ changes little at temperatures above 900 degrees C, and both pH and H2O2 concentration have some effects on the leaching of Cr6+. Leaching test results indicate that Cr6+ is stabilized in ceramsite and cannot be easily released to the environment again as secondary pollution, which eliminates the concern for its application. XRD analysis of ceramsite sintered at 1000 degrees C reveals that the main compounds of Cr6+ in ceramsite are Cr2O3 and FeCrO4. The test results provides a better understanding of the factors that affect the mobility of Cr6+, and show it is a safe way to make ceramsite with sludge as an additive.

Stabilization of heavy metals in ceramsite made with sewage sludge.

In order to investigate stabilization of heavy metals in ceramsite made with sewage sludge as an additive, the configuration of heavy metals in ceramsite was analysed by XRD and while leaching tests were conducted to find out the effect of sintering temperature (850 degrees C, 900 degrees C, 950 degrees C, 1000 degrees C, 1100 degrees C, and 1200 degrees C), pH (1, 3, 5, 7, 9, and 12), and H2O2 concentration (0.5molL(-1), 1molL(-1), 1.5molL(-1), 3molL(-1), and 5molL(-1)) on stabilization of heavy metals (Cd, Cr, Cu, and Pb) in ceramsite. The results indicate that leaching contents of heavy metals do not change above 1000 degrees C and sintering temperature has a significant effect on stabilization of heavy metals in ceramsite; leaching contents of heavy metals decrease as pH increases and increase as H2O2 concentration increases. XRD analysis reveals that the heavy metals exist in steady forms, mainly Pb2O(CrO(4)), CdSiO3, and CuO at 1100 degrees C. It is therefore concluded that heavy metals are properly stabilized in ceramsite and cannot be easily released into the environment again to cause secondary pollution.

Effect of sintering temperature on the characteristics of sludge ceramsite.

In order to investigate the effect of sintering temperature on the characteristics of sludge ceramsite and find an optimal sintering temperature, dried sewage sludge, clay, and water glass were mixed at ratios of dried sewage sludge/clay=33% and water glass/clay=15%. Then these mixtures were heated to 850, 900, 950, 1000, 1100, and 1200 degrees C for production of sludge ceramsite. The sludge ceramsite were characterized by DTA-TGA, SEM-EDS, XRD, and XRF. The results indicate that the differences in thermal behaviours are caused by the compositional and structural variations; the ceramsite sintered at 1000 degrees C has more uniformly distributed finer pores (0.5 microm

Utilization of dried sludge for making ceramsite.

Dried sludge as additive for making ceramsite is a new effective approach for disposal of sludge. In this study sewage sludge, water glass and clay were chosen as the components, the optimal ratio of the components and the most appropriate conditions were obtained. The functions of primary components in the sintering process, porosity formation mechanism and solid phase reaction also have been discussed. The optimized process parameters were shown as follows: the ratio of dried sludge/clay (wt%) was 33%, ratio of adherent /clay (wt%) was 15%, sintering temperature was 1000 degrees C, sintering time was 10 min. Bulk density was 582 kg m(-3), particle density was 1,033 kg m(-3), water absorption was 9.5%, porosity was 43.7%. SEM, EDS, XRD and XRF analyses were also carried out. The results indicate that dried sludge as raw material is a good way for making ceramsite. Biological Aerated Filters (BAFs) with filter media of Guangzhou ceramsite, Jiangxi ceramsite, activated carbon and ceramsite (obtained in test) were selected to treat municipal wastewater. The average removal efficiencies of ceramsite (obtained in test) for turbidity, COD, SCOD and NH3-N were about 96.4%, 76.2%, 59.6% and 82.3% respectively and were higher than those of other ceramsites.